ROTARY ENCODER AND METHOD FOR ASSEMBLING ROTARY ENCODER

摘要

PROBLEM TO BE SOLVED: To obtain a rotary encoder which allows easy centering of a rotary scale and a hub to facilitate assembling both of them with high accuracy.

SOLUTION: A rotary encoder includes: a rotary scale which has a continuous pattern and a prescribed pattern including a rotation angle origin formed with a pattern center as a reference and has a polygonal external shape, where the rotation angle origin is determined on the basis of at least one of sides of the polygonal shape; a hub including projections which are in contact with sides of the external shape of the rotary scale and are provided for positioning to the rotary scale; a rotating shaft which is press-fitted to the hub and rotates concentrically with the pattern center of the rotary scale; and detection means which irradiates the rotary scale with light and detects the light passed through the rotary scale.

COPYRIGHT: (C)2012,JPO&INPIT