EPD module and electronic shelf label

Abstract

According to the present application, a solar cell module, a light intensity detection module, and a display module are integrated into an integrated EPD module, and all electronic components are integrated on a TFT array and a printed circuit board (PCB). The display module integrates the solar cell module; an NFC antenna is integrated on the PCB and can replace the traditional antenna on the PCB. In the present application, an electricity usage relationship among the solar cell module, an energy storage module, and a load is managed by means of a specific charging / discharging management module and a matching charging / discharging management method, thereby achieving intelligent electricity distribution on the basis of the usage status.

Description

EPD modules and electronic price tags

[0001] Related applications

[0002] This application claims priority to the Chinese invention patent application with application number 202311650058.6 filed on December 4, 2023, and cites the entire contents disclosed in the above patent application as part of this application. Technical Field

[0003] The present application relates to the technical field of electronic price tags, and in particular to an EPD module and an electronic price tag. Background Art

[0004] An electronic price tag, also known as an electronic shelf label (ESL), is an electronic display device with information receiving and sending functions. It is mainly used as an electronic label for displaying price information in supermarkets, convenience stores, pharmacies, etc. An electronic price tag is an electronic display device placed on a shelf that can replace traditional paper price tags. Each electronic shelf label is connected to the mall's computer database via a wired or wireless network to receive the latest product information and display the latest product information on the screen on the electronic shelf label. Electronic shelf labels incorporate shelves into computer programs (specifically, electronic shelf labels remotely interact with the product identification on the shelf with the back-end product management system data. The product identification includes information such as price, category, inventory and origin). This expands the function of ordinary price tags, gets rid of the situation of manually changing price tags, and achieves price consistency between the checkout counter and the shelf.

[0005] The primary function of electronic price tags is to enable on-screen price changes and synchronize front-end and back-end information management. Key components include displays, power supplies, NFC (Near Field Communication) components, and control chips. Displays primarily use electronic ink screens / electronic paper displays (EPDs), while power supplies primarily consist of primary and secondary batteries. Furthermore, existing electronic price tags also incorporate solar cells, photosensors, and other components.

[0006] Chinese patent CN202220239095.2 proposes a solar-powered electronic price tag, comprising a rear housing with a solar panel mounted thereon. The rear housing has a wiring trough extending to its front end face, within which are wires. The solar panel is connected to a control panel via wires, which in turn is connected to a display. By incorporating solar panels, this patent addresses the technical issue of limited battery capacity affecting the lifespan of electronic price tags.

[0007] Chinese patent CN202011461029.1 proposes an electronic tag, an electronic price tag, and a control method thereof, comprising: an electronic tag body, a display unit, an illumination unit, a first acquisition unit, and a control unit disposed on the electronic tag body; the first acquisition unit is configured to acquire the light intensity of the environment in which the electronic tag body is located to obtain the current light intensity; and the control unit is configured to determine whether the current light intensity is lower than a preset light intensity, and to initiate an illumination command if the current light intensity is lower than the preset light intensity. This solution, through light intensity determination, enables the electronic tag to display the label content even in low-light conditions, thereby improving the ease of use of the electronic tag.

[0008] However, existing technologies utilize separate solar or photosensitive devices, electrically connected and integrated via printed circuit boards. This significantly limits the miniaturization, reliability, manufacturability, and cost-effectiveness of solar-powered electronic price tags. Furthermore, existing electronic price tags using secondary batteries suffer from poor charge and discharge management, lack over-discharge resistance, and suffer from poor maintainability.

[0009] Summary of the Invention

[0010] In response to the shortcomings of the existing technology, the present application provides an EPD module and electronic price tag, which solves the problems in the existing technology caused by the use of separate device integration, such as the shortcomings in miniaturization, reliability, manufacturability and low cost, as well as the low level of charge and discharge management, lack of over-discharge resistance and poor maintainability.

[0011] According to an embodiment of the present application, an EPD module includes a display component, a solar cell component, a printed circuit board, and an energy storage component;

[0012] The display assembly includes a substrate, a thin film transistor (TFT) array, an electronic paper film (FPL) and a cover plate stacked in sequence, and a driving circuit corresponding to the FPL is provided on the TFT array;

[0013] The solar cell assembly includes a solar cell, which is covered on the outer surface of the cover plate, and the area covered by the solar cell does not overlap with the display area of ​​the FPL, and the electrodes of the solar cell are electrically connected to the TFT array;

[0014] The printed circuit board is electrically connected to the TFT array, and a control circuit is provided on the printed circuit board; and

[0015] The energy storage component is used to receive energy provided by the solar cell component and output electrical energy, and is electrically connected to the printed circuit board.

[0016] This application also proposes an electronic price tag, including the above-mentioned EPD module.

[0017] Compared with the existing technology, this application has the following beneficial effects:

[0018] 1. This application is a highly integrated, all-in-one EPD module that integrates all electronic components into the TFT array and printed circuit board. There are no additional independent devices, and no additional circuit boards are required for one-to-one circuit connection and integration. This greatly improves the miniaturization of electronic price tags. At the same time, the highly integrated product also reduces the need for additional spare parts, thereby improving production efficiency and reducing cost requirements.

[0019] 2. The EPD module of this application integrates solar cell components, which can avoid the complex and unreliable electrical connection methods such as leads of separate solar cell devices in traditional light-powered electronic price tag products, thereby improving product reliability, promoting product miniaturization and low cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] FIG1 is a schematic diagram of a module architecture according to an embodiment of the present application.

[0021] FIG2 is a schematic plan view of a module according to an embodiment of the present application.

[0022] FIG3 is a plan view of a solar cell and a photosensor device according to an embodiment of the present application.

[0023] FIG4 is a plan view of the module assembly process according to an embodiment of the present application.

[0024] FIG5 a is a BB′ cross-sectional view of an embodiment of the present application.

[0025] FIG5 b is a longitudinal cross-sectional view of a conventional regional module according to an embodiment of the present application.

[0026] FIG6 a is a CC′ cross-sectional view of an embodiment of the present application.

[0027] FIG6 b is a longitudinal cross-sectional view of the solar cell region module according to an embodiment of the present application.

[0028] FIG. 7 a is a DD′ cross-sectional view of an embodiment of the present application.

[0029] FIG7 b is a longitudinal cross-sectional view of the photosensor area module according to an embodiment of the present application.

[0030] FIG8 is a schematic diagram of the charging and discharging module architecture of an embodiment of the present application.

[0031] FIG9 is a logic diagram of the charge and discharge module management process according to an embodiment of the present application.

[0032] In the above figures: Driver IC is equivalent to IC, that is, driver circuit; EPD_bus is equivalent to EPD bus; Solar is equivalent to solar cell; TFT substrate is equivalent to the whole of substrate and TFT array. DETAILED DESCRIPTION

[0033] The technical solution of this application is further described below with reference to the accompanying drawings and embodiments.

[0034] As shown in FIG1 , an embodiment of the present application proposes an EPD module, including an electronic paper screen display component, a solar cell component, a printed circuit board, and an energy storage component.

[0035] As shown in Figures 2, 3 and 4, in this embodiment, the display component includes a substrate, a thin film transistor TFT array, an electronic paper membrane FPL and a cover plate that are stacked in sequence. It should be noted that on the surface of the FPL, the central area surrounded by a border is the display area of ​​the FPL, which is used to display information such as the price on the price tag. In this embodiment, the outer side of the FPL is provided with edge sealing glue, which together with the cover plate seals the FPL on the TFT array to prevent dust and other impurities from entering the surface of the FPL or between the FPL and the TFT array, affecting the display function. In this embodiment, a cover plate made of polystyrene PS is specifically used. Optionally, the substrate can be a glass substrate or a PI flexible substrate. In this embodiment, a PI flexible substrate can be used to improve the flexibility and bending resistance of the entire product.

[0036] Printed circuit boards (PCBs) include either FPCs (Flexible Printed Circuits) or PCBs (Printed Circuit Boards), or a combination of both. In this embodiment, a flexible printed circuit (FPC) can be used to enhance product flexibility. While being flexible, the FPC can also integrally support various circuit components and integrate other electronic devices, simplifying manufacturing processes. A strip structure extends from one side of the FPC, overlapping the edge of the TFT array and providing an electrical connection. A protective adhesive is applied over the overlapping connection between the FPC and the TFT array, strengthening the connection while protecting it from external forces that could damage the connection. The strip structure is also flexible, allowing the FPC to be bent and laminated onto the outer side of the substrate. This allows the strip structure to be completely shielded by the substrate, eliminating packaging area expansion and further reducing product size. The FPC also provides protection for the flexible FPC relative to the rigid substrate. The FPC is equipped with a control circuit. In this embodiment, this control circuit includes the ESL main circuit and control circuits for other electronic components, acting as a processor (MCU) to manage circuit programming.

[0037] The TFT array is equipped with a driver circuit corresponding to the FPL, which is electrically connected to the ESL main circuit on the FPC via the EPD bus. To further enhance product integrity, the TFT array also integrates a temperature acquisition circuit and an NFC antenna, which is electrically connected to the TFT array. The integrated NFC antenna replaces the traditional independent antenna assembly connected to the PCB board, improving the performance of the related antenna and reducing costs while also reducing the size of the device.

[0038] The FPC also houses a backup NFC antenna, a radio frequency antenna, and an LED (Light Emitting Diode). The first two are electrically connected to the FPC. The NFC antenna on the FPC not only serves as a backup, but also works in conjunction with the NFC near-field coupling power supply to provide power when lighting conditions are poor or the solar cells are insufficient. The NFC and radio frequency antennas also work together to transmit signals to the central management computer, providing real-time updates of shelf information.

[0039] In this embodiment, the solar cell assembly includes solar cells, which are covered on the outer surface of the cover plate, and the area covered by the solar cells does not overlap with the display area of ​​the FPL. The solar cell materials include perovskite, organic photovoltaic (OPV), amorphous silicon, or dye-sensitized solar cell (DSSC). In this embodiment, OPV or perovskite can be used to improve its impact resistance and anti-fragmentation performance, thereby preventing damage to the solar cell coated on the outside due to accidental collisions.

[0040] At the same time, in order to improve applicability, the solar cell can be a single solar cell, or a series or parallel or series-parallel combination of multiple solar cells, so as to be selected according to various needs. In terms of shape, the solar cell can be U-shaped, square-shaped, strip-shaped, L-shaped or other structures, preferably adapted to the specific size of the solar cell and the shape of the installed substrate. As shown in Figure 3, as an option, a right-angled U-shaped structure is selected in this embodiment to match the shape of the substrate and avoid the connection area of ​​the FPC from the opening. In this embodiment, gluing, hot pressing and UV (Ultraviolet) curing are used to integrate the solar cell and the display component into one, so that it is just wrapped around the periphery of the FPL. Except for one end of the opening, it covers all positions between the boundary area of ​​the FPL and the edge of the substrate, thereby maximizing the use of the space on the substrate surface and improving the efficiency of light energy conversion.

[0041] In this embodiment, the energy storage component is a secondary battery, which can be set on an FPC or TFT. In this embodiment, it is installed on the FPC to form an integrated structure and is electrically connected to the FPC. Traditional ternary lithium-ion batteries and lithium iron phosphate batteries, etc., will experience irreversible and significant deterioration in their capacity, current output capacity, and self-discharge rate after a long period of deep over-discharge, which makes the maintainability of electronic price tag products extremely poor. Therefore, the energy storage component in this embodiment adopts a lithium titanate battery, which has the advantages of small size, resistance to over-discharge, anti-flatulence, long cycle life, high charge and discharge rate, and high safety. Lithium titanate batteries specifically include ultra-thin soft-pack lithium titanate batteries, cylindrical lithium titanate batteries, and button-type lithium titanate batteries. As an option, in this embodiment, ultra-thin soft-pack lithium titanate batteries or small-sized button-type batteries are selected to match the overall flexible structure.

[0042] Optionally, this embodiment also includes a light intensity detection component. Specifically, the light intensity detection component includes a photosensor, which is arranged in an area on the working surface of the TFT array that is not covered by the FPL; in this embodiment, it is arranged exactly on one side of the opening of the U-shaped solar cell. The light intensity detection component also includes a sampling and amplifying circuit and an AD conversion circuit arranged on the FPC. The photosensor converts ambient light into an electrical signal through photoelectric conversion, and the collected electrical signal is transmitted to the control circuit via the sampling and amplifying circuit and the AD conversion circuit. After being processed by the MCU in the ESL main circuit, the detection of light intensity is realized, thereby better cooperating with the use of the solar cell assembly. At the same time, the light intensity detection component can also be used in conjunction with the LED light through the ESL main circuit, turning on or off the light in different lighting conditions to better display the shelf information.

[0043] As shown in Figures 5a-7b, specifically regarding the circuit connection method, the solar cell directly leads out the conductive electrode through leads, flexible circuit boards, and copper foil, and is electrically connected to the TFT array through silver paste point connection, welding, crimping, and ion blasting bonding. This provides power to the drive circuit on the TFT array, and the ESL main circuit and energy storage components on the FPC are powered through the electrical connection between the TFT array and the FPC. Optionally, the FPL is electrically connected to the TFT array through a silver paste point structure and is electrically connected to the drive circuit through the TFT array. The TFT array is provided with a conductive electrode for electrically connecting to the solar cell, and this conductive electrode is electrically connected to the conductive electrode on the solar cell through silver paste points. The electrical connection through silver paste points makes the integrated module structure in this embodiment more compact and has higher reliability.

[0044] In a further specific solution, the FPL and the TFT array are simultaneously welded via two silver paste points, the two conduction electrodes on the solar cell and the conduction electrodes of the TFT array are simultaneously welded via two silver paste points, and the photosensor is welded to the TFT array via an independently set silver paste point. As shown in Figures 2, 3, and 4, the FPL and the TFT array are simultaneously welded via silver paste points 11 and 12; the conduction electrodes 21 and 22 on the solar cell and the electrode areas 21 and 22 on the TFT array (i.e., the conduction electrodes on the TFT array) are simultaneously welded via silver paste points 21 and 22; and the photosensor is welded to the electrode area 3 on the TFT array via silver paste point 3. That is, the welding of the FPL, the solar cell, and the photosensor is completed in sequence through a three-step welding method, without the need to weld each welding point in sequence, thereby improving processing efficiency and simplifying the process steps.

[0045] As shown in Figure 8, the EPD module in this embodiment also includes a charge-discharge management module. This module is integrated into the FPC and electrically connected to the solar cell assembly and / or NFC antenna, the energy storage assembly, the control circuit, and the display assembly. It can also be electrically connected to the photosensor. The solar cell assembly and / or NFC antenna convert solar energy or near-field coupling energy into electrical energy, which is then used to charge the energy storage assembly or power the load through charge-discharge management.

[0046] It should be noted that in this embodiment, the EPD module has a standby state and an operating state. The standby state is a mode in which the FPL screen does not need to refresh the displayed information, and only some electronic components require a small current to maintain operation. The operating state is a mode in which the FPL screen refreshes and displays information normally. At this time, the driver circuit is required to cooperate with the control, and the ESL main circuit on the FPC also needs to operate normally, so a large current power supply is required to support its operating state. Therefore, in this embodiment, when the EPD module is in the standby state, the solar cell provides the small current required for standby power to the TFT array, the driver circuit, the ESL main circuit on the FPC, and other electronic components, and the excess power is stored in the energy storage device. When the EPD module is in the operating state, the energy storage device outputs a large current to the various loads on the FPC and TFT array to maintain their normal operation.

[0047] As shown in FIG9 , correspondingly, the charge and discharge management method of the charge and discharge management module includes the following steps:

[0048] S1, charge and discharge working mode: allows the energy storage component to charge and discharge, and allows the solar cell and / or NFC antenna to directly power the load;

[0049] S2. When the energy storage component voltage is greater than or equal to the overcharge voltage, the overcharge protection mode is entered: the energy storage component is prohibited from charging but is allowed to output power (for example, electrical energy), and the solar cell and / or NFC antenna is allowed to directly power the load; otherwise, the overcharge protection mode is entered into the charge and discharge operation mode;

[0050] S3. When the voltage of the energy storage component is less than or equal to the over-discharge voltage, the over-discharge protection mode is entered: the energy storage component power output is disabled (for example, the energy storage component is used as a power source to output electrical energy), and the solar cell component and / or NFC antenna is allowed to charge the energy storage component using electrical energy converted from solar energy or near-field coupling energy; otherwise, the over-discharge protection mode is entered into the charge and discharge operation mode;

[0051] S4. After entering the over-discharge protection mode and the standby buffer time has elapsed, the charge and discharge management module enters the deep sleep standby state. Optionally, the standby buffer time is 0.5-2 seconds. In this embodiment, the charge and discharge management module enters the deep sleep standby state 1 second after entering the over-discharge protection mode.

[0052] S5. When the following conditions are met simultaneously: the power supplied by the solar cell module or the NFC antenna is greater than the wake-up power, and the energy storage module is not in the over-discharge protection mode, the power input triggers the wake-up, ending the deep sleep standby state;

[0053] S6. When the voltage of the energy storage component is greater than the minimum output voltage, it enters the charge and discharge working mode.

[0054] Optionally, in this embodiment, no voltage-to-current conversion device is required between the energy storage component and the load; instead, the energy storage component's power output can be achieved through circuit switching on the FPC. By controlling the maximum output voltage of the solar cell assembly or the maximum output voltage of the coupled power supply formed by the NFC antenna, the energy storage component can be charged from an external power source without a voltage-to-current conversion device, through circuit switching on the TFT array and FPC.

[0055] By using a specific charge and discharge management module and a matching charge and discharge management method to manage the power consumption relationship between solar cell components, energy storage components and loads, the power usage can be intelligently distributed. It also has reliable anti-overcharge and anti-over-discharge functions, which can effectively ensure the working status of the energy storage components, extend their service life, improve the reliability of the equipment, and facilitate management and maintenance.

[0056] This embodiment also includes an electronic price tag, comprising the aforementioned EPD module and charge-discharge management module, and employing the aforementioned charge-discharge management method. This electronic price tag product features miniaturization, high reliability, highly automated production, and low cost, while also facilitating management and maintenance.

[0057] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application and are not limiting. Although the present application has been described in detail with reference to the preferred embodiments, ordinary technicians in this field should understand that various modifications, combinations, sub-combinations and substitutions can be made to the technical solutions of the present application without departing from the purpose and scope of the technical solutions of the present application, which should all be included in the scope of the claims of the present application.

Claims

1. An EPD module, characterized in that: Including display components, solar cell components, printed circuit boards, and energy storage components; The display assembly comprises a substrate, a thin film transistor TFT array, an electronic paper film FPL and a cover plate which are stacked in sequence, and a driving circuit corresponding to the FPL is arranged on the TFT array; The solar cell assembly comprises a solar cell, the solar cell is covered on the outer surface of the cover plate, and the area covered by the solar cell does not overlap with the display area of ​​the FPL, and the electrode of the solar cell is electrically connected to the TFT array; The printed circuit board is electrically connected to the TFT array, and a control circuit is provided on the printed circuit board; and The energy storage component is used to receive energy provided by the solar cell component and output electric energy, and is electrically connected to the printed circuit board.

2. An EPD module as claimed in claim 1, characterized in that: The printed circuit board includes one of FPC and PCB or a combination of the two.

3. An EPD module as claimed in claim 1, characterized in that: An NFC antenna is also disposed on the TFT array, and the NFC antenna is electrically connected to the TFT array.

4. An EPD module as claimed in claim 1, characterized in that: The material of the solar cell comprises perovskite, or organic solar cell OPV, or amorphous silicon or dye-sensitized solar cell DSSC.

5. An EPD module as claimed in claim 1, characterized in that: The printed circuit board is also provided with a spare NFC antenna and a radio frequency antenna, both of which are electrically connected to the printed circuit board.

6. An EPD module as claimed in claim 1, characterized in that: The energy storage component includes a lithium titanate battery.

7. An EPD module as claimed in claim 1, characterized in that: The TFT array is provided with a conducting electrode for achieving electrical connection with the solar cell. The conducting electrode is electrically connected with the solar cell through silver paste dots.

8. An EPD module as claimed in claim 7, characterized in that: The solar cell is provided with two conduction electrodes, and the two conduction electrodes on the solar cell are simultaneously welded to the conduction electrode on the TFT array through silver paste points.

9. An EPD module according to any one of claims 1 to 8, characterized in that: It also includes a light intensity detection component, which includes a photosensitive sensor. The photosensitive sensor is arranged on the working surface of the TFT array in an area not covered by the FPL.

10. An EPD module as claimed in claim 9, characterized in that: The light intensity detection component also includes a sampling amplifier circuit and an AD conversion circuit arranged on a printed circuit board. The photosensor converts ambient light into an electrical signal through photoelectric conversion, and the collected electrical signal is transmitted to the control circuit via the sampling amplifier circuit and the AD conversion circuit.

11. An EPD module according to any one of claims 1 to 8, characterized in that: It also includes a charge and discharge management module, which is integrated on the printed circuit board and is electrically connected to the solar cell assembly and / or the NFC antenna, the energy storage assembly, the control circuit and the display assembly respectively; and The charging and discharging management method of the charging and discharging management module comprises the following steps: S1, charging and discharging working mode: allowing the energy storage component to charge and discharge, and allowing the solar cell and / or the NFC antenna to directly power the load; S2. When the voltage of the energy storage component is greater than or equal to the overcharge voltage, the overcharge protection mode is entered: the energy storage component is prohibited from charging but the energy storage component is allowed to output power, and the solar cell and / or the NFC antenna is allowed to directly power the load; otherwise, the overcharge protection mode is entered into the charge and discharge working mode; S3. When the voltage of the energy storage component is less than or equal to the over-discharge voltage, the over-discharge protection mode is entered: the power output of the energy storage component is prohibited, and the solar cell component and / or the NFC antenna are allowed to charge the energy storage component using the electric energy converted from solar energy or near-field coupling energy; On the contrary, it enters the charge and discharge working mode from the over-discharge protection mode; S4, after entering the over-discharge protection mode and the standby buffer time, the charge and discharge management module enters the deep sleep standby state; S5. When the following conditions are met at the same time: the power supplied by the solar cell assembly or the NFC antenna is greater than the wake-up power, and the energy storage assembly is not in the over-discharge protection mode, the power input triggers the wake-up, and the deep sleep standby state ends; and S6: When the voltage of the energy storage component is greater than the minimum output voltage, the charging and discharging working mode is entered.

12. An electronic price tag, characterized in that: An EPD module comprising any one of claims 1-11.

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