Abstract: The printer comprises:a digital printing station (12);a support (20) for a roll (22) of the substrate web (24) carrying a plurality of synchronisation marks;means (28) for continuously feeding the substrate web (24) from the roll (22) past the printing station (12);a sensing device (32) positioned upstream of the printing station (12) for sensing the synchronisation marks on the web (24); andcontrol means (38) for initiating a printing sequence at the printing station (12) in response to the sensing of each of the synchronisation marks (26, 34, 36). Thereby a plurality of images are printed on the web (24), each at a predetermined location in the transport direction relative to an associated one of the synchronisation marks (26, 34, 36).

Abstract: A non-impact printer is described for forming an image on a medium. The printer having:a linear array of recording sources for forming a multi-gradation latent image on a receptor surface, the linear array comprising a plurality of sub-sets of recording sources;an element for developing the latent image into a visual image;an element for transferring said visual image onto the medium;an element for generating and storing first correction factors derived from measurements of the non-uniformity of average energy output of each of the sub-sets of recording sources;first correction element for applying, for each sub-set of recording sources, the first correction factors;an element for generating and storing second correction factors derived from measurements of the non-uniformity of each individual one of the recording sources; andsecond correction element for applying said second correction factors after applying the first correction factors.