Abstract: A black-generation-and-UCR processing unit generates image data of a black ink color from image data of chromatic ink colors of the image and adjusts values of the image data of the chromatic ink colors correspondingly to generation of the image data of the black ink color. An image outputting unit causes a printing device to perform printing based on the image data. A print condition adjustment unit derives an ink coverage of the image on a print sheet, determines a black generation ratio corresponding to the ink coverage, and causes the black-generation-and-UCR processing unit to perform generation of the image data of the black ink color with the determined black generation ratio. The ink coverage indicates a ratio of ink usage amounts of the chromatic ink colors and the black ink color to a predetermined maximum value, for a pixel for which ink is ejected in the image.

Abstract: In an inkjet recording device, when a defective nozzle in a recording head is corrected, a control unit increases the amount of ink discharged to a correction pixel region adjacent to a defective pixel region corresponding to the defective nozzle in an intersection direction as compared with the amount of ink discharged to each of other pixel regions. The control unit reduces the amount of ink discharged to the correction pixel region by the recording head arranged on a downstream side in the direction of movement of a recording medium as compared with the amount of ink discharged to the correction pixel region by the recording head arranged on an upstream side in the direction of movement of the recording medium.

Abstract: In an image forming apparatus, a recording element group is configured to eject ink correspondingly to a driving voltage, and a density adjusting unit is configured to (a) cause to eject ink for a first test chart with a first driving voltage and causes to eject ink for a second test chart with a second driving voltage that is different from the first driving voltage, (b) acquire a density of the first test chart and a density of the second test chart, (c) derive a difference between the density of the first test chart and the density of the second test chart, and (d) derive a driving voltage corresponding to a target density on the basis of the difference between the density of the first test chart and the density of the second test chart and a difference between the first driving voltage and the second driving voltage.

Abstract: In the inkjet recording apparatus, for correction of a faulty nozzle of recording heads, the controller increases a quantity of ink ejection to corrective pixel areas adjacent in an intersectional direction to a faulty pixel area corresponding to the faulty nozzle to more extent than another quantity of ink ejection to other pixel areas. The controller decreases the quantity of ink ejection to the corrective pixel areas according as Oken type smoothness of the recording medium becomes higher and higher.

Abstract: In the inkjet recording apparatus, during execution of a correction mode, an image reading part reads a check chart for density measurement recorded on a sheet by a recording part, whereby a controller acquires density information about recording heads. The controller also repeatedly corrects a drive condition for the recording heads until the acquired density information about the recording heads comes to not more than a predetermined threshold value. When the drive condition for the recording heads has been corrected to a specified number of times, it is decided whether or not the density information about the recording heads has been converging toward a specified value each time the drive condition for the recording heads is corrected, where given that the density information about the recording heads has not been converging toward the specified value, the threshold value is changed.

Abstract: In the inkjet recording apparatus, for correction of a faulty nozzle of recording heads, the controller changes quantity of ink ejection to corrective pixel areas adjacent in an intersectional direction to a faulty pixel area corresponding to the faulty nozzle. A quantity of ink ejection to the corrective pixel areas involved in a case where ink drops have already been ejected to adjoining pixel areas oppositely adjacent to the faulty pixel area with the corrective pixel areas interposed therebetween in the intersectional direction is larger than a quantity of ink ejection to the corrective pixel areas involved in a case where ink drops have not yet been ejected to the adjoining pixel areas.

Abstract: An ink-ejection-malfunction-nozzle detecting unit sets nozzle groups such that each nozzle group includes nozzles with a first interval, prints a first test pattern that includes first bands (including thin lines) corresponding to the nozzle groups, sets nozzle subgroups such that each nozzle subgroup includes nozzles with a second interval in each of the nozzle groups, prints a second test pattern that includes second bands (including thin blank lines) corresponding to the nozzle subgroups such that a correction process is performed for adjacent pixels of the thin blank lines, detects a first band including density defect in a scanned image of the first test pattern, detects a second band not including density defect in a scanned image of the second test pattern, correspondingly to the detected first band, and detects an ink ejection malfunction nozzle on the basis of the thin blank line in the detected second band.

Abstract: An image forming apparatus includes a recording head, a control unit, and a correction processing unit. The recording head is configured to eject ink corresponding to an image to be printed, using nozzles. The control unit is configured to determine nozzles corresponding to the image to be printed, correspondingly to a position of a print sheet, and cause the recording head to eject ink from the nozzles. The correction processing unit is configured to perform for the image after gradation process a correction process corresponding to density anomaly that occurs due to an ejection order of the nozzles. Further, the correction processing unit performs the correction process for a density of a target pixel that the density anomaly occurs in the image after gradation pixel, on the basis of a total of densities of periphery pixels within a predetermined distance from the target pixel.

Abstract: An image forming apparatus includes a recording head, a control unit, an ejection malfunction nozzle detecting unit, and a correction processing unit. The recording head is configured to eject ink corresponding to an image to be printed, using arranged nozzles. The control unit is configured to determine nozzles corresponding to the image to be printed and cause the recording head to eject ink from the nozzles. The ejection malfunction nozzle detecting unit is configured to perform an ejection malfunction test and thereby detect an ejection malfunction nozzle among the nozzles. The correction processing unit is configured to perform a correction process corresponding to the detected ejection malfunction nozzle.

Abstract: A control unit causes a recording head to eject ink from nozzles corresponding to an image to be printed. An ejection malfunction nozzle detecting unit prints a test pattern using the recording head, and detects an ejection malfunction nozzle on the basis of a scanned image of the test pattern. The test pattern includes plural test pattern images such that in each of the plural test pattern images a dot is not formed at a dot position of a target nozzle set as a non ejection nozzle, and the target nozzles of the plural test pattern images are sequentially shifted by one nozzle in a primary scanning direction. Further, the ejection malfunction nozzle detecting unit determines an ejection malfunction nozzle on which ejection deviation occurs, on the basis of density decreasing amounts of respective density decrease parts in the plural test pattern images in the scanned image.

Abstract: A recording head ejects ink using nozzles. A control unit determines nozzles corresponding to an image to be printed and causes the recording head to eject ink from the nozzles. A correction processing unit detects an ejection malfunction nozzle and performs a correction process corresponding to the ejection malfunction nozzles. The correction processing unit causes a secondary adjacent nozzle of the ejection malfunction nozzle to perform ink ejection with a first ink ejection amount if ink ejection of a primary adjacent nozzle of ejection malfunction nozzle is performed earlier than ink ejection of the secondary adjacent nozzle and causes the secondary adjacent nozzle to perform ink ejection with a second ink ejection amount if ink ejection of the primary adjacent nozzle is performed later than ink ejection of the secondary adjacent nozzle. Here, the second ink ejection amount is smaller than the first ink ejection amount.

Abstract: An image forming apparatus includes a recording head, a control unit, and a correction processing unit. The recording head is configured to eject ink corresponding to an image to be printed, using arranged nozzles. The control unit is configured to determine nozzles corresponding to the image to be printed, correspondingly to a position of a print sheet, and cause the recording head to eject ink from the nozzles. The correction processing unit is configured to detect an ejection malfunction nozzle and perform a correction process corresponding to the ejection malfunction nozzles. Further, if the number of the detected ejection malfunction nozzles exceeds a predetermined upperlimit value, the correction processing unit preferentially sets as a target of the correction process an ejection malfunction nozzle that ejects an ink droplet earlier than nozzles corresponding to two adjacent dots of a dot corresponding to the ejection malfunction nozzle.

Abstract: An image forming apparatus includes a recording head, a control unit, an ejection malfunction detecting unit, and an ejection malfunction nozzle determining unit. The recording head ejects ink corresponding to an image to be printed, using arranged nozzles. The control unit determines nozzles corresponding to the image and causes the recording head to eject ink from the nozzles. The ejection malfunction detecting unit (a) prints a first test pattern on a print sheet using the recording head, and (b) detects a density defect due to ejection malfunction in a scanned image of the first test pattern. The ejection malfunction nozzle determining unit (a) prints a second test pattern using the recording head if the density defect is detected by the ejection malfunction detecting unit, and (b) does not perform printing of the second test pattern if no density defects are detected by the ejection malfunction detecting unit.

Abstract: An ejection malfunction nozzle detecting unit prints plural test patterns on a print sheet using a recording head, and detects ejection malfunction nozzles on the basis of scanned images of the plural test patterns. The plural test patterns are line-shaped or band-shaped images for which a correction process has been performed at plural nozzle positions with a predetermined period. The nozzle positions of the plural test patterns are specified with offset positions different from each other. Further, the ejection malfunction nozzle detecting unit (a) determines a test pattern that densities at periodical ejection malfunction positions have been corrected among the plural test patterns on the basis of density distributions of scanned image of the test patterns, and (b) stores as ejection malfunction nozzle data an offset position of the determined test pattern into a storage device.

Abstract: A black-generation-and-UCR processing unit generates image data of a black ink color from image data of chromatic ink colors of the image and adjusts values of the image data of the chromatic ink colors correspondingly to generation of the image data of the black ink color. An image outputting unit causes a printing device to perform printing based on the image data. A print condition adjustment unit derives an ink coverage of the image on a print sheet, determines a black generation ratio corresponding to the ink coverage, and causes the black-generation-and-UCR processing unit to perform generation of the image data of the black ink color with the determined black generation ratio. The ink coverage indicates a ratio of ink usage amounts of the chromatic ink colors and the black ink color to a predetermined maximum value, for a pixel for which ink is ejected in the image.

Abstract: An ejection malfunction nozzle detecting unit prints a test pattern on a print sheet using the recording head, and detects an ejection malfunction nozzle on the basis of a density distribution of a scanned image of the test pattern. Here, a resolution of the scanned image is lower than a resolution of the test pattern printed on the print sheet using the recording head. Further, a correction processing unit (a) stores into a predetermined storage device history data that indicates the ejection malfunction nozzle for which the correction process was performed, (b) refers to the history data and detects as an additional correction nozzle a nozzle included in the history data, among nozzles corresponding to a predetermined pixel range that includes a pixel corresponding to the detected ejection malfunction nozzle, and (c) performs the correction process for the detected ejection malfunction nozzle and the additional ejection malfunction nozzle.

Abstract: An ejection malfunction nozzle detecting unit prints a test pattern and detects ejection malfunction nozzles on the basis of a scanned image of the test pattern. The ejection malfunction nozzle detecting unit classifies the ejection malfunction nozzles into periodical nozzles that periodically appear with a specific period in a primary scanning direction and non-periodical nozzles other than the periodical nozzles; for the periodical nozzles, stores the specific period and an offset as the ejection malfunction nozzle data into a storage device, and for the non-periodical nozzles, stores the ejection malfunction nozzle data that individually indicates positions of the non-periodical nozzles into the storage device. A correction processing unit performs the correction process for the periodical nozzles on the basis of the specific period and the offset, and the correction process for the non-periodical nozzles on the basis of the positions of the non-periodical nozzles.

Abstract: An image forming apparatus includes a recording head, a controller, and a correction processor. The controller determines a nozzle corresponding to an image to be printed, and causes the recording head to eject ink from the nozzle. The correction processor detects an abnormally ejecting nozzle out of the nozzles in the recording head, and designates the abnormally ejecting nozzle as a target nozzle, and performs correction processing based on a status of the target nozzle, to the image. The correction processor also adds the detected abnormally ejecting nozzle to history data, each time a detecting operation is performed, and selects a nozzle included in the history data as an additional target nozzle, out of the nozzles that have not been detected as the abnormally ejecting nozzle, through the current detecting operation, and adds the selected nozzle to the target nozzle.

Abstract: An abnormal ejection detection portion detects an abnormal ejection nozzle in a print head based on a read test image read from a sheet with a test pattern formed thereon. When a plurality of abnormal ejection nozzles are detected and the plurality of abnormal ejection nozzles include two consecutive abnormal nozzles corresponding to two consecutive pixels in the read test image, a correction processing portion performs increase correction on an ink ejection amount of consecutive adjacent nozzles adjacent to the two consecutive abnormal nozzles and performs decrease correction on an ink ejection amount of secondary adjacent nozzles adjacent to the consecutive adjacent nozzles.

Abstract: An ink-ejection-malfunction-nozzle detecting unit sets nozzle groups such that each nozzle group includes nozzles with a first interval, prints a first test pattern that includes first bands (including thin lines) corresponding to the nozzle groups, sets nozzle subgroups such that each nozzle subgroup includes nozzles with a second interval in each of the nozzle groups, prints a second test pattern that includes second bands (including thin blank lines) corresponding to the nozzle subgroups such that a correction process is performed for adjacent pixels of the thin blank lines, detects a first band including density defect in a scanned image of the first test pattern, detects a second band not including density defect in a scanned image of the second test pattern, correspondingly to the detected first band, and detects an ink ejection malfunction nozzle on the basis of the thin blank line in the detected second band.