Abstract: 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.

Abstract: 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.

Abstract: Provided is an inkjet printing apparatus discharging ink droplets onto a print medium to be transported successively for forming an image. The apparatus includes a print unit discharging the ink droplets onto the print medium to form the image, a heating roller disposed downstream of the print unit and winding the print medium for drying, and a downstream skew correcting device disposed downstream of the print unit and upstream of the heating roller, and correcting skew of the print medium.

Abstract: 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.

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: 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.

Abstract: 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.

Abstract: 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.

Abstract: When one of first to third power supply circuits breaks down, a change-over switch performs switching of electrical connection such that drive voltage is allowed to be supplied from normal one of the first to third power supply circuits also to one of the inkjet heads connected to the breakdown power supply circuit. Consequently, the power supply circuits are partially sharable with a plurality of inkjet heads, causing no necessity of stopping the apparatus for replacing one breakdown power supply circuit. As a result, suppression in decrease of throughput of the apparatus is obtainable.

Abstract: 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 Bn in a first time period Ta until input of an immediate timing signal Ak+1 since input of a last timing signal Ak. 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 Bn.

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: 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.

Abstract: A print-data generating section generates print data in accordance with a high-resolution raster image generated by a high-resolution rasterizing processor. A low-resolution rasterizing processor generates a low-resolution raster image having lower resolution than that of the high-resolution raster image. An overcoating-data generating section generates coating data in accordance with the low-resolution raster image. Overcoating data is handled with low resolution, resulting in less processing time for overcoating than when the overcoating-data is handled with high resolution.

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: When one of first to third power supply circuits breaks down, a change-over switch performs switching of electrical connection such that drive voltage is allowed to be supplied from normal one of the first to third power supply circuits also to one of the inkjet heads connected to the breakdown power supply circuit. Consequently, the power supply circuits are partially sharable with a plurality of inkjet heads, causing no necessity of stopping the apparatus for replacing one breakdown power supply circuit. As a result, suppression in decrease of throughput of the apparatus is obtainable.

Abstract: A print-data generating section generates print data in accordance with a high-resolution raster image generated by a high-resolution rasterizing processor. A low-resolution rasterizing processor generates a low-resolution raster image having lower resolution than that of the high-resolution raster image. An overcoating-data generating section generates coating data in accordance with the low-resolution raster image. Overcoating data is handled with low resolution, resulting in less processing time for overcoating than when the overcoating-data is handled with high resolution.

Abstract: In an image recording apparatus using an inkjet mode, printing paper fed from a paper feeder 2 is supplied onto tables 1 movable by an endless transport mechanism of a table moving mechanism 5. After each table 1 is transferred from the endless transport mechanism to linear motor mechanisms 61 of the table moving mechanism 5, an image is recorded by an image recorder 3. Subsequently, the table 1 is transferred from the linear motor mechanisms 61 to the endless transport mechanism, and then the printing paper on the table 1 is discharged by a paper discharger 4.

Abstract: In an image recording apparatus using an inkjet mode, printing paper fed from a paper feeder 2 is supplied onto tables 1 movable by an endless transport mechanism of a table moving mechanism 5. After each table 1 is transferred from the endless transport mechanism to linear motor mechanisms 61 of the table moving mechanism 5, an image is recorded by an image recorder 3. Subsequently, the table 1 is transferred from the linear motor mechanisms 61 to the endless transport mechanism, and then the printing paper on the table 1 is discharged by a paper discharger 4.

Abstract: An ink feeding method for a printing machine includes a color density measuring step for measuring color density of prints at intervals of time, a variation coefficient computing step for computing a variation coefficient for varying the ink feeding rate based on the color density of prints and a target color density of prints, a color density gradient computing step for computing, based on the color density of prints, a color density gradient representing a rate of variation in the color density of prints occurring with an increase in the number of prints, an expected color density computing step for computing, based on the color density gradient, an expected color density of prints occurring after a predetermined number of prints are made, a determining step for determining whether the expected color density of prints occurring after the predetermined number of prints are made exceeds the target color density of prints, and a variation coefficient correcting step for correcting the variation coefficient whe

Abstract: A printing apparatus includes an image reader for reading an image on a printed paper sheet to obtain image data, and a controller for controlling the image reader to obtain image data about a color chart including solid patches once for every predetermined number of printed sheets or at every predetermined time interval which is inputted and set. The controller processes the image data to compute a printed density of each solid patch. Measurement data including the printed density are sequentially stored in a storage section in association with the number of printed sheets or time. The measurement data stored in the storage section may be displayed by a display section or outputted to a print section in the form of history data indicating measurement data transitions. Thus, the printing apparatus including a device for measuring printed sheets can perform history management on the measurement data for every predetermined number of printed sheets or at every predetermined time interval.