Method and apparatus for measuring total specular and diffuse optical properties from the surface of an object
First Claim
1. A device for measuring total specular and diffuse optical properties from the surface of an object by means of electromagnetic radiation, comprising:
- a. a housing defining an ellipsoidal chamber having a reflective interior surface, a first focus, an opposite second focus and the chamber defining a first aperture at the first focus, the first aperture being adapted for placement against the surface of the object so that a portion of the surface is in optical communication with the chamber;
b. means for illuminating the portion of the surface of the object with the electromagnetic radiation of a predetermined waveband; and
c. means for measuring the radiation, disposed adjacent the second focus, so that when the first aperture is placed against the object, the electromagnetic radiation illuminates the object in an area adjacent the first focus with the reflected radiation, both specular and scattered, being directed by the reflective interior surface to the radiation measuring means.
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Accused Products
Abstract
A portable device for measuring total reflectance from the surface of an object by means of electromagnetic radiation has a housing defining an ellipsoidal chamber having a reflective interior surface, a first focus, an opposite second focus. The chamber defines a first aperture at the first focus, the first aperture being adapted for placement against the surface of the object so that a portion of the surface is in optical communication with the chamber. A light source illuminates the portion of the surface of the object through the first aperture with the electromagnetic radiation of a predetermined waveband, such as infrared. A means for measuring the radiation is disposed adjacent the second focus, so that when the first aperture is placed against the object, the electromagnetic radiation illuminates the object in an area adjacent the first focus. The reflected radiation, both specular and scattered, is directed by the interior reflective surface to the radiation measuring means. Disposed between the first focus and the second focus is a means for reflecting substantially all of the electromagnetic radiation from the source of focused radiation to the radiation measuring means, thereby providing a reference beam to the radiation measuring means. The ratio of the intensity of the light reflected off of the surface of the object to the intensity of the reference beam provides an indication of the absolute reflectance of the object. Also disclosed is a coating for transducing light into infrared light.
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Citations
40 Claims
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1. A device for measuring total specular and diffuse optical properties from the surface of an object by means of electromagnetic radiation, comprising:
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a. a housing defining an ellipsoidal chamber having a reflective interior surface, a first focus, an opposite second focus and the chamber defining a first aperture at the first focus, the first aperture being adapted for placement against the surface of the object so that a portion of the surface is in optical communication with the chamber; b. means for illuminating the portion of the surface of the object with the electromagnetic radiation of a predetermined waveband; and c. means for measuring the radiation, disposed adjacent the second focus, so that when the first aperture is placed against the object, the electromagnetic radiation illuminates the object in an area adjacent the first focus with the reflected radiation, both specular and scattered, being directed by the reflective interior surface to the radiation measuring means. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16)
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17. A portable device for measuring the total specular and diffuse reflectance from a surface of an object, comprising:
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a. a frame having a bottom side; b. a housing disposed within the frame and defining an ellipsoidal reflector, the reflector comprising a reflective inside surface, a major axis, a first focus and an opposite second focus disposed along the major axis, the reflector truncated by a plane perpendicular to the major axis at the first focus and defining an aperture therethrough, the reflector disposed so that the aperture is adjacent the bottom side of the frame so that when the bottom side of the frame is placed against the surface of the object, a portion of the surface is adjacent the first focus and in optical communication with the inside of the reflector; c. means, disposed within the frame, for illuminating a portion of the surface with electromagnetic radiation having a predetermined wave band; d. means for directing the beam to the portion of the outer surface; and e. means, disposed along a plane perpendicular to the major axis at the second focus, for measuring the intensity of the reflected electromagnetic radiation reflected off of the portion of the surface and for generating a signal representative of the measured intensity. - View Dependent Claims (18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32)
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33. A method for measuring total specular and diffuse reflectance from the surface of an object, comprising the steps of:
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a. placing against the surface of the object an ellipsoidal reflector, having a reflective interior surface, a first focus, an opposite second focus and defining a first aperture at the first focus, the first aperture being adapted for placement against the surface of the object; b. illuminating, with a beam of electromagnetic radiation of a predetermined waveband, a portion of the surface through an aperture in the ellipsoidal reflector; c. reflecting, with the ellipsoidal reflector, a portion of the electromagnetic radiation reflected from the surface of the object, both specular and diffuse, to a detector adjacent the second focus; and d. measuring a value of the reflected radiation with the detector. - View Dependent Claims (34, 35, 36, 37, 38, 39, 40)
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Specification