| 摘要 |
PURPOSE:To prevent a circuit scale from becoming small and generating heat without increasing vertical deflection current and to make over-scanning to be small in the same way as that at a normal mode and to eliminate the need of special consideration for the neck of an image receiving tube at the time of realizing a zoom mode when the video signal of a regular aspect ratio is displayed on the image-receiving tube of a wide aspect ratio. CONSTITUTION:A sawtooth wave generation circuit 1A generating a vertical sawtooth wave signal whose start of a flyback time is made earlier than the phase of the video signal at regular time by a prescribed period when picture amplitude in a vertical direction is enlarged and displayed, and vertical output means (2-18 and 23) which amplifying the vertical sawtooth wave signal, supplying vertical deflection current to a vertical deflection coil 8, and supplying vertical deflection current whose vertical amplitude is the same as that of regular time when vertical amplitude is enlarged and whose flyback time is made longer than that at regular time by the prescribed period to the vertical deflection coil 8 are provided. |
