JPH11268857A - Paper lift preventing mechanism for ink jet printer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent paper from lifting up from a paper guide due to cockle formed by inking when a part recorded by the inking in the paper is fed on the paper guide in an ejecting direction straight and is bent downward at a position off the paper guide. SOLUTION: A plurality of ribs 18, 20 are disposed in parallel at prescribed intervals on a paper guide 6, and a recording medium 8 which comes into contact with the ribs 18, 20 is bent to a regular shape when a cockle occurs, so that lifting up of the recording medium 8 is inhibited at a printing part. The paper guide 6 is provided with a protrusion 22 placed on the downstream side of the ribs 18, 20 and applies a reversed warping to the recording medium 8, thus lift-up of the recording medium 8 can be prevented when the recording medium 8 is bent downward at a position of the paper guide 6 by a reversed warping phenomenon of the recording medium 8.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a paper floating preventing mechanism in an ink jet type plotter (printer).

[0002]

2. Description of the Related Art Ink jet type plotter (printer)
In order to prevent the print medium from rising from the platen due to wavy wrinkles (cockles) generated by ink adhesion during printing, a rib is provided in the print area of the platen (paper guide) to prevent uncontrolled bending of the print medium. A technique for reducing the occurrence is disclosed in JP-A-7-256555. In addition to the paper feed roller, an ink jet type plotter provided with a spur roller for holding the paper in the paper discharge direction in order to prevent the paper, that is, the recording medium from floating in the printing area, is disclosed in Japanese Patent Application Laid-Open No. H9-1997.
No. 48161 discloses this. In addition, a small-sized inkjet printer having a tray for guiding printed paper straight has been conventionally known.

[0003]

In an ink-jet type plotter (printer), when a face is drawn on a sheet, the sheet absorbs ink and the sheet is bent (cockle). When this cockle occurs, the paper is stiffened, so the printed portion of the paper tends to come straight out in the direction of extension of the platen. However, the sheet is broken by its own weight when it is off the support surface of the platen. When the paper is folded, the paper rises from the platen due to cockle, and there is a problem that a printing screen is stained by a recording head or, in the worst case, a jam (paper jam) occurs. As a countermeasure against this problem, it is conceivable to lengthen the platen or to provide a mechanism such as a tray for guiding the paper straight, but the plotter becomes large and the cost increases. Further, it is conceivable to provide a spur on the paper discharge direction side in order to prevent the paper from floating. An object of the present invention is to solve the above problems.

[0004]

SUMMARY OF THE INVENTION In order to achieve the above object, according to the present invention, a plurality of ribs arranged in parallel at predetermined intervals on a paper guide are used to form a curved recording medium in a regular shape, thereby recording in a printing section. In a paper floating prevention mechanism of an ink jet printer which prevents floating of a medium, a paper guide is provided with a convex body which is positioned downstream of the rib to give a reverse-warped state to a recorded recording medium. It is.

[0005]

Embodiments of the present invention will be described below in detail with reference to the accompanying drawings. In FIG.
(2) is a main body of a large-sized inkjet printer,
A rear paper guide (4) and a front paper guide (6) are provided, and are supported by legs (not shown). The paper guides (4) and (6) have a width wider than the width of the paper (8) (recording medium) having the largest dimension, and their opposing portions extend in a direction perpendicular to the paper surface in FIG. A drive roller (10) is disposed, and the drive roller (10)
It is fixed to a drive shaft (12) connected to the motor.
Reference numeral (14) denotes a pressure roller which is disposed on the same axis so as to be capable of coming into contact with and separating from the drive roller (10) and rotatable. The pressure roller (14) and the drive roller (10) Constitutes a pinch roller mechanism for nipping and conveying the sheet (8) in a predetermined direction.

The paper guides (4) and (6) are respectively composed of an upper horizontal portion (4a) (6a) and a curved guide portion (4).
b) and (6b). The upper horizontal portion (4a) of the rear paper guide (4) and the curved guide portion (4)
b) forms a recording medium supply guide path for guiding a recording medium (8) such as paper to a printing unit, and includes an upper horizontal portion (6a) and a curved guide portion (6b) of the front paper guide (6).
Constitutes a recording medium discharge guide path (7). An intake hole (not shown) is formed in the drawing plate portion (6c) of the upper horizontal portion (6a) of the front paper guide (6) and in the vicinity thereof, and is arranged below the drawing plate portion (6c). The suction device (not shown) generates suction force on the surface of the drawing plate portion (6c) and a predetermined range near the drawing plate portion (6c).

Reference numeral (16) denotes an ink jet type recording head which has a predetermined gap between the drawing plate (6c) and the drawing plate (6c).
It is attached to a Y-axis guide rail (not shown) so as to reciprocate along the Y-axis. The drawing plate (6
In (c), elongated ribs (18) are fixedly arranged in parallel with a predetermined gap therebetween to prevent the paper from floating. Also, on the downstream side of the drawing plate section (6c), elongated ribs (20) are fixedly arranged in parallel with the ribs (18) at predetermined intervals to prevent the paper from floating. ing.

At the end of the upper horizontal portion (6a) of the front paper guide (6), a plurality of protrusions (22) for imparting a reverse warp to the sheet (8) on the recording medium discharge guide path (7). )
Are located on the X-axis direction arrangement line of the ribs (18) and (20) and are fixedly arranged in parallel. Next, the operation of the present embodiment will be described. When the print recording operation is started, a recording medium (8) such as a roll paper drawer or cut paper placed on a rear paper guide (4) is driven by a driving roller (10) and a pressure roller (14). The sheet is conveyed in the direction of the arrow while receiving the vacuum force downward on the drawing plate portion (6c) by the intermittent rotation of the drive roller (10) in the counterclockwise direction in FIG.

The recording head (16) reciprocates in the Y-axis direction on the recording medium (8), and draws a drawing plate (6c).
The information is recorded on the recording medium (8). At this time, the ink ejected from the recording head (16) causes cockle (wrinkles) in the ink-coated portion of the recording medium (8).
The cockle is regularly controlled by the ribs (18) and (20), and the ribs (18) and (20) prevent the recording medium (8) from rising from the paper guide (6).

The recording medium (8) after printing has a rib (20)
A reverse warp is formed between the protrusion and the protrusion (22). Furthermore,
After printing, the recording medium (8) attempts to move in the horizontal extension direction from the upper horizontal portion (6a) of the paper guide (6), but when it comes off the upper horizontal portion (6a), the recording medium (8) loses its own weight. And is guided by the bow guide (6b),
It is transported downward. At this time, even if the recording medium (8) is broken, the influence of the paper folding is not transmitted to the printing portion of the recording medium (8) due to the reverse warp state of the recording medium (8). (6) Close contact. Therefore, even if the recording medium (8) is broken, the recording medium (8) does not rise from the paper guide (6) in the printing section.

As shown in FIG. 4 (4), instead of fixing the protruding body (22) to the paper guide (6), the paper guide (6) is formed by a sheet metal working on the protruding body (22). ) May be integrally formed. or,
Similarly, the ribs (18) and (20) are paper guides (6).
May be integrally formed with a sheet metal.

[0012]

Since the present invention is constructed as described above, it is possible to prevent paper floating due to cockle without increasing the size of the paper guide on the recording medium discharge side, and to reduce the occurrence of jam with an inexpensive structure. There are effects such as prevention.

[Brief description of the drawings]

FIG. 1 is an external view of a part of an ink jet printer.

FIG. 2 is a side sectional view of the ink jet printer.

FIG. 3 is an explanatory side view showing another embodiment of the ink jet printer.

FIG. 4 is an external view illustrating another embodiment of the ink jet printer.

[Explanation of symbols]

 2 Printer body 4 Paper guide 6 Paper guide 8 Paper (recording medium) 10 Drive roller 12 Drive shaft 14 Pressure roller 16 Recording head 18 Rib 20 Rib 6a Upper horizontal section 6b Curved guide section 6c Drawing plate section 4a Upper horizontal section 4b Curved guide section 7 Recording medium discharge guide path 22 Projected body 22 'Projected body

Claims (1)

[Claims] An ink-jet printer in which a plurality of ribs arranged in parallel on a paper guide at predetermined intervals makes the recording medium bend in a regular shape to prevent the recording medium from floating in a printing section. A mechanism for preventing paper floating of an ink jet printer, wherein a protrusion is provided on the paper guide on the downstream side of the rib to impart a reverse warp state to a recorded recording medium.