JP4109876B2 - Sheet post-processing device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a sheet post-processing apparatus that is connected to an image forming apparatus and performs a binding process, and a stacking tray and a stacking wall thereof, and more particularly, to an improvement in stackability of a sheet bundle after a binding process due to the shape of the stacking wall. Is.
[0002]
[Prior art]
Conventionally, in a conventional sheet post-processing apparatus that is connected to an image forming apparatus, performs a binding process on received sheets, and stacks a bundle of bound sheets,
When sheets that have been bound are stacked, there is a problem in that the portions that have been subjected to the binding process overlap and rise up from other parts.
[0003]
On the other hand, conventionally, there has been a method of providing a concave portion in the binding needle portion of the stacking tray to absorb the rising of the binding needle portion.
[0004]
This is because the conventional sheet post-processing apparatus is mainly connected to and arranged next to the image forming apparatus, so-called large console type, and there is room in the space below the tray, and the method of providing a recess is used. There were no restrictions on.
[0005]
[Problems to be solved by the invention]
However, in recent years, with an increase in the speed of small and medium-sized image forming apparatuses, as the need for sheet post-processing means increases, a sheet post-processing apparatus that can be mounted on a small and medium-sized image forming apparatus is required.
[0006]
In order to cope with this, the sheet post-processing apparatus is required to be a small-sized type that can be attached to and detached from the upper part of the image forming apparatus instead of the conventional large console type.
[0007]
In the case of sheet post-processing that can be attached to and detached from the upper part of the image forming apparatus, the image forming apparatus itself has a stacking tray below the stacking tray, and if the stacking space is made too high above, the accessibility of the user is deteriorated. , There are spatial constraints above and below.
[0008]
In order to increase the loading capacity in the space limited above and below, it is necessary to raise the full load detection line and to carry the loading to the very vicinity of the discharge roller.
[0009]
However, when the full load detection is raised to the vicinity of the height of the discharge roller, high detection accuracy is required, and due to partial rise of the stacked sheet bundle (for example, partial rise due to overlapping of the binding needle portions) If there is a false detection, the upper part of the stacked sheet bundle is stacked up to the vicinity of the discharge roller before full loading, and there is a problem that the discharge roller and the uppermost stacked sheet bundle interfere with each other.
[0010]
12 and 13 are sectional views of the sheet post-processing apparatus. 12 and 13, the end of the sheet is bound by a binding needle S5a to form a sheet bundle S5. As the number of stacked sheets increases, the sheet bundle S5 overlaps the staples S5a, and only the rear end is raised and stacked.
[0011]
The full load detection flag 122 cannot detect the upper surface of a sheet that is partially raised along the stacking wall 120. Therefore, before the full load is detected as shown in FIG. 13, the discharge roller 106 is contacted or the nip is blocked, and the discharged sheet may be damaged or may cause a jam or the like.
[0012]
On the other hand, as a conventional measure, there is a method of extending the full load detection flag 122 further downward. However, the upper limit line of full load is lowered, and it is not suitable when it is desired to secure the stacking capacity in a limited space like the sheet post-processing apparatus B.
[0013]
Further, a method of providing a hole or a recess for allowing the staple S5a to escape under the stacking tray 107 is also common. However, in the configuration in which the image forming apparatus A is below, the discharge port 104 of the image forming apparatus A is blocked.
[0014]
Further, the sheet near the stacking wall 120 can be detected by curving more toward the stacking wall 120 without extending the full load detection flag 122. However, the sheet is caught when the discharged sheet collides with the full load detection flag 122.
[0015]
SUMMARY OF THE INVENTION An object of the present invention is to provide a sheet post-processing apparatus capable of preventing erroneous detection due to partial swell of stacked sheet bundles and increasing the stacking capacity in a space limited up and down.
[0016]
[Means for Solving the Problems]
In order to solve the above problems, a typical configuration of a sheet post-processing apparatus according to the present invention is a sheet post-processing apparatus that performs binding processing on a sheet received from the image forming apparatus in a sheet post-processing apparatus connected to the image forming apparatus. Means, a discharge means for discharging the sheets subjected to the binding process by the sheet post-processing means, a stacking means for stacking the sheets discharged by the discharge means, and a sheet discharge direction of the sheets stacked on the stacking means A stacking wall formed from the bottom of the discharge unit to the stacking unit so as to contact the rear end, and the stacking wall contacts the discharge unit so as to contact the rear end of the sheets stacked on the stacking unit. and has a projection which projects in a sheet discharge direction downstream side against the projection, the protruding amount to the outer as the sheet discharge direction downstream side in the width direction of the sheets loaded Wherein the increase.
[0017]
DETAILED DESCRIPTION OF THE INVENTION
[First embodiment]
A first embodiment of a sheet post-processing apparatus according to the present invention will be described with reference to the drawings. 1 is a sectional view of a sheet post-processing apparatus and an image forming apparatus according to the present embodiment, FIGS. 2 to 4 are perspective views of the sheet post-processing apparatus and the image forming apparatus, and FIG. 5 is a front view of a stacking wall and a discharge roller. 6 is a top view of the sheet post-processing apparatus, and FIGS. 7 and 8 are cross-sectional views of the sheet post-processing apparatus.
[0018]
As shown in FIG. 2, the sheet post-processing apparatus B discharges a sheet placed on the image forming apparatus A and received from the image forming apparatus A to a stacking tray 7 as a stacking means by a discharge roller 6 as a discharging means. To load. When the sheet post-processing by the sheet post-processing apparatus B is not performed, the sheet S2 is discharged and stacked on the stacking tray 5 from the discharge port 4 of the image forming apparatus A.
[0019]
The sheet post-processing apparatus B includes joggers 8 and 9 and sheet post-processing means 10. The joggers 8 and 9 that align the sheets by moving them in the width direction move in a direction orthogonal to the sheet conveying direction and align the sheets in the direction orthogonal to the conveying direction. A part of the sheet post-processing means 10 that performs the binding process is exposed to the outside so that a needle cartridge can be formed from the outside.
[0020]
As shown in FIG. 3, the joggers 8 and 9 are moved inward to align the sheet S1 in the sheet width direction. Thereafter, the sheet post-processing apparatus 10 performs a binding process on the rear end of the sheet bundle (the upstream end on the right in the sheet conveying direction toward the front). Then, as shown in FIG. 4, the joggers 8 and 9 are opened outward, and the sheet bundle s1 is dropped and stacked on the stacking tray 7.
[0021]
FIG. 1 is a cross-sectional view of the sheet post-processing apparatus. The flow of sheet conveyance and the protrusions on the stacking wall will be described with reference to FIG.
[0022]
The sheet post-processing apparatus B includes an entrance roller 23, an intermediate roller 24, and a discharge roller 6. The sheet post-processing apparatus B includes a simple stacking mode in which received sheets are stacked for each single sheet without performing a binding process, and a post-processing stacking mode in which the received sheets are bound and stacked as a bundle of bound sheets. have.
[0023]
In the simple stacking mode, the discharge roller 6 is always nipped, and the received sheet is conveyed and discharged as it is by the entrance roller 23, the intermediate roller 24, and the discharge roller 6, and sequentially stacked on the stacking tray 7.
[0024]
In the post-processing stacking mode, the discharge rollers 6 are separated to open the nip, and a plurality of sheets are stacked on the intermediate stacking unit 25 until a desired number of sheets is bound. Meanwhile, alignment is performed by the conveyance direction alignment paddle 26 and joggers 8 and 9 which are horizontal alignment means, and the sheet post-processing means 10 performs binding processing to form a sheet bundle. Thereafter, the discharge roller 6 is brought into pressure contact, the sheet bundle is nipped and conveyed, and stacked on the stacking tray 7.
[0025]
A stacking wall 20 is provided under the discharge roller 6, and the stacking wall 20 extends substantially vertically downward from the position immediately below the discharge roller 6 toward the stacking tray 7. Further, the stacking wall 20 does not protrude to the downstream side in the transport direction with respect to the peripheral surface below the discharge roller 6.
[0026]
A protrusion 21 is formed on the upper portion of the stacking wall 20, and the protrusion 21 increases in protrusion amount from the lower side to the upper side, and protrudes downstream from the circumferential direction of the discharge roller 6 in the transport direction.
[0027]
A full load detection flag 22 is provided on the downstream side in the transport direction of the discharge roller 6, and the full load detection flag 22 detects the full height of the sheets or sheet bundles stacked on the stacking tray 7.
[0028]
FIG. 5 is a front view of the stacking wall 20 and the discharge roller 6. As shown in FIG. 5, the discharge roller 6 includes a shaft 6a and a plurality of rollers 6b, and the rollers 6b of the lower discharge roller 6 are alternately arranged with the rollers 6b of the upper discharge roller 6. The bundle is comb-toothed, and the sheet is stiffened and discharged. Further, the rollers at both ends of the lower discharge roller 6 have a conical shape in order to increase the stiffness at both ends of the sheet, and the diameter increases from the center in the width direction of the sheet toward the outside.
[0029]
FIG. 6 is a view of the stacking wall and the discharge roller as viewed obliquely from above. As shown in FIG. 6, the projection amount of the projection 21 increases from the center in the width direction of the stacked sheets toward the outside. Further, the conical extension line 6L of the discharge roller 6 and the protrusion-shaped extension line 21L of the protrusion 21 extend in substantially the same direction, and the protrusion 21 has a shape along the peripheral surface of the conical roller 6b. .
[0030]
FIG. 7 is a diagram showing the stacking wall 20 having the protrusions 21 and the state of stacking. As described above, the protrusion 21 has a shape protruding from the peripheral surface of the discharge roller 6 as it goes above the stacking wall 20 and is continuously formed on the stacking wall 20. In this configuration, as shown in FIG. 7, the bound sheet bundle S5 is stacked along the protrusion 21 to prevent the sheet from contacting the discharge roller 6 or blocking the nip. Then, as shown in FIG. 8, the full load detection flag 22 can be raised to detect the full load.
[0031]
[ First Reference Example ]
For the first reference example follows the sheet over preparative post-processing apparatus will be described with reference to FIG. 9 and 10 are sectional views of the sheet post-processing apparatus according to the first reference example . About the part which overlaps with said 1st embodiment, the same code | symbol is attached | subjected and description is abbreviate | omitted.
[0032]
As shown in FIG. 9A, the sheet post-processing apparatus B includes a protrusion 31, a stacking wall 33, and a stacking tray 7. The protrusion 31 can be projected and retracted at a position indicated by a solid line and a broken line with respect to the stacking wall 33, and the protruding and protruding amount is configured to be variable.
[0033]
FIG. 9B shows a single sheet being discharged from the discharge roller 6. In the sheet post-processing apparatus B, in the single sheet stacking mode, the joggers 8 and 9 are always retracted more than the sheet width. As shown in this figure, after the sheet S6 has landed at the leading edge, S6 to S7 to S8. The rear end loads along the loading wall 33 as shown in FIG. At this time, as described above, the protrusion 31 is movable and stored in the stacking wall 33. As a result, the trailing edge of the sheet being discharged and dropped is not caught by the leading edge 31a of the protrusion 31.
[0034]
In the case of a single sheet that is not subjected to binding processing, even if the stacking is continued sequentially, there is no occurrence of partial bulge (due to overlapping of the binding needles) at the rear end. As shown, the top surface is flat and the full load detection line is reached, and the loading ends normally.
[0035]
FIG. 10 shows the drop stacking in the sheet post-processing mode.
[0036]
In this figure, the sheet is once held at the joggers 8 and 9 and then subjected to a binding process. Then, while being conveyed by the discharge roller 6, the joggers 8 and 9 are opened, and the sheet bundle is moved upward. Then drop and load.
[0037]
In the case of sheet stacking, drop stacking is performed after being held by the joggers 8 and 9, and as shown in FIG. 10A, the sheet bundle drops in a straight line in the order of S9 to S12. At that time, the rear end falls without being along the loading wall. Then, as shown in FIG. 10 (b), the back end is fully loaded due to the overlapping of the binding needle portions. At this time, the protrusion 31 is in the protruding position, and the bound sheet bundle is stacked along the protrusion 31 in the same manner as in the first embodiment to prevent the sheet from contacting the discharge roller 6 or blocking the nip. . Then, the full load detection flag 22 can be raised to detect the full load.
[0038]
Here , switching between single sheet stacking and sheet bundle stacking mode so that the protrusions can be projected and retracted makes it possible to optimally cope with the trailing edge lean of the single sheet and the trailing edge bulge of the binding sheet. Compared to the form, it realizes compatibility with various loading modes.
[0039]
[ Second Reference Example ]
For the second reference example follows the sheet over preparative post-processing apparatus will be described with reference to FIG. FIG. 11 is an explanatory diagram of a sheet post-processing apparatus according to a second reference example . About the part which overlaps with said 1st embodiment, the same code | symbol is attached | subjected and description is abbreviate | omitted.
[0040]
In the sheet post-processing apparatus B in the second reference example, the protrusion 21 according to the first embodiment is a protrusion 51 that is movable in the sheet width direction along the long hole 52.
[0041]
FIG. 11A is a diagram showing the position of the protrusion 51 when stacking wide sheets, and FIG. 11B is a diagram showing the position of the protrusion 51 when stacking narrow sheets. Is configured to be movable to each position.
[0042]
By moving the projection 51 according to the sheet width, the staple 51 can be moved according to the sheet width, and the projection 51 can be surely aligned with the bulging portion of the binding sheet stack even in the post-sheet processing where the binding position moves. Compared with the above-described embodiment, it is possible to cope with various sheet widths.
[0043]
【The invention's effect】
As described above, by providing the protrusion on the stacking wall, the position of the trailing edge of the stacked sheets can be selectively changed depending on the location.
[0044]
Further, the protrusion is protruded from the peripheral surface of the discharge roller, and the protrusion position is provided at a location where the stacking bundle swells by the binding needle. Accordingly, even if the sheet bundle that has been bound and stacked is continuously stacked to near full, it is possible to prevent the trailing edge of the sheet from interfering with the discharge roller.
[0045]
Also, the full load detection line can be pulled up near the discharge roller nip to increase the stacking capacity in the same stacking space, and is installed on the upper part of the image forming apparatus (for example, the image forming apparatus as in this embodiment) that has space restrictions on the top and bottom. Sheet post-processing apparatus).
[0046]
[Brief description of the drawings]
FIG. 1 is a cross-sectional view of a sheet post-processing apparatus and an image forming apparatus according to a first embodiment.
FIG. 2 is a perspective view of a sheet post-processing apparatus and an image forming apparatus.
FIG. 3 is a perspective view of a sheet post-processing apparatus and an image forming apparatus.
FIG. 4 is a perspective view of a sheet post-processing apparatus and an image forming apparatus.
FIG. 5 is a front view of a stacking wall and a discharge roller.
FIG. 6 is a top view of the sheet post-processing apparatus.
FIG. 7 is a cross-sectional view of a sheet post-processing apparatus.
FIG. 8 is a cross-sectional view of a sheet post-processing apparatus.
FIG. 9 is a cross-sectional view of a sheet post-processing apparatus according to a first reference example .
FIG. 10 is a cross-sectional view of the sheet post-processing apparatus.
FIG. 11 is an explanatory diagram of a sheet post-processing apparatus according to a second reference example .
FIG. 12 is a cross-sectional view of a conventional sheet post-processing apparatus.
FIG. 13 is a cross-sectional view of a conventional sheet post-processing apparatus.
[Explanation of symbols]
A ... Image forming apparatus B ... Sheet post-processing devices S1, S2, S6 to S12 ... Sheet S5 ... Sheet bundle S5a ... Binding needle 4 ... Discharge port 5, 7 ... Stack tray 6 ... Discharge roller 6L ... Extension line 6a ... Shaft 6b ... Colo 8, 9 ... Jogger
10 ... Sheet post-processing means
20, 33… Loading wall
21, 31, 51… projection
21L ... extension line
22… Full load detection flag
23… Inlet roller
24… Intermediate roller
25… Intermediate loading section
26… Conveying direction alignment paddle
31a ... tip
52… slot

Claims (3)

In a sheet post-processing apparatus connected to an image forming apparatus,
A sheet post-processing means for performing a binding process on a sheet received from the image forming apparatus;
A discharge means for discharging the sheet subjected to the binding process by the sheet post-processing means;
Stacking means for stacking sheets discharged by the discharging means;
A stacking wall formed from the bottom of the discharge unit to the stacking unit so as to contact the rear end of the sheet stacked in the stacking unit;
The stacking wall has a protrusion protruding downstream in the sheet discharge direction with respect to the discharge unit so as to contact the rear end of the sheet stacked in the stack unit in the sheet discharge direction,
The sheet post-processing apparatus according to claim 1, wherein the protrusion has a larger protrusion amount toward the downstream side in the sheet discharge direction toward the outer side in the width direction of the stacked sheets.   2. The sheet post-processing apparatus according to claim 1, wherein the protrusion increases with an amount of protrusion toward the downstream side in the upper sheet discharge direction.   The discharge means is a pair of discharge rollers composed of a shaft and a roller, and rollers at both ends in the width direction of the discharged sheet of the lower discharge roller of the discharge roller pair are outside the width direction of the sheet. 2. The conical shape which becomes larger as the roller diameter increases, and the protrusions of the stacking wall protrude downstream in the sheet discharge direction along a conical shape extending in the width direction of the rollers at the both ends. The sheet post-processing apparatus as described.

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