Abstract: Apparatus and methods for imaging lithographic plates using laser devices that emit in the near-infrared region, and plates suitable for imaging with the apparatus and methods. Laser output either ablates one or more plate layers or physically transforms a surface layer, in either case resulting in an imagewise pattern of features on the plate. The image features exhibit an affinity for ink and/or a fluid to which ink will not adhere that differs from that of unexposed areas.

Abstract: Apparatus and methods for imaging lithographic plates using laser devices that emit in the near-infrared region, and plates suitable for imaging with the apparatus and methods. Laser output either ablates one or more plate layers or physically transforms a surface layer, in either case resulting in an imagewise pattern of features on the plate. The image features exhibit an affinity for ink or an ink-abhesive fluid that differs from that of unexposed areas.

Abstract: A system for accepting and winding lithographic plate material around a cylinder adapted for rotation about a longitudinal axis includes supply and uptake spools and an alignment tool for use therewith. The cylinder is hollow, having an interior and an axial opening thereto, and includes means within its interior for selectably engaging supply and uptake spools. The engagement means are in fixed alignment with one another and are disposed within the cylinder so as to define an unobstructed winding path extending around the cylinder from the supply spool to the uptake spool. Plate material stored on the supply spool is extended around this path and affixed to the uptake spool. The tool includes means for releasably gripping supply and uptake spools, and alignment components for aligning the gripping means to at least one engagement means within the cylinder when the tool is introduced therein. The tool is removed from the cylinder following release of the spools to the engagement means.

Abstract: Apparatus and methods for imaging lithographic plates using laser devices that emit in the near-infrared region, and plates suitable for imaging with the apparatus and methods. Laser output either ablates one or more plate layers or physically transforms a surface layer, in either case resulting in an imagewise pattern of features on the plate. The image features exhibit an affinity for ink or an ink-abhesive fluid that differs from that of unexposed areas.

Abstract: Apparatus and methods for imaging lithographic plates using laser devices that emit in the near-infrared region, and plates suitable for imaging with the apparatus and methods. Laser output either ablates one or more plate layers or physically transforms a surface layer, in either case resulting in an imagewise pattern of features on the plate. The image features exhibit an affinity for ink or an ink-abhesive fluid that differs from that of unexposed areas.

Abstract: Apparatus and methods for imaging lithographic plates using laser devices that emit in the near-infrared region, and plates suitable for imaging with the apparatus and methods. Laser output either ablates one or more plate layers or physically transforms a surface layer, in either case resulting in an imagewise pattern of features on the plate. The image features exhibit an affinity for ink or an ink-abhesive fluid that differs from that of unexposed areas.

Abstract: Apparatus and methods for imaging lithographic plates using laser devices that emit in the near-infrared region, and plates suitable for imaging with the apparatus and methods. Laser output either ablates one or more plate layers or physically transforms a surface layer, in either case resulting in an imagewise pattern of features on the plate. The image features exhibit an affinity for ink or an ink-abhesive fluid that differs from that of unexposed areas.

Abstract: A winding assembly especially suitable for use in conjunction with a system for automated imaging of lithographic plate material, including on-press imaging systems. A feeder spool installed within a plate-support cylinder contains a rolled supply of plate material, which wraps around the cylinder and is received by an uptake spool, also located within the cylinder. The assembly is driven by the same power source used to rotate the plate-support cylinder, and maintains a strong tension along the wrapped material.

Abstract: A method of and apparatus for imaging a lithographic plate having a printing surface by exposing the printing surface to plasma jet discharges between the plate and a plasma jet nozzle spaced close to the printing surface of the plate. These plasma jet discharges are sufficient to ablate or otherwise transform one or more layers of the printing surface, thereby changing the affinity of the printing surface for ink and/or water at the points thereof exposed to the discharges so as to produce image spots on the plate.

Abstract: Apparatus and method for imaging a lithographic plate having an oleophobic first layer, a metal second layer and an oleophilic third layer. The first and second layers are removed in an imagewise pattern to reveal the third layer, resulting in direct production of image spots. The plate is ready for printing at the conclusion of the imaging process.

Abstract: Apparatus and method for imaging a lithographic plate having a metal first layer and a second layer underlying the metal layer, the first and second layers exhibiting different affinities for fountain solution and/or ink. Selective removal of the first layer in an imagewise pattern reveals the second layer, resulting in direct production of image spots. The plate is ready for printing at the conclusion of the imaging process.

Abstract: Printing apparatus has at least one print station including a blanket cylinder in rolling contact with an impression cylinder, a print cylinder for supporting a lithographic plate, the plate cylinder being in rolling contact with the blanket cylinder, at least one discharge source for applying an image to a plate supported by the plate cylinder, and a motor for moving the energy source relative to the plate cylinder so that when the plate cylinder is rotated, the discharge source scans a raster on the surface of the plate supported by the plate cylinder. The apparatus may be configured as an in-line or central-impression type press. A controller responsive to picture signals representing an original document repeatedly actuates each discharge source momentarily during the scan thereof so that the discharge source forms on the plate surface an image comprised of dots corresponding to the original document.

Abstract: Apparatus for imaging a lithographic printing plate wherein structure is provided for removing debris generated by an imaging head and adhering to the plate. The debris removing structure may comprise a rotating brush which is selectively movable into and out of contact with the plate as necessary. Cleaning fluid may be delivered to the brush and suction may be used to aid removal of debris loosened by the brush.

Abstract: An imaging head for use in a spark-discharge recording apparatus, including a tracking system for monitoring and maintaining the head a fixed distance away from the surface of a recording blank. The tracking system preferably measures the distance between the head and the surface of the blank using a gas source oriented toward the blank's surface and a pressure sensor for measuring the pressure of the gas reflected therefrom. The signal produced by the pressure sensor indicates the size of the gap. The pressue sensor is coupled to a servo system that alters the position of the head to maintain a preselected gap distance.

Abstract: A pitch-and-roll adjustment mechanism for use in conjunction with a spark-discharge writing head. The mechanism provides structure for adjusting the physical position of the writing head with respect to a recording medium, and includes a flexure plate capable of flexing through a limited arc in two axes without permanent deformation.

Abstract: A method of imaging a lithographic plate having a printing surface comprises exposing the printing surface to plasma jet discharges between the plate and a plasma jet nozzle spaced close to the printing surface of the plate. These plasma jet discharges are sufficient to remove a layer or layers of the plate to thereby change the affinity of the printing surface for ink and/or water at the points thereof exposed to the discharges, thereby producing image spots on the plate.

Abstract: A low cost press able to print high quality continuous tone color copies comprises a single large diameter impression cylinder rotatably mounted to the machine frame. A plurality of print stations are spaced around the impression cylinder, each print station including a blanket cylinder in rolling contact with the impression cylinder and a plate cylinder in rolling contact with the blanket cylinder, the diameters of all of said plate and blanket cylinders being substantially the same and said impression cylinder having a diameter that is the same as or an even number more than the product of the plate cylinder diameter multiplied by the number of plate stations in the press. The cylinders are all rotatably coupled together by correspondingly sized gears so that they all rotate in unison with the impression cylinder gear being composed of arcuate parallel-cut segments having identical tooth profiles.