Patent · US Expired

Examining a gemstone

US4529305A · kind A · utility

22Cited by

2References

21Claims

0Family size

Inventors

Walter T. Welford · London, GB
Andrew D. G. Stewart · Reading, GB
John S. Dodson · Cobham, GB

Key dates

Filing date	Jul 6, 1982
Grant date	Jul 16, 1985
Priority date	—
Expiry date	Jul 6, 2002

Classification

Technology area (CPC G)Physics
CPC primaryG01N21/87
WIPO fieldMeasurement
WIPO sectorInstruments

Abstract

Method and apparatus for examining a gemstone to determine a parameter thereof. A thin beam of light is projected onto the stone, the beam is moved relative to the stone, the position where the beam strikes the stone is sensed in a direction different from that in which the beam is projected, and a parameter is determined making use of information derived from such sensing.

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