Title:
MEASURING EQUIPMENT OF DISPLACEMENT INFORMATION
Document Type and Number:
Japanese Patent JP3548275
Kind Code:
B2
Abstract:
PURPOSE: To obtain a measuring equipment of displacement information which can detect information on the speed of a moving object with high accuracy by utilizing a Doppler effect.
CONSTITUTION: A light flux from a light source means is made incident on a diffraction grating 10 and two diffracted lights from the diffraction grating are cast on a moving object 7 through a first lens 11 and a second lens 12 by setting each element so that the two diffracted lights from different directions may intersect each other in the vicinity of the surface of the moving body. A scattered light from the surface of the moving body, which is subjected to a Doppler shift, is detected by a detecting means and information on the movement of the moving object is detected by using a Doppler signal obtained by the detecting means. On the occasion, an error in detection of the Doppler signal due to variation of the wavelength of the light flux from a light source 1 being consequent on a change in environment is corrected substantially by a change in a distance between the first lens 11 and the second lens 12 caused by thermal expansion consequent on the change in environment.
Inventors:
Shigeki Kato
Application Number:
JP13842995A
Publication Date:
July 28, 2004
Filing Date:
May 12, 1995
Export Citation:
Assignee:
Canon Inc
International Classes:
G01B11/00; G01P1/00; G01P3/36; G01S7/481; G01S17/58; G01S7/497; (IPC1-7): G01S17/58; G01P3/36
Domestic Patent References:
| JP6337337A | ||||
| JP4320079A | ||||
| JP518982A | ||||
| JP4230885A | ||||
| JP5577205U |
Attorney, Agent or Firm:
Yukio Takanashi
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