Aftertreatment Device

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

[Technical Field]

[0001] The present disclosure relates to an aftertreatment device. [Background technology]

[0002] In copiers and multifunction peripherals, 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 with images formed thereon are stored one by one in a tray, and post-processing is performed with a predetermined number of sheets aligned on the tray. Specifically, a pushing member disposed above the tray transports each sheet so that it contacts a stopper provided at one end of the tray, and the sheets are aligned on the tray.

[0003] Foreign matter such as toner, oil, and paper dust can adhere to the pushing member. When foreign matter adheres to the pushing member, the sheet conveying force decreases, leading to misalignment. For this reason, Japanese Patent Application Laid-Open No. 2009-40537 proposes counting the cumulative number of printed sheets and cleaning the pushing member when the cumulative number of printed sheets reaches a predetermined value. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2009-40537 Summary of the Invention [Problem to be solved by the invention]

[0005] The tendency for foreign matter to adhere to the pressing member can vary depending on the type of sheet (paper type), the type of image (text, photo, etc.), the conditions for image formation (single-sided, double-sided), etc. Therefore, the timing when cleaning of the pressing member is necessary also varies depending on the type of sheet, the type of image, and the conditions for image formation. Patent Document 1 does not take this into consideration. As a result, the timing for cleaning the pressing member cannot be determined appropriately.

[0006] The present disclosure has been made to solve the above-mentioned problems, and its purpose is to provide a post-processing device that can appropriately determine the timing for cleaning the pushing member. [Means for solving the problem]

[0007] According to one aspect, a post-processing device that performs post-processing on sheets includes a tray for storing the sheets, a pushing member that receives power and pushes the sheets into the tray, and a control unit that determines whether or not the pushing member needs to be cleaned based on the current value required to drive the pushing member.

[0008] Preferably, the control unit determines whether cleaning is necessary based on the amount of change from a reference value of a target parameter value, which is either a current value or a converted value obtained by converting the current value.

[0009] Preferably, the control unit determines that cleaning is necessary when a first condition is satisfied, that is, the difference between the reference value and the target parameter value exceeds a first threshold, or a second condition is satisfied, that is, the ratio of the target parameter value to the reference value is less than a second threshold.

[0010] Preferably, the tray includes a stopper 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 drive unit that receives power and rotates the rotating member. The current value is a measurement of the current supplied to the drive unit.

[0011] Preferably, the rotating member comprises a paddle or a belt. Preferably, the tray includes a stopper 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 drive unit that receives power and rotates the rotating member. The converted value is a value of torque for rotating the rotating member.

[0012] Preferably, the control unit disables the process of determining whether cleaning is necessary when the number of sheets accommodated in the tray exceeds a reference number.

[0013] Preferably, the post-processing device further includes a receiving unit that receives a selection between a first mode and a second mode. The tray contains a plurality of sheets on which images are formed by executing print jobs. In response to the receiving unit receiving the selection of the first mode, the control unit determines whether cleaning is necessary for each print job using a current value measured when each of the plurality of sheets is pushed in. In response to the receiving unit receiving the selection of the second mode, the control unit determines whether cleaning is necessary for each print job using only a current value measured when the first sheet of the plurality of sheets is pushed in.

[0014] Preferably, the control unit corrects the target parameter value by an amount of correction associated with deformation of the pushing member when the number of sheets accommodated in the tray exceeds a reference number.

[0015] Preferably, the control unit determines the amount of correction in accordance with at least one of the type of sheet, the type of image printed on the sheet, and image forming conditions.

[0016] Preferably, the control unit determines the reference number of sheets in accordance with at least one of the type of sheet, the type of image printed on the sheet, and the image forming conditions.

[0017] Preferably, the image forming conditions indicate either single-sided printing or double-sided printing. Preferably, the control unit calculates the time during which the pressing member is in contact with the sheet based on a change in the current value, and increases the amount of correction as the time is longer.

[0018] Preferably, the control unit outputs a notification prompting replacement or cleaning of the pushing member in response to determining that cleaning is necessary.

[0019] Preferably, the drive unit increases the rotation speed of the rotary member in response to the control unit determining that cleaning is required. [Effects of the Invention]

[0020] According to the present disclosure, the timing for cleaning the pushing member can be appropriately determined. [Brief explanation of the drawings]

[0021] [Figure 1] 1 shows the appearance of a multifunction peripheral equipped with a post-processing device according to a first embodiment. [Figure 2] 3A and 3B are diagrams showing a pushing member and its surrounding configuration. [Figure 3] FIG. 2 is a diagram illustrating a functional configuration of a control unit according to the first embodiment. [Figure 4] 10A and 10B are diagrams illustrating an example of a measurement result of a current value by a current measuring unit. [Figure 5] 10 is a diagram showing the change in the current value when the paddle is in contact with the paper and the amount of foreign matter adhering to the pressing member with respect to the cumulative number of sheets after a new pressing member is installed. [Figure 6] 5 is a flowchart showing the flow of processing by a control unit according to the first embodiment. [Figure 7] FIG. 10 is a diagram showing an example of a screen for selecting either a first mode or a second mode. [Figure 8] 10A and 10B are diagrams illustrating the state of the pushing member when there are a large number of sheets on the alignment tray. [Figure 9] FIG. 11 is a diagram illustrating a functional configuration of a control unit according to the third embodiment. [Figure 10] 11 is a flowchart showing the flow of processing by a control unit according to the third embodiment. [Figure 11] FIG. 10 is a diagram illustrating a functional configuration of a control unit according to the fourth embodiment. [Figure 12] FIG. 10 is a diagram illustrating a first calculation method of a correction amount. [Figure 13] 10 is a flowchart showing the flow of processing by a control unit according to the fourth embodiment when a first calculation method is applied. [Figure 14] FIG. 10 is a diagram showing a first table used to determine a variable c. [Figure 15] FIG. 10 is a diagram showing a second table used to determine the variable c. [Figure 16] 10 is a flowchart showing the flow of processing by a control unit according to the fourth embodiment when a second calculation method is applied. [Figure 17] 13A and 13B are diagrams illustrating the operation of a pushing member provided in the post-processing device according to the fifth embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0022] Hereinafter, a post-processing device according to an embodiment of the present disclosure will be described with reference to the drawings. In the following description, the same parts and components are denoted by the same reference numerals. Their names and functions are also the same. Therefore, detailed descriptions thereof will not be repeated. Note that the embodiments and modifications described below may be selectively combined as appropriate.

[0023] [Embodiment 1] <Overall structure> FIG. 1 shows the appearance of a multifunction peripheral equipped with a post-processing device according to embodiment 1. As shown in FIG. 1, the multifunction peripheral 1 includes a scanner 2, a printer unit 3, a post-processing device 10, and an operation panel 40. The printer unit 3 includes an image forming unit 5, a paper feed unit 6, a fixing unit 8, and a pair of discharge rollers 9. The printer unit 3 further includes a main body control unit 150 that controls the operation of the printer unit 3. The operation panel 40 accepts operations by the user.

[0024] The main body control unit 150 controls each component of the printer unit 3 in accordance with a print job received by the operation panel 40. The print job specifies image data, image formation conditions, paper type, number of copies, post-processing conditions, etc. The main body control unit 150 includes, for example, a CPU (Central Processing Unit), ROM (Read Only Memory), RAM (Random Access Memory), and non-volatile memory. The CPU controls the operation of the printer unit 3 by expanding and executing programs stored in the non-volatile memory on the RAM, and outputs operating instructions to the post-processing device 10. Furthermore, the main body control unit 150 may also include dedicated hardware circuits.

[0025] The paper feed unit 6 stores sheets (hereinafter referred to as "paper"). The paper feed unit 6 supplies the paper one by one to a conveyance path 7. 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 a post-processing device 10 by a pair of discharge rollers 9.

[0026] The image forming unit 5 forms a toner image on paper using a well-known electrophotographic method in accordance with a print job. For example, the image forming unit 5 forms a toner image on paper that corresponds to an original image optically read by the scanner 2 or image data transferred from a computer (not shown). The fixing unit 8 fixes the toner image on the paper.

[0027] Although post-processing device 10 is capable of various post-processing operations such as stapling, punching, and folding, it will be described here as a device that performs stapling. Post-processing device 10 includes a pair of receiving rollers 11, pairs of conveying rollers 12-14, a guide plate 15, an electric stapler 16, an alignment tray 20, a push-in member 22, a discharge tray 30, and a control unit 100.

[0028] The paper sheets discharged from the discharge roller pair 9 are introduced into the post-processing device 10 by the receiving roller pair 11. In the post-processing device 10, the paper sheets are transported in the direction of arrow A by the transport roller pair 12, 13, and fed one by one onto the alignment tray 20 by the transport roller pair 14, where they are aligned by the pushing member 22. As a result, a predetermined number of sheets are stacked on the alignment tray 20 in an aligned state.

[0029] The electric stapler 16, which operates as a post-processing section, staples the end of a stack of a predetermined number of sheets.

[0030] Discharge rollers 31a and 31b discharge the stapled stack of sheets from alignment tray 20 onto discharge tray 30. Normally, discharge roller 31b is positioned apart from discharge roller 31a, presses the stack of sheets against discharge roller 31a to fix the stack of sheets, and rotates to discharge the stack of sheets onto discharge tray 30.

[0031] The control unit 100 controls the operation of the post-processing device 10. The control unit 100 includes, for example, a CPU, a ROM, a RAM, and a non-volatile memory. The CPU controls the operation of the post-processing device 10 by expanding a program stored in the non-volatile memory onto the RAM and executing it. Furthermore, the control unit 100 may include a dedicated hardware circuit.

[0032] <Paper alignment method> A method for aligning sheets in the alignment tray 20 will be described with reference to Fig. 2. Fig. 2 is a diagram showing a pushing member and its peripheral configuration.

[0033] 2, alignment tray 20 is installed at an angle so as to rise in the storage direction indicated by arrow B. Alignment tray 20 includes a reference stopper 21 for aligning stored paper sheets P at its lower end, i.e., the end in the opposite direction to arrow B (hereinafter referred to as alignment direction B').

[0034] 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 drive unit 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. Below, a rotating member 26 having two paddles 24 will be described. However, the rotating member 26 may have only one paddle 24, or may have three or more paddles 24.

[0035] 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. Note that the drive unit 25 may be configured with a drive transmission mechanism such as a clutch or solenoid instead of a motor. The drive unit 25 rotates the support shaft 23 so that the direction of movement of the point on the circumferential surface of the support shaft 23 that is closest to the upper surface of the alignment tray 20 coincides with the alignment direction B'.

[0036] The two paddles 24 are attached at a predetermined interval around the support shaft 23. As the support shaft 23 rotates, each paddle 24 comes into contact with the top sheet P on the alignment tray 20. At this time, a frictional force is generated between the paddle 24 and the sheet P. The paddle 24 uses this frictional force to push the sheet P in the alignment direction B'. That is, as sheets P are fed one by one from the transport roller pair 14 onto the alignment tray 20, the two paddles 24 come into contact with the sheet P in turn and apply a force in the alignment direction B' to the sheet P. As a result, the sheet P moves until its leading edge in the alignment direction B' abuts against the reference stopper 21, where it is aligned.

[0037] Furthermore, a pair of alignment plates (not shown) for aligning the sheets P in the width direction may be installed on the alignment tray 20. Each time a sheet P is stored on the alignment tray 20, the alignment plates move in a direction perpendicular to the storing direction B to a position corresponding to the width size of the sheet P, thereby aligning the sheet P in the width direction.

[0038] In this way, before being stapled, the sheets stored on the alignment tray 20 are aligned. Then, the aligned sheets are stapled by the electric stapler 16.

[0039] <Functional configuration of the control unit> The control unit 100 determines whether cleaning of the pushing member 22 is necessary based on the current value required to drive the pushing member 22.

[0040] 3 is a diagram showing the functional configuration of a control unit according to embodiment 1. As shown in FIG. 3, control unit 100 includes current measurement unit 101, change amount calculation unit 102, determination unit 103, and notification unit 104.

[0041] The current measuring unit 101 measures the value of the current required to drive the pushing member 22. Specifically, the current measuring unit 101 measures the value of the current supplied to the driving unit 25 of the pushing member 22.

[0042] 4 is a diagram showing an example of the measurement results of the current value by the current measurement unit. As shown in Fig. 4, during periods t0, t1, ... when any of the paddles 24 is in contact with the paper P, the current value required to drive the pushing member 22 increases. This is because when the paddle 24 comes into contact with the paper P, frictional force is generated between the paddle 24 and the paper P, and the power required to rotate the rotating member 26 increases.

[0043] The current measurement unit 101 can identify periods t0, t1, ... during which any of the paddles 24 is in contact with the paper P by comparing 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. The current measurement unit 101 can identify periods t0, t1, ... during which any of the paddles 24 is in contact with the paper P. k Current value I for (k=0,1,...) k Identify.

[0044] The current measurement unit 101 measures the period t during which any one of the paddles 24 is in contact with the sheet P for each sheet P. m ,···,t m+p(m and p are integers greater than or equal to 0) m ,···,I m+p The current measuring section 101 calculates a representative value of the currents (hereinafter referred to as a “representative current value”). The current measuring section 101 outputs the calculated representative value to the change amount calculating section 102.

[0045] The method for calculating the representative current value is not particularly limited. For example, the current measurement unit 101 calculates the current value I m ,···,I m+p The average value of (=(I m +I m+1 +···+I m+p ) / (p+1)) as the representative current value. Alternatively, the current measuring unit 101 calculates the current value I m ,···,I m+p Alternatively, the current measuring unit 101 may calculate the maximum value of the current value I as the representative current value. m ,···,I m+p Alternatively, the average value of (p+1-2q) current values ​​excluding a predetermined number (q) of the top values ​​and a predetermined number (q) of the bottom values ​​may be calculated as the representative current value.

[0046] 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.

[0047] FIG. 5 shows the change in the current value when the paddle is in contact with paper and the amount of foreign matter adhering to the pushing member relative to the cumulative number of sheets since a new pushing member was installed. 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 measurement unit 101, and the right vertical axis represents the amount of foreign matter adhering to the paddle 24 of the pushing member 22. The foreign matter includes toner, oil, and paper dust. Line 51 represents the change in the representative current value, and line 52 represents the amount of foreign matter adhering.

[0048] When the paddle 24 and the paper P are in contact with each other, toner, paper dust, and oil may adhere to the paddle 24. Therefore, as shown in FIG. 5, as the cumulative number of sheets of paper P pushed by the pushing member 22 increases, the amount of foreign matter adhering to the paddle 24 of the pushing member 22 increases.

[0049] The torque for rotating the paddle 24 is expressed by the following equation (1). Torque = F × r =μ×N×r Equation (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 to the paper, and r is the distance between the tip of the paddle 24 and the center of the support shaft 23.

[0050] When foreign matter adheres to the paper P, the coefficient of friction μ between the paddle 24 and the paper P decreases. As a result, the torque for rotating the paddle 24 also decreases. The current value supplied to the drive unit 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.

[0051] The change amount calculation unit 102 calculates the amount of change in the representative current value from the reference value as a parameter indirectly representing the amount of foreign matter adhering to the paddle 24. The change amount calculation unit 102 uses the representative current value output from the current measurement unit 101 as the reference value when no foreign matter is adhering to the paddle 24 or when the amount of foreign matter adhering to the paddle 24 is small. For example, the change amount calculation unit 102 sets as the reference value a value (e.g., an average value, a median value, an average value excluding outliers, etc.) calculated from the representative current values ​​for a predetermined number (s) of sheets of paper P after the push-in member 22 is newly installed, replaced, or cleaned. The change amount calculation unit 102 calculates the difference between the reference value and the representative current value output from the current measurement unit 101 (reference value - representative current value) as the amount of change.

[0052] The determination unit 103 determines whether cleaning of the pushing member 22 is necessary 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 value.

[0053] The notification unit 104 outputs a notification according to the determination result of the determination unit 103. Specifically, in response to the determination that cleaning is necessary, the notification unit 104 displays a notification screen on the operation panel 40 (see FIG. 1) that prompts the user to replace or clean the pushing member 22.

[0054] <Processing flow of the control unit> 6 is a flowchart showing the flow of processing by the control unit according to embodiment 1. First, the control unit 100 measures the current value required to drive the pushing member 22 (step S1). For example, the control unit 100 measures the above-mentioned representative current value for each sheet P.

[0055] Next, the control unit 100 calculates the amount of change in the current value relative 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.

[0056] Next, the control unit 100 determines whether the amount of change exceeds a threshold value (step S3). If the amount of change exceeds the threshold value (YES in step S3), the control unit 100 outputs a notification prompting cleaning (step S4). If the amount of change does not exceed the threshold value (NO in step S3) or after step S4, the control unit 100 ends the process.

[0057] As described above, post-processing device 10 according to the first embodiment performs post-processing on sheets P. Post-processing device 10 includes alignment tray 20 that stores sheets P, pushing member 22 that receives power and pushes sheets P into the alignment tray, and control unit 100 that determines whether pushing member 22 needs to be cleaned based on the current value required to drive pushing member 22.

[0058] 5, the current value required to drive the pushing member 22 correlates with the amount of foreign matter attached. Therefore, the control unit 100 can accurately determine whether cleaning of the pushing member 22 is necessary by using the current value required to drive the pushing member 22. As a result, the post-processing device 10 can appropriately determine the timing to clean the pushing member 22.

[0059] The control unit 100 determines whether cleaning is necessary based on the amount of change in the current value (specifically, the representative current value described above) from a reference value. When no foreign matter is attached to the pushing member 22 or when the amount of foreign matter attached to the pushing member 22 is small, the representative current value output from the current measurement unit 101 may vary depending on individual differences between the pushing members 22. By using the amount of change described above, the influence of individual differences between the pushing members 22 is eliminated. Therefore, whether cleaning of the pushing member 22 is necessary can be determined with high accuracy, regardless of individual differences between the pushing members 22.

[0060] Specifically, the 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. This allows the control unit 100 to determine whether cleaning is necessary through relatively simple calculation processing.

[0061] The alignment tray 20 includes a reference stopper 21 for aligning the stored paper sheets P. The pushing member 22 includes a rotating member 26 that contacts the paper sheets P and moves them toward the reference stopper 21, and a drive unit 25 that receives power and rotates the rotating member 26. The current value is a measured value of the current supplied to the drive unit 25. The current value supplied to the drive unit 25 correlates with the torque required to rotate the rotating member 26 when the rotating member 26 is in contact with the paper sheets P. This torque depends on the amount of foreign matter adhering to the rotating member 26. Therefore, the amount of foreign matter adhering to the pushing 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 the pushing member 22 needs to be cleaned.

[0062] In response to determining that cleaning is necessary, the control unit 100 outputs a notification urging the user to replace or clean the pushing member 22. This allows the user to check the notification and replace or clean the pushing member 22 at an appropriate time.

[0063] [Embodiment 2] The post-processing device according to the second embodiment differs from post-processing device 10 according to the first embodiment in that either a first mode or a second mode is selected as the mode for determining whether cleaning is necessary. In the first mode, a determination is made as to whether cleaning is necessary each time a plurality of sheets P on which an image has been formed by the execution of a print job by image forming unit 5 is placed in alignment tray 20. In the second mode, a determination is made as to whether cleaning is necessary only when the first sheet P of the plurality of sheets P on which an image has been formed by the execution of a print job is placed in alignment tray 20.

[0064] It usually takes a long time for enough foreign matter to adhere to the pushing member 22 to reduce the conveying force of the paper P. Therefore, by selecting the second mode, the load on the control unit 100 is reduced.

[0065] 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. Operation panel 40 operates as a reception unit that receives the selection of the first mode or the second mode.

[0066] Fig. 7 is a diagram showing an example of a screen for selecting either the first mode or the second mode. Screen 200 shown in Fig. 7 is displayed on operation panel 40 and includes radio buttons 201 and 202. The user presses radio button 201 to select the first mode, and radio button 202 to select the second mode.

[0067] In response to operation panel 40 accepting selection of the first mode, control unit 100 determines, for each print job, whether cleaning is required using the current value measured when each of multiple sheets of paper P on which an image is formed by executing the print job is pushed in. That is, current measurement unit 101 of control unit 100 outputs a representative current value measured for each sheet of paper P. Determination unit 103 compares the amount of change in the representative current value relative to a reference value with a threshold value for each sheet of paper P, and determines whether cleaning is required based on the comparison result.

[0068] In response to operation panel 40 accepting selection of the second mode, control unit 100 determines whether cleaning is necessary for each print job using only the current value measured when pushing in the first sheet of paper P out of multiple sheets of paper P on which an image is formed by executing that print job. That is, current measurement unit 101 of control unit 100 outputs a representative current value only for the first sheet of paper P. Determination unit 103 compares the amount of change in the representative current value relative to the reference value with a threshold value for the first sheet of paper P, and determines whether cleaning is necessary based on the comparison result.

[0069] [Embodiment 3] 8 is a diagram showing the state of the pushing member when there are many sheets of paper on the alignment tray 20. As shown in FIG. 8, when there are many sheets of paper P on the alignment tray 20, 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 drive unit 25 also increases. The increase in the current value due to the deformation of the paddle 24 may make it difficult to accurately determine whether the pushing member 22 needs to be cleaned.

[0070] Therefore, the post-processing device according to the third embodiment omits the determination of whether or not cleaning of the pushing member 22 is necessary when the number of sheets P on the alignment tray 20 exceeds the reference number R. The reference number R is the number of sheets of plain paper (basis weight 60 to 90 g / m) on which character images are printed. 2) are accommodated in the alignment tray 20, the reference number R indicates the number at which the value of the current supplied to the drive unit 25 starts to increase as the paddle 24 deforms. The reference number R is determined in advance by experiment or the like.

[0071] Fig. 9 is a diagram showing the functional configuration of a control unit according to embodiment 3. The post-processing device according to embodiment 3 differs from post-processing device 10 of embodiment 1 in that it includes a control unit 100A shown in Fig. 9 instead of control unit 100.

[0072] The control unit 100A differs from the control unit 100 according to the first embodiment in that it includes a storage number management unit 105.

[0073] The storage number management unit 105 manages the number of sheets P stored in the alignment tray 20 (hereinafter referred to as the "storage number"). The storage number management unit 105 has a counter, and increases the counter value by 1 each time a sheet P is discharged from the discharge roller pair 9. The storage number management unit 105 resets the counter value to 0 when post-processing is performed by the electric stapler 16 and the post-processed sheet stack is discharged to the discharge tray 30 by the discharge rollers 31a, 31b. As a result, the counter value of the storage number management unit 105 represents the storage number.

[0074] The stored sheet count management unit 105 disables the process of determining whether cleaning is necessary when the counter value (i.e., the stored sheet count) exceeds the reference sheet count R. That is, the stored sheet count management unit 105 disables the operation of the change amount calculation unit 102 and the determination unit 103. As a result, when the stored sheet count exceeds the reference sheet count R, the determination of whether cleaning of the pushing member 22 is necessary is omitted.

[0075] Fig. 10 is a flowchart showing the flow of processing by the 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.

[0076] In step S11, the control unit 100A determines whether the number of stored sheets exceeds the reference number R. If the number of stored sheets exceeds the reference number R (YES in step S11), the control unit 100A ends the process. If the number of stored sheets does not exceed the reference number R (YES in step S11), the control unit 100A proceeds to step S2.

[0077] According to the third embodiment, it is possible to avoid the situation where an increase in the current value accompanying the deformation of the paddle 24 makes it impossible to accurately determine whether or not the pushing member 22 needs to be cleaned.

[0078] [Embodiment 4] The post-processing device 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. This allows the post-processing device to accurately determine whether or not cleaning of the pushing member 22 is necessary, using the current value from which the influence of the deformation of the rotating member 26 has been removed.

[0079] Fig. 11 is a diagram showing the functional configuration of a control unit according to embodiment 4. The post-processing device according to embodiment 4 differs from the post-processing device according to embodiment 3 in that it includes a control unit 100B shown in Fig. 11 instead of control unit 100A.

[0080] Control unit 100B differs from control unit 100A according to the third embodiment in that it includes correction unit 106. Note that, similar to the third embodiment, storage number management unit 105 according to the fourth embodiment manages the number of sheets P stored in alignment tray 20 (storage number). However, when the counter value (i.e., the storage number) exceeds reference number R, storage number management unit 105 according to the fourth embodiment disables the operations of change amount calculation unit 102 and determination unit 103, and instead outputs a correction instruction to correction unit 106.

[0081] When the correction unit 106 receives a correction instruction from the storage number management unit 105, it corrects the current value output from the current measurement unit 101 by the amount of correction associated with the deformation of the rotating member 26. The method of calculating the amount of correction will be described below.

[0082] (First calculation method of correction amount) Fig. 12 is a diagram illustrating a first calculation method for the correction amount. Fig. 12 shows the change in current value when the number of sheets stored is increased when there is no foreign matter attached to paddle 24 or when the amount of foreign matter attached is small. Fig. 12 shows the contact times T_1, T_u, and T_v between paddle 24 and paper and the current values ​​I_1, I_u, and I_v supplied to drive unit 25 when the number of sheets stored is 1, u (u>1), and v (v>u), respectively.

[0083] As shown in FIG. 12, as the number of sheets stored increases, the contact time between the paddle 24 and the paper P becomes longer. This is because the paddle 24 deforms (see FIG. 8). As the paddle 24 deforms, the frictional force between the paddle 24 and the paper P increases, and the current value supplied to the drive unit 25 increases. Therefore, as the number of sheets stored increases, the current value supplied to the drive unit 25 increases. The correction unit 106 calculates a correction amount to remove the influence of this number of sheets stored.

[0084] The correction unit 106 stores in advance information indicating the correlation between the differences ΔT_k and ΔI_k between the contact time T_1 and current value I_1 when the number of sheets accommodated is one, and the contact time T_k and current value I_k when the number of sheets accommodated is k (k is an integer equal to or greater than 1). This information is created in advance through experiments or the like. That is, this information is generated based on (ΔT_1, ΔI_1), (ΔT_2, ΔI_2), ... obtained through experiments. This information may represent, for example, a function or a table.

[0085] As described in the first embodiment, the current measurement unit 101 identifies the periods t0, t1, ... during which any one of the paddles 24 is in contact with the paper. The correction unit 106 calculates the current for each of the identified periods t k ,t k+1,... (hereinafter referred to as "average contact time T"). The correction unit 106 calculates the difference ΔT (=T-T_1) between the average contact time T and the contact time T_1 when the number of sheets accommodated is one. The correction unit 106 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.

[0086] The 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 the current measurement unit 101.

[0087] 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 it includes steps S21 and S22.

[0088] If the number of sheets accommodated does not exceed the reference number R (YES in step S11), control unit 100B proceeds to step S21. In step S21, control unit 100B calculates the difference ΔT (=T - T_1) between the average contact time T between paddle 24 and paper P and the contact time T_1 when the number of sheets accommodated is one. Then, control unit 100B uses the correlation information to calculate a difference ΔI corresponding to the calculated difference ΔT as a correction amount associated with the deformation of paddle 24.

[0089] Next, the control unit 100B corrects the representative current value by subtracting the correction amount from the representative current value output from the current measurement unit 101 (step S22). After step S22, the control unit 100B moves the process to step S2.

[0090] (Second method for calculating the correction amount) The second calculation method is a method of calculating the correction amount according to the type of paper P (paper grade), the type of image printed on the paper P (photo, text), and the image formation conditions.

[0091] 11, the control unit 100B receives paper type information indicating the paper type and printing condition information indicating the printing conditions (image type and formation conditions) from the main body control unit 150 (see FIG. 1) of the printer unit 3. The image formation conditions indicate either double-sided printing or single-sided printing.

[0092] The correction unit 106 calculates the amount of correction according to the following equation (2). Correction amount = a × (N COUNT -c) ···Formula (2) In equation (2), a is a predetermined constant. COUNT is the number of sheets of paper P stored in the alignment tray 20 (the number of stored sheets), and is the value of a counter in the stored sheet number management unit 105. c is a variable determined according to the type of paper P (paper type), the type of image to be printed on the paper P (photo, text), and the image formation conditions.

[0093] Fig. 14 is a diagram showing a first table used to determine the variable c. The correction unit 106 stores the first table shown in Fig. 14 in advance. As shown in Fig. 14, the first table associates whether or not the paper type is taken into consideration, the paper type, and the amount of increase or decrease from the reference number of sheets R.

[0094] Fig. 15 is a diagram showing a second table used to determine the variable c. The correction unit 106 stores in advance the first table shown in Fig. 15. 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 of sheets R.

[0095] The operation panel 40 receives from the user whether or not to take into consideration the paper type and printing conditions. For example, the operation panel 40 receives whether or not to take into consideration the paper type and printing conditions during the initial setup of the multifunction device 1. The correction unit 106 stores information indicating the content received by the operation panel 40.

[0096] When the correction unit 106 does not take the paper type into consideration, it reads out the increase / decrease amount corresponding to "paper type not considered" from the first table shown in Fig. 14. When the correction unit 106 takes the paper type into consideration, it reads out the increase / decrease amount corresponding to the paper type from the first table shown in Fig. 14.

[0097] When the printing conditions are not taken into consideration, the correction unit 106 reads out the increase / decrease amount corresponding to "no consideration of printing conditions" from the second table shown in Fig. 15. When the printing conditions are taken into consideration, the correction unit 106 reads out the increase / decrease amount corresponding to the printing conditions from the second table shown in Fig. 15.

[0098] The correction unit 106 sets the variable c to a value obtained by adding the sum of the increase / decrease in the readout amount to the reference number R. The correction unit 106 calculates the variable c and the current number N of sheets accommodated. COUNT The correction amount is calculated by substituting and into the above formula (2).

[0099] 14 and 15, the increase / decrease amount when the paper type and printing conditions are not taken into consideration is set to "0." Therefore, when the paper type and printing conditions are not taken into consideration, the correction unit 106 determines the reference number of sheets R as the value of the variable c.

[0100] 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 it includes steps S31 to S34 instead of step S21.

[0101] If the number of stored sheets does not exceed the reference number R (YES in step S11), control unit 100B proceeds to step S31. In step S31, control unit 100B determines whether to take into account the paper type and printing conditions. Control unit 100B may determine whether to take into account the paper type and printing conditions based on information indicating the content received by operation panel 40.

[0102] If neither the paper type nor the printing conditions are taken into consideration (NO in step S31), control unit 100B determines reference number of sheets R as the value of variable c (step S32).

[0103] When at least one of the paper type and the printing conditions is taken into consideration (YES in step S31), control unit 100B determines the value of variable c using the first table shown in FIG. 14 and the second table shown in FIG. 15 (step S33).

[0104] After steps S32 and S33, the control unit 100B calculates the value of the variable c and the current number of sheets stored N COUNT The correction amount is calculated by substituting the above equation (2) (step S34). Thereafter, the control unit 100B moves the process to step S22.

[0105] (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 × (N COUNT -c)×b ···Equation (3) b is a coefficient determined according to the shape and material of the pushing member 22 .

[0106] When the pushing member 22 is attached to the post-processing device 10, the value of the coefficient b according 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.

[0107] (Fourth method for calculating the 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 of paper pushed by the pushing member 22 (hereinafter referred to as the "cumulative number of processed sheets"). Note that the coefficient b may be fixed to "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.

[0108] Depending on the shape and material of the pushing member 22, it is possible that the deformed state may be maintained over a long period of use. Maintaining the deformed state may reduce the normal force between the paddle 24 and the paper. Therefore, the correction unit 106 presets an upper limit on the cumulative number of sheets that can be used, which is determined taking into consideration the durability of the pushing member 22. The correction unit 106 determines the coefficient d according to the ratio of the current cumulative number of processed sheets to the upper limit. For example, the correction unit 106 determines the value of coefficient d to be "1.01" when the ratio is 50% or less, "1" when the ratio is 51% to 80%, and "0.99" when the ratio is 81% or more.

[0109] [Embodiment 5] 17 is a diagram showing the operation of a pushing member provided in the post-processing device according to embodiment 5. The post-processing device according to embodiment 5 differs from the post-processing devices according to embodiments 1 to 4 in that it includes pushing member 22A shown in FIG.

[0110] 17, the pushing member 22A includes a driving unit 25A and a rotating member A. The rotating member A includes a fixed roller 121, a movable roller 122, a connecting rod 123, and a belt .

[0111] The shaft of fixed roller 121 is installed at a fixed position. The shaft of movable roller 122 is rotatable around the shaft of fixed roller 121. Connecting rod 123 rotatably supports the shafts of fixed roller 121 and movable roller 122 so as to maintain a constant distance between the shafts of fixed roller 121 and movable roller 122. Therefore, movable roller 122 moves in an arc shape centered on fixed roller 121. Belt 124 is suspended between fixed roller 121 and movable roller 122.

[0112] The driving unit 25A rotates the fixed roller 121. The driving unit 25A is, for example, a motor. The driving unit 25A may be configured with a drive transmission mechanism such as a clutch or a solenoid instead of a motor. The rotation of the fixed roller 121 by the driving unit 25A causes the belt 124 to rotate in the direction of arrow D.

[0113] When no paper is stored in the alignment tray 20, the movable roller 122 is locked in the retracted position by a locking mechanism (not shown) (see the upper part of Figure 17). When the alignment tray 20 is filled with paper P, the locking mechanism is released, and the movable roller 122 moves down by its own weight and comes into contact with the paper 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.

[0114] 17, the height of the movable roller 122 varies depending on the number of sheets P on the alignment tray 20. Therefore, the contact area and normal force between the belt 124 and the sheets P are approximately constant regardless of the number of sheets on the alignment tray 20.

[0115] [Variations] In the above-described first to fifth embodiments, the post-processing device is equipped with the control units 100, 100A, and 100B. However, the control units 100, 100A, and 100B may be integrated with the main body control unit 150 of the printer unit 3. In this case, the multifunction device 1 is regarded as a post-processing device equipped with the alignment tray 20 that stores sheets of paper, the pushing members 22 and 22A that receive power and push the sheets of paper P into the alignment tray 20, and the control units 100, 100A, and 100B that determine whether cleaning of the pushing members 22 and 22A is required based on the current value required to drive the pushing members 22 and 22A.

[0116] In the above-described first to fifth embodiments, the change amount calculation unit 102 calculates the difference between the reference value and the representative current value output from the current measurement unit 101 (reference value-representative current value) as the amount of change. However, the change amount calculation unit 102 may also calculate the ratio of the representative current value to the reference value (representative current value / reference value) as the amount of change. In this case, the determination unit 103 may determine that cleaning is necessary when a condition is met whereby the ratio (representative current value / reference value) is less than a predetermined threshold value.

[0117] As described above, the value of the current supplied to drive unit 25 correlates with the value of the torque for rotating rotating member 26. Therefore, change amount calculation unit 102 may convert the representative current value output from current measurement unit 101 into a value of the torque for rotating rotating member 26. Then, change amount calculation unit 102 may calculate the amount of change in the converted value relative to a reference value. In this case, the reference value is the value of the torque for rotating rotating members 26, 26A when no foreign matter is attached to rotating members 26, 26A or when the amount of foreign matter attached to rotating members 26, 26A is small.

[0118] When determining that cleaning is necessary by determining unit 103, driving units 25, 25A may increase the rotation speed of rotating members 26, 26A. This increases the driving force that moves paper P to reference stopper 21, and prevents misalignment of paper P, even if the frictional force between rotating members 26, 26A and paper is reduced due to foreign matter adhering to rotating members 26, 26A.

[0119] 10, 13, and 16, steps S31 to S33 shown in Fig. 16 may be executed before step S11, and step S11 may be executed using the value of variable c determined in steps S32 and S33 as the reference number of sheets. 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 paper P, and the image formation conditions. This allows the reference number to be appropriately changed according to the type of paper P, the type of image printed on paper P, and the image formation conditions.

[0120] The embodiments disclosed herein should be considered to be illustrative in all respects and not restrictive. The scope of the present invention is defined by the claims, not by the above description, and is intended to include all modifications within the meaning and scope of the claims. [Explanation of symbols]

[0121] 1 multifunction device, 2 scanner, 3 printer section, 5 image forming unit, 6 paper feed unit, 7 transport path, 8 fixing unit, 9 discharge roller pair, 10 post-processing device, 11 receiving roller pair, 12, 13, 14 transport roller pair, 15 guide plate, 16 electric stapler, 20 alignment tray, 21 reference stopper, 22, 22A pushing member, 23 support shaft, 24 paddle, 25, 25A drive section, 26, 26A rotating member, 30 discharge tray, 31a, 31b discharge roller, 40 operation panel, 100, 100A, 100B control section, 101 current measurement section, 102 change amount calculation section, 103 judgment section, 104 notification section, 105 storage number management section, 106 correction section, 121 fixed roller, 122 movable roller, 123 Connecting rod, 124 Belt, 150 Main unit control section, 200 Screen, 201, 202 Radio buttons.

Claims

1. A post-processing device that performs post-processing on a sheet, a tray in which the sheets are stored; a pushing member that receives power and pushes the sheet into the tray; a control unit that determines whether cleaning of the pushing member is necessary based on a current value required to drive the pushing member; a reception unit that receives a selection between the first mode and the second mode, The tray accommodates a plurality of sheets on which images are formed by the execution of a print job, The control unit In response to the reception unit receiving the selection of the first mode, for each print job, the current value measured when each of the plurality of sheets is pushed in is used to determine whether the cleaning is necessary; In response to the reception unit receiving the selection of the second mode, the post-processing device determines whether cleaning is necessary for each print job using only the current value measured when pushing in the first sheet of the multiple sheets.

2. A post-processing device that performs post-processing on a sheet, a tray in which the sheets are stored; a pushing member that receives power and pushes the sheet into the tray; a control unit that determines whether cleaning of the pushing member is necessary based on a current value required to drive the pushing member, the control unit determines whether the cleaning is necessary based on an amount of change from a reference value of a target parameter value, which is either the current value or a converted value obtained by converting the current value; 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 a reference number.

3. A post-processing device that performs post-processing on a sheet, a tray in which the sheets are stored; a pushing member that receives power and pushes the sheet into the tray; a control unit that determines whether cleaning of the pushing member is necessary based on a current value required to drive the pushing member, the control unit disables the process of determining whether cleaning is necessary when the number of sheets accommodated in the tray exceeds a reference number; The control unit determines the reference number of sheets in accordance with at least one of the type of the sheet, the type of image printed on the sheet, and a forming condition of the image.

4. The post-processing device according to claim 1 or 3, wherein the control unit determines whether the cleaning is necessary based on an amount of change from a reference value of a target parameter value, which is either the current value or a converted value obtained by converting the current value.

5. 5. The post-processing device according to claim 2, wherein the control unit determines that the cleaning is necessary when a first condition is satisfied, that is, a difference between a reference value and the target parameter value exceeds a first threshold, or a second condition is satisfied, that is, a ratio of the target parameter value to the reference value is less than a second threshold.

6. the tray includes a stopper for aligning the sheets stored therein; The pushing member is a rotating member that comes into contact with the sheet and moves the sheet toward the stopper; a drive unit that receives the electric power and rotates the rotary member, The post-processing device according to claim 1 , wherein the current value is a measured value of a current supplied to the drive unit.

7. The aftertreatment device of claim 6 , wherein the rotating member includes a paddle or a belt.

8. the tray includes a stopper for aligning the sheets stored therein; The pushing member is a rotating member that comes into contact with the sheet and moves the sheet toward the stopper; a drive unit that receives the electric power and rotates the rotary member, The post-processing device according to claim 5 , wherein the converted value is a torque value for rotating the rotary member.

9. The post-processing device according to claim 1 , wherein the control unit disables the process of determining whether cleaning is necessary when the number of sheets accommodated in the tray exceeds a reference number.

10. The post-processing device according to claim 2 , wherein the control unit determines the correction amount in accordance with at least one of the type of the sheet, the type of image printed on the sheet, and a forming condition of the image.

11. The post-processing device according to claim 2 , wherein the control unit determines the reference number of sheets in accordance with at least one of the type of the sheet, the type of image printed on the sheet, and a forming condition of the image.

12. The post-processing device according to claim 10 or 11, wherein the image forming conditions indicate either single-sided printing or double-sided printing.

13. The control unit calculating a time during which the pressing member is in contact with the sheet based on the change in the current value; The post-processing device according to claim 2 , wherein the correction amount is increased as the time period is longer.

14. The post-processing device according to claim 1 , wherein the control unit outputs a notification prompting the user to replace or clean the pushing member in response to determining that the cleaning is necessary.

15. The post-processing device according to claim 6 , wherein the drive unit increases the rotation speed of the rotating member in response to the control unit determining that the cleaning is necessary.

Images