JPS639966Y2 - - Google Patents

Description

[Detailed description of the invention] The present invention relates to the structure of an illuminated keyboard switch.The purpose of this invention is to be able to illuminate all of the many keytops with the light of one light source, making it possible to operate it even in the dark. Our goal is to provide products that are small, simple in structure, and inexpensive.

In recent years, there has been a remarkable trend toward smaller and thinner keyboard switches, and the demand for illuminated keyboard switches has also increased. for example,
Keyboard switches are increasingly being used in cars, and are also used in in-vehicle telephones and the like. Naturally, at night, the inside of a car becomes quite dark, making it difficult to see the position of the key tops on the keyboard switch, so an illumination means is required to clearly display the position of the key tops. Conventionally, there have been devices that have lamps, etc. installed inside each individual switch, but if these types of switches were installed side by side to form a keyboard, it would inevitably become bulky, and
Because of its high power consumption, it was completely unsuitable as a keyboard switch for use in car phones.

The present invention was devised in view of the above-mentioned drawbacks, and the present invention solves the above-mentioned problems by effectively utilizing the light from one light source using a light guide plate so that each key top of a keyboard switch is always brightly illuminated.

An embodiment of the present invention will be described below with reference to the drawings. Reference numeral 1 indicates an illuminated keyboard switch body. Reference numeral 2 denotes a key top molded from milky white acrylic resin, and the key top 2 consists of an operating section 2a and mounting legs 2b. 3 is a top case made of transparent acrylic resin;
also serves as a light guide plate, and the corners of the side walls are approximately
45° inclined surfaces 3a and 3b, the upper surface 3c is provided with a number of holes 3d through which the mounting legs 2b of the key top 2 are inserted, and the back surface is provided with a position where the key top is attached. As shown in FIG. 3, a plurality of small conical recesses 3e are formed in the. 4 is a first light guide plate molded from transparent acrylic resin, and the first light guide plate 4 is approximately butterfly-shaped;
There is a hole 4a in the center for arranging a light source, and a pair of side edges are provided with inclined surfaces 4b, 4b for reflecting the light from the light source in the right angle direction. Reference numeral 5 denotes a second light guide plate molded from transparent acrylic resin, and the second light guide plate 5 is approximately butterfly-shaped like the first light guide plate 4, with a hole 5a in the center and a hole 5a on a pair of side edges. Slanted surfaces 5b, 5b are provided. The first light guide plate 4, the second light guide plate
To explain the shape of the light guide 5, as shown in FIG. 5, its outer circumferential shape is a combination of two parabolas with the holes 4a and 5a as focal points, and the light from the light source placed inside the hole is directed to the outer circumference. Parallel rays are reflected by a paraboloid and are emitted in both directions. 6 is a key top receiving plate, and the key top receiving plate 6 is provided with holes 6a into which the mounting legs 2b of the key top 2 are inserted. Reference numeral 7 denotes a cover made of an elastic insulating material, and the cover 7 is provided with a plurality of protrusions 7a on the inside of which movable contacts 8 are attached. Reference numeral 9 denotes a contact pattern formed on the printed circuit board 10, and the contact pattern 9 faces the movable contact 8. 11 is a small lamp that is the only light source.

Next, to explain how to assemble the illuminated keyboard switch of the present invention, first, the hole 3d in the upper case 3 will be explained.
Insert the mounting legs 2b of the key top 2 into..., place the required number of key tops on the upper case, insert the mounting legs 2b into the holes 6a of the key top receiving plate 6 from the back side, and apply the adhesive. etc. to fix both. The key top 2 is attached to the upper case 3 so as to be movable up and down. Next, the printed circuit board 10 on which the cover 7 is mounted is attached to the upper case 3 by appropriate means. Then, the first light guide plate 4 and the second light guide plate 5 are attached to the upper case 3 in a perpendicularly stacked state (see FIG. 8), and finally the lamp 11 is inserted into the holes 4a and 5a.
Assembly is completed by inserting and arranging it inside.

In the illuminated keyboard switch assembled in this way, when the key top 2 is pressed down, the key top receiving plate 6 pushes down the protruding part 7a of the cover 7, so the movable contact 8 is lowered and the contact pattern on the printed circuit board 10 is lowered. When the key top 2 is no longer pressed, the cover 7 returns to its original position due to its own elasticity.

Next, to explain the path of light from the lamp 11 reaching each keytop in the illuminated keyboard switch of the present invention, first, the light entering the first light guide plate 4 from the lamp 11 is reflected by each paraboloid. The light is guided as substantially parallel rays in the A direction and the B direction. Then, the light is reflected by the inclined surfaces 4b, 4b, changes direction, passes through the side wall 3f of the upper case 3, is further reflected by the inclined surfaces 3a, 3a, and reaches the upper surface 3c. The light is then reflected in the right angle direction by the conical recess 3e formed at the key top 2 position (see FIG. 10) and illuminates the key top 2 from the back side.

Similarly, the light entering the second light guide plate 5 from the lamp 11 is reflected by each paraboloid and guided in the C direction and the D direction as substantially parallel light rays. Then, key top 2 is illuminated through approximately the same route as described above.

As mentioned above, in the illuminated keyboard switch of the present invention, light from one light source placed on the back of the switch illuminates a plurality of key tops through the transparent first and second light guide plates and the top case. It effectively utilizes the light from one light source, has extremely low power consumption, can be made compact, and has practical effects such as being able to be used even in dark places at a low cost.

[Brief explanation of the drawing]

The drawings all show the present invention; FIG. 1 is a perspective view showing the whole, FIG. 2 is a perspective view showing the key top 2 and key top receiving plate 6, and FIG. 3 is a conical recess 3e provided in the upper case 3. 4 is a plan view of the upper case 3, FIG. 5 is an explanatory diagram illustrating the optical path within the light guide plate, FIGS. 6A and 6B show the first light guide plate 4, and FIG. A is a plan view, FIG. 6B is a side view, FIGS. 7A and 7B are the second light guide plate, FIG. 7A is a plan view, FIG. FIG. 9 is a plan view showing a state in which the light plate 4 and the second light guide plate 5 are overlapped.
The figure is a cross-sectional side view of the main parts of an illuminated keyboard switch.
FIG. 10 is an explanatory diagram showing the optical path. 2...Key top, 2a...Operation unit, 2b...
Mounting leg, 3...Top case, 3a, 3b...Slope, 3c...Top surface, 3d...Hole, 3e...Conical recess, 3f...Side wall, 4...First light guide plate, 5...
Second light guide plate, 5a... hole, 4a... hole, 5b...
Inclined surface, 6... Key top receiving plate, 6a... Hole, 7
...Cover, 7a...Protrusion, 8...Movable contact,
9...Contact pattern, 10...Printed circuit board, 1
1...Ramp, 4b...Slope.

Claims (1)

[Scope of utility model registration request] A keyboard switch comprising a plurality of translucent key tops each having mounting legs, which are inserted into holes in a top case and mounted so as to be movable up and down, approximately at the center of the back of the keyboard switch. One light source is arranged, and the light from this light source is made into approximately parallel beams by two transparent light guide plates arranged perpendicularly to each other, and is guided to the top surface through the side wall of the transparent top case, and also to each key top of the top case. An illuminated keyboard switch characterized in that the key tops are illuminated by a plurality of recesses formed at positions corresponding to the keys.