JPH0815674A - Liquid crystal display device - Google Patents

Abstract

PURPOSE:To prevent a malfunction of a drive element due to heat and to efficiently radiate the heat of the drive element by providing a heat transmission material for transmitting the heat generated by the drive element of a liquid crystal element to a shield case. CONSTITUTION:A liquid crystal display device is constituted of the liquid crystal element, the shield case 2 and the drive element 3. The drive element 3 constitutes a row driver and a column driver, and is connected to a terminal part of an electrode formed on a lower substrate 11, and supplies various signals to the liquid crystal element. The shield case 2 is provided with an opening exposing the display area of the liquid crystal display device to shield and cover the liquid crystal element. A recessed part 21 is formed on a part confronted with the drive element 3 of the shield case 2, and the soft heat transmission material 31 made of heat radiating silicone, etc., is arranged below the recessed part 21. Thus, the heat generated by the drive element 3 is transmitted to the shield case 2 through the heat transmission material 31 to be radiated over the whole shield case 2.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid crystal display device, and more particularly to a liquid crystal display device in which the heat dissipation efficiency of a drive circuit for a liquid crystal display element is improved.

[0002]

2. Description of the Related Art A driving circuit for a liquid crystal display device (driving LS
I) is generally a chip-on-glass (CO
G) system or TAB system is connected to the liquid crystal display element.

[0003]

In the drive LSI for a liquid crystal display element, the structure of its internal circuit has become complicated as the number of gradations and the number of pixels of the liquid crystal display element have increased, and the amount of heat generated is also large. It has increased. However, the conventional drive LSI does not take any heat dissipation measures. Therefore, the driving LSI may be overheated, which may cause a malfunction.

In order to cool the driving LSI, a normal L
Although mounting a heat sink for SI on a drive LSI is also partially performed, it is not preferable because it hinders flattening of the entire liquid crystal display element and increases cost.

The present invention has been made in view of the above circumstances, and an object thereof is to provide a liquid crystal display device capable of preventing a malfunction of a driving element due to heat. Another object of the present invention is to provide a liquid crystal display device capable of efficiently radiating the heat of a driving element. Another object of the present invention is to provide a liquid crystal display device which can efficiently dissipate the heat of the driving element of the present invention, can be made thin, and can be manufactured at low cost.

[0006]

In order to achieve the above object, a liquid crystal display device of the present invention includes a case, a liquid crystal display element arranged in the case, and a liquid crystal display connected to the liquid crystal display element. A heat dissipating member for the drive element, the drive element for driving the element, and a heat transfer material disposed between the drive element and the case for transmitting heat generated by the drive element to the case. It is characterized by being used as.

The heat transfer material is made of, for example, silicon for heat dissipation. The case is, for example, a shield case of the liquid crystal display element. The case is provided with a recess, and the heat transfer material connects the drive element and the recess. The liquid crystal display element includes a glass substrate, and the driving element is arranged on the glass substrate. The drive element is fixed to a tape on which a wiring connected to the liquid crystal display element is formed.

[0008]

According to the above construction, the heat generated by the driving element is
The heat is transferred to the case via the heat transfer material made of heat radiating silicon, and is radiated through the case. Therefore, the drive circuit can dissipate heat without connecting a dedicated heat sink to the drive circuit. Since no dedicated heat sink is used, the liquid crystal display device can be made thin and the cost can be kept low. When the gap between the drive element and the case is wide, a recess may be formed in the case, and the heat transfer material may be arranged between the recess and the drive element. Further, the driving element may be, for example, a COG type which is directly arranged on the glass substrate of the liquid crystal display element, or a TAB type which is fixed to a tape on which printed wiring and the like are formed.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A liquid crystal display device according to embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is an exploded perspective view showing the configuration of the liquid crystal display device of this embodiment, and FIG. 2 is an enlarged cross-sectional view of a connecting portion between a drive element and a case. As shown in FIG. 1, the liquid crystal display device of this embodiment includes a liquid crystal display element 1,
Liquid crystal display element 1 shield case 2 and liquid crystal display element 1
Drive element (drive LSI) 3.

As is generally known, the liquid crystal display element 1 is formed by bonding counter substrates 11 and 12 each having electrodes formed thereon with a sealing material, and filling a liquid crystal between the substrates 11 and 12. Has been done. Both the substrates 11 and 12 are made of glass or the like, the lower substrate 11 is formed to be larger than the upper substrate 12, and the driving element 3 is directly arranged on the periphery thereof.

When the liquid crystal display element 1 is a TFT liquid crystal display element, the driving element 3 constitutes a row driver, a column driver, etc., and is formed on the lower substrate 11 (generally a TFT substrate on which TFTs and pixel electrodes are formed). Is connected to the terminal portion of the electrode and supplies various signals for driving the liquid crystal display element 1 to the liquid crystal display element.

The shield case 2 has an opening for exposing the display area of the liquid crystal display element 1, and shields and covers the liquid crystal display element 1. The shield case 2 is made of, for example, a heat conductive material such as aluminum that has been subjected to an insulation treatment.

A recess 21 is formed in a portion of the shield case 2 facing the drive element 3 by press working or the like as shown in a cross section in FIG. A soft heat transfer material (heat conductor) 31 made of silicone for heat dissipation is arranged under each recess 21. At the stage of mounting the shield case 2 on the liquid crystal display element 1, the heat transfer material 31 is pressed from both sides between the recess 21 and the driving element 3, and is brought into close contact with the recess 21 and the driving element 3, so that the driving element 3 is removed. A bridge that transfers heat to the shield case 2 is formed.

In the liquid crystal display device having such a structure, the heat generated in the driving element 3 is transferred to the shield case 2 through the heat transfer material 31, and is radiated by the entire shield case 2. Therefore, the heat generated in the drive element 3 is efficiently dissipated, the drive element 3 does not overheat, and there is no risk of malfunction due to overheating. Further, since it is not necessary to dispose a dedicated heat sink or the like, the liquid crystal display device as a whole can be made small and thin and can be manufactured at low cost.

The recess 21 is formed in the shield case 2 in order to reduce the distance between the shield case 2 and the driving element 3 in consideration of the thickness of the upper substrate 12 of the liquid crystal display element 1. For example, when an extremely thin member such as a film substrate is used as the upper substrate 12, it is not necessary to provide the recess 21.

In the above embodiment, the liquid crystal display device having the COG (chip on glass) type drive element 3 in which the drive element 3 is directly arranged on the glass substrate 11 has been described, but the present invention is limited to the above embodiment. Not done. The present invention is, for example, as shown in FIG.
The present invention can be similarly applied to a liquid crystal display device provided with a (Tape Automated Bonding) type driving element 33.

The liquid crystal display element is not limited to an active matrix type using a TFT or the like as an active element, but may be a simple matrix type. Heat transfer material 3
It is desirable that 1 is an insulating material having high thermal conductivity, and the drive element may be fixed to the shield case by using a thermally conductive adhesive material or the like. The shield case 2 is not limited to one that shields the liquid crystal display element 1, and may be any case as long as it has excellent thermal conductivity.

[0018]

As described above, according to the liquid crystal display device of the present invention, the heat generated by the driving element can be efficiently dissipated and the malfunction of the driving element can be prevented. Further, since it is not necessary to dispose a dedicated heat sink or the like, the liquid crystal display device as a whole can be made small and thin, and the cost is low.

[Brief description of drawings]

FIG. 1 is an exploded perspective view of a liquid crystal display device according to an embodiment of the present invention.

FIG. 2 is an enlarged cross-sectional view of a portion where a drive element and a shield case face each other.

FIG. 3 is an exploded perspective view of a liquid crystal display device when a TAB type LSI is used as a driving element.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Liquid crystal display element, 2 ... Shield case, 3 ... Driving element, 11 ... Lower substrate, 12 ... Upper substrate, 21 ... Recessed part, 31 ... Heat transfer material (Heat dissipation silicone), 33 ... TA
B type drive element

Claims (6)

[Claims] 1. A case made of a thermally conductive material, a liquid crystal display element arranged in the case, a drive element connected to the liquid crystal display element and for driving the liquid crystal display element, A liquid crystal display characterized by comprising a heat transfer material disposed between the drive element and the case and transmitting heat generated by the drive element to the case, wherein the case is used as a heat dissipation member of the drive element. apparatus. 2. The liquid crystal display device according to claim 1, wherein the heat transfer material is made of heat dissipation silicon. 3. The liquid crystal display device according to claim 1, wherein the case comprises a shield case of the liquid crystal display element. 4. The liquid crystal display device according to claim 1, wherein the case has a recess, and the heat transfer material connects the drive element to the recess. 5. The liquid crystal display device according to claim 1, wherein the liquid crystal display element includes a glass substrate, and the driving element is arranged on the glass substrate. 6. The liquid crystal display device according to claim 1, wherein the drive element is fixed to a tape on which wirings connected to the liquid crystal display element are formed. .