| 摘要 |
<p>A key 11 is supported by key supporting portions 32 so that the key 11 can pivot. A reaction force generation member 22 is shaped like a dome to be elastically deformed by a key-depression of the key 11. At the time of the elastic deformation, the reaction force generation member 22 increases a reaction force from the beginning with an increasing amount of elastic deformation. After the reaction force reaches its peak, the reaction force generation member 22 buckles to reduce the reaction force. A normal line of a plane P1 including a pivot axis C of the key 11 and a depression point of a depression portion 11a is designed to be roughly parallel to an axis line Y1 of the reaction force generation member 22 at the point in time when the reaction force of the reaction force generation member 22 reaches its peak.</p> |
