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:
Jun. 10, 1997
Filed:
Mar. 29, 1995
Applicant:
Inventor:
Hideaki Tamiya, Tokyo, JP;
Assignee:
Sony Magnescale Inc., Tokyo, JP;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
G02B / ;
U.S. Cl.
CPC ...
2502 / ; 25023116 ; 356356 ; 359566 ;
Abstract
A fixed point detecting device comprises a light source, a hologram disposed therebelow and having two portions, and two light receivers for detecting lights diffracted by the two portions of the hologram, wherein an angle of diffraction of light diffracted by one of the two portions of the hologram and an angle of diffraction of light diffracted by another of the two portions of the hologram have opposite signs and the same absolute value and are constant along the axis of measurement, and a difference in luminous intensity is great between positive and negative homogeneous lights diffracted by the two portions of the hologram.