JP6116161B2 - Image forming apparatus and control method thereof - Google Patents

Description

  The present invention relates to an image forming apparatus including a relay conveyance device having a curl correction mechanism and a control method thereof.

  Generally, when a sheet (sheet) is conveyed from the image forming apparatus main body to the post-processing apparatus, a relay conveying apparatus is used. Some of these relay conveyance devices are provided with a curl correction mechanism for correcting the curl of the paper generated in the image forming process.

  The curl correction mechanism provided in the relay conveyance device includes an elastic roller and a metal roller, and performs curl correction by passing the sheet in a state where the elastic roller and the metal roller are in contact with each other (see Patent Document 1). ).

  In such a curl correction mechanism, the elastic roller and the metal roller are selectively brought into contact with and separated from each other, and when the elastic roller and the metal roller are in contact with each other, the relay is used to secure the pressure during the curl correction. The cover of the transport device cannot be opened.

JP 2002-265122 A

  By the way, if the pressing mechanism in the curl correcting mechanism breaks down and the roller pair remains in contact, the cover of the relay conveyance device cannot be opened. Causes of the failure include failure of the motor and sensor for separating, and disconnection of the bundle of sensors and motor. When such a failure of the pressing mechanism of the curl correction mechanism is detected, the use of the image forming apparatus is prohibited as an error state. The reason is as follows.

  Image formation is permitted while the curl correction mechanism's pressing mechanism has failed, and even if a paper jam occurs in the relay transport device, the user cannot remove the jammed paper in the relay transport device. is there.

  As a result, the user cannot use the image forming apparatus even though the image forming apparatus itself has not failed, and the convenience of the user is impaired.

  Accordingly, an object of the present invention is to provide an image forming apparatus that does not impair user convenience even if a failure occurs in a pressing mechanism of a curl correction mechanism, and a control method therefor.

In order to achieve the above object, an image forming apparatus according to the present invention detects a jam of a sheet in an image forming unit that forms an image on a sheet and a conveyance path in which a sheet on which an image is formed by the image forming unit is conveyed. A jam detection unit; a cover that is opened and closed to remove a sheet when a jam occurs in the conveyance path; and a first correction roller and a second correction roller that are arranged in the conveyance path and that are A pressing unit configured to be in a first pressing state in contact with pressure or in a second pressing state in contact with a second pressing force that is greater than the first pressing force, the first correction roller and the first Curl correcting means for correcting curl generated on the sheet by setting the second correction roller to the second pressing state, and the first correction roller and the second correction roller in the second pressing state. And locking means for the cover is locked in a closed state to a point, the first correction roller and the second correction roller releases the lock when in the first pressing state, the locking by the locking means An abnormality detecting means for detecting an abnormality that is not released, and when an abnormality that the lock is not released is detected by the abnormality detecting means, if a jam is not detected by the jam detecting means, the sheet is conveyed along the conveying path. Control means for permitting execution of image formation.

The control method according to the present invention includes a cover that is opened and closed to remove a sheet when a sheet jam occurs in a conveyance path in which an image-formed sheet is conveyed, and is disposed in the conveyance path. Press in a first pressing state in which the correction roller and the second correction roller are in contact with each other with a first pressing force or in a second pressing state in which the correction roller and the second correction roller are in contact with each other with a second pressing force larger than the first pressing force A curl correcting unit that corrects curl generated on the sheet by bringing the first correction roller and the second correction roller into the second pressing state, the first correction roller, and the first correction roller. When the second correction roller is in the second pressing state, the cover is locked in the closed state, and when the first correction roller and the second correction roller are in the first pressing state, the cover is locked. Unlock A control method of an image forming apparatus having a locking means for the storage step of storing an abnormality detecting step of detecting an abnormality locking by the locking means is not released, that the abnormality is detected by said abnormality detecting step in storage means And a permission step for permitting execution of image formation in which the sheet is conveyed along the conveyance path if a jam is detected in the storage means even if the storage unit stores that an abnormality is detected, and the sheet If the fact that an abnormality is detected is not stored in the storage means, the occurrence of a jam is informed, and the fact that an abnormality is detected is stored in the storage means. A notification step of notifying the failure of the locking means.

  ADVANTAGE OF THE INVENTION According to this invention, even if a failure arises in the press mechanism of a curl correction mechanism, it can reduce that a user's convenience is impaired.

1 is a diagram illustrating an example of an image forming apparatus that includes a relay conveyance device according to an embodiment of the present invention. FIG. 2 is a block diagram illustrating an example of a control unit used in the printer illustrated in FIG. 1. It is a figure for demonstrating the structure of the relay conveyance apparatus shown in FIG. 1, (a) is sectional drawing which shows the structure of a relay conveyance apparatus roughly, (b) is the broken-line arrow which shows a relay conveyance apparatus in (a). It is the figure seen from the direction. It is a perspective view for demonstrating the structure of the sheet curl correction mechanism shown to Fig.3 (a). It is a figure for demonstrating the lock | rock in the press mechanism used with the sheet | seat curl correction mechanism shown in FIG. 4, (a) is a figure which shows separation | spacing of a metal roller, (b) is a figure which shows the lock | rock of a metal roller. FIG. 2 is a timing chart for explaining detection of a paper conveyance jam that occurs in the relay conveyance device shown in FIG. 1, (a) is a timing chart for explaining stagnant jam, and (b) is for explaining delay jam. It is a timing chart. It is a flowchart for demonstrating an example of failure determination of the press mechanism of the relay conveyance apparatus shown in FIG. It is a flowchart for demonstrating the other example of failure determination of the press mechanism of the relay conveyance apparatus shown in FIG. 3 is a flowchart for explaining error determination when a paper jam occurs in the relay conveyance device shown in FIG. 1. 10A and 10B are diagrams for explaining a notification displayed on the operation unit in the error determination described with reference to FIG. 9, in which FIG. 10A is a diagram illustrating a paper jam processing notification, and FIG.

  Hereinafter, an example of an image forming apparatus including a relay conveyance device according to an embodiment of the present invention will be described with reference to the drawings.

  FIG. 1 is a cutaway view showing an example of an image forming apparatus including a relay conveyance device according to an embodiment of the present invention.

  In the following description, a full color laser printer system (hereinafter simply referred to as a printer) which is one of image forming apparatuses will be described as an example. Although a printer system will be described as an example of the image forming apparatus, the present invention can be similarly applied to an image forming apparatus such as a copying machine.

  The illustrated printer has a printer main body 1 and a sheet post-processing device (post-stage device) 1C, and a sheet (paper) that has been printed (image processing) by the printer main body 1C is sent to the sheet post-processing device 1C. The sheet post-processing apparatus 1C performs post-processing such as stapling on the paper.

  A relay conveyance device 3 to be described later is arranged in the printer main body 1, and the printed paper is sent to the sheet post-processing device 1C by the relay conveyance device 3. Further, a paper discharge device 1 </ b> A is provided in the printer main body 1, and an image reading device 1 </ b> B for reading an image on a document is disposed on the upper surface of the printer main body 1.

  The printer main body 1 is provided with an image forming unit 4. The image forming unit 4 includes detachable process cartridges 5a to 5d that store toners of respective colors (for example, cyan, magenta, yellow, and black). The process cartridges 5a to 5d are provided with electrophotographic photosensitive drums 6a to 6d, which are image carriers.

  An intermediate transfer member 4 is disposed facing the process cartridges 5a to 5d. Above the intermediate transfer member 4, a fixing device 15, a discharge unit 16, and a paper discharge device 1A are arranged. The fixing device 15 is for fixing the color toner image transferred to the sheet S as will be described later, and the discharge unit 16 is for discharging the sheet S to the discharge tray 17. The paper discharge device 1 </ b> A is for sending the sheet S to the relay conveyance device 3.

  On the other hand, a laser scanner 9 is disposed below the process cartridges 5a to 5d, and a sheet supply cassette 10 and a feeding device for conveying the sheet S are disposed below the laser scanner 9.

  When the sheet supply roller 11 rotates counterclockwise in the figure, the sheets S on the sheet supply cassette 10 are separated one by one by the sheet separation unit 12 that is in contact with the sheet supply roller 11. Then, the sheet S is fed to the registration roller pair 14 via the conveyance roller pair 13a and 13b.

The leading edge of the sheet S abuts against the registration roller pair 14 that has stopped rotating, and the conveyance of the sheet S is temporarily stopped, causing the sheet S to bend. As a result, the skew of the leading edge of the sheet S is corrected. Thereafter, at the timing when the rotation of the intermediate transfer belt 4a (described later) and the image writing position are synchronized, the sheet S is subjected to secondary transfer defined by the drive roller 4b and the secondary transfer roller 4c ( described later) by the rotation of the registration roller pair 14. It is conveyed to the part .

The process cartridges 5a to 5d are sequentially driven in accordance with the printing timing, and the photosensitive drums 6a to 6d are rotated in the clockwise direction in the drawing according to the driving. When a polygon mirror (not shown) provided in the laser scanner 9 starts to rotate, the charging devices 7a to 7d uniformly charge the surfaces of the photosensitive drums 6a to 6d.

  The laser scanner 9 exposes the surfaces of the photosensitive drums 6a to 6d in accordance with image signals, and forms electrostatic latent images on the photosensitive drums 6a to 6d. The developing rollers 8a to 8d of the developing device transfer the toner to the low potential portion of the electrostatic latent image and form toner images of the respective colors on the surfaces of the photosensitive drums 6a to 6d.

  The intermediate transfer body 4 includes an intermediate transfer belt 4a, and the intermediate transfer belt 4a is stretched around a driving roller 4b, an idler roller 4d, and a tension roller 4e. Then, the intermediate transfer belt 4a is driven in the counterclockwise direction in the figure by the driving roller 4b.

  Primary transfer rollers 4f to 4i are disposed opposite the photosensitive drums 6a to 6d with the intermediate transfer belt 4a interposed therebetween, and the primary transfer rollers 4f to 4i are counterclockwise due to friction with the intermediate transfer belt 4a. Rotate. When a voltage is applied to the primary transfer rollers 4f to 4i, the toner images on the photosensitive drums 6a to 6d are sequentially transferred to the intermediate transfer belt 4a by an electric field formed between the photosensitive drums 6a to 6d and the primary transfer rollers 4f to 4i. As a result, a color toner image is formed on the intermediate transfer belt 4a.

  When the color toner image formed on the intermediate transfer belt 4a reaches the secondary transfer roller 4c, the color toner image is drawn toward the secondary transfer roller 4c by an electric field generated by a voltage applied to the secondary transfer roller 4c. As a result, the color toner image on the intermediate transfer belt 4a is transferred to the sheet S.

Sheet S on which the color toner image has been transferred is conveyed to the fixing unit 15 is thus separated into the driving roller 4 b. While the sheet S is conveyed by a pair of fixing rollers (not shown) provided in the fixing device 15, heat and pressure are applied. As a result, the color toner image is fixed on the surface of the sheet S.

  Thereafter, the sheet S is discharged by a discharge roller pair 16 to a discharge tray 17 provided in the printer main body 1.

  When post-processing such as stapling or saddle folding is performed on the printed sheet S, the sheet S is sent from the printer main body 1 to the sheet post-processing apparatus 1C by the relay conveyance device 3 as described above.

When printing and post-processing are performed online, the sheet post-processing apparatus 1C is arranged in parallel with the printer main body 1 as illustrated. The relay conveyance device 3 that connects the discharge roller pair 18 of the printer main body 1 and the carry-in roller pair 20 provided in the sheet post-processing apparatus 1C is mounted substantially horizontally on the discharge tray 17 of the printer main body 1.

  FIG. 2 is a block diagram illustrating an example of a control unit used in the printer illustrated in FIG.

  The control unit 300 includes a CPU 301, a ROM 302, and a RAM 303. The ROM 302 stores a control program that operates on the CPU 301. The RAM 303 stores various data, and the RAM 303 is used as a work area for the CPU 301.

  When a print operation start instruction is input from the operation unit 330, the CPU 301 drives and controls the curl correction control motor 200 connected via an I / O (input / output interface) 310. The curl correction control motor 200 is a motor for performing contact and separation for curl correction described later.

  A curl correction control HP (home position) sensor 40, a buffer inlet sensor 50, and a buffer outlet sensor 51 are connected to the I / O 310, and the CPU 301 receives the curl correction control HP sensor 40 and the buffer inlet via the I / O 310. The detection output is taken from the sensor 50 and the buffer outlet sensor 51.

  The CPU 301 displays a message to be notified to the user on a display (not shown) provided in the operation unit 330. Further, the CPU 301 drives and controls the discharge roller 18 for conveying the sheet S and the second discharge motor 201 which is a drive source of the conveyance rollers 24a to 24c.

  The CPU 301 is connected to the image forming unit 320. The image forming unit 320 is, for example, the image forming unit 2 and the laser scanner 9 shown in FIG. 1, and the CPU 301 controls the image forming unit 320 to execute image formation, that is, printing.

  FIG. 3 is a diagram for explaining the configuration of the relay conveyance device 3 shown in FIG. FIG. 3A is a cross-sectional view schematically showing the configuration of the relay transfer device 3, and FIG. 3B is a view of the relay transfer device 3 seen from the direction of the broken line arrow 401 shown in FIG. FIG.

  The relay conveyance device 3 includes a first conveyance guide (first conveyance cover) 20 located on the upper side and a second conveyance guide (second conveyance cover) 21 located on the lower side. A relay conveyance path for conveying the sheet is defined by the first conveyance guide 20 and the second conveyance guide 21.

  Furthermore, the relay conveyance device 3 is provided with conveyance rollers 24a to 24c for conveying the sheet S to the sheet post-processing device 1C and a sheet curl correction mechanism 3a for correcting the curl of the sheet S.

The relay conveyance device 3 has a locking mechanism (locking means) that locks the first and second conveyance guides 20 and 21 while keeping them separated by a predetermined distance. Then, as described later, the opening / closing operation of the second transport guide 21 is performed by the locking mechanism.

  As illustrated, a buffer inlet sensor 50 is disposed on the inlet side of the sheet S in the first conveyance guide 20, and a buffer outlet sensor 51 is disposed on the outlet side of the sheet S. Then, a paper jam in the relay conveyance device 3 is detected by the buffer inlet sensor 50 and the buffer outlet sensor 51 (jam detection).

  FIG. 3B is a diagram of the relay conveyance device 3 viewed from the direction of the broken line arrow 401 at the position of the broken line 402 shown in FIG. 3A, and the locking mechanism is disposed at the position of the broken line 402. . The locking mechanism has a locking claw 25, and the locking claw 25 is attached to the second transport guide 21 so as to be rotatable about a rotation shaft 27 extending from the front side to the back side of the paper surface.

  When the operator pulls the handle 29 in the direction of the solid line arrow, the rotary shaft 27 rotates in accordance with the operation of the handle 29 and the locking claw 25 rotates in the clockwise direction. When the locking claw 25 moves to the position indicated by the broken line, the locking between the locking claw 25 and the shaft-shaped body 26 is released, and the second conveyance guide 21 can be opened downward (ie, Can be opened and closed).

  FIG. 4 is a perspective view for explaining the configuration of the sheet curl correction mechanism 3a shown in FIG.

  The sheet curl correction mechanism 3 a includes an elastic roller (first correction roller) 22 and a metal roller (second correction roller) 23. The elastic roller 22 is rotationally driven by a drive motor (not shown), and the metal roller 23 is pressed against the elastic roller 22. If the metal roller 22 and the elastic roller 23 are left in contact with each other for a long time, the surface of the elastic roller 23 may be deformed and it may be difficult to return to the original state. The pressure contact force with the roller 23 is weak (the contact state with almost no curl correction capability and the sheet is conveyed). This state is referred to as a separated state in this embodiment. For example, when the print job is finished, the metal roller 22 and the elastic roller 23 are in a separated state. Again, the metal roller 22 and the elastic roller 23 are not actually separated from each other.

  The sheet curl correction mechanism 3a has a slide plate 30 for selectively abutting and separating the elastic roller 22 and the metal roller 23. As shown in the figure, an opening groove 33 is provided in the slide plate 30, and the housing 31 is fitted in the opening groove 33.

  The elastic roller 22 is rotatably supported by the first conveyance guide 20 (not shown in FIG. 4). Further, both ends of the metal roller 23 are supported by the housing 31, and the metal roller 23 is held in a fixed state with respect to the first conveyance guide 20. The metal roller 23 is attached to the second conveyance guide 21 (not shown in FIG. 4) so that its axial center position moves within a movable range by the support spring 38.

  FIG. 5 is a view for explaining locking in the pressing mechanism used in the sheet curl correction mechanism shown in FIG. FIG. 5A is a view showing the separation of the metal rollers, and FIG. 5B is a view showing the lock of the metal rollers.

  Referring also to FIG. 5, a slit groove 37 for maintaining the alignment of the metal roller 23 is formed in the first transport guide 20. When the second conveyance guide 21 is closed, the shaft end of the metal roller 23 is guided to the slit groove 37 and the metal roller 23 comes into contact with the elastic roller 22.

As shown in FIG. 5A, when the slide plate 30 is positioned on the left side in the drawing, the position of the metal roller 23 is held only by the first pressing force by a spring (not shown). As a result, the metal roller 23 can escape from the elastic roller 22 in the separating direction that separates when the sheet S passes (first pressing state).

On the other hand, as shown in FIG. 5B, when the slide plate 30 moves to the right side in the figure, the position of the metal roller 23 is moved by the urging portion 42 of the slide plate 30 contacting the lower side of the metal roller 23. It will be fixed. As a result, the metal roller 23 cannot escape in the separating direction away from the elastic roller 22, and the distance between the axes of the metal roller 23 and the elastic roller 22 is fixed, and the second greater than the first pressing force. Can be maintained (second pressing state).

  When the fixed sheet S is passed through the nip portion between the elastic roller 22 and the metal roller 23, tension is applied to the sheet S by the pressing force of the metal roller 23 against the elastic roller 22. Then, the sheet S is curved along the curvature of the metal roller 23 to correct the curl of the sheet S.

  Here, the pressing mechanism used in the sheet curl correction mechanism 3a will be described.

  In FIG. 4, a cam opening groove 34 is formed in the slide plate 30, and a rotating shaft 36 is inserted into (inserted into) the cam opening groove 34. Cams 35 are provided at both ends of the rotation shaft 36, respectively. The rotary shaft 36 is rotationally driven by a curl correction control motor 200 (FIG. 2).

  Note that the cam 35 and the rotation shaft 36 are disposed in a state where the shaft center position is fixed so as to be rotatable with respect to the first conveyance guide 20. Further, the cam 35 is rotated by the driving force from the curl correction control motor 200, whereby the slide plate 30 reciprocates in the horizontal direction (the direction indicated by the solid line arrow).

  The CPU 301 (FIG. 2) performs pulse control of the curl correction control motor 200, whereby the cam 35 is controlled to move at a predetermined angle according to the pulse count of the curl correction control motor 200.

  A curl correction HP detection flag 41 is attached to the rotation shaft 36. The home position (HP) of the slide plate 30 is detected by the curl correction control HP sensor 40 and the curl correction HP detection flag 41. FIG. 5A shows a state in which the slide plate 30 is at the home position. Further, the error detection of the pressing mechanism is performed by the curl correction control HP sensor 40 and the curl correction HP detection flag 41 as described later.

  Next, the locking of the pressing mechanism used in the sheet curl correction mechanism 3a will be described.

  Referring to FIG. 5 again, a locking claw-shaped portion 30c is formed on the slide plate 30 at a predetermined interval below the urging portion 42. When the cam 35 rotates by driving the curl correction control motor 200, the slide plate 30 moves in the horizontal direction.

  By the movement of the slide plate 30, the locking claw-shaped portion 30 c enters the inverted L-shaped lock portion 21 a formed in the second conveyance guide 21. As a result, the operation of opening the second conveyance guide 21 by locking the second conveyance guide 21 is restricted. That is, the second transport cover is locked in the closed state.

  FIG. 6 is a timing chart for explaining detection of a paper conveyance jam that occurs in the relay conveyance device 3 shown in FIG. FIG. 6A is a timing chart for explaining the retention of paper (stay jam), and FIG. 6B is a timing chart for explaining the delay jam.

  Referring to FIG. 6A, when the trailing edge of the sheet S is detected by the buffer inlet sensor 50 during the conveyance of the sheet S in the relay conveying device 3, that is, the trailing edge of the sheet S passes the buffer inlet sensor 50. Then, the output of the buffer inlet sensor 50 changes from ON (H level) to OFF (L level).

  When the output of the buffer inlet sensor 50 changes from the H level to the L level, the CPU 301 determines the trailing edge of the sheet S according to the preset distance between the buffer inlet sensor 50 and the buffer outlet sensor 51 and the conveyance speed of the sheet S. Is determined to pass through the rear end time t1 until the buffer passes through the buffer outlet sensor 51.

  In other words, if the conveyance of the sheet S by the relay conveyance device 3 is normal, the output of the buffer outlet sensor 51 is output when the trailing edge passage time t1 elapses after the output of the buffer inlet sensor 50 changes from the H level to the L level. It will change from ON to OFF.

  At this time, the conveyance efficiency may decrease due to the durability of the conveyance roller and the configuration of the relay conveyance mechanism itself. For this reason, the delay in the transport time considering the decrease in transport efficiency is defined as the transport margin m1. The CPU 301 sets (t1 + m1) as the time required for the trailing edge of the sheet S to pass the buffer outlet sensor 51 after passing through the buffer inlet sensor 50 (transport time).

  If the output of the buffer outlet sensor 51 does not change from ON to OFF after the transfer time (t1 + m1) has elapsed after the output of the buffer inlet sensor 50 changes from the H level to the L level, the CPU 301 determines that the relay transfer device 3 It is determined that stagnant jam has occurred.

  6B, when the leading edge of the sheet S is detected by the buffer inlet sensor 50 during conveyance of the sheet S, that is, when the leading edge of the sheet S passes the buffer inlet sensor 50, the buffer inlet sensor 50 The output changes from OFF to ON.

  When the output of the buffer inlet sensor 50 changes from OFF to ON, the CPU 301 causes the leading edge of the sheet S to pass through the buffer outlet sensor 51 according to the distance between the buffer inlet sensor 50 and the buffer outlet sensor 51 and the conveyance speed of the sheet S. Until the tip passage time t2 is obtained.

  In other words, if the conveyance of the sheet S by the relay conveyance device 3 is normal, the output of the buffer outlet sensor 51 is switched from OFF to ON when the leading edge passage time t2 elapses after the output of the buffer inlet sensor 50 changes from OFF to ON. Will change.

  At this time, as described above, since the conveyance efficiency may be lowered due to the durability of the conveyance roller and the configuration of the relay conveyance mechanism itself, the conveyance time delay considering the decrease in the conveyance efficiency is defined as the conveyance margin m2. . Then, the CPU 301 sets (t2 + m2) as the conveyance time required for the leading edge of the sheet S to pass through the buffer outlet sensor 50 until it passes through the buffer outlet sensor 51.

  If the output of the buffer outlet sensor 51 does not change from OFF to ON after the transfer time (t2 + m2) has elapsed after the output of the buffer inlet sensor 50 changes from OFF to ON, the CPU 301 causes a delay jam in the relay transfer device 3. Is determined to have occurred.

  Note that the detection of the paper jam described in FIG. 6 is an example, and the present invention is not limited to this detection method.

  In the case of the stay jam described above, the sheet S remains in the relay conveyance device 3, and if the above-described pressing mechanism is broken, the sheet remains locked, and the user can The staying sheet cannot be removed.

  FIG. 7 is a flowchart for explaining an example of failure determination of the pressing mechanism of the relay conveyance device shown in FIG. The process of this flowchart is executed by the CPU 301.

  When a print start operation is performed, the CPU 301 causes the image forming unit 320 to feed the sheet S (S1101). Then, the CPU 301 drives the curl correction control motor 200 to bring the elastic roller 22 and the metal roller 23 into contact (S1102).

Subsequently, the CPU 301 determines whether or not the curl correction control HP sensor 40 is turned on within a predetermined time (S1103). The predetermined time is a time obtained by adding a margin to the time that the cam 35 makes one round. When the curl correction control HP sensor 40 is ON (YES in S1103), the CPU 301 determines that the elastic roller 22 and the metal roller 23 are in normal contact, and determines that no failure has occurred and the curl correction control motor. 200 is stopped (S1 1 14). Even when the sheet reaches the relay conveyance device, the curl correction control motor 200 remains stopped. Then, the CPU 301 controls the image forming unit 320 to perform print processing (S1105), and ends printing.

  On the other hand, if curl correction control HP sensor 40 is not ON (NO in S1103), CPU 301 determines that there is a failure due to slide plate 30 not moving to the home position, and stores the fact of failure in RAM 303. (S1106). At this time, since there is no problem in execution of image formation, the user is not notified of the occurrence of a failure. Then, the CPU 301 proceeds to the process of step S1104. Since the sheet can be conveyed even when the elastic roller 22 and the metal roller 23 are separated from each other, the print processing is performed after the curl correction control motor 200 is stopped.

  In this way, in the example shown in FIG. 7, when the printing process is started, it is determined whether or not the relay conveyance device 3, that is, the pressing mechanism is out of order.

  FIG. 8 is a flowchart for explaining another example of the failure determination of the pressing mechanism of the relay conveyance device shown in FIG.

  The CPU 301 determines whether the printer is turned on or the job is finished (S1201). Here, the CPU 301 determines the end of the job when the trailing edge of the last page of the sheet S conveyed to the sheet post-processing apparatus 1 </ b> C passes the buffer exit sensor 51.

  If the power is not turned on and the job is not finished (NO in S1201), CPU 301 waits. On the other hand, when the power is turned on or the job is finished (YES in S1201), the CPU 301 drives the curl correction control motor 200 to separate the elastic roller 22 and the metal roller 23 (step S1202).

Subsequently, the CPU 301 determines whether or not the curl correction control HP sensor 40 is turned off within a predetermined time (S1203). This predetermined time is the time obtained by adding a margin to the time the cam 35 rotates one round. When curl correction control HP sensor 40 is turned off (YES in S1203), CPU 301 stops curl correction control motor 200 (S1204) and ends the process.

  On the other hand, if curl correction control HP sensor 40 is not turned off (NO in S1203), CPU 301 determines that separation was not possible, and stores a failure (failure information) in RAM 303 (S1205). At this time, since there is no problem in execution of image formation, the user is not notified of the occurrence of a failure. Then, the CPU 301 proceeds to the process of step S1204.

  Even if it is determined that there is a failure, the end processing of the job can be continued, so the curl correction control motor 200 is stopped here. Further, the next job cannot be submitted unless the failure determination described in FIG. 8 is completed.

  FIG. 9 is a flowchart for explaining error determination when a paper jam occurs in the relay conveyance device 3 shown in FIG.

  First, as described above, the CPU 301 determines whether or not a paper jam (paper jam) has occurred in the relay conveyance device 3 (S1301). If no paper jam has occurred (NO in S1301), the CPU 301 stands by.

  On the other hand, when a paper jam occurs (YES in S1301), the CPU 301 determines whether or not the pressing mechanism of the relay conveyance device 3 has failed (S1302). Here, if failure information is registered in the RAM 303, the CPU 301 determines that a failure has occurred in the pressing mechanism.

  If it is determined that a failure has occurred in the pressing mechanism (YES in S1302), the CPU 301 is in a state where the pressing mechanism is locked according to the state of the curl correction control HP sensor 40 (that is, the locking mechanism is in the locked state). It is determined whether a paper jam has occurred or a paper jam has occurred in an unlocked state (S1303). Here, if the curl correction control HP sensor 40 is OFF, the CPU 301 determines that the pressing mechanism is not locked. On the other hand, if the curl correction control HP sensor 40 is ON, the CPU 301 determines that the pressing mechanism is locked.

If the pressing mechanism is in the locked state (YES in S1303), the CPU 301 indicates that, apart from the occurrence of a jam, the image formation cannot be restarted due to the failure of the pressing mechanism, and the pressing mechanism should be repaired. The notification is displayed on the screen of the operation unit 330 (S1304). Then, the CPU 301 prohibits the subsequent image forming operation (print job or the like) and ends the processing.

  If the pressing mechanism is not in the locked state (NO in S1303), the CPU 301 displays a notification for prompting a paper jam process on the operation unit 330 (S1305) and ends the process. If it is determined that the pressing mechanism has not failed (NO in S1302), the CPU 301 proceeds to the process of step S1305.

  Even when the printer is turned off while the pressing mechanism is broken, the failure determination described with reference to FIG. 8 is performed when the power is turned on. That is, since the failure state is determined again, the failure repair notification cannot be made.

  FIG. 10 is a diagram for explaining a notification displayed on the operation unit 330 in the error determination described with reference to FIG. FIG. 10A shows a paper jam processing notification, and FIG. 10B shows a failure repair notification.

  As shown in FIG. 10A, when a paper jam notification is made in step S1305 of FIG. 9, the operation unit 330 displays a message “Please remove the paper in the machine”. Thereafter, when the jam is eliminated, the image formation can be resumed even if the failure of the pressing mechanism is not eliminated.

  On the other hand, as shown in FIG. 10B, when a failure repair notification is made in step S1304 in FIG. 9, the operation unit 330 is notified that “the lock mechanism has failed. Please send a repair request.” The wording is displayed.

  As described above, according to the embodiment of the present invention, even when a failure occurs in the pressing mechanism provided in the relay conveyance device, the user is accurately notified whether it is paper jam processing or repair is necessary. Since it did in this way, use of a printer is not prohibited uniformly until it can use a printer. Therefore, user convenience can be improved.

  In other words, in the above-described embodiment, when a failure in which the pressing state cannot be changed is detected when controlling the pressing of the curl correction mechanism, the curl correction mechanism may be a failure that remains in the first pressing state. If this happens, the printer will not stop with an error. Then, the printing operation is continued without contacting the curl correction mechanism. On the other hand, if the curl correction mechanism is in the second pressed state, the printing operation is continued as it is. In this case, if a paper jam (sheet jam) occurs in the relay conveyance device, the sheet cannot be removed, and an error occurs.

  Therefore, it is possible to reduce cases where the printer main body is stopped when the curl correction mechanism (that is, the pressing mechanism) fails.

  As is clear from the above description, in the example shown in FIG. 2, the curl correction control HP sensor 40 and the CPU 301 function as abnormality detection means. The CPU 301 functions as a control unit. Furthermore, the CPU 301 and the operation unit 330 function as notification means.

  In the embodiment described above, in step S1106 in FIG. 7 and step S1205 in FIG. 8, even if a failure of the pressing mechanism is detected, the user is not immediately notified of the failure. However, when the image forming apparatus is connected to the network, the failure of the separation mechanism may be notified to a service center that manages the repair of the apparatus. If the situation in step S1304 in FIG. 9 is not established, the failure of the pressing mechanism is not always displayed on the operation unit to the user, for example, the failure is temporarily displayed when the apparatus is turned on. For example, a configuration that intermittently displays a failure may be used. Moreover, the structure which displays the failure of a press mechanism always or regularly in the area | region which displays the status of the apparatus provided in an operation part may be sufficient.

  As mentioned above, although this invention was demonstrated based on embodiment, this invention is not limited to these embodiment, Various forms of the range which does not deviate from the summary of this invention are also contained in this invention. .

  For example, the function of the above-described embodiment may be used as a control method, and the control method may be executed by the image forming apparatus. Further, a program having the functions of the above-described embodiments may be used as a control program, and the control program may be executed by a computer included in the image forming apparatus. The control program is recorded on a computer-readable recording medium, for example.

  Each of the control method and the control program has at least an abnormality detection step, a storage step, and a notification step.

  The present invention can also be realized by executing the following processing. That is, software (program) that realizes the functions of the above-described embodiments is supplied to a system or apparatus via a network or various recording media, and the computer (or CPU, MPU, etc.) of the system or apparatus reads the program. To be executed.

DESCRIPTION OF SYMBOLS 1A Paper discharge apparatus 1B Image reading apparatus 1C Post-processing apparatus 1 Printer main body 2 Image forming unit 3 Relay conveyance apparatus 4 Intermediate transfer body 4a Intermediate transfer belt 5a, 5b, 5c, 5d Process cartridge 6a, 6b, 6c, 6d Photosensitive drum

Claims (14)

Image forming means for forming an image on a sheet;
Jam detecting means for detecting a jam of a sheet in a conveyance path along which a sheet on which an image is formed by the image forming means is conveyed;
A cover that is opened and closed to remove a sheet when a jam occurs in the conveyance path;
A first pressing state that is arranged in the conveyance path and causes the first correction roller and the second correction roller to contact each other with a first pressing force or a second pressing force that is larger than the first pressing force. A curl correcting unit that includes a pressing unit configured to be in a second pressing state to be brought into contact, and corrects curl generated on the sheet by setting the first correction roller and the second correction roller to the second pressing state. When,
When the first correction roller and the second correction roller are in the second pressing state, the cover is locked in a closed state, and the first correction roller and the second correction roller are in the first state. Locking means for releasing the lock when in the pressed state ;
An anomaly detecting means for detecting an anomaly that is not unlocked by the locking means;
A control unit that permits execution of image formation in which a sheet is conveyed along the conveyance path if an abnormality that the lock is not released is detected by the abnormality detection unit and a jam is not detected by the jam detection unit;
An image forming apparatus comprising:   When the abnormality that the unlocking is not released by the abnormality detecting unit is detected and the jam is detected by the jam detecting unit, the control unit notifies that the image formation cannot be resumed because the lock is not released. The image forming apparatus according to claim 1. The abnormality detecting means further detects an abnormality that cannot be locked by the locking means,
When the abnormality detecting unit detects an abnormality that cannot be locked by the locking unit, if the jam detecting unit does not detect a jam, the control unit executes image formation in which the sheet is conveyed on the conveyance path. The image forming apparatus according to claim 1, further comprising:   In the case where an abnormality that cannot be locked by the locking means is detected by the abnormality detecting means, and a jam is detected by the jam detecting means, the control means may not be able to solve the abnormality that cannot be locked by the locking means. 3. The image forming apparatus according to claim 2, wherein when the jam is resolved, execution of image formation in which the sheet is conveyed along the conveyance path is permitted. A change unit that changes the first correction roller and the second correction roller from the second pressing state to the first pressing state when the image forming job is completed;
The abnormality detection means, the image forming apparatus according to claim 1, wherein the detecting whether abnormalities image forming job is not unlocked by the locking means and ends occurs. The abnormality detecting means further detects an abnormality that cannot be locked by the locking means,
When a jam is detected by the jam detection means, if an abnormality that the lock by the lock means is not released is detected by the abnormality detection means, it is notified that the lock means has failed, and the abnormality detection means The image forming apparatus according to claim 1, further comprising a notifying unit that notifies the occurrence of a jam if an abnormality that cannot be locked by the locking unit is detected. Image forming means for forming an image on a sheet;
The first pressing state in which the first correction roller and the second correction roller are brought into contact with the first pressing force or the first correction roller is disposed in a conveyance path along which the sheet on which an image is formed by the image forming unit is conveyed. A pressing unit configured to be in a second pressing state that is brought into contact with a second pressing force that is greater than the pressing force of 1, and the first correction roller and the second correction roller are set to the second pressing state. Curl correcting means for correcting the curl generated in the sheet,
A jam detecting means for detecting a jam of the sheet in the conveyance path;
An abnormality detection means for detecting an abnormality in which the first correction roller and the second correction roller do not change from the second pressing state to the first pressing state;
Control that permits execution of image formation in which a sheet is conveyed on the conveyance path when an abnormality that does not cause the first pressing state is detected by the abnormality detection unit and a jam is not detected by the jam detection unit Means,
An image forming apparatus comprising: When the abnormality that does not become the first pressing state is detected by the abnormality detection unit and a jam is detected by the jam detection unit, the control unit notifies that the image formation cannot be resumed due to the abnormality. 8. The image forming apparatus according to claim 7, wherein: The abnormality detection means further detects an abnormality in which the first correction roller and the second correction roller do not change from the first pressing state to the second pressing state,
When the abnormality detection unit detects an abnormality that does not result in the second pressing state, the control unit executes image formation in which a sheet is conveyed on the conveyance path if the jam detection unit does not detect a jam. 8. The image forming apparatus according to claim 7 , wherein the image forming apparatus is permitted. When the abnormality that does not enter the second pressing state is detected by the abnormality detecting unit and the jam is detected by the jam detecting unit, the control unit does not eliminate the abnormality that does not enter the second pressing state. The image forming apparatus according to claim 9, wherein when the jam is resolved, execution of image formation in which the sheet is conveyed along the conveyance path is permitted. The abnormality detection means further detects an abnormality in which the first correction roller and the second correction roller do not enter the second pressing state from the first pressing state,
When a jam is detected by the jam detection means, if an abnormality that does not result in the first pressing state is detected by the abnormality detection means, it is notified that the curl correction means is faulty, and the abnormality detection means 8. The image forming apparatus according to claim 7, further comprising a notifying unit that notifies the occurrence of a jam if an abnormality that does not cause the second pressing state is detected. A change unit that changes the first correction roller and the second correction roller from the second pressing state to the first pressing state when the image forming job is completed;
8. The image forming apparatus according to claim 7 , wherein the abnormality detecting unit detects whether or not an abnormality that does not result in the first pressing state occurs when an image forming job is completed. A cover that is opened and closed to remove a sheet when a sheet jam occurs in a conveyance path on which an image-formed sheet is conveyed, and a first correction roller and a second correction that are disposed in the conveyance path A first pressing state in which the roller is brought into contact with a first pressing force; or a second pressing state in which the roller is brought into contact with a second pressing force that is larger than the first pressing force. The curling correction means for correcting the curl generated in the sheet by bringing the correction roller and the second correction roller into the second pressing state, and the first correction roller and the second correction roller include the first correction roller and the second correction roller, respectively. Lock means for locking the cover in a closed state when in a second pressing state, and releasing the lock when the first correction roller and the second correction roller are in the first pressing state ; Have A control method of an image forming apparatus,
An abnormality detection step of detecting an abnormality in which the lock by the locking means is not released;
A storage step of storing in the storage means that an abnormality has been detected by the abnormality detection step;
A permission step for permitting execution of image formation in which a sheet is transported through the transport path if a jam is detected in the storage means even if it is stored that an abnormality is detected in the storage unit;
If it is detected that an abnormality has been detected in the storage means when a sheet jam is detected, the occurrence of a jam is informed and the storage means stores an abnormality detected. An informing step for informing a failure of the locking means;
A control method for an image forming apparatus, comprising: From a first pressing state in which the first correction roller and the second correction roller are brought into contact with the first pressing force, or the first pressing force, which is disposed in the transport path on which the sheet on which the image is formed is transported. Pressing means for bringing the second correction state into contact with the second pressing force having a larger second pressing force, and bringing the first correction roller and the second correction roller into the second pressing state to the sheet. In a control method of an image forming apparatus having a curl correction unit for correcting a generated curl,
An abnormality detection step of detecting an abnormality in which the first correction roller and the second correction roller do not change from the second pressed state to the first pressed state;
A storage step of storing in the storage means that an abnormality has been detected by the abnormality detection step;
A permission step for permitting execution of image formation in which a sheet is transported through the transport path if a jam is detected in the storage means even if it is stored that an abnormality is detected in the storage unit;
If it is detected that an abnormality has been detected in the storage means when a sheet jam is detected, the occurrence of a jam is informed and the storage means stores an abnormality detected. An informing step for informing a failure of the curl correcting means;
A control method for an image forming apparatus, comprising:

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