Control method, controller, control system, and recording medium
The controller manages peak power consumption in electronic papers by monitoring current flow and granting rewrite permissions based on a threshold, ensuring efficient power usage and stable operation without additional components.
Patent Information
- Authority / Receiving Office
- WO · WO
- Patent Type
- Applications
- Current Assignee / Owner
- NEC CORP
- Filing Date
- 2024-12-10
- Publication Date
- 2026-06-18
Smart Images
Figure JP2024043519_18062026_PF_FP_ABST
Abstract
Description
Control Method, Controller, Control System, and Recording Medium 【0001】 The present disclosure relates to a control method and the like. 【0002】 There is a technology for displaying data indicating such content on an electronic paper in order to display various contents such as advertisements and guides. For example, Patent Document 1 describes a technology for controlling writing to a plurality of electronic papers. 【0003】 Japanese Patent Application Laid-Open No. 2004-237577 【0004】 An electronic paper does not consume power when displaying, but consumes power when rewriting the display. For example, when a plurality of electronic papers are connected to one controller and one controller rewrites a plurality of electronic papers simultaneously, the power consumption may temporarily increase. 【0005】 An example of the object of the present disclosure is to provide a control method or the like for equalizing the peak power consumption of the power line of the power supply supplied to the electronic paper. 【0006】 The control method in one aspect of the present disclosure is connected to a plurality of electronic papers, and a controller that controls the plurality of electronic papers transmits display information to at least some of the plurality of electronic papers, receives a rewrite request transmitted after reception of the display information is completed from any of the at least some of the electronic papers, and transmits a rewrite permission to the electronic paper that is the transmission source of the rewrite request according to a comparison result between the amount of current flowing through a power line that supplies power to the plurality of electronic papers and a threshold value corresponding to the number of electronic papers that can be rewritten simultaneously, and executes a process. 【0007】A controller in one aspect of the present disclosure is a controller connected to and controlling a plurality of electronic paper displays, comprising: display information transmission means for transmitting display information to at least some of the plurality of electronic paper displays; request receiving means for receiving a rewrite request transmitted after the reception of the display information from any of the at least some of the electronic paper displays has been completed; and rewrite permission transmission means for transmitting a rewrite permission to the electronic paper that sent the rewrite request, according to the result of comparing the amount of current flowing through a power line that supplies power to the plurality of electronic paper displays with a threshold value corresponding to the number of electronic paper displays that can be rewritten simultaneously. 【0008】 A control system in one aspect of the present disclosure comprises: a controller connected to and controlling a plurality of electronic papers; the plurality of electronic papers, wherein the controller comprises: display information transmission means for transmitting display information to at least some of the plurality of electronic papers; request receiving means for receiving a rewrite request transmitted after the reception of the display information from any of the at least some of the electronic papers has been completed; rewrite permission transmission means for transmitting rewrite permission to the electronic paper that sent the rewrite request, according to the result of comparing the amount of current flowing through a power line supplying power to the plurality of electronic papers with a threshold corresponding to the number of electronic papers that can be rewritten simultaneously; and each of the plurality of electronic papers comprises: display information receiving means for receiving the display information from the controller; request transmission means for transmitting the rewrite request to the controller after the reception of the display information has been completed; rewrite permission receiving means for receiving rewrite permission from the controller; and rewrite means for performing a rewrite based on the received display information after receiving rewrite permission from the controller. 【0009】A program in one aspect of the present disclosure causes a controller connected to a plurality of electronic paper displays to control the plurality of electronic paper displays to perform the following processes: transmit display information to at least some of the plurality of electronic paper displays; receive a rewrite request transmitted after the reception of the display information from any of the at least some of the electronic paper displays is complete; and transmit a rewrite permission to the electronic paper that sent the rewrite request, based on the result of comparing the amount of current flowing through the power lines supplying power to the plurality of electronic paper displays with a threshold corresponding to the number of electronic paper displays that can be rewritten simultaneously. 【0010】 Each program may be stored on a non-temporary recording medium that is readable by the controller. 【0011】 According to this disclosure, it is possible to equalize the peak power consumption of the power lines supplying power to the electronic paper. 【0012】 This is an explanatory diagram showing an example of a control system including a controller. This is a block diagram showing an example of a controller configuration. This is a block diagram showing an example of an electronic paper configuration. This is an explanatory diagram showing an example of the time-series change in the current amount of a power line and the transmission and reception of various signals. This is an explanatory diagram showing an example of a control system further including external power supply. This is an explanatory diagram showing a sequence diagram of a control system. This is a block diagram showing an example of a controller configuration. This is a flowchart showing an example of a controller operation. This is an explanatory diagram showing an example of a control system including a controller. This is an explanatory diagram showing an example of a computer hardware configuration. 【0013】 Embodiments of the control method, controller, control system, program, and non-temporary recording medium and electronic paper relating to this disclosure will be described in detail below with reference to the drawings. These embodiments are not intended to limit the disclosed technology. 【0014】 (First Embodiment) The first embodiment will be described in detail with reference to the drawings. In the first embodiment, the basic functions of the controller will be described. 【0015】Figure 1 is an explanatory diagram showing an example of a control system 1 including a controller 10. For example, the control system 1 comprises a controller 10, an electronic paper 11, and a battery 12. The controller 10 is connected to and controls a plurality of electronic paper 11. The number of electronic paper 11 is not particularly limited. The electronic paper 11 may be expandable. The controller 10 may be a microcontroller or a device. 【0016】 Various displays, such as advertisements, are shown on the electronic paper 11. The location where the electronic paper 11 is installed is not particularly limited. For example, the electronic paper 11 may be used as a bulletin board at a bus stop. It may also be used for displaying advertisements in facilities such as train stations and shops, or on roads. 【0017】 For example, the battery 12 supplies power to the controller 10. Furthermore, for example, the battery 12 supplies power to multiple electronic paper displays 11 via the power lines of the controller 10. For example, the electronic paper displays 11 exchange data with each other via their respective data signal lines. Note that the data signal lines may be common to multiple electronic paper displays 11. In other words, the data signal communication method between the electronic paper displays 11 and the controller 10 is not particularly limited and can be SPI (Serial Peripheral Interface) communication, USB (Universal Serial Bus) communication, I2C (Inter-Integrated Circuit) communication, etc. 【0018】 In Figure 1, there are five ports for data signal lines, and five electronic paper displays 11 can be connected to the controller 10. However, this example is not particularly limited. For example, in Figure 1, three electronic paper displays 11-1 to 11-3 are connected to the controller 10. When electronic paper displays 11-1 to 11-3 are not distinguished, they are simply referred to as electronic paper displays 11. 【0019】The controller 10 may monitor the amount of current in the power line supplying power to the electronic paper 11. Specifically, for example, the controller 10 may monitor the amount of current using a comparator. The comparator compares, for example, the value of the current flowing through the power line with a threshold value. The comparator may be located inside or outside the controller 10. 【0020】 Figure 2 is a block diagram showing one example configuration of the controller 10. In Figure 2, the controller 10 includes a display information transmission unit 101, a request reception unit 103, and a rewrite permission transmission unit 105. The controller 10 may, for example, store the results of various functional units in an internal or external storage unit of the controller 10. 【0021】 Figure 3 is a block diagram showing an example configuration of the electronic paper 11. The electronic paper 11 comprises a display information receiving unit 111, a request transmission unit 113, a rewrite permission receiving unit 115, and a rewrite unit 117. The electronic paper 11 may store, for example, the results of various functional units in an internal or external storage unit of the electronic paper 11. 【0022】 First, the display information transmission unit 101 of the controller 10 transmits the respective display information to at least some of the multiple electronic paper displays 11. The electronic paper displays 11 to which the display information transmission unit 101 transmits the display information may be all of the electronic paper displays 11 or some of the electronic paper displays 11. 【0023】 Then, the display information receiving unit 111 of the electronic paper 11 receives display information from the controller 10. Once the request sending unit 113 has finished receiving the display information, it sends a rewrite request to the controller 10. 【0024】 The request receiving unit 103 receives a rewrite request that is transmitted after the reception of display information from one of the multiple electronic paper displays 11 has been completed. 【0025】The rewrite permission transmission unit 105 transmits a rewrite permission to the electronic paper 11 that sent the rewrite request, based on the result of comparing the amount of current flowing through the power lines that supply power from the battery 12 to the multiple electronic paper 11 with a threshold value corresponding to the number of electronic paper 11 that can be displayed and rewritten simultaneously. 【0026】 The threshold is determined based on the amount of current that the battery 12 can supply. For example, if the battery 12 is 5V (volts) and 1A (ampere), the threshold is determined so as not to exceed 1A. For example, if rewriting three e-paper displays 11 simultaneously exceeds 1A, but rewriting two e-paper displays 11 simultaneously does not exceed 1A, then two e-paper displays 11 can be rewritten simultaneously. Therefore, the threshold is determined based on the amount of current when two e-paper displays 11 are being rewritten. The threshold may have a range. 【0027】 The rewrite permission transmission unit 105 transmits a rewrite permission to the electronic paper 11 that sent the rewrite request if the amount of current flowing through the power lines supplying power from the battery 12 to the multiple electronic paper 11 is less than a threshold corresponding to the number of electronic paper 11 that can be displayed and rewritten simultaneously. The rewrite permission transmission unit 105 does not transmit a rewrite permission to the electronic paper 11 that sent the rewrite request if the amount of current flowing through the power lines supplying power from the battery 12 to the multiple electronic paper 11 is greater than or equal to a threshold corresponding to the number of electronic paper 11 that can be displayed and rewritten simultaneously. For example, even if two electronic paper 11 can be rewritten simultaneously, if the amount of current flowing through the power lines is less than the amount of current when the two electronic paper 11 are being rewritten, the number of electronic paper 11 currently being rewritten is one or zero. Therefore, the rewrite permission transmission unit 105 transmits a rewrite permission to the one electronic paper 11 that sent the rewrite request. In this way, the controller 10 can monitor the amount of current flowing through the power line, thereby controlling the peak current consumption during rewriting to prevent it from becoming too high. Therefore, the controller 10 does not need to store information such as the number of discs currently being rewritten. 【0028】The rewrite permission receiving unit 115 of the electronic paper 11 receives a rewrite permission from the controller 10. Then, when the rewrite unit 117 receives the rewrite permission from the controller 10, it rewrites the electronic paper 11 based on the received display information. 【0029】 Figure 4 is an explanatory diagram showing the time-series changes in the current flow rate of the power line and examples of transmission and reception of various signals. For the sake of simplicity, the explanation will be given using the example of a case where there is one electronic paper display 11 that can be rewritten at one time. The explanation of transmission of display information will also be omitted. 【0030】 The request transmission unit 113 of the electronic paper 11-1 sends a rewrite request to the controller 10. The request receiving unit 103 of the controller 10 then receives the rewrite request from the electronic paper 11-1. 【0031】 The rewrite permission transmission unit 105 of the controller 10 transmits a rewrite permission to the electronic paper 11-1, which is the source of the rewrite request, because the current in the power line is less than the threshold. The rewrite permission receiving unit 115 of the electronic paper 11-1 receives the rewrite permission from the controller 10. Then, the rewrite unit 117 of the electronic paper 11-1 rewrites the display information with the received information. When rewriting begins, the current in the power line increases. 【0032】 Next, the request transmission unit 113 of the electronic paper 11-2 sends a rewrite request to the controller 10. Then, the request receiving unit 103 of the controller 10 receives the rewrite request from the electronic paper 11-2. 【0033】 Because the electronic paper 11-1 is being rewritten, the current flow in the power line is greater than the threshold. Therefore, the rewrite permission transmission unit 105 of the controller 10 does not send a rewrite permission to the electronic paper 11-2, which is the source of the rewrite request, because the current flow in the power line is greater than the threshold. 【0034】When rewriting is complete in the electronic paper 11-1, the current in the power line decreases. Then, when the current in the power line of the controller 10 falls below a threshold, the rewrite permission transmission unit 105 sends a rewrite permission to the electronic paper 11-2, which is the source of the rewrite request. The rewrite permission receiving unit 115 of the electronic paper 11-2 receives the rewrite permission from the controller 10. Then, the rewrite unit 117 of the electronic paper 11-2 rewrites the display information with the received information. When rewriting begins, the current in the power line increases. After that, when the rewriting of the electronic paper 11-2 is complete, the current in the power line decreases. 【0035】 Furthermore, the rewriting order of the multiple electronic paper displays 11 is predetermined, and when the rewriting permission transmission unit 105 receives rewriting requests from multiple electronic paper displays 11, it transmits rewriting permission according to the rewriting order. For example, it is assumed that rewriting requests are received from two or three of the four electronic paper displays 11 at approximately the same time. In such a case, the rewriting permission transmission unit 105 transmits rewriting permission according to the predetermined rewriting order. 【0036】 When rewrite permission is received from multiple electronic paper displays 11, for example, the rewrite permission transmission unit 105 sends rewrite permission to at least one electronic paper display 11 that is the source of the rewrite request, and after a predetermined time has elapsed, it determines whether the current in the power line is less than a threshold before sending rewrite permission to the other electronic paper displays 11 that are the source of the rewrite request. This is because the current in the power line increases when rewriting begins in the electronic paper display 11 from which rewrite permission was sent by the controller 10. The predetermined time is, for example, the time it takes from the receipt of rewrite permission until rewriting begins and the current increases. 【0037】 In addition, external power supply may be used in addition to the battery 12, or external power supply and the battery 12 may be used in combination. Figure 5 is an explanatory diagram showing an example of a control system 1 that further includes an external power supply 13. In the control system 1 in Figure 5, the external power supply 13 is further connected to the controller 10 compared to Figure 1. 【0038】Furthermore, the aforementioned threshold may be larger if there is an external power supply 13. When there is an external power supply 13, the allowable current increases, which may allow for an increase in the number of rewritable display pages. The same applies when the battery 12 and the external power supply 13 are supplying power simultaneously. 【0039】 Furthermore, the display information transmission unit 101 of the controller 10 may change the frequency of transmission of display information depending on whether or not there is an external power supply 13. For example, the display information transmission unit 101 of the controller 10 may increase the frequency of transmission of display information when there is an external power supply 13. On the other hand, for example, the display information transmission unit 101 of the controller 10 may decrease the frequency of transmission of display information when there is no external power supply 13. 【0040】 Furthermore, the display information transmission unit 101 of the controller 10 may change the frequency of transmission of display information according to the weather when there is external power supply 13 from solar power generation. When solar power generation is used, if it is sunny, there is external power supply 13, so the amount of current can be increased. For this reason, the display information transmission unit 101 of the controller 10 may increase the rewrite frequency when it is sunny. The display information transmission unit 101 of the controller 10 may decrease the rewrite frequency when it is cloudy compared to when it is sunny. The display information transmission unit 101 of the controller 10 may decrease the rewrite frequency when it is raining compared to when it is sunny or cloudy. 【0041】 (Sequence Diagram) Figure 6 is an explanatory diagram showing the sequence diagram of the control system 1. In Figure 6, an example is given in which electronic paper 11-1 and electronic paper 11-2 are connected to the controller 10. The threshold is the amount of current corresponding to the case where the number of electronic paper 11 that can be displayed and rewritten simultaneously is 1. That is, while electronic paper 11-1 is being rewritten, electronic paper 11-2 cannot be rewritten. 【0042】 In Figure 6, the display information transmission unit 101 of the controller 10 transmits its respective display information to each of the connected electronic paper displays 11 (step S101). 【0043】Then, the display information receiving unit 111 of the electronic paper 11-1 receives display information from the controller 10 (step S102). Similarly, the display information receiving unit 111 of the electronic paper 11-2 receives display information from the controller 10 (step S103). 【0044】 When the reception of the display information is completed, the request transmission unit 113 of the electronic paper 11-1 transmits a rewrite request to the controller 10 (step S104). Then, the request reception unit 103 of the controller 10 receives the rewrite request from the electronic paper 11-1 (step S105). 【0045】 Then, the rewrite permission transmission unit 105 of the controller 10 determines whether the current amount of the power line is less than the threshold value (step S106). Here, since two electronic papers 11 are connected to the controller 10 and no rewriting has been performed on any of the electronic papers 11, the current amount of the power line is less than the threshold value. Therefore, the rewrite permission transmission unit 105 of the controller 10 transmits a rewrite permission to the electronic paper 11-1 which is the transmission source of the rewrite request (step S107). Then, the rewrite permission receiving unit 115 of the electronic paper 11-1 receives the rewrite permission (step S108). 【0046】 Next, the rewriting unit 117 of the electronic paper 11-1 starts rewriting based on the received display information (step S109). As a result, since the power consumption of the electronic paper 11-1 increases, the current amount of the power line increases. 【0047】Next, when the request transmission unit 113 of the electronic paper 11-2 has completed receiving the display information, it transmits a rewrite request to the controller 10 (step S110). Then, the request reception unit 103 of the controller 10 receives the rewrite request from the electronic paper 11-2 (step S111). The rewrite permission transmission unit 105 of the controller 10 determines whether the current amount of the power line is less than the threshold value (step S112). Here, two electronic papers 11 are connected to the controller 10, and the electronic paper 11-1 is performing rewriting. Therefore, the current amount of the power line is greater than the threshold value. For this reason, the rewrite permission transmission unit 105 of the controller 10 makes a determination until the current amount of the power line becomes less than the threshold value. Note that the determination timing may be performed at predetermined intervals such as several seconds or several tens of seconds. 【0048】 After a while, the rewriting unit 117 of the electronic paper 11-1 finishes rewriting (step S113). Then, the current amount of the power line decreases. For this reason, in the above step S112, the rewrite permission transmission unit 105 of the controller 10 determines that the current amount of the power line is less than the threshold value. Then, the rewrite permission transmission unit 105 of the controller 10 transmits a rewrite permission to the electronic paper 11-1 which is the transmission source of the rewrite request (step S114). Then, the rewrite permission reception unit 115 of the electronic paper 11-2 receives the rewrite permission from the controller 10 (step S115). 【0049】 Next, the rewriting unit 117 of the electronic paper 11-2 starts rewriting based on the received display information (step S116). As a result, since the power consumption of the electronic paper 11-2 increases, the current amount of the power line increases. The description of the sequence diagram shown in FIG. 6 is completed above. 【0050】In the first embodiment described above, the controller 10 transmits display information to each of the multiple electronic paper displays 11. The controller 10 receives a rewrite request transmitted after it has finished receiving the display information from one of the multiple electronic paper displays 11. The controller 10 sends a rewrite permission to the electronic paper display 11 that sent the rewrite request, based on the result of comparing the amount of current flowing through the power lines supplying power to the multiple electronic paper displays 11 with a threshold corresponding to the number of electronic paper displays 11 that can be rewritten simultaneously. Specifically, for example, the controller 10 sends a rewrite permission to the source of the rewrite request when the amount of current flowing through the power lines supplying power to the multiple electronic paper displays 11 is less than the threshold corresponding to the number of electronic paper displays 11 that can be rewritten simultaneously. By dynamically monitoring the current consumption, it is easy to control the peak current consumption so that it does not become too high. Therefore, it is possible to equalize the peak current consumption due to rewriting. In addition, it is possible to efficiently switch the displays of multiple electronic paper displays 11 using limited resources such as the battery 12. Furthermore, even if the number of electronic paper displays 11 increases, it is possible to equalize the power consumption during rewriting. Therefore, it is not necessary to add new batteries or other components, and the expansion of electronic paper displays 11 can be simplified. Consequently, the costs associated with expansion can be reduced. In addition, by optimizing power management, the overall stability and reliability of the control system 1 can be improved. 【0051】 The rewriting order of multiple e-paper displays 11 is predetermined, and when the controller 10 receives rewriting requests from multiple e-paper displays 11, it may send a rewriting permission according to the rewriting order. This allows the e-paper displays 11 to be rewritten in sequence, so that, for example, one controller 10 can control the rewriting order of multiple e-paper displays 11. 【0052】 Furthermore, the threshold is determined based on the amount of current that the battery 12 can supply. This allows the controller 10 to determine the peak current consumption according to the capacity of the battery 12, thereby equalizing the peak current consumption due to rewriting. 【0053】 The controller 10 changes the transmission frequency depending on whether or not external power supply 13 is available and at least one of the weather conditions. In other words, the controller 10 can change the transmission frequency according to the power supply capacity. 【0054】 (Second Embodiment) The second embodiment will be described in detail with reference to the drawings. The second embodiment will describe a mechanism that reduces the amount of rewriting required. To the extent that the description of the second embodiment does not become unclear, explanations that overlap with the above description will be omitted. 【0055】 Since the example of the control system 1 including the controller may be the same as the example shown in Figures 1 and 5, the controller 10 shown in Figures 1 and 5 may be replaced with the controller 20, and the explanation of the example of the control system 1 including the controller will be omitted. 【0056】 Figure 7 is a block diagram showing one example configuration of the controller 20. In Figure 7, the controller 20 includes a display information transmission unit 201, a request reception unit 203, a rewrite permission transmission unit 205, a specification unit 207, and a selection unit 209. The controller 20 may, for example, store the results of various functional units in an internal or external storage unit of the controller 20. The controller 20 further includes a specification unit 207 and a selection unit 209 in addition to the functional units shown in Figure 1. 【0057】 For example, the display information transmission unit 201 has the functions of the display information transmission unit 101 shown in Figure 2 as its basic function. The request receiving unit 203 has the functions of the request receiving unit 103 shown in Figure 2 as its basic function. The rewrite permission transmission unit 205 has the functions of the rewrite permission transmission unit 105 shown in Figure 2 as its basic function. The request receiving unit 203 is the same as the processing described in the first embodiment, so a detailed explanation is omitted. 【0058】 Since there are no particular changes to the functional parts of the electronic paper 11, we will explain them using Figure 3. 【0059】Even with a single advertisement, there are cases where the displayed advertisement changes over time. In such cases, some electronic paper displays 11 may not show any change in the displayed information. Therefore, the identification unit 207 of the controller 20 identifies the difference between the current displayed information and the next displayed information for each of the multiple electronic paper displays 11. 【0060】 Then, the display information transmission unit 201 transmits the following display information to the electronic paper 11 that has a difference identified by the identification unit 207. 【0061】 In addition, advertisements may be displayed sequentially using multiple e-paper displays 11. There may be cases where the power supplied by the external power supply 13 is low or the power supply capacity of the battery 12 is low. In such cases, the advertisement may be selected from among multiple advertisements and displayed. 【0062】 The identification unit 207 identifies the difference between the current display information for each of the multiple electronic paper displays 11 and the display information for each of the multiple advertisements that are scheduled to be displayed. 【0063】 The selection unit 209 then selects the next advertisement to display from among multiple advertisements based on the difference between the current display information for each of the multiple electronic paper displays 11 and the display information for each of the multiple advertisements to be displayed. Specifically, for example, the selection unit 209 may select the next advertisement to display from among multiple advertisements based on the number of electronic paper displays 11 that need to be rewritten. More specifically, for example, the selection unit 209 selects the advertisement with the fewest number of electronic paper displays 11 that need to be rewritten as the next advertisement to display from among the multiple advertisements. Alternatively, for example, the selection unit 209 selects the advertisement with the smallest difference among the multiple electronic paper displays 11 as the next advertisement to display from among the multiple advertisements. In this way, when the power supply capacity is 035, the selection unit 209 should select advertisements that require fewer rewrites of the electronic paper displays 11. This makes it possible to keep power consumption low. 【0064】For example, if the power supply capacity is below a predetermined capacity, processing by the specific unit 207 and processing by the selection unit 209 may be performed. Specifically, for example, if the remaining charge of the battery 12 is low, processing by the specific unit 207 and processing by the selection unit 209 may be performed. Alternatively, for example, if an external power supply 13 such as solar power generation is used, processing by the specific unit 207 and processing by the selection unit 209 may be performed on a day with bad weather such as cloudy or rainy weather. The aforementioned predetermined number may be a predetermined number according to the weather, or a predetermined number according to the power supply capacity. 【0065】 The display information transmission unit 201 transmits display information about the selected advertisement to the electronic paper 11 where there is a difference regarding the selected advertisement. 【0066】 While this example shows an advertisement, the objects on which ads are displayed are not limited to advertisements. 【0067】 For example, let's briefly explain some examples of displays where the number of rewrites on the e-paper 11 is small. For instance, if a large advertisement of a face is displayed on multiple e-papers 11, and only the mouth is changed, the number of rewrites on the e-papers 11 is expected to be small. Similarly, if only a portion of a timetable is changed, the number of rewrites on the e-papers 11 is expected to be small. Furthermore, if only the date portion of an event announcement is changed, the number of rewrites on the e-papers 11 is expected to be small. As such, there are many displays where the number of rewrites on the e-papers 11 is small, so the displayed content may be changed as appropriate depending on the power supply capacity, etc. Also, as explained in the first embodiment, the rewrite frequency may be changed as appropriate depending on the power supply capacity. This makes it possible to reduce power consumption when multiple e-papers 11 are connected to the controller 20. 【0068】 Here, the identification process by the identification unit 207 and the selection process by the selection unit 209 should be performed before the process shown in step S101 in the sequence diagram shown in Figure 6. 【0069】(Flowchart) Figure 8 is a flowchart showing an example of the operation of the controller 20. The identification unit 207 identifies the difference between the current display information for each of the multiple electronic paper displays 11 and the display information for each of the multiple advertisements to be displayed (step S201). Next, the selection unit 209 selects the advertisement to be displayed next from the multiple advertisements based on the difference between the current display information for each of the multiple electronic paper displays 11 and the display information for each of the multiple advertisements to be displayed (step S202). Then, the display information transmission unit 201 transmits the display information for the selected advertisement to the electronic paper displays 11 where a difference exists for the selected advertisement (step S203). 【0070】 The request receiving unit 203 receives a rewrite request (step S204). The rewrite permission transmitting unit 205 determines whether the current in the power line is less than a threshold (step S205). If the current in the power line is greater than or equal to the threshold (step S205: No), the rewrite permission transmitting unit 205 returns to step S205. On the other hand, if the current in the power line is less than the threshold (step S205: Yes), the rewrite permission transmitting unit 205 transmits a rewrite permission (step S206). Then, the rewrite permission transmitting unit 205 determines whether it has transmitted a rewrite permission to all electronic paper displays 11 connected to the controller 20 (step S207). If a rewrite permission has not been transmitted to any of the electronic paper displays 11 connected to the controller 20 (step S207: No), the rewrite permission transmitting unit 205 returns to step S204. If a rewrite permission is sent to all electronic paper displays 11 connected to the controller 20 (step S207: Yes), the controller 20 terminates the series of processes shown in Figure 8. 【0071】 In the second embodiment described above, the controller 20 identifies the difference between the current display information and the next display information for each of the multiple electronic paper displays 11, and transmits the next display information to the electronic paper displays 11 that have a difference. This makes it possible to suppress rewriting of the electronic paper displays 11. Therefore, power consumption can be reduced. 【0072】Furthermore, the controller 20 selects the next advertisement to display from among multiple advertisements based on the difference between the current display information for each of the multiple electronic paper displays 11 and the display information for each of the multiple advertisements scheduled to be displayed. The controller 20 then transmits the display information for the selected advertisement to the electronic paper displays 11 that have a difference for the selected advertisement. For example, when the power supply capacity is low, the controller 20 can reduce power consumption by displaying advertisements with small differences. 【0073】 This concludes the description of the embodiments. Furthermore, the embodiments are not limited to the examples described above and can be modified in various ways. For example, the embodiments may be used in a modified form. Modifications are listed below. 【0074】 <Modification> In the first and second embodiments, the controllers 10 and 20 were described as having display information transmission units 101 and 201, request receiving units 103 and 203, rewrite permission transmission units 105 and 205, a specific unit 207, and a selection unit 209. Some of the functional units of the controllers 10 and 20 may be implemented by other devices. 【0075】 Figure 9 is an explanatory diagram showing an example of a control system 1 including a controller. The control system 1 shown in Figure 9 is the same as the control system 1 shown in Figure 5, but with the addition of a server 14. The edge terminal 15 is equipped with a controller 10, a battery 12, and an external power supply 13. The edge terminal 15 is connected to the server 14 via a wired or wireless communication network. 【0076】 For example, the controller 10 has the functional unit shown in Figure 2. The server 14 may have, for example, a specific unit 207 and a selection unit 209, and may also have a function to transmit display information to the edge terminal 15. This can reduce the processing load on the edge terminal 15. Therefore, the edge terminal 15 may use a controller 10 that can perform simple functions. 【0077】 This concludes the explanation of the modified examples. The modified examples and embodiments may be combined as appropriate. 【0078】Furthermore, the configuration of controllers 10 and 20 is not particularly limited. For example, the functional units of controllers 10 and 20 may be implemented by a single device. Alternatively, for example, each functional unit of controllers 10 and 20 or each database may be implemented by different devices and configured as a system. For example, the functional units of controllers 10 and 20 may be made up of multiple devices. As in the modified example, a system may be realized having a device that includes some of the functional units of controllers 10 and 20, and a device that includes other parts of the functional units of controllers 10 and 20. The number of devices is not particularly limited. 【0079】 (Example of computer hardware configuration) Next, we will describe an example of a hardware configuration when each device, such as controllers 10 and 20, server 14, and edge terminal 15, is implemented using a computer. 【0080】 Figure 10 is an explanatory diagram showing an example of a computer hardware configuration. For example, some or all of the devices such as controllers 10 and 20 and server 14 can be implemented using any combination of computer 80 and programs as shown in Figure 10. 【0081】 Computer 80 includes, for example, a processor 801, a ROM (Read Only Memory) 802, a RAM (Random Access Memory) 803, and a storage device 804. Computer 80 also includes a communication interface 805 and an input / output interface 806. Each component is connected, for example, via a bus 807. The number of components is not particularly limited, and each component may be one or more. 【0082】The processor 801 controls the entire computer 80. The processor 801 can be, for example, a CPU (Central Processing Unit), a DSP (Digital Signal Processor), a GPU (Graphics Processing Unit), a PPU (Physics Processing Unit), a TPU (Tensor Processing Unit), a quantum processor, or a combination thereof, and is not particularly limited. 【0083】 The computer 80 also includes a ROM 802, a RAM 803, and a storage device 804. The storage device 804 can be, for example, a semiconductor memory such as flash memory, an HDD (Hard Disk Drive), or an SSD (Solid State Drive). For example, the storage device 804 stores the OS (Operating System) program, application programs, and programs according to each embodiment. Alternatively, the ROM 802 stores application programs and programs according to the embodiment. The RAM 803 is used as a work area for the processor 801. 【0084】 The processor 801 also loads programs stored in the storage device 804, ROM 802, etc. Then, the processor 801 executes each process coded in the program. The processor 801 may also download various programs via the communication network NT. Furthermore, the processor 801 functions as part or all of the computer 80. The processor 801 may also execute processes or instructions in the illustrated flowchart based on the program. 【0085】The communication interface 805 is connected to a communication network NT, such as a LAN (Local Area Network) or WAN (Wide Area Network), via a wireless or wired communication line. The communication network NT may be composed of multiple communication networks NT. This allows the computer 80 to connect to external devices and external computers 80 via the communication network NT. The communication interface 805 manages the interface between the communication network NT and the internal workings of the computer 80. Furthermore, the communication interface 805 controls the input and output of data from external devices and external computers 80. 【0086】 Furthermore, the input / output interface 806 is connected to at least one of the input device, output device, and input / output device. The connection method may be wireless or wired. Examples of input devices include keyboards, mice, and microphones. Examples of output devices include display devices, lighting devices (such as lamps), and audio output devices. Examples of input / output devices include touch panel displays. The input device, output device, and input / output device may be built into the computer 80 or attached to the computer 80 externally. That is, for example, the computer 80 may have input devices such as keyboards and mice. The computer 80 may have output devices such as displays. The computer 80 may also have input devices, output devices, and input / output devices. 【0087】The hardware configuration of computer 80 is an example. Computer 80 may have some of the components shown in Figure 10. In particular, controllers 10 and 20 may have a simple hardware configuration. Computer 80 may have components other than those shown in Figure 10. For example, computer 80 may have a drive device. The processor 801 may read programs and data stored on a recording medium mounted on the drive device or the like into RAM 803. Examples of non-temporary tangible recording media include optical discs, flexible discs, magneto-optical discs, and USB (Universal Serial Bus) memory. 【0088】 This concludes the description of the hardware configuration of each device. Furthermore, there are various variations in how each device can be implemented. For example, each device may be implemented by any combination of different computers and programs for each component. Alternatively, the multiple components of each device may be implemented by any combination of a single computer and program. 【0089】 Furthermore, some or all of the components of each device may be implemented using application-specific circuits. Alternatively, some or all of the components of each device may be implemented using general-purpose circuits such as FPGAs (Field Programmable Gate Arrays). Furthermore, some or all of the components of each device may be implemented using a combination of application-specific circuits and general-purpose circuits. These circuits may also be a single integrated circuit, or they may be divided into multiple integrated circuits. These multiple integrated circuits may be connected via a bus or the like. 【0090】 Furthermore, if some or all of the components of each device are implemented by multiple computers or circuits, these computers or circuits may be centrally located or distributed. 【0091】 The control methods described in each embodiment may be implemented by a computer such as a controller 10. 【0092】 Each program described in each embodiment is recorded on a computer-readable recording medium such as an HDD, SSD, flexible disk, optical disk, magneto-optical disk, or USB memory. Each program is then executed by being read from the recording medium by a computer. Furthermore, each program may be distributed via a communication network NT. 【0093】 Each component of the controller 10 described above may be implemented using dedicated hardware, like a computer. Alternatively, each component may be implemented using software. Alternatively, each component may be implemented using a combination of hardware and software. 【0094】 Although the present disclosure has been described above with reference to embodiments, the present disclosure is not limited to the embodiments described above. The structure and details of the present disclosure may include embodiments that apply various modifications that can be grasped by those skilled in the art within the scope of the present disclosure. The present disclosure may include embodiments that combine or substitute the matters described herein as appropriate. For example, matters described using a particular embodiment may be applied to other embodiments to the extent that they do not cause a contradiction. For example, although several operations are described sequentially in the form of a flowchart, the order in which they are described does not limit the order in which the operations are performed. Therefore, when implementing an embodiment, the order of the operations can be changed to the extent that it does not impair the content. 【0095】 Some or all of the above embodiments may also be described as follows. However, some or all of the above embodiments are not limited to the following. 【0096】(Note 1) A control method that performs the following process: a controller connected to and controlling a plurality of electronic paper displays transmits display information to at least some of the plurality of electronic paper displays; receives a rewrite request transmitted after the reception of the display information has been completed from at least some of the electronic paper displays; and transmits a rewrite permission to the electronic paper that sent the rewrite request, according to the result of comparing the amount of current flowing through the power lines supplying power to the plurality of electronic paper displays with a threshold corresponding to the number of electronic paper displays that can be rewritten simultaneously. 【0097】 (Note 2) The control method described in Note 1, wherein in the process of transmitting the rewrite permission, the rewrite permission is transmitted to the source of the rewrite request when the amount of current flowing through the power line is less than a threshold corresponding to the number of electronic paper displays that can be rewritten simultaneously. 【0098】 (Note 3) The control method described in Note 1 or 2, wherein the rewriting order of the plurality of electronic paper is predetermined, and in the process of transmitting the rewriting permission, when the rewriting request is received from multiple electronic paper among the plurality of electronic paper, the rewriting permission is transmitted according to the rewriting order. 【0099】 (Note 4) The control method described in any of Notes 1 to 3, wherein the threshold is determined based on the amount of current that the battery can supply. 【0100】 (Note 5) The control method described in any of Notes 1 to 4, wherein the process of transmitting the display information changes the transmission frequency based on at least one of the presence or absence of external power supply and the weather. 【0101】 (Note 6) The control method according to any one of Notes 1 to 5, wherein the controller performs a process to identify the difference between the current display information and the next display information for each of the plurality of electronic paper displays, and in the process of transmitting the display information, transmits the next display information to the electronic paper display that has the difference. 【0102】(Note 7) The control method described in Note 6, wherein the controller performs a process to select the next advertisement to be displayed from the multiple advertisements based on the difference between the current display information and the display information of each of the multiple advertisements to be displayed for each of the multiple electronic paper displays, and in the process of transmitting the display information, transmits the display information for the selected advertisement to the electronic paper display where a difference exists for the selected advertisement. 【0103】 (Note 8) The control method described in Note 7, wherein the selection process involves selecting the next advertisement to be displayed from the multiple advertisements based on the number of electronic paper pages that need to be rewritten. 【0104】 (Note 9) A controller connected to and controlling a plurality of electronic paper displays, comprising: display information transmission means for transmitting display information to at least some of the plurality of electronic paper displays; request receiving means for receiving a rewrite request transmitted after the reception of the display information from any of the at least some of the electronic paper displays is complete; and rewrite permission transmission means for transmitting rewrite permission to the electronic paper that sent the rewrite request, according to the result of comparing the amount of current flowing through a power line that supplies power to the plurality of electronic paper displays with a threshold value corresponding to the number of electronic paper displays that can be rewritten simultaneously. 【0105】(Note 10) A control system comprising: a controller connected to a plurality of electronic paper and controlling the plurality of electronic paper; the plurality of electronic paper, wherein the controller comprises: display information transmission means for transmitting display information to at least some of the plurality of electronic paper; request receiving means for receiving a rewrite request transmitted after the reception of the display information from any of the at least some of the electronic paper is complete; rewrite permission transmission means for transmitting rewrite permission to the electronic paper that sent the rewrite request, according to the result of comparing the amount of current flowing through a power line that supplies power to the plurality of electronic paper with a threshold corresponding to the number of electronic paper that can be rewritten simultaneously; and each of the plurality of electronic paper comprises: display information receiving means for receiving the display information from the controller; request transmission means for transmitting a rewrite permission request to the controller when the reception of the display information is complete; rewrite permission receiving means for receiving rewrite permission from the controller; and rewrite means for performing rewriting based on the received display information when rewrite permission is received from the controller. 【0106】 (Note 11) A non-temporary recording medium readable by the controller, which is connected to a plurality of electronic paper displays and records a program that causes the controller to control the plurality of electronic paper displays to transmit display information to at least some of the plurality of electronic paper displays, receive a rewrite request transmitted after the reception of the display information from at least some of the electronic paper displays is complete, and transmit rewrite permission to the electronic paper that sent the rewrite request, according to the result of comparing the amount of current flowing through the power lines that supply power to the plurality of electronic paper displays with a threshold corresponding to the number of electronic paper displays that can be rewritten simultaneously. 【0107】(Note 12) A program that causes a controller connected to a plurality of electronic paper displays to control the plurality of electronic paper displays to perform the following processes: transmit display information to at least some of the plurality of electronic paper displays; receive a rewrite request transmitted after the reception of the display information from at least some of the electronic paper displays is complete; and transmit rewrite permission to the electronic paper that sent the rewrite request, according to the result of comparing the amount of current flowing through the power lines that supply power to the plurality of electronic paper displays with a threshold corresponding to the number of electronic paper displays that can be rewritten simultaneously. 【0108】 (Note 13) An electronic paper which is one of a plurality of electronic paper connected to a controller, comprising: a display information receiving means for receiving display information from the controller; a transmitting means for sending a rewrite request to the controller when the reception of the display information is complete; and a control means for starting a rewrite based on the received display information when the controller grants permission to rewrite. 【0109】 (Note 14) A method comprising: one of several electronic paper displays connected to a controller receives display information from the controller, sends a rewrite request to the controller when the reception of the display information is complete, and starts rewriting based on the received display information when permission to rewrite is received from the controller. 【0110】 Furthermore, some or all of the configurations described in Appendices 2 to 8, which are dependent on Appendice 1 above, may also be dependent on Appendices 9, 10, 11, and 12 in the same way as those described in Appendices 2 to 8. Moreover, not limited to Appendices 1, 9, 10, 11, 12, 13, and 14, some or all of the configurations described as appendices may also be dependent on various hardware, software, various recording means for recording software, or systems, without departing from the embodiments described above. 【0111】1 Control system 10, 20 Controller 11, 11-1, 11-2 Electronic paper 12 Battery 13 External power supply 14 Server 15 Edge terminal 80 Computer 101, 201 Display information transmission unit 103, 203 Request reception unit 105, 205 Rewrite permission transmission unit 207 Identification unit 209 Selection unit 111 Display information reception unit 113 Request transmission unit 115 Rewrite permission transmission unit 117 Rewrite unit 801 Processor 802 ROM 803 RAM 804 Storage device 805 Communication interface 806 Input / output interface 807 Bus NT Communication network
Claims
1. A control method that performs the following process: a controller connected to and controlling multiple electronic paper displays transmits display information to at least some of the multiple electronic paper displays; receives a rewrite request transmitted after the reception of the display information has been completed from at least some of the electronic paper displays; and transmits a rewrite permission to the electronic paper that sent the rewrite request, based on the result of comparing the amount of current flowing through the power lines supplying power to the multiple electronic paper displays with a threshold corresponding to the number of electronic paper displays that can be rewritten simultaneously.
2. The control method according to claim 1, wherein in the process of transmitting the rewrite permission, the rewrite permission is transmitted to the source of the rewrite request when the amount of current flowing through the power line is less than a threshold corresponding to the number of electronic paper displays that can be rewritten simultaneously.
3. The control method according to claim 1 or 2, wherein the rewriting order of the plurality of electronic paper is predetermined, and in the process of transmitting the rewriting permission, when the rewriting request is received from a plurality of the plurality of electronic paper, the rewriting permission is transmitted according to the rewriting order.
4. The control method according to any one of claims 1 to 3, wherein the threshold is determined based on the amount of current that the battery can supply.
5. The control method according to any one of claims 1 to 4, wherein the process of transmitting the display information changes the transmission frequency based on at least one of the presence or absence of external power supply and the weather.
6. The control method according to any one of claims 1 to 5, wherein the controller performs a process to identify the difference between the current display information and the next display information for each of the plurality of electronic paper displays, and in the process of transmitting the display information, transmits the next display information to the electronic paper display that has the difference.
7. The control method according to claim 6, wherein the controller performs a process to select the next advertisement to be displayed from the plurality of advertisements based on the difference between the current display information and the display information of each of the plurality of advertisements to be displayed for each of the plurality of electronic paper displays, and in the process of transmitting the display information, transmits the display information for the selected advertisement to the electronic paper display where a difference exists for the selected advertisement.
8. The control method according to claim 7, wherein the selection process selects the next advertisement to be displayed from the plurality of advertisements based on the number of electronic paper displays that need to be rewritten.
9. A controller connected to and controlling a plurality of electronic paper displays, comprising: display information transmission means for transmitting display information to at least some of the plurality of electronic paper displays; request receiving means for receiving a rewrite request transmitted after the reception of the display information from any of the at least some of the electronic paper displays is complete; and rewrite permission transmission means for transmitting rewrite permission to the electronic paper that sent the rewrite request, according to the result of comparing the amount of current flowing through a power line supplying power to the plurality of electronic paper displays with a threshold value corresponding to the number of electronic paper displays that can be rewritten simultaneously.
10. A control system comprising: a controller connected to and controlling a plurality of electronic paper; the plurality of electronic paper; the controller comprising: display information transmission means for transmitting display information to at least some of the plurality of electronic paper; request receiving means for receiving a rewrite request transmitted after the reception of the display information from any of the at least some of the electronic paper is complete; rewrite permission transmission means for transmitting rewrite permission to the electronic paper that sent the rewrite request, according to the result of comparing the amount of current flowing through a power line supplying power to the plurality of electronic paper with a threshold corresponding to the number of electronic paper that can be rewritten simultaneously; and each of the plurality of electronic paper comprising: display information receiving means for receiving the display information from the controller; request transmission means for transmitting the rewrite request to the controller when the reception of the display information is complete; rewrite permission receiving means for receiving rewrite permission from the controller; and rewrite means for performing rewriting based on the received display information when rewrite permission is received from the controller.
11. A non-temporary recording medium readable by the controller, which is connected to a plurality of electronic paper displays and records a program that causes the controller to control the plurality of electronic paper displays to perform the following processes: transmit display information to at least some of the plurality of electronic paper displays; receive a rewrite request transmitted after the reception of the display information from any of the at least some of the electronic paper displays is complete; and transmit rewrite permission to the electronic paper that sent the rewrite request, according to the result of comparing the amount of current flowing through the power lines supplying power to the plurality of electronic paper displays with a threshold corresponding to the number of electronic paper displays that can be rewritten simultaneously.