Abstract: A fountain solution for a lithographic press is treated by applying a succession of doses of electromagnetic radiation at increasing frequencies, from audio to radio frequencies, via an antenna that is immersed in the fountain solution. The conductive elements of the antenna are sealed within an insulating sheath so as to be out of contact with the fountain solution.

Abstract: An image forming apparatus comprises: an image forming body comprising a substrate and a self-assembling compound adsorbed to a surface of the substrate to form a self-assembling monomolecular film; a first desorbing device for selectively desorbing at least a part of the self-assembling compound forming the self-assembling monomolecular film from the surface of the image forming body, so as to provide the surface of the image forming body with a desorbed face and an undesorbed face which have wettabilities different from each other; a developing device for supplying the surface of the image forming body with ink which preferentially attaches to one of the desorbed face or undesorbed face; and a transfer device for transferring to a recording medium the ink attached to the surface of the image forming body. In this apparatus, a printing plate can easily be formed and erased, and the same printing plate can be used repeatedly.

Abstract: A wide format thermal printer for printing a multicolor graphic product on a printing sheet; a vacuum workbed for supporting a sheet material for performing work operations, such as cutting, printing or plotting, thereon; a replaceable donor sheet assembly, which includes a memory, for use with a thermal printer; methods and apparatus for improved thermal printing, including methods and apparatus for conserving donor sheet and reducing the amount of time required to print a multicolor graphic product; a thermal printhead including a memory; methods and apparatus for the alignment of a sheet material for printing or performing other work operations on the sheet material; and methods and apparatus for controlling the tension of the donor sheet during printing with a wide format thermal printer. The wide format thermal printer can include provision for the automatic loading of cassettes of donor sheet from a cassette storage rack.

Abstract: An apparatus and method for supplying emulsion ink to a printing plate on a printing press is disclosed. The apparatus includes an ink feed and recirculation system and associated control system to quickly and reliably form a high quality emulsion ink. The control system utilizes both feedback and feedforward control strategies. The recirculation of the emulsion ink ensures that the emulsion ink remains stable and makes it possible to reformulate the emulsion ink, if necessary, without waiting for the exhaustion of all of the emulsion ink that is in need of reformulation.

Abstract: A printing machine includes a printing form, an optical imaging unit for directly imaging the printing form, and an inking unit for inking the printing form, the printing form having a surface formed of a material with wetting properties reversibly changeable between a state with a very small contact angle and a state with a relatively large contact angle, the state with a small contact angle being achievable by action of light having a wavelength shorter than a material-specific wavelength, and a cleaning device for cleaning the surface of the printing form; and a printing process performed with the printing machine.

Abstract: A lithographic printing member comprises a base material and a coating provided thereon. The coating having one or more layers containing magnetic particles. Printing processes and products are also disclosed.

Abstract: A curing system for a photohardenable material is disclosed having an electrically powered light source and a variable power supply electrically connected to the light source. During calibration, a photocell determines the power output of the light source and produces an output signal representative thereof. A control circuit then controls the illumination of the light source by the power supply. This control circuit includes a comparator which compares the power output signal from the photocell with a target value and then varies or increases the power from the power supply to the light source up to a maximum power output whenever the power output signal from the photocell is less than the target value. Following calibration, the control circuit also activates the power supply for a time period sufficient to obtain a substantially constant energy output from the light source per light activation.

Abstract: A meterable screen roller having a peripheral surface whereon a multiplicity of printing ink-accepting depressions are disposed includes a respective base for the depressions formed by a resilient material, and respective chambers located underneath and assigned to the depressions, the chambers being actable upon by a pressure medium for respectively enlarging and reducing the volume of the depressions.

Abstract: According to the present invention there is provided an imaging element for making a lithographic printing plate, including on a first side of a flexible support a surface capable of being differentiated in oleophilic and oleophobic areas upon imaging and on a second side opposite to the first side a layer or a package of layers, characterized in that the layer or package of layers on the backside has a ratio of the squared value of the gravimetric water absorption (WA) in g/m2 over the mean roughness in &mgr;m greater than 20.

Abstract: In a device for engraving screen-based impression cylinders, particularly for intaglio printing, by means of an engraving element in an electronic engraving machine, an engraving element is controlled by an engraving signal which engraves a series of wells into the rotating impression cylinder line by line. The wells are arranged according to a screen defined by presettable engraving parameters, and their engraving depths represent the engraved tone values. To engrave the entire surface area of the wells, the engraving element moves in a feed motion along the impression cylinder in the direction of the axis of the impression cylinder. The screen geometry is determined by the peripheral speed of the rotating impression cylinder and the feed motion of the engraving element.

Abstract: A printing system which uses a single layer printing member coated on to a cylinder is provided. For waterless offset application, the single layer printing member consists of an oleophobic imaging layer containing an oleophobic resin, coated on an oleophillic cylinder. For wet application, the single layer may either be hydrophilic, coated on a oleophillic cylinder; or vice versa. The single layer printing member is composed of a resin having either oleophobic, hydrophilic or oleophillic properties, to which an infra red absorbing component or components may be added.

Abstract: A system and method for preventing a broken printing web from wrapping about or otherwise fouling the blanket cylinders of printing press units. The system and method includes a web tensioning device located downstream of the printing press units for maintaining tension upon a broken web and pulling the web from the printing press units. The device includes a plurality of web disturbance detectors for detecting a wave, ripple or other disturbance indicative of a web break. A pair of anti-wrap rollers located above and below the web are engaged upon detection of a web break to engage the web between them to exert tension onto the web and pull it from the printing units. The anti-wrap rollers are rotated at a surface speed nominally greater than the surface speed of the printing rolls. The anti-wrap rollers include a plurality of opposed peak and valley portions which enable them to interlock and grip the web along a line of contact.

Abstract: A stencil printing apparatus includes a main body, a drum unit having a drum substantially in a cylindrical shape and attachable to and detachable from the main body, a drum detecting device for detecting a kind of the drum unit mounted to the main body and a control device for carrying out an auto idling operation prior to a successive perforating operation in a case when a non-operational time period of the main body exceeds a previously set time period or when the drum detecting device detects interchanging of the drum unit.

Abstract: A printer includes a printer carrier having a surface for receiving ink for transfer printing onto a carrier material, such as paper. Areas of the surface print carrier are ink attracting and others are made ink repelling. The ink repelling areas are formed by providing the surface with a layer of a substance in a solid phase, such as water in the form of ice. The ice layer repels the ink as it is applied so that the ink is only held on the surface of the print carrier at the areas that are ice free. The ice layer is formed by cooling the surface using a cooling mechanism to form a coating of frost due to condensation. A surface tension reducer for water is coated on the surface prior to cooling the surface. A laser or other radiation emitter structures the ice layer to form the print image.

Abstract: There are provided a plate-making sheet and a printing device for printing on the plate-making sheet. The plate-making sheet is in the form of a strip and for being printed with stamp characters to be engraved on a stamping face of a stamp, in parallel with a process for making the stamp, for permitting checking of the stamp characters and for indication of the stamp characters on a back surface of the stamp. The plate-making sheet comprises a backing sheet, and an adhesive sheet laminated on the backing sheet and having a surface to be printed with the stamp characters. The surface of adhesive sheet is formed with a character check area to be printed with the stamp characters for permitting the checking of the stamp characters, and at least one indication character area to be printed with the stamp characters for the indication of the stamp characters. In the printing device, a printing mechanism prints stamp characters in a character check area and at least one indication character area.

Abstract: According to the present invention there is provided a lithographic base including a support and a hydrophilic cross-linked layer having a total volume of pores of more than 0.0007 cm3/g of the lithographic base. The hydrophilic cross-linked layer contains a hydrophilic binder, TiO2 particles and a low molecular weight polyhydric alcohol or a liquid amide as a drying control chemical additive.

Abstract: An improved hydrophilized substrate for planographic printing is disclosed. The substrate contains a support and a hydrophilic layer over the support. The hydrophilic layer contains titanium dioxide (titania) particles. In one embodiment, the hydrophilic layer contains a mixture of coated and uncoated titanium dioxide particles, and, optionally, alumina particles. A method for preparation of the substrate and a printing member comprising the substrate are also disclosed.

Abstract: A stencil printer operable with a master wrapped around a print drum includes a rotatable print drum. An ink roller is rotatable in the same direction as the print drum for feeding ink to the inner periphery of the drum. An ink replenishing roller is rotatable in the same direction as the print drum and ink roller and movable between a first position where it is spaced from the inner periphery of the drum and ink roller and a second position where it contacts the inner periphery of the drum and ink roller. An ink collecting member is located downstream of the ink replenishing roller in the direction of rotation of the print drum and movable in interlocked relation to the ink replenishing roller. The printer is capable of surely removing excess ink from the inner periphery of the print drum and desirably forming even the first image after a long time of suspension.

Abstract: A photoengraving machine comprised of a cabinet with a flash light mounted in an upper lever thereof facing down towards a fixture seat. The fixture seat is secured on a slide-in chassis in the cabinet. The fixture seat comprises an adjustable clamping assembly to securely hold different sizes of stamps. Consequently, a prefabricated stamp with a stamping face made of a black EVA sheet can be securely held on the fixture seat to be photoengraved in the cabinet under a flash lighting. Thus, the process of photoengraving for stamping face is simplified and the quality of the photoengraving is ensured by the photoengraving machine.

Abstract: An apparatus for preparing a screen printing screen is provided. It includes an exposing frame which houses a curing agent such as a light source. A reimagable image carrier is placed in registration with the exposing frame and is connected to a computer capable of supplying the image carrier with an image. An image may be created on the image carrier by exposing it to heat, UV light, or an electrostatic charge, or the image may be erased by exposing it to white light, heat, or a grounded object depending upon the image carrier material. A printing screen coated with an uncured stencil coating is placed above the image carrier. The image carrier will allow the curing agent to pass through those areas which are not blocked by the image supplied thereto to harden desired areas of the stencil coating on the printing screen, and uncured coating is rinsed away.