Invention Grant
- Patent Title: Objective lens and optical pickup apparatus using the same
- Patent Title (中): 物镜和使用其的光学拾取装置
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Application No.: US13308055Application Date: 2011-11-30
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Publication No.: US08345530B2Publication Date: 2013-01-01
- Inventor: Mitsuru Ito
- Applicant: Mitsuru Ito
- Applicant Address: JP Moriguchi-shi JP Tokyo
- Assignee: SANYO Electric Co., Ltd.,SANYO Optec Design Co., Ltd.
- Current Assignee: SANYO Electric Co., Ltd.,SANYO Optec Design Co., Ltd.
- Current Assignee Address: JP Moriguchi-shi JP Tokyo
- Agency: Morrison & Foerster LLP
- Priority: JP2010-265932 20101130
- Main IPC: G11B7/00
- IPC: G11B7/00

Abstract:
Disclosed is an objective lens that favorably focuses multiple laser beams having different wavelengths on information recording layers of optical discs, and an optical pickup apparatus including the lens. The objective lens of the invention is provided with a first region for focusing laser beams of the BD, DVD and CD standards. The first region is provided with an annular zone step having a height calculated on the basis of a wavelength of the laser beam of the BD standard, and thus causes chromatic aberration of the laser beam of the DVD standard. This chromatic aberration corrects spherical aberration occurring due to a difference in thickness between coating layers of optical discs. In the invention, the curve surface shape of the first region is adjusted so that the BD and DVD standards can share the aberration for reducing the aberration of the laser beam of the DVD standard.
Public/Granted literature
- US20120134255A1 OBJECTIVE LENS AND OPTICAL PICKUP APPARATUS USING THE SAME Public/Granted day:2012-05-31
Information query
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