JP2013064851A - Image forming apparatus, control method, and control program - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image forming apparatus which is capable of improving the productivity in printing after recovery from a jam (paper jam).SOLUTION: A conveyance path of a printer branches into an upper path and a lower path for ejecting each conveyed recording sheet to a sheet ejection tray, in the downstream side of a location provided with a secondary transfer roller and a fixing roller in the conveyance direction. When a jam is detected in the lower path (#1), a recording sheet following the recording sheet of the jam object and having a page succeeding the jam object page normally printed is conveyed to the upper path and is temporarily waited (#2). At a time of recovery printing, the jam object page is printed and ejected, and at a predetermined timing after the sheet of the page has reached to the upper path, the evacuated recording sheet is ejected from the lower path.

Description

  The present invention relates to an image forming apparatus, a control method, and a control program, and more particularly to an image forming apparatus provided with a plurality of paths for eliminating paper, a control method for the image forming apparatus, and a control program for the image forming apparatus.

  When a jam (paper jam) occurs during printing, printing is interrupted for a sheet upstream of the conveyance path from the jammed sheet. These sheets are removed and discarded during the jam processing by the operator.

  When printing after jam recovery, in order to print in page order, all the paper upstream from the jammed paper needs to be printed again, so the paper upstream from the jammed paper is printed normally. Nevertheless, it was discarded and wasted paper.

  In order to solve this problem, Japanese Patent Laid-Open No. 9-258516 (hereinafter referred to as “Patent Document 1”) discloses a method of storing a succeeding printed sheet in an intermediate tray when a jam occurs, and retracting the sheet to the intermediate tray after the jam is released. Discloses a technology for feeding and conveying the images so that the page order matches.

Japanese Patent Laid-Open No. 9-258516

  However, in the technique disclosed in Patent Document 1, in order to keep the page order, it is necessary to insert the paper that has been temporarily retracted into the intermediate tray after printing the paper to be recovered. That is, in printing after recovery, it is necessary to convey and discharge the jam target paper, the paper retracted to the intermediate tray, and the subsequent paper in this order.

  As a result, even if there is paper already fed when a jam occurs, the next page of the jammed page must be transported again on the transport path in the same way as printing. There is a problem that the productivity is reduced by the amount of the product that is transported along the transport route.

  The present invention has been made in view of such a problem, and provides an image forming apparatus, a control method, and a control program capable of improving productivity in printing after recovery from a jam (paper jam). It is intended to provide.

  In order to achieve the above object, according to one aspect of the present invention, the image forming apparatus is provided facing the conveyance path while conveying the recording paper in the conveyance path continuing from the paper feeding unit to the paper discharge unit. An image forming apparatus that prints an image on recording paper by an image forming unit, and discharges the printed recording paper to a paper discharge unit. The image forming unit is downstream from the position where the image forming unit is disposed from the transport path in the transport direction. For switching two or more discharge paths for discharging the transported recording sheets to the discharge section and the transport destination from the transport path to each of the two or more discharge paths. The first switching means, the detection means for detecting the arrival of the recording paper to the paper discharge path, and the jam of each of the two or more paper discharge paths. Detection means for detecting occurrence and conveyance of recording paper in the conveyance path And a control means for controlling switching of the conveying path of the first switching means, the conveyance of the recording sheet in two or more discharge path, respectively. When the control unit detects the occurrence of a jam in any of the two or more paper discharge paths, the control unit normally prints a page following the jam target page, which is a recording sheet following the jam target recording sheet. Control to stop the recording paper in one of the two or more paper discharge paths different from the paper discharge path where the jam has occurred, and stop the paper in the paper discharge path, and print after the occurrence of the jam. When the operation is resumed, the jammed page is printed and discharged to the paper discharge unit via the paper discharge path where the jam has occurred, and the recording paper on which the jammed page is printed is jammed. At a predetermined timing after reaching the generated paper discharge path, the recording paper once stopped in the paper discharge path different from the paper discharge path where the jam occurred is transferred to the paper discharge unit via the paper discharge path. Control to discharge the sheet is executed.

  Preferably, the predetermined timing is such that the page to be jammed is printed before the recording paper temporarily stopped in the paper discharge path different from the paper discharge path in which the jam has occurred is discharged to the paper discharge unit. This is the timing at which the discharge from the paper discharge path where the jammed recording paper has occurred is completed.

  Preferably, the control means conveys a recording sheet on which a page subsequent to the jammed page following the jammed recording sheet is normally printed, to a paper ejection path different from the paper ejection path where the jam occurred. In the control for stopping the recording paper, the leading edge in the conveyance direction of the recording paper is stopped at a position from the paper discharge path where the jam has occurred to a position where it does not contact the recording paper to be discharged.

  Preferably, the paper discharge path different from the paper discharge path where the jam has occurred is provided with a second switching means for switching the transport direction to the transport direction in the transport path and transporting to a path different from the transport path. The control means transports the paper in the paper discharge path when the length in the transport direction in the transport path of the recording paper on which the page after the page to be jammed is normally printed is longer than a predetermined length. The direction is switched, and the trailing edge of the recording sheet is temporarily stopped in a path different from the transport path in the transport direction of the transport path.

  Preferably, the conveyance of the recording paper on which the page to be jammed is printed by the printing operation resumed after the occurrence of the jam and the recording paper once stopped in the paper ejection path different from the paper ejection path where the jam occurs. When the lengths of the directions are different, the predetermined timing is that both the recording paper on which the jammed page is printed and the recording paper temporarily stopped in the paper discharge path different from the paper discharge path where the jam has occurred Is the timing at which the rear end in the transport direction is discharged to the paper discharge unit at the same time.

  Preferably, the distance from the paper discharge path different from the paper discharge path where the jam occurs to the paper discharge unit is longer than the distance from the paper discharge path where the jam occurs to the paper discharge unit, and the control unit When recording paper that has been stopped in a paper discharge path different from the paper discharge path is discharged to the paper discharge unit via the paper discharge path, the page to be jammed is printed and the recording paper is jammed. The sheet is conveyed at a speed slower than the conveying speed when the sheet is discharged via the sheet discharge path in which the error occurs.

  More preferably, the control means sets the jam when the length in the transport direction of the recording paper once stopped in a paper discharge path different from the paper discharge path where the jam has occurred is shorter than a predetermined length. The target page is printed and the recording paper is transported at a speed slower than the transport speed when paper is ejected via the paper ejection path where the jam has occurred.

  According to another aspect of the present invention, the control method conveys an image on a recording sheet by an image forming unit provided facing the conveyance path while conveying the recording sheet in a conveyance path that continues from the paper feeding unit to the paper discharge unit. Is a control method of an image forming apparatus that prints the printed recording paper to a paper discharge unit, and the transport path is transported downstream in the transport direction from the position where the image forming unit is disposed. Branching into two or more paper discharge paths for discharging the recorded recording paper to the paper discharge unit, detecting the occurrence of a jam in one of the two or more paper discharge paths, and a target of the jam The recording paper that follows this recording paper, and on which the pages after the page to be jammed are printed normally, is discharged from a paper discharge path different from the paper discharge path where the jam occurred. Conveying to the paper path and temporarily stopping in the paper discharge path; When the printing operation is resumed after a jam occurs, printing the jam target page and discharging it to the paper discharge unit via the paper discharge path where the jam occurred, and printing the jam target page The recording paper that has been stopped in the paper discharge path different from the paper discharge path where the jam occurred is passed through the paper discharge path at a predetermined timing after the paper reaches the paper discharge path where the paper jam occurred. And a step of discharging the paper to the paper discharge unit.

  According to still another aspect of the present invention, the control program transfers the recording paper in the conveyance path that continues from the paper feeding unit to the paper discharge unit, and applies the recording paper to the recording paper by the image forming unit provided facing the conveyance path. A control program for controlling an operation at the time of printing after a jam occurs in an image forming apparatus that prints an image and discharges the printed recording paper to a paper discharge unit. Branches downstream of the position at which the means is disposed in the transport direction into two or more paper discharge paths for discharging the transported recording paper to the paper discharge unit. A step of detecting the occurrence of a jam in any one of the above, and a recording paper subsequent to the jammed recording paper on which the pages following the jammed page are normally printed are discharged in two or more. Out of paper path, jammed paper output path Are transported to a different paper discharge path, temporarily stopped in the paper discharge path, and when the printing operation is resumed after a jam occurs, the jammed paper is printed by printing the target page of the jam. And a step of causing the paper discharge unit to discharge the paper, and a jammed paper discharge path at a predetermined timing after the recording paper on which the jammed page is printed reaches the paper discharge path where the paper jam occurred. Causes the image forming apparatus to execute a step of discharging the recording paper once stopped in a different paper discharge path to the paper discharge unit via the paper discharge path.

  According to the present invention, it is possible to improve productivity in printing after recovery from a jam (paper jam).

1 is a diagram illustrating a specific example of a configuration of a printer as an image forming apparatus according to an embodiment. FIG. 4 is a diagram for explaining a configuration of a conveyance path of the printer according to the embodiment. 2 is a block diagram illustrating a configuration of a control unit of the printer according to the embodiment. FIG. FIG. 10 is a diagram illustrating an operation of the printer according to the embodiment when a jam occurs at a discharge position of a lower path while discharging a sheet to a discharge tray. It is a figure showing the operation | movement at the time of the recovery printing operation | movement after jam. It is a figure showing the operation | movement at the time of the recovery printing operation | movement after jam. FIG. 10 is a diagram illustrating an operation in a printer when a jam occurs at a discharge position in a lower path while discharging a sheet to a discharge tray. 6 is a flowchart showing an operation flow for retreating a sheet already printed when a jam occurs in the printer according to the embodiment to the upper discharge path. 6 is a flowchart illustrating an operation flow during a recovery printing operation from a jam in the printer according to the embodiment. It is a figure for demonstrating normal paper discharge timing. FIG. 6 is a diagram for explaining a paper discharge timing in the printer according to the embodiment.

  Embodiments of the present invention will be described below with reference to the drawings. In the following description, the same parts and components are denoted by the same reference numerals. Their names and functions are also the same.

<Device configuration>
FIG. 1 is a diagram illustrating a specific example of a configuration of a printer 1 as an image forming apparatus according to the present embodiment.

Here, it is assumed that the printer 1 is a tandem type color printer.
Referring to FIG. 1, as an example, the printer 1 has a configuration in which a paper feed unit 200 is disposed below the main body, a color image forming unit 100 is disposed at the center, and a paper discharge unit 600 is disposed above. In addition, a control unit 400 for performing overall control is included in the main body. In addition, an operation panel 500 is provided outside thereof.

  A conveyance path 206 for conveying the sheet S fed from the sheet feeding unit 200 vertically upward is provided from the sheet feeding unit 200 to the sheet discharge unit 600. The paper feed unit 200 side of the conveyance path 206 is referred to as an “upstream” side, and the paper discharge unit 600 side is referred to as a “downstream” side.

  An intermediate transfer belt 30 that is horizontally supported by a driving roller 40 and a driven roller 50 is disposed in the center of the color image forming unit 100. The intermediate transfer belt 30 is rotated by these rollers 40 and 50, and image forming units for each color of yellow (Y), magenta (M), cyan (C), and black (K) along the running direction indicated by the arrows in the drawing. (Imaging unit) 10Y, 10M, 10C, 10B are arranged.

  The toner images created by the image forming units 10Y, 10M, 10C, and 10B are superimposed and transferred onto the intermediate transfer belt 30. This transfer is called primary transfer.

  The toner image on the intermediate transfer belt 30 is transferred to the sheet S conveyed on the conveyance path 206 at the conveyance end (right end in the drawing) of the intermediate transfer belt 30. This transfer is called secondary transfer.

  A fixing unit 300 is disposed on the downstream side of the conveyance path 206 from a position in contact with the conveyance end of the intermediate transfer belt 30.

  The sheet S to which the toner image is transferred is fed to the fixing unit 300, and the toner image is fixed to the sheet S by the fixing unit 300.

  Image forming units 10Y, 10M, 10C, and 10B form toner images by electrostatic copying. Therefore, the image forming units 10Y, 10M, 10C, and 10B each include a charger and a developer. Further, around the image forming units 10Y, 10M, 10C, and 10B, a print head 21 including a laser diode corresponding to each color, a polygon mirror, a scanning lens, and the like, and four reflection mirrors 22 corresponding to each color are provided. An exposure unit 20 and a transfer device are arranged.

  Further, as a replenishment mechanism for replenishing toner to the developing units of the image forming units 10Y, 10M, 10C, and 10B, the toner cartridges 70Y, 70M, 70C, and 70B and the sub hoppers 80Y, 80M, 80C, and 80B are provided for the respective image forming units 10Y. , 10M, 10C, 10B.

FIG. 2 is a diagram for explaining the configuration of the transport path 206 of the printer 1.
Referring to FIG. 2, a plurality of roller pairs are arranged on conveyance path 206, and each roller pair is electrically connected to a motor (not shown) and rotated by driving thereof. The motor is electrically connected to the control unit 400, and its driving is controlled by the control unit 400.

  Specifically, a first-stage sheet feeding roller is disposed in the uppermost stream in the vicinity of a sheet feeding tray (not shown) in the sheet feeding unit 200 of the conveyance path 206, and a registration roller is disposed on the downstream side of the first-stage sheet feeding roller.

  By rotating the first-stage sheet feeding roller, the sheet is supplied from the sheet feeding tray to the conveying path 206 and is conveyed to the registration roller. The conveyed sheet stops by abutting the leading edge against the stopped registration roller.

  A secondary transfer roller is disposed downstream of the registration roller. The secondary transfer roller is paired with a drive roller 40 that supports the intermediate transfer belt 30.

  Under the control of the control unit 400, the registration roller rotates at a timing synchronized with the image transfer, and the sheet is conveyed to the secondary transfer roller position.

  The sheet conveyed to the secondary transfer roller position is pressed against the intermediate transfer belt 30 by a pair with the driving roller 40, and the toner image transferred onto the intermediate transfer belt 30 is transferred.

  A fixing roller provided in the fixing unit 300 is disposed downstream of the secondary transfer roller. The paper on which the toner image is transferred by the driving roller 40 and the secondary transfer roller is further conveyed to the fixing roller position, and the toner image is fixed on the paper by passing through the fixing roller.

  A pre-discharge roller and a discharge roller are arranged downstream of the fixing roller. Further, when the printer 1 is an apparatus having an automatic duplex unit (ADU) for duplex printing, as shown in the drawing, a discharge reversing roller for transporting paper to the ADU is provided downstream of the fixing roller. Arranged.

  In the following description, the path from the fixing roller through the pre-discharge roller to the paper discharge roller is referred to as “lower path”, and the path from the fixing roller through the pre-discharge roller to the paper discharge reverse roller is referred to as “upper path”. Is also referred to.

  The printed paper is conveyed to the paper discharge roller or the paper discharge reverse roller, and is output to the paper discharge tray 601.

  A switching claw is provided at a branch point between the conveyance path to the paper discharge roller and the conveyance path to the paper discharge reversing roller. By switching the switching claw under the control of the control unit 400, the transport destination of the printed paper is switched between the upper path and the lower path.

  When performing double-sided printing, the switching claw is switched under the control of the control unit 400, so that the sheet is conveyed to the paper discharge reversing roller along the upper path. The paper discharge reversing roller switches (switches back) the rotation direction during conveyance according to the control of the control unit 400 and conveys the conveyed paper to the ADU.

  Within the ADF, a plurality of pairs of ADF transport rollers are arranged along the transport path, and the paper is transported by these rotations and transported again to the roller pair of the drive roller 40 and the secondary transfer roller. The As a result, the toner image is fixed on the back side.

  A sensor for detecting (ON) that a sheet is present at the position is arranged at each position on the transport path. That is, referring to the drawing, a first-stage sheet feeding sensor is provided immediately downstream of the first-stage sheet feeding roller, and sheet feeding from the sheet feeding tray is detected. In addition, a registration sensor is provided immediately upstream of the registration roller, and detects paper feeding to the registration roller position. In addition, a fixing loop sensor is provided between the secondary transfer roller and the fixing roller, and a paper loop (sag) at the position is detected. A paper discharge sensor is provided immediately upstream of the paper discharge roller to detect paper discharge. Further, a paper discharge reversing sensor is provided immediately upstream of the paper discharge reversing roller, and the conveyance of the paper to the ADU is detected.

<Control configuration>
FIG. 3 is a block diagram showing a configuration of control unit 400.

  Referring to FIG. 3, a control unit 400 includes a CPU (Central Processing Unit) 401, a communication interface (I / F) unit 402, an image processing unit 403, an image memory 404, a laser diode driving unit 405, a ROM (Read Only Memory). ) 406, a RAM (Random Access Memory) 407, and an engine control unit 408.

  The communication I / F unit 402 is an interface for connecting to a LAN, such as a LAN (Local Area Network) card or a LAN board. The communication I / F unit 402 receives print job data from the outside and sends the received data to the image processing unit 403. send.

  The image processing unit 403 converts print job data from the communication I / F 402 into YMCK reproduction color image data, outputs the image data to the image memory 404, and stores the image data for each reproduction color.

  The laser diode driver 405 reads out the image data of each color from the image memory 404 and activates the laser diode of the exposure unit 20.

  The ROM 406 stores data such as a table used for warm-up control and fixing control, as well as a table used for control, in addition to a control program related to an image forming operation.

The RAM 407 is used as a work area for the CPU 402.
The CPU 401 reads a necessary program from the ROM 406 and performs image data conversion processing in the image processing unit 403, image data writing / reading in the image memory 404, and the like. Also, the operations of the color image forming unit 100, the paper feeding unit 200, and the like are uniformly controlled while taking a timing to execute a smooth printing operation.

  The engine control unit 408 is electrically connected to sensors and motors of each unit. The engine control unit 408 receives sensor signal input from each sensor and inputs the sensor signal to the CPU 401. And according to the control signal from CPU401, the drive of each motor is controlled.

  The CPU 401 includes a jam detection unit 101 and a drive control unit 102 as functions exhibited by executing a program read from the ROM 406.

  The jam detection unit 101 receives an input of a sensor signal from the engine control unit 408, and detects the occurrence of a jam and the occurrence position of the jam.

  The drive control unit 102 outputs a control signal to the engine control unit 408 so as to control the drive of the motor connected to the roller so as to perform an operation described later according to the jam occurrence position.

<Overview of operation>
An outline of the operation of the printer 1 will be described with reference to FIGS.

  FIG. 4 is a diagram illustrating the operation of the printer 1 when a jam occurs at the discharge position of the lower path while the sheet is being discharged to the discharge tray.

  In the printer 1, when a jam occurs at the discharge position of the lower path with respect to the first page of paper S1, the switching claw is switched, and the second page of paper S2 that has already been printed normally. However, the switching claw is controlled and conveyed to the upper path (# 2). The subsequent sheet S3 of the third page is in the upstream of the sheet S1 in the conveyance path in a state where normal printing is not performed.

  The sheet S2 conveyed to the upper path is stopped at that position, and is temporarily retracted from the conveyance of the sheet on the lower path at the time of printing after recovery. At this time, preferably, the conveyance of the sheet S2 is stopped at a position where the leading edge of the sheet S2 does not contact the sheet discharged from the lower path in the subsequent recovery printing. That is, the leading edge of the sheet S2 extends from the lower path to the parabola toward the discharging tray so that the leading edge of the sheet S2 does not contact the sheet fed toward the discharging tray by gripping and rotating the discharging roller from the lower path. The sheet S2 is retracted at a position where it does not reach.

  In the printer 1, the sheets to be recovered (reprinted) from the jam at this time are the first sheet S <b> 1 and the third sheet S <b> 3. The second page of paper S2 that has already been printed normally is excluded from the paper to be recovered from the jam and is temporarily retracted on the upper path.

  After the user removes the first page of paper S1 and the third page of paper S3, the printer 1 starts the recovery printing operation.

  5 and 6 are diagrams showing the operation at the time of the recovery printing operation at this time. With reference to FIG. 5, in the printer 1, first, a new sheet S1 ′ for printing the first page to be recovered is conveyed to the lower path (# 3), and a predetermined amount is supplied from the rear end of the sheet S1 ′. A gap between the sheets is opened, and a new sheet S3 ′ for printing the third page is continuously conveyed (# 4).

  Next, referring to FIG. 6, after the first page of paper S1 ′ continues to be conveyed and discharged to the paper discharge tray (# 5), a predetermined time has elapsed since the leading edge of the paper discharge sensor turned on. That is, at the same time that the top of the first page of paper S1 ′ is removed from the paper discharge roller, the paper reversing roller is rotated to discharge the second page of paper S2 that has been retreated to the upper path to the paper discharge tray ( # 6). Further, the conveyance of the sheet S3 'of the third page is continued (# 7).

  The predetermined time was retracted between the time when the rear end of the sheet S1 ′, which is recovery paper, passed through the paper discharge roller and the time when the front end of the paper S3 ′ of the third page reached the paper discharge roller. It is assumed that the trailing edge of the sheet S2 can pass through the sheet discharge reverse roller. In other words, it is a time during which the second sheet of paper S2 that has been evacuated is discharged before the first page of paper S1 ′ is discharged and the third page of paper S3 ′ is discharged. .

  As a result, the sheets S1 'and S2 are discharged in this order to the sheet discharge tray, and then the third page sheet S3' conveyed following the first page sheet S1 'is discharged.

  Note that when the sheet S2 of the second page is retracted to the upper path and the sheet S3 is a sheet that is long enough to have its trailing edge positioned upstream from the position of the switching claw, the printer 1 causes the # 2 described above. Thus, during the operation of retracting the second sheet of paper S2 to the upper path, the traveling direction of the paper S2 is switched (switched back) by the discharge reverse roller. FIG. 7 is a diagram showing the operation of the printer 1 at this time.

  Referring to FIG. 7, in this case, after the sheet S2 is conveyed in the sheet discharge direction by rotating the sheet discharge reversing roller until the rear end passes through the branch portion between the main body conveyance path and the ADU conveyance path. (# 2-1), the direction of rotation is reversed, and the transport path of the ADU is transported for a predetermined time with the trailing edge of the sheet S2 as the head and stopped (# 2-2). As a result, the sheet S2 is retracted while being stored in the ADU transport path.

  If the length of the paper S1 that is the jam target paper and the subsequent normally printed paper S2 in the transport direction (sub-scanning direction) are different, in # 6, the recovered paper The rotation of the discharge reversing roller is started at a timing such that the trailing edge of S1 ′ and the trailing edge of the sheet S2 that has been retracted are discharged at the same time.

  This simultaneous period is preferably simultaneous, and may be a period when the trailing edge of the sheet S2 is discharged after a very short time after the trailing edge of the sheet S1 'is discharged.

<Operation flow>
FIG. 8 and FIG. 9 are flowcharts showing the flow of the operation for retracting the paper already printed when a jam occurs to the upper discharge path and the operation during the recovery printing operation from the jam, respectively. 8 and 9 is realized by the CPU 401 executing a program read from the ROM 406 and controlling each unit shown in FIGS.

  Referring to FIG. 8, when a jam is detected in step S101, CPU 401 confirms the occurrence position.

  As a result, if it is detected that a jam has occurred at the discharge position of the lower path and that there is already printed paper upstream from the paper to be jammed (YES in step S103), in step S105 The CPU 401 stops the driving of the motors for the rollers arranged in the lower path. Thereby, the conveyance of the lower path is stopped.

  In step S107, the switching claw is switched and conveyed to the upper path, and then the driving of the motors for the rollers arranged in the upper path is started in step S109. As a result, the already-printed sheet S2 following the jammed sheet S1 is not conveyed to the lower path where the jam has occurred, but is conveyed to the upper path.

  Thereafter, the CPU 401 monitors the position of the sheet S2 being conveyed along the upper path. The conveyance is continued until the sheet reaches a predetermined position. When it is detected that the trailing edge of the sheet S2 has reached the predetermined position (YES in step S111), in step S113, the CPU 401 stops driving the motors for the rollers arranged in the upper path, Stop conveyance of the upper path. As a result, the sheet S2 conveyed to the upper path stops at a predetermined position on the upper path and is retracted.

  FIG. 9 shows the transport operation during the recovery printing operation after the user removes the first page paper S1 to be jammed and the third page paper S3 on the transport path before printing. .

  Referring to FIG. 9, when the recovery printing operation is started and conveyance of a new first page of paper S <b> 1 ′ to be recovered is started, CPU 401 monitors the position. At this time, along with the start of the recovery printing operation, the CPU 401 starts driving the motors for the rollers arranged in the lower path. The conveyance of the lower path is the same as that of normal printing, and the CPU 401 prints on each sheet by repeating rotation / stop of the discharge rollers arranged on the lower path for each sheet. The printed paper is discharged.

  When it is detected that the first page has been printed on the new first sheet S1 ′ and the sheet S1 ′ has reached the paper discharge sensor and a predetermined time has passed (YES in step S201). ) In step S203, the CPU 401 starts driving the motors for the rollers arranged in the upper path. As a result, discharge of the sheet S2 that has been retracted to a predetermined position in the upper path is started immediately after the sheet S1 '.

  The CPU 401 continues the conveyance of the upper path until the discharge of the sheet S2 is completed. When it is detected that the paper S2 has been discharged from the upper path (YES in step S205), in step S207, the CPU 401 stops driving the motors for the rollers arranged in the upper path. Then, the conveyance of the upper path is stopped.

  Note that if the retracted sheet S2 is discharged from the upper path by rotating the discharge reverse roller, the drop distance to the discharge tray is longer than when the sheet S2 is discharged from the lower path, so that the sheet stacking property is deteriorated. . For this reason, preferably, in step S203, the CPU 401 slows the discharge speed of the discharge reversing roller when discharging the sheet S2. That is, the rotational speed of the paper discharge reversing roller is slowed at least during paper discharge. Thereby, it is possible to improve the stackability of the sheet S2, in particular.

  Similarly, when the length of the sheet S2 in the transport direction (sub-scanning direction) is short, the sheet stackability is similarly deteriorated. Therefore, preferably, in step S203, the CPU 401 similarly reduces the discharge speed of the discharge reversing roller even when the length of the sheet S2 in the transport direction (sub-scanning direction) is equal to or less than a predetermined length. As a result, paper stackability can be improved.

  In step S209, the CPU 401 drives the motor for each roller arranged in the lower path to print on the sheet S3 of the subsequent third page, and conveys it to the lower path.

<Effect of Embodiment>
By performing the above-described operation in the printer 1, the paper printed on the paper to be jammed that has already been normally printed at the time of jamming is not discarded. For this reason, it is possible to suppress the consumption of paper accompanying the handling of the jam.

  In addition, after paper that has been printed normally at the time of jam occurrence is evacuated to a transport path that is different from the normal transport path, an appropriate sheet of paper after printing that is discharged through the normal transport path at the time of recovery printing By discharging the sheet at the position, the pages are printed in the order of pages at the time of recovery printing.

  Further, at that time, the printer 1 quickly discharges the sheet withdrawn to another path according to the timing of discharging from the normal path.

  10 and 11 are diagrams for explaining the normal paper discharge timing and the paper discharge timing in the printer 1.

  First, referring to FIG. 10, when a recovery printed sheet is discharged in the normal transport path (lower path), the time T from the start to the end of discharging the sheet S1 ′ reprinted at the time of recovery printing, Rotate the paper roller, and once the paper is discharged, stop the paper roller. After the predetermined time t, the rotation of the paper discharge roller is resumed, the time T from the start of paper discharge to completion, the subsequent paper S2 is discharged, and once the paper discharge is completed, the rotation of the paper discharge roller is stopped. Furthermore, after the predetermined time t, the rotation of the paper discharge roller is resumed and the subsequent paper S3 'is discharged.

  For this reason, in this method, the time required from the start of the discharge of the page to be jammed to the completion of the discharge of the second page is the sum of the respective discharge time (T) and the predetermined time (t). This is a time (2 × T + t).

  On the other hand, referring to FIG. 11, in the case of paper discharge by the printer 1, the paper discharge roller is rotated for a time T from the start of paper discharge to completion of the paper S1 ′ reprinted from the lower path during recovery printing. At the same time, after a predetermined time from the discharge of the sheet S1 ′, which is the timing when the leading edge of the sheet S1 ′ has passed through the discharge roller, the discharge reversing roller is also rotated to discharge the sheet S2 retracted to the upper path. . Then, after the completion of the discharge of the sheet S2, after a predetermined time, the rotation of the discharge roller is resumed and the subsequent sheet S3 'is discharged.

  For this reason, in this method, the discharge of the sheet S1 ′ and the discharge of the sheet S2 are performed in parallel, and it is necessary from the start of the discharge of the page to be jammed until the discharge of the second page is completed. The time is shorter than the time (2 × T + t) required by the method of FIG.

  Therefore, in the printer 1, compared to the method of discharging all from the lower path shown in FIG. 10, the start of discharging the third page can be remarkably accelerated. That is, productivity in recovery printing can be improved.

  In the above description, when a jam occurs in the lower path, the second page sheet S2 following the upper path is retracted, and the first page printed after recovery in the lower path is discharged in accordance with the timing. It is assumed that the sheet S2 retracted to the upper path is discharged.

  However, as another example, even when a jam occurs in the upper path, it is possible to improve the productivity of recovery printing in the same manner by performing the control opposite to the above description. That is, in this case, the normally printed sheet is temporarily retracted in the lower path, and the sheet S2 retracted in the lower path is discharged in accordance with the timing of discharging the first page printed after recovery in the upper path. You may do it.

  Further, in this example, the transport path 206 is branched into two transport paths, an upper path and a lower path, but may be branched into two or more transport paths. Similarly, in this case, the normally printed sheet is temporarily retracted to another path of the transport path where the jam has occurred, and is retracted to another path according to the timing of discharging the first page during recovery printing. The discharged sheet S2 may be discharged.

  Furthermore, in this case, when there are a plurality of pages printed normally as well as the second page, the plurality of pages may be evacuated to each of the other paths. Further, all the plural pages may be saved in one other route. This also applies to the case of branching into two transport routes, an upper route and a lower route.

  Furthermore, a program for causing the printer 1 to execute the above-described operation can be provided. Such a program is recorded on a computer-readable recording medium such as a flexible disk attached to the computer, a CD-ROM (Compact Disk-Read Only Memory), a ROM, a RAM, and a memory card, and provided as a program product. You can also. Alternatively, the program can be provided by being recorded on a recording medium such as a hard disk built in the computer. A program can also be provided by downloading via a network.

  The program according to the present invention is a program module that is provided as a part of a computer operating system (OS) and calls necessary modules in a predetermined arrangement at a predetermined timing to execute processing. Also good. In that case, the program itself does not include the module, and the process is executed in cooperation with the OS. A program that does not include such a module can also be included in the program according to the present invention.

  The program according to the present invention may be provided by being incorporated in a part of another program. Even in this case, the program itself does not include the module included in the other program, and the process is executed in cooperation with the other program. Such a program incorporated in another program can also be included in the program according to the present invention.

  The provided program product is installed in a program storage unit such as a hard disk and executed. The program product includes the program itself and a recording medium on which the program is recorded.

  The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

  DESCRIPTION OF SYMBOLS 1 Printer, 10Y, 10M, 10C, 10B Image forming unit, 20 Exposure part, 21 Print head, 30 Intermediate transfer belt, 40 Driving roller, 50 Driven roller, 70Y, 70M, 70C, 70B Toner cartridge, 80Y, 80M, 80C 80B sub hopper, 100 color image forming unit, 101 jam detecting unit, 102 drive control unit, 200 paper feeding unit, 206 transport path, 300 fixing unit, 400 control unit, 401 CPU, 402 communication I / F unit, 403 image Processing unit, 404 image memory, 405 laser diode driving unit, 406 ROM, 407 RAM, 408 engine control unit, 500 operation panel, 600 paper discharge unit, 601 paper discharge tray, S sheet.

Claims (9)

While the recording paper is being transported in the transport path that continues from the paper feed unit to the paper discharge unit, an image is printed on the recording paper by the image forming means provided facing the transport path, and the printed recording paper is An image forming apparatus for discharging to a paper discharge unit,
Two or more paper discharge paths for discharging the transported recording paper to the paper discharge unit, branched from the transport path downstream in the transport direction from the position where the image forming unit is disposed. When,
First switching means for switching the transport destination from the transport path to each of the two or more paper discharge paths;
A detecting means arranged in each of the two or more paper discharge paths for detecting the arrival of the recording paper to the paper discharge path;
Detecting means for detecting the occurrence of a jam in each of the two or more paper discharge paths;
Control means for controlling conveyance of the recording paper in the conveyance path, switching of the conveyance path in the first switching means, and conveyance of the recording paper in each of the two or more paper discharge paths,
The control means includes
When the occurrence of a jam is detected in any one of the two or more paper discharge paths, a page following the jam target page is printed normally after the jam target recording sheet. Control for conveying the recording paper to a paper discharge path different from the paper discharge path in which the jam occurs among the two or more paper discharge paths, and temporarily stopping the paper in the paper discharge path;
Control that prints the page to be jammed and discharges it to the paper discharge unit via the paper discharge path where the jam has occurred when the printing operation is resumed after the occurrence of the jam;
At a predetermined timing after the recording paper on which the page to be jammed has reached the paper ejection path where the jam occurred, the recording paper is temporarily stopped in a paper ejection path different from the paper ejection path where the jam occurred. An image forming apparatus that executes control for discharging recording paper to the paper discharge unit via the paper discharge path.   At the predetermined timing, the jammed page is printed before the recording paper once stopped in the paper discharge path different from the paper discharge path in which the jam has occurred is discharged to the paper discharge unit. The image forming apparatus according to claim 1, wherein the discharge timing of the recorded paper from the paper discharge path where the jam has occurred is completed.   The control means conveys a recording sheet on which a page following the jam target page has been normally printed following the jam target recording sheet to a discharge path different from the discharge path where the jam has occurred. 3. The control according to claim 1, wherein in the control for stopping the recording paper, the leading edge in the conveyance direction of the recording paper is stopped at a position from the paper discharge path where the jam occurs to a position where the recording paper is not in contact with the paper. Image forming apparatus. The paper discharge path different from the paper discharge path where the jam has occurred is provided with a second switching means for switching the transport direction to the transport direction in the transport path and transporting it to a path different from the transport path. ,
When the length of the recording paper on which the pages subsequent to the page to be jammed are normally printed is longer than a predetermined length in the transport path, the control means 4. The image forming apparatus according to claim 1, wherein the conveyance direction is switched and the trailing edge of the recording sheet is temporarily stopped in a path different from the conveyance path in the conveyance direction of the conveyance path.   Conveyance of a recording sheet on which a page to be jammed is printed by a printing operation restarted after the occurrence of the jam and a recording sheet once stopped in a discharge path different from the discharge path where the jam has occurred When the lengths of the directions are different, the predetermined timing is calculated between the recording paper on which the jammed page is printed and the recording paper once stopped in a paper discharge path different from the paper discharge path on which the jam has occurred. 5. The image forming apparatus according to claim 1, wherein the trailing ends of both recording sheets in the transport direction are timings at which paper is discharged to the paper discharge unit at the same time. The distance from the paper discharge path different from the paper discharge path where the jam occurs to the paper discharge unit is longer than the distance from the paper discharge path where the jam occurs to the paper discharge unit,
When the control unit discharges the recording paper once stopped in a paper discharge path different from the paper discharge path where the jam has occurred to the paper discharge unit via the paper discharge path, The image formation according to claim 1, wherein the target page is printed and the recording paper is transported at a speed lower than a transport speed when the recording paper is ejected via the paper ejection path where the jam has occurred. apparatus.   When the length of the recording paper once stopped in a paper discharge path different from the paper discharge path where the jam has occurred is shorter than a predetermined length, the control means The image forming apparatus according to claim 6, wherein the recording sheet is conveyed at a speed slower than a conveying speed when the recording sheet is printed and discharged through the paper discharge path where the jam has occurred. While the recording paper is being transported in the transport path that continues from the paper feed unit to the paper discharge unit, an image is printed on the recording paper by the image forming means provided facing the transport path, and the printed recording paper is A method of controlling an image forming apparatus that discharges to a paper discharge unit,
The conveyance path branches downstream of the position where the image forming unit is disposed in the conveyance direction into two or more paper discharge paths for discharging the conveyed recording paper to the paper discharge unit. And
Detecting the occurrence of a jam in any one of the two or more paper discharge paths;
The recording paper that follows the recording paper to be jammed, and on which the pages after the page to be jammed are normally printed, the jam occurred in the two or more paper discharge paths. Transporting to a paper discharge path different from the paper discharge path and temporarily stopping in the paper discharge path;
When the printing operation is resumed after the occurrence of the jam, printing the target page of the jam and discharging the page to the paper discharge unit via the paper discharge path where the jam has occurred;
At a predetermined timing after the recording paper on which the page to be jammed has reached the paper ejection path where the jam occurred, the recording paper is temporarily stopped in a paper ejection path different from the paper ejection path where the jam occurred. And a step of discharging the recording paper to the paper discharge unit via the paper discharge path. While the recording paper is being transported in the transport path that continues from the paper feed unit to the paper discharge unit, an image is printed on the recording paper by the image forming means provided facing the transport path, and the printed recording paper is A control program for controlling an operation at the time of printing after a jam occurs in an image forming apparatus that discharges to a paper discharge unit,
The conveyance path branches downstream of the position where the image forming unit is disposed in the conveyance direction into two or more paper discharge paths for discharging the conveyed recording paper to the paper discharge unit. And
Detecting the occurrence of a jam in any one of the two or more paper discharge paths;
The recording paper that follows the recording paper to be jammed, and on which the pages after the page to be jammed are normally printed, the jam occurred in the two or more paper discharge paths. Transporting to a paper discharge path different from the paper discharge path and temporarily stopping in the paper discharge path;
When the printing operation is resumed after the occurrence of the jam, printing the target page of the jam and discharging the page to the paper discharge unit via the paper discharge path where the jam has occurred;
At a predetermined timing after the recording paper on which the page to be jammed has reached the paper ejection path where the jam occurred, the recording paper is temporarily stopped in a paper ejection path different from the paper ejection path where the jam occurred. A control program for causing the image forming apparatus to execute a step of discharging recording paper to the paper discharge unit via the paper discharge path.

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