Sheet binding device and image forming system

Abstract

To provide a sheet binding device that can prevent incomplete binding of sheet bundles. [Solution] A sheet binding device for binding sheet bundles, comprising: a manual feed setting section into which sheet bundles are inserted; a sensor for detecting when sheet bundles are set in the binding position of the manual feed setting section; a stapleless binding unit having a pair of crimping teeth that can move between a separated position and a crimping position, and performing binding processing on the sheet bundle set in the binding position by moving the pair of crimping teeth from the separated position to the crimping position; and a control unit for controlling the stapleless binding unit, wherein the control unit continues the binding processing by the stapleless binding unit when it determines that the crimping teeth have come into contact with the sheet bundle and crimping has started, and then detects the movement of the sheet bundle by the sensor.

Description

Technical Field

[0001] The present invention relates to a sheet binding device and an image forming system including a binding unit that binds a sheet bundle without using a needle.

Background Art

[0002] Conventionally, a sheet processing device that performs a binding process on a plurality of sheets on which an image is formed by an image forming device such as a copying machine or a printer is known.

[0003] Such a sheet processing device is known to use a so-called needle binding method in which a needle is used as a binding tool to bind the sheets, and a so-called needleless binding method in which the sheets are bound without using a needle as a binding tool. And in a needleless binding device, there is known a sheet binding device in which a plurality of sheets (hereinafter, a sheet bundle) are inserted from the outside of the device into an insertion port, and manual binding (manual binding) is performed on the inserted sheet bundle by a needleless binding unit. The needleless binding unit can bind the sheet bundle without using a needle by biting the sheet bundle with a pair of crimping teeth.

[0004] This sheet binding device is provided with a set detection sensor that detects that the sheet bundle inserted into the insertion port is set in the correct position, and the binding process can be performed in a state where the sheet bundle is set in the correct position. However, a configuration in which the crimping teeth are separated when the set detection sensor is OFF (the position of the sheet is displaced) during the binding process is disclosed (Patent Document 1).

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0006] In the configuration of Patent Document 1 described above, if the set detection sensor turns OFF between the time the crimping teeth contact the sheet bundle and the start of crimping, and the completion of the binding process, the crimping teeth will separate, potentially resulting in a sheet bundle that is only partially bound and has weak fastening force. In that case, even if the binding process is repeated at the same position using the stapleless binding unit, it is difficult to bind the sheet bundle. The object of the present invention is to provide a sheet binding device that can suppress the occurrence of incomplete binding of a sheet bundle when manual binding is performed using a stapleless binding unit. [Means for solving the problem]

[0007] A typical configuration according to the present invention for achieving the above objective is a sheet binding device for binding sheet bundles, comprising: a manual feed set section into which sheet bundles are inserted; a sensor for detecting that sheet bundles are set at the binding position of the manual feed set section; a stapleless binding unit having a pair of crimping teeth that can move between a separated position and a crimping position, and performing a binding process on the sheet bundle without using staples by moving the pair of crimping teeth from the separated position to the crimping position with respect to the sheet bundle set at the binding position; and a control unit for controlling the stapleless binding unit, wherein the control unit stops the movement of the crimping teeth from the separated position to the crimping position if it detects movement of the sheet bundle by the output of the sensor before it determines that the crimping teeth have come into contact with the sheet bundle and crimping has started, and continues the binding process by the stapleless binding unit if it detects movement of the sheet bundle by the output of the sensor after it has determined that the crimping teeth have come into contact with the sheet bundle and crimping has started. [Effects of the Invention]

[0008] In this invention, by completing the crimping process after it has started to crimp the sheets onto the bundle, incomplete binding can be suppressed. [Brief explanation of the drawing]

[0009] [Figure 1]Diagram illustrating the overall configuration of the image forming system according to an embodiment of the present invention. [Figure 2] Diagram illustrating the configuration of a sheet processing device in an image forming system according to an embodiment of the present invention. [Figure 3] Top view of the stack tray and processing tray. [Figure 4] Perspective view of the sheet processing device [Figure 5] Diagram illustrating the configuration of a stapleless stapling unit. [Figure 6] Operational diagram of a stapleless stapling unit [Figure 7] Operational diagram of a stapleless stapling unit [Figure 8] Diagram illustrating the sensor mechanism for detecting sheet bundle insertion at the manual feed slot. [Figure 9] Diagram illustrating the state of moving the sheet stack in the manual feed slot. [Figure 10] Block diagram of stapleless binding control configuration [Figure 11] Flowchart of the operation procedure for stapleless binding. [Figure 12] Operation timing chart for stapleless binding process [Figure 13] Flowchart of the operation procedure for stapleless binding. [Figure 14] A graph showing the relationship between the number of stapleless stapling operations and the time required for stapleless stapling. [Modes for carrying out the invention]

[0010] <First Embodiment> Preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings. In the accompanying drawings, identical or similar components are denoted by the same reference numerals.

[0011] [Image Forming System] FIG. 1 is an explanatory diagram of the overall configuration showing the entire configuration of the image forming system 1000 from the front side. In this specification, unless otherwise specified, the front side is, as shown in FIG. 1, the side facing the user when operating the image forming system 1000. That is, the side where the operation unit 83 operated by the user is arranged is the front side. And in this specification, left and right refer to the left side and the right side (in the direction of arrow X in FIG. 1) when the image forming system 1000 is viewed from the front, and up and down refer to the upper side and the lower side (in the direction of arrow Y in FIG. 1: vertical direction) when the image forming system 1000 is viewed from the front.

[0012] The image forming system 1000 includes an image forming apparatus A and a sheet processing apparatus B as a post-processing apparatus that processes the sheet on which an image is formed by the image forming apparatus. The image forming system 1000 of the present embodiment further includes an external feeding apparatus D that supplies sheets to the image forming apparatus A.

[0013] [Image forming apparatus] The image forming apparatus A includes an image forming unit A1, an image reading unit A2, and an original document feeding unit A3. The image forming unit A1 is configured to form an image on a sheet by an inkjet printing mechanism, and includes a main body feeding unit 2, an image forming unit 3, a conveying unit 4, and a main body control unit.

[0014] Above the image forming unit A1, there are provided an image reading unit A2 having an image reading unit 5 inside, and an original document feeding unit A3 having an original document feeding unit that conveys the original document to the image reading unit A2. Further, on the front side of the image reading unit A2, there is provided an operation unit 83 that can be operated for the user to perform settings such as selection of the feeding destination. The operation unit 83 is provided with a touch panel 83a, and the user can instruct the processing content to the image forming apparatus A and the sheet processing apparatus B by touching the touch panel 83a. Note that in the present embodiment, only the operation unit 83 having the touch panel 83a is illustrated, but the operation unit 83 may be provided with various hard keys.

[0015] In this embodiment, the image forming apparatus A is a so-called internal discharge type, with the image forming unit 3, the transport unit 4, and the image reading device A2 arranged in a roughly U-shape. Therefore, between the image forming unit 3 and the image reading device A2 in the vertical direction of the image forming apparatus A, there is an internal space that is open to the left side (sheet processing device B side) and the front side in the figure. In this embodiment, a first relay transport unit A4 is installed in the internal space. The first relay transport unit A4 is a transport unit for transporting sheets discharged from the image forming apparatus A to the sheet processing device B, and is a unit that is attached to the image forming apparatus A when configuring an image forming system 10000 that connects the image forming apparatus A and the sheet processing device B. When the first relay transport unit A4 is not installed, the internal space of the image forming apparatus A becomes a so-called internal discharge space for loading sheets on which images have been formed by the image forming unit 3.

[0016] The main feeding unit 2 is equipped with multiple (two in this embodiment) feeding cassettes 2a and 2b that can be attached and detached. Each of the feeding cassettes 2a and 2b can accommodate sheets of different sizes. The main feeding unit 2 feeds sheets of the size instructed by the user via the operation unit 83 or external equipment from the corresponding feeding cassette and sends them to the image forming unit 3 via the feeding path 8.

[0017] The image forming unit A1 is equipped with a manual feed unit 9 in addition to the main feed unit 2. The manual feed unit 9 has a manual feed tray 9a located on the left side of the image forming apparatus A. The manual feed tray 9a is rotatable between an open position (solid line in Figure 1) and a closed position (dashed line in Figure 1) around a pivot axis 9c near its lower end when viewed from the front. Sheets loaded on the mounting surface 9b of the manual feed tray 9a in the open position (feeding position) are fed into the image forming unit A1 by a feed roller (not shown) located near the manual feed port of the image forming apparatus A, join the feed path 8, and are sent to the image forming unit 3. A feeding mechanism can be integrated into the manual feed tray 9a to allow for the loading of a larger number of sheets in an aligned state.

[0018] The feeder D, like the manual feed unit 9, is detachably connected to the left side of the image forming apparatus A. The feeder D can accommodate a larger number of sheets (for example, several hundred to several thousand) than the feed cassettes 2a and 2b of the main feed unit 2. Sheets fed from the feeder D merge into the feed path 8, similar to the manual feed unit 9, and are sent to the image forming unit 3. Furthermore, the sheet processing apparatus B is provided with a reversal tray 4f to reverse a sheet that has had an image formed on one side by the image forming unit 3, and to form an image on the other side as well.

[0019] The image forming unit 3 has units for each color, such as yellow, magenta, cyan, and black, and is capable of forming images on the conveyed sheet. In this embodiment, the image forming unit 3 refers to an inkjet head with each color unitized. The image forming unit 3 only needs to be configured to form images on sheets fed from the main feeding unit 2, the manual feeding unit 9, or the feeding device D, and various image forming mechanisms can be employed. In this embodiment, an inkjet type image forming unit is shown, but it is also possible to employ various other image forming mechanisms such as electrophotography, offset printing, and silk screen printing.

[0020] Image forming apparatus A has a feed path 8, a first transport path 4a, a second transport path 4b, a third transport path 4c, and a fourth transport path 4d as transport paths included in the transport section 4. The feed path 8 is a transport path through which sheets fed from the main feed section 2, the manual feed section 9, and the feed device D are transported to the image formation position by the image forming unit 3. The first transport path 4a is a transport path through which sheets are transported while images are formed by the image forming unit 3. The second transport path 4b is a transport path through which sheets with images formed on one side by the image forming unit 3 are transported to the inversion tray 4f. The third transport path 4c is a transport path through which sheets that have been switchback transported from the inversion tray 4f and have been inverted are transported back to the image forming section 3. The fourth transport path 4d is a transport path through which sheets with images formed on one or both sides are transported to the relay transport unit A4. As shown in the figure, each transport path is provided with multiple transport roller pairs, and each transport roller pair transports the sheets.

[0021] The fourth transport path 4d is connected to the relay transport path 4e, which is provided in the relay transport unit A4, so that sheets can be transferred to it. The relay transport path 4e is a transport path in which multiple pairs of transport rollers are arranged along the sheet transport direction, and the sheets are transported toward the feed port 12 (Figure 2) of the sheet processing device B.

[0022] Image reading unit A2 can read the image of a document placed on a platen glass (not shown) by irradiating it with light from a light source and inputting the reflected light to a CCD. Furthermore, by stopping at a scrolling reading position (not shown), image reading unit A2 can read the image of a document being transported by the automatic document feeder. The read document image is converted into an electrical signal and transmitted as image data to the image forming unit 3. The aforementioned platen glass (not shown) is exposed by rotating the document feeder upward.

[0023] [Sheet processing device]

[0024] As shown in Figure 1, the sheet processing device B is supported in the upper left corner of the image forming apparatus A. Furthermore, the sheet processing device B is fixed and supported to the image forming apparatus A so as to the left of the image reading unit A2 and the document feeding unit A3. The sheet processing device B is equipped with both an automatic binding function and a manual binding function. The automatic binding function uses a staple unit 17 (see Figure 2) to bind sheets transported from the image forming apparatus A, and discharges the bound sheets into the stack tray 40. The manual binding function uses a stapleless binding unit 27 (see Figure 3) to bind sheets inserted by the user from outside the apparatus into the manual feed slot 110. The configuration will be described below using Figures 2 and 3. In this embodiment, the staple unit 17 is an example of a first binding unit, and the stapleless binding unit 27 is an example of a second binding unit.

[0025] (Sheet transport route) As shown in Figure 2, the sheet processing device B is equipped with an input port 12 for receiving sheets discharged from the relay discharge port of the relay transport unit A4, and a sheet discharge port 13 for discharging sheets to the stack tray 40. The sheet transport path 11 is configured as a discharge path that transports sheets sent from the relay discharge port toward the stack tray 40, and a sheet end detection sensor Se1 for detecting the leading and trailing ends of the sheet, transport rollers 14a and 14b for transporting the sheets, and an upper transport path guide 28 and a lower transport path guide 29 for guiding the sheets transported by the transport rollers 14a and 14b are appropriately arranged along the path. The upper transport path guide 28 and the lower transport path guide 29 are arranged opposite each other to form a sheet transport path. In addition, each transport roller 14a and 14b is connected to a drive motor (not shown) and rotates when driven. The sheet transport path 11 shown is composed of a substantially straight path in a substantially horizontal direction. A processing unit 15 is provided on the upstream side of the discharge port 13 of this sheet transport path 11, and a stack tray 40 is provided on the downstream side.

[0026] (Processing tray) As shown in Figure 2, the processing unit 15 comprises a sheet stacking platform 16, alignment members 25 (25f and 25r), a staple unit 17, and a rear end regulating stopper 18. The sheet stacking platform 16 is positioned to form a step with respect to the stacking surface of the stack tray 40 and supports the stacking of sheets. The alignment members 25f and 25r are movable in the width direction of the sheets stacked on the sheet stacking platform 16 (the direction of arrow Z in Figure 3, and the front-to-rear direction of the sheet processing device B), and are a pair of alignment members that align the sheets stacked on the sheet stacking platform 16 in the width direction to correct misalignment of the sheet bundle. The staple unit 17 performs a stapling process on the sheet bundle formed by the sheets stacked on the sheet stacking platform 16 using staples. The rear end regulating stopper 18 restricts the movement of the downstream sheet end in the direction of sheet transport by the friction rotating body 19, which will be described later. In the processing unit 15, the sheet is supported (bridge-supported) across the stack tray 40 and the sheet loading platform 16. By arranging the stack tray 40 and the processing unit 15 on approximately the same plane, and supporting the leading edge of the sheet with one tray and the trailing edge with the other tray, the device can be made smaller compared to a configuration where the sheet is supported by a single tray.

[0027] The sheet loading platform 16 is equipped with a rear end regulating stopper 18 that abuts against and restricts the rear end of the sheet, and an alignment member 25 that aligns the sheet by bringing it closer in width in a direction perpendicular to the sheet discharge direction. Here, various alignment mechanisms are known for aligning the sheet in the width direction, but in this embodiment, the alignment member 25 enables sheet alignment and alignment by moving plate-shaped members (front alignment plate 25f and rear alignment plate 25r) protruding from the loading surface of the sheet loading platform 16 along guide grooves extending in the sheet width direction. The alignment member 25 positions the sheet loaded onto the sheet loading platform 16 at the aligned position. The illustrated device shows a configuration that performs alignment based on the center.

[0028] The processing unit 15 includes a stapling unit 17 as a post-processing means for stapling the sheet bundles accumulated on the sheet stacking platform 16. The stapling unit 17 is a device that bends the straight staples loaded in the staple cartridge 170 into a U-shape, inserts them from the top to the bottom of the sheet bundle, and bends the tips of the staples. The staple cartridge 170 is configured to be detachable from the stapling unit 17.

[0029] As shown in Figure 3, the staple unit 17 of this embodiment is configured to be movable in the front-rear direction, which is the direction of arrow Z in the figure. The staple unit 17 moves in the front-rear direction by moving along a guide groove (not shown) of the support member 32. The staple unit 17 can perform multiple types of stapling on the sheet bundle formed on the sheet stacking platform 16, such as front corner stapling, rear corner stapling, and two-point parallel stapling. Front corner stapling is performed by the staple unit 17 stapling the front corner of the sheet bundle AS at the stapling position shown by the solid line in Figure 3. Rear corner stapling is performed by the staple unit 17 stapling the rear corner of the sheet bundle at the stapling position shown by the dashed line on the rear side in Figure 3. Two-point parallel stapling is performed by stapling at two locations on the edge along the sheet edge that the rear end regulating stopper 18 contacts (the stapling position of the staple unit 17 shown by the dashed line between the solid line on the front side and the dashed line on the rear side in Figure 3).

[0030] A reversing roller mechanism 20 is positioned at the discharge port 13 of the sheet transport path 11. This reversing roller mechanism 20 reverses the transport direction when the rear end of the sheet (the upstream end in the sheet transport direction by the transport roller 14b) has passed the sheet end detection sensor Se1 and been transported a predetermined amount, and has passed the nip of the discharge roller 14c. As a result, the sheet is transported in the opposite direction to the discharge direction of the discharge roller 14c and guided along the sheet stacking platform 16 of the processing unit 15 to the rear end restricting stopper 18.

[0031] The processing unit 15 is equipped with a friction rotating body 19 that cooperates with a reversing roller mechanism 20 located at the discharge port 13 to guide the sheet to the rear end restricting stopper 18. The friction rotating body 19 is positioned to contact the sheet loaded on the sheet loading platform 16. The friction rotating body 19 is configured as a scraping roller and is driven by a drive belt (not shown) so as to rotate together with the discharge roller 14c. The friction rotating body 19 is in contact with the sheet loaded on the sheet loading platform 16 due to its own weight. The sheet, which is conveyed by the reversing roller 20 in the direction toward the rear end restricting stopper 18, is conveyed to the rear end restricting stopper 18 by the rotation of the friction rotating body 19, which is a scraping roller, and abuts against the rear end restricting stopper 18.

[0032] (Reversing roller mechanism) The reversing roller mechanism 20 includes an upper roller 21 that contacts the upper surface of the sheet conveyed by the conveying roller 14c, and a lower roller 22 that contacts the lower surface of the sheet conveyed by the conveying roller 14c. The reversing roller mechanism 20 conveys the sheet in the sheet discharge direction, which is the same direction as the conveying direction by the conveying roller 14c, and then switches the conveying direction to the opposite direction to deliver the sheet to the processing unit 15. The upper roller 21 is pivotably supported with respect to the device frame and is configured to move up and down between an operating position in contact with the lower roller 22 and a standby position separated from it. The upper roller 21 is rotated by the rotation of a roller drive motor (forward / reverse motor) to discharge the sheet toward the stack tray 42 in a first rotation direction (clockwise in the illustration) and a second rotation direction (counterclockwise in the illustration) which is opposite to the first rotation direction.

[0033] The device frame, which is the support frame of the sheet processing device B, supports a pair of left and right roller brackets (oscillating arms) 24 so as to be able to swing around an oscillating pivot point 23. A roller rotation shaft is rotatably supported on this pair of roller brackets 24 via bearings. An upper roller 21 is fitted onto the rotation shaft supported by the pair of roller brackets 24, and the upper roller 21 is rotatable relative to the pair of roller brackets 24 by the rotation shaft. The oscillating pivot point 23 is supported on the device frame by a rotatable or fixed means. The roller brackets 24 are fitted directly to the oscillating pivot point 23 or fitted via a collar member. As a result, the upper roller 21 supported on the pair of roller brackets 24 is supported so as to be able to swing in any angular direction around the oscillating pivot point 23. In addition, a collar member is loosely fitted to the rotation shaft 23, and a drive pulley (not shown) that transmits rotation to the rotation shaft of the upper roller 21 is connected to this collar member. A roller drive motor is connected to the drive pulley.

[0034] The upper roller 21 and lower roller 22 described above discharge the sheets conveyed by the discharge roller 14c to the sheet stacking table 16 so that the ends of the sheets contact the rear end restricting stopper 18. After that, the bundles of sheets that have been accumulated on the sheet stacking table 16 and subjected to various processes such as binding are discharged from the sheet stacking table 16 to the stack tray 40 by the reversing roller mechanism 20.

[0035] In the description above, the sheet bundles accumulated in the processing unit 15 are bound together and then transported to the stack tray 40 by the reversing roller mechanism 20. However, it is also possible to arrange a conveyor mechanism together with the reversing roller mechanism 20 to unload the sheet bundles from the processing unit 15.

[0036] [Stapleless stapling device] Next, the manual binding function will be explained using Figures 3 and 4. The sheet processing device B is equipped with a manual binding function that uses a stapleless binding unit 27 to bind sheets inserted by the user from outside the device into the manual feed slot. In this embodiment, the staple unit 17 used when performing the automatic binding function and the stapleless binding unit 27 used when performing the manual binding function are housed in the sheet processing device B, but they may be housed in separate enclosures. As shown in Figure 4, the stapleless binding unit 27 is provided between the front cover 10a and the front sheet metal 30f of the sheet processing device B. The stapleless binding unit 27 is for performing stapleless binding on the corners of the sheet bundle MS inserted into the feed slot 110 from the outside (front side) of the sheet processing device B.

[0037] (Insertion opening) The insertion opening 110 is a slit shape extending in the direction of arrow X in Figure 4 on the front cover 10a, and consists of an upper restricting portion 110b that restricts the upper surface of the sheet bundle MS, a lower restricting portion 110c that restricts the lower surface of the sheet bundle MS, and a right-side abutment portion 110a against which the right-side end of the sheet bundle MS abuts.

[0038] Furthermore, a detection mechanism (details to be described later) is provided on the inside (rear side) of the front cover 10a to detect when a sheet bundle MS has been inserted into the insertion slot 110. When this detection mechanism detects that the sheet bundle MS has been set, and the user presses button 111, the stapleless stapling unit 27 performs stapleless stapling on the sheet bundle MS. As shown in Figure 4, button 111 is located on the front side of the front cover 10a, above the insertion slot 110 in the vertical direction. Also, button 111 is positioned to the right of the center of the insertion slot 110 in the direction of arrow X, on the side of the right abutment portion 110a, and to the left of the right abutment portion 110a. In this embodiment, button 111 is an example of an operation button operated by the user when executing the manual stapling function.

[0039] By positioning button 111 in this location, the user can easily insert the sheet bundle MS into the insertion slot 110, support the sheet with the right end of the sheet bundle MS against the right abutment part 110a, and press button 111 with their right thumb.

[0040] (Stapling unit without staples) As shown in Figure 5, the stapleless stapling unit 27 of this embodiment performs the stapling process by sandwiching the sheet surface of the sheet bundle from both sides between a pressing part (crimping teeth) 50a provided on the fixed member 50 and a pressing part (crimping teeth) 51a provided on the movable member 51. For this reason, the movable member 51 is pivotably supported around a support shaft 52, and the support shaft 52 is fixed to the fixed member 50.

[0041] Furthermore, the fixed member 50 is integrally fixed to the device frame. The pressurizing portion 50a of the fixed member 50 and the pressurizing portion 51a of the movable member 51 move between a standby position separated from the sheet bundle (see Figure 6(a)) and a pressurizing position that clamps the sheet bundle (see Figure 7(b)) as the movable member 51 swings around the pivot shaft 52.

[0042] The device shown in Figure 5 has a fixed member 50 formed from a frame member with a U-shaped cross-section, and a movable member 51 is supported between its side walls so as to be able to swing around a pivot shaft 52. A return spring 53 is arranged on the movable member 51 to bias it toward the standby position. This return spring 53 is positioned between the movable member 51 and the device frame.

[0043] The pressurizing sections 50a and 51a are each composed of an uneven surface (protrusions and grooves) at least one of which deforms the pressed sheet. In this embodiment, each of the pressurizing sections 50a and 51a is formed of an uneven surface, and its shape is such that the protrusions and recesses interlock with each other. The shape of each uneven surface is designed to prevent damage to the sheet bundle MS when pressed (especially the edge shape), while simultaneously being configured to be the optimal shape that causes the overlapping sheets to deform in a way that allows them to interlock. The sheet bundle MS, when pressed between these uneven surfaces, retains a gathered (wave-shaped) deformation, and the overlapping sheets are bound together.

[0044] The movable member 51, which is pivotably supported by the fixed member 50, has a pressurizing portion 51a at its tip, separated by a support shaft 52, and a follower roller (cam follower) 54 at its base end. The pressurizing portion 51a and the follower roller 54 are formed to the length of a lever through which a lever action is exerted via the support shaft 52.

[0045] Furthermore, a cam member 55 is positioned at the base end of the fixed member 50. The cam member 55 is supported by a cam shaft 55a, which is rotatably supported by the fixed member 50, and the cam member 55 and the follower roller 54 are positioned in a mutually engaging relationship. The rotation of the stapleless stapling motor 57 is transmitted to the cam shaft 55a via a gear train 56, and the cam member 55 rotates in the forward and reverse directions with the forward and reverse rotation of the drive motor. As a result, the cam surface 55b presses against the follower roller 54, causing the movable member 51 to swing.

[0046] When the stapleless stapling motor 57 is driven and the cam member 55 rotates, the cam surface 55b holds the pressurizing portion 51a in the standby position from the standby position shown in Figure 6(a) to the oscillation start position shown in Figure 6(b) without applying any oscillation force to the follower roller 54 of the movable member 51. During this time, the drive of the stapleless stapling motor 57 is stabilized. After that, from the oscillation start position shown in Figure 6(b), a force is applied to press the follower roller 54 and cause the movable member 51 to oscillate (Figure 6(c)).

[0047] Then, as shown in Figure 7(a), the pressurizing unit 51a starts pressurizing the sheet bundle MS, and at the pressurizing position shown in Figure 7(b), the maximum pressurizing force is applied to the sheet bundle MS to end the pressurizing operation. After that, the return operation is performed by the clockwise rotation of the cam member 55.

[0048] (Sheet insertion detection mechanism) When performing stapleless stapling using the aforementioned stapleless stapling unit 27, the sheet bundle MS inserted from the insertion slot 110 must be set in the correct position. For this purpose, as shown in Figure 8, a sheet insertion detection mechanism 112 is provided to detect whether or not the sheet bundle MS is set in the stapling position of the insertion slot 110. Figures 8(a) to 8(e) are schematic cross-sectional views of the insertion slot 110 as seen from above. Although the reference numerals for each component are only shown in Figure 8(a), the same reference numerals are used in Figures 8(b) to 8(e).

[0049] The insertion detection sensor mechanism of this embodiment includes a right-side sensor mechanism 112a and a rear-side sensor mechanism 112b. The right-side sensor mechanism 112a and the rear-side sensor mechanism 112b are each composed of levers 113a, 113b that the seat contacts, sensor flags 114a, 114b, rotating shafts 115a, 115b, and seat presence / absence detection sensors 116a, 116b (transmissive sensors).

[0050] The right-side sensor mechanism 112a is a sensor mechanism corresponding to the right-side abutment portion 110a, and detects whether the sheet bundle MS inserted into the insertion opening 110 is abutting against the right-side abutment portion 110a (or the movable restricting surface 117). The rear-side sensor mechanism 112b is a sensor mechanism corresponding to the rear-side abutment portion 110f, and detects whether the sheet bundle MS is abutting against the rear-side abutment portion 110f. When the control unit, described later, detects from the output signals from both sensor mechanisms that the sheet bundle MS is abutting against each restricting surface, it determines that the sheet bundle MS has been set in the correct binding position and that the stapleless binding process by the stapleless binding unit 27 can be executed.

[0051] Since each sensor mechanism has the same configuration, the rear sensor mechanism 112b will be used as the basis for this explanation. A lever 113b and a sensor flag 114b are formed on the rotating shaft 115b, and when the rotating shaft 115b rotates, the lever 113b and the sensor flag 114b also rotate. A spring member (not shown) is provided on the rotating shaft 115b, and the shaft is spring-biased so that it is in the state shown in Figure 8(a) when the sheet is not in contact with it. When the sheet bundle MS is inserted into the insertion opening 110 and the rear end of the sheet bundle MS comes into contact with the lever 113b (Figure 8(c)), the rotating shaft 115b rotates against the biasing force of the spring member, and the sensor flag 114b moves to a position that blocks the optical axis of the sheet presence detection sensor 116b, detecting that the sheet bundle MS has come into contact with the rear abutment portion 110f. The right-side sensor mechanism 112a has a similar mechanism, and when the sensor flag 114a moves to a position that blocks the optical axis of the sheet presence detection sensor 116a, it is detected that the sheet bundle MS has come into contact with the right-side abutment part 110a (or the movable restricting surface 117 described later).

[0052] The movable restricting surface 117 is movable in the left-right direction of the arrow X, and can move between the first position shown in Figures 8(a) and 8(c) and the second position shown in Figures 8(b) and 8(d). By moving the movable restricting surface 117 between the first and second positions, the position at which the pressurizing portion 51a of the movable member 51 contacts the sheet bundle MS can be changed by a distance L1. For example, if you want to increase the fastening force of the stapleless binding process, you can increase the fastening force by performing the stapleless binding process at two different locations. Also, if you want to unfasten a sheet bundle MS that has already been stapled, read it as a document into the image reading unit A2, and then perform the stapleless binding process again, the fastening force will be weak if you perform the stapleless binding process at the exact same location. Therefore, in that case, you can fasten the sheet bundle MS again by shifting the position and performing the stapleless binding process (see Figure 8(e)).

[0053] Furthermore, the movable restricting surface 117 moves integrally with the right-side sensor mechanism 112a to a first position and a second position. This allows detection of whether the right end of the sheet bundle MS is set in the correct binding position in both the first and second positions. The movable restricting surface 117 and the right-side sensor mechanism 112a may be moved manually by the user using a lever (not shown) provided on the front-side cover 121, or they may be moved by button operation using a separate drive mechanism.

[0054] (Stapleless binding control configuration) In this embodiment, when performing stapleless stapling using the stapleless stapling unit 27, the sheet insertion detection mechanism 112 detects whether the sheet bundle is set in the correct stapling position. If it is determined that the sheet bundle is set in the correct stapling position, the stapleless stapling process is executed. If it is determined that the sheet bundle is not set in the correct stapling position, the stapling process is not executed.

[0055] The stapleless stapling unit 27 of this embodiment is configured to clamp the sheet bundle with strong pressure using a pair of crimping teeth (pressure parts 50a, 51a) to press the sheets together. Therefore, in this embodiment, multiple gears are arranged between the stapleless stapling motor 57 and the cam member 55 to increase the reduction ratio, thereby obtaining a large torque even with a small motor. Consequently, it takes about 1.5 to 2 seconds from when the pressure part 51a starts moving from the separated position to the crimping position until the crimping of the sheet bundle is completed (the time taken from t1 to t4 in Figure 12). For this reason, when the button 111 is pressed by the user to execute the stapling operation after the sheet bundle has been set in the stapling position, the user may move the sheet bundle. In contrast, the staple unit 17 using staples does not require clamping the sheets with strong pressure compared to the stapleless stapling unit 27, and its reduction ratio is not as high as that of the stapleless stapling unit 27, so the time required for stapling is shorter, and in particular, the time from when the staple contacts the sheet bundle until the stapling process is completed is shorter than that of the stapleless stapling process. Therefore, in stapleless stapling, there is a high possibility that the sheet stack will move after the stapling operation is performed.

[0056] In the case of stapleless stapling, if the sheet is completely pulled out, performing the stapling process afterward will result in the pressure parts 50a and 51a directly contacting each other and failing to staple properly because there is no sheet. Therefore, it is possible to consider stopping the stapling process if the sheet insertion detection mechanism 112 turns OFF after the stapling operation has been performed.

[0057] After the user presses button 111 to start the binding process and the pressurizing unit 51a contacts the sheet bundle MS to begin the crimping binding process (after the pressurizing operation starts with the sheet bundle MS being sandwiched between the pressurizing units 50a and 51a), the sheet insertion detection mechanism 112 may turn OFF by slightly moving the sheet bundle. In this case, as shown in Figure 9, the sheet bundle MS is often still within the pressurizing area of ​​the pressurizing unit 51a. If the binding process is stopped and the pressurizing unit 51a is separated before the crimping process is completed in this state (between ts and t4 in Figure 12), the sheet bundle MS will be bound with insufficient fastening force, resulting in an incomplete binding process. Therefore, in this embodiment, even if the sheet insertion detection mechanism 112 turns OFF after the stapleless binding process has started, the binding process is continued in certain cases to prevent the sheet bundle MS from being bound insufficiently. Next, the binding process control for this purpose will be explained.

[0058] Figure 10 is a block diagram showing the configuration of the stapleless stapling processing control unit. The control CPU 70 is connected to a ROM that stores the operation program shown in the flowchart of Figure 11, and a RAM that stores control data, and controls the drive circuit of the stapleless stapling motor 57. This control transmits the detected value (output value of the speed detection sensor) of the encoder located on the drive shaft of the stapleless stapling motor 57 to the CPU 70. The CPU 70 calculates the amount of movement (number of pulses) and rotational speed from the output value of the speed detection sensor 73. For this reason, the CPU 70 is equipped with means for measuring the amount of movement. It is also equipped with a current / voltage conversion circuit 72 that detects the current value of the stapleless stapling motor 57 and converts it into a voltage, and feeds back the load voltage to the CPU 70.

[0059] The home position sensor 74 detects the initial position of the pressurized portion 51a of the movable member 51. The sheet presence detection sensor 116 detects whether a sheet is inserted into the sheet insertion opening 110.

[0060] Furthermore, the CPU 70 is equipped with a counter that measures the amount of movement from the time it receives the command to start the stapleless binding operation until the sheet presence detection sensor 116 stops detecting a sheet.

[0061] Next, the binding process control procedure by the stapleless binding processing control unit will be explained based on the flowchart shown in Figure 11.

[0062] For stapleless stapling, the user inserts the sheet bundle MS into the insertion slot 110 and presses button 111 to execute the stapling process. When the control unit receives the stapleless stapling signal (S1), it determines whether the sheet bundle MS is correctly set (S2). If the right-side sensor mechanism 112a and the rear-side sensor mechanism 112b do not detect the sheet bundle MS, the control unit determines that the sheet bundle MS is not correctly set and terminates without executing the stapling process.

[0063] When the sheet presence detection sensors 116a and 116b are ON, the sheet bundle MS is assumed to be correctly set in the insertion slot 110, and the stapleless stapling motor 57 is driven in the forward direction (S3). As a result, the cam member 55 rotates, and the pressurizing portion 51a of the movable member 51, which is in the home position, moves toward the pressurizing portion 55a of the fixed member 50.

[0064] If the user does not move the sheet bundle MS between the start and end of the stapleless stapling process (NO in S4), the sheet bundle MS is held and pressed by the pressurizing units 50a and 51a and the stapleless stapling process is performed (S5). Once the stapling process is complete, the stapleless stapling motor 57 is driven in reverse to return the movable member 51 to the home position, the motor is stopped and the stapling process is terminated (S6-S8).

[0065] Here, the load voltage and speed changes of the stapleless stapling motor 57 when the stapleless stapling process is performed will be explained. Figure 12 is a timing chart showing the operating states of (1) the sheet presence detection sensors 116a and 116b, (2) the button 111, (3) the load voltage of the stapleless stapling motor 57, (4) the rotational speed of the stapleless stapling motor 57, and (5) the home position sensor that detects whether the movable member 51 is in the home position when the stapleless stapling process is performed.

[0066] When button 111 is pressed, the stapleless stapling motor 57 starts rotating and rotates the cam member 55. The motor starts during period t1-t2, and during period t2-t3, even though the movable member 51 is moving, the pressurizing part 51a has not yet come into contact with the sheet bundle MS, so the load on the motor is small and the motor load voltage is also small during this period. During period t3-t4, the pressurizing part 51a comes into contact with the sheet bundle MS and the stapling process is performed by clamping and pressing with the pressurizing parts 50a and 51a. At this time, the motor load increases, and the load voltage rises accordingly, while the motor rotation speed decreases. Then, at t4, the stapling process is completed, and during period t5-t6, the stapleless stapling motor 57 reverses direction to rotate the cam member 55 in the reverse direction and return the movable member 51 to the home position.

[0067] (Discrimination based on motor load voltage) As described above, when the pressurizing portion 51a of the movable member 51 contacts the sheet bundle MS and applies pressure, the load voltage and the rotational speed of the motor change. Therefore, whether or not the crimping and stapling process has started when the pressurizing portion 51a contacts the sheet bundle MS can be determined by the load voltage or rotational speed of the stapleless stapling motor 57 after a predetermined time has elapsed since the pressurizing portion 51a started moving. Specifically, as shown in Figure 12, it can be determined that the crimping and stapling process has started when the load voltage becomes greater than the threshold Vs (1.5V in this embodiment) after the motor has started and its operation has stabilized (t2). Similarly, it can be determined that the crimping and stapling process has started when the rotational speed of the motor becomes less than the threshold speed Rs.

[0068] In the stapleless stapling process shown in the flowchart above, if either the sheet presence detection sensor 116a or 116b turns OFF after the stapling process has started (YES in S4), that is, if the user moves the sheet bundle MS after the stapling process has started, it is determined whether or not the pressurizing process of the sheet bundle MS by the pressurizing unit 51a has started (S9). In this embodiment, if the load voltage of the stapleless stapling motor 57 is less than or equal to the threshold voltage Vs (YES in S9), it is assumed that the pressurizing process has not started as the pressurizing unit 51a has not yet come into contact with the sheet bundle MS, and the process proceeds to step S6 to cancel the stapleless stapling process and return the movable member 51 to the home position. Note that there are cases where a curled sheet is in contact with the pressurizing unit 51a, but in this embodiment, the state in which the pressurizing unit 50a and the pressurizing unit 51a are sandwiching the sheet bundle MS and applying pressure is called the pressurizing process, and the timing when the top sheet of the sheet bundle MS is in contact with the pressurizing unit 51a but no pressure is being applied is considered as not having started the pressurizing process. In other words, if the pressure section 50a and 51a are not applying a load to the sheet bundle MS when the sheet bundle MS is moved from the binding position, then the pressure processing is considered not to have started.

[0069] On the other hand, if either the sheet presence detection sensor 116a or 116b turns OFF at the timing ts shown in the timing chart of Figure 12, that is, if the load voltage of the stapleless stapling motor 57 is greater than the threshold voltage in step S9 (NO in S9), it is determined that the pressurizing unit 51a has come into contact with the sheet bundle MS and pressurizing has started, and that the pressurizing process has begun. In this case, the process proceeds to step S5 and the pressurizing process is executed to perform stapleless stapling on the sheet bundle MS.

[0070] As described above, even if the user moves the sheet bundle MS after the binding process has started, the crimping process will continue as long as the crimping of the sheet bundle by the pressurizing units 50a and 51a has started. This prevents the sheet bundle MS from being partially bound, thereby suppressing the occurrence of binding defects.

[0071] In the above embodiment, it was determined that the pressurizing unit 51a had come into contact with the sheet bundle and crimping had started by detecting fluctuations in the load voltage of the stapleless stapling motor 57. However, as mentioned above, it is also possible to determine this by fluctuations in the rotational speed of the motor.

[0072] (Discrimination based on motor operating time) Whether or not the pressurizing unit 51a has come into contact with the sheet bundle and crimping has begun can also be determined by the driving time of the stapleless stapling motor 57. For example, in the timing chart of Figure 12, the stapleless stapling motor 57 starts driving at t1, and pressurizing by the pressurizing unit 51a begins from ts onward. Therefore, by setting ts as a threshold time, it is also possible to determine whether or not crimping to the sheet bundle MS has started based on whether or not the motor driving time after the start of the stapling process has exceeded the threshold time ts.

[0073] The procedure for determining whether or not crimping to the sheet bundle MS has started based on the driving time will be explained with reference to the flowchart shown in Figure 13.

[0074] The operation is almost the same as when the determination is made based on the drive voltage value described above. When a stapleless stapling signal is received, the stapleless stapling motor 57 is driven in the forward direction to move the movable member 51 and start the stapling process (S21-S23). Then, when the sheet presence detection sensors 116a and 116b turn OFF after the motor has started to drive (S24), it is determined whether the motor drive time is longer than the threshold time ts (S25). If the motor drive time is shorter than the threshold time, the stapling process is stopped. If it is longer, it is determined that the crimping process by the pressurizing units 50a and 51a has started and the stapling process is completed as is (S26-S30).

[0075] Here, when determining whether or not the crimping process has started based on the motor's operating time as described above, the number of stapling operations is counted each time the crimping process is performed (S27). If the number of stapling operations exceeds the set number, the threshold time described above is changed (S31, S32). This is because, when the stapleless stapling motor 57 is driven to rotate the cam member 55 via the gear train 56, thereby moving the movable member 51 and pressing the pressure unit 51a, as the number of stapling operations increases, the operating time of the stapleless stapling motor 57 required to move the movable member 51 by the same amount increases due to wear of parts, etc.

[0076] Therefore, in this embodiment, as shown in Figure 14, the threshold time ts is increased by a predetermined time according to the number of binding operations. This makes it possible to accurately determine whether or not the crimping process has started based on the motor's operating time, even if the number of binding operations increases and parts wear out.

[0077] In this embodiment, a stapleless binding control unit (CPU 70) is shown to be provided in the sheet processing device B, but the components of the stapleless binding unit 27 may be controlled by a control unit that controls the image forming apparatus A. [Explanation of Symbols]

[0078] A...Image forming apparatus B...Sheet processing device MS...sheet bundle 16... Sheet loading platform 17… Staple Unit 27... Stapleless stapling unit 50 ... Fixing member 50a ... Pressurized section 51 ...Movable member 51a ... Pressurized section 55 ... Cam component 57... Stapleless stapling motor 110 ... Insertion port 111 ... button 112 ... Sheet insertion detection mechanism 112a ... Right-side sensor mechanism 112b ... Rear sensor mechanism

Claims

1. A sheet binding device for binding stacks of sheets, The manual feed section into which the sheet bundle is inserted, A sensor that detects when a sheet bundle is set in the binding position of the manual feed setting section, A stapleless stapling unit having a pair of crimping teeth that can move between a separated position and a crimping position, which performs stapling on a sheet bundle set in the stapling position by moving the pair of crimping teeth from the separated position to the crimping position, The system includes a control unit for controlling the stapleless stapling unit, A sheet stapling device characterized in that, if the control unit detects movement of the sheet bundle by the output of the sensor before determining that the crimping teeth have come into contact with the sheet bundle and crimping has started, it stops the movement of the crimping teeth from the separated position toward the crimping position, and if it detects movement of the sheet bundle by the output of the sensor after determining that the crimping teeth have come into contact with the sheet bundle and crimping has started, it continues the stapling process by the stapleless stapling unit.

2. The sheet binding device according to claim 1, characterized in that the control unit determines that crimping by the crimping teeth has started when the load voltage value of the motor for moving the crimping teeth from the separated position to the crimping position exceeds a predetermined value a predetermined time after the crimping teeth start moving from the separated position to the crimping position.

3. The sheet binding device according to claim 1, characterized in that the control unit determines that crimping by the crimping teeth has started when the rotational speed of the motor for moving the crimping teeth from the separated position to the crimping position becomes slower than a predetermined speed after a predetermined time has elapsed since the crimping teeth started moving from the separated position to the crimping position.

4. The sheet binding device according to claim 1, characterized in that the control unit determines that crimping by the crimping teeth has started when a predetermined time has elapsed since the start of the binding process by the stapleless binding unit.

5. The system includes a counting means for counting the number of times the stapleless stapling unit has performed the stapling process, The sheet binding device according to claim 4, characterized in that the control unit changes to lengthen the predetermined time when the count value obtained by the counting means exceeds a predetermined number of times.

6. An image forming unit that forms an image on a sheet, The manual feed section into which the sheet bundle is inserted, A sensor that detects when a sheet bundle is set in the binding position of the manual feed setting section, A stapleless stapling unit having a pair of crimping teeth that can move between a separated position and a crimping position, which performs stapling on a sheet bundle set in the stapling position by moving the pair of crimping teeth from the separated position to the crimping position, The system includes a control unit for controlling the stapleless stapling unit, The image forming system is characterized in that, if the control unit detects movement of the sheet bundle by the output of the sensor before determining that the crimping teeth have come into contact with the sheet bundle and crimping has begun, it stops the movement of the crimping teeth from the separated position toward the crimping position; and if it detects movement of the sheet bundle by the output of the sensor after determining that the crimping teeth have come into contact with the sheet bundle and crimping has begun, it continues the stapling process by the stapleless stapling unit.

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