Patent ID: 7050698

Claim:
A method of synthesizing at least part of a copy protection signal in a video signal wherein the video signal includes video lines having horizontal blanking intervals including horizontal sync, front porch and back porch areas of respective normal levels, and a normal color burst area, comprising: lowering the level of a selected portion or portions of the end of a video line and or of the horizontal blanking interval to a value lower than said respective normal level of the selected portion or portions; inserting a color burst signal of incorrect phase or frequency in a second portion of the horizontal blanking interval; and wherein the second portion is spatially arranged in respect of the selected portion or portions such that an attenuation and or darkening effect caused by a basic copy protection signal causes a recorder or television set to sense the lowered portion or portions to cause the recorder or television set to sample or sense the incorrect color burst signal thereby generating color distortion in the recorder or television set; wherein the incorrect color burst signal is added to at least a portion of the horizontal sync signal and/or to at least a portion of the back porch area so as to enable the sampling or sensing of the incorrect color burst signal; and or wherein the incorrect color burst signal is added to at least a portion of a horizontal sync pulse, and the selected portion which is lowered in level is in at least a portion of the front porch area or in a portion of the active video toward the end of a video line.