JP2000255872A - Sheet loading device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a sheet loading device which can prevent a corner of a sheet or a bundle of sheets, which is discharged, from being bent, which can prevent a trailing end of a sheet from being damaged, or which can prevent loading alignment from being deteriorated. SOLUTION: In this device, bundles PA of sheets discharged from a discharge means are loaded one upon another, a limiting member 40 is planted, being extended from the discharge means side end of a sheet loading tray 23 which is inclined toward the discharge means, toward the discharge means. The bundles PA of sheets which are moved toward the discharge means due to the inclination of the sheet loading tray 23, are allowed to abut against the limiting member 40 in order to limit the movement of the bundles PA of sheets. The limiting member 40 is composed of parts 41 confronting both side corners of each of the bundles PA of sheets, and a part 42 confronting the center thereof, which is projected in the discharge direction, longer than the parts 41. With this arrangement, a corner part of the bundle PA of sheets discharged, can be prevented from abutting against the limiting member 40.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sheet stacking apparatus for stacking sheets or a bundle of sheets discharged from a discharging unit, and more particularly to a sheet stacking apparatus having a sheet stacking tray inclined toward the discharging unit.

[0002]

2. Description of the Related Art In a conventional image forming apparatus, after an image is formed on a sheet, a sheet or a sheet bundle is discharged to a sheet stacking device by discharge means.

FIG. 7 is a perspective view of such a conventional sheet stacking apparatus. In FIG. 7, reference numeral 53 denotes a sheet stacking tray. And a discharge roller pair 52 for detecting that the sheet P has been discharged by the discharge roller pair 51.

The sheet stacking tray 53 is slightly inclined from the horizontal to the discharge roller side in order to stack the discharged sheets P neatly. The sheet P moves to the discharge roller pair side, and is abutted against a standing wall 54 provided at the end of the sheet stacking tray 53 on the discharge roller side to be stacked.

The standing wall 54 forms a plane substantially parallel to the longitudinal direction of the discharge roller pair 51, while the standing wall 54 has a rib having a step of about 2 mm as shown in FIG. 55 are provided. By providing the plurality of ribs 55, the discharged sheet P can be smoothly dropped on the sheet stacking tray.

In the sheet stacking apparatus having such a configuration, the sheet P kicked out by the discharge roller 51 and discharged onto the sheet stacking tray is placed on the sheet stacking tray 5.
3 moves to the standing wall side, and the rear end is
Stops, and by repeating this, the sheets are sequentially stacked on the sheet stacking tray. As described above, the sheet P stacked on the sheet stacking tray is configured such that the rear end of each sheet abuts against the standing wall 54,
The loading alignment in the transport direction is adjusted.

[0007]

However, in such a conventional sheet stacking apparatus, for example, when the sheet P is skewed and discharged, the sheet P moves toward the standing wall due to the inclination of the sheet stacking tray 53. In this case, the rear end angle M of the sheet P may strike the standing wall 54 and break as shown in FIG. Further, when the sheets P are stacked in a state where only the rear end angle M of the sheets P is in contact with the standing wall 54, a phenomenon occurs in which the rear end angle M of the sheets P leans against the standing wall 54, and the stacking alignment is deteriorated.

On the other hand, when the image forming apparatus has a binding device for binding and stapling the sheets P, the sheet P
Are discharged to the sheet stacking tray 53 as a bundle. Since the sheet bundle is bound by staples or the like, the weight is heavier than that of a single sheet.

When such a sheet bundle is discharged onto the sheet stacking tray 53, the sheet bundle vigorously moves to the standing wall side due to the inclination of the sheet stacking tray 53 and collides with the standing wall 54. As a result, the rear end of the sheet bundle strongly comes into contact with the rib 55 on the standing wall, and the rear end of the sheet bundle is seriously damaged. Further, when the sheet bundle is skewed and discharged, large damage is given to the trailing edge of the sheet bundle as in the case of one sheet described above.

Accordingly, the present invention has been made in view of such circumstances, and prevents a corner of a discharged sheet or a sheet bundle from being broken, a rear end from being damaged, and a decrease in stacking alignment. It is an object of the present invention to provide a sheet stacking device capable of performing the above.

[0011]

According to the present invention, there is provided a sheet stacking apparatus for stacking sheets or a bundle of sheets discharged from a discharging means. After being erected at the end of the sheet stacking tray and discharged, the sheet or the sheet bundle moving due to the inclination of the sheet stacking tray is contacted to restrict the movement of the sheet or the sheet bundle. And a part facing the central portion of the sheet or the sheet bundle rather than a part facing the corners of the sheet or the sheet bundle. It is characterized in that it is formed so as to protrude in the direction of the bundle.

Further, the present invention is characterized in that the regulating member is erected from an end of the sheet stacking tray on a discharging means side toward the discharging means.

[0013] Also, in the present invention, the regulating member may be configured such that a protruding portion facing the central portion of the sheet or the sheet bundle is a flat surface, and the flat portion and a portion facing the corners of the sheet or the sheet bundle. Are provided with a smooth curved portion for connecting.

Further, the present invention is characterized in that the restricting member has a smooth curved shape at a protruding portion facing a central portion of the sheet or the sheet bundle.

Further, in the invention, it is preferable that the regulating member has a flat portion facing both corners of the sheet or the sheet bundle.

Further, as in the present invention, a sheet or a sheet bundle discharged from the discharge means is stacked, and a regulating member is set up from the discharge means side end of the sheet stacking tray inclined toward the discharge means toward the discharge means. At the same time, the sheet or the sheet bundle which is discharged and then moves toward the discharging means due to the inclination of the sheet stacking tray after being discharged is brought into contact with the regulating member to regulate the movement of the sheet or the sheet bundle. Further, by forming the regulating member such that a portion facing the central portion of the sheet or the sheet bundle protrudes in the discharge direction, than a portion facing both corners of the sheet or the sheet bundle, the discharged sheet is formed. Alternatively, the corners of the sheet bundle are prevented from hitting the regulating member.

[0017]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a diagram showing a configuration of an image forming apparatus provided with a sheet stacking device and a sheet binding device according to a first embodiment of the present invention.

In FIG. 1, reference numeral 1 denotes an image forming apparatus indicated by an imaginary line, and a sheet (transfer material) P is formed with an image by an image forming unit (not shown), and then an image forming apparatus main body 1 is formed.
The sheet is conveyed to a sheet binding device A connected below A.

Reference numeral 2 denotes an entrance conveying roller pair disposed at a sheet entrance 1B provided in the sheet binding apparatus A. Reference numeral 3 denotes an entrance sensor for detecting that the sheet P has entered the sheet binding apparatus A. Reference numeral 4 denotes a sheet. A guide plate for guiding P to the alignment tray 8, a pair of transport rollers 5 for transporting the sheet P to the alignment tray 8, and a sheet position detection lever 6 disposed near the pair of transport rollers 5.

Reference numeral 7 denotes an upper sheet guide plate for guiding the sheet P conveyed by the conveying roller pair 5. The sheet P conveyed by the conveying roller pair 5 by the upper sheet guide plate 7 is guided to an alignment tray 8. Thereafter, the sheets are aligned on the alignment tray 8 and temporarily loaded. Reference numeral 9 denotes a sheet rear end pressing rib for pressing the sheet rear end on the alignment tray, and has a slope so that the sheet P is urged toward the transport direction.

Reference numeral 10 denotes a transport belt for transporting the sheet P transported by the transport roller pair 5 further downstream in the transport direction. The transport belt 10 is configured to deform as the number of stacked sheets increases. I have. Reference numeral 11 denotes a sheet front end stopper provided on the downstream side in the conveyance direction. The sheet P conveyed by the conveyance belt 10 is stopped with the sheet front end abutting against the sheet front end stopper 11.

The conveying belt 10 is kept in contact with the sheet leading end stopper 11 even after the sheet leading end hits the sheet leading end stopper 11.
The uppermost sheet is in contact with the uppermost sheet and is always urged in the direction in which the uppermost sheet is transported in the transport direction. However, this transport belt 10
Does not have a conveying force enough to cause the sheet P to get over the sheet leading end stopper 11, so that the uppermost sheet always slips with the conveying belt 10 normally.

Reference numeral 12 denotes a conveyance guide for receiving the sheet P from the upper sheet guide 7 and guiding the leading end of the sheet P to the conveyance belt 10.
This is a static elimination brush for eliminating static electricity. The leading end of the charge removing brush 13 is always in contact with the uppermost sheet. In order to prevent the sheet P from returning in the direction opposite to the conveying direction of the sheet P, a counter is provided with respect to the returning direction of the sheet P. It is arranged at an angle such that

Reference numeral 14 denotes a sheet bundle conveying upper roller which is disposed at a position substantially coincident with a contact portion between the conveying belt 12 and the sheet and is displaced in the longitudinal direction, and is vertically moved by a lever 15 operated by a solenoid (not shown). It is configured to be able to move. Reference numeral 16 denotes a lower sheet bundle conveying roller disposed opposite to the upper sheet bundle conveying roller 14, which is driven at a predetermined timing by a drive source (not shown) to convey the sheet bundle.

Reference numeral 17 denotes a stacking detection lever for detecting that the sheets P are stacked on the alignment tray, and reference numeral 18 denotes a curl pressing lever for pressing the curl at the leading end of the sheet. . Reference numeral 19 denotes a sheet discharging upper roller for discharging the sheet bundle to the outside of the apparatus, which can be moved up and down by a lever 20.
Reference numeral 21 denotes a lower sheet discharge roller provided opposite to the upper sheet discharge roller 19, and reference numeral 22 denotes a discharge sensor provided in the vicinity of sheet discharge upper and lower rollers (hereinafter, referred to as a pair of discharge rollers) 19 and 21 as discharge means. is there.

Reference numeral 23 denotes a discharge stacking tray serving as a sheet stacking tray for stacking the discharged sheets P, and reference numeral 24 denotes a full stack detection lever for detecting full loading of the sheets P discharged onto the discharge stacking tray. 25 is a conveyor belt holder that regulates both sides of the conveyor belt 10 with a predetermined distance;
Reference numeral denotes an alignment plate for moving and aligning the sheet P in a direction perpendicular to the sheet conveying direction.

The matching plate 26 has a conical rotatable roller 27 as shown in FIG. In the same figure, 28 is a side plate of the apparatus provided opposite to the matching plate 26, 29 is a conical rotatable roller provided on the side plate 28 of the apparatus, and 30 and 31 are provided on the side plate 28. This is the abutting reference surface of the sheet P.

On the other hand, in FIG. 1, reference numeral 32 denotes a staple device for binding a sheet bundle by a known technique indicated by a dotted line. In this embodiment, a predetermined position of the sheet bundle is set in a direction parallel to the sheet conveying direction. Are arranged so that they can be bound at two places.

Next, the binding operation of the sheet P in the image forming apparatus 1 configured as described above will be described.

First, the sheet P discharged from the image forming apparatus 1 enters from the sheet entrance 1B of the sheet binding apparatus A, is transported by the entrance transport roller 2, the guide plate 4, and the transport roller pair 5, and is transferred to the alignment tray 8. Is discharged.

When the sheet is discharged to the alignment tray 8 as described above, the leading end of the sheet enters the transport belt 10. The entry of the sheet P into the sheet binding device is detected by the entrance sensor 3, and the discharge of the sheet P to the alignment tray 8 is detected by the sheet position detection lever 6.

Next, the sheet P discharged to the alignment tray 8
Is transported downstream in the transport direction by the transport belt 10,
The leading end of the sheet comes into contact with the leading end stopper 11.

When the sheet leading edge abuts on the sheet leading end stopper 11 in this manner, the transport belt 10 slips because the transporting force of the transport belt 10 is small. In this way, by always receiving a light conveyance force in the conveyance direction by the conveyance belt 10, the sheet P comes to a standby state on the alignment tray while being aligned in the conveyance direction.

On the other hand, the lateral alignment of the sheet P is performed by moving the alignment plate 26 in a direction orthogonal to the conveying direction and shifting the width of the sheet P in a predetermined direction. In this embodiment, the alignment operation is performed twice for each sheet other than the last sheet in order to surely perform the horizontal alignment before closing the sheet bundle.

That is, when the sheets P other than the last sheet are to be aligned in the horizontal direction, the alignment plate 26 is moved to a predetermined position, then the alignment plate is returned to the opening direction once, and then the alignment plate 26 is again adjusted to the predetermined position. It moves to the position. Further, four alignment operations are performed for the last sheet.

By repeating such a process, a predetermined number of sheets P are aligned on the alignment tray.
Load.

Next, a predetermined number of sheets P
After being stacked on the alignment tray, a solenoid (not shown) is activated at a predetermined timing, whereby the upper bundle transport roller 14 moves downward, and the sheets stacked on the alignment tray together with the lower bundle transport roller 16 are moved. Hold the bundle.

Next, when the sheet leading end stopper 11 rotates in the direction of the arrow shown in FIG. 1 to open the leading end of the sheet, the bundle carrying upper and lower rollers (hereinafter, referred to as bundle carrying roller pair) 14, 16 at a predetermined timing. Starts rotational driving, whereby the sheet bundle is conveyed toward the discharge roller pair.

The conveying speed of the sheet bundle is set to be lower than the conveying speed of conveying the sheet P onto the alignment tray in order to prevent the sheet bundle from shifting in the conveying direction at the time of conveying the sheet bundle. I have.

Next, when the leading end of the sheet bundle reaches a predetermined position, a solenoid (not shown) is actuated, whereby the upper sheet discharging roller 19 moves downward to pinch the sheet bundle together with the lower sheet discharging roller 21. I do. Thereafter, at a predetermined timing, the discharge roller pairs 19 and 21 start to rotate.
Thereby, the sheet bundle is conveyed to a predetermined position.

The bundle discharge speed of the pair of paper discharge rollers 19 and 21 and the bundle transport speed of the pair of bundle transport rollers 14 and 16 satisfy the relationship of bundle discharge speed ≧ bundle transport speed. The bundle is conveyed to a predetermined position without being slackened or shifted.

Next, when the sheet bundle is conveyed to a predetermined position, the conveyance is stopped once, and the first position is bound by the stapler 32 at this position. Thereafter, the sheet bundle is further conveyed by the bundle conveying roller pairs 14 and 15 and the bundle discharge roller pairs 19 and 21 and conveyed to the second staple position, and then stapled at the second position by the stapler 32.

The sheet bundle bound at two places by the stapler 32 is conveyed thereafter, the trailing end of the sheet bundle is kicked out by the sheet discharge lower roller 21, and is discharged onto the discharge stacking tray 23. You.

The discharge stacking tray 23 is inclined toward the discharge roller pair, and has a control member at the end of the discharge roller pair toward the discharge roller pair 19, 21 as shown in FIG. The standing wall 40 is integrally erected.

By providing the standing wall 40 at the end of the sheet discharge roller, the movement of the sheet bundle moving toward the sheet discharge roller due to the inclination of the sheet discharge stacking tray 23 is regulated. . Note that the height of the standing wall 40 is desirably set to a height as close as possible to the sheet discharge lower roller 21 in order to increase the stacking amount of the sheet discharge stacking tray 23.

Further, as shown in FIG. 4, the standing wall 40 has a flat portion (hereinafter referred to as a first portion) facing both corners of the sheet bundle PA.
A flat portion (hereinafter, referred to as a second flat portion) 42 facing the center portion of the sheet bundle protrudes in the discharge direction, rather than the flat portion 41), that is, the first flat portion 41 and the second flat portion 42 Are formed so as to have a predetermined step between them. Reference numeral 43 denotes a smooth curved portion for connecting the first flat portion 41 and the second flat portion 42.

Here, by providing such a standing wall 40, the sheet is kicked out by the sheet discharge lower roller 21 as described above, and then moves toward the standing wall due to the inclination of the sheet discharge tray 23. When the rear end of the sheet bundle moves, for example, parallel to the standing wall 40, the rear end of the sheet bundle PA contacts the second plane portion 42 of the standing wall 40 as shown in FIG. Become like

By receiving the rear end of the sheet bundle at the second plane portion 42, that is, the plane portion,
Damage such as a scratch on the rear end of the sheet can be prevented.

When the sheet bundle moves obliquely with respect to the standing wall 40, the step between the first plane portion 41 and the second plane portion 42 causes the inside (the sheet angle) of the rear end of the sheet bundle PA to move. 5 comes into contact with the smooth curved portion 43 as shown in FIG.

Further, since the inside of the rear end of the sheet bundle PA abuts against the curved portion 43, it is possible to prevent the corner of the rear end of the sheet bundle from colliding with the first flat portion 41 of the standing wall 40. Accordingly, it is possible to prevent the corners at the rear end of the sheet bundle from being broken or the corners from leaning against the standing wall 40 to reduce the stacking alignment.

The first flat portion 41 and the second flat portion 4
The larger the step difference with 2, the more reliably the corner of the sheet bundle rear end collides with the first flat portion 41.

Next, a second embodiment of the present invention will be described.

FIG. 6 is a top view of the discharge stacking tray of the sheet stacking apparatus according to the present embodiment. 4, the same reference numerals as those in FIG. 4 denote the same or corresponding parts.

In the figure, reference numeral 44 denotes the discharge stacking tray 23.
The standing wall 44 is a control member which is provided upright on the flat surface portion 45 facing both corners of the sheet bundle PA.
And a curved portion 46 protruding in the sheet discharging direction and facing the central portion of the sheet bundle PA.
In the present embodiment, the curved portion 46
Are all formed of smooth, concentric Rs.

By forming the standing wall 44 in such a shape, similar to the first embodiment described above,
Even after the sheet bundle PA is discharged onto the discharge stacking tray 23 and moves due to the inclination of the discharge stacking tray 23 and hits the standing wall 44, the rear end of the sheet bundle PA is curved by the standing wall 44. Since it hits the shape portion 46, it is not damaged.

Further, by forming the portion facing the central portion of the sheet bundle PA into a curved shape, even if the small-size sheet P1 is skewed and discharged as shown in FIG. Since the vicinity of the center of the rear end of the sheet P1 comes into contact with the curved portion 46 before the sheet P1, the corners of the sheet P1 can be prevented from being broken or damaged.

In this embodiment, the standing wall 4
Although the case has been described in which the flat wall 4 is composed of the flat portion 45 and the curved portion 46, the entire standing wall 44 may be formed in a curved shape.

In each of the embodiments described above, the case of stacking a sheet bundle has been described. However, the present invention is not limited to this, and the same effect can be obtained when stacking sheets one by one. It goes without saying that it plays.

[0060]

As described above, according to the present invention, the regulating member which comes into contact with a sheet or a sheet bundle which moves due to the inclination of the sheet stacking tray is made smaller than a portion which faces both corners of the sheet or the sheet bundle. By forming the portion facing the central portion of the sheet or the sheet bundle so as to protrude in the discharge direction, it is possible to prevent the corner of the discharged sheet or the sheet bundle from abutting on the regulating member. .

Thus, it is possible to prevent the corners of the discharged sheet or sheet bundle from breaking or from scratching the rear end. Furthermore, since it is possible to prevent the sheet or the sheet bundle from leaning on the regulating member, it is possible to prevent a decrease in the stacking alignment and to increase the actual number of stacked sheets.

Further, by forming the sheet or the portion facing the central portion of the sheet bundle into a curved shape, the above-described effect can be obtained even for a small-sized sheet.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating a configuration of an image forming apparatus including a sheet stacking device and a sheet binding device according to a first embodiment of the present invention.

FIG. 2 is a perspective view of an alignment plate portion of the image forming apparatus.

FIG. 3 is a perspective view of the sheet stacking device.

FIG. 4 is a top view of a discharge stacking tray of the sheet stacking apparatus.

FIG. 5 is a partially enlarged view of the discharge stacking tray.

FIG. 6 is a top view of a discharge stacking tray of a sheet stacking apparatus according to a second embodiment of the present invention.

FIG. 7 is a perspective view of a conventional sheet stacking apparatus.

FIG. 8 is a side sectional view of a main part of the conventional sheet stacking apparatus.

FIG. 9 is a diagram illustrating a problem in the conventional sheet stacking apparatus.

[Explanation of symbols]

 1 Image Forming Apparatus 19 Sheet Discharge Upper Roller 21 Sheet Discharge Lower Roller 23 Discharge Stacking Tray 40, 44 Standing Wall 41 First Flat Portion 42 Second Flat Portion 43 Curved Portion 45 Flat Portion 46 Curved Portion A Sheet Binding Device P Sheet P1 Small size sheet PA sheet bundle

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Yasuyoshi Hayakawa 3-30-2 Shimomaruko, Ota-ku, Tokyo Inside Canon Inc. (72) Inventor Masayoshi Fukatsu 3-30-2 Shimomaruko, Ota-ku, Tokyo Kia Within non-corporation (72) Inventor Atsushi Ogata 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. F-term (reference) 3F054 AA01 AB01 AC01 BA04 BG08 BG11 BH08

Claims (5)

[Claims] 1. A sheet stacking device for stacking sheets or a bundle of sheets discharged from a discharge unit, comprising: a sheet stacking tray on which the discharged sheets or a bundle of sheets are stacked and inclined; and an end of the sheet stacking tray. And a restricting member that, after being erected at the section and discharged, contacts the sheet or the sheet bundle that moves due to the inclination of the sheet stacking tray and regulates the movement of the sheet or the sheet bundle. The regulating member may be configured such that a portion facing the central portion of the sheet or the sheet bundle protrudes in a direction of the stacked sheets or the sheet bundle rather than a portion facing both corners of the sheet or the sheet bundle. A sheet stacking device characterized by being formed. 2. The sheet stacking apparatus according to claim 1, wherein the restricting member is erected from an end of the sheet stacking tray on a discharge unit side toward the discharge unit. 3. The regulating member according to claim 1, wherein the protruding portion facing the central portion of the sheet or the sheet bundle has a flat surface,
2. The sheet stacking apparatus according to claim 1, further comprising a smooth curved portion connecting the flat portion and portions facing both corners of the sheet or the sheet bundle. 4. The sheet stacking device according to claim 1, wherein the regulating member has a smooth curved shape at a protruding portion facing a central portion of the sheet or the sheet bundle. 5. The sheet stacking apparatus according to claim 3, wherein the regulating member has a flat surface at a portion facing both corners of the sheet or the sheet bundle.