Geometric measurement system and method of measuring a geometric characteristic of an object
AssigneeAMO Wavefront Sciences, LLC
InventorsDaniel R. Neal, Thomas Daniel Raymond, William Shea Powers
Life of this patent
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Abstract
A geometric measurement system is adapted to precisely measure one or more surfaces of objects such as corneas, molds, contact lenses in molds, contact lenses, or other objects in a fixture. The geometric measurement system can employ one or more of three possible methods of measurement: Shack-Hartmann wavefront sensing with wavefront stitching; phase diversity sensing; and white light interferometry.
Claims18
A system for determining at least one geometric characteristic of an object having a first surface and a second surface, wherein at least one of the first and second surfaces passes a substantial amount of light therethrough, the system comprising:
- a light source adapted to illuminate the object;
- an optical element adapted to receive light from the first and second surfaces of the object and to produce a first light beam corresponding to light from the first surface of the object and a second light beam corresponding to light from the second surface of the object;
- a light intensity detector having a radiation sensitive surface adapted to receive the first and second light beams and to detect the intensity of incident radiation on the radiation sensitive surface from the first and second light beams, and to produce an output that provides a measure of the intensity of the incident radiation;
- a translator adapted to adjust relative positions of the optical element and the light intensity detector;
- and
- a processor adapted to determine wavefronts of the light from the first and second surfaces based on the output of the light intensity detector at a plurality of different relative positions.
A method of determining at least one geometric characteristic of an object having a first surface and a second surface, wherein at least one of the first and second surfaces passes a substantial amount of light therethrough, the method comprising:
- (a) illuminating the object;
- (b) transmitting light from the first and second surfaces of the object through an optical element to produce a first light beam corresponding to light from the first surface of the object and a second light beam corresponding to light from the second surface of the object;
- (c) detecting the intensity of incident radiation on a radiation sensitive surface from the first and second light beams;
- (d) adjusting relative positions of the optical element and the radiation sensitive surface, and at each of a plurality of different relative positions producing an output that provides a measure of the intensity of the incident radiation;
- and
- (e) determining wavefronts of the light from the first and second surfaces of the object based on the outputs produced at each of the different relative positions.
A system for determining at least one geometric characteristic of an object having a first surface and a second surface, wherein at least one of the first and second surfaces passes a substantial amount of light therethrough, the system comprising:
- a light source adapted to illuminate the object;
- a diffractive optical element adapted to receive light from the first and second surfaces of the object and to produce therefrom at least two spatially-separated light distributions having at least one statistical characteristic different from each other;
- a light intensity detector having a radiation sensitive surface adapted to receive the at least two spatially-separated light distributions, to detect the at least two spatially-separated light distributions at different points across the radiation sensitive surface, and to produce an output that provides a measure of the intensity of the incident radiation at the different points;
- and
- a processor adapted to determine wavefronts of the light from the first and second surfaces based on the output of the light intensity detector.
A method of determining at least one geometric characteristic of an object having a first surface and a second surface, at least one of the first and second surfaces passing a substantial amount of light therethrough, the method comprising:
- (a) illuminating the object;
- (b) transmitting light from the first and second surfaces of the object through a diffractive optical element to produce therefrom at least two spatially-separated light distributions having at least one statistical characteristic different from each other;
- (c) detecting the intensity of incident radiation on a radiation sensitive surface from the at least two spatially-separated light distributions at different points on the radiation sensitive surface to produce an output that provides a measure of the intensity of the incident radiation at the different points;
- (d) determining wavefronts of the light from the first and second surfaces of the object based on the output of the detection.
Dependencies are inferred from the claim text.