JP2013041174A - Image holding device, and image forming apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image holding device that suppresses, when holding parts for holding a main body part of a charging member are provided only on both sides of the main body part, contact failure between the main body part and an image holding body, and an image forming apparatus.SOLUTION: When an image holding body 12 rotates (operates), a control unit 66 moves a support member 50 to a first position. A main body part 52 is bent to be convex toward the upstream side in a rotation direction of the image holding body 12. However, the main body part 52 deforms along a rotation shaft direction of the image holding part 52 because of friction generated between the main body part 52 and the image holding body 12. Accordingly, contact failure between the main body part 52 and the image holding part 12 can be suppressed.

Description

  The present invention relates to an image carrier device and an image forming apparatus including the same.

  Patent Document 1 describes a charging device having a charging roller (main body portion) made of a hollow elastic material that does not have a rotation support shaft (holding portion). The charging roller contacts the surface of the photosensitive drum (image holding member) and rotates following the rotation of the photosensitive drum. The regulating member for determining the driven rotation position of the charging roller and supplying power to the charging roller has a space larger than the free shape of the charging roller, and has a regulating surface for regulating the charging roller during the driven rotation.

JP2010-2583

  An object of the present invention is to suppress poor contact between a main body and an image carrier when the holding portions that hold the main body of the charging member are set only on both ends of the main body.

  An image carrier device according to a first aspect of the present invention includes an image carrier on which an electrostatic latent image is formed on a surface while rotating, a cylindrical main body formed of an elastic member, and both ends of the main body. And a charging member that charges the surface of the image carrier, the main body being in contact with the surface of the image carrier and being rotated following the image carrier. And a support member that rotatably supports the pair of holding portions so that the main body portion is convex toward the upstream side in the rotation direction of the image holding body.

  The image carrier device according to claim 2 of the present invention is the image carrier device according to claim 1, wherein the support member holds the main body so that the main body is convex toward the upstream side in the rotation direction of the image carrier. The main body is supported so as to be movable between a first position for supporting the holding portion and a second position for supporting the holding portion so as to be along the rotation axis direction of the image holding body. To do.

  The image carrier device according to claim 3 of the present invention is the image carrier device according to claim 2, wherein the support member is moved between a first position and a second position, and the image carrier is operated. The moving member is controlled to move the supporting member to the first position, and when the image holding body is stopped, the moving member is controlled to move the supporting member. And a control unit for moving to the second position.

  According to a fourth aspect of the present invention, in the image carrier device according to the second aspect, the support member is movable by rotating between the first position and the second position. A biasing member that biases the support member so that the support member is disposed at the second position, and the biasing member is caused by a force acting on the main body portion by rotating the image holding body; The position of the rotation shaft that rotatably supports the support member is determined so that the support member moves to the first position against the urging force.

  An image carrier device according to a fifth aspect of the present invention is the image carrier device according to any one of the first to fourth aspects, wherein the main body portion is disposed downstream of the charging member in the rotation direction of the image carrier. A power supply member that applies a voltage to the charging member in contact with the surface of the charging member is provided.

  An image carrier device according to a sixth aspect of the present invention is the image carrier device according to any one of the first to fourth aspects, wherein the main body portion is located downstream of the charging member in the rotation direction of the image carrier. A cleaning member for cleaning the main body portion in contact with the surface of is provided.

  An image forming apparatus according to a seventh aspect of the present invention is formed on a surface of the image carrier device according to any one of the first to sixth aspects and an image carrier provided in the image carrier device. And a developing device that visualizes the electrostatic latent image as a toner image.

  According to the image carrier device of the first aspect of the present invention, the support member supports the main body portion of the charging member as compared with the case where the support member supports the main body portion of the charging member along the rotation axis direction of the image carrier. In the case where the holding portions to be held are set only on both end sides of the main body portion, poor contact between the main body portion and the image holding body can be suppressed.

  According to the image carrier device of claim 2 of the present invention, the support member is compared with the case where the support member always supports the pair of holders so that the main body portion is convex toward the upstream side in the rotation direction of the image carrier. And it can control that distortion arises in a main part.

  According to the image carrier device of the third aspect of the present invention, the moving member can be easily moved to the first position or the second position as compared with the case where the moving member for moving the support member is not provided. The support member can be moved.

  According to the image carrier device of claim 4 of the present invention, the rotation shaft that supports the support member so that the support member moves to the first position by the force applied to the main body when the image carrier rotates. Compared to the case where the position is not determined, the support member can be moved to the first position without using the drive source when the image carrier is operating.

  According to the image carrier device of claim 5 of the present invention, as compared with the case where the power supply member in contact with the surface of the main body is not provided on the downstream side in the rotation direction of the image carrier with respect to the charging member, When the image carrier is operating, deformation of the main body can be suppressed.

  According to the image carrier device of claim 6 of the present invention, as compared with the case where the cleaning member in contact with the surface of the main body is not provided on the downstream side in the rotation direction of the image carrier with respect to the charging member, When the image carrier is operating, deformation of the main body can be suppressed.

  According to the image forming apparatus of the seventh aspect of the present invention, the quality of the output image is improved as compared with the case where the image carrier apparatus described in any one of the first to sixth aspects is not provided. Can do.

It is the top view which showed the image holding body unit which concerns on this 1st Embodiment of this invention. It is the top view which showed the image holding body unit which concerns on this 1st Embodiment of this invention. It is the top view which showed the image holding body unit which concerns on this 1st Embodiment of this invention. 1 is a schematic configuration diagram illustrating an image forming apparatus including an image carrier unit according to the first embodiment of the present invention. It is the top view which showed the image holding body unit which concerns on this 2nd Embodiment of this invention. It is the top view which showed the image holding body unit which concerns on this 2nd Embodiment of this invention. It is the top view which showed the image holding body unit which concerns on this 2nd Embodiment of this invention. It is the side view which showed the image holding body unit which concerns on this 3rd Embodiment of this invention. It is the side view which showed the image holding body unit which concerns on this 4th Embodiment of this invention.

  An example of the image carrier device and the image forming apparatus according to the first embodiment of the present invention will be described with reference to FIGS. In addition, arrow UP shown in a figure shows the vertical direction upper direction.

(overall structure)
As shown in FIG. 4, the image forming apparatus 10 includes an image carrier 12, a charging member 14 that uniformly charges the surface of the image carrier 12, and laser light to the image carrier 12 based on image data. An exposure device 16 that forms an electrostatic latent image by irradiation, a developing device 18 that selectively transfers toner to the electrostatic latent image and visualizes it as a toner image, and a recording medium supplied along the conveyance path 20 A transfer roll 22 for transferring the toner image on the surface of the image holding member 12 to the sheet member P as a toner image, a fixing device 24 for heating and pressurizing the toner image on the sheet member P to fix the toner image on the sheet member P, and a toner image And a cleaning device 26 for cleaning toner remaining on the image carrier 12 after being transferred.

  The image forming apparatus 10 is covered with a main body side cover 10B and a top plate 10A. A shaft 10C that rotatably connects the top plate 10A to the main body side cover 10B is provided at the upper end corner of the main body side cover 10B. The top plate 10A is centered on the shaft 10C in the direction of arrow A. By rotating, the inside of the image forming apparatus 10 is opened.

  Here, the charging member 14, the cleaning device 26, and the image carrier 12 are configured as an image carrier unit 28 as an example of an image carrier device. The image carrier unit 28 can be attached to and detached from a main body frame (not shown) inside the image forming apparatus 10 by opening the top plate 10 </ b> A of the image forming apparatus 10. Details of the image carrier unit 28 will be described later.

  Further, on the side of the image forming apparatus 10, a manual sheet feeding table 32 that can manually feed the sheet member P to the image forming unit 31 formed by the image carrier 12 and the transfer roll 22. I have. This manual paper feed tray 32 is provided with a half-moon shaped delivery roll 34. Further, a separation roll 36 for separating the sheet members P to be sent one by one is provided on the opposite side of the sheet member P with respect to the delivery roll 34.

  The separation roll 36 is pivotally supported by a support member (not shown) provided at both ends, and is further biased toward the delivery roll 34 by a biasing force of a coil spring provided inside the support member. . With this configuration, when the delivery roll 34 rotates, the sheet member P placed on the manual paper feed tray 32 is sent to the image forming unit 31 one by one by the delivery roll 34 and the separation roll 36.

  A sheet feeding device 40 that feeds the sheet members P one by one is provided below the image forming apparatus 10. The sheet feeding device 40 includes a sheet feeding member 41 on which a plurality of sheet members P are placed. The sheet members P stacked on the sheet feeding member 41 are sequentially taken out by a take-out roll 42. Further, the sheet member P is conveyed one by one by the sheet feeding roll 44 that rotates and the separation roll 46 provided on the sheet feeding member 41.

  Further, a plurality of conveyance rolls 48 that convey the sheet member P along the conveyance path 20 of the sheet member P are provided, and the downstream side in the conveyance direction of the sheet member P along the conveyance path 20 (hereinafter simply referred to as the downstream side). The sheet member P is conveyed to the above.

  Further, the fixing device 24 described above is provided on the downstream side of the image forming unit 31, and the fixing device 24 includes a heating roll 24H and a pressure roll 24N. Then, the sheet member P passes between the heating roll 24H and the pressure roll 24N, so that the toner image on the sheet member P is fixed to the sheet member P.

  Further, on the downstream side of the fixing device 24, a discharge roll 56 for discharging the sheet member P on which the toner image is fixed to the upper surface of the top plate 10A is provided.

  In the image forming apparatus 10 configured as described above, an image is formed as follows.

  First, the charging member 14 to which a voltage is applied uniformly charges the surface of the image carrier 12 with a predetermined potential. Subsequently, the exposure device 16 exposes the charged surface of the image carrier 12 based on image data read by a scanner (not shown) or data input from the outside, and an electrostatic latent image is formed on the surface of the image carrier 12. Form.

  That is, an electrostatic latent image corresponding to image data is formed on the image carrier 12 by turning on and off the laser of the exposure device 16 based on video data supplied from a control device (not shown). Further, the electrostatic latent image is visualized as a toner image by toner supplied from the developing device 18.

  Therefore, the sheet member P taken out from the paper feed member 41 by the take-out roll 42 is delivered to the transport roll 48 one by one by the paper feed roll 44 and the separation roll 46 and sent out to the transport path 20. The sheet member P sent to the conveyance path 20 passes through the image forming unit 31 formed between the image carrier 12 and the transfer roll 22, and the toner image is transferred to the sheet member P. The transferred toner image is fixed on the sheet member P by passing between a heating roll 24H and a pressure roll 24N provided in the fixing device 24, and is discharged onto the top surface of the top plate 10A by the discharge roll 56. The

(Main part configuration)
Next, the configuration of the image carrier unit 28 will be described.

  FIG. 1 illustrates a plan view of the image carrier unit 28 (an arrow view when the image carrier 12 is viewed from above in the vertical direction). As shown in FIG. 1, the image carrier unit 28 is in contact with the surface of the image carrier 12 and rotates following the image carrier 12 to charge the surface of the image carrier 12 uniformly. And a pair of support members 50 that rotatably support the charging member 14.

  Specifically, the charging member 14 includes a cylindrical main body 52 formed by an elastic member (for example, a rubber foam member) that is in contact with the surface of the image carrier 12 and extends along the rotation axis direction of the image carrier 12. I have.

  Further, the charging member 14 includes a pair of columnar holding portions 54 that are inserted into the main body portion 52 from the end surface of the main body portion 52 at the front end side and hold both end sides of the main body portion 52. Further, a power supply means (not shown) for applying a voltage to the main body 52 via the holding portion 54 is provided.

  Further, the pair of support members 50 provided on both ends of the charging member 14 includes a bearing 58 that rotatably supports the base end side of the holding portion 54 and a shaft member that rotatably supports the main body 50A of the support member 50. And 60 respectively.

  Further, the rotation axis direction of the shaft member 60 is disposed so as to be orthogonal to the rotation axis direction of the image holding body 12. By rotating the support member 50 around the shaft member 60, the support member 50 supports the holding portion 54 so that the main body portion 52 is convex toward the upstream side in the rotation direction of the image holding body 12. It is possible to move between a first position (see FIG. 2) and a second position (see FIG. 1) where the main body 52 supports the holding portion 54 along the rotation axis direction of the image holding body 12. ing.

  Further, stepping motors 62 are provided as examples of moving members that move the respective support members 50 between the first position and the second position. When the image carrier 12 is rotating (operating), the stepping motor 62 is controlled to move the support member 50 to the first position, and when the image carrier 12 is stopped, A control unit 66 that controls the stepping motor 62 to move the support member 50 to the second position is provided.

(Function)
Next, the operation of the image carrier unit will be described.

  As shown in FIG. 1, when the image carrier 12 is not rotating, the control unit 66 controls the stepping motor 62 to arrange (move) the support member 50 to the second position. By arranging the support member 50 at the second position, the main body 52 is arranged in a direction along the rotation axis direction of the image carrier 12.

  On the other hand, as shown in FIG. 2, when the image carrier 12 rotates (operates), the control unit 66 controls the stepping motor 62 to move the support member 50 to the first position. As the support member 50 moves to the first position, the main body 52 tends to protrude toward the upstream side in the rotation direction of the image carrier 12 (arrow C in the figure).

  However, as shown in FIG. 3, a frictional force is generated between the main body 52 in contact with the outer surface of the image carrier 12 and the rotating image carrier 12. Due to this frictional force, the main body 52 that is about to be deformed so as to protrude toward the upstream side in the rotation direction of the image carrier 12 is further deformed. Specifically, due to this frictional force, the main body 52 that is in contact with the image forming range (range D in the figure) of the image carrier 12 is deformed so as to be along the rotational axis direction of the image carrier 12.

  The charging member 14 is driven to rotate with respect to the image carrier 12 in a state in which the main body 52 in the image forming range (range D in the figure) of the image carrier 12 is deformed along the rotation axis direction of the image carrier 12. Then, the image forming range (range D in the figure) on the image carrier 12 is uniformly charged.

  When the rotation of the image carrier 12 is stopped, the control unit 66 controls the stepping motor 62 to move the support member 50 to the second position, as shown in FIG. As the support member 50 moves to the second position, the main body 52 is arranged along the rotational axis direction of the image carrier 12.

  As described above, when the image carrier 12 rotates, the support member 50 is moved to the first position, and an image forming range (range in the figure) in the image carrier 12 is caused by frictional force with the image carrier 12. The main body 52 in contact with D) is deformed so as to follow the rotation axis direction of the image carrier 12. Thereby, the contact failure of the main-body part 52 and the image holding body 12 is suppressed.

  In addition, since the contact failure between the main body 52 and the image carrier 12 is suppressed, the charging failure of the image carrier 12 is suppressed.

  When the rotation of the image carrier 12 is stopped, the main body 52 is arranged along the rotation axis direction of the image carrier 12 by moving the support member 50 to the second position. . For this reason, the permanent deformation of the main body 52 is suppressed.

  In addition, since the holding portions 54 are provided only on both ends of the main body portion 52, the cost is lower than a configuration in which the holding portions are provided as a whole along the longitudinal direction of the main body portion.

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

  As shown in FIG. 5, the image holding unit 70 according to the second embodiment is not provided with a stepping motor and a controller that controls the stepping motor. Instead, a spring member 74 is provided as an example of a biasing member that biases the support member 72 so as to place the support member 72 in the second position.

  Further, the rotation shaft 76 that supports the main body 72A of the support member 72 so that the support member 72 is moved to the first position by the force (frictional force) applied to the main body portion 52 by the rotation of the image holding body 12. The position is determined.

  Specifically, the rotation shaft 76 is provided on the upstream side in the rotation direction of the image carrier 12 with respect to the bearing 58 in a plan view. Further, in a state where the support member 72 is disposed at the second position (see FIG. 5), the rotary shaft 76, one end of the spring member 74 in a tension state fixed to the support member 72, and the frame member 78 are fixed. The other end of the spring member 74 is arranged on a straight line in plan view.

  As shown in FIG. 6, with this configuration, when the image carrier 12 rotates, the main body 52 protrudes downstream in the rotational direction of the image carrier 12 due to the frictional force generated between the image carrier 12 and the image carrier 12. . The support member 72 tries to rotate around the rotation shaft 76, but the support member 72 hits a stopper (not shown) and does not move from the state where it is arranged at the second position.

  By deforming the main body portion 52 to be convex, a tensile force that pulls the holding portion 54 acts on the pair of holding portions 54 in the axial direction of the holding portion 54 (arrow F in the figure).

  As shown in FIG. 7, when a tensile force acts on the holding portion 54, the support member 72 rotates in the direction of arrow G around the rotation shaft 76 against the urging force of the spring member 74, and Move to the position. Further, the main body 52 in contact with the image forming range (the range D in the figure) of the image holding body 12 by the frictional force generated between the rotating image holding body 12 and the main body 52 is provided on the image holding body 12. Deforms along the rotation axis direction.

  As shown in FIG. 5, when the rotation of the image carrier 12 stops, the support member 50 is moved to the second position by the biasing force of the spring member 74.

  As described above, the support member 72 moves from the second position to the first position without using a drive source.

Other operations are the same as those in the first embodiment.
<Third Embodiment>
Next, an example of an image carrier apparatus and an image forming apparatus according to the 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 and the description is abbreviate | omitted.

  As shown in FIG. 8, on the downstream side in the rotation direction of the image carrier 12 with respect to the charging member 14 according to the third embodiment, a voltage is applied to the charging member 14 in contact with the surface of the main body 52. An auxiliary power supply member 92 as an example of the power supply member to be applied is disposed.

  Specifically, the auxiliary power supply member 92 extends along the rotational axis direction of the image carrier 12 and has a rectangular cross section orthogonal to the longitudinal direction. Thus, when the image carrier 12 is in operation, the main body 52 that is about to be deformed downstream in the rotation direction of the image carrier 12 abuts against the auxiliary power supply member 92, so that the main body 52 rotates in the rotation direction of the image carrier 12. It is suppressed that it deform | transforms excessively to the downstream of this.

  In addition, when the image carrier 12 rotates, the deformed main body 52 contacts the auxiliary power supply member 92, so that power supply failure to the charging member 14 is suppressed.

Other operations are the same as those in the first embodiment.
<Fourth embodiment>
Next, an example of an image carrier apparatus and an image forming apparatus according to the fourth 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 and the description is abbreviate | omitted.

  As shown in FIG. 9, on the downstream side in the rotation direction of the image carrier 12 with respect to the charging member 14 according to the fourth embodiment, the main body 52 is in contact with the surface of the main body 52 while being rotated in rotation with the main body 52. A columnar cleaning member 98 for cleaning the portion 52 is provided.

  As a result, when the image carrier 12 rotates, the deformed main body 52 contacts the cleaning member 98, so that the main body 52 is prevented from being excessively deformed downstream in the rotation direction of the image carrier 12. .

  Other operations are the same as those in the first embodiment.

  Although the present invention has been described in detail with respect to specific embodiments, the present invention is not limited to such embodiments, and various other embodiments are possible within the scope of the present invention. It is clear to the contractor. For example, in the second embodiment, the support member 72 is moved to the second position by the biasing force of the spring member 74, but the support member is moved to the second position by the restoring force of the main body without using the spring member 74. You may move to.

  In the third embodiment, the auxiliary power supply member 92 that supplementarily applies a voltage to the charging member 14 on the downstream side in the rotation direction of the image carrier 12 with respect to the charging member 14 has been described as an example. A regular power supply member may be provided downstream of the charging member in the rotation direction of the image carrier.

  Although not particularly described in the above embodiment, when the image carrier is rotated in the reverse direction, the main body protrudes toward the downstream side in the rotation direction (normal rotation direction) of the image carrier. As described above, the support member may support the holding portion.

  Although not specifically described in the third and fourth embodiments, a gap between the main body 52 and the auxiliary power supply member 92 or the cleaning member 98 may be provided in advance. It may be set so that there is no gap in the state along the rotation axis direction of the holding body 12.

DESCRIPTION OF SYMBOLS 10 Image forming apparatus 12 Image holding body 14 Charging member 28 Image holding body unit (an example of an image holding body apparatus)
50 support member 52 main body portion 54 holding portion 62 stepping motor (an example of a moving member)
66 Control unit 72 Support member 76 Rotating shaft 92 Auxiliary power supply member (an example of a power supply member)
98 Cleaning member

Claims (7)

An image carrier on which an electrostatic latent image is formed on the surface while rotating;
A cylindrical main body formed of an elastic member; and a pair of holding parts for holding both ends of the main body. The main body is in contact with the surface of the image holding body and is opposed to the image holding body. A charging member that is driven to rotate and charges the surface of the image carrier;
A support member that rotatably supports the pair of holding portions such that the main body portion is convex toward the upstream side in the rotation direction of the image holding body;
An image carrier apparatus comprising:   The support member includes a first position that supports the holding unit such that the main body is convex toward the upstream side in the rotation direction of the image holding body, and the main body is a rotation axis of the image holding body. The image holding device according to claim 1, wherein the image holding device is supported so as to be movable between a second position for supporting the holding portion along the direction. A moving member that moves the support member between a first position and a second position;
When the image carrier is operating, the moving member is controlled to move the support member to the first position, and when the image carrier is stopped, the moving member is controlled. And a controller that moves the support member to the second position;
An image carrier apparatus according to claim 2, comprising: The support member is movable by rotating between a first position and a second position,
A biasing member that biases the support member so that the support member is disposed at the second position is provided,
The support member is rotatably supported so that the support member moves to the first position against the urging force of the urging member by the force acting on the main body by rotating the image holding body. The image carrier apparatus according to claim 2, wherein a position of a rotating shaft to be determined is determined.   5. The power feeding member for applying a voltage to the charging member in contact with the surface of the main body is provided downstream of the charging member in the rotation direction of the image carrier. The image carrier device according to 1.   The cleaning member which cleans the said main-body part in contact with the surface of the said main-body part is provided in the downstream of the rotation direction of the said image holding body with respect to the said charging member. Image carrier device. An image carrier device according to any one of claims 1 to 6,
A developing device for visualizing the electrostatic latent image formed on the surface of the image carrier provided in the image carrier device as a toner image;
An image forming apparatus comprising:

Images