Teikoku Tsushin Kogyo Co., Ltd.

Atsushi Hari

Takashi Shinoki

Nobuyuki Yagi

Yasutoshi Kaku

Jiro Inagaki

Jiroh Inagaki

Shinji Mizuno

Nobuyuki Kikuchi

Yasuo Kojima

Tatsuya Okamura

Kimitane Kimura

A first film plateand a second film plate, each made of flexible resin film, are attached to a top surface and a bottom surface of a key topmade of mold-resin, respectively, so as to cover the key top. The first film plateis pressed upward to form a recessed portion, the key topis molded within this recessed portion. The second film plateis arranged on the bottom surface of the key top. All of the first film plate, the key top, and the second film plateare transparent. Decorative layersandare formed on the first film plateand the second film plate, respectively.

Key top plate

Key top plate and a method for manufacturing the same

A keytop sheet of a push-button switch includes a keytop made of synthetic resin that is molded on a sheet of resin film. A portion of the film sheet surrounding the portion thereof on which the keytop is molded is provided with a curved projection protruding in a downward and/or upward direction from the surface of the film sheet. Such curved projection can be replaced by providing the portion of the film sheet surrounding the portion thereof on which the keytop is molded with a cut-out to form a hinge portion. A nameplate provided with a hole shaped so that the keytop may be passed therethrough is attached to the film sheet so as to cover the cut-out and hinge portion of the film sheet. The nameplate can have an outer diameter greater than that of the film sheet. A frame made of synthetic resin is fixed to an underside of the film sheet on an outer peripheral portion thereof. An outer peripheral portion of the nameplate is bent and fixed to an outer peripheral side surface of the frame.

Method of manufacturing a framed keytop sheet for a push-button switch

A method of enlarging a design possessed by a synthetic resin film includes a printing step of printing the design on the top side of the synthetic resin film, and an enlarging deformation step of providing a curved portion by stretching a prescribed surface of the synthetic resin film which includes a portion on which the design has been printed and curvingly deforming the prescribed surface in such a manner that the surface will protrude above the plane defined by the synthetic resin film. The design printed on the synthetic resin film beforehand in the printing step is printed in dimensions conforming to the rates of enlargement of points on the curved portion of the synthetic resin film. A portion of the design having a small rate of enlargement is printed at relatively large dimensions in comparison with other portions thereof and a portion of the design having a high rate of enlargement is printed at relatively small dimensions in comparison with other portions thereof.

Method of enlarging design provided on a synthetic resin film

A keytop sheet of a push-button switch includes a keytop, which is made of synthetic resin, molded on a sheet of resin film. A portion of the film sheet surrounding the portion thereof on which the keytop is molded is provided with a curved projection protruding in a downward and/or upward direction from the surface of the film sheet. Alternatively, a cut-out separates the portion of the film sheet on which the keytop is molded from the remainder of the film sheet while leaving a hinge portion, and a nameplate through which the keytop passes is attached to the film sheet so as to over the cut-out and hinge portion of the film sheet. The nameplate may have an outer diameter greater than that of the film sheet, and a frame made of synthetic resin is fixed to an underside of the film sheet on an outer peripheral portion thereof. The outer peripheral portion of the nameplate is bent and fixed to an outer peripheral side surface of the frame.

Keytop sheet for push-button switches

A push-button switch keytop includes a flexible resin film deformed in such a manner that the resin film bulges upwardly to form a curved portion that is filled with a molding resin while the resin film is being deformed. The molding resin is allowed to harden to form a keytop body, whereby the top side of the keytop body consisting of the molding resin is integrated with the resin film in a state in which the top side of the keytop body is covered by the resin film. The keytop is manufactured by clamping a resin film between upper and lower molds, charging a molten resin from a pin gate provided on the lower mold into a cavity provided in the lower mold, thereby deforming and urging the resin film upward by pressure and heat produced by the molten resin and causing the resin film to adhere to the inner surface of the upper mold, filling the cavities of the upper and lower molds with the molten resin and separating the upper and lower molds after the resin hardens. An adhesive layer may be provided directly or indirectly via another printed layer on the underside of the resin film on that portion thereof where the keytop is located.

Keytop for push-button switches, and method of manufacturing same

The keytop of a push-button switch includes a keytop portion situated on the top of a resin film, and a retaining portion situated on the underside of the resin film. The keytop portion and retaining portion are formed into a unitary body by a resin-molding process in which resin is passed through a hole provided in the resin film such that the resin film is sandwiched between the keytop portion and the retaining portion. In another embodiment, the retaining portion is loop-shaped and is formed into a unitary body with the keytop portion by a resin-molding process in which the resin passes through a plurality of holes provided in the resin film in a pattern corresponding to the loop-shaped circumference of the retaining portion. The resin film is sandwiched in a water-tight state between the keytop portion and the loop-shaped retaining portion.

Growing community of inventors

Kanagawa, Japan

Atsushi Hari