| 摘要 |
PURPOSE:To increase the resolution by a multiple of 2N in comparison with a conventional encoder by giving 2N-phase of position signals whose phases are shifted by 90/2N degrees each to N-stage of resolution fractionating circuits each having an exclusive OR circuit. CONSTITUTION:Slits of a prescribed interval are provided on a circumference having a prescribed radius from the center of a rotary disk, four detectors are provided to four positions on the circumference of the rotary disk provided with the slits (positions deviated by 45 deg. each with respect to the interval of the slits), and a four phase position signal whose phase is shifted by 45 deg. each is outputted from the four detectors through the detection of the slits when the rotary disk is driven. Let a phase of the output signal in giving signals of phases A, C to the input of the exclusive OR circuit 1 be the phase AC, and the phase of the output signal in giving the signals of the phases B, D to the input of the exclusive OR circuit 1 be the phase BD, then the phases AC, BD of the signals are shifted by 90 deg. each, the period is halved by the phases A-D, and in using the signals of the phases AC, BD as position signals, the resolution being a multiple of twice that of a conventional rotary encoder is obtained. |
