Back to results
US 4,049,350 AGranted
Process and apparatus for detecting inclusions
AssigneeDIHACO Diamanten Handels Compagnie Est.
InventorGernot Klaus Bruck
Life of this patent
Estimating the term…
Abstract
A process and apparatus for detecting inclusions in precious stones in which the stone is scanned with light from a laser. The stone is immersed in a liquid of the same refractive index as the stone so that there is no reflection from the outer surfaces of the stone, so that the shape of the stone does not affect the process.
Claims26
A process for detecting the presence and size of inclusions which scatter light in precious stones, comprising:
- scanning the stone, while the stone is submersed below the surface of an immersion fluid having a refractive index substantially equal to the refractive index of the stone for the wavelength of the incident beam, with a concentrated beam of light, the cross-section of which is of the same order of magnitude as the smallest inclusions to be detected and which scatter light from said beam, the scanning taking place over the entire cross-sectional plane of the stone perpendicular to the incident beam and along scanning trajectories separated from one another by a distance not exceeding the beam cross-section;
- and
- measuring, with respect to each position of said concentrated beam of light during said scanning step, the intensity of unscattered light of the beam after it has been subjected to the influence of the stone to the exclusion of light scattered by inclusions.
Apparatus for detecting the presence and size of inclusions which scatter light in stones, comprising:
- a container into which the stone to be examined is insertable with a predetermined alignment;
- an immersion liquid having a refractive index substantially equal to the refractive index of the stone for the wavelength of the incident beam, contained within the container in sufficient quantity to fully immerse the stone;
- a light source for producing a light beam with a cross-section of the same order of magnitude as the smallest inclusions to be detected and which scatter light from said beam;
- an adjusting device for aligning the beam in a particular direction relative to the stone when inserted in the container;
- a moving device for relatively moving the stone and the beam to scan the light beam across the stone;
- and
- means responsive to the intensity of unscattered light from said light beam to the exclusion of light scattered by inclusions for measuring the intensity of said unscattered light with respect to each relative position of the beam and the stone during the scan caused by said moving device.
4 more elements
Dependencies are inferred from the claim text.