发明名称 |
Focusing device, focusing method and a pattern inspecting apparatus |
摘要 |
A focusing device comprises a first imaging optical system, a second imaging optical system which splits the optical image in the direction of an AF sensor and further splits the optical image so that a front focus image in which the point that is in focus is in front of the optical image on the inspecting sensor and a back focus image in which the point that is in focus is behind the optical image on the inspecting sensor are formed on the AF sensor, a focus detecting circuit which detects an optimum focus position on the basis of a high-frequency component of a front sensor image in a front focus position and a high-frequency component of a back sensor image in a back focus position, and a focus control circuit which controls the focusing of the first imaging optical system on the basis of the focus position.
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申请公布号 |
US7394048(B2) |
申请公布日期 |
2008.07.01 |
申请号 |
US20070679411 |
申请日期 |
2007.02.27 |
申请人 |
KABUSHIKI KAISHA TOSHIBA;NUFLARE TECHNOLOGY, INC. |
发明人 |
INOUE HIROMU;WATANABE TOMOHIDE;ENDO SATOSHI;IKEDA MASAMI |
分类号 |
G02B7/04 |
主分类号 |
G02B7/04 |
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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