| 摘要 |
PURPOSE:To prevent an abnormality in a printing operation from being generated even when an input signal is not based on the NTSC system and prevent image quality from being lowered, by automatically setting a printing time for one line according to the vertical synchronization period of a still picture video signal inputted, at the time of hard-copying the still picture video signal. CONSTITUTION:A video signal 1 inputted is changed into a horizontal synchronizing signal and a vertical synchronizing signal by a synchronous separating circuit 2, and is simultaneously demodulated into three primary colors by a demodulating circuit 3. A CPU 7 detects the leading edge of the vertical synchronizing signal, detects a sampling line based on the number of the horizontal synchronizing signals from the moment of the leading edge, and outputs a pulse indicative of a sampling scanning line to one input terminal of a phase comparator 9. An output from a VCO 10 is inputted to the CPU 7 as a driving clock signal for a printing means, and is supplied through a frequency divider in the CPU 7 to another input terminal of the phase comparator. The phase comparator 9 controls the VCO 10 so that the two signals inputted thereto will constantly coincide with each other. The CPU 7 processes data on two lines to form printing data an four lines by use of the driving clock for the printing means, and performs printing. |
