Invention Grant
- Patent Title: Optical pickup and optical information processing device
- Patent Title (中): 光学拾取和光学信息处理设备
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Application No.: US12531193Application Date: 2008-04-15
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Publication No.: US08259555B2Publication Date: 2012-09-04
- Inventor: Yukiko Hamano , Hideaki Hirai , Toshimichi Nasukawa , Kazuhiro Umeki
- Applicant: Yukiko Hamano , Hideaki Hirai , Toshimichi Nasukawa , Kazuhiro Umeki
- Applicant Address: JP Tokyo
- Assignee: Ricoh Company, Ltd.
- Current Assignee: Ricoh Company, Ltd.
- Current Assignee Address: JP Tokyo
- Agency: Dickstein Shapiro LLP
- Priority: JP2007-116376 20070426; JP2007-286017 20071102
- International Application: PCT/JP2008/057783 WO 20080415
- International Announcement: WO2008/136315 WO 20081113
- Main IPC: G11B7/135
- IPC: G11B7/135 ; G11B7/00

Abstract:
A disclosed optical pickup includes an aberration correction unit with a phase shifter surface. On the phase shifter surface, rectangular or staircase-like steps are formed in a concentric manner around an optical axial center, in certain regions where a light beam passes through. The steps have different heights in the optical axial direction. A light beam having a wavelength of 405 nm is directly transmitted through the steps so that a phase difference is applied for correcting spherical aberration that occurs on a first optical recording medium. A light beam that passes through an annular region without any steps is focused on a second optical recording medium. A light beam that passes through an outside region is focused by an object lens on the second optical recording medium, and is not focused on the first optical recording medium.
Public/Granted literature
- US20100135130A1 OPTICAL PICKUP AND OPTICAL INFORMATION PROCESSING DEVICE Public/Granted day:2010-06-03
Information query
IPC分类: