JPS6439173A - Magnetic video recording/reproducing device - Google Patents

Abstract

PURPOSE:To realize the simultaneous reproduction of both the input signal and the reproduction signal by providing a means which takes out the reproduction signal of an input video signal, a means which produces a synthetic video signal, and a means which holds the luminance signal at a prescribed level at a switching point. CONSTITUTION:A vertical synchronizing signal 52 is separated from an input video signal 51 inputted to a VTR by a synchronizing separator 11. A motor rotation control circuit 12 control the rotation of a motor 13 based on the signal 52 and drives a magnetic tape 15. A reproduced video signal processing circuit 17 extracts signals out of the tape 15 and processes them to outputs a reproduced video signal 53. A video signal switching signal producing circuit 16 produces a signal 57 via a monostable multivibrator having about a 50% duty ratio which is triggered by the signal 52. The signal 57 and a horizontal synchronizing signal 58 received from the circuit 11 are inputted to an FF circuit for production of a switch signal 54 in a horizontal fly-back period. A luminance level holding circuit 19 outputs a signal 55 which holds it level at a fixed value for a 3H period in synchronism with the fall of the signal 54. A synthetic signal 57 of the signal 51 received from a switch 18 and the signal 53 is synthesized again with a signal 55 for output of a signal 56.