JPH08211776A - Image forming device - Google Patents

Abstract

PURPOSE: To provide an image forming device where paper jammed in a state where it is caught by a fixing roll is easily taken out. CONSTITUTION: By opening a cover 30, releasing a movement preventing member 36 and rotating it in a direction shown by an arrow 36a, the paper 14 being carried is held between a 1st guiding member 28a and the member 36. Meanwhile, linked with the opening movement of the cover 30, a 3rd gear 32 is rotated in a direction shown by an arrow 32a, a 2nd gear 24 is rotated in a direction shown by an arrow 24a, and further not only a 1st gear 22 is rotated but also a heating roll 16 and a pressure roll 18 are respectively rotated in directions shown by arrows 16a and 18a so as to eject the paper 14. However, the paper 14 is held between the members 28a and 36, so that it can not be moved, and it is easily taken out because it overhangs in a loop state like the paper 14a shown by the broken line.

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 such as an electrophotographic copying machine or an electrophotographic printer which develops with a developer such as toner.

[0002]

2. Description of the Related Art Conventionally, an image forming apparatus using an electrophotographic system has been widely spread. This electrophotographic image forming apparatus normally charges a drum-shaped image carrier (photosensitive drum) uniformly, and emits light carrying information of an image recorded on a document to the photosensitive drum. To form a latent electrostatic image on the photoconductor drum, develop the latent electrostatic image with a developer (toner), transfer the developed image to paper, and place the paper on a pair of fixing rolls. It is a device that obtains a print (copy) image by fixing the transferred image by sandwiching it.

The fixing roll serves not only for fixing but also for carrying a sheet in the discharging direction. The sheet carried by the fixing roll is a discharging guide for guiding the sheet in the discharging direction and a discharging roll for discharging the sheet to the outside. It is discharged to the outside via. Also, the paper that is being conveyed by the fixing roll may cause a paper jam, and the fixing roll may stop while being sandwiched between the fixing rolls. A free cover is provided.

An image forming apparatus of a type has been proposed in which a knob for manually rotating the fixing roll is provided in order to easily take out a paper jammed in a state of being sandwiched by the fixing rolls (Japanese Patent Laid-Open No. HEI 3). -148684 and JP-A-6-35363). In the image forming apparatus of the type provided with this knob, when a paper jam occurs when the paper is sandwiched between the fixing rolls, the cover is opened and the knob is rotated to eject the paper jammed.
Some people try to pull out the paper without opening the cover and turning the knob when the paper is visible. In this case, the jammed paper may be torn, leaving a piece of paper in the machine, which may cause a paper jam, or may cause burns when you touch a high temperature part such as the fixing roll. There is.

[0005]

Therefore, the fixing roll is rotated in conjunction with the opening operation of the cover, and the leading edge of the paper jammed in the state of being sandwiched by the fixing roll is discharged to the cover side. A technique has been proposed for making it easier to take out the paper and preventing recurrence or burn of paper jam (see Japanese Patent Laid-Open No. 4-42280). However, even if the fixing roll is rotated in conjunction with the opening operation of the cover, if the leading edge of the paper fed by the rotation enters the discharge roll via the discharge guide, the leading end of the paper will be on the cover side. There is a problem that it is difficult to take out the paper because it has not been ejected to the.

In view of the above circumstances, it is an object of the present invention to provide an image forming apparatus capable of easily taking out a paper jammed in a state of being sandwiched between fixing rolls.

[0007]

An image forming apparatus of the present invention for achieving the above object forms a latent image on an image carrier, develops the latent image with a developer, and transfers the developed image to a transfer material. In an image forming apparatus that transfers a transferred image to a transfer material, (1) the transferred material is conveyed while fixing the developed image to the transferred material while sandwiching the transferred material to which the developed image is transferred, and when the transferred material has an abnormal conveyance. A pair of fixing rolls that stop rotating (2) A discharge guide that guides the transferred material conveyed from the pair of fixing rolls in the discharge direction (3) Discharge the transferred material guided by this discharge guide to the outside And the rotation of the transfer material is stopped when the transfer material is abnormally conveyed. (4) An openable / closable cover that covers the transfer material conveyance path downstream of the pair of fixing rolls in the transfer material conveyance direction. The above fixing roll and Driving means for driving the fixing roll so that the transferred material is conveyed in the discharging direction in conjunction with the opening operation of the cover after the rotation of the discharging roll is stopped. (6) The opening operation of the cover It is characterized in that it is provided with a movement preventing means which is interlocked and which is arranged on the downstream side of the pair of fixing rolls in the conveying direction of the transferred material to prevent the transfer material from moving.

[0008] Here, by the movement preventing means interlocking with the opening operation of the cover, the transfer material being conveyed is pressed against the discharge guide by the fixing roll,
It is preferable that the transfer material is prevented from moving. Further, it is preferable that the movement preventing means prevents the transfer material from moving by fixing the discharge roll in conjunction with the opening operation of the cover.

[0009]

According to the image forming apparatus of the present invention, when the cover is opened when the material to be transferred is jammed between the fixing rolls, the cover is interlocked with the opening operation of the cover, while the transfer means is driven by the driving means. The fixing roll is driven so that the material is transported in the discharge direction, and the movement of the transferred material is blocked by the movement blocking means at the downstream side of the fixing roller in the transfer material transport direction. For this reason, the transfer-target material that has caused the paper jam is discharged from the fixing roll, but the discharged transfer-target material cannot move from there, and as a result, the transfer-target material is transferred from the fixing roll in the transfer-target material transport direction. It becomes easy to take out by protruding in a loop shape in the transfer material conveyance path on the downstream side.

Here, in the case where the movement preventing means prevents the transfer material from moving by pressing the transfer material against the discharge guide in conjunction with the opening operation of the cover, the transfer material discharge guide. A portion between the portion pressed against and the portion sandwiched by the fixing rolls projects in a loop shape, which facilitates removal. Similarly, in the case where the movement preventing means prevents movement of the transferred material by fixing the discharge roll in conjunction with the opening operation of the cover, the movement of the transferred material is blocked by the discharge roll in the same manner. The transfer material overhangs in a loop between the fixing roll and the discharge roll, and can be easily taken out.

[0011]

Embodiments of the image forming apparatus of the present invention will be described below with reference to the drawings. In the image forming apparatus of each of the following examples, the structure from the formation of the latent image on the photosensitive drum to the fixing of the developed image on the paper is the image using the above-described conventionally known electrophotographic method. It is similar to the forming device. That is, the image forming apparatus of each embodiment is
As described above, the photosensitive drum is uniformly charged, and light carrying the information of the image recorded on the original is irradiated to the photosensitive drum to form an electrostatic latent image on the photosensitive drum. , The electrostatic latent image is developed with a developer (toner), the developed image is transferred to a sheet, and the transfer image is fixed by sandwiching the sheet between a pair of fixing rolls to print (copy).
An image forming apparatus for obtaining an image. A feature of the image forming apparatus of each embodiment is the structure for taking out the paper jammed in the state of being sandwiched between the fixing rolls. This point will be described below. [First Embodiment] FIG. 1 shows the structure of a portion of the image forming apparatus of the first embodiment for taking out a paper jammed in a state of being sandwiched between fixing rollers.

The image forming apparatus 10 is provided with a pair of fixing rolls 20 which are guided by the paper guide 12 and fix the developed image on the paper 14 onto which the developed image is transferred. The pair of fixing rolls 20 includes a fixing roll 16 for heating (rotating in a direction indicated by an arrow 16a, hereinafter referred to as a heating roll) and a heating fixing roll 16 in which a heater (not shown) for heating a developed image is incorporated. A fixing roll 18 (hereinafter referred to as a pressure roll) for pressurizing the paper 14 by sandwiching the paper 14 therebetween.
It rotates in the direction indicated by the arrow 18a). A first gear 22 is fixed to the longitudinal end portion of the pressure roller 18, and a second gear 24 that meshes with the first gear 22 rotatably in the direction indicated by the arrow 24a is provided in the apparatus main body. There is. Further, the apparatus main body is provided with a knob 26 that rotatably meshes with the second gear 24 in the direction indicated by the arrow 26a, and the knob 26 is configured to be manually rotatable in the direction indicated by the arrow 26a. . Further, the image forming apparatus 10 includes an openable / closable cover 30 that covers a portion of the sheet conveyance path downstream of the fixing roll 20 in the conveyance direction. The cover 30 includes a third gear 3 that rotates in a direction indicated by an arrow 32a in conjunction with the opening operation of the cover 30.
2 is fixed. This third gear 32 has a cover 30.
When it is closed, teeth are not formed on a part of its entire circumference so as not to mesh with the second gear 24,
On the other hand, when the cover 30 is opened, the teeth 32b are formed so as to interlock with the movement of the cover 30 and mesh with the second gear 24 to rotate the second gear 24. The first gear 22 described above,
The second gear 24 and the third gear 32 constitute an example of the driving means according to the present invention. Also, in the device body,
A movement prevention member (an example of movement prevention means referred to in the present invention) 36 is attached which is biased by a torsion spring 34 so as to rotate about a rotation shaft 36b in a direction indicated by an arrow 36a. The movement preventing member 36 is provided on the cover 3
When 0 is closed, the one end portion 36c comes into contact with the cover 30 so as not to rotate. The discharge guide 28 that guides the paper 14 in the discharge direction includes a first guide member 28a, a pair of second guide members 28b, and a selection member 28c.
It has. The selection member 28c selectively comes into contact with either one of the pair of second guide members 28b, and thereby the ejection direction of the paper 14 is determined.

Next, a procedure for taking out the paper 14 when the paper is jammed while the paper 14 is sandwiched between the fixing rolls 20 will be described. When the paper 14 causes a paper jam, the fixing roll 20 stops, and a warning lamp (not shown) or the like informs the user that the paper jam has occurred. Cover 30
Is opened in the direction indicated by the arrow 30a, the movement preventing member 36
Rotates in the direction indicated by the arrow 36a, and the paper 14 is
It is sandwiched between the guide member 28a and the movement preventing member 36. On the other hand, when the cover 30 is opened, the third gear 32 rotates in the direction indicated by the arrow 32a in conjunction with this opening operation, and this rotation causes the second gear 24 to rotate in the direction indicated by the arrow 24a. As the 1 gear 22 rotates, the heating roll 16 and the pressure roll 18 are respectively moved by the arrows 16a and 18a.
The sheet 14 is rotated in the direction indicated by a, and the sheet 14 is discharged. However, as described above, the sheet 14 cannot be moved because it is sandwiched between the first guide member 28a and the movement preventing member 36, and as a result, the sheet 14 is looped like the sheet 14a shown by the broken line. It becomes easy to take out by overhanging. Further, when the paper 14 is not sufficiently overhanging, the knob 26 may be manually rotated to overhang the paper 14 largely. As described above, according to the image forming apparatus 10 of the present exemplary embodiment, when a paper jam occurs in a state where the paper 14 is sandwiched between the fixing rolls 20, the paper 14 can be easily taken out by opening the cover 30. . [Second Embodiment] FIG. 2 shows a structure of a portion of the image forming apparatus of the second embodiment for taking out a paper jammed in a state of being sandwiched between fixing rolls. The same reference numerals are used.

The image forming apparatus 40 is provided with a rack gear 42 instead of the third gear 32 of the image forming apparatus 10 of the first embodiment shown in FIG. This rack gear 42
Is urged in the direction of arrow 44a by a spring 44,
When the cover 30 is closed, the cover 30 is in contact with the cover 30 and is stopped. Further, the rack gear 42 has no teeth formed in a part of its longitudinal direction so as not to mesh with the second gear 24 when the cover 30 is closed, while the cover 30 is opened. At this time, the teeth 42a are formed so as to mesh with the second gear 24 and rotate the second gear 24 in conjunction with the movement. Therefore, the third
It has the same function as the gear 32, and the paper 1
Cover 3 when a paper jam occurs when 4 is sandwiched
When 0 is opened, the image forming apparatus 10 of the first embodiment shown in FIG.
Similarly to the above, the paper 14 is extended in a loop shape like the paper 14b shown by the broken line and is easy to take out. [Third Embodiment] FIG. 3 shows the structure of a portion of the image forming apparatus according to the third embodiment for taking out a paper jammed in a state of being sandwiched between fixing rolls. The same reference numerals are used. In FIG. 3, the image forming apparatus is shown from the direction opposite to that of the image forming apparatus shown in FIGS. 1 and 2. Therefore, the arrangement of the cover 30 and the like are different from those of the cover 30 in FIGS. It is the opposite.

The image forming apparatus 50 includes a heating roll 1
A first gear 52 is fixed to the longitudinal end portion of 6, and a second gear 54 that meshes with the first gear 52 rotatably in the direction indicated by the arrow 54a is provided in the apparatus main body. The second gear 54 is configured to rotate in a direction indicated by an arrow 54a with the movement of a lever 66 described later. Further, in the main body of the apparatus, an arrow 56a is attached to the second gear 54.
A knob 56 that is rotatably engaged in a direction indicated by is provided, and the knob 56 is configured to be manually rotatable in a direction indicated by an arrow 56a. In addition, a pair of discharge rolls 5 is provided on the outlet side of the pair of second guide members 28b.
8, 60 are arranged. The first gear 52 fixed to the heating roll 16 and the discharge roll gears 58b and 60b are both configured to be driven by the drive gear 62. The rotation center shaft 62a of the drive gear 62 is rotatably supported by the drive gear support member 64, and the drive gear support member 64 is rotatably supported by the shaft 64a. An end portion of the drive gear support member 64 on the side opposite to the rotation center shaft 62a is connected to the lever 66 via a shaft 64b.
The lever 66 is urged by a spring 68 in the direction indicated by the arrow 68a, and is stopped in a state of contacting the cover 30 when the cover 30 is closed. The lever 66, the first gear 52, and the second gear 54 constitute an example of the driving means according to the present invention. Further, the lever 66 and the drive gear support member 64 described above constitute one example of the stopping means referred to in the present invention.

Next, a procedure for taking out the paper 14 when the paper is jammed while the paper 14 is sandwiched between the fixing rolls 20 will be described. When the paper 14 causes a paper jam, the fixing roll 20 stops, and a warning lamp (not shown) or the like informs the user that the paper jam has occurred. Cover 30
When is opened, the lever 66 moves in the direction indicated by the arrow 68a, and the shaft 64b moves in the direction indicated by the arrow 68a. Therefore, the drive gear support member 64 rotates about the shaft 64a in the direction indicated by the arrow 64c, and the drive gear 62 also moves in the direction indicated by the arrow 64c in accordance with this rotation, so that the first roll of the heating roll 16 is moved. The 1st gear 52 and the discharge roll gears 58b and 60b are disengaged from the drive gear 62. As a result, the discharge rolls 58 and 60 are fixed.
On the other hand, although the first gear 52 of the heating roll 16 and the drive gear 62 are disengaged from each other, the second gear 54 rotates in the direction indicated by the arrow 54a with the movement of the lever 66. It rotates in the direction indicated by 16a. As a result, the paper 14 is ejected from the pair of fixing rolls 20. However, as described above, the discharge roll 5
Since the sheets 8 and 60 are in a fixed state, the sheet 14 cannot be moved, and as a result, the sheet 14 overhangs in a loop shape like the sheet 14c shown by the broken line and can be easily taken out. Also,
When the paper 14 is not sufficiently projected, the knob 56 may be manually rotated to largely project the paper 14d as indicated by the broken line. As described above, according to the image forming apparatus 50 of the present exemplary embodiment, as in the image forming apparatuses of the first and second exemplary embodiments, when the sheet 14 is sandwiched between the fixing rolls 20 and paper jam occurs, The paper 14 can be easily taken out by opening the cover 30.

[0017]

As described above, according to the image forming apparatus of the present invention, the jammed paper can be easily pulled out in the form of a loop, and the following effects can be obtained. 1. 2. You can take out the jammed paper without touching the fixing roll and the high temperature area around it, and the safety is improved. 2. The time to take out jammed paper is shortened and the taking-out work is shortened. Since the jammed paper can be taken out without forcibly pulling it, part of the jammed paper does not remain in the device,
The paper jam caused by a part of this paper is not caused again.

[Brief description of drawings]

FIG. 1 is a schematic diagram showing a structure of a portion for taking out a paper jammed in a state of being sandwiched between fixing rolls in an image forming apparatus of a first embodiment of the present invention.

FIG. 2 is a schematic diagram showing a structure of a portion for taking out a paper jammed in a state of being sandwiched between fixing rolls in the image forming apparatus of the second embodiment of the present invention.

FIG. 3 is a schematic diagram showing a structure of a portion for taking out a paper jammed in a state of being sandwiched between fixing rolls in the image forming apparatus of the third embodiment of the present invention.

[Explanation of symbols]

 10, 40, 50 Image forming apparatus 14 Paper 20 Fixing roll 22, 52 First gear 24, 54 Second gear 28 Discharge guide 30 Cover 32 Third gear 62 Drive gear 64 Drive gear support member 66 Lever

Claims (3)

[Claims] 1. An image forming apparatus for forming a latent image on an image carrier, developing the latent image with a developer, and transferring the developed image to a transfer material. The transfer material having the developed image transferred thereto is sandwiched. The transfer material is conveyed while fixing the developed image to the transfer material, and the pair of fixing rolls is stopped from rotating when the transfer material is not conveyed properly, and the transfer target is conveyed from the pair of fixing rolls. A discharge guide that guides the material in the discharge direction, a discharge roll that discharges the transfer target material guided by the discharge guide to the outside, and rotation of the transfer material stops when the transfer target material is abnormally conveyed; and the pair of fixing rolls. Also covers the transfer material transport path on the downstream side in the transfer material transport direction, and an open / close cover that operates in conjunction with the opening operation of the cover after rotation of the fixing roll and the discharge roll is stopped due to a transport error. Transfer material is in the discharge direction A driving unit that drives the fixing roll so that the fixing roll is conveyed, and is arranged downstream of the pair of fixing rolls in the conveying direction of the transfer medium, which interlocks with the opening operation to prevent the transfer medium from moving. An image forming apparatus comprising: a movement preventing unit. 2. The movement preventing means prevents movement of the transferred material by pressing the transferred material being conveyed by the fixing roll against the discharge guide in conjunction with the opening operation. The image forming apparatus according to claim 1, wherein: 3. The image according to claim 1, wherein the movement preventing unit prevents the transfer material from moving by fixing the discharge roll in conjunction with the opening operation. Forming equipment.