JP3450616B2 - Image forming device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [0001] BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an intermediate transfer member
Image forming devices such as copiers and laser beam printers
I do. [0002] 2. Description of the Related Art FIG. 12 shows a four-color full-color image forming apparatus.
1 shows a schematic configuration of a device (laser beam printer). The image forming apparatus shown in FIG.
(Hereinafter simply referred to as “apparatus body”)
A drum-type electrophotographic photosensitive member (hereinafter, referred to as an image bearing member)
“Photosensitive drum”) 104a. Exposure
The ram 104a is rotatably supported by the apparatus main body 109.
In the figure, a driving means (not shown)
It is driven to rotate in the mark direction (counterclockwise). Photosensitive drum 1
The photosensitive drum 104a is uniformly charged around the area 04a.
Primary charger 104b, which emits a laser beam corresponding to image information.
Exposure means 110 for irradiating and forming a latent image, developing the latent image
A plurality of developing devices 105M, 10M as visible images (toner images);
Rotary developing device 10 provided with 5C, 105Y, 105K
5, carrying the transfer material 102 fed from the paper feeding unit 101
A transfer drum (transfer material carrier) 103 for carrying is arranged.
You. The toner image formed on the photosensitive drum 104a is transferred.
The image is transferred to the transfer material 102 on the transfer drum 103. Exposure
The residual toner on the ram 104a is removed by the cleaner 104c.
And the photosensitive drum 104a is subjected to the next image forming process.
It is. [0004] By repeating the above image forming process,
Transfer material 102 on transfer drum 103
The image is overprinted. Further, each of the above-described components will be described.
And the primary charger 104b is a charging roller to which a voltage is applied.
And is arranged in pressure contact with the surface of the photosensitive drum 104a,
Prior to the formation of a latent image, the surface of the photosensitive drum 104a is uniformly banded.
To charge. The exposure means 110 has a laser diode.
The laser diode
Emits light corresponding to the image signal, and
Irradiate the color. The polygon mirror is driven by the scanner motor
To rotate at high speed to reflect the laser light. With a polygon mirror
The reflected laser light is reflected by the coupling lens 110b and the reflection mirror.
The surface of the photosensitive drum 104a through the
And selectively exposing the photosensitive drum
An electrostatic latent image is formed on the surface of 104a. As described above, the rotary developing device 105
Color developing device 105, ie, magenta and shea, respectively
Containing yellow, black, and black toners
With devices 105M, 105C, 105Y and 105K
The developing devices 105 for these four colors move with respect to the shaft 105e.
Each developing unit is mounted on a rotatable rotating body 105A.
The gear that rotates around the center of the orbiting gear
And the posture is maintained constant. For development, a developing device of a color corresponding to the latent image
(In the figure, the magenta developing device 105M)
Developing facing photosensitive drum 104a by rotation of 5A
Position, where the developing sleeve 105b is
It faces the surface of the photosensitive drum 104a via a minute gap.
Is positioned. The developing device is rotated and moved to the developing position.
Is connected to the high-voltage power supply on the
When the developing bias is applied, the image sleeve 105b is
Is also connected to the driving means from the driving source, and
Will be At the time of development, the developing sleeve 105b
The toner is applied to the surface by the
The toner layer thickness is regulated by the blade 105c.
The photosensitive drum by applying bias and rotating.
The toner is attached to the latent image on the ram 104a, and this latent image is
Develop as a toner image. The paper supply unit 101 transfers the image to a transfer drum 103
The apparatus main body 109 is for feeding the material 102.
The sheet cassette 10 containing the transfer material 102
1a is detachably mounted. Paper cassette 101
The transfer material 102 in a is attached upward by the middle plate 101c.
And the uppermost transfer material is brought into contact with the paper feed roller 101b.
Have been. During image formation, the paper feed
The roller 101b rotates to transfer the transfer material from inside the cassette 101a.
102 are separated one by one and fed to the transfer drum 103
You. The transfer drum 103 is supplied from a paper feeding unit 101.
The transferred transfer material 102 is wound around the photosensitive drum 104a.
The toner image of each color above is transferred onto the transfer material 102 by the transfer unit.
For this purpose, the peripheral speed of the photosensitive drum 104a (process
Speed) at the same speed, for example, V = 75.4 mm / sec.
Rotate in the direction of the arrow (clockwise) in the figure. The transfer drum 103 has a drum center shaft 103.
180mm diameter aluminum cylinder 103 centered at e
An elastic layer 103b is formed on the outer periphery of a with a sponge, rubber, or the like.
Then, a resistance layer 103c is formed on the outer periphery thereof, and the outermost layer
Is formed by forming a dielectric layer 103d. Ma
In addition, at a predetermined position on the outer circumference of the transfer drum 103,
Gripper 103f that grips the leading end of the transferred transfer material 102
It is provided. Furthermore, it can be separated from and connected to the outer periphery of the transfer drum 103
In addition, an electrostatic attraction roller 103g is provided. Suction roller
103g is for transferring the transfer material 102 to the transfer drum 103
Press against the outer periphery of the transfer drum 103 so as to sandwich it
You. Then, the suction roller 103g and the transfer drum 103
The transfer material is a dielectric by applying a voltage between
Charge on the dielectric layer 102d of the transfer drum 103
Induced, and the transfer material 102 is electrostatically applied to the outer periphery of the transfer drum 103.
Adsorb. After the transfer, the cleaner 104c transfers the transfer material 10
2 remains on the surface of the photosensitive drum 104a without being transferred onto
For cleaning residual toner, transfer
In contact with the surface of the photosensitive drum 104a downstream of the nip T
Have been. The cleaner 104c is a waste toner conveying roller
104d, the above-described primary charger 104c, the photosensitive drum 10
4a, etc., as a photosensitive drum unit 104
It has been set. The fixing unit 106 is driven by the pressure roller 10
6a, and heat and pressure are applied to the transfer material 102 by pressing the transfer material 102a.
And a fixing roller 106b. Each color toner image
And transfer transferred from the transfer drum 103 by peeling
Each color toner image is transferred by passing through the material 102
Fixes to the material 102. 106c is the fixing roller 1
06b Apply silicone oil to increase surface releasability
To clean the surface of the fixing roller 106b.
It is a training device. At the time of image formation, the paper feed cassette 101a
The transfer material 102 in the transfer roller is
Is supplied to the system 103. The transfer drum 103 is fed
Grip the leading end of the transferred transfer material 102 with the gripper 103f.
And at the same time electrostatically adsorb on the peripheral surface. On the other hand, the surface is
The uniformly charged photosensitive drum 104 a is
0a, the magenta image is exposed, and the
A latent image of the magenta image is formed. At the same time as this latent image formation
The magenta developing device 105M is driven, and the photosensitive drum 104a
Magenta toner adheres to the magenta latent image formed on
As shown in FIG.
Develop by applying a developing bias voltage of the same potential, and
A magenta toner image is obtained on the memory 104a. And transfer
A transfer potential having a polarity opposite to that of magenta toner is printed on the drum 103.
To transfer the magenta toner image on the photosensitive drum 104a.
The image is transferred onto the transfer material 102 on the transfer drum 103. When the transfer of the magenta toner image is completed,
Of the cyan developing device 105C is rotated and the photosensitive drum 104 is rotated.
a at the development position facing
To form latent images of cyan, yellow, and black, develop and obtain
The transferred toner images are sequentially transferred, and the toner image is transferred onto the transfer material 102.
A full-color image is formed. Transfer drum for holding and transporting transfer material 102
As the 103 rotates four times, one four-color full-color image
An image can be obtained. That is, in this configuration, 180
One full color output in π × 4 / 75.4７５30 seconds
It is. Transfer material 10 after transfer of four-color toner image is completed
2 is separated from the transfer drum 103 to the fixing unit 106
After being conveyed and fixing the toner image by the fixing unit 106,
Discharge onto discharge tray 108 by discharge roller pair 107
Is done. [0019] SUMMARY OF THE INVENTION In the above-described image forming apparatus,
According to the description, such as when the transfer drum 103 is replaced or when a jam is cleared.
The transfer drum 103 is connected to the axis of the drum center shaft 103e.
Configuration to pull out to the front side of the device main body 109 along the line direction
Therefore, the frame of the main body 109 is
I had to cut out a lot. Therefore, the device
The reduction in rigidity of the main body 109 and the deterioration in image quality
There was a problem that occurred. A transfer driver is provided on the front side of the apparatus main body 109.
Handle 103 of the transfer drum 103 to pull out the
It is not easy to handle, and there are also guide rails and other members for pulling out.
Required, resulting in complicated structures and high costs.
There were also problems. Further, the transfer drum 103 is the photosensitive drum 1
04a and the mechanism to drive it
Drive means are required, which will further increase costs
There was a problem. In addition, the positioning of the transfer drum 103
This was hit against the photosensitive drum 104a.
The positional relationship between the transfer drum 103 and the photosensitive drum 104a
And the drive for driving the transfer drum 103 is given priority.
The position with the driving means such as the dynamic gear is not determined,
In this case, normal drive transmission is not performed,
There is also a problem that the drive means such as gears may deteriorate.
Was. Accordingly, the present invention provides an improvement in handling properties.
And the image quality is inferior due to the reduced rigidity of the main body.
To prevent image quality deterioration due to malfunctions and drive transmission.
For providing an image forming apparatus
It is. [0024] Means for Solving the Problems The present invention according to claim 1
Is a rotatable image carrier arranged in the image forming apparatus main body.
And a rotatable intermediate transfer arranged in contact with the image carrier
And a toner image sequentially formed on the image carrier.
Are sequentially primary-transferred onto an intermediate transfer member, and
A plurality of toner images are superimposed, and a plurality of toner images on the intermediate transfer body are superimposed.
In an image forming apparatus that performs secondary transfer of images collectively to transfer material
And both ends in the longitudinal direction along the rotation axis of the intermediate transfer body.
And rotatably supports the intermediate transfer member.
Transfer member holding member and these intermediate transfer members at both ends.
A connecting member for connecting the holding member, and the intermediate transfer body,
Therefore, the intermediate rotation that is detachable from the image forming apparatus main body.
A transfer unit, and the intermediate transfer unit and the image
Cross the rotation axis of the image carrier with the image forming apparatus main body side
Guide the attachment and detachment of the intermediate transfer body unit in the
Guide meansIn addition, the guide means is provided for the intermediate transfer.
First protrusion guide portion protruding outward from the body holding member
And the intermediate transfer disposed on the image forming apparatus main body side.
When the body unit is attached and detached, the first protrusion guide portion slides.
A guide having a first guide portion for guiding a ride operation
And a guide member of the image forming apparatus main body,
Assists the mounting operation of the intermediate transfer unit at the time of mounting
A damper mechanism is provided.
In addition to providing a detachable projection on the damper mechanism,
The protrusion is guided to the damper mechanism on the guide member side.
Establish a guideway,It is characterized by the following. [0025] [0026] [0027] [0028] [0029] [0030] [0031] [0032] [0033] [0034] [0035] [0036] [0037] [0038] [0039] BRIEF DESCRIPTION OF THE DRAWINGS FIG.
An embodiment will be described. <Embodiment 1> FIG.
FIG. 1 is a longitudinal sectional view illustrating a schematic configuration of an image forming apparatus. In addition,
The image forming apparatus shown in FIG.
Printer. First, referring to FIG.
Will be described briefly. The image forming apparatus shown in FIG.
And charging means, exposure means, and developing means disposed around the
Process means such as
The toner image is formed on the image carrier 15 by the steps, and the toner image is formed.
The primary transfer of the image onto the intermediate transfer member 9 is performed in four colors (Y
Low, magenta, cyan, black)
The four color toner images are temporarily superimposed on the intermediary transfer body 9 and then
The toner images of these four colors are collectively secondarily transferred onto the transfer material 2.
You. Then, four colors are transferred onto the transfer material 2 by the fixing unit 25.
Fix the toner image to obtain a four-color full-color image
It is. Next, the configuration of each part of the image forming apparatus will be described.
It will be described in detail. [Image carrier unit (photosensitive drum unit)
G)] The image forming apparatus shown in FIG.
Type electrophotographic photosensitive member (hereinafter referred to as “photosensitive drum”) 1
5 is provided. The photosensitive drum 15 is used as a holder for the photosensitive drum 15.
The cleaner container 14 of the thread cleaning device is integrated.
The photosensitive drum unit (hereinafter simply referred to as the “drum unit”).
13). This drum unit
Reference numeral 13 denotes an image forming apparatus main body (hereinafter simply referred to as “apparatus main body”).
U) Removably incorporated into M
The entire drum unit 13 according to the life of the drum 15
Can be exchanged. In the first embodiment, the image carrier 15
Is on the outer surface of an aluminum cylinder with a diameter of about 60 mm.
Coated with a photosensitive layer made of OPC (organic photoconductor)
And can be freely rotated by the cleaner container 14 described above.
It is supported by. The surface of the photosensitive drum 15 has a drum unit
Cleaner blade 16 which is a component of
The roller 17 is arranged in contact. At one end of the photosensitive drum 15 in the axial direction,
Has a drive motor and a transmission mechanism (both not shown)
The photosensitive drum 15 is moved by an arrow in accordance with an image forming operation.
It is driven to rotate at a predetermined process speed in the direction of the mark R15.
It has become. [Charging Means] As the charging means, contact charging is used.
The method is adopted. The charging means is provided on the surface of the photosensitive drum 15.
And a power source (not shown).
And the charging roller 17 is powered by a power source.
By applying an electric bias, the surface of the photosensitive drum 15 is
The surface is uniformly charged to a predetermined potential of a predetermined polarity. [Exposure Means] Exposure to the photosensitive drum 15
Is performed by the scanner unit 30. That is, the image
When a signal is applied to a laser diode (not shown),
The laser diode of the
Gon mirror 31 is irradiated. This polygon mirror 31
It is rotated at high speed by the scanner motor 31a.
The image light reflected by the polygon mirror 31 is
A predetermined process flow is performed through the
The surface of the photosensitive drum 15 which rotates in the direction of arrow R15 with a speed
To selectively remove the charge in the exposed area,
An electrostatic latent image is formed on the ram 15. [Developing means] The developing means is a photosensitive drum 15
A toner image is formed by attaching toner to the electrostatic latent image formed on
Development (visualization) as a development rotary
23 colors (yellow, magenta, cyan)
Developing device having developing units 20Y, 20M, and 20C
20 and a fixed developing device including a black developing device 21B
21, yellow, magenta, cyan, blue
Four-color full-color image form with four-color toner on the rack
Enable Rotary developing device 20 described above and fixed development
The devices 21 are individually attached to and detached from the device main body M.
Mounted freely. The black component constituting the fixed developing device 21 described above
Developing unit 21B is fixed after being attached to apparatus main body M
And the developing sleeve 21BS is
With a small gap (about 300 μm)
(Development position), the electrostatic latent on the photosensitive drum 15
The image is developed (visualized) with black toner. The black developing device 21B is provided with the toner in the container.
Of the developing sleeve 21BS.
By the application blade 21BB pressed against the outer peripheral surface,
On the outer peripheral surface of the developing sleeve 21BS rotating clockwise.
Apply a thin layer of toner and apply charge to the toner (friction band
Power). Also, a developing bias is applied to the developing sleeve 21BS.
When the photosensitive drum 15 is applied,
Is subjected to toner development. On the other hand, three colors constituting the rotary developing device 20
Of the developing units 20Y, 20M, 20C
Removably held on rotating rotary 23
During image formation, each developing device is
Rotating around the shaft 22 while being held by the
A developing device used for development (a yellow developing device in FIG. 10)
20Y) is at a position facing the photosensitive drum 15 (developing position
), And the developing sleeve 20YS is
With a small gap (about 300 μm)
After being positioned so that the
The latent image is developed (visualized) by attaching toner to the latent image. When forming a color image, once the intermediate transfer member 9
The developing rotary 23 rotates with each rotation, and the yellow developing device 2
0Y, magenta developing device 20M, cyan developing device 20C
The developing process is performed in the order of
The development by B is performed. That is, the intermediate transfer member 9 is 4
Rotate to yellow, magenta, cyan, black
The toner images of the respective colors are sequentially formed on the photosensitive drum 1.
5 and the primary transfer sites T one after another in the order of formation.
₁ Is primarily transferred onto the intermediate transfer member 9 through the
9, the four color toner images are superimposed. FIG. 10 shows that the yellow developing unit 20Y
This shows a state where the position is stationary. Yellow present
The imager 20Y applies the toner in the container by a feed mechanism.
Feeds to roller 20YR and rotates clockwise as shown
Outer peripheral surfaces of coating roller 20YR and developing sleeve 20YS
Clock shown by a coating blade 20YB pressed against
Around the outer periphery of the developing sleeve 20YS which rotates around
Applying a thin layer and applying charge to the toner (frictional charging)
You. The current position is opposite to the photosensitive drum 15 on which the electrostatic latent image is formed.
By applying a developing bias to the image sleeve 20YS,
The electrostatic latent image formed on the photosensitive drum 15 is yellow.
Is developed with the yellow toner image attached to it.
Become. Magenta developing device 20M, cyan developing device 20C
Operates in the same manner as in the case of the yellow developing device 20Y described above.
And a magenta toner image and a cyan toner image, respectively.
Form. The developing units 20Y, 20M, 20C
Each developing sleeve is composed of each developing device 20Y, 20M, 20C.
When rotated to the development position,
High-voltage power supply and drive source for each color development (neither
Shown), and the voltage is sequentially and selectively selected for each color development.
The drive is applied and transmitted. [Intermediate Transfer Body] The intermediate transfer body 9 is a color image
During the image forming operation, the photosensitive drum developed by each developing unit is used.
The toner image on the ram 15 is transferred four times by multiple transfer (primary transfer).
(Transfer), the outer peripheral speed of the photosensitive drum 15 (process
(Rotating in the direction of arrow R9) in synchronism with (speed). Ma
Further, the voltage is applied to the intermediate transfer body 9 which has received the multiple transfer.
Transfer portion T formed between the transfer roller 10 and the transfer roller 10_Two
The transfer material 2 is pinched and conveyed by the
9 and collectively transfer toner images of each color simultaneously (secondary transfer).
Photo). The intermediate transfer member 9 according to the first embodiment is
The outer peripheral surface of the aluminum cylinder 12 with a diameter of 180 mm
Structure covered with elastic layer 11 such as resistance sponge or medium resistance rubber
And The intermediate transfer member 9 is rotatably supported and
The drive is transmitted to a physically fixed gear (not shown).
Rotates in the direction of arrow R9. [Cleaning means] Cleaning means
Is the toner developed on the photosensitive drum 15 by the developing means.
After the toner is transferred to the intermediate transfer body 9,
To remove residual toner remaining on the
The toner is stored in the cleaner container 14. Cleaner container
The waste toner stored in the photosensitive drum 15
Not fill the cleaner container 14 as soon as possible.
When the life of the photosensitive drum 15 is replaced, the cleaner container 14
At the same time, they are exchanged together. [Paper Feeding Unit] The paper feeding unit is a photosensitive drum 15
The transfer material 2 is fed to the image forming section having the intermediary transfer member 9.
And a paper feed cassette containing a plurality of transfer materials 2
1, paper feed roller 3, feed roller 4, double feed prevention retarder
Roller 5, paper feed guide 6, transport roller 7, registration roller
8 and the like. Feed low during image formation
Is driven and rotated in accordance with the image forming operation, and the paper feed cassette
Separately feed the transfer material 2 in the sheet 1 and feed
Guided by guide 6 and resisted by transport roller 7
It reaches the trawler 8. During image forming operation,
The non-rotating operation and the rotation of the roller 8
The rotation operation for transporting the copying material 2 toward the intermediate transfer body 9
This is performed in a predetermined sequence.
The image and the transfer material 2 are aligned. [Transfer Section] The transfer section is a swingable transfer roller.
With 10. The transfer roller 10 is a medium-resistance foamed metal shaft.
It is formed by winding with an elastic body, as shown in the figure,
Can be moved up and down and rotated by a drive member (not shown)
Driven. The transfer roller 10 is placed on the above-mentioned intermediate transfer body 9.
During the formation of four color toner images,
While the body 9 makes multiple rotations, use solid lines so as not to disturb the image.
It is located at the lower retracted position shown in the figure and is separated from the intermediate transfer body 9
are doing. On the other hand, the transfer roller 10 is placed on the intermediate transfer body 9.
After the formation of the four color toner images, the transfer material 2
Time to transfer the color toner image (color image).
At the same time, a cam member (not shown)
Is moved to one of the operating positions, and the intermediate transfer member is transferred via the transfer material 2.
9 is pressed with a predetermined pressure. At this time,
A bias voltage is applied to the transfer roller 10, and the intermediate transfer member is
9 is a secondary transfer portion T_Two Transfer via
The secondary transfer is collectively performed on the material 2. In the first embodiment, the intermediate transfer member 9 and the transfer roller
Roller 10 is driven, so that
The transfer material 2 in a state where the transfer process is performed
It is conveyed at a predetermined speed to the left in the figure, and
It is transported to the receiving part. [Fixing Unit] The fixing unit 25
This is to fix the next transferred toner image.
Fixing roller 26 for applying heat to transfer material 2 and transfer material 2
A pressure roller 27 for pressing against the roller 26;
Each of the rollers 26 and 27 is a hollow roller.
It has heaters 28 and 29 inside and is driven to rotate and
The transfer material 2 is transported. That is, the transfer material 2 holding the toner image is
When transported by the fixing roller 26 and the pressure roller 27
Both are heated and pressed, and the toner image is fixed on the transfer material 2.
Be worn. [Image Forming Operation] Next, FIGS.
Referring to the image forming operation of the image forming apparatus having the above configuration,
Will be described. First, the paper feed roller 3 shown in FIG.
To separate one transfer material 2 in the paper feed cassette 1
The sheet is conveyed to the roller 8. On the other hand, the photosensitive drum 15 and the intermediate transfer body 9
Illustrated at process speed V = 75.4mm / sec
It rotates in the directions of arrow R15 and arrow R9. 60m diameter
m of the photosensitive drum 15 is 60π / 75.4 ≒ 2.5 seconds.
One rotation, the intermediate transfer member 9 having a diameter of 180 mm
One rotation in 75.4 / 7.5 seconds. Also, the photosensitive drum
15 and the intermediate transfer member 9 are connected by a gear (not shown).
Therefore, when the photosensitive drum 15 rotates three times, the intermediate transfer body 9 is
Make exactly one revolution. In FIG. 11, on the outer peripheral surface of the intermediate transfer body 9
When an arbitrary point S of the charging roller 1 reaches the position shown in FIG.
The photosensitive drum 15 whose surface is uniformly charged by 7 is
An image is formed by receiving laser exposure at an exposure position E. Exposure
From the exposure position E of the ram 15 in the direction of arrow 15
Primary transcription site T₁ To the intermediate transfer member 9
From the point S in the direction of the arrow R9 to the primary transfer site T₁ Distance b to
And therefore after a / 75.4 seconds,
Point E at the beginning of writing an image on the surface of the photosensitive drum 15 and intermediate rotation
The point S on the object 9 is the primary transcription site T₁ Matches at
You. In other words, the image has a point S at the end with respect to the intermediate transfer body 9.
Formed counterclockwise. (1) Yellow image (yellow toner image)
Formation The laser irradiation of the yellow image is performed by the scanner unit 30.
A yellow electrostatic latent image is formed on the photosensitive drum 15.
You. Simultaneously with the formation of the electrostatic latent image, a yellow developing device 20Y
To drive the electrostatic latent image on the photosensitive drum 15 into a yellow toner image.
Polarity is the same as the charging polarity of the photosensitive drum 15 so that the toner adheres.
And apply a voltage of approximately the same potential to produce a yellow toner image.
Do the statue. At the same time, the primary transfer site T slightly downstream of the developing unit₁
To transfer the yellow toner image on the photosensitive drum 15 to the intermediate transfer member 9
Is primarily transferred to the outer peripheral surface of. At this time, the intermediate transfer member 9
Primary rotation by applying a voltage of the opposite polarity to the yellow toner described above
Make a photo. When the image to be formed is A3 size, the length is 4
20 mm, and is L from the outer peripheral point S of the intermediate transfer member 9.₁ To the point
An image is formed (a thick line portion on the outer periphery of the intermediate transfer body 9 in FIG. 11).
Minutes). Transfer of yellow toner image to intermediate transfer member 9
Is completed, that is, the point L₁ Is the primary transcription site T₁ To
After that, the developing rotary 23 rotates clockwise and the next
When the magenta developing unit 20M faces the photosensitive drum 15,
It is positioned at the image position. (2) Magenta image (magenta toner image)
Formation Next, a point S (yellow image
When the tip of the circle) makes a circle and reaches the position of the point S.
Laser irradiation of magenta image starts by channel unit 30
Then, similarly to the case of yellow,
Magenta toner adheres to the latent image, and the magenta toner
-An image is formed. Magenta toner on photosensitive drum 15
Image is transferred to primary transfer site T₁ And primary transfer on the intermediate transfer body 9
Copy. The transfer of the magenta toner image to the intermediate transfer member 9 is completed.
Is completed, that is, the point L₁ Is the primary transcription site T₁ Pass
, The developing rotary 23 rotates clockwise and the next cyan
Is located at the developing position facing the photosensitive drum 15
Positioned. (3) Formation of cyan image Next, a point S (yellow and yellow) on the outer peripheral surface of the intermediate transfer body 9 is
And the end of the magenta image) makes a further round to the position of point S.
When it comes, the scanner unit 30 similarly records a cyan image.
Irradiation starts and the feeling is felt in the same way as for magenta.
Cyan toner adheres to the electrostatic latent image on the optical drum 15
Thus, a cyan toner image is formed. On the photosensitive drum 15
Primary transfer site T for cyan toner image₁ On the intermediate transfer member 9
The image is superimposed and transferred onto each of the yellow and magenta toner images. Shi
When the transfer of the toner image to the intermediate transfer member 9 is completed,
That is, point L₁ Is the primary transcription site T₁ After the
Tally 23 rotates clockwise by 60 degrees to contact photosensitive drum 15
No developing device is present at the opposite developing position.
You. (4) Formation of black image Next, at the point S (yellow,
(The tip of the cyan and cyan images) makes a further round, and the position of point S
When it comes to the position, the black
Laser irradiation of the image starts, and then the black developer
21B causes the black toner to adhere to the black toner.
A toner image is formed. Black toner on photosensitive drum 15
-Image is transferred to primary transfer site T₁ And further superimposed on the intermediate transfer member 9
Transfer. As described above, yellow, magenta, cyan, and bra
Latent image formation, development, and toner on the intermediate transfer body 9 in the order of
The primary transfer of the image is sequentially performed four times, and the surface of the intermediate transfer body 9 is
And four colors of yellow, magenta, cyan and black
To form a full-color image composed of images. Transfer of black toner image to intermediate transfer member 9
Is completed, that is, the fourth color black toner image
Intermediate transfer body on which a full-color image after primary transfer has been formed
9 is the secondary transfer site T_Two Before reaching
The transfer material 2 that has been waiting on the registration roller 8 described above is touched.
Conveying is started with the timing. The above-described four-time transfer of each color onto the intermediate transfer member 9
During the formation of the toner image, the image forming apparatus waits at the lower
At the same time, the transfer roller 10 that was not in contact with the body 9 is
Is moved to the other operation position by a cam (not shown), and the transfer material 2 is moved.
Secondary transcription site T between the intermediate transfer member 9_Two Same as pressing
Occasionally a bias of the opposite polarity to the toner is applied to the transfer roller 10
To transfer the full-color image on the intermediate transfer member 9 to the transfer material.
The secondary transfer is simultaneously performed on all four colors simultaneously. The secondary transcription site T_Two The transfer material 2 that has passed through
The toner is peeled off from the intermediate transfer member 9 and transported to the fixing unit 25, and the toner is
After the image is fixed, the discharge roller pairs 34, 35, 36
The image surface onto the discharge tray 37 on the upper surface of the apparatus main body M through
The sheet is discharged downward, and the image forming operation ends. As described above, one full-color image is created.
To do this, the intermediate transfer body 9 needs four rotations of operation,
The time required for this is 30 seconds (= 7.5 seconds × 4).
Incidentally, the intermediate transfer member 9 and its process speed V are equal.
Driven photosensitive drum 15 is a single full-color image.
In inverse proportion to the ratio of the outer diameter to the intermediate transfer member 9 for image formation
Make 12 rotations. The intermediate transfer member 9 has a diameter of 180 mm.
The perimeter is about 565mm and is A3 size image
In the formation, a circumference of 420 mm is used. That is, intermediate rotation
Counterclockwise from point S of the object 9 (opposite to the direction of arrow R9)
To point L₁ Is 420 mm (see FIG. 11).
(See the thick line on the outer periphery of the intermediate transfer member 9). That is, intermediate rotation
420 mm for image formation out of 565 mm of the outer circumference of the object 9
And the remaining 145 mm is not used for image formation.
No. The intermediate transfer member 9 has a constant process speed V = 75.
Because it is rotating at 4mm / sec, it is A3 size
145 / 75.4 = 1.92 seconds of non-color image formation
The image forming time exists and the color developing units 20Y, 20M, 2
It is assigned to the switching time of 0C. The exposure position E of the photosensitive drum 15 and the primary transfer section
Rank T₁ And the yellow developing device 20Y located between
Forming an image and placing it in the next magenta developer 20M
The time allotted to switch is the actual timing
Despite the shift, the point L on the intermediate transfer member 9₁ Turns
Image T₁ It corresponds to the time to reach. Next, the features of the present invention will be described with reference to FIGS.
Will be described. However, the intermediate rotation shown in FIGS.
The photoconductor and the main body of the image forming apparatus show another embodiment.
The structure shown in detail is different from that shown in other figures.
Are different. In the present invention, as shown in FIGS.
The both ends of the transfer body 9 in the longitudinal direction along the rotation axis 9A are
Are held by the intermediate transfer member holding members 40 and 41 having the same configuration.
And the intermediate transfer member holding members 40 and 41
Materials) 45, 46 to form an intermediate transfer as a whole
The body unit 50 is constituted. This intermediate transfer unit
Can be detachably attached to the apparatus main body M (see FIG. 10).
It is configured. The details will be described below. The intermediate transfer member holding members 40 and 41 have
3. As shown in FIG. 4, the front side plate 61 of the apparatus main body M, the rear side
Along the guide members 63 and 64 provided on the plate 62, respectively.
And guide it to a fixed position while supporting the intermediate transfer unit 50
For this purpose, the first projection guide members 42, 49 (see FIG. 2)
), And along the guide members 63 and 64 on the device body M side.
Attitude control for controlling the attitude of the intermediary transfer unit 50 when it is attached and detached
Second protrusion guide members 43 and 44 are provided.
You. FIGS. 3, 4, and 5 show the features of the present invention.
FIG. 3 shows a large characteristic configuration.
3 is shown in FIG.
About the attachment and detachment operation of the intermediate transfer body unit 50,
4 and FIG. 5 will be mainly described. Further, the intermediate transfer member holding members 40 and 41
Is the intermediate transfer member when the intermediate transfer unit 50 is attached or detached.
Handle part (handle) for holding unit 50
71 and 72 are provided. Handles of handle parts 71 and 72
The shape of the intermediate transfer unit 5
As long as it is excellent in operability when attaching and detaching 0
It is not limited to that of, for example,
The completed one may be attached to the coupling member 45.
No. FIGS. 3 and 4 show the arrangement of the intermediate transfer unit 50.
In order to explain the state of attachment / detachment to / from
The front side plate 61 and related members are shown by imaginary lines or
The intermediate transfer unit 50 is also held in hand.
It is shown in a floating state to show the held state. The front plate 61 and the rear plate 62 of the apparatus body M
Guide members 63 and 64 are attached to the respective inner surfaces.
The guide members 63 and 64 have an intermediate transfer unit.
Guide surface for guiding the projection guide members 42 and 49 of
(First guide portion) 63a, 64a and an intermediate transfer body unit
The regular holding unit (the first drop
(Parts) 63b and 64b are provided. Next, the apparatus main body of the intermediate transfer unit 50
The manner of attachment to M will be described. Referring to FIG. 4, intermediate transfer unit 5
0 handle portions 71 and 72 and the intermediate transfer body unit 50
Of the intermediate transfer member holding member 40 while
The plan in which the guide member 42 is attached to the front side plate 61.
On the guide surface 63a of the inner member 63, at the same time, the intermediate transfer
A guide member (not shown) of the body holding member 41
64 on the guide surface 64 a of the intermediate transfer body unit 50.
Is pushed into the apparatus main body M while sliding.
At this time, the intermediate transfer member holding members 40 and 41 are simultaneously
The projection control members 43 and 44 for force control are
Another guide surface 64 (second guide portion) 63c, 64
c (see FIG. 5 for the guide surface 64c).
Let me By doing so, the intermediate transfer unit
50 follows the guide surfaces 63a, 64a, 63c, 64c
Because the posture is controlled, it can be easily mounted without interference with other members.
It can be mounted inside the main body M. Finally, the intermediate transfer body unit 50
The raising guide members 42 and 49 are used to properly maintain the guiding members 63 and 64.
The device body is supported by the holding portions 63b and 64b.
M. Removal from the apparatus body M is as described above.
It can be performed in the reverse procedure to the case of mounting. In addition, take out
Pull out the intermediate transfer unit 50 almost obliquely upward.
It's just a simple action, so it's even more powerful than
It is easy. According to the first embodiment, the intermediate transfer member 9 is
An intermediate transfer body unit for moving toward and away from the photosensitive drum 15
50 denotes a projection guide member 4 of the intermediate transfer member holding member 40.
2, and the protrusion guide member 49 of the intermediate transfer member holding member 41
Is configured to swing around the swing center. guide
The S portion of the members 63 and 64 (see FIGS. 4 and 5) is used for posture control.
So that the projection guide members 43 and 44 can swing.
G is provided. As shown in FIG. 6 and FIG.
In order to bring the image bearing member 9 into contact with the photosensitive drum 15, an intermediate transfer member
The holding members 40 and 41 are provided with a pressing member accommodation portion 48.
You. A compression coil spring 80 is housed in the pressing member housing member 48.
And a lever 84 provided on the apparatus main body M side.
The cap member 81 is further pressed, and the intermediate transfer body 9 is exposed to light.
The ram 15 can be brought into contact with an appropriate contact pressure. More specifically, FIG. 6 shows an intermediate transfer member unit.
The state in which the knit 50 is attached to the apparatus main body M is shown. In FIG.
The lever 84 provided on the apparatus main body M is used for intermediate transfer.
Evacuate so as not to interfere with the attachment / detachment operation of body unit 50
In this state, the intermediate transfer member 9 is
Away from the system 15. In the first embodiment, the intermediate rotation
The moving body 9 moves with respect to the photosensitive drum 15 in conjunction with the lever 84.
Although it is designed to perform the contact and separation operation, the photosensitive
It is also possible to configure so as to be separated from the system 15. In the pressing member housing section 48, a pressing member is provided.
The compression coil spring 80 and the cap member 81 are accommodated.
ing. The cap member 81 is easily pushed by the lever 84.
In addition, the compression coil spring 80 easily expands and contracts in the housing portion 48.
It is provided for. Also, the cap member 81 is
The stopper 82 provided on the inter-transfer member holding member 40.
To prevent the compression coil spring 80 from jumping out.
Also. FIG. 6 shows that the intermediate transfer member 9 and the photosensitive drum 15
Shows the contact state. Operation of lever 84 on device body M side
As a result, the lever 84 is supported from the retracted position in FIG.
It rotates about the shaft 84a, and
Press the compression coil spring 80 together with the cap member 81
Put in. Thereby, the projection guide members 42 and 49 are centered.
The intermediate transfer body unit 50 swings clockwise in FIG.
So that the intermediate transfer body 9 contacts the photosensitive drum 15
Become. The contact pressure changes the spring constant of the compression coil spring 80.
Can be set as appropriate. The lever 84 has a certain amount of compression coil.
When the spring 80 is pushed in, the fixing means (not shown)
Fixed. Therefore, the intermediate transfer member 9 and the photosensitive drum
The contact pressure of No. 15 is maintained at an appropriate value. Further, the pressing of the lever 84 is released.
The tip of the lever 84 is inclined with respect to the intermediate transfer member holding member 40.
Press the surface 40a to rotate the intermediate transfer body unit 50 counterclockwise.
7 can be returned to the state shown in FIG.
Since the transfer body unit 50 is stabilized in this position,
The moving body unit 50 is simply set in the posture set from the apparatus main body M.
You can simply take it out. Next, referring to FIG. 8, which is a detailed view of the part A in FIG.
The features of the present invention will be further described with reference to FIGS. In FIG. 8, a rear plate 62 (not shown) is attached.
The projection guide member 49 of the attached guide member 64
The regular holding part (not shown) has a similar effect.
Positioning member for protrusion guide member independent of inner member 64
It is 90. Attached to front side plate 61 (not shown)
The guide member 63 has the same shape as the guide member 64.
Guideway shape, damper (damper mechanism) 66
The positions are the same and face each other. However,
The regular holding part of the protrusion guide member is independent so that
It is not necessary and may be integral with the guide member 63.
It is stiff. In the following description, the guide member 64 will be described.
A description will be given of the case where the guide member 64 and the guide member 64 are paired.
The inner member 63 has the same configuration and operation. As described above, the protrusion guide members 49 and
The attitude control protrusion guide member 44 is provided with guide surfaces 64a, 64c.
By simply sliding, the posture of the intermediate transfer unit 50
It is controlled and can be easily attached to and detached from the device main body M.
Then, the projection guide member 49 is set to the regular holding position 90b.
Part from the guide surface 90c (the first part)
The process is completed by dropping the image to 90a. This allows for intermediate
The regular mounting / removal of the transfer body unit 50 and the image forming position
The setting to the holding position 990b is easy to slide.
It can be done with a single operation. Also, as described above, the protrusion guide member
49 is held at the regular holding position 90b, the intermediate transfer member
Move the knit 50 toward and away from the photosensitive drum 15 as the swing center.
adjust. The protrusion guide member 49 moves to the regular holding position 90b.
Is held, and the intermediate transfer body 9 contacts the photosensitive drum 15.
In this case, the holding slope 90a is formed by the reaction force of the contact pressure.₁ Pressed to
And maintained by the weight of the intermediate transfer unit 50.
Slope 90a₁ , 90a_Two To the normal holding position
It does not float from 90b. Of course, the angle Y shown in FIG.
0a₁ Even if a reaction force of the contact pressure is generated, the projection guide member 49
Is set at an angle that does not float. Further, the way of the guide surface 64a of the guide member 64
64d of depression (second depression) inside
By providing a depression 64e in the middle of the inner surface 64c.
The projection guide member 49 is inserted into the depression 64d,
The force control projection guide member 44 falls into the depression 64e.
And the intermediate transfer unit 50 is attached and detached.
It will be held on the way. This is the intermediate transfer unit
For example, when clearing jams without removing the
It is effective for Of course, the projection guide members 49, 44
If it can be held, the depression 64
Install a more aggressive locking mechanism instead of d and 64e
You may make it. Also, near the entrance of the guide surface 64a
A third recess 64f may be provided, in which case
Starts mounting using the recess 64f.
The intermediate transfer unit when
50 can be temporarily held. Next, the intermediate transfer member unit 50 forms an image.
Is set to the regular holding position,
A state where the drive is transmitted to the intermediate transfer member 9 will be described. As shown in FIG. 2, the axial direction of the intermediate transfer body 9
Flanges 200 and 201 are integrated
Is attached to the flange 201 on the side receiving the drive.
Intermediate transfer member gear 2 integrally or integrally mounted
01a is provided. This intermediate transfer body gear 201a
To the intermediate transfer member drive gears 202, 2
03 denotes a projection guide member 49 of the intermediate transfer member holding member 41.
It is arranged coaxially with the axis L and is held by the intermediate transfer member holding member 41.
Is held. Intermediate transfer member drive gears 202 and 203 are medium
Drive is transmitted by a shaft (not shown) in the intermediary transfer member holding member 41.
Is reached. Intermediate transfer member drive gear 202 and intermediate transfer member gear
201a is the same member, that is, the intermediate transfer member
Positioning by the holding member 41,
The center distance is accurately maintained. Therefore, intermediate transfer
Drive from body drive gear 203 to intermediate transfer body gear 201a
Good driving without unevenness is transmitted. Next, driving to the intermediate transfer member driving gear 203
The drive transmission from the source will be described. As shown in FIG. 9, the intermediate transfer unit 5
0, slide the projection guide member 49 to the proper holding position.
When held at 90b, it is coaxial with the protrusion guide member 49.
A certain intermediate transfer member driving gear 203 is also held at the illustrated position.
You. Here, the position of the motor 91 as the driving source will be described.
And a motor 9 in a hole 90 d provided in the positioning member 90.
Pressing or fitting the flange part 1
The position of the motor gear 91a is determined simultaneously with the positioning of the motor 91.
I will get over. That is, the motor 91 serving as the driving source and the motor
Data gear 91a and intermediate transfer member drive gear 203 are the same.
Material, that is, the positioning member 90
ing. Motor gear 91a and intermediate transfer member drive gear 20
3 are positioned by the same positioning member 90 with the same center distance X.
Accuracy is assured by
It can be seen that the drive is transmitted. This enables intermediate transfer
Slide the body unit 50 to drop the projection guide member 49
Intermediate transfer from the drive source just by dropping it into the insertion part 90a
Transmits normal drive without drive unevenness to body gear 201a
be able to. In the first embodiment, the motor gear 9
Drive is transmitted directly from 1a to the intermediate transfer body drive gear 203
Drive system with low transmission loss
Can be. Further, the drive is received at the swing center of the intermediate transfer body 9.
The intermediate transfer member 9 is not fixed,
Even if there is a driving force, the holding slope 90a₁ , 90a_Two Received by
Since the driving force is stopped, the driving force is applied to the photosensitive drum 1 of the intermediate transfer body 9.
It does not affect the abutment of the No. 5. In addition,
Intermediate transfer member 9 repeatedly swings slightly with ram 15
However, since the center-to-center distance X does not change, the influence on driving is small.
There is also the advantage that there is no. In the first embodiment, the guide member 64 and the position
The determining member 90 is a separate member. This is a positioning
The holding member is formed integrally with the female member 90 by the guide member 64.
Position with other units (mostly drive units)
And the positioning member 90 is fixed to the unit.
This is because there may be a better configuration for drive transmission.
Of course, if they have the same effect,
The portion 90a may be provided integrally with the guide member 64. Also,
If the guide member 63 has no drive transmission, the regular holding portion
It is not necessary to make the (drop portion) a separate member. Further, it is possible to maintain good drive transmission,
Reduction of the load on the photoreceptor intermediate transfer member holding member and projection guide member,
To improve operability, both guide members 63 and 64
It is effective to attach a damper to one side. Less than
In the description below, the guide member 64 will be described.
The 63 side has the same operation as the similar configuration. As shown in FIG. 8, a damper is
-66 is provided. In the first embodiment, the oil damper is
Used. For transmitting the damper effect to the mating member
In the first embodiment, the damper gear 66a is a member.
Projecting. In addition, the intermediate transfer body unit 50
To receive the par effect, the intermediate transfer member holding member 41
A projection 302 (see FIG. 2) having a shape that meshes with the
See). Further, the guide member 64 has a damper gear.
Gear 66a and the gear 302a of the protrusion 302 (301)
Guide surface (guide path) so that (301a) is securely engaged
By providing 64 g and guiding the protrusion 302 to the gap B
The gears always mesh to ensure a damper effect
be able to. The oil damper of the first embodiment is internal
With a spring clutch and only when mounted
The damper does not work at the time of removal
It is sexual and does not feel heavy when taken out. Further, as shown in FIG.
Protrusion 301 (302) for receiving the intermediate transfer member
The projection guide member 42 (4) provided on the holding member 40 (41)
9) and between the protrusion guide members 43 (44) for attitude control.
Perpendicular to line C connecting the hearts and attitude control with projection guide member 42
Between the straight lines D and E passing through the center of the
(Shaded area in the figure). At this position, there is a projection 301 (302).
For example, if the intermediate transfer body unit 50 is
Either protrusion guide until the setting to the holding position is completed
Either of materials 42 and 49 falls in the normal holding position first
While correcting the behavior of dropping into the part 90a,
-The effect can be maintained. The effect of the damper is as follows.
a and the intermediate transfer member driving gear 203
Gear deterioration prevention and drive performance maintenance, or intermediate transfer
Operation when dropping the body unit 50 into the regular holding position
There is an improvement in the nature. Any kind of damper as long as it has a damper effect
It may be a par, a mechanism, or may be provided on both sides or only one side. As described above, the image formation according to the present invention is described above.
According to the apparatus, handling of the intermediate transfer member 9 is easy.
The intermediate transfer body unit 50 can be attached to the front
Between the main body M and the rear side plate 62
And projecting guide members 42, 49, etc.
By making the center of oscillation as it is, contact and separation with the photosensitive drum 15
The operation can be performed easily and a good drive transmission
And the performance of the intermediate transfer body 9 itself is good.
Can be maintained in a good condition, and the
Can be. [0118] As described above, according to the present invention,
Intermediate transfer using an intermediate transfer member and an intermediate transfer member holding member
Unit, and the intermediate transfer unit is
By attaching and detaching in the direction crossing the body rotation axis
The intermediate transfer unit in the direction of the rotation axis of the image carrier.
Unlike the conventional method, it is necessary to attach and detach the
The main body of the image forming apparatus does not require a large
Image quality degradation due to reduced rigidity of the
Damage due to rubbing of the image carrier when attaching and detaching.
Improve handling without causing damage
Can be. Further, at the time of mounting, the intermediate transfer unit
Slide along the first and second guides, and
Just drop the projection guide into the recess,
It can be easily connected to the driving means of
Good drive transmission can be realized.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view showing a configuration of an intermediate transfer unit. FIG. 2 is a perspective view showing a configuration of an intermediate transfer unit viewed from a direction opposite to FIG. 1; FIG. 3 is a perspective view for explaining an attaching / detaching operation of an intermediate transfer body unit to / from the image forming apparatus main body. FIG. 4 is a perspective view for explaining an attaching / detaching operation of an intermediate transfer body unit to / from an image forming apparatus main body according to another embodiment. FIG. 5 is a perspective view for explaining an attachment / detachment operation and a swing operation of an intermediate transfer body unit with respect to an image forming apparatus main body according to another embodiment. FIG. 6 is a diagram for explaining an operation of contacting and separating an intermediate transfer member with respect to a photosensitive drum, and is a diagram illustrating a contact state. FIG. 7 is a diagram for explaining an operation of moving the intermediate transfer member toward and away from the photosensitive drum, and is a diagram illustrating a separated state. FIG. 8 is an enlarged view of a guide member and a positioning member. FIG. 9 is a view for explaining holding and drive transmission of a projection guide member. FIG. 10 is a longitudinal sectional view illustrating a schematic configuration of the entire image forming apparatus according to the present invention. FIG. 11 is a diagram showing an A3 size image forming operation. FIG. 12 is a longitudinal sectional view showing a schematic configuration of an entire conventional image forming apparatus. [Description of Signs] 2 Transfer material 9 Intermediate transfer member 9A Rotary shaft 15 of intermediate transfer member Image carrier (photosensitive drum) 40, 41 Intermediate transfer member holding member 42, 49 First protrusion guide members 43, 44 Second Projection guide members 45, 46 Connecting member (coupling member) 50 Intermediate transfer body unit 61 Front side plate 62 Rear side plate 63, 64 Guide members 63a, 64a First guide portion (guide surface) 63c, 64c Second guide portion (guide) Surface) 64b Regular holding position (first depression) 64d Second depression 64g Guide path (guide surface) 66 Damper mechanism (damper) 90 Positioning member 90a First depression 91 Drive means (motor) 91a Drive means (Motor Gear) 203 Intermediate Transfer Body Drive Gear M Image Forming Apparatus Main Body

────────────────────────────────────────────────── ─── Continuation of front page (56) References JP-A-3-191368 (JP, A) JP-A-4-110871 (JP, A) JP-A-8-123214 (JP, A) JP-A 8- 137181 (JP, A) JP-A-8-6471 (JP, A) JP-A-5-197226 (JP, A) JP-A-7-311533 (JP, A) JP-A-3-252667 (JP, A) JP-A-8-54786 (JP, A) JP-A-7-72744 (JP, A) JP-A-8-16067 (JP, A) Japanese Utility Model Application Sho 62-135165 (JP, U) (58) (Int.Cl. ⁷ , DB name) G03G 15/01-15/01 117 G03G 15/16 G03G 15/00 550 G03G 21/16-21/18

Claims (1)

(57) [Claims] A rotating unit disposed in an image forming apparatus main body;
Existing image carrier and freely rotatable placed in contact with the image carrier
And an intermediate transfer member, which are sequentially formed on the image carrier.
Primary transfer of the transferred toner image onto an intermediate transfer
A plurality of toner images are superimposed on the transfer body, and the
Image formation for secondary transfer of multiple toner images to a transfer material at once
In the device, Arranged at both ends in the longitudinal direction along the rotation axis of the intermediate transfer body.
And rotatably supports the intermediate transfer member.
An intermediate transfer member holding member, Connecting member for connecting these intermediate transfer member holding members at both ends
When, The image forming apparatus main body with the intermediate transfer member.
To form a removable intermediate transfer unit. On the intermediate transfer body unit and the image forming apparatus main body side,
The intermediate transfer member in a direction intersecting a rotation axis of the image carrier;
A guide is provided to guide the unitKe The guide means extends outward from the intermediate transfer body holding member.
A first projecting guide projecting from the image forming apparatus;
At the time of attachment / detachment operation of the intermediate transfer body unit which is arranged on the body side
Guide the sliding operation of the first projection guide portion
A guide member on which a first guide portion is formed, The intermediate member at the time of mounting on the guide member of the image forming apparatus main body.
A damper mechanism is provided to assist the transfer unit mounting operation.
Ke Disengaged with the damper mechanism on the intermediate transfer member holding member side
A possible projection is provided, and a front side is provided on the guide member side.
Providing a guide path for guiding the projection to the damper mechanism, An image forming apparatus comprising: