Abstract: In a keytop in which a mark indicating a function of the corresponding key switch is printed on the top surface of a keytop body made of a synthetic resin, the mark being a letter, a character, a numeral, a word, a symbol, a sign, a figure, a pattern or the like, or any combination thereof, and the mark is coated with a resin coating, a transparent or semitransparent coating that is soft, not slippery, and lusterless, is applied on the whole surface of the keytop body including the resin coating. Such transparent or semitransparent coating gives a soft feeling to the tip of an operator's finger as well as the tip thereof is hard to slip off the keytop, and hence the feeling thereof on operation is comfortable and the operativity thereof is satisfactory. Moreover, a line of the contour of the resin coating becomes disappeared and it is possible to completely take off the luster thereof. Accordingly, a grade in the external appearance of the keytop can be improved.

Abstract: In a keytop in which a mark indicating a function of the corresponding key switch is printed on the top surface of a keytop body made of a synthetic resin, the mark being a letter, a character, a numeral, a word, a symbol, a sign, a figure, a pattern or the like, or any combination thereof, and the mark is coated with a resin coating, a transparent or semitransparent coating that is soft, not slippery, and lusterless, is applied on the whole surface of the keytop body including the resin coating. Such transparent or semitransparent coating gives a soft feeling to the tip of an operator's finger as well as the tip thereof is hard to slip off the keytop, and hence the feeling thereof on operation is comfortable and the operativity thereof is satisfactory. Moreover, a line of the contour of the resin coating becomes disappeared and it is possible to completely take off the luster thereof. Accordingly, a grade in the external appearance of the keytop can be improved.

Abstract: In a keyboard that comprises a membrane switch sheet having switch portions arranged all over it, a keyboard substrate and a keyboard frame having sandwiched therebetween the membrane switch sheet to provide therein rigidity, and actuators for ON/OFF control of the switch portions through openings made in the keyboard frame, the keyboard substrate and the keyboard frame are each formed by a thin aluminum sheet, the membrane switch sheet has plural through holes, and plural trapezoidal bumps or protrusions formed by stamping the keyboard substrate toward the keyboard frame are inserted through the plural through holes into surface-to-surface contact with the keyboard frame, the plural trapezoidal bumps being spot-welded in their flat top surfaces to the keyboard frame.

Abstract: In a keyboard switch including a pantograph mechanism comprising a U-shaped link 14 having a pair of stud shafts 14C rotatably and movably supported in bearing portions 13B of a base 13 and a link 15 including a frame-like portion 15A and having a pair of stud shafts 15D rotatably supported in bearing portions 13C ofthe base 13, ribs 14F having tapered surfaces 14G are provided along the peripheral surfaces of bosses 14D defining the center of rotation of the link 14 while holes 15E in the link 15 for mating with the bosses 14D are formed with keyways 15F. When a force tending to pull the keytop up further from it returned original position is applied to the keytop, the tapered surfaces 14G and the angular edges of the keyways 15F are forced into contact with each other. This urging force in turn urges the opposed legs 14B of the link 14 to expand apart from each other in the directions indicated by the arrows 19, whereby the link 14 is prevented from dislodging from the base 13.

Abstract: In a keyboard that comprises a membrane switch sheet having switch portions arranged all over it, a keyboard substrate and a keyboard frame having sandwiched therebetween the membrane switch sheet to provide therein rigidity, and actuators for ON/OFF control of the switch portions through openings made in the keyboard frame, the keyboard substrate and the keyboard frame are each formed by a thin aluminum sheet, the membrane switch sheet has plural through holes, and plural trapezoidal bumps or protrusions formed by stamping the keyboard substrate toward the keyboard frame are inserted through the plural through holes into surface-to-surface contact with the keyboard frame, the plural trapezoidal bumps being spot-welded in their flat top surfaces to the keyboard frame.

Abstract: In a keyboard switch including a pantograph mechanism comprising a U-shaped link 14 having a pair of stud shafts 14C rotatably and movably supported in bearing portions 13B of a base 13 and a link 15 including a frame-like portion 15A and having a pair of stud shafts 15D rotatably supported in bearing portions 13C of the base 13, ribs 14F having tapered surfaces 14G are provided along the peripheral surfaces of bosses 14D defining the center of rotation of the link 14 while holes 15E in the link 15 for mating with the bosses 14D are formed with keyways 15F. When a force tending to pull the keytop up further from it returned original position is applied to the keytop, the tapered surfaces 14G and the angular edges of the keyways 15F are forced into contact with each other. This urging force in turn urges the opposed legs 14B of the link 14 to expand apart from each other in the directions indicated by the arrows 19, whereby the link 14 is prevented from dislodging from the base 13.

Abstract: A pattern sheet, an insulation sheet and a frame made of sheet metal are successively built up on a plate made of sheet metal, a pair of links pivotally connected together intermediate their opposite ends to form a pantograph mechanism are movably engaged at their one ends with respective bearings formed on the frame by a drawing process while the other ends of the links are movably engaged with respective bearings formed on the bottom surface of a key top.

Abstract: In a keyboard which drives membrane switches by selectively depressing key tops, hinge portions are formed integrally with a housing in an array of hinge receiving holes made therein in correspondence with a desired array of key tops, a top panel having openings corresponding to the hinge receiving holes is bonded to the top of the housing and the key tops are each disposed to cover the corresponding opening and the entire length of the corresponding hinge portion and is fixedly engaged with the free end of the hinge portion through the opening. By the application of pressure to and its removal from each key top, the lower end of the free end of the corresponding hinge portion operates to make and break the underlying membrane switch.

Abstract: In a pantograph type keyboard switch, a leaf spring projects from a linkage member and slidably engages the underside of a keytop and the resulting reaction force is used to remove play between the keytop and the linkage member. Further, a frictional slope is formed in each slide groove in the underside of the keytop so that frictional force increases as the keytop approaches the top dead point position.

Abstract: In a keyboard which drives membrane switches by selectively depressing key tops, hinge portions are formed integrally with a housing in an array of hinge receiving holes made therein in correspondence with a desired array of key tops, a top panel having openings corresponding to the hinge receiving holes is bonded to the top of the housing, and the key tops are each disposed to cover the corresponding opening and the entire length of the corresponding hinge portion and is fixedly engaged with the free end of the hinge portion through the opening. By the application of pressure to and its removal from each key top, the lower end of the free end of the corresponding hinge portion operates to make and break the underlying membrane switch.

Abstract: In a pantograph type keyboard switch, a leaf spring projects from a linkage member and slidably engages the underside of a keytop and the resulting reaction force is used to remove play between the keytop and the linkage member. Further, a frictional slope is formed in slide grooves in the underside of the keytop so that frictional force increases as the keytop approaches a top dead point.