JP2013061516A - Fixing device, and image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress variation of increasing speed of a web winding diameter of a cleaning web of a take-up roller through total life of the cleaning web regardless of variation in an amount of toner.SOLUTION: A cleaning roller 51, the take-up roller 52, and a supply roller which are arranged to the cleaning web unit 40 which cleans the pressure roller 22 of a fixing device 20 with the cleaning web 54 are made to follow the movement of the pressure roller 22. The cleaning web unit 40 is provided with a pressing member 31 which comes into contact with an outermost circumferential part of the cleaning web to be taken up the take-up roller 52, exerts pressing force toward a shaft of the take-up roller, and increases the pressing force as the take-up radius of the cleaning web increases.

Description

  The present invention relates to a fixing device value and an image forming apparatus, and more particularly to a fixing device using a fixing belt and an image forming apparatus including the fixing device.

  As a fixing device, a nip portion is formed between a fixing member having an internal heat source and a pressure member pressed against the fixing member, and a transfer paper holding an unfixed toner image is passed through the nip portion to determine the fixing device. Some fix toner on a recording medium. The surface of the fixing member has been devised to prevent toner adhesion, such as fluorine coating, but the toner peeled off the recording medium may adhere to the fixing member depending on conditions such as the environment and the characteristics of the recording medium. There is. This phenomenon is called offset.

  When the offset occurs, the toner remains on the fixing member and the pressure member in contact with the fixing member, and eventually the toner is reversely transferred to the recording medium to stain the image. In order to prevent this, the fixing member is provided with a cleaning member such as a cleaning web or a cleaning roller. The cleaning member is pressed against the fixing member and the pressure member, and the toner adhering to the pressure member is collected. As the cleaning member, a belt-like cleaning web may be used. The cleaning web is pulled out from the wound state, wiped off the pressure member, and then wound up and collected.

  Some fixing devices have a pressure member position adjusting means for moving the pressure member with respect to the fixing member to contact, depressurize, or separate. The position adjusting means is used when the pressure member is separated from the fixing member when the fixing device is not used, or when only the pressure member is cooled. Thus, the position adjusting means prevents deterioration of the fixing member and the pressure member without applying a load to the constituent members.

  In addition, when the pressure member is pressed against the fixing member, the position adjusting unit may be set to a plurality of positions for pressing the pressure member and the fixing member with different forces, such as “strong” and “weak”. . This position adjustment function is used for the purpose of creating an optimum contact state depending on the environment and the conditions of the recording medium.

  When the cleaning member is pressed against the pressure member whose position is adjusted in this way by the cleaning roller, if the cleaning roller and the pressure member are separated from each other, the cleaning member is not sufficiently pressed against the pressure member. As a result, the pressure member is not sufficiently cleaned by the cleaning member. In addition, when the distance between the cleaning roller and the pressure member becomes short, the large pressing force promotes the deterioration of the material of the cleaning member and the pressure member, and the torque necessary for winding the cleaning web, which is the cleaning member, increases and becomes normal. The cleaning web cannot be collected.

  Further, if the change in the position of the pressure member is small at the contact position of the cleaning member, there is no problem even if the cleaning member is fixed to the fixing device. However, if the pressure member is largely separated, the positional change with the cleaning member becomes large, which may cause problems such as retransfer of the ejected toner to the recording medium.

  Further, when the cleaning web is used as the cleaning member and the pressure member moves, the following problem occurs. That is, since the axial positional relationship between the winding roller for collecting the used cleaning web and the supply roller for supplying a new cleaning web changes, sagging of the cleaning web occurs, and normal used cleaning web cannot be collected. It is. In order to prevent the occurrence of this problem, the cleaning web is moved following the movement of the pressure member.

  However, even if such a problem is prevented, if the recording medium is jammed after passing through the nip portion, a problem occurs when the user takes out the recording medium with his / her hand. Depending on how the recording medium is taken out when the jam is eliminated, the pressure member is driven in the direction opposite to the original driving direction. That is, the pressure member is driven in the reverse direction if it is a roller, and in the reverse direction if it is a belt. When the pressure member is driven in the reverse direction as described above, the cleaning web is excessively unwound from the supply roller at the cleaning nip portion where the cleaning web is in contact with the pressure roller, thereby increasing the web slack.

  If the slack of the web becomes large and normal winding operation cannot be performed, a cleaning failure occurs, and an abnormal image due to so-called black spots or slip-through is caused, and the slack web reaches the fixing nip and cannot pass the paper.

  As a countermeasure against this, there is known a control in which after the occurrence of a jam, an operation of winding a certain amount of the cleaning web is performed, and then the next sheet passing operation is performed. In this control, there is a problem that the processing is delayed and the cleaning web is unnecessarily consumed by the operation of winding the cleaning web by a certain amount.

  As another countermeasure, Patent Document 1 describes a mechanism that does not cause the sagging of the cleaning web itself. That is, the invention described in Patent Document 1 has a mechanism for controlling the strength of the pressing force of the cleaning roller, or contact and separation, and realizes an optimum cleaning function according to the use situation.

  Furthermore, there are a wide variety of output images in the image forming apparatus, and the type of recording medium and the amount of paper passing are not constant. Therefore, the amount of offset toner entering the cleaning nip is not constant, and the amount of collected toner in the cleaning nip varies greatly. In this case, the tension of the cleaning web from the take-up roller to the cleaning nip varies greatly depending on the amount of offset toner, and as a result, the speed of increase of the take-up roller diameter is also affected.

  For example, after the cleaning web is continuously wound up in a state where there is almost no offset toner amount, if a toner with poor fixing due to a jam enters the cleaning unit as an offset toner, the cleaning web is discharged from the winding roller. This is because the cleaning web that has been loosely wound up to that point cannot withstand the web tension increased by the large amount of offset toner in the cleaning nip portion. In addition, the loosening of the cleaning web is accumulated as the cleaning web is wound up in large quantities. Therefore, the larger the winding roller diameter, the larger the amount of loosening, which is necessary to eliminate the loosening. External force also increases.

  Furthermore, when some load is applied to the drive system for web winding or the web itself in order to eliminate loose winding of the web, the winding torque may be increased or the web may be broken.

  Japanese Patent Application Laid-Open No. H10-228561 discloses a technique in which web dirt is read by an optical sensor and the winding amount is controlled.

  Further, Patent Document 3 discloses a technique in which a tension roller is provided upstream of the winding roller and tension is applied to the web by rotating the tension roller in the direction opposite to the web feeding direction, thereby reducing the winding roller diameter.

  However, although the thing of patent document 2 can control winding amount, there exists a problem that the dispersion | variation in the speed which the winding diameter of a winding roller increases cannot be suppressed.

  Moreover, the thing of patent document 3 has the problem that cost increases because the tension roller which is a longitudinal component, and the mechanism which rotationally drives this are needed.

  The present invention has been made in view of the above points, and fixing that can suppress variation in speed at which the winding diameter of the cleaning web of the winding roller increases can be suppressed throughout the life of the cleaning web regardless of variation in toner amount. An object is to provide an apparatus.

  The fixing device according to the present invention includes an endless fixing belt that is wound around a plurality of holding members and is driven to travel, and a recording medium that is pressed against an outer peripheral surface of the fixing belt and passes through the recording medium. A pressure member that forms a nip portion for fixing the toner layer adhering to the recording medium, and an arrangement position of the pressure member with respect to the fixing belt to change the presence / absence of the nip portion and the nip portion A pressure adjusting mechanism that adjusts the conveyance direction dimension of the recording medium, at least a supply roller that supplies a cleaning web for wiping off adhering matter on the pressure member, and pressing the cleaning web against the pressing member to wipe off adhering matter. A cleaning web unit having a cleaning roller, and a winding roller that winds and collects the cleaning web after wiping off the adhering matter of the pressure member. And a position adjusting mechanism that makes the contact position, the contact direction, and the pressing force of the cleaning roller follow the movement of the pressure adjusting mechanism of the pressure member constant. The cleaning web wound on the take-up roller is brought into contact with the outermost peripheral portion of the cleaning web wound on the rotating shaft of the take-up roller, and a pressing force is applied in the axial direction of the take-up roller. A pressing member that increases the pressing force as the winding diameter increases is provided.

  According to the present invention, even when the tension applied to the cleaning web varies, it is possible to suppress variation in the speed at which the winding diameter of the winding roller increases, and it is possible to perform stable toner cleaning and thus good image formation. realizable.

1 is a cross-sectional view illustrating a schematic configuration of an image forming apparatus according to a first embodiment. 2 is a schematic diagram illustrating a configuration of a fixing device of the image forming apparatus. FIG. 2 shows a fixing unit of the fixing device, wherein (a) is a schematic diagram illustrating a fixing process, and (b) is a schematic diagram illustrating a moving state of a pressure roller. FIG. 2 is a schematic diagram illustrating a cleaning web unit of the fixing device. FIG. 6 is a schematic diagram illustrating a behavior of a cleaning web unit of the fixing device. It is a schematic diagram which shows the behavior of the pressing member of the fixing device. It is a schematic diagram which shows the behavior of the pressing member of the fixing device. FIG. 2 is a schematic diagram illustrating a fixing unit to which Embodiment 1 is applied. FIG. 4 is a schematic diagram illustrating a fixing device according to a second embodiment. FIG. 10 is a schematic diagram illustrating a fixing device value according to a third embodiment. FIG. 4 is a schematic diagram illustrating a removed state of a cleaning unit in the fixing device. FIG. 6 is a schematic diagram illustrating a fixing device value according to a fourth embodiment. It is a schematic diagram showing the behavior of the fixing device

  Hereinafter, a fixing device according to an embodiment for carrying out the present invention (hereinafter simply referred to as an embodiment) and an image forming apparatus including the fixing device will be described.

<Embodiment 1>
A fixing device and an image forming apparatus according to Embodiment 1 will be described with reference to the drawings. First, the basic configuration of the image forming apparatus will be described. FIG. 1 is a schematic configuration diagram of an image forming apparatus according to the first embodiment. The image forming apparatus 100 includes four process units 101Y, 101C, 101M, and 101Bk configured to be detachable from the image forming apparatus main body 130 as image forming means. The process units 101Y, 101C, 101M, and 101Bk have the same configuration except that toners of different colors of yellow, cyan, magenta, and black corresponding to the color separation components of the color image are accommodated. Therefore, the configuration of one process unit 101Y will be described as an example.

  The process unit 101Y includes a photosensitive member 102, a charging device 103 that charges the surface of the photosensitive member 102, a developing device 104 that forms a toner image on the surface of the photosensitive member 102, and a cleaning device 105 that cleans the surface of the photosensitive member 102. And comprising.

  Above the process unit 101Y, an exposure device 107 is provided as exposure means for exposing the surface of the photoreceptor 102. On the other hand, an intermediate transfer unit 106 is disposed below each process unit 101Y. The intermediate transfer unit 106 includes an endless intermediate transfer belt 110. The intermediate transfer belt 110 is stretched over a plurality of rollers 117, 118, and 119, and is configured to be able to run around in the direction of the arrow in the figure. A belt cleaning device 116 is disposed at the left end of the intermediate transfer belt 110 in the drawing.

  Four primary transfer rollers 111 as primary transfer means are provided on the inner peripheral surface of the intermediate transfer belt 110. The photoconductors 102 of the process units 101Y, 101C, 101M, and 101Bk are in contact with the outer peripheral surface of the intermediate transfer belt 110 at positions facing the four primary transfer rollers 111 to form a primary transfer nip. In addition, a secondary transfer roller 112 as a secondary transfer unit is disposed at a position facing one roller 117 around which the intermediate transfer belt 110 is hung. The secondary transfer roller 112 contacts the outer peripheral surface of the intermediate transfer belt 110 to form a secondary transfer nip.

  A plurality of paper feed cassettes 113 that contain recording media S such as recording paper are disposed below the image forming apparatus main body 130. Each paper feed cassette 113 is provided with a paper feed roller 114 and the like for carrying out the recording medium S. In the image forming apparatus main body 130, a paper conveyance path R for guiding the recording medium S is arranged. In the paper transport path R, a pair of registration rollers 115 is disposed upstream of the secondary transfer roller 112 in the recording medium transport direction P.

  Further, the fixing device 20 according to the first exemplary embodiment for fixing an image on the recording medium S is disposed downstream of the secondary transfer roller 112 in the recording medium conveyance direction P. A stock unit 109 for stocking the recording medium S discharged to the outside is disposed on the left side of the image forming apparatus main body 130 in the drawing. Further, on the upper side of the image forming apparatus main body 130, a document reading device 120 that reads a document and acquires image data is arranged.

  Hereinafter, a basic operation of the image forming apparatus main body 130 will be described. When the image forming operation is started, a driving device (not shown) rotates and drives the photosensitive members 102 of the process units 101Y, 101C, 101M, and 101Bk counterclockwise in the drawing. The charging device 103 uniformly charges the surface of each photoconductor 102 to a predetermined polarity, the exposure device 107 irradiates the surface of each photoconductor 102 charged with laser light, and the surface of each photoconductor 102 is irradiated. An electrostatic latent image is formed.

  At this time, the image information to be exposed on each photoconductor 102 is single-color image information obtained by separating a desired full-color image into color information of yellow, cyan, magenta, and black. Each developing device 104 supplies toner to the electrostatic latent image formed on the photosensitive member 102 in this manner, whereby the electrostatic latent image is visualized as a toner image.

  In addition, a constant voltage having a polarity opposite to the toner charging polarity and a constant current controlled voltage are applied to each primary transfer roller 111. Thereby, a transfer electric field is formed at the primary transfer nip between each primary transfer roller 111 and each photoconductor 102. Then, the toner images of the respective colors formed on the respective photoreceptors 102 of the respective process units 101Y, 101C, 101M, and 101Bk are sequentially superimposed and transferred onto the intermediate transfer belt 110 by the transfer electric field formed in the primary transfer nip. To do. In this way, a full-color toner image is transferred onto the intermediate transfer belt 110.

  Residual toner adhering to the surface of each photoconductor 102 after the toner image is transferred is removed by each cleaning device 105, and then the surface is decharged by a decharging device (not shown), The potential is initialized to prepare for the next image formation.

  A sheet feeding roller 114 feeds the recording medium S from one of the plurality of sheet feeding cassettes 113 to the sheet conveyance path R. The recording medium S sent to the sheet conveyance path R is sent to the secondary transfer nip between the secondary transfer roller 112 and the roller 117 by timing with the registration roller 115. At this time, a transfer voltage having a polarity opposite to the toner charging polarity of the toner image on the intermediate transfer belt 110 is applied to the secondary transfer roller 112, and a transfer electric field is formed in the secondary transfer nip.

  Then, the toner images on the intermediate transfer belt 110 are collectively transferred onto the recording medium S by a transfer electric field formed in the secondary transfer nip. Further, the toner remaining on the surface of the intermediate transfer belt 110 after image transfer is removed by the belt cleaning device 116. The recording medium S to which the toner image has been transferred is conveyed to the fixing device 20, and the toner image is fixed by applying heat and pressure to the recording medium S. Thereafter, the recording medium S is discharged from the fixing device 20 to the stock unit 109. Thus, the full color image forming process on the recording medium S is completed.

  Although the above description is an image forming operation when a full-color image is formed on the recording medium S, a single-color image is formed using any one of the four process units 101Y, 101C, 101M, and 101Bk. can do. Further, two or three process units can be used to form a two-color or three-color image.

  Next, the fixing device 20 according to the embodiment will be described. FIG. 2 is a schematic diagram illustrating a fixing device of the image forming apparatus according to the first embodiment. The fixing device 20 includes a fixing unit 30 that fixes the recording medium S and a cleaning web unit 40 that removes residual toner from the fixing unit 30.

  First, the fixing unit 30 will be described. FIGS. 3A and 3B show a fixing unit of the identification fixing device. FIG. 3A is a schematic diagram showing a fixing process, and FIG. 3B is a schematic diagram showing a moving state of a pressure roller. The fixing unit 30 includes an endless, ie, an annular fixing belt 23, a fixing roller 21 as a holding member, and a heating roller 24. The fixing belt 23 is disposed around the fixing roller 21 and the fixing belt 23. Note that the fixing belt 23 can be arranged around three or more rollers.

  A pressure roller 22 as a pressure member is in contact with the outer surface of the fixing belt 23 at a contact portion with the fixing roller 21, and the pressure roller 22 is pressed against the outer periphery of the fixing belt 23 wound around the fixing roller 21. It has been. The pressure roller 22 is driven to rotate in the direction of arrow A in FIG. 2 by a driving source such as a motor (not shown), and the rotation is transmitted to the fixing roller 21 via a gear (not shown). Then, the fixing roller 21 is rotationally driven in the direction of arrow B by the rotation of this gear.

  Further, the fixing roller 21 is driven to run in the direction of arrow C by the rotation of the fixing roller 21, whereby the heating roller 24 is driven to rotate in the direction of arrow D in FIG. A pressure belt can be used as the pressure member. Furthermore, the heating roller 24 is formed hollow, and a heater 25 is disposed therein, and the heating roller 24 and the fixing belt 23 are heated by the heater 25, respectively. The pressure roller 22 and the fixing roller 21 can be hollow shafts, and heaters can be arranged inside to heat each roller.

  Further, a temperature sensor (not shown) is disposed opposite to the portion where the fixing belt 23 contacts the heating roller 24, the portion where the fixing belt contacts the fixing roller 21, and the pressure roller 22. Energization of each heater is controlled based on the temperature detection result by each sensor. Then, the temperature of the fixing belt 23 and the pressure roller 22 is controlled to be a temperature suitable for fixing the toner layer.

  As shown in FIG. 3A, a nip formed between the pressure roller 22 and the recording belt S on which the unfixed toner image Ta is transferred is formed between the fixing belt 23 disposed around the fixing roller 21. And fixing by heating and heating. The fixed toner image Ta is shown in FIG.

  In the fixing device 20 according to the first exemplary embodiment, as illustrated in FIG. 3B, the pressure roller 22 has a pressure adjusting mechanism that moves so as to be separated from and close to the fixing roller 21 around a predetermined shaft member 26. Is connected. The pressure adjusting mechanism includes a driving unit (not shown), and the pressure roller 22 is disposed between the pressure reduction state 22-1 (broken line) and the pressure state 22-2 (solid line).

  Next, the cleaning web unit 40 will be described. FIG. 4 is a schematic diagram showing a basic configuration of the cleaning web unit. The cleaning web unit 40 removes residual toner from the pressure roller 22 by pressing an unused portion in the middle of the pulling out against the pressure roller 22 when the long cleaning web being wound is pulled out and wound. The cleaning web unit 40 moves following the movement of the pressure roller 22.

  The cleaning web unit 40 includes a cleaning roller 51 that presses the cleaning web 54 against the pressure roller 22, a winding roller 52 that winds and collects the cleaning web 54, and a supply roller 53 that holds the cleaning web 54 and supplies it. . The cleaning web 54 from which residual toner has been wiped off by the cleaning roller 51 is taken up by the take-up roller 52 being rotated in the direction of arrow E in FIG. Collect in the G direction.

  Along with this, the supply roller 53 is pulled by the web and is rotated in the direction of arrow F to unwind a new cleaning web 54 in the direction of arrow H. Then, the pulled out unused cleaning web 54 is conveyed to a contact portion between the cleaning roller 51 and the pressure roller 22 to clean the pressure roller 22.

  In the fixing device 20 having such a configuration, the cleaning web unit 40 always keeps the cleaning roller 51 following the movement of the pressure roller 22 and the contact position, contact direction, and pressing force of the cleaning roller with respect to the pressure member. It is equipped with a constant adjustment mechanism. Further, the pressing member 31 applies a pressing force directed toward the axis of the winding roller at the outermost peripheral portion of the cleaning web unit 40 that is wound around the winding roller 52. Further, the pressing member 31 increases the pressing force as the winding diameter of the cleaning web 54 of the winding roller 52 increases.

  The adjustment mechanism has the following configuration. As shown in FIG. 2, the cleaning web unit 40 includes a rotating member 91 that rotates together with the pressure roller 22 around the shaft member 26. The rotating member 91 includes a hole portion that holds the journal portion of the pressure roller 22, and fixes the distance between the pressure roller 22 and the shaft member 26 to be constant. Further, the cleaning web unit 40 includes a base member 81 attached to the rotating member 91. The base member 81 includes positioning pins 82 and 83 and a square hole portion 55. The base member 81 is attached to the rotating member 91 with positioning pins 82 and 83, and is fixed to the rotating member 91 in the xy plane.

  The base member 81 holds the cleaning roller 51, the winding roller 52, and the supply roller 53. The cleaning roller 51 is disposed in a slide bearing 57 disposed in the square hole portion 55. Thereby, the moving direction of the cleaning roller 51 is limited to the direction along the arrow I in the figure. The cleaning roller 51 is always pressed against the pressure roller 22 by a compression spring 56 with a constant force.

  A case where the pressure roller 22 moves in the fixing device will be described. FIG. 5 is a schematic diagram showing the behavior of the cleaning web unit. For example, when the pressure state shown in FIG. 6A shifts to the pressure reduction state shown in FIG. 6B, the rotation member 91 is centered on the shaft member 26 as the cleaning roller 51 and the pressure roller 22 move. Rotate and move. For this reason, the positional relationship of the cleaning roller 51, the winding roller 52, and the winding roller 52 attached to the base member 81 fixed to the rotating member 91 and the direction of the pressing force of the cleaning roller 51 do not change.

  Next, the pressing member 31 will be described. The pressing member 31 presses the outermost peripheral portion of the cleaning web 54 wound on the rotating shaft of the winding roller 52 toward the center of the winding roller 52. The pressing force of the pressing member 31 increases as the web wound on the winding roller 52 increases. The pressing member 31 is configured by a plate member fixed to the base member 81 and having elasticity, for example, a plate spring made of stainless steel (SUS).

  The pressing member 31 presses the surface of the cleaning web 54 wound around the winding roller 52 toward the center of the winding roller 52. It is desirable to form a fluorine coating layer with a low coefficient of friction force on the surface layer of the pressing member 31 that contacts the cleaning web 54. By providing the fluorine coating layer, it is possible to minimize the frictional sliding load on the cleaning web 54, and to prevent an increase in winding torque and web breakage.

  6 and 7 are schematic views showing the behavior of the pressing member of the identification attaching device. FIG. 6 shows a state at the beginning of winding of the cleaning web 54, and FIG. 7 shows a state in which the winding amount of the cleaning web 54 is increased. In both figures, (a) is when the pressure roller 22 is in a pressurized state (22-2 in the figure), and (b) is when the pressure roller 22 is in a reduced pressure state (22-1 in the figure). Is shown.

  When the diameter of the cleaning web 54 taken up by the take-up roller 52 is initially small and the diameter is small (FIGS. 7A and 7B), the diameter becomes large (FIGS. 8A and 8B). )), The amount of deflection of the pressing member 31 increases. For this reason, the force which presses the cleaning web 54 wound around the winding roller 52 by the pressing member 31 increases.

  When the pressure roller 22 moves from the pressurized state (FIGS. 7A and 8A) to the reduced pressure state (FIGS. 7B and 8B), the pressing member 31 is Since it moves together with the member 81, the pressing force of the pressing member 31 does not change. The pressing member 31 may be made of other materials such as synthetic resin instead of stainless steel.

  As the fixing unit 30, the following unit having another configuration can be used instead of the unit shown in FIG. 2. FIG. 8 is a schematic diagram illustrating a fixing unit to which the first exemplary embodiment is applied. The example shown in FIG. 8A includes a separation roller 41, a tension roller 42, a fixing roller 21a, a heating roller 24, and a fixing belt 23a wound around these. In addition, the example shown in FIG. 8B includes two pressure rollers 22a and 22b as a pressure unit, and a fixing belt 23a wound around them.

  Further, the example shown in FIG. 8C includes a fixing belt 23, a fixing roller 21 a around which the fixing belt 23 is wound, and a heating roller 24. In these examples, the case where the nip portion is formed by using the fixing roller 21 is shown. However, a nip portion is formed between the pressure roller 22 and a contact member that contacts a part or all of them without rotating. It can be set as the structure to do.

  According to the fixing device 20 according to the first exemplary embodiment, even when the offset toner amount varies and the cleaning web tension varies, the diameter of the winding roller 52 can always be minimized. For this reason, variation in the increasing speed of the winding diameter of the cleaning web can be suppressed. Moreover, since the pressing member 31 bends largely as the cleaning web 54 at the winding roller 52 increases, a larger pressing force can be obtained, and variations in the increasing speed of the winding roller diameter can be suppressed.

<Embodiment 2>
Next, the fixing device 90 of the image forming apparatus according to the second embodiment will be described. FIG. 9 is a schematic diagram illustrating a fixing device according to the second embodiment. A fixing device 90 according to the second embodiment includes a fixing unit 30 and a cleaning web unit 80. In the fixing device 90 according to the second embodiment, a bearing 58 incorporating a one-way clutch is disposed in the base member 81 of the cleaning web unit 80, and the winding roller 52 is disposed via the bearing 58. The one-way clutch of the bearing 58 allows rotation only in the rotation direction in which the cleaning web 54 is wound around the winding roller 52, and prohibits rotation against reverse rotation.

  The bearing 58 and the base member 81 are fixed by attaching the bearing 58 to an attachment portion 84 formed on the base member 81. In addition to the illustrated one, the fixing unit 30 having the structure shown in FIG. 8 can be used as the fixing unit 30.

  According to the fixing device 90 according to the second embodiment, the cleaning web 54 taken up on the take-up roller 52 is pulled by the adhesive force of the toner, a web tension is generated, and the take-up roller 52 rotates in the reverse direction. To prevent. Thereby, it is possible to prevent the used cleaning web from being discharged again to the cleaning unit. It should be noted that the fixing unit can be replaced with the example shown in FIG.

<Embodiment 3>
Next, the fixing device 140 according to the third embodiment will be described. FIG. 10 is a schematic diagram showing a fixing device value according to the third embodiment, and FIG. 11 is a schematic diagram showing a removed state of the cleaning means in the identification apparatus.

  The fixing device 140 according to the third embodiment includes a fixing unit 30 and a cleaning web unit 150, and a drive source 71 that drives the cleaning web unit 150 is disposed outside the fixing device 140 and is detachable from the cleaning web unit 150. Connect to Then, the cleaning web unit 150 other than the drive source 71 can be removed while the cleaning web unit 150 is removed from the drive source 71.

  The fixing unit 30 is the same as the fixing unit 30 according to the first embodiment, and includes a fixing roller 21, a pressure roller 22, a heating roller 24, a fixing belt 23, and a heater 25. Each example shown in FIG. 8 can be used as the fixing unit.

  The cleaning web unit 150 includes a cleaning roller 51, a take-up roller 52, a supply roller 53, a cleaning web 54, a base member 81, a rotating member 91, and a pressing member 31, and a driving source 71 that can be attached and detached with a joint unit 160. . The basic configuration of the fixing device 140 is the same as that of the fixing devices 20 and 90 of the first and second embodiments described above, except that the drive source 71 is disposed outside. For this reason, the cleaning roller 51, the winding roller 52, and the supply roller 53 of the fixing device 140 move following the pressure roller 22 by the base member 81 and the rotating member 91 that rotate about the shaft member 26.

  In the cleaning web unit 150 according to the third embodiment, the winding roller 52 includes a spur gear 61 coaxially. Then, the worm gear 62 meshing with the spur gear 61 is rotationally driven by the drive source 71. The drive shaft 72 of the drive source 71 is detachably connected to the rotating shaft 63 of the worm gear 62 by a joint portion 160. The joint portion 160 includes a pin 64 attached to the rotary shaft 63 and a drive transmission member 73 attached to the drive shaft 72 and having a recess into which the pin 64 fits.

  When the pin 64 is coupled to the recess of the drive transmission member 73, the rotational force of the drive source 71 in the direction of arrow K in FIG. 10 is transmitted to the rotation shaft 63, and the rotation shaft 63 is driven in the direction of arrow J. Here, even if the cleaning web unit 150 rotates about the shaft member 26, the joint portion 160 transmits the rotation of the drive source 71 to the rotating shaft 63 of the worm gear 62 without being disconnected.

  In the fixing device 140 according to the third embodiment, the drive transmission member 73 and the pin 64 of the joint portion 160 can be removed by moving the cleaning web unit 150 upward. For this reason, the fixing device 140 can be separated in the direction indicated by the arrow L as shown in FIG. Then, the cleaning web unit 150 other than the drive source 71 can be detached from the fixing device 140 as shown in FIG. 11B (arrow N in FIG. 11B).

  According to the fixing device 140 according to the third embodiment, the cleaning web 54 can be wound around the winding roller 52 stably as in the first and second embodiments described above. In the fixing device 140, the drive source 71 is disposed outside the cleaning web unit 150. Therefore, when the cleaning web unit and the entire fixing device are replaced, the drive source 71 may be left as it is in the image forming apparatus. Thereby, parts can be replaced at low cost, and running cost can be reduced.

<Embodiment 4>
Next, the fixing device 170 according to the fourth embodiment will be described. FIG. 12 is a schematic diagram illustrating the fixing device value according to the fourth embodiment, and FIG. 13 is a schematic diagram illustrating the operation of the identification wearing device.

  A fixing device 170 according to the fourth embodiment includes a fixing unit 30 and a cleaning web unit 180. The fixing unit 30 is the same as that of the fixing device 20 according to the first embodiment described above. The cleaning web unit 180 is basically the same as the cleaning web unit 150 of the third embodiment.

  In the cleaning web unit 180 according to the fourth embodiment, the drive source 71 transmits the rotation to the take-up roller 52 by the joint portion 160 and is positioned and attached to the base member 81 of the cleaning web unit 180 by the coupling mechanism 190. The drive source 71 rotates integrally with a base member 81 that rotates in synchronization with the pressure roller 22.

  The fixing unit 30 includes a fixing roller 21, a pressure roller 22, a heating roller 24, a fixing belt 23, and a heater 25, and fixes the recording medium S.

  The cleaning web unit 180 includes a cleaning roller 51, a take-up roller 52, a supply roller 53, and a cleaning web 54. In the cleaning web unit 180, the winding roller 52 includes a spur gear 61 coaxially, and a worm gear 62 that meshes with the spur gear 61 is rotationally driven by a drive source 71. The drive shaft 72 of the drive source 71 is detachably connected to the rotating shaft 63 of the worm gear 62 and the joint portion 160. The joint portion 160 includes a pin 64 attached to the rotary shaft 63 and a drive transmission member 73 attached to the drive shaft 72 and having a recess into which the pin 64 fits. When the pin 64 is coupled to the concave portion of the drive transmission member 73, the rotational force of the drive source 71 is transmitted to the rotation shaft 63 to drive the rotation shaft 63 to rotate.

  As shown in FIG. 12, the coupling mechanism 190 includes a positioning pin 74 disposed upward from the driving source 71 and a hole 81 a that is opened in the base member 81 and into which the driving source 71 is fitted. By fitting the positioning pin 74 of the drive source 71 into the hole 81 a of the base member 81, the base member 81 and the drive source 71 are coupled, and the drive source 71 rotates as the base member 81 rotates. The drive source 71 can be removed from the base member 81 by releasing the attachment of the pin 64 and the drive transmission member 73 of the joint portion 160 and the positioning pin 74 and the hole portion 81a of the coupling mechanism 190. As a result, the drive source 71 can be removed from the cleaning web unit 180.

  As shown in FIGS. 12 and 13, with the positioning pin 74 inserted into the hole 81a, the drive source 71 and the base member 81 are fixed with respect to the xz plane. As a result, the drive source 71 rotates around the shaft member 26 together with the cleaning web unit 180.

  According to the fixing device 170 according to the fourth embodiment, the drive source 71 moves following the movement of the pressure roller 22 and is fixed to the cleaning web unit 180. Therefore, when the pressure roller 22 is in a pressurized state (22-2 in FIG. 12) and in a reduced pressure state (22-1 in FIG. 13), and further when the pressure roller 22 is separated from the fixing roller 21, the drive source 71 Moves together with the cleaning web unit 180. For this reason, the positional relationship between the drive source 71 and the cleaning web unit 180 is always constant.

  In addition, with the drive source 71 attached to the cleaning web unit 180, the positional relationship between the drive shaft 72 of the drive source 71 and the rotation shaft 63 of the cleaning web unit 180 can be fixed on the same line and at a constant distance.

  The fixing device 170 according to the fourth embodiment has the same effect as the fixing device 140 according to the third embodiment described above, and can securely fix the drive source to the cleaning web unit.

20: fixing device 21: fixing roller 22: pressure roller 23: fixing belt 23a: fixing belt 24: heating roller 25: heater 26: shaft member 30: fixing unit 31: pressing member 40: cleaning web unit 41: separation roller 42 : Tension roller 51: cleaning roller 52: take-up roller 53: supply roller 54: cleaning web 100: image forming apparatuses 101Y, 101C, 101M, 101Bk: process unit 102: photoconductor 103: charging device 104: developing device 105: cleaning Device 106: Intermediate transfer unit 107: Exposure device 109: Stock unit 110: Intermediate transfer belt 111: Primary transfer roller 112: Secondary transfer roller 113: Paper feed cassette 115: Registration roller 116: Belt cleaning device 117 118,119: Roller 120: the document reading apparatus 130: image forming apparatus main body

JP 2003-167465 A Japanese Patent Application Laid-Open No. 07-261591 Japanese Patent Laid-Open No. 10-097153

Claims (7)

An endless fixing belt that is driven and driven around a plurality of holding members;
A pressure member that forms a nip portion that is pressed against the outer peripheral surface of the fixing belt and passes a recording medium that is carried in, and fixes a toner layer attached on the recording medium to the recording medium;
A pressure adjusting mechanism that changes the position of the pressure member relative to the fixing belt to adjust the presence / absence of the nip portion and the conveyance direction dimension of the recording medium at the nip portion;
At least a supply roller for supplying a cleaning web for wiping off the deposit on the pressure member, a cleaning roller for pressing the cleaning web against the pressure member to wipe off the deposit, and cleaning after wiping off the deposit on the pressure member A cleaning web unit having a winding roller for winding and collecting the web;
In a fixing device including a position adjustment mechanism that makes a contact position, a contact direction, and a pressing force of the cleaning roller that follows the movement of the pressure adjustment mechanism of the pressure member constant with respect to the pressure member,
Cleaning that is in contact with the outermost peripheral portion of the cleaning web wound on the rotating shaft of the winding roller, applies a pressing force toward the axial direction of the winding roller, and is wound on the winding roller A pressing member that increases the pressing force as the web winding diameter increases;
A fixing device.   The fixing device according to claim 1, wherein a fluorine coating layer is formed on a surface of the pressing member.   The winding roller, the supply roller, the pressing member, the position adjusting mechanism, and the pressing member move according to the movement of the pressure member while maintaining their positional relationship. The fixing device according to claim 2.   The fixing device according to any one of claims 1 to 3, wherein the winding roller includes a one-way clutch mechanism that can rotate only in a direction in which the cleaning web is wound. A drive source for driving the winding roller is disposed outside the cleaning web unit,
5. The fixing device according to claim 1, wherein the cleaning web unit is removable from the fixing device.   5. The fixing device according to claim 1, wherein the driving source changes positions of the cleaning web unit and the pressure member according to positions of the cleaning web unit and the pressure member.   An image forming apparatus comprising: an image forming unit that forms a toner image on a sheet; and the fixing device according to claim 1.