JP2006196395A - Touch switch - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a touch switch facilitating handling when manufacturing or using it. <P>SOLUTION: This touch switch 10 is to supply an electric current to a load by detecting that a conductor is brought into contact with or comes very close to an electrode plate 22 by the change of an electrostatic capacity. The touch switch 10 includes a light source disposed on the back side of the electrode plate 22 and controlled for lighting when the electric current is supplied to the load. The electrode plate 22 is formed of a non-translucent and conductive material, and has a translucent part 30 to pass light from the light source 12. The translucent part 30 is preferably a mesh-like opening. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a touch switch, and more particularly to a touch switch that detects contact or proximity of a conductor to an electrode plate by a change in capacitance and supplies current to a load.

  Conventionally, touch switches have been used for operation panels of vehicles and elevators. The touch switch is a switch that detects contact or proximity of a conductor such as a user with an electrode plate of the touch switch by a change in capacitance and supplies current to a load. Such a touch switch is generally lit in order to inform the user that the switch has been operated. In the lighting display, since the light source disposed on the back side of the electrode plate is turned on and light from the light source is displayed through the electrode plate, the electrode of the electrode plate requires conductivity and translucency. Therefore, a transparent conductive material is used as an electrode material of the electrode plate for the touch switch, rather than a metal material that is electrically conductive but is not translucent. As described in Patent Document 1, a transparent conductive film such as an ITO film is used as the transparent conductive material. Therefore, a synthetic resin sheet composed of a transparent insulating sheet and a transparent conductive film electrode covered with the transparent insulating sheet is used for the touch switch electrode plate.

Japanese Patent Laid-Open No. 3-250517

  This transparent conductive film has a small property and a hard property. For this reason, if the synthetic resin sheet is bent at the time of manufacturing the touch switch, a large stress is applied to the transparent conductive film, and the transparent conductive film may be destroyed and a conduction failure may occur. In addition, when the user directly touches the transparent conductive film when using the touch switch, the transparent conductive film, which is a thin film, may be damaged and a conduction failure may occur.

  Accordingly, an object of the present invention is to provide a touch switch that can be easily handled during manufacture and use.

  A touch switch according to the present invention is a touch switch that detects contact or proximity of a conductor to an electrode plate by a change in capacitance and supplies current to a load. It includes a light source that is controlled to be lighted when supplied, and the electrode plate is made of a non-light-transmitting and conductive material and has a light-transmitting portion that allows light from the light source to pass through. In the touch switch according to the present invention, it is preferable that the translucent part is a mesh-like opening. In addition, the touch switch according to the present invention preferably has a protective panel provided on the electrode plate.

  With the above configuration, the touch switch according to the present invention can obtain a mechanical strength sufficient for handling at the time of manufacture and use, and can be easily handled.

  In addition, by making the translucent part of the electrode plate into a mesh shape, even if a part of the mesh is broken, it goes around the broken part and becomes conductive, so the function as an electrode is completely impaired. It will never be. Further, the protection panel provided on the electrode plate improves durability such as prevention of damage caused by contact of a conductor such as a user.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a cross-sectional view of a touch switch 10 according to an embodiment of the present invention, and FIG. 2 is a perspective view of a display unit of the touch switch 10.

  As shown in FIG. 1, the touch switch 10 includes a case 16 that houses the light source 12, the circuit board 14, and the like, and a holder 27 that attaches the electrode plate 22, the display sheet 24, the protection panel 26, and the like. Attached to a vehicle or the like.

  The light source 12 is mounted on the circuit board 14 by a known die bonding technique or the like. The light source 12 is generally an LED or a bulb lamp, but is not particularly limited as long as it emits light. Further, the number of the light sources 12 may be one or plural.

  A circuit board 14 for controlling the lighting of the light source 12 and supplying a current to a load is connected to the electrode plate 22 by a lead wire 28 or the like. A wiring circuit (not shown) is formed on the circuit board 14, and a detection circuit for detecting a change in the capacitance between the electrode plate 22 and the ground, lighting control of the light source 12, and supply of current to the load A control circuit. The circuit board 14 is generally made of an epoxy resin or the like, but may be a metal material or an inorganic material such as ceramics.

  The electrode plate 22 has a connection terminal and is connected to the lead wire 28 by a connector or the like. The electrode plate 22 can be obtained by processing a metal material such as a copper alloy, an inorganic material such as conductive ceramics, or a material such as conductive synthetic resin. These materials are molded so as to have sufficient mechanical strength in handling during production and use.

  As shown in FIG. 3, the electrode plate 22 has a translucent part 30 through which light from the light source 12 passes. The translucent part 30 may have an opening by drilling or may be made of a translucent member. Moreover, generally the shape of the translucent part 30 is circular, a triangle, a quadrangle, other polygons etc., However, Other shapes may be sufficient. The translucent part 30 may be formed by punching a plate-like material or by knitting a linear material.

  When the translucent part 30 of the electrode plate 22 is an opening, the shape of the opening is preferably a mesh-like opening. By doing so, as compared with the case where several holes are present in the electrode plate 22, a wide range of the electrode plate 22 can transmit light, so that the display portion can be widened. As the mesh shape of the electrode plate 22, not only the shape shown in FIG. 3 but also the circular, triangular, quadrangular or other polygonal shapes shown in FIG. 4 can be used. Further, the mesh shape is not limited to the shape of FIG. 3 or FIG.

  The aperture ratio of the electrode plate 22 is determined from the mechanical strength and translucency of the electrode plate 22. This is because when the aperture ratio increases, the mechanical strength of the electrode plate 22 decreases, and when the aperture ratio decreases, the translucency of the electrode plate 22 decreases. An opening ratio of 10% or more can be used, but it is preferably 50% or more, particularly preferably 90% or more.

  The lead wire 28 connects the electrode plate 22 and the circuit board 14. The lead wire 28 is generally a metal wire such as a copper alloy covered with a synthetic resin or the like. The lead wire 28 is connected to the electrode plate 22 and the terminal or connector of the circuit board 14. Here, as shown in FIG. 5, a part of the electrode plate 22 can be extended in a band shape and used instead of the lead wire 28. In this case, the strip-shaped end portion of the electrode plate 22 is connected to the circuit board 14 via a connection terminal or a connector. In FIG. 5, the end portion of the electrode plate 22 has a band shape, but is not limited to the band shape, and a part of the electrode plate 22 may be connected to the circuit board 14.

  The display sheet 24 disposed on the electrode plate 22 is a sheet on which characters, figures, and the like for allowing the user to recognize are printed. For example, characters such as “AUTO” indicating that the on-vehicle air conditioner is automatically turned on and off are used as the characters and graphics. The display sheet 24 and the electrode plate 22 may be bonded with an adhesive or the like, or may be fastened with screws or the like. As the display sheet 24, a synthetic resin is generally used, but a sheet of an inorganic material such as ceramics may be used. The display sheet 24 is preferably a transparent sheet for allowing the user to recognize characters, graphics, and the like, but may be a translucent sheet, and is not limited thereto as long as it is a translucent sheet. Further, in order to distinguish it from other parts of the display sheet 24 and to make the user noticeably, the parts such as characters and figures may be colored. Moreover, in order to make the shadow of the mesh-like shape of the electrode plate 22 inconspicuous, portions other than characters, figures and the like of the display sheet 24 may be colored. Further, without using the display sheet 24, characters, figures, and the like may be printed on the protective panel 26.

  The protective panel 26 disposed on the display sheet 24 is a panel used for improving durability such as damage prevention and corrosion prevention of the display sheet 24 and the electrode plate 22. The protective panel 26 and the display sheet 24 may be bonded with an adhesive or the like, or may be fastened with screws or the like. When the display sheet 24 is not used, the protective panel 26 is disposed on the electrode plate 22 by the same method. The protective panel 26 is preferably transparent, but may be translucent, and is not limited thereto as long as it can transmit light from the light source 12. The protective panel 26 is generally preferably a synthetic resin, but an inorganic material such as ceramics may be used.

  Next, the operation of the above configuration will be described. When a conductor such as a user contacts or approaches the electrode plate 22 of the touch switch 10, the capacitance between the electrode plate 22 and the ground changes. The change in capacitance is detected by the detection circuit of the circuit board 14 and the detection signal is transmitted to the control circuit. The control circuit supplies current to the load and turns on the light source 12. The light from the light source 12 illuminates the display sheet 24 through the light-transmitting portion 30 of the electrode plate 22 or the mesh-shaped opening, and displays characters, figures, and the like drawn on the display sheet 24. The user can see that the switch has been operated by looking at the display.

It is sectional drawing of the touch switch which is embodiment which concerns on this invention. It is a perspective view of the display part of the touch switch which is embodiment which concerns on this invention. It is the figure which showed the mesh-like shape of the translucent part of an electrode plate. It is the figure which showed the kind of mesh shape of the translucent part of an electrode plate. It is the figure which showed the electrode of the electrode plate which serves as a lead wire.

Explanation of symbols

  10 Touch switch, 11 Face plate, 12 Light source, 14 Circuit board, 16 Case, 22 Electrode plate, 24 Display sheet, 26 Protection panel, 27 Holder, 28 Lead wire, 30 Translucent part.

Claims (3)

In the touch switch that detects the contact or proximity of the conductor to the electrode plate by the change in capacitance and supplies current to the load.
Including a light source that is placed on the back side of the electrode plate and controlled to turn on when a current is supplied to the load;
The electrode switch is made of a non-light-transmitting and conductive material, and has a light-transmitting portion that transmits light from a light source.   The touch switch according to claim 1, wherein the translucent portion is a mesh-shaped opening.   The touch switch according to claim 1, further comprising a protection panel provided on the electrode plate.

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