JP2007279481A - Information display system, display body controller, and display body control program - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an information display device capable of providing display of high quality even if a storage type display body which has significant characteristic variation with temperature has abrupt temperature variation. <P>SOLUTION: The information display device once detecting use by a user (Yes in step S102) measures the temperature of the display body 1 at a predetermined sampling rate (step S103). Based upon temperature information thereof, it is decided whether abrupt temperature variation is caused (step S106) and when abrupt temperature variation is caused (Yes), temperature predictive operation is carried out (step S107). A driving parameter is determined based upon a temperature predicted value which is thus computed. Consequently, when the abrupt temperature variation is caused, high-precision temperature compensation can be performed. Further, the temperature measurement and temperature prediction are carried out in two stages to suppress power consumption. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an information display system, a display body control device, and a display body control program, and more particularly to an information display system, a display body control device, and a display body control program provided with a memory-type display body.

In recent years, an information display device having a memory-type display body has been put into practical use. Since a memory-type display body consumes power only at the time of rewriting, it consumes much less power than a normal display body. For this reason, since a battery capacity can be reduced and a device can be reduced in size, it has been attracting attention as a display suitable for an application such as an electronic book.
By the way, the liquid crystal used for the display body generally has a property that the reflectivity (V-R characteristic) with respect to the driving waveform varies with temperature. The cause is mainly that the viscosity of the display material changes with temperature. For this reason, conventionally, in display body driving, temperature compensation for measuring the temperature of the display body and its surroundings and correcting the drive waveform accordingly is performed (for example, Patent Document 1).
JP-A-9-5713

  However, the display material of the memory-type display has a problem that the change in characteristics due to temperature is particularly remarkable. For example, in the case of a cholesteric liquid crystal DDS (Dynamic Drive scheme) driving method, in order to perform halftone display, the optimum driving conditions differ in steps of 1 ° C. or less, so a measurement accuracy of several millimeters C level is required. The

  Furthermore, in the practical stage, the environmental temperature may change rapidly, for example, when the information display device is taken out from the room at 20 ° C. to the outdoor at 0 ° C., not only when the environmental temperature is stable. In such a case, the response temperature (the time difference from the measurement of the temperature until the display is driven, and the time difference between the measurement of the temperature and the rewrite time in the screen) causes the measured temperature and the display at the time of driving. There is a problem that an error occurs between the temperature and the temperature. Therefore, appropriate gradation display may not be possible on the entire screen or from the middle of the screen.

  The present invention has been made in view of the above-mentioned problems, and is an information display system capable of high-quality display even when a sudden temperature change occurs in a memory-type display body in which a characteristic change due to temperature is remarkable, It is an object to provide a display body control device and a display body control program.

  In order to solve the above problems, an information display system according to an aspect of the present invention is an information display system that displays information on a screen of a memory-type display body, and a temperature at which the temperature around the display body or the display body is measured. The measurement means and the temperature around the display body or the display body at a plurality of time points are acquired from the temperature measurement means as time series information of the temperature around the display body or the display body, and based on the time series information, the time Temperature estimation means for estimating a temperature change of the display body after acquisition of sequence information; display body drive control means for determining drive content of the display body based on the temperature change estimated by the temperature estimation means; and the display Display body drive means for driving the display body with the drive content determined by the body drive control means and rewriting information to be displayed on the screen.

This corrects the error between the measured temperature generated by the response lag and the temperature of the display body during driving, and even when a sudden temperature change occurs, the temperature of the display body at the start of driving is highly accurate. Can be predicted. As a result, it is possible to drive using the optimum temperature compensation parameter, so that it is possible to display a high-quality image with good reproducibility of the intermediate gradation.

  In addition, the “information display system” is used not only when the information display device is configured integrally with the above-described configuration requirements, but also when the above-described configuration requirements are separately mounted on a plurality of devices. It is meant to include the case where the present embodiment is realized in cooperation by connecting apparatuses. Examples of such an information display stem include, for example, a client device including the display body, the temperature measuring unit, and the display body driving unit, and a host device (personal computer) including the temperature estimating unit. The information display system comprised from these is mentioned. In this case, the above function is achieved by transmitting and receiving temperature information to each other.

The information display system according to an aspect of the present invention is characterized in that the temperature estimation unit estimates the temperature of the display body at an arbitrary time after the acquisition of the time series information.
In the information display system according to an aspect of the present invention, the temperature estimation unit estimates a temperature change of the display body after obtaining the time series information based on a temperature change rate calculated from the time series information. It is characterized by.

  As an example of temperature estimation using such a temperature change rate, the temperature change rate in the vicinity of the temperature information acquisition time is calculated, it is determined whether it is negative or positive, and at the drive start time There is a method for determining whether the temperature falls or rises below the currently acquired temperature. If the temperature change rate is negative and the temperature is decreasing, a temperature slightly lower than the currently acquired temperature is set, and if it is increasing, it is slightly higher than the currently acquired temperature. Set a higher temperature. Thus, simple temperature correction is possible.

In the information display system according to one aspect of the present invention, the temperature estimation unit is configured to display the display by an interpolation method based on time series information of the display body or the temperature around the display body measured at equal intervals by the temperature measurement unit. An approximate function of body temperature and time is calculated, and a temperature change of the display body after obtaining the time series information is estimated based on the approximate function.
As a result, although the amount of calculation is slightly increased as compared with the above-described aspect, highly accurate temperature estimation is possible.

In the information display system according to an aspect of the present invention, the temperature estimation unit estimates a temperature change of the display body from the time series information acquisition until the display body driving unit starts driving the display body. It is characterized by that.
Thereby, it is possible to prevent the occurrence of an error due to a time difference from the temperature measurement to the start of driving, and display a high-quality image based on appropriate temperature compensation.

In the information display system according to an aspect of the present invention, the temperature estimation unit divides the screen of the display body into a plurality of regions having different information rewrite start points, and the display body after the time series information is acquired. A temperature change of the display body until each rewrite start time of each area by the driving means is estimated, and the display body drive control means is based on the temperature change until the rewrite start time of each area estimated by the temperature estimation means. The display body driving means rewrites information in each area by driving the display body with each drive content determined by the display body drive control means. It is characterized by.
As a result, optimal drive parameters can be set in response to temperature changes that occur during the rewrite time of the display body, avoiding situations such as the deterioration of the reproducibility of intermediate tones from the middle of the screen, and high quality. Images can be displayed.

In the information display system according to an aspect of the present invention, the temperature estimation unit stores a plurality of types of temperature change patterns of the display body in a predetermined period in a temperature change pattern table in advance, and at least a part of the predetermined period. The temperature change pattern in which the temperature change matches the temperature change of the display body appearing in the time series information, or the temperature change of the display body after obtaining the time series information estimated based on the time series information Is extracted from the temperature change pattern table, and the temperature change until each rewrite start time of each region is calculated according to the extracted temperature change pattern.
In this way, the display object at the time of starting rewriting of each area can be performed only by performing temperature prediction using an interpolation method with a large amount of calculation at least once, and then selecting a temperature change pattern with a relatively small amount of calculation. Since the temperature of this can be estimated, the calculation process can be shortened.

  In the information display system according to one aspect of the present invention, as the temperature measuring means, a first temperature measuring means for measuring the temperature of the display body, and a second temperature measuring means for measuring the outside air temperature around the display body. And the temperature estimating means acquires temperature information from the first and second temperature measuring means respectively, and for the outside air temperature information acquired from the second temperature measuring means, obtains the outside air temperature information. It approximates to the temperature information of the said display body in the time later than a time, It uses for the estimation of the temperature change after the said acquisition.

Since the temperature of the display body changes according to the outside air temperature, the outside air temperature indicates the future temperature of the display body. Therefore, by using this as one of the time-series information of the temperature of the display body, more information can be obtained, the accuracy of temperature prediction can be improved, and prediction calculation processing can be reduced.
An information display system according to an aspect of the present invention includes a plurality of the temperature measurement units, and the plurality of temperature measurement units respectively measure a display body part corresponding to the plurality of regions or a temperature around the display body part. And the said temperature estimation means estimates the said temperature change of each corresponding display body part based on each time series information acquired from each said temperature measurement means, It is characterized by the above-mentioned.

By obtaining more accurate temperature information of each region, for example, even when a spatial temperature difference occurs between the regions, temperature prediction can be performed accurately, and highly accurate temperature compensation is possible.
An information display system according to an aspect of the present invention includes use detection means for detecting use of a user, and operates the temperature measurement means only when use is detected by the user by the use detection means. And
Since the consumption of energy becomes unnecessarily large when the temperature is constantly obtained, the power consumption can be reduced by using this mode.

An information display system according to an aspect of the present invention includes a temperature change detection unit that detects a sudden temperature change based on information on a temperature of the display body or a display body measured by the temperature measurement unit, and the temperature The estimating means performs the estimation only when a sudden temperature change is detected by the temperature change detecting means.
If comprised in this way, since a prediction process with much calculation amount can be performed only when needed, power consumption can be suppressed. In combination with the aspect using the above-described use detecting means, the energy saving effect can be further enhanced by taking a two-stage power saving measure.

  A display body control device according to an aspect of the present invention is a display body control device that displays information on a screen of a memory-type display body, wherein the display body or the temperature around the display body at a plurality of points in time After acquiring the time-series information based on the time-series information about the temperature of the display body or the temperature around the display body acquired by the temperature information acquisition section and the temperature information acquisition means that acquires the time-series information about the temperature around the display body Temperature estimation means for estimating the temperature change of the display body and display body drive control means for determining the drive content of the display body based on the temperature change estimated by the temperature estimation means. .

The display body control program according to one aspect of the present invention is the display body control program for displaying information on a screen of a memory-type display body, wherein the display body or the temperature around the display body at a plurality of points in time is displayed. Based on the temperature information acquisition step acquired as time series information of the temperature around the body or the display body, and the time series information of the temperature around the display body or display body acquired in the temperature information acquisition step, the time series information A temperature estimation step for estimating a temperature change of the display body after acquisition; and a drive content determination step for determining the drive content of the display body based on the temperature change estimated in the temperature estimation step. To do.

Next, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a block diagram showing an internal configuration of the information display apparatus according to the present embodiment, and FIG. 2 is a flowchart of the information display apparatus according to the present embodiment.
1 includes a prediction system activation controller 52, a display body (display) 1, temperature measuring means (temperature sensor 31 and AD converter 32), CPU 41, display body drive control circuit 44, display body. And a drive circuit 2.

  The prediction system activation controller 52 outputs a switching command to the activation mode to the CPU 41 in response to the detection signal from the usage detection sensor 51 that detects the user's usage, and executes the temperature prediction program. As the use detection sensor 51, for example, an acceleration sensor or a thermostat can be used, and these detect the carrying operation of the information display device of the user. This use detection sensor 51 corresponds to the use detection means of the present invention.

  In this embodiment, the display body 1 uses a cholesteric liquid crystal display body. Since cholesteric liquid crystals have different light reflectivities depending on the alignment state, a target image can be displayed by controlling the alignment state of the cholesteric liquid crystal in each pixel region. The alignment state can be controlled by applying a voltage. However, since the alignment state of liquid crystal molecules in the display state is stable, the alignment state is maintained even when no voltage is applied. Accordingly, the display content once rewritten can be maintained without consuming power.

  The temperature measuring means includes a temperature sensor 31 and an AD converter (A / D in the figure) 32. As the temperature sensor 31, a thermistor whose resistance decreases as the temperature rises or a P semiconductor with temperature characteristics can be applied. The temperature sensor 31 is attached to the display body 1 and outputs a value corresponding to the temperature of the display body 1. The AD converter 32 A / D converts the output value from the temperature sensor 31 and outputs the digitized temperature information to the past temperature storage memory 33 via the CPU 41.

  A CPU (Central Processing Unit) 41 executes a temperature prediction program and a display body drive program in parallel, and controls the temperature measurement means and the display body drive control circuit 44 according to the both programs. In the temperature prediction program, the temperature information of the display body 1 is acquired in real time from the temperature measuring means, and the process of estimating the temperature of the display body 1 at the start of driving of the display body 1 is executed based on the time series information of the temperature. To do. This estimation operation will be described in detail later. The above temperature estimation operation by the CPU 41 corresponds to the processing of the temperature estimation means of the present invention. The display body drive program is executed when an image rewrite button (not shown) is pressed by the user, and outputs an image rewrite command to the display body drive control circuit 44.

When the image rewriting command is output from the CPU 41, the display body drive control circuit 44 acquires the temperature value of the display body 1 at the time of driving from the temperature prediction program, and the optimum drive parameter according to the temperature of the display body 1 Is output to the display drive circuit 2. Here, the drive parameter includes a voltage value of a drive voltage waveform applied to the liquid crystal, an application time, and the like. The information display device holds a correspondence table between the liquid crystal temperature and the drive parameter in order to determine the drive parameter. The display body drive control circuit 44 corresponds to the display body drive control means of the present invention.

  When the drive parameter is output from the display body drive control circuit 44, the display body drive circuit 2 generates a drive voltage waveform specified by the drive parameter and applies it to the display body 1. In this embodiment, for example, it is assumed that the display body 1 is a cholesteric liquid crystal sandwiched between two pieces of glass with matrix pixel electrodes (passive matrix method). Further, the driving method of the display body 1 is the DDS method, and for example, the driving voltage waveform proposed in US Pat. No. 5,748,277 is applied to the display body 1. The drive parameter specifies the voltage value and pulse width of the drive voltage waveform in the DDS Selection period according to the temperature of the display body 1. The display body driving circuit 2 corresponds to the display body driving means of the present invention.

Next, the operation of the information display apparatus will be described with reference to the flowchart of FIG.
First, in step S101, the information display device is in a standby mode. In this state, the temperature prediction program and the display body driving program are not executed, and only the use detection sensor 51 is operating, and thus the power consumption is low. And when a user carries an information display apparatus etc. and the use detection sensor 51 detects a user's use, the prediction system starting controller 52 switches to starting mode. Thereby, the temperature prediction program is executed, and the state shifts to the start mode 1 (steps S102 to S103). On the other hand, when the use by the user is not detected (step S102, No), the standby mode is maintained.

  In startup mode 1 in step S103, sampling of temperature information by the temperature measuring means is started. Sampling is performed, for example, at a constant sample rate, and the temperature information is stored in the past temperature storage memory 33 (step S104). The past temperature storage memory 33 stores n pieces of data, and the past past n pieces of data are discarded or rewritten. Next, the CPU 41 statistically predicts the temperature change of the past temperature data stored in the past temperature storage memory 33 and determines the threshold value in real time (step S105). As a method, for example, an average value m and a standard deviation value s of past n data are obtained. Next, m + s and m−s are set as threshold values, and when the detected temperature is higher than m + s or lower than m−s (Yes), it is determined that a rapid temperature change has occurred. In this case, the mode is shifted from the start mode 1 to the start mode 2 (step S107). On the other hand, if it is equal to or less than the threshold value (No), the process returns to step S103 and the temperature is sampled again.

Next, in start-up mode 2 in step S107, calculation for predicting the temperature or temperature fluctuation of the display body 1 when the display body 1 is actually driven is performed. As the prediction method, the Newton's Backward Difference back-difference method in the digital domain can be used. This method can obtain analytical formulas based on sample data in a manner similar to differentiation in a continuous region, and can be applied to extrapolation.
For example, the first backward difference ▽ θ can be obtained from the n pieces of temperature data by the following equation (1).

Here, the subscript of θ in Equation (1) is a natural number (or zero) indicating the sampling order, and the smaller the value, the more the data acquired in the past.
Further, the second backward difference is obtained as in the following formula (2).

  By interpreting this more generally, the k-th order backward difference is obtained as the following equation (3).

  Finally, when a Newton's Backward Difference formula (4) is used, a polynomial can be obtained from n pieces of data.

This polynomial, when sample data from 0 to n, the time-temperature theta _n time index n, (the derivative of the digital domain) currently obtained and that data theta _n-1 determined from the through? ₀ difference ∇ ₀ It approximates with the value of ^{1 to} ∇ ₀ ⁿ and the sample time index n. That is, if future indices n + a, n + b, n + c,... Are substituted for n in this polynomial, future temperatures θ _{n + a} , θ _{n + b} , θ _{n + c} can be approximated by extrapolation. Parameters n + a, n + b, n + c
,... Indicates that a numerical value in the future is acquired with respect to the sample n currently acquired on the time axis. In the present embodiment, the temperature of the display body 1 at the driving start time of the display body 1 after the temperature information acquisition time is estimated. This method is characterized by being able to cope with non-linear changes.

The temperature at the start of driving of the display body 1 estimated as described above is output and stored in the past temperature storage memory 33 (step S108).
The prediction system activation controller 52 monitors the user's operation (step S109), and repeats temperature sampling as long as the user's operation continues (steps S103 to S108), and detects that the user operation has stopped. If it does (No), it will transfer to standby mode (step S101).

  In the information display device, when the image rewriting button is pressed in the state of the activation mode 1 or 2, the display body driving program is executed in parallel with the processing by the temperature prediction program. When the display body driving program is executed, the temperature information of the display body 1 at the driving start time constantly updated by the temperature prediction program as described above is delivered to the display body driving control circuit 44. The display body drive control circuit 44 determines an optimum drive parameter based on this temperature value.

Next, temperature prediction will be described with specific numerical examples.
When the user has an information display device (electronic paper or the like), the prediction system activation controller 52 detects and changes from the standby mode to the activation mode. Now start measuring the temperature. Specifically, 100 pieces of temperature data are measured per second from a sample rate of 100 Hz.
Using that value, for example, the average value of temperature is 20 ° C. and the standard deviation is 2 ° C., which is obtained by calculation.

Then, in this environment (if there is no sudden temperature change), an image is displayed by an optimum driving method as in the past based on the measured temperature.
However, when the user moves to a place where the temperature is 0 ° C. with the information display device, the temperature of the information display device gradually decreases, and when the temperature falls below a standard deviation of 2 ° C. (18 ° C. or less), the information display device Recognizes a sudden change in temperature, and starts the above temperature prediction calculation.

Here, when the user presses the rewrite button on the screen, the image on the information display device (electronic paper) is rewritten, but until the display body actually starts to be driven after the user performs an operation for rewriting. If the time is 100 msec (a time equivalent to 10 samples from the sample rate), the temperature when the user presses the rewrite button on the screen is set to 15 ° C. (θ ₀ ), for example, and after 100 msec at the sampling number 10 (user The temperature θ _n after a period of time during which the display body actually starts to be driven after the operation for rewriting can be obtained. If the result θ _n = 13 ° C., the image is displayed with the temperature compensation parameter of 13 ° C. instead of the temperature compensation parameter of 15 ° C.

  As described above, even when the temperature suddenly changes, the temperature change from when the temperature of the display body 1 is measured to when the display body 1 starts to drive can be accurately estimated, so that optimum temperature compensation can be performed. , Can display high-quality images. In this embodiment, temperature prediction is performed only when there is a sudden temperature change, and when there is almost no temperature change, a prediction process that consumes power is required by using the measured value as it is. In this case, unnecessary power consumption can be suppressed. The application of the present invention is not limited to this, and when the characteristic change due to temperature is extremely large, the startup mode may be set to one stage, and temperature prediction may always be performed in the startup mode. Further, it is possible to cope with this by lowering the threshold value for determining whether or not the rapid temperature change has occurred.

(Second Embodiment)
Next, a second embodiment will be described.
The information display device according to the second embodiment has substantially the same configuration as the information display device according to the first embodiment and operates in the same manner. However, the information display device performs temperature compensation in consideration of the rewrite time difference in the screen of the display body 1. Is different in that. Hereinafter, different points will be described.
FIG. 3 is a plan view showing the display body 1 of the information display device according to the second embodiment. As shown in FIG. 3, the information display device rewrites an image by performing line-sequential scanning on the screen from the upper side to the lower side of the page. At this time, for example, 300 msec is required to rewrite from the top to the bottom of the screen. Therefore, in the second embodiment, the length of the screen in the rewriting direction is divided into three equal parts, three areas A, B, and C continuous in the direction are set and rewritten as follows.

  As described above, when the information display device is in the start mode 1 or 2, the temperature sensor 31 measures the temperature of the display body 1 at a sample rate of 100 Hz. When the area A is rewritten, the temperature prediction is performed with a predetermined number of samples (for example, 10), and the display body 1 is driven with the temperature compensation parameter determined based on the temperature prediction value. Since rewriting of area A requires 100 msec, a time difference of 100 msec occurs in rewriting area A and area B. Therefore, when rewriting the region B, the temperature information is sampled by combining the 10 pieces of temperature information sampled during this time and the temperature information acquired before that time, and the temperature compensation parameter is determined by performing the temperature prediction with 20 samples. The display body 1 is driven. Similarly, when rewriting region C, temperature information acquired during the rewrite time difference with region B is added, temperature prediction is performed with 30 samples, temperature compensation parameters are determined, and display 1 is driven. .

As described above, more accurate temperature compensation is possible by taking into account the difference in rewriting time and obtaining the latest temperature predicted value based on the latest temperature information acquired during rewriting of other areas. Become. The number of regions is not limited to this, and may be increased or decreased.

(Third embodiment)
Next, a third embodiment will be described.
The information display device according to the third embodiment has substantially the same configuration and the same operation as the information display device according to the second embodiment, but three temperature sensors are displayed on the display body corresponding to the regions A, B, and C. 1 is different in that it is attached to the back surface portion of 1 and the temperature of each region is measured. Hereinafter, this point will be described.

  As described above, when the information display device is in the state of the activation mode 1 or 2, the three temperature sensors respectively measure the temperatures of the areas A to C of the display body 1 at the sample rate of 100 Hz. When rewriting the image of the area A, temperature prediction is performed with a predetermined sampling number (for example, 10), and the display body 1 is driven using the temperature compensation parameter determined based on the temperature prediction value. Next, the region B is rewritten, and the temperature compensation parameter at this time is determined by using the predicted temperature value calculated based on the ten pieces of temperature information acquired during the rewrite time difference from the region A. Similarly, using the temperature information acquired during the rewriting time difference with the region B, temperature prediction is performed with a sampling number of 10, the temperature compensation parameter is determined, and the region C is rewritten. That is, the temperature prediction calculations for the regions A, B, and C are started independently with a time difference of 100 msec, and the regions A, B, and C each have temperature compensation parameters determined based on the temperature prediction values of 10 samplings. Can be rewritten using

  As described above, by setting each region of the temperature sensor, it is possible to obtain temperature information with higher accuracy for each region, so that optimum temperature compensation can be performed based on highly accurate temperature prediction, High quality images can be displayed.

(Fourth embodiment)
Next, a fourth embodiment will be described.
The information display device according to the fourth embodiment operates in substantially the same configuration as the information display device according to the second embodiment, but operates in the same manner. Is different in that This point will be described below.

  FIG. 4 shows an example of a two-dimensional lookup table. The look-up table in FIG. 4 defines a plurality of types of time transitions (corresponding to the temperature change pattern of the present invention) of temperature differences (temperature change amounts), and a ROM (not shown) to which the CPU 41 can refer experimental values and the like. ) In advance. The graph of FIG. 4 is a model in which the liquid crystal display is a Lumped Model of thermal transition (a model in which the thermal transition of the solid and the fluid is indefinite is taken into account, and the temperature gradient in the solid is not significant: Bio number <0.1. ) Was obtained by simulating the case considered as). The temperature difference on the vertical axis is the difference between the final temperature of the display body and the temperature at the start of sampling. FIG. 4 shows each temperature change pattern when the temperature difference is 27K, 20K, 12K, 7K, 2K. It is shown. In the present embodiment, the final temperature is obtained by, for example, calculating a predicted temperature value when a sufficient time has elapsed from the sampling start time based on the sampled temperature information. The operation flow will be described below.

When the information display device is in the start mode 1 or 2, the temperature sensor 31 (one in the present embodiment) measures the temperature of the display body 1 at a sample rate of 100 Hz. And when a sudden temperature change is detected, temperature prediction is performed based on the temperature information of the predetermined sample number (for example, 10 pieces) acquired so far, and the predicted value of final temperature is obtained. Then, a difference between the final temperature and the temperature of the display body measured at the sample start time (first data among 10) is obtained, and the temperature change at which the temperature difference at the time of 0 msec matches the calculated difference. Extract the pattern from the lookup table. Since the time until the start of rewriting of each area A to C from the time of calculation is fixed, the temperature difference corresponding to the time until the start of rewriting of each area is specified according to the extracted temperature change pattern, and the value of the final temperature By adding to, it is possible to obtain the predicted temperature value of the display body 1 at the time of rewriting each area. When the temperature change pattern of the corresponding temperature difference is not in the above lookup table, or when predicting from the approximate temperature difference, the prediction can be made by using the interpolation method. FIG. 4 shows a lookup table when the temperature at the start of sampling is higher than the final temperature. In the opposite case, a separately prepared lookup table is used.

  With the above configuration, it is possible to reduce the calculation processing time by performing the temperature prediction by the interpolation method with a large amount of calculation only once and the rewriting start time of the three regions can be performed by selecting the pattern. it can. As a result, the time of the response lag is shortened, so that highly accurate temperature estimation is possible and highly accurate temperature compensation is possible. In addition, power consumption during arithmetic processing can be suppressed.

  The fourth embodiment is not limited to the above. For example, as a final temperature, instead of using the temperature predicted value by the interpolation method as described above, for example, a measured value of the outside temperature can be used. In this case, in addition to the temperature sensor 31 that measures the temperature of the display body 1, an outside temperature sensor that measures the outside temperature is provided. Then, the outside air temperature is measured at the time of temperature sampling of the display body 1 (step S103 in FIG. 2) or at the time of temperature prediction calculation in the startup mode 2 (step S107 in FIG. 2). Since the temperature of the display body 1 follows the change in the outside air temperature, the outside air temperature can be approximated to the future temperature of the display body 1. Therefore, for example, the outside temperature is approximated as the final temperature, and the difference between the outside temperature and the temperature of the display body at the start of sampling is obtained. Thereafter, the temperature is the same as described above, and the predicted temperature value of the display 1 at the time of starting rewriting of each of the areas A to C can be calculated using the lookup table of FIG. Thereby, calculation processing can be shortened. In this case, the temperature sensor 31 corresponds to the first temperature measurement means of the present invention, and the outside air temperature sensor corresponds to the second temperature measurement means of the present invention.

In addition, the temperature change pattern is not limited to selecting the temperature change pattern by comparing the temperature difference between the final temperature and the start temperature. The temperature change pattern may be selected according to the temperature value and the temperature difference.
In the first to fourth embodiments, the memory-type display body using the cholesteric liquid crystal has been described. However, the present invention is not limited to other memory-type display bodies (for example, an electrophoretic method) whose characteristics change greatly with temperature. ).

It is a block diagram which shows the internal structure of the information display apparatus of 1st Embodiment. It is a flowchart of the information display apparatus of 1st Embodiment. It is a figure explaining the temperature prediction method of 2nd-4th embodiment. It is a figure which shows the example of a look-up table (4th Embodiment).

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Display body, 2 Display body drive circuit, 31 Temperature sensor, 32 AD converter,
33 Past temperature storage memory, 41 CPU, 44 Display body drive control circuit, 51
Use detection sensor, 52 Predictive system start controller

Claims (13)

In an information display system for displaying information on a screen of a memory-type display body,
Temperature measuring means for measuring the temperature of the display body or the surroundings of the display body;
The display body or the temperature around the display body at a plurality of time points is acquired from the temperature measurement means as time series information of the temperature around the display body or the display body, and the time series information is acquired based on the time series information. A temperature estimating means for estimating a temperature change of the display body later;
Display body drive control means for determining the drive content of the display body based on the temperature change estimated by the temperature estimation means;
Display body drive means for rewriting information to be displayed on the screen by driving the display body with the drive content determined by the display body drive control means;
An information display system comprising:   The information display system according to claim 1, wherein the temperature estimation unit estimates a temperature of the display body at an arbitrary time after the acquisition of the time series information.   The temperature estimation unit estimates a temperature change of the display body after obtaining the time series information based on a temperature change rate calculated from the time series information. Information display system.   The temperature estimation means calculates an approximate function of the temperature and time of the display body by interpolation based on the time series information of the display body or the temperature around the display body measured at equal intervals by the temperature measurement means. The information display system according to claim 1, wherein a temperature change of the display body after the acquisition of the time series information is estimated based on the approximate function.   The temperature estimation means estimates the temperature change of the display body from the time series information acquisition until the display body drive start time of the display body by the display body drive means. The information display system described in Crab. The temperature estimation unit divides the display body screen into a plurality of regions having different information rewrite start time points, and from the time series information acquisition to each rewrite start time point of the respective regions by the display body drive unit. Estimating the temperature change of the display body of
The display body drive control means determines each drive content when rewriting each area, based on the temperature change until the rewrite start time of each area estimated by the temperature estimation means,
The said display body drive means drives the said display body by each drive content determined by the said display body drive control means, and rewrites the information of each area | region, The one of Claims 1-5 characterized by the above-mentioned. Information display system. The temperature estimating means includes
A plurality of types of temperature change patterns of the display body in a predetermined period are stored in a temperature change pattern table in advance,
The temperature change of the display body in which the temperature change in at least a part of the predetermined period appears in the time series information, or the temperature change of the display body after obtaining the time series information estimated based on the time series information The matching temperature change pattern is extracted from the temperature change pattern table, and the temperature change until each rewrite start time of each region is calculated according to the extracted temperature change pattern. The information display system described. As the temperature measuring means,
First temperature measuring means for measuring the temperature of the display body;
Second temperature measuring means for measuring the outside air temperature around the display body,
The temperature estimating means acquires temperature information from the first and second temperature measuring means respectively, and the outside air temperature information acquired from the second temperature measuring means is later than the acquisition time of the outside air temperature information. The information display system according to claim 1, wherein the information display system is used to estimate temperature change after the acquisition by approximating temperature information of the display body at a time point. A plurality of the temperature measuring means;
The plurality of temperature measuring means measure the temperature around the display body portion or the display body portion corresponding to the plurality of regions,
The information display system according to claim 6, wherein the temperature estimation unit estimates the temperature change of each corresponding display body portion based on each time-series information acquired from each temperature measurement unit. A use detecting means for detecting a user's use;
The information display system according to claim 1, wherein the temperature measuring unit is operated only when use is detected by the user by the use detecting unit. Based on information on the temperature of the display body or the surroundings of the display body measured by the temperature measurement means, a temperature change detection means for detecting a sudden temperature change,
The information display system according to claim 1, wherein the temperature estimation unit performs the estimation only when a sudden temperature change is detected by the temperature change detection unit. In a display control apparatus for displaying information on a screen of a memory display,
Temperature information acquisition means for acquiring the display body or the temperature around the display body at a plurality of time points as time-series information of the temperature around the display body or the display body;
Based on the time series information of the display body or the temperature around the display body acquired by the temperature information acquisition means, temperature estimation means for estimating the temperature change of the display body after acquisition of the time series information;
Display body drive control means for determining the drive content of the display body based on the temperature change estimated by the temperature estimation means;
A display body control device comprising: In a display control program for displaying information on a memory display screen,
A temperature information acquisition step of acquiring the temperature of the display body or the surroundings of the display body at a plurality of time points as time-series information of the temperature of the display body or the surroundings of the display body;
Based on the time series information of the display body or the temperature around the display body acquired in the temperature information acquisition step, a temperature estimation step for estimating a temperature change of the display body after acquisition of the time series information;
A drive content determination step for determining the drive content of the display body based on the temperature change estimated in the temperature estimation step;
A display body control program comprising:

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