Inkjet printing apparatus and inkjet printing method

Patent metadata

Field	Value
Publication number	US-11077687-B2
Application number	US-202016823875-A
Country	US
Kind code	B2
Filing date	Mar 19, 2020
Priority date	Mar 27, 2019
Publication date	Aug 3, 2021
Grant date	Aug 3, 2021

Abstract

Images with high image quality having less time-difference unevenness are outputted in an inkjet printing apparatus that performs multi-pass printing using full-line inkjet print heads 2 . For this purpose, a CPU is capable of setting a first printing method in which an image for a unit area is printed by a specified number of printing conveyance operations and a second printing method in which an image for a unit area is printed by a smaller number than the specified number of printing conveyance operations. The CPU sets conveyance conditions such that a taken time for one printing conveyance operation of the printing conveyance operations for a unit area in the second printing method is smaller than a taken time for one successive printing conveyance operation of the printing conveyance operations for a unit area in the first printing method.

First claim

What is claimed is:

1. An inkjet printing apparatus comprising:
a print head that has multiple nozzles configured to eject ink and arrayed in a first direction;
a conveying unit capable of conveying a print medium relative to the print head in a second direction intersecting the first direction and in a third direction opposite to the second direction; and
a control unit configured to control the print head and the conveying unit such that an image for a unit area is printed by multiple printing conveyance operations in which a printing conveyance operation for conveying the print medium in the second direction while ejecting ink to the unit area of the print medium and a printing conveyance operation for conveying the print medium in the third direction while ejecting ink to the unit area of the print medium are repeated alternately, wherein
the control unit is capable of setting a first printing method in which an image for a unit area is printed by a specified number of the printing conveyance operations and a second printing method in which an image for a unit area is printed by a smaller number than the specified number of the printing conveyance operations, and
the control unit sets the first printing method and the second printing method such that a time to be taken for one printing conveyance operation of the printing conveyance operations for a unit area in the second printing method is smaller than a time to be taken for one printing conveyance operation of the printing conveyance operations for a unit area in the first printing method.

2. The inkjet printing apparatus according to claim 1 , wherein
the control unit makes the time to be taken for one printing conveyance operation in the second printing method shorter than the time to be taken for one printing conveyance operation in the first printing method by making a width of a unit area in a direction of the conveyance in the second printing method smaller than the width in the first printing method.

3. The inkjet printing apparatus according to claim 2 , wherein
the control unit sets the width differently depending on the type of print medium.

4. The inkjet printing apparatus according to claim 3 , wherein
the control unit sets the second printing method such that the width for a first print medium that is relatively glossy is smaller than the width for a second print medium that is relatively less glossy.

5. The inkjet printing apparatus according to claim 3 , wherein
the control unit sets the second printing method such that the width for a print medium with a coating layer having at least one of a function for receiving ink and a function for reacting with ink is smaller than the width for a print medium without the coating layer.

6. The inkjet printing apparatus according to claim 1 , wherein
the control unit makes the time to be taken for one printing conveyance operation in the second printing method shorter than the time to be taken for one printing conveyance operation in the first printing method by making conveyance speed of the printing conveyance operation in the second printing method higher than the conveyance speed in the first printing method.

7. The inkjet printing apparatus according to claim 6 , wherein
the control unit sets the conveyance speed differently depending on the type of print medium.

8. The inkjet printing apparatus according to claim 7 , wherein
the control unit sets the second printing method such that the conveyance speed of a first print medium that is relatively glossy is higher than the conveyance speed of a second print medium that is relatively less glossy.

9. The inkjet printing apparatus according to claim 7 , wherein
the control unit sets the second printing method such that the conveyance speed of a print medium with a coating layer having at least one of a function for receiving ink and a function for reacting with ink is higher than the conveyance speed of a print medium without the coating layer.

10. The inkjet printing apparatus according to claim 1 , wherein
the print head has nozzle rows each composed of multiple nozzles configured to eject ink and arrayed in the first direction, and each of the nozzle rows is associated with a different color.

11. The inkjet printing apparatus according to claim 1 , wherein
the print medium is a long length of a print medium held in the form of a roll.

12. An inkjet printing method for an inkjet printing apparatus including:
a print head that has multiple nozzles configured to eject ink and arrayed in a first direction; and
a conveying unit capable of conveying a print medium relative to the print head in a second direction intersecting the first direction and in a third direction opposite to the second direction, wherein
an image for a unit area is printed by multiple printing conveyance operations in which a printing conveyance operation for conveying the print medium in the second direction while ejecting ink to the unit area of the print medium and a printing conveyance operation for conveying the print medium in the third direction while ejecting ink to the unit area of the print medium are repeated alternately,
a first printing method and a second printing method are settable; in the first printing method, an image for a unit area is printed by a specified number of the printing conveyance operations; and in the second printing method, an image for a unit area is printed by a smaller number than the specified number of the printing conveyance operations, and
the first printing method and the second printing method are set such that a taken time for one printing conveyance operation of the printing conveyance operations for a unit area in the second printing method is smaller than a taken time for one printing conveyance operation of the printing conveyance operations for a unit area in the first printing method.

Assignees

• Canon Kk

Inventors

• Nishioka Shingo
• Mogi Sae
• Azuma Satoshi
• Sato Kazuhiko
• Genta Shin
• Nagamura Mitsutoshi
• Kato Masataka
• Nakajima Yoshinori
• Suzuki Kazuo

Classifications

• B41J25/006 Primary

  for oscillating, e.g. page-width print heads provided with counter-balancing means or shock absorbers · CPC title

• B41J2/16538

  with brushes or wiper blades perpendicular to the nozzle plate · CPC title

• B41J2/2132

  Print quality control characterised by dot disposition, e.g. for reducing white stripes or banding (methods for local corrections by dot omission, image edge enhancement, or multi-pass mask selection G06K15/102; colour conversion H04N1/40) · CPC title

• B41J2/16585 Primary

  for paper-width or non-reciprocating print heads · CPC title