| 摘要 |
PROBLEM TO BE SOLVED: To provide a position detector which exactly detects the positions of moving members by using simple devices. SOLUTION: This position detector has a ratchet wheel 103 which has three opposite sections (gray pattern 103g, white pattern and black pattern) to generate pulse signals by advancing and retreating to and from the front of a photoreflector 150 by accompanying the movement of a planetary gear 104 moving to plural positions and to vary incident light quantities from each other and a non-return lever 110 and a CPU 1 which is a control means to be made changeable to first and second detection levels for comparison with the output value of the photoreflector 150, to detect and judge the relative positions of the planetary gear 104 by the first detection level (white pattern detection level) and to check and judge the presence of the planetary gear 104 in the prescribed position as the absolute position by the second detection level (gray pattern detection level). |
