| Original document(23 pages) 中文版 |
To provide an objective lens capable of converging a laser beam on an information recording surface while aberration is reduced as far as possible for each of two or more kinds of optical disks having different thicknesses of a transparent substrate, an optical head, an optical system and a design method of the objective lens. The objective lens 5 is used in the optical head for which a distance between a DVD laser 1 and a CD laser 2 is fixed. The objective lens 5 converges the laser beam emitted from the DVD laser 1 to a DVD 6 by a numerical aperture 0.60 and converges the laser beam emitted from the CD laser 2 to a CD 7 by the numerical aperture 0.47. In this case, the wavefront aberration D2 on design relating to the CD is made larger than the wavefront aberration D1 on the design relating to the DVD. |
Application Number
申请号 |
200610128628 |
Application Date
申请日 |
2006.08.29 |
| Title 名称 |
Objective lens, optical head, optical system, and design method for objective lens |
Publication Number
公开号 |
1924631 |
Publication Date
公开日 |
2007.03.07 |
| Approval Pub. Date |
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Granted Pub. Date |
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| International Classification 分类号 |
G02B13/00;G11B7/08;G02B27/00 |
Applicant(s) Name
申请人 |
Hitachi Maxell |
| Address 地址 |
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| Inventor(s) Name 发明人 |
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| Attorney & Agent 代理人 |
zhangjing qiang |
| More information 更 多 信 息 |
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