JPS645175A - Video printer - Google Patents

Abstract

PURPOSE:To eliminate the need for a high speed operation control circuit element for a noninterlacing signal by inputting both the interlacing signal and a noninterlacing signal with clock signals of equal frequency without varying the frequency of a clock signal supplied to a memory control part, an address control part, etc. CONSTITUTION:A processing circuit for the interlacing signal which samples a video signal and holds one-line data in a line memory 8 has a means which inverts the polarity of the clock of a clock generation part 1 by 180 deg. every print-line intervals so as to reduce time base pitch of printing to nearly a half without switching the frequency of a sampling clock from a horizontal address control part 2, a means which reduces the clock frequency of a print line counter to a half, and write/read address control means 3 and 4 for a line memory. Then a means which performs the interlacing/noninterlacing switching of them is provided. Consequently, a video printer for both interlacing and noninterlacing signals which is different in horizontal synchronizing frequency by nearly one and a half times is obtained.