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:
Nov. 02, 1999
Filed:
Apr. 29, 1998
Thomas Hellmuth, Aalen, DE;
Carl Zeiss, Inc., Thornwood, NY (US);
Abstract
Embodiments of the present invention are method and apparatus for simultaneously measuring the length and refractive error of an eye, preferably in a non-contact mode. In particular, an embodiment of the present invention is an apparatus which measures length and refractive error of an eye which includes: (a) a source of short coherence radiation which couples radiation into a Michelson interferometer, the arms of the Michelson interferometer having a predetermined optical pathlength difference; (b) an injector which couples radiation output from the interferometer into the eye; and (c) a relay system which couples radiation output from the eye to a spectrometer; wherein the spectrometer measures displacement of radiation to measure the refractive error and the spectrometer measures density of fringes to measure the length.