JP3825846B2 - Sheet processing apparatus and image forming apparatus - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sheet processing apparatus. Specifically, for example, sheets such as copy sheets discharged after image formation from an image forming apparatus such as a copying machine, a printing machine, and a laser beam printer are sequentially taken into the apparatus. And a sheet processing apparatus that performs processing such as binding, folding, and folding near the center of the sheet, and discharging and stacking on a stacking unit.
[0002]
[Prior art]
As shown in FIG. 16, the conventional sheet processing apparatus 300 includes conveying rollers 301 and 302, a sheet stopper 303, a sheet aligning unit 304, a sheet binding device 305, an ejection plate 306, folding rollers 307 and 308, discharge rollers 309 and 310. , And a stacking tray 311.
[0003]
In the conventional sheet processing apparatus 300, a sheet discharged from an image forming apparatus (not shown) is conveyed into the sheet processing apparatus 300. First, the sheet is nipped and conveyed by the conveying roller 301, and passed to the conveying roller 302 through the vicinity of the sheet binding device 305. Further, the sheet is conveyed until the leading end reaches the sheet stopper 303 waiting at the first stacking position, and the end portion is aligned by the sheet aligning means 304 and aligned. This similar operation is repeated for a plurality of sheets, and a plurality of sheets are stacked at the first stacking position. The stacked sheets are bound and bound by the sheet binding device 305. Thereafter, the sheet stopper 303 moves to a second stacking position (position shown in FIG. 16) that is above the first stacking position. Therefore, the bundled sheet bundle is pushed by the ejecting plate 306 to enter the folding rollers 307 and 308, is folded in half, and is discharged onto the stacking tray 311 by the discharge rollers 309 and 310. At this time, the discharge roller 309 is formed by four rollers 309a, 309b, 309c, and 309d having the same size as shown in FIG. A large-sized sheet bundle, which is considered to be weak, is also conveyed in the same manner.
[0004]
[Problems to be solved by the invention]
However, in the above conventional example, when a sheet bundle having weak stiffness is conveyed, the leading end of the sheet bundle is turned down immediately after passing through the discharge rollers 309 and 310, and is dropped as it is. There was a risk that the robot would collide at an angle close to a right angle and could not be loaded correctly on the stacking tray 311.
[0005]
Therefore, when discharging the sheet bundle onto the stacking tray 311, the sheet bundle is curved in the width direction perpendicular to the conveying direction regardless of the size and stiffness of the sheet bundle, so-called vertical stiffness is applied. It is conceivable to carry it. However, some sheet bundles having a small width and strong stiffness are easy to bend in the vertical direction (a direction parallel to the conveying direction), and there is a possibility that the sheet will be folded in the vertical direction when attempting to attach a vertical stiffness.
[0006]
In addition, when a sheet bundle having a vertical crease is discharged onto the stacking tray 311, the folds folded by the folding rollers 307 and 308 are opened immediately, and may not be stacked correctly on the stacking tray 311. there were.
[0007]
SUMMARY OF THE INVENTION An object of the present invention is to make sure that a sheet bundle is always discharged and stacked on a stacking tray in a correct state regardless of the size and stiffness.
[0008]
[Means for Solving the Problems]
  In order to achieve the above object, a typical configuration of the present invention includes a first sheet stacking unit capable of stacking a plurality of sheets, and a first sheet transporting unit that transports sheets to the first sheet stacking unit. An aligning unit that aligns the sheets stacked on the first sheet stacking unit, a sheet binding unit that binds a plurality of aligned sheets to a substantially central portion in the transport direction by the first sheet transport unit, and a binding Sheet bundle folding means for folding the stopped sheet bundle in half at the binding position, a second sheet stacking section for stacking the folded sheet bundle, and a sheet bundle folded in half in the second sheet stacking section In the sheet processing apparatus having the second sheet conveying unit that conveys the sheet bundle, when the sheet bundle is conveyed to the second sheet stacking unit, the length in the width direction orthogonal to the conveyance direction of the sheet bundle is greater than a predetermined length. If short It conveyed while transports without bending the sheet bundle is curved sheet bundle in the width direction when the length in the width direction of the sheet bundle is longer than a predetermined lengthThe second sheet conveying means includes a first conveying roller and a second conveying roller having different outer diameters, and a sheet bundle whose width in the width direction is shorter than a predetermined length is nipped and conveyed by the first conveying roller. The sheet bundle having a length in the width direction longer than a predetermined length is nipped and conveyed by the first conveying roller, so that the vicinity of the width direction end of the sheet bundle is higher or lower than the nipping position of the first conveying roller. And the friction coefficient of the member forming the second conveyance roller is smaller than the friction coefficient of the member forming the first conveyance roller.It is characterized by that.
[0009]
  According to the above configuration, when the sheet bundle is conveyed to the second sheet stacking unit, if the length in the width direction of the sheet bundle is longer than a predetermined length, the sheet bundle is curved in the width direction, so-called vertical stiffness is applied. Therefore, the leading edge of the sheet bundle does not hang down in the vertical direction with respect to the second sheet stacking portion during the transport, so that stacking failure does not occur. On the other hand, when the length in the width direction of the sheet bundle is shorter than a predetermined length, the sheet bundle is conveyed without being curved and without so-called vertical stiffness. Can be prevented. Therefore, the sheet bundle conveyed to the second sheet stacking unit is always conveyed and stacked in the correct state regardless of the size and stiffness.Further, the coefficient of friction of the member forming the second conveying roller is smaller than the coefficient of friction of the member forming the first conveying roller, and the sheet bundle is sandwiched by the first conveying roller. However, when the sheet is conveyed, a roller mark caused by sliding of the sheet bundle is prevented.
[0010]
DETAILED DESCRIPTION OF THE INVENTION
Next, an embodiment of a sheet processing apparatus to which the present invention is applied will be specifically described with reference to the drawings. FIG. 15 is a longitudinal front view showing an example of an image forming apparatus including the sheet processing apparatus according to the present embodiment.
[0011]
In the following description, the schematic configuration of the image forming apparatus (in this embodiment, a copying machine is illustrated) will be described first, and then the sheet processing apparatus according to this embodiment will be described in detail.
[0012]
{Schematic configuration of image forming apparatus}
First, a schematic configuration of the image forming apparatus will be briefly described with reference to FIG. As shown in FIG. 15, the image forming apparatus main body 900 includes a platen glass 906 as a document placement table, a light source 907, a lens system 908, a paper feeding unit 909, an image forming unit 902, and the like.
[0013]
The sheet feeding unit 909 includes cassettes 910 and 911 that store recording sheets S and are detachable from the apparatus main body 900, and a deck 913 disposed on the pedestal 912. The image forming unit 902 includes a cylindrical photosensitive drum 914 and a developing device 915 around it, a transfer charger 916, a separation charger 917, a cleaner 918, a primary charger 919, and the like. On the downstream side of the image forming unit 902, a conveying device 920, a fixing device 904, a discharge roller pair 905, and the like are disposed.
[0014]
Next, the operation of the image forming apparatus main body 900 will be described. When a paper feed signal is output from the control device 150 provided on the apparatus main body 900 side, the sheet S is fed from the cassettes 910 and 911 or the deck 913. On the other hand, the light reflected from the light source 907 on the original D placed on the platen glass 906 as the original placement table is irradiated onto the photosensitive drum 914 via the lens system 908. The photosensitive drum 914 is charged in advance by a primary charger 919, and an electrostatic latent image is formed by irradiation with light, and then the electrostatic latent image is developed by a developing device 915 to form a toner image. The
[0015]
The sheet S fed from the sheet feeding unit 909 is corrected for skew by the registration roller 901, and further sent to the image forming unit 902 at a proper timing. In the image forming unit 902, the toner image on the photosensitive drum 914 is transferred to the sheet S sent by the transfer charger 916. The sheet S to which the toner image has been transferred is charged by the separation charger 917 to have a polarity opposite to that of the transfer charger 916 and separated from the photosensitive drum 914.
[0016]
The separated sheet S is conveyed to the fixing device 904 by the conveying device 920, and the transfer image (toner image) is permanently fixed on the sheet S by the fixing device 904. The sheet S on which the image is fixed is discharged from the apparatus main body 900 by a discharge roller pair 905.
[0017]
In this way, the sheet S fed from the sheet feeding unit 909 is ejected from the image forming apparatus main body 900 after an image is formed, and is carried into a sheet processing apparatus 2 described later.
[0018]
{Configuration of sheet processing apparatus}
Next, the sheet processing apparatus according to the present embodiment will be described in detail. FIG. 1 is a longitudinal side view of a sheet processing apparatus according to the present embodiment. In FIG. 1, reference numeral 900 denotes the image forming apparatus main body described above. In this embodiment, a copying machine is exemplified as the image forming apparatus. However, the image forming apparatus is not limited to this, and may be another image forming apparatus such as a printer or a printing apparatus.
[0019]
Reference numeral 905 denotes a discharge roller pair, which includes a discharge roller 905a and a discharge roller 905b pressed against the discharge roller 905a. Reference numeral 2 denotes a sheet processing apparatus to which the present invention is applied.
[0020]
Reference numeral 3 denotes an inlet flapper. The inlet flapper 3 is engaged with an inlet solenoid 3d (see FIG. 3), and the bookbinding mode / stack mode is switched by turning on and off the power of the inlet solenoid 3d.
[0021]
(Stack mode configuration)
Reference numeral 4 denotes a paper discharge guide. A stacker discharge roller 5 and a stacker discharge roller 6 are disposed downstream of the sheet discharge guide 4. Reference numeral 7 denotes a stacker tray on which the sheets discharged from the stacker discharge roller 5 are stacked.
[0022]
When the stack mode is selected in the sheet processing, an image is formed by the image forming apparatus 900, and the discharged sheet is guided to the discharge guide 4 by the entrance flapper 3, and is stacked by the stack discharge roller 5 and the stack discharge roller 6. It is discharged onto the tray 7 and loaded.
[0023]
(Binding mode configuration)
11 and 12 are guides. Reference numeral 13 denotes a conveyance roller, and a conveyance roller 14 is disposed on the opposite surface. The transport roller 14 is pressed by the transport roller 13.
[0024]
15 is above the switching flapper and 16 is below the switching flapper. On the switching flapper, the lower 15 and 16 are engaged with the switching solenoid and the lower 15d and 16d (see FIG. 3). When the electrical signal is turned ON and OFF, the one-dot chain line and the solid line shown in FIG. It is configured to take two positions.
[0025]
Reference numerals 17a and 22a denote conveying rollers, and elastic members 17d and 22d for bringing the sheet into contact with the conveying rollers 17a and 22a are disposed on the opposing surfaces, and are urged by the conveying rollers 17a and 22a. The conveying rollers 17a and 22a receive the sheet sent by the conveying roller 13 and further convey it.
[0026]
A first sheet conveying means for conveying the sheet is constituted by the conveying roller 13, the conveying roller 14, and the conveying rollers 17a and 22a.
[0027]
When the leading edge of the sheet conveyed by the first sheet conveying means reaches the leading edge stopper 23 as the first sheet stacking means, the sensor 33 detects that the leading edge of the sheet has reached the leading edge stopper 23, and the first The sheet conveying means stops.
[0028]
Reference numeral 18 denotes a stapler unit, which will be described later, and is a sheet binding unit that staples a sheet bundle. Reference numerals 20 and 21 denote guides arranged on the downstream side of the stapler unit 18.
[0029]
Reference numerals 24a and 24b denote width adjusting members, which are alignment means for pressing and aligning the sheet from both sides. Reference numeral 23 denotes the above-described leading end stopper, which is a first sheet stacking unit that receives the leading end of the sheet that has entered between the guides 20 and 21. The tip stopper 23 is configured to be movable between the guides 20 and 21 in the direction of the arrow in the figure. The front end stopper 23 has two purposes, one is positioning when the sheet is stapled by the stapler unit 18 and the other is folding positioning described later. On the leading edge stopper 23, a leading edge stopper sensor 33 for detecting the above-described sheet leading edge is disposed.
[0030]
Reference numeral 25 denotes a protruding unit, which is retracted to the lower surface from the guides 12 and 21 before folding. Reference numerals 26 and 27 denote folding rollers as sheet bundle folding means, which are pressed against each other. Reference numeral 28 denotes a discharge guide for guiding a sheet bundle conveyed while being folded by the folding rollers 26 and 27 between nips of a discharge roller 30 and a discharge roller 31 as second sheet conveying means.
[0031]
A discharge sensor 29 detects the leading end and the trailing end of the sheet bundle conveyed while being folded by the folding rollers 26 and 27. Reference numeral 32 denotes a stacking tray as a second sheet stacking unit, which stacks and holds the sheet bundle discharged by the discharge roller 30 and the discharge roller 31 on a substantially horizontal stacking surface.
[0032]
Here, the second sheet conveying means will be described in detail with reference to FIG. The discharge roller 30 is composed of four rollers 30a, 30b, 30c and 30d arranged on the same axis. Among these four rollers, the rollers 30b and 30c as the first conveying rollers disposed in the vicinity of the center in the longitudinal direction of the shaft (the width direction orthogonal to the conveying direction) have the same outer diameter, and in the vicinity of the end in the longitudinal direction. The disposed rollers 30a and 30d as the second conveying rollers have the same outer diameter, and the outer diameters of the rollers 30a and 30d are larger than the outer diameters of the rollers 30b and 30c. Further, the discharge roller 31 faces only the rollers 30b and 30c. The interval between the rollers 30a and 30d is wider than a predetermined width X, and a sheet bundle having a width smaller than the predetermined width X is nipped and conveyed only by the rollers 30b and 30c and the discharge roller 31 (FIG. 2 (b)). On the other hand, a sheet bundle having a width larger than the predetermined width X is conveyed by the rollers 30a and 30d while being nipped and conveyed by the rollers 30b and 30c and the discharge roller 31 (see FIG. 2A). At this time, since the rollers 30a and 30d near both ends have larger outer diameters than the rollers 30b and 30c near the center, the sheet bundle is conveyed with so-called vertical stiffness with both ends lifted and curved. .
[0033]
As described above, according to the above configuration, when the sheet bundle is conveyed to the stacking tray 32, if the length in the width direction of the sheet bundle is longer than the predetermined length X, the sheet bundle is curved in the width direction. Since the sheet bundle is conveyed with a so-called vertical stiffness, the leading edge of the sheet bundle does not hang down in the vertical direction with respect to the stacking tray 32 in the middle of the conveyance and does not cause a stacking failure. On the other hand, when the length of the sheet bundle in the width direction is shorter than the predetermined length X, the sheet bundle is conveyed without being curved and without so-called vertical stiffness. Breaking can be prevented. Therefore, the sheet bundle conveyed to the stacking tray 32 is always conveyed and stacked in a correct state regardless of the size and stiffness.
[0034]
Further, the coefficient of friction of the members forming the rollers 30a and 30d as the second conveying rollers is smaller than the coefficient of friction of the members forming the rollers 30b and 30c as the first conveying rollers. When the sheet bundle is conveyed while being sandwiched between the rollers 30b and 30c and the discharge roller 31, no roller marks are generated due to slipping of the sheet bundle.
[0035]
Next, the drive mechanism of the inlet flapper 3, the switching flappers 15, 16, and the transport rollers 13, 17a, 22a will be described with reference to FIG.
[0036]
(Inlet flapper drive mechanism)
The inlet flapper 3 is configured to be swingable about a central axis 3a. A link 3b is fixed to one end of the central shaft 3a. A spring 3c is engaged with the link 3b and urges the inlet flapper 3 in one direction. Reference numeral 3d denotes an inlet solenoid which is engaged with one end of the link 3b. When the power supply of the inlet solenoid 3d is turned on, the iron core is sucked and the inlet flapper 3 jumps up (to the one-dot chain line position in FIG. 3) and switches to the bookbinding mode. When the power is turned off, the stack mode is set. That is, the inlet flapper 3 is in the lower part (the position indicated by the solid line in FIG. 3) by the urging force of the spring 3 c and guides the sheet bundle in the direction of the guide 4.
[0037]
(Conveyance roller drive mechanism)
Conveying roller pulleys 13b, 17c and 22c are fixed on the central shafts 13a, 17b and 22b of the conveying rollers 13, 17a and 22a, respectively. In addition, elastic members 17d and 22d for pressing the sheet against the conveying rollers 17a and 22a are arranged at positions opposed to the conveying rollers 17a and 22a, respectively (see FIG. 1).
[0038]
51 is a transport motor, and a transport motor pulley 52 is fixed to the output shaft thereof. A timing belt 53 is wound around the outer periphery of the transport motor pulley 52 and the transport roller pulleys 13b and 17c, and a timing belt 54 is wound between the transport roller pulleys 17c and 22c. Accordingly, the rotation of the conveyance motor 51 is transmitted from the conveyance motor pulley 52 to the timing belt 53, rotates the conveyance roller pulleys 13b and 17c, and further rotates the conveyance roller pulley 22c via the timing belt 54. As a result, the transport rollers 13, 17a and 22a rotate. At this time, since the conveyance roller pulleys 17c and 22c rotate in synchronization, the conveyance rollers 17a and 22a also rotate in synchronization.
[0039]
(Switching flapper drive mechanism)
Flapper links 15b and 16b are fixed on the rotation center shafts 15a and 16a of the switching flappers 15 and 16, respectively. One ends of the flapper links 15b and 16b are engaged with switching solenoids 15d and 16d, respectively. Further, springs 15c and 16c are engaged with the other ends of the flapper links 15b and 16b, respectively, and the switching flappers 15 and 16 are held at the illustrated positions. When the power of the switching flappers 15 and 16 is turned on, the switching solenoids 15d and 16d attract the iron core, and the switching flappers 15 and 16 are held at the position of the one-dot chain line in FIG.
[0040]
The switching flappers 15 and 16 are switched according to the sheet size processed by the sheet processing apparatus so that the stacking order of the sheet bundles stacked / aligned in the apparatus is always constant, that is, afterwards The stacked sheets always overlap with the upper left of the sheet bundle.
[0041]
(Width adjustment mechanism)
Next, the width adjusting mechanism as the aligning means will be described with reference to FIG. In FIG. 4, reference numerals 24a and 24b denote width-adjusting members disposed at both ends in the width direction (front and rear in FIG. 1) orthogonal to the conveying direction, and are wall surfaces that are parallel to the conveying direction of the sheet bundle and perpendicular to both sides of the sheet bundle. And a rack gear is formed near the center. A pinion gear 24c is engaged with each other's rack gear. Reference numeral 24d denotes a width adjusting motor, and a pinion gear 24c is fixed on its output shaft. The width adjusting motor 24d is a stepping motor. Reference numeral 24e denotes a width-shifting home sensor, which is composed of a photo interrupter. The width adjusting home sensor 24e is arranged at a position for detecting a flag formed in a part of the width adjusting member 24a when the width adjusting members 24a and 24b are retracted by a predetermined amount outside the maximum sheet width that can be aligned. Yes.
[0042]
The width adjusting members 24a and 24b are driven by the driving force of the width adjusting motor 24d being transmitted through the pinion gear 24c and the rack gear, and align the sheets carried into the stopper 23.
[0043]
(Stopper drive mechanism)
Next, the driving mechanism of the stopper 23 will be described with reference to FIGS. In the figure, reference numeral 23 denotes a stopper which receives the leading edge of the sheet that has entered between the guides 20 and 21. A roller 23a is rotatably attached to the stopper 23, and slides in a groove formed in the frame 8. Rack gears 23e are formed at both ends of the stopper 23. Each rack gear 23e is engaged with a pinion gear 23b. A shaft 23c is provided at the center of the pinion gear 23b, and transmits drive to the pinion gear 23b. A stopper gear 23d is fixed to one end of the shaft 23c.
[0044]
Reference numeral 61 denotes a stopper motor, which is a stepping motor. A gear 62 is fixed on the output shaft of the stopper motor 61, and the gear 62 meshes with the stopper gear 23d. Further, a flag is formed on a part of the stopper 23, and the stopper home sensor 63 detects when the home position is reached.
[0045]
A stopper sensor 33 detects the presence or absence of a sheet bundle at the tip of the stopper portion.
[0046]
(Stapler drive mechanism)
Next, a mechanism of a stapler unit as a sheet binding unit for binding sheets together will be described with reference to FIGS.
[0047]
The stapler unit (hereinafter also referred to as “stapler”) 18 is disposed at a symmetrical position with respect to the center of the sheet bundle aligned by the width adjusting members 24 a and 24 b by the support plate 99 fixed to the frame 8.
[0048]
In FIG. 12, a stapler 18 includes a needle driving portion (hereinafter referred to as a forming portion) 101 as an upper needle driving means supported so as to be swingable about a rotating shaft 18a, a drive unit 100, and an anvil portion (bending portion). ) It consists of 19 and.
[0049]
A paper path portion for guiding the sheet bundle is formed below the stapler 18 by the guide members 102 and 111 and the anvil portion 19. The paper path portion is configured such that the guide surface 102a of the guide member 102 that guides the sheet bundle and the binding surface 103 of the anvil portion 19 that staples the guided sheet bundle have an angle γ. Yes. Further, a notch hole 111a having a size that does not interfere with the forming portion 101 of the stapler 18 is notched in the upper guide member 111 that forms the paper path portion having the angle γ.
[0050]
A needle cartridge 104 is detachably attached to the forming unit 101, and about 5000 binding needles 105 connected in a plate shape are loaded in the needle cartridge 104. The plate-like binding needle 105 loaded in the needle cartridge 104 is urged downward by a spring 106 provided on the uppermost side of the needle cartridge 104, and a conveying force is applied to the feeding roller 107 disposed on the lowermost side. It is the structure which gives.
[0051]
The needles 105 sent out by the feed roller 107 are formed in a U-shape one by one by swinging the forming portion 101 about the rotation shaft 18a in the direction of arrow a in FIG. That is, when the stapler motor 108 is activated, the eccentric cam gear 110 rotates via the gear train 109, and the forming portion 101 is moved in the direction of arrow a in FIG. 13 by the action of the eccentric cam attached integrally with the eccentric cam gear 110. The sheet bundle is stapled by swinging toward the anvil portion 19 side to perform a needle driving operation (clinch operation) and bending the driven needle 105 at the anvil portion 19 on the lower surface of the sheet bundle.
[0052]
In addition, a flag (not shown) is arranged coaxially with the eccentric cam gear 110. By detecting this flag by a stapler sensor (not shown), whether the stapler 18 is clinching or has finished clinching (or clinch start) Before).
[0053]
(Folding means drive mechanism)
Next, a driving mechanism of the sheet bundle folding unit that folds the bound sheet bundle into two at the binding position will be described in detail with reference to FIGS.
[0054]
A folding motor 64 has a pulley 65 fixed on its output shaft. Reference numeral 67 denotes an idler gear pulley, and two pulley portions and one gear portion are formed on the same axis. A timing belt 66 is wound between one pulley portion of the idler gear pulley 67 and the pulley 65. Reference numerals 68 and 69 denote folding gears fixed to the folding rollers 26 and 27 and engaged with each other. One end of the folding gear 68 is engaged with the gear portion of the idler gear pulley 67.
[0055]
Reference numeral 25 denotes a protrusion unit, which includes a protrusion plate 25a, holders 25d and 25b, shafts 25c and 25e, and the like. The protruding plate 25a is held by holders 25d and 25b, and shafts 25c and 25e are fixed to the holder 25b. A roller (not shown) is rotatably attached to the outer periphery of the shafts 25c and 25e, and the roller slides within a groove 8a formed in the frame 8.
[0056]
Reference numeral 73 denotes a gear, which partially includes the shaft 72 and is engaged with the idler gear 75. The idler gear 75 is fixed to the shaft 76, and an electromagnetic clutch (protruding clutch) 74a is disposed on the shaft 76. Transmission of rotation from the pulley 74 to the shaft 76 on the electromagnetic clutch 74a is controlled by turning on / off the power (ON / OFF of the electromagnetic clutch 74a). A timing belt 70 is wound around the outer periphery of the pulley 74. One of the timing belts 70 is wound around the other pulley portion of the idler gear pulley 67.
[0057]
A flag 81 is fixed on the shaft 73a, and the flag 81 has a notch in part. A protruding home sensor 82 is disposed at a position where the flag 81 is detected, and the protruding plate 25a is disposed at a position where the protruding plate 25a is depressed most from the conveying surface of the guides 12 and 21.
[0058]
The rotation of the folding motor 64 is transmitted from the pulley 65 to the idler gear pulley 67 via the timing belt 66. The rotation of the idler gear pulley 67 is transmitted from the folding gear 68 to the folding gear 69, and the folding rollers 26 and 27 are driven. On the other hand, the rotation of the idler gear pulley 67 is transmitted to the pulley 74 on the electromagnetic clutch 74 a via the timing belt 70. By turning ON / OFF the electromagnetic clutch 74a, the rotation of the pulley 74 is transmitted to the shaft 76, and the idler gear 75 rotates. Due to this rotational transition, the gear 73 rotates and the shaft 72 moves circularly. One end of the link 71 is fitted to the shaft 72, and the other end of the link 71 is fitted to the shaft 25c of the protruding unit 25. Therefore, the circular motion of the shaft 72 is transmitted to the shaft 25c of the protruding unit 25 through the link 71, and the shaft 25c is fitted to the groove portion 8a of the frame 8 fitted through the roller (not shown) together with the shaft 25c. Make a linear motion along. That is, the protrusion unit 25 slides in the direction of the arrow in FIG.
[0059]
(Discharge roller drive mechanism)
The drive mechanism of the discharge roller 30 will be described with reference to FIG. As shown in FIG. 3, a pulley 30 f is fixed to a shaft 30 e that is the central axis of the discharge roller 30. A discharge motor 91 has a pulley 92 fixed on the output shaft. A timing belt 93 is wound between the pulley 92 and the pulley 30f. Accordingly, the rotation of the discharge motor 91 is transmitted from the pulley 92 via the timing belt 93 and the pulley 30f is transmitted to drive the discharge roller 30 via the shaft 30e. The discharge motor 91 is a stepping motor, and the peripheral speed of the discharge roller 30 is set faster than the peripheral speed of the folding rollers 26 and 27. Since the conveying force of the folding rollers 26 and 27 is set to be higher than the conveying force of the discharge roller pairs 30 and 31, slipping between the discharge roller pairs 30 and 31 is performed while being nipped and conveyed by the folding rollers 26 and 27. As a result, when the paper passes through the folding rollers 26 and 27, it is conveyed by the conveying force of the discharge roller pair 30 and 31.
[0060]
Further, a discharge paddle (not shown) is disposed in the vicinity of the longitudinal center of the shaft 30e, and at the same time as the discharge roller 30 rotates, the discharge paddle also rotates to reliably discharge the sheet.
[0061]
(Stacker discharge unit drive mechanism)
The drive mechanism of the stacker discharge roller 5 will be described with reference to FIG. As shown in FIG. 3, a pulley 98 is fixed on a shaft 5 a that is the central axis of the stacker discharge roller 5. 95 is a stacker discharge motor, and a pulley 96 is fixed on the output shaft. A timing belt 97 is wound between the pulley 96 and the pulley 98. Accordingly, the rotation of the stacker discharge motor 95 is transmitted from the pulley 96 to the pulley 98 via the timing belt 97, and drives the stacker discharge roller 5 via the shaft 5a. The stacker discharge motor 95 is a stepping motor, and the peripheral speed of the stacker discharge roller 5 is set higher than the peripheral speed of the discharge roller 905a. Since the conveying force of the discharge roller pair 905a and 905b is set higher than the conveying force of the stacker discharge roller pair 5 and 6, the stacker discharge roller pair 5 and 6 is sandwiched and conveyed by the discharge roller pair 905a and 905b. When slipping occurs between the pair of discharge rollers 905a and 905b, the sheet is conveyed by the conveying force of the stacker discharge rollers 5 and 6.
[0062]
(Control system configuration)
The configuration of the control system in the sheet processing apparatus will be briefly described with reference to FIG. In FIG. 7, reference numeral 170 denotes an MPU, and each driver D is based on signals from the sensors 84, 83, A, B, 24e, 63, 33, 82, 29, 34.₁~ D₁₂Via these, the drive of each solenoid 3c, 15d, 16d, each motor 95, 51, 108A, 108B, 24d, 61, 64, 91 etc. is controlled.
[0063]
(Control sequence)
Next, a control sequence of the sheet processing apparatus will be described with reference to FIGS. 1 and 8 to 12.
[0064]
FIG. 8 to FIG. 10 are main routines, and each information (mode information indicating whether the bookbinding mode is the stack mode, the longitudinal length L and the lateral width W of the sheet) from the image forming apparatus main body 900 to which the sheet processing apparatus 2 is connected. When the information, the number information N and the number information M) are received and the start signal is received, the operation of the sheet processing apparatus 2 is started (S201). The mode information is confirmed (S202), and if it is not the bookbinding mode, the routine jumps to the stack mode routine (S205). In the case of the bookbinding mode, it is confirmed whether the vertical length L is between the upper limit Lmax and the lower limit Lmin that can be processed by the sheet processing apparatus 2 (S203). When the range is outside this range, stack mode processing is performed (S205). .
[0065]
Next, in the same manner, it is confirmed whether the width W is between the upper limit Wmax and the lower limit Wmin that can be processed by the sheet processing apparatus 2 (S204). When the width is outside this range, stack mode processing is performed (S205). . If it is within the above range, the inlet solenoid 3c is turned on to open the path to the bookbinding mode (S207). The conveyance motor 51 is turned on to rotate the rollers (S208).
[0066]
Next, the control routine of the switching solenoids 15d and 16d for controlling the switching solenoids 15 and 16 is skipped (S209). The number of steps at which the distance P between the width adjusting members 24a and 24b becomes P = W + α (where α is the gap between the sheet bundle and the abutting portion of the width adjusting member) is sent to the width adjusting motor 24d to be rotated ( S210). The number of steps by which the stopper 23 moves downstream from the staple position 19a of the stapler 18 to a position where l = L / 2 is sent to the stopper motor 61 for rotation. That is, at this time, the center of the sheet is at the same position as the staple position 19a (S211). The number counter CNT1 is set to 0 (S212), and the signal from the inlet sensor 83 is confirmed (S213). If ON, the signal from the inlet sensor 83 is turned OFF (S214), and after a predetermined time t when the leading edge of the sheet bundle hits the stopper 23, P = W−β (β is the width adjusting members 24a and 24b The width adjusting motor 24d is rotated by sending the number of steps for the movement of the width adjusting members 24a and 24b to the position (the amount of pressing) (S215).
[0067]
Subsequently, the number of steps for the movement of the width adjusting members 24a and 24b to the position where P = W + α is sent to the width adjusting motor 24d (S216). The number counter CNT1 is incremented by 1 (S217). It is confirmed whether the number counter CNT1 has reached the desired number N (S218). If the number N has not reached the desired number N, the process returns to S213, and the sheets sent from the image forming apparatus main body 900 are subjected to the same processing. If the desired number N has been reached, the width adjusting members 24a and 24b are rotated in the direction to move outward (S219) and continue until the width adjusting home sensor 24e is turned on (S220). When the width adjusting home sensor 24e is turned on, the width adjusting motor 24d is turned off (S220a).
[0068]
Next, the sheet bundle is stapled.
[0069]
First, stapling by one of the two staplers 18A and 18B is started. The stapler motor 108A is turned on (S221), and when the stapler sensor A is detected (S222), the stapler motor 108A is turned off (S223). Thereafter, the same operation is performed for the stapler 18B (S224 to S226), and the stapling operation is completed.
[0070]
Next, the stopper motor 61 is rotated by a step such that l = (L / 2) + C on the downstream side of the staple position 19a. Here, C is the distance between the staple position 19a and the folding position. At this time, the center (staple position) of the sheet bundle is on the line connecting the nip position of the folding rollers 26 and 27 and the center of the ejection plate 25a (S227). Then, the conveyance motor 51, the inlet solenoid 3c, and the switching solenoids 15 and 16 are turned off to prepare for the folding operation (S228 to S230).
[0071]
After confirming that the stopper sensor 33 is ON (S231), the discharge motor 91 is turned ON (S232), and the folding motor 64 is turned ON (S233). When the protrusion clutch 74a is turned on (S234), the protrusion plate 25a starts to protrude and guides the sheet bundle to the folding rollers 26 and 27.
[0072]
The process continues until the protruding home sensor 82 is turned on (S235). When the protruding home sensor 82 is turned on, the protruding clutch 74a is turned off (S236). The timer is started when the discharge sensor 29 is turned off (S237), and after confirming with the timer that a sufficient time has passed for the trailing edge of the sheet bundle to pass through the discharge roller pair 30, 31, the discharge motor 91 is turned off. (S239). Further, immediately after the discharge sensor 29 is turned off, the speed of the discharge motor 91 is also reduced so that the trailing end of the sheet bundle passes through the discharge roller pairs 30 and 31 at a low speed. The copy counter CNT2 is incremented by 1 (S240). If the number of copies counter CNT2 has not reached the desired number of copies M, the process returns to S206. If the desired number of copies M has been reached, the operation is terminated (S242).
[0073]
Next, a control routine for the switching solenoid will be described with reference to FIGS.
[0074]
Half the sheet size, ie L / 2 is the length k along the guides 11 and 12 to the switching flapper 15₁And constant B (k₁If it is greater than (+ B) (S252), the switching solenoids 15d, 16d remain OFF, and this routine ends. Here, the constant B indicates the position of the rear end of the sheet bundle stacked with the stopper 23 in an appropriate position. This constant B is an amount necessary for the next sheet bundle that has entered the stacked sheet bundle to be stacked at the highest level without entering the stacked sheet bundle.
[0075]
L / 2 is (k₁+ B) is greater than L / 2 (k₂+ B) (S254). Where k₂Is k₁Similarly, the distance between the guides 11 and 12 is the distance to the switching flapper 16. The constant B has the same length as described above. L / 2 is k₂If it is larger than + B (S254), the upper switching solenoid 15d is turned on (S255), and the sheet bundle is guided by the lower switching flapper 16. L / 2 is (k₂If it is smaller than + B), both the switching solenoid upper 15d and the switching solenoid lower 16d are both turned on (S257) and loaded along the guide 11. This is the end of the switching solenoid control routine.
[0076]
Next, the stack mode routine will be described with reference to FIG.
[0077]
The number counter CNT is set to 0 (S272).
[0078]
The stack discharge motor 85 is turned on (S273), and the stack discharge roller 5 is rotated. It is confirmed whether the stack sensor 84 is ON (S275), and if it is ON, it is further confirmed that the stack sensor 84 is OFF (S275). When it is OFF, 1 is added to the number counter CNT (S276), and it is confirmed whether the number counter CNT matches the number N (S277). If the number counter CNT is smaller than N, the process returns to S274. When the number of sheets counter CNT reaches N, the stack discharge motor 85 is turned off after a sufficient time has passed for the trailing edge of the sheet bundle to pass the stack sensor 84 (S278). This completes the stack mode routine (S279).
[0079]
In the embodiment described above, the copying machine is exemplified as the image forming apparatus. However, the image forming apparatus is not limited thereto, and may be another image forming apparatus such as a printer or a printing machine.
[0080]
Further, the path and configuration to reach the post-processing discharge roller are not limited to the above-described embodiment, and for example, a stitcher may be used instead of the stapler as the sheet bundle binding means. Furthermore, the number of staplers used is not limited to two. For example, one or three or more staplers may be used.
[0081]
Furthermore, a configuration in which a large number of conveyance rollers and folding rollers are used to perform reliable conveyance and folding may be used.
[0082]
In the above-described embodiment, the discharge roller 30 is exemplified by a configuration in which four rollers are arranged coaxially. However, the present invention is not limited to this. For example, two rollers near the center of the same size are integrated. Alternatively, three rollers may be used, or more than that may be used. Further, in the above-described embodiment, the roller near the width direction end has a larger outer diameter than the roller near the center, but the roller near the width end is made smaller than the roller near the center. However, the same effect can be obtained. In the above-described embodiment, the configuration having two types of rollers (rollers 30b and 30c and rollers 30a and 30d) having different outer diameters as the second sheet conveying unit is illustrated, but the present invention is not limited to this. For example, it is good also as a structure which has the 3rd and 4th roller from which an outer diameter differs further as needed.
[0083]
Further, in the above-described embodiment, the configuration in which the outer diameter of the discharge roller is changed and the sheet bundle is stiffened is illustrated, but the present invention is not limited to this, for example, as shown in FIG. A configuration may be adopted in which the sheet bundle is stiffened by the discharge roller 30 having an outer diameter and the rib 30g. The outer diameter of the discharge roller 30 is the same, and a discharge roller 31 is in contact with the opposite position. Then, on the same axis of the discharge roller 30, in the vicinity of the end in the width direction, the position is higher (see FIG. 14 (a)) or lower (see FIG. 14 (b)) than the nip position of the discharge roller pair 30, 31. A protruding rib 30g is provided. With this configuration, the vicinity of the center portion of the sheet bundle having a width larger than a predetermined width is nipped and conveyed by the discharge roller pairs 30 and 31, and the vicinity of the end portion is lifted by the rib 30g, and the sheet bundle is conveyed with a vertical stiffness. And the same effects as those of the above-described embodiment can be obtained. Furthermore, according to this configuration, since the discharge roller can be formed by one type of roller, a cheaper roller can be formed.
[0084]
【The invention's effect】
  As described above, according to the present invention, when a sheet bundle is conveyed to the second sheet stacking unit, if the length in the width direction of the sheet bundle is longer than a predetermined length, the sheet bundle is curved in the width direction. However, since the sheet is conveyed with a so-called vertical stiffness, the leading edge of the sheet bundle does not hang in the vertical direction with respect to the second sheet stacking part during the conveyance, and does not cause a stacking failure. On the other hand, when the length in the width direction of the sheet bundle is shorter than a predetermined length, the sheet bundle is conveyed without being curved and without so-called vertical stiffness. Can be prevented. Therefore, the sheet bundle conveyed to the second sheet stacking unit is always conveyed and stacked in the correct state regardless of the size and stiffness.Further, the coefficient of friction of the member forming the second conveying roller is smaller than the coefficient of friction of the member forming the first conveying roller, and the sheet bundle is sandwiched by the first conveying roller. However, when the sheet is conveyed, a roller mark caused by sliding of the sheet bundle is prevented.
[Brief description of the drawings]
FIG. 1 is a longitudinal side view of a sheet processing apparatus according to the present invention.
FIG. 2 is a front view of a discharge roller pair of the sheet processing apparatus as viewed from a discharge port.
FIG. 3 is an explanatory diagram illustrating a configuration of a conveyance mechanism of the sheet processing apparatus.
FIG. 4 is a front view illustrating a configuration of a width adjusting mechanism and a stopper of the sheet processing apparatus.
FIG. 5 is a longitudinal side view of a protruding portion and a folding roller portion of the sheet processing apparatus.
FIG. 6 is a plan view of a protruding portion and a folding roller portion of the sheet processing apparatus.
FIG. 7 is a block diagram of a control system in the sheet processing apparatus.
FIG. 8 is a flowchart showing a main routine by the control system.
FIG. 9 is a flowchart showing a main routine by the control system.
FIG. 10 is a flowchart showing a control routine of a switching solenoid.
FIG. 11 is a flowchart showing a stack mode control routine;
FIG. 12 is a main dimension view of the sheet processing apparatus.
FIG. 13 is a cross-sectional view of a stapler unit of the sheet processing apparatus.
FIG. 14 is a front view of a discharge roller pair according to another embodiment as viewed from a discharge port.
FIG. 15 is a longitudinal front view illustrating an example of an image forming apparatus including the sheet processing apparatus.
FIG. 16 is a longitudinal side view of a conventional sheet processing apparatus.
FIG. 17 is a front view of a conventional sheet processing apparatus as viewed from a discharge port.
[Explanation of symbols]
D ... Original
S ... Sheet
2. Sheet processing device
3 ... Entrance flapper
3a ... Center axis
3b ... Link
3c ... Spring
3d ... Inlet solenoid
4 ... Discharge guide
5 ... Stacker discharge roller
5a ... axis
6 ... Stacker discharge roller
7 ... Stacker tray
8 ... Frame
8a ... Groove
11, 12, 20, 21 ... Guide
13, 17a, 22a ... Conveying roller
13a, 17b, 22b ... central axis
13b, 17c, 22c ... Conveyance roller pulley
14… Conveyor roller
15… on switching flapper
16 ... under the switching flapper
15a, 16a ... Center of rotation
15b, 16b ... Flapper link
15c, 16c ... spring
15d: On switching solenoid
16d: Under switching solenoid
17d, 22d ... elastic member
18 ... Stapler unit
18a ... Rotating shaft
19… Anvil part (folded part)
19a ... Staple point
23… Stopper
23a ...
23b ... pinion gear
23c ... axis
23d ... Stopper gear
23e ... Rack gear
24a, 24b ... Alignment member
24c ... pinion gear
24d ... Alignment motor
24e ... Alignment home sensor
25 ... Extrusion unit
25a ... Extrusion board
25d, 25b ... Holder
25c, 25e ... shaft
26, 27 ... folding rollers
28… Ejection guide
29… Discharge sensor
30 ... Eject roller
30a, 30b, 30c, 30d ... Roller
30e ... axis
30f ... pulley
30g ... ribs
31 ... Discharge roller
32 ... Loading tray
33 ... Sensor
51 ... Conveyance motor
52… Transport motor pulley
53,54 ... Timing belt
61 ... Stopper motor
62 ... Gear
63… Stopper home sensor
64 ... Folding motor
65 ... pulley
66 ... Timing belt
67 ... Idler gear pulley
68, 69 ... folding gear
70 ... Timing belt
71 ... Link
72, 73a, 76 ... axis
73 ... Gear
74 ... pulley
74a ... Electromagnetic clutch
75 ... idler gear
81 ... Flag
82… Home sensor
83… Inlet sensor
84… Stack sensor
91… Discharge motor
92 ... pulley
93 ... Timing belt
95 ... Stacker discharge motor
96, 98 ... pulley
97 ... Timing belt
99 ... support plate
100… Drive unit
101… Driving part (forming part)
102, 111 ... guide members
102a… Guide surface
103 ... Binding surface
104 ... Needle cartridge
105 ... Stitching needle
106… Spring
107… feed roller
108… Stapler motor
109… Gear train
110… Eccentric cam gear
111a ... Notch hole
150 ... Control device
900 ... Image forming apparatus body
901… Registration roller
902 ... Image forming unit
904. Fixing device
905… discharge roller pair
905a ... Discharge roller
905b ... Discharge roller
906… Platen glass
907… Light source
908… Lens system
909 ... Paper feeding unit
910, 911 ... cassette
912… Pedestal
913… deck
914… Photosensitive drum
915… Developer
916… Transfer charger
917… Separation charger
918… cleaner
919… Primary charger
920 ... Conveying device

Claims (3)

A first sheet stacking unit capable of stacking a plurality of sheets, a first sheet transporting unit configured to transport a sheet to the first sheet stacking unit, and an alignment unit configured to align the sheets stacked on the first sheet stacking unit Sheet binding means for binding the aligned plurality of sheets in a substantially central portion in the transport direction by the first sheet transport means, and a sheet bundle for folding the stapled sheet bundle in two at the binding position In a sheet processing apparatus comprising: a folding unit; a second sheet stacking unit that stacks a folded sheet bundle; and a second sheet transport unit that transports the folded sheet bundle to the second sheet stacking unit. ,
When the sheet bundle is conveyed to the second sheet stacking unit, if the length in the width direction perpendicular to the conveyance direction of the sheet bundle is shorter than a predetermined length, the sheet bundle is conveyed without being bent, and the sheet bundle When the length in the width direction is longer than a predetermined length, the sheet bundle is conveyed while being curved in the width direction, and the second sheet conveying means includes a first conveying roller and a second conveying roller having different outer diameters. A sheet bundle having a length in the width direction shorter than a predetermined length is nipped and conveyed by a first conveying roller, and a sheet bundle having a length in the width direction longer than a predetermined length is nipped and conveyed by a first conveying roller. While transporting with the second transport roller so that the vicinity of the width direction end of the sheet bundle is higher or lower than the clamping position of the first transport roller,
The sheet processing apparatus , wherein a coefficient of friction of a member forming the second conveying roller is smaller than a coefficient of friction of a member forming the first conveying roller . A first sheet stacking unit capable of stacking a plurality of sheets, a first sheet transporting unit configured to transport a sheet to the first sheet stacking unit, and an alignment unit configured to align the sheets stacked on the first sheet stacking unit Sheet binding means for binding the aligned plurality of sheets in a substantially central portion in the transport direction by the first sheet transport means, and a sheet bundle for folding the stapled sheet bundle in two at the binding position In a sheet processing apparatus comprising: a folding unit; a second sheet stacking unit that stacks a folded sheet bundle; and a second sheet transport unit that transports the folded sheet bundle to the second sheet stacking unit. ,
When the sheet bundle is conveyed to the second sheet stacking unit, if the length in the width direction perpendicular to the conveyance direction of the sheet bundle is shorter than a predetermined length, the sheet bundle is conveyed without being bent, and the sheet bundle When the length in the width direction is longer than a predetermined length, the sheet bundle is conveyed while being curved in the width direction, and the second sheet conveying means includes a first conveying roller provided near the center in the width direction, A sheet bundle having a second conveying roller having an outer diameter larger than that of one conveying roller and provided near both ends in the width direction is shorter than the interval between the second conveying rollers. The sheet bundle having a length in the width direction longer than the interval between the second conveyance rollers is nipped and conveyed by the first conveyance roller, and the vicinity of both ends in the width direction of the sheet bundle is the first conveyance roller. Carried by the second transport roller so that it is higher than the clamping position As well as,
The sheet processing apparatus , wherein a coefficient of friction of a member forming the second conveying roller is smaller than a coefficient of friction of a member forming the first conveying roller . An image forming apparatus comprising the sheet processing apparatus according to claim 1 .

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