JPH10152246A - Control method for image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce discarded paper and paper jam disposal to a required minimum so as to suppress downtime to a minimum by discharging recorded material, fed into an image forming conveyance part from a register part, to the outside of a device in case of the occurrence of trouble, and resuming an image forming process with recorded material in a paper feeding conveyance part to the register part. SOLUTION: A conveyance system has an image forming conveyance part A (A-zone) for discharging paper P to the outside of a device by a discharge paper roller pair 7 via an image forming part 4 from a register roller pair (a register part) 6, and a paper feeding conveyance part C (C-zone) for conveying paper P in a paper feeding cassette 5 sheet by sheet to the register roller pair 6. In case of the generation of a jam of paper P, a jam of documents at an ADF or trouble such as power failure during continuous image formation, a control means controls in such a way as to carry out image formation without removing untransferred paper Pb existing in the C-zone. Discarded paper P and paper jam disposal of an operator are therefore reduced to a required minimum, and downtime can be suppressed to a minimum.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for controlling an image forming apparatus such as a copying machine, a printer, and a printing machine.

[0002]

2. Description of the Related Art Conventionally, in an image forming apparatus such as a copying machine, a paper jam occurs when an image is continuously formed on a recording material (transfer paper, thermal paper, magnetic recording, OHP sheet, etc.). Has occurred, the apparatus is stopped based on the paper jam detection signal, and the position of the paper jam is displayed to indicate that a paper jam has occurred.

After the operator removes not only the jammed recording material but also all the recording material remaining in the transport section,
The image forming process was restarted.

[0004]

However, the above-mentioned prior art has the following drawbacks.

[0005] 1. Paper that has stopped between the paper cassette and the image forming unit (blank paper) or paper with only one side formed in the main body of the apparatus that forms images on both sides or in a multiple-sided form is discarded. It is extremely uneconomical.

[0006] 2. As described above, for example, when the operator removes the paper remaining on the paper transport belt, it is difficult to work because the paper is in close contact with the electrostatic force, and the paper transport belt may be damaged.

[0007] 3. When the unfixed paper is removed, not only the operator's hands but also the clothes and the inside of the apparatus main body may be stained by the developer.

[0008] 4. Since the paper feeding is restarted after the paper jam is restarted, productivity is significantly reduced.

In view of the above-mentioned conventional problems, the present invention is intended to solve the following problems when a trouble such as a paper jam occurs. 1. Minimize the amount of discarded paper. 2. Minimize paper jam handling by the operator. The aim is to minimize downtime.

[0010]

The present invention is a control method for an image forming apparatus having the following configuration. [1] In an image forming apparatus for forming an image on a recording material, a sheet feeding / conveying unit for conveying the recording material from a sheet feeding unit to a registration unit, and a recording material from the registration unit are conveyed to form an image. And an image forming / conveying unit that discharges to the outside of the apparatus via a unit.When a trouble occurs in the apparatus, the apparatus including the respective conveying units is temporarily stopped based on a detection signal of the trouble, and when the apparatus driving is restarted, A method for controlling an image forming apparatus, comprising: discharging a recording material present in an image forming / conveying unit to the outside of the apparatus; and restarting an image forming process from the recording material present in a sheet feeding / conveying unit.

[2] In an image forming apparatus for forming an image on a recording material, a paper feeding / conveying unit for conveying the recording material from a paper feeding unit to a registration unit, and conveying the recording material from the registration unit. And an image forming / conveying unit that discharges outside the apparatus via the image forming unit, and when a paper jam occurs in the sheet feeding / conveying unit, stops the sheet feeding / conveying unit based on the detection signal of the paper jam. At the same time, after the recording material present in the image forming / conveying section is discharged out of the apparatus, the driving of the apparatus is temporarily stopped, and when the driving of the apparatus is resumed, the image forming process is restarted from the recording material present in the sheet feeding / conveying section. A method of controlling an image forming apparatus.

[3] In an image forming apparatus for forming an image on a recording material, a sheet feeding / conveying unit for conveying the recording material from a sheet feeding unit to a registration unit, and conveying the recording material from the registration unit. An image forming / conveying unit that discharges outside the apparatus via the image forming unit, and a recording material on which image forming has been performed on one side by branching downstream of the image forming / conveying unit in the recording material conveying direction. Or a re-feeding conveyance unit that conveys the sheet to the registration unit without reversing. When a trouble occurs in the apparatus, the apparatus including the respective conveyance units is temporarily stopped based on a detection signal of the trouble, and the driving of the apparatus is restarted. An image forming apparatus characterized in that the recording material present in the image forming / conveying section is sometimes discharged outside the apparatus, and the image forming process is restarted from the recording material present in the sheet feeding / conveying section or the re-feeding conveying section. Control method.

[4] When the apparatus is restarted, the image forming process is restarted from a recording material stopped at a position close to the registration section in the sheet feeding / conveying section or the re-feeding / conveying section [3]. A method for controlling an image forming apparatus.

[5] A detecting means is provided at a position equidistant from the registration section of each of the re-feeding conveyance section and the paper feeding conveyance section, and the object stopped at a position close to the registration section based on a signal from the detection section. The method for controlling an image forming apparatus according to [3] or [4], wherein the image forming step is restarted from the recording material.

[6] In an image forming apparatus for forming an image on a recording material, a paper feeding / conveying unit for conveying the recording material from a paper feeding unit to a registration unit, and conveying the recording material from the registration unit. An image forming / conveying unit that discharges outside the apparatus via the image forming unit, and a recording material on which image forming has been performed on one side by branching downstream of the image forming / conveying unit in the recording material conveying direction. Or a re-feed conveyance section for conveying the sheet to the registration section without reversing the sheet. When a paper jam occurs in the sheet conveyance section or the re-feed conveyance section, the paper jam is detected based on the detection signal of the paper jam. After the conveyance section where the occurrence of the error occurred, the recording material present in the image forming / conveying section was discharged out of the apparatus, the apparatus driving was stopped, and when the apparatus driving was restarted, the paper jam did not occur. Exists in the paper feeder or re-feeder Method of controlling an image forming apparatus characterized by resuming the image forming process of the recording material that.

[7] Any one of [3] to [6], wherein image information of the front side and the back side of the document is stored in a memory, and an image is formed based on the stored image information. 6. A method for controlling an image forming apparatus according to any one of claims 1 to 4.

[8] The method for controlling an image forming apparatus according to any one of [2] to [7], wherein the image forming apparatus has a trayless automatic double-sided mechanism.

<Operation> [1] When a trouble occurs in the apparatus, the driving of the apparatus including each transport unit is temporarily stopped based on a detection signal of the trouble, and when the driving of the apparatus is resumed, the recording material existing in the image forming / transporting unit is stopped. Is discharged from the apparatus, and the image forming process is restarted from the recording material present in the paper feeding / conveying unit, thereby automatically discharging the recording material present in the image forming / conveying unit in which the image formation has been interrupted, The recording paper present in the paper feed unit before the image formation is started is used for the next image formation without being discharged.

As a result, the paper jam of the operator need only be performed on the recording material that cannot be automatically ejected, and the paper jam of the operator is minimized.

Further, since the recording material before image formation can be used for the next image formation, the amount of discarded paper is minimized.

Further, since the paper jam processing by the operator is minimized and the recording is started from the recording material present in the sheet feeding and transporting section, the downtime can be minimized.

[2] When a paper jam occurs in the paper feeding / conveying unit, the paper feeding / conveying unit is stopped based on the detection signal of the paper jam, and the recording material present in the image forming / conveying unit is discharged out of the apparatus. After that, the apparatus driving is temporarily stopped, and when the apparatus driving is resumed, the image forming process is restarted from the recording material present in the sheet feeding / conveying section. The recording material present in the forming / transporting unit is automatically discharged without interrupting the image formation, and the unrecorded recording paper present in the sheet feeding / conveying unit at the time of resumption is used for the next image formation.

As a result, the paper jam of the operator need only be performed for the recording material that cannot be automatically ejected, and the paper jam of the operator is minimized.

Further, since the image formation does not have to be interrupted even if a paper jam occurs, and the recording material without the paper jam can be used for the next image formation, the discarded paper is minimized. I have.

Further, since the paper jam processing by the operator is minimized and the recording is started from the recording material present in the paper feeding and conveying section, downtime can be minimized.

[3] When a trouble occurs in the apparatus, the driving of the apparatus including each transport unit is temporarily stopped based on the detection signal of the trouble, and when the driving of the apparatus is restarted, the recording material present in the image forming / transporting unit is removed from the apparatus. And the image forming process is restarted from the recording material present in the paper feeding conveyance unit or the re-feeding conveyance unit, so that the recording material existing in the image forming conveyance path where the image formation has been interrupted is automatically The recording sheet that has been discharged and is present in the sheet feeding / conveying unit or in the sheet re-feeding / conveying unit before the image formation is started is used for the next image forming without being discharged.

Thus, the paper jam of the operator need only be performed for the recording material that cannot be automatically ejected, and the paper jam of the operator is minimized.

Further, since the recording material before image formation can be used for the next image formation, the amount of discarded paper is minimized.

Further, since the paper jam processing by the operator is minimized, and the recording is started from the recording material present in the sheet feeding and re-feeding section, the down time can be minimized. .

[4] When a paper jam occurs in the paper feeding / conveying section or the re-feeding / transporting section, the conveying section in which the paper jam has occurred is stopped based on the detection signal of the paper jam and the image forming / conveying section is stopped. After the recording material present in the printer is discharged out of the apparatus, the driving of the apparatus is stopped, and when the driving of the apparatus is restarted, the recording medium is present in the sheet feeding section where no paper jam has occurred or in the sheet re-feeding section. By restarting the image forming process from the recording material, the recording material existing in the image forming / transporting unit when a paper jam occurs in the sheet feeding / transporting unit or the re-feeding / transporting unit can be automatically performed without interrupting the image formation. Discharge,
The non-jammed recording paper present in the paper feed transport unit or the paper feed transport unit at the time of restart is used for the next image formation.

Thus, the paper jam processing of the operator need only be performed for the recording material that cannot be automatically ejected, and the paper jam processing of the operator is minimized.

Further, since the image formation does not have to be interrupted even if a paper jam occurs and the recording material without the paper jam can be used for the next image formation, the discarded paper is minimized. I have.

Further, since the paper jam processing by the operator is minimized, and the recording is started from the recording material present in the sheet feeding / conveying section or the re-feeding / conveying section, downtime can be minimized. .

[0034]

BEST MODE FOR CARRYING OUT THE INVENTION

<First Embodiment> A first embodiment of the present invention will be described below with reference to the accompanying drawings. FIG. 1 is a schematic configuration diagram of an image forming apparatus of the present embodiment, and FIG. 2 is a block diagram of control of the image forming apparatus. The apparatus according to the present embodiment is a copier using an electrophotographic process that reads image information on the front and back surfaces of a document, accumulates the information in a memory, and forms an image on the front and back surfaces of a recording material based on the image information.

1. In the figure, reference numeral 2 denotes a reading unit with an ADF for reading a conveyed document by conveying it one sheet at a time, and 3 denotes a memory for storing image information read by the reading unit.

A toner image 4 is transferred to a transfer material (recording material, hereinafter referred to as "paper") P by a transfer method based on the image information stored in the memory, and the toner image is heated and fixed. An image forming unit for forming an image.

Reference numeral 5 denotes a paper cassette in which the paper P is stored, and reference numeral 6 denotes a registration roller (registration unit) for feeding the paper P fed from the paper cassette 5 to the image forming unit at a predetermined timing. ), 7 is a paper discharge roller for discharging the paper P on which image formation has been completed to the outside of the apparatus; The transport system includes elements 5, 6, 7, and 8 for feeding and discharging paper, and a transport unit for transporting and re-transporting to the image forming unit 4.

Reference numeral 10 denotes a control means for controlling the driving of the elements 1, 2, 3, 4 and the like constituting the apparatus of this embodiment.

When a document is stacked on the ADF and the start of image formation is instructed, for example, the image information on the front and back sides of the document is read by the reading means 2 and stored in the memory 3.
The image forming operation of the image forming unit is started based on the image information. On the other hand, the transport system 1 feeds and transports the paper P from the paper feed cassette 5 in synchronization with the start of the image formation, and introduces the paper P into the image forming unit 4 at a predetermined timing by the registration roller 6. I have. The image forming unit 4 uses the introduced paper P
In this case, a toner image is carried by a transfer method, and this is heated and fixed to form an image. If an image is to be formed on the back surface of the paper P, the paper P is turned upside down and transported again to the upstream of the registration roller 6 as described later, and the image is formed again. Then, the paper P on which the image formation is completed is discharged out of the apparatus by the discharge roller 7.

2. Image Forming Unit 4 Next, the components 4a to 4g constituting the image forming unit 4 will be described. 4a is a rotary drum type electrophotographic photosensitive member, 4b
Are contact charging rollers as charging means for the photosensitive member 4a;
c is an exposure means for optically scanning the surface of the photoreceptor 4a to form an electrostatic latent image, 4d is a developing means for developing the latent image as a toner image, and 4e is a transfer material (recording material, hereinafter "paper"). Transfer conveyance means for conveying P and transferring a toner image onto the paper P; 4f, a cleaning means for removing residual deposits such as untransferred toner on the photoreceptor surface; and 4g, the unfixed toner. A fixing unit that heats and fixes the paper P carrying the image.

The photosensitive member 4a is rotationally driven at a predetermined process speed (peripheral speed) in the clockwise direction of the arrow in the figure, and is uniformly charged to a predetermined polarity and potential by the contact charging roller 4b during the rotation process. The laser beam L light-modulated based on the image information by the exposure means is optically scanned on the charged surface of the photoconductor 4a on the charged surface to form an electrostatic latent image corresponding to the image information. Developing means 4
In the image d, toner is applied to the photosensitive surface on which the latent image is formed, and the latent image is visualized (toner image).

On the other hand, at the timing synchronized with the formation of the toner image, the paper P introduced from the registration roller 6 is transported by the transfer transporting means 4e, and the back of the paper P is located immediately below the photosensitive member 4a (transfer section t). The transfer bias is applied from the side to transfer the toner image on the photosensitive surface onto the paper P, and is conveyed to the fixing unit 4g. In the fixing unit 4g, the paper P carrying the toner image
Is conveyed through a nip formed by a heater and a pressing member pressed against the heater, and the toner image is fixed (fixed) to the paper P by applying a pressing force and heat from the heater.

2. Transport System The transport system according to the present embodiment is configured to transfer the paper P to a pair of registration rollers 6.
And an image forming / conveying unit A (A zone) which is conveyed to the outside of the apparatus by a pair of paper discharge rollers 7 via an image forming unit 4, and a paper P which is branched and conveyed downstream of the fixing device 4g in the A zone. A paper re-feeding and transporting section B (B zone) for re-transporting to the registration roller pair 6, and a paper feeding and transporting section C (C zone) for transporting the paper P loaded in the paper feeding cassette 5 to the registration roller pair 4 for one sheet. And so on.

Reference numerals 1a, 1b, 1c and 1d denote detecting means for detecting the presence or absence of the paper P. Pa to Pf each indicate paper P in the middle of conveyance, Pa and Pb are untransferred papers, Pa is in the middle of being conveyed from the paper feed cassette 5 to the registration roller pair 6, and Pb is the image forming unit 4. Transfer part t
In the middle of being transported to Pc, Pd, and Pe are surface transfer papers (small circles in the figure indicate transfer surfaces), Pc is in the middle of being conveyed to the reverse re-feeding unit 8, and Pd and Pe are transfer in the reverse re-feeding unit. Is in the middle of being conveyed to the image forming unit for the above. Pf is the paper on which the back side has been transferred (the small circle in the figure indicates the transfer surface), ie, the paper on which the double-side transfer has been completed is the fixing device 4g.
Is shown.

3. Restart operation after occurrence of trouble in the apparatus In such an image forming apparatus, troubles such as jamming of paper P (paper jam), jamming of documents in the ADF, power failure, etc. occur during continuous image formation. If you do
Conventionally, all the paper P remaining in the transport system is removed. However, in the present embodiment, the untransferred paper Pb existing in the C zone is removed.
In addition, the control unit 10 controls so that image formation can be performed without removing the surface transfer paper B existing in the B zone.

3a) When a Paper Jam Occurs in Zone A First, the control when a paper jam occurs in Zone A will be described. FIG. 3 is a flowchart of the control when the trouble occurs.

For example, in FIG. 1, the paper Pf is jammed at the entrance of the fixing device 4g (paper jam occurs), and the sensor 1
d, the control means 10 determines that a paper jam has occurred in zone A (step S1, hereinafter simply S1).
Next, it is detected whether the paper P reaching the registration roller 5 is a surface transfer paper from the B zone or a non-transfer paper from the C zone. The surface transfer paper and the untransferred paper are transported alternately, and the paper P is not transported to the positions of the detecting means 1b and the detecting means 1c at the same time.
It can be detected by referring to the signals from b and 1c. That is, the presence or absence of the paper P at the merging point of the B and C zones is detected by the detection means 1a (S2), and the detection means 1a
In the case of F, it is determined at which position of the detecting means 1b or 1c the paper P is located (S3).
If N, it is determined that the next transfer to the registration roller 6 is the surface transfer paper, and the apparatus is temporarily stopped, and a message indicating that a paper jam has occurred in the A zone is displayed to the operator. Encourage elimination. Then, when the operator clears the paper jam and instructs to restart the apparatus, the paper P present in the A zone is automatically discharged, and then the image forming apparatus resumes the image formation on the untransferred paper (that is, the image formation on the back surface) (S4). ). On the other hand, if the detecting means 1b is ON in step S3, it is determined that the untransferred paper reaches the registration roller 6 next, and as in step S4, it waits for a restart instruction, and exists in zone A at the time of restart. The paper P is automatically discharged, and the process is restarted from the surface formation (S5).

If the detecting means 1a is ON in step 2, it is determined at which position of the detecting means 1b or 1c the paper P is located (S6). It can be determined that the paper P on the downstream side is the front transfer paper, and at the time of resumption, the paper P present in the A zone is automatically discharged, and the process is resumed from the back surface formation (S7). Conversely, if the detection means 1c is ON, it can be determined that the paper P immediately downstream thereof is untransferred paper, and when the paper P is restarted, the paper P present in the zone A is automatically discharged and the image formation on the front surface is resumed. (S8).

3b) Case where a paper jam occurs in the B zone or the C zone Next, a case where a paper jam occurs in the B zone or the C zone will be described. For example, in FIG. 1, when the paper Pd does not reach the detection unit 1c at a predetermined timing, the control unit 10 determines that a paper jam has occurred in the B zone (S1), stops the conveyance in the B zone and the C zone, and The paper P in the A zone is automatically discharged (the transfer and fixing process of the toner image is completed and discharged in the middle. The same applies hereinafter). The cancellation is prompted (S9). At this time, the operator removes only the paper P in the B zone and makes use of the paper P in the C zone. Then, when the operator instructs to resume, the operation is resumed from the surface formation (S10).

Also, when it is determined that a paper jam has occurred in the C zone (S1), similarly, the conveyance in the B zone and the C zone is stopped, and the paper P in the A zone is automatically discharged.
After the discharge, the apparatus is temporarily stopped to urge the operator to clear the paper jam in the C zone (S11). Then, when the operator instructs to resume, the operation is resumed from the back surface formation (S12).

3c) When Other Troubles Occur When a trouble other than a paper jam, such as a jammed document in the ADF, that does not hinder the paper transport in the A zone occurs.
As shown in the steps S2 to S8, the paper P that reaches the registration roller 6 next is detected, the conveyance in the B zone and the C zone is stopped, and the paper P in the A zone is automatically ejected. The operation is stopped and the operator is urged to resolve the trouble. When the restart is instructed after the trouble is resolved, the image formation is restarted from the paper P detected first and then reaching the registration roller 6.

When the apparatus is stopped without performing control such as automatic discharge of the A zone due to a power failure or the like, automatic discharge of the A zone is performed at the time of resumption and at the same time as the step S2.
As shown in steps S8 to S8, the paper P that reaches the registration roller 6 is detected, and image formation is started from the surface-transferred paper or untransferred paper detected at this time.

According to the present embodiment, when a trouble such as a paper jam occurs, the amount of paper P to be discarded can be minimized, and the paper jam processing by the operator can be minimized.
Downtime can be minimized.

<Second Embodiment> FIG. 4 is a schematic structural view of a second embodiment of the present invention. This embodiment is different from the first embodiment shown in FIGS. 1 and 2 in the arrangement of the detecting means for the paper P, and the other configurations are substantially the same. In this embodiment, the same elements as those in the above-described embodiment are denoted by the same reference numerals, and the description thereof will not be repeated.

In the figure, reference numerals 1e and 1f denote detection means provided in the C zone and the B zone, respectively, which are disposed at the same distance from the registration roller 6. Reference numeral 15 denotes a portion where the C zone and the B zone are joined, and a double-sided untransferred sheet and a single-sided transferred sheet are alternately conveyed during double-sided image formation.

In this embodiment, when a trouble occurs, the detecting means 1e, 1f of the paper P which has just passed through the detecting means 1e, 1f.
f, the presence or absence of the paper P at the position 15 is detected based on the elapsed time after passing through the f.
Whether the paper P is an untransferred paper or a surface transfer paper is determined based on whether the paper P has passed f. For example, in the case of FIG.
The paper P that has passed just before the detecting means 1e and 1f is the paper Pe that has passed the detecting means 1f, and the paper Pe is the paper Pe.
Since the elapsed time after passing f is within the predetermined time, it can be determined that the front surface transfer paper Pe exists at the position 15. Thus, when the image forming process is restarted, the front transfer paper Pe is first conveyed to form the back surface.

Therefore, according to the present embodiment, there is no need to provide a detecting means at the position 15 where the C zone and the B zone merge, and the configuration can be simplified, and the cost can be reduced.

<Others> In the above embodiment, the case of double-sided copying has been described.
The present invention can be applied to a single-sided copy as shown in FIG.

In this example, when a paper jam occurs in the A zone, the paper P existing in the A zone is removed after the paper jam is cleared.
Is automatically discharged, and the image formation is restarted from the paper P present in the C zone. When a paper jam occurs in the C zone, the apparatus stops driving after automatically discharging the paper in the A zone, and makes use of the paper in the A zone.

[0060] In the apparatus shown in FIGS. 1 and 4, the re-feeding conveyance unit B only shows the path for reversing the paper P in the reversing unit 8, but the paper P from the image forming / conveying unit A passes through the reversing unit 8. That is, the sheet may be re-conveyed to the image forming unit 4 without reversing the front and back sides, and an image may be formed on one side.

[0061] The image forming apparatus of the present invention may be of a “tray type” in which the surface transfer paper is temporarily stored in a tray in the conveyance path at the time of double-sided copying or double-sided printing.

[0062] Since color copying and color printing have a large amount of toner fixed to paper in four colors, curling and other warpages are likely to occur. When performing double-sided copying or double-sided printing, it is necessary to temporarily accumulate the surface transfer paper on the tray in the transport path. With the "tray method", paper jams were easy. On the other hand, in a so-called “trayless method” apparatus that reverses the front and back surfaces of the front transfer paper at the reversing unit and reconveys the paper during duplex copying (duplex printing), the paper to be transported is always held by rollers. This is an effective means for reliably transporting the paper.

However, the apparatus of the "trayless system" has a disadvantage that once the paper jam occurs, a large amount of useless paper is generated because the paper transport distance is long. In particular, in the case of color copying and color printing, the cost per sheet is higher than that of black and white, so that wasteful paper is extremely uneconomical.

Therefore, by applying the present invention to the “tray-less type” apparatus, the paper can be transported without fail.
The amount of paper discarded in the event of a trouble can be reduced.
Therefore, it is particularly effective in a color machine.

[0065]

As described above, according to the present invention,
When troubles such as paper jam occur, 1. 1. Minimize the amount of discarded paper. 2. Minimize paper jam handling by the operator. Downtime can be minimized.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram showing a first embodiment of the present invention.

FIG. 2 is a block diagram of a control system according to the first embodiment;

FIG. 3 is a flowchart of control when a trouble occurs.

FIG. 4 is a flowchart of a first embodiment and a second embodiment of the present invention.

FIG. 5 is a sectional view showing a third embodiment of the present invention.

[Explanation of symbols]

 1a, 1b, 1c, 1d Detecting means Pa, Pb Untransferred paper Pc, Pd, Pe, Pg Surface transfer paper Pf Double-sided transfer paper

Claims (8)

[Claims] 1. An image forming apparatus for forming an image on a recording material, comprising: a sheet feeding conveyance unit for conveying the recording material from a sheet feeding unit to a registration unit; and a recording material from the registration unit. An image forming / conveying unit which discharges the image to the outside of the apparatus via the image forming unit. When a trouble occurs in the apparatus, driving of the apparatus including each conveying unit is temporarily stopped based on a detection signal of the trouble to temporarily stop the driving of the apparatus. A method for controlling an image forming apparatus, comprising: discharging a recording material present in an image forming / conveying unit to the outside of the apparatus when resuming; and restarting an image forming process from a recording material present in a sheet feeding / conveying unit. 2. An image forming apparatus for forming an image on a recording material, comprising: a sheet feeding conveyance unit for conveying the recording material from a sheet feeding unit to a registration unit; and a recording material conveyed from the registration unit. An image forming / conveying unit which discharges the sheet to the outside of the apparatus via the image forming unit. When a paper jam occurs in the paper / conveying unit, the paper feeding / conveying unit is stopped based on the detection signal of the paper jam and After discharging the recording material present in the image forming / conveying unit out of the apparatus,
A method for controlling an image forming apparatus, comprising: temporarily stopping the apparatus driving, and resuming the image forming process from a recording material present in a sheet feeding unit when the apparatus driving is restarted. 3. An image forming apparatus for forming an image on a recording material, comprising: a sheet feeding / conveying unit for conveying the recording material from a sheet feeding unit to a registration unit; and a recording material from the registration unit. An image forming / conveying unit that discharges outside the apparatus via the image forming unit; and a recording material on which image forming on one side is branched by branching downstream of the image forming / conveying unit in the recording material conveying direction, or A re-feeding conveyance unit that conveys the sheet to the registration unit without reversing. When a trouble occurs in the apparatus, the apparatus including the respective conveyance units is temporarily stopped based on a detection signal of the trouble, and when the apparatus driving is restarted, Control of the image forming apparatus, wherein the recording material present in the image forming / conveying unit is discharged out of the apparatus, and the image forming process is restarted from the recording material present in the paper feeding / conveying unit or the re-feeding / conveying unit. Method. 4. The image forming process according to claim 3, wherein when the apparatus is restarted, the image forming process is restarted from the recording material stopped at a position close to the registration unit in the sheet feeding and conveying unit or the re-feeding and conveying unit. A method for controlling an image forming apparatus. 5. A recording means which is provided at a position equidistant from the registration section of each of the re-feeding conveyance section and the paper feeding conveyance section and which stops at a position close to the registration section based on a signal from the detection section. 5. The control method for an image forming apparatus according to claim 3, wherein the image forming step is restarted from a material. 6. An image forming apparatus for forming an image on a recording material, comprising: a sheet feeding / conveying unit for conveying the recording material from a sheet feeding unit to a registration unit; and a recording material from the registration unit. An image forming / conveying unit that discharges outside the apparatus via the image forming unit; and a recording material on which image forming on one side is branched by branching downstream of the image forming / conveying unit in the recording material conveying direction, or A re-feeding transport unit that transports the paper to the registration unit without reversing the paper. When a paper jam occurs in the paper feeding transport unit or the re-feeding transport unit, the paper jam is detected based on the detection signal of the paper jam. After stopping the transporting unit where the recording has occurred and discharging the recording material present in the image forming transporting unit to the outside of the apparatus, the apparatus driving is stopped, and when the apparatus driving is resumed, the paper jam has not occurred. It exists in the paper feeder or re-feeder. Method of controlling an image forming apparatus characterized by resuming the image forming process of the recording material. 7. The image processing apparatus according to claim 3, wherein image information of the front side and the back side of the document is stored in a memory, and an image is formed based on the stored image information. A method for controlling an image forming apparatus. 8. The method according to claim 2, wherein the image forming apparatus has a trayless automatic double-sided mechanism.