Title:
【発明の名称】光学式エンコ―ダ
Document Type and Number:
Japanese Patent JP2539269
Kind Code:
B2
Abstract:
An optical encoder of the present invention includes a first diffraction grating and a second diffraction grating which is displaceable relative to the first diffraction grating to detect the relative displacement. The second diffraction grating has a grating pattern which removes a component having a period which is a factor of 1/n (n: a positive odd number) of the period of a displacement signal representing the relative displacement. In the optical encoder according to the present invention, higher harmonic components are cancelled by adding the amounts of light which passes through the grating portions whose phase differs by a predetermined distance. Consequently, a non-distorted displacement signal can be obtained.
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Inventors:
YASHIRO ATSUSHI
MATSUI KEIJI
MATSUI KEIJI
Application Number:
JP18387189A
Publication Date:
October 02, 1996
Filing Date:
July 17, 1989
Export Citation:
Assignee:
OOKUMA KK
International Classes:
G01D5/36; G01D5/38; (IPC1-7): G01D5/36
Domestic Patent References:
| JP6042616A |
Attorney, Agent or Firm:
Azusa Yuzo