| 摘要 |
<p>The conventional vertical drive sawtooth is modified, during the camera setup mode, to halve the slope thereof for a given field time interval, or intervals, and to double the slope for the remaining field time interval. It follows that the speed of vertical scan is halved and doubled respectively, in the corresponding field time intervals. In the interval of double scan speed, blooming occurs and twice the usual beam current is required to successfully discharge the picture. Thus when the beam set circuit is in operation as during the setup mode, the beam current is increased until the blooming existing in the double scan speed interval just subsides. The beam current has then been set at 200% of typical beam level.</p> |
