Abstract: A printing device that includes a platen for supporting an imaging member during a printing operation and at least one print head subassembly for direct thermal printing on the imaging member. The print head subassembly is configured to be movable independently of the platen for printing on a first surface of the imaging member in a first transport path and on a second surface of the imaging member in a second transport path. The printing device also includes at least one driving roller for driving the imaging member during the printing operation that is configured to drive the imaging member through a driving nip created by the driving roller with a substantially constant degree of wrap wherein the distance of transport of said imaging member for a given angular rotation of said driving roller is substantially the same for the first transport path and the second transport path.

Abstract: A printing device that includes a platen for supporting an imaging member during a printing operation and at least one print head subassembly for direct thermal printing on the imaging member. The print head subassembly is configured to be movable independently of the platen for printing on a first surface of the imaging member in a first transport path and on a second surface of the imaging member in a second transport path. The printing device also includes an element movable with said print head subassembly for ensuring that the wrap of the imaging member around the platen is substantially symmetrical about the print line such that the thermal heating elements of the thermal print head are substantially parallel to the surface of the imaging member when printing on each side of the imaging member.

Abstract: Method and apparatus for peeling a carrier web having a protective layer from a keeper sheet of image-bearing medium. The carrier web and the protective layer are peeled about a peel member as the keeper sheet moves over and is deformed by a constraining roller located at or downstream of the peel member putting the protective layer in tension. Preferably, at least one of the peel member or the constraining roller has a compliant material covering to facilitate separation of unused portions of the protective layer from edges of the keeper.

Abstract: The present invention discribes a rotatable print drum apparatus for supporting thereon a printable medium having leading and trailing edges. The print drum comprises a relieved support surface for supporting the print medium wherein the relieved surface is formed with a recessed surface and a plurality of ribs protruding from the recessed surface in order to minimize contact of the print medium with the support surface of the drum.

Abstract: The present invention relates generally to securing a sheet medium onto a support surface and, more particularly, to a print drum for supporting a flexible film sheet medium on a relieved support surface so as to desensitize to medium to the effects of debris contamination and air turbulence for allowing the sheet to be imprinted with consistent resolution.

Abstract: A printing system employs a rotating drum for carrying a photosensitive printing medium in the form of a discontinuous sheet, there being a clamp carried by the drum and rotating therewith for holding ends of the sheet to secure the sheet to the drum. The system includes a print head having a laser beam which is spatially and temporally modulated for gray-scale printing of individual pixels of an image. The head is scanned parallel to an axis of the drum. A servomechanism responsive to angular orientation of the drum produces a linear scan during rotation of the drum. An optical system within the head provides a common path through a common objective lens for both a write laser beam and for a focus laser beam of an automatic focusing apparatus which positions the objective lens rapidly by a dither motion to compensate for undulations in the surface of the print medium.

Abstract: A sheet clamping system for high speed rotatable drums is provided in which light-weight clamping bars, formed of relatively thin metal sheet stock, are configured and/or oriented for maximum resistance to deflection radially of the axis of drum rotation as well as positively secured in a sheet medium clamping position at axially spaced intervals along the length of the drum. The system further includes centrifugally actuated, axially extending rods positioned to underlie the operative portion of each clamping bar in a manner such that leading and trailing edges of a retained sheet are sandwiched between the rods and the clamping bars under a clamping force generally proportional to the square of drum rotational speeds.