JPH0955143A - Key back light lighting effect device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To clearly display characters by uniformly lighting the characters on a key top in a back light lighting structure of a key operation part. SOLUTION: A key back light lighting effect device is composed of a key sheet 2, a printed circuit board 4, and an acrylic resin light conduction plate 3 provided between them. A switch contact 6 which is gilded and a diode chip LED8 which is soldered and packaged are arranged on the surface of the printed circuit board 4. Whole surface part of the printed circuit except this switch contact 6 and the chip LED8 are printed into white. A light emitted from the chip LED8 is reflected on the key sheet 2, the light conduction plate 3, and the printed circuit board 4, uniformly diffused all the surface of the light conduction plate especially by the reflection of the white printed part of the printed circuit board 4 so as to become a sufficient light quantity, and clearly displays characters reflected on the key sheet so as to improve the lighting effect.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a key backlight lighting effect device in a lighting structure of a key operation part of a handset part such as a mobile phone radio device and a car phone device.

[0002]

2. Description of the Related Art Conventionally, a key backlight illumination effect device used in a handset part of a mobile phone radio device, a car phone device, etc. has a structure as shown in FIG. I was using one. A key backlight illumination effect device in these radios and devices is configured to include a printed board 4, a key sheet 2, a light guide plate 3 provided therebetween, a front cover 1 for housing them, and a rear case 10.

The printed board 4 is fixed with screws or the like by aligning the notch with the rib for positioning the rear case 10.
The diode type chip LED (light emitting diode) 8 mounted on the surface of the printed board 4 is inserted into the hole 7 of the totally transparent light guide plate 3 made of acrylic resin. This hole 7
Are formed so as to be adjacent to the switch contact 5 of the button switch portion of the rubber key sheet 2 and the gold-plated switch contact 6 on the printed board 4, and the four ribs on the light guide plate 3 are cut into the printed board 4. The key sheet 2 is fixed by being fitted into the notches and fixed, and the four protrusions provided at the four corners of the key sheet 2 are inserted into the four positioning holes provided at the four corners of the light guide plate 3. The button switch portion of the key sheet 2 is inserted into the hole 9 of the front cover 1, and the hole 9 is provided corresponding to the button switch portion of the key sheet 2.

With such a configuration, the light of the chip LED 8 mounted on the printed board 4 is uniformly diffused by the printed board 4, the light guide plate 3 and the key sheet 2, and the light is emitted onto the button switch of the key sheet 2. By illuminating certain numbers and letters, no key operation error occurs when using the device at night or when using the device in a place without light.

[0005]

As described above, in the conventional handset such as a portable telephone radio device and a car telephone device, the numbers and letters on the button switches of the key sheet are evenly illuminated and clearly and clearly displayed. In order to express clearly, it was necessary to use as transparent a key sheet as possible, and to use a chip LED of a bright and non-uniform color so as to maintain translucency and uniformity. However, if the background of the key sheet is black or the color of the chip LED is red or blue, the translucency and the uniformity cannot be maintained due to user's request. .

The object of the present invention is to solve the above-mentioned conventional drawbacks.
It is an object of the present invention to provide a key backlight illumination effect device capable of obtaining sufficient translucency and uniformity regardless of the background color of the key sheet and the emission color of the chip LED.

[0007]

A key backlight illumination effect device of the present invention comprises a key sheet made of rubber or a film material and also having a button switch, and a chip LED (light emitting diode) on the surface and the button switch. And a light emitted from the chip LED, which is provided between the key sheet and the print plate and is made of a transparent acrylic resin and has a hole for inserting the chip LED. A light guide plate for diffusing light, and the chip L of the portion of the surface of the printed board covered by the light guide plate and the key sheet
All parts except the ED and the switch contact part are printed in white.

In this key backlight illumination effect device, the light guide plate and the printed board are provided with ribs and notches for positioning each other,
Further, the light guide plate and the key sheet are provided with holes and protrusions for positioning each other.

[0009]

Next, the present invention will be described with reference to the drawings.

FIG. 1 is an exploded perspective view showing a key backlight illuminating section according to an embodiment of the present invention.

In the embodiment shown in FIG. 1, the light guide plate 3
Mounted on the printed board 4, and the key sheet 2 on the light guide plate 3
Put on. The ribs 12 at the four positions of the light guide plate 3 are fitted and fixed in the corresponding notches 11 of the printed board 4, and the projections 14 provided at the four corners of the key sheet 2 in the positioning holes 13 at the four corners of the light guide plate 3. Insert and fix the key sheet 2. It should be noted that no land is provided on the printed board 4.

In this embodiment, parts that are structurally the same as those of the prior art described above are assigned the same reference numerals and explanations thereof are omitted, and only different structures will be described.
That is, in the printed board 4 shown in FIG. 1, all parts of the surface of the printed board 4 covered with the light guide plate 3 and the key sheet 2 except the chip LED 8 and the switch contact 6 are printed in white, The key sheet 2 is constructed so that the background is black and the characters are white.

In the above structure, the printed board 4
Light generated by the chip LED 8 mounted on the top is reflected by the key sheet 2, the light guide plate 3, and the printed board 4,
In particular, due to the reflection at the white printed portion of the printed board 4, one surface of the light guide plate 3 can be uniformly diffused and a sufficient amount of light can be obtained. Can be clearly and clearly displayed and can be sufficiently read. Moreover, the key sheet 2 and the chip L
When selecting the type of the ED 8, for example, the key sheet 2 can be selected from various combinations of the ground color and the blank character, and the chip LED 8 can be selected from many emission colors such as white, red, and blue. Productivity will be improved, and it will be possible to select from a wide range of perspectives when making design decisions.

[0014]

As described above, in the conventional structure, when the printed board 4 whose surface is not printed in white is used, the key sheet 2 is white on a black background, or When the brightness of the chip LED 8 was dark, the lighting effect was weakened, and the characters on the key sheet 2 could not be clearly expressed.

According to the present invention, however, the parts other than the chip LED 8 and the switch contact 6 and the land are not provided on the surface of the printed board 4 covered by the light guide plate 3 and the key sheet 2, and the chip LED 8 and the switch contact are not provided. By printing all the parts other than 6 in white, it is possible to maintain the uniformity of brightness and sufficient brightness, and clear all the characters written on the key sheet 2 even in a dark place. Moreover, there is an effect that it can be clearly expressed and viewed. Moreover, the number of chip LEDs 8 on the printed board 4 can be small, which leads to cost reduction.

[Brief description of drawings]

FIG. 1 is an exploded perspective view showing a key backlight illumination unit according to an embodiment of the present invention.

FIG. 2 is a sectional view showing a main part of an example of a conventional key backlight illumination effect device.

[Explanation of symbols]

 1 Front Cover 2 Key Sheet 3 Light Guide Plate 4 Printed Board 5 Switch Contact Part 6 Switch Contact Part 7 Hole 8 Chip LED 9 Hole 10 Rear Case 11 Notch 12 Rib 13 Positioning Hole 14 Projection

Claims (3)

[Claims] 1. A key sheet made of rubber or a film material and also having a button switch, and a chip LE on the surface.
A printed board having a switch contact portion for contacting the D (light emitting diode) and the button switch, a transparent acrylic resin provided between the key sheet and the printed board, and the chip LED inserted therein. And a light guide plate having a hole for diffusing light emitted from the chip LED, and the chip LED in a portion of the surface of the printed board covered by the light guide plate and the key sheet.
And a key backlight illumination effect device, wherein all parts except the switch contact part are printed in white. 2. The key backlight illumination effect device according to claim 1, wherein the light guide plate and the printed board are provided with respective ribs and notches for positioning each other. 3. The key backlight illumination effect device according to claim 1, wherein the light guide plate and the key sheet are respectively provided with a positioning hole and a protrusion for mutual positioning.