CN111965965B

CN111965965B - Belt device and image forming apparatus

Info

Publication number: CN111965965B
Application number: CN202010386053.7A
Authority: CN
Inventors: 市桥治
Original assignee: Ricoh Co Ltd
Current assignee: Ricoh Co Ltd
Priority date: 2019-05-20
Filing date: 2020-05-09
Publication date: 2023-03-14
Anticipated expiration: 2040-05-09
Also published as: JP2020190597A; JP7288600B2; CN111965965A

Abstract

The invention relates to a belt device and an image forming apparatus, which are difficult to generate deformation in a cleaning component when a roller component is inclined. A shaft tilting member (81) for tilting a roller shaft (17 b) in conjunction with the movement of an intermediate transfer belt (8) (belt member) in the width direction, a cleaning member (85) for cleaning the intermediate transfer belt (8), and a movable plate (83) (support member) which supports the roller shaft (17 b) and is rotatable about a support shaft (83 a) are provided. One end side in the width direction of the cleaning member (85) is supported so as to be rotatable relative to the roller shaft (17 b), and the other end side in the width direction is supported on the roller shaft (17 b) in a non-rotating manner.

Description

Belt device and image forming apparatus

Technical Field

The present invention relates to a belt device provided with a belt member that travels in a predetermined direction, and an image forming apparatus such as a copier, a printer, a facsimile machine, or a multifunction peripheral thereof, which is provided with the belt device.

Background

Conventionally, there is known an apparatus in which a correction mechanism (belt deviation correction device) for correcting a belt deviation of a belt member such as an intermediate transfer belt is provided in an image forming apparatus such as a copying machine or a printer (for example, see patent documents 1 and 2).

In detail, in the image forming apparatus of patent document 1, toner images formed on a plurality of photosensitive drums (photosensitive bodies) are primary-transferred while being superposed on the surface of an intermediate transfer belt. Then, the toner image carried by the intermediate transfer belt is secondarily transferred onto the sheet conveyed to the position of the secondary transfer nip. Then, the sheet secondarily transferred with the toner image is conveyed toward the fixing device.

Then, the correction mechanism tilts 1 roller member (steering roller) of the plurality of roller members that tension and support the intermediate transfer belt to the rotation axis direction, thereby correcting the belt offset of the intermediate transfer belt.

On the other hand, patent document 1 discloses a technique in which a cleaning member that is brought into contact with a steering roller via an intermediate transfer belt is tilted integrally with the steering roller in accordance with the tilt of the steering roller, for the purpose of cleaning the surface of the intermediate transfer belt. Specifically, the roller shaft of the steering roller is configured not to rotate in accordance with the rotation of the intermediate transfer belt or the steering roller. The supporting member for supporting the cleaning member is fixed to the housing of the cleaning device. Then, the cleaning member is directly fixed to the roller shaft of the steering roller.

In the conventional image forming apparatus described above, when the roller member (the switchback roller) is tilted in order to correct the belt deviation of the belt member (the intermediate transfer belt), distortion such as twisting may occur in the cleaning member. Then, such deformation of the cleaning member may cause a reduction in the cleaning ability of the cleaning member with respect to the belt member, and thus a cleaning failure may occur.

[ patent document 1 ] Japanese patent application laid-open No. 2010-19899

[ patent document 2 ] Japanese patent application laid-open No. 2017-203805

Disclosure of Invention

The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a belt device and an image forming apparatus in which a cleaning member is less likely to be deformed when a roller member is tilted.

The technical scheme of the invention relates to a belt device, which comprises: a belt member stretched and supported by a plurality of roller members; a shaft tilting member which is supported to be slidable with respect to a roller shaft of the 1 roller member and tilts the 1 roller member in conjunction with movement of the belt member in the width direction; and a support member that supports the roller shaft and is rotatable about a support shaft, wherein one end side in the width direction of the cleaning member is supported by the roller shaft so as to be rotatable relative thereto, and the other end side in the width direction of the cleaning member is supported by the roller shaft so as not to be rotatable.

According to the present invention, it is possible to provide a belt device and an image forming apparatus in which deformation of a cleaning member is less likely to occur when a roller member is tilted.

Drawings

Fig. 1 is a view showing the entire configuration of an image forming apparatus according to an embodiment of the present invention.

Fig. 2 is an enlarged configuration diagram showing a part of the imaging section.

Fig. 3 is a schematic diagram of an intermediate transfer belt device and its vicinity.

Fig. 4 is a cross-sectional view showing the widthwise ends of the intermediate transfer belt and the correction roller.

Fig. 5 (a) - (B) are cross-sectional views showing the operation of correcting the belt offset of the intermediate transfer belt.

Fig. 6 (a) to (B) are schematic plan views showing the operation of correcting the belt offset of the intermediate transfer belt.

Fig. 7 (a) - (B) show (a) an initial attitude chart of the correction roller, and (B) an attitude chart when (a) is stable.

Fig. 8 (a) - (B) are schematic perspective views showing the operation of the correction roller and the cleaning member.

Fig. 9 (a) is a side view of the support member on one end side in the width direction, and (B) is a side view of the support member on the other end side in the width direction.

Fig. 10 (a) - (B) are main partial views of an intermediate transfer belt device as a modification, and are cross-sectional views showing an operation of correcting belt deviation of the intermediate transfer belt.

Detailed Description

Hereinafter, embodiments used in the present invention will be described in detail with reference to the drawings. In the drawings, the same or corresponding portions are denoted by the same reference numerals, and detailed description thereof will be omitted as appropriate.

First, the overall configuration and operation of image forming apparatus 100 will be described with reference to fig. 1 and 2.

Fig. 1 is a configuration diagram of a printer as an image forming apparatus, and fig. 2 is an enlarged view of a part of an image forming portion thereof.

As shown in fig. 1, an intermediate transfer belt device 15 as a belt device is provided at the center of the image forming apparatus main body 100. The

image forming units

6Y, 6M, 6C, and 6K corresponding to the respective colors (yellow, magenta, cyan, and black) are arranged in parallel so as to face the intermediate transfer belt 8 (belt member) of the intermediate transfer belt device 15.

Referring to fig. 2, an image forming portion 6Y corresponding to yellow is configured by a photosensitive drum 1Y, a charging portion 4Y disposed around the photosensitive drum 1Y (photosensitive body), a developing portion 5Y, a cleaning portion 2Y, a lubricant supplying device 3, and a charge removing portion. Then, an image forming process (a charging process, an exposure process, a developing process, a transfer process, and a cleaning process) is performed on the photosensitive drum 1Y, and a yellow image is formed on the photosensitive drum 1Y.

The other 3

image forming units

6M, 6C, and 6K have substantially the same configuration as the image forming unit 6Y corresponding to yellow except that the color of the toner used is different, and form images corresponding to the respective toner colors. Hereinafter, the description of the other 3

image forming units

6M, 6C, and 6K is appropriately omitted, and only the image forming unit 6Y corresponding to yellow will be described.

Referring to fig. 2, the photosensitive drum 1Y is rotationally driven in the counterclockwise direction by the main motor. Then, the surface of the photosensitive drum 1Y is uniformly charged at the position of the charging section 4Y (charging step).

Then, the surface of the photosensitive drum 1Y reaches the irradiation position of the laser light L emitted from the exposure unit 7, and an electrostatic latent image corresponding to yellow is formed by exposure scanning in the width direction of the position (the main scanning direction which is a direction perpendicular to the paper surface of fig. 1 and 2) (exposure step).

Then, the surface of the photosensitive drum 1Y reaches a position opposed to the developing portion 5Y, and the electrostatic latent image is developed at the position, thereby forming a yellow toner image (developing step).

Thereafter, the surface of the photosensitive drum 1Y reaches the position where the intermediate transfer belt 8 and the primary transfer roller 99Y are opposed, and the toner image formed on the surface of the photosensitive drum 1 is primarily transferred onto the surface of the intermediate transfer belt 8 at this position (primary transfer step). At this time, a slight amount of untransferred toner remains on the photosensitive drum 1.

Thereafter, the surface of the photosensitive drum 1Y reaches a position facing the cleaning portion 2Y, and at this position, the untransferred toner remaining on the photosensitive drum 1Y is collected into the cleaning portion 2Y by the cleaning blade 2a (cleaning step).

Here, a lubricant supplying device 3 (lubricant supplying device for photoreceptor) including a lubricant supplying roller 3a, a solid lubricant 3b, a compression spring 3c, and the like is provided inside the cleaning portion 2Y. Then, the lubricant is reduced little by little from the solid lubricant 3b by the lubricant supply roller 3a rotating in the clockwise direction of fig. 2, and the lubricant is supplied to the surface of the photosensitive drum 1Y by the lubricant supply roller 3 a.

Finally, the surface of the photosensitive drum 1Y reaches a position facing the discharging unit, and the residual potential on the photosensitive drum 1 is removed at this position.

In this way, a series of image forming processes performed on the photosensitive drum 1Y is completed.

The image forming process described above is also performed in the other

image forming units

6M, 6C, and 6K in the same manner as in the yellow image forming unit 6Y. That is, the laser light L based on the image information is irradiated onto the

photosensitive drums

1M, 1C, and 1K of the

image forming units

6M, 6C, and 6K from the exposure unit 7 disposed above the image forming units. In detail, the exposure section 7 emits laser light L from a light source, and then causes the laser light L to scan through a polygon mirror that is rotationally driven while being irradiated onto the photosensitive drum via a plurality of optical elements. Further, as the exposure section 7, a member in which a plurality of LEDs are arranged in a width direction may be used.

Then, the toner images of the respective colors formed on the

photosensitive drums

1M, 1C, and 1K through the development steps of the respective developing

units

5M, 5C, and 5K are superimposed on the intermediate transfer belt 8 and primary-transferred. In this way, a color image is formed on the intermediate transfer belt 8.

Here, the intermediate transfer belt 8 as a belt member is stretched and supported by the plurality of roller members 16 to 19, 40, and is also moved around in the arrow direction in fig. 3 by the rotational drive of the drive roller 16 by the drive motor Mt 1.

The 4

primary transfer rollers

9Y, 9M, 9C, and 9K form primary transfer nips with the

photosensitive drums

1Y, 1M, 1C, and 1K, respectively, sandwiching the intermediate transfer belt 8 therebetween. Then, a transfer voltage (primary transfer bias) of a polarity opposite to that of the toner is applied to the

primary transfer rollers

9Y, 9M, 9C, and 9K.

Then, the intermediate transfer belt 8 travels in the arrow direction, and sequentially passes through the primary transfer nips of the

primary transfer rollers

9Y, 9M, 9C, and 9K. In this way, the toner images of the respective colors on the

photosensitive drums

1Y, 1M, 1C, and 1K are superimposed on the surface of the intermediate transfer belt 8 and are primarily transferred (this is a primary transfer step).

Then, the intermediate transfer belt 8 (belt member) on which the toner images of the respective colors are superimposed and primarily transferred reaches the position facing the secondary transfer belt 72. At this position, the intermediate transfer belt 8 and the secondary transfer belt 72 are sandwiched between the secondary transfer opposing roller 40 and the secondary transfer roller 70, and a secondary transfer nip is formed. Then, the 4-color toner image formed on the intermediate transfer belt 8 is secondarily transferred onto a sheet P such as paper conveyed to the position of the secondary transfer nip portion (secondary transfer step). At this time, the untransferred toner that has not been transferred onto the sheet P remains on the intermediate transfer belt 8.

After that, the intermediate transfer belt 8 reaches the position of the intermediate transfer cleaning portion 10. Then, at this position, the adhering matter such as the untransferred toner adhering to the surface of the intermediate transfer belt 8 is removed.

In this way, a series of transfer processes performed on the intermediate transfer belt 8 is completed.

Here, referring to fig. 1, the sheet P conveyed to the position of the secondary transfer nip is conveyed from the paper feed portion 26 disposed below the apparatus main body 100 through the paper feed roller 27, the registration roller pair 28, and the like.

More specifically, in the paper feed unit 26, a plurality of sheets P such as transfer paper are stacked and stored. Then, when the paper feed roller 27 is rotationally driven in the counterclockwise direction in fig. 1, the uppermost sheet P is fed toward between the rollers of the registration roller pair 28 via the first conveyance path K1.

The sheet P conveyed to the registration roller pair 28 (timing roller pair) is once stopped at a position where the roller nip of the rotationally driven registration roller pair 28 is stopped. Then, after timing of the color image on the intermediate transfer belt 8, the registration roller pair 28 is rotationally driven, and the sheet P is conveyed toward the secondary transfer nip. In this manner, a desired color image is transferred onto the sheet P.

Then, the sheet P on which the color image is transferred at the position of the secondary transfer nip is conveyed by the secondary transfer belt 72, separated from the secondary transfer belt 72, and then conveyed to the position of the fixing section 50 by the conveying belt 60. Then, at this position, the color image transferred on the surface is fixed to the sheet P by the heat and pressure of the fixing belt and the pressure roller (fixing process).

After that, the sheet P is discharged outside the apparatus by the pair of discharge rollers via the second conveyance path K2. The sheets P discharged to the outside of the apparatus by the pair of paper discharge rollers are sequentially stacked as output images on a stacking portion.

Thus, a series of image forming operations (printing operations) in the image forming apparatus are completed.

Further, when the "duplex printing mode" for printing on both sides (front and back sides) of the sheet P is selected, the sheet P after the fixing process on the front side is guided to the third conveying path K3, is not directly discharged as in the case where the "single-side printing mode" is selected, is reversed in the conveying direction, and is conveyed again to the position of the secondary transfer nip (secondary transfer device 69) via the fourth conveying path K4. Then, the back surface of the sheet P is subjected to image formation in the same image forming step (image forming operation) as described above at the position of the secondary transfer nip, and after the fixing step in the fixing section 50, the sheet P is discharged from the image forming apparatus main body 100 through the second conveying path K2.

Next, the configuration and operation of the developing section 5Y (developing device) in the image forming section will be described in more detail with reference to fig. 2.

The developing unit 5Y includes a developing roller 51Y facing each photosensitive drum 1Y, a thickness regulating blade 52Y facing the developing roller 51Y, two conveyance screws 55Y disposed in the developer housing unit, a concentration detection sensor 56Y for detecting the toner concentration in the developer, and the like. The developing roller 51Y is configured by a magnet fixedly provided inside, a sleeve rotating around the magnet, or the like. A two-component developer including a carrier and a toner is accommodated in the developer accommodating portion.

The developing unit 5Y configured as described above operates as follows.

The sleeve of the developing roller 51Y rotates in the arrow direction of fig. 2. Then, the developer G placed on the developing roller 51Y by the magnetic field formed by the magnet moves onto the developing roller 51Y with the rotation of the sleeve. Here, the developer G in the developing portion 5Y is adjusted so that the ratio of the toner in the developer G (toner concentration) is within a predetermined range. Specifically, when a toner concentration sensor provided in the developing unit 5Y detects that the toner concentration is low, new toner is supplied from the toner container 58 into the developing unit 5Y so that the toner concentration is within a predetermined range.

Then, the toner supplied from the toner container 58 into the developer housing section is mixed and stirred together with the developer G by the 2 conveyance screws 55Y, and circulates in the two separated developer housing sections (movement in the direction perpendicular to the paper surface in fig. 2). Then, the toner in the developer G is attracted to the carrier by frictional charging with the carrier, and is carried together with the carrier onto the developing roller 51Y by a magnetic force formed on the developing roller 51Y.

The developer G placed on the developing roller 51Y is conveyed in the direction of the arrow shown in fig. 2 and reaches the position of the thickness regulating blade 52Y. Then, the developer G on the developing roller 51Y is conveyed to a position (developing region) opposite to the photosensitive drum 1Y after an appropriate amount of developer is applied at that position. Then, the toner is attracted to the latent image formed on the photosensitive drum 1Y by the electric field formed in the development region. After that, the developer G remaining on the developing roller 51Y reaches above the developer housing portion with the rotation of the sleeve, and is detached from the developing roller 51Y at that position.

The toner container 58 is detachably (replaceably) provided to the developing unit 5Y (image forming apparatus 100). Then, when the new toner contained in the toner container 58 is emptied, the toner container 58 is removed from the developing unit 5Y (image forming apparatus 100) and replaced with new toner.

Next, the intermediate transfer belt device 15 in the present embodiment will be described in detail with reference to fig. 3 and the like.

Referring to fig. 3, the intermediate transfer belt device 15 as a belt device is configured by an intermediate transfer belt 8 as a belt member, four

primary transfer rollers

9Y, 9M, 9C, and 9K, a driving roller 16, a correcting roller 17, a pre-transfer roller 18, a tension roller 19, an intermediate transfer cleaning section 10, a secondary transfer counter roller 40, and the like.

The intermediate transfer belt 8 (belt member) is in contact with the four

photosensitive drums

1Y, 1M, 1C, and 1K that carry toner images of the respective colors, respectively, to form a primary transfer nip. The intermediate transfer belt 8 is stretched and supported mainly by five roller members (a driving roller 16, a correcting roller 17, a pre-transfer roller 18, a tension roller 19, and a secondary transfer counter roller 40).

In the present embodiment, the intermediate transfer belt 8 as a belt member is formed by dispersing a conductive material such as carbon black in a single layer or a plurality of layers of PVDF (polyvinylidene fluoride), ETFE (ethylene-tetrafluoroethylene copolymer), PI (polyimide), PC (polycarbonate), PAI (polyamide imide), TPE (thermoplastic elastomer), PEEK (polyether ether ketone), or the like. The volume resistivity of the intermediate transfer belt 8 is adjusted to 10 ⁶ ～10 ¹³ Omega cm, surface resistivity of the back side of the belt is adjusted to 10 ⁷ ～10 ¹³ Range of Ω cm. The thickness of the intermediate transfer belt 8 is set to be in the range of 20 to 200 μm. In the present embodiment, the thickness of the intermediate transfer belt 8 is set to about 60 μm, and the volume resistivity is set to 10 ⁹ And omega cm or so.

Further, if necessary, a release layer may be applied to the surface of the intermediate transfer belt 8. At this time, as a material for coating, a fluororesin such as ETFE (ethylene-tetrafluoroethylene copolymer), PTFE (polytetrafluoroethylene), PVDF (polyvinylidene fluoride), PEA (perfluoroalkoxy resin), FEP (tetrafluoroethylene-hexafluoropropylene copolymer), PVF (vinyl fluoride) may be used, but not limited thereto.

The

primary transfer rollers

9Y, 9M, 9C, and 9K are in contact with the corresponding

photosensitive drums

1Y, 1M, 1C, and 1K, respectively, via the intermediate transfer belt 8. Specifically, the yellow transfer roller 9Y is brought into contact with the yellow photosensitive drum 1Y via the intermediate transfer belt 8, the magenta transfer roller 9M is brought into contact with the magenta photosensitive drum 1M via the intermediate transfer belt 8, the cyan transfer roller 9C is brought into contact with the cyan photosensitive drum 1C via the intermediate transfer belt 8, and the black (black) transfer roller 9K is brought into contact with the black (black) photosensitive drum 1K via the intermediate transfer belt 8. The

primary transfer rollers

9Y, 9M, 9C, and 9K are elastic rollers each having a conductive sponge layer formed on a mandrel bar, and the volume impedance is adjusted to 10 ⁶ ～10 ¹² Omega (preferably 10) ⁷ ～10 ⁹ Ω) range。

The driving roller 16 is disposed so as to abut against the inner peripheral surface of the intermediate transfer belt 8 at a position downstream of the intermediate transfer belt in the traveling direction, in a state of being wound around the intermediate transfer belt 8 at a winding angle of about 120 degrees with respect to the four photosensitive drums. The drive roller 16 is rotationally driven in the clockwise direction in fig. 3 by a drive motor Mt1 controlled by the control section 90. Thereby, the intermediate transfer belt 8 travels in a predetermined travel direction (clockwise direction in fig. 3).

The driving roller 17 is disposed at a position on the upstream side in the traveling direction of the intermediate transfer belt 8, and is in contact with the inner circumferential surface of the intermediate transfer belt 8 in a state in which the intermediate transfer belt 8 is wound around at a winding angle of about 180 degrees with respect to the four photosensitive drums. In the intermediate transfer belt 8, a portion from the correction roller 17 to the drive roller 16 is set to be substantially a horizontal plane. The correction roller 17 is driven to rotate in the clockwise direction of fig. 3 as the intermediate transfer belt 8 travels.

In the present embodiment, the correction roller 17 is configured to be inclined with respect to the rotation axis direction to correct the belt deviation of the intermediate transfer belt 8 when the belt deviation occurs in the intermediate transfer belt 8, and this will be described in detail later with reference to fig. 4, 5, and the like.

An intermediate transfer cleaning portion 10 is provided in the position of the correction roller 17. The cleaning member 85 is provided in the intermediate transfer cleaning section 10, and abuts against the correction roller 17 via the intermediate transfer belt 8. Referring to fig. 4, cleaning member 85 is provided with a cleaning portion 85a (cleaning blade) which comes into contact with intermediate transfer belt 8 at a predetermined contact angle and contact pressure.

The tension roller 19 abuts against the outer peripheral surface of the intermediate transfer belt 8. The pre-transfer roller 18 and the secondary transfer counter roller 40 abut against the inner peripheral surface of the intermediate transfer belt 8.

The roller members 17 to 19, 40 other than the driving roller 16 are driven to rotate in the direction along the traveling direction of the intermediate transfer belt 8 as it travels.

Referring to fig. 3, the secondary transfer counter roller 40 is in contact with a secondary transfer roller 70 via the intermediate transfer belt 8 and a secondary transfer belt 72. The secondary transfer counter roller 40 is formed on the outer peripheral surface of a cylindrical mandrel bar made of stainless steel or the likeHas a volume impedance of 10 ⁷ ～10 ⁸ An elastic layer (layer thickness of about 5 mm) made of NBR rubber having se:Sup>A hardness (JIS-A hardness) of about 48 to 58 degrees and se:Sup>A value of Ω.

In the present embodiment, the secondary transfer counter roller 40 is electrically connected to the power supply unit 91, and a secondary transfer bias voltage of a high voltage of about-5 kV is applied from the power supply unit 91. The secondary transfer bias applied to the secondary transfer counter roller 40 is a secondary transfer bias (dc voltage) for secondarily transferring the toner image primarily transferred onto the surface of the intermediate transfer belt 8 on the sheet P conveyed to the secondary transfer nip, and has the same polarity (negative polarity in the present embodiment) as the polarity of the toner. Thus, the toner carried on the toner carrying surface (outer peripheral surface) of the intermediate transfer belt 8 is electrostatically moved from the secondary transfer opposing roller 40 side to the secondary transfer device 69 side by the secondary transfer electric field.

Next, the secondary transfer device 69 will be described in detail with reference to fig. 3.

Referring to fig. 3, the secondary transfer device 69 is constituted by a secondary transfer belt 72, a secondary transfer roller 70, a separation roller 71, a secondary transfer blade 73, and the like.

The secondary transfer belt 72 is an endless belt that is stretched and supported by a plurality of roller members (a secondary transfer roller 70 and a separation roller 71), and is formed of substantially the same material as the intermediate transfer belt 8. The secondary transfer belt 72 forms a secondary transfer nip portion in contact with the intermediate transfer belt 8, and simultaneously conveys the sheet P fed out from the secondary transfer nip portion.

The secondary transfer roller 70 and the secondary transfer counter roller 40 form a secondary transfer nip by sandwiching the intermediate transfer belt 8 and the secondary transfer belt 72 therebetween. The secondary transfer roller 70 is formed (coated) with an elastic layer having a hardness (Asker C hardness) of about 40 to 50 degrees on a hollow mandrel made of stainless steel, aluminum, or the like. The elastic layer of the secondary transfer roller 70 may be formed in a solid state or a foamed sponge state by dispersing a conductive filler such as carbon in a rubber material such as polyurethane, EPDM, or silicone, or by incorporating an ionic conductive material. In the present embodiment, the volume resistance of the elastic layer is set to 10 in order to suppress the concentration of the transfer current ^6.5 ～10 ^7.5 And omega is about. In addition, in the present embodiment, the secondary transfer roller 70 is grounded (grounded).

The secondary transfer roller 70 is driven to rotate in the counterclockwise direction of fig. 3 by the motor Mt2 controlled by the control unit 90, and rotates the secondary transfer belt 72 in the counterclockwise direction of fig. 3 and also rotates the separation roller 71 in the counterclockwise direction of fig. 3.

The separation roller 71 is disposed at a position downstream of the secondary transfer nip in the conveying direction of the sheet P. The sheet P fed out from the secondary transfer nip is conveyed along the secondary transfer belt 72 running in the counterclockwise direction in fig. 3, and then separated (curvature-separated) from the secondary transfer belt 72 at the position of the separation roller 71 by the secondary transfer belt 72 forming a curved surface along the outer periphery of the separation roller 71.

The secondary transfer blade 73 is in contact with the surface of the secondary transfer belt 72, and removes foreign matter such as toner or paper dust adhering to the surface of the secondary transfer belt 72. The secondary transfer blade 73 is in pressure contact with the secondary transfer roller 70 via the secondary transfer belt 72 so as to be in contact with the secondary transfer belt 72 in the opposite direction with respect to the traveling direction of the secondary transfer belt 72.

Hereinafter, the configuration and operation of the intermediate transfer belt device 15, which is a characteristic device in the present embodiment, will be described in detail.

Referring to fig. 4 and 5, in the intermediate transfer belt device 15 (belt device) of the present embodiment, the intermediate transfer belt 8 (belt member) is stretched and supported by the plurality of roller members 16 to 19, 40, and a correction mechanism 79 is provided to correct belt deviation of the intermediate transfer belt 8 by inclining 1 roller member (correction roller 17) of the plurality of roller members with respect to the rotation axis direction.

The correcting mechanism 79 corrects the belt offset of the intermediate transfer belt 8 by tilting the correcting roller 17 with respect to the rotation axis direction in conjunction with the belt offset operation of the intermediate transfer belt 8.

The roller shaft 17b on one end side in the width direction (the right side in fig. 7) of the correction roller 17 is supported by a movable plate 83 as a supporting member, and the roller shaft 17b on the other end side in the width direction (the left side in fig. 7) is supported by a fixed plate 84.

Specifically, referring to fig. 8, the movable plate 83 as a support member is provided on a frame (housing) of the apparatus 15 so as to be rotatable about a support shaft 83a while supporting the roller shaft 17b on one end side in the width direction. On the other hand, the fixing plate 84 also serves as a part of a frame (housing) of the device 15 by supporting the roller shaft 17b on the other end side in the width direction at a fixed position. That is, as shown in fig. 8 (a) and (B), the correction roller 17 is supported to be movable (tiltable) in approximately the vertical direction about one side (the other end side in the width direction) of the fixing plate 84.

In the present embodiment, it is preferable that the movable plate 83 (support member) and the frame of the device 15 are connected by a tension spring (urging member). In this case, when the roller shaft 17b is tilted downward by the shaft tilting member 81 (the correcting mechanism 79) as the belt of the intermediate transfer belt 8 is biased, the roller shaft 17b and the movable plate 83 are rotated upward around the support shaft 83a by the action of the tension spring. Then, the positions of the shaft tilting member 81 and the roller shaft 17b are stabilized at positions where the force to move due to the influence of the unevenness of the parallelism of the plurality of roller members for stretching and supporting the intermediate transfer belt 8, the variation of the roller diameters of the roller members and the circumferential length of the belt, etc., the force to tilt the roller shaft 17b downward by the shaft tilting member 81 (i.e., the force generated in association with the movement of the belt in the width direction), and the restoring force to move the roller shaft 17b upward by the tension spring are balanced with each other.

Here, as shown in fig. 4, the roller shaft 17b of the present embodiment is configured to be rotatable independently of the roller portion 17a of the correction roller 17 (1 roller member out of the plurality of roller members) relative thereto.

Specifically, the correction roller 17 includes a roller portion 17a that abuts against the inner peripheral surface of the intermediate transfer belt 8, and a roller shaft 17b that has a smaller outer diameter than the roller portion 17a, penetrates the roller portion 17a, and protrudes at both ends. The roller portion 17a is a hollow structure, and bearings are press-fitted into both ends in the width direction. Then, the roller shaft 17b is provided through a bearing so as to penetrate the hollow portion of the roller portion 17 a. Therefore, the roller shaft 17b can rotate independently of the rotation of the roller portion 17 a. That is, the roller shaft 17b does not rotate with the rotation of the roller portion 17a, and the roller portion 17a does not rotate with the rotation of the roller shaft 17b. On the other hand, the roller shaft 17b tilts together with the roller portion 17a by the operation of the correcting mechanism 79.

As shown in fig. 4 and 5, the correcting mechanism 79 is provided with a flange 80 (abutting member), a shaft tilting member 81 (guided member), an abutting member 82 (guiding member), and the like.

The shaft tilting member 81 is slidably supported in the width direction (axial direction) with respect to the roller shaft 17b of the correction roller 17 (1 roller member), and tilts the roller shaft 17b (correction roller 17) in conjunction with the movement (belt deviation) of the intermediate transfer belt 8 in the width direction (left-right direction in fig. 4 and 5).

A parallel surface 81a parallel to the rotation axis direction and an inclined surface 81b inclined to the parallel surface 81a are formed in the shaft inclined member 81. Then, the contact member 82 contacts the parallel surface 81a and the inclined surface 81b.

The shaft tilting member 81 is configured not to rotate with the travel of the intermediate transfer belt 8 and the rotation of the correction roller 17 (roller portion 17 a). Specifically, the shaft tilting member 81 is in contact with a protrusion for preventing rotation formed on a frame of the apparatus, so that its rotation is restricted to be movable only in the width direction.

The contact member 82 is formed to be capable of contacting the parallel surface and the inclined surface of the shaft inclined member 81. Then, in conjunction with the movement of the intermediate transfer belt 8 in the width direction, the roller shaft 17b (correction roller 17) is tilted by the sliding movement of the inclined surface 81b of the shaft tilting member 81 and the contact member 82.

The flange 80 is disposed so as to be capable of abutting against an end surface of the intermediate transfer belt 8, and is moved by being pushed by the intermediate transfer belt 8 in accordance with the movement of the intermediate transfer belt 8 in the width direction. The flange 80 is configured to be rotatable (rotatable) with the advance of the intermediate transfer belt 8 and the rotation of the correction roller 17 (roller portion 17 a). The shaft tilting member 81 is disposed at a position opposite to the intermediate transfer belt 8 so as to be capable of abutting against the flange 80.

In the present embodiment, when the belt is not deviated, a gap is provided between the flange 80 and the intermediate transfer belt 8 in the width direction, but a configuration in which such a gap is not provided may be adopted. In this case, the responsiveness of the belt correction can be improved.

The correcting mechanism 79 will be described further.

The flange 80 is held on the roller shaft 17b of the correction roller 17 so as to be slidable and rotatable. A contact portion 80a against which the end surface of the intermediate transfer belt 8 contacts when the intermediate transfer belt 8 is biased is formed in the flange 80. The outer diameter of the abutment portion 80a is sufficiently larger than the outer diameter of the correction roller 17 (roller portion 17 a) so as not to be ridden by the intermediate transfer belt 8.

The shaft tilting member 81 is provided on the roller shaft 17b of the correction roller 17 so as to be slidable but not rotatable at a position outside the flange 80 in the width direction. A parallel surface 81a and an inclined surface 81b are formed in the shaft tilting member 81. Even if the correction roller 17 rotates, the shaft tilting member 81 does not rotate.

The contact member 82 is fixed and held to the housing of the device 15 so as to face the shaft tilting member 81 on the roller shaft 17b. That is, the contact member 82 is non-rotatably held in the housing regardless of whether the roller portion 17a (the correction roller 17) is rotated or not.

The belt offset of the intermediate transfer belt 8 (i.e., the belt movement in the lateral direction in fig. 4 and 5) is corrected by the correction mechanism 79 configured in this manner.

Specifically, as shown in fig. 6 (a), the parallelism of the drive roller 16 and the correction roller 17 is deviated. In fig. 6 a, the right end of the correction roller 17 is tilted in the-X direction (toward the front side in the vertical direction of the paper) with respect to the drive roller 16. At this time, the intermediate transfer belt 8 is inclined rightward at the inclination angle θ as viewed from the correction roller 17 side, and the intermediate transfer belt 8 is deviated rightward by Ytan θ after advancing by the distance Y.

When the intermediate transfer belt 8 is biased in the right direction, as shown in fig. 5 (a), the end surface of the intermediate transfer belt 8 abuts against the abutting portion 80a of the flange 80, and the flange 80 slides in the right direction to push the shaft tilting member 81 in the right direction. When the shaft tilting member 81 is pushed rightward, the abutting member 82 abutting against the parallel surface 81a as shown in fig. 5 (a) abuts against the tilted surface 81B as shown in fig. 5 (B), and the tilt of the correction roller 17 along the tilted surface 81B is tilted as shown in fig. 5 (B) and 6 (B).

Then, as shown in fig. 6 (B) and 5 (B), when the right end portion of the correction roller 17 is inclined in the + X direction (the back side in the vertical direction of the paper surface), the intermediate transfer belt 8 is inclined in the left direction at the inclination angle θ 'as viewed from the correction roller 17 side, and the intermediate transfer belt 8 moves toward the left belt by the Ytan θ' after moving by the distance Y, thereby canceling the belt deviation in the right direction. Thus, the belt deviation of the intermediate transfer belt 8 is corrected by the correcting mechanism 79.

In the example of fig. 6, the belt deviation caused when the parallelism of the drive roller 16 and the correction roller 17 is deviated is described.

However, the belt of the intermediate transfer belt 8 may be deviated when the outer diameter of the driving roller 16 and the correcting roller 17 (or other roller members) is deviated, or when the circumference of the intermediate transfer belt 8 is deviated. However, even if such a belt deviation occurs, the intermediate transfer belt 8 is deviated in the opposite direction so as to correct the belt deviation after the correction roller 17 is inclined. Thus, the belt deviation of the intermediate transfer belt 8 is corrected by the correcting mechanism 79.

By using the correcting mechanism 79 configured in this way, the belt deviation of the intermediate transfer belt 8 is less likely to occur.

In particular, in the present embodiment, the roller shaft 17b (the correction roller 17) can be tilted with a simple and space-saving configuration by only sliding the contact member 82 relative to the inclined surface 81b of the shaft tilting member 81.

In the present embodiment, since the flange 80 configured and operating as described above is provided between the intermediate transfer belt 8 and the shaft tilting member 81, the force in the width direction of the intermediate transfer belt 8 can be directly transmitted to the shaft tilting member 81 via the flange 80, and stable belt deviation correction can be performed.

In the present embodiment, the flange 80 is configured to be rotatable, and the intermediate transfer belt 8 and the flange 80 do not rub against each other, so that the problem of abrasion of the end surface of the intermediate transfer belt 8 can be reduced. Further, since the shaft tilting member 81 does not rotate, it is not necessary to form the inclined surface 81b and the parallel surface 81a in the entire rotation direction, and thus it is possible to prevent the problem that the shaft tilting member 81 is increased in size.

In particular, in the present embodiment, the movable plate 83 (support member) and the shaft tilting member 81 are provided only on the roller shaft 17b on one end side in the width direction of the correction roller 17 (1 roller member), respectively, and are not provided on the roller shaft 17b on one side (other end side in the width direction) of the fixed plate 84, so that the size and cost of the device 15 can be reduced.

Here, in the intermediate transfer belt device 15 of the present embodiment, the cleaning member 85 for cleaning the intermediate transfer belt 8 is provided to face the correction roller 17 (1 roller member) with the intermediate transfer belt 8 (belt member) therebetween. The cleaning member 85 is formed by bonding a cleaning member 85a to a holding member formed of sheet metal or the like. In the present embodiment, a substantially plate-shaped cleaning blade made of urethane rubber or the like is used as the cleaning portion 85a, but felt, nonwoven fabric or the like may be used as the cleaning portion 85a. As shown by a broken line in fig. 4 and the like, the cleaning portion 85a abuts against the outer peripheral surface of the intermediate transfer belt 8 in the entire width direction to remove the toner, paper dust, and other deposits adhering to the intermediate transfer belt 8. Then, the adhering matter removed by the cleaning portion 85a (cleaning member 85) is collected into the intermediate transfer cleaning portion 10.

As shown in fig. 8, 9, and the like, one end side in the width direction (the side on which the movable plate 83 is provided) of the cleaning member 85 is supported to be rotatable relative to the roller shaft 17b, and the other end side in the width direction (the side on which the fixed plate 84 is provided) is supported to be non-rotatable on the roller shaft 17b.

Specifically, referring to fig. 8 and 9 (a), a cylindrical circular hole 85b1 is formed in the arm portion 85b on one end side in the width direction of the cleaning member 85, and a cylindrical circular hole 83b is also formed in the movable plate 83 (support member). Then, a roller shaft 17b (cylindrical shape) on one end side in the width direction is inserted into the circular holes 85b1 and 83b. With this configuration, the cleaning member 85 is cylindrically supported by the roller shaft 17b at one end in the width direction, and can rotate independently and relatively independently of the rotation of the roller shaft 17b.

On the other hand, referring to fig. 8 and 9 (B), a cylindrical D-cut circular hole 85c1 passing through a D-cut is formed in the arm portion 85c on the other end side in the width direction of the cleaning member 85, and a similar D-cut circular hole 84a is also formed in the fixed plate 84. Then, the roller shaft 17b on the other end side in the width direction (D-cut portion formed) is fitted into the D-cut circular holes 85c1 and 84a. With such a configuration, the other end side in the width direction of the cleaning member 85 is fixedly supported so as not to be rotatable relative to the roller shaft 17b. The method of fixedly supporting the other end side in the width direction of the cleaning member 85 is not limited to the method of forming the D-cut circular holes 85c1 and 84a as described above, and may be a method of fastening with screws, for example.

With such a configuration, even if the correction roller 17 is tilted in order to correct the belt offset of the intermediate transfer belt 8, deformation such as twisting is less likely to occur in the cleaning member 85.

Specifically, referring to fig. 8 and the like, when a belt deviation occurs in the intermediate transfer belt 8, the movable plate 83 (support member) is rotated about the support shaft 83a by the operation of the correction mechanism 79 described above, and the roller shaft 17b of the correction roller 17 is tilted. Then, the belt offset of the intermediate transfer belt 8 is corrected by the inclination of the roller shaft 17b.

At this time, since the cleaning member 85 is positioned with respect to the roller shaft 17b, when the roller shaft 17b is inclined, it is inclined integrally with the roller shaft 17b. Then, since the movable plate 83 moves in the rotational direction, the cleaning member 85 moves so as to twist in the width direction. However, since the side that moves by the movement of the movable plate 83 is rotatably supported by the cylinder with respect to the roller shaft 17b and the opposite side is fixedly supported by the fixed plate 84, the cleaning member 85 does not move in the rotational direction even if the movable plate 83 rotates. Therefore, even if the roller shaft 17b is inclined, the cleaning member 85 is not twisted, and the cleaning portion 85a can be brought into contact with the intermediate transfer belt 8 uniformly in the entire width direction. Thus, since the cleaning member 85 can satisfactorily clean the intermediate transfer belt 8, it is possible to reduce the occurrence of an abnormal image due to stain (poor cleaning) of the intermediate transfer belt 8. That is, the intermediate transfer belt device 15 according to the present embodiment can maintain good cleaning performance of the cleaning member 85 by reducing deformation of the cleaning member 85 while performing good belt deviation control.

Here, as shown in fig. 7, the shaft tilting member 81 (the correcting mechanism 79) and the movable plate 83 (the supporting member) of the intermediate transfer belt device 15 in the present embodiment are provided only on the roller shaft 17b on one end side in the width direction of the correcting roller 17 (the roller member 1).

Therefore, as shown in fig. 7a, initially, the correction roller 17 is provided so as to be inclined from a parallel state in advance, and from this state, the belt does not lean toward the other end side in the width direction (left side in fig. 7). When the belt deviation in the right direction in fig. 7 occurs, the correcting mechanism 79 operates to correct the belt deviation, and eventually, as shown in fig. 7 (B), the correcting roller 17 enters a stable posture.

< modification example >

Fig. 10 is a cross-sectional view showing an operation of correcting the belt deviation of the intermediate transfer belt 8 in the intermediate transfer belt device 15 as a modification, and corresponds to fig. 5 in the present embodiment.

As shown in fig. 10, the roller shaft 17b of the correction roller 17 in the modification is configured to be rotatable together with the roller portion 17a of the correction roller 17 (1 roller member).

Specifically, the correction roller 17 is provided with a roller portion 17a that abuts the inner peripheral surface of the intermediate transfer belt 8, and roller shafts 17b that have smaller outer diameters than the roller portion 17a and protrude from both ends of the roller portion 17 a. The roller shafts 17b may be formed by using 2 roller shafts 17b protruding from both ends of the

roller portion

17a, or 1 roller shaft 17b may be formed by penetrating the roller portion 17a and then protruding from both ends. In short, the roller portion 17a and the roller shaft 17b of the correction roller 17 in the present embodiment are integrated and integrally rotated.

As shown in fig. 10, the intermediate transfer belt device 15 of the modification is provided with a bearing 86 that rotatably supports the roller shaft 17b of the correction roller 17.

Then, the cleaning member 85 is supported by the roller shaft 17b via the bearing 86. In the modification, one end side in the width direction (the side where the movable plate 83 is provided) of the cleaning member 85 is also supported by the roller shaft 17b via the bearing 86 so as to be rotatable relative thereto, and the other end side in the width direction (the side where the fixed plate 84 is provided) is supported by the roller shaft 17b via the bearing 86 so as not to be rotatable.

Specifically, a circular hole 85b1 is formed in the arm portion 85b (see fig. 8) on one end side in the width direction of the cleaning member 85, and a circular hole 83b having a cylindrical shape is also formed in the movable plate 83 (support member). Then, the roller shaft 17b (cylindrical shape) on one end side in the width direction is inserted into the circular holes 85b1 and 83b through the bearing 86. With this configuration, the cleaning member 85 is cylindrically supported on one end side in the width direction by the roller shaft 17b via the bearing 86, and is capable of rotating independently and relatively independently of the rotation of the roller shaft 17b. In the modification, the roller shaft 17b rotates together with the roller portion 17a, but the one end side in the width direction of the cleaning member 85 is positioned to be rotatable regardless of such rotation.

On the other hand, the arm portion 85c on the other end side in the width direction of the cleaning member 85 is provided with a cylindrical D-cut circular hole portion 85c1 having a D-cut, and the fixed plate 84 is provided with a similar D-cut circular hole portion 84a. Then, bearings (having D notches formed therein) are fitted into the D-notch circular holes 85c1 and 84a, and the roller shaft 17b on the other end side in the width direction is rotatably inserted through the bearings. With this configuration, the other end side in the width direction of the cleaning member 85 is fixed and supported to be relatively non-rotatable with respect to the bearing. In the modification, the roller shaft 17b rotates together with the roller portion 17a, but the other end side in the width direction of the cleaning member 85 is positioned in a non-rotating manner regardless of such rotation.

In the intermediate transfer belt device 15 according to the modification having the above-described configuration, as in the present embodiment, one end side in the width direction of the cleaning member 85 positioned on the roller shaft 17b of the correction roller 17 is supported to be rotatable relative to the roller shaft 17b, and the other end side in the width direction is supported to be non-rotatable on the roller shaft 17b, so that even if the correction roller 17 is tilted in order to correct the belt deviation of the intermediate transfer belt 8, deformation such as twisting is unlikely to occur in the cleaning member 85.

As described above, the intermediate transfer belt device 15 (belt device) according to the present embodiment includes the shaft tilting member 81 for tilting the roller shaft 17b in conjunction with the movement of the intermediate transfer belt 8 (belt member) in the width direction, the cleaning member 85 for cleaning the intermediate transfer belt 8, and the movable plate 83 (support member) rotatable about the support shaft 83a while supporting the roller shaft 17b. Then, one end side in the width direction of the cleaning member 85 is supported to be rotatable relative to the roller shaft 17b, and the other end side in the width direction is supported to be non-rotatable to the roller shaft 17b.

Thus, when the correction roller 17 is tilted, the cleaning member 85 is less likely to be deformed.

In the present embodiment, the present invention is applied to the intermediate transfer belt device 15 that corrects the belt deviation of the intermediate transfer belt 8 as a belt member, but the application of the present invention is not limited to this, and the present invention can be applied to a belt device that corrects the belt deviation of a belt member such as the secondary transfer belt 72, a photoreceptor belt, a transfer conveyance belt, or a fixing belt.

In the present embodiment, the present invention is applied to the image forming apparatus 100 for forming a color image. In contrast, the present invention can be applied to an image forming apparatus that forms only a monochrome image.

Even in such a case, the same effects as those of the present embodiment can be obtained.

The present invention is not limited to the present embodiment, and it is obvious that the present embodiment can be appropriately modified within the scope of the technical idea of the present invention, in addition to the teaching of the present embodiment. The number, position, shape, and the like of the constituent members are not limited to those in the present embodiment, and an appropriate number, position, shape, and the like can be selected when carrying out the present invention.

Claims

1. A belt device, characterized by comprising:

a belt member stretched and supported by a plurality of roller members;

a shaft tilting member which is supported to be slidable with respect to a roller shaft of 1 of the roller members, and tilts 1 of the roller members in conjunction with movement of the belt member in the width direction;

a cleaning member which faces 1 of the roller members with the belt member interposed therebetween and cleans the belt member, and

a support member that supports the roller shaft and is rotatable about a support shaft,

one end side in the width direction of the cleaning member is supported to be rotatable relative to the roller shaft, and the other end side in the width direction is supported to be non-rotatable on the roller shaft.

2. The belt device according to claim 1, characterized in that:

the support member and the shaft tilting member are provided on the roller shafts on only one end side in the width direction of 1 of the roller members, respectively.

3. A band device according to claim 1 or 2, characterized in that:

the roller shafts are independent of the roller portions of 1 of the roller members and are relatively rotatable.

4. A band device according to claim 1 or 2, characterized in that:

the roller shaft is rotatable together with the roller portions of 1 of the roller members.

5. The belt device according to claim 4, characterized in that:

has a bearing for rotatably supporting the roll shaft,

the cleaning member is supported by the roller shaft via the bearing.

6. A band device according to claim 1 or 2, characterized in that:

has a flange which is provided so as to be capable of abutting against an end surface of the belt member, is rotatable with the travel of the belt member, and is moved by being pushed by the belt member with the movement of the belt member in the width direction,

the shaft tilting member is disposed so as to be capable of abutting against the flange at a position on the opposite side of the belt member, and is configured so as to form a tilting surface without rotating with the travel of the belt member,

a contact member capable of being formed in contact with the inclined surface of the shaft inclined member,

the roller shaft is inclined by sliding movement of the inclined surface of the shaft inclination member and the contact member in conjunction with movement of the belt member in the width direction.

7. An image forming apparatus, characterized in that:

the belt device according to any one of claims 1 to 6.