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:
Mar. 09, 1999
Filed:
Oct. 30, 1996
Robert Nelson McKnight, Andover, MA (US);
Morey Herbert Waltuck, Sharon, MA (US);
John Donal Starr, Georgetown, MA (US);
Kurt Paul Tolksdorf, Islip, NY (US);
Mentor Corporation, Santa Barbara, CA (US);
Abstract
A visual acuity tester based on a personal computer is provided that is capable of displaying visual acuity test characters at varying sizes on a monitor. The visual acuity tester antialiases the test characters to overcome the effects of staircase distortion. Preferably, the visual acuity tester performs unweighted area sampling antialiasing. The visual acuity tester also centers the test characters relative to the pixel array of the monitor to improve the appearance of the test characters. The test characters can be centered relative to either the center of a pixel or the corner of a pixel (a pixel coordinate). Test characters can also be centered relative to a pixel center in one dimension and a pixel coordinate in the other dimension.