JP2010128022A - Image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image forming apparatus capable of reducing pressure load applied on an image carrier, thereby stabilizing its operation. <P>SOLUTION: The image forming apparatus 100 includes: an image carrier which is rotatively supported by a rotation shaft fixed to a housing; an electrostatic latent image formation unit which forms an electrostatic latent image on the image carrier; a developing unit which has a developer carrier for conveying developer, while holding the developer on its periphery, and forms a toner image by developing an electrostatic latent image on the image carrier; a transfer unit that transfers a toner image on the image carrier to a transfer body; and a cleaning unit having a cleaning member for removing the toner remaining on the image carrier. The developing unit and cleaning unit are disposed substantially opposite to the image carrier. The developer carrier and cleaning member are connected by a connection member so as to substantially uniformly press the image carrier. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an image forming apparatus.

  An image forming apparatus such as a printer or a copier develops an electrostatic latent image formed on a photoconductor, which is an image carrier, and then transfers the image to a transfer member to fix it, thereby forming a desired image. In general, as shown in FIG. 5, the image forming apparatus 10 includes a photosensitive member 11, a charging roller 12 that charges the photosensitive member 11, an exposure unit 13 that exposes the charged photosensitive member 11, and the photosensitive member 11 by exposure. A developing unit for developing the electrostatic latent image formed thereon, and a transfer unit (not shown) for transferring a toner image generated by developing the electrostatic latent image to a transfer body (not shown). And a cleaning blade 16 for removing the toner remaining on the photoconductor 11 after the toner image is transferred. The developing unit includes two augers 14 a and 14 b that stir the developer, and a developing roller 15 that develops the electrostatic latent image on the photoconductor 11. The image forming apparatus 10 is configured by arranging other units in the circumferential direction of the photoconductor 11.

  Two members of the developing roller 15 of the developing unit and the cleaning blade 16 are in pressure contact with the photoreceptor 11 of the image forming apparatus 10. The pressure contact method of the developing roller 15 and the cleaning blade 16 includes a method using a low load method using a spring and a method using a constant displacement method with a fixed rotation shaft position (for example, Patent Documents 1 to 3). . The pressing force of the developing roller 15 against the photosensitive member 11 varies depending on the amount of developer on the developing roller 15, the usage environment of the image forming apparatus 10, the wear of the contact member, and the like. Similarly, the pressing force of the cleaning blade 16 against the photosensitive member 11 varies due to material change, deformation, wear, or the like of the member.

JP-A-7-146634 JP-A-9-281869 JP 2001-22248 A

  In recent years, as the image forming apparatus 10 becomes smaller and lighter, the contact pressure by the developing roller 15 and the cleaning blade 16 that are in pressure contact with the photoconductor 11 affects the drive of the photoconductor 11 and the rotation axis of the photoconductor 11. Can no longer be ignored. In particular, when the developing roller 15 and the cleaning blade 16 are provided substantially opposite to the photoconductor 11, if one of the pressures is greater than the other, the rotating shaft of the photoconductor 11 may be deformed due to the influence. Cause distortion. For this reason, there is a possibility that the stability of driving is impaired. As a method for increasing the rigidity of the rotating shaft of the photoconductor 11, it is conceivable to increase the shaft diameter of the rotating shaft, but the apparatus is enlarged.

  Further, when the contact force of the developing roller 15 with respect to the photoconductor 11 is too strong, the photoconductor 11 is distorted toward the cleaning blade 16. At this time, the cleaning blade 16 is pressed from the photoconductor 11, and the contact portion with the photoconductor 11 is warped as shown in FIG. 6, which promotes wear and deterioration of the cleaning blade 16. On the contrary, when the contact force of the cleaning blade 16 to the photoconductor 11 is too strong, the variation in the distance between the photoconductor 11 and the developing roller 15 becomes large, which causes a deterioration in image quality.

  Accordingly, the present invention has been made in view of the above problems, and an object of the present invention is to reduce the pressure load applied to the image carrier and to realize the stabilization of the operation. Another object of the present invention is to provide an improved image forming apparatus.

  In order to solve the above-described problems, according to one aspect of the present invention, an image carrier that is rotatably supported by a rotation shaft fixed to a housing, and a static image that forms an electrostatic latent image on the image carrier. An electrostatic latent image forming unit, a developer carrying member that carries and transports a developer on the peripheral surface, a developing unit that develops an electrostatic latent image on the image carrying member to generate a toner image, and an image carrying member An image forming apparatus is provided that includes a transfer unit that transfers a toner image on a body to a transfer body, and a cleaning unit that includes a cleaning member that removes toner remaining on the image carrier. The developing unit and the cleaning unit are provided so as to be substantially opposed to the image carrier. The developer carrier and the cleaning member are connected by a connecting member so as to press the image carrier almost uniformly.

  According to the present invention, the developer carrying member and the cleaning member of the developing unit and the cleaning unit provided so as to be substantially opposed to the image carrying member are connected by the connecting member. At this time, by providing the connecting member so that the developer carrying member and the cleaning member pressurize the image carrying member substantially evenly, it is possible to prevent the pressure from either one on the image carrying member from increasing. . Thereby, the pressure load applied to the image carrier can be reduced.

  Here, an elastic member can be used as the connecting member. As the elastic member, for example, a tension spring that connects the rotating shaft of the developer carrier and the cleaning member and pressurizes the developer carrier to the image carrier side can be used. Alternatively, as the elastic member, for example, a compression spring that connects a support member that movably supports the rotation shaft of the developer carrier and a cleaning member and pressurizes the support member to the image carrier side can be used.

  In addition, a first regulating member that prevents the developer carrier from pressing the image carrier at a predetermined pressure or higher and a second regulating member that prevents the cleaning member from pressing the image carrier at a predetermined pressure or higher. And a regulating member.

  For example, a cleaning blade or a cleaning brush can be used as the cleaning member.

  As described above, according to the present invention, it is possible to provide an image forming apparatus capable of reducing the pressure load applied to the image carrier and realizing stable operation.

  Exemplary embodiments of the present invention will be described below in detail with reference to the accompanying drawings. In addition, in this specification and drawing, about the component which has the substantially same function structure, duplication description is abbreviate | omitted by attaching | subjecting the same code | symbol.

(First embodiment)
First, a schematic configuration of an image forming apparatus 100 according to the first embodiment of the present invention will be described with reference to FIG. FIG. 1 is a schematic explanatory diagram illustrating a schematic configuration of the image forming apparatus 100 according to the present embodiment.

<Configuration of image forming apparatus>
The image forming apparatus 100 according to the present embodiment is a laser printer, a copier, a facsimile, or the like, for example. As an example of the image forming apparatus 100, in FIG. 1, a toner image primarily transferred onto a transfer belt 105 suspended by four rollers 107 a, 107 b, 107 c, and 107 d is secondarily transferred onto a sheet P to form an image. 1 shows an image forming apparatus 100 of an obtained type. The image forming apparatus 100 includes a paper supply unit 110, an image forming unit 120, and a fixing unit (not shown).

  The paper supply unit 110 is a unit that stacks paper P onto which a toner image formed by an image forming unit 120 described later is transferred, and outputs the paper P to the transfer roller 109.

  The image forming unit 120 is a unit that forms a toner image to be transferred onto the paper P. For example, four image forming units 120B, 120C, 120Y, and so on are formed to form toner images of four colors (black, cyan, yellow, magenta). 120M. Each of the image forming units 120B, 120C, 120Y, and 120M includes a photosensitive member 121 on which an electrostatic latent image is formed, a charging roller 122 that charges the peripheral surface of the photosensitive member 121, and a peripheral surface of the charged photosensitive member 121. And an exposure device 123 that forms an electrostatic latent image by exposure. Further, the image forming unit 120 forms a toner image by adhering the toner supplied from the stirrer 124 to the electrostatic latent image formed on the photosensitive member 121 with the stirrer 124 stirring the toner as the developer. And a cleaning blade 126 that removes the toner remaining on the photoreceptor 121 after the toner image is transferred to the paper P. Further, a transfer roller 106 for transferring the toner image onto the paper P is disposed to face the photoconductor 121 with the transfer belt 105 interposed therebetween.

  The image forming apparatus 100 generates a full-color toner image by generating each color toner image by the image forming unit 120 in accordance with the image data, sequentially transferring the toner image onto the transfer belt 105 as an intermediate transfer body, and superimposing them. The full-color toner image is collectively transferred onto the paper P transported from the paper supply unit 110 by the secondary transfer unit constituted by the transfer roller 109 and the roller 107d. The sheet P on which the full color toner image is transferred is conveyed to the fixing unit. In the fixing unit, the full-color toner image is fixed to the paper P by means such as heat or pressure. On the other hand, the transfer belt 105 transfers the full-color toner image to the paper P at the secondary transfer portion, and then is transferred to the cleaner 108 of the cleaning portion, so that the toner remaining on the transfer belt 105 is removed. The roller 107a facing the cleaner 108 functions as a pressure roller that presses the cleaner 108. The roller a presses the cleaner 108 by being pressed toward the cleaner 108 by the pressurizing spring 107e.

  The configuration of the image forming apparatus 100 according to the present embodiment has been described above. The image forming unit 120 of the image forming apparatus 100 according to the present embodiment is configured such that the balance of the pressure applied to the photosensitive member 121 by the developing roller 125 and the cleaning blade 126 is substantially equal. Thereby, dynamic positional problems such as bending of the rotating shaft of the photoconductor 121 are eliminated. Hereinafter, the configuration of the pressure balance adjusting mechanism that adjusts the balance of the pressure applied to the photoreceptor 121 will be described in detail with reference to FIGS. 2 and 3. FIG. 2 is a schematic side view showing the configuration of the image forming unit 120 of the image forming apparatus 100 according to the present embodiment. FIG. 3 is a schematic plan view showing the configuration of the image forming unit 120 of the image forming apparatus 100 according to the present embodiment. 2 and 3, the description of the charging roller 122 and the exposure device 123 constituting the image forming unit 120 is omitted.

<Pressure balance adjustment mechanism in image forming unit>
In the image forming unit 120, as described above, the charging roller 122, the exposure device 123, the developing roller 125, and the cleaning blade 126 are arranged in the circumferential direction of the photosensitive member 121. Among these components, the developing roller 125 and the cleaning blade 126 are provided in contact with the photoconductor 121 and are arranged so as to substantially face the photoconductor 121 as shown in FIG. . For this reason, the photosensitive member 121 receives a pressing force from the developing roller 125 and the cleaning blade 126 and may affect the driving and the rotating shaft 121 of the photosensitive member 121. For example, if the pressure of either the developing roller 125 or the cleaning blade 126 is greater than the pressure of the other, the rotating shaft 121a of the photoreceptor 121 is deformed or distorted to the other side, and the driving stability is impaired. . Therefore, in the image forming unit 120 according to the present embodiment, a pressure balance adjustment mechanism that adjusts the balance of pressure with respect to the photoconductor 121 is provided to solve such a problem.

  As shown in FIG. 2, the image forming unit 120 according to the present embodiment connects the rotation shaft 125 a of the developing roller 125 and the mounting portion 127 a provided on the support member 127 that supports the cleaning blade 126 with an elastic member 128. And a pressure balance adjusting mechanism for the photosensitive member 121. As shown in FIG. 3, the attachment portion 127 a is provided so as to protrude in the axial direction from both side surfaces of the support member 127. Further, as shown in FIG. 2, the attachment portion 127 a is disposed on the cleaning blade 126 side from the rotation fulcrum F of the cleaning blade 126. That is, the attachment portion 127 a rotates and moves in the same direction as the rotation direction of the cleaning blade 126.

  The elastic member 128 that adjusts the pressure balance with respect to the photoconductor 121 according to the present embodiment has an elastic force that pressurizes the developing roller 125 and the cleaning blade 126 toward the photoconductor 121. As the elastic member 128, for example, a tension spring can be used. As shown in FIG. 3, the elastic members 128 are provided on both ends of the photoreceptor 121.

  More specifically, as shown in FIG. 2, the elastic member 128 has one end 128 a attached to the end of the rotating shaft 125 a of the developing roller 125 and the other end 128 b provided on the support member 127 of the cleaning blade 126. It is attached to the attachment portion 127a. Since the elastic member 128 according to the present embodiment has a pulling force, the connected developing roller 125 and cleaning blade 126 are attracted to the photoconductor 121 side by the elastic member 128 with the same pulling force. At this time, due to the elastic member 128, the contact force of the developing roller 125 with respect to the photosensitive member 121 and the contact force of the cleaning blade 126 with respect to the photosensitive member 121 become substantially equal.

  Since the rotating shaft 121a of the photosensitive member 121 is fixed to the housing of the image forming apparatus 100, the position of the photosensitive member 121 is moved by the contact force of the developing roller 125 and the cleaning blade 126 against the photosensitive member 121. There is no.

  The image forming unit 120 having such a pressure balance adjusting mechanism for the photosensitive member 121 uses the elastic member 128 to make the balance of the pressure applied to the photosensitive member 121 by the developing roller 125 and the cleaning blade 126 substantially equal. be able to.

  For example, in the image forming unit 120 according to the present embodiment, it is assumed that the contact force of the developing roller 125 with respect to the photosensitive member 121 is too strong. That is, in FIG. 2, the developing roller 125 strongly presses the photosensitive member 121 toward the photosensitive member 121 side (the right side in FIG. 2). At this time, since the elastic member 128 contracts, the force with which the elastic member 128 pulls the developing roller 125 becomes weak. On the other hand, when the developing roller 125 presses the photoconductor 121, the photoconductor 121 presses the cleaning blade 126. For this reason, the cleaning blade 126 moves in the right direction of FIG. At this time, since the elastic member 128 extends, the force with which the elastic member 128 pulls the cleaning blade 126 is increased. That is, the force with which the developing roller 125 comes into contact with the photoconductor 121 and the force with which the cleaning blade 126 comes into contact with the photoconductor 121 are different.

  In such a state, since the elastic member 128 has a different force for pulling the developing roller 125 and the force for pulling the cleaning blade 126, the elastic member 128 has the developing roller 125 and the cleaning blade 126 so that these tensile forces are balanced. Adjust the position. That is, the developing roller 125 moves in a direction away from the photoconductor 121, and the cleaning blade 126 moves in a direction close to the photoconductor 121. Then, in a state where the tensile force of the elastic member 128 is balanced, the contact force between the developing roller 125 and the cleaning blade 126 with respect to the photosensitive member 121 is substantially equal, and the developing roller 125 is in strong contact with the photosensitive member 121. Is resolved.

  As described above, when the contact force of the developing roller 125 to the photosensitive member 121 is too strong, the photosensitive member 121 can be prevented from being distorted toward the cleaning blade 126 side. Thereby, wear and deterioration of the cleaning blade 126 can be reduced.

  On the other hand, when the contact force of the cleaning blade 126 against the photosensitive member 121 becomes too strong, the cleaning blade 126 strongly pushes the photosensitive member 121 toward the photosensitive member 121 (left side in FIG. 2) in FIG. It will be in the pressed state. At this time, since the elastic member 128 contracts, the force with which the elastic member 128 pulls the cleaning blade 126 is weakened. On the other hand, when the cleaning blade 126 presses the photoconductor 121, the photoconductor 121 presses the developing roller 125. For this reason, the developing roller 125 moves to the left in FIG. At this time, since the elastic member 128 extends, the force with which the elastic member 128 pulls the developing roller 125 becomes stronger. That is, the force with which the developing roller 125 comes into contact with the photoconductor 121 and the force with which the cleaning blade 126 comes into contact with the photoconductor 121 are different.

  In such a state, since the elastic member 128 has a different force for pulling the developing roller 125 and the force for pulling the cleaning blade 126, the elastic member 128 has the developing roller 125 and the cleaning blade 126 so that these tensile forces are balanced. Adjust the position. That is, the developing roller 125 moves in a direction closer to the photoconductor 121, and the cleaning blade 126 moves in a direction away from the photoconductor 121. In a state where the tensile force of the elastic member 128 is balanced, the contact force between the developing roller 125 and the cleaning blade 126 with respect to the photoconductor 121 is substantially equal, and the cleaning blade 126 is in strong contact with the photoconductor 121. Is resolved.

  As described above, even when the contact force of the cleaning blade 126 against the photoconductor 121 is too strong, the photoconductor 121 can be prevented from being distorted toward the developing roller 125. As a result, a change in the distance between the photoconductor 121 and the developing roller 125 can be suppressed, and deterioration in image quality can be prevented.

  The image forming unit 120 according to the present embodiment includes a first restriction that restricts the movement of the developing roller 125 toward the photosensitive member 121 so that the developing roller 125 does not press the photosensitive member 121 with a predetermined pressure or higher. You may make it provide a member. Similarly, a second restricting member that restricts the movement of the cleaning blade 126 toward the photoconductor 121 may be provided so that the cleaning blade 126 does not press the photoconductor 121 above a predetermined pressure. As a result, it is possible to further prevent image quality deterioration due to large distance fluctuations between the photoconductor 121 and the developing roller 125, and wear and deterioration of the cleaning blade 126.

  The image forming apparatus 100 according to the present embodiment has been described above. According to this embodiment, the image forming unit 120 is provided with a pressure balance adjustment mechanism that adjusts the balance of pressure from the developing roller 125 and the cleaning blade 126 to the photosensitive member 121. Thereby, the pressure applied to the photosensitive member 121 from the developing roller 125 and the cleaning blade 126 can be made substantially equal. Therefore, it is possible to prevent any one of the pressures from becoming higher than the other, and to prevent the drive shaft 121a of the photosensitive member 121 from being deformed or distorted. Thereby, stable operation of the image forming unit 120 can be realized.

(Second Embodiment)
Next, an image forming unit 220 according to the second embodiment of the present invention will be described with reference to FIG. The image forming unit 220 according to the present embodiment can be provided in the image forming apparatus 100 as an alternative to the image forming unit 120 according to the first embodiment. The image forming unit 220 according to the present embodiment differs from the image forming unit 120 according to the first embodiment in the arrangement position of the elastic member. Hereinafter, based on FIG. 4, the configuration of the image forming unit 220 according to the present embodiment and the operation of the pressure balance adjusting mechanism will be described. FIG. 4 is a schematic side view showing the configuration of the image forming unit 220 according to the present embodiment. Detailed descriptions of the entire configuration of the image forming apparatus 100 described in the first embodiment and the same configuration as the image forming unit 120 are omitted.

  Similar to the image forming unit 120 of the first embodiment, the image forming unit 220 according to the present embodiment, as shown in FIG. 4, is a photosensitive member 221, a charging roller (not shown), and an exposure device (FIG. A stirrer 224a, 224b, a developing roller 225, and a cleaning blade 226 supported by a support member 227. The image forming unit 220 has a pressure balance adjusting mechanism for the photosensitive member 221 configured by connecting the developing roller 225 and the cleaning blade 226 with an elastic member 228.

  The developing roller 225 according to the present embodiment is provided with a support member 229 that supports the rotary shaft 225a so as to be rotatable around the support shaft 229a. The support member 229 is a plate-like member provided at both ends of the rotation shaft 225a of the developing roller 225 substantially perpendicular to the rotation axis direction. The support member 229 is connected to one end 228 a of the elastic member 228. One end 228a of the elastic member 228 is provided on the opposite side of the rotation shaft 225a of the developing roller 225 with respect to the support shaft 229a. Therefore, when the support member 229 is pressed toward the left side of the sheet of FIG. 4 by the elastic member 228, the developing roller 225 moves in the direction in which the photosensitive member 221 is pressed.

  The cleaning blade 226 is supported by a support member 227, and the support member 227 is connected to the other end 228 b of the elastic member 228. The other end 228 b of the elastic member 228 is provided on the opposite side of the cleaning blade 226 with respect to the fulcrum F. Therefore, when the support member 227 is pressed by the elastic member 228 to the right side in FIG. 4, the cleaning blade 226 moves in a direction in which the photosensitive member 221 is pressed.

  The elastic member 228 for adjusting the pressure balance with respect to the photosensitive member has an elastic force that presses the developing roller 225 and the cleaning blade 226 toward the photosensitive member 221, and for example, a compression spring can be used. The elastic members 228 are provided on both end sides of the photoconductor 221 as in the first embodiment.

  As shown in FIG. 4, the elastic member 228 has one end 228 a attached to the support member 229 that supports the rotating shaft 225 a of the developing roller 225 and the other end 228 b attached to the support member 227 of the cleaning blade 226. Since the elastic member 228 according to the present embodiment has a force to return to the original state with respect to the pressing force from the outside, the support member 229 pressed by the elastic member 228 rotates around the support shaft 229a. The support member 227 rotates and moves around the fulcrum F. Then, the developing roller 225 and the cleaning blade 226 are pressed against the photosensitive member 221 side. At this time, due to the elastic member 228, the contact force of the developing roller 225 with respect to the photosensitive member 221 and the contact force of the cleaning blade 226 with respect to the photosensitive member 221 become substantially equal.

  Since the rotation shaft 221a of the photosensitive member 221 is fixed to the housing of the image forming apparatus 100, the position of the photosensitive member 221 is moved by the contact force of the developing roller 225 and the cleaning blade 226 to the photosensitive member 221. There is no.

  In the image forming unit 220 having such a pressure balance adjusting mechanism for the photosensitive member, the developing roller 225 and the cleaning blade 226 are applied to the photosensitive member 221 using the elastic member 228 as in the first embodiment. The balance of pressure can be made substantially uniform.

  For example, in the image forming unit 220 according to the present embodiment, it is assumed that the contact force of the developing roller 225 with respect to the photosensitive member 221 is too strong. At this time, in FIG. 4, the developing roller 225 strongly presses the photosensitive member 221 toward the photosensitive member 221 side (right side in FIG. 4). At this time, since the elastic member 228 is extended, the force with which the elastic member 228 presses the cleaning blade 226 toward the photosensitive member 221 is reduced. On the other hand, when the developing roller 225 presses the photosensitive member 221, the photosensitive member 221 presses the cleaning blade 226. For this reason, the cleaning blade 226 moves in the right direction in FIG. At this time, since the elastic member 228 contracts, the force with which the elastic member 228 presses the cleaning blade 226 is increased. That is, the force with which the developing roller 225 contacts the photoconductor 221 and the force with which the cleaning blade 226 contacts the photoconductor 221 are different.

  In such a state, since the elastic member 228 has a force that presses the developing roller 225 and a force that presses the cleaning blade 226, the elastic member 228 has the developing roller 225 and the cleaning blade so that these pressing forces are balanced. The position of 226 is adjusted. That is, the developing roller 225 moves in a direction away from the photoconductor 221, and the cleaning blade 226 moves in a direction close to the photoconductor 221. Then, in a state where the pressing force of the elastic member 228 is balanced, the contact force of the developing roller 225 and the cleaning blade 226 with respect to the photosensitive member 221 is substantially equal, and the developing roller 225 strongly contacts the photosensitive member 221. The state is cleared.

  As described above, when the contact force of the developing roller 225 to the photosensitive member 221 is too strong, the photosensitive member 221 can be prevented from being distorted toward the cleaning blade 226 side. Thereby, wear and deterioration of the cleaning blade 226 can be reduced.

  On the other hand, when the contact force of the cleaning blade 226 with respect to the photosensitive member 221 becomes too strong, in FIG. 4, the cleaning blade 226 strongly pushes the photosensitive member 221 toward the photosensitive member 221 (left side in FIG. 4). It will be in the pressed state. In this state, since the elastic member 228 is extended, the force with which the elastic member 228 presses the developing roller 225 against the photosensitive member 221 is reduced. On the other hand, when the cleaning blade 226 presses the photoconductor 221, the photoconductor 221 presses the developing roller 225. For this reason, the developing roller 225 moves to the left in FIG. At this time, since the elastic member 228 contracts, the force with which the elastic member 228 pushes the developing roller 225 becomes stronger. That is, the force with which the cleaning blade 226 abuts on the photoconductor 221 is different from the force with which the developing roller 225 abuts on the photoconductor 221.

  In such a state, since the elastic member 228 has a force that presses the developing roller 225 and a force that presses the cleaning blade 226, the elastic member 228 has the developing roller 225 and the cleaning blade so that these pressing forces are balanced. The position of 226 is adjusted. That is, the developing roller 225 moves in the direction approaching the photoconductor 221, and the cleaning blade 226 moves in a direction away from the photoconductor 221. Then, in a state where the pressing force of the elastic member 228 is balanced, the contact force between the developing roller 225 and the cleaning blade 226 with respect to the photosensitive member 221 becomes substantially equal, and the cleaning blade 226 comes into strong contact with the photosensitive member 221. The state is cleared.

  As described above, even when the contact force of the cleaning blade 226 to the photosensitive member 221 is too strong, the photosensitive member 221 can be prevented from being distorted toward the developing roller 225. As a result, a change in the distance between the photosensitive member 221 and the developing roller 225 can be suppressed, and deterioration of the image quality can be prevented.

  Note that the image forming unit 220 according to the present embodiment is also sensitive to the photosensitivity of the developing roller 225 so that the developing roller 225 does not press the photoconductor 221 with a predetermined pressure or higher, like the image forming unit 120 of the first embodiment. You may make it provide the 1st control member which controls the movement to the body 221 side. Similarly, a second regulating member that regulates the movement of the cleaning blade 226 toward the photosensitive member 221 may be provided so that the cleaning blade 226 does not press the photosensitive member 221 above a predetermined pressure. Accordingly, it is possible to further prevent image quality deterioration due to a large distance fluctuation between the photosensitive member 221 and the developing roller 225, and wear and deterioration of the cleaning blade 226.

  The image forming unit 220 according to the present embodiment has been described above. According to the present embodiment, the image forming unit 220 is provided with a pressure balance adjusting mechanism that adjusts the balance of pressure from the developing roller 225 and the cleaning blade 226 to the photosensitive member 221. Thereby, the pressure applied to the photosensitive member 221 from the developing roller 225 and the cleaning blade 226 can be made substantially equal. Therefore, it is possible to prevent any one of the pressures from becoming larger than the other, and it is possible to prevent the drive shaft 221a of the photosensitive member 221 from being deformed or distorted. Thereby, a stable operation of the image forming unit 220 can be realized.

  The preferred embodiments of the present invention have been described in detail above with reference to the accompanying drawings, but the present invention is not limited to such examples. It is obvious that a person having ordinary knowledge in the technical field to which the present invention pertains can come up with various changes or modifications within the scope of the technical idea described in the claims. Of course, it is understood that these also belong to the technical scope of the present invention.

  For example, in the above embodiment, the cleaning blade is used as a member for removing the residual toner and the like on the photoreceptor, but the present invention is not limited to such an example. For example, a cleaning brush may be used.

1 is a schematic explanatory diagram illustrating a schematic configuration of an image forming apparatus according to a first embodiment of the present invention. FIG. 2 is a schematic side view showing a configuration of an image forming unit of the image forming apparatus according to the embodiment. FIG. 2 is a schematic plan view illustrating a configuration of an image forming unit of the image forming apparatus according to the embodiment. It is a schematic side view which shows the structure of the image forming unit of the image forming apparatus concerning the 2nd Embodiment of this invention. It is a schematic side view showing the configuration of an image forming unit of a conventional image forming apparatus. In the conventional image forming unit, it is explanatory drawing which shows a state when the contact force of a developing roller is too strong.

Explanation of symbols

DESCRIPTION OF SYMBOLS 100 Image forming apparatus 120, 220 Image forming unit 121,221 Photoconductor 125,225 Developing roller 126,226 Cleaning blade 127,227,229 Support member 128,228 Elastic member 229a Support shaft F Support point

Claims (7)

An image carrier that is rotatably supported by a rotation shaft fixed to the housing;
An electrostatic latent image forming unit for forming an electrostatic latent image on the image carrier;
A developing unit that has a developer carrying body for carrying and transporting the developer on the peripheral surface, and that develops an electrostatic latent image on the image carrying body to generate a toner image;
A transfer unit for transferring a toner image on the image carrier to a transfer member;
A cleaning unit having a cleaning member for removing toner remaining on the image carrier;
With
The developing unit and the cleaning unit are provided so as to be substantially opposed to the image carrier,
The image forming apparatus, wherein the developer carrier and the cleaning member are coupled by a coupling member so as to press the image carrier substantially uniformly.   The image forming apparatus according to claim 1, wherein the connecting member is an elastic member.   The image forming apparatus according to claim 2, wherein the elastic member is a tension spring that connects a rotation shaft of the developer carrying member and the cleaning member and pressurizes the rotating member toward the image carrying member.   3. The compression member according to claim 2, wherein the elastic member is a compression spring that connects a support member that movably supports a rotation shaft of the developer carrier and the cleaning member, and pressurizes the support member toward the image carrier. Image forming apparatus. A first regulating member for preventing the developer carrying body from pressing the image carrying body at a predetermined pressure or higher;
A second regulating member for preventing the cleaning member from pressing the image carrier at a predetermined pressure or higher;
An image forming apparatus according to claim 1, comprising:   The image forming apparatus according to claim 1, wherein the cleaning member is a cleaning blade.   The image forming apparatus according to claim 1, wherein the cleaning member is a cleaning brush.

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