Abstract: A manuscript picture is inputted at a picture input unit (10) as a set of pixels having a density value. On the plate, cells corresponding to inputted respective pixels are engraved by a stylus (32). The stylus is vibrated by a drive device (33) and is scanned on the plate by a scanning mechanism (31). Functions (A, B, C, D) for converting density values for respective pixels to cell width values indicating sizes of cells to be engraved are prepared. Thus, cell width values corresponding to density values provided at the picture input unit are generated. The stylus engraves cells corresponding to cell width values generated. The manuscript picture is dealt separately every a plurality of picture areas (A0, A1, A2). Conversions using different functions are applied to pixels within different picture areas. To the picture area of character/solid tone, new unique functions (B, D) are applied in order that a more distinct pictorial image is provided.

Abstract: An offset sheet-fed press is provided with a cleaning apparatus for an impression cylinder. The cleaning apparatus includes a cleaning unit which includes a frame member, a magazine roll provided with a spring brake for a cleaning cloth, a wind-up roll for winding up the cleaning cloth while stepwisely transferring the cleaning cloth by a wind-up torque motor, guide rolls for guiding the cleaning cloth so that the cleaning cloth faces the outer surface of the impression cylinder between the magazine roll and the wind-up roll, and a plurality of air cylinders arranged in parallel and disposed on the rear surface side of the cleaning cloth facing the impression cylinder. The cleaning unit further includes a cleaning cloth press assembly provided with a linear press blade linerally pressing the cleaning cloth against the impression cylinder on the side of the magazine roll, a plate-like guide disposed on the side of the wind-up roll and a surface press pad pressing the surface of the impression cylinder.

Abstract: A cleaning system for offset sheet-fed printing presses according to the present invention comprises a magazine roll for reeling-out cleaning cloth to perform the cleaning of the impression cylinder, a take-up roll to take-up this cleaning cloth, a blade provided between the magazine roll and the take-up roll and in contact with the impression cylinder from behind the rear side of the cleaning cloth, and a guide member to bring the cleaning cloth pressed by the blade, into contact around the arcuate circumferential surface of the impression cylinder and in contact along the axial length of the impression cylinder. This cleaning system for offset sheet-fed printing presses additionally comprises a pressing member provided between the blade and the guide portion so as to press the arc-shaped contact portion of the cleaning cloth against the impression cylinder and preferably comprises a blade being provided so as to be freely capable of advancing and retreating with respect to the cleaning cloth.

Abstract: A gravure printing system comprises at least one printing unit for printing a material fed from a supply side, a washing system for supplying a washing solvent to the printing unit and duct assemblies operatively connecting the printing unit and the washing system. The printing unit comprises unit frames located on both the sides of the printing unit, a plate cylinder supported by support shafts rotatably supported by the unit frames, an ink pan disposed movably to an upper operating position and a lower waiting position, a device for closing an upper opening of the ink pan in the operating position and the plate cylinder above the ink pan, a device operatively connected to the washing system for ejecting washing solvent to the plate cylinder, the plate cylinder support shafts, and the ink pan, a plate cylinder exchanging mechanism for conveying the plate cylinder out of the printing unit to exchange a used plate cylinder with a new plate cylinder.

Abstract: Apparatus particularly useful for the removal of iron particles and other magnetic solids from printing ink. Included is a casing (22) through which flows a liquid to be clarified. A plurality of straight bar magnets (M), mounted to the inside surface of a tubular sheath (50), are magnetically attached to the outer surface of the casing for creating magnetic fields within the casing. The magnetic solids contained in the liquid are magnetically attracted to the inside surface of the casing and so are separated from the liquid. The detachment of the magnets from the casing causes the separated solids to settle to the bottom of the casing for easy discharge through a drain port (38) formed therein. A cartridge filter (28) is provided centrally within the casing for the separation of nonmagnetic solids from the liquid.