JPS591245Y2 - light guiding diffuser - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a light guiding diffuser plate installed on the back side of a liquid crystal panel in a liquid crystal digital watch or the like that is equipped with a night illumination device.

For watches that use an LCD panel, those with a night illumination device are equipped with a light guiding diffuser made of a translucent material such as acrylic on the back of the LCD panel, which allows the light from the light source to spread throughout the entire LCD panel. It is being carried out.

However, in reality, because the illumination light source is small, only the area near the light source is brightly illuminated, as shown in FIG. 4, and it rapidly becomes darker as one moves away from the light source.

In FIG. 4, reference numeral 8 denotes a conventional light guiding and diffusing plate, on the end surface of which a light source 6 is installed.

A is a very bright area, B is an area with a brightness that allows the display to be read, and C is a dark area where the display is almost impossible to read.

The present invention provides a light guiding diffuser plate that can illuminate a liquid crystal panel with uniform brightness over a wide area,
Examples thereof will be described below.

In FIG. 1, reference numeral 1 denotes a well-known liquid crystal panel, which is provided with the polarizing plate 2 and a rear polarizing plate 3, and furthermore, a light guiding and diffusing plate 4 according to the present invention is provided behind the rear polarizing plate 3. There is.

A lamp 6 serving as a light source is disposed close to the end surface 5 of the light guiding and diffusing plate 4.

The light guiding and diffusing plate 4 is made of a translucent material such as acrylic, and has a slit 7 near the end face 5, which is almost parallel to the end face 5, as shown in FIG.

Furthermore, a silver mirror coating is formed on the back surface of the light guiding diffuser plate 4 so as to function as a reflecting plate.

When this light guide diffuser plate 4 is irradiated with a lamp 6 from its end face 5, the light is diffused by the edge brightness effect by the slits 7, and most of the light guide diffuser plate 4 becomes an area B with brightness that allows the display to be read. Areas C where the display is difficult to read appear only in small areas at the corners, and almost the entire surface of the liquid crystal panel 1 is illuminated with uniform brightness.

FIG. 3 shows another embodiment, in which two slits 7 are opened in the vicinity of the end face 5 and substantially parallel to the end face 5, and the same effect as the above embodiment can be achieved.

As described above, according to the present invention, light reaches almost the entire surface of the liquid crystal panel and there is no difference in brightness, so the display is easy to see.

[Brief explanation of the drawing]

FIG. 1 is a side view of a liquid crystal display device, FIG. 2 is a front view of an embodiment of a light guiding and diffusing plate according to the present invention, FIG. 3 is a front view of another embodiment of the same, and FIG. 4 is a conventional example. FIG. 1...Liquid crystal panel, 4...Light guiding diffuser plate, 5...End surface, 6...Light source 7,7
'······slit.

Claims (1)

[Scope of utility model registration request] A light guiding and diffusing plate made of a transparent material and installed on the back side of a liquid crystal panel, in which a slit is provided in the vicinity of the end face where a light source is provided oppositely, and is substantially parallel to this end face. .