JP2007017893A - Image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent soiling of component parts by an unfixed image even when forward sheet supplying is carried out. <P>SOLUTION: The forward sheet supplying is interrupted when the forward sheet supplying amount measured by a rotary encoder 33 exceeds a stipulated amount. Thus, the forward sheet supplying is interrupted immediately before the unfixed image on continuous sheet P is passed over a flash fixing apparatus 21 and the continuous sheet P is stopped in that position. Therefore, even when the forward sheet supplying is carried out, the component parts (especially a drive roller 32 or a pinch roller 34) installed on a downstream side of the fixing part are not soiled by the unfixed image. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an image forming apparatus that forms an image on continuous paper.

  As an image forming apparatus that forms an image on a continuous sheet, an image forming apparatus that sandwiches and conveys a continuous sheet having no feed hole between a drive roller and a pinch roller (so-called pinless conveyance) is known (for example, Patent Document 1). ).

  As an image forming apparatus that performs pinless conveyance, an image forming apparatus that has a forward paper feeding function that is used for removing continuous paper jammed in the conveyance path, and for aligning a transfer position for transferring an image to continuous paper, etc. Proposed.

  This advance paper feed is started, for example, when the operator presses a dedicated switch. When the advance paper feed is started, the continuous paper is transported and discharged out of the apparatus without fixing the transferred image.

  For this reason, an image that has not been fixed after being transferred onto a continuous sheet passes through the transport path in an unfixed state and is discharged.

In an image forming apparatus that performs pinless conveyance, a continuous sheet is sandwiched between the drive roller and the pinch roller with a strong pinch pressure. An image is sandwiched between a drive roller and a pinch roller. For this reason, the toner of the unfixed image is transferred to the drive roller and the pinch roller, and the drive roller and the pinch roller are soiled.
JP 2005-169783 A

  In consideration of the above-described facts, an object of the present invention is to prevent components from being stained with an unfixed image even when forward paper feeding is performed.

  An image forming apparatus according to claim 1 of the present invention includes a conveying unit that conveys continuous paper, a fixing unit that fixes an image transferred to the continuous paper, and a fixing operation of the fixing unit being stopped. Control means for feeding forward paper by causing the transport means to feed continuous paper; and measuring means for measuring the transport amount of the continuous paper fed forward by the control means, the control means comprising: The forward paper feed is interrupted when the transport amount of the continuous paper having an unfixed image measured by the measuring unit exceeds a predetermined amount.

  In this configuration, the transport unit transports the continuous paper, and the fixing unit fixes the image transferred onto the continuous paper.

  The control unit feeds the forward paper by causing the transport unit to transport the continuous sheet in a state where the fixing operation of the fixing unit is stopped. The measuring unit measures the transport amount of the continuous sheet fed forward by the control unit.

  Further, the control means interrupts the forward paper feed when the transport amount of the continuous paper having the unfixed image measured by the measurement means exceeds a specified amount.

  For this reason, even if forward paper feed is performed by setting a prescribed amount so that forward paper feed of continuous paper with an unfixed image is interrupted before the component parts, the component parts are unfixed images. It will not get dirty.

  An image forming apparatus according to a second aspect of the present invention is the image forming apparatus according to the first aspect, wherein the forward paper feed is interrupted before the unfixed image on the continuous paper finishes passing through the fixing unit. A specified amount is set.

  In this configuration, the specified amount is set such that the unfixed image on the continuous sheet is interrupted in advance paper feed before it has passed through the fixing unit.

  For this reason, even if the forward paper feed is performed, the components arranged on the downstream side of the fixing unit are not stained with the unfixed image.

  An image forming apparatus according to a third aspect of the present invention is the image forming apparatus according to the second aspect, wherein the control unit warns the operator to execute the fixing operation of the fixing unit after interrupting the advance paper feeding. Means are provided.

  In this configuration, after the control unit interrupts the advance paper feeding, the warning unit warns the operator to execute the fixing operation of the fixing unit.

  With this warning, if the operator performs the fixing operation of the fixing unit, the unfixed image on the continuous paper that has been stopped before passing through the fixing unit is fixed. If the unfixed image is fixed, the unfixed image disappears, and even if the continuous paper is conveyed, the component parts are not stained with the unfixed image.

  According to a fourth aspect of the present invention, there is provided an image forming apparatus according to any one of the first to third aspects, further comprising setting means capable of setting whether or not to execute the forward paper feed interruption operation of the control means. It is characterized by that.

  In this configuration, it is possible to set whether or not to execute the forward paper feed interruption operation of the control means. As a result, when priority is given to the forward paper feeding operation of the control means, the interruption operation of the control means can be prevented from being executed.

  Since the present invention has the above-described configuration, it is possible to prevent the component parts from being smudged with the unfixed image even when the forward paper feeding is performed.

  Hereinafter, an exemplary embodiment according to an image forming apparatus of the present invention will be described with reference to the drawings.

  As shown in FIG. 1, the image forming apparatus 10 according to the present embodiment includes a drive roller 32 and a pinch roller 34 as conveying means for nipping and conveying a continuous sheet P without a feed hole in the arrow F direction.

  The drive roller 32 is configured to rotate by a drive roller motor 12 connected to the drive roller 32. The drive roller motor 12 is connected to a control unit (control unit) 16 that controls the conveyance amount of the continuous paper P conveyed by the drive roller 32 by controlling the rotation speed of the drive roller 32.

  The drive roller 32 is attached with a rotary encoder 33 that measures the conveyance amount of the drive roller 32 by measuring the rotation speed of the drive roller 32. The rotary encoder 33 is connected to the control unit 16, and information on the conveyance amount of the drive roller 32 measured by the rotary encoder 33 is input to the control unit 16.

  The pinch roller 34 is provided at an opposing position above the drive roller 32, and is configured to pinch (pinch) the continuous paper P with the drive roller 32. The pinch roller 34 is driven and rotated at the same peripheral speed as the drive roller 32, and the pinch pressure is adjusted so that the pinched continuous paper P does not slip between the drive roller 32 and the pinch roller 34. .

  The continuous paper P is sandwiched between the drive roller 32 and the pinch roller 34 and the drive roller 32 rotates, whereby the continuous paper P is nipped and conveyed in the paper conveyance direction F.

  An image forming unit 15 that forms a toner image based on the image data and transfers the toner image to the continuous paper P is provided upstream of the drive roller 32 in the paper conveyance direction.

  The image forming unit 15 includes a photosensitive drum (image carrier) 20 that rotates in the direction of arrow A. Around the photosensitive drum 20, in order from the upstream side in the rotation direction of the photosensitive drum 20, a charging corotron 24 that charges the surface of the photosensitive drum 20 and the photosensitive drum 20 are exposed to the photosensitive drum 20. An LED exposure optical system (exposure means) 26 that forms a latent image, a developing unit 28 that develops the toner by attaching the toner to the latent image formed on the photoconductor drum 20 by the LED exposure optical system 26, and the photoconductor drum 20. A transfer corotron (image transfer means) 22 for transferring the toner image formed on the toner image to the continuous paper P by the image transfer unit T, a static elimination corotron 27 for eliminating the surface of the photosensitive drum 20, and a photoreceptor removed by the static elimination corotron 27. A cleaner 29 for removing toner from the surface of the drum 20 is provided.

  A flash fixing device (fixing unit) 21 that fixes the transferred toner image onto the continuous paper P is provided downstream of the image transfer unit T in the paper transport direction and upstream of the drive roller 32 in the paper transport direction. Yes. Between the image transfer portion T and the flash fixing device 21, a guide roller group 52 that guides the continuous paper P that has passed through the image transfer portion T to the flash fixing device 21 is provided.

  Between the flash fixing device 21 and the drive roller 32, a guide roller group 54 for guiding the continuous paper P that has passed through the flash fixing device 21 to the drive roller 32 is provided.

  A side guide unit 14 is provided on the upstream side of the image transfer unit T in the sheet conveyance direction. The side guide unit 14 includes a partially cylindrical R guide 48 that guides the continuous paper P along a conveyance path curved in a substantially cylindrical shape. The R guide portion 48 constitutes the R portion in the image forming apparatus 10. A fan-shaped side guide plate 47 is provided on one side of the R guide portion 48.

  An aligning roller 42 </ b> A is pivotally supported on the outer peripheral surface side of the R guide portion 48, and is in contact with the aligning roller 42 </ b> A at an opening provided in the R guide portion 48 on the inner peripheral surface side of the R guide portion 48. Thus, the backup roller 42B is pivotally supported.

  Both of the aligning roller 42A and the backup roller 42B are driven to rotate in contact with one end of the continuous paper P in the width direction, and are inclined with respect to the paper transport direction F (the downstream portion of the roller in the paper transport direction is the side). It is tilted toward the guide plate 47 side.

  As a result, when the continuous paper P passes between the aligning roller 42A and the backup roller 42B, the aligning roller 42A and the backup roller 42B are driven to rotate, and between the aligning roller 42A and the backup roller 42B and the continuous paper P. Due to this friction, a force in the direction toward the side guide plate 47 is exerted on the continuous paper P. Therefore, the continuous paper P abuts on the side guide plate 47 to correct the skew, and the continuous paper P is transported along the correct transport path.

  Under the backup roller 42B and the aligning roller 42A (upstream side in the sheet conveyance direction), a back tension unit 44 is provided as a tension applying unit that applies tension to the continuous sheet P conveyed by the drive roller 32 and the pinch roller 34. It has been.

  The back tension portion 44 includes a back tension drive roller 44A and a back tension pinch roller 44B. The back tension drive roller 44A is pivotally supported on the inner peripheral surface side of the R guide portion 48, and the back tension pinch roller 44B is a guide. It is pivotally supported on the outer peripheral surface side of the portion 48.

  The back tension drive roller 44A is composed of a group of rollers arranged in a direction perpendicular to the paper transport direction F. The back tension motor 18 has a rotation axis perpendicular to the paper transport direction F by the back tension motor 18. It rotates at a predetermined rotational speed. The back tension motor 18 is connected to a controller 16 that controls the transport amount of the continuous paper P transported by the back tension drive roller 44A by controlling the rotational speed of the back tension drive roller 44A.

  On the other hand, the back tension pinch rollers 44B are a group of driven rollers arranged in a plurality along a direction perpendicular to the paper conveyance direction F, and open along a direction perpendicular to the paper conveyance direction F. The portion is in contact with the back tension drive roller 44A and is pressed against the back tension drive roller 44A with a predetermined pressing force.

  The continuous paper P is sandwiched between the back tension drive roller 44A and the back tension pinch roller 44B, and the back tension drive roller 44A rotates at a peripheral speed lower than the peripheral speed of the drive roller 32, thereby applying tension to the continuous paper P. To do.

  A plurality of aging rollers 46 for feeding the continuous paper P is provided upstream of the side guide unit 14 in the paper conveyance direction, and the side guide unit 14 is provided between the image transfer unit T and the side guide unit 14. A plurality of guide rollers 38 for guiding the passed continuous paper P to the image transfer unit T are provided. Further, as the continuous paper P, roll paper, continuous paper that has been folded a plurality of times, or the like is used, and is conveyed from a paper supply unit (not shown) to a stacker (not shown).

  Further, the apparatus housing is provided with a display unit (warning means) 60 for displaying a warning or the like to the operator, and is connected to the control unit 16.

  Next, the operation of the image forming apparatus according to this embodiment will be described.

  In the image forming apparatus according to the present embodiment, (1) printing operation (image forming operation), (2) paper discharge operation with image fixing, and (3) advance paper without image fixing according to an operator's selective command. Perform feed operation.

  First, the printing operation will be described.

  When the control unit 16 of the image forming apparatus 10 according to the present embodiment receives a print command (image formation command) from the operator, the control unit 16 issues a drive command to the drive roller motor 12 and the back tension motor 18, and toner An image transfer command for transferring the image onto the continuous paper P is issued to the image forming unit 15, and an image fixing command for fixing the toner image transferred onto the continuous paper P is issued to the flash fixing device 21.

  As a result, the surface of the photosensitive drum 20 is charged by the charging corotron 24 and is exposed by the LED exposure optical system 26 to form a latent image on the surface. In the developing unit 28, toner is attached to the latent image, and a toner image transferred by the transfer corotron 22 onto the continuous paper P is formed on the surface of the photosensitive drum 20.

  After the toner image is transferred, the surface of the photosensitive drum 20 is neutralized by the neutralizing corotron 27, and the toner remaining on the surface without being transferred to the continuous paper P is removed by the cleaner 29.

  On the other hand, the continuous paper P set on the transport path by an operator or the like is nipped by the drive roller 32 and the pinch roller 34 so as not to slip and is transported in the paper transport direction F. At this time, the upstream portion of the continuous paper P in the paper conveyance direction is sandwiched by the back tension pinch roller 44B and the back tension drive roller 44A and is conveyed at a peripheral speed lower than the peripheral speed of the drive roller 32. . For this reason, the continuous paper P is pulled in a direction opposite to the paper transport direction F, and tension is applied to the continuous paper P.

  Further, one side edge of the continuous paper P on the upstream side in the paper conveyance direction is in contact with the side guide plate 47, the conveyance path is moved so as to be parallel to the side guide plate 47, and the skew is corrected.

  As described above, each page of the conveyed continuous paper P passes through the plurality of aging rollers 46, the side guide unit 14, and the plurality of guide rollers 38 in this order, and is introduced into the image transfer unit T.

  Each page of the continuous paper P introduced into the image transfer portion T is charged by the transfer corotron 22 with a polarity opposite to that of the toner of the formed toner image. As a result, the toner image on the surface of the photosensitive drum 20 is transferred to the continuous paper P.

  Each page of the continuous paper P onto which the toner image has been transferred in the image transfer unit T is guided to the flash fixing device 21 by the guide roller group 52, and is instantaneously heated by being irradiated with flash light in the flash fixing device 21. The As a result, the toner is melted and the toner image is fixed on the surface of the continuous paper P.

  Each page of the continuous paper P on which the toner image is fixed by the flash fixing device 21 is introduced between the drive roller 32 and the pinch roller 34 by the guide roller group 54 and sent to a stacker (not shown).

  As described above, when a series of printing operations are performed and image formation is performed on a predetermined page of the continuous paper P, the printing operation ends and the apparatus stops.

  When the apparatus is stopped, as shown in FIG. 3, the toner image between the image transfer portion T and the flash fixing device 21 is in an unfixed state (shaded area in FIG. 3). The toner image introduced into the flash fixing device 21 is fixed to the flash fixing device 21 to be in a fixed state (the black portion in FIG. 3).

  Next, a paper discharge operation with image fixing will be described.

  When the control unit 16 of the image forming apparatus 10 according to the present embodiment receives a paper discharge command accompanying image fixing from the operator, the control unit 16 issues a drive command to the drive roller motor 12 and the back tension motor 18 to perform flashing. An image fixing command is issued to the fixing device 21. At this time, the image transfer command is not issued to the image forming unit 15.

  As a result, each page of the continuous paper P onto which the toner image has been transferred in the image transfer unit T is guided to the flash fixing device 21 by the guide roller group 52, and flash light is emitted from the flash fixing device 21 instantaneously. To be heated. As a result, the toner is melted and the toner image is fixed on the surface of the continuous paper P.

  Each page of the continuous paper P on which the toner image is fixed by the flash fixing device 21 is introduced between the drive roller 32 and the pinch roller 34 by the guide roller group 54 and is sent to a stacker (not shown), where an unfixed portion of the toner image Disappears.

  Next, a forward paper feeding operation without image fixing will be described.

  When the control unit 16 of the image forming apparatus 10 according to the present embodiment receives a forward paper feed command from the operator, the control unit 16 issues a drive command to the drive roller motor 12 and the back tension motor 18. At this time, the image transfer command is not issued to the image forming unit 15, and the image fixing command is not issued to the flash fixing device 21.

  Thus, each page of the continuous paper P is conveyed in the F direction without image transfer and image fixing.

  This forward paper feeding operation is performed according to an instruction from the operator when a jam (paper jam in the transport path) occurs or when the transfer position to the continuous paper P needs to be adjusted.

  Here, a description will be given of a configuration in which the forward paper feed is interrupted when the continuous paper having an unfixed image to be formed is forward fed when the paper discharge operation with image fixing is not performed after the printing operation is completed. To do.

  As shown in FIG. 1, the control unit 16 is connected to a setting unit 62 as a setting unit that can set whether or not to execute the forward paper feed interruption operation of the control unit 16.

  Whether the setting unit 62 inputs the information on the validity / invalidity of the interruption operation performed by the control unit 16 to the control unit 16 when the operator operates the setting unit 62, and executes the interruption operation of the forward paper feed. It can be set whether or not.

  Thereby, when it is desired to give priority to the forward paper feeding operation of the control means, the interruption operation of the control means can be selectively prevented from being executed.

  That is, if the advance paper feeding is interrupted, subsequent processing (operation) is required, so that the processing speed and operability of the apparatus are reduced. However, when it is desired to prevent the processing speed and operability from being lowered, the control means It is possible not to execute the interruption operation.

  When it is set to execute the forward paper feed interruption operation, the control unit 16 performs the forward paper feed interruption operation in the following procedure.

  First, as shown in FIG. 2, in step 100, it is determined whether or not there is a print command. If there is a print command, the above-described printing operation is performed in step 102, a flag indicating that there is an unfixed image is set in step 104, and the process returns to step 100. Note that the flag is set when, for example, the image is transferred onto the continuous paper P by the image transfer unit T.

  If there is no print command in step 100, it is determined in step 106 whether there is a paper discharge command with image fixing. If there is a paper discharge command, the paper discharge operation with image fixing described above is performed in step 108, the flag indicating that there is an unfixed image is cleared in step 110, and the flow returns to step 100.

  If there is no paper discharge command in step 106, it is determined in step 112 whether there is a forward paper feed command. If there is a forward paper feed command, in step 114, the above-described forward paper feed operation is performed, and in step 116, it is determined whether the flag with an unfixed image is set. If there is no advance paper feed command in step 112, the process returns to step 100.

  If the unfixed image flag is set in step 116, the advance paper feed amount is measured by the rotary encoder 33 in step 118, and the measured advance paper feed amount exceeds the specified amount in step 120. It is determined whether or not. If the prescribed amount is exceeded, the advance paper feed is interrupted in step 122. Thereafter, in step 124, a warning is displayed on the display unit 60 to the operator so as to execute the paper discharge operation with image fixing, thereby prompting the paper discharge operation, and the process returns to step 100. In step 120, if the prescribed amount is not exceeded, the process returns to step 100.

  The prescribed amount is determined as follows.

  When the forward paper feeding operation is executed, a point (see the one-dot chain line A in FIGS. 3 and 4) where the first page with an unfixed image that is likely to pass through the flash fixing device 21 is to be stopped is set in advance. This point is, for example, the most downstream position where an unfixed image can be fixed when flash light of the flash fixing device 21 is irradiated to the stopped first page.

  The rotary encoder 33 measures the conveyance amount that the drive roller 32 has conveyed the continuous paper from the time when the transfer is performed, thereby detecting a point on the first page with an unfixed image after the printing operation is completed (FIG. 3). Dash-dotted line B, and dash-dotted line C in FIG. 4).

  That is, as shown in FIG. 3, when image formation is performed on continuous paper P having a length longer than that between the image transfer unit T and the flash fixing device 21, the first page with an unfixed image is This means that the flash fixing device 21 is on the front side of the most upstream position where fixing is possible (see the one-dot chain line B in FIG. 3).

  In addition, when printing is performed on continuous paper P that is less than the length between the image transfer unit T and the flash fixing device 21, for example, when printing is performed on only a few pages, it is shown in FIG. Thus, it becomes the position of the alternate long and short dash line C.

  The distance from the point at which the first page with an unfixed image after the printing operation ends to the point at which the head page with an unfixed image that is likely to pass through the flash fixing device 21 is to be stopped is a specified amount.

  That is, as shown in FIG. 3, when an image is formed on continuous paper P having a length longer than that between the image transfer portion T and the flash fixing device 21, the one-dot chain line A to the one-dot chain line in FIG. The distance L1 to B is a specified amount.

  When printing is performed on continuous paper P that is less than the length between the image transfer unit T and the flash fixing device 21, for example, the distance L2 from the alternate long and short dash line A to the alternate long and short dash line C in FIG. It becomes quantity.

  In the present embodiment, the specified amount is the maximum, the distance from the image transfer portion T to the one-dot chain line A, and the minimum is the distance from the one-dot chain line A to the one-dot chain line B.

  The specified amount varies depending on the distance from the image transfer portion T to the flash fixing device 21, the length of the flash fixing device 21 itself, the range of the fixable area of the flash fixing device 21, and the like.

  As shown in the above procedure, the control unit 16 interrupts the advance paper feed, so that the unfixed image on the continuous paper P is advanced immediately before passing through the flash fixing device 21, as shown in FIG. Paper feeding is interrupted, and the continuous paper P stops at that position. For this reason, even if the forward paper feed is performed, the components (particularly, the drive roller 32 and the pinch roller 34) arranged on the downstream side of the fixing unit are not stained with the unfixed image.

  In addition, the display unit 60 displays a warning to the operator so as to perform a paper discharge operation with a fixing operation. If the operator issues a paper discharge command accompanied by a fixing operation to the control unit 16 by this warning, the unfixed image is fixed on the continuous paper P that has been stopped immediately before passing through the flash fixing device 21. If the unfixed image is fixed, the unfixed image disappears, and even if the continuous paper is conveyed, the components (particularly, the drive roller 32 and the pinch roller 34) constituting the apparatus are not stained with the unfixed image.

  In the above-described embodiment, the rotary encoder 33 is described as a measurement unit that measures the transport amount of the continuous paper P fed forward by the control unit 16, but the measurement unit of the present invention is not limited thereto. For example, a configuration in which the conveyance amount of continuous paper is measured by a laser may be used, and any means capable of measuring the conveyance amount of continuous paper fed forward is possible.

  In the above embodiment, the specified amount is set so that the unfixed image on the continuous paper P is interrupted in advance paper feed immediately before the unfixed image passes through the flash fixing device 21. The specified amount is not limited to this. For example, the advance paper feed is interrupted at an arbitrary position between the flash fixing device 21 and the drive roller 32 and the pinch roller 34 and immediately before the drive roller 32 and the pinch roller 34. As described above, the specified amount may be set, and the specified amount can be set so as to interrupt the advance paper feed at an arbitrary position on the conveyance path.

  When the forward paper feed is interrupted after the unfixed image on the continuous paper P passes through the flash fixing device 21, the page of the continuous paper P with the unfixed image is moved back to the front of the flash fixing device 21. Alternatively, the unfixed image may be fixed.

  In the above embodiment, the display unit 60 as warning means for warning the operator so as to perform an operation involving fixing operation has been described. However, the warning means of the present invention is not limited to this, and for example, A warning means for warning with a warning sound or voice may be used, and any means can be used as long as the operator can recognize the warning.

  In the above embodiment, the image forming apparatus according to the present invention has been described with respect to an image forming apparatus that sandwiches and conveys a continuous sheet without a feed hole between a drive roller and a pinch roller (so-called pinless conveyance). The image forming apparatus may be, for example, an image forming apparatus that conveys continuous paper by engaging a tractor pin with a feed hole formed in a side edge of continuous paper, and an image that forms an image on continuous paper. Any forming apparatus may be used.

FIG. 1 is an overall configuration diagram of an image forming apparatus according to an embodiment of the present invention. FIG. 2 is a control flow showing a control procedure of the control unit according to the present embodiment. FIG. 3 is a diagram showing the prescribed amount according to the present embodiment. FIG. 4 is a diagram showing a prescribed amount according to the present embodiment. FIG. 5 is a diagram illustrating a case where the advance paper feeding according to the present embodiment is interrupted.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Image forming apparatus 16 Control part (control means)
21 Flash fixing device (fixing unit)
32 Drive roller (conveying means)
33 Rotary encoder (measuring means)
34 Pinch roller (conveying means)
60 Display (Warning means)
62 Setting part (setting means)
L1 distance (specified amount)
L2 distance (specified amount)
P Continuous paper

Claims (4)

Conveying means for conveying continuous paper;
A fixing unit for fixing the image transferred to the continuous paper;
Control means for feeding forward paper by causing the conveying means to convey a continuous sheet in a state where the fixing operation of the fixing unit is stopped;
Measuring means for measuring the transport amount of the continuous paper fed forward by the control means;
With
The image forming apparatus characterized in that the control means interrupts the advance paper feeding when the transport amount of a continuous sheet with an unfixed image measured by the measuring means exceeds a specified amount.   2. The image formation according to claim 1, wherein the specified amount is set so that advance paper feeding is interrupted before an unfixed image on the continuous paper finishes passing through the fixing unit. apparatus.   The image forming apparatus according to claim 2, further comprising a warning unit that warns an operator to execute a fixing operation of the fixing unit after the control unit interrupts forward paper feeding.   The image forming apparatus according to claim 1, further comprising a setting unit configured to set whether or not to execute the forward paper feeding interruption operation of the control unit.

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