JP3040415U - Surface sheet for membrane switch - Google Patents

Abstract

(57) [Abstract] [Problem] The cost can be reduced by uniformly coating and eliminating the need for a rubber molding die, and the base thickness can be made thin, and the click feeling is good, and deformation is possible. A surface sheet for membrane switches that is durable and has a high-class feel. SOLUTION: A multi-layer film in which a plastic film and an elastic thin film are adhered is used, and a plastic film surface of the multi-layer film is used as a back surface, and characters are provided on the back surface side.
A surface sheet for membrane switches that is embossed with this multilayer film after printing design such as symbols.

Description

[Detailed description of the invention]

[0001]

[Technical field to which the invention belongs]

 The present invention relates to a membrane switch used for a switch section of electronic and electric parts such as a telephone, an audio device, a television, a video, a facsimile, a copying machine and an in-vehicle device.

[0002]

[Prior art]

 The membrane switch, which uses a plastic film as the material, is embossed in a dome shape to give a click feeling and a design-like three-dimensional effect.

However, the plastic film lacks a high-class feeling, and the tactile feeling at the time of switching has no elastic feeling.

Therefore, a material whose surface is processed into a mat-like shape has been put on the market, but it still lacks a high-class feeling. Therefore, the following has been attempted in order to express the high-class feeling of the membrane switch and to improve the tactile sensation.

B. Combination of rubber molded product and membrane switch b. Method of laminating rubber by painting after embossing plastic film c. Use rubber sheet instead of plastic sheet

[0006]

[Problems to be solved by the device]

 However, these conventional methods have the following drawbacks.

In the method of combining the rubber molded product and the membrane switch, a separate mold for rubber molding is required, which requires an initial cost. Also, since the rubber base thickness needs to be around 0.7 mm, the base thickness of the product becomes thicker, and it is not possible to make it thinner, which is a feature of the membrane switch.

The method of laminating the rubber by painting after embossing the plastic film is a method of swelling the plastic film, the flow of the paint due to the shape of the convex film, cissing of the rubber paint on the plastic film, and the like. The gap between the spaces is not evenly painted, making it unsightly. In addition, painting is costly due to the large loss of materials. Since heating is required to dry the rubber paint, this causes the embossed shape to be deformed by heat, which makes the switch feel uncomfortable.

In the case where the rubber sheet is used instead of the plastic sheet, since the rubber sheet is soft, there is no click feeling and the embossed shape is easily deformed.

[0010]

[Means for Solving the Problems]

 INDUSTRIAL APPLICABILITY The present invention can reduce the cost by using a multilayer film of a plastic film and an elastic thin film body so that the coating can be performed uniformly at the time of manufacturing, and a mold for rubber molding is unnecessary. (EN) Provided is a surface sheet for a membrane switch, which can be made thin because it can be made thin, has a good click feeling, is durable without being deformed, and has a high-grade feeling.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION

 A multi-layer film in which an elastic thin film body of silicone rubber with a thickness of 5 to 500 μm is adhered to a plastic film with a thickness of 10 to 200 μm is used, with the plastic film side as the back side and letters, symbols, etc. on the back side. Print the design. After that, this is embossed with an embossing mold. If the plastic film is thinner than 10 μm, the strength is insufficient and the function as a switch cannot be obtained. Also, with a plastic film thicker than 200 μm, the rigidity is high and the input load becomes high. If the thickness of the elastic thin film is less than 5 μm, the tactile sensation of rubber cannot be obtained, and at the same time, the strength of the elastic thin film is low and it cannot be used. If the thickness is more than 500 μm, the elastic thin film body may not be clearly visible on the back side of the printed pattern, resulting in inconvenience in actual use.

The finished product had a clear click feeling without deformation of the embossed shape, and the load was a switch having an input load of 50 g to 300 g most suitable for human operation. In addition, the feel was rubbery, and the appearance was more luxurious than before. With this structure, a thin switch having a base thickness of about 0.6 mm was obtained.

In order to increase the surface hardness, the surface of the silicone rubber may be further hard-coated.

A detailed description will be given below with reference to embodiments.

[0015]

Example 1 From the back surface on the PET film side of a multilayer film (made by Kureha Elastomer Co., Ltd .: trade name [Tera Cracun]) of a 100 μm thick polyethylene terephthalate (PET) film 1 and a 25 μm thick silicone rubber 2, I did design printing of letters, symbols, etc. 3. In order to give a more click feeling, the part that becomes the switch was embossed using a publicly known technique using a mold.

In addition to the above products, the laminated film may be a rubber sheet laminated with an adhesive or a film with a double-sided tape.

Reference numeral 4 is a membrane switch.

[0018]

Example 2 When a convex mark is added to the apex of the key, design printing 3 is performed from one side of the PET film of the same multilayer film as in Example 1, and then the adhesive force from the rubber surface is taken into consideration. Convex printing 5 was performed using a silicone rubber-based ink. In order to make this feel even more clickable, the part that becomes the switch is embossed. At this time, the convex may be added after the embossing, and the jig may be used with a dispenser.

[0019]

[Effect of the invention]

 By using the present invention, it is possible to provide a low-cost thin switch with a base thickness of about half that of the conventional type, which has a rubber-like feel and does not impair luxury.

[Brief description of the drawings]

[Figure 1] Switch cross section

FIG. 2 is a sectional view of another embodiment.

[Explanation of symbols]

 1 PET film 2 Silicone rubber 3 Design printing layer 4 Membrane switch 5 Convex printing

Claims (2)

[Utility model registration claims] 1. A multilayer film in which a plastic film having a thickness of 10 to 200 μm and an elastic thin film having a thickness of 5 to 500 μm are adhered is used, and the plastic film surface of the multilayer film is used as a back surface, and the back surface side thereof is used. A surface sheet for a membrane switch, which is obtained by embossing this multi-layer film after design printing of letters, symbols, etc., and having a thin click feeling and a rubber touch feeling. 2. The plastic film is selected from polyethylene terephthalate film, polyethylene naphthalate film, polycarbonate film, polyimide film, polyether sulfone film, and the elastic thin film body is natural rubber, silicone rubber, urethane rubber, ethylene propylene rubber, Claims selected from isoprene rubber, butadiene rubber, styrene butadiene rubber, acrylonitrile butadiene rubber, chloroprene rubber, butyl rubber, fluorine rubber, chlorosulfonated polyethylene rubber, chlorinated polyethylene rubber, acrylic rubber, epichlorohydrin rubber and blended rubbers thereof. The surface sheet for a membrane switch according to 1.