JP2000044085A - Image forming device and jam releasing mechanism - Google Patents

Abstract

PROBLEM TO BE SOLVED: To easily take out recording papers considered to be the cause of jamming wen jamming takes place in an image forming device employing an electrophotography process. SOLUTION: Pressure in each space between the paper feeding roller 7 and the friction plate 8 of a paper feeding part 2, between the photosensitive drum 10 and the transcription roller 11 of a transcription part 3, and between the paired fixing rollers 13 and 14 of a fixing part 4, is adjusted while being linked with the angular displacement operation of a jam releasing lever 6. At the time of image forming, the jam releasing lever 6 is disposed to an HP position so as to allow respective members to abut against one another, and a recording paper is held by these members so as to be surely carried on. Besides, when jamming takes place, the jam releasing lever 6 is disposed to the positions of A, B and C so as to allow the respective members themselves to be separated stepwise, and a released portion is formed up at the optimum position in a carrying route so as to allow the recording paper to be easily taken out without being brought into contact with the various kinds of members. Therefore, operability can be enhanced.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a jam clearing mechanism of an image forming apparatus using an electrophotographic process such as a laser printer.

[0002]

2. Description of the Related Art An image forming apparatus using an electrophotographic process includes a paper feeding unit, a transfer unit, and a fixing unit. The paper feed unit has a paper feed roller and, for example, a friction plate, sandwiches the recording paper therebetween, and feeds and conveys the recording paper one by one. The transfer unit has a photosensitive drum as a carrier and a transfer roller. For example, an electrostatic latent image of an image to be formed is formed on the surface of the photosensitive drum, and the electrostatic latent image is developed by a developer such as toner in a developing unit to be visualized. The transfer unit sandwiches the recording paper from the paper supply unit between the photosensitive drum and the transfer roller, transfers a visual image to the recording paper, and conveys it. The fixing unit has a pair of fixing rollers, sandwiches the recording paper from the transfer unit between the rollers, fixes the transferred visual image to the recording paper by heat fusion or the like, and conveys it.

Conventionally, various countermeasures against recording paper conveyance failure, that is, jams have been proposed. In a relatively large image forming apparatus such as a copying machine, for example, a fixing unit is configured to be removable from the image forming apparatus, a knob for releasing pressure between a photosensitive drum of a transfer unit and a transfer roller is provided, or A knob is provided on the rotating shaft of the upper transport roller to manually rotate the roller. When a jam occurs, the operator first opens the front plate constituting the housing of the image forming apparatus. Next, check the position of the recording paper that is causing the jam that is reported by the output of the sensor, etc., and remove the fixing unit, release the pressure of the transfer unit, and By rotating the recording paper, the recording paper is discharged out of the apparatus. Thus, the jam is released.

On the other hand, a relatively small image forming apparatus such as a laser printer has recently been provided with a paper feeding section, a transfer section and a fixing section close to each other with respect to a relatively large image forming apparatus such as a copying machine. Thereby, the size of the device is further reduced. As a result, the recording paper transport distance between the paper supply unit, the transfer unit, and the fixing unit is shortened, and the recording paper takes a state of straddling each unit. In such a small-sized image forming apparatus, when a jam occurs, the operator first opens the front plate. Next, for example, by inserting a finger between the transport surface of the transport path and the recording paper and pulling out the recording paper that is disposed over the fixing unit and the transfer unit and causes a jam, Discharge outside the device. Thus, the jam is released.

For example, Japanese Unexamined Patent Publication No. Hei 7-157141 discloses a technique for providing a bend on a recording sheet with respect to a technique for clearing a jam in a fixing unit of an electrophotographic process. The missing recording paper is pulled out.

Japanese Patent Application Laid-Open No. 4-100372 relates to a technique for clearing a jam in a reading section and a recording section of a printer. It has a head unit in which a thermal head for recording an image and a contact sensor for reading an image are integrally provided, and the operation surface of the head unit is arranged upward. In addition, a transport mechanism is provided in a cover disposed above the head unit, and the transport mechanism is configured to be able to contact or separate from the working surface of the head unit by opening and closing the cover. The cover is opened, the transport mechanism is separated from the head unit, and the recording paper is taken out.

Japanese Patent Application Laid-Open No. 58-25763 discloses that
Regarding the technology for clearing the jam of a printer of a facsimile device equipped with an automatic document feeder, a technology has been disclosed in which the document release lever of the automatic document feeder is configured to be linked with the operation of the document release lever of the facsimile device. As a result, the pair of rollers for document conveyance are separated from each other, and the recording paper is taken out.

Japanese Unexamined Patent Publication (Kokai) No. 61-226458 discloses a technique for clearing a jam in a paper feeder, which describes contact and separation between a paper feed roller and a separation plate and contact and separation between a conveyance roller and a pinch roller. There is disclosed a technique which is performed by rotating an operation unit.

[0009]

SUMMARY OF THE INVENTION The above-mentioned Japanese Patent Application Laid-Open No. 7-15 / 1995
In Japanese Patent No. 7141, although a flexure is formed on the recording paper to make it easy to pull out, the operator inserts a finger into the apparatus in which various components are densely arranged to pull out the recording paper when the recording paper is pulled out. It is necessary to have a part, and there is a possibility of touching a high-temperature fixing part, resulting in poor operability. In addition, Japanese Unexamined Patent Publication
The techniques disclosed in Japanese Patent Application Laid-Open No. 100372, JP-A-58-25763, and JP-A-61-226458 are not particularly related to an image forming apparatus using an electrophotographic process. It does not remove a series of jams in.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a jam clearing mechanism which can easily take out a recording sheet causing a jam when the jam occurs in an image forming apparatus using an electrophotographic process.

[0011]

SUMMARY OF THE INVENTION According to the present invention, there is provided a paper feeding section for sandwiching a recording paper between a paper feed roller and a friction plate, feeding and transporting the recording paper one by one, and displaying an image to be formed. A transfer unit that sandwiches the recording paper from the paper supply unit between the carrier that holds the image and the transfer roller, transfers the developed image to the recording paper, and conveys the recording paper from the transfer unit between a pair of fixing rollers. A jam release mechanism for an image forming apparatus using an electrophotographic process, comprising: a jam release lever provided so as to be angularly displaceable; A jam release mechanism for an image forming apparatus, wherein a paper feed roller, a friction plate, a carrier, a transfer roller, and a pair of fixing rollers contact and separate from each other in conjunction with angular displacement of a lever.

According to the present invention, the recording paper is fed and conveyed one by one while being sandwiched between a paper feed roller and a friction plate constituting a paper feed unit. The fed recording paper is nipped and conveyed by a carrier constituting a transfer unit and a transfer roller. At this time, a visualized image of an image to be formed, for example, a toner image, is formed on the carrier, and the visualized image is transferred to recording paper. The recording paper to which the visual image has been transferred is nipped and transported by a pair of fixing rollers constituting a fixing unit. Here, the transferred visual image is fixed on the recording paper. Thus, an image is formed using the electrophotographic process. Here, in conjunction with the angular displacement operation of the jam release lever, between the members holding the recording paper, that is, between the paper feed roller and the friction plate of the paper feed unit, and between the carrier of the transfer unit and the transfer roller. , And the pressure between the pair of fixing rollers of the fixing unit is adjusted.

Therefore, when the recording paper is conveyed to form an image, the paper feed roller and the friction plate of the paper feed unit, the carrier and the transfer roller of the transfer unit, and the pair of fixing rollers of the fixing unit are respectively arranged. Abut The recording paper is reliably transported while being sandwiched by these members. When a recording paper jam occurs, the jam release lever is angularly displaced, and the paper feed roller and the friction plate of the paper feed unit, the carrier and the transfer roller of the transfer unit, and the pair of fixing rollers of the fixing unit are moved. Separate from each other. The recording paper causing the jam can be easily removed from the open part of the transport path caused by the separation of each member without touching the components of the high-temperature fixing unit and other members. Is improved.

Further, according to the present invention, the jam release lever can be disposed at first to fourth positions by angular displacement. When the jam release lever is disposed at the first position, the paper feed roller and the friction plate contact each other, When the transfer roller and the transfer roller are in contact with each other, and the pair of fixing rollers are in contact with each other and are located at the second position, the paper feed roller and the friction plate are separated from each other, the carrier and the transfer roller are in contact with each other, and the pair of When the fixing roller abuts and is located at the third position, the paper feed roller and the friction plate are separated, the carrier and the transfer roller are separated, and a pair of fixing rollers are abutted and located at the fourth position. In this case, the paper feed roller and the friction plate are separated from each other, the carrier is separated from the transfer roller, and the pair of fixing rollers are separated from each other.

According to the present invention, in conjunction with the angular displacement operation of the jam release lever, between the members holding the recording paper, that is, between the paper feed roller of the paper feed unit and the friction plate, the carrier of the transfer unit. And the transfer roller, and the pressure between the pair of fixing rollers of the fixing unit are adjusted in a plurality of stages.

When a recording sheet is conveyed to form an image, the jam release lever is located at the first position, and the sheet feeding roller and the friction plate of the sheet feeding section, the carrier and the transfer roller of the transfer section, and the fixing roller are fixed. The pair of fixing rollers contact each other, and the recording paper is reliably conveyed while being nipped by these members. When the jam release lever is angularly displaced from the first position to the second position when a recording paper jam occurs, only the paper feed roller of the paper feed unit and the friction plate are separated from each other, and the rest remains in contact. . When the jam release lever is angularly displaced from the second position to the third position, in addition to the separation between the paper feed roller of the paper feed unit and the friction plate, the carrier of the transfer unit and the transfer roller separate from each other. Other than that, it remains in contact. Further, when the jam release lever is angularly displaced from the third position to the fourth position, in addition to the separation between the paper feed roller of the paper feeding unit and the friction plate and the separation between the transfer body and the transfer roller, the fixing is performed. The pair of fixing rollers of the portion are separated from each other.

Therefore, the recording paper causing the jam can be easily taken out from the open portion of the appropriate transport path generated by the stepwise separation of the members, and the operability is improved. Only the transport path required for taking out the recording paper can be opened according to the occurrence of jams, so that wear and failure of each member can be minimized without wasting the transport path opening mechanism. it can.

In order to separate each member step by step,
It is preferable to set the fulcrum of opening the transport path in the transfer section and the fixing section.

Further, since the paper feed roller and the friction plate are separated from each other in the paper feed unit, the recording paper can be more easily taken out from the paper feed unit.

Further, it is possible to prevent the surface of the carrier from being damaged when the recording paper is taken out by separating the carrier from the transfer roller in the transfer section. Since the surface of the carrier that carries the visible image is less likely to be damaged, it is possible to suppress a decrease in the quality of the formed image.

The present invention also provides a jam detecting means provided in each of the paper feeding section, the transfer section and the fixing section, and a control means for controlling an amount of angular displacement of the jam releasing lever based on a detection result of the jam detecting means. And characterized in that:

According to the present invention, the amount of angular displacement of the jam release lever is controlled based on the result of the jam detection. For example, when the occurrence of a jam in the paper feeding unit is detected, the amount of angular displacement is controlled so that the jam release lever is located at the second position. When the occurrence of a jam in the transfer unit is detected, the amount of angular displacement is controlled so that the jam release lever is disposed at the third position. Further, when the occurrence of a jam in the fixing unit is detected, the amount of angular displacement is controlled so that the jam release lever is disposed at the fourth position. As described above, when a jam occurs, the angular displacement operation of the jam release lever is automatically controlled according to the jam occurrence position.

Therefore, when a jam occurs, an appropriate transport path is immediately opened without the operator manually moving the jam release lever. The operator can remove the jam only by removing the recording paper from the open portion, and the operability is further improved.

Further, according to the present invention, there is provided a recording paper detecting means for detecting the presence or absence of a recording paper being conveyed, and when the recording paper detecting means detects that there is no recording paper, the paper feed roller and the friction plate are separated from each other. Control means for controlling the amount of angular displacement of the jam release lever so that the carrier and the transfer roller are separated from each other, and the pair of fixing rollers are separated from each other, and disposing the jam release lever at the fourth position. I do.

According to the present invention, when there is no recording paper being conveyed, the amount of angular displacement is controlled so that the jam release lever is located at the fourth position. As a result, the paper feed roller and the friction plate separate, the carrier and the transfer roller separate, and the pair of fixing rollers separate. Therefore, the members are not unnecessarily pressed against each other, so that the deformation of the members such as the rollers can be suppressed.

Further, according to the present invention, an operation mode detecting means for detecting that the operation mode of the image forming apparatus is the energy saving operation mode, and the operation mode of the image forming apparatus is the energy saving operation mode by the operation mode detecting means. Is detected, the angular displacement of the jam release lever is controlled so that the paper feed roller and the friction plate separate, the carrier and the transfer roller separate, and the pair of fixing rollers separate. And control means for arranging at a fourth position.

According to the present invention, when the operation mode of the image forming apparatus is the energy saving operation mode, the amount of angular displacement is controlled so that the jam release lever is located at the fourth position. As a result, the paper feed roller and the friction plate separate, the carrier and the transfer roller separate, and the pair of fixing rollers separate. Therefore, the members are not unnecessarily pressed against each other, so that the deformation of the members such as the rollers can be suppressed.

Further, according to the present invention, there is provided a power supply switching means for supplying or interrupting power to the image forming apparatus, and when the power supply to the image forming apparatus is supplied by the power supply switching means, the paper feed roller and the friction plate come into contact with each other. And controlling the amount of angular displacement of the jam release lever so that the carrier is in contact with the transfer roller and the pair of fixing rollers is in contact with the transfer roller. When the power supply is cut off, the angular displacement of the jam release lever is controlled so that the paper feed roller and the friction plate separate, the carrier and the transfer roller separate, and the pair of fixing rollers separate. Control means for arranging the lever at the fourth position.

According to the present invention, when the power is turned off, the amount of angular displacement is controlled so that the jam release lever is located at the fourth position. As a result, the paper feed roller and the friction plate separate, the carrier and the transfer roller separate, and the pair of fixing rollers separate. Therefore, the members are not unnecessarily pressed against each other, so that the deformation of the members such as the rollers can be suppressed.

Further, the present invention is characterized in that it includes a driving member for manual rotation of a roller provided at an end in the rotation axis direction of the paper feed roller, the transfer roller and the fixing roller.

According to the present invention, the paper feed roller, the transfer roller, and the fixing roller can be manually rotated by the driving member. Therefore, when taking out the recording paper, each roller is manually driven to perform fine conveyance adjustment of the recording paper,
It can be more easily removed.

Further, according to the present invention, the jam release lever includes:
The angular displacement can be manually performed.

According to the present invention, the jam release lever can be manually angularly displaced. Therefore, when the recording paper is taken out, the lever is manually angularly displaced, and the position of the open portion of the transport path is finely adjusted, whereby the recording paper can be taken out more easily. Further, even when the power to the image forming apparatus is cut off, the recording paper can be taken out by manually moving the jam release lever.

[0034]

FIG. 1 is a view showing an image forming apparatus 1 having a jam release mechanism according to an embodiment of the present invention. The image forming apparatus 1 forms an image using an electrophotographic process, and is realized by, for example, a laser printer. The image forming apparatus 1 includes a paper feed unit 2, a transfer unit 3, and a fixing unit 4, which are configured to be housed inside a housing 5. Further, the image forming apparatus 1 includes a jam release lever 6 that can be angularly displaced outside the housing 5. Further, the image forming apparatus 1 is relatively small, and the length of the recording paper in the transport direction and the length from the paper feeding unit 2 to the fixing unit 4 are generally longer in the former.

The paper feed unit 2 includes a paper feed roller 7 and a friction plate 8, and the recording paper stored in a tray 9 provided outside the housing 5 is fed one by one from the top of the housing 5. The sheet is fed inside and transported to the transfer unit 3. The friction plate 8 is arranged below the sheet feeding roller 7 and generates friction for sheet feeding with the sheet feeding roller 2. The friction plate 8 includes the sheet feeding unit 2 and the transfer unit 3.
Further, it is rotatable about a rotation shaft 18 at an end on the downstream side in the recording paper conveyance direction toward the fixing unit 4. The friction plate 8 is urged to abut the suction roller 7 by a spring 19 fixed to a guide plate 15 for guiding the conveyance of the recording sheet from the sheet feeding unit 2 to the transfer unit 3. Further, a contact piece 17 is attached to the upstream end of the friction plate 8 in the recording paper transport direction. The contact piece 17 faces the outside of the housing 5,
The rotation bar 16 that contacts the angular displacement of the jam release lever 6 to the first position (HP; home position), the second position (A), the third position (B), and the fourth position (C) abuts.
The rotation bar 16 is attached to a rotation shaft 6 a of the jam release lever 6.

The transfer section 3 includes a photosensitive drum 10 and a transfer roller 11, and transfers a visual image to a recording sheet fed by the sheet feeding section 2 and conveys it. Photoconductor drum 10
Carries a visible image of an image to be formed on the surface thereof, for example, a toner image. For this purpose, the image forming apparatus 1 further includes a developing unit 12 arranged around the photosensitive drum 10. The developing unit 12 applies toner to an electrostatic latent image formed on the surface of the photoconductor drum 10 by a writing optical system (not shown) and develops the image. The transfer roller 11 is arranged and fixed in a recess 20 of the guide plate 15. Information board 15
Is rotatable about a rotation shaft 21 at the downstream end in the recording paper conveyance direction. The guide plate 15 is, for example, a housing 5
The transfer roller 11 is urged in a direction approaching the photosensitive drum 10 by a spring 22 fixed to the photosensitive drum 10. Note that the transfer roller 11 is configured to interlock with a change in the position of the guide plate 15.

The fixing unit 4 includes a pair of fixing rollers 13 and 14.
And fix the developed image transferred to the recording paper by heat fusion or the like, and convey it to the outside of the housing 5. One fixing roller 14 of the pair of fixing rollers 13 and 14 is arranged and fixed in the recess 24 of the support member 23. The support member 23 supports the fixing roller 14 and guides conveyance of the recording paper. The support member 23 is rotatable around a rotation shaft 33 at an end on the downstream side in the recording paper conveyance direction.
Note that the fixing roller 14 is configured to interlock with a change in the position of the support member 23.

On the opposite side of the guide plate 15 and the support member 23 from the recording paper conveying side, cams 26 and 27 configured to be interlocked by a pulley 25 are arranged. The cam 2
The contact members 6 and 27 contact the contact members 28 and 29 provided on the guide plate 15 and the support member 23 on the surface opposite to the recording paper conveying surface.

A sensor 30 is provided near the contact piece 17. When the jam release lever 6 is located at the position C, the contact piece 17 pressed by the rotating bar 16 comes into contact with the sensor 30 and is turned on. Also, the paper feed unit 2,
Sensors 34 and 3 are provided near the transfer unit 3 and the fixing unit 4.
5 and 36 are provided respectively. The sensors 34, 35,
Reference numeral 36 is turned on when a recording paper conveyance failure occurs in each of the units 2, 3, and 4. These sensors 30, 34, 35,
The output from 36 is provided to the control unit 31. Control unit 3
1 drives the motor 32 based on the detection results of the sensors 30, 34, 35 and 36, and drives the motor 2 via the pulley 25.
8, 29 or the jam release lever 6 is controlled.

FIGS. 2 to 5 are views showing the state of the jam release lever 6 at each position. FIG. 2 shows the HP position, FIG.
4 shows the state at the A position, FIG. 4 shows the state at the B position, and FIG. 5 shows the state at the C position. First, a state in which the jam release lever 6 is located at the HP position will be described with reference to FIG. In this state, the outputs from the sensors 30, 34, 35, and 36 are all off, and the control unit 31 determines that the jam of the recording paper conveyance has not occurred. , 35, and 36, the control unit 31 drives the motor 32 to release the jam release lever 6 to the H level.
It is controlled to be arranged at the P position. The recording paper is fed to paper feed unit 2,
The images are conveyed in the order of the transfer unit 3 and the fixing unit 4 to form an image.

When the jam release lever 6 is located at the HP position, the rotation bar 16 does not contact the contact piece 17 and does not press the corresponding contact piece 17. Therefore, the friction plate 8 urged by the spring 19 is in contact with the paper feed roller 7 of the paper feed unit 2. At this time, the transfer roller 11 is in contact with the photosensitive drum 10 of the transfer unit 3, and the fixing roller 14 is in contact with the fixing roller 13 of the fixing unit 4.

The recording paper nipped and fed between the paper feed roller 7 and the friction plate 8 of the paper feed unit 2 is conveyed in the direction of the transfer unit 3 by the paper feed roller 7 rotating in the arrow S1 direction. . The recording paper conveyed along the guide plate 15 provided from the paper feeding unit 2 to the transfer unit 3 and reaching the transfer unit 3 is
The photoconductor drum 10 of the transfer unit 3 and the transfer roller 11 sandwich the photoconductor drum 10 and are conveyed in the direction of the fixing unit 4 by the photoconductor drum 10 and the roller 11 rotating in the directions of arrows S2 and S3, respectively. At this time, the toner image is transferred to the recording paper. The recording paper guided by the support member 23 and reaching the fixing unit 4 is nipped by the fixing rollers 13 and 14 of the fixing unit 4 and the rollers 1 rotating in the directions of arrows S4 and S5, respectively.
Conveyed by 3,14. At this time, the toner image on the recording paper is fixed by heat fusion or the like. Then, the paper is discharged from the housing 5.

Next, referring to FIG.
Will be described from the HP position to the A position. This state is a state in which only the output from the sensor 34 is turned on, and the control unit 31 determines that a jam of the recording paper conveyance has occurred in the paper feeding unit 2. Based on the detection results of the sensors 30, 34, 35, and 36, the controller 31 controls the motor 32 to drive the jam release lever 6 to the A position.

When the jam release lever 6 is moved from the HP position to the position A, the rotating bar 16 comes into contact with the contact piece 17 and presses the corresponding contact piece 17. As a result, the spring 19
The friction plate 8 rotates around the rotation shaft 18 due to the contraction, so that the friction plate 8 separates from the sheet feeding roller 7 of the sheet feeding unit 2. At this time, the transfer roller 11 is kept in contact with the photosensitive drum 10 of the transfer unit 3, and the fixing roller 14 is kept in contact with the fixing roller 13 of the fixing unit 4.

In this way, if the conveyance path of the paper feed unit 2 is opened and the leading end of the recording paper is a paper jam jam that is jammed by the paper feed member 2, the recording paper is pulled out of the paper feed unit 2 to cause the jam. It is released.

Next, referring to FIG.
Will be described from the A position to the B position. This state is in addition to the ON output from the sensor 34,
This is the state when the output from the sensor 35 is turned on and the control unit 31 determines that the recording sheet conveyance jam has occurred in the transfer unit 3. Each sensor 30, 34, 35, 3
Based on the detection result of No. 6, the control unit 31 drives the motor 32 to control the jam release lever 6 to be located at the B position.

When the jam release lever 6 is moved from the position A to the position B, the rotating bar 16 further presses the contact piece 17. As a result, the spring 19 is further contracted, and the friction plate 8 is further rotated about the rotation shaft 18. In addition, the spring 22 contracts and the guide plate 15 rotates about the rotation shaft 21, so that the friction plate 8 is moved from the paper feed roller 7 of the paper feed unit 2.
Are separated, and the transfer roller 11 is separated from the photosensitive drum 10 of the transfer unit 3. At this time, the fixing roller 14 is kept in contact with the fixing roller 13 of the fixing unit 4.

As a result, the transfer path of the transfer section 3 is opened in addition to the sheet supply section 2. The transfer paper 3 is the leading end of the recording paper.
If the jam has been jammed in a state where the jam has been advanced, the jam is released by pulling the recording paper from the paper feeding unit 2. At this time, the transfer roller 11 separates from the photosensitive drum 10, and a large gap is formed between these members. Therefore, even if the recording paper is taken off, the surface of the photosensitive drum 10 is not damaged.

Next, referring to FIG.
Will be described from the B position to the C position. This state is a state when all the outputs from the sensors 34, 35, and 36 are turned on, and the control unit 31 determines that the jam of the recording sheet conveyance has occurred in the fixing unit 4. Based on the detection results of the sensors 30, 34, 35, and 36, the control unit 31 controls the motor 32 to drive the jam release lever 6 to the C position.

When the jam release lever 6 is moved from the position B to the position C, the rotating bar 16 further presses the contact piece 17. At this time, the contact piece 17 contacts the sensor 30, and the sensor 30 is turned on. The control unit 31 controls the sensor 3
In response to the ON signal of 0, the motor 32 is driven to move the pulley 25 in the direction of arrow S6. With this, cam 2
6, 27 rotate. The cam surfaces of the cams 26 and 27 that contact the contact members 28 and 29 change from the first cam surfaces 26a and 27a to the second cam surfaces 26b and 27b. by this,
The support member 23 rotates about the rotation shaft 33, so that the friction plate 8 separates from the paper supply roller 7 of the paper supply unit 2, and the transfer roller 11 separates from the photosensitive drum 10 of the transfer unit 3. The fixing roller 14 separates from the fixing roller 13 of the fixing unit 4.

As a result, the transport path of the fixing unit 4 in addition to the sheet feeding unit 2 and the transfer unit 3 is opened. A jam that is jammed when the leading end of the recording paper has advanced to the fixing unit 4 or a jam that has been ejected and the rear end of the recording paper is jammed at the fixing unit 4 is output from the housing 5 to the outside. It can be released by taking off the paper. In addition, when the jam release lever 6 is disposed from the C position to another position, for example, the HP position, and the sensor 30 is turned off, the control unit 3
1 reversely drives the motor 32. This allows the pulley 25
Moves in the direction opposite to the arrow S6, and the cams 26 and 27 rotate in the opposite direction. The cam 2 which comes into contact with the contact members 28 and 29
The cam surfaces 6 and 27 change from the second cam surfaces 26b and 37b to the first cam surfaces 26a and 27a.

As described above, in conjunction with the angular displacement operation of the jam release lever 6, between the members for holding the recording paper, that is, between the paper feed roller 7 and the friction plate 8 of the paper feed unit 2, the transfer unit 3 The pressure between the photosensitive drum 10 and the transfer roller 11 and the pressure between the pair of fixing rollers 13 and 14 of the fixing unit 4 can be adjusted.

At the time of image formation, the paper feed roller 7 of the paper feed unit 2
, A friction plate 8, a photosensitive drum 10 and a transfer roller 11 of the transfer unit 3, and a pair of fixing rollers 13 and 1 of the fixing unit 4.
The recording papers 4 are brought into contact with each other, and the recording paper is reliably conveyed while being nipped by these members. When a jam occurs, the jam release lever 6 is angularly displaced, and the paper feed roller 7 of the paper feed unit 2 and the friction plate 8 are separated from each other. Further, the photosensitive drum 10 of the transfer section 3 and the transfer roller 11 are separated from each other. Further, the pair of fixing rollers 13 and 14 of the fixing unit 4 separate from each other. The recording paper causing the jam can be easily taken out from the open portion of the transport path generated by the separation of the members, and the operability is improved.

In particular, since the pressure between the above-mentioned members for holding the recording paper is adjusted in a plurality of steps in conjunction with the angular displacement operation of the jam release lever 6, the recording paper causing the jam is reduced. , Can be easily taken out from the open portion of the appropriate transport path generated by the stepwise separation of the members.
Further, since only the transport path required for taking out the recording paper can be opened in accordance with the occurrence state of the jam, the feed roller 7, the friction plate 8, the photosensitive member 8, and the photosensitive member can be opened without wasting the transport path opening mechanism. Wear and failure of the drum 10, the transfer roller 11, and the fixing rollers 13, 14 can be minimized.

For example, by separating the transfer roller 11 from the photosensitive drum 10 of the transfer section 3, it is possible to prevent the surface of the photosensitive drum 10 from being damaged when the recording paper is taken out. Photoconductor drum 10 carrying toner image
Since the surface of the image is hardly damaged, it is possible to suppress the deterioration of the quality of the formed image. Further, by separating the fixing roller 14 from the fixing roller 13 of the fixing unit 4,
The deformation of the fixing rollers 13 and 14 can be prevented.

Further, the control section 31 controls the sensors 34 and 3
Since the amount of angular displacement of the jam release lever 6 is controlled based on the detection results of 5, 36, that is, the jam occurrence position, the angular displacement operation of the jam release lever 6 is automatically controlled according to the jam occurrence position. Becomes Therefore, when a jam occurs, an appropriate transport path is immediately opened without the operator manually moving the jam release lever 6. The operator
The jam can be released only by removing the recording paper from the open portion, and the operability is further improved.

The control unit 31 controls each of the sensors 34 and 3
The presence or absence of a recording sheet being conveyed is determined based on the detection results of Nos. 5 and 36. When it is determined that there is no recording sheet, the friction plate 8 is separated from the paper feed roller 7 and the transfer roller is transferred from the photosensitive drum 10 to the transfer roller. In this example, the angular displacement of the fixing roller 14 is controlled so that the fixing roller 11 is separated from the fixing roller 13 and the fixing roller 14 is separated from the fixing roller 13, that is, the jam release lever 6 is arranged at the position C as shown in FIG. It belongs to the scope of the invention. In this case, since the members do not unnecessarily press against each other when an image is not formed, deformation of the rollers 7, 11, 13, and 14 can be suppressed.

In particular, an energy-saving operation mode is set as the operation mode of the image forming apparatus 1, and an operation mode detecting means is provided in the image forming apparatus 1 so that the detection result of the detecting means is given to the control unit 31. In the energy saving operation mode, the control unit 31 separates the friction plate 8 from the paper feed roller 7, separates the transfer roller 11 from the photosensitive drum 10, and separates the fixing roller 14 from the fixing roller 13. That is, an example in which the amount of angular displacement of the jam release lever 6 is controlled so that the jam release lever 6 is disposed at the position C as shown in FIG. 5 also belongs to the scope of the present invention. in this case,
Since the members do not needlessly press against each other, the rollers 7, 11,
Deformation of 13 and 14 can be suppressed. In the energy saving operation mode, the apparatus is in a standby state, and does not perform an image forming operation. Therefore, the lever 6 needs to be arranged at the position C in FIG. When the lever 6 is at a position other than the position C, the apparatus is performing image formation or preheating.

The image forming apparatus 1 includes a power supply circuit 37.
And a switch 38 for supplying or interrupting power to the device 1. The power supply / interrupt state of the switch 38 is supplied to the control unit 31, and when power is supplied to the image forming apparatus 1, the control unit 31 contacts the friction plate 8 with the paper feed roller 7 and The angular displacement of the transfer roller 11 is brought into contact with the drum 10 and the fixing roller 14 is brought into contact with the fixing roller 13, that is, the amount of angular displacement of the jam release lever 6 is controlled so as to be located at the HP position as shown in FIG. I do. When the power supply to the image forming apparatus 1 is cut off, the control unit 31 separates the friction plate 8 from the paper feed roller 7, separates the transfer roller 11 from the photosensitive drum 10, and separates the transfer roller 11 from the fixing roller 13. An example in which the amount of angular displacement of the fixing roller 14 is controlled so that the fixing roller 14 is separated, that is, the jam release lever 6 is disposed at the position C as shown in FIG. 5, also belongs to the scope of the present invention. In this case, when the power is cut off, the members do not needlessly come into pressure contact with each other.
The deformation of 11, 13, and 14 can be suppressed.

The rollers 7, 1 are attached to the ends of the sheet feeding roller 7, the transfer roller 11, and the fixing roller 14 in the rotation axis direction.
An example in which the knobs 39, 40, 41 for manual rotation of 1, 14 are provided also belongs to the scope of the present invention. Knob 3
9, 40, 41, the feed roller 7 and the transfer roller 1
1 and the fixing roller 14 can also be rotated manually, so that when the recording paper is taken out, the rollers 7, 11, and 14 are manually driven to perform fine conveyance adjustment of the recording paper, thereby making it easier to take out the recording paper. Can be.

Further, the jam release lever 6 can be manually displaced angularly. Therefore, when the recording paper is taken out, the lever 6 is manually angularly displaced, and the position of the open portion of the transport path is finely adjusted, whereby the recording paper can be taken out more easily. Further, even when the power of the image forming apparatus 1 is turned off, the jam release lever 6 can be manually moved to take out the recording paper.

[0062]

As described above, according to the present invention, in accordance with the angular displacement operation of the jam release lever, between the paper feed roller of the paper feed unit and the friction plate, the carrier of the transfer unit and the transfer roller are moved. During
The pressure between the pair of fixing rollers of the fixing unit is adjusted. Therefore, at the time of image formation, the respective members abut against each other, and the recording paper can be reliably conveyed while being nipped by these members. Further, when a jam occurs, the members are separated from each other, an open portion is formed in the transport path, and the recording paper can be easily taken out without touching various members. Therefore, operability is improved.

Further, according to the present invention, the pressure between the members is adjusted in a plurality of steps in conjunction with the angular displacement operation of the jam release lever. Therefore, when a jam occurs, the recording paper can be easily taken out from the open portion of the appropriate transport path generated by the stepwise separation of the members, and the operability is improved. Only the transport path required for taking out the recording paper can be opened in accordance with the occurrence state of the jam, so that the wear and failure of each member can be minimized without wasting the transport path opening mechanism. .

According to the present invention, the amount of angular displacement of the jam release lever is controlled based on the result of the jam detection. Therefore, when a jam occurs, the angular displacement operation of the jam release lever is automatically controlled according to the jam occurrence position. Since the appropriate transport path is immediately opened without the operator manually moving the jam release lever, the operator can release the jam simply by taking out the recording paper from the open portion, and the operability is further improved.

According to the present invention, when there is no recording paper being conveyed, the members are controlled so as to be separated from each other. Therefore, the members do not unnecessarily come into pressure contact with each other, and the deformation of the members such as the rollers can be suppressed.

According to the present invention, when the operation mode of the image forming apparatus is the energy saving operation mode, the members are controlled so as to be separated from each other. Therefore, the members do not unnecessarily come into pressure contact with each other, and the deformation of the members such as the rollers can be suppressed.

According to the present invention, when the power is turned off,
The members are controlled so as to be separated from each other. Therefore, the members do not unnecessarily come into pressure contact with each other, and the deformation of the members such as the rollers can be suppressed.

According to the present invention, since the driving member for manually rotating the paper feed roller, the transfer roller and the fixing roller is provided, each roller is manually driven to perform fine conveyance adjustment of the recording paper. The recording paper can be more easily taken out.

Further, according to the present invention, since the jam release lever can be manually angularly displaced, the lever is manually angularly displaced to finely adjust the position of the open portion of the transport path, so that the recording paper can be made easier. Can be taken out. Further, when the power of the image forming apparatus is shut off, the jam release lever can be manually moved to take out the recording paper.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating an image forming apparatus 1 including a jam release mechanism according to an embodiment of the present invention.

FIG. 2 is a diagram illustrating a state of a jam release lever 6 at an HP position.

FIG. 3 is a diagram showing a state of a jam release lever 6 at a position A.

FIG. 4 is a diagram showing a state of the jam release lever 6 at a position B.

FIG. 5 is a diagram showing a state of the jam release lever 6 at a position C.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Image forming apparatus 2 Paper feed part 3 Transfer part 4 Fixing part 5 Housing 6 Jam release lever 7 Paper feed roller 8 Friction plate 10 Photoconductor drum 11 Transfer roller 13, 14 Fixing roller 30, 34, 35, 36 Sensor 31 Control part 37 power circuit 38 switch 39,40,41 knob

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) G03G 15/16 G03G 15/16 3F343 15/20 107 15/20 107 (72) Inventor Norihide Kunikawa Osaka, Osaka (22) Inventor Takayuki Imagawa 22-22, Nagaikecho, Abeno-ku, Osaka, Osaka Prefecture F-term (reference) 2H032 AA00 BA01 BA11 BA15 BA21 2H033 AA37 BB35 BD09 CA06 CA22 CA34 2H072 AA02 AA12 AA16 AA17 AA29 AB25 BA03 3F048 AA02 AB01 BA14 BD03 EB12 EB22 3F049 AA04 DB02 DB06 LA02 LB03 3F343 FA02 FB02 FC10 JA01 JD08 JD33 KB05 KB06 KB08 LA04 LC10 LC20 LD20

Claims (8)

[Claims] 1. A paper feeding unit for sandwiching recording paper between a paper feeding roller and a friction plate, feeding and conveying the recording paper one by one, a carrier carrying a visualized image of an image to be formed, and a transfer A transfer unit that sandwiches the recording paper from the paper feed unit between the rollers, transfers the visual image to the recording paper, and conveys it. A recording paper from the transfer unit is sandwiched between a pair of fixing rollers, and the transferred visual image And a fixing unit for fixing and transporting the jammed recording paper to a recording sheet. The jamming canceling mechanism of the image forming apparatus by the electrophotographic process includes a jamming releasing lever provided to be angularly displaceable, and interlocking with the angular displacement of the jamming releasing lever. A paper feed roller, a friction plate, a carrier, a transfer roller, and a pair of fixing rollers contact and separate from each other. 2. The jam release lever can be disposed at first to fourth positions by angular displacement. When the jam release lever is disposed at the first position, the paper feed roller and the friction plate abut, and the carrier and the transfer roller are moved. And the pair of fixing rollers are in contact with each other, and when disposed at the second position, the paper feed roller and the friction plate are separated from each other, the carrier and the transfer roller are in contact, and the pair of fixing rollers are When the contact roller is disposed at the third position, the paper feed roller and the friction plate are separated from each other, the carrier and the transfer roller are separated from each other, and when the pair of fixing rollers are in contact with each other and disposed at the fourth position. 2. The jam release mechanism according to claim 1, wherein the paper feed roller and the friction plate are separated from each other, the carrier is separated from the transfer roller, and the pair of fixing rollers are separated from each other. 3. A jam detecting unit provided in each of the paper feeding unit, the transfer unit, and the fixing unit, and a control unit that controls an amount of angular displacement of the jam releasing lever based on a detection result of the jam detecting unit. The jam clearing mechanism for an image forming apparatus according to claim 1, wherein: 4. A recording paper detecting means for detecting the presence or absence of a recording paper being conveyed. When the recording paper detecting means detects that there is no recording paper, the paper feed roller and the friction plate are separated from each other, and And control means for controlling the amount of angular displacement of the jam release lever and disposing the lever at a fourth position so that the transfer roller and the transfer roller are separated from each other, and the pair of fixing rollers are separated from each other. A jam clearing mechanism for the image forming apparatus according to claim 1. 5. An operation mode detecting means for detecting that the operation mode of the image forming apparatus is the energy saving operation mode, and detecting that the operation mode of the image forming apparatus is the energy saving operation mode by the operation mode detecting means. The paper feed roller and the friction plate are separated from each other, the carrier and the transfer roller are separated from each other, and the pair of fixing rollers are separated from each other.
By controlling the amount of angular displacement of the jam release lever,
The jam clearing mechanism for an image forming apparatus according to claim 1, further comprising a control unit disposed at a position. 6. A power supply switching means for supplying or interrupting power to the image forming apparatus, and when power is supplied to the image forming apparatus by the power supply switching means, the paper feed roller and the friction plate come into contact with each other, and The jam release lever is controlled to the first position by controlling the amount of angular displacement of the jam release lever so that the transfer roller and the transfer roller come into contact with each other and the pair of fixing rollers come into contact with each other. When cut off, the paper feed roller and the friction plate separate, the carrier and the transfer roller separate, and a pair of fixing rollers separate.
By controlling the amount of angular displacement of the jam release lever,
The jam clearing mechanism for an image forming apparatus according to claim 1, further comprising a control unit disposed at a position. 7. The image forming apparatus according to claim 1, further comprising a driving member for manual rotation of a roller provided at an end of the sheet feeding roller, the transfer roller, and the fixing roller in the rotation axis direction. mechanism. 8. The jam clearing mechanism according to claim 1, wherein the jam clearing lever can be manually angularly displaced.