| 摘要 |
PURPOSE:To detect a tracking error signal with a simple constitution by fining out a product signal of a residual error signal generated due to the unattainment of control during tracking control and the varying output of an amplitude detecting output of an RF signal generated due to the influence of an offset and adding the product signal to a difference signal with a reverse phase. CONSTITUTION:Light flux from a light source is irradiated to a recording track consisting of a pit string on a recording medium as a focused spot and the light flux modulated by the pit string is detected by a photodetector provided with photodetecting elements divided to at least two parts of a ring in the direction corresponding to the recording track to detect a difference signal of output signals of the photodetecting elements. On the other hand, a product signal of a residual error signal generated due to the unattainment of control during tracking control and the varying output of an amplitude detecting output of an RF signal generated due to the influence of an offset generated due to the unattainment of the control is found out and the product signal is added to said difference signal with a reverse phase to detect a track error signal.
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