| 摘要 |
PURPOSE:To reduce a residual image and a baking, by scanning an effective scanning section of a target plane with an electron beam at a horizontal blanking period in a television camera using a photo conductive image pickup tube so as to increase the number of scanning in a prescribed time. CONSTITUTION:A sawtooth wave voltage having a vertical period is applied to a terminal 26 and a horizontal pulse where the level is at a high level at an effective scanning period Ha and at a low level at a horizontal blanking period Hr is applied to a terminal 27. Two inputs are added at an adder 29 to form a vertical stepped sawtooth wave voltage in the horizontal blanking period. This waveform is amplified at a positive amplifier 32 and an inverse amplifier 33, and led to a pair of vertical deflection electrodes of an electrostatic deflection image pickup tube from terminals 37, 38. A pulse height V4 at the horizontal blanking period is changed by changing the addition balance of the two signals at the adder 29 and the position on the target plane scanning the electron beam is changed between the horizontal blanking periods. That is, the scanning electron beam is returned to the next horizontal scanning start position during the horizontal blanking period while scanning the target plane finished with the reading scanning already. |
