| 摘要 |
PURPOSE: A device for detecting VCR(Video Cassette Recorder) signals is provided not to use a phase error generated in a head switch pulse section, that is a feature for the VCR signal, so as to correctly detect the VCR signals. CONSTITUTION: In a horizontal tracking unit(300), a phase comparator(210) receives synchronizing signals and system clocks, and generates a phase error, that is a phase difference between the synchronizing signals and reference horizontal synchronizing signals every horizontal line. A pixel counter(240) receives and counts the system clocks. And a timing generator(250) receives an output of the pixel counter, to generate horizontal synchronizing signals and vertical synchronizing signals. In a VCR signal detecting unit(310), a head switch pulse section generator(330) reset by the vertical synchronizing signals receives the horizontal synchronizing signals, and sets a predetermined pulse section as a head switch pulse section. And a VCR signal detector(360) receives the phase error during the head switch pulse section, and detects the synchronizing signals as VCR signals if the phase error is over a predetermined reference phase error value. A tracking filter(220) receives the phase error and performs a predetermined operation, to generate an error value obtained by converting the phase error. And an adder(230) adds an offset value for generating a basic frequency to the error value, to generate a frequency value according to the phase error.
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