A system for preparing a photopolymer printing plate includes an imager, a plate unloader configured to automatically unload the plate from the imager and deliver the plate to an exposure unit comprising a plurality of UV LEDs, and a controller configured to operate the imager, the plate unloader, and the exposure unit. The imager has a rotatable drum configured to rotate while laser beams ablate portions of an ablatable layer of the printing plate in accordance with imaging data. The UV LEDs include a back array and a front array configured to expose the front of the UV-curable plate, at least one of which is configured to emit UV radiation toward the plate during relative motion between the plate and the array.

A method for writing an imageable material using multiple beams includes preparing subsequent patterns each having Y rows of N pixel locations, said subsequent patterns including first and second patterns; where the first and the second pattern overlap with each other in an overlap area consisting of O columns and Y rows of pixel locations; selecting for each row i of said first pattern Mi1 pixel locations; selecting for each row i of said second pattern Mi2 pixel locations; writing simultaneously, for each row i, said Mi1 selected pixel locations by moving the N beams in a fast scan direction relative to said imageable material; and moving said N beams relative to said imageable material in a slow scan direction over (N−O) pixel locations; writing simultaneously, for each row i, said Mi2 selected pixel locations by moving the N beams in a fast scan direction relative to said imageable material.

A photosensitive resin structure for a flexographic printing plate, containing (a): a support; (b): a photosensitive resin composition layer which is located on the support (a) and which contains a thermoplastic elastomer having a copolymer site of a monovinyl-substituted aromatic hydrocarbon and a conjugated diene; and (c): an infrared ray ablation layer which is laminated on the photosensitive resin composition layer (b) and which comprises a resin and carbon black, is ablatable with an infrared laser, and is a layer shielding a light beam other than infrared ray, wherein the resin in the infrared ray ablation layer (c) contains a copolymer of a monovinyl-substituted aromatic hydrocarbon and a conjugated diene, or a hydrogenated copolymer of a monovinyl-substituted aromatic hydrocarbon and a conjugated diene, and a primary particle diameter of the carbon black contained in the infrared ray ablation layer (c) is 13 nm or larger and 25 nm or smaller.

A formative surface having a conductive base covered with a dielectric and oleophobic/hydrophobic surface layer is created with defined pits to grow micro-puddles of a defined volume. The formative surface is brought into close proximity with a charge retentive surface carrying a charge image. Fountain solution vapor nucleates and grows preferentially on the base of the pits as micro-puddle droplets. The puddles are charged and extracted from the surface to provide a fog of charged droplets of narrow volume and charge distribution. The charged droplets are attracted and repelled respectively from the charged and discharged image regions of the charge retentive surface, thus developing the charged image into a fountain solution latent image. The developed latent image is then brought into contact with a transfer member blanket and split, thus creating on the blanket a fountain solution latent image ready for inking.

Ink-based digital printing systems useful for ink printing include a secondary roller having a rotatable reimageable surface layer configured to receive fountain solution. The fountain solution layer is patterned on the secondary roller and then partially transferred to an imaging blanket, where the fountain solution image is inked. The resulting ink image may be transferred to a print substrate. To achieve a very high-resolution (e.g., 1200-dpi, over 900-dpi) print with these secondary roller configurations, an equivalent very high-resolution fountain solution image needs to be transferred from the secondary roller onto the imaging blanket. To increase the resolution of the image on the secondary roller, examples include a textured surface layer added to the secondary roller for contact angle pinning the fountain solution on the roll. Approaches to introduce a micro-structure onto the surface layer of the secondary roller, and also superoleophobic surface coatings are described.

Based on evaporation of fountain solution from a rotating blanket cylinder to create an image that may be inked and printed, a digitally addressable heater array at or just below the blanket surface evaporates deposited fountain solution and forms a fountain solution latent image on the surface. The heater array has controllable heating elements (e.g., field effect transistors, thin film transistors) that provide a transient heat pattern on the surface to evaporate the fountain solution. Heat is generated by current flow in the heating elements, and power developed by the heating circuit is the product of source-drain voltage and current in the channel. Current may be supplied along data lines by an external voltage controlled by digital electronics to provide the desired heat at heating elements addressed by a specific gate line. The heater array may include a current return line that may be a 2-dimensional mesh.

Fountain solution latent images are provided on an inking blanket without using laser-induced evaporation systems. Approaches include a rotatable charge retentive surface configured to receive an unfused toned electrostatic pattern of toner particles adhered thereto via electrophotography. The toner includes small diameter polymeric or inorganic particles that may have no color pigment to appear transparent or translucent. Fountain solution is disposed on at least one of the toner, the charge retentive surface and a transfer substrate. The transfer substrate is adjacent the charge retentive surface and forms a nip therebetween, with the transfer substrate sandwiching the unfused toned electrostatic pattern of toner particles and fountain solution against the charge retentive surface at the nip. Fountain solution sandwiched between the surfaces splits as the surfaces separate downstream the nip, leaving a fountain solution latent image remaining on the transfer member surface based on the electrostatic charged pattern on the charge retentive surface.

A heating circuit having an array of switching heating elements (e.g., field effect transistors, thin film transistors) provides a transient heat pattern over a surface (e.g., substrate, imaging member surface, transfer roll surface) moving relative to the heating circuit, to produce a pixelated heat image and heat a target pattern on the surface. Heat is generated by current flow in the heating elements, and the power developed by the heating circuit is the product of source-drain voltage and current in the channel. Digital addressing may accomplished by matrix addressing the array. Current may be supplied along data address lines by an external voltage controlled by digital electronics understood by a skilled artisan to provide the desired heat at a respective heating element pixels addressed by a specific gate line. The circuit may include a current return line that may be low resistance, for example, by using a 2-dimensional mesh.

According to aspects of the embodiments, there is provided a method of measuring the amount of fountain solution employed in a digital offset lithography printing system. Fountain solution thickness is measured by using phase shifted monochromic light to produce optical path differences through the fountain solution film. The intensity of the reflected light through the fountain solution film is very sensitive due to the phase shifted light so interference fringes are easier to delineate and fountain solution thickness measurement more reliable.

A method of lithographic plate making is disclosed wherein a plate precursor is exposed to laser radiation in the wavelength range from 350 to 450 nm, said plate precursor comprising a hydrophilic support and a photopolymerizable or photocrosslinkable image recording layer, and then processed on-press by supplying fountain and ink. The exposure produces a visible image having a 1976 CIELAB color distance ΔE between exposed and non-exposed areas of at least 2.5.