PAPER POST-PROCESSING APPARATUS

Abstract

A paper post-processing apparatus comprises a processing tray section; a post-processing section; a paper discharge tray section; a first chuck section configured to hold the rear end of the paper standing by in the buffer section; a second chuck section configured to hold the rear end of the paper loaded on the processing tray; and a third chuck section configured to hold the rear end of the paper loaded on the paper discharge tray; wherein a next paper is fed onto the paper held by the first chuck section in the buffer section, a paper is fed onto the paper held by the second chuck section from the buffer section in the processing tray section, and a paper is discharged onto the paper on the paper discharge tray held by the third chuck section from the processing tray section in the paper discharge tray section.

Description

CROSS-REFERENCE TO RELATED APPLICATION

This application is based upon and claims the benefit of priority from Japanese Patent Application No. 2013-078176, filed Apr. 4, 2013, the entire contents of which are incorporated herein by reference.

FIELD

Embodiments described herein relate to a technology in which a post-processing of a paper discharged from an image forming apparatus such as a copier, a printer and a compound machine is carried out.

BACKGROUND

A paper post-processing apparatus arranged at the paper discharge side of an image forming apparatus comprises an intermediate tray (buffering mechanism) configured to temporarily load a plurality of papers discharged from the image forming apparatus, a processing tray configured below the intermediate tray to load a plurality of papers falling from the intermediate tray, and a paper discharge tray configured to load the papers discharged from the processing tray.

The intermediate tray includes a pair of intermediate tray members which move along a horizontal direction orthogonal to a conveyance direction (longitudinal direction), and the plurality of papers temporarily loaded on the intermediate tray fall to the processing tray if the intermediate tray members move in a direction away from each other. At this time, the rear end part in the longitudinal direction of the paper is hit onto the processing tray through the rotation of a falling auxiliary member for carrying the rear end part in the longitudinal direction of the paper. Further, the rear end part in the longitudinal direction of the loaded paper is held by a rear end holding section, thereby preventing that the loaded paper is pushed forward due to the friction contact with the front end in the longitudinal direction of the next fed paper, that is, the front end in the conveyance direction when a plurality of papers is loaded on the intermediate tray in sequence.

It is preferred that the paper post-processing apparatus discharges papers at a processing speed the same as that (the number of printings per unit time) of the image forming apparatus. Thus, as the processing speed of the image forming apparatus is increased, it is necessary to increase the processing speed of the paper post-processing apparatus, meanwhile, it is also necessary to align the end parts of the discharged paper.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic front view illustrating a paper post-processing apparatus according to an embodiment;

FIG. 2 is an oblique view illustrating a buffer section shown in FIG. 1;

FIG. 3 is an oblique view illustrating a processing tray shown in FIG. 1;

FIG. 4 is a schematic diagram illustrating a first chuck section shown in FIG. 1; and

FIG. 5 is a schematic diagram illustrating a paddle part shown in FIG. 1.

DETAILED DESCRIPTION

In accordance with one embodiment, a paper post-processing apparatus comprises a buffer section configured to hold a standby paper fed from an image forming apparatus; a processing tray section arranged below the buffer section configured to include a processing tray to which a paper is fed from the buffer section, and be capable of conveying the paper fed from the buffer section and loaded on the processing tray towards a paper discharge direction; a post-processing section configured to carry out a post-processing on the paper loaded on the processing tray; a paper discharge tray section configured to include a paper discharge tray to which a paper bundle loaded on the processing tray and subjected to the post-processing is discharged; a first chuck section configured to hold the rear end of the paper standing by in the buffer section; a second chuck section configured to hold the rear end of the paper loaded on the processing tray; and a third chuck section configured to hold the rear end of the paper loaded on the paper discharge tray.

Then, the buffer section feeds a next paper onto the paper held by the first chuck section, the processing tray section feeds a paper from the buffer section onto the paper held by the second chuck section, and the paper discharge tray section discharges a paper from the processing tray section onto the paper on the paper discharge tray held by the third chuck section.

The paper post-processing apparatus according to the embodiment is described below with reference to the accompanying drawings.

FIG. 1 is a schematic diagram illustrating the paper post-processing apparatus according to the embodiment, FIG. 2 is an oblique view illustrating the paper buffer section shown in FIG. 1, and FIG. 3 is an oblique view illustrating the processing tray shown in FIG. 1.

A paper post-processing apparatus 1 described herein comprises a paper buffer section 3, a processing tray section 5, a stapler section 7 serving as a post-processing section which carries out a post-processing and a paper discharge tray section 9, and is arranged next to a paper discharge side of an image forming apparatus. A processing tray 51 of the processing tray section 5 is arranged below the paper buffer section 3, and the paper discharge tray section 9 and the stapler section 7 are respectively arranged at the front and rear sides of the processing tray 51 in a paper conveyance direction. In addition, the post-processing refers to, for example, a sorting processing, drilling processing, folding processing, saddle stitching processing and the like carried out on a printed paper.

A paper P discharged from an image forming apparatus (not shown) is continuously conveyed by a paper feed roller 11 to the paper buffer section 3. As to the paper P fed by the paper feed roller 11, the front end in the conveyance direction is referred to as the front end of the paper, and the rear end in the conveyance direction is referred to as the rear end of the paper. Further, the direction orthogonal to the conveyance direction is referred to as a width direction and the conveyance direction is referred to as a longitudinal direction.

The buffer section 3 holds one or a plurality of papers P on a pair of standby trays 31 which are arranged opposite to each other in the width direction, and contacts the rear ends of the papers P with a paddle 32 to align the rear ends in the longitudinal direction. The standby tray pairs 31 incline the front end of the paper upwards and contact the rear end of the paper P discharged to the standby tray 31 by the paper feed roller 11 with the paddle 32. When a second paper P is conveyed to the buffer section 3, the rear end part of the first paper P loaded on the standby tray 31 is held by the first chuck section 33. Further, the standby tray pairs 31 carry two ends in the width direction of the paper P, and if the standby tray pairs 31 move in the width direction and the distance therebetween is elongated, the paper P carried falls onto the processing tray 51 below the standby tray pairs 31.

As shown in FIG. 2, FIG. 4 (a) and FIG. 4 (b), the first chuck section 33 is arranged between a pair of paddles 32 which are arranged opposite to each other in the width direction. In the first chuck section 33, a base portion 33a is mounted, in a rotatable manner, on a support shaft 34 which extends in the width direction, and a plate-shaped chuck plate 33b extends from the base portion 33a towards outside. The first chuck section is driven by a first chuck driving section 35 to reciprocatingly rotate around the support shaft 34 within a given angle range. The first chuck driving section 35 reciprocatingly rotates the base portion 33a with an electromagnetic solenoid 35a serving as a driving source via a link part 35b, so as to rotationally move the chuck plate 33b between a position (holding position) for holding the paper P as shown in FIG. 4 (b) and a position (release position) away from the holding position for releasing the paper P as shown in FIG. 4 (a).

In the paddle 32, as shown in FIG. 5 (a), a plate-shaped first paddle part 32b serving as a pedestal part for carrying the rear end part of the paper P, a plate-shaped second paddle part 32c made of rubber member, a plate-shaped third paddle part 32d made of rubber member and a plate-shaped fourth paddle part 32e made of Mylar member are arranged around the base portion 32a at a given interval in a circumferential direction, and seen from the rotation direction, the second paddle part 32c is behind the first paddle part 32b, the third paddle part 32d is behind the second paddle part 32c and the fourth paddle part 32e is behind the third paddle part 32d. A base portion 32a is, for example, arranged on the support shaft 34 in a rotatable manner, and is intermittently driven by a paddle driving section (not shown).

In the present embodiment, a position where the first paddle part 32b waits to carry the rear end part of the paper P is referred to as a standby position. When a given number of papers P are conveyed to the paper buffer section 3, the standby tray pairs 31 move to enlarge the distance therebetween and the papers P fall; meanwhile, the paddle driving section rotates the paddle part 32 from the standby position in a direction for one round, and stops the first paddle part 32b again at the standby position.

In a standby state where the paper P is held on the standby tray 31, the paddle 32 stands by in such a manner that the first paddle part 32b is at an inclined position substantially parallel to the standby tray 31. When the rear end part of the first paper P is aligned and carried by the first paddle part 32b, the first chuck section 33 rotates the chuck plate 33b from the release position to the holding position. The holding position of the chuck plate 33b described herein refers to such a position where the paper P carried on the first paddle part 32b in the standby state is properly clamped between the chuck plate 33b and the first paddle part pairs 32b. In this way, by holding the rear end of the first paper P, it can be prevented that the first paper P is pushed forward due to the friction contact with the front end of the second paper P when the second paper P is discharged by the paper feed roller 11.

The first paddle part 32b is formed by hard resin such as polyoxymethylene (POM) resin and the like. When the rotation of the paddle part 32 is started, the rear end part of the paper P is no longer carried by the first paddle part 32b, and therefore falls and floats in the air, and then the rear end part of the paper P is hit downwards by the rotating second paddle part 32c, and then the paper P is loaded on the processing tray 51. The length of the second paddle part 32c is set to a specific value such that it is long enough to hit the paper P down to the processing tray 51.

Then, the rotating third paddle part 32d contacts with the paper P loaded on the processing tray 51 and slides so as to contact the rear end of the paper P with the stopper section 52 arranged at the rear side through friction force to align the rear ends of the papers. Therefore, the third paddle part 32d is formed longer than the second paddle part 32c. Then the paddle part 32 continues to rotate and stops in such a state where the first paddle part 32b reaches the standby position. In this state, the fourth paddle part 32e is brought into press contact with the upmost paper P of the papers P loaded on the processing tray 51, which prevents the paper P on the processing tray 51 from being pushed forwards by accident, and thereby preventing a poor alignment of papers.

The fourth paddle part 32e made of a Mylar sheet is weak in elastic force, and for the papers P loaded on the processing tray 51, the fourth paddle part 32e almost has no forward paper conveyance force against the fed paper P when the paper P falls from the paper buffer section 3, therefore, the papers P on the processing tray 51 won't be moved due to the falling paper P and a good alignment is maintained.

However, if a strong forward paper conveyance force is generated against the paper P fed from the paper buffer section 3, there is a risk that the papers P on the processing tray 51 cannot be held at the aligning position through the holding force of the fourth paddle part 32e.

Thus, in the present embodiment, the papers P loaded on the processing tray 51 are forcibly held at the aligning position by a second chuck section 60.

The processing tray 51 holds the loaded papers P in an aligned manner during a period when, for example, the papers P are subjected to a stapling processing by the stapler section serving as a processing mechanism for carrying out a post-processing. As shown in FIG. 3, the papers loaded on the processing tray 51 are aligned in a horizontal direction by a pair of horizontal alignment plates 55, 55 which are arranged opposite to each other and are capable of moving in a direction indicated by an arrow V according to the width of the paper P.

The second chuck section 60 is arranged below the paddle part 32 so as to avoid the interference with the stapler section 7. The second chuck section 60 includes a second chuck main body section 63 formed by, for example, mounting a pressing plate 62 at the front end of an arm part 61, and a second chuck driving section (not shown) for driving the arm part 61. In the second chuck main body section 63, the pressing plate 62 is set to be capable of reciprocatingly moving between a pressing position where the pressing plate 62 is brought into press contact with the surface of the upmost paper P loaded on the processing tray 51 and a retracting position retracting upwards from the pressing position.

The second chuck section 60 holds and presses the papers on the processing tray 51 when the paper P is fed from the buffer section 3 to the processing tray 51, and retracts the pressing plate 62 to the retracting position during a period from the moment the rotation of the paddle part 32 is started to the moment the first paddle part 32b is stopped at the standby position again, and moves the pressing plate 62 to the pressing position when the first paddle part 32b is stopped at the standby position.

The second chuck section 60 mounts the arm part 61 on a link mechanism (not shown) or a cam mechanism (not shown) which is reciprocatingly driven by a driving source such as an electromagnetic solenoid and the like, and moves the pressing plate 62 upwards or downwards between the retracting position and the pressing position.

Though the number of papers loaded on the processing tray 51 is increased and the height of the loaded papers becomes high, if the pressing plate 62 presses the papers, then the chuck section 60 stops the downward movement of the pressing plate 62 and can hold the paper at a certain pressing force. For example, the pressing plate 62 is energized by a spring member (not shown) against the arm part 61, and moves against the spring force of the spring member through the contact with the paper. Then if the movement of the pressing plate 62 is detected, the driving source of the second chuck section 60 is stopped. The outer periphery of the pressing plate 62 is formed in an arc shape so as to avoid the interference with the rear end of the paper P hit down by the second paddle part 32c.

On the other hand, when the paper buffer section 3 holds, for example, two papers P on the standby tray pairs 31, the two papers P are fed at a time. However, as the processing speed of the image forming apparatus is increased, it is preferred to increase the processing speed of the post-processing apparatus 1 such that the post-processing apparatus 1 carries out a paper post-processing at a speed the same as that of the image forming apparatus. In this case, instead of waiting until, for example, two papers P are held on the standby tray 31 of the paper buffer section 3 and then moving the standby tray pairs 31 to let the two papers P fall simultaneously, the first paper P is made to stand by on the standby tray 31, and then the paper P falls by moving the standby tray pairs 31 in a state where the rear end part thereof is held by the first chuck section 33 before the second paper P is discharged by the paper feed roller 11. In this case, as shown in FIG. 5 (b), the front end of the first paper P contacts with the paper P on the processing tray 51.

Then, the second paper P is directly discharged on the first paper P from the paper feed roller 11, and then the paddle part 32 is rotated. In this case, the time taken until the two papers P falls and are loaded on the processing tray 51 is shortened, thereby increasing the processing speed of the post-processing apparatus 1. At this time, as the paper P or the paper bundle on the processing tray 51 is held by the second chuck section 60, the paper P on the processing tray 51 won't move towards the front end side of the paper even if the friction force generated due to the conveyance force in the paper conveyance direction of the paper P fed from the paper buffer section 3 acts upon the paper P on the processing tray 51, thereby maintaining as good alignment of the papers.

In this case, as the standby tray 31 functions so as to hold the rear end part of the first paper P in the first chuck section 33, the standby tray pairs 31 are not needed as long as the first paper P discharged from the paper feed roller 11 can be guided to the first paddle part 32b of the paddle 32 and the rear end part of the paper P can be held by the first chuck section 33.

The rear ends of the paper P loaded on the processing tray abut the stopper section 52 and are aligned in the longitudinal direction, and if a certain number of papers P are loaded on the processing tray 51, the stapler section 7 moves along the width direction and carries out the stapling processing at a given position. When the stapling processing is ended, the stopper section 52 moves forward to move the paper bundle onto the processing tray 51.

As shown in FIG. 3, a conveyance belt 53 for conveying the paper to the paper discharge tray section 9 is arranged at the center part in the width direction of the processing tray 51. A paper feed claw 54 is arranged in the conveyance belt 53 to hook and convey the paper bundle on the processing tray 51 to the paper discharge tray section 9. Similarly, the loaded paper needs no stapling processing is also conveyed to the paper discharge tray section 9 by the paper feed claw 54.

In the paper discharge tray section 9, a plurality of paper discharge trays 91 is obliquely arranged on the tray support section 92 in such a manner that each paper discharge tray 91 can be moved upwards or downwards against the tray support section 92 by a paper discharge tray driving section (not shown). A paper discharge roller 93 is arranged at the conveyance end of the processing tray 51 to discharge the paper P conveyed from the processing tray 51 to the selected paper discharge tray 91.

A small gap is formed between the rear end of the paper discharge tray 91 and a paper abutting aligning plate 94 which is arranged on the tray support section 92 and is capable of sliding upwards or downwards, and the rear ends of the papers or the paper bundles loaded on the paper discharge tray 91 contact with the paper abutting aligning plate 94 and are aligned in the longitudinal direction.

As the paper discharge tray 91 is obliquely arranged in such a manner that the front end thereof is inclined upwards, the discharged paper P or the paper bundle slides down along the inclined surface, and the rear end thereof contacts with the paper abutting aligning plate 94 arranged on the tray support section 92 at a position more rear than the inclined down end of the paper discharge tray 91, thereby carrying out an aligning processing in the longitudinal direction.

In a case of continuously discharging the paper P or the paper bundle to the paper discharge tray 91, the paper P or the paper bundle moved by the paper discharge roller 93 along the paper discharge direction contacts with the surface of the paper P or the paper bundle which is already discharged and loaded on the paper discharge tray 91, the paper or the paper bundle on the paper discharge tray 91 is pushed forward and the alignment in the longitudinal direction is disorganized. Particularly, as the paper bundle is heavier than a case of discharging two or three papers at a time, the paper on the paper discharge tray 91 will be pushed forward more easily in a case of discharging a paper bundle.

In the present embodiment, the paper P loaded on the paper discharge tray 91 is held by the third chuck section 70, thereby preventing the paper P or the paper bundle loaded on the paper discharge tray 91 from being pushed forward by the conveyance force of the discharged paper.

In addition, the first chuck section 33, the second chuck section 60 and the third chuck section 70 are arranged more rear than the minimum paper size length L in the paper conveyance direction.

The third chuck section 70 has a paper abutting section 71 arranged below the paper discharge position in an up-and-down direction based on the paper discharge roller 93. The paper abutting section 71 protrudes more forward than the paper abutting aligning plate 94.

The paper abutting section 71 is formed in such a manner that a paper abutting surface 73 thereof which is parallel to the paper discharge tray 91 faces to the paper discharge tray 91. Further, the paper abutting aligning plate 94 is arranged in a specific range so that the paper abutting aligning plate 94 can contact with the rear end of the paper or paper bundle loaded between the paper abutting surface 73 of the paper abutting section 71 and the paper discharge tray 91, for example, the paper abutting aligning plate 94 can be used as a gate for closing a paper discharge port 95 through which the paper is discharged by the paper discharge roller 93 positioned above the paper abutting section 71. In the present embodiment, the paper abutting aligning plate 94 moves downwards to open the paper discharge port 95 when the paper is discharged from the paper discharge port 95, and moves upwards to close the paper discharge port 95 when the paper discharge operation is ended. A cutout part (not shown) is formed on the paper abutting aligning plate 94 at the part corresponding to the paper abutting section 71, so as not to interfere with the paper abutting section 71 when the paper abutting aligning plate 94 moves upwards.

In a state of loading the papers P, the paper discharge tray 91 moves upwards until the surface of the loaded paper P contacts with the paper abutting surface 73 of the paper abutting section 71, so as to hold the paper P in a manner of clamping the paper P between the paper discharge tray 91 and the paper abutting surface 73. When a paper P or a paper bundle is discharged from the paper discharge roller 93, the paper discharge tray 91 moves downwards to form a gap between the paper discharge tray 91 and the paper abutting surface 73 so that the discharged paper or the paper bundle can enter the gap, and then moves upwards to hold the loaded paper.

In the present embodiment, the outer peripheral surface 72 of the paper abutting section 71 is formed as an inclined surface, therefore, the falling paper or paper bundle discharged from the paper discharge roller 93 can be loaded on the paper discharge tray 91 smoothly without any interference even if the rear end thereof contacts with the paper abutting section 71.

In addition, the component constituting the paper abutting surface 73 may be energized by a spring member against the paper abutting section 71, and a spring force of the spring member is applied to the paper thereby holding the paper. In this case, the upward movement of the paper discharge tray 91 can be stopped through detection on the movement of the component constituting the paper abutting surface.

In this way, the paper post-processing apparatus 1 described herein holds the paper P standing by on the buffer section 3 by the first chuck section 33, which prevents the paper P loaded on the buffer section 3 from being pushed forward by a next fed paper, thereby feeding the paper to the processing tray 51 of the processing tray section 5 in a good alignment in the longitudinal direction. At this time, as the rear ends of the papers or the paper bundles loaded on the processing tray 51 are maintained in a good alignment and held by the second chuck section 60, the paper or the paper bundle loaded on the processing tray 51 can be prevented from being pushed forward due to the contact with the paper fed from the buffer section 3.

Further, when the paper or the paper bundle loaded on the processing tray 51 is discharged to the paper discharge tray section 9, the paper or the paper bundle loaded on the paper discharge tray 91, which is held by the third chuck section 70, is therefore prevented from being pushed forward due to the contact with the paper or paper bundle discharged and conveyed by the paper discharge roller 93.

Thus, the paper or the paper bundle discharged and loaded on the paper discharge tray 91 is maintained in a good alignment in the longitudinal direction at the buffer section 3, the processing tray section 5 and the paper discharge tray section 9, respectively, therefore the paper finally discharged to the paper discharge tray 91 is loaded and maintained in a good alignment in the longitudinal direction and horizontal direction. In addition, the paper post-processing apparatus according to the present embodiment is described as an apparatus independent from the image forming apparatus; however, the present invention is not limited to this, the paper post-processing apparatus may also be integrated with the image forming apparatus.

While certain embodiments have been described, these embodiments have been presented by way of example only, and are not intended to limit the scope of the invention. Indeed, the novel embodiments described herein may be embodied in a variety of other forms; furthermore, various omissions, substitutions and changes in the form of the embodiments described herein may be made without departing from the spirit of the invention. The accompanying claims and their equivalents are intended to cover such forms or modifications as would fall within the scope and spirit of the invention.

Claims

1. A paper post-processing apparatus, comprising:

a buffer section configured to hold a standby paper fed from an image forming apparatus;

a processing tray section arranged below the buffer section and configured to include a processing tray to which a paper is fed from the buffer section, and be capable of conveying the paper fed from the buffer section and loaded on the processing tray towards a paper discharge direction;

a post-processing section configured to carry out a post-processing on the paper loaded on the processing tray;

a paper discharge tray section configured to include a paper discharge tray to which a paper bundle loaded on the processing tray and subjected to the post-processing is discharged;

a first chuck section configured to hold the rear end of the paper standing by in the buffer section;

a second chuck section configured to hold the rear end of the paper loaded on the processing tray; and

a third chuck section configured to hold the rear end of the paper loaded on the paper discharge tray; wherein

a next paper is fed onto the paper held by the first chuck section in the buffer section, a paper is fed onto the paper held by the second chuck section from the buffer section in the processing tray section, and a paper is discharged onto the paper on the paper discharge tray held by the third chuck section from the processing tray section in the paper discharge tray section.

2. The paper post-processing apparatus according to claim 1, wherein

the buffer section feeds a plurality of papers loaded on the standby tray to the processing tray by letting the papers fall.

3. The paper post-processing apparatus according to claim 1, wherein

the buffer section feeds a next paper, in a state of contacting the front end of the paper held by the first chuck section with the paper on the processing tray, onto the paper held by the first chuck section.

4. The paper post-processing apparatus according to claim 1, wherein

the second chuck section has a structure in which the paper is pressed from above.

5. The paper post-processing apparatus according to claim 1, wherein

the third chuck section has a paper abutting section which abuts the surface of the rear end of the paper loaded on the paper discharge tray so as to hold the paper through an upward movement of a paper discharge tray which is capable of moving in the vertical direction.

6. The paper post-processing apparatus according to claim 2, wherein

the second chuck section has a structure in which the paper is pressed from above.

7. The paper post-processing apparatus according to claim 3, wherein

the second chuck section has a structure in which the paper is pressed from above.

8. The paper post-processing apparatus according to claim 2, wherein

the third chuck section has a paper abutting section which abuts the surface of the rear end of the paper loaded on the paper discharge tray so as to hold the paper through an upward movement of a paper discharge tray which is capable of moving in the vertical direction.

9. The paper post-processing apparatus according to claim 3, wherein

the third chuck section has a paper abutting section which abuts the surface of the rear end of the paper loaded on the paper discharge tray so as to hold the paper through an upward movement of a paper discharge tray which is capable of moving in the vertical direction.

10. The paper post-processing apparatus according to claim 4, wherein

the third chuck section has a paper abutting section which abuts the surface of the rear end of the paper loaded on the paper discharge tray so as to hold the paper through an upward movement of a paper discharge tray which is capable of moving in the vertical direction.