JP2019040156A - Image holding body, image forming unit, and image forming apparatus - Google Patents

Abstract

To obtain an image holding body that is configured such that metallic springs are pressed against an inner peripheral surface of a substrate, and can reduce a variation between springs in pressing force for pressing the spring against the inner peripheral surface of the substrate, compared with the case where a free end of a portion bent as a leaf spring is pressed against the inner peripheral surface of the substrate; and an image forming apparatus.SOLUTION: A ground spring 64 is pressed against an inner peripheral surface 80A of a substrate 80 at a curved part 68C by a coil spring 66 mainly being elastically deformed. This reduces a variation between springs in pressing force for pressing the spring against the inner peripheral surface 80A of the substrate 80, compared with the case where a free end of a portion bent as a leaf spring is pressed against the inner peripheral surface of the substrate.SELECTED DRAWING: Figure 1

Description

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

  The photosensitive drum described in Patent Document 1 includes a cylindrical photosensitive member and a flange fitted to the opening end in the axial direction thereof, and is rotatably supported by a shaft inserted through the flange and fixed to the flange. The ground terminal of the leaf spring is configured to be in sliding contact with the shaft.

JP 2013-011709 A

  The image carrier has a metallic cylindrical base, a photosensitive layer formed on the outer peripheral surface of the base, and a metal spring for grounding the image carrier. This spring is a cantilevered plate spring formed by bending a portion protruding from a plate-shaped main body.

  Specifically, the base end of the leaf spring is mainly elastically deformed, and the free end of the bent portion is pressed against the inner peripheral surface of the substrate to electrically connect the leaf spring and the substrate. As described above, the base end of the bent portion is mainly deformed elastically in the leaf spring. For this reason, the volume of the elastically deformed portion is small. Thus, since the volume of the elastically deformed portion of the leaf spring is small, the pressing force with which the free end of the bent portion is pressed against the inner peripheral surface of the base material varies between components.

  The problem of the present invention is that the metal spring is pressed against the inner peripheral surface of the base material, compared with the case where the free end of the bent portion like a leaf spring is pressed against the inner peripheral surface of the base material. It is suppressing that the pressing force which presses to the inner peripheral surface of a base material varies between components.

  An image carrier according to claim 1 of the present invention includes a metal cylindrical base material, a photosensitive layer formed on an outer peripheral surface of the base material, and a coiled coil portion. And a metal spring that is pressed against the inner peripheral surface and electrically connected to a grounded conductive member.

  An image carrier according to a second aspect of the present invention is the image carrier according to the first aspect, wherein the spring protrudes from the coil portion and one end of the coil portion and is pressed against the inner peripheral surface. And the protrusion extends in one direction when viewed from the axial direction of the substrate, and the protrusion extends along the axis of the substrate when viewed from the one direction. It is characterized by.

  The image carrier according to claim 3 of the present invention is the image carrier according to claim 2, wherein a portion of the protrusion that is pressed against the inner peripheral surface of the base material is curved. .

  An image carrier according to a fourth aspect of the present invention is the image carrier according to the third aspect, wherein the protruding portion has a curved portion bent so that the inner peripheral surface side of the base material is convex. The curved portion is pressed against the inner peripheral surface of the base material.

  An image carrier according to a fifth aspect of the present invention is the image carrier according to any one of the second to fourth aspects, wherein the torsion spring projects from the other end of the coil portion. It has a protrusion part, The said other protrusion part is pressed on the metal shaft member as said electroconductive member while comprising the rotating shaft of the said base material, It is characterized by the above-mentioned.

  An image carrier according to a sixth aspect of the present invention is the image carrier according to the fifth aspect, wherein the torsion spring rotates integrally with a shaft member, and the other is seen from the axial direction of the base material. The protruding portion extends in the radial direction of the shaft member.

  The image carrier according to claim 7 of the present invention is the image carrier according to claim 5 or 6, wherein a portion of the other protrusion that is pressed against the outer peripheral surface of the shaft member is curved. It is characterized by.

  An image carrier according to an eighth aspect of the present invention is the image carrier according to the seventh aspect, wherein the other protruding portion is another curved portion bent so that the outer peripheral surface side of the shaft member is convex. The other curved portion is pressed against the outer peripheral surface of the shaft member.

  An image carrier according to a ninth aspect of the present invention is the image carrier according to the fifth aspect, wherein the torsion spring rotates relative to a shaft member, and is viewed from the axial direction of the substrate. The other protrusion is characterized by extending in the tangential direction of the contact point in contact with the shaft member.

  The image holding body according to claim 10 of the present invention is the image holding body according to any one of claims 5 to 9, wherein the coil portion includes a first coil portion from which the protruding portion protrudes, and the coil portion; It has the 2nd coil part which has the said other protrusion part protruded while it is connected with the 1st coil part, It is characterized by the above-mentioned.

  An image carrier according to an eleventh aspect of the present invention is the image carrier according to the tenth aspect, wherein an axial direction of the first coil portion and an axial direction of the second coil portion are different. Yes.

  An image forming unit according to a twelfth aspect of the present invention includes the image carrier according to any one of the first to eleventh aspects, and a charging member that charges an outer peripheral surface of the image carrier. It is said.

  An image forming apparatus according to a thirteenth aspect of the present invention develops an electrostatic latent image formed by exposing the outer peripheral surface of the image forming unit according to the twelfth aspect and the charged image carrier as a toner image. And a transfer member that transfers the toner image formed on the outer peripheral surface of the image carrier to a recording medium.

  According to a fourteenth aspect of the present invention, there is provided an image forming apparatus according to any one of the first to eleventh aspects, a charging member for charging an outer peripheral surface of the image holding body, and the charged image holding member. A developing device that develops an electrostatic latent image formed by exposing the outer peripheral surface of the body as a toner image, and a transfer member that transfers the toner image formed on the outer peripheral surface of the image carrier to a recording medium. It is characterized by providing.

  According to the image carrier of claim 1 of the present invention, in the configuration in which the metal spring is pressed against the inner peripheral surface of the base material, the free end of the portion bent like a leaf spring is placed on the inner peripheral surface of the base material. Compared with the case where it presses, it can suppress that the pressing force which presses a spring against the internal peripheral surface of a base material varies between components.

  According to the image carrier of claim 2 of the present invention, the protrusion extends in one direction when viewed from the axial direction of the substrate, and the protrusion is inclined with respect to the axis when viewed from this one direction. As compared with the above, it is possible to suppress the pressing force pressing the spring against the inner peripheral surface of the base material from being dispersed between the parts.

  According to the image carrier of the third aspect of the present invention, it is possible to suppress the scratch on the inner peripheral surface of the base material as compared with the case where the corner portion is pressed against the inner peripheral surface of the base material.

  According to the image carrier of claim 4 of the present invention, the curved portion can be formed without using a polishing machine.

  According to the image holding body of the fifth aspect of the present invention, the base member and the shaft member can be electrically connected only by the torsion spring.

  According to the image carrier of claim 6 of the present invention, the spring is provided with the shaft member as compared with the case where the other protrusions are inclined with respect to the radial direction of the shaft member when viewed from the axial direction of the substrate. It is possible to suppress the pressing force that is pressed against the outer peripheral surface of each of the parts from being dispersed among the parts.

  According to the image holding body of the seventh aspect of the present invention, it is possible to suppress the outer peripheral surface of the shaft member from being damaged as compared with the case where the corner portion is pressed against the outer peripheral surface of the shaft member.

  According to the image holding member of the eighth aspect of the present invention, another curved portion can be formed without using a polishing machine.

  According to the image holding body of the ninth aspect of the present invention, when viewed from the axial direction of the base material, the other protrusions are periodic as compared with the case where the other protrusions extend in the radial direction of the shaft member. Can be prevented from being deformed.

  According to the image carrier of claim 10 of the present invention, the pressing force of the spring against the inner peripheral surface of the base material and the pressing force of the spring against the outer peripheral surface of the shaft member can be set individually.

  According to the image holding body of the eleventh aspect of the present invention, the pressing direction for pressing the other protruding portion against the outer peripheral surface of the shaft member is determined without being restricted by the pressing direction for pressing the protruding portion against the inner peripheral surface of the base member. be able to.

  According to the image forming unit of the twelfth aspect of the present invention, compared to the case where the image holding body that presses the free end of the bent portion like the leaf spring is pressed against the inner peripheral surface of the base material, The density unevenness of the toner image can be suppressed.

  According to the image forming apparatus of the thirteenth aspect of the present invention, the density of the output image is compared with the case where the image holding body that presses the free end of the bent portion like the leaf spring is pressed against the inner peripheral surface of the substrate. Unevenness can be suppressed.

  According to the image forming apparatus of the fourteenth aspect of the present invention, the density unevenness of the output image is suppressed as compared with the case where the image holding body that presses the free end of the bent portion like the leaf spring is pressed against the inner peripheral surface. can do.

It is sectional drawing which showed the image holding body which concerns on 1st Embodiment of this invention. (A) (B) It is sectional drawing which showed the image holding body which concerns on 1st Embodiment of this invention. It is the perspective view which showed the closure member etc. of the image holding body which concerns on 1st Embodiment of this invention. 1 is an exploded perspective view showing an image carrier according to a first embodiment of the present invention. 1 is a side view illustrating an image carrier and a charging device according to a first embodiment of the present invention. 1 is a plan view showing an image carrier and a developing device according to a first embodiment of the present invention. 1 is a schematic configuration diagram illustrating an image forming apparatus according to a first embodiment of the present invention. (A) (B) (C) It is process drawing which showed the manufacturing process of the base material which comprises the image holding body which concerns on 1st Embodiment of this invention. (A) (B) It is process drawing which showed the manufacturing process of the base material which comprises the image holding body which concerns on 1st Embodiment of this invention. It is the perspective view which showed the punch type | mold and ironing type | mold used for manufacturing the base material which comprises the image holding body which concerns on 1st Embodiment of this invention. (A) (B) (C) It is process drawing which showed the manufacturing process of the base material which comprises the image holding body which concerns on 1st Embodiment of this invention. (A) (B) (C) It is process drawing which showed the manufacturing process of the base material which comprises the image holding body which concerns on 1st Embodiment of this invention. (A) (B) (C) It is process drawing which showed the manufacturing process of the base material which comprises the image holding body which concerns on 1st Embodiment of this invention. It is sectional drawing which showed the image holding body which concerns on the comparison form with respect to 1st Embodiment of this invention. It is the perspective view which showed the obstruction | occlusion member of the image holding body which concerns on the comparison form with respect to 1st Embodiment of this invention, and a grounding member. It is an expanded sectional view showing an image carrier concerning a comparison form with respect to a 1st embodiment of the present invention. It is sectional drawing which showed the image holding body which concerns on 2nd Embodiment of this invention. (A) (B) It is sectional drawing which showed the image holding body which concerns on 2nd Embodiment of this invention. It is the perspective view which showed the obstruction | occlusion member etc. of the image holding body which concerns on 2nd Embodiment of this invention.

<First Embodiment>
An example of the image carrier, 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. In the drawing, an arrow H indicates the vertical direction of the apparatus (vertical direction), an arrow W indicates the apparatus width direction (horizontal direction), and an arrow D indicates the depth direction of the apparatus (horizontal direction).

(overall structure)
As illustrated in FIG. 7, the image forming apparatus 10 according to the present exemplary embodiment includes a storage unit 14 that stores a sheet member P as a recording medium, and a transport that transports the sheet member P stored in the storage unit 14. Part 16 is provided. Further, the image forming apparatus 10 includes an image forming unit 20 that forms an image on the sheet member P conveyed from the storage unit 14 by the conveying unit 16, and a control unit 48 that controls each unit.

[Container]
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 apparatus depth direction, and the sheet member P is stacked on the accommodating member 14A. Further, the accommodating portion 14 is provided with a sending roll 14 </ b> B that sends the uppermost sheet member P stacked on the accommodating member 14 </ b> A to the conveying path 28 constituting the conveying portion 16.

[Transport section]
The transport unit 16 includes a plurality of transport rolls (reference numerals omitted) that transport the sheet member P along the transport path 28 along which the sheet member P is transported.

(Image forming part)
The image forming unit 20 includes four image forming units 18Y, 18M, 18C, and 18K of yellow (Y), magenta (M), cyan (C), and black (K), and an exposure light to an image carrier 26 described later. And an exposure device 42 for irradiating. In the following description, Y, M, C, and K may be omitted when there is no need to distinguish between Y, M, C, and K.

  Each color image forming unit 18 (process cartridge) is detachable from the apparatus main body 10A. Each color image forming unit 18 includes an image carrier 26 and a charging member 38 that charges the outer peripheral surface of the image carrier 26. Further, the image forming unit 18 is provided with a developing device 36 that develops the electrostatic latent image formed by irradiating the charged image carrier 26 with exposure light from the exposure device 42 and visualizes it as a toner image. Yes. Details of the image carrier 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. Is provided. Further, the image forming unit 20 heats and presses 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, and thereby the toner image. Is fixed to the sheet member P.

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

  First, each color charging member 38 uniformly negatively charges the outer peripheral surface of each color image carrier 26 with a predetermined potential. Further, the exposure device 42 irradiates the outer peripheral surface of the charged image carrier 26 with exposure light to form an electrostatic latent image. As a result, an electrostatic latent image is formed on the outer peripheral surface of each color image carrier 26. Further, each color developing device 36 develops the electrostatic latent image and visualizes it as a toner image. In addition, the toner images formed on the outer peripheral surface of each color image holding body 26 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 transport path 28 by the sending roll 14B is sent out to the transfer position T where the transfer belt 22 and the secondary transfer roll 46 come into contact. At the transfer position T, the sheet member P is conveyed between the transfer belt 22 and the secondary transfer roll 46, whereby the toner image on 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 configuration)
Next, a method for manufacturing the charging member 38, the developing device 36, the image carrier 26, and the substrate 80 constituting the image carrier 26 will be described.

[Charging member 38]
As shown in FIG. 5, the charging member 38 is disposed below the image carrier 26. The charging member 38 includes a shaft member 92 extending in the apparatus depth direction and a cylindrical elastic portion 94 through which the shaft member 92 passes. The shaft member 92 is rotatably supported by a support member 98 that forms a part of the casing of the image forming unit 18. Further, the outer peripheral surface of the elastic portion 94 is in contact with the image carrier 26.

  In this configuration, when a voltage is applied to the shaft member 92 and the charging member 38 rotates following the rotating image carrier 26, the charging member 38 charges the outer peripheral surface of the image carrier 26.

[Developing device 36]
As shown in FIG. 6, the developing device 36 is disposed on one side (lower side in the figure) in the apparatus width direction with respect to the image holding body 26, holds the developer, and is connected to the image holding body 26. A developing roll 74 having a developing gap (gap) therebetween is provided. Further, the developing device 36 includes a shaft member 78 that constitutes a rotating shaft of the developing roll 74 and a pair of adjusting rolls 76. The developing device 36 is an example of a developing member.

  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 apparatus depth direction. The pair of adjustment rolls 76 have the same configuration, and the outer diameter of each adjustment 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 carrier 26, so that a development gap (gap) is formed between the development roller 74 and the image carrier 26.

[Image carrier 26]
As shown in FIGS. 1 and 4, the image holding body 26 includes a cylindrical base material 80 that has the apparatus depth direction as an axial direction and extends in the apparatus depth direction. Further, the image holding body 26 is fitted to the near end of the base material 80 in the apparatus depth direction to close the opening of the base material 80, and the base material 80 has the depth side in the apparatus depth direction. And a closing member 84 that closes the opening of the base material 80. In addition, the image carrier 26 is provided on the shaft member 54 constituting the rotation shaft of the image carrier 26, a pair of metal grounding springs 64 for grounding the image carrier 26, and the outer peripheral surface 80 </ b> B of the substrate 80. And a photosensitive layer 86 that is formed and irradiated with light to change its properties to form an electrostatic latent image. The ground spring 64 is an example of a metal spring and a torsion spring.

-Base material 80, photosensitive layer 86-
The base material 80 is formed in a cylindrical shape using aluminum which is a metal, and has an outer diameter of 30 [mm], a length of 253 [mm], and a thickness of 0.4 [mm]. In addition, about the thickness of the base material 80, although described as 0.4 [mm], when manufacturing dispersion | variation was considered, the thickness of the base material 80 is 0.35 [mm] or more and 0.45 [mm] or less It is. That is, the “thickness 0.4 [mm] of the base material 80” means that the thickness of the base material 80 is not less than 0.35 [mm] and not more than 0.45 [mm]. Thus, since the thickness of the base material 80 is 0.4 [mm], for example, compared with a conventional base material with a thickness of 0.7 [mm], the mass is lighter, Cost has been reduced. In other words, the cost of the image carrier 26 is reduced as compared with the case where a base material having a thickness of 0.7 [mm] is used.

  The photosensitive layer 86 is formed by evaporating a material containing an organic photo semiconductor cadmium sulfide whose properties change when irradiated with light on the outer peripheral surface 80B of the substrate 80 (see FIG. 1).

-Occlusion member 82-
The closing member 82 is formed using a polycarbonate resin, and as illustrated in FIG. 1, the closing member 82 has a stepped columnar shape including a plurality of portions having different outer diameter dimensions. A part is inserted into the substrate 80. The blocking member 82 has a through hole 82A through which the shaft member 54 penetrates, a contact surface 82B against which an end surface of the substrate 80 is abutted in the axial direction of the substrate 80, and one end of the contact surface 82B. And an opposed surface 82C facing the inner peripheral surface 80A of the substrate 80. Further, the closing member 82 has a conical surface 82D that is in contact with the opposing surface 82C at one end and gradually decreases in outer diameter.

  The diameter of the through hole 82A is 5 [mm]. Then, the shaft member 54 is passed through the through-hole 82A, and the closing member 82 rotates integrally with the shaft member 54.

  Further, an adhesive (for example, a cyanoacrylate adhesive) is applied to a portion of the substrate 80 that faces the facing surface 82C. Then, the blocking member 82 is attached to the substrate 80 by bonding the facing surface 82C to the substrate 80 with this adhesive.

  In this configuration, a part of the blocking member 82 is inserted into the base member 80 by moving the blocking member 82 in the apparatus depth direction (the axial direction of the base member 80) with respect to the base member 80.

−Occlusion member 84−
The closing member 84 is formed using a polycarbonate resin, and as shown in FIG. 1, the closing member 84 has a stepped columnar shape including a plurality of portions having different outer diameter dimensions. A part is inserted into the substrate 80. The closing member 84 is in contact with the through hole 102 through which the shaft member 54 penetrates, the contact surface 104 against which the end surface of the substrate 80 is abutted in the axial direction of the substrate 80, and one end of the contact surface 104. And an opposing surface 106 facing the inner peripheral surface 80A of the substrate 80. Further, the closing member 84 has a conical surface 108 whose one end is in contact with the opposing surface 106 and whose outer diameter is gradually reduced, and a cylindrical recess 110 surrounded by the opposing surface 106 and the conical surface 108. (See FIG. 3).

  As shown in FIG. 3, the recess 110 is formed of a bottom surface 110A and a peripheral surface 110B. A pair of slits 112 extending in the apparatus depth direction is formed on the peripheral surface 110B. The pair of slits 112 has the same shape, and is disposed symmetrically with respect to the center C1 of the through hole 102 when viewed from the depth direction of the apparatus, and is linear (straight) along the radial direction of the base material 80. ) (See FIG. 2A).

  Further, the closing member 84 has a pair of attachment portions 114 which are disposed inside the recess 110 and to which a pair of grounding springs 64 are respectively attached.

  The pair of attachment portions 114 have the same configuration, and are disposed on the side of the through hole 102 with respect to the pair of slits 112 and symmetrically with respect to the center C1 of the through hole 102 when viewed from the depth direction of the apparatus. (See FIG. 2A). The pair of attachment portions 114 each have a base portion 114A extending from the bottom surface 110A of the recess 110 to the near side in the apparatus depth direction, and a cylindrical columnar portion 114B protruding from the base portion 114A.

  The base 114A is plate-shaped, and as shown in FIG. 2 (A), the plate surface is oriented in the apparatus width direction with the slit 112 extending in the vertical direction when viewed from the apparatus depth direction. The shape is rectangular when viewed from the thickness direction (see FIG. 1).

  The cylindrical portion 114B protrudes from one plate surface of the base portion 114A, and is disposed between the slit 112 and the through hole 102 when viewed from the apparatus depth direction. The cylindrical portion 114B extends in the apparatus width direction in a state where the slit 112 extends in the vertical direction when viewed from the apparatus depth direction.

  The diameter of the through hole 102 of the closing member 84 is 5 [mm]. The blocking member 84 rotates integrally with the shaft member 54 by allowing the shaft member 54 to pass through the through hole 102.

  Further, an adhesive (for example, a cyanoacrylate adhesive) is applied to a portion of the substrate 80 that faces the facing surface 106. Then, the blocking member 84 is attached to the base material 80 by bonding the facing surface 106 to the base material 80 with this adhesive.

  In this configuration, a part of the blocking member 84 is inserted into the base member 80 by moving the blocking member 84 in the apparatus depth direction with respect to the base member 80.

−Shaft member 54−
The shaft member 54 uses a conductive SUM-Ni shaft (a shaft obtained by nickel plating on sulfur free-cutting steel) and has an outer diameter of 5 mm and a total length of 355 mm. Then, both end portions of the shaft member 54 are rotatably supported by the support member 98 as shown in FIG. The shaft member 54 is electrically connected to a metal frame (not shown) and is grounded. The shaft member 54 is an example of a grounded conductive member.

  Further, a gear 90 constituting the image forming unit 18 is attached to one end portion of the shaft member 54, and the rotational force from the motor 88 provided in the image forming apparatus 10 is transmitted through the gear 90 to the image. It is transmitted to the holding body 26.

-Grounding spring 64-
The pair of ground springs 64 are metal torsion springs, and are attached to the attachment portions 114 as shown in FIGS.

  The grounding spring 64 is formed using a wire having a diameter of 0.3 mm, and includes a coiled coil part 66, an arm part 68 protruding from one end of the coil part 66, and the other end of the coil part 66. And a projecting arm portion 70. The arm portion 68 is an example of a protruding portion, and the arm portion 70 is an example of another protruding portion.

  The inner diameter of the coil portion 66 is made larger than the outer diameter of the cylindrical portion 114B of the attachment portion 114. The cylindrical portion 114 </ b> B is inserted into the coil portion 66. Regarding the number of turns of the coil portion 66, the spring force (reaction force) of the ground spring 64 is more stable when the number of turns is larger than when the number of turns is small. For this reason, it is preferable to increase the number of turns of the coil part 66 within a range in which the coil part 66 does not protrude from the cylindrical part 114B.

  A portion of the arm portion 68 is disposed inside the slit 112, and as shown in FIG. 1, the arm portion 68 is L-shaped when viewed from the thickness direction of the base portion 114A of the mounting portion 114. The arm portion 68 has a rod-like base end portion 68A connected to one end of the coil portion 66 and a rod-like tip end portion 68B. Furthermore, the arm portion 68 has a curved curved portion 68C that connects the base end portion 68A and the distal end portion 68B in a curved state so that the inner peripheral surface 80A side of the substrate 80 is convex. doing.

  Specifically, the arm portion 68 extends from the coil portion 66 on the inner side in the axial direction of the base material 80 (on the closing member 82 side) and toward the inner peripheral surface 80 </ b> A side of the base material 80. Further, the arm portion 68 extends in one direction when viewed from the depth direction of the apparatus, and the arm portion 68 of the base material 80 is viewed from this one direction (arrow B in FIG. 2A). Along the axis line J1 (see FIG. 2B). A curved portion 68C that is bent and bent so that the inner peripheral surface 80A side of the substrate 80 is convex is pressed against the inner peripheral surface 80A of the substrate 80. In addition, about the outer diameter of the curved part 68C, in order to suppress the local deformation | transformation of the base material 80, outer diameter 1 [mm] or more is preferable and outer diameter 2 [mm] or more is more preferable.

  As shown in FIG. 1, the arm portion 70 is L-shaped when viewed from the thickness direction of the base portion 114 </ b> A of the attachment portion 114, and is connected to the other end of the coil portion 66. And a rod-shaped tip portion 70B. Furthermore, the arm portion 70 has a curved curved portion 70C that connects the proximal end portion 70A and the distal end portion 70B in a curved state so that the outer peripheral surface 54A side of the shaft member 54 is convex. ing. The bending portion 70C is an example of another bending portion.

  Specifically, the arm portion 70 extends from the coil portion 66 to the inner side in the axial direction of the base material 80 (on the closing member 82 side) and to the outer peripheral surface 54 </ b> A side of the shaft member 54. Moreover, the arm part 70 is extended in the radial direction of the shaft member 54 seeing from the apparatus depth direction (axial direction of the base material 80) (refer FIG. 2 (A)). A curved portion 70 </ b> C that is curved and bent so that the outer peripheral surface 54 </ b> A side of the shaft member 54 is convex is pressed against the outer peripheral surface 54 </ b> A of the shaft member 54.

  Further, the linear distance from the curved portion 68C to the curved portion 70C of the grounding spring 64 in the free state (state where no external force is applied) is the shortest distance from the inner peripheral surface 80A of the base member 80 to the outer peripheral surface 54A of the shaft member 54. Longer than distance. Then, mainly as a result of the elastic deformation of the coil portion 66, the curved portion 68C is pressed against the inner peripheral surface 80A of the base member 80, and the curved portion 70C is pressed against the outer peripheral surface 54A of the shaft member 54 as described above. Yes.

[Method for Producing Substrate 80]
Next, the manufacturing method of the base material 80 is demonstrated. The base material 80 is manufactured including impact processing for forming the cylindrical cylindrical material 206 and ironing processing for correcting the cylindrical material 206 to form the base material 80.

-Impact processing-
In impact processing, a cylindrical material 206 having a bottom and a cylindrical shape is formed from the slag 202 that is a lump of aluminum. In the impact processing, as shown in FIG. 8A, the concave mold 204 in which the slag 202 that is a lump of aluminum is accommodated, and the slag 202 accommodated in the concave mold 204 are pressed to make the slag 202 cylindrical. A cylindrical punch mold 200 is used. The concave portion 204A of the concave mold 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 die 200 is, for example, 30.6 [mm].

  In the impact process, first, the slag 202 is accommodated in the concave mold 204, and the punch mold 200 is disposed above the concave mold 204 (see FIG. 8A).

  Next, as shown in FIGS. 8B and 8C, the punch die 200 moves downward and crushes and deforms the slag 202 accommodated in the concave die 204. As a result, the slag 202 is deformed into a cylindrical material 206 having a bottom and a cylindrical shape along the peripheral surface of the punch die 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 die 200 moves upward, and as shown in FIG. 9A, the cylindrical material 206 that is in close contact with the punch die 200 is separated from the concave die 204. Further, as shown in FIG. 9B, the cylindrical material 206 is pulled out (demolded) from the punch mold 200.

-Ironing process-
In the ironing process, the thickness of the cylindrical material 206 is reduced, and the shape of the cylindrical material 206 is corrected. In the ironing process, as shown in FIG. 10, a punch die 220 inserted into the cylindrical material 206 (see FIG. 9B) from the front end (lower end in the figure), and an inner peripheral surface 206 </ b> A of the cylindrical material 206 (FIG. 9 (B)) is used as the ironing die 222 that follows the outer peripheral surface 220A of the punch die 220.

  The punch die 220 has a cylindrical shape extending in the vertical direction (one direction). As an example, the outer diameter of the punch die 220 is 29.2 [mm]. Further, the ironing die 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. 11A, the punch die 220 is inserted into the cylindrical member 206 from the tip.

  Next, the cylindrical material 206 into which the punch die 220 is inserted is shown in FIGS. 11B, 12C, 12A, 12B, and 12C from the position where the cylindrical material 206 is moved above the ironing die 222. In this way, it moves downward and passes through the inside of the ironing die 222. Thus, the ironing die 222 presses the cylindrical material 206 against the outer peripheral surface 220A of the punch die 220, so that the inner peripheral surface 206A of the cylindrical material 206 follows the outer peripheral surface 220A of the punch die 220, and further, the thickness of the cylindrical material 206 is increased. Becomes thinner.

  Next, as shown in FIGS. 13A and 13B, the cylindrical material 206 is pulled out (demolded) from the punch mold 220. Further, the lower end of the cylindrical material 206 is cut off, and as shown in FIG. 13C, a cylindrical base material 80 having both ends opened is formed.

(Effects of main components)
Next, the operation of the main configuration will be described.

  A motor 88 shown in FIG. 5 rotates the image carrier 26. As the image carrier 26 rotates, the charging member 38 rotates following the image carrier 26. Further, a voltage is applied to the shaft member 54 of the charging member 38 from a power source (not shown).

  As shown in FIG. 1, the image carrier 26 is grounded by electrically connecting the base member 80 constituting the image carrier 26 to the shaft member 54 via the grounding spring 64. Therefore, a current flows between the charging member 38 (see FIG. 5) and the image carrier 26, and the outer peripheral surface of the image carrier 26 is uniformly charged. Then, an electrostatic latent image is formed on the outer peripheral surface of the charged image carrier 26 by exposure light exposure by an exposure device 42 (see FIG. 7).

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

  Here, the action of the grounding spring 64 of the image holding body 26 will be described in comparison with the grounding member 564 of the image holding body 526 according to the comparative example. First, the difference between the image carrier 526 according to the comparative embodiment and the image carrier 26 will be mainly described.

-Image carrier 526
As shown in FIG. 14, the image holding body 526 is fitted to the base 80, the closing member 82, and the end of the base 80 in the depth direction of the apparatus to close the opening of the base 80. The closing member 584 and the shaft member 54 are provided. The image carrier 526 includes a metal grounding member 564 for grounding the image carrier 526 and a photosensitive layer 86 formed on the outer peripheral surface 80B of the base member 80.

  As shown in FIGS. 14 and 15, the closing member 584 has the end face of the base member 80 abutted in the axial direction of the base member 80 in a state where the closing member 584 is fitted to the end portion of the base member 80. The contact surface 584 </ b> B, and the contact surface 584 </ b> B are in contact with each other and have a facing surface 584 </ b> C that faces the inner peripheral surface 80 </ b> A of the substrate 80. Further, the closing member 584 has one end in contact with the opposing surface 584C, and is surrounded by a conical surface 584D having a gradually decreasing outer diameter and an end edge of the conical surface 584D, and has a circular shape facing the closing member 82 side. It has a circular surface 584E and a through hole 584A through which the shaft member 54 passes.

  The grounding member 564 is disposed inside the base material 80 on the closing member 82 side of the closing member 584. The ground member 564 includes a metal plate ground plate 566 and a pair of conductive members 568 made of resin and having a rectangular parallelepiped shape.

  The ground plate 566 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 main body portion 566A, a pair of ear portions 566B, and a pair of cut-and-raised portions 566C.

  The outer diameter of the main body portion 566A is similar to the outer diameter of the circular surface 584E of the closing member 584, and the main body portion 566A is overlapped with the circular surface 584E of the closing member 584. Then, the grounding member 564 is attached to the closing member 584 by fixing a fixing portion (not shown) of the main body portion 566A to a fixing portion (not shown) of the circular surface 584E. Specifically, the grounding member 564 is attached to the closing member 584 so that the main body portion 566A does not float from the circular surface 584E.

  A pair of ears 566B is provided across the center of the circular main body 566A, and each ear 566B closes a portion protruding in the radial direction of the main body 566A from the outer peripheral edge of the main body 566A. It is formed by bending toward the member 584 side. Thereby, the ear | edge part 566B is a cantilever part by which the base end was bent. And the front-end | tip (free end) of this ear | edge part 566B is pressed on the internal peripheral surface 80A of the base material 80 (refer FIG. 14). That is, the ear portion 566B is a leaf spring whose base end is elastically deformed.

  A pair of cut-and-raised portions 566C are provided across the center of the circular main body portion 566A. Each cut-and-raised portion 566C is formed by cutting and raising the portion that is surrounded by the outer peripheral edge of the main body portion 566A and is disposed on the same plane as the main body portion 566A to the closing member 82 side. . Thereby, the cut-and-raised portion 566C is a cantilever portion whose base end is bent. The cut-and-raised portion 566C is a leaf spring whose base end is elastically deformed.

  The conductive member 568 is formed in a rectangular parallelepiped shape using a resin material having conductivity. A pair of the conductive members 568 are provided, and the pair of conductive members 568 are respectively attached to the surfaces of the pair of cut-and-raised portions 566C facing each other using an attachment (not shown). In this state, conduction between the conductive member 568 and the cut and raised portion 566C is ensured. Then, as shown in FIG. 16, the pair of conductive members 568 are pressed against (in contact with) the outer peripheral surface 54 </ b> A of the shaft member 54.

-Action of the ground spring 64 and the ground member 564-
In the grounding member 564, as shown in FIG. 14, the tip (free end) of the ear portion 566B is pressed against the inner peripheral surface 80A of the base member 80, whereby the grounding member 564 and the base member 80 are electrically connected. It is connected to the. Specifically, the proximal end of the ear portion 566B is elastically deformed, so that the distal end of the ear portion 566B is pressed against the inner peripheral surface 80A of the base member 80.

  Furthermore, in the grounding member 564, as shown in FIG. 16, the conductive member 568 attached to the cut and raised portion 566C is pressed against the outer peripheral surface 54A of the shaft member 54, whereby the grounding member 564 and the shaft member are 54 is electrically connected. Specifically, the conductive member 568 is pressed against the outer peripheral surface 54 </ b> A of the shaft member 54 by elastically deforming the base end of the cut and raised portion 566 </ b> C.

  Thus, the ground member 564 is a leaf spring, and electrically connects the base member 80 and the shaft member 54.

  On the other hand, the grounding spring 64 is a torsion spring as shown in FIG. The bending portion 68C is pressed against the inner peripheral surface 80A of the base member 80 and the bending portion 70C is pressed against the outer peripheral surface 54A of the shaft member 54 mainly by elastic deformation of the coil portion 66.

(Summary)
As described above, in the grounding member 564, the distal end of the ear portion 566 </ b> B is pressed against the inner peripheral surface 80 </ b> A of the base member 80 by elastic deformation of the proximal end of the ear portion 566 </ b> B. On the other hand, in the ground spring 64, the bending portion 68 </ b> C is pressed against the inner peripheral surface 80 </ b> A of the base material 80 mainly due to the elastic deformation of the coil portion 66.

  Thus, the volume of the portion of the grounding member 564 that is elastically deformed is smaller than the volume of the portion of the grounding spring 64 that is elastically deformed. For this reason, the pressing force with which the tip of the ear portion 566B is pressed against the inner peripheral surface 80A of the base member 80 varies between parts compared to the pressing force with which the curved portion 68C is pressed against the inner peripheral surface 80A of the base member 80. End up.

  In other words, in the grounding spring 64, the spring is pressed against the inner peripheral surface 80 </ b> A of the base member 80 as compared with the case where the free end of the bent portion such as a leaf spring is pressed against the inner peripheral surface of the base member 80. The force is prevented from varying between parts.

  In addition, when the plate thickness of the substrate 80 is thin (for example, plate thickness 0.4 [mm]), the perfect circle of the pressed portion of the substrate 80 by the pressing force of the grounding spring 64 or the grounding member 564 is used. The degree will decrease. However, as compared with the case where the grounding member 564 is used for the grounding spring 64, the pressing force that presses the spring against the inner peripheral surface 80A of the base member 80 is prevented from varying between components. In other words, by using the grounding spring 64, the maximum pressing force against the base member 80 is reduced as compared with the case where the grounding member 564 is used while ensuring the lower limit pressing force necessary for grounding.

  Moreover, since the pressing force with respect to the base material 80 becomes small, the fall of the roundness of the base material 80 is suppressed compared with the case where the grounding member 564 is used.

  Further, the arm portion 68 extends in one direction when viewed from the depth direction of the apparatus, and the arm portion 68 is formed on the base material 80 when viewed from this one direction (arrow B in FIG. 2A). Along the axis line J1 (see FIG. 2B). For this reason, as compared with the case where the arm portion is inclined with respect to the axis J1, the pressing force for pressing the spring against the inner peripheral surface 80A of the base member 80 is suppressed from being varied between components.

  Further, as compared with the case where the arm portion is inclined with respect to the axis J1, the base member 80 is moved by moving the closing member 84 to which the ground spring 64 is attached in the apparatus depth direction (the axial direction of the base material 80). When inserting, it is suppressed that the arm part 68 falls down in the circumferential direction of the base material 80. FIG.

  Further, the curved portion 68 </ b> C of the arm portion 68 is pressed against the inner peripheral surface 80 </ b> A of the base material 80. For this reason, compared with the case where a corner | angular part is pressed on the internal peripheral surface 80A of the base material 80, the damage | wound of the internal peripheral surface 80A of the base material 80 is suppressed, for example.

  Further, the bending portion 68C is formed by bending and bending the wire so that the inner peripheral surface 80A side of the substrate 80 is convex. For this reason, unlike the case where the curved portion is formed by cutting the end portion of the member, the curved portion 68C is formed without using a polishing machine.

  Further, the curved portion 70 </ b> C of the arm portion 70 of the ground spring 64 is pressed against the outer peripheral surface 54 </ b> A of the shaft member 54. Thus, the base material 80 and the shaft member 54 are electrically connected only by the grounding spring 64 obtained by processing the wire.

  Further, the arm portion 70 of the ground spring 64 extends in the radial direction of the shaft member 54 when viewed from the apparatus depth direction (the axial direction of the base material 80) (see FIG. 2A). In other words, the pressing direction in which the arm portion 70 is pressed against the outer peripheral surface 54 </ b> A of the shaft member 54 is directed toward the center of the shaft member 54 when viewed from the apparatus depth direction (the axial direction of the base material 80). For this reason, the bending portion 70C of the arm portion 70 is pressed against the outer peripheral surface 54A of the shaft member 54 as compared with the case where the arm portion 70 is inclined with respect to the radial direction of the shaft member 54 when viewed from the apparatus depth direction. It is possible to suppress the pressing force from being varied between parts.

  Further, the curved portion 70 </ b> C of the arm portion 70 is pressed against the outer peripheral surface 54 </ b> A of the shaft member 54. For this reason, for example, compared with the case where the corner portion is pressed against the outer peripheral surface 54A of the shaft member 54, the outer peripheral surface 54A of the shaft member 54 is prevented from being damaged.

  Further, the bending portion 70C is formed by bending and bending the wire so that the outer peripheral surface 54A side of the shaft member 54 is convex. For this reason, unlike the case where the bending portion is formed by cutting the end portion of the member, the bending portion 70C is formed without using a polishing machine.

  In the image forming unit 18, since the image holding member 26 is provided, a decrease in the roundness of the base member 80 is suppressed as compared with the case where the image holding member 526 is provided. Density unevenness of the image is suppressed.

  In the image forming apparatus 10, by providing the image holding body 26, a decrease in the roundness of the base material 80 is suppressed as compared with the case where the image holding body 526 is provided. Is done.

Second Embodiment
An example of the image carrier, 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. In addition, about 2nd Embodiment, a different part from 1st Embodiment is mainly demonstrated.

(Constitution)
As shown in FIG. 17, the image carrier 326 of the second embodiment is fitted to the base 80, the photosensitive layer 86, and the end of the base 80 on the near side in the apparatus depth direction. And a closing member 382 that closes the opening. Further, the image holding body 326 is a metal member for grounding the image holding body 26 and a closing member 384 that is fitted to the end of the base material 80 in the depth direction of the apparatus and closes the opening of the base material 80. And a pair of grounding springs 364 made of metal. Further, the image holding body 326 includes a shaft member 354 that constitutes a part of the rotation shaft of the image holding body 326. The ground spring 364 is an example of a torsion spring.

[Occlusion member 382]
The closing member 382 is formed using a polycarbonate resin, and as shown in FIG. 17, a part of the closing member 382 is inserted into the base member 80 to be fitted to the end of the base member 80. It has been.

  The closing member 382 includes a contact surface 382B in which the end surface of the base material 80 is abutted in the axial direction of the base material 80 in a state where the closing member 382 is fitted to the end portion of the base material 80, and a contact surface 382B. And one end thereof in contact with each other, and has an opposing surface 382C facing the inner peripheral surface 80A of the substrate 80. Further, the closing member 382 has a conical surface 382D whose one end is in contact with the opposing surface 382C and whose outer diameter gradually decreases, and a through hole 382A through which the shaft member 354 passes.

  The diameter of the through hole 382A is set to 5.2 [mm]. The blocking member 382 rotates about the shaft member 354 by passing a shaft member 354 described later through the through-hole 382A. Further, the portion of the inner peripheral surface 80A of the base member 80 that faces the facing surface 382C and the facing surface 382C of the closing member 382 are bonded with an adhesive S (for example, a cyanoacrylate adhesive).

[Occlusion member 384]
The closing member 384 is formed using a polycarbonate resin. As shown in FIG. 17, a part of the closing member 384 is inserted into the base member 80 so that the closing member 384 is fitted to the end of the base member 80. It has been.

  The closing member 384 includes a contact surface 404 on which the end surface of the base material 80 is abutted in the axial direction of the base material 80 in a state where the closing member 384 is fitted to the end portion of the base material 80, and a contact surface 404. One end is in contact with the inner peripheral surface 80 </ b> A of the base material 80. Further, the closing member 384 has a conical surface 408 whose one end is in contact with the opposing surface 406 and whose outer diameter gradually decreases, and a cylindrical recess 410 surrounded by the opposing surface 406 and the conical surface 408. (See FIG. 19).

  As shown in FIG. 17, the closing member 384 has a protruding portion 420 having a circular cross section that protrudes in the opposite direction to the closing member 382 and extends in the apparatus depth direction. The base end side portion of the protruding portion 420 is rotatably supported by a through hole (reference numeral omitted) formed in the support member 98. Furthermore, a gear portion 420 </ b> A having gear teeth is formed on the tip side portion of the protruding portion 420. The rotational force from the motor 88 provided in the image forming apparatus 10 is transmitted to the image holding body 326 through the gear portion 420A.

  Further, the closing member 384 has a through hole 402 through which a shaft member 322 attached to a frame (not shown) and extending in the apparatus depth direction passes. The diameter of the through hole 402 is set to 5.2 [mm]. Further, the tip of the shaft member 322 protrudes from the closing member 384 into the base member 80. The shaft member 332 constitutes another part of the rotation shaft of the image carrier 326, and a conductive SUM-Ni shaft (a shaft obtained by nickel plating on sulfur free-cutting steel) is used. 5 [mm].

  Further, as shown in FIGS. 18A and 19, the recess 410 of the closing member 384 is formed of a bottom surface 410A and a peripheral surface 410B, and a pair of peripheral surfaces 410B extending in the apparatus depth direction. A slit 412 is formed. The pair of slits 412 have the same shape, are arranged symmetrically with respect to the center C2 of the through hole 402 when viewed from the depth direction of the apparatus, and extend along the radial direction of the base material 80 ( FIG. 18A).

  In addition, the closing member 384 has a pair of attachment portions 414 that are disposed inside the recess 410 and to which a pair of ground springs 364 are respectively attached.

  The pair of attachment portions 414 have the same configuration, and are disposed symmetrically with respect to the pair of slits 412 on the through hole 402 side and with respect to the center C2 of the through hole 402 when viewed from the depth direction of the apparatus. (See FIG. 18A). The pair of attachment portions 414 respectively have a base portion 414A extending from the bottom surface 410A of the recess 410 to the near side in the apparatus depth direction, and a columnar columnar portion 414B protruding from the base portion 414A. Furthermore, each of the pair of attachment portions 414 has a cylindrical columnar portion 414C extending from the bottom surface 410A to the near side in the apparatus depth direction.

  The base 414A is plate-shaped, and as shown in FIG. 18A, the plate surface faces the device width direction in a state where the slit 412 extends in the vertical direction when viewed from the device depth direction. The rectangular shape is viewed from the thickness direction (see FIG. 17).

  The cylindrical portion 414B protrudes from one plate surface of the base portion 414A, and is disposed between the slit 412 and the through hole 402 when viewed from the apparatus depth direction. The cylindrical portion 414B extends in the device width direction in a state where the slit 412 extends in the vertical direction when viewed from the device depth direction.

  The cylindrical part 414C is disposed on the opposite side of the cylindrical part 414B across the base 414A when viewed from the apparatus depth direction, and extends in the apparatus depth direction.

[Shaft member 354]
The shaft member 354 shown in FIG. 17 uses a conductive SUM-Ni shaft (a shaft obtained by applying nickel plating to sulfur free-cutting steel) and has an outer diameter of 5 mm. The proximal end of the shaft member 354 is attached to the support member 98, and the distal end of the shaft member 354 protrudes from the closing member 382 into the base material 80.

  In addition, the shaft member 354 is disposed coaxially with the shaft member 322 described above. The tip end of the shaft member 354 and the tip end of the shaft member 322 are opposed to each other in the apparatus depth direction inside the base material 80.

  In this configuration, when the rotational force from the motor 88 is transmitted to the image carrier 326 via the gear portion 420A, the base member 80, the closing member 382, the closing member 384, and the grounding spring 364 are converted into the shaft member 322, It rotates about 354. Specifically, the base member 80, the closing member 382, the closing member 384, and the ground spring 364 rotate around the shaft members 322 and 354 without rotating the shaft members 322 and 354.

[Grounding spring 364]
The pair of ground springs 364 are metal torsion springs, and are attached to the attachment portions 414 of the closing member 384 as shown in FIGS.

  The ground spring 364 has a wire diameter of 0.3 [mm], and includes a coiled coil portion 366 and an arm portion 368 protruding from one end of the coil portion 366. Furthermore, the ground spring 364 includes a coiled coil portion 378, a connecting portion 386 that connects the other end of the coil portion 366 and one end of the coil portion 378, and an arm portion 380 that protrudes from the other end of the coil portion 378. doing. The arm portion 368 is an example of a protruding portion, and the arm portion 380 is an example of another protruding portion. The coil portion 366 is an example of a first coil portion, and the coil portion 378 is an example of a second coil portion.

  The inner diameter of the coil portion 366 is made larger than the outer diameter of the cylindrical portion 414B of the mounting portion 414. The cylindrical portion 414B is inserted into the coil portion 366. That is, the axial direction of the coil part 366 is the same as the axial direction of the cylindrical part 424B.

  A part of the arm portion 368 is disposed inside the slit 412, and is L-shaped when viewed from the thickness direction of the base portion 414A of the mounting portion 414. The arm portion 368 has a rod-like base end portion 368A connected to one end of the coil portion 366 and a rod-like tip end portion 368B. Further, the arm portion 368 has a curved curved portion 368C that connects the base end portion 368A and the distal end portion 368B in a curved state so that the inner peripheral surface 80A side of the substrate 80 is convex. doing.

  Specifically, the arm portion 368 extends from the coil portion 366 on the inner side in the axial direction of the base material 80 (on the closing member 382 side) and toward the inner peripheral surface 80A of the base material 80. Further, the arm portion 368 extends in one direction when viewed from the depth direction of the apparatus, and the arm portion 368 corresponds to the base material 80 when viewed from this one direction (arrow D in FIG. 18A). Along the axis line J1 (see FIG. 18B). Further, the curved portion 368C of the ground spring 364 in the free state is disposed on the outer side in the radial direction of the base material 80 (the side away from the axis of the base material 80) with respect to the inner peripheral surface 80A (virtual surface) of the base material 80. Has been.

  Then, the bending portion 368C that is bent and bent so that the inner peripheral surface 80A side of the base member 80 is convex is pressed against the inner peripheral surface 80A of the base member 80 mainly due to the elastic deformation of the coil portion 366. ing.

  Further, the inner diameter of the coil portion 378 is made larger than the outer diameter of the cylindrical portion 414C of the mounting portion 414. A cylindrical portion 414C is inserted into the coil portion 378. That is, the axial direction of the coil part 378 and the axial direction of the cylindrical part 414C are the same. Further, the axial direction of the coil portion 378 is different from the axial direction of the coil portion 366.

  As shown in FIG. 19, the connecting portion 366 connects the other end of the coil portion 366 and one end of the coil portion 378 in a bent state.

  The arm portion 380 has a linear shape and is in contact with the outer peripheral surface 322 </ b> A of the shaft member 322. As shown in FIG. 18A, the arm portion 380 extends in the tangential direction of the contact S1 that contacts the shaft member 322 when viewed from the apparatus depth direction. Further, the arm portion 380 of the ground spring 364 in the free state is arranged on the inner side in the radial direction of the base material 80 (the side closer to the axis of the base material 80) with respect to the outer peripheral surface 322A (virtual surface) of the shaft member 322. ing.

  The arm 380 is pressed against the outer peripheral surface 322 </ b> A of the shaft member 322 from the radial direction of the shaft member 322 mainly due to the elastic deformation of the coil portion 378.

(Summary)
As described above, the arm portion 380 extends in the tangential direction of the contact S1 in contact with the shaft member 322 when viewed from the apparatus depth direction (see FIG. 18A). For this reason, even when the grounding spring 364 rotates relative to the shaft member 322, the arm portion 380 does not have the arm portion 380 extending in the radial direction of the shaft member when viewed from the apparatus depth direction. The periodic deformation by the frictional force generated between the shaft member 322 and the shaft member 322 is suppressed.

  Further, the pressing force of the ground spring 364 against the inner peripheral surface 80 </ b> A of the substrate 80 is mainly generated by elastic deformation of the coil portion 366. Further, the pressing force of the ground spring 364 against the outer peripheral surface 322A of the shaft member 322 is mainly generated by the elastic deformation of the coil portion 378. For this reason, in the ground spring 364, the pressing force against the inner peripheral surface 80A of the base member 80 and the pressing force against the outer peripheral surface 322A of the shaft member 322 are set individually.

  Further, the axial direction of the coil portion 378 is different from the axial direction of the coil portion 366. For this reason, the pressing direction in which the arm portion 380 is pressed against the outer peripheral surface 322A of the shaft member 322 and the pressing direction in which the arm portion 368 is pressed against the inner peripheral surface 80A of the base member 80 can be changed. In other words, the pressing direction in which the arm portion 380 is pressed against the outer peripheral surface 322A of the shaft member 322 is determined without being limited by the pressing direction in which the arm portion 368 is pressed against the inner peripheral surface 80A of the base member 80.

  As for other actions of the second embodiment, the action of the arm part 70 of the grounding spring 64 extending in the radial direction of the shaft member 54 when viewed from the depth direction of the apparatus is excluded. It is the same as the action.

  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. This will be apparent to those skilled in the art. For example, although not specifically described in the above embodiment, the closing members 84 and 384 may be integrally formed, and are formed by assembling each member after being formed by being divided into a plurality of members. May be.

  In the above-described embodiment, the arm portions 68, 70, 368 are bent into a curved shape to form the curved portions 68 C, 70 C, 368 C, and the curved portions 68 C, 70 C, 368 C are the inner peripheral surface of the base material 80. It was pressed against 80A or the outer peripheral surface 54A of the shaft member 54. However, the portion pressed against the inner peripheral surface 80A of the base member 80 or the outer peripheral surface 54A of the shaft member 54 only needs to be curved, and is curved by scraping the end portion of the member (wire rod). The curved portion may be pressed against the inner peripheral surface 80A of the base member 80 or the outer peripheral surface 54A of the shaft member 54.

  Moreover, in the said embodiment, although the base material 80 and the shaft members 54 and 322 were electrically connected using the coiled torsion spring, the coiled compression coil spring is connected to the inner peripheral surface 80A of the base material 80 and the shaft member. The base member 80 and the shaft members 54 and 322 may be electrically connected by arranging them in a compressed state between the outer peripheral surfaces 54A and 322A of the pins 54 and 322.

  In the first embodiment, the arm portion 70 extends in the radial direction of the shaft member 54 when viewed from the device depth direction. However, the arm portion may be bent when viewed from the device depth direction. The pressing direction of the arm portion against the shaft member 54 only needs to be toward the center of the shaft member 54.

  In the first embodiment, the arm portion 70 is in contact with the outer peripheral surface 54A of the shaft member 54, but the ground spring 64 may be electrically connected to the shaft member by other methods.

  In the second embodiment, the arm portion 380 extends in the tangential direction of the contact S1 in contact with the shaft member 322 when viewed from the apparatus depth direction, but the entire arm portion 380 does not extend in the tangential direction. In other words, the portion of the arm portion 380 that contacts the shaft member 322 only needs to extend in the tangential direction.

  Further, the ground spring 364 of the second embodiment includes two coil portions, but may include three or more coil portions.

DESCRIPTION OF SYMBOLS 10 Image forming apparatus 18 Image forming unit 26 Image holding body 36 Developing apparatus 38 Charging member 46 Secondary transfer roll (an example of transfer member)
54 Shaft member 54A Outer peripheral surface 64 Grounding spring (an example of a torsion spring)
66 Coil part 68 Arm part (an example of a protrusion part)
68C bending portion 70 arm portion (an example of another protruding portion)
70C bending portion (an example of another bending portion)
80 Base material 80A Inner peripheral surface 86 Photosensitive layer 322 Shaft member 322A Outer peripheral surface 326 Image carrier 364 Ground spring (an example of a torsion spring)
366 Coil part (an example of the first coil part)
368 Arm (Example of protrusion)
368C bending portion 378 coil portion (an example of second coil portion)
380 Arm (an example of another protrusion)

Claims (14)

A metal cylindrical substrate;
A photosensitive layer formed on the outer peripheral surface of the substrate;
A metal spring having a coiled coil portion, pressed against the inner peripheral surface of the substrate, and electrically connected to a grounded conductive member;
An image carrier comprising The spring is a torsion spring having the coil part and a protruding part that protrudes from one end of the coil part and is pressed against the inner peripheral surface.
The image carrier according to claim 1, wherein the protrusion extends in one direction when viewed from the axial direction of the base material, and the protrusion extends along the axis of the base material when viewed from the one direction. .   The image carrier according to claim 2, wherein a portion of the protrusion that is pressed against the inner peripheral surface of the base material is curved.   The said protrusion part has a curved part bent so that the internal peripheral surface side of the said base material may become convex, The said curved part is pressed on the internal peripheral surface of the said base material. Image carrier. The torsion spring has another protruding portion that protrudes and extends from the other end of the coil portion,
5. The image carrier according to claim 2, wherein the other projecting portion constitutes a rotation shaft of the base material and is pressed against a metal shaft member as the conductive member. 6. . The torsion spring rotates integrally with the shaft member,
The image carrier according to claim 5, wherein the other protrusion extends in a radial direction of the shaft member when viewed from the axial direction of the base material.   The image holding body according to claim 5 or 6, wherein a portion of the other projecting portion that is pressed against the outer peripheral surface of the shaft member is curved.   The other projecting portion has another curved portion bent so that the outer peripheral surface side of the shaft member is convex, and the other curved portion is pressed against the outer peripheral surface of the shaft member. 8. The image holding member according to 7. The torsion spring rotates relative to the shaft member;
The image carrier according to claim 5, wherein when viewed from the axial direction of the base material, the other protrusion extends in a tangential direction of a contact point in contact with the shaft member.   The coil portion includes a first coil portion from which the protruding portion protrudes, and a second coil portion connected to the first coil portion and protruding from the other protruding portion. The image carrier according to any one of the above.   The image holding body according to claim 10, wherein an axial direction of the first coil portion is different from an axial direction of the second coil portion. The image carrier according to any one of claims 1 to 11,
A charging member for charging the outer peripheral surface of the image carrier;
An image forming unit comprising: An image forming unit according to claim 12,
A developing device that develops, as a toner image, an electrostatic latent image formed by exposing the outer peripheral surface of the charged image carrier;
A transfer member for transferring a toner image formed on the outer peripheral surface of the image carrier to a recording medium;
An image forming apparatus comprising: The image carrier according to any one of claims 1 to 11,
A charging member for charging the outer peripheral surface of the image carrier;
A developing device that develops, as a toner image, an electrostatic latent image formed by exposing the outer peripheral surface of the charged image carrier;
A transfer member for transferring a toner image formed on the outer peripheral surface of the image carrier to a recording medium;
An image forming apparatus comprising: