Optics: eye examining – vision testing and correcting – Eye examining or testing instrument – Objective type
Reexamination Certificate
2007-06-26
2008-08-19
Mack, Ricky L (Department: 2873)
Optics: eye examining, vision testing and correcting
Eye examining or testing instrument
Objective type
C351S214000, C351S222000
Reexamination Certificate
active
07413304
ABSTRACT:
A grid formed with apertures of a predetermined shape is illuminated with light from a lamp and projected onto a tear meniscus accumulated on the lower eyelid. The aperture image projected on the tear film is imaged by a CCD camera. The tear meniscus functions as a concave mirror, so that the magnification factor depends on the radius of meniscus curvature. A processor calculates the magnitude of the grid image and evaluates the radius of meniscus curvature. Since the volume of lacrimal fluid varies depending upon the radius of meniscus curvature, the latter is used as a value representing the lacrimal fluid volume for dry eye diagnose purposes.
REFERENCES:
patent: 4269197 (1981-05-01), Gilbard
patent: 4951683 (1990-08-01), Davis
patent: 5352445 (1994-10-01), Lavaux
patent: 5719659 (1998-02-01), Suzuki
Suzuki Takayoshi
Yokoi Norihiko
Adams & Wilks
Kowa Company Ltd
Mack Ricky L
Thomas Brandi N
Yokoi Norihiko
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