Abstract: A screening output density corrector of an image processor corrects output densities of a plurality of types of dotted pattern data stored in a screening data storage upon printing. A dotted image data generator uses a plurality of types of the dotted pattern data subjected to the output density correction for performing screening processing to each of images, the images being represented by the continuous tone image data. Consequently, the dotted image data generator generates dotted image data of the images with the corrected output density. Accordingly, output density correction is made not to the continuous tone image data but to the dotted pattern data. Consequently, uniformity of the discharge characteristic (the number of ink droplets) is obtainable upon printing with different types of dotted pattern data. This allows prevention of unevenness in printing through the screening processing based on a plurality of types of dotted pattern data.

Abstract: Provided is a printing method of performing printing onto a recording medium to be transported with a plurality of recording element arrays. The printing method includes a storing step of storing a perimeter of a timing roller upon acquiring correction data in association with the correction data, an obtaining step of obtaining the perimeter during printing after the storing step of storing the perimeter upon acquiring the correction data, and a modifying step of modifying the correction data during the printing in accordance with the perimeter upon acquiring the correction data and the perimeter during the printing.

Abstract: A controller controls printing heads to print a page information mark with black ink to perform line flushing. The printing heads each have a plurality of inkjet nozzles for discharging ink being disposed in parallel in a width direction of web paper. Upon printing the mark, when an overlap region is present in which a mark printable region overlaps a line flushing region with ink other than the black ink, the controller performs control to decrease an ink discharge amount per unit area in the overlap region in the mark printable region to be smaller than that in the mark printable region except for the overlap region and the line flushing region. This causes a decreased total ink discharge amount in the overlap region.

Abstract: A screening output density corrector of an image processor corrects output densities of a plurality of types of dotted pattern data stored in a screening data storage upon printing. A dotted image data generator uses a plurality of types of the dotted pattern data subjected to the output density correction for performing screening processing to each of images, the images being represented by the continuous tone image data. Consequently, the dotted image data generator generates dotted image data of the images with the corrected output density. Accordingly, output density correction is made not to the continuous tone image data but to the dotted pattern data. Consequently, uniformity of the discharge characteristic (the number of ink droplets) is obtainable upon printing with different types of dotted pattern data. This allows prevention of unevenness in printing through the screening processing based on a plurality of types of dotted pattern data.

Abstract: Provided is an inkjet printing apparatus configured to perform printing by discharging ink droplets onto a print medium. The apparatus includes a printing head having a plurality of inkjet heads and configured to perform printing by discharging the ink droplets from the plurality of inkjet heads onto the print medium; a chart printing device configured to print a step-shift correcting chart with the printing head; a reading device configured to read the step-shift correcting chart printed on the print medium; a print medium-processed portion detecting device configured to detect a processed portion of the print medium; an uninfluenced step-shift correcting-chart generating device configured to generate an uninfluenced step-shift correcting chart; and a shift-amount calculating device configured to calculate a shift amount for correcting the step shift in accordance with the uninfluenced step-shift correcting chart.

Abstract: An inkjet printing apparatus includes a plurality of nozzles for discharging ink, a CIS (Contact Image Sensor) type scanner for reading, as image data, charts for correction printed in the ink discharged from the nozzles, light emitters for emitting light to the charts for correction, a scanner controller for causing the scanner to scan the charts for correction with a plurality of read conditions, a correction table creator for creating nozzle shading correction tables based on the image data read, and a shading corrector for carrying out shading correction for the nozzles based on the correction tables.

Abstract: A printing apparatus performing printing to a print medium includes a printer having at least two line heads with a plurality of recording modules; a scanner configured to scan an image printed with the printer to obtain a scanned image; a correcting-chart printing unit configured to print first and second correcting charts in first and second line head printing areas, respectively; a scanned image collecting unit configured to collect first and second scanned images; a correction-data calculating device configured to calculate correction data by determining a reference head difference from the first scanned image, determining an individual head difference from the second scanned image, summing up the reference head difference and the individual head difference to obtain a total, the reference head difference and the total being regarded as the correction data for the first and second line heads, respectively; and an adjusting device configured to adjust a timing.

Abstract: A printing apparatus performing printing to a print medium includes a printer having at least two line heads with a plurality of recording modules; a scanner configured to scan an image printed with the printer to obtain a scanned image; a correcting-chart printing unit configured to print first and second correcting charts in first and second line head printing areas, respectively; a scanned image collecting unit configured to collect first and second scanned images; a correction-data calculating device configured to calculate correction data by determining a reference head difference from the first scanned image, determining an individual head difference from the second scanned image, summing up the reference head difference and the individual head difference to obtain a total, the reference head difference and the total being regarded as the correction data for the first and second line heads, respectively; and an adjusting device configured to adjust a timing

Abstract: Provided is an inkjet printing apparatus configured to perform printing by discharging ink droplets onto a print medium. The apparatus includes a printing head having a plurality of inkjet heads and configured to perform printing by discharging the ink droplets from the plurality of inkjet heads onto the print medium; a chart printing device configured to print a step-shift correcting chart with the printing head; a reading device configured to read the step-shift correcting chart printed on the print medium; a print medium-processed portion detecting device configured to detect a processed portion of the print medium; an uninfluenced step-shift correcting-chart generating device configured to generate an uninfluenced step-shift correcting chart; and a shift-amount calculating device configured to calculate a shift amount for correcting the step shift in accordance with the uninfluenced step-shift correcting chart.

Abstract: An image forming apparatus for forming an appropriate test pattern is provided. A control section 41 includes: an image combination section 412 for combining image information corresponding to a subject image P1 of a first resolution, with second pattern information which corresponds to a test pattern P2 of a second resolution different from the first resolution, and which represents image information of the first resolution, so as to generate combined image information as one piece of image information; and an operation instruction section 413 for instructing a recording head 1, a head driving section 2, and a medium driving section 3 to form, on a recording medium, the combined image information corresponding to one piece of image information.

Abstract: An image forming apparatus for forming an appropriate test pattern is provided. A control section 41 includes: an image combination section 412 for combining image information corresponding to a subject image P1 of a first resolution, with second pattern information which corresponds to a test pattern P2 of a second resolution different from the first resolution, and which represents image information of the first resolution, so as to generate combined image information as one piece of image information; and an operation instruction section 413 for instructing a recording head 1, a head driving section 2, and a medium driving section 3 to form, on a recording medium, the combined image information corresponding to one piece of image information.