Victor P Bove

US Patent:

46739815, Jun 16, 1987

Filed:

Mar 23, 1984

Appl. No.:

6/592290

Inventors:

Andrew B. Lippman - Salem MA
Victor M. Bove - Cambridge MA
Jerome B. Wiesner - Watertown MA

Assignee:

Massachusetts Institute of Technology - Cambridge MA

International Classification:

H04N 514

US Classification:

358160

Abstract:

A technique for handling video signals so as to permit such signals to be satisfactorily displayed on video display devices, such as TV receivers or monitors, but to prevent such signals from being satisfactorily recorded by video recording devices. In a particular embodiment thereof the video frame time base is altered in a selected manner, as by lengthening or shortening the time bases of successive video frames, or successive groups of video frames. The alterations thereof can be in discrete steps and be performed cyclically so that during each overall cyclical time period the cumulative error is zero.