JP2008050087A - Image forming device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To eliminate a jam easily and appropriately when the jam occurs in an image forming device. <P>SOLUTION: The image forming device is configured to comprise a paper tray 30 for placing image forming media for forming an image, a paper ejecting tray 32 for placing the image forming media on which an image has been formed, a convey unit 27 for conveying the image forming media along a convey route from the paper tray 30 to the paper ejecting tray 32, a paper sensor 28 and a jam sensing part 10a for sensing occurrence of a jam of the image forming media occurred at a plurality of locations in the convey route, and a conveyance control part 12c to make the convey unit 27 to convey, when a jam is sensed in any of a plurality of locations, the image forming media existing at another location in the convey route to a particular position determined according to the former location. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an image forming apparatus that conveys an image forming medium and forms an image on the image forming medium, and more particularly, to a countermeasure technique when an image forming medium jam occurs in the image forming apparatus.

  2. Description of the Related Art Conventionally, image processing apparatuses that perform image formation such as printing on an image forming medium (also referred to as paper) such as paper and an OHP sheet are known. Some of such image processing apparatuses are designed to immediately stop the operation of the image processing apparatus when it is detected that the image forming medium is clogged inside, that is, a jam has occurred. In this case, the user can remove the jammed image forming medium and perform image formation again.

  In recent years, speeding up of image forming apparatuses has progressed, and a state in which a plurality of sheets are present in the transport path has occurred during image formation. In such an image forming apparatus, when a jam occurs, it is necessary to remove not only the sheet that caused the jam but also other sheets present in the transport path, which is troublesome. is there. In addition, paper other than the paper that caused the jam may have to be discarded, and there is a problem that the paper is wasted.

  On the other hand, if a jam occurs in the discharge section, if the subsequent sheet is discharged from a discharge section other than the discharge section, it must be discharged from the discharge section where the jam has occurred without immediately stopping. There has been known an image forming apparatus that continuously operates until it becomes necessary (see, for example, Patent Document 1).

JP 2005-99346 A

  However, in the invention described in Patent Document 1, in the case where there are a plurality of discharge units, when there is no need to use a failed discharge unit, the continuous operation can be continued. It cannot be applied to devices that do not have multiple devices. Therefore, in an apparatus having no plurality of discharge portions, it is necessary to take out the paper causing the jam and the paper remaining in the interior as in the conventional case, which is troublesome.

  In addition, when using a faulty discharge unit, the operation stops without continuing the continuous operation. There is a problem that it is necessary to take out the paper that is being used, which is troublesome.

  Furthermore, for example, in the case of a laser printer, depending on the state in which the operation is stopped, paper in the middle of fixing or paper that has been transferred but not fixed remains in the apparatus. At the time of removal, there is a possibility that the user or the inside of the apparatus is soiled by unfixed toner. Also, depending on the state in which the operation has stopped, it is very difficult to remove the paper remaining in the interior. For example, if the paper is forcibly removed, the paper will be torn, and paper fragments will remain inside the device. There is also a risk of it.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a technique capable of easily and appropriately eliminating a jam when a jam occurs in an image forming apparatus.

  To achieve the above object, an image forming apparatus according to a first aspect of the present invention mounts a first placing unit for placing an image forming medium for forming an image, and an image forming medium on which an image is formed. A second placing means for placing the image forming medium, a conveying means for carrying the image forming medium along a carrying path from the first placing means to the second placing means, and an image forming medium at a plurality of points in the carrying path. Jam detection means for detecting the occurrence of a jam and an image forming medium existing in a conveyance path other than the point when the occurrence of a jam at any of a plurality of points is detected. Transport control means for transporting by a transport means to a predetermined position determined accordingly.

  According to such an image forming apparatus, when occurrence of a jam is detected in the conveyance path, an image forming medium existing in the conveyance path other than the point where the occurrence of the jam is detected is determined according to the point. It can be conveyed to the position. For this reason, depending on the point at which the image forming medium is jammed, for example, the position of the first mounting unit, the position of the second mounting unit, the position where it is easy to remove the image forming medium on which the image is formed, etc. Therefore, the jam can be easily and appropriately eliminated.

  In the image forming apparatus, the transport control unit may stop the operation of the transport unit after transporting the image forming medium existing at a place other than the point where the occurrence of the jam is detected to a predetermined position. . According to such an image forming apparatus, when a jam occurs, the conveying operation can be appropriately stopped after the image forming medium is conveyed to a predetermined position.

  In the image forming apparatus, the predetermined position may be a position of the first mounting unit, a position of the second mounting unit, or a position where the image forming medium in the transport path can be easily removed. Good. According to such an image forming apparatus, when a jam occurs, it is not necessary to perform an operation for removing the image forming medium, or the image forming medium can be easily removed even when it is necessary to remove it.

  In the image forming apparatus, the conveyance control unit may cause the second loading unit to convey the image forming medium existing downstream of the conveyance path from the point where the occurrence of the jam is detected by the conveyance unit. Good. According to such an image forming apparatus, the image forming medium existing in the transport path at the time of occurrence of the jam can be easily obtained from the second placing unit.

  Further, in the image forming apparatus, the transport unit is in charge of transport of the image forming medium in each part of the transport path, and has a plurality of partial transport units that can perform transport operation independently of the other parts. The conveyance control unit operates one or a plurality of partial conveyance units in charge of a portion downstream of the conveyance path from a predetermined point where the occurrence of the jam is detected, and the image forming medium existing in the portion is second loaded. You may make it convey to a mounting means. According to such an image forming apparatus, when a jam occurs, the image forming medium existing in the transport path can be appropriately transported to the second placement unit.

  In the image forming apparatus, a transfer unit that faces the transport path and transfers the toner image to the image forming medium, and a fixing that faces the transport path and fixes the toner image transferred to the image forming medium. And the jam detecting means stop the operation of the fixing means after the image forming medium is conveyed through the fixing means when the occurrence of a jam at a point upstream of the fixing means is detected. It is also possible to further include a fixing control unit for causing the fixing. According to such an image forming apparatus, it is possible to fix the toner image on the image forming medium existing downstream from the jam occurrence point. Therefore, the user and the inside of the apparatus can be appropriately prevented from being stained by the image forming medium.

  In the image forming apparatus, the conveyance control unit may cause the first mounting unit to convey the image forming medium existing upstream from the point where the occurrence of the jam is detected by the conveyance unit. In such an image forming apparatus, it is possible to appropriately convey the image forming medium upstream from the jam occurrence point to the first placement unit. Therefore, the image forming medium can be easily obtained from the first placement unit. If no image is formed on the image forming medium, it can be used for image formation thereafter.

  Further, in the image forming apparatus, the transport unit is in charge of transport of the image forming medium in each part of the transport path, and has a plurality of partial transport units that can perform transport operation independently of the other parts. The conveyance control unit operates one or a plurality of partial conveyance units in charge of a portion upstream of the conveyance path from the point where the occurrence of the jam is detected, and the image forming medium existing in the portion is first loaded. You may make it convey to a means. In such an image forming apparatus, it is possible to appropriately convey the image forming medium upstream from the jam occurrence point to the first placement unit.

  In order to achieve the above object, the conveyance control method according to the second aspect of the present invention includes a first placing unit for placing an image forming medium for forming an image, and an image forming medium on which an image is formed. Of the image forming medium in the image processing apparatus comprising: a second mounting unit that mounts the image forming medium; and a transport unit that transports the image forming medium along a transport path from the first mounting unit to the second mounting unit. In the conveyance control method, a jam detection step for detecting occurrence of jam of an image forming medium at a plurality of points in a conveyance path and occurrence of jam at any one of the plurality of points are detected. And a transport control step of transporting the image forming medium existing in the transport path other than the point by a transport unit to a predetermined position determined according to the point. According to such a conveyance control method, when occurrence of a jam is detected in the conveyance path, an image forming medium existing in the conveyance path other than the point where the occurrence of the jam is detected is determined according to the point. It can be conveyed to the position. For this reason, depending on the point at which the image forming medium is jammed, for example, the position of the first mounting unit, the position of the second mounting unit, the position where it is easy to remove the image forming medium on which the image is formed, etc. Therefore, the jam can be easily and appropriately eliminated.

  Embodiments of the present invention will be described with reference to the drawings. The embodiments described below do not limit the invention according to the claims, and all the combinations of features described in the embodiments are not necessarily essential to the solution means of the invention. Absent.

  First, an electrophotographic printer as an example of an image forming apparatus according to a first embodiment of the present invention will be described.

  FIG. 1 is a functional configuration diagram of a printer according to an embodiment of the present invention.

  In the printer 1, a CPU (Central Processing Unit) 10, an input interface unit (input I / F unit) 11, a display processing unit 12, a communication interface unit (communication I / F unit) 13, and a ROM (Read Only Memory). ) 14, RAM (Random Access Memory) 15, EEPROM (Electrically Erasable Programmable Read-Only Memory) 16, and mechanism control unit 17 are connected via a bus 18.

  A key unit 19 is connected to the input I / F unit 11. The input I / F unit 11 outputs a signal from the key unit 19 to the CPU 10 as data. The key unit 19 includes a start button, a stop button, a numeric keypad, and the like provided on the housing 2 of the printer 1, and outputs a signal corresponding to the pressed button and key to the input I / F unit 11. The display processing unit 12 includes, for example, a VRAM (Video Random Access Memory), generates various image data under the control of the CPU 10, and outputs the image data to a liquid crystal display device (LCD) 20. The communication I / F unit 13 can be connected to an external device (such as a host device) via a network, and mediates data exchange with the external device via the network.

  The ROM 14 stores a program such as a boot program. The RAM 15 is used as an area for storing programs and data, or as a work area for storing data used for processing by the CPU 10. The EEPROM 16 is a rewritable nonvolatile memory, and stores various information that needs to be stored even when the printer 1 is not powered on.

  Based on the control of the CPU 10, the mechanism control unit 17 controls the operations of the image forming unit 21, a transport unit 27 as an example of a transport unit, and a paper sensor 28. The image forming unit 21 includes a photosensitive unit 22, an exposure unit 23, a developing unit 24, a transfer unit 25 as an example of a transfer unit, and a fixing unit 26 as an example of a fixing unit. Details of the units 22 to 26, the transport unit 27, and the paper sensor 28 will be described later.

  CPU10 controls operation | movement of each part 10-17. Further, the CPU 10 reads out a program stored in the ROM 14 to the RAM 15 and executes the program, whereby a jam detection unit 10a as an example of a jam detection unit, a conveyance control unit 10b as an example of a conveyance control unit, and a fixing control. The image forming control unit 10c as an example of the unit is configured to execute various processes.

  The jam detection unit 10 a receives the detection result from the paper sensor 28 via the mechanism control unit 17, and detects the occurrence of a jam at a plurality of detection points by the paper sensor 28. Further, when detecting the occurrence of a jam, the jam detection unit 10a notifies the conveyance control unit 10b that the jam has occurred. The conveyance control unit 10 b controls the conveyance unit 27 via the mechanism control unit 17 to execute conveyance of an image forming medium (also referred to as paper) such as paper or an OHP sheet. Further, when the conveyance control unit 10b receives a notification from the jam detection unit 10a that the occurrence of the jam has been detected, the conveyance unit 27 is set at a predetermined position determined according to the point at which the occurrence of the jam is detected. To transport the paper. The image forming control unit 10 c controls the image forming unit 21 via the mechanism control unit 17 and forms an image on a sheet according to the print data received via the communication I / F unit 13.

  FIG. 2 is a configuration diagram of a printer according to an embodiment of the present invention.

  In the housing 2 of the printer 1, a photoconductor unit 22, an exposure unit 23, a development unit 24, a transfer unit 25, a fixing unit 26, a transport unit 27, a paper sensor 28, and the like are provided. The photoconductor unit 22 includes a photoconductor 22a. The photoreceptor 22a is rotatable in the clockwise direction in the drawing. Around the photoconductor 22a, a charging roller (not shown) of the photoconductor unit 22, a developing unit 24, an intermediate transfer belt 25a of the transfer unit 25, and a cleaning unit (not shown) of the photoconductor unit 22 are arranged in this order along the clockwise direction. ing. The developing unit 24 has a plurality of developing units that accommodate respective toners of yellow (Y), cyan (C), magenta (M), and black (K). The developing unit 24 is rotatable in the counterclockwise direction in the drawing, and any developing device can come into contact with the photosensitive member 22a by rotating.

  In the photoconductor unit 22, the photoconductor 22a is charged by a charging roller while rotating. Thereafter, the photosensitive member 22 a is irradiated with laser light from the exposure unit 23 controlled by the mechanism control unit 17. As a result, an electrostatic latent image for the image included in the print data is formed on the photoreceptor 22a. Next, any one developing device of the developing unit 24 is selectively brought into contact with the photosensitive member 22a by the mechanism control unit 17, and the electrostatic latent image is developed to form a toner image. The toner image formed on the photoreceptor 22a is transferred onto the intermediate transfer belt 25a.

  In the case of color image printing, by forming the electrostatic latent image and developing the electrostatic latent image for each color of yellow, cyan, magenta, and black, a toner image of each color is formed, and intermediate transfer is performed. A color toner image is formed by superimposing these color toner images on the belt 25a. On the other hand, in the case of monochrome image printing, a monochrome toner image is formed and transferred onto the transfer belt 25a by performing the above-described electrostatic latent image formation and electrostatic latent image development for only black.

  In the transfer unit 25, the transfer belt 25a is stretched around a plurality of rollers. Further, the transfer unit 25 includes a transfer roller 25 b for transferring the toner image formed on the transfer belt 25 a to a sheet fed by the transport unit 27.

  The transport unit 27 includes a paper cassette 30 as an example of a first placement unit for placing paper on which an image is to be formed, a manual feed tray (MP tray) 31 for placing paper on which an image is to be formed, and a second. It has a paper discharge tray 32 as an example of the placing means. The transport unit 27 includes a first transport unit 40, a second transport unit 37, a third transport unit 33, and a fourth transport unit 43 as an example of a partial transport unit. The unit is configured to share the conveyance of the paper in the conveyance path. Here, the first transport unit 40, the second transport unit 37, the third transport unit 33, and the fourth transport unit 43 share the transport areas, which are the first region, the second region, the third region, and the fourth region, respectively. That is to say. In this embodiment, the 1st conveyance part 40, the 2nd conveyance part 37, the 3rd conveyance part 33, and the 4th conveyance part 43 each convey a paper with the motive power of a different motor. Therefore, the conveyance control unit 10b can control each conveyance unit independently. For example, only a part of the conveyance units can convey the sheet, or conveyance of the sheet by each conveyance unit. The direction can be freely controlled.

  The first transport unit 40 includes a branch roller 41 and a paper discharge roller 42. The second transport unit 37 includes a roller 38 and a fixing roller 26a. The third transport unit 33 includes a paper feed roller 34, a paper feed roller 35, and a paper feed roller 36. The fourth transport unit 43 includes a double-sided roller 44.

  In the case of single-sided printing, the transport unit 27 moves the paper in the paper cassette 30 from point A → B point → C point → D point → E point → When an image is formed on a sheet placed on the manual feed tray 31 by conveying along the conveyance path indicated by point F, the paper on the manual feed tray 31 is point I → B point → C point → D point → E point → F point. It is conveyed by the conveyance route shown in In addition, in the case of duplex printing, the transport unit 25, when forming an image on the paper placed on the paper cassette 30, moves the paper in the paper cassette 30 from point A → B point → C point → D point → When F point is transported and switched back, transported along the transport path indicated by G point → H point → C point → D point → E point → F point to form an image on the paper placed on the manual feed tray 31 In this case, the paper in the manual feed tray 31 is transported from point I → B point → C point → D point → E point, and is switched back, G point → H point → C point → D point → E point → F point. It is conveyed by the conveyance route shown in Here, the route from point A → B point → C point → D point → E point → F point is referred to as a main route, and the route through which the switched-back paper is conveyed, ie, E point → G point → H point → The route returning from the main route up to point C back to the main route is called the reverse route.

  The paper sensor 28 includes a pre-feed sensor 28a disposed upstream of the paper feed roller 36, a pre-gate sensor 28b disposed upstream of the roller 38, and a post-transfer sensor disposed downstream of the transfer roller 25b. 28c, a post-fixing sensor 28d disposed on the downstream side of the fixing roller 26, and a pre-discharge sensor 28e disposed on the upstream side of the discharge roller 42. Each of the sensors 28a to 28e has a light emitting unit that emits light and a light receiving unit that receives the light, and generates a signal according to the intensity of the light received by the light receiving unit. It arrange | positions so that light may be emitted and the reflected light from the conveyance path | route side may be received in a light-receiving part. Therefore, based on the magnitude of the signal generated by each of the sensors 28a to 28e, it can be determined whether or not a sheet exists at a point on the conveyance path to which the sensor is directed. Here, in each of the sensors 28a to 28e, a signal indicating that a sheet is present is output. This means that the sensor is in an ON state (on), and a signal indicating that a sheet is not present is output. That the sensor is in the OFF state.

  In the printer 1, when an image is formed on a sheet, the sheet is conveyed to the transfer roller 25b by the conveyance unit 27, and the toner image on the transfer belt 25a is transferred by the transfer roller 25b. At this time, the sheet is detected by a sensor (not shown), and based on this detection, the mechanism control unit 17 transfers the toner image to a predetermined position on the sheet. The sheet on which the toner image has been transferred is further conveyed to the fixing unit 26 at the subsequent stage. For example, the fixing unit 26 applies heat and pressure to the sheet on which the toner image is transferred, and fixes the toner image on the sheet. The sheet on which the toner image is fixed is transported by the transport unit 27 to the paper discharge tray 32 in the case of single-sided printing, and is switched back by the reverse roller 41 in the case of double-sided printing. The image is formed on the back surface.

  FIG. 3 is a flowchart of jam-related processing according to an embodiment of the present invention.

  This jam-related process is executed in parallel with the image forming process for forming an image on a sheet in a normal state where no jam has occurred.

  First, the jam detection unit 10a detects whether or not a jam has occurred based on the detection state of the paper by the pre-discharge sensor 28e (step S1). From the state by the pre-discharge sensor 28e, it is detected whether any of unreached jam, stay jam, or residual jam has occurred. Here, the unreached jam can be detected by the fact that the sensor is not turned ON even if a predetermined time elapses from a predetermined time point. Further, the stay jam can be detected by the fact that the sensor does not change from the ON state to the OFF state even if a predetermined time elapses from a predetermined time point. Residual jams can be detected when the sensor is in an ON state when the power is turned on, when the cover is closed, or when returning from the energy save mode.

  Next, the jam detection unit 10a determines whether or not a jam has occurred (step S2). If it is determined that no jam has occurred, the post-fixing sensor 28d detects the sheet. Based on the state, it is detected whether a jam has occurred (step S3). From the state by the post-fixing sensor 28d, it is detected whether an unreached jam, a stagnant jam, or a residual jam has occurred.

  Next, the jam detection unit 10a determines whether or not a jam has occurred (step S4).

  When it is determined that a jam has occurred based on the state of the pre-discharge sensor 28e or the state of the post-fixing sensor 28d (YES in step S2 or YES in step S4), the first Since this means that a jam has been detected in the area, the first area jam handling process (step S5) shown in FIG. 4 is executed, and the process returns to step S1.

  On the other hand, when it is determined that a jam has not occurred (NO in step S4), the jam detection unit 10a detects whether a jam has occurred based on the detection state of the paper by the post-transfer sensor 28c ( Step S6). From the state of the post-transfer sensor 28c, it is detected whether an unreached jam, a stay jam, or a residual jam has occurred.

  Next, it is determined whether or not the occurrence of a jam has been detected (step S7). If it is determined that no jam has occurred, the jam detection unit 10a detects the sheet by the pre-gate sensor 28b. Based on the state, it is detected whether a jam has occurred (step S8). From the state by the pre-gate sensor 28b, it is detected whether an unreached jam, a stay jam, or a residual jam has occurred.

  Next, the jam detection unit 10a determines whether or not a jam has occurred (step S9). When it is determined that a jam has occurred based on the state of the post-transfer sensor 28c or the state of the pre-gate sensor 28b (YES in step S7 or YES in step S9), the second Since this means that a jam has been detected in the area, the second area jam handling process (step S10) shown in FIG. 5 is executed, and the process returns to step S1.

  On the other hand, when it is determined that a jam has not occurred (NO in step S9), the jam detection unit 10a detects whether a jam has occurred based on the detection state of the paper by the pre-feed sensor 28a ( Step S11). From the state of the pre-feed sensor 28a, it is detected whether any of unreached jam, stay jam, residual jam, or paper feed failure has occurred. Here, the paper feed failure state can be detected by the fact that the pre-feed sensor 28a does not become ON even after a predetermined time has elapsed since the paper feed operation was started.

  Next, the jam detection unit 10a determines whether or not a jam has occurred (step S12). If it is determined that a jam has not occurred, the process returns to step S1, while the jam is detected. If it is determined that the occurrence has been detected, it means that a jam has been detected in the third area. Therefore, the third area jam handling process (step S13) shown in FIG. 6 is executed, and step S1 is executed. Return to.

  FIG. 4 is a flowchart of the first area jam handling process according to an embodiment of the present invention.

  In the first area jam handling process (step S5), first, the transport control unit 10b determines whether or not the pre-discharge sensor 28e is in an ON state (step S21), and when it is not in an ON state (NO in step S21). Further, it is determined whether or not the post-fixing sensor 28d is in an ON state (step S22).

  As a result, when the post-fixing sensor 28d is not in the ON state (NO in step S22), it means that the detection position of the post-fixing sensor 28d has not been reached. The conveyance unit 27 shown in FIG. That is, the conveyance control unit 10b is in the first area by rotating the rollers (the branch roller 41 and the paper discharge roller 42) in the first area normally (rotation direction when conveying the sheet from upstream to downstream). The paper is discharged to the paper discharge tray 32. Further, the conveyance control unit 10b reversely rotates the rollers (roller 38 and fixing roller 26a) in the second area (rotation when conveying the paper from the downstream to the upstream) to remove the paper in the second area to the outside. To a position where it can be easily removed. Further, the conveyance control unit 10b reversely rotates the rollers (the paper feed roller 34, the paper feed roller 35, and the paper feed roller 36) in the third area, and conveys the paper in the third area to the paper cassette 30. . In addition, the conveyance control unit 10b rotates the rollers (double-sided rollers 44) in the fourth region in the reverse direction (rotation when conveying the paper from downstream to upstream (from the G point to the F point)), thereby The paper in the area is discharged to the paper discharge tray 32 through the first area.

  By such processing, the paper in the first area, the third area, or the fourth area is appropriately discharged to the paper discharge tray 32 or the paper cassette 30. In order to eliminate the jam, There is no need to remove these sheets. Further, the paper discharged to the paper cassette 30 can be used for image formation thereafter. In addition, since the paper in the second area is transported to a position where it can be easily removed from the outside, the paper can be easily removed.

  On the other hand, when the post-fixing sensor 28d is in the ON state (YES in step S22), it is a jam that has not reached the detection position of the pre-discharge sensor 28e or a staying jam at the detection position of the post-fixing sensor 28d. This means that the transport control unit 10b controls the transport unit 27 shown below (step S24). That is, the conveyance control unit 10b stops the rollers 41 and 42 in the first area. Further, the conveyance control unit 10b rotates the rollers 38 and 26a in the second area in the reverse direction to convey the paper in the second area to a position where it can be easily taken from the outside. Further, the conveyance control unit 10b rotates the rollers 34, 35, and 36 in the third area in the reverse direction, and conveys the paper in the third area to the paper cassette 30. Further, the conveyance control unit 10b reversely rotates the roller 44 in the fourth area, and conveys the paper in the fourth area to a position where it can be easily taken from the outside.

  As a result of such processing, the sheets in the third area are appropriately discharged to the sheet cassette 30. Therefore, it is not necessary to remove these sheets in order to eliminate the jam. Further, since the paper in the second area or the fourth area is transported to a position where it can be easily removed from the outside, the paper can be easily removed.

  On the other hand, if the pre-discharge sensor 28e is in the ON state (YES in step S21), it is further determined whether or not the post-fixing sensor 28d is in the ON state (step S25).

  As a result, if the post-fixing sensor 28d is not in the ON state (NO in step S25), it means that the jammed jam is detected at the detection position of the pre-discharge sensor 28e. Is controlled (step S26). That is, the conveyance control unit 10b attempts to discharge the paper in the first area to the paper discharge tray 32 by rotating the rollers 41 and 42 in the first area normally for a certain period of time. Further, the conveyance control unit 10b rotates the rollers 38 and 26a in the second area in the reverse direction to convey the paper in the second area to a position where it can be easily taken from the outside. Further, the conveyance control unit 10b rotates the rollers 34, 35, and 36 in the third area in the reverse direction, and conveys the paper in the third area to the paper cassette 30. Further, the conveyance control unit 10b reversely rotates the roller 44 in the fourth area, and conveys the paper in the fourth area to a position where it can be easily taken from the outside.

  As a result of such processing, the sheets in the third region are appropriately discharged to the sheet cassette 30. Therefore, it is not necessary to remove these sheets in order to eliminate the jam. Further, since the paper in the second area or the fourth area is transported to a position where it can be easily removed from the outside, the paper can be easily removed. In addition, since the paper in the first area is tried to be discharged to the paper discharge tray 32, it can be expected that the user does not need to remove the paper from the inside.

  On the other hand, when the post-fixing sensor 28d is in the ON state (YES in step S25), it is a staying jam at the detection position of the pre-discharge sensor 28e and a staying jam at the detection position of the post-fixing sensor 28d. This means that the transport control unit 10b controls the transport unit 27 shown below (step S27). That is, the conveyance control unit 10b attempts to discharge the paper in the first area to the paper discharge tray 32 by rotating the rollers 41 and 42 in the first area normally for a certain period of time. Further, the conveyance control unit 10b rotates the rollers 38 and 26a in the second area in the reverse direction to convey the paper in the second area to a position where it can be easily taken from the outside. Further, the conveyance control unit 10b rotates the rollers 34, 35, and 36 in the third area in the reverse direction, and conveys the paper in the third area to the paper cassette 30. Further, the conveyance control unit 10b reversely rotates the roller 44 in the fourth area, and conveys the paper in the fourth area to a position where it can be easily taken from the outside.

  As a result of such processing, the sheets in the third region are appropriately discharged to the sheet cassette 30. Therefore, it is not necessary to remove these sheets in order to eliminate the jam. Further, since the paper in the second area or the fourth area is transported to a position where it can be easily removed from the outside, the paper can be easily removed. In addition, since the paper in the first area is tried to be discharged to the paper discharge tray 32, it can be expected that the user does not need to remove the paper from the inside.

  Next, after executing step S23, S24, S26, or S27 described above, jam error processing is executed (step S28). In the jam error processing, the conveyance control unit 10b turns off the clutch of the conveyance unit 27, turns off all the motors of the conveyance unit 27, and the image formation control unit 10c controls the operation stop of each unit of the image forming unit 21. When the transfer roller 38 is in contact with the sheet, the transfer roller 38 is controlled to be separated from the sheet.

  Next, the image formation control unit 10c detects whether or not a return instruction, for example, a cover (not shown) of the housing 2 that is opened when the paper is removed is closed by a user operation (step S29). If there is no return instruction, the step is repeatedly executed. If there is a return instruction, execution of the image forming process is resumed, and the process returns to step S1 shown in FIG.

  FIG. 5 is a flowchart of the second area jam handling process according to an embodiment of the present invention.

  In the second area jam handling process (step S10), first, the transport control unit 10b determines whether or not the post-transfer sensor 28c is in an ON state (step S31), and if not (ON in step S31). Further, it is determined whether or not the pre-gate sensor 28b is in an ON state (step S32).

  As a result, when the pre-gate sensor 28b is not in the ON state (NO in step S32), it means that the jam has not reached the detection location of the pre-gate sensor 28b. Is controlled (step S33). In other words, the conveyance control unit 10 b normally rotates the rollers 41 and 42 in the first area, and discharges the paper in the first area to the paper discharge tray 32. Further, the transport control unit 10b normally rotates the rollers 38 and 26a in the second area (rotation when transporting the paper from the upstream to the downstream), and causes the paper in the second area to pass through the first area. Paper is discharged to the paper discharge tray 32. Further, the conveyance control unit 10b rotates the rollers 34, 35, and 36 in the third area in the reverse direction, and conveys the paper in the third area to the paper cassette 30. Further, the conveyance control unit 10b rotates the roller 44 in the fourth area in the reverse direction, and discharges the paper in the fourth area to the paper discharge tray 32 through the first area.

  By such processing, the sheets in the first area, the second area, or the fourth area are appropriately discharged to the discharge tray 32, and therefore these sheets are removed to eliminate the jam. No work is necessary. Further, since the paper in the third region is being tried to be transported to the paper cassette 30, it can be expected that the user need not remove the paper from the inside.

  On the other hand, when the pre-gate sensor 28b is in the ON state (YES in step S32), it is a jam that has not reached the detection position of the post-transfer sensor 28c or a stay jam at the detection position of the pre-gate sensor 28b. This means that the transport control unit 10b controls the transport unit 27 shown below (step S34). In other words, the conveyance control unit 10 b normally rotates the rollers 41 and 42 in the first area, and discharges the paper in the first area to the paper discharge tray 32. Further, the conveyance control unit 10b normally rotates the rollers 38 and 26a in the second area, and conveys the paper in the second area to a position where it can be easily taken from the outside. Further, the conveyance control unit 10b waits for a predetermined period of time to rotate the rollers 34, 35, and 36 in the third region for a predetermined time, and then reversely rotates the rollers in the third region to transfer the paper in the third region to the paper cassette. 30. Further, the conveyance control unit 10b rotates the roller 44 in the fourth area in the reverse direction, and discharges the paper in the fourth area to the paper discharge tray 32 through the first area.

  As a result of such processing, the paper in the first area or the fourth area is appropriately discharged to the paper discharge tray 32 or the paper cassette 30. Therefore, in order to eliminate jamming, the operation of removing these papers is performed. Is not necessary. Further, since the paper in the second region is transported to a position where it can be easily removed from the outside, the paper can be easily removed. In addition, when the paper in the second area is transported, the paper remaining in the third area is transported to the paper cassette 30. Therefore, in order to eliminate the jam, the work of removing these papers is not necessary. unnecessary.

  On the other hand, if the post-transfer sensor 28c is in the ON state (YES in step S31), it is further determined whether or not the pre-gate sensor 28b is in the ON state (step S35).

  As a result, when the pre-gate sensor 28b is not in the ON state (NO in step S35), it means that the jam is staying at the detection position of the post-transfer sensor 28c. Is controlled (step S36). In other words, the conveyance control unit 10 b normally rotates the rollers 41 and 42 in the first area, and discharges the paper in the first area to the paper discharge tray 32. Further, the conveyance control unit 10b rotates the rollers 38 and 26a in the second area in the reverse direction to convey the paper in the second area to a position where it can be easily taken from the outside. Further, the conveyance control unit 10b rotates the rollers 34, 35, and 36 in the third area in the reverse direction, and conveys the paper in the third area to the paper cassette 30. Further, the conveyance control unit 10b rotates the roller 44 in the fourth area in the reverse direction, and discharges the paper in the fourth area to the paper discharge tray 32 through the first area.

  By such processing, the paper in the first area, the third area, or the fourth area is appropriately discharged to the paper discharge tray 32 or the paper cassette 30. In order to eliminate the jam, There is no need to remove these sheets. Further, since the paper in the second region is transported to a position where it can be easily removed from the outside, the paper can be easily removed.

  On the other hand, when the pre-gate sensor 28b is in the ON state (YES in step S35), it is a stay jam at the detection location of the post-transfer sensor 28c and a stay jam at the detection location of the pre-gate sensor 28b. This means that the transport control unit 10b controls the transport unit 27 shown below (step S37). In other words, the conveyance control unit 10 b normally rotates the rollers 41 and 42 in the first area, and discharges the paper in the first area to the paper discharge tray 32. Further, the conveyance control unit 10b rotates the rollers 38 and 26a in the second area in the reverse direction to convey the paper in the second area to a position where it can be easily taken from the outside. Further, the conveyance control unit 10b rotates the rollers 34, 35, and 36 in the third area in the reverse direction, and conveys the paper in the third area to the paper cassette 30. Further, the conveyance control unit 10b rotates the roller 44 in the fourth area in the reverse direction, and discharges the paper in the fourth area to the paper discharge tray 32 through the first area.

  By such processing, the paper in the first area, the third area, or the fourth area is appropriately discharged to the paper discharge tray 32 or the paper cassette 30. In order to eliminate the jam, There is no need to remove these sheets. Further, since the paper in the second region is transported to a position where it can be easily removed from the outside, the paper can be easily removed.

  Next, after executing step S33, S34, S36, or S37 described above, jam error processing is executed (step S38). In this jam error process, the conveyance control unit 10b turns off the clutch of the conveyance unit 27 and turns off all the motors of the conveyance unit 27. Further, the image forming control unit 10c controls the operation stop of each unit of the image forming unit 21, and when the transfer roller 38 is in contact with the sheet, the transfer roller 38 is controlled to be separated from the sheet. To do.

  Next, the image forming control unit 10c detects a return instruction by the user's operation, for example, whether or not the cover of the housing 2 that is opened when the paper is removed is closed (step S39). On the other hand, if this step is repeatedly executed and there is a return instruction, the execution of the image forming process is resumed, and the process returns to step S1 shown in FIG.

  FIG. 6 is a flowchart of third area jam handling processing according to an embodiment of the present invention.

  In the third area jam handling process (step S13), first, the conveyance control unit 10b determines whether or not the pre-feed sensor 28a is in an ON state (step S41), and if it is not in an ON state (NO in step S41). This means that there is a paper feed failure or a jam that has not reached the detection position of the pre-feed sensor 28a, so the transport control unit 10b controls the transport unit 27 shown below (step S42). . In other words, the conveyance control unit 10 b normally rotates the rollers 41 and 42 in the first area, and discharges the paper in the first area to the paper discharge tray 32. Further, the conveyance control unit 10b normally rotates the rollers 38 and 26a in the second area, and discharges the paper in the second area to the paper discharge tray 32 through the first area. At the same time, the image formation control unit 10c operates the fixing unit 26 to fix the toner image on the paper conveyed from the second area to the paper discharge tray 32. Further, the conveyance control unit 10b rotates the rollers 34, 35, and 36 in the third area in the reverse direction, and conveys the paper in the third area to the paper cassette 30. Further, the conveyance control unit 10b rotates the roller 44 in the fourth area in the reverse direction, and discharges the paper in the fourth area to the paper discharge tray 32 through the first area.

  By such processing, the paper in the first area, the second area, the third area, or the fourth area is appropriately discharged to the paper discharge tray 32 or the paper cassette 30. There is no need to remove these sheets to eliminate the problem. In addition, since the paper in the second area is discharged after being subjected to a fixing process, the paper and the user can be prevented from being stained by the paper.

  On the other hand, if the pre-feed sensor 28a is in the ON state (YES in step S41), it is further determined whether or not the pre-gate sensor 28b is in the ON state (step S43).

  As a result, when the pre-gate sensor 28b is not in the ON state (NO in step S43), it means that the jam is at the detection position of the pre-feed sensor 28a. Is controlled (step S44). In other words, the conveyance control unit 10 b normally rotates the rollers 41 and 42 in the first area, and discharges the paper in the first area to the paper discharge tray 32. Further, the conveyance control unit 10b normally rotates the rollers 38 and 26a in the second area, and discharges the paper in the second area to the paper discharge tray 32 through the first area. At the same time, the image formation control unit 10c operates the fixing unit 26 to fix the toner image on the paper conveyed from the second area to the paper discharge tray 32. Further, the conveyance control unit 10b rotates the rollers 34, 35, and 36 in the third area in the reverse direction, and conveys the paper in the third area to the paper cassette 30. Further, the conveyance control unit 10b rotates the roller 44 in the fourth area in the reverse direction, and discharges the paper in the fourth area to the paper discharge tray 32 through the first area.

  By such processing, the paper in the first area, the second area, or the fourth area is appropriately discharged to the paper discharge tray 32 or the paper cassette 30. In order to eliminate the jam, There is no need to remove these sheets. Further, since the paper in the second area is discharged after being subjected to fixing processing, it is possible to prevent the inside of the apparatus and the user from being stained by the paper. In addition, since the paper in the third region is tried to be transported to the paper cassette 30, it can be expected that the user does not need to remove the paper from the inside.

  On the other hand, when the pre-gate sensor 28b is in the ON state (YES in step S43), it means that the jam is at the detection position of the pre-feed sensor 28a. Is controlled (step S45). In other words, the conveyance control unit 10 b normally rotates the rollers 41 and 42 in the first area, and discharges the paper in the first area to the paper discharge tray 32. Further, the transport control unit 10b tries to transport the paper in the second region to the paper cassette 31 through the third region by rotating the rollers 38 and 26a in the second region in the reverse direction. Further, the conveyance control unit 10b tries to convey the paper in the third area to the paper cassette 30 by rotating the rollers 34, 35, and 36 in the third area in the reverse direction. Further, the conveyance control unit 10b rotates the roller 44 in the fourth area in the reverse direction, and discharges the paper in the fourth area to the paper discharge tray 32 through the first area.

  By such processing, the sheets in the first area or the fourth area are appropriately discharged to the sheet discharge tray 32, so that it is not necessary to remove these sheets in order to eliminate the jam. In addition, since the paper in the second area or the third area is tried to be transported to the paper cassette 30, it can be expected that the user does not need to remove the paper from the inside.

  Next, after executing step S42, S44 or S45 described above, jam error processing is executed (step S46). In this jam error process, the conveyance control unit 10b turns off the clutch of the conveyance unit 27 and turns off all the motors of the conveyance unit 27. Further, the image forming control unit 10c controls the operation stop of each unit of the image forming unit 21, and when the transfer roller 38 is in contact with the paper, the transfer roller 38 is separated from the paper. To control.

  Next, the image formation control unit 10c detects a return instruction by the user's operation, for example, whether or not the cover of the housing 2 that is opened when the paper is removed is closed (step S47). On the other hand, if this step is repeatedly executed and there is a return instruction, the execution of the image forming process is resumed, and the process returns to step S1 shown in FIG.

  Although the present invention has been described based on the embodiments, the present invention is not limited to the above-described embodiments, and can be applied to various other modes.

  For example, in the above embodiment, a reflection type optical sensor is used as a sensor for detecting paper, but the present invention is not limited to this. For example, a transmission type optical sensor may be used. The sensor is not limited to a photo sensor, and may be another mechanical sensor. In short, any sensor that can detect the presence or absence of paper is acceptable.

  In the above-described embodiment, each transport unit that handles a part of the transport path is driven by a separate motor so that paper can be transported independently. However, the present invention is not limited to this. For example, a plurality of conveyance units are driven by the same motor, and a power transmission path from the motor to each conveyance unit is provided with a clutch, a gear, etc., and these clutches, gears, etc. are controlled independently. Paper conveyance may be performed.

  In the above embodiment, the present invention is applied to a printer. However, the present invention is not limited to this. For example, the present invention can also be applied to other image forming apparatuses such as a copying machine and a FAX apparatus. .

FIG. 2 is a functional configuration diagram of a printer according to an embodiment of the present invention. 1 is a configuration diagram of a printer according to an embodiment of the present invention. FIG. It is a flowchart of the jam related process which concerns on one Embodiment of this invention. It is a flowchart of the 1st area jam handling processing concerning one embodiment of the present invention. It is a flowchart of the 2nd field jam handling processing concerning one embodiment of the present invention. It is a flowchart of the 3rd field jam handling processing concerning one embodiment of the present invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 Printer, 2 housing | casing, 10 CPU, 10a Jam detection part, 10b Conveyance control part, 10c Image formation control part, 11 Input I / F part, 12 Display processing part, 13 Communication I / F part, 14 ROM, 15 RAM , 16 EEPROM, 17 mechanism control unit, 18 bus, 19 key unit, 20 LCD, 21 image forming unit, 22 photoconductor unit, 23 exposure unit, 24 developing unit, 25 transfer unit, 26 fixing unit, 27 transport unit, 28 Paper sensor.

Claims (9)

A first placing means for placing an image forming medium for forming an image;
A second placing means for placing an image forming medium on which an image is formed;
Conveying means for conveying the image forming medium along a conveying path from the first placing means to the second placing means;
Jam detecting means for detecting the occurrence of jam of the image forming medium at a plurality of points in the transport path;
When occurrence of the jam at any one of the plurality of points is detected, the image forming medium existing in the conveyance path other than the point is set to a predetermined position determined according to the point. An image forming apparatus comprising: a conveyance control unit that is conveyed by the conveyance unit. 2. The transport control unit according to claim 1, wherein the transport control unit stops the operation of the transport unit after transporting an image forming medium existing outside the point where the occurrence of the jam is detected to the predetermined position. The image forming apparatus described. The predetermined position is a position of the first mounting unit, a position of the second mounting unit, or a position where the image forming medium in the transport path can be easily removed. The image forming apparatus according to claim 1 or 2. The conveyance control unit causes the second mounting unit to convey an image forming medium existing downstream of the conveyance path from the point where occurrence of a jam is detected by the conveyance unit. The image forming apparatus according to claim 1. The transport means is in charge of transporting the image forming medium in each part of the transport path, and has a plurality of partial transport means capable of transporting independently of other parts,
The conveyance control unit operates one or a plurality of the partial conveyance units in charge of a portion downstream of the conveyance path from the point where the occurrence of the jam is detected, and removes the image forming medium existing in the portion. The image forming apparatus according to claim 4, wherein the image forming apparatus is transported to a second mounting unit. A transfer unit provided facing the conveyance path and transferring a toner image to the image forming medium;
A fixing unit provided facing the conveyance path and fixing the toner image transferred to the image forming medium;
If the occurrence of the jam at a point upstream of the fixing unit is detected by the jam detecting unit, after the image forming medium is transported through the fixing unit, the fixing unit The image forming apparatus according to claim 4, further comprising a fixing control unit that stops the operation. 2. The conveyance control unit according to claim 1, wherein the conveyance unit causes the first placement unit to convey an image forming medium existing upstream from the point where occurrence of a jam is detected. The image forming apparatus according to claim 6. The transport means is in charge of transporting the image forming medium in each part of the transport path, and has a plurality of partial transport means capable of transporting independently of other parts,
The conveyance control unit operates one or a plurality of partial conveyance units in charge of a portion upstream of the conveyance path from the point where the occurrence of a jam is detected, and the image forming medium existing in the portion is The image forming apparatus according to claim 7, wherein the image forming apparatus is conveyed to a first mounting unit. A first placing unit for placing an image forming medium for forming an image; a second placing unit for placing an image forming medium on which an image is formed; and the second placing unit through the first placing unit. An image forming medium conveyance control method in an image forming apparatus, comprising: a conveying unit that conveys the image forming medium along a conveyance path to the placing unit;
A jam detection step of detecting occurrence of jam of the image forming medium at a plurality of points in the transport path;
When occurrence of the jam at any one of the plurality of points is detected, the image forming medium existing in the conveyance path other than the point is set to a predetermined position determined according to the point. A transport control method comprising transport control steps of transport by the transport means.

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