Optics: eye examining – vision testing and correcting – Eye examining or testing instrument – Objective type
Patent
1992-05-01
1995-12-05
Shafer, Ricky D.
Optics: eye examining, vision testing and correcting
Eye examining or testing instrument
Objective type
351212, 351213, 351214, 351246, 351221, A61B 310
Patent
active
054733928
ABSTRACT:
The invention is a system and method of measuring the shape of a surface. The corneal topographer specifically shown comprises a transparent rigid reference member having a reference surface of a predetermined shape, a conformable substance capable of assuming the conformation of surfaces being pressed against, a light source for irradiating the conformable substance pressed between the reference surface and the corneal surface, and a detection system for detecting light propagating from the reference member and carrying information about the thickness. Two specific designs are shown, both based on differential topography. The first design uses a fluorescent conformable substance which fills the space between the reference surface and the corneal surface. The local intensity of fluorescent radiation detected by the detection system is correlated to the local thickness of the fluorescent conformable substance. The second design utilizes an absorbing conformable substance with a diffusive reflecting surface forming the section of the conformable substance pressed against the corneal surface during the measurement process. The local thickness of the absorbing conformable substance is determined from the amount of light locally absorbed. A topographer of the first or the second design can be used to measure the topography of the surface of a solid object of various constructions without regard to the finish of the surface, e.g., specular reflective, diffusely reflective or non-reflective.
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Shafer Ricky D.
Summit Technology Inc.
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