JP2014105107A - Sheet processing device and image formation system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a sheet processing device capable of preventing a processing failure resulting from a voltage drop between a power supply and a sheet processing unit while preventing a drive source from being damaged by overcurrent.SOLUTION: A sheet processing device includes: current detection means for detecting a drive current flowing in a drive source; voltage detection means for detecting a drive voltage applied to the drive source; current limiting means for limiting the drive current detected by the current detection means so as not to exceed a predetermined limited current value; and control means for changing the limited current value on the basis of a detected value of the drive voltage detected by the voltage detection means.

Description

  The present invention relates to a sheet processing apparatus that processes sheets and an image forming system including the sheet processing apparatus.

  2. Description of the Related Art Conventionally, as this type of sheet processing apparatus, a sheet post-processing apparatus that aligns sheets output from an image forming apparatus and performs binding processing with a stapler or punching processing with a punch is known. In this paper processing apparatus, a paper processing unit such as a stapler or punch for processing paper is driven by a motor as a drive source. When a paper processing unit such as a stapler or punch is driven by a motor in this way, if a load greater than the load assumed in the paper processing unit is applied, an overcurrent may flow through the motor and the motor may be burned. Further, when an overcurrent prevention circuit for preventing an overcurrent flowing through the motor is provided, the motor may stop during paper processing. In view of this, a sheet processing apparatus that drives a motor by limiting the current flowing through the motor to a predetermined value or less is known (see, for example, Patent Document 1).

  However, in the conventional paper processing apparatus as disclosed in Patent Document 1, there is a risk that a relatively large voltage drop occurs in the power supply circuit from the power source to the drive source (motor). When the voltage drop occurs, the voltage applied to the drive source (motor) that operates the stapler and the punch decreases, and the motor torque decreases. For example, when binding processing is performed with a stapler in a state where the motor torque is reduced, there is a possibility that a binding failure in which the staple cannot penetrate the paper may occur depending on the paper type and paper thickness. Further, when punching is performed in a state where the motor torque is reduced, there is a possibility that poor drilling may occur. Such processing failures such as binding failures and punching failures tend to occur particularly when a large number of thick sheets are bound or punched (punched).

  In addition, driving power for driving a paper processing unit having a stapler, a punch, or the like with respect to paper output from the image forming apparatus is normally supplied from a paper supply apparatus such as an image forming apparatus that supplies paper to be processed. Is done. In particular, in a paper processing apparatus capable of high-speed processing, a plurality of paper processing apparatuses are often connected to the image forming apparatus, and wiring from the image forming apparatus to peripheral devices such as a paper processing apparatus on the most downstream side in the paper transport direction is provided. Tend to be longer. For this reason, depending on the system configuration, a voltage drop in the power supply circuit from the power supply of the paper supply device to the drive source (motor) in the paper processing device may occur due to the resistance of the wiring and the operating state of other paper processing devices. End up. This voltage drop tends to increase particularly when a large current is required, such as during binding processing or punching processing in the paper processing apparatus. Even in a paper processing apparatus having a lower processing speed than a paper processing apparatus capable of high-speed processing, a voltage drop may occur due to a current detection resistor or a switching transistor in a power supply circuit of the paper supply apparatus.

  The present invention has been made in view of the above problems, and an object of the present invention is to prevent a processing failure caused by a voltage drop between a power source and a paper processing unit while preventing a drive source from being damaged by an overcurrent. It is an object of the present invention to provide a paper processing apparatus that can perform the above processing.

  In order to achieve the above object, the invention of claim 1 is a sheet processing apparatus comprising a drive source and a sheet processing unit that processes a sheet using the driving force of the drive source, wherein the drive source Current detection means for detecting the drive current flowing through the current source, voltage detection means for detecting the drive voltage applied to the drive source, and the drive current detected by the current detection means so as not to exceed a predetermined limit current value And a control means for changing the limit current value based on the detected value of the drive voltage detected by the voltage detection means.

  According to the present invention, it is possible to prevent damage to the drive source due to overcurrent by limiting the drive current detected by the current detection means so as not to exceed a predetermined limit current value. Further, based on the detected value of the driving voltage detected by the voltage detecting means, it can be determined whether or not the voltage drop between the power source and the sheet processing unit has increased and the driving voltage has decreased below a predetermined value. When it is determined that the voltage drop between the power source and the paper processing unit has increased and the drive voltage has fallen below a predetermined value, the limit current value is changed to be larger, and the voltage drop has occurred. However, it is possible to apply a driving voltage of a predetermined magnitude or more to the driving source. Thereby, it is possible to prevent a processing failure in the paper processing unit due to the voltage drop. As described above, according to the present invention, it is possible to prevent a processing failure caused by a voltage drop between the power source and the paper processing unit while preventing damage to the drive source due to overcurrent.

1 is a schematic configuration diagram illustrating an overall configuration of an image forming system in which a sheet processing apparatus according to an embodiment of the present invention is connected to an image forming apparatus. FIG. 3 is a schematic configuration diagram enlarging a main part of the sheet processing apparatus, and an operation explanatory diagram when performing edge binding. Explanatory drawing of operation | movement which switches back a sheet | seat for edge binding. Explanatory drawing of operation | movement which abuts and aligns a paper rear end with a reference | standard fence with a return roller in order to end-stitch. FIG. 9 is an operation explanatory diagram of a stapler that binds the aligned sheet bundle. FIG. 9 is an operation explanatory diagram for discharging the edge-bound paper bundle to a paper discharge tray. Operation | movement explanatory drawing at the time of saddle stitching. Explanatory drawing of operation | movement which switches back a sheet | seat for saddle stitching. Explanatory drawing of operation | movement which abuts and aligns a paper rear end against a reference fence with a return roller for saddle stitching. FIG. 9 is an operation explanatory diagram illustrating a state in which the sheet bundle is aligned for saddle stitching. Explanatory drawing of operation | movement which retracts | saves a reference fence and conveys a sheet bundle to a saddle stitching position. FIG. 5 is an operation explanatory diagram of a stapler that performs saddle stitching on an intermediate portion of a sheet bundle with a staple. Explanatory drawing of operation | movement which conveys the saddle-stitched sheet bundle to a center folding unit. The external perspective view of a separation type stapler. The schematic block diagram of a stapler. FIG. 6 is an operation explanatory diagram illustrating a state in which the clinch portion of the clincher is lowered to sandwich the sheet bundle. FIG. 6 is an operation explanatory diagram for passing a staple needle through a sheet bundle. Operation | movement explanatory drawing which bends a staple with the needle | hook bending mechanism in a clinching part. Operation | movement explanatory drawing of the operation | movement which returns a clinching part and a braid | blade to a home position. The circuit diagram which shows an example of the motor drive circuit of DC motor. The circuit diagram of an example which controls the reference voltage Vref2 using the D / A output of a control part. The circuit diagram of an example of the detection circuit which detects the voltage drop of the power supply voltage V using the A / D converter of a control part. The graph which shows an example of a staple control signal and a voltage current waveform. 6 is a flowchart illustrating an example of stapler control. 6 is a flowchart illustrating an example of stapler control in consideration of the number of sheets bundled. 6 is a flowchart showing a procedure for performing control for raising a limit current value based on sheet number information and sheet thickness information acquired from the image forming apparatus. FIG. 3 is a block diagram illustrating an example of a control device of a sheet processing apparatus.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
FIG. 1 is a schematic configuration diagram showing an overall configuration of an image forming system in which a sheet processing apparatus according to an embodiment of the present invention is connected to an image forming apparatus. FIGS. 2 to 6 are schematic configuration diagrams enlarging the main part of the sheet processing apparatus, and are diagrams for explaining the operation of the stapler as the sheet processing unit in the end binding mode in which the end of the sheet bundle is bound by the staple needle. It is.

  In FIG. 1, an image forming apparatus 700 may form an image composed of a toner image on a sheet by an electrophotographic method, or may form an image by another method such as an ink jet method. The image forming apparatus 700 also functions as a paper supply apparatus that supplies paper to be processed by the paper processing apparatus 100.

  As shown in FIG. 1, the sheet processing apparatus 100 includes an introduction path 1 for receiving the image-formed sheet P discharged from the image forming apparatus 700 and a proof conveyance path 2 for discharging the sheet P to the proof tray 110. I have. In addition, the paper processing apparatus 100 includes a transport path 3 for transporting the paper P to the paper discharge tray 111, a stapler 210 as a binding processing unit as a paper processing unit, and a paper punching unit as a punching processing unit as a paper processing unit. (Hereinafter referred to as “punch unit”) 120. The stapler 210 binds the bundle of sheets aligned by the staple alignment tray 202 that stacks and aligns the sheets P. The punch unit 120 opens a hole in the paper P. Further, the paper processing apparatus 100 includes a middle folding unit 300 as a middle folding processing unit that is a paper processing unit for folding the paper P.

  An inlet roller 101 and an inlet sensor 130 are disposed in the introduction path 1, and the inlet sensor 130 detects that the paper P has been carried into the paper processing apparatus 100. A punch unit 120 is disposed downstream of the entrance roller 101, and a transport roller (sending part) 102 is disposed downstream of the entrance roller 101. The transport roller 102 transports the paper P to the proof transport path 2 or the transport path 3. Is done. Switching of the sheet conveyance path to the proof conveyance path 2 or the conveyance path 3 is performed by the branching claw 103. The proof conveyance path 2 includes conveyance rollers 104 and 105, and discharges the paper P to the proof tray 110.

  In the conveyance path 3, a hitting roller (alignment means) 201, a paper discharge roller (paper discharge means) 107, and a paper discharge sensor 131 are arranged. In the shift mode, the shift roller 106, which is a transport roller having a shift mechanism, is moved by a fixed amount in a direction perpendicular to the transport direction by a driving unit (not shown). As a result, the paper P being conveyed is shifted by a certain amount and discharged to a paper discharge tray 111 that can be moved up and down by the paper discharge rollers 107a and 107b. The sheets P discharged by the discharge rollers 107a and 107b are sequentially stacked on the discharge tray 111.

  The discharge port to the discharge tray 111 has a pair structure in which a sheet or sheet bundle is sandwiched and discharged by a discharge roller 107b and a driven roller (discharge unit) 107a. This is because the driven roller 107a is brought into and out of contact with the paper discharge roller 107b so that a closed state in which the paper or the paper bundle can be pinched and discharged and an open state in which the paper or paper bundle is not pinched can be selectively taken. The paper shift operation is completed in the open state, and then the paper is closed and the paper is nipped and discharged.

  As shown in FIG. 2, a staple alignment tray 202 and a bundle conveying roller 301 that can be moved toward and away from each other are arranged in the conveying path 3. In addition, a stapler 210 divided into a driver and a clincher that advance and retreat in a direction orthogonal to the paper surface is provided at the end position of the staple alignment tray 202. In addition, a pair of opposing jogger fences 203 and the like are provided that align the sheets on the staple aligning tray 202 by advancing and retreating in a direction orthogonal to the sheet surface.

  The sheet transported to the transport path 3 is discharged onto the staple alignment tray 202 and aligned with the position in the width direction by the jogger fence 203. Further, the hitting roller 201 performs a pendulum motion to contact the upper surface of the paper to switch back the paper in the direction of the stapler 210 (see FIG. 3), and further, the back roller 204 abuts the rear edge of the paper against the reference fence 205. (See FIG. 4). By this abutting operation, the position (deviation) of the sheet bundle in the vertical direction (conveyance direction) is aligned.

  In the end binding mode, the stapled sheet 210 moves in a direction perpendicular to the paper surface and the stapled sheet bundle is bound by a staple at a suitable position at the lower edge of the bundle of sheets (see FIG. 5). . The paper is then ejected onto the paper ejection tray 111 by being sandwiched between the paper ejection roller 107b and the driven roller 107a (see FIG. 6).

  In the saddle stitching mode, after the alignment of the sheet bundle is completed on the staple aligning tray 202, the sheet bundle is sandwiched by the bundle conveyance roller 301, and the reference fence 205 is arranged on the sheet conveyance path so as not to obstruct the sheet bundle conveyance. Retreat outward (see FIG. 11). Next, the sheet bundle is conveyed to a predetermined position by the bundle conveying roller 301 so that the middle portion of the sheet bundle comes to the staple binding position 210a, and the stapler 210 is used to bind the middle portion of the sheet bundle to the middle position. Binding is performed (see FIG. 12).

  The staple saddle stitching tray 350 and the upper guide plate 351 are structured to bend downward at the center, and are parallel to the staple alignment tray 202 until the sheet bundle is saddle stitched. When the saddle stitching of the sheet bundle is completed, the staple saddle stitching tray 350 and the upper guide plate 351 are bent downward at the center so that the sheet bundle can be conveyed into the folding unit 300. As shown in FIG. 13, the saddle-stitched sheet bundle is conveyed by a bundle conveying roller 301 and further conveyed into the middle folding unit 300 by a bundle conveying roller (lower) 302 of the middle folding unit 300. Then, the sheet is folded by a sheet folding blade 304 and a sheet folding roller 303, and the folded sheet bundle is discharged onto a saddle stitching tray 112 by a sheet discharge roller 305.

  In addition, a punch unit 120 that performs punching processing on a bundle of sheets is detachably mounted in the main body of the sheet processing apparatus 100 of the present embodiment. By configuring the punch unit 120 to be detachable, it is possible to provide a paper processing apparatus that omits the punch unit 120 according to the needs of the user. When punching the paper P, the punching pin 120a is moved up and down using a motor and a cam to punch the paper P.

Next, the operation of the edge binding stapling process of the sheet processing apparatus 100 will be described in more detail.
As shown in FIG. 2, the sheet P conveyed to the conveyance path 3 passes through the shift roller 106 and is then discharged onto the staple alignment tray 202. Then, as shown in FIG. 3, the tapping roller 201 descends and comes into contact with the upper surface of the paper, thereby switching the paper back toward the stapler 210. Further, as shown in FIG. 4, the rear end of the sheet is abutted against the reference fence 205 by the return roller 204. By this abutting operation, the position (deviation) of the sheet bundle in the vertical direction (conveyance direction) is aligned. Next, it is aligned with the position in the width direction by the jogger fence 203. The tapping roller 201 rises to accept the next paper, and the next paper performs the same process. In this way, a sheet bundle Pt is formed.

  The sheet bundle Pt aligned in this manner is bound by binding the appropriate position at the lower edge of the sheet bundle by moving the stapler 210 in the direction perpendicular to the sheet surface in the edge binding mode as shown in FIG. After that, as shown in FIG. 6, the paper is ejected onto the paper ejection tray 111 by being sandwiched between the paper ejection roller 107 b and the driven roller 107 a. Since the staple binding position 210a is located at the end binding position, the bundle transport roller 301 does not transport the bundle in the end binding mode.

  Next, the saddle stitching stapling operation in which the sheet processing apparatus 100 binds the intermediate portion between the leading end and the trailing end with the staple S in the conveyance direction of the sheet P will be described in more detail.

7 to 13 are operation explanatory views for explaining the operation of the saddle stitching staple.
As shown in FIG. 7, the paper P that has been transported to the transport path 3 passes through the shift roller 106 and is then discharged onto the staple alignment tray 202. Then, as shown in FIG. 8, the tapping roller 201 descends and comes into contact with the upper surface of the paper, thereby switching the paper back toward the stapler 210. Further, as shown in FIG. 9, the rear end of the sheet is abutted against the reference fence 205 by the return roller 204. By this abutting operation, the position (deviation) of the sheet bundle in the vertical direction (conveyance direction) is aligned. Next, it is aligned with the position in the width direction by the jogger fence 203. The tapping roller 201 rises to accept the next paper, and the next paper performs the same process. In this way, a sheet bundle Pt is formed as shown in FIG.

  The sheet bundle Pt aligned in this way is sandwiched between bundle conveying rollers 301 as shown in FIG. 11, and the reference fence 205 is retracted to the outside of the sheet conveying path so as not to interfere with the sheet bundle conveyance. Next, as shown in FIG. 12, the sheet bundle Pt is conveyed to a predetermined position by the bundle conveying roller 301 so that the middle portion of the sheet bundle comes to the staple binding position 210a, and is bound by the stapler 210. Is done.

  As shown in FIG. 13, the saddle stitched sheet bundle Pt is conveyed by the bundle conveying roller 301, and further conveyed into the middle folding unit 300 by the bundle conveying roller (lower) 302 of the middle folding unit 300. Then, the sheet folding blade 304 and the sheet folding roller 303 are folded in half, and the folded sheet bundle is discharged onto the saddle stitching tray 112 by the sheet discharge roller 305 (see FIG. 1).

Next, the mechanism of the stapler 210 mounted on the paper processing apparatus 100 will be described in more detail.
FIG. 14 is an external perspective view of the separation type stapler 210, and FIGS. 15 to 19 are operation explanatory views showing the operation of the stapler 210 in a simplified manner.

  As shown in FIG. 14, the stapler 210 has a vertically separated structure, with the clincher C on the upper side and the driver D on the lower side. The mechanism of the driver D is driven by a DC motor M1 as a drive source inside the driver as shown in FIG. 15, and the mechanism of the clincher C is driven by a DC motor M2 as a drive source.

  In order to bind the sheet bundle Pt with the staples S, first, the clinch portion 210c of the clincher C is lowered to sandwich the sheet bundle Pt as shown in FIG. The clinching part 210c is driven by a DC motor M2 with a gear or a cam (not shown). Next, as shown in FIG. 17, the staples S in the cartridge 210b bent in advance in a U-shape are passed through the sheet bundle Pt by the blade 210d. The blade 210d is driven by a DC motor M1 with a gear or a cam (not shown). When the staple needle S is completely penetrated, the staple needle S is bent by the needle bending mechanism in the clinch portion 210c as shown in FIG. When the needle bending is completed, as shown in FIG. 19, the clinch portion 210c and the blade 210d are returned to the home position to complete the operation.

FIG. 20 is a circuit diagram showing an example of a motor drive circuit for driving a DC motor.
As shown in FIG. 20, the drive circuit of the DC motor is generally driven by an H bridge circuit composed of four transistors 502, 503, 504, and 505. When the transistor 502 and the transistor 505 are turned on, the motor M rotates. When the transistor 503 and the transistor 504 are turned on, the current of the motor M is reversed, so that the motor M rotates in the reverse direction. Further, when the transistor 504 and the transistor 505 are turned on, a loop circuit is formed in the motor M, and a short brake operation is performed. Note that the wirings of the gate terminals of the transistors 502, 503, 504, and 505 and the driver controller 508 as drive source drive control means are not shown.

  The transistor is controlled by a driver controller 508 in the driver IC 507. The driver controller 508 is connected to a control unit 500 as control means, and the motor M is controlled as shown in Table 1 by signals IN1 and IN2 from the control unit 500, for example.

  The control unit 500 is configured by hardware such as a CPU, a RAM, a ROM, and an I / O interface, for example, and controls and controls each unit by reading and executing a predetermined control program. And send / receive signals. Note that a part or the whole of the control unit 500 may be configured by an electronic circuit element (electronic component) such as an ASIC (Application Specific Integrated Circuit) or a programmable logic device configured to realize a predetermined function. Further, a part or the whole of the control unit 500 may be configured by an electronic circuit element (electronic component) such as an FPGA (Field-Programmable Gate Array). The control unit 500 functions as all or part of each of the current detection unit, the voltage detection unit, and the current control unit.

  A voltage drop occurs in the drive voltage V supplied to the motor M due to the impedance r of the power supply circuit. The impedance r is an internal impedance of the power supply device itself, a wiring resistance, a switch resistance, or the like. The driving voltage V ′ dropped due to the impedance r is detected by the comparator 506. Here, the lower limit level of the detection voltage can be arbitrarily set by the voltage Vref1. Depending on the value of the voltage Vref1, it is possible to set how much the current limit value is raised when the power supply voltage is lowered. The power source used in the sheet processing apparatus 100 of the present embodiment is a DC power supply, and may be provided in the main body of the sheet processing apparatus 100 or may be configured to be supplied with power from the image forming apparatus 700.

  The resistor Rs is a resistor for detecting the motor current. The motor current is measured by detecting the voltage applied to the resistor Rs. The measured voltage is compared with the reference voltage Vref2 by the comparator 501. The reference voltage Vref2 is generated by resistance division of the resistors R1 and R2. Further, the voltage changes depending on the output of the resistor R3 and the comparator 506. When the output of the comparator 506 is H, the reference voltage Vref2 increases and the limit current value increases. When the output of the comparator 506 is L, the reference voltage Vref2 decreases and the limit current value decreases. When the motor current reaches the reference value, the driver controller 508 controls the transistors 502, 503, 504, and 505 so that the motor current becomes constant.

  FIG. 21 is a circuit diagram illustrating an example of controlling the reference voltage Vref2 using the D / A output of the control unit 500. In this case, the output of the comparator 506 is input to the control unit 500, and the reference voltage Vref2 is varied according to the determination of the control unit 500. Since control is performed by the controller 500, the reference voltage Vref2 can be varied in conjunction with the timing of the control signals IN1 and IN2. Therefore, the limit current value can be changed only at a specific drive timing.

  FIG. 22 shows an example in which the voltage drop of the power supply V is detected using the A / D converter of the control unit 500. By monitoring the voltage drop amount by the A / D converter, the voltage drop can be detected in multiple stages, and the amount of increase in the limit current value of the motor current can be controlled in multiple stages accordingly.

  The image forming apparatus 700 and the control unit 500 exchange information such as the paper type and the number of sheets through a communication circuit. Since the number of sheets and the sheet thickness can be grasped in advance, it is possible to predict in advance how much the load on the stapler 210 and the punch unit 120 will be. When the load is predicted to be large, the limit current value at the time of voltage drop occurrence is set to be larger than usual, thereby further reducing stapling defects and punch punching defects.

FIG. 23 is a graph showing an example of a staple control signal and a voltage / current waveform. FIG. 24 is a flowchart showing an example of control of the stapler 210.
In FIG. 24, when the stapling process is started, the paper P is first aligned (S101). Then, the DC motor M2 on the clincher side of the stapler 210 is activated (S102). The rotation of the clincher-side DC motor M2 is detected by the clincher encoder sensor (clincher ENC signal), and when the DC motor M2 is rotated by a predetermined amount, the driver-side DC motor M1 is activated (S103).

  Further, when the DC motor M1 on the clincher side has rotated a specified amount, it is stopped (S104). Thereafter, when the driver side staple S passes through the sheet bundle Pt, the load increases, so that the current amount of the DC motor M1 on the driver side increases (binding process in FIG. 23). At this time, if the supply voltage supplied to the DC motor M1 on the driver side decreases, there is a possibility that a binding failure due to insufficient torque may occur when the number of sheets bundle Pt is large. For this reason, in the stapler 210 of this embodiment, when there is a voltage drop, control is performed to increase the limit current value only in the binding process portion. In order to increase the limit current value only in the binding process portion, after the driver-side DC motor M1 is started (S103), control is performed to stop the clincher-side motor M2 (S104), and then the motor voltage of the DC motor M1 is detected. (S105). If the motor voltage is less than or equal to the specified value (Y in S105), the reference voltage Vref2 of the DC motor M1 on the driver side is raised to raise the limit current value (S106). On the other hand, when there is no voltage drop (N in S105), the reference voltage Vref2 is maintained without being raised.

Then, when the driver-side DC motor M1 rotates a predetermined amount, the staple S passes through the sheet bundle Pt (S107), and the clincher-side DC motor M2 is rotated again (S108). Then, the portion that penetrates the sheet bundle Pt of the staple needle S is bent by the clincher C, and the binding is completed (S109). If the reference voltage Vref2 of the DC motor M1 on the driver side has been raised in S106, the reference voltage Vref2 is lowered by the stop control of the DC motor M1, and the limit current value is lowered and restored (S110).
Thereafter, both the DC motors M1 and M2 on the driver side and the clincher side are rotated, and the motors are rotated until the respective home position sensors (driver HP and clincher HP in FIG. 23) are turned on (L). S111). Then, the mechanism of the driver D and the clincher C is returned to the home position and stopped (S112). Then, the sheet bundle Pt for which the stapling process is completed is discharged to the discharge tray 111 (S113).

  Here, the magnitude of the limit current value of the DC motor M1 on the driver side may be varied depending on the number of sheets P bound by the staples at a time.

FIG. 25 is a flowchart showing an example of control of the stapler 210 in consideration of the number of sheets.
When the stapling process is started in FIG. 25, the sheet P is detected by the entrance sensor 130 as the sheet detecting unit, and the control unit 500 as the sheet number counting unit counts the number of sheets to be stapled at one time (S201). The sheets P are aligned (S202). Then, it is determined whether or not there is a next sheet P (S203). If there is, the counting of the number of sheets and matching are repeated (Y in S203, S201, 202). On the other hand, if there is no next sheet P (N in S203), the DC motor M2 on the clincher side of the stapler 210 is activated (S204). The rotation of the DC motor M2 on the clincher side is detected by the clincher encoder sensor (clincher ENC signal), and the DC motor M1 on the driver side is activated when the DC motor M2 rotates a specified amount (S205). Further, when the DC motor M1 on the clincher side has rotated a specified amount, it is stopped (S206).

  Next, in order to determine whether or not there is a voltage drop in the supply voltage of the DC motor M1 on the driver side, it is detected whether or not the motor voltage is below a specified value (S207). If the motor voltage is less than or equal to the specified value (Y in S207), control is performed to raise the reference current Vref2 of the DC motor M1 and raise the limit current value.

  Here, control is performed to vary the limit current value according to the number of sheets P to be stapled at a time. That is, it is determined whether or not the number of sheets P counted in S201 is equal to or greater than a predetermined number X (S208). If the number of sheets P is less than the prescribed number X (N in S208), the reference voltage Vref2 of the DC motor M1 on the driver side is increased to the limit current value A (S209). On the other hand, if the number of sheets P is equal to or greater than the specified number X (Y in S208), the reference voltage Vref2 of the DC motor M1 on the driver side is raised to the limit current value B (S210). Here, the limiting current value is set so as to satisfy the relationship of limiting current value A <limiting current value B.

In step S207, it is determined whether or not the motor voltage has dropped, and if there is a voltage drop, the limit current value is raised and the sheet bundle Pt is stapled. Specifically, when the DC motor M1 on the driver side rotates a specified amount, the staple S passes through the sheet bundle Pt (S211), and the DC motor M2 on the clincher side is rotated again (S212). Then, the portion that penetrates the sheet bundle Pt of the staple needle S is bent by the clincher C, and the binding is completed (S213). If the reference voltage Vref2 of the DC motor M1 on the driver side is increased in S209 or S210, the reference voltage Vref2 is decreased by the stop control of the DC motor M1, and the limit current value is decreased and returned (S214). ).
Thereafter, both the DC motors M1 and M2 on the driver side and the clincher side are rotated, and the motors are rotated until the respective home position sensors (driver HP and clincher HP in FIG. 23) are turned on (L). S215). Then, the mechanism of the driver D and the clincher C is returned to the home position and stopped (S216). Then, the sheet bundle Pt for which the stapling process has been completed is discharged to the discharge tray 111 (S217).

  According to the sheet processing apparatus 100 of the present embodiment, even if the user erroneously inputs the number of sheets P, the number of sheets P is actually counted, and therefore based on the counted number of sheets P. Thus, the current limit value can be controlled. Therefore, when the user makes an error in inputting the number of sheets, a control error such as increasing the limit current value when control is not required or conversely not increasing the limit current value when control is required. Can be prevented.

  Further, the number of sheets information and the sheet thickness information may be acquired from the image forming apparatus 700 using a communication unit, and the limit current value of the DC motor M1 may be increased based on the information. .

  FIG. 26 is a flowchart showing a procedure for performing control to raise the limit current value based on the sheet number information and sheet thickness information acquired from the image forming apparatus 700.

In FIG. 26, when the stapling process is started, the paper P is first aligned (S301). Thereafter, sheet number information and sheet thickness information are acquired from the image forming apparatus 700 using a communication unit (not shown) (S302). As the communication means, an appropriate communication method such as a wired communication method or a wireless communication method can be used.
Then, the DC motor M2 on the clincher side of the stapler 210 is activated (S303). The rotation of the DC motor M2 on the clincher side is detected by the clincher encoder sensor (clincher ENC signal), and when the DC motor M2 rotates a predetermined amount, the DC motor M1 on the driver side is activated (S304). Further, when the DC motor M1 on the clincher side has rotated a specified amount, it is stopped (S305).

  Next, in order to determine whether or not there is a voltage drop in the supply voltage of the DC motor M1 on the driver side, it is detected whether or not the motor voltage is below a specified value (S306). If the motor voltage is less than or equal to the specified value (Y in S306), control is performed to increase the reference voltage Vref2 of the DC motor M1 and raise the limit current value.

  Here, control is performed so that the limit current value varies according to the number of sheets P to be stapled at a time and the thickness of the sheets. That is, it is determined whether or not the number of sheets P acquired from the image forming apparatus 700 in S302 is equal to or greater than a predetermined number X (S307). If the number of sheets P is less than the prescribed number X (N in S307), the reference voltage Vref2 of the DC motor M1 on the driver side is raised to the limit current value A (S308). On the other hand, if the number of sheets P is equal to or greater than the prescribed number X (Y in S307), it is further determined whether or not the thickness of the sheet P is equal to or greater than Y (S309). If the thickness of the paper P is less than Y (N in S309), the reference voltage Vref2 of the DC motor M1 on the driver side is increased to the limit current value B (S310). On the other hand, if the thickness of the paper P is equal to or greater than Y (Y in S309), the load is expected to increase further. Therefore, the reference voltage Vref2 of the DC motor M1 on the driver side is increased to limit the current limit value. Pull up to C (S311). Here, the limit current value is set so as to satisfy the relationship of limit current value A <limit current value B <limit current value C.

In S306, it is determined whether or not the motor voltage has dropped. If there is a voltage drop, the limit current value is raised and the sheet bundle Pt is bound. Specifically, when the driver-side DC motor M1 rotates a specified amount, the staple S passes through the sheet bundle Pt (S312), and the clincher-side DC motor M2 is rotated again (S313). Then, the portion that penetrates the sheet bundle Pt of the staple needle S is bent by the clincher C, and the binding is completed (S314). If the reference voltage Vref2 of the DC motor M1 on the driver side is increased in S308, 310, and 311 above, the reference voltage Vref2 is decreased by the stop control of the DC motor M1, and the limit current value is decreased and returned to the original value. (S315).
Thereafter, both the DC motors M1 and M2 on the driver side and the clincher side are rotated, and the motors are rotated until the respective home position sensors (driver HP and clincher HP in FIG. 23) are turned on (L). S316). Then, the mechanism of the driver D and the clincher C is returned to the home position and stopped (S317). Then, the sheet bundle Pt for which the stapling process has been completed is discharged to the discharge tray 111 (S318).

  Note that the control example shown in the flowchart of FIG. 26 is an example, and more judgment conditions are set for the number and thickness of the sheets P to increase the number of limit current values used for the control, and more detailed steps. It may be configured to perform such control.

FIG. 27 is a block diagram illustrating an example of a control device of the sheet processing apparatus 100.
In FIG. 27, an image forming apparatus 700, an entrance sensor 130, a paper discharge sensor 131, various motors, a middle folding unit 300, and the like are electrically connected to the control unit 500. The control unit 500 receives information such as the paper type and the number of sheets received from the image forming apparatus 700 and signals from the inlet sensor 130, the paper discharge sensor 131, and other sensors in the paper processing apparatus 100. Based on these received signals, the motor, the stapler 210, the punch unit 120, the half-folding unit 300, and the like in the paper processing apparatus 100 are controlled to appropriately process the paper P in a predetermined procedure.

What has been described above is merely an example, and the present invention has a specific effect for each of the following modes.
(Aspect A)
A driving source such as DC motors M1 and M2 and a sheet processing unit such as a punch unit 120 and a stapler 210 that process the sheet P using the driving force of the driving source with respect to the sheet P on which an image is formed are provided. The paper processing apparatus 100 includes a current detection unit such as a current detection resistor Rs and a comparator 501 that detects a drive current flowing through the drive source, and a voltage detection unit such as a comparator 506 that detects a drive voltage applied to the drive source. Current limiting means such as a control unit 500, a comparator 501, and a driver controller 508 that limit the drive current detected by the current detection means so as not to exceed a predetermined limit current value, and a drive voltage V detected by the voltage detection means. And control means such as a control unit 500 and a comparator 501 that change the limit current value based on the detected value of '.
According to this, as described in the above embodiment, the drive current detected by the current detection means is limited so as not to exceed a predetermined limit current value, thereby preventing damage to the drive source due to overcurrent. Can do. Further, based on the detected value of the driving voltage detected by the voltage detecting means, it can be determined whether or not the voltage drop between the power source and the sheet processing unit has increased and the driving voltage has decreased below a predetermined value. When it is determined that the voltage drop between the power source and the paper processing unit has increased and the drive voltage has fallen below a predetermined value, the limit current value is changed to be larger, and the voltage drop has occurred. However, it is possible to apply a driving voltage of a predetermined magnitude or more to the driving source. Thereby, it is possible to prevent a processing failure in the paper processing unit due to the voltage drop. As described above, according to the present invention, it is possible to prevent a processing failure caused by a voltage drop between the power source and the paper processing unit while preventing damage to the drive source due to overcurrent.
(Aspect B)
In the aspect A, the control unit changes the limit current value based on a comparison result between the detected value of the drive voltage and a threshold value. According to this, as described in the above embodiment, the value of the drive voltage serving as a reference for changing the limit current value can be appropriately changed by a simple process of changing the threshold value.
(Aspect C)
In the aspect B, the control unit changes the limit current value to be larger than a normal value when the detection value of the drive voltage becomes equal to or less than the threshold value, and the detection value of the drive voltage is a predetermined value. When it becomes larger than the threshold value, the limit current value is changed back to the normal value.
According to this, as described in the above embodiment, when the detected value of the drive voltage becomes equal to or less than the threshold value, the voltage drop is changed by changing the limit current value to be larger than the normal value. Even if there is, a driving voltage of a predetermined magnitude or more can be applied to the driving source. Thereby, it is possible to prevent a processing failure in the paper processing unit due to the voltage drop. Further, when the detected value of the drive voltage becomes larger than the predetermined threshold value, the limit current value is changed back to the normal value. Thereby, when the voltage drop is small, it is possible to prevent a wasteful current from flowing to the drive source and suppress wasteful power consumption.
(Aspect D)
In any of the above-described aspects A to C, the control unit is configured to limit the current limit value based on the detected value of the driving voltage only during a paper processing period in which the paper P is processed using the driving force of the driving source. Execute the control to change.
According to this, as described in the above embodiment, a voltage drop occurs in a period such as when the drive source is started, other than the sheet processing period in which the sheet P is processed using the driving force of the drive source. However, control for changing the current limit value is not performed. Therefore, useless power consumption can be further suppressed.
(Aspect E)
In any of the above aspects A to D, a sheet detecting unit such as an entrance sensor 130 that detects the presence or absence of the sheet P, and a sheet number counting unit such as the control unit 500 that counts the number of sheets P detected by the sheet detecting unit. The control means counts the number of sheets P to be processed in batch by the sheet number counting means, and changes the limit current value based on the counting result.
According to this, as described in the above embodiment, it is possible to grasp in advance when the number of sheets P to be collectively processed is large, and it is possible to predict the load of the driving source. Since the limit current value can be changed based on this prediction, it is possible to prevent the occurrence of processing failure even when processing a large number of sheets.
(Aspect F)
In any of the above aspects A to E, the image processing apparatus further includes a communication unit that communicates with a paper supply device such as the image forming apparatus 700 that supplies the paper P to be processed by the paper processing device 100. The limit current value is changed based on at least one of the paper type information, the paper thickness information, and the paper number information of the processing target paper P acquired from the paper supply device.
According to this, as described in the above embodiment, the load of the driving source is predicted by grasping in advance information such as the paper type of the paper P to be processed, the paper thickness, or the number of the paper P. Is possible. Since the limit current value can be changed based on this prediction, it is possible to prevent the occurrence of processing failure even in various paper processes in which at least one of the paper type, paper thickness, and number of sheets is different.
(Aspect G)
In any of the above aspects A to F, the driving source is a driving motor such as a DC motor M1 or M2 that drives a binding processing unit such as the stapler 210 with a bundle of sheets bundled and aligned, or a sheet. It is at least one of drive motors that drive a punching processing unit such as a punch unit 120 that punches a bundle.
According to this, as described in the above embodiment, in the stapling or punching paper processing, it is caused by a voltage drop between the power source and the paper processing unit while preventing damage to the drive source due to overcurrent. Binding failure and punch failure can be prevented.
(Aspect H)
An image forming system including an image forming unit such as an image forming apparatus 700 that forms an image of a sheet, and a sheet processing unit that processes the sheet P on which an image is formed by the image forming unit, wherein the sheet processing unit includes: The sheet processing apparatus 100 according to any one of the above aspects A to G.
According to this, as described in the above embodiment, when the paper P on which the image is formed by the image forming unit is post-processed by the paper processing apparatus 100, while preventing damage to the drive source due to overcurrent, It is possible to prevent a post-processing failure caused by a voltage drop between the power source and a sheet processing unit such as the stapler 210 or the punch unit 120 of the sheet processing apparatus 100.

DESCRIPTION OF SYMBOLS 1 Introduction route 2 Proof conveyance route 3 Conveyance route 111 Paper discharge tray 120 Punch unit (punching processing part)
130 Entrance sensor 210 Stapler (binding processing unit)
300 Folding unit 500 Control unit 501 Comparator 506 Comparator 508 Driver controller 700 Image forming apparatus 100 Paper processing device M1 DC motor on driver side M2 DC motor on clincher side P Paper Pt Paper bundle S Staple needle V Drive voltage before voltage drop (Supply voltage)
Drive voltage after voltage drop

JP 2007-22752 A

Claims (8)

A paper processing apparatus comprising: a driving source; and a paper processing unit that processes paper using the driving force of the driving source,
Current detection means for detecting a drive current flowing through the drive source;
Voltage detection means for detecting a drive voltage applied to the drive source;
Current limiting means for limiting the drive current detected by the current detection means so as not to exceed a predetermined limit current value;
Control means for changing the limit current value based on the detected value of the drive voltage detected by the voltage detection means;
A sheet processing apparatus further comprising: The sheet processing apparatus according to claim 1, wherein
The sheet processing apparatus, wherein the control unit changes the limit current value based on a comparison result between the detected value of the drive voltage and a threshold value. The sheet processing apparatus according to claim 2.
The control unit changes the limit current value to be larger than a normal value when the detection value of the drive voltage becomes equal to or less than the threshold value, and the detection value of the drive voltage is larger than the predetermined threshold value. When it becomes, the sheet processing apparatus changes the limit current value to return to the normal value. In the paper processing apparatus according to any one of claims 1 to 3,
The control means executes control to change the limit current value based on a detection value of the drive voltage only during a paper processing period in which the paper is processed using the driving force of the driving source. Paper processing device. In the paper processing apparatus according to any one of claims 1 to 4,
Paper detection means for detecting the presence or absence of the paper;
Counting means for counting the number of sheets detected by the paper detection means,
The sheet processing apparatus, wherein the control unit counts the number of sheets to be processed at once by the sheet number counting unit and changes the limit current value based on the counting result. In the paper processing apparatus in any one of Claims 1 thru | or 5,
A communication unit that communicates with a paper supply device that supplies paper to be processed by the paper processing device;
The control means changes the limit current value based on at least one of paper type information, paper thickness information, and number information of the paper to be processed, acquired from the paper supply device via the communication means. A paper processing apparatus. The sheet processing apparatus according to any one of claims 1 to 6,
The drive source is at least one of a drive motor that drives a binding processing unit that binds and aligns a plurality of paper bundles, or a drive motor that drives a punching processing unit that punches the paper bundle. Paper processing device. An image forming system comprising: an image forming unit that forms an image of a sheet; and a sheet processing unit that processes a sheet on which an image is formed by the image forming unit.
The image forming system according to claim 1, wherein the sheet processing unit is the sheet processing apparatus according to claim 1.

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