US 9,752,901 B2 · Scale and optical encoder

Abstract

A scale and an optical encoder capable of maintaining an accuracy of a reference position irrespective of an error in attaching a detection head are provided. The scale according to the present invention is a scale including main-signal scale gratings having grating patterns of a predetermined pitch, and a reference-signal pattern, in which the main-signal scale gratings are arranged in parallel in a direction perpendicular to a length measurement axis of the main-signal scale gratings and are different from each other in phase by ½, and the reference-signal pattern is formed on the length measurement axis of the main-signal scale gratings. The optical encoder according to the present invention includes a light source, main-signal light source gratings, reference-signal light source gratings, main-signal receiver gratings, and a reference-signal receiver element.

Claims9

Dependent claims

A scale comprising first and second main-signal scale gratings having grating patterns of a predetermined pitch, and a reference-signal pattern, wherein:

each of the two main-signal scale gratings comprises transmitting parts and non-transmitting parts, the non-transmitting parts of each of the two main-signal scale gratings are arranged at the predetermined pitch in parallel to a length measurement axis of the scale, and the non-transmitting parts of the first main-signal scale grating are shifted by one half the predetermined pitch from the non-transmitting parts of the second main-signal scale grating, and
the reference-signal pattern is formed on a length measurement axis of the first main-signal scale grating and on a length measurement axis of the second main-signal scale grating.

Dependencies are inferred from the claim text.

Scale and optical encoder

Life of this patent

Scale and optical encoder

Life of this patent

Abstract

Claims9