JP2007309970A - Liquid crystal display and electronic equipment - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a liquid crystal display which can heat the liquid crystals depending on their temperature and also heat the liquid crystals evenly within the display screen, and provide an electronic device incorporating this liquid crystal display. <P>SOLUTION: This liquid crystal display 1 has glass substrates 11, 21 facing each other, liquid crystals 62 which fill them, a heater layer 41 heated by currents, and resistor elements 42 connected in series to the heater layer 41 and changing their resistance by temperature. When the temperature of the liquid crystals 62 is lower than predetermined, the resistance of the resistor elements 42 drops, and a current flows through the feeder 43, the resistor elements 42, the heater layer 41, and the GND electrode 44 to heat the heater layer 41. Thus, the liquid crystal 62 is heated to maintain quick responses even at a low temperature. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a liquid crystal display device having a function of heating liquid crystal, and an electronic apparatus including the liquid crystal display device.

  In recent years, a liquid crystal display device having features such as a small size, a light weight, a thin shape, and low power consumption is often used as a display body incorporated in various electronic devices such as a mobile phone. A liquid crystal display device generally includes a pair of substrates and a liquid crystal sealed between the substrates. This liquid crystal has a property that its characteristics change depending on the temperature, and the temperature dependence of the response speed is particularly large. Specifically, the response speed of the liquid crystal becomes slower as the temperature becomes lower, and becomes extremely slow particularly in an environment below freezing point. For this reason, the liquid crystal display device has a problem that, when the temperature becomes low, the image quality is deteriorated due to the decrease in the response speed of the liquid crystal, and the display quality is deteriorated.

  In order to avoid this problem, there is known a liquid crystal display device having a configuration in which a heater is attached to the outer surface of a substrate and the liquid crystal is heated by the heater at a low temperature. However, in this configuration, since the liquid crystal is heated from the outside of the substrate through the substrate, the heating efficiency is low, and it is difficult to heat the liquid crystal quickly.

  Therefore, a liquid crystal display device having a configuration in which a heater is attached to the opposite surface of the substrate (that is, the surface on which liquid crystal is sealed) and the heater is operated according to the temperature detected by a temperature sensor installed outside the substrate is patented. It is disclosed in Document 1. According to this liquid crystal display device, since the heat of the heater is transmitted to the liquid crystal without passing through the substrate, the above problem is temporarily solved.

JP 2005-122190 A

  However, since the liquid crystal display device operates the heater according to the outside air temperature, the heater does not necessarily operate in conjunction with the temperature of the liquid crystal. For this reason, for example, when a heat source is generated in the vicinity of the temperature sensor, the heater may not operate even when the temperature of the liquid crystal becomes low. Alternatively, even if the temperature of the liquid crystal is raised by the heater, the detection may be delayed and the liquid crystal may be overheated. Further, since the liquid crystal display device is heated by a single heater, there is a problem in that display unevenness occurs due to in-plane variation in the amount of heat generated by the heater.

  In view of such problems, an object of the present invention is to provide a liquid crystal display device capable of heating a liquid crystal according to the temperature of the liquid crystal and further capable of heating the liquid crystal to a uniform temperature in a plane. There is. Another object of the present invention is to provide an electronic device including the liquid crystal display device.

  In order to solve the above problems, a liquid crystal display device according to the present invention includes a pair of substrates disposed opposite to each other, a liquid crystal sealed between the pair of substrates, and an opposing surface of at least one of the substrates. A control unit having a heater layer, which is heated by flowing current, and a temperature sensor, which is arranged on the facing surface of at least one of the substrates, and is based on the temperature detected by the temperature sensor; And a control unit for passing a current through the heater layer.

  In the liquid crystal display device having such a configuration, the temperature sensor included in the control unit is disposed on the opposite surface of the substrate (the surface on the side where the liquid crystal is sealed). Is detected without delay, and the temperature reflecting the actual temperature of the liquid crystal is detected. A control part sends the electric current according to this detected temperature to a heater layer. Preferably, a control part sends an electric current through a heater layer, when detected temperature becomes below a predetermined value. Thereby, the heater layer is heated, and this heat is transmitted to the liquid crystal to heat the liquid crystal. Here, since the heater layer is disposed on the opposing surface of the substrate, the heat of the heater layer is efficiently transmitted to the liquid crystal, and the liquid crystal can be quickly heated. As described above, the liquid crystal display device having the above-described configuration can detect the temperature of the liquid crystal and can quickly heat the liquid crystal according to the temperature. According to the liquid crystal display device having such a configuration, a high-speed response can be realized regardless of the use environment, and a display quality equivalent to that in a normal temperature environment can be maintained even in a low temperature environment.

  Preferably, the liquid crystal display device includes a plurality of the control units, and the control units are arranged in a matrix on the opposing surface of the substrate.

  According to such a configuration, the temperatures of the liquid crystals at different locations can be detected simultaneously by the temperature sensors included in the control units arranged in a matrix. And each control part sends an electric current to a heater layer independently of another control part according to the detection temperature of the temperature sensor which the control part has, and a liquid crystal is heated. For this reason, even when the temperature of the liquid crystal varies within the plane of the substrate, it is possible to heat the heater layer while making the variation uniform. Therefore, display unevenness due to temperature variations in the substrate surface can be reduced. Here, in the liquid crystal display device, it is preferable that the heater layers are arranged in a matrix corresponding to the control unit on the opposing surface of the substrate.

  In the liquid crystal display device of the present invention, a pair of substrates arranged opposite to each other, a liquid crystal sealed between the pair of substrates, and an electric current arranged on at least one of the opposed surfaces of the substrate flow. A heater layer that is heated by, and a resistance element that is arranged in a state of being connected in series with the heater layer on the opposing surface of the substrate on which the heater layer is formed, and whose resistance value varies with temperature, And a resistance element that controls a current flowing through the heater layer in accordance with the resistance value.

  In the liquid crystal display device having such a configuration, since the resistance element is disposed on the opposite surface of the substrate, the temperature follows the change in the temperature of the liquid crystal without delay, and reflects the actual temperature of the liquid crystal. It has a resistance value. The resistance element controls the current flowing through the heater layer in accordance with the resistance value. More specifically, a current having a magnitude approximately inversely proportional to the sum of the resistance value of the resistance element and the resistance value of the heater layer flows through the resistance element and the heater layer. Therefore, an amount of current corresponding to the temperature of the liquid crystal flows through the heater layer. The heater layer is heated according to the current, and this heat is transmitted to the liquid crystal to heat the liquid crystal. Further, since the heater layer is disposed on the opposite surface of the substrate, the heat of the heater layer is efficiently transmitted to the liquid crystal, and the liquid crystal can be heated quickly. Thus, the liquid crystal display device having the above-described configuration can quickly heat the liquid crystal according to the temperature of the liquid crystal. According to the liquid crystal display device having such a configuration, a high-speed response can be realized regardless of the use environment, and good display quality can be maintained even in a low temperature environment.

  Here, it is preferable that the resistance element has a characteristic that the resistance value increases as the temperature rises. According to such a configuration, a larger current flows through the heater layer as the temperature of the liquid crystal is lower, so that the liquid crystal can be kept at a certain temperature or higher.

  The liquid crystal display device preferably includes a plurality of pixels, and the resistive element is disposed for each pixel. The liquid crystal display device preferably includes a plurality of pixels including a plurality of sub-pixels, and the resistive element is disposed for each sub-pixel.

  According to such a configuration, the resistance element arranged in each pixel or each subpixel has a resistance value corresponding to the temperature of the liquid crystal in each pixel or each subpixel. Each resistance element controls the current flowing through the heater layer independently of the resistance elements of other pixels or sub-pixels according to the resistance value. For this reason, each pixel or each sub-pixel is heated according to the temperature of the liquid crystal, and even when the temperature of the liquid crystal varies in the plane of the substrate, it is possible to heat while uniforming the variation. it can. Thereby, display unevenness due to temperature variations in the substrate surface can be reduced.

  Here, in the liquid crystal display device, the heater layer is preferably disposed for each pixel. When the pixel has a plurality of sub-pixels, it is preferable that the resistive element is arranged for each sub-pixel.

  In the liquid crystal display device of the present invention, a pair of substrates arranged opposite to each other, a liquid crystal sealed between the pair of substrates, and an electric current arranged on at least one of the opposed surfaces of the substrate flow. A heater layer heated by the heater layer, a resistance element having a resistance value that varies with temperature, disposed on the opposing surface of the substrate on which the heater layer is formed, and an opposing surface of the substrate on which the heater layer is formed And a switching element that controls a current flowing through the heater layer in accordance with the resistance value of the resistance element.

  In the liquid crystal display device having such a configuration, since the resistance element is disposed on the opposite surface of the substrate, the temperature follows the change in the temperature of the liquid crystal without delay, and reflects the actual temperature of the liquid crystal. It has a resistance value. The switching element is switched on and off according to the resistance value of the resistance element, that is, according to the temperature of the liquid crystal. When the switching element is turned on, a current flows through the heater layer and the liquid crystal is heated. The heater layer is heated according to the current, and this heat is transmitted to the liquid crystal to heat the liquid crystal. Further, since the heater layer is disposed on the opposite surface of the substrate, the heat of the heater layer is efficiently transmitted to the liquid crystal, and the liquid crystal can be heated quickly. Thus, the liquid crystal display device having the above-described configuration can quickly heat the liquid crystal according to the temperature of the liquid crystal. According to such a configuration, a high-speed response can be realized regardless of the use environment, and display quality equivalent to that in a normal temperature environment can be maintained even in a low temperature environment.

  In the liquid crystal display device, it is preferable that the switching element is a TFT element, and the resistance element is electrically connected to a gate electrode of the TFT element.

  According to such a configuration, the TFT element can be switched on and off according to the resistance value of the resistance element, that is, according to the temperature of the liquid crystal, and thus the current flowing to the heater layer can be controlled.

  Here, it is preferable that the resistance element has a characteristic that the resistance value increases as the temperature rises. By doing in this way, when the temperature of the liquid crystal falls below a predetermined value, the switching element can be turned on to allow a current to flow through the heater layer. That is, since the liquid crystal can be heated when the temperature of the liquid crystal falls below a predetermined value, the liquid crystal can be kept at a certain temperature or higher.

  In the liquid crystal display device of the present invention, a pair of substrates arranged opposite to each other, a liquid crystal sealed between the pair of substrates, and an electric current arranged on at least one of the opposed surfaces of the substrate flow. A heater layer heated by the at least one of the opposing surfaces of the substrate, a resistance element whose resistance value varies with temperature, and an opposing surface of the substrate on which the heater layer is formed And a switching element that controls a current flowing through the heater layer in accordance with a voltage signal having a magnitude correlated with the resistance value of the resistance element.

  In the liquid crystal display device having such a configuration, since the resistance element is disposed on the opposite surface of the substrate, the temperature follows the change in the temperature of the liquid crystal without delay, and reflects the actual temperature of the liquid crystal. It has a resistance value. The switching element is switched on and off according to an electric signal having a magnitude correlated with the resistance value of the resistance element. That is, the switching element is switched on and off according to the temperature of the liquid crystal. When the switching element is turned on, a current flows through the heater layer and the liquid crystal is heated. Further, since the heater layer is disposed on the opposite surface of the substrate, the heat of the heater layer is efficiently transmitted to the liquid crystal, and the liquid crystal can be heated quickly. Thus, the liquid crystal display device having the above-described configuration can quickly heat the liquid crystal according to the temperature of the liquid crystal. According to such a configuration, a high-speed response can be realized regardless of the use environment, and display quality equivalent to that in a normal temperature environment can be maintained even in a low temperature environment.

  Here, it is preferable that the resistance value of the resistance element increases as the temperature increases. By doing in this way, when the temperature of the liquid crystal falls below a predetermined value, the switching element can be turned on to allow a current to flow through the heater layer. In other words, the liquid crystal can be heated when the temperature of the liquid crystal falls below a predetermined value.

  The liquid crystal display device preferably includes a plurality of pixels, and the resistance element and the switching element are disposed for each pixel. The liquid crystal display device preferably includes a plurality of pixels including a plurality of sub-pixels, and the resistance element and the switching element are disposed for each sub-pixel.

  According to such a configuration, the resistance element arranged in each pixel or each subpixel has a resistance value corresponding to the temperature of the liquid crystal in each pixel or subpixel. Each switching element controls the current flowing through the heater layer independently of the resistance elements of other pixels or sub-pixels according to the resistance value. For this reason, each pixel or each sub-pixel is heated according to the temperature of the liquid crystal, and even when the temperature of the liquid crystal varies in the plane of the substrate, it is possible to heat while uniforming the variation. it can. Thereby, display unevenness due to temperature variations in the substrate surface can be reduced.

  Here, in the liquid crystal display device, the heater layer is preferably disposed for each pixel. When the pixel has a plurality of sub-pixels, it is preferable that the resistive element is arranged for each sub-pixel.

  In the liquid crystal display device, the resistance element is preferably a PTC (Positive Temperature Coefficient) thermistor. The PTC thermistor has a small change in resistance value with a change in temperature in a temperature region below a predetermined temperature, and the resistance value increases rapidly with the temperature in a temperature region above the predetermined temperature. Therefore, according to the above configuration, a current flows through the heater layer when the temperature falls below the predetermined temperature, and the liquid crystal can always be kept at the predetermined temperature or higher.

  An electronic apparatus according to the present invention includes the liquid crystal display device. According to such a configuration, an electronic device that can achieve a high-speed response regardless of the use environment and can maintain a good display quality is obtained.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the drawings shown below, the dimensions and ratios of the components are appropriately different from the actual ones in order to make the components large enough to be recognized on the drawings.

(First embodiment)
<Configuration of liquid crystal display device>
1A and 1B are schematic views of a liquid crystal display device 1 according to the first embodiment, in which FIG. 1A is a perspective view and FIG. 1B is a cross-sectional view taken along line AA in FIG. The liquid crystal display device 1 includes glass substrates 11 and 21 as substrates of the present invention, which are bonded to each other with a frame-shaped sealing agent 61 therebetween. Liquid crystal 62 is sealed in a space surrounded by the glass substrates 11 and 21 and the sealing agent 61. The glass substrate 21 is larger than the glass substrate 11, and is bonded together in a state in which a part projects from the glass substrate 11. A liquid crystal driver 63 for driving the liquid crystal 62 is mounted on the protruding portion. The liquid crystal display device 1 performs display in the display area 8 in which the liquid crystal 62 is enclosed.

  FIG. 2 is an enlarged plan view of the liquid crystal display device 1. As shown in this figure, the liquid crystal display device 1 has a large number of subpixels 6R, 6G, and 6B (hereinafter collectively referred to as subpixels 6) corresponding to red, green, and blue. The sub-pixels 6 are arranged in a matrix, and the colors of the sub-pixels 6 arranged in a certain column are all the same. In other words, the sub-pixels 6 are arranged so that corresponding colors are arranged in a stripe pattern. A set of three adjacent sub-pixels 6R, 6G, and 6B arranged in the row direction forms one pixel 4. The liquid crystal display device 1 can display various colors in each pixel 4 by appropriately adjusting the luminance balance of the sub-pixels 6R, 6G, and 6B.

  A light shielding layer 14 is disposed between the sub-pixels 6. The light shielding layer 14 serves to improve the contrast of display by blocking light leaking from between the sub-pixels 6. Each sub-pixel 6 is provided with a heater layer 41 for heating the liquid crystal 62.

  Next, the electrical configuration of the liquid crystal display device 1 will be described with reference to FIG. FIG. 3 is an electric block diagram when the liquid crystal display device 1 is viewed from the same direction as FIG. The liquid crystal display device 1 has a plurality of scanning lines 26 and a plurality of data lines 28 arranged in parallel. The scanning line 26 and the data line 28 are orthogonal to each other. The sub-pixel 6 is located in each of the rectangular areas surrounded by the scanning lines 26 and the data lines 28. A scanning signal and a data signal are applied to the scanning line 26 and the data line 28 from a liquid crystal driver 63 (see FIG. 1), respectively.

  In each sub-pixel 6, a TFT (Thin Film Transistor) element 22 as a switching element of the present invention and a pixel electrode 24 are arranged. The gate electrode 22g (see FIG. 4) of the TFT element 22 is connected to the scanning line 26, the source electrode 22s (see FIG. 4) of the TFT element 22 is connected to the data line 28, and the drain electrode 22d of the TFT element 22 (FIG. 4). Reference) is connected to the pixel electrode 24. The TFT element 22 is turned on when a scanning signal is applied to the scanning line 26, and the data signal applied to the data line 28 at this time is transmitted to the pixel electrode 24 via the source electrode 22s and the drain electrode 22d. The liquid crystal 62 is driven by a drive voltage determined by the data signal transmitted to the pixel electrode 24 and the potential of the common electrode 18 (see FIG. 4) disposed to face the pixel electrode 24, and the alignment state changes. The liquid crystal display device 1 thus performs display by manipulating the polarization state of the transmitted light by changing the alignment state of the liquid crystal 62 and extracting light in a predetermined polarization state.

  Each subpixel 6 is provided with a heater layer 41 and a resistance element 42 as a temperature sensor of the present invention. The heater layer 41 and the resistance element 42 are connected in series, and the resistance element 42 is connected to a power supply line 43 arranged in parallel with the scanning line 26. One power supply line 43 is arranged for one row of the sub-pixels 6, and the resistance elements 42 arranged in the sub-pixels 6 in the same row are connected to the same power supply line 43. Each heater layer 41 is connected to the GND potential.

  Here, the positional relationship of the above-described components will be described with reference to FIG. 4A is a schematic cross-sectional view when the liquid crystal display device 1 is cut along the column direction in FIG. 2, and FIG. 4B is a cross-sectional view when the liquid crystal display device 1 is cut along the row direction in FIG. Sometimes it is a schematic cross-sectional view.

On the opposite surface of the glass substrate 21 (that is, the surface on which the liquid crystal 62 is sealed), a GND electrode 44 connected to the GND potential is formed on the entire surface. The GND electrode 44 is made of ITO (Indium Tin Oxide) having optical transparency. A heater layer 41 is formed on the GND electrode 44 with an insulating layer 35a made of SiO ₂ interposed therebetween. The heater layer 41 is made of ITO and has a characteristic of generating heat when a current flows. The amount of heat generation is approximately proportional to the square of the magnitude of the flowing current. The heater layer 41 is connected to the GND electrode 44 through a contact hole provided in the insulating layer 35a.

  In the same layer as the heater layer 41, a resistance element 42 and a feed line 43 electrically connected to the heater layer 41 are formed. A current corresponding to the potential difference between the power supply line 43 and the GND electrode 44 and the resistance value of the resistance element 42 and the heater layer 41 flows through the resistance element 42 and the heater layer 41.

Here, the resistance element 42 is a thermistor having a characteristic that the resistance value increases as the temperature rises. More specifically, the PTC thermistor has a small change in resistance value due to a change in temperature in a temperature range below 30 ° C., and a resistance value that increases rapidly with temperature in a temperature range above 30 ° C. An insulating layer 35 b made of SiO ₂ is formed on the heater layer 41, the resistance element 42, and the power supply line 43.

The TFT element 22 is formed on the insulating layer 35b. TFT element 22 includes a gate electrode 22g formed on the insulating layer 35b, on the gate electrode 22g, and the semiconductor layer 22a formed through a gate insulating layer 35c made of SiO _2, which is connected to the semiconductor layer 22a A drain electrode 22d and a source electrode 22s are provided. The source electrode 22s is connected to the data line 28 (see FIGS. 3 and 4B). An insulating layer 35d made of SiO ₂ is formed on the TFT element 22, and a pixel electrode 24 made of ITO is formed on the insulating layer 35d. The pixel electrode 24 is connected to the drain electrode 22d through a contact hole provided in the insulating layer 35d. On the pixel electrode 24, an alignment film (not shown) made of polyimide is formed. Hereinafter, the glass substrate 21 and the above-described components formed on the glass substrate 21 are collectively referred to as an element substrate 20.

  On the other hand, color filters 12R, 12G, and 12B corresponding to red, green, and blue (hereinafter collectively referred to as color filter 12) are formed on the opposing surface of the glass substrate 11. The color filter 12 is a resin that colors transmitted light by absorbing light in a specific wavelength range. The color filters 12R, 12G, and 12B are formed in the sub-pixels 6R, 6G, and 6B, respectively. A light shielding layer 14 made of resin is formed between the color filters 12R, 12G, and 12B. On the color filter 12 and the light shielding layer 14, an overcoat 16 having optical transparency and a common electrode 18 made of ITO are laminated in this order. On the common electrode 18, an alignment film (not shown) made of polyimide is formed. Hereinafter, the glass substrate 11 and the above-described components formed on the glass substrate 11 are collectively referred to as a color filter substrate 10. A liquid crystal 62 is sealed between the color filter substrate 10 and the element substrate 20.

<LCD heating function>
Next, the function of the liquid crystal display device 1 for heating the liquid crystal 62 will be described.

The liquid crystal 62 has a characteristic that the characteristics change depending on the temperature, and the temperature dependence of the response speed is particularly large. A curve b in FIG. 16 shows how the response speed of the liquid crystal included in the liquid crystal display device that does not have the liquid crystal heating function changes as the outside air temperature changes. In this case, since the temperature of the liquid crystal is substantially equal to the outside air temperature, it can be said that the curve b shows the temperature dependence of the response speed of the liquid crystal. The response speed in this figure is defined by τ _on + τ _off , and τ _on is the white display state (hereinafter, the luminance at this time) on the liquid crystal 62 in the black display state (hereinafter, the luminance at this time is “0%”). Is set to “100%”), and the time from the start of the application until the luminance becomes 90% is applied, and τ _off is the black display state in the liquid crystal 62 in the white display state. This is the time from the start of application until the luminance reaches 10% when the corresponding drive voltage is applied. As can be seen from this figure, the response speed of the liquid crystal 62 decreases as the outside air temperature decreases. In particular, it is 0.1 seconds or more under a freezing environment, and it reaches 1 second or more at a lower temperature. In the liquid crystal display device 1 in such a state, display switching is delayed due to a decrease in the response speed of the liquid crystal 62, or a moving image is disturbed, resulting in a deterioration in display quality. From such a viewpoint, the response speed of the liquid crystal 62 is preferably faster than 16 msec. When the response speed is 16 msec or more, the display can be rewritten 60 times per second (that is, 60 Hz). In order to realize this response speed, it is necessary to keep the temperature of the liquid crystal 62 at about 30 ° C. or higher from FIG.

  The liquid crystal display device 1 of this embodiment can maintain the liquid crystal 62 at a temperature of about 30 ° C. or higher by the functions of the heater layer 41 and the resistance element 42. Hereinafter, this will be described in detail with reference to FIGS.

  The potential difference between the feeder line 43 and the GND electrode 44 is kept at a predetermined value. The power supply line 43, the resistance element 42, the heater layer 41, and the GND electrode 44 are connected in series in this order. Among these, as described above, the resistance element 42 has a small change in resistance value due to a change in temperature in a temperature region below 30 ° C., and the resistance value rapidly increases with the temperature in a temperature region above 30 ° C. It is a PTC thermistor.

  Further, the temperature of the resistance element 42 is always substantially equal to the temperature of the liquid crystal 62. This is because the resistance element 42 is disposed on the opposite surface of the glass substrate 21, so that the distance from the liquid crystal 62 is only about several μm, and the heat transmitted to the liquid crystal 62 is applied to the resistance element 42 almost simultaneously. Because it is also transmitted. Therefore, when the temperature of the liquid crystal 62 changes, the temperature of the resistance element 42 changes without delay, and the resistance element 42 always has a resistance value that reflects the temperature of the liquid crystal 62.

  Hereinafter, the operation | movement according to the use environmental temperature (outside temperature) of the liquid crystal display device 1 is demonstrated. First, when the outside air temperature is 30 ° C. or higher, the temperature of the liquid crystal 62, that is, the temperature of the resistance element 42 also follows this and becomes 30 ° C. or higher. At this time, since the resistance value of the resistance element 42 is maintained at a high value, almost no current flows through the resistance element 42 and the heater layer 41. Therefore, the heater layer 41 is not heated. At this time, the liquid crystal 62 has a sufficient response speed as shown in FIG.

  On the other hand, when the outside air temperature is lower than 30 ° C., the temperature of the liquid crystal 62, that is, the temperature of the resistance element 42 follows this and becomes lower than 30 ° C. At this time, the resistance value of the resistance element 42 rapidly decreases, and a current flows through the resistance element 42 and the heater layer 41. As a result, the heater layer 41 is heated, and the heat is transferred to the liquid crystal 62 so that the liquid crystal 62 is also heated. Here, since the heater layer 41 is disposed on the opposing surface of the glass substrate 21, the heat of the heater layer 41 is efficiently transmitted to the liquid crystal 62, and the liquid crystal 62 can be heated quickly.

  As a result of the heating, when the temperature of the liquid crystal 62, that is, the temperature of the resistance element 42 becomes 30 ° C. or higher again, the resistance value of the resistance element 42 is maintained at a high value, and no current flows through the resistance element 42 and the heater layer 41. Heating stops. At this time, if the outside air temperature is still below 30 ° C., the temperature of the liquid crystal 62 and the resistance element 42 is decreased to below 30 ° C., and then the heating is performed again as described above. By repeating these operations, the temperature of the liquid crystal 62 is maintained at about 30 ° C. even if the outside air temperature is less than 30 ° C. Thus, the resistance element 42 has a function of controlling the current flowing through the heater layer as well as the function of the temperature sensor, and corresponds to the temperature sensor and the control unit in the present invention.

  From the above, the response speed of the liquid crystal 62 in the liquid crystal display device 1 is always maintained at a speed higher than 16 msec regardless of the outside temperature, as shown by the curve a in FIG.

  Further, in the liquid crystal display device 1, a separate resistive element 42 and heater layer 41 are formed in each subpixel 6. Since these resistance elements 42 have a resistance value corresponding to the temperature of the liquid crystal 62 in each sub-pixel 6, the resistance elements 42 are independent of the resistance elements 42 of the other sub-pixels 6 depending on the resistance value. The current flowing through the heater layer 41 is controlled. For example, when the temperature of the liquid crystal 62 is uneven due to the operating heat of the liquid crystal driver 63 or the heat from the external lighting device, and the temperature of the liquid crystal 62 is below 30 ° C. only in some of the sub-pixels 6, Only the resistance element 42 formed in the sub-pixel 6 has a lower resistance value, a current flows through the heater layer 41, and the liquid crystal 62 is heated. Thus, in each sub-pixel 6, heating is performed according to the temperature of the liquid crystal 62 at that position, and even when the temperature of the liquid crystal 62 varies in the plane, heating is performed while uniforming the variation. be able to. Thereby, display unevenness due to temperature variation can be reduced.

  As described above, the liquid crystal display device 1 of the present embodiment can heat the liquid crystal 62 to a uniform temperature even in a low temperature environment. For this reason, a high-speed response can be realized regardless of the use environment, and good display quality can be maintained.

(Second Embodiment)
<Configuration of liquid crystal display device>
Next, a liquid crystal display device 1A according to a second embodiment of the present invention will be described with reference to the electric block diagram of FIG. 5 and the cross-sectional view of FIG. The liquid crystal display device 1A is different from the liquid crystal display device 1 according to the first embodiment in the configuration related to the liquid crystal heating function, but the other configuration related to the display is the same as the liquid crystal display device 1. For this reason, the difference from the liquid crystal display device 1 will be mainly described below, and the same components as those in FIG. 3 and FIG.

  First, the electrical configuration relating to the liquid crystal heating function of the liquid crystal display device 1A will be described with reference to FIG. The liquid crystal display device 1 </ b> A has gate lines 45 parallel to the scanning lines 26, one for each row of the sub-pixels 6. One feed line 43 parallel to the data line 28 is provided for each column of the sub-pixels 6. A resistance element 42 as a temperature sensor of the present invention and a TFT element 46 as a switching element of the present invention are formed at a position corresponding to the intersection of the gate line 45 and the power supply line 43. One resistive element 42 and one TFT element 46 are formed for each sub-pixel 6. The resistance element 42 is connected to the gate line 45 and to the gate electrode 46g (see FIG. 6) of the TFT element 46. The source electrode 46s (see FIG. 6) of the TFT element 46 is connected to the feeder line 43, and the drain electrode 46d (see FIG. 6) is connected to the heater layer 41. One heater layer 41 is formed for each sub-pixel 6 and is connected to the GND potential.

  Here, the positional relationship of the above-described components will be described with reference to FIG. 6A is a schematic cross-sectional view when the liquid crystal display device 1A is cut in the column direction in FIG. 2, and FIG. 6B is a cross-sectional view in which the liquid crystal display device 1A is cut in the row direction in FIG. Sometimes it is a schematic cross-sectional view.

On the opposite surface of the glass substrate 21, a GND electrode 44 connected to the GND potential is formed on the entire surface, and an insulating layer 36a made of SiO ₂ is formed on the GND electrode 44. A TFT element 46 is formed on the insulating layer 36a. The TFT element 46 is connected to the semiconductor layer 46a, a gate electrode 46g formed on the insulating layer 36a, a semiconductor layer 46a formed on the gate electrode 46g via a gate insulating layer 36b made of SiO ₂ , and the like. A drain electrode 46d and a source electrode 46s are provided. The gate electrode 46g is connected to the gate line 45 through a resistance element 42 which is also formed on the insulating layer 36a. The source electrode 46s is connected to the power supply line 43 (see FIGS. 5 and 6B). An insulating layer 36c made of SiO ₂ is formed on the TFT element 46, and a heater layer 41 made of ITO is formed on the insulating layer 36c. The heater layer 41 is connected to the drain electrode 46d through a contact hole provided in the insulating layer 36c. The heater layer 41 is connected to the GND electrode 44 through a contact hole provided through the insulating layers 36c, 36b, 36a. As in the first embodiment, the heater layer 41 has a characteristic of generating heat when a current flows, and the resistance element 42 is a PTC thermistor whose resistance value increases rapidly with temperature at 30 ° C. .

The TFT element 22 is formed on the insulating layer 36c. TFT element 22 includes a gate electrode 22g formed on the insulating layer 36c, on the gate electrode 22g, and the semiconductor layer 22a formed through a gate insulating layer 36d made of SiO _2, which is connected to the semiconductor layer 22a A drain electrode 22d and a source electrode 22s are provided. The source electrode 22s is connected to the data line 28 (see FIGS. 5 and 6B). An insulating layer 36e made of SiO ₂ is formed on the TFT element 22, and a pixel electrode 24 made of ITO is formed on the insulating layer 36e. The pixel electrode 24 is connected to the drain electrode 22d through a contact hole provided in the insulating layer 36e. On the pixel electrode 24, an alignment film (not shown) made of polyimide is formed. The glass substrate 21 and the above-described components formed on the glass substrate 21 constitute the element substrate 20. Since the configuration of the color filter substrate 10 is the same as that of the liquid crystal display device 1 of the first embodiment, the description thereof is omitted.

<LCD heating function>
The liquid crystal display device 1 </ b> A of the present embodiment can maintain the liquid crystal 62 at a temperature of about 30 ° C. or higher by the functions of the heater layer 41, the resistance element 42, and the TFT 46. This will be described in detail below with reference to FIGS.

  The liquid crystal display device 1A basically heats the liquid crystal 62 by the following mechanism. First, the gate line 45 is always kept at a potential for turning on the TFT element 46. However, since the resistance element 42 is disposed between the gate line 45 and the gate electrode 46g of the TFT element 46, the TFT element 46 is turned on only when the resistance value of the resistance element 42 is a predetermined value or less. It becomes. Further, the potential difference between the feeder line 43 and the GND electrode 44 is kept at a predetermined value. When the TFT element 46 is turned on, a current flows through the path of the power supply line 43, the source electrode 46s, the drain electrode 46d, the heater layer 41, and the GND electrode 44, and the heater layer 41 is heated.

  Here, the resistance element 42 is disposed on the opposing surface of the glass substrate 21. Therefore, similarly to the first embodiment, the temperature of the resistance element 42 changes without delay when the temperature of the liquid crystal 62 changes and always has a resistance value that reflects the temperature of the liquid crystal 62. Become.

  Hereinafter, an operation according to the use environment temperature (outside temperature) of the liquid crystal display device 1A will be described. First, when the outside air temperature is 30 ° C. or higher, the temperature of the liquid crystal 62, that is, the temperature of the resistance element 42 also follows this and becomes 30 ° C. or higher. At this time, since the resistance value of the resistance element 42 is maintained at a high value, the TFT element 46 is maintained in an off state, and no current flows from the power supply line 43 to the heater layer 41. Therefore, the heater layer 41 is not heated. At this time, the liquid crystal 62 has a sufficient response speed as shown in FIG.

  On the other hand, when the outside air temperature is lower than 30 ° C., the temperature of the liquid crystal 62, that is, the temperature of the resistance element 42 follows this and becomes lower than 30 ° C. At this time, the resistance value of the resistance element 42 rapidly decreases, and the TFT element 46 is turned on. Then, a current flows through the heater layer 41 and the heater layer 41 is heated, and the heat is transmitted to the liquid crystal 62 and the liquid crystal 62 is also heated. Here, since the heater layer 41 is disposed on the opposing surface of the glass substrate 21, the heat of the heater layer 41 is efficiently transmitted to the liquid crystal 62, and the liquid crystal 62 can be heated quickly.

  As a result of the heating, when the temperature of the liquid crystal 62, that is, the temperature of the resistance element 42 becomes 30 ° C. or more again, the resistance value of the resistance element 42 is maintained at a high value, and the TFT element 46 is turned off. As a result, supply of current to the heater layer 41 is stopped, and heating of the liquid crystal 62 is stopped. At this time, if the outside air temperature is still below 30 ° C., the temperature of the liquid crystal 62 and the resistance element 42 is decreased to below 30 ° C., and then the heating is performed again as described above. By repeating these operations, the temperature of the liquid crystal 62 is maintained at about 30 ° C. even if the outside air temperature is less than 30 ° C. Thus, the resistance element 42 and the TFT element 46 have a function of controlling the current flowing through the heater layer, and correspond to the control unit in the present invention.

  From the above, the response speed of the liquid crystal 62 in the liquid crystal display device 1A is always maintained at a speed higher than 16 msec regardless of the outside temperature, as shown by the curve a in FIG.

  Further, in the liquid crystal display device 1 </ b> A, a separate resistive element 42, heater layer 41, and TFT element 46 are formed in each subpixel 6. Among these, the resistance element 42 has a resistance value corresponding to the temperature of the liquid crystal 62 in each sub-pixel 6. For this reason, the TFT element 46 operates independently of the TFT elements 46 of the other sub-pixels 6 according to the resistance value of the resistance element 42 connected thereto, and controls the supply of current to the heater layer 41. . Therefore, each sub-pixel 6 is heated according to the temperature of the liquid crystal 62 at that position, and even when the temperature of the liquid crystal 62 varies in the plane, the sub-pixel 6 can be heated while uniforming the variation. it can. Thereby, display unevenness due to temperature variation can be reduced.

  As described above, the liquid crystal display device 1A according to the present embodiment can heat the liquid crystal 62 to a uniform temperature even in a low temperature environment. For this reason, a high-speed response can be realized regardless of the use environment, and good display quality can be maintained. Since the current for heating the heater layer 41 does not flow through the resistance element 42 of the present embodiment, it is suitable when the rated current of the resistance element 42 is small.

(Third embodiment)
<Configuration of liquid crystal display device>
Subsequently, a liquid crystal display device 1B according to a third embodiment of the present invention will be described with reference to an electric block diagram of FIG. 7 and a functional block diagram of FIG. The liquid crystal display device 1B is different from the liquid crystal display device 1A of the second embodiment in the configuration related to the liquid crystal heating function, but the other configuration related to the display is the same as that of the liquid crystal display device 1A. Therefore, hereinafter, differences from the liquid crystal display device 1A will be mainly described, and the same components as those in FIGS.

  FIG. 7 is a block diagram showing an electrical configuration of the liquid crystal display device 1B. The liquid crystal display device 1 </ b> B includes a temperature detection mechanism for detecting the temperature of the liquid crystal 62 in each sub-pixel 6 and a liquid crystal heating mechanism for heating the liquid crystal 62 of each sub-pixel 6. For convenience of explanation, only the temperature detection mechanism is extracted and drawn in the rightmost sub-pixel 6 in FIG. 7, and only the liquid crystal heating mechanism is extracted and drawn in the leftmost sub-pixel 6 in FIG. It is. The sub-pixels 6 in the middle three rows in FIG. 7 are drawn with a temperature detection mechanism and a liquid crystal heating mechanism in an overlapping manner.

  The temperature detection mechanism includes a search line 47 and a detection line 49 arranged in parallel with the data line 28, a resistance element 42, and a TFT element 48. One search line 47 and one detection line 49 are arranged for each column of the sub-pixels 6, and one resistance element 42 and one TFT element 48 are arranged for each sub-pixel 6. A gate electrode of the TFT element 48 is connected to the scanning line 26. The source electrode of the TFT element 48 is connected to the exploration line 47 through the resistance element 42, and the drain electrode is connected to the detection line 49. As in the first embodiment, the resistance element 42 is a PTC thermistor formed on the opposing surface of the glass substrate 21 and has a characteristic that the resistance value increases rapidly with temperature at 30 ° C. as a boundary.

  The liquid crystal heating mechanism is arranged in parallel with the data lines 28, one for each row of the sub-pixels 6, one for the gate lines 45 arranged in parallel with the scanning lines 26, and one for each column of the sub-pixels 6. The power supply line 43, the TFT element 46 as the switching element of the present invention, and the heater layer 41, which are arranged corresponding to the intersection of the gate line 45 and the power supply line 43, are provided. One TFT element 46 and one heater layer 41 are formed for each sub-pixel 6. The TFT element 46 has a gate electrode connected to the gate line 45, a source electrode connected to the feeder line 43, and a drain electrode connected to the heater layer 41. Each heater layer 41 is connected to the GND potential. Similar to the second embodiment, the heater layer 41 is formed on the opposing surface of the glass substrate 21 and has a characteristic of generating heat when a current flows.

  The liquid crystal display device 1B further includes a heater driver 64 and a detection unit 65 as shown in FIG. A liquid crystal panel 2 in FIG. 8 indicates a portion of the liquid crystal display device 1 </ b> B including the color filter substrate 10, the element substrate 20, the sealing agent 61, and the liquid crystal 62.

<LCD heating function>
The liquid crystal display device 1B of the present embodiment can keep the temperature of the liquid crystal 62 at about 30 ° C. or higher due to the functions of the above components. Hereinafter, this will be described in detail with reference to FIGS.

  The liquid crystal display device 1B basically heats the liquid crystal 62 by the following mechanism. That is, temperature information of the liquid crystal 62 of each sub-pixel 6 is detected by the temperature detection mechanism and detection unit 65, and the liquid crystal 62 is heated by the function of the liquid crystal heating mechanism according to the result. The liquid crystal heating mechanism is driven by a heater driver 64.

  The search line 47 and the detection line 49 included in the temperature detection mechanism are always kept at a predetermined potential difference. When a scanning signal is applied to the scanning line 26 and the TFT element 48 is turned on, an inspection current corresponding to the temperature of the liquid crystal 62 of the subpixel 6 is sent from the search line 47 to the resistance element 42 and the source of the TFT element 48. It flows to the detection line 49 through the electrode and the drain electrode. More specifically, when the temperature of the liquid crystal 62 (that is, the temperature of the resistance element 42) is 30 ° C. or higher, since the resistance value of the resistance element 42 is maintained at a high value, almost no current flows through the detection line 49. . On the other hand, when the temperature of the liquid crystal 62, that is, the temperature of the resistance element 42 falls below 30 ° C., the resistance value of the resistance element 42 rapidly decreases, so that a current corresponding to the temperature of the liquid crystal 62 is applied to the detection line 49. Flowing.

  The detection unit 65 is connected to the detection line 49 and detects a current flowing through the detection line 49. Since the inspection current of the sub-pixel 6 scanned by the scanning line 26 sequentially flows through one detection line 49, the liquid crystal of all the sub-pixels 6 connected to the detection line 49 is detected by detecting this inspection current. 62 temperature information can be detected. Then, by detecting the inspection current from all the detection lines 49, the temperature information of the liquid crystals 62 of all the sub-pixels 6 in the liquid crystal display device 1B can be detected. The detection unit 65 creates temperature distribution data from the obtained temperature information and outputs it to the heater driver 64.

  The heater driver 64 transmits a scanning signal to the gate line 45 and a power supply signal to the power supply line 43 based on the temperature distribution data input from the detection unit 65. More specifically, when the TFT element 46 of each sub-pixel 6 is turned on by the scanning signal and the temperature of the liquid crystal 62 of the sub-pixel 6 is less than 30 ° C., a high potential power supply signal is 30 ° C. or more. In this case, the scanning signal and the power feeding signal are transmitted so that the power feeding signal having a low potential is applied. As a result, a current flows through the heater layer 41 of the sub-pixel 6 where the temperature of the liquid crystal 62 is less than 30 ° C. and heating is performed, and no current is supplied to the heater layer 41 of the sub-pixel 6 where the temperature is 30 ° C. or higher. There is no heating. Here, the scanning signal and the power feeding signal transmitted by the heater driver 64 correspond to the voltage signal in the present invention.

  As a result of the heating, when the temperature of the liquid crystal 62, that is, the temperature of the resistance element 42 becomes 30 ° C. or higher, the resistance value of the resistance element 42 is maintained at a high value and no inspection current flows. Is not supplied, and the heating of the liquid crystal 62 is stopped. At this time, when the outside air temperature is less than 30 ° C., the temperature of the liquid crystal 62 and the resistance element 42 is decreased to below 30 ° C., and then the heating is performed again as described above.

  By repeating these operations, the temperature of the liquid crystal 62 is maintained at about 30 ° C. or higher regardless of the outside air temperature. Thus, the resistance element 42 and the TFT element 46 have a function of controlling the current flowing through the heater layer, and correspond to the control unit in the present invention. From the above, the response speed of the liquid crystal 62 in the liquid crystal display device 1B is always maintained at a speed higher than 16 msec regardless of the outside temperature, as shown by the curve a in FIG.

  Further, since the above-described heating is performed independently for each sub-pixel 6, even when the temperature of the liquid crystal 62 varies in the plane, the heating can be performed while uniforming the variation. Thereby, display unevenness due to temperature variation can be reduced.

  As described above, the liquid crystal display device 1B of the present embodiment can heat the liquid crystal 62 to a uniform temperature even in a low temperature environment. For this reason, a high-speed response can be realized regardless of the use environment, and good display quality can be maintained. Since the current for heating the heater layer 41 does not flow through the resistance element 42 of the present embodiment, it is suitable when the rated current of the resistance element 42 is small.

(Electronics)
The above-described liquid crystal display device 1 (including the liquid crystal display devices 1A and 1B) can be used by being mounted on, for example, a mobile phone 100 as an electronic device as shown in FIG. The mobile phone 100 has a display unit 110 and operation buttons 120. Since the liquid crystal display device 1 incorporated in the display unit 110 responds at a high speed regardless of the use environment, the display unit 110 displays various information including the content input by the operation buttons 120 and moving images with high quality. Can do.

  The liquid crystal display device 1 to which the present invention is applied can be used for various electronic devices such as a mobile computer, a digital camera, a digital video camera, an in-vehicle device, and an audio device in addition to the mobile phone 100 described above.

  As mentioned above, although embodiment of this invention was described, various deformation | transformation can be added with respect to the said embodiment in the range which does not deviate from the meaning of this invention. As modifications, for example, the following can be considered.

(Modification 1)
In each of the above embodiments, the resistance element 42 and the heater layer 41 are provided for each sub-pixel 6 to perform heating. However, the present invention is not limited to this, and the liquid crystal heating function including the resistance element 42 and the heater layer 41 is used. For example, the constituent elements may be provided for each pixel 4 (see FIG. 2) including three sub-pixels 6.

  FIG. 9 is an electric block diagram of the liquid crystal display device 1C having a configuration in which the resistive element 42 and the heater layer 41 are arranged for each pixel 4 including the sub-pixels 6R, 6G, and 6B in the liquid crystal display device 1 of the first embodiment. It is. FIG. 10 shows a liquid crystal display having a configuration in which the resistive element 42, the TFT element 46, and the heater layer 41 are arranged for each pixel 4 including the sub-pixels 6R, 6G, and 6B in the liquid crystal display device 1A of the second embodiment. It is an electrical block diagram of apparatus 1D. According to such a configuration, in each pixel 4, the heating according to the temperature of the liquid crystal 62 in the pixel 4 is performed independently of the other pixels 4, and the temperature of the liquid crystal 62 varies in the plane. Even so, heating can be performed while making the variation uniform. Thereby, display unevenness due to temperature variation can be reduced. In addition, since the number of the resistive elements 42 and the TFT elements 46 can be reduced as compared with the case where the resistive elements 42 and the TFT elements 46 are arranged for each subpixel 6, the yield can be improved and each pixel can be improved. The transmittance at 4 can be improved. In the description of FIGS. 9 and 10 described above, the same components as those in FIGS. 3 and 5 are denoted by the same reference numerals and description thereof is omitted.

  Furthermore, the component relating to the liquid crystal heating function including the resistance element 42 and the heater layer 41 may be provided for each larger region. For example, it may be provided for each region composed of four pixels 4 in 2 rows and 2 columns or for each region composed of 9 pixels 4 in 3 rows and 3 columns.

(Modification 2)
In each of the embodiments described above, the resistance element 42 and the heater layer 41 are formed on the element substrate 20 side. Alternatively, the resistor element 42 and the heater layer 41 may be formed on the color filter substrate 10 side. FIG. 11 shows a cross-sectional view of a liquid crystal display device 1E when the liquid crystal display device 1 of the first embodiment is modified to such a configuration. On the element substrate 20 side of the liquid crystal display device 1E, a TFT element 22 formed on the glass substrate 21 and a pixel electrode 24 are arranged. More particularly, TFT element 22 includes a gate electrode 22g formed on the glass substrate 21, on the gate electrode 22g, and the semiconductor layer 22a formed through a gate insulating layer 37a made of SiO _2, the semiconductor layer 22a A drain electrode 22d and a source electrode 22s connected to each other, an insulating layer 37b made of SiO ₂ is formed on the TFT element 22, and a pixel electrode 24 made of ITO is formed on the insulating layer 37b. . The pixel electrode 24 is connected to the drain electrode 22d through a contact hole provided in the insulating layer 37b.

  On the other hand, on the color filter substrate 10 side, a GND electrode 44 formed on the opposite surface of the glass substrate 11, a heater layer 41 formed on the GND electrode 44 with an insulating layer 38 c sandwiched therebetween, a resistance element 42, and a feeder line 43 are arranged. The heater layer 41 is connected to the GND electrode 44 through a contact hole provided in the insulating layer 38c. The color filter 12 (12G) and the light shielding layer 14 are formed on the heater layer 41, the resistance element 42, and the power supply line 43, and the overcoat 16 and the common electrode 18 made of ITO are laminated on the color filter 12 (12G). ing. Also in the liquid crystal display device 1E having such a configuration, the temperature of the liquid crystal 62 can be heated to a uniform temperature by the heater layer 41 even in a low temperature environment, so that a high-speed response can be realized regardless of the use environment. And good display quality can be maintained.

(Modification 3)
Each of the above embodiments has a configuration in which the heater layer 41 is disposed at the substantially central portion of the sub-pixel 6. However, instead of this, the heater layer 41 may be formed between the sub-pixels 6. As an example, FIG. 12 shows an electrical block diagram and FIG. 13 shows a cross-sectional view of the liquid crystal display device 1F when the liquid crystal display device 1 of the first embodiment is modified to such a configuration. Since the liquid crystal display device 1F is the same as the liquid crystal display device 1 of the first embodiment except for the arrangement position of the heater layer 41 and the resistance element 42, FIG. 3 and FIG. The same components are denoted by the same reference numerals and the description thereof is omitted.

  As shown in FIGS. 12 and 13, even when the heater layer 41 is disposed only between the sub-pixels 6, the distance between the heater layer 41 and the liquid crystal 62 is close and the distance between the heater layers 41 is sufficiently small. The liquid crystal 62 can be heated uniformly. According to such a configuration, since the heater layer 41 and the resistance element 42 are not present in the region contributing to display, display luminance can be improved.

  In addition, since the heater layer 41 is positioned directly below the light shielding layer 14, a material having no light transmission property can be used. For example, the heater layer 41 can be made of a metal such as molybdenum or chromium. According to such a configuration, the heating efficiency can be further improved.

  Further, when a metal is used for the heater layer 41, the heater layer 41 can also function as the light shielding layer 14 without forming the light shielding layer 14. According to such a configuration, the manufacturing process of the liquid crystal display device 1F can be simplified, and the material to be used can be reduced.

(Modification 4)
Each of the above embodiments and each modification relates to an active matrix drive type liquid crystal display device using the TFT element 22 as a switching element. Instead, a TFD (Thin Film Diode) element is used as the switching element. , Passive matrix drive type, liquid crystal mode TN (Twisted Nematic) mode, STN (Super Twisted Nematic) mode, IPS (In-Plane Switching) type or FFS (Fringe) -Field Switching) method, etc.

  Among the above, a liquid crystal display device 1G when the present invention is applied to an FFS liquid crystal display device will be described with reference to an enlarged plan view of FIG. 14 and a cross-sectional view of FIG. The configuration related to the liquid crystal heating function of the liquid crystal display device 1G is the same as that of the liquid crystal display device 1 of the first embodiment. For this reason, the same components as those in FIG. 3 and FIG.

  As shown in FIG. 14, the pixel electrode 24 of the liquid crystal display device 1 </ b> G has many long rectangular openings 25. The openings 25 are arranged in parallel and at equal intervals so that their long sides are adjacent to each other. As shown in FIG. 15, the pixel electrode 24 is formed on the insulating layer 35e in the uppermost stage of the element substrate 20, and the TFT element 22 is connected via a contact hole provided through the insulating layers 35e and 35d. Connected to the drain electrode 22d.

  In the liquid crystal display device 1G, the common electrode 18 is formed between the insulating layer 35d and the insulating layer 35e in the element substrate 20, not on the color filter substrate 10 side. When a driving voltage is applied between the pixel electrode 24 and the common electrode 18 under such a configuration, an electric field in a direction parallel to the substrate surface is applied to the liquid crystal 62, and the liquid crystal 62 is driven by the electric field. The Since this electric field is applied not only to the liquid crystal 62 present on the pixel electrode 24 but also to the liquid crystal 62 present on the opening 25, the viewing angle, contrast, brightness, and the like are better than those of the IPS method. It is done.

  Also in the liquid crystal display device 1G having such a configuration, the temperature of the liquid crystal 62 is made uniform even in a low temperature environment by the functions of the heater layer 41, the resistance element 42, and the like formed on the opposing surface of the glass substrate 21. Since it can be heated, a high-speed response can be realized regardless of the use environment, and good display quality can be maintained.

(Modification 5)
In each of the embodiments described above, the resistance element 42 has a PTC in which the resistance value changes little with a change in temperature in a temperature region below 30 ° C., and the resistance value increases rapidly with the temperature in a temperature region above 30 ° C. Although the thermistor is used, the present invention is not limited to this. For example, when a PTC thermistor is used, the temperature at which the rate of change in resistance value greatly changes can be set to an arbitrary temperature of 30 ° C. to 60 ° C. instead of 30 ° C. By setting this temperature high, the liquid crystal 62 can be maintained at a higher temperature, and the response speed of the liquid crystal 62 can be increased. The resistance element 42 may be a temperature variable resistor other than the PTC thermistor.

BRIEF DESCRIPTION OF THE DRAWINGS It is a schematic diagram of the liquid crystal display device which concerns on this invention, (a) is a perspective view, (b) is sectional drawing in the AA in (a). The enlarged plan view of a liquid crystal display device. 1 is an electrical block diagram of a liquid crystal display device according to a first embodiment. (A) And (b) is a schematic cross section of the liquid crystal display device which concerns on 1st Embodiment. The electric block diagram of the liquid crystal display device which concerns on 2nd Embodiment. (A) And (b) is a schematic cross section of the liquid crystal display device which concerns on 2nd Embodiment. The electric block diagram of the liquid crystal display device which concerns on 3rd Embodiment. The functional block diagram of the liquid crystal display device which concerns on 3rd Embodiment. The electric block diagram of the liquid crystal display device which concerns on the modification of this invention. The electric block diagram of the liquid crystal display device which concerns on the modification of this invention. The schematic cross section of the liquid crystal display device which concerns on the modification of this invention. The electric block diagram of the liquid crystal display device which concerns on the modification of this invention. The schematic cross section of the liquid crystal display device which concerns on the modification of this invention. The enlarged plan view of the liquid crystal display device which concerns on the modification of this invention. The schematic cross section of the liquid crystal display device which concerns on the modification of this invention. The figure which shows the temperature dependence of the response speed of a liquid crystal. 1 is a schematic perspective view of a mobile phone as an electronic apparatus of the present invention.

Explanation of symbols

1, 1A, 1B, 1C, 1D, 1E, 1F, 1G ... Liquid crystal display device, 4 ... Pixel, 6, 6R, 6G, 6B ... Subpixel, 10 ... Color filter substrate, 11, 21 ... Glass substrate, 12, 12R, 12G, 12B ... Color filter, 14 ... Light-shielding layer, 16 ... Overcoat, 18 ... Common electrode, 20 ... Element substrate, 22, 46, 48 ... TFT element, 22a, 46a ... Semiconductor layer, 22d, 46d ... Drain Electrode, 22g, 46g ... Gate electrode, 22s, 46s ... Source electrode, 24 ... Pixel electrode, 26 ... Scan line, 28 ... Data line, 41 ... Heater layer, 42 ... Resistance element, 43 ... Feed line, 44 ... GND electrode , 45 ... gate line, 47 ... exploration line, 49 ... detection line, 61 ... sealant, 62 ... liquid crystal, 63 ... liquid crystal driver, 64 ... heater driver, 65 ... detection unit, 100 ... mobile phone.

Claims (12)

A pair of substrates disposed opposite to each other;
Liquid crystal sealed between the pair of substrates;
A heater layer disposed on an opposing surface of at least one of the substrates and heated by flowing current;
A control unit having a temperature sensor disposed on an opposing surface of at least one of the substrates, and a control unit for passing a current to the heater layer according to a temperature detected by the temperature sensor;
A liquid crystal display device comprising: The liquid crystal display device according to claim 1,
A plurality of the control unit,
The liquid crystal display device, wherein the control units are arranged in a matrix on the opposing surface of the substrate. A pair of substrates disposed opposite to each other;
Liquid crystal sealed between the pair of substrates;
A heater layer disposed on an opposing surface of at least one of the substrates and heated by flowing current;
A resistance element that is arranged in a state of being connected in series with the heater layer on the opposite surface of the substrate on which the heater layer is formed, and having a resistance value that varies with temperature, A resistance element controlled according to the resistance value;
A liquid crystal display device comprising: The liquid crystal display device according to claim 3,
Having a plurality of pixels,
The liquid crystal display device, wherein the resistance element is disposed for each pixel. The liquid crystal display device according to claim 3,
Having a plurality of pixels composed of a plurality of sub-pixels;
The liquid crystal display device, wherein the resistive element is arranged for each of the sub-pixels. A pair of substrates disposed opposite to each other;
Liquid crystal sealed between the pair of substrates;
A heater layer disposed on an opposing surface of at least one of the substrates and heated by flowing current;
A resistance element that is disposed on the opposite surface of the substrate on which the heater layer is formed and has a resistance value that varies with temperature;
A switching element that is disposed on an opposite surface of the substrate on which the heater layer is formed, and that controls a current flowing through the heater layer according to the resistance value of the resistance element;
A liquid crystal display device comprising: The liquid crystal display device according to claim 6,
The switching element is a TFT element,
The liquid crystal display device, wherein the resistance element is electrically connected to a gate electrode of the TFT element. A pair of substrates disposed opposite to each other;
Liquid crystal sealed between the pair of substrates;
A heater layer disposed on an opposing surface of at least one of the substrates and heated by flowing current;
A resistance element that is disposed on the opposing surface of at least one of the substrates and has a resistance value that varies with temperature;
A switching element that is disposed on the opposite surface of the substrate on which the heater layer is formed and that controls a current flowing through the heater layer according to a voltage signal having a magnitude correlated with the resistance value of the resistance element;
A liquid crystal display device comprising: A liquid crystal display device according to any one of claims 6 to 8,
Having a plurality of pixels,
The liquid crystal display device, wherein the resistance element and the switching element are arranged for each pixel. A liquid crystal display device according to any one of claims 6 to 8,
Having a plurality of pixels composed of a plurality of sub-pixels;
The liquid crystal display device, wherein the resistance element and the switching element are arranged for each of the sub-pixels. A liquid crystal display device according to any one of claims 1 to 10,
The liquid crystal display device, wherein the resistance element is a PTC thermistor. An electronic apparatus comprising the liquid crystal display device according to any one of claims 1 to 11.

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