Horizontal position detecting device
Patent 4558949 Issued on December 17, 1985. Estimated Expiration Date: 
December 17, 2002. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.
December 17, 2002. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.Patent References 3541338 3645623 3880524 Optical imaging system provided with an opto-electronic detection system for determining a deviation between the image plane of the imaging system and a second plane on which an image is to be formed Optical imaging apparatus Patent #: 4477185 InventorsAssigneeApplicationNo. 06/419514 filed on 09/17/1982US Classes:356/139.07, With photodetection of reflected beam angle with respect to a unidirectional source beam250/559.38, Determining range from detector356/152.2, With reflection of a unidirectional source beam from a planar or nonretroreflective surface356/3.08, With at least one paired set of staring photodetectors356/400, With light detector (e.g., photocell)356/614POSITION OR DISPLACEMENTExaminersPrimary: Buczinski, S. C.Attorney, Agent or FirmInternational ClassG03F 9/00 (20060101)Foreign Application Priority Data1981-12-26 JPAbstractDisclosed is a horizontal position detecting device for maintaining the surface of a body to be inspected vertically to the optical axis of a main objective lens. The device includes an illumination optical system and a condenser lens system. The illumination optical system supplies parallel light rays to the surface of the body from the direction oblique to the optical axis of the objective lens. The condenser lens system condenses the light rays supplied by the illumination optical system and reflected by the surface of the body. The optical axes of the illumination optical system and the condenser lens system are arranged substantially symmetrically with respect to the axis of the objective lens.Other References
Field of SearchWith light detector (e.g., photocell) | |
