Patent ID: 9625382
Date: 2017-04-18
CPC Classifications: G01N

Claim:
1. An apparatus of measuring a small scale property of a sheet, the apparatus comprising: a first light source comprises at least one of the following: led and laser, and the first light source is configured to illuminate the sheet moving with respect to the illumination; a detector configured to form a total intensity of reflection of the light illuminating a detected spot on the moving sheet by each detection; a detected dimension of the reflection of the spot on the sheet in the direction of the movement being limited the same as or shorter than a lowest acceptable spatial resolution of the measurement; a duration of each detection being equal to or shorter than the lowest acceptable spatial resolution divided by a speed of the moving sheet; and at least one processor configured to form information about a small scale variation of gloss of the sheet on the basis of the detections by the detector.