JP2006064916A - Liquid crystal display device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a liquid crystal display device in which lowering of responsiveness of a liquid crystal display element under low temperature is suppressed with a simple structure. <P>SOLUTION: The liquid crystal display device is equipped with the liquid crystal display element 1, a holding member 3 to hold the liquid crystal display element 1, a circuit substrate 4 disposed behind the liquid crystal display element 1 and electrically connected to the liquid crystal display element 1, a light emitting diode 6 illuminating the liquid crystal display element 1, a metal oxide film resistor 12 (a heating element) warming the liquid crystal display element 1, and a thermistor 11 (temperature detecting element) detecting temperature of the liquid crystal display element 1 or its vicinity, wherein the metal oxide film resistor 12 is arranged on the inside S surrounded by the holding member 3 and the circuit substrate 4. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a liquid crystal display device, and more particularly to a liquid crystal display device having a heating element for heating a liquid crystal display element.

In a liquid crystal display device using a liquid crystal display element, it is known that the response speed becomes slow when the temperature of the liquid crystal decreases. As an improvement of this point, for example, there is Patent Document 1 below. The liquid crystal display device described in Patent Document 1 is arranged so that a liquid crystal display body 2 (liquid crystal display element) is in thermal contact with an inner side of an outer frame 1 formed of a member having good thermal conductivity. A heat generating element (for example, a driving IC 3 or a power supply IC 4) related to driving of the liquid crystal display body 2 is thermally connected to the outer surface of the LCD. With this configuration, heat generated from the heat generating element is transmitted from the outer frame 1 to the liquid crystal display body 2, and the liquid crystal display body 2 is heated, so that the visibility and responsiveness of the liquid crystal display body 2 are reduced. It is not.
Japanese Utility Model Publication No. 6-8928

  However, in the liquid crystal display device disclosed in Patent Document 1, the outer frame 1 needs to be made of a material having good thermal conductivity such as iron, and a plurality of driving ICs 3 and power supply ICs 4 are attached using mounting stays 5 and screws 6. It must be fixed so as to be sandwiched between the outer frame 1 and the structure becomes complicated and the cost is increased. Further, since heat is transmitted from the peripheral edge of the liquid crystal display main body 2, the heat transmission is delayed in the central portion of the liquid crystal display main body 2. Further, since the heat generating elements are arranged outside the outer frame 1, heat easily escapes to the outside, and the loss is large.

  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 that can suppress a decrease in response of a liquid crystal display element at a low temperature with a simple structure.

  To achieve the above object, the present invention provides a liquid crystal display element, a holding member for holding the liquid crystal display element, a circuit board disposed behind the liquid crystal display element and electrically connected to the liquid crystal display element, A heating element that warms the liquid crystal display element and a temperature detection element that detects the temperature of the liquid crystal display element or its vicinity, and the heating element is disposed inside the holding member and the circuit board. is there.

  Further, a liquid crystal display element, a holding member that holds the liquid crystal display element, a circuit board that is disposed behind the liquid crystal display element and is electrically connected to the liquid crystal display element, and a light source that illuminates the liquid crystal display element And a heating element that warms the liquid crystal display element and a temperature detection element that detects the temperature of the liquid crystal display element or the vicinity thereof, and the heating element is disposed inside the holding member and the circuit board. Is.

  In addition, the temperature detection element is disposed inside the holding member and the circuit board.

  The heating element is a metal oxide film resistor.

  A liquid crystal display device can be obtained that has a simple structure and can suppress a decrease in the response of the liquid crystal display element at low temperatures.

  Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. 1 and 2 are cross-sectional views of the liquid crystal display device. FIG. 2 shows a longitudinal section in a direction perpendicular to FIG.

  The liquid crystal display device includes a rectangular liquid crystal display element 1 in which liquid crystal molecules are sealed between two glass substrates, and a smoke-like polarizing film is bonded to each glass substrate, and the back side of the liquid crystal display element 1. A light diffusing plate 2 that is disposed, a liquid crystal display element 1 and a holding member 3 that holds the light diffusing plate 2, and a hard member that is disposed behind the liquid crystal display element 1 and electrically connected to the liquid crystal display element 1 Circuit board 4, a metal holding frame 5 for fixing the liquid crystal display element 1 and the holding member 3 to the circuit board 4, and a light source mounted on the circuit board 4 to illuminate the liquid crystal display element 1 from behind. A light emitting diode 6 is provided.

  The holding member 3 is made of white synthetic resin, and includes a peripheral wall 7, a mounting portion 8 on which the liquid crystal display element 1 and the diffusion plate 2 are mounted, and a reflecting wall extending from the mounting portion 8 toward the light emitting diode 6. 9. The peripheral wall 7 is configured so that the entire periphery thereof is substantially in contact with the circuit board 4. The reflection wall 9 reflects the light from the light emitting diode 6 and guides it to the diffusion plate 2 side. For example, when the light emitting diode 6 that emits white light is turned on, there is a lot of light that directly shines on the diffusion plate 2, but there is also light that is reflected by the reflection wall 9 and guided to the diffusion plate 2 side. Thus, the surface of the liquid crystal display element 1 excluding the display unit (not shown) is illuminated almost uniformly. Note that the reflecting wall 9 and the diffusion plate 2 may be omitted if satisfactory illumination can be obtained.

  Foot portions 10 are provided at a plurality of locations around the presser frame 5, and the distal ends thereof are inserted into holes (not shown) provided in the circuit board 4 and bent. By doing so, the liquid crystal display element 1, the holding member 3, and the like are attached and fixed to the circuit board 4. Although not shown, the liquid crystal display element 1 and the circuit board 4 are electrically connected using a metal terminal or a flexible printed board. Further, without using the presser frame 5, an engaging portion is provided on the lower end side (circuit board 4 side) of the holding member 3 so that the holding member 3 holding the liquid crystal display element 1 is hooked to the circuit board 4. Also good.

  In addition to the light emitting diode 6 that illuminates the liquid crystal display element 1 as described above, the circuit board 4 includes control means such as a microcomputer, a drive circuit, and a power supply circuit that perform the display operation on the liquid crystal display element 1 (not shown). Has been implemented. Further, a thermistor 11 as a temperature detecting element for detecting the temperature of the liquid crystal display element 1 or its vicinity and a metal oxide film resistor 12 as a heating element for heating the liquid crystal display element 1 from the back are mounted on the circuit board 4. is there. The metal oxide film resistor 12 and the thermistor 11 are formed on the circuit board 4 in the interior S surrounded by the holding member 3 and the circuit board 4 that are generated by making the peripheral wall 7 of the holding member 3 substantially contact the circuit board 4. To be implemented.

  The metal oxide film resistor 12 is attached and fixed by soldering a lead 13 to the circuit board 4 corresponding to substantially the center of the liquid crystal display element 1. A plurality of metal oxide film resistors 12 may be provided. Although not shown, the circuit board 4 is provided with a control means for turning on / off the power supply to the metal oxide film resistor 12 based on the temperature detected by the thermistor 11.

  Next, the heat generating action of the metal oxide film resistor 12 will be described. When the temperature of the internal S detected by the thermistor 11 becomes a low temperature of, for example, 0 ° C. or less, energization to the metal oxide film resistor 12 is turned on. As a result, the liquid crystal display element 1 is warmed by heat generated from the metal oxide film resistor 12. And when it detects that the temperature of the inside S exceeded 10 degreeC, for example, electricity supply to the metal oxide film resistance 12 will be turned off.

  In this way, the thermistor 11 and the metal oxide film resistor 12 are arranged in the interior S surrounded by the holding member 3 and the circuit board 4 so that the interior S does not fall below a predetermined (target) temperature. Since the control is performed, it is possible to prevent the response of the liquid crystal display element 1 from being lowered even when the liquid crystal display device is used in a low temperature environment.

  Further, by disposing the thermistor 11 and the metal oxide film resistor 12 on the circuit board 4 on which the control means for driving the liquid crystal display element 1 and the light emitting diode 6 are mounted, it is not necessary to use separate members and the structure is simple. Cost is also low. Further, by disposing the thermistor 11 and the metal oxide film resistor 12 in the interior S surrounded (closed) by the holding member 3 and the circuit board 4, the liquid crystal display element 1 can be efficiently manufactured with reduced heat loss. Be warmed up.

  Further, by disposing the metal oxide film resistor 12 at a position corresponding to substantially the center of the liquid crystal display element 1, the entire liquid crystal display element 1 can be warmed in a shorter time. Further, the heating element for heating the liquid crystal display element 1 may not be the metal oxide film resistor 12, but the metal oxide film resistor 12 is small in size and can be easily fixed to the circuit board 4 and is inexpensive.

  In addition, this invention is not limited to the said embodiment, For example, the thermistor 11 and the metal oxide film resistance 12 do not necessarily need to be arrange | positioned on the circuit board 4 (for example, the thermistor 11 is the liquid crystal display element 1 or a diffusion plate). However, mounting on the circuit board 4 is simpler in structure and lower in cost as described above. Further, the thermistor 11 may be arranged outside the inner S surrounded by the holding member 3 and the circuit board 4, but the arrangement of the thermistor 11 in the inner S detects the temperature of the liquid crystal display element 1 suitable for the use state. Thus, the liquid crystal display element 1 can be efficiently warmed.

  Further, by configuring the liquid crystal display device 1 to be a liquid crystal display device using the transmissive liquid crystal display device 1 that illuminates with the light emitting diode 6 from behind, the display unit can be viewed regardless of day or night. However, a liquid crystal display device that does not use a light source that illuminates the liquid crystal display element 1 from behind may be used, and even in this case, the same effect can be obtained.

1 is a cross-sectional view of a liquid crystal display device showing an embodiment of the present invention. Sectional drawing of the longitudinal direction of the liquid crystal display device.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Liquid crystal display element 3 Holding member 4 Circuit board 6 Light emitting diode (light source)
11 Thermistor (temperature detection element)
12 Metal oxide film resistance (heating element)
S inside

Claims (4)

  A liquid crystal display element, a holding member for holding the liquid crystal display element, a circuit board disposed behind the liquid crystal display element and electrically connected to the liquid crystal display element, a heating element for heating the liquid crystal display element, A liquid crystal display device comprising: the liquid crystal display element or a temperature detecting element for detecting a temperature in the vicinity thereof, wherein the heating element is disposed inside the holding member and the circuit board.   A liquid crystal display element, a holding member for holding the liquid crystal display element, a circuit board disposed behind the liquid crystal display element and electrically connected to the liquid crystal display element, a light source for illuminating the liquid crystal display element, A heating element that warms the liquid crystal display element; and a temperature detection element that detects the temperature of the liquid crystal display element or the vicinity thereof; and the heating element is disposed inside the holding member and the circuit board. A characteristic liquid crystal display device.   3. The liquid crystal display device according to claim 1, wherein the temperature detection element is disposed inside the holding member and the circuit board.   The liquid crystal display device according to any one of claims 1 to 3, wherein the heating element is a metal oxide film resistor.

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