This patent application is based on and claims priority pursuant to 35 U.S.C. § 119(a) to Japanese Patent Application Nos. 2018-067412, filed on Mar. 30, 2018 and 2018-166143, filed on Sep. 5, 2018, in the Japan Patent Office, the entire disclosure of each of which is hereby incorporated by reference herein.
This disclosure relates to a belt device including a belt that rotates in a predetermined direction and an image forming apparatus including the belt device, such as a copier, a printer, a facsimile machine, or a multifunction peripheral (MFP) having at least two functions of the copier, printer, and facsimile machine.
There are known image forming apparatuses such as copiers and printers including a correction mechanism (a belt alignment device) to correct belt deviation of a belt such as an intermediate transfer belt.
According to embodiments of the present disclosure, an improved belt device includes a plurality of rollers, a belt stretched and supported around the plurality of rollers, a roller shaft included in one of the plurality of rollers and configured to rotate along with the one of the plurality of rollers, a shaft inclination member slidably supported by the roller shaft, a cleaning member opposed to the one of the plurality of rollers via the belt, a bearing configured to rotatably support the roller shaft, and a support configured to rotatably support the bearing. The shaft inclination member is configured to incline the roller shaft in conjunction with movement in which the belt moves in a width direction of the belt device. The cleaning member is configured to clean the belt. The bearing is configured to stationarily support the cleaning member.
A more complete appreciation of the disclosure and many of the attendant advantages thereof will be readily obtained as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawings, wherein:
The accompanying drawings are intended to depict embodiments of the present disclosure and should not be interpreted to limit the scope thereof. The accompanying drawings are not to be considered as drawn to scale unless explicitly noted. In addition, identical or similar reference numerals designate identical or similar components throughout the several views.
In describing embodiments illustrated in the drawings, specific terminology is employed for the sake of clarity. However, the disclosure of this patent specification is not intended to be limited to the specific terminology so selected, and it is to be understood that each specific element includes all technical equivalents that have the same function, operate in a similar manner, and achieve a similar result.
As used herein, the singular forms “a”, “an”, and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise.
It is to be noted that the suffixes Y, M, C, and K attached to each reference numeral indicate only that components indicated thereby are used for forming yellow, magenta, cyan, and black images, respectively, and hereinafter may be omitted when color discrimination is not necessary.
Embodiments of the present disclosure are described in detail with reference to drawings. It is to be understood that identical or similar reference numerals are assigned to identical or corresponding components throughout the drawings, and redundant descriptions are omitted or simplified below.
With reference to
As illustrated in
With reference to
The other three image forming devices 6M, 6C, and 6K have a similar configuration to that of the yellow image forming device 6Y except for the color of the toner used therein and form magenta, cyan, and black toner images, respectively. Thus, only the image forming device 6Y is described below and descriptions of the other three image forming devices 6M, 6C, and 6K are omitted.
With reference to
Then, the charged surface of the photoconductor drum 1Y reaches a position to receive a laser beam L emitted from an exposure device 7, and the photoconductor drum 1Y is scanned with the laser beam L in a width direction at the position, thereby forming an electrostatic latent image for yellow on the surface of the photoconductor drum 1Y (an exposure process). The width direction is a main-scanning direction perpendicular to the surface of the paper on which
The surface of the photoconductor drum 1Y carrying the electrostatic latent image reaches a position opposite the developing device 5Y, and the electrostatic latent image is developed into a toner image of yellow at the position (a development process).
When the surface of the photoconductor drum 1Y carrying the toner image reaches a position opposite a primary transfer roller 9Y via the intermediate transfer belt 8, the toner image is transferred from the photoconductor drum 1Y onto a surface of the intermediate transfer belt 8 at the position (a primary transfer process). After the primary transfer process, a certain amount of untransferred toner remains on the photoconductor drum 1Y.
When the surface of the photoconductor drum 1Y reaches a position opposite the cleaning device 2Y, a cleaning blade 2a collects the untransferred toner from the photoconductor drum 1Y into the cleaning device 2Y (a cleaning process).
The cleaning device 2Y includes a lubricant supply roller 3a, a solid lubricant 3b, and a compression spring 3c, which constitute a lubricant applicator 3 for the photoconductor drum 1Y. The lubricant supply roller 3a rotating clockwise in
Subsequently, the surface of the photoconductor drum 1Y reaches a position opposite the discharger, and the discharger removes a residual potential from the photoconductor drum 1Y.
Thus, a sequence of image forming processes performed on the photoconductor drum 1Y is completed.
The above-described image forming processes are performed in the image forming devices 6M, 6C, and 6K similarly to the yellow image forming device 6Y. That is, the exposure device 7 disposed above the image forming devices 6M, 6C, and 6K irradiates the photoconductor drums 1M, 1C, and 1K of the image forming devices 6M, 6C, and 6K with the laser beams L based on image data. Specifically, the exposure device 7 includes a light source to emit the laser beams L, multiple optical elements, and a polygon mirror that is rotated by a motor. The exposure device 7 directs the laser beams L to the photoconductor drums 1M, 1C, and 1K via the multiple optical elements while deflecting the laser beams L with the polygon mirror. Alternatively, an exposure device 7 in which a plurality of light emitting diodes (LEDs) is arranged side by side in the width direction can be used.
Then, the toner images formed on the photoconductor drums 1M, 1C, and 1K through the development process of the developing devices 5M, 5C, and 5K are primarily transferred therefrom and superimposed onto the intermediate transfer belt 8. Thus, a multicolor toner image is formed on the intermediate transfer belt 8.
The intermediate transfer belt 8 as the belt is stretched and supported around a plurality of rollers 16 through 19 and 40 and is rotated by the drive roller 16 driven by a drive motor Mt1 in a direction indicated by arrow A2 in
The four primary transfer rollers 9Y, 9M, 9C, and 9K are pressed against the corresponding photoconductor drums 1Y, 1M, 1C, and 1K, respectively, via the intermediate transfer belt 8 to form primary transfer nips. Transfer voltages (primary transfer biases) opposite in polarity to toner are applied to the primary transfer rollers 9Y, 9M, 9C, and 9K.
While rotating in the direction indicated by arrow A2 in
Then, the intermediate transfer belt 8 carrying the multicolor toner image reaches a position opposite a secondary transfer belt 72. The secondary-transfer backup roller 40 and a secondary transfer roller 70 press against each other via the intermediate transfer belt 8 and the secondary transfer belt 72, thereby forming a secondary transfer nip. The multicolor (four-color) toner image on the intermediate transfer belt 8 is transferred onto a sheet P (e.g., a paper sheet) conveyed to the secondary transfer nip (a secondary transfer process). At that time, toner that is untransferred onto the sheet P remains on the surface of the intermediate transfer belt 8.
Then, the intermediate transfer belt 8 reaches a position opposite a belt cleaner 10 of the intermediate transfer belt device 15. At this position, the belt cleaner 10 removes substances adhering to the intermediate transfer belt 8 (e.g., untransferred toner).
Thus, a series of image transfer processes performed on the intermediate transfer belt 8 is completed.
With reference to
Specifically, the sheet feeder 26 loads a plurality of sheets P (e.g., transfer sheets) layered. As the feed roller 27 rotates counterclockwise in
The registration roller pair (a timing roller pair) 28 temporarily stops rotating, stopping the sheet P with a leading edge of the sheet P nipped in the registration roller pair 28. The registration roller pair 28 resumes rotation to convey the sheet P to the secondary transfer nip, timed to coincide with the arrival of the multicolor toner image on the intermediate transfer belt 8. Thus, the desired multicolor toner image is transferred onto the sheet P.
The sheet P, onto which the multicolor toner image is secondarily transferred, is conveyed on the secondary transfer belt 72 and separated from the secondary transfer belt 72, and then a conveyance belt 60 conveys the sheet P to the fixing device 50. In the fixing device 50, a fixing belt and a pressing roller apply heat and pressure to the sheet P to fix the multicolor toner image on the sheet P (a fixing process).
The sheet P is conveyed through a second conveyance path K2 and ejected by an output roller pair to the outside of the image forming apparatus 100. The sheets P are sequentially stacked as output images on a stack tray.
Thus, a series of image forming processes (printing operations) performed by the image forming apparatus 100 is completed.
Thus, in single-side printing, the sheet P is ejected after the toner image is fixed on the front side of the sheet P. By contrast, in duplex printing to form toner images on both sides (front side and back side) of the sheet P, the sheet P is guided to a third conveyance path K3. After a direction of conveyance of the sheet P is reversed, the sheet P is conveyed again to the secondary transfer nip (a secondary transfer device 69) via a fourth conveyance path K4. Then, through the image forming processes (the printing operations) similar to those described above, the toner image is transferred onto the back side of the sheet P at the secondary transfer nip and fixed thereon by the fixing device 50, after which the sheet P is ejected from the image forming apparatus 100 via the second conveyance path K2.
Next, a detailed description is provided of a configuration and operations of the developing device 5Y with reference to
The developing device 5Y includes a developing roller 51Y opposed to the photoconductor drum 1Y, a doctor blade 52Y opposed to the developing roller 51Y, two conveying screws 55Y disposed in a developer storage of the developing device 5Y, and a toner concentration sensor 56Y to detect a toner concentration in the developer. The developing roller 51Y includes stationary magnets, a sleeve that rotates around the magnets, and the like. The developer storage contains a two-component developer G including carrier (carrier particles) and toner (toner particles).
The developing device 5Y with such a configuration operates as follows.
The sleeve of the developing roller 51Y rotates in a direction indicated by arrow A1 in
The two conveying screws 55Y stir and mix the developer G with the toner supplied from the toner container 58 to the developer storage while circulating the developer G in the developer storage separated into two compartments. In this case, the developer G moves in a direction perpendicular to the surface of the paper on which
The developer G on the developing roller 51Y is carried in the direction indicated by arrow Al in
The toner container 58 is detachably (replaceably) attached to the developing device 5Y (the image forming apparatus 100). When the toner container 58 runs out of fresh toner, the toner container 58 is detached from the developing device 5Y (the image forming apparatus 100) and replaced with a new one.
Next, with reference to
With reference to
The intermediate transfer belt (the belt) 8 is disposed in contact with the four photoconductor drums 1Y, 1M, 1C, and 1K bearing the toner images of the respective colors to form the primary transfer nips. The intermediate transfer belt 8 is mainly stretched taut around and supported by five rollers: the drive roller 16, the correction roller 17, the pre-transfer roller 18, the tension roller 19, and the secondary-transfer backup roller 40.
According to the present embodiment, the intermediate transfer belt 8 as the belt includes a single layer or multiple layers formed of such a material as polyvinylidene fluoride (PVDF), ethylene-tetrafluoroethylene copolymer (ETFE), polyimide (PI), polycarbonate (PC), polyamide imide (PAT), thermoplastic elastomer (TPE), and polyether ether ketone (PEEK), with a conductive material such as carbon black dispersed therein. The volume resistivity of the intermediate transfer belt 8 is adjusted within a range of from 106 to 1013 Ωcm, and the surface resistivity of the back surface of the intermediate transfer belt 8 is adjusted within a range of from 107 to 1013 Ω/sq. The thickness of the intermediate transfer belt 8 ranges from 20 to 200 μam. According to the present embodiment, the intermediate transfer belt 8 has a thickness of about 60 μm, and a volume resistivity of about 109 Ωcm.
In some embodiments, the intermediate transfer belt 8 may include a release layer on the surface of the intermediate transfer belt 8 as needed. Examples of a material usable for the release layer include, but are not limited to, fluorocarbon resins such as ETFE, polytetrafluoroethylene (PTFE), PVDF, perfluoroalkoxy polymer resin (PFA), fluorinated ethylene propylene (FEP), and polyvinyl fluoride (PVF).
The primary transfer rollers 9Y, 9M, 9C, and 9K are disposed in contact with the photoconductor drums 1Y, 1M, 1C, and 1K via the intermediate transfer belt 8, respectively. Specifically, the primary transfer roller 9Y for yellow is disposed in contact with the photoconductor drum 1Y for yellow via the intermediate transfer belt 8. The primary transfer roller 9M for magenta is disposed in contact with the photoconductor drum 1M for magenta via the intermediate transfer belt 8. The primary transfer roller 9C for cyan is disposed in contact with the photoconductor drum 1C for cyan via the intermediate transfer belt 8. The primary transfer roller 9K for black is disposed in contact with the photoconductor drum 1K for black via the intermediate transfer belt 8. Each of the primary transfer rollers 9Y, 9M, 9C, and 9K is an elastic roller including a core and a conductive foamed layer on the core. The volume resistivity of each of the primary transfer rollers 9Y, 9M, 9C, and 9K is adjusted within a range of from 106 to 1012 Ωcm, preferably from 107 to 109 Ωcm.
The drive roller 16 is disposed in contact with an inner circumferential surface of the intermediate transfer belt 8 by an angle of belt winding of about 120 degrees at a position downstream from the four photoconductor drums 1Y, 1M, 1C, and 1K in a direction of rotation of the intermediate transfer belt 8. The drive roller 16 is rotated clockwise in
The correction roller 17 is disposed in contact with the inner circumferential surface of the intermediate transfer belt 8 by the angle of belt winding of about 180 degrees at a position upstream from the four photoconductor drums 1Y, 1M, 1C, and 1K in the direction of rotation of the intermediate transfer belt 8. A portion of the intermediate transfer belt 8 from the correction roller 17 to the drive roller 16 is arranged approximately horizontal. The correction roller 17 is rotated clockwise in
In the present embodiment, when belt deviation of the intermediate transfer belt 8 occurs, the correction roller 17 is inclined relative to an axial direction of the drive roller 16 to correct the belt deviation. This configuration is described in detail later, with reference to
The belt cleaner 10 is disposed opposite the correction roller 17. The belt cleaner 10 includes a cleaning member 85 that contacts the correction roller 17 via the intermediate transfer belt 8. With reference to
The tension roller 19 contacts an outer circumferential surface of the intermediate transfer belt 8. The pre-transfer roller 18 and the secondary-transfer backup roller 40 contact the inner circumferential surface of the intermediate transfer belt 8.
As the intermediate transfer belt 8 rotates, the plurality of rollers 17 through 19 and 40 other than the drive roller 16 is rotated according to the direction of rotation of the intermediate transfer belt 8.
With reference to
According to the present embodiment, the secondary-transfer backup roller 40 is electrically connected to a power source 91, which outputs a high voltage of approximately −5 kV as a secondary transfer bias. With the secondary transfer bias output to the secondary-transfer backup roller 40, the toner image primarily transferred to the surface of the intermediate transfer belt 8 is secondarily transferred onto the sheet P conveyed to the secondary transfer nip. The secondary transfer bias has the same polarity as the polarity of toner. In the present embodiment, the secondary transfer bias is a direct current voltage and has a negative polarity. With this configuration, the toner carried on the outer circumferential surface (a surface bearing the toner) of the intermediate transfer belt 8 electrostatically moves from the secondary-transfer backup roller 40 side toward the secondary transfer device 69.
Next, the secondary transfer device 69 is described in detail below with reference to
With reference to
The secondary transfer belt 72 is an endless belt stretched taut around a plurality of rollers (i.e., the secondary transfer roller 70 and the separation roller 71). The secondary transfer belt 72 is made of a material similar to that of the intermediate transfer belt 8. The secondary transfer belt 72 contacts the intermediate transfer belt 8 to form the secondary transfer nip and conveys the sheet P fed from the secondary transfer nip.
The secondary-transfer backup roller 40 and the secondary transfer roller 70 press against each other via the intermediate transfer belt 8 and the secondary transfer belt 72, thereby forming the secondary transfer nip. The secondary transfer roller 70 includes a hollow core made of stainless steel or aluminum and an elastic layer (coating) on the core. The elastic layer has a hardness ranging from approximately 40 to 50 degrees on Asker C hardness scale. To form the elastic layer of the secondary transfer roller 70, for example, a rubber material, such as polyurethane, ethylene-propylene-diene monomer (EPDM), and silicone, is formed into a solid or foamed state as follows. A conductive filler, such as carbon, is dispersed in the rubber material. Alternatively, an ionic conductive material is included in the rubber material. According to the present embodiment, the elastic layer of the secondary transfer roller 70 has a volume resistivity ranging from 1065 to 1075 Ωcm to prevent concentration of a transfer current. In the present embodiment, the secondary transfer roller 70 is electrically grounded.
As the secondary transfer roller 70 is rotated counterclockwise in
The separation roller 71 is disposed downstream from the secondary transfer nip in the direction of conveyance of the sheet P. Ejected from the secondary transfer nip, the sheet
P is conveyed along the secondary transfer belt 72 rotating counterclockwise in
The secondary transfer cleaning blade 73 contacts the surface of the secondary transfer belt 72 to remove substances such as toner and paper dust adhering to the surface of the secondary transfer belt 72. The secondary transfer cleaning blade 73 is pressed against the secondary transfer roller 70 via the secondary transfer belt 72 against the direction of rotation of the secondary transfer belt 72.
Descriptions are given below of the configuration and operations of the intermediate transfer belt device 15 as the belt device.
With reference to
The correction mechanism 79 causes the correction roller 17 to be inclined relative to the axial direction of the drive roller 16 in conjunction with the movement in which the intermediate transfer belt 8 moves to one side in the width direction of the intermediate transfer belt device 15 (i.e., the belt deviation occurs), thereby correcting the belt deviation of the intermediate transfer belt 8.
Specifically, as illustrated in
As illustrated in
The bearing 84 has an inner diameter portion with an approximately circular cross-section and rotatably support the roller shaft 17b. That is, the roller shaft 17b of the correction roller 17 is rotatably supported by the bearings 84 at both ends of the correction roller 17.
With reference to
The intermediate transfer belt device 15 further includes a frame (a housing) 88 to rotatably support the plurality of rollers 16 through 19 and 40. In the present embodiment, the support 83, which rotatably supports the bearing 84, is supported by the frame 88 and is rotatable around a spindle 86 relative to the frame 88. The bearing 84 rotatably supports the roller shaft 17b as illustrated in
The support 83 and the frame 88 are coupled to each other via the tension spring (the biasing member) 87. As the shaft inclination member 81 (the correction mechanism 79) moves the roller shaft 17b of the correction roller 17 downward to incline the correction roller 17 in accordance with the belt deviation of the intermediate transfer belt 8, the tension spring 87 biases the roller shaft 17b to rotate the support 83 together with the roller shaft 17b upward around the spindle 86. The shaft inclination member 81 and the roller shaft 17b stabilize at a position where all forces balance. All forces include: force to move the intermediate transfer belt due to production tolerance, such as variance of parallelism of the plurality of rollers that stretches and supports the intermediate transfer belt 8, deviations of diameters of the plurality of rollers, or a deviation of circumference of the intermediate transfer belt 8; force to move the roller shaft 17b downward by the shaft inclination member 81 to incline the correction roller 17 (i.e., force generated according to movement of the intermediate transfer belt 8 in the width direction); and resilience of the tension spring 87 to move the roller shaft 17b upward.
In the present embodiment, the tension spring (the biasing member) 87 is provided in the intermediate transfer belt device 15. Accordingly, if the intermediate transfer belt 8 moves close to one side in the width direction of the intermediate transfer belt device 15, the correction mechanism 79 reliably returns the intermediate transfer belt 8 to the original position of the intermediate transfer belt 8.
As illustrated in
The shaft inclination member 81 is slidably supported by the roller shaft 17b of the correction roller 17, which is the one of the plurality of rollers. The shaft inclination member 81 inclines the roller shaft 17b (the correction roller 17) in conjunction with the belt deviation, the movement of the intermediate transfer belt 8 in the width direction (the left and right direction in
The shaft inclination member 81 includes a parallel surface 81a parallel to a rotation axis of the correction roller 17 and an inclined surface 81b inclined relative to the parallel surface 81a. The parallel surface 81a or the inclined surface 81b contacts the contact member 82.
The shaft inclination member 81 does not rotate in conjunction with the rotation of the intermediate transfer belt 8 or the rotation of the correction roller 17 (the roller shaft 17b).
Specifically, the shaft inclination member 81 contacts a projection for stopping rotation disposed on the frame 88 of the intermediate transfer belt device 15. The projection inhibits the shaft inclination member 81 from rotating.
The contact member 82 contacts the parallel surface 81a or the inclined surface 81b of the shaft inclination member 81. The contact member 82 slides on the inclined surface 81b of the shaft inclination member 81 in conjunction with the movement of the intermediate transfer belt 8 in the width direction, thereby inclining the roller shaft 17b (the correction roller 17).
The flange 80 can contact an end face of the intermediate transfer belt 8. As the intermediate transfer belt 8 moves in the width direction, the flange 80 is pushed by the intermediate transfer belt 8, causing the flange 80 to move. The flange 80 rotates in conjunction with the rotation of the intermediate transfer belt 8 or the correction roller 17 (the roller shaft 17b). The shaft inclination member 81 contacts the flange 80 at the opposite side to the intermediate transfer belt 8.
In the present embodiment, when the belt deviation does not occur, there is a clearance between the flange 80 and the intermediate transfer belt 8 in the width direction of the intermediate transfer belt device 15. Alternatively, the flange 80 and the intermediate transfer belt 8 can be provided without the clearance. In this case, responsibility of the belt alignment (the belt deviation correction) can be improved.
A further detailed description is given of the correction mechanism 79.
The flange 80 is slidable and rotatable relative to the roller shaft 17b of the correction roller 17. As the intermediate transfer belt 8 moves to one side in the width direction (i.e., belt deviation occurs), the end face of the intermediate transfer belt 8 contacts an abutment portion 80a of the flange 80. The abutment portion 80a has an outer diameter sufficiently larger than the correction roller 17 (the roller portion 17a) so that the intermediate transfer belt 8 does not ride over the flange 80. The flange 80 rotates in conjunction with rotation of the correction roller 17.
The shaft inclination member 81 is disposed outboard of the flange 80 in the width direction. The shaft inclination member 81 is slidable and is not rotatable relative to the roller shaft 17b of the correction roller 17. The shaft inclination member 81 includes the parallel surface 81a and the inclined surface 81b. The shaft inclination member 81 does not rotate when the correction roller 17 rotates.
The contact member 82 is stationarily secured to the frame (the housing) 88 of the intermediate transfer belt device 15 and opposed to the shaft inclination member 81 above the roller shaft 17b. That is, the contact member 82 is secured so as not to rotate, irrespective of the rotation of the roller shaft 17b (the correction roller 17).
With such a configuration of the correction mechanism 79, the belt deviation of the intermediate transfer belt 8 (i.e., the movement of the intermediate transfer belt 8 in the left and right direction in
Specifically, as illustrated in
As the intermediate transfer belt 8 moves to the right, the end face of the intermediate transfer belt 8 contacts the abutment portion 80a of the flange 80 as illustrated in
As illustrated in
In the example in
However, the belt deviation of the intermediate transfer belt 8 may occur due to the deviations of outer diameters of the plurality of rollers such as the drive roller 16, the correction roller 17, or the other rollers, or a deviation of outer circumference diameter of the intermediate transfer belt 8. Even if such a belt deviation occurs, the correction roller 17 is inclined, causing the intermediate transfer belt 8 to move in opposite direction to correct the belt deviation. Thus, the correction mechanism 79 corrects the belt deviation of the intermediate transfer belt 8.
With such a configuration of the correction mechanism 79, the belt deviation of the intermediate transfer belt 8 is unlikely to occur. In particular, in the present embodiment, the roller shaft 17b (the correction roller 17) can be inclined by such a simple, space-saving configuration in which the contact member 82 relatively slides on the inclined surface 81b of the shaft inclination member 81.
In the present embodiment, since the flange 80 is disposed between the intermediate transfer belt 8 and the shaft inclination member 81 and operated as described above, the flange 80 directly transmits force, in which the intermediate transfer belt 8 moves to one side in the width direction, to the shaft inclination member 81. Therefore, the belt deviation can be stably corrected.
In the present embodiment, the flange 80 is rotated in conjunction with the rotation of the intermediate transfer belt 8. Therefore, since the intermediate transfer belt 8 and the flange 80 are not rubbed together, an inconvenience that the end face of the intermediate transfer belt 8 abrades can be minimized. Further, since the shaft inclination member 81 does not rotate, it is not necessary to form the inclined surface 81b and the parallel surface 81a across a circumferential direction of the correction roller 17, thereby preventing the shaft inclination member 81 from increasing in size.
As described above, the roller shaft 17b of the correction roller 17 is rotated in conjunction with the correction roller 17 (the roller portion 17a). Accordingly, the shaft inclination member 81 slides on the roller shaft 17b when the intermediate transfer belt 8 moves to one side in the width direction during rotation and the shaft inclination member 81 is displaced. At that time, a coefficient of kinetic friction between the roller shaft 17b and the shaft inclination member 81 is smaller than a coefficient of static friction between the roller shaft 17b and the shaft inclination member 81. Therefore, with such a configuration in which the roller shaft 17b is rotated in conjunction with the correction roller 17 (the roller portion 17a), frictional force between the roller shaft 17b and the shaft inclination member 81 is lowered as compared with a configuration in which the roller shaft 17b is not rotated in conjunction with the correction roller 17 (the roller portion 17a). Accordingly, the shaft inclination member 81 can be reliably displaced even if force in which the intermediate transfer belt 8 moves the shaft inclination member 81 is small. Accordingly, a load on the end face of the intermediate transfer belt 8 can be reduced, thereby extending the life of the intermediate transfer belt 8. With such a configuration, the belt deviation can be reliably corrected.
The intermediate transfer belt device 15 according to the present embodiment includes the cleaning member 85 opposed to the correction roller 17 (i.e., the one of the plurality of rollers) via the intermediate transfer belt (the belt) 8 to clean the intermediate transfer belt 8. The cleaning member 85 includes a holder made of sheet metal and the cleaning portion 85a bonded to the holder. In the present embodiment, the cleaning portion 85a is the cleaning blade that is plate-shaped and made of urethane rubber. Alternatively, the cleaning portion 85a can be made of felt or nonwoven fabric. As indicated by the dashed line in
As illustrated in
Specifically, an outer circumference of the bearing 84 is D-shaped (i.e., processed by D cut), and an arm of the cleaning member 85 has a D-shaped hole into which the bearing 84 with D-shape fits. As a result, the cleaning member 85 is supported by the bearing 84 and is not rotatable relative to the bearing 84. On the other hand, as described above, the bearing 84 is rotatably supported by the support 83, and the roller shaft 17b is rotatably supported be the bearing 84. Therefore, the cleaning member 85 and the bearing 84 rotate together but independently rotate relative to the roller shaft 17b (the correction roller 17).
Thus, in the present embodiment, the cleaning member 85 is supported by the roller shaft 17b via the bearing 84, and the bearing 84 is coaxial to the roller shaft 17b. Accordingly, the intermediate transfer belt 8 and the cleaning member 85 are accurately positioned relative to the roller shaft 17b, and the position relation between the intermediate transfer belt 8 and the cleaning member 85 (the cleaning portion 85a) can be maintained with high accuracy. That is, as illustrated in
In the present embodiment, since the cleaning member 85 is rotatable relative to the roller shaft 17b (and the roller portion 17a), the contact state of the cleaning member 85 relative to the intermediate transfer belt 8 can be maintained with high accuracy.
That is, when the roller shaft 17b (the correction roller 17) is inclined to correct the belt deviation of the intermediate transfer belt 8, if the cleaning member 85 is about to twist, the cleaning member 85 is rotated relative to the roller shaft 17b by rigidity of the cleaning member 85 in a direction in which the twist of the cleaning member 85 is eliminated. As a result, an inconvenience that the cleaning member 85 twists in the width direction is minimized. Therefore, an inconvenience that the cleaning ability of the cleaning member 85 relative to the intermediate transfer belt 8 decreases due to the twist of the cleaning member 85 is minimized.
As illustrated in
As illustrated in
Thus, since the shaft inclination member 81 (the correction mechanism 79) is disposed at each of both ends of the correction roller 17, the inclination of the correction roller 17 is small as compared with the intermediate transfer belt device 15 with the shaft inclination member 81 (the correction mechanism 79) disposed at one end of the correction roller 17.
As illustrated in
The cleaning member 85 includes a contact portion (a projection) 85b that can contact the stopper 89 at the center of the cleaning member 85 in the width direction.
With such a configuration, even if the cleaning member 85 receives force to rotate the cleaning member 85 around the rotation axis of the correction roller 17 due to sliding resistance with the intermediate transfer belt 8, the contact of the contact portion 85b with the stopper 89 prevents the cleaning member 85 from rotating. As a result, the position of the cleaning member 85 in a rotation direction is determined, and an inconvenience that the cleaning member 85 twists is minimized.
As illustrated in
As illustrated in
With such a configuration, the cleaning member 85 is supported by the roller shaft 17b via the bearing 84, and the bearing 84 is coaxial with the roller shaft 17b. Accordingly, correction of the belt deviation is satisfactorily performed, and the position relation between the intermediate transfer belt 8 and the cleaning member 85 can be reliably maintained.
Further, since the cleaning member 85 is rotatable relative to the roller shaft 17b, the cleaning member 85 does not twist, the contact state of the cleaning member 85 relative to the intermediate transfer belt 8 can be maintained with high accuracy.
In the first variation, the shaft inclination member 81 (the correction mechanism 79) is disposed on the roller shaft 17b at one end of the correction roller 17. This configuration can reduce the number of components and the cost of the intermediate transfer belt device 15 as compared with the intermediate transfer belt device 15 in which the shaft inclination member 81 (the correction mechanism 79) is disposed on the roller shaft 17b at each of both ends of the correction roller 17.
As illustrated in
The roller shaft 17b of the correction roller 17 (the one of the plurality of rollers) according to the second variation is different from that of the above-described embodiment.
In the second variation, the roller shaft 17b independently rotates relative to the roller portion 17a. Specifically, the roller portion 17a is a hollow structure, and bearings are pressed into both ends of the hollow structure in the width direction. The roller shaft 17b penetrates a hollow part of the roller portion 17a and supports the roller portion 17a via the bearings. Therefore, the roller shaft 17b does not rotate along with rotation of the roller portion 17a, and the roller portion 17a does not rotate along with rotation of the roller shaft 17b. Meanwhile, the roller shaft 17b and roller portion 17a are inclined together by operation of the correction mechanism 79.
As illustrated in
As illustrated in
Thus, in the second variation, the cleaning member 85 is directly supported by the roller shaft 17b. Accordingly, the intermediate transfer belt 8 and the cleaning member 85 are more accurately positioned relative to the roller shaft 17b. Therefore, the position relation between the intermediate transfer belt 8 and the cleaning member 85 (the cleaning portion 85a) can be maintained with further accuracy.
In the second variation, since the cleaning member 85 is rotatable relative to the roller portion 17a, the contact state of the cleaning member 85 relative to the intermediate transfer belt 8 can be maintained with high accuracy. That is, when the roller shaft 17b (the correction roller 17) is inclined to correct the belt deviation of the intermediate transfer belt 8, if the cleaning member 85 is about to twist, the cleaning member 85 is rotated relative to the roller portion 17a by rigidity of the cleaning member 85 in the direction in which the twist of the cleaning member 85 is eliminated, thereby preventing the cleaning member 85 from twisting. Therefore, an inconvenience that the cleaning ability of the cleaning member 85 relative to the intermediate transfer belt 8 decreases due to the twist of the cleaning member 85, and cleaning failure occurs is minimized.
Note that, the configuration of the stopper 89 as described above with reference to
As described above, the intermediate transfer belt device 15 according to the above-described embodiments includes the roller shaft 17b that rotates along with the correction roller 17 (the one of the plurality of rollers), the shaft inclination member 81 configured to incline the roller shaft 17b in conjunction with movement in which the intermediate transfer belt 8 moves to one side in the width direction of the intermediate transfer belt device 15, the cleaning member 85 configured to clean the intermediate transfer belt 8, the bearing 84 configured to rotatably support the roller shaft 17b, and the support 83 configured to rotatably support the bearing 84. The cleaning member 85 is stationarily supported by the bearing 84.
As a result, when the correction roller 17 is inclined, the cleaning member 85 is unlikely to twist.
Therefore, according to the present disclosure, a belt device and an image forming apparatus can be provided in which a cleaning member is unlikely to twist when a roller is inclined.
It is to be noted that the above-described embodiments according to the present disclosure is applied to, but not limited to, the intermediate transfer belt device 15 in which the belt deviation of the intermediate transfer belt 8 as a belt is corrected. For example, the present disclosure can be applied to a belt device in which the belt deviation of a belt, such as the secondary transfer belt 72, a photoconductor belt, a transfer conveyance belt, a fixing belt, and the like, is corrected.
Further, in the above-described embodiments, the present disclosure is applied to the image forming apparatus 100 that forms the color image. On the other hand, the present disclosure can also be applied to an image forming apparatus that forms only a monochrome image.
In such configurations, effects similar to those described above are also attained.
The above-described embodiments are illustrative and do not limit the present disclosure. Thus, numerous additional modifications and variations are possible in light of the above teachings. It is therefore to be understood that within the scope of the present disclosure, the present disclosure may be practiced otherwise than as specifically described herein. The number, position, and shape of the components described above are not limited to those embodiments described above. Desirable number, position, and shape can be determined to perform the present disclosure.
Number | Date | Country | Kind |
---|---|---|---|
2018-067412 | Mar 2018 | JP | national |
2018-166143 | Sep 2018 | JP | national |