Display device with energy-efficient screen

Abstract

An electronic price and/or product display device (2), which comprises a reflective screen (21) for displaying information, and a signalling device (28) for signalling an internal state or a state change of the display device (2) by superimposing said state or state change in a visually perceptible manner directly in the viewing direction of the screen.

Claims

1. An electronic price and/or product display device (2), which comprises: a reflective screen (21) for displaying information; a signalling device (28) for signalling an internal state or an internal state change of the display device (2) by superimposing said state or state change in a visually perceptible manner in the direct view of the screen; and wherein the signalling device (28) overlays only a portion of the information displayed by means of the screen with said light signal.

2. The display device (2) according to claim 1, wherein the signalling device (28) comprises a light guide (23), which is attached or oriented with respect to the screen such that its predominant light dispersion direction extends parallel to the viewing area of the screen (21).

3. The display device (2) according to claim 2, wherein the light guide (23) forms a component of the screen (21), covering the external viewing area of the screen, or is integrated into it, or forms said external viewing area.

4. The display device (2) according to claim 1, wherein the signalling device (28) comprises one or more light sources (24), in particular LED or OLED, particularly RGB LED.

5. The display device (2) according to claim 1, wherein the light source (24) is housed inside the housing of the display device (2), wherein the light generated with it is predominantly or substantially emitted or guided parallel to the viewing area of the screen or in a direction toward the viewing area.

6. The display device (2) according to claim 4, wherein the signalling device (28) comprises a light guide (23), which is attached or oriented with respect to the screen such that its predominant light dispersion direction extends parallel to the viewing area of the screen (21) and wherein the light source (24) is optically coupled with the light guide (23) for the purpose of injecting the light generated by said light source.

7. The display device (2) according to claim 1, wherein the signalling device (28) is designed for detecting a state or a state change as a result of a radio-based or light-based or line-based communication with an external device.

8. The display device (2) according to claim 7, wherein the signalling device (28) comprises a first communication stage (12), which is designed for radio-based or light-based communication according to a time slot communication protocol or for line-bound communication, and is designed for detecting a signalling command in such communications as a trigger for signalling.

9. The display device (2) according to claim 7, wherein the signalling device (28) is designed for detecting a change in the information to be displayed by means of the screen as a trigger for signalling.

10. The display device (2) according to claim 7, wherein the signalling device (28) comprises a first communication stage (12), which is designed for radio-based or light-based communication according to a time slot communication protocol, and that the signalling device (28) is designed for autonomously detecting a communication problem, in particular a failure to synchronise with a base station (5), as a trigger for signalling.

11. The display device (2) according to claim 7, wherein the signalling device (28) comprises a second communication stage (13), which is designed for radio-based communication according to a communication protocol designed for near-field communication, in particular the standardized NFC communication protocol, and the signalling device (28) is designed for detecting a signalling command in such communication as a trigger for signalling.

12. The display device (2) according to claim 1, wherein the signalling device (28) comprises a light signal-emitting device (23, 24), which generates a visually perceptible light signal for signalling, and a light signal control device (12; 13; 20; 12, 20; 13, 20) coupled or interacting with the light signal-emitting device and controlling the same, which controls the emitting of the light signal in dependence on said state or state change.

13. The display device (2) according to claim 1, said device comprises an internal power supply, in particular realised by means of a rechargeable battery or a battery, or contacts for contacting a wired external power supply.

14. The display device (2) according to claim 1, wherein the screen (21) alone or the screen together with the signalling device (28) realises a multi-coloured display.

15. The use of the display device (2) according to claim 1 as part of a path-signage system for indicating a path, or an emergency exit signage system for displaying a path to an emergency exit.

16. An electronic price and/or product display device (2), which comprises: a reflective screen (21) for displacing information; a signalling device (28) for signalling an internal state or an internal state change of the display device (2) by superimposing said state or state change in a visually perceptible manner in the direct view of the screen; and wherein the signalling device (28) overlays the information reproduced by means of the screen with different light signals in specific zones.

17. An electronic rice and/or product display device (2) which comprises: a reflective screen (21) for displaying information; a signalling device (28) for signalling an internal state or an internal state change of the display device (2) by superimposing said state or state change in a visually perceptible manner in the direct view of the screen; and wherein the signalling device (28) completely overlays the information reproduced by means of the screen with said light signal, in particular overlaying the entire display area of the screen.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The invention is explained in more detail below with reference to the attached drawings on the basis of exemplary embodiments, although the invention is not limited to said embodiments. Identical components in the different figures are labelled with identical reference numbers. The drawings schematically show:

(2) FIG. 1 An ESL system

(3) FIG. 2 A block diagram of an ESL according to the invention

(4) FIG. 3 An ESL in a view that shows its screen completely covered by a light guide

(5) FIG. 4 A cross-section of the ESL according to FIG. 3

(6) FIG. 5 An ESL in a view that shows its light guide partially covered by another light guide

(7) FIG. 6 An ESL with several light sources for injecting different light signals into a light guide arranged in front of the screen as seen in the viewing direction

(8) FIG. 7 Three ESLs mounted on a shelf and used in an emergency exit signage system

(9) FIG. 8 A timing of the light signals for the three ESLs according to FIG. 7

DESCRIPTION OF THE EXEMPLARY EMBODIMENTS

(10) FIG. 1 shows an ESL system installed in the premises of a supermarket, hereinafter referred to as system 1, for radio communication with electronic price displays realising the display devices according to the invention, hereinafter referred to as ESL 2. Each ESL 2 comprises a display unit 19 and is attached to shelf panels 3 of a shelf 4—specifically on a front edge of the shelf 4—corresponding to products positioned on the shelf panel 3 (not shown). The ESLs 2 comprise fasteners (not shown) with which they are attached to said front edge. At this point it should be mentioned that such ESLs 2 can also be equipped with a stand, by means of which they can be placed upright on a shelf panel. Price and/or product information related to the products is displayed using the ESLs 2. The ESLs 2 are designed for communicating according to a proprietary time slot communication protocol as well as for communicating according to the standardized NFC communication protocol.

(11) The system 1 also comprises two base stations 5, wherein the right base station 5 wirelessly supplies the right shelf 4 with first radio signals FS1 and the left base station 5 wirelessly provides the left shelf 4 with second radio signals FS2. The separation into two radio signals FS1 and FS2 illustrates that the ESLs 2 mounted on the right shelf 4 communicate with the right base station 5 on a first radio channel, and the ESLs 2 mounted on the left shelf 4 communicate with the left base station 5 on a second radio channel. Thus, the ESLs 2 are grouped, which results from their previous registration with the respective base station. The proprietary time slot communication protocol is used for communicating with the ESLs 2. Therein, said price and/or product information is transmitted to the relevant ESL 2, for example, or status messages from the ESL 2 are received, e.g. regarding the screen update status.

(12) It should also be noted at this point that it is not required to separate the radio ranges of the two base stations spatially, although it is shown this way in FIG. 1 for reasons of clarity. The radio ranges can also overlap (e.g. in parts of the radio range) or be coincident.

(13) The system 1 furthermore comprises a WLAN access point, hereinafter referred to as access point 7, which covers both shelves 4 from the central location shown here. However, there may also be multiple access points 7 to provide a WLAN (wireless local area network) to the entire sales room.

(14) The system 1 also comprises portable electronic bar code readers 9 (only two shown), which the supermarket staff can use to read bar codes attached to products or the ESLs 2 in order to associate the respective ESL 2 with the appropriate product or its place on the shelf 4 in the supermarket's inventory management system. The bar code reader 9 is WLAN-enabled and is in radio contact with the access point 7 by means of a WLAN radio protocol, which is symbolised by third radio signals FS3. The bar code reader 9 also is NFC-enabled and can communicate with an ESL 2 in its immediate vicinity by means of the NFC communication protocol (see e.g. FIG. 1 at the bottom right), which is indicated by means of fourth radio signals FS4. Herein, various actions can be triggered in the respective ESL 2, or processing states can be initiated in the ESL 2, independently of the time slot communication protocol.

(15) The access point 7 and the two base stations 5 are connected via a wired network 8 to an inventory management system server 6 of the supermarket, which, among other tasks, in particular manages the information to be displayed by means of the ESLs 2 and screens of the respective ESLs 2.

(16) The ESL 2 shown in a block diagram in FIG. 2 comprises a display module 10, which has its own power supply stage 11 in the form of a battery (not shown) for generating a first supply voltage VCC1 relative to a reference potential GND.

(17) The display module 10 furthermore comprises a first communication stage 12, which is formed by means of a first communication electronic unit 15 coupled to an antenna 16 for communicating according to the time slot communication method.

(18) The display module 10 furthermore comprises a second communication stage 13, which is formed by means of a second communication electronic unit 17 coupled to a coil configuration 18 for communicating inductively according to the NFC communication protocol.

(19) The display module 10 also comprises a display stage 14, which by means of its display electronics 20 and coupled to the display unit 19 is designed for displaying said price and/or product information. The display unit 19 comprises an electrophoretic black-and-white screen 21, which is provided with first control signals 22 by the display electronics 20, in order to display the price and/or product information, for example, in a static manner and as energy-efficiently as possible.

(20) In addition, the display stage 14 comprises a signalling device 28 for signalling operating states, i.e. general states or state changes, of the ESL 2 or the system 1. A component of this signalling device 28 is a light guide 23 applied directly on the screen 21 between a viewer (not shown) of the ESL 2 and the screen 21. The light guide 23 comprises a flat-layer design and is realised as a foil in the present case, which is glued onto the screen 21. The light guide is transparent, such that the information displayed by means of the screen 21 can be read as well and as clearly as possible. Light is injected into the light guide 23 at one of its edges by means of a light source, in this case specifically an RGB light-emitting diode arrangement 24, hereinafter referred to as RGB-LED 24. Herein, the light signal-emitting device is formed by the light guide 23 and the light-emitting diode 24.

(21) The display electronics 20 provides the RGB LED 24 with a second control signal 25, e.g. to define the colour of the generated light or the duration of the respective light signal, the pulse duration of the light signal, the temporal intensity curve of the light signal, or the temporal colour gradient of the light signal. A light signal can be generated individually. However, a sequence of such light signals can also be generated. In this case, the control of the light signal-emitting device is executed autonomously by the display electronics 20 and in dependence on its states or state changes, which occur during the internal data processing or the controlling of the screen 21. Herein, the light signal control device is formed by the display electronics 20 alone.

(22) A bus system 26 connects the first communication stage 15, the display stage 14 and the second communication stage 17. Thus, data that represent, e.g., commands for controlling the respective system component 12, 13, 14 or content to be processed can be transmitted, or the status of the respective system component 12, 13, 14 can be queried.

(23) The first communication stage 12 is designed for receiving and recognizing a signalling command (as a state or state change) and for controlling the display electronics 20 via the bus system 26 as a consequence of recognizing the signalling command. Consequently, the display electronics 20 control the RGB LED 24 according to the signalling parameters transmitted by means of the signalling command, and the desired visual light signal for the viewer of the ESL 2 is emitted by means of the light guide 23. Herein, the transmission of the signalling command takes place in a communication with the base station 5 according to the time slot communication method or protocol under the control of the inventory management system server 6. The signalling command can be triggered manually by a user of the server 6 or automatically by the server 6 in response to predefined events. Herein, the light signal control device is formed by the first communication stage 12 and the display electronics 20.

(24) Likewise, said signalling command can be received and recognised via the second communication stage 13, which represents a state or a state change, such that the display electronics 20 is controlled from there via the bus system 26. Here the transmission of the signalling command is executed during a communication according to the NFC communication protocol with an NFC-enabled device, in this case one of the NFC-enabled bar code readers 9, which is associated with the operating personnel of the supermarket. The signalling command can be triggered manually by the user of the bar code reader 9. Herein, as well, an automatic or manual triggering of the signalling command can be performed by the server 6, which communicates with the bar code reader 9 by means of the access point 7, wherein the signalling command is passed from the bar code reader 9 to the ESL 2 as soon as the bar code reader 9 is in NFC communication range with the respective ESL 2.

(25) According to this exemplary embodiment, the display electronics 20 must be activated for each signalling activity, which contributes to the energy consumption. Herein, the light signal control device is formed by the second communication stage 13 and the display electronics 20.

(26) In another exemplary embodiment, both the first communication electronics 15 and/or the second communication electronics 17 can be designed for directly generating the second control signal without interconnecting the display electronics 20. In this case, it is sufficient that the first or second communication electronics 15 or, respectively, 17 is active to perform the signalling. In this case, the display electronics 20 can remain completely switched off without power consumption, for example. Herein, the light signal control device is formed by the first communication stage 12 or the second communication stage 13.

(27) However, in order to keep the operating scenarios as flexible as possible, i.e. to have a choice with regard to the timing of the electronics 15, 17 and 20 to be supplied with electricity, the exemplary embodiments described above can also be combined. In this case, it is optional whether the control signal is generated by the electronics 15, 17 or 20.

(28) However, in the case of the generation of the second control signal 25 by the second communication electronics 17, it should be noted that the second communication electronics 17 is supplied with energy via the field during the NFC communication. However, this field is no longer available for supplying energy after the completion of the NFC communication, or at the latest after the bar code reader 9 is moved out of the NFC communication area of the respective ESL 2. This means that the signalling device 28 can only generate light signals during the period of time during which the second communication stage 13 generates a second supply voltage VCC2 relative to the reference potential GND, which enables said device to operate. In this context, the light signal can serve as an indicator for the confirmation of processes or states or state changes initiated in the ESL 2 by means of the bar code reader 9. If an additional signalling is to be initiated by means of an NFC communication, it must be communicated from the second communication stage 13 to the first communication stage 12 or the display stage 14 by means of the bus system 26, such that the display module 10 implements the signalling by means of its first supply voltage VCC1 after the second supply voltage VCC2, which is generated by the field, drops out.

(29) Thus, the ESL 2 according to the invention, by considering internal states or state changes, allows for a dynamic and/or colour-related highlighting of said information reproduced by means of the screen 21, which results in increased attention by the viewer, thus placing the information into the centre of his perception. Additional positive effects include improved readability and better contrast for the information reproduced by means of the screen.

(30) It should be mentioned here in general terms that internal processing situations can also be used in addition to the command recognition of the signalling command as a state or state change, as described above. For example, the server 6 can be used to initiate an update of the information reproduced by means of the screen 21. This can be used as a state or state change for signalling. Furthermore, the completion of the update can be signalled as a separate state or state change. In general, each state or change in state can be signalled individually.

(31) FIG. 3 and FIG. 4 show mechanical and structural details of the ESL 2.

(32) In FIG. 3, the ESL 2 with its display unit 19 is shown facing the viewer of FIG. 3. The display unit 19 is received in a housing 27 of the ESL 2. The light guide 23 is arranged as the top or outermost component of the display unit 19, as indicated with angled hatches from top right to bottom left. However, hidden under the front part of the housing 27 to the right of the light guide 23, the RGB LED 24 is positioned as indicated schematically.

(33) FIG. 3 also shows a line of intersection A-A, wherein the relevant sectional representation of the ESL 2 is shown in FIG. 4.

(34) In FIG. 4, this sectional view is represented by the structure of the ESL 2. The housing 27 (shown as a dotted area in the cross-section) of the ESL 2 comprises an upward-facing recess, which allows a view of the light guide 23 and of the black-and-white screen 21, which is shown in crosshatch, through the light guide 23. The display electronics 20 are shown with slanted hatches from top left to bottom right underneath the black-and-white screen 21. This is a printed circuit board with electronic components mounted to it (not shown in detail). The RGB LED 24 is arranged next to the light guide 23, i.e. next to the black-and-white screen 21, and is electrically connected to the display electronics 20 for receiving the second control signal 25. The injection of the light signal into the light guide 23 is executed as shown schematically with the arrow 25 from the right over the outer edge of the light guide 23.

(35) FIG. 5 shows an ESL 2, in which the screen 21 is only partially covered by the light guide 23. This arrangement allows for the conventional use of the screen 21 in the uncovered area, and to overlay only certain information displayed by means of the screen 21 with said light signal in the overlap area with the light guide 23.

(36) FIG. 6 shows an ESL 2, in which the whole screen 21 is covered by the light guide 23. However, in the present case, RGB LEDs 24 are installed at three different positions under the housing wall 27. These three RGB LEDs 24 are individually controlled in a manner analogous to that discussed above. They can therefore inject light signals into the light guide 23 which are independent from each other both temporally and in terms of colour, at different respective intensities, in order to generate a light signal that changes in time as well as in colour.

(37) In the following, various operating scenarios of the ESL 2 are discussed.

(38) Using the ESL 2, colour highlights can now be realized with the help of the black-and-white screen 21, in addition to the static black-and-white reproduction of price and/or product information, such that the viewer's attention is drawn to the respective ESL 2. For example, all of the content of screen 21 visible to the viewer can be immersed in green light to indicate that the respective products, in front of which the ESL 2 is positioned, are organic products. If the respective ESL 2 is now shifted from one shelf space to another, the illumination colour of the screen 21 can easily be adjusted to the product group positioned on the new shelf space, either via the time slot communication protocol or as part of an NFC communication. For example, the colour can be changed from green to bluish if the respective ESL 2 is positioned in front of dairy products.

(39) Also, a change in price information that is imminent or has already taken place on the screen 21 of the ESL 2, which change was communicated to the respective ESL 2 by means of the base station using the time slot communication method as directed by the inventory management system server 6, can be dynamically highlighted by a screen flashing in a particular colour (for example, red). Therein, the duration of the flashing can be limited to a certain amount of time, for example, such that the ESL 2 automatically terminates its flashing activity after this time has elapsed. Also, the frequency of the flashing can be used to indicate the timeliness of the change. For example, a high flashing frequency can generate a high level of attention by the viewer and draw attention to those ESLs 2 on which the price has changed within the last hour or on which a price change is imminent, for example. The ESLs 2 flashing at a comparatively low frequency will attract less attention from the viewer. Such slow-flashing ESLs 2 can, for example, transmit the information to the viewer that a price was changed more than an hour before or that a special-offer phase for a product is nearing its end.

(40) However, the ESL 2 can also be used to display internal or system-related states, which will make it much easier for the operating personnel of a supermarket, who usually receive no or little technological training, to deal with this modern technology. For example, an ESL 2 can have an asynchronous state with respect to the rigid time grid of the time slot communication method, recognize this state on its own because it does not recognize its time slot in the active state, for example, and can then indicate this asynchronous state by means of an orange light signal overlaying the black-and-white content of screen 21, for example. If the ESL 2 does not manage to establish a synchronous state in a predefined time span of, for example, five minutes and synchronize with the base station 5 with which it is associated, the colour of the light signal may be changed to red, for example. This is a signal to the operating personnel to remove the ESL 2 from the shelf 4 and to transfer it for maintenance.

(41) However, the ESLs 2 attached to shelf panels 3 in the premises of a supermarket can also be used collectively to attract the attention of a customer. For example, the ESL system 1 can be connected to a smoke detector system that triggers a fire alarm when smoke is detected. A smoke detection can be communicated from the smoke detector system via the base stations 5 to all or a selected group of ESLs 2. The addressed ESLs 2 can then, for example, all display the letters “EMERGENCY EXIT >>>” on their black-and-white screens 21, wherein the arrows pointing to the right indicate the direction to the nearest emergency exit. At the same time, the addressed ESLs 2 can illuminate their screens 21 with a warning colour, such as red. It is also possible to illuminate the screens of the affected ESLs 2 in the green colour typically used for emergency exits. This indicating of the emergency exit by integrating the ESLs 2 into the fire alarm system also is advantageous insofar as the ESLs 2 are battery-operated and can therefore continue to display the emergency exit information including adequate light signalling despite a power outage, which typically occurs in case of fire, or if the power is shut down by the fire department, i.e. independently of an external power supply. Since each ESL 2 is provided its own battery, the ESLs 2 will continue their signalling function as emergency exit indicators even after the power is switched off or after a power failure.

(42) However, the ESLs 2 can also implement an emergency exit display as a group. For this purpose, groups of ESL 2 preferably are used which are primarily positioned at head height on the shelves, because these will be noticed at first glance by the people in the store. Another preferred group of ESLs 2 used for this purpose are those ESLs 2 positioned near the floor, as smoke and fumes first accumulate under the ceiling and then fill the room from the top down. People crawling on the ground are then guided to the emergency exit by these ESLs 2 positioned near the ground, similar to floor-level installations in airplanes.

(43) Since the inventory management server 6 is aware of the exact position of each ESL 2 in the sales room of a supermarket, and the supermarket's smoke detector system is aware of the position of the smoke detectors in the store, it is also possible for each ESL 2 or group of ESLs 2 to display the optimal (i.e. the fastest and least dangerous) escape route away from the danger zone and toward the nearest emergency exit, specific to each situation.

(44) FIG. 7 visualises a grouped use of ESLs 2 as emergency exit indicators. The three ESLs 2 attached to a shelf panel 3 are programmed via the first communication stage 12 for the purpose of indicating an emergency exit in a coordinated manner. Therein, the information to be reproduced by means of the screen 21 is the text or image “EXIT” for both the left and right ESLs 2, and the text or image “>>>” for the centre ESL 2.

(45) However, a coordinated timing of the signalling devices 28 of the three ESLs 2 is defined in the program, which timing is shown in FIG. 8. Therein, the activity “A” of each signalling device 28 is plotted over the time t. The top signal curve, which alternates between a switched-off state “0” and a switched-on state “1”, represents the light signal which during the state “1” is emitted by the ESL 2 shown on the left in FIG. 7. The centre signal curve represents the light signal which is emitted during the state “1” by the ESL 2 shown in the centre in FIG. 7. The bottom signal curve represents the light signal which is emitted during the state “1” by the ESL 2 shown on the right in FIG. 7. The light signal emitted by means of the three ESL 2 changes its position from left to right according to the text of the centre ESL 2 “>>>” and directly indicates which direction a person must take toward the emergency exit. This means that the person no longer has to comprehend the cognitively perceptible text displayed on the screen 21 in order to find the emergency exit. As shown with a dashed line in the signal sequences in FIG. 8, the switched-on state “1” can also be maintained for such a length of time that there are no dark phases between the light signals emitted by the respective ESLs 2.

(46) In closing, it must be noted again that the drawings previously described in detail only show exemplary embodiments, which can be modified by a person skilled in the arts in various ways without going beyond the scope of the invention. For the sake of completeness, it is also noted that the use of the indeterminate article “a” does not preclude the fact that the characteristics in question may also be present multiple times.