ROTARY ENCODER, ROTARY MOTOR AND ROTARY MOTOR SYSTEM

摘要

Provided are a rotary encoder, a rotary motor and a rotary motor system in which the origin of a position can be detected with improved detection precision by utilising diffraction interference light, and in which reduction in size and manufacturing etc. are facilitated. An encoder comprises: a circular plate-shaped disk (110) which is rotatably arranged about an axis of rotation, which has one ring-shaped track (TC) having rotary gratings respectively formed therein, and which has one or more origin detection regions (h) formed in a section thereof; and a mask which is arranged in fixed manner facing the disk (110) and has one or more fixed gratings formed therein so as to construct a diffraction interference light system with the rotary gratings. A plurality of slits (SLA, SLB) included in at least one of the rotary gratings is formed along curved lines that are formed by bending a plurality of radial lines, which are centred about the axis of rotation, in the circumferential direction with a prescribed degree of curvature; the slits (SLA, SLB) are formed in such a way that the pitches (pLA, pLB) of the slits (SLA, SLB) can be set to prescribed values.