Optics: eye examining – vision testing and correcting – Eye examining or testing instrument – Objective type
Reexamination Certificate
2008-01-08
2008-01-08
Dang, Hung Xuan (Department: 2873)
Optics: eye examining, vision testing and correcting
Eye examining or testing instrument
Objective type
C351S206000, C351S209000, C351S212000, C351S221000
Reexamination Certificate
active
10949297
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.
REFERENCES:
patent: 5463430 (1995-10-01), Isogai et al.
patent: 5523809 (1996-06-01), Kohayakawa
patent: 6002484 (1999-12-01), Rozema et al.
patent: 6079828 (2000-06-01), Fujieda
patent: 6257722 (2001-07-01), Toh
patent: 6409344 (2002-06-01), Hayashi
patent: 05-031075 (1993-02-01), None
patent: 08-103413 (1996-04-01), None
patent: 11-225963 (1999-08-01), None
patent: WO 99/66828 (1999-12-01), None
Gono Mitsuhiro
Hanebuchi Masaaki
Isogai Naoki
Kurachi Mikio
Dang Hung Xuan
Nidek Co. Ltd.
Oliff & Berridg,e PLC
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