JP4894474B2 - Fixing apparatus and image forming apparatus - Google Patents

Description

  The present invention relates to an image forming apparatus using an electrophotographic system, for example.

Conventionally, many proposals have been made for an image forming apparatus used for fixing an image on a conveyed recording material and a fixing apparatus used for such an image forming apparatus.
As a conventional technique described in the publication, there has been proposed a fixing device having a configuration in which a fixing belt that rotates together with the fixing roller is stretched around the fixing roller, and the transferred paper that is conveyed between the fixing rollers is guided by the fixing belt. (See Patent Document 1). This document describes that when such a fixing device is used, the sheet can be guided between the fixing rollers with almost no rubbing of an unfixed image.
Similarly, as a prior art described in the publication, a sliding member between the sliding member and the fixing film is reduced by disposing a lubricant application member that contacts the inner surface of the fixing film that contacts the supporting member. A heating device capable of reducing torque has been proposed (see Patent Document 2).

Japanese Patent No. 2769727 JP 2002-023534 A

  An object of the present invention is to provide, for example, a fixing device that can reduce the possibility that sliding oil is transferred to the outer surface side of a fixing member to cause image defects.

  For this purpose, the fixing device of the present invention includes a fixing belt, a fixing member provided inside the fixing belt, a pressure member disposed so as to press against the fixing member, a fixing member, and a fixing member. A pressing member that is arranged to press the outer surface of the fixing belt against the pressure member in the vicinity of the downstream side of the pressure contact portion with the pressure member, and that supplies a lubricant to the sliding surface with the fixing belt; And a first cleaning member that cleans the surface of the fixing belt after the toner image is fixed on the recording material and a surface that contacts the first cleaning member to clean the surface of the first cleaning member. A second cleaning member, wherein the width of the second cleaning member is equal to or greater than the width of the first cleaning member, and the width of the first cleaning member is larger than the width of the fixing belt. There.

  The fixing belt further includes a transfer preventing member that prevents the lubricant adhering to the inner surface of the fixing belt from transferring to the outer surface side of the fixing belt at an end in the width direction of the fixing belt. it can. The surface hardness of the first cleaning member may be lower than the outer surface hardness of the fixing belt. Further, the second cleaning member may be characterized by being impregnated with cleaning oil.

  The fixing device of the present invention includes a fixing belt, a fixing member provided inside the fixing belt, a pressure member arranged to press against the fixing member, and a fixing member and a pressure member. In the vicinity of the downstream side of the press contact portion, the pressing member is arranged so as to press the outer surface of the fixing belt against the pressing member, and a lubricant is supplied to the sliding surface with the fixing belt, and the outer surface of the fixing belt. A first cleaning member that is disposed in contact and cleans the surface of the fixing belt after the toner image is fixed on the recording material; and a second cleaning that is disposed in contact with the first cleaning member and cleans the surface of the first cleaning member. A first cleaning member to which a lubricant that transfers from the inner surface side to the outer surface side of the fixing belt is attached, and a second cleaning member that transfers the lubricant to the first cleaning member It is characterized by depositing.

  On the other hand, the image forming apparatus of the present invention includes a toner image forming unit that forms a toner image, a transfer unit that transfers a toner image formed by the toner image forming unit onto a recording material, and a toner that is transferred onto the recording material. Fixing means for fixing an image on a recording material, the fixing means comprising: a fixing belt; a fixing member provided inside the fixing belt; and a pressure member arranged to press against the fixing member; A pressing member disposed near the downstream side of the pressure contact portion between the fixing member and the pressure member so as to press the outer surface of the fixing belt against the pressure member, and a lubricant is supplied to the sliding surface with the fixing belt. A first cleaning member that is disposed in contact with the outer surface of the fixing belt, cleans the surface of the fixing belt after the toner image is fixed on the recording material, and is disposed in contact with the first cleaning member. Surface of And a second cleaning member for cleaning, the width of the second cleaning member is not less than the width of the first cleaning member, the width of the first cleaning member, it is characterized in greater than the width of the fixing belt.

According to the fixing device of the first aspect of the present invention, when the lubricant used on the inner surface side of the fixing belt is to be transferred to the outer surface side of the fixing belt, the lubricant to be transferred is first cleaned. The member and the second cleaning member can be removed. That is, a fixing device is provided that can reduce image defects caused by the lubricant transferring to the outer surface side of the fixing member.
According to the second aspect of the present invention, it is possible to further suppress the lubricant used on the inner surface side of the fixing belt from transferring to the outer surface side of the fixing belt as compared with the case where the configuration of the present invention is not provided. (The risk of image defects based on the lubricant is further reduced).
According to the third aspect of the present invention, it is possible to further reduce the possibility that the outer surface of the fixing belt for forming an image is damaged as compared with the case where the configuration of the present invention is not provided.
According to the fourth aspect of the present invention, the surface of the first cleaning member can be cleaned better than when the configuration of the present invention is not provided.
According to claim 5 of the present invention, as compared with the case where this configuration is not provided, the lubricant is more effectively prevented from transferring to the outer surface side of the fixing belt at the press contact portion between the fixing member and the pressure member. (The risk of image defects based on the lubricant is further reduced).
According to the sixth aspect of the present invention, there is provided an image forming apparatus capable of satisfactorily reducing image defects caused by the seepage of the lubricant onto the surface of the fixing belt.

Embodiments of the present invention will be described below in detail with reference to the accompanying drawings.
FIG. 1 is a schematic configuration diagram illustrating an image forming apparatus to which the exemplary embodiment is applied. The image forming apparatus shown in FIG. 1 is an intermediate transfer type image forming apparatus generally called a tandem type, and a plurality of image forming units 1Y, 1M, 1C, and 1K on which toner images of respective color components are formed by electrophotography. The primary transfer unit 10 that sequentially transfers (primary transfer) the color component toner images formed by the image forming units 1Y, 1M, 1C, and 1K to the intermediate transfer belt 15, and the superimposed toner image transferred onto the intermediate transfer belt 15. Are provided with a secondary transfer unit 20 that collectively transfers (secondary transfer) to a paper P that is a recording material (recording paper), and a fixing device 60 that fixes the secondary transferred image onto the paper P. Moreover, it has the control part 40 which controls operation | movement of each apparatus (each part).

  In the present embodiment, each of the image forming units 1Y, 1M, 1C, and 1K has a charger 12 that charges the photosensitive drum 11 around the photosensitive drum 11 that rotates in the direction of arrow A, and the photosensitive drum 11. A laser exposure device 13 for writing an electrostatic latent image thereon (exposure beam is indicated by a symbol Bm in the drawing), development for accommodating each color component toner and making the electrostatic latent image on the photosensitive drum 11 visible with toner. 14, a primary transfer roll 16 that transfers each color component toner image formed on the photosensitive drum 11 to the intermediate transfer belt 15 in the primary transfer unit 10, and a drum cleaner 17 that removes residual toner on the photosensitive drum 11. , Etc. are sequentially arranged. These image forming units 1Y, 1M, 1C, and 1K are arranged in a substantially straight line from the upstream side of the intermediate transfer belt 15 in the order of yellow (Y), magenta (M), cyan (C), and black (K). Has been.

  The intermediate transfer belt 15 is circulated and driven at various speeds in the direction B shown in FIG. 1 by various rolls. As these various rolls, a drive roll 31 that is driven by a motor (not shown) having excellent constant speed and circulates the intermediate transfer belt 15, and an intermediate that extends substantially linearly along the arrangement direction of the photosensitive drums 11. A support roll 32 that supports the transfer belt 15, a tension roll 33 that functions as a correction roll that applies a constant tension to the intermediate transfer belt 15 and prevents meandering of the intermediate transfer belt 15, and a backup provided in the secondary transfer unit 20. A cleaning backup roll 34 provided in a cleaning section that scrapes off residual toner on the roll 25 and the intermediate transfer belt 15 is provided.

  The primary transfer unit 10 includes a primary transfer roll 16 that is disposed to face the photosensitive drum 11 with the intermediate transfer belt 15 interposed therebetween. The primary transfer roll 16 is placed in pressure contact with the photosensitive drum 11 with the intermediate transfer belt 15 in between, and the primary transfer roll 16 has a voltage (with negative polarity; the same applies hereinafter) having a polarity opposite to that of the toner. (Primary transfer bias) is applied. As a result, the toner images on the respective photosensitive drums 11 are sequentially electrostatically attracted to the intermediate transfer belt 15 so that the toner images superimposed on the intermediate transfer belt 15 are formed.

  The secondary transfer unit 20 includes a secondary transfer roll 22 disposed on the toner image carrying surface side of the intermediate transfer belt 15 and a backup roll 25. The backup roll 25 is disposed on the back side of the intermediate transfer belt 15 to constitute a counter electrode of the secondary transfer roll 22 and is disposed in contact with a metal power supply roll 26 to which a secondary transfer bias is stably applied. ing.

  On the other hand, the secondary transfer roll 22 is disposed in pressure contact with the backup roll 25 with the intermediate transfer belt 15 interposed therebetween. Further, the secondary transfer roll 22 is grounded, and a secondary transfer bias is formed between the secondary transfer roll 22 and the backup roll 25. The toner image is secondarily transferred onto the paper P conveyed to the transfer unit 20.

  Further, on the downstream side of the secondary transfer portion 20 of the intermediate transfer belt 15, an intermediate transfer belt that removes residual toner and paper dust on the intermediate transfer belt 15 after the secondary transfer and cleans the surface of the intermediate transfer belt 15. A cleaner 35 is provided so as to be able to contact and separate. On the other hand, on the upstream side of the yellow image forming unit 1Y, a reference sensor (home position sensor) 42 that generates a reference signal serving as a reference for taking image forming timings in the image forming units 1Y, 1M, 1C, and 1K. It is arranged. Further, an image density sensor 43 for adjusting image quality is disposed on the downstream side of the black image forming unit 1K. The reference sensor 42 recognizes a predetermined mark provided on the back side of the intermediate transfer belt 15 and generates a reference signal. Each image forming unit is instructed by an instruction from the control unit 40 based on the recognition of the reference signal. 1Y, 1M, 1C, and 1K are configured to start image formation.

  Further, in the image forming apparatus according to the present embodiment, as a paper transport system, a paper tray 50 that stores paper P, a pickup roll 51 that picks up and transports the paper P accumulated in the paper tray 50 at a predetermined timing, and a pickup A transport roll 52 that transports the paper P fed by the roll 51, a transport chute 53 that feeds the paper P transported by the transport roll 52 to the secondary transfer unit 20, and transported after being secondarily transferred by the secondary transfer roll 22. A conveyance belt 55 that conveys the paper P to be fixed to the fixing device 60 and a fixing inlet guide 56 that guides the paper P to the fixing device 60 are provided.

  Next, a basic image forming process of the image forming apparatus according to the present embodiment will be described. In the image forming apparatus as shown in FIG. 1, image data output from an image reading device (IIT) not shown or a personal computer (PC) not shown is subjected to predetermined image processing by an image processing device (IPS) not shown. After being applied, the image forming operation is executed by the image forming units 1Y, 1M, 1C, and 1K. In IPS, the input reflectance data is subjected to predetermined image processing such as shading correction, position shift correction, brightness / color space conversion, gamma correction, frame deletion, color editing, moving editing, and other various image editing. Is done. The image data that has undergone image processing is converted into color material gradation data of four colors, Y, M, C, and K, and is output to the laser exposure unit 13.

  The laser exposure unit 13 irradiates the photosensitive drums 11 of the image forming units 1Y, 1M, 1C, and 1K, for example, with an exposure beam Bm emitted from a semiconductor laser in accordance with the input color material gradation data. Yes. In each of the photosensitive drums 11 of the image forming units 1Y, 1M, 1C, and 1K, the surface is charged by the charger 12, and then the surface is scanned and exposed by the laser exposure unit 13 to form an electrostatic latent image. The formed electrostatic latent images are developed as toner images of Y, M, C, and K colors by the developing devices 14 of the respective image forming units 1Y, 1M, 1C, and 1K.

  The toner images formed on the photosensitive drums 11 of the image forming units 1Y, 1M, 1C, and 1K are transferred onto the intermediate transfer belt 15 in the primary transfer unit 10 where the photosensitive drums 11 and the intermediate transfer belt 15 are in contact with each other. Is done. More specifically, in the primary transfer unit 10, a voltage (primary transfer bias) having a reverse polarity (plus polarity) to the charging polarity of the toner is applied to the base material of the intermediate transfer belt 15 by the primary transfer roll 16, and the toner image. Are sequentially superimposed on the surface of the intermediate transfer belt 15 to perform primary transfer.

  After the toner images are sequentially primary transferred onto the surface of the intermediate transfer belt 15, the intermediate transfer belt 15 moves and the toner image is conveyed to the secondary transfer unit 20. When the toner image is transported to the secondary transfer unit 20, in the paper transport system, the pick-up roll 51 rotates in accordance with the timing at which the toner image is transported to the secondary transfer unit 20, and the paper of a predetermined size is transferred from the paper tray 50. P is supplied. The paper P supplied by the pickup roll 51 is transported by the transport roll 52 and reaches the secondary transfer unit 20 via the transport chute 53. Before reaching the secondary transfer unit 20, the paper P is temporarily stopped, and a registration roll (not shown) rotates in accordance with the movement timing of the intermediate transfer belt 15 on which the toner image is carried. And the position of the toner image are aligned.

  In the secondary transfer unit 20, the secondary transfer roll 22 is pressed against the backup roll 25 via the intermediate transfer belt 15. At this time, the sheet P conveyed at the same timing is sandwiched between the intermediate transfer belt 15 and the secondary transfer roll 22. At this time, if a voltage (secondary transfer bias) having the same polarity (negative polarity) as the charging polarity of the toner is applied from the power supply roll 26, a transfer electric field is formed between the secondary transfer roll 22 and the backup roll 25. Is done. The unfixed toner image carried on the intermediate transfer belt 15 is collectively electrostatically transferred onto the paper P in the secondary transfer unit 20 pressed by the secondary transfer roll 22 and the backup roll 25. .

Thereafter, the sheet P on which the toner image has been electrostatically transferred is transported as it is while being peeled off from the intermediate transfer belt 15 by the secondary transfer roll 22, and transported downstream of the secondary transfer roll 22 in the sheet transport direction. It is conveyed to the belt 55. The transport belt 55 transports the paper P to the fixing device 60 at an optimal transport speed in accordance with the transport speed of the fixing device 60. The unfixed toner image on the paper P conveyed to the fixing device 60 is fixed on the paper P by being subjected to fixing processing by heat and pressure by the fixing device 60. Then, the paper P on which the fixed image is formed is conveyed to a paper discharge mounting portion (not shown) provided in the discharge portion of the image forming apparatus.
On the other hand, after the transfer to the paper P is completed, the residual toner remaining on the intermediate transfer belt 15 is conveyed along with the circulation of the intermediate transfer belt 15, and is transferred by the cleaning backup roll 34 and the intermediate transfer belt cleaner 35. 15 is removed from above.

Next, the fixing device 60 used in the image forming apparatus of the present embodiment will be described.
FIG. 2 is a side sectional view showing a schematic configuration of the fixing device 60 of the present embodiment. The fixing device 60 includes a fixing belt module 61 as an example of a heating member and a pressure roll 62 as an example of a pressure member disposed in pressure contact with the fixing belt module 61. Yes.
The fixing belt module 61 includes a fixing belt 610 as an example of a belt member, and a fixing roll 611 as an example of a fixing member that rotates and rotates the fixing belt 610 and heats a toner image formed on the paper P. And. The fixing belt module 61 includes a tension roll 612 that stretches the fixing belt 610 from the inside, and a cleaning module 613 that stretches the fixing belt 610 from the outside and cleans the surface of the fixing belt 610. . Further, the fixing belt module 61 is an area in which the tension roll 614 that stretches the fixing belt 610 from the inside between the fixing roll 611 and the tension roll 612, and the fixing belt module 61 and the pressure roll 62 are in pressure contact with each other. A tension roll 615 for tensioning the fixing belt 610 is provided on the downstream side of a certain pressure contact portion N. Further, the fixing belt module 61 is disposed adjacent to the fixing roll 611 in the vicinity of the downstream side of the press contact portion N, and is a pressing member as an example of a pressing member that presses the outer surface of the fixing belt 610 against the surface of the pressure roll 62. A pad 64 is provided.
A sliding oil supply member 620 that supplies sliding oil as an example of a lubricant is disposed between the fixing belt 610 and the pressing pad 64 in the vicinity of the inner surface side of the fixing belt 610. Good sliding with the pressing pad 64 is ensured.

  The cleaning module 613 is disposed in contact with the outer surface of the fixing belt, and includes a cleaning roll 613a as an example of a first cleaning member that cleans the surface of the fixing belt 610 on the downstream side of the press contact portion N, and a cleaning roll 613a. And a cleaning web 613b as an example of a second cleaning member that is disposed in contact with the cleaning roller 613a and cleans the surface of the cleaning roll 613a. The cleaning module 613 includes a press-contact roll 613c that presses the cleaning web 613b against the cleaning roll 613a, a feed-out roll 613d that feeds the cleaning web 613b, and a take-up roll 613e that winds the cleaning web 613b.

  The fixing belt 610 is a flexible endless belt that circulates at a linear speed of, for example, 250 mm / second, and is laminated on a base layer formed of polyimide resin having a thickness of 80 μm and on the surface side (outer peripheral surface side) of the base layer. An elastic body layer made of silicone rubber having a thickness of 160 μm and a release layer formed of a tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer resin (PFA) tube having a thickness of 30 μm as a release layer on the elastic body layer. It is composed of a multilayer structure in which mold layers are laminated. In this embodiment, the width of the fixing belt 610 is set to 340 mm. However, the configuration and size of the fixing belt 610 can be appropriately selected according to the apparatus design conditions such as the purpose of use and the use conditions. .

The fixing roll 611 is a cylindrical roll. The fixing roll 611 receives a driving force from a driving motor (not shown) and rotates in the direction of arrow C at a constant surface speed.
In addition, a halogen heater 616a is provided as a heating source inside the fixing roll 611, and the control unit 40 of the image forming apparatus is based on the measured value of the temperature sensor 617a arranged so as to be in contact with the surface of the fixing roll 611. (See FIG. 1) controls the surface temperature of the fixing roll 611.

  The tension roll 612 is also a cylindrical roll. A halogen heater 616b is disposed as a heating source inside the tension roll 612, and the surface temperature of the tension roll 612 is controlled by the temperature sensor 617b and the control unit 40 (see FIG. 1). . Therefore, the stretching roll 612 has a function of heating the fixing belt 610 as well as a function of stretching the fixing belt 610.

The cleaning roll 613 a is a roll that rotates (driven) with the progress of the fixing belt 610 by the frictional force with the surface of the fixing belt 610. The cleaning roll 613a is configured by forming a release layer made of a heat-resistant release material having a thickness of 50 μm on the surface of a cylindrical roll formed of aluminum having an outer diameter of 20 mm and a length of 355 mm.
Here, such a heat-resistant release material preferably has heat resistance and is excellent in releasability (water repellency) with respect to sliding oil. Specific examples of such a heat-resistant release material include a fluororesin (for example, PFA and polytetrafluoroethylene resin), a silicone resin, a polyacetal resin, and the like.

A halogen heater 616c as a heating source is disposed inside the cleaning roll 613a, and the surface temperature is controlled by the temperature sensor 617c and the control unit 40 (see FIG. 1). Accordingly, the cleaning roll 613a has a function of stretching the fixing belt 610, a function of cleaning the surface of the fixing belt 610, and a function of heating the fixing belt 610 from the outer surface.
In the present embodiment, the surface hardness of the cleaning roll 613 a is set lower than the outer surface hardness of the fixing belt 610.

The cleaning web 613b is a flexible belt-like member having a width of 375 mm, and is constituted by a single layer of nonwoven fabric impregnated with cleaning oil with an impregnation amount of 5 g / m ² . The nonwoven fabric used here is preferably a nonwoven fabric having heat resistance. The material is not particularly limited, and examples thereof include polyamide, polyimide, polyester, and mixtures thereof. The cleaning oil is not particularly limited, and silicone oil or the like can be used as appropriate.
Depending on the application of the image forming apparatus of the present embodiment, the cleaning web 613b may be configured using a material other than a non-woven fabric, the cleaning web 613b may have a multilayer structure, and the amount of cleaning oil impregnation may be adjusted. Is possible.

The pressure contact roll 613c is formed by stacking an elastic layer made of silicone rubber sponge on a surface of a cylindrical roll made of aluminum having a diameter of 8 mm and a silicone rubber sponge (total diameter 20 mm).
The press roll 613c rotates (driven) with the progress of the cleaning web 613b. Here, the rotation direction of the pressure contact roll 613c may be the same direction as the rotation direction of the cleaning roll 613a or the reverse direction. Further, the rotational speed of the pressure contact roll 613c is not particularly limited, but is usually 0.03 mm / s to 0.5 mm / s.

The pressing pad 64 is a block member formed of a rigid body such as a metal such as SUS or aluminum or a resin and having a substantially arc shape in cross section. The pressure roll 62 is disposed across the entire axial direction of the fixing roll 611 at a position in the vicinity of the downstream side of the area where the pressure roll 62 is pressed against the fixing roll 611 via the fixing belt 610 (referred to as “roll pressing portion N1”). ing. The pressing pad 64 is installed so as to uniformly press the pressure roll 62 with a predetermined load over a predetermined width region via the fixing belt 610, and forms a “pressing pad press contact portion N2”. Yes.
Further, the tension roll 615 is disposed near the downstream side of the pressing pad 64 in the traveling direction of the fixing belt 610 so that the fixing belt 610 that has passed through the pressing pad 64 circulates smoothly toward the fixing roll 611.

  The pressure roll 62 is configured by laminating an elastic layer 622 made of silicone rubber and a release layer 623 made of a PFA tube in this order from the substrate side with a cylindrical roll 621 made of aluminum as a base. The pressure roll 62 is installed so as to be pressed against the fixing belt module 61, and rotates in the arrow E direction as the fixing roll 611 of the fixing belt module 61 rotates in the arrow C direction. The traveling speed is substantially the same as the surface speed of the fixing roll 611.

Next, a fixing operation in the fixing device 60 of the present embodiment will be described.
The sheet P on which the unfixed toner image is electrostatically transferred in the secondary transfer unit 20 (see FIG. 1) of the image forming apparatus is directed toward the pressure contact portion N of the fixing device 60 by the conveyance belt 55 and the fixing inlet guide 56 ( See FIG. 2: arrow F direction). The unfixed toner image on the surface of the paper P passing through the press contact portion N is fixed on the paper P mainly by pressure and heat acting on the roll press contact portion N1.

  Here, in the fixing device 60 of the present embodiment, heat acting on the pressure contact portion N is supplied mainly by the fixing belt 610. The fixing belt 610 is supplied through the tension roll 612 from the heat supplied from the halogen heater 616a disposed inside the fixing roll 611 through the fixing roll 611 and from the halogen heater 616b disposed inside the tension roll 612. It is configured to be heated by heat and heat supplied through a cleaning roll 613a from a halogen heater 616c disposed inside the cleaning roll 613a. Therefore, even when the heat energy is insufficient with only the fixing roll 611, the heat energy can be appropriately and quickly supplied from the stretching roll 612 and the cleaning roll 613a. Even at a high speed of 250 mm / s, a sufficient amount of heat can be secured. Further, when the heating performance of the stretching roll 612 and the cleaning roll 613a is sufficient, the fixing operation can be performed with the halogen heater 616a of the fixing roll 611 stopped.

  Since the fixing belt 610 is conveyed so as to be wound around the pressing pad 64 at the outlet of the pressing pad pressure contact portion N2, the conveying direction of the fixing belt 610 changes abruptly there. That is, since the fixing belt 610 moves along the outer surface of the pressing pad 64 having a substantially arc shape in cross section, the bending of the fixing belt 610 becomes large. Therefore, the paper P can be self-stripped from the fixing belt 610 by the stiffness of the paper P itself has. In this manner, the sheet P is peeled off from the fixing belt 610 at the time of exiting the pressing pad press contact portion N2, and is stably separated by curvature. The paper P separated from the fixing belt 610 is discharged to the outside by the paper discharge guide 65 and the paper discharge roll 66, and the fixing process is completed.

Next, the cleaning operation of the cleaning module 613 disposed in pressure contact with the fixing belt 610 will be described.
FIG. 3 is a schematic plan view when the cleaning roll 613a is observed from the X direction in FIG. In FIG. 3, the fixing belt 610, the cleaning roll 613a, and the cleaning web 613b have a relationship of (width of the fixing belt 610) <(width of the cleaning roll 613a) <(width of the cleaning web 613b). have. The cleaning roll 613a and the cleaning web 613b may have the same width.

In the fixing device 60 of the present embodiment, the pressing pad 64 is used as described above, and the fixing belt 610 and the pressing pad 64 slide to ensure good sliding between the fixing belt 610 and the pressing pad 64. Sliding oil is supplied to the surface. Such sliding oil tends to permeate (transfer) to the outer surface side of the fixing belt 610 through the side surface of the fixing belt 610 during the long-term operation of the fixing belt 610. Further, there may be a residue such as residual toner on the surface of the fixing belt 610 after the toner image is transferred onto the paper P at the press contact portion N.
The cleaning module 613 in the present embodiment acts to prevent such sliding oil transfer and to remove residues.

In other words, the cleaning roll 613 a that rotates in contact with the surface of the fixing belt 610 can act to adhere and collect residual toner remaining on the surface of the fixing belt 610.
The cleaning roll 613 a that is set wider than the fixing belt 610 and contacts the outer surface side of the fixing belt 610 is transferred from the inner surface side of the fixing belt 610 to the outer surface side of the fixing belt 610 through the end surface of the fixing belt 610. The sliding oil to be worked may be collected and attached when the sliding oil passes through the end face of the fixing belt 610.

The cleaning web 613b that rotates in contact with the surface of the cleaning roll 613a can act so as to further adhere and collect residual toner and sliding oil transferred to the surface of the cleaning roll 613a. Here, since the width of the cleaning web 613b is set to be equal to or longer than the width of the cleaning roll 613a, residual toner and sliding oil transferred to the surface of the cleaning roll 613a can be captured without omission.
That is, when the sliding oil used on the inner surface side of the fixing belt 610 is to be transferred to the outer surface side of the fixing belt 610, the cleaning roll 613a and the cleaning web 613b can remove the sliding oil to be transferred. . Therefore, the fixing device 60 of the present embodiment acts to reduce the risk of image defects caused by the sliding oil oozing out on the surface of the fixing belt 610. Further, the image forming apparatus including the fixing device 60 acts to reduce the risk of image defects caused by the sliding oil oozing out on the surface of the fixing belt 610.

  In the present embodiment, the cleaning module 613 (fixing device 60) including the cleaning roll 613a having a surface hardness set lower than the outer surface hardness of the fixing belt 610 may damage the outer surface of the fixing belt 610. Acts to reduce. That is, the cleaning module 613 (fixing device 60) acts to reduce the risk of image defects caused by the outer surface of the fixing belt 610 being damaged.

Further, in the present embodiment, the cleaning module 613 (fixing device 60) including the cleaning web 613b impregnated with the cleaning oil acts to clean the surface of the cleaning roll 613a satisfactorily.
In addition, the cleaning web 613b impregnated with the cleaning oil can supply a small amount of oil to the interface between the cleaning roll 613a and the fixing belt 610, and acts to reduce the friction between the cleaning roll 613a and the fixing belt 610. Can do. By reducing the friction, the risk of image defects caused by the outer surface of the fixing belt 610 being damaged is further reduced.

Further, the fixing device 60 includes a transfer prevention member that prevents the sliding oil attached to the inner surface side of the fixing belt 610 from transferring to the outer surface side of the fixing belt 610 at the end in the width direction of the fixing belt 610. be able to.
FIG. 4 is a schematic plan view for explaining the transfer preventing member installed on the inner surface side of the fixing belt 610. FIG. 4A shows an example in which a rubber pad 610a is disposed in contact with the inner surface side of the fixing belt 610 that proceeds in the direction of the arrow in the drawing. FIG. 4B shows an example in which the fiber pad 610b is disposed in contact with the inner surface side of the fixing belt 610 that proceeds in the direction of the arrow in the drawing. In the present embodiment, rubber pad 610a and fiber pad 610b have a substantially rectangular shape in plan view. Further, the rubber pad 610 a is disposed with a predetermined inclination with respect to the traveling direction of the fixing belt 610.

The rubber pad 610a disposed in contact with the inner surface side of the fixing belt 610 can act to attract the sliding oil to the center portion on the inner surface side of the fixing belt, although it has little effect of adsorbing the sliding oil itself. . That is, the rubber pad 610 a acts to prevent the sliding oil from transferring to the outer surface side of the fixing belt 610 through the end surface of the fixing belt 610. As a material for forming the rubber pad 610a, for example, a material containing silicone rubber or fluororesin (for example, fluororubber) can be used.
Further, the fiber pad 610b disposed in contact with the inner surface side of the fixing belt 610 itself has an action of adsorbing sliding oil. Like the rubber pad 610a, the sliding oil passes through the end surface of the fixing belt 610. It can act to suppress the transfer to the outer surface side of the fixing belt 610. Note that the surface of the fiber used for the fiber pad 610b is preferably coated with silicone rubber or fluororubber.
In addition, the shape, arrangement position, material, and the like of the transfer preventing member can be appropriately selected according to the use of the fixing device and the image forming apparatus, the operating conditions, and the like. Also. In the present embodiment, the rubber pad 610a and the fiber pad 610b are exemplified as the transition preventing member, but the material and shape are not limited to these. The transition prevention member is preferably a member having excellent slidability and heat resistance.

1 is a schematic configuration diagram illustrating an image forming apparatus to which the exemplary embodiment is applied. FIG. 2 is a side sectional view showing a schematic configuration of a fixing device according to the present embodiment. FIG. 3 is a schematic plan view when a cleaning roll is observed from an X direction in FIG. 2. FIG. 3 is a schematic plan view for explaining a transition prevention member installed on the inner surface side of the fixing belt.

Explanation of symbols

1Y, 1M, 1C, 1K ... image forming unit, 11 ... photosensitive drum, 12 ... charger, 13 ... laser exposure device, 14 ... developer, 15 ... intermediate transfer belt, 16 ... primary transfer roll, 17 ... drum cleaner , 20 ... secondary transfer section, 60 ... fixing device, 61 ... fixing belt module, 62 ... pressure roll, 64 ... pressure pad, 610 ... fixing belt, 611 ... fixing roll, 612, 614, 615 ... stretching roll, 613 ... Cleaning module, 613a ... Cleaning roll, 613b ... Cleaning web, 613c ... Pressure contact roll, 613d ... Feeding roll, 613e ... Winding roll, 616a, 616b, 616c ... Halogen heater, 620 ... Sliding oil supply member, N ... Press contact part, P ... paper

Claims (6)

A rotating fixing belt;
A fixing member provided inside the fixing belt;
The fixing belt is disposed so as to press against the fixing member through the toner image between the fixing member, on to the recording material by passing the recording material the toner image unfixed was formed a pressure member that form a pressure contact portion for fixing,
At the downstream side in the rotational direction of the fixing belt from the pressure contact portion is disposed in contact with the inner surface of the fixing belt, a pressing member for pressing the outer surface of the fixing belt to the pressure member,
A lubricant supply member for supplying a lubricant to the inner surface of the fixing belt;
The fixing belt is placed in contact with the outer surface of a first cleaning member for cleaning the outer surface of the fixing belt after the toner image is fixed onto the recording material,
A second cleaning member disposed in contact with the first cleaning member and cleaning the surface of the first cleaning member;
A direction along the surface of the recording material passing through the pressure contact portion and perpendicular to the passing direction of the recording material is a width direction of the fixing belt, and the length of the fixing belt along the width direction is the fixing belt. The length of the first cleaning member along the width direction is the width of the first cleaning member, and the length of the second cleaning member along the width direction is the width of the second cleaning member. If
The width of the second cleaning member is equal to or greater than the width of the first cleaning member, and the width of the first cleaning member is larger than the width of the fixing belt. The lubricant disposed on the inner surface of the fixing belt in contact with both ends in the width direction of the fixing belt and adhered to the inner surface of the fixing belt is transferred to the outer surface side of the fixing belt. The fixing device according to claim 1, further comprising a transfer preventing member for preventing the transfer.   The fixing device according to claim 1, wherein a surface hardness of the first cleaning member is lower than an outer surface hardness of the fixing belt.   The fixing device according to claim 1, wherein the second cleaning member is impregnated with cleaning oil.   The fixing device according to claim 1, wherein the first cleaning member is disposed downstream of the lubricant supply member in the fixing belt rotation direction and upstream of the pressing member in the rotation direction of the fixing belt. Toner image forming means for forming a toner image;
Transfer means for transferring the toner image formed by the toner image forming means onto a recording material;
Fixing means for fixing the toner image transferred onto the recording material to the recording material,
The fixing means is
A rotating fixing belt;
A fixing member provided inside the fixing belt;
Via said fixing belt is disposed so as to press against the fixing member, the toner on the between the fixing member, the recording material on by passing the recording material the toner image unfixed was formed a pressure member that form a pressure contact portion for fixing the image,
At the downstream side in the rotational direction of the fixing belt from the pressure contact portion is disposed in contact with the inner surface of the fixing belt, a pressing member for pressing the outer surface of the fixing belt to the pressure member,
A lubricant supply member for supplying a lubricant to the inner surface of the fixing belt;
The fixing belt is placed in contact with the outer surface of a first cleaning member for cleaning the outer surface of the fixing belt after the toner image is fixed onto the recording material,
A second cleaning member disposed in contact with the first cleaning member and cleaning the surface of the first cleaning member;
A direction along the surface of the recording material passing through the pressure contact portion and perpendicular to the passing direction of the recording material is defined as the width direction of the fixing belt, and the length of the fixing belt along the width direction is the fixing belt. The length of the first cleaning member along the width direction is the width of the first cleaning member, and the length of the second cleaning member along the width direction is the width of the second cleaning member. If
The width of the second cleaning member is equal to or greater than the width of the first cleaning member, and the width of the first cleaning member is larger than the width of the fixing belt.

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