Timing extraction device and video display device

Abstract

An asynchronous timing detectordetects and measures a specific pattern (sync pattern) of audio and video reproduced signals having a digital value form an A/D converterand its appearance interval based on an asynchronous clock generated by an asynchronous clock generator, and calculates a cycle ratio of the measured sync pattern appearance interval (the number of clock pulses of the asynchronous clock) to a normal value (the number of clock pulses of a synchronous clock obtained by measuring a sync pattern appearance interval using the synchronous clock). A pseudo-synchronous clock generatorthins the asynchronous clock based on the cycle ratio to generate a pseudo-synchronous clock which is pseudo-synchronous with channel data. Therefore, even when an initial frequency error is large, frequency and phase pull-in is relatively quickly performed until a timing recovery operation becomes stable.