| 摘要 |
PURPOSE:To enhance the utilization efficiency of light from a light projection means, by arranging the light projection means to the axis part of a slit member cooperated with an object to be detected and guiding light to the light receiving means in the opposite side from a slit through a reflective part. CONSTITUTION:A rod shaped rotary member 20 is attached to the rotary shaft 20b connected to an object to be detected and a slit 22b is formed to the leading end part of the rod shaped rotary member 20 and a first reflective part 21a, a light guide member 21 and a second reflective part 21b are provided to the slit 22b in order to guide light. Further, a light projection means 30 is provided on the axis of a rotary shaft 20b in opposed relation to the first reflective part 21a of the rod shaped rotary member 20 and a ring shaped light receiving means 40 is arranged at the position opposed to the slit 22b. An angle of rotation is detected from the position on the light receiving means 40 where light from the light projection means 30 arrives with the rotation of the rod shaped rotary member 20. |
