专利内容由知识产权出版社提供
专利名称：OPTICAL PICKUP AND OPTICAL
INFORMATION PROCESSING DEVICE
发明人：HAMANO, YUKIKO,HIRAI,
HIDEAKI,NASUKAWA, TOSHIMICHI,UMEKI,KAZUHIRO
申请号：EP08740773申请日：20080415公开号：EP2168124A4公开日：20100804
摘要：A disclosed optical pickup includes an aberration correction unit with a phaseshifter surface. On the phase shifter surface, rectangular or staircase- like steps areformed in a concentric manner around an optical axial center, in certain regions where alight beam passes through. The steps have different heights in the optical axial direction.A light beam having a wavelength of 405 nm is directly transmitted through the steps sothat a phase difference is applied for correcting spherical aberration that occurs on a firstoptical recording medium. A light beam that passes through an annular region withoutany steps is focused on a second optical recording medium. A light beam that passesthrough an outside region is focused by an object lens on the second optical recordingmedium, and is not focused on the first optical recording medium.
申请人：RICOH COMPANY, LTD.
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