发明名称 |
OPTICAL HEAD DEVICE AND OPTICAL DISC DEVICE |
摘要 |
An optical head device mounted in an optical disc device. The optical head device is provided with a diffractive optical element and a photodetector. The diffractive optical element has: a primary diffraction region at a location on which the positive and negative first-order components and some of the zero-order component of a reflectively diffracted light beam are incident; and secondary diffraction regions at locations on which the rest of the zero-order component but none of the positive or negative first-order components of the reflectively diffracted light beam are incident. A main light-receiving section of the photodetector receives the zero-order component of a transmissively diffracted light beam that has passed through the primary diffraction region and the secondary diffraction regions. Secondary light-receiving sections receive the positive first-order component and/or the negative first-order component of the transmissively diffracted light beam that has passed through the secondary diffraction regions.
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申请公布号 |
US2012106310(A1) |
申请公布日期 |
2012.05.03 |
申请号 |
US201113380791 |
申请日期 |
2011.01.17 |
申请人 |
SHINODA MASAHISA;NAKAHARA HIRONORI;OMAKI MASAYUKI;NAKAI KENYA;TAKESHITA NOBUO |
发明人 |
SHINODA MASAHISA;NAKAHARA HIRONORI;OMAKI MASAYUKI;NAKAI KENYA;TAKESHITA NOBUO |
分类号 |
G11B7/1353;G11B7/131;G11B7/1374;G11B7/1392;G11B7/1395 |
主分类号 |
G11B7/1353 |
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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