| 摘要 |
PURPOSE:To obtain the best resolution on the entire screen, by storing a focus voltage data having the best resolution to a small screen area split arbitrarily and correcting the focus voltage the use of the voltage data in response to actual scanning. CONSTITUTION:A horizontal synchronizing signal HD and a vertical synchronizing signal VD are used as clock pulses and a screen is split into an arbitrary number. The voltage having the best resolution for the split screen are stored in a memory circuit 4 in advance. In case of the use of a camera, a signal read out from the circuit 4 is smoothed through an interpolation circuit 6. This output is amplified to a level required for the correction at an amplifier 7 and superimposed to an electrode G3 via a coupling capacitor 8 as a correction voltage. Thus, an optimum correction can be obtained. Further, the similar effect can be obtained for the level, by changing, e.g., the reference voltage of an A/D converter 5. |
