INFORMATION RECORDING MEDIUM AND INFORMATION RECORDING AND REPRODUCING DEVICE USING IT

摘要

PROBLEM TO BE SOLVED: To provide a recording and reproducing device adopting a recording coding system including a DC component that facilitates setting of a threshold value for data reproduction (binarization). SOLUTION: A VFO(variable frequency oscillator) pattern where a ratio of periods for mark and space parts differs from each other is recorded on a VFO area used for phase locking of a clock. In the case of reproducing the VFO area, a phase of a PLL(phase lock loon) is locked and an average of reproduction signals for this period is obtained. When the VFO period is finished, the average is stored. The value is used for a threshold value for binarization of the reproduction signals.