| 摘要 |
PURPOSE:To eliminate a need of transmission of synchronous information of another medium and to improve the scrambling effect by obtaining each synchronizing signal of a video signal based on conversion of the synchronizing signal. CONSTITUTION:A waveform H2 in a horizontal scanning line period includes at least one pulse waveform set in a period Ta and a reference voltage period Tr, and an amplitude B of the pulse waveform is an about middle value of an amplitude of upper and lower peak voltages of the video signal. With respect to a waveform V2 in the vertical fly-back time, a synchronizing code sequence having an amplitude C(>B) to indicate a vertical synchronizing signal is arranged in plural scanning line periods Td except the horizontal fly-back time of the normal vertical fly-back time, and a reference voltage period Te in which the voltage is equal to that in the period Tr of the waveform H2 is arranged just after the synchronizing code sequence. Thus, transmission of synchronizing information of another medium is unnecessary to improve the use efficiency of frequency, and the safety of a system is secured, and the scrambling effect is improved. |
