JPH032897Y2 - - Google Patents

Description

[Detailed Description of the Invention] This invention relates to a liquid crystal display device that irradiates a liquid crystal cell with light condensed by a reflector and displays a display using the light that passes through the cell.

<Prior Art> For example, as shown in FIG. 1, a liquid crystal display has a display surface 12 on the front surface of a case 11 having a substantially rectangular parallelepiped shape, and has a display section 13 that digitally displays, for example, the speed of a car, and an analog display section 12. A display section 14 for displaying information is provided.

As shown in FIG. 2, in this display, a liquid crystal cell 15 is placed in contact with the inner surface of the front plate of a case 11, a heater 16 is provided on the back side of the liquid crystal cell 15, and a diffuser plate 17 is arranged behind the heater 16. has been done. A semi-cylindrical reflection plate 18 is provided behind the reflection plate 18, and the opening periphery of the reflection plate 18 almost coincides with the periphery of the diffusion plate 17, and these liquid crystal cells 15
A shielding space from the outside is formed inside the reflecting plate 18. A substrate 19 is disposed behind the reflection plate 18 , and an elastic conductive connector 21 is attached to the substrate 19 . One end of the connector 21 is in elastic contact with the electrode portion 15 a of the liquid crystal cell 15 .
is electrically connected to the drive circuit on the substrate 19. The peripheral edge of the substrate 19 is in contact with the peripheral rib of the case 11 and fixed with screws 22 and nuts 23. An incandescent bulb 26 is positioned in a shielded space formed by the reflector 18 and the liquid crystal cell 15 through a hole 24 formed in the substrate 19 and a hole 25 formed in the reflector 18 .

The direct light from the incandescent bulb 26 and the reflected light by the reflector plate 18 are condensed, and then pass through the diffuser plate 17 and enter the liquid crystal cell 15 side. The display on the liquid crystal cell 15 is visually recognized by viewing the light passing through the liquid crystal cell 15 from the outside. The responsiveness of the liquid crystal cell 15 deteriorates as the temperature decreases. Therefore, when the temperature falls below a certain level, the heater 16 is energized to warm the liquid crystal cell 15 so that correct display can be performed. Diffusion plate 17
is constructed of, for example, a transparent resin plate coated with white paint, and has the effect of diffusing the light from the incandescent bulb 26 and making it incident on the liquid crystal cell 15, thereby eliminating uneven brightness. While the incandescent bulb 26 emits light, it also dissipates considerable heat. For this reason, heat may be trapped within the shielding body, resulting in a considerable high temperature.

For this reason, conventionally, as shown in FIG.
Improve the heat dissipation of the reflector 18, or
As shown in FIG. B, heat dissipation holes 28 were formed in the reflection plate 18, and internal heat was radiated to the outside through the heat dissipation holes 28.

In this manner, in the past, heat dissipation measures were taken for the reflector plate 18 to prevent abnormal heating by the incandescent bulbs 26, and on the other hand, the heater 16 was provided as a measure against the low temperature of the liquid crystal cell 15.

<Structure of the device> The purpose of this device is to use the heat of an incandescent bulb to heat the liquid crystal cell at low temperatures, thereby providing heat dissipation measures at high temperatures and heat retention measures at low temperatures with a relatively simple structure. An object of the present invention is to provide a liquid crystal display device in which both of the following steps can be performed by the same means.

According to this idea, an opening/closing plate is installed near the heat radiation hole of the reflector, and the opening/closing plate opens the nearby heat radiation hole when the temperature exceeds a predetermined temperature, but closes the heat radiation hole when the temperature falls below a predetermined temperature. Consists of the body.

<Example> FIG. 4 shows an exploded view of an example of a liquid crystal display according to this invention, and parts corresponding to those in FIG. 2 are given the same reference numerals. In this example, a heat dissipation hole 28 is provided in the reflection plate 18, and one end of the opening/closing plate 29 is attached to the outer peripheral surface in the figure near the heat dissipation hole 28. The opening/closing plate 29 is a temperature sensitive body whose shape changes depending on the temperature, and is made of, for example, a so-called shape memory alloy, a bimetal, or the like. When the temperature is below a predetermined temperature, the opening/closing plate 29 closes the heat dissipation hole 28 as shown in FIG. The temperature characteristics of the temperature sensitive shape are selected so that the heat dissipation holes 28 are in an open state and the response characteristics of the liquid crystal cell are enhanced. In FIG. 4, the heater 16 in FIG. 2 is omitted.

With this structure, when the temperature of the reflecting plate 18 is below a predetermined value, the opening/closing plate 29 closes the heat radiation hole 28 as shown in FIG. reflector 18 and liquid crystal cell 15
The liquid crystal cell 15 is trapped in the shield formed by the above, and its internal temperature rises, heating the liquid crystal cell 15 and increasing the response characteristics of the liquid crystal cell 15.

On the other hand, when the temperature of the shielded space inside the reflector 18 increases, and therefore the temperature of the reflector 18 increases, the temperature of the opening/closing plate 29 also increases, and when this temperature exceeds a predetermined value, it deforms as shown in FIG. There is no fear that the heat dissipation hole 28 opens and the heat within the shielded space of the reflector plate 18 escapes to the outside, causing the interior of the reflector plate 18 to become abnormally high temperature.

As described above, in the liquid crystal display according to this invention, the heat of the incandescent bulb 26 can be used to keep the liquid crystal cell 15 warm, and when the temperature becomes too high, the heat is automatically dissipated from the heat radiation hole 28. will not be released to the outside and will not be abnormally heated. Therefore, the conventional heater 16 can be omitted, the number of parts is reduced accordingly, and special equipment such as a sensor for temperature adjustment is not required, making it possible to construct the device at low cost. In addition, the structure is extremely simple and assembly is easy, and by selecting the material for the opening/closing plate 29, the opening/closing temperature for the heat dissipation hole 28 can be set arbitrarily.

This idea requires complicated temperature detection to control not only liquid crystal displays but also other displays using incandescent bulbs, as well as heating elements inside the shield, to maintain the inside of the shield at a nearly constant temperature. It can be easily configured without providing any means or temperature adjustment means.

[Brief explanation of the drawing]

Fig. 1 is a perspective view showing a part of an example of a liquid crystal display, Fig. 2 is an exploded view showing a conventional liquid crystal display, Fig. 3 is a perspective view showing a conventional reflector, and Fig. 4 is a perspective view of a conventional liquid crystal display. FIG. 5 is an exploded view showing an example of the liquid crystal display according to the invention, and is a diagram showing a state in which the opening/closing plate has holes for heat radiation. 11: Case, 15: Liquid crystal cell, 17: Diffusion plate, 18: Reflection plate, 19: Substrate, 21: Elastic conductive connector, 26: Incandescent bulb, 28: Heat radiation hole,
29: Opening/closing plate.

Claims (1)

[Scope of utility model registration request] In a liquid crystal display in which light from an incandescent bulb is focused by a reflector plate and irradiated onto a display liquid crystal cell, and display is performed using the transmitted light, a shielding member whose inside is shielded from the outside by the liquid crystal cell and the reflector plate. is configured,
The incandescent bulb is placed inside the shield, a heat radiation hole is formed in the reflective plate, and a switch plate that deforms due to temperature changes is installed near the heat release hole, and the switch plate deforms when the temperature is below a predetermined temperature. A liquid crystal display comprising a temperature sensitive body selected to close the heat dissipation hole and open the heat dissipation hole at a temperature higher than a predetermined temperature to improve response characteristics of the liquid crystal cell.