- 专利标题: Objective lens and optical pickup apparatus, information recording/reproducing apparatus
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申请号: US10462770申请日: 2003-06-17
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公开(公告)号: US07054074B2公开(公告)日: 2006-05-30
- 发明人: Takeshi Mizuno , Takatoshi Yamada
- 申请人: Takeshi Mizuno , Takatoshi Yamada
- 申请人地址: JP
- 专利权人: Sony Corporation
- 当前专利权人: Sony Corporation
- 当前专利权人地址: JP
- 代理机构: Rader, Fishman & Grauer PLLC
- 代理商 Ronald P. Kananen
- 优先权: JPP2002-175459 20020617
- 主分类号: G02B13/18
- IPC分类号: G02B13/18 ; G11B7/00
摘要:
An objective lens is configured of a first crown-glass lens and a second flint-glass lens, whereby it can exhibit substantially identical optical properties at a plurality of recording/reproducing light source wavelengths, particularly, in both 650 nm and 405 nm wavelength bands. Also, by maximizing the difference in glass transition point between the first and second lenses, one of the first and second lenses having a higher glass transition point is molded first, to allow that first molded lens to serve as a mold tool for molding the other lens. This dispenses with the steps of aligning and adhesive bonding the two lenses, whereby this objective lens can be used at a plurality of wavelengths as a single objective lens, and thus an information recording/reproducing apparatus can be of a simple configuration.