PURPOSE: To provide the rotating angle detector capable of assuring a wide linearly changing region.
CONSTITUTION: This rotating angle detector has photosensor units 23A, 23B in which light emitting elements 21A, 21B and light receiving elements 22A, 22B are disposed to face each other via gaps 20 serving as optical paths held therebetween and a light shielding plate 25 which is supported by a revolving shaft 24 and oscillates and rotates between the gaps. The detector descried above detects a rotating angle by the output change of the light receiving elements. An oscillation center O2 of light shielding ends 26A, 26B is positioned at an arbitrary distance from the center O1 of the light receiving surfaces of the light receiving elements 22A, 22B and an oscillatory rotating center O of the light shielding plate 25 is positioned on a segment orthogonal with a segment connecting the center O1 of the light receiving surfaces and the oscillation center O2. The light shielding ends 26A, 26B are formed to an arc shape or inverted arc shape having its radius at the length of the segment connecting the center O1 of the light receiving surfaces and the oscillation center O2. As a result, the detector is no longer restricted by mounting fittings, etc., of the light shielding plate 25 and the wide linearly changing region is assured.
HIZUME HIROYASU
KATSUMATA HIROSHI
