Abstract: Pumped laser crystals for use in an imaging apparatus are designed and housed so as to minimize variation in dot size across the spectrum of duty cycles ranging generally from 1% to 100%--that is, from print densities ranging from every hundredth pixel to every consecutive pixel.

Abstract: A laser system for imaging graphic-arts constructions avoids the need to demagnify a divergent beam by using the output of a semiconductor or diode laser to optically pump a laser crystal, which itself emits laser radiation with substantially less beam divergence. A preferred implementation utilizes, as a pumping source, at least one laser device that emits in the IR, and preferably near-IR region, to image ablative or transfer-type printing members. The output of the pumping source is provided to the laser crystal via a focusing lens arrangement. The output of the laser crystal, in turn, is focused onto the surface of a recording medium to perform the imaging function.

Abstract: Laser guiding and focusing apparatus for imaging lithographic printing members responsive to the output of laser devices. Radiation passes through at least one discrete layer of a printing member and ablates one or more underlying layers, resulting in an imagewise pattern of features on the printing member. The radiation is obtained from a laser diode and its dispersion reduced to produce an image spot with maximum depth-of-focus tolerance.

Abstract: A focusing assembly includes features that allow numerical aperture to be reduced and optimized by reducing aberrations and ghost reflections and easily controlling stop size, thereby increasing depth-of-focus. The assembly includes a single, bi-aspheric focusing lens that optimizes image quality at a specific off-axis field point. Passage of excessively divergent radiation is prevented by a baffle having a sharp, flared edge that minimizes reflection. A second aperture or baffle can be included to restrict high-divergence radiation emerging from the bi-aspheric focusing lens. All interior surfaces of the focusing assembly are preferably blackened, once again to minimize internal reflections.

Abstract: A head tending apparatus for an ink jet printing system with at least one ink jet being disclosed. The apparatus includes a solvent supply system for spraying solvent on the faces of the ink jets and in the jet openings and a brush for scrubbing the ink jet faces during and immediately after the spraying process. Solvent vapors enter the jets and deprime the jets so that the ink remaining in the jets drains out of the jets back to the ink reservoir allowing solvent vapors to penetrate the jets to the reservoir. Resultantly, when the jets are next primed with ink, the jets are substantially free of air bubbles. Head tending is normally performed when the printer is shut down, or prior to the priming of the ink jets.

Abstract: A head tending apparatus for an ink jet printing system with at least one ink jet is disclosed. The apparatus includes a solvent supply system for spraying solvent on the faces of the ink jets and in the jet openings. The apparatus also has a brush for scrubbing the ink jet faces during and immediately after the spraying process. The solvent loosens and dissolves any solid matter that may have formed on the jet faces or in the jet openings and also deprimes any ink remaining in the jets when the printer is shut down; the brush cleans the loosened matter off the jet faces. If the printer has a rotating image insert assembly with the ink jets thereon, the brush and a solvent jet are mounted to a shell adjacent the ink jets. The brush includes a bristle-free section that is normally adjacent the image insert assembly and spaced away therefrom when the head tending appartaus is deactivated; this prevents the apparatus from interfering with the normal operation of the printer.

Abstract: An ink curing apparatus for use with an ink jet printer that discharges liquefied ink is disclosed. The apparatus includes a shell assembly disposed around the portion of the printer imaging assembly that includes the ink jets. The imaging assembly and the shell wall are shaped so that a first cavity is formed between the imaging assembly and the paper printed on, and a second cavity is formed between the paper and the shell wall. A pair of fans are arranged to draw air currents over both sides of the portion of the paper that is being printed on. The air currents cool the paper so the ink solidifies upon contact with the paper and does not soak through it. The air currents also insure that the ink solidifies at a uniform rate regardless where it is applied on the paper. This insures the final image on the paper has a uniform appearance.

Abstract: An ink jet priming system for an ink jet printer having a reservoir containing ink for ink jets connected thereto and a reservoir opening for receiving ink is described. The ink jet priming system is provided with a seal for selectively closing the reservoir opening. Pressurized air is supplied to the reservoir from a tank connected thereto through an opening in the seal. The flow of air to the reservoir is controlled so that there is an initial low pressure air flow to force ink into the jets followed by a high pressure flow to force the discharge of the streaming discharge of the ink. A gutter assembly, connected to a disposable waste container is provided for receiving and collecting the ink discharged during the priming process. The ink jet priming system can be used with a moving print head that contains two or more separate reservoirs each with a separate reservoir opening.