JP5412419B2 - Paper post-processing device - Google Patents

Description

  The present invention relates to a paper post-processing apparatus that performs predetermined post-processing such as folding processing on paper supplied from an image forming apparatus such as a copying machine, a printer, or a facsimile machine.

  An image forming apparatus typified by a copying machine may be provided with a paper post-processing device that performs predetermined post-processing on paper discharged after printing is completed. The paper post-processing device is often placed adjacent to the image forming apparatus, and after performing stapling processing for punching the paper, punching for punching the paper, folding processing for folding the paper, etc., the paper is discharged. Drain to the department.

  In the paper folding process in the paper post-processing apparatus, in general, the paper is often folded in a crease in the paper width direction perpendicular to the paper transport direction. For example, a blade-like member extending in the width direction of the paper from one side of the paper that has reached the position of the folding portion where the paper is bent is pressed against the other side. Is pushed in the normal direction, and a crease is formed at the portion, and the fold is conveyed as it is with the downstream end in the conveyance direction and discharged to the paper discharge unit.

  Here, in the paper folding process, for example, if the folding method is insufficient, there is a concern that the crease portion of the paper may swell. As a result, the paper may unintentionally become bulky at the paper discharge unit. When a plurality of sheets are stacked and folded to form a booklet, the crease may be further swelled, which may further deteriorate the bulkiness of the sheet in the sheet discharge section. As a result, for example, when the upper limit of the folded paper discharged to the paper discharge unit is detected to determine whether the paper discharge unit is full, although it is clearly smaller than the amount of paper that can be originally accommodated in the paper discharge unit, There is a risk of being determined to be full.

  Thus, an example of an apparatus that prevents a sheet crease from expanding in a sheet post-processing apparatus that performs a folding process on a sheet can be seen in Japanese Patent Application Laid-Open No. H10-228707. In a sheet processing apparatus (sheet post-processing apparatus) described in Patent Document 1, a sheet bundle is saddle-stitched by a sheet binding unit such as a stapler unit, and is bent at the center binding part to be folded in half. By adjusting the holding time of the folded sheet bundle in accordance with the load at the time of sheet binding, it is possible to prevent the folded portion of the sheet bundle from expanding while preventing unnecessary reduction in productivity.

JP 2007-119197 A

  However, even when the sheet processing apparatus described in Patent Document 1 is used, it is difficult to completely prevent the bulging that occurs at the fold portion of the sheet. Therefore, there is a possibility that the method of detecting the upper limit of the sheet that is generally widely used when determining the fullness of the sheet discharge unit cannot achieve the amount of sheets that can be originally accommodated in the sheet discharge unit. . As a result, the work efficiency related to the paper folding process is reduced, and the user may feel uncomfortable with the poor usability. Moreover, since it is necessary to provide a dedicated sensor for detecting the upper limit of the sheet, there is a concern about the cost increase of the apparatus.

  The present invention has been made in view of the above points, and when discharging a folded sheet to the sheet discharge unit, a dedicated sheet upper limit detection sensor or the like is provided to determine whether the sheet discharge unit is full. It is an object of the present invention to provide a sheet post-processing apparatus that can determine whether a sheet discharge unit is full after accommodating as many sheets as possible in a sheet discharge unit with a simple configuration.

  In order to solve the above-described problems, a sheet post-processing apparatus according to the present invention stacks and stores a folding unit that performs a folding process in a manner that folds the sheet, and a sheet that has been subjected to the folding process by the folding unit. A paper discharge unit, a motor for conveying the paper that has been subjected to the folding process in the bending unit toward the paper discharge unit, a rotation speed detection unit for detecting the rotation speed of the motor, and a paper A storage unit for storing a predetermined full condition for determining whether the paper discharge unit is full based on a rotational load generated in the motor identified from a change in rotational speed of the motor during conveyance; The rotation speed of the motor is detected on the basis of the output obtained from the rotation speed detection section every time the sheet after being bent in the section is conveyed, and the rotation speed of the motor is stored in the storage section. And determining the control unit to the sheet discharge unit when filled with 憶 been predetermined full condition is full, it was decided to include the.

  According to this configuration, the sheet post-processing apparatus determines the rotation speed of the motor during the conveyance of each sheet based on the output obtained from the rotation speed detection unit each time the sheet after the folding process is performed by the folding unit is conveyed. Detect. The paper post-processing apparatus determines that the paper discharge unit is full when it recognizes that the rotational speed of the motor during paper transport satisfies a predetermined full condition that is predetermined based on the rotational speed of the motor. Therefore, the paper post-processing device uses the rotational speed of the motor to determine whether the paper discharge unit is full. It can be expected to accommodate as much paper as possible. Further, since the rotational speed of the motor may be detected in order to realize proper paper conveyance, it is not necessary to provide a dedicated paper upper limit detection sensor in order to detect the fullness of the paper discharge unit.

  In the sheet post-processing apparatus having the above-described configuration, the storage unit is a threshold value related to an output value of the rotation speed detection unit, and the sheet conveyance by the motor is in a normal conveyance state, or the motor of the motor is more than in the normal conveyance state. A threshold value for determining whether the rotational load is a high load conveyance state, and condition data for determining that the paper discharge unit is full based on the number of occurrences of each conveyance state, the predetermined full condition And the control unit determines whether the rotational load of the motor is based on the output obtained from the rotational speed detection unit and the threshold value each time the paper after being folded in the folding unit is conveyed. When the normal conveyance state or the high-load conveyance state is detected and it is identified that the condition data is satisfied, it is recognized that the predetermined full condition is satisfied.

  According to this configuration, the number of times the sheet post-processing device is in a high load conveyance state in which the rotation speed of the motor at the time of sheet conveyance obtained as an output value of the rotation speed detection unit is less than a threshold, and the high load conveyance state is obtained. Is recognized as satisfying the predetermined condition data. Therefore, the sheet post-processing apparatus determines whether the sheet discharge unit is full based on the number of times the sheet conveyance by the motor is in the high load conveyance state and the condition data set based on the number of times.

  In the sheet post-processing apparatus having the above-described configuration, the storage unit may perform the high load from the first time to a predetermined number of times with respect to the number of times the sheet is conveyed toward the sheet discharge unit using the motor. Information on how many times the conveyance state is detected to determine that it is full, and how many times the high load conveyance state is detected between the predetermined number of times and a predetermined upper limit number of times Information and information that it is determined that the upper limit number of times is full regardless of the conveyance state are stored as the condition data.

  According to this configuration, the number of times the sheet post-processing apparatus transports the sheet toward the sheet discharge unit is detected from the first time to the specified number of times, and the upper limit number of times exceeds the specified number of times. The fullness of the paper discharge unit is determined based on the number of high-load conveyance states detected during this period and whether or not the upper limit number has been reached regardless of the conveyance state.

  Further, in the sheet post-processing apparatus having the above configuration, when the control unit determines that the sheet discharge unit is full, the sheet discharge unit removes a sheet in the middle of conveyance from the folding unit to the sheet discharge unit. The paper folding process by the folding unit is stopped.

  According to this configuration, even when it is determined that the paper discharge unit is full, the paper that has been subjected to the bending process before the determination is appropriately conveyed to the paper discharge unit, which causes problems such as jamming during the conveyance. Without being stored in the paper discharge unit.

  Further, in the paper post-processing apparatus having the above configuration, the rotation speed detection unit includes an optical sensor having a light emitting unit and a light receiving unit, and a pulse plate having an opening through which light from the optical sensor passes, and the control The unit detects the rotational speed of the motor by counting light passing through the opening per unit time.

  According to this configuration, the sheet post-processing apparatus detects the rotation speed of the motor necessary for determining whether the sheet discharge unit is full by using the rotation speed detection unit having a simple configuration using the optical sensor and the pulse plate.

  According to the configuration of the present invention, when the paper subjected to the bending process is discharged to the paper discharge unit, it is determined whether the paper discharge unit is full by using the rotation speed of the motor. With the simple configuration without providing a paper, the paper discharge unit is determined to be full after storing as much paper as possible in the paper discharge unit, regardless of the number of sheets in the folds or the number of sheets to be folded. Therefore, it is possible to provide a sheet post-processing apparatus that can perform the above-described processing.

It is a model vertical cross section front view of the paper post-processing apparatus which concerns on embodiment of this invention. FIG. 2 is a block diagram illustrating a configuration of the sheet post-processing apparatus of FIG. 1. FIG. 2 is a vertical sectional front view of a folding processing unit of the paper post-processing apparatus of FIG. 1. It is a schematic perspective view of the rotational speed detection part of the bending process unit shown in FIG. It is explanatory drawing which shows the predetermined full condition of the booklet discharge tray of a bending process unit, and the table | surface which shows the example of paper discharge | emission. It is a flowchart which shows the operation | movement which concerns on full determination of a booklet discharge tray.

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

  First, the outline and the operation of the sheet post-processing apparatus according to the embodiment of the present invention will be described with reference to FIGS. 1 and 2. FIG. 1 is a schematic vertical sectional front view of a paper post-processing apparatus, and FIG. 2 is a block diagram showing the configuration of the paper post-processing apparatus. Note that the dotted arrows in FIG. 1 indicate the sheet conveyance path and conveyance direction.

  As shown in FIG. 1, the sheet post-processing apparatus 1 is detachably connected to the sheet discharge side of the image forming apparatus 100. The image forming apparatus 100 is on the right side of the sheet post-processing apparatus 1 in FIG. The sheet post-processing apparatus 1 includes a punching apparatus 2, a staple processing unit 20, and a folding processing unit 30 in order to perform punching, stapling, and folding on the sheet discharged from the image forming apparatus 100.

  The punching device 2 is disposed above the paper post-processing device 1 and immediately downstream of the paper carry-in port 3 for receiving the paper discharged from the image forming apparatus 100 in the paper conveyance direction. The paper carry-in port 3 is provided on the side surface of the paper post-processing apparatus 1 on the side where the image forming apparatus 100 is disposed, that is, the right side surface in FIG.

  The paper discharged from the image forming apparatus 100 reaches the location of the punch device 2 immediately after passing through the paper carry-in port 3. When the paper post-processing device 1 receives a punch processing command, the punch device 2 performs punch processing for punching the paper. The sheet that has passed through the portion of the punching device 2 reaches the sheet distribution unit 4 downstream in the sheet conveyance direction.

  The paper sorting unit 4 is provided with a plurality of movable guides 5. Each movable guide 5 is provided so as to be rotatable about an axis extending in the paper width direction perpendicular to the paper transport direction, that is, the paper surface depth direction in FIG. The movable guide 5 has a wedge shape when viewed from the axial direction whose shape is the center of rotation, and switches and distributes the paper transport direction.

  The paper distribution unit 4 distributes the paper to the main discharge tray 6 or the sub discharge tray 7 when no processing is performed on the paper that has passed through the punch device 2. The main discharge tray 6 and the sub discharge tray 7 are provided in two stages in the vertical direction on the upper left side of the sheet post-processing apparatus 1 in FIG. The paper sorting unit 4 sorts the paper downward when further stapling or folding is performed on the paper.

  The staple processing unit 20 is disposed below the punch device 2 and the paper sorting unit 4 and at a substantially central portion in the vertical direction of the paper post-processing device 1. The staple processing unit 20 includes a stack tray 21, a cover tray 22, a lower end stopper 23, an upper end presser 24, a moving mechanism 25, and a stapling device 26.

  The stack tray 21 and the cover tray 22 are arranged to face each other with a predetermined space therebetween. This space is a sheet processing space S, which is formed so as to extend up and down at an angle slightly inclined from the vertical direction, and the sheet conveyed from above is fed into this space.

  A lower end stopper 23 is provided at the lower end of the sheet processing space S of the stack tray 21, and an upper end presser 24 is provided at the upper end. The lower end stopper 23, the upper end pressing member 24, and the paper in the paper processing space S can be independently moved in the vertical direction by the moving mechanism 25. When forming a sheet bundle composed of a plurality of sheets, the lower end stopper 23 receives sheets sequentially fed into the sheet processing space S, and a plurality of sheets are stacked in the sheet processing space S. Then, with the lower end stopper 23 stopped, the upper end presser 24 lightly presses the upper end of the sheet bundle toward the lower end stopper 23 side, thereby aligning the upper end of the sheet bundle.

  Staple processing by the stapling device 26 is performed on the sheet bundle aligned as described above. The stapling devices 26 are arranged at two locations side by side in the paper width direction, that is, the paper surface depth direction in FIG. In the staple processing unit 20, by driving the moving mechanism 25, it is possible to perform stapling processing such as leading edge binding in which the staple is driven at the front end in the conveyance direction of the sheet bundle, and central binding in which staple is driven in the central portion in the conveyance direction of the sheet bundle. is there. When the stapling process is completed and the folding process is not performed, the sheet bundle is conveyed to the upper main discharge tray 6 by the moving mechanism 25, and when the folding process is performed, the sheet bundle is conveyed downward.

  The folding processing unit 30 is disposed on the downstream side of the staple processing unit 20 in the sheet conveyance direction, that is, below the staple processing unit 20 and at the lowermost part in the vertical direction of the sheet post-processing apparatus 1. The folding processing unit 30 is configured around a folding unit 40 that performs folding processing on the paper in a form that creases in the paper width direction perpendicular to the paper transport direction, and further stacks the paper after the folding processing is performed. A booklet discharge tray 31 serving as a paper discharge unit to be accommodated is provided. The sheet bundle subjected to the staple processing by the staple processing unit 20 is folded by the folding unit 40 and is discharged into the booklet discharge tray 31 as a booklet.

  Further, the sheet post-processing apparatus 1 is provided with a control unit 8 composed of a CPU 9 and other electronic parts not shown in the drawing as shown in FIG. The control unit 8 uses the CPU 9 as a central processing unit, and includes a punching device 2, a stapling processing unit 20, a folding processing unit 30, and other paper transport mechanisms based on programs and data stored and input in the storage unit 10. A series of paper post-processing operations are realized by controlling the elements. Note that the control unit 8 of the paper post-processing apparatus 1 performs punching, stapling, and folding on the paper discharged from the image forming apparatus 100 based on a control command received from the image forming apparatus control unit 101 of the image forming apparatus 100. Post-processing is performed.

  Next, the detailed configuration and operation of the bending processing unit 30 will be described with reference to FIGS. 3 to 5 in addition to FIGS. 1 and 2. 3 is a vertical sectional front view of the folding processing unit 30, FIG. 4 is a schematic perspective view of a rotation speed detection unit of the folding processing unit 30, and FIG. 5 is an explanatory view showing a predetermined full condition of the booklet discharge tray 31 of the folding processing unit 30. It is a table | surface which shows a paper discharge example. Note that the dotted arrows in FIG. 3 indicate the sheet conveyance path and conveyance direction.

  As shown in FIGS. 1 and 3, the folding processing unit 30 includes a paper stacking unit 32, a transport roller pair 33, a centering unit 50, a discharge unit, in addition to the above-described folding unit 40 and booklet discharge tray 31 that is a paper discharge unit. An outlet 34, a booklet presence / absence detection sensor 35, and a rotation speed detection unit 60 are provided.

  The paper stacking unit 32 is disposed in the folding processing unit 30 so as to be inclined slightly from the horizontal and extend downward in the paper transport direction. In the sheet stacking unit 32, a pair of conveying rollers 33, a bending unit 40, and a centering unit 50 are arranged in this order toward the downstream side. The folding unit 40 is provided in the center of the sheet stacking unit 32 in the sheet conveyance direction. The discharge port 34 is arranged at a point branched upward at the bent portion 40 with respect to the paper stacking portion 32 extending obliquely downward. The booklet discharge tray 31 is provided downstream of the discharge port 34 and includes a booklet presence / absence detection sensor 35 for detecting the presence / absence of a booklet.

  The conveyance roller pair 33 is disposed on the upstream side in the sheet conveyance direction with respect to the bending portion 40 disposed substantially at the center of the bending processing unit 30. The conveyance roller pair 33 is received from the staple processing unit 20 and conveys the sheet bundle sent to the conveyance nip formed by the pressure contact of the pair of rollers 33 a and 33 b toward the folding unit 40. The transport roller pair 33 can release the transport nip by moving the upper roller 33a upward.

  A conveyance roller pair 33 is used to convey the sheet fed from the staple processing unit 20 to the sheet stacking unit 32. At this time, the conveyance nip of the conveyance roller pair 33 is released immediately before the downstream end of the sheet comes into contact with a center alignment cursor 51 (to be described later) of the center alignment unit 50, and thereafter, the downstream end of the sheet is applied to the center alignment cursor 51 by inertia. Make contact.

  The center alignment part 50 is disposed downstream of the bent part 40. The center alignment unit 50 includes a center alignment cursor 51 and a moving mechanism 52.

  The center alignment cursor 51 is arranged on the paper stacking portion 32 and has a shape for receiving the downstream end of the paper bundle. The moving mechanism 52 includes an endless belt 53 that extends and rotates along the paper transport direction of the paper stacking unit 32. The center alignment cursor 51 is attached to the upper surface of the belt 53 and can be moved in the paper transport direction by the moving mechanism 52. As a result, the center aligning unit 50 moves the downstream end of the sheet bundle on the sheet stacking unit 32 so that the center of the sheet bundle in the sheet conveying direction coincides with a position of a folding blade 42 described later of the folding unit 40. Is displaced.

  The bending portion 40 is disposed downstream of the conveying roller pair 33 and upstream of the center aligning portion 50. The bending portion 40 includes a reciprocating mechanism 41, a bending blade 42, and a bending roller pair 43.

  The reciprocating mechanism 41 is disposed in the paper conveyance space of the paper stacking unit 32 having a shape slightly inclined from the horizontal and in a portion extending downward from the paper conveyance space. The reciprocating mechanism 41 includes a support member 41a that supports the bending blade 42 and a crank mechanism 41b. The reciprocating mechanism 41 changes the rotational power of a motor (not shown) into a linear motion by the action of the crank mechanism 41b, and reciprocates the support member 41a in a direction perpendicular to the paper stacking portion 32, that is, in the direction of the white arrow in FIG. Can be made.

  When the support member 41 a is moved to the lowermost position, the tip of the bending blade 42 is positioned below the sheet stacking portion 32. When the support member 41 a is moved to the uppermost position, the tip of the folding blade 42 protrudes further upward than the paper stacking portion 32 and reaches the conveyance nip portion of the folding roller pair 43.

  The bending roller pair 43 is disposed above the reciprocating mechanism 41. One roller 43a of the bending roller pair 43 rotates by obtaining power from the motor 44 (see FIG. 4), and the other roller 43b rotates in accordance with the rotation of the roller 43a by being in pressure contact with the roller 43a. The pair of bending rollers 43 forms a conveyance nip by pressing the pair of rollers 43a and 43b. However, the conveyance nip can be released by separating the roller 43b from the roller 43a.

  With the above configuration, the folding unit 40 pushes the paper on the paper stacking unit 32 upward by the folding blade 42 and sandwiches the paper in the conveyance nip of the folding roller pair 43, thereby forming a crease in the paper width direction perpendicular to the paper conveyance direction. Then, bend the paper. The sheet that has been subjected to the folding process in the folding unit 40 is conveyed toward the booklet discharge tray 31 using a pair of folding rollers 43.

  As shown in FIG. 3, the rotational speed detector 60 is provided at a location of the bending roller pair 43 and adjacent to the motor 44 that supplies power to the roller 43a (see FIG. 4). The rotational speed detector 60 includes a pulse plate 61 and an optical sensor 62.

  As shown in FIG. 4, the pulse plate 61 has a disk shape, and is fixed to the drive shaft 44 a so that the plane that is the rotation surface thereof is perpendicular to the axis of the drive shaft 44 a of the motor 44. The pulse plate 61 has a plurality of openings 61a provided at equal angular intervals in the circumferential direction. In FIG. 4, for convenience of drawing, only six openings 61a are drawn with the opening 61a omitted.

  The optical sensor 62 is disposed adjacent to a portion corresponding to the pulse plate 61. The optical sensor 62 is composed of, for example, a photo interrupter, and includes a light emitting unit 62a and a light receiving unit 62b facing each other, and a gap 62c is provided between them. In the optical sensor 62, the pulse plate 61 is inserted into the gap 62c, and the light is disposed at a position where the light can pass through the opening 61a of the pulse plate 61. Accordingly, when the motor 44 is rotated, the optical sensor 62 identifies that light emitted from the light emitting unit 62a is incident on the light receiving unit 62b intermittently, and transmits a pulse signal.

  A signal transmitted from the optical sensor 62 is sent to the control unit 8. The controller 8 detects the rotational speed of the motor 44 based on the output obtained from the optical sensor 62, that is, the rotational speed detector 60. In this way, the rotation speed detector 60 is used to detect the rotation speed of the motor 44.

  Then, the control unit 8 uses the output of the rotation speed of the motor 44 detected using the rotation speed detection unit 60 in order to determine whether the booklet discharge tray 31 is full. That is, the control unit 8 identifies that a rotational load has occurred on the motor 44 for transporting the sheet, which has been subjected to the folding process by the folding unit 40, toward the booklet discharge tray 31 using the folding roller pair 43. As a result, it is determined that the booklet discharge tray 31 is full and cannot be accommodated any more.

  For this reason, the storage unit 10 has a predetermined full condition for determining whether the booklet discharge tray 31 is full based on the rotational load generated in the motor 44 identified from the change in the rotational speed of the motor 44 during paper conveyance. Is stored in advance. The predetermined full condition is a threshold value related to the output value of the rotational speed detection unit 60, and whether the paper conveyance by the motor 44 is in a normal conveyance state or whether the rotation load of the motor 44 is higher than that in the normal conveyance state. , And condition data for determining that the booklet discharge tray 31 is full based on the number of occurrences of each conveyance state are stored.

  For example, as shown in FIG. 5, the threshold value of the output value of the rotation speed detection unit 60 is preset to 1000 pps (pulses / second) using a pulse signal obtained from the rotation speed detection unit 60 and is stored in the storage unit 10. Yes. If the rotational speed of the motor 44 is 1000 pps or more, it is regarded as a normal transport state, and if it is less than 1000 pps, it is regarded as a high load transport state in which the rotational load of the motor 44 is higher than that in the normal transport state.

  Further, for example, as condition data for determining that the booklet discharge tray 31 is full, the number of times the sheet is conveyed toward the booklet discharge tray 31 using the motor 44 is a predetermined number of times determined in advance from the first time. When the high-load conveyance state is detected three times before the first time, it is considered full, and when the high-load conveyance state is detected once between the fifth time and the tenth time that is a predetermined upper limit number Considering the capacity of the booklet discharge tray 31 to be full, and predetermining that it is full regardless of the transport state when reaching the upper limit of the 10th time and storing it in the storage unit 10 Yes.

  Thereby, as described in the discharge example 1 of the paper discharge example of FIG. 5, for example, when the high load transfer state is not detected even when the number of transfer of the sheet by the motor 44 is tenth, the capacity of the booklet discharge tray 31 is increased. Considered full.

  Further, for example, as described in the discharge examples 2 and 3, when the high-load conveyance state is detected three times from the first time to the fifth time, that is, during the first five times, it is considered full (black circle in the figure). When a booklet is created using paper that is relatively thicker or harder than normal plain paper, it is often considered full as in the discharge examples 2 and 3.

  Further, for example, as described in the discharge examples 4 to 6, when the high load conveyance state is detected once during the period from the fifth time to the tenth time, that is, the second half 5 times, it is considered full. When a booklet is created with ordinary plain paper, it is often considered full as in the discharge examples 4 to 6 due to the difference in the number of sheets in the sheet bundle forming the booklet. For example, as described in the discharge examples 7 and 8, when the high load conveyance state is detected up to 2 times in the first half 5 times, it is not considered full, but the high load conveyance in the latter half 5 times When the condition is detected, it is considered full.

  Note that the predetermined full condition for determining whether the booklet discharge tray 31 is full is not limited to the threshold value of the rotational speed or the condition data, and other conditions may be added or changed to other conditions. good. Further, the numerical values of the rotation speed and the number of conveyances used for the threshold value and the condition data are not limited to the above numerical values, and may be changed to other numerical values.

  Next, the operation relating to the fullness determination of the booklet discharge tray 31 will be described along the flow shown in FIG. 6 using the predetermined full condition in FIG. 5 as an example. FIG. 3 is a flowchart showing an operation relating to fullness determination of the booklet discharge tray 31.

  When the sheet post-processing apparatus 1 performs a folding process on the sheet in the folding processing unit 30 (start in FIG. 6), the control unit 8 starts detecting the booklet (paper) on the booklet discharge tray 31 after the booklet presence / absence detection sensor 35 starts detecting the booklet (paper). That is, it is determined whether or not the booklet discharge tray 31 is the eleventh time after the first booklet is discharged by the number of times of conveyance by the motor 44 (step # 101 in FIG. 6). If the number of booklets transported has not reached the eleventh time (No in Step # 101), the control unit 8 controls each component of the folding unit 40 to perform folding processing on the paper (Step # 102). When the number of booklet transports reaches the 11th time (Yes in step # 101), the control unit 8 determines that the booklet discharge tray 31 is full (step # 106).

  When the sheet that has been subjected to the folding process in the folding unit 40 is conveyed toward the booklet discharge tray 31 using the folding roller pair 43, the control unit 8 conveys the sheet based on the output obtained from the rotation speed detection unit 60. The rotational speed of the motor 44 at the time is detected (step # 103). Then, the control unit 8 determines whether or not the rotation speed of the motor 44 is less than a threshold value of 1000 pps (step # 104). When the rotation speed of the motor 44 is 1000 pps or more (No in Step # 104), that is, the paper is in the normal conveyance state, the process returns to Step # 101 to determine whether or not the next booklet is conveyed 11 times. .

  When the rotation speed of the motor 44 is less than 1000 pps (Yes in Step # 104), the control unit 8 determines whether or not the number of times of transport of the paper (booklet) being transported by the motor 44 has exceeded the fifth time at this time. (Step # 105). When the number of times of conveyance of the paper (booklet) being conveyed exceeds the fifth time (Yes in Step # 105), the control unit 8 identifies that the number of times that the rotation speed of the motor 44 is less than 1000 pps meets the condition data. Then, it is recognized that the predetermined full condition is satisfied, and it is determined that the booklet discharge tray 31 is full (step # 106).

  On the other hand, when the number of conveyances of the paper (booklet) being conveyed is between the first time and the fifth time (No in Step # 105), the controller 8 conveys the number of times that the rotation speed of the motor 44 is less than 1000 pps. It is determined whether it is the third time from the first time (step # 107). In this regard, the control unit 8 stores the number of times that the rotation speed of the motor 44 has become less than 1000 pps from the first time of sheet conveyance in the storage unit 10. If the number of times that the rotation speed of the motor 44 has become less than 1000 pps is less than 3 from the first time (No in Step # 107), return to Step # 101 and whether or not the number of times of transporting the next booklet is the 11th Determine whether.

  When the number of times that the rotation speed of the motor 44 has become less than 1000 pps is the third time from the first time in Step # 107 (Yes in Step # 107), the control unit 8 determines that the booklet discharge tray 31 is full ( Step # 106).

  After determining in step # 106 that the booklet discharge tray 31 is full, the control unit 8 causes the paper in the middle of the conveyance from the folding unit 40 to the booklet discharge tray 31 to be conveyed to the booklet discharge tray 31, and the folding unit 40 The paper folding process is stopped (step # 108). And the control part 8 complete | finishes the operation | movement which concerns on the fullness determination of the booklet discharge | emission tray 31 (end of FIG. 6).

  As described above, when the sheet post-processing apparatus 1 recognizes that the rotation speed of the motor 44 during sheet conveyance satisfies a predetermined full condition determined in advance based on the rotation speed of the motor 44, the booklet discharge tray 31 is full. It is determined that Therefore, since the sheet post-processing apparatus 1 determines whether the booklet discharge tray 31 is full by using the rotation speed of the motor 44, the booklet discharge is originally performed regardless of the bulge generated in the fold portion of the sheet or the number of sheets of the sheet bundle to be folded. It can be expected to store an amount of paper that can be stored in the tray 31. Since the rotational speed of the motor 44 may be detected in order to realize proper paper conveyance, it is not necessary to provide a dedicated paper upper limit detection sensor in order to detect whether the booklet discharge tray 31 is full.

  Further, the sheet post-processing apparatus 1 is in a high-load conveyance state in which the rotation speed of the motor 44 at the time of sheet conveyance obtained as an output value of the rotation speed detection unit 60 is less than a threshold, and the number of times the high-load conveyance state is entered is condition data. Is recognized as satisfying a predetermined full condition. Therefore, the sheet post-processing apparatus 1 determines whether the booklet discharge tray 31 is full based on the number of times the sheet conveyance by the motor 44 is in the high load conveyance state and the condition data set based on the number of times. It is possible to set a preferable predetermined full condition corresponding to the number of sheets (sheet bundle) and the sheet type. Thereby, it is possible to store more sheets in the booklet discharge tray 31.

  Further, the sheet post-processing apparatus can make detailed settings as to how full is detected as condition data for determining that the booklet discharge tray 31 is full.

  Further, even when it is determined that the booklet discharge tray 31 is full, the sheet post-processing apparatus 1 appropriately conveys the sheet that has been subjected to the folding process before the determination to the booklet discharge tray 31. As a result, the paper is accommodated in the booklet discharge tray 31 without causing a problem such as a jam in the middle of conveyance, so that even a single copy of a large amount of paper (booklet) can be accommodated in the booklet discharge tray 31. It is possible to continue the folding process smoothly.

  According to the configuration of the above embodiment, when the folded paper is discharged to the booklet discharge tray 31, the fullness of the booklet discharge tray 31 is determined using the rotational speed of the motor 44. The booklet discharge tray 31 has a simple configuration without providing an upper limit detection sensor, and accommodates as many sheets as possible in the booklet discharge tray 31 regardless of the number of sheets in the folds or the sheet bundle to be folded. Can be provided.

  Although the embodiments of the present invention have been described above, the scope of the present invention is not limited to these embodiments, and various modifications can be made without departing from the spirit of the invention.

  For example, in the above-described embodiment, the rotational speed detection unit 60 includes the pulse plate 61 having the opening 61a and the optical sensor 62 that allows light to pass through the opening 61a, and the control unit 8 has the opening 61a per unit time. Although the rotational speed of the motor 44 is detected by counting the light passing therethrough, the rotational speed of the motor 44 may be detected by other configurations and methods. For example, the rotational speed of the motor 44 may be detected using a current value flowing in the motor 44 whose level changes depending on the strength of the rotational load.

  Further, the sheet post-processing apparatus 1 may not include the punching device 2 and the staple processing unit 20.

  The present invention can be used in a sheet post-processing apparatus that performs a predetermined post-process such as a bending process on a sheet or the like supplied from an image forming apparatus.

DESCRIPTION OF SYMBOLS 1 Paper post-processing apparatus 2 Punch apparatus 8 Control part 10 Storage part 20 Staple processing unit 30 Bending processing unit 31 Booklet discharge tray (paper discharge part)
DESCRIPTION OF SYMBOLS 40 Bending part 43 Bending roller pair 44 Motor 60 Rotational speed detection part 61 Pulse plate 62 Optical sensor 100 Image forming apparatus

Claims (5)

A folding section that performs folding processing in a form that creases the paper;
A paper discharge section for stacking and storing sheets after being folded in the bending section;
A motor for transporting the paper after being subjected to the bending process in the bending section toward the paper discharge section;
A rotational speed detector for detecting the rotational speed of the motor;
A storage unit for storing a predetermined full condition for determining whether the paper discharge unit is full based on a rotational load generated in the motor identified from a change in rotational speed of the motor during paper conveyance;
The rotation speed of the motor is detected based on the output obtained from the rotation speed detection section every time the sheet after the folding process is performed in the bending section, and the rotation speed of the motor is stored in the storage section. A control unit that determines that the paper discharge unit is full when the predetermined full condition is satisfied;
A sheet post-processing apparatus comprising: The storage unit is a threshold value related to the output value of the rotation speed detection unit, and is the sheet transported by the motor in a normal transport state or is the high load transport state in which the rotational load of the motor is higher than the normal transport state? And a condition data for determining that the paper discharge unit is full based on the number of occurrences of each conveyance state, and storing as the predetermined full condition,
The control unit is configured such that the rotation load of the motor is in the normal conveyance state based on the output obtained from the rotation speed detection unit and the threshold value every time the sheet after the folding process is performed by the bending unit is conveyed. 2. The sheet post-processing apparatus according to claim 1, wherein the sheet post-processing apparatus recognizes that the predetermined full condition is satisfied when it is detected whether it is in the high-load conveyance state or when it is matched with the condition data. .   The storage unit determines that the number of times the high-load conveyance state is detected between the first time and a predetermined number of times as to the number of times the sheet is conveyed toward the sheet discharge unit using the motor. Information on how many times the high-load transport state is detected between the predetermined number of times and a predetermined upper limit number of times, and a transport state when the upper limit number is reached The sheet post-processing apparatus according to claim 2, wherein the condition data is stored as information indicating that it is full regardless of the condition data.   When the control unit determines that the sheet discharge unit is full, the control unit causes the sheet in the middle of conveyance from the folding unit to the sheet discharge unit to be conveyed to the sheet discharge unit, and bends the sheet by the folding unit. The paper post-processing apparatus according to any one of claims 1 to 3, wherein the processing is stopped. The rotational speed detector is
An optical sensor having a light emitting part and a light receiving part;
A pulse plate having an opening through which the light of the optical sensor passes,
5. The sheet according to claim 1, wherein the control unit detects the rotation speed of the motor by counting light passing through the opening per unit time. 6. Post-processing device.

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