Abstract: A printing apparatus and a printing method are provided which, even if a print position misalignment occurs between a plurality of print scans during a multipass printing, can minimize density variations in a unit area reliably and stably, thus producing an image without density unevenness. For this purpose, multi-grayscale-level image data is converted into a plurality of dot arrangement patterns that determine individual subpixels either to be printed or not to be printed with a dot. Then, these dot arrangement patterns are printed overlappingly on a print medium in different print scans of the print head. At this time, the plurality of dot arrangement patterns are so arranged that, if these dot arrangement patterns are shifted from one another, a change in the dot-overlapping area ratio will be smaller than when the dots are arranged separately so that they do not overlap one another.

Abstract: While a conveying error of a roller depends on the eccentricity of the roller, the amount and the state of the eccentricity sometimes makes the roller have different conveying errors from one point in the longitudinal direction of the roller to another. There is provided a construction for obtaining a correction value that is suitable for the correction of the conveying error even in such a case as described above. To this end, plural test patterns are formed in the longitudinal direction of the roller. Then, a suitable correction value for correcting the conveying error that depends on the eccentricity of the roller is obtained on the basis of these test patterns.

Abstract: The present invention aims to obtain preferable correction values to correct the conveying error of a conveying roller in accordance with the size of a printing medium, even when the conveying error caused by the eccentricity of the roller varies from a point to another in the longitudinal direction of a roller, depending on the amount and the state of eccentricity of the roller. To achieve this object, correction values are acquired using the whole part of or only a part of plural test patterns formed in the longitudinal direction of the roller. The correction values thus acquired correspond to the respective zones where the test patterns are formed.

Abstract: While a conveying error of a roller depends on the eccentricity of the roller, the amount and the state of the eccentricity sometimes makes the roller have different conveying errors from one point in the longitudinal direction of the roller to another. There is provided a construction for obtaining a correction value that is suitable for the correction of the conveying error even in such a case as described above. To this end, plural test patterns are formed in the longitudinal direction of the roller. Then, a suitable correction value for correcting the conveying error that depends on the eccentricity of the roller is obtained on the basis of these test patterns.

Abstract: A printing apparatus comprises a conveyance belt configured to convey a printing medium while attracting the printing medium to a conveyance surface thereof using an electrostatic force, a printhead configured to discharge a printing material onto the printing medium conveyed by the conveyance belt, a blade configured to scrape the printing material adhering on the conveyance belt; a support unit configured to bring the blade into press contact with the conveyance belt, and a recovery unit configured to recover the printing material which is scraped by the blade and free-falls, wherein a pressure applied from the blade to the conveyance belt decreases from one end to the other end in an orthogonal direction perpendicular to a conveyance direction of the printing medium on the conveyance surface of the conveyance belt.

Abstract: In an inkjet printing apparatus, a printing medium is conveyed in a conveying direction by causing the printing medium to adsorb to the surface of the endless belt by electrostatic force. When print, the surface potential of the printing medium directly below the printing head is acquired. The discharge speed of the ink that has been associated in advance with the acquired surface potential is obtained, and an amount of variation in the landing position of the ink is determined based on the scanning speed of the printing head, the distance from the printing head to the printing medium, and the discharge speed of the ink. The timing of discharge of ink from the printing head is corrected to cancel out the determined amount of variation, and printing is performed based on image data in accordance with the corrected timing.

Abstract: While a conveying error of a roller depends on the eccentricity of the roller, the amount and the state of the eccentricity sometimes makes the roller have different conveying errors from one point in the longitudinal direction of the roller to another. There is provided a construction for obtaining a correction value that is suitable for the correction of the conveying error even in such a case as described above. To this end, plural test patterns are formed in the longitudinal direction of the roller. Then, a suitable correction value for correcting the conveying error that depends on the eccentricity of the roller is obtained on the basis of these test patterns.

Abstract: In an image processing method, on the basis of input image data with respect to a target pixel, independent multi-level data (g0, g1) corresponding to respective plural species of dots which are different in at least one of a density and a diameter are generated, and then data (O0, O1) relating to an amount of generation of the dots with respect to the target pixel are generated on the basis of a relationship between the generated independent multi-level data (g0, g1) corresponding to the plural species of dots. The image processing method is effective in performing design having a high degree of flexibility in proper use of a relatively high power dot (high density dot or large dot) and a relatively low power dot (low density dot or small dot) and can realize obviation or alleviation of an occurrence of granulation or an apparent frame caused due to the relatively high power dot.

Abstract: An image processing apparatus includes a first generation unit configured to generate N pieces of same color multi-valued image data, a second generation unit configured to generate N pieces of quantized data by performing quantization processing on the N pieces of same color multi-valued image data, and a third generation unit configured to divide at least one piece of the N pieces of quantized data into a plurality of quantized data and generate M pieces of quantized data corresponding to the M relative movements. The M pieces of quantized data includes quantized data corresponding to an edge portion of the recording element group and quantized data corresponding to a central portion of the recording element group, and a recording duty of the quantized data corresponding to the edge portion is set lower than a recording duty of the quantized data corresponding to the central portion.

Abstract: An object of this invention is to prevent prolongation of the time taken for a suction recovery operation while suppressing wasteful consumption of ink in the suction recovery operation. An ink-jet printing apparatus includes a plurality of caps which, when a plurality of nozzles of an ink-jet head are divided into a plurality of nozzle groups, are arranged one by one for the respective nozzle groups, and cap the respective nozzle groups, a suction pump which generates a negative pressure in the plurality of caps to suck ink from the plurality of nozzles, and is arranged commonly for the plurality of caps, and a control unit which controls the suction pump so as to make the negative pressure by the suction pump act on all the caps when a common negative pressure is generated in the plurality of caps, and make different negative pressures by the suction pump act sequentially on the plurality of caps when different negative pressures are generated in the respective caps.

Abstract: Provided are a printing apparatus and a conveying-error controlling method capable of printing a high-quality image by correction reflecting the conveying amount of a printing medium. A provided inkjet printing apparatus prints images by printing scans for actual printing and by conveying the printing medium with a roller orthogonally to the printing-scan direction. In each printing scan, the printing medium is scanned with a print head having an array of nozzles from which the ink is ejected. The print head moving direction differs from the arranging direction of the nozzles in the array. The apparatus includes a conveying controller to control the conveying of the printing medium on the basis of a correction value used to correct a conveying error of the roller. The conveying controller changes the correction value to be applied in accordance with the conveying amount of the printing medium between two scans with the print head.

Abstract: In an ink jet printing apparatus using many types of inks to execute bidirectional printing, if ejection opening rows for yellow, magenta, and cyan inks are symmetrically arranged, ejection opening rows for a black ink are arranged adjacent to the most inside ejection opening rows for the yellow ink. Thus, a difference in color between forward scanning and backward scanning is determined by a difference in coloring between the black ink and the yellow ink. In this case, a possible color drift attributed to bidirectional printing can be suppressed by selecting the inks so that the difference in coloring between the black ink and the yellow ink is smaller than that between the black ink and the other color inks.

Abstract: The invention provides a configuration capable of judging whether an ink jet head is exchanged or whether it is replaced, and changing an amount of recovery operation when the ink jet head is exchanged or replaced. Thus a recording apparatus capable of avoiding a defective ink supply in case the ink jet head is exchanged or replaced, and not wasting the ink by unnecessarily excessive recovery operation, can be provided.

Abstract: In an ink jet printing apparatus using many types of inks to execute bidirectional printing, if ejection opening rows for yellow, magenta, and cyan inks are symmetrically arranged, ejection opening rows for a black ink are arranged adjacent to the most inside ejection opening rows for the yellow ink. Thus, a difference in color between forward scanning and backward scanning is determined by a difference in coloring between the black ink and the yellow ink. In this case, a possible color drift attributed to bidirectional printing can be suppressed by selecting the inks so that the difference in coloring between the black ink and the yellow ink is smaller than that between the black ink and the other color inks.

Abstract: A plurality of ejection portions are divided into groups, each containing at least one ejection portion, so that the suction-based recovery operation can be performed for each group independently. Since the number of ejection portions contained in each group differs, if an ink flow resistance varies among the different groups, simultaneous suction-based recovery operations can be done by using a common suction pump, without having to sequentially perform the suction-based recovery operations under an optimum pump driving condition. For this purpose, inner diameters of a plurality of ink discharge tubes running from a plurality of cap units, which cap a plurality of print head units having different numbers of ejection portions, to the common pump are differentiated. This allows different flows to be produced in different ink discharge systems, thus generating desirable ink flows for individual ink supply systems.

Abstract: Performed is conveying-error correction in accordance with the kind and the number of rollers that are actually involved in the conveying of a printing medium. Each of the rollers that are potentially involved in the conveying of the printing medium has a unique amount of eccentricity, and may affect the quality of image to be printed in a peculiar manner. To address this problem, a surface of the printing medium is divided into areas according to the number and the combination of the rollers that are actually involved in the conveying. A pattern each is printed for each of the areas thus formed while the pattern enables the detection of the conveying error. A correction value to correct the conveying error is calculated using each of the patterns. The correction values thus obtained are reflected in the conveying of the printing medium.

Abstract: An ink jet recording apparatus capable of landing an ink drop on an exact position on a recording medium is provided. An ink jet recording apparatus performs recording on a recording medium A which has been subjected to application processing with a pretreatment liquid. The ink jet recording apparatus has an electrostatic belt which has a resistance layer formed on the surface thereof, and a power feed roller which imparts charges to the surface of the electrostatic belt. The recording head discharges ink to the surface of the recording medium when the back of the recording medium comes into contact with the surface of the electrostatic belt to which the charges have been imparted.

Abstract: There are provided an image processing method and an image processor which realize the processing of restricting image degradations such as “dot delay”, “banding” and “wind ripple” with a simpler circuit construction. Therefore, after the regular quantization processing is performed, in a pixel in a prohibition position the processing of limiting a predetermined quantized value to change into another quantized value is performed corresponding to the obtained quantized value and the position information of the pixel of interest. By doing this, even in the low level of the density value, it is possible to realize at a low cost the construction in which dots having different sizes are mixed for printing.

Abstract: A voltage pulse that keeps the ejection volume within a specified range is selected for a plurality of print element columns, based on the heater rank and ink temperature information that influences the ejection volume during ink ejection. At this time, the voltage pulse is controlled so that the voltage value of the pulse is equal for a plurality of print element columns at any ink temperature and varies according to the ink temperature. This control process enables pulses of the same voltage value to be applied at all times to a plurality of nozzle columns even if these nozzle columns in the print head have different heater ranks. As a result, the ejection volumes of all nozzle columns can be kept within a specified range with high precision over a wide range of base temperature, without requiring complicated circuit configurations.

Abstract: A conveyance mechanism includes a conveyance belt having a detection pattern containing a plurality of isolated patterns. The shape of the plurality of isolated patterns contained in the detection pattern, the size of a template area from which a template pattern is to be extracted, and the size of a seek area are associated with each other so that a part of the detection pattern contained in the template pattern extracted from first image data invariably serves as a unique pattern in the seek area of second image data.