| 摘要 |
PROBLEM TO BE SOLVED: To provide a signal extracting circuit for a cathode-ray tube which can reduce the influence of unwanted signal components and can extract with high accuracy a desired signal component from the detection signal outputted by an electric index method while it has a simple circuit constitution, and to provide method therefor. SOLUTION: After a differentiating circuit 60 makes an index detection signal Sind and a reference signal Sref into differential waveforms, a differential amplifier part 62 detects an index information signal Sinf by taking a difference. Then, the differential waveform of the index information signal Sinf is restored to a pulse-shaped signal which can be digitally processed by shaping the waveform of the signal. Sine unwanted signal components (components of H pulses, etc.) are attenuated in the stage preceding the signal extraction by the differentiating circuit 60, the influence of the unwanted signal components can be reduced and adjustment circuits for adjusting the amplitude/phase of the index detection signal Sind and the reference signal Sref are made unnecessary. Moreover, the dynamic range of a signal extracting part 61 can be made smaller. COPYRIGHT: (C)2004,JPO
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