A method is provided that is implemented on a control device connected with an inkjet printer, which includes an inkjet head having an ink discharging surface, a head scanning unit reciprocating the inkjet head relative to a recording sheet along a scanning direction parallel to the ink discharging surface, and a wave shape generating mechanism deforming the recording sheet in a predetermined wave shape that has tops of portions protruding in a first direction toward the ink discharging surface and bottoms of portions recessed in a second direction opposite to the first direction alternately arranged along the scanning direction, the method including acquiring gap information related to a gap between the ink discharging surface and each individual one of the tops and the bottoms on the recording sheet, and determining whether the gap information acquired for each individual one of the tops and the bottoms is abnormal.

A print medium is conveyed in a first direction and a print head is provided with a reference side nozzle array and a plurality of nonreference side nozzle arrays. A relative position displacement amount between a reference printing position of a reference pattern printed by the reference side nozzle array and a nonreference printing position of each of nonreference patterns printed by each of the nonreference side nozzle arrays is detected. Based on a maximum value of a displacement amount of the reference printing position with respect to each of the nonreference printing positions in a direction opposite to the first direction, a first correction value for correcting displacement of the reference printing position is calculated. With reference to the reference printing position after corrected based on the first correction value, a second correction value for correcting displacement is calculated for each of the nonreference printing positions.

A method for manufacturing a liquid discharging apparatus having a liquid discharging head that is attached to an apparatus main body so as to be capable of being attached or detached and that discharges a liquid from a nozzle includes: identifying an alignment shift of the liquid discharging head attached to the apparatus main body; and identifying correction information that is correlated with the alignment shift identified in the identifying of the alignment shift based on a correction information table in which the correction information related to liquid discharge control and the alignment shift are correlated with each other.

An image forming apparatus includes: an extraction unit configured to extract an image for position detection from job image data; a first image forming unit configured to form the image for position detection on a recording medium; a second image forming unit disposed on a downstream in a feeding direction of the recording medium relative to the first image forming unit; a first detection unit configured to detect the image for position detection formed by the first image forming unit; and a determining unit configured to determine a correction amount of an image forming position of the second image forming unit based on a position of the image for position detection that is detected by the detection unit and a position of the image for position detection in the image data.

A distance measuring device includes: an imaging unit that captures a test pattern image including a pair of first markers and a second marker that is formed under a condition different from a condition applied to the first markers; a position detecting unit that detects a position of each of the pair of first markers and the second marker in a captured image captured by the imaging unit; a ratio calculating unit that calculates a ratio of a distance between the pair of the first markers in the captured image and an actual distance between the pair of the first markers; and an actual distance calculating unit that calculates an actual distance between one of the first markers as the pair and the second marker by multiplying a distance between the one of the first markers as the pair and the second marker in the captured image by the ratio.

There is provided a printer including: a conveyance unit; a liquid jetting head including at least one nozzle array in which nozzles are arrayed; a carriage; a guide; a carriage moving unit; a memory; and a controller. The controller performs printing by performing scan printing operation and a conveyance operation multiple times repeatedly and adjusts jetting timings of the liquid jetted from the nozzles at positions in a scanning direction based on pieces of inclination information corresponding to the respective positions. In second or subsequent scan printing operation of the multiple times of scan printing operation, the controller delays or advances, based on the inclination information, the jetting timing in the second or subsequent scan printing operation relative to the jetting timing in scan printing operation immediately before the second or subsequent scan printing operation more greatly, as inclination of the at least one nozzle array increases.

A printing apparatus, including a conveyor, a liquid ejection head with nozzles, a carriage, a carriage movement mechanism, and a controller, is provided. The controller executes a printing operation including a parameter determining process and an ejection timing determining process. In the parameter determining process, a value to a correction parameter is determined. In the ejection timing determining process, ejection timing to eject liquid through the nozzles is determined based on the value to the correction parameter. In the ejection timing determining process, the controller determines the ejection timing by shifting the ejection timing to be at least one of later and earlier than a reference timing for a time length corresponding to the value to the correction parameter. In the parameter determining process, the controller provides a different value to the correction parameter for the scan-printing action in the second unit-printing process depending on the nozzle shift amount.

An aim is to provide a technique for obtaining a higher quality print image by reducing a banding caused upon printing using a printing head having nozzle rows. As a solution, an activated nozzle row is reselected each time when the activated nozzle row has discharged ink for a preset number of times, and in each scan, an interval by which the activated nozzle row discharges ink in a main scanning direction is set to be an integer multiple of a resolution of an image to be printed on a print medium in the main scanning direction.

A liquid ejection apparatus corrects image data by: setting a to-be-corrected dot element; acquiring a correction amount based on an offset between a formation position at which a dot corresponding to the to-be-corrected dot element is to be formed on a recording medium while the recording medium is conveyed the reference conveyance amount per unit time and a formation position at which a dot corresponding to the to-be-corrected dot element is to be formed while the recording medium is conveyed a conveyance amount different from the reference conveyance amount per unit time; and executing correction on the to-be-corrected dot element. The correction is executed by setting a density value for the to-be-corrected dot element as that for corresponding one dot element whose data array order is shifted from a data array order of the to-be-corrected dot element by the number of dot elements corresponding to the correction amount.

A printing system includes an identification module to identify a number of the encoder pulses generated by an encoder at a rate corresponding to a speed of a media during a time interval. The printing system also includes an alignment module to at least one of change the number of encoder pulses or scale the encoder pulses generated by the encoder based on an amount of variation between the number of encoder pulses detected and the number of encoder pulses to maintain the number of encoder pulses constant.