JP5494878B1 - Image forming unit and image forming apparatus - Google Patents

Abstract

An image carrier and an image forming apparatus capable of suppressing vibration generated in the image carrier.
Since the other end side of the image carrier 56 is a sliding bearing, when the image carrier 56 vibrates, the other end side vibrates with a free end. In the image holding body 56, the contact member 116 is arranged inside the cylinder 108 so that the center of gravity G of the contact member 116 is arranged on the other end side of the cylinder 108 from the central portion H of the cylinder 108. . As the mass on the other end side of the image holding body 56 increases, the shaking on the other end side of the image holding body 200 is suppressed. By suppressing the shaking on the other end side of the image carrier 56, the vibration generated in the image carrier 56 is suppressed.
[Selection] Figure 1

Description

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

  The image forming apparatus described in Patent Literature 1 includes a sliding contact member that contacts an inner wall surface of a photosensitive drum (image holding member) and presses the inner wall surface with a predetermined force. The charging noise is reduced by the sliding contact member.

JP 2000-315036 A

  An object of the present invention is to suppress vibration generated in an image carrier.

An image forming unit according to a first aspect of the present invention is a cylindrical body that holds an image on a surface thereof, and is fixed to one end side of the cylindrical body in the axial direction of the cylinder, and a rotational force is transmitted from a driving source. Support member that is fixed to the other end side in the axial direction in the cylindrical body and has a gap between the outer peripheral surface of the cylindrical shaft portion and is rotatably supported by the shaft portion And between the transmission member and the support member and fitted into the cylindrical body and supported by the cylindrical body, and the center of gravity position in the axial direction is greater than the central portion of the cylindrical body in the axial direction. An image carrier having a contact member positioned on the end side, and a charging device for charging the surface of the cylindrical body of the image carrier, and the one end side of the image carrier has a fixed end. The other end side is a free end whose movement amount is restricted .

The image forming unit according to claim 2 of the present invention is an image forming unit according to claim 1, wherein the contact member has a plurality equipped, the combined center of gravity position formed by a plurality of said contact members in the axial direction The cylindrical body is located on the other end side from the central portion in the axial direction.

The image forming unit according to claim 3 of the present invention is an image forming unit according to claim 1 or 2, wherein the contact member is to be disposed only on the other side from the central portion of the cylindrical body Features.

According to a fourth aspect of the present invention, there is provided an image forming apparatus having a cylindrical shape that holds an image on a surface thereof, and is fixed to one end side in the axial direction of the cylindrical body in the cylindrical body, and a rotational force is transmitted from a driving source. Support member fixed to the other end side in the axial direction in the cylindrical body and having a gap between the outer peripheral surface of the columnar shaft portion and rotatably supported by the shaft portion And between the transmission member and the support member and fitted into the cylindrical body and supported by the cylindrical body, and the center of gravity position in the axial direction is greater than the central portion of the cylindrical body in the axial direction. An image carrier having a contact member located on the end side, and a drive source that is disposed on one end side in the axial direction of the image carrier and generates a rotational force transmitted to the cylindrical body via the transmission member And arranged on the other end side in the axial direction of the image holding body so that the support member can be rotated. A cylindrical shaft portion to be held; a charging device that charges the surface of the image carrier; an exposure device that exposes the charged surface of the image carrier to form an electrostatic latent image; and A developing device that develops the electrostatic latent image formed on the surface as a toner image, and the image carrier has a fixed end on the one end side and a free end on which the movement amount is regulated. characterized in that that.

According to the image forming unit of the first aspect of the present invention, the vibration generated in the image holding member is suppressed as compared with the case where the center of gravity of the contact member is located at one end side from the central portion in the axial direction of the cylindrical body. Can do.

According to the image forming unit of claim 2 of the present invention, the vibration generated in the image carrier is more effective than the case where the center of gravity of the plurality of contact members is located at one end side from the central portion in the axial direction of the cylinder. Can be suppressed.

According to the image forming unit of claim 3 of the present invention, the vibration generated in the image holding member is effectively suppressed as compared with the case where the contact member is not disposed only on the other end side from the central portion of the cylindrical body. can do.

According to the image forming apparatus of the fourth aspect of the present invention, the sound generated by the vibration of the image holding member is generated as compared with the case where the center of gravity of the contact member is located at one end side from the central portion in the axial direction of the cylindrical body. Can be suppressed.

(A) (B) The image holding body which concerns on 1st Embodiment of this invention is shown, It is sectional drawing which cut | disconnected the image holding body in the axial orthogonal direction, and sectional drawing cut | disconnected in the axial direction. (A) (B) (C) The perspective view and sectional view which showed the contact member arrange | positioned inside the image carrier which concerns on 1st Embodiment of this invention, and the contact member arrange | positioned inside the image carrier It is sectional drawing which showed. FIG. 2 is a cross-sectional view illustrating the image holding body according to the first embodiment of the present invention, in which the image holding body is cut in the axial direction. 3 is a diagram illustrating a deformation mode of an image carrier according to a comparative example with respect to the image carrier according to the first embodiment of the present invention. It is drawing which showed the frequency response of the image holding body which concerns on the comparative example with respect to the image holding body which concerns on 1st Embodiment of this invention with the graph. 4 is a graph showing a vibration mode during resonance of an image carrier according to a comparative example with respect to the image carrier according to the first embodiment of the present invention. 1 is a schematic configuration diagram illustrating an image forming unit used in an image forming apparatus 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) The image holding body which concerns on 2nd Embodiment of this invention is shown, It is sectional drawing which cut | disconnected the image holding body in the axial orthogonal direction, and sectional drawing cut | disconnected in the axial direction.

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

(overall structure)
As shown in FIG. 8, 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. Further, the image forming apparatus 10 includes a manual sheet feeding unit 90 that manually feeds the sheet member P.

[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 conveying unit 16 is disposed on the downstream side in the conveying direction of the sheet member P with respect to the delivery roll 32 (hereinafter simply referred to as “downstream side in the conveying direction”), and separates and conveys the sheet members P one by one. A separation roll 34 is provided.

  Further, in the conveyance path 28, the sheet member P is stopped once at the downstream side in the conveyance direction with respect to the separation roll 34, and the alignment roller 36 that sends the sheet member P to a transfer position T described later at a predetermined timing. Is arranged.

  Further, a discharge roll 76 that discharges the sheet member P on which the image is formed by the image forming unit 20 to a discharge unit 74 formed above the image forming unit 20 is disposed on the terminal end side of the conveyance path 28. .

  On the other hand, in order to form images on both sides of the sheet member P, a duplex conveying unit 78 that reverses the front and back of the sheet member P is provided on the side of the apparatus main body 10A. The duplex conveying unit 78 includes a reversing path 82 through which the sheet member P conveyed by reversing the discharge roll 76 is fed. Further, a plurality of conveying rolls 84 are arranged along the reversing path 82, and the sheet member P conveyed by these conveying rolls 84 is conveyed again to the alignment roll 36 with the front and back sides reversed. ing.

[Manual Feeder]
Further, a foldable manual sheet feeding unit 90 is provided next to the duplex conveying unit 78. The manual paper feed unit 90 includes a manual paper feed member 92 that can be opened and closed. Further, a sheet feeding roll 94 for conveying the sheet member P fed from the opened manual sheet feeding member 92 and a plurality of conveyance rolls 96 are provided in the manual sheet feeding unit 90, and are conveyed by the conveyance roll 96. The sheet member P is conveyed to the alignment roll 36.

[Original reading section]
On the other hand, the original reading unit 22 provided on the upper side of the image forming apparatus 10 has a read original G carried on the platen glass 42 on the read original G conveyed by the automatic original conveying apparatus 40 that conveys the read original G. A light source 44 for irradiating light is provided.

  Further, the original reading unit 22 has a full-rate mirror 46 that reflects the reflected light that is irradiated from the light source 44 and reflected from the read original G in a direction parallel to the platen glass 42, and the reflected light that is reflected by the full-rate mirror 46 is downward. The half-rate mirror 48 that reflects to the platen, the half-rate mirror 50 that reflects and reflects the reflected light reflected by the half-rate mirror 48 in a direction parallel to the platen glass 42, and the reflected light that is folded by the half-rate mirror 50 are incident. And an imaging lens 52 are provided.

  In addition, the document reading unit 22 includes a photoelectric conversion element 54 that converts the reflected light imaged by the imaging lens 52 into an electrical signal, and further performs image processing on the electrical signal converted by the photoelectric conversion element 54. An image processing unit 24 is provided.

  The light source 44, the full rate mirror 46, the half rate mirror 48, and the half rate mirror 50 are movable along the platen glass 42. When reading the read original G placed on the platen glass 42, the read original G placed on the platen glass 42 while moving the light source 44, the full rate mirror 46, the half rate mirror 48 and the half rate mirror 50. The reflected light reflected from the read original G is imaged on the photoelectric conversion element 54.

  When reading the read document G conveyed by the automatic document conveying device 40, the light source 44, the full rate mirror 46, the half rate mirror 48 and the half rate mirror 50 are stopped and the reading conveyed by the automatic document conveying device 40 is performed. The light source 44 irradiates the original G with light, and the reflected light reflected from the read original G forms an image on the photoelectric conversion element 54.

(Image forming part)
As shown in FIG. 7, the image forming unit 20 includes exposure light on the image carrier 56, a charging roll 58 that charges the surface of the image carrier 56, and the surface of the image carrier 56 that is charged based on image data. And an exposure device 60 (see FIG. 8) that forms an electrostatic latent image and a developing device 62 that develops the electrostatic latent image and visualizes it as a toner image.

  Further, the image forming unit 20 includes a transfer roll 64 that transfers the toner image formed on the surface of the image holding member 56 to the sheet member P conveyed along the conveyance path 28, a heating roll 66H, and a pressure roll 66N. And a fixing device 66 (see FIG. 8) that heats and pressurizes the toner image on the sheet member P to fix it on the sheet member P, and the toner remaining on the image carrier 56 after the toner image is transferred. And a cleaning blade 68 that scrapes off the image carrier 56 to clean the image carrier 56.

  As shown in FIG. 8, a toner cartridge 72 connected to the developing device 62 through a supply pipe (not shown) is disposed obliquely above the exposure device 60. The toner cartridge 72 is filled with toner to be supplied to the developing device 62 through a supply pipe.

  In this configuration, the sheet member P fed from the alignment roll 36 is conveyed to a transfer position T constituted by the image holding body 56 and the transfer roll 64, and is sandwiched between the image holding body 56 and the transfer roll 64. Be transported. As a result, the toner image formed on the image carrier 56 is transferred to the sheet member P.

  Here, the image carrier 56, the charging roll 58, the developing device 62, and the cleaning blade 68 constitute an image forming unit 70, and the image forming unit 70 is detachable from the apparatus main body 10A. .

  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 has been applied uniformly charges the surface of the image carrier 56 uniformly 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 or fed from the manual sheet feeding member 92 to the transport path 28 is determined by the alignment roll 36. Sent to the transfer position T at the same timing. 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 surface of the sheet member P.

  The toner image transferred to the sheet member P is fixed to the sheet member P when the sheet member P passes between a heating roll 66H and a pressure roll 66N provided in the fixing device 66. Then, the sheet member P with the toner image fixed on the surface is discharged to the discharge portion 74 by the discharge roll 76.

  On the other hand, when an image is also formed on the back surface of the sheet member P, the discharge roller 76 is reversed without discharging the sheet member P to the discharge unit 74, and the sheet member P on which the toner image is formed is reversed. Send to path 82. As a result, the front and back of the sheet member P are reversed, and the transport roll 84 transports the sheet member P to the alignment roll 36 again.

  This time, the toner image is transferred to the back surface of the sheet member P at the transfer position T, and the sheet member P on which the toner image is transferred to the back surface is discharged to the discharge unit 74 in the above-described procedure.

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

[Charging roll]
As shown in FIG. 3, the charging roll 58 extends in the depth direction of the apparatus, has a shaft portion 58A formed of a metal material (for example, stainless steel), and a cylindrical shape into which the shaft portion 58A is inserted. The roll part 58B shape | molded by this.

  Further, both end sides 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. Further, 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 to the shaft portion 58A from a power source (not shown).

(Image carrier)
As shown in FIG. 3, the image holding body 56 includes a cylindrical cylinder 108 extending in the apparatus depth, and the cylinder 108 in the apparatus depth direction (the same direction as the axial direction of the cylinder 108 in the present embodiment). A transmission member 110 fixed to one end side (upper side in the figure) and a support member 112 fixed to the other end side (lower side in the figure) in the apparatus depth direction in the cylinder 108 are provided. Furthermore, the image holding body 56 includes a contact member 116 that is disposed inside the cylinder 108 and suppresses vibration of the cylinder 108.

  The cylinder 108 is obtained by forming a photosensitive layer on the outer surface of a base material formed by cylindrically molding a metal material (for example, aluminum).

  The transmission member 110 is formed into 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 on the axial center F of the cylindrical body 108. A plurality (two in FIG. 3) 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 support member 112 is formed into 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, a cylindrical through hole 112 </ b> A is formed in the support member 112 on the axial center F of the cylindrical body 108.

  As shown in FIG. 1A, the contact member 116 is supported by the cylinder 108 in contact with the inner peripheral surface 108 </ b> A of the cylinder 108. As shown in FIG. 1B, the contact member 116 is fitted inside the cylinder 108, and the center of gravity J of the contact member 116 is the center of the cylinder 108 in the apparatus depth direction in the apparatus depth direction. It is arranged so as to be located on the other end side (lower side in the figure) of the cylindrical body 108 from H. The contact member 116 is disposed only on the other end side of the cylindrical body 108 from the central portion H.

  Specifically, the contact member 116 is formed of a resin material (for example, ABS resin (acrylonitrile, butadiene, styrene)), and a part of the contact member 116 is spaced apart in the circumferential direction as shown in FIGS. 116A is formed, and a cylindrical shape (C-shape) extending in the apparatus depth direction is formed. Further, in a state where the contact member 116 is disposed inside the cylindrical body 108, as shown in FIG. 2C, the contact member 116 on the opposite side of the separating portion 116A across the axial center F of the cylindrical body 108 is sandwiched. On the outer peripheral surface 118, a groove 116B extending in the apparatus depth direction is formed.

  In addition, on the outer peripheral surface 118 of the contact member 116, the outer peripheral surface 118A on one side and the outer peripheral surface 118B on the other side across the groove 116B have the same shape (arc shape) as the inner peripheral surface 108A of the cylindrical body 108. (See FIGS. 2B and 2C). Further, as shown in FIGS. 2B and 2C, the separation distance (distance K in the drawing) in the separation portion 116 </ b> A in a state where the contact member 116 is not disposed inside the cylindrical body 108 is the contact member 116. Is longer than the case where it is arranged inside the cylinder 108.

  In this configuration, when the contact member 116 is disposed inside the cylindrical body 108, the contact member 116 is gripped and the contact member 116 is bent by deforming the groove 116B so that the separation distance of the separation portion 116A is shortened. . In this state, the contact member 116 is inserted into the cylindrical body 108 to release the gripping force. Thereby, the outer peripheral surface 118 of the contact member 116 is in contact with the inner peripheral surface 108 </ b> A of the cylindrical body 108, and the contact member 116 is supported by the cylindrical body 108.

[Others]
As shown in FIG. 3, a motor 122 as an example of a drive source that generates a rotational force transmitted to the image carrier 56 (transmission member 110) is disposed on one end side of the image carrier 56 in the apparatus depth direction. Has been.

  A main body 122A of the motor 122 is attached to a plate-like frame 124 disposed in the apparatus main body 10A (see FIG. 8). Further, the motor shaft portion 122B of the motor 122 extends on the axial center F of the cylindrical body 108 and passes through the through hole 126A formed in the housing 126 of the image forming unit 70 (see FIG. 7). 110A is inserted. Further, a plate-like bracket 128 that is bent and inserted into the recess 110B of the transmission member 110 is fixed to the outer peripheral surface of the motor shaft portion 122B. Thereby, the transmission member 110 is assembled | attached integrally (with no backlash) with respect to the motor shaft part 122B. The transmission member 110 transmits the rotational force transmitted from the motor 122 to the transmission member 110 to the cylindrical body 108.

  On the other hand, a shaft member 130 having a shaft portion 130C that rotatably supports the image carrier 56 (support member 112) is disposed on the other end side of the image carrier 56 in the apparatus depth direction.

  The shaft member 130 is formed of a resin material (for example, ABS), and a pedestal portion 130A that is attached to the inner surface 126B of the housing 126, and a step portion 130B that is disposed on the image carrier 56 side through the step from the pedestal portion 130A. And have. Further, the shaft member 130 has the above-described columnar shaft portion 130 </ b> C that extends from the step portion 130 </ b> B onto the axial center F of the cylindrical body 108 and is inserted into the through hole 112 </ b> A of the support member 112.

  The support member 112 functions as a so-called sliding bearing with respect to the shaft portion 130C, and a gap is provided between the inner peripheral surface of the through hole 112A and the outer peripheral surface of the shaft portion 130C.

  In this configuration, when the motor 122 is operated, the motor shaft 122B rotates. The rotation of the motor shaft portion 122 </ b> B is transmitted to the cylinder body 108 through the bracket 128 and the transmission member 110 fixed to one end side of the cylinder body 108. Then, the support member 112 fixed to the other end side of the cylindrical body 108 rotates with respect to the shaft portion 130 </ b> C, so that the image holding body 56 rotates about the axis center F.

(Effects of main components)
Next, functions of the image carrier 56, the charging roll 58, and the like will be described.

  When the motor 122 is operated, the image carrier 56 rotates. When the image carrier 56 rotates, the charging roll 58 is driven to rotate. In order to charge a photosensitive layer (not shown) of the image carrier 56, a superimposed voltage obtained by superimposing an AC voltage on a DC voltage is applied from a power source to the shaft portion 58 </ b> A of the charging roll 58.

  An alternating electric field is generated between the charging roll 58 and the image carrier 56 by the alternating voltage that constitutes the superimposed voltage. Thereby, a periodic electrostatic attraction force is generated between the image carrier 56 and the charging roll 58.

  Here, an image carrier 200 as a comparative example having the same configuration as that of the image carrier 56 of the present embodiment except that the contact member 116 is not provided will be described.

  FIG. 4 exaggerates the deformation state accompanying the vibration of the image carrier 200 obtained by simulation when a periodic electrostatic attraction force is generated between the charging roll 58 and FIG.

  One end side (upper side in the figure) of the image holding body 200 is regarded as a fixed end because the transmission member 110 fixed to one end side of the cylindrical body 108 is integrally assembled with the motor shaft portion 122B. (See FIG. 3). On the other hand, with respect to the other end side (lower side in the figure) of the image holding body 200, the inner peripheral surface of the through hole 112A of the support member 112 fixed to the other end side of the cylindrical body 108 and the outer peripheral surface of the shaft portion 130C. Since an air gap is provided between them, it is regarded as a free end whose amount of movement is restricted (see FIG. 3). Thus, as shown in FIG. 4, the image carrier 200 vibrates as a beam member having one end side as a fixed end and the other end side as a free end. FIG. 4 shows a deformed state when the image carrier 200 vibrates in the primary mode.

  FIG. 5 shows a graph of the frequency response of the image carrier 200. Specifically, the vertical axis represents amplitude and the horizontal axis represents frequency. From this graph, the image carrier 200 resonates and vibrates in the first order mode, resonates and vibrates in the second order mode, resonates and vibrates in the third order mode, and resonates and vibrates in the fourth order mode. It can be seen that there are frequencies that resonate and frequencies that resonate and vibrate in the fifth order mode. That is, depending on the frequency of the alternating voltage that constitutes the superimposed voltage applied to the charging roll 58, the image carrier 200 resonates and vibrates.

  Furthermore, the graph of FIG. 6 shows the deformation state of the image carrier 200 that vibrates in the primary mode to the fifth mode. Specifically, the vertical axis indicates the amplitude, the horizontal axis indicates the position in the axial direction of the image carrier 200 when the central portion H in the axial direction of the image carrier 200 is “0”, and the left side of the graph is On the one end side of the image carrier 200, the right side of the graph shows the other end side of the image carrier 200. From the respective deformed states, it can be seen that the other end side of the image carrier 200 is greatly shaken compared to the one end side. This is because the other end side is regarded as a free end as described above.

  However, in the image carrier 56 of the present embodiment, the cylindrical body is arranged such that the gravity center position G of the contact member 116 is disposed on the other end side (lower side in the drawing) of the cylindrical body 108 from the central portion H of the cylindrical body 108. A contact member 116 is disposed inside 108.

  For this reason, when the mass on the other end side of the image holding body 56 is increased, the shaking on the other end side of the image holding body 200 is suppressed.

  Further, by suppressing the shaking on the other end side of the image carrier 56, vibration generated in the image carrier 56 when the surface of the image carrier 56 is charged by the charging roll 58 is suppressed.

  Further, by suppressing the vibration generated in the image holding body 56, the sound generated by the vibration of the image holding body 56 is suppressed.

  Further, by suppressing the vibration generated in the image holding body 56, the deterioration of the quality of the image output from the image forming apparatus 10 is suppressed.

  Further, since the contact member 116 is disposed only on the other end side of the tubular body 108 from the central portion H in the axial direction of the tubular body 108, the contact member is disposed across the apparatus depth direction (axial direction) of the tubular body 108. As compared with the case, an increase in the mass of the image carrier 56 is suppressed. Furthermore, the vibration generated in the image holding body 56 is effectively suppressed as compared with the case where the contact member is disposed in the apparatus depth direction (axial direction) of the cylinder 108.

<< Second Embodiment >>
Next, an example of an image forming unit 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 FIGS. 9A and 9B, three contact members 152 are arranged side by side in the apparatus depth direction inside the cylindrical body 108 of the image carrier 150 according to the second embodiment. . In the contact member 152 according to the second embodiment, only the length in the apparatus depth direction is shortened with respect to the contact member 116 according to the first embodiment. A combined center of gravity position L determined by the positions of the three contact members 152 and the respective center of gravity positions is located on the other end side from the central portion H of the cylindrical body 108. About an effect | action, it is the same as that of 1st 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 first embodiment, the contact member 116 is positioned at the other end side of the cylindrical body 108 from the central portion H of the cylindrical body 108 so that the center of gravity J of the contact member 116 is located at the other end side of the cylindrical body 108. Although only the other end side is disposed, it is sufficient that the center of gravity J of the contact member 116 is located on the other end side of the cylindrical body 108 from the central portion H, and a part of the contact member is one end side of the cylindrical body 108 from the central portion H May be arranged.

  Further, although not particularly described in the first and second embodiments, the shape of the groove 116B formed in the contact members 116 and 152 is U-shaped regardless of whether it is rectangular or V-shaped. Etc.

  Although not specifically described in the first and second embodiments, the antinodes of the image carriers 56 and 150 that vibrate by resonating the contact members 116 and 152 in a specific mode (the amplitude is in the surrounding area). You may arrange | position in the position which becomes large compared with. Thereby, the vibration which arises in the image holding bodies 56 and 150 is suppressed effectively.

  Moreover, in the said 2nd Embodiment, although the three contact members 152 were inserted in the inside of the cylinder 108, two may be sufficient and four or more may be sufficient.

  Moreover, in the said 2nd Embodiment, although the three contact members 152 were made into the same shape, a mutually different shape may be sufficient.

  Further, although not particularly described in the above embodiment, the thickness of the contact members 116 and 152 may be partially changed.

DESCRIPTION OF SYMBOLS 10 Image forming apparatus 56 Image holding body 56 Image holding body 58 Charging roll (an example of charging apparatus)
60 exposure device 62 developing device 108 cylinder 110 transmission member 112 support member 116 contact member 122 motor (an example of drive source)
130C Shaft 150 Image carrier 152 Contact member

Claims (4)

A cylindrical body that holds an image on the surface thereof, a transmission member that is fixed to one end of the cylinder in the axial direction and that transmits a rotational force from a driving source, and the axial direction of the cylinder A support member that is fixed to the other end side of the cylinder and has a gap between the outer peripheral surface of the cylindrical shaft portion and is rotatably supported by the shaft portion, and between the transmission member and the support member , is fitted inside the tubular member is supported by the tube body, image holding with a contact member positioned other end side from the central part center of gravity position in the axial direction in the axial direction of the tubular member Body,
A charging device for charging the surface of the cylindrical body of the image carrier,
The image holding unit is an image forming unit in which the one end side is a fixed end and the other end side is a free end whose movement is restricted. A plurality of the contact members are provided,
2. The image forming unit according to claim 1, wherein a combined barycentric position constituted by a plurality of the contact members in the axial direction is located on the other end side from the central portion of the cylindrical body in the axial direction . The image forming unit according to claim 1, wherein the contact member is disposed only on the other end side from the central portion of the cylindrical body . A cylindrical body that holds an image on the surface thereof, a transmission member that is fixed to one end side in the axial direction of the cylindrical body in the cylindrical body, and that transmits a rotational force from a driving source, and the axial direction in the cylindrical body A support member that is fixed to the other end side of the cylinder and has a gap between the cylindrical shaft portion and the outer peripheral surface of the columnar shaft portion, and is rotatably supported by the shaft portion, and between the transmission member and the support member A contact member that is fitted into the cylindrical body and supported by the cylindrical body, and whose center of gravity in the axial direction is located on the other end side from a central portion in the axial direction of the cylindrical body. Body,
A driving source that is disposed on one end side in the axial direction of the image holding body and generates a rotational force transmitted to the cylindrical body via the transmission member;
A columnar shaft portion which is disposed on the other end side in the axial direction of the image holding body and rotatably supports the support member;
A charging device for charging the surface of the image carrier;
An exposure device that exposes the surface of the charged image carrier to form an electrostatic latent image; and
A developing device that develops an electrostatic latent image formed on the surface of the image carrier as a toner image,
The image holding apparatus is an image forming apparatus in which the one end side is a fixed end and the other end side is a free end whose movement amount is restricted .

Images