JP2023079392A - Post-processor - Google Patents

Abstract

To provide a post-processor capable of appropriately determining the timing of cleaning of a push-in member.SOLUTION: A post-processor 10, for post-processing a sheet, comprises an alignment tray 20 that receives a sheet therein, a push-in member 22 that receives power and pushes the sheet into the alignment tray 20, and a control unit 100 that determines a necessity/unnecessity to clean the push-in member 22 based on an electric current value required to drive the push-in member 22.SELECTED DRAWING: Figure 1

Description

The present disclosure relates to post-processing devices.

2. Description of the Related Art In copiers and multifunction machines, post-processing devices are known that perform post-processing such as stapling, punching, and folding on sheets discharged from an image forming unit. In the post-processing device, sheets on which images have been formed are accommodated one by one in a tray, and post-processing is performed in a state in which a predetermined number of sheets are aligned on the tray. Specifically, each sheet is conveyed by a pushing member arranged above the tray so as to come into contact with a stopper provided at one end of the tray, and aligned on the tray.

Foreign matter such as toner, oil, and paper dust may adhere to the pushing member. If foreign matter adheres to the pushing member, the sheet conveying force is reduced, resulting in misalignment. Therefore, Japanese Patent Application Laid-Open No. 2009-40537 proposes counting the cumulative number of printed sheets and cleaning the pressing member when the cumulative number of printed sheets reaches a predetermined value.

JP 2009-40537 A

The tendency of foreign matter to adhere to the pushing member may vary depending on the type of sheet (paper type), the type of image (characters, photographs, etc.), the conditions of image formation (single-sided, double-sided), and the like. Therefore, the timing at which cleaning of the pushing member is required also changes according to the type of sheet, the type of image, and the conditions of image formation. Patent document 1 does not consider this point. Therefore, the timing for cleaning the pushing member cannot be determined appropriately.

SUMMARY OF THE INVENTION The present disclosure has been made to solve the problems described above, and an object thereof is to provide a post-processing device capable of appropriately determining the cleaning timing of the pushing member.

According to one aspect, a post-processing device that performs post-processing on sheets includes a tray in which the sheets are stored, a pushing member that receives power and pushes the sheets into the tray, and a current value required to drive the pushing member. and a control unit that determines whether or not cleaning of the pushing member is necessary.

Preferably, the control unit determines whether or not cleaning is necessary according to the amount of change from the reference value of the target parameter value, which is one of the current value and the converted value obtained by converting the current value.

Preferably, the control unit satisfies the first condition that the difference between the reference value and the target parameter value exceeds the first threshold, or the second condition that the ratio of the target parameter value to the reference value is less than the second threshold. Determine if cleaning is required.

Preferably, the tray includes stoppers for aligning the stored sheets. The pushing member includes a rotating member that contacts the sheet and moves the sheet toward the stopper, and a driving portion that receives electric power and rotates the rotating member. The current value is a measurement of the current supplied to the drive.

Preferably, the rotating member comprises a paddle or belt.
Preferably, the tray includes stoppers for aligning the stored sheets. The pushing member includes a rotating member that contacts the sheet and moves the sheet toward the stopper, and a driving portion that receives electric power and rotates the rotating member. The conversion value is a torque value for rotating the rotating member.

Preferably, the control unit disables the process of determining whether or not cleaning is necessary when the number of sheets accommodated in the tray exceeds the reference number of sheets.

Preferably, the post-processing device further includes a reception section that receives selection between the first mode and the second mode. The tray accommodates a plurality of sheets on which images are formed by executing a print job. In response to the acceptance of selection of the first mode by the acceptance unit, the control unit determines whether or not cleaning is necessary for each print job, using current values measured when pushing in each of the plurality of sheets. . In response to the selection of the second mode being accepted by the accepting unit, the control unit uses only the current value measured when pushing the first sheet out of the plurality of sheets for each print job, Determine whether cleaning is necessary.

Preferably, the control unit corrects the target parameter value by a correction amount associated with deformation of the pushing member when the number of sheets accommodated in the tray exceeds the reference number.

Preferably, the control unit determines the correction amount according to at least one of the type of sheet, the type of image printed on the sheet, and the image forming conditions.

Preferably, the control unit determines the reference number of sheets according to at least one of the type of sheet, the type of image printed on the sheet, and the image forming conditions.

Preferably, the image forming conditions indicate either single-sided printing or double-sided printing.
Preferably, the control unit calculates the time during which the pushing member is in contact with the sheet based on the change in the current value, and increases the correction amount as the time increases.

Preferably, the control unit outputs a notification prompting replacement or cleaning of the pushing member in response to determining that cleaning is necessary.

Preferably, the driving section increases the rotation speed of the rotating member in response to the determination by the control section that cleaning is required.

According to the present disclosure, it is possible to appropriately determine the cleaning timing of the pushing member.

1 shows the appearance of a multi-function peripheral equipped with a post-processing device according to Embodiment 1. FIG. It is a figure which shows a pushing member and its peripheral structure. 3 is a diagram showing a functional configuration of a control unit according to Embodiment 1; FIG. It is a figure which shows an example of the measurement result of the current value by a current measurement part. FIG. 10 is a diagram showing changes in the current value when the paddle is in contact with the paper and the amount of foreign matter adhering to the pushing member with respect to the cumulative number of sheets after installing a new pushing member; 5 is a flow chart showing the flow of processing by a control unit according to Embodiment 1; FIG. 10 is a diagram showing an example of a screen for selecting either the first mode or the second mode; FIG. FIG. 10 is a diagram showing the state of the pushing member when the number of sheets on the alignment tray is large; FIG. 13 is a diagram showing a functional configuration of a control unit according to Embodiment 3; 10 is a flow chart showing the flow of processing by a control unit according to Embodiment 3; FIG. 13 is a diagram showing a functional configuration of a control unit according to Embodiment 4; It is a figure explaining the 1st calculation method of a correction amount. FIG. 13 is a flow chart showing the flow of processing of the control unit according to Embodiment 4 when the first calculation method is applied; FIG. FIG. 11 shows a first table used to determine the variable c; FIG. 11 shows a second table used to determine the variable c; FIG. 14 is a flow chart showing the flow of processing of the control unit according to Embodiment 4 when a second calculation method is applied; FIG. FIG. 12 is a diagram showing the operation of a pushing member provided in the post-processing device according to Embodiment 5;

A post-processing device according to an embodiment according to the present disclosure will be described below with reference to the drawings. In the following description, the same parts and components are given the same reference numerals. Their names and functions are also the same. Therefore, detailed description of these will not be repeated. Note that the embodiments and modifications described below may be selectively combined as appropriate.

[Embodiment 1]
<Overall composition>
FIG. 1 shows the appearance of a multi-function machine equipped with a post-processing device according to the first embodiment. As shown in FIG. 1, the multifunction device 1 includes a scanner 2, a printer section 3, a post-processing device 10, and an operation panel 40. As shown in FIG. The printer section 3 includes an image forming unit 5 , a paper feed unit 6 , a fixing unit 8 and a pair of discharge rollers 9 . Further, the printer section 3 includes a body control section 150 that controls the operation of the printer section 3 . The operation panel 40 accepts user's operations.

The body control unit 150 controls each component of the printer unit 3 according to the print job accepted by the operation panel 40 . The print job specifies image data, image forming conditions, paper type, number of copies, post-processing conditions, and the like. Main body control unit 150 includes, for example, a CPU (Central Processing Unit), a ROM (Read Only Memory), a RAM (Random Access Memory), and a non-volatile memory. The CPU develops a program stored in the nonvolatile memory on the RAM and executes it, thereby controlling the operation of the printer section 3 and outputting an operation instruction to the post-processing device 10 . Furthermore, the body control unit 150 may include a dedicated hardware circuit.

The paper feed unit 6 accommodates sheets (hereinafter referred to as "paper"). The paper feed unit 6 supplies paper to the transport path 7 one by one. The paper supplied from the paper feed unit 6 passes through the image forming unit 5 and the fixing unit 8 and is discharged to the post-processing device 10 by the discharge roller pair 9 .

The image forming unit 5 forms a toner image on paper according to a print job by a well-known electrophotographic method. For example, the image forming unit 5 forms on paper a toner image corresponding to an original image optically read by the scanner 2 or image data transferred from a computer (not shown). A fixing unit 8 fixes the toner image to the paper.

The post-processing device 10 can perform various post-processing such as stapling, punching, and paper folding. Here, the stapling device will be described. The post-processing device 10 includes a receiving roller pair 11, conveying roller pairs 12 to 14, a guide plate 15, an electric stapler 16, an alignment tray 20, a pushing member 22, a discharge tray 30, and a controller 100.

The paper discharged from the discharge roller pair 9 is introduced into the post-processing device 10 from the receiving roller pair 11 . In post-processing device 10 , paper is transported in the direction of arrow A by transport roller pairs 12 and 13 , fed one by one onto alignment tray 20 from transport roller pair 14 , and aligned by pushing member 22 . As a result, a predetermined number of sheets are stacked on the alignment tray 20 in an aligned state.

The electric stapler 16, which operates as a post-processing section, staples the ends of a predetermined number of sheet bundles.

Discharge rollers 31 a and 31 b discharge the stapled bundle of sheets from alignment tray 20 onto discharge tray 30 . Normally, the discharge roller 31b is arranged apart from the discharge roller 31a, fixes the paper bundle by pressing against the discharge roller 31a through the paper bundle, and discharges the paper bundle onto the discharge tray 30 by rotating. .

The control unit 100 controls operations of the post-processing device 10 . The control unit 100 includes, for example, a CPU, a ROM, a RAM, and a nonvolatile memory. The CPU controls the operation of the post-processing device 10 by developing the program stored in the non-volatile memory on the RAM and executing the program. Furthermore, the control unit 100 may have a dedicated hardware circuit.

<Paper Alignment Method>
A method of aligning sheets in the alignment tray 20 will be described with reference to FIG. FIG. 2 is a diagram showing a pushing member and its peripheral configuration.

As shown in FIG. 2, the alignment tray 20 is installed with an inclination so as to stand up in the storage direction indicated by the arrow B. As shown in FIG. The alignment tray 20 includes a reference stopper 21 for aligning the accommodated sheets P at the lower end, that is, the end in the direction opposite to the arrow B (hereinafter referred to as alignment direction B').

The pushing member 22 receives power and pushes the paper P into the alignment tray 20 . The pushing member 22 is installed above the alignment tray 20 . The pushing member 22 includes a rotating member 26 and a driving portion 25 . The rotating member 26 has a support shaft 23 and one or more paddles 24 (two paddles 24 in the example shown in FIG. 2) attached to the support shaft 23 . A rotating member 26 having two paddles 24 will be described below. However, the rotating member 26 may have only one paddle 24 or may have three or more paddles 24 .

The support shaft 23 is parallel to the upper surface of the alignment tray 20 and perpendicular to the alignment direction B'. The drive unit 25 is, for example, a motor, and rotates the support shaft 23 . It should be noted that the drive unit 25 may be configured by a drive transmission mechanism such as a clutch or a solenoid instead of the motor. The drive unit 25 rotates the support shaft 23 so that the movement direction of the point closest to the upper surface of the alignment tray 20 on the peripheral surface of the support shaft 23 coincides with the alignment direction B'.

The two paddles 24 are attached at a predetermined interval in the circumferential direction of the support shaft 23 . Each paddle 24 contacts the uppermost sheet P on the alignment tray 20 as the support shaft 23 rotates. At this time, a frictional force is generated between the paddle 24 and the paper P. The paddle 24 uses the frictional force to push the paper P in the alignment direction B'. That is, when the paper P is fed one by one onto the alignment tray 20 from the transport roller pair 14, the two paddles 24 come into contact with the paper P in turn and apply force to the paper P in the alignment direction B'. As a result, the paper P is moved and aligned until the leading edge in the alignment direction B' comes into contact with the reference stopper 21 .

Further, a pair of alignment plates (not shown) may be installed on the alignment tray 20 for aligning the sheets P in the width direction. Each time a sheet of paper P is accommodated on the alignment tray 20, the aligning plate moves in a direction perpendicular to the accommodating direction B to a position corresponding to the width size of the sheet of paper P, and moves the sheet of paper P in the width direction. be consistent.

In this way, the sheets stored on alignment tray 20 are aligned before they are stapled. Thereafter, the electric stapler 16 staples the aligned sheets.

<Functional configuration of control unit>
The control unit 100 determines whether or not the pushing member 22 needs to be cleaned based on the current value required to drive the pushing member 22 .

3 is a diagram illustrating a functional configuration of a control unit according to Embodiment 1; FIG. As shown in FIG. 3 , control section 100 includes current measurement section 101 , change amount calculation section 102 , determination section 103 , and notification section 104 .

A current measurement unit 101 measures a current value required to drive the pushing member 22 . Specifically, the current measurement unit 101 measures the current value supplied to the drive unit 25 of the pushing member 22 .

FIG. 4 is a diagram showing an example of a current value measurement result by a current measuring unit. As shown in FIG. 4, during periods t ₀ , t ₁ , . This is because the contact of the paddle 24 with the paper P generates a frictional force between the paddle 24 and the paper P, and the electric power required to rotate the rotating member 26 increases.

The current measurement unit 101 compares the measured current value with a threshold value Th0 that is slightly larger than the current value when none of the paddles 24 is in contact with the paper P. It is possible to specify the periods t ₀ , t ₁ , . . . The current measuring unit 101 identifies the current value I _k for each period t _k (k=0, 1, . . . ) during which any paddle 24 is in contact with the paper P.

_The current measurement unit 101 measures the current of each sheet P during periods t _m , . A representative value of _the values I _m , . Current measurement section 101 outputs the calculated representative value to variation calculation section 102 .

A method for calculating the representative current value is not particularly limited. _{For example} , _the current measurement unit 101 measures the average value of the current values I _m , _. Calculate as a value. Alternatively, the current measurement unit 101 may calculate the maximum value of the current values _Im , . . . , Im _+p as the representative current value. Alternatively, the current measuring unit 101 measures (p ₊ 1-2q) current values I _m , . An average value of the current values may be calculated as the representative current value.

The change amount calculation unit 102 shown in FIG. 3 calculates the amount of change from the reference value of the representative current value for each sheet P output from the current measurement unit 101 .

FIG. 5 is a diagram showing changes in the current value when the paddle is in contact with the paper and the amount of foreign matter adhering to the pushing member with respect to the cumulative number of sheets after the installation of the new pushing member. In the graph shown in FIG. 5, the horizontal axis represents the cumulative number of sheets P pushed by the pushing member 22, the left vertical axis represents the representative current value output from the current measuring unit 101, and the right vertical axis represents: 3 represents the amount of foreign matter adhering to the paddle 24 of the pushing member 22. FIG. Foreign matter includes toner, oil, and paper dust. A line 51 indicates changes in the representative current value, and a line 52 indicates the amount of adhered foreign matter.

Toner, paper dust and oil can adhere to the paddle 24 when the paddle 24 and the paper P are in contact. Therefore, as shown in FIG. 5, as the cumulative number of sheets P pushed by the pushing member 22 increases, the amount of foreign matter adhering to the paddle 24 of the pushing member 22 increases.

A torque for rotating the paddle 24 is represented by the following formula (1).
Torque = F x r
=μ×N×r Formula (1)
In equation (1), μ is the coefficient of friction between the paddle 24 and the paper. N is the normal force from the paddle 24 on the paper. r is the distance between the tip of the paddle 24 and the center of the support shaft 23;

When foreign matter adheres to the paper P, the coefficient of friction μ between the paddle 24 and the paper P decreases. Therefore, the torque for rotating the paddle 24 also decreases. The current value supplied to the driving section 25 decreases as the torque decreases. Therefore, as shown in FIG. 5, the representative current value output from the current measurement unit 101 decreases as the cumulative number of sheets increases.

The change amount calculation unit 102 calculates the amount of change of the representative current value from the reference value as a parameter that indirectly represents the amount of foreign matter adhered to the paddle 24 . The change amount calculator 102 uses the representative current value output from the current measuring unit 101 as a reference value when no foreign matter adheres to the paddle 24 or when the amount of foreign matter adhered to the paddle 24 is small. For example, the change amount calculation unit 102 calculates a value (for example, an average value, a median value, average value excluding outliers, etc.) as the reference value. The change amount calculation unit 102 calculates the difference (reference value−representative current value) between the reference value and the representative current value output from the current measurement unit 101 as the change amount.

The determination unit 103 determines whether or not the pushing member 22 needs to be cleaned based on the amount of change calculated by the amount-of-change calculation unit 102 . Typically, the determination unit 103 determines that cleaning is necessary when the amount of change exceeds a predetermined threshold.

Notification unit 104 outputs a notification according to the determination result of determination unit 103 . Specifically, the notification unit 104 displays, on the operation panel 40 (see FIG. 1), a notification screen that prompts replacement or cleaning of the pushing member 22 when it is determined that cleaning is necessary.

<Processing flow of the control unit>
6 is a flowchart illustrating a flow of processing by a control unit according to Embodiment 1. FIG. First, the controller 100 measures the current value required to drive the pushing member 22 (step S1). For example, the control unit 100 measures the representative current value described above for each sheet P. FIG.

Next, the control unit 100 calculates the amount of change in the current value with respect to the reference value (step S2). For example, the control unit 100 calculates the difference between the reference value and the representative current value (reference value−representative current value) as the amount of change.

Next, the control unit 100 determines whether or not the amount of change exceeds the threshold (step S3). If the amount of change exceeds the threshold (YES in step S3), control unit 100 outputs a notification prompting cleaning (step S4). If the amount of change does not exceed the threshold (NO in step S3) or after step S4, the control unit 100 terminates the process.

As described above, the post-processing device 10 according to the first embodiment performs post-processing on the paper P. FIG. The post-processing device 10 includes an aligning tray 20 that accommodates the paper P, a pushing member 22 that receives power and pushes the paper P into the aligning tray, and a current value required to drive the pushing member 22. and a control unit 100 that determines whether or not cleaning is necessary.

As shown in FIG. 5, the current value required to drive the pushing member 22 correlates with the amount of adhered foreign matter. Therefore, the controller 100 can accurately determine whether or not the pushing member 22 needs to be cleaned by using the current value required to drive the pushing member 22 . As a result, the post-processing device 10 can appropriately determine the cleaning timing of the pushing member 22 .

The control unit 100 determines whether or not cleaning is necessary according to the amount of change from the reference value of the current value (specifically, the representative current value described above). When no foreign matter adheres to the pushing member 22, or when the amount of foreign matter adhered to the pushing member 22 is small, the representative current value output from the current measuring unit 101 depends on the individual difference of the pushing member 22. can fluctuate. By using the amount of change described above, the influence of individual differences in the pushing member 22 is eliminated. Therefore, regardless of the individual difference of the pushing member 22, whether or not the pushing member 22 needs to be cleaned can be determined with high accuracy.

Specifically, control unit 100 determines that cleaning is necessary when the condition that the difference between the reference value and the representative current value exceeds the threshold is satisfied. Accordingly, the control unit 100 can determine whether or not cleaning is necessary through relatively simple arithmetic processing.

The aligning tray 20 includes a reference stopper 21 for aligning the accommodated sheets P. As shown in FIG. The pushing member 22 includes a rotating member 26 that comes into contact with the paper P and moves the paper P toward the reference stopper 21 , and a drive unit 25 that receives electric power and rotates the rotating member 26 . The above current value is a measured value of the current supplied to the driving section 25 . The current value supplied to the drive unit 25 correlates with the torque for rotating the rotating member 26 when the rotating member 26 and the paper P are in contact with each other. The torque depends on the amount of foreign matter adhered to the rotating member 26 . Therefore, the amount of foreign matter adhered to the pressing member 22 can be indirectly estimated from the current value supplied to the drive unit 25 . As a result, it is possible to accurately determine whether or not the pushing member 22 needs to be cleaned.

When the control unit 100 determines that cleaning is necessary, the control unit 100 outputs a notification prompting replacement or cleaning of the pushing member 22 . Accordingly, the user can replace or clean the pushing member 22 at an appropriate timing by confirming the notification.

[Embodiment 2]
Compared with the post-processing device 10 according to the first embodiment, the post-processing device according to the second embodiment selects either the first mode or the second mode as the mode for determining whether or not cleaning is necessary. They are different in that respect. The first mode is a mode in which the need for cleaning is determined each time each of a plurality of sheets of paper P on which images have been formed by execution of a print job by the image forming unit 5 is accommodated in the alignment tray 20 . The second mode is a mode in which it is determined whether or not cleaning is necessary only when the first sheet P of the plurality of sheets P on which images have been formed by executing the print job is accommodated in the alignment tray 20 .

It usually takes a long time for the amount of foreign matter to adhere to the pushing member 22 to the extent that the force for conveying the paper P is lowered. Therefore, the load on the control unit 100 is reduced by selecting the second mode.

Control unit 100 according to the second embodiment displays a screen for selecting either the first mode or the second mode on operation panel 40 . The operation panel 40 operates as a reception unit that receives selection between the first mode and the second mode.

FIG. 7 is a diagram showing an example of a screen for selecting either the first mode or the second mode. A screen 200 shown in FIG. 7 is displayed on the operation panel 40 and includes radio buttons 201 and 202 . The user presses radio button 201 to select the first mode, and presses radio button 202 to select the second mode.

In response to the operation panel 40 accepting the selection of the first mode, the control unit 100 measures for each print job when each of the plurality of sheets P on which images are formed by executing the print job is pushed. The necessity of cleaning is determined using the measured current value. That is, the current measurement unit 101 of the control unit 100 outputs the representative current value measured for each sheet P. FIG. The determining unit 103 compares the amount of change in the representative current value with respect to the reference value and the threshold for each sheet P, and determines whether or not cleaning is necessary based on the comparison result.

In response to the operation panel 40 accepting the selection of the second mode, the control unit 100 selects the first sheet of the plurality of sheets P on which an image is formed by executing the print job for each print job. Only the measured current value measured when pushing P is used to determine whether cleaning is necessary. That is, the current measuring section 101 of the control section 100 outputs the representative current value only for the first sheet of paper P. FIG. The determining unit 103 compares the amount of change in the representative current value with respect to the reference value and the threshold for the first sheet of paper P, and determines whether or not cleaning is necessary based on the comparison result.

[Embodiment 3]
FIG. 8 is a diagram showing the state of the pushing member when the number of sheets on the alignment tray is large. As shown in FIG. 8, when the number of sheets P on the alignment tray 20 is large, the amount of deformation of the paddle 24 of the pushing member 22 increases, and the contact area between the paddle 24 and the sheets P increases. As a result, the torque for rotating the rotating member 26 increases, and the current supplied to the driving section 25 also increases. Due to the increase in the current value due to the deformation of the paddle 24, there is a possibility that it may not be possible to accurately determine whether the pushing member 22 needs to be cleaned.

Therefore, the post-processing apparatus according to the third embodiment omits the determination of whether or not cleaning of the pressing member 22 is necessary when the number of sheets P on the alignment tray 20 exceeds the reference number R of sheets. The reference number of sheets R is determined by increasing the current value supplied to the drive unit 25 as the paddle 24 deforms when plain paper (grammage 60 to 90 g/m ² ) on which character images are printed is accommodated in the alignment tray 20 . indicates the number of sheets to start. The reference number R is determined in advance by experiments or the like.

9 is a diagram illustrating a functional configuration of a control unit according to Embodiment 3; FIG. The post-processing apparatus according to the third embodiment differs from the post-processing apparatus 10 according to the first embodiment in that the control section 100A shown in FIG. 9 is provided instead of the control section 100. FIG.

The control unit 100A is different from the control unit 100 according to the first embodiment in that the control unit 100A includes an accommodated sheet number management unit 105 .

The accommodated sheet number management unit 105 manages the number of sheets P accommodated in the alignment tray 20 (hereinafter referred to as "accommodated sheet number"). The stored sheet number management unit 105 has a counter, and increments the value of the counter by one each time the sheet P is discharged from the discharge roller pair 9 . The stored sheet number management unit 105 resets the value of the counter to 0 when the post-processed sheet bundle is discharged to the discharge tray 30 by the discharge rollers 31a and 31b. Accordingly, the value of the counter held by the accommodated sheet number management unit 105 represents the accommodated sheet number.

When the value of the counter (that is, the number of sheets stored) exceeds the reference number R, the stored sheet number management unit 105 disables the process of determining whether or not cleaning is necessary. That is, the accommodated sheet number management unit 105 disables the operations of the change amount calculation unit 102 and the determination unit 103 . As a result, when the number of stored sheets exceeds the reference number R, the determination of whether or not cleaning of the pushing member 22 is necessary is omitted.

FIG. 10 is a flowchart illustrating the flow of processing by a control unit according to Embodiment 3; The flowchart shown in FIG. 10 differs from the flowchart shown in FIG. 6 in that step S11 is included after step S1.

In step S11, the control unit 100A determines whether or not the accommodated number of sheets exceeds the reference number R of sheets. If the number of stored sheets exceeds the reference number R (YES in step S11), the control section 100A terminates the process. If the number of stored sheets does not exceed the reference number R (YES in step S11), the control section 100A advances the process to step S2.

According to the third embodiment, it is possible to prevent the necessity of cleaning the pushing member 22 from being accurately determined due to an increase in the current value due to the deformation of the paddle 24 .

[Embodiment 4]
The post-processing apparatus according to the fourth embodiment corrects the current value by the correction amount associated with the deformation of the rotating member 26 when the number of sheets P on the alignment tray 20 exceeds the reference number R. As a result, the post-processing device can accurately determine whether or not cleaning of the pressing member 22 is necessary using the current value from which the influence of the deformation of the rotating member 26 has been removed.

11 is a diagram illustrating a functional configuration of a control unit according to Embodiment 4; FIG. The post-processing apparatus according to the fourth embodiment differs from the post-processing apparatus according to the third embodiment in that it includes a control section 100B shown in FIG. 11 instead of the control section 100A.

Control unit 100B differs from control unit 100A according to the third embodiment in that correction unit 106 is provided. As in the third embodiment, the accommodated sheet number management unit 105 according to the fourth embodiment manages the number of sheets P accommodated in the alignment tray 20 (the number of accommodated sheets). However, the accommodated number management unit 105 according to the fourth embodiment disables the operations of the change amount calculation unit 102 and the determination unit 103 when the counter value (that is, the accommodated number) exceeds the reference number R. Instead, it outputs a correction instruction to the correction unit 106 .

Upon receiving a correction instruction from the accommodation number management unit 105 , the correction unit 106 corrects the current value output from the current measurement unit 101 by the correction amount associated with the deformation of the rotating member 26 . A method of calculating the correction amount will be described below.

(First Method of Calculating Correction Amount)
FIG. 12 is a diagram for explaining the first calculation method of the correction amount. FIG. 12 shows changes in the current value when the number of paddles accommodated is increased in a state in which no foreign matter adheres to the paddle 24 or a small amount of foreign matter adheres. FIG. 12 shows the contact times T_1, T_u, and T_v between the paddle 24 and the paper and the time supplied to the drive unit 25 when the number of sheets contained is 1, u (u>1), and v (v>u). Current values I_1, I_u, and I_v are shown, respectively.

As shown in FIG. 12, the contact time between the paddle 24 and the paper P increases as the number of stored sheets increases. This is because the paddle 24 is deformed (see FIG. 8). Further, as the paddle 24 deforms, the frictional force between the paddle 24 and the paper P increases, and the current value supplied to the driving section 25 increases. Therefore, as the number of stored sheets increases, the current value supplied to the drive unit 25 increases. The correction unit 106 calculates a correction amount in order to eliminate such influence of the accommodated number of sheets.

The correction unit 106 calculates the difference between the contact time T_1 and the current value I_1 when the number of stored sheets is 1 and the contact time T_k and the current value I_k when the number of stored sheets is k (k is an integer equal to or greater than 1). Information indicating the correlation between ΔT_k and ΔI_k is stored in advance. The information is created in advance by experiments or the like. That is, the information is generated based on (ΔT_1, ΔI_1), (ΔT_2, ΔI_2), . The information may represent a function or may represent a table, for example.

As described in the first embodiment, the current measurement unit 101 identifies periods t ₀ , t ₁ , . . . during which any of the paddles 24 is in contact with the paper. The correction unit 106 calculates the average time of the specified periods t _k , t _k+1 , . . . (hereinafter referred to as “average contact time T”) for each sheet. The correction unit 106 calculates the difference ΔT (=TT_1) between the average contact time T and the contact time T_1 when the number of contained sheets is one. The correction unit 106 uses the correlation information to calculate a difference ΔI corresponding to the calculated difference ΔT as a correction amount associated with deformation of the paddle 24 .

Correction unit 106 calculates a correction amount for each sheet P, and corrects the representative current value by subtracting the correction amount from the representative current value output from current measurement unit 101 .

FIG. 13 is a flowchart showing the flow of processing by the control unit according to Embodiment 4 when the first calculation method is applied. The flowchart shown in FIG. 13 differs from the flowchart shown in FIG. 10 in that steps S21 and S22 are included.

If the number of stored sheets does not exceed the reference number R (YES in step S11), the control section 100B advances the process to step S21. In step S21, the control unit 100B calculates the difference ΔT (=TT_1) between the average contact time T between the paddle 24 and the paper P and the contact time T_1 when the number of sheets contained is one. Then, the control unit 100B uses the correlation information to calculate the difference ΔI corresponding to the calculated difference ΔT as the correction amount associated with the deformation of the paddle 24 .

Next, the control unit 100B corrects the representative current value by subtracting the correction amount from the representative current value output from the current measuring unit 101 (step S22). After step S22, the control unit 100B shifts the process to step S2.

(Second calculation method of correction amount)
A second calculation method is a method of calculating the correction amount according to the type of paper P (paper type), the type of image printed on the paper P (photograph, character), and the image forming conditions.

As shown in FIG. 11, control unit 100B receives paper type information indicating paper type and printing conditions (image type and forming conditions) from main body control unit 150 (see FIG. 1) of printer unit 3. receive information. The image forming condition indicates either double-sided printing or single-sided printing.

The correction unit 106 calculates the correction amount according to the following formula (2).
Correction amount = a x (N _COUNT - c) Equation (2)
In Equation (2), a is a predetermined constant. N _COUNT is the number of sheets P accommodated in the alignment tray 20 (the number of accommodated sheets), and is the counter value of the accommodated sheet number management unit 105 . c is a variable determined according to the type of paper P (paper type), the type of image printed on the paper P (photograph, character), and the image forming conditions.

FIG. 14 is a diagram showing a first table used for determining variable c. Correction unit 106 stores in advance a first table shown in FIG. As shown in FIG. 14, the first table associates whether or not the paper type is considered, the paper type, and the increase/decrease amount from the reference number R of sheets.

FIG. 15 shows a second table used to determine the variable c. Correction unit 106 stores in advance a first table shown in FIG. As shown in FIG. 15, the second table associates whether or not the printing conditions are taken into consideration, the printing conditions, and the amount of increase or decrease from the reference number R of sheets.

The operation panel 40 accepts from the user whether or not the paper type and printing conditions are considered. For example, the operation panel 40 accepts whether or not the paper type and printing conditions are considered when initializing the MFP 1 . Correction unit 106 stores information indicating the content accepted by operation panel 40 .

If the paper type is not taken into consideration, the correction unit 106 reads the increase/decrease amount corresponding to "no consideration of paper type" from the first table shown in FIG. When considering the paper type, the correction unit 106 reads the increase/decrease amount corresponding to the paper type from the first table shown in FIG.

If the printing conditions are not taken into consideration, the correction unit 106 reads the increase/decrease amount corresponding to "no consideration of printing conditions" from the second table shown in FIG. When considering the printing conditions, the correction unit 106 reads the increase/decrease amount corresponding to the printing conditions from the second table shown in FIG.

The correcting unit 106 sets the value obtained by adding the sum of the reading increase/decrease amounts to the reference number R as a variable c. The correction unit 106 calculates the correction amount by substituting the variable c and the current accommodated sheet number N _COUNT into the above equation (2).

As shown in FIGS. 14 and 15, "0" is set as the increase/decrease amount when the paper type and printing conditions are not considered. Therefore, the correction unit 106 determines the reference number of sheets R as the value of the variable c when the paper type and printing conditions are not considered.

FIG. 16 is a flowchart showing the flow of processing by the control unit according to Embodiment 4 when the second calculation method is applied. The flowchart shown in FIG. 16 differs from the flowchart shown in FIG. 13 in that steps S31 to S34 are included instead of step S21.

If the number of stored sheets does not exceed the reference number R (YES in step S11), the control section 100B advances the process to step S31. In step S31, control unit 100B determines whether or not to consider the paper type and printing conditions. Control unit 100B may determine whether or not to consider the paper type and printing conditions based on the information indicating the content received by operation panel 40 .

If neither the paper type nor the printing conditions are considered (NO in step S31), the control section 100B determines the reference number R as the value of the variable c (step S32).

If at least one of the paper type and printing conditions is also considered (YES in step S31), control unit 100B uses the first table shown in FIG. 14 and the second table shown in FIG. 15 to determine the value of variable c. (Step S33).

After steps S32 and S33, the control unit 100B calculates the correction amount by substituting the value of the variable c and the current accommodated sheet number N _COUNT into the above equation (2) (step S34). After that, the control unit 100B shifts the process to step S22.

(Third calculation method of correction amount)
The third calculation method differs from the second calculation method in that the following formula (3) is used instead of formula (2).
Correction amount = a x (N _COUNT - c) x b Expression (3)
b is a coefficient determined according to the shape and material of the pushing member 22 .

When the pushing member 22 is attached to the post-processing device 10 , the value of the coefficient b corresponding to the shape and material of the pushing member 22 is set in the correction unit 106 . For example, the value of the coefficient b is selected from "0.99", "1", and "1.01" according to the shape and material of the pushing member 22. FIG.

(Fourth calculation method of correction amount)
The fourth calculation method differs from the third calculation method in that the following formula (4) is used instead of formula (3).
Correction amount=a×(N _COUNT −c)×b×d Equation (4)
d is a coefficient determined according to the cumulative number of sheets pushed by the pushing member 22 (hereinafter referred to as "accumulated number of processed sheets"). Note that the coefficient b may be fixed at "1", or may be set to a value according to the shape and material of the pushing member 22 according to the third calculation method.

Depending on the shape and material of the pushing member 22, the deformed state may be maintained after long-term use. Maintaining the deformed state may reduce the normal force between the paddle 24 and the paper. Therefore, an upper limit value of the cumulative number of sheets that can be used, which is determined in consideration of the durability of the pushing member 22, is preset in the correction unit 106. FIG. The correction unit 106 determines the coefficient d according to the ratio of the current cumulative processed number of sheets to the upper limit. For example, the correction unit 106 sets the value of the coefficient d to "1.01" when the ratio is 50% or less, and sets the value of the coefficient d to "1" when the ratio is 51% to 80%. and determine the value of the coefficient d to be "0.99" when the percentage is 81% or more.

[Embodiment 5]
17A and 17B are diagrams showing the operation of the pushing member provided in the post-processing apparatus according to Embodiment 5. FIG. The post-processing apparatus according to the fifth embodiment differs from the post-processing apparatuses according to the first to fourth embodiments in that it includes a pressing member 22A shown in FIG.

As shown in FIG. 17, the pushing member 22A includes a driving portion 25A and a rotating member 26A. The rotating member 26A includes a fixed roller 121, a movable roller 122, a connecting rod 123, and a belt 124.

The shaft of the fixed roller 121 is installed at a fixed position. The axis of the movable roller 122 is rotatable around the axis of the fixed roller 121 . The connecting rod 123 rotatably supports the shaft of the fixed roller 121 and the shaft of the movable roller 122 so as to keep the distance between the shaft of the fixed roller 121 and the shaft of the movable roller 122 constant. Therefore, the movable roller 122 moves in an arc around the fixed roller 121 . Belt 124 is suspended between fixed roller 121 and movable roller 122 .

Drive unit 25A rotates fixed roller 121 . 25 A of drive parts are motors, for example. The drive unit 25A may be configured by a drive transmission mechanism such as a clutch or a solenoid instead of the motor. The rotation of the fixed roller 121 by the drive unit 25A causes the belt 124 to rotate in the direction of the arrow D. As shown in FIG.

When no paper is accommodated in the alignment tray 20, the movable roller 122 is locked at the retracted position by a lock mechanism (not shown) (see the upper part of FIG. 17). When the sheet P is accommodated in the alignment tray 20 , the lock by the locking mechanism is released, and the movable roller 122 is lowered by its own weight and comes into contact with the sheet on the alignment tray 20 . As a result, the rotation of the belt 124 pushes the paper P toward the reference stopper 21 and aligns it.

As shown in the middle and lower stages of FIG. 17, the height of movable roller 122 varies according to the number of sheets P on alignment tray 20 . Therefore, the contact area and normal force between the belt 124 and the paper P are substantially constant regardless of the number of papers on the alignment tray 20 .

[Modification]
In Embodiments 1 to 5 above, the post-processing device is provided with control units 100, 100A, and 100B. However, the controllers 100 , 100</b>A, and 100</b>B may be integrated with the body controller 150 of the printer section 3 . In this case, the multifunction machine 1 includes an alignment tray 20 that accommodates sheets, pushing members 22 and 22A that receive power and push the sheets P into the alignment tray 20, and a current value required to drive the pushing members 22 and 22A. Therefore, it is regarded as a post-processing device including control units 100, 100A, and 100B for determining whether or not cleaning of the pushing members 22 and 22A is necessary.

In the first to fifth embodiments described above, change amount calculation section 102 calculates the difference (reference value−representative current value) between the reference value and the representative current value output from current measurement section 101 as the amount of change. bottom. However, the change amount calculator 102 may calculate the ratio of the representative current value to the reference value (representative current value/reference value) as the change amount. In this case, the determination unit 103 may determine that cleaning is necessary when the condition that the ratio (representative current value/reference value) is less than a predetermined threshold is satisfied.

As described above, the value of current supplied to drive unit 25 correlates with the value of torque for rotating rotating member 26 . Therefore, the change amount calculation unit 102 may convert the representative current value output from the current measurement unit 101 into a torque value for rotating the rotating member 26 . Then, the change amount calculation unit 102 may calculate the amount of change of the converted value with respect to the reference value. In this case, as a reference value, the torque for rotating the rotating members 26 and 26A when no foreign matter adheres to the rotating members 26 and 26A or when the amount of foreign matter adhering to the rotating members 26 and 26A is small. value is used.

When the determination unit 103 determines that cleaning is necessary, the driving units 25 and 25A may increase the rotation speed of the rotating members 26 and 26A. As a result, even when the frictional force between the rotating members 26 and 26A and the paper is reduced due to foreign substances adhering to the rotating members 26 and 26A, the driving force to move the paper P to the reference stopper 21 is obtained. increases, and misalignment of the paper P is suppressed.

Before step S11 in the flowcharts shown in FIGS. 10, 13 and 16, steps S31 to S33 shown in FIG. , step S11 may be executed. That is, the control unit determines the reference number of sheets according to at least one of the type of paper P, the type of image printed on the paper P, and the image forming conditions. As a result, the reference number of sheets is appropriately changed according to the type of paper P, the type of image printed on the paper P, and the image forming conditions.

It should be considered that the embodiments disclosed this time are illustrative in all respects and not restrictive. The scope of the present invention is indicated by the scope of the claims rather than the above description, and is intended to include all modifications within the scope and meaning equivalent to the scope of the claims.

1 MFP 2 Scanner 3 Printer Section 5 Image Forming Unit 6 Paper Feeding Unit 7 Conveying Path 8 Fixing Unit 9 Discharge Roller Pair 10 Post-Processing Device 11 Receiving Roller Pair 12, 13, 14 Conveyance Roller pair 15 Guide plate 16 Electric stapler 20 Alignment tray 21 Reference stopper 22, 22A Pushing member 23 Spindle 24 Paddle 25, 25A Drive unit 26, 26A Rotating member 30 Ejection tray 31a, 31b discharge roller, 40 operation panel, 100, 100A, 100B control unit, 101 current measurement unit, 102 change amount calculation unit, 103 determination unit, 104 notification unit, 105 accommodation number management unit, 106 correction unit, 121 fixed roller, 122 Movable roller, 123 connecting rod, 124 belt, 150 main control unit, 200 screen, 201, 202 radio button.

Claims (15)

A post-processing device for performing post-processing on a sheet,
a tray in which the sheet is accommodated;
a pushing member that receives power and pushes the sheet into the tray;
and a control unit that determines whether or not cleaning of the pushing member is necessary based on a current value required to drive the pushing member. The control unit determines whether or not the cleaning is necessary according to a change amount from a reference value of a target parameter value, which is one of the current value and a converted value obtained by converting the current value. Item 1. The post-processing device according to item 1. The control unit satisfies a first condition that the difference between the reference value and the target parameter value exceeds a first threshold, or a second condition that the ratio of the target parameter value to the reference value is less than a second threshold. 3. The post-processing device according to claim 2, wherein said post-processing device determines that said cleaning is necessary in response to said cleaning. the tray includes a stopper for aligning the accommodated sheets;
The pushing member is
a rotating member that contacts the sheet and moves the sheet toward the stopper;
a driving unit that receives the electric power and rotates the rotating member;
4. The post-processing device according to claim 1, wherein said current value is a measured value of current supplied to said drive unit. 5. A post-processing device according to claim 4, wherein said rotating member comprises a paddle or a belt. the tray includes a stopper for aligning the accommodated sheets;
The pushing member is
a rotating member that contacts the sheet and moves the sheet toward the stopper;
a driving unit that receives the electric power and rotates the rotating member;
4. The post-processing device according to claim 3, wherein said conversion value is a torque value for rotating said rotating member. The post-processing apparatus according to any one of claims 1 to 6, wherein the control unit disables the process of determining whether or not cleaning is necessary when the number of sheets accommodated in the tray exceeds a reference number of sheets. . further comprising a reception unit that receives selection between the first mode and the second mode,
The tray accommodates a plurality of sheets on which images are formed by execution of a print job,
The control unit
In response to the selection of the first mode being accepted by the accepting unit, the need for cleaning is determined for each print job using the current value measured when each of the plurality of sheets is pushed. death,
using only the current value measured when pushing a first sheet out of the plurality of sheets for each print job in response to the receiving unit receiving the selection of the second mode, The post-processing device according to any one of claims 1 to 6, which determines whether or not said cleaning is necessary. 4. The post-processing apparatus according to claim 2, wherein said control unit corrects said target parameter value by a correction amount associated with deformation of said pushing member when the number of sheets accommodated in said tray exceeds a reference number of sheets. 10. The post-processing apparatus according to claim 9, wherein said control unit determines said correction amount according to at least one of a type of said sheet, a type of image printed on said sheet, and a formation condition of said image. 10. The post-processing apparatus according to claim 7, wherein said control unit determines said reference number of sheets according to at least one of a type of said sheet, a type of image printed on said sheet, and a forming condition of said image. . 12. The post-processing device according to claim 10, wherein said image forming condition indicates either single-sided printing or double-sided printing. The control unit
calculating the time during which the pushing member is in contact with the sheet based on the change in the current value;
10. The post-processing device according to claim 9, wherein the longer the time, the larger the correction amount. The post-processing device according to any one of claims 1 to 13, wherein the control unit outputs a notification prompting replacement or cleaning of the pushing member in response to determining that the cleaning is necessary. The post-processing device according to any one of claims 4 to 6, wherein the driving section increases the rotation speed of the rotating member in response to the control section determining that the cleaning is necessary.

Images