发明公开
- 专利标题： Focus detector
- 专利标题（中）： 聚焦检测器
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申请号： EP87307745申请日： 1987-09-02
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公开(公告)号： EP0259148A3公开(公告)日： 1988-11-30
- 发明人: Matsui, Hiroshi , Koyama, Osamu , Yano, Hideaki , Nakamura, Yasuo
- 申请人： CANON KABUSHIKI KAISHA , CANON DENSHI KABUSHIKI KAISHA
- 专利权人： CANON KABUSHIKI KAISHA,CANON DENSHI KABUSHIKI KAISHA
- 当前专利权人： CANON KABUSHIKI KAISHA,CANON DENSHI KABUSHIKI KAISHA
- 优先权： JP21003186 19860905
- 主分类号： G11B07/09
- IPC分类号： G11B07/09 ; G02B07/11 ; G02B27/16
摘要：
A focus detector which comprises as follows:
means (1 to 4) for irradiating a focused light beam to a surface (5) to be examined;
an optical element (7) located in a vicinity of a focus point of a detection light beam formed by the irradiation light beam reflected by or passed through the surface and refocused;
said optical element splitting a portion of the detection light beam only when the irradiation light beam is not in an in-focus state on the surface; and means (10) for receiving the light beam split by said optical element so as to detect a focus error signal.
means (1 to 4) for irradiating a focused light beam to a surface (5) to be examined;
an optical element (7) located in a vicinity of a focus point of a detection light beam formed by the irradiation light beam reflected by or passed through the surface and refocused;
said optical element splitting a portion of the detection light beam only when the irradiation light beam is not in an in-focus state on the surface; and means (10) for receiving the light beam split by said optical element so as to detect a focus error signal.
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