JP2008176008A - Display device and stand device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To suppress reduction of display quality caused by temperature unevenness of a display surface in a display device. <P>SOLUTION: A memory display body 140 constitutes a display surface of the display device 100. A sensor 160 senses temperature in the vicinity of the display surface. A heater 170 heats the whole display surface. A heater controlling part 180 controls heating of the heater 170 based on the temperature sensed by the sensor 160. To put it concretely, the heater controlling part 180 supplies power to the heater 170 when the temperature sensed by the sensor 160 is a prescribed temperature (e.g. the extent of the surface temperature of a skin of a human body) or below and supplies no power to the heater 170 when the temperature sensed by the sensor 160 is higher than the prescribed temperature. Thereby the temperature of the entire surface of the display surface is made uniform and temperature unevenness is hardly generated on the display surface even when an object (a finger of an operator etc.) having a temperature near the prescribed temperature touches the display surface. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a technique for suppressing display unevenness caused by the temperature of a display surface of a display device.

A display body having memory (hereinafter referred to as “memory display body”) is used for electronic paper or the like. A memory-type display is a display that can maintain a display state (that is, gradation) without applying a voltage. For example, there is a display using a cholesteric liquid crystal (see, for example, Patent Document 1). ). Since the memory display body only needs to apply a voltage during the period of rewriting the display, it can be said to be particularly suitable for use in a display device that has low power consumption and requires portability. In addition, since the display state is stable even when no voltage is applied, the memory-type display body has a feature that there is little flickering and the eyes are hard to be tired even if the display is continued for a long time.
JP-A-7-175041

On the other hand, the memory-type display is a display method that is generally susceptible to temperature. For example, in the case of a memory-type display using cholesteric liquid crystal, the viscosity of the liquid crystal changes depending on the temperature. Therefore, if the temperature is different, the gradation is displayed even under the same driving conditions (driving speed and driving voltage). Change occurs. Therefore, for example, when a finger touches the display surface or when light (heat rays) is locally irradiated on the display surface, the temperature of the display surface becomes non-uniform, and the display is uneven. May occur.
The present invention has been made in view of such circumstances, and an object of the present invention is to provide a technology that enables a display device to suppress a reduction in display quality caused by uneven temperature on a display surface.

In order to achieve the above-described object, a display device according to the present invention includes a display unit having a display surface, a detection unit that detects a temperature in the vicinity of the display surface, and a heating unit that heats the entire display surface. And a heating control means for controlling the heating by the heating means so that the temperature detected by the detecting means falls within a predetermined range, and a switching means for switching whether to execute the control by the heating control means.
According to such a display device, the entire display surface has a substantially uniform temperature within a predetermined range. Therefore, even when an object having a temperature close to the temperature (for example, an operator's finger) is touched, the display surface is displayed. Surface unevenness is less likely to occur.
As the display surface in the present invention, it is preferable to use a memory display such as cholesteric liquid crystal. However, the present invention is not limited to cholesteric liquid crystals, and can be applied to various display bodies whose responsiveness changes depending on temperature.

  Further, in the display device of the present invention, the detection means detects temperatures at a plurality of positions on the display surface, and the heating means includes each of the display surfaces and is located at any one of the plurality of positions. You may employ | adopt the structure which heats a corresponding some area | region, respectively. In this way, when a temperature difference occurs at a plurality of positions, this temperature difference can be reduced.

In the display device of the present invention, the display means includes the display surface by a memory-type display body, and rewriting means for rewriting an image displayed on the display surface, and the switching means is configured to display the display by the rewriting means. A configuration in which the control by the heating control means is executed when the image of the surface is rewritten may be adopted. Note that the timing of starting the heating by the heating unit may be after the image is rewritten, or before the image is rewritten (or at the same time as the rewriting). In this way, unnecessary heating can be prevented from being performed during a period in which rewriting is not performed, that is, a period in which the display state is maintained, so that power consumption can be suppressed.

  In addition, the display device of the present invention includes a first supply unit that supplies power from a power source built in the device, and a second supply unit that supplies power from a power source external to the device. Performs control by the heating control means when electric power can be supplied by the second supply means, and performs control by the heating control means when electric power cannot be supplied by the second supply means. You may employ | adopt the structure which is not performed. In this way, when the display device is portable, it is possible to suppress power consumption when external power supply cannot be expected, such as when carrying the device, and to suppress a decrease in display time.

  In addition, this invention can be specified not only as the display apparatus mentioned above but as a display apparatus provided with the stand apparatus for mounting a display apparatus, and a display apparatus and a stand apparatus. For example, the stand device according to the present invention includes a heating unit that heats the display device when the display device is placed, an acquisition unit that acquires information from the display device, and information acquired by the acquisition unit. Accordingly, a heating control means for controlling heating by the heating means is provided.

Embodiments of the present invention will be described below with reference to the drawings.
[First Embodiment]
FIG. 1 is a block diagram illustrating a configuration of a display device 100 according to an embodiment of the present invention. FIG. 2 is a diagram showing the appearance of the display device 100. As shown in FIG. 1, the display device 100 includes a first power supply unit 110, a second power supply unit 120, a display body driving unit 130, a memory display unit 140, a data supply unit 150, and a sensor 160. A heater 170, a heater control unit 180, and an operation unit 190.

  The first power supply unit 110 supplies power from the built-in battery 111 to the display body drive unit 130, the data supply unit 150, and the heater control unit 180. The battery 111 is preferably a rechargeable secondary battery, but may be a primary battery such as a dry battery. The second power supply unit 120 includes a plug and a converter, and supplies power supplied from a power supply outside the display device 100 to the display body driving unit 130, the data supply unit 150, and the heater control unit 180. That is, the display device 100 operates using at least one of a built-in power source and an external power source. The display body drive unit 130 includes a drive circuit for driving the memory-type display body 140, and supplies a drive voltage corresponding to the display data supplied from the data supply unit 150 to the memory-type display body 140.

  The memory display body 140 is a display body having a liquid crystal layer made of memory liquid crystal, and constitutes a display surface 140D shown in FIG. Here, the memory liquid crystal is liquid crystal that can maintain a display state (that is, gradation) without applying a voltage. As the memory liquid crystal, for example, cholesteric liquid crystal is used. The memory-type display body 140 has pixels of a plurality of rows and a plurality of columns, and each pixel has a gradation corresponding to the supplied display data. The number of gradations of each pixel of the memory display 140 is arbitrary.

The data supply unit 150 includes an arithmetic processing unit such as a CPU (Central Processing Unit) and a storage medium such as a flash memory, and supplies display data to the display body driving unit 130. The display data is data indicating the gradation, that is, the density of each pixel of the memory display 140. The data supply unit 150 may store display data in advance, or may generate display data from other data. Each time the data supply unit 150 supplies display data to the display body driving unit 130, the data supply unit 150 outputs a signal indicating that to the heater control unit 180. This signal is hereinafter referred to as a “rewrite signal”.

  The sensor 160 detects the temperature of the display surface and outputs a detection signal representing this to the heater control unit 180. The sensor 160 is a thermistor, for example. The sensor 160 is provided close to the display surface at an appropriate position on the back side of the display surface, that is, the side not exposed to the outside of the display surface. However, the sensor 160 only needs to be at a position where the ambient temperature can be regarded as substantially the same as the display surface, that is, a position in the vicinity of the display surface, and need not be provided close to the back side of the display surface. . The sensor 160 is preferably provided with a so-called heat shield or the like so as not to be affected by the heat generated by the heater 170.

  The heater 170 is a planar heater having substantially the same area as the display surface, and uniformly heats the entire display surface from the back side. The heater 170 includes, for example, a planar resistor that generates heat, and a pair of electrodes that supply electric power to the resistor. The heater control unit 180 controls heating by the heater 170 by controlling electric power supplied to the heater 170. The heater control unit 180 performs this control based on the detection signal from the sensor 160. For convenience of explanation, in the present embodiment, the data supply unit 150 and the heater control unit 180 are described separately, but these functions may be realized by the same arithmetic processing unit or the like.

  The operation unit 190 includes operation keys 191, 192, 193, and 194 shown in FIG. 2 and accepts an operation by an operator. When the operation unit 190 accepts an operation by the operator, the operation unit 190 outputs an operation signal corresponding to the operation to the data supply unit 150.

The configuration of the display device 100 of the present embodiment is as described above. Next, operations performed by the display device 100 will be described.
The display device 100 displays an image corresponding to the display data. Specifically, the data supply unit 150 of the display device 100 supplies display data corresponding to each pixel of the memory-type display body 140 to the display body driving unit 130, and the display body driving unit 130 responds to the display data. The drive voltage thus applied is applied to each pixel of the memory display 140. The data supply unit 150 supplies display data to the display body driving unit 130 at a predetermined timing such as when an operation signal is acquired from the operation unit 190, and rewrites an image displayed on the display surface. At this time, the data supply unit 150 outputs a rewrite signal to the heater control unit 180.

  When the display device 100 performs such display, the heater control unit 180 controls on / off of the heater 170. The heater control unit 180 performs this control based on a detection signal from the sensor 160. In short, this control is performed in order to keep the display surface at a substantially constant temperature. Here, it is assumed that the temperature around the display device 100 is a temperature under a normal use environment indoors and outdoors, and is about 30 ° C. at the highest.

  FIG. 3 is a flowchart showing processing executed by the heater control unit 180. This process is repeatedly executed while the display device 100 is operating. As shown in the figure, the heater control unit 180 first determines whether or not the display surface has been rewritten within a predetermined period from the start of this process (step Sa1). The heater control unit 180 makes this determination based on the rewrite signal from the data supply unit 150. Here, when the display surface is not rewritten (step Sa1: NO), the heater control unit 180 ends the process.

On the other hand, when the display surface is rewritten within a predetermined time (step Sa1: YES), the heater control unit 180 determines whether power is supplied from the second power supply unit 120 (step). Sa2). When power is not supplied from the second power supply unit 120 (step Sa2: NO), the heater control unit 180 ends the process. That is, the heater control unit 180 executes a process that will be described later when the display surface is rewritten within a predetermined time and power is supplied from the second power supply unit 120, and otherwise the process will be described later. This means that no processing is performed.

  When power is supplied from the second power supply unit 120 (step Sa2: YES), the heater control unit 180 specifies the temperature at that time (step Sa3). The heater control unit 180 specifies the temperature by acquiring a detection signal from the sensor 160. Next, the heater control unit 180 determines whether or not the specified temperature is equal to or lower than a predetermined temperature (step Sa4). Here, the predetermined temperature is, for example, about 33 to 35 ° C. This value is determined in consideration of the surface temperature of the human skin.

  When the temperature is equal to or lower than the predetermined value (step Sa4: YES), the heater control unit 180 supplies power to the heater 170 to perform heating (step Sa5), and then periodically repeats the processing from step Sa3. . On the other hand, when the temperature is not lower than the predetermined value (step Sa4: NO), the heater control unit 180 stops supplying power to the heater 170 (step Sa6) and repeats the processing from step Sa1.

  By operating in this way, the temperature detected by the sensor 160 is controlled within a predetermined range. This is because the processing of steps Sa3 to Sa5 is repeatedly executed. That is, the temperature detected by the sensor 160 is determined. When the temperature is lower than or equal to a predetermined temperature, heating by the heater 170 is performed, and when the temperature exceeds the predetermined temperature, the heating 170 is stopped. By repeatedly executing the above, the temperature detected by the sensor 160 is always a value in the vicinity of the predetermined temperature, and does not exceed the determined range.

  Accordingly, the display surface of the display device 100 is maintained at a substantially constant temperature when the image is rewritten with a certain frequency. Thereby, for example, even if the operator touches a part of the display surface with a finger, the region does not become hotter than other regions, and the display surface has uneven temperature. It is possible to suppress the occurrence. Therefore, in the display device 100 of the present embodiment, the temperature of the display surface becomes substantially uniform, and the occurrence of display unevenness can be suppressed.

  Further, the display device 100 of the present embodiment is configured not to perform heating by the heater 170 when the display surface is not rewritten. This is because the display surface of the display device 100 is configured by the memory display 140. As described above, since the memory-type display body 140 can maintain the display state without applying a voltage, the display quality does not deteriorate when rewriting is not performed. Therefore, it can be said that it is not necessary to keep the temperature of the display surface uniform at this time. By adopting such a configuration, the display device 100 of this embodiment can suppress wasteful power consumption.

  However, in the case of the configuration of the present embodiment, if the display surface is not rewritten for a long time, the temperature of the display surface may be uneven. If the display surface is rewritten in such a state, display unevenness due to temperature non-uniformity may occur. In order to avoid such an inconvenience, for example, the heating may be performed regardless of whether there is an instruction to rewrite the display surface. That is, the process of step Sa1 described above can be omitted.

Further, the display device 100 of the present embodiment is configured not to perform heating by the heater 170 when power is not supplied from the second power supply unit 120. This is because the capacity of the battery 111 tends to be limited when the portability of the display device 100 is taken into consideration. That is, when power cannot be supplied from an external power source, such as when the operator moves while carrying the display device 100, the operation of the display device 100 depends only on the built-in power source. Become. In such a case, if heating by the heater 170 is performed, the power consumption is increased by that amount, and the time during which display can be performed is reduced. In other words, the display device 100 according to the present embodiment employs a configuration in which heating by the heater 170 is not performed when power is not supplied from the second power supply unit 120, thereby suppressing a reduction in display time when being carried. It becomes possible.

  However, for example, when it is configured to be used indoors, the power supply from the second power supply unit 120 may be expected almost always. Therefore, in such a case, the heating by the heater 170 may be performed regardless of whether or not the power is supplied from the second power supply unit 120. That is, the process of step Sa2 described above can be omitted.

  In the present embodiment, the temperature detected by the sensor 160 is kept within a certain range by repeatedly executing the processing of steps Sa3 to Sa5. However, for example, the sensor may be detected by other methods such as PID control. The temperature detected by 160 may be kept within a certain range.

[Second Embodiment]
Subsequently, a second embodiment of the present invention will be described. In the present embodiment, the configuration for detecting the temperature and the configuration for heating the display surface are different from those in the first embodiment described above. Note that in the present embodiment, the same components as those in the first embodiment described above are denoted by the same reference numerals, and the description thereof is omitted as appropriate.

  FIG. 4 is a block diagram illustrating a configuration of the display device 200 according to the present embodiment. As shown in the figure, the display device 200 includes a first power supply unit 110, a second power supply unit 120, a display body drive unit 130, a memory display unit 140, a data supply unit 150, and a sensor unit. 260, a heater unit 270, a heater control unit 280, and an operation unit 190. That is, the display device 200 of the present embodiment is different from the display device 100 described above in the sensor unit 260, the heater unit 270, and the heater control unit 280. The appearance of the display device 200 is the same as that of the display device 100.

  The sensor unit 260 includes sensors 261, 262, 263 and 264. Each of the sensors 261 to 264 has the same configuration as the sensor 160 described above. Each of the sensors 261 to 264 is provided at a determined position. The heater unit 270 includes heaters 271, 272, 273 and 274. Each of the heaters 271 to 274 has the same configuration as the heater 170 described above, but its size (area) is different from that of the heater 170. The heaters 271 to 274 are approximately ¼ the size of the heater 170, and the combined size of the heaters 271 to 274 is substantially equal to the size of the heater 170.

FIG. 5 is a diagram illustrating a positional relationship between the sensors 261 to 264 and the heaters 271 to 274. In the figure, the four sides of the display surface are indicated by broken lines. As shown in the figure, the heaters 271 to 274 are provided so as to correspond to each of the four areas obtained by dividing the display surface into two parts vertically and divided into two parts left and right. Heat. In addition, each of the sensors 261 to 264 detects the temperature at a position included in any of the above-described four regions. That is, the sensor 261 and the heater 271 have a corresponding relationship, and similarly, the sensor 262 and the heater 272, the sensor 263 and the heater 273, and the sensor 264 and the heater 2 are the same.
Each of 74 has a corresponding relationship.

  The heater control unit 280 acquires a detection signal from each of the sensors 261 to 264 and controls electric power supplied to the corresponding heaters 271 to 274. Specifically, the heater control unit 280 specifies the temperature at each position based on the detection signals acquired from the sensors 261 to 264, and if the specified temperature has a temperature difference greater than or equal to a predetermined value, Heating by the heaters 271 to 274 is controlled so as to be small.

  FIG. 6 is a flowchart showing a process executed by the heater control unit 280. This process is repeatedly executed while the display device 100 is operating. As shown in the figure, the heater control unit 280 first determines whether or not the display surface has been rewritten within a predetermined period from the start of this processing (step Sb1), and then the second power supply It is determined whether power is supplied from the unit 120 (step Sb2). These processes are the same as the processes of steps Sa1 and Sa2 of the first embodiment described above. The heater control unit 280 controls the heating by the heater unit 270 when both of these determinations are positive.

  After the determination of steps Sb1 and Sb2, the heater control unit 280 specifies the temperature based on the detection signal from the sensor unit 260 (step Sb3). Specifically, the heater control unit 280 specifies the temperature at each position based on the detection signal output from each of the sensors 261 to 264. That is, at this time, the heater control unit 280 specifies the temperatures at the four locations shown in FIG. These positions correspond to the respective areas when the display surface is divided into four.

  Subsequently, the heater control unit 280 determines whether or not the identified temperature differences at the four locations are equal to or greater than a predetermined threshold (step Sb4). Specifically, the heater control unit 280 specifies the maximum value and the minimum value of the specified temperature, and determines whether or not these differences are equal to or greater than a predetermined threshold value. Note that this threshold value may be determined so as to enable display that is not recognized as display unevenness under the same driving conditions, and is, for example, about 2 to 3 (° C.).

When the temperature difference is equal to or greater than the threshold (step Sb4: YES), the heater control unit 280 determines the heater (271 to 274) corresponding to one or a plurality of sensors (any one of 261 to 264) whose detected temperature is relatively low. The power is supplied to any one of them to cause heating (step Sb5). For example, when the temperature detected by the sensor 261 is lower than the others, the heater control unit 280 supplies power to the corresponding heater 271. Thereafter, the heater control unit 280 repeats the processing from step Sb3.
On the other hand, when the temperature difference is less than the threshold (step Sb4: NO), the heater control unit 280 does not perform heating by the heater unit 270 (step Sb6), and repeats the processing from step Sb1.

  By operating in this way, the temperature detected by the sensors 261 to 264 is controlled so that the temperature difference is within a predetermined range. Thereby, for example, even when light is irradiated locally on the display surface, it is possible to suppress temperature unevenness caused by this light. Therefore, in the display device 200 of the present embodiment, the temperature of the display surface becomes substantially uniform, and the occurrence of display unevenness can be suppressed.

In the present embodiment, the process of keeping the temperature within the predetermined range is performed by determining whether the difference between the four specified temperatures is equal to or greater than the predetermined threshold. However, the temperature is maintained within the predetermined range. The processing for keeping the inside is not limited to this method. For example, the heater control unit 280 calculates the average value of the temperatures at four locations and applies the heater (any one of 271 to 274) corresponding to the sensor (any one of 261 to 264) that detects a temperature below this average value. Electric power may be supplied.

[Third Embodiment]
Subsequently, a third embodiment of the present invention will be described. The present embodiment is a display system including a display device and a stand device on which the display device is placed. In the present embodiment, the description of the same components as those in the first embodiment described above will be omitted as appropriate.

  FIG. 7 is a block diagram showing the configuration of the display system 30 of the present embodiment. FIG. 8 is a diagram showing the appearance of the display system 30. As shown in FIG. 7, the display system 30 includes a display device 300 and a stand device 400. The display device 300 includes a power supply unit 310, an interface unit 320, a display body driving unit 130, a memory display unit 140, a data supply unit 150, a sensor 160, and an operation unit 190. The stand device 400 includes a power supply unit 410, an interface unit 420, a heater 170, and a heater control unit 180.

  The power supply unit 310 corresponds to the first power supply unit 110 described above, and supplies power to each unit of the display device 300 with a built-in power supply. The interface unit 320 has a predetermined standard terminal, and transmits / receives information to / from the stand device 400. The sensor 160 outputs a detection signal to the interface unit 320, and the data supply unit 150 outputs a rewrite signal to the interface unit 320. The interface unit 320 transmits these signals to the stand device 400.

As shown in FIG. 8, the stand device 400 has a structure on which the display device 300 can be placed. In the stand device 400, a portion in contact with the back surface of the display device 300 is hereinafter referred to as a “mounting unit”.
The power supply unit 410 corresponds to the second power supply unit 120 described above, and supplies power to each unit of the stand device 400 by an external power source. The interface unit 420 has a connector corresponding to the terminal of the interface unit 320, and transmits and receives information to and from the display device 300. The interface unit 420 may supply power to the display device 300 together with transmission / reception of information. In addition, the heater 170 is provided in the mounting part mentioned above. In addition, the heater control unit 180 acquires a detection signal and a rewrite signal through the interface unit 420 and controls heating by the heater 170.

  The operation of the present embodiment is almost the same as the operation of the first embodiment described above except that the detection signal and the rewrite signal are exchanged via the interface units 320 and 420. However, in the present embodiment, since the heater control unit 180 operates only with the power from the second power supply unit 120, the process of step Sa2 is not necessary. Also, the processing of step Sa1 can be omitted. Therefore, also in the display system 30 of this embodiment, the same effect as the display device 100 of the first embodiment described above can be obtained.

[Modification]
In the above, the present invention has been described by exemplifying the first to third embodiments. However, the present invention is not limited to the embodiment described above, and can be implemented in various other forms. Therefore, here, an example of another embodiment will be described. Of course, it is possible to modify the above-described first to third embodiments as appropriate. For example, a configuration corresponding to the display device 200 of the second embodiment can be added to the display system 30 of the third embodiment.

In the above-described embodiment, the heating is controlled based on the detection signal from the sensor, but other information may be used instead of the detection signal. For example, if a contact-type sensor such as a touch screen (touch panel) is provided on the display surface, heating may be controlled based on a signal indicating the presence or absence of contact output from the sensor. In this case, furthermore, heating may be performed when contact for a predetermined time or more is recognized at the same position. This is because the temperature of the display surface may become non-uniform when the contacting object is an object having a higher temperature than the display surface.

  In the above-described embodiment, the heater control unit 180 (or 280) is configured to only control the heater on / off, but may be configured to continuously change the power supplied to the heater. In this way, electric power corresponding to the specified temperature can be supplied, so that the temperature of the display surface can be controlled with higher accuracy.

In the above-described embodiment, the data supply unit 150 is configured to output a rewrite signal each time display data is supplied to the display body driving unit 130. At this time, the data supply unit 150 may be configured such that the image is rewritten after a predetermined time has elapsed since the rewrite signal was output. In this way, heating can be started before the image on the display surface is rewritten.
However, in general, since sufficient time is required for sufficient heating by the heating means, if the time difference between the output timing of the rewrite signal and the rewrite timing of the image is slight, sufficient heating may not be performed at the time of rewriting the image. There is also sex. Therefore, for such a case, an operation key that allows the operator to instruct heating may be provided in the operation unit 190. In this case, the heater control unit 180 (or 280) may be configured to start heating by the heater 170 (or the heater unit 270) when an operation signal representing this instruction is acquired.

  In the first embodiment described above, the heater control unit 180 operates by receiving power supply from the first power supply unit 110 and the second power supply unit 120, but only from the second power supply unit 120. The structure which receives electric power supply may be sufficient. In such a configuration, when the second power supply unit 120 cannot supply power, the heater control unit 180 itself does not operate, and thus the same effect as in the first embodiment can be obtained. In this case, it can be said that the second power supply unit 120 functions as a unit that switches whether the heater control unit 180 can execute the control. This also applies to the second embodiment.

  Moreover, although 2nd Embodiment mentioned above was a structure which divided | segmented a display surface into four area | regions, and detected and heated the temperature of each area | region, of course, a display surface was divided | segmented into many more areas, The structure which detects and heats the temperature of each area | region may be sufficient. Moreover, the area and shape of each divided region need not be the same.

  In the second embodiment described above, the number of sensors and heaters is the same. However, the number of heaters may be larger than the number of sensors. For example, the heater unit may be configured such that a heater having a corresponding sensor and a heater not having a corresponding sensor are alternately arranged vertically and horizontally. In the case of this configuration, the temperature of the region corresponding to the heater not having the corresponding sensor may be estimated based on the temperature of the sensor corresponding to the heater adjacent to the heater. For example, in this configuration, since there are a plurality of heaters adjacent to the heater, it may be estimated by averaging the temperatures of the sensors corresponding to the plurality of heaters.

It is a block diagram which shows the structure of a display apparatus. It is a figure which shows the external appearance of a display apparatus. It is a flowchart which shows the process which a heater control part performs. It is a block diagram which shows the structure of a display apparatus. It is a figure which shows the positional relationship of a sensor and a heater. It is a flowchart which shows the process which a heater control part performs. It is a block diagram which shows the structure of a display system. It is a figure which shows the external appearance of a display system.

Explanation of symbols

DESCRIPTION OF SYMBOLS 100 ... Display apparatus, 110 ... 1st electric power supply part, 111 ... Battery, 120 ... 2nd electric power supply part, 130 ... Display body drive part, 140 ... Memory | storage display body, 150 ... Data supply part, 160 ... Sensor, 170 ... Heater, 180 ... Heater control unit, 190 ... Operating unit

Claims (5)

Display means having a display surface;
Detecting means for detecting a temperature in the vicinity of the display surface;
Heating means for heating the entire display surface;
A heating control means for controlling the heating by the heating means so that the temperature detected by the detecting means falls within a predetermined range;
And a switching means for switching whether to execute control by the heating control means. The detecting means detects temperatures at a plurality of positions on the display surface;
2. The display device according to claim 1, wherein each of the heating units includes a display surface and heats a plurality of regions corresponding to any of the plurality of positions. The display means includes the display surface by a memory-type display body, and rewriting means for rewriting an image displayed on the display surface,
The display device according to claim 1, wherein the switching unit performs control by the heating control unit when the image on the display surface is rewritten by the rewriting unit. First supply means for supplying power from a power source built in the device;
A second supply means for supplying power from a power supply external to the device itself,
The switching means executes control by the heating control means when electric power can be supplied by the second supply means, and when the electric power cannot be supplied by the second supply means, the heating control means The display device according to claim 1, wherein the control according to claim 1 is not executed. Heating means for heating the display device when the display device is placed;
Obtaining means for obtaining information from the display device;
A stand device comprising: a heating control unit that controls heating by the heating unit according to the information acquired by the acquiring unit.

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