JPH09323406A - Ink jet printer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent such troubles that a printing grade is lowered by the generation of strain in a printed image and a printing surface is contaminated. SOLUTION: A printer has a frame 26, the ink jet head 11 arranged in opposed relation to the frame 26 to form a printing part between the head and the frame, the printing paper deformation preventing means arranged on the downstream side of the printing part in the feed direction of printing paper 25 and preventing the deformation of the printing paper 25 by the flow of air and the printing piper discharge means arranged on the downstream side of the printing paper deformation preventing means in the feed direction of the printing paper 25 and holding the printing paper 25 from both surfaces thereof to discharge the same. The printing paper 25 is fed to the printing paper discharge means after printing but, during this period, the deformation of the printing paper 25 is prevented by the printing paper deformation preventing means. The leading end part of the printing paper can be prevented from the generation of bending or undulation.

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 Conventionally, in an ink jet printer, printing can be performed by ejecting ink droplets from an orifice of an ink jet head and adhering the ink droplets to a printing paper. 2 is a cross-sectional view of a main part of a conventional inkjet printer, and FIG. 3 is a perspective view of a main part of the conventional inkjet printer.

In the figure, reference numeral 11 denotes an ink jet head. The ink jet head 11 has an orifice plate (not shown) on its lower surface, and ink droplets are ejected from orifices formed in the orifice plate for printing. Reference numeral 12 denotes a carriage frame on which the inkjet head 11 is mounted. The carriage frame 12 is slidably supported along a shaft 13 and reciprocated by a spacing motor (not shown) (left and right in FIG. 3). Be moved in the direction).

Reference numeral 14 denotes an ink tank attached to the ink jet head 11, and ink not shown in the ink tank 14 is sent to the orifice through an ink flow passage not shown in the ink jet head 11. It is like this. Further, 16 is a sheet stacker that accommodates a plurality of printing sheets 25, and is urged toward the hopping roller 15 by the spring 17. Therefore, every time the hopping roller 15 is rotated once by a drive source (not shown), the printing paper 25 in the paper stacker 16 is separated and fed out one by one.

Pinch rollers 18, 19 are arranged between the sheet stacker 16 and the ink jet head 11, and the pinch roller 19 is pressed against the pinch roller 18 by a spring 20. Then, the pinch roller 18 receives rotation from a drive source (not shown), is rotated in the direction of the arrow together with the pinch roller 19, and sandwiches the print paper 25 fed by the hopping roller 15 and conveys it by contact friction, and the inkjet The sheet is sent to the printing unit formed between the head 11 and the frame 26. In the printing section, ink droplets are ejected from the orifice of the inkjet head 11, and the ink droplets are attached to the printing paper 25 for printing.

Further, a discharge roller 21 and a spur roller 22 are disposed downstream of the printing section in the conveying direction of the print sheet 25, and the discharge roller 21 is pressed against the spur roller 22 by a spring 23. Then, the discharge roller 21 and the spur roller 22 are rotated in the directions of the arrows, respectively, and discharge the print paper 25 conveyed by the pinch rollers 18 and 19 to the outside of the inkjet printer.

In this way, the printing paper 2 fed from the paper stacker 16 by the hopping roller 15
5 is sent to the printing section by the pinch rollers 18 and 19 and printing is performed by the inkjet head 11. Then, the printing paper 25 after printing is discharged to the outside of the inkjet printer by the discharge roller 21 and the spur roller 22.

[0008]

However, in the conventional ink jet printer described above, the printing paper 25 is used.
Is fed out by the hopping roller 15 and then conveyed to the printing section by the pinch rollers 18 and 19, and after the printing is performed, the discharge roller 21 and the spur roller 22.
However, if the print surface comes into contact with the spur roller 22 before the ink has dried sufficiently, the print surface becomes dirty.

Therefore, a sufficient distance is provided between the printing section and the discharge roller 21 and the spur roller 22. In this case, the printing paper 25 has the pinch rollers 18 and 1.
The pinch rollers 18 and 19 are conveyed to the printing section by 9 and reach the discharge roller 21 and the spur roller 22.
It is supported in a cantilevered manner and transported. Therefore, the conveyance state of the printing paper 25 becomes unstable, and the leading end portion of the printing paper 25 is bent (deflected) or waviness occurs.

As a result, the printed image is distorted and the printing quality is degraded. Further, after printing is performed in the printing section, the printing surface comes into contact with the orifice plate of the inkjet head 11 before the ink dries, and the printing surface becomes dirty.

The present invention solves the problems of the conventional ink jet printer described above, and provides an ink jet printer in which the printed image is not distorted, the print quality is not deteriorated, and the print surface is not contaminated. The purpose is to provide.

[0012]

Therefore, in the ink jet printer of the present invention, a frame, an ink jet head which is arranged so as to face the frame and forms a printing portion between the frame, and a printing paper are provided. A print sheet deformation preventing unit that is disposed downstream of the printing unit in the transport direction and that prevents the print sheet from being deformed by the air flow; and a downstream side of the print sheet deformation prevention unit in the transport direction of the print sheet. It has a printing paper discharge means that is disposed and discharges the printing paper by sandwiching it from both sides.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a sectional view of a main part of an inkjet printer according to an embodiment of the present invention, and FIG. 4 is a perspective view of a main part of an inkjet printer according to the embodiment of the present invention. In the drawing, 11 is an inkjet head, and the inkjet head 11
Has an orifice plate (not shown) on its lower surface, and ejects ink droplets from the orifices formed in the orifice plate for printing. Reference numeral 12 denotes a carriage frame on which the inkjet head 11 is mounted. The carriage frame 12 is slidably supported along a shaft 13 and reciprocates by a spacing motor (not shown) (moves in the horizontal direction in FIG. 4). ) Can be made.

Reference numeral 14 denotes an ink tank attached to the ink jet head 11. Ink (not shown) in the ink tank 14 is sent to the orifice through an ink flow passage (not shown) in the ink jet head 11. It is like this. Further, 16 is a sheet stacker that accommodates a plurality of printing sheets 25, and is urged toward the hopping roller 15 by the spring 17. Therefore, every time the hopping roller 15 is rotated once by a drive source (not shown), the printing paper 25 in the paper stacker 16 is separated and fed out one by one.

Pinch rollers 18, 19 are arranged between the paper stacker 16 and the ink jet head 11, and the pinch roller 19 is pressed against the pinch roller 18 by a spring 20. Then, the pinch roller 18 receives rotation from a drive source (not shown), is rotated in the direction of the arrow together with the pinch roller 19, and sandwiches the print paper 25 fed by the hopping roller 15 and conveys it by contact friction, and the inkjet The sheet is sent to the printing unit formed between the head 11 and the frame 26. In the printing section, the inkjet head 11
Ejects ink droplets from the orifice while reciprocating along the shaft 13 and ejects the ink droplets onto the printing paper 25.
It is attached to and printed.

Further, a discharge roller 21 and a spur roller 22 are disposed downstream of the printing portion in the conveying direction of the print sheet 25, and the discharge roller 21 is pressed against the spur roller 22 by a spring 23. Then, the discharge roller 21 and the spur roller 22 are rotated in the directions of the arrows, respectively, and discharge the print paper 25 conveyed by the pinch rollers 18 and 19 to the outside of the inkjet printer. The discharging roller 21 and the spur roller 22 constitute a printing paper discharging means.

By the way, the printing paper 25 is supported in a cantilever manner by the pinch rollers 18 and 19 and is conveyed in the carrying direction of the printing paper 25 so that the leading end of the printing paper 25 is not bent or undulated. A projection 35, which serves as a backflow prevention means and projects toward the inkjet head 11, is formed integrally with the frame 26 slightly downstream of the printing portion. The protrusion 35 extends in the width direction of the inkjet printer in parallel with the shaft 13 and supports the printing paper 25 from below.

An air outlet 34 is provided adjacent to the ink jet head 11 slightly downstream of the projection 35 in the conveying direction of the printing paper 25.
The air outlet 34 extends in the width direction of the inkjet printer in parallel with the shaft 13, and blows air toward the print sheet 25 by rotating the fan 30 to push the print sheet 25 from above from the projection 35 and the projection 35. Press on the downstream part. The fan 30 and the air outlet 34 constitute a printing paper deformation prevention unit.

Therefore, the leading end of the printing paper 25 is not only pinched from both sides by the projection 35 and the air blown out from the air outlet 34 immediately after passing through the printing section, but is also located on the downstream side of the projection 35. Since the printing paper 25 is pressed, it is possible to prevent the leading end of the printing paper 25 from bending, waviness, and the like. Further, since the front end portion of the printing paper 25 is curved by the projection 35, even if the front end portion of the printing paper 25 is deformed and warps or waviness occurs, the printing paper 25 is forcibly curved when it is bent. Be stretched to.

Therefore, the printed image is prevented from being distorted, and the print quality can be prevented from being degraded. Further, after the printing is performed in the printing unit, the printing surface and the orifice plate of the inkjet head 11 do not come into contact with each other before the ink dries, so that the printing surface can be prevented from being soiled.

The air blown out from the air outlet 34 accelerates the drying of the ink on the printing surface, so that the printing paper 25 after printing has the printing surface sufficiently dried. Discharge roller 21 and spur roller 22
Is discharged to the outside of the inkjet printer. Therefore, it is possible to further prevent the print surface from becoming dirty due to the contact between the print surface and the spur roller 22.

The air outlet 34 is used for the printing paper 2
5 is formed so as to be inclined toward the downstream side in the transport direction of 5, and air is blown out in a direction away from the printing unit. Therefore, the blown air does not flow backward to the upstream side, so that it is possible to prevent the leading edge of the print sheet 25 from being turned up and the print sheet 25 from floating.

Further, since it is possible to prevent the blown air from flowing into the printing portion and changing the trajectory of the ink droplets ejected from the orifice, the printing quality is not deteriorated. Since the projection 35 is arranged slightly upstream of the air outlet 34 in the transport direction of the printing paper 25, the air blown out from the air outlet 34 is prevented from flowing back to the upstream side. It can be prevented by the protrusion 35.

In this embodiment, the fan 30 is rotated to blow air toward the printing paper 25. However, an air suction hole (not shown) is formed in the frame 26 to rotate the fan (not shown). The air is sucked by making the printing paper 25 frame 26
It can also be pulled to the side. In this case, it is possible not only to prevent the front end portion of the printing paper 25 from being bent and waviness due to the suction of air, but also to generate an air flow with the suction of the air, so that the ink is dried by the air flow. Can be promoted.

The present invention is not limited to the above embodiment, but can be variously modified based on the gist of the present invention, and these are not excluded from the scope of the present invention.

[0026]

As described in detail above, according to the present invention, in an ink jet printer, a frame and an ink jet head which is arranged so as to face the frame and forms a printing portion between the frame and the ink jet head are provided. Disposed downstream of the printing unit in the transport direction of the printing paper,
A print sheet deformation preventing unit that prevents the print sheet from being deformed by the flow of air and a print unit that is disposed downstream of the print sheet deformation preventing unit in the conveyance direction of the print sheet and that sandwiches the print sheet from both sides and discharges it. And a sheet discharging means.

In this case, when the printing paper is printed,
The printing paper is sent from the printing section to the printing paper discharge means, and during that time, the printing paper is prevented from being deformed by the printing paper deformation preventing means. Therefore, it is possible to prevent the front end portion of the printing paper from bending, waviness and the like.

As a result, the printed image is not distorted and the printing quality is not deteriorated. Further, after the printing is performed in the printing unit, the printing surface does not come into contact with the orifice plate of the inkjet head before the ink dries, so that the printing surface is not contaminated.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a main part of an inkjet printer according to an embodiment of the present invention.

FIG. 2 is a cross-sectional view of a main part of a conventional inkjet printer.

FIG. 3 is a perspective view of a main part of a conventional inkjet printer.

FIG. 4 is a perspective view of a main part of the inkjet printer according to the embodiment of the present invention.

[Explanation of symbols]

 11 inkjet head 21 discharge roller 22 spur roller 25 printing paper 26 frame 30 fan 34 air outlet 35 protrusion

Claims (4)

[Claims] 1. An (a) frame, (b) an ink jet head which is arranged so as to face the frame and forms a printing portion between the frame and (c) the printing portion in the conveyance direction of printing paper. A print sheet deformation preventing unit which is arranged on the further downstream side and which prevents the print sheet from being deformed by the air flow; and (d) is arranged on the downstream side of the print sheet deformation preventing unit in the conveying direction of the print sheet. An inkjet printer, comprising: a print sheet discharging unit that sandwiches and discharges the print sheet from both sides. 2. The ink jet printer according to claim 1, wherein the printing paper deformation preventing unit includes an air outlet for blowing air toward the printing paper. 3. The ink jet printer according to claim 2, wherein the air outlet blows out air toward a downstream side in a print sheet conveyance direction. 4. The backflow prevention unit, which is provided between the printing unit and the air outlet, and which prevents the blown air from flowing back to the upstream side in the transport direction of the printing paper. Inkjet printer.