An image forming apparatus includes (a) recording heads that are mounted on a carriage, (b) a pattern image formation processing part that forms a test pattern image on a recording medium at a pattern image formation position, (c) an optical detection part that emits light onto the recording medium, receives reflection light, and generates a sensor output in correspondence with the reflection light, (d) a pattern image detection processing part that detects the test pattern image at the pattern image formation position, generating a detection result, (e) an image forming condition setting part that sets an image forming condition based on the detection result of the test pattern image, and (f) dense parts and pale parts are alternately formed in the test pattern image.

A liquid ejecting device includes a supporting unit supporting a medium, an ejecting unit ejecting liquid onto the medium, a scanning driving unit moving the ejecting unit, and a control unit controlling the ejecting unit and the scanning driving unit. The control unit is configured to be capable of performing, a first processing for forming a test pattern, and acquiring an ejection velocity parameter associated with an ejection velocity of the liquid detected from the test pattern, a second processing for calculating the ejection velocity of the liquid from the ejection velocity parameter, calculating a first correction component that depends on the calculated ejection velocity, and setting a correction value including the first correction component, and a third processing for correcting ejection timing of the liquid using the correction value, when the liquid is ejected from the ejecting unit onto the medium as the ejecting unit is moved.

A method for determining a recording timing includes: recording patches disposed along a second axis with a recording head; and determining a recording timing of the recording head based on a selected recorded patch; wherein the patches each include an overlap region, a first region, and a second region; AB is satisfied, where A is a width along the second axis of the first region and the second region, and B is a width along the second axis of the overlap region; the width B is recorded decreasing towards both ends along the second axis; and the recording includes a first recording in which the recording head moves in a first direction along the second axis and the overlap region is recorded with a first nozzle group and the first region is recorded with a third nozzle group, and a second recording in which the recording head moves in a second direction and the overlap region is recorded with a second nozzle group and the second region is recorded with the third nozzle group.

To predict more accurately whether ink dots formed on the surface of paper by two nozzles arranged in a nozzle row and located at positions close to each other overlap. A luminance amount for each unit area surrounding each chart is derived from scanned data obtained by reading results of printing a plurality of charts (two-dot line chart corresponding to a nozzle pair of a nozzle of interest and a neighboring nozzle thereof among the plurality of nozzles) associated with a plurality of nozzles respectively. Then, based on the luminance amount for each unit area, the dot formation state in a dot formation line by the plurality of nozzles is determined.

Examples associated with printer configuration are disclosed. One example includes printing, using a printer, a first portion of a test patch in a first print direction. A second portion of the test patch is printed in a second print direction. The second portion is printed at a first offset from the first portion. A first portion of a second test patch is printed in the first print direction, and a second portion of the second test patch is printed in the second print direction at a second offset from the first portion of the second test patch. The printer is configured to print in the second print direction using one of the first offset and the second offset based on a selection between the first test patch and the second test patch.

An inkjet printer is provided, which is configured to acquire gap information related to a gap between an ink discharging surface and a recording sheet in each individual position of top-formed positions and bottom-formed positions within a predetermined wave-shape generating range, identify, when the predetermined wave-shape generating range includes a partial range in which the recording sheet is not placed, a top-formed position where the gap information has not been acquired and a bottom-formed position where the gap information has not been acquired, within the partial range, complement the unacquired gap information in the identified top-formed position with a value determined based on the respective pieces of gap information acquired in other top-formed positions, and complement the unacquired gap information in the identified bottom-formed position with a value determined based on the respective pieces of gap information acquired in other bottom-formed positions.

An inkjet printer including an inkjet head, a head scanning unit, a wave shape generating mechanism to deform a recording medium into a predetermined wave shape, an obtaining device to obtain information concerning a type of the recording medium to be used in a printing operation, a gap information storing device to store gap information related to a gap between an ink discharging surface and the recording medium in association with a predetermined type of the recording medium, the gap information being acquired from a predetermined range in the recording medium, and a correcting device to correct the gap information according to the type of the recording medium obtained by the obtaining device when the type of the recording medium obtained by the obtaining device is different from the predetermined type of the recording medium stored in association with the gap information, is provided.

A method of printing an image using a printing system having first and second overlapping printhead segments. The method includes the steps of: (i) identifying a strip of the image to be printed in an overlap region of the first and second printhead segments; (ii) determining a stitching technique for the first and second printhead segments; and (iii) printing the image using the first and second printhead segments, the printing including stitching the first and second printhead segments in the overlap region using the determined stitching technique. The stitching technique may be a butt stitch or a feathered stitch, dependent on image content in the strip.

A print device includes a first head, a second head, a platen, a guide member, a receiving portion, a processor, and a memory that stores computer-readable instructions that cause the print device to perform processes including: test printing that involves printing a test pattern by ejecting the second ink at a first timing and a second timing at a first sub-scanning direction position, and further, ejecting the second ink at a third timing and a fourth timing at a second sub-scanning direction position; and determining that involves, when one of the first and the second timing is received, determining the received timing to be the ejection timing of the second ink at the first sub-scanning direction position, and, when one of the third and the fourth timing is received, determining the received timing to be the ejection timing of the second ink at the second sub-scanning direction position.

A liquid discharge apparatus includes a recording head configured to discharge a liquid to form a pattern on a recording medium and a reading device configured to read the pattern. The apparatus further includes circuitry configured to form at least two first markers while moving the recording head relative to the recording medium in a head movement direction; form a second marker at one of positions of the at least two first markers, to form a pattern including a reference marker formed with one of the at least two first markers and a measurement marker in which the second marker is overlaid on another of the at least two first markers; and measure a distance between the reference marker and the measurement marker in the head movement direction based on information obtained by the reading device.