Screen Holdings Co., Ltd.

Ricoh Company, Ltd.

Dainippon Screen Mfg. Co., Ltd.

Dainippon Screen Mfg., Ltd.

Kunio Muraji

Kazuki Fukui

Takaharu Yamamoto

Seiya Nomura

Satoru Kiyohara

Osamu Morizono

Katsuyuki Hisaoka

Tomoyasu Okushima

Yuji Kurokawa

Kazuki Yamanaka

Kazuyuki Tanoue

Hiroaki Kishida

Keisuke Hirai

Toru Kawada

Mitsuhiro Yoshida

Shoji Kakimoto

Hiroyuki Fuchioka

Asuka Muramatsu

Tomotaka Kato

Takahiro Uda

Akira Murata

Takashi Kamigiku

Yoshiyuki Nishigaito

Ippei Matsumoto

Hiroaki Kamon

Masaharu Nakagawa

Yoshikazu Koyanagi

An image shifter creates plural pairs of shift image data. A shading corrector and a halftone dot processor create halftone shift image data from shift images. Further, a difference image creator creates halftone common image data which is a common part of a pair of halftone shift image data, and creates halftone positive difference image data and halftone negative difference image data each of which is a difference between the halftone common image data and one of a pair of halftone shift image data. A composite image creator synthesizes the halftone common image data corresponding to an amount of positional deviation, and the halftone positive difference image data or halftone negative difference image data. A controller executes printing on web paper. Since the image data is only synthesized, processing load can be lightened even if printing is performed to restrain positional deviations.

Printing apparatus that restrains positional deviation and a printing method using the same

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:

Head voltage correcting method for inkjet printing apparatus, and an apparatus using same

An image processing apparatus for a printing apparatus. The image processing apparatus includes a recording position acquiring device for acquiring recording positions of a reference image printed by a reference print head and a target image printed by a target print head, a positional deviation amount calculating device for calculating a deviation amount due to a skew with respect to the recording positions of the reference image and the target image, and a positional deviation interpolation image converting device, when there is a remainder of the deviation amount and the predetermined intervals, for adding a weight based on the remainder, and adding a smaller weight than the weight to the reference image or the target image without a remainder and adjoining the reference image or the target image with the remainder, thereby converting the image into a width direction positional deviation interpolation image.

Image processing apparatus and image processing method for a printing apparatus

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.

Correction value acquiring method for inkjet printing apparatus, and an inkjet printing apparatus

Image data is accurately resized in real time by downscaling. An image signal generating apparatus includes a parameter generator that dynamically generates a parameter PM and an image signal generator that repeats processing of generating an output image signal Q in response to each sampling signal B. Each parameter includes a division ratio parameter DP. The division ratio parameter DP corresponds to a ratio of a second time period Tb and a third time period Tc other than the second time period Tb. The second time period Tb is a time interval until the generation of a sampling signal Bin a first time period Ta until input of an immediate timing signal Asince input of a last timing signal A. The image signal generator repeatedly generates a first weighted signal and a second weighted signal of the image signal in response to each sampling signal B.

Image signal generating apparatus, image inspection apparatus, printing system, and image signal generating method

A drive circuit for driving a plurality of nozzles to discharge ink droplets. The testing chart comprises a contrast chart including a first line segment group having first line segments formed by causing the drive circuit to output a reference drive signal for a density serving as reference, thereby to make discharge from a first number of driven nozzles, the first line segments extending in a direction perpendicular to a transport direction and arranged at predetermined intervals, and a second line segment group having second line segments formed by causing the drive circuit to output a drive signal for driving only a selected number of nozzles as target of correction less than the first number of driven nozzles, the second line segments being formed between the first line segments while changing the correction values for correcting the drive signal of the drive circuit.

Testing chart, a correction value acquiring method for an inkjet printing apparatus, and an inkjet printing apparatus

Disclosed is an inspecting chart including a reference pattern containing a first line segment group and a second line segment group, a first-side deviation pattern, and a second-side deviation pattern. The first line segment group is formed by a plurality of first line segments printed by a reference printing head at a first given interval. The second line segment is formed by second line segments printed by a printing head on a center between two adjacent first line segments or a center of each of the first line segments, the printing head being spaced away from the reference printing head in the transportation direction of a print medium. The first-side deviation pattern and the second-side deviation pattern are printed with various deviations.

Inspecting chart and printing apparatus

An image processor of a printing apparatus including a first printing head having recording units spaced at a given interval orthogonal to a transportation direction of a print medium and spaced along the transportation direction of the print medium, a second printing head disposed downstream of the first printing head, a device for obtaining recording positions of first and second images printed with the first and second printing heads, a device for calculating a positional shift amount between the recording positions of the first and second images, and a positional shift interpolating image converter performing weighting, if a remainder is generated through division of the positional shift amount by the given interval, to the first or second image depending on the remainder to convert the first or second image into a positional shift interpolating image having been shifted in accordance with skew of the print medium.

Image processor of printing apparatus and image processing method thereof

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.

Printing apparatus for modifying the print timing of recording element arrays according to the perimeter length of a timing roller

Disclosed is a printing apparatus that performs printing onto a print medium including a transporting device that transports a print medium, a plurality of printing heads, a photographing unit that photographs the print medium, a shift detecting chart forming device, and a correcting device. The shift detecting chart forming device forms a shift detecting chart having a first line segment group consisting of first line segments that are printed onto the print medium at given intervals in an orthogonal direction with respect to the transportation direction with a reference printing head, and a second line segment group formed along the first line segment group, and consisting of second line segments that are printed with a subsequent printing head. The correcting device corrects a printing timing with the subsequent printing head relative to the reference printing head in accordance with a density variation of the photographed shift detecting chart.

Printing apparatus

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.

Image processor and image processing method

Disclosed is an inkjet printing apparatus with an inkjet printing unit performing printing onto web paper to be transported. The apparatus includes a drive roller transporting the web paper, a transportation velocity detector detecting a transportation velocity of the web paper, an encoder generating a timing reference signal of the printing by the printing unit in accordance with transportation of the web paper, the encoder being disposed in a transport roller, a printing correction data generator generating printing correction data in accordance with the transportation velocity and the timing reference signal so as to correspond to a time-dependent variation of the transport roller provided with the encoder; and an offset corrector correcting the printing of the inkjet printing unit to the web paper in accordance with the printing correction data.

Printing apparatus and method for color-correcting printing on recording medium

Disclosed is an inspecting chart including a reference pattern containing a first line segment group and a second line segment group, a first-side deviation pattern, and a second-side deviation pattern. The first line segment group is formed by a plurality of first line segments printed by a reference printing head at a first given interval. The second line segment is formed by second line segments printed by a printing head on a center between two adjacent first line segments or a center of each of the first line segments, the printing head being spaced away from the reference printing head in a the transportation direction of a print medium. The first-side deviation pattern and the second-side deviation pattern are printed with various deviations.

In printing apparatus, an edge sensor detects a serpentine amount caused by transportation of a web. A predicted waveform data generating unit generates predicted waveform data on the serpentine amount to be produced in the following web in accordance with actually measured waveform data on the detected serpentine amount. A correcting unit corrects a printing position of an image in accordance with a shift amount, and applies a corrected printing position to a printing head. Here, the shift amount is determined with the shift amount determining unit in accordance with the predicted waveform data. Accordingly, the shift amount is determinable in accordance with the actually measured waveform data on the serpentine amount detected with the edge sensor more accurately than that through a method in which a shift amount is directly determined. This allows suppressed misregister.

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Kyoto, Japan

Kunio Muraji