JPS647389Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an illuminated keyboard device, and its object is to make the illumination state of the push buttons uniform and to improve the contrast with displayed characters.

Generally, in illuminated keyboards, push buttons molded from milky white or other translucent resin are often used, and scattering occurs when light is moderately scattered by particles such as white pigment in the molded body. The entire push button appears to shine when exposed to light. Conventionally, push button 1 like this was made entirely of a material with uniform transparency, as shown in Figure 1, and the incident light was extremely attenuated. In order to prevent this from happening, it is necessary to make the entire body a light-colored semi-transparent body, but if a light source such as a light emitting diode is used, which emits a relatively small amount of light, uneven lighting will occur on the push button. In addition, since the degree of whiteness of the push button is low, there is a drawback that the contrast with the letters engraved on the top surface of the push button is not good in daylight. Although the contrast with the text is good, there is a drawback that a large amount of light is lost inside the push button, resulting in insufficient light emission from the push button.

In view of the above-mentioned drawbacks, the present invention consists of a push button made of a molded body consisting of a double structure with different densities, so that the push button emits light evenly as a whole, and even in daylight, it is able to match the displayed characters. The contrast has been improved.

The embodiment will be explained in detail below with reference to Figure 2 and the following drawings. In Figure 2, 1 is a push button colored, for example, milky white by mixing an appropriate amount of pigment with acrylic resin or ABS resin. The base part 2 contains less pigment to give a pale milky white color, whereas the display part 3 at the top contains more pigment to give a darker milky white color. It is formed to a thickness of about 1 to 2 mm. Incidentally, as shown in FIG. 3, a separately molded dark-colored display portion 3 may be fitted onto a light-colored base portion 2.

FIG. 4 is a plan view of a keyboard in which the push buttons 1 are attached to a transparent frame 4 made of synthetic resin such as transparent acrylic resin, FIG. 5 is a cross-sectional view taken along line A-A, and FIG. In the figure, 5 is a cavity in which a light source 6 is housed. A rectangular hole 7 whose side surface is inclined at 45 degrees with respect to the light source direction is formed adjacent to the push button 1 at a position not adjacent to the light source 6.

Further, a dome-shaped movable part 9 integrally formed with an elastic support 8 is located at the bottom of the push button 1, and a fixed contact 1 on an insulating substrate 13 is located on the lower surface of the movable part 9.
A movable contact 10 is fixed opposite to 1. Note that a panel 12 made of an opaque plate is disposed on the upper surface of the transparent frame 4.

To explain the illumination mechanism of the keyboard device, the light from the light source 6 directly enters the push button 1 that is close to it, and the light that enters the square hole 7 forms a critical angle with respect to the plane of the square hole 7. Since it enters at a sufficiently larger angle of incidence, it does not enter the inside of the square hole 7,
It is totally reflected on the incident surface and enters the push button 1. This light is scattered within the base 2 and spreads throughout the base 2,
The light scattered upwardly is further scattered inside the display section 3, and the entire display section 3 appears to emit light uniformly. Note that since the thickness of the display section 3 is made thin, the decrease in the amount of light due to the provision of the display section 3 is extremely small, and the illumination state of the push button 1 is maintained at a brightness that does not cause any practical problems.

Furthermore, in daylight, the display section 3 of the push button 1 has a high density of white color and has a good contrast with the displayed characters, making it extremely easy to see. In addition, when forming a rectangular molded object such as a push button, the surface becomes concave (so-called sink marks).
In order to prevent this, holes 14 are often formed by protrusions provided in the molding die as shown in FIG. Due to the influence of Since the brightness is made uniform, the influence of the holes 14 is removed, and a uniform illumination state can be achieved.

It goes without saying that even when the push button 1 is formed as a translucent body in a color other than milky white, such as red or blue, the same effect can be achieved by forming the push button 1 into a double structure of light and shade as in the present invention.

[Brief explanation of the drawing]

Fig. 1 is a sectional view of a conventional push button, Fig. 2 and the following are related to the present invention, Fig. 2 a is a plan view of the push button, b is a sectional view, and Fig. 3 is an example of another embodiment; 4 is a plan view of the keyboard device, FIG. 5 is a sectional view taken along FIG. 4 A-A, FIG. 6 is a sectional view taken along FIG. 4 B-B, and FIG. is a sectional view of a push button with a different structure. 1...Push button, 2...Base, 3...Display section, 4...
...Transparent frame.

Claims (1)

[Scope of utility model registration request] A transparent frame made of synthetic resin is provided with push buttons made of a plurality of semi-transparent bodies arranged to be movable up and down, each of the push buttons having a base made of a light-colored semi-transparent body, and a thin frame formed on the top of the base. The transparent frame is provided with a rectangular hole inclined at approximately 45 degrees with respect to the push button, and light sources are arranged on both sides of the rectangular hole. The illuminated keyboard is characterized in that the light from the light source is reflected by the end face of the square hole, and the light that has entered the base is scattered by the base and the display section to cause the push buttons to emit light. Device.