WO2006051734A1

WO2006051734A1 - Inkjet printer

Info

Publication number: WO2006051734A1
Application number: PCT/JP2005/020265
Authority: WO
Inventors: Tsutomu Yoneyama
Original assignee: Konica Minolta Medical & Graphic, Inc.
Priority date: 2004-11-15
Filing date: 2005-11-04
Publication date: 2006-05-18
Also published as: JP2006137128A

Abstract

Disclosed is an inkjet printer comprising a recording head (10) for discharging a lipophilic ink and a transfer belt (7) onto which the ink is discharged from the recording head (10). The transfer belt (7) is provided with a plurality of lipophilic regions (8), and the area between the lipophilic regions is formed as an oil repellent region (9).

Description

Specification

Inkjet printer technology

The present invention relates to an ink jet printer that transfers ink from a transfer member to a recording medium and records an image on the recording medium.

Background art

Conventionally, a transfer type ink jet printer is known as an embodiment of an ink jet printer. This transfer type ink jet printer is configured to eject ink from a recording head toward a transfer body, transfer the ink landed on the transfer body to a recording medium, and record an image on the recording medium. .

A specific example of a transfer type ink jet printer is disclosed in Patent Document 1. The ink jet printer described in Patent Document 1 uses an ultraviolet curable ink as the ink, and irradiates the ink that has landed on the transfer body with ultraviolet rays before transfer, and transfers the ink to a recording medium in a semi-cured state. ing.

Patent Document 1: JP 2001-179960 A

Disclosure of the invention

Problems to be solved by the invention

[0004] However, in the transfer type ink jet printer including the ink jet printer of Patent Document 1, immediately after the ink has landed on the transfer body, the landed inks (dots) cross each other on the transfer body. The phenomenon of adhering to each other (beading) occurs, resulting in a decrease in image quality.

[0005] An object of the present invention is to prevent the occurrence of beading.

Means for solving the problem

[0006] The problems of the invention are solved by the following embodiments.

[0007] In order to solve the above problems, the inkjet printer of the invention described in Example 1

A recording head for discharging oleophilic ink;

A transfer body that receives the ejection of the ink by the recording head; With

A plurality of lipophilic regions are formed on the transfer body, and a gap between the lipophilic regions serves as an oil repellent region.

[0008] The invention described in Example 2

In the ink jet printer described in Example 1,

The recording head has a plurality of ejection holes for ejecting the ink as droplets, and the interval between the ejection holes is twice or more the interval between the lipophilic regions.

[0009] The invention described in Example 3

In the inkjet printer described in Example 1 or 2,

The ratio of the width of each lipophilic region to the width of the oil repellent region is 3 or more.

[0010] The invention described in Example 4

The ink jet printer according to any one of Examples 1 to 3, wherein each of the lipophilic regions is a concave portion.

[0011] The invention described in Example 5

The ink jet printer according to any one of Examples 1 to 4, wherein the transfer body has a belt shape.

[0012] The invention described in Example 6

The ink jet printer according to any one of Examples 1 to 4, wherein the transfer body has a drum shape.

[0013] The invention described in Example 7

In the ink jet printer according to any one of Examples 1 to 6, a transfer unit that transfers the ink landed on the transfer body to a recording medium, an irradiation device that irradiates the recording medium with ultraviolet rays,

With

The ink is an ultraviolet curable ink that is cured by being irradiated with ultraviolet rays, and is transferred from the transfer body to the recording medium by the transfer unit, and then is purple by the irradiation device. Characterized by receiving an outside line.

Brief Description of Drawings

FIG. 1 is a side view showing a schematic configuration of an inkjet printer 1.

2 is a perspective view showing a schematic configuration of a transfer device 3. FIG.

FIG. 3 is a plan view showing a configuration on the surface of a transfer belt 7.

FIG. 4 is a sectional view showing a modification of the surface configuration of the transfer belt 7.

Explanation of symbols

[0015] 1 Inkjet printer

2 Recording media

3 Transfer device

4 Transfer roller (Transfer means)

5 Guide roller

6 Guide roller

7 Transfer belt (transfer body)

8 Lipophilic area

9 Oil repellent area

10 recording heads,

11 Discharge hole

15 Cleaning device

20 Transport device

21 Transport roller

22 Guide roller

23 Guide roller

25 Irradiation equipment

26 Light source

27 Reflector

BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, the best mode for carrying out the present invention will be described with reference to the drawings. . However, the scope of the invention is not limited to the illustrated examples.

FIG. 1 is a side view showing a schematic configuration of an inkjet printer 1 according to the present invention.

As shown in FIG. 1, the ink jet printer 1 has a transfer device 3 that transfers ink to a recording medium 2. The transfer device 3 includes a transfer roller 4 that rotates counterclockwise in FIG. 1 and two guide rollers 5 and 6, and an endless transfer belt between the transfer roller 4 and the guide rollers 5 and 6. 7 has been wound. As the transfer roller 4 rotates, the transfer belt 7 rotates counterclockwise in FIG. 1 (see the arrow in FIG. 1).

FIG. 2 is a perspective view showing a schematic configuration of the transfer device 3.

As shown in FIGS. 1 and 2, the transfer belt 7 has a width substantially the same as the length of the transfer roller 4 and the guide rollers 5 and 6. A plurality of lipophilic regions 8, 8,... Are regularly formed on the surface of the transfer belt 7, and a gap between each lipophilic region 8 is an oil repellent region 9. Each lipophilic region 8 and oil repellent region 9 exist on substantially the same plane of the transfer belt 7.

The transfer belt 7 also has a natural rubber or synthetic rubber force. When the transfer belt 7 is composed of synthetic rubber, it is preferable to use a material mainly composed of ethylene-propylene rubber, nitrile rubber, etc. as the synthetic rubber.

[0022] In addition to the above materials, the transfer belt 7 includes polyimide (PI), polyphenylene sulfide (PPS), polyethersulfone (PES), polyamide (PA), polyethylene terephthalate (PET), polyimide amide ( Plastic material forces such as PIA) may also be configured. When the transfer belt 7 is composed of the above plastic material cover, the transfer belt 7 can be formed by forming a seamless belt of the plastic material by inflation molding or the like and then rolling it. The transfer belt 7 can also be formed by thermally fusing a sheet of plastic material.

In the present embodiment, the surface of the transfer belt 7 in which the above-described material force is also formed becomes the lipophilic regions 8 as they are, and the lipophilic regions 8 are formed from the material cartridges that constitute the transfer belt 7. ing.

[0024] The oil-repellent region 9 is formed by selectively coating the surface of the transfer belt 7 with fluorine-based resin, and is composed of fluorine-based resin. The oil-repellent region 9 may be formed by coating with a hydrophilic material, for example —OH, —COOH, —NH Apply a material (compound) containing any functional group of CO as the hydrophilic material.

2

It can be done.

FIG. 3 is a drawing showing the surface of the transfer belt 7 in detail, and is a plan view of the transfer belt 7.

As shown in FIG. 3, each lipophilic region 8 has a circular shape and is arranged in a matrix at regular intervals. The ratio of the width W2 of each lipophilic region 8 to the width W1 of the oil repellent region 9 sandwiched between the two lipophilic regions 8 and 8 adjacent to each other is 3 or more.

The ratio of the width W2 to the width W1 is set to 3 or more because if the ratio of the width W2 to the width W1 is less than 3, the ink adhering to the transfer belt 7 remains in the oil-repellent region 9 and the ink Cannot be dispersed and held in each lipophilic region 8, and when the ink is transferred from the transfer belt 7 to the recording medium 2, the graininess of the dots is not uniform and pinholes are easily formed. This is because, in the oil-repellent region 9, there is a marked difference in the density of the ink between the portion where a large amount of ink remains and the portion where a small amount of ink remains.

As shown in FIG. 1, a recording head 10 that ejects ink is disposed above the transfer device 3. The ink ejected from the recording head 10 is an oleophilic ink and is an ultraviolet curable ink that cures when irradiated with ultraviolet rays. The recording head 10 is a line head extending from the front side to the back side in FIG. 1, and ejects ink toward the transfer belt 7 straddled between the guide rollers 5 and 6. A plurality of ejection holes 11, 11,... (See FIG. 3) along the width direction of the transfer belt 7 are arranged in a row at equal intervals in the lower part of the recording head 10. Ink is ejected as droplets.

As shown in FIG. 3, the interval P 1 between the ejection holes 11 of the recording head 10 (the distance between the central portions of the two adjacent ejection holes 11, 11) is the distance between the lipophilic regions 8 of the transfer belt 7. It is more than twice the interval P2 (distance between the central parts of two adjacent lipophilic regions 8, 8).

[0030] The interval P1 is set to be not less than twice the interval P2, because the ink droplets discharged from each discharge hole 11 can be dispersed in a plurality of lipophilic regions 8, 8,. This is because the image quality can be improved by improving the graininess or reducing the thickness of the dots.

As shown in FIG. 1, on the right side of the transfer device 3 is a tally that cleans the transfer belt 7. Jung device 15 is arranged. The cleaning device 15 is disposed opposite to the transfer belt 7 between the transfer roller 4 and the guide roller 6 and removes ink remaining on the transfer belt 7 from the transfer belt 7! / RU

A transfer device 20 for transferring the recording medium 2 is arranged below the transfer device 3. The transport device 20 includes a transport roller 21 that rotates clockwise in FIG. 1 and two guide rollers 22 and 23. The transport roller 21 is disposed opposite to the transfer roller 4 of the transfer device 3.

[0033] A recording medium 2 is placed between the conveying roller 21 and the guide rollers 22 and 23. When the conveying roller 21 rotates, the recording medium 2 passes from the guide roller 22 through the conveying roller 21 to the guide roller 23. (See the arrows in Fig. 1).

An irradiation device 25 that irradiates the recording medium 2 with ultraviolet rays is disposed between the conveyance roller 21 and the guide roller 23. The irradiation device 25 has three light sources 26, 26, 26 and a reflector 27. Each light source 26 is a linear light source whose front side force in FIG. 1 extends to the back side, and emits ultraviolet rays when turned on. When each light source 26 is turned on, the ultraviolet light is directly incident on the recording medium 2 from each light source 26 or is reflected by the reflecting plate 27 and indirectly incident on the recording medium 2.

Next, the operation / action of the inkjet printer 1 will be described.

[0036] In a state where the transfer roller 4 and the transport roller 21 are rotated and each light source 26 of the irradiation device 25 is turned on, the recording head 10 ejects ink toward the transfer belt 7, and the ink is transferred to the transfer belt. Land on 7 and pass through guide roller 5. After that, when the ink landed on the transfer belt 7 reaches the vicinity of the transfer roller 4, the transfer roller 7 is pressed against the conveying belt 21 while the transfer roller 4 rotates as a transfer means, and ink is used as a transfer body. Transfer from the transfer roller 7 to the recording medium 2.

The ink transferred to the recording medium 2 is also transported to the guide roller 23 as the transport roller 21 rotates, and is cured by being irradiated with ultraviolet rays from each light source 26 in the middle thereof. On the other hand, the ink remaining on the transfer belt 7 without being transferred to the recording medium 2 is transported from the transfer belt 7 toward the guide roller 6 as the transfer belt 7 rotates, and is transferred by the cleaning device 15 during the transport. Removed from roller 7.

[0038] Thereafter, the ink jet printer 1 repeats the above operation, and the recording medium 2 is desired. Images are recorded.

[0039] In the above-described ink jet printer 1, each lipophilic region 8 is formed in a matrix on the surface of the transfer belt 7, and the gap between each lipophilic region 8 becomes the oil repellent region 9. On the surface of the copying belt 7, a lipophilic region 8 and an oil repellent region 9 are alternately arranged. For this reason, when ink ejected from the recording head 10 lands on both the lipophilic region 8 and the oil repellant region 9 of the transfer belt 7, the ink on the oil repellant region 9 is subjected to the oil repellency and is oleophilic. The ink that has moved to the region 8 and landed on the transfer belt 7 exists on the surface of the transfer belt 7 in a state of being dispersed and spaced apart from each other in the lipophilic region 8 so as to be separated from each other.

More specifically, as shown in FIG. 3, four oleophilic regions 8a, 8b, 8c, 8d and their gaps are formed as ink force droplets ejected from one ejection hole 11 with the recording head 10. In the case of landing over the oil repellency area 9 (see the two-dot chain line), the ink droplets are separated from each other so that the ink on the oil repellency area 9 is separated from each other due to the oil repellency. They move to 8a, 8b, 8c, 8d and exist as four droplets at a distance from each other. From the above, it is possible to effectively prevent the occurrence of beading on the surface of the transfer belt 7 where the ink does not mix and adhere to each other.

[0041] It should be noted that the present invention is not limited to the above embodiment, and various improvements and design changes may be made without departing from the spirit of the present invention!

[0042] As one improvement 'design change, the planar shape of each lipophilic region 8 may have an elliptical shape, a polygonal shape such as a triangular shape or a rectangular shape, or the like. It may have the shape of

[0043] As another improvement and design change, as shown in FIG. 4, each lipophilic region 8 may be a recess. In this case, the cross-sectional shape of each lipophilic region 8 may have an arc shape, may have a U shape, or may have a V shape. Furthermore, in this case, each lipophilic region 8 should have a ratio of the depth D to the width W2 of 0.3 or less. The ratio of the depth D to the width W2 is set to 0.3 or less when the ratio of the depth D to the width W2 exceeds 0.3. This is because the transfer efficiency of the ink from the transfer belt 7 to the recording medium 2 is remarkably lowered, or the clogging of the ink occurs in the recess. As another improvement and design change, a rotatable drum-shaped transfer body having a surface configuration similar to the surface of the transfer belt 7 may be applied instead of the transfer device 3. In this case, the drum-shaped transfer member itself serves as a transfer means to transfer the ink to the recording medium 2 while rotating.

As another improvement / design change, a serial type recording head that moves back and forth in FIG. 1 instead of the recording head 10 may be applied.

Industrial applicability

[0046] According to the inventions described in Examples 1 to 7, the lipophilic areas and the oil-repellent areas are alternately arranged on the transfer body, and the ink ejected from the recording head is the lipophilic area of the transfer body. And the oil-repellent area, the ink on the oil-repellent area is moved to the lipophilic area due to the oil-repellent action, and the ink that has landed on the transfer body is separated from each other on the transfer body. In a state where they are dispersed in each lipophilic region and spaced apart from each other. Therefore, it is possible to effectively prevent the occurrence of beading that the inks mix with each other and adhere on the transfer body.

Claims

The scope of the claims

[1] a recording head that discharges lipophilic ink;

A transfer body that receives the ejection of the ink by the recording head;

With

A plurality of lipophilic regions are formed on the transfer body, and a gap between the lipophilic regions is an oil repellent region.

[2] In the ink jet printer according to claim 1,

An ink jet printer, wherein the recording head has a plurality of ejection holes for ejecting the ink as droplets, and an interval between the ejection holes is at least twice an interval between the lipophilic regions.

[3] In the ink jet printer according to claim 1 or 2,

[4] The inkjet printer according to any one of claims 1 to 3, wherein each of the lipophilic regions is a concave portion.

[5] The inkjet printer according to any one of claims 1 to 4, wherein the transfer body has a belt shape.

[6] The inkjet printer according to any one of claims 1 to 4, wherein the transfer body has a drum shape.

[7] The inkjet printer according to any one of claims 1 to 6, wherein a transfer unit that transfers the ink landed on the transfer body to a recording medium, and an irradiation device that irradiates the recording medium with ultraviolet rays. When,

With

The ink is an ultraviolet curable ink that is cured by being irradiated with ultraviolet rays, wherein the ink is transferred from the transfer body to a recording medium by the transfer unit, and then receives an ultraviolet ray from the irradiation device. Printer.