| 摘要 |
PURPOSE:To sense the motion of a key accurately by furnishing the key with a plurality of shutters, and emitting the key pushing speed in compliance with the change in the sensing signals given by sensors furnished along the shutter moving path. CONSTITUTION:A key shutter 52 is fixed to the undersurface of a key 50, and one corner of the shutter under-part is notched rectangularly, where end faces 52a, 52b in stepped form are provided, and a rectangular through hole is furnished over the end face 52a, and the through hole undersurface 52c and through hole oversurface 52d are formed. A sensor part 54 is equipped with photo- interrupters 56, 58 which face the swing paths for the end faces 52a, 52b of the shutter 52. When the key 50 is depressed, the photo-interrupter 56 is turned off by the end face 52a, and if further pushed deeply, the photo-interrupter 56 passes the through hole undersurface 52c to be turned on, and then the photo- interrupter 58 is turned off by the end face 52b, and if further pushed deeply, the photo-interrupter 58 is turned off by the through hole oversurface 52d. |
