Abstract: A system for detecting bluestain and rot in wood in a wood processing plant including a conveyor for conveying a piece of wood through a scanning area includes a scanning unit comprising a plurality of scanners arranged to scan a face of the piece of wood in a direction perpendicular to a conveying direction. Each of the scanners include a light for illuminating a point on the piece of wood; a collector for collecting light reflected from the piece of wood; a splitter for splitting the collected light into at least two beams; a filter for filtering out of each of the beams a wavelength associated with each of the beams, each of the wavelengths being different; a collector for collecting the filtered light, the collector being adapted to output a signal related to an intensity of the filtered light; and a comparator for comparing the output of each of the collector, the comparator being adapted to output a signal when a ratio between the signal between each of the collector exceeds a predetermined threshold.

Abstract: An apparatus for detecting defects in wood which includes an inlet for loading a piece of wood in the apparatus, a scanning device for scanning and detecting defects in the piece of wood and an outlet for releasing the piece of wood from the apparatus. The inlet and outlet are each provided with at least one roller assembly which include a top and bottom roller. The roller assemblies are positioned relative to each other and the scanning device so that the piece of wood is maintained, at any time, by two points.