Patent ID: 6404974
Filing Date: 2002-06-11
Classification: G11B,H04N

Abstract:
A method for treating a video signal to mitigate an ability of a video signal recording system having an automatic gain control for adjusting the video signal level, to copy an acceptable video signal for displaying therefrom, including:inserting a pulse signal into the video signal during a horizontal blanking interval of a line of video signal to provide a treated video signal, said pulse signal having a magnitude sufficient to cause the treated video signal to overcompensate the automatic gain control of the video signal recording system; and biasing a portion of the video signal during said horizontal blanking interval to offset a direct current (dc) voltage shift caused in the video signal by said inserting; wherein said pulse signal is inserted into a sufficient number of lines of the video signal to cause visual impairment of a reproduced picture information portion contained in a copy made of the treated video signal by said video signal recording system.