JPH09114156A - Image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image forming device suppressing the loss to the minimum when a jam occurs. SOLUTION: The drive system of recording paper conveyance rollers on a conveyance path is divided into multiple systems (first drive system 21, second drive system 22, and third drive system 23), and various countermeasures can be taken when a jam occurs. More practically, the conveyance of the jammed paper is stopped when the jam occurs, and it can be removed by a user. The other recording paper left in the conveyance path at the time of the jam is returned to a paper feed section 1, or discharged from emergency paper discharge mechanisms 25, 27, or discharged from a paper discharge section 13. The reusable recording paper and the recording paper accurately formed with an image can be effectively utilized as they are.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming apparatus using a cut sheet as a recording sheet and having a conveyance path in which a plurality of recording sheets are present in the conveyance path during continuous printing.
In particular, it relates to the recording paper conveyance control system.

[0002]

2. Description of the Related Art FIG. 5 is a schematic configuration diagram centering on a recording sheet conveying path of a conventional image forming apparatus. A large amount of cut paper can be stocked in the paper feeding unit 1, and the paper is fed toward the paper feeding and conveying path 2 from here. The recording paper ejected to the paper feed / conveyance path 2 eventually adheres to the transfer belt 3, and sequentially contacts the four photoconductors 4 on which toner images of respective colors are formed to form a color image. The developing method is a wet electrophotographic method, and a charging charger 5,
A laser writing system 6, a developing unit 7, a transfer charger 8, a cleaning unit 9 and the like are arranged.

The recording paper on which the toner images of four colors are superposed is separated from the transfer belt 3 by the separation charger 10 and passed between the fixing rollers 11 to fix the image. Upon leaving the fixing unit, the recording paper is discharged to the paper discharge unit 13 through the paper discharge conveyance path 12. The transport path from the paper feed unit 1 to the paper discharge unit 13 includes a paper feed transport path 2, a transfer belt 3,
It is composed of the paper discharge conveyance path 12, and since the conveyance path is long, a plurality of recording sheets are present in the conveyance path during continuous printing (copying). In the image forming apparatus having such a configuration, when a jam occurs in the machine, the conveyance drive system is stopped all at once, and the jam paper and the recording paper existing in the machine body are generally taken out manually. Is used for.

[0004]

In the above prior art, in order to return the machine to the operable state after the operation is stopped due to the jam, all the recording papers existing in the conveying path are manually removed. There was a hassle of having to do it. In this case, the jammed paper cannot be conveyed, so it must be removed manually, but the other recording papers need not be treated as jammed paper. If these non-jam papers can be ejected by some method, the burden on the operator will be reduced.

A printing system using a wet electrophotographic system, particularly a full-color printing system, is used in the printing industry, and recording paper other than plain paper is often passed. In this case, some recording papers have a high unit price, so when jamming occurs, recording papers other than the jammed paper should not be treated as jammed papers and should either be printed normally and discharged, or reused. Is desired.

The present invention has been made based on such a background, and an object of the present invention is to provide an image forming apparatus capable of minimizing the loss when a jam occurs.

[0007]

In order to achieve the above object, the first invention uses a cut sheet as a recording sheet and conveys a plurality of recording sheets in the conveying path during continuous printing. In the image forming apparatus having a path, the drive system of the recording paper feeding and carrying roller group of the carrying path is divided into a plurality of parts.

[0008] A second invention is the first invention, wherein:
If a recording paper jam occurs in the transport path,
In addition to immediately stopping the conveyance of the jam-corresponding paper, the non-jam paper existing in the conveyance path is conveyed to an arbitrary position according to the location of the jam, and then the operation is stopped. It is characterized by

[0009] In a third aspect based on the first aspect,
An emergency paper discharge mechanism is provided at an arbitrary position near the transport path.

In a fourth aspect based on the first aspect,
It is characterized in that the conveying roller on the upstream side of the image forming unit is provided so as to be capable of being driven in reverse.

A fifth aspect of the invention is the same as the second aspect of the invention.
It is characterized in that control is performed to discharge the non-jam paper existing on the paper discharge side from the place where the jam has occurred to the paper discharge tray.

In a sixth aspect of the invention, in the second and third aspects of the invention, control is performed to eject the non-jammed paper existing in the conveyance path from the emergency paper ejection mechanism according to the location of the jam. It is characterized by being called.

In a seventh aspect of the invention, in the second and fourth aspects of the invention, the non-jammed paper present in the section of the feeding path and the entrance of the image forming section in the feeding path is fed backward to the feeding section. It is characterized in that control is performed to eject the paper.

An eighth aspect of the invention is an image forming apparatus which uses a cut sheet as a recording sheet and has a conveyance path in which a plurality of recording sheets are present in the conveyance path during continuous printing. When a recording paper jam occurs, the transportation of all the recording papers in the transportation path is stopped once, and after the jammed paper is removed, the recording papers existing in the transportation path are automatically moved to any position. It is characterized in that it is controlled to be transported to.

A ninth aspect of the invention is the same as the eighth aspect of the invention.
After the jammed paper is removed, control is automatically performed to discharge the recording paper existing in the conveyance path to the paper discharge tray.

A tenth aspect of the invention is the control according to the third and eighth aspects of the invention, in which after the jammed paper is removed, the recording paper existing in the conveyance path is automatically ejected from the emergency paper ejection mechanism. Is performed.

An eleventh aspect of the invention is the fourth and eighth aspects of the invention, in which after the jammed paper is removed, the recording paper existing in the section between the paper feed section and the image forming section entrance in the conveyance path is reversed. It is characterized in that control is carried out to convey and discharge the paper to the paper feed unit.

[0018]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention divides a drive system of a recording paper conveying roller in a conveying path into a plurality of parts,
Various types of measures can be taken when a jam occurs.

More specifically, when a jam occurs, the conveyance of the jammed paper is stopped so that the user can remove the jammed paper, but at the time of the jam, other recording papers remaining in the conveyance path are fed. Paper, eject it from the emergency paper ejection mechanism, or eject it from the paper ejection tray. By doing so, the reusable recording paper and the recording paper on which the image is accurately formed can be effectively used as they are.

A detailed description will be given below with reference to the accompanying drawings. The same parts as those in the conventional example shown in FIG. 5 are designated by the same reference numerals. FIG. 1 is a schematic configuration diagram centering on a recording paper conveyance path of an image forming apparatus according to a first embodiment of the present invention.

In the present invention, the drive system of the recording paper carrying roller in the carrying path is divided into a plurality of parts. In this figure, the drive system is divided into three systems: a first drive system 21 at the paper feed port to the transfer belt entrance, a second drive system 22 at the transfer belt 3 portion, a transfer belt 3 exit to the paper discharge port. Third
It is a drive system 23. However, the finer the division of the drive system, the finer the control is possible, so it is better to divide the drive system as finely as possible.

Each drive system has its own motor, or
Either the driving force is turned on or off by the clutch, but in either case, the number of parts increases, so the number of systems to be divided is determined in consideration of cost performance. With the configuration shown in Fig. 1,
When a jam occurs somewhere in the first drive system 21 or the second drive system 22, the third drive system 23 located at the rearmost side can be conveyed regardless of the jam. Third
The fixing roller 11 is at the head of the drive system 23, and heat is generated to a considerable temperature in the case of the heat roller system.

If a jam occurs in the first to third drive systems 21 to 23, it is not preferable that all the conveyance drive is stopped and the recording paper is stopped at the fixing roller 11 part. The recording paper may be curled by being exposed to heat for a long time and may be wound around the fixing roller 11 to cause a new jam, and in the worst case, the recording paper may be ignited by overheating. . Therefore, in this case, it is preferable that only the third drive system 23 continues the conveyance drive and the conveyance drive of the third drive system 23 is stopped when the recording paper is ejected from the fixing roller 11.

Further, in the configuration as shown in FIG. 1, the non-jammed paper is directly ejected depending on the place where the jam occurs.
It is also possible to discharge to 3. For example, when a jam occurs in the first drive system 21, the second drive system 2
2. Since the operations of the third and third drive systems 23 do not have to be stopped immediately, the recording paper positioned after the second drive system 22 may be normally printed and discharged. Also,
When a jam occurs in the second drive system 22, it is preferable to eject the recording paper positioned in the third drive system 23 after printing is completed.

FIG. 2 is a schematic configuration diagram centering on the recording paper conveyance path of the image forming apparatus according to the second embodiment of the present invention. This embodiment shows an example including an emergency paper ejection mechanism. Specifically, a first switching claw 24 and a first emergency paper ejection tray 25 are provided near the upstream side of the transfer belt 3, and a second switching claw 26 and a second emergency paper ejection tray 25 are provided at the paper ejection port. The paper tray 27 is provided.

The emergency paper ejection mechanism may be arranged at the exit of the transfer belt 3 if space permits, or if the drive system is divided into smaller parts, it should be installed at the end of each drive system. Can be considered. With the configuration shown in FIG. 2, the non-jammed paper before printing can be reused because it can be ejected without passing through the image forming section, and the recording paper that has been improperly printed due to the occurrence of a jam It can be divided and ejected.

As an operation example, for example, the second drive system 2
When a jam occurs in 2, the recording paper positioned in the first drive system 21 is discharged to the first emergency paper discharge tray 25 by the first switching claw 24 and then the first drive system 21 is stopped. . The printed recording paper located in the third drive system 23 is ejected to the paper ejection unit 13 and then the third drive system 23 is ejected.
Stop driving.

In this case, the second drive system 22 immediately stops the conveyance drive, but depending on the transfer belt length, a plurality of recording sheets remain on the transfer belt 3. For example, when it is determined that one of the sheets is wound around the photoconductor 4 and a jam occurs, it is necessary to manually remove only the jam-corresponding sheet, and another recording sheet on the transfer belt 3 is required. Need not be removed.

However, once the conveyance is stopped, it is considered that some trouble will occur in the image, and it must be treated as misprinted paper. Therefore, when the jammed paper is removed and the machine returns, these misprinted papers are conveyed and discharged to the second emergency paper discharge tray 27.
There is also the idea of ejecting the misprinted paper to the paper ejection unit 13, but in the case of a large system, the paper ejection unit 13 may be a built-in type. It is better to discharge them separately so that they do not get mixed.

FIG. 3 is a schematic configuration diagram of the vicinity of the paper feed section of the image forming apparatus according to the third embodiment of the present invention. In this embodiment, the upstream side of the image forming unit (the position before touching down the transfer belt 3), that is, the roller group (pickup roller 31, paper feed roller 32, and transport roller 34) of the first drive system 21 is driven. By switching the force transmission path or reversing the direction of the current supplied to the drive motor, reverse rotation driving is possible, and the recording paper in the paper feeding and conveying path 2 can be fed back to the paper feeding unit 1. There is.

The operation of the paper feeding and conveying section shown in FIG. 3 will be described below. The recording paper in the paper feed unit 1 is constantly pressed by the pickup roller 31 by the pressure of the movable bottom plate 35, and when the pickup roller 31 rotates in the counterclockwise direction, the recording paper in the upper layer portion is conveyed accordingly. . The number of recording sheets conveyed at this time is not limited to one sheet, and a plurality of sheets may be simultaneously fed. A reverse roller 33 with a torque limiter is installed opposite to the paper feed roller 32. Here, only the uppermost recording paper sheet is sent to the paper feed conveyance path 2, and the remaining recording paper sheets are stored in the reverse roller 33. It is returned to the inside of the sheet feeding section 1 by the function. After that, it is only conveyed toward the transfer belt 3 by the conveyance rollers 34 in the paper feed conveyance path 2.

When the recording paper in the paper feed / conveyance path 2 is to be conveyed in the reverse direction, the pickup roller 31 and the paper are fed by switching the driving force transmission path or reversing the direction of the current supplied to the drive motor. The roller 32 and the transport roller 34 are driven to rotate in reverse. Since only the reverse roller 33 originally rotates in the opposite direction, the reverse roller 33 is rotated in the normal direction. By rotating each roller in the reverse direction, the recording paper is conveyed back into the paper feeding unit 1, but the pickup roller 3
1 and the recording paper in the paper feed unit 1 are in contact with each other, the recording paper in the upper layer is further conveyed in the opposite direction, which is unsatisfactory, and the recording paper conveyed backward from the paper feed conveyance path 2 is well accommodated. Not necessarily.

Therefore, in the case of reverse conveyance, the movable bottom plate 3 is used.
5 is lowered to make a gap under the pickup roller 31. By doing so, the recording paper in the paper feeding / transporting path 2 can be transported back into the paper feeding unit 1.

Regarding the situation where the reverse conveyance is performed, FIG. 1 and FIG.
It is conceivable that a jam occurs in the second and third drive systems 22 and 23. At the time when a jam occurs in the second and third drive systems 22 and 23, an image is not formed on the recording paper positioned in the first drive system 21 and the image forming section has not passed, There is no dirt. Therefore, since the recording paper can be reused, at the same time as the occurrence of the jam, the first drive system 21 reversely conveys and discharges the paper into the paper feeding unit 1. It is also conceivable to carry the paper backward after removing the jammed paper, which will be described later.

FIG. 4 is a schematic configuration diagram of a body side plate portion of an image forming apparatus according to a fourth embodiment of the present invention. In this embodiment, a side plate door 42 for removing jammed paper is attached to a side plate 41 of the main body.
Is provided. However, this drawing is drawn only for the jam removal of the image forming unit. A door open / close sensor 43 is installed below the base of the door 42 to detect the open / closed state of the door 42. This sensor 43 is, for example, a simple push switch, and the door 4
When 2 is closed, the switch is pushed so that it can be detected. When a recording paper jam occurs in the conveyance path and at the same time when the conveyance of all recording paper is stopped and the jammed paper is taken out manually, it is detected that the jammed paper is removed after the jammed paper is taken out, It is necessary to carry non-jammed paper.

The door open / close sensor 43 is used as a trigger signal for detecting the presence or absence of the jammed paper. After the door 42 is opened and closed once, a jam occurs. The jam detection sensor (not shown) at the relevant place is read, and if the jammed paper is removed, the non-jammed paper starts to be conveyed. Display and do not start operation. The location where the jam occurs is stored in a RAM (not shown).

This operation is performed when the non-jammed paper is discharged to the paper discharge section 13 after the jammed paper is removed, or when it is discharged to the emergency paper discharge mechanism, and the first drive system 21 shown in FIGS. The same applies to the case where the non-jammed paper is transported to the paper feed section in the reverse direction.

As described above, when a jam occurs, the operation is stopped after the non-jam paper is conveyed and discharged, and the non-jam paper is conveyed and discharged after all operations are stopped and the jammed paper is taken out. Although the operation of No. 1 has been described, it is considered that the combination of both or only the latter is almost the case.

The former has the effect of preventing waste of paper, which reduces misprints, and the effect of preventing recording paper from being stopped between fixing rollers, by preventing non-jammed paper from stagnation in the transport path. However, the non-jammed paper in the same drive system as the place where the jam occurs is inevitably stopped in the transport path. Therefore, it is necessary to discharge it when the machine body returns, and it must be used in combination with the latter.

In the latter case, all operations are stopped at the same time when a jam occurs, so that the control is simplified, but it is meaningless to make non-jam paper stagnate in the conveyance path, or to judge the jammed paper when removing the jammed paper. Considering from the viewpoint of difficulty, it is considered that it is better to use it together with the former.

[0041]

According to the first aspect of the present invention, by systematizing the driving of the conveying rollers to a plurality of ways, it becomes possible to stop or convey only the recording paper at a desired position, so that a jam occurs. It is possible to minimize productivity loss and waste of recording paper.

According to the second aspect of the invention, when the jam occurs, the jammed paper cannot be conveyed, so the conveyance is stopped, but it is not preferable to stop the recording paper for a long time except the jammed paper (for example, a place where it is not preferable). It is possible to avoid the gap between the fixing rollers) and to stop the recording paper after the image formation normally, so that it is possible to eliminate the waste of the recording paper other than the jam paper.

According to the third aspect of the present invention, when a jam occurs, a recording sheet on which printing has been improperly printed, such as a recording sheet whose operation has been interrupted during printing or a recording sheet left blank, is recorded. Since the paper can be discharged separately from the paper, it is possible to save the trouble of sorting the paper later and improve the productivity of the copying work.

According to the invention described in claims 4, 7 and 11,
When a jam occurs, the recording paper existing in front of the image forming unit remains blank and can be reused automatically by feeding this recording paper back to the paper feeding unit. Can be reduced.

According to the fifth aspect of the present invention, it is not necessary to unnecessarily stop the conveyance of the recording paper existing after the jam occurrence place, and conversely, if the recording paper in the middle of printing is stopped. Since improper printing occurs, recording paper after printing or during printing is completely printed and discharged, and then stopped, so that waste of recording paper due to a jam can be reduced.

According to the sixth aspect of the present invention, the paper other than the jam-corresponding paper is immediately discharged, so that when the jam paper is taken out manually, it is difficult to know which is the jam paper. can do.

According to the invention described in claims 8 to 10,
By removing only the jammed paper and then transporting or ejecting the non-jammed paper existing in the transport path to any position, it is not necessary to manually remove all the recording paper, thus producing copy work. You can improve your sex.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram centering on a recording paper conveyance path of an image forming apparatus according to a first embodiment of the present invention.

FIG. 2 is a schematic configuration diagram centering on a recording paper conveyance path of an image forming apparatus according to a second embodiment of the present invention.

FIG. 3 is a schematic configuration diagram in the vicinity of a sheet feeding unit of an image forming apparatus according to a third embodiment of the present invention.

FIG. 4 is a schematic configuration diagram of a main body side plate portion of an image forming apparatus according to a fourth embodiment of the present invention.

FIG. 5 is a schematic configuration diagram centering on a recording paper conveyance path of a conventional image forming apparatus.

[Explanation of symbols]

 1 Paper Feeding Section 2 Paper Feeding Conveying Path 3 Transfer Belt 12 Ejecting Conveying Path 13 Paper Ejecting Section 21 First Drive System 22 Second Driving System 23 Third Driving System 25 First Emergency Paper Ejection Tray 27 Second Emergency Ejection Paper tray

Claims (11)

[Claims] 1. An image forming apparatus using a cut sheet as a recording sheet and having a conveyance path in which a plurality of recording sheets are present in the conveyance path during continuous printing, in which the recording sheet is fed and conveyed in the conveyance path. An image forming apparatus characterized in that a drive system of a roller group for a vehicle is divided into a plurality of parts. 2. The image forming apparatus according to claim 1, wherein when a recording paper jam occurs in the conveyance path, the conveyance of the jam-corresponding paper is immediately stopped, and depending on the place where the jam occurs, The image forming apparatus is characterized in that the non-jammed paper existing in the conveyance path is conveyed to an arbitrary position and then the operation is stopped. 3. The image forming apparatus according to claim 1, further comprising an emergency paper discharge mechanism at an arbitrary position near the conveyance path. 4. The image forming apparatus according to claim 1, wherein the conveying roller on the upstream side of the image forming unit is provided so as to be capable of reverse rotation driving. 5. The image forming apparatus according to claim 2, wherein the non-jam paper existing on the paper discharge side from the place where the jam has occurred is discharged to a paper discharge tray. Forming equipment. 6. The image forming apparatus according to claim 2, wherein control is performed to eject non-jammed paper existing in the conveyance path from the emergency paper ejection mechanism according to a location where a jam has occurred. An image forming apparatus characterized by being opened. 7. The image forming apparatus according to claim 2, wherein the non-jam paper present in a section of the feeding path and the entrance of the image forming section in the feeding path is fed backward to the feeding portion. An image forming apparatus characterized in that control for discharging a sheet is performed. 8. An image forming apparatus that uses a cut sheet as a recording sheet and has a conveyance path in which a plurality of recording sheets exist in the conveyance path during continuous printing, and a recording sheet jam occurs in the conveyance path. In such a case, the control of temporarily stopping the transportation of all the recording papers in the transportation path and automatically transporting the recording papers existing in the transportation path to any position after the jammed paper is removed is performed. An image forming apparatus characterized by being performed. 9. The image forming apparatus according to claim 8, wherein after the jammed paper is removed, control is automatically performed to discharge the recording paper existing in the conveyance path to a paper discharge tray. An image forming apparatus characterized by. 10. The image forming apparatus according to claim 3 or 8, wherein after the jammed paper is removed, control is performed to automatically eject the recording paper existing in the transport path from the emergency paper ejection mechanism. An image forming apparatus, wherein: 11. The image forming apparatus according to claim 4, wherein after the jammed paper is removed, the recording paper existing in the section between the paper feed section and the image forming section entrance in the conveyance path is reversed. An image forming apparatus, wherein control is performed to convey and discharge a sheet to a sheet feeding unit.