| 摘要 |
PURPOSE: To minimize the capacity of vertical deflection circuit for storing video signals by starting vertical deflection together with a first horizontal pulse following the edge of a vertical pulse and terminating the deflection at a standby position which precedes the next vertical pulse. CONSTITUTION: A vertical synchronization pulse Va separated from received signals BAS is supplied to a pulse shaper 2, and the shaper 2 generates a vertical pulse V having a duration which is equal to or longer than one scanning line. The vertical pulse V and a horizontal pulse H* derived from a scanning line deflection current IH are supplied to the input side of a synchronous stage 3. Vertical deflection is started, together with the first horizontal pulse H* following the edge of the vertical pulse V and terminated at the standby position which precedes the next vertical pulse. When a vertical deflection circuit is constituted in such a way, the video signal storing capacity of the circuit can be minimized, and the circuit becomes suitable for an asynchronous self-running and oscillating horizontal deflection circuit. |
