The present application claims priority to and incorporates by reference the entire contents of Japanese Patent Application No. 2009-239356 filed in Japan on Oct. 16, 2009 and Japanese Patent. Application No. 2010-128037 filed in Japan on Jun. 3, 2010.
1. Field of the Invention
The present invention relates to a bookbinding system including a back portion forming device that stitches and folds sheet-like recording medium, such as sheets, recording sheets, and transfer sheets (hereinafter, simply referred to “sheets”), on which images are formed, and makes the back portion of a stitched sheet bundle flat; a bookbinding method performed by the bookbinding system; and a bookbinding control program for performing the bookbinding method with a computer.
2. Description of the Related Art
There has been widely known a sheet processing device that is disposed at a rear portion of a main body of an image forming apparatus, and performs post-processing such as stitching on sheets to be output. However, the number of functions of the sheet processing device has been increased in recent years, so that not only side stitching but also saddle stitching are prevalent. Accordingly, a technique, which improves the folding quality of a booklet subjected to saddle stitch and folding, has been proposed as means for improving output quality.
For example, when a sheet bundle is saddle-stitched and center-folded (two-folded), the two-folded sheet bundle is swelled in a thickness direction near the folded portion thereof, which tends to deteriorate the appearance. Further, if the sheet bundle is swelled near the folded portion thereof, the back portion of the booklet becomes thick and an edge thereof becomes thin. Accordingly, when sheet bundles are stacked in the same direction, the stacked sheet bundles are apt to incline as the number of stacked sheet bundles increase. For this reason, if a plurality of sheet bundles is stacked, the inclination increases, so that the stacked sheet bundles collapse. Therefore, it is difficult to stack more than a certain number of sheet bundles. That is, there is a very high demand on the reduction of the folding height (swelling) after bookbinding in the saddle stitching that is widely used in the world as simple bookbinding. In general, several tens bound booklets are generally handled, that is, transported or delivered while being stacked. However, since the bound booklet, which is subjected to saddle stitching as described above, is swelled, only a small number of booklets may be merely stacked.
In contrast, if a booklet is formed by making the folded portion of a two-folded sheet bundle flat in the shape of a spine of a book, swelling of the booklet is pressed. Accordingly, it may be possible to stack a large number of booklets. That is, if only several booklets, which are swelled as described above, are stacked on the table, the stacked booklets collapse, which causes a problem in the handling of the booklets such as storing or transport. However, if a back portion corresponding to the folded portion is made flat, it may be possible to suppress swelling as much as possible and the above-mentioned problem is solved. Meanwhile, the back portion, which is mentioned here, means a back surface section (hereinafter, referred to as a back surface portion) that includes a back cover forming a back surface and front and back cover sections connected to the spine, and corresponds to a portion opposite to the edge of the booklet.
As user's countermeasures, there have been proposed a plurality of additionally folding mechanisms, such as a method of placing and leaving weights on booklets, a mechanism for performing folding several times, a mechanism for performing an additional folding by making a pressurizing roller run on a folded portion, and a mechanism for clamping a front end of a booklet and forming a plane at a folded portion with a back surface pressure roller.
Among these proposed mechanisms, for example, in the invention disclosed in Japanese Patent Application Laid-open No. 2001-260564, front and back surfaces of a booklet, which is formed of a sheet bundle of which a back portion is folded so as to be curved, are gripped and fixed with pressing means so as to be adjacent to a back portion, and a shaping roller presses a protruding back portion with pressure enough to make the curve of the back portion flat and runs on the back portion one time or several times in a longitudinal direction of the back portion, so that the back portion is made flat.
An advantage of making the curve of the back portion flat is obtained in this invention. However, since the back portion is locally and continuously pressed with a pressurizing roller and a plane is formed at the booklet back portion, wrinkles, breakage, or the like might be generated on the back surface or a stitched portion. Further, since the roller is moved along the folded portion, working time is inevitably lengthened.
Further, a sheet bundle forming device, which is disclosed in the invention disclosed in Japanese Patent Application Laid-open No. 2007-237562, includes clamping means, back portion pressing means, and compression means. The clamping means clamps a portion of a folded sheet bundle except for the periphery of the back portion of the folded sheet bundle in a thickness direction. The back portion pressing means presses the back portion in a direction toward an edge, opposite side of the back portion, by pressing a back portion pressing surface against the back portion of the clamped sheet bundle. The back portion pressing surface is formed at a back portion pressing member. The compression means shapes the periphery of the back portion of the sheet bundle by compressing the periphery of the back portion of the pressed sheet bundle in the thickness direction. In the invention of Japanese Patent Application Laid-open No. 2007-237562, portions of the front and back covers near the folded portion, which is pressed in the direction toward the edge with the back portion pressing means to be swelled, are shaped by compression with the compression means; and swelling is suppressed. That is, it may be possible to suppress the influence on the back portion, which is caused by the forming, as compared to the case where a member in the conventional technology is moved along the back portion while being pressed against the back portion with high pressure. Further, a recess is formed on an abutting surface of a sheet back surface abutting means, in order to remove the influence on the high protrusion from the sheet back surface, such as a loop stitcher.
In contrast to the invention disclosed in Japanese Patent Application Laid-open No. 2001-260564, in the invention disclosed in Japanese Patent Application Laid-open No. 2007-237562, it may be possible to form a plane at the booklet back portion without generating serious problems, such as wrinkles or breakage, on the back surface, the stitched portion, or the like. However, in terms of working time, a plurality of means, such as the clamping means, the back portion pressing means, and the compression means, needs to be sequentially operated after the booklet is abutted on the abutting plate and stopped. For this reason, an effect of reducing working time has been insufficient.
Further, in the saddle-stitching and center-folding of a booklet in the conventional technology, a pressurizing force of the folding rollers has been increased for the purpose of reducing the swelling of a booklet or an additionally folding roller has been disposed on the downstream of the folding rollers and an additional folding has been performed, so that the folded portion of the booklet has been pressurized and the swelling of the booklet is reduced. However, in this case, in forming a plane at the back portion of the booklet, the booklet needs to be swelled in the conveying passage. Accordingly, when the reducing the swelling of the folded portion of the booklet has been performed, the booklet is hardly swelled in the forming the plane at the back portion of the booklet, which is disadvantageous in back surface forming.
However, in outputting a booklet that does not need a process of forming the plane at a back portion of a booklet, a pressurizing force of the folding rollers is increased as the present conditions so as to reduce the swelling of the booklet. Alternatively, an additional folding roller and the like are disposed on the downstream of the folding rollers, so that the folded portion of the booklet is pressurized and the swelling of the booklet is reduced. Therefore, the optimum shape of the saddle-stitched and center-folded booklet is varied based on whether a plane is formed or not at the back portion of the booklet.
A problem to be solved by the present invention is: to form an optimum saddle-stitched and center-folded booklet (sheet bundle), respectively, regardless a plane forming process is performed or not at a back portion of a booklet; and to make it capable of forming a plane at a back portion of a booklet.
Meanwhile, in the embodiment to be described below, center folding means corresponds to a folding plate 215 and first folding rollers 230; additionally folding means corresponds to an additionally folding roller 520 or second folding rollers 233; sheet processing device corresponds to a sheet post-processing device 1 and a saddle-stitching device 2; back portion forming device corresponds to reference numeral 3; back surface forming means corresponds to upper and lower assistant clamping plates 320 and 321, upper and lower pressurization clamping plates 325 and 326, an abutting plate 330, and an abutting surface 330a; control means corresponds to CPUs 3-1 and 100-1; conveying means corresponds to upper and lower conveying belts 311 and 312; abutting means corresponds to an abutting plate 330; first clamping means corresponds to upper and lower assistant clamping plates 320 and 321; second clamping means corresponds to upper and lower pressurization clamping plates 325 and 326; sheet ejection means corresponds to a sheet ejection guide plate 335 and upper and lower sheet ejecting rollers 340 and 341; edge cutting means corresponds to an edge cutting device 4; saddle-stitching means corresponds to a saddle-stitching stapler S1; integration means corresponds to a saddle-stitching tray G; and a computer resource corresponds to a CPU, a ROM, and a RAM.
It is an object of the invention to at least partially solve the problems in the conventional technology.
According to an aspect of the present invention, a bookbinding system includes: a center folding unit configured to perform center folding on an integrated sheet bundle; an additionally folding unit configured to additionally perform folding of a folded portion of the center-folded sheet bundle; a back surface forming unit configured to form a back surface on the sheet bundle by pressing a front end of the folded portion of the center-folded sheet bundle and both surfaces of the sheet bundle; and a control unit configured to change the content of additionally folding according to whether to perform the back surface forming or not.
According to another aspect of the present invention, a bookbinding method for bookbinding a sheet bundle includes: performing center folding of an integrated sheet bundle; performing additionally folding of a folded portion of the center-folded sheet bundle; and performing back surface forming on the sheet bundle by pressing a front end of the folded portion of the center-folded sheet bundle and both surfaces of the sheet bundle, the content of the second step is changed according to whether to perform the back surface forming or not.
The above and other objects, features, advantages and technical and industrial significance of this invention will be better understood by reading the following detailed description of presently preferred embodiments of the invention, when considered in connection with the accompanying drawings.
According to the present invention, conveying means, a conveying guide plate, assistant clamping means, pressurization clamping means, and abutting means are disposed in the above-described order from the upstream. A saddle-stitched booklet, which is conveyed by the conveying means, abuts on the abutting means positioned on the most downstream side, so that the booklet is swelled, stopped, and held in the conveying passage. When pressurizing is performed while a gap is reduced in the order of the conveying guide plate, the assistant clamping means, and the pressurization clamping means on the upstream side, swelling is sequentially concentrated on the downstream side. Then pressure clamping is performed by the pressurization clamping means while a front end portion of a booklet is finally pressed against the abutting means. Accordingly, when a plane is formed at a back portion of a booklet, the control of additionally folding is changed according to whether to perform back portion forming. Meanwhile, in this specification, among sheet bundles, a stitched and saddle-stitched sheet bundle, that is, a bound sheet bundle is particularly referred to as a booklet.
An embodiment of the invention will be described below with reference to drawings. Meanwhile, in the following description, equivalent components are denoted by the same reference numerals and the repeated description will be appropriately omitted.
An image forming apparatus forms a visible image on a sheet-like recording medium on the basis of input image data or the image data of a read image and corresponds to, for example, a copy machine, a printer, a facsimile, and a digital complex machine (MFP 100, see
A branching claw 202 is provided on the downstream side of the inlet rollers 201 of the inlet conveying passage 241. The branching claw 202 is installed in a horizontal direction in
The center folding conveying passage 243 includes an upper-bundle-conveying-guide-plate 207 that is provided above a folding plate 215 for performing center folding and guides a sheet bundle, and a lower-bundle-conveying-guide-plate 208 that is provided below the folding plate 215 and guides a sheet bundle. Upper bundle conveying rollers 205, a rear-end tapping claw 221, and lower bundle conveying rollers 206 are provided at the bundle conveying guide plate 207 in the above-described order from above. The rear-end tapping claw 221 is fixed to a rear-end tapping claw driving belt 222, which is driven by a drive motor (not shown), so as to be perpendicular to the rear-end tapping claw driving belt. The rear-end tapping claw 221 performs an operation for aligning the sheet bundle by tapping (pressing) the rear end of the sheet bundle toward a movable fence to be described below through the reciprocating rotation of the driving belt 222. Further, when a sheet bundle is carried and when a sheet bundle is lifted up for the center folding, the rear-end tapping claw 221 is retracted from the center folding conveying passage 243 of the upper-bundle-conveying-guide-plate 207 to a position shown by a broken line of
A saddle-stitching stapler S1, saddle-stitching jogger fences 225, and a movable fence 210 are provided at the lower-bundle-conveying-guide-plate 208 in the above-described order from above. The lower-bundle-conveying-guide-plate 208 is a guide plate for receiving a sheet bundle that is conveyed through the upper-bundle-conveying-guide-plate 207. The pair of saddle-stitching jogger fences 225 is installed in a width direction of the lower-bundle-conveying-guide-plate 208, and the movable fence 210 where a front end of the sheet bundle is abutted (supported) is provided below the lower-bundle-conveying-guide-plate 208 so as to be vertically movable.
The saddle-stitching stapler S1 is a stapler that stitches the middle portion of a sheet bundle. The movable fence 210 vertically moves while supporting the front end portion of a sheet bundle, and positions the middle portion of the sheet bundle at a position facing the saddle-stitching stapler S1. Then, stapling, that is, saddle stitching is performed at the position. The movable fence 210 is supported by a movable fence driving mechanism 210a, and is movable to the lowest position from the position of a movable fence HP sensor 292 that is shown on the upper side. With respect to the movable range of the movable fence on which the front end of a sheet bundle is abutted, a processable stroke is secured between the maximum size and the minimum size that may be processed by the saddle-stitching device 2. Meanwhile, for example, a rack-and-pinion mechanism is used as the movable fence driving mechanism 210a.
The folding plate 215, a pair of folding rollers (first folding rollers) 230, a sheet ejection conveying, passage 244, and the lower sheet ejecting rollers 231 are provided between the upper and lower bundle-conveying-guide-plates 207 and 208, that is, at the substantially middle portion of the center folding conveying passage 243. The folding plate 215 is reciprocally movable in the horizontal direction in the drawings. Accordingly, a nip between the pair of folding rollers 230 is positioned in an operating direction when the folding plate performs a folding operation, and the sheet ejection conveying passage 244 is formed on the extension of the operating direction. The lower sheet ejecting rollers 231 are provided at the most downstream portion of the sheet ejection conveying passage 244, and eject a folded sheet bundle to the rear side.
A sheet bundle detecting sensor 291 is provided at the lower end of the upper-bundle-conveying-guide-plate 207, and detects the front end of a sheet bundle that is carried into the center folding conveying passage 243 and passes through a center folding position. Further, a folded portion passing sensor 293 is provided at the sheet ejection conveying passage 244. The folded portion passing sensor 293 detects front end of the center folded sheet bundle, and recognizes the passage of a sheet bundle.
Generally, in the saddle-stitching device 2 that has the structure shown in
A sheet bundle SB, which is carried into the center folding conveying passage 243, is conveyed downward in the center folding conveying passage 243 by the inlet rollers 201 and the upper bundle conveying rollers 205, and the detecting sensor 291 confirms the passage of the sheet bundle passes. After that, as shown in
In this state, when the clamping pressure of the lower bundle conveying rollers 206 is released (in a direction of an arrow “a”) as shown in
After that, an operation for aligning the sheet bundle in the width direction (a direction orthogonal to the sheet conveying direction) is performed by the saddle-stitching jogger fences 225 and an operation for aligning the sheet bundle in the conveying direction is performed by the movable fence 210 and the rear-end tapping claw 221, so that an operation for aligning the sheet bundle SB in the width direction and the conveying direction is completed. In this case, after the pushing distances of the rear-end tapping claw 221 and the saddle-stitching jogger fences 225 are changed to optimum values according to information on the size of a sheet, information on the number of sheets of the sheet bundle, and information on the thickness of the sheet bundle, the rear-end tapping claw and the saddle-stitching jogger fences align the sheet bundle.
Further, since a space in the conveying passage is reduced if the bundle is thick, the bundle may not often be completely aligned by one alignment operation. Accordingly, the number of times of alignment is increased in this case. As a result, it may be possible to achieve a well-aligned state. Furthermore, as the number of sheets is increased, time taken to sequentially superimpose sheets on the upstream side is increased. Accordingly, time, which elapses until the next sheet bundle SB is received, is lengthened. As a result, since there is no time loss in the system even though the number of times of alignment is increased, it may be possible to efficiently achieve a well-aligned state. Accordingly, it may be possible to control the number of times of alignment according to the processing time on the upstream.
Meanwhile, the waiting position of the movable fence 210 is generally set to a position where the saddle-stitching position of the sheet bundle SB faces the stitching position of the saddle-stitching stapler S1. The reason for this is that it may be possible to perform stitching at the stacked position without moving the movable fence 210 to the saddle-stitching position of the sheet bundle SB if alignment is performed at this position. Accordingly, at the waiting position, a stitcher of the saddle-stitching stapler S1 is driven to the middle portion of the sheet bundle SB in a direction of an arrow “b” and stitching is performed between a clincher and the stitcher, so that the sheet bundle SB is saddle-stitched.
Meanwhile, the movable fence 210 is positioned by a pulse control that is output from the movable fence HP sensor 292. The rear-end tapping claw 221 is positioned by a pulse control that is output from the rear-end tapping claw HP sensor 294. The control of the positioning of the movable fence 210 and the rear-end tapping claw 221 is performed by a CPU 2-1 (see
Along with the upward movement of the movable fence 210 while the pressurization of the lower bundle conveying rollers 206 is released as shown in
When the sheet bundle SB reaches the position illustrated in
The sheet bundle SB of which the middle portion is two-folded in the state of
The conveying unit includes upper and lower conveying belts 311 and 312, the assistant clamping unit includes upper and lower conveying guide plates 315 and 316 and upper and lower assistant clamping plates 320 and 321, the pressurization clamping unit includes upper and lower pressurization clamping plates 325 and 326, the abutting unit includes an abutting plate 330, and the sheet ejecting unit includes a sheet ejection guide plate 335 and upper and lower sheet ejecting rollers 340 and 341. Meanwhile, each of the units has a width that is equal to or larger than at least the width of the sheet bundle SB in a direction perpendicular to the plane of
The upper and lower conveying belts 311 and 312 are stretched between driving pulleys 311b and 312b and driven pulleys 311c and 312c, respectively, and are driven by a drive motor (not shown). The driving pulleys 311b and 312b are pivotally supported by rotation fulcrums 311a and 312a, respectively. The driven pulleys 311c and 312c are positioned on the downstream side of the driving pulleys 311b and 312b, and face, each other with a conveyance center 301 interposed therebetween. The conveyance center 301 is set on the extension of a line that connects the folding plate 215, the nip between the pair of folding rollers 230, and the nip between the lower sheet ejecting rollers 231. The rotation'fulcrums 311a and 312a support the upper and lower conveying belts 311 and 312 so that a gap between the driven pulleys 311c and 312c may be varied in accordance with the thickness of the sheet bundle SB.
Links 313, which are formed of two members rotatably connected to each other by a connecting shaft 313a, are connected to rotating shafts of the driven pulleys 311c and 312c. An elastic force is applied to the links by a pressurizing spring 314 so that the links always approach each other. The connecting shaft 313a is movable along a long hole 313b, which is formed at a housing of the back portion forming device 3 so as to extend in the conveying direction. Accordingly, as the links 313 open or close the driven pulleys 311c and 312c, the connecting shaft 313a is moved along the long hole 313b as shown in
Further, it may be possible to move the connecting shaft 313a along the long hole 313b by, for example, a rack-and-pinion mechanism, and to change the position of the connecting shaft 313a by controlling a drive motor that drives a pinion. Accordingly, if the sheet bundle SB is thick, it may be possible to set a conveying gap in which the sheet bundle SB is received (a distance of the nip between the driven pulleys 311c and 312c). Therefore, it may be possible to relieve pressure when portions of the upper and lower conveying belts 311 and 312 corresponding to the driven pulleys 311c and 312c run on a front end SB1 of the folded portion of the sheet bundle SB. Meanwhile, if the supply of power to the drive motor is stopped after the portions of the conveying belts run on the front end of the sheet bundle once, the driven pulleys 311c and 312c can clamp the sheet bundle SB by an elastic force of only the pressurizing spring 314 and apply a conveying force to the sheet bundle.
As shown in
The assistant clamping unit including the upper and lower assistant clamping plates 320 and 321 symmetrically approaches and be separated from the conveyance center 301, like the approaching/separating mechanism of the upper and lower conveying belts 311 and 312 of the above-mentioned conveying unit. The approaching/separating mechanism of the assistant clamping unit may be formed using the link mechanism described in the conveying unit, or the connecting mechanism or rack and sector gears. A reference position of the detection of the displaced position is set according to the detection output of an assistant clamping plate HP sensor SN3. Since a driving mechanism (not shown) and the upper and lower assistant clamping plates 320 and 321 are connected to each other by a spring such as the pressurizing spring 314 of the conveying unit, breakage caused by overload does not occur in the driving mechanism when the sheet bundle SB is clamped. Meanwhile, pressing-clamping surfaces of the upper and lower assistant clamping plates 320 and 321, which clamp the sheet bundle SB, are formed of flat surfaces parallel to the conveying direction, that is, the conveyance center 301.
The pressurization clamping unit includes upper and lower pressurization clamping plates 325 and 326. The upper and lower pressurization clamping plates 325 and 326 symmetrically approaches and be separated from the conveyance center 301, like the approaching/separating mechanism of the upper and lower conveying belts 311 and 312 of the above-mentioned conveying unit. The approaching/separating mechanism of the pressurization clamping unit may be formed using the link mechanism described in the conveying unit, or the connecting mechanism or rack and sector gears. A reference position of the detection of the upper and lower displaced positions of the upper and lower pressurization clamping plates 325 and 326 is set according to the detection output of a pressurization clamping plate HP sensor SN4. Since the operation and other structures of the upper and lower pressurization clamping plates 325 and 326 are the same as those of the above-mentioned assistant clamping plates 320 and 321, the description thereof will be omitted. Meanwhile, a drive motor is not necessary in the conveying unit. However, drive motors or other drive sources are necessary in the assistant clamping unit and the pressurization clamping unit. Accordingly, the sheet bundle SB may be moved to a clamping position and a retraction position by the driving forces generated by these drive motors or other drive sources. Further, like the upper and lower assistant clamping plates 320 and 321, pressing-clamping surfaces of the upper and lower pressurization clamping plates 325 and 326, which clamp the sheet bundle SB, are also formed of flat surfaces parallel to the conveying direction, that is, to the conveyance center 301.
The abutting unit is provided on the downstream side of the pressurization clamping unit. The abutting unit includes an abutting plate 330 and a moving mechanism (not shown) that moves the abutting plate 330 up and down. The abutting plate 330 is displaced so as to be capable of being moved forward and backward relative to the conveying passage 302, and a reference position of the detection of the displaced position of the abutting plate is set according to the detection output of an abutting plate HP sensor SN5. The top surface of the abutting plate 330 functions as a conveying guide for the sheet bundle SB at a position where the abutting plate is retracted from the conveying passage 302. For this reason, the top surface is formed of a flat surface parallel to the sheet conveying direction, that is, to the conveyance center 301. The moving mechanism may include rack-and-pinion mechanisms (not shown) that are provided, for example, on both sides of the abutting plate 330 (on the front and rear sides of the device), and a drive motor that drives a pinion. According to this structure, it may be possible to move the abutting plate 330 up and down by driving the drive motor, and to position the abutting plate at a predetermined position.
Each of the units of the back portion forming device 3 performs an operation for getting ready to receive a sheet according to the detection signal of the sheet bundle SB that is output from the folded portion passing sensor 293 or an inlet sensor (not shown) of the back portion forming device 3. In the operation for getting ready to receive a sheet, the upper and lower conveying belts 311 and 312 begin to rotate; and the upper and lower assistant clamping plates 320 and 321 are once moved to the detection position of the assistant clamping plate HP sensor SN3, that is, a home position. Subsequently the upper and lower assistant clamping plates 320 and 321 are moved toward the conveyance center 301 so as to form a predetermined conveying gap (separation distance) therebetween, and are stopped at this position. The upper and lower pressurization clamping plates 325 and 326 are also moved to the detection position of the pressurization clamping plate HP sensor SN4 (home position). Subsequently the upper and lower pressurization clamping plates 325 and 326 are moved toward the conveyance center 301 so as to form a predetermined conveying gap (separation distance) therebetween, and are stopped at this position. Meanwhile, not only the upper and lower assistant clamping plates 320 and 321 but also the upper and lower pressurization clamping plates 325 and 326 are disposed symmetrically with respect to the conveyance center 301 and are symmetrically operated. Accordingly, when the home position of one of the assistant clamping plate and the pressurization clamping plate is detected, the other thereof is also in the same state. For this reason, the HP sensors SN3 and SN4 are disposed only on one side of the plates. The abutting plate 330 is moved to the detection position of the abutting plate HP sensor SN5 (home position). Subsequently the abutting plate 330 is moved toward the conveyance center 301 by a predetermined distance, and is stopped at a position where the conveying passage 302 is blocked. This state corresponds to a state where a sheet bundle SB is not carried-in in
In this state, the sheet bundle SB, which is ejected from the lower sheet ejecting rollers 231 of the saddle-stitching device 2 and is carried to the back portion forming device 3, is carried into the back portion forming device 3 as shown in
When the sheet bundle SB is stopped in the state illustrated in
After that, when the upper and lower assistant clamping plates 320 and 321 pressurize and clamp the sheet bundle as shown in
After that, as shown in
After the upper and lower assistant clamping plates 320 and 321, the upper and lower pressurization clamping plates 325 and 326, and the abutting plate 330 are moved to waiting positions shown in
The CPU 100-1, CPU 1-1, CPU 2-1, and CPU 3-1, which are mounted on the MFP 100, the sheet post-processing device 1, the saddle-stitching device 2, and the back portion forming device 3 read program codes stored in the ROMs that are mounted on the MFP 100, the sheet post-processing device 1, the saddle-stitching device 2, and the back portion forming device 3, respectively. The CPU 100-1, CPU 1-1, CPU 2-1, and CPU 3-1 develop the program codes on RAMs; and execute programs written in the program codes by using the RAMS as work areas. Accordingly, the above-mentioned or the following various kinds of control or processing are performed. These respective devices are connected in series through the connected in series to each other in a linear shape (in an in-line form) through the communication port 100-2, the communication port 1-2, the communication port 1-3, the communication port 2-2, the communication port 2-3, and the communication port 3-2. In the case of on-line processing, control is performed under the control of the CPU 100-1 of the MFP 100 through the communication with the CPU 100-1 of the MFP 100. Meanwhile, in-line mentioned in this embodiment means that image formation, sheet processing, and saddle-stitching or booklet back surface processing are performed during the flow of the sheet bundle SB.
According to this structure, it may be possible to adjust the length of the compressed compression spring 601 in accordance with the angle of the eccentric cam 603 and to set a pressurizing force between the folding rollers 230U and 230D.
Meanwhile, the above-mentioned variable pressurizing force mechanism may be embodied in various forms by using a well-known mechanism.
An additionally folding unit 525 includes an additionally folding roller 520, a compression spring 521, and a slider 522. The slider 522 is supported between the front and rear plates of the device so as to be moved along a pair of guide rods 526 that is provided in a direction orthogonal to the sheet conveying direction. Further, the additionally folding roller 520 rolls while a predetermined pressurizing force is applied to the additionally folding roller by the compression spring 521. That is, a center folding unit includes two-folding unit that includes the first folding rollers 230 and the folding plate 215, and the additionally folding unit 525 that includes the additionally folding roller 520 for performing additionally folding, and second folding rollers 233
The additionally folding unit 525 performs additionally folding by the additionally folding roller 520 that scans the folded portion of the sheet bundle SB in a direction orthogonal to the sheet conveying direction. The additionally folding is performed by pressurizing the additionally folding roller 520 by an elastic member, herein, the compression spring 521; moving the slider 522 along the guide rods 526 on the folded portion of the sheet bundle SB while the slider is pressurized; and strengthening folding by the pressurizing force of the compression spring 521. Meanwhile, when a sheet bundle SB, is interposed between the additionally folding roller and a guide plate 528 that has a sheet receiving surface and is provided on the downstream side of the first folding rollers 230 in the sheet conveying direction, the additionally folding roller 520 may pressurize the sheet bundle SB.
Further, a driving mechanism 501, which drives the additionally folding roller 520 and performs the separation/approaching operation of lower bundle conveying rollers 206 and 205 making a pair, is provided above the additionally folding unit 525. The driving mechanism 501 includes a pressure-release motor 510, a pressure-release gear 512, an additionally folding roller driving gear 519, and an additionally folding roller driving pulley 514 (driving pulley and driven pulley). The pressure-release gear 512 receives a driving force from a drive transmission belt 515, which is stretched between a pulley fixed to a rotating shaft of the pressure-release motor 510 and a drive transmission gear 511, and is driven through a relay gear 513. Furthermore, the additionally folding roller driving gear 519 is meshed with the relay gear 513, and the pressure-release gear 512 and the additionally folding roller driving gear 519 are rotationally driven by the driving of the pressure-release motor 510.
The other end of a lever 512a, of which one end is swingably and pivotally supported by a longitudinal middle portion of a driven shaft 403 provided on the side of the lower bundle conveying roller 206 corresponding to the first folding roller 230, is rotatably and pivotally supported near the outer peripheral portion of the pressure-release gear 512 in
On the other hand, an additionally folding roller moving belt 517 is stretched between the additionally folding roller driving gear 519 and the additionally folding roller driving pulley 514, and transmits the driving force of the pressure-release motor 510 to the additionally folding roller driving pulley 514. An additionally folding roller moving belt 516 is further provided and stretched between the additionally folding roller driving pulley 514 and an additionally folding roller driven pulley, and the slider 522 for supporting the additionally folding roller 520 is mounted on the additionally folding roller moving belt 516. For this reason, the additionally folding roller moving belt 516 is stretched parallel to the guide rods 526, and the relative positions of the additionally folding roller driving pulley 514 and the additionally folding roller driven pulley are set so that the additionally folding roller moving belt is parallel to the guide rods.
In the center folding unit having the above-mentioned structure, although not particularly shown, the lower bundle conveying roller 206 approaches and is separated from the counter lower bundle conveying roller 206 and releases pressure when conveying a sheet bundle SB along the saddle-stitching tray G. Further, the additionally folding roller 520 performs additionally folding by moving in the direction substantially orthogonal to the sheet conveying direction. That is, while the state of
As described above, the lower bundle conveying roller 206 and the additionally folding roller 520 are driven by the pressure-release motor 510 and a driving force is transmitted to the drive transmission gear 511 from the drive transmission belt 515. The transmitted driving force is transmitted to the pressure-release gear 512 and the additionally folding roller driving gear 519 from the relay gear 513, and a driving force is further transmitted to the additionally folding roller driving pulley 514 through the additionally folding roller moving belt 517, so that the additionally folding roller moving belt 516 is operated. Finally, the additionally folding roller 520 is driven by the additionally folding roller moving belt 516.
According to a positional relationship between the additionally folding roller 520 and the lower bundle conveying rollers 206, the pressure of the lower bundle conveying rollers 206 is released when the additionally folding roller 520 is positioned at the home position or the maximum displacement position. The reason for this is that a sheet is jammed if the additionally folding roller 520 is positioned in a conveying range of the sheet bundle SB when folding is performed by the first folding rollers 230.
If the sheet bundle SB reaches an additionally folding position when additionally folding is performed by the additionally folding unit 525 including the additionally folding roller 520, the sheet bundle SB is stopped and the additionally folding roller 520 scans the sheet bundle at a substantially right angle so as to correspond to the folded portion of the stopped sheet bundle. This state, is shown in
When the additionally folding is completely performed by the additionally folding roller 520, the sheet bundle SB is conveyed to the downstream side and is conveyed to the back portion forming device disposed on the rear side or other processing devices by the lower sheet ejecting rollers 231. If there is no processing device on the rear side, the sheet bundle is ejected to a sheet ejection tray (not shown) as it is.
Meanwhile,
In this example, after folding is performed by the first folding rollers 230, the second folding rollers 233 further perform additionally folding at the nip parallel to the folded portion like the first folding rollers 230.
A case where swelling is generated at the back surface of the sheet bundle SB and the back surface is shaped, and a case where the folded portion of the sheet bundle SB is additionally folded by a force perpendicular to the sheet surface and the folded portion is made flat have been described above. However, in the former case, a problem occurs in the shaping of the back portion as shown in
When the back portion of the sheet bundle is formed in a flat shape in the steps shown in
On the other hand, if the amount “b” of swelling is smaller than an appropriate amount “2a” (2a>b) as shown in (1) of
However, when a flat surface is not formed at the back portion of a sheet bundle SB, the pressurizing forces of the necessary first and second folding rollers 230 and 233 and the additionally folding performed by the additionally folding roller 520 become means effective to reduce the folding height of a center-folded booklet. That is, if a folded portion of the sheet bundle SB is formed by the first and second folding rollers 230 and 233 or the additionally folding roller 520 or the swelling of a folded portion is reduced by additionally folding, it may be possible to handle a large number of sheet bundles SB while stacking the sheet bundles.
Accordingly, in this embodiment, center folding may be selected according to whether to form a flat surface at the back portion of a sheet bundle SB, the thickness of a sheet, the thickness of a sheet bundle, and the number of stitched sheets; optimum center folding may be performed on each sheet bundle to be folded; and the sheet bundle is output.
Specifically, the following processing is performed.
1) When a flat surface is not formed at the back portion of a sheet bundle SB, the pressurizing force of the folding rollers is adjusted or the additionally folding performed by the additionally folding roller is performed.
2) When a flat surface is formed at the back portion of a sheet bundle SB, additionally folding is cancelled.
3) When a flat surface is formed at the back portion of a sheet bundle SB, the pressurizing force of the folding rollers is reduced so that a folded portion of the sheet bundle is easily swelled when a flat surface is to be formed at the back portion of a sheet bundle SB. Then, the sheet bundle is conveyed to a processing device that forms a flat surface on a back surface of the sheet bundle and is provided on the rear side.
In
If the back surface forming is set (YES in Step S102), additionally folding is cancelled (Step S103), the sheet bundle is conveyed to the back portion forming device 3, back portion forming is performed on the sheet bundle in the back portion forming device 3 (Step S113), and the sheet bundle is output as a booklet.
Further, if the optimum ease of swelling of a sheet bundle SB is to be set by the number of times of additionally folding (horizontal folding), in
If the back surface forming is set in Step S102 (YES in Step S102), additionally folding is cancelled (Step S103), the regulations of the kind of a sheet (the thickness of a sheet), the number of stitched sheets, and the thickness of the sheet bundle are determined by Steps S103 to S105 that are first criteria. If the regulations are satisfied in this determination, additionally folding (horizontal folding) is cancelled (Step S106). Here, criteria (the first criteria and second criteria to be described below) are set on the basis of the ease of swelling of a saddle-stitched sheet bundle, and the numerical values of the criteria may be changed according to the characteristics (stripe direction and the like) of a sheet to be used. Further, after being determined by the first criteria (Steps S103 to S105), the regulations of the kind of a sheet, the number of stitched sheets, and the thickness of the sheet bundle are determined again by second criteria (Steps S107 to S109) and additionally folding is performed by the number of times of additionally folding that is smaller than that of normal setting (Step S110). Furthermore, if the rigidity of a sheet bundle SB is high and a sheet bundle SB is apt to be loosened by the conditions of the kind of a sheet, the number of stitched sheets, and the thickness of the sheet bundle, additionally folding is performed by the number of times of additionally folding that is normally set (Step S111).
In this embodiment, according to the first criteria, the thickness of a sheet is 110 g/m2 or less in Step S103, the number of stitched sheets is 10 or less in Step S104, and the thickness of a sheet bundle is 1.5 mm or less in Step S105. According to the second criteria, the thickness of a sheet is 130 g/m2 or less in Step S107, the number of stitched sheets is 15 or less in Step S108, and the thickness of a sheet bundle is 2.0 mm or less in Step S109.
Moreover, the number of times of additionally folding, which corresponds to normal setting, is 2 (Step S111), and the number of times of additionally folding, which is smaller than normal setting, is 1 (Step S110).
When the thickness of a sheet is larger than 110 g/m2 in Step S103 since the criteria are set as described above, it is determined whether the thickness of a sheet is equal to or smaller than 130 g/m2 in Step S107. When the thickness of a sheet is larger than 130 g/m2, additionally folding is performed two times in Step S111. When the thickness of a sheet is equal to or smaller than 130 g/m2, the process proceeds to Step S101. Even when the thickness of a sheet is 110 g/m2 or less in Step S103 and the number of stitched sheets is larger than 10 (NO in Step S104), the determination of Step S108 is performed. When the number of stitched sheets is larger 15, additionally folding is performed two times in Step S111. When the number of stitched sheets is equal to or smaller than 15, the process proceeds to Step S109. When the number of stitched sheets is 10 or less in Step S104, and the thickness of a sheet bundle is smaller than 1.5 mm, the determination of Step S109 is performed. When the thickness of a sheet bundle is larger 2.0 mm, additionally folding is performed two times in Step S111. Only when the thickness of a sheet bundle is equal to or smaller than 2.0 mm, additionally folding is performed one time in Step S110.
The sheet bundle SB, which has been subjected to predetermined processing in Steps S103 to S111, is conveyed to the back portion forming device 3, is subjected to back surface forming for forming a flat surface at a back portion of the sheet bundle SB (Step S113), and a sheet bundle (booklet) SB that has a flat surface formed at the back portion thereof is output (Step S114).
Meanwhile, criteria and two processing modes performed by determination have been shown in the flowchart shown in
Furthermore, additionally folding may be performed using the second folding rollers 233 instead of the additionally folding that is performed by the additionally folding roller 520 as shown in
In
If the back surface forming is set (YES in Step S202), the pressurizing force of the folding rollers 230 is set to B smaller than A and the sheet bundle is center-folded (Step S206), the sheet bundle is conveyed to the back portion forming device 3, back portion forming is performed on the sheet bundle in the back portion forming device 3 (Step S213), and the sheet bundle is output as a booklet (Step S214). Meanwhile, the pressurizing forces A and B may be set to, for example, high and low pressurizing forces that are shown in
When the optimum ease of swelling of a sheet bundle is set by the adjustment of a pressurizing force of the folding roller, processing of Steps S200 to S214 are performed as shown in
Meanwhile, in Steps S211 and S212, the pressurizing force of the folding rollers 230 is the high pressurizing force shown in
A sheet bundle (booklet) SB, where a flat surface is formed at a back portion or a back portion is made flat by additionally folding, is ejected as it is. Alternatively, ends may be cut by an edge cutting device 4 for the removal f irregularities of ends that are caused by back portion forming.
As shown in
Since being pressed from the drive gear 632 by a leaf spring 615, the round blade 631 is abutted on the stationary blade 620 while having always an appropriately pressing force. A timing belt 607 is an ending belt, both ends of the timing belt are fixed as shown in
Further, the home position of the slide unit 600 is detected by a cutter HP sensor 616. Meanwhile, two hoppers 702 and 705 for collecting swarf are provided below a cutter unit J.
Each of the hoppers 702 and 705 is formed in the shape of a box to receive swarf, and has a width that is equal to or larger than the maximum sheet size in a direction perpendicular to the plane of
As described above, when a flat surface is to be formed at the back portion of a sheet bundle SB by the back portion forming device 3, a pressurizing force of the folding rollers has been increased for the purpose of the reduction of the swelling of a booklet or an additionally folding roller has been disposed on the downstream side of the folding rollers and pressurized the two-folded portion so as to reduce the swelling of a booklet in the thickness direction of the booklet in a saddle-stitching and center-folding of a booklet in the conventional technology. However, if the swelling of a booklet in the thickness direction of the booklet is reduced in the forming a surface at the back portion of the booklet, it is difficult to swelling the back portion of the booklet when a flat surface is formed at the back portion of the booklet. Accordingly, in this embodiment, it may be possible to reduce the swelling of a booklet in the thickness direction of the booklet by the number of times of additionally folding of the additionally folding roller 520, the addition of additionally folding performed by the second folding rollers 233, the adjustment of the pressurizing force of the first folding rollers 230, or the like, according to a case where a flat surface is to, be formed at the back portion of a booklet or a case where a flat surface is not to be formed at the back portion of a booklet. As a result, according to this embodiment, it may be possible to obtain the following advantages.
1) Since processing is performed so as to quickly form a surface at the back portion of a back portion as compared to the conventional technology without generating wrinkles, breakage, or the like on a back surface or a stitched portion, it may be possible to reduce the swelling of a booklet in the thickness direction of the booklet.
2) Since optimum folding is performed on each of the booklets that are subjected to the forming a flat surface at the back portion of a booklet, saddle-stitching, and center-folding, it may be possible to provide a booklet of which swelling in the thickness direction is reduced under the best conditions.
3) Since swelling can be reduced by only the change of control, a mechanism does not be complicated. Accordingly, it may be possible to expect the reduction of the size of a device, the reduction of the manufacturing cost, and the reduction of power consumption and to provide an environment-friendly device.
Although the invention has been described with respect to specific embodiments for a complete and clear disclosure, the appended claims are not to be thus limited but are to be construed as embodying all modifications and alternative constructions that may occur to one skilled in the art that fairly fall within the basic teaching herein set forth.
According to the invention, it may be possible to reduce the folding height of a booklet in accordance with user's preference, regardless of whether back surface forming is performed on a booklet. That is, since additionally folding is prohibited or the number of times of additionally folding is reduced when back surface forming is performed on a booklet, it may be possible to secure the quality of back surface forming of a booklet, to reduce the power consumption, and to secure productivity. Meanwhile, since additionally folding is performed when back surface forming is not performed on a booklet, it may be possible to reduce the folding height of a booklet.
Although the invention has been described with respect to specific embodiments for a complete and clear disclosure, the appended claims are not to be thus limited but are to be construed as embodying all modifications and alternative constructions that may occur to one skilled in the art that fairly fall within the basic teaching herein set forth.
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