Sunarrow Limited

Takehiro Kaneko

A method is provided for marking a key top made of a translucent material with a character, a symbol, or the like, and a process is provided for quickly producing an illumination key unit. The inside of a transparent plastic key top is irradiated intermittently with focused laser light having a wavelength belonging to near infrared region of 1064 nm or less, visible region or near ultraviolet region to form an aggregation of multiple fine carbonization black points and an aggregation of points whitened by fine cracks or bubbling representing a character, a symbol, or the like. After a process capable of being carried out without determining a destination has ended, production is interrupted temporarily or ended and marking is performed by irradiating the top surface of the key top with laser light upon determination of a character, a symbol, or the like, related with the destination.

Process of producing key units wherein marking on their tops made of light-transmitting material can be completed later on

As a marking laser beam, a laser beam of wavelength 532 nm obtained by extracting by extracting second higher harmonic of the Nd:YAG laser or a laser beam of wavelength 355 nm obtained by extracting third higher harmonic of the Nd:YAG laser is used on a metal film formed on a plastic key top of a mobile telephone or the like, so that the metal film portion subjected to the beam is completely removed or only the surface portion of the metal film subjected to the beam is removed, thereby forming a planar set of very small concave points. Thus, it is possible to obtain a key unit having a metal film on which a character or symbol is directly marked.

Key unit, method for marking key top, and method for manufacturing key unit using the same

An end of the present invention is to make it possible to input multi-valued signals by a manipulation to incline a key in a multi-direction-operative key switch, and disclosed is a structure of a multi-direction-operative key fitting to the end of the present invention. The multi-direction-operative key includes: a key top made of hard resin; a key base made of rubber-like elastic body loading the key top on its surface; and a plurality of switch thrusting projections, each of which is made of the same material as that of the key base and extends vertically from a rear surface of the key base opposite to the surface loading the key top, wherein the switch thrusting projections are respectively provided at the position just below the center of the key top and at intersection points of a plurality of concentric circles surrounding the center of the key top and radii of the key top in its inclination directions, and lengths of the switch thrusting projections in the inclination directions are made to be different for the concentric circles.

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Souwa-machi, Japan

Takehiro Kaneko