| 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 has light-receiving element arrays L1 and L2, and receives light from an origin detecting pattern 5a. An origin signal generating circuit 20 generates an origin signal based on a reading result of the origin detecting pattern 5a. The light-receiving element array L1 has a light-receiving element PD11 for outputting a read signal S1, and a light-receiving element PD12 disposed in an x direction with respect to the light-receiving element PD11 for outputting a read signal S2. The light-receiving element array L2 has a light-receiving element PD13 for outputting a read signal S3, and a light-receiving element PD14 disposed in the x direction with respect to the light-receiving element PD13 for outputting a read signal S4. The light-receiving element array L2 is disposed in a y direction with respect to the light-receiving element array L1, and offset in the x direction. The origin signal generating circuit 20 outputs an origin signal that starts when the read signals S1 and S2 are at an equal level and terminates when the read signals S3 and S4 are at an equal level. |
