Abstract: Multi-mode laser radiation is focused to a preselected spot size on a recording construction using a controlled-angle diffuser. The diffuser concentrates the radiation, counteracting the dispersive effects of multi-mode output.

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: 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 contains a high weight percent 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 may also comprise a primer layer underlying the ablative-absorbing layer with an adhesion-promoting agent 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: Provided are methods of imaging a wet positive working lithographic printing member comprising the steps of providing a positive working printing member comprising a substrate, a hydrophilic layer, an infrared-absorbing layer, and, optionally, an ink-accepting surface layer; exposing the printing member to infrared radiation in an imagewise pattern removing by ablation greater than 10% by weight, and most preferably none of the infrared-absorbing layer and optional ink-accepting surface layer; and removing with water the laser-exposed areas of the infrared-absorbing layer and optional ink-accepting surface layer to reveal the underlying hydrophilic layer. These methods are advantageous in reducing airborne debris and vapors during laser imaging, in increasing the speed of laser imaging, and in providing excellent cleanability and image quality. The printing member may further comprise a primer layer underlying the infrared-absorbing layer with an adhesion-promoting agent present in the primer layer.

Abstract: Provided is a positive working, wet lithographic printing member comprising a hydrophilic metal substrate having disposed thereon a hydrophilic layer, an ablative-absorbing, ink-accepting surface layer and, optionally, an ink-accepting overcoat layer that is not ablative-absorbing. 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 to remove residual laser-induced debris and damaged areas from the hydrophilic layer.

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 percent 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: Imaging of lithographic printing plates with reduced fluence requirements is accomplished using printing members that have a solid substrate, gas-producing and radiation-absorptive layers over the substrate, and a topmost layer that contrasts with the substrate in terms of lithographic affinity. Exposure of the radiation-absorptive layer to laser light causes this layer to become intensely hot. This, in turn, activates the gas-producing layer, causing rapid evolution and expansion of gaseous decomposition products. The gases stretch the overlying topmost layer to create a bubble over the exposure region, where the imaging layers have been destroyed. If this process is sufficiently explosive, the neck of the bubble expands beyond the diameter of the incident laser beam, tearing the topmost layer and the underlying imaging layers away from the substrate outside the exposed region.

Abstract: Methods and apparatus for lithographic imaging without ablation function by irreversibly debonding intermediate printing-plate layers, thereby rendering at least the surface layer removable by cleaning to expose, in an imagewise pattern, an underlying layer having a different affinity for ink and/or an abhesive fluid for ink. In contrast to ablation-type systems, it is unnecessary to destroy a plate layer, thereby reducing power requirements and facilitating increased imaging speeds.

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: Lithographic printing members have protective layers formulated specifically for use with single-fluid inks, and which are removed from the printing member during the preparatory procedures that precede printing. The protective layer provides protection against handling and environmental damage, and also extends plate shelf life; performs a cleaning function, entraining debris and carrying it away as the layer itself is removed; acts as a debris-management barrier if the layer immediately beneath the protective layer is ablated during the imaging process, preventing the emergence of airborne debris that might interfere with unimaged areas and/or imaging optics; and exhibits hydrophilicity, actually accelerating plate roll-up.

Abstract: Optimization of distances between each of an array of imaging devices and the surface of an oppositely disposed rotating drum is accomplished without disturbing the mechanical mounting of the imaging devices. For each device, an optimal distance from the recording construction is established; at this optimal distance, corresponding to substantially proper focus, maximum energy density is delivered to a recording medium on the drum. Rather than alter the actual device-to-drum distance to conform to this optimum, the optical paths between the devices and the drum are changed by varying the spacing between the radiation source (e.g., the end of a fiber-optic cable) and the assembly. This alters the point of focus, and therefore has the same practical effect as moving the device itself. The invention also provides a technique for determining the optimal device-to-drum distance by means of a sequence of imaged regions applied at different device-to-drum distances.

Abstract: Dimensional inconsistencies between a proof and an image to be overlaid thereon is avoided by subjecting both the proof image and the overlay image to the same heat treatment, thereby ensuring that both images undergo the same degree of shrinkage.

Abstract: Lithographic printing members have inorganic protective layers that may be applied by vacuum deposition. In a representative construction, a substrate and a first layer thereover have different affinities for ink and/or a liquid to which ink will not adhere; the first layer may, for example, be applied under vacuum and comprise a metal or a metallic inorganic layer. Onto this layer is deposited a material comprising, for example, a boron ceramic, and under conditions ensuring that oxygen is present at least at the interface between the boron ceramic and the first layer. The first layer may incorporate a surface layer of oxygen or may be an oxygen compound. The oxygen facilitates hydrolysis of the boron ceramic during the print "make-ready" process.

Abstract: Lithographic printing members utilize, as an ink-accepting layer, a hard, inorganic, and generally covalent material that exhibits sufficient flexibility (at the deposition thicknesses envisioned) to accommodate flexing and bending. This layer may overlie a relatively heavy, metal plate substrate or support, resulting in a structure whose permanent layers all share the physical properties of inorganic materials. The printing member may also be provided with a protective layer that serves a variety of beneficial functions, including protection against handling and environmental damage and extension of plate shelf life, but which also is removed during the printing make-ready process.

Abstract: Compensation for the effects of duty cycle on the output level of an imaging device, and for the effects of periodically varying distance between the output of the imaging device and its target, is accomplished electronically. An exemplary apparatus includes a source of radiation (generally a laser) having an output level that varies both with an input power level and, undesirably, with the duty cycle. The radiation source is operated to produce, on the recording surface, an imagewise pattern of spots, and an adjustment facility compensates for output-level variations resulting from duty cycle--that is, from the recent pattern of laser activity.

Abstract: Defects of electrostatic origin in lithographic printing plates are prevented by reducing or minimizing the dielectric nature of the various plate layers. This lessens the capacitance of the system, reducing the voltage that results from a given deposited charge and, consequently, the likelihood of arcing. This may be accomplished by utilizing, for the substrate of the plate, a conductive film.

Abstract: Constructions useful as lithographic printing plates include metallic inorganic layers exhibiting both hydrophilicity and substantial durability at very thin application levels. These materials ablatively absorb imaging radiation, thereby facilitating direct imaging without chemical development. They can also be used to form optical interference structures which, in addition to providing color, likewise absorb imaging radiation and ablate in response to imaging pulses.

Abstract: Lithographic printing is accomplished using wet lithographic printing plates that include a protective layer providing protection against handling and environmental damage, extension of plate shelf life, and entrainment of debris generated by ablation. The layer washes away during the printing make-ready process, effectively cleaning the plate and disappearing without the need for a separate removal process.

Abstract: Multiple winding mechanisms are disposed within a single cylinder, such as the plate cylinder of a printing press, and are actuable so as to pay out material across different cylinder segments. For example, the winding mechanisms may be differentially geared to cylinder rotation, such that rotation of the cylinder in a first direction advances material from a first winding mechanism across a first circumferential portion of the cylinder to a second winding mechanism; while rotation of the cylinder in the opposite direction advances material from the second winding mechanism across a second circumferential portion of the cylinder (which may, for example, be diametrically opposed to the first cylinder portion) to the first winding mechanism. Alternatively, material advancement may be achieved by means of a dedicated motor rather than mechanical coupling to cylinder rotation.

Abstract: Lithographic printing constructions are removable from a permanent support, which may be a metal sheet affixable (usually by clamps) to a plate cylinder, or may instead be the permanent surface of such a cylinder. In this way, the traditional "plate" is replaced with a thin, easily manufactured printing member, which is separated from the support following its use.