| 摘要 |
<p>PURPOSE:To automatically detect partial erasure or partial rewrite of a program by continuously recording an identification signal on a section incorporating a recording section of a program signal and detecting the presence of the identification signal. CONSTITUTION:The continuous identification signal 10 is recorded on a video tape 1 beforehand over neatly the whole length of a video tape 1 in addition to a program signal 7. The inflation signal 10 is recorded on the sound track and the control track of the video tape 1, and is made the signal to be hardly recorded by a usual tape recorder beforehand. A partial erasure detection device allows the video tape 1 to travel while reproducing the identification signal 10 in the video tape 1. Then, when the interruption of the identification 10 is detected while traveling, the device decides that the partial erasure exists.</p> |
