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:
Feb. 01, 1994
Filed:
Feb. 27, 1992
Charles F McMillan, Livermore, CA (US);
William D Fountain, Fremont, CA (US);
Carl F Knopp, San Mateo, CA (US);
Phoenix Laser Systems, Inc., Fremont, CA (US);
Abstract
An improved apparatus and technique are disclosed for illuminating the cornea with points of light for analysis of the specularly reflected return light in determining the shape of the cornea. In combination with an optical illumination system which forms real images of points of light inside or in the path of the objective lens, the system of the invention includes a plurality of real light source points optically peripheral to the real image points and physically outside to the objective lens. The sources of the point light sources may be optical fibers or LEDs arranged in an array which optically extends radially outward from the objective lens, although the external points may be forward or back from the objective lens. The two types of point light sources are generally registered in a pattern and together form an ordered geometric array for providing paraxial reflections off the cornea over a wide area of the cornea, including both central and peripheral areas of the cornea.