JPH1063139A - Image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image forming device capable of realizing simplification of the laying structure of a belt-like image carrier used for electrophotography and a high speed output. SOLUTION: A photoreceptor 1 being the belt-like image carrier is stretched and driven by plural rollers 2, 3, 4 and 5, and movably supported by a guiding groove 15 formed in parallel with the flat part 1a of the photoreceptor 1 stretched on a tension roller 3. A transfer roller 10 being an image forming auxiliary means is energized from a direction at an almost right angle to the groove 15, so that the roller 10 abuts on the roller 3 through the photoreceptor 1.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a belt-shaped photoreceptor,
Alternatively, a belt-shaped intermediate transfer member used in a color image forming apparatus, or a belt-shaped image carrier such as a recording sheet transport belt used in a tandem-type color image forming apparatus, and a developing unit that contacts the image carrier The present invention relates to an image forming apparatus having an image forming auxiliary unit such as a transfer unit or a cleaning unit.

[0002] More specifically, the present invention relates to a stretched structure of the image carrier and a contact structure of the image forming auxiliary means to the image carrier.

[0003]

2. Description of the Related Art There are various image forming apparatuses having a structure in which a belt-shaped image carrier is wrapped around a plurality of rollers, and the above-described image forming auxiliary means is brought into contact with the rollers via the image carrier. Has been proposed.

For example, as a first prior art, Japanese Patent Publication No.
In Japanese Patent No. 32072, a belt-shaped photosensitive member is wound around a driving roller and a driven roller, an elastic layer such as rubber is formed on the surface of one of the rollers, and a photosensitive member positioned on a roller having this elastic layer is formed. There has been proposed an apparatus that removes unnecessary toner by bringing a toner removing blade into contact with the blade.

A second prior art is disclosed in
Japanese Patent Publication No. 137167 discloses a belt-shaped photosensitive member wound around a plurality of rollers, and a transfer roller for transferring a toner image to a recording sheet is biased by a solenoid or the like to a roller that stretches the photosensitive member. A contact structure has been proposed.

A third prior art is disclosed in
In Japanese Patent Application Laid-Open No. 292156/1990, in a color image forming apparatus having a belt-shaped intermediate transfer member, unnecessary toner is brought into contact by contacting a detachable toner removing blade to a roller portion of the intermediate transfer member wound around a plurality of rollers. There has been proposed an apparatus for removing odor.

[0007]

In an image forming apparatus having a structure in which an image carrier such as a belt-shaped photosensitive member or an intermediate transfer member is wound around a plurality of rollers as in the above-mentioned prior art, the number of rollers is reduced. It is extremely important to minimize the structure in order to simplify the structure.

However, each roller transmits a driving force to the image carrier, applies a tension to the image carrier, and stabilizes the contact of image forming auxiliary means such as developing means, transfer means, and cleaning means in contact with the image carrier. It is required to perform various functions such as maintaining the tension of the image carrier corresponding to the separating / contacting operation of the image forming auxiliary means. To reduce the number of rollers, it is necessary to combine the functions performed by the individual rollers. Is required.

[0009] Reducing the number of rollers and combining these functions often results in opposing actions. For example, when a tension roller that applies tension to the image carrier and a backup roller that supports the contact force of the image forming auxiliary unit with the image carrier as described above are shared, the tension roller is previously stretched with a predetermined tension. When the image forming auxiliary means is brought into contact with the image carrier, the tension is reduced, and the image carrier may not be driven stably at a desired speed.

Such a problem is more serious when the transfer roller or the toner removing blade, which is an image forming assisting means, comes into contact with and separates from each other as in the second and third prior arts described above. When these image forming assisting units move away from each other, the tension of the image carrier fluctuates, and the image is locally expanded and contracted by the expansion and contraction of the image carrier and the fluctuation of the driving force.

In some cases, such local image expansion and contraction caused by the separation and contact of the image forming auxiliary means can be avoided by performing the separation and contact operation at a timing when the image forming apparatus does not perform continuous image formation. In addition, since continuous image formation cannot be performed, the number of prints per unit time of the image forming apparatus decreases.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problem, and has a simple structure, in which a tension roller of an image carrier and a backup roller for supporting the abutting force of an image forming assisting means on the image carrier are used in common. It is a first object of the present invention to provide a compact and small-sized image forming apparatus. In addition, even when the image forming assisting means involves a separating / contacting operation with respect to the image carrier, the fluctuation of the tension of the image carrier is extremely small and continuous. A second object is to provide a high-speed image forming apparatus capable of forming an image.

[0013]

According to a first aspect of the present invention, there is provided an image forming apparatus, comprising: a belt-shaped image carrier for carrying a toner image; An image forming apparatus having a plurality of rollers that are wound around the image carrier and an image forming auxiliary unit that comes into contact with the rollers via the image carrier, a tension roller that applies tension to at least one of the rollers to the image carrier The tension roller is movably supported by a guide groove provided in a direction substantially parallel to the flat portion of the image carrier wound around the roller, and biases the tension roller along the direction of the guide groove. By doing so, the image carrier is stretched, and the image forming auxiliary unit is urged from a direction substantially perpendicular to the guide groove, so that the image forming auxiliary unit comes into contact with the tension roller via the image carrier. And wherein the door.

According to a second aspect of the present invention, in the image forming apparatus, the image bearing member is a belt-shaped photosensitive member, and the image forming auxiliary means is a charging means, a developing means, or a photosensitive member. It is a transfer means for transferring a toner image to another medium, or a cleaning means for cleaning the photosensitive member.

According to a third aspect of the present invention, there is provided an image forming apparatus wherein the image carrier carries a toner image formed on a single photosensitive member by a plurality of developing means, and then collectively transfers the toner images onto a recording sheet. Wherein the image forming auxiliary means is a transfer means for transferring a toner image from the intermediate transfer body to a recording sheet, or a cleaning means for the intermediate transfer body.

Further, the image forming apparatus according to claim 4 is
A recording sheet transport belt that transports the recording sheet in opposition to the plurality of photoconductors in which the image carrier is arranged in parallel,
Further, the image forming assisting means is a cleaning means for the recording sheet conveying belt.

[0017]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail based on embodiments.

FIG. 1 is a sectional view of an image forming apparatus according to a first embodiment of the present invention. The schematic operation of the first embodiment will be described with reference to FIG.

In FIG. 1, a photosensitive member 1, which is a belt-shaped image carrier, is rotatably stretched and supported by a developing roller 2, a tension roller 3, a cleaning roller 4, and an exposing roller 5. Alternatively, it is driven in the direction of arrow A by the cleaning unit roller 4. The photoreceptor 1 is provided with a charging unit 6 which is in contact with the photoreceptor 1 constituted by a charging roller.
The electrostatic latent image is recorded by an exposure unit 7 including a laser scanning optical system or the like, and the electrostatic latent image is developed by a developing unit 8 having a non-magnetic one-component toner. It is visualized as a toner image. The toner image is urged by a transfer spring 9 and is transferred to a recording sheet 11 fed from a paper feeding unit (not shown) by a transfer unit 10 including a transfer roller that comes into contact with the photoconductor 1. The recording sheet 11 to which the toner image has been transferred is conveyed while being heated and pressurized by the fixing unit 12 and is carried out of the apparatus.

On the other hand, the photosensitive member 1 on which the toner image has been transferred to the recording sheet 11 is brought into contact with the cleaning means 13 composed of a rubber blade or the like, and unnecessary toner remaining on the surface is scraped off.

In this embodiment, the exposure unit roller 5 is disposed at a position facing the exposure unit 7 of the photoconductor 1 to back up the photoconductor 1 in the exposure unit. Although wrinkles and vibrations occurring in the depth direction of the paper near the portion 7a are prevented, when the photosensitive member 1 has sufficient rigidity, it is possible to simplify the stretching structure of the photosensitive member 1 according to the gist of the present invention. Can be omitted.

For the same reason, the charging means 6 and the cleaning means 13 are brought into contact with the cleaning roller 4 via the photoreceptor 1, but individual rollers are arranged opposite to the respective means. You may.

Here, the stretched structure of the photosensitive member 1 as the image carrier in this embodiment and the contact structure of the transfer unit 10 as the image forming auxiliary unit in this embodiment will be described.

In FIG. 1, the developing unit roller 2, the cleaning unit roller 4, and the exposing unit roller 5 are rotatably held on a side plate 14 with their axial positions fixed. On the other hand, the tension roller 3 is supported so that its axial position is movable along a guide groove 15 provided on the side plate 14 substantially in parallel with the flat portion 1a of the photoconductor 1 on which the tension roller 3 is stretched. Is urged in the direction of arrow B parallel to
Tension is applied to

On the other hand, the transfer means 10 includes a transfer spring 9
, And is in contact with the tension roller 3 via the photoreceptor 1 so that the angle between the arrow B and the arrow C is substantially a right angle.

That is, the contact force of the transfer means 10 is
, The tension of the photoconductor 1 is hardly affected by the contact force of the transfer means 10. For example, when the photoconductor 1 as a consumable part is replaced in a unit state in which the photoconductor 1 is stretched over each roller. The replaced photoconductor 1 is transferred to the transfer unit 10.
Does not change the stretched state of the photoconductor 1.

In this embodiment, the transfer means 10 is in contact with the tension roller 3 for stretching the photosensitive member 1 via the photosensitive member 1. However, the arrangement of the roller for stretching the photosensitive member 1 is changed. Then, the charging unit 6 or the developing unit 8 or the developing unit 8 is applied to a tension roller that is urged substantially in parallel with the flat portion of the photoconductor 1 wrapped around the roller group in the same configuration as the present example.
The same effect can be obtained even when the cleaning means 13 is configured to contact the tension roller 3 via the photoreceptor 1 from a direction substantially perpendicular to the biasing direction of the tension roller.

In this embodiment, the longitudinal direction of the guide groove 15 (the direction of arrow B) and the biasing direction of the transfer means 10 indicated by the arrow C are substantially perpendicular to each other, but are not necessarily limited to a right angle. However, the guide groove 15 may be changed depending on the direction in which the recording sheet 11 enters the transfer section, the arrangement of the fixing means 12, and the like.
May be deviated from a right angle by about 10 ° from the longitudinal direction (the direction of arrow B).

Next, a second embodiment of the image forming apparatus of the present invention will be described with reference to FIGS.

FIG. 2 is a sectional view of an image forming apparatus according to a second embodiment of the present invention, which is a color image forming apparatus using a belt-shaped intermediate transfer member.

In FIG. 2, a charging roller 18 serving as a charging means is disposed on the outer periphery of the photosensitive member 17 rotating in the direction of arrow D, and the surface of the photosensitive member 17 is uniformly charged while rotating in contact with the photosensitive member 17. Is done.

The photoreceptor 17 having a uniformly charged surface is selectively scanned and exposed as a first color according to, for example, yellow image information by a laser scanning optical system 19 as an exposing means. A latent image is formed.

On the downstream side in the rotation direction of the photosensitive member 17 on which the electrostatic latent image is recorded, yellow, magenta, cyan, and black toners are stored as developing agents, respectively. Means 20, 21, 22, and 23 are arranged, and the formed yellow electrostatic latent image is developed by contacting only the yellow developing means 20 with the photoconductor 17 to form a yellow toner image.

On the downstream side of the developing means in the direction of rotation of the photoconductor, a belt-shaped intermediate transfer member 24 is wound around an intermediate transfer member driving roller 25, a backup roller 26, a tension roller 27, and an auxiliary roller 28 adjacent to the photoconductor 17. Has been turned,
The photosensitive member 17 is driven at the same speed as the peripheral speed of the photosensitive member 17 by a drive source (not shown). Further, the intermediate transfer member 24 is the photosensitive member 1
7 and the primary transfer roller 29, and a voltage is supplied from a high-voltage power supply (not shown) to the primary transfer roller 29, whereby the yellow toner image formed in the above-described procedure is transferred to the surface of the intermediate transfer body 24. You.

The photoreceptor 17 having transferred the yellow toner image to the intermediate transfer member 24 further rotates in the direction of arrow D, and the toner remaining on the surface of the photoreceptor 17 is scraped by a photoreceptor cleaner 30 including a cleaner blade or the like. And the image can be formed again.

By repeating the same procedure for the second to fourth color images (magenta, cyan, and black), toner images of four colors are sequentially superimposed and recorded on the intermediate transfer member 24.

When the superposition of the four color toner images on the intermediate transfer member 24 is completed, the paper feed roller 31 and the paper transport roller pair 3
The recording sheet 34 is fed by 2 and 33, and in synchronization with this, the secondary transfer roller 35 is rotated in the direction of arrow E about the secondary transfer fulcrum shaft 36 by a clutch mechanism and a cam mechanism (not shown), and the intermediate transfer member is rotated. The intermediate transfer body 2 is brought into contact with the backup roller 26 via the second transfer roller 24, and a voltage is applied to the secondary transfer roller 35 from a high-voltage power supply (not shown).
The four color toner images on the fourth sheet 4 are transferred to the recording sheet 34.
The intermediate transfer body cleaner 37 composed of a cleaner blade or the like is rotated by a clutch mechanism and a cam mechanism (not shown) in the direction of arrow F to come into contact with the intermediate transfer body 24 after the secondary transfer, and the surface of the intermediate transfer body 24. When the scraping is completed, the transfer body cleaner 37 rotates in the direction opposite to the arrow F and retracts.

Recording sheet 3 on which four color toner images have been transferred
Reference numeral 4 denotes a fixing unit 38 having a heat roller having a built-in heating unit such as a halogen lamp. The recording sheet 34 on which the toner image has been fixed is discharged to the outside of the apparatus by the discharge roller pairs 39 and 40, and the color image recording is completed.

Here, FIG. 3 shows a stretched structure of the intermediate transfer member 24 which is an image carrier in this embodiment and a contact structure of an intermediate transfer member cleaner 37 which is an image forming auxiliary means in this embodiment.
This will be described with reference to FIG.

FIG. 3 is a partial sectional view showing a stretched structure of the intermediate transfer member 24 according to the second embodiment of the present invention. In FIG. 3, a backup roller 26, an intermediate transfer member driving roller 25 and an auxiliary roller 28 not shown in FIG.
1 and is rotatably held at a fixed axial position. On the other hand, the tension roller 27 is
An axial position is supported movably along a guide groove 42 provided in the side plate 41 substantially in parallel with the flat portion 24 a of the side plate 24 a, and a pressure lever 44 and a tension spring 45 rotatable around a pressure fulcrum shaft 43. The tension is applied to the intermediate transfer body 24 by being urged in the direction of arrow G parallel to the guide groove 42. This tension structure is provided on both side surfaces of the intermediate transfer body 24. The tension spring 45 is applied to one of a plurality of tension spring hooks 44a provided on the pressing lever 44 on each side surface, so that the intermediate transfer body 24 is The structure is such that the absolute value and balance of the applied tension can be adjusted.
4 meandering during driving is prevented.

FIG. 4 is a partial sectional view showing the contact structure of the intermediate transfer member cleaner 37 in the second embodiment of the present invention. 4, when the cleaner cam 46 is rotated by a clutch mechanism (not shown), the intermediate transfer member cleaner is rotated in the direction of arrow F by the urging force of the cleaner spring 47, and the cleaner blade is urged in the direction of arrow H while the intermediate transfer member 24 is urged. Abuts on the tension roller 27 via At this time, the direction of the arrow H is substantially perpendicular to the direction of the arrow G that is the urging direction of the intermediate transfer body 24 of the tension roller 27 described above. The intermediate transfer member cleaner 3
The rotation center of the separating / contacting operation of the intermediate transfer member 7 is the same as the rotation center of the discharge screw 48 that conveys the waste toner collected inside the intermediate transfer member cleaner 37 in the depth direction of the paper while rotating. The movement of the coupling member 37 between the transfer body cleaner 37 and the waste toner bottle (not shown) in which the waste toner is collected is a simple rotational movement due to the swinging operation of the separation / contact swing operation of the waste toner 37, so that the waste toner leakage prevention structure can be simplified. it can.

As can be seen from the description of FIGS. 3 and 4, the longitudinal direction (direction of arrow H) of the guide groove for supporting the tension roller 27 is substantially perpendicular to the tension biasing direction G of the intermediate transfer member. Since most of the contact force of the intermediate transfer member cleaner 37 is supported by the guide groove 42, the tension of the intermediate transfer member 24 is hardly affected by the separation / contact operation of the intermediate transfer member cleaner 37. Therefore, the tension roller 27
Only by applying the tension to the intermediate transfer member 24 and maintaining the contact force of the intermediate transfer member cleaner 37, the tension drive structure of the intermediate transfer member 24 can be simplified. Further, for example, even if the intermediate transfer member cleaner 37 is abutted during the secondary transfer to the recording sheet 34, the tension of the intermediate transfer member 24 does not fluctuate greatly, and local expansion and contraction of the image occurs. Absent. Further, since the intermediate transfer member cleaner 37 can be brought into contact during the secondary transfer, the transfer of the first color of the next image to the intermediate transfer member after cleaning can be started immediately. Therefore, the number of prints per unit time of the image forming apparatus is not reduced.

In this embodiment, the intermediate transfer member cleaner 37 as an image forming auxiliary means is separated from and in contact with the tension roller 27 via the intermediate transfer member 24 as an image carrier. The arrangement of the rollers to be stretched is changed, and a guide groove is provided substantially in parallel with the flat portion of the intermediate transfer body 24 wrapped around the roller group in the same configuration as in this example, and a tension roller is attached along the guide groove. The intermediate transfer body 24 is configured to apply tension to the intermediate transfer body 24 by applying a force to the guide groove of the tension roller. The same effect can be obtained even when the structure is separated from and connected to the base member 27.

Next, a third embodiment of the image forming apparatus of the present invention will be described with reference to FIG.

FIG. 5 is a sectional view of an image forming apparatus according to a third embodiment of the present invention, which is a color image forming apparatus generally called a tandem type.

In FIG. 5, the photosensitive members 4 arranged in parallel
9a, 49b, 49c, and 49d are provided around charging rollers 50a, 50b, 50c, and 50d as charging means for uniformly charging the surface of the photoconductor, and lasers as exposure means for exposing the respective photoconductor surfaces. Scanning optical system 51
a, 51b, 51c, and 51d, and developing units 52a, 52b, 52c, and 52d that store yellow, magenta, cyan, and black toners and develop the electrostatic latent images written on the respective photoconductors by the exposure unit. Transfer chargers 55 a, 55 b, 55 c, and 55, which are transfer units for transferring a toner image onto a recording sheet 54 fed from a sheet feeding unit (not shown) and conveyed by a recording sheet conveying belt 53.
d, photoreceptor cleaners 56a, 56b, 56c composed of a rubber blade or the like for cleaning residual toner on the surface of each photoreceptor after transferring the toner image to the recording sheet 54;
56d are arranged.

The formation of each color toner image on each photoconductor is performed in synchronization with the conveyance of the recording sheet 54 by the recording sheet conveyance belt 53, and the recording sheet 5 on which the four color toner images are transferred.
4 is heated and pressurized by the fixing means 57 and carried out of the apparatus.

Here, a description will be given of the structure of the recording sheet conveying belt 53 in the present embodiment, other than the structure of stretching the recording sheet conveying belt 53 and the function of conveying the recording sheet 54 of the recording sheet conveying belt 53.

In FIG. 5, the recording sheet conveying belt 53
Is stretched between belt transport rollers 58 and 59 and a tension roller 60, and is driven by the belt transport rollers 58 or 59. The belt conveying rollers 58 and 59 are fixed to the side plate 61 so as to be rotatable while being fixed at an axial position, and the tension roller 60 is a stretched recording sheet conveying belt 53.
The axial position is supported so as to be movable along a guide groove 62 provided on the side plate 61 substantially parallel to the flat portion 53a, and the recording is performed by being urged by a tension spring 63 in the arrow I direction parallel to the guide groove 62. The tension is applied to the sheet conveying belt 53.

In the tandem type color image forming apparatus of this embodiment, the photosensitive members 49a, 49b, 49c and 49d are used.
It is very important to superimpose the toner images of the respective colors formed on the recording sheet 54 without causing a shift on the recording sheet 54 in order to obtain a good image. A mark indicating a writing start position of each color is recorded as a toner image on the sheet conveying belt 53, and the interval between the marks is read by a toner image position sensor 64 of FIG. Laser scanning optical systems 51a, 51b for
A method of adjusting the scanning exposure start timing of 51c and 51d is adopted. As described above, the recording sheet conveying belt 53 not only conveys the recording sheet 54 but also has a function as an image carrier for carrying each color mark image.

For such a purpose, the recording sheet transport belt 5
Since the position of the mark image carried on 3 becomes unnecessary after its position is read by the toner image position sensor 64, the conveying belt cleaning means 65 composed of a rubber blade or the like as shown in FIG. The guide groove 62 is urged by a moving mechanism (not shown) from the direction of the arrow J substantially perpendicular to the longitudinal direction (the direction of the arrow I) of the guide groove 62 to abut the tension roller 60 via the recording sheet conveying belt 53 to remove the mark image. . When the removal of the mark image is completed, the transport belt cleaning unit 65 is moved in the direction opposite to the arrow J by a moving mechanism (not shown) and is separated from the recording sheet transport belt 53.

Here, the conveyor belt cleaning means 65
Abuts on the guide groove 62 provided in parallel with the urging direction I of the tension roller 60 in a direction substantially perpendicular to the tension roller 60 as in the first and second embodiments. The belt cleaning unit 65 is hardly affected by the separation / contact operation. Therefore, the tension roller 27 alone can apply tension to the recording sheet transport belt 53 as an image carrier and hold the contact force of the transport belt cleaning unit 65 as an image forming auxiliary unit. The structure can be simplified. Further, for example, even when the transport belt cleaning unit 65 is performing the separation / contact operation with respect to the recording sheet transport belt, the transfer charger 55 transfers the toner image formed by any of the photoconductors 49a, 49b, 49c, and 49d.
Since the tension of the recording sheet transport belt 53 does not fluctuate even when the image is transferred onto the recording sheet 54 by a, 55b, 55c, and 55d, local image expansion and contraction does not occur. Also,
Since image formation can be performed irrespective of the separation / contact operation of the conveyor belt cleaning unit 65, the number of prints per unit time of the image forming apparatus does not decrease.

[0053]

As described above, according to the image forming apparatus of the present invention, according to the first aspect of the present invention, the image forming auxiliary means is provided with the image forming auxiliary means for the tension roller for applying the tension to the belt-shaped image carrier. Even if the image carrier is brought into contact with the image carrier, the tension of the image carrier does not fluctuate, and the image carrier supporting roller for backing up the contact between the tension roller and the image forming auxiliary means can be shared. By reducing the number of rollers to be bridged, the apparatus can be made inexpensive and small.

According to the second aspect of the present invention, when the belt-shaped photosensitive member stretched by a plurality of rollers is replaced in a unit state, the replaced photosensitive member contacts an image forming auxiliary unit such as a transfer unit. The tension roller of the photoconductor and the backup roller for backing up the contact between the image forming auxiliary means can be shared and the number of rollers for stretching the photoconductor can be reduced without changing the tension state of the photoconductor even when the photoconductor is in contact. it can.

According to the third aspect of the present invention, in the color image forming apparatus having the intermediate transfer belt, the number of rollers on which the intermediate transfer belt is stretched is reduced, and at the same time, the intermediate transfer member that comes into contact with and separates from the intermediate transfer belt. Even when the separation / contact operation of the image forming auxiliary means such as is performed during image formation, fluctuations in the tension of the intermediate transfer belt can be minimized, so that the number of prints per unit time of the image forming apparatus is not reduced, High-speed image formation can be performed.

In the tandem type color image forming apparatus, the number of rollers for stretching the recording sheet conveying belt is reduced, and at the same time, the position of the alignment mark image transferred onto the recording sheet conveying belt is reduced. Even if the separation / contact operation of the transport belt cleaning means for cleaning the recording sheet is performed during the transfer from any of the photoconductors to the recording sheet, the fluctuation in the tension of the recording sheet transport belt can be minimized, so the image forming apparatus High-speed image formation without reducing the number of prints per unit time.

[Brief description of the drawings]

FIG. 1 is a sectional view of an image forming apparatus according to a first embodiment of the present invention.

FIG. 2 is a sectional view of an image forming apparatus according to a second embodiment of the present invention.

FIG. 3 shows an intermediate transfer member 24 according to a second embodiment of the present invention.
FIG. 4 is a partial cross-sectional view showing the stretching structure of FIG.

FIG. 4 is a partial sectional view showing a contact structure of an intermediate transfer member cleaner 37 according to a second embodiment of the present invention.

FIG. 5 is a sectional view of an image forming apparatus according to a third embodiment of the present invention.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 photoconductor (image carrier) 1 a flat portion of photoconductor 1 2 developing unit roller 3 tension roller 4 cleaning unit roller 5 exposing unit roller 8 developing unit 10 transfer unit 13 cleaning unit 15 Guide groove 24: Intermediate transfer member

Claims (4)

[Claims] A belt-shaped image carrier that carries a toner image; a plurality of rollers that stretch and hang the image carrier;
In an image forming apparatus having an image forming auxiliary unit that comes into contact with the roller via the image carrier, at least one of the rollers is a tension roller that applies tension to the image carrier, and the tension roller is a roller. The image carrier is movably supported by guide grooves provided in a direction substantially parallel to the hung flat portion of the image carrier, and the image carrier is stretched by urging the tension roller along the direction of the guide grooves. An image forming apparatus, wherein the image forming auxiliary unit is urged from a direction substantially perpendicular to the guide groove, and the image forming auxiliary unit comes into contact with the tension roller via the image carrier. 2. The image bearing member is a belt-shaped photosensitive member, and the image forming auxiliary member is a charging unit, a developing unit, or a transfer unit that transfers a toner image from the photosensitive member to another medium. 2. The image forming apparatus according to claim 1, wherein the image forming apparatus is a cleaning unit for cleaning the photosensitive member. 3. The image bearing member is a belt-shaped intermediate transfer member that sequentially transfers toner images formed on a single photosensitive member by a plurality of developing means and collectively transfers the toner images onto a recording sheet, and A transfer unit that transfers the toner image from the intermediate transfer body to a recording sheet, or
2. The image forming apparatus according to claim 1, wherein the image forming apparatus is a cleaning unit for cleaning the intermediate transfer member. 4. A recording sheet transport belt for transporting a recording sheet in which said image bearing member faces a plurality of photosensitive members arranged in parallel, and said image forming auxiliary means cleans said recording sheet transport belt. 2. The image forming apparatus according to claim 1, wherein the image forming apparatus is a unit.