In the present invention, copyrights of digital data in a database system including real time transmission of a digital picture are controlled. The LED elements are arranged in the form of an array and mounted on a bottom face of a straight groove defined in the printed circuit board by a groove forming technique. A device for processing a sheet material comprises the measuring device. The bottom panel member is coated on its upper surface with a foamed or an unfoamed low density polyethylene or foamed or unfoamed modified low density polyethylene. The printing system further includes a first forward generally horizontal interface media transport between the at least two image marking engines and the at least one feeder module for transporting media from the at least one media feeder module to at least one of the at least two image marking engines. A loop back optical fiber incorporated in at least one of the first and second optical paths, adds propagation delay length greater than the coherence length of the polarized input optical beam, giving rise to delayed and undelayed optical beam components, which are then incoherently recombined into a depolarized output optical beam.