JPH10146956A - Ink-jet recording apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent a paper from being hurt by a delivery roller for removing the paper after the end of printing and the recording surface of the paper from being stained by retransfer caused by the sticking of undried and unfixed ink to the roller. SOLUTION: A delivery roller 10 for transporting paper in the delivery direction after the end of the printing of recording data by a print head in collaboration with a carry-out roller is supported freely rotatably by a support member, contacts the paper traveling by the rotation of the carry-out roller, and is rotated by the friction. Pyramidal projections 14 are formed which are arranged spirally in the direction crossing the rotary axis of the delivery roller 10 along the circumference of the roller main body 11 of the roller 10 which contacts the paper. Accordingly, the tops of the pyramids point-contact the surface of the paper continuously corresponding to the number of the projection 14 arranged spirally.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ink jet recording apparatus, and more particularly, to an ink jet recording apparatus provided with a discharge roller for discharging a sheet after printing.

[0002]

2. Description of the Related Art Conventionally, in an ink jet recording apparatus, after a record is printed on a sheet of paper, the ink is in contact with a discharge roller before the ink is dried and fixed, so that the unfixed ink adheres to the surface of the discharge roller. May be. In such a case, the unfixed ink is re-transferred from the paper discharge roller to the surface of the printed paper, and remains as a linear streak on the precious recording surface, thus causing a problem.

As a technique for solving such a problem, for example, Japanese Patent Laid-Open No. 6-6481 proposed by the applicant of the present invention has been proposed.
There is a paper discharge mechanism described in Japanese Patent Application Publication No. 0-205. In this case, a paper discharge roller is disposed on the back side of the paper, and a belt is disposed on the front side of the paper at a position facing the discharge roller. A protrusion is provided on the surface of the belt. The belt is wound between a pair of first belt rollers and a second belt roller.

[0004] The sheet discharging mechanism can prevent stains due to retransfer of ink to the recording surface of the sheet and stains due to dragging.

[0005]

The paper discharge mechanism described in this publication is effective for preventing contamination and the like due to ink retransfer. However, since the projection is provided on the surface of the belt, the paper discharge mechanism is not used. There are still problems to be solved, such as leaving scars on the surface.

Accordingly, it is an object of the present invention to provide a paper discharge roller that discharges paper after printing without leaving a scar on the paper, and that undried and unfixed ink adheres to the paper discharge roller to be retransferred. To provide an improved ink jet recording apparatus so as not to contaminate the paper recording surface.

[0007]

An ink jet recording apparatus according to the present invention comprises a paper discharge roller for transporting paper after printing of print data by a print head in cooperation with a discharge roller in a paper discharge direction, The paper discharge roller is rotatably supported by a support member, and comes into contact with the paper moving and running by the rotation drive of the carry-out roller, and rotates by its frictional force. Along the peripheral surface of the discharge roller, a projection is provided spirally extending in a direction intersecting the roller rotation axis.

In this case, the projections may be provided at equal intervals on the upper surface of a spiral strip having a convex cross section provided along the peripheral surface of the paper discharge roller, or may be formed as a pyramid projection or a pyramid projection. Conical projections are also possible.

With this configuration, the paper discharge roller rotating in contact with the paper makes continuous point contact with the surface of the paper at the top of the pyramid by the number of the pyramid projections spirally connected. Therefore, no scar is left on the sheet. Even if the recorded printing ink is undried and unfixed, it is almost never re-transferred to the printing surface of the paper through the pyramidal projections connected by point contact.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an ink jet recording apparatus according to an embodiment of the present invention will be described in detail with reference to the drawings.

As schematically shown in FIG. 1, the ink jet recording apparatus of the present embodiment has a print head 1 for printing by jetting ink onto the surface of a sheet 9 and printing the sheet. A sheet feeder 2 that feeds paper toward a suitable position of the print head 1 is arranged. On the exit side of the sheet feeder 2, a pair of upper and lower feed rollers 3, 4 as shown in the drawing, which sandwiches and feeds the sheet 9 from both front and back sides thereof, are arranged. Of the pair of feed rollers 3, 4, rotation from a drive source (not shown) is transmitted to the lower feed roller 3, and the upper feed roller 4 presses the sheet 9 against the lower feed roller 3. Functions as a roller. A paper guide 5 for guiding the paper 9 sent out by the pair of feed rollers 3 and 4 to a position corresponding to the print head 1 is provided.

Further, after printing on the paper 9 by the print head 1, a pair of upper and lower discharge rollers 6 and a paper discharge roller 10 for transporting the paper 9 from above and below to a discharge port (not shown) are arranged. The discharge roller 10 is rotatably supported at both ends in the axial direction by a roller supporter 7.
The unloading roller 6 shown in FIG. 4 is connected to a drive source (not shown) so that rotation at a predetermined gear ratio is transmitted.

FIGS. 2 and 3 show a front view and a side view of the discharge roller 10 described above. FIG. 4 shows the discharge roller 10 provided in the axial direction of the discharge roller 6. It shows a front view.

The discharge roller 10 is a roller body 1 which is cylindrical or cylindrical and formed as long as possible in the direction of the rotation axis.
A rotating shaft 12 rotatably supported by a roller supporter 7 at both longitudinal ends of the roller body 11;
12 are protruding. A spiral ridge 13 having a convex cross section is formed along the peripheral surface of the main body 11.
The pyramid projections 14 are continuously provided on the upper surface of the spiral on the basis of 3.

Next, the operation and operation of the ink jet recording apparatus of the present embodiment having the above configuration will be described with reference to the drawings.

When the sheet 9 is fed from the sheet feeder 2 by starting the apparatus, the sheet 9 is sent onto the sheet guide 5 by the pair of feed rollers 3 and 4. Here, print data output from an electronic document creation device such as a word processor, which is a higher-order device, is printed on a sheet 9 by the print head 1.

When printing on the paper 9 is completed, the printed paper 9 is discharged to a paper discharge port by a pair of upper and lower discharge rollers 6 and a discharge roller 10.

At this time, the printed paper 9 is transferred to the discharge roller 6
The paper discharge roller 10 is only rotatably supported by the roller supporter 7, and is rotated by the frictional force that comes in contact with the paper 9 when the paper 9 is transported.

A paper discharge roller 10 that rotates in contact with the paper 9
In this case, the number of pyramid protrusions 14 spirally connected to the printed surface of the paper 9 makes continuous point contact at the pyramid apex. Even if the printing ink recorded on the surface of the paper 9 is undried and unfixed, it is almost never retransferred to the printing surface of the paper 9 through the pyramidal projections 14 connected by point contact.

It is assumed that unfixed ink adheres to the spiral pyramid projections 14 and is retransferred to the recording surface of the printed paper 9. Even in such a case, the pyramid projections 14
The recording surface of the reprinting is hardly noticeable because the reprinted recording traces due to the retransfer are dispersed in the oblique direction. That is, the inconvenience that the reprint recording trace remains in a straight line and is conspicuous as in the related art is solved.

Further, since the pyramid projection 14 contacts the paper 9 only at the apex of the pyramid and in a spiral oblique direction, almost no contact scar is left on the surface of the paper 9 being printed in a straight line in the running direction. . Even if some traces of contact remain, they are dispersed in a spiral diagonal direction.
Almost inconspicuous on the recording surface.

In this embodiment, the discharge rollers 10
The configuration in which the pyramid projections 14 that are connected in a spiral shape are provided has been described. However, a conical projection instead of the pyramid projection 14 or a sharp projection instead of the pyramid projection 14 may be used as long as the paper 9 does not break or scratch the contacting paper 9.

[0023]

As described above, in the ink jet recording apparatus according to the present invention, the paper discharge roller for discharging the paper after printing is continuously brought into contact with the paper by the point contact method. The problem of leaving scratches on the paper is eliminated. In addition, the problem that the printing ink after being recorded on the paper adheres to the surface of the paper discharge roller without being dried and unfixed as in the related art, and is retransferred straight to the recording surface of the paper to leave conspicuous stains, is also solved. And a high quality printing surface can be obtained.

[Brief description of the drawings]

FIG. 1 is a configuration diagram schematically showing an inkjet recording apparatus according to an embodiment of the present invention.

FIG. 2 is a front view showing a discharge roller which is a main part of the embodiment.

FIG. 3 is a side view of a paper discharge roller.

FIG. 4 is a front view of an assembly with a plurality of discharge rollers arranged in the axial direction of a discharge roller.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Print head 2 Sheet feeder 3 Driving side feed roller 4 Feed roller as a press roller 5 Paper guide 6 Unloading roller 7 Roller supporter 10 Discharge roller 11 Roller body 12 Rotary shaft 13 Spiral ridge 14 Pyramid projection

Claims (5)

[Claims] An output roller configured to convey a sheet after recording data has been printed by a print head in a discharge direction in cooperation with an output roller, the discharge roller being rotatable by a support member; In the ink jet recording apparatus, which is supported and comes into contact with the paper moving and running by the rotation drive of the carry-out roller, and is rotated by the frictional force, along the peripheral surface of the paper discharge roller contacting the paper, An ink jet recording apparatus, comprising: a projection spirally extending in a direction intersecting a roller rotation axis. 2. The discharge roller according to claim 1, wherein the discharge roller is formed to be long in the direction of the rotation axis, and the spiral protrusion is provided along a peripheral surface substantially the full length. 2. The ink jet recording apparatus according to 1. 3. The ink-jet apparatus according to claim 1, wherein the projections are arranged at equal intervals on an upper surface of a spiral strip having a convex cross section provided along a peripheral surface of the paper discharge roller. Recording device. 4. An ink jet recording apparatus according to claim 1, wherein said projection is a pyramidal projection. 5. An ink jet recording apparatus according to claim 1, wherein said projection is a conical projection.