CN211149191U - Transfer device and image forming apparatus - Google Patents

Abstract

The utility model provides a transfer printing device and image forming device. The transfer device includes: an intermediate transfer belt formed as an endless belt, and an outer side surface carrying the toner image transferred to the sheet; a secondary transfer roller which is rotatably in contact with the intermediate transfer belt and transfers the toner image on the intermediate transfer belt to a sheet; an opposing roller located at a position opposing the secondary transfer roller across the intermediate transfer belt, the opposing roller and the secondary transfer roller having a predetermined nip amount formed therebetween for nipping and conveying the sheet; and a pitch adjusting portion provided between an axial end of the first shaft that supports the secondary transfer roller and an axial end of the second shaft that supports the counter roller, the pitch adjusting portion adjusting the biting amount so as to move in the sliding direction between the axial ends of the first shaft and the second shaft. Through the utility model discloses, can freely adjust the secondary transfer roller and the volume of stinging between the relative roller.

Description

Transfer device and image forming apparatus

Technical Field

Embodiments of the present invention relate to a transfer device and an image forming apparatus.

Background

Conventionally, an image forming apparatus is provided with a transfer device that transfers a toner image onto a sheet. In general, a transfer device includes a secondary transfer roller and an opposite roller opposed to the secondary transfer roller via an intermediate transfer belt, and after the secondary transfer roller and the opposite roller are positioned, a nip amount of a sheet to be nipped and conveyed is determined. When the nip amount is small, the conveyance of the sheet becomes unstable, but the image formation quality is good, and when the nip amount is large, the image blur is deteriorated, but the conveyance of the sheet becomes stable.

However, in the prior art, the biting amount formed between the secondary transfer roller and the opposing roller is fixed, the distance between the secondary transfer roller and the opposing roller cannot be changed according to the specific situation, and a choice cannot be made between facilitating the paper conveyance stability or suppressing the image blur according to the specific situation.

SUMMERY OF THE UTILITY MODEL

The utility model provides a make secondary transfer roller and the changeable transfer means of interval and image forming device between the relative roller.

A transfer device of an embodiment is provided in an image forming apparatus that transfers a toner image formed by an image forming unit onto a sheet, the transfer device including: an intermediate transfer belt formed as an endless belt, and an outer side surface carrying the toner image transferred to the sheet; a secondary transfer roller which is rotatably in contact with the intermediate transfer belt and transfers the toner image on the intermediate transfer belt to the sheet; an opposing roller located at a position opposing the secondary transfer roller across the intermediate transfer belt, the opposing roller and the secondary transfer roller having a predetermined nip amount formed therebetween for nipping and conveying the sheet; and a pitch adjusting portion provided between an axial end portion of a first shaft that supports the secondary transfer roller and an axial end portion of a second shaft that supports the opposite roller, the pitch adjusting portion adjusting the biting amount so as to move in a sliding direction between the axial end portion of the first shaft and the axial end portion of the second shaft.

An image forming apparatus according to another embodiment includes: an image reading section that reads an original document to generate image data of the original document; an image forming unit that forms a toner image based on the image data; a transfer device that transfers the toner image onto a sheet; a fixing section that fixes the toner image on the sheet; wherein, the transfer printing device includes: an intermediate transfer belt formed as an endless belt, and an outer side surface carrying the toner image transferred to the sheet; a secondary transfer roller which is rotatably in contact with the intermediate transfer belt and transfers the toner image on the intermediate transfer belt to the sheet; an opposing roller located at a position opposing the secondary transfer roller across the intermediate transfer belt, the opposing roller and the secondary transfer roller having a predetermined nip amount formed therebetween for nipping and conveying the sheet; and a pitch adjusting portion provided between an axial end portion of a first shaft that supports the secondary transfer roller and an axial end portion of a second shaft that supports the opposite roller, the pitch adjusting portion adjusting the biting amount so as to move in a sliding direction between the axial end portion of the first shaft and the axial end portion of the second shaft.

Through the utility model discloses, can freely adjust the secondary transfer roller and the volume of stinging between the relative roller.

Drawings

FIG. 1 is a schematic view of an image forming apparatus according to the present invention;

FIG. 2 is a partially enlarged schematic view of a transfer device according to the present invention;

fig. 3 is a schematic perspective view of the pitch adjustment part of the present invention;

fig. 4 is a schematic front view of the pitch adjustment unit of the present invention;

fig. 5 is a schematic plan view of the pitch adjustment unit of the present invention;

fig. 6 is a schematic front view of another embodiment of the pitch adjustment unit according to the present invention.

Detailed Description

Hereinafter, a transfer device and an image forming apparatus according to an embodiment will be described with reference to the drawings. In the drawings, the same components are denoted by the same reference numerals.

For convenience of explanation, coordinate axes are shown in the drawings. The X-axis direction is a horizontal direction of the image forming apparatus 1. The Y-axis direction is a vertical direction of the image forming apparatus 1. The Z-axis direction is a depth direction of the image forming apparatus 1. The direction in which the X-axis arrow faces is the right side of the image forming apparatus 1, the direction in which the Y-axis arrow faces is the upper side of the image forming apparatus 1, the direction in which the Z-axis arrow faces (i.e., the direction toward the back side in the drawing in fig. 1) is the rear side of the image forming apparatus 1, and the directions opposite to the right side, the upper side, and the rear side are the left side, the lower side, and the front side of the image forming apparatus 1. A broken line G in the drawing is defined as a conveyance path of a sheet (paper) P, a direction of an arrow V is a sheet conveyance direction, a paper feed cassette 18 side is an "upstream side", and a paper discharge section 22 side is a "downstream side". In the drawings, the structure is shown enlarged, reduced, or omitted as appropriate for convenience of explanation.

Fig. 1 is a schematic configuration diagram of an image forming apparatus 1 according to the present invention.

As shown in fig. 1, the image forming apparatus 1 of the present embodiment is, for example, a multifunction machine, a printer, a copier, or the like. The image forming apparatus 1 forms an image on a sheet based on image data read on an original. Next, a case where the image forming apparatus 1 is a multifunction peripheral will be described.

The image forming apparatus 1 has a main body 11. An image reading portion 12 is provided on an upper portion of the main body 11, and the image reading portion 12 is used to read an original to generate image data of the original. The image reading portion 12 is composed of a document conveying portion 13 and a scanner portion 14.

A scanner unit 14 is provided below the document conveying unit 13. The original conveying portion 13 conveys an original to be transferred to the scanner portion 14. The scanner portion 14 has an optical mechanism 15, and the scanner portion 14 reads the original to be transferred conveyed by the original conveying portion 13 or the original to be transferred placed directly on a platen glass of the scanner portion 14 through the optical mechanism 15.

The optical mechanism 15 moves in the left-right direction along the platen glass when reading an image of an original directly placed on the platen glass of the scanner unit 14. The optical mechanism 15 reads an original image on one original page line by line. When reading an image of a document conveyed by the document conveying portion 13, the optical mechanism 15 reads the conveyed document at a fixed position shown in fig. 1.

An operation display unit 16 is provided on the front side of the scanner unit 14 and above the main body 11. The operation display unit 16 has a function of receiving an operation by an operator and displaying a state of the image forming apparatus 1. The operation display unit 16 is, for example, a touch panel type liquid crystal display.

The main body 11 includes a plurality of paper feed cassettes 18 at a lower portion thereof for supplying sheets P to a transfer device 17 to be described later. The plurality of paper feed cassettes have substantially the same configuration and are arranged so as to overlap one another in order from the upper side toward the lower side.

The sheet feeding cassette 18 has a sheet feeding mechanism 19. The paper feed mechanism 19 takes out the sheets P one by one from the paper feed cassette 18 and conveys the sheets P to a conveyance path. For example, the paper feeding mechanism 19 may include a pickup roller, a separation roller, and a paper feeding roller. The paper feed cassette 18 accommodates sheets of various sizes.

The main body 11 has a plurality of image forming units 51 at the center in the height direction, which form toner images based on image data read by the image reading unit 12. Different image forming units 51 form images using different color toners (e.g., yellow, magenta, cyan, black, etc.). The structures of the respective image forming units 51 are the same as each other except that the colors of the toners are different.

An exposure unit 52 is provided below the image forming unit 51. The exposure device 52 converts image data read by the image reading unit 12 or image data introduced from an external device into color signals of the respective colors, and irradiates the respective image forming units 51 with exposure light in accordance with the color signals of the respective colors.

Above the image forming unit 51, there is a transfer device 17. The image forming units 51 are arranged in parallel below the transfer device 17 (in a direction from the left side to the right side in fig. 1). The transfer device 17 transfers the toner image formed by the image forming unit 51 onto the sheet P.

The transfer device 17 includes an intermediate transfer belt 53 that rotates along an arrow N, a plurality of primary transfer rollers 59, a plurality of driven rollers 70, a secondary transfer roller 71, and a counter roller 69 (as a driving roller that drives the intermediate transfer belt 53 to rotate). The intermediate transfer belt 53 is supported from the inside by a plurality of driven rollers 70 and counter rollers 69. The intermediate transfer belt 53 is in contact with each image forming unit 51 from above. The plurality of primary transfer rollers 59 primarily transfer the toner images formed on the image forming unit 51 onto the intermediate transfer belt 53 when a primary transfer voltage is applied thereto. After the toner images of the plurality of image forming units 51 are sequentially transferred onto the intermediate transfer belt 53 in such a manner as to overlap each other, toner images formed of the toners of the respective colors are formed. When the sheet P passes between the secondary transfer roller 71 and the counter roller 69, the intermediate transfer belt 53 is pressed against the sheet P by the secondary transfer roller 71, and the toner image primarily transferred onto the intermediate transfer belt 53 is secondarily transferred onto the sheet P after the secondary transfer voltage is applied to the secondary transfer roller 71.

A conveying roller pair 75 and a registration roller pair 76 are provided on a conveying path from the paper feed cassette 18 to the secondary transfer roller 71. The conveying roller pair 75 conveys the sheet P taken out of the sheet feeding cassette 18 by the sheet feeding mechanism 19.

The registration roller pair 76 aligns the position of the leading end of the sheet P fed from the conveying roller pair 75 at the mutual contact position. The mutually abutting positions of the pair of registration rollers 76 constitute registration positions. When the leading end of the toner image reaches the secondary transfer position (the position where the secondary transfer roller 71 abuts against the counter roller 69), the registration roller pair 76 conveys the sheet P so that the leading end of the region of the sheet P to which the toner image is to be transferred reaches the secondary transfer position.

The fixing unit 8 is disposed downstream (upper side in fig. 1) of the secondary transfer roller 71 in the conveying direction of the sheet P. The fixing section 8 heats and pressurizes the sheet P to fix the toner image on the sheet P.

A discharge roller pair 21 is disposed downstream (upper left side in fig. 1) of the fixing section 8 in the conveying direction of the sheet P. The discharge roller pair 21 discharges the sheet P to the sheet discharge portion 22.

A reverse conveyance path 10 is disposed downstream (right side in fig. 1) of the fixing section 8 in the conveyance direction of the sheet P. The reverse conveyance path 10 reverses the sheet P and guides the sheet P to the secondary transfer roller 71. The reverse conveyance path 10 is used when performing duplex printing.

Next, the transfer device 17 of the present invention will be specifically described with reference to fig. 1 and 2.

Fig. 2 is a partially enlarged schematic view of the transfer device 17 of the present invention. The relationship between the secondary transfer roller 71 and the opposing roller 69 is mainly illustrated in fig. 2 for clarity, and therefore only a right portion of the transfer device 17 is partially illustrated.

As shown in fig. 1, the intermediate transfer belt 53 of the transfer device 17 is formed as an endless circulating belt, and is supported from the inside by a plurality of driven rollers 70 and counter rollers 69, the intermediate transfer belt 53 is rotatable along an endless path, and the outer side surface below the intermediate transfer belt 53 is in contact with each image forming unit 51. Each of the primary transfer rollers 59 is disposed opposite to the image forming unit 51 across the intermediate transfer belt 53, and a primary voltage is applied to the primary transfer roller 59 to transfer the toner image formed on the image forming unit 51 onto the intermediate transfer belt 53, whereby the toner image transferred to the sheet P is carried on the outer side surface of the intermediate transfer belt 53. The counter roller 69 is connected to a drive motor, not shown, provided in the image forming apparatus 1. The counter roller 69 is rotatable about its axis by a driving force transmitted from a driving motor, and rotates the transfer belt 53. The counter roller 69, the driven roller 70, and the primary transfer roller 59 are disposed inside the endless intermediate transfer belt 53.

As shown in fig. 2, the secondary transfer roller 71 is located at a position opposing the opposing roller 69 across the intermediate transfer belt 53, and the intermediate transfer belt 53 is sandwiched between the opposing roller 69 and the secondary transfer roller 71. The secondary transfer roller 71 is rotatably in contact with the outer side surface of the intermediate transfer belt 53. The counter roller 69 is rotatably in contact with the inner side surface of the intermediate transfer belt 53. The secondary transfer roller 71 is supported by the first shaft 71a, and the counter roller 69 is supported by the second shaft 69 a.

The biting amount F formed by pressing between the secondary transfer roller 71 and the counter roller 69 and the shaft distance L between the first shaft 71a and the second shaft 69a will be described below.

As shown in fig. 2, the axial end of the second shaft 69a supporting the counter roller 69 is fixed in abutment with the guide rail of the intermediate transfer belt 53 in the transfer device 17, and the second shaft 69a is thereby positioned. The secondary transfer roller 71 is movably supported by the first shaft 71a so as to be movable toward the opposite roller 69 or away from the opposite roller 69.

The transfer device 17 includes an urging member 72. The axial end of the first shaft 71a supporting the secondary transfer roller 71 is connected to one end of the urging member 72, and the urging member 72 may be, for example, a member such as a spring or a pressure lever having one end connected to the first shaft 71a and the other end connected to the frame of the transfer device 17. An axial end portion of the first shaft 71a is pressed toward the opposing roller 69 in the direction of arrow D via the urging member 72. When the axial end of the first shaft 71a supporting the secondary transfer roller 71 is pressed by the urging member 72 into abutment with the guide rail of the intermediate transfer belt 53 in the transfer device 17, the first shaft 71a is positioned.

After positioning, the linear distance between the axis of the first shaft 71a and the axis of the second shaft 69a is the shaft distance L, and when the axial end of the first shaft 71a and the axial end of the second shaft 69a do not move, the shaft distance L remains unchanged.

Since the secondary transfer roller 71 is supported by the first shaft 71a, when the first shaft 71a is urged to move by the urging member 72, the secondary transfer roller 71 moves together, that is, the secondary transfer roller 71 is urged toward the opposing roller 69 by the urging member 72. At this time, the outer peripheral surface of the counter roller 69 and the outer peripheral surface of the secondary transfer roller 71 are pressed against each other to form a nip portion for nipping and conveying the sheet P, and the distance between the counter roller 69 and the secondary transfer roller 71 deformed by the pressing is the nip amount F. That is, the secondary transfer roller 71 moves toward the opposite roller 69 to form a certain nip amount F that nips and conveys the sheet P between the secondary transfer roller 71 and the opposite roller 69.

The size of the biting amount F of the secondary transfer roller 71 and the opposite roller 69 is in inverse proportion to the shaft interval L between the first shaft 71a and the second shaft 69a, i.e., when the shaft interval L increases, the distance between the secondary transfer roller 71 and the opposite roller 69 becomes longer, and therefore the biting amount F decreases, whereas when the shaft interval L decreases, the biting amount F increases.

When the shaft distance L between the counter roller 69 and the secondary transfer roller 71 is set to be small, that is, the nip amount F is large, the surface pressure between both rollers becomes large, and at this time, pressure loss hardly occurs in the direction along the axial direction of the first shaft 71a and the second shaft 69a, and therefore, the conveyance of the sheet P when passing through the nip portion is stable (inclination hardly occurs in the direction perpendicular to the conveyance direction), but the impact of the sheet P when hitting the nip portion is easily transmitted to the first shaft 71a and the second shaft 69a, and the speed of the intermediate transfer belt 53 is changed, and the toner image formed on the sheet P becomes blurred.

Therefore, regardless of how the value of the biting amount F is set, if the biting amount F is a fixed value, one of the passage stability of the sheet P and the image formation quality is improved, the other is deteriorated.

Next, the pitch adjusting section 3, which is provided in the transfer device 17 of the present invention and which can adjust the nip amount F between the secondary transfer roller 71 and the counter roller 69, will be described with reference to fig. 3, 4, and 5.

Fig. 3 is a schematic perspective view of the pitch adjustment unit 3 according to the present invention.

Fig. 4 is a schematic front view of the pitch adjustment unit 3 according to the present invention.

Fig. 5 is a schematic plan view of the pitch adjustment unit 3 according to the present invention.

As shown in fig. 3 to 5, the pitch adjustment portion 3 is provided between an axial end portion of the first shaft 71a that supports the secondary transfer roller 71 and an axial end portion of the second shaft 69a that supports the opposite roller 69. At this time, the secondary transfer roller 71 is positioned by the pitch adjusting section 3.

As shown in fig. 3, the pitch adjustment section 3 has a wedge section 31 as an embodiment. The wedge 31 has a first surface 33 and a second surface 34 opposed to the first surface 33, the first surface 33 is in contact with an axial end of the second shaft 69a as a positioning surface of the pitch adjusting section 3, the second surface 34 is in contact with an axial end of the first shaft 71a as a positioning surface of the secondary transfer roller 71, and the second surface 34 is formed to be inclined with respect to the first surface 33, that is, the second surface 34 has a certain inclination angle with respect to the first surface 33.

As shown in fig. 4, the second surface 34 is formed so as to be closer to the first surface 33 in the sliding direction E, and when the pitch adjustment portion 3 is slid in the sliding direction E between the axial end portion of the first shaft 71a and the axial end portion of the second shaft 69a, the distance between the portion where the second surface 34 and the first shaft 71a are in contact and the portion where the first surface 33 and the second shaft 69a are in contact gradually increases due to the formation of the second surface 34 being inclined with respect to the first surface 33, and the pitch adjustment portion 3 pushes the first shaft 71a in the direction away from the second shaft 69a against the elastic force of the urging member 72 on the first shaft 71a, so that the shaft pitch L between the first shaft 71a and the second shaft 69a increases, and at this time, the distance between the secondary transfer roller 71 and the counter roller 69 becomes longer, and the force of mutual pressing decreases, that is, i.e., the biting amount F between the secondary transfer roller 71 and the counter roller 69 decreases.

When the pitch adjustment portion 3 is moved in the direction opposite to the sliding direction E at the axial end portion of the first shaft 71a and the axial end portion of the second shaft 69a, the shaft pitch L is decreased and the biting amount F is increased, which is just the opposite of the above case.

Further, regardless of whether the pitch adjustment portion 3 is moved, the biasing member 72 biases the first shaft 71a in the direction of the second shaft 69a, so that the second surface 34 of the pitch adjustment portion 3 is always in contact with the axial end of the first shaft 71a, and the first surface 33 is always in contact with the axial end of the second shaft 69 a.

Thus, the pitch adjustment portion 3 adjusts the biting amount F so as to move in the sliding direction E between the axial end portion of the first shaft 71a and the axial end portion of the second shaft 69 a. The distance between the rollers is reduced to increase the biting amount, so that the sheet is stably conveyed. By increasing the distance between the rollers, the biting amount is reduced, and deterioration of the image blur is suppressed.

Further, since the pitch adjustment portion 3 needs to be operated, the pitch adjustment portion 3 is further provided with an operation knob 32, the operation knob 32 is formed on a surface connecting the first surface 33 and the second surface 34, and the shape of the operation knob 32 is not particularly limited, and may be formed as a rectangular block with rounded peripheries, for example. By moving the operation knob 32, the position of the pitch adjustment portion 3 between the axial end portion of the first shaft 71a and the axial end portion of the second shaft 69a can be easily adjusted.

Further, the position of the pitch adjusting section 3 may be controlled by the operation display section 16 according to a preset program at the time when the operating knob 32 is moved by the driving force of the motor by abutting the lower side or the upper side of the operating knob 32 with a cam mechanism, a link mechanism, or the like connected to the motor.

With the above embodiment, by providing the spacing adjustment portion 3 between the axial end portion of the first shaft 71a and the axial end portion of the second shaft 69a, the nip amount F between the secondary transfer roller 71 and the opposing roller 69 can be adjusted on a case-by-case basis, allowing the operator to select between facilitating stable conveyance of the sheet or suppressing image blurring.

Further, as shown in fig. 5, it is preferable that the distance adjusting portions 3 are provided between the axial end portions of the first shaft 71a and the second shaft 69a in the front-rear direction (Z-axis direction), respectively, so that when the axial dimension of the counter roller 69 and the secondary transfer roller 71 is large, the adjustment of the distance adjusting portions 3 to the shaft L, that is, the adjustment of the biting amount F in the axial direction is more balanced, thereby avoiding the occurrence of the imbalance of the shaft distance L, that is, the biting amount F at both ends in the axial direction.

Hereinafter, a configuration of a pitch adjustment unit according to another embodiment of the present invention will be described with reference to fig. 6.

Fig. 6 is a schematic front view of another embodiment of the pitch adjustment unit according to the present invention.

As shown in fig. 6, the pitch adjustment portion 3 'is composed of a step portion 31' and the operation knob 32, the step portion 31 'has a first surface 33' and a second surface 34 'opposite to the first surface 33', the first surface 33 'is in contact with an axial end of the second shaft 69a as a positioning surface of the pitch adjustment portion 3', the second surface 34 'is in contact with an axial end of the first shaft 71a as a positioning surface of the secondary transfer roller 71, and the second surface 34' is formed in a step shape having a plurality of steps. The plurality of level differences of the second surface 34 'are formed so as to be closer to the first surface 33' along the sliding direction E.

When the distance adjusting portion 3 ' is slid in the sliding direction E between the axial end portion of the first shaft 71a and the axial end portion of the second shaft 69a, since the second surface 34 ' has a step difference, the distance between the portion where the second surface 34 ' and the first shaft 71a are in contact and the portion where the first surface 33 ' and the second shaft 69a are in contact becomes larger in a step difference manner, and the distance adjusting portion 3 ' pushes the first shaft 71a in a direction away from the second shaft 69a against the elastic force of the urging member 72 on the first shaft 71a, so that the shaft distance L between the first shaft 71a and the second shaft 69a increases.

Thus, the pitch adjustment portion 3' adjusts the biting amount F so as to move in the sliding direction E between the axial end portion of the first shaft 71a and the axial end portion of the second shaft 69 a.

The operation knob 32 described above is also formed on the surface connecting the first surface 33 'and the second surface 34'.

In addition, in order to avoid the case where the secondary transfer roller 71 and the counter roller 69 are no longer in contact with each other (i.e., are separated) due to the excessively large adjustment of the shaft pitch L, i.e., the case where the biting amount F is excessively small, the minimum value of the biting amount F needs to be set to 0mm (this value is a case where a tolerance of ± 0.1mm is considered), and in order to avoid the case where the shaft pitch L is excessively small, i.e., the case where the biting amount F is excessively large and the sheet P is not allowed to pass smoothly due to excessive resistance, the maximum value of the biting amount F needs to be set to 0.4mm (this value is a case where a tolerance of ± 0.1mm is considered).

By appropriately setting the angle of the inclined second surface 34 of the pitch adjustment portion 3 or the step of the stepped second surface 34 'of the pitch adjustment portion 3', the biting amount F between the outer peripheral surface of the secondary transfer roller 71 and the outer peripheral surface of the counter roller 69 can be kept between 0mm and 0.4mm, and it is possible to avoid the biting amount F from being excessively large or small.

According to at least one embodiment described above, the distance adjusting portion is provided between the axial end portion of the first shaft and the axial end portion of the second shaft, so that the amount of biting between the secondary transfer roller and the opposed roller can be adjusted on a case-by-case basis, allowing the operator to select between facilitating stable conveyance of the sheet or suppressing image blurring.

While several embodiments of the present invention have been described, these embodiments have been presented by way of example only, and are not intended to limit the scope of the invention. These new embodiments can be implemented in other various manners, and various omissions, substitutions, combinations, and changes can be made without departing from the gist of the present invention. These embodiments and modifications are included in the scope and gist of the present invention, and are included in the present invention described in the claims and the equivalent scope thereof.

Claims (10)

1. A transfer device provided in an image forming apparatus for transferring a toner image formed by an image forming unit onto a sheet, the transfer device comprising:

an intermediate transfer belt formed as an endless belt, and an outer side surface carrying the toner image transferred to the sheet;

a secondary transfer roller which is rotatably in contact with the intermediate transfer belt and transfers the toner image on the intermediate transfer belt to the sheet;

an opposing roller located at a position opposing the secondary transfer roller across the intermediate transfer belt, the opposing roller and the secondary transfer roller having a predetermined nip amount formed therebetween for nipping and conveying the sheet; and

and a pitch adjusting portion provided between an axial end portion of a first shaft that supports the secondary transfer roller and an axial end portion of a second shaft that supports the opposite roller, the pitch adjusting portion adjusting the biting amount so as to move in a sliding direction between the axial end portion of the first shaft and the axial end portion of the second shaft.

2. The transfer device according to claim 1,

the adjustment range of the biting amount is between 0mm and 0.4 mm.

3. The transfer device according to claim 2,

the distance adjustment portion has a wedge portion having a first surface that contacts an axial end portion of the second shaft and a second surface that contacts an axial end portion of the first shaft and is inclined with respect to the first surface.

4. The transfer device according to claim 2,

the distance adjustment portion has a stepped portion having a first surface that contacts an axial end portion of the second shaft and a second surface that is formed in a stepped shape that contacts an axial end portion of the first shaft.

5. The transfer device according to claim 2,

the distance adjusting portion has an operation handle, and the position of the distance adjusting portion is adjusted by moving the operation handle.

6. An image forming apparatus, comprising:

an image reading section that reads an original document to generate image data of the original document;

an image forming unit that forms a toner image based on the image data;

a transfer device that transfers the toner image onto a sheet; and

a fixing section that fixes the toner image on the sheet;

wherein, the transfer printing device includes:

an intermediate transfer belt formed as an endless belt, and an outer side surface carrying the toner image transferred to the sheet;

a secondary transfer roller which is rotatably in contact with the intermediate transfer belt and transfers the toner image on the intermediate transfer belt to the sheet;

an opposing roller located at a position opposing the secondary transfer roller across the intermediate transfer belt, the opposing roller and the secondary transfer roller having a predetermined nip amount formed therebetween for nipping and conveying the sheet; and

and a pitch adjusting portion provided between an axial end portion of a first shaft that supports the secondary transfer roller and an axial end portion of a second shaft that supports the opposite roller, the pitch adjusting portion adjusting the biting amount so as to move in a sliding direction between the axial end portion of the first shaft and the axial end portion of the second shaft.

7. The image forming apparatus according to claim 6,

the adjustment range of the biting amount is between 0mm and 0.4 mm.

8. The image forming apparatus according to claim 7,

the distance adjustment portion has a wedge portion having a first surface that contacts an axial end portion of the second shaft and a second surface that contacts an axial end portion of the first shaft and is inclined with respect to the first surface.

9. The image forming apparatus according to claim 7,

the distance adjustment portion has a stepped portion having a first surface that contacts an axial end portion of the second shaft and a second surface that is formed in a stepped shape that contacts an axial end portion of the first shaft.

10. The image forming apparatus according to claim 7,

the distance adjusting portion has an operation handle, and the position of the distance adjusting portion is adjusted by moving the operation handle.

Images