JPH05119650A - Fixing device for image forming device - Google Patents

Abstract

PURPOSE:To supply an Si oil from a 1st fixing roller to 2nd and 3rd fixing rollers. CONSTITUTION:A coating device 35 comes into contact with the 1st fixing roller 30 only at the time of forward rotation and fixing operation and is held parted therefrom at the time of backward rotation. On the contrary, cleaning rollers 33 come into contact with the fixing rollers 30, 31, 32 and clean the rollers at the time of the backward rotation and the fixing operation and are held parted therefrom so as not to hinder the supply of the Si oil between papers at the time of the forward rotation.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to cleaning of a fixing roller of a fixing device and prevention of toner adhesion in an image forming apparatus such as a full-color copying machine.

[0002]

2. Description of the Related Art Conventionally, in a fixing device in which three fixing rollers are vertically arranged, a cleaning roller for cleaning the surface of the fixing roller is provided for each fixing roller. Are fixed so that they are always in contact with the fixing roller.

Further, an application roller for applying Si oil to the fixing roller in order to prevent toner from adhering to the fixing roller is provided so as to contact the upper fixing roller.

As a substitute for the coating roller, Japanese Patent Application Laid-Open No. 51-98036 discloses means for coating a toner release agent.

Then, the cleaning roller is impregnated with Si oil to assist the application of the Si oil to the fixing roller, and the Si oil application from the application roller does not have to reach the middle and lower fixing rollers. To ensure mold releasability.

[0006]

However, in the conventional method, the impregnated Si oil does not come out due to dirt of the cleaning roller and Si oil withdrawal during life, and the Si oil applied from the upper fixing roller is cleaned. As a result, the roller absorbs the Si oil, so that the Si oil cannot reach the middle and lower fixing rollers.

Further, if the Si oil, the release agent, etc. are constantly supplied to the fixing roller, the consumption amount increases, and the fixing roller is depleted quickly, resulting in a shorter life than other parts.

In view of the above, it is an object of the present invention to provide a fixing device for an image forming apparatus, which can reduce the consumption of Si oil and achieve a long life.

[0009]

As shown in FIG. 1, a first fixing roller 30 and a second fixing roller 31 in contact with the first fixing roller 30 are provided.
Third fixing roller 32 in contact with the second fixing roller 31
And three sets of cleaning rollers 33 that contact the respective fixing rollers 30, 31, 32 to clean the surface thereof, and between the first fixing roller 30 and the second fixing roller 31 in the first image forming mode. Transport the transfer paper to
A transport body 3 that transports a transfer sheet between the second fixing roller 31 and the third fixing roller 32 in the second image forming mode.
4, the first fixing roller 30, the second fixing roller 31,
A coating device 35 for coating the toner adhesion preventing oil on at least one of the third fixing rollers 32.
And a moving device 36 for moving the three sets of cleaning rollers 33 to and from the fixing rollers 30, 31, 32, respectively.
The moving device 3 is configured to bring the cleaning roller 33 into contact with each of the fixing rollers 30, 31, 32 during the fixing operation.
And a control device 37 for driving and controlling the control unit 6.

According to a second aspect of the present invention, the coating device 35 is provided so as to be capable of separating and contacting, and the moving device 36 for separating and contacting the three sets of cleaning rollers 33 with respect to the respective fixing rollers 30, 31, 32.
And the coating device 3 at the time of the fixing operation or the pre-rotation thereof
5 is brought into contact with the fixing roller, and the cleaning roller 33 is attached to each fixing roller 3 during the fixing operation or the subsequent rotation.
A control device 37 for driving and controlling the coating device 35 and the moving device 36 is provided so as to come into contact with 0, 31, 32.

[0011]

When the image forming mode is started and the transfer sheet is conveyed into the fixing device, the moving device 36 operates to move the cleaning roller 33 to the fixing rollers 30, 31. , 32.

During the fixing operation, the fixing rollers 30 and 3
When cleaning of the fixing rollers 1, 32 is completed and the fixing operation is completed, the cleaning roller 33 causes the fixing rollers 30, 31,
It is separated from 32.

As described above, by bringing the cleaning roller 33 into contact with the fixing rollers 30, 31, 32 only when necessary, the oil consumption in the cleaning roller is reduced.

Moreover, since the cleaning roller 33 is separated from the fixing rollers 30, 31, 32 except during the fixing operation, the oil from the coating device 35 can easily rotate around the fixing rollers 30, 31, 32 throughout its life.

In the problem solving means according to the second aspect, when the image forming mode is started, the coating device 35 is brought into contact with the fixing roller. When the transfer sheet is conveyed into the fixing device, the moving device 36 operates to bring the cleaning roller 33 into contact with the fixing rollers 30, 31, 32.

During the fixing operation, the fixing rollers 30 and 3
The cleaning device 1 and 32 are cleaned, and when the fixing operation is completed, the coating device 35 is separated from the fixing roller during the subsequent rotation. When the image forming mode ends, the cleaning roller 33 is also separated from the fixing rollers 30, 31, 32.

As described above, the coating device 35 is
It is in contact with the fixing roller only during the fixing operation, and is separated during the post rotation. On the contrary, the cleaning roller 33 contacts the fixing roller for cleaning during the post-rotation and the fixing operation and separates during the pre-rotation so as not to interrupt the oil supply.

[0018]

1 is a side view of a fixing device showing an embodiment of the present invention, FIG. 2 is an overall schematic view of a color copying machine, FIG. 3 is a functional block diagram of a control device, and FIG. 4 is a case where a cleaning roller is separated. 5 is a diagram showing the fixing device, FIG. 5 is a diagram showing the fixing device when the cleaning roller is in contact, and FIG. 6 is a flow chart of the fixing operation.

As shown in FIG. 2, the color copying machine of the present embodiment has a transparent original placing table 1 on the upper surface of the machine frame F. An exposure optical system 2 is provided below the original placing table 1.
Is provided, and the exposure optical system 2 is provided on the original placing table 1
A light source lamp 2a for irradiating the original 3 placed thereon with light
, A plurality of reflecting mirrors 2b for guiding the reflected light from the original 3 onto the photoconductor 4 as shown by a chain line, an imaging lens 2c arranged on the optical path, and three primary colors of red, green and blue. And a color separation filter 2d having the above filter.

On the optical axis of the exposure optical system 2, a belt-shaped photosensitive member 4 made of an organic photosensitive member (OPC), which is irradiated with an optical image subjected to exposure scanning, is arranged. Four
Paper feed cassettes 6 and 7 containing the transfer paper 5 are disposed on the paper input side. Further, paper feed rollers 8 and 9 are provided on the upper surfaces of the paper feed cassettes 6 and 7, respectively.
Is discharged from the paper feed cassettes 6 and 7 and sent toward the intermediate transfer body 10.

Intermediate transfer member 1 from the paper feed rollers 8 and 9
A timing roller 11 is arranged on the sending side in the 0 direction, and the timing roller 11 is used for the intermediate transfer member 1.
It is designed to rotate in synchronization with 0.

The intermediate transfer member 10 is rotatably driven by the first to third rollers 12a, 12b, 12c, and is in pressure contact with the driving roller 13 which rotatably drives the photosensitive member 4. A transfer charger 14 is provided on the back surface side of the intermediate transfer body 10 in the portion where the drive roller 13 is pressed, and on the front surface side of the intermediate transfer body 10 at the installation portion of the third roller 13c. Transfer roller 15
Are arranged. A peeling plate 16, a conveyor belt 17, and a fixing device 18 are arranged in this order on the delivery side of the transfer roller 15.

The photosensitive member 4 irradiated with the reflected light from the exposure optical system 2 is driven to rotate by the driven roller 19 and the driving roller 13. Further, a charging charger 20 for charging the photosensitive member 4 and a discharging lamp 21 for discharging the photosensitive member 4 are provided on the outer periphery of the photosensitive member 4 on the side of the driven roller 19, and the photosensitive member 4 in the vicinity of the charging charger 20 is disposed. A cleaning device 2 which is a cleaning unit for removing the toner remaining on the photoconductor 4 is provided below
2 are provided.

The cleaning device 22 includes:
For example, a cleaning blade 22a made of urethane or the like
The cleaning blade 22 is provided with
A is pressed against the photoconductor 4 to scrape off the toner and the like remaining on the photoconductor 4.

In the vicinity of the central portion above the photoconductor 4, a black and white developing tank 23 is in non-contact with the photoconductor 4.
And developing tanks 24 to 26 for color are provided,
Yellow, magenta and cyan color developers are individually accommodated in the color developing tanks 24 to 26.

As shown in FIG. 1, the fixing device 18 is in contact with the first fixing roller 30, the second fixing roller 31 which is in contact with the first fixing roller 30, and the second fixing roller 31. The third fixing roller 32 and the respective fixing rollers 30, 3
1 and 32, and three sets of cleaning rollers 33 for cleaning the surface thereof, respectively, and between the first fixing roller 30 and the second fixing roller 31 in the color copy in the first image forming mode. Transport the transfer paper,
In black-and-white copying which is the second image forming mode, a conveying body 34 that conveys the transfer paper is provided between the second fixing roller 31 and the third fixing roller 32.

A coating device 35 for coating the toner adhesion preventing oil composed of Si oil is provided on the first fixing roller 30 so as to be detachable from the first fixing roller 30, and the three sets of cleaning rollers 33 are connected to the respective fixing rollers. A moving device 36 that separates and contacts 30, 30, and 32, and the coating device 35 is brought into contact with the fixing roller 30 during the fixing operation or the pre-rotation, and the cleaning roller 33 is fixed during the fixing operation or the post-rotation. A controller 37 for driving and controlling the coating device 35 and the moving device 36 is provided so as to come into contact with the rollers 30, 31, 32.

Each of the fixing rollers 30, 31, 32 is formed in a cylindrical shape, and a heater lamp 40 is mounted inside. Then, the first, second, and third fixing rollers 3 are sequentially arranged from the top.
0, 31, 32 are arranged and rotatably supported by the machine frame F.

A felt is wound around the outer periphery of the cleaning roller 33, and as shown in FIG. 4, the cleaning rollers 33 are integrally rotatably supported by a support frame 41, and the fixing rollers 30, 31, 32 are rotated. Followed and rotates.

The carrier 34 comprises the belt 17 and a rocking device (not shown) for vertically rocking the carrier belt 17 as shown in FIG.

The conveyor belt 17 comprises a pair of rollers 17
The belt 17 is wound around a and 17b, and the belt 17 is rotated by the rotation of the rollers 17a and 17b.

The oscillating device is a combination of a solenoid or a motor and a spring, and has an upper position to convey the transfer paper between the first fixing roller 30 and the second fixing roller 31 during full color copying. During black-and-white copying, it is switched to a lower position in which the transfer paper is conveyed between the second fixing roller 31 and the third fixing roller 32.

The coating device 35 is the most full color S
Since i oil is required, it is arranged above the first fixing roller 30, and each fixing roller 3 is arranged in the order of upper → middle → lower.
Si oil is applied to 0, 31, and 32 by coating, and a coating roller 42 in which a felt impregnated with Si oil is wound around the outer periphery, and a support body 43 that rotatably supports the coating roller 42, A cam 45 that swings the support body 43 around a support shaft 44. The cam 45 is rotationally driven by a motor (not shown). Note that the coating roller 42 is supplied with Si oil from a Si oil tank (not shown).

In FIG. 1, 46 is a peeling claw and 47 is a paper output roller.

As shown in FIGS. 4 and 5, the moving device 36 comprises a solenoid 50 for bringing the support frame 41 into contact with and away from the cleaning roller 33. The support frame 41 is formed with a pair of oblique grooves 52 to which a pair of upper and lower guide pins 51 formed on the machine frame F are engaged.
When 0 is turned on / off, the guide pin 51 is slid along the slant groove 52 of the support frame 41, and the support frame 41 is slanted.

The control device 37 is composed of a micro-computer provided in the copying machine, and as shown in FIG. 3, copying of the copying machine is performed by the output signals from the print switch 53, the pre-fixing jam detecting switch MS2 and the paper output detecting switch MS3. The copy cycle determination means 54 for determining which state the cycle is in, and the cam 45 of the coating device 35 when the fixing operation or the pre-rotation is determined to drive the coating roller 42 to the first fixing roller. When the fixing operation or the post-rotation is determined, the solenoid 50 of the moving device 36 is turned on to move the cleaning roller 33 to the fixing rollers 30 and 3.
1 and 32 are provided with a cleaning operation means 56, and a transfer switching means 58 for placing the carrier 34 in an upper position in full color copying and in a lower position in black and white copying by an output signal from a color mode switching switch 57. ing.

The operation of the color copying machine having the above structure will be described below.

In the case of color copying, the copy switch is executed by pressing the print switch. This copy mode has a copy cycle in which yellow, magenta, and cyan are developed and transferred to the intermediate transfer body 10. When the copy mode is executed, the yellow copy cycle is executed first.

That is, the original 3 placed on the original table 1
The light is emitted from the light source lamp 2a, and the exposure scanning is performed. The reflected light from the original 3 is incident on the color separation filter 2d via the reflecting mirror 2b and the imaging lens 2c,
The color separation filter 2d separates the color components.

The light for each color component transmitted through each color filter of the color separation filter 2d by this exposure scanning is charged by the charging charger 2.
The photosensitive member 4 uniformly charged at 0 is irradiated, and the photosensitive member 4 is exposed at the portion A. As a result, a yellow electrostatic latent image corresponding to the image of the original 3 is formed on the photoconductor 4.
After that, the above-mentioned electrostatic latent images are visualized by being developed with the developer supplied from the developing magnet roller at the facing portion of the developing tank 24 having the yellow developer which is the complementary color of the color separation filter 2d. , Becomes a toner image. Then, this toner image is transferred to the intermediate transfer member 10 by the transfer charger 14.

When the yellow copying cycle is completed, the photoconductor 4 is cleaned by the cleaning device 22 and discharged by the discharge lamp 21. Then, in the same copy cycle, the magenta and cyan toner images are transferred to the intermediate transfer body 10.

When each copy cycle is executed, the toner image for each color component is transferred to the same position on the intermediate transfer member 10 by the transfer charger 14, and the toner for each color component is overlaid and completed. One toner image is formed.

On the other hand, the transfer papers 5 accommodated in the paper feed cassettes 6 and 7 are fed one by one to the timing roller 11 by the paper feed rollers 8 and 9, and the timing roller 11 is synchronized with the intermediate transfer body 10. The transfer paper 5 is conveyed between the intermediate transfer body 10 and the transfer roller 15. The transferred transfer paper 5 is
After the toner image on the intermediate transfer body 10 is transferred by the transfer roller 15, it is separated from the intermediate transfer body 10 by the peeling plate 16 and introduced into the fixing device 18 by the transport belt 17.

During this period, the copy cycle determining means 54 determines that the fixing is not yet completed, and the applying roller operating means 55 rotates the cam 45 to bring the applying roller 42 into contact with the first fixing roller 30. On the other hand, the cleaning operation means 56
The solenoid 50 is turned on to separate the cleaning roller 33 from the fixing rollers 30, 31, 32.

Then, Si oil is supplied from the application roller 42 to the first fixing roller 30, and the rotation of the fixing roller causes the Si oil to be transferred from the first fixing roller 30 to the second fixing roller 31 and the third fixing roller 32. Go around.

When the transfer sheet is conveyed into the fixing device by the conveying belt 17 switched to the upper position, the pre-fixing jam detection switch MS2 detects the presence of the sheet, and the copy cycle determining means 54 detects the output signal. Determines that the fixing operation has started.

Then, the solenoid 50 is turned off by the cleaning operation means 56, and the cleaning roller 33 comes into contact with the fixing rollers 30, 31, 32. Then, the transfer paper 5 passes between the first fixing roller 30 and the second fixing roller 31, whereby the color toner image is fixed,
The paper is discharged to the outside by the paper output roller 47.

At this time, the paper output detection switch MS3 detects that there is no paper in the fixing device, and the copy cycle judgment means 54 judges that the fixing operation is completed based on the output signal, and the cleaning operation means 56 causes the cleaning roller 33 to finish. Are separated from the fixing rollers 30, 31, 32. And
When the transfer sheet is conveyed again into the fixing device, the cleaning roller 33 is brought into contact with the fixing roller.

After the copy cycle is completed, the fixing roller 3
When 0, 31, 32 rotate backward, the copy cycle determination means 54 determines this, the coating roller 42 separates from the first fixing roller 30, and the cleaning roller 33 contacts each fixing roller 30, 31, 32. To do.

As described above, the coating device 35 is
The first fixing roller 30 is contacted only when the paper is passed, and it is separated when the post-rotation is performed. On the contrary, the cleaning roller 33
Does not interfere with the supply of Si oil by performing contact with the fixing roller for cleaning during post-rotation and paper passage, and separating during pre-rotation and between paper sheets.

Therefore, by bringing the cleaning roller into contact with the fixing roller only when necessary, the consumption of Si oil in the cleaning roller is reduced, and the life of the coating device 35 can be extended.

Moreover, since the cleaning roller is separated, the Si oil from the coating device 35 can easily reach the fixing rollers throughout its life.

Further, since the coating device 35 is brought into and out of contact with the fixing roller, the Si oil is not constantly supplied to the fixing roller, the supply amount of the Si oil can be reduced, and the Si oil in the life can be reduced. Depletion can be prevented.

The present invention is not limited to the above embodiment, and it goes without saying that many modifications and changes can be made to the above embodiment within the scope of the present invention.

In the present embodiment, the coating device 35 is provided for the first fixing roller 30, but it may be provided for another fixing roller, or a plurality of coating devices may be provided instead of one.

[0056]

As is apparent from the above description, claim 1
According to the invention described above, the applying device for applying the toner adhesion preventing oil to the fixing roller and the moving device for moving the cleaning roller to and from the fixing roller are provided, and the cleaning roller is fixed to each fixing roller during the fixing operation. By controlling the drive of the moving device so as to contact the roller,
The cleaning roller can be brought into contact with the fixing roller only when necessary, the oil consumption in the cleaning roller is reduced, and the life of the coating device can be extended.

Moreover, the separation of the cleaning roller makes it easier for the oil from the coating device to travel to each fixing roller throughout its life.

According to the second aspect of the present invention, the coating device is provided so as to be able to come into contact with and separate from the fixing device, and the moving device that makes the cleaning roller come into contact with the fixing roller is made to come into contact with the fixing roller. The coating device and the moving device are driven and controlled so as to bring the cleaning roller into contact with the respective fixing rollers during the fixing operation or the post-rotation, so that the coating device can fix the fixing roller only during the pre-rotation and the fixing operation. The cleaning roller comes into contact with the fixing roller during the post-rotation and the fixing operation to perform cleaning, and the cleaning roller is separated during the pre-rotation and between the papers to prevent the oil supply from being interrupted.

Moreover, since the oil is not constantly supplied from the coating device to the fixing roller, the amount of oil supplied can be reduced, and the depletion of oil during life can be prevented.

[Brief description of drawings]

FIG. 1 is a side view of a fixing device showing an embodiment of the present invention.

FIG. 2 is an overall schematic view of a color copying machine.

FIG. 3 is a functional block diagram of a control device.

FIG. 4 is a diagram showing the fixing device when the cleaning roller is separated.

FIG. 5 is a diagram illustrating a fixing device when a cleaning roller is in contact with the fixing device.

FIG. 6 is a flow chart of a fixing operation.

[Explanation of symbols]

 30 1st fixing roller 31 2nd fixing roller 32 3rd fixing roller 33 Cleaning roller 34 Conveying body 35 Coating device 36 Moving device 37 Control device

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Katsuhiro Nagayama 22-22 Nagaike-cho, Abeno-ku, Osaka-shi, Osaka Within Sharp Corporation (72) Yasutaka Maeda 22-22 Nagaike-cho, Abeno-ku, Osaka, Osaka Within the corporation

Claims (2)

[Claims] 1. A first fixing roller, a second fixing roller in contact with the first fixing roller, a third fixing roller in contact with the second fixing roller, and a third fixing roller in contact with each fixing roller. Three sets of cleaning rollers for cleaning the surface are provided, the transfer sheet is conveyed between the first fixing roller and the second fixing roller in the first image forming mode, and the second fixing is performed in the second image forming mode. In a fixing device of an image forming apparatus in which a conveying body that conveys a transfer sheet is provided between a roller and a third fixing roller, at least one of the first fixing roller, the second fixing roller, and the third fixing roller is used. An application device is provided for applying the toner adhesion preventing oil to the fixing roller, a moving device for separating and contacting the three cleaning rollers with respect to each fixing roller, and the cleaning device for fixing operation. And a controller for driving and controlling the moving device so as to bring the roller into contact with each fixing roller. 2. A first fixing roller, a second fixing roller in contact with the first fixing roller, a third fixing roller in contact with the second fixing roller, and a third fixing roller in contact with each of the fixing rollers. Three sets of cleaning rollers for cleaning the surface are provided, the transfer sheet is conveyed between the first fixing roller and the second fixing roller in the first image forming mode, and the second fixing is performed in the second image forming mode. In a fixing device of an image forming apparatus in which a conveying body that conveys a transfer sheet is provided between a roller and a third fixing roller, at least one of the first fixing roller, the second fixing roller, and the third fixing roller is used. An applicator for applying toner adhesion preventing oil to the fixing roller is provided so as to be able to come into contact with and separate from the fixing roller, and a moving device for bringing the three sets of cleaning rollers into contact with the fixing roller.
A controller for driving and controlling the coating device and the moving device so that the coating device is brought into contact with the fixing roller during the fixing operation or the pre-rotation, and the cleaning roller is brought into contact with the respective fixing rollers during the fixing operation or the post-rotation. The fixing device is provided with.