Title:
POSITION DETECTING APPARATUS
Document Type and Number:
Japanese Patent JPH04130219
Kind Code:
A
Abstract:
PURPOSE:To make the positions of the original points of a plurality of parallel scales agree accurately by setting the phases shifting amounts of phase shifting circuits so that the phase amounts which are detected with first and second phase detecting circuits at the specified positions are made to be zero radian. CONSTITUTION:In a position detecting apparatus, the devices having the following functions are provided. A scale 1 has at least graduations 2 and 3 which are formed in parallel and have the different wavelengths. Phase detecting circuits 5 and 7 detect the phase amounts theta1 and theta2 of the graduations 2 and 3 in the scale 1. An absolute-position detecting circuit 8 detects the absolute position on the scale 1 based on the detected phase amounts theta1 and theta2. When an original point is set at an arbitray specified position S3 on the scale 1, the phase shifting amounts phi1 and phi2 of phase shifting circuits 10 and 11 are set so that the respective phase amounts theta1 and theta2 which are detected with the phase detecting circuits 5 and 7 at the specified position S3 are made to be zero radian. In this way, the specified position can be made to be the position of the original point on the scale 1.
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Inventors:
HIMURO AKIRA
KUSUMI MASAAKI
KUSUMI MASAAKI
Application Number:
JP25135490A
Publication Date:
May 01, 1992
Filing Date:
September 20, 1990
Export Citation:
Assignee:
SONY MAGNESCALE INC
International Classes:
G01B7/00; G01D5/244; G01D5/245; (IPC1-7): G01B7/00; G01D5/245
Domestic Patent References:
| JPS6439523A | 1989-02-09 | |||
| JPS57137095U | 1982-08-26 |
Attorney, Agent or Firm:
Hidekuma Matsukuma