초록 ▼

A method and apparatus for photogoniometric analysis of surfaces is disclosed. A photogoniometric instrument includes a light source (12) for providing a collimated beam of light illuminating a test surface (18). A light detector (20) is mounted for rotation about the point of intersection of the il

A method and apparatus for photogoniometric analysis of surfaces is disclosed. A photogoniometric instrument includes a light source (12) for providing a collimated beam of light illuminating a test surface (18). A light detector (20) is mounted for rotation about the point of intersection of the illuminating beam on the test surface. A motor (44) drives the detector through a range of reflectance angles, and a microcomputer (52) digitizes the detector output periodically, storing the digitized data words in its memory (68). These stored words define a photogoniometric curve (FIG. 2A) including a specular portion (FIG. 2D) and a nonspecular, or diffuse, portion (FIG. 2C). A host computer (62) receives the photogoniometric data from the microcomputer, deconvolutes the data into spectral and diffuse portions, and analyzes the two portions separately from one another. To accomplish this deconvolution, the host computer subtracts from the photogoniometric data the actual reflectance characteristic of a standard surface whose characteristic lacks the specular peak. This diffuse standard reflectance characteristic is stored in the host computer memory in the form of a mathematical equation which has been curve fitted to the actual reflectance characteristics of the diffused standard.

대표청구항 ▼

A method of analyzing the specular reflectance characteristics of a test surface comprising the steps of: illuminating said test surface with a collimated beam of light incident on said surface at a known angle, measuring the reflectance characteristics of said test surface by measuring the intensit

A method of analyzing the specular reflectance characteristics of a test surface comprising the steps of: illuminating said test surface with a collimated beam of light incident on said surface at a known angle, measuring the reflectance characteristics of said test surface by measuring the intensity of light reflected from said surface at plural selected angles of reflectance, providing a mathematical equation relating reflectance intensity to reflectance angle for a standard surface whose reflectance characteristic substantially lacks a spectral peak, and analyzing the difference between the reflectance characteristics of said test surface and said mathematical equation, said difference representing the spectral reflectance characteristic of said surface.