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:
Feb. 18, 1986
Filed:
Aug. 24, 1981
Applicant:
Inventor:
Steven R Hofstein, North Brunswick, NJ (US);
Assignee:
Other;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
H04N / ; H04N / ;
U.S. Cl.
CPC ...
360 371 ; 358120 ;
Abstract
An apparatus for modifying a video signal to protect the unauthorized recording and reproduction thereof is disclosed. In accordance with the invention, the video signal is modified in such a manner that insufficient vertical synchronization information is contained in some, but not all, of the vertical blanking intervals. Particularly, insufficient vertical synchronization information is contained in a sequence of vertical blanking intervals which will cause the rotational velocity of the tape head of the VTR to constantly vary.
Hofstein, Steven. (1986). Method of and apparatus for modifying a video signal to prevent the (U.S. Patent No. 4571642). U.S. Patent and Trademark Office. https://idiyas.com/patent/badge/4571642
Data source: USPTO (United States Patent and Trademark Office) public patent records. Weekly synchronization. How IDiyas builds this profile