| 摘要 |
PURPOSE:To enhance the resolving power in the detection of an absolute position, by providing (n-1) vernier slits corresponding to (n) slits for detecting the lowest rank bits on a slit disk so as to superpose the same under said detecting slits. CONSTITUTION:A disk 20 having slits is provided to an input shaft 2 concentrically and light emitting elements 3 and light receiving elements 4 are provided to the back and front sides of said disk 20 so as to form a pair with respect to each of slits. A BS disk 8 provided with (n-1) vernier slits (BS) corresponding to (n) the lowest rank bit detecting slits (LSBS) on the disk 20 is arranged so as to be superposed under LSBS. When the input shaft 2 is rotated, output corresponding to the angle of rotation appears in outputs 6, 7. That is, No.1, No.2 and No.3 vernier slits are respectively superposed at positions (1), (2), (3) in the highest degree. By this method, a position 1/(n-1) the interval of LSBS is calculated and resolving power is enhanced by (n-1) times. |
