公开(公告)号：US20120051204A1

公开(公告)日：2012-03-01

申请号：US13070960

申请日：2011-03-24

申请人： Kunikazu OHNISHI ,  Kazuyoshi YAMAZAKI ,  Mitsuru NAGASAWA

发明人： Kunikazu OHNISHI ,  Kazuyoshi YAMAZAKI ,  Mitsuru NAGASAWA

IPC分类号： G11B7/135

CPC分类号： G11B7/094 ,  G11B7/0912 ,  G11B7/1381

摘要： An optical pickup compatible with two wavelengths such as an optical pickup having a two-wavelength, multi-laser source unit to be compatible with both DVDs and CDs prevents, in a simply structured optical system, error signal quality deterioration caused by relative shifting between laser beams and realizes detection of focus and tracking error signals. The optical system is provided with an optical waveguide device and a photodetector. The optical waveguide device includes a holographic diffraction grating having three regions divided by two approximately parallel division lines which extend respectively passing the optical axes of a laser beam for DVD and a laser beam for CD. The photodetector has plural light receiving surfaces each divided into three regions. This allows reliable focus and tracking error signals to be detected during both DVD reproduction and CD reproduction.

摘要翻译： 与两个波长兼容的光学拾取器，例如具有与DVD和CD兼容的双波长多激光源单元的光学拾取器，在简单结构的光学系统中防止由激光器之间的相对移动引起的误差信号质量劣化 实现对焦和跟踪误差信号的检测。 光学系统设置有光波导装置和光电检测器。 光波导器件包括具有三个区域的三维区域的全息衍射光栅，该区域被分别延伸通过DVD的激光束的光轴和CD的激光束的两个近似平行的分割线分开。 光电检测器具有分成三个区域的多个光接收表面。 这允许在DVD再现和CD再现期间检测可靠的对焦和跟踪误差信号。