JPS6412696A - Stereoscopic television signal synthesis circuit - Google Patents

Abstract

PURPOSE:To synthesize and introduce a video signal whose color subcarrier phase is not inverted by specifying the line number per one field. CONSTITUTION:The line number per one field is selected to be (n+1/4) [n is a natural number] lines so as to make the color subcarrier phase consecutive and the carrier phase is made continuous and a vertical synchronizing signal taking an equivalent pulse as 1/4 line period is inserted again at a constant period. That is, the readout data is selected alternately by a selector switch 10 receiving e changeover output as the control input and the result is given to a DA converter circuit 11. The DA converter circuit 11 uses the readout clock generated by a readout clock generating circuit 12 to apply DA conversion to the readout data and the DA conversion output is inputted to a synchronizing re-insertion circuit 13. The synchronization re-insertion circuit 13 inserts the vertical synchronizing signal set at the period of 1/4 line again and leads it out. Thus, a stereoscopic television signal whose vertical synchronizing period is constant and whose horizontal synchronizing period and color subcarrier phase is consecutive is synthesized and introduced.