Video signal processing device, information processing system, and video signal processing method

• Main Author: HIRASHIMA; SATOSHI
• Format: Patent
• Language: English
• Published: 10.08.1999
• Edition: 6
• Subjects: ADVERTISING; ARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICESUSING STATIC MEANS TO PRESENT VARIABLE INFORMATION; CRYPTOGRAPHY; DISPLAY; EDUCATION; ELECTRIC COMMUNICATION TECHNIQUE; ELECTRICITY; PHYSICS; PICTORIAL COMMUNICATION, e.g. TELEVISION; SEALS; TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHICCOMMUNICATION

An A/D converter samples an analog video signal, having a frequency corresponding to various types of image supply apparatus, and converts the signal into a digital signal. A sampling clock signal supply circuit supplies a sampling clock signal to the A/D converter, and comprises an edge detection circuit for adjusting the phase of the sampling clock signal. The edge detection circuit subjects the video signal and a delayed video signal to subtraction processing to generate edge pulses. A processor selects a sampling clock signal of a desired phase based on edge information determined by these edge pulses. The present device can also adjust a threshold voltage that is input to the comparator, and the phase of the sampling clock signal based on a digital signal, and supply a dedicated video signal for phase adjustment from a personal computer.