CA1286810C - Loudspeaker apparatus and method for a radio telephone apparatus - Google Patents
Loudspeaker apparatus and method for a radio telephone apparatusInfo
- Publication number
- CA1286810C CA1286810C CA000562243A CA562243A CA1286810C CA 1286810 C CA1286810 C CA 1286810C CA 000562243 A CA000562243 A CA 000562243A CA 562243 A CA562243 A CA 562243A CA 1286810 C CA1286810 C CA 1286810C
- Authority
- CA
- Canada
- Prior art keywords
- loudspeaker
- base unit
- radio telephone
- signal
- telephone set
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Lifetime
Links
- 238000000034 method Methods 0.000 title claims abstract description 15
- 108091006146 Channels Proteins 0.000 description 62
- 238000004891 communication Methods 0.000 description 13
- 230000006854 communication Effects 0.000 description 13
- 230000000875 corresponding effect Effects 0.000 description 5
- 239000000306 component Substances 0.000 description 4
- 230000000994 depressogenic effect Effects 0.000 description 4
- 230000005236 sound signal Effects 0.000 description 4
- 238000010586 diagram Methods 0.000 description 3
- 230000001702 transmitter Effects 0.000 description 3
- 230000005611 electricity Effects 0.000 description 2
- 238000012986 modification Methods 0.000 description 2
- 230000004048 modification Effects 0.000 description 2
- KEIFWROAQVVDBN-UHFFFAOYSA-N 1,2-dihydronaphthalene Chemical group C1=CC=C2C=CCCC2=C1 KEIFWROAQVVDBN-UHFFFAOYSA-N 0.000 description 1
- 241001527902 Aratus Species 0.000 description 1
- GRJMIMFTPGNXIC-UHFFFAOYSA-N Dialin Natural products C1=C(OC)C(OC)=CC=C1C1C2=CC(OC)=C(OC)C=C2C=C(C)C1C GRJMIMFTPGNXIC-UHFFFAOYSA-N 0.000 description 1
- 241001415395 Spea Species 0.000 description 1
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- 230000007423 decrease Effects 0.000 description 1
- 230000009977 dual effect Effects 0.000 description 1
- 230000008520 organization Effects 0.000 description 1
Classifications
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04M—TELEPHONIC COMMUNICATION
- H04M1/00—Substation equipment, e.g. for use by subscribers
- H04M1/60—Substation equipment, e.g. for use by subscribers including speech amplifiers
- H04M1/6033—Substation equipment, e.g. for use by subscribers including speech amplifiers for providing handsfree use or a loudspeaker mode in telephone sets
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04M—TELEPHONIC COMMUNICATION
- H04M1/00—Substation equipment, e.g. for use by subscribers
- H04M1/60—Substation equipment, e.g. for use by subscribers including speech amplifiers
- H04M1/6033—Substation equipment, e.g. for use by subscribers including speech amplifiers for providing handsfree use or a loudspeaker mode in telephone sets
- H04M1/6041—Portable telephones adapted for handsfree use
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04M—TELEPHONIC COMMUNICATION
- H04M1/00—Substation equipment, e.g. for use by subscribers
- H04M1/72—Mobile telephones; Cordless telephones, i.e. devices for establishing wireless links to base stations without route selection
- H04M1/725—Cordless telephones
- H04M1/72502—Cordless telephones with one base station connected to a single line
Abstract
LOUDSPEAKER APPARATUS AND METHOD
FOR A RADIO TELEPHONE APPARATUS
ABSTRACT OF THE DISCLOSURE
A loudspeaker apparatus is used for a radio telephone appara-tus having a base unit and a radio telephone set. The base unit includes a loudspeaker for generating a speech signal from a wired telephone line coupled to the base unit. The loudspeaker is con-nected to the wired telephone line in response to a calling origina-tion signal by an operation of calling origination key if the radio telephone set is installed in the base unit.
FOR A RADIO TELEPHONE APPARATUS
ABSTRACT OF THE DISCLOSURE
A loudspeaker apparatus is used for a radio telephone appara-tus having a base unit and a radio telephone set. The base unit includes a loudspeaker for generating a speech signal from a wired telephone line coupled to the base unit. The loudspeaker is con-nected to the wired telephone line in response to a calling origina-tion signal by an operation of calling origination key if the radio telephone set is installed in the base unit.
Description
68~1~
LOUDSPEAKER APPARATUS AND METHOD
FOR A RADIO TELEPHONE APPARATUS
. Field of Invention This invention relates to the field of radio telephones typi-cally cordless telephones and, more particularly, to an apparatus and method for enabling sounds to be heard from another telephone apparatus by means of 2 loudspeaker.
LOUDSPEAKER APPARATUS AND METHOD
FOR A RADIO TELEPHONE APPARATUS
. Field of Invention This invention relates to the field of radio telephones typi-cally cordless telephones and, more particularly, to an apparatus and method for enabling sounds to be heard from another telephone apparatus by means of 2 loudspeaker.
2. Description of the Prior Art As is well known in the art, radio telephones, typica~ly cord-less telephones are comprised of a radio telephone set having handset and a base unit connected to a wired telephone line îor exchanging speech signals between the wired telephone line and the radio telephone set through a radio channel. The base unit and the radio telephone set are each provided with a pair of corresponding ~ransmitters and receivers.
When a call signal arrives at the wired telephone line, the base unit transmits a paging signal to the radio telephone set through a predetermined control channel to ~orm a speech channel.
The paging signal includes a channel signal indicating one of a plurality of speech channels. Then, the radio telephone set starts an operation to send out a paging response signal through the control channel in response to the received paging signal. The base unit detects the intensity of the received paging response signal sent out from the radio telephone set, I.e., the intensity of the paging response signal at the control channel. Then, the base unit stops the transmlssion of the paging signal when the detected intensity exceeds a predetermined level and switches the radio channel between the base unit and the radio telephone set from the control channel to the speech channel indicated in the paging signal. The radio telephone set also switches the radio channel from the control channel to the speech channel by the received paging signal. There-after, the base unit transmits a ringing signal to the radio telephone set via the speech channel. After transmitting the ringing signal, the base unit establishes a speech path between the wired telephone line and the radio telephone set when it receives an ~'of~-hook" signal from the radio telephone set indicating that the handset is ~'off the hook~'.
When the base unit is in a waiting state and receives a call origination signal (an off-hook signal) from the radio telephone set through the control channel, it determines the call origination request from the radio telephone set and transmits a response signal which includes the channel signal indicating one of the plurality of speech channels. Then, the base unit establishes a speech path between the wired telephone line and itself, and switches the radio channel from the control channel to the speech channel indicated in the response signal. After receiving the response signal, the radio telephone set also switches the radio channel from the control 1~3681~) channel to the speech channel in response to the recelved response signal.
If, in this state, the radio telephone set transmlts dialing sig-nals to the base unit through the speech channel by a dialing opera-5 tion, the dialing signal is transmitted ~o the wired telephone line viathe base unit.
Thus, the radio telephone apparatus carries out the operatlons o~ receiving incoming telephone calls rrom the wired telephone line and originating calls f rom the radio telephone set.
However, the prior art radio telephones sufrer a serious draw-back in that a sufflciently large enough loudspeaker can not be adapted to be used in the apparatus because it is necessary for the radio telephone set to be compact and light. Even ii a loudspeaker w~th a large enough speaker was adapted to be used in the apparatus, 15 lt is extremely difficult to drive ~he loudspeaker to generate speech signals because the capacity of the power source ol the radio tele-phone set ~s not sufflcient to drive the loudspeaker. Generally, the power soùrce is a small storage battery used to drlve the components o~ the radio telephone set. These components typically have low 2 0 power requ~ements. Loudspeakers typically have high power requirements.
SU~MARY OY THE INVENTION
It is, ~f~re, an cb~t o an aspect c~ ~e ~t i~
p~3e a la~OE a~aratus ~rl ne~d fi~r Ee in a r~3io ~le~
2 5 apparatus, which apparatus and method is capable of producing speech signals from another telephone apparatus with a loudspeaker.
It is a~ ~:t c~ an aspect aE ~e E~esent i~ti~ to ~ a apparatus capable of producing speech signals from another tel~
phone apparatus with a loudspeaker, which apparatus is used in a ~ ~6sln radio telephone apparatus and adapted to be made compact and light.
aforestated drawbacks, there is pro~ided a loudspeaker apparatus ~or 5 use in a radio telephone apparatus having a base unit and a radio telephone set so that sound signals may be heard from a loudspeaker in the base unit. The base unit Is coupled to a wired telephone line and connected to the radio telephone set through a radlo channel.
The base unit a~o operates by DC power converted from an AC
10 source. The radlo telephone set is powered by a small storage battery which may be charged by the DC power when the set is installed in or on the base unit. The radio telephone set also includes call origination keys, dialing keys, a microphone and speaker. ~he base unit includes a loudspeaker tor generating sound signals ~rom 15 said wired telephone line and a control clrcuit. The control circuit determines the loudspeaker mode in response to the call origination signal by the operation oI the call origination key ii' the radio tele-phone set is installed in the base unit. The loudspeaker mode is characterized by sound signals being reproduced through at least the 20 loudspeaker o~ the base unit. The control circuit connects the loud-spea~ser to the wired telephone line i~ that loudspeaker mode is determined, so that the sound signals may be heard through the loudspeaker.
- 4a-Various aspects of the invention are as follows:
A loudspeaker apparatus for a radio telephone appara-tus having a base unit coupled to a wired telephone line and a radio telephone set includlng a battery, wherein said radio telephone set is connected to said base unit through a radio channel, said loudspeaker apparatus comprising:
call origination means for generating a call origination signal;
loudspeaker means provided in said base unit for gener-ating a speech signal from said wired telephone line;
mode means provided in said base unit ~or determining at least one loudspeaker mode representing a speech operation with said loudspeaker means; and speech control means provided in said base unit ~or connecting said loudspeaker means to said wired telephone line in response to the call origination signal from said call origination means if the loudspeaker mode Is determined by said mode means.
In a radio telephone apparatus havin~ a base unit cou-pled to a wired telephone line and a radio telephone set lncluding a battery, said radio telephone set being connected to said unit through a radlo channel, a method for implementing loudspeaker mode selection comprising the steps oi:
a) generating a call origination signal;
b) determining a loudspeaker mode representing a speech operation with at least loudspeaker means provided in said base unit; and c) connecting said loudspeaker means to said wired telephone llne in response to the call origination signal if the loud-speaker mode is determined.
~ ~3681~
-4b-A radio telephone apparatus having a base unit coupled to a wired telephone line and a radio telephone set coupled to said base unit through a radio channel, whereln said base unit operates by an AC power source, and said radio telephone set operates by a bat-5 tery, said loudspeaker apparatus comprising:
call origination means tor generating a call originationsignal;
loudspeaker means, powered by said AC power source, ror generating a speech signal from said wired telephone line;
mode means provided in sald base unit rOr determininz a loudspeal~er mode representing a speech operation with at least said loudspeaker means; and speech control means provided in said base unit for connecting said loudspeaker means to said wired tel~
phone line in response to the call origination signal from said call 15 origination means it the loudspeaker mode is determined by said mode means.
BRIEF DESCRIPTION OY THE DRAWINGS
The sub~ect matter which is regarded as the invention is par-ticularly pointed out and distinctly claimed in the claims of the 20 specificatlon. The invention, however, both as to organization and method o~ practice, together with further obiects and advantages thereof, may be best understood by reference to the following ~ ~r~6~31~
detailed description of the invention taken in conjunction with the drawings in which:
Figure 1 shows a first embodiment of the present invention in block diagram form;
Figure 2 is an external view of a radio telephone apparatus of Figure l;
Figure 3 shows a flow chart of a radio telephone apparatus o~
Figure 1;
Figure 4 shows a second embodiment oI the present invention in block diagram form;
Figure 5 shows a flow chart of a radio telephone apparatus of Figure 4;
Figure 6 shows a third embodiment of the present invention in block diagram form;
Figure 7 is an external view of a radio telephone apparatus of Figure 6; and Figures 8 to ten show flow charts of a radio telephone appara-tus of Figure 6.
DETAILED DESCRIPTION
In the embodiment shown in Figure 1, base unit I is connected to a radio telephone set 2 through one ol a plurality ol radio chan-nels including a control channel (C-CH) and a plurality of speech channels (S-CHs), and is also connected to a wired telephone line 3.
Base unit 1 includes AC/DC converter 25 and AC plug 24, in order to produce a DC voltage tVcc) from a commercial power source (AC
power source). The DC voltage is supplied to the electrical compo-nents of base unit 1. Thus, base unit 1 is operated by the converted DC voltage. Radio telephone set 2 includes small storage bat~ery 29 adapted to charge the DC voltage and supply the charged DC voltage ~ ~6~
to electrical components of itseU. Both side terminals of battery 29 are connected to charging terminals 28. When radio telephone set 2 is installed in base unit 1, as shown in Figure 2, charging terminals 28 are connected to supplying terminals 27 of base unit 1. Since one of terminals 27 is connected to AC/DC converter 25 through resistor 26 and another terminal 27 is connected to ground, the converted DC voltage is supplied to battery 29 through resistor 26 and termi-nals 27 and 28. Resistor 26 is a current limiting resistor to limit the current supplied to terminal 27.
A signal sent from wired telephone line 3 is applied to hybrid clrcuit 4 via line relay 33 when line relay 33 is closed (ON~tate).
Hybrid circuit 4 sends the applied signal to switches 34 and 35.
Since switches 34 and 35 are always in a different switching state than each other, the signal from hybrid circuit 4 is supplied to trans-mitter S when switch 34 is closed or to loudspeaker 38 via ampli~ier 37 when switch 35 is clo~ed. Transmitter S modulates a carrier wave according to the supplied signal and transmits the modulated signal to radlo telephone set 2 via transmitting antenna 6. The car rier wave is supplied from synthesizer 9 and has frequency corre-sponding to radio channel selected in a known manner by synthesizer 9.
A signal transmi~ted from radio telephone set 2 Is received by receiving antenna 7 and demodulated by receiver 8 according to the carrier wave supplied from synthesizer 9. The demodulated signal is sent to hybrid circuit 4 when switch 36 is closed and then sent to wired telephone line 3 when line relay 33 is closed. The demodulated signal is also supplied to received field detector 10 and identification signal detector 11. Detector 10 is comprised of a carrier squelch circuit or a noise squelch circuit, and detects the intensity of the ~ ~r36~
received field, whils detector 11 determines whether the identifica-tion signal contained in the demodulated signal corresponds to a spe-cific identification signal allocated to radio telephone set 2. The detected signals frorn detectors 10 and 11 are supplied to control circuit 12. The demodulated signal from receiver 8 is also supplied to control circuit 12 to record a control signal contained in the demodulated signal and adapted to establish a speech path.
The call signal detector 30 detects a call signal (16 Hz signal) sent from wired telephone line 3, and informs control circuit 12 that the call signal has been received.
Control circuit 12 includes a microcomputer, a RAM for sto~
ing data and a ROM containing a stored operations program. Control circuit 12 controls transmitter 5, synthesizer 9, line relay 33, switches 34, 35 and 36 (to establish a speech path in response to the output signals of receiver 8), and detectors 10, 11 and 30. Control circuit 12 also is connected to a connection point between resistor 26 and supplying terminal 2?, and detects ~he voltage a at the con-nection point. The voltage a decreases when ràdio telephone set 2 is installed in ~æe unit 1 because the charging current is supplied to battery 29 through terminals 27 and 28. Control circuit 12 deter-mines that radio telephone set 2 is installed in base unit 1 if the voltage a is within a predetermined range and that radio telephone set 2 is not installed in the base unit 1 if the voltage is not within the predetermined range.
In radio telephone set 2, a signal transmitted from base unit l is received by receiving antenna 13, demodulated by receiver 14 and then applied to speaker 15. In the same manner as in base unit 1, the signal demodulated by receiver 14 is supplied to received signal detector 20, identification signal detector 21 and control circuit 22.
~ ~36~ 0 A voice slgnal inputted into microphone 16 is supplied to the trans-mitter 17 as a modulation input and then transmitted to base unit 1 through transmitting antenna 18. Control circuit 22 includes a microcomputer, a RAM for storing data and a ROM containing a stored operations program. Control circuit 22 controls receiver 14, transmitter 17 and synthesizer 19 (to establish a speech path in response to the output signals of receiver 14), and detectors 2û and 21. Control circuit 22 also causes speaker 23 to produce a ringing sound when i~ determines that a ringing signal is received accordlng to the demodulated signal from receiver 14. Speakers 15, 23 and mlcrophone 16 are adapted to consume very little electricity. Con-trol circuit 22 controls call origination operation in response to key data from calling origination key 31 and dialing key 32. Keys 31 and 32 are arranged on a top surface of radlo telephone set 2, as shown in Figure 2, so æ to be able to operate when radio telephone set 2 is installed in base unit 1. Key 31 is a slide type key and key 32 is a push-type key.
The operation of this embodiment is described wlth reference to the flow chart shown in Figure 3 æ follows.
In a waitlng state, control circuit 12 causes transmitter 5 to turn off and control circ~it 22 causes transmitter 17 to turn of ~, in order to prevent any unnecessary radio waves from radiating. Con-trol circuit 22 further causes receiver 14 to turn on and off periodi-cally to consume a minimal amount of electricity while in the wait-ing state. Also, in the waiting state, switches 34 and 36 are in the ON~tate (closed) and switch 35 is in the OFF-state (opened).
When call origination key 31 is slid to be in the ON-state, the key data is supplied to control circuit 22. Control circuit 22 deter-mines that a request to originate a call has been made in response to ~ ~6~
the supplied key data, step 201, and causes transmitter 17 to turn on, step 202. Control circuit 22 then sends a call origination signal to transmitter 17 to modulate and transmit the call origination signal, step 203. In this state, synthesizer 19 supplies a carrier wave, cor-responding to a control channel, to transmitter 17. A~ter transmit-ting the call origination signal, control circuit 22 causes receiver 14 to turn on continuously.
The transmitted call origination signal is received and demodulated by receiver 8. The demodulated signal is supplied to control circuit 12. When it is determined that the demodulated sig-nal is a call origination signal, step 101, control circuit 12 causes transmitter 5 to turn on, step 102. Control circuit 12 then sequen-tially switches the receiving channel to one of the plural~ty of speech channels to find a vacant speech channel. I~ control circuit 12 finds a vacant speech channel, it sends a response signal to trans-mitter 5 to modulate and transmit the response signal through the control channel, step 103. The response signal includes a speech channel signal indicating the vacant speech channel and a predeter-mined identification signal. Control circuit 12 then determines whether radio telephone set 2 is installed in base unit 1 according to the level oI voltage a, step 104. If not, control circuit 12 determines a normal mode and sends a control signal to line relay 33 to connect wired telephone line 3 to hybrid circuit 4, step 105. Control circuit 12 sends a control signal to synthesizer 9 to switch the control chan-nel to the selected vacant speech channel, step 106.
When receiver 14 receives the transmitted response signal, receiver 14 demodulates the signal and sends the demodulated signal to control circuit 22. When control circuit 22 determines the demodulated signal is the response signal, step 204, it sends a control 8~
signal to synthesizer 9 to switch the control channel to the indicated speech channel according to the speech channel signal in the response signal, step 205. In making this determination, control circuit 22 compares the identification signal in the response signal to its identification data. If control circuit 22 determines the identi-fication signal doesn't correspond to its identiIication data, it doesn~t respond to the demodulated signal. If the corresponding response signal is not received for a predetermined period, step 205, control circuit 22 annuls the received request for call origination and causes transmitter 17 to turn off, step 212. Control circuit 22 also causes receiver 14 to turn on and off periodlcally. Therefore, radio tele-phone set 2 is again in the waiting state.
When the speech channel between base unit 1 and radio tele-phone set 2 is established, a dial tone from wired telephone line 3 is transmitted to radio telephone set 2 and is generated by spea}cer 15.
The dialing key 32 is depressed to transmit a dialing signal to base unit 1 after the dial tone is heard through speaker 15. Control cir-cuit 22 receives the dialing key data from dialing key 32 and pro-vides the data to transmitter 17, steps 207 and 208. Transmitter 17 modulates and transmits the dialing signal through the speech chan-nel in response to the received data. When the dialing signal is received by ~eceiver 8, receiver 8 demodulates ~he dialing signal and provides the demodulated dialing signal to control circuit 12. Con-trol circuit 12 sends a dialing signal, such as a DTMF (dual tone multi-frequency) signal or a DP (dial pulse) signal, to wired tele-phone line 3, in response to the demodulated dialing signal, steps 107 and 108. Thus, the call origination operation is carried out and the radio telephone apparatus is placed in a communication state.
~ ~36~
Thereafter, when call origination key 31 is slid to be in its initial position, control circuit 22 determines the end oî speech and sends an end slgnal to transmitter 17 to transmit the end signal to base unit 1, steps 209 and 210. Control circuit 22 then sends a con-trol signal to synthesizer 19 to switch the speech channel to the control channel, step 211, and causes transmitter 17 to turn off, step 212. Control circuit 22 also causes receiver 14 to turn on and off periodically. Therefore, radio telephone set 2 is in the waiting state again.
When the end signal is received by receiver 8, receiver 8 demodulates the end signal and sends the end signal to control cir-cuit 12. Control circuit 12 sends a control signal to synthesizer 9 to switch the speech channel to the control channel in response to the received and demodulated end signal, steps 109 and 110. Control circuit 12 then sends control signals to line relay 33 and transmitter 5 to disconnect wired telephone line 3 ~rom hybrid circuit 4 and turn off transmitter 5, steps 111 and 112. Therefore, bæe unit 1 is also in the waiting state again.
~ control circuit 12 determines radio telephone set 2 is installed in base unit I at step 104, it determines a loudspeaker mode and sends a control signal to line relay 33 to connect wired tele-phone llne 3 to hybrid circuit 4, step 113. Control circuit 12 also sends a control signal to synthesizer 9 to switch the control channel to the selected vacant speech channel, step 114. Then, control cir-cuit 12 sends control signals b, c and d to switches 34, 35 and 36 to connect hybrid circuit 4 to amplifier 37 and disconnect hybrid cir-cuit 4 from transmitter S and receiver 8, step 115. Therefore, the radio telephone apparatus is placed in a receiving loudspeaker mode with loudspeaker 38. In this state, since the dial tone from wired ~36 telephone line 3 is supplied to loudspeaker 38 through line relay 33, hybrid circuit 4, switch 35 and amplifier 37, the dial tone is gener-ated by loudspeaker 38. Thereafter, control circuit 12 generates a dialing signal in response to the received dialing signal and sends the generated dialin~ signal to wired telephone line 3 when receiving dialing signal from radio telephone set 2, steps 116 and 117. After the call origination operation is carried out, a ringing signal from wired telephone line 3 is generated by loudspeaker 38 when the called telephone set is not busy. If the called party responds to this call, the responding voice signal from the called telephone set is generated by loudspeaker 38. When the called telephone set is busy, a busy tone from wired telephone line 3 is generated by loudspeaker 38. This receiving loudspeaker mode with loudspeaker 38 is contin-ued while radio telephone æt 2 i5 installed in base unit 1, step 118.
In this state, when the end signal is received from radio telephone set 2, step 120, control circuit 12 carries out the end of speech oper-ation as described above, steps 110, 111 and 112.
If the user picks up radio telephone set 2 after hearing the ringing signal or the response voice signal from loudspeaker 38, con-trol clrcuit 12 determines radio telephone set 2 is not installed in base unit 1 according to the level of voltage a, step 118. Control circuit 12 then sends control signals b, c and d to switches 34, 35 and 36, in order to connect hybrid circuit g to transmitter 5 and receiver 8, and disconnect hybrid circuit 4 from amplifier 37.
Therefore, the radio telephone apparatus is placed in the normal mode and uses speaker 15 and microphone 16 instead of the recei~r-ing ioudspeaker mode.
Figure 4 illustrates the second embodiment of the invention.
The difference between the second and first embodiments is that amplifier 37~ is provided and is capable of selecting two kinds of gains. Signal level detector 39 is also provided. Also, in the second embodiment, switch 3S is eliminated. Signal level detector 39 detects the output signal from receiver 8 and determines whether the detected signal le~rel is beyond a predetermined level. If so, detector 39 sends the detected signal to control circuit 12. Control circuit 12 sends a control signal e to amplifier 37~ to reduce the gain of amplifier 371. Since the gain of amplifier 371 is reduced when the magnitude of the output signal from receiver 8 is increased, the magnitude of the signal generated by loudspeaker 38 ~s reduced. As a result, ~he generated signal is prevented from entering microphone 16. According to this embodiment, the apparatus is able to carry out a loudspeaker communication with loudspeaker 38 and microphone 16, instead of only loudspeaker 38.
The operation of this embodiment is described with reference to the îlow chart shown In Figure 5 as follows. After transmitting the response signal to radio telephone set 2 in response to the calling origlnation signal, step 103, control circuit 12 determines whether radio telephone set 2 is installed in base unit 1, step 104. If so, con-trol circuit 12 determines a loudspeaker communication mode and causes line relay 33 to connect hybrid circuit 4 to wired telephone line 3, step 113. Control circuit 12 then sends the control signal to synthesizer 9 to switch the control channel to the speech channel, step 114, and control signals b and c to switches 34 and 35 to con-nect hybrid circuit 4 to amplifier 371 and to disconnect hybrid circuit 4 from transmitter 5, step 125. Therefore, the radio tele-phone apparatus is in the loudspeaker communication mode with loudspeaker 38 and microphone 16. In this state, the dial tone from wired telephone line 3 is generated by loudspeaker 38 until contrd 368~) circuit 12 sends the dialing signal to wired telephone line 3. After the speech path between the caLled telephone set and base unit 1 is established according to the dialing signal, steps 116 and 117, control circuit 12 determines the output of detector 39. If control circuit 12 determines the detected signal from detector 39 is supplied, step 126, it sends the control signal e to amplifier 37' to reduce the gain, step 127. If control circuit 12 determines the detected signal is not supplied, step 126, it stops sending the control signal e to amplifier 37~ to return it to the initial gain.
This loudspeaker communication mode is continued while radio telephone set 2 Is installed in base unit 1, step 118. In this state, when the end signal is received from radio telephone set 2, step 120, control circuit 12 carries out the end operation as described in the above embodiment, steps 110, 111 and 112.
If the user picks up radio telephone set 2 in this loudspeaker communication mode, control circuit 12 sends control signals b and c to switches 34 and 35, in order t~ connect hybrid circuit 4 to transmitter 5 and disconnect hybrid circuit 4 from amplifier 37~, step 128. Therefore, the radio telephone apparatus is returned to the normal mode with speaker 15 and microphone 16 instead of the loudspeaker communication mode.
Figure 6 illustrates the third embodiment of the invention. In this embodiment, not only is the receiving loudspeaker operation carried out as described above first embodiment, but the loudspeaker communication is carried out as described above in the second embodiment. Also, in this embodiment, loudspeaker switch 40 is arranged on the top surface of base unit 1 as shown in Figure ~. The operation of this embodiment is described with reference to the flow chart shown in Figures 8 and 9 as follows.
~3~
Af ter transmitting the response signal to radio telephone set 2 in response to the calling origination signal, step 103, control circuit 12 determines whether loudspeaker switch 40 is depressed, step 132. If so, control circuit 12 further determines whether radio telephone set 2 is installed in base unit 1, step 104. ~ not, control circuit 12 sends control signals b, c and d to switches 34, 35 and 36, in order to connect hybrid circuit 4 to receiver 8 and amplifier 37', and disconnect hybrid circuit 4 from transmitter 5, step 133. Ther~
fore, the loudspeaker communication is carried out with loudspeaker 38 and microphone 16 after the speech path between the called telephone set and base unit 1 is established. Thereafter, when loudspeaker switch 40 is depressed and is in the OFF-state, step 134, control circuit 12 sends controls signals b, c and d to switches 34, 35 and 36, in order to disconnect hybrid circult 4 from amplif ier 37' and connect hybrid circuit 4 to transmitter 5 and receiver 8, step 135. Therefore, the radio telephone apparatus is placed in the normal mode with speaker 15 and microphone 16.
If control circuit 12 determines radio telephone set 2 is installed In base unit 1 In step 104, it causes line relay 33 to connect wired telephone llne 3 to hybrid circuit 4 and syntehsizer 9 to switch the control channel to the speech channel, steps 140 and 141. Con-trol circuit 12 then sends control signals b, c and d to switches 34, 35 and 36, in order to connect hybrid circuit 4 to amplifier 37' and dis-connect hybrid circuit 4 from transmitter 5 and receiver 8, step 142.
Thus, the receiving loudspeaker operation is carried out. In this state, control circuit 12 always causes amplifier 3r to select higher gain by the control signal e. When control circuit 12 determines radio telephone set 2 is not installed in base unit 1 in the receiving ~oudspeaker operation, step 146, control circuit 12 sends control signals b, c and d to switches 34, 35 and 36, in order to disconnect hybrid circuit 4 from transmitter 5 and connect hybrid circuit 4 to receiver 8 and amplifier 38, step 133. The radio telephone apparatus is placed In the loudspeaker communication mode with loudspeaker 38 and microphone 16. When control circuit 12 also receives the end signal from radio telephone set 2 in the receiving loudspeaker operation, step 147, it sends control signals b, c and d to the switches, in order to disconnect hybrid circuit 4 f rom amplifier 37I and connect hybrid circuit 4 to transmitter 5 and receiver 8, step 148. Thereafter, control circuit 12 carries out the end operation as described above, steps 110, 111 and 112.
According to this embodiment, when loudspeaker switch 40 is in the ON-state and radio telephone set 2 is installed in base unit 1, in the normal mode, steps 137 and 138, the radio telephone appara-tus is placed in the receiving loudspeaker mode. Also, when loud-speaker switch 40 is in the ON~tate and radio telephone set 2 is not installed in base unit 1, in the normal mode, steps 137 and 138, the radio telephone apparatus is placed in the loudspeaker communica-tion modè. Furthermore, when radio telephone set 2 is installed in base unit 1, ln the loudspeaker communication mode, step 136, the radio telephone apparatus is placed in the receiving loudspeaker mode.
Figure 10 shows another operation of the third embodiment described in Figure 6. According to this embodiment, the apparatus is able to operate the calling origination in response to the depres-sion of loudspeaker switch 40, instead oî the operation of calling origination key 31.
When control circuit 12 determines loudspeaker switch 40 is in the ON-state by being depressed in the waiting state, step 151, it ~S~n sends a connection signal to transmitter 5 after transmitter 5 is turned on, steps 152 and 153. Transmitter 5 transmits the connec-tion signal to radio telephone set 2 through the control channel. The connection signal includes the speech channel signal indicating the found vacant speech channel and the predetermined identification signed.
Control circuit 12 then sends the control signals to synthesizer 9 and line relay 33 to select the vacant speech channel and connect hybrid circuit 4 to wired telephone line 3, steps 154 and 155. Thereafter, control circuit 12 determines whether radio tele-phone set 2 is installed in base unit 1, step 156. If so, the radio tele-phone apparatus is placed in the receiving loudspeaker mode, and if not, it is placed in the loudspeaker communication mode, as described above.
On the other hand, when control circuit 22 determines the connection signal is received, step 220, it sends the control signal to synthesizer 19 to select the indicated speech channel after transmitter 17 is turned on, steps 221 and 222. Thus, the speech path betweeQ base unit 1 and radio telephone set 2 is established.
In the preferred embodiments, the end operation is carried out by operation of key 31. However, base unit 1 may detect the fact that the called telephone set is disconnected from wired tele-phone line according to the end operation and carry out the end operation, as well known in the art.
Also, in the above-described embodiments, signal level detector 39 determines whether the output signal level from receiver 8 is beyond one predetermined level and amplifier 3r selects one of two gains by the control signal e f rom control circuit 12. However, detector 39 may compare the output signal 6a~
level with a plurality of predetermined levels and amplifier 37~ may select one of a plurality of gains accordlng to the signal level dete~
mined by detector 39.
Further, in the above-described embodiments, control circuit 12 determines whether radio telephone set 2 is installed in base unit 1 according to the voltage a corresponding to the charging current. However, control circuit 12 may determine the installed state according to the particular switch arranged on base unit 1.
The particular switch may be in particular switching state such as the ON-state when radio telephone set 1 is installed in base unit 1.
Furthermore, transmitters 5 and 1~ may reduce the transmitting power when radio telephone set 2 is installed in base unit 1 to reduce the consumption of the current. Also, control circuit 12 may send a dialing signal to control circuit 12 through the charging line includ-ing terminals 27 and 28 when radio telephone set 2 is installed in base unit 1.
While the invention has been described herein by reference to several preferred embodiments, various modifications can be made without departing from the true scope and spirit of the invention. It is my intention, there~ore, by the appended claims, to embody all such modifications.
When a call signal arrives at the wired telephone line, the base unit transmits a paging signal to the radio telephone set through a predetermined control channel to ~orm a speech channel.
The paging signal includes a channel signal indicating one of a plurality of speech channels. Then, the radio telephone set starts an operation to send out a paging response signal through the control channel in response to the received paging signal. The base unit detects the intensity of the received paging response signal sent out from the radio telephone set, I.e., the intensity of the paging response signal at the control channel. Then, the base unit stops the transmlssion of the paging signal when the detected intensity exceeds a predetermined level and switches the radio channel between the base unit and the radio telephone set from the control channel to the speech channel indicated in the paging signal. The radio telephone set also switches the radio channel from the control channel to the speech channel by the received paging signal. There-after, the base unit transmits a ringing signal to the radio telephone set via the speech channel. After transmitting the ringing signal, the base unit establishes a speech path between the wired telephone line and the radio telephone set when it receives an ~'of~-hook" signal from the radio telephone set indicating that the handset is ~'off the hook~'.
When the base unit is in a waiting state and receives a call origination signal (an off-hook signal) from the radio telephone set through the control channel, it determines the call origination request from the radio telephone set and transmits a response signal which includes the channel signal indicating one of the plurality of speech channels. Then, the base unit establishes a speech path between the wired telephone line and itself, and switches the radio channel from the control channel to the speech channel indicated in the response signal. After receiving the response signal, the radio telephone set also switches the radio channel from the control 1~3681~) channel to the speech channel in response to the recelved response signal.
If, in this state, the radio telephone set transmlts dialing sig-nals to the base unit through the speech channel by a dialing opera-5 tion, the dialing signal is transmitted ~o the wired telephone line viathe base unit.
Thus, the radio telephone apparatus carries out the operatlons o~ receiving incoming telephone calls rrom the wired telephone line and originating calls f rom the radio telephone set.
However, the prior art radio telephones sufrer a serious draw-back in that a sufflciently large enough loudspeaker can not be adapted to be used in the apparatus because it is necessary for the radio telephone set to be compact and light. Even ii a loudspeaker w~th a large enough speaker was adapted to be used in the apparatus, 15 lt is extremely difficult to drive ~he loudspeaker to generate speech signals because the capacity of the power source ol the radio tele-phone set ~s not sufflcient to drive the loudspeaker. Generally, the power soùrce is a small storage battery used to drlve the components o~ the radio telephone set. These components typically have low 2 0 power requ~ements. Loudspeakers typically have high power requirements.
SU~MARY OY THE INVENTION
It is, ~f~re, an cb~t o an aspect c~ ~e ~t i~
p~3e a la~OE a~aratus ~rl ne~d fi~r Ee in a r~3io ~le~
2 5 apparatus, which apparatus and method is capable of producing speech signals from another telephone apparatus with a loudspeaker.
It is a~ ~:t c~ an aspect aE ~e E~esent i~ti~ to ~ a apparatus capable of producing speech signals from another tel~
phone apparatus with a loudspeaker, which apparatus is used in a ~ ~6sln radio telephone apparatus and adapted to be made compact and light.
aforestated drawbacks, there is pro~ided a loudspeaker apparatus ~or 5 use in a radio telephone apparatus having a base unit and a radio telephone set so that sound signals may be heard from a loudspeaker in the base unit. The base unit Is coupled to a wired telephone line and connected to the radio telephone set through a radlo channel.
The base unit a~o operates by DC power converted from an AC
10 source. The radlo telephone set is powered by a small storage battery which may be charged by the DC power when the set is installed in or on the base unit. The radio telephone set also includes call origination keys, dialing keys, a microphone and speaker. ~he base unit includes a loudspeaker tor generating sound signals ~rom 15 said wired telephone line and a control clrcuit. The control circuit determines the loudspeaker mode in response to the call origination signal by the operation oI the call origination key ii' the radio tele-phone set is installed in the base unit. The loudspeaker mode is characterized by sound signals being reproduced through at least the 20 loudspeaker o~ the base unit. The control circuit connects the loud-spea~ser to the wired telephone line i~ that loudspeaker mode is determined, so that the sound signals may be heard through the loudspeaker.
- 4a-Various aspects of the invention are as follows:
A loudspeaker apparatus for a radio telephone appara-tus having a base unit coupled to a wired telephone line and a radio telephone set includlng a battery, wherein said radio telephone set is connected to said base unit through a radio channel, said loudspeaker apparatus comprising:
call origination means for generating a call origination signal;
loudspeaker means provided in said base unit for gener-ating a speech signal from said wired telephone line;
mode means provided in said base unit ~or determining at least one loudspeaker mode representing a speech operation with said loudspeaker means; and speech control means provided in said base unit ~or connecting said loudspeaker means to said wired telephone line in response to the call origination signal from said call origination means if the loudspeaker mode Is determined by said mode means.
In a radio telephone apparatus havin~ a base unit cou-pled to a wired telephone line and a radio telephone set lncluding a battery, said radio telephone set being connected to said unit through a radlo channel, a method for implementing loudspeaker mode selection comprising the steps oi:
a) generating a call origination signal;
b) determining a loudspeaker mode representing a speech operation with at least loudspeaker means provided in said base unit; and c) connecting said loudspeaker means to said wired telephone llne in response to the call origination signal if the loud-speaker mode is determined.
~ ~3681~
-4b-A radio telephone apparatus having a base unit coupled to a wired telephone line and a radio telephone set coupled to said base unit through a radio channel, whereln said base unit operates by an AC power source, and said radio telephone set operates by a bat-5 tery, said loudspeaker apparatus comprising:
call origination means tor generating a call originationsignal;
loudspeaker means, powered by said AC power source, ror generating a speech signal from said wired telephone line;
mode means provided in sald base unit rOr determininz a loudspeal~er mode representing a speech operation with at least said loudspeaker means; and speech control means provided in said base unit for connecting said loudspeaker means to said wired tel~
phone line in response to the call origination signal from said call 15 origination means it the loudspeaker mode is determined by said mode means.
BRIEF DESCRIPTION OY THE DRAWINGS
The sub~ect matter which is regarded as the invention is par-ticularly pointed out and distinctly claimed in the claims of the 20 specificatlon. The invention, however, both as to organization and method o~ practice, together with further obiects and advantages thereof, may be best understood by reference to the following ~ ~r~6~31~
detailed description of the invention taken in conjunction with the drawings in which:
Figure 1 shows a first embodiment of the present invention in block diagram form;
Figure 2 is an external view of a radio telephone apparatus of Figure l;
Figure 3 shows a flow chart of a radio telephone apparatus o~
Figure 1;
Figure 4 shows a second embodiment oI the present invention in block diagram form;
Figure 5 shows a flow chart of a radio telephone apparatus of Figure 4;
Figure 6 shows a third embodiment of the present invention in block diagram form;
Figure 7 is an external view of a radio telephone apparatus of Figure 6; and Figures 8 to ten show flow charts of a radio telephone appara-tus of Figure 6.
DETAILED DESCRIPTION
In the embodiment shown in Figure 1, base unit I is connected to a radio telephone set 2 through one ol a plurality ol radio chan-nels including a control channel (C-CH) and a plurality of speech channels (S-CHs), and is also connected to a wired telephone line 3.
Base unit 1 includes AC/DC converter 25 and AC plug 24, in order to produce a DC voltage tVcc) from a commercial power source (AC
power source). The DC voltage is supplied to the electrical compo-nents of base unit 1. Thus, base unit 1 is operated by the converted DC voltage. Radio telephone set 2 includes small storage bat~ery 29 adapted to charge the DC voltage and supply the charged DC voltage ~ ~6~
to electrical components of itseU. Both side terminals of battery 29 are connected to charging terminals 28. When radio telephone set 2 is installed in base unit 1, as shown in Figure 2, charging terminals 28 are connected to supplying terminals 27 of base unit 1. Since one of terminals 27 is connected to AC/DC converter 25 through resistor 26 and another terminal 27 is connected to ground, the converted DC voltage is supplied to battery 29 through resistor 26 and termi-nals 27 and 28. Resistor 26 is a current limiting resistor to limit the current supplied to terminal 27.
A signal sent from wired telephone line 3 is applied to hybrid clrcuit 4 via line relay 33 when line relay 33 is closed (ON~tate).
Hybrid circuit 4 sends the applied signal to switches 34 and 35.
Since switches 34 and 35 are always in a different switching state than each other, the signal from hybrid circuit 4 is supplied to trans-mitter S when switch 34 is closed or to loudspeaker 38 via ampli~ier 37 when switch 35 is clo~ed. Transmitter S modulates a carrier wave according to the supplied signal and transmits the modulated signal to radlo telephone set 2 via transmitting antenna 6. The car rier wave is supplied from synthesizer 9 and has frequency corre-sponding to radio channel selected in a known manner by synthesizer 9.
A signal transmi~ted from radio telephone set 2 Is received by receiving antenna 7 and demodulated by receiver 8 according to the carrier wave supplied from synthesizer 9. The demodulated signal is sent to hybrid circuit 4 when switch 36 is closed and then sent to wired telephone line 3 when line relay 33 is closed. The demodulated signal is also supplied to received field detector 10 and identification signal detector 11. Detector 10 is comprised of a carrier squelch circuit or a noise squelch circuit, and detects the intensity of the ~ ~r36~
received field, whils detector 11 determines whether the identifica-tion signal contained in the demodulated signal corresponds to a spe-cific identification signal allocated to radio telephone set 2. The detected signals frorn detectors 10 and 11 are supplied to control circuit 12. The demodulated signal from receiver 8 is also supplied to control circuit 12 to record a control signal contained in the demodulated signal and adapted to establish a speech path.
The call signal detector 30 detects a call signal (16 Hz signal) sent from wired telephone line 3, and informs control circuit 12 that the call signal has been received.
Control circuit 12 includes a microcomputer, a RAM for sto~
ing data and a ROM containing a stored operations program. Control circuit 12 controls transmitter 5, synthesizer 9, line relay 33, switches 34, 35 and 36 (to establish a speech path in response to the output signals of receiver 8), and detectors 10, 11 and 30. Control circuit 12 also is connected to a connection point between resistor 26 and supplying terminal 2?, and detects ~he voltage a at the con-nection point. The voltage a decreases when ràdio telephone set 2 is installed in ~æe unit 1 because the charging current is supplied to battery 29 through terminals 27 and 28. Control circuit 12 deter-mines that radio telephone set 2 is installed in base unit 1 if the voltage a is within a predetermined range and that radio telephone set 2 is not installed in the base unit 1 if the voltage is not within the predetermined range.
In radio telephone set 2, a signal transmitted from base unit l is received by receiving antenna 13, demodulated by receiver 14 and then applied to speaker 15. In the same manner as in base unit 1, the signal demodulated by receiver 14 is supplied to received signal detector 20, identification signal detector 21 and control circuit 22.
~ ~36~ 0 A voice slgnal inputted into microphone 16 is supplied to the trans-mitter 17 as a modulation input and then transmitted to base unit 1 through transmitting antenna 18. Control circuit 22 includes a microcomputer, a RAM for storing data and a ROM containing a stored operations program. Control circuit 22 controls receiver 14, transmitter 17 and synthesizer 19 (to establish a speech path in response to the output signals of receiver 14), and detectors 2û and 21. Control circuit 22 also causes speaker 23 to produce a ringing sound when i~ determines that a ringing signal is received accordlng to the demodulated signal from receiver 14. Speakers 15, 23 and mlcrophone 16 are adapted to consume very little electricity. Con-trol circuit 22 controls call origination operation in response to key data from calling origination key 31 and dialing key 32. Keys 31 and 32 are arranged on a top surface of radlo telephone set 2, as shown in Figure 2, so æ to be able to operate when radio telephone set 2 is installed in base unit 1. Key 31 is a slide type key and key 32 is a push-type key.
The operation of this embodiment is described wlth reference to the flow chart shown in Figure 3 æ follows.
In a waitlng state, control circuit 12 causes transmitter 5 to turn off and control circ~it 22 causes transmitter 17 to turn of ~, in order to prevent any unnecessary radio waves from radiating. Con-trol circuit 22 further causes receiver 14 to turn on and off periodi-cally to consume a minimal amount of electricity while in the wait-ing state. Also, in the waiting state, switches 34 and 36 are in the ON~tate (closed) and switch 35 is in the OFF-state (opened).
When call origination key 31 is slid to be in the ON-state, the key data is supplied to control circuit 22. Control circuit 22 deter-mines that a request to originate a call has been made in response to ~ ~6~
the supplied key data, step 201, and causes transmitter 17 to turn on, step 202. Control circuit 22 then sends a call origination signal to transmitter 17 to modulate and transmit the call origination signal, step 203. In this state, synthesizer 19 supplies a carrier wave, cor-responding to a control channel, to transmitter 17. A~ter transmit-ting the call origination signal, control circuit 22 causes receiver 14 to turn on continuously.
The transmitted call origination signal is received and demodulated by receiver 8. The demodulated signal is supplied to control circuit 12. When it is determined that the demodulated sig-nal is a call origination signal, step 101, control circuit 12 causes transmitter 5 to turn on, step 102. Control circuit 12 then sequen-tially switches the receiving channel to one of the plural~ty of speech channels to find a vacant speech channel. I~ control circuit 12 finds a vacant speech channel, it sends a response signal to trans-mitter 5 to modulate and transmit the response signal through the control channel, step 103. The response signal includes a speech channel signal indicating the vacant speech channel and a predeter-mined identification signal. Control circuit 12 then determines whether radio telephone set 2 is installed in base unit 1 according to the level oI voltage a, step 104. If not, control circuit 12 determines a normal mode and sends a control signal to line relay 33 to connect wired telephone line 3 to hybrid circuit 4, step 105. Control circuit 12 sends a control signal to synthesizer 9 to switch the control chan-nel to the selected vacant speech channel, step 106.
When receiver 14 receives the transmitted response signal, receiver 14 demodulates the signal and sends the demodulated signal to control circuit 22. When control circuit 22 determines the demodulated signal is the response signal, step 204, it sends a control 8~
signal to synthesizer 9 to switch the control channel to the indicated speech channel according to the speech channel signal in the response signal, step 205. In making this determination, control circuit 22 compares the identification signal in the response signal to its identification data. If control circuit 22 determines the identi-fication signal doesn't correspond to its identiIication data, it doesn~t respond to the demodulated signal. If the corresponding response signal is not received for a predetermined period, step 205, control circuit 22 annuls the received request for call origination and causes transmitter 17 to turn off, step 212. Control circuit 22 also causes receiver 14 to turn on and off periodlcally. Therefore, radio tele-phone set 2 is again in the waiting state.
When the speech channel between base unit 1 and radio tele-phone set 2 is established, a dial tone from wired telephone line 3 is transmitted to radio telephone set 2 and is generated by spea}cer 15.
The dialing key 32 is depressed to transmit a dialing signal to base unit 1 after the dial tone is heard through speaker 15. Control cir-cuit 22 receives the dialing key data from dialing key 32 and pro-vides the data to transmitter 17, steps 207 and 208. Transmitter 17 modulates and transmits the dialing signal through the speech chan-nel in response to the received data. When the dialing signal is received by ~eceiver 8, receiver 8 demodulates ~he dialing signal and provides the demodulated dialing signal to control circuit 12. Con-trol circuit 12 sends a dialing signal, such as a DTMF (dual tone multi-frequency) signal or a DP (dial pulse) signal, to wired tele-phone line 3, in response to the demodulated dialing signal, steps 107 and 108. Thus, the call origination operation is carried out and the radio telephone apparatus is placed in a communication state.
~ ~36~
Thereafter, when call origination key 31 is slid to be in its initial position, control circuit 22 determines the end oî speech and sends an end slgnal to transmitter 17 to transmit the end signal to base unit 1, steps 209 and 210. Control circuit 22 then sends a con-trol signal to synthesizer 19 to switch the speech channel to the control channel, step 211, and causes transmitter 17 to turn off, step 212. Control circuit 22 also causes receiver 14 to turn on and off periodically. Therefore, radio telephone set 2 is in the waiting state again.
When the end signal is received by receiver 8, receiver 8 demodulates the end signal and sends the end signal to control cir-cuit 12. Control circuit 12 sends a control signal to synthesizer 9 to switch the speech channel to the control channel in response to the received and demodulated end signal, steps 109 and 110. Control circuit 12 then sends control signals to line relay 33 and transmitter 5 to disconnect wired telephone line 3 ~rom hybrid circuit 4 and turn off transmitter 5, steps 111 and 112. Therefore, bæe unit 1 is also in the waiting state again.
~ control circuit 12 determines radio telephone set 2 is installed in base unit I at step 104, it determines a loudspeaker mode and sends a control signal to line relay 33 to connect wired tele-phone llne 3 to hybrid circuit 4, step 113. Control circuit 12 also sends a control signal to synthesizer 9 to switch the control channel to the selected vacant speech channel, step 114. Then, control cir-cuit 12 sends control signals b, c and d to switches 34, 35 and 36 to connect hybrid circuit 4 to amplifier 37 and disconnect hybrid cir-cuit 4 from transmitter S and receiver 8, step 115. Therefore, the radio telephone apparatus is placed in a receiving loudspeaker mode with loudspeaker 38. In this state, since the dial tone from wired ~36 telephone line 3 is supplied to loudspeaker 38 through line relay 33, hybrid circuit 4, switch 35 and amplifier 37, the dial tone is gener-ated by loudspeaker 38. Thereafter, control circuit 12 generates a dialing signal in response to the received dialing signal and sends the generated dialin~ signal to wired telephone line 3 when receiving dialing signal from radio telephone set 2, steps 116 and 117. After the call origination operation is carried out, a ringing signal from wired telephone line 3 is generated by loudspeaker 38 when the called telephone set is not busy. If the called party responds to this call, the responding voice signal from the called telephone set is generated by loudspeaker 38. When the called telephone set is busy, a busy tone from wired telephone line 3 is generated by loudspeaker 38. This receiving loudspeaker mode with loudspeaker 38 is contin-ued while radio telephone æt 2 i5 installed in base unit 1, step 118.
In this state, when the end signal is received from radio telephone set 2, step 120, control circuit 12 carries out the end of speech oper-ation as described above, steps 110, 111 and 112.
If the user picks up radio telephone set 2 after hearing the ringing signal or the response voice signal from loudspeaker 38, con-trol clrcuit 12 determines radio telephone set 2 is not installed in base unit 1 according to the level of voltage a, step 118. Control circuit 12 then sends control signals b, c and d to switches 34, 35 and 36, in order to connect hybrid circuit g to transmitter 5 and receiver 8, and disconnect hybrid circuit 4 from amplifier 37.
Therefore, the radio telephone apparatus is placed in the normal mode and uses speaker 15 and microphone 16 instead of the recei~r-ing ioudspeaker mode.
Figure 4 illustrates the second embodiment of the invention.
The difference between the second and first embodiments is that amplifier 37~ is provided and is capable of selecting two kinds of gains. Signal level detector 39 is also provided. Also, in the second embodiment, switch 3S is eliminated. Signal level detector 39 detects the output signal from receiver 8 and determines whether the detected signal le~rel is beyond a predetermined level. If so, detector 39 sends the detected signal to control circuit 12. Control circuit 12 sends a control signal e to amplifier 37~ to reduce the gain of amplifier 371. Since the gain of amplifier 371 is reduced when the magnitude of the output signal from receiver 8 is increased, the magnitude of the signal generated by loudspeaker 38 ~s reduced. As a result, ~he generated signal is prevented from entering microphone 16. According to this embodiment, the apparatus is able to carry out a loudspeaker communication with loudspeaker 38 and microphone 16, instead of only loudspeaker 38.
The operation of this embodiment is described with reference to the îlow chart shown In Figure 5 as follows. After transmitting the response signal to radio telephone set 2 in response to the calling origlnation signal, step 103, control circuit 12 determines whether radio telephone set 2 is installed in base unit 1, step 104. If so, con-trol circuit 12 determines a loudspeaker communication mode and causes line relay 33 to connect hybrid circuit 4 to wired telephone line 3, step 113. Control circuit 12 then sends the control signal to synthesizer 9 to switch the control channel to the speech channel, step 114, and control signals b and c to switches 34 and 35 to con-nect hybrid circuit 4 to amplifier 371 and to disconnect hybrid circuit 4 from transmitter 5, step 125. Therefore, the radio tele-phone apparatus is in the loudspeaker communication mode with loudspeaker 38 and microphone 16. In this state, the dial tone from wired telephone line 3 is generated by loudspeaker 38 until contrd 368~) circuit 12 sends the dialing signal to wired telephone line 3. After the speech path between the caLled telephone set and base unit 1 is established according to the dialing signal, steps 116 and 117, control circuit 12 determines the output of detector 39. If control circuit 12 determines the detected signal from detector 39 is supplied, step 126, it sends the control signal e to amplifier 37' to reduce the gain, step 127. If control circuit 12 determines the detected signal is not supplied, step 126, it stops sending the control signal e to amplifier 37~ to return it to the initial gain.
This loudspeaker communication mode is continued while radio telephone set 2 Is installed in base unit 1, step 118. In this state, when the end signal is received from radio telephone set 2, step 120, control circuit 12 carries out the end operation as described in the above embodiment, steps 110, 111 and 112.
If the user picks up radio telephone set 2 in this loudspeaker communication mode, control circuit 12 sends control signals b and c to switches 34 and 35, in order t~ connect hybrid circuit 4 to transmitter 5 and disconnect hybrid circuit 4 from amplifier 37~, step 128. Therefore, the radio telephone apparatus is returned to the normal mode with speaker 15 and microphone 16 instead of the loudspeaker communication mode.
Figure 6 illustrates the third embodiment of the invention. In this embodiment, not only is the receiving loudspeaker operation carried out as described above first embodiment, but the loudspeaker communication is carried out as described above in the second embodiment. Also, in this embodiment, loudspeaker switch 40 is arranged on the top surface of base unit 1 as shown in Figure ~. The operation of this embodiment is described with reference to the flow chart shown in Figures 8 and 9 as follows.
~3~
Af ter transmitting the response signal to radio telephone set 2 in response to the calling origination signal, step 103, control circuit 12 determines whether loudspeaker switch 40 is depressed, step 132. If so, control circuit 12 further determines whether radio telephone set 2 is installed in base unit 1, step 104. ~ not, control circuit 12 sends control signals b, c and d to switches 34, 35 and 36, in order to connect hybrid circuit 4 to receiver 8 and amplifier 37', and disconnect hybrid circuit 4 from transmitter 5, step 133. Ther~
fore, the loudspeaker communication is carried out with loudspeaker 38 and microphone 16 after the speech path between the called telephone set and base unit 1 is established. Thereafter, when loudspeaker switch 40 is depressed and is in the OFF-state, step 134, control circuit 12 sends controls signals b, c and d to switches 34, 35 and 36, in order to disconnect hybrid circult 4 from amplif ier 37' and connect hybrid circuit 4 to transmitter 5 and receiver 8, step 135. Therefore, the radio telephone apparatus is placed in the normal mode with speaker 15 and microphone 16.
If control circuit 12 determines radio telephone set 2 is installed In base unit 1 In step 104, it causes line relay 33 to connect wired telephone llne 3 to hybrid circuit 4 and syntehsizer 9 to switch the control channel to the speech channel, steps 140 and 141. Con-trol circuit 12 then sends control signals b, c and d to switches 34, 35 and 36, in order to connect hybrid circuit 4 to amplifier 37' and dis-connect hybrid circuit 4 from transmitter 5 and receiver 8, step 142.
Thus, the receiving loudspeaker operation is carried out. In this state, control circuit 12 always causes amplifier 3r to select higher gain by the control signal e. When control circuit 12 determines radio telephone set 2 is not installed in base unit 1 in the receiving ~oudspeaker operation, step 146, control circuit 12 sends control signals b, c and d to switches 34, 35 and 36, in order to disconnect hybrid circuit 4 from transmitter 5 and connect hybrid circuit 4 to receiver 8 and amplifier 38, step 133. The radio telephone apparatus is placed In the loudspeaker communication mode with loudspeaker 38 and microphone 16. When control circuit 12 also receives the end signal from radio telephone set 2 in the receiving loudspeaker operation, step 147, it sends control signals b, c and d to the switches, in order to disconnect hybrid circuit 4 f rom amplifier 37I and connect hybrid circuit 4 to transmitter 5 and receiver 8, step 148. Thereafter, control circuit 12 carries out the end operation as described above, steps 110, 111 and 112.
According to this embodiment, when loudspeaker switch 40 is in the ON-state and radio telephone set 2 is installed in base unit 1, in the normal mode, steps 137 and 138, the radio telephone appara-tus is placed in the receiving loudspeaker mode. Also, when loud-speaker switch 40 is in the ON~tate and radio telephone set 2 is not installed in base unit 1, in the normal mode, steps 137 and 138, the radio telephone apparatus is placed in the loudspeaker communica-tion modè. Furthermore, when radio telephone set 2 is installed in base unit 1, ln the loudspeaker communication mode, step 136, the radio telephone apparatus is placed in the receiving loudspeaker mode.
Figure 10 shows another operation of the third embodiment described in Figure 6. According to this embodiment, the apparatus is able to operate the calling origination in response to the depres-sion of loudspeaker switch 40, instead oî the operation of calling origination key 31.
When control circuit 12 determines loudspeaker switch 40 is in the ON-state by being depressed in the waiting state, step 151, it ~S~n sends a connection signal to transmitter 5 after transmitter 5 is turned on, steps 152 and 153. Transmitter 5 transmits the connec-tion signal to radio telephone set 2 through the control channel. The connection signal includes the speech channel signal indicating the found vacant speech channel and the predetermined identification signed.
Control circuit 12 then sends the control signals to synthesizer 9 and line relay 33 to select the vacant speech channel and connect hybrid circuit 4 to wired telephone line 3, steps 154 and 155. Thereafter, control circuit 12 determines whether radio tele-phone set 2 is installed in base unit 1, step 156. If so, the radio tele-phone apparatus is placed in the receiving loudspeaker mode, and if not, it is placed in the loudspeaker communication mode, as described above.
On the other hand, when control circuit 22 determines the connection signal is received, step 220, it sends the control signal to synthesizer 19 to select the indicated speech channel after transmitter 17 is turned on, steps 221 and 222. Thus, the speech path betweeQ base unit 1 and radio telephone set 2 is established.
In the preferred embodiments, the end operation is carried out by operation of key 31. However, base unit 1 may detect the fact that the called telephone set is disconnected from wired tele-phone line according to the end operation and carry out the end operation, as well known in the art.
Also, in the above-described embodiments, signal level detector 39 determines whether the output signal level from receiver 8 is beyond one predetermined level and amplifier 3r selects one of two gains by the control signal e f rom control circuit 12. However, detector 39 may compare the output signal 6a~
level with a plurality of predetermined levels and amplifier 37~ may select one of a plurality of gains accordlng to the signal level dete~
mined by detector 39.
Further, in the above-described embodiments, control circuit 12 determines whether radio telephone set 2 is installed in base unit 1 according to the voltage a corresponding to the charging current. However, control circuit 12 may determine the installed state according to the particular switch arranged on base unit 1.
The particular switch may be in particular switching state such as the ON-state when radio telephone set 1 is installed in base unit 1.
Furthermore, transmitters 5 and 1~ may reduce the transmitting power when radio telephone set 2 is installed in base unit 1 to reduce the consumption of the current. Also, control circuit 12 may send a dialing signal to control circuit 12 through the charging line includ-ing terminals 27 and 28 when radio telephone set 2 is installed in base unit 1.
While the invention has been described herein by reference to several preferred embodiments, various modifications can be made without departing from the true scope and spirit of the invention. It is my intention, there~ore, by the appended claims, to embody all such modifications.
Claims (22)
1. A loudspeaker apparatus for a radio telephone appara-tus having a base unit coupled to a wired telephone line and a radio telephone set including a battery, wherein said radio telephone set is connected to said base unit through a radio channel, said loudspeaker apparatus comprising:
call origination means for generating a call origination signal;
loudspeaker means provided in said base unit for gener-ating a speech signal from said wired telephone line;
mode means provided in said base unit for determining at least one loudspeaker mode representing a speech operation with said loudspeaker means; and speech control means provided in said base unit for connecting said loudspeaker means to said wired telephone line in response to the call origination signal from said call origination means if the loudspeaker mode is determined by said mode means.
call origination means for generating a call origination signal;
loudspeaker means provided in said base unit for gener-ating a speech signal from said wired telephone line;
mode means provided in said base unit for determining at least one loudspeaker mode representing a speech operation with said loudspeaker means; and speech control means provided in said base unit for connecting said loudspeaker means to said wired telephone line in response to the call origination signal from said call origination means if the loudspeaker mode is determined by said mode means.
2. The apparatus of claim 1 wherein said mode means comprises:
first determining means for determining if said radio telephone set is installed in said base unit; and second determining means for determining the loud-speaker mode in response to the call origination signal if said radio telephone set is installed in said base unit.
first determining means for determining if said radio telephone set is installed in said base unit; and second determining means for determining the loud-speaker mode in response to the call origination signal if said radio telephone set is installed in said base unit.
3. The apparatus of claim 2 wherein said first determin-ing means is means for determining if said radio telephone set is installed in said base unit in response to a charging current supplied from the power source of said base unit to said battery of said radio telephone set.
4. The apparatus of claim 1 wherein said call origination means is provided in said radio telephone apparatus means and trans-mits the call origination signal to said base unit through the radio channel.
5. The apparatus of claim 1 wherein said call origination means is provided in said base unit.
6. The apparatus of claim 1 wherein said speech control means further connects said wired telephone line to the microphone of said radio telephone set.
7. The apparatus of claim 6 further comprising gain con-trol means for adjusting the magnitude of the speech signal gener-ated by said loudspeaker means in response to the magnitude of the speech signal from said microphone.
8. The apparatus of claim 1 wherein said mode means comprises:
first determining means for determining if said radio telephone set is installed in said base unit; and second determining means for determining a first loud-speaker mode and a second loudspeaker mode in response to the call-ing origination signal, an output signal from said first determining means and key data from a particular key, the first loudspeaker mode representing a speech operation with said loudspeaker means, the second loudspeaker mode representing a speech operation with said loudspeaker means and the microphone of said radio telephone set, and wherein said speech control means is means for connecting said loudspeaker means to said wired telephone line if the first loud-speaker mode is determined and connecting said loudspeaker means and said microphone to said wired telephone line if the second loud-speaker mode is determined.
first determining means for determining if said radio telephone set is installed in said base unit; and second determining means for determining a first loud-speaker mode and a second loudspeaker mode in response to the call-ing origination signal, an output signal from said first determining means and key data from a particular key, the first loudspeaker mode representing a speech operation with said loudspeaker means, the second loudspeaker mode representing a speech operation with said loudspeaker means and the microphone of said radio telephone set, and wherein said speech control means is means for connecting said loudspeaker means to said wired telephone line if the first loud-speaker mode is determined and connecting said loudspeaker means and said microphone to said wired telephone line if the second loud-speaker mode is determined.
9. The apparatus of claim 8 wherein said first determin-ing means is means for determining said radio telephone set is installed in said base unit in response to a charging current supplied from the power source of said base unit to said battery of said radio telephone set.
10. The apparatus of claim 8 further comprising gain con-trol means for adjusting the magnitude of the speech signal gener-ated by said loudspeaker means in response to the magnitude of the speech signal from said microphone.
11. The apparatus of claim 8 wherein said particular key is provided in said base unit.
12. In a radio telephone apparatus having a base unit cou-pled to a wired telephone line and a radio telephone set including a battery, said radio telephone set being connected to said unit through a radio channel, a method for implementing loudspeaker mode selection comprising the steps of:
a) generating a call origination signal:
b) determining a loudspeaker mode representing a speech operation with at least loudspeaker means provided in said base unit; and c) connecting said loudspeaker means to said wired telephone line in response to the call origination signal if the loud-speaker mode is determined.
a) generating a call origination signal:
b) determining a loudspeaker mode representing a speech operation with at least loudspeaker means provided in said base unit; and c) connecting said loudspeaker means to said wired telephone line in response to the call origination signal if the loud-speaker mode is determined.
13. The method of claim 12 wherein step b), determining the loudspeaker mode, comprises the steps of:
determining if said radio telephone set is installed in said base unit, and determining the loudspeaker mode in response to the call origination signal if said radio telephone set is installed in said base unit.
determining if said radio telephone set is installed in said base unit, and determining the loudspeaker mode in response to the call origination signal if said radio telephone set is installed in said base unit.
14. The method of claim 13 wherein the step of determin-ing if said radio telephone set is installed in said base unit comprises determining a charging current supplied from the power source of said base unit to said battery of said radio telephone set.
15. The method of claim 12 further comprising the step of connecting said wired telephone line to the microphone of said radio telephone set.
16. The method of claim 15 further comprising the step of adjusting the magnitude of the speech signal generated by said loud-speaker means in response to the magnitude of the speech signal from said microphone.
17. The method of claim 12 wherein step b), determining the loudspeaker mode, comprises the steps of:
determining if said radio telephone set is installed in said base unit and generating a determination signal, and determining a first loudspeaker mode and a second loudspeaker mode in response to the call origination signal, the determination signal and key data from a particular key, the first loudspeaker mode representing the speech operation with said loud-speaker means, the second loudspeaker mode representing the speech operation with said loudspeaker means and the microphone of said radio telephone set, and wherein step c), connecting said loud-speaker means, comprises the steps of:
connecting said loudspeaker means to said wired tele-phone line if the first loudspeaker mode is determined, and connecting said loudspeaker means and said microphone to said wired telephone line if the second loudspeaker mode is determined.
determining if said radio telephone set is installed in said base unit and generating a determination signal, and determining a first loudspeaker mode and a second loudspeaker mode in response to the call origination signal, the determination signal and key data from a particular key, the first loudspeaker mode representing the speech operation with said loud-speaker means, the second loudspeaker mode representing the speech operation with said loudspeaker means and the microphone of said radio telephone set, and wherein step c), connecting said loud-speaker means, comprises the steps of:
connecting said loudspeaker means to said wired tele-phone line if the first loudspeaker mode is determined, and connecting said loudspeaker means and said microphone to said wired telephone line if the second loudspeaker mode is determined.
18. The method of claim 17 wherein the step of determin-ing said radio telephone set is installed in said base unit comprises determining a charging current supplied from the power source of said base unit to said battery of said radio telephone set.
19. The method of claim 17 further comprising the step of adjusting the magnitude of the speech signal generated by said loud-speaker means in response to the magnitude of the speech signal from said microphone.
20. A radio telephone apparatus having a base unit coupled to a wired telephone line and a radio telephone set coupled to said base unit through a radio channel, wherein said base unit operates by an AC power source, and said radio telephone set operates by a bat-tery, said loudspeaker apparatus comprising:
call origination means for generating a call origination signal;
loudspeaker means, powered by said AC power source, for generating a speech signal from said wired telephone line;
mode means provided in said base unit for determining a loudspeaker mode representing a speech operation with at least said loudspeaker means; and speech control means provided in said base unit for connecting said loudspeaker means to said wired tele-phone line in response to the call origination signal from said call origination means if the loudspeaker mode is determined by said mode means.
call origination means for generating a call origination signal;
loudspeaker means, powered by said AC power source, for generating a speech signal from said wired telephone line;
mode means provided in said base unit for determining a loudspeaker mode representing a speech operation with at least said loudspeaker means; and speech control means provided in said base unit for connecting said loudspeaker means to said wired tele-phone line in response to the call origination signal from said call origination means if the loudspeaker mode is determined by said mode means.
21. The apparatus of claim 20 wherein said loudspeaker means is provided in said base unit.
22. The apparatus of claim 20 wherein said speech control means further connects said wired telephone line to a microphone powered by said battery.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JPP62-67813 | 1987-03-24 | ||
| JP62067813A JPS63234654A (en) | 1987-03-24 | 1987-03-24 | Radio telephone system |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1286810C true CA1286810C (en) | 1991-07-23 |
Family
ID=13355760
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000562243A Expired - Lifetime CA1286810C (en) | 1987-03-24 | 1988-03-23 | Loudspeaker apparatus and method for a radio telephone apparatus |
Country Status (6)
| Country | Link |
|---|---|
| US (1) | US4969181A (en) |
| EP (1) | EP0284325B1 (en) |
| JP (1) | JPS63234654A (en) |
| KR (1) | KR920000140B1 (en) |
| CA (1) | CA1286810C (en) |
| DE (1) | DE3885325T2 (en) |
Families Citing this family (15)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH0368242A (en) * | 1989-08-07 | 1991-03-25 | Tamura Electric Works Ltd | Radio telephone equipment |
| JPH0370441U (en) * | 1989-11-08 | 1991-07-15 | ||
| JPH0451741A (en) * | 1990-06-20 | 1992-02-20 | Tamura Electric Works Ltd | Cordless telephone set |
| KR940003507B1 (en) * | 1990-08-30 | 1994-04-23 | 금성통신 주식회사 | Cordless telephone system |
| JPH04179356A (en) * | 1990-11-13 | 1992-06-26 | Mitsubishi Electric Corp | Codeless telephone set |
| JP2941963B2 (en) * | 1991-01-17 | 1999-08-30 | キヤノン株式会社 | Cordless telephone equipment |
| DE4130647A1 (en) * | 1991-09-14 | 1993-03-18 | Bosch Gmbh Robert | EMERGENCY CALL DEVICE |
| US5381460A (en) * | 1993-12-30 | 1995-01-10 | Uniden America Corp., | Monitor mode in a portable telephone |
| JPH08331234A (en) | 1995-03-24 | 1996-12-13 | Canon Inc | Telephony system |
| JPH0958U (en) * | 1996-06-04 | 1997-01-21 | シャープ株式会社 | Cordless telephone |
| DE19641755C2 (en) * | 1996-10-10 | 2002-06-13 | Deutsche Telekom Ag | Cordless telephone |
| US6115616A (en) * | 1998-05-28 | 2000-09-05 | International Business Machines Corporation | Hand held telephone set with separable keyboard |
| US6321080B1 (en) * | 1999-03-15 | 2001-11-20 | Lucent Technologies, Inc. | Conference telephone utilizing base and handset transducers |
| JP3599097B2 (en) * | 2000-10-10 | 2004-12-08 | 日本電気株式会社 | Method of calling portable communication device by peripheral device, portable communication device using the same, and peripheral device |
| TW563974U (en) * | 2002-02-06 | 2003-11-21 | Lite On Technology Corp | Electricity saving device for user for user interface terminal device of cellular phone |
Family Cites Families (13)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3124657A (en) * | 1964-03-10 | peterson | ||
| US4309573A (en) * | 1980-04-07 | 1982-01-05 | Gte Automatic Electric Labs Inc. | Loudspeaking substation circuit |
| US4400584A (en) * | 1982-04-05 | 1983-08-23 | Motorola, Inc. | Speakerphone for radio and, landline telephones |
| DE3309877A1 (en) * | 1983-03-18 | 1984-09-20 | Siemens AG, 1000 Berlin und 8000 München | RECORDING FOR CORDLESS TELEPHONE |
| JPS60223340A (en) * | 1984-04-20 | 1985-11-07 | Sony Corp | Cordless telephone set |
| US4640987A (en) * | 1984-04-23 | 1987-02-03 | Keizo Tsukada | Cordless telephone |
| US4706274A (en) * | 1984-05-11 | 1987-11-10 | Southwestern Bell Telecommunications, Inc. | Cordless telephone system |
| JPS6165542A (en) * | 1984-09-05 | 1986-04-04 | Mitsubishi Electric Corp | Cordless telephone set |
| JPS6182541A (en) * | 1984-09-28 | 1986-04-26 | Aisin Seiki Co Ltd | Automobile telephone device |
| JPS61224548A (en) * | 1985-03-28 | 1986-10-06 | Toshiba Corp | Telephone set |
| US4736404A (en) * | 1985-03-29 | 1988-04-05 | American Telephone And Telegraph Company, At&T Technologies Inc. | Security arrangement for cordless telephone system |
| EP0231290A1 (en) * | 1985-07-19 | 1987-08-12 | Custom Product Development Pty. Ltd. | Mobile telephone system |
| JPS63119350A (en) * | 1986-11-07 | 1988-05-24 | Aihon Kk | Cordless speaking device |
-
1987
- 1987-03-24 JP JP62067813A patent/JPS63234654A/en active Pending
- 1987-07-08 US US07/071,194 patent/US4969181A/en not_active Expired - Lifetime
-
1988
- 1988-03-21 EP EP88302447A patent/EP0284325B1/en not_active Revoked
- 1988-03-21 DE DE88302447T patent/DE3885325T2/en not_active Revoked
- 1988-03-23 CA CA000562243A patent/CA1286810C/en not_active Expired - Lifetime
- 1988-03-24 KR KR1019880003171A patent/KR920000140B1/en not_active IP Right Cessation
Also Published As
| Publication number | Publication date |
|---|---|
| EP0284325A2 (en) | 1988-09-28 |
| EP0284325B1 (en) | 1993-11-03 |
| US4969181A (en) | 1990-11-06 |
| EP0284325A3 (en) | 1990-11-22 |
| DE3885325D1 (en) | 1993-12-09 |
| KR880012057A (en) | 1988-11-03 |
| JPS63234654A (en) | 1988-09-29 |
| KR920000140B1 (en) | 1992-01-09 |
| DE3885325T2 (en) | 1994-03-10 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| MKLA | Lapsed |