JP2008203498A - Image forming apparatus and image forming method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a technique to continue image forming operation regardless of failure in the image forming operation, and reduce operator's trouble. <P>SOLUTION: While no failure is detected by a detection means, an ejection means ejects recording material on which an image is formed to a normal ejection tray out of a plurality of ejection trays. On the other hand, when a failure is detected by the detection means, the ejection means regards recording material on which the image is not normally formed due to the failure as abnormal recording material and ejects it to an ejection tray different from the normal ejection tray. When a failure is detected by the detection means, the image forming means re-executes the image forming operation for the image corresponding to the abnormal recording material. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an image forming technique for forming an image on a recording material, and more particularly to a technique for discharging a recording material on which an image is formed to a discharge tray.

  In the image forming apparatus described in Patent Document 1, an image is formed on a sheet as follows. First, the surface of the uniformly charged photoconductor is exposed to form an electrostatic latent image. Next, the electrostatic latent image is developed with toner to reveal the image, and the revealed image is transferred to the intermediate transfer belt. The image transferred to the intermediate transfer belt is conveyed to the secondary transfer unit. On the other hand, the sheet is conveyed to the secondary transfer unit by a pair of gate rollers. Thus, the image is transferred to the paper in the secondary transfer portion. Then, the image transferred to the paper is fixed on the paper by a fixing device, and an image is formed on the paper. The sheet on which the image is formed is discharged to a discharge tray.

JP 2006-133353 A JP 2004-284709 A

  However, in the operation of forming an image on a recording material such as paper (image forming operation), various abnormalities may occur. For example, Patent Document 2 describes an abnormality that a skew occurs in a conveyed sheet. Here, the skew means an abnormality in which the paper is transported with an inclination with respect to the transport direction. When the sheet is conveyed to the transfer area with such a skew, the image and the sheet are transferred while being inclined with respect to each other, and a good image cannot be formed on the recording material.

  Further, a technique is known in which a light beam is scanned on the surface of a photosensitive member by a rotating polygon mirror when the photosensitive member is exposed. When an image forming operation is performed using such a technique, an abnormality that the rotation period of the polygon mirror fluctuates may occur. As a result, a desired electrostatic latent image cannot be formed on the surface of the photoreceptor, and a good image may not be formed on the recording material.

  As described above, various abnormalities may occur in the image forming operation, and a good image may not be formed on the recording material due to the abnormalities. Then, when the recording material on which the image is formed is discharged to the discharge tray regardless of the occurrence of the abnormality, the recording material on which the image is formed based on the normal image forming operation has occurred in the discharge tray. In some cases, the recording material on which an image is formed based on the image forming operation coexists. When such a mixture occurs, there is a case where the operator has to separate and remove the recording material on which the image is formed based on the image forming operation in which an abnormality has occurred. Further, at this time, in order to form the removed recording material image on the recording material again, the operator stops the image forming operation continuously executed halfway, and performs the image forming operation for the removed image. In some cases, it was necessary to make the device execute. In other words, due to an abnormality in the image forming operation, there are cases where problems such as the trouble of the operator and the problem that the image forming operation cannot be executed continuously are caused. In particular, image forming apparatuses for business use are required to continuously execute a large amount of variable printing such as direct mail and bills for a long period of time. Therefore, in the image forming apparatus for business use, the occurrence of the above-mentioned problem becomes a big problem.

  The present invention has been made in view of the above problems, and an object thereof is to provide a technique that enables continuous execution of an image forming operation regardless of an abnormality that occurs in the image forming operation and that suppresses the trouble of an operator. To do.

  In order to achieve the above object, an image forming apparatus according to the present invention executes an image forming operation for forming an image on a recording material and conveys the recording material in a discharging direction, and a discharging direction of the image forming device. Are disposed between the image forming unit and the discharge tray unit, and are provided between the image forming unit and the discharge tray unit. A discharge unit that selectively discharges the recording material conveyed in the discharge direction from the forming unit to one of a plurality of discharge trays; and a detection unit that detects whether an abnormality has occurred in the image forming operation. The discharge means discharges the recording material on which the image is formed to a normal discharge tray among the plurality of discharge trays while the detection means detects no abnormality. Is detected, the recording material on which an image is not normally formed due to the abnormality is discharged as an abnormal recording material to a discharge tray different from the normal discharge tray. When detected, the image forming operation is performed again on the image corresponding to the abnormal recording material.

  In order to achieve the above object, an image forming method according to the present invention includes an image forming process for executing an image forming process for forming an image on a recording material, a detection process for detecting an abnormality in the image forming process, and a detection process. While no abnormality is detected by the process, the recording material on which the image is formed is discharged to the normal discharge tray among the plurality of discharge trays. On the other hand, if the abnormality is detected by the detection process, the recording material is normal due to the abnormality. A recording material in which an image is not formed is used as an abnormal recording material, and is discharged to a discharge tray different from the normal discharge tray. When the abnormality is detected by the detecting step, the abnormal recording material The image forming process is re-executed for the image corresponding to the above.

  The invention (image forming apparatus, image forming method) configured as described above executes an image forming operation (image forming process) for forming an image on a recording material, and detects an abnormality in the image forming operation. While the abnormality is not detected, the recording material on which the image is formed is discharged to the normal discharge tray among the plurality of discharge trays. On the other hand, if the abnormality is detected, the image is normally displayed due to the abnormality. The recording material that is not formed is used as an abnormal recording material and discharged to a discharge tray different from the normal discharge tray. Therefore, it is possible to suppress the occurrence of a problem that a recording material on which an image is normally formed and a recording material (an abnormal recording material) on which an image is not normally formed are mixed in the same discharge tray. Therefore, it is preferable that the troublesome operation of the operator of separating and removing the abnormal recording material is suppressed.

  Further, in the above invention, when an abnormality is detected, the image forming operation is re-executed for the image corresponding to the abnormal recording material. In other words, in the above invention, upon detection of an abnormality, the image corresponding to the abnormal recording material is automatically re-formed. Therefore, it is possible to reduce the necessity for the operator to stop the image forming operation that is continuously executed in the middle in order to form the image that has not been normally formed on the recording material again. Therefore, it is preferable that the image forming operation can be continuously executed regardless of the occurrence of the abnormality, and the trouble of the operator is suppressed.

  At this time, the discharge means discharges the recording material on which the image is formed by the image forming operation in which the abnormality is detected by the detection means to the discharge tray different from the normal discharge tray as the abnormal recording material. When an abnormality is detected by the detection means, the image forming operation related to the abnormality detection may be re-executed. With this configuration, the recording material (abnormal recording material) on which an image is formed by the image forming operation in which an abnormality has occurred is prevented from being mixed into the recording material discharged to the normal discharge tray. Further, the image forming operation in which an abnormality is detected is automatically re-executed. Therefore, it is preferable that the image forming operation can be continuously executed regardless of the occurrence of the abnormality, and the trouble of the operator is suppressed.

  The image forming unit further includes a conveyance start determining unit, and the image forming unit conveys the recording material from the stop position upstream in the discharge direction to the transfer region with respect to the transfer region. A recording material conveyance unit that conveys the image, and a transfer unit that, in the transfer area, transfers the image conveyed by the image conveyance unit to the recording material conveyed by the recording material conveyance unit, and then conveys the recording material in the discharge direction. The recording material conveyance unit conveys the recording material from the stop position to the transfer region in synchronization with conveyance of the image to the transfer region by the image conveyance unit, and the conveyance start determination unit detects an abnormality by the detection unit. If there is a transfer start subsequent image in which the transfer from the stop position of the corresponding recording material is started among the subsequent images scheduled to be formed after the image corresponding to the image forming operation in which the abnormality is detected. Whether or not And, discharging means based on a determination result of the conveyance start determination means, the recording material in the conveyance start subsequent image may choose whether to discharge to any of a plurality of discharge trays.

  In such a configuration, in the transfer region, the image conveyed by the image conveying unit is transferred to the recording material conveyed by the recording material conveying unit. The recording material conveyance unit conveys the recording material from the stop position to the transfer region in synchronization with the conveyance of the image to the transfer region by the image conveyance unit. That is, in such a configuration, the image is transferred to the recording material in the transfer region, but in order to execute such transfer well, it is necessary to superimpose the image and the recording material on each other. Therefore, in the above configuration, the recording material is made to wait once at the stop position in order to overlap the image and the recording material in the transfer region. Then, the recording material is conveyed from the stop position to the transfer area in synchronization with the timing at which the image is conveyed to the transfer area (in synchronization with the conveyance of the image to the transfer area). In this way, the transfer timing of the image and the recording material to the transfer region is adjusted, thereby realizing a good transfer between the image and the recording material.

  By the way, when a plurality of recording materials on which different images are formed are continuously ejected, it is preferable that the order of ejecting the recording materials does not change before and after the abnormality in the image forming operation. However, in the configuration in which the recording material is transported to the transfer area, for example, when an abnormality is detected in the image forming operation and the image forming operation associated with the abnormality detection is re-executed, the subsequent re-execution is already performed. When conveyance of the recording material from the stop position with respect to the image is started, the recording material is conveyed as it is to the transfer region.

  Therefore, in the above configuration, when an abnormality is detected by the detecting means, the corresponding recording material from the stop position of the subsequent image that is scheduled to be formed after the image corresponding to the image forming operation in which the abnormality is detected. The image forming apparatus further includes a conveyance start determination unit that determines whether there is a conveyance start subsequent image that has started to be conveyed, and the discharge unit records the recording material for the conveyance start subsequent image based on the determination result of the conveyance start determination unit. To which of a plurality of discharge trays is to be discharged. Therefore, it is possible to suppress the recording material discharge order before and after due to an abnormality in the image forming operation.

  At this time, when the conveyance start determination unit determines that there is a conveyance start subsequent image, the paper discharge unit is configured to record the recording material on which the image is formed by the image forming operation in which the abnormality is detected by the detection unit and the conveyance start subsequent All of the recording material for the image is discharged as an abnormal recording material to the discharge tray different from the normal discharge tray, and the image forming unit subsequently performs the image forming operation in which the abnormality is detected, You may comprise so that image formation operation may be performed about an image. This is because with this configuration, it is possible to suppress the occurrence of problems before and after the recording material discharge sequence, regardless of abnormalities in the image forming operation.

  On the other hand, when a plurality of recording materials each having the same image formed thereon are continuously discharged, there is no problem before and after the recording material discharge order. Therefore, it may be configured to further include setting means for setting replacement information indicating whether or not the discharge order can be changed when a plurality of recording materials on which images are formed are continuously discharged to the discharge tray. . When the conveyance start determination unit determines that there is a subsequent image after the conveyance start and indicates that the replacement information can be replaced, the paper discharge unit performs the image forming operation in which the abnormality is detected by the detection unit. The recording material on which the image is formed is discharged as an abnormal recording material to a discharge tray different from the normal discharge tray, and the image forming unit determines that the transfer start determination unit starts conveyance from the stop position. An image forming operation in which an abnormality is detected may be re-executed after the conveyance start subsequent image is formed on the recording material. In this way, by executing the image forming operation with reference to the replacement information, for example, the adjustment of the discharge order from the stop position prior to the re-execution of the image forming operation accompanying abnormality detection as described above, for example. This eliminates the need to perform operations such as discharging the recording material that has started to be transported (that is, the recording material for the subsequent images that have started transporting) to a discharge tray that is different from the normal discharge tray. Can be planned.

The image forming unit further includes a recording material supply unit that supplies the recording material to the image forming unit, and a supply start determination unit. When the abnormality is detected by the detection unit, the image formation in which the abnormality is detected is detected. Determining whether or not there is a supply start subsequent image in which supply of the corresponding recording material by the recording material supply means is started among subsequent images scheduled to be formed after the image corresponding to the operation;
The discharge unit may select which of the plurality of discharge trays discharges the recording material for the supply start subsequent image based on the determination result of the supply start determination unit.

  In the configuration as described above, the recording material is supplied to the image forming unit by the recording material supply unit. The image forming unit forms an image on the supplied recording material. By the way, when a plurality of recording materials on which different images are formed are continuously ejected, it is preferable that the order of ejecting the recording materials does not change before and after the abnormality in the image forming operation. However, when an abnormality is detected in the image forming operation and the image forming operation associated with the abnormality detection is re-executed, the supply of the recording material for the subsequent image has already started before the re-execution. The recording material is supplied to the image forming means as it is.

  Therefore, in the above configuration, when an abnormality is detected by the detection unit, supply of the corresponding recording material among the subsequent images scheduled to be formed after the image corresponding to the image forming operation in which the abnormality is detected starts. A supply start determining means for determining whether or not there is a supply start succeeding image, and the discharging means determines a plurality of recording materials for the supply start subsequent image based on the determination result of the supply start determining means. It is selected which of the discharge trays to discharge. Therefore, it is possible to suppress the recording material discharge order before and after due to an abnormality in the image forming operation.

  At this time, when the supply start determining unit determines that there is a supply start subsequent image, the paper discharge unit is configured to record the recording material on which the image is formed by the image forming operation in which the abnormality is detected by the detection unit and the supply start subsequent image. The recording material is discharged as an abnormal recording material to a discharge tray different from the normal discharge tray, and the image forming unit re-executes the image forming operation in which the abnormality is detected, An image forming operation may be executed. This is because with this configuration, it is possible to suppress the occurrence of problems before and after the recording material discharge sequence, regardless of abnormalities in the image forming operation.

  The apparatus further includes setting means for setting replacement information indicating whether or not the discharge order can be changed when a plurality of recording materials on which images are formed are continuously discharged to the discharge tray. If it is determined that there is a supply start succeeding image and the replacement information indicates that the replacement can be performed, the paper discharge unit records the image formed by the image forming operation in which the abnormality is detected by the detection unit. The material is discharged as an abnormal recording material to a discharge tray different from the normal discharge tray, and the image forming means applies the recording material to which the supply start determination means determines that the supply by the recording material supply means has started. An image forming operation in which an abnormality is detected may be re-executed after the supply start subsequent image is formed. As described above, by executing the image forming operation with reference to the replacement information, for example, the supply starts before the re-execution of the image forming operation accompanying the abnormality detection as described above in order to adjust the discharge order. It is not necessary to perform an operation such as discharging the recording material that is being used (that is, the recording material for the subsequent image after supply start) to a discharge tray different from the normal discharge tray, and the operation can be simplified. .

  FIG. 1 is a diagram showing an embodiment of a printer (image forming means) that can be used in the present invention. FIG. 2 is a block diagram showing an electrical configuration of the printer of FIG. The printer 1 forms a full color image by superposing four color toners (developers) of yellow (Y), cyan (C), magenta (M), and black (K), or black (K) toner. This is a printer that forms a monochrome image using only the printer. In this printer, when an image signal is given to the main controller 11 from an external device such as a host computer, the CPU 101 provided in the engine controller 10 controls each part of the engine unit EG according to a command from the main controller 11. Then, an image forming operation is executed to form an image corresponding to the image signal on the sheet ST (recording material).

  In the engine unit EG, the photosensitive member 22 is provided to be rotatable in the arrow direction D1 in FIG. A charging roller 23, a rotary developing unit 4 and a cleaning unit 25 are arranged around the photosensitive member 22 along the rotation direction D1. The charging roller 23 is applied with a predetermined charging bias, and charges the outer peripheral surface of the photosensitive member 22 to a predetermined surface potential. The cleaning unit 25 removes the toner remaining on the surface of the photosensitive member 22 after the primary transfer, and collects it in a waste toner tank provided inside. The photosensitive member 22, the charging roller 23, and the cleaning unit 25 integrally constitute the photosensitive member cartridge 2, and the photosensitive member cartridge 2 is detachably attached to the apparatus main body as a whole.

  Then, the light beam L is irradiated from the exposure unit 6 toward the outer peripheral surface of the photosensitive member 22 charged by the charging unit 23. The exposure unit 6 scans the photosensitive member 22 with a light beam L in accordance with an image signal given from an external device, and forms an electrostatic latent image corresponding to the image signal.

  The specific configuration of the exposure unit 6 can be executed by various techniques conventionally proposed. For example, the exposure unit 6 can be executed by the technique described in JP-A-9-71004. That is, in the technique described in the publication, the surface of the photoconductor is scanned by reflecting the light beam from the light source by the polygon mirror that rotates at a predetermined period. Further, as pointed out in the publication, if the rotation period of the polygon mirror fluctuates, a desired electrostatic latent image may not be formed on the surface of the photoreceptor. On the other hand, in the technique described in the publication, an optical sensor is arranged in a range where a light beam is scanned by a polygon mirror. Such an optical sensor functions as a horizontal synchronization sensor that detects a so-called horizontal synchronization signal. The publication describes that the fluctuation of the rotation period of the polygon mirror can be detected based on the fluctuation of the detection period of the horizontal synchronization signal. Therefore, in this embodiment, the horizontal synchronization sensor 601 is provided in the exposure unit 6 and the horizontal synchronization signal detected by the horizontal synchronization sensor 601 is output to the CPU 101. Then, the CPU 101 detects an operation abnormality when the rotation period of the polygon mirror fluctuates based on the period of the horizontal synchronization signal (polygon mirror operation abnormality detection).

  The electrostatic latent image thus formed is developed with toner by the developing unit 4. That is, in this apparatus, the developing unit 4 is configured as a support frame 40 that is rotatably provided around a rotation axis that is orthogonal to the paper surface of FIG. A yellow developing unit 4Y, a cyan developing unit 4C, a magenta developing unit 4M, and a black developing unit 4K are provided. The developing unit 4 is rotationally driven in the arrow direction D3 by a developing unit drive motor 47, which is a stepping motor controlled by the engine controller 10. Further, the apparatus main body is provided with a rotary lock 45 that comes into contact with and separates from the developing unit 4. If necessary, the rotary lock 45 abuts on the outer peripheral portion of the support frame 40 of the developing unit 4 to act as a brake and lock mechanism that restrains the rotation of the developing unit 4 and stops and positions the developing unit 4 at a predetermined position. .

  Then, based on a control command from the engine controller 10, the developing unit 4 is driven to rotate, and when these developing devices 4 Y, 4 C, 4 M, and 4 K are selectively positioned at a developing position that faces the photoreceptor 22. A developing roller 44 that is provided in the developing unit and carries toner of a selected color is disposed to face the photosensitive member 22 with a predetermined gap therebetween, and the surface of the photosensitive member 22 from the developing roller 44 at the opposed position. Toner is applied. As a result, the electrostatic latent image on the photosensitive member 22 is visualized (developed) with the selected toner color.

  The toner image developed by the developing unit 4 as described above is primarily transferred onto the intermediate transfer belt 71 of the transfer unit 7 in the primary transfer region TR1. The transfer unit 7 includes an intermediate transfer belt 71 stretched between a plurality of rollers 72 to 75, and a drive unit (not shown) that rotates the intermediate transfer belt 71 in a predetermined rotation direction D2 by rotationally driving the roller 73. It has. A secondary transfer region TR2 is provided on the downstream side in the rotation direction D2 of the intermediate transfer belt 71 with respect to the primary transfer region TR1. That is, the toner image primarily transferred onto the surface of the intermediate transfer belt 71 is conveyed to the secondary transfer region TR2 as the intermediate transfer belt 71 moves.

  When transferring a color image to the sheet ST, the color toner images formed on the photosensitive member 22 are superimposed on the intermediate transfer belt 71 to form a color image, and the color image is transferred to the secondary transfer region TR2. Carry up to. Then, the color image is secondarily transferred onto the sheet ST taken out from the cassette 8 and transported to the secondary transfer region TR2 along the transport path FF.

  The secondary transfer region TR2 (transfer region) is a nip portion where the surface of the intermediate transfer belt 71 stretched around the roller 73 and the secondary transfer roller 86 (transfer portion) that comes in contact with and separate from the belt surface come into contact. is there.

  The sheets ST stacked and stored in the cassette 8 are taken out one by one as the pickup roller 88 rotates. The taken sheet ST is placed on the conveyance path FF by the feed rollers 851 and 852, and is supplied in the discharge direction D5. Further, the sheets ST stacked and stored in the manual feed tray 8h are taken out one by one by the rotation of the pickup roller 88h. Then, the sheet ST taken out from the cassette 8 or the manual feed tray 8h is placed on the conveyance path FF by the feed rollers 851 and 852, and is supplied in the discharge direction D5. Then, the feed rollers 841, 842, 851, and 852 and the gate rollers 811 and 812 are rotated and conveyed to the secondary transfer region TR2 along the conveyance path FF in the discharge direction D5. Thus, in this embodiment, the cassette 8, the manual feed tray 8h, and the feed rollers 851 and 852 function as the “recording material supply unit” of the invention. In the following description, it may be determined whether or not the supply of the sheet ST by the recording material supply unit is started. However, the “state where the supply is started” means that the sheet is supplied by the feed rollers 851 and 852. It is assumed that the supply of ST (recording material) in the discharge direction D5 has started. That is, when the supply of the sheet ST is started, the leading end of the sheet ST (recording material) exceeds the nip portion of the feed rollers 851 and 852 in the discharge direction D5.

  FIG. 3 is a view showing a configuration around the gate roller. As shown in the figure, the pre-feed sheet detection sensor 804, the feed rollers 851, 852, the double feed detection sensor S81, the pre-gate sheet detection sensor 801, and the gate roller 811 are sequentially arranged from the upstream side in the discharge direction D5. 812, a skew detection sensor S82, and a secondary transfer position TR2. Further, the gate rollers 811 and 812 are disposed to face each other, and the feed rollers 851 and 852 are disposed to face each other. The gate rollers 811 and 812 synchronize with the conveyance timing of the image conveyed to the secondary transfer region TR2 as the intermediate transfer belt 77 rotates in order to correctly transfer the image on the intermediate transfer belt 71 onto the sheet ST. Then, the sheet ST is conveyed to the secondary transfer region TR2. Specifically, it is as follows.

  When the pre-gate sheet detection sensor 801 detects that the sheet ST conveyed on the conveyance path FF from the upstream side in the discharge direction D5 has arrived, the conveyance of the sheet ST is temporarily stopped at the stop position SP. As shown in the column “Stop Position” in the figure, in a state where the sheet ST is stopped at the stop position SP, the gate rollers 811 and 812 are in contact with each other at the downstream end ED1 in the discharge direction D5 of the sheet ST. It is abutted against the nip portion formed in this way. At this time, the pre-feed sheet detection sensor 804 is on (that is, the pre-feed sheet detection sensor 804 indicates that the sheet ST exists upstream of the feed rollers 851 and 852 in the discharge direction D5. Is detecting). Then, by restarting the rotation of the gate roller 81 in synchronization with the timing of the circumferential movement of the intermediate transfer belt 71, the conveyance from the stop position SP of the sheet ST toward the secondary transfer region TR2 is started. Thus, the sheet ST is sent to the secondary transfer region TR2 at a predetermined timing. The toner image formed on the intermediate transfer belt 71 is secondarily transferred onto the surface of the sheet ST that passes through the secondary transfer region TR2. Then, the sheet ST on which the secondary transfer has been executed is discharged in the discharge direction D5. As described above, in this embodiment, the transfer unit 7 functions as the “image transport unit” of the present invention, and the gate rollers 811 and 812 function as the “recording material transport unit” of the present invention. Further, the secondary transfer roller 86 functions as a “transfer portion” of the present invention.

  By the way, in the present embodiment, three detection operations of “size abnormality detection”, “double feed detection”, and “skew detection” are executed during conveyance from the stop position SP to the secondary transfer region TR2. Each will be described below.

  First, size abnormality detection will be described. As described above, in the state where the sheet ST is stopped at the stop position SP, the pre-feed sheet detection sensor 804 is turned on. Then, as shown in the column “Sheet detection sensor OFF before feeding” in the same figure, when the conveyance of the sheet ST from the stop position SP is started for a while, the upstream end ED2 in the discharge direction D5 of the sheet ST is fed. Passing the rollers 851 and 852, the pre-feed sheet detection sensor 804 is turned off. Here, the time interval from the start of conveyance of the sheet ST from the stop position SP to the time when the pre-feed sheet detection sensor 804 is turned off depends on the length of the sheet ST in the discharge direction D5. Therefore, in this embodiment, it is determined whether or not the size of the sheet ST is appropriate based on the result of measuring the time interval.

  Specifically, there is a time interval from when the conveyance of the sheet ST from the stop position SP is started (that is, after the rotation of the gate rollers 811 and 812 is restarted) until the pre-feed sheet detection sensor 804 is turned off. If it is less than the reference time interval, it is determined as a “paper short error”. On the other hand, if the time interval from the start of conveyance of the sheet ST from the stop position SP to the time when the pre-feed sheet detection sensor 804 is turned off exceeds the reference time interval, it is determined as a “paper length error”. Such determination is made by the CPU 101. Here, “paper short error” means an abnormal operation in which the size of the sheet ST that is actually conveyed is shorter than the size of the image to be formed, and “paper length error” means that the sheet is actually conveyed. This means an abnormal operation in which the size of the sheet ST is longer than the size of the image to be formed. In this way, size abnormality detection is executed.

  Next, double feed detection will be described. Here, the double feed means an abnormal operation in which two or more sheets ST are overlapped with each other in the discharge direction D5, and the double feed detection means detecting such an abnormal operation. Such double feed detection can be executed by various techniques conventionally proposed. For example, it can be executed by the technique described in Japanese Patent Laid-Open No. 4-32441. Below, the case where this technique is used is demonstrated.

  The double feed detection sensor S81 is a transmission type optical sensor having an emission part S81a for emitting light and a light receiving part S81b for receiving the light emitted from the emission part S81a so as to face the emission part S81a (see FIG. 3). Moreover, these emission part S81a and light-receiving part S81b are arrange | positioned so that conveyance path FF may be pinched | interposed. The emission unit S81a emits light toward the sheet ST conveyed along the conveyance path FF, and the light receiving unit S81b detects the amount of light transmitted through the sheet ST. Then, the CPU 101 detects double feeding based on the transmitted light amount detected by the light receiving unit S81b. That is, when the double feed occurs, the amount of transmitted light detected is smaller than when the double feed does not occur. Therefore, the CPU 101 detects double feeding when the amount of transmitted light is smaller than a predetermined value.

  Next, skew detection will be described. The skew means an operation abnormality that causes the sheet ST to be conveyed with an inclination with respect to the discharge direction D5, and the skew detection means that the operation abnormality is detected. Such skew detection can be executed by various techniques that have been proposed in the past. For example, the skew detection can be executed by the technique described in Japanese Patent Application Laid-Open No. 2004-284709. Below, the case where this technique is used is demonstrated.

  FIG. 4 is an explanatory diagram of skew detection. FIG. 5 is an explanatory diagram of a state where there is no skew. FIG. 6 is an explanatory diagram of a state where there is a skew. The skew detection sensor S82 includes two reflection type optical sensors S82a and S82b disposed to face the transport path FF. That is, each of the reflection type optical sensors S82a and S82b emits light to the conveyed sheet ST and detects the amount of light reflected by the sheet ST. The CPU 101 detects that the sheet ST has been conveyed to a position where each of the reflection type optical sensors S82a and S82b is opposed to each other when the amount of reflected light detected by each of the reflection type optical sensors S82a and S82b is equal to or greater than a certain value. Then, the CPU 101 detects the presence or absence of skew based on the timing difference at which the reflection type optical sensors S82a and S82b detect the sheet ST.

  As shown in FIG. 4, the reflection optical sensors S82a and S82b are disposed at the same position D5-1 in the transport direction D5, and the positions in the width direction WD orthogonal to the transport direction D5 are different from each other. Positions WD-1 and WD-2. Accordingly, when the sheet ST is conveyed in the discharge direction D5 without skew, the timing at which the downstream end ED1 in the discharge direction D5 of the sheet ST reaches the reflection type optical sensors S82a and S82b is reflected light. The same applies to both the sensors S82a and S82b (FIG. 5). On the other hand, when the sheet ST is conveyed in the discharge direction D5 in the presence of skew, the timing at which the downstream end ED1 in the discharge direction D5 of the sheet ST reaches the reflection type optical sensors S82a and S82b is reflected light. Each of the sensors S82a and S82b is different (FIG. 6). In the example shown in FIG. 6, the timing at which the end ED1 of the sheet ST reaches the reflection type optical sensor S82b is earlier than the timing at which the end ED1 of the sheet ST reaches the reflection type optical sensor S82a. Therefore, the CPU 101 detects the skew when the difference in timing at which each of the reflection type optical sensors S82a and S82b detects the end portion ED1 of the sheet ST is equal to or greater than a predetermined value.

  Returning to FIG. 1, the description will be continued. In the secondary transfer region TR2, the toner image is fixed on the sheet ST on which the image is transferred by the fixing unit 9. Thus, an image is formed on one surface of the sheet ST. In the present embodiment, an operation for forming an image on one surface of the sheet ST through the above-described process is referred to as an “image forming operation”. Then, the sheet ST on which the image is formed is conveyed to a multibin unit described later via the pre-discharge roller 82 and the discharge roller 83. When images are formed on both sides of the sheet ST, when the rear end portion of the sheet ST on which the image is formed on one side as described above is conveyed to the reverse position PR behind the pre-discharge roller 82, The rotation direction of the discharge roller 83 is reversed, whereby the sheet ST is conveyed in the direction of the arrow D4 along the reverse conveyance path FR. Then, it is placed again on the transport path FF before the gate roller 81. At this time, the image is transferred first on the surface of the sheet ST on which the image is transferred by contacting the intermediate transfer belt 71 in the secondary transfer region TR2. It is the opposite surface. In this way, images can be formed on both sides of the sheet ST.

  In addition to the above-mentioned pre-gate sheet detection sensor 801, sheet detection sensors 802 to 804 for detecting whether or not a sheet has passed on the path are provided at positions on the sheet conveyance path FF and the reverse conveyance path FR. The sheet conveyance timing is managed based on the outputs of these sensors, and jam detection is performed at each position.

  A cleaner 76 is disposed in the vicinity of the roller 75. The cleaner 76 includes a cleaner blade 761 that can move toward and away from the roller 75 by an electromagnetic clutch (not shown), and a waste toner tank 762. Then, the cleaner blade 761 abuts on the surface of the intermediate transfer belt 71 stretched over the roller 75 in a state of moving to the roller 75 side, and the toner remaining on the outer peripheral surface of the intermediate transfer belt 71 after the secondary transfer is removed. Remove by scraping. The toner scraped off is stored in a waste toner tank 762. The waste toner tank 762 is provided with a waste toner sensor 763 for detecting that the tank is full.

  The cleaner blade 761 is controlled to be separated and abutted so as to remove the toner remaining on the intermediate transfer belt 71 in the same rotation when the image is transferred to the sheet ST in the secondary transfer region TR2. The Therefore, for example, when the apparatus continuously forms monochrome images, the image transferred to the intermediate transfer belt 71 in the primary transfer region TR1 is immediately transferred to the sheet ST in the secondary transfer region TR2, and thus the cleaner blade 761. Is held in contact. On the other hand, when forming a color image, it is necessary to keep the cleaner blade 761 away from the intermediate transfer belt 71 while the toner images of the respective colors are superimposed on each other. Then, the toner images of the respective colors are superimposed on each other to complete a full color image, and the cleaner blade 761 is brought into contact with the intermediate transfer belt 71 in order to remove residual toner in the same rotation as the secondary transfer onto the sheet ST. The Rukoto.

  Further, a density sensor 60 and a vertical synchronization sensor 77 are arranged in the vicinity of the roller 75. The density sensor 60 is provided to face the surface of the intermediate transfer belt 71 and measures the image density of the toner image formed on the outer peripheral surface of the intermediate transfer belt 71 as necessary. Based on the measurement results, this apparatus adjusts the operating conditions of each part of the apparatus that affects the image quality, for example, the developing bias applied to each developing device, the intensity of the light beam L, and the like. The density sensor 60 is configured to output a signal corresponding to the image density of a region of a predetermined area on the intermediate transfer belt 71 using, for example, a reflection type photosensor. The CPU 101 can detect the image density of each part of the toner image on the intermediate transfer belt 71 by periodically sampling the output signal from the density sensor 60 while rotating the intermediate transfer belt 71.

  The vertical synchronization sensor 77 is a sensor for detecting the reference position of the intermediate transfer belt 71 and is used to obtain a synchronization signal output in association with the rotational drive of the intermediate transfer belt 71, that is, a vertical synchronization signal Vsync. Functions as a sensor. In this apparatus, the operation of each part of the apparatus is controlled based on the vertical synchronization signal Vsync in order to align the operation timing of each part and accurately superimpose the toner images formed in the respective colors.

  Further, memory tags 49Y, 49C, 49M, and 49K are respectively attached to the outer peripheral surfaces of the developing devices 4Y, 4C, 4M, and 4K that correspond to the side surfaces of the developing unit 4 that has a substantially cylindrical shape as a whole. For example, a memory tag 49Y attached to the yellow developing device 4Y is electrically connected to the memory 491Y for storing data relating to the manufacturing lot and usage history of the developing device, the remaining amount of built-in toner, and the like. Loop antenna 492Y. In addition, memory chips 491C, 491M, and 491K and loop antennas 492C, 492M, and 492K are also provided in the memory tags 49C, 49M, and 49K provided in the other developing devices, respectively.

  On the other hand, a wireless communication antenna 109 is also provided on the apparatus main body side. The wireless communication antenna 109 is driven by a transceiver 105 connected to the CPU 101, and by performing wireless communication with the wireless communication antenna on the developing device side, the CPU 101 and a memory provided in the developing device Various data such as consumables management related to the developing device are managed by transmitting and receiving data between them.

  Further, as shown in FIG. 2, this apparatus includes a display unit 12 that is controlled by the CPU 111 of the main controller 11. In response to a control command from the CPU 111, the display unit 12 displays a predetermined message for informing operation guidance to the user, the progress of the image forming operation, the occurrence of an abnormality in the apparatus, the replacement timing of any unit, and the like. indicate. In the present embodiment, the display unit 12 is configured by a touch panel, for example, so that the user can input predetermined information via the display unit 12.

  In FIG. 2, reference numeral 113 denotes an image memory provided in the main controller 11 for storing an image given from an external device such as a host computer via the interface 112. Reference numeral 106 is a ROM for storing a calculation program executed by the CPU 101, control data for controlling the engine unit EG, and the like. Reference numeral 107 is a RAM for temporarily storing calculation results in the CPU 101 and other data. is there.

  FIG. 7 is a diagram schematically showing the configuration of the multi-bin unit. The multi-bin unit 3 (discharge unit) has a common conveyance path 32 that conveys the sheet ST conveyed into the unit by the discharge roller 83 of the printer 1. The common transport path 32 branches at different branch positions, and ten bins BIN1 to BIN10 (discharge tray portions) are stacked in a vertical direction. In this embodiment, the bin BIN10 is arranged on the upstream side of the common conveyance path 32, and the bins BIN9 to BIN1 are arranged in this order as proceeding to the downstream side (upward side in the drawing).

  A branch claw 33 for switching the discharge destination of the sheet ST corresponding to each branch position on a one-to-one basis is swingably provided. Then, each of the branching claws 33 is rocked and positioned by a discharge destination switching control unit 315 (FIG. 8) of the multi-bin unit controller 31 described later, so that the sheet ST conveyed along the common conveyance path 32 is changed. A plurality of bins BIN1 to BIN10 are selectively discharged into one bin (discharge tray). That is, each of the bins BIN1 to BIN10 receives the discharged sheet ST.

  In each of the bins BIN1 to BIN10, a sheet detection sensor S31 that detects whether or not the sheet ST is stored in the bin, and whether or not the sheet storage amount in the bin reaches a preset upper limit amount. A pair of storage limit detection sensors S32 for detection is provided. Further, a single discharge sensor S33 is provided for detecting sheet discharge to the bins BIN1 to BIN10.

  The discharge sensor S33 includes a light projecting portion S33a disposed at the inner bottom portion of the unit body 34 and a light receiving portion S33b disposed at the inner top portion of the unit body 34. The light projecting portion S33a is in the vicinity of the branch position. Then, all the bins BIN1 to BIN10 are irradiated with the light beam L in a skewered manner, and the light beam L can be received by the light receiving unit S33b disposed opposite to the light projecting unit S33a. For this reason, while the sheet ST is being ejected to the bin while traversing the optical path of the light beam L, the light beam L is shielded. On the other hand, when the sheet ejection to the bin is completed, the sheet ST passes through the optical path. The light beam L is received by the light receiving unit S33b and the transmission of the light beam L is detected. Thus, the sheet discharge to the bin is detected by the discharge sensor S33.

  FIG. 8 is a diagram showing an electrical configuration of a multi-bin unit controller provided in the multi-bin unit main body in order to control the multi-bin unit shown in FIG. In this multi-bin unit controller 31 (discharge means), various information is given to the CPU 312 from the engine controller 10 of the printer 1 through the communication interface 311 together with detection signals from the sensor groups S31 to S34 provided in the multi-bin unit 3. It is configured to be. The CPU 312 controls each part of the multi-bin unit according to a program stored in advance in the ROM 313 based on these signals and information. Reference numeral S34 denotes a carry-in detection sensor that is disposed in the vicinity of the sheet carry-in port 341 of the multi-bin unit 3 and detects the carry-in of the sheet.

In order to control each part of the multi-bin unit 3, the following control unit is electrically connected to the CPU 312.
(a) Main motor drive control unit 314: Drives and controls a main motor (not shown) that is a drive source of each part of the multi-bin unit 3.
(b) Discharge destination switching control unit 315: The branch claw 33 is driven to swing, and the discharge destination of the sheet ST is selected from a plurality of bins BIN1 to BIN10.

  The multi-bin unit controller 31 changes the AC power supplied through the AC input unit 316 to a direct current having a predetermined voltage by the power source unit 317 and serves as a power source in the multi-bin unit 3. In particular, in this embodiment, the power supply from the AC input unit 316 is remotely controlled by the printer 1 by controlling the conduction / non-conduction of the AC relay 317 a provided in the power supply unit 317 based on the relay control signal from the printer 1. It is configured to be controllable. Note that reference numeral 318 in the figure is a RAM for temporarily storing control data for controlling each part of the multi-bin unit 3 and a calculation result in the CPU 312.

  As described above, in the image forming operation executed by the printer 1, various abnormalities (polygon mirror operation abnormality, size abnormality, double feeding, skew) occur. When such an abnormality occurs, good image formation on the sheet ST cannot be realized. When the sheet ST on which an image is formed regardless of whether or not such abnormality has occurred is discharged to a bin BIN (discharge tray), the sheet on which an image is formed based on a normal image forming operation in the bin BIN, In some cases, a sheet on which an image is formed based on the image forming operation in which the image is generated coexists. Therefore, in the above embodiment, an abnormality in the image forming operation is detected, and the image forming operation is controlled based on the detection result.

  FIG. 9 is a flowchart illustrating an example of control of the image forming operation. FIG. 10 is a diagram showing an example of specific operations executed in the flow of FIG. FIG. 10 shows a case where four images IM1 to IM4 are formed on different sheets ST. In FIG. 10, for example, “IM1” added to the sheet ST in the “printer” column means the sheet ST on which the image forming operation is executed in the printer 1 and the image IM1 is formed. The same applies to other descriptions in the “printer” column of FIG. Further, the images IM1 to IM4 shown in FIG. 10 are different from each other, and the sheet ST on which the images IM1 to IM4 are formed is preferably discharged in the order of the images IM1 to IM4. Based on these premises, an example of control of the image forming operation will be described.

  When the image signal is given to the main controller 11, the CPU 101 controls each part of the engine unit EG and starts an image forming operation (step STEP101). When the image forming operation is started, the CPU 101 (detection means) monitors whether any abnormality of polygon mirror operation, size abnormality, double feed, or skew is detected (step STEP102, detection process). While no abnormality is detected, the sheet ST on which an image is formed by the image forming operation is conveyed to the multi-bin unit 3 and discharged to the bin BIN1 (normal discharge tray) (step STEP103, discharge process). . In the operation example shown in FIG. 10, no abnormality is detected in the image forming operation of the first image IM1, and the sheet ST on which the image IM1 is formed is discharged from the printer 1 to the bin BIN1. If it is determined in step STEP102 that an abnormality has been detected, the sheet ST on which an image has been formed by the image forming operation relating to the abnormality detection is discharged as an abnormal recording material to the bin BIN2 (step STEP104, discharge process). In the operation example shown in FIG. 10, the CPU 101 determines that an abnormality has been detected during the image forming operation related to the image IM2, and as a result, the sheet ST on which the image IM2 is formed is discharged from the printer 1 to the bin BIN2. The That is, in the operation example shown in FIG. 10, the CPU 101 determines that the image IM2 is not normally formed on the sheet ST due to the detected abnormality, and uses the sheet ST on which the image IM2 is formed as an abnormal recording material. The paper is discharged to a bin BIN2 different from the bin BIN1.

  When an abnormality is detected, the sheet ST is stopped for the subsequent images (images IM3 and IM4) that are to be formed after the image (image IM2) corresponding to the image forming operation in which the abnormality is detected. The CPU 101 (conveyance start determining means) determines whether or not the conveyance from the position SP has started (that is, whether or not the rotation of the gate roller 81 has been resumed) (step STEP105). The operation example shown in FIG. 10 corresponds to a case where it is determined in step STEP105 that the conveyance of the subsequent image from the stop position SP of the sheet ST has not started. In this case, the process proceeds to step STEP 107, and execution of an image forming operation (image forming process) related to abnormality detection is started (image forming process). That is, re-execution of the image forming operation for the image IM2 is started. Subsequently, the image forming operation for the subsequent image IM3 is started (step STEP109). Then, the above-described flow is executed until the image forming operation for all the images IM1 to IM4 is completed. The operation example shown in FIG. 10 corresponds to a case where no abnormality is detected in the image forming operation after the re-execution of the image forming operation related to the image IM2. As a result of the above operation, as shown in the column “BIN1” in FIG. 10, the four sheets ST on which the images IM1 to IM4 are normally formed are discharged to the bin BIN1 in the order of the images IM1 to IM4. .

  FIG. 11 is a diagram showing another example of specific operations executed in the flow of FIG. The operation example shown in FIG. 10 shows a case where “NO” is determined in step STEP 105, that is, a case where it is determined that conveyance of the subsequent image from the stop position SP of the sheet ST has not started. On the other hand, the operation example shown in FIG. 11 corresponds to a case where “YES” is determined in step STEP 105, that is, a case where it is determined that conveyance of the subsequent image IM 3 from the stop position SP of the sheet ST is started. To do. A subsequent image in which the conveyance of the corresponding sheet ST from the stop position SP has already started is particularly referred to as a conveyance start subsequent image. The assumptions other than the determination in step STEP105 are the same as those in FIGS. The operation before step STEP105 is the same as the operation shown in FIG.

  If “YES” is determined in step STEP 105, the conveyance start subsequent image IM3 is formed on the sheet ST that has already started conveyance, and the sheet ST on which the conveyance start subsequent image IM3 is formed is abnormally recorded. Discharge to bin BIN2 as material. The reason for this is as follows. The conveyance start subsequent image IM3 is an image to be formed on the sheet ST after the image IM2. However, in the operation example shown in FIG. 11, due to the abnormality detected in the image forming operation related to the image IM2, the image IM3 that should originally be formed after the image IM2 is formed on the sheet ST before the image IM2. Will be formed. That is, the image IM3 is not normally formed on the sheet ST due to the abnormality detected in the image forming operation related to the image IM2. Therefore, in the operation example shown in FIG. 11, the sheet ST on which the conveyance start subsequent image IM3 is formed is discharged to the bin BIN2 as an abnormal recording material.

  Next, proceeding to step STEP 107, execution of an image forming operation related to abnormality detection is started. That is, re-execution of the image forming operation for the image IM2 is started. Following this, image forming operations for the subsequent images IM3 and IM4 are started in this order (step STEP109). Then, the above-described flow is executed until the image forming operation for all the images IM1 to IM4 is completed. Note that the operation example shown in FIG. 11 corresponds to a case where no abnormality is detected in the image forming operation after the re-execution of the image forming operation related to the image IM2. As a result of the above operation, as shown in the column “BIN1” in FIG. 11, the four sheets ST on which the images IM1 to IM4 are normally formed are discharged to the bin BIN1 in the order of the images IM1 to IM4. .

  As described above, in the above-described embodiment, the image forming operation (image forming process) for forming an image on the sheet ST (recording material) is executed, and an abnormality in the image forming operation is detected (step STEP102). While the abnormality is not detected, the sheet ST on which the image is formed is discharged to the bin BIN1 (normal discharge tray) (step STEP103). On the other hand, if the abnormality is detected, the image is normally displayed due to the abnormality. The sheet ST on which no is formed is discharged as an abnormal recording material into a bin BIN2 different from the bin BIN1 (step STEP104). Accordingly, as shown in the column “BIN1” in FIGS. 10 and 11, a sheet ST on which an image is normally formed and a sheet ST (abnormal recording material) on which an image is not normally formed are in bin BIN1. Occurrence of the problem of mixing is suppressed. Therefore, it is preferable that the troublesome operation of the operator of separating and removing the abnormal recording material is suppressed.

  Further, in the above embodiment, when an abnormality is detected, the image forming operation is re-executed for the image corresponding to the abnormal recording material (step STEP 107). In other words, in the above-described embodiment, when an abnormality is detected, the image corresponding to the abnormal recording material is automatically re-formed. Therefore, in order to form an image that has not been normally formed on the sheet ST (recording material) again, it is possible to reduce the necessity for the operator to stop the image forming operation that is continuously executed halfway. Therefore, it is preferable that the image forming operation can be continuously executed regardless of the occurrence of the abnormality, and the trouble of the operator is suppressed.

  In the above-described embodiment, the CPU 101 starts conveyance from the stop position of the corresponding sheet ST among the subsequent images scheduled to be formed after the image corresponding to the image forming operation in which the abnormality is detected. It is determined whether there is a start subsequent image. Based on the result of the determination, the bin BIN to which the sheet ST for the conveyance start subsequent image is discharged is selected.

  More specifically, when it is determined that there is an image following the start of conveyance, a sheet ST (recording material) on which an image has been formed by an image forming operation in which an abnormality has been detected, and a sheet ST (recording material) for the subsequent image after conveyance start Are discharged as an abnormal recording material into a bin BIN2 different from the bin BIN1 (normal discharge tray) (steps STEP104 to STEP106). Then, the printer 1 is configured to execute the image forming operation on the subsequent image following the re-execution of the image forming operation in which the abnormality is detected (steps STEP107 and STEP108). Therefore, in the above-described embodiment, it is possible to suppress the occurrence of the problem before and after the discharge order of the sheets ST (recording material) regardless of the abnormality of the image forming operation, which is preferable.

  By the way, when a plurality of sheets ST (recording materials) each having the same image are continuously discharged, or when a plurality of direct mails having different destinations are printed in a variable manner, the sheets ST are discharged. There is no problem before and after the order. Therefore, next, an image forming operation executed on the premise that “the discharge order of the sheets ST on which the images IM1 to IM4 are formed does not matter” will be described.

  FIG. 12 is a flowchart illustrating another example of the control of the image forming operation. FIG. 13 is a diagram showing an example of specific operations executed in the flow of FIG. FIG. 13 shows a case where four images IM1 to IM4 are formed on different sheets ST. The flow shown in FIG. 12 and the flow shown in FIG. 9 are provided with step STEP 201 for determining whether or not the discharge order of the sheet ST can be changed after it is determined “YES” in step STEP 105. The difference is that the following steps STEP202 and STEP203 are provided. Regarding other points, the flow shown in FIG. 12 and the flow shown in FIG. 9 are the same. Therefore, below, it demonstrates focusing on a different part.

  When the image signal is given to the main controller 11, the CPU 101 controls each part of the engine unit EG and starts an image forming operation (step STEP101). When the image forming operation is started, the CPU 101 (detecting means) monitors whether an abnormality is detected (step STEP102). While no abnormality is detected, the sheet ST on which an image is formed by the image forming operation is conveyed to the multi-bin unit 3 and discharged to the bin BIN1 (normal discharge tray) (step STEP103). In the operation example shown in FIG. 13, no abnormality is detected in the image forming operation of the first image IM1, and the sheet ST on which the image IM1 is formed is discharged from the printer 1 to the bin BIN1. If it is determined in step STEP102 that an abnormality has been detected, the sheet ST on which an image has been formed by the image forming operation relating to the abnormality detection is discharged as an abnormal recording material to the bin BIN2 (step STEP104). In the operation example shown in FIG. 13, the CPU 101 determines that an abnormality has been detected during the image forming operation related to the image IM2, and as a result, the sheet ST on which the image IM2 is formed is discharged from the printer 1 to the bin BIN2. The That is, in the operation example shown in FIG. 13, the CPU 101 determines that the image IM2 is not normally formed on the sheet ST due to the detected abnormality, and uses the sheet ST on which the image IM2 is formed as an abnormal recording material. The paper is discharged to a bin BIN2 different from the bin BIN1.

  Further, when an abnormality is detected, the sheet ST is stopped with respect to subsequent images (images IM3 and IM4) that are to be formed after the image (image IM2) corresponding to the image forming operation in which the abnormality is detected. The CPU 101 (conveyance start determining means) determines whether or not the conveyance from the position SP has started (that is, whether or not the rotation of the gate roller 81 has been resumed) (step STEP105). If “YES” is determined in step STEP 105, the process proceeds to step STEP 201, and the CPU 101 refers to replacement information indicating whether or not the discharge order can be switched. Note that the operation example shown in FIG. 13 corresponds to a case where it is determined that conveyance of the sheet ST from the stop position SP of the subsequent image IM3 has started. That is, the subsequent image IM3 is a conveyance start subsequent image. Such replacement information is information indicating whether or not the discharge order can be changed when a plurality of sheets on which images are formed are discharged continuously. The replacement information is set in the RAM 107 of the engine controller 10 by the operator via the display unit 12. Specifically, when the operator is not concerned with the discharge order, the operator inputs to the display unit 12 that the discharge order can be changed. The replacement information input to the display unit 12 is set in the RAM 107 (setting unit) via the CPU 111 and CPU 101.

  If it is determined in step S201 that the discharge order can be changed, the image forming operation for the conveyance start subsequent image IM3 is started (step STEP202), and then the image IM2 related to abnormality detection is detected. Re-execution of the image forming operation is started (step STEP 203). At this time, the conveyance start subsequent image IM3 is subjected to image formation on the sheet determined by the conveyance start determination unit to start conveyance from the stop position SP. The operation shown in FIG. 13 corresponds to the case where “YES” is determined in step STEP 201 after “YES” is determined in step STEP 105. As a result, as indicated by the column “BIN1” in FIG. 9, the discharge order of the sheet ST on which the image IM2 is formed and the sheet ST on which the image IM3 is formed into the bin BIN1 is reversed.

  If “NO” is determined in step STEP 201 (that is, it is impossible to change the discharge order), the process proceeds to step STEP 106 and the same operation as that of the embodiment described above is executed. Note that the operation example shown in FIG. 13 corresponds to a case where no abnormality is detected in the image forming operation after the execution of the image forming operation related to the image IM3. As a result of the above operation, as shown in the column “BIN1” in FIG. 13, the four sheets ST on which the images IM1 to IM4 are normally formed are discharged to the bin BIN1.

  Thus, in the embodiment shown in FIGS. 12 and 13, the sheet ST on which the image IM2 is formed by the image forming operation in which an abnormality is detected is discharged to the bin BIN2 different from the bin BIN1. Therefore, it is preferable that only the sheet ST on which an image is normally formed is discharged to the bin BIN1.

  If an abnormality is detected, the image forming operation is performed again for the image IM2 corresponding to the abnormal recording material (step STEP203). That is, in the above-described embodiment, in response to detection of an abnormality, the image IM2 corresponding to the abnormal recording material is automatically re-formed. Therefore, in order to form an image that has not been normally formed on the sheet ST (recording material) again, it is possible to reduce the necessity for the operator to stop the image forming operation that is continuously executed halfway. Therefore, it is preferable that the image forming operation can be continuously executed regardless of the occurrence of the abnormality, and the trouble of the operator is suppressed.

  Further, in the above-described embodiment, when it is determined that the discharge order can be changed with reference to the replacement information set in the RAM 107, the conveyance starts for the sheet ST that has already started conveyance from the stop position SP. Following the formation of the subsequent image (step STEP 202), the image forming operation in which an abnormality is detected is re-executed. That is, by performing the image forming operation with reference to the replacement information, for example, the adjustment from the stop position SP prior to the re-execution of the image forming operation associated with the abnormality detection as described above is performed in order to adjust the discharge order. It is not necessary to perform an operation such as discharging the sheet ST that has been transported to a bin BIN2 that is different from the bin BIN1, and the operation can be simplified.

  FIG. 14 is a flowchart illustrating another example of the control of the image forming operation. FIG. 15 is a diagram showing an example of specific operations executed in the flow of FIG. FIG. 15 shows a case where four images IM1 to IM4 are formed on different sheets ST. In FIG. 15, for example, “IM1” added to the sheet ST in the “printer” column means the sheet ST on which the image IM1 is formed by executing the image forming operation in the printer 1. The same applies to other descriptions in the “printer” column of FIG. Further, the images IM1 to IM4 shown in FIG. 15 are different from each other, and the sheet ST on which the images IM1 to IM4 are formed is preferably discharged in the order of the images IM1 to IM4. Based on these premises, an example of control of the image forming operation will be described.

  When the image signal is given to the main controller 11, the CPU 101 controls each part of the engine unit EG and starts an image forming operation (step STEP101). When the image forming operation is started, the CPU 101 (detection means) monitors whether any abnormality of polygon mirror operation, size abnormality, double feed, or skew is detected (step STEP102, detection process). While no abnormality is detected, the sheet ST on which an image is formed by the image forming operation is conveyed to the multi-bin unit 3 and discharged to the bin BIN1 (normal discharge tray) (step STEP103, discharge process). . In the operation example shown in FIG. 15, no abnormality is detected in the image forming operation of the first image IM1, and the sheet ST on which the image IM1 is formed is discharged from the printer 1 to the bin BIN1. If it is determined in step STEP102 that an abnormality has been detected, the sheet ST on which an image has been formed by the image forming operation relating to the abnormality detection is discharged as an abnormal recording material to the bin BIN2 (step STEP104, discharge process). In the operation example shown in FIG. 15, the CPU 101 determines that an abnormality has been detected during the image forming operation related to the image IM2, and as a result, the sheet ST on which the image IM2 is formed is discharged from the printer 1 to the bin BIN2. The That is, in the operation example shown in FIG. 15, the CPU 101 determines that the image IM2 is not normally formed on the sheet ST due to the detected abnormality, and uses the sheet ST on which the image IM2 is formed as an abnormal recording material. The paper is discharged to a bin BIN2 different from the bin BIN1.

  When an abnormality is detected, the sheet ST (recording) is performed on subsequent images (images IM3 and IM4) that are to be formed after the image (image IM2) corresponding to the image forming operation in which the abnormality is detected. CPU 101 (supply start determination means) determines whether or not the supply of the material (material) has started (that is, whether or not the feed rollers 851 and 852 have started supplying the sheet ST (recording material) in the discharge direction D5). Is determined (step STEP305). The operation example shown in FIG. 15 corresponds to the case where it is determined in step STEP 305 that the supply of the sheet ST to the subsequent image is not started. In this case, the process proceeds to step STEP 107, and execution of an image forming operation (image forming process) related to abnormality detection is started (image forming process). That is, re-execution of the image forming operation for the image IM2 is started. Subsequently, the image forming operation for the subsequent image IM3 is started (step STEP109). Then, the above-described flow is executed until the image forming operation for all the images IM1 to IM4 is completed. The operation example shown in FIG. 15 corresponds to the case where no abnormality is detected in the image forming operation after the re-execution of the image forming operation related to the image IM2. As a result of the above operation, as shown in the column “BIN1” in FIG. 15, the four sheets ST on which the images IM1 to IM4 are normally formed are discharged to the bin BIN1 in the order of the images IM1 to IM4. .

  FIG. 16 is a diagram illustrating another example of specific operations executed in the flow of FIG. In the operation example shown in FIG. 15, the case where “NO” is determined in step STEP 305, that is, the case where it is determined that the supply of the sheet ST to the subsequent image is not started is shown. On the other hand, the operation example shown in FIG. 16 corresponds to the case where “YES” is determined in step STEP 305, that is, the case where it is determined that the supply of the sheet ST to the subsequent image IM 3 is started. A subsequent image in which the supply of the corresponding sheet ST has already started is particularly referred to as a supply start subsequent image. The assumptions other than the determination in step STEP 305 are the same as those in FIGS. 15 and 16. Note that the operation before step STEP 305 is the same as the operation shown in FIG.

  If “YES” is determined in step STEP 305, the supply start subsequent image IM 3 is formed on the sheet ST that has already started supply, and the sheet ST on which the supply start subsequent image IM 3 is formed is abnormally recorded. Discharge to bin BIN2 as material. The reason for this is as follows. The supply start subsequent image IM3 is an image to be formed on the sheet ST after the image IM2. However, in the operation example shown in FIG. 16, due to the abnormality detected in the image forming operation related to the image IM2, the image IM3 that should originally be formed after the image IM2 is applied to the sheet ST before the image IM2. Will be formed. That is, the image IM3 is not normally formed on the sheet ST due to the abnormality detected in the image forming operation related to the image IM2. Therefore, in the operation example shown in FIG. 16, the sheet ST on which the supply start subsequent image IM3 is formed is discharged to the bin BIN2 as an abnormal recording material.

  Next, proceeding to step STEP 107, execution of an image forming operation related to abnormality detection is started. That is, re-execution of the image forming operation for the image IM2 is started. Following this, image forming operations for the subsequent images IM3 and IM4 are started in this order (step STEP109). Then, the above-described flow is executed until the image forming operation for all the images IM1 to IM4 is completed. Note that the operation example shown in FIG. 16 corresponds to the case where no abnormality is detected in the image forming operation after the re-execution of the image forming operation related to the image IM2. As a result of the above operation, as shown in the column “BIN1” in FIG. 16, the four sheets ST on which the images IM1 to IM4 are normally formed are discharged to the bin BIN1 in the order of the images IM1 to IM4. .

  As described above, in the above-described embodiment, the image forming operation (image forming process) for forming an image on the sheet ST (recording material) is executed, and an abnormality in the image forming operation is detected (step STEP102). While the abnormality is not detected, the sheet ST on which the image is formed is discharged to the bin BIN1 (normal discharge tray) (step STEP103). On the other hand, if the abnormality is detected, the image is normally displayed due to the abnormality. The sheet ST on which no is formed is discharged as an abnormal recording material into a bin BIN2 different from the bin BIN1 (step STEP104). Therefore, as shown in the column “BIN1” in FIGS. 15 and 16, a sheet ST on which an image is normally formed and a sheet ST (abnormal recording material) on which an image is not normally formed are in bin BIN1. Occurrence of the problem of mixing is suppressed. Therefore, it is preferable that the troublesome operation of the operator of separating and removing the abnormal recording material is suppressed.

  Further, in the above embodiment, when an abnormality is detected, the image forming operation is re-executed for the image corresponding to the abnormal recording material (step STEP 107). In other words, in the above-described embodiment, when an abnormality is detected, the image corresponding to the abnormal recording material is automatically re-formed. Therefore, in order to form an image that has not been normally formed on the sheet ST (recording material) again, it is possible to reduce the necessity for the operator to stop the image forming operation that is continuously executed halfway. Therefore, it is preferable that the image forming operation can be continuously executed regardless of the occurrence of the abnormality, and the trouble of the operator is suppressed.

  Further, in the above-described embodiment, the CPU 101 determines that the supply start subsequent image in which the supply of the corresponding sheet ST is started among the subsequent images scheduled to be formed after the image corresponding to the image forming operation in which the abnormality is detected. It is judged whether or not it exists. Based on the result of the determination, the bin BIN to which the sheet ST for the supply start subsequent image is discharged is selected.

  More specifically, when it is determined that there is a supply start subsequent image, the sheet ST (recording material) on which an image is formed by the image forming operation in which an abnormality is detected and the sheet ST (recording material) for the supply start subsequent image Are discharged as an abnormal recording material into a bin BIN2 different from the bin BIN1 (normal discharge tray) (steps STEP104, STEP305, and STEP306). Then, the printer 1 is configured to execute the image forming operation for the subsequent image following the re-execution of the image forming operation in which the abnormality is detected (steps STEP107 and STEP108). Therefore, in the above-described embodiment, it is possible to suppress the occurrence of the problem before and after the discharge order of the sheets ST (recording material) regardless of the abnormality of the image forming operation, which is preferable.

  By the way, when a plurality of sheets ST (recording materials) each having the same image are continuously discharged, or when a plurality of direct mails having different destinations are printed in a variable manner, the sheets ST are discharged. There is no problem before and after the order. Therefore, next, an image forming operation executed on the premise that “the discharge order of the sheets ST on which the images IM1 to IM4 are formed does not matter” will be described.

  FIG. 17 is a flowchart illustrating still another example of the control of the image forming operation. FIG. 18 is a diagram showing an example of specific operations executed in the flow of FIG. FIG. 18 shows a case where four images IM1 to IM4 are formed on different sheets ST. The flow shown in FIG. 17 and the flow shown in FIG. 14 are provided with step STEP 401 for determining whether or not the discharge order of the sheets ST can be changed after it is determined “YES” in step STEP 305. The difference is that the following steps STEP402 and STEP403 are provided. Regarding other points, the flow shown in FIG. 17 and the flow shown in FIG. 14 are the same. Therefore, below, it demonstrates focusing on a different part.

  When the image signal is given to the main controller 11, the CPU 101 controls each part of the engine unit EG and starts an image forming operation (step STEP101). When the image forming operation is started, the CPU 101 (detecting means) monitors whether an abnormality is detected (step STEP102). While no abnormality is detected, the sheet ST on which the image is formed by the image forming operation is conveyed to the multi-bin unit 3 and discharged to the bin BIN1 (normal discharge tray) (step STEP103). In the operation example shown in FIG. 18, no abnormality is detected in the image forming operation of the first image IM1, and the sheet ST on which the image IM1 is formed is discharged from the printer 1 to the bin BIN1. If it is determined in step STEP102 that an abnormality has been detected, the sheet ST on which an image has been formed by the image forming operation relating to the abnormality detection is discharged as an abnormal recording material to the bin BIN2 (step STEP104). In the operation example shown in FIG. 18, the CPU 101 determines that an abnormality is detected during the image forming operation related to the image IM2, and as a result, the sheet ST on which the image IM2 is formed is discharged from the printer 1 to the bin BIN2. The That is, in the operation example shown in FIG. 18, the CPU 101 determines that the image IM2 is not normally formed on the sheet ST due to the detected abnormality, and uses the sheet ST on which the image IM2 is formed as an abnormal recording material. The paper is discharged to a bin BIN2 different from the bin BIN1.

  When an abnormality is detected, the sheet ST is supplied to the subsequent images (images IM3 and IM4) that are to be formed after the image (image IM2) corresponding to the image forming operation in which the abnormality is detected. CPU 101 (supply start determining means) determines whether or not the sheet ST (recording material) has been started to be fed in the discharge direction D5 by the feed rollers 851 and 852 (i.e., whether or not feeding has started). Step STEP305). If “YES” is determined in step STEP 305, the process proceeds to step STEP 401, and the CPU 101 refers to replacement information indicating whether or not the discharge order can be switched. Note that the operation example shown in FIG. 18 corresponds to a case where it is determined that the supply of the sheet ST to the subsequent image IM3 is started. That is, the subsequent image IM3 is a supply start subsequent image. Such replacement information is information indicating whether or not the discharge order can be changed when a plurality of sheets on which images are formed are discharged continuously. The replacement information is set in the RAM 107 of the engine controller 10 by the operator via the display unit 12. Specifically, when the operator is not concerned with the discharge order, the operator inputs to the display unit 12 that the discharge order can be changed. The replacement information input to the display unit 12 is set in the RAM 107 (setting unit) via the CPU 111 and CPU 101.

  If it is determined in step S401 that the discharge order can be changed, the image forming operation for the supply start subsequent image IM3 is started (step STEP402), and then the image IM2 related to abnormality detection is detected. Re-execution of the image forming operation is started (step STEP403). At this time, the supply start subsequent image IM3 is subjected to image formation on the sheet determined to be supplied by the supply start determination unit. Note that the operation shown in FIG. 18 corresponds to the case where “YES” is determined in step STEP 305 after “YES” is determined in step STEP 305. As a result, as indicated by the column “BIN1” in FIG. 9, the discharge order of the sheet ST on which the image IM2 is formed and the sheet ST on which the image IM3 is formed into the bin BIN1 is reversed.

  If “NO” is determined in step STEP 401 (that is, it is impossible to change the discharge order), the process proceeds to step STEP 306 and the same operation as that of the embodiment described above is executed. The operation example shown in FIG. 18 corresponds to a case where no abnormality is detected in the image forming operation after the execution of the image forming operation related to the image IM3. As a result of the above operation, as shown in the column “BIN1” in FIG. 18, the four sheets ST on which the images IM1 to IM4 are normally formed are discharged to the bin BIN1.

  In this way, in the embodiment shown in FIGS. 17 and 18, the sheet ST on which the image IM2 is formed by the image forming operation in which the abnormality is detected is discharged to the bin BIN2 different from the bin BIN1. Therefore, it is preferable that only the sheet ST on which an image is normally formed is discharged to the bin BIN1.

  If an abnormality is detected, the image forming operation is performed again for the image IM2 corresponding to the abnormal recording material (step STEP403). That is, in the above-described embodiment, in response to detection of an abnormality, the image IM2 corresponding to the abnormal recording material is automatically re-formed. Therefore, in order to form an image that has not been normally formed on the sheet ST (recording material) again, it is possible to reduce the necessity for the operator to stop the image forming operation that is continuously executed halfway. Therefore, it is preferable that the image forming operation can be continuously executed regardless of the occurrence of the abnormality, and the trouble of the operator is suppressed.

  In the above embodiment, when it is determined that the discharge order can be changed with reference to the replacement information set in the RAM 107, the supply start subsequent image is formed on the sheet ST that has already been supplied. (Step STEP 402), the image forming operation in which an abnormality is detected is re-executed. In other words, by performing the image forming operation with reference to the replacement information, for example, the supply is started before the re-execution of the image forming operation associated with the abnormality detection as described above in order to adjust the discharge order. It is not necessary to execute an operation such as discharging the sheet ST to the bin BIN2 different from the bin BIN1, and the operation can be simplified.

  As described above, in the above-described embodiment, a portion of the printer 1 excluding the cassette 8, the manual feed tray 8h, and the feed rollers 851 and 852 (recording material supply unit) functions as the “image forming unit” of the invention. . Further, the multi-bin unit 3 functions as the “discharge means” of the present invention. That is, the printer 1 and the multi-bin unit 3 function as the image forming apparatus of the present invention. The bins BIN1 to BIN10 of the multi-bin unit 3 function as the “discharge tray portion” of the present invention. The pre-feed sheet detection sensor 804 and the CPU 101 function as the “detection unit” of the present invention. Further, the double feed detection sensor S81 and the CPU 101 function as the “detection means” of the present invention. Further, the skew detection sensor S82 and the CPU 101 function as the “detection means” of the present invention. Further, the horizontal synchronization sensor 601 and the CPU 101 function as “detecting means” of the present invention. Further, the CPU 101 functions as a “conveyance start determination unit” of the present invention.

  The present invention is not limited to the above-described embodiment, and various modifications other than those described above can be made without departing from the spirit of the present invention. For example, in the above-described embodiment, the plurality of bins BIN1 to 10 of the multi-bin unit 3 are functioned as “discharge tray units”, but the configuration of the “discharge tray unit” is not limited to this. That is, when using a printer having a plurality of discharge trays that can discharge the sheet ST, the plurality of discharge trays of the printer itself can function as the “discharge tray unit” of the present invention. In other words, by causing a plurality of discharge trays to function as the “discharge tray unit” of the present invention, a printer having a plurality of discharge trays can be functioned as the “image forming apparatus” of the present invention without providing the multi-bin unit 3. Also good.

  In the above embodiment, in step STEP102, the CPU 101 monitors whether or not four abnormalities of polygon mirror operation abnormality, size abnormality, double feeding, and skew are detected. However, it is not always necessary to monitor the detection of all these abnormalities, and the CPU 101 can also be configured to selectively monitor only those abnormalities that have a large effect on the image among the plurality of abnormalities.

  Further, the abnormality that occurs in the image forming operation executed by the image forming apparatus is not limited to the above four abnormalities, and various other abnormalities may occur. Therefore, the CPU 101 may be configured to provide detection means for detecting an abnormality other than the above four abnormalities and to monitor whether or not the detection result of the detection means is detected in step STEP102.

  In the operation example using FIG. 11, the case where there is one transfer start subsequent image (only the image IM3) has been described, but the number of transfer start subsequent images that can be generated is not limited to this, and two or more transfer start subsequent images are generated. There is also. Even in such a case, the present invention can be applied. That is, in step STEP 106, subsequent to discharging all sheets ST for the conveyance start subsequent image as an abnormal recording material, subsequent steps STEP 107 and STEP 108 may be executed.

  In the operation example using FIG. 13, the case where there is one transfer start subsequent image (only the image IM3) has been described, but the number of transfer start subsequent images that can be generated is not limited to this, and two or more transfer start subsequent images are generated. There is also. Even in such a case, the present invention can be applied. That is, in step STEP202, subsequent steps may be executed following the start of the image forming operation for all images following the start of conveyance.

  In the operation example using FIG. 16, the case where there is one supply start subsequent image (only the image IM3) has been described. However, the number of supply start subsequent images that can be generated is not limited to this, and two or more images are generated. There is also. Even in such a case, the present invention can be applied. That is, in step STEP 306, after discharging all sheets ST for the supply start subsequent image as an abnormal recording material, subsequent steps STEP 107 and STEP 108 may be executed.

  Further, in the operation example using FIG. 18, the case where there is one supply start subsequent image (only the image IM3) has been described. However, the number of supply start subsequent images that can be generated is not limited to this, and two or more images are generated. There is also. Even in such a case, the present invention can be applied. That is, in step STEP402, after the image forming operation is started for all the supply start subsequent images, the subsequent steps may be executed.

  In the above embodiment, the bin BIN1 is used as the normal discharge tray. However, it is needless to say that bins BIN2 to BIN10 other than the bin BIN1 can be used as the normal discharge tray.

  In the above embodiment, the case where the present invention is applied to a so-called rotary type printer has been described. However, the types of printers to which the present invention can be applied are not limited to this, and for example, to a so-called tandem type printer. The present invention can also be applied.

1 is a diagram illustrating an embodiment of a printer that can be used in the present invention. FIG. 2 is a block diagram showing an electrical configuration of the printer of FIG. 1. The figure which shows the structure of the periphery of a gate roller. Explanatory drawing of skew detection. Explanatory drawing of a state without skew. Explanatory drawing of a state with skew. The figure which shows the structure of a multi-bin unit typically. The figure which shows the electrical structure which controls the multi-bin unit shown in FIG. 5 is a flowchart illustrating an example of control of an image forming operation. The figure which shows an example of the specific operation | movement performed in the flow of FIG. The figure which shows another example of the specific operation | movement performed in the flow of FIG. 10 is a flowchart illustrating another example of control of an image forming operation. The figure which shows an example of the specific operation | movement performed in the flow of FIG. 10 is a flowchart illustrating another example of control of an image forming operation. The figure which shows an example of the specific operation | movement performed in the flow of FIG. The figure which shows another example of the specific operation | movement performed in the flow of FIG. 10 is a flowchart illustrating still another example of control of an image forming operation. The figure which shows an example of the specific operation | movement performed in the flow of FIG.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Printer (image forming means, image forming apparatus), 3 ... Multibin unit (discharge means, image forming apparatus), 31 ... Multibin unit controller, BIN1 to BIN10 ... Bin (discharge tray section), 601 ... Horizontal synchronization sensor 804 ... Sheet detection sensor (detection means) before feeding, S81 ... Double feed detection sensor, S82 ... Skew detection sensor, SP ... Stop position, ST ... Sheet (recording material), TR2 ... Secondary transfer area (transfer area), 101 ... CPU (detection means)

Claims (9)

An image forming means for performing an image forming operation for forming an image on a recording material and transporting the recording material in a discharge direction;
A discharge tray portion having a plurality of discharge trays that are provided at different positions on the discharge direction side of the image forming unit and receive the recording material on which the image is formed by the image forming operation;
A discharge that is disposed between the image forming unit and the discharge tray unit and selectively discharges the recording material conveyed from the image forming unit in the discharge direction to one of the plurality of discharge trays. Means,
Detecting means for detecting whether an abnormality has occurred in the image forming operation,
The discharge means discharges the recording material on which the image is formed to a normal discharge tray among the plurality of discharge trays while the abnormality is not detected by the detection means. Is detected, the recording material on which the image is not normally formed due to the abnormality is discharged as an abnormal recording material to the discharge tray different from the normal discharge tray,
The image forming apparatus, when the abnormality is detected by the detection unit, re-executes the image forming operation for the image corresponding to the abnormal recording material. The discharge unit discharges the recording material on which the image is formed by the image forming operation in which the abnormality is detected by the detection unit to the discharge tray different from the normal discharge tray as the abnormal recording material. And
The image forming apparatus according to claim 1, wherein when the abnormality is detected by the detection unit, the image forming unit re-executes an image forming operation related to abnormality detection. A transport start determination unit;
The image forming unit conveys the formed image to a transfer area, and a recording material conveyance that conveys the recording material from a stop position upstream in the discharge direction to the transfer area with respect to the transfer area. And a transfer for transferring the recording material in the discharge direction after transferring the image conveyed by the image conveying unit to the recording material conveyed by the recording material conveying unit in the transfer area. And
The recording material transport unit transports the recording material from the stop position to the transfer region in synchronization with transport of the image to the transfer region by the image transport unit,
When the abnormality is detected by the detection unit, the conveyance start determination unit corresponds to the recording corresponding to the subsequent image scheduled to be formed after the image corresponding to the image forming operation in which the abnormality is detected. Determining whether there is a subsequent image of transport starting from the stop position of the material,
The image forming apparatus according to claim 2, wherein the discharge unit selects which of the plurality of discharge trays discharges the recording material for the conveyance start subsequent image based on a determination result of the transfer start determination unit. . When the transport start determining means determines that the transport start subsequent image is present,
The paper discharge means includes all of the recording material on which the image is formed by the image forming operation in which the abnormality is detected by the detection means and the recording material for the conveyance start subsequent image as the abnormal recording material. Discharge to the discharge tray different from the normal discharge tray,
The image forming apparatus according to claim 3, wherein the image forming unit performs the image forming operation on the subsequent image subsequent to re-execution of the image forming operation in which the abnormality is detected. A setting unit configured to set replacement information indicating whether or not the discharge order can be changed when a plurality of the recording materials on which the image is formed are continuously discharged to the discharge tray;
When the transport start determining means determines that the transport start subsequent image is present and the replacement information indicates that the replacement is possible,
The paper discharge means uses the recording material on which the image has been formed by the image forming operation in which the abnormality is detected by the detection means as the abnormal recording material to the discharge tray different from the normal discharge tray. Discharge,
The image forming unit detects the abnormality after the conveyance start subsequent image is formed on the recording material that the conveyance start determination unit determines to have started conveyance from the stop position. The image forming apparatus according to claim 3, wherein the forming operation is re-executed. Recording material supply means for supplying the recording material to the image forming means;
A supply start determination means;
When the abnormality is detected by the detection unit, the supply start determination unit corresponds to the recording corresponding to the subsequent image that is to be formed after the image corresponding to the image forming operation in which the abnormality is detected. Determining whether there is a supply start succeeding image in which supply by the recording material supply means of the material has started,
The image forming apparatus according to claim 2, wherein the discharge unit selects which of the plurality of discharge trays discharges the recording material for the supply start subsequent image based on a determination result of the supply start determination unit. . When the supply start determination means determines that the supply start subsequent image is present,
The paper discharge means includes all of the recording material on which the image is formed by the image forming operation in which the abnormality is detected by the detection means and the recording material for the supply start subsequent image as the abnormal recording material. Discharge to the discharge tray different from the normal discharge tray,
The image forming apparatus according to claim 6, wherein the image forming unit performs the image forming operation on the subsequent image subsequent to re-execution of the image forming operation in which the abnormality is detected. A setting unit configured to set replacement information indicating whether or not the discharge order can be changed when a plurality of the recording materials on which the image is formed are continuously discharged to the discharge tray;
When the supply start determination means determines that the supply start subsequent image is present and the replacement information indicates that the replacement is possible,
The paper discharge means uses the recording material on which the image has been formed by the image forming operation in which the abnormality is detected by the detection means as the abnormal recording material to the discharge tray different from the normal discharge tray. Discharge,
The image forming means detects the abnormality after the supply start determination means forms the supply start succeeding image on the recording material determined to be supplied by the recording material supply means. The image forming apparatus according to claim 6, wherein the image forming operation is re-executed. An image forming process for executing an image forming process for forming an image on a recording material;
A detection step of detecting an abnormality in the image forming process;
While the abnormality is not detected by the detection step, the recording material on which the image is formed is discharged to a normal discharge tray out of a plurality of discharge trays, while when the abnormality is detected by the detection step, A discharge step of discharging the recording material on which the image is not normally formed due to the abnormality as an abnormal recording material to the discharge tray different from the normal discharge tray;
The image forming method, wherein when the abnormality is detected by the detecting step, the image forming process is re-executed for the image corresponding to the abnormal recording material.

Images