Belt conveying device and image forming apparatus

Abstract

To provide a belt conveying device that has a miniaturized configuration and can stop meandering of a belt.SOLUTION: A correction mechanism 50 of a belt conveying device 40 comprises a pair of inclined bearings 52 and a pair of body guides 54, and corrects meandering of an intermediate transfer belt 41. The pair of inclined bearings 52 have a pair of inclined parts 521 that are inclined symmetrically with respect to an axial direction Dx of a tension roller 43, and are movable in the axial direction Dx. The pair of body guides 54 are in contact with the pair of inclined parts 521, and move one end side in the axial direction Dx of the tension roller 43 in a direction orthogonal to the axial direction Dx together with the pair of inclined bearings 52 moving due to the meandering of the intermediate transfer belt 41. The pair of inclined parts 521 and the pair of body guides 54 are arranged inside both ends in the axial direction Dx of the tension roller 43 when seen from the direction orthogonal to the axial direction Dx.SELECTED DRAWING: Figure 3

Description

Technical Field

[0004] , , , , , , , , , , , , , ,

[0005] ,

[0003]

[0001] The present invention relates to a belt conveyance device and an image forming apparatus.

Background Art

[0002] As a component of an image forming apparatus such as a copying machine or a printer, for example, an intermediate transfer belt on which different color toner images formed by a plurality of photoreceptor drums are sequentially superimposed and primarily transferred, and then the toner image is secondarily transferred onto a sheet, or a conveyance belt that adsorbs and conveys the sheet, etc., a belt conveyance device including an endless belt is known. In the belt conveyance device, there has been a problem that the belt is displaced in the axial direction of the roller on which the belt is rotatably installed, and the belt meanders.

[0003] Regarding this problem, a technique for stopping the meandering of the belt by adjusting the alignment of the rollers has been proposed. An example of the prior art for stopping the meandering of the belt by adjusting the alignment of the rollers is disclosed in Patent Document 1.

[0004] The conventional image forming apparatus disclosed in Patent Document 1 includes a shaft inclination portion and a shaft guide portion that incline the roller by the movement of the belt stretched over the roller in the axial direction of the roller. The shaft guide portion contacts the inclined surface of the shaft inclination portion and is fixed so as not to move. In this image forming apparatus, when the belt moves (meanders) in the axial direction of the roller, the position of the inclined surface that contacts the shaft guide portion is displaced in the vertical direction, and the shaft inclination portion and the roller incline. When the roller inclines, the belt greatly inclines and moves in a direction to return to its original position with respect to the axial direction of the roller, and the meandering of the belt can be corrected.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of the Invention

[0006] However, in conventional technology, the correction mechanism for correcting belt meandering is located on the outside in the axial direction of the rollers over which the belt is stretched, which has the drawback of making the device larger in the axial direction of the rollers.

[0007] The present invention has been made in view of the above points, and aims to provide a belt conveying device and an image forming device that can stop the meandering of the belt in a miniaturized configuration. [Means for solving the problem]

[0008] To solve the above problems, the belt conveying device of the present invention comprises an endless belt, a plurality of rollers, and a correction mechanism. The plurality of rollers rotatably mount the belt. The correction mechanism corrects the meandering of the belt relative to the rollers. The correction mechanism comprises a pair of inclined bearings and a pair of body guides. The pair of inclined bearings have a pair of inclined portions that are inclined symmetrically with respect to the axial direction of the roller, and rotatably support the shaft portion of any of the plurality of rollers and are movable in the axial direction of the roller. The pair of body guides contact the pair of inclined portions and, together with the pair of inclined bearings that move in the axial direction of the roller as the belt meanders, move one end of the roller in the axial direction in a direction perpendicular to the axial direction. The pair of inclined portions and the pair of body guides are positioned inward from the axial ends of the roller when viewed from a direction perpendicular to the axial direction of the roller. [Effects of the Invention]

[0009] According to the configuration of the present invention, the pair of inclined parts and the pair of main body guides of the correction mechanism for tilting the roller are not located outside the axial ends of the roller. In other words, the device can be miniaturized in the axial direction of the roller. Therefore, it is possible to stop the meandering of the belt with a miniaturized configuration. [Brief explanation of the drawing]

[0010] [Figure 1] This is a schematic cross-sectional front view of an image forming apparatus according to one embodiment of the present invention. [Figure 2] Figure 1 is a schematic cross-sectional front view of the belt conveying device of the image forming apparatus. [Figure 3] This is a side view of the belt conveying device according to the first embodiment. [Figure 4] Figure 3 is a partial side view of the area around the tension roller of the belt conveying device. [Figure 5] Figure 4 is a partial side view of the area around the tension roller, showing the intermediate transfer belt in a meandering state. [Figure 6] This is a partial side view of the area around the tension roller of a belt conveying device according to a second embodiment of the present invention. [Figure 7] This is a partial side view of the area around the tension roller of a belt conveying device according to a third embodiment of the present invention. [Modes for carrying out the invention]

[0011] Embodiments of the present invention will be described below with reference to the drawings. However, the present invention is not limited to the following.

[0012] Figure 1 is a schematic cross-sectional front view of the image forming apparatus 1 of the embodiment. Figure 2 is a schematic cross-sectional front view of the belt conveying device of the image forming apparatus 1 of Figure 1. An example of the image forming apparatus 1 of this embodiment is a tandem-type color printer that transfers a toner image to paper S using an intermediate transfer belt 41. The image forming apparatus 1 may be a so-called multifunction device equipped with functions such as printing, scanning (image reading), and facsimile transmission.

[0013] As shown in Figure 1, the image forming apparatus 1 comprises a paper feeding unit 3, a paper transport unit 4, an exposure unit 5, an image forming unit 20, a transfer unit 30, a fixing unit 6, a paper discharge unit 7, and a control unit 8, all located on its main body 2.

[0014] The paper feed unit 3 is located at the bottom of the main body 2. The paper feed unit 3 receives multiple sheets of paper (recording medium) S before printing and separates and feeds out the paper S one sheet at a time during printing. The paper transport unit 4 extends vertically along the side wall of the main body 2. The paper transport unit 4 transports the paper S fed from the paper feed unit 3 to the secondary transfer unit 33 and the fixing unit 6, and then discharges the fixed paper S from the paper discharge port 4a to the paper discharge unit 7. The exposure unit 5 is located above the paper feed unit 3. The exposure unit 5 irradiates the image forming unit 20 with laser light controlled based on image data.

[0015] The image forming unit 20 is positioned above the exposure unit 5 and below the intermediate transfer belt 41. The image forming unit 20 includes an image forming unit 20Y for yellow, an image forming unit 20C for cyan, an image forming unit 20M for magenta, and an image forming unit 20B for black. These four image forming units 20 have the same basic configuration. Therefore, in the following description, the identification symbols "Y," "C," "M," and "B" representing each color may be omitted unless specifically required.

[0016] The image forming unit 20 includes a photoreceptor drum (image carrier) 21 that is rotatably supported in a predetermined direction (clockwise in Figures 1 and 2). The image forming unit 20 further includes a charging unit 22, a developing unit 23, and a drum cleaning unit 24 around the photoreceptor drum 21, along its rotational direction. A primary transfer unit 32 is positioned between the developing unit 23 and the drum cleaning unit 24.

[0017] The photoreceptor drum 21 has a photosensitive layer on its outer peripheral surface. The charging unit 22 charges the outer peripheral surface of the photoreceptor drum 21 to a predetermined potential. The exposure unit 5 exposes the outer peripheral surface of the photoreceptor drum 21 charged by the charging unit 22, and forms an electrostatic latent image of the document image on the outer peripheral surface of the photoreceptor drum 21. The developing unit 23 supplies toner to this electrostatic latent image for development and forms a toner image. Each of the four image forming units 20 forms a toner image of a different color. The drum cleaning unit 24 removes and cleans toner and the like remaining on the outer peripheral surface of the photoreceptor drum 21 after the toner image is primarily transferred to the outer peripheral surface of the intermediate transfer belt 41. In this way, the image forming unit 20 forms an image (toner image) to be transferred to the paper S later.

[0018] The transfer unit 30 includes a belt conveyance device 40, primary transfer units 32Y, 32C, 32M, 32B, a secondary transfer unit 33, and a belt cleaning unit 34. The belt conveyance device 40 is disposed above the four image forming units 20. The belt conveyance device 40 includes an intermediate transfer belt 41 that is rotatably supported in a predetermined direction (counterclockwise in FIGS. 1 and 2). The intermediate transfer belt 41 is an endless intermediate transfer body on which the toner images formed on the outer peripheral surfaces of the photoreceptor drums 21 in each of the four image forming units 20 are sequentially overlapped and primarily transferred. The four image forming units 20 are arranged in a so-called tandem method in a line from the upstream side to the downstream side in the rotation direction of the intermediate transfer belt 41.

[0019] The primary transfer units 32Y, 32C, 32M, 32B are disposed above the image forming units 20Y, 20C, 20M, 20B of each color, sandwiching the intermediate transfer belt 41. The secondary transfer unit 33 is disposed upstream of the fixing unit 6 with respect to the paper conveyance direction of the paper conveyance unit 4 and downstream of the four image forming units 20Y, 20C, 20M, 20B with respect to the rotation direction of the intermediate transfer belt 41. The belt cleaning unit 34 is disposed downstream of the secondary transfer unit 33 with respect to the rotation direction of the intermediate transfer belt 41.

[0020] The primary transfer unit 32 transfers the toner image formed on the outer peripheral surface of the photosensitive drum 21 to the intermediate transfer belt 41. In other words, the toner image is primarily transferred to the outer peripheral surface of the intermediate transfer belt 41 by the primary transfer units 32Y, 32C, 32M, and 32B for each color. Then, as the intermediate transfer belt 41 rotates, the toner images of the four image forming units 20 are continuously and successively transferred to the intermediate transfer belt 41 at a predetermined timing, whereby a color toner image in which the toner images of yellow, cyan, magenta, and black are superimposed is formed on the outer peripheral surface of the intermediate transfer belt 41.

[0021] The color toner image on the outer peripheral surface of the intermediate transfer belt 41 is transferred to the sheet S that has been sent in synchronization by the sheet conveyance unit 4 at the secondary transfer nip formed in the secondary transfer unit 33. The belt cleaning unit 34 removes and cleans the deposits such as toner remaining on the outer peripheral surface of the intermediate transfer belt 41 after secondary transfer. In this way, the transfer unit 30 transfers (records) the toner image formed on the outer peripheral surface of the photosensitive drum 21 to the sheet S.

[0022] The fixing unit 6 is disposed above the secondary transfer unit 33. The fixing unit 6 heats and presses the sheet S onto which the toner image has been transferred to fix the toner image on the sheet S.

[0023] The sheet discharge unit 7 is disposed above the transfer unit 30. The sheet S on which the toner image has been fixed and the printing is completed is conveyed to the sheet discharge unit 7. The sheet discharge unit 7 allows the printed sheet (printed matter) to be taken out from above.

[0024] The control unit 8 includes a CPU, an image processing unit, a memory unit, and other electronic circuits and electronic components (none of which are shown). The CPU controls the operation of each component provided in the image forming apparatus 1 based on control programs and data stored in the memory unit, and performs processing related to the functions of the image forming apparatus 1. The paper feeding unit 3, paper transport unit 4, exposure unit 5, image forming unit 20, transfer unit 30, and fixing unit 6 each receive individual commands from the control unit 8 and perform printing on the paper S in conjunction with each other. The memory unit consists of a combination of non-volatile memory devices such as program ROM (Read Only Memory) and data ROM, and volatile memory devices such as RAM (Random Access Memory).

[0025] Next, the configuration of the belt conveying device 40 will be explained using Figure 2.

[0026] As shown in Figure 2, the belt conveying device 40 is positioned above the four image forming sections 20Y, 20C, 20M, and 20B. The belt conveying device 40 comprises an intermediate transfer belt 41, a drive roller 42, a tension roller 43, a pair of tension springs 44, and a pair of tension guide members 45.

[0027] The intermediate transfer belt 41 is an endless belt rotatably mounted on a plurality of rollers. In this embodiment, these rollers include a drive roller 42 and a tension roller 43. Above each of the four image forming sections 20Y, 20C, 20M, and 20B, a primary transfer roller 32r is positioned across the intermediate transfer belt 41. Each of the four primary transfer rollers 32r is positioned opposite the photoreceptor drum 21 across the intermediate transfer belt 41 and contacts the inner circumferential surface of the intermediate transfer belt 41.

[0028] The drive roller 42 is positioned downstream of the four image forming units 20Y, 20C, 20M, and 20B in the rotational direction of the intermediate transfer belt 41. The drive roller 42 receives power from a drive motor (not shown) and rotates the intermediate transfer belt 41 counterclockwise in Figure 2.

[0029] The drive roller 42 is positioned adjacent to the secondary transfer section 33. The secondary transfer roller 33r is positioned in the secondary transfer section 33. The secondary transfer roller 33r is positioned opposite the drive roller 42, with the intermediate transfer belt 41 in between, and contacts the outer circumferential surface of the intermediate transfer belt 41.

[0030] The tension roller 43 is positioned upstream of the four image forming sections 20Y, 20C, 20M, and 20B in the rotational direction of the intermediate transfer belt 41. The tension roller 43 rotates counterclockwise in Figure 2 in accordance with the rotation of the intermediate transfer belt 41. The tension roller 43 is biased by a pair of tension springs 44 in a direction away from the drive roller 42. This applies a predetermined tension to the intermediate transfer belt 41.

[0031] A pair of tension springs 44 are held within a pair of tension guide members 45. The pair of tension springs 44 are, for example, compression coil springs and are positioned between the pair of tension guide members 45 and the shaft portion 431 of the tension roller 43. The pair of tension springs 44 bias the tension roller 43 in a direction that moves it away from the drive roller 42.

[0032] Each of the pair of tension guide members 45 is positioned at both ends of the tension roller 43 in the axial direction (depth direction in Figure 2). Each of the pair of tension guide members 45 has a shaft portion 451 that extends parallel to the axial direction of the tension roller 43 and is positioned in a direction approaching the drive roller 42 relative to the tension roller 43. The pair of tension guide members 45 are supported by the main body 2 so as to be rotatable about the axis of the shaft portion 451.

[0033] The pair of tension guide members 45 are made of sheet metal, for example, and extend in a direction perpendicular to the axial direction of the tension roller 43, and in the vertical direction. The pair of tension guide members 45 support the shaft portion 431 of the tension roller 43 so that it can move toward and away from the drive roller 42. The pair of tension guide members 45 are biased by a pair of biasing members 55, which will be described later, located below the pair of tension guide members 45, so that the tension roller 43 side rotates downward about the axis of the shaft portion 451.

[0034] <First Embodiment> Next, the configuration around the tension roller 43 of the belt conveying device 40 of the first embodiment will be described using Figures 3, 4, and 5. Figure 3 is a side view of the belt conveying device 40 of the first embodiment. Figure 4 is a partial side view of the area around the tension roller 43 of the belt conveying device 40 of Figure 3. Figure 5 is a partial side view of the area around the tension roller 43 of Figure 4, showing the intermediate transfer belt 41 in a meandering state.

[0035] Figures 4 and 5 show the area around one end of the tension roller 43 in the axial direction Dx, viewed from the side perpendicular to the axial direction Dx of the tension roller 43. In Figures 4 and 5, the left side of the figure is the inside of the tension roller 43 in the axial direction Dx, and the right side of the figure is the outside of the tension roller 43 in the axial direction Dx. Also, for the sake of explanation, in Figure 3, the connecting member 53, which will be described later, is drawn with a dashed line to make the other components easier to see. In Figures 4 and 5, the drawing of the connecting member 53 is omitted. The same applies to Figures 6 and 7, which will be described later.

[0036] The belt conveying device 40 further includes a correction mechanism 50 as shown in Figures 3, 4, and 5. The correction mechanism 50 is positioned at both ends of the tension roller 43 in the axial direction Dx and on the underside of the tension roller 43. The correction mechanism 50 corrects the meandering of the intermediate transfer belt 41 relative to the tension roller 43. The correction mechanism 50 comprises a pair of belt guides 51, a pair of inclined bearings 52, a connecting member 53, a pair of main body guides 54, and a pair of biasing members 55.

[0037] A pair of belt guides 51 are positioned at each end of the tension roller 43 in the axial direction Dx. The pair of belt guides 51 are positioned inward of the pair of inclined bearings 52 and outward of the intermediate transfer belt 41 with respect to the axial direction Dx of the tension roller 43. The pair of belt guides 51 are movable in the axial direction Dx of the tension roller 43.

[0038] The pair of belt guides 51 are annular members that extend radially around the axis of the tension roller 43 and protrude radially outward from the outer surface of the intermediate transfer belt 41. The shaft portion 431 of the tension roller 43 passes through the radial center of the pair of belt guides 51 in the axial direction Dx. The pair of belt guides 51 face and contact the side edge 41e of the intermediate transfer belt 41 in the axial direction Dx of the tension roller 43.

[0039] The pair of inclined bearings 52 are positioned outside the axial direction Dx of the tension roller 43 compared to the pair of belt guides 51. The pair of inclined bearings 52 rotatably support the shaft portion 431 of the tension roller 43 around its axis. The pair of inclined bearings 52 are movable in the axial direction Dx of the tension roller 43.

[0040] The connecting member 53 is positioned to the side of the tension roller 43, radially outward from the tension roller 43, and spaced apart from the tension roller 43. The connecting member 53 is a plate-shaped member that extends in the vertical direction and along the axial direction Dx of the tension roller 43. The connecting member 53 connects to each of the pair of inclined bearings 52 at each end of the axial direction Dx of the tension roller 43. In other words, the connecting member 53 connects the pair of inclined bearings 52. As a result, the pair of inclined bearings 52 move in the same direction and at the same timing along the axial direction Dx of the tension roller 43.

[0041] Furthermore, each pair of inclined bearings 52 has a pair of inclined portions 521. Each of the pair of inclined portions 521 is positioned below each of the pair of inclined bearings 52. Moreover, each of the pair of inclined portions 521 is located below the tension roller 43 when viewed from the side perpendicular to the axial direction Dx of the tension roller 43. Each of the pair of inclined portions 521 faces each of the pair of body guides 54.

[0042] The outer surfaces of the pair of inclined portions 521 are inclined with respect to the axial direction Dx of the tension roller 43. More specifically, the inclined portions 521 have an inclination that moves from the inside outward (from left to right in Figures 4 and 5) in the axial direction Dx of the tension roller 43, and from the radial center side outward (from top to bottom in Figures 4 and 5). The inclination of each of the pair of inclined portions 521 is symmetrical with respect to the central part of the axial direction Dx of the tension roller 43.

[0043] The pair of main body guides 54 are positioned opposite the pair of inclined sections 521 and are fixed to the main body 2. The pair of main body guides 54 are composed of, for example, a pair of rod-shaped members and extend in a direction perpendicular to the axial direction Dx of the tension roller 43 (the depth direction of the paper in Figures 3, 4, and 5). In other words, the pair of main body guides 54 extend along the rotational direction of the intermediate transfer belt 41.

[0044] Each of the two main body guides 54 has a curved portion 54a that extends outward from the top in the axial direction Dx and faces the pair of inclined portions 521. The pair of main body guides 54 face and contact the pair of inclined portions 521 in the vertical direction and in the axial direction Dx. More specifically, the curved portion 54a of the main body guide 54 faces and contacts the slope of the inclined portion 521.

[0045] The pair of biasing members 55 are positioned below the pair of tension guide members 45. The pair of biasing members 55 are, for example, made up of tension coil springs and are connected between the main body 2 and the pair of tension guide members 45. The pair of biasing members 55 bias the shaft portion 431 of the tension roller 43 downwards via the pair of tension guide members 45. In other words, the pair of biasing members 55 bias the pair of inclined bearings 52 toward the pair of main body guides 54 and maintain contact between the pair of inclined bearings 52 and the pair of main body guides 54.

[0046] As shown in Figure 4, the shaft portion 431 of the tension roller 43 is biased downward by a pair of biasing members 55, causing the pair of inclined bearings 52 to be pressed against the pair of main body guides 54. When the intermediate transfer belt 41 is rotating normally and not meandering, the shaft portion 431 of the tension roller 43 is approximately horizontal. The state shown in Figure 4 is maintained while the intermediate transfer belt 41 is rotating normally.

[0047] As shown in Figure 5, when the intermediate transfer belt 41 meanders, it contacts one side of the belt guide 51 and pushes the belt guide 51 outward in the axial direction Dx (to the right in Figure 5). The belt guide 51 moves outward in the axial direction Dx. Then, the belt guide 51 pushes the inclined bearing 52 outward in the axial direction Dx (to the right in Figure 5). The inclined bearing 52 moves outward in the axial direction Dx.

[0048] As a result, the inclined bearing 52 slides on the main body guide 54 via the slope of the inclined portion 521, causing one end of the tension roller 43 in the axial direction Dx (right side in Figure 5) to move downward. In other words, the main body guide 54 moves one end of the tension roller 43 in the axial direction Dx in a direction perpendicular to the axial direction Dx, together with the pair of inclined bearings 52 that move in the axial direction Dx of the tension roller 43 as the intermediate transfer belt 41 meanders.

[0049] Then, the entire tension roller 43 tilts, and the meandering of the intermediate transfer belt 41 stops. As a result, the intermediate transfer belt 41 continues to rotate stably.

[0050] As described above, the pair of inclined sections 521 and the pair of main body guides 54 are positioned inward from the ends of the axial direction Dx of the tension roller 43 when viewed from a direction perpendicular to the axial direction Dx of the tension roller 43. With this configuration, the pair of inclined sections 521 and the pair of main body guides 54 of the correction mechanism 50 that inclins the tension roller 43 are not located outside the ends of the axial direction Dx of the tension roller 43. In other words, the belt conveying device 40 can be miniaturized in the axial direction Dx of the tension roller 43. Therefore, the belt conveying device 40 can stop the meandering of the intermediate transfer belt 41 with a miniaturized configuration.

[0051] More specifically, the pair of inclined sections 521 and the pair of main body guides 54 are positioned below the tension roller 43. This configuration allows the pair of inclined sections 521 and the pair of main body guides 54 to easily come into contact with the tension roller 43 by utilizing the effect of gravity. Therefore, the correction mechanism 50 can be made simpler, and the belt conveying device 40 can be made smaller.

[0052] Furthermore, the correction mechanism 50 is positioned near the tension roller 43 and comprises a pair of belt guides 51, a pair of inclined bearings 52, a pair of main body guides 54, and a pair of biasing members 55. Since tension is applied to the intermediate transfer belt 41 at the location of the tension roller 43, meandering of the intermediate transfer belt 41 is likely to occur. Therefore, by providing the correction mechanism 50, which is an alignment adjustment mechanism, with respect to the tension roller 43, it is possible to improve the performance in stopping meandering of the intermediate transfer belt 41.

[0053] <Second Embodiment> Next, the configuration around the tension roller 43 of the belt conveying device 40 of the second embodiment will be described with reference to Figure 6. Figure 6 is a partial side view of the area around the tension roller 43 of the belt conveying device 40 of the second embodiment of the present invention. Note that the basic configuration of the second embodiment is the same as that of the first embodiment described earlier, so common components may be given the same reference numerals or names as before and their descriptions may be omitted.

[0054] The belt conveying device 40 of the second embodiment includes a correction mechanism 50. The correction mechanism 50 is positioned at both ends of the tension roller 43 in the axial direction Dx and on the underside of the tension roller 43. The correction mechanism 50 includes a pair of belt guides 51, a pair of inclined bearings 52, a connecting member 53 (not shown in Figure 6), a pair of main body guides 56, and a pair of biasing members 55.

[0055] The pair of main body guides 56 extend in a direction perpendicular to the axial direction Dx of the tension roller 43 (the depth direction of the paper in Figure 6). In other words, the pair of main body guides 54 extend along the rotational direction of the intermediate transfer belt 41. The pair of main body guides 56 are composed of a pair of cylindrical members whose outer surfaces contact a pair of inclined portions 521.

[0056] According to the above configuration, a pair of main body guides 56 can be easily formed. Therefore, the correction mechanism 50 can be made into a simple configuration, and the belt conveying device 40 can be made smaller.

[0057] <Third Embodiment> Next, the configuration around the tension roller 43 of the belt conveying device 40 of the third embodiment will be described with reference to Figure 7. Figure 7 is a partial side view of the area around the tension roller 43 of the belt conveying device 40 of the third embodiment of the present invention. Note that the basic configuration of the third embodiment is the same as that of the first embodiment described earlier, so common components may be given the same reference numerals or names as before and their descriptions may be omitted.

[0058] The belt conveying device 40 of the third embodiment includes a correction mechanism 50. The correction mechanism 50 is positioned at both ends of the tension roller 43 in the axial direction Dx and on the underside of the tension roller 43. The correction mechanism 50 includes a pair of belt guides 51, a pair of inclined bearings 52, a connecting member 53 (not shown in Figure 7), a pair of main body guides 57, and a pair of biasing members 55.

[0059] The pair of main body guides 57 are composed of a pair of rotating bodies that rotate around the axis of a shaft portion 57a ​​that extends in a direction perpendicular to the axial direction Dx of the tension roller 43 (the depth direction of the paper in Figure 7). The pair of main body guides 57 rotate with their outer circumferential surfaces in contact with a pair of inclined portions 521.

[0060] With the above configuration, the contact state between the pair of inclined bearings 52 and the pair of main body guides 57 can be made rolling friction. Since rolling friction has a much smaller frictional force than sliding friction, it is possible to reduce the frictional load. By reducing the frictional load, wear of the pair of inclined bearings 52 and the pair of main body guides 57 can be suppressed, and the performance of stopping the meandering of the intermediate transfer belt 41 can be suitably maintained.

[0061] Although embodiments of the present invention have been described above, the scope of the present invention is not limited thereto, and various modifications can be made to implement the invention without departing from the spirit of the invention.

[0062] For example, in the above embodiment, the belt conveying device 40 is configured to include an intermediate transfer belt 41 on which toner images formed by the four image forming units 20 are sequentially transferred, but the present invention is not limited to such a device. The present invention can also be applied to a belt conveying device that includes a conveyor belt for conveying a recording medium on which images are recorded by the image forming units.

[0063] Furthermore, in the above embodiment, the image forming apparatus 1 is assumed to be a so-called tandem-type image forming apparatus for color printing, but it is not limited to this type. The image forming apparatus may be any other type of color printing apparatus that is not tandem-type, as long as it is equipped with an intermediate transfer belt. [Industrial applicability]

[0064] The present invention can be used in belt conveying devices and image forming devices. [Explanation of Symbols]

[0065] 1. Image forming apparatus 2 Main unit 20 Image forming unit 21 Photoconductor drum 30 Transfer section 40 Belt conveying device 41 Intermediate transfer belt (belt) 43 Tension roller (roller) 50 Correction mechanism 51 Belt Guide 52 Inclined bearings 53 Connecting member 54, 56, 57 Main unit guide 55 Biasing member 521 Slope Dx axial direction S Paper (recording medium)

Claims

1. An endless belt, Multiple rollers that rotatably mount the aforementioned belt, A correction mechanism for correcting the meandering of the belt relative to the roller, Equipped with, The correction mechanism is, A pair of inclined bearings have a pair of inclined portions that are inclined symmetrically with respect to the axial direction of the roller, and rotatably support the shaft portion of any of the rollers and are movable in the axial direction of the roller, A pair of main body guides that contact the pair of inclined portions and move one end of the roller in the axial direction in a direction perpendicular to the axial direction, together with the pair of inclined bearings that move in the axial direction of the roller as the belt meanders, Equipped with, The belt conveying device is characterized in that the pair of inclined portions are arranged to extend from the outside to the inside of both ends in the axial direction of the outer surface of the roller that the belt contacts, when viewed from a direction perpendicular to the axial direction of the roller.

2. The belt conveying device according to claim 1, characterized in that the pair of inclined portions and the pair of main body guides are arranged below the roller.

3. The belt conveying device according to claim 1, characterized in that the pair of main body guides are composed of a pair of cylindrical members that extend in a direction perpendicular to the axial direction of the roller and whose outer circumferential surfaces contact the pair of inclined portions.

4. The belt conveying device according to claim 1, characterized in that the pair of main body guides are composed of a pair of rotating bodies that rotate around an axis extending in a direction perpendicular to the axial direction of the roller while in contact with the pair of inclined portions.

5. The belt conveying device according to claim 1, characterized in that the correction mechanism comprises a pair of biasing members that bias the pair of inclined bearings toward the pair of main body guides and maintain contact between the pair of inclined bearings and the pair of main body guides.

6. Multiple image forming units, A belt conveying device according to claim 1, which is arranged adjacent to the image forming unit and conveys a recording medium on which an image is recorded by the image forming unit, An image forming apparatus equipped with the following features.

7. Multiple image forming units, A belt conveying device according to claim 1, wherein the belt is arranged adjacent to the image forming unit, and the belt is an intermediate transfer belt on which toner images formed in the image forming unit are sequentially superimposed and transferred, An image forming apparatus equipped with the following features.

Images