The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
May. 13, 1986
Filed:
Oct. 26, 1982
Hiroshi Tamaki, Tokyo, JP;
Tokyo Kogaku Kikai Kabushiki Kaisha, Tokyo, JP;
Abstract
A curvature measuring apparatus is provided for measuring the radii of curvature of a curved surface, particularly a human cornea or a contact lens. The apparatus comprises an illuminating optical system which illuminates the surface to be measured. The optical system includes a light source for forming a pattern of radiating beams of at least two groups, with each group being comprised of at least two parallel straight lines in a virtual plane. The straight lines in one group are different in directions of arrangement from the straight lines in the other group, and each group includes at least one line whose characteristics are substantially different from the other lines in the group to serve as a reference line. A collimator lens orients principal rays of illuminating beams of light emitted from the light source through a pin hole arranged on an optical axis, to be parallel to the optical axis so as to illuminate the surface to be measured by the illuminating beams of light. A detector is provided which is positioned in a virtual plane which is afocal with the plane containing the light source, for detecting the illuminating beams of light reflected from the surface. An arithmetic calculator calculates a radius of curvature of the surface from changes in inclination and pitch which are produced between a pattern of projected straight lines and the pattern of radiating beams from the light source.