Patent Grant
10234808
The present application is based on, and claims priority from, Japanese Application No. JP2015-198682 filed Oct. 6, 2015 the disclosure of which is hereby incorporated by reference herein in its entirety.
Field of the Invention
The present invention relates to a sheet bundle binding device that bundles a plurality of sheets fed from, e.g., an image forming device and automatically performs staple-free binding for the sheet bundle and an image forming system having the sheet bundle binding device.
Description of the Related Art
Recently, in addition to a stapling device that drives a metal needle into a plurality of stacked sheets to bind the sheets, there is used a staple-free binding device that sandwiches a plurality of stacked sheets between a pair of concavo-convex crimping teeth and strongly presses the sheets for pressure bonding to bind the sheets. Both the stapling device and the staple-free binding device have a problem in that when some sheets need to be removed from the bound sheet bundle, the removing operation is very troublesome, and all the sheets of the sheet bundle tend to be separated from each other.
To solve the above problem, there is proposed an image forming device provided with a stapler that drives a staple needle in a sheet bundle stored in a discharge tray and a sewing unit that forms perforation on the sheet bundle at a position surrounding a stable needle driving position. With this configuration, a desired sheet can be cut off along the perforation to be removed from the sheet bundle (see, for example, Patent Document 1). Further, there is known a sheet post-processing that unifies some small group sheet bundles bound by a staple needle driven inside a perforation into a large group sheet bundle and then binds the large group sheet bundle with a staple needle at an outside portion of the perforation. With this configuration, the small group sheet bundle can be cut off along the perforation and removed from the large group sheet bundle (see, for example, Patent Document 2).
In the staple-free binding, when the number of sheets to be bound is increased, a binding force between sheets constituting a sheet bundle is reduced, so that the number of sheets that can be bound in single binding processing is limited. In order to cope with this, there is known a sheet processing device that has a plurality of binding sections that perform staple-free binding for a sheet bundle at different binding positions, wherein a part of a sheet bundle bound at one binding position is bound together with another sheet bundle bound at another binding position so as to increase the number of sheets to be bound (see, for example, Patent Document 3).
Further, there is proposed a sheet bundle binding device provided with both a stapler unit that binds a sheet bundle by driving a staple needle into the sheet bundle and a staple-free binding unit that press-binds a sheet bundle without using a staple needle (see, for example, Patent Document 4 and Patent Document 5). A user can select the staple binding or staple-free binding according to the usage of the sheet bundle.
The devices described in Patent Document 1 and Patent Document 2 need to be provided with a perforation forming unit for forming the perforation on the sheet, in addition to the stapler. This may enlarge the device size and complicate the device configuration and may require control for the device including the perforation forming unit. This not only opposes the miniaturization and speeding-up of the device, which are recently required, but also poses a problem of high price.
Further, as described in Patent Document 3, the sheet processing device having the plurality of binding sections has an enlarged and complicated configuration and thus needs to have a complicated control function for controlling operation of the enlarged and complicated configuration. Besides, in the first place, it is not easy to insert another binding section between the previously bound sheets.
The devices described in Patent Document 4 and Patent Document 5 can only selectively perform staple binding and staple-free binding. Further, these documents neither disclose nor suggest a binding method capable of achieving easy removal of some sheets from the bound sheet bundle and binding of residual sheets with a large binding force.
The present invention has been made in view of the above problems in the conventional technology, and the object thereof is to provide a sheet bundle binding device provided with both a staple binding unit and a staple-free binding unit capable of easily removing some sheets from a bound sheet bundle and an image forming system having the sheet bundle binding device.
To achieve the above object, a sheet bundle binding device according to an aspect of the present invention includes a carry-in port; a processing tray on which sheets carried in through the carry-in port are accumulated; a staple binding unit that binds the sheets accumulated on the processing tray by use of a stable needle; a staple-free binding unit having a pair of crimping toothed parts for staple-free binding the sheets accumulated on the processing tray; and a control section that controls the staple binding unit and the staple-free binding unit in such a way that the staple binding unit binds the sheets accumulated on the processing tray to form a bound first sheet bundle and then the staple-free binding unit binds a second sheet bundle obtained by adding a predetermined number of additional sheets carried in through the carry-in port to the first sheet bundle.
As described above, the first sheet bundle is bound using the staple needle and thus has a large binding force, while the second sheet bundle added with additional sheets and subjected to press-binding has a binding force smaller than that of the first sheet bundle, so that the additional sheets can be easily removed from the second sheet bundle. In addition, unlike the conventional binding device, there is no need of an additional unit such as a perforation forming unit. This prevents an increase in size, weight, and complication of the device to thereby enable cost reduction.
The additional sheets that have been press-bound are highly likely to be removed from the second sheet bundle, while the first sheet bundle that has been staple-bound is highly likely to be used in a bound state. When an image is formed on an opened sheet surface of the first sheet bundle, the second binding part and the binding imprint thereof may impair or adversely affect the image. Even when the image undergoes little influence, remaining of the binding imprint on the opened sheet surface may deteriorate appearance. When the staple-free binding part is present at the opening side of the sheet in opening or turning pages of the first sheet bundle even after removal of the additional sheets, the binding force by the staple-free binding part may obstruct smooth page-opening operation of the first sheet bundle.
Thus, the staple-free binding part of the second sheet bundle bound by the staple-free binding unit is disposed so as to come closer to the side of the second sheet bundle than the staple binding part of the first sheet bundle bound by the staple binding unit comes. With this configuration, even an image is formed on the opened sheet surface of the first sheet bundle, adverse effect that the staple-free binding part and the binding imprint thereof can have on the image can be eliminated or reduced. Further, after removal of the additional sheets from the second sheet bundle, pages of the first sheet bundle can smoothly be opened or turned.
The sheet bundle binding device further includes a sheet bundle carry-out mechanism for carrying out the second sheet bundle from the processing tray, wherein the staple-free binding unit is disposed downstream of the staple binding unit in a direction in which the second sheet bundle is carried out from the processing tray. With this configuration, after the first binding, the first sheet bundle or the second sheet bundle obtained by adding additional sheets on the first sheet bundle can be moved along the sheet bundle carry-out direction of the sheet bundle carry-out mechanism from the staple binding unit to the staple-free binding unit for the second binding, whereby two-stage binding can be performed efficiently.
The sheet bundle binding device further includes a sheet bundle aligning mechanism for aligning the sheets accumulated on the processing tray into a sheet bundle. Thus, all the sheets constituting the first and second sheet bundles can be bound in an aligned state.
The staple binding unit drives the staple needle into the first sheet bundle in such a way that the staple needle is disposed obliquely with respect to the side of the first sheet bundle. Thus, a possibility that the end edge of the first additional sheet is caught by a staple needle slightly protruded from the first sheet bundle upon accumulation of the first additional sheet on the first sheet bundle can be prevented to thereby enable proper sheet accumulation.
According to another aspect of the present invention, there is provided an image forming system including: an image forming unit that forms an image on a sheet; and a sheet bundle binding unit that accumulates a plurality of sheets fed from the image forming unit and applies staple-free binding to the accumulated sheets, the sheet bundle binding unit being any one of the above-described sheet bundle binding devices.
By including the above sheet bundle binding device of the present invention, there can be realized an image forming system that can bind a plurality of sheets on which an image is formed by the image forming unit in two stages of binding the first sheet bundle with a large binding force and binding a second sheet bundle composed of the first sheet bundle and additional sheets added to the first sheet bundle with a small binding force so as to allow the additional sheets to be easily removed from the second sheet bundle.
Hereinafter, a preferred embodiment of the present invention will be described in detail with reference to the accompanying drawings. Throughout the accompanying drawings, the same reference numerals are used to designate the same or similar components.
In the present specification, “sheet bundle offset conveyance” refers to movement (widthwise shifting) of a sheet bundle obtained by accumulating sheets carried in onto a processing tray from a discharge port in a direction perpendicular to (crossing) a sheet conveying direction, and “offset amount” refers to a movement amount of the widthwise shifting. Further, “alignment of sheet bundle” refers to alignment of a plurality of sheets having different sizes carried in onto a processing tray from a discharge port with reference to a predetermined position (for example, “center reference” which is to align the sheets with reference to the center position of the processing tray in a direction perpendicular to the sheet conveying direction (i.e., width direction) or “side reference” which is to align the sheets with reference to one side of the processing tray in the width direction thereof). For example, “to perform offset after aligning the sheets” refers to aligning a plurality of sheets having different sizes with reference to the predetermined position and then moving the aligned sheets to a direction perpendicular to the sheet conveying direction.
A sheet bundle binding device according to the present embodiment can perform binding for a sheet bundle obtained by aligning and accumulating a plurality of sheets on which an image is formed by an image forming system illustrated in
The image forming system of
The image reading unit A includes a platen 1 formed of a transparent glass and a reading carriage 2 that is reciprocated along the platen 1 to read a document image. The document automatic feeding unit D feeds document sheets on a supply tray one by one to the platen 1, and the carriage 2 having a line sensor (photoelectric conversion element) arranged in a document width direction (main scan direction) is reciprocated in a sub scan direction perpendicular to the main scan direction to thereby read the document image in a line order.
The image forming unit B includes a supply section 4, an image forming section 5, and a discharge section 6 which are incorporated in a device housing 3 so as to form an image on a sheet based on image data of the document read by the image reading unit A. The supply section 4 supplies a sheet delivered by a supply roller 8 from a cassette 7 to the image forming section 5 through a supply path 9 according to an image forming timing of the image forming section 5. During the sheet supply operation, the leading end of the sheet is aligned by a resist roller pair 10. The image forming section 5 includes, e.g., an electrostatic image forming mechanism. The image forming section 5 forms a latent image (electrostatic latent image) on a photoconductor drum 11 using a light emitter 12, attaches toner ink to the latent image using a developing unit 13, transfers the toner image onto a sheet using a transfer charger 15, fixes the toner image on the sheet using a fixing unit (heating roller) 16, and feeds the resultant sheet to the discharge section 6. The discharge section 6 guides the image-formed sheet along a discharge path 17 and carries out the sheet to the post-processing unit C through a discharge port 18.
The post-processing unit C includes a sheet bundle binding device 20 according to the present embodiment and has a function of accumulating and aligning a plurality of sheets carried out from the image forming unit B to make them into a sheet bundle, binding the sheet bundle, and storing the sheet bundle in a downstream side stack tray. The post-processing unit C of the present embodiment has a stand-alone structure independent of the image reading unit A and the image forming unit B, and the image reading unit A, image forming unit B, and post-processing unit C are connected by a network cable into one system. As another embodiment, the post-processing unit C may have an inner finisher structure. In this structure, the sheet bundle binding device 20 is incorporated, as a unit, in a sheet discharge space formed inside the device housing 3 of the image reading unit A.
As illustrated in
The discharge path 22 includes a feeder mechanism in which conveying roller pairs such as a carry-in roller pair 31, a discharge roller pair 32, and the like are arranged at predetermined intervals so as to convey a sheet fed from the image forming unit B from a carry-in port 30 to the discharge port 23 in a substantially horizontal direction. Further, along the discharge path 22, sheet sensors Se1 and Se2 for detecting the leading end and/or rear end of a conveyed sheet are arranged.
As illustrated in
The sheet carry-in mechanism 26 includes a conveying roller unit 46 so as to convey a sheet discharged from the discharge port 23 through the level difference d toward the back side of the processing tray 24 in a proper posture, (that is, with the left and right side edges of the sheet conveyed straight in the conveying direction) and smoothly. The conveying roller unit 46 includes a roller pair constituted of an upper conveying roller 48 and a lower driven roller 49 disposed with the processing tray 24 interposed therebetween. The conveying roller 48 is rotatably supported at the leading end of a bracket 50 swingably supported above the processing tray 24. The driven roller 49 is turnably provided at a fixed position immediately below the processing tray 24.
As illustrated in
The sheet carry-in mechanism 26 further includes a raking rotor 36 for guiding a sheet leading end to the regulation member 35 so as to cope with sheet curling or skewing which can occur when a sheet is conveyed to the regulation member 35 on the processing tray 24. The raking rotor 36 is a ring-shaped or short cylindrical belt member disposed above the processing tray 24 and in front of the regulation member 35 so as to be rotatable in the sheet carry-in direction. The belt member is engaged with the upper surface of a new sheet conveyed on the uppermost sheet of a sheet bundle stacked on the processing tray 24 and rotated in the counterclockwise direction in the drawing while pressing the leading end of the new sheet to convey the new sheet until it abuts the regulation face 35a of the regulation member 35.
The sheet aligning mechanism 27 is constituted of a sheet end regulation part 37 and a side aligning mechanism 38. The sheet end regulation part 37 has the above-mentioned regulation member 35 to regulate the carry-in direction (or carry-out direction) position of a sheet carried in onto the processing tray 24 from the discharge port 23 at the leading of the sheet in the carry-in direction (or rear end of the sheet in the carry-out direction). The side aligning mechanism 38 moves a sheet and a sheet bundle on the processing tray 24 in a direction perpendicular to the carry-in (or carry-out) direction, i.e., in the width direction to regulate the width direction position of the sheet or sheet bundle at the side end edge thereof to thereby align the sheet or sheet bundle in the width direction.
As illustrated in
The side aligning members 39 and 40 are connected respectively to movable support parts 41 and 42 disposed on the back surface side of the processing tray 24 through width direction linear slits (not illustrated) formed penetrating the processing tray 24. By individually turning pinions 43 and 44 meshing respectively with racks 41a and 42a formed in the respective support parts 41 and 42 by respective driving motors M1 and M2, the side aligning members 39 and 40 can be moved independently of each other in the direction approaching each other or separating from each other and stopped at desired width direction positions. Thus, it is possible to individually set the positions of the side aligning members 39 and 40 in accordance with the size of a sheet to be carried in the processing tray 24 and, when a sheet bundle is moved in the width direction (offset conveyance), the positions and offset amounts thereof can be determined.
As illustrated in
The conveying roller unit 46 has a configuration in which the conveying roller 48 and the driven roller 49 sandwich the sheet bundle Sb from above and below near the front end of the processing tray 24 in the carry-out direction so as to be capable of conveying the sheet bundle Sb. In the conveying roller unit 46, left and right two pairs of rollers (conveying roller 48 and driven roller 49) are arranged symmetrically with respect to the center reference line Sx.
When a bound sheet bundle Sb is carried out from the processing tray 24 to the stack tray 25, the regulation face 35a of the regulation member 35 is made to abut against the rear end of the sheet bundle Sb in the carry-out direction, as illustrated in
Then, the conveying roller 48 is rotated by, e.g., a drive motor (not illustrated) in the clockwise direction in the drawing to convey the sheet bundle Sb in the carry-out direction to thereby carry out the sheet bundle Sb on the processing tray 24 to the stack tray 25, as illustrated in
The binding mechanism 28 includes a staple binding unit that binds a sheet bundle using a staple needle and a staple-free binding unit 51 that binds a sheet bundle without a staple needle. When binding is performed in two stages of the proper binding and temporary binding, the proper binding is performed by using the staple binding unit 70, and the temporary binding is performed by using the staple-free binding unit 51. However, when the number of sheets to be bound is small, the proper binding can be performed by using the staple-free binding unit 51.
As illustrated in
The staple-free binding unit 51 is disposed slightly downward of the staple binding unit 70 in the sheet carry-out direction. Thus, a binding position Ep2 of the staple-free binding unit 51 is set immediately outside the corner 24b of the processing tray 24, so that the staple-free binding unit 51 can bind the sheet bundle Sb2 at a corner on the same side as that in the case of the staple binding.
The staple-free binding unit 51 according to the present embodiment is constituted of a crimping mechanism that presses a sheet bundle between crimping toothed parts each having a concave-convex surface into deformation to thereby bind the sheet bundle. As illustrated in
As illustrated in an enlarged manner in
With this configuration, a corner Sc of a sheet bundle Sb held and pressed between the upper crimping toothed part 55 and the lower crimping toothed part 54 can be deformed into a wave-plate shape in cross section as illustrated in
In the present embodiment, the protrusions 55a and 54a each have a linear ridge line extending perpendicular to the teeth arrangement direction. Alternatively, the ridge line of the projection may be inclined relative to the teeth arrangement direction. Further alternatively, the ridge line may be formed into various shapes other than the linear shape, such as a bent or curved shape. In such a case, the binding part Sc is formed into various wave-plate shapes corresponding to the shapes of the protrusions 55a and 54a.
The movable frame member 53 integrally has a follower roller 56 at the end portion thereof on the opposite side to the upper crimping toothed part 55 with respect to the spindle 53a. The base frame member 52 integrally has a drive cam 57 which is an eccentric cam at the end portion thereof on the opposite side to the lower crimping toothed part 54. The follower roller 56 is disposed in such a way that a follower surface thereof is engaged with a cam surface of the drive cam 57.
An unillustrated spring member is disposed between the base frame member 52 and the movable frame member 53. The spring member biases the upper crimping toothed part 55 and the lower crimping toothed part 54 in such a direction that they are separated from each other, that is, in such a direction that the follower surface of the follower roller and the cam surface of the drive cam 57 are constantly engaged with each other. Therefore, when the drive cam 57 is driven by a motor M4, the movable frame member 53 is swung about the spindle 53a following the cam surface. With this configuration, the upper crimping toothed part 55 and the lower crimping toothed part 54 can be driven in such a way that they are engaged/brought into pressure contact with each other or separated from each other.
The presence of the spring member disposed between the base frame member 52 and the movable frame member 53 allows for a smooth and quick operation to separate the upper crimping toothed part 55 and the lower crimping toothed part 54 from a position where the bound sheet bundle is held under pressure. Further, the base frame member 52 may be provided with an unillustrated position sensor so as to detect whether the upper crimping toothed part 55 and lower crimping toothed part 54 are situated at the pressure-contact position or separated position. By receiving a signal representing a relative positional relationship between the upper crimping toothed part 55 and the lower crimping toothed part 54 from the position sensor, it is possible to perform peeling-off of the bound sheet bundle from the crimping toothed parts more smoothly and efficiently.
The main body control section 60 includes a print control section 62, a sheet feed control section 63, and an input section 65 connected to a control panel 64. The input section 65 can set an image forming mode and a post-processing mode through the control panel 64. In the image forming mode, printing modes such as color/monochrome printing and duplex/single-sided printing, and image forming conditions such as a sheet size, a sheet type, the number of print copies, and enlarged/reduced printing are set.
The post-processing mode includes a printout mode and a binding mode. The binding mode includes a normal mode in which only the proper binding is performed and a two-stage mode in which the proper binding and temporary binding are performed. When the printout mode is selected, a sheet discharged from the discharge port 23 is stored in the stack tray 25 through the processing tray without being subjected to binding. In this case, sheets sequentially fed from the discharge port 23 can be stacked and accumulated on the processing tray 24 and then collectively carried out onto the stack tray 25 in response to a job end signal from the main body control section 60.
In the binding mode, a predetermined number of sheets discharged from the discharge port 23 are stacked and accumulated on the processing tray 24 into a bundle, then subjected to binding in the normal mode or two-stage mode, and carried out onto the stack tray 25. In the two-stage mode, the main body control section 60 transfers, to the binding control section 61, information indicating that the two-stage post-processing mode has been selected and, further, information such as the number of sheets constituting a sheet bundle to be subjected to first binding (proper binding), the number of sheets to be added for second binding (temporary binding) to the sheet bundle that has been subjected to the first binding, the number of sheet bundles to be prepared, and a thickness of a sheet to be image-formed. Further, every time the image formation onto each sheet is ended, the main body control section 60 transfers the job end signal to the binding control section 61.
The binding control section 61 operates the post-processing unit C according to the setting of the post-processing mode input through the input section 65 of the main body control section 60. The binding control section according to the present embodiment includes a control CPU as a control unit. The control CPU is connected with a ROM 67 and a RAM 68. A sheet bundle binding operation and a sheet bundle discharge operation by the post-processing unit C are executed based on a control program stored in the ROM 67 and control data stored in the RAM 68. Thus, the control CPU 66 is connected to drive circuits of all the respective drive motors provided in the post-processing unit C.
When the two-stage binding mode is selected, the binding control section 61 moves the left-side aligning members 39 on the staple-free binding unit 51 side to a retreated position (denoted by a continuous line in
A process from the above standby state to when a sheet bundle is stored on the processing tray 24 and subjected to the first binding will be described using
After the conveyance of the sheet Sh1 is stopped by the regulation member 35, the binding control section 61 moves inward the left- and right-side aligning members 39 and 40 situated at their respective retreated positions of
The above process illustrated in
Thus, the first sheet bundle Sb1 is positioned at a first binding position at which the corner Sc to be subjected to the proper binding completely includes the first binding position Ep1. Then, the binding control section 61 issues a command signal that causes the staple binding unit 70 to execute the first binding. After the binding, the staple binding unit 70 issues a binding end signal to the binding control section 61.
Upon reception of the binding end signal from the staple binding unit 70, the binding control section 61 performs the second binding for temporary binding of additional sheets with the first sheet bundle Sb1 that has been subjected to the proper binding.
As illustrated in
After the carry-in of the additional sheet Sh2 is stopped by the regulation member 35, the binding control section 61 moves inward the left- and right-side aligning members 39 and 40 from their respective retreated positions of
The above process illustrated in
Then, the binding control section 61 does not return the left- and right-side aligning members 39 and 40 to their respective retreated positions but drives the conveyer unit 45 to move the regulation member 35 as the push-out member in the carry-out direction with the second sheet bundle Sb2 sandwiched between the left- and right-side aligning members 39 and 40 from both sides thereof to push out the second sheet bundle Sb2 in the carry-out direction by a predetermined distance. The regulation member 35 is stopped so that the rear end edge of the second sheet bundle Sb2 in the sheet carry-out direction is situated at the position slightly rearward of the second binding position Ep2 in the carry-out direction.
Further, with the second sheet bundle Sb2 sandwiched between the left- and right-side aligning members 39 and 40 from both sides thereof, the binding control section 61 offset-moves the left- and right-side aligning members 39 and 40 in the width direction toward the second binding position Ep2. The left- and right-side aligning members 39 and 40 are stopped so that the side end edge of the second sheet bundle Sb2 on the device rear side slightly exceeds the second binding position Ep2 in the width direction. Thus, as illustrated in
Then, the binding control section 61 issues a command signal that causes the staple-free binding unit 51 to execute the second binding (staple-free binding). In response to the command signal, the staple-free binding unit 51 presses and deforms the corner Sc of the second sheet bundle Sb2 into the wave-plate shape of
On the other hand, at the second binding part PB2, the sheets are subjected to the press-binding, so that the binding force at the second binding part PB2 is smaller than that at the first binding part PB1, so that the additional sheets Sh2 can be easily removed from the second sheet bundle Sb2.
As illustrated in
In general, when a certain number of sheets are pressed and bound with the same pressure, a binding force for binding the sheet bundle is increased/decreased depending on the size of an area of the binding part. Thus, the second binding part PB2 can be formed in such a way that the upper crimping toothed part 55 and lower crimping toothed part 54 cross the side edge of the second sheet bundle Sb2 so that the second sheet bundle Sb2 are pressed and bound not over the entire range of the upper crimping toothed part 55 and lower crimping toothed part 54 but in a partial range thereof. Thus, the binding force at the second binding part PB2 is made smaller, so that the additional sheets Sh2 can be removed from the second sheet bundle Sb2 more easily.
Further, it is possible to adjust the binding force at the second binding part PB2 by increasing/decreasing a pressurizing force between the upper and lower crimping toothed parts of the staple-free binding unit 51 in accordance with the number of sheets of a sheet bundle and/or the number of additional sheets. The increase/decrease in the pressuring force of the staple-free binding unit 51 is controlled by the binding control section 61.
Further, it is easier to peel off the sheet in an arrangement direction of the waves of the wave-plate shape of the staple-free binding (press-binding) part than to peel off the sheet in a direction along the ridge line of the waves. Thus, by forming the stable-free binding part such that the wave ridge line direction substantially coincides with an acting direction of the sheet peeling-off operation, the sheet is not peeled off easily. Conversely, by forming the staple-free binding part such that the wave ridge line direction crosses (especially, crosses at right angles) the acting direction of the sheet peeling-off operation, the sheet can be peeled off from the sheet bundle comparatively easily.
For example, when the staple-free binding part is disposed at a corner of the sheet bundle, an operation of turning pages of the sheet bundle may often be conducted diagonally from its diagonally opposite corner. In the present embodiment, as illustrated in
The same is applied to a case where the staple-free binding part is formed along the side edge of the sheet bundle. For example, when the staple-free binding parts are disposed along the left long sides of the sheet bundles Sb and Sb2, the page-turning operation may be conducted from the right to the left in general. Therefore, when the staple-free biding part is formed in such a way that the wave arrangement direction substantially coincides with the long side direction of the sheet bundle, the sheet is not peeled off easily by a normal page-turning operation; on the other hand, by intentionally peeling off the sheet in the direction crossing the direction of the normal page-turning operation, the sheet can be removed from the sheet bundle easily.
Further, it is found that when an end portion of the staple-free binding part in the wave arrangement direction contacts the side edge of the sheet bundle, the sheet is not peeled off easily even when the page turning operation is conducted along the wave arrangement direction. Thus, the staple-free binding part is formed in such a way that the end portion thereof in the wave arrangement direction contacts the edge of the side from which the pages of the sheet bundle are often turned, the sheet is not peeled off easily by a normal page-turning operation; on the other hand, by intentionally peeling off the sheet in a direction opposite to or crossing the direction of the normal page-turning operation, the sheet can be removed from the sheet bundle easily.
Thus, even when the second sheet bundle Sb2 is press-bound over the entire range of the upper crimping toothed part 55 and lower crimping toothed part 54 as in the above embodiment, the second binding part PB2 is formed in such a way that the end portion thereof in the wave arrangement direction contacts the side of the second sheet bundle Sb2. With this configuration, the additional sheet Sh2 is not peeled off easily by a normal page-turning operation conducted from the lower short side toward the upper short side, but can be removed from the second sheet bundle Sb2 easily by intentionally peeling the additional sheet Sh2 in a direction opposite to or crossing the direction of the normal page-turning operation.
Further, when a binding imprint of the second binding part PB2 remains on an opened sheet surface of the first sheet bundle Sb1 after removal of the additional sheets Sh2 from the second sheet bundle Sb2, there may occur not only appearance deterioration, but also some adverse effect, such as deterioration in quality of an image formed on that surface. Further, when the second binding part PB2 is present at the opening side of the sheet, the binding force by the second binding part PB2 may obstruct smooth page-turning or opening operation of the first sheet bundle Sb1 even after the removal of the additional sheets.
Thus, the second binding part PB2 preferably comes closer to the side of the second sheet bundle Sb2 in proximity to the first binding part PB1 than the first binding part PB1 comes. Thus, after removal of the additional sheets Sh2 from the second sheet bundle Sb2, the first sheet bundle Sb1 can smoothly be opened or turned without being obstructed by the second binding part PB2 and the binding imprint thereof.
In the present embodiment, as illustrated in
After the second binding illustrated in
Further, the binding control section 61 rotates the two conveying rollers 48 to convey the second sheet bundle Sb2 in the carry-out direction from the processing tray 24 to the stack tray 25, as illustrated in
At this time, as illustrated in
While the present invention has been described in connection with preferred embodiments, it is not limited thereto. It will be apparent that various modifications and changes can be made thereto within the technical scope of the invention. For example, although the staple-free binding unit is fixed to a predetermined position with respect to the processing tray in the above-described embodiment, it may be movably provided with respect to the processing tray. Further, the first and/or second binding positions with respect to the processing tray and the positions of the staple binding unit and the staple-free binding unit with respect to the processing tray may be set to different positions from those described in the above embodiment.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2015-198682 | Oct 2015 | JP | national |
| Number | Name | Date | Kind |
|---|---|---|---|
| 20150117983 | Kubota | Apr 2015 | A1 |
| 20160159605 | Miyahara | Jun 2016 | A1 |
| 20160194173 | Okada | Jul 2016 | A1 |
| Number | Date | Country |
|---|---|---|
| H09-315669 | Dec 1997 | JP |
| 2012-121711 | Jun 2012 | JP |
| 2014-172693 | Sep 2014 | JP |
| 2015-013725 | Jan 2015 | JP |
| 2015-016970 | Jan 2015 | JP |
| Number | Date | Country | |
|---|---|---|---|
| 20170097603 A1 | Apr 2017 | US |
