发明授权
- 专利标题: Compound objective lens, optical head device, optical information device, and information processing device
- 专利标题(中): 复合物镜,光头装置,光信息装置和信息处理装置
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申请号: US13257380申请日: 2011-01-07
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公开(公告)号: US08305864B2公开(公告)日: 2012-11-06
- 发明人: Yoshiaki Komma , Katsuhiko Hayashi , Fumitomo Yamasaki , Michihiro Yamagata
- 申请人: Yoshiaki Komma , Katsuhiko Hayashi , Fumitomo Yamasaki , Michihiro Yamagata
- 申请人地址: JP Osaka
- 专利权人: Panasonic Corporation
- 当前专利权人: Panasonic Corporation
- 当前专利权人地址: JP Osaka
- 代理机构: Wenderoth, Lind & Ponack, L.L.P.
- 优先权: JP2010-014940 20100127; JP2010-070706 20100325
- 国际申请: PCT/JP2011/000054 WO 20110107
- 国际公布: WO2011/093007 WO 20110804
- 主分类号: G11B7/00
- IPC分类号: G11B7/00
摘要:
A compound objective lens, an optical head device, an optical information device, and an information processing device that can inhibit the occurrence of aberration even when a light beam source wavelength shifts from the designed value. A diffraction structure having a sawtooth or stepwise cross section is formed in the region (R10) and region (R20). The height of the sawtooth or stepwise cross section formed in the region (R10) provides a light beam, which has a predetermined wavelength, with a difference in optical path length of N times the predetermined wavelength, as compared with a case of propagation in air. The height of the sawtooth or stepwise cross section formed in the region (R20) provides the light beam, which has the predetermined wavelength, with a difference in optical path length of J times the predetermined wavelength, as compared with a case of propagation in air. At least one of the difference in height between both ends of a boundary band (RB) provided between the region (R10) and the region (R20), and the width of the boundary band (RB) provides the light beam, which has the predetermined wavelength, with a difference in optical path length of (N+J)/2 times (N and J are mutually different natural numbers) the predetermined wavelength, as compared with a case of transmission in air.