- 专利标题: OPTICAL PICKUP APPARATUS
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申请号: US13416858申请日: 2012-03-09
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公开(公告)号: US20120170441A1公开(公告)日: 2012-07-05
- 发明人: Tohru Hotta , Ryoichi Kawasaki , Kenji Kan , Hiroyuki Shindo
- 申请人: Tohru Hotta , Ryoichi Kawasaki , Kenji Kan , Hiroyuki Shindo
- 申请人地址: JP Tokyo JP Osaka
- 专利权人: SANYO OPTEC DESIGN CO., LTD.,SANYO ELECTRIC CO., LTD.
- 当前专利权人: SANYO OPTEC DESIGN CO., LTD.,SANYO ELECTRIC CO., LTD.
- 当前专利权人地址: JP Tokyo JP Osaka
- 优先权: JP2007-52769 20070302
- 主分类号: G11B7/1376
- IPC分类号: G11B7/1376 ; G11B7/1374
摘要:
An optical pickup apparatus includes an objective lens having a numeric aperture and an incident face. An antireflection coating is formed on the incident face. A collimating lens converts laser light from a laser diode into parallel light, and causes the parallel light to be made incident on the incident face through the antireflection coating. The thickness of the antireflection coating causes a transmittance of laser light that enters the objective lens to be: set at a first predetermined transmittance value, when the numeric aperture is between zero and a first predetermined numeric aperture value; set to correlate linearly with the numeric aperture when the numeric aperture is between the first predetermined numeric aperture value and a second predetermined numeric aperture value; and set at a second predetermined transmittance value, when the numeric aperture is between the second predetermined numeric aperture value and a third predetermined numeric aperture value.
公开/授权文献
- US08363533B2 Optical pickup apparatus 公开/授权日:2013-01-29
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