| 摘要 |
PURPOSE:To perform accurate detection by providing the 1st and 2nd zones of different widths with respect to the rotating directions to part of a rotator, and detecting the rotating directions from the patterns detecting the passage thereof. CONSTITUTION:A cut plate 6 is provided on the circumferential surface of a pulley 3 which is driven via a belt 5 by a motor 2. Said cut plate 6 consists of the 1st zone 6b and the 2nd zone 6c having different widths W1, W2 with respect to rotating directions A, B. Two pairs of light emitting elements 9, 9' and two pairs of photodetectors 10, 10' are provided to a holder 7 in the positions corresponding to the 1st zone, 2nd zone 6b, 6c of the cut plate 6. The rotating directions are detected by the signals of different pulse widths correspondig to the 1st zone, 2nd zone 6b, 6c from the photodetectors 10, 10'. |
