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:
Sep. 16, 1986
Filed:
Apr. 19, 1982
Paul S Sugino, Santa Maria, CA (US);
Other;
Abstract
The disclosure concerns the determination of the ophthalmic parameters of a thin astigmatic optical element without requiring initial location of its cylindrical axis. The effective optical power of the eye or other element is measured in three mutually spaced meridians that are selected without regard for the cylindrical axis. The ophthalmic parameters of the element, typically the spherical power, the cylindrical power and the cylindrical axis, are then derived from the measured powers and their selected meridian angles. The power of an astigmatic element in a selected meridian intermediate the principal meridians may be determined in generally conventional manner by adjusting a test optical system to produce a sharp image of a suitable target, preferably with limitation of the image-forming light to rays that traverse the element close to the selected meridian. Also disclosed is a method of establishing correct focus of such a test system in terms of the lateral magnification of the target image rather than its sharpness. For that purpose the test system is typically of Badal type with effective aperture stop axially spaced from the element under test.