JP2009276635A - Display method, display device and display system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a display method for preventing occurrence of display irregularity of a display device having memory performance, a display device and a display system. <P>SOLUTION: A CPU 111 of an electronic shelf label 1 stores plotting information received from an electronic shelf label server through an RF 116 in a RAM 113. Then, it transmits an on-signal to an LCD power supply circuit 13 through an I/O 117, drives a COMMON driver 17 and a SEGMENT driver 18 to display the plotting information on a cholesteric LCD 16, and then transmits an off-signal to the LCD power supply circuit 13 through the I/O 117, and stops drive by the COMMON driver 17 and the SEGMENT driver 18. The CPU 111 monitors temperature informed from a temperature sensor 14 through an ADC 115, reads out the plotting information from the RAM 113 if variation of temperature exceeds the predetermined one, and displays the read-out plotting information on the cholesteric LCD 16 again. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a display method, a display device, and a display system for displaying display information such as product information on a display having a memory property.

  In an electronic shelf label system, a shelf label server is installed in a store backyard, etc., a base station that is a repeater, a store server that manages product information, sales information, order information, etc. A POS (Point Of Sales) terminal that performs sales processing is connected by a LAN (Local Area Network). The shelf label server acquires information about the product from the store server, for example, information such as product name, product code, sales price, unit price and special price information, creates display information to be displayed on the electronic shelf label based on the acquired information, The created display information is transmitted to the electronic shelf label via the base station and the transceiver.

  The base station has a function of controlling transmission / reception of data between the shelf label server and the transceiver and a function of communicating with the electronic shelf label as a transceiver. The transceiver has a function of transmitting / receiving data to / from the electronic shelf label. The electronic shelf label receives commands and data from the transceiver and displays display information about the product.

  A display device such as an electronic shelf label uses a liquid crystal display element having a memory property, for example, a cholesteric liquid crystal. A cholesteric liquid crystal is a device that performs display using two different molecular orientations due to phase transition, and can maintain a state in which information is displayed even when power supply is stopped. The liquid crystal molecules of the cholesteric liquid crystal have a helical shape, and selective reflection, that is, light of a specific wavelength is reflected by this helical shape. The state of the helical axis includes a planar state and a focal conic state. The planar state is a state in which the helical axis is directed toward the display surface, and reflects light having a specific wavelength. The focal conic state is a state in which a voltage is applied and the spiral axis is oriented in a direction to lie on the display surface, and light is transmitted through the cell.

  The cholesteric liquid crystal maintains the state of the helical axis even when the application of voltage is stopped. However, cholesteric liquid crystals cause strain stress due to the difference in coefficient of thermal expansion of the constituent layers of the liquid crystal due to a rapid temperature change, etc., which disturbs the molecular alignment of the liquid crystal, that is, the liquid crystal's helical axis is disturbed, resulting in uneven display. May occur. In order to eliminate the display unevenness that has occurred, it is necessary to redraw.

  The information display device described in Patent Document 1 rewrites image data at a predetermined time interval measured by a timer or at a predetermined time or when the temperature detected by the temperature sensor exceeds a predetermined value. This prevents the occurrence of display unevenness.

JP 2000-147465 A

  However, the information display device according to the conventional technique described above rewrites data when the temperature detected by the temperature sensor exceeds a predetermined value, but the display unevenness does not occur in a high temperature environment. When it occurs due to temperature change, there is a problem that display unevenness cannot be prevented. In addition, this information display device periodically rewrites data, but regularly consumes power, so electronic shelf labels driven mainly by batteries increase the frequency of battery replacement and increase the burden on the user. There is a problem of doing.

  An object of the present invention is to provide a display method, a display device, and a display system that can prevent the occurrence of display unevenness of a display having a memory property.

The present invention is a display method for displaying display information on a display unit of a display device including a display unit capable of holding display information displayed in a driving state in a non-driving state,
A display step of displaying display information with the display unit in a driven state, and then holding the display information with the display unit in a non-driven state;
A temperature detecting step for detecting the temperature of the display unit;
A calculation step for calculating a change amount of the temperature based on the temperature detected in the temperature detection step;
A determination step of determining whether or not the temperature change amount calculated in the calculation step exceeds a predetermined change amount;
In the determination step, when it is determined that the temperature change amount calculated in the calculation step exceeds a predetermined change amount, the same display information as the display information displayed on the display unit in the display step is displayed on the display unit. And a redisplay step of displaying.

The present invention also includes a storage means for storing display information;
Display means capable of holding display information displayed in a driving state in a non-driving state;
Temperature detecting means for detecting the temperature of the display means;
Calculation means for calculating a change in temperature based on the temperature detected by the temperature detection means;
Determining means for determining whether or not the amount of change in temperature calculated by the calculating means exceeds a predetermined amount of change;
The display information stored in the storage means is read out, the read display information is displayed with the display means in a driving state, and the display information is held in a non-driving state, and then the determination is made. When it is determined by the means that the amount of change in temperature calculated by the calculating means exceeds a predetermined amount of change, the same display information as the display information displayed on the display means is read from the storage means and read out. And a control means for displaying display information on the display means.

The present invention also includes a management device that stores display information and display means that can hold display information displayed in a driving state in a non-driving state, obtains display information from the management device, and displays the acquired display information. A display system including a display device for displaying on the display means,
The display device
Temperature detecting means for detecting the temperature of the display means;
Calculation means for calculating a change in temperature based on the temperature detected by the temperature detection means;
Determining means for determining whether or not the amount of change in temperature calculated by the calculating means exceeds a predetermined amount of change;
The display information stored in the storage means is read out, the read display information is displayed with the display means in a driving state, and the display information is held in a non-driving state, and then the determination is made. When it is determined by the means that the change amount of the temperature calculated by the calculation means exceeds a predetermined change amount, the same display information as the display information displayed on the display means is acquired from the management device and acquired. The display system further includes control means for causing the display means to display the displayed information.

  According to the present invention, when displaying the display information on the display unit of the display device including the display unit capable of holding the display information displayed in the driving state in the non-driving state, the display unit is set in the driving state in the display step. After displaying the display information, the display unit is set in a non-driven state to hold the display information. In the temperature detection step, the temperature of the display unit is detected. In the calculating step, a temperature change amount is calculated based on the temperature detected in the temperature detecting step. In the determination step, it is determined whether or not the temperature change amount calculated in the calculation step exceeds a predetermined change amount. In the redisplay step, when it is determined in the determination step that the amount of change in temperature calculated in the calculation step exceeds a predetermined amount of change, the same display information displayed on the display unit in the display step Display information is displayed on the display unit.

  Therefore, by applying the display method according to the present invention, it is possible to prevent display unevenness of a display having a memory property. The drawing information is redisplayed only when the temperature change amount exceeds the specified change amount and there is a high possibility that display unevenness has occurred, so unnecessary rewriting can be eliminated and the battery life can be maximized. Can be extended. Therefore, it is not necessary for the user of the display device to check for display unevenness, and the number of battery replacements can be reduced, so that the burden on the user can be reduced.

  According to the invention, the display information is stored by the storage means, the display information displayed in the driving state is held in the non-driven state by the display means, and the temperature of the display means is detected by the temperature detecting means. The calculation unit calculates a temperature change amount based on the temperature detected by the temperature detection unit, and the determination unit determines whether the temperature change amount calculated by the calculation unit exceeds a predetermined change amount. Is judged.

  Then, the display information stored in the storage means is read out by the control means, the read display information is displayed with the display means in a driving state, and the display means is in a non-driving state. The display information that is the same as the display information displayed on the display unit when the determination unit determines that the change amount of the temperature calculated by the calculation unit exceeds a predetermined change amount after holding the display information. Is read from the storage means, and the read display information is displayed on the display means.

  Accordingly, it is possible to prevent display unevenness of a display having a memory property. The drawing information is redisplayed only when the temperature change amount exceeds the specified change amount and there is a high possibility that display unevenness has occurred, so unnecessary rewriting can be eliminated and the battery life can be maximized. Can be extended. Therefore, it is not necessary for the user of the display device to check for display unevenness, and the number of battery replacements can be reduced, so that the burden on the user can be reduced.

  Further, according to the present invention, the management apparatus that stores the display information and the display unit that can hold the display information displayed in the driving state in the non-driving state, the display information is acquired from the management apparatus, and the acquired display In a display system including a display device that displays information on the display means, when displaying display information on the display means, the temperature of the display means is detected by the temperature detection means in the display device, and the calculation means The temperature change amount is calculated based on the temperature detected by the temperature detection means, and the determination means determines whether or not the temperature change amount calculated by the calculation means exceeds a predetermined change amount. .

  In the display device, the display information stored in the storage unit is further read out by the control unit, the read display information is displayed with the display unit in a driving state, and the display unit After holding the display information in a non-driven state, when the determination means determines that the amount of change in temperature calculated by the calculation means exceeds a predetermined change amount, the display means displays the display information. The same display information as the displayed display information is acquired from the management apparatus, and the acquired display information is displayed on the display means.

  Accordingly, it is possible to prevent display unevenness of a display having a memory property. The drawing information is redisplayed only when the temperature change amount exceeds the specified change amount and there is a high possibility that display unevenness has occurred, so unnecessary rewriting can be eliminated and the battery life can be maximized. Can be extended. Therefore, it is not necessary for the user of the display device to check for display unevenness, and the number of battery replacements can be reduced, so that the burden on the user can be reduced. Furthermore, since it is not necessary to mount a memory for storing display information on the electronic shelf label, the electronic shelf label can be miniaturized and the product cost can be reduced.

  FIG. 1 is a block diagram showing a configuration of an electronic shelf label 1 according to an embodiment of the present invention. The display method according to the present invention is executed by the electronic shelf label 1. An electronic shelf label 1 as a display device includes a control integrated circuit (hereinafter referred to as “IC”) 11, a battery 12, a liquid crystal display (hereinafter referred to as “LCD”) power supply circuit 13, a temperature sensor 14, and an antenna. 15 includes a cholesteric liquid crystal (hereinafter referred to as “cholesteric LCD”) 16, a COMMON driver 17, and a SEGMENT driver 18.

The control IC 11 includes a central processing unit (hereinafter referred to as “CPU”) 111, a ROM (Read Only Memory) 112, a RAM (Random Access Memory) 113, an RTC (Real Time Clock) 114, an analog-digital converter (Analog). Digital
Converter (hereinafter referred to as “ADC”) 115, RF (Radio Frequency) 116, and I / O (Input / Output) 117, for example, is configured by a one-chip microcomputer including these components.

  The CPU 111 serving as a calculation unit, a determination unit, and a control unit controls the ADC 115, the RF 116, and the I / O 117 by executing a control program stored in the ROM 112 or the RAM 113. The ROM 112 is configured by, for example, a read-only nonvolatile semiconductor memory, and stores a control program executed by the CPU 111. The RAM 113 serving as a storage unit and storage means is configured by a writable and readable semiconductor memory, and stores a control program executed by the CPU 111 and control information that the CPU 111 performs writing and reading, such as drawing information and temperature information. The drawing information that is display information is information related to the product on which the electronic shelf label 1 is placed, and includes information such as the product name and price. The temperature information is information related to the temperature detected by the temperature sensor 13.

  The RTC 114 is a timer that measures time, and the CPU 111 can know the time by referring to the RTC 114. The ADC 115 is an analog-to-digital converter that converts an analog signal representing the temperature detected by the temperature sensor 14 into a digital signal and sends the digital signal to the CPU 111. The ADC 115 supplies power supplied from the battery 12 to the CPU 111, ROM 112, RAM 113, RTC 114, RF 116, and I / O 117.

  The RF 116 is a communication device that transmits / receives information to / from an electronic shelf label server (not shown) via the antenna 15, transmits information received from the CPU 111 to the electronic shelf label server, and sends information received from the electronic shelf label server to the CPU 11. The I / O 117 is an input / output control device that is connected to the LCD power supply circuit 13, the COMMON driver 17, and the SEGMENT driver 18 and controls the LCD power supply circuit 13, the COMMON driver 17, and the SEGMENT driver 18 in accordance with instructions from the CPU 111.

  The battery 12 is constituted by a direct current battery such as a rechargeable battery having an output voltage of 3 V (volt), and supplies power to the ADC 115 and the LCD power supply circuit 13. The LCD power supply circuit 13 is a voltage conversion circuit that boosts the voltage supplied from the battery 12 to a voltage necessary for driving the cholesteric LCD 16, for example, 37V. The LCD power supply circuit 13 turns on / off the voltage output to the COMMON driver 17 and the SEGMENT driver 18 based on an on / off signal instructed from the CPU 111 via the I / O 117. The temperature sensor 14 serving as temperature detection means is a temperature sensor that detects the temperature of the cholesteric LCD 16 or the temperature in the electronic shelf label 1, and sends an analog signal representing the detected temperature to the ADC 115. The antenna 15 is connected to the RF 116 and transmits and receives radio waves in order to transmit and receive information to and from an electronic shelf label server (not shown).

  A cholesteric LCD 16 serving as a display unit and display means is a display having a memory property, for example, a display using cholesteric liquid crystal. A display having a memory property is a display capable of holding drawing information displayed in a driving state in a non-driving state. For example, even when a voltage applied to the display is turned off, the drawing information being displayed is held. It is a display that can. In the cholesteric liquid crystal, the direction of the helical liquid crystal molecules changes due to temperature change, and display unevenness occurs. When display unevenness occurs, display unevenness can be eliminated by displaying the same drawing information again. In the example shown in FIG. 1, a cholesteric liquid crystal is used as a display having a memory property, but the present invention is not limited to this. For example, a powder type display may be used.

  The COMMON driver 17 and the SEGMENT driver 18 are drivers that are driven by applying a voltage to the cholesteric LCD 16 in accordance with an instruction from the CPU 111 via the I / O 117. The COMMON driver 17 drives the horizontal direction of the matrix of the cholesteric LCD 16, and drives the vertical direction of the matrix of the SEGMENT driver 18 cholesteric LCD 16.

  FIG. 2 is a diagram showing an example of the drawing information displayed on the cholesteric LCD 16. FIG. 2 shows the appearance of the electronic shelf label 1, and shows an antenna 15 and a cholesteric LCD 16. The display screen of the cholesteric LCD 16 shown in FIG. 2 displays drawing information, specifically, the product name “natural material unbleached coffee”, the price “1,680 yen”, and other information related to the product. .

  The CPU 111 stores the drawing information received from the electronic shelf label server (not shown) via the RF 116 in the RAM 113. Then, an ON signal is sent to the LCD power supply circuit 13 via the I / O 117, the COMMON driver 17 and the SEGMENT driver 18 are driven to display drawing information on the cholesteric LCD 16, and then the LCD power supply circuit 13 via the I / O 117. An OFF signal is sent to, and driving by the COMMON driver 17 and the SEGMENT driver 18 is stopped. Since the cholesteric LCD 16 has a memory property, it continues to display the displayed drawing information.

  The CPU 111 monitors the temperature notified from the temperature sensor 14 via the ADC 115, and if the amount of change in temperature exceeds a predetermined amount of change, display unevenness may occur. Reading and drawing information are displayed again on the cholesteric LCD 16. Specifically, an on signal is sent to the LCD power supply circuit 13 through the I / O 117, the COMMON driver 17 and the SEGMENT driver 18 are driven, and the read drawing information is displayed on the cholesteric LCD 16, and then through the I / O 117. Then, an off signal is sent to the LCD power supply circuit 13 to stop driving by the COMMON driver 17 and the SEGMENT driver 18.

  FIG. 3 is a diagram illustrating an example of the amount of change in temperature that is a condition for redisplay. FIG. 3A shows an example in which a temperature gradient is used as the temperature change amount. The temperature gradient is a temperature change rate indicated by a value obtained by dividing a temperature change when a predetermined time elapses by the predetermined time. The CPU 111 performs re-display when the temperature gradient exceeds a predetermined temperature gradient. FIG. 3B shows an example in which a temperature difference is used as the amount of change in temperature. The temperature difference is a difference between a temperature when starting to measure a predetermined time and a temperature when a predetermined time has elapsed. The CPU 111 performs re-display when the temperature difference exceeds a predetermined temperature difference. FIG. 3C shows an example in which the integrated value of the temperature change is used as the temperature change amount. The integrated value of the temperature change is a value obtained by integrating the absolute value of the temperature difference at each predetermined time every predetermined time. The CPU 111 performs re-display when the integrated value of the temperature change exceeds a predetermined integrated value.

  As described above, since the change amount of the temperature is a temperature gradient, display unevenness due to a sudden change can be prevented even if there is no large temperature change.

  Further, since the temperature change is a temperature difference, display unevenness due to a large temperature change can be prevented even if the temperature gradient is low.

  Further, since the temperature change amount is an integrated amount of temperature change, display unevenness due to accumulation of temperature change can be prevented.

  FIG. 4 is a flowchart showing display processing executed by the CPU 111. Drawing information is received via an RF 116 from an electronic shelf label server (not shown), and the received drawing information is stored in the RAM 113. Then, the process proceeds to step A1.

  In step A1, drawing information is called. Specifically, drawing information is read from the RAM 113. In step A2, the screen is drawn. Specifically, an ON signal is sent to the LCD power supply circuit via the I / O 117, the COMMON driver 17 and the SEGMENT driver 18 are driven, and the read drawing information is displayed on the cholesteric LCD 16, and then via the I / O 117. An off signal is sent to the LCD power supply circuit, and driving by the COMMON driver 17 and the SEGMENT driver 18 is stopped.

  In step A3, variables are initialized. Specifically, “0” is substituted into the variable n. In step A4, an initial temperature is acquired. Specifically, the current temperature is acquired from the temperature sensor 14 via the ADC 115 and set as the initial temperature. In step A5, the acquisition result is substituted into the variable α. The variable α is a temperature immediately after displaying the drawing information, and is a reference temperature for obtaining the amount of change in temperature.

  In step A6, a predetermined time is waited. That is, it waits for a predetermined time to elapse. The predetermined time is a time set between 30 minutes and several hours, for example, 2 hours. In step A7, it is determined whether or not there is data in the variable n. If the value of the variable n is not “0”, it is determined that there is data in the variable n, and the process proceeds to step A8. If the value of the variable n is “0”, it is determined that there is no data in the variable n, and step A21 Proceed to

  In step A8, the current temperature is acquired. Specifically, the current temperature is acquired from the temperature sensor 14 via the ADC 115. In step A9, the obtained result is substituted for variable n + 1. In step A10, the absolute value of the value obtained by subtracting the value of the variable n from the value of the variable n + 1 is calculated. In Step A11, the calculation result, that is, the absolute value calculated in Step A10 is substituted into the variable γ. The variable γ is a variable indicating a temperature gradient. In step A12 as a determination step, it is determined whether or not the variable γ, that is, the temperature gradient exceeds “5”. If the variable γ exceeds “5”, the process proceeds to step A16. If the variable γ does not exceed “5”, the process proceeds to step A13. The temperature gradient “5” is a predetermined amount of change.

  In step A13, it is determined whether or not it is in a rewriting preparation state. The rewriting preparation state indicates that the integrated value of the temperature change exceeds the threshold value. In the rewriting preparation state, for example, information indicating that the rewriting preparation state is stored in the RAM 113, and by referring to the information, it can be determined whether or not the rewriting preparation state. In step A13, when the temperature gradient becomes smaller than “5”, that is, when the temperature change is stabilized, it is determined whether or not the integrated value of the temperature change exceeds the threshold value. If it is in the rewriting ready state, the process proceeds to step A14. If it is not in the rewriting ready state, the process proceeds to step A17.

  In step A14, drawing information is called. Specifically, drawing information is read from the RAM 113. In step A15, the screen is redrawn and the process returns to step A3. Specifically, an on signal is sent to the LCD power supply circuit 13 through the I / O 117, the COMMON driver 17 and the SEGMENT driver 18 are driven, and the read drawing information is displayed on the cholesteric LCD 16, and then through the I / O 117. Then, an off signal is sent to the LCD power supply circuit 13, the drive by the COMMON driver 17 and the SEGMENT driver 18 is stopped, and the process returns to step A3.

  In step A16, the value of variable γ is added to the value of variable β. The variable β is a variable indicating the integrated value of the temperature change. In step A17, the value of variable γ is added to the value of variable β. When the variable γ, that is, the temperature gradient exceeds “5”, since a rapid temperature change has occurred, the weight is doubled as an integrated value of the temperature change. In step A18, the value of variable n + 1 is substituted for variable n. In step A19, it is determined whether or not the value of the variable β is greater than or equal to a threshold value. The threshold value, which is a predetermined amount of change, depends on the initial temperature acquired in step A4, but is a value of about 20 degrees, for example. If the value of the variable β is equal to or greater than the threshold value, the process proceeds to step A20. If the value of the variable β is not equal to or greater than the threshold value, the process returns to step A6. In step A20, the rewrite preparation state is set, and the process returns to step A6.

  In step A21, the current temperature is acquired. Specifically, the current temperature is acquired from the temperature sensor 14 via the ADC 115. In step A22, the acquisition result is substituted for variable n. In step A23, the absolute value of the value obtained by subtracting the value of the variable α from the value of the variable n is calculated. In step A24, the calculation result, that is, the absolute value calculated in step A23 is substituted into the variable β, and the process proceeds to step A19.

  Steps A1 and A2 are display steps. Steps A4, A8, and A21 are temperature detection steps. Steps A10, A16, A17, and A23 are calculation steps. Steps A14 and A15 are redisplay steps. Steps A12 and A13 are second determination steps.

  As described above, when displaying the drawing information on the cholesteric LCD 16 of the electronic shelf label 1 including the cholesteric LCD 16 capable of holding the display information displayed in the driving state in the non-driving state, in steps A1 and A2 shown in FIG. After the LCD 16 is driven to display the drawing information, the cholesteric LCD 16 is not driven to hold the drawing information. In steps A4, A8, and A21 shown in FIG. 4, the temperature of the cholesteric LCD 16 is detected. In steps A10, A16, A17, and A23 shown in FIG. 4, the temperature change amount is calculated based on the temperatures detected in steps A4, A8, and A21 shown in FIG. In step A12 shown in FIG. 4, it is determined whether or not the amount of change in temperature calculated in steps A10, A16, A17, and A23 shown in FIG. 4 exceeds a predetermined amount of change. In steps A14 and A15 shown in FIG. 4, the amount of change in temperature calculated in steps A10, A16, A17, and A23 shown in FIG. 4 exceeds the predetermined change amount in step A12 shown in FIG. When it is determined that the drawing information is the same as the drawing information displayed on the cholesteric LCD 16 in steps A1 and A2 shown in FIG.

  Therefore, by applying the display method according to the present invention, it is possible to prevent display unevenness of a display having a memory property, for example, cholesteric LCD 16. The drawing information is redisplayed only when the temperature change amount exceeds the specified change amount and there is a high possibility that display unevenness has occurred, so unnecessary rewriting can be eliminated and the battery life can be maximized. Can be extended. Therefore, it is not necessary for the user of the display device to check for display unevenness, and the number of battery replacements can be reduced, so that the burden on the user can be reduced.

  Furthermore, the electronic shelf label 1 further includes a RAM 113 that stores drawing information to be displayed on the cholesteric LCD 16. In steps A14 and A15 shown in FIG. 4, the drawing information stored in the RAM 113 is read out, and the read drawing information is read out. Is displayed on the cholesteric LCD 16, display unevenness can be prevented with the electronic shelf label 1 alone, and the load on an electronic shelf label server (not shown) can be reduced.

  Further, in steps A12 and A13 shown in FIG. 4, the amount of change in temperature calculated in steps A10, A16, A17, and A23 shown in FIG. 4 exceeds the predetermined change amount in step A12 shown in FIG. After that, it is determined whether or not the temperature change amount calculated in steps A10, A16, A17, and A23 shown in FIG. 4 is equal to or less than the predetermined change amount. In steps A14 and A15 shown in FIG. 4, the amount of change in temperature calculated in steps A10, A16, A17, and A23 shown in FIG. 4 exceeds the predetermined change amount in step A12 shown in FIG. 4, it is determined in steps A12 and A13 shown in FIG. 4 that the amount of change in temperature calculated in steps A10, A16, A17, and A23 shown in FIG. 4 is less than or equal to the predetermined amount of change. In this case, since the same drawing information as the displayed drawing information is displayed on the cholesteric LCD 16, the display can be re-displayed after the temperature change is stabilized, and the occurrence of display unevenness can be prevented.

  Further, drawing information is stored in the RAM 113, drawing information displayed in the driving state is held in the non-driving state by the cholesteric LCD 16, the temperature of the cholesteric LCD 16 is detected by the temperature sensor 14, and the temperature sensor 14 is detected by the CPU 111. The amount of change in temperature is calculated on the basis of the temperature detected by the above, and it is determined whether or not the calculated amount of change in temperature exceeds a predetermined amount of change.

  Then, the CPU 111 reads the drawing information stored in the RAM 113, displays the read drawing information with the cholesteric LCD 16 in the driving state, and holds the drawing information with the cholesteric LCD 16 in the non-driving state. After that, when it is determined that the change amount of the temperature calculated by the CPU 111 exceeds a predetermined change amount, the same drawing information as the drawing information displayed on the cholesteric LCD 16 is read from the RAM 113 and the read drawing Information is displayed on the cholesteric LCD 16.

  Therefore, it is possible to prevent display unevenness of a display having a memory property, for example, cholesteric LCD 16. The drawing information is redisplayed only when the temperature change amount exceeds the specified change amount and there is a high possibility that display unevenness has occurred, so unnecessary rewriting can be eliminated and the battery life can be maximized. Can be extended. Therefore, it is not necessary for the user of the display device to check for display unevenness, and the number of battery replacements can be reduced, so that the burden on the user can be reduced.

  FIG. 5 is a block diagram showing a configuration of an electronic shelf label system 20 which is another embodiment of the present invention. The display method according to the present invention is executed by the electronic shelf label system 20. An electronic shelf label system 20 that is a display system includes an electronic shelf label server 21, a base station 22, a transceiver 23, and the electronic shelf label 1. The electronic shelf label 1 is composed of constituent elements corresponding to the constituent elements of the electronic shelf label 1 shown in FIG. 1, and detailed description of the same constituent elements is omitted to avoid duplication.

  The electronic shelf label server 21 that is a management device is a server that stores and manages drawing information to be displayed on each electronic shelf label 1, and is configured by a computer, for example. The base station 22 sends the drawing information instructed from the electronic shelf label server 21 to the transceiver 23 having jurisdiction over the electronic shelf label 1 to which the drawing information is to be transmitted. The transceiver 23 transmits drawing information instructed from the base station 22 to the plurality of electronic shelf labels 1 arranged in the area to be controlled.

  When receiving the drawing information from the transceiver 23, the CPU 111 of the electronic shelf label 1 displays the received drawing information on the cholesteric LCD 16 without storing the received drawing information in the RAM 113. The CPU 111 monitors the temperature notified from the temperature sensor 14 via the ADC 115, and if the amount of change in temperature exceeds a predetermined amount of change, there is a possibility that display unevenness has occurred. The drawing information is acquired from the above, and the acquired drawing information is displayed again on the cholesteric LCD 16.

  In the above-described embodiment, the electronic shelf label is described as an example of the display device. However, the display device is not limited to the electronic shelf label. For example, the display device is installed at a ticket gate of a station or a bus stop. Display device with memory that displays information such as tables and advertisements, display device with memory property that is assigned to each item to identify items moving through the manufacturing process in the factory, and stored in a warehouse in the factory The present invention can be applied to a display device having a memory property installed in an environment where the temperature changes, such as a display device having a memory property provided for each book to be stored in a library or the like.

  As described above, the electronic shelf label server 21 that stores the drawing information and the cholesteric LCD 16 that can hold the display information displayed in the driving state in the non-driving state. When the drawing information is displayed on the cholesteric LCD 16 in the electronic shelf label system 20 including the electronic shelf label 1 that displays the drawn information on the cholesteric LCD 16, the temperature of the cholesteric LCD 16 is detected by the temperature sensor 14 in the electronic shelf label 1. Then, the CPU 111 calculates the amount of change in temperature based on the temperature detected by the temperature sensor 14, and determines whether or not the calculated amount of change in temperature exceeds a predetermined amount of change.

  Then, the CPU 111 reads the drawing information stored in the RAM 113, displays the read drawing information with the cholesteric LCD 16 in the driving state, and holds the drawing information with the cholesteric LCD 16 in the non-driving state. After that, when it is determined that the amount of change in temperature calculated by the CPU 111 exceeds a predetermined amount of change, the same drawing information as the drawing information displayed on the cholesteric LCD 16 is acquired from the electronic shelf label server 21 and acquired. The drawn information is displayed on the cholesteric LCD 16.

  Therefore, it is possible to prevent display unevenness of a display having a memory property, for example, cholesteric LCD 16. The drawing information is redisplayed only when the temperature change amount exceeds the specified change amount and there is a high possibility that display unevenness has occurred, so unnecessary rewriting can be eliminated and the battery life can be maximized. Can be extended. Therefore, it is not necessary for the user of the display device to check for display unevenness, and the number of battery replacements can be reduced, so that the burden on the user can be reduced. Furthermore, since it is not necessary to mount a memory for storing drawing information on the electronic shelf label 1, the electronic shelf label 1 can be miniaturized and the product cost can be reduced.

It is a block diagram which shows the structure of the electronic shelf label 1 which is one Embodiment of this invention. It is a figure which shows an example of the drawing information displayed on cholesteric LCD16. It is a figure which shows the example of the variation | change_quantity of the temperature used as the conditions for redisplay. It is a flowchart which shows the display process which CPU111 performs. It is a block diagram which shows the structure of the electronic shelf label system 20 which is the other form of implementation of this invention.

Explanation of symbols

1 Electronic shelf label 11 Control IC
DESCRIPTION OF SYMBOLS 12 Battery 13 LCD power supply circuit 14 Temperature sensor 15 Antenna 16 Cholesteric liquid crystal 17 COMMON driver 18 SEGMENT driver 20 Electronic shelf label system 21 Electronic shelf label server 22 Base station 23 Transceiver 111 CPU
112 ROM
113 RAM
114 RTC
115 ADC
116 RF
117 I / O

Claims (8)

A display method for displaying display information on a display unit of a display device including a display unit capable of holding display information displayed in a driving state in a non-driving state,
A display step of displaying display information with the display unit in a driven state, and then holding the display information with the display unit in a non-driven state;
A temperature detecting step for detecting the temperature of the display unit;
A calculation step for calculating a change amount of the temperature based on the temperature detected in the temperature detection step;
A determination step of determining whether or not the temperature change amount calculated in the calculation step exceeds a predetermined change amount;
In the determination step, when it is determined that the temperature change amount calculated in the calculation step exceeds a predetermined change amount, the same display information as the display information displayed on the display unit in the display step is displayed on the display unit. A display method comprising: a redisplay step of displaying.   The display method according to claim 1, wherein the change amount of the temperature is a temperature gradient.   The display method according to claim 1, wherein the change amount of the temperature is a temperature difference.   The display method according to claim 1, wherein the temperature change amount is an integrated amount of temperature change. The display device further includes a storage unit that stores display information to be displayed on the display unit,
The display method according to claim 1, wherein in the re-displaying step, display information stored in the storage unit is read and the read display information is displayed on the display unit. After the determination step determines that the temperature change amount calculated in the calculation step exceeds a predetermined change amount, whether the temperature change amount calculated in the calculation step is equal to or less than the predetermined change amount. And further including a second determination step of determining whether or not
In the re-displaying step, it is calculated in the calculating step in the second determining step after it is determined in the determining step that the amount of change in temperature calculated in the calculating step exceeds a predetermined amount of change. The display information that is the same as the displayed display information is displayed on the display unit when it is determined that the temperature change amount is equal to or less than the predetermined change amount. The display method according to one. Storage means for storing display information;
Display means capable of holding display information displayed in a driving state in a non-driving state;
Temperature detecting means for detecting the temperature of the display means;
Calculation means for calculating a change in temperature based on the temperature detected by the temperature detection means;
Determining means for determining whether or not the amount of change in temperature calculated by the calculating means exceeds a predetermined amount of change;
The display information stored in the storage means is read out, the read display information is displayed with the display means in a driving state, and the display information is held in a non-driving state, and then the determination is made. When it is determined by the means that the amount of change in temperature calculated by the calculating means exceeds a predetermined amount of change, the same display information as the display information displayed on the display means is read from the storage means and read out. And a control means for causing the display means to display display information. A management device for storing display information; and display means capable of holding display information displayed in a driving state in a non-driving state, acquiring display information from the management device, and displaying the acquired display information on the display means A display system including:
The display device
Temperature detecting means for detecting the temperature of the display means;
Calculation means for calculating a change in temperature based on the temperature detected by the temperature detection means;
Determining means for determining whether or not the amount of change in temperature calculated by the calculating means exceeds a predetermined amount of change;
The display information stored in the storage means is read out, the read display information is displayed with the display means in a driving state, and the display information is held in a non-driving state, and then the determination is made. When it is determined by the means that the change amount of the temperature calculated by the calculation means exceeds a predetermined change amount, the same display information as the display information displayed on the display means is acquired from the management device and acquired. And a control means for causing the display means to display the displayed information.

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