ANALOG/DIGITAL CONVERSION DEVICE AND METHOD FOR ANALOG VIDEO SIGNAL

PROBLEM TO BE SOLVED: To provide an analog/digital conversion device and method that receives various video signals, recovers a clock signal depending on the quality of the signals and generates a digital video format signal. SOLUTION: The analog/digital conversion device and method is provided with an analog/digital converter that converts an analog video signal including its synchronous part and its video part into a quantized digital signal, a line clock oscillation section and a frame clock oscillation section that phase-lock to the synchronous component included in the converted quantized digital signal to generate a clock signal for the sampling of the analog/digital converter, and a clock changeover device that selects output signals from the oscillation sections and outputs the selected signal to use the selected signal for a clock signal for a video processing circuit including the analog/digital converter, and also with a signal quality discrimination section that monitors the synchronous component to be compatible with various video signals and executes switching control of the clock changeover device on the basis of contents of the monitoring and a buffer that outputs a predetermined number of sampled data as video data within one horizontal period.