JP5967285B1 - Support member, image carrier, and image forming apparatus - Google Patents

Abstract

A support member capable of increasing the pressing force for pressing an inner peripheral surface of a cylindrical body while maintaining vibration absorption due to internal damping as compared with a case where the groove depth of the groove portion is constant, and image holding Body and image forming device. A groove depth D1 on the center side in the apparatus depth direction in the groove 118 is deeper than a groove depth D2 on both ends in the apparatus depth direction in the groove 118. The thickness of the bottom plate 118A of the groove 118 is the same in the apparatus depth direction. [Selection] Figure 1

Description

  The present invention relates to a support member, an image carrier, and an image forming apparatus.

  In the image forming apparatus described in Patent Document 1, a sliding contact member is disposed inside the photosensitive drum so as to slidably contact the inner peripheral surface of the photosensitive drum and press the inner peripheral surface with a predetermined force. Yes.

Japanese Patent Laid-Open No. 08-54804

  The sliding contact member (support member) described in Patent Document 1 has a C-shaped cross section in which a groove portion extending in the longitudinal direction is formed. Further, the groove depth of the groove portion is constant in the axial direction.

  Then, the sliding plate is inserted into the photosensitive drum (cylindrical body) after the sliding member is bent by elastically deforming the bottom plate of the groove. Furthermore, the elastic restoring force of the bottom plate of the elastically deformed groove portion prevents the photosensitive drum from vibrating by the outer peripheral surface of the sliding contact member pressing the inner peripheral surface of the photosensitive drum. In other words, as the plate thickness of the bottom plate increases, the pressing force with which the outer peripheral surface of the sliding contact member presses the inner peripheral surface of the photosensitive drum increases as compared with the case where the plate thickness is thinner. Deformation of a typical cross section).

  On the other hand, when the slidable contact member vibrates together with the photosensitive drum, the bottom plate, which is thinner than other parts, is distorted, and vibration absorption due to internal damping occurs. That is, as the plate thickness of the groove portion is thinner, the groove portion is easily distorted and vibration absorption due to internal damping occurs as compared with the case where the plate thickness of the groove portion is thicker.

  Therefore, when the plate thickness of the groove portion of the sliding contact member (Patent Document 1) is reduced in order to cause vibration absorption due to internal damping, the pressing force of the sliding contact member against the inner peripheral surface of the photosensitive drum is insufficient. Occurs.

  The subject of this invention is strengthening the pressing force which presses the internal peripheral surface of a cylinder compared with the case where the groove depth of a groove part is constant.

  The support member according to claim 1 of the present invention has an arcuate shape that is supported inside a cylindrical body constituting the image holding body, and a part extending in the axial direction of the cylindrical body is formed in a part in the circumferential direction. In addition, a groove portion whose groove depth repeatedly increases and decreases in the axial direction is formed on the outer peripheral surface along the axial direction, and the bottom plate of the groove portion is elastically deformed to elastically deform at least both end portions in the axial direction. The inner peripheral surface of the cylindrical body is pressed and supported inside the cylindrical body.

  An image holding body according to a second aspect of the present invention includes a cylindrical body having a cylindrical shape on which a toner image is formed, and a support member according to the first aspect, which is supported inside the cylindrical body. It is characterized by.

  According to a third aspect of the present invention, there is provided an image forming apparatus according to the second aspect, a charging device for charging the image holding member, and exposing the charged image holding member to form an electrostatic latent image. An exposure device for forming, a developing device for developing an electrostatic latent image formed on the surface of the image carrier as a toner image, and a transfer device for transferring the toner image formed on the surface of the image carrier to a recording medium And.

  According to the support member of the first aspect of the present invention, the pressing force for pressing the inner peripheral surface of the cylindrical body can be increased as compared with the case where the groove depth is not repeatedly increased or decreased in the axial direction.

  According to the image carrier of claim 2 of the present invention, it is possible to suppress the deterioration of the quality of the toner image formed on the image carrier as compared with the case where the support member according to claim 2 is not provided. .

  According to the formation of the image forming apparatus of the third aspect of the present invention, it is possible to suppress the deterioration of the quality of the output image as compared with the case where the image holding body according to the third aspect is not provided.

(A) (B) It is the front view which showed the supporting member which concerns on 1st Embodiment of this invention, and the S1-S1 sectional view taken on the line of FIG. (A) (B) It is sectional drawing which showed the supporting member which concerns on 1st Embodiment of this invention. It is the perspective view which showed the supporting member which concerns on 1st Embodiment of this invention. It is sectional drawing which showed the image holding body etc. which concern on 1st Embodiment of this invention. FIG. 3 is a configuration diagram illustrating an image forming unit provided in the image forming apparatus according to the 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) The front view which showed the supporting member which concerns on the comparison form with respect to the supporting member which concerns on 1st Embodiment of this invention, and the S2-S2 sectional view taken on the line of FIG. 7 (A). (A) (B) The front view which showed the supporting member which concerns on 2nd Embodiment of this invention, and the S3-S3 sectional view taken on the line of FIG. 8 (A). (A) (B) It is the front view which showed the supporting member which concerns on 3rd Embodiment of this invention, and the S4-S4 sectional view taken on the line of FIG. 9 (A). (A) (B) It is the front view which showed the supporting member which concerns on 4th Embodiment of this invention, and the S5-S5 sectional view taken on the line of FIG. 10 (A).

<First Embodiment>
An example of a support member, an image carrier, and an 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 shown in FIG. 6, the image forming apparatus 10 according to the present embodiment includes an accommodating portion 14 that accommodates a sheet member P as a recording medium from below to above in the vertical direction (arrow H direction). , A conveyance unit 16 that conveys the sheet member P accommodated in the accommodation unit 14, an image forming unit 20 that forms an image on the sheet member P conveyed by the conveyance unit 16 from the accommodation unit 14, and an original that reads the read original G The reading unit 22 is provided in this order.

[Container]
The accommodating portion 14 includes an accommodating member 26 that can be pulled out from the apparatus main body 10 </ b> A of the image forming apparatus 10 to the near side in the apparatus depth direction, and the sheet member P is stacked on the accommodating member 26. Further, the accommodating portion 14 is provided with a delivery roll 32 that sends the stacked sheet members P to the conveyance path 28 that constitutes the conveyance portion 16.

[Transport section]
The transport unit 16 includes a plurality of transport rolls 34 that transport the sheet member P along the transport path 28.
[Original reading section]
The document reading unit 22 includes a light source 44 that emits light to the read document G conveyed by the automatic document conveyance device 40 that conveys the read document G or to the read document G placed on the platen glass 42. .

(Image forming part)
As shown in FIG. 5, the image forming unit 20 includes an image carrier 56 and a charging roll 58 as an example of a charging device that charges the surface of the image carrier 56. Further, the image forming unit 20 exposes the surface of the image carrier 56 charged based on the image data to form an electrostatic latent image, and develops the electrostatic latent image. And a developing device 62 that visualizes the toner image.

  Further, the image forming unit 20 transfers the toner image formed on the surface of the image carrier 56 on the sheet member P conveyed along the conveyance path 28 at a transfer position T that contacts the image carrier 56. A roll 64 is provided. The image forming unit 20 includes a fixing device 66 (see FIG. 6) that heats and pressurizes the toner image on the sheet member P and fixes the toner image on the sheet member P.

  Details of the image carrier 56 and the charging roll 58 will be described later.

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

  First, the charging roll 58 to which a voltage is applied comes into contact with the surface of the image carrier 56 and uniformly charges the surface of the image carrier 56 at a predetermined potential. Subsequently, the exposure device 60 irradiates the surface of the image carrier 56 charged by the exposure device 60 based on image data read by the document reading unit 22 or data input from the outside to form an electrostatic latent image.

  As a result, an electrostatic latent image corresponding to the image data is formed on the surface of the image carrier 56. Further, the electrostatic latent image is developed by the developing device 62 and visualized as a toner image.

  Therefore, the sheet member P sent out from the storage member 26 to the transport path 28 by the sending roll 32 is sent out to the transfer position T. At the transfer position T, the sheet member P is nipped and conveyed between the image carrier 56 and the transfer roll 64, whereby the toner image formed on the surface of the image carrier 56 is transferred to the sheet member P.

  The toner image transferred to the sheet member P is fixed to the sheet member P by the fixing device 66. Then, the sheet member P on which the toner image is fixed is discharged to the outside of the apparatus main body 10A by the transport roll 34.

(Main part configuration)
Next, the image carrier 56 and the charging roll 58 will be described.

[Charging roll]
As shown in FIG. 4, the charging roll 58 extends in the depth direction of the apparatus, and has a shaft portion 58A formed of a metal material (for example, stainless steel) and a cylindrical shape with the shaft portion 58A penetrating therein. And a roll part 58B formed in the above.

  Further, both end portions of the shaft portion 58A are exposed to the outside from the roll portion 58B and are rotatably supported by the pair of bearing members 102. A biasing member 104 that biases each bearing member 102 toward the image holding body 56 is disposed on the opposite side of the image holding body 56 with the shaft portion 58A interposed therebetween. With this configuration, when the roll portion 58B of the charging roll 58 is pressed against the image holding body 56 and the image holding body 56 rotates, the charging roll 58 is driven to rotate.

  Further, a superimposed voltage obtained by superimposing an AC voltage on a DC voltage is applied from the power source 106 to the shaft portion 58A.

(Image carrier)
As shown in FIG. 4, the image holding body 56 includes a cylindrical cylinder 108 extending in the apparatus depth direction, and one end side of the cylinder 108 in the apparatus depth direction (the same direction as the axial direction of the cylinder 108). And a transmission member 110 fixed to the upper side in the drawing. Further, the image holding body 56 includes a base material 112 that is fixed to the other end side (lower side in the drawing) of the cylindrical body 108 in the apparatus depth direction. Further, the image holding body 56 includes a support member 116 that is disposed inside the cylinder 108 and suppresses the deformation (vibration) of the cross section of the cylinder 108 periodically.

  The cylindrical body 108 is obtained by applying a photosensitive layer to the outer surface of a base material in which a metal material is formed in a cylindrical shape. In this embodiment, the base material of the cylinder 108 is an aluminum tube, and the thickness of the cylinder 108 is 0.8 [mm]. The outer diameter of the cylinder 108 is 23 [mm], and the length of the cylinder 108 in the apparatus depth direction is 250 [mm].

  The transmission member 110 is formed in a disk shape with a resin material, and is fixed to one end side of the cylinder body 108 by being partially fitted inside the cylinder body 108, and closes one end side of the opened cylinder body 108. Yes. Further, the transmission member 110 is formed with a cylindrical through hole 110 </ b> A having the axial center F of the cylindrical body 108 as an axis. A plurality of recesses 110B are formed on the outer surface of the transmission member 110 facing the outside in the apparatus depth direction so as to sandwich the through hole 110A.

  The base material 112 is formed in a disk shape with a resin material, and is fixed to the other end side of the cylinder body 108 by being partially fitted inside the cylinder body 108, and the other end side of the opened cylinder body 108 is closed. doing. Further, the base material 112 is formed with a columnar through-hole 112 </ b> A having the axial center F of the cylindrical body 108 as an axis. Details of the support member 116 will be described later.

[Others]
As shown in FIG. 4, a motor 80 that generates a rotational force transmitted to the image carrier 56 (transmission member 110) is disposed on one end side in the apparatus depth direction of the image carrier 56.

  The motor 80 is attached to a plate-like frame 84. Further, the motor shaft portion 80 </ b> A of the motor 80 is inserted into the through hole 110 </ b> A of the transmission member 110. In addition, a plate-like bracket 88 having a bent tip portion inserted into the recess 110B of the transmission member 110 is fixed to the outer peripheral surface of the motor shaft portion 80A. As a result, the transmission member 110 transmits the rotational force generated by the motor 80 to the cylindrical body 108.

  On the other hand, a stepped columnar shaft member 90 that rotatably supports the image carrier 56 (base material 112) is disposed on the other end side of the image carrier 56 in the apparatus depth direction. The shaft member 90 is attached to a plate-like frame member 92.

  The shaft member 90 has a shaft portion 90 </ b> C that extends on the shaft center F of the cylindrical body 108 and is inserted into the through hole 112 </ b> A of the base material 112. Further, a gap is provided between the inner peripheral surface of the through hole 112A and the outer peripheral surface of the shaft portion 90C, and the base material 112 functions as a so-called slide bearing with respect to the shaft portion 90C.

  In this configuration, when the motor 80 is operated, the motor shaft 80A rotates. The rotation of the motor shaft 80A is transmitted to the cylinder 108 via the bracket 88 and a transmission member 110 fixed to one end of the cylinder 108. Then, the base material 112 fixed to the other end side of the cylindrical body 108 rotates with respect to the shaft portion 90 </ b> C, so that the image holding body 56 rotates about the axis center F.

(Support member)
Next, the support member 116 supported inside the cylinder 108 will be described.

  As shown in FIG. 4, the support member 116 is fitted inside the cylinder 108 and arranged on the center side of the cylinder 108 in the apparatus depth direction. As shown in FIG. 2B, the arcuate outer peripheral surface 120 of the support member 116 contacts the inner peripheral surface 108A of the cylindrical body 108 and presses the inner peripheral surface 108A, so that the support member 116 is cylindrical. It is supported by the body 108.

  Specifically, the support member 116 is formed using ABS resin (acrylonitrile butadiene styrene) which is a resin material. In the state where the support member 116 is supported inside the cylindrical body 108, the support member 116 has a C shape (both ends facing each other along the inner peripheral surface 108 </ b> A of the cylindrical body 108 when viewed from the depth direction of the apparatus. Arc-shaped). Furthermore, a space 116 </ b> A that is spaced apart in the circumferential direction is formed between the opposite ends. The spacing space 116A is an example of a spacing portion. Further, as shown in FIG. 3, the support member 116 extends in the apparatus depth direction. In the first embodiment, as an example, the plate thickness of the end of the support member 116 in the apparatus depth direction (thickness T1 in FIG. 2A) is 4 [mm], and the apparatus depth of the support member 116 is as follows. The length in the direction is 100 [mm].

  Further, as shown in FIG. 2B, in a state where the support member 116 is supported inside the cylinder 108, the support member 116 on the opposite side of the separation space 116A across the axial center F of the cylinder 108 is sandwiched. A groove 118 extending in the apparatus depth direction is formed on the outer peripheral surface 120.

  Further, as shown in FIG. 2A, in a state where the support member 116 is not supported inside the cylindrical body 108 (free state), the support member 116 is separated from the separation space 116A when viewed from the apparatus depth direction. It is formed symmetrically with respect to an axis C passing through the groove 118.

  Specifically, the support member 116 is formed by connecting a circular arc portion 116C on the right side in the drawing and a circular hole portion 116D on the left side in the drawing by a groove 118. Further, the radius R1 (see FIG. 2A) of the outer peripheral surface 120 of the arc portions 116C and 116D of the support member 116 in the free state when viewed from the apparatus depth direction is the inner radius of the cylindrical body 108 when viewed from the apparatus depth direction. It is the same as or larger than the radius R2 (see FIG. 2B) of the peripheral surface 108A.

  Furthermore, the separation distance K (see FIG. 2A) in the separation space 116A of the support member 116 in the free state is the separation distance K (see FIG. It is longer than (B).

  Further, the thickness of the bottom plate 118A of the groove 118 (thickness T2 in FIG. 2A) is the same in the depth direction of the device, and in the first embodiment, as an example, it is 1 [mm]. Yes. Further, as shown in FIG. 1B, the groove depth of the groove 118 of the support member 116 in the free state changes in the apparatus depth direction. In other words, in a state where the support member 116 is supported inside the cylindrical body 108, the distance between the shaft center F and the bottom plate 118A (L5 in FIG. 2B) changes the groove depth in the apparatus depth direction. ing.

  Here, the groove depth is the distance from the outer peripheral surface 120 to the bottom plate 118A of the groove 118, and is the groove depth D shown in FIG. Note that the contour line L10 of the groove 118 is regarded as a straight line and measured.

  Further, the thickness of the bottom plate 118A is the same in the apparatus depth direction.

  Specifically, the bottom plate 118A of the groove 118 is bent at the center side in the apparatus depth direction. Furthermore, in a cross section orthogonal to the apparatus width direction, a part on one side in the apparatus depth direction with respect to the bent part J and a part on the other side in the apparatus depth direction with respect to the bent part J are flat. Yes. Then, the groove depth on the center side in the apparatus depth direction in the groove portion 118 (groove depth D1 in FIG. 1B) is the groove depth on both ends in the apparatus depth direction in the groove portion 118 (grooves in FIG. 1B). It is deeper than depth D2). In the first embodiment, as an example, the groove depth D1 is about 0.2 [mm] deeper than the groove depth D2.

(Function)
Next, the operation of the support member 116 will be described by a process of supporting the support member 116 inside the cylindrical body 108.

  When the support member 116 is supported inside the cylindrical body 108, the support member 116 is gripped, and the bottom plate 118A of the groove 118 is elastically deformed so that the separation distance K is shortened. Thereby, the support member 116 is bent, and the support member 116 is inserted into the cylindrical body 108 in the bent state. Further, the gripping force for gripping the support member 116 is released. When the gripping force is released, the outer peripheral surface 120 of the support member 116 presses the inner peripheral surface 108A of the cylindrical body 108 by the elastic restoring force of the elastically deformed bottom plate 118A. In this state, the support member 116 is pushed into the center side of the cylindrical body 108.

  As a result, as shown in FIG. 4, the outer peripheral surface 120 of the support member 116 is in contact with the inner peripheral surface 108A of the cylindrical body over the depth direction of the apparatus (the axial direction of the cylindrical body 108). Is pressed (see FIG. 4). Then, the support member 116 is supported by the cylindrical body 108.

  Next, the operation of the support member 116 will be described from the viewpoint of the support member 116 suppressing the vibration of the cylindrical body 108.

  When charging the surface of the image carrier 56, a superimposed voltage obtained by superimposing an AC voltage (1 kHz to 2 kHz) on a DC voltage is applied to the shaft portion 58 </ b> A of the charging roll 58 (see FIG. 4). An alternating electric field is generated between the charging roll 58 and the image carrier 56 by the alternating voltage that forms the superimposed voltage. Thereby, a periodic (2 kHz to 4 kHz) electrostatic attraction force is generated between the image carrier 56 and the charging roll 58. For this reason, a force that periodically changes (vibrates) the cross section of the cylinder 108 acts on the cylinder 108. However, a support member 116 that presses the inner peripheral surface 108 </ b> A of the cylindrical body 108 with the outer peripheral surface 120 is supported inside the cylindrical body 108. For this reason, even if the force with which the cross section of the cylinder 108 changes periodically acts on the cylinder 108, the vibration of the cylinder 108 is suppressed.

  Here, the stronger the elastic restoring force of the elastically deformed bottom plate 118A, the stronger the pressing force pressing the inner peripheral surface 108A of the cylindrical body 108 with the outer peripheral surface 120, and the vibration of the cylindrical body 108 is suppressed by the support member 116. . In other words, the thicker the bottom plate 118A of the groove 118 is, the stronger the pressing force pressing the inner peripheral surface 108A of the cylindrical body 108 with the outer peripheral surface 120 is, and the vibration of the cylindrical body 108 is suppressed.

  On the other hand, when the cross section of the cylinder 108 changes periodically, the cross section of the support member 116 also changes periodically. In the support member 116, the strain concentrates on the bottom plate 118 </ b> A that is thinner than other portions. Further, distortion of the bottom plate 118A causes vibration absorption due to internal damping, and vibration of the cylinder 108 is suppressed. In other words, the thinner the bottom plate 118A is, the more concentrated the strain is on the bottom plate 118A, and the vibration of the cylinder 108 is suppressed. That is, when the plate thickness is greater than a predetermined thickness, distortion does not concentrate on the bottom plate 118A, and vibration absorption due to internal damping does not occur.

  Next, with regard to the action of the support member 116, the support member 116 according to the comparative example with respect to the pressing force with which the outer peripheral surface 120 of the support member 116 presses the inner peripheral surface 108 </ b> A of the cylindrical body 108 and the internal attenuation due to the distortion of the bottom plate 118 </ b> A This will be described in comparison with 300.

  First, the support member 300 according to the comparative embodiment will be described. Note that the support member 300 will be described mainly with respect to portions different from the support member 116.

  As shown in FIGS. 7A and 7B, the groove depth of the groove portion 308 of the support member 300 (the groove depth D3 in FIG. 7B) does not change in the apparatus depth direction. Specifically, the groove depth on the center side in the apparatus depth direction in the groove portion 308 is the same as the groove depth on both end sides in the apparatus depth direction in the groove portion 308. The bottom plate 308A of the groove 308 is not formed with a bent portion, and the bottom plate 308A has a flat plate shape in a cross section orthogonal to the apparatus width direction.

  Further, the thickness of the bottom plate 308 </ b> A of the support member 300 is the same as the thickness of the bottom plate 118 </ b> A of the support member 116. Further, the groove depth D3 of the groove portion 308 of the support member 300 is the same in the apparatus depth direction.

  First, the pressing force with which the outer peripheral surface 120 presses the inner peripheral surface 108 </ b> A of the cylindrical body 108 will be examined.

  As shown in FIG. 1B, the groove depth of the groove 118 of the support member 116 changes in the apparatus depth direction. In other words, the position of the bottom 118A of the groove 118 in the vertical direction of the device changes in the depth direction of the device.

  On the other hand, as shown in FIG. 7B, the groove depth of the groove portion 308 of the support member 300 does not change in the apparatus depth direction. And in the cross section orthogonal to the apparatus width direction, 118 A of bottom plates of the groove part 118 are made into flat form. The thickness of the bottom plate 308A of the groove portion 308 is the same as the thickness of the bottom plate 118A of the groove portion 118.

  That is, the sectional secondary moment of the bottom plate 118A considered when the bottom plates 118A and 308A are elastically deformed so that the separation distance K is shortened is larger than the sectional secondary moment of the bottom plate 308A. For this reason, the elastic restoring force of the bottom plate 118A is stronger than the elastic restoring force of the bottom plate 308A.

  Thus, the pressing force with which the outer peripheral surface 120 of the support member 116 presses the inner peripheral surface 108A of the cylinder 108 is compared with the pressing force with which the outer peripheral surface 120 of the support member 300 presses the inner peripheral surface 108A of the cylinder 108. And getting stronger.

  Next, internal attenuation due to distortion of the bottom plates 118A and 308A between both ends in the width direction will be considered.

  As described above, the thickness of the bottom plate 118A in the groove 118 of the support member 116 is the same as the thickness of the bottom plate 308A in the groove 308 of the support member 300.

  For this reason, the internal attenuation caused by the distortion of the bottom plates 118A and 308A is the same in the support member 116 and the support member 300. In other words, when the bottom plate 118A is distorted, vibration absorption due to internal damping occurs, and the vibration of the cylinder 108 is suppressed. When the bottom plate 308A is distorted, vibration absorption due to internal damping occurs, and the vibration of the cylinder 108 occurs. The degree of suppression is the same.

(Summary)
As described above, in the support member 116, as compared with the case where the support member 300 is used, the pressing force that presses the inner peripheral surface of the cylindrical body 108 is increased while maintaining vibration absorption due to internal damping.

  Further, since the pressing force that presses the inner peripheral surface 108 </ b> A of the cylindrical body 108 becomes strong, the vibration of the cylindrical body 108 is suppressed as compared with the case where the support member 300 is used.

  Further, since the thickness of the bottom plate 118A of the groove portion 118 is not increased, as described above, the bottom plate 118A is distorted to absorb vibration due to internal damping, and the degree to which the vibration of the cylinder 108 is suppressed, and the bottom plate The distortion of 308A causes vibration absorption due to internal damping, and the degree to which the vibration of the cylinder 108 is suppressed is the same.

  For example, when the support member 116 is molded by injection molding, a slide mold may be used to mold the inside of the support member 116. Here, as described above, the groove portion 118 is formed on the outer peripheral surface 120, and the groove depth on the center side in the apparatus depth direction in the groove portion 118 is deeper than the groove depth on both end sides in the device depth direction in the groove portion 118. Yes. For this reason, the support member 116 is formed by injection molding by dividing the slide mold into one side in the apparatus depth direction and the other side in the apparatus depth direction at the center in the apparatus depth direction.

  Further, in the image holding member 56, the vibration of the cylinder 108 is suppressed, so that the quality of the toner image formed on the image holding member 56 is suppressed from being lowered.

  Further, with respect to the image forming apparatus 10, the quality degradation of the output image is suppressed by suppressing the quality degradation of the toner image formed on the image holding member 56.

Second Embodiment
Next, an example of a support member, an image carrier, and an image forming apparatus according to the second embodiment of the present invention will be described with reference to FIG. In addition, about the same member as 1st Embodiment, the same code | symbol is attached | subjected, the description is abbreviate | omitted, and a different part from 1st Embodiment is mainly demonstrated.

  As shown in FIG. 8B, the plate thickness of the bottom plate 218A in the groove portion 218 of the support member 216 according to the second embodiment is the same in the apparatus depth direction. The groove depth on the center side in the apparatus depth direction (D4 in FIG. 8B) is deeper than the groove depth on both sides in the apparatus depth direction in the groove portion 218 (D5 in FIG. 8B). The bottom plate 218A of the groove 218 is curved when viewed from the device width direction. In the second embodiment, as an example, the groove depth D4 is about 0.2 [mm] deeper than the groove depth D5.

  The operation of the second embodiment is the same as that of the first embodiment.

<Third Embodiment>
Next, an example of a support member, an image carrier, and an image forming apparatus according to a third embodiment of the present invention will be described with reference to FIG. In addition, about the same member as 1st Embodiment, the same code | symbol is attached | subjected, the description is abbreviate | omitted, and a different part from 1st Embodiment is mainly demonstrated.

  As shown in FIG. 9B, the plate thickness of the bottom plate 318A in the groove portion 318 of the support member 316 according to the third embodiment is the same in the apparatus depth direction. And the groove depth of the groove part 318 repeats increase / decrease in an apparatus depth direction.

  Specifically, the bottom plate 318A of the groove portion 318 has a zigzag shape in a cross section orthogonal to the apparatus width direction, and is formed by alternately bending the flat plate. In the third embodiment, as an example, the deepest groove depth D6 is about 0.2 [mm] deeper than the shallowest groove depth D7.

  Thus, as in the first embodiment, the pressing force that presses the inner peripheral surface 108A of the cylindrical body 108 as compared with the case where only the groove depth of the central portion in the groove portion is deeper than other portions. Becomes stronger. Moreover, it becomes difficult to mold the support member 316 by injection molding. About another effect | action, it is the same as that of 1st Embodiment.

<Fourth embodiment>
Next, an example of a support member, an image carrier, and an image forming apparatus according to a fourth embodiment of the present invention will be described with reference to FIG. In addition, about the same member as 3rd Embodiment, the same code | symbol is attached | subjected, the description is abbreviate | omitted, and a different part from 3rd Embodiment is mainly demonstrated.

  As shown in FIG. 10B, the groove depth of the groove portion 418 of the support member 416 according to the fourth embodiment repeatedly increases and decreases in the apparatus depth direction.

  Specifically, the bottom plate 418A of the groove portion 418 has a wave shape in which a convex circular hole and a concave arc are continuous in a cross section orthogonal to the apparatus width direction, and the convex curved portion and the concave curved portion Are formed alternately. The operation of the fourth embodiment is the same as that of the third 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. This will be apparent to those skilled in the art. For example, in the above embodiment, the grooves 118, 218, 318, 418 are formed on the outer peripheral surface 120 of the support members 116, 216, 316, 416, but may be formed on the inner peripheral surface.

  In the above-described embodiment, the outer peripheral surface 120 of the support members 116, 216, 316, and 416 presses the inner peripheral surface 108A of the cylindrical body 108 over the apparatus depth direction. In 416, the outer peripheral surface of at least both ends in the apparatus depth direction may press the inner peripheral surface 108A of the cylindrical body 108.

  In the above embodiment, one support member 116, 216, 316, 416 is supported inside the cylinder 108, but two or more support members 116, 216, 316, 416 may be supported.

DESCRIPTION OF SYMBOLS 10 Image forming apparatus 56 Image holding body 58 Charging roll (an example of charging device)
60 exposure device 62 developing device 64 transfer roll (an example of transfer device)
108 cylindrical body 108A inner peripheral surface 116 support member 116A separation space (an example of a separation portion)
118 Groove 120 Outer peripheral surface 216 Support member 218 Groove 316 Support member 318 Groove 416 Support member 418 Groove

Claims (3)

Supported inside the cylinder constituting the image carrier,
It is an arc shape in which a spacing portion extending in the axial direction of the cylindrical body is formed in a part in the circumferential direction,
A groove portion whose groove depth is repeatedly increased and decreased in the axial direction is formed on the outer peripheral surface along the axial direction,
A support member that is supported inside the cylinder by pressing the inner peripheral surface of the cylinder at at least both ends in the axial direction by elastically deforming the bottom plate of the groove. A cylindrical body having a toner image formed on its surface;
The support member according to claim 1, which is supported inside the cylindrical body,
An image carrier comprising: The image carrier according to claim 2,
A charging device for charging the image carrier;
An exposure device that exposes the charged image carrier to form an electrostatic latent image;
A developing device for developing an electrostatic latent image formed on the surface of the image carrier as a toner image;
A transfer device for transferring a toner image formed on the surface of the image carrier to a recording medium;
An image forming apparatus comprising:

Images