Invention Grant
- Patent Title: Objective lens for optical pickup
- Patent Title (中): 物镜用于光学拾音
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Application No.: US10430212Application Date: 2003-05-07
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Publication No.: US07224662B2Publication Date: 2007-05-29
- Inventor: Shuichi Takeuchi , Koichi Maruyama , Daisuke Koreeda
- Applicant: Shuichi Takeuchi , Koichi Maruyama , Daisuke Koreeda
- Applicant Address: JP Tokyo
- Assignee: PENTAX Corporation
- Current Assignee: PENTAX Corporation
- Current Assignee Address: JP Tokyo
- Agency: Greenblum & Bernstein, P.L.C.
- Priority: JP2002-133140 20020508
- Main IPC: G11B7/135
- IPC: G11B7/135

Abstract:
An objective lens for an optical pickup is configured such that, when a light beam having a wavelength corresponding to the optical disc requiring the higher NA is converged on the optical disc requiring the higher NA at the higher NA, the phase of light flux passed through the peripheral area is substantially the same as that passed through the central area. When a light beam having a wavelength corresponding to the optical disc requiring the lower NA is converged on the optical disc requiring the lower NA at the lower NA, the phase of light flux passed through a first annular region included in the peripheral area is different from that passed through the central area, and the phase of light flux passed through a second annular region, which is outside the first region, is substantially the same as that passed through the central area.
Public/Granted literature
- US20030210639A1 Objective lens for optical pickup Public/Granted day:2003-11-13
Information query
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