WO1999004532A2

WO1999004532A2 - Method and device for indicating the price and designation of an article on stands for goods

Info

Publication number: WO1999004532A2
Application number: PCT/DE1998/001942
Authority: WO
Inventors: Dietrich Roscher; Udo Wolf; Holger Klingner
Original assignee: Meonic System Engineering Gmbh
Priority date: 1997-07-14
Filing date: 1998-07-11
Publication date: 1999-01-28
Also published as: CA2295624A1; WO1999004532A3; EP1002265A2; AU9252298A; DE19730051A1; JP2001510923A

Abstract

The invention concerns a method and a device for indicating prices, designation of an article or similar types of information on supports for goods in departmental stores or warehouses. The device is characterised by a graphic display system comprising bistable image cells requiring energy supply only when the image content is modified. The display of the article designation together with its price and other types of information simplifies the installation of the device by establishing a reference between the number of the article to be labelled, the electronic label identification number and an identification number for the site of the article on its support, whereto are added the designation and the price of the article stored in a control unit by means of a mobile data acquiring apparatus, the whole forming a data set for the article. The display device placed on the goods support has an image zone consisting of parallel display channels connected to non-visible overflow channels. At least two contrasting fluids are delivered into the display channels by micro-pumps operating alternately, on the basis of the image content to be produced, the required image quality being ensured by a phase-locking circuit wherein are integrated the micro-pumps and the sensors.

Description

Device and method for displaying prices and article designations on goods carriers

The invention relates to a device and a method for displaying prices, article descriptions and similar information on product carriers in department stores and warehouses with the aid of display devices attached to the product carriers in electronic labels, which are functionally connected to an external control center. that the control center can address a single electronic label and transmit information about that electronic label

Printed labels for labeling goods with prices and similar information are subject to change at irregular intervals. The manual effort is considerable and electronic price display devices have been proposed and are known which use display devices which display the price and similar information and which can be changed by a control center.

Information transfer from a control center to the respective electronic label as well as a power supply for the display device and a control unit in the electronic label are necessary. After devices first became known in which the information from a control center and the power supply via cable connections and conductive tracks are passed to the electronic label (GB 1544005, GB 2083673), an independent functional unit is proposed as an electronic label in US Pat. No. 5,313,569, contains the display device, control unit and power supply and is directly or indirectly connected to the control center. The information on item number The name and price of the item (see also EP 0228 377) are stored in changeable registers in the electronic label, the content of which is compared by a microprocessor forming the control unit in the electronic label with the information received from the control center, possibly changed and displayed. The address of the label is determined by the article number stored in a register and can therefore also be changed.

All these devices require a constant supply of energy in the operating state to ensure the display, whether in the form of a built-in battery, a solar cell or a wired power supply. This creates considerable disadvantages for these devices

For example, it is not acceptable for the operator of such a pricing device to replace batteries during the life of the electronic label. The available area of the electronic label limits the size of the solar cells. Wired power supplies limit flexibility considerably. The design of the electronic label as an independent functional unit with its own power supply therefore limits the practical design of the display device to an LCD type, although numerical values about article prices and quantities are displayed, but in the known designs, they are limited to textual representations because of the required energy requirement of the display device must be waived. The result is a correspondingly high installation effort for the price labeling device, which requires a high level of care by the operating personnel. Finally, the electronic label with a logical address derived from the article number must be placed near the article in question. This arrangement must also be so clear for the potential buyer of the article that no confusion is possible. This clear relationship of the label to the product in question is only possible with clearly structured goods carriers, such as shelves, without additional aids. In order to create a clear relationship between the article and the electronic label for the entire variety of product carriers for the customer as well, additional paper stickers are often affixed to the electronic label that bear the name of the associated article. This measure further increases the installation effort.

DE - 196 48 937 proposes a display type that does not require any additional energy to obtain the item information shown. If one assumes that the textual representation of the article designation is rarely changed, the overall energy balance is more favorable. It is disadvantageous that the arrangement of pixel-related heating and field electrodes causes a high density of conductor tracks and a high number of connections to the control unit. In addition, the dissipation of the heat via the substrate in turn worsens the energy balance. Here too, it remains open how the installation effort can be reduced, apart from the fact that no paper stickers on the electronic label are necessary.

The invention has for its object to provide a device and a method for electronic labeling of goods of the type mentioned that uses numerical, alphanumeric or graphic article information suitable for labeling goods, which can be changed by a control center, flexible in the Installation that is clear for the customer, no energy is required to obtain the display information and avoids the disadvantages mentioned above.

The object is achieved in that the electronic label has a graphic display device, the special feature of which is the energetically bistable, contrast-producing image cells. In the electronic see label there is a receiving communication module that contains a ROM with a fixed, unique label identification number and an address comparator for comparing the label identification number with the address signals of the external control center. If there is a match, the image content is forwarded to the graphic display device via a gate. A mobile data acquisition device with a reading head for barcodes detects an equipment identification number arranged on the goods carrier, an identification number arranged on the electronic label and the item number arranged on the article, which are expediently designed in the form of barcodes, for setting up the device and transmits this information to the external control center. The graphic display device is designed as a fluidic system in that, in accordance with the image content, at least two fluids differing in contrast are conveyed into a meandering channel, this meander consisting of vertical or horizontal, parallel viewing channels and overflow channels connecting the viewing channels. If a change in the image content is required, the old image content is displaced by the new image content and pushed into a separator, at the outputs of which the separated fluids are again available to the respective micropumps. The fluidic system is now closed. The two fluids can be separated at different weights by the action of gravity. In another embodiment of the invention, a magnetically conductive fluid is used and the separation is carried out by the action of a magnetic field. The required precision of the metering of the two fluids through the micropumps is achieved in that a measuring channel is provided which determines the flow rate of the fluid through optically acting sensors and controls the delivery rate of the micropumps with the result. The entire control of the pump power is preferably carried out as a phase locked loop, contrast changes being inserted at constant time intervals in the image content transmitted by the control center, which changes to synchronize the pump power with the transmission rate of the image content are provided. The entire fluidic system is introduced into a base body made of 100-oriented silicon wafers by anisotropic etching. This results in v-shaped channels with precise, reproducible cross sections. The base body with its channels is covered by an anodically bonded glass or silicon cover layer. The two micropumps have rectangular pumping chambers. The cover layer acts as a membrane, which forms a bimorph together with a glued-on silicon wafer. Using different dynamic flow resistances in the inlet and outlet to the pumping chamber, a sawtooth-shaped control of the piezo disks results in a resulting volume flow of the fluid. Additional sensors are provided in the processes from the pump chamber to the mixer in order to prevent a backflow of fluid into the pump, which is inactive for the image build-up, by countermeasures. The entire fluidic system is filled through a special filling opening which expediently opens into the mixer for the different fluid flows. The electronic label, the control center and the mobile data acquisition device are expediently connected by wireless transmission channels.

In one embodiment, the fluidic system is introduced into a base body made of plastic. The corresponding microstructures of the pumping chambers and meandering channels are worked into a plastic board. The overflow channels of the meander and the supply and discharge lines to the mixer and measuring channel can thus advantageously be rounded off. This results in lower flow resistances for the fluid. In addition, channel transitions and channel connections with different cross sections are conical or widening and also improve the flow behavior of the fluid. The meander is arranged with horizontal view channels and therefore requires a smaller number of channel transitions. In a further embodiment, the horizontal viewing channels are formed by two or more meander systems, which are, however, connected to a common depot or separator. With this version, separately adjustable multi-line display fields can be implemented. In the event of changes, for example the image content of only one line, only the image content of this meandering line is changed, while the image content of the other lines is retained. The energy expenditure required for changing the image content can thus be reduced.

In an advantageous embodiment of the device, the view channels of the meander are covered with an aperture. The vertical webs of the panel conceal the edge area of the visible drawing pixels. With this diaphragm, which is expediently a metal diaphragm, residual inaccuracies of the positioned drawing pixels are masked out. A contrast-sharp or contour-sharp image or character is thus displayed. The cover also directs the light emission from a stored reflection wall or other light sources. When the base body is made of plastic, the diaphragm also serves as a bimorph for the micropumps.

In a further embodiment of the device, a reflective film with fluorescent inclusions is arranged behind the metal screen, which emits the incident ambient light in a concentrated manner on the visible display surface and thus ensures effective contrast-enhancing background lighting.

In a further embodiment, a light guide is arranged with scattering centers made of fluorescent material, which emits the ambient light incident on the front panel again on special optical surfaces and thus represents an effective backlight without the supply of energy.

The object is further achieved according to the invention by using the device described above and a method in which the article number of the goods read with the aid of a mobile data acquisition device with the ID number of the electronic label arranged in the immediate vicinity of the goods as article data -Connected network, which is transmitted to the control center and is supplemented there with the price and the article name. Derived from this centrally stored combination of article data, the image content for the display devices on the electronic labels but also information for cash registers or warehouse management in the sense of integrated goods management, which also includes the sales area, are derived.

In order to explain the essence of the invention, it is necessary to show which article data combination must be generated by chaining different data so that goods management including the sales area is possible.

The known price labeling devices assume that in the control center there is an assignment of the article, identified by an article number to an article price, and that this chaining must be transferred to the electronic label attached in the vicinity of the respective article. Incidentally, this same chaining is transferred to electronic data counters in sales rooms together with the item designation and is available as a so-called PLU (Price Look Up) table if the article is identified during the sales process and the article price and article name are displayed or displayed for the customer. One of the advantages of such integrated merchandise management systems is that when the item price is changed centrally, for example, the current price is displayed or charged identically both on the electronic label arranged near the item and on the customer display of the cash register. The disadvantages of the known price labeling devices are that the automatic chaining only affects the article price with the article number, other chains must be produced manually and therefore with great effort. This applies in particular to ensuring transparency for the customer as to which electronic label is now assigned to which article in the vicinity.

If it is assumed that a linked data record of the article number, article description and article price already exists in the control center, it seems advisable to transmit the article description electronically to the electronic label and display it. This creates the required transparency for the customer in the assignment of the article to the electronic label, without e.g. an additional paper sticker must be made.

At the same time, this also opens up a better possibility of setting up the price marking device in such a way that an electronic label is assigned to the article in question at the location of the article. Here, too, there is the need, after the electronic label has been assigned to the article, to represent the article name in plain text on the electronic label as confirmation. This ensures maximum flexibility, errors in the installation is corrected immediately, the arrangement of the articles can also be optimized with regard to the optimal use of the available goods carriers on the spot.

In the course of the further automation of goods management, especially in the sales rooms, it is to be expected that the relatively expensive sales areas will also be managed. This means that the potential storage space for items on the product carriers must be encrypted and described in a virtual sales room. This increases the number of data to be linked by another data group that describes the location or locations of the articles. It seems appropriate to expand the article data network to include data on the location of the goods in the sales room.

Here, too, the acquisition and reference formation of the individual data groups is a problem that is best solved on site, i.e. at the location of the goods by entering a code on the goods carrier, which can be recorded with the same mobile data acquisition device.

These organizational principles described can only be realized with a type of display device in the electronic label that is new in its technical design. A combination of an at least alphanumeric, but better graphical display with a particularly low energy requirement is necessary. Common display devices with low energy consumption are LCD displays. Depending on the scope of the display, the power consumption is 50 ... 100 μW. If you limit yourself to numerical (7 segments) characters for the representation of the item price and to a few, firmly structured special characters, no less than 20 μW can be expected as a power requirement. The power consumption of the microprocessor in the control unit, which is constantly used to refresh the information shown is required, not taken into account.

Statistically speaking, a price change of an item is not necessary more than once a day. This means that an energy of at least 0.72 Ws is required between two item price changes. This energy requirement is multiplied many times if alphanumeric characters are to be displayed in a pixel structure with multiplex control. This fact makes it clear that there is a close connection between improving the organizational structure of a price or goods labeling device and the availability of an optimal display device for this purpose.

An important solution element is to use a display device which does not require any energy supply in order to receive the displayed information in the periods between expected changes in the displayed information, regardless of whether it is numerical, alphanumeric or graphic information. In order to preserve the image content independently of an external energy supply, visually evaluable contrast values of image cells have to be produced as an energetically stable state. At least two different contrast values are required as energetically stable states, the transition from one state to the other being achieved by the targeted addition of energy. The necessity of the energy supply in order to get from one state to the other arises from the requirement that there is no drift from one state to the other over time, and consequently the at least two energetically stable states of the image cell must have a low energy state embody.

Image cells of this type are widely known in the art, such as, for example, a leaf spring clamped on two sides with a light deflecting mirror, which can be force moves to a second stable position, or substances that change their optical properties between two states when heated and an electric field is applied.

For a technical implementation of the principle, however, it should be noted that a targeted supply of energy to increase the energy state of an image cell also requires means for a targeted supply of energy. Given the necessary high number of picture cells, this may result in a complicated structure of the means for supplying energy. This becomes clear from an example. A minimum of 16 alphanumeric characters are required to display the article name on an electronic label within a goods labeling device. The legible representation of these characters in a so-called starburst configuration (14 surface elements per character) results in a total of 224 surface elements, for which the energy e.g. must be supplied via electrical conductors. In addition there is another electrode structure e.g. for the introduction of an electric field for changing the position of the optically active molecules. Even if the conductors and electrodes are connected in a matrix, the structure is expensive and difficult to manufacture. It is cheaper if the increase in energy on all image cells at the same time, e.g. acts by heating the entire device and selectively only the direction of the change in state is initiated. However, an increase in energy through heat appears problematic when you consider that an undesirable dissipation of heat is inevitable and the already scarce energy resources are used.

A display device that optimally fulfills the object of the invention is seen in a consequent implementation of the above considerations in bringing about an increase in the energy level by introducing kinetic energy to all display volume elements that the display-related elements wear vanten surface elements. The level of this kinetic energy can remain small if these image cells are equipped with minimal volume or mass and only slight friction losses occur during their movement. An advantageous embodiment is to design these volume elements as part of a liquid column, which move in a closed channel arrangement.

The idea on which the invention is based is explained in the following description using an exemplary embodiment which is shown in more detail in the drawings.

Show it:

Fig. 1 is a front view of a known electronic label;

2 shows the mode of operation of the production of an article data combination in known electronic price labeling devices;

3 shows a front view of the electronic label according to the invention;

4 shows the mode of operation of producing an expanded article data combination in the device according to the invention

Labeling of goods;

5 shows a simple block diagram of the transmission channel between see control center and electronic label;

6 shows the structure of the data word transferred to the electronic label;

7 shows the structure of the fluidic arrangement;

8 is an enlarged view of the structure of the display area of the display device;

9 shows a diagram of the control loop in the signal converter;

10 shows the course of the communication signal;

11 a shows a cross section of the overflow channel according to FIG. 8;

11 b shows a cross section of the viewing channel according to FIG. 8;

12a shows a cross section through the micropump according to FIG. 7;

12b shows a plan view of a pump chamber;

13a shows a schematic diagram of the mixer when pump P1 is active;

13b shows a schematic diagram of the mixer when pump P2 is active; 14a shows the structural design of the electronic label in plan view;

14b the constructive structure of the electronic label in

Section A-A;

15 is a front view of a two-line electronic label acc. Fig. 3;

16 shows the structure of the device with a meander with horizontal viewing channels;

16a shows the structure of the device according to the arrangement of two meanders. Fig. 16;

16b enlarged representation of the measuring channels of the device according to

Fig. 16a;

Fig. 17 cross section acc. Fig. 16;

18 shows an enlarged representation of the device with the arrangement of an aperture in the region of the viewing channels;

19 enlarged representation acc. 18 with conical channel transitions; 20a enlarged representation of the measuring channel acc. Figures 18 and 19;

20b enlarged representation of the measuring channel acc. 18 and 19 with a modified fluid column;

Fig. 21 cross-sectional view in the area of the measuring channel acc. Fig.

20a and 20b;

Known electronic labels 1, as shown in FIG. 1, contain a numerical display device 8 on which the item price 23 is displayed with the aid of several 7-segment characters 88. The layout of the display device 8 can vary according to the actual application conditions. For example, different numbers of digits and separate numerical display areas for bulk prices are known. The use of special flags 52 for displaying information which is permanently set by masking the display device 8 is also known and supports the organization of the electronic price marking device. In the example, the electronic label 1 is supplied with power by a solar cell 17.

As shown in FIG. 2, the electronic label 1 is attached to the goods carrier 4 in the vicinity of the goods 42 to be marked. As a rule, the goods 42 are provided with an identification plate 43, which usually has at least one article number imprint 45 for uniquely identifying the goods 42 and contains a barcode 46 "article" in modern goods management systems.

In order to also change the price marking 88 when the article price 23 changes in connection with the goods management, the electronic label 1 located on the goods carrier 4 in the vicinity of the goods 42 is to be addressed. For this purpose, each electronic label 1 receives an address in connection with a setup process, which is stored in the register 82. This address is logically identical to the article number 24, so that the control center 20 can transmit a clear information to the receiving sensor 18 via the transmitting antenna 29. In the electronic label 1, the received information is fed via a reception amplifier 86 to comparison registers 83 and 85. A microprocessor 81 performs the comparison between the contents of the comparison registers 83 and 85 and, if the respective electronic label 1 is correctly addressed, changes the price label 88 if the item price information 23 is in the register

85 differs from the item price information in register 84. The Indian

Goods management 21 item price 23 assigned to item number 24 is logically mapped in register 84 in the form of an illustration A2.

The effort involved in the installation becomes clear. A reference R2 must be established between the neutral label 1 and the product 42. This takes place in such a way that the control center 20 transfers the relevant article number 24 of the goods 42 to the register 82 for the article number. Logically, a mapping A1 of the article number 23 from the goods management 21 into the register 82 of the electronic label 1 takes place the electronic label 1 must be attached to the goods carrier 4 near the goods 42, identified by the same article number 45 or the barcode 46. For the customer who would like to purchase such an excellent product 42 and thereby orientate himself on the price marking 88 on the electronic label 1, a clear relationship R1 must be established which avoids misunderstandings. With the large number of goods 42 offered and the large number of possible goods carriers 4, the reference R1 cannot always be established uniquely by means of a geometric relationship. In order to establish uniqueness of the relationship R1, a name plate 7 is generally to be arranged on the electronic label 1, which is produced by a special printer 6 and is attached to a reserved space on the electronic label 1. The content of the name plate 7 is derived from the article name 23 stored in the goods management 21. This process of printing and attaching the name badge 7 represents a further illustration A3 of a virtual image 27 of the real conditions on the goods carrier 4 with its priced goods 42 in the goods management 21.

A fundamental change in the logic of an electronic price labeling device is achieved by a type of electronic label 1, as is shown in FIG. 3. In contrast to the embodiment in FIG. 1, a display device 2 is used which is universal with regard to the image content 5 to be displayed for the goods labeling, that is to say it permits both numerical, alphanumeric and graphic information. The critical reference R1 according to FIG. 2 can thus be replaced by an automated relationship, in that the goods management 21 does not only the item price 23 but also the item name 22 is displayed on the display device 2 of the electronic label 1. In this way, a clear relationship arises for the buyer of the goods 42 between the goods 42 with the goods label 43 and the electronic one

Label 1. The set-up process of the electronic labels 1 assumes that the references R1 and R4 to be produced (see FIG. 4) for assigning the goods 42 to a specific electronic label 1 are carried out in the real sales room on the goods carrier 4. This gives the person who is responsible for the installation the best overview of the real space available on the goods carrier 4 and the optimal arrangement of the goods 42, also from a sales-promoting and aesthetic point of view. For this purpose, a mobile data acquisition device 30 is provided that establishes a reference between the distinctive ID number label 25 and the product 42 in question. This reference is stored in the registers 34 and 35 and mapped in the goods management 21. In principle, there is the possibility of extending this reference by a further reference by adding the ID number 26 of the goods carrier 4. For this purpose, the ID number of the goods carrier 26 is from the

Goods carrier ID label 41 read using the mobile data acquisition device 30, stored in the register 36 and together with the article number 24 from the register 34 and the ID number label 25 from the register 35 to the goods management 21 via the transmitter module 37 and the on mobile data acquisition device 30 located transmit antenna 38. It is expedient if the ID number 26 on the product carrier 4 is read by a product carrier ID label 41 as a barcode, similar to the article barcode 46, by the mobile data acquisition device 30 with the aid of the decoder barcode 32 and the reading head for barcode 39, to different avoid identification principles. In the same way, the ID number label 25 can also be read by applying a label ID label 10 on the electronic label 1, on which the ID number label 25 is stored in the form of a bar code. The ID number label 25 is also stored in an ID number ROM 1 1. Both numbers on the label ID label 10 and in the ID number ROM 11 are stamped unmistakably and cannot be changed in the course of the manufacturing process of the electronic label 1.

Through the illustration A4 (FIG. 4) of the reference between article number 24 of the goods 42 on the goods carrier 4 with the ID no. The article carrier 24 and the ID number label 25 in the goods management 21 are further referenced using the article number 24 with the article name 22 and the article price 23, so that a total of an article data combination 27 with five linked non-cash references is created, which is a virtual image to a certain extent the situation in the sales room. The illustration A5 in the display device 2 of the electronic label 1 serves only to inform the customer with regard to the article designation 22, article price 23 and possibly others

Issues that are displayed via special flags 52.

In contrast to the device described in FIGS. 1 and 2 with the comparison of register contents 82, 83, 84, 85 carried out there, no information processing takes place in the electronic labels 1 according to FIGS. 3 and 4.

As shown in FIG. 5, the control center 20 does so after receipt A preamplification 14 and a demodulation 15 transmitted via the antenna 29 communication signal s _a (t) with the aid of the sensor 18. The image content 5 is transmitted directly as a modulation Φ _a (t) of a signal carrier A

Gate 13 is opened when the address signals contained in the transmission signal from the control center 20 are identical to the ID number label 25, stored in the ID number ROM 11 of the relevant electronic label 1. A signal converter 16 immediately forms the communication signal s _a (t) or the image content function Φ _a (t) of the control center 20 into the flow quantity function Φ ^ t) and Φ ₂ (t), as is required for the display of the image content 5 on the display device 2. The modulation corresponds to the character of a pulse length modulation

The electronic label 1 is addressed by means of address information which is inserted at the beginning of the data stream between the control center 20 and the electronic label 1. This results in a data set structure, as shown in FIG. 6. After an address preamble 100 received for the synchronization of the demodulator 15, the label address 101 is arranged secured with a CRC control character 102. This is followed by the transmission of the synchronization preamble 103 for the channel structure of the display device 2 and then the actual image content function Φ _a (t) 104. The transmission is concluded with a switch-off signal 105.

The display device 2 only requires energy for the period of the conversion of the image content function Φ _a (t) into the flow quantity function Φ ^ t) and Φ ₂ (t), ie for the period of the transmission of the image content 5. The need for an energy supply in the event that no new image content 5 is transmitted is reduced to the energy requirement of the communication module 19.

An exemplary embodiment of a display device 2 of the type described above is described schematically in FIG. 7. Two micropumps 77 and 78 deliver two different types of fluids 56 and 57 with different colors e.g. white and black in a meandering channel arrangement 50. The two fluids 56 and 57 are brought together alternately at the mixer 70 and then pass through the inlet opening 49 into the meander 50. The meander 50 forms a grid-shaped image field 3, i.e. the image content 5 to be displayed is formed by modulating the length of one fluid 56 with respect to the other fluid 57. Contrast changes occur between the two fluids 56 and 57 in the direction of the contrast of the fluid 56 to 57 or from 57 to 56. When the image content changes, the modulated fluid types are pushed through the outlet 54 of the channel arrangement into a separator 55 in which the two fluid types are separated to the respective micropump 77 or 78. The device is energetically stable insofar as it is a closed channel arrangement in which pressure equalization takes place when the micropumps 77 and 78 are switched off and further movement of the fluids 56 and 57 is not possible.

The use of a length modulation to generate the image content 5 can also be applied to the modulation of the communication signal s _a (t) from the control center 20 onto the electronic label 1, so that, as shown in FIG. 5, a very simple structure for controlling the display Device 2 is formed, which essentially consists of a communication module 19, a signal converter 16 and image field 3. Character generators are implemented in the stationary control center 20, the flexibility of the image content 5 of the display device 2 is essentially limited by the achievable resolution of the channel density of the meander 50 and the steepness of the contrast changes and their offset between fluid 56 and fluid 57.

In order to achieve a suitable quality of the representation of the image content 5 of the display device 2, it is important that the contrast changes 56 to 57 or 57 to 56 are pushed into the meander 50 with a sufficiently precise position.

FIG. 8 shows a detailed illustration of the meander 50 under the particular aspect of the accuracy of the individual channels 51 and 53 of the meander 50 to be achieved. In the exemplary embodiment, as shown in FIGS. 11 a, 11 b and 12 a, the base body 65 a ^' 100 ^' oriented silicon wafer is used for the meander 50, in which the channel structures 51, 53 are introduced by anisotropic etching and which is covered by a glass cover layer 66. The advantage is that the channels 51 and 53 are formed using this production method can be manufactured with very high accuracy. In the exemplary embodiment, the width b _{s of} the viewing channels 51 is 0.4 mm. Due to the position of the crystal planes exposed by anisotropic etching, the area of the channel cross section of the viewing channels 51 is A "= 0.057 mm ² . The distance a _{c of} the channels 51 from center to center, on the other hand, is 0.5 mm, so that in this exemplary embodiment the resolution in the x direction is 2 lines / mm. The resolution in y-rich tion, on the other hand, results from the accuracy of the metering of the two different colored fluids 56 and 57. The resulting lengths of the two fluids 56 and 57 in the meander 50 are determined by the image content function

Φ _a (t) described, which is thus also a printout of the image content 5.

In the exemplary embodiment described, dosing accuracies of adjacent viewing channels 51 of δ <0.02 mm are achieved. The image cells 75 formed by pulse length control, from which the image content Φ _a (t) is built, are 0.4 ^* 0.5 mm ^{2 in} size with a strictly grid-like arrangement of the cells, these dimensions being the width b _{s of} the viewing channels 51 and the length I can be determined by the control software in the control unit 20. For better image quality, it is therefore also conceivable not to control the length I of the image cell 75 in multiples of the grid of the distance a _s , but analogously with variable and freely selectable length I. The accuracy δ <0.02 mm is controlled by an exactly controlled one Metering device reached as part of the signal converter 16. For this purpose, the flow velocity of the fluid 55, 56 in the meander 50 is precisely regulated in the present exemplary embodiment in order to obtain a clear relationship between the frequency of the communication signal s _a (t) and the length I of the image cells 75. The speed of the fluid 55, 56 is determined by determining the transit time t _k in a measuring channel 48 from the sensor 73 to the sensor 74 for a specific change in contrast 62 or 63 which is present between the two fluid types 55, 56. The measuring channel 48 can be identical to the first viewing channel 51 of the meander 50. The sensors 73, 74 are preferably optical sensors which can register the change in contrast 62, 63 between the two fluid types 56 and 57 on account of their spectral sensitivity. The sensors 73 and 74 are applied to the glass cover layer 66 and recognize them Contrast 94, 95. The appropriate sensor 74 is expediently arranged directly after the first viewing channel 51, the sensor 73 directly before the first viewing channel 51.

It is also appropriate that the cross section of the overflow channel 53 is smaller than the cross section of the viewing channel 51. In this way, an error δ of the image cells 75 in adjacent viewing channels 51 in the overflow channels 53 during the measurement of the synchronization contrast changes 94 and 95 for the sensor 74 is resolved to a greater extent, the control deviation thus becoming smaller overall.

If these overflow channels 53 e.g. executed with a width of 0.05 mm and one assumes a resolution of the optical sensors 73 and 74

0.125 mm, this results in a measurement error of δ <0.005 mm per viewing channel 51, which in a total of 160 viewing channels 51 can add up to 0.8 mm offset corresponding to 80 mm length of the display area in extreme cases.

This value is acceptable.

The transit times t _k determined by the sensor 74 intervene in a phase-locked loop, which is shown in FIG. 9. In order to achieve a rough synchronization of the power of the micropumps 77 and 78 to the communication signal s _a (t), the communication signal s _a (t) contains eight alternating synchronization contrast changes 94 and 95 at a time interval which, when the setpoint speed of the Fluids 56, 57 correspond to the throughput time t _k between the sensors 73 and 74. However, since the speed of the fluid 56 and 57, which due to the delivery capacity of the micropumps 77 and 78 at the beginning of the renewal process of the image content, does not match the target speed with a high degree of probability, there is a phase difference φ _a (t) of that determined at the sensor 74 Synchronization contrast change 94 or 95 with respect to the corresponding edge of the communication signal s _a (t). In the simplest case, this difference is obtained in a phase comparator 90 by multiplying the signal s _a (t) by the signal determined by the sensor 74. The phase difference signal φ _a (t) is amplified, filtered with a low-pass filter 92 and influences the amplitude of the pump control pulses p, (t). The amplitude of the pump control pulses p _{: 1} (t) or p _i2 (t) in turn influences the flow quantities Φ ^ t) or Φ ₂ (t) in such a way that the phase difference signal φ at the next synchronization contrast change 94 or 95 _a (t), which is determined from the difference between the edges of the communication signal s _a (t) with the signal s ₇₄ (t) registered by the sensor 74, has become smaller. In the manner of a phase-locked loop, the phase position between the communication signal s _a (t) and the sensor signal s ₇₄ (t) snaps into place.

Since the pump power not only one, but both micropumps 77 and 78 must be adjusted to the required flow quantities Φ ^ t) and Φ ₂ (t), the direction of the synchronization contrast change 94 or 95 is also evaluated and the amplitude of the micropump 77 or 78 influenced.

Depending on the time constant of the low-pass filter 92, the process is completed after several, for example, 8 synchronization contrast changes 94 and 95. These synchronization contrast changes 94 and 95 become after a complete change of the image content of the display device is pushed into the separator 55, so that these contrast changes used for the initial synchronization of the pumping power of the micropumps 77 and 78 are not visible.

After the startup synchronization process has been completed, the actual process takes place

Transmission of the image content function Φ _a (t) from the control center 20. This creates additional contrast changes 62 and 63 carrying the image content 5 by alternately controlling the micropumps 77 and 78.

In order to achieve for the entire duration of the signal s _(t) sufficiently accurate synchronization of the pump power, further in the communication signal s _(t) synchronization contrast changes are tung inserted 94 or 95 certain RICH, whose purpose is solely therein to ensure the function of the phase locked loop shown in FIG. 9. Together with the synchronization contrast change 94 and 95 during the synchronization process, they form a very specific, constant fundamental frequency in the

Communication signal s _(t) to which the change of the image content or image content function Φ _a (t) is locked the phase locked loop during the entire period _Λ th. These synchronization contrast changes 94 and 95, which are only required for the synchronization, are located in the overflow channels 53 (FIG. 7) after the process of changing the image content 5, which are covered with an image field cover 76 and are therefore not visible. In order to provide a corresponding control range, the volume of the overflow channels 53 corresponds exactly to two picture cells 75. If one assumes that the picture cells 75 of a viewing channel 51 are filled in 1 second in the exemplary embodiment, the permissible drift of the pump power is 1 % / sec, a value that can be realistically realized.

Since the direction of the contrast changes 94 and 95 is predefined from the synchronization frequency f _s = 1 / T _S , further so-called connection contrast changes 96, 97 must be inserted as required, depending on the color or the fluid 56 or 57 of the last one Image line 75 in the viewing channel 51 or the next image cell 75 in the subsequent viewing channel 51 follows. These connection contrast changes 96, 97 are, if they are required, when the image content 5 has been changed in the overflow channels 53 and are thus covered.

An overview of the signal profiles s _a (t) and Φ _a (t) is shown in FIG. 10.

The mode of operation of the two micropumps 77 and 78 is explained in more detail in FIGS. 12 a and b. Expediently, the micropumps 77, 78 as well as the viewing channels 51 and the overflow channels 53 are introduced into 100-oriented silicon as a common base body 65 by anisotropic etching. The inlet channels 68 and the outlet channel 69 have different dynamic flow resistances with approximately the same overall cross section. The pump chamber 67, into which the inlet channels 68 open and from which the outlet channel 69 leads, has an approximately square area. Together with the glass cover layer 66, a chamber 67 is created, on which a piezo disk 64 acts. The piezo disk 64 is permanently connected on one side to the glass cover layer 66, so that when the pump control pulses P _j (t) are applied to the electrodes of the piezo disk 64 in the manner of a bimorph, the piezo disk 64 is curved together with the glass cover layer 66. As a result, a pressure pulse is generated in the pump chamber 67. When using sawtooth-shaped pump control pulses P _j (t) for the piezo disk 64, the pressure pulse in the pumping chamber 67 is also approximately sawtooth-shaped. Due to the different geometry of the inlet channels 68 and the outlet channel 59, different ones become

At times, a transition of the laminar flow of the fluid 56, 57 into a turbulent flow is achieved, so that a resulting volume flow of the fluid 56, 57 takes place in a preferred direction over the entire sawtooth-shaped pump control pulse p _s (t). The delivery rate of the fluids 56.57 is regulated via the amplitude (the frequency would also be possible) of the pump control pulse p _s (t).

The micropumps 77, 78 used in the exemplary embodiment generate a volume output Φ., (T) and Φ ₂ (t) of 150 pl per control pulse, and 150 μl are delivered in one second. It follows from these values that a pump surge causes a height offset of an image cell 75 in the viewing channel 51 of 0.01 mm. The resolution achievable by pump pulses is therefore to be assessed as sufficiently large, considering that approximately 5 pump pulses are necessary to control an offset of 0.05 mm between image cells 75 of adjacent viewing channels 51. Another view relates to the time to change the image content 5 of the entire display device 2. For the micro pump 77.78 with the same assumed power, 1.92 min are necessary for this, a time which is sufficient for the intended application.

The nature of the micropump 77.78 described here is due to the fact that, due to the lack of statically acting valves, the micropump 77.78 at low Flow resistances of the fluid 56.57 form only a low resistance. An exact function of the alternating dosing of both fluids 56, 57 presupposes that the fluid flow through which the micropump 78 is absolutely blocked, if, for example, the micropump 77 is to deliver. The use of static valves is prohibited because of the errors to be observed. As an alternative function for static valves, two additional control loops are introduced, which are formed from the sensor 71 together with the micropump 77, as well as the sensor 72 and the micropump 78. If the micropump 77 conveys, the fluid 56, as shown in FIG. 13a, is not only pressed in the direction of the meander 50, but also in the direction of the micropump 78. In order to avoid that a large metering error occurs or even the fluid 56 into the Micropump 78 arrives, as soon as a change in contrast 62 is registered by sensor 72, micropump 78 is activated until contrast change 63 is measured at sensor 72. This results in a control oscillation at the location of the sensor 72, which is triggered by the readjustment of the micropump 78. The control vibration can be optimized by dimensioning the

Control circuit, consisting of micropump 78, sensor 72 and signal amplifiers, are kept small in a known manner, so that this control circuit operates to a certain extent like a precise static valve in the accuracy range under consideration. The reversal of the function in the event that the micropump 78 is instructed to meter the fluid 57 for the meander 50 is shown in FIG. 13 b. When switching one micropump 77, 78 to the other, a small systematic error arises, which corresponds to the channel volume of the mixer area 70. The error can be kept sufficiently small or compensated for by small cross sections of the channels or by inserting a further sensor 73. After the insertion of the two-color fluid 56, 57 into the meander 50 has been completed, the energy supply can be switched off for any length of time. The fluidic system is in an energetically stable state with constant pressure conditions at all points of the device.

If a new picture content 5 is desired, the old picture content is shifted out in the manner of a shift register by the new information. To close the circuit, it is necessary to separate the two fluids 56, 57 from one another and to supply them to separate storage containers. In the exemplary embodiment, a so-called separator 55 is used for this. The separation of both fluids 56 and 57 takes place by using a different physical property, e.g. the surface tension or the magnetic properties. In the present example, the different weights of the two fluids 56, 57 are used. The weights of both fluids differ

56 compared to 57 by approx. 10%, the two fluids are separated in a sufficiently short time, provided that the influence of the surface tension can be kept small by the geometrical dimensioning of the separator 55. The inlet 54 is then expediently in the middle of the separator 55, the outlets 59 at the highest point, the outlet 58 at the lowest point, provided that the fluid 57 is lighter than the fluid 56. Artificial gravity is generated when a fluid eg 56 is equipped with magnetic properties. The separator 55 is basically constructed in the same way, only an external magnetic field acts on the lower part a permanent magnet.

Regardless of the separation process, the process of separating the two fluids 56, 57 can be supported by two liquids that do not mix naturally, e.g. Oil and water.

The supply of fluids 56, 57 in the separator is at least twice the volume in the meander 50 and in the micropumps 77 and 78, since it must be assumed that the image content 5 can only contain one color state. The meander 50, the micropumps 77 and 78 and all the connecting channels are initially filled with the fluid 56 via the filling opening 61. The filling volume corresponds to approximately 50% of the total filling quantity of both fluids. Then fluid 57 is added until fluid emerges at the overflow 60. The presence of air pockets in the micropumps 77 and 78 as well as in the meander 50 and in the connecting channels is to be avoided because the function of the micropumps 77, 78 is severely impaired. It is advisable to initiate the filling of fluids at the branch point, mixer 50, in order to support spreading in all channel branches. After the filling process, the overflow 60 and the filling opening 61 are closed airtight.

In the design of the display device described above, an independent functional unit is now created, which can display the information to be displayed over a long period of time independently of the control by a microprocessor and a power supply. The micropumps 77, 78 are only activated if the image content 5 changes. Fig. 14 illustrates the construction of the electronic label 1. The

Base body 65 is received in a carrier part 9 together with the glass cover layer 66 and the sensors 71 to 74 attached thereon, piezo disks 64 and the solar cell 17. In the carrier part 9 there is the separator 55, which with the base body 65 has four connection points for fluids 54,

58, 59, 61. All four connection points are sealed by elastic O-rings 79. The carrier part 9 simultaneously receives the electronic plate 80, which contains all the necessary electronic components for the construction of the communication module 19 and signal converter 16 and an energy store for buffering the energy supplied by the solar cell 17.

It has already been described above that it is advantageous to design the device in multiple cells.

15 thus shows the image field 3 of the display 2 in a two-line version. This two-cell or multi-cell display can be implemented both with a single closed meander 50, in that the entire image content is exchanged in the event of a change in the image content (FIG. 16), and also the arrangement of two or more meander systems (FIGS. 16a and b) which the image content of each line can be changed individually.

This embodiment has the advantage that, if necessary, only part of the information, for example the price, is pumped out of the meander 50, while the other part of the information, for example the article name, maintains its state. For this purpose, the meanders 50 are expediently structured horizontally, with a connection to a common separator 55. Lesser amounts of energy are required for information changes, since no energy is required for the data retention of unchanged lines.

16, the horizontally arranged meander 50 is covered by a metal screen 11, the webs of which are perpendicular to the viewing channels 51 and conceal the edge region of the visible display pixels. The metal screen 117 thus contributes to improving the contrast of the information displayed. The measuring channel 127 is arranged in front of the meander and is described in more detail elsewhere.

In Fig. 16b it can be seen that the measuring channel 127 is S-shaped, so that the fluid flow from the sensors 122, 123 and 130, 131 is detected twice and the system can thus be calibrated exactly.

An embodiment example is shown in FIGS. 15 to 21, the base body 65 of which consists of a plastic. The structures for the channels and

Pump chambers are molded into the base body 65 by a special method. Channel transitions, such as the overflow channel 53 (FIG. 16), and outlets and inlets 56, 57, 54.1 to the pumping chambers 67, separator 55 and into the mixer 70 are rounded off in order to reduce the flow resistances. Changes in the cross sections of the feed channels 56; 57; 49 are conical for a gradual transition or widening (FIG. 19) and thus form the line sections 56a, 57a, 49 (FIG. 19). Constrictions are in particular at the measuring points on the mixer 70 and the s-shaped ones Measuring channels 127 provided to increase the measuring accuracy and appropriate. With the conical channel transitions 56a; 57a, in particular, the flow conditions are improved.

18 and 19, the effectiveness of the metal screen 117 for improving the contrast of the image content can be seen at the same time.

17 becomes clear. that the metal screen 117 is arranged below the meander cover, the glass cover layer 66, and allows the light emanating from the reflection film 118 to pass through such that a laminated, high-contrast display image appears on the surface of the base body 65. The separator 55 for the two fluidics 56, 57 is also located below the glass cover layer 66 and the base body 65 and is connected to the meander 50 via the opening 54.

20a and 20b, the measuring channel 127 is shown schematically and enlarged. Two sensors 122, 123 are arranged above the S-shaped measuring channel 127, which detect or measure the movement of the interfaces between the two fluids. The different physical properties of the two liquids, such as absorption capacity, electrical conductivity, magnetic properties, etc., are available for this. , on.

In the application example, the different optical density of the liquids in the visible range is used for the measuring process. The time-dependent position of the boundary layer between the two liquids is measured in order to a) the "switching" between the two liquids at the mixer 70 to control and b) the flow rate or the pumping rate of the micropumps 64; 67 for both liquids.

To detect the boundary layer, a pair of optical sensors 122, 123,

5 preferably used photodiodes with adapted spectral sensitivity. The ambient light falls through an aperture 129 onto the sensor surface 122. The type of arrangement of sensors and diaphragms is selected so that only light hits the sensors 122, 123 which has previously passed through the liquid channel 56, 57. The sensors 122, 123 are arranged one after the other in the flow direction, so that the less transparent liquid partially or completely covers the effective sensor surface of one or both sensors of a pair over time. , - The temporal change in the difference signal of the two sensors 122, 123 is evaluated in order to compensate for the fluctuating intensity of the ambient light. With the help of window discriminators, information about the position of the boundary layer relative to the sensor 122, 123 is obtained from the sensor signals. In this application example, sensor 122 serves to control 0 of the change between the two liquids. Sensor 123, in conjunction with the measuring channel 127 located above, enables the flow rate to be determined. The s-shaped channel routing under sensors 122, 123 compensates for asymmetries and adjustment errors in the real design, i.e. deviations in position of the sensors from the measuring channel do not have a detrimental effect on the measurement result.

A further advantageous, low-energy backlight is provided by a light-guiding body arranged behind the display with inclusions of fluorescent particles, which can take up the ambient light on its peripheral surfaces and let the light conduction through total reflection on the side walls exit almost without loss to special coupling-out surfaces at the desired location. The light is coupled out to the display surface through the embedded scattering bodies, for example in an STP polymer with a selected wavelength range.

The invention has been described and illustrated using selected features. Of course, the invention is not limited to this representation, but all features can be used alone or in any combination, regardless of how they are summarized in the claims.

Claims

Claims:

1. Device for displaying prices, article names and similar information on product carriers in department stores and warehouses with the aid of display devices attached to the product carriers in electronic labels, which is functionally connected to an external control center in such a way that the control center is a single electronic label address and transfer information to this electronic label can be characterized in that

- The electronic label (1) has a graphic display device (2) with energetically bistable contrast-generating image cells (75)

- In the electronic label (1) there is a receiving communication module (19) which contains a ROM (1 1) with a fixed, unique label identification number (25) and via an address comparator

(12) for comparing the label identification number (25) with the address signals (100) of the external control center (20) and via a gate (13) for releasing the modulation of the signal carrier carrying the image content (11 1) to the graphic display device (2) has

- A mobile data acquisition device (30) with a reading head for barcode (39) for reading the product identification number (26), the label identification number (25) and the article number (24) is available for setting up and with the control center (20) in Connection is established.

2. Apparatus according to claim 1, characterized in that the graphic display device (2) consists of a fluidic system with a meander (50) and at least two contrasting fluids (56,57), where in which the meander (50) contains viewing channels (51) which occupy an image field (3) in a grid pattern and which are connected to one another by covered overflow channels (53), and that at least two micropumps (77) and (78) each have one the fluids (56) or (57) alternately via a mixer

(70) and in accordance with the image content function Φ _a (t) in the meander

(50) transport.

3. Apparatus according to claim 2, characterized in that the meander (50) with its viewing channels (51) and overflow channels (53) an inlet channel (49) which is in communication with the mixer (70), and an outlet (54) has in a separator (55) in which the fluids (56, 57) are separated on the basis of different physical properties and the separator (55) has at least two outlet openings (58; 59) for the segregated fluids (56; 57) and that in each case one outlet opening (58; 59) is connected to one of the micropumps (77) or (78) via inlet channels (68) and that the micropumps (77; 78) are connected to the mixer (70) via further outlet channels (69) are, so that a closed fluidic system is present overall.

4. Apparatus according to claim 2 and 3, characterized in that the two fluids (56), (57) have different weights and that on the separator (55) has an outlet (58) for the fluid (56) and an outlet (59 ) for the fluid (57) are attached at different heights.

5. Apparatus according to claim 2 and 3, characterized in that one of the two fluids (56; 57) has magnetic properties and that the separator (55) is surrounded by a magnetic field separating the fluids (56; 57).

6. The device according to claim 2 and 3, characterized in that the

Micropumps one or more measuring channels (48) are arranged downstream, with

Sensors (71, 72, 73, 74) are connected to detect changes in contrast in the fluid flow.

7. The device according to claim 2, 3 and 6, characterized in that the

Measuring channel (48), which is the first viewing channel 51 of the meander (50) in relation to the direction of the fluid flow and the sensors (73, 74) with those on the first

View channel (51) connected overflow channels (53) are arranged.

8. The device according to claim 2, 3, 6 and 7, characterized in that the overflow channels (53) between the viewing channels (51) a smaller

Have cross section than the cross sections of the viewing channels (51).

9. The device according to claim 1 to 8, characterized in that in the

Image content function Φ _a (t) from the control center (20) to the electronic

Label (1) is transmitted as modulation of a signal carrier s _a (t), synchronization contrast changes (94.95) are inserted into the fluid stream at constant time intervals, which are provided for controlling the delivery rate of the micropumps (77, 78).

10. The device according to claim 1 to 9, characterized in that the sensors (73, 74) at the beginning and end of the measuring channel (48) are arranged, which are the synchronization contrast changes inserted in the fluid stream (94; 95) and the other Input of the phase comparator (90) with the Communication module (19) is connected, the output of the phase comparator being connected to a pump control (93) and thus a phase locked loop for synchronization between the communication signal s _a (t) sent by the control center (20) and the delivery rate of the micropumps ( 77.78).

1 1. Device according to claim 2 to 10, characterized in that the view channels (51), the overflow channels (53), the inlet channels (68) and the outlet channels (69) between the micropumps (77) and (78) with the mixer (70) is designed as a V-shaped or trapezoidal channels and that the micropumps (77) and (78) have rectangular pumping chambers (67) into which V-shaped or trapezoidal channels enter and that the base body (65) has a 100th is a silicon wafer in which the channels are introduced by anisotropic etching, and the base body (65) is covered by a cover layer (66) made of glass or silicon and that on the cover layer (66) piezo disks (64) as a drive for the pumping chambers (67) are arranged.

12. The apparatus of claim 2 to 11, characterized in that the inlet channel (68) before entering the pump chamber (67) is divided into several sub-channels, the total cross section of which is approximately equal to the cross section of the outlet channel (69), so that there are different dynamic flow resistances Set and the pump control pulses P _j (t) for the control of the piezo disk (64) on the pump chamber (67) have a steep rising edge and a less steep falling edge.

13. The apparatus according to claim 2 to 12, characterized in that the drain channels (69) between the micropumps (77,78) and the mixer (70) are in connection with sensors (71, 72) which are able to change contrast (62,63), and a counter-control of the micropumps (77,78) is present, which prevents the micropump (77) or (78) fluid (56) active for the construction of the image content 5 in the meander (50). or (57) into the inactive micropump (78) or (77).

14. Device according to claims 2 to 14, characterized in that the filling of the fluid system takes place through a special filling opening (61), an overflow (60) is present and that the fluid system is closed airtight after filling.

15. The device according to claims 2 to 15, characterized in that the filling opening (61) with the mixer (70) is in communication in order to exert a uniform filling pressure on all channel branches of the fluidic system.

16. The apparatus according to claim 1 to 3, characterized in that the

Connection between electronic label (1) and control center (20) is wireless.

17. The apparatus according to claim 1 to 3, characterized in that the

Connection between the mobile data acquisition device (30) and the control center (20) is wireless.

18. The apparatus according to claim 2, characterized in that the grafi see display device (2) consists of a fluidic system with at least two fluidics (56; 57) differing in contrast, the parallel viewing channels (51) being arranged horizontally.

19. The apparatus according to claim 18, characterized in that the meanders (50) are connected to only one common separator (55) and form a closed system.

20. The apparatus according to claim 8, characterized in that the Meßka channel (127) is S-shaped and the meander (50) is upstream and its cross section is smaller than the cross section of the viewing channels (51).

21. The apparatus according to claim 20, characterized in that in

In the area of the measuring channel (127), two sensors (122, 123) are arranged, which detect the movement of the interfaces between the various fluids and form an evaluable signal for the control of the micro pumps (67; 64).

22. The apparatus according to claim 2, 18 to 20, characterized in that the base body (65) carrying the structure consists of plastic.

23. The device according to claim 12, characterized in that the

Transitions between the overflow channels (53) and the viewing channels (51) and the transitions (56a, 57) into the mixer (70) and the inlet into the meander (50) are conical.

24. The device according to claim 2 to 22, characterized in that the viewing channels (51) of the meander (50) covered by a metal screen (117) and the webs of the metal screen (117) are arranged perpendicular to the viewing channels (51).

25. The device according to claim 2 to 23, characterized in that behind the metal screen (1 17) a reflective film (118) with fluorescent inclusions is attached as a contrast-enhancing backlight.

26. Device according to claims 2 to 23, characterized in that behind the meander (50) a light guide with scattering centers made of fluorescent material is arranged, the ambient light picked up by its edge surfaces by total reflection on its side surfaces with little loss to special, for display area forwarding outcoupling surfaces, the decoupling surfaces having embedded scattering bodies.

27. The apparatus according to claim 26, characterized in that the light guide body consists of an STP polymer.

28. Procedures for goods management in department stores and warehouses and administration of addresses of electronic labels with display devices,

which are attached to goods carriers and which are connected to a control center using the above device, characterized in that with the aid of a mobile data acquisition device (30) read in succession and stored in the registers (34), (35) and (36)

- An article number (24) which is arranged on the goods (42) on a goods identification plate (43)

- Product carrier identification numbers (26) which are arranged on at least one product carrier identification plate (41) on the product carrier

- A label identification number (25) which is arranged on the electronic label (1) on a label identification plate (10)

and that those in reference

- Article number (24)

- Product identification number (26)

- Label identification number (25)

is chained in the mobile data acquisition device (30) as an article data network (27) and that this article data network (27) is transmitted to the control center (20) and that this article data network (27) continues in the control center (20) with the article description (22) and the article price (23).

29. The method according to claim 18, characterized in that the article carrier identification number (26), the label identification number (25) and the article number (24) have the same form of an optically readable bar code by the same receiving device (28) of the Mobile data acquisition device (30) can be read. Summary:

A device and a method for displaying prices, article descriptions and similar information on product carriers in department stores and warehouses is characterized by a graphic display device which has energetically bistable picture cells and therefore only requires an energy supply when the picture content changes. By displaying the article name together with the price and further information, a simple installation of the device is made possible by reference formation between the article number of the goods to be labeled, an ID number of the electronic label and an ID number of the location of the goods on the goods carrier with that stored in a control center Item description and item price for an item data combination achieved with the help of a mobile data entry device. The display device attached to the product carrier has an image field that consists of parallel viewing channels that are connected to invisible overflow channels. At least two contrast-forming fluids are conveyed into the view channels by alternately operating micropumps in accordance with the image content to be generated, the required image quality being ensured by a phase-locked loop in which the micropumps and sensors are included.

Fig. 3