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:
Jul. 11, 1989
Filed:
Mar. 11, 1988
Applicant:
Inventors:
Takanori Maeda, Saitama, JP;
Susumu Nomura, Saitama, JP;
Assignee:
Pioneer Electronic Corporation, Tokyo, JP;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
G01J / ;
U.S. Cl.
CPC ...
250201 ; 369 45 ;
Abstract
A focus error detecting apparatus is improved by splitting the light detector into three portions, with a first portion located between second and third portions and being elongated. The elongation prevents an out-of-focus condition where the detection light spot is elliptically elongated in the elongation direction from being falsely detected as the focused condition.