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Patent Searching and Data


Title:
OPTICAL PICKUP DEVICE
Document Type and Number:
Japanese Patent JPH0991749
Kind Code:
A
Abstract:

To provide an optical pickup device capable of restraining occurrence of a coma aberration even though optical axes of an objective lens and a correction optical lens are deviated.

This optical pickup device reproduces two kinds of optical disks 2A, 2B having different thicknesses and uses a zero-order diffracted light L1 to reproduce the optical disk having the thickness designed in an objective lens 7 and uses a 1st-order diffracted light L2 to reproduce the optical disk having the other thickness by providing a correction optical element 6 for performing an aberration correction in an optical path. The aberration correcting amount of the 1st-order diffracted light is constituted to be smaller than an aberration generated due to the difference in the thicknesses of the two kinds of optical disks. Consequently, even though the optical axes of the objective lens 7 and the correction optical element 6 are deviated, the increased amount of the coma aberration is made smaller than the increased amount in the case of complete aberration correction.


Inventors:
ITONAGA MAKOTO
Application Number:
JP27052595A
Publication Date:
April 04, 1997
Filing Date:
September 25, 1995
Export Citation:
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Assignee:
VICTOR COMPANY OF JAPAN
International Classes:
G02B5/32; G02B13/00; G11B7/135; (IPC1-7): G11B7/135; G02B5/32; G02B13/00
Attorney, Agent or Firm:
Akihiro Asai