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:
Sep. 27, 2005
Filed:
Jan. 25, 2000
John O. Ryan, Woodside, CA (US);
James R. Holzgrafe, Morgan Hill, CA (US);
Mark A. Hollar, Palo Alto, CA (US);
John O. Ryan, Woodside, CA (US);
James R. Holzgrafe, Morgan Hill, CA (US);
Mark A. Hollar, Palo Alto, CA (US);
Macrovision Corporation, Santa Clara, CA (US);
Abstract
A method and apparatus for modifying a video signal to allow it to carry encoded data which is detectable at a suitably compliant receiver but is not recorded by a conventional video recorder. One application is to carry a descrambling key to prevent useful recording (but not viewing) of a scrambled television signal since the key will not be recorded. This encoded 'hidden' data is not recorded by the conventional video recorders because, for instance, it is located in the vertical or horizontal blanking intervals of the video signal, or is carried by a high frequency carrier signal, or is expressed by phase modulation of the video signal's synchronization pulses.