Kith itch and

摘要

PROBLEM TO BE SOLVED: To make a keyboard compact, and to inhibit the deformation and damage to membrane sheet itself in accompany with the continuous pushing, by forming an elastic member for returning a kep top to an original position, by a sheet which is streached by a link mechanisms near the both edges, corre sponding to a point edge face of a projection for pressing the key top. SOLUTION: A rubber sheet 214 of a rectangular elastic body of which the holes of four corners are to be fitted into the projections for stretching the rubber sheet, which are formed on the upper faces of the connecting parts of two links with gears, of a link mechanism with gear 213, is streatched by the link mechanism with gear 213. The rubber sheet 214 to be lowered by the pressing of the key top 214 having a long circular projection 215a on an inner central part, is opened by the movement of the link with gear, and a switching area of the membrane sheet 121 is pushed to be connected. The width of the rubber sheet 214 is corresponding to the size of the switching area, so that a pitch between the areas can be reduced, and the continuous pressing of the membrane sheet 121 by the rubber sheet 213 can be prevented.