| 摘要 |
PURPOSE:To monitor the phase relation between the phase of an operated camera and the phase of a reference signal, by superposing a signal, which indicates the signal phase relation among plural TV cameras, to a video signal for an electronic view finder. CONSTITUTION:One of camera video signals supplied from respective cameras is selected by switches 21, 22, and 23 and is outputted, and it is supplied to a mixing circuit 28 and a horizontal synchronizing signal separating circuit 29. The signal supplied to the circuit 29 has the horizontal synchronizing signal separated. This signal is compared with a reference horizontal synchronizing signal, and the lag of phase between them is detected and is supplied to an AND circuit. Meanwhile, a pulse signal for displaying a horizontal line is supplied from a pulse generator 34. Only the AND circuit corresponding to the selected camera controls passage of the pulse for displaying a horizontal line, and respective outputs are returned by an OR circuit 38 and mixing circuits 39 and 28 and are superposed onto the video signal. |
