JPH0521233B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to an illumination device for a liquid crystal display suitable for displaying messages on radios, telephones, and the like.

BACKGROUND ART FIG. 4 is a diagram showing an example of a conventional liquid crystal display, in which 1 is a light source such as an LED, 2 is a printed circuit board,
3 is an acrylic board, 4 is a silk surface provided on the surface of the printed circuit board 2, 5 is a notch hole provided in the printed circuit board 2 for mounting the light source 1, 6 is a notch provided at both ends of the acrylic board 3, 7 8 is a Fresnel processed surface, and 8 is a light emitting surface of the light source 1.

With the above configuration, the light emitted from the light emitting surface 8 of the light source 1 as shown by arrow A enters the notch 6 as shown in FIG.
A portion of the light is reflected by the Fresnel processed surface, and a portion of the light passes through and is reflected by the silk surface 4, illuminating a liquid crystal surface (not shown) placed in front of the acrylic plate 3 from the back surface.

Problems to be Solved by the Invention However, the configuration shown in FIG. 4 has a problem in that it becomes expensive because processing is required to provide the acrylic plate 3 with a Fresnel processed surface. In addition, since the light emitting surface of light source 1 faces horizontally, the amount of light is maximum in the direction of arrow A, which is the center of the directivity, and this has the disadvantage that the illumination at the corners of the rectangular liquid crystal surface is dark. It was hot.

SUMMARY OF THE INVENTION An object of the present invention is to eliminate the drawbacks of the above-mentioned conventional examples and to provide a liquid crystal display device which has a simple structure and has less light unevenness on a liquid crystal surface.

Means for Solving the Problems In order to achieve the above object, the present invention provides a transparent resin plate and a reflective surface at the lower part of the liquid crystal unit, and allows the liquid crystal unit to have an upward direction through a notch provided at the end of the resin plate. The light from the light source is introduced into the interior of the resin plate, and a part of the light is refracted downward by a slope provided above the notch.

Effect Since the present invention is constructed as described above, the portion of the light component introduced into the resin plate that travels upward is refracted at the inclined portion and directed toward the reflective surface, so that the effective component for illumination is released. Also, since the light source is facing upward,
It has the effect of not getting dark in the direction of the end of the resin plate.

Embodiment An embodiment of the present invention will be described below with reference to the drawings. In Fig. 1, 11 is an LED (light emitting element) as a light source, 12 is an acrylic plate as a type of transparent resin plate, 13 is a notch, 14 is an inclined part, and 15 is a
The light emitting part of the LED 11, 16 is a lead of the LED 11, and other symbols similar to those in FIG. 4 represent the same names. FIG. 2 is a partial sectional view of FIG. 1.

Next, regarding the operation of the above configuration, the inclined diagram is shown in FIG.
This will be explained using a cross-sectional view in FIG. 2. Acrylic board 12
The upward light emitting portion 15 of the LED 11 is soldered to the printed circuit board 2 via leads 16 at both ends of the
The light from is provided at the end of the acrylic plate 12.
It enters the acrylic plate 12 through the notch 13 where the LED 11 is housed inside, moves upward as shown by the arrow E, is reflected by the slope 14 provided at the top of the cutout 13 of the acrylic plate 12, and moves downward. The light is reflected upward again by the white silk surface 4 and travels as shown by the arrow H, and irradiates a liquid crystal surface (described later) provided above together with the direct light shown by the arrow H. In the above configuration, since the light emitting surface 15 is provided above the LED 11, light is emitted isotropically in a plane parallel to the printed circuit board 2, as shown by arrows D and C in FIG. Since the light enters the acrylic plate 12, it is sufficiently diffused inside the acrylic plate 12, so that a part of the liquid crystal surface does not become dark. In addition, since the LED 11 is directly attached to the printed circuit board 2 via the lead 15,
There is no need for a cutout hole for inserting the LED 11. Further, the reflection within the acrylic plate 12 is not simple, and is generally reflected multiple times mainly at the interface with the air. An example of this is shown by the arrows in FIGS. 1 and 2.

FIG. 3 is a diagram showing the overall configuration of the present invention,
In FIG. 3, reference numeral 17 denotes a liquid crystal unit, which is provided with external connection patterns 23 at its upper and lower ends.
2 is a printed circuit board, and a connection pattern 22 is connected to a connection pattern 23 of the liquid crystal unit 17.
It is equipped with Reference numeral 18 denotes a pair of connecting rubbers each having a conductor inside, and the connecting rubbers 18 are connected to the liquid crystal unit 17.
A vertical connection is made between the connection pattern 23 of the printed circuit board 2 and the connection pattern 22 of the printed circuit board 2. 1
Reference numeral 9 denotes a reflecting plate, which reflects light from the outside to provide indirect illumination of the liquid crystal unit 17. Reference numeral 20 denotes a holding fitting for holding the above-mentioned components on the printed circuit board 2. The above-mentioned components are stored in the holding fitting 20, and the pawls 24 of the holding fitting 20 are inserted into the notch holes 2 of the printed circuit board 2.
1, the above component can be held on the printed circuit board by twisting and bending the tabs 24 protruding from the back surface of the printed circuit board 2.
At the same time, the connecting rubber 18 is sandwiched between the connecting pattern 23 of the liquid crystal unit 17 and the connecting pattern 22 of the printed circuit board 2, and is compressed and brought into close contact with the connecting pattern 23, thereby making it possible to connect the patterns. With the above configuration, the liquid crystal unit 17 can display information, but since radios, telephones, etc. are used day and night, night lighting is required so that the display on the liquid crystal unit 17 can be seen even at night. The liquid crystal unit 17 is illuminated from the rear surface by illuminating the light emitted from the acrylic plate 12 and the silk surface 4 to the front.

Effects of the Invention As explained above, according to the present invention, the light emitting part of the light source is directed upward and guided into the resin plate, and a part of the light source is provided with an inclined part to refract the introduced light and direct the light in the direction of the reflecting surface. Since the structure is configured to increase the light component, there is no need for a Fresnel surface that conventionally required complicated processing, and there is an advantage that the liquid crystal surface is illuminated with even light.

[Brief explanation of the drawing]

FIG. 1 is a perspective view of a lighting device for a liquid crystal display according to an embodiment of the present invention, FIG. 2 is a sectional view of essential parts in the configuration shown in FIG. 1, and FIG. FIG. 4 is a perspective view showing the entire structure of a liquid crystal display, and FIG. 4 is a perspective view showing the configuration of a conventional lighting device. 2...Printed circuit board, 4...Silk surface, 11...
...LED, 12...Acrylic plate, 13...Notch,
14... Inclined part, 15... Light emitting part, 16... Terminal.

Claims (1)

[Claims] 1. A display liquid crystal unit is provided with a reflective surface with a translucent resin plate sandwiched in between, and a light source provided on the inner surface of a notch provided at the end of the resin plate and having a light emitting part on the upper surface. The light emitted from the light source is introduced into the resin plate, and a part of the emitted light is refracted by an inclined part provided above the notch, and the light reflected within the resin plate is directly or A lighting device for a liquid crystal display, which illuminates the liquid crystal unit from below by guiding the light upward through a reflective surface.