| 摘要 |
PURPOSE:To obtain a device having good reproducibility of intermediate tone, by phase-adjusting a density curvelike alternating signal which is possessed by a half tone screen, and by binary-coding the same with the video signal subject to logarithmic conversion after controlling a crank level to display it on a CRT. CONSTITUTION:A horizontal synchronizing signal HS separated from a video signal of a TV camera and the output of an oscillator 22 generating a density curvelike alternating signal AS which is possessed by a a half tone screen, are adjusted via a phase adjusting circuit 23. At the same time, the crack level of the output is controlled by a count value from a horizontal synchronizing counter 24 via a control circuit 25 and inputted to a comparison circuit 27. When this input exceeds the level of a logarithmic video signal LI as the reference signal CL, it is outputted from the comparison circuit 27 as a binary signal BS becoming ''1''. It is further superposed with the horizontal synchronizing signal HS and displayed on a CRT in half tone. Thus, the picture having good intermediate tone can be made to hard copy by an electronic photography through using a simple binary circuit. |
