JP2010159095A - Sheet treatment device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an inexpensive sheet treatment device with high binding performance capable of preventing a cover from tearing or getting wrinkled regardless of an intersheet friction coefficient. <P>SOLUTION: In the sheet treatment device, a bundle of sheet is transferred while a projection transfer means 825 bends the bundle of sheet by pressing it at a position to become a crease. With a folding transportation means, the bundle of sheet is nipped in a pair of folding rollers 826 with a folding portion bent by the projection transfer means 825 as a leading end, and is transported by rotating the pair of folding rollers 826, whereby the bundle of sheet is folded while being transported. When the bundle of sheet is folded while being transported with the folding portion thereof bent by the projection transfer means 825 nipped in the pair of folding rollers, a projection folding speed control means controls such that the transportation speed of the bundle of sheet by the folding transportation means does not exceed the travel speed of the projection transfer means 825. <P>COPYRIGHT: (C)2010,JPO&amp;INPIT

Description

  The present invention relates to a sheet processing apparatus suitable for use accompanying an image forming apparatus, and more particularly to a sheet processing apparatus capable of bookbinding by folding a bundle of sheets on which images are formed.

  Conventional image forming apparatuses such as a copying machine, a printing machine, and a laser beam printer are provided with a sheet processing apparatus that sequentially takes sheets of images formed from the image forming apparatus main body and performs saddle stitch binding processing. There is something.

  In this sheet processing apparatus, as illustrated in FIG. 8, folding is performed such as folding in two by binding the vicinity of the center of the sheet bundle and conveying the bound sheet bundle to the folding unit. Eject to the part and load it.

  Next, a conventional sheet processing apparatus that performs saddle stitch binding processing will be described with reference to FIGS.

  FIG. 9 is an explanatory diagram of a schematic configuration of a sheet processing apparatus that performs a conventional saddle stitch bookbinding process.

  As shown in FIG. 9, in the sheet processing apparatus 1600, conveyance rollers 1813 and 1821 are arranged to configure a sheet conveyance path for performing saddle stitch bookbinding. A sheet stopper 1823 that can move in the vertical direction, a sheet aligning unit 1824, sheet binding devices 1818 and 1819, an ejection plate 1825, and a folding roller pair 1826 are disposed on the conveyance path. In addition, a discharge roller 1827 is disposed at the exit portion of the transport path, and a stacking tray 1832 that is a sheet bundle stacking unit is disposed on the downstream side in the transport direction.

  In the sheet processing apparatus 1600 configured as described above, a sheet discharged from an image forming apparatus main body (not shown) is carried into the sheet processing apparatus in order to perform saddle stitch binding processing.

  The conveyed sheet is transferred to the conveyance roller 1821 by the conveyance roller 1813 through the vicinity of the sheet binding devices 1818 and 1819. Then, the sheet is conveyed by the conveying roller 1821 until the leading end reaches the sheet stopper 1823 that is waiting at the first stacking position indicated by the solid line.

  Next, when the leading edge reaches the sheet stopper 1823, the conveyed sheet is aligned by aligning the side edges by the sheet aligning means 1824. Then, by repeating the operations of conveying and aligning sheets up to a predetermined number of copies, a predetermined number of sheets are aligned and bundled on the sheet stopper 1823 at the first stacking position. Loaded.

  The sheet bundle aligned on the sheet stopper 1823 is bound at the center by sheet binding devices 1818 and 1819, as shown in FIG.

  The sheet stopper 1823 on which the saddle-stitched sheet bundle is placed is lowered and moved to the second stacking position indicated by a broken line, and is set in a state where the center portion of the saddle-stitched sheet bundle faces the ejection plate 1825. .

  In this state, the projecting plate 1825 is ejected, whereby the sheet bundle bound at the center enters the nip of the pair of folding rollers 1826 and is folded into two by the pair of folding rollers 1826. Thereafter, the sheet bundle that is folded in half at the saddle stitched portion is discharged onto the stacking tray 1832 by the paper discharge roller 1827.

  Next, an operation for folding the sheet bundle into two will be described with reference to FIG. In the operation of folding the sheet bundle in half, as shown in FIG. 10A, the central portion (the bound portion) moves to a position where it faces the protruding plate 1825. Next, as illustrated in FIG. 10B, the sheet bundle is projected by the protruding plate 1825, and the sheet S <b> 1 closest to the folding roller pair 1826 comes into contact with the folding roller pair 1826. Then, the sheet is conveyed to the vicinity of the nip position of the folding roller pair 1826 by the frictional conveyance between the surface of the folding roller pair 1826 and the sheet S1.

  At this time, the sheet S2 on the protruding plate side in the sheet bundle is conveyed to the vicinity of the nip of the pair of folding rollers 1826 by so-called sheet surface friction conveyance by the sheet S1 and restraint conveyance by the binding portion X. By this operation, the sheet bundle is folded in half and discharged to the stacking tray 1832 side.

  In the operation of folding the sheet bundle in half, it is necessary that the sheet S2 on the protruding plate side in the sheet bundle is frictionally conveyed by the sheet S1 in the portion other than the binding portion X. That is, in the operation of folding the sheet bundle in half, the sheets 2 need to be conveyed so as not to be shifted from each other by the frictional force generated on the contact surfaces of the sheets S1 and S2.

  However, in the operation of folding the sheet bundle in half, the operation when conveying a portion other than the binding portion X greatly depends on the friction coefficient (μ) of the contact surface between the sheets S1 and S2.

  That is, in the operation of folding the sheet bundle in half, when the friction coefficient of the contact surface between the sheet S1 and the sheet S2 becomes small, a slip state occurs between the sheets S1 and the sheet S1 cannot be conveyed by the sheet S2.

  For example, when the sheet S1 or the sheet S2 is a sheet having a high image density such as a color entire surface image or a film material or the like, since the friction coefficient (μ) of the surface is relatively low, a slip state is easily caused.

  For this reason, when the friction coefficient (μ) of the surface of the sheet S1 or the sheet S2 is low, when the sheet S1 is drawn into the folding roller 1826 as illustrated in FIG. May slip.

  As a result, only the cover sheet, which is the sheet S1, is conveyed to the folding roller 1825 in advance, so that there is a possibility that sheet tearing or wrinkles may occur in the binding portion. It should be noted that the occurrence of tears and wrinkles is likely to occur immediately after the start of folding.

  Therefore, as illustrated in FIG. 12, a method of preventing the front sheet only from being conveyed in advance by changing the amount of movement of the veneer and protruding the sheet bundle with the veneer 1825 until the folding roller pair 1826 is exceeded. It is done.

  In addition, in a conventional sheet processing apparatus that performs saddle stitch bookbinding, the rotational speed of the pair of folding rollers and the moving speed of the veneer are slowed only when the friction coefficient between the sheets is low. As a result, in a sheet processing apparatus that performs saddle stitch binding processing, a method has been proposed in which only the front cover is prevented from being conveyed in advance while maintaining productivity when the friction coefficient is high (for example, Patent Document 1). reference).

  Further, in a sheet processing apparatus that performs a saddle stitch binding process that has been proposed conventionally, a load varies depending on the number and type of sheets, and a large torque is temporarily required when the sheet collides. For this reason, the conventionally proposed sheet processing apparatus that performs saddle stitch binding processing has a configuration in which the veneer is driven by a DC motor whose speed changes depending on the load.

  With the sheet processing apparatus configured as described above and performing the saddle stitch bookbinding process conventionally proposed, the effects illustrated in FIG. 13 can be obtained. FIG. 13 is a graph showing the relationship between the conveyance speed W of the folding roller pair 1826 and the sheet bundle ejection speed X by the thrust plate 1825 in a small number of sheet bundles, with the horizontal axis representing time and the vertical axis representing speed.

  As can be seen from FIG. 13, in the conventional sheet processing apparatus configured as described above for performing saddle stitch bookbinding, the load on the motor that drives the veneer is cut in the operation of folding a small number of sheet bundles in half. Becomes lower. For this reason, the conveyance speed of the folding roller pair 1826 at the time point Y when the sheet bundle comes into contact with the folding roller pair 1826 is slower than the protruding speed X as indicated by the arrow V, and the cover is torn and wrinkles occur. You can see that there is no.

JP 2005-089100 A

  However, in the former method illustrated in FIG. 12, when the number of sheets is large, the load applied to the motor when the sheets are ejected increases, and the speed of the thrust plate is reduced as shown in FIG. FIG. 14 is a graph showing the relationship between the conveying speed W of the folding roller pair 1826 and the sheet bundle ejecting speed X by the thrust plate in a large number of sheet bundles, with the horizontal axis representing time and the vertical axis representing speed.

  As can be seen from FIG. 14, at the point Y when the sheet bundle comes into contact with the folding roller pair 1826, as indicated by the arrow V, the conveying speed by the folding roller pair 1826 is faster than the ejection speed.

  Under such circumstances, when the friction coefficient between the sheets is low, only the cover sheet is conveyed in advance and slips between the sheets adjacent to the cover sheet. May occur.

  Further, in the latter method described with reference to FIG. 13, the thrusting plate is driven by a DC motor whose speed changes depending on the load, and the thrusting speed of the thrusting plate is lowered when the friction coefficient is low, so that productivity is reduced. There's a problem.

  Productivity is evaluated by the number of processed sheets within a predetermined time. Since the process of folding the sheet bundle occurs for each sheet bundle, the processing time required here is divided by the number of sheet bundles and reflected in productivity. Therefore, the smaller the number of sheet bundles, the more the sheet bundle is folded. The effect of the time required for processing on productivity increases. That is, in order to increase productivity, it is necessary to shorten the folding time for a small number of sheets.

  An object of the present invention is to provide an inexpensive sheet processing apparatus having an excellent bookbinding quality capable of suppressing the occurrence of cover breakage or wrinkles regardless of the friction coefficient between sheets.

  In order to achieve the above object, a sheet processing apparatus according to claim 1, wherein a projecting member that is moved to project the sheet bundle, a moving unit that moves the projecting member, and the sheet bundle by moving the projecting member. A folding and conveying means for folding the sheet bundle by sandwiching and conveying the sheet bundle with the bent folding portion at the top, and when folding the sheet bundle, the sheet bundle by the folding and conveying means Speed control means for controlling the conveyance speed to be equal to or lower than the movement speed of the protruding member by the movement means.

  According to the present invention, it is possible to provide an inexpensive sheet processing apparatus having an excellent bookbinding quality capable of suppressing the occurrence of cover tear or wrinkles regardless of the coefficient of friction between sheets.

1 is a schematic configuration explanatory view showing the internal structure of a copying apparatus according to an embodiment of the present invention in section. It is a schematic structure explanatory drawing which shows the internal structure of a finisher in a cross section. 1 is a block diagram of a control system that comprehensively controls an image forming apparatus and a sheet processing apparatus. It is a flowchart which shows the procedure of the discrimination process of the operation mode which the sheet processing apparatus control part of a finisher performs. 6 is a flowchart illustrating a bookbinding process performed by a sheet processing apparatus control unit when an operation mode is a bookbinding mode. 6 is a flowchart illustrating a procedure of folding processing executed by the sheet processing apparatus control unit in bookbinding processing. FIG. 5 is an explanatory diagram showing a relationship between a conveying speed W of a pair of folding rollers in a large number of sheet bundles and an ejection speed X of a sheet bundle by a thrust plate, with the horizontal axis representing time and the vertical axis representing speed. In the sheet processing apparatus, it is an explanatory view exemplifying a book that has been bound in the vicinity of a substantially central portion of a sheet bundle and is subjected to a folding process for a folded sheet bundle. It is schematic structure explanatory drawing of the sheet processing apparatus which performs the conventional saddle stitch bookbinding process. (A) thru | or (d) is a schematic operation | movement explanatory drawing which illustrates each operation | movement which folds a sheet bundle in the sheet processing apparatus which performs the conventional saddle stitch bookbinding process. FIG. 10 is a schematic operation explanatory view illustrating an enlarged state of slipping between an outer sheet and a sheet adjacent to the inner side when the outer sheet is drawn into the folding roller. A method is conceivable in which only the front cover is prevented from being conveyed in advance by ejecting the sheet bundle with the thrust plate until the pair of folding rollers is exceeded. FIG. 5 is an explanatory diagram showing a relationship between a conveying speed W of a pair of folding rollers in a small number of sheet bundles and an ejection speed X of a sheet bundle by a pushing plate, with the horizontal axis representing time and the vertical axis representing speed. FIG. 5 is an explanatory diagram showing a relationship between a conveying speed W of a pair of folding rollers in a large number of sheet bundles and an ejection speed X of a sheet bundle by a thrust plate, with the horizontal axis representing time and the vertical axis representing speed.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 is a schematic configuration explanatory view showing the internal structure of a copying apparatus 1000 according to an embodiment of the present invention in cross section.

  1, the copying apparatus 1000 according to the present embodiment includes a document feeding unit 100, an image reader unit 200, a printer unit 300, a folding processing unit 400, a finisher 500, and an inserter 900.

  A stack of documents is set on the tray 1001 of the document feeding unit 100 in an upright state as viewed from the user and in a face-up state (the surface on which an image is formed is facing upward). And Further, the binding position of the document is assumed to be located at the left end portion of the document.

  Documents set on the tray 1001 are conveyed by the document feeder 100 one by one from the first page in the left direction (in the direction of arrow K in the figure), with the binding position as the leading edge. Then, the document is conveyed from the left direction to the right direction on the platen glass 102 through a curved path, and then discharged onto the discharge tray 112. At this time, the scanner unit 104 is held in a predetermined position, and a document reading process is performed as the document passes through the scanner unit 104 from left to right. Such a method of reading a document is called “original document scanning”.

  In this original reading process, the original is irradiated by the lamp 103 of the scanner unit 104 when passing through the platen glass 102, and the reflected light from the original passes through the mirrors 105, 106, 107 and the lens 108 and the image sensor 109. Led to.

  In this copying apparatus 1000, the document transported by the document feeding unit 100 is temporarily stopped on the platen glass 102, and the scanner unit 104 is moved from left to right in this state to perform document reading processing. Is also possible. Such an original reading method is called “original fixed reading”.

  When the original is read without using the original feeding unit 100 in the copying apparatus 1000, the user lifts the original feeding unit 100, sets the original on the platen glass 102, and then switches the original fixed reading. To start operation.

  In the original fixed reading process, the image data of the original read by the image sensor 109 is subjected to predetermined image processing and sent to the exposure control unit 110. The exposure control unit 110 outputs a laser beam for forming an electrostatic latent image corresponding to the image signal. This laser beam is irradiated onto the photosensitive drum 111 while being scanned by the polygon mirror 110a. An electrostatic latent image is formed on the photosensitive drum 111 by the scanned laser light. The electrostatic latent image formed on the photosensitive drum 111 is developed by the developing device 113 and visualized as a toner image.

  On the other hand, the recording paper is conveyed to the transfer unit 116 from any of the cassettes 114 and 115, the manual paper feeding unit 125, and the double-sided conveyance path 124. Then, the visualized toner image is transferred to the recording paper in the transfer unit 116. The recording sheet after the transfer is subjected to a fixing process by the fixing unit 117.

  The recording paper on which the image has been fixed by the fixing unit 117 in this way is once guided to the path 122 by the flapper 121, and after the trailing edge of the recording paper has passed through the flapper 121, the recording paper is switched back to the discharge roller 118 by the flapper 121. Be transported. Then, the recording paper on which the image is formed by the discharge roller 118 is discharged from the printer unit 300. As a result, the surface on which the toner image is fixed is discharged from the printer unit 300 in a downward state (face-down). The discharge operation of the recording paper on which such an image is formed is called reverse discharge.

  As described above, when reverse paper discharge is performed in which the recording paper is discharged and stacked outside the apparatus as described above, the page order can be aligned by performing image forming processing in order from the first page. This reverse paper discharge is performed, for example, in order to align the page order when image forming processing is performed using the document feeder 100 or when image forming processing is performed on image data from a computer.

  When image forming processing is performed on a hard sheet such as an OHP sheet conveyed from the manual sheet feeding unit 125, the printer unit is driven by the discharge roller 118 with the surface on which the toner image is formed facing upward (face up). Drain from 300. Therefore, when the image forming process is performed on the hard sheet, the hard sheet is not guided to the path 122.

  When image forming processing is performed on both sides of the sheet, the sheet is guided straight from the fixing unit 117 toward the discharge roller 118, and the sheet is switched back immediately after the trailing edge of the sheet passes through the flapper 121. Leads to the duplex transport path. Then, an image is formed on both sides of the sheet by passing the printer unit 300 again from the duplex conveyance path.

  The sheet on which the image is formed, which is discharged from the printer unit 300 by the discharge roller 118 as described above, is sent to the folding processing unit 400. In the folding processing unit 400, folding processing is performed so that the sheet is folded in a Z shape. For example, when an A3 size or B4 size sheet is specified and the folding process is designated by the operation unit, the folding process is performed on the sheet discharged from the printer unit 300. On the other hand, in other cases, the sheet discharged from the printer unit 300 is sent to the finisher 500 without being folded.

  Next, the configuration of the finisher 500 will be described with reference to FIG. FIG. 2 is a schematic configuration explanatory view showing the internal structure of the finisher 500 in cross section.

  The finisher 500 performs processing to take in sheets from the printer unit 300 conveyed via the folding processing unit 400, align the plurality of taken-in sheets, and bundle them as one sheet bundle. Further, the finisher 500 is configured to perform sheet post-processing such as stapling processing (binding processing) for stapling the rear end side of the sheet bundle, sorting processing, non-sorting processing, and bookbinding processing.

  Further, the finisher 500 includes a punch unit 550 on the internal sheet conveyance path. The finisher 500 is configured so that a punching process (synonymous with punching process) can be performed on a sheet conveyed from the inserter 900 or the printer unit 300 by the punch unit 550.

  As shown in FIG. 2, the finisher 500 includes an entrance roller pair 502 for taking a sheet from the printer unit 300 conveyed via the folding processing unit 400 into the apparatus. A switching flapper 551 for guiding the sheet to the finisher path 552 or the first bookbinding path 553 is provided downstream of the inlet roller pair 502.

  The sheet guided to the finisher path 552 is conveyed toward the buffer roller 505 via the conveyance roller pair 503. Note that the conveyance roller pair 503 and the buffer roller 505 are configured to be capable of forward and reverse rotation.

  An entrance sensor 531 is provided between the entrance roller pair 502 and the transport roller pair 503. Note that the second bookbinding path 554 branches from the finisher path 552 in the vicinity of the upstream of the inlet sensor 531. Hereinafter, this branch point is referred to as branch A.

  This branch A forms a branch to the conveyance path for conveying the sheet from the inlet roller pair 502 side to the conveyance roller pair 503 side. Further, this branch A includes a one-way mechanism that rotates the conveying roller pair 503 in the reverse direction and conveys the sheet only to the second bookbinding path 554 side when conveying the sheet from the conveying roller pair 503 side to the entrance sensor 531 side. .

  The sheet conveyed from the first bookbinding path 553 or the second bookbinding path 554 passes through the bookbinding entrance sensor 817 and is stored in the storage guide 820 via the conveyance roller pair 813. Note that the sheet conveyed by the conveyance roller 813 is conveyed until the leading end of the sheet comes into contact with the movable sheet positioning member 823. A bookbinding entrance sensor 817 is disposed on the upstream side of the transport roller 813. Further, two pairs of staplers 818 are provided on the downstream side of the conveying roller 813, that is, in the middle of the storage guide 820, and an anvil 819 is provided at a position facing the stapler 818. The stapler 818 is configured to bind the center of the sheet bundle in cooperation with the anvil 819.

  On the downstream side of the stapler 818, a pair of folding rollers 826 for constituting a folding conveying unit is disposed. The folding roller pair 826 as the folding conveying means can sandwich the sheet bundle between a pair of folding rollers arranged in parallel from the folded portion (folded portion) of the sheet bundle and rotate the roller. Configure.

  Further, a protruding member 825 is disposed at a position facing the pair of folding rollers 826. The protruding member 825 is configured to be able to move a rectangular flat plate-shaped tip portion toward the rolling contact position of the pair of rollers in the folding roller pair 826. Note that the protruding member 825 may be configured to extend and contract and move the tip. The protruding member 825 configured in this manner is configured to abut the tip side of the sheet bundle stored in the storage guide 820 with a fold (fold line) by the protruding operation. The sheet bundle is conveyed while being folded by the pair of folding rollers 826, the folding portion of which is pushed between the folding roller pair 826 by the protruding member 825.

  The protrusion member 825 used in this way is driven by a thrust plate drive motor 851 as a moving means. The veneer moving speed when the extruding member 825 is driven is detected by a veneer moving speed detection sensor 852 as a thrust speed detecting means. The veneer moving speed detection sensor 852 is configured to read a linear encoder attached to the veneer with an optical sensor. The linear encoder is provided with a plurality of predetermined slit holes. The optical sensor of the linear encoder is turned on in response to light transmitted through a place where there is a slit hole, and is turned off when light is blocked at a place where there is no slit hole. Therefore, in this linear encoder, the moving speed of the veneer is obtained from the ON / OFF cycle detected by the optical sensor.

  A folding roller pair 826 for folding the sheet bundle is driven by a folding roller driving motor 853. The rotational speed of the driven folding roller pair 826 is detected by a folding roller rotational speed detection sensor 854 that is a conveyance speed detection means. The folding roller rotation speed detection sensor 854 is configured to read an encoder attached to a drive shaft that drives the folding roller with an optical sensor. The optical sensor receives light transmitted through a place where there is a slit hole and is turned on, and light is blocked and turned off where there is no slit hole. Therefore, the encoder attached to the drive shaft that drives the folding roller obtains the rotational speed of the drive shaft from the ON / OFF cycle detected by the optical sensor, and detects the conveying speed by the folding roller based on this.

  After being conveyed while being folded by the pair of folding rollers 826, the conveyance by the pair of folding rollers 826 is temporarily stopped, the press unit 1200 is moved in a direction orthogonal to the conveying direction, and the crease at the leading end of the sheet bundle is crushed. The sheet on which the crease is formed in this manner is discharged onto a discharge tray 832 via a discharge roller 827.

  Next, a control system that comprehensively controls the image forming apparatus and the sheet processing apparatus will be described with reference to FIG.

  FIG. 3 is a block diagram of a control system that comprehensively controls the image forming apparatus and the sheet processing apparatus.

  A control system that comprehensively controls the image forming apparatus and the sheet processing apparatus includes a CPU circuit unit 305. The CPU circuit unit 305 includes a CPU 309, a ROM 306 and a RAM 307 as storage means. The ROM 306 stores a control program that comprehensively controls each block. That is, the CPU circuit unit 305 comprehensively controls the document feeder control unit 301, the image reader control unit 302, the image signal control unit 303, the printer control unit 304, the operation unit 308, and the sheet processing device control unit 501.

  The RAM 307 is used when temporarily holding control data or holding data as a work area for arithmetic processing associated with control.

  A sheet processing apparatus control unit 501 controlled by the CPU circuit unit 305 is mounted on the sheet processing apparatus 500. The sheet processing apparatus control unit 501 is configured to be able to drive and control the entire sheet processing apparatus 1 by communicating information data with the CPU circuit unit 305 via a communication IC (IPC) (not shown). ing. Further, the sheet processing apparatus control unit 501 includes a CPU 401, a ROM 402, and a RAM 403.

  The sheet processing apparatus control unit 501 controls various actuators and various sensors based on a control program stored in the ROM 402.

  For example, the sheet processing apparatus control unit 501 controls a veneer moving speed detection sensor 852, a folding roller rotation speed detection sensor 854, a veneer driving motor 851, a folding roller driving motor 853, a folding roller speed control unit 855, and the like. The RAM 403 temporarily stores control data and is used as a work area for arithmetic processing associated with control.

  The folding roller speed control unit 855 compares the detection result of the veneer moving speed detection sensor 852 with the detection result of the folding roller rotation speed detection sensor 854. Then, the folding roller speed control unit 855 controls the drive output to the folding roller drive motor 853 so that the rotational speed of the folding roller is slower than the moving speed of the thrust plate 825 based on the comparison result. Instead of providing the folding roller speed control unit 855, the CPU 411 may execute the function.

  Next, processing related to drive control performed by the sheet processing apparatus control unit 501 of the finisher 500 will be described with reference to FIG.

  FIG. 4 is a flowchart illustrating a procedure of operation mode determination processing performed by the sheet processing apparatus control unit 501 of the finisher 500.

  The operation mode determination process is executed by the CPU 401 in the sheet processing apparatus control unit 501 based on an instruction from the CPU circuit unit 305.

  First, the process waits until a finisher start signal for instructing the finisher 500 to start operation is input from the CPU circuit unit 305 to the sheet processing apparatus control unit 501 (NO in step S2301).

  When the user presses a start key for instructing the start of copying in the operation unit 308, a finisher start signal is input from the CPU circuit unit 305 to the sheet processing apparatus control unit 501. When the CPU 401 determines that a finisher start signal has been input (YES in step S2301), the CPU 401 starts driving an inlet motor (not shown) that drives the inlet roller pair 502 (step S2302).

  Next, the CPU 401 of the sheet processing apparatus control unit 501 determines whether there is a paper feed request to the inserter 900 based on the data from the CPU circuit unit 305 (step S2303). A paper feed request to the inserter 900 is sent to the sheet processing apparatus control unit 501 when the user selects a mode for inserting insert paper.

  If the CPU 401 of the sheet processing apparatus control unit 501 determines that there is a paper feed request for the inserter 900 (YES in step S2303), it performs a pre-inserter paper feed process. (Step S2304) (Since this step S2304 is not directly related to the gist of the invention, a detailed description thereof is omitted.) Then, the CPU 401 of the sheet processing apparatus control unit 501 has completed the pre-inserter paper feed process. In this case, a paper feed signal is output to the CPU circuit unit 305 (step S2305).

  If the CPU 401 of the sheet processing apparatus control unit 501 determines that there is no paper feed request to the inserter 900 in step S2303 (NO in step S2303), the CPU 401 outputs a paper feed signal to the CPU 309 of the CPU circuit unit 305. (Step S2305).

  Upon receiving this paper feed signal, the CPU 309 of the CPU circuit unit 305 separately executes image forming processing by the printer unit 300 and carries out the sheet on which the image has been formed to the finisher 500 side.

  Next, based on the post-processing mode data received from the CPU circuit unit 305, the CPU 401 of the sheet processing apparatus control unit 501 determines whether or not the operation mode set by the operation unit 308 is the bookbinding mode (step). S2306).

  In step S2306, when the CPU 401 determines that the set operation mode is the bookbinding mode (YES in step S2360), the CPU 401 performs a bookbinding process (step S2307). A detailed description of the bookbinding process in step S2307 will be described later with reference to FIG. When the bookbinding process is completed in step S2307, the CPU 401 ends the operation mode determination process for the finisher.

In step S2306, when the CPU 401 determines that the set operation mode is not the bookbinding mode (NO in step S2306), the CPU 401 determines whether the punch mode is set by the user. (Step S2313)
If the CPU 401 determines that the punch mode is set (YES in step S2313), the CPU 401 sets the punch mode flag to ON (step S2314), and proceeds to step S2308. On the other hand, if the CPU 401 determines that the punch mode is not set (NO in step S2313), the CPU 401 proceeds directly to step S2308.

  In step S2308, the CPU 401 determines whether the set operation mode is a non-sort mode, a sort mode, or a staple sort mode.

  In step S2308, when the CPU 401 determines that the set operation mode is the non-sort mode, the CPU 401 executes non-sort processing (step S2309). Since step S2309 is not directly related to the gist of the invention, detailed description thereof is omitted.

  In step S2308, when the CPU 401 determines that the set operation mode is the sort mode, the CPU 401 executes sort processing (step S2310). Since step S2310 is not directly related to the gist of the invention, detailed description thereof is omitted.

  Further, in step S2308, when the CPU 401 determines that the set operation mode is the staple sort mode, the CPU 401 executes a staple sort process (step S2311). Since step S2311 is not directly related to the gist of the invention, detailed description thereof is omitted.

  Next, when any of the sorting processes described above is completed, the CPU 401 stops driving the inlet motor M1. At the same time, if the punch mode flag is set to ON in step S2314, the CPU 401 sets the punch mode flag to OFF and ends the operation mode determination processing for the finisher.

  In the above-described operation mode determination process for the finisher, any one of steps S2307, S2309, S2310, and S2311 is performed. In any of these processes, when it is determined in step S2303 that there is a paper feed request to the inserter 900, the CPU 401 first performs the pre-inserter paper feed process in step S2304.

  Next, the bookbinding process in step S2307 in FIG. 4 will be described using the flowchart in FIG.

  FIG. 5 is a flowchart illustrating a bookbinding process performed by the CPU 401 of the sheet processing apparatus control unit 501 when the operation mode is the bookbinding mode.

  This bookbinding process is a process performed when the CPU 401 determines that the operation mode is the bookbinding mode in step S2306 in FIG.

  In this bookbinding process, first, the CPU 401 of the sheet processing apparatus control unit 501 determines whether or not the size of the sheet conveyed from the printer unit 300 to the finisher 500 is a size suitable for bookbinding (step S2801). ). The size suitable for bookbinding is a size in which the longitudinal direction of the sheet is the conveyance direction, such as A4R size, B4 size, and A3 size. If the CPU 401 determines in step S2801 that the sheet size is not suitable for bookbinding, the CPU 401 ends this processing and returns to step S2301 in FIG.

  On the other hand, in step S2801, if the CPU 401 determines that the sheet size is suitable for bookbinding, the CPU 401 performs bookbinding initial operation processing (step S2802).

  In the bookbinding initial operation process, the CPU 401 of the sheet processing apparatus control unit 501 drives a conveyance motor (not shown) to rotate the bookbinding roller pair 813 so that the sheet can be conveyed. At the same time, the CPU 401 drives a switching solenoid (not shown) to switch the flapper 551 to the first bookbinding path 553 so that the sheet from the printer unit 300 is guided to the storage guide 820.

  In the bookbinding initial operation process, the CPU 401 performs control to position the width adjusting member (not shown) so as to have a predetermined margin with respect to the sheet width. At the same time, the CPU 401 rotates a positioning motor (not shown) by a predetermined number of steps so that the distance from the sheet positioning member 823 to the staple position of the stapler 818 is ½ of the length in the sheet conveying direction.

  Next, the CPU 401 of the sheet processing apparatus control unit 501 waits for the sheet from the printer unit 300 to be conveyed into the storage guide 820 by a signal from the bookbinding entrance sensor 817 (step S2803).

  On the other hand, in step S2803, when the CPU 401 determines that the sheet from the printer unit 300 has been conveyed into the storage guide 820, the CPU 401 operates a width adjusting member (not shown) after a predetermined time has elapsed. Further, the CPU 401 performs an alignment operation in the sheet width direction with respect to the sheet stored in the storage guide 820 (step S2804).

  Next, the CPU 401 determines whether or not the sheet processed in step S2804 is the final sheet of the sheet to be bound as one bundle (step S2805). If the sheet is not the final sheet, It returns to step S2803.

  On the other hand, if the CPU 401 determines in step S2805 that the sheet is the last sheet, the CPU 401 determines whether or not the user has designated the sheet feeding from the inserter 900 (step S2806). If the CPU 401 determines that paper feed from the inserter 900 is designated, the CPU 401 performs inserter paper feed processing (step S2807).

  On the other hand, if the CPU 401 determines in step S2806 that the sheet feeding from the inserter 900 is not designated, the CPU 401 executes the stapling process using the stapler 818 on the sheet bundle aligned in the storage guide 820. (Step S <b> 2808) After executing the process of step S <b> 2808, the CPU 401 executes a bundle conveying process for the sheet bundle. (Step S2809) The CPU 401 drives a positioning motor (not shown) to transfer the sheet bundle by the distance between the staple position of the stapler 818 and the nip position of the folding roller pair 826 in the bundle conveyance process of Step S2809. The positioning member 823 is lowered. At the same time, the CPU 401 drives a transport motor (not shown) again to rotate the transport roller pair 813 in the bundle transport process.

  Next, the CPU 401 of the sheet processing apparatus control unit 501 executes a folding control process. (Step S2810) Detailed description regarding the folding control processing in step S2810 will be described later with reference to FIG.

  Next, when the CPU 401 of the sheet processing apparatus control unit 501 executes the folding control process in step S2810, the CPU 401 moves the press unit 1200 in the direction orthogonal to the conveying direction, and executes a pressing process (step S2811) that crushes the folds of the sheet bundle. To do.

  Next, the CPU 401 of the sheet processing apparatus control unit 501 executes a paper discharge process (step S2812) for discharging the sheet bundle to the stacking tray. Further, the CPU 401 executes a press unit retracting process for moving the press unit 1200 to the standby position for pressing the next bundle (step S2813).

  Next, the CPU 401 of the sheet processing apparatus control unit 501 stops the driving of the folding roller drive motor 853 (step S2814), and determines whether or not the sheet bundle is the last sheet bundle to be bound ( Step S2815).

  Next, when the CPU 401 of the sheet processing apparatus control unit 501 determines that it is the last sheet bundle to be bound (YES in step S2815), the bookbinding mode end process is performed (step S2816).

  In the bookbinding mode end process, the CPU 401 of the sheet processing apparatus control unit 501 performs control so that the above-described width adjusting member and the sheet positioning member 823 are respectively moved to predetermined standby positions. Further, the CPU 401 of the sheet processing apparatus control unit 501 performs control to switch the switching flapper 551 to the finisher path 552 side, and ends the bookbinding mode. After executing the bookbinding mode end process (step S2816), the process returns to step S2301 of the flowchart shown in FIG.

  On the other hand, if the CPU 401 determines in step S2815 that it is not the last sheet bundle to be bound (NO in step S2815), it returns to step S2803.

  Next, the folding process executed in step S2810 in the bookbinding process of FIG. 5 will be described using the flowchart of FIG. 6 and the explanatory diagram of FIG.

  FIG. 6 is a flowchart illustrating a procedure of folding processing executed by the sheet processing apparatus control unit in bookbinding processing.

  FIG. 7 is an explanatory diagram showing the relationship between the conveyance speed W of the folding roller pair 826 and the sheet bundle ejection speed X of the sheet bundle 825 in a large number of sheet bundles, with the horizontal axis representing time and the vertical axis representing speed.

  In the folding control process, first, the CPU 401 starts driving the folding roller drive motor 853 (step S101). In FIG. 7, it starts from the state where the rotational speed of the pair of folding rollers is already constant.

  Next, the CPU 401 starts driving the veneer drive motor 851 (step S102) and waits for a predetermined time until the veneer starts moving (step S103). When a predetermined time has elapsed, the CPU 401 performs synchronous control of the veneer moving speed and the folding roller rotation speed. In FIG. 7, synchronous control is started from time U. Synchronous control is executed by the folding roller speed control unit 855.

  First, the CPU 401 compares the detection results of the veneer moving speed detection sensor 852 and the folding roller rotation speed detection sensor 854, and determines whether or not the veneer speed is higher (step S104).

  If the CPU 401 of the sheet processing apparatus control unit 501 determines in step S104 that the veneer speed is slower (NO in step S104), the CPU 401 decreases the speed of the folding roller drive motor and reduces the folding roller rotation speed. (Step S105).

  The speed of the folding roller drive motor 853 is controlled by controlling the current or voltage supplied to the folding motor. When the drive motor is a stepping motor, it is performed by controlling the frequency of the drive pulse.

  On the other hand, when the CPU 401 determines that the veneer speed is faster (YES in step S104), the CPU 401 determines whether or not the difference between the folding roller rotation speed and the veneer speed is smaller than a predetermined value A (step S106). .

  Next, when the CPU 401 determines that the difference between the veneer speed and the folding roller rotation speed is A or more (NO in step S106), the folding roller rotation speed is slower than necessary, and the folding control process takes time. The speed of the folding roller drive motor 853 is increased. By performing the above-described control, the CPU 401 suppresses the occurrence of cover, blurring, and wrinkles at the time Y when the sheet bundle contacts the folding roller pair 826 in FIG.

  On the other hand, when the CPU 401 determines that the difference between the veneer speed and the rotation speed of the folding roller is smaller than A (YES in step S106) or when the process in either step S105 or step S107 is completed, the process proceeds to step S108. . In step S108, the CPU 401 determines whether or not the veneer 825 has moved a predetermined distance since the movement started. The CPU 401 determines whether or not the thrust plate 825 has moved by a predetermined distance based on the number of pulses of the encoder attached to the drive shaft of the thrust plate 825 read by the thrust plate moving speed detection sensor 852. The predetermined distance in step S108 is a distance from the start of movement of the pushing plate 825 to the end of insertion of the sheet bundle into the folding roller pair 826 by the pushing plate 825. In FIG. 7, the sheet bundle is completely inserted into the folding roller pair 826 at the time Z.

  Next, when the CPU 401 determines that the veneer 825 has moved a predetermined distance (YES in step S108), the CPU 401 stops the veneer drive motor 851 (step S109) and ends the folding control process. When the CPU 401 determines that the pushing plate 825 has moved by a predetermined distance, it is after the movement to the distance at which the insertion of the sheet bundle into the folding roller pair 826 is completed.

  On the other hand, if the CPU 401 determines that the movement of the veneer 825 has not been completed (NO in step S108), the process returns to step S104. Then, the CPU 401 continues the synchronous control of the moving speed of the thrust plate 825 and the rotational speed of the folding roller pair 826.

  As described above, in the folding process executed by the CPU 401 of the sheet processing apparatus control unit, the abutting plate 825 comes into contact with and pushes against the fold line (scheduled fold line position) of the sheet bundle. Further, the abutting plate 825 pushes a portion that forms a crease bent at the crease line, and inserts the bent portion of the sheet bundle between the rollers of the pair of folding rollers 826. As a result, the sheet bundle is sandwiched between the folding roller pair 826 with the bent folded portion as the head, and is further conveyed by the rotating operation of the folding roller pair 826.

  In short, the CPU 401 determines that the conveying speed of the folding roller pair 826 is higher than the moving speed of the veneer plate 825 until the bent portion of the sheet bundle is inserted between the rollers of the folding roller pair 826 and the conveyance is completed. Control to slow down. That is, the CPU 401 performs control so that the conveying speed of the sheet bundle by the folding roller pair 826 is equal to or lower than the moving speed of the abutting plate 825.

  By this control, the sheet (cover) on the outermost side of the sheet bundle is pushed by the pushing plate 825 and tends to advance faster than the conveying speed of the folding roller pair 826. For this reason, the outermost sheet (cover) of the sheet bundle is subjected to resistance in the direction opposite to the conveying direction from the pair of folding rollers 826 that are in rolling contact with the sheet.

  Therefore, the sheet (cover) on the outermost side of the sheet bundle is pressed against the abutting plate 825 together with the sheets on the inner side. Thus, the outermost sheet (cover) of the sheet bundle is pressed against the second sheet on the inner side without depending on the coefficient of friction between the sheets, and no gap is formed. At the same time, the bent portion of the sheet bundle is bent in an integrated state with no gap, and a fold is appropriately formed, so that the tearing of the cover and generation of wrinkles can be suppressed.

  In this folding process, the period during which the conveyance speed of the folding roller pair 826 is controlled is determined when the sheet bundle is inserted after the bent portion of the sheet bundle abuts against the folding roller pair 826 and then passed through the holding portion of the folding roller pair 826. It may be until the operation of is completed.

  Further, in the embodiment of the present invention, the folding conveying means is configured by the folding roller pair 826, but it may be configured such that a bent portion of the sheet bundle is sandwiched between the pair of belt winding mechanisms to make a crease. .

  In the sheet processing apparatus of the present invention, when the sheet bundle is folded, a speed control unit that controls the conveyance speed of the sheet bundle by the folding conveyance unit may be configured to control as follows.

  The speed control unit controls to decrease the conveyance speed of the sheet bundle by the folding conveyance unit when the speed detected by the abutting speed detection unit is not larger than the conveyance speed detected by the conveyance speed detection unit.

  The speed control unit controls to increase the conveyance speed of the sheet bundle by the folding conveyance unit when the difference between the conveyance speed detected by the conveyance speed detection unit and the speed detected by the abutting speed detection unit is equal to or greater than a predetermined value. .

  The speed control means controls to terminate the speed control of the folding conveying means according to the detection result of the protrusion speed detecting means when the protrusion member moves by a predetermined amount.

  This speed control means controls to start the speed control of the folding conveyance means according to the detection result of the thrust speed detection means after a predetermined time has elapsed since the movement means started.

  Further, in the sheet processing apparatus according to the present invention, the moving means may be constituted by a DC motor whose speed changes according to the load.

500 Finisher 825 Veneer plate 826 Folding roller pair 851 Veneer plate drive motor 852 Veneer plate moving speed detection sensor 853 Folding roller drive motor 854 Folding roller rotation speed detection sensor 855 Folding roller speed control unit 1000 Image forming apparatus

Claims (7)

A protruding member that is moved to poke the sheet bundle;
Moving means for moving the protruding member;
A folding and conveying means that folds the sheet bundle by sandwiching and conveying the sheet bundle with the bent portion of the sheet bundle bent by the movement of the protruding member; and
Speed control means for controlling the sheet bundle conveying speed by the folding conveying means to be equal to or lower than the moving speed of the protruding member by the moving means when folding the sheet bundle;
A sheet processing apparatus comprising: A protrusion speed detecting means for detecting a moving speed of the protrusion member when the folded portion of the sheet bundle is inserted into the fold conveying means and conveyed;
A conveyance speed detection means for detecting a conveyance speed of the sheet bundle by the folding conveyance means;
The speed control means controls the transport speed of the sheet bundle by the folding transport means according to the detection results of the thrust speed detection means and the transport speed detection means. The sheet processing apparatus according to the description.   The speed control means reduces the sheet bundle conveying speed by the folding conveying means when the speed detected by the abutting speed detecting means is not larger than the conveying speed detected by the conveying speed detecting means. The sheet processing apparatus according to claim 2.   The speed control means increases the conveyance speed of the sheet bundle by the folding conveyance means when the difference between the conveyance speed detected by the conveyance speed detection means and the speed detected by the abutting speed detection means is a predetermined value or more. The sheet processing apparatus according to claim 3.   3. The sheet processing apparatus according to claim 2, wherein the speed control unit terminates the speed control of the folding conveyance unit according to a detection result of the projection speed detection unit when the projection member moves by a predetermined amount.   3. The speed control unit according to claim 2, wherein the speed control unit starts speed control of the folding conveyance unit according to a detection result of the thrust speed detection unit after a predetermined time has elapsed since the movement unit started to operate. Sheet processing device.   The sheet processing apparatus according to claim 1, wherein the moving unit includes a DC motor whose speed changes according to a load.

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