| 摘要 |
PROBLEM TO BE SOLVED: To achieve high precision position demodulation while reducing the table size in a position demodulating device to recover the correct positioning by using phase servo patterns. SOLUTION: This position demodulating device has a servo demodulator circuit (30) to demodulate the first and second vector information from the reproduced phase servo pattern signals of the recording medium (10), a processing unit (40) to calculate the tan value of the difference angle from the first and second vector information and to calculate the deviations at the track center in an approximate expression, and a difference table (64). Since the approximate expression and the difference are used, the table size can be significantly reduced and high precision position demodulation is available even with a low-speed processor. Thus, high precision position demodulation can be achieved in an inexpensive device. COPYRIGHT: (C)2009,JPO&INPIT
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