JP2018099790A - Image formation apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress reduction in the productivity (printing speed) of an image formation apparatus by making the sheet feeding start interval between copies at the stapling shorter than that of the conventional technique.SOLUTION: An image formation apparatus includes a printing unit, a sheet feeding unit, a printing control unit, and a post-processor. The post-processor includes: a processing tray on which sheets are accumulated; an alignment and discharge unit which performs alignment and discharge; a staple unit which staples a sheet bundle of the processing tray; and a detection sensor. In a case of staple continuous printing of continuously printing a plurality of copies by performing stapling to each copy, the printing control unit recognizes the time allowance from the discharge detection of the sheet bundle of a measurement object to the detection of arrival of the first sheet of the next copy of the measurement object by the detection sensor. The printing control unit determines the inter-correction part time based on the time allowance.SELECTED DRAWING: Figure 11

Description

  The present invention relates to an image forming apparatus that performs post-processing of staples.

  The image forming apparatus may include a post-processing device. The post-processing device performs post-processing on the printed paper. The aftertreatment device is sometimes referred to as a finisher. There are various types of post-processing. Patent Document 1 describes an example of an apparatus that punches a sheet and binds the hole with a ring member.

  Specifically, Patent Document 1 discloses that a perforation process is performed on a sheet or a bundle of sheets, a perforation process is performed using a ring member, ring binding is performed, and the final sheet of the preceding part and the leading sheet of the subsequent part are performed. A bookbinding apparatus is described in which the paper sections, which are the intervals between the two, are different in a first mode in which punching processing and binding processing are performed and in a second mode in which only punching processing is performed. With this configuration, an interval between paper sections is set in accordance with each mode, and an attempt is made to improve productivity when the two modes coexist (see Patent Document 1: Claim 1, paragraph [0008]).

JP 2009-262395 A

  In an image forming apparatus, there are cases where a printing speed according to specifications is determined. In such an image forming apparatus, paper feeding (paper feeding) is performed so as to satisfy the printing speed specified in the specification. For example, in the case of an image forming apparatus that prints 60 sheets per minute, sheet feeding is started once per second. In this way, the paper feed start interval may be determined based on the specification. As a result, printed paper is carried into the post-processing device at every predetermined paper feed start interval. In addition, one sheet reaches the processing tray in the post-processing apparatus at every sheet feeding start interval.

  When post-processing is performed, the sheets are sequentially stacked on the processing tray while being aligned. Alignment is a process for aligning the edges of each sheet. When one sheet of paper has accumulated on the processing tray, the set post-processing is performed. The post-processed sheet bundle is discharged. A sheet bundle is discharged between the copies. After the stack of paper is discharged, the next sheet of paper must reach the tray. For this reason, the paper feed start interval between copies is longer than the (normal) paper feed start interval other than between copies. For example, when post-processing is performed, the time required for discharging the bundle of sheets is added to the normal sheet feeding start interval. Therefore, when post-processing is performed, the productivity (printing speed) of the image forming apparatus decreases.

  Here, the post-processing apparatus may be equipped with a staple unit. When one sheet of paper is collected in the tray, the staple unit automatically binds the paper. The stapled sheet bundle is discharged. When a staple print job is continuously performed, stacking of one sheet of paper → staple → paper bundle discharge is repeated. It is also necessary to consider the time required for stapling. The time required for stapling is the time required from the start to the end of stapling. When stapling is performed, the paper feed start interval between copies is equal to or longer than the normal paper feed start interval plus the time required for stapling and the time required for paper bundle discharge.

  Here, there is a variation in time required for stapling for each staple unit. The time required for stapling varies depending on the thickness of the sheet bundle. The longer the number of sheets and the thicker the sheet, the longer the time from the start of stapling to the end of binding. Therefore, the manufacturer of the staple unit may determine the guaranteed time as a specification. The manufacturer guarantees that the staples can be finished within the warranty time at the longest. The guaranteed time can be said to be the maximum time required for stapling. For example, the guaranteed time corresponds to the time required for stapling when the thickness of the sheet bundle is the maximum thickness that can be stapled.

  Conventionally, a paper feed start interval between copies is determined based on a guaranteed time. That is, when stapling is performed, the sheet feeding start interval between copies is determined based on a time obtained by adding a normal sheet feeding start interval, a guaranteed time, a required time for bundle discharge, and the like. As a result, in any job, the first sheet of the next copy does not arrive before completion of sheet bundle discharge. However, when stapling is performed, there is a problem in that the productivity (printing speed) of the image forming apparatus tends to decrease.

  The technique described in Patent Document 1 does not mention a decrease in productivity when stapling is performed. The technology described in Patent Document 1 relates to perforation and ring binding. The post-processing that is the subject of Patent Document 1 is not post-processing in which the required time varies depending on the number of paper bundles and the type of paper, such as stapling.

  According to the present invention, the paper feed start interval between the copies at the time of stapling is made shorter than before, and the decrease in productivity (printing speed) of the image forming apparatus is suppressed.

  In order to solve the above problem, an image forming apparatus according to a first aspect includes a printing unit, a paper feeding unit, a printing control unit, and a post-processing device. The printing unit performs printing on paper. The paper feeding unit supplies paper to the printing unit. The printing control unit (engine control unit) controls the printing unit and the paper feeding unit. The post-processing device performs post-processing of the paper printed by the printing unit. The post-processing apparatus includes a paper transport unit, a processing tray, an alignment discharge unit, a staple unit, and a detection sensor. The paper transport unit transports the paper printed by the printing unit. The processing tray is loaded with sheets conveyed by the sheet conveying unit. The alignment discharge unit aligns the sheets sent to the processing tray, and discharges the sheets that have been post-processed. The staple unit staples the sheet bundle on the processing tray. The detection sensor detects the arrival of the sheet to the processing tray and the discharge of the sheet to the discharge tray. When performing continuous staple printing in which a plurality of copies are printed by stapling each portion, the print control unit, except for between copies, when a predetermined inter-sheet time has elapsed since the start of feeding the immediately preceding sheet Then, the paper feeding unit starts feeding the next paper. When the reference inter-unit time has elapsed from the start of feeding the last sheet of the predetermined measurement target portion among the portions to be printed by the staple continuous printing (between the measurement target portion and the next portion) ), The print control unit causes the sheet feeding unit to start feeding the first sheet next to the measurement target unit. The print control unit recognizes a margin time. The allowance time is the time from when the detection sensor detects the discharge of the sheet bundle of the measurement target section until the arrival of the first sheet of the next section of the measurement target section is detected. Further, the print control unit determines the correction unit time based on the margin time. When the time between the correction sections has elapsed since the start of feeding the last sheet of the section that is not the measurement target section, the print control section causes the sheet feeding section to start feeding the first sheet of the next section . The reference inter-unit time is longer than the inter-paper time. The time between correction parts is shorter than the time between reference parts, and is more than the time which subtracted the margin time from the time between reference parts.

  According to the present invention, the paper feed start interval between the copies during stapling can be made shorter than before. Thereby, a decrease in productivity (printing speed) of the image forming apparatus can be suppressed.

1 is a diagram illustrating an example of a multifunction machine according to an embodiment. 1 is a diagram illustrating an example of a multifunction machine according to an embodiment. It is a figure which shows an example of the paper feed part which concerns on embodiment. It is a figure which shows an example of the post-processing apparatus which concerns on embodiment. FIG. 5 is a diagram illustrating an example of a paper feed start interval and inter-unit time in the multifunction peripheral according to the embodiment. FIG. 5 is a diagram illustrating an example of a paper feed start interval and inter-unit time in the multifunction peripheral according to the embodiment. It is a figure which shows an example of the table for a part time setting which concerns on embodiment. It is a figure which shows an example of the process performed between parts with the multifunctional device which concerns on embodiment. It is a figure which shows an example of the process performed between parts with the multifunctional device which concerns on embodiment. It is a figure which shows an example of margin time. 6 is a flowchart illustrating an example of a flow of correction of the time between reference units in the multifunction peripheral according to the embodiment.

  The image forming apparatus according to the present invention will be described below with reference to FIGS. The image forming apparatus will be described using the multifunction peripheral 100 as an example. However, each element such as configuration and arrangement described in this embodiment does not limit the scope of the invention and is merely an illustrative example. In the following description, printing in which a plurality of copies are continuously printed and stapled on each portion is referred to as “staple continuous printing”.

(Outline of image forming apparatus)
First, the multifunction peripheral 100 according to the embodiment will be described with reference to FIGS. 1 and 2. 1 and 2 are diagrams illustrating an example of the multifunction peripheral 100 according to the embodiment.

  The multi-function device 100 includes a main control unit 1 and a storage unit 11. The main control unit 1 controls the operation of the entire apparatus and controls each unit of the multifunction peripheral 100. The main control unit 1 includes a CPU 12 and an image processing unit 13. The CPU 12 performs calculation and control related to control. The image processing unit 13 performs image processing necessary for the job on the image data. The storage unit 11 includes a storage device such as a ROM, a RAM, and an HDD. The storage unit 11 stores a control program and data.

  The main control unit 1 is communicably connected to the document conveying unit 2a and the image reading unit 2b. The document transport unit 2a transports the set document toward the reading position. The image reading unit 2b reads a document transported by the document transport unit 2a or a document set on a document table (contact glass, not shown). The image reading unit 2b generates document image data. The main control unit 1 controls the operations of the document conveying unit 2a and the image reading unit 2b.

  The main control unit 1 is connected to the operation panel 3 so as to be communicable. The operation panel 3 includes a display panel 31, a touch panel 32, and hard keys 33. The operation panel 3 accepts user operations. The main control unit 1 recognizes settings made on the operation panel 3. For example, when a predetermined operation is performed on the touch panel 32, the main control unit 1 causes the display panel 31 to display a setting screen related to the post-processing device 7. The setting screen includes a setting image. The setting image is a button or key. Based on the operation of the setting image, the operation panel 3 accepts settings such as the presence / absence of post-processing in the post-processing device 7 and the presence / absence of stapling.

  The multifunction device 100 includes an engine control unit 4, a paper feeding unit 5, and a printing unit 6. The paper supply unit 5 supplies paper. Details of the sheet feeding unit 5 will be described later. The printing unit 6 performs printing on a sheet. The printing unit 6 includes a conveyance unit 6a, an image forming unit 6b, and a fixing unit 6c. The engine control unit 4 (corresponding to a print control unit) is connected to the main control unit 1 so as to be communicable. The main control unit 1 gives the engine control unit 4 a print instruction, the contents of the print job, and image data used for printing. Based on an instruction from the main control unit 1, the engine control unit 4 controls operations of the paper feeding unit 5 and the printing unit 6. Specifically, the engine control unit 4 causes the paper supply unit 5 to supply paper to the printing unit 6. The engine control unit 4 conveys the supplied paper to the conveyance unit 6a. The engine control unit 4 causes the image forming unit 6b to form a toner image. The image forming unit 6b transfers the toner image to a sheet. The engine control unit 4 fixes the toner image transferred on the paper to the fixing unit 6c.

  The main control unit 1 includes a communication unit 14. The communication unit 14 is an interface for communicating with a computer 200 such as a PC or a server. The communication unit 14 receives data (print data) indicating print contents such as image data. The main control unit 1 causes the printing unit 6 to perform printing based on the printing data.

(Paper Feeder 5)
Next, an example of the paper feeding unit 5 according to the embodiment will be described with reference to FIGS. 2 and 3. FIG. 3 is a diagram illustrating an example of the sheet feeding unit 5 according to the embodiment.

  As illustrated in FIG. 2, the multifunction peripheral 100 includes a first paper feeding cassette 51, a second paper feeding cassette 52, and a registration roller pair 53 as the paper feeding unit 5. The first sheet cassette 51 and the second sheet cassette 52 contain sheets. A first paper feed roller 54 is provided in the first paper feed cassette 51. A second paper feed roller 55 is provided in the second paper feed cassette 52. As shown in FIG. 3, a first paper feed motor 56 is provided to rotate the first paper feed roller 54. A second paper feed motor 57 is provided to rotate the second paper feed roller 55.

  When printing is performed, the engine control unit 4 supplies paper to the first paper feed cassette 51 or the second paper feed cassette 52 (primary paper feed). When paper is fed from the first paper feed cassette 51, the engine control unit 4 rotates the first paper feed motor 56. The paper in the first paper feed cassette 51 is sent out by the first paper feed roller 54. When paper is fed from the second paper feed cassette 52, the engine control unit 4 rotates the second paper feed motor 57. The paper in the second paper feed cassette 52 is sent out by the second paper feed roller 55.

  The paper sent out from each paper feed cassette is transported by the transport unit 6a (transport roller pair 61). As a result, the paper reaches the registration roller pair 53. The registration roller pair 53 is provided between each paper feed roller and the image forming unit 6b (see FIG. 2). As shown in FIG. 3, a registration motor 58 is provided to rotate the registration roller pair 53. The registration roller pair 53 is rotated by the rotation of the registration motor 58.

  The transport roller pair 61 and the registration roller pair 53 may be rotated by the same motor. In this case, an electromagnetic clutch (not shown) is provided for the registration roller pair 53. When the registration roller pair 53 is rotated, the engine control unit 4 connects the electromagnetic clutch. Further, when the registration roller pair 53 is stopped, the engine control unit 4 opens the electromagnetic clutch.

  When the sheet reaches the registration roller pair 53, the engine control unit 4 stops the registration roller pair 53. The leading edge of the paper hits the nip of the registration roller pair 53. The engine control unit 4 continues the paper conveyance while abutting the leading edge of the paper against the registration roller pair 53. Due to the elasticity of the paper, the leading edge of the paper follows the nip of the registration roller pair 53. Thereby, the skew of the paper is corrected.

  After the skew correction, the engine control unit 4 rotates the registration roller pair 53. As a result, the paper is supplied to the image forming unit 6b (secondary paper feeding). The registration roller pair 53 functions as the paper feeding unit 5 that supplies paper used for printing to the printing unit 6 (image forming unit 6b). A registration sensor 59 is provided between the registration roller pair 53 and each paper feed roller. Based on the output of the registration sensor 59, the engine control unit 4 can recognize the arrival and passage of the sheet to the registration roller pair 53.

  In an image forming apparatus, a printing speed according to specifications may be determined. In the MFP 100, the number of sheets that can be printed per minute is determined. For example, when A4 paper is used, the number of printed sheets per unit time is 60 sheets per minute (60 page per minute = 60 ppm). Further, since there is a specification for printing 30 sheets per minute, ppm may be a value other than 60.

  The engine control unit 4 causes paper feeding so that printing is performed at a printing speed according to the specification. Specifically, the engine control unit 4 causes the registration roller pair 53 to start feeding once at a predetermined paper interval A1 (see FIGS. 5 and 6). The inter-paper time A1 is a time obtained by dividing the unit time by the number of printed sheets according to the specification. The inter-paper time A1 is determined in advance according to the paper size. When the A4 size is 60 ppm, the paper interval time A1 is 60 seconds / 60 sheets = 1 second.

  The engine control unit 4 stops the rotation of the registration roller pair 53 before the paper interval time A1 has elapsed from the start of rotation of the registration roller pair 53. The engine control unit 4 controls the printing speed by starting the rotation of the registration roller pair 53 at every sheet interval A1. The engine control unit 4 applies the first paper feed cassette 51 (first paper feed motor 56) and the second paper feed cassette 52 (second paper feed motor 57) in time for the secondary paper feed of the registration roller pair 53. Let the paper feed.

  The engine control unit 4 starts the rotation of the first paper feed roller 54 (first paper feed motor 56) and the second paper feed roller 55 (second paper feed motor 57) at every sheet interval time A1. The printing speed may be controlled. In this case, the first paper feeding cassette 51 and the second paper feeding cassette 52 function as the paper feeding unit 5 that supplies paper used for printing to the printing unit 6 (image forming unit 6b). Then, the engine control unit 4 starts the rotation of the registration roller pair 53 when a predetermined waiting time elapses after the output of the registration sensor 59 detects the arrival of the sheet.

(Post-processing device 7)
Next, the outline | summary of the post-processing apparatus 7 which concerns on embodiment is demonstrated using FIG. 2, FIG. FIG. 2 is a diagram illustrating an example of the multifunction peripheral 100 to which the post-processing device 7 according to the embodiment is attached. FIG. 4 is a diagram illustrating an example of the post-processing device 7 according to the embodiment.

  The post-processing device 7 performs post-processing of the paper printed by the printing unit 6. The post-processing device 7 is attached to the main body of the multifunction peripheral 100. As shown in FIG. 2, the post-processing device 7 is attached (fitted) to the in-body discharge unit 101 of the multifunction peripheral 100. There is also a type of image forming apparatus in which the post-processing device 7 is attached to the side surface of the apparatus.

  The printed paper that has passed through the fixing unit 6 c is sent to the post-processing device 7 from the carry-in port 102. As shown in FIG. 2, the post-processing device 7 includes a punch unit 71, a paper transport unit 72, a staple unit 8, an alignment discharge unit 90, and a detection sensor 7s. The post-processing device 7 includes a processing tray 9 and a discharge tray 73.

  As shown in FIG. 4, the post-processing device 7 includes a post-processing control unit 70. The post-processing control unit 70 is a substrate including a processing circuit 70a such as a CPU, a memory 70b, and a timing circuit 70c. The post-processing control unit 70 controls the operation of each unit. The post-processing control unit 70 may not be provided in the post-processing device 7 and the engine control unit 4 may control the operation of the post-processing device 7. When stapling is set on the operation panel 3, the post-processing control unit 70 causes the stapling unit 8 to perform stapling on the sheet bundle before ejection.

  When the operation panel 3 is set to perform punching processing, the post-processing control unit 70 causes the punching unit 71 to perform punching processing on paper. When the setting for punching processing is not performed on the operation panel 3, the post-processing control unit 70 does not cause the punching unit 71 to perform punching processing on paper.

  The paper transport unit 72 transports the paper (printed paper) that has been carried in from the carry-in entrance 102 and passed through the punch unit 71. The paper transport unit 72 transports the paper to the processing tray 9. A sheet is fed into the processing tray 9. As shown in FIG. 2, the paper transport unit 72 includes a first transport roller pair 74, a second transport roller pair 75, and a paper transport guide 76. As shown in FIG. 4, the paper transport unit 72 includes a transport motor 72m. When the paper is transported to the paper transport unit 72, the post-processing control unit 70 rotates the transport motor 72m. Thereby, the 1st conveyance roller pair 74 and the 2nd conveyance roller pair 75 rotate.

  The post-processing control unit 70 causes the alignment discharge unit 90 to align each sheet sent to the processing tray 9. Further, the post-processing control unit 70 causes the aligned discharge unit 90 to discharge the paper after the post-processing. As shown in FIG. 2, the alignment discharge unit 90 includes a first discharge roller 91, a second discharge roller 92, and a width regulating plate 93. The first discharge roller 91 and the second discharge roller 92 are provided on the downstream side in the transport direction of the processing tray 9. A second discharge roller 92 is provided at the end of the processing tray 9. The upper roller of the second discharge roller 92 is the first discharge roller 91. The first discharge roller 91 is supported by a roller holder 94. By the roller holder 94, the first discharge roller 91 can swing in the vertical direction. The alignment discharge unit 90 includes a vertical movement mechanism 95 that moves the first discharge roller 91 and the roller holder 94 up and down. The vertical movement mechanism 95 may include a drive source. A motor or a solenoid can be used as the drive source.

  As shown in FIG. 4, the alignment discharge unit 90 includes a discharge motor 9m. The discharge motor 9m is a motor that can rotate forward and backward. The first discharge roller 91 rotates in accordance with the discharge motor 9m. In the following description, the direction in which the paper is conveyed to the discharge tray 73 is referred to as the forward direction, and the direction in which the paper is conveyed in the direction opposite to the discharge tray 73 is referred to as the reverse direction.

  The width regulating plate 93 is provided on the upper surface side of the processing tray 9. The width regulating plate 93 is a pair of plates. The paper on the processing tray 9 is sandwiched in a direction perpendicular to the paper transport direction. The alignment discharge unit 90 includes a shift mechanism 96. The shift mechanism 96 moves the width regulating plate 93 in a direction perpendicular to the paper transport direction. Shift mechanism 96 includes a motor. The shift mechanism 96 includes mechanical elements such as a gear, a belt, and a shaft for moving the width regulating plate 93 in a direction perpendicular to the paper transport direction. The post-processing control unit 70 moves the width regulating plate 93 in the direction perpendicular to the paper transport direction by the shift mechanism 96. Thereby, the position of the edge part of each sheet on the processing tray 9 in the direction perpendicular to the sheet conveying direction can be aligned.

  A stopper 97 is provided at the upstream end of the processing tray 9 in the sheet conveyance direction. Further, a detection sensor 7s is provided on the downstream side of the processing tray 9 (upstream side of the discharge tray 73). The detection sensor 7s detects the arrival of the sheet to the processing tray 9 and the discharge of the sheet to the discharge tray 73.

  The staple unit 8 includes a staple drive source 81 and a staple mechanism 82. The staple driving source 81 is a solenoid or a motor. The stapling mechanism 82 includes a driver 83, a magazine 84, and a bending table 85. Staple needles are loaded into the magazine 84. The magazine 84 can be replenished with staples. The driver 83 is a metal plate that pushes down the staple needle. The bending table 85 is a table for bending the leading end of the staple needle that has penetrated the paper inward. A magazine 84 is provided above the bending table 85. A driver 83 is provided above the magazine 84. A gap is provided between the bending table 85 and the magazine 84. A sheet bundle is positioned in this gap.

  When stapling is performed, the post-processing control unit 70 operates the staple driving source 81. The driver 83 moves downward by the operation of the staple driving source 81. The driver 83 pushes down the leading needle in the magazine 84. As a result, the staple needle is driven into the paper. Further, the driver 83 pushes down the staple needle. The staples that have penetrated the paper are bent by the bending table 85. Paper binding is completed. At the same time, the position of the driver 83 is also restored.

  The operation panel 3 accepts the setting of the position for stapling. For example, the staple position can be set like the upper right corner of the sheet bundle and the middle of one side of the sheet. The post-processing control unit 70 causes the shift mechanism 96 to shift the position of the sheet bundle so that the staple is driven into the set position.

(1) When stapling When stapling, the post-processing control unit 70 first transports the paper in the direction of the discharge tray 73. The post-processing control unit 70 rotates the discharge motor 9m in the forward direction. The detection sensor 7s detects the arrival of the leading edge of the paper. The output of the detection sensor 7s is input to the post-processing control unit 70. The post-processing control unit 70 recognizes the arrival of the sheet at the installation position of the detection sensor 7s. When a predetermined time has elapsed since the detection of the leading edge of the sheet, the post-processing control unit 70 moves the roller holder 94 and the first discharge roller 91 downward.

  Specifically, the post-processing control unit 70 includes the sheet and the first discharge roller at the timing when the trailing edge of the sheet passes the sheet conveying unit 72 (second conveying roller pair 75) and the trailing edge of the sheet is placed on the processing tray 9. 91 is brought into contact. As a result, the first discharge roller 91 and the uppermost sheet on the processing tray 9 come into contact with each other. In this state, the post-processing control unit 70 rotates the discharge motor 9m in the reverse direction. As a result, the first discharge roller 91 rotates the paper in the opposite direction to the discharge tray 73 (reversely rotates). As a result, the upstream end of the uppermost sheet on the processing tray 9 abuts against the stopper 97. Thereby, the edge part of the conveyance direction of a paper can be aligned. Subsequently, the post-processing control unit 70 operates the shift mechanism 96 (width regulating plate 93). The alignment discharge unit 90 aligns the paper in a direction perpendicular to the paper conveyance direction.

  When one sheet of paper is not accumulated in the processing tray 9, the post-processing control unit 70 repeats the upward movement and the downward movement of the roller holder 94 and the first discharge roller 91. During retreating upward, the leading edge of the next sheet passes between the first discharge roller 91 and the second discharge roller 92. The detection sensor 7s detects the arrival of the leading edge of the next sheet. Then, the next sheet is stacked on the processing tray 9. The post-processing control unit 70 repeats paper alignment every time the paper reaches the processing tray 9.

  When one sheet bundle is collected on the processing tray 9, after the sheet alignment process, the post-processing control unit 70 causes the staple unit 8 to perform a staple process before discharging the sheet bundle. After stapling, the post-processing control unit 70 causes the shift mechanism 96 to shift the position of the sheet bundle. For example, the post-processing control unit 70 shifts the position of the sheet bundle in a direction perpendicular to the sheet conveyance direction for each unit. Thereby, the position of the sheet bundle discharged to the discharge tray 73 is shifted by one copy.

  When discharging the sheet bundle, the post-processing control unit 70 lowers the roller holder 94 and the first discharge roller 91. The first discharge roller 91 comes into contact with the paper. After shifting the sheet bundle, the post-processing control unit 70 rotates the discharge motor 9m forward. As a result, the first discharge roller 91 and the second discharge roller 92 rotate in the paper discharge direction (forward direction). As a result, the stapled sheet bundle is discharged to the discharge tray 73. Thereafter, in order to place the first sheet of the next section on the processing tray 9, the post-processing control section 70 retracts the roller holder 94 and the first discharge roller 91 upward.

(2) When discharging one unit without performing stapling When stapling is not performed, the stapling process is skipped. Specifically, the post-processing control unit 70 conveys the paper toward the discharge tray 73. The detection sensor 7s detects the arrival of the leading edge of the paper. The post-processing control unit 70 recognizes the arrival of the sheet at the installation position of the detection sensor 7s. Subsequently, the post-processing control unit 70 moves the roller holder 94 and the first discharge roller 91 downward.

  As a result, the first discharge roller 91 and the uppermost sheet on the processing tray 9 come into contact with each other. In this state, the post-processing control unit 70 rotates the discharge motor 9m in the reverse direction. The post-processing control unit 70 aligns the ends of the sheet bundle in the conveyance direction. Subsequently, the post-processing control unit 70 operates the shift mechanism 96 (width regulating plate 93) to align the sheets.

  When one sheet of paper is not accumulated in the processing tray 9, the post-processing control unit 70 repeats the upward movement and the downward movement of the roller holder 94 and the first discharge roller 91. Further, the post-processing control unit 70 repeats the alignment of the paper every time the paper reaches the processing tray 9.

  When one sheet bundle is collected on the processing tray 9, after the sheet alignment process, the post-processing control unit 70 causes the shift mechanism 96 to shift the position of the sheet bundle. After shifting the sheet bundle, the post-processing control unit 70 rotates the discharge motor 9m forward. As a result, the sheet bundle is discharged to the discharge tray 73. Thereafter, the post-processing control unit 70 retracts the roller holder 94 and the first discharge roller 91 upward.

(3) When discharging one sheet at a time without stapling The operation panel 3 can be set to discharge one sheet at a time to the discharge tray 73. In this case, the post-processing control unit 70 maintains the roller holder 94 and the first discharge roller 91 at the lower position. Further, the post-processing control unit 70 rotates the discharge motor 9m in the normal direction. Paper is not collected in the processing tray 9. The sheets are discharged to the discharge tray 73 one by one.

(Feed start interval)
Next, an example of a paper feed start interval in the multifunction peripheral 100 according to the embodiment will be described with reference to FIGS. 5 and 6 are diagrams illustrating an example of the paper feed start interval and the inter-unit time B1 in the multifunction peripheral 100 according to the embodiment.

  As described above, in the multi-function device 100, feeding is basically started at every sheet interval time A1. When the paper feed start interval is set to the paper interval time A1, the paper is carried into the post-processing device 7 every paper interval time A1. Further, based on the output of the detection sensor 7s, the post-processing control unit 70 recognizes the arrival of the sheet at every sheet interval A1. Further, sheets are stacked on the processing tray 9 at every sheet interval time A1. The alignment of the sheets is performed after the sheets are stacked on the processing tray 9 until the next sheet is stacked on the processing tray 9.

  Here, when stapling is performed by the post-processing device 7, processing for shifting a bundle of sheets for stapling, shifting for stapling, shifting a discharge position, and discharging a bundle is performed between copies. Even when stapling is not performed, a shift for shifting the discharge position and a bundle discharge process are performed between the copies. When printing a plurality of copies in succession, it is necessary to perform these processes between the copies. In other words, it is necessary to perform these processes after the last sheet of a set is stacked on the processing tray 9 and before the next set of sheets is stacked on the processing tray 9. In addition, it is necessary to perform these processes between the sections after the detection sensor 7s detects the arrival of the last sheet of the previous section and until the detection sensor 7s detects the arrival of the first sheet of the next section. is there. For this reason, between the copies, the paper feed start interval is extended beyond the paper interval time A1.

  FIG. 5 shows an example of the paper feed start interval when the post-processing device 7 performs post-processing. FIG. 6 shows an example of the paper feed start interval when the post-processing device 7 does not perform post-processing. 5 and 6 show an example in which three copies are printed continuously. 5 and 6, the number of pages included in one copy is three.

  When performing post-processing and printing a plurality of copies, as shown in FIG. 5, between the sets, the engine control unit 4 sets the paper feed interval to an inter-part time B <b> 1. In other words, the time from the start of feeding the last sheet of the previous section to the feeding of the first sheet of the next section is referred to as a section time B1. Due to the unique processing between the copies, the interval B1 is longer than the interval A1. For sheets other than the last of the sets, the engine control unit 4 sets the sheet feeding interval to the sheet interval time A1. The engine control unit 4 sets the paper feed interval from the first page of the copy to the last two pages of the copy as the paper interval time A1.

  When the sheet is discharged to the discharge tray 73 without post-processing (when discharged as it is), the sheet bundle shift for stapling, the stapling, the shift for shifting the discharge position, and the bundle discharging are performed between the sections. Not done. When the post-processing is not performed, as shown in FIG. 6, the engine control unit 4 determines the time from the start of feeding the last sheet of the previous unit to the feeding of the first sheet of the next unit as the inter-sheet time. Let A1.

(Part time B1)
Next, the inter-unit time B1 in the multifunction peripheral 100 according to the embodiment will be described with reference to FIGS. FIG. 7 is a diagram illustrating an example of the inter-unit time setting table D1 according to the embodiment. 8 and 9 are diagrams illustrating an example of processing performed between the units in the MFP 100 according to the embodiment.

  When performing post-processing and printing a plurality of copies, the engine control unit 4 determines the inter-part time B1 according to the content of the post-processing. In this description, a case where stapling is performed, and a case where a bundle is discharged without stapling will be described.

  The storage unit 11 stores an inter-part time setting table D1 for determining the inter-part time B1. FIG. 7 shows an example of the inter-unit time setting table D1. In this table, a process performed between copies is defined. For example, sheet alignment, shift of a bundle of sheets for stapling, stapling, shift for shifting the discharge position, and bundle discharge are defined.

  In the inter-unit time setting table D1, the required time for each defined process is defined. The required time T1 is a time required for alignment of the sheets stacked on the processing tray 9. The required time T2 is the time required to shift the sheet bundle in accordance with the stapling mechanism 82 (staple position). The required time T3 is a required time for stapling. The required time T4 is a time required for the shift for shifting the discharge position. The required time T5 is the time required for bundle discharge.

  There are individual differences in the staple unit 8. When the same sheet and the same number of sheets are stapled, the time required for stapling varies depending on the unit. In addition, even when the number of sheets is the same, the thicker the sheet, the longer the required time for stapling. Even if the thickness of each sheet is the same, the longer the number of sheets, the longer the required time for stapling. Therefore, the guaranteed time (maximum time) in the specifications of the staple unit 8 is adopted as the required time T3 of the inter-unit time setting table D1. The guaranteed time is a time guaranteed by the manufacturer of the staple unit 8. Even when the thickness of the sheet bundle is the maximum possible thickness, stapling is completed within the guaranteed time from the start of stapling.

  As shown in FIG. 8, when stapling is performed, sheet alignment, shifting of a bundle of sheets for stapling, stapling, shifting for shifting the discharge position, and discharging of the bundle are performed between the sections. Therefore, the engine control unit 4 sets a time obtained by adding the required times T1 to T5 as the inter-unit time B1. In the following description, when a plurality of copies are printed by stapling, the inter-unit time B1 determined by the engine control unit 4 based on the inter-unit time setting table D1 is referred to as “reference inter-unit time B2”. As shown in FIG. 8, the inter-part time B1 (reference inter-part time B2) when stapling is T1 + T2 + T3 + T4 + T5. The reference inter-unit time B2 may be a time obtained by adding a margin time to T1 + T2 + T3 + T4 + T5. Due to the post-processing (staple) -specific processing, the reference inter-unit time B2 is longer than the inter-paper time A1.

  FIG. 9 shows a case where discharging is performed in units of bundles without stapling. In this case, processing related to stapling is not performed. Sheet alignment, shift for shifting the discharge position, and bundle discharge are performed between the sections. Therefore, as shown in FIG. 9, the engine control unit 4 sets a time obtained by adding T1 + T4 + T5 to the inter-unit time B1. The inter-part time B1 may be a time obtained by adding a margin time to T1 + T4 + T5.

(Correction of reference section time B2)
Next, an example of the flow of correcting the inter-reference unit time B2 according to the embodiment will be described with reference to FIGS. FIG. 10 is a diagram illustrating an example of the margin time T0. FIG. 11 is a flowchart illustrating an example of a flow of correcting the inter-reference unit time B2 in the multifunction peripheral 100 according to the embodiment.

  As described above, when a plurality of copies are printed by performing post-processing, the engine control unit 4 determines the inter-part time B1. In the case of continuous staple printing, the engine control unit 4 determines the reference inter-part time B2 as the inter-part time B1. The staple continuous printing is printing in which a plurality of copies are continuously printed and stapled on each portion. A guaranteed time is employed as the staple time T3 for setting the inter-reference portion time B2. This prevents the first sheet of the next section from being stacked on the processing tray 9 before discharging the sheet bundle. However, the productivity (printing speed) of the multifunction peripheral 100 decreases as the inter-reference section time B2 is longer.

  The actual time required for stapling is often shorter than the guaranteed time. The actual staple time is not often guaranteed. Therefore, in many continuous staple printings, there is a margin from the completion of bundle discharge until the arrival of the first sheet of the next copy is detected.

  FIG. 10 shows an example in which the actual staple time is shorter than the guaranteed time. In this case, a margin time T0 is allowed until the first page of the next part is stacked on the processing tray 9. The multifunction device 100 increases the productivity of the multifunction device 100 by reducing or eliminating the margin time T0.

  Accordingly, an example of a flow of correction of the inter-reference portion time B2 in the case of continuous staple printing will be described with reference to FIG. The start in FIG. 11 is a point in time when feeding of each part of continuous staple printing is started. In the continuous staple printing, the flowchart of FIG. 11 is executed every time one sheet is fed.

  First, the engine control unit 4 checks whether or not the part that has started paper feeding is the second or subsequent part from among the parts that are printed by continuous staple printing (step # 1). In the case of the last two or more copies, continuous staple printing is completed at the next feeding portion or the portion where feeding has started. There is no part that feeds paper with the corrected inter-part time B1. Therefore, when the last two or more parts (Yes in step # 1), this flow ends (end). Next, the engine control unit 4 determines whether or not the part that has started feeding is the measurement target part (step # 2). The measurement target part is a part that measures the margin time T0.

  As a premise, one print job for printing a plurality of copies with staples corresponds to continuous staple printing. A case where a plurality of print jobs for printing one or a plurality of copies with staples is continuously performed corresponds to continuous staple printing.

  The engine control unit 4 determines that the first copy among a plurality of copies that are continuously printed by continuous staple printing is the measurement target portion. In other words, the measurement target part is the first part of a plurality of copies printed by staple continuous printing.

  When a plurality of print jobs are continuously executed, the paper feed cassette may be changed between print jobs. In other words, there are cases where the paper feed cassette used during continuous staple printing can be changed. In some cases, the thickness of the paper stored in each paper feed cassette is different. As a result, the margin time T0 may change. Therefore, the engine control unit 4 determines that the first part to be printed after changing the paper feed cassette is the measurement target part.

  In addition, when a plurality of print jobs are continuously executed, the number of copies of one copy may change between print jobs. In other words, the number of copies of one copy may change during continuous staple printing. When the number of copies in one copy changes, the thickness of the sheet bundle changes. For example, a print job of 25 copies per copy may be started after a print job of 5 copies per copy. In this case, the margin time T0 changes. Therefore, the engine control unit 4 determines that the first part to be printed after changing the number of sheets is the measurement target part.

  In the case where the continuous staple printing is a print in which a plurality of print jobs are continuously performed, the next print job is started during the continuous staple printing (the print job is switched). The engine control unit 4 determines whether or not the paper feed cassettes used in the immediately preceding print job and the newly started print job are the same and the number of sheets included in one copy is the same. When it is determined that both are the same, the engine control unit 4 does not treat the first part of the newly started print job as the measurement target part. When it is determined that either one is different, the engine control unit 4 treats the first part of the newly started print job as the measurement target part.

  When it is the measurement target part (Yes in step # 2), when the reference part time B2 has elapsed from the start of feeding the last sheet of the measurement target part, the engine control unit 4 starts the first part next to the measurement target part. The paper feed unit 5 (registration roller pair 53) starts feeding the paper (step # 3). Until all the pages of one copy are stacked on the processing tray 9 (other than between copies), the processing unique to the copy is not performed. Of the first copy, for the second to last pages, the engine control unit 4 causes the registration roller pair 53 to feed the next sheet when the sheet interval time A1 has elapsed from the start of feeding the immediately preceding sheet. Let's start.

  Then, based on the output of the detection sensor 7s, the post-processing control unit 70 measures the margin time T0 (step # 4). The timing circuit 70c of the post-processing control unit 70 may measure the margin time T0. Specifically, the post-processing control unit 70 measures the time from the detection of the discharge of the measurement target portion of the detection sensor 7s until the arrival of the first sheet of the next portion of the measurement target portion is detected (step # 4). The post-processing control unit 70 notifies the engine control unit 4 of the margin time T0. Based on this notification, the engine control unit 4 recognizes the margin time T0 (step # 5). The engine control unit 4 determines the correction unit time B1 based on the margin time T0 (step # 6).

  Here, the engine control unit 4 determines the correction unit time B1 based on a value obtained by subtracting the margin time T0 from the reference unit time B2. The engine control unit 4 makes the correction unit time B1 shorter than the reference unit time B2. The engine control unit 4 may determine a value obtained by subtracting the margin time T0 from the reference inter-unit time B2 as the correction inter-unit time B1. Further, the engine control unit 4 may determine a time obtained by adding a predetermined margin to a value obtained by subtracting the margin time T0 from the reference inter-unit time B2 as the inter-correction unit time B1. In this case, the correction reference time becomes larger than the value obtained by subtracting the margin time T0 from the reference part time B2.

  It may not be preferable that the inter-part time B1 becomes too short. Therefore, when the time obtained by subtracting the margin time T0 from the reference inter-unit time B2 is shorter than the predetermined minimum time, the print control unit may determine the minimum time as the correction unit time B1. For example, the required time T1, T2, T4, and T5 may be added to the shortest time required for stapling determined by the specifications of the staple unit 8.

  If the part that has started feeding is not the measurement target part, the engine control unit 4 feeds the paper at the correction part time B1 between the parts. That is, the engine control unit 4 starts feeding the first sheet of the next unit to the registration roller pair 53 when the correction unit time B1 has elapsed since the start of feeding the last sheet of the unit that is not the measurement target unit. (Step # 7). And this flow ends (end)

  Conventionally, the paper feed start interval between copies is determined based on the guaranteed time of the staple unit 8. The guarantee time is the longest time for estimating the time required for stapling. The actual time required for stapling is often shorter than the guaranteed time. Therefore, the image forming apparatus according to the embodiment includes the printing unit 6, the paper feeding unit 5, the print control unit, and the post-processing device 7. The printing unit 6 performs printing on a sheet. The paper supply unit 5 supplies paper to the printing unit 6. The print control unit (engine control unit 4) controls the printing unit 6 and the paper feeding unit 5. The post-processing device 7 performs post-processing of the paper printed by the printing unit 6. The post-processing device 7 includes a paper transport unit 72, a processing tray 9, an alignment discharge unit 90, a staple unit 8, and a detection sensor 7s. The paper transport unit 72 transports the paper printed by the printing unit 6. The processing tray 9 is loaded with sheets conveyed by the sheet conveying unit 72. The alignment discharge unit 90 aligns the sheets sent to the processing tray 9 and discharges the sheets that have been post-processed. The staple unit 8 staples the sheet bundle on the processing tray 9. The detection sensor 7s detects the arrival of the sheet to the processing tray 9 and the discharge of the sheet to the discharge tray 73. During staple continuous printing, in which a plurality of copies are continuously printed by stapling each portion, the print control unit, except for between copies, when a predetermined sheet interval time A1 has elapsed from the start of feeding the immediately preceding sheet Then, the paper feeding unit 5 starts feeding the next paper. Among the parts to be printed by continuous staple printing, when the reference inter-part time B2 has elapsed from the start of feeding of the last sheet of the predetermined measurement target part (between the measurement target part and the next part) ), The printing control unit causes the sheet feeding unit 5 to start feeding the first sheet next to the measurement target unit. The print control unit recognizes a margin time T0 from when the detection sensor 7s detects the discharge of the sheet bundle of the measurement target unit to the arrival of the first sheet of the next unit of the measurement target unit. Further, the print control unit determines the correction unit time B1 based on the margin time T0. When the inter-correction section time B1 has elapsed since the start of feeding the last sheet of a section that is not the measurement target section, the print control section causes the sheet feeding section 5 to start feeding the first sheet of the next section. The reference interval time B2 is longer than the interval time A1. The correction part time B1 is shorter than the reference part time B2, and is equal to or more than the time obtained by subtracting the margin time T0 from the reference part time B2.

  As a result, it is possible to measure the margin time T0 from the completion of discharging the sheet bundle of the previous section to the arrival of the first sheet of the next section. Based on the margin time T0, the paper feed start interval between the copies can be shortened. Therefore, the paper feed start interval between the copies at the time of stapling can be made shorter than before. A decrease in productivity (printing speed) of the image forming apparatus can be suppressed.

  The margin time T0 can be measured between the first and second copies. The paper feed interval between the second and third copies can be set as the correction inter-unit time B1. Therefore, strictly speaking, staple continuous printing is targeted for continuous printing involving three or more copies of staples.

  The measurement target part is the first part among the parts to be printed by staple continuous printing. Thereby, after the start of the job, it is possible to shorten the paper feed start interval between the respective copies after the second copy and the third copy. A decrease in productivity (printing speed) of the image forming apparatus can be suppressed.

  The image forming apparatus includes a plurality of paper feed cassettes (a first paper feed cassette 51 and a second paper feed cassette 52). When the sheet cassette is switched, the thickness of the sheet bundle may change. When the thickness of the sheet bundle changes, the required time for stapling may actually change. In other words, the margin time T0 may change before and after the paper feed cassette is switched. Therefore, when the paper cassette to be used is changed during the continuous staple printing, the measurement target portion is the first portion to be printed after the paper cassette is changed. Thereby, the correction | amendment part time B1 can be reset and margin time T0 can be measured again. Then, an appropriate inter-corrector time B1 can be reset.

  When the number of copies of one copy changes, the thickness of the sheet bundle may change. The required time for stapling may actually change as the thickness of the paper changes. In other words, the margin time T0 may change before and after the number change. Therefore, when the number of sheets included in the copy changes during the continuous staple printing, the measurement target portion is the first portion to be printed after changing the number of copies. Thereby, the correction | amendment part time B1 can be reset and margin time T0 can be measured again. Then, an appropriate inter-corrector time B1 can be reset.

  In addition, when the continuous staple printing is a print in which a plurality of print jobs are continuously performed, the print control unit uses the same paper feed cassette for the print job that has newly started paper feed and the previous print job. And it is determined whether or not the number of sheets included in one copy is the same. When both are determined to be the same, the print control unit does not treat the first part of the print job that has newly started feeding as the measurement target part. In this case, in the print job in which paper feeding is newly started, the engine control unit 4 performs the next processing when the inter-correction unit time B1 used in the immediately preceding print job has elapsed from the start of feeding of the last paper of each unit. First, the paper feeding unit 5 starts feeding the first paper. When it is determined that either one is different, the print control unit treats the first part of the print job that has newly started feeding as the measurement target part. In this case, the margin time T0 and the correction unit time B1 are set. As a result, when the contents of the print job (the number of sheets fed and one copy) are the same, it is possible to skip the measurement of the margin time T0 in the subsequent print job. Accordingly, it is possible to suppress a decrease in productivity of the image forming apparatus as compared with the case where the margin time T0 is measured for each print job.

    When the distance between the last sheet of the previous part and the first sheet of the next part is too narrow, there is a case where sheet collision or jamming is likely to occur. Therefore, when the time obtained by subtracting the margin time T0 from the reference inter-unit time B2 is shorter than a predetermined minimum time, the print control unit determines the minimum time as the correction unit time B1. Thereby, it is possible to ensure a minimum required space.

  The scope of the present invention is not limited to the description of the embodiments, and various modifications can be made without departing from the spirit of the invention.

  The present invention can be used for an image forming apparatus including a post-processing apparatus.

100 MFP (image forming apparatus) 4 Engine control unit (printing control unit)
5 Paper Feed Unit 51 First Paper Feed Cassette (Paper Feed Cassette)
52 Second paper cassette (paper cassette)
53 Registration roller pair 6 Printing unit 7 Post-processing device 72 Paper transport unit 7s Detection sensor 8 Staple unit 9 Processing tray 90 Alignment discharge unit A1 Paper interval time B2 Reference interval time T0 Margin time

Claims (6)

A printing section for printing on paper;
A paper feeding unit for feeding paper to the printing unit;
A printing control unit for controlling the printing unit and the paper feeding unit;
A post-processing device that performs post-processing of the paper printed by the printing unit,
The post-processing device includes:
A paper transport unit for transporting the paper printed by the printing unit;
A processing tray on which sheets conveyed by the sheet conveying unit are stacked;
An alignment discharge unit that aligns the sheets sent to the processing tray and discharges the sheets after the post-processing;
A staple unit for stapling a bundle of sheets on the processing tray;
A detection sensor for detecting the arrival of the paper to the processing tray and the discharge of the paper to the discharge tray,
When using staple continuous printing that staples each copy and prints multiple copies continuously,
The print control unit
Except for between copies, when a predetermined inter-sheet time has elapsed from the start of feeding the immediately preceding sheet, the sheet feeding unit starts feeding the next sheet,
Among the parts to be printed by the continuous staple printing, when the time between the reference parts has elapsed since the start of feeding the last sheet of the predetermined measurement target part, the first paper supply of the next part of the measurement target part is performed. Start the paper in the paper feeder,
Recognizing the margin time from when the detection sensor detects the discharge of the sheet bundle of the measurement target portion to the arrival of the first paper of the next portion of the measurement target portion,
Based on the margin time, determine the time between correction parts,
When the time between the correction sections has elapsed since the start of feeding the last sheet of the section that is not the measurement target section, the feeding section starts the feeding of the first sheet of the next section,
The time between the reference parts is longer than the time between the papers,
The correction unit time is shorter than the reference unit time and is equal to or longer than a time obtained by subtracting the margin time from the reference unit time.   The image forming apparatus according to claim 1, wherein the measurement target unit is a first unit among units to be printed by the staple continuous printing. Including multiple paper cassettes,
When the paper feed cassette used during the staple continuous printing is changed,
The image forming apparatus according to claim 1, wherein the measurement target portion is a first portion printed after the paper feed cassette is changed.   4. The method according to claim 1, wherein when the number of sheets included in the copy changes during the continuous staple printing, the measurement target portion is a first portion printed after the change in the number of copies. The image forming apparatus described. Including multiple paper cassettes,
When the staple continuous printing is printing in which a plurality of print jobs are continuously performed,
The print control unit determines whether or not the paper feed cassette to be used is the same and the number of sheets included in one copy is the same in a print job in which paper feeding is newly started and the immediately preceding print job. And
When both are judged to be the same,
The print control unit does not treat the first part of a print job newly started feeding as the measurement target part,
When it is determined that either one is different,
5. The image forming apparatus according to claim 1, wherein the print control unit treats a first part of a print job newly started to be fed as the measurement target part. 6. When the time obtained by subtracting the margin time from the reference part time is shorter than a predetermined minimum time,
The image forming apparatus according to claim 1, wherein the print control unit determines the minimum time as the inter-correction unit time.

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