JP3250570B2 - Paper discharging method and apparatus in ink jet printer - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for discharging paper in an ink jet printer.

[0002]

2. Description of the Related Art In an ink-jet printer of the type in which ink droplets are ejected onto a surface of a sheet to perform printing, when printing is continuously performed on a plurality of sheets, the next sheet ejected before the ink has dried does not come forward. On the printing paper, and comes into contact with the printing surface, and this surface is soiled.

To solve such a problem, Japanese Patent Laid-Open Publication No.
In the apparatus disclosed in Japanese Patent Application Publication No. 865, the paper discharge tray is formed as a concave member extending in a direction parallel to the paper discharge direction, and the discharged paper is laminated on the concave surface and bent in a concave shape. This causes a slight time delay before contacting the next ejected sheet, or forcibly hits the incoming sheet with a wave parallel to the ejection direction. By discharging the paper directly, the time for contact with the previous sheet is delayed, thereby preventing the printing surface from being stained due to the contact.

[0004] However, even if a paper discharge tray as in the former case is used, paper with strong stiffness is not necessarily laminated in a gutter-like concave state, so that there is no time delay in contact between the papers. In addition, in the latter method of waving the paper itself, the influence extends to the printing section,
Another problem arises, such as loss of print quality.

[0005]

SUMMARY OF THE INVENTION The present invention has been made in view of such a problem.
It is an object of the present invention to provide a new paper discharging method and a new paper discharging method capable of effectively preventing a stain on a printing surface by effectively delaying a contact time with a previous paper regardless of a paper to be used. .

[0006]

That is, the present invention provides a method of discharging paper in an ink-jet printer for achieving the above object, in which a paper after a printing process is sent out while holding the paper flat, and then the paper is conveyed. The sheet is pressed by the leading edge of the following sheet while being concaved in a
Pressure is intended and to discharge to the step lower sheet discharge portion, also a paper to be followed by the other party of the paper abuts stage
It is intended to be temporarily stopped, and furthermore
Is a paper discharge device that is supported on both sides
Provided upper edge sloping gradually toward the hand side
Or use gutter-shaped concave means to support both sides of the paper
Press down on both sides of the rib-shaped support section and the center of the paper in the width direction
And a push-down knurled roller
The beveled roller can be displaced to the fixed member via the arm
Pivot or displace the push-down jagged roller by its own weight
It is something to do.

[0007]

Embodiments of the present invention will be described below. Each of the drawings shows a sheet discharging apparatus according to an embodiment of the present invention applied to an ink jet printer.

First, the entire structure of an ink jet printer to which this apparatus is applied will be described with reference to FIG. 3. A paper feed roller 30 and a paper feed roller 30 are provided in a paper feed path 20 from a paper feed section 10 to a print section 60. A gate roller 40 and a pinch roller 50 that are pressed against the feed roller 30 and rolled are provided, and a discharge path 7 from the printing unit 60 to the discharge tray 100.
0, a conveying roller 81 and a conveying notch roller 82 to be described later.
And a discharge unit 90 provided with a press-down knurled roller 92 for pressing down the central portion of the sheet downward, and printing has been performed on a discharge tray 100 disposed at a position one step lower than the discharge unit 90. Is configured to be discharged.

The above-mentioned paper feeding unit 10 contacts a central portion of the stacker provided on the bottom 11a of the lower case 11 of the printer and the uppermost paper p stacked and mounted on the stacker, and feeds this to the paper feeding path 20. The paper feed roller 12 is further fixed to one end and the other end of a gear train 210 and a paper feed shaft 31 from a paper feed motor 200 as shown in FIG. Gears 32, 33,
It is driven via a sun gear 13, a planetary gear 14, and a gear 15 fixed to a paper feed roller shaft 16, and receives a driving force from a planetary gear 14 which meshes with the gear 15 only when the carriage comes to a paper feed position. It is configured to rotate.

On the other hand, while the paper feed roller 12 is rotating, the paper feed roller 30 disposed in the paper feed path 20 rotates in a direction opposite to the paper feed direction, and the paper p fed by the paper feed roller 12 is rotated. The skew is removed by blocking the leading end of the printing unit 60 from the gate roller 40, and the printing unit 60 is
It is configured to feed to.

On the other hand, an ink jet recording head 62
Is configured to run with a slight gap between the guide shaft 63 and the upper surface of the intermediate frame 110 while being carried by the carriage 61 which is guided by the upper frame 120 and reciprocates in the paper width direction.

On the other hand, a paper discharge section 80 located on the upper side in the paper conveyance direction of the paper discharge path 70 is provided with a conveyance roller 81 and a conveyance claw roller 82 which are opposed to each other. While maintaining p flat, the recording head 62
From the paper tray 100.

As shown in FIGS. 1 and 4, three transport rollers 81 are attached to the two left and right rotary shafts 83 and 84 supported by the intermediate frame 110, respectively. The six conveying gear rollers 82a to 82f arranged corresponding to the three shafts 81a to 81f
6 are attached to each of them. As shown in FIG. 7, the three shafts 86 are supported by vertically long holes 122 of a support portion 121 bent from the upper frame 120 in a direction parallel to the paper conveyance direction. The transport gear roller 82 supported by a spring 87 locked to the tongue piece 123 of the motor 120 is urged to press against the peripheral surface of the transport roller 81, and further, a nip portion where the transport roller 81 and the transport gear roller 82 come into contact with each other. As shown in FIG. 9, the paper p is supported by the printing unit 60 while slightly floating above the upper surface of the intermediate frame 110.

The transport roller 81 includes rotating shafts 83 and 84.
The paper p is rotated based on the number of pulses of the paper feed motor 200 so as to be driven and rotated by the paper feed roller 30 only when the paper feed roller 30 rotates forward via the conveyance roller gears 83a and 84a fixed to the paper p. When the leading end protrudes from the transport roller 81, the drive is performed with a program for temporarily stopping the rotation.

That is, the rotating shaft 83 of the transport roller 81,
The conveying roller gears 83a and 84a fixed to the roller 84 are connected to the shaft 85 of a roller 85b that rolls in contact with the paper feed roller 30.
c with the transmission gear 85a fixed to the paper feed roller 3
0, the shaft 85c is configured to receive a rotational driving force, and both ends of the shaft 85c are supported by a vertically elongated rectangular hole 111 provided in the intermediate frame 110 so as to be displaceable as shown in FIG. When the feed roller 30 rotates in the normal rotation direction, that is, in the paper feed direction, it is displaced downward in the figure to mesh with the transport roller gears 83a and 84a, and the paper feed roller 30 rotates in the reverse rotation direction, that is, the direction of the arrow in FIG. When the paper feed roller rotates in the direction opposite to the paper feed direction, the paper feed roller 30 is displaced upward in the drawing to be separated from the peripheral surface of the paper feed roller 30 so that rotation from the roller 30 is not transmitted.

On the other hand, a discharge unit 90 located on the lower side of the transport unit 80 in the paper transport direction is a paper discharge device in which the paper p is recessed in a gutter shape in a direction parallel to the paper transport direction and is disposed one step lower. The discharge portion 90 is a portion that is discharged to the tray 100. The discharge portion 90 includes two side supporting portions 91, 91 that support both sides of the sheet p from below, and a push-down that pushes down the widthwise central portion of the sheet p from above. It is constituted by a toothed roller 92.

As shown in FIGS. 1 and 9, the both-side supporting portions 91 are located at positions coincident with the conveyed jaw rollers 82a and 82f located on both sides of the conveyed jaw rollers 82, and are located below the conveying rollers 81 in the paper conveying direction. The upper edge is formed integrally with the intermediate frame 110 so as to be located on the side, and the upper edge thereof is formed as an inclined edge that becomes gradually higher in the paper transport direction.

On the other hand, as shown in FIG. 9, the press-down knurled roller 92 is attached to the upper frame 120 so that the peripheral edge thereof is located slightly below the upper edge of the support plate 91 on both sides.
It is mounted so that it can be moved up and down through the.

As shown in FIG. 10, the arm 93 has a bifurcated portion extending upward in the paper transport direction.
Further, stoppers 93b and 93c are formed at the ends thereof so as to protrude outward with a gap therebetween.
By inserting the ends of these arms 93 into window holes 123 formed in the corners of the portions bent and formed into a crank shape, the press-down knurled rollers 93 located on the lower side of the stoppers 93b and 93c in the paper transport direction are formed. The paper p is pivotally supported so as to be able to bend vertically by its own weight so that the widthwise central portion of the paper p can be bent downward.

Next, a description will be given of a method of discharging a sheet by the apparatus having the above-described configuration. A paper feed roller 30 fed by the paper feed roller 12 and rotating in the anti-paper feed direction
When the paper p skewed between the paper feed roller 30 and the driven roller 20 comes from the paper feed roller 30 to the feed roller 81, the feed roller 81 whose peripheral speed is set to be about 12% faster than the paper feed roller 30 becomes , To which a tension is applied to the printing unit 6
While the paper p is kept flat at 0, the required recording and writing is performed on the printing surface by slightly lifting it from the upper surface of the intermediate frame 110.

Then, the number of pulses of the paper feed motor 200 becomes a preset value, and the leading end of the paper p is
When the paper is fed to a position slightly protruding from 1, the rotation of the paper feed motor is temporarily stopped.

By the way, in this state, the paper p which has been subjected to the printing process immediately before that and sent to the discharge section 90 by the transport roller 81 is, as shown in FIG. Both sides are supported by both sides 9
The central part in the width direction is pushed down by the jagged roller 92 while being supported by 1, 91, and is stopped by being formed in a gutter shape in the paper conveying direction.

For this reason, if the sheet p2 subsequently sent under this state keeps a flat state and stops against the rear end pb of the sheet p before being bent into a gutter shape, As shown in FIG. 14, the sheet p before being extruded forms a slight gap with the leading end p2a of the subsequent sheet p2 due to its inertia.
Even if p2 overlaps, they are separated from each other.

Therefore, after a short time, the paper feed roller 30 starts to rotate forward again, and accordingly, the transport roller 8
When 1 feeds out the subsequent sheet p2, this sheet is discharged onto the lower discharge tray 100 while properly pressing the rear end pb of the previous sheet p while maintaining the flat state.

On the other hand, when the preceding sheet p has been discharged, the remaining sheet p2 is pushed down at the center in the width direction by the knurled roller 92 while both sides are supported by the both-side supporting portions 91, 91. Due to the stiffness formed in a gutter shape as shown in FIG. 12 and strengthened in the transport direction, the paper is straightened while forming a gap with the previous sheet p discharged onto the sheet discharge tray 100. By delaying the time of going straight and making contact with each other, the previous sheet is prevented from being stained.

The above description has been given of the paper discharging method of the present invention using plain paper of a normal size. However, in the case of a narrow paper such as an envelope or a postcard, one side of the both ends supporting portion 91 is used. Paper can only be placed on it and cannot be formed in a gutter shape. However, since these papers are narrow and stiff, a sufficient gap is provided between them and the paper on the paper output tray 100. Can be discharged straight.

[0027]

As described above, according to the present invention, the paper having undergone the printing process is fed out while being held flat, and then the preceding paper is held while being held in a gutter-like concave state.
This is pressed and ejected by the leading edge of the succeeding paper, so that the printing section can perform good recording and writing.
On the other hand, the paper straightened in the longitudinal direction is fed as it is by the succeeding paper as it is, so that the contamination with ink can be further reduced.

Still further , at the stage of contact with the preceding paper
In in that the succeeding sheet so as to temporarily stop
Form a gap between the front and back sheets,
As a result, the preceding sheet can be more reliably discharged .

In addition, means for concavely forming the sheet in a gutter shape is provided.
With the rib-shaped member supporting both sides of the paper and the center in the width direction.
Printed because it is composed of a push-down knurled roller
Depressing paper smoothly and securely without disturbing the surface
Not only can be made, but also
Tilted upward in the direction of
Cooperating with the push-down knurled roller
Work can be made more reliable.

[0030]

[Brief description of the drawings]

FIG. 1 is a front view of a printer including a paper discharge device according to an embodiment of the present invention.

FIG. 2 is a top view of the same printer.

FIG. 3 is a side view of the printer.

FIG. 4 is a front view showing a sheet supply / discharge path for sheets.

FIG. 5 is a side view illustrating a normal rotation state of a sheet discharge unit.

FIG. 6 is a side view showing a reverse state of a sheet discharging unit.

FIG. 7 is a side view illustrating a sheet discharging unit.

FIG. 8 is a front view showing a discharge unit of the same.

FIG. 9 is an enlarged side view of the discharge unit.

FIG. 10 is a perspective view showing a depression jaw roller.

FIG. 11 is a detailed view showing a state of paper discharge.

FIG. 12 is an explanatory view of the same.

FIG. 13 is an explanatory diagram of the above.

FIG. 14 is an explanatory diagram of the same.

[Explanation of symbols]

 REFERENCE SIGNS LIST 30 paper feed path 70 paper discharge path 80 transport section 81 transport roller 82 transport jagged roller 85 transmission gear 90 discharge section 91 both-side support section 92 push-down jagged roller 93 arm 100 paper output tray

────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-1-267252 (JP, A) JP-A-4-39054 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) B41J 13/00-13/32 B65H 29/20

Claims (5)

(57) [Claims] As a method of discharging paper in a printer of a type that prints using an ink jet recording head, a paper that has been subjected to a printing process is sent out while being held flat, and then the paper is formed in a gutter shape in the paper transport direction. A method of discharging a sheet in an ink jet printer, wherein the sheet is pressed by a leading end portion of a succeeding sheet and discharged to a lower discharge section while being concaved. 2. The method according to claim 1, wherein the subsequent sheet is temporarily stopped when the sheet comes into contact with the preceding sheet. 3. A printing unit, which is provided on the lower side of the printing unit in the paper transport direction with a printing surface facing upward and transports the paper while holding the paper flat, and on both lower sides of the paper in the paper transport direction. As an ejection device for the paper in an ink jet printer provided with a gutter-shaped concave means for the paper which presses the center in the width direction downward while supporting the paper, the both-side support portions gradually move toward the lower side in the paper conveyance direction. A sheet discharging device in an ink jet printer, comprising an upper edge inclined to be higher. 4. The apparatus according to claim 1, wherein the gutter-shaped concave forming means comprises a rib-shaped both-side supporting portion for supporting both side portions of the sheet, and a push-down serrated roller for pushing down a central portion in the width direction of the sheet. 4. The sheet discharging apparatus according to claim 3, wherein the sheet is pivotally supported by a fixed member via an arm so as to be displaceable. 5. The sheet discharging device according to claim 3, wherein the pressing down roller is made displaceable by its own weight.