JP5083798B2 - Liquid crystal display - Google Patents

Description

The present invention relates to a liquid crystal display equipment, about the particular high-speed driving is possible liquid crystal display equipment.

  The liquid crystal panel has a configuration in which liquid crystal is sealed between a pair of opposing substrates, and performs display by controlling the alignment state of the liquid crystal. For controlling the alignment state of the liquid crystal, a method of applying an electric field to the liquid crystal is known.

JP 2004-139018 A

  In driving a liquid crystal panel, it is necessary to consider the time from when an electric field is applied to the liquid crystal until it changes to a predetermined alignment state, and conversely, the time from when the application of the electric field is stopped until it changes to the original alignment state, etc. is there.

An object of the present invention is to provide a liquid crystal display equipment capable of high-speed driving to reduce the time.

The liquid crystal display device according to the present invention includes a pair of substrates each having a support substrate, a liquid crystal sealed between the pair of substrates, and between the support substrate of one of the pair of substrates and the liquid crystal. And a temperature sensor formed on one of the pair of substrates and disposed closer to the liquid crystal side than the support substrate of the formed substrate. The thermal insulating layer is higher in thermal insulation than the support substrate of the substrate on which the thermal insulating layer is formed, and the heater is on the liquid crystal side with respect to the thermal insulating layer. And is configured to be able to hold the liquid crystal at a temperature higher than the ambient temperature , and another thermal insulation is provided between the liquid crystal and a support substrate of a substrate different from the substrate on which the thermal insulating layer is formed. And the temperature sensor is formed, The insulating layer is higher in thermal insulation than the support substrate of the substrate on which the other heat insulating layer is formed, and the temperature sensor is disposed on the liquid crystal side with respect to the other heat insulating layer. Yes .

  The temperature higher than the ambient temperature is preferably 40 ° C. or higher.

  Further, it is preferable that a temperature control / on mode for driving the liquid crystal panel can be executed while temperature holding control for holding a temperature higher than the ambient temperature is executed.

  Further, it is preferable that the temperature control / on mode and the temperature control / off mode for driving the liquid crystal panel without executing the temperature holding control can be selectively executed.

  In addition, it is preferable that an interposed component disposed in contact with the liquid crystal panel is further provided, and the interposed component includes a material having higher thermal insulation than a support substrate with which the interposed component contacts.

  The liquid crystal display device is preferably a color liquid crystal display device using a field sequential method.

  The liquid crystal panel is preferably an OCB mode liquid crystal panel.

  Further, it is preferable to drive the liquid crystal panel at a speed twice or more with respect to the field frequency.

  Moreover, it is preferable that the heater is configured using a translucent film.

  Further, it is preferable that the liquid crystal panel further includes a light-shielding film opened corresponding to the pixel, and the heater is configured using the light-shielding film.

Moreover, it is preferable that the support substrate of each of a pair of said board | substrates is a glass substrate, and the said heat insulating layer is a resin layer.

  With the above configuration, the response speed of the liquid crystal is increased, so that high-speed driving is possible.

  Embodiments according to the present invention will be described below in detail with reference to the drawings.

  FIG. 1 shows an outline of the configuration of a liquid crystal display device 1 according to the embodiment, and FIG. 2 shows a cross-sectional view of an example of a liquid crystal panel 10 of the liquid crystal display device 1. As shown in FIG. 1, the liquid crystal display device 1 includes a liquid crystal panel 10, a backlight unit 12, intervening components 14, a driving device 16, an input device 18, and a temperature controller 20. . The backlight unit is also referred to as a backlight module, and is hereinafter abbreviated as a backlight.

  As will be described later, the liquid crystal panel 10 includes an array substrate 100, a counter substrate 200 disposed to face the array substrate 100, and a liquid crystal 300 sealed between the pair of substrates 100 and 200. Yes.

  Here, the case where the liquid crystal panel 10 is in a TN (Twisted Nematic) mode is illustrated, but instead of the liquid crystal panel 10, an OCB (Optically Compensated Bend) mode, a VA (Vertical Alignment) mode, and an IPS (In-Plane Switching) mode are illustrated. The liquid crystal display device 1 can also be configured by applying a liquid crystal panel of various modes such as FFS (Fringe Field Switching) mode. Further, although the case where the liquid crystal panel 10 is a transmissive type is illustrated, the liquid crystal display device 1 can be configured by applying a reflective or transflective liquid crystal panel instead of the liquid crystal panel 10.

  The liquid crystal panel 10 further includes a heater 206 and a temperature sensor 108.

  The backlight 12 includes a light source and is configured to emit white light, for example, and is arranged so that the array substrate 100 is irradiated with the light, that is, the backlight light. That is, the backlight 12 is arranged next to the liquid crystal panel 10 with the backlight light emission surface facing the array substrate 100.

  The interposed component 14 is interposed between the liquid crystal panel 10 and the backlight 12 and is in contact with both 10 and 12. The intervening component 14 is a component for thermally insulating the liquid crystal panel 10 and the backlight 12. For example, the intervening component 14 is more than the portion of the liquid crystal panel 10 where the intervening component 14 is in contact, for example, the support substrate 102 of the array substrate 100. It is configured to include a material having high thermal insulation (in other words, a material having low thermal conductivity), for example, an acrylic resin. In the drawing, the intervening component 14 is illustrated in a simplified manner, but is not limited to the illustrated shape.

  The driving device 16 is configured to receive the input image signal S and drive the liquid crystal panel 10 and the backlight 12 based on the signal S, and includes a signal processing circuit, a power supply circuit, and other various circuits necessary for the driving. It is configured.

  The input device 18 is a man-machine interface for an operator to input an instruction to the liquid crystal display device 1, converts the instruction input by the operator into an electric signal, an optical signal, etc., and transmits the electric signal to the driving device 16. It is configured as follows. The input device 18 includes, for example, operation buttons provided on the main body of the liquid crystal display device 1 and circuits associated therewith. Further, the input device 18 may be constituted by a remote control device (so-called remote controller), a keyboard, or the like.

  The temperature controller 20 is connected to the temperature sensor 108 and the heater 206, and is configured to be able to control the heater 206 in accordance with the temperature detected by the temperature sensor 108. The temperature controller 20 includes, for example, a power supply circuit for the heater 206 and an arithmetic device (so-called microprocessor), and is configured to control the output of the power supply circuit by executing a control program by the arithmetic device. . Instead of executing the control program, the temperature controller 20 may be configured using, for example, an electric circuit. The temperature controller 20 is configured to be able to transmit and receive signals and the like to and from the driving device 16 and is connected to the driving device 16.

  Next, the liquid crystal panel 10 will be further described with reference to FIG.

  The array substrate 100 includes a support substrate 102, a thermal insulating layer 104, a semiconductor layer 106, a temperature sensor 108, a gate insulating film 110, a gate electrode 112, an auxiliary capacitance electrode 114, an interlayer insulating film 116, A source electrode 118, a drain electrode 120, a planarizing film 122, and a pixel electrode 124 are included.

  In the array substrate 100, a pixel TFT (Thin Film Transistor) 152 including the semiconductor layer 106, the gate insulating film 110, and the gate electrode 112, or further including the source electrode 118 and the drain electrode 120 is configured. The auxiliary capacitor 154 includes the gate insulating film 110 and the auxiliary capacitor electrode 114.

  The support substrate 102 is made of translucent glass, for example.

  The heat insulating layer 104 is made of a light-transmitting material such as a transparent acrylic resin, which is a material having a higher heat insulating property than the supporting substrate 102 (in other words, a material having a low thermal conductivity). Are disposed on the entire surface facing the counter substrate 200. As a result, in the array substrate 100, the support substrate 102 and the portion closer to the counter substrate 200 than the thermal insulating layer 104 are thermally insulated. The thickness of the heat insulating layer 104 is, for example, 100 μm or more.

  The semiconductor layer 106 is made of, for example, amorphous silicon, polysilicon, or the like, and is disposed on the heat insulating layer 104. The semiconductor layer 106 includes regions that constitute the source and drain of the pixel TFT 152.

  The temperature sensor 108 is made of, for example, a film made of the same material as that of the semiconductor layer 106 and is disposed on the heat insulating layer 104, that is, in the same layer (same layer) as the semiconductor layer 106. The temperature sensor 108 is disposed at a position facing the liquid crystal 300, and is disposed, for example, just outside the display area of the liquid crystal panel 10. A plurality of temperature sensors 108 may be scattered in the array substrate 100.

  Although not shown in detail, the temperature sensor 108 is connected to the temperature controller 20, and the temperature controller 20 detects the temperature of the temperature sensor 108 using the temperature dependence of the resistance value of the temperature sensor 108. For example, since the value of the current flowing through the temperature sensor 108 corresponding to the temperature dependence of the resistance value has temperature dependence, the temperature controller 20 can know the temperature by measuring the current value. It is. In this case, the value of the current flowing through the temperature sensor 108 can be grasped as the temperature detected by the temperature sensor 108. Instead of the temperature sensor 108, for example, a temperature sensor can be configured by utilizing the temperature dependence of characteristics such as a diode.

  The gate insulating film 110 is made of, for example, silicon oxide, and is disposed on the thermal insulating layer 104 so as to cover the semiconductor layer 106 and the temperature sensor 108. The gate electrode 112 is made of, for example, metal, amorphous silicon, polysilicon, or the like, and is disposed on the gate insulating film 110 so as to face the semiconductor layer 106.

  The auxiliary capacitance electrode 114 is made of, for example, the same material as the gate electrode 112, and is disposed on the gate insulating film 110 so as to face the semiconductor layer 106. The auxiliary capacitance electrode 114 faces the semiconductor layer 106 on the drain side of the semiconductor layer 106, whereby the auxiliary capacitance 154 is connected to the drain of the pixel TFT 152.

  The auxiliary capacitor 154 includes a pixel electrode 124 and a common electrode 214 that are opposed to each other with the liquid crystal 300 interposed therebetween, and has a capacity that is at least twice the so-called liquid crystal capacity. Such a capacitance can be achieved by adjusting the facing area between the semiconductor layer 106 and the auxiliary capacitance electrode 114, the thickness of the gate insulating film 110, the material of the gate insulating film, and the like.

  The interlayer insulating film 116 is made of, for example, silicon oxide, is disposed on the gate insulating film 110 so as to cover the gate electrode 112 and the auxiliary capacitance electrode 114, and is also disposed above the temperature sensor 108. A contact hole is provided through the interlayer insulating film 116 and the gate insulating film 110, and the contact hole is provided in a position corresponding to the source and drain of the pixel TFT 152 in the semiconductor layer 106.

  The source electrode 118 is made of, for example, metal, amorphous silicon, polysilicon, or the like, is disposed on the interlayer insulating film 116, and is in contact with the source of the semiconductor layer 106 through the contact hole. The drain electrode 120 is made of, for example, the same material as the source electrode 118, is disposed on the interlayer insulating film 116, and is in contact with the drain of the semiconductor layer 106 through the contact hole. Note that the source and the drain can be called in the opposite manner.

  The planarizing film 122 is made of, for example, silicon oxide, is disposed on the interlayer insulating film 116 so as to cover the source electrode 118 and the drain electrode 120, and is also disposed above the temperature sensor 108. A contact hole is provided on the drain electrode 120 through the planarizing film 122.

  The pixel electrode 124 is made of a light-transmitting conductive material such as ITO (Indium Tin Oxide), and is disposed on the planarizing film 122 and is in contact with the drain electrode 120 through the contact hole. The pixel electrode 124 is provided at a position corresponding to the pixel of the liquid crystal panel 10.

  With the above configuration, in the liquid crystal panel 10, the source electrode 118 and the pixel electrode 124 are electrically (circuitically) connected via the pixel TFT 152 and the drain electrode 120, and the pixel electrode 124 and the auxiliary capacitor 154 are connected to the drain. It is electrically (circuit-wise) connected through the electrode 120. Therefore, the potential applied to the source electrode 118 is applied to the pixel electrode 124 and the auxiliary capacitor 154 via the pixel TFT 152 and the drain electrode 120.

  Note that another layer such as a silicon oxide layer may be provided between the heat insulating layer 104 and the support substrate 102, or on the opposite side, that is, between the heat insulating layer 104 and the semiconductor layer 106 or the like. It is the same.

  The counter substrate 200 includes a support substrate 202, a heat insulating layer 204, a heater 206, a light shielding film 208, a color filter 210, a planarization film 212, and a common electrode 214. .

  The support substrate 202 is made of translucent glass, for example.

  The heat insulating layer 204 is a material having a higher heat insulating property than the support substrate 202 and is made of a light-transmitting material, for example, a transparent acrylic resin, and is entirely formed on the surface of the support substrate 202 facing the array substrate 100. Is arranged. The thickness of the heat insulating layer 204 is, for example, 100 μm or more.

  The heater 206 is composed of a film of a translucent material such as ITO, for example, and is disposed on the entire surface of the heat insulating layer 204. For example, although not shown in detail, the heater 206 is connected to the temperature controller 20 and supplied with electric power from the temperature controller 20 to generate Joule heat due to electric resistance.

  The light-shielding film 208 is composed of, for example, a laminated film of chromium and chromium oxide, and is disposed on the heater 206. The light-shielding film 208 has an opening at a position facing the pixel electrode 124, and the outline, shape, and the like of the pixel are defined by the opening. The light shielding film 208 has a role of preventing light leakage between pixels and improving display quality.

  The color filter 210 is made of, for example, dyed resin, and is disposed on the heater 206 so as to overlap the opening of the light-shielding film 208. As a result, the light emitted toward the support substrate 202 via the color filter 210 is colored. The color of the color filter 210 is set according to the opening to be arranged, that is, the pixel.

  The planarization film 212 is made of, for example, silicon oxide, and is disposed on the entire surface of the light shielding film 208 and the color filter 210. Note that the planarization film 212 may be omitted.

  The common electrode 214 is made of a light-transmitting conductive material such as ITO, and is disposed on the entire surface of the planarizing film 212.

  Note that another layer such as a silicon oxide layer may be provided between the heat insulating layer 204 and the support substrate 202, or on the opposite side, that is, between the heat insulating layer 204 and the color filter 210 or the like. It is the same.

  The counter substrate 200 is disposed on the pixel electrode 124 side of the array substrate 100, in other words, on the opposite side of the support substrate 102, and the common electrode 214 faces the array substrate 100 side, in other words, the support substrate 202 is arrayed. It is arranged away from the substrate 100.

  The liquid crystal 300 is sealed between the array substrate 100 and the counter substrate 200, and here also exists between the heater 206 and the temperature sensor 108.

  The array substrate 100 and the counter substrate 200 can be manufactured by using various film forming techniques and patterning techniques, and the liquid crystal 300 can be sealed by various sealing techniques.

  With the above configuration, the heater 206 generates heat by power feeding, and the temperature of the liquid crystal 300 and the temperature sensor 108 rises due to this heat generation. Further, by stopping the power supply to the heater 206 after the temperature rises, the temperatures of the liquid crystal 300 and the temperature sensor 108 are lowered.

  FIG. 3 shows a graph for explaining the temperature dependence of the response time of the liquid crystal, that is, the response speed. FIG. 3 is a graph for an OCB mode liquid crystal. Response time at the time of rise (time from application of an electric field to change to a predetermined alignment state) Tr and response time at the time of fall (stop of electric field application) Tf) and the total time Tr + Tf are shown in the figure. As can be seen from FIG. 3, the higher the temperature of the liquid crystal, the shorter the response time, that is, the faster the response speed. FIG. 3 is a graph for the OCB mode, but the same tendency is observed for the TN mode and the like.

  FIG. 4 is a schematic diagram for explaining the operation of the liquid crystal display device 1. The operation of the liquid crystal display device 1 will be described with reference to FIGS.

  First, the liquid crystal display device 1 is configured to selectively execute a temperature control / on mode and a temperature control / off mode. Here, the temperature control / on mode is a mode in which the liquid crystal panel 10 is driven while performing temperature holding control for holding the temperature detected by the temperature sensor 108 within the predetermined range TT. The temperature control / off mode is a mode in which the liquid crystal panel 10 is driven without executing the temperature holding control. The temperature holding control can be executed by the temperature controller 20 controlling the heater 206 according to the temperature detected by the temperature sensor 108. The liquid crystal panel 10 is driven by the driving device 16. In the figure, “temperature control / on mode” and “temperature control / off mode” are abbreviated as “on mode” and “off mode”.

  The predetermined range TT is set higher than the temperature detected by the temperature sensor 108 when the liquid crystal panel 10 is driven with the heater 206 turned off, that is, in the temperature control / off mode. This corresponds to about 40 ° C. or higher, which is higher than the temperature around the device 1 or the liquid crystal panel 10. In addition, the predetermined range TT is set to a temperature range in phase with the temperature control / off mode, that is, a range in which the liquid crystal 300 does not undergo phase transition in the temperature control / off mode. The correspondence between the detected temperature and the temperature of the liquid crystal 300 can be known in advance from calculation based on the structure of the liquid crystal panel 1 or through experiments.

  When the operator operates the input device 18 to issue an instruction to switch to the temperature control / on mode while the liquid crystal panel 10 is being driven, that is, during display, the instruction is transmitted to the temperature controller 20 via the driving device 16. . Receiving the instruction, the temperature controller 20 starts supplying power to the heater 206 (turns on the heater 206) and monitors the temperature detected by the temperature sensor 108 (see time t1). The liquid crystal 300 is heated by the heater 206, and the temperature detected by the temperature sensor 108 is increased accordingly.

  When the temperature controller 20 detects that the temperature detected by the temperature sensor 108 has reached the lower limit temperature of the predetermined range TT (see time t2), the temperature controller 20 thereafter causes the heater 206 to maintain the detected temperature within the predetermined range TT. To control. The temperature holding control can be performed, for example, by appropriately switching the heater 206 on and off, and by changing the amount of power supplied to the heater 206, for example.

  Thereafter, when the operator operates the input device 18 to give an instruction to switch to the temperature control / off mode, the instruction is transmitted to the temperature controller 20 via the drive device 16. The temperature controller 20 that has received the instruction stops power supply to the heater 206, that is, turns off the heater 206 (see time t3). Thereafter, the temperature of the liquid crystal 300 decreases and the temperature detected by the temperature sensor 108 also decreases.

  In FIG. 4, the time t2 when the detected temperature reaches the lower limit temperature of the predetermined range TT is the start time of the temperature control / on mode, but the period from the time t1 when the heater 206 is turned on to the time t2 is also detected. The time t1 may be regarded as the start time of the temperature control / on mode, taking as an operation period necessary for maintaining the temperature within the predetermined range TT. In FIG. 4, the time t4 when the detected temperature falls to the lower limit temperature of the predetermined range TT is illustrated as the end point of the temperature control / on mode, but the temperature control / on is performed at the time t3 when the heater 206 is turned off. -It may be the end point of the mode.

  Instead of completely turning off the heater 206 at time t3, the power supplied to the heater 206 may be gradually reduced to gradually cool (slowly cool) the liquid crystal panel 10 (one point in FIG. 4). (See the characteristic line for chain lines.)

  According to the temperature control / on mode, the response speed of the liquid crystal is increased, so that higher speed driving is possible. For example, it becomes possible to drive at a speed twice or more with respect to the field frequency. As a result, it is possible to improve the display quality of, for example, a fast image, in other words, an image having a large change between consecutive fields.

  Here, unlike the configuration of FIG. 1, the liquid crystal is transmitted so that an instruction to switch between temperature control / on mode and temperature control / off mode by the operator is transmitted to the temperature controller 20 without passing through the driving device 16. The display device 1 may be configured.

  Further, when the driving device 16 analyzes the input image signal S and determines that the necessity for high-speed driving is high, for example, in the case of the above-mentioned fast image, the temperature control / on mode is switched, and there is a necessity for high-speed driving. If it is determined that the temperature is low, the liquid crystal display device 1 may be configured to switch to the temperature control / off mode.

  Further, as shown in the schematic diagram of FIG. 5, the liquid crystal display device 1 may be configured to always use the temperature control / on mode. For example, if the power source of the liquid crystal display device 1 is turned on (see time s1), the heater 206 is turned on in conjunction with it (see time s2), and the temperature detected by the temperature sensor 108 reaches a predetermined range TT. For example, the liquid crystal display device 1 may be configured to start display (see time s3).

  Since the heater 206 does not consume power in the temperature control / off mode, the temperature control / on mode is always used according to the selective execution of the temperature control / on mode and the temperature control / off mode. It is possible to suppress power consumption compared to.

  In the above configuration, since the auxiliary capacitor 154 has a capacity more than twice the liquid crystal capacity, even if the dielectric constant of the liquid crystal 300 is lowered in the temperature control / off mode, the liquid crystal capacity is reduced. Display operation can be performed.

  In the above configuration, the heater 206 is disposed closer to the liquid crystal 300 in the counter substrate 200 than in the support substrate 202. For this reason, compared with the case where the heater 206 is disposed on the surface forming the outer surface of the liquid crystal panel 10 in the support substrate 202, the power supplied to the heater 206 can be reduced by shortening the heat transfer path, and the liquid crystal The temperature rise of 300 can be accelerated. For example, when the thickness of the support substrates 102 and 202 is about 100 times the layer thickness of the liquid crystal 300, the amount of heat (calories) required to raise the temperature of the liquid crystal 300 by 10 ° C. and the electric power (watts) associated therewith are, for example, It can be reduced to about 0.1%.

  The temperature sensor 108 is disposed closer to the liquid crystal 300 than the support substrate 102 in the array substrate 100. For this reason, compared with the case where the temperature sensor 108 is disposed on the surface that forms the outer surface of the liquid crystal panel 10 in the support substrate 202, a temperature closer to the temperature of the liquid crystal 300 can be detected by shortening the heat transfer path. In addition, the followability of temperature detection with respect to the temperature change of the liquid crystal 300 is improved.

  Further, the heat insulating layer 104 is disposed on the liquid crystal 300 side with respect to the support substrate 102, and the heat insulating layer 204 is disposed on the liquid crystal 300 side with respect to the support substrate 202. Further, the heater 206 is disposed on the same side as the liquid crystal 300 (with respect to the thermal insulating layer 104), and is disposed on the same side as the liquid crystal 300 with respect to the thermal insulating layer 204. That is, the heater 206 and the liquid crystal 300 are disposed between the heat insulating layers 104 and 204 having higher heat insulating properties than the support substrates 102 and 202. For this reason, it is possible to reduce the escape of the heat generated by the heater 206 through the support substrates 202 and 102, and a larger amount of heat is used for heating the liquid crystal 300. Therefore, it is possible to improve the reduction in power for the heater 206 and the rapid increase in temperature. In addition, although the improvement effect of electric power reduction and a temperature rise quickness is acquired only in any one of the heat insulation layers 104 and 204, it becomes larger by providing both the heat insulation layers 104 and 204. FIG.

  The temperature sensor 108 is also disposed on the same side as the liquid crystal 300 with respect to the heat insulating layer 104 and the heat insulating layer 204. For this reason, compared with the case where the temperature sensor 108 and the liquid crystal 300 are arrange | positioned on the separate side with respect to the heat insulating layer 104, the change of the temperature which the temperature sensor 108 detects is large. Therefore, temperature detection can be performed more accurately, and as a result, the temperature control can be performed more accurately.

  In addition, the liquid crystal panel 10 and the backlight 12 are adjacent to each other via the intervening component 14, and the intervening component 14 has higher thermal insulation than the contact portion with the liquid crystal panel 10. It is possible to reduce the escape to the backlight 12 through the lamp. Therefore, it is possible to further reduce the power for the heater 206 and speed up the temperature rise. The intervening component 14 can be applied between the backlight 12 and other components arranged next to the liquid crystal panel 10. For example, the interposed component 14 can be applied to a component that supports the liquid crystal panel 10. .

  In addition, although the case where the heater 206 is configured using a film of a light-transmitting material has been illustrated, in this case, the film can be provided on the entire surface of the counter substrate 200 and there is no need for patterning. On the other hand, the heater 206 can be formed in the same plane pattern as the light-shielding film 208, for example. In this case, the material of the heater 206 does not need to be light-transmitting. Here, by supplying power to the light-shielding film 208, the liquid crystal 300 can be heated using Joule heat generated by the light-shielding film 208, that is, the light-shielding film 208 can also be used as a heater. is there. In this case, since it is not necessary to provide the heater 206 separately, the structure of the liquid crystal panel 10 can be simplified. Similarly, the common electrode 214 formed of a film of a light-transmitting material can be used as a heater, and in this case, the configuration of the liquid crystal panel 10 can be simplified.

  Further, the temperature sensor 108 can be made of a material different from that of the semiconductor layer 106. On the other hand, when the temperature sensor 108 is made of the same material as the semiconductor layer 106 as described above, it can be formed simultaneously (in parallel) with the semiconductor layer 106, and the number of manufacturing steps can be reduced.

  Further, the temperature sensor 108 may be disposed on the same layer as the gate electrode 112, that is, on the gate insulating film 110. In this case, the temperature sensor 108 can be formed of the same material as the gate electrode 112 or the auxiliary capacitance electrode 114. It is. Similarly, the temperature sensor 108 can be arranged in the same layer as the source electrode 118 and the like, and can be formed of the same material as the source electrode 118 and the like. The temperature sensor 108 can detect the temperature of the liquid crystal 300 more accurately as it is closer to the liquid crystal 300.

  The heater 206 may be provided on the array substrate 100 or may be provided on both the array substrate 100 and the counter substrate 200. Similarly, the temperature sensor 108 may be provided on the counter substrate 200, or may be provided on both the array substrate 100 and the counter substrate 200.

  In the above description, the configuration using the heater 206 is illustrated. However, by effectively using the heat generated during the operation of the liquid crystal panel 10 or the like, the liquid crystal 300 can be kept at a temperature higher than the ambient temperature even when the heater 206 is not provided. It is possible to raise it. In this case, the heat insulating layers 104 and 204 contribute to the temperature rise and heat retention of the liquid crystal 300.

  Next, a case where color display by the field sequential method is performed by applying the liquid crystal display device 1 will be described.

  FIG. 6 is a schematic diagram for explaining the field sequential method. The field sequential method is a color display method in which, for example, red, green, and blue images are mixed and displayed by sequentially switching and displaying each image in a time division manner. For example, a period (time) for displaying a red image includes a TFT scan period, a liquid crystal response period, and a backlight (BL) lighting period. The TFT scan period is a period in which the pixel TFT of the liquid crystal panel is scanned and a corresponding potential in a red image is applied to each pixel electrode. The liquid crystal response time is a period in which the liquid crystal responds by applying a potential to the pixel electrode. The BL lighting period is a period in which a red backlight (BL) light is turned on after the liquid crystal response to actually display a red image. The same applies to the period for displaying the green image and the blue image.

  In the field sequential method, images of each color are switched and displayed within one field period (= 1/60 seconds), so the period for displaying the images of each color is 1/180 seconds or less, that is, about 5.6 mm. Less than a second. Here, since the length of the TFT scanning period is fixed by the number of scanning lines of the liquid crystal panel 10, the shortening of the BL lighting period leads to the reduction of the luminance, so that the liquid crystal response period is shortened, that is, the liquid crystal has a high speed. Driving is required.

  Since the liquid crystal display device 1 can be driven at high speed by temperature control / on mode, it can be easily applied to the field sequential method. In the case of performing color display by the field sequential method in the liquid crystal display device 1, the backlight 12 is configured to be able to sequentially emit red, green, and blue backlights in a time division manner in the above example. For example, red, green, and blue light sources are provided, which are sequentially switched on. In the field sequential method, since a color filter is unnecessary, the liquid crystal panel 10 in which the color filter 210 is removed from the above configuration as shown in the cross-sectional view of FIG. 7 is applicable.

  In general, in the field sequential method, an OCB mode liquid crystal panel suitable for high-speed driving is used. However, according to the liquid crystal display device 1, the field sequential method can be performed not only in the OCB mode but also in the TN mode by high-speed driving using the temperature control / on mode. For example, the liquid crystal panel 10 in the OCB mode, the TN mode, and other various modes can be applied by setting the predetermined range TT for the detected temperature to a temperature range in which the liquid crystal 300 is about 40 ° C. or higher.

  In addition, when performing color display by the field sequential method with the liquid crystal display device 1, the display order of each color image, the color of each divided image, and the like are not limited to the above example.

  In the field sequential method, there is a case in which a color break (or color break-up) occurs in which the images of the respective colors are separated and visually recognized without being mixed. In this color break, by switching the image of each color at a higher speed than the above-mentioned about 5.6 milliseconds, for example, the image of each color is switched in a time of 2.8 milliseconds or less, which is twice or more the field frequency. Can be suppressed.

  Here, referring to the graph of FIG. 3, it can be seen that in the OCB mode, when the temperature of the liquid crystal is about 25 ° C. or higher, the response time of 2.8 milliseconds or less can be realized. Further, it can be seen that when the temperature of the liquid crystal is about 40 ° C. or higher, a stable response time with low temperature dependency can be realized with the response time of 2.8 milliseconds or less. Therefore, the color break can be suppressed by setting the predetermined range TT to a temperature range in which the liquid crystal 300 is about 25 ° C. or higher or a temperature range in which the liquid crystal 300 is about 40 ° C. or higher. The same tendency applies to the TN mode and the like.

1 is a configuration diagram of a liquid crystal display device according to an embodiment of the present invention. It is sectional drawing explaining the structure of the liquid crystal panel which concerns on embodiment of this invention. It is a graph explaining the temperature dependence of the response time of a liquid crystal. It is a schematic diagram explaining operation | movement of the liquid crystal display device which concerns on embodiment of this invention. It is a schematic diagram explaining other operation | movement of the liquid crystal display device which concerns on embodiment of this invention. It is a schematic diagram explaining a field sequential system. It is sectional drawing explaining the other structure of the liquid crystal panel which concerns on embodiment of this invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 Liquid crystal display device, 10 Liquid crystal panel, 14 Interposition components, 100 Array substrate, 102 Support substrate, 104 Thermal insulating layer, 108 Temperature sensor, 154 Auxiliary capacity, 200 Opposite substrate, 202 Support substrate, 204 Thermal insulating layer, 206 Heater, 208 light-shielding film, 214 common electrode, 300 liquid crystal.

Claims (11)

A pair of substrates each having a supporting substrate; a liquid crystal sealed between the pair of substrates; a thermal insulating layer formed between the supporting substrate of one of the pair of substrates and the liquid crystal; A liquid crystal panel including a heater and a temperature sensor formed on one of the pair of substrates and disposed on the liquid crystal side with respect to the support substrate of the formed substrate ;
The thermal insulation layer is higher in thermal insulation than the support substrate of the substrate on which the thermal insulation layer is formed,
The heater is disposed on the liquid crystal side with respect to the heat insulating layer,
The liquid crystal is configured to be held at a temperature higher than the ambient temperature ,
Another thermal insulating layer and the temperature sensor are formed between a support substrate of the substrate different from the substrate on which the thermal insulating layer is formed and the liquid crystal,
The another heat insulating layer is higher in heat insulation than the support substrate of the substrate on which the other heat insulating layer is formed,
The temperature sensor is disposed on the liquid crystal side with respect to the another heat insulating layer,
Liquid crystal display device. The liquid crystal display device according to claim 1,
The temperature higher than the ambient temperature is 40 ° C. or higher.
Liquid crystal display device.   A liquid crystal display device according to any one of claims 1 to 2,
  The temperature control / on mode for driving the liquid crystal panel while executing the temperature holding control for holding a temperature higher than the ambient temperature is configured to be executable.
  Liquid crystal display device.   The liquid crystal display device according to claim 3,
  The temperature control / on mode and the temperature control / off mode for driving the liquid crystal panel without executing the temperature holding control can be selectively executed.
  Liquid crystal display device.   A liquid crystal display device according to any one of claims 1 to 4,
  Further comprising an interposition component disposed in contact with the liquid crystal panel,
  The interposed component is configured to include a material having higher thermal insulation than the support substrate with which the interposed component contacts.
  Liquid crystal display device.   A liquid crystal display device according to any one of claims 1 to 5,
  The liquid crystal display device is a color liquid crystal display device by a field sequential method.
  Liquid crystal display device.   The liquid crystal display device according to claim 6,
  The liquid crystal panel is an OCB mode liquid crystal panel.
  Liquid crystal display device.   A liquid crystal display device according to any one of claims 1 to 7,
  Driving the liquid crystal panel at a speed at least twice the field frequency;
  Liquid crystal display device.   A liquid crystal display device according to any one of claims 1 to 8,
  The heater is configured using a translucent film,
  Liquid crystal display device.   A liquid crystal display device according to any one of claims 1 to 9,
  The liquid crystal panel further includes a light-shielding film opened corresponding to the pixel,
  The heater is configured using the light-shielding film,
  Liquid crystal display device.   A liquid crystal display device according to any one of claims 1 to 10,
  The support substrate of each of the pair of substrates is a glass substrate, and the thermally insulating layer is a resin layer.
  Liquid crystal display device.

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