A device detects multi-spectral imaging by using line scan elements. The device may include an illumination module and a detection module to detect light scattered from an object illuminated by the illumination module. The device may also include an array of light sources to produce light at a plurality of different wavelengths, and create a uniform line of illumination with each of the different wavelengths. The light detection may be applied to authenticate and validate documents, such as bank notes moving along a document conveyer.