JP6691719B2 - Sheet binding apparatus, sheet processing apparatus and image forming apparatus including the same - Google Patents

Description

  The present invention relates to a sheet binding apparatus that binds a sheet bundle including a plurality of sheets without using a binding needle, a sheet processing apparatus including the same, and an image forming apparatus.

  Conventionally, binding of paper has been performed using a metal binding needle, but when discarding unnecessary paper, the work of removing the binding needle has been troublesome. Therefore, when binding the paper, without using a binding needle, after permeating water at the binding position, a binding device for binding the paper by pressing a plurality of paper with a pressure member has been proposed. (See Patent Document 1).

Japanese Patent No. 3481300

  In the device described in Patent Document 1, the fibers of the paper are loosened by allowing water to permeate the plurality of papers, and the plurality of papers are collectively pressed, whereby the fibers of the papers are mechanically entangled with each other. The papers are pressed together. However, the device described in Patent Document 1 cannot adjust the amount of water to be permeated when conditions such as the number of sheets of paper to be bound and the type of paper are changed.

  Then, when water is permeated into a plurality of papers in this way, when the amount of water is too large, the fibers become too loose at the time of pressing and stick to the pressure member as waste paper, when binding the next bundle of papers. In addition, the waste paper becomes an obstacle and a good binding force cannot be obtained. Further, there is a problem that even if the amount of water is small, the fibers of the paper are not loosened sufficiently and a good binding force cannot be obtained.

  Therefore, it is an object of the present invention to provide a sheet binding device capable of favorably binding a sheet bundle, a sheet processing device and an image forming apparatus including the same.

The sheet binding device of the present invention is a binding device that binds a sheet bundle forming unit that stacks a plurality of sheets to form a sheet bundle and a sheet bundle that is formed by the sheet bundle forming unit without using a binding needle. before performing means, the pre Kitsuzuri Ji treatment, and water application means for applying water to a binding position prior Kitsuzuri Ji to be processed of the sheet bundle, control for controlling the said binding means the water application means When the number of sheets in the sheet bundle is equal to or less than a predetermined number, the sheet bundle is formed after the formation of the sheet bundle is completed without applying water to the sheets before the formation of the sheet bundle is completed. When the binding process is performed after applying water, and the number of sheets in the sheet bundle exceeds the predetermined number, the water of the sheet bundle is applied after the formation of the sheet bundle is completed, and then the sheet bundle spelling While performing the process, before the formation of the sheet bundle is completed, for the predetermined number of sheets or less located at the binding position, water is applied before the next sheet is conveyed to the binding position, and thereafter, And a control means for controlling the water application interval such that the number of sheets conveyed to the binding position at the interval is equal to or less than the predetermined number .

  According to the present invention, an appropriate amount of water can be applied to a sheet bundle to satisfactorily bind the sheet bundle.

FIG. 1 is an overall sectional view showing an image forming apparatus according to an embodiment of the present invention. The front view which shows the pressing means which concerns on embodiment of this invention. The figure which looked at the sheet binding device which concerns on embodiment of this invention from the X arrow direction of FIG. The front view which shows the pressing means in the state which the cover frame which concerns on embodiment of this invention was removed. FIG. 3 is a perspective view showing a lower support and an upper support according to the embodiment of the present invention. The figure which shows the state which the lower tooth type member 41a and the upper tooth type member 50a which meshed with embodiment of this invention meshed. The control block diagram which concerns on embodiment of this invention. The front view which shows the home position of the pressing means which concerns on embodiment of this invention. 6 is a flowchart showing the operation of the sheet binding device according to the embodiment of the present invention. FIG. 4 is a front view showing a state in which the sheet bundle has entered the pressing means according to the embodiment of the present invention. FIG. 4 is a left side view showing a state in which the sheet bundle has entered the sheet binding device at the pressing position according to the embodiment of the present invention. FIG. 4 is a left side view showing a state in which the sheet bundle has entered the sheet binding device at the pressing position according to the embodiment of the present invention. The front view which shows the state which the pressing means which concerns on embodiment of this invention is pressing the sheet bundle. The front view which shows the state which the pressing means which concerns on embodiment of this invention released the sheet bundle.

  Embodiments of the present invention will be described below with reference to the drawings. As shown in FIG. 1, a laser beam printer 1 as an image forming apparatus includes a sheet conveying unit 2, an image forming unit 3, a sheet post-processing unit 4, and an image reading unit in order from the lower side of the laser beam printer 1. The unit 5 and the automatic document feeder 6 are provided.

  The sheet conveying unit 2 includes a plurality of sheet feeding cassettes 10 that store sheets P of different sizes, a pickup roller 11 that feeds the sheets P in the sheet feeding cassette 10 one by one, and the sheets P to the image forming unit 3. It has a conveyance roller 12 that conveys toward and the like.

  The image forming unit 3 includes a photosensitive drum 13, a charging roller 14, an exposure unit 15, a developing device 16, a transfer roller 17, a fixing device 18, and the like. The photosensitive drum 13 rotates in the direction of the arrow in the figure, and the charging roller 14 uniformly charges the surface thereof. The charged photosensitive drum 13 is exposed by the laser beam of the exposure unit 15 whose on / off control is performed based on the image information, and the charge of the exposed portion is removed to form an electrostatic latent image. The developing device 16 attaches toner to the electrostatic latent image to form a toner image, and the transfer roller 17 transfers the toner image onto the sheet P conveyed from the sheet conveying section 2. The sheet P on which the toner image is transferred is heated and pressed by the fixing device 18 to fix the toner image on the surface, and is conveyed to the sheet post-processing unit 4.

  The sheet post-processing unit 4 has a sheet binding device 30 described later. The sheet P conveyed from the image forming unit 3 to the sheet post-processing unit 4 is discharged to the discharge tray 19 without being processed by the sheet binding device 30 after being stacked or bound by the sheet binding device 30. To be done.

  The image reading unit 5 includes a platen glass 20, a lamp 21, a plurality of mirrors 22, a lens 23, an image sensor 24, and the like. The image information of the document D sent from the automatic document feeder 6 is read when passing through the image reading position R on the platen glass 20. That is, the light emitted from the lamp 21 passes through the platen glass 20 and is reflected on the surface of the document, and is guided to the image sensor 24 via the plurality of mirrors 22 and the lenses 23. Read as information. The image information is subjected to predetermined image processing and transmitted to the exposure unit 15 of the image forming unit 3.

  The automatic document feeder 6 has a document tray 25, a paper discharge tray 26, and a binding sheet number detecting means 72 (see FIG. 7). The documents D placed on the document tray 25 are transported one by one by a transport roller (not shown), pass through the image reading position R of the image reading unit 5, and are discharged to the paper discharge tray 26. The bound number detecting unit 72 counts the number of documents D on the document tray 25 conveyed by one document reading operation. The number of documents D is the same as the number of sheets P of the sheet bundle PB that are bound in the binding process described later. That is, the bound number detecting unit 72 detects the number of sheets P of the bound sheet bundle PB.

  Next, the sheet binding device 30 will be described in detail. In the following, for convenience of description, the up, down, left, and right directions indicated by the arrows in FIG. 2 correspond to the up, down, left, and right of the sheet binding device 30 and each member and the like constituting the sheet binding device 30. Further, a direction (ZY direction shown in FIG. 3) orthogonal to these vertical and horizontal directions is referred to as a front-back direction. However, these front-rear, left-right and up-down directions defined for convenience do not limit the configuration and operation of the sheet binding device 30 and the like.

  As shown in FIGS. 2 and 3, the sheet binding device 30 includes a pressing unit 40 as a binding unit that holds and presses a sheet bundle PB in which a plurality of sheets P are stacked in the stacking direction, and a sheet bundle PB. And a water application means 60 for applying water to the binding position. The pressing means 40 and the water application means 60 are fixed to the unit support base 31 and the unit loading plate 32 (see FIG. 11), and the unit movement motor 34 for driving the pinion gear 33 is fixed to the unit support base 31. (See FIG. 11). A rack gear 36 meshing with the pinion gear 33 is fixed to the guide plate 35 fixed to the laser beam printer 1. By driving the unit moving motor 34, the pressing means 40 and the water applying means 60 fixed to the unit loading plate 32 can be moved in the YZ direction with respect to the guide plate 35. The sheet binding device 30 fixed to the unit stacking plate 32 is guided by the guide shaft 37 to a predetermined water application position where the sheet bundle PB is coated with water, and a pressing position where the pressing unit 40 presses the sheet stack PB. , Can be moved to and held.

  The water application unit 60 includes a tank cartridge 61 that stores water, a water application device 62 that has water jetting units 62a and 62b that jets water, and a pump 63 that sends water from the tank cartridge 61 to the jetting units 62a and 62b. Have The water application device 62 is configured such that water is supplied from the tank cartridge 61 by the pump 63 and a predetermined amount of water is sprayed in a mist form from the spraying parts 62a and 62b in the vertical direction of the water coating space 62c.

  The pressing means 40 has a lower support base 41 fixed to the raised portion 31a of the unit support base 31 and a cover frame 42 fixed to the lower support base 41 (see FIG. 11). The cover frame 42 has a front wall portion 42a, a rear wall portion 42b, and a top portion 42c connecting the upper ends of the front wall portion 42a and the rear wall portion 42b, and has an opening in the direction of the arrow X. It is formed in a U shape with the portion facing downward. Each of the front wall portion 42a and the rear wall portion 42b has a pin 42d projecting outward at the lower portion on the left end side, and a long hole 42e is obliquely formed above the pin 42d. A front end and a rear end of a cam drive shaft 43, which will be described later, pass through the elongated holes 42e, 42e. The long holes 42e, 42e support the cam drive shaft 43 movably and rotatably along the longitudinal direction of the long holes 42e, 42e.

  Between the pin 42d and the tip of the cam drive shaft 43 protruding from the elongated hole 42e, tension springs 44, 44 are stretched on the front and rear sides of the cover frame 42, respectively. On the right end side of the front wall portion 42a, a long hole 42f is formed at a position corresponding to a cam drive motor 55 described later. The cover frame 42 receives the reaction force of a cam 46, which will be described later, by the elongated holes 42e, 42e described above.

  As shown in FIG. 4, the pressing means 40 has a fixed frame 47 whose right end side is fixed to the upper surface of the lower support base 41 and whose lower end 47a on the left end side faces the lower support base 41 with a gap G therebetween. is doing. The fixed frame 47 has a U-shape similar to the cover frame 42 described above in the direction of the arrow X, and is arranged so that the right end side is covered by the cover frame 42. Three shafts S1, S2, S3 penetrate through the fixed frame 47 in order from the left.

  A swing frame 48 is disposed above the fixed frame 47. The swing frame 48 has a U-shape similar to the cover frame 42 described above in the direction of the arrow X, and its left end. The lower portion 48 a on the side is formed so as to cover the fixed frame 47. Shafts S1 and S2 pass through the lower portion 48a. The swing frame 48 is swingable about the left end side shaft S1 in a substantially vertical direction with respect to the fixed frame 47 on the right end side. The right end portion of the upper surface of the swing frame 48 is a contact surface 48b with which the cam surface 46a of the cam 46 abuts.

  A pressing frame 49 is arranged inside the fixed frame 47, and the pressing frame 49 has a U-shape that opens in an upward direction in the X arrow direction. The pressing frame 49 has a shaft S2 penetrating the left end side and a shaft S3 penetrating the right end side. The left end side of the pressing frame 49 can swing substantially vertically with respect to the lower support base 41 with the shaft S3 as a fulcrum.

  An upper support base 50 is fixed to the lower surface of the pressing frame 49 on the left end side. An upper tooth mold member (pressing member) 50a having a corrugated shape as shown in FIGS. 5 and 6 is fixed to the lower surface of the upper support base 50. The member 50a is adapted to mesh with the lower tooth type member (pressing member) 41a fixed to the lower support base 41 when the pressing frame 49 descends.

  The shaft S2 is fixed to the left end side of the pressing frame 49 so as to penetrate the pressing frame 49, and the front end and the rear end thereof are formed in the swing frame 48 by penetrating the fixed frame 47 in the front-rear direction. Engaged with the through holes 48c, 48c. It should be noted that the portion of the fixed frame 47 through which the shaft S2 penetrates has an appropriate margin in consideration of the fact that the shaft S2 swings around the shaft S3 and the through holes 48c, 48c swing around the shaft S1. Is formed with.

  A compression spring 52 is compressed between the fixed frame 47 and the swing frame 48. The swing frame 48 is urged substantially upward by the compression spring 52, and the contact surface 48b is brought into contact with the minimum radius portion of the cam surface 46a of the cam 46. This state becomes the home position of the cam 46, and the gap H (see FIG. 8) between the lower tooth type member 41a and the upper tooth type member 50a becomes maximum.

  The cam drive shaft 43 is biased substantially downward by the tension springs 44, 44, but the biasing force of the tension springs 44, 44 is set to be weaker than the biasing force of the compression spring 52. Therefore, the swing frame 48 is urged substantially upward by the compression spring 52 so that its abutment surface 48b abuts on the cam 46, and the abutment surface 48b is urged substantially downward by the tension springs 44, 44. The biased cam 46 comes into contact.

  The drive means 53 for oscillating the oscillating frame 48 is integrated with the cam drive motor 55 for driving the motor gear 54, the drive transmission gear 56 meshing with the motor gear 54, and the cam drive shaft 43 meshing with the drive transmission gear 56. Fixed gear (not shown) and a cam 46. As the cam drive motor 55, a stepping motor that can accurately control the rotation angle by the CPU 70 (see FIG. 7) is used. The cam surface 46a of the cam 46 is formed so that the radius gradually increases clockwise and counterclockwise with reference to the minimum radius portion. The rotation of the cam drive motor 55 is transmitted to the cam 46 via the motor gear 54, the drive transmission gear 56, the fixed gear and the cam drive shaft 43.

  FIG. 7 shows a control block diagram of the laser beam printer 1 according to the present embodiment, and the laser beam printer 1 has a CPU 70 as control means and ROM, RAM and the like (not shown). To the input side of the CPU 70, for example, a sheet information input unit 71 formed of a liquid crystal monitor having a touch sensor and the bound number detecting unit 72 are connected. In the sheet information input unit 71, the paper type of the sheets P stored in the plurality of paper feed cassettes 10 can be set for each paper feed cassette. The paper type refers to the paper type of the sheet P such as plain paper, recycled paper, and thick paper. The pump 63 is connected to the output side of the CPU 70 via a pump controller 73. Further, the unit moving motor 34 and the cam driving motor 55 are connected to the output side of the CPU 70 via a motor controller 74.

  Next, the operation of the sheet binding device 30 having the above configuration will be described with reference to FIGS. The sheet binding device 30 stands by at the water application position shown in FIG. 11, and at this time, the pressing means 40 is at the home position position shown in FIG. At this time, the gap H between the lower tooth type member 41a and the upper tooth type member 50a has the maximum width. The gap H is arranged within the height of the water application space 62c of the water application device 62.

  Then, the sheet binding device 30 operates as in the flowchart shown in FIG. That is, the CPU 70 determines whether or not the sheet bundle PB to be bound is a condition that allows water to permeate at once (step S1). This condition is information about the sheet bundle such as the number of sheet bundles PB and the type of paper. When it is determined in step S1 that the condition that water can be permeated at one time is satisfied, the plurality of sheets P on which images are formed in the image forming unit 3 are stacked and stacked as shown in FIGS. The sheet bundle PB is aligned and enters the gap G from the left side. The sheet bundle PB that has entered the gap G is arranged at a predetermined position shown in FIGS. 9 and 10 by a stopper (not shown) (step S2). At the predetermined position, the sheet bundle PB is partially arranged in the water application space 62c and between the lower tooth type member 41a and the upper tooth type member 50a.

  Next, the CPU 70 calculates the amount of water to be applied to the sheet bundle PB based on the number of sheets of the sheet bundle PB detected by the binding number detecting unit 72 and the paper type information input by the sheet information input unit 71, A command is transmitted to the pump 63 (step S3). The amount of water to be applied to the sheet bundle PB is determined by experimentally finding the optimum amount of application from the information on the number of sheets of the sheet bundle to be bound and the paper type and tabulating the optimum application amount. Then, the pump 63 supplies a predetermined amount of water from the tank cartridge 61 to the jetting units 62a and 62b of the water applying device 62, and the jetting units 62a and 62b are placed at the binding position of the sheet bundle PB in the amount calculated in step S3. Water is applied (step S4). The binding position is usually somewhere near the peripheral portion of the sheet bundle PB. The amount of water applied by the injection units 62a and 62b is adjusted by changing the injection time or the injection amount of water per unit time.

  When the CPU 70 determines in step S1 that the condition that allows water to permeate at once is not satisfied, the sheet bundle PB is divided into a predetermined number of sheets (every plurality of sheets) and the water is applied stepwise. To do. For example, if the sheet bundle PB is composed of 10 sheets P and water cannot be permeated at one time, water is applied every five sheets that can permeate water at one time. That is, first, a sheet bundle in which five sheets P are stacked (this sheet bundle is referred to as a sheet bundle PB1 for convenience) is conveyed to a predetermined position in the gap G (step S5). Then, as in steps S3 and S4 described above, water is applied to the sheet bundle.

  Next, the CPU 70 determines whether or not all the sheets P of the sheet bundle PB to be bound have been transported (step S6). If all the sheet bundles PB to be bound have not been transported, the process returns to step S5, and the step S5, S3, S4 and S6 are repeated. In the above-mentioned example, after water is applied to the sheet bundle PB1, a new five sheet bundle (this sheet bundle is referred to as a sheet bundle PB2 for convenience) is formed on the sheet bundle PB1 already applied with water. Will be transported. Then, water is applied to the sheet bundle PB2, but since there is the sheet bundle PB1 to which water has already been applied below, water is applied only from the upper jetting unit 62a. The sheet bundle PB2 absorbs water from the sheet bundle PB1 to which water has already been applied from below, and is sufficiently applied with water at the binding position. When the water is applied to the sheet bundle PB in a plurality of times, the method of dividing the sheet bundle PB may be freely set as long as it is equal to or less than the number of sheets in which water can be applied at one time. For example, even in the case of the 10-sheet bundle PB described above, the sheet bundle PB1 may be composed of 6 sheets P and the sheet bundle PB2 may be composed of 4 sheets P.

  In step S6, all the sheets P forming the sheet bundle PB to be bound are conveyed to the water application position, and when water is applied, the unit moving motor 34 is rotated by a predetermined amount in the forward direction (step S7). As a result, the sheet binding device 30 moves in the Y direction from the water application position shown in FIG. 11 by the meshing of the pinion gear 33 and the rack gear 36, and stops at the pressing position shown in FIG. 12 (step S8). At the pressing position, the binding position of the sheet bundle PB coated with water is arranged between the lower tooth type member 41a and the upper tooth type member 50a.

  Next, the cam drive motor 55 is rotated forward by a predetermined amount to rotate the cam 46 in the R1 direction as shown in FIG. 13 (step S9). Then, when the cam 46 comes into contact with the contact surface 48b of the swing frame 48 by a predetermined amount, the rotation of the cam 46 is stopped (step S10). As a result, the swing frame 48 rotates about the axis S1 in the K1 direction, and the pressing frame 49 to which the upper support 50 is fixed rotates about the axis S3 in the M1 direction. The sheet bundle PB disposed between the lower tooth type member 41a and the upper tooth type member 50a is stacked in the stacking direction by the lower tooth type member 41a and the upper tooth type member 50a at the binding position where water is applied. It is clamped and a pressing force is applied (step S11). Thus, the unevenness is formed at the binding position of the sheet bundle PB, and the fibers of the plurality of sheets P are intertwined with each other and bound. The pressing force required to bind the sheet bundle PB can be obtained by sufficiently decelerating the rotation of the cam drive motor 55 to the cam 46.

  When the binding process for the sheet bundle PB is completed, the cam drive motor 55 is rotated in the reverse direction to rotate the cam 46 in the R2 direction as shown in FIG. 14 (step S12). As a result, the swing frame 48 rotates in the K2 direction about the axis S1, and the pressing frame 49 to which the upper support 50 is fixed rotates in the M2 direction about the axis S3. Then, the upper tooth type member 50a is separated from the sheet bundle PB, the sheet bundle PB is released from the sandwiched state (step S13), and is discharged to the discharge tray 19 by the sheet conveying unit (not shown) (step S14).

  As described above, the sheet binding device 30 according to the present embodiment can apply an appropriate amount of water according to the number of sheets P to be bound and the paper type, and thus can be applied to a different number of sheets and a sheet bundle of paper types. Then, the sheet bundle can be satisfactorily bound. When water cannot be penetrated into the sheet bundle to be bound with a single application of water, the water is applied stepwise in multiple times, so the surface condition of the sheet bundle when applying pressing force Is kept good, and it is difficult for waste paper to stick to the lower tooth type member 41a and the upper tooth type member 50a.

  In the above-described embodiment, the lower tooth type member 41a is fixed and the upper tooth type member 50a is moved among the pair of tooth type members, but the present invention is not limited to this. For example, the lower tooth mold member 41a may be moved to fix the upper tooth mold member 50a, or both the lower tooth mold member 41a and the upper tooth mold member 50a may be moved. ..

  Further, although the electrophotographic laser printer has been described as the image forming apparatus, the present invention is not limited to this. For example, the image forming apparatus may be an image forming apparatus such as a copying machine or a facsimile machine, or another image forming apparatus such as a multi-function machine that combines these functions. Further, in an image forming apparatus in which the automatic document feeder 6 is not provided, the number of sheets to be bound may be manually set by the sheet information input unit 71.

  Further, in the above-described embodiment, the conditions that allow water to permeate the sheet bundle at one time and the amount of water to be applied are determined according to the number of sheets to be bound or the type of paper, but other basis weights, surface properties, etc. These may be determined based on the information regarding the sheet bundle. Further, the sheet information input unit 71 may be configured to be able to manually input each of these sheet information.

30: sheet binding device, 40: pressing means, 60: water application means, 70: CPU (control means), P: sheet, PB: sheet bundle

Claims (6)

Sheet bundle forming means for forming a sheet bundle by stacking a plurality of sheets,
Binding means for binding the sheet bundle formed by the sheet bundle forming means without using a binding needle;
Before performing the binding process, a water application unit that applies water to the binding position of the sheet bundle to be bound.
Control means for controlling the binding means and the water application means, wherein when the number of sheets in the sheet bundle is equal to or less than a predetermined number, water is not applied to the sheets before the formation of the sheet bundle is completed. When the binding process is performed after applying water to the sheet bundle after the formation of the sheet bundle is completed, and the number of sheets in the sheet bundle exceeds the predetermined number, the sheets are formed after the formation of the sheet bundle is completed. While performing the binding process of the sheet bundle after applying water to the bundle, the next sheet is the following sheets for the predetermined number of sheets or less located at the binding position before the formation of the sheet bundle is completed. Water is applied before being conveyed to the binding position, and then the water application interval is set so that the number of sheets conveyed to the binding position at the interval becomes the predetermined number or less. And control means for controlling to,
A sheet binding device comprising: The binding means is for pressing a sheet bundle by a pressing member to perform binding processing, and unevenness is provided on a contact surface of the pressing member with the sheet bundle,
The sheet binding device according to claim 1, wherein: The water application means applies water toward the thickness direction of the sheet bundle,
The sheet binding device according to claim 1 or 2, characterized in that. The water application means applies the water without opening a gap in the sheet bundle,
The sheet binding device according to any one of claims 1 to 3, wherein: A sheet binding device according to any one of claims 1 to 4,
A sheet conveying device that conveys a sheet to the sheet binding device,
A sheet processing apparatus characterized by the above. Image forming means for forming an image on a sheet,
An image forming apparatus comprising: a sheet processing apparatus capable of processing a sheet conveyed from the image forming means ,
The sheet processing apparatus is the sheet processing apparatus according to claim 5 .
An image forming apparatus characterized by the above.

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