Display device having energy-saving screen, and use

Abstract

Electronic price and / or product display device (2), comprising a reflective screen (21) for displaying information, and a signalling device (28) for signalling an internal state or a change in state of the display device (2) in a visually perceptible manner directly in the direction of view onto the screen, superimposing the displayed information on the screen, characterized in that the signalling device (28) is designed to superimpose said light signal on only a part of the information displayed with the aid of the screen, or in that the signalling device (28) is designed to superimpose different light signals in certain areas on the information displayed with the aid of the screen, and in that the signalling device (28) has a light guide (23) which is mounted or arranged in such a way with respect to the screen thatis oriented so that its predominant light propagation direction runs parallel to the viewing surface of the screen (21).

Description

Technical field

[0001] The invention relates to an electronic price and / or product display device for energy-saving display of information. background

[0002] A common (price and / or product) display device, also known as an electronic price display label (ESL), or in technical jargon also called an "electronic shelf label" (ESL), features a reflective screen, electronics for controlling the screen, and a battery for power supply. The screen displays static information regarding prices and / or product-related information about a product.

[0003] Since this type of screen is generally reflective, meaning passive and non-self-illuminating, the information it displays can only be presented with sufficient contrast when adequately illuminated by external light sources, such as the artificial light in a supermarket's sales area. The artificial light illuminates the screen from the front and is reflected back to the viewer. By using an extremely energy-efficient screen and operating the electronics as efficiently as possible, considerable battery lifespans of several years can be achieved.

[0004] However, the problem with such a display device is that the screen lacks any ability to attract a heightened level of attention from a viewer, for example a casual observer.

[0005] The invention therefore has for its object to provide an improved display device in which the disadvantages mentioned above are eliminated. Summary of the invention

[0006] This object is achieved by a display device according to claim 1. The subject of the invention is therefore an electronic price and / or product display device, comprising a reflective screen for displaying information, and a signalling device for signalling an internal state or an internal state change of the display device, which is visually and perceptibly superimposed on the displayed information directly in the direction of view of the screen, characterized in that the signaling device is designed to superimpose only a part of the information displayed by means of the screen with said light signal, or in that the signaling device is designed to superimpose different light signals on the information displayed by means of the screen in certain areas, and that the signalling device has a light guide which is mounted or oriented with respect to the screen in such a way that its predominant direction of light propagation runs parallel to the viewing surface of the screen.

[0007] This object is further achieved by a use according to claim 14. The subject matter of the invention is therefore also a use of the display device according to the invention as a component of a route guidance system for displaying a route or of an emergency exit display system for displaying a route to an emergency exit.

[0008] Such a reflective screen is also known in technical jargon as an electronic paper display (EPD) and is realized using "electronic paper," or "e-paper" or "e-ink" for short. These terms essentially refer to the principle of an electrophoretic display, in which, for example, positively charged white particles and negatively charged black particles are contained in a transparent, viscous polymer. By briefly applying a voltage to electrodes between which the medium of particles and polymer is arranged, either the black particles are placed in front of the white particles, or vice versa, in the viewing direction. This arrangement then remains in place for a relatively long time (e.g., several weeks) without further energy input. By segmenting the display accordingly, letters, numbers, or images can be displayed with relatively high resolution to display the information in question.Such a reflective screen can also be realized using other technologies, such as "electrowetting" or "MEMS." As mentioned above, the screen can be configured for black-and-white, grayscale, black-white-red, or even black-white-yellow. Future developments that enable full-color or multi-color display are also included.

[0009] Such a screen is generally a reflective, i.e., passive, non-self-illuminating screen, where the relatively static information display is based on the light generated by an external (artificial or natural) light source shining onto the screen and being reflected from there to the viewer. A conventional screen, therefore, has no illuminating source of its own.

[0010] In the display device according to the invention, a light signal is additionally used for signaling. This light signal can have a constant light intensity. However, a light signal other than a static light, e.g. white light, can also be used. Such a dynamic light signal can, for example, be provided by a pulsating light signal whose brightness increases and decreases, or by a flashing light signal. In all of these variants, which elicit greater attention from the viewer and which can also be combined with one another, the light signal can be provided by white light, but is preferably provided by a light in a different color, such as red, green or blue, orange or violet, etc., because this is associated with increased attention from the viewer.

[0011] However, the pulsing of the light can also be used to save energy and / or adjust the brightness, whereby the frequency of the pulsation is selected so that the human eye cannot perceive the pulsation of the light. This allows a time-varying brightness to be achieved even with a flashing light signal.

[0012] As discussed in more detail below, a state or a change in state can be present or occur in a variety of ways in the display device. To utilize these states or changes in state for signaling, the signaling device is functionally and / or structurally divided into a light signal emitting device, which generates the visually perceptible light signal, and a light signal control device coupled to or interacting with it, which controls the emission of the light signal depending on said states or changes in state.

[0013] The light signal emitting device is, as stated, designed to physically generate the light signal in accordance with control specifications, such as control parameters or control signals or data, of the light signal control device. It therefore has at least one light source and correspondingly designed light conducting means in order to emit the light signal at the appropriate position. The statement that the emission of the light signal visually overlays the displayed information directly in the direction of view towards the screen is to be understood in such a way that the light signal is not emitted next to the screen. Rather, it is emitted spatially directly in front of the screen in the direction of view towards the screen. The light signal emitting device is, for example,arranged at least partially in front of that part of the screen which serves to display said information and is transparent at least there, so that not only the light signal is visually perceptible, but also the information displayed by means of the screen.

[0014] Furthermore, the light signal control device is designed to generate control specifications for the light signal emitting device depending on the states or state changes. Such states or state changes are the result of various internal data processing, but exclude the processing of external environmental parameters such as ambient light intensity or ambient motion detection, etc.

[0015] For this purpose, the light signal control device can be formed, for example, by parts of or by the electronics of the display device itself, which, for example, enable communication with an external base station or are responsible for controlling the screen. It now also performs additional activities related to light signal control and has direct access to the states or state changes that occur in the electronics of the display device when processing commands or parameters, etc.

[0016] However, the light signal control device can also be designed as a standalone, separate electronic unit in addition to the electronics controlling communication and / or the screen. In this case, it is coupled to the other electronic components of the display device via data signal lines, such as an interface, and is informed by these other electronic components about the presence of states or the occurrence of state changes. However, the implementation can also be chosen such that the light signal control device actively queries the other electronic components for the presence of the states or the occurrence of state changes.

[0017] Against this background, the measures according to the invention have the advantage that the display device, which according to the principle of principle displays static information, now uses the additional light signal to attract the attention of customers walking past a shelf, for example in a store. The customer walking past the shelf usually lets their gaze wander over the shelf or the products because they are looking for a specific product. During this search, the product-specific information displayed on a conventional shelf sign usually plays a subordinate or no role at all. In fact, the customer sometimes does not even notice the conventional shelf sign when looking for a specific product. However, the display device according to the invention uses its light signal to attract the attention of the viewer, who then focuses their gaze on the display device.Since the light signal is not emitted from any position or location on the housing adjacent to the display device's screen, but rather overlays it directly in the direction of view, the information displayed there, such as prices and product information, is also visually highlighted. This ensures that the customer not only perceives the display device itself with increased attention, but also focuses on the product information displayed on the screen, observes it, and thus also cognitively perceives it.

[0018] However, the display device according to the invention also supports the operating personnel of, for example, a supermarket in which such display devices are mounted on the shelves, for example as price display signs.

[0019] Conventional electronic display devices are usually centrally controlled via radio-based communication, and the various product-specific information is communicated to the individual display devices, where it is displayed on the screen. Should problems arise during the operation of such conventional display devices, or if the conventional display devices are not positioned in the intended shelf positions for whatever reason, manually searching for them has proven to be extremely problematic and, above all, very time-consuming. This is because the staff must read the information displayed on each screen and check whether it matches the shelf location where the display device is located.

[0020] The electronic display device according to the invention can, through the signaling device, in particular by emitting the light signal with predefined parameters, visually indicate that a problem exists that requires manual interaction by the operating personnel. A display device emitting this type of light signal can be removed from the relevant shelf by the operating personnel and passed on for maintenance purposes. Operating personnel can also trigger actions on-site at the affected display device by interacting with an appropriately trained service device via a radio interface in the display device to resolve the problem. The light signal makes it considerably easier to identify and search for display devices that are in a problematic condition or in the wrong place.

[0021] Further, particularly advantageous embodiments and developments of the invention emerge from the dependent claims and the following description.

[0022] The display device comprises one or more electronic assemblies or components. These can be implemented using pure hardware, an ASIC (Application Specific Integrated Circuit), or a microcontroller running software equipped with appropriate memory modules. The power or energy supply can be provided by a battery or accumulator in the display device. However, the power supply can also be wired using contacts on the display device. These contacts are connected to corresponding contacts on a shelf or, more generally, a holder for the display device in order to establish the power supply with an external supply. Communication with a base station can also be radio-based, light-based, or wired.Radio-based communication uses radio signals, light-based communication uses light signals, and wired communication uses signals on wires.

[0023] In the display device according to the invention, the signaling device can be designed to overlay said light signal on only a portion of the information displayed on the screen. This design allows individual areas of the screen to be highlighted or the signaling effect of the light signal to be limited to specific areas of the screen.

[0024] In the display device according to the invention, the signaling device can alternatively be designed to overlay the information displayed on the screen with different light signals in different areas. This design allows independent signaling to be implemented for different areas of the screen. For example, one half of the screen can emit a green flashing light signal, while the other half of the screen emits a red flashing light signal. It is also possible, for example, to set a light signal of a specific color that appears alternately in two different areas of the screen.If, for example, stripes are defined as areas, light signals can be generated that run from strip to strip, with only one strip emitting the respective light signal at a time, but switching to the adjacent strip after a certain time period. The different light signals can, in principle, have different colors and exhibit independent temporal behavior.

[0025] The signaling device can also be designed to completely overlay the information displayed on the screen, in particular the entire display area of ​​the screen, with said light signal. This design allows the signaling effect of the light signal to be extended to the entire screen, thus generating the largest possible and most intense light signal with the corresponding signaling effect.

[0026] In the display device according to the invention, for example, a lamp can be provided to generate the signaling effect of the light signal, which shines onto the screen from the front.

[0027] According to the invention, the signaling device has a light guide which is attached or oriented with respect to the screen in such a way that its predominant direction of light propagation runs parallel to the viewing surface of the screen. If light is fed into the light guide, this light is largely reflected at its edges or refracted back into the light guide. Nevertheless, a certain proportion of the light emerges from the edges of the light guide, radiates the screen from the front, i.e. directly in the direction of view towards the screen, is reflected by the screen again and exits through the light guide to the viewer. The viewer, for example the customer in a supermarket, therefore initially sees, from a distance from the electronic price display sign, primarily the light signal itself, which draws their attention to the respective price display sign.Only upon closer inspection and approaching the price display sign does the customer perceive the cognitive content of the screen intended for them, namely the information concerning products and prices. However, this information is embedded in the respective light signal. If the light signal is, for example, a constantly glowing green light, the areas surrounding the black characters (as well as the characters themselves) that represent the information also appear bathed in green light. If the light signal is, for example, a flashing green light, the areas surrounding the characters (as well as the characters themselves) appear alternately in their original black and white representation or bathed in green light.

[0028] The light guide can be a plate arranged in front of the viewing surface of the screen. However, it is preferably a film applied to the viewing surface of the screen. The viewing surface of the screen can also be curved, and the film can adapt to the curvature. In a display device according to the invention, however, the light guide can also form a component of the screen, preferably covering the outer viewing surface of the screen or being integrated into it, or forming said outer viewing surface. This makes it possible to realize particularly compact screens with a signaling function, manufacture them cost-effectively, and also to fully integrate the signaling device into the screen. The screen can thus be installed compactly in the housing of the display device.

[0029] In the display device according to the invention, the signaling device has one or more light sources, in particular LEDs or OLEDs, particularly preferably RGB LEDs, with which the light signal is generated. Implementation using a so-called RGB LED has proven particularly advantageous because it allows differently colored light signals to be generated with the lowest possible energy consumption and in the simplest way. The respectively generated colored light signals can represent or encode different states of the display device. LED stands for Light Emitting Diode, OLED for Organic LED, and RGB for red, green, and blue.

[0030] To ensure that the viewer, even a casual observer, actually focuses on the viewing surface of the screen, it has proven particularly advantageous if the light source is housed inside the housing of the display device, with the light generated preferably being emitted or directed predominantly or substantially parallel to the viewing surface of the screen or in a direction toward the viewing surface. This reliably prevents the light signal from being emitted at a location other than the viewing surface of the screen, and the viewing surface inevitably becomes the focus of the viewer's attention due to the signaling effect of the light signal.

[0031] In order to optimise the light propagation as well as the light output of the light source for signalling, it is advantageous if the light source is optically coupled to the light guide in order to feed in the light that can be generated with it. The coupling can be made, for example, from the side, from above or from below, or even diagonally. Optical coupling devices can also be used to optimise the feed in of the light. They can bundle the light generated by the light source and / or orient its propagation direction into the light guide. This can also be achieved by curving the edge of the light guide towards the light exit direction of the light source. The feed into the light guide can be point-like in a small area or linear or area-like along a larger extended area. This ensures that the predominant proportion of the light that is generated with the help of theLED is emitted into the light guide and is available there to produce the light signal that overlays the information.

[0032] The light signal is generated internally in the display device according to the invention. Various external as well as internal circumstances can serve as triggers for the light signal. In a display device according to the invention, it has therefore proven particularly advantageous for the signaling device to be designed to detect a state or a change in state as a result of radio-based, light-based, or wired communication with an external device. The internal operating state can, for example, be the updating of the information displayed on the screen, or a connection establishment or a failed connection establishment with a base station, or even a battery charge or voltage falling below a certain level as a trigger for the generation of the light signal.

[0033] It has proven particularly advantageous for the signaling device to have a first communication stage configured for radio-based or light-based communication according to a time-slot communication protocol or for wired communication, and configured to recognize a signaling command during such communication as a trigger for the signaling. With this implementation, the generation of the light signal can be remotely controlled using, for example, a central system component (merchandise management system server) of a system for controlling a plurality of such display devices, in particular electronic price display signs.

[0034] With the time-slot communication protocol, m time slots (e.g., 255 time slots) are used within n seconds (e.g., 15 seconds). The n seconds form a time-slot cycle. In this time-slot communication method, m time slots are available within a time-slot cycle for communication with the display devices. Each of the display devices can be assigned to one of the time slots, although multiple display devices can also be assigned to a specific time slot.

[0035] Such a display device can - as mentioned - have an energy storage device, such as a battery or a solar panel coupled with a rechargeable battery, for its power supply. In order to operate as energy-efficiently as possible, it has various operating states. In an active state, it has a relatively high energy consumption. The active state occurs, for example, when sending or receiving data, during screen updates, when measuring battery voltage, etc. In a sleep state, in contrast, there is relatively low energy consumption. In the sleep state, as many electronic components as possible are preferably disconnected from the power supply or switched off, or at least operated in a mode with the lowest possible energy consumption. The active state occurs predominantly in the time slot designated for the display device for communication with a base station. In the active state, the display device has, for example,It is in a receive state to receive and process commands—such as the signaling command—and, if necessary, receive data from the base station. In the active state, it can also generate transmit data and communicate it to the base station. Outside of the time slot designated for the display device, it operates primarily in the energy-saving sleep state. In the sleep state, it only performs those activities necessary for timing and timely wake-up so that it is ready to receive a synchronization data signal and / or communicate with the base station at the next designated time slot.In order to operate energy-efficiently and thus achieve the longest possible service life, the basic operating strategy is to keep the display device, which operates synchronously with the time slot communication protocol, in the sleep state for as long as possible and to operate it in the active state for the shortest possible period of time only when absolutely necessary for the purpose of data transmission with the base station.

[0036] Furthermore, it has proven particularly advantageous for the signaling device to be designed to detect a change in the information to be displayed on the screen as a trigger for the signaling. Thus, for example, the transition from a first to a second piece of information to be displayed on the screen can serve as a trigger for the generation of the light signal. The light signal control device can be a component of display electronics that serves to control the screen or can be a component of a communications stage that is designed to receive and process a command to change the information to be displayed on the screen. However, the light signal control device can also be present as a separate electronic device that is coupled to said electronic components in order to be informed about states or changes in state.

[0037] Furthermore, it has proven particularly advantageous for the signaling device to have a first communication stage configured for radio-based or light-based communication according to a time-slot communication protocol, and for the signaling device to be configured to independently detect a communication problem, in particular a lack of synchronization with a base station, as a trigger for signaling. Thus, the loss of communication capability with the base station can also serve as a triggering condition or a change in condition for generating the light signal. Here, too, the light signal control device can be a component of the first communication stage or communicatively coupled to it and configured separately.

[0038] The display device can also have a second communication stage configured for contactless communication according to a communication protocol different from the time-slot communication protocol. It can be configured for communication in a capacitive and / or inductive manner. According to a preferred embodiment, it is configured for communication according to an RFID specification (or an RFID standard), such as ISO / IEC 10536, 14443, 15693, 10373 or VDI 4470, 4472 or ISO / IEC 18000 or EPCglobal or ISO / IEC 15961, 15962 or future specifications.This not only allows for reliable communication, particularly over relatively short distances, so that pairing between the display device and a communication device designed as an RFID reader is ensured simply by the required spatial proximity of the two devices, but also the supply of electrical energy via the field used for communication (e.g., electrostatic, magnetic, electromagnetic dipole field). It has proven particularly advantageous if it is designed for communication according to an NFC specification, such as ISO / IEC 13157, 16353, 22536, 28361 or future specifications. This has the advantage that the display device can also communicate on its own in active NFC mode, i.e., in reader mode.

[0039] Furthermore, it is particularly advantageous that the signaling device has a second communication stage designed for radio-based communication according to a communication protocol designed for near-field communication, in particular the standardized NFC communication protocol, and that the signaling device is designed to recognize a signaling command during such communication as a trigger for the signaling. This allows manually initiated processes at the display device, i.e., processes initiated with a local NFC communication-capable device, as well as the completion of such a process, to be represented with the aid of the light signal. The process can, for example, be a manual reconnection process, i.e., initiated locally at the location of the display device, with a base station within whose radio range the display device was brought by operating personnel.As long as the reconnection process is pending, a flashing orange light signal can be generated, for example. If the reconnection process has been successfully completed, a light signal in the form of a green flashing light can be generated, for example, which is set after a certain period of time, e.g. one minute. The operating personnel can casually perceive this green flashing light from a distance and do not need to worry about the price display sign in question. If, on the other hand, the reconnection process has still not been successfully completed after a period of time, e.g. 10 minutes, a light signal in the form of a continuously glowing red light can be generated, for example, which does not go out on its own without further interaction with the display device. If the operating personnel perceive such a light, they must explicitly address the display device in question in order to eliminate the existing error or problem.

[0040] As already mentioned, instead of the first communication stage designed for radio-based or light-based communication, a first communication stage designed for wired communication can also be used. In this case, the display device can be coupled to contacts with conductor paths integrated into the shelf or shelf rail. Various technologies, such as I2C, SPI, UART, USB, etc., can be used to implement this configuration.

[0041] However, the display device according to the invention need not be operated exclusively as an electronic price display sign, as discussed above. Rather, it also finds advantageous use as a component of an emergency exit display system because its screen, like the signaling device, is powered independently of the power grid by means of an internal battery. For example, in the event of automatically detected smoke development, the multitude of distributed electronic price display signs can be controlled via the radio network to control the price display signs, and each can separately indicate the route to the nearest emergency exit. In the coordinated interaction of individual price display signs mounted at different positions, the route to the nearest emergency exit can also be indicated using the light signal, if necessary in combination with the information displayed on the screen.

[0042] Analogously, the ESL can also be used as part of a general wayfinding system to indicate a route.

[0043] It should also be noted that the light guide can be constructed in multiple layers. Light sources with differently colored light can be used to feed light into each layer. Here, too, the layers can overlap completely, or two or more layers can overlap individually and in segments. The feed zones for the respective light sources can also be located at different positions along the periphery of the light guide. This allows multiple areas to be illuminated simultaneously with different colors.

[0044] The respective layers - with the exception of the feed zones - can also be coated with a reflective or absorbent coating at their edges.

[0045] The display device according to the invention can have a multi-coloured screen as such, in which the signalling device can introduce additional colour aspects, or can realize a multi-coloured display together with the aid of the signalling device and the screen, which can be a pure black and white screen, for example.

[0046] These and other aspects of the invention are apparent from the figures discussed below. Short character description

[0047] The invention is explained in more detail below with reference to the accompanying figures using exemplary embodiments, to which, however, the invention is not limited. In the various figures, identical components are provided with identical reference numerals. They show schematically: Fig. 1 shows an ESL system; Fig. 2 shows a block diagram of an ESL according to the invention; Fig. 3 shows an ESL with a view of its screen completely covered by a light guide; Fig. 4 shows a cross-section through the ESL according to the Fig. 3 ; Fig. 5 an ESL with a view of its light guide partially covered by a light guide; Fig. 6 an ESL with several light sources for feeding different light signals into a light guide arranged in front of the screen in the line of sight; Fig. 7 three ESLs mounted on a shelf and used in an emergency exit display system; Fig. 8 a timing of the light signals for the three ESLs according to the Fig. 7 . Description of the embodiments

[0048] The Figure 1shows an ESL system installed in the premises of a supermarket, hereinafter referred to as System 1 for short, for radio communication with electronic price display signs, hereinafter referred to as ESL 2 for short, which implement display devices according to the invention. Each ESL 2 has a display unit 19 and is attached to shelves 3 of a shelf 4 - more precisely, to a front edge of the shelf 4 - corresponding to products (not shown) positioned on the shelf 3. The ESL 2 have fastening means (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, with the help of which they can be placed upright on a shelf. Price and / or product information for the products is displayed with the help of the ESLs 2.The ESL 2 is designed to communicate according to a proprietary time slot communication protocol as well as to communicate according to the standardized NFC communication protocol.

[0049] The system 1 also has two base stations 5, with the right base station 5 supplying the right shelf 4 with first radio signals FS1 and the left base station 5 supplying the left shelf 4 with second radio signals FS2. The division into two radio signals FS1 and FS2 illustrates that the ESLs 2 attached to the right shelf 4 communicate with the right base station 5 in a first radio channel and the ESLs 2 attached to the left shelf 4 communicate with the left base station 5 in a second radio channel. The ESLs 2 are therefore grouped together, resulting from their prior registration with the respective base station 5. The proprietary time slot communication protocol is used for communication with the ESLs 2. For example, the aforementioned price and / or product information is transmitted to the respective ESL 2 or status messages are received from the ESL 2, e.g. regarding the screen update status.

[0050] It should also be noted at this point that there does not have to be a spatial separation of the radio ranges of the two base stations 5, as is the case in the Figure 1 has been shown for reasons of clarity. The radio ranges may also overlap (e.g., in some areas) or be congruent.

[0051] System 1 also has a WLAN access point, hereinafter referred to as access point 7, which, shown centrally, provides wireless coverage for the two shelves 4. However, multiple access points 7 can also be present to provide the entire sales area with WLAN (Wireless Local Area Network).

[0052] The system 1 also has portable electronic stick code readers 9 (only two are shown), with the aid of which barcodes attached to products or the ESL 2 can be read by the supermarket staff in order to establish an association of the respective ESL 2 with the relevant product or its position on the shelf 4 in the supermarket's merchandise management system. The bar code reader 9 is WLAN-capable and is in radio contact with the access point 7 using a WLAN radio protocol, which is symbolized by third radio signals FS3. The bar code reader 9 is also NFC-capable and can communicate with an ESL 2 located in its immediate vicinity using the NFC communication protocol (see, for example, Figure 1 (bottom right), which is indicated by the fourth radio signal FS4. Various actions can be triggered or processing states initiated in the respective ESL 2, regardless of the time slot communication protocol.

[0053] The access point 7 and the two base stations 5 are connected via a wired network 8 to a merchandise management system server 6 of the supermarket, which, among other tasks, manages the information to be displayed with the help of the ESL 2 and controls the screens of the respective ESL 2.

[0054] The Figure 2 The ESL 2 shown in block diagram form has a display module 10 which has its own voltage supply stage 11 in the form of a battery (not shown) for generating a first supply voltage VCC1 relative to a reference potential GND.

[0055] The display module 10 further comprises a first communication stage 12, which is configured to communicate according to the time slot communication method by means of a first communication electronics 15 coupled to an antenna 16.

[0056] The display module 10 further comprises a second communication stage 13, which is configured with the aid of a second communication electronics 17 coupled to a coil configuration 18 for inductive communication according to the NFC communication protocol.

[0057] The display module 10 also has a display stage 14, which, with the aid of its display electronics 20 coupled to the display unit 19, is designed to display said price and / or product information. The display unit 19 has an electrophoretic black-and-white screen 21, which is supplied with first control signals 22 by the display electronics 20, for example, to display the price and / or product information in the most energy-efficient and static way possible.

[0058] In addition, the display stage 14 has a signaling device 28 for signaling operating states, i.e., generally states or changes in state, of the ESL 2 or of the system 1. One component of this signaling device 28 is a light guide 23 applied directly to the screen 21 between a viewer (not shown) of the ESL 2 and the screen 21. The light guide 23 has a flat design and, in this case, is implemented as a film that is glued to the screen 21. The light guide is transparent so that the information displayed by the screen 21 can be read as clearly and smoothly as possible. At one of the edges of the light guide 23, light is fed into the light guide 23 by means of a light source, in this case specifically an RGB light-emitting diode arrangement 24, hereinafter referred to as RGB LED 24 for short.Here, the light signal emitting device is formed by the light guide 23 and the light-emitting diode 24.

[0059] The display electronics 20 supplies the RGB LED 24 with a second control signal 25, for example, to define the color of the generated light or the duration of the respective light signal, the pulse duration of the light signal, the temporal intensity progression of the light signal, or even the temporal color progression 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 carried out autonomously by the display electronics 20 and depending on its states or state changes that occur during internal data processing or the control of the screen 21. Here, the light signal control device is formed solely by the display electronics 20.

[0060] A bus system 26 connects the first communication stage 15, the display stage 14 and the second communication stage 17. This allows data, which represent, for example, commands for controlling the respective system component 12, 13, 14 or contents to be processed, to be transmitted or the status of the respective system component 12, 13, 14 to be queried.

[0061] The first communication stage 12 is configured to receive and recognize a signaling command (as a state or state change) and, upon recognition of the signaling command, to control the display electronics 20 via the bus system 26. As a result, the display electronics 20 will control the RGB LED 24 according to the signaling parameters transmitted with the aid of the signaling command and emit the desired visual light signal for the viewer of the ESL 2 using the light guide 23. Here, the signaling command is transmitted in a communication according to the time slot communication method or protocol with the base station 5 under the control of the merchandise management system server 6. The signaling command can be triggered manually by a user of the server 6 or automatically by the server 6 in response to predefined events.Here, the light signal control device is formed by the first communication stage 12 and the display electronics 20.

[0062] Likewise, said signaling command can be received and recognized via the second communication stage 13, which represents a state or a change in state, so that the display electronics 20 is controlled from there via the bus system 26. Here, the signaling command is transmitted in a communication according to the NFC communication protocol with an NFC-enabled device, in this case one of the NFC-enabled barcode readers 9, which is assigned to the supermarket's operating staff. The signaling command can be triggered manually by the user of the barcode reader 9.Here, too, the signaling command can be triggered automatically or manually by the server 6, which communicates with the barcode reader 9 via the access point 7, from where the signaling command is passed on to the ESL 2 as soon as the barcode reader 9 is within NFC communication range with the affected ESL 2.

[0063] According to this embodiment, the display electronics 20 must be activated for each signaling activity, which contributes to energy consumption. Here, the light signal control device is formed by the second communication stage 13 and the display electronics 20.

[0064] In another embodiment, both the first communication electronics 15 and / or the second communication electronics 17 can be configured to directly generate the second control signal 25 without the interposition of the display electronics 20. In this case, it is sufficient for the first or second communication electronics 15 or 17 to be active to perform the signaling. In this case, the display electronics 20 can remain completely switched off, for example, without drawing any power. Here, the light signal control device is formed by the first communication stage 12 or the second communication stage 13.

[0065] However, in order to keep the operating scenarios as flexible as possible, i.e., to remain as flexible as possible with regard to the timing of the power-supplied electronics 15, 17, and 20, the described embodiments can also be combined. In this case, the control signal 25 can be generated optionally by either the electronics 15, 17, or 20.

[0066] However, if the second control signal 25 is generated by the second communication electronics 17, it should be noted that the second communication electronics 17 is supplied with energy by the field during NFC communication. However, this field is no longer available for energy supply after the end of NFC communication, at the latest after the barcode reader 9 is removed from an NFC communication area by the affected ESL 2. This means that the signaling device 28 can only generate light signals during the period during which the second communication stage 13 generates a second supply voltage VCC2 relative to the reference potential GND that enables operation. In this context, the light signal can serve as an indicator for confirming processes or states or state changes initiated at the ESL 2 with the aid of the barcode reader 9.If further signaling is to be started using NFC communication, this must be communicated from the second communication stage 13 to the first communication stage 12 or to the display stage 14 using the bus system 26, so that after the second supply voltage VCC2 generated by the field is lost, the display module 10 ensures signaling using its first supply voltage VCC1.

[0067] The ESL 2 according to the invention thus allows for dynamic and / or color highlighting of said information displayed on the screen 21 by taking internal states or state changes into account, which leads to increased attention on the part of the viewer and places the information at the center of their perception. Additional positive effects include improved readability and better contrast for the information displayed on the screen.

[0068] In general, it should be mentioned here that, in addition to the described command recognition of the signaling command as a state or state change, internal processing situations can also be used. For example, an update of the information displayed on screen 21 can be initiated with the help of server 6. This can be used as a state or state change for signaling. The completion of the update can also be signaled as a separate state or state change. In general, therefore, individual signaling can be used for each state or state change.

[0069] The Figure 3 and the Figure 4 show mechanical and structural details of the ESL 2.

[0070] In the Figure 3 The ESL 2 with its display unit 19 is available to the viewer of the Figure 3The display unit 19 is housed in a housing 27 of the ESL 2. The light guide 23 is arranged as the uppermost or outermost component of the display unit 19, with diagonal hatching from top right to bottom left. To the right of the light guide 23, but hidden beneath the front part of the housing 27, the RGB LED 24 is schematically positioned.

[0071] In the Figure 3 A section line AA is also shown, whereby the relevant section view of the ESL 2 is shown in the Figure 4 is shown.

[0072] In the Figure 4The aforementioned sectional view shows the structure of the ESL 2. The housing 27 (shown filled with dots in the sectional area) of the ESL 2 has an upward-facing recess, which allows a view of the light guide 23 and, through the light guide 23, of the black-and-white screen 21, which is shown in crossed hatching. Below the black-and-white screen 21, the display electronics 20 is shown with diagonal hatching from top left to bottom right. This is a circuit board with electronic components mounted on it (not shown in detail). The RGB LED 24 is arranged laterally next to the light guide 23 or the black-and-white screen 21 and is electrically connected to the display electronics 20 for receiving the second control signal 25. The light signal is fed into the light guide 23 from the right via the outer edge of the light guide 23, as schematically shown by the arrow 25.

[0073] In the Figure 5 An ESL 2 is shown in which the screen 21 is only partially covered by the light guide 23. This arrangement allows the screen 21 to be used in the uncovered area in the conventional manner and only certain information displayed by the screen 21 in the overlap area with the light guide 23 to be superimposed with said light signal.

[0074] In the Figure 6An ESL 2 is shown in which the entire screen 21 is covered with the light guide 23. However, in this 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 feed temporally and color-independent light signals, each with a different intensity, into the light guide 23, thereby generating a light signal that changes both temporally and color-wise.

[0075] The following describes the operating scenarios of the ESL 2.

[0076] With the ESL 2, in addition to the static black and white display of price and / or product information, color highlighting can now also be realized using the black and white screen 21, drawing the viewer's attention to the respective ESL 2. For example, the entire content of screen 21 visible to the viewer can be illuminated in green to indicate that the products where the ESL 2 is positioned are organic products. If the ESL 2 in question is moved from one shelf location to another, the lighting color of the screen 21 can be easily adapted to the product group positioned at the new shelf location, either via the time slot communication protocol or via NFC communication. For example, the color can be changed from green to bluish if the ESL 2 in question is positioned next to dairy products.

[0077] An impending or already completed change to price information on the screen 21 of the ESL 2, which was communicated to the relevant ESL 2 under the control of the merchandise management system server 6 with the aid of the base station 5 using the time slot communication method, can also be dynamically highlighted by a screen flashing in a specific color (e.g. red). For example, the duration of the flashing can be limited to a specific period of time so that the ESL 2 automatically stops flashing after this period of time has elapsed. The frequency of the flashing can also be used to indicate the timeliness of the change. For example, a high flashing frequency can attract the viewer's attention and draw their attention to those ESLs 2 for which, for example, the price has changed within the last hour or for which, for example, a price change is imminent.ESLs 2 that flash at a comparatively low frequency will attract less attention from the viewer. Such slow-flashing ESLs 2 can, for example, convey to the viewer the information that a price change occurred more than an hour ago or that a product offer period is nearing its end.

[0078] However, the ESL 2 can also be used to display internal states or system-relevant states, making it considerably easier for supermarket operating staff, who usually have little or no technical training, to use this modern technology. For example, an ESL 2 can exhibit an asynchronous state with respect to the rigid time frame of the time slot communication method, detect this state itself (e.g., because it does not recognize its time slot when active), and display this asynchronous state, for example, with the aid of an orange light signal overlaid on the black and white content of screen 21. Should the ESL 2 fail to establish a synchronous state and synchronize with the base station 5 to which it is assigned within a predefined period of time, for example, five minutes, the color of the light signal can be changed to red, for example.This is a sign that the operating personnel must remove the ESL 2 from shelf 4 and take it for maintenance.

[0079] However, the ESLs 2 attached to the shelves 3 in a supermarket can also be used collectively to attract a customer's attention. For example, the ESL system 1 can be connected to a smoke detector system that triggers a fire alarm upon smoke detection. 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 text "EMERGENCY EXIT >>>" on their black and white screens 21, with the right-pointing arrowheads indicating the direction to the nearest emergency exit. At the same time, the addressed ESLs 2 can illuminate their screens 21 in a warning color, such as red. It is also possible to illuminate the screens of the affected ESLs 2 in the green color typical for emergency exits.This emergency exit indication by integrating the ESL 2 into the fire alarm system is also advantageous in that the ESL 2 are battery-operated. Thus, once the emergency exit indication is initiated, they retain their emergency exit information, including adequate light signaling, regardless of a power outage that typically occurs in the event of a fire or a power shutdown by the fire department—in other words, independent of an external power supply. Since each ESL 2 is powered by its own battery, the ESL 2 will continue to signal as an emergency exit indication even after a power shutdown or power failure.

[0080] However, the ESL 2 can also be used as a group to provide emergency exit indication. The preferred groups of ESL 2 for this purpose are those ESL 2s located primarily at head height on the shelves, as these are the first thing people in the store notice. Another preferred group of ESL 2s for this purpose are those ESL 2s located near the floor, as smoke and fumes initially collect on the ceiling before filling the room from above. People crawling on the floor are then guided to the emergency exit by these ESL 2s positioned near the floor, similar to the installations in aircraft floors.

[0081] Since the merchandise management server 6 knows the exact position of each ESL 2 in the sales area of ​​a supermarket, in conjunction with the supermarket's smoke detector system, which knows the position of the smoke detectors in the store, it is also possible to display the optimized (i.e., the quickest and safest) escape route from the danger zone and towards the nearest emergency exit for each ESL 2 or a group of ESLs 2, depending on the situation.

[0082] In the Figure 7 A grouped use of ESLs 2 as an emergency exit indicator is visualized. The three ESLs 2 mounted on a shelf 3 are programmed in a coordinated manner for the purpose of emergency exit indication via the first communication level 12. The information to be displayed on the screen 21 is transmitted as the text or image "EXIT" for the left and right ESLs 2, and as the text or image ">>>" for the middle ESL 2.

[0083] However, during programming, a coordinated timing of the signaling devices 28 of the three ESL 2 is also defined, which is shown in the Figure 8 There, the activity "A" of each signaling device 28 is plotted against time t. The uppermost signal line, which switches between a switched-off state "0" and an switched-on state "1", represents the light signal generated by the Figure 7 ESL 2 shown on the left is emitted during state "1". The middle signal line represents the light signal generated by the Figure 7 ESL 2 shown in the middle is emitted during the state "1". The bottom signal line represents the light signal generated by the Figure 7ESL 2 shown on the right is emitted during state "1". The light signal emitted by the three ESL 2 changes its position from left to right according to the text of the middle ESL 2 ">>>" and immediately signals a person the direction this person must take to reach the emergency exit. The person therefore no longer has to comprehend the cognitively perceptible text displayed on the screen 21 in order to find the emergency exit. As shown in the signal sequences of the Figure 8 As shown by a broken line, the switched-on state "1" can also be maintained as long as there are no longer any dark phases between the light signals emitted by the respective ESL 2.

[0084] Finally, it should be noted once again that the figures described in detail above are merely exemplary embodiments that can be modified in a variety of ways by those skilled in the art without departing from the scope of the invention. For the sake of completeness, it should also be noted that the use of the indefinite articles "a" or "an" does not exclude the possibility that the relevant features may be present multiple times.

[0085] The invention particularly includes the following embodiments. Embodiment 1. An electronic price and / or product display device (2), comprising a reflective screen (21) for displaying information, and a signaling device (28) for signaling an internal state or an internal state change of the display device (2) that is visually and perceptibly superimposed on the displayed information directly in the direction of view of the screen. Embodiment 2. A display device (2) according to embodiment 1, wherein the signaling device (28) is designed to superimpose said light signal on only a portion of the information displayed by means of the screen. Embodiment 3. A display device (2) according to embodiment 1, wherein the signaling device (28) is designed to superimpose different light signals on the information displayed by means of the screen in certain regions. Embodiment 4.Display device (2) according to embodiment 1, wherein the signaling device (28) is designed to completely overlay the information displayed by means of the screen, in particular the entire display area of ​​the screen, with said light signal. Embodiment 5. Display device (2) according to one of the preceding embodiments, wherein the signaling device (28) comprises a light guide (23) that is mounted or oriented with respect to the screen such that its predominant light propagation direction runs parallel to the viewing surface of the screen (21). Embodiment 6. Display device (2) according to embodiment 5, wherein the light guide (23) forms a component of the screen (21), preferably covering the outer viewing surface of the screen or being integrated into it or forming said outer viewing surface. Embodiment 7.Display device (2) according to one of the preceding embodiments, wherein the signaling device (28) has one or more light sources (24), in particular LEDs or OLEDs, particularly preferably RGB LEDs. Embodiment 8. Display device (2) according to embodiment 7, wherein the light source (24) is accommodated inside the housing of the display device (2), wherein the light generated thereby is preferably emitted or guided predominantly or substantially parallel to the viewing surface of the screen or in a direction toward the viewing surface. Embodiment 9. Display device (2) according to one of embodiments 7 or 8 in combination with one of claims 5 or 6, wherein the light source (24) is optically coupled to the light guide (23) for the purpose of feeding in the light that can be generated thereby. Embodiment 10.Display device (2) according to one of the preceding embodiments, wherein the signaling device (28) is designed to detect a state or a state change as a result of radio-based, light-based, or wired communication with an external device. Embodiment 11. Display device (2) according to embodiment 10, wherein the signaling device (28) has a first communication stage (12) designed for radio-based or light-based communication according to a time-slot communication protocol or for wired communication, and is designed to recognize a signaling command during such communication as a trigger for the signaling. Embodiment 12.Display device (2) according to embodiment 10, wherein the signaling device (28) is configured to detect a change in the information to be displayed using the screen as a trigger for the signaling. Embodiment 13. Display device (2) according to embodiment 10, wherein the signaling device (28) has a first communication stage (12) configured for radio-based or light-based communication according to a time slot communication protocol, and the signaling device (28) is configured to independently detect a communication problem, in particular a lack of synchronism with a base station (5), as a trigger for the signaling. Embodiment 14.Display device (2) according to embodiment 10, wherein the signaling device (28) has 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 signaling device (28) is designed to recognize a signaling command in such a communication as a trigger for the signaling. Embodiment 15. Display device (2) according to one of the preceding embodiments, wherein the signaling device (28): a light signal emitting device (23, 24) which generates a visually perceptible light signal for the signaling, and a device coupled thereto orcooperating light signal control device (12; 13; 20; 12, 20; 13, 20) controlling the light signal emission device, which controls the emission of the light signal depending on said state or said change in state. Embodiment 16. Display device (2) according to one of the preceding embodiments, which has an internal power supply, in particular realized with the aid of an accumulator or a battery, or contacts for contacting a wired external power supply. Embodiment 17. Display device (2) according to one of the preceding embodiments, wherein the screen (21) alone or the screen together with the signaling device (28) realizes a multi-color display. Embodiment 18.Use of the display device (2) according to one of embodiments 1 to 17 as a component of a route guidance system for displaying a route or of an emergency exit display system for displaying a route to an emergency exit.

Claims

1. Electronic price and / or product display device (2), comprising - a reflective screen (21) for displaying information, and - a signaling device (28) for signaling an internal state or an internal state change of the display device (2) in a visually perceptible manner directly in the direction of view of the screen overlaying the displayed information, characterized in thatthe signalling device (28) is designed to superimpose said light signal on only a part of the information displayed by means of the screen, or that the signalling device (28) is designed to superimpose different light signals on the information displayed by means of the screen in certain areas, and that the signalling device (28) has a light guide (23) which is mounted or oriented with respect to the screen in such a way that its predominant light propagation direction runs parallel to the viewing surface of the screen (21).

2. Display device (2) according to claim 1, wherein the light guide (23) forms a component of the screen (21), preferably covering the outer viewing surface of the screen or being integrated into it or forming said outer viewing surface.

3. Display device (2) according to one of the preceding claims, wherein the signaling device (28) has one or more light sources (24), in particular LED or OLED, particularly preferably RGB-LED.

4. Display device (2) according to claim 3, wherein the light source (24) is accommodated in the interior of the housing of the display device (2), wherein the light generated thereby is preferably emitted or directed predominantly or substantially parallel to the viewing surface of the screen or in a direction towards the viewing surface.

5. Display device (2) according to one of claims 3 or 4 in combination with one of claims 1 or 2, wherein the light source (24) is optically coupled to the light guide (23) for the purpose of feeding in the light that can be generated with it.

6. Display device (2) according to one of the preceding claims, wherein the signaling device (28) is designed to detect a state or a change in state as a result of radio-based or light-based or wired communication with an external device.

7. Display device (2) according to claim 6, wherein the signaling device (28) has a first communication stage (12) which is designed for radio-based or light-based communication according to a time slot communication protocol or for wired communication, and is designed to recognize a signaling command in such a communication as a trigger for the signaling.

8. Display device (2) according to claim 6, wherein the signaling device (28) is designed to detect a change in the information to be displayed by means of the screen as a trigger for the signaling.

9. Display device (2) according to claim 6, wherein the signaling device (28) has a first communication stage (12) which is designed for radio-based or light-based communication according to a time slot communication protocol, and the signaling device (28) is designed to independently detect a communication problem, in particular a lack of synchronism with a base station (5), as a trigger for the signaling.

10. Display device (2) according to claim 6, wherein the signaling device (28) has 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 signaling device (28) is designed to recognize a signaling command in such a communication as a trigger for the signaling.

11. Display device (2) according to one of the preceding claims, wherein the signaling device (28): - a light signal emitting device (23, 24) which generates a visually perceptible light signal for signaling, and - a light signal control device (12; 13; 20; 12, 20; 13, 20) coupled thereto or cooperating therewith and controlling the light signal emitting device, which controls the emission of the light signal depending on said state or said change in state.

12. Display device (2) according to one of the preceding claims, which has an internal power supply, in particular realized with the aid of an accumulator or a battery, or contacts for contacting a wired external power supply.

13. Display device (2) according to one of the preceding claims, wherein the screen (21) alone or the screen together with the signaling device (28) realizes a multi-color display.

14. Use of the display device (2) according to one of claims 1 to 13 as a component of a route guidance system for displaying a route or of an emergency exit display system for displaying a route to an emergency exit.

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