JPS5825405Y2 - How to make a difference - Google Patents

Description

[Detailed explanation of the idea] The present invention relates to a liquid crystal display device equipped with a lighting device.

Conventionally, when displaying using an FE type liquid crystal panel, when pressing a button, the reflective surface is placed behind the block of the liquid crystal panel, which has polarizing plates pasted on the front and rear surfaces of the liquid crystal panel, to cause a moderate amount of scattered reflection and uniform reflection. A reflective plate that has been treated to achieve brightness is installed, and the display area of characters, numbers, etc. on the liquid crystal display is set against the background of the reflective plate, which has a uniform brightness due to the light coming from the front side of the panel. is generally displayed in black (lower brightness than the reflective surface).

According to the above method, in daylight, when the amount of light incident from the front of the LCD panel block is sufficient, the reflector becomes a bright, evenly illuminance surface that enhances the contrast with the LCD display, but when the button is pressed in the dark, Since it is completely useless for display, it becomes necessary to solve the above problem by illumination in dark places, but conventional illumination methods have the following configuration.

Namely, there are two methods: (1) a method in which a light source lamp is installed in front of the liquid crystal panel block; and (2) a method in which a light source lamp is installed behind the reflector.

1, the light source lamps protrude in front of the liquid crystal panel block, which not only imposes design constraints but also increases the depth of the display device. It has been pointed out that the reflection makes it difficult to see.

In addition, for 2, a material with high light transmittance and light diffusivity (for example, a milky white diffuser plate) is used as the reflector, and in order to prevent hot spots, a large number of light source lamps are placed at a fixed position behind the reflector. They must be arranged at a distance greater than 100 degrees, making it difficult to provide uniform brightness on the reflector, increasing power consumption, and increasing the depth of the display device.

In view of the above, the present invention aims to provide a liquid crystal display device equipped with a lighting device that maximizes the advantages of a liquid crystal display device, such as being able to be formed thin, displaying uniform brightness, and consuming less power. It is something to do.

A reflective plate is placed close to the back surface of a transparent substrate whose back surface has been subjected to an appropriate light diffusion process, and a light source lamp is used to illuminate the side end surface of the transparent substrate so that a uniform illuminance distribution can be obtained on the front side of the substrate. The applicant has already filed a patent application (Japanese Patent Application No. 50-12799) for the "light diffusing device".

This case utilizes the light diffusing device in the above patent application, and examples thereof will be described below with reference to the drawings.

In this embodiment, a digital watch is assumed, and 1 is an FE type liquid crystal panel, and 2a and 2b are polarizing plates attached to the front and back surfaces of the liquid crystal panel, respectively.

Reference numeral 3 denotes an end face 3a of a transparent substrate facing the light source lamp 5.

3a' and the front surface 3b are smooth surfaces, and the cross-sectional shape is as shown in FIG. 4.5, the shape is cut by a parabola or a straight line along the cross-sectional direction using a base line at a certain distance from the end surface 3a, and the back surface 3c is the fifth As shown in the figure, it is roughened in a parallel hairline shape along the longitudinal direction so as to give directionality to the reflected light and transmitted light distribution with respect to the incident direction of light, and to reflect the light flux as far as possible to the front side.

Reference numeral 4 denotes a white matte reflecting plate that is attached to or placed close to the back surface of the transparent substrate 3.

5 is a light source lamp disposed close to the end surface of the transparent substrate as described above.

When the area of the display section is relatively small, it is efficient to arrange the transparent substrate 3 by using one cut-shaped transparent substrate 3, but when the area of the display section is relatively large, it is efficient to use a single transparent substrate 3. 3
As shown in the figure, a rectangular parallelepiped-shaped transparent substrate 3 may be used, and the light source lamps 5 may be installed on both end faces of the transparent substrate 3, or a transparent substrate 3 cut in the shape shown in FIG. Two pieces may be installed so that their cut surfaces face each other. In the device of the present invention configured as described above, the light flux from the light source lamp enters from the end faces 3a and 3a' of the transparent substrate 3, and a part of the light beam enters the front surface. The light travels in parallel, and some of the light travels to the back side, some of which is scattered and reflected by the back surface, and then travels to the front side.Most of the partially transmitted light is reflected by the opposing reflector and is transmitted or scattered through the back side of the transparent substrate. It repeats reflection and refraction and moves toward the front.

Due to such complex reflection, transmission, and refraction movements, the background of the liquid crystal display becomes a uniform bright illuminance surface.

According to the present invention, by providing the light source lamp 5 with various colors or by providing the reflector plate 4 with various colors, it is possible to provide color changes to the background display of the liquid crystal display. .

In the liquid crystal display device of the present invention constructed as described above, the liquid crystal display is bright and uniform in brightness, and the colorful background stands out in contrast, so that it is aesthetically pleasing. , it is easy to check even in a dark place.

In addition, the interlayer device part has a simple structure as described above, and is easy to block, making it suitable for mass production.Since only one or two light source lamps are required, power consumption is low, and the arrangement of light source lamps is Since the installation position is on the side of the transparent substrate,
A liquid crystal display device that is extremely thin and does not take up much depth can be obtained.

[Brief explanation of the drawing]

Fig. 1 is a front view of one embodiment of the present invention, Fig. 2 is a side view of the embodiment of Fig. 1, Figs. 3 and 4 are cross-sectional views for explaining an example of arrangement of a transparent substrate, and Fig. 5. is a perspective view of a transparent substrate. 1...Liquid crystal panel, 2a, 2b...polarizing plate, 3...
- Transparent substrate, 4...Reflector, 5...Light source lamp.

Claims (1)

[Scope of Claim for Utility Model Registration] A liquid crystal panel block having polarizing plates disposed on the front and rear surfaces of a liquid crystal panel, a transparent substrate disposed behind the liquid crystal panel block, and a back surface of the transparent substrate. a reflector disposed in contact with or in close proximity to the transparent substrate; and a light source disposed on at least one side of the transparent substrate, the transparent substrate having a front surface facing the liquid crystal panel block and a light source disposed on at least one side of the transparent substrate. The facing side surface is formed smooth, and the back surface facing the reflecting plate is roughened in a parallel hairline shape in the direction along the incident light from the light source, and the reflecting plate reflects the transmitted light from the transparent substrate. A liquid crystal display device with a lighting device.