JPH01255118A - Back-lighted type push button switch - Google Patents

Abstract

PURPOSE:To uniformly back lighting over the whole push button, and also improve irradiation efficiency by arranging a light leading plate leading the light of an emitter beneath a push button. CONSTITUTION:A diaphragm 2 for opening/closing a contact part is arranged on the upper surface of a printed board 1, and also the push button 4, having the projection 4a pressing the diaphragm via an insulation sheet 3, is retained in the space part 6 of a case 5 on the upper part of the diaphragm 2. And a light leading plate 7 of a plane view rectangle state is arranged in the part 6 beneath the button 4, and the projection 4a of the button 4 is insertedly passed a through hole 8 formed at the middle of the plate 7. And the emitter 9 irradiating the light to the plate 7 is arranged to the given position in the inside of the part 6. This enables the light irradiated from the emitter 9 to enter the plate 7 and uniformly back lighting over the whole lower surface of the button 4, from the upper part, and also improve irradiation efficiency.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to an illuminated push button switch used in AV equipment such as audio equipment and OA equipment such as key telephones.

2. Description of the Related Art A conventional illuminated push button switch has a structure as shown in FIG. That is, a light emitting body (light emitting diode) 33 is arranged between two diaphragms 32A and 32B for contact opening/closing arranged on the upper surface of the printed circuit board 31, and the lower surface of the case 34 above the light emitting body 33 In addition, a V-shaped protrusion 36 was formed to reflect light toward each push button 35A, 35B.

Problems to be Solved by the Invention According to the above-mentioned conventional configuration, since the contact portion is located directly below the push button, the light from the light emitting body 33 is directed to the V-shaped protrusion 36.
Since the light is reflected in an oblique direction and guided to the push buttons 35A and 35B, there is a problem that the light emission state at the push buttons becomes uneven and the collection efficiency of the reflected light is poor.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide an illuminated push button switch that can solve the above problems.

Means for Solving the Problems In order to solve the above-mentioned problems, the illuminated push button switch of the present invention emits light from five light emitters directly below the push button that presses the diaphragm T1 for opening and closing the contact via the protrusion. A light guide is arranged to guide the light, and the protrusion of the push button is inserted into a through hole formed in the light guide.

Effects According to the above configuration, the light guide plate that guides the light from the light emitter is disposed directly below the push button, so that the entire push button can be illuminated uniformly, and the irradiation efficiency is also improved.

EXAMPLE A first example of the present invention will be described below with reference to FIGS. 1 and 2.

1 and 2, reference numeral 1 denotes a printed circuit board, on the upper surface of which is arranged a diaphragm 2 for opening and closing contact parts (not shown), and above the diaphragm 2 is an insulating sheet 3. A push button 4 having a protrusion (protrusion) 4a that presses a diaphragm is connected to the case 5 through the
It is held in the space 6 of. A light guide plate 7 having a rectangular shape in plan view is arranged in the space 6 directly below the push button 4, and a through hole 8 is formed in the center of the light guide plate 7.
The projection 4a of the push button 4 is inserted through the through hole 8. Further, at a predetermined position inside this space 6, a light emitting body (light emitting diode) that irradiates light onto the light guide plate 7 is provided.
9 is placed.

Therefore, the light emitted from the light emitter 9 enters the light guide plate 7,
Then, the entire lower surface of the push button 4 is irradiated from the upper surface of the light guide plate 7 .

Next, a second embodiment will be explained based on FIGS. 3 and 4.

This push button switch is of a seesaw type.

That is, two diaphragms 12A and 12B are arranged on the upper surface of the printed circuit board 11, and two holding parts 15A and 15B are arranged on the upper surface in the space 14 formed inside the upper case 13. , diaphragm 1 on the bottom surface
Two protrusions (protrusions) 16A, 1 for suppressing 2A, 12B
A pushbutton 17 with 6B is arranged.

A light guide plate 18 and a light emitting diode (light emitting diode) 19 for illuminating the vicinity of each holding part 15A, 1513 are disposed in the space 14 on the negative side of each of the diaphragms 12A, 12B. Through holes 20A are provided in the light plate 18 at positions corresponding to the respective diaphragms 12A and 12B.
20B and each protrusion 16A of the push button 17.

16B is inserted through the through holes 20A and 20B, respectively, and comes into contact with each diaphragm 12A and 12B. Furthermore, the light emitter 19 has both diaphragms 12A, 1
2B, and a hanging portion 18a is provided at the center of the light guide plate 18.
This hanging portion 18a has a housing chamber 21 that accommodates the light emitter 19.
is formed. By the way, to explain the light guide plate 18 in detail based on FIGS. 4(a), (b), and (c), the upper part of the storage chamber 21 is shaped like a hollowed out hexagonal pyramid, and each pyramidal surface (a) to ( f) is a mirror surface having an angle that allows light to easily enter. Note that the lower part of the storage chamber 21 is shaped like a hollowed out rectangular parallelepiped.

Further, the upper surface (g) (h
) and the lower surface (j) are diagonally bent so that the (g) surface and (i) surface are substantially parallel to each other. This (g)
The surfaces (h) and (h) are mirror surfaces with angles that totally reflect the incident light, and (i) (j) (k)
The surface is textured to diffuse the light.

The material of the light guide plate 18 is such that it can be easily diffused.
Preferably, a molded resin containing a diffusive material is used.

Therefore, the light emitted from the five light emitters 19 is refracted and enters the conical surfaces (,) to (f) of the storage chamber 21 as shown by arrow A in FIG. 4, and spreads throughout. The light that reaches the g-plane and the 6-plane is totally reflected, diffused by the diffusing material, and spread uniformly to the tip of the light guide plate 18. When the light reaches 1p-), it is diffusely reflected by the grained surface and emits light uniformly, causing the presser portion 15A to emit light.

The area around 15B will be uniformly illuminated.

Furthermore, in the second embodiment described above, a seesaw-type one in which a pair of diaphragms are alternately suppressed is described, but as in the third embodiment shown in FIG. Of course, the present invention can also be applied to a device in which each contact point is opened and closed by a separate push button 31A, 31B.

Effects of the Invention According to the above configuration of the present invention, the light guide plate that guides the light from the light emitter is placed directly under the push button, so that the entire push button can be uniformly illuminated and the irradiation efficiency can also be improved. I can do it.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of an illuminated push button switch according to a first embodiment of the present invention, FIG. 2 is a plan view of the same, and FIG.
A cross-sectional view of an illuminated pushbutton switch in an embodiment of
4(a), 4(b), and 4(c) are a plan view, a front view, and a side view of the light guide plate, FIG. 5 is a sectional view of the illuminated push button switch in the third embodiment, and FIG. 6 is a conventional example. FIG. 2 is a cross-sectional view of the illuminated push button switch. 2...Diaphragm, 4...Push button, 4a...Protrusion, 7...Light guide plate, 8...Through hole, 9...Light emitter, 12A. 1.2B...Diaphragm, 16A, 16B...Protrusion, 20A, 20B...Through hole. Agent Yoshihiro Morimoto
Figures 3IA, 31B, 4U)

Claims (1)

[Claims] 1. A light guide that guides light from the light emitter is placed directly below the push button that presses the diaphragm for opening and closing the contact via the protrusion, and the protrusion of the push button is formed into the light guide. Illuminated push button switch inserted through the through hole.