There is provided a technology that enables reduction of an amount of data to be processed in testing a printed image printed on a printing medium. A printing apparatus includes a printing unit, a camera, and an image-data output unit. The printing unit is capable of printing plural categories of test patterns on the printing medium. The camera captures an image of a test pattern printed on the printing medium, and outputs acquired image data to the image-data output unit. The image-data output unit reduces an amount of data of the image data output from the camera, in accordance with the category of the test pattern, and outputs acquired image data to a test apparatus.

Provided are a density unevenness correction data creation method, a density unevenness correction data creation apparatus, a printing system, a program, a test chart, and a test chart data creation apparatus in which density unevenness correction with high accuracy is implemented. A captured image of a test chart including a density step pattern, an alignment mark, and a line mark is acquired, and in a case of acquiring correspondence relationship information between a theoretical position and an imaging position from the captured image, a rough correspondence relationship is acquired by using positional information of the alignment mark, a detailed correspondence relationship is acquired by using positional information of the line mark estimated by using the rough correspondence relationship, and density unevenness correction data is created by estimating a density value of each position of the density step pattern by using the detailed correspondence relationship.

Provided are a density unevenness correction data creation method, a density unevenness correction data creation apparatus, a printing system, a program, a test chart, and a test chart data creation apparatus in which density unevenness correction with high accuracy is implemented. A captured image of a test chart including a density step pattern, an alignment mark, and a line mark is acquired, and in a case of acquiring correspondence relationship information between a theoretical position and an imaging position from the captured image, a rough correspondence relationship is acquired by using positional information of the alignment mark, a detailed correspondence relationship is acquired by using positional information of the line mark estimated by using the rough correspondence relationship, and density unevenness correction data is created by estimating a density value of each position of the density step pattern by using the detailed correspondence relationship.

A continuous inkjet printer (50) has an ink droplet generator (52) and a controller (58) that varies a modulating voltage applied to the ink droplet generator (52) and measures corresponding breakup times of a jet of ink into ink droplets to obtain a portion of a characteristic of breakup time against modulating voltage. The controller (58) obtains a variation range, varies the modulating voltage over the variation range to obtain the portion of the characteristic, calculates a gradient from the portion of the characteristic, compares the gradient with a predetermined gradient and, depending on whether the calculated gradient is less than or greater than the predetermined gradient, generates an adjusted variation range that is displaced in a first sense or a second, opposite sense, respectively, relative to the variation range.

A print head for an inkjet printer includes a nozzle, a first electrode positioned to receive an ink droplet from the nozzle, a second electrode positioned to receive the ink droplet from the first electrode, and a controller configured to operate the first electrode to ionize the ink droplet and set a flight speed of the ink droplet. The controller is further configured to selectively activate the second electrode to deflect the ink droplet in response to the print head changing from a horizontal printing orientation to a vertical printing orientation.

Certain examples described herein relate to color calibration. In certain cases, a plurality of test patches are printed with a printing system, the test patches corresponding to a set of initial color sample points and a set of test colors. Color properties of the printed test patches are measured. In certain examples, a gamut descriptor is identified from a plurality of gamut descriptors using the color properties of the test colors. Each gamut descriptor defines a set of up-sampling parameters for a particular color gamut. Measured color properties for the initial color sample points are up-sampled using the set of up-sampling parameters for the identified gamut descriptor to generate up-sampled data. In certain cases, the up-sampled data is used to generate a color mapping to be applied to print job data received by the printing system.

Certain examples described herein relate to color calibration. In certain cases, a plurality of test patches are printed with a printing system, the test patches corresponding to a set of initial color sample points and a set of test colors. Color properties of the printed test patches are measured. In certain examples, a gamut descriptor is identified from a plurality of gamut descriptors using the color properties of the test colors. Each gamut descriptor defines a set of up-sampling parameters for a particular color gamut. Measured color properties for the initial color sample points are up-sampled using the set of up-sampling parameters for the identified gamut descriptor to generate up-sampled data. In certain cases, the up-sampled data is used to generate a color mapping to be applied to print job data received by the printing system.

The invention describes a number of methods and apparatus for shortening the inter-message gap on a continuous inkjet printer. Included is a novel phase testing methodology.

A printer having a printhead configured to print to a print medium; a camera configured to photograph the print medium; a carriage configured to support and move the printhead and the camera; and a processor configured to print, by the printhead, on the print medium a first test pattern that is larger than an imaging area of the camera, photograph the first test pattern by the camera, and detect a printing defect based on a result of the photograph.

A printer having a printhead configured to print to a print medium; a camera configured to photograph the print medium; a carriage configured to support and move the printhead and the camera; and a processor configured to print, by the printhead, on the print medium a first test pattern that is larger than an imaging area of the camera, photograph the first test pattern by the camera, and detect a printing defect based on a result of the photograph.