Luster rating method and apparatus
US4717259A · kind A · utility
Inventor
Key dates
| Filing date | Mar 21, 1985 |
| Grant date | Jan 5, 1988 |
| Priority date | — |
| Expiry date | Mar 21, 2005 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01N21/57
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A method and apparatus for determining the luster of a surface as a numerical value. The apparatus projects light from a light source through a light diffusing layer and through a layer of semitransparent material having thereon groups of parallel lines for projecting the lines onto the surface of a sample the luster of which is to be determined. The lines projected onto the surface are viewed with the eyes and the degree of distortion among the lines in the respective groups, which occurs due to the various conditions of the surface which affect the luster thereof, and to which has previously been assigned a numerical value, is determined, the numerical value of the thus determined degree of distortion for one group of figures being for the degree of gloss of the surface and the numerical value of the thus determined degree of distortion for another group being for the degree of clarity of the surface. The surface is also visually compared with a scale of predetermined lightness values having preassigned numerical values for determining the closest lightness value, and a lightness coefficient is derived from this lightness value. The sum of the gloss value and the clarity value is…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.