JP2738628B2 - Inkjet printer - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ink jet printer.

[0002]

2. Description of the Related Art In an ink jet printer which performs printing by ejecting ink droplets from a print head, a spur having a thin tooth is used as a pressing roller for pressing a paper to a paper discharging roller for discharging a printed paper. . This is because, in the above-described printer, the paper on which the ink cannot be completely dried may reach the paper discharge roller. Therefore, if the pressing roller is a normal cylindrical roller, the ink is applied to the peripheral surface of the roller from the printing surface of the paper. Is transferred to the sheet after one rotation of the roller, and the sheet becomes dirty.

FIG. 5 shows a conventional configuration of such an ink jet printer. In the figure, reference numeral 2 denotes a print head. The print head 2 is configured to move by a carrier (not shown) in a direction perpendicular to the plane of the paper in the figure and eject ink droplets onto the sheet fed to the printing unit C to perform printing.

[0004] Reference numeral 3 denotes a feed roller which is capable of feeding cassette paper and manual paper from the paper tray 6 to the printing unit C in cooperation with the leaf plate 4. Reference numeral 10A denotes a paper discharge device, which includes a paper discharge roller 11 capable of feeding and energizing paper (printed paper) printed by the print head 2 in a paper discharge direction (direction of arrow E), and a print surface of the printed paper. And a plurality of spurs 12 that come into contact with and press (press) the paper against the paper discharge roller 11.

More specifically, the paper discharge roller 11 is provided rotatably in the direction of the arrow downstream of the print head 2 in the paper transport direction. Each spur is rotatably provided on a spur holder 13 via a support shaft 12a, and is pressed against the discharge roller 11 by a spring 14 at a predetermined pressure. The spur holder 13 is positioned in the paper width direction (FIG. 5).
It extends long in the direction perpendicular to the sheet of paper, and is attached to the printer body (not shown) using appropriate fixing means.

[0006] Therefore, the printed paper is the paper discharge roller 1
The paper is sent in the paper discharge direction (E direction) by cooperation of the spur 1 and the spur 12, and is discharged to the paper receiving portion 19 with the printing surface up.

Normally, the spur holder 13 is provided with a plurality of cleaning rollers 15 which come into contact with each spur 12 and remove ink attached to the peripheral surface of the spur 12. Each cleaning roller 15 is rotatably supported by a spur holder 13 via a roller support shaft 16. The cleaning roller 15 includes a roller having a water absorbing sheet member such as blotting paper adhered to the outer peripheral surface thereof, and a roller made of urethane sponge material having a low foaming density.

[0008]

In the above-mentioned ink jet printer, if the contact pressure of the cleaning roller 15 with the spur 12 is too weak, the ink adhering to the spur 12 cannot be effectively removed. Is too strong, the rotational resistance of the spur 12 may increase, and the spur 12 and the paper discharge roller 11 may not be able to smoothly feed the printed paper in the paper discharge direction and urge it. Therefore, it is necessary to adjust the contact pressure of the cleaning roller 15 with respect to the spur 12 so that the ink adhered to the spur 12 can be effectively removed while ensuring smooth paper ejection. Spur 1
2, the ink cannot be completely removed, and the ink may be re-transferred from the spurs 12 to the printing surface of the printed paper and stained. In particular, immediately after performing high-density printing,
The ink stain is likely to occur.

In view of the above circumstances, an object of the present invention is to provide an ink jet printer capable of completely removing ink from spurs and preventing retransfer to printed paper.

[0010]

SUMMARY OF THE INVENTION The present invention is based on an empirical rule that the ink adhered to a spur cannot be completely removed even if the contact pressure of the cleaning member to the spur is adjusted optimally. The present invention was conceived in view of an internal improvement, that is, a need to review the material itself of the cleaning member.

It has been found from the past use results that water-absorbing sheet members such as blotting paper have problems from the viewpoints of durability and ease of handling. An experiment was performed on a sponge material.

Here, as the urethane sponge material, a urethane elastomer sponge ET material manufactured by Bridgestone Chemical Co., Ltd. having a high foaming density (200 foaming density / 25 m
m or more) and the company's PH-20 with a relatively low foaming density.
(70 foam density / 25 mm) and melamine foam sold by INOAC CORPORATION. In addition,
A foaming density of 200 pieces / 25 mm means a length of 25 mm (1
This indicates that the number of cells of the original material per inch (equivalent to inches) is 200 (the same applies hereinafter).

As an experimental method, a cleaning roller made of each material is mounted on a spur holder, and when a print head discharges paper in which the first half is printed with high density and the latter half is made non-printed, a non-printed portion (particularly, high density) is discharged. The portion immediately after printing) was visually observed to determine whether or not there was ink retransfer from the spur. The experimental results are shown in FIGS. 4 (A), (B) and (C). Here, (A) is a printed sheet when a cleaning roller made of a urethane elastomer sponge ET material is used,
(B) is a printed sheet when a cleaning roller made of PH-20 is used, and (C) is a printed sheet when a cleaning roller made of melamine foam is used.

As is clear from the visual observation, a urethane elastomer sponge ET material having a high foaming density [FIG.
(A)] No re-transfer of ink was observed in the used ink. For those made of PH-20, ink retransfer [Fig.
(See (d) in (B)). In the case of the melamine foam, retransfer of the ink (see d in FIG. 4C) is scarcely recognized, but it is considered to be unsuitable for practical use because it comes off quickly due to contact with the peripheral surface of the spur. The present invention has been made based on the above experimental results and the like.

That is, the ink jet printer according to the present invention contacts the printing surface of the paper printed by the print head, presses the paper against the paper discharge roller, and feeds the paper in the paper discharge direction in cooperation with the paper discharge roller. An ink jet printer comprising a possible spur and a cleaning member for removing ink attached to the spur in contact with the spur, wherein the cleaning member has a foaming density of 200 to 350 pieces / 2.
It is characterized by being formed from a urethane sponge material of 5 mm.

[0016]

According to the present invention having the above-described structure, the paper (printed paper) printed by the print head is pressed against the paper discharge roller which is rotated in a predetermined direction by pushing the printing surface by a spur. As a result, the printed paper is frictionally engaged with the paper discharge roller and fed and urged in the paper discharge direction by the rotational force of the roller. At this time, the spur comes into contact with the printing surface of the printed paper, so that the ink adheres thereto. The ink adhering to the spur is completely removed by a urethane sponge cleaning member having a high foaming density of 200 to 350 cells / 25 mm. Is done. Therefore, retransfer of the ink from the spur onto the printed paper can be prevented.

[0017]

Embodiments of the present invention will be described below with reference to the drawings. The basic configuration of this ink jet printer is the same as that of the conventional example (FIG. 5), and the cleaning member (the plurality of cleaning rollers 15) has a foaming density of 200 to 350.
Spurs 1 formed from urethane sponge material of 25 pieces per piece
2, so that the ink adhering to No. 2 can be completely removed. Note that the same components as those in the conventional example (FIG. 5) are denoted by the same reference numerals, and description thereof will be simplified or omitted.

Here, in this ink jet printer,
From the results of various experiments, the cleaning roller 15 as a cleaning member was formed from a urethane elastomer sponge ET material (manufactured by Bridgestone Chemical Co., Ltd.) having a foaming density of 200/25 mm or more. Such a urethane elastomer sponge ET material is a kind of urethane sponge material, and is excellent in water absorption, moldability, durability, and easy handling, and is optimal as a cleaning member.

In this embodiment, the cleaning roller 15
As shown in FIGS. 2 and 3, the thickness t is 4 mm and the outer diameter is 12 m in consideration of economy, compatibility with the width of the spur 12, and the like.
m, urethane elastomer sponge E having an inner diameter of 2.0 mm
Two T materials are formed in parallel.

A roller support shaft for rotatably supporting the cleaning roller 15 is divided so that each cleaning roller 15 can rotate independently. Each of the divided roller support shafts (16a) is rotatably supported by the second bearing portion 25 of the spur holder 13 such that the cleaning roller 15 can follow the spurs 12 while maintaining a state of being in contact with the spurs 12. More specifically, each roller support shaft (16
a) is formed of a stainless steel round bar having a diameter of 2.5 mm and a length of 16 mm, and is press-fitted into the inner diameter portions of two urethane elastomer sponge ET materials.

The support shaft 12a for rotatably supporting each spur 12 is also divided so that each spur 12 can rotate independently. Each divided support shaft (12a ')
The spurs 12 are rotatably supported by the first bearing portion 22 of the spur holder 13 such that each spur 12 comes into contact with the paper discharge roller 11 at a predetermined pressure by its own weight.

Next, the operation will be described. The paper (printed paper) P printed by the print head is pressed against the paper discharge roller 11 which is rotated clockwise in FIG. As a result, the printed paper P is frictionally engaged with the paper discharge roller 11 and is fed and urged in the paper discharge direction by the rotational force of the roller 11. At this time, spur 1
In No. 2, the ink adheres because it comes into contact with the printing surface of the printed paper P, but the ink adhering to the spur 12 is completely removed by a urethane sponge cleaning member having a foaming density of 200 to 350/25 mm. . Therefore, retransfer of the ink from the spur 12 to the printed paper P can be prevented.

According to this embodiment, the cleaning member is made of a urethane sponge material having a foaming density of 200/25 mm or more (urethane elastomer sponge ET material).
Since the cleaning roller 15 is formed by each of the cleaning rollers 15, it is possible to completely remove the ink from the spurs 12 and prevent re-transfer of the ink to the printed paper P.

In the above embodiment, the cleaning member is formed of a urethane elastomer sponge ET material having a foaming density of 200 pieces / 25 mm or more. However, the cleaning member is formed of a urethane sponge material having a foaming density of 200 to 350 pieces / 25 mm. It may be formed.

[0025]

According to the present invention, since the cleaning member is formed of a urethane sponge material having a foaming density of 200 to 350 cells / 25 mm, the ink is completely removed from the spurs and the ink is retransferred to the printed paper. Can be prevented.

[Brief description of the drawings]

FIG. 1 is a diagram for explaining a main part of an embodiment of the present invention.

FIG. 2 is an external perspective view of a cleaning roller.

FIG. 3 is a view for explaining a positional relationship between a cleaning roller and a spur.

FIG. 4 is a diagram illustrating a result of an experiment for selecting a material of a cleaning roller.

FIG. 5 is a diagram for explaining a schematic configuration of a conventional inkjet printer.

[Explanation of symbols]

 11 paper discharge roller 12 spur 15 cleaning roller (cleaning member)

Claims (1)

(57) [Claims] 1. A spur capable of contacting a printing surface of a sheet printed by a print head, pressing the sheet against a sheet discharging roller, and cooperating with the sheet discharging roller to feed the sheet in a sheet discharging direction. An ink jet printer comprising: a cleaning member that removes ink adhering to the spur in contact with the spur;
An ink jet printer formed of a 25 mm urethane sponge material.