JP6686312B2 - Image forming apparatus and image forming system - Google Patents

Description

  The present invention relates to an image forming apparatus applied to a copying machine, a printer, a facsimile machine, and the like, and an image forming system including the image forming apparatus.

  In the image forming apparatus, first, the photoconductor is charged and the electric charge is erased in accordance with the original image, so-called exposure is performed to form an electrostatic latent image. A developer (toner) is attached to the electrostatic latent image on the photoconductor using a developing unit. Then, the image forming apparatus transfers the toner image adhering to the photoconductor onto a transfer material such as an intermediate transfer belt or paper, and fixes the transferred toner image on the paper by a fixing unit to form an image on the paper. There is. Further, the sheet on which the toner image is fixed is conveyed through the sheet conveying path.

  Further, when the sheet is conveyed in the image forming apparatus, there is a possibility that wrinkles (hereinafter referred to as “paper wrinkles”) may occur on the sheet due to the conveyance section such as the fixing section and the transfer section. In order to detect the occurrence of paper wrinkles, for example, a technique disclosed in Patent Document 1 is disclosed. The technique described in Patent Document 1 describes a detection device including a rotating body that winds up paper, a drive device that controls the rotation of the rotating body, and a load current detector that detects a load current of the drive device. Has been done. Then, the technique described in Patent Document 1 detects the occurrence of paper wrinkles by comparing the current value detected by the load current detector with the set current value.

JP, 2014-133625, A

  However, the image forming apparatus and the image forming system having the image forming apparatus are provided with a plurality of roller pairs for conveying the paper. Therefore, in order to identify the roller pairs that cause paper wrinkles using the technique described in Patent Document 1, it is necessary to provide a load current detector in the drive device for all roller pairs. As a result, the technique described in Patent Document 1 has a problem that the device becomes large and complicated.

  SUMMARY OF THE INVENTION The present invention has been made in view of the above-described conventional problems, and an object of the present invention is to provide an image forming apparatus and an image forming system capable of specifying a location where paper wrinkles occur with a simple configuration.

In order to solve the above problems and achieve the object of the invention, the image forming apparatus of the invention conveys a sheet, and a plurality of roller pairs capable of pressure contact and separation, a sheet deformation detection section, and a control section, Is equipped with. The paper deformation detection unit is disposed on the downstream side of the plurality of roller pairs in the paper conveyance direction, and detects paper deformation. The controller separates a roller pair other than the predetermined roller pair from the plurality of roller pairs when the paper deformation detector detects the deformation of the sheet. Further, the control unit specifies the deformation position of the paper based on the detection signal of the paper deformation detection unit when the deformation of the paper is resolved after the paper is conveyed with the predetermined roller pair separated . When the deformation of the sheet is not eliminated, the sheet is conveyed after pressing a predetermined pair of separated rollers and pressing a roller pair different from the other separated roller pairs of the plurality of roller pairs. The position of deformation of the paper is specified based on the detection signal of the paper deformation detector.

  Further, the image forming system of the present invention includes an image forming apparatus that forms an image on a sheet, a sheet feeding apparatus that supplies the sheet to the image forming apparatus, and a plurality of roller pairs that convey the sheet and that can be pressed and separated. A paper deformation detection unit and a control unit are provided. The paper deformation detection unit and control unit use the paper deformation detection unit and control unit described above.

  According to the image forming apparatus and the image forming system having the above-described configurations, it is possible to identify the location of paper wrinkles with a simple configuration.

1 is a schematic configuration diagram of an image forming system according to an exemplary embodiment of the present invention. FIG. 3 is a block diagram showing a configuration of a control system in the image forming system according to the exemplary embodiment of the present invention. 7 is a flowchart showing an example of a paper wrinkle occurrence place specifying operation process in the image forming system according to the exemplary embodiment of the present invention. FIG. 6 is an explanatory diagram showing an example of an operation of identifying a place where paper wrinkles occur in the image forming system according to the exemplary embodiment of the present invention. FIG. 6 is an explanatory diagram showing an example of an operation of identifying a place where paper wrinkles occur in the image forming system according to the exemplary embodiment of the present invention. 8 is a flowchart showing a preliminary operation of a specific operation process of a place where paper wrinkles occur in the image forming system according to the exemplary embodiment of the present invention. 7 is a flowchart showing another example of the operation of identifying the location of paper wrinkles in the image forming system according to the exemplary embodiment of the present invention.

  Hereinafter, modes for carrying out the image forming apparatus and the image forming system of the present invention will be described with reference to FIGS. In each figure, common members are designated by the same reference numerals. Moreover, the present invention is not limited to the following modes.

1-1. Configuration of Image Forming System First, an image forming system according to a first embodiment of the present invention (hereinafter referred to as “this example”) will be described with reference to FIGS.
FIG. 1 is a schematic configuration diagram of an image forming system.

  As illustrated in FIG. 1, the image forming system 100 includes an image forming apparatus 1, a sheet feeding device 2 that supplies a roll sheet S that is an example of a sheet to the image forming apparatus 1, and a roll that is ejected from the image forming apparatus 1. A paper discharge device 3 for winding the paper S is provided. The image forming system 100 also includes a paper feed adjusting device 4, a paper discharge adjusting device 5, and a paper processing device 6. The paper feed adjusting device 4 is arranged between the paper feed device 2 and the image forming apparatus 1. The paper discharge adjusting device 5 and the paper processing device 6 are arranged between the image forming device 1 and the paper discharging device 3.

  The image forming apparatus 1 forms an image on a roll paper S by an electrophotographic method, and is a tandem that superimposes four color toners of yellow (Y), magenta (M), cyan (C), and black (K). This is a color image forming apparatus of a type.

  The image forming apparatus 1 includes an apparatus main body 25, a document conveying unit 20, an image reading unit 30 (see FIG. 2), an image forming unit 40, an intermediate transfer belt 50, a secondary transfer unit 70, and a fixing unit 10. The operation display unit 65, the control unit 60, and the paper storage unit 24 are provided. Further, in the image forming apparatus 1, the paper feeding unit 80 in which the roll paper S is fed into the apparatus main body 25 from the paper feeding apparatus 2 and the paper feeding adjusting apparatus 4, and the paper ejection adjusting apparatus 5 and the paper ejecting apparatus 3 from the apparatus main body 25. It has a paper discharge unit 90 for discharging the roll paper S and a transport unit 23 for transporting the roll paper S.

  The transport unit 23, the paper storage unit 24, the image forming unit 40, the intermediate transfer belt 50, the secondary transfer unit 70, the fixing unit 10, the control unit 60, the paper feeding unit 80, and the paper discharging unit 90 are housed in the apparatus main body 25. Has been done.

  The paper feeding unit 80 is composed of a pair of rollers 81 and 82. The roller pairs 81 and 82 that configure the paper feeding unit 80 are configured to be capable of being pressed and separated from each other. The roll paper S conveyed from the paper feed adjusting device 4 described later is fed to the paper feed unit 80. Further, the transport unit 23 is provided on the downstream side of the paper feeding unit 80.

  The transport unit 23 includes a plurality of roller pairs. The transport unit 23 transports the roll paper S fed into the paper feed unit 80 to the secondary transfer unit 70 described below. In addition, the plurality of roller pairs that form the transport unit 23 are configured to be capable of pressure contact and separation.

  A paper storage unit 24 is arranged below the apparatus main body 25. The paper storage unit 24 stores paper different from the roll paper S. The image forming system 100 properly uses the paper stored in the paper storage unit 24 or the roll paper S stored in the paper feeding device 2 according to the purpose. When using the paper stored in the paper storage unit 24, the paper stored in the paper storage unit 24 is transported to the secondary transfer unit 70 by the transport unit 23.

  The document feeder 20 is arranged on the upper part of the apparatus body 25. The document feeding unit 20 has a document feeding table 21 for setting a document, a document discharging tray 22, and a plurality of rollers. The originals set on the original feeding table 21 are conveyed one by one to the reading position of the image reading unit 30 by a plurality of rollers. The document read by the image reading unit 30 is discharged to the document discharge tray 22.

  The image reading unit 30 reads an image of the original document conveyed by the original document conveyance unit 20 or the original document placed on the original document feed table 21, and generates image data. An image on one side or both sides of the document conveyed to the image reading unit 30 is exposed by an optical system and is read by an image sensor.

  The analog signal photoelectrically converted by the image sensor is subjected to various kinds of processing such as analog processing, A / D conversion processing, shade ink correction processing, and image compression processing in the image processing unit. Then, the image signal subjected to various signal processing is sent from the image processing unit to the image forming unit 40.

  The image signal sent to the image forming unit 40 is not limited to the image signal output from the image reading unit 30, but is received from an external device such as a personal computer connected to the image forming apparatus 1 or another image forming apparatus. It may be one.

  The image forming unit 40 has four image forming units 40Y, 40M, 40C, and 40K for forming toner images of respective colors of yellow (Y), magenta (M), cyan (C), and black (K). .

  The first image forming unit 40Y forms a yellow toner image, and the second image forming unit 40M forms a magenta toner image. The third image forming unit 40C forms a cyan toner image, and the fourth image forming unit 40K forms a black toner image. Since the four image forming units 40Y, 40M, 40C, and 40K have the same configuration, only the first image forming unit 40Y will be described here as a representative.

  The first image forming unit 40Y includes a drum-shaped photoconductor 41, a charging unit arranged around the photoconductor 41, an exposure unit, a developing unit 44, and a cleaning device. The photoconductor 41 is rotated counterclockwise by a drive motor (not shown). The charging unit applies a charge to the photoconductor to uniformly charge the surface of the photoconductor. The exposure unit forms an electrostatic latent image on the photoconductor 41 by performing exposure scanning on the surface of the photoconductor 41 based on image data transmitted from the outside.

  The developing unit 44 attaches yellow toner to the electrostatic latent image formed on the photoconductor 41. As a result, a yellow toner image is formed on the surface of the photoconductor 41. The developing unit 44 of the second image forming unit 40M attaches magenta toner to the photoconductor 41, and the developing unit 44 of the third image forming unit 40C attaches cyan toner to the photoconductor 41. Then, the developing unit 44 of the fourth image forming unit 40K attaches black toner to the photoconductor 41.

  The toner attached on the photoconductor 41 is transferred to the intermediate transfer belt 50. The cleaning device removes the toner remaining on the surface of the photoconductor 41 after the transfer to the intermediate transfer belt 50.

  The intermediate transfer belt 50 is formed in an endless shape, and is rotated clockwise by a drive motor (not shown) in a direction opposite to the rotation direction of the photoconductor 41. A primary transfer portion is provided on the intermediate transfer belt 50 at a position facing the photoconductor 41 of each of the image forming units 40Y, 40M, 40C, and 40K. The primary transfer portion transfers the toner image formed on the photoconductor 41 to the intermediate transfer belt 50 by applying a polarity opposite to that of the toner to the intermediate transfer belt 50.

  Then, as the intermediate transfer belt 50 rotates, the toner images formed by the four image forming units 40Y, 40M, 40C, and 40K are sequentially transferred onto the surface of the intermediate transfer belt 50. As a result, the yellow, magenta, cyan, and black toner images are overlapped on the intermediate transfer belt 50 to form a color image.

  A secondary transfer unit 70 is arranged near the intermediate transfer belt 50 and on the downstream side of the transport unit 23. The secondary transfer section 70 is composed of a transfer roller pair including a transfer upper roller 71 on which the intermediate transfer belt 50 is stretched and a transfer lower roller 72 pressed by the intermediate transfer belt 50 toward the transfer upper roller side. There is. The upper transfer roller 71 and the lower transfer roller 72 that process the secondary transfer portion 70 are configured to be capable of being pressed into contact with and separated from each other with the intermediate transfer belt 50 interposed therebetween.

  In the secondary transfer portion 70, the roll paper S conveyed from the conveying portion 23 is pressed by the transfer lower roller 72 toward the intermediate transfer belt 50. Then, the secondary transfer section 70 transfers the color toner image formed on the intermediate transfer belt 50 onto the roll paper S sent from the transport section 23.

  The fixing unit 10 is provided on the discharge side of the roll paper S in the secondary transfer unit 70. The fixing unit 10 includes a fixing belt 11 and a pressure roller 14 that is a pressure member. The fixing belt 11 is composed of an endless elastic member, and is supported and stretched by a fixing roller 12 which is a driving roller and a heating roller 13 which is a driven roller.

  Then, a fixing nip portion is formed at a portion where the fixing roller 12 and the pressure roller 14 contact each other via the fixing belt 11. When the roll paper S carrying the toner image passes through the fixing nip portion of the fixing section 10, the toner is melted by the fixing belt 11 and the pressure roller 14 controlled to a predetermined temperature and is fixed on the roll paper S.

  Further, the fixing roller 12 and the pressure roller 14 are configured to be capable of being brought into pressure contact with and separated from each other with the fixing belt 11 interposed therebetween.

  A paper discharge unit 90 is provided on the downstream side of the fixing unit 10. The paper discharge unit 90 is composed of a pair of rollers 91 and 92, like the paper supply unit 80. The roller pairs 91 and 92 that configure the paper discharge unit 90 are configured to be capable of pressure contact and separation. The paper discharge unit 90 discharges the roll paper S having the toner image fixed by the fixing unit 10 from the apparatus main body 25 toward the paper discharge adjusting device 5.

  The operation display unit 65 is a touch panel including a display such as a liquid crystal display (LCD) or an organic ELD (Electro Luminescence Display). The operation display unit 65 displays an instruction menu for the user, information regarding the acquired image data, and the like. Further, the operation display unit 65 has a plurality of keys, and serves as an input unit that receives input of data such as various instructions, characters, and numbers by a user's key operation.

  The control unit 60 operates each unit of the image forming apparatus 1 according to an instruction from the operation display unit 65 or an externally connected personal computer 120 (see FIG. 2).

[Paper feeder / Paper ejector]
Next, the sheet feeding device 2 and the sheet discharging device 3 will be described. The paper feeding device 2 includes a roll paper setting unit 222 and a transport unit 221. A desired roll paper body 220 is rotatably installed in the roll paper installation unit 222. The transport unit 221 includes a plurality of transport rollers and transports the roll paper S discharged from the roll paper setting unit 222 to the paper feed adjusting device 4.

  The paper discharge device 3 includes a transport unit 331 and a winding unit 332. The transport unit 331 includes a plurality of transport rollers and transports the roll paper S discharged to the paper discharge device 3 to the winding unit 332. The winding unit 332 winds the conveyed roll paper S into a roll.

[Paper feed adjustment device / Paper ejection adjustment device]
Next, the paper feed adjusting device 4 and the paper discharge adjusting device 5 will be described. The paper feed adjusting device 4 is disposed between the paper feed device 2 and the image forming apparatus 1 and intentionally loosens the roll paper S conveyed from the paper feed device 2. Further, the paper discharge adjusting device 5 is disposed between the image forming device 1 and the paper processing device 6 and intentionally loosens the roll paper S discharged from the image forming device 1. Then, the paper feed adjusting device 4 and the paper discharge adjusting device 5 intentionally loosen the roll paper so that the roll paper S is transported between the devices in the transport direction and the transport speed of the roller pair provided in each device. Adjust the gap.

  The paper feed adjusting device 4 has an upstream side transport unit 401 and a downstream side transport unit 402. Similarly, the paper discharge adjusting device 5 also includes an upstream-side transport unit 501 and a downstream-side transport unit 502. The upstream side transport units 401 and 501 and the downstream side transport units 402 and 502 are composed of a pair of rollers. Then, the roll paper S is slackened between the upstream side transport units 401 and 501 and the downstream side transport units 402 and 502.

  Further, the paper discharge adjusting device 5 is provided with a paper slack detecting unit 503 that detects a slack state of the roll paper S. The paper slack detecting unit 503, which is an example of the paper length estimating unit, is disposed below the paper discharge adjusting device 5 between the upstream transport unit 501 and the downstream transport unit 502. The paper slack detection unit 503 detects the slack state of the roll paper S by measuring the distance to the roll paper S passing between the upstream-side transport unit 501 and the downstream-side transport unit 502.

[Paper processing equipment]
Next, the paper processing device 6 will be described. The paper processing device 6 is arranged between the paper ejection adjusting device 5 and the paper ejection device 3. The sheet processing device 6 performs a predetermined processing process such as punching, folding, and stapling on the roll paper S conveyed from the paper discharge adjusting device 5.

  The paper processing device 6 is provided with a paper deformation detection unit 601. The paper deformation detection unit 601 is, for example, an image sensor such as a CCD camera or a COMS (including a MOS type). Then, the paper deformation detection unit 601 detects the deformation of the roll paper S by photographing the conveyed roll paper S and comparing the photographed image information with the paper deformation information stored in advance.

  The paper deformation detection unit 601 of this example is also used as a correction patch detection unit that detects a correction patch for stabilizing the image quality. As a result, by using the paper deformation detection unit 601 as the correction patch detection unit, it is possible to reduce the number of parts.

  In the image forming system 100 of the present example, an example in which an image sensor for photographing the roll paper S is applied as the paper deformation detection unit 601 has been described, but the present invention is not limited to this. The paper deformation detection unit 601 is, for example, an optical type that is arranged in a straight line over a part or the whole of a direction (paper width direction) that is orthogonal to the transport direction of the roll paper S and is parallel to one surface of the roll paper S. Various types of sensors such as a line sensor, a mechanical detection sensor that detects paper wrinkles by directly contacting the roll paper S, and the like can be applied.

  In the image forming system 100 of this example, an example in which the paper deformation detection unit 601 is provided in the paper processing device 6 has been described, but the present invention is not limited to this. For example, the paper deformation detection unit 601 may be provided in the paper discharge adjusting device 5 or the image forming device 1. The paper deformation detection unit 601 may be provided on the downstream side of the location where paper wrinkles occur.

  Here, in the conventional image forming apparatus, the occurrence of paper wrinkles is detected by detecting the load current of the driving device of the roller pair. For this reason, in the conventional image forming apparatus, the vibration generated in the roller pair and the change in the load current caused by the thickness of the paper and the like are also detected as paper wrinkles. As a result, the conventional image forming apparatus has a problem that the paper wrinkle detection accuracy is low. On the other hand, in the image forming system 100 of this example, the occurrence of paper wrinkles is detected by directly observing the state of the roll paper S using the paper deformation detection unit 601. As a result, the occurrence of paper wrinkles can be detected without being affected by the vibration of the apparatus and the thickness of the paper, and the paper wrinkle detection accuracy can be improved.

1-2. Configuration of Control System of Image Forming System Next, the control system of the image forming system 100 will be described with reference to FIG.
FIG. 2 is a block diagram illustrating a hardware configuration example of each unit of the image forming system 100. In addition, in this block diagram, elements considered necessary for the description of the present invention or their related elements are described, and the image forming system 100 is not limited to this example.

  The image forming system 100 includes a control unit 60 in the image forming apparatus 1 as shown in FIG. The control unit 60 is connected to the communication unit 66, the image reading unit 30, the image processing unit 36, the image forming unit 40, the conveyance unit 23, and the fixing unit 10 via the system bus 107. Further, the control unit 60 is connected to the HDD (Hard Disk Drive) 64, the operation display unit 65, the paper deformation detection unit 601 and the paper slack detection unit 503 via the system bus 107.

  The control unit 60 includes, for example, a CPU (Central Processing Unit) 61, a ROM (Read Only Memory) 62 for storing programs executed by the CPU 61 and various data, and a RAM (Random Access) used as a work area of the CPU 61. Memory) 63. For example, the ROM 62 stores a roller deterioration state table. As the ROM 62, for example, an electrically erasable programmable ROM is used. The control unit 60 controls each block, that is, controls the entire device.

  The HDD 64 stores the image data of the document image read by the image reading unit 30 and the output image data and the like. The operation display unit 65 is a touch panel including a display such as a liquid crystal display (LCD) or an organic ELD (Electro Luminescence Display). The operation display unit 65 is an example of an output unit, and displays an instruction menu for the user, information regarding acquired image data, and the like. Further, the operation display unit 65 is provided with a plurality of keys, receives input of data such as various instructions, characters, and numbers by a user's key operation, and outputs an input signal to the control unit 60.

  The image data generated by the image reading unit 30 and the image data transmitted from a PC (personal computer) 120, which is an example of an external device connected to the image forming apparatus 1, are transmitted to the image processing unit 36 and undergo image processing. To be done. The image processing unit 36 performs image processing such as shading correction, image density adjustment, and image compression on the received image data as necessary.

  The image forming unit 40 receives the image data subjected to the image processing by the image processing unit 36, and forms an image on the roll paper S based on the image data.

  The transport unit 23 is driven and controlled by the control unit 60, and transports the paper stored in the paper storage unit 24 or the roll paper S transported from the paper feeding device 2.

  The fixing unit 10 is drive-controlled by the control unit 60, and heats and pressurizes the roll paper S while sandwiching and transporting the roll paper S conveyed to the fixing nip portion to fix the toner image on the roll paper S.

  The communication unit 66 receives, for example, job data transmitted from the PC 120, which is an external information processing device, via a communication line. Then, the received job data is sent to the CPU 61 via the system bus 107.

  The paper deformation detection unit 601 detects the state of the roll paper S that has been conveyed, and detects the occurrence of paper wrinkles. Then, the detection signal detected by the paper deformation detection unit 601 is transmitted to the control unit 60 via the system bus 107. The control unit 60, based on the detection signal received from the paper deformation detection unit 601, presses and presses the roller pair forming the transport unit 23, the paper feeding unit 80, the paper discharging unit 90, the fixing unit 10, and the secondary transfer unit 70. Control the separation.

  The paper slack detection unit 503 detects a slack state of the roll paper S conveyed to the paper discharge adjusting device 5. The detection signal detected by the paper slack detecting unit 503 is transmitted to the control unit 60 via the system bus 107. The control unit 60 controls the transport speeds of the upstream transport unit 501 and the downstream transport unit 502 of the paper discharge adjusting device 5, that is, the rotation speeds of the roller pairs, based on the detection signal received from the paper slack detection unit 503. As a result, the slack state of the roll paper S conveyed to the paper discharge adjusting device 5 is adjusted.

  In the present embodiment, an example in which a personal computer is applied as an external device has been described, but the present invention is not limited to this, and as the external device, for example, a facsimile device or other various devices can be applied. .

2. Example of Paper Wrinkle Occurrence Location Identification Operation Next, an example of paper wrinkle occurrence location identification operation processing in the image forming system 100 having the above-described configuration will be described with reference to FIGS.
FIG. 3 is a flowchart showing an example of a paper wrinkle occurrence place specifying operation, and FIGS. 4 and 5 are explanatory diagrams showing an example of a paper wrinkle occurrence place specifying operation.

  When the paper deformation detection unit 601 detects the deformation (paper wrinkle) of the conveyed roll paper S, the control unit 60 executes a specific operation of the place where the paper wrinkle has occurred. As shown in FIG. 3, first, the control unit 60 stops the image forming process in the image forming apparatus 1. Further, the control unit 60 continuously conveys the roll paper S (step S11).

  That is, the process of forming the toner image on the intermediate transfer belt 50 by the image forming unit 40 is stopped, but the roll paper S in the paper feed unit 80, the transport unit 23, the secondary transfer unit 70, the fixing unit 10, and the paper discharge unit 90 is stopped. The carrying operation of is continuously performed. Therefore, the roll paper S is conveyed to the paper discharge adjusting device 5 and the paper processing device 6 in a state where paper wrinkles are generated at the location causing the roll paper S.

  Next, the control unit 60 releases pressure contact of a roller pair that conveys the roll paper S except for a predetermined roller pair, and starts time measurement (step S12). In the specific operation of the present example, as shown in FIG. 4, the roller pair 81 and 82 of the paper feeding unit 80, which is the most upstream side of the sheet transportation in the image forming apparatus 1, and the paper discharging unit, which is the most downstream side of the sheet transportation. The roller pairs other than the roller pair 91 and 92 of 90 are separated. That is, the upper transfer roller 71 and the lower transfer roller 72 that form the secondary transfer unit 70 are separated from each other, and the fixing roller 12 and the pressure roller 14 that form the fixing unit 10 are separated from each other.

  Here, the roller pairs 81 and 82 of the sheet feeding section 80 which is the most upstream side sheet transporting means and the roller pairs 91 and 92 of the sheet discharging section 90 which is the most downstream sheet transporting means are pressed against each other. If so, the transport of the roll paper S is ensured. Depending on the curved state of the transport path for transporting the roll paper S, the transport length L, and the like, even if only the roller pair 91, 92 of the paper discharge unit 90, which is the transport means on the most downstream side of the paper transport, are pressed. The paper S can be transported. Therefore, only the roller pairs 91 and 92 of the paper discharge unit 90 may be pressed against each other, and the pressure contact of the other roller pairs may be released to separate the roller pairs.

  The time is measured at the same time when the pressure contact between the transfer upper roller 71 and the transfer lower roller 72 and the pressure contact between the fixing roller 12 and the pressure roller 14 are released.

  Next, the control unit 60 determines whether the deformation of the roll paper S has been eliminated based on the detection signal transmitted from the paper deformation detection unit 601 (step S13). In the process of step S13, when the control unit 60 determines that the paper wrinkle of the roll paper S has not been eliminated (NO determination in step S13), the location of the paper wrinkle is in contact with the roll paper S. It can be seen that there is a place other than the roller pair where the pressure contact is released, that is, the roller pair which is in contact with the roll paper S and where the pressure contact is not released.

  Therefore, the control unit 60 presses the roller pair released from the pressure contact in the process of step S12 and releases the pressure contact of another roller pair. Further, the control unit 60 resets the time measured in the process of step S12 and restarts the time measurement (step S14). In the specific operation of this example, as shown in FIG. 5, the roller pairs 81 and 82 of the sheet feeding unit 80 and the roller pairs 91 and 92 of the sheet discharging unit 90, which are in pressure contact with each other in the process of step S12, are separated from each other. Then, the transfer upper roller 71 and the transfer lower roller 72, which have been separated in the process of step S12, are brought into pressure contact with each other, and the fixing roller 12 and the pressure roller 14 constituting the fixing unit 10 are brought into contact with each other.

  Next, the control unit 60 determines whether the deformation of the roll paper S has been eliminated based on the detection signal transmitted from the paper deformation detection unit 601 (step S15). In the process of step S15, when the control unit 60 determines that the wrinkle of the roll paper S is not eliminated (NO determination in step S15), the control unit 60 performs the pressure contact in the processes of step S12 and step S14. It is specified that paper wrinkles have occurred in the remaining roller pairs that have not been released (step S16).

  Further, in the processing of step S13 and the processing of step S15, when the control unit 60 determines that the paper wrinkle of the roll paper S has been eliminated (in the case of YES determination in step S13 and step S15), the control unit 60 is abnormal. The location of occurrence is specified from the time until the solution and the transportation speed (step S17). That is, when the paper deformation detecting unit 601 detects the elimination of the paper wrinkle, which roller pair among the roller pairs released from the pressure contact caused the paper wrinkle based on the measured time from the pressure release to the elimination of the paper wrinkle. The control unit 60 specifies.

  For example, when the conveyance speed of the image forming system 100 is 300 mm / s, when the paper deformation detection unit 601 detects the elimination of the paper wrinkle 2 seconds after the press contact release operation, the location of the paper wrinkle is the paper deformation detection unit 601. The control unit 60 determines that the roller pair is arranged in the vicinity of 600 mm, which is a distance of 300 mm / s × 2 s.

  This makes it possible to identify the location of paper wrinkles with a simple configuration and prevent the image forming apparatus 1 and the image forming system 100 from becoming large and complicated. Further, by sequentially changing the pair of rollers for releasing the pressure contact, it becomes possible to identify the locations of all the transport paths for transporting the roll paper S.

  The order of the roller pair for releasing the pressure contact and the roller pair for releasing the pressure contact are not limited to the above-mentioned roller pair, and for example, the pressure contact of the roller pair of the transport unit 23 may be released. In addition, by first separating the roller pair at the location where paper wrinkles are likely to occur, the location of occurrence can be quickly identified. As described above, the order of the pair of rollers to be released from the pressure contact may be appropriately set by the user, or may be appropriately set according to the curved state of the transport path or the transport length.

  Furthermore, even for a roller pair that does not have the pressure contact and separation mechanism, when the other roller pair is separated and it is possible to specify that the separated roller pair is not at the place of occurrence, the pressure contact and separation mechanism is provided. It can be determined that there are not the remaining roller pairs.

  When the location of the paper wrinkle is specified in the processing of steps S16 and S17, the control unit 60 executes a countermeasure operation against the paper wrinkle (step S18). As the countermeasure operation, for example, the place of occurrence may be displayed on the operation display unit 65 to notify the user, or a measure depending on the place of occurrence, such as load adjustment of the roller pair at the place of occurrence, alignment adjustment, or rotation speed adjustment. Is appropriately performed. Further, when the control unit 60 determines that there is a risk of damage to the component at the location of occurrence, the control unit 60 may notify the user of that fact.

  As a result, the operation of identifying the location of the paper wrinkle in the image forming system 100 of this example ends. It should be noted that the specific operation described above may be made selectable by the user operating the operation display unit 65.

  The paper deformation detection unit 601 of this example is an image sensor such as a CCD camera or a COMS (including MOS type). Therefore, the operation of estimating the occurrence location may be performed using the image information captured by the paper deformation detection unit 601 before performing the above-described operation of identifying the location of the paper wrinkle. For example, if a paper wrinkle occurs before the unfixed image is transferred to the roll paper S, the paper wrinkle on the roll paper S causes no toner to adhere to the creaseed portion.

  Therefore, it can be determined from the image information captured by the paper deformation detection unit 601 that paper wrinkles have occurred on the upstream side of the secondary transfer unit 70 and the fixing unit 10 in the transport direction. Then, the control unit 60 releases the pressure contact of the roller pair on the upstream side of the secondary transfer unit 70 and the fixing unit 10, thereby executing the operation of identifying the location of paper wrinkles. As a result, the location of paper wrinkles can be identified quickly, and the identification accuracy can be improved.

3. Preliminary Operation for Specifying Paper Wrinkle Occurrence Location Next, the preliminary operation for the paper wrinkle occurrence location identification operation process will be described with reference to FIG.
FIG. 6 is a flowchart showing a preliminary operation of the specific operation processing of the paper wrinkle occurrence place.

  In the specific operation process shown in FIG. 3, the occurrence location is identified by calculating the distance of the occurrence location from the paper deformation detection unit 601 from the time when the paper wrinkle is eliminated. Therefore, the control unit 60 estimates the length of the roll paper S up to the paper deformation detection unit 601 in consideration of the slack state of the roll paper S detected by the paper slack detection unit 503, and the paper deformation detection unit 601 generates the occurrence location. To calculate the distance. As a result, it is possible to more accurately specify the location where the paper wrinkle has occurred.

  On the other hand, in the preliminary operation shown in FIG. 6, when the occurrence of paper wrinkles is detected, the slack of the roll paper S is eliminated, and the accuracy of specifying the occurrence location is improved. As shown in FIG. 6, first, the control unit 60 stops the conveyance of the roll paper S, and stops the rotation of the roller pair of the upstream side conveyance unit 501 in the paper ejection adjusting device 5 (step S21).

  Next, the control unit 60 rotates the roller pair of the downstream side transport unit 502 of the paper discharge adjusting device 5 (step S22). Thus, in the paper discharge adjusting device 5, the upstream side of the roll paper S is fixed by the upstream transport unit 501, and the roll paper S fed between the upstream transport unit 501 and the downstream transport unit 502 is discharged. It is conveyed from the paper adjusting device 5. As a result, in the paper discharge adjusting device 5, the slack of the roll paper S between the upstream side transport unit 501 and the downstream side transport unit 502 is eliminated.

  Next, the control unit 60 determines whether the slack has been eliminated based on the detection signal from the paper slack detecting unit 503 (step S23). In the process of step S23, when the control unit 60 determines that the looseness of the paper has been eliminated (YES in step S23), the control unit 60 executes the location specifying operation shown in FIG.

  Further, in the process of step S23, when the control unit 60 determines that the looseness of the paper is not eliminated (NO determination in step S23), the control unit 60 continues the process of step S22.

  In this way, by eliminating the slack of the paper intentionally generated on the roll paper S, the length of the roll paper S from the paper deformation detection unit 601 to the location where the paper wrinkle occurs becomes clear. As a result, in the process of step S17 in the place specifying operation shown in FIG. 3, it is possible to improve the accuracy of the operation of specifying the place from the measurement time.

  Further, in the image forming system 100 of the present example, an example is described in which the slack elimination of the roll paper S is determined based on the detection signal of the paper slack detection unit 503, but the present invention is not limited to this. For example, elimination of the slack of the roll paper S may be detected from the time when the upstream side transport unit 501 is stopped and the downstream side transport unit 502 is rotationally driven. Further, a bearing with a torque limiter may be provided on the roller pair of the downstream side transport unit 502 to detect the elimination of the slack of the roll paper S from the torque applied to the roller pair, and various other methods can be applied. .

4. Another Example of Paper Wrinkle Occurrence Location Identifying Operation Next, another example of the paper wrinkle occurrence location identifying operation process in the image forming system 100 will be described with reference to FIG. 7.
FIG. 7 is a flowchart showing another example of the operation for identifying the location of paper wrinkles.

  In the specific operation illustrated in FIG. 3, the example in which the roll paper S, which is a long paper extending from the paper feed unit 80 to the paper discharge unit 90 of the image forming apparatus 1 is used as the paper to be conveyed, has been described. However, the operation for specifying the paper wrinkle occurrence place in this example is not limited to the long paper, and the length of the paper in the paper transport direction is from the paper feed unit 80 to the paper discharge unit 90 of the image forming apparatus 1. It can also be applied to paper that does not reach the maximum.

  As shown in FIG. 7, when the occurrence of paper wrinkles is detected, the control unit 60 stops the image forming process on the paper (step S31). Next, the control unit 60 releases the pressure contact of the predetermined roller pair in the image forming apparatus 1 (step S32). The roller pairs other than the predetermined roller pair are maintained in a pressure contact state. Next, the control unit 60 conveys one sheet (step S33).

  Then, the control unit 60 determines whether or not the deformation of the paper (paper wrinkle) is eliminated based on the detection signal of the paper deformation detection unit 601 (step S34). In the process of step S34, when the control unit 60 determines that the paper wrinkles have not been eliminated (NO in step S34), the location of the paper wrinkles is the roller pair in which the pressure contact is not released. I understand.

  Then, the control unit 60 releases the pressure contact of another roller pair that has not been pressure released in the process of step S32 (step S35). At this time, the roller pair released from the pressure contact in the process of step S32 is pressure contacted. Next, the control unit 60 conveys one sheet (step S36).

  Then, the control unit 60 determines whether or not the deformation of the paper (paper wrinkle) is eliminated based on the detection signal of the paper deformation detection unit 601 (step S37). In the process of step S37, when the control unit 60 determines that the paper wrinkles have not been eliminated (NO in step S37), the process returns to step S35 to release the pressure contact of another roller pair. To do. As described above, the control unit 60 sequentially releases the pressure contact of the roller pair that conveys the sheet in the image forming apparatus 1 until the sheet wrinkle is detected to be eliminated, and the process from step S35 to step S37 is performed. repeat.

  Further, in the processing of step S34 and step S37, when the control unit 60 determines that the paper wrinkle of the roll paper S is eliminated (in the case of YES determination in step S13 and step S15), the control unit 60. Specifies that the location of the paper wrinkle is near the roller pair from which the pressure contact has been released (step S38). Next, the control unit 60 executes a countermeasure operation against paper wrinkles (step S39). Since the process of step S39 is similar to the process of step S18 shown in FIG. 3, the description thereof will be omitted.

  As a result, the process for specifying the location of the paper wrinkle ends. As shown in FIG. 7, it is possible to specify the location of paper wrinkles even for a paper whose length in the paper transport direction does not reach from the paper feed unit 80 to the paper discharge unit 90.

  Heretofore, the embodiments of the image forming apparatus and the image forming system have been described, including the effects thereof. However, the image forming apparatus and the image forming system of the present invention are not limited to the above-described embodiments, and various modifications can be made without departing from the scope of the invention described in the claims. is there.

  In the above-described embodiment, the color image is formed using the four sets of image forming units 40Y, 40M, 40C, and 40L. However, the image forming apparatus uses one image forming unit to form a monochromatic image. May be formed.

  Further, in the above-described embodiment, the operation of specifying the paper wrinkle occurrence place in the image forming apparatus in the image forming system has been described, but the present invention is not limited to this. For example, the location of paper wrinkles may be specified from among a plurality of roller pairs provided in the devices from the paper feeding device 2 to the paper discharging device 3. At this time, the paper deformation detection unit is arranged on the downstream side of the most downstream roller pair among the plurality of roller pairs that are the target of specifying the generation place.

  DESCRIPTION OF SYMBOLS 1 ... Image forming apparatus, 2 ... Paper feeding apparatus, 3 ... Paper discharging apparatus, 4 ... Paper feeding adjusting apparatus, 5 ... Paper discharging adjusting apparatus, 6 ... Paper processing apparatus, 10 ... Fixing section, 12 ... Fixing roller (roller pair) ), 13 ... Heating roller, 14 ... Pressure roller (roller pair), 20 ... Original transport section, 23 ... Transport section (roller pair), 40 ... Image forming section, 50 ... Intermediate transfer belt, 60 ... Control section, 65 ... operation display section, 70 ... secondary transfer section, 71 ... transfer upper roller (roller pair), 72 ... transfer lower roller (roller pair), 80 ... sheet feeding section, 81, 82 ... roller pair, 90 ... sheet discharging section , 91, 92 ... Roller pair, 100 ... Image forming system, 503 ... Paper slack detecting section, 601 ... Paper deformation detecting section, S ... Roll paper (paper)

Claims (6)

A plurality of roller pairs that can convey paper and can be pressed and separated from each other,
A paper deformation detection unit that is arranged on the downstream side of the plurality of roller pairs in the sheet conveyance direction, and detects deformation of the paper;
When the paper deformation detection unit detects the deformation of the paper, a control unit that separates a roller pair other than a predetermined roller pair from the plurality of roller pairs,
If the deformation of the paper is resolved after the paper is conveyed in a state where the other pair of rollers are separated from each other, the control unit determines the deformation location of the paper based on the detection signal of the paper deformation detection unit. If the deformation of the sheet is not resolved, the separated roller pair is pressed and the separated roller pair different from the separated roller pair is separated from the plurality of roller pairs. An image forming apparatus that specifies a deformation place of the paper based on a detection signal of the paper deformation detection unit after the paper is conveyed. The control unit, based on time information from the separation of the other roller pair or a roller pair different from the other roller pair until the paper deformation detection unit detects elimination of deformation of the paper, The image forming apparatus according to claim 1, wherein a deformation location of the image forming apparatus is specified. The image forming apparatus according to claim 1, wherein the predetermined roller pair is a roller pair arranged at least on the most downstream side in the transport direction. The paper deformation detection unit detects the deformation of the paper by capturing an image of the paper,
The image forming apparatus according to claim 1, wherein the control unit selects a roller pair to be separated from the plurality of roller pairs based on image information captured by the paper deformation detection unit. A paper length estimation unit that is arranged upstream of the paper deformation detection unit in the transport direction and estimates the length of the paper to the paper deformation detection unit,
The image forming apparatus according to claim 1, wherein the control unit specifies a deformation place of the paper based on the detection signal of the paper deformation detection unit and the estimation signal estimated by the paper length estimation unit. An image forming apparatus that forms an image on a sheet,
A sheet feeding device for feeding the sheet to the image forming apparatus,
A plurality of roller pairs that convey the sheet and that can be pressed against and separated from each other;
A paper deformation detection unit that is arranged on the downstream side of the plurality of roller pairs in the sheet conveyance direction, and detects deformation of the paper;
When the paper deformation detection unit detects the deformation of the paper, a control unit that separates a roller pair other than a predetermined roller pair from the plurality of roller pairs,
When the control section conveys the sheet in a state where the other roller pair is separated and then the deformation of the sheet is resolved, the control section determines the deformation location of the sheet based on the detection signal of the sheet deformation detection section. If the deformation of the sheet is not eliminated, the separated roller pair is pressed and the separated roller pair different from the separated roller pair among the plurality of roller pairs is separated. An image forming system that specifies a deformation place of the paper based on a detection signal of the paper deformation detection unit after the paper is conveyed.

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