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:
Dec. 14, 1999
Filed:
Jun. 22, 1998
Robert H Webb, Lincoln, MA (US);
Stephen A Burns, Reading, MA (US);
Carl Murray Penney, Saratoga Springs, NY (US);
Schepens Eye Research Institute, Boston, MA (US);
Abstract
A refractometer provides a reference path coaxial with a measurement path and thereby simplifies construction by reducing the number of parts and simplifies maintenance by halving the number of optical axes to be aligned. The refractometer includes a reference projector for projecting a reference pattern on a reference pattern position on a detector during a reference interval, a site-selector for selecting a measurement site on an optical system, and a measurement projector for projecting a measurement pattern through this selected measurement site and onto a measurement pattern position on the detector during a measurement interval. The reference projector, the site selector, and the measurement projector are all aligned along the same optical axis. In the case in which the optical system is a human eye, the designated site in typically a site on the cornea and the detector is the retina of the eye. The refractometer provides an aligner for alignining the reference pattern position with a measurement pattern position. The amount by which these two positions are moved in order to achive alignment provides a measure of the optimal wavefront corresponding to the measurement site.