JP2003104607A - Sheet extruding mechanism for picture image formation device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a constitutionally simple sheet extruding mechanism for a picture image formation device capable of extruding a printed sheet from a printing section to a discharge section forcibly. SOLUTION: This sheet extruding mechanism for the picture image formation device is provided with a sheet extruding arm 22 rotating in both forward and reverse directions freely to a sheet conveying direction and returning to an initial position freely, an actuator 23 rotating in both forward and reverse directions freely to the sheet conveying direction and making the sheet extruding arm 22 rotate by abutting the sheet extruding arm 22, and a resilient member 24 making the sheet extruding arm 22 return to the initial position. The sheet extruding arm 22 is rotated through the actuator 23 by a sheet conveying force using flexibility of a sheet. A sheet 3 is extruded forcibly with the energizing force of the resilient member 24 saved meanwhile forcibly.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a paper pushing mechanism of an image forming apparatus for forming an image on a recording medium by an ink jet head.

[0002]

2. Description of the Related Art Today, with the increase in the amount of information processing, image forming apparatuses such as various printers have many printed sheets.
There is a demand for an excellent paper ejection function that can reliably eject paper onto the paper ejection tray in a well-organized state.

Therefore, for example, Japanese Patent Laid-Open No. 3-227875.
In the publication, there is provided a paper ejection device in which a kick roller is provided in the paper ejection roller portion, and the paper after printing is sandwiched by the kick roller and the paper ejection roller so that the paper can be reliably ejected onto a paper ejection tray. Proposed.

[0004]

By the way, in an ink jet printer which performs a printing process by ejecting ink from an ink jet head onto a sheet, when the next sheet under printing overlaps the sheet immediately after printing, the ink is It may be rubbed to significantly deteriorate the print quality.

From the above, for example, FIG.
As shown in FIG. 3, a waist attachment portion 15 is provided immediately after the paper discharge roller 14 so that the rear end of the paper 3 discharged after printing is slightly lifted, and the paper 3 is printed on the paper 3 after printing. In some cases, the leading edge of the next sheet 31 does not overlap.

However, the above conventional example (Japanese Patent Laid-Open No. 3-2278).
No. 75), in a configuration in which a kick-out roller is simply provided in the paper discharge roller portion, when such a waist mounting portion 15 protruding upward is provided, the waist mounting portion 15 is large with respect to the sheet. Because of resistance, the paper may not be completely ejected.

That is, since the kicking force for the discharged paper does not act at all on the downstream side of the paper discharge roller portion, the rear end of the paper 3 has the waist portion 15 as shown in FIG. 5B. In some cases, the paper 3 may stop while still riding on.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and it is an object of the present invention to provide a paper push-out mechanism for an image forming apparatus having a simple structure capable of forcibly pushing out a printed paper from a printing portion to a discharge portion. To aim.

[0009]

The present invention has means for solving the above-mentioned problems as follows.

(1) A sheet pushing mechanism of an image forming apparatus for forcibly pushing a printed sheet from a printing section to a sheet discharging section, which can be freely rotated in forward and backward directions in the sheet conveying direction and can be returned to an initial position. The paper push-out arm, an actuator arranged upstream of the paper push-out arm, capable of rotating in the forward and reverse directions in the paper transport direction, abutting against the paper push-out arm to rotate the paper push-out arm, and the paper push-out arm. An elastic member for returning to the initial position, and the actuator pushes the paper pushing arm from the initial position to the preparation position by rotating the actuator while contacting the paper passing through the print conveyance path. After that, when the paper pushing arm is returned to the initial position by the urging force of the elastic member, the paper is pushed out toward the paper discharge unit.

In this structure, the paper feeding force utilizing the waist of the paper causes the paper pushing arm to rotate via the actuator, and the paper is forcibly forced by the urging force of the elastic member stored therebetween. Since the sheet is pushed out, the sheet can be forcibly ejected (even when the waist portion is provided) with a simple structure without the need for another drive source.

(2) At the preparation position, the tip end portion of the paper pushing arm is moved to the upstream side of the nip portion of the discharge roller, and the nip portion of the discharge roller is in the paper pushing operation range of the paper pushing arm. Is included in.

In this structure, at the time when the paper is in the nip portion of the discharge roller, the relative position of the paper with respect to the paper pushing arm is stable with the paper held at the predetermined height position. By including the state in the paper ejection operation range of the paper ejection arm, the paper can be reliably brought into contact with the paper ejection arm without being released, and the paper can be reliably pushed out.

(3) At the preparation position, the leading end of the paper pushing arm is pushed down to a position lower than the nip portion of the discharge roller.

In this structure, since the paper passes over the tip of the paper pushing arm, the paper can be smoothly pushed out (without the paper pushing arm becoming a resistance).

(4) The paper pushing arm and the actuator are arranged in the width direction of the paper and are integrally formed.

In this structure, since the paper pushing arm and the actuator arranged in the width direction of the paper are integrally formed, they abut on the paper in the width direction, so that they act on the paper. Since the pushing force and the reaction force that the paper receives from the actuator simultaneously act uniformly in the width direction of the paper, it is possible to prevent the occurrence of deformation or tear of the paper edge, and the paper is pushed out in the appropriate direction. .

(5) A discharge roller is provided above the actuator.

In this structure, since the discharging roller is provided above the actuator, the discharging roller presses the sheet when the leading edge of the sheet comes into contact with the actuator, so that the sheet is prevented from escaping upward. Therefore, the actuator can be operated reliably.

[0020]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, a paper pushing mechanism of an image forming apparatus according to an embodiment of the present invention will be described in detail with reference to the drawings.

1 and 2 show the main construction of an ink jet printer 1 as an image forming apparatus. In these drawings, reference numeral 2 denotes a paper feed tray detachably attached to the apparatus main body, which accommodates sheets 3 as recording media by stacking them in an inclined state. A paper feed roller 4 is connected to a drive source (not shown) and is rotationally driven in the direction of the arrow to continuously feed the paper 3 one by one. Denoted at 5 is a separating plate, which is urged by the spring 6 against the paper feed roller 4 to press the paper 3
To prevent double feeding.

Reference numeral 7 denotes a guide plate for guiding the paper 3, and 8
Is a conveyance roller, 9 is a platen, 10 is a carriage in which the inkjet head 101 is housed, 11 is a guide rail for guiding the carriage 10 in the main scanning direction, and 12 is a wire for moving the carriage 10 in the main scanning direction. Thus, it is interlocked with the drive unit 13 on the side of the apparatus body. Reference numeral 14 is a discharge roller, 15 is a waist mounting portion, and 16 is a discharge tray.

With such a configuration, the paper feed roller 4 is rotated to feed the uppermost sheet 3 by a print command from a separately connected personal computer or the like, and the transport roller 8 carries the sheet 3 onto the platen 9. Carriage 10
Moves to the print start position, and moves from the inkjet head 101 to the paper 3 based on the print information while moving in the main scanning direction.
Printing is performed by ejecting ink onto the top.

When printing of a predetermined line is completed, the paper 3
Moves in the sub-scanning direction, printing of the next line is performed, and when printing of the final line ends, the rear end of the sheet 3 is slightly lifted upward by the waist attachment section 15, and then the sheet 3 is placed on the discharge tray 16. While being ejected, the next sheet 3 is supplied, and thereafter, the feeding, printing, and ejecting operations are continuously repeated in the same manner until the print information is exhausted.

In the paper discharging process, the rear end of the printed paper 3 is slightly lifted up by the waist attachment portion 15, so that the ink can be prevented from being rubbed by the next paper 3, which is good. It is possible to secure good printing quality. In particular, in the present embodiment, the printed sheet 3 having the rear end slightly lifted up by the waist attachment portion 15
A paper push-out mechanism 21 for surely pushing (kicking) the paper into the paper discharge tray 16 is provided.

The paper push-out mechanism 21 is shown in FIG.
As shown in FIGS. 4A and 4B, the paper push-out arm 22 which is rotatable in the paper transport direction and can be returned to the initial position, and the paper push-out arm 22 is arranged upstream of the paper push-out arm 22. An actuator 23 that is rotatable in the forward and reverse directions in the conveying direction and contacts the paper pushing arm 22 to rotate the paper pushing arm 22, and an elastic member 24 that returns the paper pushing arm 22 to the initial position are provided. ing.

The structure of the paper pushing mechanism 21 and its peripheral portion will be described in more detail.
Are integrally formed in the width direction of the sheet 3, and an upper arm 221 that abuts the rear end of the sheet 3 to push out the sheet 3 and a lower arm 222 that is biased upward by a coil spring 24 as an elastic member. As shown in the side view, and are integrated in a state of being bent into an acute angle, and the bent portion s is rotatably supported by the apparatus main body (not shown).

In the free state, the coil spring 24 urges it counterclockwise to bring the upper arm 221 into contact with the stopper 223 provided on the apparatus main body side to set the initial position shown in FIG. 3 (a). Thus, the coil spring 24 can be rotated to the preparation position shown in FIG. 3B against the biasing force of the coil spring 24. In its ready position,
The tip of the upper arm 221 has a driving roller (discharge roller) 1
It is pushed down to a position lower than the nip portion 41.

The actuator 23 is used for the paper pushing arm 2
An upper arm 231 arranged upstream of the sheet 2, integrally formed in the width direction of the sheet 3, and contacting the front end of the sheet 3;
The lower arm 232 that abuts the lower arm 222 of the paper ejection arm 22 in the initial position and rotates the paper ejection arm 22 to the preparation position shown in FIG. 3B is at a right angle as shown in the side view. It is integrated in a bent state, and the bent portion s is rotatably supported by the apparatus main body (not shown).

In the free state, the lower arm 232
Is urged upwardly on the upper arm 221 of the paper pushing arm 22, the upper arm 231 contacts a stopper 233 provided on the apparatus main body side, and is set to the initial position shown in FIG. 3A. And the paper 3 to be conveyed is the upper arm 23.
By abutting against 1, the paper ejecting arm 22 is rotated counterclockwise in the drawing by a predetermined angle and is rotated to the preparation position shown in FIG. 3B. Since the above-mentioned stopper 233 is provided on the apparatus main body side, one of the stoppers 2
23 may be omitted.

On the other hand, the conveying rollers 8 arranged on the upstream side of the carriage 10 include an upper roller 81 provided on the front side of the sheet 3 and a lower roller 82 provided on the rear side of the sheet 3.
The upper roller 81 is rotated by being driven by the lower roller 82 which is connected to a drive source (not shown) and rotationally driven.

The discharge roller 14 is composed of a drive roller 141 provided on the back side of the sheet 3 and two sets of star rollers 142, 143 for pressing the front side of the sheet 3. One star roller 142 is driven. The star roller 143 is provided at a position facing the roller 141, and the other star roller 143 is arranged at a position upstream of the facing position, above the actuator 23, specifically, above the upper arm 231 at the initial position.

With the above structure, the upper arm 231 of the actuator 23 at the initial position shown in FIG.
However, if it comes into contact with the leading edge of the sheet 3 passing through the print conveyance path,
By rotating counterclockwise, as shown in FIG. 3B, the paper pushing arm 22 is rotated to the preparation position. Since the other star roller 143 is arranged directly above the upper arm 231 of the actuator 23, the paper 3
The escape of the actuator is prevented, and the actuator 23 can be reliably rotated.

At the preparatory position, the tip of the upper arm 221 is moved to the upstream side of the nip portion of the driving roller 141 and is pushed down to the position lower than the nip portion of the driving roller 141. Therefore, the sheet 3 can pass therethrough without any hindrance, and the upper arm 221 of the sheet pushing arm 22 is surely brought into contact with the rear end of the sheet 3 held by the nip portion. Can be made.

The sheet 3 is the upper arm 2 of the actuator 23.
While the upper arm 221 of the paper push-out arm 22 is pushed down while passing through the sheet 31, when the paper 3 passes through the upper arm 231 of the actuator 23, as shown in FIG.
As shown in (a), the paper pushing arm 22 (and the actuator 2 are driven by the elastic force of the coil spring 24.
3) starts to return to the initial position, and at that time, the upper arm 221 of the paper pushing arm 22 surely abuts the rear end of the paper 3 and the paper 3 is ejected as shown in FIG. 4B. The sheet can be forcibly pushed out to the portion (sheet discharge tray 16).

The pushing force acts until the paper pushing arm 22 returns to the initial position. Therefore, the initial position of the upper arm 221 of the paper push-out arm 22 is set to the waist attachment portion 15
By setting the position slightly downstream of the rear end, the pushing force can be applied until the paper 3 surely gets over the waist attachment portion 15, and the paper 3 is reliably discharged to the paper discharge tray 16. be able to.

As the elastic member 24 for urging the paper pushing arm 22 to the initial position, a coil spring, a leaf spring, a torsion spring or the like may be used instead of the coil spring. Further, in the present embodiment, an inkjet printer is described as an example of the image forming apparatus, but the present invention is not limited to this, and a multicolor image forming apparatus, a black and white electrophotographic copying machine, a facsimile apparatus, and the like. It can be applied to various image forming apparatuses.

[0038]

As is apparent from the above description, the present invention has the following effects.

(1) The paper conveying force utilizing the waist of the paper causes the paper pushing arm to rotate through the actuator, and the paper is forcibly pushed out by the urging force of the elastic member stored therebetween. Therefore, it is possible to forcibly discharge the paper (even when the waist attachment portion is provided) with a simple configuration without requiring another drive source.

(2) Since the relative position of the sheet with respect to the sheet pushing arm is stable at the time when the sheet is gripped by the nip portion of the discharge roller, this state is included in the sheet pushing operation range of the sheet pushing arm. By doing so, the paper can be reliably brought into contact with the paper push-out arm without letting it escape,
The paper can be pushed out without fail.

(3) In the preparation position, the tip of the paper pushing arm is pushed down to a position lower than the nip portion of the discharge roller, so that the paper passes over the tip of the paper pushing arm and the paper is smoothly moved. Can be pushed out.

(4) Since the paper pushing arm and the actuator arranged in the width direction of the paper are integrally formed, the pushing force acting on the paper and the reaction force received by the paper from the actuator are simultaneously generated in the width direction of the paper. Can be prevented from being deformed or broken, and the paper can be pushed out in an appropriate direction.

(5) Since the discharge roller is provided above the actuator, the paper is pressed by the discharge roller when the leading edge of the paper comes into contact with the actuator.
It is possible to prevent the sheet from escaping upward, and to reliably operate the actuator.

[Brief description of drawings]

FIG. 1 is a perspective view showing a main configuration of an image forming apparatus of the present invention.

FIG. 2 is a side view of the same.

FIG. 3 is an explanatory diagram of the configuration and operation of the paper extruder configuration.

FIG. 4 is an explanatory diagram of a configuration and an operation of the paper extruder configuration.

FIG. 5 is an explanatory diagram of an operation in the case where a waist attachment portion is provided in the conventional image forming apparatus.

[Explanation of symbols]

3-Recording medium 14-Discharge roller 16-Paper discharge section 22-Paper Push Arm 23-actuator 24-Elastic member 143-Discharge roller

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Takahiro Fukunaga             22-22 Nagaikecho, Abeno-ku, Osaka-shi, Osaka             Inside the company (72) Inventor Ryosuke Sugiyama             22-22 Nagaikecho, Abeno-ku, Osaka-shi, Osaka             Inside the company F-term (reference) 2C056 EA16 FA10 HA28 HA33                 3F049 DA11 DA12 LA07 LB03                 3F106 AA10 LA07 LB03

Claims (5)

[Claims] 1. A paper push-out mechanism of an image forming apparatus for forcibly pushing a printed paper from a printing unit to a paper discharge unit, the paper being capable of rotating in forward and backward directions in the paper carrying direction and returning to an initial position. A push-out arm, an actuator that is arranged on the upstream side of the paper push-out arm, is rotatable in the forward and reverse directions in the paper transport direction, and contacts the paper push-out arm to rotate the paper push-out arm; An elastic member for returning to the position, and the actuator abuts against the sheet passing through the print conveyance path to rotate the sheet ejecting arm from the initial position to the preparation position. After that, when the paper pushing arm is returned to the initial position by the urging force of the elastic member, the paper is pushed out toward the paper ejecting unit, and the paper pushing out of the image forming apparatus is performed. Structure. 2. In the preparation position, the tip of the paper pushing arm is moved to the upstream side of the nip portion of the discharge roller, and the nip portion of the discharge roller is within the paper pushing operation range of the paper pushing arm. The sheet pushing mechanism of the image forming apparatus according to claim 1, wherein the sheet pushing mechanism is included. 3. The sheet extruding apparatus according to claim 1, wherein, at the preparation position, the tip of the sheet extruding arm is pushed down to a position lower than the nip portion of the discharge roller. mechanism. 4. The sheet of the image forming apparatus according to claim 1, wherein the sheet pushing arm and the actuator are arranged in a width direction of the sheet and are integrally formed. Extrusion mechanism. 5. The sheet pushing mechanism of the image forming apparatus according to claim 1, further comprising a discharge roller provided above the actuator.