Electronic paper rewriting device and rewriting method

Abstract

The goal is to enable rewriting of e-paper displays even with a low-output power supply, making it possible to use a variety of power sources. [Solution] An electronic paper rewriting device comprising: a rewriting circuit for rewriting electronic paper; a power supply connection circuit for connecting the rewriting circuit to one or more power supplies; and a control unit that acquires the power supply capacity of the power supplies connected to the rewriting circuit and determines the size of the unit area when rewriting according to the acquired power supply capacity, wherein if the determined unit area is smaller than the entire area of ​​the electronic paper, the control unit rewrites the unit area and then sequentially shifts the unit area to an unrewritten position to rewrite the entire area.

Description

Technical Field

[0005] , , ,

[0001] The present disclosure relates to a rewritable device and a rewritable method for electronic paper, and more particularly to a rewritable device and a rewritable method that receive power supply from any of a plurality of types of power sources and perform rewriting of electronic paper.

Background Art

[0002] Electronic paper is a display device having an excellent characteristic of not consuming power during display. On the other hand, there are also problems peculiar to electronic paper, which is one of the factors hindering its widespread use. For example, one of the typical electronic paper methods today is the electrophoresis method, but the time required for rewriting is longer compared to liquid crystal display devices, organic EL display devices, etc. Some large-sized color electronic papers require an order of 10 seconds for rewriting the entire area. In addition, a phenomenon called flashing accompanies the rewriting process. Flashing refers to an intermediate state screen until a desired screen is displayed.

[0003] In order to make the flashing during the rewriting of electronic paper less noticeable, a technique has been proposed in which the rewriting target area is divided into a plurality of sub-areas, and the rewriting start timing of each sub-area is set so that the flashing during rewriting is displayed at different timings, and the rewriting process is performed for each sub-area. The flashing of each sub-area appears shifted, giving the impression as if the page is being scrolled or flipped. (For example, see Patent Document 1)

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] Electronic paper does not consume power while displaying an image. However, it does consume power for a short time when rewriting the display. For example, in electrophoretic electronic paper using microcapsules, when rewriting, a voltage is applied to electrodes facing each other, sandwiching the microcapsules placed on the display surface. The resulting electric field causes the white and black pigments within the microcapsules to move, changing their distribution. When rewriting, a power supply is needed to provide the power required to apply the voltage to the electrodes. In particular, large color electronic paper displays, such as those exceeding 30 inches, may require instantaneous power of up to 50 watts when rewriting, and the magnitude of the instantaneous power output required for rewriting is one aspect that limits the widespread adoption of large color electronic paper displays. This disclosure has been made in consideration of the circumstances described above, and provides an electronic paper rewriting device and rewriting method that enables rewriting of electronic paper even with a low-output power supply and is applicable to various power supplies. [Means for solving the problem]

[0006] This disclosure provides an electronic paper rewriting device comprising: a rewriting circuit for rewriting electronic paper; a power supply connection circuit for connecting the rewriting circuit to one or more power supplies; and a control unit that acquires the power supply capacity of the power supplies connected to the rewriting circuit and determines the size of the unit area when performing the rewriting according to the acquired power supply capacity, wherein if the determined unit area is smaller than the entire area of ​​the electronic paper, the control unit rewrites the unit area and then sequentially shifts the unit area to an unrewritten position to rewrite the entire area.

[0007] Furthermore, from a different perspective, this disclosure provides a method for rewriting electronic paper, comprising the steps of: a processor recognizing the connection between a rewriting circuit that rewrites electronic paper and one or more power supplies; acquiring the power supply capacity of the power supplies connected to the rewriting circuit; determining the size of a unit area to be rewritten according to the acquired power supply capacity; and using the rewriting circuit to rewrite the electronic paper for each unit area, wherein, in the rewriting step, if the determined unit area is smaller than the entire area of ​​the electronic paper, the unit area is rewritten, and then the unit area is sequentially shifted to an unrewritten position to rewrite the entire area. [Effects of the Invention]

[0008] In the electronic paper rewriting device according to this disclosure, the control unit determines the size of the unit area to be rewritten according to the acquired power supply capacity. If the determined unit area is smaller than the entire area of ​​the electronic paper, the control unit rewrites the unit area and then sequentially shifts the unit area to an unrewritten position to rewrite the entire area. Thus, electronic paper rewriting is possible even with a low-output power supply, and various power supplies can be applied. The electronic paper rewriting method described in this disclosure produces similar effects. [Brief explanation of the drawing]

[0009] [Figure 1] This disclosure shows an external perspective view illustrating an example of a display device using electronic paper. [Figure 2] Figure 1 is a rear view of the display device shown. [Figure 3] This block diagram shows the circuit and connectable devices of the display device shown in Figure 1. [Figure 4] This diagram schematically illustrates multiple low drivers for driving the low electrodes and multiple column drivers for driving the column electrodes of an electronic paper according to the present disclosure. [Figure 5]Figure 3 shows the first flowchart illustrating an example of the rewriting process for each unit area performed by the control unit. [Figure 6] Figure 3 shows a second flowchart illustrating an example of the rewriting process for each unit area performed by the control unit. [Modes for carrying out the invention]

[0010] The following disclosure will be further described with reference to the drawings. The following description is illustrative in all respects and should not be construed as limiting the disclosure.

[0011] Figure 1 is an external perspective view showing the front side of a display device as an example of a digital signage display (electronic billboard) using electronic paper in this disclosure. The display device 12 shown in Figure 1 is an electronic paper 10 with a frame 11, and Figure 1 shows an example where it is installed on a self-standing frame stand 13. Note that the legs of the frame stand 13 are omitted from the illustration in Figure 1. The display device 12 has a shape and size suitable for applications such as POP (Point of Purchase) advertising and information boards. For this application, the size of the electronic paper 10 is preferably 20 inches or more when expressed by the diagonal length, similar to televisions, etc. (approximately equivalent to the area of ​​A3 size paper).

[0012] The display device 12 shown in Figure 1 incorporates a circuit for rewriting the electronic paper 10, has multiple types of connectors for connecting an external power supply, and has a mounting section for installing a battery as a power source.

[0013] Figure 2 is a rear view of the display device 12 shown in Figure 1. As shown in Figure 2, the display device 12 has a circuit housing section 20 that protrudes slightly from the center of the rear side. The circuit housing section 20 houses the control circuit 31, reprogramming circuit 32, and wireless communication module 36, which will be described later, and can also accommodate an optional battery 35. A connector panel 21 is provided on the protruding side of the circuit housing section 20. The connector panel 21 has one Type-A connector 22 and two Type-C connectors 23 and 24 for USB connection. In addition, a rectangular cover 25 is provided on the rear of the circuit housing section 20, which is opened when the battery 35 is installed and housed there.

[0014] Figure 3 is a block diagram showing the control circuit 31 and rewriting circuit 32 housed in the circuit housing section 20, as well as devices connected to or connectable to them. As shown in Figure 3, the control circuit 31 can receive a maximum power supply of 5V × 500mA = 2.5 watts from a device connected to the Type-A connector 22 (PC34 in the example in Figure 3). 2.5 watts of power is the upper limit for Type-A as defined by the USB standard. The control circuit 31 can also receive a maximum power supply of 5V × 3A = 15 watts from a device connected to the Type-C connector 23 (PC37 in the example in Figure 3). 15 watts of power is the upper limit for Type-C as defined by the USB standard.

[0015] Furthermore, the control circuit 31 can also receive up to 20V × 5A = 100 watts of power from a device connected to the Type-C connector 24 that complies with the PD (Power Delivery) standard (in the example in Figure 3, the AC adapter 33). 100 watts of power is the upper limit specified in the PD standard. However, in practice, the voltage value (whether 5V, 9V, 15V, or 20V) and the upper limit of the current are determined by negotiation at the time of connection. Alternatively, the control circuit 31 can also receive power from the battery 35 if the battery 35 is installed. Thus, multiple types of devices can be connected to the control circuit 31, and it can operate by receiving power from the connected devices. The power supplied from these devices is also supplied to the rewriting circuit 32, which will be described later. The electronic paper 10 is connected to the rewriting circuit 32, and the power supplied to the rewriting circuit 32 is used to apply voltage to electrodes formed to apply an electric field voltage to microcapsules arranged on the display surface of the electronic paper 10, thereby performing rewriting.

[0016] The control circuit 31 includes a control unit 31C, a work memory 31M, a non-volatile memory 31N, a power management element 31P, a power selector 31S, a Type-C controller 31U, and a DC-DC converter 31D.

[0017] The control unit 31C controls the entire display device 12. The control unit 31C reads a control program stored in the non-volatile memory 31N and executes it via the processor, thereby performing various processes including rewriting the electronic paper 10. A System on a Chip (SoC) can be used as the control unit 31C. However, it is not limited to this and may be implemented by, for example, a CPU (Central Processing Unit). The control unit 31C is not limited to one circuit but may be composed of multiple circuits.

[0018] As the work memory 31M, for example, DRAM or SDRAM is applicable. The work memory 31M provides a storage area required when the control unit 31C executes various processes including rewriting of the electronic paper 10. As the non-volatile memory 31N, for example, a flash memory, an SSD (Solid State Disk), etc. are applicable. The non-volatile memory 31N stores a processing program of the control unit 31C, image data to be displayed on the electronic paper 10, etc. As the power management element 31P, for example, a PMIC (Power Management IC) is applicable. The power management element 31P not only supplies power for operating the control unit 31C, but also performs a power-on sequence, power saving control, etc.

[0019] The power selector 31S is a circuit that selects which of the Type-A connector 22, the Type-C connectors 23, 24, and the battery 35 receives power supply under the control of the control unit 31C. The connectors to which the Type-A connector 22, the Type-C connectors 23, 24, and the battery 35 are connected correspond to the connection parts in the present disclosure. The power selector 31S corresponds to the selection circuit in the present disclosure. The power selector 31S connects one of those connectors to the power supply line of the control circuit 31 and the rewriting circuit 32 under the control of the control unit 31C. That is, the power selector 31S makes one of the connectors be in a state connected to the power supply line of the control circuit 31 and the rewriting circuit 32 under the control of the control unit 31C, and the control circuit 31 and the rewriting circuit 32 receive power supply from the device connected to that connector. Those connectors corresponding to the connection parts, the power selector 31S, and the line connecting both of them correspond to the power supply connection circuit of the present disclosure.

[0020] Note that the power selector 31S may be configured to detect whether or not a device is connected to a connector that is not selected and is in a state where power can be supplied. However, the control unit 31C may be directly configured to detect whether or not a device is connected to each connector and is in a state where power can be supplied. The power selector 31S selectively selects a connector to which the control circuit 31 and the rewriting circuit 32 receive power supply. The Type-C controller 31U is a circuit element that mainly performs negotiation according to the PD standard. When a device is connected to the Type-C connector 24, the Type-C controller 31U negotiates with the connected device. Then, the upper limit values of the voltage and current received from the device are determined.

[0021] The DC-DC converter 31D converts the voltage of the power supply provided from the control circuit 31 to the rewriting circuit 32 to the voltage required by the rewriting circuit 32 and stabilizes that voltage. The control circuit 31 is connected to the rewriting circuit 32 via a connector. The rewriting circuit 32 is connected to the electronic paper 10 via an FPC (Flexible Printed Circuit) connector. In the active-matrix electronic paper 10, multiple transparent low electrodes extending parallel to each other in the horizontal direction and multiple transparent column electrodes extending parallel to each other in the vertical direction are formed on the front side of the display surface where the microcapsules are arranged. Transistors and transparent electrodes for applying voltage to the microcapsules are formed at the intersections of each low electrode and each column electrode. These transparent electrodes correspond to pixels arranged in a matrix in the vertical and horizontal directions. In the case of color electronic paper, a color filter is arranged corresponding to each transparent electrode, and each transparent electrode corresponds to one of the primary colors that make up one pixel. When the low electrodes and column electrodes are scanned, an electric field corresponding to the driving voltage is generated between each transparent electrode and the electrode formed on the back side, sandwiching the microcapsule. The electric field causes the white and black pigments within the microcapsules to move, changing the distribution of the white and black pigments on the display surface, and thus displaying an image. In this way, when rewriting, it is necessary to apply a voltage to the low electrode and column electrode to generate an electric field, and the DC-DC converter 31D stabilizes the voltage applied to the low electrode and column electrode of the electronic paper 10 during rewriting.

[0022] The rewriting circuit 32 includes a timing control circuit 32T and a drive circuit 32D. The timing control circuit 32T controls the timing of the scanning signal applied to the low electrodes and column electrodes of the electronic paper 10 during rewriting. The drive circuit 32D includes multiple low drivers that drive multiple low electrodes extending laterally and multiple column drivers that drive multiple column electrodes extending vertically, based on the scanning signal generated by the timing control circuit 32T. With this configuration, the pixels of the electronic paper, which are arranged in a matrix in both vertical and horizontal directions, can be rewritten by the rewriting circuit including the column drivers and low drivers.

[0023] Figure 4 is a schematic diagram illustrating multiple low drivers that drive each low electrode extending horizontally and multiple column drivers that drive each column electrode extending vertically on the electronic paper 10. In the example shown in Figure 4, each low electrode is driven using four low drivers 44R1 to 44R4 arranged in the short side direction of the electronic paper 10, and each column electrode is driven using eight column drivers 45C1 to 45C8 arranged in the long side direction. In this disclosure, as shown in Figure 4, the long side direction of the electronic paper 10 is considered the horizontal direction, and the short side direction is considered the vertical direction. Figures 1 and 2 show the electronic paper 10 shown in Figure 4 rotated 90 degrees so that the long side faces vertically. Hereinafter, the vertical direction will be referred to as the long side direction, and the horizontal direction as the short side direction.

[0024] In Figure 4, the number of low electrodes extending in the long-side direction and parallel to the short-side direction, in other words, the number of pixels aligned in the short-side direction, is 1800 in one example. Also, the number of column electrodes extending in the short-side direction and parallel to the long-side direction, in other words, the number of pixels aligned in the long-side direction, is 3200 in one example. In that example, the four low drivers 44R1 to 44R4 each drive one-quarter of 1800, i.e., 450 low electrodes, and the eight column drivers 45C1 to 45C8 each drive one-eighth of 3200, i.e., 400 column electrodes. If the region driven by one low driver and one column driver is considered one division, then one division in the short-side direction is 1 / 4 of the short side, and one division in the long-side direction is 1 / 8 of the long side. Note that the above numbers of low electrodes and column electrodes, and the number of drivers that drive them, are just examples.

[0025] In this disclosure, the size of the unit area for rewriting is determined based on design or experimentation according to the power supply capacity of the power supply selected by the power selector 31S, and is pre-stored in the non-volatile memory 31N. In this way, the power supply capacity of the power supply connected to a connector can be determined according to which connector is selected by the selection circuit 31S. As an example, Figure 4 shows an example of the size of the unit area corresponding to the power supply capacity of each power supply. In the example shown in Figure 4, the unit area corresponding to the Type-C connector 24 that complies with the PD standard and the Type-C connector 23 that does not complies with the PD standard is the entire area 41 of the electronic paper 10. That is, it is an area with a size of 4 divisions in the short side direction and 8 divisions in the long side direction. In the example shown in Figure 4, the power required to rewrite the entire area 41 is 50 watts. In the case of the Type-C connector 24 that complies with the PD standard, the voltage of 20V and the current of 2.5A are supported when receiving a 50-watt power supply.

[0026] For the Type-C connector 23, which does not support the PD standard, the voltage when power is supplied is 5V and the maximum current is 3A, and the size of the corresponding unit area is a sub-area 42. The sub-area 42 is an area with one division in the short-side direction and eight divisions in the long-side direction. For the Type-A connector 22, the voltage when power is supplied is 5V and the maximum current is 500mA, and the size of the corresponding unit area is a sub-area 43. The sub-area 43 is an area with one division in the short-side direction and four divisions in the long-side direction. The size of the unit area corresponding to the battery 35 is a sub-area 44. The sub-area 44 is an area with one division in the short-side direction and one division in the long-side direction. The control unit 31C determines the unit area to be rewritten according to the power supply capacity of the selected power supply, and if the determined unit area is smaller than the entire area of ​​the electronic paper 10, it sequentially shifts the unit areas to rewrite the entire area. In this way, by making the area driven by one or more driver elements correspond to the length and width of a unit region, it is possible to sequentially rewrite each unit region corresponding to the driving area of ​​one or more driver elements.

[0027] Returning to the explanation of Figure 3, the wireless communication module 36 is used to rewrite the electronic paper 10 via wireless communication from an external PC, smartphone, etc. However, in addition to rewriting using wireless communication, the electronic paper 10 can also be rewritten by connecting a PC or USB memory to the USB connector (Type-A connector 22 or Type-C connector 23).

[0028] Flowchart Next, the flow of the rewriting process for each unit area executed by the control unit 31C will be explained with reference to the flowchart. Figures 5 and 6 are flowcharts showing an example of the rewriting process for each unit area executed by the control unit 31C. Note that Figures 5 and 6 focus on the determination of the unit area to be rewritten and the corresponding rewriting process among the various processes executed by the control unit 31C, and other processes executed by the control unit 31C are omitted.

[0029] When power is supplied to the control circuit 31, the control unit 31C performs an initialization process (not shown in Figure 5) and then checks via the power selector 31S which of the Type-A connector 22, Type-C connectors 23 and 24, and battery 35 connectors is in a state where power can be supplied. In the embodiment shown in the flowchart, the control unit 31C selects the power supply that can supply the largest amount of power from among the power supplies that are in a state where power can be supplied. Specifically, it first determines whether a device such as an AC adapter 33 is connected to the Type-C connector 24 which is compliant with the PD standard and whether it is in a state where power can be supplied (step S11). If power can be supplied from the Type-C connector 24 (Yes in step S11), the power supply capacity obtained by the Type-C controller 31U through negotiation is obtained from the Type-C controller 31U (step S13). Then, it determines whether it is possible to supply the power necessary to rewrite the entire area as a unit area for rewriting the electronic paper 10 (step S15). In this way, when a power supply capable of changing its power supply capacity through communication (negotiation) is connected to the connection part, the power supply capacity of that power supply can be determined based on the communication (negotiation). Here, it is assumed that the power required to rewrite the entire area is determined by design or experiment and is stored in the non-volatile memory 31N in advance. If the determination in step S15 determines that the power required to rewrite the entire area of ​​the electronic paper 10 can be supplied (Yes in step S15), the control unit 31C sets the entire area of ​​the electronic paper 10 as the unit area for rewriting (step S17).

[0030] Once the size of the unit area is determined, the position of the unit area to be rewritten first is selected according to the determined size of the unit area (step S21). If the unit area is the entire area of ​​the electronic paper 10, the entire area is selected. If the unit area is smaller than the entire area, the first position is selected. Then, the control unit 31C instructs the rewriting circuit 32 to use the selected unit area position. In this way, the control unit 31C specifies the position of the unit area, and the electronic paper 10 can be rewritten by using the rewriting circuit 32 to rewrite the specified position.

[0031] The control unit 31C instructs the rewriting circuit 32 to perform rewriting on the selected unit area (step S23). Once the rewriting of the unit area is complete, the control unit 31C determines whether or not the rewriting of all areas of the electronic paper 10 is complete (step S25). That is, it determines whether there are any areas that have not been rewritten. If there are areas that have not been rewritten (No in step S25), the control unit 31C selects the unit area to be rewritten next from among the areas that have not been rewritten and instructs the rewriting circuit 32 of its position (step S27). Then, it returns to step S23 and instructs the rewriting circuit 32 to perform rewriting on the selected unit area. In this way, the control unit 31C shifts the unit area to the areas that have not been rewritten and performs rewriting sequentially until the rewriting of all areas of the electronic paper 10 is complete. Once the rewriting of all areas of the electronic paper 10 is complete (Yes in step S25), the rewriting process for each unit area is terminated.

[0032] On the other hand, if the determination in step S15 above determines that it is not possible to supply the power necessary to rewrite the entire area of ​​the electronic paper 10 (No. in step S15), the control unit 31C acquires a unit area for rewriting according to the acquired power supply capacity and sets it as a candidate (step S19). Here, the size of the unit area according to the power supply capacity is determined by design or experiment and is assumed to be stored in the non-volatile memory 31N in advance. Then the process proceeds to step S31 shown in Figure 6. Also, if the determination in step S11 above determines that it is not possible to supply power from the Type-C connector 24 that complies with the PD standard (No. in step S11), the process proceeds to step S31 shown in Figure 6.

[0033] In step S31 shown in Figure 6, the control unit 31C determines whether or not a device such as a PC 37 is connected to the Type-C connector 23. If power can be supplied from the Type-C connector 23 (Yes in step S31), the control unit 31C obtains a unit area for rewriting according to a predetermined power supply capacity for the Type-C connector 23 and sets it as a candidate (step S33). Then, the process proceeds to step S35. Here, the power supply capacity of the Type-C connector 23 that does not support the PD standard is defined as 5V × 3A = 15W according to the USB standard. The size of the unit area according to that power supply capacity is determined by design or experimentation and is assumed to be stored in the non-volatile memory 31N in advance. If, in the determination in step S31, power cannot be supplied from the Type-C connector 23 (No in step S31), the process proceeds to step S35.

[0034] In step S35, the control unit 31C determines whether or not a device such as a PC 34 is connected to the Type-A connector 22. If power can be supplied from the Type-A connector 22 (Yes in step S35), the control unit 31C obtains a unit area for rewriting from the Type-A connector 22 according to a predetermined power supply capacity and sets it as a candidate (step S37). Then, the process proceeds to step S39. Here, the power supply capacity of the Type-A connector 22 is defined as 5V × 500mA = 2.5W according to the USB standard. The size of the unit area corresponding to that power supply capacity is determined by design or experimentation and is assumed to be stored in the non-volatile memory 31N in advance. If, in the determination in step S35, power cannot be supplied from the Type-A connector 22 (No in step S35), the process proceeds to step S39.

[0035] In step S39, the control unit 31C determines whether the battery 35 is connected or not. If the battery 35 is connected and power can be supplied (Yes in step S39), the control unit 31C obtains a unit area for rewriting according to a predetermined power supply capacity for the battery 35 and sets it as a candidate (step S39). Then, the process proceeds to step S43. Here, the power supply capacity of the battery 35 and the size of the unit area corresponding to that power supply capacity are determined by design or experiment and are pre-stored in the non-volatile memory 31N. If the determination in step S39 above indicates that the battery 35 is not connected and power can be supplied (No in step S39), the process proceeds to step S43. In step S43, the control unit 31C determines the largest unit area among the set candidates as the unit area to be rewritten, and instructs the power selector 31S to select a power supply corresponding to the determined unit area. Then, the process returns to step S21 shown in Figure 5, and the position of the unit area to be rewritten first is selected according to the size of the determined unit area. Subsequently, as shown in steps S23 to S27 in Figure 5, the unit areas are shifted to unrewritten areas and rewritten sequentially until the rewriting of all areas is completed. The above is the flow of the rewriting process for each unit process executed by the control unit 31C.

[0036] (Embodiment 2) In Embodiment 1, the control unit 31C selects the power supply corresponding to the largest unit area among the power supplies that are in a power supply state, and sequentially rewrites each unit area corresponding to the power supply capacity of that power supply. Unlike Embodiment 1, in which the control unit 31C selects the power supply, the user may be allowed to select the power supply. In this embodiment, the user can switch between multiple power supplies that are connected via any connector and are in a power supply state by operating a changeover switch (not shown). For example, each time the user presses a changeover switch (not shown) provided on the display device 12, the control unit 31C operates the power selector 31S to sequentially switch between multiple power supplies that are in a power supply state in response to that operation. During rewriting, the control circuit 31 is receiving power from the power supply selected in this way. The control unit 31C determines the unit area of ​​size corresponding to the selected power supply and sequentially rewrites each unit area.

[0037] (Embodiment 3) In Embodiment 1, the power selector 31S selectively selects one of the connectors; that is, it selects one power source. However, the power selector 31S may be configured to select multiple power sources simultaneously. According to this embodiment, the rewriting process can be performed by receiving power from multiple power sources simultaneously. In this embodiment, the power selector 31S is configured to set whether or not to receive power from the device connected to each of the Type-A connector 22, Type-C connectors 23 and 24, and battery 35. The control circuit 31 and the rewriting circuit 32 receive power from one or more selected power sources. However, the power sources that can be selected simultaneously are limited to power sources of the same voltage. For example, since the power sources connected to the Type-A connector 22 and the Type-C connector 23 are both 5V power sources, power can be received from both power sources simultaneously. Regarding the Type-C connector 24 that complies with the PD standard, consider, for example, the case where a device is connected to the Type-C connector 24 while a 5V power source is selected for the other Type-A connector 22 or Type-C connector 23. In this case, the device connected to the Type-C connector 24 can be configured by negotiation to supply a voltage of 5V and a current of up to 3A. When rewriting while receiving power from multiple power sources, the control unit 31C determines a unit area of ​​a size corresponding to the total power supply capacity of the selected multiple power sources. Then, it sequentially rewrites each determined unit area.

[0038] (Embodiment 4) In embodiments 1 to 3, the size of the unit area related to rewriting is determined by the control unit 31C according to the maximum power supply capacity of the selected power supply. In this embodiment, the control unit 31C applies a predetermined amount of reduced maximum power supply capacity of the selected power supply according to at least one of the following: time, day, or the amount of power consumed by other power loads, and determines the size of the unit area related to rewriting according to that power supply capacity. According to this embodiment, when power supply conditions differ depending on the time, day, and the amount of power consumed by other power loads, the power supply capacity of the power supply can be determined in accordance with those conditions, and the size of the unit area related to rewriting the electronic paper can be changed based on the determined power supply capacity.

[0039] For example, suppose the display device 12 receives power from an AC adapter 33 connected to a Type-C connector 24. The AC adapter 33 is connected to an AC outlet in the store where the display device 12 is installed. When the rewrite is performed during the period from 6:00 AM to 11:29 PM, when there is foot traffic, the control unit 31C sets the unit area to the entire area. However, when the rewrite is performed during the period from 11:30 PM to 5:29 AM, when there is no foot traffic, the control unit 31C may determine the unit area to be a partial area to limit the power required to rewrite the entire area at once (e.g., 50 watts) to 12.5 watts, which is 1 / 4 of the total power required to rewrite the entire area at once, and then sequentially rewrite each determined unit area. The settings for the period when the unit area is the entire area and the period when the unit area is a partial area may be set by the user using an application on a PC, for example, and the setting value may be stored in the non-volatile memory 31N in advance via the wireless communication module 36 or any connector.

[0040] Furthermore, during the store's operating days or hours, the unit area may be determined to limit the power required to rewrite the entire area at once to half, or 25 watts, of the power required (e.g., 50 watts). This is because other power equipment within the store uses power during the store's operating days or hours. The store's operating days or hours may be set by the user using an application on a PC, for example, and the setting value may be stored in the non-volatile memory 31N in advance via the wireless communication module 36 or any connector.

[0041] Alternatively, for example, the control unit 31C may communicate with a HEMS (Home Energy Management System) control device (not shown) via a wireless communication module 36. This HEMS control device manages the power consumption of the entire store where the display device 12 is installed. When the control unit 31C receives instructions from the HEMS control device, it may determine a unit area in accordance with those instructions to reduce the instantaneous power required for rewriting. In that case, the control unit 31C may determine a unit area in accordance with the instructions to reduce the power required to rewrite the entire area at once (e.g., 50 watts) to a ratio corresponding to the instructions, for example, 1 / 5 or 10 watts, and then sequentially rewrite each determined unit area.

[0042] This disclosure should be understood to include combinations of any of the above-described embodiments. In addition to the embodiments described above, various modifications of this disclosure are possible. These modifications should not be construed as being outside the scope of this disclosure. This disclosure should include the meaning of equivalents to the claims and all variations that fall within the scope of this disclosure. [Explanation of Symbols]

[0043] 10: Electronic paper, 11: Frame, 12: Display device, 13: Frame stand, 20: Circuit housing, 21: Connector panel, 22: Type-A connector, 23,24: Type-C connector, 25: Cover, 31: Control circuit, 31C: Control unit, 31D: DC-DC converter, 31M: Work memory, 31N: Non-volatile memory, 31P: Power management element, 31S: Power selector, 31U: Type-C controller, 32: Rewrite circuit, 32D: Drive circuit, 32T: Timing control circuit, 33: AC adapter, 34,37: PC, 35: Battery, 36: Wireless communication module, 44R1~44R4: Low driver, 45C1~45C8: Column driver, 41: Full area, 42,43,44: Partial area

Claims

1. A rewriting circuit that rewrites the electronic paper, A power connection circuit that connects the rewriting circuit to one or more power supplies, The system includes a control unit that acquires the power supply capacity of the power supply connected to the rewriting circuit and determines the size of the unit area when performing the rewriting according to the acquired power supply capacity, The control unit, when the determined unit area is smaller than the entire area of ​​the electronic paper, rewrites the unit area, then sequentially shifts the unit area to an unrewritten position to rewrite the entire area, thereby rewriting the entire area.

2. The aforementioned power supply connection circuit is Multiple power supplies that can be connected to the rewriting circuit and multiple connection points that correspond one-to-one, The rewriting circuit and a selection circuit that selects which connection point to connect to are included, The control unit, It includes a memory unit that pre-stores the power supply capacity of each power source, linked to each connection point that corresponds one-to-one with each power source. The rewriting device according to claim 1, which determines the size of the unit area according to the power supply capacity stored in the storage unit in association with the selected connection unit.

3. The rewriting device according to claim 2, wherein the control unit communicates with the power supply connected to the connection unit to obtain the range of power that the power supply can supply, specifies the power to be supplied based on the range of power supply capacity obtained, and determines the size of the unit area based on the specified power.

4. The rewriting device according to claim 3, wherein the control unit specifies the size of the unit area according to at least one of the time, days, and an external instruction to reduce power consumption for the rewriting.

5. The aforementioned electronic paper has pixels arranged in a matrix in both vertical and horizontal directions. The rewriting circuit includes a column driver that drives vertical pixel lines in which the pixels are arranged vertically, and a row driver that drives horizontal pixel lines in which the pixels are arranged horizontally. The rewriting device according to claim 1, wherein the control unit controls the column driver to drive pixel lines corresponding to the vertical region of the unit region, and controls the row driver to drive pixel lines corresponding to the horizontal region of the unit region to rewrite the unit region.

6. The column driver and the row driver are each composed of multiple driver elements, and each driver element drives one of the pixel lines obtained by dividing the unidirectional pixel line into multiple sections. The rewriting device according to claim 5, wherein the size of the unit area corresponds to the pixel line of the one division.

7. The control unit specifies the position of the unit region to be rewritten to the rewriting circuit, The rewriting device according to claim 1, wherein the rewriting circuit rewrites pixels in a unit region at a specified position.

8. The power supply connection circuit can connect multiple power supplies to the rewriting circuit and receive power from each of the power supplies. The rewriting device according to claim 1, wherein the control unit determines the size of the unit area according to the total power supply capacity of each connected power source.

9. The processor, A step of recognizing the connection between a rewriting circuit that rewrites the e-paper and one or more power sources, The steps include obtaining the power supply capability of the power supply connected to the rewriting circuit, A step of determining the size of the unit area when performing the rewrite according to the acquired power supply capacity, The process includes the step of rewriting the electronic paper for each unit region using the rewriting circuit, The rewriting step is a method for rewriting electronic paper, in which, if the determined unit area is smaller than the entire area of ​​the electronic paper, the unit area is rewritten, and then the unit area is sequentially shifted to an unrewritten position to rewrite the entire area.

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