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:
Apr. 13, 1982
Filed:
Oct. 15, 1980
Howard M Langley, Mooresville, IN (US);
Joseph W Stephens, Plainfield, IN (US);
RCA Corporation, New York, NY (US);
Abstract
In an apparatus for detecting defects on capacitive video disc records, a pickup stylus spanning a plurality of information tracks is effectively swept over the recorded disc area by rotation of the disc. The stylus, upon encountering a convex surface defect, is lofted from the disc surface with a consequent reduction in stylus-disc capacitance. The change in capacitance is indicative of the stylus ejection distance and thereby releated to the size of the defect. Transducers monitor the radial position of the stylus and the angular position of the disc. Each time a disc defect generates a defect indicative capacitance change, the coordinates of the defect are recorded as well as the magnitude of the capacitance change.