Electronic paper system

Abstract

This invention provides an electronic paper system that can reduce power consumption in an electronic paper system consisting of multiple electronic paper elements. [Solution] An electronic paper system comprising a plurality of electronic paper sheets, a battery that supplies power to the electronic paper sheets, wherein a control unit sets one of the plurality of electronic paper sheets as the master electronic paper sheet and the remaining electronic paper sheets as sub-electronic paper sheets, and in the master electronic paper sheet, the control unit controls the communication unit to acquire the image data to be displayed on all of the plurality of electronic paper sheets from the server, and controls the image signal output unit to output the image signal to the display units of all of the plurality of electronic paper sheets.

Description

Technical Field

[0001] This disclosure relates to an electronic paper system, and more particularly to an electronic paper system composed of a plurality of electronic papers.

Background Art

[0002] Conventionally, electronic paper is known as an image display device that can be rewritten multiple times and has low power consumption (see, for example, Patent Document 1). Generally, an electronic paper displays a display image based on image data acquired from an external server on a display unit. Although the power consumption during image display of electronic paper is almost zero, when changing the display content of the image, power is consumed for processes such as acquiring image data from an external server and rewriting the display image.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] As a system composed of such electronic papers, for example, an electronic paper system that arranges a plurality of electronic papers and displays a single display image on the entire large screen is known.

[0005] In such an electronic paper system, the image displayed by each electronic paper needs to obtain the one prepared for each electronic paper on the server side, or obtain a single display image to be displayed on the entire large screen from the server and cut it out according to each display area on the electronic paper side. Therefore, since each electronic paper operates independently, there is a problem that the power consumption of the system as a whole increases and the battery is consumed quickly.

[0006] This disclosure has been made in consideration of the circumstances described above, and its purpose is to provide an electronic paper system consisting of multiple electronic paper sheets that can reduce the overall power consumption of the system compared to conventional systems. [Means for solving the problem]

[0007] This disclosure provides an electronic paper system comprising a plurality of electronic paper sheets, each of which comprises a communication unit for acquiring image data from a server, a display unit for displaying an image based on the image data by rewriting the display image, an image signal output unit for outputting an image signal to the display unit for rewriting the display image, a control unit for controlling the communication unit, the display unit and the image signal output unit, and a battery for supplying power to the electronic paper, wherein the image signal output unit of each of the plurality of electronic paper sheets is capable of outputting the image signal to the display units of all of the plurality of electronic paper sheets, the control unit sets one of the plurality of electronic paper sheets as a master electronic paper and the remaining electronic paper sheets as sub-electronic paper sheets, and in the master electronic paper sheet, the control unit controls the communication unit to acquire the image data to be displayed on all of the plurality of electronic paper sheets from the server, and controls the image signal output unit to output the image signal to the display units of all of the plurality of electronic paper sheets. [Effects of the Invention]

[0008] According to this disclosure, by setting one of several electronic paper sheets as the master electronic paper and the remaining electronic paper sheets as sub-electronic paper sheets, and by having the master electronic paper sheet acquire image data from a server to be displayed on all of the electronic paper sheets, and by controlling the image signal output unit to output an image signal to the display unit of all of the electronic paper sheets, an electronic paper system consisting of multiple electronic paper sheets can be realized that can reduce the overall power consumption of the system compared to conventional systems. [Brief explanation of the drawing]

[0009] [Figure 1] This block diagram shows the schematic configuration of the electronic paper system in this disclosure. [Figure 2] Figure 1 is a block diagram illustrating the schematic configuration of an electronic paper display. [Figure 3] Figure 1 is a flowchart showing an example of the setup process for the master and sub-devices of the electronic paper display. [Figure 4] Figure 1 is a flowchart illustrating an example of the process for rewriting the displayed image of an electronic paper system. [Figure 5] This flowchart shows an example of the setup process for the master and sub of the electronic paper according to Embodiment 2 of this disclosure. [Figure 6] This is a block diagram showing the schematic configuration of the electronic paper system according to Embodiment 3 of this disclosure. [Figure 7] Figure 6 is a block diagram illustrating the schematic configuration of an electronic paper. [Figure 8] Figure 6 is a flowchart showing an example of the setup process for the master and sub-devices of an electronic paper display. [Modes for carrying out the invention]

[0010] Furthermore, preferred embodiments of this disclosure will be described.

[0011] In the electronic paper system disclosed herein, the control unit may cause the sub-electronic paper to transition to a predetermined power-saving state.

[0012] In this way, in an electronic paper system consisting of multiple electronic paper displays, the sub-electronic paper can be switched to a power-saving state, thereby realizing an electronic paper system that can reduce the overall power consumption of the system compared to conventional systems.

[0013] The electronic paper system according to this disclosure further includes a storage unit for storing the remaining battery charge, and the control unit may set the electronic paper with the largest remaining charge among the plurality of electronic papers as the master electronic paper, and set the remaining electronic papers as the sub-electronic papers.

[0014] In this way, in an electronic paper system consisting of multiple electronic paper displays, the electronic paper display with the highest remaining battery charge among the sub-electronic paper displays is set as the master electronic paper display based on the battery charge information stored in the memory unit, and the remaining electronic paper displays are set as sub-electronic paper displays. This makes it possible to realize an electronic paper system that can reduce the overall power consumption of the system compared to conventional systems.

[0015] In the electronic paper system according to this disclosure, the control unit may, when the remaining charge of the battery of the master electronic paper falls below a predetermined threshold, set the electronic paper with the largest remaining charge among the sub-electronic papers as the master electronic paper, and set the remaining electronic papers as sub-electronic papers.

[0016] By doing so, in an electronic paper system composed of a plurality of electronic papers, when the remaining amount of the battery of the master electronic paper becomes less than a predetermined threshold value, one electronic paper with the largest remaining amount among the sub - electronic papers is set as the master electronic paper, and the remaining electronic papers are set as sub - electronic papers. Therefore, an electronic paper system capable of reducing the power consumption of the entire system more than before can be realized.

[0017] In the electronic paper system according to this disclosure, the image signal output unit may output the image signal for rewriting the display image to the display unit and supply power for rewriting the display image to the display unit.

[0018] By doing so, in an electronic paper system composed of a plurality of electronic papers, the image signal output unit outputs the image signal for rewriting the display image to the display unit and supplies power for rewriting the display image to the display unit. Therefore, an electronic paper system capable of reducing the power consumption of the entire system more than before can be realized.

[0019] In the electronic paper system according to this disclosure, it further includes a hub device that relays the communication between the image signal output unit and the display unit, and the image signal output unit of each of the plurality of electronic papers may be connected to all of the plurality of electronic papers and the hub device via a cable.

[0020] By doing so, in an electronic paper system composed of a plurality of electronic papers, it further includes a hub device that relays the communication between the image signal output unit and the display unit, and the image signal output unit of each of the plurality of electronic papers is connected to all of the plurality of electronic papers and the hub device via a cable. Therefore, an electronic paper system capable of reducing the power consumption of the entire system more than before can be realized.

[0021] In the electronic paper system disclosed herein, when a large screen is formed by arranging the plurality of electronic paper displays, the system may also have a multi-display function that allows an image based on the image data received from the server to be displayed across the entire large screen.

[0022] In this way, in an electronic paper system consisting of multiple electronic paper displays, when multiple electronic paper displays are arranged to form a large screen, it is possible to realize an electronic paper system with a multi-display function that can display images based on image data received from a server across the entire large screen.

[0023] In the electronic paper system disclosed herein, the control unit of the master electronic paper may cause the communication unit to acquire the image data from the server at a predetermined timing, and display the image based on the image data across the entire large screen.

[0024] In this way, in an electronic paper system consisting of multiple electronic paper displays, the control unit causes the communication unit to acquire image data from the server at a predetermined timing, and displays the image based on the image data across the entire large screen. This makes it possible to realize an electronic paper system that can reduce the overall power consumption of the system compared to conventional systems.

[0025] In the electronic paper system according to this disclosure, the display unit includes color particles that move when a predetermined writing voltage is applied from the battery, and the control unit may display the image by causing the display unit to apply the writing voltage to the color particles based on the image data.

[0026] In this way, in an electronic paper system consisting of multiple electronic paper displays, the display unit includes color particles that move when a predetermined writing voltage is applied from the battery, and the control unit displays an image by applying a writing voltage to the color particles based on image data to the display unit. This makes it possible to realize an electronic paper system that can reduce the overall power consumption of the system compared to conventional systems.

[0027] The following details of this disclosure will be illustrated with drawings. The following description is illustrative in all respects and should not be construed as limiting the scope of this disclosure.

[0028] (Embodiment 1) <Configuration of Electronic Paper System 100> Next, an electronic paper system 100 according to Embodiment 1 of this disclosure will be described based on Figures 1 and 2. Figure 1 is a block diagram showing the schematic configuration of the electronic paper system 100 of this disclosure.

[0029] As shown in Figure 1, the electronic paper system 100 consists of multiple electronic paper displays 1 and a server 2 connected via a wireless or wired network 3. By arranging the multiple electronic paper displays 1 vertically and horizontally, a single large screen (multi-display) is formed, and display images based on image data received from the server 2 are displayed across the entire large screen.

[0030] In the electronic paper system 100, when any one electronic paper 1 is set as the master, the remaining three electronic paper 1 are set as sub-units. As shown in the example in Figure 1, of the four electronic paper 1 that make up the electronic paper system 100, the upper left electronic paper 1 (hereinafter also referred to as master electronic paper 1A) is set as the master, and the remaining three electronic paper 1 (hereinafter also referred to as sub-electronic paper 1B to 1D) are set as sub-electronic paper 1s.

[0031] Figure 2 is a block diagram showing the schematic configuration of the electronic paper 1 shown in Figure 1. As shown in Figure 2, the multiple electronic paper displays 1 that make up the electronic paper system 100 are connected to a cable 5 via a USB hub 4. In other words, the cable 5 is connected so that image data output from the image signal output unit 17 of the electronic paper displays 1 is transmitted to the display unit 111 via the USB hub 4.

[0032] Additionally, power is supplied from the master e-paper 1A to the touch panels 11 of the sub-e-papers 1B to 1D via the USB hub 4 and cable 5.

[0033] In Figure 2, the general configuration of each electronic paper 1 constituting the electronic paper system 100 is the same. Note that, due to space limitations, some of the configurations of sub-electronic papers 1C and 1D have been omitted.

[0034] The electronic paper 1 comprises a control unit 10, a touch panel 11, a timer 12, a communication unit 13, a storage unit 14, a battery 15, an image processing unit 16, and an image signal output unit 17. The following describes each component of the electronic paper 1.

[0035] The control unit 10 comprehensively controls the electronic paper 1 and consists of at least one CPU (Central Processing Unit), at least one SoC (System on a Chip), at least one RAM (Random Access Memory), at least one ROM (Read-only memory), at least one control circuit, various interface circuits, etc.

[0036] The control unit 10 monitors and controls all loads, including detection by each sensor, motor, clutch, touch panel 11, etc., in order to control the operation of the entire electronic paper 1.

[0037] Furthermore, when the control unit 10 is set as the master, it controls the touch panel 11 of the other electronic paper 1 that is set as the sub, and displays a display image based on image data received from the server 2 across the entire large screen composed of multiple electronic paper displays.

[0038] The touch panel 11 includes a display unit 111 and an operation unit 112.

[0039] The display unit 111 is the part that displays various types of information. The display unit 111 includes color particles (not shown) that move when a predetermined writing voltage is applied from the battery 15. The color particles are, for example, charged organic or inorganic particles, and a predetermined display image is displayed on the display unit 111 by performing electrophoresis, moving or rotating within a dispersion (not shown) in response to a writing voltage applied between two electrodes (not shown).

[0040] The display method of the display unit 111 is not limited to electrophoresis; for example, it may be a particle rotation method that rotates charged particles or a magnetophoresis method that moves particles using magnetism, or it may use liquid crystal or EL elements.

[0041] The control unit 112 consists of a touch panel and displays images based on image data acquired from the server 2, and receives commands from the user via the touch panel.

[0042] Timer 12 is the part that measures and counts time, and obtains the time, for example, from an internal clock or via network 3. Timer 12 is used, for example, to measure the time it takes to acquire image data from server 2.

[0043] The communication unit 13 is the part that communicates with an external server 2 via the network 3 and receives image data.

[0044] The memory unit 14 is an element or storage medium that stores information and control programs necessary to realize the various functions of the electronic paper 1. For example, semiconductor elements such as RAM and ROM, storage media such as hard disks, flash memory units, and SSDs (Solid State Drives) can be used.

[0045] Furthermore, the data may be stored in different devices, such as a hard disk drive for the data storage area and a flash memory unit for the program storage area.

[0046] The battery 15 supplies power to each part of the electronic paper 1. However, when the e-paper 1 is set to sub mode, it switches to power-saving mode, and the power supply to each part of the e-paper 1 is cut off.

[0047] The image processing unit 16 is the part that converts image data into appropriate electrical signals and processes them to make them suitable for output such as enlargement and reduction.

[0048] The image signal output unit 17 is the part that outputs the image signal to be output to the display unit 111. Furthermore, the image signal output unit 17 of the master electronic paper 1A not only outputs an image signal to its own display unit 111, but also outputs power and image signals to the display units 111 of the sub-electronic paper 1B to 1D via the USB hub 4 and cable 5.

[0049] In the example in Figure 2, the area receiving power is shown in gray. The Master Electronic Paper 1A is powered by a power supply to each component. On the other hand, the power to each part of the sub-electronic paper units 1B to 1D is cut off, except for the display unit 111. The display unit 111 of the sub-electronic paper units 1B to 1D is powered by the battery 15 of the master electronic paper unit 1A via the USB hub 4 and cable 5.

[0050] Furthermore, the power supply to the display units 111 of the sub-electronic paper 1B to 1D may be limited to only when the master electronic paper 1A is outputting an image signal for rewriting the display image. This applies not only when supplying power to the display units 111 of the sub-electronic paper 1B to 1D, but also when supplying power to the display unit 111 of the master electronic paper 1A.

[0051] <Setting up the master and sub-devices of e-paper 1> Next, the setup process for the master and sub of the electronic paper 1 will be explained based on Figure 3. Figure 3 is a flowchart showing an example of the master and sub-configuration process for the electronic paper 1 in Figure 1. In the following description, when simply referred to as "the control unit 10," it refers to the processing performed by the control unit 10 of each electronic paper 1 that constitutes the electronic paper system 100.

[0052] In step S1 of Figure 3, the control unit 10 determines whether any one of the multiple electronic paper 1 constituting the electronic paper system 100 is set as the master (step S1).

[0053] If no single electronic paper 1 is set as the master (the determination in step S1 is No), the control unit 10 returns to the determination in step S1.

[0054] On the other hand, if any one electronic paper 1 is set as the master (if the determination in step S1 is Yes), in step S2, the control unit 10 sets all other electronic paper 1 constituting the electronic paper system 100 as subs (step S2).

[0055] In the following step S3, the control unit 10 of the sub-electronic paper 1B to 1D switches the sub-electronic paper 1B to 1D to a power-saving state (step S3).

[0056] Subsequently, in step S4, the control unit 10 of the master electronic paper 1A determines whether the remaining charge of the battery 15 of the master electronic paper 1A has fallen below a predetermined threshold (step S4).

[0057] If the remaining charge of the battery 15 of the master electronic paper 1A is not below a predetermined threshold (i.e., the determination in step S4 is No), the control unit 10 returns to the determination in step S4.

[0058] On the other hand, if the remaining charge of the battery 15 of the master electronic paper 1A falls below a predetermined threshold (if the determination in step S4 is Yes), in step S5, the control unit 10 of the master electronic paper 1A restores the sub-electronic papers 1B to 1D from the power-saving state (step S5).

[0059] Specifically, the control unit 10 of the master electronic paper 1A transmits a predetermined recovery signal to the control units 10 of the sub-electronic papers 1B to 1D to recover from the power-saving state.

[0060] In the following step S6, the control unit 10 determines the electronic paper 1 with the highest remaining battery charge 15 and sets it as the master (step S6). If there are multiple electronic paper 1 with the same remaining battery charge 15, the control unit 10 may determine which electronic paper 1 to set as the master based on a predetermined order. Subsequently, the control unit 10 returns to step S2.

[0061] (Variation 1) In step S4, the determination was made whether the remaining charge of the battery 15 of the master e-paper 1A had fallen below a predetermined threshold. However, it is also possible to determine which e-paper 1 to set as the master at predetermined intervals (for example, every day) or after a predetermined number of rewrites of the displayed image.

[0062] In this way, the electronic paper 1 with the most remaining charge among the sub-electronic papers 1B to 1D is set as the master electronic paper 1A, and the remaining electronic papers 1 are set as sub-electronic papers 1B to 1D to switch to a power-saving state, thereby realizing an electronic paper system 100 that can reduce the overall power consumption of the system compared to conventional systems.

[0063] <Rewriting process for the display image of the electronic paper system 100> Next, the process of rewriting the display image of the electronic paper system 100 will be explained based on Figure 4. Figure 4 is a flowchart showing an example of the rewriting process for the display image of the electronic paper system 100 shown in Figure 1. The following explanation shows the processing of the master electronic paper 1A.

[0064] In step S11 of Figure 4, the control unit 10 determines whether or not the predetermined image data acquisition time has elapsed (step S11).

[0065] If it is not yet time to acquire image data (if the determination in step S11 is No), the control unit 10 returns to the determination in step S11.

[0066] On the other hand, when it is time to acquire image data (if the determination in step S11 is Yes), in step S12, the control unit 10 acquires image data from the server 2 (step S12).

[0067] In the following step S13, the control unit 10 determines whether or not it is necessary to rewrite the displayed image (step S13).

[0068] As a method for determining whether or not the displayed image needs to be rewritten, for example, the control unit 10 has the communication unit 13 obtain information from the server 2 regarding whether or not the displayed image needs to be rewritten, and then determines whether or not the displayed image needs to be rewritten based on that information. In this case, if the control unit 10 determines that it is necessary to rewrite the displayed image, it will have the communication unit 13 obtain image data from the server 2. On the other hand, if it determines that it is not necessary to rewrite the displayed image, it will not have the communication unit 13 obtain image data from the server 2.

[0069] Alternatively, the control unit 10 may have the communication unit 13 acquire image data from the server 2, compare it with the data of the display image currently displayed on the display unit 111 stored in the storage unit 14, and determine whether or not the display image needs to be rewritten. However, in this case, when the master and sub settings change, it is necessary to save the data of the display image currently displayed on the display unit 111 to the memory unit 14 of the electronic paper 1 that is newly set as the master.

[0070] If it is not necessary to rewrite the displayed image (if the determination in step S13 is No), the control unit 10 returns to the determination in step S11.

[0071] On the other hand, if it is necessary to rewrite the displayed image (if the determination in step S13 is Yes), in step S14, the control unit 10 causes the image signal output unit 17 to output an image signal for rewriting the displayed image of the display unit 111 (step S14).

[0072] Furthermore, in step S15, the control unit 10 causes the image signal output unit 17 to output an image signal and power for rewriting the display images of the sub-electronic paper displays 1B to 1D (step S15).

[0073] Next, in step S16, the control unit 10 determines whether or not the rewriting of the displayed image has been completed (step S16).

[0074] If the rewriting of the displayed image is not complete (if the determination in step S16 is No), the control unit 10 returns to step S14.

[0075] On the other hand, if the rewriting of the displayed image is complete (if the determination in step S16 is Yes), the control unit 10 returns to the determination in step S11.

[0076] In this way, one of the multiple electronic paper 1s is set as the master electronic paper 1A, and the remaining electronic paper 1s are set as sub-electronic paper 1B to 1D. The master electronic paper 1A acquires image data from the server 2 to be displayed on all of the multiple electronic paper 1s, and controls the image signal output unit 17 to output image signals to the display units 111 of all of the multiple electronic paper 1s, thereby realizing an electronic paper system 100 that can reduce the overall power consumption of the system compared to conventional systems.

[0077] (Embodiment 2) Next, an electronic paper system 100 relating to Actual Form 2 of this disclosure will be described based on Figure 5.

[0078] Embodiment 1 is characterized by the fact that when the remaining charge of the battery 15 of the master electronic paper 1A falls below a predetermined threshold, all sub-electronic papers 1B to 1D are restored from their power-saving state.

[0079] On the other hand, Embodiment 2 is characterized by the fact that only the sub-electronic paper 1 with the highest remaining battery charge in the battery 15 is restored and set as the master.

[0080] Since the configuration of the electronic paper system 100 and electronic paper 1 according to Embodiment 2 of this disclosure is the same as that of Embodiment 1 (Figures 1 and 2), a description will be omitted.

[0081] Figure 5 is a flowchart showing an example of the master and sub-setting process for the electronic paper 1 according to Embodiment 2 of this disclosure. The rewriting process for the display image of the electronic paper system 100 is the same as in Embodiment 1 (Figure 4), so its explanation is omitted.

[0082] The processes in steps S21, S22, S24, and S25 in Figure 5 are the same as steps S1 to S4 in Figure 3 (Embodiment 1), respectively, so their explanation is omitted. Here, we will explain the processes in steps S23 and S26-S29 of Figure 5, which are not shown in Figure 3.

[0083] In the following explanation, it will be assumed that among the sub-electronic paper 1B to 1D, the battery 15 of sub-electronic paper 1B has the highest remaining charge.

[0084] In step S22 of Figure 5, after setting all other electronic paper 1 constituting the electronic paper system 100 as sub-electronic paper (step S22), in step S23, the control unit 10 stores the remaining battery capacity 15 of the sub-electronic paper 1B to 1D in the storage unit 14 (step S23).

[0085] Next, in step S25, if the remaining charge of the battery 15 of the master electronic paper 1A falls below a predetermined threshold (if the determination in step S25 is Yes), in step S26, the control unit 10 of the master electronic paper 1A transmits a predetermined recovery signal to the control unit 10 of the sub-electronic paper 1B, which has the largest remaining charge of the battery 15, to recover from the power-saving state (step S26).

[0086] Next, in step S27, the sub-electronic paper 1B, which has recovered from the power-saving state, sets itself as the master (step S27).

[0087] Next, in step S28, the sub-electronic paper 1B stores the remaining battery level of the master electronic paper 1A in the storage unit 14 (step S28).

[0088] Next, in step S29, the control unit 10 of the master electronic paper 1A sets itself to sub-unit and switches to a power-saving state (step S29). Subsequently, the control unit 10 returns to the determination in step S25.

[0089] In this way, based on the remaining battery charge information of the battery 15 stored in the memory unit 14, only the electronic paper 1B with the highest remaining charge among the sub-electronic paper 1B to 1D is restored from the power-saving state and set as the master, while the master electronic paper 1A stores the remaining battery charge of the battery 15 in the memory unit 14, is set as a sub, and then switches to the power-saving state. As a result, an electronic paper system 100 can be realized that can reduce the overall power consumption of the system compared to conventional systems.

[0090] (Embodiment 3) Next, an electronic paper system 100 relating to Actual Form 3 of this disclosure will be described based on Figures 6 and 8.

[0091] Embodiment 1 is characterized by determining which electronic paper 1 to set as the master when the remaining charge of the battery 15 of the master electronic paper 1A falls below a predetermined threshold.

[0092] On the other hand, Embodiment 3 is characterized in that, in addition to determining when the remaining charge of the battery 15 of the master electronic paper 1A falls below a predetermined threshold, the electronic paper 1 to be set as the master is also determined when the battery 15 of the electronic paper 1 is replaced. If the battery 15 is replaced, setting the e-paper 1 with the fully charged battery 15 as the master will improve the overall battery life of the system.

[0093] Figure 6 is a block diagram showing the schematic configuration of the electronic paper system 100 according to Embodiment 3 of this disclosure. As shown in Figure 6, when a user touches any of the e-paper displays 1D, icons indicating the remaining battery level 15 of each e-paper display 1 are displayed.

[0094] Figure 7 is a block diagram showing the schematic configuration of the electronic paper 1 in Figure 6. In Figure 7, the control unit 10 is assumed to be equipped with a circuit that can detect whether or not the battery 15 has been replaced based on changes in voltage, etc. The other components in Figure 7 are the same as those in Embodiment 1 (Figure 2), so their descriptions are omitted.

[0095] The difference from Embodiment 1 is that the sub-electronic paper 1B to 1D are powered not only to the display unit 111 but to the entire touch panel 11.

[0096] Figure 8 is a flowchart showing an example of the master and sub-setting process for the electronic paper 1 in Figure 6. The rewriting process for the display image of the electronic paper system 100 is the same as in Embodiment 1 (Figure 4), so the explanation is omitted.

[0097] The processes in steps S31-S33 and S37-S39 in Figure 8 are the same as steps S1-S6 in Figure 3 (Embodiment 1), so their explanation is omitted. Here, we will explain the processes in steps S34 to S36 of Figure 8, which are not shown in Figure 3.

[0098] In step S33 of Figure 8, after the sub-electronic paper displays 1B to 1D are switched to a power-saving state (step S33), in step S34, the control unit 10 determines whether or not there was a command to display the remaining charge of the battery 15 (step S34).

[0099] One example of a command that should display the remaining battery level of the battery 15 is when the user touches the touch panel 11 of any electronic paper 1, as shown in Figure 6. Additionally, if the battery level of the master electronic paper 1A's battery 15 drops to a threshold requiring replacement, the remaining battery level of the battery 15 may be displayed to inform the user.

[0100] Next, if there is a command to display the remaining charge of the battery 15 (if the determination in step S34 is Yes), in step S35, the control unit 10 causes the display unit 111 to display the remaining charge of the battery 15 (such as an icon displaying the remaining charge of the battery 15 as shown in Figure 6) (step S35).

[0101] Next, in step S36, the control unit 10 determines whether or not the battery 15 has been charged (step S36).

[0102] If the battery 15 is charged (if the determination in step S36 is Yes), in step S38, the control unit 10 of the master electronic paper 1A transmits a predetermined recovery signal to the control units 10 of the sub-electronic papers 1B to 1D in order to restore them from the power-saving state (step S38).

[0103] If the batteries 15 of multiple electronic paper displays 1 are being charged simultaneously, a predetermined recovery signal is sent to the sub-electronic paper displays 1B to 1D once the charging of all of the batteries 15 of the electronic paper displays 1 is complete.

[0104] Furthermore, even if the battery level of any of the electronic paper 1s is not displayed, and the user charges the battery 15 of any electronic paper 1, a predetermined recovery signal may be sent to the sub-electronic paper 1B to 1D.

[0105] On the other hand, if the battery 15 is not charged (if the determination in step S36 is No), the control unit 10 returns to the determination in step S34 (step S34).

[0106] In step S34, if there is no command to display the remaining charge of the battery 15 (including cases where the display of the remaining charge of the battery 15 is canceled) (if the determination in step S34 is No), in step S37, the control unit 10 of the master electronic paper 1A determines whether the remaining charge of the battery 15 of the master electronic paper 1A has fallen below a predetermined threshold (step S37).

[0107] In this way, when the battery 15 of the electronic paper 1 is replaced, the electronic paper 1 with the most remaining charge is set as the master electronic paper 1A, and the remaining electronic paper 1s are set as sub-electronic papers 1B to 1D, thereby realizing an electronic paper system 100 that can reduce the overall power consumption of the system compared to conventional systems.

[0108] Preferred embodiments of this invention include combinations of any of the above-described embodiments. In addition to the embodiments described above, various modifications of this invention are possible. These modifications should not be considered outside the scope of this invention. This invention should include the meaning of the claims and equivalents and all variations within that scope. [Explanation of Symbols]

[0109] 1: Electronic paper, 1A: Master electronic paper, 1B~1D: Sub electronic paper, 2: Server, 3: Network, 4: USB hub, 5: Cable, 10: Control unit, 11: Touch panel, 12: Timer, 13: Communication unit, 14: Memory unit, 15: Battery, 16: Image processing unit, 17: Image signal output unit, 100: Electronic paper system, 111: Display unit, 112: Operation unit

Claims

1. An electronic paper system consisting of multiple electronic paper sheets, Each of the plurality of electronic paper displays comprises a communication unit that acquires image data from a server, a display unit that displays an image based on the image data by rewriting the display image, an image signal output unit that outputs an image signal to the display unit for rewriting the display image, a control unit that controls the communication unit, the display unit and the image signal output unit, and a battery that supplies power to the electronic paper. Each of the image signal output units of the plurality of electronic paper is capable of outputting the image signal to the display units of all of the plurality of electronic paper. The control unit sets one of the plurality of electronic papers as the master electronic paper and the remaining electronic papers as sub-electronic papers. An electronic paper system characterized in that, in the master electronic paper, the control unit controls the communication unit to acquire the image data to be displayed on all of the multiple electronic paper from the server, and controls the image signal output unit to output the image signal to the display unit of all of the multiple electronic paper.

2. The electronic paper system according to claim 1, wherein the control unit transitions the sub-electronic paper to a predetermined power-saving state.

3. The system further includes a memory unit for storing the remaining charge of the aforementioned battery, The electronic paper system according to claim 1, wherein the control unit sets the electronic paper with the largest remaining capacity among the plurality of electronic papers as the master electronic paper, and sets the remaining electronic papers as sub-electronic papers.

4. The electronic paper system according to claim 3, wherein when the remaining charge of the battery of the master electronic paper falls below a predetermined threshold, the control unit sets the electronic paper with the largest remaining charge among the sub-electronic papers as the master electronic paper, and sets the remaining electronic papers as sub-electronic papers.

5. The electronic paper system according to claim 1, wherein the image signal output unit outputs the image signal to the display unit for rewriting the display image and supplies power to the display unit for rewriting the display image.

6. The system further includes a hub device that relays communication between the image signal output unit and the display unit. The electronic paper system according to claim 1, wherein each of the image signal output units of the plurality of electronic paper is connected to all of the plurality of electronic paper via a cable through the hub device.

7. The electronic paper system according to claim 1, which has a multi-display function that allows an image based on the image data received from the server to be displayed on the entire large screen when a large screen is formed by arranging the plurality of electronic paper displays.

8. The electronic paper system according to claim 7, wherein the control unit causes the communication unit to acquire the image data from the server at a predetermined timing, and displays the image based on the image data across the entire large screen.

9. The display unit includes color particles that move when a predetermined writing voltage is applied from the battery. The electronic paper system according to any one of claims 1 to 8, wherein the control unit displays the image by applying the writing voltage to the color particles based on the image data to the display unit.

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