Abstract: The present invention provides a printing member having a single radiation-absorptive multiphase layer over a substrate layer that may be imaged with or without ablation.

Abstract: A printing plate is clamped to a plate support by providing the plate support with a magnetic surface and laying a printing plate having opposite edges on that surface. Then, a first strip-like ferromagnetic blade clamp is deposited on the plate so that the first blade clamp is adjacent and parallel to one edge of the plate and a second strip-like ferromagnetic blade clamp is deposited on the plate so that the second blade clamp is adjacent and parallel to the opposite edge of the plate. The magnetic attraction of the blade clamp to the support surface enables the blade clamps to releasably clamp the printing plate to the support surface. Dispensing mechanisms for depositing the blade clamps on, and removing them from, the support surface are disclosed. The invention has particular application to releasably clamping superimposed donor and receptor sheets to the plate cylinder of proofing apparatus.

Abstract: In a digital imaging system including an array of imaging devices that apply an image to a recording medium such as a lithographic printing plate, elimination or reduction of longitudinal imaging artifacts is accomplished by blending the zones imaged by each the devices. In the course of a complete scan of the recording medium, the imaging devices each traverse a series of longitudinal columns of dot locations, and the devices are fired only at appropriate dot locations as determined by the digital image data. By operating adjacent imaging devices such that the zones they would ordinarily cover are blended in a random pattern, artifacts at the boundary between zones (such as seams) are hidden. While sufficient visual disruption to eliminate artifacts is ensured, noticeable visual artifacts are not created as a consequence of the disruption.

Abstract: Metal-based printing members suitable for transfer-type imaging include a metal substrate and a hydrophilic, polymeric coating thereover. Desirably, the polymeric coating is crosslinked and withstands repeated application of fountain solution during printing. The polymeric coating can, however, undergo degradation where exposed to fountain solution so long as the ink-receptive portions—the areas where oleophilic material has been transferred onto the hydrophilic coating—remain intact.

Abstract: Lithographic imaging using non-ablative printing members combines the benefits of simple construction, the ability to utilize traditional metal base supports, and amenability to imaging with low-power lasers that need not impart ablation-inducing energy levels. A representative printing member has a hydrophilic metal substrate and, thereover, first and second layers. The first layer has a thickness and an exposure surface and comprises a material that absorbs imaging radiation. The second layer overlies the first layer and is oleophilic and substantially transparent to imaging radiation. Exposure to imaging radiation causes the first layer and the substrate to irreversibly detach without substantial ablation, thereby facilitating removal, by subjection to the cleaning liquid, of the first and second layers where detachment has taken place.

Abstract: Lithographic imaging using non-ablative printing members combines the benefits of simple construction, the ability to utilize traditional metal base supports, and amenability to imaging with low-power lasers that need not impart ablation-inducing energy levels. A representative printing member has a topmost layer that is ink-receptive and does not significantly absorb imaging radiation, a second layer thereunder that is hydrophilic and does absorb imaging radiation, and a metal substrate under the second layer. The printing member is selectively exposed to laser radiation in an imagewise pattern, and laser energy passes substantially unabsorbed through the first layer and is absorbed by the second layer. Heat builds up in the second layer sufficiently to detach the first layer, which is formulated to resist reattachment. But the first layer and, more significantly, the third layer act to dissipate heat from the second layer to prevent its ablation.

Abstract: Provided is a lithographic printing plate comprising a support substrate having disposed thereon an ablative-absorbing layer and, optionally, a durable, ink-accepting surface layer that is not ablative-absorbing. The ablative-absorbing layer may contain a high weight per cent of an organic sulfonic acid component. The printing plate may further comprise a hydrophilic polymeric layer interposed between the ablative-absorbing layer and the substrate. The printing plate also comprises a primer layer underlying the ablative-absorbing layer with an adhesion-promoting agent, such as a zirconium compound, present in the primer layer. Also provided are methods of preparing such lithographic printing plates, and methods of preparing imaged lithographic printing plates from such lithographic printing plates by imagewise exposure to a laser and a subsequent cleaning step with water or with a cleaning solution.

Abstract: Cleaning compositions for ablation-type lithographic printing plates include solvent, non-solvent and lubricating components, the vapor pressures and concentrations of the various components being chosen such that the mixture never becomes too rich in solvent. In this way, the solvent's effect is directed primarily at thermal byproducts, which, because they are exposed and already partly decomposed, are more vulnerable to solvent action than the intact, anchored plate constituents in unimaged regions. The compositions are used in conjunction with mechanical rubbing of the plate surface following imaging.

Abstract: Lithographic printing is performed with printing members having a hydrophilic-surfaced metal support and a polymeric layer thereover. The polymeric layer absorbs imaging radiation and is soluble in a liquid to which ink will not adhere (e.g., fountain solution). Ordinarily, the polymeric layer is mostly removable by fountain solution. In response to absorbed imaging radiation, however, it may become permanently bound to the metal support so as to resist removal, serving as an ink-carrying oleophilic layer during printing.

Abstract: A linear array of diode laser emitters is manufactured with sufficient thermal and electronic isolation among the emitters to permit separate addressability. The emitter bar has first and second opposed surfaces and a third surface through which the emitters direct output. A first surface of the emitter bar is affixed to a “standoff” element that has conductive surfaces connecting each emitter to a power source; these connections are maintained after a series of spaces is formed between the emitters of the emitter bar. The second surface of the emitter bar is affixed to a heat sink to form a finished assembly.

Abstract: A plate material tensioning and advancement mechanism is disposed in parallel relation to a cylinder, such as a plate cylinder of a printing press, so as to separate the plate material into distinct printable sections. The plate material tensioning and advancement mechanism assists in supplying tension to the plate material via a tensioning roll during printing operation and assists in winding fresh plate material about the cylinder during advancement operation by reducing the tension on the plate material and by optionally applying tangential force to the plate material via a winding roll.

Abstract: The effects of interfacial transition between organic and inorganic layers of a lithographic printing member are ameliorated by incorporating an inorganic component within the matrix of the organic layer. In a first aspect, a lithographic printing plate having adjacent organic and inorganic layers is fabricated by depositing a curable polymer, softening the polymer, and integrating an inorganic material therewith. The polymer is then cured to immobilize the integrated deposition material, and the desired inorganic layer is applied over the deposited inorganic material (and any exposed portions of the polymer). In a second aspect, a graded structure is built up on a substrate in successive deposition steps. Both polymer precursors and an inorganic filler material are deposited in stages, with each stage containing a desired ratio of polymer to filler.

Abstract: Negative-working and positive-working lithographic plate constructions include a durable hydrophilic layer; a hard, inorganic, oleophilic layer; and a substrate, which may be metal. If a metal substrate is employed, an overlying layer provides sufficient thermal insulation to prevent substantial dissipation of heat—which is necessary to achieve ablation—into the substrate. In the case of oleophilic layers employed in negative-working embodiments, certain ceramic materials are suitable, and an intermediate tying layer may be used to anchor a hydrophilic ceramic layer to the oleophilic layer. In positive-working embodiments, the oleophilic layers may be refractory compounds doped with oleophilic material. An advantage to the latter embodiments is the ability to apply traditional means of correction following imaging.

Abstract: The effects of interfacial transition between organic and inorganic layers of a multilayer construction are ameliorated by incorporating an inorganic component within the matrix of the organic layer. In a first aspect, a construction having adjacent organic and inorganic layers is fabricated by depositing a curable polymer, softening the polymer, and integrating an inorganic material therewith. The polymer is then cured to immobilize the integrated deposition material, and the desired inorganic layer is applied over the deposited inorganic material (and any exposed portions of the polymer). In a second aspect, a graded structure is built up on a substrate in successive deposition steps. Both polymer precursors and an inorganic filler material are deposited in stages, with each stage containing a desired ratio of polymer to filler.

Abstract: A thermoplastic container or packaging material is given low oxygen permeability by coating with a crosslinked acrylate layer and a layer of oxygen barrier material deposited over the acrylate layer. Another acrylate layer may be deposited over the oxygen barrier. The oxygen barrier is selected from the group consisting of silicon oxide, aluminum oxide and metal. The acrylate layer may be formed from a photopolymerizable polyfunctional acrylate that is sufficiently low viscosity to be sprayed on the substrate or applied by dipping. Alternatively, the acrylate layer is a polymerization product of an acrylate monomer which is evaporated in a vacuum, condensed on the substrate and polymerized by irradiation by ultraviolet or an electron beam.

Abstract: A thermoplastic container or packaging material is given low oxygen permeability by coating with a cross-linked acrylate layer and a layer of oxygen barrier material deposited over the acrylate layer. Another acrylate layer may be deposited over the oxygen barrier. The oxygen barrier is selected from the group consisting of silicon oxide, aluminum oxide and metal. The acrylate layer may be formed from a photopolymerizable polyfunctional acrylate that is sufficiently low viscosity to be sprayed on the substrate or applied by dipping. Alternatively, the acrylate layer is a polymerization product of an acrylate monomer which is evaporated in a vacuum, condensed on the substrate and polymerized by irradiation by ultraviolet or an electron beam.

Abstract: A single laser crystal is driven with multiple pumping sources to obtain discrete, collimated outputs without substantial thermal crosstalk, so that the action of one pumping source does not adversely interfere with the action of another source driving the same crystal; that is, an imaging output emanating from one crystal region will neither defeat nor spuriously cause an imaging output in another region.

Abstract: A fixture containing a plurality of parallel optical fibers is aligned using a solder circuit that is itself mounted on the surface. The fixture is positioned on the circuit so as to be in contact with a quantity of solder. With the solder in the molten state, the fixture is aligned with respect to an element receiving light output from the optical fibers, and the alignment is secured by allowing the solder to solidify with the fixture immobilized.

Abstract: Individually addressable laser crystals are optically coupled to a single slab of an optical carrier that transmits substantially without distortion. The crystals are separate for thermomechanical isolation but may be closely spaced (generally on the order of 0.003 inch apart), and may originate as a single crystal cut into separate segments.