Evolute tester for optical surfaces
OwnerTerrell E Kokeninventor
Life of this patent
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Abstract
Systems and methods for testing and characterization of optical surfaces which works equally well on concave, flat, convex, and non-conic optical surfaces, and which does not require that a master surface be first produced. The method is automatic and requires little human intervention. It provides an extremely high degree of accuracy, and provides repeatability of measurements within a minuscule tolerance of error. The method determines the evolute of the surface automatically, deterministically, and repeatably via orthogonal reflection by ascertaining the evolute of the surface's figure along multiple diameters of the surface.
Claims20
A method for precisely and accurately characterizing an optical surface by using orthogonal specular reflection of a coherent monochromatic beam of light to reconstruct the evolute of the curve of the surface, the method including:
- transmitting a coherent monochromatic light beam multiple times, from incrementally successive positions across the optical surface being characterized, using a laser generating a monochromatic laser beam, and performing the following steps at each position:
- sensing, and measuring an intensity of, a reflection of the laser beam from each incrementally successive position on the optical surface using a sensor;
- transmitting a value of the intensity of the reflection of the laser beam to a microprocessor;
- controlling and measuring a position from which the laser beam that strikes the optical surface originates;
- reporting the position to the microprocessor as an intercept position;
- controlling and measuring a beam direction from which the laser beam that strikes the optical surface originates, the beam direction having a slope;
- reporting the slope of the beam direction to the microprocessor;
- controlling the beam direction to maximize the intensity;
- mathematically constructing a straight line, from the slope of the beam direction at each intercept position having maximum intensity, which straight line is constrained thereby to be orthogonal to the optical surface and thus tangent to the evolute of the surface, for each incrementally successive position across the optical surface, until the incrementally successive positions have crossed the entire surface, wherein a set of the straight lines comprises the envelope of the evolute of the optical surface.
A method for precisely and accurately characterizing an optical surface by using orthogonal specular reflection of a coherent monochromatic beam of light to reconstruct the evolute of the curve of the surface, the method including:
- sequentially transmitting a coherent monochromatic light beam from incrementally successive positions across the optical surface being characterized using a laser;
- sensing and measuring an intensity of a reflection of the light beam from each incrementally successive position on the optical surface using a sensor;
- transmitting values of the intensity of each reflection of the light beam to a microprocessor;
- controlling and measuring a position from which the light beam that strikes the optical surface originates;
- reporting the position to the microprocessor as an intercept position;
- controlling and measuring a beam direction from which the light beam that strikes the optical surface originates, the beam direction having a slope;
- reporting the slope of the beam direction to the microprocessor;
- controlling the beam direction to maximize the intensity;
- and
- mathematically constructing a straight line, from the slope of the beam direction at each intercept position having maximum intensity, for each incrementally successive position across the optical surface, until the incrementally successive positions have crossed the entire surface, wherein a set of the straight lines comprises the envelope of the evolute of the optical surface.
Dependencies are inferred from the claim text.