Abstract: The object of the present invention is to provide a picture color tone controlling apparatus and a picture color tone controlling method for a printing press wherein, also where different kinds of screening are used jointly to carry out printing, color tone control can be carried out with high accuracy.

Abstract: A method and a system for printing management, with the intension of appropriate color management performed in a newspaper print site in which a number of newspaper rotary presses of two or more types are provided, obtain image data representing each page edited in multilevel image data along with associated data concerning the page and makes a printing plate based on the image data and concurrently select a newspaper rotary press and a print material used for printing the page based on the multilevel image data and the associated data; perform color correction of the multilevel image data in accordance with the types of the selected rotary press and print material based on the color management data previously prepared, which multilevel image data is to be converted into binary image data and used for making a printing plate.

Abstract: In a picture color tone control method and apparatus for a printing press, in order to make it possible to use an IRGB densitometer to perform color tone control even when printing is performed with a density which exceeds an estimated maximum color space, a target color mixture halftone density for each ink supplying unit width when a printing picture is divided with an ink supplying unit width of ink supplying apparatus 6, 7 is set, and an actual color mixture halftone density for each ink supplying unit width of an actually printed sheet obtained by printing is measured using an IRGB densitometer 1. The color mixture halftone densities are individually converted into tone values. Thereupon, for the conversion into actual tone values, the publicly known Neugebauer expression wherein the Yule-Nielsen coefficient n is set to such a value that the tone values and the color mixture halftone density value have a substantially linear relationship to each other is used.

Abstract: A method and an apparatus for estimating ink strike-through aims at estimating ink strike-through occurs on a print sheet or web both side of which undergo printing. An apparatus for estimating ink strike-through includes a picture data obtaining section for obtaining a first picture data of a first picture to be printed on the first side and a second picture data of a second picture to be printed on the second side, a database for retaining a corresponding relationship between a difference between the first picture data and the second picture data and a density of strike-through of the ink; and an ink strike-through estimating section for estimating the possible strike-through on the basis of the first picture data and the second picture data obtained by the picture data obtaining section with reference to the database.

Abstract: The invention relates to picture color tone control for a printing press. A target color mixture halftone density for each ink supplying unit width when a printing picture is divided with an ink supplying unit width of ink supplying apparatus 6, 7 is set, and an actual color mixture halftone density for each ink supplying unit width of an actually printed sheet obtained by printing is measured using an IRGB densitometer 1. The color mixture halftone densities are individually converted into tone values. A changing ratio for the converted target tone values is set suitably and is reflected on the target tone values and then converted into a monochromatic halftone density. Then, a solid density difference corresponding to a difference between the target monochromatic halftone density and an actual monochromatic halftone density is determined, and the ink supplying amount is adjusted for each ink supplying unit width in response to the solid density difference.

Abstract: A method and a system for printing management, with the intension of appropriate color management performed in a newspaper print site in which a number of newspaper rotary presses of two or more types are provided, obtain image data representing each page edited in multilevel image data along with associated data concerning the page and makes a printing plate based on the image data and concurrently select a newspaper rotary press and a print material used for printing the page based on the multilevel image data and the associated data; perform color correction of the multilevel image data in accordance with the types of the selected rotary press and print material based on the color management data previosuluy prepared, which multilevel image data is to be converted into binary image data and used for making a printing plate.

Abstract: A picture color tone controlling method and apparatus for a printing press is disclosed by which a noticed pixel for control can be set appropriately and the accuracy in color tone control can be enhanced. For each of ink supplying unit widths, a region which has a high autocorrelation for each of the ink colors is selected in a sensor pixel unit of a densitometer, and a region obtained by removing an edge portion of the pertaining ink color having a width of a predetermined number of pixels from the selected region is set as a noticed pixel for each of the ink colors. Then, a target color mixture halftone density is set for each of the ink supplying unit widths, and an actual color mixture halftone density for each of the ink supplying unit widths of an actually printed sheet is measured using the densitometer. Further, the color mixture halftone density is converted into a halftone dot area ratio and further into a monochromatic halftone density.

Abstract: A picture color tone controlling method and apparatus for a printing press is disclosed which can readily and rapidly eliminate a positional displacement between a plate making image and an actual machine image and can appropriately perform color tone control in which an IRGB densitometer is used. A plate making picture position obtained from plate making data is moved so that a positional displacement between the plate making picture position and an actual picture position obtained from a result of actual printing. A target color mixture halftone density for each ink supplying unit width when a printing picture is divided with an ink supplying unit width of an ink supplying apparatus is set. An IRGB densitometer is used to measure the actual color mixture halftone density for each ink supplying unit width of an actually printed sheet obtained by printing. The color mixture halftone densities are individually converted into halftone dot area ratios and further into monochromatic halftone densities.

Abstract: A printing quality examining apparatus in which image data printing paper is successively taken in by a camera of a detection unit. The image data are compared with a previously taken-in reference data to detect a printing defect so that a decision as to whether printing quality is good or bad is made. The image data is averaged in time to calculate an estimated data, and the estimated data is compared with the previously taken-in reference data. When the estimated data is normal, pixels are determined to be normal. When the estimated data is unusual, the image data from the detection unit is compared with the reference data at next step so that when the image data from the detection is normal, the pixels are determined to be normal and when the image data is unusual, the pixels are determined to be defective and the paper is discharged.

Abstract: An apparatus for and a method of controlling a drag roller in a printing machine to move a web with no shift of a printing position and enhance the printing quality remarkably, even when the drag roller varies in diameter due to its temperature change. From a given temperature-rotational-speed table, a controlling unit obtains a rotational speed of the drag roller so as to adjust a circumferential speed of the drag roller, which speed corresponds to the current circumferential surface temperature checked by a temperature monitor unit. Then, a rotational speed changing unit changes the rotational speed of the drag roller to a value equivalent to the rotational speed obtained by the controlling unit.

Abstract: An apparatus for and a method of controlling a drag roller in a printing machine to move a web with no shift of a printing position and enhance the printing quality remarkably, even when the drag roller varies in diameter due to its temperature change. From a given temperature-rotational-speed table, a controlling unit obtains a rotational speed of the drag roller so as to adjust a circumferential speed of the drag roller, which speed corresponds to the current circumferential surface temperature checked by a temperature monitoring unit. Then, a rotational speed changing unit changes the rotational speed of the drag roller to a value equivalent to the rotational speed obtained by the controlling unit.

Abstract: Drag rollers disposed in a region from the paper feed side to the paper discharge side of a printing machine are driven one after another from the paper feed side with torque control, by which the slack of a web is removed successively from the upstream side of a web delivery running path.

Abstract: A printing quality examining method in which image data printing paper is successively taken in by a camera of a detection unit. The image data are compared with a previously taken-in reference data to detect a printing defect so that a decision as to whether printing quality is good or bad is made. The image data is averaged in time to calculate an estimated data, and the estimated data is compared with the previously taken-in reference data. When the estimated data is normal, pixels are determined to be normal. When the estimated data is unusual, the image data from the detection unit is compared with the reference data at next step so that when the image data from the detection is normal, the pixels are determined to be normal and when the image data is unusual, the pixels are determined to be defective and the paper is discharged.