| 摘要 |
PROBLEM TO BE SOLVED: To provide a rotational position detection device which is reasonably configured and achieves high reliability.SOLUTION: A rotational position detection device includes: a light emitting element 110 and a light receiving element 120 both mounted on a circuit board 300; and a light guide 130. The rotational position detection device is arranged so that a rotating body 10 is positioned in a path A of light emitted from the light emitting element 110. According to rotation of the rotating body 10, a transparent portion 11, provided on the rotating body 10, crosses the path A of the light, so that a rotational position of the rotating body 10 is detected. A case body 200 includes a first case component 210 and a second case component 220 which hold the rotating body 10 in between at both sides of the rotating body 10 in its rotation axis direction. The circuit board 300 is provided in the first case component 210, and the light guide 130 is provided in the second case component 220. In at least one of the first case component 210 and the second case component 220 is provided pipe sections 210a and 220a which protrude toward other one of the first case component 210 and the second case component 220. Further, the path A of the light passes through the inside of the pipe sections 210a and 220a. |
