JPH0350591A - Liquid crystal display device - Google Patents

Abstract

PURPOSE:To nearly eliminate an irregularity in coloring due to the temperature difference of a liquid crystal display surface by installing a heat radiation member which has high heat conductivity in contact with a fluorescent tube and a frame. CONSTITUTION:The heat radiation member 15 with the high heat conductivity has one end part in direct contract with the periphery of the fluorescent tube 13 and the other end part sandwiched between a backlighting photoconductive plate 12 and a frame 14 installed behind the backlighting photoconductive plate 12. The majority of heat radiated from the fluorescent tube 13 is conducted to the heat radiation member 15 in contact with the fluorescent tube 13 and radiated. The one end part of the heat radiation member 15 contacts with the frame 14, surface to surface, and heat from it is radiated selectively. Further, heat which is conducted to the backlighting photoconductive plate 12 is also conducted to the frame 14 by sandwiching the heat radiation member 15 between the plate 12 and frame 14. Consequently, the irregularity in coloring due to the temperature difference of the liquid crystal display surface is nearly eliminat ed.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a liquid crystal display device equipped with an edge-illuminated backlight.

2. Description of the Related Art In recent years, many liquid crystal display devices used in word processors and the like are equipped with a backlight. Furthermore, with the demand for smaller and thinner devices, in this backlight device, the fluorescent tubes are placed outside the liquid crystal display range, and light is introduced from the end face of the light guide plate. (3) Edge-illuminated backlights are becoming more and more popular.

A liquid crystal display device equipped with a conventional edge-illuminated backlight will be described below.

FIGS. 2a and 2b are a sectional view and a configuration diagram of a conventional liquid crystal display device equipped with an edge-illuminated backlight, in which 21 is a transmissive liquid crystal display panel, 22 is an edge-illuminated backlight light guide plate, 23 indicates a fluorescent tube.

By lighting the fluorescent tubes 23, the light enters the light guide plate from the end face of the backlight light guide plate 22, travels forward while repeating refraction, and can evenly illuminate the display surface of the transmissive liquid crystal display panel 21. .

Problems to be Solved by the Invention However, with the above configuration, the heat generated by the fluorescent tubes is transmitted to the ends of the transmissive liquid crystal display panel, and the temperature of the portions near the fluorescent tubes rises. This had the problem of causing unevenness in the color development of the display. Conventionally, in order to eliminate this unevenness, it was necessary to increase the distance between the fluorescent tube and the display surface of the transmissive liquid crystal display panel to a point where the heat from the fluorescent tube would not affect it. The problem was that it could not be done.

The present invention solves the above-mentioned problems by transmitting and radiating the heat generated by the fluorescent tube in a direction that does not affect the liquid crystal display, without increasing the size of the device. An object of the present invention is to provide a liquid crystal display device that can prevent color unevenness of liquid crystal caused by temperature differences.

Means for Solving the Problem In order to achieve this object, the liquid crystal display device of the present invention has one end that is in direct contact with the periphery of the fluorescent tube, and the other end that is in close contact with the backlight light guide plate and the back surface of the backlight light guide plate. It consists of a heat dissipating member that is sandwiched between the frames installed in the frame, and a heat insulating sheet that is installed between the fluorescent tubes and the transmissive liquid crystal display panel.

Function: With this configuration, the heat generated from the fluorescent tube is transmitted to the large frame on the back side of the light guide plate by the heat radiating member and is radiated. Furthermore, by blocking the transfer of heat to the transmissive liquid crystal display panel with a heat insulating sheet, the temperature rise at the fluorescent tube side end of the transmissive liquid crystal display panel can be suppressed, and color unevenness in the liquid crystal display can be prevented. An embodiment of the present invention will be described below with reference to the drawings. FIGS. 1a and 1b show a liquid crystal display device according to an embodiment of the present invention. In the first part, 11 is a transmissive liquid crystal display panel, 12 is a backlight light guide plate, 13 is a fluorescent tube, 14 is a frame, 15 is a heat dissipation member, 16 is a heat insulating sheet, and 17° and 18 are outer cabinets.

The operation of the liquid crystal display device of this embodiment configured as described above will be described below. First, most of the heat generated from the fluorescent tube 13 when the fluorescent tube 13 is turned on is transferred to the heat dissipation member 16 made of highly thermally conductive silicone rubber that is in close contact with the fluorescent tube 13. One end of the heat dissipation member 16 is connected to the backlight light guide plate 12
Since it is in surface contact with a frame 14 having a high heat dissipation effect on the back side, heat is selectively transferred and dissipated in the direction of this frame 14. Furthermore, the heat transferred to the backlight light guide plate 12 is also quickly transferred to the frame 14 by inserting the heat dissipating member 15 between the frame 14 and the frame 14.

In addition, a heat insulating unit 16 and a transmissive liquid crystal display panel 1
Cut off heat conduction to the end of 1.

As described above, according to this embodiment, a heat dissipating member made of highly thermally conductive silicone rubber is installed in close contact with the fluorescent tube and the frame, and a heat insulating sheet is installed between the fluorescent tube and the transmissive liquid crystal display panel. , the heat generated by the fluorescent tube can be quickly conducted and dissipated to the frame on the back of the light guide plate, preventing heat from flowing into the edges of the transmissive liquid crystal display panel, and preventing uneven coloring due to temperature differences on the liquid crystal display surface. can be almost eliminated.

In this embodiment, the end face of the heat radiating member 16 is sandwiched between the backlight light guide plate 12 and the frame 14, and the heat is radiated to the frame 14, but the frame 14 may be any other structure with a large heat capacity. . For example, in the case of a configuration in which the backlight light guide plate 12 is held by the outer cabinet 17 and 18 of the transmissive liquid crystal display panel 11 without the frame 14, the heat dissipation member 16 may be sandwiched between the outer cabinet 17 and the backlight light guide plate 12. Alternatively, the structure may be such that the heat is conducted and radiated to the outer cabinet 17.

Effects of the Invention The present invention has a heat dissipating member made of highly thermally conductive silicone rubber that is installed in close contact with the fluorescent tube and the frame, and a heat insulating sheet is installed between the fluorescent tube and the transmissive liquid crystal display panel. The generated heat can be quickly conducted and dissipated to the frame on the back of the light guide plate, preventing heat from flowing into the edges of the transmissive liquid crystal display panel, and almost eliminating uneven coloring due to temperature differences on the liquid crystal display surface. . Furthermore, since the influence of heat is eliminated, the fluorescent tube can be installed closer to the transmissive liquid crystal display panel, making it possible to miniaturize the device and realize a liquid crystal display device with excellent effects. It is something.

[Brief explanation of drawings]

1A and 1B are a sectional view and a configuration diagram of a liquid crystal display device according to an embodiment of the present invention, and FIGS. 2A and 2B are a sectional view and a configuration diagram of a conventional liquid crystal display device. 11... Transmissive liquid crystal display panel, 12...
... Backlight light guide plate, 13 ... Fluorescent tube, 1
4... Frame, 16... Heat dissipation member,
16・River・Insulation sheet, 17・・Outer cabinet.

Claims (3)

[Claims] (1) A transmissive liquid crystal display panel, an edge-type backlight light guide plate provided on the back surface of the transmissive liquid crystal display panel, and a fluorescent tube installed adjacent to the end surface of the backlight light guide plate. and a frame that holds the backlight light guide plate and is provided on the back surface of the backlight guide plate, one end of which is in direct contact with the periphery of the fluorescent tube, and the other end of which is placed between the backlight light guide plate and the frame. 1. A liquid crystal display device comprising a highly thermally conductive heat dissipating member which is sandwiched between the two and is in close contact with the two. (2) The liquid crystal display device according to claim 1, wherein the heat dissipating member is made of heat dissipating silicone rubber, which is a material with high thermal conductivity and high electrical insulation. (3) The liquid crystal display device according to claim 1, characterized in that a heat insulating sheet made of a material with low thermal conductivity is provided between the fluorescent tube and the transmission type liquid crystal display panel.