JPH0722427U - Membrane switch - Google Patents

Abstract

(57) [Summary] [Purpose] Excellent texture as a membrane switch,
It provides a feeling of touch, printability, and workability, and further improves dimensional accuracy by heat. [Structure] A switch contactor 9 is formed on a fixed contact support plate 4, a circuit pattern 7 and a connector lead portion 8 are provided, and a switch contactor 9 is provided on a movable contact support plate 2.
And a circuit pattern 7 and a connector lead portion 8 are formed so as to face each other with a spacer 3 in between, and the movable contact support plate 2 is sandblasted on the opposite surface of the switch contactor 9. It has a surface decorative plate 21 made of a polyester film having a center line average roughness of 0.2 to 1.0 μm by treatment.
Further, the transparent resin layer 22 is provided on the sandblasted surface of the surface decorative plate 21.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a membrane switch.

[0002]

[Prior art]

 Membrane switches are flat touch panel switches without push buttons and are used in a wide range of fields such as calculators, personal computers, microcomputers, PPCs, and microwave ovens. This membrane switch is printed on the back side of a plastic film by silk screen printing, and the design of the switch part is printed in reverse and mounted on the surface of the switch. In addition, since the silk screen may be printed on the surface with a raised surface, or thermoformed, the key part of the switch may be made convex so that the touch feel during operation may be improved. Polycarbonate sheets with embossed finish are often used, but they have various problems.

[0003]

[Problems to be solved by the device]

 The embossed polycarbonate sheet is used because it has the excellent texture, feel, printability, and processability as a membrane switch, but polycarbonate has a large coefficient of thermal expansion. The dimensions are likely to be misaligned in the processing step after printing, which is a cause of lowering the yield in manufacturing the membrane switch.

[0004]

[Means for Solving the Problems]

 The present invention provides the same texture, feel, printability, and workability as embossed polycarbonate sheets by providing a transparent resin layer on the sandblasted surface of a surface decorative sheet made of sandblasted polyester film. Further, the dimensional accuracy due to heat is remarkably improved.

In the membrane switch of the present invention, the switch contact 9 is formed on the fixed contact support plate 4, the circuit pattern 7 and the connector lead portion 8 are provided, and the switch contact is formed on the movable contact support plate 2. In the membrane switch 1 in which the child 9 is formed and the circuit pattern 7 and the connector lead portion 8 are provided so as to face each other with the spacer 3 interposed therebetween (FIG. 1), the movable contact support plate 2 is a switch contactor. 9 has a surface decorative plate 21 made of a polyester film whose center line average roughness is 0.2 to 1.0 μm by sandblasting, and a transparent resin is applied to the sandblasting surface of the surface decorative plate 21. The membrane switch is characterized by having a layer 22 (FIG. 2).

The movable contact support plate 2 to be pressed has a switch contactor 9 formed on the back surface of the substrate film 23, and a polyester film having a transparent resin layer 22 formed on its processed surface by sandblasting the opposite surface. The surface decorative plate 21 made of a film is adhered with the double-sided tape 5 or the like. It is also possible to print a pattern such as a switch portion on the surface of the substrate film 23 opposite to the switch contact 9 or the surface of the surface decorative plate 21 opposite to the sandblasted surface by silk screen printing or the like. Further, the switch film 9 is formed on the back surface of the substrate film 23 itself by using a sandblasted polyester film, and the transparent resin layer 22 is provided on the sandblasted surface. It is also possible to combine 21 sheets. The switch contacts 9, the circuit patterns 7 and the connector leads 8 on the fixed contact support plate 4 and the movable contact support plate 2 can be manufactured according to known techniques. The sandblasted surface decorative plate 21 is produced by spraying silica sand or the like at high speed on a polyester film so that the center line average roughness becomes 0.2 to 1.0 μm.

The transparent resin layer 22 is provided by applying it to the sandblasted surface decorative plate 21 by any means such as silk screen printing, gravure coating, roll coating, and bar coating. The thickness of the transparent resin layer 22 is preferably in the range of 0.1 to 4.0 μm. By providing this layer, the sandblasted surface of the decorative surface plate 21 exhibits the excellent texture and feel required for the membrane switch. Further, when it is desired to improve the touch feeling, a pigment may be contained. Furthermore, the polyester film usually does not adhere well to the ink for swelling printing, but if a polyester resin modified so that it easily adheres to the ink used is used, swelling printing on the pressed portion of the switch surface will also be good. The spacer 3 is provided by using a film in which a portion corresponding to a switch contact portion is punched out, or by printing ink on the fixed contact support plate 4 or the movable contact support plate 2 in the form of small protrusions by screen printing or the like.

[0008]

[Action]

 Since the membrane switch of the present invention uses the surface decorative plate 21 made of a polyester film having the transparent resin layer 22 on the sandblasted surface as the pressing surface, it is as good as the conventional embossed polycarbonate sheet. The texture and feel can be obtained, and the dimensional accuracy due to heat, which is a drawback of the embossed polycarbonate sheet, is significantly improved. Also, since it is sandblasted, scratches are not noticeable even if the switch is pressed many times. Also, when it is desired to make the pressing surface of the membrane switch convex, it is possible to carry out swelling printing without performing thermoforming.

[0009]

【Example】

 Embodiments of the present invention will be described below with reference to the drawings. FIG. 3 is a partial sectional view of a membrane switch for explaining one embodiment of the present invention. The membrane switch 1 includes, in order from the top, a movable contact support plate 2, a spacer 3 made of a film punched out at a portion corresponding to a switch contact, and a fixed contact support plate 4 having a switch contact 9 formed on its surface. The double-sided tape 5 and the separator 6 are sequentially laminated. The movable contact support plate 2 is composed of a raised print layer 24, a transparent resin layer 22, a front decorative plate 21, a back print layer 25, a double-sided tape 5, and a substrate film 23.

The surface decorative plate 21 is a 125 μm-thick polyester film that is sandblasted to have a centerline average roughness of 0.5 μm on one surface. The transparent resin layer 22 is prepared by diluting a polyester resin (SF primer 930: manufactured by Dainippon Ink & Chemicals, Inc.) with a mixed solvent consisting of ethyl acetate and anone. Isocyanate curing agent (CVL hardener # 10: Dainippon The coating liquid containing Ink Kagaku Kogyo Co., Ltd. is applied and dried by a bar coating method on the sandblasted surface of the surface decorative plate 21 so that the dry thickness is 1 μm. The raised print layer 24 is a raised print of the pressed portion and is formed on the transparent resin layer 22 by a silk screen printing method using an ultraviolet curable resist ink. The back surface printing layer 25 is printed on the surface opposite to the sandblasted surface of the surface decorative plate 21 by reverse printing the characters with white polyester ink and the other parts with black polyester ink by silk screen printing. There is.

In FIG. 1, a connector lead portion 8 is integrally formed on a substrate film 23, and a switch contact 9 and a circuit pattern 7 are formed on a polyester film by silk screen printing using a conductive paste ink. It is formed by printing by the method. The spacer 3 is formed of a polyester film having a punched portion corresponding to the switch contact. The fixed contact support plate 4 is integrally formed with a connector lead portion 8 similarly to the substrate film 23. These are formed by using a switch contact 9 and a circuit pattern 7 on a polyester film using a conductive paste ink. It is formed by printing with a silk screen printing method. Further, a double-sided tape 5 and a separator 6 are attached to the back surface of the fixed contact support plate 4 to facilitate the mounting of the membrane switch 1.

[0012]

[Effect of device]

 Since the membrane switch of the present invention uses a surface decorative plate made of a polyester film with a transparent resin layer on the sandblasted surface for the pressing surface, it has an excellent texture and feel comparable to conventional embossed polycarbonate sheets. It is possible to obtain a feeling and to remarkably improve the dimensional accuracy due to heat, which is a defect of the embossed polycarbonate sheet. In addition, since it is sandblasted, scratches are not noticeable even if the switch is pressed many times. Also, when it is desired to make the pressing surface of the membrane switch convex, it is possible to carry out swelling printing without performing thermoforming.

[Brief description of drawings]

FIG. 1 is an exploded perspective view showing an embodiment of a membrane switch of the present invention.

FIG. 2 is a partial cross-sectional view showing an embodiment of a surface decorative plate which is a part of the present invention.

FIG. 3 is a partial sectional view showing another embodiment of the membrane switch of the present invention.

[Explanation of symbols]

 1 ... Membrane switch 2 ... Moving contact support plate 3 ... Spacer 4 ... Fixed contact support plate 7 ... Circuit pattern 8 ... Connector Lead 9: Switch contact 21 .... Surface decorative plate 22 .... Transparent resin layer

Claims (1)

[Scope of utility model registration request] 1. A circuit pattern 7 and a connector lead 8 having a switch contact 9 formed on a fixed contact support plate 4.
A membrane switch 1 in which a switch contactor 9 is formed on a movable contact support plate 2 and a circuit pattern 7 and a connector lead portion 8 are provided so as to face each other with a spacer 3 in between. In the above, the movable contact support plate 2 has a surface decorative plate 21 made of a polyester film having a center line average roughness of 0.2 to 1.0 μm on the opposite surface of the switch contactor 9 by sandblasting, and A membrane switch having a transparent resin layer 22 on the sandblasted surface of the surface decorative plate 21.