发明名称 |
Optical information reproduction method and apparatus |
摘要 |
In an optical information reproduction apparatus having optical beam sources having at least two types of wavelengths, an object lens may be damaged by colliding with an information recording medium while driving a focus servo, which is caused by a fake signal generated due to an incompatibility of the wavelength in use with the information recording medium. To solve such a problem, in case the type of the information recording medium is unrecognizable and a focus servo is led in by using the optical beam source having the first wavelength, the focus servo is led in by using the second focus servo lead-in unit which is driven by an output of a near focus point detection unit during an operation of a second focus search unit which renders the object lens move away from the information recording medium.
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申请公布号 |
US7362667(B2) |
申请公布日期 |
2008.04.22 |
申请号 |
US20040986300 |
申请日期 |
2004.11.12 |
申请人 |
MATSUSHITA ELECTRIC INDUSTRIAL CO., LTD. |
发明人 |
KITANO EMI;NAKAMURA MASAYOSHI;NAKAYAMA YOSHIYASU;UEDA YASUO |
分类号 |
G11B7/00;G11B5/58;G11B7/085;G11B7/09;G11B7/12 |
主分类号 |
G11B7/00 |
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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