Abstract: A printing system is provided with a dummy data insertion unit configured to insert dummy data into print data based on waiting time occurring when post-processing is performed by a post-processing device (for example, a collating machine). In a printing unit, a dummy page is printed on the basis of the dummy data. A dummy page removing unit configured to remove a dummy page from printed printing paper so that the dummy page is not supplied to the post-processing device is provided between the printing device and the post-processing device.

Abstract: A printing system, including a printing apparatus that sends a print paper after printing to a post-processing machine and a web buffer that temporarily holds a print paper after printing, is provided with: a required print time calculation unit that calculates a required print time for each job; an increase and decrease amount calculation unit that calculates an increase and decrease amount of a consumption amount of the buffer per set for each job on the basis of a difference between a minimum processing time required for a process in a post-processing machine and the required print time; a predicted value calculation unit that obtains a predicted value of the consumption amount of the web buffer by accumulating increase and decrease amounts; and a conveyance control unit that controls a conveyance speed of print paper on the basis of the predicted value.

Abstract: A printing apparatus includes a head part, an encoder, a tension sensor, a head part temperature sensor, an edge sensor, an estimation part, a storage, and an output part. The estimation part estimates print quality in terms of a page printed by the head part on the basis of variation elements detected by the encoder, the tension sensor, the head part temperature sensor, and the edge sensor. The storage stores print quality information containing the printed page and the print quality estimated by the estimation part in association with each other. The output part outputs the print quality information to a display, a post-processing device, and a printer controller section.

Abstract: A printing apparatus of this invention scans with a tester a testing chart printed by a printing controller to acquire testing image data. A total amount of displacement calculator calculates an amount of displacement of a recording position including a direction of misregister as a total amount of displacement, based on a large amount of displacement determined by a large amount of displacement determiner, a direction of displacement detected by a direction of displacement detector, a shift amount corresponding to an amount of displacement detecting chart determined by an amount of displacement detecting chart determiner, and a peak position of the amount of displacement detecting chart determined by the amount of displacement detecting chart determining unit. Thus, since a total amount of displacement of the misregister can be calculated only by printing the testing chart on web paper WP, an amount of displacement of the misregister in the transport direction can be obtained easily in a short time.

Abstract: A head voltage correcting method for inkjet printing apparatus which perform printing with a head having a plurality of head modules includes the following steps: a testing chart printing step for printing testing charts which includes a lowest density head module check pattern, satellite check patterns, band-by-band density variable patterns, and in-band density variable patterns; a lowest density head module determining step for determining a lowest density head module; a satellite-free drive voltage determining step; and a new reference voltage determining step for determining a drive voltage of the band-by-band density variable patterns of the adjacent head module to be a new reference voltage for the adjacent head module.

Abstract: A head voltage correcting method for inkjet printing apparatus which perform printing by dispensing ink droplets from a head to a printing medium. The method includes the following steps: a step of printing testing charts; a step of acquiring images of the testing charts; a step of determining presence or absence of satellite droplets for each drive voltage; a step of obtaining distances between the main droplets and the satellite droplets for each drive voltage; a step of obtaining a distance reference drive voltage from a relationship of the distances for each drive voltage and a distance threshold; a step of obtaining ink droplet sizes for each drive voltage; a step of obtaining a size reference drive voltage; and a step of comparing the distance reference drive voltage and the size reference drive voltage, and making correction by adopting a larger one as the reference voltage.

Abstract: A head voltage correcting method for inkjet printing apparatus which perform printing with a head having a plurality of head modules includes the following steps: a testing chart printing step for printing testing charts which includes a lowest density head module check pattern, satellite check patterns, band-by-band density variable patterns, and in-band density variable patterns; a lowest density head module determining step for determining a lowest density head module; a satellite-free drive voltage determining step; and a new reference voltage determining step for determining a drive voltage of the band-by-band density variable patterns of the adjacent head module to be a new reference voltage for the adjacent head module.

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 head voltage correcting method for inkjet printing apparatus which perform printing by dispensing ink droplets from a head to a printing medium. The method includes the following steps: a step of printing testing charts; a step of acquiring images of the testing charts; a step of determining presence or absence of satellite droplets for each drive voltage; a step of obtaining distances between the main droplets and the satellite droplets for each drive voltage; a step of obtaining a distance reference drive voltage from a relationship of the distances for each drive voltage and a distance threshold; a step of obtaining ink droplet sizes for each drive voltage; a step of obtaining a size reference drive voltage; and a step of comparing the distance reference drive voltage and the size reference drive voltage, and making correction by adopting a larger one as the reference voltage.

Abstract: A correction value acquiring method for inkjet printing apparatus includes the following steps: a testing chart forming step for forming a testing chart in one printing job, the testing chart including a first line segment group having a plurality of first line segments formed by causing a drive circuit of a head module acting as reference to output a reference drive signal for obtaining a reference density, and a second line segment group having a plurality of second line segments formed by causing drive circuits of head modules other than the head module acting as reference to output the reference drive signal and drive signals with a plurality of different correction values added to the reference drive signal; an identifying step for identifying from the testing chart a second line segment having a density matching with that of a first line segment; and a correction value acquiring step for acquiring a correction value corresponding to the second line segment identified.

Abstract: A correction value acquiring method for inkjet printing apparatus includes the following steps: a testing chart forming step for forming a testing chart in one printing job, the testing chart including a first line segment group having a plurality of first line segments formed by causing a drive circuit of a head module acting as reference to output a reference drive signal for obtaining a reference density, and a second line segment group having a plurality of second line segments formed by causing drive circuits of head modules other than the head module acting as reference to output the reference drive signal and drive signals with a plurality of different correction values added to the reference drive signal; an identifying step for identifying from the testing chart a second line segment having a density matching with that of a first line segment; and a correction value acquiring step for acquiring a correction value corresponding to the second line segment identified.

Abstract: A printing apparatus of this invention scans with a tester a testing chart printed by a printing controller to acquire testing image data. A total amount of displacement calculator calculates an amount of displacement of a recording position including a direction of misregister as a total amount of displacement, based on a large amount of displacement determined by a large amount of displacement determiner, a direction of displacement detected by a direction of displacement detector, a shift amount corresponding to an amount of displacement detecting chart determined by an amount of displacement detecting chart determiner, and a peak position of the amount of displacement detecting chart determined by the amount of displacement detecting chart determining unit. Thus, since a total amount of displacement of the misregister can be calculated only by printing the testing chart on web paper WP, an amount of displacement of the misregister in the transport direction can be obtained easily in a short time.

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 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: 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 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.