公开(公告)号：US20120155241A1

公开(公告)日：2012-06-21

申请号：US13407405

申请日：2012-02-28

Applicant: Kohei OTA ,  Nobuyoshi MORI ,  Junji HASHIMURA ,  Tohru KIMURA ,  Kiyono IKENAKA ,  Katsuya SAKAMOTO ,  Eiji NOMURA

Inventor： Kohei OTA ,  Nobuyoshi MORI ,  Junji HASHIMURA ,  Tohru KIMURA ,  Kiyono IKENAKA ,  Katsuya SAKAMOTO ,  Eiji NOMURA

IPC: G11B7/1353

CPC classification number: G11B7/1367 ,  G11B7/1275 ,  G11B7/1353 ,  G11B7/1374 ,  G11B7/13922 ,  G11B2007/0006

Abstract: An optical pickup apparatus includes: a first light source for emitting a first light flux; a second light source for emitting a second light flux; a third light source for emitting a third light flux; and an objective optical unit having a first optical path difference providing structure and a second optical path difference providing structure. Magnifications of the objective optical unit for the first-third light fluxes have almost same value. The first optical path difference providing structure provides a predefined optical path difference and changes a spherical aberration to be one of under-correction and over-correction for all of the first light flux, the second light flux, and the third light flux. The second optical path difference providing structure provides a predefined optical path difference and changes a spherical aberration to be the other of under-correction and over-correction of the spherical aberration only for the second light flux.

Abstract translation: 一种光学拾取装置包括：用于发射第一光通量的第一光源; 用于发射第二光通量的第二光源; 用于发射第三光通量的第三光源; 以及具有第一光程差提供结构和第二光程差提供结构的物镜光学单元。 用于第一至第三光束的物镜光学单元的放大率具有几乎相同的值。 第一光程差提供结构提供预定的光程差，并且将球面像差改变为对于所有第一光通量，第二光通量和第三光通量的校正和过校正之一。 第二光程差提供结构提供预定的光程差，并且将球面像差改变为仅用于第二光通量的球面像差的校正不足和过校正。