JP2002229385A - Image forming device - Google Patents

Abstract

(57) [Problem] To easily replace a belt-shaped image carrier even in a configuration in which an inner installation member such as a waste toner tank is provided in an inner space formed by a belt-shaped image carrier. To be able to do it. An intermediate transfer unit includes a drive roller.
4, primary transfer roller 45, secondary transfer opposing roller 46, cleaning opposing roller 47, and tension roller 48
And an intermediate transfer belt 41 as a belt-shaped image carrier stretched over the plurality of rollers. The side plate 92 on the front side of the device is composed of a fixed side plate 94 and a detachable side plate 98 detachably attached to the fixed side plate 94 with screws 96.
When the removal side plate 98 is pulled out, the cleaning opposing roller 47 and the waste toner tank 49 provided in the inner space of the intermediate transfer belt 41 are pulled out integrally.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming apparatus such as a copying machine, a printer, a facsimile, and the like.
The present invention relates to an image forming apparatus having a belt-shaped image carrier stretched over a plurality of rollers.

[0002]

2. Description of the Related Art A belt-shaped image carrier (photoreceptor, intermediate transfer body, etc.) in an image forming apparatus of this type is usually mounted by being stretched over a plurality of rollers having an interval in the vertical and horizontal directions. In recent years, there has been an increasing demand for miniaturization and high-density of image forming apparatuses. For example, Japanese Patent Application Laid-Open No. 8-16057 discloses that an inner space formed by a belt-shaped There is disclosed a configuration in which a waste toner tank for storing waste toner cleaned from the belt-shaped image carrier is provided in the inner space. As described above, by mounting the waste toner tank and the like in the space inside the belt-shaped image carrier, the space in the apparatus that has been wasted until now can be effectively used.

[0003]

A belt-shaped image carrier such as a photoreceptor or an intermediate transfer member is inevitably deteriorated in photosensitive characteristics (image forming ability) or has a long life due to use over time. For this reason, it is necessary to replace after a certain use time. When there is nothing in the inner space formed by the belt-shaped image carrier stretching structure, the belt is moved by moving some of the plurality of rollers inward from the belt-shaped image carrier. It can be loosened, and the belt-shaped image carrier can be removed and replaced.

However, in the configuration in which the inner installation member such as the waste toner tank exists in the inner space as described above, the space for moving the roller inward is small and it is difficult.
The replacement of the belt-shaped image carrier has a problem that the work operability is extremely poor. Further, since the waste toner tank occupies most of the inner space, it is difficult to remove the waste toner tank for discarding the waste toner due to a small space.

Therefore, the present invention provides an image forming apparatus capable of easily exchanging a belt-shaped image carrier even when an inwardly installed member such as a waste toner tank is present in an inner space of the belt-shaped image carrier. The purpose is to provide. Another object of the present invention is to provide an image forming apparatus in which a waste toner tank is provided in an inner space of a belt-shaped image carrier, and in which waste toner can be easily discarded.

[0006]

In order to achieve the above object, according to the first aspect of the present invention, a plurality of rollers supported between side plates and a belt-shaped image carrier stretched over the plurality of rollers are provided. Body, and an image forming apparatus having an inner installation member provided by utilizing an inner space of the belt-shaped image carrier, wherein one of the side plates is a majority of the plurality of rollers. A fixed side plate that supports an end of the fixed side plate, and a detachable side plate that is detachably provided on the fixed side plate and that supports an end of the remaining roller among the plurality of rollers. The configuration is such that the remaining roller is provided so as to be integrally removed with the removal side plate when removed.

According to a second aspect of the present invention, in the image forming apparatus of the first aspect, the one side plate is a side plate located on the operation surface side of the apparatus main body.

According to the third aspect of the present invention, the first or second aspect is provided.
In the image forming apparatus described above, the configuration is such that the number of the remaining rollers is one.

According to the fourth aspect of the present invention, the first to third aspects are provided.
In the image forming apparatus described in any one of the above, a configuration is employed in which the inner installation member is a waste toner tank that stores waste toner.

According to a fifth aspect of the present invention, in the image forming apparatus of the fourth aspect, the waste toner tank is provided integrally with the side plate for removal.

According to the sixth aspect of the present invention, in the fourth or fifth aspect,
In the image forming apparatus described above, the storage capacity of the waste toner tank is set to be substantially the same as the amount of waste toner collected by the time of replacement of the belt-shaped image carrier. .

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to FIG.
7 will be described with reference to FIG. First, a schematic configuration and operation of an electrophotographic color printer (hereinafter, simply referred to as a color printer) 1 as an image forming apparatus according to the present embodiment will be described. The color printer 1 includes a photoreceptor unit 10, a writing optical unit 20, a developing unit 30 as a developing unit, and an intermediate transfer unit 40.
And a secondary transfer unit 50 as a transfer unit, a fixing unit 60 as a fixing device, a double-sided printing paper reversing unit 70, and the like. The color printer 1 is a Bla
ck: black (hereinafter, referred to as Bk), Cyan: cyan (hereinafter, referred to as C), Magenta: magenta (hereinafter, referred to as M)
), Yellow: Yellow (hereinafter referred to as Y)
Are sequentially visualized on a photoreceptor belt 11 as an image carrier of the photoreceptor unit 10, and these are superimposed to form a final four-color full-color image.

A photoreceptor belt 11 as a belt-shaped image carrier rotates in a clockwise direction indicated by an arrow A. Around the photoreceptor cleaning device 12, a charging roller 13, and a selected developing unit , An intermediate transfer belt 41 of the intermediate transfer unit 40, and the like. The photoreceptor belt 11 is stretched between the driving roller 14, the primary transfer opposing roller 15, and the stretching roller 16, and is rotated in the direction of arrow A by a drive motor (not shown). When the photoconductive belt 11 having a seam is used, a seam mark is provided in a non-image area at the end of the photoconductor belt 11, and a detection is performed by a sensor (not shown) to form an image while avoiding the seam.

The writing optical unit 20 converts color image data into an optical signal, performs optical writing corresponding to each color image, and forms an electrostatic latent image on the photosensitive belt 11.
The writing optical unit 20 includes a semiconductor laser 21 as a light source, a laser emission drive control unit (not shown), a polygon mirror 22, and three reflection mirrors 23a, 23b, and 23.
c etc.

The developing unit 30 includes a Bk developing device 31K,
C developing device 31C, M developing device 31M, Y developing device 31Y,
Each developing unit is configured by a not-shown contact / separation mechanism or the like that moves the developing device in the left-right direction in the drawing to perform a contact / separation operation with respect to the photosensitive belt 11. Each of the developing units 31K, 31C, 31M, and 31Y has a developing sleeve 32K, 32 that rotates while carrying a developer on the surface to develop an electrostatic latent image on the surface of the photoreceptor belt 11.
C, 32M, and 32Y, and developer paddles 33K, 33C, 33M, and 3 that rotate to pump up and agitate the developer.
3Y, and a developer storage case 34K, 3 for storing the developer.
4C, 34M, 34Y and the like. Each of the developer accommodating cases 34K, 34C, 34M, and 34Y accommodates a one-component developer composed of a toner of each color as a developer. In the illustrated example, a Bk developing device 31K containing black toner, a C developing device 31C containing cyan toner, an M developing device 31M containing magenta toner, and a Y developing device containing yellow toner are arranged in order from the lower side of the apparatus main body. 31Y is provided.

Each developing unit 31K, 31C, 31M, 31Y
The toner inside is charged to a predetermined polarity, and a developing bias is applied to each of the developing sleeves 32K, 32C, 32M, and 32Y by a developing bias power supply (not shown), and the developing sleeves 32K, 32C, 32M, and 32Y are transferred to the photosensitive belts. 11 is biased to a predetermined potential. Also,
The contact / separation mechanism is provided by a motor (not shown) from each developing device 31.
When an electromagnetic clutch (not shown) for transmitting drive to K, 31C, 31M, and 31Y is turned on, the drive force moves developer storage cases 34K, 34C, 34M, and 34Y to photoreceptor belt 11 side (right side in the figure). It is made to let. At the time of development, each of the developing devices 31K, 31C, 31M, 3
Any one selected from 1Y moves and comes into contact with the photoreceptor belt 11. On the other hand, when the electromagnetic clutch is turned off to cancel the drive transmission, the developing device that has been in contact with the photosensitive belt 11 moves in a direction away from the photosensitive belt 11 (left side in the figure).

In the standby state of the color printer main body, any of the developing units 31K, 31C, 31
M and 31Y are also set at positions separated from the photoreceptor belt 11. When the printing operation is started, optical writing using a laser beam and formation of an electrostatic latent image are started based on the color image data (hereinafter, an electrostatic latent image based on Bk image data is referred to as a Bk electrostatic latent image. The same applies to Y).
In order to enable development from the front end of the Bk electrostatic latent image, the rotation of the Bk developing sleeve 32K is started before the front end of the Bk electrostatic latent image reaches the Bk development position, and the Bk electrostatic latent image is converted to Bk toner. Develop with. Thereafter, the developing operation of the Bk electrostatic latent image area is continued, but when the trailing end of the Bk electrostatic latent image passes the Bk developing position, the Bk developing device 31K separates from the photoreceptor belt 11 and immediately moves to the next position. The developing device of the color a contacts the photoreceptor belt 11. This is completed at least before the leading end of the electrostatic latent image based on the next image data reaches the developing position.

The intermediate transfer unit 40 includes an intermediate transfer belt 41 as a belt-shaped image carrier, a belt cleaning device 42, a position detection sensor 43, and the like.
The intermediate transfer belt 41 is stretched around a driving roller 44, a primary transfer roller 45, a secondary transfer opposing roller 46, a cleaning opposing roller 47, and a tension roller 48,
The drive is controlled in the direction of arrow B by a drive motor (not shown). A plurality of position detection marks (not shown) are provided in a non-image area at the end of the intermediate transfer belt 41, and one of these position detection marks (the position detection sensor 43 at the start of the image forming operation). Is detected by the position detection mark, and image formation is started at this detection timing.

The belt cleaning device 42 includes a cleaning brush 42a, a contact / separation mechanism (not shown), and the like, while the first color Bk image is being transferred to the intermediate transfer belt 41, and 2, 3, 4, and 5. While the color image is being transferred to the intermediate transfer belt 41, the cleaning brush 42a is separated from the surface of the intermediate transfer belt 41 by a contact / separation mechanism. The toner cleaned from the surface of the intermediate transfer belt 41 is stored in a waste toner tank 49 as an inner installation member provided inside the intermediate transfer unit 40 (inner space).

A transfer paper as a transfer material is accommodated in a transfer paper cassette 80 provided at a lower portion of the apparatus main body.
The transfer paper is fed and conveyed toward registration roller pair 82 by paper feed rollers 81a, 81b, 81c. On the right side of the color printer 1, a manual feed tray 83 for manually feeding OHP paper or thick paper is provided.

The secondary transfer unit 50 comprises a secondary transfer roller 51 and a swing mechanism (not shown) provided with a clutch and the like for bringing the secondary transfer roller 51 into and out of contact with the intermediate transfer belt 41. I have. The secondary transfer roller 51 swings about the rotation axis of the swing mechanism in synchronization with the timing at which the transfer paper reaches the transfer position. The transfer paper and the intermediate transfer belt 41 are driven by the secondary transfer roller 51 and the secondary transfer facing roller 46.
And are contacted at a constant pressure. The position accuracy of the parallelism of the secondary transfer roller 51 with the secondary transfer opposing roller 46 is maintained by a positioning member (not shown) provided in the intermediate transfer unit 40. The positioning roller (not shown) provided on the secondary transfer roller 51 causes
The contact pressure of the next transfer roller 51 is made uniform. At the same time when the secondary transfer roller 51 is brought into contact with the intermediate transfer belt 41, a transfer bias having a polarity opposite to that of the toner is applied to the secondary transfer roller 51, and the superimposed toner image on the intermediate transfer belt 41 is collectively transferred onto transfer paper.

The above units can be easily attached to and detached from the apparatus main body. For example, in FIG. 1, when removing the intermediate transfer unit 40, the front cover (not shown) is opened, and the unit is slid from the back side to the front side of the paper.

In the color printer 1 having the above configuration, when the image forming cycle is started, first, the photosensitive belt 11
Is rotated in the clockwise direction of arrow A, and the intermediate transfer belt 41 is rotated in the counterclockwise direction of arrow B by a drive motor (not shown). A position detection mark (not shown) provided on the intermediate transfer belt 41 is detected by a position detection sensor 43,
Bk toner image formation, C toner image formation, M toner image formation, and Y toner image formation are performed on the photoreceptor belt 11 according to the detection timing of the position detection mark, and finally Bk,
A toner image is formed on the intermediate transfer belt 41 in the order of C, M, and Y. At this time, the bias applied to the primary transfer roller 45 generally increases the voltage sequentially, but differs depending on the resistance characteristics of the intermediate transfer belt 41 and the like.

The Bk toner image is formed as follows.
The charging roller 13 uniformly charges the photoreceptor belt 11 by an applied voltage of a power supply (not shown). The laser light LD for writing performs exposure based on the Bk color image signal. When this exposure is carried out, the exposed portion of the photoreceptor belt 11 which is initially uniformly charged loses the charge proportional to the amount of exposure light, and a Bk electrostatic latent image is formed. When the Bk toner on the Bk developing sleeve 32K comes into contact with the Bk electrostatic latent image, the toner does not adhere to a portion where the charge of the photoreceptor belt 11 remains, and a portion having no charge, that is, an exposed portion Bk toner is adsorbed, and a Bk toner image similar to the electrostatic latent image is formed. The Bk toner image formed on the photoreceptor belt 11 contacts the intermediate transfer belt 41 at the primary transfer position. At this primary transfer position, a nip is formed between the intermediate transfer belt 41 and the photosensitive belt 11 by the primary transfer roller 45 and the primary transfer opposing roller 15, and the Bk toner image is formed on the primary transfer roller 45. The Bk toner image is transferred to the intermediate transfer belt 41 by applying a bias having a polarity opposite to the above.

Some untransferred residual toner on the photoreceptor belt 11 is cleaned by a photoreceptor cleaning device 12 in preparation for reusing the photoreceptor belt 11. The collected toner is stored in a waste toner tank (not shown) via a collection pipe (not shown).

On the photosensitive belt 11 side, the process proceeds to the C image forming step after the Bk image forming step, and the position detecting sensor 43
Is written by the laser light LD based on the C image data in accordance with the detection timing, and a C electrostatic latent image is formed. After the rear end of the previous Bk electrostatic latent image has passed, and
Before the leading end of the C electrostatic latent image arrives, the Bk developing device 31K retracts from the developing position, the C developing device 31C is set at the developing position, and the C electrostatic latent image is developed with the C toner. Hereafter, C
The development of the electrostatic latent image area is continued, but when the rear end of the C electrostatic latent image has passed, the C developing unit 31C retreats from the developing position in the same manner as in the case of the Bk developing unit 31K, and the next. M developing unit 3
Move 1M to the development position. This is also completed before the leading end of the next M electrostatic latent image reaches the developing position. The M and Y image forming processes are the same as the processes of Bk and C described above, since the operations of forming and developing the electrostatic latent image are the same as those of the processes of Bk and C described above.

The intermediate transfer belt 41 includes a photosensitive belt 1
The toner images of Bk, C, M, and Y which are sequentially formed on the same are sequentially aligned on the same surface to form a four-color superimposed toner image. In the next two transfer steps, the four-color toner image is formed. Batch transfer to transfer paper.

At the time when the image forming operation is started, the transfer paper is fed from either the transfer paper cassette 80 or the manual feed tray 83 and stands by at the nip of the registration roller pair 82. The intermediate transfer belt 41 is attached to the secondary transfer roller 51.
When the leading edge of the four-color superimposed toner image approaches, the registration roller pair 82 is driven so that the leading edge of the transfer paper just coincides with the leading edge of the toner image, and the registration between the transfer paper and the toner image is performed. Will be Then, the transfer paper is superimposed on the toner image on the intermediate transfer belt 41 and passes through the secondary transfer position. At this time, the transfer paper is charged by the transfer bias by the secondary transfer roller 51, and most of the toner image is transferred onto the transfer paper.

The transfer paper on which the four-color superimposed toner images have been transferred collectively from the intermediate transfer belt 41 is conveyed to a fixing unit 60. The toner image is melted and fixed at the nip between the fixing belt 61 and the pressure roller 62 controlled to a predetermined temperature, sent out of the apparatus main body (in the direction of arrow C), stacked on the paper output tray 84 face-down, and full-color copied. Get.

When performing double-sided printing, the fixing unit 6
The transfer paper that has passed through 0 is guided in the direction of arrow D by the double-sided switching claw 85 and sent to the double-sided printing paper reversing unit 70. After the rear end of the transfer paper has passed the reversing switching claw 71, the reversing roller pair 72 stops, and the transfer paper also stops. The reversing roller pair 72 starts reversing after a certain blank time, and the transfer paper starts to switch back. At this time, the reversing switching claw 71 is switched, and the transfer paper is guided in the direction of arrow E and sent to the registration roller pair 82. The transfer paper sent to the registration roller pair 82 is turned upside down with the registration roller pair 8
Stand by at the nip of No. 2. The registration roller pair 82 is driven at a predetermined timing, the transfer paper is sent to the secondary transfer position, and the four-color superimposed toner image is collectively transferred from the intermediate transfer belt 41, and then the toner image is fused and fixed by the fixing unit 60. Is sent out of the apparatus body.

The surface of the photoreceptor belt 11 after the primary transfer is
The photosensitive member is cleaned by the photoreceptor cleaning device 12 and is uniformly discharged by a discharge lamp (not shown). The surface of the intermediate transfer belt 41 after the transfer of the toner image onto the transfer paper is cleaned by pressing the cleaning brush 42a of the belt cleaning device 42 with a contact / separation mechanism. The toner cleaned from the intermediate transfer belt 41 is stored in a waste toner tank 49.

Next, a configuration for facilitating replacement of the intermediate transfer belt 41 as a belt-shaped image carrier in the intermediate transfer unit 40 will be described. FIG. 2 shows the drive roller 44 and the primary transfer roller 4 of the side plate 90 as a roller support plate located on the back side of the apparatus opposite to the operation surface side of the apparatus body.
5, a support structure for the secondary transfer opposing roller 46, the cleaning opposing roller 47, and the tension roller 48 is shown. The primary transfer roller 45 and the tension roller 48
The rotating shafts 45a and 48a are directly supported by the side plate 90. Drive roller 44, secondary transfer facing roller 46,
The cleaning opposing roller 47 has a rotation shaft 44
a, 46a, 47a are supported by bearings 90a, 90b, 90c provided on the side plate 90, respectively.

FIG. 3 is a side plate 92 serving as a roller support plate located on the operation surface side of the apparatus main body. The driving roller 44, the primary transfer roller 45, the secondary transfer opposed roller 46, the cleaning opposed roller 47, and the tension roller 48 are provided. 2 shows a support configuration for the. The side plate 92 is disposed substantially parallel to and opposed to the side plate 90. The side plate 92 includes the drive roller 4
4, fixed side plate 9 supporting the other end of primary transfer roller 45, secondary transfer opposing roller 46, and tension roller 48
4 and a detachable side plate 98 which is detachably provided on the fixed side plate 94 with a screw 96. 1
The rotation shafts 45 a and 48 a of the next transfer roller 45 and the tension roller 48 are directly supported by the fixed side plate 94. The drive roller 44 and the secondary transfer opposing roller 46 respectively rotate their rotating shafts 44 a and 46 a
Are supported by bearings 94a and 94b provided at the bottom.

The cleaning opposing roller 47 has its rotating shaft (the other end) 47a supported by a bearing 98a provided on a side plate 98 for removal. Further, a waste toner tank 49 is formed integrally with the removal side plate 98. The storage capacity of the waste toner in the waste toner tank 49 is set to be substantially the same as the amount of waste toner collected by the time the intermediate transfer belt 41 is replaced. This storage capacity can be determined, for example, by the average amount of waste toner collected by the time the intermediate transfer belt 41 is replaced.

The cleaning opposing roller 47 is provided so as to be integrally removed with the removal side plate 98 when the removal side plate 98 is removed from the fixed side plate 94. Therefore, the side plate 98 for removal, the cleaning opposing roller 47, and the waste toner tank 49 constitute one unit. The cleaning counter roller 47 can be integrally removed by, for example, fixing the bearing 90c to the side plate 90 and fixing the bearing 98a to the removal side plate 98.

FIG. 4 shows a single unit configuration on the side plate 98 for detachment, and FIG. 5 shows a single unit configuration on the side of the fixed side plate 94. In FIG.
Reference numeral 4c denotes a screw hole of the screw 96. As shown in FIG.
When the two screws 96 are removed to separate the removal side plate 98 from the fixed side plate 94, the tension of the cleaning opposing roller 47 with respect to the intermediate transfer belt 41 is eliminated. A loose state is obtained as shown by the dashed line.

Next, the operation of replacing the intermediate transfer belt 41 and the operation of discarding waste toner will be described with reference to FIGS. When the image forming ability of the intermediate transfer belt 41 is reduced or the life of the intermediate transfer belt 41 is reached, the intermediate transfer belt 41 is replaced. In the replacement work, first, the front cover (not shown) of the apparatus main body is opened, and the screw 96 of the intermediate transfer unit 40 is removed as shown in FIG. After removing the screw 96, the removal side plate 98 is pulled out to the front side of the apparatus. As the removal side plate 98 is pulled out, the cleaning opposing roller 47 and the waste toner tank 49 are integrally pulled out as one unit. In FIG. 6, the intermediate transfer belt 41 is shown by a two-dot chain line for easy understanding.

As shown in FIG. 7, after the unit including the detaching side plate 98 is pulled out, the loosened intermediate transfer belt 4 is removed.
1 is pulled out from the unit including the fixed side plate 94 to the front side of the apparatus. The unit including the pulled out side plate 98 is turned upside down or inclined to discard the waste toner at a predetermined position.

The new intermediate transfer belt 41 is fixed to the fixed side plate 94.
Then, the unit including the detachable side plate 98 with the waste toner tank 49 emptied is positioned at a predetermined position, and the detachable side plate 98 is fixed to the fixed side plate 94 with screws 96. Removal side plate 98
Is fixed, the new intermediate transfer belt 4
1 is in a predetermined stretched state.

In the above embodiment, an example in which the present invention is applied to an intermediate transfer unit has been described. However, the present invention can be similarly applied to a photosensitive unit 10 having a photosensitive belt 11 as a belt-shaped image carrier. Further, the present invention can be similarly applied not only to the belt-shaped image carrier, but also to another unit having a belt-shaped body requiring replacement or maintenance.

[0041]

According to the first aspect of the present invention, a plurality of rollers supported between the side plates, a belt-shaped image carrier stretched over the plurality of rollers, and the belt-shaped image carrier In the image forming apparatus having an inner installation member provided by utilizing the inner space, one of the side plates is a fixed side plate that supports most end portions of the plurality of rollers, The fixed side plate is configured to include a detachable side plate that is detachably provided on the fixed side plate and supports an end of the remaining roller among the plurality of rollers. When the detachable side plate is detached from the fixed side plate, the remaining roller also includes As it was configured to be removed integrally with the removal side plate,
Even if the inner installation member is present, the belt can be easily replaced by removing the belt-shaped image carrier whose image forming ability has deteriorated or has reached the end of its life and by removing the side plate.

According to the second aspect of the present invention, since the one side plate is a side plate located on the operation surface side of the apparatus main body, the replacement operation can be easily performed by opening the front cover of the apparatus main body. Can be performed, and the simplification of the replacement operation can be further improved.

According to the third aspect of the present invention, since the number of the remaining rollers is one, the attaching and detaching operation of the detaching side plate can be easily performed with a small weight.

According to the fourth aspect of the present invention, since the inner installation member is a waste toner tank for storing waste toner, the inner space formed by the belt-shaped image carrier is effectively used. It can be used for

According to the fifth aspect of the present invention, since the waste toner tank is provided integrally with the detaching side plate, the waste toner tank can be pulled out with the operation of pulling out the detaching side plate. Thus, the waste toner in the waste toner tank can be easily disposed of.

According to the sixth aspect of the present invention, the capacity of the waste toner tank is set to be substantially the same as the amount of waste toner recovered by the time the belt-shaped image carrier is replaced. Therefore, the waste toner in the waste toner tank does not need to be discarded until the belt-shaped image carrier is replaced, and the work efficiency can be improved because there is no need to work twice.

[Brief description of the drawings]

FIG. 1 is a schematic front view of a color printer as an image forming apparatus according to an embodiment of the present invention.

FIG. 2 is an enlarged front view showing a supporting relationship between a side plate located on the back side of the apparatus main body and a plurality of rollers.

FIG. 3 is an enlarged front view showing a support relationship between a side plate located on the front side of the apparatus main body and a plurality of rollers.

FIG. 4 is an enlarged front view of only a unit including a removal side plate in a side plate located on the front side of the apparatus main body.

FIG. 5 is an enlarged front view of only a unit including a fixed side plate in a side plate located on the front side of the apparatus main body.

FIG. 6 is a schematic perspective view of a state in which only a unit including a detachable side plate is drawn out of the intermediate transfer unit.

FIG. 7 is a perspective view showing a state in which only a unit including a removal side plate is pulled out from the intermediate transfer unit, and a belt-shaped image carrier can be loosened and pulled out.

[Explanation of symbols]

 44 Driving roller as a roller 45 Primary transfer roller as a roller 46 Secondary transfer opposing roller as a roller 47 Cleaning opposing roller as a remaining roller 48 Tension roller as a roller 49 Waste toner tank as an inner installation member 90 Side plate 92 One side plate 94 Fixed side plate 98 Removal side plate

Claims (6)

[Claims] A plurality of rollers supported between side plates, a belt-shaped image carrier stretched over the plurality of rollers, and an inner space of the belt-shaped image carrier are provided. An image forming apparatus having an inner installation member, wherein one of the side plates is a fixed side plate that supports most ends of the plurality of rollers, and is detachably provided on the fixed side plate. A detachable side plate that supports an end of the remaining roller among the plurality of rollers is configured to be detached integrally with the detached side plate when the detached side plate is detached from the fixed side plate. An image forming apparatus, which is provided. 2. An image forming apparatus according to claim 1, wherein said one side plate is a side plate located on an operation surface side of the apparatus main body. 3. The image forming apparatus according to claim 1, wherein the number of the remaining rollers is one. 4. An image forming apparatus according to claim 1, wherein said inner installation member is a waste toner tank for storing waste toner. 5. An image forming apparatus according to claim 4, wherein said waste toner tank is provided integrally with said side plate for removal. 6. An image forming apparatus according to claim 4, wherein the capacity of said waste toner tank is set to be substantially the same as the amount of waste toner collected by the time of replacement of said belt-shaped image carrier. An image forming apparatus, comprising: