Printing apparatus and printing method

Patent metadata

Field	Value
Publication number	US-10940695-B2
Application number	US-202016790774-A
Country	US
Kind code	B2
Filing date	Feb 14, 2020
Priority date	Dec 16, 2015
Publication date	Mar 9, 2021
Grant date	Mar 9, 2021

Abstract

The present disclosure prevents a visible pattern corresponding to the pattern of a mask from being noticeable and enables more appropriate printing. A printing apparatus 10 performing printing by an inkjet scheme includes: an inkjet head 102; and a controller 20, configured to control the operation of a main scan driver 16 and a sub scan driver 18 to perform a main scanning operation multiple times on each position on a medium 50. In the main scanning operation, for at least part of ejection positions serving as ejection targets of ink droplets in the main scanning operation, the controller 20 causes the inkjet head 102 to eject an ink droplet in accordance with a mask for selecting part of the at least part of ejection positions. In the main scanning operation at one time, the controller 20 causes the inkjet head 102 to eject an ink droplet in accordance with a preset first mask. In the main scanning operation at another time different from the one time, the controller 20 causes the inkjet head 102 to eject an ink droplet in accordance with a second mask for selecting an ejection position in a pattern different from the first mask.

First claim

The invention claimed is:

1. A printing apparatus configured to perform printing on a medium by an inkjet scheme, comprising:
an inkjet head, configured to eject an ink droplet by the inkjet scheme;
a main scan driver, configured to cause the inkjet head to perform a main scanning operation of ejecting the ink droplet while moving relative to the medium in a preset main scanning direction;
a sub scan driver, configured to cause the inkjet head to perform a sub scanning operation of moving relative to the medium in a sub scanning direction orthogonal to the main scanning direction; and
a controller, configured to control operation of the main scan driver and the sub scan driver to perform the main scanning operation a plurality of times on each ejection region on the medium, wherein
the inject head has a nozzle row in which a plurality of nozzles are arranged in the sub-scanning direction,
in one sub scanning operation subsequent to one main scanning operation, a feed amount in the sub scanning direction is a distance that is shorter than a length of the nozzle row,
an ejection region for ejecting the ink droplet at a subsequent main scanning operation of the one main scanning operation at least partially overlaps with an ejection region for ejecting the ink droplet at the one main scanning operation,
a duty that is a ratio of ejection positions to which the ink droplets are ejected in each of the main scanning operations is different between an overlapping region and non-overlapping region,
wherein the controller sets the overlapping region that is the ejection region overlapped with each other and the non-overlapping region that is the ejection region not overlapped with each other when performing the main scanning operation of ejecting the ink droplet each time according to a number of passes of the inkjet head,
wherein when the number of passes is a non-integer number smaller than 2, the ink droplets are ejected using a plurality of masks having irregular mask patterns in the ejection positions in the overlapping region,
wherein the ink droplets are ejected without applying a mask in the non-overlapping region, and the ratio of the ejection positions for ejecting the ink droplets is different from the overlapping region.

2. The printing apparatus according to claim 1 , wherein
the controller comprises:
in each of the main scanning operations, using a mask that selects part of the at least part of the ejection positions serving as ejection targets of the ink droplets in the main scanning operation, the inkjet head ejects the ink droplet to the ejection positions specified by the mask.

3. The printing apparatus according to claim 2 , wherein
the ink droplet is ejected by using a different type of the mask for each overlapping region.

4. The printing apparatus according to claim 3 , wherein
a plurality of types of masks having different patterns are used in the main scanning operation a plurality of times, and the plurality types of masks are obtained by shifting predetermined patterns in parallel by different distances from each other.

5. The printing apparatus according to claim 2 , wherein
in the overlapping region, the mask used in the one main scanning operation is in a complementary relation with the mask used in the subsequent main scanning operation.

6. The printing apparatus according to claim 1 , wherein
the ink droplet is ejected by using a different type of the mask for each overlapping region.

7. The printing apparatus according to claim 6 , wherein
in the overlapping region, the mask used in the one main scanning operation is in a complementary relation with the mask used in the subsequent main scanning operation.

8. The printing apparatus according to claim 6 , wherein
a plurality of types of masks having different patterns are used in the main scanning operation a plurality of times, the plurality types of masks are obtained by shifting predetermined patterns in parallel by different distances from each other.

9. The printing apparatus according to claim 1 , wherein
in the overlapping region, the mask used in the one main scanning operation is in a complementary relation with the mask used in the subsequent main scanning operation.

Assignees

• Mimaki Eng Co Ltd

Inventors

• Ohara Eiichi
• Takatsu Akira

Classifications

• G06K15/107 Primary

  Mask selection · 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

• G06K2215/0094

  Colour printing · CPC title

• B41J2/21

  for multi-colour printing · CPC title

• B41J2/2054

  by the variation of dot disposition or characteristics, e.g. dot number density, dot shape · CPC title