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. 10, 1985
Filed:
Jul. 30, 1984
Shuji Hoshika, Saitama, JP;
Hideyuki Ishiai, Tokyo, JP;
Yukiyasu Nishikawa, Saitama, JP;
Masato Hara, Tokyo, JP;
Hirochika Aiura, Saitama, JP;
Ikuzo Okamoto, Saitama, JP;
Osamu Shindow, Tokyo, JP;
Asahi Kogaku Kogyo Kabushiki Kaisha, Tokyo, JP;
Abstract
A method and apparatus for measuring eye refraction errors in which a plurality of infrared patterns are projected onto an eye to be measured. The reflected light is directed onto corresponding light sensitive detectors the outputs of which are coupled through bandpass filters, an automatic gain control circuit and an A/D converter to a microprocessor. The microprocessor analyses the digitized outputs calculating refraction powers in accordance with a disclosed nonlinear regression technique. The refraction errors of the eye, along with a reliability coefficient, are calculated in accordance with the thusly determined refraction powers.