发明名称 |
OPTICAL DISC MEDIUM AND OPTICAL DISC DEVICE |
摘要 |
When using an optical disc medium that includes pit trains having their widths narrower than a diffraction limit, it is difficult to detect a tracking error signal and take a tracking-servo control while increasing pit density in a direction orthogonal to a pit-train extension direction. Information pit trains are arranged spirally or concentrically and formed in a structure in which their depths are changed periodically at a pitch radially along the optical disc medium, so that the tracking error signal can be obtained by push-pull detection of diffraction light from the structure. |
申请公布号 |
US2009303850(A1) |
申请公布日期 |
2009.12.10 |
申请号 |
US20070375138 |
申请日期 |
2007.05.22 |
申请人 |
MITSUBISHI ELECTRIC CORPORATION |
发明人 |
NAKAI KENYA;SHINODA MASAHISA;TAKESHITA NOBUO |
分类号 |
G11B20/18;G11B7/24 |
主分类号 |
G11B20/18 |
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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