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. 09, 1991
Filed:
Jun. 07, 1989
Yorihiko Sakai, Tokyo, JP;
Yasushi Ota, Sendai, JP;
Dai Nippon Insatsu Kabushiki Kaisha, Tokyo, JP;
Abstract
A defect detection system detects defective portions such as scratches, pinholes and dust on a pattern formed surface of a medium such as an optical card, optical disk, holographic memory medium or photomask, on which fine patterns are formed. A light source irradiates a controlled ray to a recording portion as an object of detection of the medium, a position regulating mechanisn contrasts a light receiving position of the recording portion, a reflected ray detector distinctively detects reflected rays from defective portions and normal portions of the medium and a reflected ray controller contacts the reflected rays in a manner that the detector can detect optical data by imaging only the reflected ray from a defective portion without the reflected ray from a normal portion.