US20080117025A1 - RFID System and Method for Wirelessly Interfacing With an Interrogator - Google Patents
RFID System and Method for Wirelessly Interfacing With an Interrogator Download PDFInfo
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- US20080117025A1 US20080117025A1 US12/016,900 US1690008A US2008117025A1 US 20080117025 A1 US20080117025 A1 US 20080117025A1 US 1690008 A US1690008 A US 1690008A US 2008117025 A1 US2008117025 A1 US 2008117025A1
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- interrogator
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04W—WIRELESS COMMUNICATION NETWORKS
- H04W28/00—Network traffic management; Network resource management
- H04W28/16—Central resource management; Negotiation of resources or communication parameters, e.g. negotiating bandwidth or QoS [Quality of Service]
- H04W28/18—Negotiating wireless communication parameters
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- G—PHYSICS
- G06—COMPUTING; CALCULATING OR COUNTING
- G06K—GRAPHICAL DATA READING; PRESENTATION OF DATA; RECORD CARRIERS; HANDLING RECORD CARRIERS
- G06K7/00—Methods or arrangements for sensing record carriers, e.g. for reading patterns
- G06K7/0008—General problems related to the reading of electronic memory record carriers, independent of its reading method, e.g. power transfer
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- G—PHYSICS
- G06—COMPUTING; CALCULATING OR COUNTING
- G06K—GRAPHICAL DATA READING; PRESENTATION OF DATA; RECORD CARRIERS; HANDLING RECORD CARRIERS
- G06K7/00—Methods or arrangements for sensing record carriers, e.g. for reading patterns
- G06K7/10—Methods or arrangements for sensing record carriers, e.g. for reading patterns by electromagnetic radiation, e.g. optical sensing; by corpuscular radiation
- G06K7/10009—Methods or arrangements for sensing record carriers, e.g. for reading patterns by electromagnetic radiation, e.g. optical sensing; by corpuscular radiation sensing by radiation using wavelengths larger than 0.1 mm, e.g. radio-waves or microwaves
- G06K7/10019—Methods or arrangements for sensing record carriers, e.g. for reading patterns by electromagnetic radiation, e.g. optical sensing; by corpuscular radiation sensing by radiation using wavelengths larger than 0.1 mm, e.g. radio-waves or microwaves resolving collision on the communication channels between simultaneously or concurrently interrogated record carriers.
- G06K7/10079—Methods or arrangements for sensing record carriers, e.g. for reading patterns by electromagnetic radiation, e.g. optical sensing; by corpuscular radiation sensing by radiation using wavelengths larger than 0.1 mm, e.g. radio-waves or microwaves resolving collision on the communication channels between simultaneously or concurrently interrogated record carriers. the collision being resolved in the spatial domain, e.g. temporary shields for blindfolding the interrogator in specific directions
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- G—PHYSICS
- G08—SIGNALLING
- G08B—SIGNALLING OR CALLING SYSTEMS; ORDER TELEGRAPHS; ALARM SYSTEMS
- G08B21/00—Alarms responsive to a single specified undesired or abnormal condition and not otherwise provided for
- G08B21/02—Alarms for ensuring the safety of persons
- G08B21/0202—Child monitoring systems using a transmitter-receiver system carried by the parent and the child
- G08B21/023—Power management, e.g. system sleep and wake up provisions
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- G—PHYSICS
- G08—SIGNALLING
- G08B—SIGNALLING OR CALLING SYSTEMS; ORDER TELEGRAPHS; ALARM SYSTEMS
- G08B21/00—Alarms responsive to a single specified undesired or abnormal condition and not otherwise provided for
- G08B21/02—Alarms for ensuring the safety of persons
- G08B21/0202—Child monitoring systems using a transmitter-receiver system carried by the parent and the child
- G08B21/0241—Data exchange details, e.g. data protocol
- G08B21/0258—System arrangements wherein both parent and child units can emit and receive
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- G—PHYSICS
- G08—SIGNALLING
- G08B—SIGNALLING OR CALLING SYSTEMS; ORDER TELEGRAPHS; ALARM SYSTEMS
- G08B21/00—Alarms responsive to a single specified undesired or abnormal condition and not otherwise provided for
- G08B21/02—Alarms for ensuring the safety of persons
- G08B21/0202—Child monitoring systems using a transmitter-receiver system carried by the parent and the child
- G08B21/0266—System arrangements wherein the object is to detect the exact distance between parent and child or surveyor and item
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
- G01S13/00—Systems using the reflection or reradiation of radio waves, e.g. radar systems; Analogous systems using reflection or reradiation of waves whose nature or wavelength is irrelevant or unspecified
- G01S13/74—Systems using reradiation of radio waves, e.g. secondary radar systems; Analogous systems
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04W—WIRELESS COMMUNICATION NETWORKS
- H04W84/00—Network topologies
- H04W84/18—Self-organising networks, e.g. ad-hoc networks or sensor networks
Definitions
- the invention relates generally to RF identification tags and interrogators, that is, to systems for identifying objects by communication between a radio frequency transceiver mounted on each object (RF identification “tag”) and a radio frequency transceiver “interrogator”. More specifically, the invention relates to such a system in which one or more human operators each has his own interrogator, and in which the 2-way communication range between each operator's interrogator transceiver and the tags is adjusted so as to prevent communications between the interrogator and more distant tags.
- Radio frequency identification (RFID) systems have been proposed for identifying tagged objects for such purposes as taking inventory or tracking movements of objects being transported. Examples are described in commonly assigned U.S. Pat. Nos. 5,300,875; 5,365,551; and 5,448,110.
- RFID systems generally employ a passive or active RF transceiver, called a “tag”, mounted on each object to be identified or tracked.
- An interrogator transceiver periodically transmits RF interrogation signals.
- a tag Upon receiving an interrogation signal, a tag responds by transmitting a response signal containing data which identifies the object and contains any other information which may have been stored or programmed in the tag.
- Conventional RFID systems provide little or no interactive feedback in response to actions performed by handling personnel. Specifically, conventional RFID systems lack any means for discriminating in favor of an individual tagged object a human operator is working with at any given moment; instead, conventional RFID systems generally would confuse the operator by providing information regarding all the tagged objects in the vicinity. Furthermore, if a number of personnel are working close to each other, conventional RFID systems cannot direct information about a tag to the specific individual who is handling the tagged object.
- the present invention is a method of adjusting the 2-way communication range of an RFID system to assist a human operator to individually handle and interrogate a plurality of tagged objects, such as suitcases, which each include an RFID tag transceiver.
- An RFID interrogator transceiver preferably mounted on the operator, periodically broadcasts interrogation messages. Any tag transceiver which is within 2-way communication range of the interrogator receives the broadcasted message and responds by transmitting an identifying message containing data identifying the tagged object.
- the interrogator transceiver receives the response message from the tag and presents to the operator the identifying data contained in the response message, typically via an aural transducer or visual display.
- the 2-way communication range between the interrogator transceiver and the tag transceivers is adjusted to only slightly exceed the closest distance between the interrogator and the tag while the operator is handling the tagged object. Consequently, other tagged objects will remain outside the communication range and will not respond to interrogation messages. Therefore, the operator can be confident that the identifying information he receives from the interrogator pertains to the individual tagged object which the operator currently is handling, rather than pertaining to other tagged objects nearby.
- the interrogator transceiver can be mounted anywhere on the operator's person so as to leave both of the operator's hands free for handling the tagged objects.
- the interrogator can be mounted on the person's belt.
- the interrogator can have an antenna mounted separately, preferably on the operator's wrist band or similarly near the person's hand, so that the operator can extend his hand toward a tagged object to bring the antenna within close communication range of the RFID tag on the object. This allows reducing the communication range so as to minimize the possibility of responses from RFID tags other than the one associated with the individual tagged object which the operator currently is handling.
- a second embodiment of the invention does not necessarily limit the interrogator to communicating with a single tag as in the first embodiment. Instead, an objective of the second embodiment is to prevent one operator's interrogator from communicating with tagged objects being handled by other operators working nearby in the same facility.
- the 2-way communication range between one operator's interrogator and the tags is adjusted so that all tagged objects being handled by other operator personnel are outside the range. Unlike the first embodiment, the 2-way communication range between the interrogator and the tags need not be so short that only one tagged object at a time can be within the range.
- FIG. 1 is a schematic depiction of an airport baggage sorting facility employing the present invention.
- FIG. 2 is a block diagram of an REID tag transceiver used in the present invention.
- FIG. 3 is a block diagram of an RFID interrogator transceiver used in the present invention.
- FIG. 4 is a schematic depiction of the reliable, unreliable, and zero two-way communications zones surrounding an interrogator transceiver.
- the invention will be described in the context of an exemplary implementation, depicted in FIG. 1 , in which the human operators 10 are baggage handler personnel working in an airport baggage sorting facility, and the tagged objects 12 are airline baggage.
- the invention is equally applicable to any other objects to which RFID tags may be attached.
- a number of baggage handler personnel 10 are responsible for loading a large number of suitcases 12 and other baggage pieces into various freight containers 14 , where each freight container has been designated to be loaded on a specific aircraft flight.
- An operator's job is to read the designated flight number and/or destination from a tag 16 attached to each suitcase and then to load the suitcase in the correct freight container.
- Personnel at the airport passenger check-in counter attach an RFID tag 16 to each suitcase 12 .
- the RFID tag is mounted near a handle 18 of the suitcase so that an operator's hand will be as close as possible to the tag when the operator grasps the handle to pick up the suitcase.
- the tag may be attached to the handle by a strap 19 , as shown in FIG. 4 .
- a semiconductor memory 38 within the tag is programmed to store information on the itinerary of the suitcase, such as flight number, time, and destination.
- the tag's memory may be programmed with additional information such as the name of the owner and special handling instructions.
- the tag's memory can be programmed by any conventional means for storing data in a memory device connected to an RF transceiver.
- the RF communications protocol used by the tag transceiver can include commands for storing data, so that such commands could be transmitted to the tag's transceiver by a transmitter used by airport check-in personnel.
- the tag may include physical connectors for connecting the tag to a conventional memory programming apparatus used by airport check-in personnel.
- the sorting facility includes a plurality of freight containers 14 , each container being labelled with the flight number of an aircraft whose baggage is to be loaded into that container by the baggage handler personnel (i.e., the operators). After the operators load the appropriate baggage into a container, the container is wheeled from the baggage sorting facility to the aircraft, where other baggage handler personnel transfer the baggage from the container to the aircraft. The process is performed in reverse when the aircraft reaches its destination.
- Each baggage handling operator 10 in the sorting facility carries a battery-powered RFID interrogator transceiver 20 , the interrogator preferably being attached to the operator's body or clothing so as to leave the operator's hands free and not obstruct the operator's movements.
- the interrogator may be attached to a belt 22 worn around the operator's waist. (Alternatively, the interrogator may be attached to a strap or belt worn around the operator's leg, arm, or wrist.)
- the tag 16 on the suitcase receives an interrogation signal transmitted periodically from the operator's interrogator 20 .
- the tag 16 responds by transmitting a message containing the itinerary information stored in the tag's memory.
- the interrogator 20 receives the message and conveys the itinerary information to the operator, preferably either visually or aurally. The operator uses the itinerary information to decide which freight container 14 the suitcase should be loaded into.
- each of the personnel who unload baggage from the airplane preferably also carries an RFID interrogator 20 attached as described above.
- Each interrogator carried by the unloading personnel would include memory in which a code representing the city (or airport) in which the interrogator is actually located.
- the interrogator periodically broadcasts interrogation messages and receives a response from each tagged object picked up by the person carrying the interrogator.
- the control logic 56 in the interrogator is programmed to compare the intended destination city transmitted by each tag with the interrogator's actual location city stored in memory 58 . If the intended and actual destinations do not match, the interrogator presents a warning signal to the unloading person to alert him that the piece of baggage he currently is unloading does not belong in that city.
- an alternative to each unloading person carrying an interrogator is to mount a single RFID interrogator 20 at each aircraft door through which baggage is unloaded.
- the interrogator should announce a warning if a piece of baggage exiting the door has an intended destination different from the actual destination stored in the interrogator.
- the interrogator can be battery-powered for portability, and can be mounted near the aircraft cargo door by any means. Since the interrogator only needs to be mounted during the short time baggage is being unloaded, the mounting means can be temporary.
- a presently preferred mounting means is a suction cup affixed to the interrogator, allowing it to be temporarily attached to the aircraft skin or door panel.
- an interrogator transceiver adjacent to a cargo door also is useful when first loading baggage on an aircraft to verify that no baggage is loaded which was intended for a different flight.
- the airplane flight number or similar identification should be stored in the interrogator's memory 58 .
- the control logic 56 in the interrogator should be programmed to compare the intended flight number transmitted by each tag to the flight number stored in the interrogator memory, and then signal human personnel in the event of a discrepancy.
- the central computer should include an RF receiver for receiving the data and a memory for storing it.
- the data stored in the central computer is useful for tracking the progress of baggage in case of an inquiry or a lost object.
- the RFID tag transceivers 16 and RFID interrogator transceiver 20 used in the present invention can be any conventional RFID (radio frequency identification) transceivers, examples of which are described in U.S. Pat. Nos. 4,075,632 to Baldwin et al.; 4,857,893 to Carroll; 4,862,160 to Ekchian et al.; 5,055,659 to Hendrick et al; 5,144,314 to Malmberg et al.; and 5,245,346 to Nishimura et al. The entire contents of each of these patents is hereby incorporated into this patent application.
- FIG. 2 shows an RFID tag transceiver 16 suitable for use with the present invention.
- An antenna 30 connects to the output of a transmitter 32 and to the input of a receiver 34 .
- a control logic circuit 36 such as a programmable microcomputer, receives data which has been received and demodulated by the receiver 34 , provides data to the transmitter 32 with which the transmitter is to modulate the transmitted RF signal, and provides control signals to both the receiver and the transmitter.
- the control logic circuit 36 also exchanges data with a memory 38 . All the components just described are conventionally included in an RFID tag transceiver.
- the tag transceiver optionally includes an RF signal amplitude detector 40 . Such amplitude detectors are well known, but are not conventionally included in RFID transceivers.
- FIG. 3 shows an RFID interrogator transceiver 20 suitable for use with the present invention.
- the interrogator has the same components as the tag, namely, an antenna 50 , transmitter 52 , receiver 54 , control logic circuit 56 , memory 58 , and optional RF signal amplitude detector 60 .
- the operator 10 When the operator 10 receives itinerary information for a suitcase 12 , it is important for the operator to know which suitcase the information pertains to. In the present invention, this is accomplished by limiting the transmitter power and/or the receiver sensitivity of the operator's interrogator, of the tags, or of both so that 2-way communication between the interrogator and the tags is possible only over a very short range. Specifically, the maximum range or distance across which the interrogator 20 and tags 16 can reliably communicate should be adjusted so that it is only slightly greater than the distance between the antenna of the operator's interrogator and the tag attached to the single suitcase the operator is handling. All other suitcases 12 ′ in the baggage handling facility should be outside this range.
- the distance between the antenna 50 of the operator's interrogator and the tag 16 on a suitcase will be minimum when the operator 10 grasps the suitcase 12 to move it to the container 14 for the appropriate aircraft.
- the reliable 2-way communication range 70 between an operator's interrogator and the nearby tags should be adjusted to only slightly exceed this minimum distance. Specifically, the reliable 2-way communication range should be adjusted so that (i) a suitcase being grasped or otherwise handled by the baggage handling operator is within the “reliable 2-way communication inner zone” surrounding the interrogator's antenna, and (ii) all other nearby suitcases 12 ′ are outside this inner zone, and preferably are outside the boundary of the “zero 2-way communication” outer zone.
- An interrogator and tag are considered to be within reliable 2-way communication range of each other only if the tag can reliably receive RF signals from the interrogator and the interrogator can reliably receive RF signals from the tag. If RF signals can be reliably received by the interrogator from the tag, but not by the tag from the interrogator—or vice versa—then only one-way reliable communication is possible, and the interrogator and tag are not considered within reliable 2-way communication range.
- the reliable 2-way communication range is the lesser of (a) the maximum distance over which the interrogator can reliably receive RF signals from the tag, and (b) the maximum distance over which the tag can reliably receive RF signals from the interrogator.
- the reliable 2-way communication range can be reduced by reducing the reliable one-way communication range in either direction, that is, by reducing either the tag-to-interrogator one-way range “a” or the interrogator-to-tag one-way range “b” defined in the preceding paragraph.
- the one-way communication range from the tags to the operator's interrogator can be reduced either by reducing the transmitter power of all the tags which otherwise could be within communication range of the interrogator or by reducing the receiver sensitivity of the interrogator.
- the one-way communication range from the operator's interrogator to the tags can be reduced either by reducing the transmitter power of the interrogator or by reducing the receiver sensitivity of all the tags which otherwise could be within communication range of the interrogator.
- the receiver section can include a conventional circuit 40 , 60 for detecting the amplitude of the received signal (i.e., the signal strength), and a comparator which rejects any received signal whose strength is below a certain threshold.
- the threshold can be adjusted to adjust the communications range.
- the comparator and threshold are implemented by suitable programming of the control logic circuit 36 , 56 .
- the adjustments to the transmitter power and/or receiver sensitivity of the tags and interrogators can be made at the time of their manufacture.
- the adjustments to an interrogator also can be performed when the interrogator is placed in service in a given facility, thereby permitting customization of the communication range based on the actual distances between the interrogator and the tagged objects in that facility.
- the interrogator can include circuitry for automatically adjusting its transmitter output power and/or receiver sensitivity to achieve 2-way communication with only the single tagged object being handled at a given time.
- a particularly preferred embodiment of the interrogator transceiver automatically adjusts the 2-way communication range by reducing its transmitter RF output power, thereby attaining the additional advantage of reducing its battery consumption.
- the interrogator transceiver initially broadcasts an interrogation signal at a very low transmitter RF output power level. If no tag responds, the interrogator broadcasts the interrogation signal again at a higher power level. If again no tag responds, the interrogator broadcasts the interrogation signal at progressively higher power levels until either a tag responds or the interrogator reaches its maximum transmitter output power. In the latter case, the interrogator waits a certain period of time (for example, 0.2 second), then repeats the process starting with the lowest power level.
- a certain period of time for example, 0.2 second
- the interrogator When a tag does respond to an interrogation signal which the interrogator transmitted at a given power level, the interrogator maintains that power level for all subsequent transmissions to that tag. Thus, the interrogator employs the lowest transmitter power needed to communicate with the tag, thereby minimizing power drain from the interrogator's battery. Furthermore, when the interrogator or its antenna is close to a tag (as when the operator is grasping or handling a tagged object), this embodiment of the interrogator inherently adjusts its transmitter output power to a level just high enough to reliably communicate with the closest tag, but not high enough to communicate with other, more distant tags. Therefore, this embodiment of the interrogator performs automatically the adjustment of 2-way communication range described earlier. The adjustment steps preferably are implemented by programming the control logic circuit 56 .
- each tag is a passive RF transceiver, also called a modulated backscatter RF transceiver.
- a passive RF transceiver also called a modulated backscatter RF transceiver.
- Such a transceiver responds to an interrogator signal by modulating the RF carrier of the interrogator signal with the itinerary information and reflecting or re-radiating the modulated signal back toward the interrogator. Examples of modulated backscatter transceivers are described in U.S. Pat. No. 3,832,530 issued Aug. 27, 1974 to Reitboeck et al.; U.S. Pat. No. 4,075,632 issued Feb. 21, 1978 to Baldwin et al.; U.S. Pat. No.
- the mounting location of the antenna 50 of the interrogator also affects the ability of the interrogator to discriminate against suitcases other than the one currently being handled by the operator.
- the most convenient and unobtrusive location of the antenna typically is in the same housing as the interrogator transceiver 20 , which, as described above, may be attached to the operator's clothing such as a belt 22 worn around the operator's waist.
- the distance from the operator's torso to the suitcase being handled should be much smaller than the distance from the operator's torso to any nearby suitcases. If the suitcases are too close together to satisfy this condition, then it is preferable to mount the antenna of the interrogator transceiver on the operator's hand, wrist, or forearm so that the operator can extend his arm toward the tag mounted on the individual suitcase the operator currently is handling, thereby reducing the distance between interrogator antenna and the tag.
- the antenna 50 of the interrogator transceiver can be mounted in a wrist strap worn on the operator's wrist (see FIG. 4 ). If the tag is attached to the handle of a suitcase, then the interrogator antenna will be closest to the tag (a distance of only two or three inches) when the operator grasps the suitcase handle.
- the 2-way communication range between the interrogator and tags should be adjusted, as described above, so that the “reliable 2-way communications inner zone” is only slightly greater than this closest distance (i.e., a few inches).
- the “zero 2-way communication outer zone” boundary is on the order of one foot from the interrogator antenna, whereby the suitcase being handled will be within the inner zone and all other suitcases will be outside the boundary of the outer zone.
- the antenna and interrogator can be fabricated as an integral unit which is mounted on the operator's hand, wrist, or forearm, if the interrogator is small enough to be worn comfortably in this manner.
- the tag will receive an interrogation signal from the interrogator and will respond with a message identifying itself to the interrogator.
- the interrogator then should present to the operator relevant portions of the identifying information, such as airline flight number or destination.
- the information can be presented aurally or visually.
- the identifying information can be presented aurally through a loudspeaker mounted in the same enclosure as the interrogator. More preferably, to prevent operators in the same vicinity from disturbing each other, the information can be presented through headphones or similar sound transducers worn or in or adjacent to the operator's ears. Alternatively, the information can be presented visually by a small video display panel mounted on the same enclosure as the interrogator or, more preferably, by a conventional heads-up display incorporated in eye goggles or eyeglasses worn by the operator.
- the information the interrogator presents to the baggage handling operator when he picks up a suitcase typically would be the flight number of the aircraft on which the suitcase belongs and the destination city of the suitcase. Using this information, the operator then loads the suitcase into the container or truck designated for that flight number.
- the invention also is useful for baggage handling operators who unload suitcases from an arriving aircraft. Because a given flight typically stops in several destination cities, the baggage unloading operators in a given destination city must ensure they only unload baggage whose intended destination is that city.
- the name or identification code for the current city should be stored in a semiconductor memory in each operator's interrogator.
- the interrogator should be programmed to compare the stored city code with the destination city information transmitted by each tagged object handled by the operator. In case the intended destination transmitted by a tag differs from the actual destination stored in the interrogator's memory, the interrogator should present an audible or visual error warning to the operator. For example, the interrogator might contain a green light which flashes when the operator picks up a suitcase whose tag designates the same destination stored in the interrogator, and a red light which flashes when the tag designates a different destination.
- each operator can share a central control center 80 located in their work area.
- the interrogator of each operator can transmit RF signals to the central control center using the same transceiver which the interrogator uses to communicate with the tags. Specifically, each interrogator should transmit to the control center RF message signals containing the identifying information received from tags plus the interrogator's own identification number.
- the control center can display the information received from all the operators' interrogators on a single video display 82 , or the control center can present the information in audible form over a loudspeaker 84 which all the operators in the vicinity can hear.
- each tag should be accompanied by the name or other identification of the operator who is handling the tagged suitcase, that is, the operator whose interrogator received the information from the tag. For example, in a video display, each operator's name 86 should be displayed next to the identifying information 88 from the tag of the suitcase he currently is handling. With an audio transducer, each operator's name should be pronounced immediately before presenting the identifying information for the suitcase that operator currently is handling.
- the control center 80 can include a computer which functions as a central database which stores a record of which suitcases have been handled and by which operators.
- the central database can be used to track the progress of the suitcases from one location to another. In case a suitcase is misdirected, the database can help identify which operator was responsible for the error.
- An alternative embodiment of the invention does not necessarily limit the interrogator to communicating with a single tag as in the preceding embodiments. Instead, the objective of this alternative embodiment is to prevent one operator's interrogator from communicating with tagged objects being handled by other operators working nearby in the same facility.
- the 2-way communication range between one operator's interrogator and the tags is adjusted so that all tagged objects being handled by other operator personnel are outside the range. As in the preceding embodiments, the adjustment may be performed by adjusting the transmitter output power and/or the receiver sensitivity in the interrogator transceiver, in the RFID tags, or in both. Unlike the preceding embodiments, the 2-way communication range between the interrogator and the tags need not be so short that only one tagged object at a time can be within the range.
- the invention has been described in the context of an aircraft baggage handling facility. Nevertheless, the invention is equally useful in other transportation facilities for sorting or handling cargo or goods to be transported in vehicles other than airplanes. More generally, the invention is equally useful in any facility in which human operators handle or monitor any type of objects to which conventional RFID tags can be affixed.
Abstract
Description
- The invention relates generally to RF identification tags and interrogators, that is, to systems for identifying objects by communication between a radio frequency transceiver mounted on each object (RF identification “tag”) and a radio frequency transceiver “interrogator”. More specifically, the invention relates to such a system in which one or more human operators each has his own interrogator, and in which the 2-way communication range between each operator's interrogator transceiver and the tags is adjusted so as to prevent communications between the interrogator and more distant tags.
- Radio frequency identification (RFID) systems have been proposed for identifying tagged objects for such purposes as taking inventory or tracking movements of objects being transported. Examples are described in commonly assigned U.S. Pat. Nos. 5,300,875; 5,365,551; and 5,448,110.
- RFID systems generally employ a passive or active RF transceiver, called a “tag”, mounted on each object to be identified or tracked. An interrogator transceiver periodically transmits RF interrogation signals. Upon receiving an interrogation signal, a tag responds by transmitting a response signal containing data which identifies the object and contains any other information which may have been stored or programmed in the tag.
- Conventional RFID systems provide little or no interactive feedback in response to actions performed by handling personnel. Specifically, conventional RFID systems lack any means for discriminating in favor of an individual tagged object a human operator is working with at any given moment; instead, conventional RFID systems generally would confuse the operator by providing information regarding all the tagged objects in the vicinity. Furthermore, if a number of personnel are working close to each other, conventional RFID systems cannot direct information about a tag to the specific individual who is handling the tagged object.
- For example, suppose a number of airport baggage handler personnel are sorting or routing tagged suitcases according to the airline flight destination encoded in a tag attached to each suitcase. Conventional RFID systems lack any means for detecting which individual suitcase a human operator or baggage handler is about to pick up so as to provide to the operator only the destination or routing information for the suitcase that person currently is handling, to the exclusion of information about other nearby suitcases. Presumably because of this and other shortcomings of conventional RFID systems, RFID tags never entered commercial use for tagging airline baggage.
- The present invention is a method of adjusting the 2-way communication range of an RFID system to assist a human operator to individually handle and interrogate a plurality of tagged objects, such as suitcases, which each include an RFID tag transceiver. An RFID interrogator transceiver, preferably mounted on the operator, periodically broadcasts interrogation messages. Any tag transceiver which is within 2-way communication range of the interrogator receives the broadcasted message and responds by transmitting an identifying message containing data identifying the tagged object. The interrogator transceiver receives the response message from the tag and presents to the operator the identifying data contained in the response message, typically via an aural transducer or visual display.
- In a first embodiment of the present invention, the 2-way communication range between the interrogator transceiver and the tag transceivers is adjusted to only slightly exceed the closest distance between the interrogator and the tag while the operator is handling the tagged object. Consequently, other tagged objects will remain outside the communication range and will not respond to interrogation messages. Therefore, the operator can be confident that the identifying information he receives from the interrogator pertains to the individual tagged object which the operator currently is handling, rather than pertaining to other tagged objects nearby.
- The interrogator transceiver can be mounted anywhere on the operator's person so as to leave both of the operator's hands free for handling the tagged objects. For example, the interrogator can be mounted on the person's belt. Furthermore, the interrogator can have an antenna mounted separately, preferably on the operator's wrist band or similarly near the person's hand, so that the operator can extend his hand toward a tagged object to bring the antenna within close communication range of the RFID tag on the object. This allows reducing the communication range so as to minimize the possibility of responses from RFID tags other than the one associated with the individual tagged object which the operator currently is handling.
- A second embodiment of the invention does not necessarily limit the interrogator to communicating with a single tag as in the first embodiment. Instead, an objective of the second embodiment is to prevent one operator's interrogator from communicating with tagged objects being handled by other operators working nearby in the same facility. In this embodiment, the 2-way communication range between one operator's interrogator and the tags is adjusted so that all tagged objects being handled by other operator personnel are outside the range. Unlike the first embodiment, the 2-way communication range between the interrogator and the tags need not be so short that only one tagged object at a time can be within the range.
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FIG. 1 is a schematic depiction of an airport baggage sorting facility employing the present invention. -
FIG. 2 is a block diagram of an REID tag transceiver used in the present invention. -
FIG. 3 is a block diagram of an RFID interrogator transceiver used in the present invention. -
FIG. 4 is a schematic depiction of the reliable, unreliable, and zero two-way communications zones surrounding an interrogator transceiver. - The invention will be described in the context of an exemplary implementation, depicted in
FIG. 1 , in which thehuman operators 10 are baggage handler personnel working in an airport baggage sorting facility, and the taggedobjects 12 are airline baggage. However, the invention is equally applicable to any other objects to which RFID tags may be attached. - In the airport example, a number of
baggage handler personnel 10, hereinafter called “operators”, are responsible for loading a large number ofsuitcases 12 and other baggage pieces intovarious freight containers 14, where each freight container has been designated to be loaded on a specific aircraft flight. An operator's job is to read the designated flight number and/or destination from atag 16 attached to each suitcase and then to load the suitcase in the correct freight container. - Personnel at the airport passenger check-in counter attach an
RFID tag 16 to eachsuitcase 12. Preferably, the RFID tag is mounted near ahandle 18 of the suitcase so that an operator's hand will be as close as possible to the tag when the operator grasps the handle to pick up the suitcase. For example, the tag may be attached to the handle by astrap 19, as shown inFIG. 4 . - A
semiconductor memory 38 within the tag is programmed to store information on the itinerary of the suitcase, such as flight number, time, and destination. Optionally, the tag's memory may be programmed with additional information such as the name of the owner and special handling instructions. - The tag's memory can be programmed by any conventional means for storing data in a memory device connected to an RF transceiver. For example, the RF communications protocol used by the tag transceiver can include commands for storing data, so that such commands could be transmitted to the tag's transceiver by a transmitter used by airport check-in personnel. Alternatively, the tag may include physical connectors for connecting the tag to a conventional memory programming apparatus used by airport check-in personnel.
- After mounting an RFID tag on the suitcase, the check-in counter personnel place the suitcase on a
conveyor belt 24 which carries the suitcase to a large baggage sorting facility such as the sorting facility shown inFIG. 1 . The sorting facility includes a plurality offreight containers 14, each container being labelled with the flight number of an aircraft whose baggage is to be loaded into that container by the baggage handler personnel (i.e., the operators). After the operators load the appropriate baggage into a container, the container is wheeled from the baggage sorting facility to the aircraft, where other baggage handler personnel transfer the baggage from the container to the aircraft. The process is performed in reverse when the aircraft reaches its destination. - Each
baggage handling operator 10 in the sorting facility carries a battery-poweredRFID interrogator transceiver 20, the interrogator preferably being attached to the operator's body or clothing so as to leave the operator's hands free and not obstruct the operator's movements. For example, the interrogator may be attached to abelt 22 worn around the operator's waist. (Alternatively, the interrogator may be attached to a strap or belt worn around the operator's leg, arm, or wrist.) As the operator moves within a certain proximity of anindividual suitcase 12, thetag 16 on the suitcase receives an interrogation signal transmitted periodically from the operator'sinterrogator 20. Thetag 16 responds by transmitting a message containing the itinerary information stored in the tag's memory. Theinterrogator 20 receives the message and conveys the itinerary information to the operator, preferably either visually or aurally. The operator uses the itinerary information to decide whichfreight container 14 the suitcase should be loaded into. - When the aircraft reaches its destination, each of the personnel who unload baggage from the airplane preferably also carries an
RFID interrogator 20 attached as described above. Each interrogator carried by the unloading personnel would include memory in which a code representing the city (or airport) in which the interrogator is actually located. The interrogator periodically broadcasts interrogation messages and receives a response from each tagged object picked up by the person carrying the interrogator. Thecontrol logic 56 in the interrogator is programmed to compare the intended destination city transmitted by each tag with the interrogator's actual location city stored inmemory 58. If the intended and actual destinations do not match, the interrogator presents a warning signal to the unloading person to alert him that the piece of baggage he currently is unloading does not belong in that city. - For baggage unloading, an alternative to each unloading person carrying an interrogator is to mount a
single RFID interrogator 20 at each aircraft door through which baggage is unloaded. As described in the preceding paragraph, the interrogator should announce a warning if a piece of baggage exiting the door has an intended destination different from the actual destination stored in the interrogator. The interrogator can be battery-powered for portability, and can be mounted near the aircraft cargo door by any means. Since the interrogator only needs to be mounted during the short time baggage is being unloaded, the mounting means can be temporary. A presently preferred mounting means is a suction cup affixed to the interrogator, allowing it to be temporarily attached to the aircraft skin or door panel. - Mounting an interrogator transceiver adjacent to a cargo door, as described in the preceding paragraph, also is useful when first loading baggage on an aircraft to verify that no baggage is loaded which was intended for a different flight. For purposes of loading rather than unloading, the airplane flight number or similar identification should be stored in the interrogator's
memory 58. Thecontrol logic 56 in the interrogator should be programmed to compare the intended flight number transmitted by each tag to the flight number stored in the interrogator memory, and then signal human personnel in the event of a discrepancy. - Any of the interrogator transceivers described above can re-transmit data received from tags to a
central computer 80. The central computer should include an RF receiver for receiving the data and a memory for storing it. The data stored in the central computer is useful for tracking the progress of baggage in case of an inquiry or a lost object. - The
RFID tag transceivers 16 andRFID interrogator transceiver 20 used in the present invention can be any conventional RFID (radio frequency identification) transceivers, examples of which are described in U.S. Pat. Nos. 4,075,632 to Baldwin et al.; 4,857,893 to Carroll; 4,862,160 to Ekchian et al.; 5,055,659 to Hendrick et al; 5,144,314 to Malmberg et al.; and 5,245,346 to Nishimura et al. The entire contents of each of these patents is hereby incorporated into this patent application. - A preferred physical implementation of an
RFID tag transceiver 16 is described in U.S. Pat. Nos. 5,406,263; 5,448,110; and 5,497,140. A preferred protocol for communications between theinterrogator 20 and thetags 16 is described in U.S. Pat. No. 5,500,650. The entire contents of each of these patents is hereby incorporated into this patent application. -
FIG. 2 shows anRFID tag transceiver 16 suitable for use with the present invention. Anantenna 30 connects to the output of atransmitter 32 and to the input of areceiver 34. Acontrol logic circuit 36, such as a programmable microcomputer, receives data which has been received and demodulated by thereceiver 34, provides data to thetransmitter 32 with which the transmitter is to modulate the transmitted RF signal, and provides control signals to both the receiver and the transmitter. Thecontrol logic circuit 36 also exchanges data with amemory 38. All the components just described are conventionally included in an RFID tag transceiver. As described below, the tag transceiver optionally includes an RFsignal amplitude detector 40. Such amplitude detectors are well known, but are not conventionally included in RFID transceivers. -
FIG. 3 shows anRFID interrogator transceiver 20 suitable for use with the present invention. The interrogator has the same components as the tag, namely, anantenna 50,transmitter 52,receiver 54,control logic circuit 56,memory 58, and optional RFsignal amplitude detector 60. - When the
operator 10 receives itinerary information for asuitcase 12, it is important for the operator to know which suitcase the information pertains to. In the present invention, this is accomplished by limiting the transmitter power and/or the receiver sensitivity of the operator's interrogator, of the tags, or of both so that 2-way communication between the interrogator and the tags is possible only over a very short range. Specifically, the maximum range or distance across which theinterrogator 20 andtags 16 can reliably communicate should be adjusted so that it is only slightly greater than the distance between the antenna of the operator's interrogator and the tag attached to the single suitcase the operator is handling. Allother suitcases 12′ in the baggage handling facility should be outside this range. - More specifically (see
FIG. 4 ), depending on the transmitter power, receiver sensitivity, and antenna radiation pattern of the RFID tags 16 and theinterrogator 20, there will be a “reliable 2-way communication”inner zone 70 surrounding theantenna 50 of the operator's interrogator within which anRFID tag 16 will be close enough to reliably communicate with the interrogator, and a “zero 2-way communication”outer zone 72, defined by aboundary 73 surrounding the inner zone, beyond whichboundary 73 an RFID tag cannot successfully communicate with the operator's interrogator. Between therespective boundaries outer zones intermediate zone 74 within which a tag can communicate with the interrogator with uncertain reliability. - The distance between the
antenna 50 of the operator's interrogator and thetag 16 on a suitcase will be minimum when theoperator 10 grasps thesuitcase 12 to move it to thecontainer 14 for the appropriate aircraft. The reliable 2-way communication range 70 between an operator's interrogator and the nearby tags should be adjusted to only slightly exceed this minimum distance. Specifically, the reliable 2-way communication range should be adjusted so that (i) a suitcase being grasped or otherwise handled by the baggage handling operator is within the “reliable 2-way communication inner zone” surrounding the interrogator's antenna, and (ii) all othernearby suitcases 12′ are outside this inner zone, and preferably are outside the boundary of the “zero 2-way communication” outer zone. If the 2-way communications range is adjusted according to these criteria, only the tag on the single suitcase currently being handled will be close enough for 2-way communication with the operator's interrogator. Therefore, the operator can be confident that the identifying information he receives from the interrogator pertains to theindividual suitcase 12 the operator currently is handling, rather than pertaining toother suitcases 12′ nearby. - An interrogator and tag are considered to be within reliable 2-way communication range of each other only if the tag can reliably receive RF signals from the interrogator and the interrogator can reliably receive RF signals from the tag. If RF signals can be reliably received by the interrogator from the tag, but not by the tag from the interrogator—or vice versa—then only one-way reliable communication is possible, and the interrogator and tag are not considered within reliable 2-way communication range. In other words, the reliable 2-way communication range is the lesser of (a) the maximum distance over which the interrogator can reliably receive RF signals from the tag, and (b) the maximum distance over which the tag can reliably receive RF signals from the interrogator.
- Consequently, the reliable 2-way communication range can be reduced by reducing the reliable one-way communication range in either direction, that is, by reducing either the tag-to-interrogator one-way range “a” or the interrogator-to-tag one-way range “b” defined in the preceding paragraph.
- The one-way communication range from the tags to the operator's interrogator (range “a” defined above) can be reduced either by reducing the transmitter power of all the tags which otherwise could be within communication range of the interrogator or by reducing the receiver sensitivity of the interrogator. Conversely, the one-way communication range from the operator's interrogator to the tags (range “b” defined above) can be reduced either by reducing the transmitter power of the interrogator or by reducing the receiver sensitivity of all the tags which otherwise could be within communication range of the interrogator.
- There are various conventional circuit designs for adjusting transmitter output power or receiver sensitivity. For example, to permit adjusting the sensitivity of the receiver section of each tag and/or the interrogator, the receiver section can include a
conventional circuit control logic circuit - The adjustments to the transmitter power and/or receiver sensitivity of the tags and interrogators can be made at the time of their manufacture. The adjustments to an interrogator also can be performed when the interrogator is placed in service in a given facility, thereby permitting customization of the communication range based on the actual distances between the interrogator and the tagged objects in that facility. Alternatively, the interrogator can include circuitry for automatically adjusting its transmitter output power and/or receiver sensitivity to achieve 2-way communication with only the single tagged object being handled at a given time.
- A particularly preferred embodiment of the interrogator transceiver automatically adjusts the 2-way communication range by reducing its transmitter RF output power, thereby attaining the additional advantage of reducing its battery consumption. In this embodiment, the interrogator transceiver initially broadcasts an interrogation signal at a very low transmitter RF output power level. If no tag responds, the interrogator broadcasts the interrogation signal again at a higher power level. If again no tag responds, the interrogator broadcasts the interrogation signal at progressively higher power levels until either a tag responds or the interrogator reaches its maximum transmitter output power. In the latter case, the interrogator waits a certain period of time (for example, 0.2 second), then repeats the process starting with the lowest power level.
- When a tag does respond to an interrogation signal which the interrogator transmitted at a given power level, the interrogator maintains that power level for all subsequent transmissions to that tag. Thus, the interrogator employs the lowest transmitter power needed to communicate with the tag, thereby minimizing power drain from the interrogator's battery. Furthermore, when the interrogator or its antenna is close to a tag (as when the operator is grasping or handling a tagged object), this embodiment of the interrogator inherently adjusts its transmitter output power to a level just high enough to reliably communicate with the closest tag, but not high enough to communicate with other, more distant tags. Therefore, this embodiment of the interrogator performs automatically the adjustment of 2-way communication range described earlier. The adjustment steps preferably are implemented by programming the
control logic circuit 56. - In a preferred embodiment of the RFID tags, which advantageously limits the 2-way communication range between the tags and the interrogator, each tag is a passive RF transceiver, also called a modulated backscatter RF transceiver. Such a transceiver responds to an interrogator signal by modulating the RF carrier of the interrogator signal with the itinerary information and reflecting or re-radiating the modulated signal back toward the interrogator. Examples of modulated backscatter transceivers are described in U.S. Pat. No. 3,832,530 issued Aug. 27, 1974 to Reitboeck et al.; U.S. Pat. No. 4,075,632 issued Feb. 21, 1978 to Baldwin et al.; U.S. Pat. No. 4,857,893 issued Aug. 15, 1989 to Carroll; and U.S. Pat. No. 5,313,211 issued May 17, 1994 to Tokuda et al.; the entire contents of each of which are hereby incorporated into this patent specification. The amplitude of the RF signal received by the interrogator from a modulated backscatter tag will decline approximately in proportion to the fourth power of the distance between the respective antennas of the tag and the interrogator, assuming both antennas are fairly omnidirectional. In contrast, if the tags had active transmitters with fixed output power, the amplitude would decline only in proportion to the square of the distance.
- Using the just described RFID tags with modulated backscatter RF transceivers in combination with the previously described preferred interrogator with automatically adjusting transmitter power, I have found that the interrogator reliably communicates with a tagged
suitcase 12 when it is grasped by a human operator, while reliably ignoring the tags onother suitcases 12′ nearby. - The mounting location of the
antenna 50 of the interrogator also affects the ability of the interrogator to discriminate against suitcases other than the one currently being handled by the operator. The most convenient and unobtrusive location of the antenna typically is in the same housing as theinterrogator transceiver 20, which, as described above, may be attached to the operator's clothing such as abelt 22 worn around the operator's waist. With the interrogator and its antenna mounted on the operator's torso, the required 2-way communication range between the interrogator and the tag depends on how close the operator's torso approaches the suitcase during normal handling. - To prevent tags on adjacent suitcases from responding to the interrogator, the distance from the operator's torso to the suitcase being handled should be much smaller than the distance from the operator's torso to any nearby suitcases. If the suitcases are too close together to satisfy this condition, then it is preferable to mount the antenna of the interrogator transceiver on the operator's hand, wrist, or forearm so that the operator can extend his arm toward the tag mounted on the individual suitcase the operator currently is handling, thereby reducing the distance between interrogator antenna and the tag.
- For example, the
antenna 50 of the interrogator transceiver can be mounted in a wrist strap worn on the operator's wrist (seeFIG. 4 ). If the tag is attached to the handle of a suitcase, then the interrogator antenna will be closest to the tag (a distance of only two or three inches) when the operator grasps the suitcase handle. The 2-way communication range between the interrogator and tags should be adjusted, as described above, so that the “reliable 2-way communications inner zone” is only slightly greater than this closest distance (i.e., a few inches). Preferably, a consequence of this adjustment is that the “zero 2-way communication outer zone” boundary is on the order of one foot from the interrogator antenna, whereby the suitcase being handled will be within the inner zone and all other suitcases will be outside the boundary of the outer zone. - The antenna and interrogator can be fabricated as an integral unit which is mounted on the operator's hand, wrist, or forearm, if the interrogator is small enough to be worn comfortably in this manner.
- As described above, when a human operator approaches close enough to a tagged suitcase for the operator's interrogator and the tag to be within 2-way communication range, the tag will receive an interrogation signal from the interrogator and will respond with a message identifying itself to the interrogator. The interrogator then should present to the operator relevant portions of the identifying information, such as airline flight number or destination. The information can be presented aurally or visually.
- Specifically, the identifying information can be presented aurally through a loudspeaker mounted in the same enclosure as the interrogator. More preferably, to prevent operators in the same vicinity from disturbing each other, the information can be presented through headphones or similar sound transducers worn or in or adjacent to the operator's ears. Alternatively, the information can be presented visually by a small video display panel mounted on the same enclosure as the interrogator or, more preferably, by a conventional heads-up display incorporated in eye goggles or eyeglasses worn by the operator.
- In the previously described example of an aircraft baggage sorting facility for loading baggage onto departing aircraft, the information the interrogator presents to the baggage handling operator when he picks up a suitcase typically would be the flight number of the aircraft on which the suitcase belongs and the destination city of the suitcase. Using this information, the operator then loads the suitcase into the container or truck designated for that flight number.
- The invention also is useful for baggage handling operators who unload suitcases from an arriving aircraft. Because a given flight typically stops in several destination cities, the baggage unloading operators in a given destination city must ensure they only unload baggage whose intended destination is that city. For this application, the name or identification code for the current city should be stored in a semiconductor memory in each operator's interrogator. The interrogator should be programmed to compare the stored city code with the destination city information transmitted by each tagged object handled by the operator. In case the intended destination transmitted by a tag differs from the actual destination stored in the interrogator's memory, the interrogator should present an audible or visual error warning to the operator. For example, the interrogator might contain a green light which flashes when the operator picks up a suitcase whose tag designates the same destination stored in the interrogator, and a red light which flashes when the tag designates a different destination.
- As an alternative to each operator's carrying or wearing an audio transducer or video display as just described, several operators working in the same area or facility can share a
central control center 80 located in their work area. The interrogator of each operator can transmit RF signals to the central control center using the same transceiver which the interrogator uses to communicate with the tags. Specifically, each interrogator should transmit to the control center RF message signals containing the identifying information received from tags plus the interrogator's own identification number. The control center can display the information received from all the operators' interrogators on asingle video display 82, or the control center can present the information in audible form over aloudspeaker 84 which all the operators in the vicinity can hear. - If multiple operator personnel share a central audio transducer or visual display, the presentation of information from each tag should be accompanied by the name or other identification of the operator who is handling the tagged suitcase, that is, the operator whose interrogator received the information from the tag. For example, in a video display, each operator's
name 86 should be displayed next to the identifyinginformation 88 from the tag of the suitcase he currently is handling. With an audio transducer, each operator's name should be pronounced immediately before presenting the identifying information for the suitcase that operator currently is handling. - Whether or not a shared control center presents information to the operators as just described, the
control center 80 can include a computer which functions as a central database which stores a record of which suitcases have been handled and by which operators. The central database can be used to track the progress of the suitcases from one location to another. In case a suitcase is misdirected, the database can help identify which operator was responsible for the error. - An alternative embodiment of the invention does not necessarily limit the interrogator to communicating with a single tag as in the preceding embodiments. Instead, the objective of this alternative embodiment is to prevent one operator's interrogator from communicating with tagged objects being handled by other operators working nearby in the same facility. In this embodiment, the 2-way communication range between one operator's interrogator and the tags is adjusted so that all tagged objects being handled by other operator personnel are outside the range. As in the preceding embodiments, the adjustment may be performed by adjusting the transmitter output power and/or the receiver sensitivity in the interrogator transceiver, in the RFID tags, or in both. Unlike the preceding embodiments, the 2-way communication range between the interrogator and the tags need not be so short that only one tagged object at a time can be within the range.
- The invention has been described in the context of an aircraft baggage handling facility. Nevertheless, the invention is equally useful in other transportation facilities for sorting or handling cargo or goods to be transported in vehicles other than airplanes. More generally, the invention is equally useful in any facility in which human operators handle or monitor any type of objects to which conventional RFID tags can be affixed.
Claims (42)
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Cited By (12)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US20060202802A1 (en) * | 2003-05-12 | 2006-09-14 | Seppae Heikki | Remote sensor, device and method for activating selected remote sensor components |
US20070066223A1 (en) * | 2005-02-28 | 2007-03-22 | Sirit, Inc. | Power control loop and LO generation method |
US20070252697A1 (en) * | 1998-03-27 | 2007-11-01 | Micron Technology, Inc. | Method and system for identifying missing items |
US20090036082A1 (en) * | 2007-07-31 | 2009-02-05 | Mohammed Sajid | Canceling self-jammer and interfering signals in an rfid system |
US20090210517A1 (en) * | 2002-05-30 | 2009-08-20 | Sony Corporation | Information management device and method, information processing device and method recording medium, and program |
US7808367B2 (en) | 1999-08-09 | 2010-10-05 | Round Rock Research, Llc | RFID material tracking method and apparatus |
US20110082810A1 (en) * | 2008-01-10 | 2011-04-07 | Walt-Task, Llc | Human-readable baggage and cargo routing identification system |
US8289164B2 (en) | 2003-12-12 | 2012-10-16 | Semiconductor Energy Laboratory Co., Ltd. | Semiconductor device and manufacturing method thereof |
US9171448B1 (en) * | 2014-06-11 | 2015-10-27 | Target Brands, Inc. | RFID tags for locating products |
US20180204030A1 (en) * | 2017-01-13 | 2018-07-19 | International Business Machines Corporation | Baggage handling |
CN108573182A (en) * | 2018-04-26 | 2018-09-25 | 深圳市盛路物联通讯技术有限公司 | A kind of radio frequency signal communication method and system |
US20210072375A1 (en) * | 2017-05-10 | 2021-03-11 | Google Llc | Low-Power Radar |
Families Citing this family (190)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US6097301A (en) * | 1996-04-04 | 2000-08-01 | Micron Communications, Inc. | RF identification system with restricted range |
US20050040961A1 (en) * | 1995-04-11 | 2005-02-24 | Tuttle John R. | RF identification system with restricted range |
US6804726B1 (en) * | 1996-05-22 | 2004-10-12 | Geovector Corporation | Method and apparatus for controlling electrical devices in response to sensed conditions |
US6369709B1 (en) | 1998-04-10 | 2002-04-09 | 3M Innovative Properties Company | Terminal for libraries and the like |
US6420961B1 (en) | 1998-05-14 | 2002-07-16 | Micron Technology, Inc. | Wireless communication systems, interfacing devices, communication methods, methods of interfacing with an interrogator, and methods of operating an interrogator |
ATE352829T1 (en) * | 1998-08-14 | 2007-02-15 | 3M Innovative Properties Co | APPLICATION FOR RADIO FREQUENCY IDENTIFICATION SYSTEMS |
EP1145189B1 (en) * | 1998-08-14 | 2008-05-07 | 3M Innovative Properties Company | Radio frequency identification systems applications |
US7283061B1 (en) * | 1998-08-28 | 2007-10-16 | Marathon Oil Company | Method and system for performing operations and for improving production in wells |
US20040239521A1 (en) * | 2001-12-21 | 2004-12-02 | Zierolf Joseph A. | Method and apparatus for determining position in a pipe |
US6513015B2 (en) * | 1998-09-25 | 2003-01-28 | Fujitsu Limited | System and method for customer recognition using wireless identification and visual data transmission |
GB9821046D0 (en) * | 1998-09-28 | 1998-11-18 | Whitesmith Howard W | Detection system |
US6360208B1 (en) * | 1999-02-04 | 2002-03-19 | Intermec Ip Corp. | Method and apparatus for automatic tax verification |
US6286762B1 (en) * | 1999-09-21 | 2001-09-11 | Intermec Ip Corp. | Method and apparatus to perform a predefined search on data carriers, such as RFID tags |
US6318636B1 (en) * | 1999-09-21 | 2001-11-20 | Intermec Ip Corp. | Method and apparatus to read different types of data carriers, such RFID tags and machine-readable symbols, and a user interface for the same |
US6286763B1 (en) * | 1999-09-21 | 2001-09-11 | Intermac Ip Corp. | Method and apparatus to automatically search data carriers, such as RFID tags and machine-readable symbols |
US6714133B2 (en) * | 1999-12-15 | 2004-03-30 | Koninklijke Philips Electronics N.V. | Short range communication system |
US6650254B1 (en) | 2000-03-13 | 2003-11-18 | Ergodex | Computer input device with individually positionable and programmable switches |
US6943665B2 (en) | 2000-03-21 | 2005-09-13 | T. Eric Chornenky | Human machine interface |
US20030098774A1 (en) * | 2000-03-21 | 2003-05-29 | Chornenky Todd E. | Security apparatus |
AU2001250044A1 (en) * | 2000-03-21 | 2001-10-03 | T. Eric CHORNENKY | Security apparatus |
US7064669B2 (en) * | 2000-06-09 | 2006-06-20 | Light Elliott D | Electronic tether for portable objects |
GB0015147D0 (en) * | 2000-06-21 | 2000-08-09 | Jacobs Michael | Tracking system |
US20020044058A1 (en) * | 2000-08-17 | 2002-04-18 | Heinrich Harley Kent | Wrist mounted RFID reader and/or antenna |
US6552661B1 (en) * | 2000-08-25 | 2003-04-22 | Rf Code, Inc. | Zone based radio frequency identification |
US6883710B2 (en) * | 2000-10-11 | 2005-04-26 | Amerasia International Technology, Inc. | Article tracking system and method |
EP1514247B1 (en) * | 2000-10-16 | 2013-01-16 | Amerasia International Technology, Inc. | Article tracking system and method |
US6789729B1 (en) * | 2000-11-02 | 2004-09-14 | Ford Motor Company | Method for receiving and shipping items |
WO2002047014A1 (en) * | 2000-12-07 | 2002-06-13 | Sap Aktiengesellschaft | System, method, computer program product for communicating data for objects that are transported |
US6600418B2 (en) | 2000-12-12 | 2003-07-29 | 3M Innovative Properties Company | Object tracking and management system and method using radio-frequency identification tags |
EP1220163A1 (en) * | 2000-12-29 | 2002-07-03 | EM Microelectronic-Marin SA | Passage detection system for individuals or objects through an entrance-exit with a limited space |
FR2820518B1 (en) | 2001-02-02 | 2003-04-25 | Siemens Automotive Sa | METHOD FOR MONITORING THE CONDITION OF A SECURITY BODY |
US6774811B2 (en) | 2001-02-02 | 2004-08-10 | International Business Machines Corporation | Designation and opportunistic tracking of valuables |
ATE411577T1 (en) * | 2001-03-08 | 2008-10-15 | Em Microelectronic Marin Sa | SYSTEM FOR DETECTING THE PASSAGE OF PERSONS OR OBJECTS THROUGH A SPATIAL ENTRANCE-EXIT |
US6811903B2 (en) * | 2001-04-06 | 2004-11-02 | Evlonyx, Inc. | Electrochemical cell recharging system |
US6779246B2 (en) | 2001-04-23 | 2004-08-24 | Appleton Papers Inc. | Method and system for forming RF reflective pathways |
US6892441B2 (en) * | 2001-04-23 | 2005-05-17 | Appleton Papers Inc. | Method for forming electrically conductive pathways |
US7014100B2 (en) * | 2001-04-27 | 2006-03-21 | Marathon Oil Company | Process and assembly for identifying and tracking assets |
US7248933B2 (en) * | 2001-05-08 | 2007-07-24 | Hill-Rom Services, Inc. | Article locating and tracking system |
US7242306B2 (en) * | 2001-05-08 | 2007-07-10 | Hill-Rom Services, Inc. | Article locating and tracking apparatus and method |
US7376234B1 (en) | 2001-05-14 | 2008-05-20 | Hand Held Products, Inc. | Portable keying device and method |
US6942155B1 (en) * | 2001-05-31 | 2005-09-13 | Alien Technology Corporation | Integrated circuits with persistent data storage |
US7377445B1 (en) | 2001-05-31 | 2008-05-27 | Alien Technology Corporation | Integrated circuits with persistent data storage |
US7030760B1 (en) | 2001-08-07 | 2006-04-18 | Seecontrol, Inc. | Method and apparatus for ensuring reliable loading of materials on aricraft and other vehicles |
US7635087B1 (en) | 2001-10-01 | 2009-12-22 | Avante International Technology, Inc. | Method for processing a machine readable ballot and ballot therefor |
US7828215B2 (en) * | 2001-10-01 | 2010-11-09 | Avante International Technology, Inc. | Reader for an optically readable ballot |
US7077313B2 (en) | 2001-10-01 | 2006-07-18 | Avante International Technology, Inc. | Electronic voting method for optically scanned ballot |
EP1308864A1 (en) * | 2001-11-02 | 2003-05-07 | Hewlett-Packard Company | Passenger management system and method and electronic device |
US6669089B2 (en) | 2001-11-12 | 2003-12-30 | 3M Innovative Properties Co | Radio frequency identification systems for asset tracking |
US7374096B2 (en) | 2001-11-21 | 2008-05-20 | Goliath Solutions, Llc | Advertising compliance monitoring system |
US6951305B2 (en) * | 2001-11-21 | 2005-10-04 | Goliath Solutions, Llc. | Advertising compliance monitoring system |
US6837427B2 (en) * | 2001-11-21 | 2005-01-04 | Goliath Solutions, Llc. | Advertising compliance monitoring system |
FR2834398B1 (en) * | 2001-12-27 | 2005-06-03 | Siemens Vdo Automotive | METHOD FOR TRANSMITTING A REQUEST TO A BADGE |
SE523990C2 (en) * | 2001-12-28 | 2004-06-15 | Abb Ab | Procedures and systems in an industrially automated facility to send relevant plant information to mobile devices depending on their location |
US7406439B2 (en) * | 2002-01-31 | 2008-07-29 | International Business Machines Corporation | Inventory controls with radio frequency identification |
JP3497499B2 (en) * | 2002-03-14 | 2004-02-16 | 三菱電機株式会社 | 3D graphic drawing device |
JP2006508412A (en) * | 2002-03-18 | 2006-03-09 | イル・ガット・インコーポレーテッド | System and method for monitoring and tracking individuals |
US20040111359A1 (en) * | 2002-06-04 | 2004-06-10 | Hudock John J. | Business method for credit verification and correction |
US6933849B2 (en) | 2002-07-09 | 2005-08-23 | Fred Sawyer | Method and apparatus for tracking objects and people |
US7080779B2 (en) * | 2002-07-26 | 2006-07-25 | Automark Technical Systems, Llc | Ballot marking system and apparatus |
CA2397501A1 (en) * | 2002-08-19 | 2004-02-19 | Emerson Nerat | Wireless smart system for tracking luggage |
US7002472B2 (en) * | 2002-09-04 | 2006-02-21 | Northrop Grumman Corporation | Smart and secure container |
US6903662B2 (en) * | 2002-09-19 | 2005-06-07 | Ergodex | Computer input device with individually positionable and programmable input members |
AU2003275297A1 (en) * | 2002-09-27 | 2004-04-23 | Hill-Rom Services, Inc. | Universal communications, monitoring, tracking, and control system for a healthcare facility |
US6987948B2 (en) * | 2002-10-03 | 2006-01-17 | Wildseed Ltd. | Identification based operational modification of a portable electronic device |
US7431436B1 (en) | 2002-11-12 | 2008-10-07 | Vutek, Incorporated | Identification system for inks in printing systems |
GB2395592B (en) * | 2002-11-21 | 2006-05-17 | Hewlett Packard Co | Method of annotating an item with electronic data and apparatus therefor |
US7636568B2 (en) * | 2002-12-02 | 2009-12-22 | The Boeing Company | Remote aircraft manufacturing, monitoring, maintenance and management system |
GB2396004B (en) * | 2002-12-06 | 2006-02-22 | Optex Co Ltd | Anti-thief security sensor assembly with variable amount of emitted infrared beam |
GB0230360D0 (en) * | 2002-12-27 | 2003-02-05 | Koninkl Philips Electronics Nv | Object identifying method and apparatus |
US7314172B2 (en) * | 2003-01-17 | 2008-01-01 | Automark Technical Systems, Llc | Ballot marking system and apparatus having periodic ballot alignment compensation |
US20040186768A1 (en) * | 2003-03-21 | 2004-09-23 | Peter Wakim | Apparatus and method for initiating remote content delivery by local user identification |
US7538745B2 (en) * | 2003-03-24 | 2009-05-26 | Ntag Interactive Corporation | Apparatus and method for enhancing face-to-face communication |
EP1625525A4 (en) * | 2003-03-24 | 2010-01-27 | Ntag Interactive Corp | Apparatus and method for enhancing face-to-face communication |
US6970092B2 (en) * | 2003-04-15 | 2005-11-29 | Koninklijke Philips Electronics,N.V. | Short range communication system |
US8063885B2 (en) * | 2003-06-04 | 2011-11-22 | Es&S Automark, Llc | Ballot marking system and apparatus utilizing pivotal touchscreen |
WO2004109583A1 (en) * | 2003-06-06 | 2004-12-16 | Stemco Llc | Wireless communication device, system for communication and communication method |
JP4624361B2 (en) * | 2003-10-29 | 2011-02-02 | エヌエックスピー ビー ヴィ | Communication partner device with automatic transmission mode activation |
US20050094825A1 (en) * | 2003-10-30 | 2005-05-05 | Loness Gene A. | Remotely controlled sound generator |
US7290287B2 (en) * | 2003-11-20 | 2007-10-30 | International Business Machines Corporation | Security screening of electronic devices by device identifier |
US8085132B2 (en) * | 2003-12-10 | 2011-12-27 | Barry Allen | Method and apparatus for resolving RFID-based object traffic transactions to a single object in the presence of a plurality of objects |
US7345576B2 (en) * | 2003-12-10 | 2008-03-18 | Identec Solutions Inc. | Method and apparatus for resolving RFID-based object traffic transactions to a single container in the presence of a plurality of containers |
US8061600B2 (en) * | 2003-12-18 | 2011-11-22 | Altierre Corporation | Wireless display tag |
JP4726037B2 (en) * | 2004-01-20 | 2011-07-20 | オムロンオートモーティブエレクトロニクス株式会社 | Transponder start control method and tire condition monitoring system interrogator |
US20050280508A1 (en) * | 2004-02-24 | 2005-12-22 | Jim Mravca | System and method for controlling range of successful interrogation by RFID interrogation device |
US20050184150A1 (en) * | 2004-02-24 | 2005-08-25 | Welte Gregory A. | Device to prevent credit card loss |
US7574608B2 (en) * | 2004-03-04 | 2009-08-11 | International Business Machines Corporation | Security screening of electronic devices by device-reported data |
US7030761B2 (en) * | 2004-03-16 | 2006-04-18 | Symbol Technologies | Multi-resolution object location system and method |
JP2005309844A (en) * | 2004-04-22 | 2005-11-04 | Ntt Docomo Inc | Management system and management method |
US7003374B2 (en) * | 2004-04-28 | 2006-02-21 | Goodrich Corporation | Aircraft cargo loading logistics system using machine readable identifiers |
US7100827B2 (en) * | 2004-04-28 | 2006-09-05 | Goodrich Corporation | Aircraft cargo loading logistics system |
US7198227B2 (en) * | 2004-06-10 | 2007-04-03 | Goodrich Corporation | Aircraft cargo locating system |
WO2005124669A2 (en) * | 2004-06-15 | 2005-12-29 | Koninklijke Philips Electronics N.V. | Radio identification with an additional close-range check |
US20060007000A1 (en) * | 2004-07-07 | 2006-01-12 | Rosita Yap | File indexing and retrieval system employing RFID visual indicators |
US7403120B2 (en) * | 2004-09-29 | 2008-07-22 | Symbol Technologies, Inc. | Reverse infrastructure location system and method |
US7195159B2 (en) * | 2004-10-22 | 2007-03-27 | Symbol Technologies, Inc. | Radio frequency identification (RFID) material tracking and apparatus |
US7243476B2 (en) * | 2004-12-03 | 2007-07-17 | Checkpoint Systems, Inc. | Method and system for tracking items in a shipping facility |
US20060152364A1 (en) * | 2004-12-30 | 2006-07-13 | Walton Charles A | RFID with field changeable identification |
US7446644B2 (en) * | 2005-01-14 | 2008-11-04 | Secureall Corporation | Universal hands free key and lock system |
US7429984B2 (en) * | 2005-02-04 | 2008-09-30 | Philip Morris Usa Inc. | Display management system |
US8624740B2 (en) * | 2005-02-04 | 2014-01-07 | Philip Morris Usa Inc. | Controllable RFID card |
US20060178110A1 (en) * | 2005-02-09 | 2006-08-10 | Nokia Corporation | System and method for interacting with an entity by means of a mobile station via a user-wearable terminal |
US20060195354A1 (en) * | 2005-02-28 | 2006-08-31 | Ntag Interactive Corporation | Method of scoring the performance of attendees at a meeting |
WO2006093992A2 (en) * | 2005-03-01 | 2006-09-08 | I.D. Systems, Inc. | Mobile portal for rfid applications |
US7242303B2 (en) * | 2005-03-04 | 2007-07-10 | Cisco Technology, Inc. | Navigation and coordination during emergencies |
JP4806954B2 (en) * | 2005-04-15 | 2011-11-02 | オムロン株式会社 | Information processing apparatus, information processing apparatus control method, information processing apparatus control program, and recording medium on which information processing apparatus control program is recorded |
US7330120B2 (en) * | 2005-04-29 | 2008-02-12 | Hewlett-Packard Development Company, L.P. | Remote measurement of motion employing RFID |
US7298272B2 (en) * | 2005-04-29 | 2007-11-20 | Hewlett-Packard Development Company, L.P. | Remote detection employing RFID |
US7330119B2 (en) * | 2005-04-29 | 2008-02-12 | Hewlett-Packard Development Company, L.P. | Remote measurement employing RFID |
JP2006319710A (en) * | 2005-05-13 | 2006-11-24 | Brother Ind Ltd | Wireless tag communication system |
US7271718B2 (en) * | 2005-05-31 | 2007-09-18 | Lucent Technologies Inc. | Protection against loss or theft of identification badges and other items |
US7538670B2 (en) * | 2005-06-20 | 2009-05-26 | Sun Microsystems, Inc. | Method for detecting objects separated from a group |
US7336153B2 (en) * | 2005-06-30 | 2008-02-26 | Hewlett-Packard Development Company, L.P. | Wireless temperature monitoring for an electronics system |
US7607014B2 (en) * | 2005-06-30 | 2009-10-20 | Hewlett-Packard Development Company, L.P. | Authenticating maintenance access to an electronics unit via wireless communication |
US7400252B2 (en) * | 2005-06-30 | 2008-07-15 | Hewlett-Packard Development Company, L.P. | Wireless monitoring of component compatibility in an electronics system |
US7737847B2 (en) * | 2005-06-30 | 2010-06-15 | Hewlett-Packard Development Company, L.P. | Wireless monitoring for an electronics system |
EP1910964A1 (en) * | 2005-07-29 | 2008-04-16 | Alcon, Inc. | Method and system for configuring and data populating a surgical device |
US8587430B2 (en) * | 2005-09-20 | 2013-11-19 | Lyngsoe Systems, Ltd. | Active logistical tag for cargo |
US8199689B2 (en) | 2005-09-21 | 2012-06-12 | Intermec Ip Corp. | Stochastic communication protocol method and system for radio frequency identification (RFID) tags based on coalition formation, such as for tag-to-tag communication |
FR2891933B1 (en) * | 2005-10-07 | 2008-12-26 | Patrick Simonnet | NOMAD DISPATCH OF DIFFUSION OF MULTIMEDIA CONTENT |
DE102005049740A1 (en) * | 2005-10-14 | 2007-04-19 | ASTRA Gesellschaft für Asset Management mbH & Co. KG | Installation for monitoring the manual transfer of goods bearing identification carriers |
US7705733B2 (en) * | 2006-01-06 | 2010-04-27 | Warsaw Orthopedic, Inc. | Coiled RFID tag |
US20070198324A1 (en) * | 2006-02-22 | 2007-08-23 | Borovoy Richard D | Enabling connections between and events attended by people |
US8063746B2 (en) * | 2006-03-31 | 2011-11-22 | Assa Abloy Ab | Transponder detector for an RFID system generating a progression of detection signals |
US20070236334A1 (en) * | 2006-03-31 | 2007-10-11 | Borovoy Richard D | Enhancing face-to-face communication |
US8120461B2 (en) | 2006-04-03 | 2012-02-21 | Intermec Ip Corp. | Automatic data collection device, method and article |
US20070273481A1 (en) * | 2006-05-25 | 2007-11-29 | Symbol Technologies, Inc. | RFID tag with programmable read range |
US7940169B2 (en) * | 2006-06-15 | 2011-05-10 | General Electric Company | System and method for installed base data maintenance |
US20070289164A1 (en) * | 2006-06-16 | 2007-12-20 | Future Chem International Co., Ltd | Footwear having novel shoe upper |
WO2007148287A2 (en) * | 2006-06-19 | 2007-12-27 | Visible Assets, Inc. | Long wave wireless pair-wise linkage using an embedded visibility network |
US20070295817A1 (en) * | 2006-06-22 | 2007-12-27 | Intermec Ip Corp. | Automatic data collection apparatus and method for variable focus using a deformable mirror |
EP1873682A3 (en) * | 2006-06-30 | 2008-10-22 | Siemens Aktiengesellschaft | System and method for obtaining information from objects provided with bar codes and RFID tags |
US8002173B2 (en) | 2006-07-11 | 2011-08-23 | Intermec Ip Corp. | Automatic data collection device, method and article |
WO2008009023A2 (en) * | 2006-07-14 | 2008-01-17 | Emerson Electric Co. | Rfid detection system for enhanced marketing |
US20080042803A1 (en) * | 2006-07-27 | 2008-02-21 | Joshua Posamentier | Adjusting signal strength used to detect tags |
US8061617B2 (en) * | 2006-07-28 | 2011-11-22 | Intermec Ip Corp. | Enhanced resolution automatic data collection apparatus and method using an afocal optical element |
US20080030341A1 (en) * | 2006-08-02 | 2008-02-07 | Taiwan Semiconductor Manufacturing Co., Ltd. | Electronic rack and material management systems utilizing the same |
US7310070B1 (en) | 2006-08-23 | 2007-12-18 | Goliath Solutions, Llc | Radio frequency identification shelf antenna with a distributed pattern for localized tag detection |
JP2008085784A (en) * | 2006-09-28 | 2008-04-10 | Olympus Corp | Mobile device system and mobile device |
US8199004B1 (en) * | 2006-09-29 | 2012-06-12 | Ncr Corporation | RFID tag reader |
US8049616B2 (en) * | 2006-11-30 | 2011-11-01 | Patricia Hill | Method and apparatus for destination tracking with misrouting indication |
US8994533B2 (en) * | 2006-11-30 | 2015-03-31 | Patent Navigation, Inc. | Conditional RFID |
WO2008084353A1 (en) * | 2007-01-08 | 2008-07-17 | Nxp B.V. | Transponders and methods for operating a transponder |
US7546955B2 (en) * | 2007-03-16 | 2009-06-16 | Intermec Ip Corp. | Systems, devices, and methods for reading machine-readable characters and human-readable characters |
US7859416B2 (en) * | 2007-06-21 | 2010-12-28 | Round Rock Research, Llc | Method and system of attaching a RFID tag to an object |
US7916025B2 (en) * | 2007-08-10 | 2011-03-29 | Lockwinn Technology | Intelligent luggage tag |
EP2051100A1 (en) * | 2007-10-19 | 2009-04-22 | Ford Global Technologies, LLC | A method and system for presence detection |
JP5152704B2 (en) * | 2008-01-08 | 2013-02-27 | オムロン株式会社 | Tag communication device, tag communication system, and tag communication method |
US9194227B2 (en) | 2008-03-07 | 2015-11-24 | Marathon Oil Company | Systems, assemblies and processes for controlling tools in a wellbore |
US10119377B2 (en) * | 2008-03-07 | 2018-11-06 | Weatherford Technology Holdings, Llc | Systems, assemblies and processes for controlling tools in a well bore |
WO2009122558A1 (en) * | 2008-03-31 | 2009-10-08 | Iwase Ikuro | Goods manufacturing method, goods manufacturing system, and goods |
ES2396015T3 (en) * | 2008-04-01 | 2013-02-18 | Assa Abloy Ab | Switching capacity method for detecting a wireless transponder device using a single antenna and successive communication with it |
US8717144B2 (en) * | 2008-04-29 | 2014-05-06 | Intelleflex Corporation | RFID system with distributed readers |
US8066184B2 (en) | 2008-04-30 | 2011-11-29 | Avante International Technology, Inc. | Optically readable marking sheet and reading apparatus and method therefor |
US10447334B2 (en) | 2008-07-09 | 2019-10-15 | Secureall Corporation | Methods and systems for comprehensive security-lockdown |
US10128893B2 (en) | 2008-07-09 | 2018-11-13 | Secureall Corporation | Method and system for planar, multi-function, multi-power sourced, long battery life radio communication appliance |
US9642089B2 (en) | 2008-07-09 | 2017-05-02 | Secureall Corporation | Method and system for planar, multi-function, multi-power sourced, long battery life radio communication appliance |
US11469789B2 (en) | 2008-07-09 | 2022-10-11 | Secureall Corporation | Methods and systems for comprehensive security-lockdown |
TWI384248B (en) * | 2008-09-26 | 2013-02-01 | Mstar Semiconductor Inc | Item positioning system and method thereof |
JP5282785B2 (en) * | 2008-10-15 | 2013-09-04 | 富士通株式会社 | Luggage arrangement management method, transport device, and transport control program |
US8644511B2 (en) | 2008-11-05 | 2014-02-04 | Comcast Cable Communications, LLC. | System and method for providing digital content |
US8386261B2 (en) * | 2008-11-14 | 2013-02-26 | Vocollect Healthcare Systems, Inc. | Training/coaching system for a voice-enabled work environment |
US8261985B2 (en) | 2009-04-07 | 2012-09-11 | Avante Corporation Limited | Manual recount process using digitally imaged ballots |
US8356874B2 (en) | 2009-04-08 | 2013-01-22 | Redwood Technologies, Llc | Apparatus and method for precision application and metering of a two-part (binary) imaging solution in an ink jet printer |
US8960880B2 (en) | 2009-04-08 | 2015-02-24 | Redwood Technologies, Llc | Binary epoxy ink and enhanced printer systems, structures, and associated methods |
US8144015B2 (en) * | 2009-09-23 | 2012-03-27 | Microsoft Corporation | Power efficient object detection with selective polling |
US8261986B2 (en) | 2009-10-21 | 2012-09-11 | Kevin Kwong-Tai Chung | System and method for decoding an optically readable markable sheet and markable sheet therefor |
US8850899B2 (en) | 2010-04-15 | 2014-10-07 | Marathon Oil Company | Production logging processes and systems |
US8963720B2 (en) | 2010-05-11 | 2015-02-24 | The Boeing Company | RFID tag container |
US8659397B2 (en) | 2010-07-22 | 2014-02-25 | Vocollect, Inc. | Method and system for correctly identifying specific RFID tags |
US9162776B2 (en) | 2010-08-18 | 2015-10-20 | The Boeing Company | Aircraft safety and configuration monitoring system and method |
USD643400S1 (en) | 2010-08-19 | 2011-08-16 | Vocollect Healthcare Systems, Inc. | Body-worn mobile device |
USD643013S1 (en) | 2010-08-20 | 2011-08-09 | Vocollect Healthcare Systems, Inc. | Body-worn mobile device |
US9609281B2 (en) | 2010-09-29 | 2017-03-28 | International Business Machines Corporation | Validating asset movement using virtual tripwires and a RFID-enabled asset management system |
US8823554B2 (en) | 2010-12-09 | 2014-09-02 | The Boeing Company | Managing a plurality of radio frequency identification devices |
US8791823B2 (en) | 2011-06-03 | 2014-07-29 | The Boeing Company | Aircraft part control system |
WO2013170009A1 (en) | 2012-05-09 | 2013-11-14 | Applied Dna Sciences, Inc. | Verification of physical encryption taggants uning digital representatives and authentications thereof |
US9830424B2 (en) | 2013-09-18 | 2017-11-28 | Hill-Rom Services, Inc. | Bed/room/patient association systems and methods |
US9392411B1 (en) | 2014-04-08 | 2016-07-12 | Ahmed Khalifa Al-Yousif | Item and object location system |
US20170352256A1 (en) * | 2014-12-22 | 2017-12-07 | Technomirai Co., Ltd. | Digital find security system, method, and program |
US10289882B2 (en) * | 2016-06-23 | 2019-05-14 | Amadeus S.A.S. | Cargo handling system |
US10127747B2 (en) | 2016-12-22 | 2018-11-13 | Active8 Software, LLC | Systems and methods for electronic ticketing, monitoring, and indicating permissive use of facilities |
CN110520337B (en) | 2017-01-05 | 2022-08-30 | 复兴者迈科思公司 | Digital license plate system with anti-theft system |
JP7145159B2 (en) | 2017-01-05 | 2022-09-30 | リバイバーエムエックス,インク. | Power and communication modes for digital license plates |
EP3984828A1 (en) | 2017-01-05 | 2022-04-20 | Revivermx, Inc. | Thermal control system for a digital license plate |
KR101808589B1 (en) * | 2017-04-10 | 2017-12-13 | 한미아이티 주식회사 | System for managing items using tag information |
US11911325B2 (en) | 2019-02-26 | 2024-02-27 | Hill-Rom Services, Inc. | Bed interface for manual location |
CN114844531A (en) | 2019-04-11 | 2022-08-02 | 奈克赛特公司 | System for simultaneous tag triggering and sequential tag reading |
US11551537B2 (en) * | 2019-04-11 | 2023-01-10 | Nexite Ltd. | Wireless dual-mode identification tag |
EP4275160A1 (en) | 2021-01-11 | 2023-11-15 | Nexite Ltd. | Contactless and automatic operations of a retail store |
US20230186329A1 (en) | 2021-12-13 | 2023-06-15 | Nexite Ltd. | Systems and methods for estimating foot traffic |
Citations (91)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3679874A (en) * | 1970-07-06 | 1972-07-25 | Bendix Corp | Automatic baggage handling system |
US3689885A (en) * | 1970-09-15 | 1972-09-05 | Transitag Corp | Inductively coupled passive responder and interrogator unit having multidimension electromagnetic field capabilities |
US3832530A (en) * | 1972-01-04 | 1974-08-27 | Westinghouse Electric Corp | Object identifying apparatus |
US3986119A (en) * | 1973-12-28 | 1976-10-12 | International Business Machines Corporation | Emergency communication system |
US4075632A (en) * | 1974-08-27 | 1978-02-21 | The United States Of America As Represented By The United States Department Of Energy | Interrogation, and detection system |
US4354189A (en) * | 1977-11-09 | 1982-10-12 | Lemelson Jerome H | Switch and lock activating system and method |
US4684933A (en) * | 1986-05-15 | 1987-08-04 | Rita Ann Gray | Unauthorized personnel detection system |
US4750197A (en) * | 1986-11-10 | 1988-06-07 | Denekamp Mark L | Integrated cargo security system |
US4761778A (en) * | 1985-04-11 | 1988-08-02 | Massachusetts Institute Of Technology | Coder-packetizer for random accessing in digital communication with multiple accessing |
US4766299A (en) * | 1986-03-28 | 1988-08-23 | Spectra-Physics, Inc. | Hand-mounted bar code reader |
US4776464A (en) * | 1985-06-17 | 1988-10-11 | Bae Automated Systems, Inc. | Automated article handling system and process |
US4799059A (en) * | 1986-03-14 | 1989-01-17 | Enscan, Inc. | Automatic/remote RF instrument monitoring system |
US4811421A (en) * | 1986-03-14 | 1989-03-07 | Christophe Havel | Transmission power control device in a radio communication transmitting/receiving station |
US4837575A (en) * | 1985-11-04 | 1989-06-06 | Motorola, Inc. | Identification system |
US4845504A (en) * | 1987-04-08 | 1989-07-04 | M/A-Com, Inc. | Mobile radio network for nationwide communications |
US4850009A (en) * | 1986-05-12 | 1989-07-18 | Clinicom Incorporated | Portable handheld terminal including optical bar code reader and electromagnetic transceiver means for interactive wireless communication with a base communications station |
US4857893A (en) * | 1986-07-18 | 1989-08-15 | Bi Inc. | Single chip transponder device |
US4862160A (en) * | 1983-12-29 | 1989-08-29 | Revlon, Inc. | Item identification tag for rapid inventory data acquisition system |
US4955018A (en) * | 1987-11-10 | 1990-09-04 | Echelon Systems Corporation | Protocol for network having plurality of intelligent cells |
US4969146A (en) * | 1987-11-10 | 1990-11-06 | Echelon Systems Corporation | Protocol for network having a plurality of intelligent cells |
US4999636A (en) * | 1989-02-17 | 1991-03-12 | Amtech Technology Corporation | Range limiting system |
US5003619A (en) * | 1989-01-31 | 1991-03-26 | Motorola, Inc. | Method and apparatus for adjusting the power of a transmitter |
US5008661A (en) * | 1985-09-27 | 1991-04-16 | Raj Phani K | Electronic remote chemical identification system |
US5019813A (en) * | 1987-04-13 | 1991-05-28 | N.V. Nederlandsche Apparatenfabriek Nedap | System for the contactless exchange of data |
US5025486A (en) * | 1988-12-09 | 1991-06-18 | Dallas Semiconductor Corporation | Wireless communication system with parallel polling |
US5030807A (en) * | 1990-01-16 | 1991-07-09 | Amtech Corporation | System for reading and writing data from and into remote tags |
US5046066A (en) * | 1987-02-09 | 1991-09-03 | Telesystems Slw Inc. | Wireless local area network |
US5055968A (en) * | 1988-07-04 | 1991-10-08 | Sony Corporation | Thin electronic device having an integrated circuit chip and a power battery and a method for producing same |
US5055659A (en) * | 1990-02-06 | 1991-10-08 | Amtech Technology Corp. | High speed system for reading and writing data from and into remote tags |
US5121407A (en) * | 1990-09-27 | 1992-06-09 | Pittway Corporation | Spread spectrum communications system |
US5124697A (en) * | 1989-10-16 | 1992-06-23 | Motorola, Inc. | Acknowledge-back pager |
US5144313A (en) * | 1988-10-27 | 1992-09-01 | Steffen Kirknes | Method for processing transmitted and reflected signals for removing unwanted signals and noise from wanted signals |
US5144668A (en) * | 1991-01-25 | 1992-09-01 | Motorola, Inc. | Signal overlap detection in a communication system |
US5144314A (en) * | 1987-10-23 | 1992-09-01 | Allen-Bradley Company, Inc. | Programmable object identification transponder system |
US5150310A (en) * | 1989-08-30 | 1992-09-22 | Consolve, Inc. | Method and apparatus for position detection |
US5150114A (en) * | 1989-11-10 | 1992-09-22 | U.S. Philips Corporation | Polling-type information transmission system |
US5148618A (en) * | 1990-06-01 | 1992-09-22 | Brewster Blair M | Sealed tag |
US5164985A (en) * | 1987-10-27 | 1992-11-17 | Nysen Paul A | Passive universal communicator system |
US5168510A (en) * | 1984-03-06 | 1992-12-01 | Comsource Systems | Spread spectrum-time diversity communications systems and transceivers for multidrop area networks |
US5194860A (en) * | 1989-11-16 | 1993-03-16 | The General Electric Company, P.L.C. | Radio telemetry systems with channel selection |
US5214410A (en) * | 1989-07-10 | 1993-05-25 | Csir | Location of objects |
US5220678A (en) * | 1991-08-12 | 1993-06-15 | Motorola, Inc. | Method and apparatus for adjusting the power of a transmitter |
US5231646A (en) * | 1992-03-16 | 1993-07-27 | Kyros Corporation | Communications system |
US5245346A (en) * | 1989-12-28 | 1993-09-14 | Kabushiki Kaisha Toyota Chuo Kenyusho | Interrogator/transponder system and mobile transponder device |
US5272324A (en) * | 1990-08-10 | 1993-12-21 | Interlink Technologies, Inc. | Portable scanner system with transceiver for two-way radio frequency communication |
US5278992A (en) * | 1991-11-08 | 1994-01-11 | Teknekron Communications Systems, Inc. | Method and apparatus for controlling transmission power of a remote unit communicating with a base unit over a common frequency channel |
US5307463A (en) * | 1990-03-08 | 1994-04-26 | Allen-Bradley Company, Inc. | Programmable controller communication module |
US5313211A (en) * | 1990-08-13 | 1994-05-17 | Sharp Kabushiki Kaisha | Portable data processing device capable of transmitting processed data on a radio by reflection of unmodulated carrier signal externally applied |
US5326652A (en) * | 1993-01-25 | 1994-07-05 | Micron Semiconductor, Inc. | Battery package and method using flexible polymer films having a deposited layer of an inorganic material |
US5340968A (en) * | 1991-05-07 | 1994-08-23 | Nippondenso Company, Ltd. | Information storage medium with electronic and visual areas |
US5347274A (en) * | 1990-05-17 | 1994-09-13 | At/Comm Incorporated | Hazardous waste transport management system |
US5365551A (en) * | 1992-12-15 | 1994-11-15 | Micron Technology, Inc. | Data communication transceiver using identification protocol |
US5373503A (en) * | 1993-04-30 | 1994-12-13 | Information Technology, Inc. | Group randomly addressed polling method |
US5382784A (en) * | 1993-02-08 | 1995-01-17 | Indala Corporation | Hand-held dual technology identification tag reading head |
US5406263A (en) * | 1992-07-27 | 1995-04-11 | Micron Communications, Inc. | Anti-theft method for detecting the unauthorized opening of containers and baggage |
US5416310A (en) * | 1993-05-28 | 1995-05-16 | Symbol Technologies, Inc. | Computer and/or scanner system incorporated into a garment |
US5448110A (en) * | 1992-06-17 | 1995-09-05 | Micron Communications, Inc. | Enclosed transceiver |
US5497140A (en) * | 1992-08-12 | 1996-03-05 | Micron Technology, Inc. | Electrically powered postage stamp or mailing or shipping label operative with radio frequency (RF) communication |
US5500650A (en) * | 1992-12-15 | 1996-03-19 | Micron Technology, Inc. | Data communication method using identification protocol |
US5500651A (en) * | 1994-06-24 | 1996-03-19 | Texas Instruments Incorporated | System and method for reading multiple RF-ID transponders |
US5521600A (en) * | 1994-09-06 | 1996-05-28 | The Regents Of The University Of California | Range-gated field disturbance sensor with range-sensitivity compensation |
US5534847A (en) * | 1994-11-23 | 1996-07-09 | Mcgregor; Gerald C. | Bicycle alarm system |
US5560970A (en) * | 1993-07-16 | 1996-10-01 | Esselte Meto International Gmbh | Display marking tag, such as a display marking tag having an adhesive fastening strip |
USH1606H (en) * | 1994-07-22 | 1996-11-05 | The United States Of America As Represented By The Secretary Of The Army | Electronic quasi-passive identification system |
US5602535A (en) * | 1994-07-15 | 1997-02-11 | The Friedkin Corporation | Vehicle security system based on two step communication range between transmitter and receiver |
US5610387A (en) * | 1992-05-15 | 1997-03-11 | Symbol Technologies, Inc. | Portable optical scanning system worn by a user for reading indicia of differing light reflectivity |
US5613228A (en) * | 1992-07-06 | 1997-03-18 | Micron Technology, Inc. | Gain adjustment method in two-way communication systems |
US5627517A (en) * | 1995-11-01 | 1997-05-06 | Xerox Corporation | Decentralized tracking and routing system wherein packages are associated with active tags |
US5640002A (en) * | 1995-08-15 | 1997-06-17 | Ruppert; Jonathan Paul | Portable RF ID tag and barcode reader |
US5671362A (en) * | 1995-04-04 | 1997-09-23 | Cowe; Alan B. | Materials monitoring systems, materials management systems and related methods |
US5751227A (en) * | 1994-12-22 | 1998-05-12 | Nippondenso Co., Ltd. | Communication system for vehicles |
US5751256A (en) * | 1994-03-04 | 1998-05-12 | Flexcon Company Inc. | Resonant tag labels and method of making same |
US5785181A (en) * | 1995-11-02 | 1998-07-28 | Clothestrak, Inc. | Permanent RFID garment tracking system |
US5793305A (en) * | 1991-04-03 | 1998-08-11 | Turner; Leigh Holbrook | Article sorting system |
US5798693A (en) * | 1995-06-07 | 1998-08-25 | Engellenner; Thomas J. | Electronic locating systems |
US5828693A (en) * | 1996-03-21 | 1998-10-27 | Amtech Corporation | Spread spectrum frequency hopping reader system |
US5850187A (en) * | 1996-03-27 | 1998-12-15 | Amtech Corporation | Integrated electronic tag reader and wireless communication link |
US5855988A (en) * | 1995-11-27 | 1999-01-05 | Nippon Paint Co., Ltd. | Electromagnetic wave absorbing shielding material |
US5887176A (en) * | 1996-06-28 | 1999-03-23 | Randtec, Inc. | Method and system for remote monitoring and tracking of inventory |
US5920287A (en) * | 1997-01-21 | 1999-07-06 | Widata Corporation | Radio location system for precisely tracking objects by RF transceiver tags which randomly and repetitively emit wideband identification signals |
US5963927A (en) * | 1996-01-31 | 1999-10-05 | Neopost Limited | Mailing system |
US5971587A (en) * | 1997-08-01 | 1999-10-26 | Kato; Kiroku | Package and mail delivery system |
US6097301A (en) * | 1996-04-04 | 2000-08-01 | Micron Communications, Inc. | RF identification system with restricted range |
US6121544A (en) * | 1998-01-15 | 2000-09-19 | Petsinger; Julie Ann | Electromagnetic shield to prevent surreptitious access to contactless smartcards |
US6144301A (en) * | 1997-02-10 | 2000-11-07 | Safetrac Control Systems, Inc. | Electronic tracking tag |
US6538564B1 (en) * | 1997-01-17 | 2003-03-25 | Integrated Silicon Design Pty Ltd | Multiple tag reading system |
US20060187061A1 (en) * | 2005-02-07 | 2006-08-24 | Colby Steven M | Radio frequency shielding |
US7163152B2 (en) * | 2004-12-15 | 2007-01-16 | Osborn Warren R | Protective container for readable cards |
US7175084B2 (en) * | 2000-05-03 | 2007-02-13 | Axalto Sa | Integrated circuit card and case therefor |
US20070040653A1 (en) * | 2005-08-16 | 2007-02-22 | Potts Kevin L | Rfid shielding devices |
US7482925B2 (en) * | 2005-06-24 | 2009-01-27 | Visa U.S.A. | Apparatus and method to electromagnetically shield portable consumer devices |
Family Cites Families (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US5565858A (en) * | 1994-09-14 | 1996-10-15 | Northrop Grumman Corporation | Electronic inventory system for stacked containers |
US5742237A (en) * | 1995-11-30 | 1998-04-21 | Lockheed Martin Corporation | Tag location monitor |
US5842555A (en) * | 1996-12-16 | 1998-12-01 | Gannon; Donald N. | Automated baggage tracking system and method for use in a baggage conveyor system |
-
1996
- 1996-04-04 US US08/628,125 patent/US6097301A/en not_active Expired - Lifetime
-
2000
- 2000-08-01 US US09/631,060 patent/US6842121B1/en not_active Expired - Fee Related
-
2008
- 2008-01-18 US US12/016,900 patent/US20080117025A1/en not_active Abandoned
-
2012
- 2012-04-30 US US13/460,694 patent/US20120274450A1/en not_active Abandoned
Patent Citations (95)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3679874A (en) * | 1970-07-06 | 1972-07-25 | Bendix Corp | Automatic baggage handling system |
US3689885A (en) * | 1970-09-15 | 1972-09-05 | Transitag Corp | Inductively coupled passive responder and interrogator unit having multidimension electromagnetic field capabilities |
US3832530A (en) * | 1972-01-04 | 1974-08-27 | Westinghouse Electric Corp | Object identifying apparatus |
US3986119A (en) * | 1973-12-28 | 1976-10-12 | International Business Machines Corporation | Emergency communication system |
US4075632A (en) * | 1974-08-27 | 1978-02-21 | The United States Of America As Represented By The United States Department Of Energy | Interrogation, and detection system |
US4354189A (en) * | 1977-11-09 | 1982-10-12 | Lemelson Jerome H | Switch and lock activating system and method |
US4862160A (en) * | 1983-12-29 | 1989-08-29 | Revlon, Inc. | Item identification tag for rapid inventory data acquisition system |
US5168510A (en) * | 1984-03-06 | 1992-12-01 | Comsource Systems | Spread spectrum-time diversity communications systems and transceivers for multidrop area networks |
US4761778A (en) * | 1985-04-11 | 1988-08-02 | Massachusetts Institute Of Technology | Coder-packetizer for random accessing in digital communication with multiple accessing |
US4776464A (en) * | 1985-06-17 | 1988-10-11 | Bae Automated Systems, Inc. | Automated article handling system and process |
US5008661A (en) * | 1985-09-27 | 1991-04-16 | Raj Phani K | Electronic remote chemical identification system |
US4837575A (en) * | 1985-11-04 | 1989-06-06 | Motorola, Inc. | Identification system |
US4799059A (en) * | 1986-03-14 | 1989-01-17 | Enscan, Inc. | Automatic/remote RF instrument monitoring system |
US4811421A (en) * | 1986-03-14 | 1989-03-07 | Christophe Havel | Transmission power control device in a radio communication transmitting/receiving station |
US4766299A (en) * | 1986-03-28 | 1988-08-23 | Spectra-Physics, Inc. | Hand-mounted bar code reader |
US4850009A (en) * | 1986-05-12 | 1989-07-18 | Clinicom Incorporated | Portable handheld terminal including optical bar code reader and electromagnetic transceiver means for interactive wireless communication with a base communications station |
US4684933A (en) * | 1986-05-15 | 1987-08-04 | Rita Ann Gray | Unauthorized personnel detection system |
US4857893A (en) * | 1986-07-18 | 1989-08-15 | Bi Inc. | Single chip transponder device |
US4750197A (en) * | 1986-11-10 | 1988-06-07 | Denekamp Mark L | Integrated cargo security system |
US5046066A (en) * | 1987-02-09 | 1991-09-03 | Telesystems Slw Inc. | Wireless local area network |
US4845504A (en) * | 1987-04-08 | 1989-07-04 | M/A-Com, Inc. | Mobile radio network for nationwide communications |
US5019813A (en) * | 1987-04-13 | 1991-05-28 | N.V. Nederlandsche Apparatenfabriek Nedap | System for the contactless exchange of data |
US5144314A (en) * | 1987-10-23 | 1992-09-01 | Allen-Bradley Company, Inc. | Programmable object identification transponder system |
US5164985A (en) * | 1987-10-27 | 1992-11-17 | Nysen Paul A | Passive universal communicator system |
US4969146A (en) * | 1987-11-10 | 1990-11-06 | Echelon Systems Corporation | Protocol for network having a plurality of intelligent cells |
US4955018A (en) * | 1987-11-10 | 1990-09-04 | Echelon Systems Corporation | Protocol for network having plurality of intelligent cells |
US5055968A (en) * | 1988-07-04 | 1991-10-08 | Sony Corporation | Thin electronic device having an integrated circuit chip and a power battery and a method for producing same |
US5144313A (en) * | 1988-10-27 | 1992-09-01 | Steffen Kirknes | Method for processing transmitted and reflected signals for removing unwanted signals and noise from wanted signals |
US5025486A (en) * | 1988-12-09 | 1991-06-18 | Dallas Semiconductor Corporation | Wireless communication system with parallel polling |
US5003619A (en) * | 1989-01-31 | 1991-03-26 | Motorola, Inc. | Method and apparatus for adjusting the power of a transmitter |
US4999636A (en) * | 1989-02-17 | 1991-03-12 | Amtech Technology Corporation | Range limiting system |
US5214410A (en) * | 1989-07-10 | 1993-05-25 | Csir | Location of objects |
US5150310A (en) * | 1989-08-30 | 1992-09-22 | Consolve, Inc. | Method and apparatus for position detection |
US5124697A (en) * | 1989-10-16 | 1992-06-23 | Motorola, Inc. | Acknowledge-back pager |
US5150114A (en) * | 1989-11-10 | 1992-09-22 | U.S. Philips Corporation | Polling-type information transmission system |
US5194860A (en) * | 1989-11-16 | 1993-03-16 | The General Electric Company, P.L.C. | Radio telemetry systems with channel selection |
US5245346A (en) * | 1989-12-28 | 1993-09-14 | Kabushiki Kaisha Toyota Chuo Kenyusho | Interrogator/transponder system and mobile transponder device |
US5030807A (en) * | 1990-01-16 | 1991-07-09 | Amtech Corporation | System for reading and writing data from and into remote tags |
US5055659A (en) * | 1990-02-06 | 1991-10-08 | Amtech Technology Corp. | High speed system for reading and writing data from and into remote tags |
US5307463A (en) * | 1990-03-08 | 1994-04-26 | Allen-Bradley Company, Inc. | Programmable controller communication module |
US5347274A (en) * | 1990-05-17 | 1994-09-13 | At/Comm Incorporated | Hazardous waste transport management system |
US5148618A (en) * | 1990-06-01 | 1992-09-22 | Brewster Blair M | Sealed tag |
US5272324A (en) * | 1990-08-10 | 1993-12-21 | Interlink Technologies, Inc. | Portable scanner system with transceiver for two-way radio frequency communication |
US5313211A (en) * | 1990-08-13 | 1994-05-17 | Sharp Kabushiki Kaisha | Portable data processing device capable of transmitting processed data on a radio by reflection of unmodulated carrier signal externally applied |
US5121407A (en) * | 1990-09-27 | 1992-06-09 | Pittway Corporation | Spread spectrum communications system |
US5144668A (en) * | 1991-01-25 | 1992-09-01 | Motorola, Inc. | Signal overlap detection in a communication system |
US5793305A (en) * | 1991-04-03 | 1998-08-11 | Turner; Leigh Holbrook | Article sorting system |
US5340968A (en) * | 1991-05-07 | 1994-08-23 | Nippondenso Company, Ltd. | Information storage medium with electronic and visual areas |
US5220678A (en) * | 1991-08-12 | 1993-06-15 | Motorola, Inc. | Method and apparatus for adjusting the power of a transmitter |
US5278992A (en) * | 1991-11-08 | 1994-01-11 | Teknekron Communications Systems, Inc. | Method and apparatus for controlling transmission power of a remote unit communicating with a base unit over a common frequency channel |
US5231646A (en) * | 1992-03-16 | 1993-07-27 | Kyros Corporation | Communications system |
US5610387A (en) * | 1992-05-15 | 1997-03-11 | Symbol Technologies, Inc. | Portable optical scanning system worn by a user for reading indicia of differing light reflectivity |
US5448110A (en) * | 1992-06-17 | 1995-09-05 | Micron Communications, Inc. | Enclosed transceiver |
US5613228A (en) * | 1992-07-06 | 1997-03-18 | Micron Technology, Inc. | Gain adjustment method in two-way communication systems |
US5406263A (en) * | 1992-07-27 | 1995-04-11 | Micron Communications, Inc. | Anti-theft method for detecting the unauthorized opening of containers and baggage |
US5497140A (en) * | 1992-08-12 | 1996-03-05 | Micron Technology, Inc. | Electrically powered postage stamp or mailing or shipping label operative with radio frequency (RF) communication |
US5627544A (en) * | 1992-12-15 | 1997-05-06 | Micron Technology, Inc. | Data communication method using identification protocol |
US5583850A (en) * | 1992-12-15 | 1996-12-10 | Micron Technology, Inc. | Data communication system using identification protocol |
US5500650A (en) * | 1992-12-15 | 1996-03-19 | Micron Technology, Inc. | Data communication method using identification protocol |
US5841770A (en) * | 1992-12-15 | 1998-11-24 | Micron Technology, Inc. | Data communication system using indentification protocol |
US5365551A (en) * | 1992-12-15 | 1994-11-15 | Micron Technology, Inc. | Data communication transceiver using identification protocol |
US5326652A (en) * | 1993-01-25 | 1994-07-05 | Micron Semiconductor, Inc. | Battery package and method using flexible polymer films having a deposited layer of an inorganic material |
US5382784A (en) * | 1993-02-08 | 1995-01-17 | Indala Corporation | Hand-held dual technology identification tag reading head |
US5373503A (en) * | 1993-04-30 | 1994-12-13 | Information Technology, Inc. | Group randomly addressed polling method |
US5416310A (en) * | 1993-05-28 | 1995-05-16 | Symbol Technologies, Inc. | Computer and/or scanner system incorporated into a garment |
US5560970A (en) * | 1993-07-16 | 1996-10-01 | Esselte Meto International Gmbh | Display marking tag, such as a display marking tag having an adhesive fastening strip |
US5751256A (en) * | 1994-03-04 | 1998-05-12 | Flexcon Company Inc. | Resonant tag labels and method of making same |
US5500651A (en) * | 1994-06-24 | 1996-03-19 | Texas Instruments Incorporated | System and method for reading multiple RF-ID transponders |
US5602535A (en) * | 1994-07-15 | 1997-02-11 | The Friedkin Corporation | Vehicle security system based on two step communication range between transmitter and receiver |
USH1606H (en) * | 1994-07-22 | 1996-11-05 | The United States Of America As Represented By The Secretary Of The Army | Electronic quasi-passive identification system |
US5521600A (en) * | 1994-09-06 | 1996-05-28 | The Regents Of The University Of California | Range-gated field disturbance sensor with range-sensitivity compensation |
US5534847A (en) * | 1994-11-23 | 1996-07-09 | Mcgregor; Gerald C. | Bicycle alarm system |
US5751227A (en) * | 1994-12-22 | 1998-05-12 | Nippondenso Co., Ltd. | Communication system for vehicles |
US5671362A (en) * | 1995-04-04 | 1997-09-23 | Cowe; Alan B. | Materials monitoring systems, materials management systems and related methods |
US5798693A (en) * | 1995-06-07 | 1998-08-25 | Engellenner; Thomas J. | Electronic locating systems |
US5640002A (en) * | 1995-08-15 | 1997-06-17 | Ruppert; Jonathan Paul | Portable RF ID tag and barcode reader |
US5627517A (en) * | 1995-11-01 | 1997-05-06 | Xerox Corporation | Decentralized tracking and routing system wherein packages are associated with active tags |
US5785181A (en) * | 1995-11-02 | 1998-07-28 | Clothestrak, Inc. | Permanent RFID garment tracking system |
US5855988A (en) * | 1995-11-27 | 1999-01-05 | Nippon Paint Co., Ltd. | Electromagnetic wave absorbing shielding material |
US5963927A (en) * | 1996-01-31 | 1999-10-05 | Neopost Limited | Mailing system |
US5828693A (en) * | 1996-03-21 | 1998-10-27 | Amtech Corporation | Spread spectrum frequency hopping reader system |
US5850187A (en) * | 1996-03-27 | 1998-12-15 | Amtech Corporation | Integrated electronic tag reader and wireless communication link |
US6097301A (en) * | 1996-04-04 | 2000-08-01 | Micron Communications, Inc. | RF identification system with restricted range |
US6842121B1 (en) * | 1996-04-04 | 2005-01-11 | Micron Technology, Inc. | RF identification system for determining whether object has reached destination |
US5887176A (en) * | 1996-06-28 | 1999-03-23 | Randtec, Inc. | Method and system for remote monitoring and tracking of inventory |
US6538564B1 (en) * | 1997-01-17 | 2003-03-25 | Integrated Silicon Design Pty Ltd | Multiple tag reading system |
US5920287A (en) * | 1997-01-21 | 1999-07-06 | Widata Corporation | Radio location system for precisely tracking objects by RF transceiver tags which randomly and repetitively emit wideband identification signals |
US6144301A (en) * | 1997-02-10 | 2000-11-07 | Safetrac Control Systems, Inc. | Electronic tracking tag |
US5971587A (en) * | 1997-08-01 | 1999-10-26 | Kato; Kiroku | Package and mail delivery system |
US6121544A (en) * | 1998-01-15 | 2000-09-19 | Petsinger; Julie Ann | Electromagnetic shield to prevent surreptitious access to contactless smartcards |
US7175084B2 (en) * | 2000-05-03 | 2007-02-13 | Axalto Sa | Integrated circuit card and case therefor |
US7163152B2 (en) * | 2004-12-15 | 2007-01-16 | Osborn Warren R | Protective container for readable cards |
US20060187061A1 (en) * | 2005-02-07 | 2006-08-24 | Colby Steven M | Radio frequency shielding |
US7482925B2 (en) * | 2005-06-24 | 2009-01-27 | Visa U.S.A. | Apparatus and method to electromagnetically shield portable consumer devices |
US20070040653A1 (en) * | 2005-08-16 | 2007-02-22 | Potts Kevin L | Rfid shielding devices |
Cited By (26)
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---|---|---|---|---|
US7639141B2 (en) | 1998-03-27 | 2009-12-29 | Keystone Technology Solutions, Llc | Systems and methods for identifying lost or stolen devices |
US20080024303A1 (en) * | 1998-03-27 | 2008-01-31 | Micron Technology, Inc. | Systems and methods for identifying missing items |
US20070252697A1 (en) * | 1998-03-27 | 2007-11-01 | Micron Technology, Inc. | Method and system for identifying missing items |
US20080012711A1 (en) * | 1998-03-27 | 2008-01-17 | Micron Technology, Inc. | Systems and methods for identifying lost or stolen devices |
US7982608B2 (en) * | 1998-03-27 | 2011-07-19 | Round Rock Research, Llc | Method and system for identifying missing items |
US8395506B2 (en) * | 1998-03-27 | 2013-03-12 | Round Rock Research, Llc | Method and system for identifying missing items |
US20130257618A1 (en) * | 1998-03-27 | 2013-10-03 | Round Rock Research, Llc | Methods and system for identifying lost or stolen RFID devices |
US7755490B2 (en) | 1998-03-27 | 2010-07-13 | Round Rock Research, Llc | Systems and methods for identifying missing items |
US8269605B2 (en) | 1999-08-09 | 2012-09-18 | Round Rock Research, Llc | RFID material tracking method and apparatus |
US7808367B2 (en) | 1999-08-09 | 2010-10-05 | Round Rock Research, Llc | RFID material tracking method and apparatus |
US8378789B2 (en) | 1999-08-09 | 2013-02-19 | Round Rock Research, Llc | RFID material tracking method and apparatus |
US8125316B2 (en) | 1999-08-09 | 2012-02-28 | Round Rock Research, Llc | RFID material tracking method and apparatus |
US20090210517A1 (en) * | 2002-05-30 | 2009-08-20 | Sony Corporation | Information management device and method, information processing device and method recording medium, and program |
US7671721B2 (en) * | 2003-05-12 | 2010-03-02 | Valtion Teknillinen Tutkimuskesus | Remote sensor, device and method for activating selected remote sensor components |
US20060202802A1 (en) * | 2003-05-12 | 2006-09-14 | Seppae Heikki | Remote sensor, device and method for activating selected remote sensor components |
US8289164B2 (en) | 2003-12-12 | 2012-10-16 | Semiconductor Energy Laboratory Co., Ltd. | Semiconductor device and manufacturing method thereof |
US7546137B2 (en) * | 2005-02-28 | 2009-06-09 | Sirit Technologies Inc. | Power control loop and LO generation method |
US20070066223A1 (en) * | 2005-02-28 | 2007-03-22 | Sirit, Inc. | Power control loop and LO generation method |
US8000674B2 (en) * | 2007-07-31 | 2011-08-16 | Intel Corporation | Canceling self-jammer and interfering signals in an RFID system |
US20090036082A1 (en) * | 2007-07-31 | 2009-02-05 | Mohammed Sajid | Canceling self-jammer and interfering signals in an rfid system |
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US9171448B1 (en) * | 2014-06-11 | 2015-10-27 | Target Brands, Inc. | RFID tags for locating products |
US20180204030A1 (en) * | 2017-01-13 | 2018-07-19 | International Business Machines Corporation | Baggage handling |
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Also Published As
Publication number | Publication date |
---|---|
US6842121B1 (en) | 2005-01-11 |
US20120274450A1 (en) | 2012-11-01 |
US6097301A (en) | 2000-08-01 |
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