An inspection apparatus includes a liquid discharge head and a first light source. The liquid discharge head is configured to discharge a transparent liquid onto a discharged object. The first light source is configured to irradiate a pattern formed by the transparent liquid discharged onto the discharged object with light having a single peak wavelength to cause a difference between brightness and darkness.

A main TP is formed by N pattern element groups formed of a plurality of pattern elements disposed in cycles of N in a first direction, and disposed in positions shifted with respect to each other in a second direction intersecting the first direction. A first sub TP is configured by pattern elements printed by the nozzles used to print the pattern elements of the pattern element group positioned furthest away from the one region, in the second direction, among the N pattern element groups, and a second sub TP is configured by pattern elements printed by the nozzles used to print the pattern elements of the pattern element group positioned furthest away from the other region, in the second direction, among the N pattern element groups.

A printing apparatus includes a transport unit, a printing head, and a control unit that prints, on a printing medium, a test pattern for inspecting a state of ink discharge by a nozzles. The test pattern includes a first pattern element group in which a plurality of pattern elements to be printed by the nozzles are arranged in the transport direction, and a second pattern element group in which a plurality of pattern elements to be printed by the nozzles are arranged in the transport direction. After the control unit causes the transport unit to transport, by a distance equal to or greater than a nozzle pitch, the printing medium printed with the first pattern element group by causing the nozzles to discharge the ink, the control unit prints the second pattern element group on the printing medium by causing the nozzles used to print the first pattern element group to discharge the ink.

A method for modifying color density values in a dot-based printing system uses a control unit. The control unit implements the modification of the color density values after a raster image has been created and modifies the number and/or size of print dots to be applied to a printing substrate in order to attain pre-defined color density target values.

An ink discharge operation adjustment method includes the following, recording a halftone image in which the ink is discharged to form a predetermined halftone pattern and a solid image in which the ink completely covers a surface of the recording medium; obtaining a first reading result by a reader reading a non-recording region in which an image is not recorded on a recording medium; obtaining a second reading result of the halftone image and the solid image so that a difference of an elapsed time from a start of the curing to the reading is within a predetermined reference difference; obtaining coverage rate information based on the reading results; and performing setting regarding adjustment of a droplet amount of the ink based on the coverage rate information.

A print control apparatus that improves operability in readjusting a secondary transfer voltage that has been adjusted. The print control apparatus that communicates with an image forming apparatus. The print control apparatus includes an instruction unit that instructs the image forming apparatus to execute a process that prints a predetermined chart, reads the predetermined chart by the reading device, and sets a secondary transfer voltage, a reception unit that receives an adjustment value obtained by the process from the image forming apparatus, and a display control unit that controls a display unit to display an object that prompts a user to adjust at least the secondary transfer voltage based on reception of the adjustment value obtained by the process by the reception unit.

A printing apparatus includes a printing head including a nozzle configured to discharge ink, and a control unit configured to control the printing head to print a test pattern on a printing medium, for inspecting a state of ink discharge by the nozzle. The test pattern includes a pattern element formed by a plurality of dots of the ink, and the control unit causes the printing head to print the test pattern where a number of the dots forming the pattern element on a second printing medium is smaller than a number of the dots forming the pattern element on a first printing medium, the second printing medium being more susceptible to bleed-through of the ink than the first printing medium.

An image processing apparatus includes a hardware processor, an obtaining unit, a comparator, an adjuster and a notifying unit. The hardware processor obtains a read image from a reader that reads a print-through image formed on a back surface opposite an image forming surface of a recording medium. A target image is formed on the image forming surface with a color material, and the print-through image is formed on the back surface by the color material permeating through the recording medium. The obtaining unit obtains a comparison image in which the target image is at least recognizable. The comparator compares the read image with the comparison image. Depending on a result of the comparison by the comparator, the hardware processor causes at least one of (i) the adjuster to adjust a printing process parameter and (ii) the notifying unit to perform notification.

A printing apparatus acquires characteristic information about a recording medium and executes a light quantity adjustment in a reading operation using a reading unit based on the acquired characteristic information. By using the above-described configuration, it is possible to prevent an increase in the number of processes for analyzing read data obtained by reading a test pattern.

A method for determining a working gap includes a first recording step for ejecting ink from a recording head onto a first recording medium to record a test pattern, a first imaging step for capturing the test pattern recorded on the first recording medium in each of a state where a distance between the recording head and the first recording medium is a first distance, and a state where a distance between the recording head and the first recording medium is a second distance, a function calculating step, a second recording step for recording the test pattern on a second recording medium, a second imaging step for capturing the test pattern recorded on the second recording medium, and a working gap determining step for determining, based on the number of pixels of the captured test pattern and a function, a distance between the recording head and the second recording medium.