Abstract: An image forming apparatus includes: a nozzle head in which nozzles that ejects ink is arranged in a first direction; a moving mechanism that moves a recording medium relative to the nozzle head; an image acquirer that acquires image data; a quantization processor that quantizes density of pixels forming an image based on the image data; a grouping processor that groups adjacent pixel positions into one group in the quantized data; and a rearrangement processor that rearranges a quantized pixel value at each pixel position in the group that is grouped, wherein the grouping processor groups such that a direction intersecting the first direction is set to a second direction, arrangement of groups in the first direction is set to a row, rows is arranged in the second direction, and a row in which an initial position of the row is different at least by one pixel is included.

Abstract: An image forming apparatus includes: a nozzle head in which nozzles that ejects ink is arranged in a first direction; a moving mechanism that moves a recording medium relative to the nozzle head; an image acquirer that acquires image data; a quantization processor that quantizes density of pixels forming an image based on the image data; a grouping processor that groups adjacent pixel positions into one group in the quantized data; and a rearrangement processor that rearranges a quantized pixel value at each pixel position in the group that is grouped, wherein the grouping processor groups such that a direction intersecting the first direction is set to a second direction, arrangement of groups in the first direction is set to a row, rows is arranged in the second direction, and a row in which an initial position of the row is different at least by one pixel is included.

Abstract: An inkjet recording device including: a recorder; a mover; and a hardware processor, wherein a pair of recording heads having recording elements in overlapping arrangement ranges in a width direction are at positions different in one movement direction orthogonal to the width direction, ink changes the phase to a solid in a time shorter than a difference between times when the ink adheres to a same position in the one movement direction, the hardware processor performs recording control of causing a selected recording element to perform an output operation to each position in the one movement direction and determines an execution order of output operations such that the output operation by each of downstream-side recording elements is performed twice or more continuously and at least a part of the output operations by upstream-side recording elements is not continuous.

Abstract: An inkjet recording apparatus includes: a recorder having a line head, the recorder ejecting ink through each of the ink ejection ports toward a recording medium; a mover that moves the recording medium and the line head relative to each other in a direction intersecting the arrangement direction of the ink ejection ports in the line head, and causes each pair of ink ejection ports of two adjacent head modules facing each other in the overlapping region to pass through a same place on the recording medium; and a recording controller that controls ink ejection operations of the plurality of head modules on the recording medium in accordance with dot data, and causes either of a pair of ink ejection ports of two adjacent head modules to eject ink to implement complementary ink ejection operations by the pair of ink ejection ports of the two head modules.

Abstract: The present invention has a problem of suppressing liquid gathering of an interpolation dot which interpolates a discharge defective nozzle and preventing deterioration of image quality, and the problem is solved by the present invention including: an inkjet head configured to separately discharge a large droplet, a medium droplet, and a small droplet from each of a plurality of nozzles; and a control unit which forms an image in a single-pass system by discharging the medium droplets from the plurality of nozzles respectively, and forms an interpolation dot to interpolate a discharge defective nozzle by discharging a droplet from a different nozzle when the discharge defective nozzle is present, the control unit forming the interpolation dot to interpolate the discharge defective nozzle with the use of the large droplet and forming at least one adjacent dot which is in contact with the interpolation dot with the use of the small droplet.

Abstract: An image forming apparatus includes: an image former that includes ink dischargers of two or more colors and that forms an image on a recording medium; and a hardware processor that generates, in each of the ink dischargers, at least a first dot pattern of a first color with uniform density and a second dot pattern in a second color with uniform density. When the first dot pattern is combined with the second dot pattern, the hardware processor adjusts the second dot pattern based on a positional relationship of each dot in the first dot pattern.

Abstract: An inkjet recording device includes: an image former; an image reader including a line sensor and an optical unit; and a conveyor. The line sensor has imaging elements, and detects incident light from a surface of a recording medium over an imaging range corresponding to arrangement of the imaging elements in a width direction intersecting a relative movement direction in which the recording medium and/or the image reader is relatively moved, thereby performing one-dimensional imaging along the width direction. The optical unit removes a high-frequency-side component that is a spatial structure equal to or higher than a predetermined cutoff frequency from spatial distribution of the incident light from the imaging range and guides the incident light to the line sensor. The cutoff frequency for the high-frequency-side component is determined to be lower in the width direction than the relative movement direction.

Abstract: An ink jet recording apparatus includes an ink discharger provided with a plurality of nozzles which discharge ink; and a processor. The processor discharges ink onto a recording medium from the plurality of nozzles of the ink discharger, and uses the ink discharger to record on the recording medium a composite test image including a halftone image with a predetermined density and a defective nozzle specifying image which specifies a defective nozzle in which a defect in ink discharge is occurring. The processor obtains information regarding the defect in the ink discharge from the nozzle based on a density distribution of the halftone image read from read data of the composite test image and specifies a defective nozzle based on the above information and a portion in the defective nozzle specifying image of the read data.

Abstract: An inkjet recording apparatus includes: a recorder having a line head, the recorder ejecting ink through each of the ink ejection ports toward a recording medium; a mover that moves the recording medium and the line head relative to each other in a direction intersecting the arrangement direction of the ink ejection ports in the line head, and causes each pair of ink ejection ports of two adjacent head modules facing each other in the overlapping region to pass through a same place on the recording medium and a recording controller that controls ink ejection operations of the plurality of head modules on the recording medium in accordance with dot data, and causes either of a pair of ink ejection ports of two adjacent head modules to eject ink to implement complementary ink ejection operations by the pair of ink ejection ports of the two head modules.

Abstract: Disclosed is an image detection device for detecting a detection target image that is recorded on a recording medium by an ink droplet, including: an imaging unit that captures a surface of the recording medium; and a detector that detects a position of the detection target image. The imaging unit includes: a line sensor with a plurality of imaging elements; and an optical element that guides incident light to the line sensor. The optical element diffuses the incident light such that incident light emitted from the ink droplet width of less than twice an arrangement pitch in the predetermined direction of the plurality of imaging pixels is guided to an area on the plurality of imaging elements of greater than twice the element arrangement pitch in the predetermined direction. The detector detects the position based on detection values of the imaging pixels corresponding to the imaging elements.

Abstract: An image forming apparatus includes: a nozzle head in which nozzles that form dots on a recording medium by ejecting ink onto the recording medium are arranged in a row in a first direction; a moving mechanism that moves at least one of the recording medium or the nozzle head relative to another in a second direction intersecting the first direction; an image acquirer that acquires image data for forming an image of dots on the recording medium; and a halftone processor that determines whether to form a dot at each pixel position of the image on the basis of the image data, wherein the halftone processor includes: an n-value processor; a grouping processor; a total value calculator; and a rearrangement processor.

Abstract: An image recording device includes a recorder, a reader and a hardware processor. The recorder records an image on a recording medium. The reader reads, with an imaging element, a surface of the recording medium and a surface of a predetermined reference member. The hardware processor calibrates the reader for a value to be detected by the imaging element, based on a reading result of the reading of the surface of the reference member. Further, the hardware processor performs the calibration in at least one of: a case where a type of the image to be recorded on the recording medium satisfies a predetermined image type condition; and a case where a predetermined reading influence factor which affects a reading result of the reading of the surface of the recording medium satisfies a predetermined reading influence factor condition.

Abstract: An image forming device includes: a hardware processor that performs halftone processing on input image data using a threshold matrix of a dither method, and that, when dot missing exists in a formed image by the image forming part, performs interpolation by rearranging a missing dot to peripheral pixel position; and an image forming part that forms an image on a recording medium on the basis of image data after halftone processing by the halftone processing part, wherein the hardware processor, using the threshold matrix, sets a blank pixel having a high probability of being generated next when gradation is increased, as a rearrangement destination of the missing dot.

Abstract: An inkjet recording device including: a recorder; a mover; and a hardware processor, wherein a pair of recording heads having recording elements in overlapping arrangement ranges in a width direction are at positions different in one movement direction orthogonal to the width direction, ink changes the phase to a solid in a time shorter than a difference between times when the ink adheres to a same position in the one movement direction, the hardware processor performs recording control of causing a selected recording element to perform an output operation to each position in the one movement direction and determines an execution order of output operations such that the output operation by each of downstream-side recording elements is performed twice or more continuously and at least a part of the output operations by upstream-side recording elements is not continuous.

Abstract: An ink jet recording apparatus includes an ink discharger provided with a plurality of nozzles which discharge ink; and a processor. The processor discharges ink onto a recording medium from the plurality of nozzles of the ink discharger, and uses the ink discharger to record on the recording medium a composite test image including a halftone image with a predetermined density and a defective nozzle specifying image which specifies a defective nozzle in which a defect in ink discharge is occurring. The processor obtains information regarding the defect in the ink discharge from the nozzle based on a density distribution of the halftone image read from read data of the composite test image and specifies a defective nozzle based on the above information and a portion in the defective nozzle specifying image of the read data.

Abstract: An inkjet recording device includes a hardware processor. The hardware processor: performs, for respective recording heads of a recorder, setting relevant to adjustment of an amount of ink to be discharged from nozzle groups; based on ink discharge amount information on a distribution of ink discharge amounts that are discharged from the nozzle groups based on image data, performs the setting such that at each joint in the nozzle groups, a difference between representative values of the ink discharge amounts of the nozzle groups satisfies a predetermined continuity condition, and a representative value of the ink discharge amounts of the nozzle groups satisfies a predetermined discharge amount condition; and adjusts at least a part of the setting such that a difference between a maximum value and a minimum value of the ink discharge amounts of the nozzle groups reduces.

Abstract: A first density correction is executed by calculating drive conditions for a plurality of recording heads based on density information of the respective recording heads derived from reading the test chart density so that the drive conditions are set for the recording heads. After execution of the first density correction, a second density correction is executed by calculating a density unevenness correction value based on the density information derived from reading the density of the printed test chart by the recording section again so that the image data are corrected based on the density unevenness correction value.

Abstract: An image forming device includes: a hardware processor that performs halftone processing on input image data using a threshold matrix of a dither method, and that, when dot missing exists in a formed image by the image forming part, performs interpolation by rearranging a missing dot to peripheral pixel position; and an image forming part that forms an image on a recording medium on the basis of image data after halftone processing by the halftone processing part, wherein the hardware processor, using the threshold matrix, sets a blank pixel having a high probability of being generated next when gradation is increased, as a rearrangement destination of the missing dot.

Abstract: An image recording device includes a recorder, a reader and a hardware processor. The recorder records an image on a recording medium. The reader reads, with an imaging element, a surface of the recording medium and a surface of a predetermined reference member. The hardware processor calibrates the reader for a value to be detected by the imaging element, based on a reading result of the reading of the surface of the reference member. Further, the hardware processor performs the calibration in at least one of: a case where a type of the image to be recorded on the recording medium satisfies a predetermined image type condition; and a case where a predetermined reading influence factor which affects a reading result of the reading of the surface of the recording medium satisfies a predetermined reading influence factor condition.

Abstract: An ink jet recording apparatus includes an ejector, a fixing unit, a reversing unit and a hardware processor. The ejector performs an ejection operation of ejecting a color material and an overcoat material onto a recording medium. The fixing unit fixes the overcoat material, thereby forming an overcoat on the medium. The reversing unit reverses the medium. The processor causes the fixing unit to form the overcoat on one side of the medium after causing the ejector to perform the ejection operation on the one side at a predetermined ejection position, causes the reversing unit to reverse the medium with the overcoat formed on the one side, and causes the fixing unit to form the overcoat on the other side of the medium after causing the ejector to perform the ejection operation on the other side at the ejection position.