发明名称 Optical pickup device and optical disc apparatus
摘要 In the optical pickup device, while reflection light reflected from the optical multi-layer disc is divided into a plurality of regions so as to produce a plurality of divided optical beams, the divided optical beams are focused onto different positions on a photodetector, and a focus error signal is detected by employing a plurality of the divided optical beams by utilizing the knife edge method, and further, a tracking error signal is detected by employing a plurality of the divided optical beams. Furthermore, the dividing regions of the optical beam and light receiving parts are arranged in such a manner that stray light derived from other layers of the optical disc is not entered to a servo signal-purpose light receiving part of the photodetector when the divided optical beam is focused onto a target layer of the optical disc.
申请公布号 US8040780(B2) 申请公布日期 2011.10.18
申请号 US20090417053 申请日期 2009.04.02
申请人 HITACHI MEDIA ELECTRONICS CO., LTD. 发明人 YAMAZAKI KAZUYOSHI;KITADA YASUO
分类号 G11B7/135 主分类号 G11B7/135
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