| 摘要 |
PROBLEM TO BE SOLVED: To generate an origin signal with high accuracy using a simple configuration.SOLUTION: An origin detecting light-receiving section 11 receives light at light-receiving elements PD11-PD15 from an origin detecting pattern 5a. The light-receiving element PD11-PD15 are arranged in an x direction, and output read signals S11-S15. An origin signal generating circuit 20 outputs an origin signal that starts a signal obtained by adding the read signal S11 and the read signal S12 and a signal obtained by adding the read signal S13 and the read signal S14 are at an equal level, and ends a signal obtained by adding the read signal S12 and the read signal S13 and a signal obtained by adding the read signal S14 and the read signal S15 are at an equal level. |
