| 摘要 |
PROBLEM TO BE SOLVED: To provide a position detecting encoder enabling position detection with few errors even if a scale and a sensor relatively move.SOLUTION: A position detecting encoder has a scale 10 having first and second periodic patterns 11 and 12; a sensor 20 which can be switched between a first detection state in which the first periodic pattern is read to output a first periodic signal and a second detection state in which the second periodic pattern is read to output a second periodic signal; and a processing portion 30 for calculating positions in a relative moving direction of the scale and the sensor by using the first and second periodic signals. The processing portion takes in the first periodic signal at specific time, calculates a phase at the specific time of the first periodic signal, takes in the first and second periodic signals at time after that, calculates phases at the specific time of those periodic signals, and calculates position at the specific time by using the calculated phases at the specific time. |
