| 摘要 |
PROBLEM TO BE SOLVED: To reliably achieve HMW demodulation with a simple configuration. SOLUTION: The reproduced wobble signals are processed in advance through a BPF of a center frequency 2fwob to enhance the secondary harmonics. The secondary harmonic signals are multiplied by the wobble signal after passing the BPF. Then, peak envelope signals and bottom envelope signals are obtained from the signals after the multiplication. Then, the peak envelope signals are discriminated by using the first predetermined threshold, and this discrimination result becomes the detected signal of the HMW [1]. In the same manner, the bottom envelope signals are discriminated by using the second predetermined threshold, and this discrimination result becomes the detected signal of the HMW [0]. COPYRIGHT: (C)2007,JPO&INPIT
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