| 摘要 |
<p>A digital filter unit (15), such as may be used in a time-axis error correction loop of a video disk player or the like, having a simplified construction and reduced servo lag time. The inventive filter unit includes an analog-to-digital converter (21) for converting a signal representing a phase difference between a reference horizontal synchronizing signal and an a horizontal synchronizing signal extracted from the reproduced video signal, a digital filter (22) unit to which the phase-difference signal is applied, a digital-to-analog converter (23) for converting the digital output from the digital filter back into an analog signal, and an analog low-pass filter (24) which smooths the analog output from the digital-to-analog converter (23). In accordance with the inventive concept, in the output signal from the digital-to-analog converter, the frequency response characteristic in a relatively high frequency band is determined by the digital filter, while the characteristic in a relatively low frequency band is determined by the analog low-pass filter.</p> |
