Patent · US Expired

Measuring head

US4078858A · kind A · utility

12Cited by
3References
11Claims
0Family size

Assignee

Inventor

Key dates

Filing dateDec 27, 1976
Grant dateMar 14, 1978
Priority date
Expiry dateDec 27, 1996

Classification

  • Technology area (CPC G)Physics
  • CPC primaryG01N21/474
  • WIPO fieldMeasurement
  • WIPO sectorInstruments

Abstract

A head for measuring light diffusely reflected from a surface, the head having an optical projection system for projecting light onto a surface to be measured, and another optical system for collecting the light diffusely reflected from that surface and imaging it on a photodiode. The collecting optics comprise a spherical annular mirror coaxially aligned with an annular transparent planar member which has an annular plane mirror mounted underneath it, the projected light passing through the apertures in the annular mirror, the planar member, and the annular planar mirror. The light diffusely reflected from the surface to be measured passes through the planar member onto the spherical mirror which reflects it back through the member onto the planar mirror which in turn reflects it back through the planar member onto reducing optics which images the reflected light onto the photo-diode.

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