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. 18, 1989
Filed:
Nov. 25, 1987
Klaus Ostertag, Munich, DE;
Karl Pietzsch, Geretsried, DE;
Abstract
In a scanner for the optical checking of objects such as CD-discs there is provided a coherent light source; a light deflecting device which allows a light beam emitted from the light source to sweep over the object in a substantially linear scanning movement, with the optical axis of the light beam subtending a small angle with a normal to the object surface transverse to the scanning direction; and a detector for detecting light which is reflected back from the object. In the present arrangement the optical axis of the light beam also subtends a small angle with the normal to the object surface in the scanning direction. This makes it possible to avoid disturbing modulation of the detector signal due to interference effects.