JPH11217153A - Paper sheet post-processing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a paper sheet post-processing device capable of assorting discharged paper sheets with good matching performance even when the paper discharging interval is shortened by increasing the processing speed of a copying machine, and capable of preventing inconvenience in which a paper sheet bundle collapses from a discharged paper tray even when the stacking amount is increased. SOLUTION: A paper discharging mechanism 80 is provided with a straight feeding means for straight discharging a paper sheet 111 in the discharging direction and a diagonally feeding means for feeding the paper sheet diagonally in relation to the discharging direction, and assortment of paper sheets is performed by making use of the difference between the paper discharging attitudes of the straight feeding means and the diagonally feeding means. This paper discharging mechanism 80 is composed of at least two sets of roller pairs 33A, 33B arranged symmetrically with respect to the center CL of a paper discharging path, it functions as a straight feeding means when both rollers 33A, 33B are driven by the same revolution speed, and it functions as a diagonally feeding means when both roller pairs 33A, 33B are rotated at the different revolution speeds.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is provided in an image forming apparatus such as a copying machine or the like, and sorts and records recorded paper on which an image is recorded by the image forming apparatus in a single discharge tray with good consistency. The present invention relates to a sheet post-processing device.

[0002]

2. Description of the Related Art A sheet post-processing apparatus which is provided in a copying machine or the like and sorts sheets on which copied images and the like are recorded has a plurality of bins (tray), and is a sorter type of stacking and sorting in each bin. There are post-processing devices and finisher-type post-processing devices that perform sorting by reciprocating a single paper discharge tray right and left in a direction (horizontal direction) perpendicular to the paper discharge direction.

[0003]

In the finisher type post-processing apparatus, the paper discharge tray is reciprocated in the direction perpendicular to the paper discharge direction to sort the paper, and thus the paper is sorted to one of the moving positions. After the paper is discharged and stacked on the tray with the paper discharge tray moved, the movement of the paper discharge tray to the other moving position must be completed before the next paper is discharged. Therefore, the processing speed (C
As the speed of the PM or PPM increases, the reciprocating speed of the paper discharge tray must be increased in accordance with the paper discharge interval that is shortened accordingly. However, when the paper discharge tray is reciprocated at high speed, the stacking position of the paper bundles stacked on the tray is shifted due to the inertial force acting when the paper discharge tray moves, which makes it difficult to sort the paper bundles. When the stacking amount of the sheet bundle is large, a problem occurs such that the sheet bundle collapses from the discharge tray. Therefore, the problem to be solved by the present invention is that even if the paper discharge interval is shortened with an increase in the processing speed of a copying machine or the like, the discharged paper can be sorted with good consistency. An object of the present invention is to provide a sheet post-processing apparatus that does not cause a problem that a sheet bundle collapses from a sheet discharge tray even when a stacking amount increases.

[0004]

According to a first aspect of the present invention, there is provided a sheet post-processing apparatus for sorting and discharging sheets discharged from an image forming apparatus on a discharge tray. The paper discharge tray includes a lifting mechanism that raises and lowers the paper discharge tray in accordance with the number of stacked papers, and a paper discharge mechanism that discharges the conveyed paper onto the paper discharge tray, wherein the paper discharge mechanism discharges the paper in a discharge direction. A direct feeding means for discharging the paper straight and a skew feeding means for discharging the paper in a posture oblique to the discharging direction are provided, and the difference in the paper discharging posture between the direct feeding means and the skew feeding means is used to discharge the paper. Sorting was performed. According to the second aspect of the invention, based on the apparatus configuration of the first aspect, the direct-feeding unit and the skew-feeding unit are each provided with at least two sets of rollers disposed symmetrically with respect to the center of the sheet discharge path. The pair of rollers function as direct feeding means when both roller pairs are driven at the same rotation speed, and function as oblique feeding means when the rotation speeds of both roller pairs are different. Also, in the invention according to claim 3, on the premise of the device configuration according to claim 2,
The two pairs of rollers each include a driven roller and a driving roller that feeds the paper by rotating the driven roller by sandwiching the paper between the driven rollers, and one roller pair is the other roller pair. A second drive roller having a different diameter in addition to the first drive roller having the same diameter as the first drive roller, so that one of the first drive roller and the second drive roller can be selectively brought into contact with the sheet. Features. Further, in the invention according to a fourth aspect, on the premise of the apparatus configuration according to any one of the first to third aspects, the paper discharge mechanism discharges the paper in different postures with respect to the discharge direction. It is characterized by having a function to make paper. According to the fifth aspect of the invention, based on the apparatus configuration of any of the first to fourth aspects, the degree to which the sheet is inclined relative to the discharge direction is controlled according to the size of the sheet. It has a function.

[0005]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is an overall schematic configuration diagram showing a sheet post-processing apparatus according to an embodiment of the present invention. As shown, the sheet post-processing apparatus 100 includes a copier 200
The paper discharge sensor 13 and the entrance roller 1 are provided at the entrance 10 of the paper from the copying machine 200.
1 and a branching pawl 12, and the sheet fed by the branching pawl 12 in the direction of the discharge tray 1 and the stapling device 1
Sheets sent in four directions are separated. An upper conveyance roller 2, a discharge sensor 15, a discharge roller 3, a shift roller 7, a paper surface lever 16, a paper surface sensor 17, and the like are arranged on a conveyance path in the direction of the paper discharge tray 1, and a lower side in the conveyance path in the direction of the stapling device 14. Conveyance roller 4, paper ejection sensor 18, paper feed roller 6
Etc. are arranged. The lower transport roller 4 is driven by a transport motor described later, and the paper discharge tray 1 is moved up and down by a lifting mechanism having an up-down motor described later. A jogger fence 9 for aligning sheets and a return roller 5 are arranged above the stapling device 14, and a discharge belt 19 for discharging a bound sheet bundle is arranged behind the jogger fluence 9. Have been. As shown in FIG. 2, the jogger fluence 9 is disturbed by a jogger motor 26 via a jogger belt 49, and the return roller 5 is configured to perform a pendulum movement by a return solenoid 30. As shown in FIG. 3, a rear end fence 20 for abutting a bundle of sheets is provided below the jogger fence 9. Further, as shown in FIG. 4, the stapling device 14 includes a stapler moving motor 2.
7 is driven through the staple belt 50 and moves in the horizontal direction.

The operation of the sheet post-processing apparatus 100 is controlled by a CPU (central processing unit) built in the copying machine 200. FIG. 5 shows the configuration of a control system centered on the CPU. Signals from switches and sensors 25 of a control panel (not shown) provided on the upper surface of the main body of the copying machine 200 are I / O signals. It is input to the CPU 70 via the O interface 60. The CPU 70
In accordance with the input signal, the vertical motor 5 of the paper discharge tray 1
1, a shift motor 52, a switching solenoid 53 (for the branch claw 12), a return solenoid 30, a transport motor 54,
The discharge motor 34 (34A and 34B in FIG. 7), the staple motor 56, and the discharge motor 57 (the discharge belt 19)
), Stapler moving motor 27, jogger motor 26
Uproar. The pulse signal of the transport motor 54 is supplied to the CPU 7
It is input to 0 and counted, and the return solenoid 30 is controlled according to this count. In the above configuration,
The operation when the non-staple mode in which stapling is not performed is selected will be described. Paper is the entrance roller 11
The paper is sent by the upper transport roller 2 and is discharged by the discharge roller 3, the paper is vertically aligned by the shift roller 7, and is stacked on the paper discharge tray 1. At this time, the shift roller 7 is decelerated when the discharge sensor 15 detects the trailing edge of the sheet, thereby improving the stacking property. When the copied paper is sequentially discharged, the paper lever 16
In addition, the paper discharge sensor 1 is always maintained at an appropriate height by driving the vertical motor 51 by the paper surface sensor 17. Further, the paper discharge tray 1 is held at an angle so that the paper discharge tray edge 1a side is at a low position so that the discharged paper is brought into contact with the paper discharge tray edge 1a by its own weight and aligned. Also,
In the sort and stack modes, skew is discharged by a partition signal output from the control panel of the copying machine 200 or the like. Further, when a partition signal is output from the control panel, the skew discharge ends and the sheets are discharged straight, and the stacked sheets are sorted. Here, the skew discharge refers to discharging the paper in a posture oblique to the discharge direction A, such as the paper 111b shown in FIG. In addition, the degree of the sheet oblique to the discharge direction A (for example, the discharge direction A and the sheet 111b
Is called a skew amount.

Next, the principle of sorting sheets by skew discharge will be described with reference to FIG. The sheet 111a discharged straight in the transport direction (the direction A in the drawing) is dropped and stacked in a posture parallel to the discharge tray edge 1a.
On the other hand, the skewed sheet 111b is ejected with the resist shifted to the right side in the figure by L for the skew amount.
One corner (the lower left corner in this example) C of the sheet 111b falls in a posture in which it comes into contact with the discharge tray edge 1a first. Then, the sheet 111b rotates downward (in the direction of arrow B in the figure) due to the inclination of the sheet discharge tray 12, so that the sheets 111b are stacked in a posture parallel to the sheet discharge tray edge 1a. In this way, the skewed paper 111b is stacked with the registration shifted by L from the straight discharged paper 111a, so that the paper 111a and the paper 111b can be sorted. FIG. 7 shows a configuration example of a paper discharge mechanism for discharging the paper 111 straight or diagonally as described above. This paper discharge mechanism 80
Are two roller pairs 33A, 33B and two roller pairs 33A, 33B disposed symmetrically with respect to the center line CL (center line along the sheet transport direction) of the paper discharge path.
And two paper discharge motors 34A and 34B for driving the respective motors. Each of the roller pairs 33A and 33B is a discharge roller (drive roller) 3 which is in contact with the lower surface of the sheet 111.
a and 3b, and driven rollers 3 ′ and 3 ′ that are driven to rotate while the paper 111 is pressed against the discharge rollers 3a and 3b from above. The discharge rollers 3a and 3b are fixed to independent drive shafts 35a and 35b, respectively.
The driving force of the paper discharge motors 34A and 34B is transmitted to the driving roller 5b via the timing belts 36a and 36b, respectively, so that the driving motor 5b is independently rotated. The driven rollers 3 ', 3' are urged in the sheet pressing direction by a spring (not shown).

When the paper discharge mechanism 80 discharges the paper 111 straight in the transport direction, the paper discharge motors 34 are used.
A and 34B are driven at the same rotation speed. At this time, when the above-mentioned partition signal is issued, when the registration is shifted to the right as shown in FIG.
The skew is discharged by increasing the rotation of 4B or by decreasing the rotation of the discharge motor 34A. When the registration is to be discharged in the opposite direction, that is, to the left, the rotation of the discharge motor 34A may be increased or the rotation of the discharge motor 34B may be reduced. That is, the paper discharge mechanism 80
Functions as direct feeding means when both roller pairs 33A and 33B are driven at the same rotation speed, and functions as oblique feeding means when both rotation speeds of both roller pairs 33A and 33B are different. It is. Note that the length of paper transported differs depending on the size, so it is necessary to control the difference in the number of rotations of the paper discharge motors 34A and 34B according to the paper size. If this control is not performed, the skew amount increases as the size of the vertically long paper increases, and a problem such as the paper falling from the discharge tray 1 occurs. On the other hand, in the case of a short sheet, the skew amount is small, so that it is difficult to recognize the partition position of the sheet bundle. In order to prevent such a problem, the above CP
The control device having U70 at its core controls the discharge motor 34 so that the skew amount is constant at all paper sizes.
A difference between the rotation speeds of A and 34B is controlled, or a timing at which a difference is generated between the rotation speeds is controlled.

FIG. 8A is a plan view of an essential part showing another example of the structure of the paper discharge mechanism, and FIG. 8B is a sectional view taken along line BB of FIG. 8A. As shown in the drawing, the paper discharging mechanism 90 is configured such that one roller pair 33B ′ is driven by the driving roller 3 of the other roller pair 33A ′.
In addition to the first drive roller 3c having the same diameter R1 as the first drive roller 3c, a different diameter R2 (R
1 <R2). The first drive roller 3c and the second drive roller 3d share a common support shaft 14
8 are attached to the distal ends of separate arms 146 and 145 rotatably mounted in the up and down direction, respectively, and are driven to rotate at the same rotational speed by a drive mechanism (not shown). The arms 146 and 145 are urged downward by springs 147 and 147, respectively.
By exclusively turning on / off the electromagnetic solenoids 141 and 142 respectively connected via 43 and 144, either one can be pressed against the driven roller 3 ''. The driven roller 3 ″ has a common support shaft 149 with the driven roller 3 ′ of the other roller pair 33A ′.
It is rotatably supported by. The driven rollers 3 ′ and 3 ″ are urged in the sheet pressing direction by a spring (not shown) provided on the support shaft 149. When the paper discharging mechanism 90 discharges the paper 111 straight in the transport direction, the electromagnetic solenoid 141 is turned on and the electromagnetic solenoid 142 is turned off. That is, the first drive roller 3c of the roller pair 33B ′ is pressed against the driven roller 3 ″, and the second drive roller 3d is separated from the first drive roller 3c. It drives and discharges. The rotation speed of both rollers 3a, 3c is the same.

At this time, when the partitioning signal is issued, the on / off states of the electromagnetic solenoids 141 and 142 are reversed, and the second driving roller 3d of the roller pair 33B 'is pressed against the driven roller 3''to perform the first driving. The roller 3c is kept separated. As a result, the paper feed speed of one roller pair 33B 'is faster than that of the other roller pair 33B', and therefore, as shown in FIG. You. When the resist is discharged in the opposite direction, that is, shifted to the left, the radius R2 of the second driving roller 3d is set to be equal to the radius of the first driving roller 3d.
c and the radius R1 of the drive roller 3a may be set to be smaller. In the above description, the case where the sorting is performed by discharging the paper 111 straight or by discharging the paper obliquely has been described. However, the sorting may be performed even if the paper 111 is skewed and discharged in opposite directions. it can.

[0011]

As described above, according to the present invention, the following excellent effects can be exhibited. According to the first aspect of the present invention, the paper discharge tray is not reciprocated, that is, the paper discharge tray is only moved up and down, and the registration deviation caused by the skew discharge by the oblique feeding means with respect to the paper discharge position by the direct feeding means is used. Paper sorting.
Even if the paper discharge interval is shortened due to an increase in the processing speed of a copying machine or the like, the discharged paper can be sorted with good consistency, and the paper bundle can be discharged even when the stacking amount increases. Problems such as collapse from the paper tray can be prevented. According to the second aspect of the present invention, at least two pairs of rollers disposed symmetrically with respect to the center of the paper discharge path are driven at the same rotation speed to discharge the paper straight, The effect of claim 1 can be exerted by simply switching the operation of the mechanism, such as performing skew discharge with different numbers of rotations of the roller pair. According to the third aspect of the present invention, one roller pair includes a second driving roller having a different diameter in addition to the first driving roller having the same diameter as the driving roller of the other roller pair. The effect of claim 2 can be exerted by selectively allowing one of the two drive rollers to contact the sheet. Further, in the invention according to the fourth aspect, a function of discharging the paper in different directions with respect to the discharge direction is provided, so that the first to third aspects are provided.
The effect of can be exhibited. According to the fifth aspect of the present invention, a function of controlling the degree of discharging a sheet obliquely with respect to the discharging direction in accordance with the size of the sheet is provided.
Since the skew amount can be made constant for all paper sizes, it prevents problems such as dropping from the tray due to excessive skew amount, and difficulty in understanding the partition position of the paper bundle due to small skew amount. it can.

[Brief description of the drawings]

FIG. 1 is an overall schematic configuration diagram illustrating a sheet post-processing apparatus according to an embodiment of the present invention.

FIG. 2 is a partial perspective view of the sheet post-processing apparatus shown in FIG.

FIG. 3 is a partial front view of the sheet post-processing apparatus shown in FIG.

FIG. 4 is a partial perspective view of the sheet post-processing apparatus shown in FIG.

FIG. 5 is a block diagram illustrating a configuration of a control system of the sheet post-processing apparatus illustrated in FIG. 1;

FIG. 6 is an explanatory diagram of a principle in which sheets are sorted by skew discharge in the sheet post-processing apparatus shown in FIG. 1;

FIG. 7 is a perspective view illustrating a configuration example of a sheet discharge mechanism of the sheet post-processing apparatus illustrated in FIG. 1;

8A is a plan view of a main part showing another configuration example of the paper discharge mechanism, and FIG. 8B is a cross-sectional view taken along the line BB of FIG. 8A.

[Explanation of symbols]

Reference Signs List 1 discharge tray, 1a discharge tray edge, 3 discharge roller, 3a discharge roller (drive roller), 3b discharge roller (drive roller), 3c first drive roller, 3d second drive roller, 3 'driven roller, 33A roller Vs. 33
B roller pair, 34 discharge motor, 34A discharge motor, 34B discharge motor, 35a drive shaft, 35b drive shaft, 36a timing belt, 36b timing belt, 33A 'roller pair, 33B' roller pair, 8
0 paper discharge mechanism, 90 paper discharge mechanism, 111a paper, 11
1b paper, 141 electromagnetic solenoid, 142 electromagnetic solenoid, 143 connecting rod, 144 connecting rod, 145
Arm, 146 Arm, 147 Spring, 100
Paper post-processing device, 200 copier, A discharge direction, C
L Center line (reference line).

Claims (5)

[Claims] 1. A sheet post-processing apparatus for sorting and stacking sheets discharged from an image forming apparatus on a sheet discharge tray, wherein the sheet discharge tray has a lifting mechanism for raising and lowering the sheet discharge tray in accordance with the number of stacked sheets. A paper discharge mechanism for discharging the paper onto the paper discharge tray, the paper discharge mechanism comprising: a direct feeding means for discharging the paper straight in the discharge direction; and a paper discharge mechanism for discharging the paper obliquely to the discharge direction. And a skew feeding means for causing the sheet to be post-processed. 2. The direct-feeding means and the skew-feeding means comprise at least two pairs of rollers arranged symmetrically with respect to the center of a sheet discharge path, and drive both roller pairs at the same rotational speed. 2. The sheet post-processing apparatus according to claim 1, wherein the sheet post-processing device functions as the direct feeding device by causing the rotation of both roller pairs to be different from each other. 3. The two roller pairs each include a driven roller and a driving roller that feeds the sheet by rotating the driven roller by sandwiching the sheet between the driven roller. Is provided with a second driving roller having a different diameter in addition to the first driving roller having the same diameter as the driving roller of the other roller pair, and one of the first driving roller and the second driving roller can be selectively contacted with the sheet. The sheet post-processing apparatus according to claim 2, wherein 4. The sheet post-processing apparatus according to claim 1, wherein the sheet discharging mechanism has a function of discharging sheets in different directions with respect to a discharging direction. 5. The sheet post-processing apparatus according to claim 1, further comprising a function of controlling a degree of slanting the sheet with respect to a discharge direction in accordance with a sheet size.