Oblon, Fisher, Spivak, McClelland & Maier
Electronic editing method and apparatus for a video tape recorder
 A method and apparatus for a video tape recorder to record a new video signal successively to an old video signal prerecorded on a magnetic tape for editing a magnetic recording in such a manner that, when played back, no picture disturbance is produced at the edited transition of the tape. An end part of the tape bearing recorded information is rewound upon completion of recording thereof. Prior to the recording of a new video signal, the rewound part of the tape is played back to pick up control signals therefrom and the phase of the latter is compared with that of vertical synchronizing signals contained in the new video signal. Upon coincidence of these phases with each other, the operational mode of the video tape recorder is switched from playback to recording and actual recording of the new video signal is commenced. When the magnetic tape thus edited is played back, no picture disturbance results at the edited transition of the tape and desirable pictures can be obtained. 
Akai Electric Company Limited
G G G Y
G11B G11B G11B Y10S
inventional inventional inventional additional
Motonori Tatsumi
Fukatsu Nakano