JP2007147695A - Liquid crystal device and electronic equipment - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a constitution for enhancing operation grade in a low temperature environment by heightening temperature uniformity in a region where a liquid crystal is controlled in a liquid crystal device provided with an illumination device such as a backlight. <P>SOLUTION: The liquid crystal device 100 provided with a liquid crystal display body 110 constituted so that optical characteristics of the liquid crystal can be controlled and the illuminator 120 illuminating the liquid crystal display body, includes a heat generating body for heating the liquid crystal. The illuminator includes a light guide plate 122 two-dimensionally superposed on the liquid crystal display body and a light source 121 emitting light to be introduced in the light guide plate. The heat generating body is arranged corresponding to temperature distribution caused by heating to the liquid crystal display body by the illuminator and has a plurality of heat generating regions 118A and 118B constituted so that the regions can respectively independently function. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

The present invention relates to a liquid crystal device and an electronic apparatus, and in particular, includes a liquid crystal display configured to be able to control the optical characteristics of liquid crystal, an illumination device that illuminates the liquid crystal display, and a heating element that heats the liquid crystal display. The present invention relates to the configuration of a liquid crystal device.

In general, a liquid crystal display body configured to control liquid crystal such as liquid crystal like a liquid crystal display body is used in combination with an illumination device such as a backlight. For example, in a transmissive liquid crystal display or a transflective liquid crystal display, illumination light is necessary to enable transmissive display, and a backlight, a front light, or the like is used to provide this illumination light. .

In addition, since the response of liquid crystal deteriorates due to an increase in viscosity at a low temperature and the display quality deteriorates, for example, in a liquid crystal display device mounted on a vehicle, the liquid crystal display body is heated at the time of starting. Some have built-in heaters. As such a liquid crystal display, for example,
One that uses a black matrix for shielding light between pixels as a heater (for example, see Patent Document 1 below), or one that forms a layer made of a transparent conductor on the entire surface of a substrate (for example, the following patent) Document 2) is known.
JP-A-6-289370 JP 2000-47247 A

However, in the above-described liquid crystal display device with a built-in heater, when a backlight is arranged behind the liquid crystal display body, the heat received from the backlight is transferred to the liquid crystal display body, so the liquid crystal display body is lit at a low temperature. When this is done, a temperature difference occurs between the area that receives a lot of heat from the backlight and the area that receives a small amount of heat from the backlight. There is.

Therefore, the present invention solves the above-described problems, and the problem is that in a liquid crystal device equipped with a lighting device such as a backlight, the temperature uniformity in a region where the liquid crystal is controlled is improved, thereby reducing the temperature environment. An object of the present invention is to realize a configuration capable of improving the operation quality in the system.

In view of such circumstances, the liquid crystal device of the present invention is a liquid crystal device that includes a liquid crystal display configured to be capable of controlling the optical characteristics of the liquid crystal, and an illumination device that illuminates the liquid crystal display. The lighting device includes a light guide plate that overlaps the liquid crystal display body in a plane, and a light source that emits light introduced into the light guide plate. A plurality of heat generating regions are provided corresponding to a temperature distribution resulting from heating of the liquid crystal display by the lighting device and configured to be able to function independently of each other.

According to the present invention, the heating element for heating the liquid crystal is provided with a plurality of heating regions configured to function independently of each other, and the plurality of heating regions are provided in the liquid crystal display body by the lighting device. When the heat generated by the light source of the lighting device is applied to the liquid crystal, the plurality of heat generating regions are heated differently according to the temperature distribution generated by the heat. By controlling the density (a calorific value per unit area), the influence of heat from the light source can be appropriately adjusted.

In the present invention, the plurality of heat generating regions are preferably formed separately from each other. According to this, since the plurality of heat generation regions are separated from each other, the thermal influence between the heat generation regions can be reduced, so that the above temperature distribution can be controlled more efficiently. In particular, it is desirable that the plurality of heat generating regions be formed to have a planar pattern that is separated from each other in a planar manner.

In the present invention, the heating element is configured to heat the liquid crystal by a resistance heating method, and when the same voltage or the same current is applied, the heating area is disposed in a range relatively close to the light source. It is preferable that the heat generation density of the heat generation region disposed in a range relatively far from the light source is relatively large. According to this, when the same voltage is applied in parallel to each heat generating area, or when the same current flows by connecting each heat generating area in series, heat generation in the heat generating area close to the light source. Because the density is small and the heat generation density in the heat generation area far from the light source can be increased,
The variation in temperature caused by the heat generated by the light source can be alleviated, and at the same time, the power supply system can be easily configured.

In the present invention, it is preferable to further include a heat generation control unit capable of independently controlling a plurality of the heat generation regions in the heat generating element. According to this, by allowing the heat generation control unit to control the plurality of heat generation regions independently, the heating mode of the liquid crystal display by the plurality of heat generation regions can be arbitrarily set according to the heat generated by the light source.

In the present invention, by the heat generation control unit, the heat generation area disposed in a range relatively close to the light source has a relatively low heat generation density, and the heat generation disposed in a range relatively far from the light source. It is preferable that the region is controlled to have a relatively high heat generation density. According to this, the heat generation area arranged in the range relatively close to the light source, which is easily affected by the heat generated by the light source, has a low heat generation density and is not easily affected by the heat generated by the light source. Since the heat generation area arranged in a relatively far range has a high heat generation density, it is possible to suppress temperature variations due to heat generated by the light source.

Next, another liquid crystal device according to the present invention is a liquid crystal device including a liquid crystal display body configured to control liquid crystal and an illumination device that illuminates the liquid crystal display body, and generates heat for heating the liquid crystal. The lighting device includes a light guide plate that overlaps the liquid crystal display body in a plane and a light source that emits light introduced into the light guide plate, and the heating element is formed by the lighting device. It has a plurality of heat generating regions which are provided corresponding to the temperature distribution resulting from the heating of the liquid crystal display and are configured to generate different heat generation densities.

In the present invention, the first heat generation area disposed on the light source side and the second heat generation area including one portion disposed on the opposite side of the first heat generation area from the light source. And the other part of the second heat generation region may extend from the one part to the light source side along the outer edge of the first heat generation region. Usually, the plurality of heat generating regions according to the present invention are provided in ranges where the distances to the light sources are different from each other. However, for example, even if the first heat generation area is arranged on the light source side and one part of the second heat generation area is arranged on the side opposite to the light source of the first heat generation area,
The other part of the second heat generation region may extend from the one part to the light source side along the outer edge of the first heat generation region. In this case, even if the distance between the other part of the second heat generation region and the light source is equal to or less than the distance between the first heat generation region and the light source, one of the first heat generation region and one of the second heat generation regions Since the distance from the light source is different from the portion, the temperature distribution of the liquid crystal display due to the lighting device can be relaxed by the heating element.

In the present invention, the heat generation area having a relatively low heat generation density disposed in a range relatively close to the light source, and the heat generation area having a relatively high heat generation density disposed in a range relatively far from the light source. It is preferable to have.

In this invention, it is preferable that the said heat_generation | fever area | region is comprised with the heat_generation | fever layer arrange | positioned in contact with the said liquid crystal display body in the plane area | region at least controlled. According to this, since heat can be directly transferred to the liquid crystal display, heating can be performed efficiently and effectively.

In this invention, it is preferable that the said heat_generation | fever area | region is comprised with the heat_generation | fever layer which consists of a transparent material arrange | positioned in the plane area | region where at least control of the said liquid crystal display is performed. According to this, since the heat-generating layer is made of a transparent material, the optical influence of the heat-generating layer can be reduced. For example, the heat-generating layer can be formed entirely in the planar region. It is possible to freely set the pattern shape of the heat generating layer and the position where the heat generating layer is formed.

In the present invention, the heat generating area is constituted by a heat generating layer disposed in at least a planar area where the liquid crystal display body is controlled, and the heat generating layer is disposed between the liquid crystal and the lighting device. It is preferable. According to this, the heat generation layer is disposed between the liquid crystal and the lighting device, so that the thermal effect of the liquid crystal display body from the lighting device side is shielded or mitigated to some extent by the heat generation layer itself. At the same time, the liquid crystal can be efficiently heated.

In addition, the above heat generation layer is at least in a plane region where the liquid crystal display is controlled,
It is preferable to be configured as an integral surface. Moreover, it is desirable to arrange | position to the said whole planar area | region except the boundary part of several heat_generation | fever area | regions.

In the present invention, it is preferable that a change width of the distance to the light source in the arrangement range of the heat generation area relatively close to the light source is smaller than the change width of the arrangement range of the heat generation area relatively far from the light source. . According to this, since the portion near the light source is easily affected by the heat generated by the light source, the temperature gradient due to the influence increases, whereas the portion far from the light source is not easily affected by the heat generated by the light source. Therefore, the temperature gradient due to the influence becomes small. Therefore, the temperature gradient due to the heat generated by the light source can be achieved by configuring the arrangement range of the heat generation area close to the light source so that the change width of the distance to the light source is small and the arrangement range of the heat generation area far from the light source is large Can be effectively relaxed.

In the present invention, it is preferable that the plurality of heat generating regions have a planar range separated along an isothermal region of a temperature distribution resulting from heating of the liquid crystal display by the lighting device. According to this, since the planar ranges of the plurality of heat generating regions are separated along the isothermal region of the temperature distribution of the liquid crystal display body by the lighting device, the heating mode can be changed corresponding to the temperature distribution. Therefore, the controllability of the temperature distribution of the liquid crystal display can be further enhanced.

An electronic apparatus according to the present invention includes any one of the above liquid crystal devices. Examples of such electronic devices include in-vehicle devices such as car navigation systems, in-vehicle watches, in-vehicle acoustic devices, in-vehicle monitors, and electronic meter panels, and portable electronic devices such as GPS (global position detection system) and mobile phones. Etc. are preferable.

Next, embodiments of the present invention will be described in detail with reference to the accompanying drawings. FIG. 1A is a schematic longitudinal sectional view of the liquid crystal device 100 of the present embodiment, and FIG. 1B is a schematic plan view showing a planar arrangement of the illumination device and the heat generating layer of the liquid crystal device 100.

The liquid crystal device 100 includes a liquid crystal display body (liquid crystal display body) 110 that uses liquid crystal as a liquid crystal, and an illumination device 120 that is disposed to overlap the liquid crystal display body 110 in a planar manner.

The liquid crystal display 110 is formed by bonding transparent substrates 111 and 112 made of glass, plastic, or the like with a sealant 113 at a predetermined interval (about 3 to 10 μm), and enclosing the liquid crystal 114 between the substrates 111 and 112. . A wiring substrate 117 such as a flexible wiring substrate (FPC) is mounted on the substrate 111, and a predetermined potential or a control signal is supplied to the wiring (not shown) through the wiring substrate 117, so that a liquid crystal 114 encapsulating region is provided. A predetermined potential can be supplied to an electrode (not shown) arranged inside.

A heating element 118 is disposed in contact with the liquid crystal display 110 as a heating element. In the case of the illustrated example, the heating element 118 is formed of a heating layer made of a transparent conductor such as ITO (indium tin oxide) disposed in the display area A of the liquid crystal display 110. Thus, since the heat generating body 118 has translucency, it can be formed in a free plane pattern without greatly affecting the optical characteristics of the liquid crystal device 100, and the degree of freedom of the installation position can be secured. . Here, the display area A is a planar area in which the liquid crystal (liquid crystal 114 in the illustrated example) in the liquid crystal display body 110 is configured to be controllable, that is, a drive area or a control area. actually,
In the display area A, a plurality of pixels (not shown) configured to be independently controllable are arranged vertically and horizontally. The pixel is a minimum unit plane region controlled by an electrode that applies an electric field to the liquid crystal (liquid crystal 114).

The heat generating body 118 has two heat generating layers 118A and 118B, and the heat generating layers 118A and 118B.
B is configured to be able to function independently of each other. Specifically, in the illustrated example, the heating layer 11
8A and 118B are formed to have a pattern separated in a plane. Further, the heat generating layers 118A and 118B both have a portion disposed in the display area A. Heat generation layer 11
8A and 118B each have two terminal portions (potential supply portions) 11 for receiving power supply.
9A and 119B, and these terminal portions 119A and 119B are arranged outside the display area A. These terminal portions 119A and 119B are formed of a metal film or the like laminated on the heating elements 118A and 118B.

As described above, in the present embodiment, since the power supply layers 118A and 118B are provided with the power supply terminal portions 119A and 119B, respectively, power can be supplied independently to the heat generation layers 118A and 118B. it can. Therefore, these heat generating layers 118A and 118B
Are configured to function independently of each other. However, even in the case of such a configuration, as will be described later, one of the terminal portions 119A and 119B is conductively connected by the conductive connection portion X shown by a dotted line in FIG. And 118B are connected in series, and a predetermined voltage can be applied between the other terminal portions 119A and 119B to which the conductive connection portion X is not connected.

In the illustrated example, the heat generation layers 118A and 118B are deposited on the outer surface of the substrate 111 (the surface opposite to the side facing the substrate 112). The heat generating layers 118A and 118B are preferably formed by a vapor deposition method such as an evaporation method or a sputtering method.

A polarizing plate 115 is disposed (attached) on the heating element 118. A polarizing plate 116 is disposed (attached) on the outer surface of the substrate 112 (the surface opposite to the surface facing the substrate 111).

On the other hand, the illuminating device 120 has a light source 121 composed of LEDs (light emitting diodes) and the like, and light from the light source 121 is incident from the light incident surface 122a which is an end surface and propagates through the inside.
A light guide plate 122 made of a light guide material (transparent material) such as acrylic resin or polycarbonate resin, which is configured to be emitted from the light emission surface 122b on the liquid crystal display 110 side, and the light emission of the light guide plate 122. A reflecting plate 123 made of polyethylene resin or metal material is provided on the back surface 122c opposite to the surface 122b. The light source 121 is a wiring board 127.
It is mounted on top and is supplied with power via this wiring board 127.

The light guide plate 122 is configured and arranged such that the light emission surface 122b thereof overlaps the entire display area A of the liquid crystal display 110 in a planar manner. Further, the light exit surface 122 is gradually transmitted to the light guide plate 122 while the light from the light source 121 is propagated from the right side to the left side in the drawing.
A light deflecting means for deflecting toward the b side, for example, a plurality of light deflecting slopes (not shown) formed on the back surface 122 is provided.

In this embodiment, the light source 121 is essentially a point light source such as an LED, and a plurality of the point light sources are arranged in the width direction of the light incident surface 122a of the light guide plate 122. Instead of the plurality of point light sources, a linear light source such as a cold cathode tube may be used. In the present embodiment, the liquid crystal display 110 is directly disposed on the light exit surface 122 b of the light guide plate 122. However, a light diffusing plate or a light collector is provided between the light guide plate 122 and the liquid crystal display 110. An optical sheet such as the above may be interposed.

In the present embodiment, the heat generating layer 118 </ b> A of the heating element 118 is disposed in a planar range near the light source 121 of the lighting device 120, and the heat generating layer 118 </ b> B is disposed in a planar range far from the light source 121. That is, the heat generating layers 118A and 118B are respectively arranged in a band shape in the region on the light source 121 side and the region on the opposite side. In other words, in the present embodiment, the display area A is divided by the dividing line S into a plane range on the light source 121 side (range on the right side in the figure) and a plane range on the opposite side to the light source 121 (range on the left side in the figure). The heat generating layers 118A and 118B of the heat generating body 118 are disposed in the respective plane ranges separated by the dividing line S. In the illustrated example, an appropriate gap (slit along the dividing line S) is provided between the heat generating layers 118A and 118B to ensure insulation.

In the present embodiment configured as described above, the heat generation layer 118A close to the light source 121 reduces the heat generation density, and the heat generation layer 118B far from the light source 121 increases the heat generation density, thereby affecting the heat generated by the light source 121. Even if it receives, it can comprise so that the temperature variation of the liquid crystal display body 110 may become difficult to produce.

More specifically, when the illuminating device 120 illuminates the liquid crystal display 110, the temperature of the light guide plate 122 on the light source 121 side is high due to the heat generated by the light source 121, and the light source 121.
A temperature gradient is formed such that the temperature decreases as the distance from the distance increases. Therefore, even when the liquid crystal display 110 is uniformly heated by the heating element 118, the lighting device 120 is provided in the liquid crystal display 110.
Variations in temperature reflecting the temperature gradient of.

In particular, since the light conductivity of the light guide plate 122 of the lighting device 120 and the substrates 111 and 112 of the liquid crystal display 110 is relatively low, the heat generated by the light source 121 is planar along the light guide plate 122 and the substrates 111 and 112. Since it is difficult to transmit, a large temperature difference of about 7 to 10 ° C. for a 2-inch display body and about 22 ° C. for a 7-inch display body is usually generated in the display area A by heat generated by the light source 121. Examples of these temperature differences are data in a steady state after a certain amount of time has elapsed after the lighting device 120 is turned on, but even when the device is started, a large temperature difference can occur in a low temperature environment. .

However, in the present embodiment, the heat generating layer 118A close to the light source 121 and the heat generating layer 118B far from the light source 121 are configured to be able to function independently, so that each operates or controls in a different manner. It becomes possible. Further, the plurality of heat generating layers 118A, 11
Since 8B is formed separately from each other, the thermal influence between them can be reduced, so that the influence due to the temperature gradient caused by the lighting device 120 can be reduced.

In the present invention, the heat generation layers 118A and 118B may be configured to have different heat generation densities. That is, the heat generation layers 118A and 118B are configured to exhibit different heat generation densities even when the control amounts are the same, or the heat generation layers 118A and 118B are controlled so as to exhibit different heat generation densities.

In the former case, the heat generating layers 118A and 118B may have different materials. For example, by forming the heat generation layers 118A and 118B with materials having different heat generation characteristics, even when the same voltage or the same current is applied, the heat generation density (the heat generation amount per unit area and unit time) differs from each other. Can be. Also, the heat generation layers 118A and 118B
Even if they are configured to have different thicknesses, they can have different heat generation densities when the same voltage is applied.

In the case of this embodiment, when the same voltage is applied in parallel to the heat generating layers 118A and 118B, or the heat generating layers 118A and 118B are connected in series by providing a conductive connection portion X indicated by a dotted line in FIG. In the case where the same current is caused to flow by connection or the like, the heat generation density of the heat generation layer 118A may be relatively small and the heat generation density of the heat generation layer 118B may be relatively large.

In the present embodiment, the heating element 118 heats the liquid crystal display by a resistance heating method.
For example, when the same voltage is applied in parallel, it depends on the heat generation characteristics of the material, but for convenience of explanation, when it is assumed that the heat generation characteristics depend only on power consumption, The surface area resistivity is relatively high in the heat generation area arranged in the near range, and the surface area resistivity is relatively low in the heat generation area arranged in the range relatively far from the light source. What is necessary is just to comprise. More specifically, even if the thickness is the same, the heat generating layer 118A may be made of a material having a high resistivity, and the heat generating layer 118B may be made of a material having a low resistivity, and the resistivity is the same. Alternatively, the heat generating layer 118A may be thin and the heat generating layer 118B may be thick.
Note that the resistivity and thickness may be changed in combination.

In addition, when the same current flows, it depends on the heat generation characteristics of the material, but for convenience of explanation, if it is assumed that the heat generation characteristics depend only on power consumption as described above, it is relative to the light source. The surface area resistivity is relatively low in the heat generation area disposed in a range close to the area, and the surface area resistivity is relatively high in the heat generation area disposed in a range relatively far from the light source. What is necessary is just to comprise. More specifically, even if the thickness is the same, the heat generating layer 118.
A may be made of a material having a low resistivity and the heat generating layer 118B may be made of a material having a high resistivity. Even if the resistivity is the same, the heat generating layer 118A is made thick and the heat generating layer 118B is made thin. Also good. Note that the resistivity and thickness may be changed in combination.

In this case, the same voltage may be applied in parallel to the heat generating layers 118A and 118B, or the heat generating layers 118A and 118B may be connected in series.
It is possible to easily configure a power supply system and a control system for.

On the other hand, in the latter case, for example, the heat generation density can be changed by applying different voltages to the heat generation layers 118A and 118B. In this case, it is preferable to control the heat generation density of the heat generating layers 118A and 118B by providing a heat generation control unit that controls the heat generating body 118.

FIG. 5 is a schematic configuration diagram illustrating an example of the heating element HT including the heating element 118 and a heating element control unit HS that controls the heating element 118 according to the present embodiment. In the present embodiment, as described above, the same voltage is applied to the plurality of heat generation layers 118A and 118B or connected in series, and a single power supply system is used for the plurality of heat generation layers. Power supply may be performed. However, the heating element HT shown in FIG. 5 is configured such that power can be supplied to the heating layers 118A and 118B under independent conditions.

The heating element HT supplies power to the heating element 118 by the heating element control unit HS, and the heating element 118 is heated.
Then, heat is generated by resistance heating based on the electric power. The heating element control unit HS includes a controller T configured by a control circuit, a microprocessor unit, and the like, and power supply units DA and DB that operate based on a control signal output from the controller T. The power supply unit DA supplies power to the heat generating layer 118A through the terminal unit 119A, and the power supply unit DB supplies power to the heat generating layer 118B through the terminal unit 119B. Accordingly, the heating element control unit HS of the present embodiment is configured to be able to control the heating layers 118A and 118B independently as described above. Specifically, the heat generation layers 118A, 1 by the power supply units DA, DB
By appropriately setting the voltage applied to 18B as a control amount, the heat generating layers 118A and 118
Regardless of the heat generation characteristics, resistivity, thickness, etc. of B, the heat generation density of the heat generation layers 118A, 118B can be appropriately set in an independent state.

Further, the heating element HT is provided with temperature sensors SA and SB for detecting the temperature of the heating layers 118A and 118B or the temperature of the liquid crystal display body 110 to be heated, and the temperature sensor SA.
, SB may be configured such that the controller T controls the heating mode of the heating element 118 based on the temperature detected by the SB. In the case of the illustrated example, the temperature sensor SA (the heat generating layer 11) corresponding to the heat generating layer 118A.
8A, or a sensor that detects the temperature in the vicinity of the portion of the liquid crystal display 110 that overlaps the heating layer 118A in a plane, and a temperature sensor SB corresponding to the heating layer 118B (in the vicinity of the heating layer 118B, or And a sensor for detecting the temperature in the vicinity of the portion of the liquid crystal display 110 that planarly overlaps the heat generation layer 118B, and the heat generation layer 118A based on the temperatures detected by these temperature sensors SA and SB. And 118B can be separately temperature controlled.

Further, in the present embodiment, since the heat generating layers 118A and 118B are formed in a planarly separated form, the thermal influence between the two heat generating layers is relatively reduced, and the heat influence by the lighting device 120 is more effective. Compensation becomes possible. However, the heat generation layers 118A and 118B only have to be configured to function independently of each other. For example, a planar overlap between the two arrangement ranges may partially occur. The functioning independently means that, for example, in the case of having a plurality of resistance heating type heat generation layers as in the present embodiment, it is possible to generate power by separately supplying power to the plurality of heat generation layers. To do. In this case, the plurality of heat generating layers may or may not be in communication with each other, but are preferably insulated from each other as in this embodiment.

In this embodiment, the two heat generation layers 118A and 118B are provided to divide the heat generation region that can realize different heating modes into two, but three or more heat generation regions are included in a range having different distances from the light source 121. May be provided.

In the present embodiment, the length LA of the heat generation layer 118A when viewed in the direction away from the light source 121 (the left-right direction in the figure) (that is, the change width of the distance to the light source 121 in the arrangement range of the heat generation layer 181A) LA is It is formed smaller than the length 118B (change width) LB. This is because the temperature gradient is large because the heat generated by the light source 121 is large in the region close to the light source 121, and the temperature gradient is small because the heat generated in the light source 121 is small in the region far from the light source 121. It is. That is, the light source 121 having a large temperature gradient.
By setting the range LA of the heat generating layer 118A arranged in the region close to the area narrow and setting the range LB of the heat generating layer 118B arranged in the area far from the light source 121 where the temperature gradient is small, the above temperature gradient is large. Since the temperature difference based on the above temperature gradient in the heating range covered by the heat generating layer 118A formed in the planar range can be reduced, the heat generating layers 118A and 11
Compared with the case where the range of 8B is set to the same length, the temperature gradient caused by the illumination device 120 can be efficiently relaxed.

Further, as the performance of the heating element, for example, the temperature difference of the liquid crystal in the display area A is at least a predetermined temperature or less (for example, 0 ° C. or less, 5 ° C. or less, etc.) when the external environmental temperature is uniform.
It is preferable that the temperature is always 5 ° C. or lower. Normally, when the liquid crystal device is started, the light source 121 is turned on and the heating element is activated, the heating element 118 generates heat, and the power supply to the heating element 118 is cut off when the temperature rises to some extent. Although the influence on the display quality due to the temperature difference is small at a high temperature, the thermal influence due to the heat generation of the light source 121 is particularly large at a low temperature, so that the temperature difference becomes a certain value or less at a predetermined temperature or less. It is preferably configured (controlled).

FIG. 2 is a schematic plan view showing a planar structure of an illumination device and a heating element of an embodiment different from the above embodiment. In this embodiment, the heat generating layer 118A ′ and the heat generating layer 118 of the heat generating body 118 ′.
The boundary edges 118As ′ and 118Bs ′ on the side adjacent to B ′ are located farther from the light source 121 at the center in the width direction of the light guide plate 112, and the light source is moved toward the both ends in the width direction of the light guide plate 112. It is configured in a convex curved shape when viewed in a direction away from the light source 121 so as to be relatively close to 121.

In the present embodiment, the temperature distribution due to the thermal influence of the lighting device 120 is high at the center in the width direction of the light guide plate 112 as shown by the dotted line in the figure, and is lower as it moves to both ends of the light guide plate 112 in the width direction. It has become. This is because the influence of the heat generated by the light source 121 is strong in the central portion in the width direction of the light guide plate 121 and becomes weaker as it moves to both ends in the width direction. A temperature distribution having the same tendency is formed. Such temperature distribution occurs when the side surfaces of the lighting device 120 and the liquid crystal display body 110 are exposed to the outside, or when stored in a case body (for example, a resin case) with low thermal conductivity. .

In the device in which the temperature distribution caused by the lighting device 120 as described above is generated, a plurality of heat generation regions (heat generation layers) are separately formed in a divided manner along the isothermal region of the temperature distribution, that is, as illustrated in FIG. By dividing the heating element 118 ′ along the dividing line S ′, the temperature distribution can be most effectively relaxed.

FIG. 3 is a schematic plan view showing a planar structure of a lighting device and a heating element of still another embodiment. In this embodiment, the boundary edges 118As ″ and 118Bs ″ on the sides adjacent to each other of the heat generating layer 118A ″ and the heat generating layer 118B ″ of the heat generating body 118 ″ are relatively close to the light source 121 at the center in the width direction of the light guide plate 112. The light source 12 is positioned so as to move to both ends of the light guide plate 112 in the width direction.
It is configured in a concave curved shape when viewed in a direction away from the light source 121 so as to be relatively far from 1.

In the present embodiment, the temperature distribution due to the thermal influence of the lighting device 120 is low at the center in the width direction of the light guide plate 112 as shown by the dotted line in the figure, and is higher as it moves toward both ends of the light guide plate 112 in the width direction. It has become. This is because the influence of the heat generated by the light source 121 is weak at the central portion in the width direction of the light guide plate 121 and becomes stronger as it moves to both ends in the width direction. A temperature distribution having the same tendency is formed. Such a temperature distribution occurs when the side surfaces of the lighting device 120 and the liquid crystal display body 110 are stored in a case body (for example, the illustrated metal case 131) having high thermal conductivity.

Even in the device in which the temperature distribution caused by the lighting device 120 as described above occurs, a plurality of heat generation regions (heat generation layers) are separately formed in a divided manner along the isothermal region of the temperature distribution, that is, as illustrated in FIG. By dividing the heating element 118 ″ along the dividing line S ″, the temperature distribution can be most effectively relaxed.

FIG. 4 is a schematic plan view showing a planar structure of a lighting device and a heating element of still another embodiment. In this embodiment, in the illumination device 120 ′, the light source 1 is provided on both sides of the light guide plate 122 ′.
21A and 121B are respectively arranged, and both end surfaces of the light guide plate 122 ′ are light incident surfaces 12 respectively.
It differs from the previous embodiment in that it is 2a. The heating element 138 includes a light source 121A.
A heat generating layer 138A disposed in a range close to the light source 121B, a heat generating layer 138B disposed in a range close to the light source 121B, and a heat generating layer 138C disposed between the heat generating layers 138A and 138B. That is, the heat generating layers 138A and 138C are separately formed on both sides of the dividing line Sa, and the heat generating layer 138B is formed.
And 138C are formed separately on both sides of the dividing line Sb.

In this embodiment, since the light sources 121A and 121B are respectively arranged on both sides, the heat generating layer 138A close to the light source 121A and the heat generating layer 138B close to the light source 121B are separately provided and further separated from both light sources. By providing the heating layer 138C at the position, the light source 121A
And the thermal influence by 121B can be relieved.

The temperature distribution resulting from the illumination device 120 may be the temperature distribution of the light guide plate 122 or the temperature distribution of the liquid crystal display 110. However, since the purpose is to obtain temperature uniformity of the liquid crystal display 110 itself, the temperature distribution of the liquid crystal display 110 itself is preferable, and the temperature distribution of the liquid crystal is particularly preferable.

FIG. 6 is a schematic enlarged longitudinal sectional view showing an example of a detailed structure of the liquid crystal display body of the above embodiment.
The liquid crystal display 110 includes a light transmission region that transmits light incident from the side opposite to the viewing side,
A transflective structure having a light reflecting region for reflecting external light on the viewing side.

On the inner surface of the substrate 111 (the surface facing the substrate 112), wiring and switching elements (TF)
A drive structure 111U in which a three-terminal non-linear element such as T or a two-terminal non-linear element such as TFD is stacked via an appropriate interlayer insulating film, and an insulator such as a resin is provided thereon. An insulating layer 141 configured, a reflective layer 142 configured of a reflective material such as a metal thin film, an electrode 143 configured of a transparent conductor such as ITO, and an alignment film 144 configured of polyimide resin are sequentially stacked. . The reflection layer 142 forms a light reflection region Rr for each pixel G, and the reflection layer 142
The portion where no is formed constitutes the light transmission region Rt. In the illustrated example, the electrode 143 is a pixel electrode formed for each pixel G. In this case, in the driving structure 111U, a switching element (not shown) connected to a wiring (not shown) is provided corresponding to the pixel, and an electrode 143 is connected to each switching element.

On the other hand, on the inner surface of the substrate 112 (the surface facing the substrate 111), a colored layer 151 in which a coloring material such as a dye or a pigment is dispersed in a resin base material such as a photopolymer (transparent resin), an acrylic resin, or the like. Protective film 152 made of a transparent insulating material, and electrode 1 made of a transparent conductor such as ITO
53, an alignment film 154 made of polyimide resin or the like is sequentially laminated.

In the liquid crystal display 100, the illumination light emitted from the illumination device 120 is transmitted through the polarizing plate 11.
5 is passed through the liquid crystal 114 in the light transmission region, subjected to predetermined light modulation, and then subjected to absorption / transmission action according to the polarization state by the polarizing plate 116. The predetermined transmissive display becomes visible on the viewing side.

In addition, when the lighting device 120 is not turned on, external light incident from the viewing side is changed to a predetermined deflection state by the polarizing plate 116 and is reflected by the reflection layer 143 in the light reflection region after passing through the liquid crystal 114. Then, after passing through the liquid crystal 114 again, the polarizing plate 116 is again subjected to absorption / transmission action according to the polarization state, whereby a predetermined reflective display can be visually recognized on the viewing side.

Although not limited to the liquid crystal display body shown in FIG. 6, the heating element is disposed not on the outer surface of the substrate but on the inner surface (the surface facing the other substrate) as in the above embodiments. It does not matter. When a heating element is formed on the inner surfaces of the substrates 111 and 112 in this way, the heating element needs to be insulated from wiring, electrodes, etc. by using or adding an appropriate interlayer insulating film. There is.

Moreover, in the said embodiment, although the several heat_generation | fever area | region comprised with a heat_generation | fever layer is provided in the range which is in each different distance from a light source, as shown in FIG. The distance between 218A and the light source 221 may be the same as or greater than the distance between the second heat generation region 218B and the light source 221. The first heat generation area 2
18A and the second heat generation area 218B not only overlap the light guide plate 222 in a plane but also overlap a display area of a liquid crystal display (not shown) in a plane.

In this case, since one part (main part) 218b1 of the second heat generation region 218B is disposed on the side opposite to the light source 221 with respect to the first heat generation region 218A, the one part 218b1 is the first heat generation. Although formed in a range farther from the light source 221 than the region 218A, the other part 218b2 of the second heat generation region 218B extends along the outer edge of the first heat generation region 218A.
Since the second portion 218b2 extends to the first side, the other portion 218b2 is at the same distance as the first heat generation region 21A or closer than the light source 221.

Even in the case as described above, the first heat generating region 21 is in a range close to the light source 211.
8A is disposed, and many portions (one portion 218b1) of the second heat generation region 218B are disposed in a range farther from the light source 211 than the first heat generation region 218A. It is possible to relax the temperature distribution due to the heat generated by 211.

FIG. 8 is a schematic perspective view illustrating an example of an electronic device on which the liquid crystal device 100 of the above embodiment is mounted. The electronic apparatus 1000 in the illustrated example is an in-vehicle car navigation system, and includes a main body 1010 and a display unit 1020 connected to the main body 1010. Body 101
0 is provided with an operation surface 1011 provided with operation buttons and the like, and an inlet 1012 for a recording medium such as a DVD. Inside the display unit 1020 is the liquid crystal device 100 described above.
And the display by the liquid crystal device 100, that is, the display of the navigation image can be visually recognized on the display screen 1020a of the display unit 1020.

In addition, the liquid crystal device and the electronic apparatus of the present invention are not limited to the above illustrated examples,
Of course, various modifications can be made without departing from the scope of the present invention.

For example, although the said embodiment demonstrated as what comprises the liquid crystal display device using a liquid crystal as a liquid crystal, you may comprise the liquid crystal display body using other liquid crystals, such as an electrophoretic display body.

In addition, each of the illuminating devices of the above embodiments constitutes a sidelight type (edge light type) backlight having a light source disposed opposite to the end face of the light guide plate. It may be a direct type backlight having a light source arranged in, or
Instead of the backlight, it may be a front light.

Further, each of the above heating elements includes a heating layer formed on the liquid crystal display, but may be configured as a heater unit formed separately from the liquid crystal display.

Moreover, although said heat generating body is arrange | positioned between a liquid crystal display body and an illuminating device, you may arrange | position at the visual recognition side of a liquid crystal display body.

The schematic longitudinal cross-sectional view (a) which shows the whole structure of embodiment, and the schematic plan view (b) which shows the planar structure of an illuminating device and a heat generating body. The schematic plan view which shows the planar structure of the illuminating device and heat generating body of different embodiment. Furthermore, the schematic plan view which shows the planar structure of the illuminating device of another embodiment, and a heat generating body. Furthermore, the schematic plan view which shows the planar structure of the illuminating device of another embodiment, and a heat generating body. The schematic block diagram which shows the structure of the heat generating body of embodiment. The expanded partial longitudinal cross-sectional view which shows the structural example of a liquid crystal display body. The schematic plan view which shows the structural example of a different heat generating body typically. FIG. 6 is a schematic perspective view of an electronic device equipped with a liquid crystal device.

Explanation of symbols

DESCRIPTION OF SYMBOLS 100 ... Liquid crystal device, 110 ... Liquid crystal display body, 111, 112 ... Substrate, 113 ... Sealing material, 1
14 ... Liquid crystal (liquid crystal), 115, 116 ... Polarizing plate, 117 ... Wiring substrate, 118 ... Heating element, 1
18A, 118B ... heating layer (heating zone), 119A, 119B ... terminal portion, 120 ... lighting device, 121 ... light source, 122 ... light guide plate, 122a ... light incident surface, 122b ... light emitting surface, 122
c ... back surface, 123 ... reflector, 127 ... wiring board, A ... display area, 1000 ... electronic device

Claims (11)

In a liquid crystal device comprising a liquid crystal display configured to be able to control the optical characteristics of the liquid crystal, and an illumination device that illuminates the liquid crystal display,
A heating element for heating the liquid crystal;
The illumination device includes a light guide plate that overlaps the liquid crystal display body in a plane, and a light source that emits light introduced into the light guide plate,
The heating element is provided corresponding to a temperature distribution resulting from heating of the liquid crystal display by the lighting device, and has a plurality of heating regions configured to function independently of each other. . The liquid crystal device according to claim 1, wherein the plurality of heat generating regions are formed separately from each other. The heating element is configured to heat the liquid crystal by a resistance heating method, and when applied to the same voltage or the same current, the heat generation density of the heat generation region arranged in a range relatively close to the light source is 3. The liquid crystal device according to claim 1, wherein the heat generation density of the heat generation region disposed in a relatively small range and relatively far from the light source is relatively large. The heat generating unit further includes a heat generation control unit capable of independently controlling a plurality of the heat generation regions in the heat generating body, and the heat generation region disposed in a range relatively close to the light source generates relatively low heat generation by the heat generation control unit. 4. The heat generation area having a density and disposed in a range relatively far from the light source is controlled so as to have a relatively high heat generation density. The liquid crystal device described. In a liquid crystal device comprising a liquid crystal display configured to be able to control the optical characteristics of the liquid crystal, and an illumination device that illuminates the liquid crystal display,
A heating element for heating the liquid crystal;
The lighting device includes a light guide plate that overlaps the liquid crystal display body in a plane, and a light source that emits light introduced into the light guide plate,
The heating element is provided corresponding to a temperature distribution resulting from heating of the liquid crystal display by the illumination device, and has a plurality of heating regions configured to generate different heating densities. apparatus. The first heat generation region disposed on the light source side, and the second heat generation region including one portion disposed on the opposite side of the first heat generation region from the light source,
The other part of the second heat generation region extends from the one part to the light source side along an outer edge of the first heat generation region. The liquid crystal device described. The heat generation area having a relatively low heat generation density disposed in a range relatively close to the light source, and the heat generation area having a relatively high heat generation density disposed in a range relatively far from the light source. The liquid crystal device according to claim 5. The heat generating region is configured by a heat generating layer disposed in a planar region where at least control of the liquid crystal display body is performed, and the heat generating layer is disposed between the liquid crystal and the lighting device. The liquid crystal device according to claim 1. The change width of the distance to the light source in the arrangement range of the heat generation area relatively close to the light source is smaller than the change width of the arrangement range of the heat generation area relatively far from the light source. The liquid crystal device according to any one of 1 to 8. The plurality of heat generating regions have a planar range separated along an isothermal region of a temperature distribution resulting from heating of the liquid crystal display by the lighting device. The liquid crystal device according to item. An electronic apparatus comprising the liquid crystal device according to claim 1.

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