Method and apparatus for determining the optical properties of a lens
First Claim
1. A device without a moving part for determining optical properties of a lens comprising, means to project a beam of light along a path having an axis, a test plane located on said path, an occluder having a single shaped opening defined by a single border positioned on said path, area detection means responsive to light received from said shaped opening for providing a signal representative of light distribution on said detection means, evaluation means for converting said signal to values representing the optical properties of a lens located at said test plane, and means to report said values.
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Accused Products
Abstract
Optical properties of a lens, including localized defects, are determined by analyzing the refracted image produced by transmitting a beam of light through an aperture and a lens to be tested. The image is reflected onto a light sensitive detecting surface. Information obtained from the light detecting surface is digitized and sent to an Image Processing Unit which calculates the optical properties of the lens. The aperture may consist of a single shaped opening or alternatively a plurality of concentric, annular rings. Correction lenses may be employed, either permanently or selectively, to alter the refracted beam before the beam intersects the detecting surface.
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Citations
56 Claims
- 1. A device without a moving part for determining optical properties of a lens comprising, means to project a beam of light along a path having an axis, a test plane located on said path, an occluder having a single shaped opening defined by a single border positioned on said path, area detection means responsive to light received from said shaped opening for providing a signal representative of light distribution on said detection means, evaluation means for converting said signal to values representing the optical properties of a lens located at said test plane, and means to report said values.
- 27. An instrument for determining the optical properties of a lens comprising, an illumination source, a path extending from said source, means for projecting a beam of light along said path, a test plane located on said path, area detection means for receiving light from said test plane and producing a first signal representing the size and shape of light distribution on said detection means, means for producing an edge coordinate signal from said first signal utilizing an edge determining algorithm, evaluation means for comparing said edge coordinate signal to a reference signal and converting a difference between said signals to values indicating optical properties of a lens located at said test plane, and means to report said values.
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51. A method of determining optical properties of a lens which comprises,
projecting a collimated beam of light through a test plane onto an occluder having a central shaped opening, producing a first signal representative of the size and shape of a detector area illuminated by a small bundle of rays passing through said shaped opening, processing said first signal utilizing an edge determining algorithm to produce an edge coordinate reference signal, storing said reference signal, placing a lens to be evaluated at said test plane to refract said beam, producing a second signal representative of the size and shape of said detector area illuminated by another bundle of rays from said refracted beam passing through said shaped opening, processing said second signal utilizing an edge determining algorithm to produce an edge coordinate test signal, comparing said reference and test signals to determine optical properties of said lens, and reporting said properties.
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53. A method of determining optical properties of a lens which comprises,
projecting a collimated beam of light first through an occluder having a central shaped opening, then through a test plane, producing a first signal representative of the size, shape and location of a detector area illuminated by a bundle or rays passing through said shaped opening, processing said first signal utilizing an edge determining algorithm to produce an edge coordinate reference signal, storing said reference signal, placing a lens to be evaluated at said test plane to refract said beam, producing a second signal representative of the size, shape and location of said detector area illuminated by another bundle of rays from said refracted beam passing through said shaped opening, processing said second signal utilizing an edge determining algorithm to produce an edge coordinate test signal, comparing said reference and test signals to determine optical properties of said lens, and reporting said properties.
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55. A method of determining the optical properties of a lens which comprises,
A) projecting a beam of light through a test lens to provide a refracted beam of light, B) illuminating an area detector having a plurality of rows, each row containing a plurality of pixels, with said refracted beam, C) scanning each row of pixels to produce a digitized signal representative of crude physical parameters representing the size and shape of said illuminated area, D) processing said digitized signal using an edge determining algorithm to produce a digitized edge coordinate signal, E) converting said digitized edge coordinate signal into enhanced physical parameters representing the size, shape and location of said illuminated area, and F) calculating optical properties of said lens using said enhanced physical parameters.
Specification