论文部分内容阅读
一、引言带预刻槽光盘使数据写入时轨迹跟踪伺服简便,使光盘有互换性的优点。在预刻槽光盘中,推挽轨迹跟踪伺服信号是由衍射光束强度分布变化检测的。跟踪伺服和调焦伺服信号能由同一置于远场的光敏管接收。然而,跟踪误差信号和调焦误差信号之间的串扰会使调焦伺服不稳定,同时,由于槽的衍射减弱了光强引起信号幅度的降低。这些问题不仅取决于槽宽和槽深,还取决于预刻槽的槽壁陡度。
I. INTRODUCTION Trajectory tracking servo with pre-grooved disc for data writing has the advantages of interchangeability of discs. In pre-grooved discs, the push-pull trajectory tracking servo signal is detected by a change in the intensity distribution of the diffracted beam. The tracking servo and focus servo signals can be received by the same photosensitive tube placed in the far field. However, crosstalk between the tracking error signal and the focus error signal causes the focus servo to be unstable, and at the same time, the amplitude of the signal decreases due to the light intensity being weakened by the diffraction of the groove. These problems depend not only on the groove width and groove depth but also on the wall steepness of the pre-groove.