| 摘要 |
PURPOSE:To apparantly improve the sharpness of a picture to be displayed, by means of a dotlike sampling, by sampling a video signal to be displayed, by pulses are arranged in order at every horizontal scanning in phase, or those which are shifted at every scanning by 1/2 period. CONSTITUTION:An input video signal 1 is amplified by a band-pass characteristic matching the band of the signal 1 which has been input by the first video amplifier 2, is input to the sampling pulse generating circuit 3, and generates a sampling pulse 31 whose frequency is higher than the maximum frequency of the signal 1 and phase has been locked to horizontal scanning. Also, an output signal from the amplifier 1 is privided to the sampler 4, and is sampled by the pulse 31 from the circuit 3. And, the video signal which has been sampled by the sampler 4 is amplified by the second video amplifier 5, is provided to the cathode of the CRT10 or the grid, and the signal which has been sampled in the form of dots is displayed on the CRT, so that the sharpness of a picture to be displayed is improved. |
