GRAPHIC ART DEVICE FOR TELEVISION PICTURE

摘要

PURPOSE:To improve the quality of a graphic art image and to recover the deterioration of the picture in the form of moire or mosic and S/N ratio by passing a LPF a signal read out of memory to be input to a scanner through an LPF. CONSTITUTION:A slow signal to be input to a scanner is passed through a variable low pass filter 23. Its cutoff frequency is controlled interlocking with a magnification setting circuit 22. Of which reason is that the clock frequency of a read pulse train is different depending upon the intensity of the light to which the film is exposed. The variable LPF23 is an active filter using an operational amplifier, which is set up with C and R without using L, so that the cutoff frequency of said LPF23 is determined at an optimum value.