JPS58200281A - Liquid crystal display - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a liquid crystal display device with improved illumination of a liquid crystal display element.

Display devices using liquid crystal display elements are widely used in calculators, wristwatches, personal combiators, etc. However, unlike light-emitting diodes, they do not emit light on their own, so a lighting structure is essential for liquid crystal display devices. It is said that For this reason, in the conventional device for this purpose, as shown in FIG. 1, a light source 3 such as a small lamp is installed near the surface of a liquid crystal display element 20 supported on a substrate 1, and this light source 3 is turned on to display a liquid crystal display. The surface of the element 2 is illuminated.

4 is a transparent protection plate.

However, in this configuration, since the light source 3 must be placed near the element 2, the heat emitted from the light source 3 tends to affect the element 2, and there is a possibility that the performance of the element 2 may deteriorate. Further, the heat of the light source may even affect the substrate 1, which makes it difficult to attach ICs and other electronic components that are easily affected by heat to the substrate 1. Furthermore, since a space is required on the surface side of the element 2 for arranging the light source 3, the transparent protection plate 4 is
The distance between and element 2! There is also the problem that this increases the size of the liquid crystal display, making the entire liquid crystal display thicker, which is disadvantageous in terms of mounting.

Therefore, an object of the present invention is to arrange a light source for illuminating a liquid crystal display element at a remote position on the side of the element, while reflecting light from this light source to the element side at a position on the front surface of the element, and also to reflect light from the element to the front side of the element. By installing a half mirror that can transmit reflected light, it prevents the effects of heat on the elements and the board, improves workability, and makes it possible to attach parts.It also makes the entire device smaller and easier to mount. The purpose of the present invention is to provide a liquid crystal display device that can perform the following functions.

Hereinafter, the present invention will be explained with reference to illustrated embodiments.

FIG. 2 shows an embodiment of the present invention, in which 10 is a substrate;
11 is a liquid crystal display element supported by this substrate 10.

Reference numeral 12 denotes a half mirror, which is a feature of the present invention, and is made of a normally used transparent glass plate having a light transmittance of about 50% or a transparent glass plate having some reflectance. This half mirror 12 is placed in front of the element 11,
The half mirror 12 is arranged at an angle of about 45'' with respect to the element surface.In this case, if the half mirror 12 is rectangular, tilting the mirror in the direction of its short side will reduce the amount of mirror that occupies the front of the element. The width dimension can be made as small as possible. On the other hand, the lamp 13 as a light source for illumination is installed at a position to the side of the element 11 and further away from the element, and is configured to illuminate the inner surface of the half mirror 12. 14 is a transparent protection plate, but it is not particularly required.

According to the above configuration, the illumination light emitted from the lamp 13 is not directly irradiated onto the element 11, but most of it is irradiated onto the inner surface of the half mirror 12. A part of it is reflected by the half mirror 12 and projected onto the surface of the element 110,
Here, the light illuminates the element and is reflected again, this time passing through the half mirror 12 and reaching the front of the element 11. From this K, the display on the surface of the element 11 can be confirmed.

Therefore, according to this configuration, satisfactory illumination can be achieved without disposing the lamp 13 near the element 11, so that the heat of the lamp 13 hardly affects the element 11 and the substrate 10 in this vicinity. do not have. As a result, element 1
An electronic component 1 that can fully exhibit the performance of 1 and is not easily affected by heat such as an IC on a substrate 10 near the element.
5 can be installed. In addition, since it is not necessary to arrange the lamp 13 in front of the element 11, the space in front of the element only needs to be the space for arranging the half mirror 12, and the thickness of the entire display device can be reduced.

FIG. 3 shows another embodiment of the present invention, in which 10 is a substrate, 11 is a liquid crystal display element, and 13 is a lamp as a light source. In this example, the structure of the half mirror 12A disposed on the front side of the element 11 is formed into a sawtooth cross-section having a slope 16 of approximately 45'' on the back surface as shown in the figure.
This slope 16 is arranged close to the front side of the element 11 so as to face the lamp 13.

Therefore, according to this liquid crystal display device, the light from the lamp 13 is reflected on the slope 16 of the half mirror 12A to illuminate the surface of the element 110, and after illumination, the light from the half mirror 12A
It will pass through A and reach the front. This eliminates the need for the lamp 13 to be provided near the element 11 as in the previous example, making it possible to improve the performance of the element 11 and to attach the electronic component 15. Furthermore, in this embodiment, the half mirror 12A is formed into a sawtooth shape, so that the space occupied by the mirror in the thickness direction on the front side of the element can be made extremely small.
This allows the overall thickness of the device to be further reduced than in the previous example. In this example, since the surface of the half mirror can be made flat, it can also serve as a protection plate, which is effective in reducing the number of parts.

As described above, according to the liquid crystal display device of the present invention, while the half mirror is installed in front of the liquid crystal element, the light source can be installed away from the element, thereby eliminating the influence of heat from the light source and improving the performance of the element. At the same time, parts can be freely attached, and the overall thickness of the device can be made thinner, making the mounting advantageous.

[Brief explanation of drawings]

FIG. 1 is a sectional view of a conventional device, and FIGS. 2 and 3 are sectional views of different embodiments of the present invention. 10... Substrate, 11... Liquid crystal display element, 12.12
A... Half mirror, 13... Lamp (light source), 1
4...Transparent protection plate, 15...Electronic component. Agent Patent Attorney Susuki 1) Toshi Kojikata, 5, 1st
Figure 3 Figure 513-

Claims (1)

[Claims] 1. In a liquid crystal display device that includes a liquid crystal display element and a light source that illuminates the same, the light source is placed at a position apart from the liquid crystal display element on the side, and the light source is placed in a position in front of the liquid crystal display element. 1. A liquid crystal display device comprising a half mirror that reflects light from the element toward the element while transmitting light from the element.