| 摘要 |
PURPOSE:To improve picture quality and to attain a freely special screen processing by scanning an information source to be image picked up such as a photo film and an original with a light spot and controlling at least one of the luminance and spot diameter of the light spot depending on a position. CONSTITUTION:Light spot control information L is inputted to a D/A conversion section 17, to which a modulation signal Mm is inputted, the light spot information L is converted into an analog signal having an amplitude in response to said modulation signal Mm and the signal is fed to a light spot control drive section 18. The light spot control drive sction 18 amplifies the analog signal and outputs it to a cathode ray tube as a light spot control signal E. That is, a light spot modulation circuit 14 outputs the light spot control signal E in response to a position signal C. In controlling the luminance of a light spot P, the light spot control signal E controls the acceleration voltage of an electron gun of the cathode ray tube 1 and in controlling the spot diameter of the light spot P, the light spot control signal E controls the voltage of the electrode converging an electron beam or the current of a converging coil. |
