公开(公告)号：US20080137495A1

公开(公告)日：2008-06-12

申请号：US11885803

申请日：2005-12-26

申请人： Kenya Nakai

发明人： Kenya Nakai

IPC分类号： G11B7/00

CPC分类号： G11B7/0941 ,  G11B7/0909 ,  G11B7/094 ,  G11B7/0943 ,  G11B7/131

摘要： [Problem to be Solved] It has been a problem that, with focusing servo control based on a focus error signal according to a conventional astigmatism method, due to a positional deviation of a received light beam on the light-receiving plane of a photodetector or an offset caused by asymmetry in the intensity distribution of reflected light, an error occurs in the focus error signal, whereby the focusing servo cannot correctly be performed.[Solution] A signal, which is derived from the relationship between the lens shift amount of an objective lens (7) and the amount of the positional-deviation, of a received light beam with respect to a light-receiving plane, which occurs in the tangential direction on a photodetector (12), is corrected by an offset caused by asymmetry in the intensity distribution of reflected light; a multiplication value is obtained by multiplying the corrected signal by a predetermined constant; based on a focus error signal obtained by subtracting the calculated value from the calculation expression according to the conventional astigmatism method, the focusing servo control is performed.

摘要翻译： [待解决的问题]由于接收光束在光电检测器的受光面上的位置偏差或者根据传统散光方法的基于聚焦误差信号的聚焦伺服控制，存在问题，或者 由于反射光的强度分布不对称引起的偏移，在聚焦误差信号中出现误差，从而不能正确地执行聚焦伺服。 [解决方案]根据物镜（7）的透镜偏移量与接收光束相对于光接收面的位置偏移量之间的关系导出的信号，其发生在 通过由反射光的强度分布的不对称引起的偏移来校正光电检测器（12）上的切线方向; 通过将校正信号乘以预定常数获得乘法值; 基于通过根据传统散光方法从计算表达式减去计算值而获得的聚焦误差信号，执行聚焦伺服控制。

公开(公告)号：US06912192B2

公开(公告)日：2005-06-28

申请号：US10238581

申请日：2002-09-11

申请人： Masahisa Shinoda ,  Kenya Nakai

发明人： Masahisa Shinoda ,  Kenya Nakai

IPC分类号： G11B7/08 ,  G11B7/125 ,  G11B7/22 ,  H01S5/022 ,  H01S5/40 ,  G11B7/00

CPC分类号： G11B7/1275 ,  G11B7/082 ,  G11B7/22 ,  H01S5/02212 ,  H01S5/02268 ,  H01S5/02296 ,  H01S5/4031 ,  H01S5/4087

摘要： A semiconductor laser unit includes a plurality of semiconductor laser elements arranged parallel with one another in a laser beam-emitting direction, and a base for positioning and fixing the plurality of semiconductor laser elements. The plurality of semiconductor laser elements are arranged such that a laser beam emitted from the semiconductor laser element greatest in astigmatism, of the plurality of semiconductor laser elements, is coincident in its axis with a reference axis of the base. In the case that the semiconductor laser unit is arranged on an optical head device, the focusing characteristic on the plurality of laser beams can be improved.