Patent · US Expired

Portable spectrophotometer

US5369481A · kind A · utility

87Cited by
7References
4Claims
0Family size

Assignee

Inventors

Key dates

Filing dateMay 8, 1992
Grant dateNov 29, 1994
Priority date
Expiry dateMay 8, 2012

Classification

  • Technology area (CPC G)Physics
  • CPC primaryG01N2201/065
  • WIPO fieldMeasurement
  • WIPO sectorInstruments

Abstract

A portable spectrophotometer includes a small-diameter optical sphere as well as optical detectors and signal processing and display circuitry which allows the instrument to be taken to an object to be measured and which provides a readout of color values at the portable instrument. The instrument is capable of providing specular-included and specular-excluded color readings simultaneously. The interior of the integrating sphere is coated with a highly reflective, color-absorbing material, and light from an incandescent lamp is diffused within the sphere prior to reaching the object to be measured. The sphere is provided with a first aperture which receives spectrally-included light and which is positioned to absorb a spectral component of the diffused source light. A second aperture positioned at a corresponding angular position with respect to the object measures specular-excluded light, excluding the specular component absorbed by the first aperture. Light detected from the first aperture is analyzed at a plurality of wavelengths obtained by the use of interference filters, and the light obtained from the second aperture is analyzed at one of the plurality of wavelengths. By app…

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.