JPH11345532A - Illuminated pushbutton switch device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an illuminated pushbutton switch device which can guide a sufficient amount of light to an actuating part while preventing the amount of illuminating light from being decreased by use and avoiding an increase in overall thickness, and which is also capable of electromagnetic shielding. SOLUTION: This switch device has a spacer 20 of an insulating resin which is provided directly on a circuit board 10 provided with a fixed contact 11 and a LED 12, and a conducting light reflecting layer 29 is formed on the surface of the spacer 20 by aluminum deposition or the like and electrically grounded. A click seat 30 of a transparent resin on which a domed part 21 corresponding to the fixed contact 11 is formed is provided in such a way as to be secured on the spacer 20 by a translucent adhesive 27, and a translucent conducting layer 39 is formed on the surface of the click seat 30 by the deposition or the like of ITO(indium tin oxide) and electrically grounded. A keytop seat 40 on which a keytop part 43 corresponding to the fixed contact 11 is formed is provided on the click seat 30. A hole is formed through the spacer 20 and the click seat 30 and a recess facing the hole is formed in the keytop seat 40. A LED storage part 19 is formed by the hole and the recess, and the LED 12 is placed in the storage part 19 with the end of the LED 12 located within the recess.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an illuminated push-button switch device used for a data input device or a switch device of a mobile communication device or the like. More specifically, the present invention employs an electromagnetic shielding structure to improve visibility at night or the like. Illuminated pushbutton switch device.

[0002]

2. Description of the Related Art As a conventional illuminated push button switch device, for example, a device described in Japanese Utility Model Registration No. 3024123 is known. In this publication, a keypad is installed via a dome sheet on a circuit board equipped with a light source, a conductive light reflecting layer is formed on the surface of the dome sheet, and a light-transmitting film is formed on the surface, An illuminated push-button switch device in which an insulating film having a conductive light reflecting layer formed thereon is laid on an area excluding the operating portion of the keypad, and the light reflecting layer of the dome sheet and the light reflecting layer of the insulating film are grounded. be written.

[0003]

However, in the illuminated pushbutton switch device described in Japanese Utility Model Registration No. 3024123 described above, the dome portion of the dome sheet is deformed by the pressing operation, so that the dome sheet is repeatedly used. As a result, the conductive light-reflecting layer on the dome sheet is fatigued and the light reflectance tends to decrease, so-called whitening is likely to occur, and the amount of light illuminating the operating part decreases with use. Since the height difference is small and the angle of light incident on the dome sheet surface from the light source becomes large, there is a problem that the operating part cannot be effectively irradiated.

It is considered that the latter problem can be solved by increasing the height difference between the dome sheet surface and the light source.
A new problem arises in that the thickness of the switch device is increased.
SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and is an illuminated push-button switch capable of guiding a sufficient amount of light to an operating portion without reducing the amount of light to be illuminated by use and without increasing the overall thickness. It is intended to provide a device.

[0005]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention provides a movable element which can be pressed and operated on a circuit board provided with a switch element and a luminous body so as to be displaceable in correspondence with the switch element. A formed translucent key top sheet is provided, a click sheet and a spacer are interposed between the key top sheet and the circuit board with the spacer positioned on the circuit board side, and a window is formed in the spacer. The switch element is formed so as to face the click sheet from the window, and the click sheet is elastically deformed by a pressing operation of the movable portion to form a disc spring portion for operating the switch element. In the illuminated push button switch device in which a receiving portion is formed continuously with the spacer and the luminous body is arranged in the receiving portion, the click sheet is made of a transparent material. And forming a fat, a conductive light reflective sheet between said spacer and said click sheet provided to electrically ground the conductive light reflecting sheet.

The illuminated push button switch device according to the present invention is a conductive light reflecting layer in which the conductive light reflecting sheet is formed by printing, plating, vapor deposition or coating on the click sheet side surface of the spacer. Aspect (Claim 2)
In particular, the aspect according to claim 2 can be configured as an aspect (claim 3) in which the spacer and the click sheet are fixed with a transparent adhesive.

Further, in the illuminated push button switch device according to the present invention, a light-transmitting conductive layer is formed on a surface of the click sheet on the key top sheet side, and the light-transmitting conductive layer is electrically grounded. (Claim 4) A mode in which a recess is formed in the key-top sheet so as to face the housing portion, and at least a part of the light-emitting portion of the luminous body is located in the recess. ).

The present invention is applied to a data input device of a portable telephone, a push-button switch device represented by a so-called numeric keypad, and particularly to an illuminated push-button switch device having a light-emitting body (light source) such as an LED on a circuit board or the like. . This illuminated push button switch device is mainly composed of a circuit board, a spacer, a conductive reflection sheet, a click sheet, and a key top sheet.

The circuit board has at least one switch element, at least one light emitter, and a circuit connected to the switch element and the light emitter on the surface. The switch element is represented by a fixed contact formed by patterning a copper foil or the like, but other elements, piezoelectric elements, and the like are also used. As the illuminant, a lamp or the like is used in addition to the LED.

As the spacer, an insulating resin film (sheet) such as polyethylene (PE) or polyethylene terephthalate (PET) having a predetermined thickness is used. The spacer is provided with a window for exposing the switch element, a hole for opening the light emitter to the key top sheet side, a notch, and the like (accommodation hole). The conductive light reflecting sheet is a metal sheet or a resin sheet having a metal layer formed thereon,
Desirably, the surface of the spacer (the surface opposite to the circuit board)
And is electrically grounded. This conductive light reflection layer is formed on the surface of the spacer by vapor deposition, sputtering, plating, lamination of foil, or the like using a conductive material such as aluminum, copper, silver, and gold.
It is formed by depositing aluminum to a thickness of 400 ° or more, or by laminating an aluminum foil having a thickness of about 9 μm using an adhesive or the like.

The click sheet has a thickness of 75 to 150 μm.
m, made of a resin film such as PET or PEN (polyethylene naphthalate) having a translucency of about m, and a coned disk spring portion that is deformed by a disk spring-like elastic deformation characteristic faces the switch element. Holes, notches, and the like (accommodation holes) are formed to face the top sheet side. The disc spring is
A movable contact, a presser, and the like are provided on the rear surface according to the type of the switch element, and are deformed by a pressing force acting on the front surface, and the movable contact and the like operate (open / close) the switch element. The receiving hole defines a receiving portion continuously with the receiving hole of the spacer, and at least a part of the light emitting portion of the light emitter is received in the receiving portion.

Further, the click sheet is provided with a light-transmitting conductive layer on the front surface or the back surface as necessary, and is electrically grounded. The light-transmitting conductive layer is made of a known transparent electrode material such as ITO (indium tin oxide), and is formed by vapor deposition.
To a film thickness of about 0 to 600 °, or to a film thickness of several tens of mm by sputtering, or to form a large number of diagonal lines at minute intervals by screen printing using a silver-based conductive ink, or a lattice of minute intervals. Is formed by printing.

The key top sheet has a disc spring portion of the click sheet, that is, a movable portion corresponding to the switch element. If necessary, a key top (member) is provided on the surface of the movable portion.
However, a projection or the like is provided on the back surface of the movable portion. This key top sheet is made of synthetic rubber such as silicone rubber or EPDM,
Polyester, polyurethane, polyolefin,
It is integrally molded by injection molding or compression molding using a translucent rubber elastic body such as a polystyrene thermoplastic elastomer, or a key top member or the like is fixed to a translucent resin sheet such as PE, PET or PEN. Be produced.

The key top sheet is provided with a light-shielding colored layer on the surface except for the movable portion and, if necessary, a light-transmitting colored layer on at least the movable portion. A character or symbol display portion indicating the function of the key or the like is formed. The display portion is formed by printing characters or the like by screen printing or by removing the light-shielding colored layer into a shape such as characters by irradiating a laser beam.

[0015]

According to the present invention, the luminous body is accommodated in the accommodating portion formed by the spacer and the click sheet, and the light emitting portion is located on the conductive light reflecting sheet. That is, the luminous body is located on the key top sheet side beyond the conductive light reflection sheet and the click sheet. For this reason, the height difference between the light emitting body and the light reflecting sheet is large, the angle of light incident on the light reflecting sheet can be reduced, and a sufficient amount of light can be guided to the movable portion. Further, since the light reflecting sheet is not affected by the displacement of the movable portion, that is, does not deform, it can be prevented from being deteriorated, and a high reflectance can be maintained for a long time. Further, since the conductive light reflecting layer is electrically grounded, it is possible to prevent electrostatic destruction due to electrostatic charging caused by contact with an operator's finger or the like, and also to perform electromagnetic shielding.

[0016]

Embodiments of the present invention will be described below with reference to the drawings. 1 and 2 show an illuminated push button switch device according to one embodiment of the present invention,
1 is a schematic cross-sectional view in which a part is enlarged, and FIG. 2 is a partially enlarged view of FIG.

In the figure, 10 is a circuit board, 20 is a spacer,
Reference numeral 30 denotes a click sheet, and reference numeral 40 denotes a key top sheet. As is well known, the circuit board 10 is made of epoxy resin or the like, and fixed contacts (switch elements) 11 are formed on the surface thereof together with a circuit pattern or the like (not shown).
(Light emitting body) 12 is provided. As described later, LED
Reference numeral 12 penetrates through the spacer 20 and the click sheet 30 and faces the back surface of the key top sheet 40 on the light emitting portion click sheet 30 at the tip. Reference numeral 90 denotes a casing of a mobile phone or the like.

The spacer 20 is made of an insulating resin film such as PET or PEN and has a predetermined thickness. The spacer 20 has a window hole 21 centered on the fixed contact 11 and a storage hole 19 centered on the LED 12.
Is formed to penetrate, and a conductive light reflecting layer (conductive light reflecting sheet) 29 is formed on the surface. Conductive light reflection sheet 29
Is formed by evaporating aluminum to a film thickness of about 400 ° or attaching an aluminum foil having a thickness of about 9 μm with an adhesive or the like. The conductive light reflection layer 29 is connected to a conductive pattern or the like on the circuit board 10 and is electrically grounded.

The click sheet 30 is made of PEN or P
It is a transparent resin film having a thickness of 75 to 150 μm, such as ET, and is adhered to the spacer 20 by the translucent adhesive 27. In the click sheet 30, a plurality of dome portions (disc spring portions) 31 having disc-like elastic deformation characteristics are formed so as to bulge toward the front surface side in correspondence with the fixed contacts 11, and
The storage hole 19 corresponding to the LED 12 (the spacer 2 described above)
0 (using the same reference numerals as the storage holes 0).
The dome portion 31 has an upper surface in contact with a protrusion, which will be described later, of the key top sheet 40 and pressed. . The storage hole 19 is continuous with the storage hole 19 of the spacer 20 described above and the key top sheet 40.
A storage portion 19 is formed together with a concave portion described later, and the LED 12 is positioned in the storage portion 19 with the light emitting portion at the tip protruding toward the key top sheet 40 as described above.

As shown in detail in FIG. 2, a translucent conductive layer 39 is formed on the entire surface of the click sheet 30. The light-transmitting conductive layer 39 is formed by sputtering ITO to a thickness of about several tens of millimeters, or
It is formed by vapor deposition to a thickness of 厚 み. The light-transmitting conductive layer 39 is formed of the conductive light reflecting layer 2 of the spacer 20 described above.
9 or directly to the conductive pattern of the circuit board 10 and grounded through the conductive pattern.

In the key top sheet 40, a key top portion (movable portion) 43 is continuous with a base portion 41, which is a support portion for the click sheet 30, via a thin skirt portion 42. The recessed portion 44 is formed in the base portion 41 and opens to the back surface side. The key top sheet 40 is integrally formed by injection molding, compression molding or the like using transparent silicone rubber. The key top 43 is
The tip protrudes out of the casing 90 so that the circuit board 10 can be pressed.
Displace to the side. The protrusion 44 abuts on the top of the surface of the dome portion 31, and presses the dome portion 31 by pressing the key top portion 43 to elastically deform the dome portion 31. The concave portion 19 is opened facing the storage hole 19 of the click sheet 30, and as described above,
A housing 19 for the LED 12 is defined.

Although illustration is omitted, the key top sheet 40 has a transparent coloring layer on the top surface of the key top portion 43 by screen printing using a transparent coloring ink, or the like.
A light-blocking colored layer is formed on the entire surface by spray coating using a carbon-containing light-blocking paint over the light-transmitting colored layer. Then, the light-shielding colored layer on the top surface of the key top portion 43 is removed into a shape such as a character or a symbol by irradiating a laser beam or the like, thereby forming a display portion for displaying the function or the like of the key top portion 43.

In this embodiment, when the key top portion 43 is pressed, the key top portion 43 deforms the skirt portion 42 and is displaced toward the circuit board 10.
Presses the dome portion 31. And the dome part 31
Due to the pressing force of the projection 44, the key top portion 43 is deformed by the elastic deformation characteristic of a conical spring to give a sense of click (click feeling) to the pressing operation of the key top portion 43.
2 contacts the fixed contact 11 of the circuit board 10 to open and close the circuit.

Further, in this embodiment, the LED 12 is turned on at night or the like, and the light emitted from the LED 12 is reflected by the conductive light reflecting layer 29 so that the key top portion 43 is turned on.
To illuminate a display unit or the like on the top surface of the key top unit 43.
Here, the LED 12 has its tip located in the concave portion 19 of the key top sheet 40 and is sufficiently separated from the surface of the spacer 20, that is, the conductive light reflecting layer 29 (there is a sufficient height difference). Therefore, the angle of light incident on the conductive light reflection layer 29 from the LED 12 is large, and a sufficient amount of light can be guided to the key top portion 43, and the display portion of the key top portion 43 can be brightly illuminated.

Further, in this embodiment, the conductive light reflecting layer 29 is provided on the spacer 20 which is not affected by the pressing operation of the key top portion 43, that is, on the surface of the spacer 20 which is not deformed by the pressing operation. Therefore, the conductive light reflecting layer 2
9 does not deteriorate due to fatigue or the like, maintains an excellent light reflectance over a long period of time, and can illuminate the display section of the key top section 43 brightly even after a lapse of years since the start of use.

In this embodiment, the conductive light reflecting layer 29 and the light transmitting conductive layer 39 are electrically grounded. For this reason, electrostatic charging due to contact with a finger during a pressing operation can be prevented, and the circuit of the circuit board 10 can be electromagnetically shielded, so that troubles due to static electricity and adverse effects of electromagnetic waves are eliminated.

[0027]

As described above, according to the present invention, the conductive light reflecting sheet is provided to be electrically grounded on the spacer provided closest to the circuit board, and the transparent light reflecting sheet is provided on the conductive reflecting sheet. The key top sheet is provided via the click sheet, and the luminous body provided on the circuit board is penetrated through the spacer and the click sheet to position the light emitting portion on the spacer. A sufficient amount of light can be guided from the light emitter to the movable part of the key top sheet, and the effect that the movable part can be brightly illuminated can be obtained.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view schematically showing a part of an illuminated push-button switch device according to an embodiment of the present invention.

FIG. 2 is an enlarged schematic cross-sectional view of a part of FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Circuit board 11 Fixed contact (switch element) 12 LED (light emitting body) 19 Storage part (storage hole, recessed part) 20 Spacer 21 Window hole 27 Transparent adhesive 29 Conductive light reflection layer (conductive light reflection sheet) 30 Click sheet 31 Dome part (disc spring part) 32 Movable contact 39 Translucent conductive layer 40 Key top sheet 41 Base part 42 Skirt part 43 Key top part (movable part) 44 Projection

Claims (5)

[Claims] A light-transmissible key top sheet in which a movable portion capable of being pressed is formed on a circuit board provided with a switch element and a light-emitting body so as to be displaceable in correspondence with the switch element; A click sheet and a spacer are interposed between the top sheet and the circuit board with the spacer positioned on the circuit board side, a window is formed in the spacer, and the switch element faces the click sheet from the window. In addition, a click spring is formed on the click sheet to form a disc spring portion that is elastically deformed by a pressing operation of the movable portion to operate the switch element, and a receiving portion is formed continuously with the click sheet and the spacer. An illuminated push-button switch device in which the illuminant is disposed on the click sheet, wherein the click sheet is formed of a translucent resin, The conductive light reflecting sheet provided, illuminated pushbutton switch device being characterized in that electrically grounded conductive light reflecting sheet between the p o. 2. The illuminated push button switch device according to claim 1, wherein the conductive light reflecting sheet is a conductive light reflecting layer formed on the click sheet side surface of the spacer by printing, plating, vapor deposition or coating. 3. The illuminated push button switch device according to claim 2, wherein the spacer and the click sheet are fixed with a transparent adhesive. 4. The illuminated push button switch device according to claim 1, wherein a light-transmitting conductive layer is formed on a surface of the click sheet on the side of the key top sheet, and the light-transmitting conductive layer is electrically grounded. 5. The illuminated push button according to claim 1, wherein a concave portion is formed in the key top sheet so as to face the housing portion, and at least a part of a light emitting portion of the luminous body is located in the concave portion. Push button switch device.