| 摘要 |
PROBLEM TO BE SOLVED: To obtain a stable switch operation by preventing production of an allophone like a whistle. SOLUTION: Air distribution slots 30 where air are made to flow according to an elastic deformation of each swelling part 12, are made on an undersurface of a rubber sheet 10 which has the swelling parts 12 of a shape like a dome in which the elastic deformation is possible, in four directions toward outside from the swelling part 12. Therefore, even if cross-sectional areas of the air distribution slots 30 in one direction become narrow with foreign matters such as a poor attachment of the rubber sheet 10, or a burr of the rubber sheet 10 or a switch substrate, air can be smoothly circulated through a 1st and a second air distribution slots 31 and 32 of other three directions. By this, while being possible to prevent production of the allophone like a whistle of the conventional example, the elastic deformation of each swelling part 12 can be carried out smoothly, and the switch operation can be stabilized. |
