| 摘要 |
PROBLEM TO BE SOLVED: To obtain an origin pulse signal from a wide origin signal in synchronous relation to an A/B phase pulse signal wherein a pitch is divided. SOLUTION: A sampling circuit 41 receiving the supply of an origin signal waveform wherein the waveform of the envelope of an origin detection signal is shaped, a sampling pulse generation circuit 42 for generating sampling pulses on the basis of A-phase and B-phase detection signals and a counter 43 for counting the number of times bringing the output of the sampling circuit 41 to an H-level are provided. A window operation/generation circuit 44 operates the position data of window pulses designating an origin position on the basis of the count value of the counter 43 and generates the window pulses based on the operation value and the specific position of an interpolation pulse signal wherein a phase between pitches is divided is extracted from a gate circuit 45 as an origin standard pulse by the window pulses outputted from the circuit 44.
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