| 摘要 |
PROBLEM TO BE SOLVED: To prevent the deformation and breakage of a switch housing by installing a buffering part on a part of the wall surface of the switch housing and absorbing a pressure difference by the buffering part even in the case the internal pressure of the switch housing changes caused by an expansion difference between the content volume of the switch housing and refractive index matching agent in accordance with the change in temperature. SOLUTION: An opening part 10 and a diaphragm 2 as the buffering part are arranged on the upper surface of the switch housing 1. The diaphragm 2 is made of a thin rubber film, and the diaphragm 2 is freely sifted inward and outward in accordance with the fluctuation of the internal pressure of the switch housing 1. Thus, when an ambient temperature changes, the refractive index matching agent expands equal to or exceeding the expansion amount of the content volume of the switching housing 1, then, the internal pressure of the housing is increased. Thus, the internal pressure is applied on the internal surface of the diaphragm 2, then, the diaphragm 2 is pressed against the outside where the pressure (air pressure) is low as much as the increase of the internal pressure, then, the diaphragm expands by the time the internal pressure is balanced with the external pressure. Thus, the expansion difference caused by the temperature increase is absorbed, and the deformation and breakage of the switch housing 1 are prevented. |
