JP2006251639A - Apparatus and system for image forming - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To realize an image forming apparatus capable of appropriately applying transfer voltage to an intermediate transfer body and decreasing abnormal sound. <P>SOLUTION: The image forming apparatus has: the rotatable intermediate transfer body being an intermediate medium in the case of transferring a developer image to a medium; a conductive roller rotating with the rotation of the intermediate transfer body in a state where it abuts on the intermediate transfer body; a bearing made of a resin for bearing the shaft of the roller; a conductive supporting member supporting one end side of the shaft of the roller through the bearing and directly supporting the other end side of the shaft; and a transfer voltage applying part for applying transfer voltage to the intermediate transfer body through the supporting member and the roller. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

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

  Image forming apparatuses such as laser beam printers are already well known. Such an image forming apparatus includes, for example, a photoconductor for carrying a latent image, a developing device for developing a latent image carried on the photoconductor by a developer, and a development formed on the photoconductor by developing the latent image. An intermediate transfer member to which the agent image is transferred, and when an image signal or the like is transmitted from an external device such as a host computer to the control unit, the developing device is positioned at a developing position facing the photosensitive member, The latent image carried on the photosensitive member is developed with a developer in a developing device to form a developer image, and the developer image is transferred to a medium via an intermediate transfer member, and finally the image is formed on the medium. Form.

The image forming apparatus includes a transfer voltage applying unit that applies a transfer voltage to the intermediate transfer member in order to appropriately transfer the developer image to the intermediate transfer member. Furthermore, the image forming apparatus includes a conductive roller that rotates in accordance with the rotation of the intermediate transfer member in contact with the intermediate transfer member, and a conductive support member that supports the roller. The transfer voltage application unit applies a transfer voltage to the intermediate transfer member via the support member and the roller.
JP 11-288179 A

In order for the transfer voltage application unit to apply the transfer voltage to the intermediate transfer member, it is necessary to keep the conductive roller and the conductive support member energized.
Further, since the roller rotates with the rotation of the intermediate transfer member, the roller may be displaced in the axial direction during the rotation and may contact a bearing that receives the roller. In such a case, depending on the material of the bearing, abnormal noise may be generated during contact between the roller and the bearing.
SUMMARY An advantage of some aspects of the invention is that it provides an image forming apparatus that can appropriately apply a transfer voltage to an intermediate transfer member and reduce abnormal noise. .

  In order to solve the above-mentioned problems, a main aspect of the present invention is a rotatable intermediate transfer member serving as an intermediate medium when transferring a developer image to a medium, and the intermediate transfer member in contact with the intermediate transfer member. A conductive roller that rotates as the roller rotates, a resin bearing for receiving the shaft of the roller, and one end side of the shaft of the roller is supported via the bearing, and the other end side of the shaft is supported. An image forming apparatus comprising: a conductive support member that directly supports; and a transfer voltage application unit that applies a transfer voltage to the intermediate transfer body via the support member and the roller. is there.

  Other features of the present invention will become apparent from the description of the present specification and the accompanying drawings.

  At least the following will be made clear by the description of the present specification and the accompanying drawings.

A rotatable intermediate transfer member serving as an intermediate medium when transferring the developer image to the medium, and a conductive roller that rotates with the rotation of the intermediate transfer member in contact with the intermediate transfer member; A resin bearing for receiving the shaft of the roller, a conductive support member for supporting one end side of the shaft of the roller through the bearing, and directly supporting the other end side of the shaft; and the support member And a transfer voltage application unit for applying a transfer voltage to the intermediate transfer body via the roller and the roller.
When the support member directly supports the other end of the shaft of the roller, the roller and the support member are in a state of being energized, so that a transfer voltage can be appropriately applied to the intermediate transfer member. When the support member supports one end of the roller shaft via a resin bearing, it is difficult for the noise to occur when the roller comes into contact with the resin bearing. It becomes possible to do. Therefore, according to the above-described image forming apparatus, it is possible to realize an image forming apparatus that can appropriately apply a transfer voltage to the intermediate transfer member and reduce abnormal noise.

In the image forming apparatus, the intermediate transfer member may be a belt, and the roller may be in contact with an outer peripheral surface of the belt.
When the intermediate transfer member is a belt, the roller in contact with the outer peripheral surface of the belt moves in the axial direction and contacts the bearing in order to rotate the belt inappropriately (for example, meandering rotation). The possibility to do increases. Therefore, the effect of reducing abnormal noise by making the bearing made of resin is more effectively exhibited.

Further, in this image forming apparatus, a protruding member protruding inward of the belt is fixed to an inner peripheral surface of the belt and an end portion in the orthogonal direction orthogonal to the rotation direction of the belt. The image forming apparatus has a tension portion that abuts on an inner peripheral surface of the belt and a central portion in an orthogonal direction orthogonal to the rotation direction, and stretches the belt rotatably. The stretching portion regulates movement of the belt in an orthogonal direction orthogonal to the rotation direction by contacting the projecting member fixed to the belt, and the roller is configured to pass the belt through the belt. The one end side of the roller shaft is the center side of the belt in the orthogonal direction, and the other end side of the roller shaft is in the orthogonal direction. Be on the end side of the belt It may be.
In the case where the stretch portion is in contact with the projecting member and restricts the movement of the belt in the orthogonal direction, the roller easily moves toward the center. This is because when the belt moves in the orthogonal direction due to meandering rotation or the like, the projecting member is caught by the stretched portion, and the end portion of the belt in the orthogonal direction is lifted, and the belt moves to the center side. This is because the moving force acts. Under such circumstances, when a resin bearing is provided on the center side where the roller is easy to move, it is possible to reduce noise more effectively.

In the image forming apparatus, the bearing may be attached to the support member so as to be movable with respect to the support member.
In such a case, the bearing that supports the roller that rotates along with the rotation of the belt moves according to the rotation state of the belt (for example, when the belt rotates in an inclined state, the bearing Move in response to an oblique rotation). When the bearing is moved in this manner, the roller appropriately contacts the belt during the rotation, so that the roller can smoothly rotate.

Further, in this image forming apparatus, the bearing is fitted to the support member on one end side in the longitudinal direction, and a receiving portion that receives the shaft of the roller is arranged on the other end side in the longitudinal direction. A fastening portion fastened to the support member by a fastening member so as to be movable in a crossing direction intersecting the axial direction of the roller with respect to the support member, and the receiving portion is attached to the support member; On the other hand, it may be movable in the crossing direction.
In such a case, the roller can be rotated more effectively and smoothly by moving the receiving portion in the intersecting direction while the roller is rotating.

Further, in this image forming apparatus, the fastened portion is fastened to the support member by the fastening member so as to be movable in the axial direction with respect to the support member, and the receiving portion is The support member may be movable in the axial direction.
In such a case, the roller can be rotated more effectively and smoothly by moving the receiving portion in the axial direction while the roller is rotating.

Further, in this image forming apparatus, the support member includes one end side bent portion for supporting one end side of the shaft of the roller via the bearing, and the other end directly supporting the other end side of the shaft. It is good also as providing a side bending part.
When the two bent portions of the support member support the roller, the support member may improperly support the roller. For example, when the bent portion is not properly bent, the support member supports the roller obliquely. If the roller is improperly supported, the roller does not rotate smoothly. Therefore, in the above case, by making the bearing movable with respect to the support member, the effect of smoothly rotating the roller is more effectively achieved.

In addition, a rotatable intermediate transfer member serving as an intermediate medium when transferring the developer image to the medium, and a conductive roller that rotates with the rotation of the intermediate transfer member in contact with the intermediate transfer member A resin bearing for receiving the shaft of the roller, a conductive support member that supports one end of the shaft of the roller via the bearing, and directly supports the other end of the shaft; A transfer voltage application unit for applying a transfer voltage to the intermediate transfer member via a support member and the roller, the intermediate transfer member is a belt, and the roller is an outer periphery of the belt. A projecting member projecting inward of the belt is fixed to an inner peripheral surface of the belt and an end portion in the orthogonal direction perpendicular to the rotation direction of the belt, The forming apparatus includes an inner peripheral surface of the belt and a direction that is perpendicular to the rotation direction. A tensioning portion that abuts against the central portion in the orthogonal direction and rotatably stretches the belt, and the tensioning portion comes into contact with the projecting member fixed to the belt, The movement of the belt in a direction orthogonal to the rotation direction is restricted, and the roller is provided at a position facing the protruding member via the belt, and the one end side of the roller shaft is The other end side of the shaft of the roller is the end side of the belt in the orthogonal direction, and the bearing is movable with respect to the support member. The bearing is attached to the support member, and the bearing is fitted to the support member at one end in the longitudinal direction, and a receiving portion for receiving the shaft of the roller is disposed at the other end in the longitudinal direction. , Against the support member A fastening portion fastened to the support member by a fastening member so as to be movable in a crossing direction that intersects the axial direction of the roller, and the receiving part is in the crossing direction with respect to the support member; The fastened portion is fastened to the support member by the fastening member so as to be movable in the axial direction with respect to the support member, and the receiving portion is the support member. The support member directly supports one end side bent portion for supporting one end side of the shaft of the roller via the bearing and the other end side of the shaft. An image forming apparatus comprising: the other end side bent portion.
According to such an image forming apparatus, an effect capable of realizing an image forming apparatus capable of appropriately applying a transfer voltage to the intermediate transfer member and reducing abnormal noise is most effectively achieved.

Also, a computer and an image forming apparatus connectable to the computer, wherein the intermediate transfer member is a rotatable intermediate transfer member serving as an intermediate medium when the developer image is transferred to the medium, and is in contact with the intermediate transfer member A conductive roller that rotates as the intermediate transfer member rotates, a resin bearing for receiving the shaft of the roller, and one end side of the shaft of the roller supported via the bearing, An image forming apparatus comprising: a conductive support member that directly supports the other end side of the shaft; and a transfer voltage application unit that applies a transfer voltage to the intermediate transfer member via the support member and the roller. An image forming system comprising:
According to such an image forming system, since the image forming system includes an image forming apparatus capable of appropriately applying a transfer voltage to the intermediate transfer member and reducing noise, an image forming system superior to the conventional one can be provided. It can be realized.

=== Example of Overall Configuration of Image Forming Apparatus ===
Next, an outline of a laser beam printer (hereinafter also referred to as a printer) 10 as an example of the image forming apparatus will be described with reference to FIGS. FIG. 1 is a diagram illustrating main components constituting the printer 10. FIG. 2 is a block diagram showing the control unit. FIG. 3 is a perspective view showing the intermediate transfer unit 60. In FIG. 1, the up and down direction (vertical direction) is indicated by an arrow. For example, the paper feed tray 92 is disposed at the lower part of the printer 10, and the fixing unit 90 is disposed at the upper part of the printer 10. Has been.

  As shown in FIG. 1, the printer 10 according to the present embodiment includes a charging unit 30, an exposure unit 40, a YMCK developing unit 50, and an intermediate transfer unit along the rotation direction of a photoconductor 20 as an example of an image carrier. 60, a photoconductor cleaning unit 75, and further, a secondary transfer unit 80, a fixing unit 90, a display unit 95 which is a liquid crystal panel which provides a notification means to the user, and controls these units to serve as a printer. It has the control unit 100 which manages operation | movement.

  The photoreceptor 20 has a cylindrical conductive substrate and a photosensitive layer formed on the outer peripheral surface thereof, and is rotatable around a central axis. In the present embodiment, the photoreceptor 20 is indicated by an arrow in FIG. Rotate clockwise.

  The charging unit 30 is a device for charging the photoconductor 20, and the exposure unit 40 is a device for forming a latent image on the photoconductor 20 charged by irradiating a laser. The exposure unit 40 includes a semiconductor laser, a polygon mirror, an F-θ lens, and the like, and charges the modulated laser based on an image signal input from a host computer (not shown) such as a personal computer or a word processor. The irradiated photoconductor 20 is irradiated.

  The YMCK developing unit 50 converts the latent image formed on the photoconductor 20 into toner as an example of a developer contained in the developing device, that is, black (K) toner contained in the black developing device 51, magenta development. An apparatus for developing using magenta (M) toner stored in the device 52, cyan (C) toner stored in the cyan developing device 53, and yellow (Y) toner stored in the yellow developing device 54. is there.

  The YMCK developing unit 50 can move the positions of the four developing devices 51, 52, 53, 54 by rotating with the four developing devices 51, 52, 53, 54 mounted. Yes. That is, the YMCK developing unit 50 holds the four developing devices 51, 52, 53, 54 by four holding portions 55a, 55b, 55c, 55d, and the four developing devices 51, 52, 53, 54 is rotatable around the central axis 50a while maintaining the relative position thereof. Each time image formation for one page is completed, it is selectively opposed to the photoconductor 20, and is formed on the photoconductor 20 with the toner accommodated in each developing device 51, 52, 53, 54. The latent images are developed sequentially. Each of the four developing devices 51, 52, 53, and 54 described above is detachably attached to the image forming apparatus main body, more specifically, the holding portions 55a, 55b, 55c, and 55d of the YMCK developing unit 50. It is possible.

  The intermediate transfer unit 60 includes a transfer belt 70 as an example of an intermediate transfer member, an electrode unit 200, and the like. The details of the electrode unit 200 (FIG. 3) will be described later.

  The transfer belt 70 is an intermediate medium when transferring the toner image on the photoreceptor 20 to a recording medium (paper, film, cloth, etc.) as an example of the medium, and transfers the toner (toner image) to the recording medium. Then, the toner (toner image) is rotated while being carried to move the toner (toner image). The transfer belt 70 is an endless belt in which a tin vapor deposition layer is provided on the surface of a PET film, and a semiconductive paint is formed on the surface layer (hereinafter, the semiconductive paint layer is also referred to as a resistance layer 70a (FIG. 3)). It is. As shown in FIG. 3, at one end of the transfer belt 70 in the orthogonal direction (hereinafter also referred to as the belt orthogonal direction) orthogonal to the rotation direction of the transfer belt 70 (the direction indicated by the arrow in FIG. 1). Instead of the resistance layer 70a, an electrode layer 70b is formed along the rotation direction of the transfer belt 70.

  Further, a bead 70c (see FIG. 5) as an example of a protruding member protruding inward of the transfer belt 70 is fixed to both ends of the transfer belt 70 in the inner peripheral surface and in the belt orthogonal direction. The bead 70 c is provided over the entire circumference of the transfer belt 70 along the rotation direction of the transfer belt 70.

  Further, inside the transfer belt 70, a driving roller 71, a driven roller 72, and the like are provided. The driving roller 71 is in contact with the inner peripheral surface of the transfer belt 70 and has a function of rotating the transfer belt 70 at substantially the same peripheral speed as that of the photoreceptor 20. The driven roller 72 is in contact with the inner peripheral surface of the transfer belt and stretches the transfer belt 70 in a rotatable manner. The driven roller 72 is in contact with the central portion of the transfer belt 70 in the belt orthogonal direction, and is provided with a rotating member 73 that can rotate with respect to the driven roller 72 at both axial end portions. The rotating member 73 has a tapered portion 73a on the driven roller 72 side, and the tapered portion 73a contacts the bead 70c, thereby restricting the movement of the transfer belt 70 in the belt orthogonal direction. The driven roller 72 and the rotation member 73 constitute a “stretching portion”.

  The transfer belt 70 is transferred from a transfer bias applying unit 121 (FIG. 2) as an example of a transfer voltage applying unit via a high voltage line 300 (FIG. 3), a connector 301 (FIG. 3), and an electrode unit 200. A primary transfer bias is applied as an example of the voltage. The high voltage line 300 is fixed to one end of the high voltage line 300 and connects the transfer bias applying unit 121 and the electrode unit 200 via a connector 301 attached to the electrode unit 200. The transfer bias applying unit 121 applies a primary transfer bias to the transfer belt 70 in a state where the high voltage line 300 and the electrode unit 200 are connected.

  Further, the transfer belt 70 is in contact with the photoconductor 20, and a primary transfer portion T1 to which the toner image on the photoconductor 20 is transferred to the transfer belt 70 is in contact with the transfer belt 70 and the photoconductor 20. Is formed. When the primary transfer bias is applied to the transfer belt 70 from the transfer bias applying unit 121, an electric field is formed between the transfer belt 70 and the photoconductor 20 in the primary transfer unit T1, and the toner image formed on the photoconductor 20 is transferred. The image is transferred to the transfer belt 70. When the four color toner images are sequentially transferred, a full color toner image is formed on the transfer belt 70.

  The photoconductor cleaning unit 75 is provided between the intermediate transfer unit 60 and the charging unit 30, and has a rubber photoconductor cleaning blade 76 that is in contact with the surface of the photoconductor 20, and is transferred by the intermediate transfer unit 60. After the toner image is transferred onto the belt 70, the toner remaining on the photoreceptor 20 is scraped off and collected by the photoreceptor cleaning blade 76.

  The secondary transfer unit 80 is a device for transferring a single color toner image or a full color toner image formed on the transfer belt 70 to a recording medium. The secondary transfer unit 80 includes a roller that contacts the transfer belt 70, and a toner image on the transfer belt 70 is transferred to a recording medium at a contact portion between the roller and the transfer belt 70. Part T2 is formed. When a secondary transfer bias is applied to the roller, an electric field is formed between the transfer belt 70 and the roller at the secondary transfer portion T2, and the toner image on the transfer belt 70 is transferred to the recording medium. .

  The fixing unit 90 is a device for fusing a single color toner image or a full color toner image transferred on a recording medium to the recording medium to obtain a permanent image.

  As shown in FIG. 2, the control unit 100 includes a main controller 101 and a unit controller 102. An image signal and a control signal are input to the main controller 101, and in response to a command based on the image signal and the control signal. A unit controller 102 controls each of the units and forms an image.

Next, the operation of the printer 10 configured as described above will be described.
First, when an image signal and a control signal from a host computer (not shown) are input to the main controller 101 of the printer 10 via the interface (I / F) 112, the unit controller 102 based on a command from the main controller 101. The photoconductor 20 and the transfer belt 70 are rotated by the control. The photoconductor 20 is sequentially charged by the charging unit 30 at the charging position while rotating.

  The charged area of the photoconductor 20 reaches an exposure position as the photoconductor 20 rotates, and a latent image corresponding to image information of the first color, for example, yellow Y, is formed in the area by the exposure unit 40. . In the YMCK developing unit 50, a yellow developing device 54 that contains yellow (Y) toner is located at a developing position facing the photoconductor 20.

  The latent image formed on the photoconductor 20 reaches the development position as the photoconductor 20 rotates, and is developed with yellow toner by the yellow developing device 54. That is, the yellow developing device 54 visualizes the latent image carried on the photoreceptor 20 as a toner image with toner. As a result, a yellow toner image is formed on the photoreceptor 20.

  The yellow toner image formed on the photoconductor 20 reaches the primary transfer portion T1 as the photoconductor 20 rotates, and is transferred to the transfer belt 70. At this time, a primary transfer bias having a polarity opposite to the charging polarity of the toner is applied to the transfer belt 70. During this time, the photoconductor 20 and the transfer belt 70 are in contact with each other, and the secondary transfer unit 80 is separated from the transfer belt 70.

  The above processing is sequentially executed for each developing device for the second color, the third color, and the fourth color, so that four color toner images corresponding to the respective image signals are transferred to the transfer belt 70. Overlaid and transferred. As a result, a full-color toner image is formed on the transfer belt 70.

  The full-color toner image formed on the transfer belt 70 reaches the secondary transfer portion T2 as the transfer belt 70 rotates, and is transferred to the recording medium by the secondary transfer unit 80. The recording medium is conveyed from the paper feed tray 92 to the secondary transfer unit 80 via the paper feed roller 94 and the registration roller 96. Further, when performing the transfer operation, the secondary transfer unit 80 is pressed against the transfer belt 70 and a secondary transfer bias is applied to the secondary transfer unit 80.

  The full color toner image transferred to the recording medium is heated and pressurized by the fixing unit 90 and fused to the recording medium. On the other hand, after the primary transfer position has passed, the photosensitive member 20 collects the toner adhering to the surface thereof by the photosensitive member cleaning unit 75, and prepares for charging for forming the next latent image.

=== Overview of Control Unit ===
Next, the configuration of the control unit 100 will be described with reference to FIG. The main controller 101 of the control unit 100 is connected to a host computer via an interface 112 and includes an image memory 113 for storing image signals input from the host computer. The unit controller 102 includes units of the apparatus main body (charging unit 30, exposure unit 40, YMCK developing unit 50, intermediate transfer unit 60, photoconductor cleaning unit 75, secondary transfer unit 80, fixing unit 90, and display unit 95). Each unit is controlled based on a signal input from the main controller 101 while detecting a state of each unit by receiving signals from sensors that are electrically connected and provided.

=== Configuration Example of Electrode Unit 200 ===
Next, a configuration example of the electrode unit 200 will be described with reference to FIGS. FIG. 4 is a perspective view showing the electrode unit 200 and its peripheral part. FIG. 5 is a cross-sectional view showing the electrode unit 200 and its periphery. FIG. 6 is a perspective view showing the electrode unit 200. FIG. 7 is a six-sided view showing the roller support sheet metal 230. FIG. 8 is a view showing the stepped screw 240. In FIG. 4, the connector 301 is not attached to the electrode unit 200, unlike FIG. 3 where the connector 301 is attached to the electrode unit 200.

  The transfer bias applying unit 121 described above applies a primary transfer bias to the transfer belt 70 via the electrode unit 200. As shown in FIG. 3, the electrode unit 200 is fixed to the intermediate transfer unit main body 61 at one end side in the belt orthogonal direction. The electrode unit 200 is in contact with the transfer belt 70.

  As shown in FIG. 4, the electrode unit 200 rotates an electrode roller 210 as an example of a conductive roller, a roller bearing 220 as an example of a bearing that rotatably receives the electrode roller 210, and the electrode roller 210. It has a roller support metal plate 230 as an example of a conductive support member that supports it, and a stepped screw 240 as an example of a fastening member for attaching the roller bearing 220 to the roller support metal plate 230.

  The electrode roller 210 is configured to rotate along with the rotation of the transfer belt 70 in a state where the electrode roller 210 is in contact with the outer peripheral surface of the transfer belt 70 (more specifically, the electrode layer 70b). That is, the electrode roller 210 is a driven roller that rotates as the transfer belt 70 rotates. As shown in FIG. 5, the electrode roller 210 is provided at a position facing the bead 70 c with the transfer belt 70 interposed therebetween.

  Further, as shown in FIG. 5, the electrode roller 210 includes a contact portion 211 that is in contact with the outer peripheral surface of the transfer belt 70 and a roller shaft 212 whose outer diameter is smaller than the outer diameter of the corresponding contact portion 211. Yes. The abutting portion 211 is an elastic roller having conductivity, and is made of, for example, a single-foam foam in which carbon as a conductive agent is dispersed in urethane. The roller shaft 212 is made of metal, and one end side 212a in the axial direction is positioned on the center side of the transfer belt 70 in the belt orthogonal direction, and the other end side 212b in the axial direction is the end of the transfer belt 70 in the belt orthogonal direction. It is provided so that it may be located in the side.

  As shown in FIG. 4, the roller bearing 220 is attached to a roller support metal plate 230, and rotatably receives one end side 212 a of the roller shaft 212 of the electrode roller 210. The roller bearing 220 is made of resin, and in this embodiment, is made of polyacetal resin (POM). In addition, as shown in FIG. 5, the roller bearing 220 is fastened to the roller support sheet metal 230 by a stepped screw 240 at one end in the longitudinal direction and a receiving portion 221 that receives the roller shaft 212 at the other end in the longitudinal direction. Each of the fastened portions 222 is provided. As shown in FIG. 5, the receiving portion 221 is formed so as to protrude toward the contact portion 211 of the electrode roller 210, and the fastened portion 222 is opposite to the protruding direction of the receiving portion 221. It is formed to protrude in the direction of.

  The roller support metal plate 230 is made of metal, and as shown in FIG. 5, supports one end side 212a of the roller shaft 212 of the electrode roller 210 via the roller bearing 220, and supports the other end side 212b of the roller shaft 212. Support directly. As shown in FIG. 6, the roller support sheet metal 230 includes a base 231 provided on one end side in the longitudinal direction of the roller support sheet metal 230 (hereinafter also referred to as sheet metal longitudinal direction) and the other end side in the sheet metal longitudinal direction. A roller support portion 232 that is provided and supports the electrode roller 210 and an intermediate portion 233 provided on the center side in the longitudinal direction of the sheet metal.

  As shown in FIG. 6, the base portion 231 includes a first bent portion 235 provided at one end portion of the roller support sheet metal 230 in the short direction (hereinafter also referred to as a sheet metal short direction) and the other end portion in the sheet metal short direction. And a second bent portion 234 provided on the head. Note that the bending direction of the first bent portion 235 is opposite to the bent direction of the second bent portion 234.

  The first bent portion 235 is provided with a connector mounting portion 235a to which the connector 301 (FIG. 3) is mounted. For this reason, the 1st bending part 235 is a site | part used as the connector mounting part 235a. The connector mounting portion 235a is configured such that the connector 301 can be attached and detached. The direction in which the connector 301 is detached from the connector mounting portion 235a is the direction from the other end side to the one end side in the longitudinal direction of the sheet metal, and thus intersects the axial direction of the roller shaft 212 of the electrode roller 210. .

  The second bent portion 234 is provided with a fixing portion 234 a when the roller support metal plate 230 is fixed to the intermediate transfer unit main body 61. For this reason, the 2nd bending part 234 is a site | part used as the fixing | fixed part 234a. The fixing portion 234a has a long hole 234b that fits with the positioning convex portion 64 (FIG. 4) of the intermediate transfer unit main body 61, and a female screw 234c that is fastened to the male screw of the fixing screw 63 (FIG. 4). Then, as shown in FIG. 4, the elongated hole 234b is fitted to the positioning convex portion 64, and the fixing screw 63 is fastened to the female screw, whereby the fixing portion 234a (roller support metal plate 230) is attached to the intermediate transfer unit main body 61. The position is fixed, and the fixing portion 234a (roller support metal plate 230) is fixed to the intermediate transfer unit main body 61. As shown in FIG. 6, the axial direction of the fastened fixing screw 63 is along the axial direction of the roller shaft 212 of the electrode roller 210, and the direction in which the connector 301 is attached to and detached from the connector mounting portion 235a. Crossed.

  As shown in FIG. 5, the roller support portion 232 is provided at one end portion in the sheet metal short direction, and is a third bent portion that is an example of one end side bent portion that supports one end side 212 a of the roller shaft 212 of the electrode roller 210. 236 and a fourth bent portion 237 that is an example of the other end side bent portion that is provided at the other end portion in the sheet metal short direction and supports the other end side 212b of the roller shaft 212.

  The third bent portion 236 includes a fitting hole 236 a (FIG. 7) that fits with the receiving portion 221 of the roller bearing 220. The third bent portion 236 supports the one end side 212 a of the roller shaft 212 via the roller bearing 220 by the receiving portion 221 fitted to the fitting hole 236 a receiving the one end side 212 a of the roller shaft 212. . Note that the diameter of the fitting hole 236 a is larger than the outer diameter of the receiving portion 221.

  As shown in FIG. 7, the fourth bent portion 237 includes a fitting hole 237a. By fitting the other end side 212b of the roller shaft 212 and the fitting hole 237a, the fourth bent portion 237 directly supports the other end side 212b of the roller shaft 212. The fourth bent portion 237 directly supports the other end side 212b, whereby the roller support metal plate 230 and the roller shaft 212 can be energized.

  The intermediate portion 233 is provided between the base portion 231 and the roller support portion 232 so as to be connected to the base portion 231 and the roller support portion 232. Unlike the base portion 231 and the roller support portion 232, the intermediate portion 233 does not include a bent portion at both ends in the sheet metal short direction. Further, as shown in FIG. 7, the intermediate portion 233 includes a notch 233a on one end side in the sheet metal short direction and a notch 233b on the other end side in the sheet metal short direction. Therefore, the width of the intermediate portion 233 in the sheet metal short direction (L1 in FIG. 7) is the width of the base portion 231 in the sheet metal short direction (L2 in FIG. 7) and the width of the roller support portion 232 in the sheet metal short direction. It is smaller than (L3 in FIG. 7). Since the intermediate portion 233 is configured as described above, the intermediate portion 233 is a weakly rigid portion whose rigidity is weaker than the rigidity of the base portion 231 and the roller support portion 232.

  The stepped screw 240 has a function of attaching the roller bearing 220 to the third bent portion 236 of the roller support metal plate 230. A stepped screw 240 shown in FIG. 8 includes a male screw part 241 fastened to a female screw 236 b of a third bent part 236, a shaft part 242 that supports the fastened part 222, and an outer diameter of the screw part 241. A large-diameter portion 243 larger than the diameter.

  Further, the outer diameter of the shaft portion 242 is smaller than the inner diameter of the hole portion of the fastened portion 222. For this reason, the fastened portion 222 is fastened to the roller support metal plate 230 by the stepped screw 240 so that the fastened portion 222 can move in the crossing direction intersecting the axial direction of the electrode roller 210 with respect to the roller support metal plate 230. Further, as described above, the diameter of the fitting hole 236a of the third bent portion 236 is larger than the outer diameter of the receiving portion 221. And when the to-be-fastened part 222 moves to the said crossing direction (namely, along the 3rd bending part 236), the receiving part 221 also moves to the said crossing direction.

  Further, in the axial direction of the shaft portion 242, the length of the shaft portion 242 is larger than the length of the fastened portion 222. For this reason, the fastened portion 222 is fastened to the roller support metal plate 230 by the stepped screw 240 so as to be movable in the axial direction with respect to the roller support metal plate 230. Therefore, when the fastened portion 222 moves in the axial direction of the electrode roller 210, the receiving portion 221 also moves in the axial direction.

  Thus, the roller bearing 220 supporting the electrode roller 210 is attached to the roller support metal plate 230 so as to be movable with respect to the roller support metal plate 230.

  Since the electrode unit 200 is configured as described above, the transfer bias applying unit 121 performs primary transfer to the transfer belt 70 via the high-voltage line 300, the connector 301, the roller support metal plate 230, and the electrode roller 210. Apply a bias.

=== Effectiveness of Printer 10 According to the Present Embodiment ===
The image forming apparatus (printer 10) according to the present embodiment includes a rotatable intermediate transfer body (transfer belt 70) serving as an intermediate medium when a developer image (toner image) is transferred to a medium (recording medium), and a transfer A conductive roller (electrode roller 210) that rotates with the rotation of the transfer belt 70 in contact with the belt 70, and a resin bearing (for receiving the shaft of the electrode roller 210 (roller shaft 212)) A roller bearing 220) and a conductive support member (roller support metal plate 230) that supports one end 212a of the roller shaft 212 of the electrode roller 210 via the roller bearing 220 and directly supports the other end 212b of the roller shaft 212. And a transfer voltage application unit (transfer bias) for applying a transfer voltage (primary transfer bias) to the transfer belt 70 via the roller support metal plate 230 and the electrode roller 210. Has a Kabe 121), the. Accordingly, it is possible to realize the printer 10 that can appropriately apply the primary transfer bias to the transfer belt 70 and reduce abnormal noise. This will be described in detail below.

  In order for the transfer bias applying unit 121 to apply the primary transfer bias to the transfer belt 70 via the roller support sheet metal 230 and the electrode roller 210, the conductive electrode roller 210 and the conductive roller support sheet metal 230 are energized. It is necessary to be in a state. Further, since the electrode roller 210 rotates with the rotation of the transfer belt 70, the electrode roller 210 may be displaced in the axial direction during the rotation and may contact a bearing that receives the electrode roller 210. In such a case, depending on the material of the bearing, noise may be generated during contact between the electrode roller 210 and the bearing. For example, when the roller bearing 220 is made of metal, abnormal noise is likely to occur.

  Therefore, in this embodiment, as shown in FIG. 5, the roller support metal plate 230 supports one end side 212 a of the roller shaft 212 of the electrode roller 210 via the resin roller bearing 220, and The other end side 212b is directly supported. When the roller support sheet metal 230 directly supports the other end 212b of the roller shaft 212, the electrode roller 210 and the roller support sheet metal 230 are energized. It becomes possible to apply a bias appropriately. On the other hand, when the roller support metal plate 230 supports the one end side 212 a of the roller shaft 212 via the resin roller bearing 220, abnormal noise is generated when the electrode roller 210 comes into contact with the roller bearing 220. Since it is difficult, it is possible to reduce the occurrence of abnormal noise.

=== Other Embodiments ===
The image forming apparatus and the like according to the present invention have been described above based on the above embodiment. However, the above embodiment of the present invention is for facilitating understanding of the present invention and limits the present invention. is not. The present invention can be changed and improved without departing from the gist thereof, and the present invention includes the equivalents thereof.

  In the above embodiment, a full color laser beam printer has been described as an example of the image forming apparatus. However, the present invention can be applied to various image forming apparatuses such as a monochrome laser beam printer, a copying machine, and a facsimile.

  In the above-described embodiment, the image forming apparatus including the rotary type developing device has been described as an example. However, the present invention is not limited to this. For example, the present invention can be applied to an image forming apparatus provided with a tandem developing device.

  Furthermore, in the above embodiment, as shown in FIG. 3, the intermediate transfer member is the transfer belt 70 and the electrode roller 210 is in contact with the outer peripheral surface of the transfer belt 70. However, the present invention is not limited to this. Is not to be done. For example, the intermediate transfer member may be a drum.

  When the intermediate transfer member is the transfer belt 70, the transfer belt 70 rotates inappropriately (for example, meandering rotation) as compared with the case where the intermediate transfer member is a drum. There is an increased possibility that the electrode roller 210 in contact with the roller moves in the axial direction thereof and comes into contact with the roller bearing. Therefore, the effect of reducing abnormal noise by making the roller bearing made of resin is more effectively exhibited. Therefore, the above embodiment is more desirable.

Further, in the above embodiment, as shown in FIG. 5, the inner peripheral surface of the transfer belt 70 and an end portion orthogonal to the rotation direction of the transfer belt 70 (hereinafter also referred to as belt orthogonal direction), In this case, a protruding member (bead 70c) protruding inward of the transfer belt 70 is fixed. Further, the printer 10 is in contact with the inner peripheral surface of the transfer belt 70 and the central portion in the belt orthogonal direction to stretch the transfer belt 70 in a rotatable manner (the driven roller 72 and the rotating member). 73). In addition, the stretching portion regulates the movement of the transfer belt 70 in the belt orthogonal direction by contacting the beads 70c fixed to the transfer belt 70. Further, the electrode roller 210 is provided at a position facing the bead 70c with the transfer belt 70 interposed therebetween. One end 212a of the roller shaft 212 of the electrode roller 210 is the center side of the transfer belt 70 in the belt orthogonal direction, and the other end 212b of the roller shaft 212 of the electrode roller 210 is in the belt orthogonal direction. It was decided to be the end side. In such a case, the roller bearing 220 is located on the center side. However, it is not limited to the above. For example, one end side 212a of the roller shaft 212 of the electrode roller 210 is the end side of the transfer belt 70 in the belt orthogonal direction, and the other end side 212b of the roller shaft 212 of the electrode roller 210 is in the belt orthogonal direction. It may be the center side. In such a case, the roller bearing 220 is positioned on the end side.
In the case where the stretch portion (more specifically, the rotation member 73) is configured to abut against the bead 70c and restrict the movement of the transfer belt 70 in the belt orthogonal direction, the electrode roller 210 easily moves to the center side. . This is because when the transfer belt 70 moves in the belt orthogonal direction by meandering rotation or the like, the bead 70c is caught by the rotating member 73 (more specifically, the tapered portion 73a), and the end of the transfer belt 70 in the belt orthogonal direction. This is because the portion is lifted, and a force to move the electrode roller 210 toward the center side acts. Under such circumstances, when the resin roller bearing 220 is provided on the center side where the electrode roller 210 is easy to move, it is possible to reduce noise more effectively. Therefore, the above embodiment is more desirable.

Further, in the above embodiment, as shown in FIG. 4, the roller bearing 220 is attached to the roller support metal plate 230 so as to be movable with respect to the roller support metal plate 230. It is not limited. For example, the roller bearing 220 may be attached to the roller support metal plate 230 so that it cannot move relative to the roller support metal plate 230.
When the roller bearing 220 is movable with respect to the roller support metal plate 230, the roller bearing 220 that supports the electrode roller 210 that rotates as the transfer belt 70 rotates moves according to the rotation state of the transfer belt 70. (For example, when the transfer belt 70 rotates in an oblique state, the roller bearing 220 moves corresponding to the oblique rotation). When the roller bearing 220 moves in this way, the electrode roller 210 properly contacts the transfer belt 70 during its rotation, so that the electrode roller 210 can rotate smoothly. Therefore, the above embodiment is more desirable.

Furthermore, in the above embodiment, as shown in FIG. 5, the roller bearing 220 is fitted to the roller support metal plate 230 on one end in the longitudinal direction and receives the roller shaft 212 of the electrode roller 210. Can be moved to the other end in the longitudinal direction in a crossing direction (hereinafter also referred to as the roller axis crossing direction) intersecting the axial direction of the electrode roller 210 (hereinafter also referred to as the roller axis direction) with respect to the roller support metal plate 230. In other words, each of the fastened portions 222 fastened to the roller support metal plate 230 by a fastening member (stepped screw 240) is provided. The receiving portion 221 is movable in the direction intersecting the roller axis with respect to the roller support metal plate 230. However, it is not limited to the above. For example, the receiving portion 221 may not be able to move in the roller axis crossing direction with respect to the roller support metal plate 230.
However, when the receiving portion 221 is movable in the direction intersecting the roller axis with respect to the roller support sheet metal 230, the receiving portion 221 moves in the direction intersecting the roller axis during the rotation of the electrode roller 210, thereby being more effective. In addition, the electrode roller 210 can be smoothly rotated. Therefore, the above embodiment is more desirable.

Further, in the above embodiment, as shown in FIG. 5, the fastened portion 222 is fastened to the roller support metal plate 230 by the stepped screw 240 so as to be movable in the roller axial direction with respect to the roller support metal plate 230. It was decided that The receiving portion 221 is movable in the roller axial direction with respect to the roller support metal plate 230. However, it is not limited to the above. For example, the receiving portion 221 may not be movable in the roller axial direction with respect to the roller support metal plate 230.
However, when the receiving portion 221 is movable in the roller axial direction with respect to the roller support metal plate 230, the electrode roller 210 can be more effectively rotated smoothly. Therefore, the above embodiment is more desirable.

Further, in the above embodiment, as shown in FIG. 5, the roller support metal plate 230 has one end side bent portion (first end) for supporting the one end side 212 a of the roller shaft 212 of the electrode roller 210 via the roller bearing 220. 3 folds 236) and the other end folds (fourth folds 237) that directly support the other end 212 b of the roller shaft 212, but are not limited thereto. . For example, the roller support metal plate 230 may not include a bent portion that supports the roller shaft 212.
When the two bent portions of the roller support metal plate 230 support the electrode roller 210, the roller support metal plate 230 may improperly support the electrode roller 210. For example, when the bent portion is not properly bent, the roller support metal plate 230 supports the electrode roller 210 obliquely. If the electrode roller 210 is improperly supported, the electrode roller 210 is difficult to rotate smoothly. Therefore, in the above case, by making the roller bearing 220 movable with respect to the roller support metal plate 230, the effect of smoothly rotating the electrode roller 210 is more effectively achieved. Therefore, the above embodiment is more desirable.

=== Configuration of Image Forming System etc. ===
Next, an image forming system according to an embodiment of the present invention will be described with reference to the drawings.

  FIG. 9 is an explanatory diagram showing an external configuration of the image forming system. The image forming system 700 includes a computer 702, a display device 704, a printer 706, an input device 708, and a reading device 710.

  In this embodiment, the computer 702 is housed in a mini-tower type housing, but is not limited thereto. The display device 704 is generally a CRT (Cathode Ray Tube), a plasma display, a liquid crystal display device, or the like, but is not limited thereto. As the printer 706, the printer described above is used. In this embodiment, the input device 708 uses a keyboard 708A and a mouse 708B, but is not limited thereto. In this embodiment, the reading device 710 uses a flexible disk drive device 710A and a CD-ROM drive device 710B. However, the reading device 710 is not limited to this. For example, an MO (Magneto Optical) disk drive device or a DVD (Digital Versatile) is used. Disk) etc. may be used.

  FIG. 10 is a block diagram showing the configuration of the image forming system shown in FIG. An internal memory 802 such as a RAM and an external memory such as a hard disk drive unit 804 are further provided in a housing in which the computer 702 is housed.

  In the above description, the example in which the printer 706 is connected to the computer 702, the display device 704, the input device 708, and the reading device 710 to configure the image forming system has been described. However, the present invention is not limited to this. Absent. For example, the image forming system may include a computer 702 and a printer 706, and the image forming system may not include any of the display device 704, the input device 708, and the reading device 710.

  For example, the printer 706 may have a part of the functions or mechanisms of the computer 702, the display device 704, the input device 708, and the reading device 710. As an example, the printer 706 includes an image processing unit that performs image processing, a display unit that performs various displays, a recording medium attachment / detachment unit for attaching / detaching a recording medium that records image data captured by a digital camera or the like. It is good also as a structure to have.

  The image forming system realized in this way is a system superior to the conventional system as a whole system.

FIG. 2 is a diagram illustrating main components constituting the printer. It is a block diagram which shows a control unit. 3 is a perspective view showing an intermediate transfer unit 60. FIG. It is the perspective view which showed the electrode unit 200 and its peripheral part. It is sectional drawing which showed the electrode unit 200 and its peripheral part. 2 is a perspective view showing an electrode unit 200. FIG. 6 is a six-sided view showing a roller support metal plate 230. It is the figure which showed the stepped screw. 1 is an explanatory diagram showing an external configuration of an image forming system. FIG. 10 is a block diagram illustrating a configuration of the image forming system illustrated in FIG. 9.

Explanation of symbols

10 printer, 20 photoconductor, 30 charging unit, 40 exposure unit,
50 YMCK developing unit, 50a central axis, 51 black developing device,
52 magenta developing device, 53 cyan developing device, 54 yellow developing device,
55a, 55b, 55c, 55d holding part, 60 intermediate transfer unit,
61 intermediate transfer unit main body, 63 fixing screw, 64 positioning convex part,
70 transfer belt, 70a resistance layer, 70b electrode layer, 70c bead,
71 driving roller, 72 driven roller, 73 rotating member, 73a taper part,
75 photoconductor cleaning unit, 76 photoconductor cleaning blade,
80 secondary transfer unit, 90 fixing unit, 92 paper feed tray,
94 paper feed roller, 95 display unit, 96 registration roller,
100 control unit, 101 main controller,
102 unit controller, 112 interface,
113 image memory, 121 transfer bias application unit,
200 electrode unit, 210 electrode roller, 211 abutting part,
212 roller shaft, 212a one end side, 212b the other end side,
220 roller bearing, 221 receiving portion, 222 fastened portion, 222a hole portion,
223 intermediate part, 230 roller support sheet metal, 231 base part, 232 roller support part,
233 Middle part, 233a Notch, 233b Notch,
234 second bent portion, 234a fixing portion, 234b long hole, 234c female screw,
235 first bent portion, 235a connector mounting portion,
236 third bent portion, 236a fitting hole, 236b female thread,
237 fourth bent portion, 237a fitting hole,
240 Stepped screw, 241 Male thread part, 242 Shaft part, 243 Large diameter part,
300 high voltage wire, 301 connector,
700 image forming system, 702 computer, 704 display device,
706 printer, 708 input device, 708A keyboard, 708B mouse,
710 reader,
710A flexible disk drive device,
710B CD-ROM drive device,
802 internal memory, 804 hard disk drive unit,
T1 primary transfer part, T2 secondary transfer part,

Claims (9)

A rotatable intermediate transfer member serving as an intermediate medium when transferring the developer image to the medium;
A conductive roller that rotates as the intermediate transfer member rotates in contact with the intermediate transfer member;
A resin bearing for receiving the shaft of the roller;
A conductive support member that supports one end of the shaft of the roller via the bearing and directly supports the other end of the shaft;
A transfer voltage applying unit for applying a transfer voltage to the intermediate transfer member via the support member and the roller;
An image forming apparatus comprising: The image forming apparatus according to claim 1,
The intermediate transfer member is a belt,
The image forming apparatus, wherein the roller is in contact with an outer peripheral surface of the belt. The image forming apparatus according to claim 2,
A protruding member protruding inward of the belt is fixed to an inner peripheral surface of the belt and an end portion in the orthogonal direction orthogonal to the rotation direction of the belt,
The image forming apparatus has a tension portion that abuts on the inner peripheral surface of the belt and a central portion in the orthogonal direction perpendicular to the rotation direction, and stretches the belt rotatably.
The stretching portion regulates movement of the belt in an orthogonal direction orthogonal to the rotation direction by contacting the protruding member fixed to the belt,
The roller is provided at a position facing the protruding member via the belt,
The one end side of the shaft of the roller is a center side of the belt in the orthogonal direction, and the other end side of the shaft of the roller is an end side of the belt in the orthogonal direction. Forming equipment. The image forming apparatus according to any one of claims 1 to 3,
The image forming apparatus, wherein the bearing is attached to the support member so as to be movable with respect to the support member. The image forming apparatus according to claim 4,
The bearing is fitted with the support member on one end side in the longitudinal direction, and a receiving portion for receiving the shaft of the roller is disposed on the other end side in the longitudinal direction with respect to the support member in the axial direction of the roller. A fastening portion fastened to the support member by a fastening member so as to be movable in a crossing direction intersecting with
The image forming apparatus according to claim 1, wherein the receiving portion is movable in the intersecting direction with respect to the support member. The image forming apparatus according to claim 5, wherein
The fastened portion is fastened to the support member by the fastening member so as to be movable in the axial direction with respect to the support member;
The image forming apparatus, wherein the receiving portion is movable in the axial direction with respect to the support member. An image forming apparatus according to any one of claims 4 to 6,
The support member includes one end side bent portion for supporting one end side of the shaft of the roller via the bearing, and another end side bent portion for directly supporting the other end side of the shaft. An image forming apparatus. A rotatable intermediate transfer member serving as an intermediate medium when transferring the developer image to the medium;
A conductive roller that rotates as the intermediate transfer member rotates in contact with the intermediate transfer member;
A resin bearing for receiving the shaft of the roller;
A conductive support member that supports one end of the shaft of the roller via the bearing and directly supports the other end of the shaft;
A transfer voltage applying unit for applying a transfer voltage to the intermediate transfer member via the support member and the roller;
Have
The intermediate transfer member is a belt,
The roller is in contact with the outer peripheral surface of the belt;
A protruding member protruding inward of the belt is fixed to an inner peripheral surface of the belt and an end portion in the orthogonal direction orthogonal to the rotation direction of the belt,
The image forming apparatus has a tension portion that abuts on the inner peripheral surface of the belt and a central portion in the orthogonal direction perpendicular to the rotation direction, and stretches the belt rotatably.
The stretching portion regulates movement of the belt in an orthogonal direction orthogonal to the rotation direction by contacting the protruding member fixed to the belt,
The roller is provided at a position facing the protruding member via the belt,
The one end side of the shaft of the roller is a center side of the belt in the orthogonal direction, and the other end side of the shaft of the roller is an end side of the belt in the orthogonal direction;
The bearing is attached to the support member so as to be movable relative to the support member;
The bearing is fitted with the support member on one end side in the longitudinal direction, and a receiving portion for receiving the shaft of the roller is disposed on the other end side in the longitudinal direction with respect to the support member in the axial direction of the roller. A fastening portion fastened to the support member by a fastening member so as to be movable in a crossing direction intersecting with
The receiving part is movable in the crossing direction with respect to the support member;
The fastened portion is fastened to the support member by the fastening member so as to be movable in the axial direction with respect to the support member;
The receiving portion is movable in the axial direction with respect to the support member;
The support member includes one end side bent portion for supporting one end side of the shaft of the roller via the bearing, and another end side bent portion for directly supporting the other end side of the shaft. An image forming apparatus. Computer, and
An image forming apparatus connectable to the computer, wherein the intermediate transfer member is in contact with the intermediate transfer member and a rotatable intermediate transfer member serving as an intermediate medium when the developer image is transferred to the medium. A conductive roller that rotates as the roller rotates, a resin bearing for receiving the shaft of the roller, and one end side of the shaft of the roller is supported via the bearing, and the other end side of the shaft is supported. An image forming apparatus comprising: a conductive support member that directly supports; and a transfer voltage application unit that applies a transfer voltage to the intermediate transfer body via the support member and the roller.
An image forming system comprising:

Images