JP2006201575A - Liquid crystal display - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a liquid crystal display with which display grade can be made high and which is equipped with a liquid crystal display panel and a touch panel in regard to the liquid crystal display equipped with the liquid crystal display panel and the touch panel. <P>SOLUTION: The touch panel 11 in which a transparent electrode 14 of a lower side electrode material 12 and a transparent electrode 18 of an upper side electrode material 16 face each other is stuck together onto the liquid crystal display panel 2. When temperature of the liquid crystal display panel 2 is low, voltage is applied between transparent electrodes 14, 18 of the touch panel 11 to make them function as a panel heater to heat the liquid crystal display panel 2. When temperature of the liquid crystal display panel 2 becomes high, application of voltage between the transparent electrodes 14, 18 of the touch panel 11 is switched from for the panel heater to for the touch panel. Delay of response speed at low temperature due to temperature dependency of viscosity of a liquid crystal composition in the liquid crystal display panel 2 can be prevented. Even at low temperature, response speed of the liquid crystal display panel 2 can be made quick. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a liquid crystal display device including a liquid crystal display panel and a touch panel.

  Conventionally, this type of liquid crystal display device has a liquid crystal display panel in which liquid crystal is interposed between the array substrate and the counter substrate, except for the array substrate of the liquid crystal display panel, the counter substrate, and the surrounding liquid crystal sealing opening. The liquid crystal sealing port is sealed with a sealing agent. As a display method of this liquid crystal display panel, for example, TN (Twisted Nematic) type, ST (Stock Time) type, GH (Guest Host) type, ECB (Electrically Controlled Birefringence) type, ferroelectric liquid crystal, etc. are used. ing. Further, as the sealant, for example, a thermosetting type curable by heat or an ultraviolet curable type acrylic or epoxy type adhesive curable by ultraviolet irradiation is used.

  Further, in the color type active matrix drive liquid crystal display panel, scanning lines and signal lines are provided in a grid pattern on an insulating substrate, and amorphous silicon (a-Si) is applied to the semiconductor layer corresponding to the intersections of these scanning lines and signal lines. A thin film transistor (TFT) is provided, and an array substrate is provided as an active matrix substrate in which pixel electrodes are electrically connected to the thin film transistor. The array substrate is provided with a counter substrate provided with a counter electrode, and the counter electrode of the counter substrate is provided on the color filter layer. Further, a liquid crystal layer is formed by sandwiching a liquid crystal composition between the array substrate and the counter substrate. Each of the array substrate and the counter substrate is sandwiched between polarizing plates, and is configured to display a color image as an optical shutter.

  There are various uses for this type of liquid crystal display panel, but the demand for in-vehicle monitors mounted on automobiles is increasing. Further, for this in-vehicle monitor, it is required to increase the performance under a low temperature environment, particularly the response speed. That is, when the temperature is low and the response speed of the in-vehicle monitor is slow, there is a risk that the in-vehicle monitor image may be blurred or invisible. This defect is due to the temperature dependence of the viscosity of the liquid crystal, and the liquid crystal cannot respond to changes in the applied voltage when the viscosity of the liquid crystal increases at low temperatures.

  Therefore, in order to solve this problem, a liquid crystal display panel is provided with a panel heater formed by disposing ITO (Indium Tin Oxide) as an electrode layer on the surface of a film made of PET (PolyEthylene Terephthalate). A configuration is known in which the liquid crystal display panel is rapidly heated and warmed by supplying the power to the panel heater so as to face the back surface of the liquid crystal display (see, for example, Patent Document 1).

On the other hand, as the above-mentioned in-vehicle monitor, as a means for improving the operability of the in-vehicle monitor, a touch panel having a coordinate input function is disposed so as to be opposed to the front surface of the liquid crystal display panel. In the touch panel, transparent electrodes are respectively formed on one main surface of the two substrates facing each other so that a current flows between the two substrates.
JP-A-8-83684

  However, in the liquid crystal display panel in which the touch panel is attached to the front surface of the liquid crystal display panel, the response speed of the liquid crystal becomes slow at a low temperature due to the temperature dependence of the viscosity of the liquid crystal as described above. There is a problem that the display quality is lowered.

  The present invention has been made in view of these points, and an object of the present invention is to provide a liquid crystal display device capable of improving display quality.

  The present invention includes a flat liquid crystal display panel having a pair of substrates and a liquid crystal interposed between the pair of substrates, and a heating means for heating the liquid crystal display panel, and is disposed to face the liquid crystal display panel. And a flat touch panel capable of inputting coordinates by sensing pressure.

  A flat touch panel that is arranged to face the liquid crystal display panel and can input coordinates by sensing pressure includes a heating unit. Therefore, by heating the liquid crystal display panel with the heating means at a low temperature, it is possible to prevent the response speed of the liquid crystal from slowing at a low temperature due to the temperature dependence of the viscosity of the liquid crystal of the liquid crystal display panel. Therefore, since the response speed of the liquid crystal can be increased even at low temperatures, the display quality can be improved.

  According to the present invention, since the touch panel disposed opposite to the liquid crystal display panel includes the heating unit, the liquid crystal response of the liquid crystal display panel is heated by heating the liquid crystal display panel with the heating unit at a low temperature. Since the speed can be prevented from slowing at low temperatures, the response speed of the liquid crystal can be increased even at low temperatures, and the display quality can be improved.

  The configuration of an embodiment of the liquid crystal display device of the present invention will be described below with reference to FIG.

  In FIG. 1, reference numeral 1 denotes a liquid crystal display (LCD) as a flat display device. The liquid crystal display device 1 has a coordinate input function and includes a liquid crystal display panel 2 as a liquid crystal cell capable of liquid crystal display. The liquid crystal display panel 2 is formed in a substantially rectangular flat plate size of, for example, 300 mm × 400 mm. The liquid crystal display panel 2 is an active matrix type liquid crystal display element using a thin film transistor (TFT) as a switching element. Further, the liquid crystal display panel 2 is a TFT-LCD whose display method is a TN (Twisted Nematic) mode.

  The liquid crystal display panel 2 includes a substantially rectangular flat plate array substrate 3 as an active matrix substrate. The array substrate 3 is an XGA (eXtended Graphics Array) type TFT array substrate. The array substrate 3 is provided on the upper surface, which is one main surface of the array substrate 3, so that scanning lines and signal lines as electrode wirings intersect each other. A plurality of pixels (not shown) are provided in each of the regions surrounded by the scanning lines and the signal lines. Here, the plurality of pixels are provided by 100 pixels along each of the vertical direction and the horizontal direction of the array substrate 3. Therefore, the plurality of pixels are provided on the upper surface of the array substrate 3 in total about 10,000 pixels.

  The plurality of pixels are provided in a matrix on the front surface of the array substrate 3, and each of the plurality of pixels is provided with a thin film transistor (not shown), a pixel electrode as a display electrode, and an auxiliary capacitor. . Further, an alignment film (not shown) is laminated on the upper surface of the array substrate 3 including the plurality of pixels. This alignment film is formed, for example, by applying AI-1051 (manufactured by JSR Corporation) as an alignment film material and then performing an alignment process by a rubbing method so that the alignment processing directions intersect at an angle of 90 °. ing.

  Furthermore, a substantially rectangular flat plate-like counter substrate 4 as a color filter substrate is disposed on the upper surface, which is one main surface of the array substrate 3, so as to face each other. The counter substrate 4 is attached to the array substrate 3 with the lower surface, which is one main surface of the counter substrate 4, facing the upper surface of the array substrate 3 in a planar shape. Here, the counter substrate 4 is configured by laminating a color filter layer on the lower surface of the counter substrate 4 and laminating a counter electrode on the color filter layer. Further, an alignment film (not shown) is laminated on the counter electrode. This alignment film is formed, for example, by applying AI-1051 (manufactured by JSR Corporation) as an alignment film material and then performing an alignment process by a rubbing method so that the alignment processing directions intersect at an angle of 90 °. ing.

  A peripheral portion between the upper surface of the array substrate 3 and the lower surface of the counter substrate 4 forms a sealing material 5 for forming a liquid crystal sealing region F at a predetermined interval in the space between the array substrate 3 and the counter substrate 4. Is attached and sealed. That is, the sealing material 5 is applied to the peripheral portion between the upper surface of the array substrate 3 and the lower surface of the counter substrate 4 and then thermally cured to seal between the array substrate 3 and the counter substrate 4. Yes.

  Further, in the liquid crystal sealing region F between the array substrate 3 and the counter substrate 4, for example, a liquid crystal composition (not shown) that is a liquid crystal made of nitrogen having a refractive index anisotropy (Δn) of 0.1 is injected. A liquid crystal layer 6 as a light modulation layer is formed by being sandwiched. The liquid crystal layer 6 is configured by sealing a liquid crystal composition interposed between the counter substrate 4 and the array substrate 3.

  The liquid crystal display panel 2 is electrically connected and attached with a temperature detection system 7 as a control means as a temperature detection means capable of detecting the temperature of the liquid crystal display panel 2. The temperature detection system 7 is a means for detecting the temperature of the liquid crystal display panel 2 and a heating means for heating the liquid crystal display panel 2.

  On the other hand, a substantially rectangular flat plate-shaped touch panel 11 smaller than the liquid crystal display panel 2 is attached to the upper surface of the liquid crystal display panel 2 in a state of being overlaid. The touch panel 11 is stacked on the liquid crystal display panel 2 in direct surface contact. Further, the touch panel 11 is laminated on the liquid crystal display panel 2 with the vertical and horizontal centers of the touch panel 11 being opposed to the vertical and horizontal centers of the liquid crystal display panel 2, respectively. ing. Further, the touch panel 11 senses the pressure caused by the pressing when an arbitrary position on the upper surface of the touch panel 11 is pressed, and enables coordinate input. In other words, the touch panel 11 has a direct input function that operates by directly contacting the liquid crystal display panel 2 and a heating function as a panel heater. That is, a device having a function capable of inputting directly from the liquid crystal display panel 2 is used for the touch panel 11. The touch panel 11 is attached to face the upper surface of the counter substrate 4 of the liquid crystal display panel 2. Furthermore, the touch panel 11 is provided at the center of each of the counter substrate 4 in the vertical direction and the horizontal direction.

  The touch panel 11 includes a lower electrode material 12 as a first substrate having a substantially rectangular flat plate shape. The lower electrode material 12 includes a glass substrate 13 which is a light-transmitting substrate as a substantially transparent rectangular flat plate-like insulating substrate. The glass substrate 13 has flexibility for input by elastic deformation of the touch panel 11. A transparent electrode 14 as a first electrode layer is laminated on the upper surface, which is one main surface of the glass substrate 13. This transparent electrode 14 is formed to a thickness of 0.01 μm or more and 0.1 μm or less by vacuum evaporation of transparent ITO, and has a resistance value of 5Ω or more and 100Ω or less, for example, 7Ω, and the entire upper surface of the glass substrate 13 is covered. Almost covered.

  Further, on the upper surface, which is one main surface of the transparent electrode 14, a plurality of dot spacers 15 having protrusions protruding from the surface of the transparent electrode 14 are provided in a matrix. The plurality of dot spacers 15 are provided on the transparent electrode 14 in a state of being spaced apart at equal intervals along each of the vertical direction and the horizontal direction of the glass substrate 13. Further, the plurality of dot spacers 15 are formed in a convex arc shape when viewed from the side, and are provided in a portion inside the outer peripheral edge excluding the outer peripheral edge of the transparent electrode 14.

  Specifically, these dot spacers 15 are formed only in a rectangular region spaced a predetermined distance inward from the peripheral edge of the transparent electrode. Further, the plurality of dot spacers 15 are formed in a dot shape with a diameter of 30 μm to 100 μm, for example, 50 μm, and a height of 1 μm to 15 μm, for example, 15 μm, with a constant interval of 0.1 mm to 10 mm. Are arranged via. The plurality of dot spacers 15 secures a gap between the transparent electrode 14 of the lower electrode material 12 and the transparent electrode 18 of the upper electrode material 16, and leads to the lower electrode material 12 or the upper electrode material 16. , And the separation between the lower electrode material 12 and the upper electrode material 16 after input is improved.

  Further, as these dot spacers 15, for example, acrylate resin such as melamine acrylate resin, urethane acrylate resin, epoxy acrylate resin, methacryl acrylate resin or acrylic acrylate resin, or transparent photo-curing resin such as polyvinyl alcohol resin is photoprocessed. Are formed in a number of fine dots. Here, these dot spacers 15 are formed by forming a large number of fine dots by a printing method using urethane-based transparent resin or the like, or spraying or applying a dispersion of particles composed of inorganic or organic substances. It can also be formed after drying.

  Further, an upper electrode material 16 as a second substrate having a substantially rectangular flat plate shape is attached to face the upper surface of the lower electrode material 12. The upper electrode material 16 is formed in a shape substantially equal to the lower electrode material 12. The upper electrode material 16 includes a glass substrate 17 that is a translucent substrate as a substantially transparent rectangular flat plate-like insulating substrate. The glass substrate 17 has flexibility for input by elastic deformation of the touch panel 11. A transparent electrode 18 as a second electrode layer is laminated and provided on the lower surface which is one main surface of the glass substrate 17. The transparent electrode 18 is formed by vacuum evaporation of transparent ITO and has a resistance value of 7Ω. The transparent electrode 18 covers the central portion of the front surface of the glass substrate 17 excluding the outer peripheral edge of the lower surface of the glass substrate 17. Yes.

  Therefore, the transparent electrode 18 and the transparent electrode 14 of the lower electrode material 12 constitute a heating mechanism 20 as a heating unit that causes the touch sensor to function as a panel heater. In the heating mechanism 20, a voltage is applied between the transparent electrodes 14 and 18 by the temperature detection system 7, whereby the touch panel 11 functions as a panel heater, and the liquid crystal display panel 2 is heated via the touch panel 11. Therefore, each of the transparent electrodes 14 and 18 constituting the heating mechanism 20 includes an electrode for causing the touch panel 11 to function as a panel heater for heating the liquid crystal display panel 2 and an electrode for causing the touch panel 11 to function as a panel sensor capable of inputting coordinates. It also serves as.

  Further, the peripheral portion between the upper surface of the transparent electrode 14 of the lower electrode material 12 and the lower surface of the glass substrate 17 of the upper electrode material 16 is formed by the dot spacers 15 and the upper electrode material 16 of the lower electrode material 12. An adhesive 19 is attached to form a predetermined gap with the transparent electrode 18. The adhesive 19 also functions as a spacer that maintains a gap between the lower electrode material 12 and the upper electrode material 16. The adhesive 19 is generally formed to a thickness of 10 μm or more and 200 μm or less by screen printing or the like. Then, the adhesive 19 is applied to the peripheral portion between the upper surface of the transparent electrode 14 of the lower electrode material 12 and the lower surface of the glass substrate 17 of the upper electrode material 16, and then thermally cured, so that the lower electrode material The space between the 12 transparent electrodes 14 and the glass substrate 17 of the upper electrode material 16 is sealed.

  A voltage is applied between the transparent electrode 14 of the lower electrode material 12 of the touch panel 11 and the transparent electrode 18 of the upper electrode material 16 by the temperature detection system 7 to heat the touch panel 11. Then, the liquid crystal display panel 2 is heated. Therefore, the temperature detection system 7 functions as a heating unit that heats the liquid crystal display panel 2. That is, the temperature detection system 7 detects the temperature of the liquid crystal display panel 2, and when the temperature of the liquid crystal display panel 2 is a preset temperature, for example, −5 ° C. or less, the transparent electrodes 14, A voltage of about 12 V, for example, is applied across 18 to heat the touch panel 11 so that the temperature of the liquid crystal display panel 2 becomes a preset temperature, for example, −5 ° C. or higher via the touch panel 11. Control. In addition, when the temperature of the liquid crystal display panel 2 is controlled to −5 ° C. or more, the temperature detection system 7 inputs the voltage applied between the transparent electrodes 14 and 18 of the touch panel 11 from 12V for heating. For example, the touch panel 11 is allowed to input coordinates.

  Further, the lower surface of the glass substrate 13 of the lower electrode material 12 of the touch panel 11 and the upper surface of the counter substrate 4 of the liquid crystal display panel 2 are configured to be bonded together with an adhesive 21 such as an acrylic adhesive. . That is, the adhesive 21 is fixed in a state where the lower surface of the glass substrate 13 of the lower electrode material 12 of the touch panel 11 and the upper surface of the counter substrate 4 of the liquid crystal display panel 2 are overlapped in a planar shape.

  Next, a method for manufacturing the liquid crystal display device according to the first embodiment will be described.

  First, the film forming process and the patterning process are repeated to produce an array substrate 3 in which each pixel on which a thin film transistor, a scanning line, a signal line, and a pixel electrode are formed is formed in a total of 10000 pixels.

  Next, after manufacturing the counter substrate 4 provided with the counter electrode on the color filter layer, the alignment film material is formed on each of the upper surface including each pixel of the array substrate 3 and the counter electrode of the counter substrate 4. For example, after applying AI-1051 (manufactured by JSR Corporation), the alignment treatment is performed by a rubbing method so that the alignment treatment directions intersect at an angle of 90 °.

  Thereafter, a spacer (not shown) is sandwiched between the alignment film of the array substrate 3 and the counter substrate 4, and a sealing material 5 is applied to the peripheral edge portion of the array substrate 3 and the counter substrate 4. The substrate 3 and the counter substrate 4 are bonded together.

  In this state, heat is applied to the sealing material 5 to cause thermosetting, and nitrogen having a refractive index anisotropy (Δn) of 0.1 from an injection port (not shown) between the array substrate 3 and the counter substrate 4. After injecting a liquid crystal composition that is a liquid crystal manufactured, the injection port is sealed to prepare the liquid crystal display panel 2.

  Then, the liquid crystal display device 1 with a touch panel capable of liquid crystal display and coordinate input is manufactured by attaching the touch panel 11 on the liquid crystal display panel 2 using an acrylic adhesive 21.

  Thereafter, the temperature detection system 7 is electrically connected to each of the liquid crystal display panel 2 and the touch panel 11 of the liquid crystal display device 1. The temperature detection system 7 enables the temperature of the liquid crystal display panel 2 to be detected, and a voltage of, for example, 12 V is applied between the transparent electrodes 14 and 18 of the touch panel 11 to heat the touch panel 11. The liquid crystal display panel 2 can be heated.

  Further, when the temperature of the liquid crystal display panel 2 is set to a preset temperature, for example, −5 ° C. or less, a voltage is applied between the transparent electrodes 14 and 18 of the touch panel 11, and the touch panel 11 is attached to the panel. The temperature detection system 7 is set so as to function as a heater and to control the temperature of the liquid crystal display panel 2 by heating it to a set temperature, for example, −5 ° C. or higher.

  When the temperature of the liquid crystal display panel 2 becomes −5 ° C. or lower and the temperature of the liquid crystal display panel 2 is detected by the temperature detection system 7, the transparent electrodes 14 and 18 of the touch panel 11 are detected by the temperature detection system 7. A voltage of 12 V is applied between them to rapidly increase the temperature of the liquid crystal display panel 2.

  Thereafter, when the temperature of the liquid crystal display panel 2 exceeds −5 ° C., application of a voltage between the transparent electrodes 14 and 18 of the touch panel 11 by the temperature detection system 7 causes the touch panel 11 to function as a panel heater. From 12V, the touch panel 11 can be switched to 2V that enables coordinate input.

  As described above, according to the embodiment, as shown in FIG. 2, when the temperature of the liquid crystal display panel 2 becomes lower than a predetermined temperature, for example, −5 ° C., the liquid crystal display panel 2 faces the array substrate 3. Due to the temperature dependence of the viscosity of the liquid crystal composition of the liquid crystal layer 6 sandwiched between the substrate 4 and the liquid crystal composition, the viscosity of the liquid crystal composition increases. Then, due to the viscosity of the liquid crystal composition becoming high, when the liquid crystal display panel 2 displays a liquid crystal, the response speed of the liquid crystal composition is slowed down. Will fall.

  Therefore, a touch panel 11 that functions as a panel heater is applied to the liquid crystal display panel 2 by applying a voltage between the transparent electrode 14 of the lower electrode material 12 and the transparent electrode 18 of the upper electrode material 16. . Further, a temperature detection system 7 is electrically connected to the liquid crystal display device 1 constituted by the liquid crystal display panel 2 and the touch panel 11 so that the temperature of the liquid crystal display panel 2 can be detected by the temperature detection system 7. In addition, the liquid crystal display panel 2 can be heated by applying a voltage between the transparent electrodes 14 and 18 of the touch panel 11 to function as a panel heater.

  As a result, when the temperature of the liquid crystal display panel 2 detected by the temperature detection system 7 becomes lower than a predetermined temperature, a voltage is applied between the transparent electrodes 14 and 18 of the touch panel 11 by the temperature detection system 7. The touch panel 11 is caused to function as a panel heater to heat the liquid crystal display panel 2 to a predetermined temperature. Further, when the temperature of the liquid crystal display panel 2 detected by the temperature detection system 7 becomes higher than a predetermined temperature, the voltage detection is applied between the transparent electrodes 14 and 18 of the touch panel 11 by the temperature detection system 7. Switching from application of a voltage to function as a panel heater to application of a voltage to function as the touch panel 11 is performed.

  Specifically, when the temperature detection system 7 detects that the temperature of the liquid crystal display panel 2 is −20 ° C., the temperature detection system 7 applies a voltage between the transparent electrodes 14 and 18 of the touch panel 11. Then, after operating as a panel heater, the temperature of the liquid crystal display panel 2 is detected as −5 ° C. by the temperature detection system 7 after 40 seconds, and the response speed of the liquid crystal display panel 2 is sufficiently fast and good. A display is obtained. Then, 40 seconds after the touch panel 11 is operated as a panel heater, the voltage applied between the transparent electrodes 14 and 18 of the touch panel 11 is changed from 12V to 2V to reduce the touch panel 11 to the coordinates. Allow input.

  Therefore, when the temperature of the liquid crystal display panel 2 is low, the liquid crystal display panel 2 is heated by causing the touch panel 11 to function as a panel heater, resulting in the temperature dependence of the viscosity of the liquid crystal composition of the liquid crystal display panel 2. The response speed of the liquid crystal composition can be prevented from slowing at low temperatures. Therefore, since the response speed of the liquid crystal display panel 2 can be increased even at low temperatures, the display quality of the liquid crystal display panel 2 can be improved. Further, since the liquid crystal display device 1 with a touch panel function can be made thinner than when the panel heater is superimposed on the liquid crystal display panel 2 and the touch panel 11, the thin liquid crystal display device 1 has a high response speed at a low temperature and a high display quality. it can.

  Further, since the touch panel 11 is directly contacted and laminated on the liquid crystal display panel 2, no air layer or the like is formed between the liquid crystal display panel 2 and the touch panel 11. Therefore, the liquid crystal display panel 2 can be efficiently heated by the heating mechanism 20 of the touch panel 11. Furthermore, the liquid crystal display panel 2 is heated by the heating mechanism 20 of the touch panel 11 so that the liquid crystal in the liquid crystal layer 6 of the liquid crystal display panel 2 is laminated on the liquid crystal display panel 2 by bringing the touch panel 11 into surface contact. The composition can be heated uniformly. Therefore, when the liquid crystal display panel 2 is heated by the touch panel 11, the liquid crystal display panel 2 can be heated uniformly without varying the response speed of the liquid crystal composition in the liquid crystal layer 6 of the liquid crystal display panel 2. The liquid crystal display panel 2 can be uniformly heated while ensuring the visibility of the liquid crystal display panel 2 without causing display unevenness or the like.

  In the above-described embodiment, the pair of transparent electrodes 14 and 18 of the touch panel 11 are laminated on the glass substrates 13 and 17 in order to ensure strength, but the transparent electrodes 14 and 18 are placed on the transparent resin film. The lower electrode material 12 and the upper electrode material 16 can also be formed by laminating them. Here, as the transparent resin film used for each of the lower electrode material 12 and the upper electrode material 16, since it is necessary to have flexibility for input, generally a polycarbonate system having a thickness of 75 μm or more and 250 μm or less, Examples thereof include engineering plastics such as polyamide or polyether ketone, resin films such as acrylic, polyethylene terephthalate or polybutylene terephthalate, and laminated films obtained by laminating these.

  Further, as the transparent electrodes 14 and 18 laminated on the transparent resin film, a metal film or metal oxide film having transparency and conductivity is formed by a method such as vacuum deposition, sputtering, or ion plating. The metal film used for the transparent electrodes 14 and 18 is gold, silver, copper, tin, nickel, aluminum, palladium, or the like. Furthermore, as a metal oxide film used for these transparent electrodes, for example, a metal oxide film such as ITO, tin oxide, indium oxide, antimony oxide, zinc oxide or cadmium oxide, or these metal oxides are mainly used. For example, a composite membrane.

  Alternatively, the adhesive 19 for bonding the lower electrode material 12 and the upper electrode material 16 to the touch panel 11 may be a double-sided tape or an adhesive.

  Further, when the temperature of the liquid crystal display panel 2 is −5 ° C. or lower, the temperature detection system 7 operates the touch panel 11 as a panel heater to heat the liquid crystal display panel 2 to a temperature of −5 ° C. or higher. However, the temperature at which heating of the liquid crystal display panel 2 is started can be set to any temperature other than −5 ° C. according to the performance of the liquid crystal display panel 2 and the required response speed.

  Further, the display method of the liquid crystal display panel 2 can be changed from TN (Twisted Nematic) mode, VA (Vertically Aligned) mode, IPS (In-Plane Switching) mode, OCB (Optically Compensated Bend) mode, STN (Super Twisted Nematic) mode. ) Mode, FLC (Ferroelectric Liquid Crystal) mode, homogeneous mode, and the like. Further, the liquid crystal display panel 2 can be applied to various liquid crystal display panels such as a transflective type and a reflective type.

  Furthermore, as the thin film transistor provided in each pixel on the array substrate 3 of the liquid crystal display panel 2, a top gate type, a bottom gate type or a coplanar type can be used correspondingly.

It is explanatory sectional drawing which shows one Embodiment of the liquid crystal display device of this invention. It is a table | surface which shows the relationship between the temperature of a liquid crystal display panel of a liquid crystal display device same as the above, and appearance.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Liquid crystal display device 2 Liquid crystal display panel 3 Array board | substrate as a board | substrate 4 Opposite board | substrate as a board | substrate 6 Liquid crystal layer as a liquid crystal 7 Temperature detection system as a temperature detection means
11 Touch panel
12 Lower electrode material as the first substrate
13 Glass substrate as an insulating substrate
14 Transparent electrode as the first electrode layer
16 Upper electrode material as second substrate
17 Glass substrate as an insulating substrate
18 Transparent electrode as the second electrode layer
20 Heating mechanism as a heating means

Claims (3)

A flat liquid crystal display panel including a pair of substrates and a liquid crystal interposed between the pair of substrates;
A liquid crystal display device comprising: a flat touch panel provided with heating means for heating the liquid crystal display panel and arranged to face the liquid crystal display panel and capable of inputting coordinates by sensing pressure. The touch panel
A first substrate having an insulating substrate and a first electrode layer provided on one main surface of the insulating substrate;
A second substrate having an insulating substrate and a second electrode layer provided on one main surface of the insulating substrate, the second electrode layer being disposed opposite to the first electrode layer; Prepared,
The heating means of the touch panel includes the first electrode layer and the second electrode layer, and a voltage is applied between the first electrode layer and the second electrode layer to heat the liquid crystal display panel. The liquid crystal display device according to claim 1. The liquid crystal display device according to claim 1, further comprising temperature detecting means capable of detecting the temperature of the liquid crystal display panel.

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