Patent ID: 6061121
Filing Date: 2000-05-09
Classification: G01N,G07D

Abstract:
An apparatus for testing sheet material, said sheet material being transported during said testing at a transport speed in a transport direction, havingan illumination device which illuminates the sheet material with light,a receiving device which receives light from said illumination device that is diffusely reflected by the sheet material and/or transmitted through the sheet material and that converts the light into corresponding electric signals,an evaluation device which processes the signals and compares them with reference data for testing the sheet material,whereinthe illumination device (20) illuminates the sheet material (10) uniformly in a total spectral region to be tested, andthe receiving device (30) has at least two linear parallel CCD arrays (Z.1-Z.4),which are mounted on a carrier (34),each CCD array (Z.1-Z.4) being provided with a filter (F.1-F.4), each said filter being mounted on a respective one of said CCD-arrays and arranged to transmit a certain spectral region, andat least one filter mounted on a first of said CCD-arrays transmitting said light in the visible spectral region and at least one filter mounted on a second of said CCD-arrays transmitting said light in the invisible spectral region.