发明名称 |
Optical head, optical recording/reproducing apparatus and laser module |
摘要 |
Two light sources radiating two light beams having different wavelengths are simultaneously operated. Reflected beams of these two types of laser beams from an optical recording medium are simultaneously detected by two detectors. When one of the two types of light beams having different wavelengths is used while being focused on an optical recording medium, the spot diameter of the other non-focused metering beam on the optical recording medium is set larger than that of the one of the two light beams. A reflected light having a larger spot diameter is used to reduce DC offset in a tracking error signal.
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申请公布号 |
US6809996(B2) |
申请公布日期 |
2004.10.26 |
申请号 |
US20010871897 |
申请日期 |
2001.06.04 |
申请人 |
TDK CORPORATION |
发明人 |
SHIBUYA GIICHI |
分类号 |
G11B7/00;G11B7/09;G11B7/12;G11B7/125;G11B7/135;(IPC1-7):G11B7/00 |
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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