发明名称 |
Objective lens design method, lens, and optical system, optical head, and optical disc apparatus using the same |
摘要 |
When the DVD provided with the DVD substrate 2 having thickness t2of 0.6 mm is installed in the optical disc apparatus, the light beam 4 having wavelength lambda1=655 nm is used as luminous flux of numerical aperture NA=0.63 to be condensed on the information surface 2a on the DVD substrate 2. When the CD provided with the CD substrate 3 having thickness t2 of 1.2 mm is installed in the optical disc apparatus, the light beam 5 having wavelength lambda2=790 nm is effectively used as luminous flux of approximate numerical aperture NA=0.45 to be condensed on the information surface 3a on the DVD substrate 3. The wavefront aberration caused by a thickness difference between the DVD substrate 2 and CD substrate 3 is canceled out by the chromatic aberration caused by a wavelength difference between the light beams 4 and 5. Therefore, in spite of the difference in the transparent substrates, the light beams are suitably condensed respectively on the information surface 2a and 3a. |
申请公布号 |
US6678096(B2) |
申请公布日期 |
2004.01.13 |
申请号 |
US20020330289 |
申请日期 |
2002.12.30 |
申请人 |
HITACHI MAXELL, LTD. |
发明人 |
SUGI YASUYUKI;MARUYAMA TAKESUKE |
分类号 |
G02B13/00;G02B3/00;G02B13/18;G11B7/00;G11B7/135;(IPC1-7):G02B13/18 |
主分类号 |
G02B13/00 |
代理机构 |
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代理人 |
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主权项 |
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地址 |
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