发明名称 |
Optical pick-up apparatus. |
摘要 |
<p>Not more than one compound holographic optical element is provided on an optical path starting from a semiconductor laser chip and arriving at a photo detector via an optical disk. A hologram pattern of this compound holographic optical element is the superposition of a first hologram pattern, converging a laser beam emitted from the semiconductor laser chip onto the optical disk, and a second hologram pattern, diffracting the laser beam reflected at the optical disk toward the photo detector and changing it into a focusing beam. This single holographic optical element not only realizes the convergence of the laser beam onto the optical disk and/or the photo detector and the differentiation of going and returning optical paths but reduces the size and production cost of the optical pick-up apparatus. <IMAGE></p> |
申请公布号 |
EP0581519(A2) |
申请公布日期 |
1994.02.02 |
申请号 |
EP19930305753 |
申请日期 |
1993.07.21 |
申请人 |
MATSUSHITA ELECTRIC INDUSTRIAL CO., LTD |
发明人 |
HORINOUCHI, SYOUGO |
分类号 |
G11B7/12;G11B7/125;G11B7/135;(IPC1-7):G11B7/12;G11B7/13 |
主分类号 |
G11B7/12 |
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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