发明名称 |
OPTICAL DISK APPARATUS |
摘要 |
It is intended to provide an optical disk apparatus which detects a light amount greater than zero even when used in conjunction with an optical disk substrate having a large birefringence, so that it is possible to properly read a signal without errors and properly perform optical disk controls. The optical disk apparatus includes: a light source for emitting light; an objective lens for converging the light onto a signal surface of an optical disk; a polarized beam diffraction element for diffracting the light reflected from the optical disk; a photodetector for detecting the light diffracted from the polarized beam diffraction element; and a wavelength plate disposed between the optical disk and the polarized beam diffraction element. The wavelength plate has a two-dimensional array of a plurality of birefringent regions including first and second regions, the first and second regions differing in birefringent phase difference and/or optic axes from each other, and the plurality of birefringent regions including the first and second regions cause the light to have different polarization states.
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申请公布号 |
US2009034401(A1) |
申请公布日期 |
2009.02.05 |
申请号 |
US20080183250 |
申请日期 |
2008.07.31 |
申请人 |
MATSUSHITA ELECTRIC INDUSTRIAL CO., LTD. |
发明人 |
NISHIWAKI SEIJI;MOMOO KAZUO;ASADA JUN-ICHI;OTANI KENJI;KANDA YUSUKE |
分类号 |
B05D5/06;C08F2/48;G11B7/0065;G11B7/135 |
主分类号 |
B05D5/06 |
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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