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:
A method of reducing printing artifacts in a printing apparatus including a plurality of printing plates, each of which is produced by successive scans of an array of imaging devices wherein the printing artifacts are caused by defective operation of one or more of the imaging devices. Printing artifacts are visually minimized by staggering the imaging devices used to produce separation plates. By staggering the imaging devices, the distance between artifacts can be reduced thereby causing the artifact reproduced in the final composite image to be less accentuated.
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:
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 diverter assembly for a conveyor system includes a carriage mounting a plurality of positively driven shafts. The shafts each support a plurality of wheels that engage articles traveling on the conveyor system. The wheels swivel between an aligned straight-through orientation and a skewed divert orientation. The swiveling motion is controlled by air cylinders associated with each shaft; the air cylinders being individually and selectively actuated. The carriage also has an associated air cylinder that elevates the carriage and the associated wheels to a raised position during the divert mode. The elevating mechanism and the swiveling mechanism are independently controlled and actuated. This arrangement provides a diverter assembly in which the diverter wheels are selectively raised and swiveled to positively and efficiently divert articles from the main line conveyor to a takeaway conveyor.
Abstract:
A printing member for a press without dampening made by forming on a metal substrate an organic plastic layer having an exposed surface which is highly oleophobic and thermally decomposing the layer surface at selected image points thereon without contacting the surface and without penetrating through the layer so that there is a transformation of the surface structure which renders said surface oleophilic at said image points.