| 摘要 |
PURPOSE:To make the configuration compact and to improve accuracy, by arranging at least two signal reading means, and reading the signals of signal tracks at a plurality of places. CONSTITUTION:In the case of a rotary encoder application, two signal reading means 13 and 14 are arranged at positions, which are separated by 180 deg., on a signal disk 11, on which signal zones 12 of two tracks are formed. Two parts, whose optical properties are different, are provided in the zones 12, and the position-data signals in the total of 4 bits are obtained. Each track pattern is formed by 12 kinds of signals except for the symmetrical bits on the right and left sides. Thus the absolute position of rotation can be determined in a single sense. Since the resolution can be improved and the means 13 and 14 can be arranged on the same circumference, the configuration can be made compact. |
