Drop-out detecting system for video recording magnetic tape

DETAILED DESCRIPTION It is an object, therefore, of the present invention to overcome the disadvantages and limitations of the prior drop-out detecting systems, by providing a new and improved drop-out detecting system for video recording magnetic tapes.
It is also an object of the present invention to provide a drop-out detecting system in which a visual detection coincides completely with an electrical detection by utilizing an ordinary video tape recorder.
The above and other objects are attained by a drop-out detecting system for video recording magnetic tapes comprising of a tape running means having at least a helical scan head for reading the signal recorded magnetically on an oblique video channel of the tape to be tested, and a voice channel head positioned apart from said helical scan head along the path of the tape; a drop-out detector connected to the output of said helical scan head of the tape running means; a drop-out position detector consisting of a counter, which is initiated by the head element switching signal of said helical scan head from said tape running means, and said counter being decremented or incremented by the predetermined pulse train for providing the position (k) of the drop-out on an oblique video channel; a delay calculator for providing the marking signal after the time C.
sub.
1 k+C.
sub.
2, where C.
sub.
1 and C.
sub.
2 are constants, elapses from the detection of the drop-out by said drop-out detector; and means for providing a recording signal to said voice channel head of said tape running means upon receipt of said marking signal from the delay calculator.