Abstract: Skew compensation apparatus for compensating for skew of a multi-beam scanning source, comprises: delay commencement detector(s) for detecting the start of a beam scanner position, position detectors for detecting the position of the multiple beams at a predefined interval following the commencement, so that the position indicates skew of the respective beam, and compensating electronics for automatically inserting a compensation for the skew by altering a delay into a timing signal for switching the respective beam. The commencement detector can be an existing start of scan detector and the apparatus can be built into the writing head, particularly at the conjugate location to the focal plane or at the focal plane of a laser printer or the like to provide a self-calibrating printer.

Abstract: A method for detecting and correcting misregistration between a plurality of separations printed by a printing apparatus, comprising: producing a calibration print output on a substrate, the calibration print output including at least one calibration pattern, wherein the at least one calibration pattern translates horizontal misregistration into a detectable indicator of misregistration in a process direction; detecting misregistration; and, performing a fine adjustment of the horizontal position of at least one of the separations using the at least one calibration pattern.

Abstract: An imager comprising a photosensitive surface; a light source which produces at least one scaning light beam; a deflector, arranged to deflect the at least one scanning light beam onto the photosensitive surface; and a sensor which measures the orientation of the deflector. The imager also comprises a controller operative to determine a placement error of said at least one scanning beam on the photosensitive surface, responsive to the orientation measurement by the sensor; and an actuator, responsive to the displacement error, and arranged to change the direction of deflection of the at least one light beam by the deflector. The sensor is configured to measure the orientation of the deflector substantially at a null in a vibrational mode of the deflector.

Abstract: Skew compensation apparatus for compensating for skew of a multi-beam scanning source, comprises: delay commencement detector(s) for detecting the start of a beam scanner position, position detectors for detecting the position of the multiple beams at a predefined interval following the commencement, so that the position indicates skew of the respective beam, and compensating electronics for automatically inserting a compensation for the skew by altering a delay into a timing signal for switching the respective beam. The commencement detector can be an existing start of scan detector and the apparatus can be built into the writing head, particularly at the conjugate location to the focal plane or at the focal plane of a laser printer or the like to provide a self-calibrating printer.

Abstract: A method for designing a screen includes receiving screen information related to a picture element divided into a number of subunits of the picture element, and determining an amount of an ink to apply to a media at a location of the picture element in response to the information. The subunits of the picture element have a higher resolution than the resolution of a printing apparatus at which the printing element will be reproduced.

Abstract: A scanner for scanning a beam across a surface, such as a photosensitive surface or a document, the scanner comprising: a plurality of multi-faceted polygon disks, mounted for common rotation on an axis; a plurality of data modulated beams, wherein one of said beams is configured to impinge on the facets of one of the disks and be reflected therefrom toward the surface.