JP2000162893A - Image-forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent image defects such as soil on a transfer material, transfer slippage by improving accuracy in positioning a transfer-material guide member with respect to a fixing nip. SOLUTION: A fixing nip is formed by pushing up a transfer holder 218B, together with a carrying device 205B by means of a carrying press device 206B, thereby abutting a transfer roller 217B to a photoreceptor drum 207B. By the pushing up of the transfer holder 218B at the time, the inclined face 220C of a positioning member 220B pushes up the positioning member 219B of a transfer- material guide member 203B, so that a projection 212B is engaged with the positioning hole 211B of a frame 201C, and the transfer-material guide member 203B is thereby positioned. The projection 212B during the engagement is pressed to the first restricting face 211C and second restricting face 211D of the positioning hole 211B by the inclined face 220C, and therefore is deterred from being moved unnecessarily. That is, the rattling of the fitted parts is eliminated, and the accuracy in positioning the transfer-material guide member 203B with respect to a fixing nip is improved.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to an image forming apparatus provided with a transfer member and a pre-transfer guide which can freely contact and separate from an image carrier.

[0002]

2. Description of the Related Art Conventionally, in an image forming apparatus such as a copying machine and a laser beam printer, contact transfer charging to a photosensitive drum (image carrier) is performed to improve workability when exchanging a photosensitive drum (image carrier) or paper jam. (Transfer member) and a transfer material guide member (pre-transfer guide) are configured to be detachable from each other. After the above-mentioned operation is completed, the contact transfer charger is brought into contact with the photosensitive drum again, and the transfer material guide member is moved. Has been positioned.

However, at this time, there are many components between the photosensitive drum and the transfer material guide member and between the transfer material guide member and the contact transfer charger, and the position of the transfer material guide member is reduced due to play between the components. There was a risk of image displacement due to misalignment. In addition, since the transfer material guide member is lifted while being in contact with the contact transfer charger, the toner adheres to the transfer material guide member, and the transfer material may be stained on the back.

Here, a typical conventional example will be described with reference to FIGS. 9 and 10. FIG.

9 and 10, 201A is a photosensitive drum unit, 202A is a contact transfer charger, 203A is a transfer material guide member, 204A is a registration roller, 205A
A is a transport device, and 206A is a transport pressurizing device.

First, FIG. 9 shows a state in which the contact transfer charger 202A is released from the photosensitive drum 207A. Then, the contact transfer charger 202A by the conveying pressure device 206A for lowering the position of the transport apparatus 205A vertically rises while being in contact with M ₁ parts to the transfer material guide member 203A, a contact transfer charger 202A The attached toner is attached to the hatched portion 203R of the transfer material guide member 203A. For this reason, as shown in FIG. 10, there is a problem that the image is stained due to the oblique line portion on the back surface of the sheet 208A to which the toner has been conveyed. FIG. 10 shows a state in which the contact transfer charger 202A and the transfer material guide member 203A are set at predetermined positions by raising the transport device 205A. At this time, the photosensitive drum 2
07A and the transfer roller 217A, a transfer nip portion T is formed, and the positioning auxiliary member 2 attached to the contact transfer charger 202A and the transfer material guide member 203A, respectively.
It contacts between 09A and 210A.

A photosensitive drum unit 201A is provided between the photosensitive drum unit 201A and the transfer material guide member 203A.
When the positioning hole 211A in the inside and the projection 212A of the transfer material guide member 203A are fitted, the transfer material guide member 20 is formed.
3A becomes X _1, configured to ensure X ₂ position of. Although positional accuracy _{X 1, X 2, Y 1} , Y ± 0.2mm and precision in _two directions both of the transfer material guide member 203A with respect to the photosensitive drum 207A is required, the through many parts thereto Position accuracy must be guaranteed.

[0008]

[SUMMARY OF THE INVENTION However, the fitting backlash of P ₁ parts by positional shift caused by the mounting position accuracy of the component tolerances and each device is extremely difficult to ensure the positional accuracy of the. Therefore, the transfer material guide member 203A deviated position of, joined by a predetermined value or more forces at P ₁ parts of P ₂ parts, the transfer material guide member 203A deformed.

As described above, image defects occur due to displacement and deformation of the transfer material guide member 203A due to repeated pressurization and release of the transport device 205A, and man-hours for ensuring accuracy when assembling the image forming apparatus. Problem has occurred.

The present invention has been made in view of the above-described circumstances, and improves the positional accuracy of a pre-transfer guide with respect to a transfer nip to prevent image defects such as contamination of a transfer material and transfer misalignment. It is an object of the present invention to provide an image forming apparatus capable of forming an image of high quality.

[0011]

According to a first aspect of the present invention, there is provided a transfer nip portion in which a transfer member is brought into contact with an image carrier, and the transfer nip portion is transferred to the transfer nip portion. In an image forming apparatus for transferring a toner image formed on the image carrier to the transfer material by inserting a material, an image carrier support member rotatably supporting the image carrier, and the transfer member And the transfer member is rotatably supported, and the transfer member is disposed at a transfer position in contact with the image carrier and a retracted position separated from the image carrier. A pre-transfer guide that moves from a release position separated from the image carrier to a guide position for guiding a transfer material inserted into the transfer nip portion in conjunction with movement of the transfer member from the retracted position to the transfer position. And The image carrier support member is provided with a positioning hole that opens to the transfer member side at the retracted position, and the pre-transfer guide is provided with a first positioning portion having a positioning protrusion that can be inserted into and removed from the positioning hole. Moving the transfer member from the retracted position to the transfer position by the transfer holder and abutting the first positioning portion to move the pre-transfer guide from the release position to the guide position. And a second positioning portion for engaging the positioning projection with the positioning hole is provided, and one of the first positioning portion and the second positioning portion is engaged with the positioning hole. An inclined surface for preventing movement of the positioning projection is provided.

According to a second aspect of the present invention, in the image forming apparatus of the first aspect, the positioning hole regulates a position of the positioning projection pressed by the inclined surface when the positioning projection is engaged. First not coplanar with each other
And a second regulating surface.

The present invention according to claim 3 provides the present invention according to claim 1 or 2
In the above image forming apparatus, the positioning hole of the image carrier supporting member is provided near the transfer nip portion.

According to a fourth aspect of the present invention, in the image forming apparatus of the third aspect, the positioning hole of the image carrier support member is provided on the upstream side of the transfer nip portion in the insertion direction of the transfer material. , Characterized in that.

The present invention according to claim 5 is based on claims 1, 2,
In the image forming apparatus according to the third or fourth aspect, one of the first positioning portion and the second positioning portion is formed of an elastic member.

The present invention according to claim 6 is based on claims 1, 2,
In the image forming apparatus according to any one of 3, 4, or 5, the positioning hole of the image carrier supporting member, the first positioning portion of the pre-transfer guide, and the second positioning portion of the transfer holder are transferred to the transfer device. It is provided near both ends in the longitudinal direction of the member.

[0017]

Embodiments of the present invention will be described below with reference to the drawings.

First, the features of the present invention will be outlined, and then more specifically.

In the present invention, as shown in FIGS. 4 and 5, a transfer member (transfer roller) is provided on an image carrier (photosensitive drum) 207B.
217B is abutted to form a transfer nip T, and a transfer material is inserted through the transfer nip T to transfer a toner image formed on the image carrier 207B to the transfer material. An image carrier support member (frame) 201C rotatably supporting the image carrier 207B, and a transfer member 217B rotatably supported, and the transfer member 217B is moved to a transfer position M2 where it abuts on the image carrier 207B. Evacuation position M separated from image carrier 207B
1 and a transfer holder 218B which can be freely attached to and detached from the image carrier 2 in conjunction with the movement of the transfer member 217B from the retracted position M1 to the transfer position M2 by the transfer holder 218B.
07B from the release position N1 (see FIG. 4) separated from
A pre-transfer guide (transfer material guide member) 203B that moves to a guide position N2 for guiding a transfer material inserted into the transfer nip portion T, and an image carrier support member 201C.
Is provided with a positioning hole 211B that opens on the side of the transfer member 217B at the retracted position M1.
A projection (positioning projection) that can be inserted into and removed from the positioning hole 211B.
A first positioning portion 219B having a second positioning portion 212B is provided, and the first positioning portion 219B is brought into contact with the transfer holder 218B as the transfer member 217B moves from the retracted position M1 to the transfer position M2 by the transfer holder 218B. A second positioning portion 220B for moving the pre-transfer guide 303B from the release position N1 to the guide position N2 and engaging the positioning protrusion 212B with the positioning hole 211B is provided, and the first positioning portion 219B and the second positioning portion 220B are provided. An inclined surface 220C for preventing movement of the positioning protrusion 212B engaged with the positioning hole 211B is provided on one of them.
It is characterized by the following.

The positioning hole 211B is provided between the first regulating surface 211C and the second regulating surface 211C, which are not coplanar with each other, for regulating the position of the positioning projection 212B pressed by the inclined surface 220C when the positioning projection 212B is engaged. Regulatory surface 21
1D.

Further, a positioning hole 211B of the image carrier supporting member 201C is provided near the transfer nip portion T.

In addition, the positioning hole 211B of the image carrier support member 201C is provided on the upstream side of the transfer nip portion T in the insertion direction of the transfer material.

Next, one of the first positioning portion 219B and the second positioning portion 220B is formed by an elastic member.

Next, the positioning hole 211B of the image carrier supporting member 201C, the first positioning portion 219B of the pre-transfer guide 203B, and the second positioning portion 220B of the transfer holder 218B are connected to both ends of the transfer member 217B in the longitudinal direction. It is provided near (see FIG. 6).

Hereinafter, this will be described in more detail.

<First Embodiment> FIG. 1 shows an example of an image forming apparatus according to the present invention. FIG. 1 is a longitudinal sectional view showing a schematic configuration thereof.

In FIG. 1, the image forming apparatus main body S ₁ is
Has a scanner section S ₂ of the image reading means for reading image information of an image plane such as a book original thereon, and an image forming section S ₃ of the image forming unit thereunder, further sheet thereunder is constructed by assembling a feeding device S _4.

The scanner section B includes a scanning system light source 201,
Platen glass 202, the image forming apparatus main body S openable document pressing plate 203 with respect to _1, the mirror 204, the lens 20
5, a light receiving element (photoelectric conversion element) 206, an image processing unit, and the like. A book original such as a book, thick paper, or curled paper, a sheet original, or the like is placed on the platen glass 202 with the original surface facing down.
When the reading is started by pressing the reading start key, the scanning system light source 201 is set to the platen glass 20.
2 is scanned in the direction of arrow a to read image information on the document surface. The image information of the document read by the scanning light source 201 is processed by an image processing unit, converted into an electric signal, and transmitted to the laser scanner 111.

[0029] Here, the image forming apparatus main body S _1, if the input processing signal of the image processing unit to a laser scanner 111 functions as a copying machine, functions as a printer by inputting the output signal of the personal computer. Also, if a transmission signal from another machine's facsimile device is input or a processing signal of the image processing unit is transmitted to another machine's facsimile device,
Functions as a facsimile. That is, the image forming apparatus main body S ₁ is a copier, a printer, and functions as a facsimile.

On the other hand, the lower portion of the image forming section S ₃ is fitted with a sheet cassette 1, the sheet cassette 1 is constructed as a single feed unit with two lower cassette 1a and the upper cassette 1b. In this embodiment, three sets of feeding units U1, U2, and U3 are mounted, and six cassettes are mounted. Then, a pair of feed unit U1 located above the detachably attached to the image forming apparatus main body S _1, 2 pairs of feeding unit U of the lower
2, U3 is detachably attached to the apparatus S ₄ sheet feeding.

The sheets (transfer material) accommodated in the sheet cassettes 1a and 1b are fed out by a pickup roller 3, which is a feeding rotating body, as will be described later, and a feed roller 4 and a retard roller 5 constituting separation means. After the sheets are separated and fed one by one by the cooperating action, they are conveyed by conveying rollers 104 and 105 constituting a conveying means,
Led to the registration roller 204B, so as to synchronize with the image forming operation is fed to the image forming section S ₃ by the resist roller 204B.

The image forming section S ₃ is a drum type electrophotographic photosensitive member (hereinafter, referred to as “photosensitive drum”) as an image carrier.
207B, an image writing optical system 113, a developing device 114, a transfer charger 202B, and the like. Then, the photosensitive drum 2 uniformly charged by the charger 114
A laser beam corresponding to the image information emitted from the laser scanner 111 onto the surface of the
To form an electrostatic latent image. The electrostatic latent image is developed as a toner image by attaching toner to the developing device 114, and the toner image is synchronized with the rotation of the photosensitive drum 207B by the registration roller 204B. The sheet is conveyed to the first surface of the conveyed sheet by the transfer charger 202B.

In FIG. 1, reference numeral 205B denotes a conveying device for conveying the sheet on which the toner image is formed, 213B denotes a fixing device, and 119 denotes a discharge roller. The sheet on which the toner image is formed is transferred to the fixing device 213 by the transport device 205B.
After being conveyed to B and heated and pressurized to fix the toner image on the surface, the toner image is discharged by the discharge roller 119 onto the discharge tray 120 arranged outside the image forming apparatus main body, and is stacked.

When toner images are formed on both sides of the sheet, the sheet discharged from the fixing device 213B is sandwiched by discharge rollers 119, and the trailing end of the sheet is set at a branch point 20.
7, the discharge roller 119 is reversed, and the inverted sheet is once placed on the double-sided tray 121, conveyed by the conveyance rollers 104 and 105, reaches the registration roller 204 </ b> B, and After the toner images are formed on the two surfaces in the same manner as described above, the toner images are discharged onto the discharge tray 120 and stacked.

Next, the features of the present invention will be described with reference to FIGS.
This will be described with reference to FIG.

FIG. 2, FIG. 3 is one in which the image forming section S ₃ of the above-described image forming apparatus viewed from the front.

In these figures, 201B is the photosensitive drum 2
07 and a frame (image carrier supporting member) 201C rotatably supporting the same. Reference numeral 202B denotes a contact transfer charger having a transfer roller 217B as a transfer member. 203B is a transfer material guide member as a pre-transfer guide, 204B is a registration roller, 205B is a conveying device, 213B is a fixing device, 206
B is a transport pressurizing device.

The contact transfer charger 202B is connected to the transfer holder 21
8B, the holder 218B is fixed to the transfer device 205B by screws 214B.
Conveying apparatus 205B has a configuration in which also move the contact transfer charger 202B in conjunction to move the Y _3, Y ₄ direction by the conveying pressure device 206B around the fulcrum 215B. The transfer material guide member 203B is rotatable to pivot about the fulcrum 216B to Y _3, Y ₄ directions.

Here, further details will be given with reference to FIGS. 4, 5, and 6, which show the details of the configuration of the Q section. FIG. 4 shows a state in which the transfer device 205B is released. In this state, the transfer roller 217B is located at the retreat position M1, and the transfer material guide member 203B is located at the release position N1. Figure 5 is of pressurization of the transport apparatus 205B, FIG. 6 is viewed from Y ₄ directions. In the pressurized state shown in FIG. 5, the transfer roller 217B moves to the transfer position M
2, a transfer nip portion T is formed between the transfer guide member 203B and the photosensitive drum 207B.
Is disposed at a guide position N2 for guiding a sheet inserted into the transfer nip portion T.

207B is a photosensitive drum, 217B is a transfer roller, 218B is a transfer holder, 223B is a torsion coil spring, 224B is a static elimination needle, 219B is a positioning member (first positioning portion) D attached to the transfer material guide member 203B. , 220B are positioning members (second positioning portions) attached to the contact transfer charger 202B.

In FIGS. 4, 5 and 6, the transfer roller 217B is connected to the transfer holder 218B via a bearing 221B, and the torsion coil spring 223B
Has a force is applied configuration Y ₃ direction by. Further, a positioning member 220B is attached to the transfer holder 218B, and even if the transport device 205B is raised, the positioning member 219B and the positioning member 220B are in contact with each other, so that the transfer roller 217B and the transfer material guide member 203B are in contact with each other. Thus, the transport device 205B can be moved up without any movement.

Next, a description will be given of a case where the transfer device 205B is pressurized and set at a predetermined position with reference to FIG. A positioning member 219B that is in contact with the positioning member 220B is fixed to the transfer material guide member 203B. The positioning member 219B is provided with a projection 212B that fits into a positioning hole 211B provided in the photosensitive drum unit 201B. Positioning hole 211
B has a substantially horizontal first regulating surface 211C and a substantially perpendicular second regulating surface 211D.

In the embodiment, as shown in FIG. 6, positioning members 219B and 202B are provided at both ends of transfer material guide member 203B and contact transfer charger 202B (both ends in the left and right direction in the sheet conveying direction). The same effect can be obtained by providing two or more places.

Here, a method of positioning the transfer material guide member 203B will be described with reference to FIGS.

FIG. 7 shows a state in which the transfer device 205B is being pressed.

As the transfer device 205B is pressurized, first, the positioning member 220B is moved to the positioning member 219.
B, the transfer roller 217B and the transfer material guide member 2
03B without contact with the transfer material guide member 203.
B is lifted Y ₃ direction. As a result, the toner from the transfer roller 217B does not adhere to the back surface 203R (near the hatched portion) of the transfer material guide member 203B, so that the toner is applied to the back surface (the hatched portion) of the sheet 208B guided by the transfer material guide member 203B. No contamination occurs. Incidentally, with the positioning member 220B is because it has an inclined surface 220C which is inclined Z ₁ direction, the positioning member 219B has a force is applied constantly to the T ₁ direction, the transfer material guide member 203B to T _1, X ₃ direction It is in a state of being backlashed in this direction. The positioning member 220B is attached to the transfer holder 218B, and a torsion coil spring 222B is arranged between the positioning member 220B and the transfer holder 218B.
Positioning member 220B along with always force is applied to the Y ₃ direction, Y _3, Y ₄ are in a state movable in a direction.

Subsequently, when the transfer device 205B is further pressurized and set at a predetermined position, as shown in FIG.
Positioning member 2 fixed to transfer material guide member 203B
The projection 212B provided on 19B is inserted into the positioning hole 211B provided on the photosensitive drum unit 201B. At this time, the transfer material guide member for 203B are constantly pressurized to Y _3, X ₃ direction by the inclined surface 220C of the positioning member 220B as described above, always Y ₃ are projections 212B to positioning holes 211B, X ₃ direction Can be mounted at the same position where the fitting play is brought closer. That is, the protrusion 212B is provided on the first regulating surface 211 of the positioning hole 211B.
C, the Y ₃ direction and X ₃
Since the position in the direction is regulated, there is no play in fitting. By providing the inclined surface 220C such a positioning member 220B, in the case of repeated lifting of the transport apparatus 205B also play shifting between the positioning hole 211B projection 212B, and a transfer material guide member 203B always X ₃ direction can be set to a position, the fixing nip portion N of the image forming section S _3, it is possible to accurately return always initial position transfer material guide member 203B. by this,
The positioning adjustment of the transfer material guide member 203B at the time of assembling the image forming apparatus is also facilitated, the number of assembling steps is reduced, the cost can be reduced, and a toner image with stable image quality can be obtained without image defects.

Further, since the positioning hole 211B is arranged near the upstream side of the fixing nip portion T, the positioning accuracy of the transfer material guide member 203 with respect to the fixing nip portion T, particularly, the most downstream position in the transfer material guide member 203 The positioning accuracy of the side part is increased.

The inclination direction of the inclined surface 220C is reversed, and the play between the positioning hole 211B and the projection 212B is reduced to X _4.
The same effect as in the present embodiment can be obtained even in the case of moving in the direction.

In the present embodiment, the positioning member 22
0B is converted into Y ₃ and Y ₄ by the torsion coil spring 222B.
Therefore, the pressure applied to the transfer material guide member 203B can always be increased to the set value of 3.9 N (Newton). For this reason, since the transfer material guide member 203B is not deformed as described in the related art, image defects can be prevented.

In this embodiment, the positioning member 220B
Although the torsion coil spring 222B is used as the pressing means, similar effects can be obtained with an elastic member. The positioning member 219B is made of an elastic material, and the positioning member 220B is made of an elastic material.
The same is true even if is fixed.

Further, the inclined surface 220 C is transferred to the transfer holder 21.
The same effect as described above can be achieved by providing the transfer member guide member 203B with the positioning member 219B instead of the 8B positioning member 220B.

In the above-described embodiment, the first and second regulating surfaces 211C and 211D of the positioning holes 211B provided in the photosensitive drum unit 201 are formed substantially horizontally and substantially vertically, respectively. Not. For example, an inverted V-shaped positioning hole 211B is formed by the first and second regulating surfaces 211C and 211D.
Even if the circular projection 12B is formed in a circular shape and the circular projection 212B is engaged with the inverted V-shaped positioning hole 211B, substantially the same effects as described above can be obtained.

[0054]

As described above, according to the present invention,
By providing one of the first positioning portion and the second positioning portion with an inclined surface for preventing movement of the positioning protrusion engaged with the positioning hole, the positional accuracy of the pre-transfer guide with respect to the transfer nip portion is improved. As a result, it is possible to prevent image defects such as contamination of the transfer material and transfer misalignment, and to form an image with uniform image quality.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view showing the overall configuration of an image forming apparatus according to the present invention.

FIG. 2 is a longitudinal sectional view showing a state in which a transfer roller and a transfer material guide member are separated from a photosensitive drum.

FIG. 3 is a longitudinal sectional view showing a state in which a transfer roller is brought into contact with a photosensitive drum to form a transfer nip portion, and a transfer material guide member is brought close to the photosensitive drum.

FIG. 4 is an enlarged view of the vicinity of a transfer roller in FIG.

FIG. 5 is an enlarged view of the vicinity of a transfer roller in FIG.

6 is a diagram viewed transfer roller near the Y ₄ direction in FIG.

FIG. 7 illustrates an operation in Embodiment 1.

FIG. 8 illustrates an operation in Embodiment 1.

FIG. 9 is a diagram illustrating an operation in a conventional example.

FIG. 10 is a diagram illustrating an operation in a conventional example.

[Explanation of symbols]

 201B Photosensitive drum unit 201C Image carrier support member (frame) 203B Guide before transfer (transfer material guide member) 207B Image carrier (photosensitive drum) 211B Positioning hole 211C First regulating surface 211D Second regulating surface 212B Positioning protrusion (protrusion) 217B Transfer member (transfer roller) 218B Transfer holder 219B First positioning part (positioning member) 220B Second positioning part (positioning member) 220C Inclined surface M1 Retreat position M2 Transfer position N1 Release position N2 Guide position T Transfer nip part

Claims (6)

[Claims] 1. A transfer nip portion is formed by bringing a transfer member into contact with an image carrier, and a transfer material is inserted through the transfer nip portion to transfer the toner image formed on the image carrier. An image forming apparatus for transferring to an image carrier, an image carrier supporting member rotatably supporting the image carrier, and a transfer supporting the transfer member rotatably and contacting the transfer member with the image carrier. A transfer holder that can be freely attached and detached at a position and a retracted position that is separated from the image carrier; and the image carrier is linked to movement of the transfer member from the retracted position to the transfer position by the transfer holder. A pre-transfer guide that moves from a release position separated from the guide position to a guide position for guiding a transfer material inserted into the transfer nip portion;
A first positioning portion provided on the image carrier supporting member, the positioning hole being opened on the transfer member side at the retracted position; and the pre-transfer guide having a positioning protrusion which can be inserted into and removed from the positioning hole. A transfer unit that moves from the retracted position to the transfer position of the transfer member by the transfer holder and contacts the first positioning unit to move the pre-transfer guide from the release position. A second positioning portion is provided for moving to the guide position and engaging the positioning protrusion with the positioning hole, wherein one of the first positioning portion and the second positioning portion is engaged with the positioning hole. An image forming apparatus, comprising: an inclined surface for preventing the combined positioning projection from moving. 2. The positioning hole according to claim 1, wherein said positioning hole regulates a position of said positioning projection pressed by said inclined surface when said positioning projection is engaged. The image forming apparatus according to claim 1, further comprising a regulating surface. 3. The image forming apparatus according to claim 1, wherein the positioning hole of the image carrier support member is provided near the transfer nip. 4. The image forming apparatus according to claim 3, wherein the positioning hole of the image carrier support member is provided on the upstream side of the transfer nip portion in the insertion direction of the transfer material. 5. The image forming apparatus according to claim 1, wherein one of the first positioning section and the second positioning section is formed by an elastic member. apparatus. 6. The transfer device according to claim 5, wherein the positioning hole of the image carrier support member, the first positioning portion of the pre-transfer guide, and the second positioning portion of the transfer holder are located near both ends in the longitudinal direction of the transfer member. The image forming apparatus according to claim 1, 2, 3, 4, or 5.