Sheet processing device and image generation device

Abstract

Sheet processing device with: a binding unit (102) a first section (1012) with a large number of first teeth (10214) and a second section (1029) with a plurality of second teeth (10210) opposite the first teeth (10214), wherein the binding unit (102) is designed to bind a leaf bundle by clamping the leaf bundle in a thickness direction between the first teeth (10214) and the second teeth (10210); and a detachment unit (10215, 10215A, 10215B, 10215C, 10215D, 10215E) which is constructed in such a way that it pushes the bound leaf bundle towards the second section (1029) so that the bound leaf bundle is detached from the first section (1012).

Description

BACKGROUND OF THE INVENTIONField of the invention

[0001] The present invention relates to a sheet processing apparatus and an image forming apparatus, and more particularly to an apparatus configured to bind sheets together without the use of a stapler or other external device. Description of the related prior art

[0002] Conventionally, some image forming devices such as copiers, laser printers, fax machines, and multifunction peripherals, as well as combinations thereof, have been equipped with a sheet processing device configured to perform a binding process on the sheets. Generally, such image forming devices bind a bundle of sheets by using a metal staple. Such stapling allows a plurality of output sheets to be securely bound at a position specified by the user and is therefore widely used in sheet processing devices.

[0003] However, although the stapling or stapling process using a metal staple allows the bundle of sheets to be securely bound, a special tool must be used to separate the bundle of sheets once it has been bound by this process. Furthermore, this process requires a staple removal operation before the stapled or stapled sheets are placed in a shredder. Similarly, when the stapled bundle of sheets is recycled, the staple must also be removed, and the sheets and staple should be collected separately.

[0004] Therefore, among conventional sheet processing devices, devices configured to bind sheets without using a staple are proposed, particularly with regard to recyclability. These sheet processing devices include, for example, devices configured to perform a binding process on a sheet bundle by a binding unit having V-shaped upper teeth and inverted V-shaped lower teeth (see Japanese Patent Application Laid-Open Nos. 2010-189101 A and 2011-201653 A).

[0005] According to these sheet processing devices, after the sheets are bundled and aligned with each other, the lower teeth and the upper teeth of the binding unit are engaged with each other to form an uneven surface at a portion of the sheet bundle in a thickness direction, to cause the respective fibers of the stacked sheets in the sheet bundle to be entangled with each other, thereby binding the sheet bundle. In other words, these sheet processing devices are configured to bind fiber sheets without using a staple. Hereinafter, the term "staple-free binding" is used to refer to this method of binding a fiber sheet bundle without using a staple.

[0006] However, according to these conventional sheet processing devices, increasing the applied force to secure the sheets more securely results in the sheet bundle sticking to the teeth. The sheet bundle sticking to the teeth causes problems such as hindering the conveyance of the sheet bundle for output to the user for accumulation or to a next step in the printing process. SUMMARY OF THE INVENTION

[0007] The present invention is directed to a sheet processing device capable of preventing sheets from sticking to teeth when the sheets are bound.

[0008] According to one aspect of the present invention, there has been provided a sheet processing apparatus according to claim 1.

[0009] Further features of the present invention will become apparent from the following description of the embodiments with reference to the accompanying drawings. Each of the embodiments of the present invention described below may be implemented individually or as a combination of a plurality of the embodiments or their features, if necessary, or if the combination of elements or features from individual embodiments is advantageous in a single embodiment. BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 shows a structure of an image forming apparatus including a sheet processing apparatus according to an embodiment of the present invention. The Fig. 2A and Fig. 2B show a finishing device which is the sheet processing device. The Fig. 3A and Fig. 3B show a structure of a staple-free binding unit mounted on the finishing device. The Fig. 4A and Fig. 4B show an operation of the staple-free binding unit. Fig. 5 shows shapes of lower teeth and upper teeth of the staple-free binding unit. Fig. 6 shows a control block diagram of the image forming apparatus. Fig. 7 shows a control block diagram of the finishing device. The Fig. 8A, Fig. 8B and Fig. 8C shows a sheet binding process operation by the finishing device. Fig. 9 shows a flowchart of a control of the staple-free binding process by the finishing control unit of the finishing device. Fig. 10 schematically shows states of surfaces of the lower teeth and the upper teeth. Fig. 11 shows a release leaf spring mounted on the staple-free binding unit. The Fig. 12A and Fig. 12B show a detachable portion and a non-detachable portion of the detachment leaf spring. The Fig. 13A and Fig. 13B shows a positional relationship between the lower teeth and the release leaf spring. The Fig. 14A and Fig. 14B shows a state of the release leaf spring during the staple-free binding process. Fig. 15 shows a structure of a staple-free binding unit mounted on a sheet processing apparatus according to a second embodiment of the present invention. Fig. 16A and Fig. 16B shows a state of a release leaf spring mounted on the staple-free binding unit during the staple-free binding operation. Fig. 17 shows a structure of a staple-free binding unit mounted on a sheet processing apparatus according to a third embodiment of the present invention. The Fig. 18A and Fig. 18B shows a state of a release leaf spring mounted on a staple-free binding unit during the staple-free binding process. Fig. 19 shows a structure of a staple-free binding unit mounted on a sheet processing apparatus according to a fourth embodiment of the present invention. The Fig. 20A and Fig. 20B shows a state of a release pin mounted on the staple-free binding unit during the staple-free binding process. Fig. 21 shows a structure of a staple-free binding unit mounted on a sheet processing apparatus according to a fifth embodiment of the present invention. Fig. 22 shows an enlarged view of main sections of the staple-free binding unit. The Fig. 23A and Fig. 23B show states of release wire springs mounted on the staple-free binding unit during the staple-free binding process. Fig. 24 shows another embodiment of the sheet binding device. DESCRIPTION OF THE EMBODIMENTS

[0010] In the following description, the embodiments of the present invention are described in detail with reference to the drawings. Fig. 1 shows a structure of an image forming apparatus having a sheet processing apparatus according to a first embodiment of the present invention.

[0011] With reference to Fig. 1, an image forming apparatus 900 includes an image forming apparatus main body (hereinafter referred to as an apparatus main body) 900A and an image forming unit 900B configured to form an image on a sheet. An image reading apparatus 950 is disposed above the apparatus main body 900A and includes a document conveying apparatus 950A. A finishing apparatus 100 is a sheet processing apparatus disposed between an upper surface of the apparatus main body 900A and the image reading apparatus 950.

[0012] The image forming unit 900B includes photosensitive drums a to d configured to form toner images of four colors, namely, yellow, magenta, cyan, and black, and an exposure device 906 configured to emit a laser beam (laser beam bundle) based on image information to form an electrostatic latent image on each of the photosensitive drums a to d. Each of these photosensitive drums a to d is driven by a motor (not shown). Further, a primary charger, a developing device, and a transfer charger (not shown) are arranged around each of the photosensitive drums a to d. Each of the photosensitive drums a to d and these devices are configured as process cartridges 901a to 901d as a unit.

[0013] Further, the image forming unit 900B includes an intermediate transfer belt 902 configured to be rotationally driven in a direction shown by an arrow, a secondary transfer unit 903 configured to transfer an image in all colors sequentially formed on the intermediate transfer belt 902 onto a sheet P, and the like. Then, transfer bias voltages are applied to this intermediate transfer belt 902 by transfer chargers 902a to 902d, causing the toner images of the respective colors on the photosensitive drums a to d to be sequentially transferred onto the intermediate transfer belt 902 in a multi-layer manner. As a result, an image in all colors is formed on the intermediate transfer belt 902.

[0014] The secondary transfer unit 903 has a secondary transfer counting roller 903b that supports the intermediate transfer belt 902, and a secondary transfer roller 903a that contacts the secondary transfer counting roller 903b via the intermediate transfer belt 902. Referring to Fig. 1, registration rollers 909 and a sheet feed cassette 904 are provided. A pickup roller 908 feeds and conveys the sheet P contained in the sheet feed cassette 904. A central processing unit (CPU) control circuit 200 is a control unit that controls the device main body 900A and the finishing device 100.

[0015] Next, an image forming operation of the image forming apparatus 900 constructed in this manner will be described. Upon starting the image forming operation, first, the exposure device 906 outputs laser light based on image information from a personal computer (not shown) or the like, and sequentially exposes the surfaces of the photosensitive drums a to d that have been uniformly charged to have predetermined polarities and potentials, thereby forming electrostatic latent images on the photosensitive drums a to d. These electrostatic latent images are then developed by toner to be visualized.

[0016] For example, first, the exposure device 906 outputs laser light based on an image signal corresponding to a yellow component color on a document to the photosensitive drum a via a polygonal mirror of the exposure device 906 and the like, thereby forming a yellow electrostatic latent image on the photosensitive drum a. Then, this yellow electrostatic latent image is developed by a yellow toner from the developing device and is visualized as a yellow toner image. Thereafter, this toner image arrives at a primary transfer section where the photosensitive drum a is in contact with the intermediate transfer belt 902, according to rotation of the photosensitive drum a.At this time, when the toner image arrives at the first transfer unit in this manner, the yellow toner image on the photosensitive drum a is transferred to the intermediate transfer belt 902 by a primary transfer bias applied by a transfer charger 902a (a primary transfer).

[0017] Subsequently, as a portion of the intermediate transfer belt 902 carrying the yellow toner image moves, a magenta toner image formed on the photosensitive drum b this time in a similar manner to the above-described method is transferred to the intermediate transfer belt 902 from above the yellow toner image. Similarly, as the intermediate transfer belt 902 moves, a cyan toner image and a black toner image are each transferred to the intermediate transfer belt 902 at respective primary transfer portions while being superimposed on the yellow toner image and the magenta toner image. As a result, the toner image in all colors is formed on the intermediate transfer belt 902.

[0018] Furthermore, in parallel with this toner image forming process, the sheet P contained in the sheet feed cassette 904 is transferred one by one by the pickup roller 908. Then, the sheet P reaches the registration rollers 909 and is conveyed to the secondary transfer unit 903 after being synchronized by the registration rollers 909. Thereafter, the toner images of the four colors on the intermediate transfer belt 902 are collectively transferred onto the sheet P at this secondary transfer unit 903 by a secondary transfer bias applied to the secondary transfer roller 903a, which is a transfer unit (a secondary transfer).

[0019] Subsequently, the sheet P with the toner images transferred thereon is guided by the secondary transfer unit 903 to a conveyance guide 920 and is conveyed to a fixing unit 905. The sheet P receives heat and pressure while being transferred by the fixing unit 905, thereby fixing the toner images on the sheet P. Thereafter, the sheet P with the images thus fixed thereon is transferred through a discharge passage 921 located downstream of the fixing unit 905 and then discharged by a pair of discharge rollers 918 to be conveyed to the finishing apparatus 100.

[0020] The finishing device 100 receives sheets discharged from the device main body 900A sequentially (one after another). The finishing device 100 has a processing unit 139 configured to perform a process of aligning a plurality of received sheets with each other and bundling them into a single bundle (pile), and a binding process of binding the bundled sheet bundle at its upstream edge in a sheet discharge direction (hereinafter, referred to as a trailing edge). Furthermore, as shown in Fig. 2A and Fig. 2B, the processing unit 139 of the finishing device 100 performs the binding process as needed and also performs a process of discharging the sheets onto a sheet stacking tray 114. This processing unit 139 has an intermediate processing tray 107 as a sheet stacking unit configured to stack the sheets subjected to the binding process, and a binding processing unit 100A configured to bind the sheets stacked on the intermediate processing tray 107.

[0021] Furthermore, front and side alignment plates 109a and 109b are arranged on the intermediate process tray 107. The front and side alignment plates 109a and 109b regulate (and align) the positions of both side edges of the sheet P in a width direction (a lateral direction) after the sheet P is conveyed to the intermediate process tray 107 from a direction perpendicular to a lateral direction of the apparatus main body 900A. The front and side alignment plates 109a and 109b, which are a side edge alignment unit configured to align the positions of the side edges of the sheets P loaded on this intermediate process tray 107 in the width direction, are driven by an alignment motor M253 provided in Fig. 7 and described below, driven to be moved in the width direction.

[0022] Furthermore, these front and side alignment plates 109a and 109b are normally moved to receiving positions where they receive the sheet P by the alignment motor M253 driven based on a detection signal from an alignment home position (HP) sensor (not shown). Then, when the front and side alignment plates 109a and 109b regulate the positions of the two side edges of the sheet P loaded on the intermediate process tray 107, the alignment motor M253 is driven so that the front and side alignment plates 109a and 109b move along the width direction to contact the two side edges of the sheet P loaded on the intermediate process tray 107.

[0023] Furthermore, a pull-in vane 106 is arranged above a downstream side of the intermediate processing compartment 107 in the conveying direction. Before the sheet P is conveyed into the processing unit 139, a vane lifting motor M252 is driven based on detection information of a vane home position sensor S243 located in Fig. 7 and will be described below. This operation sets the pull-in vane 106 in a standby state at an upper position where it will not interfere with the discharged sheet P.

[0024] Furthermore, when the sheet P is discharged onto the intermediate process tray 107, the pull-in vane 106 is moved downward by driving the vane lift motor M252 in a reverse direction, and is also rotated counterclockwise by a vane motor (not shown) at an appropriate timing. This rotation enables the pull-in vane 106 to pull in the sheet P and bring the trailing edge of the sheet P into contact with a trailing edge stopper 108. In the present embodiment, this pull-in vane 106, the trailing edge stopper 108, and the front and side alignment plates 109a and 109b constitute an alignment unit 130 that aligns the sheet P loaded onto the intermediate process tray 107.For example, when the intermediate process tray 107 is highly inclined, the sheet P can be brought into contact with the trailing edge stopper 108 without the use of the pull-in wing 106 and a knurled belt 117 described below.

[0025] With reference to the Fig. 2A and Fig. 2B, a trailing edge support 112 is provided. This trailing edge support 112 is moved from a position where it does not interfere with the movement of a stapler, which will be described below, to a receiving position where it receives the sheet P by an assist motor M254 driven on the basis of a detection signal of an assist home position sensor S244 provided in Fig. 7 and described below. Then, this trailing edge support 112 outputs the sheet bundle to a sheet stacking tray 114 after the binding process has been performed on the sheet bundle, as described below.

[0026] Furthermore, the finishing device 100 has a pair of inlet rollers 101 for taking the sheet P into the device, and a sheet discharge roller 103. The sheet P discharged from the device main body 900A is transferred to the pair of inlet rollers 101. At this time, the sheet transfer time is also simultaneously detected by an inlet sensor S240. Then, the sheet P transferred to the pair of inlet rollers 101 is sequentially discharged to the intermediate process tray 107 by the sheet discharge roller 103 (i.e., a sheet discharge unit). The sheet P discharged onto the intermediate process tray 107 is brought into contact with the trailing edge stopper 108 by a reversing unit such as the pull-in vane 106 and the knurled belt 117. As a result, the sheets are aligned with each other in the sheet conveying direction, thereby forming an aligned sheet bundle.

[0027] With reference to the Fig. 2A and Fig. 2B, a trailing edge drop element 105 is provided. The trailing edge drop element 105 is pushed upwards by the sheet P passing the sheet discharge roller 103, as shown in Fig. 2A. Once the sheet P has passed the sheet discharge roller 103, the trailing edge drop member 105 falls down due to its own weight to push the trailing edge of the sheet P downward from above, as shown in Fig. 2B is shown.

[0028] Furthermore, a removal device 104 for removing static charge and a bundle holder 115 are provided. The bundle holder 115 is driven by a bundle holder motor M255, which is Fig. 7 and described below, thereby holding the sheet bundle stacked on the sheet stacking tray 114. Furthermore, a tray lower limit sensor S242, a bundle holder home position sensor S245, and a tray home position sensor S241 are provided. When the sheet bundle prevents light from being transmitted to the tray home position sensor S241, the sheet stacking tray 114 is raised by a tray lifting motor M251 located in Fig. 7, until the light can be transmitted to the tray home position sensor S241, thereby determining a sheet surface position.

[0029] A binding process unit 100A has a staple-free binding unit 102, which is a staple-free binding unit. As shown in Fig. As shown in FIG. 3A, the staple-free binding unit 102 includes a staple-free binding motor M257, a gear 1021 configured to be rotated by the staple-free binding motor M257, and step gears 1022 to 1024 configured to be rotated by the gear 1021. Further, the staple-free binding unit 102 includes a gear 1025 configured to be rotated by the step gears 1022 to 1024. Furthermore, the staple-free binding unit 102 has a lower arm 1012 fixed to a frame 10213 and an upper arm 1029 provided to be pivotable relative to the lower arm 1012 about an axis 10211 and biased toward the lower arm side by a biasing member (not shown). As shown in Fig. As shown in Figure 3B, lower teeth 10214 are provided as a first portion on the lower arm 1012. Upper teeth 10210 are provided as a second portion on the upper arm 1029.

[0030] The gear 1025 is attached to a rotary shaft 1026. In addition, as shown in Fig. 3B, a cam 1027 is attached to this rotary shaft 1026, and this cam 1027 is arranged between the upper arm 1029 and the lower arm 1012. With this structure, when the staple-free binding motor M257 rotates, the rotation of the staple-free binding motor M257 is transmitted to the rotary shaft 1026 via the gear 1021, the step gears 1022 to 1024, and the gear 1025, thereby causing the cam 1027 to rotate.

[0031] With reference to the Fig. 3A and Fig. 3B, the staple-free binding unit 102 switches between a binding state in which the staple-free binding unit 102 binds the plurality of sheets by biting them, and a release state in which the staple-free binding unit 102 releases the gripping (clamping) of the sheets. A moving unit 102A is a moving unit that moves the upper teeth 10210 between a binding position in which the upper teeth 10210 bind the sheet bundle together with the lower teeth 10214, and an open position in which the upper teeth 10210 are separated from the lower teeth 10214. The moving unit 102A has the staple-free binding motor M257, the cam 1027, the gear 1021, the step gears 1022 to 1024, and the gear 1025. In other words, the moving unit 102A changes the state of the staple-free binding unit 102 between the binding state and the release state.

[0032] In the present embodiment, the cam 1027 is in contact from below with a roller 1028 arranged at a pivotable end of the upper arm 1029. As a result, rotation of the cam 1027 causes the cam-side end of the upper arm 1029, which is brought into pressure contact with the cam 1027 via the roller 1028 by a biasing element (not shown), to be moved to the position shown in Fig. 4A shown state, is raised as shown in Fig. 4B is shown.

[0033] On the other hand, the upper teeth 10210 having a first tooth shape are provided at a bottom of one end of the upper arm 1029 on the opposite side of the cam 1027. The lower teeth 10214 having a second tooth shape are provided at an upper side of one end of the lower arm 1012 on the opposite side of the cam 1027. Referring to the Fig. 4A and Fig. 4B, a binding unit 201B has the upper teeth 10210 and the lower teeth 10214 on which a plurality of teeth are formed, and binds the plurality of sheets by clamping (gripping) them with the upper teeth 10210 and the lower teeth 10214. Furthermore, FIG. Fig. 5 the staple-free binding unit 102 viewed from a direction indicated by an arrow in Fig. 4B. The lower teeth 10214 have inverted letter V shapes (concave portions) as a deformation surface configured to deform the sheet bundle in a thickness direction by contact with the sheet bundle. The upper teeth 10210 have letter V shapes (convex portions) as the deformation surface configured to deform the sheet bundle in the thickness direction by contact with the sheet bundle. The binding unit 102B sandwiches the sheet bundle between the upper teeth 10210 and the lower teeth 10214 to deform the sheet bundle in the thickness direction, thereby binding the sheet bundle. In other words, the binding unit 102B clamps the sheet bundle between the upper teeth 10210 and the lower teeth 10214 to deform the sheet bundle in the thickness direction, thereby binding the sheet bundle.

[0034] When the cam-side end of the upper arm 1029 is moved upward by the cam 1027, the end of the upper arm 1029 opposite to the cam 1027 is moved downward. According to the downward movement of the end of the upper arm 1029 opposite to the cam 1027, the upper teeth 10210 are moved downward to engage with the lower teeth 10214, thereby pressing the sheet bundle. Then, as the sheet bundle is pressed in this manner, the sheet P is stretched so that a fiber on its surface is exposed. Further pressing of the sheet bundle causes the fibers of the sheets to intertwine / tangle with each other, thereby securing the sheets together.The upper teeth 10210 and the lower teeth 10214 are a pair of sandwich members (clamping members) configured to sandwich the sheet bundle to deform it in the thickness direction to thereby bind it.

[0035] In other words, when the staple-free binding unit 102 performs the binding process on the sheets, the upper arm 1029 is pivoted to cause the upper teeth 10210 on the upper arm 1029 and the lower teeth 10214 on the lower arm 1012 to grip (clamp) and press the sheets between them. The sheets are gripped (clamped) and pressed by the upper teeth 10210 and the lower teeth 10214, thereby securing them to each other. At this time, the position of the cam 1027 is controlled by a Fig. 7, which is described below.

[0036] Fig. 6 shows a control block diagram of the image forming apparatus 900. Referring to Fig. 6, the CPU circuit unit 200 is arranged at a predetermined position in the device main body 900A, as shown in Fig. 1. This CPU circuit unit 200 includes a CPU 201, a read / write memory (ROM) 202 that stores a control program and the like, and a random access memory (RAM) 203 that serves as an area for temporarily holding control data and as a work area for calculation required for control.

[0037] Furthermore, with reference to Fig. 6, an external interface 209 is an interface between the image forming apparatus 900 and an external personal computer (PC) 208. Upon receiving print data from the external PC 208, the external interface 209 rasterizes this data into a bitmap image and outputs the rasterized data to an image signal control unit 206 as image data.

[0038] Then, this image signal control unit 206 outputs this data to a printer control unit 207, and the printer control unit 207 outputs the data received from the image signal control unit 206 to an exposure control unit (not shown). An image on a document read by an image sensor (not shown) mounted on the image reading device 950 is output from an image reading controller 205 to the image signal control unit 206, and the image signal control unit 206 outputs this image output signal to the printer control unit 207.

[0039] Further, an operation unit 210 has a plurality of keys for setting various kinds of functions related to image formation, a display unit for displaying a setting / setting state, and the like.

[0040] Then, the operation unit 210 outputs a key signal corresponding to the user's application operation performed on each key to the CPU circuit unit 200, and also displays the corresponding information on the display unit based on a signal from the CPU circuit unit 200.

[0041] The CPU circuit unit 200 controls the image signal control unit 206 and also controls the document conveying device 950A (see FIG. Fig. 1) via a document feed control unit (DF control unit) 204 (i.e., a document conveying device) according to the control program stored in the ROM 202 and the settings of the operation unit 210. Furthermore, the CPU circuit unit 200 controls the image reading device 950 (see FIG. Fig. 1) via the image reading control unit 205, the image generation unit 900B (see Fig. 1) via the printer control unit 207 and the finisher 100 via a finisher control unit 220.

[0042] In the present embodiment, the finishing device control unit 220 is mounted on the finishing device 100 and drives and controls the finishing device 100 by exchanging information with the CPU circuit unit 200. Alternatively, the finishing device control unit 220 may be mounted on the device main body side integrally with the CPU circuit unit 200 and may be configured to control the finishing device 100 directly from the device main body side.

[0043] Fig. 7 shows a control block diagram of the finishing device 100 according to the present embodiment. The finishing device control unit 220 includes a CPU (i.e., a microcomputer) 221, a ROM 222, and a RAM 223. Furthermore, this finishing device control unit 220 communicates with the CPU circuit unit 200 via a communication integrated circuit (communication IC) 224 to exchange data, and drives and controls the finishing device 100 by executing various types of programs stored in the ROM 222 based on instructions from the CPU circuit unit 200.

[0044] Furthermore, the control unit 220 of the finishing device drives a conveyance motor M250, the tray lifting motor M251, the wing lowering motor M252, the aligning motor M253, the assist motor M254, the bundle holder motor M255 and the staple-free binding motor M257 via a driver 225.

[0045] Furthermore, the inlet sensor S240, a sheet discharge sensor S246, the bin home position sensor S241 (AP = home position), the bin lower limit sensor S242, the wing home position sensor S243, the support home position sensor S244, and the bundle holder home position sensor S245 are connected to the finishing device control unit 220. Furthermore, the finishing device control unit 220 drives the aligning motor M253, the staple-free binding motor M257, and the like based on detection signals from these respective sensors.

[0046] At the time of performing staple-free binding on the sheets, first, the finishing device control unit 220, which controls an operation of the staple-free binding unit 102, detects the position of the cam 1027 through the cam sensor S247. Then, at the time of receiving the sheets before performing staple-free binding, the finishing device control unit 220 controls rotation of the staple-free binding motor M257 such that the cam 1027 is positioned at a bottom dead center, as shown in Fig. 4A. When the cam 1027 is positioned at the bottom dead center, a space G is created between the upper teeth 10210 and the lower teeth 10214, thereby allowing the plurality of sheets to be subjected to staple-free binding to pass therebetween.

[0047] At the time of executing the binding operation, the control unit 220 of the finishing device rotates the staple-free binding motor M257 so that the upper arm 1029 is pivoted about the axis 10211 in the clockwise direction by the cam 1027. Then, when the cam 1027 reaches a top dead center, as shown in Fig. 4B, the upper teeth 10210 on the upper arm 1029 and the lower teeth 10214 on the lower arm 1012 engage with each other. As a result, the blades are secured together.

[0048] When the cam 1027 is further rotated after the cam 1027 reaches the top dead center, the roller 1028 can pass over the top dead center of the cam 1027 by bending a bending portion 1029a formed on the upper arm 1029. Then, once the roller 1028 has passed over the top dead center of the cam 1027 in this way, the upper arm 1029 is moved in a direction in which the upper teeth 10210 are separated from the lower teeth 10214. Thereafter, when the cam 1027 is further rotated to reach the bottom dead center again, the cam sensor S247 detects the cam 1027. Through this operation, the control unit 220 of the finishing device stops the rotation of the staple-free binding motor M257.

[0049] Next, a sheet binding process of the finishing apparatus 100 according to the present embodiment will be described. As described in the above-described Fig. As shown in Fig. 2A, the sheet P discharged from the image forming apparatus 900 is transferred to the pair of inlet rollers 101 driven by the conveyance motor M250. At this time, the leading edge of the sheet P is detected by the inlet sensor S240.

[0050] Subsequently, the sheet P transferred to the pair of inlet rollers 101 is transferred from the pair of inlet rollers 101 to the sheet discharge roller 103. The leading edge of the sheet P is discharged to the intermediate process tray 107 while static electricity is removed therefrom by the static eliminator 104 at the same time as the sheet is conveyed while the trailing edge dropping member 105 is lifted. The sheet P discharged onto the intermediate process tray 107 by the sheet discharge roller 103 is pressed from above due to the weight of the trailing edge dropping member 105, which can reduce a time required for the trailing edge of the sheet P to fall onto the intermediate process tray 107.

[0051] Subsequently, the control unit 220 of the finishing device controls the interior of the intermediate process compartment 107 based on a signal of the trailing edge of the sheet P detected by the sheet discharge sensor S246. More specifically, as described in the above-described Fig. 2B, the control unit 220 of the finishing device moves the pull-in vane 106 to the intermediate process tray 107 in contact with the sheet P by the vane lifting motor M252. At this time, the pull-in vane 106 is rotated in the counterclockwise direction by the conveying motor M250, whereby the sheet P is moved by the pull-in vane 106 to the trailing edge stopper 108 in the rightward direction in Fig. 2B. Thereafter, the trailing edge of the sheet P is transferred to the knurled belt 117. After the trailing edge of the sheet P is transferred to the knurled belt 117, the finishing device control unit drives the vane lifting motor M252 so that the vane lifting motor M252 moves the retracting vane 106 upward. By detecting that the retracting vane 106 has reached the home position by the vane home position sensor S243, the finishing device control unit 220 stops driving the vane lifting motor M252.

[0052] After conveying the sheet P, which has been conveyed thereto by the pull-in vane 106, to the trailing edge stopper 108, the knurled belt 117 conveys the sheet P while sliding thereon, thereby constantly biasing the sheet P toward the trailing edge stopper 108. This sliding conveyance can bring the sheet P into contact with the trailing edge stopper 108, thereby correcting skew of the sheet P. Subsequently, after the sheet P is brought into contact with the trailing edge stopper 108 in this manner, the control unit 220 of the finisher drives the aligning motor M253 to move the aligning plates 109a and 109b in the width direction perpendicular to the sheet discharge direction, thereby aligning the position of the sheet P in the width direction.The control unit 220 of the finisher repeatedly performs this series of operations on a predetermined number of sheets subjected to the binding process, thereby forming a sheet bundle PA aligned with the intermediate process tray 107 as shown in FIG. Fig. 8A is shown.

[0053] After this alignment process has been performed, the binding unit performs the binding process if a binding mode is selected. After that, as shown in Fig. 8B, the trailing edge of the sheet bundle PA is pushed by the trailing edge assist 112, which is a sheet discharge unit configured to be driven by the assist motor M254, and a discharge claw 113, whereby the sheet bundle PA on the intermediate process tray 107 is discharged to the sheet stacking tray 114 as a bundle.

[0054] Afterwards, as described in Fig. 8C, the bundle holder 115 is rotated counterclockwise to hold the trailing edge of the sheet bundle PA, so that the sheet bundle PA stacked on the sheet stacking tray 114 is prevented from being pushed out in the conveying direction by a subsequently discharged sheet bundle. Then, after completion of the bundle holding operation by this bundle holder 115, when the sheet bundle PA prevents the light from being transmitted to the tray exit point sensor S241, the sheet stacking tray 114 is lowered by the tray lifting motor M251 until the light can be transmitted to the tray exit point sensor S241, thereby determining the sheet surface position. A required number of sheet bundles PA can be discharged onto the sheet stacking tray 114 by repeatedly performing this series of operations.

[0055] When the sheet stacking tray 114 is lowered and begins to prevent light from being transmitted to the tray bottom limit sensor S242 by this operation, the control unit 220 of the finishing device notifies the CPU circuit unit 200 of the image forming device 900 that the sheet stacking tray 114 is full, thereby causing the image forming device 900 to stop image formation. Thereafter, once the sheet bundles on the sheet stacking tray 114 have been removed, the sheet stacking tray 114 is raised until it begins to prevent light from being transmitted to the tray exit point sensor S241, and then it is lowered to allow the light to be transmitted to the tray exit point sensor S241, thereby redetecting the sheet surface on the sheet stacking tray 114. Through this operation, the image forming device 900 resumes image formation.

[0056] The following describes a control of the staple-free binding operation by the control unit 220 of the finishing device during the execution of the staple-free binding with reference to a Fig. 9 is described. When performing staple-free binding on the sheets, first, the control unit 220 of the finishing device drives the staple-free binding motor M257 so that the cam 1027 is moved to the home position (AP) corresponding to the bottom dead center position.

[0057] Then, in step ST1, the control unit 220 of the finishing device detects the position of the cam 1027 by the cam sensor S247 provided in Fig. 7. When the finisher control unit 220 determines that the cam 1027 is not located at the home position (AP) (NO in step ST2), the finisher control unit 220 continues driving the staple-free binding motor M257 in step ST3. Thereafter, when the finisher control unit 220 detects through the cam sensor S247 that the cam 1027 is located at the home position (AP) (YES in step ST2), the finisher control unit 220 stops the staple-free binding motor M257 in step ST4. As a result, the finisher control unit 220 completes realizing a sheet pickup state before executing staple-free binding.

[0058] Subsequently, in step ST5, the control unit 220 of the finishing device determines whether the binding operation is being performed. If the control unit 220 of the finishing device determines that the staple-free binding is being performed (YES in step ST5), in step ST6, the control unit 220 of the finishing device drives the staple-free binding motor M257. When the staple-free binding motor M257 is driven, the upper arm 1029 is pivoted about the axis 10211 in the clockwise direction by the cam 1027. When the cam 1027 is further rotated so that it Fig. 4B, the upper teeth 10210 on the upper arm 1029 and the lower teeth 10214 on the lower arm 1012 engage with each other. As a result, the sheet bundle is secured together. Thereafter, as the cam 1027 is further rotated, the upper arm 1029 pivots about the axis 10211 in the counterclockwise direction, so that the upper teeth 10210 are moved in a direction away from the lower teeth 10214.

[0059] Subsequently, in step ST7, the finishing device control unit 220 detects the position of the cam 1027 through the cam sensor S247. If the finishing device control unit 220 determines that the cam 1027 is not at the home position (AP) (NO in step ST8), in step ST9, the finishing device control unit 220 continues driving the staple-free binding motor M257. Thereafter, if the finishing device control unit 220 determines through the cam sensor S247 that the cam 1027 is at the home position (YES in step ST8), in step ST10, the finishing device control unit 220 stops the staple-free binding motor M257. As a result, the sheet binding process is completed.On the other hand, when the finishing device control unit 220 determines that the binding operation is not being performed (NO in step ST5), the finishing device control unit 220 immediately stops the sheet binding operation.

[0060] Fig. 10 schematically shows the states of the surfaces of the lower teeth 10214 and the upper teeth 10210. The lower teeth 10214 and the upper teeth 10210 have uneven portions (the deformation surfaces for deforming the blades) on their surfaces, which come into contact with the blade bundle, thereby deforming the blade bundle in the thickness direction. In the present embodiment, a surface having shapes of a letter V is formed smoothly on the upper teeth 10210, while a surface having shapes of an inverted letter V is coarsely machined on the lower teeth 10214. In other words, the lower teeth 10214 have a coarser surface than the upper teeth 10210. As a specific machining method suitable therefor, after the upper teeth 10210 and the lower teeth 10214 are formed by a cutting process, a polishing process is performed on only the upper teeth 10210.As a result, cutting marks remain on the lower teeth 10214 to form a rough surface, while a smooth surface can be formed on the upper teeth 10210.

[0061] Then, when the surface of the lower teeth 10214 is rougher than the surface of the upper teeth 10210, the fibers of the attached sheets are placed in a state of adhering to the lower teeth 10214. In other words, according to the present embodiment, the sheets can be intentionally adhered to the lower teeth 10214 by roughening the surface of the lower teeth 10214.

[0062] Furthermore, in the present embodiment, as shown in Fig. 11 and in the above-described Fig. 4A and Fig. As shown in Fig. 4B, a release leaf spring 10215, which is an elastic member, is mounted near the lower teeth 10214 on the lower arm 1012. Then, when the upper arm 1029 is pivoted in the clockwise direction as described above, the release leaf spring 10215 is bent downward by being pressed by the upper arm 1029 over the leaves sandwiched between the upper teeth 10210 and the lower teeth 10214, and is moved to a recessed position where the release leaf spring 10215 does not interfere with gripping the leaves. Furthermore, after the leaf bundles are fastened together, movement of the upper arm 1029 causes the release leaf spring 10215 to be elastically lifted.

[0063] At this time, the detachment leaf spring 10215 elastically protrudes upward beyond the teeth of the lower teeth 10214, that is, in a direction for detaching the leaves beyond the tooth ends of the lower teeth 10214 in the leaf thickness direction. Then, when the detachment leaf spring 10215 is lifted in this way, the detachment leaf spring 10215 pushes the leaves in the direction away from the lower teeth 10214, thereby detaching the leaves from the lower teeth 10214. Therefore, the detachment leaf spring 10215 can prevent the leaves from sticking to the lower teeth 10214.

[0064] It should be noted that the detachment leaf spring 10215 must be arranged within a detachable area where the detachment leaf spring 10215 can detach the leaves, as shown in the Fig. 12A and Fig. 12B, to allow the release leaf spring 10215, which is a release unit, to push and release the leaves in the direction away from the lower teeth 10214. The Fig. 12A and Fig. 12B shows the "detachable area" where the leaves can be detached by the detachment leaf spring 10215, and a "non-detachable area" where the leaves cannot be detached. Furthermore, an end portion of the detachment leaf spring 10215 should be located within the "detachable area" to achieve leaf detachment. Fig. 12A shows the lower teeth 10214 viewed from a longitudinal direction, and Fig. Figure 12B shows the lower teeth 10214 viewed from a direction along a tooth array.

[0065] As this is Fig. As shown in Fig. 12A, when the end portion of the detachment leaf spring 10215 is offset from an origin G in a positive direction z, the detachment leaf spring 10215 can lift the adhered leaves further upward, thereby providing excellent detachment performance. Furthermore, when the end portion of the detachment leaf spring 10215 is offset from the origin G in a positive direction x, the end portion of the detachment leaf spring 10215 is separated farther away from a fixed portion to cause greater deformation of the leaves, thereby deteriorating the detachment performance. Then, a curve L1, which is a boundary line between the "detachable region" and the "non-detachable region," can be obtained from an equation of beam deflection according to material mechanics. The following equation is an equation for calculating a deflection (δ) at one end of a cantilevered beam. δ=WL33EI

[0066] In this equation, δ represents a deflection amount, W represents a load, L represents a beam length, E represents a Young's modulus (E-modulus) and I represents an area moment of inertia.

[0067] Assuming that the origin G is a fixed point and a distance in the x direction corresponds to the beam length, the deflection amount δ is proportional to the cube of the distance. In other words, an increase in the distance in the x direction results in a cube increase in the deflection amount δ of the leaves to be detached. Therefore, the detachment leaf spring 10215 should lift the leaves upward to a large extent in the positive z direction to detach the leaves. This curve L1 also exists at a symmetrical position around the tooth shape, and this curve is expressed as a curve L2.

[0068] Furthermore, as stated in Fig. 12B, the end portion of the detaching leaf spring 10215 must be located within the "detachable range" in a lateral direction of the lower teeth 10214 (the direction along the arrangement of the lower teeth 10214) to enable the detaching leaf spring 10215 to detach the leaves. When the end portion of the detaching leaf spring 10215 is offset from the origin G in the positive direction z, the detaching leaf spring 10215 can further lift the adhered leaves upward, thereby providing excellent detachment performance. Furthermore, when the end portion of the detaching leaf spring 10215 is offset from the origin G in a positive direction y, the end portion of the detaching leaf spring 10215 is further separated from the attached portion to cause greater deformation of the leaves, thereby deteriorating the detachment performance.Then, a curve L3, which is a boundary line between the "detachable region" and the "non-detachable region," can be obtained from the beam deflection equation described above according to material mechanics. Furthermore, this curve L3 also exists at a symmetrical position around the tooth shape, and this curve is expressed as a curve L4.

[0069] The Fig. 13A and Fig. 13B show a positional relationship between the lower teeth 10214 and the release leaf spring 10215 according to the present embodiment. As shown in Fig. 13A, the end portions 102151 of the detachable leaf spring 10215 are arranged within the “detachable area” as shown in Fig. 12A. Furthermore, as shown in Fig. 13B, the end portions 102151 (the detachment unit) of the detachment leaf spring 10215 are also disposed within the "detachable range" in the lateral direction. In the present embodiment, the end portions 102151 of the detachment leaf spring 10215 are disposed at positions offset from a region where the leaves are attached to each other within the "detachable range." As a result, in the present embodiment, the detachment leaf spring 10215 urges the proximal portions outside the region where the leaves are attached to each other in the direction along the tooth arrays of the lower teeth 10214 and the upper teeth 10210.

[0070] Then, when the binding is not carried out, the end portions 102151 of the release leaf spring 10215 are arranged on an upper side relative to an upper position V of the projections of the lower teeth 10214 in the direction z, as shown in Fig. 13B. Therefore, when the upper arm 1029 is moved after the sheets are attached to each other, the end portions 102151 of the detaching leaf spring 10215 are located on the upper side relative to the upper position V of the projections corresponding to the end portions of the lower teeth 10214, and can therefore detach the sheets adhered to the lower teeth 10214.

[0071] Fig. 14A shows the detachment leaf spring 10215, in which the upper teeth 10210 are lowered and the leaf P is fixed to the other leaves. At this time, the fiber of the fixed leaf P is placed in a state of adhesion to the lower teeth 10214. Further, the end portions 102151 of the detachment leaf spring 10215 are pressed by the upper arm 1029 over the leaf P, that is, it is lowered while being released from the position described above. Fig. 13B according to the movement of the upper arm 1029. Thereafter, when the upper arm 1029 is moved upward, elastic forces of the end portions 102151 of the detachment leaf spring 10215 are transmitted to the leaf P, whereby the leaf P is detached from the lower teeth 10214, as shown in Fig. 14B is shown.

[0072] As described above, in the present embodiment, the detaching leaf spring 10215 is provided on the lower arm 1012, and the bound sheets are urged by the detaching leaf spring 10215 in the direction in which the sheets detach from the lower teeth 10214. As a result, even when the sheets are in a state where they are sufficiently attached to each other, the sheet P can be surely detached from the lower teeth 10214 as the first tooth shape. Furthermore, the sheets can be detached without each of the pair of tooth shapes moving relative to the sheets. In other words, as in the present embodiment, the urging of the bound sheets by the detaching leaf spring 10215 can prevent the sheets from remaining stuck to the teeth when the sheets are bound by adopting a small and simple structure.

[0073] In the present embodiment, the release leaf spring 10215 is provided on the lower arm 1012. However, if the upper teeth 10210 have a coarser surface, the release leaf spring 10215 may be provided on the upper arm 1029. In other words, the present embodiment can be realized by providing the release leaf spring 10215 on at least one of the lower arm 1012 and the upper arm 1029, and urging the bound sheets by the release leaf spring 10215 in a direction to release the sheets from at least the upper teeth 10210 and the lower teeth 10214.

[0074] In the present embodiment, the end portions 102151 of the release leaf spring 10215 are arranged at positions offset from the area where the leaves are attached to each other. However, the present invention is not limited to this, and the end portions 102151 of the release leaf spring 10215 may be arranged within the area where the leaves are attached to each other.

[0075] A second embodiment of the present invention will be described below as an example in which the release leaf spring is arranged within the area where the leaves are attached to each other. Fig. 15 shows a structure of a staple-free binding unit mounted on a sheet processing apparatus according to the present embodiment. Fig. 15 are similar or corresponding sections to those described in the above Fig. 11 are shown by the same reference numerals as in Fig. 11.

[0076] With reference to Fig. 15, the staple-free binding unit according to the present embodiment has a release leaf spring 10215A and lower teeth 10214A. Shapes of an inverted letter V are partially removed from the lower teeth 10214A. As shown in Fig. 16A and described below, the V-shapes are partially removed from the upper teeth 10210A at portions corresponding to the portions of the lower teeth 10214A in which the inverted letter V shapes have been removed. Then, end portions 102151A of the release leaf spring 10215A, which is an elastic member, are arranged between the inverted V-shape removed portions 102141A, which are tooth missing portions of the lower teeth 10214A, and the V-shape removed portions 102101A of the upper teeth 10210A. In other words, the end portions 102151A of the separation leaf spring 10215A are respectively disposed between projections (the deformation surfaces) of the lower teeth 10214A on both sides, and a plurality of inverted V shapes (the deformation surfaces) of the lower teeth 10214A are disposed at the center thereof.The end portions 102151A of the release leaf spring 10215A are respectively disposed between V-shapes (the deformation surfaces) of the upper teeth 10210A on both sides and a plurality of V-shapes (the deformation surface) of the upper teeth 10210A at the center thereof.

[0077] Fig. 16A shows the detachment leaf spring 10215A in which the upper teeth 10210A are lowered and the leaf P is attached to the other leaves. At this time, the fiber of the attached leaf P is in a state of adhering to the lower teeth 10214A, and the end portions 102151A of the detachment leaf spring 10215A are lowered while being bent by being pressed over the leaf P by the upper teeth 10210A having the other tooth shape. At this time, the partial removal of the inverted V shapes and the V shapes from the lower teeth 10214A and the upper teeth 10210A allows the end portions 102151A of the detachment leaf spring 10215A to enter the interior of the “detachable area,” as shown in Fig. 16B is shown.

[0078] Thereafter, when the upper arm 1029 is moved upward, the end portions 102151A of the release leaf spring 10215A are arranged on an upper side relative to the upper position V of projections of the lower teeth 10214A in the direction z, as shown in Fig. 16B. As a result, an elastic force (a recovery force) of the detachment leaf spring 10215A is transmitted to the leaf P, and therefore, the leaf P adhering to the lower teeth 10214A can be detached. In this way, a similar effect to that of the above-mentioned first embodiment can be achieved even if the detachment leaf spring is disposed within the region where the leaves are attached to each other, as in the present embodiment.

[0079] A third embodiment of the present invention will be described below as an example in which the release leaf spring is arranged within the areas where the leaves are fixed to each other and at the centers of the upper teeth and the lower teeth. Fig. 17 shows a structure of a staple-free binding unit mounted on a sheet handling apparatus according to the present embodiment. Fig. 17 are those sections which correspond to those in the above-described Fig. 11 are similar or correspond, using the same reference numerals as in Fig. 11.

[0080] With reference to Fig. 17, the staple-free binding unit according to the present embodiment has a release leaf spring 10215B and lower teeth 10214B. Inverted V-shapes are partially removed from the lower teeth 10214B at the center thereof. As shown in the Fig. 18A and Fig. 18B, which will be explained below, V-shapes are partially removed from the upper teeth 10210B at the center thereof. Furthermore, an end portion 102151B of the release plate spring 10215B, which is the elastic member, is disposed between an inverted V-shape removed portion 102141B at the center of the lower teeth 10214B and a V-shape removed portion 102101B at the center of the upper teeth 10210B, which are tooth missing portions. In other words, the lower teeth 10214B have uneven portions (the deformation surfaces for deforming the leaves) on both sides of the portion 102141B where an inverted V-shape is removed, and the end portion 102151B of the release leaf spring 10215B is arranged between the two uneven portions of the lower teeth 10214B.The upper teeth 10210B have uneven portions (the deformation surfaces for deforming the leaves) on both sides of the portion 102101B where the V-shape has been removed, and the end portion 102151B of the release leaf spring 10215B is arranged between the two uneven portions of the upper teeth 10210B.

[0081] Fig. 18A shows the detachment leaf spring 10215B in which the upper teeth 10210B are lowered and the leaf P is attached to the other leaves. At this time, the fiber of the attached leaf P is arranged in a state of adhesion to the lower teeth 10214B, and the end portion 102151B of the detachment leaf spring 10215B is lowered while being bent by being pressed by the upper arm 1029B. At this time, the partial removal of the inverted V-shapes and the V-shapes from the centers of the lower teeth 10214B and the upper teeth 10210B allows the end portion 102151B of the detachment leaf spring 10215B to enter the interior of the “detachable area,” as shown in Fig. 18B is shown.

[0082] Thereafter, when the upper arm 1029 is moved upward, the end portion 102151B of the release leaf spring 10215B is arranged on an upper side relative to the upper position V of projections of the lower teeth 10214B in the direction z, as shown in Fig. 18B. As a result, an elastic force of the detachment leaf spring 10215B is transmitted to the sheet P, and therefore, the sheet P adhering to the lower teeth 10214B can detach. In this way, excellent detachment performance can be achieved by disposing the detachment leaf spring 10215B at a single position at the center as in the present embodiment, compared to disposing the detachment leaf spring 10215B only at a single position at one end.

[0083] The above-described embodiments are described based on the example in which the staple-free binding unit separates the sheets by the separation leaf spring. However, the present invention is not limited to this. For example, the staple-free binding unit may separate the sheets by a vertically movable pressing member configured to be moved by being driven, instead of the separation leaf spring.

[0084] A fourth embodiment of the present invention will be described below as an example in which the staple-free binding unit separates the sheets by the vertically movable pressing member instead of the separation leaf spring. Fig. 19 shows a structure of a staple-free binding unit mounted on a sheet processing apparatus according to the present embodiment. Fig. 19 are sections similar to those in the above-described Fig. 11 are or correspond to them, by the same reference numerals as in Fig. 11.

[0085] With reference to Fig. 19, the staple-free binding unit according to the present embodiment has lower teeth 10214C and a release pin 10215C, which is a pressing member vertically movably disposed, for example, at a center of the lower teeth 10214C. The release pin 10215C is disposed within the area where the sheets are attached to each other by removing inverted V-shapes at the center of the lower teeth 10214C. As shown in Fig. 20, which will be described below, the V-shapes are removed at a center of the upper teeth 10210C. Then, the release pin 10215C is arranged between a portion where an inverted V-shape has been removed at the center of the lower teeth 10214C and a portion where a V-shape has been removed at the center of the upper teeth 10210C.

[0086] Furthermore, as stated in the Fig. 20A and Fig. 20B, an opening 1012a, through which an end portion 10215C of the release pin 10215C projects, is formed at the portion where the inverted V-shape has been removed of the lower teeth 10214C. The release pin 10215C slides vertically through this opening 1012a. This release pin 10215C is moved vertically by a solenoid 10216 disposed below the release pin 10215C. In this way, in the present embodiment, the detachment pin 10215C is arranged to be capable of projecting in a direction for detaching the sheets, and is moved to a recessed position and a position where the detachment pin 10215C projects in the direction for detaching the sheets by the solenoid 10216, which is a driving unit configured to move the detachment pin 10215C by driving it.

[0087] Fig. 20A shows the detachment pin 10215C where the upper teeth 10210C are lowered and the blade P is attached to the other blades. At this time, the fibers of the attached blade P are placed in a state where they adhere to the lower teeth 10214C. At this time, the detachment pin 10215C is lowered by the solenoid 10216 to the position where the detachment pin 10215C does not interfere with the upper teeth 10210C, which are lowered to attach the blades to each other.

[0088] Thereafter, according to an upward movement of the upper arm 1029, the release pin 10215C is lifted by the solenoid 10216 so that its end portion 102151C projects upward relative to the upper position V of the projections of the lower teeth 10214C in the direction z, as shown in Fig. 20B. As a result, the sheet P adhering to the lower teeth 10214C can be detached by the detaching pin 10215C through the application of a pressing force of the solenoid 10216. In the present embodiment, the detaching pin 10215C is arranged at the center of the lower teeth 10214C, but a plurality of detaching pins may be arranged around the lower teeth 10214C or in a "binding area." In this way, a similar effect to that of the above-described first embodiment can be obtained by configuring the staple-free binding unit to detach the sheets using the detaching pin 10215C, as in the present embodiment.

[0089] Alternatively, the staple-free binding unit may be constructed in such a manner that the release pin 10215C is lifted by the solenoid 10216 after the upper arm 1029 has moved upward.

[0090] Furthermore, in the second to fourth embodiments, the release leaf spring 10215A or 10215B or the release pin 10215C is arranged only on the lower teeth. However, the present invention is not limited to this. If the surface property of the tooth shape is similar between the upper teeth and the lower teeth, a similar release effect can be achieved by disposing the release leaf spring 10215A or 10215B or the release pin 10215C on the upper teeth and the lower teeth.

[0091] A fifth embodiment of the present invention will be described below as an example in which the staple-free binding unit has peeling wire springs arranged on the lower teeth and the upper teeth instead of the peeling leaf spring and peels the sheets using these peeling leaf springs. Fig. 21 shows a structure of a staple-free binding unit mounted on a sheet processing apparatus according to the present embodiment. Fig. 21 are those sections similar to those described in the Fig. 11 or corresponding sections are identified by the same reference numerals as in Fig. 11.

[0092] With reference to Fig. 21, the staple-free binding unit according to the present embodiment has lower teeth 10214D and a release wire spring 10215D, which is an elastic body arranged, for example, at the center of the lower teeth 10214D and configured to release the bound sheets by being pushed in a direction away from the lower teeth 10214D. This release wire spring 10215D, which is a first release unit, is arranged within the area where the sheets are attached to each other by removing inverted V shapes at the center of the lower teeth 10214D. As shown in Fig. 22, the release wire spring 10215D is held by a support block 10217, and this support block 10217 is attached to the lower arm 1012 by a fixing screw 10218. Furthermore, as shown in Fig. 23A, a detaching wire spring 10215E, which is a second detaching unit configured to detach the bound sheets by urging them in a direction away from the upper teeth 10210D, is also arranged at, for example, a center of the upper teeth 10210D by removing their V-shapes and adopting a similar configuration to that of the lower teeth 10214D.

[0093] In the present embodiment, the lower teeth 10214D and the upper teeth 10210D are formed by similar machining processes, and therefore, there is no difference between their surface properties. Therefore, if there is no difference between the surface properties of the lower teeth 10214D and the upper teeth 10210D, the fibers of the bonded sheets are adhered to at least one of the lower teeth 10214D and the upper teeth 10210D.

[0094] In the present embodiment, the “binding area” where the staple-free binding unit fastens the sheets together corresponds to an area indicated by a dashed line in Fig. 23A, and the partial removal of the inverted V-shapes and the V-shapes allows the peeling wire springs 10215D and 10215E to enter the interior of the "peelable area." The peeling wire spring 10215D is smaller than the peeling leaf spring and the peeling pin, and therefore can reduce the amount by which the V-shapes and the inverted V-shapes of the upper teeth 10210D and the lower teeth 10214D need to be removed. As a result, even with the same "binding area," the present embodiment can increase the inverted V-shapes and the V-shapes within the area, thereby improving the fastening force.

[0095] When the binding is not performed, an end portion 102151D of the release wire spring 10215D is arranged on an upper side relative to the upper position V on projections of the lower teeth 10214D in the direction z, as shown in Fig. 23B. Furthermore, an end portion 102151E of the release wire spring 10215E is arranged on the upper side relative to at least the upper position V of the projections of the lower teeth 10214D in the direction z.

[0096] Fig. 23A shows the release leaf springs 10215D and 10215E, in which the upper teeth 10210D are lowered and the leaf P is attached to the other leaves. At this time, the fibers of the attached leaf P adhere to at least one of the lower teeth 10214D and the upper teeth 10210D. Furthermore, the end portion 102151D of the release wire spring 10215D and the end portion 102151E of the release wire spring 10215E are made of the material shown in Fig. 23B into a bent state by being pressed over the sheet P.

[0097] Thereafter, when the upper arm 1029 is moved upward, an elastic force of the end portion 102151D of the detaching wire spring 10215D is transmitted to the sheet P, whereby the sheet P is detached from the lower teeth 10214D, as shown in Fig. 23B. Furthermore, an elastic force of the end portion 10215E of the peeling wire spring 10215E is transmitted to the sheet P, thereby peeling the sheet P from the upper teeth 10210D. In this way, a similar effect to the above-described first embodiment can be achieved, and a reduction in the size of the apparatus can be realized by configuring the staple-free binding unit to peel the sheets using the peeling wire springs 10215D and 10215E, as in the present embodiment.

[0098] In the present embodiment, the detachment wire spring 10215D and the detachment wire spring 10215E are arranged at the centers of the lower teeth 10214D and the upper teeth 10210D, respectively, but their positions are not limited to this example. Furthermore, by arranging a plurality of detachment wire springs in a configurable manner, the pressing force for detaching the sheets can be increased. Furthermore, the upper teeth 10210D and the lower teeth 10214D may be formed to have different surface properties from each other, similarly to the first to fourth embodiments described above, and the detachment wire spring may be arranged only on one of the tooth shapes having a coarser surface.Furthermore, when the surface property of the tooth shape between the upper teeth 10210D and the lower teeth 10214D is similar in the present embodiment, a similar peeling effect can be obtained by disposing the peeling leaf spring 10215, 10215A or 10215B or the peeling pin 10215C on the upper and lower teeth.

[0099] As this is Fig. 24, the staple-free binding unit may be constructed such that the sheet bundle is released from the lower teeth by the application of a lever 31 constructed to be raised and lowered in accordance with a movement of the cam 1027. Referring to Fig.24, the lever 31 is rotatably mounted about an axis 32 and is biased into engagement with the bottom of the cam 1027 by a spring 33. An end portion 10214F of the lever 31 can project upward relative to the end portions of the lower teeth 10210F. When the cam 1027 is positioned at a position where the cam 1027 causes the lower teeth 10210F and the upper teeth 10210F to engage with each other, the end portion 10214F of the lever 31 is retracted to a lower position relative to the teeth of the lower teeth 10210F. Pivoting movement of the lever 31 in accordance with the rotation of the cam 1027 causes the end portion 10214F of the lever 31 to project beyond the lower teeth 10210F. The lever 31 is arranged in such a manner that the end portion 10214F of the lever 31 is located within the detachable area when it projects.In other words, when the upper teeth 10210F and the lower teeth 10210F are separated from each other by the rotation of the cam 1027, the end portion 10214F detaches the sheet bundle adhering to the lower teeth 10210F. In the present embodiment, the staple-free binding motor M257 and the cam 107, which constitute the moving unit configured to move the upper teeth 10210F, also correspond to the driving unit configured to drive the lever 31 as the detaching unit.

[0100] All of the above-described embodiments are described based on an example in which the lower teeth are fixed and only the upper teeth are moved by the moving unit 102A. However, the respective embodiments may be configured such that the upper teeth are fixed and only the lower teeth are moved by the moving unit. Alternatively, the respective embodiments may be configured such that both the upper teeth and the lower teeth are movable, and the moving unit moves them into contact with each other and away from each other.

[0101] While the present invention has been described with reference to the embodiments, it should be understood that the invention is not limited to the disclosed embodiments.

[0102] The sheet processing apparatus includes a binding unit having a first portion and a second portion and configured to clamp a sheet bundle between the first portion and the second portion to deform the sheet bundle in a thickness direction to bind the sheet bundle, and a detaching unit configured to press the bound sheet bundle toward the second portion to detach the bound sheet bundle from the first portion.

Claims

[1] Sheet processing device with: a binding unit (102) which a first section (1012) with a plurality of first teeth (10214) and a second portion (1029) having a plurality of second teeth (10210) opposite the first teeth (10214), wherein the binding unit (102) is configured to bind a sheet bundle by clamping the sheet bundle in a thickness direction between the first teeth (10214) and the second teeth (10210); and a detaching unit (10215, 10215A, 10215B, 10215C, 10215D, 10215E) configured to urge the bound sheet bundle toward the second section (1029) so that the bound sheet bundle is detached from the first section (1012). [2] A sheet processing apparatus according to claim 1, wherein the detaching unit (10215) is configured to detach the bound sheet bundle from the first portion (1012) when the first portion (1012) and the second portion (1029) move away from each other so as to be free from clamping the sheet bundle. [3] A sheet processing apparatus according to claim 1, wherein the detaching unit (10215) is movable to project toward the second portion (1029) beyond an end portion (102151) of the first portion (1012) in the thickness direction of the sheet bundle when the first portion (1012) and the second portion (1029) are separated from each other. [4] Sheet processing device according to claim 1, wherein the detaching unit (10215) comprises an elastic member (10251) which is elastically deformable by being pressed by the sheet bundle being bound, and wherein the detaching unit (10215) is constructed such that the sheet bundle is detached from the first portion (1012) with the aid of a restoring force of the elastic member (10251) when the first portion (1012) and the second portion (1029) are separated from each other. [5] A sheet processing device according to claim 4, wherein the elastic member (10251) is a leaf spring. [6] A sheet processing device according to claim 4, wherein the elastic member is a wire spring. [7] A sheet processing device according to claim 1, wherein the first teeth (10214) of the first section (1012) are coarsely formed compared to the second teeth (10210) of the second section (1029). [8] A sheet processing device according to claim 1, wherein the detaching unit (10215) is arranged outside the first teeth (10214) of the first portion (1012). [9] A sheet processing apparatus according to claim 8, wherein the peeling unit (10215) has a plurality of peeling portions (102151) that come into contact with the sheet bundle, and wherein the first teeth (10214) are arranged between the plurality of peeling portions (102151). [10] Sheet processing device according to claim 1, wherein the first teeth (10214) have a first region of first teeth (10214) and at least a second region of first teeth (10214) separated from each other by a tooth missing portion, and wherein the detachment unit (10215) is arranged between the first region of the first teeth (10214) and the second region of the first teeth (10214). [11] Sheet processing device according to claim 1, wherein the first teeth (10214) are constructed as a plurality of teeth so as to deform the sheet bundle in the thickness direction, and wherein the detachment unit (10215) is disposed at a location on the first portion (1012) that is different from the plurality of teeth. [12] Sheet processing device with: a binding unit (102) having a first portion (1012) and a second portion (1029) and configured to clamp a sheet bundle between the first portion (1012) and the second portion (1029) to deform the sheet bundle in a thickness direction to thereby bind the sheet bundle; and a first detaching unit (10215D) configured to urge the bound sheet bundle toward the second section (1029) so that the bound sheet bundle is detached from the first section (1012); and a second detaching unit (10215E) configured to urge the sheet bundle toward the first section (1012) so that the bound sheet bundle is detached from the second section (1029). [13] A sheet processing apparatus according to claim 1, further comprising a drive unit (10216) configured to move the detaching unit (10215) by driving the detaching unit (10215) from a position where the first portion (1012) and the second portion (1029) clamp the sheet bundle between them to a position where the first portion (1012) and the second portion (1029) are separated and the detaching unit (10215) projects toward the second portion (1029). [14] A sheet processing apparatus according to claim 1, further comprising a moving unit (M257, 107) configured to move either the first portion (1012) or the second portion (1029) between a position where the first portion (1012) and the second portion (1029) clamp the sheet bundle between them and a release position where the first portion (1012) and the second portion (1029) are separated from each other to be released from clamping the sheet bundle. [15] Sheet processing device according to claim 12, wherein each of the first portion (1012) and the second portion (1029) has an uneven portion configured to deform the sheet bundle in the thickness direction by coming into contact with the sheet bundle, and wherein the first separation unit (10215D) is movable to protrude beyond an end portion of the uneven portion of the first portion (1012) in the thickness direction of the sheet bundle when the first portion (1012) and the second portion (1029) are separated from each other. [16] Sheet processing device according to claim 12, wherein the first detaching unit (10215D) has a plurality of detaching portions (102151) that come into contact with the sheet to detach the sheet from the one of the first portion (1012) and the second portion (1029), wherein each of the first portion (1012) and the second portion (1029) has a deformation surface configured to deform the sheet bundle in the thickness direction by coming into contact with the sheet bundle, and wherein the deformation surface of the first portion (1012) is arranged between the plurality of detachment portions (102151). [17] Sheet processing device according to claim 12, wherein each of the first portion (1012) and the second portion (1029) has a plurality of deformation surfaces configured to deform the sheet bundle in the thickness direction by coming into contact with the sheet bundle, and wherein the first detaching unit (10215D) is arranged between the plurality of deformation surfaces. [18] Image forming device comprising: an image forming unit (900B) configured to form an image on a sheet; and the image processing device according to claim 1. [19] A sheet processing apparatus according to claim 1, further comprising a second detaching unit (10215E) configured to urge the sheet bundle toward the first portion (1012) so that the bound sheet bundle is detachable from the second teeth (10210). [20] Sheet processing device according to claim 12, wherein the first portion (1012) has a plurality of first teeth (10214), and the second section (1029) has a plurality of second teeth (10210) opposite the teeth of the first section (1012), wherein the binding unit (102) binds the sheet bundle by clamping the sheet bundle with the first teeth (10214) and the second teeth (10210). [21] A sheet processing device according to claim 1, wherein the detaching unit (10215) has a first edge, a second edge, and a third edge when viewed in the thickness direction of the bound sheet bundle, the first edge, the second edge, and the third edge surrounding the first teeth (10214) and opposing the first teeth (10214), the second edge and the third edge being connected to the first edge and perpendicular to the first edge, the first edge extending in a first direction (y), the second edge and the third edge extending in a second direction (x), and the second edge and the third edge being parallel to each other, wherein a force which the detaching unit (10215) applies to the sheet bundle to detach the sheet bundle from the first portion (1012) has a component along a third direction (z), wherein the second edge and the third edge are arranged on the same side with respect to the first edge in the second direction (x), and where the second direction (x) is perpendicular to the first direction (y) and perpendicular to the third direction (z). [22] A sheet processing apparatus according to claim 21, wherein the detaching unit (10215) has a flat surface and is constructed such that, by bringing the flat surface into contact with the bound sheet bundle, the bound sheet bundle is urged toward the second portion (1029) in such a manner that the bound sheet bundle is detachable from at least one of the first teeth (10214) when the first teeth (10214) and the second teeth (10210) move away from each other to release the sheet bundle from being clamped. [23] A sheet processing apparatus according to claim 21 or 22, wherein the detaching unit (10215) is a detaching leaf spring member provided on the first portion (1021). [24] A sheet processing device according to claim 1, wherein the detaching unit (10215) comprises a main body and two detaching sections (102151), the two detaching sections (102151) extending from an edge of the main body of the detaching unit (10215) located on the side of the teeth (10214, 10210) orthogonally in the direction extending from the main body toward the teeth (10214, 10210). [25] A sheet processing device according to claim 24, wherein the two detaching portions (102151) have an outer edge extending continuously to an outer edge of the main body of the detaching unit (10215) and an inner edge extending perpendicular to the edge of the main body of the detaching unit (10215) located on the side of the teeth (10214, 10210). [26] A sheet processing apparatus according to claim 1, wherein the peeling unit (10215) is provided at the first portion (1012). [27] A sheet processing apparatus according to claim 1, wherein the detaching unit (10215) is configured to move so as to urge the bound sheet bundle so that the bound sheet bundle is detached from at least one of the first teeth (10214) when the first teeth (10214) and the second teeth (10210) move away from each other to release the sheet bundle from being clamped.

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