Inkjet printing device and inkjet printing method

An inkjet printing method by an inkjet printing device comprising a print head that ejects a plurality of types of inks including a first ink having a first contact angle to a surface of a predetermined print medium and a second ink having a second contact angle to the surface which is smaller than the first contact angle, the inkjet printing method including:

• an obtaining step of obtaining ejection data representing an application amount of the first ink and the second ink to be ejected to a predetermined area;
• an ejection step of, on the basis of ejection data obtained by the obtaining step, scanning the print head a plurality of times relatively to a predetermined area of a print medium, and ejecting the plurality of types of inks from the print head to the predetermined area to print an image,
• wherein if the ejection data represents that the application amount of the first ink is larger than the application amount of the second ink by more than a predetermined value in the plurality of times of scans, the second ink is ejected in the ejection step such that an application amount of the second ink to be ejected in last half scans is greater than an application amount of the second ink to be ejected in first half scans, and
• wherein if the ejection data represents that the application amount of the second ink is larger than the application amount of the first ink by more than a predetermined value in the plurality of times of scans, the first ink is ejected in the ejection step such that an application amount of the first ink to be ejected in the last half scans is greater than an application amount of the first ink to be ejected in the first half scans.

An inkjet printing method by an inkjet printing device having a print head provided with:

• ejection ports that eject a plurality of types of inks including a first ink having a first contact angle to a surface of a predetermined print medium and a second ink having a second contact angle to the surface which is smaller than the first contact angle;
• and an ejection port that ejects processing liquid having a property of improving performance of an image, the inkjet printing method including:
• an obtaining step of obtaining ejection data representing an application amount of the first ink and the second ink to be ejected to a predetermined area;
• an ejection step of, on the basis of ejection data obtained by the obtaining step, scanning the print head a plurality of times relatively to a predetermined area of a print medium, ejecting the plurality of types of inks from the print head to the predetermined area to print an image, and the a basis of ejection data that scans the print head to eject the processing liquid from the print head to the predetermined area, and ejecting the processing liquid from the print head onto the image and thereby cover the image with the processing liquid;
• wherein if the ejection data obtained by the obtaining unit represents that the application amount of the first ink is larger than the application amount of the second ink by more than a predetermined value in the plurality of times of scans, the ejection unit ejects the second ink such that an application amount of the second ink to be ejected in last half scans is greater than an application amount of the second ink to be ejected in first half scans, and
• wherein if the ejection data obtained by the obtaining unit represents that the application amount of the second ink is larger than the application amount of the first ink by more than a predetermined value in the plurality of times of scans, the ejection unit ejects the first ink such that an application amount of the first ink to be ejected in the last half scans is greater than an application amount of the first ink to be ejected in the first half scans, and thereby controls a surface roughness value of the image to be printed with the plurality of types of inks to fall within a predetermined range.