JP6972805B2 - Image holder, image forming unit, image forming device - Google Patents

Description

The present invention relates to an image holder, an image forming unit, and an image forming apparatus.

The electrophotographic photosensitive member described in Patent Document 1 includes a central shaft hole into which a shaft is inserted for rotatably supporting, and a ground plate attached to an inner end surface of a flange for electrical conduction between a drum and a shaft. It is equipped with.

Japanese Unexamined Patent Publication No. 2003-233271

The image holder has a cylindrical base material made of aluminum, a photosensitive layer formed on the outer peripheral surface of the base material, and a pressing portion pressed against the inner peripheral surface of the base material. This pressing portion is formed by bending a part of a metal ground plate. Further, on the ground plate, another pressing portion pressed against the metal shaft member (shaft) constituting the rotating shaft of the image holder is formed by bending the other part of the ground plate.

Here, in order to reduce the cost of the base material, the thickness of the base material may be reduced. Specifically, the thickness may be reduced from 0.7 [mm] to 0.4 [mm]. With this change in the thickness of the base material, the material of the ground plate may be reviewed. By reviewing the material of the grounding plate, if the pressing force of the other pressing part against the shaft member is too strong, the other pressing part will be deformed during durability, and after durability, the grounding resistance between the other pressing part and the shaft member. May exceed the standard value. On the other hand, even if the pressing force of the other pressing portion against the shaft member is too weak, the other pressing portion is deformed during durability, and after the durability, the ground contact resistance between the other pressing portion and the shaft member becomes the reference value. May exceed.

The subject of the present invention is to press a pressing portion with a part of the ground plate bent against a base material having a thickness of 0.4 [mm], and press another pressing portion with a bent other part of the ground plate against a shaft member. In the configuration, the grounding resistance between the other pressing portion after durability and the shaft member is set to 100 [Ω] or less.

The image-bearing body according to claim 1 of the present invention has a cylindrical shape made of aluminum and has a thickness of 0.4 [mm] and is attached to an end portion of the base material to open an opening of the base material. A closing member that is closed and rotatably supported by a metal shaft member, a pressing portion that is pressed against the inner peripheral surface of the base material with a metal plate, and 6.4 [on the outer peripheral surface of the shaft member. N] A ground plate having another pressing portion pressed by a pressing force of 14.0 [N] or less, and a photosensitive layer formed on the outer peripheral surface of the base material are provided, and the other pressing is provided. A conductive member formed of a conductive resin member is attached to the portion, and the other pressing portion is pressed against the shaft member with the conductive member sandwiched between the shaft member and the shaft member. The conductive member is characterized in that, in the shaft member, an end face of the base material facing the axial direction and a contact portion that abuts in the axial direction are formed .

The image holder according to claim 2 of the present invention is the image holder according to claim 1, wherein a conductive member made of a conductive resin material is attached to the other pressing portion, and the other pressing portion is attached. The pressing portion is pressed against the shaft member with the conductive member sandwiched between the shaft member and the conductive member, and is in contact with the shaft member on a cut surface along the central axis of the base material. The contact portion of the base material is characterized by having a linear shape along the axial direction of the base material.

The image holder according to claim 3 of the present invention is the image holder according to claim 2, wherein the contact portion of the conductive member is concavely curved when viewed from the axial direction of the base material. It is characterized by.

The image holder according to claim 4 of the present invention is the image holder according to claim 3, wherein the contact portion has an arc shape along the outer peripheral surface of the shaft member when viewed from the axial direction of the base material. It is characterized by being said to be.

The image holder according to claim 5 of the present invention is the image holder according to any one of claims 1 to 4 , wherein the closing member is formed with a through hole through which the shaft member penetrates. The overlap margin between the contact portion and the end surface of the shaft member in the radial direction of the base material is characterized by being greater than or equal to the difference between the hole diameter of the through hole and the outer diameter of the shaft member.

The image forming unit according to claim 6 of the present invention is characterized by comprising the image holder according to any one of claims 1 to 5 and a charging member for charging the outer peripheral surface of the image holder. And.

The image forming apparatus according to claim 7 of the present invention develops an electrostatic latent image formed by exposing the image forming unit according to claim 6 and the outer peripheral surface of the charged image holder. It is characterized by comprising a transfer member for transferring the toner image formed by the above to a recording medium.

The image forming apparatus according to claim 8 of the present invention includes the image holder according to any one of claims 1 to 5 , a charging member that charges the outer peripheral surface of the image holder, and the charged image holder. It is characterized by comprising a transfer member for transferring a toner image formed by developing an electrostatic latent image formed by exposing the outer peripheral surface of the body to a recording medium.

According to the image holder according to claim 1 of the present invention, the pressing portion obtained by bending a part of the grounding plate is pressed against a base material having a thickness of 0.4 [mm], and the other part of the grounding plate is bent. In the configuration in which the pressing portion of the above is pressed against the shaft member, the grounding resistance between the other pressing portion after durability and the shaft member can be set to 100 [Ω] or less.
Further, according to the image holder according to the first aspect of the present invention, the conductive member and the shaft member are separated from each other as compared with the case where the conductive member is in contact with the shaft member only in the radial direction of the base material. It can be suppressed.

According to the image holder of claim 2 of the present invention, as compared with the case where the pressing portion in contact with the shaft member is a protrusion protruding toward the shaft member side, the other pressing portion after durability and the shaft member It is possible to suppress an increase in ground resistance.

According to the image holder according to claim 3 of the present invention, an increase in ground resistance between the other pressing portion and the shaft member after durability is suppressed as compared with the case where the contact portion in contact with the shaft member is flat. can do.

According to the image holder of claim 4 of the present invention, as compared with the case where the contact portion in contact with the shaft member has an arc shape larger than the outer peripheral surface of the shaft member, the other pressing portion and the shaft member after durability are used. It is possible to suppress an increase in grounding resistance with.

According to the image holder of claim 5 , the conductive member and the shaft member are smaller than the case where the overlap margin between the contact portion and the end face is smaller than the difference between the hole diameter of the through hole and the outer diameter of the shaft member. It is possible to suppress the separation from each other.

According to the image forming unit of claim 6 , the density unevenness of the image on the image holder is compared with the case where the grounding resistance between the other pressing portion and the shaft member after durability is larger than 100 [Ω]. Can be suppressed.

According to the image forming apparatus of claim 7 , the density unevenness of the output image is suppressed as compared with the case where the grounding resistance between the other pressing portion after durability and the shaft member is larger than 100 [Ω]. Can be done.

According to the image forming apparatus of claim 8 of the present invention, the density unevenness of the output image is suppressed as compared with the case where the grounding resistance between the other pressing portion after durability and the shaft member is larger than 100 [Ω]. Can be done.

It is an enlarged sectional view which showed the image holder which concerns on 1st Embodiment of this invention. It is sectional drawing which showed the image holder which concerns on 1st Embodiment of this invention. It is sectional drawing which showed the image holder and the charging apparatus which concerns on 1st Embodiment of this invention. It is sectional drawing which showed the image holder and the developing apparatus which concerns on 1st Embodiment of this invention. It is an exploded perspective view which showed the grounding member and the closing member of the image holding body which concerns on 1st Embodiment of this invention. It is an exploded perspective view which showed the image holder which concerns on 1st Embodiment of this invention. It is explanatory drawing used to explain the evaluation of the image holder which concerns on 1st Embodiment of this invention. It is explanatory drawing used to explain the evaluation of the image holder which concerns on 1st Embodiment of this invention. It is a figure which showed the evaluation result of the image holder which concerns on 1st Embodiment of this invention in a table. (A) (B) (C) It is a process diagram which showed the manufacturing process of the base material which constitutes the image-bearing body which concerns on 1st Embodiment of this invention. (A) (B) It is a process diagram which showed the manufacturing process of the base material which constitutes the image-bearing body which concerns on 1st Embodiment of this invention. It is a perspective view which showed the punch type and the ironing type used for manufacturing the base material which comprises the image holder which concerns on 1st Embodiment of this invention. (A) (B) (C) It is a process diagram which showed the manufacturing process of the base material which constitutes the image-bearing body which concerns on 1st Embodiment of this invention. (A) (B) (C) It is a process diagram which showed the manufacturing process of the base material which constitutes the image-bearing body which concerns on 1st Embodiment of this invention. (A) (B) (C) It is a process diagram which showed the manufacturing process of the base material which constitutes the image-bearing body which concerns on 1st Embodiment of this invention. It is a schematic block diagram which showed the image forming apparatus which concerns on 1st Embodiment of this invention. It is a perspective view which showed the grounding member of the image holding body which concerns on 2nd Embodiment of this invention. It is sectional drawing which showed the image holder which concerns on 2nd Embodiment of this invention. It is sectional drawing which showed the image holder which concerns on 2nd Embodiment of this invention. It is sectional drawing which showed the image holder which concerns on 3rd Embodiment of this invention.

<First Embodiment>
An example of the image holder, the image forming unit, and the image forming apparatus according to the first embodiment of the present invention will be described with reference to FIGS. 1 to 16. The arrow H shown in the figure indicates the device vertical direction (vertical direction), the arrow W indicates the device width direction (horizontal direction), and the arrow D indicates the device depth direction (horizontal direction).

(overall structure)
As shown in FIG. 16, in the image forming apparatus 10 according to the present embodiment, the accommodating portion 14 accommodating the sheet member P as a recording medium and the accommodating portion P accommodating in the accommodating portion 14 are conveyed. A section 16 is provided. Further, the image forming apparatus 10 is provided with an image forming unit 20 that forms an image on the sheet member P conveyed from the accommodating unit 14 by the conveying unit 16, and a control unit 48 that controls each unit.

[Accommodation]
The accommodating portion 14 is provided with an accommodating member 14A that can be pulled out from the apparatus main body 10A of the image forming apparatus 10 toward the front side in the depth direction of the apparatus, and the seat member P is loaded on the accommodating member 14A. Further, the accommodating portion 14 is provided with a delivery roll 14B for delivering the sheet member P loaded on the accommodating member 14A to the transport path 28 constituting the transport unit 16.

[Transport section]
The transport unit 16 is provided with a plurality of transport rolls (reference numerals omitted) for transporting the seat member P along the transport path 28 to which the seat member P is transported.

[Image forming part]
The image forming unit 20 includes four image forming units 18Y, 18M, 18C, 18K of yellow (Y), magenta (M), cyan (C), and black (K), and exposure light to an image holder 26 described later. An exposure device 42 for irradiating the light is provided. In the following description, if it is not necessary to distinguish Y, M, C, and K, Y, M, C, and K may be omitted.

The image forming unit 18 (so-called process cartridge) of each color is detachable from the apparatus main body 10A, respectively. The image forming unit 18 of each color is provided with an image holding body 26 and a charging member 38 for charging the surface of the image holding body 26. Further, the image forming unit 18 is provided with a developing device 36 that develops an electrostatic latent image formed by irradiating the charged image holder 26 with exposure light and visualizes it as a toner image. There is. The details of the charging member 38, the developing device 36, and the image holder 26 will be described later.

Further, the image forming unit 20 includes an endless transfer belt 22 that circulates in the direction of arrow A in the figure, and a primary transfer roll 44 that transfers the toner image formed by the image forming unit 18 of each color to the transfer belt 22. It is prepared. Further, the image forming unit 20 heats and pressurizes the secondary transfer roll 46 that transfers the toner image transferred to the transfer belt 22 to the sheet member P and the sheet member P to which the toner image is transferred to obtain the toner image. Is provided with a fixing device 50 for fixing the toner to the sheet member P. The secondary transfer roll 46 is an example of a transfer member.

(Action of image forming device)
In the image forming apparatus 10, an image is formed as follows.

First, the charging member 38 of each color uniformly negatively charges the surface of the image holder 26 of each color at a predetermined potential. Subsequently, the exposure apparatus 42 irradiates the surface of the charged image holder 26 of each color with exposure light to form an electrostatic latent image. As a result, an electrostatic latent image is formed on the surface of the image holder 26 of each color. Further, the developing device 36 for each color develops this electrostatic latent image and visualizes it as a toner image. Further, the toner images formed on the surface of the image holder 26 of each color are sequentially transferred to the transfer belt 22 by the primary transfer roll 44.

Therefore, the sheet member P sent out from the accommodating member 14A to the transfer path 28 by the delivery roll 14B is sent out to the transfer position T where the transfer belt 22 and the secondary transfer roll 46 are in contact with each other. At the transfer position T, the sheet member P is conveyed between the transfer belt 22 and the secondary transfer roll 46, so that the toner image of the transfer belt 22 is transferred to the sheet member P.

Further, the toner image transferred to the sheet member P is fixed to the sheet member P by the fixing device 50. Then, the sheet member P on which the toner image is fixed is discharged to the outside of the apparatus main body 10A.

(Main part composition)
Next, the structure of the charging member 38, the developing device 36, the image holder 26, and the method of manufacturing the base material 80 constituting the image holder 26 will be described.

[Charging member 38]
As shown in FIG. 3, the charging member 38 is arranged below the image holder 26. The charging member 38 includes a shaft member 92 extending in the depth direction of the device, and an elastic portion 94 having a cylindrical shape and through which the shaft member 92 penetrates. The shaft member 92 is rotatably supported by a support member 98 that forms a part of the housing of the image forming unit 18. Further, the outer peripheral surface of the elastic portion 94 is in contact with the image holder 26. Then, a voltage is applied to the shaft member 92, and the charging member 38 is driven by the rotating image holder 26 to rotate, so that the charging member 38 charges the surface of the image holder 26.

[Developer 36]
As shown in FIG. 4, the developing device 36 is arranged on one side (lower side in the drawing) in the width direction of the device with respect to the image holder 26, holds the developer, and is in contact with the image holder 26. A developing roll 74 in which a developing gap (gap) is formed between the developing rolls 74 is provided. Further, the developing device 36 includes a shaft member 78 constituting the rotating shaft of the developing roll 74 and a pair of adjusting rolls 76.

Further, the shaft member 78 is rotatably supported by the support member 98. Further, the pair of adjusting rolls 76 are attached to the shaft member 78 so as to sandwich the developing roll 74 from the depth direction of the apparatus. The pair of adjusting rolls 76 have the same configuration as each other, and the outer diameter of each adjusting roll 76 is larger than the outer diameter of the developing roll 74.

In this configuration, the outer peripheral surfaces of the pair of adjustment rolls 76 are in contact with the image holder 26, so that a development gap (gap) is formed between the development roll 74 and the image holder 26.

[Image holder 26]
As shown in FIGS. 2 and 6, the image holder 26 has a device depth direction as an axial direction, and includes a cylindrical base material 80 extending in the device depth direction. Further, the image holder 26 has a closing member 82 that is fitted to the front end of the base material 80 in the depth direction of the device to close the opening of the base material 80, and the back side of the base material 80 in the depth direction of the device. It is provided with a closing member 84 that is fitted to the end portion of the base material and closes the opening of the base material 80. Further, the image holder 26 is formed on a shaft member 54 forming a part of the rotation axis of the image holder 26, a grounding member 64 for grounding the image holder 26, and an outer peripheral surface 80B of the base material 80. The photosensitive layer 86 is provided with a photosensitive layer 86 whose properties are changed by being irradiated with light to form an electrostatic latent image.

-Base material 80, photosensitive layer 86-
As an example, the base material 80 is formed in a cylindrical shape using aluminum, and has an outer diameter of 30 [mm], a length of 253 [mm], and a thickness of 0.4 [mm]. The thickness of the base material 80 is described as 0.4 [mm], but the thickness is 0.35 [mm] or more and 0.45 [mm] or less in consideration of manufacturing variations. That is, the "thickness 0.4 [mm] of the base material 80" means a thickness of 0.35 [mm] or more and 0.45 [mm] or less.

As described above, since the thickness of the base material 80 is 0.4 [mm], the mass is lighter and the mass is lighter than that of the conventional base material having a thickness of 0.7 [mm]. , The cost is reduced. In other words, the cost of the image holder 26 is reduced as compared with the case of using a conventional substrate having a thickness of 0.7 [mm].

The photosensitive layer 86 is formed by providing a photosensitive layer containing a charge generating material that is irradiated with light to generate charges on the outer peripheral surface 80B of the base material 80 (see FIG. 2).

− Closing member 82−
The closing member 82 is formed by using a polycarbonate resin as an example, and as shown in FIGS. 2 and 4, a part of the closing member 82 is inserted into the base material 80 to form a base material. It is fitted to the end of 80. In this state, the closing member 82 closes the opening of the base material 80.

Then, the closing member 82 has a contact surface 82B to which the end surface of the base material 80 is abutted in the axial direction of the base material 80 and a contact surface 82B in a state where the closing member 82 is fitted to the end portion of the base material 80. One end is in contact with the base material 80, and the base material 80 has an inner peripheral surface 80A and a facing surface 82C facing the inner peripheral surface 80A. Further, the closing member 82 has a conical surface 82D whose one end is in contact with the facing surface 82C and whose outer diameter gradually decreases, and a through hole 82A through which the shaft member 54 penetrates.

The hole diameter of the through hole 82A is set to 5.2 [mm] as an example. Then, by passing the shaft member 54, which will be described later, through the through hole 82A, the closing member 82 rotates about the shaft member 54. Further, the portion of the inner peripheral surface 80A of the base material 80 facing the facing surface 82C and the facing surface 82C of the closing member 82 are adhered to each other by an adhesive S (for example, a cyanoacrylate adhesive).

Specifically, a part of the closing member 82 is inserted into the base material 80 in a state where the adhesive S is applied to the end side portion of the inner peripheral surface 80A of the base material 80, whereby the closing member The facing surface 82C of the 82 and the inner peripheral surface 80A of the base material 80 are adhered to each other by the adhesive S. Here, the adhesive S is applied to the inner peripheral surface 80A of the base material 80 in a range longer than the length of the facing surface 82C of the closing member 82 from the end of the inner peripheral surface 80A of the base material 80.

-Closing member 84-
The closing member 84 is formed by using a polycarbonate resin as an example, and as shown in FIGS. 2 and 5, a part of the closing member 84 is inserted into the base material 80 to form a base material. It is fitted to the end of 80. In this state, the closing member 84 closes the opening of the base material 80.

The closing member 84 has a contact surface 84B to which the end surface of the base material 80 is abutted in the axial direction of the base material 80 and a contact surface 84B in a state where the closing member 84 is fitted to the end portion of the base material 80. One end is in contact with the base material 80, and the base material 80 has an inner peripheral surface 80A and a facing surface 84C facing the inner peripheral surface 80A. Further, the closing member 84 has one end in contact with the facing surface 84C and is surrounded by a conical surface 84D whose outer diameter gradually decreases and an end edge of the conical surface 84D, and has a circular shape facing the closing member 82 side. It has a circular surface 84E.

Further, the closing member 84 has a protruding portion 84F having a circular cross section extending in the depth direction of the device while projecting to the side opposite to the closing member 82. The portion on the base end side of the protrusion 84F is rotatably supported by a through hole (reference numeral omitted) formed in the support member 98. Further, a gear portion 90 having gear teeth is formed in a portion on the tip end side of the protruding portion 84F. Then, the rotational force from the motor 88 provided in the image forming apparatus 10 is transmitted to the image holder 26 via the gear portion 90.

Further, the closing member 84 is attached to a frame (not shown) of the image forming apparatus 10 (see FIG. 16), and has a through hole 84A through which the shaft member 32 extending in the depth direction of the apparatus penetrates. The hole diameter of the through hole 82A is set to 5.2 [mm] as an example. The tip of the shaft member 32 projects from the closing member 84 into the base material 80. A conical surface 32B whose diameter is gradually reduced and an end surface 32C facing the front side in the device depth direction (axial direction of the base material 80) are formed on the tip end side portion of the shaft member 32. The shaft member 32 constitutes another part of the rotating shaft of the image holder 26, and as an example, a conductive SUM-Ni shaft (a shaft obtained by nickel-plating sulfur free-cutting steel) is used. , The outer diameter is 5 [mm].

Then, by passing the shaft member 32 through the through hole 84A, the closing member 84 rotates about the shaft member 54. Further, the portion of the inner peripheral surface 80A of the base material 80 facing the facing surface 84C and the facing surface 84C of the closing member 84 are adhered to each other by an adhesive S (for example, a cyanoacrylate adhesive).

Specifically, a part of the closing member 84 is inserted into the base material 80 in a state where the adhesive S is applied to the end side portion of the inner peripheral surface 80A of the base material 80, whereby the closing member The facing surface 84C of the 84 and the inner peripheral surface 80A of the base material 80 are adhered to each other by the adhesive S. Here, the adhesive S is applied to the inner peripheral surface 80A of the base material 80 in a range longer than the length of the facing surface 84C of the closing member 84 from the end of the inner peripheral surface 80A of the base material 80.

-Shaft member 54-
As an example, the shaft member 54 shown in FIG. 2 uses a conductive SUM-Ni shaft (a shaft obtained by plating sulfur free-cutting steel with nickel) and has an outer diameter of 5 [mm]. The base end of the shaft member 54 is attached to the support member 98, and the tip of the shaft member 54 projects from the closing member 82 into the base material 80.

Further, the shaft member 54 is arranged coaxially with the shaft member 32 described above. The tip of the shaft member 54 and the tip of the shaft member 32 face each other in the depth direction of the device inside the base material 80.

In this configuration, when the rotational force from the motor 88 is transmitted to the image holder 26 via the gear portion 90, the base material 80, the closing member 82, the closing member 84, and the grounding member 64 described later become the shaft member. It rotates around 32 and 54. Specifically, the base material 80, the closing member 82, the closing member 84, and the grounding member 64 described later rotate around the shaft members 32 and 54 without rotating the shaft members 32 and 54.

-Grounding member 64-
As shown in FIGS. 1, 2, and 5, the grounding member 64 is arranged inside the base material 80 on the closing member 82 side of the closing member 84. The grounding member 64 has a metal plate grounding plate 66 and a pair of resin-made rectangular parallelepiped conductive members 68.

As an example, the ground plate 66 is formed by trimming a SUS304-CSP tempering symbol H (JIS G 4313: 1996) having a thickness of 0.2 [mm] into a predetermined shape and bending it. It has a circular main body portion 66A, a pair of ear portions 66B, and a pair of cut-out portions 66C. The selvage portion 66B is an example of a pressing portion, and the cut-up portion 66C is an example of another pressing portion.

The outer diameter of the main body portion 66A is the same as the outer diameter of the circular surface 84E of the closing member 84, and the main body portion 66A is overlapped with the circular surface 84E of the closing member 84. Then, the grounding member 64 is attached to the closing member 84 by fixing the fixing portion (not shown) of the main body portion 66A to the fixed portion (not shown) of the circular surface 84E. Specifically, the main body 66A is fixed to the circular surface 84E so that the main body 66A does not float from the circular surface 84E.

A pair of selvage portions 66B are provided so as to sandwich the center of the circular main body portion 66A, and each selvage portion 66B closes a portion protruding in the radial direction of the main body portion 66A from the outer peripheral edge of the main body portion 66A. It is formed by bending toward the member 84 side. As a result, the selvage portion 66B is a cantilever portion with the base end bent. The tip (free end) of the selvage portion 66B is pressed against the inner peripheral surface 80A of the base material 80 (see FIG. 2). That is, the selvage portion 66B is a leaf spring whose base end is elastically deformed.

In the present embodiment, the position where the tip of the selvage portion 66B is pressed against the inner peripheral surface 80A of the base material 80 is a position separated from the end portion of the base material 80 by about 3.5 [mm]. Further, the position where the tip of the selvage portion 66B is pressed against the inner peripheral surface 80A of the base material 80 is a position about 18 [mm] away from the image forming region where the toner image is formed on the image holder 26. ..

The selvage portion 66B has a rectangular shape in which an R is formed (rounded) at the corner portion of the tip. The width of the selvage portion 66B (L2 in FIG. 5) is 3 [mm], and the length of the selvage portion 66B (L3 in FIG. 5) is 3.5 [mm].

Here, each selvage portion 66B is pressed against the inner peripheral surface 80A of the base material 80 with a pressing force of 0.5 [N] or more and 5.0 [N] or less. The pressing force of the selvage portion 66B is preferably 1.0 [N] or more and 4.0 [N] or less, and 2.0 [N] or more and 3.0 [N] or less, from the viewpoint of grounding resistance described later. ] The following is more preferable. In this way, by setting the pressing force against the inner peripheral surface 80A of the base material 80 of each selvage portion 66B to 0.5 [N] or more and 5.0 [N] or less, the base material of this portion The roundness of 80 is 40 [μm] or less.

As for the measurement of the pressing force, as shown in FIG. 7, the grounding member 64 is attached to the closing member 84, and the closing member 84 is attached to the jig G with a fixture (not shown). Then, using a push-pull gauge, the force is detected while pressing the tip of the selvage portion 66B against the center line C1 side (arrow F1 side in the figure) of the closing member 84 in increments of 0.1 [mm]. Further, a graph of the amount of movement and the detected force is created, and the selvage portion 66B is pressed against the inner peripheral surface 80A of the base material 80 by the force detected at the position corresponding to the inner peripheral surface 80A of the base material 80. It is the pressing force that is present. That is, the tip of the selvage portion 66B in the free state (state in which no external force is applied) is on the outer side (opposite to the center) in the radial direction of the base material 80A as compared with the inner peripheral surface 80A of the base material 80A. positioned. The pressing force of the selvage portion 66B is the pressing force of one selvage portion 66B.

As shown in FIGS. 1 and 5, a pair of cut-up portions 66C are provided with the center of the circular main body portion 66A interposed therebetween. Each of the cut-and-raised portions 66C is surrounded by the outer peripheral edge of the main body portion 66A and is arranged on the same plane as the main body portion 66A. It is formed by cutting up on the opposite side. As a result, the cut-up portion 66C is a cantilever portion with the base end bent. The cut-up portion 66C is a leaf spring whose base end is elastically deformed.

Specifically, the cut-up portion 66C is in a cantilever state by cutting up the central side of the circular main body portion 66A. Further, when viewed from the device depth direction (plate thickness direction of the main body portion 66A), the facing direction of the pair of cut and raised portions 66C intersects the facing direction of the pair of selvage portions 66B.

The cut-up portion 66C has a rectangular shape in which an R is formed (rounded) at the corner portion of the tip. The width of the cut-up portion 66C (L4 in FIG. 5) is 5 [mm], and the length of the cut-up portion 66C (L5 in FIG. 5) is 7 [mm].

Here, each of the cut-and-raised portions 66C has 6.4 [N] or more 14 on the outer peripheral surface 32A of the shaft member 32 in a state where the conductive member 68 described later is sandwiched between the outer peripheral surface 32A of the shaft member 32. It is pressed with a pressing force of 0.0 [N] or less. The pressing force of the cut-up portion 66C is preferably 8.0 [N] or more and 13.0 [N] or less, preferably 10.0 [N] or more and 12.0 [N] or more, from the viewpoint of grounding resistance described later. [N] The following is more preferable.

As for the measurement of the pressing force, as shown in FIG. 8, the grounding member 64 is attached to the closing member 84, and the closing member 84 is attached to the jig G with a fixture (not shown). Then, using a push-pull gauge, the tip (free end) of the cut-up portion 66C is pulled to the side opposite to the center line C1 side of the closing member 84 (arrow F2 side in the figure) in increments of 0.1 [mm]. While detecting force. Further, a graph of the movement amount and the detected force is created, and the force detected at the position corresponding to the outer peripheral surface 32A of the shaft member 32 is pressed against the outer peripheral surface 32A of the shaft member 32 by the cut-up portion 66C. It is the pressing force that is present. That is, the conductive member 68 attached to the cut-out portion 66C in the free state (state in which no external force is applied) is inside (center) in the radial direction of the base material 80A as compared with the outer peripheral surface 32A of the shaft member 32. Located on the side). The pressing force of the cut-up portion 66C is the pressing force of one cut-up portion 66C.

As shown in FIG. 5, the conductive member 68 is formed in a rectangular parallelepiped shape using a resin material having conductivity. A pair of the conductive members 68 are provided, and the pair of the conductive members 68 are attached to the surfaces of the pair of cut-and-raised portions 66C on the sides facing each other by using a mounting tool (not shown). In this state, the continuity between the conductive member 68 and the raised portion 66C is ensured. Then, as shown in FIG. 1, the pair of conductive members 68 are pressed against (and in contact with each other) the outer peripheral surface 32A of the shaft member 32, respectively.

In this way, by pressing the selvage portion 66B of the grounding member 64 against the inner peripheral surface 80A of the base material 80 and pressing the conductive member 68 of the grounding member 64 against the outer peripheral surface 32A of the shaft member 32, the base material 80 (image). The holding body 26) is grounded.

The "resin material having conductivity" is a resin material having a volume resistivity of 10 ¹⁰ [Ω · cm] or less. In this embodiment, as an example, a polyacetal resin conductive grade (POM EW-02) is used as the “resin material having conductivity”.

[Manufacturing method of base material 80]
Next, a method for manufacturing the base material 80 will be described. The base material 80 is manufactured including an impact process for forming a cylindrical cylindrical material 206 and an ironing process for straightening the cylindrical material 206 to form the base material 80.

-Impact processing-
In the impact processing, a bottomed and cylindrical cylindrical material 206 is formed from the slag 202, which is a mass of aluminum. For impact processing, as shown in FIG. 10A, the concave type 204 containing the slag 202, which is a lump of aluminum, and the slag 202 contained in the concave type 204 are pressed to form the slag 202 into a cylindrical shape. A cylindrical punch type 200 is used. The concave portion 204A of the concave type 204 has a circular shape, and the inner diameter of the concave portion 204A is 32.0 [mm] as an example. The outer diameter of the punch type 200 is set to 30.6 [mm] as an example.

In the impact step, first, the slag 202 is housed in the concave mold 204, and the punch mold 200 is further arranged above the concave mold 204 (see FIG. 10A).

Next, as shown in FIGS. 10B and 10C, the punch mold 200 moves downward to crush and deform the slag 202 housed in the concave mold 204. As a result, the slag 202 is deformed into a bottomed and cylindrical cylindrical member 206 along the peripheral surface of the punch mold 200. As an example, the thickness of the cylindrical material 206 is 0.7 [mm], and the inner diameter is 30.6 [mm].

Next, the punch mold 200 moves upward, and as shown in FIG. 11A, the cylindrical member 106 in close contact with the punch mold 200 separates from the concave mold 104. Further, the cylindrical member 106 is pulled out (demolded) from the punch mold 200 as shown in FIG. 11 (B).

-Squeezing-
The ironing process reduces the thickness of the cylindrical material 206 to correct the shape of the cylindrical material 206. For ironing, as shown in FIG. 12, a punch type 220 inserted into the cylindrical material 206 (see FIG. 11 (B)) from the tip (lower end in the figure) and an inner peripheral surface 206A of the cylindrical material 206 (FIG. 11). A squeeze type 222 that imitates the outer peripheral surface 220A of the punch type 220 (see 11 (B)) is used.

The punch type 220 has a columnar shape extending in the vertical direction (one direction), and as an example, the outer diameter of the punch type 220 is 29.2 [mm]. Further, the ironing type 222 has an annular shape, and as an example, the inner diameter is 30.0 [mm].

In the ironing process, first, as shown in FIG. 13A, the punch mold 220 is inserted into the inside of the cylindrical material 206 from the tip. In FIGS. 13 (A) (B) (C) and 14 (A) (B), the gap between the outer peripheral surface of the punch mold 220 and the inner peripheral surface 206A of the cylindrical material 206 is not shown.

Next, FIGS. 13 (B) (C) and 14 (A) (B) (C) show from the position where the cylindrical member 206 into which the punch mold 220 is inserted is moved above the ironing die 222. As such, it is moved downward and passed through the inside of the ironing die 222. As a result, the ironing die 222 presses the cylindrical member 206 against the punch die 220 to reduce the thickness of the cylindrical member 206, and the inner peripheral surface 206A of the cylindrical member 206 follows the outer peripheral surface 220A of the punch die 220. ..

Next, the cylindrical member 206 is pulled out (demolded) from the punch mold 220 as shown in FIGS. 15 (A) and 15 (B). Further, the lower end of the cylindrical material 206 is cut off, and as shown in FIG. 15C, a cylindrical base material 80 having both ends open is formed.

(Action of main part composition)
Next, the operation of the main part configuration will be described.

The motor 88 shown in FIG. 3 rotates the image holder 26. As the image holder 26 rotates, the charging member 38 is driven by the image holder 26 to rotate. Further, a voltage is applied to the shaft member 54 of the charging member 38 from a power source (not shown).

Further, as shown in FIGS. 1 and 2, the base material 80 constituting the image holder 26 is electrically connected to the shaft member 32 via the grounding member 64, so that the image holder 26 is grounded. ing. Therefore, a current flows between the charging member 38 and the image holder 26, and the surface of the image holder 26 is uniformly charged. Then, an electrostatic latent image is formed on the surface of the charged image holder 26 by irradiation with exposure light by the exposure apparatus 42 (see FIG. 17).

Further, the electrostatic latent image formed on the image holder 26 is visualized as a toner image by the developing device 36 shown in FIG. Specifically, when the outer peripheral surfaces of the pair of adjustment rolls 76 of the developing device 36 are in contact with the image holding body 26, a developing gap (gap) is created between the developing roll 74 of the developing device 36 and the image holding body 26. It is formed. Then, the toner is passed to the electrostatic latent image from this development gap, and the electrostatic latent image is visualized as a toner image.

(evaluation)
Next, the evaluation performed on the image holder 26 according to the embodiment of the first embodiment and the image holder according to the comparative example will be described.

[Each configuration]
First, the configurations of Examples 1 and 2 and Comparative Examples 1 and 2 will be described with reference to the table shown in FIG. Items not described below have the same configuration among the members.

Example 1: A base material 80 having a thickness of 0.35 [mm] was used for the image holder 26 of Example 1.

That is, when the base material 80 having a thickness of 0.4 [mm] was used, the base material 80 having a thickness of 0.35 [mm], which is the thinnest in consideration of manufacturing variations, was used. Further, the pressing force of the selvage portion 66B against the inner peripheral surface 80A of the base material 80 is 5.0 [N], and the pressing force of the cut-up portion 66C against the outer peripheral surface 32A of the shaft member 32 is 14.0 [N]. ], A grounding member 64 was used.

Example 2: As the image holder 26 of Example 2, a base material 80 having a thickness of 0.35 [mm] was used. Further, the pressing force of the selvage portion 66B against the inner peripheral surface 80A of the base material 80 is 0.5 [N], and the pressing force of the cut-up portion 66C against the outer peripheral surface 32A of the shaft member 32 is 6.4 [N]. ], A grounding member 64 was used.

Comparative Example 1: A base material 80 having a thickness of 0.35 [mm] was used for the image holder 26 of Comparative Example 1. Further, a ground contact member having a pressing force of the selvage portion 66B against the inner peripheral surface 80A of the base material 80 of 6.0 [N] was used. Further, the pressing force of the selvage portion 66B against the inner peripheral surface 80A of the base material 80 is 5.0 [N], and the pressing force of the cut-up portion 66C against the outer peripheral surface 32A of the shaft member 32 is 15.5 [N]. ], A grounding member 64 was used.

Comparative Example 2: A base material 80 having a thickness of 0.35 [mm] was used for the image holder 26 of Comparative Example 2. Further, a ground contact member having a pressing force of the selvage portion 66B against the inner peripheral surface 80A of the base material 80 of 0.3 [N] was used. Further, the pressing force of the selvage portion 66B against the inner peripheral surface 80A of the base material 80 is 0.5 [N], and the pressing force of the cut-up portion 66C against the outer peripheral surface 32A of the shaft member 32 is 4.8. The grounding member 64 to be [N] was used.

〔Evaluation item〕
Evaluation of substrate deformation: Roundness of the outer peripheral surface of the substrate at the portion where the tip (free end) of the selvage 66B is pressed against the image holders of Examples 1 and 2, Comparative Examples 1 and 2. (JIS B 0419) was measured. The roundness of the base material before attaching the closing member 84 was 11 [μm] or more and 14 [μm] or less. When the roundness was 40 [μm] or less, the substrate deformation evaluation was set to “◯”. Further, when the roundness was larger than 40 [μm], the substrate deformation evaluation was set to “x”.

Considering the past results, when the roundness is 40 [μm] or less at the site measured this time, the density unevenness of the output image caused by the roundness of the image forming region of the base material 80 is It is an acceptable level in terms of commercial value. The roundness was measured using a roundness measuring device Rondocom (manufactured by Tokyo Seimitsu Co., Ltd.).

-Evaluation of ground resistance (between the selvage and the base material): A voltage of 10 [V] was applied between the base 80 and the selvage 66B of the ground plate 66, and the resistance value [Ω] was measured. When the resistance value was 100 [Ω] or less, the ground resistance evaluation was set to “◯”. When the resistance value was larger than 100 [Ω], the ground resistance evaluation was set to “x”.

Considering the past results, it is assumed that the continuity between the cut-out portion 66C of the ground plate 66 and the shaft member 32 is secured, and if this resistance value is 100 [Ω] or less, it is caused by uneven charging. The density unevenness of the output image caused by the above is an acceptable level in terms of commerciality.
-Evaluation of grounding resistance before durability (between the cut-out portion and the shaft member): The image holders of Examples 1 and 2 and Comparative Examples 1 and 2 are attached to the Docu Print C1100 manufactured by Fuji Xerox Co., Ltd., respectively, and an image forming operation is performed. A voltage of 10 [V] was applied between the cut-up portion 66C and the shaft member 54, and the resistance value [Ω] was measured.

-Evaluation of grounding resistance after durability (between the cut-out portion and the shaft member): The image holders of Examples 1 and 2 and Comparative Examples 1 and 2 are attached to Docu Print C1100 manufactured by Fuji Xerox Co., Ltd., respectively, and are of A4 size. A black halftone image was formed on 10,000 sheet members P and output. After that, a voltage of 10 [V] was applied between the cut-up portion 66C and the shaft member 54, and the resistance value [Ω] was measured.

As described above, when the resistance value is 100 [Ω] or less, the ground resistance evaluation is set to “◯”. When the resistance value was larger than 100 [Ω], the ground resistance evaluation was set to “x”. Considering the past results, if the resistance value is 100 [Ω] or less on the premise that the conduction between the selvage portion 66B of the ground plate 66 and the base material 80 is secured, the output caused by the uneven charging is generated. The density unevenness of the image is an acceptable level in terms of commerciality.

〔Evaluation results〕
Regarding the substrate deformation evaluation, the roundness was 35 [μm] in the case of Example 1, the roundness was 24 [μm] in the case of Example 2, and the roundness was 20 [μm] in the case of Comparative Example 2. μm], it was "○". On the other hand, in the case of Comparative Example 1, the roundness was 46 [μm] and it was “x”. It is considered that the base material 80 is deformed because the pressing force of the selvage portion 66B against the inner peripheral surface 80A of the base material 80 is larger than 5.0 [N].

Regarding the grounding resistance evaluation, it was 70 [Ω] in the case of Example 1, 90 [Ω] in the case of Example 2, and 60 [Ω] in the case of Comparative Example 1, which was “◯”. On the other hand, in the case of Comparative Example 2, it was 115 [Ω], which was “x”. This is because the pressing force of the selvage portion 66B against the inner peripheral surface 80A of the base material 80 is smaller than 0.5 [N]. Therefore, the adhesive S applied to the inner peripheral surface 80A of the base material 80 for attaching the closing member 84 to the base material 80 remains between the tip of the selvage portion 66B and the inner peripheral surface 80A of the base material 80. , It is considered that the flow of electricity was obstructed by this adhesive S.

Regarding the evaluation of the ground resistance before endurance, "○" was given for Examples 1 and 2 and Comparative Examples 1 and 2.

On the other hand, the evaluation of the ground resistance after durability was 100 [Ω] in the case of Example 1 and 80 [Ω] in the case of Example 2, which was “◯”. On the other hand, in the case of Comparative Example 1, it was 120 [Ω], and in the case of Comparative Example 2, it was 110 [Ω], which was “x”.

In Comparative Example 1, since the pressing force of the cut-up portion 66C is stronger than 14.0 [N], the cut-up portion 66C is moved in the circumferential direction due to the frictional force generated between the conductive member 68 and the shaft member 32. It is considered that it has been deformed and the ground resistance evaluation has become "x".

Further, in Comparative Example 2, since the pressing force of the cut-up portion 66C is weaker than 6.4 [N], the cut-up portion 66C is deformed in the radial direction due to the vibration generated in the cut-up portion 66C during durability. I think that the ground resistance evaluation became "x".

(summary)
As can be seen from the above evaluation results, in the present embodiment, the cut-up portion 66C is pressed against the outer peripheral surface 32A of the shaft member 32 with a pressing force of 6.4 [N] or more and 14.0 [N] or less. ing. Therefore, the ground resistance between the cut-up portion 66C and the shaft member 32 after durability is 100 [Ω] or less.

In the image forming unit 18, the cut-up portion 66C has a grounding resistance of 100 [Ω] or less between the cut-up portion 66C and the shaft member 32 after durability, so that the toner on the image holder 26 after durability is reached. Image density unevenness is suppressed.

In the image forming apparatus 10, the cut-up portion 66C has a grounding resistance of 100 [Ω] or less between the cut-up portion 66C and the shaft member 32 after durability, so that uneven density of the output image after durability is suppressed. Will be done.

<Second Embodiment>
An example of the image holder, the image forming unit, and the image forming apparatus according to the second embodiment of the present invention will be described with reference to FIGS. 17 to 19. In addition, about the 2nd Embodiment, the part different from the 1st Embodiment will be mainly described.

In the conductive member 268 of the image holder 226 of the second embodiment, the contact portion 268A in contact with the outer peripheral surface 32A of the shaft member 32 is curved in a concave shape as shown in FIGS. 17 and 19.

Specifically, on the cut surface along the central axis of the base material 80, the contact portion 268A is formed into a linear shape along the axial direction (device depth direction) of the base material 80 as shown in FIG. There is. Further, on the cut surface orthogonal to the central axis of the base material 80 (viewed from the axial direction of the base material 80), the contact portion 268A is curved in a concave shape as shown in FIG. Further, the contact portion 268A has an arc shape along the outer peripheral surface 32A of the shaft member 32.

As described above, on the cut surface along the central axis of the base material 80, the contact portion 268A has a linear shape along the axial direction of the base material 80, so that the contact portion protrudes toward the shaft member 32. The posture of the conductive member 268 with respect to the shaft member 32 is more stable than in the case of. As a result, in the image holder 226, an increase in ground resistance after durability is suppressed as compared with the case where the contact portion is a protrusion protruding toward the shaft member 32 side.

Further, since the contact portion 268A of the conductive member 268 is curved in a concave shape on the cut surface orthogonal to the central axis of the base material 80, the conductive portion is conductive to the shaft member 32 as compared with the case where the contact portion is flat. The posture of the member 268 is stable. As a result, in the image holder 226, an increase in grounding resistance after durability is suppressed as compared with the case where the contact portion is flat.

Further, the contact portion 268A of the conductive member 268 has an arc shape along the outer peripheral surface 32A of the shaft member 32. Therefore, the posture of the conductive member 268 with respect to the shaft member 32 is more stable than in the case where the contact portion 268A of the conductive member 268 has an arc shape larger than the outer peripheral surface 32A of the shaft member 32. As a result, in the image holder 226, an increase in ground resistance after durability is suppressed as compared with the case where the contact portion 268A of the conductive member 268 has an arc shape larger than the outer peripheral surface 32A of the shaft member 32.

Here, "the contact portion 268A has an arc shape along the outer peripheral surface 32A of the shaft member 32" means that 80% or more of the contact portion 268A is viewed from the central axial direction (device depth direction) of the base material 80. , It is in contact with the outer peripheral surface 32A of the shaft member 32. It should be noted that the contacting situation can be determined by irradiating light from the opposite side to be visually inspected and confirming the leakage of light.

The other actions of the second embodiment are the same as those of the first embodiment.

<Third Embodiment>
An example of the image holder, the image forming unit, and the image forming apparatus according to the third embodiment of the present invention will be described with reference to FIG. In addition, about the 3rd Embodiment, the part different from the 2nd Embodiment will be mainly described.

The conductive member 368 of the image holder 326 of the third embodiment has a contact portion 368A in contact with the outer peripheral surface 32A of the shaft member 32, a contact portion 368B in contact with the end surface 32C of the shaft member 32 in the depth direction of the device, and a contact portion 368A. A connecting portion 368C that connects the contact portion 368B and the contact portion 368B is formed. The contact portion 368A is formed in the same shape as the contact portion 268A of the conductive member 268 of the second embodiment. The connecting portion 368C extends from the portion of the contact portion 368A on the front side in the device depth direction to the front side in the device depth direction.

The contact portion 368B extends from the tip of the connecting portion 368C to the central axis (central axis of the shaft member 32) side of the base material 80. Further, the tip of one contact portion 368B faces the tip of the other contact portion 368B in the radial direction of the base material 80. Each of the contact portions 368B is in contact with the end surface 32C of the shaft member 32 in the axial direction (device depth direction) of the base material 80.

Further, the overlap margin (L6 in the figure) between the contact portion 368B and the end face 32C in the radial direction of the base material 80 is equal to or greater than the difference between the hole diameter of the through hole 84A of the closing member 84 and the outer diameter of the shaft member 32. Has been done. The overlapping allowance L6 is measured in a state where the overlapping allowance L6 is moved to one side in the radial direction so as to increase the overlapping allowance L6 and a state where the overlapping allowance L6 is moved to the other side so as to decrease. Then, the average value is set as the overlap allowance L6.

In the present embodiment, the overlapping allowance is 1.5 [mm], the hole diameter of the through hole 84A is 5.2 [mm], and the outer diameter of the shaft member 32 is 5.0 [mm]. The hole diameter of the through hole 84A and the outer diameter of the shaft member 32 can be measured with a micro caliper or the like.

In this way, the contact portion 368B is in contact with the shaft member 32 in the axial direction of the base material 80. Therefore, the image holder 26 vibrates in the radial direction of the base material 80 by operating the image holder 26, as compared with the case where the conductive member is in contact with the shaft member 32 only in the radial direction of the base material 80. Even when this is done, the distance between the conductive member 368 and the shaft member 32 is suppressed.

Further, the overlap margin L6 between the contact portion 368B and the end surface 32C is equal to or larger than the difference between the hole diameter of the through hole 84A and the outer diameter of the shaft member 32. Therefore, even when the image holder 26 vibrates in the radial direction of the base material 80, the conductive member is smaller than the case where the overlap margin L6 is smaller than the difference between the hole diameter of the through hole 84A and the outer diameter of the shaft member 32. It is suppressed that the 368 and the shaft member 32 are separated from each other. Further, the other actions of the third embodiment are the same as those of the first embodiment.

Although the present invention has been described in detail with respect to specific embodiments, the present invention is not limited to such embodiments, and various other embodiments can be taken within the scope of the present invention. That is clear to those skilled in the art. For example, in the above embodiment, two cut-and-raised portions 66C are formed on the grounding member 64, but the number may be one or three or more. In the case of a plurality of pieces, the contact with the shaft member 32 is stabilized by arranging them at the same intervals (pitch) in the circumferential direction of the base material 80.

Further, the contact portion 368A of the conductive member 368 of the third embodiment is formed to have the same shape as the contact portion 268A of the conductive member 268 of the second embodiment, but may not have the same shape. .. In this case, the contact portion 368A does not have the same shape as the contact portion 268A of the conductive member 268 of the second embodiment.

10 Image forming device 18 Image forming unit 26 Image holding body 32 Shaft member 32A Outer peripheral surface 32C End surface 36 Developing device 38 Charging member 46 Secondary transfer roll (example of transfer member)
66 Ground plate 66B Ear part (example of pressing part)
66C cut-up part (an example of another pressing part)
68 Conductive member 80 Base material 80A Inner peripheral surface 84 Closure member 84A Through hole 86 Photosensitive layer 226 Image holder 268 Conductive member 268A Contact part 326 Image holder 368 Conductive member 368A Contact part 368B Contact part

Claims (8)

A cylindrical aluminum base material with a thickness of 0.4 [mm] and
A closing member attached to the end of the base material to close the opening of the base material and rotatably supported by a metal shaft member.
A metal plate that is pressed against the inner peripheral surface of the base material and the outer peripheral surface of the shaft member with a pressing force of 6.4 [N] or more and 14.0 [N] or less. With a grounding plate having a pressing part of
A photosensitive layer formed on the outer peripheral surface of the base material is provided.
A conductive member made of a conductive resin member is attached to the other pressing portion.
The other pressing portion is pressed against the shaft member with the conductive member sandwiched between the shaft member and the shaft member.
An image holder in which an end face of the shaft member facing the axial direction and a contact portion that abuts in the axial direction are formed on the conductive member . A conductive member made of a conductive resin material is attached to the other pressing portion.
The other pressing portion is pressed against the shaft member with the conductive member sandwiched between the shaft member and the shaft member.
The image according to claim 1, wherein in the cut surface along the central axis of the base material, the contact portion of the conductive member in contact with the shaft member is linear along the axial direction of the base material. Reservoir. The image holder according to claim 2, wherein the contact portion of the conductive member is curved in a concave shape when viewed from the axial direction of the base material. The image holder according to claim 3, wherein the contact portion has an arc shape along the outer peripheral surface of the shaft member when viewed from the axial direction of the base material. The closing member is formed with a through hole through which the shaft member penetrates.
Any one of claims 1 to 4 , wherein the overlap margin between the contact portion and the end surface of the shaft member in the radial direction of the base material is equal to or greater than the difference between the hole diameter of the through hole and the outer diameter of the shaft member. The image holder described in the section. The image holder according to any one of claims 1 to 5.
A charging member that charges the outer peripheral surface of the image holder, and
An image forming unit comprising. The image forming unit according to claim 6 and
A transfer member that transfers a toner image formed by developing an electrostatic latent image formed by exposing the outer peripheral surface of the charged image holder to a recording medium, and a transfer member.
An image forming apparatus. The image holder according to any one of claims 1 to 5.
A charging member that charges the outer peripheral surface of the image holder, and
A transfer member that transfers a toner image formed by developing an electrostatic latent image formed by exposing the outer peripheral surface of the charged image holder to a recording medium, and a transfer member.
An image forming apparatus.

Images