The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Mar. 12, 1996
Filed:
Apr. 13, 1994
Applicant:
Inventor:
Hideaki Tamiya, Yamato, JP;
Assignee:
Sony Magnescale Inc., Tokyo, JP;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
G01B / ;
U.S. Cl.
CPC ...
356356 ; 356351 ;
Abstract
In an instrument and method for optically measuring a displacement of a scale which can achieve the noise elimination of returning light to a coherent light source, the scale and optical system are so constructed that an intersecting point of light fluxes radiated from the coherent light source and split into those fluxes by means of a first beam splitter is not present on a transmitting type diffraction grating and the incident lights (d, e) on a reflecting plate and the reflected lights (f, g) from the reflecting plate have no common use of the same light paths.