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:
Jan. 08, 2008
Filed:
Sep. 27, 2004
Masaaki Hanebuchi, Nukata-gun, JP;
Mitsuhiro Gono, Toyokawa, JP;
Mikio Kurachi, Hazu-gun, JP;
Naoki Isogai, Nishio, JP;
Masaaki Hanebuchi, Nukata-gun, JP;
Mitsuhiro Gono, Toyokawa, JP;
Mikio Kurachi, Hazu-gun, JP;
Naoki Isogai, Nishio, JP;
Nidek Co., Ltd., Gamagori-shi, JP;
Abstract
An eye refractive power measurement apparatus which is capable of measuring even an eye with a small pupil diameter and measuring a normal eye with a large enough pupil diameter with accuracy and stability. The apparatus includes a measurement optical system for photo-receiving measurement light from a fundus via a ring-shaped aperture arranged at an approximately conjugate position with a pupil by using a photodetector, a changing device for changing a size of the ring-shaped aperture on a pupillary surface to a size different in both inside diameter and outside diameter, and a calculation device for calculating the eye refractive power based on a photo-receiving result obtained by the photodetector.