Printing method and printing apparatus

Patent metadata

Field	Value
Publication number	US-8926063-B2
Application number	US-201214125088-A
Country	US
Kind code	B2
Filing date	Jul 6, 2012
Priority date	Jul 15, 2011
Publication date	Jan 6, 2015
Grant date	Jan 6, 2015

Abstract

The invention aims to form an ink coating having a predetermined film thickness on a surface of a printing medium having a three-dimensional structure in shorter time. As solving means, a plurality of times of scanning process is included, ink 80 is discharged to head-facing areas ( 10 a, 10 c ) in a state of facing straight toward a printhead 110 in one scanning process, and the ink 80 is discharged to a non-head-facing area ( 10 b ) so that the total film thickness of the ink coatings ( 11, 12 ) to be formed without facing straight toward the printhead 110 in two or more times of the scanning process becomes a predetermined film thickness T 0 .

First claim

The invention claimed is:

1. A printing method comprising:
a plurality of times of a scanning process including scanning with a printhead for ink jet printing and discharging ink to a printing medium from the printhead, characterized in that including
differentiating head-facing areas to which the ink is discharged in a state of facing straight toward the printhead from each other in the respective scanning processes,
discharging the ink to a non-head-facing area to which the ink is discharged in a state of not facing straight toward the printhead in any of the scanning processes without facing the non-head-facing area straight toward the printhead also in other one or more scanning processes, and adjusting the amount of the ink to be discharged in the non-head-facing area in at least one of the scanning processes so that the total film thickness of the ink coating formed in the non-head-facing area becomes a predetermined film thickness, wherein when the ink is discharged to one point in the non-head-facing area in the n times (n is integers of 2 or larger) of the scanning process, an amount D i of the ink to be discharged to the point in the i-th scanning process is set so as to satisfy the following expression (2)
D i =k i ×D 0   (2)

(where D 0 denotes the amount of the ink to be discharged to one point in the head-facing area in the respective scanning processes) by using a coefficient of adjustment k i set so as to satisfy the following expression (1)

[

Expression
⁢

⁢
1

]

∑

i
=
1

n

⁢

(

k
i

⁢
cos
⁢

⁢

θ
i

)

=
1

(
1
)

(where θ i is an angle smaller than 90°, and indicates an angle formed between a discharging direction of the ink in the i-th scanning process among the n times of the scanning process and a normal direction of the printing medium at that time point.).

2. The printing method according to claim 1 , characterized in that the amount of the ink to be discharged in the non-head-facing area is adjusted so that the total film thickness of the ink coating formed in the non-head-facing area becomes equal to the film thickness of the ink coating to be formed in the head-facing area in the at least one of the scanning processes.

3. The printing method according to claim 1 , characterized in that the amount of the ink to be discharged in the non-head-facing area is adjusted to be smaller than the amount of ink to be discharged to the head-facing area in at least one of the scanning processes.

4. The printing method according to claim 1 , characterized in that scanning with the printhead is performed so as to transverse the head-facing area and the non-head-facing area in the at least one of the scanning processes.

5. The printing method according to claim 1 , characterized in that the ink is discharged without facing a second area, which is part of the printing medium, straight toward the printhead in two or more times of the scanning processes,
the two or more times of the scanning process includes two or more times of type 3 scanning process, and
the ink is discharged so that coatings of the ink having the same film thickness are formed in the second area in the respective times of the type 3 scanning process.

6. The printing method according to claim 1 , characterized in that the ink is discharged to a third area, which is part of the printing medium, without facing the third area straight toward the printhead in two or more times of the scanning processes,
the two or more times of the scanning process includes two or more times of type 4 scanning process,
scanning with the printhead is performed so as to transverse the third area and the head-facing area in the respective type 4 scanning processes, the same amount of the ink as the amount to be discharged to the head-facing area is discharged to a boundary between the third area and the head-facing area, and the amount of the ink to be discharged is continuously changed from the boundary to the third area.

7. The printing method according to claim 1 , characterized in that the ink is discharged to a fourth area, which is part of the printing medium, without facing the fourth area straight toward the printhead in two or more times of the scanning processes,
the two or more times of the scanning process includes two or more times of type 5 scanning process,
scanning with the printhead is performed so as to transverse the fourth area and the head-facing area in the respective type 5 scanning processes, the same amount of ink as the amount to be discharged to the head-facing area is discharged to a boundary between the fourth area and the head-facing area, and the amount of ink to be discharged is unevenly changed from the boundary to the fourth area.

8. The printing method according to claim 1 , characterized in that when scanning with the printhead is performed so as to transverse the head-facing area and the non-head-facing area and the amount of the ink to be discharged on the printing medium is changed between the head-facing area and the non-head-facing area in the scanning process, positions where the amount of the ink is changed are varied.

9. A printing apparatus comprising:
a printhead for ink jet printing;
scanning control means configured to control the printhead to perform a scanning process in which ink is discharged from the printhead to a printing medium while scanning with the printhead by a plurality of times; and
head-facing area changing means configured to differentiate head-facing areas to which the ink is discharged in a state of facing the printhead straight in front from each other in the respective scanning processes, characterized in that
the scanning control means controls the printhead so that the ink is discharged to a non-head-facing area to which the ink is discharged without facing the non-head-facing area straight toward the printhead in any of the scanning processes without facing straight toward the printhead also in other one or more scanning processes, and
the amount of the ink to be discharged in the non-

Assignees

• Ikeda Akira
• Ohnishi Masaru
• Mimaki Eng Kk

Inventors

• Ikeda Akira
• Ohnishi Masaru

Classifications

• B05C5/00

  Apparatus in which liquid or other fluent material is projected, poured or allowed to flow on to the surface of the work (B05C7/00 takes precedence; essentially involving spraying or electrostatic projection B05B) · CPC title

• B41J3/4073

  Printing on three-dimensional objects not being in sheet or web form, e.g. spherical or cubic objects (B41J3/283, B41J3/286 take precedence; building up a 3D object using individual droplets from jetting heads B29C64/112) · CPC title

• B41M5/0088 Primary

  by ink-jet printing · CPC title

• B41J25/304 Primary

  Bodily-movable mechanisms for print heads or carriages movable towards or from paper surface · CPC title