Title:
対物レンズ、光ピックアップ装置及び光情報記録再生装置
Document Type and Number:
Japanese Patent JP4636213
Kind Code:
B2
Abstract:
Disclosed are an optical pick-up device, an optical information recording/reproducing device, and an objective preferable therefor enabling achievement of compatibility among three types of optical discs, i.e., BDs, DVDs, and CDs by means of a common objective and enabling the working distance of the CDs to be adequately ensured. The objective is provided with a first optical path difference imparting structure wherein the fundamental structures are superimposed in such a way that the step in the fundamental structure in which the order of diffraction of the blue-violet laser beam is an odd order is directed in the opposite direction from the optical axis, and the direction of the step in the fundamental structure in which the order of diffraction of the blue-violet laser beam is an even order is directed toward the optical axis.
Inventors:
Kentaro Nakamura
Application Number:
JP2010534703A
Publication Date:
February 23, 2011
Filing Date:
May 06, 2010
Export Citation:
Assignee:
Konica Minolta Opto Co., Ltd.
International Classes:
G11B7/135; G02B13/10; G02B13/18
Domestic Patent References:
| JP2006134366A | 2006-05-25 |
Foreign References:
| WO2008136242A1 | 2008-11-13 | |||
| WO2006095583A1 | 2006-09-14 | |||
| WO2010013616A1 | 2010-02-04 |