| 摘要 |
PURPOSE:To obtain a contactless rotary switch with the use of an optical signal by providing the 1st photodetection section where a polizer is fitted to a rotary shaft and light is received via the polarizer and the 2nd photodetection section where light is received by a polarizer and an analyzer. CONSTITUTION:The rotary shaft 1 is turned by 90 deg. at the operation of a switch device and the polarizer 7 is provided incorporatedly thereto. A light shield package 8 is provided with light emitting elements 9, 10, photodetectors 11, 12 and the analyzer 13 as shown in figure fixedly. When the switch is opened, the polarizer 7 in the relation among the light emitting elements, polarizers, analyzers and photodetectors as shown in figure (a), polarizes the light from the photodetectors 9, 10 toward left/right directions shown in figure (b), the photodetecting direction of the photodetection section 13 is in up/down direction, then the difference in the output signals of the photodetector 11, 12 is 0, which shows that the switch is opened. When the switch changes to the closing state, the rotary shaft 1 is turned by 90 deg., each element is in the state shown in figure (c), the difference in the output signals of the photodetectors 11, 12 is a prescribed value, which shows that the switch is closed. |
