| 摘要 |
PURPOSE:To ensure the good reproduction not only for the received pictures but for the TV pictures of characters and patterns, by supplying the output of a synchronizing signal separating circuit to a vertical oscillating circuit in the form of a horizontal trigger pulse and securing the synchronism between the rise of the oscillating output pulse of the vertical oscillating circuit and the rise of the horizontal pulse. CONSTITUTION:Either one of the horizontal pulses supplied from a route led from an external video signal source 8 and a horizontal deflecting outut circuit 4 is selected by switching the interlocking switches 11 and 12. When a picture pattern produced from a built-in signal producing circuit 9 is projected, the switches 11 and 12 are set at the (a) side. Thus the horizontal pulse given from the picture 4 is fed to a synchronizing signal separating circuit 1. Furtheroire the horizontal trigger pulse is applied to a vertical oscillating circuit 2 from the circuit 1. Then the vertical oscillating pulse is produced synchronously with the horizontal pulse, and the vertical period becomes longer then the horizontal period by an integer-fold value. The signal is produced from the circuit 9 with the synchronism secured with the horizontal and vertical pulses respectively. Then this signal is applied to a video signal output circuit 10 to project a synchronous picture. |
