US 12,188,768 B2
Angle detector and position measuring device
Shunsuke Tanaka, Kanagawa (JP); Yoshiaki Kato, Kanagawa (JP); and Miyako Mizutani, Kanagawa (JP)
Assigned to MITUTOYO CORPORATION, Kawasaki (JP)
Filed by MITUTOYO CORPORATION, Kanagawa (JP)
Filed on Aug. 25, 2022, as Appl. No. 17/895,267.
Claims priority of application No. 2021-151153 (JP), filed on Sep. 16, 2021.
Prior Publication US 2023/0082750 A1, Mar. 16, 2023
Int. Cl. G01B 7/30 (2006.01); G01B 11/26 (2006.01); G01D 5/20 (2006.01)
CPC G01B 7/30 (2013.01) [G01B 11/26 (2013.01); G01D 5/20 (2013.01)] 11 Claims
OG exemplary drawing
 
1. An angle detector comprising:
a rotary scale having a scale pattern in which a plurality of patterns are arrayed along a circumference direction of the rotary scale; and
a plurality of detection heads, each of which detects the plurality of patterns from the scale pattern,
wherein the plurality of detection heads are shifted from each other in the circumference direction of the rotary scale and are shifted from each other in a radial direction of the rotary scale,
wherein the rotary scale has a plurality of tracks, each of which has a plurality of patterns arrayed along the circumference direction of the rotary scale and is shifted from each other in a radial direction of the rotary scale, and
wherein at least two detection heads of said plurality of detection heads are arranged on each of the plurality of tracks, and in at least two of the plurality of tracks, a pair of the detection heads among the plurality of detection heads arranged on the same track are arranged opposite to each other with a 180° separation between them.