| 摘要 |
PURPOSE:To make two switch operate reasonably in keying operation and obtain the touch response keyboard which can accurately detect the ON time difference between those switches. CONSTITUTION:A key 21 is supported so that it can rotate downward around the swing fulcrum 23 of its rear end part. On a printed board 31, the two switches 29 and 30 are provided on the surface facing the key. On the reverse surface of the key 21, a depression projection 28 having respective surfaces at specific tilt angles across a step part is formed integrally projecting from the key. The switch 29 is arranged opposite to the reverse surface 28a which is close to the swing fulcrum of the depression projection 28 and the other switch 30 is arranged opposite the reverse surface 28b which is distant from the swing fulcrum of the depression projection 28. In the keying operation, the key 21 rotates downward around the swing fulcrum 23 of the rear end part to turn ON the switch 29 close to the swing fulcrum of the key first and then turn ON the distant switch 30. |
