发明名称 |
Optical pickup device, optical information recording and reproducing apparatus, expander lens, coupling lens and chromatic aberration correcting optical element |
摘要 |
An optical pickup apparatus includes first and light sources; an objective lens; a spherical aberration correcting optical unit; and a chromatic aberration correcting optical element which includes a diffractive surface on at least one of optical surfaces of the chromatic aberration correcting optical element such that a diffractive structure which is constructed by a plurality of ring-shaped zones separated by fine steps is formed on the diffractive surface, wherein the depth of steps along an optical axis is designed so that n2 which is a diffraction order of a diffracted ray having a largest diffraction efficiency among diffracted rays caused when the second light flux enters into the diffractive structure, is lower order than n1 which is a diffraction order of a diffracted ray having a largest diffraction efficiency among diffracted light rays caused when the second light flux enters into the diffractive structure.
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申请公布号 |
US2004213131(A1) |
申请公布日期 |
2004.10.28 |
申请号 |
US20040826524 |
申请日期 |
2004.04.19 |
申请人 |
KONICA MINOLTA OPTO, INC. |
发明人 |
KIMURA TOHRU;MORI NOBUYOSHI |
分类号 |
G11B7/00;G11B7/125;G11B7/135;(IPC1-7):G11B7/135 |
主分类号 |
G11B7/00 |
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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