发明名称 |
Ophthalmoscopic instrument having working position detecting means |
摘要 |
Ophthalmoscopic instrument having working position detector. An object lens has an optical axis and is adapted to be positioned to confront a patient's eye at a working distance. The patient's cornea has a center of curvature. An observing optical system focuses a light beam reflected from the eye and passing through an objective lens on an image plane. A detecting system detects that the eye is properly positioned with respect to the objective lens. The detecting system includes at least two apertures allowing light beams from a single target mark to pass therethrough. A target mark projection system projects the beams passed through the respective apertures in directions crossing each other on the optical axis of the objective lens so that a target mark image is formed at the center of curvature of the cornea when the eye is properly positioned with respect to the objective lens. A target mark image plane forms a target mark image by mirror reflection from the cornea of the light beams projected through the target mark projection system when the patient's eye is properly positioned, and a target mark image observation system provides observation of the target mark image on the target mark image plane in superposition with a reference mark.
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申请公布号 |
US4712894(A) |
申请公布日期 |
1987.12.15 |
申请号 |
US19830473454 |
申请日期 |
1983.03.10 |
申请人 |
TOKYO KOGAKU KIKAI KABUSHIKI KAISHA |
发明人 |
NUNOKAWA, KAZUO |
分类号 |
A61B3/113;A61B3/15;(IPC1-7):A61B3/14 |
主分类号 |
A61B3/113 |
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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