| 摘要 |
PURPOSE:To bury a reproduced picture easily when pictures of two different video signals are projected simultaneously, by reproducing video signal information on a magnetic tape with the time axis shortened and by substituting part of the 1st video signal. CONSTITUTION:Monostable multivibrator 26 is triggered by vertical synchronizing signal SV separated from a television signal in reception to generate inverted periodic pulse P1 a half as long as the 1st vertical scanning period IV. This output is led to monostable multivibrator 27, which is triggered at the fall of pulse P1 to generate a pulse of a prescribed inverted period. Similarly, monostable multivibrators 28 and 29 obtain pulses P3 and P4 of the inverted period a half horizontal scanning period 1H. Those pulses P1-P4 are AND-ed and the AND output is supplied to switch circuit 25 which is being supplied with the 1st video signal EE and reproduced video signal SP of VTR, so that a reproduced video signal is projected on the one- quarter area of the screen of the receiver. |
