JP5067097B2 - Image carrier unit and rotating unit - Google Patents

Description

  The present invention relates to an image carrier unit and a rotator unit.

  An image forming apparatus including a photoconductor includes a charging device that charges the photoconductor and a cleaning device that cleans the charging device. The charging device and the cleaning device are supported in a state where both end portions can rotate, and the cleaning device is pressed against the charging device. The charging device is cleaned by rotating the cleaning device in contact with the charging device. The configuration of such an image forming apparatus is described in Patent Document 1, for example.

JP-A-8-62948

  When the support structure of the charging device and the cleaning device is a structure in which the shaft is passed through the bearing, such as a shaft support structure using a bearing, an operation involving movement in the axial direction is required during assembly. In this case, a large amount of work is required for assembling the bearing portion, which causes a high cost. As a structure that alleviates this problem, there is a structure in which the bearing portion has a concave receiving structure. In this case, the operation of passing the shaft through the bearing can be omitted, and the operation cost can be reduced compared to the above case.

  However, in the concave bearing, the shaft is not supported on the entire circumference, but is supported from one side of the circumference, and therefore the inclination of the bearing is likely to occur. In particular, since the charging device needs to be pressed and held on the photosensitive member by a spring or the like, the structure supported by the concave portion is likely to cause the inclination due to the pressing force. When this inclination occurs, the distance between the axes of the charging device and the cleaning device changes, and the mutual contact state changes. This change causes a reduction in the cleaning capability of the cleaning device. Accordingly, an object of the present invention is to provide a technique capable of reducing the inclination of the shaft caused by the inclination of the bearing portion.

The invention according to claim 1 includes a contacted member, a rotation shaft, and a contact member disposed around the rotation shaft, and rotates around the rotation shaft to contact the contacted member. comprising a roll, a support member having a first support portion for supporting in contact with said rotary shaft, and a pressing means for pressing the support member against the contacted member, the first support portion is the The support member has a contact part that contacts the first roll and a non-contact part that does not contact the first roll in a state where the support member is not inclined in the axial direction of the rotating shaft, and the contact part is The support member is inclined in the axial direction of the rotation shaft by projecting toward the rotation shaft and providing a gap between the end of the rotation shaft and the wall surface of the support member facing the end . wherein the end portion of the front Symbol rotating shaft support member is prevented from contacting when A rotator unit, wherein.

According to a second aspect of the present invention, an image holding body for holding an image, a charging roll rotating shaft, and a charging member disposed around the charging roll rotating shaft, the rotating shaft for the charging roll being the center. A charging roll that rotates to charge the surface of the image carrier, a support member that includes a first support part that contacts and supports the rotary shaft for the charging roll, and presses the support member against the image carrier. And a non-contact portion that does not contact the contact portion that contacts the charging roll in a state where the support member is not inclined in the axial direction of the rotary shaft for the charging roll. The contact portion protrudes toward the charging roll rotation shaft with respect to the non-contact portion, and an end portion of the charging roll rotation shaft and a wall surface of the support member facing the end portion by gap is provided between said support member An image carrier unit, characterized in that the end portion of the support member prior Symbol charging roll rotating shaft is prevented from contacting when inclined in the axial direction of the for charging roll rotation axis.

The invention according to claim 3 is provided with a first roll rotating shaft and a contact surface disposed around the first roll rotating shaft, and rotates around the first roll rotating shaft. A first roll contacting the contacted surface, a cleaning roll rotating shaft, and a cleaning member disposed around the cleaning roll rotating shaft. A support provided with a cleaning roll for cleaning one roll, a first support part that contacts and supports the first rotating shaft for rolls, and a second support part that contacts and supports the rotating shaft for cleaning rolls And a pressing means for pressing the support member against the contacted surface, and the first support portion is in a state where the support member is not inclined in the axial direction of the first rotating shaft for the roll. A contact portion that contacts the first roll and a non-contact portion that does not contact the first roll. The second support portion includes a contact portion that contacts the cleaning roll and a non-contact portion that does not contact the support member in a state where the support member is not inclined in the axial direction of the rotary shaft for the cleaning roll, The contact portion of the first support portion protrudes toward the first rotation shaft for the roll with respect to the non-contact portion of the first support portion, so that the support member is the first rotation shaft for the roll. as an end portion of the support member prior Symbol first roll rotating shaft when tilted in the axial direction are not in contact, the contact portion of the second support portion is a non-contact of the second supporting portion by projecting toward the rotating shaft for the cleaning roll relative to the part, the end of the previous SL rotational axis cleaning roller to said support member when said support member is tilted in the axial direction of the rotating shaft for the cleaning roller So that the contact portion of the first support portion is at the center of the first support portion. And it arrange | positions inside the axial direction of the said 1st roll, The contact part of the said 2nd support part has arrange | positioned the axial direction outer side of the said cleaning roll with respect to the center of the said 2nd support part. The rotating body unit is characterized.

According to a fourth aspect of the present invention, an image holding body for holding an image, a charging roll rotating shaft, and a charging member disposed around the charging roll rotating shaft, the rotating shaft for the charging roll being the center. And a charging roll for charging the surface of the image holding member, a cleaning roll rotating shaft, and a cleaning member disposed around the cleaning roll rotating shaft, and rotating about the cleaning roll rotating shaft. A cleaning roll that cleans the charging roll; a support member that includes a first support portion that contacts and supports the rotating shaft for the charging roll; and a second support portion that contacts and supports the rotating shaft for the cleaning roll; And a pressing unit that presses the support member against the image carrier, and the first support portion is attached to the charging roll in a state where the support member is not inclined in the axial direction of the charging roll rotating shaft. Contact with the contact part A non-contact portion, and the second support portion is not in contact with a contact portion that is in contact with the cleaning roll in a state where the support member is not inclined in the axial direction of the rotary shaft for the cleaning roll. A contact portion of the first support portion protrudes toward the rotary shaft for the charging roll with respect to the non-contact portion of the first support portion, so that the support member becomes the charging roll. wherein the support member is an end portion of the front Symbol rotation axis charging roller so as not to contact when inclined in the axial direction of use the rotation axis, the contact portion of the second supporting portion is the second supporting portion non of by projecting toward the rotating shaft for the cleaning roll relative to the contact portion, said support member of said support member prior Symbol rotation axis cleaning roller when inclined in the axial direction of the rotating shaft for the cleaning roller The end portion is prevented from contacting, and the contact portion of the first support portion is the first support portion. The contact portion of the second support portion is disposed outside the cleaning roll in the axial direction with respect to the center of the second support portion. An image carrier unit characterized by the above.

  According to invention of Claim 1, the inclination of the axis | shaft resulting from the inclination of a bearing part can be reduced.

  According to the second aspect of the present invention, the influence of the inclination of the bearing portion of the charging roll on the inclination of the axis of the charging roll can be reduced.

  According to invention of Claim 3, the fluctuation | variation which arises in the distance between a 1st roll and the cleaning roll which contacts a 1st roll by the inclination of the bearing part which supports a 1st roll and a cleaning roll. Can be reduced.

  According to invention of Claim 4, the fluctuation | variation which arises in the distance between a charging roll and a cleaning roll by the inclination of the bearing part which supports a charging roll and a cleaning roll can be reduced.

(1) First embodiment (configuration of the embodiment)
FIG. 1 is a conceptual diagram showing a configuration of an image forming apparatus using the invention. FIG. 1 shows a color printer 100 which is an example of an image forming apparatus. The color printer 100 includes a one-drum type rotary developing device 101. The rotary developing device 101 can be rotated by a driving mechanism (not shown) and includes four developing devices corresponding to basic colors of YMCK (Yellow, Magenta, Cyan, black).

  In this example, as a developing unit, a Y developing unit 11 that develops a yellow basic color image, an M developing unit 12 that develops a basic color image of Magenta, a C developing unit 13 that develops a basic color image of Cyan, and a basic unit of black A K developing device 14 for developing a color image is prepared. Each developing device basically has the same structure. For example, the Y developing device 11 includes a toner bottle 11a and a toner supply mechanism 11b. Each of the four toner bottles stores one of YMCK toners corresponding to the developing devices 11 to 14. Each toner supply mechanism includes a drum-like member (for example, indicated by reference numeral 11 c) for supplying toner to the photosensitive drum 103. By rotating the drum-shaped member, toner is supplied to the photosensitive drum 103. Further, the rotary developing device 101 includes a developing bias potential applying unit (not shown) that applies a DC voltage as a developing bias between each toner supply mechanism and the photosensitive drum 103. A photosensitive drum 103 that can be rotated by a driving mechanism (not shown) is disposed in contact with the rotary developing device 101, and a charging roll 40 is disposed in contact with the photosensitive drum 103.

  As shown in FIG. 3, the charging roll 40 is a rotating body having a function of charging the photosensitive drum 103. In this example, the charging roll 40 includes a cylindrical or columnar charging member 400. The surface of the charging member 400 is made of a conductive material. A voltage obtained by superimposing an AC voltage on a DC voltage is applied to the charging member 400 from a high voltage power source described later, and an electric field is applied to the photosensitive drum 103 to charge the surface of the photosensitive drum 103. The charge amount for the photosensitive drum 103 is controlled by controlling the value of the DC voltage.

  The charging member 400 has a structure in which a charging roll rotation shaft 401 is fixed in a penetrating manner, and the charging member 400 is disposed around the charging roll rotation shaft 401. The length of the charging roll rotating shaft 401 (length in the X-axis direction in the figure) is longer than that of the charging member 400, and both ends thereof protrude from both ends of the charging member 400. This protruding portion is described as a charging roll rotating shaft 401 (401a and 402b). As will be described later, the charging roll rotating shaft 401 (401a and 402b) is supported by a support member, and the charging roll 40 is supported in a rotatable state.

  Returning to FIG. 1, the cleaning roll 30 is disposed in a state of contacting the charging roll 40 on the side opposite to the side of the charging roll 40 that contacts the photosensitive drum 103. The cleaning roll 30 has a function of cleaning the surface by contacting the charging roll 40. As shown in FIG. 3, the cleaning roll 30 includes a cleaning member 300 having a cylindrical shape or a columnar shape including a porous resin (urethane in this example) layer on the surface. In a state where the porous resin layer is relatively pressed and brought into contact with the charging member 400 of the charging roll 40, the charging roll 40 and the cleaning roll 30 are rotated in opposite directions, so that the surface of the charging member 400 is Cleaning of adhering dust and residual toner is performed by the cleaning member 300. A cleaning roll rotating shaft 301 is penetrated and fixed to the cleaning roll 30, and a cleaning member 300 is arranged around the cleaning roll rotating shaft 301. The length of the cleaning roll rotating shaft 301 (length in the X-axis direction in the drawing) is longer than that of the cleaning member 300, and both ends thereof protrude from both ends of the cleaning member 300. The protruding portion is shown as a cleaning roll rotating shaft 301 (301a and 302b). As will be described later, the cleaning roll rotating shaft 301 (301a and 302b) is supported by the support member, and the cleaning roll 30 is supported in a rotatable state. The details of the structure that supports the charging roll 40 and the cleaning roll 30 in a rotatable state will be described later.

  Returning to FIG. 1, the static eliminator 111 is disposed in the vicinity of the photosensitive drum 103. The static elimination 111 removes the electric charge charged on the photosensitive drum 103 so that the subsequent charging by the charging roll 40 is performed uniformly and at a predetermined charge density.

  The photosensitive drum 103 is partially exposed to scanning light emitted from a ROS (raster optical scanner) 113, and a latent image is formed on the surface thereof. The ROS 113 is a writing exposure scanning device, and includes a laser irradiation device 113a and an optical system 113b for guiding laser light. According to this configuration, the photosensitive drum 103 charged by the charging roll 40 rotates counterclockwise in FIG. 1, and at that time, the scanning light corresponding to the exposure pattern is irradiated from the ROS 113 to the photosensitive drum 103. Is done. As a result, a latent image (electrostatic latent image) constituted by a difference in surface potential is formed on the surface of the photosensitive drum 103.

  At this time, the toner supply mechanism (for example, reference numeral 11 c) of a predetermined developing device disposed in the rotary developing device 101 is controlled to a position facing the photosensitive drum 103. Then, any toner of YMCK is supplied onto the photosensitive drum 103, and the toner adheres to the surface of the photosensitive drum 103 according to the latent image. As a result, any toner image of YMCK is formed on the photosensitive drum 103. In this way, the latent image formed on the photosensitive drum 103 is developed.

  A cleaning blade 118 as a cleaning unit is disposed in the vicinity of the photosensitive drum 103. The cleaning blade 118 comes into contact with the surface of the photosensitive drum 103 and scrapes off the remaining toner. The toner scraped off is collected by a toner collecting unit (not shown). Further, contact / separation means (not shown) for driving the cleaning blade 118 to freely contact or separate the photosensitive drum 103 is disposed.

  An intermediate transfer member 114 is disposed in contact with the photosensitive drum 103. The intermediate transfer member 114 has a closed belt shape. Further, a primary transfer roll 115 is disposed at a position facing the photosensitive drum 103 with the intermediate transfer member 114 interposed therebetween. A bias voltage for creating a transfer electric field necessary for transferring the toner image can be applied between the photosensitive drum 103 and the primary transfer roll 115. The intermediate transfer member 114 is rotated by the driving roll 116 at a speed synchronized with the rotation of the photosensitive drum 103. At this time, the intermediate transfer body 114 is sandwiched between the photosensitive drum 103 and the primary transfer roll 115, and at that time, a bias voltage is applied between the photosensitive drum 103 and the primary transfer roll 115. The toner image is transferred from the photosensitive drum 103 to the intermediate transfer member 114 (primary transfer). For example, if the image to be formed is a color image composed of each color of YMCK, primary transfer for each color of YMCK is performed four times so that the four color images are superimposed, and a color toner image is formed on the intermediate transfer member 114. Formed.

  A charging roll 117 is disposed in the vicinity of the intermediate transfer member 114. The charging roll 117 applies a DC voltage to the intermediate transfer member 114 to positively charge the toner remaining on the intermediate transfer member 114 after the secondary transfer. The positively charged toner adheres to the photosensitive drum 103 and is recovered by the action of an electric field of DC voltage applied between the photosensitive drum 103 and the primary transfer roll 115. The toner collected on the photosensitive drum 103 is removed by the cleaning blade 118 and collected by a toner collecting unit (not shown).

  A paper storage device 123 that stores printing paper 122 is stored at the bottom of the color printer 100. The printing paper 122 is transported along the paper transport path 125 by a paper transport system typically indicated by reference numeral 124. Secondary transfer rolls 126 a and 126 b are arranged in the middle of the paper transport path 125. Between the secondary transfer rolls 126a and 126b, a printing sheet (not shown) that has been transported through the paper transport path 125 and the intermediate transfer body 114 are sandwiched, whereby primary transfer is performed on the surface of the intermediate transfer body 114. The toner image is further secondarily transferred to the printing paper. Reference numeral 131 denotes a cleaning roll for cleaning the secondary transfer roll 126b.

  The printing paper on which the toner image has been transferred moves along the paper conveyance path 125 and is conveyed between the fixing rolls 127a and 127b. The fixing roll 127b has a built-in heater, and heats the toner material constituting the toner image on the printing paper at the time of the conveyance. By this heating, the toner is fixed, and an image is formed on the printing paper (that is, printing is performed). The printing paper on which printing has been performed is discharged from the discharge mechanism 128 onto the discharge surface 129. Reference numeral 130 denotes a paper conveyance path when double-sided printing is performed.

  FIG. 2 is a block diagram showing the configuration of the control system of the color printer 100 shown in FIG. The control means 200 includes a CPU, ROM, RAM, and various interface circuits that are not shown. The CPU supervises execution of operations described later in accordance with operation programs stored in the ROM. The ROM stores the above-described operation program and other various setting conditions and data necessary for control. The RAM is used as a working area for temporarily storing various data during operation. Various interfaces have a function of exchanging signals with an apparatus controlled by the control unit 200.

  Hereinafter, an apparatus controlled by the control unit 200 will be described. The photosensitive drum driving unit 201 includes a motor for rotating the photosensitive drum 103 in FIG. 1 and a control circuit for the motor. The intermediate transfer member driving unit 202 is for controlling the cyclic movement of the intermediate transfer member 114 in FIG. 1 and includes a motor for driving the drive roll 116 and its control circuit. The charging roll 40 has the function described with reference to FIG. 1, and the voltage applied to the photosensitive drum 103 is controlled by the control unit 200, whereby the charge amount of the photosensitive drum 103 is adjusted. The cleaning blade contacting / separating means 203 is a driving means for performing contact and contact state of the cleaning blade 118 of FIG. 1 with the photosensitive drum 103 and separation of the cleaning blade 118 from the photosensitive drum 103. The high-voltage power supply 204 is a power supply that generates AC and DC voltages supplied to the charging roll 40, other bias voltages, and the like.

  The ROS 113 is controlled by the control unit 200 and irradiates the photosensitive drum 103 with scanning light to perform optical drawing. The transfer bias control device 206 controls a bias voltage applied between the photosensitive drum 103 and the primary transfer roll 115. The Y developing unit 11, the M developing unit 12, the C developing unit 13, and the K developing unit 14 are controlled by the control unit 200 in terms of the toner supply mechanism and the developing bias potential applying unit. The developing device driving means 207 includes a motor for rotating the rotary developing device 101 and its control circuit.

  The image processing apparatus 209 receives color image data (color image (RGB) print data sent to the color printer 100) sent from a terminal or the like, and converts it into image data of each basic color of YMCK. To do. The image processing apparatus 209 performs processing on image data such as image processing for adjusting gradation and image processing for determining resolution. The image data processed by the image processing device 209 can be stored in the image storage device 210. The image storage device 210 is constituted by a hard disk device. In addition, the color printer 100 includes an operation unit 211. By operating the operation unit 211 by the user, various operations and various conditions are set.

(Outline of support structure for charging roll and electrostatic roll)
Hereinafter, details of a structure for supporting the charging roll 40 and the cleaning roll 30 in a rotatable state will be described. FIG. 3 is a conceptual diagram showing a support structure for the charging roll 40 and the cleaning roll 30. FIG. 4 is a perspective view showing an outline of the support member 500. FIG. 3 conceptually shows the charging unit 140. The charging unit 140 has a structure in which various members are attached to the housing 141. The charging roll 40 and the cleaning roll 30 are attached to the housing 141 via the support member 500 in a rotatable state. The casing 141 is fixed to a structure (not shown) in the image forming apparatus 100 in FIG. 1, so that the charging roll 40 comes into contact with the photosensitive drum 103.

  The support member 500 includes recesses 501 and 511. The recess 501 is opened in the axial direction of the rotating shaft 301a and in a direction different from the axial direction, and supports the rotating shaft 301a inserted from this different direction in a rotatable state. The recess 501 is provided with gaps 503a and 504a for securing a distance between the inner surface of the recess 501 and the outer periphery of the rotation shaft 301a. The concave portion 511 is opened in the axial direction of the charging roll rotating shaft 401a and in a direction different from the axial direction, and supports the charging roll rotating shaft 401a inserted from the different direction in a rotatable state. The recess 511 is provided with a gap 514 for securing a distance between the inner surface of the recess 511 and the outer periphery of the charging roll rotating shaft 401a.

  Note that the rotation shafts 103a and 103b of the photosensitive drum 103 are driven by a driving mechanism (not shown), whereby the photosensitive drum 103 rotates. Since the structure of this drive mechanism and the structure for supporting the rotary shafts 103a and 103b to the color printer 100 are the same as those used in the prior art, detailed description thereof is omitted.

  The support member 500 is pressed against the casing 141 by a coil spring 517 that is a pressure generating unit from the lower side in FIG. For this reason, the support member 500 is attached to the housing 141 while being pressed in the Y direction in the figure by the coil spring 517, whereby the charging roll 40 is pressed against the photosensitive drum 103. The support member 600 is also attached to the housing 141 with the same structure, and pressure in the Y-axis direction is applied from below in FIG. 3 by a coil spring 617 serving as pressure generating means.

  The supporting members 500 and 600 are pushed in the Y-axis direction in the figure by the pressure applied by the coil springs 517 and 617, thereby pushing the cleaning roll 30 and the charging roll 40 in the Y-axis direction. As a result, the charging roll 40 is exposed to light. The cleaning roll 30 is pressed against the charging drum 40 by being pressed against the body drum 103. In this way, the cleaning roll 30 and the charging roll 40 are brought into a state in which pressures pressed against each other are exerted. At this time, the two come into contact with the cleaning roll 30 whose surface is made of a porous resin in a state where the charging roll 40 has bitten into a dimension of, for example, several mm. In addition, the cleaning roll rotating shaft 301 and the charging roll rotating shaft 401 are held inside so as not to be detached from the concave portion serving as a bearing by the pressure applied by the coil springs 517 and 617.

  The support member 500 is attached to the housing 141 in a state in which the support member 500 can move in the Y-axis direction (up and down direction in FIG. 3). That is, as shown in FIG. 4, a groove 516 is formed on the side surface of the support member 500, and the casing 141 includes a long convex portion (not shown) that meshes with the groove 516. Although not shown, this mechanism is the same on the side surface opposite to the side surface on which the groove 516 is formed.

(Cleaning roll support structure)
Support members 500 and 600 are attached to the housing 141. Both ends of the cleaning roller rotating shaft 301 of the cleaning roller 30 are supported by the support members 500 and 600 in a rotatable state. That is, the cleaning roll 30 includes a rotating shaft 301 having one end denoted by reference numeral 301a and the other end denoted by reference numeral 301b. The cleaning roll rotary shafts 301a and 301b are made of resin or metal material. The cleaning roll rotating shaft 301a is supported by the support member 500 in a rotatable state, and the cleaning roll rotating shaft 301b is supported by the support member 600 in a rotatable state.

  Hereinafter, the structure for supporting the cleaning roller rotating shaft 301a in the support member 500 will be described in detail. The support member 500 is made of resin and includes a recess 501. The recess 501 is opened in the negative direction of the X axis and the positive direction of the Y axis, accommodates the rotary shaft 301a inserted from the direction opened in the Y axis direction, and can rotate the rotary shaft 301a therein. Support in good condition. The recess 501 has a cross-sectional shape with a bottom that is semicircular when viewed from the X-axis direction. Further, a convex portion 502 that is a contact portion with the cleaning roll 30 is provided on the inner surface of the concave portion 501.

  The convex part 502 is extended along the circumferential direction of the outer periphery of the rotating shaft 301a (see FIG. 3) to be supported, and the cross section perpendicular to the extending direction has a trapezoidal shape. The top of the convex portion 502 extends in a semicircular shape with a curvature along the outer periphery of the cleaning roller rotating shaft 301a. As shown in FIG. 3, the cleaning roll rotary shaft 301 a is placed on the belt-like surface at the top, and the cleaning roll rotary shaft 301 a is supported in a rotatable state. That is, a half portion in the circumferential direction of the rotating shaft 301 a comes into contact with the convex portion 502 in a slidable state, so that the rotating shaft 301 a is supported by the support member 500 in a rotatable state. In addition, the top part of the convex part 502 is coat | covered with the resin material (for example, fluororesin) with favorable sliding property, etc., and the rotation of the rotating shaft 301a for cleaning rolls is made smooth.

  As shown in FIG. 4, both sides of the convex portion 502 (parts adjacent to the cleaning roll rotating shaft 301a direction: front and rear in the X-axis direction) are one step lower so as not to contact the cleaning roll rotating shaft 301a. The lower surface portions 503 and 504 are formed. By providing the low surface portion 503, a gap 503a and a gap 504a are formed between the support member 500 and the outer periphery of the rotary shaft 301a in the shaft support structure shown in FIG. The gaps 503a and 504a are provided in order to secure a distance between the bottom surface of the recess 501 and the outer periphery of the cleaning roll rotary shaft 301a in the axial direction of the cleaning roll rotary shaft 301a. The convex portion 502, the low surface portion 503, and the low surface portion 504 constitute a support portion. The convex portion 502 is located on the outer side (the end portion side of the cleaning roll rotating shaft 301) than the center in the axial direction of the support portion (the extending direction of the cleaning roll rotating shaft 301). Further, in the shaft support structure shown in FIG. 3, there is a gap 505 between the end 301b of the cleaning roll rotating shaft 301a and the wall surface 500a of the recess 501 (the wall surface facing the end 301b) (see also FIG. 4). Is formed.

  The above is the details of the configuration related to the support of the cleaning roller rotating shaft 301a by the support member 500. This configuration is the same for supporting the cleaning roller rotating shaft 301b by the support member 600. That is, in FIG. 3, the support member 600 is the same as the support member 500, and the left and right directions are reversed, and the support member 600 includes a recess 601 corresponding to the recess 501. Further, a gap 605 corresponding to the gap 505 is formed at the end of the cleaning roll rotating shaft 310b. The cleaning roll rotary shafts 301a and 301b may be separated and not connected.

(Charging roll support structure)
Next, a support structure for the charging roll 40 will be described. Here, the support structure of the charging roll 40 will be described mainly using the support member 500 shown in FIGS. 3 and 4 as an example. The charging roll 40 includes a charging roll rotating shaft 401 protruding at both ends thereof. The charging roll rotating shaft 401 is made of a conductive material (for example, metal) necessary for charging. In FIG. 3, one end side of the charging roll rotating shaft 401 is indicated by reference numeral 401a, and the other end side is indicated by reference numeral 401b.

  The support member 500 includes a recess 511. The concave portion 511 is opened in the negative direction of the X axis and the positive direction of the Y axis, and accommodates therein the charging roll rotating shaft 401a inserted from the opened direction of the Y axis direction, and the charging roll rotating shaft 401a. Is supported in a rotatable state inside. The recess 511 has a cross-sectional shape with a semicircular bottom as viewed from the X-axis direction, and a protrusion 512 is provided on the inner surface thereof.

  The convex portion 512 is a contact portion to the charging roll 40, and extends along the circumferential direction of the outer periphery of the rotating shaft 401 a (see FIG. 3) to be supported, and is a cross section perpendicular to the extending direction. Has a trapezoidal shape. The top of the projection 512 extends into a semicircular shape having a curvature along the outer periphery of the charging roll rotating shaft 401a. The charging roll rotating shaft 401a is placed on and supported by the semicircular top belt-like surface. In other words, a half portion in the circumferential direction of the charging roll rotating shaft 401 a comes into contact with the convex portion 512 in a slidable state, and thereby the charging roll rotating shaft 401 a is supported by the support member 500 in a rotatable state. Is done. In addition, the top part of the convex part 512 is coat | covered with the resin material (for example, fluororesin) with favorable sliding property, etc., and the rotation of the rotating shaft 401a for charging rolls is made smooth.

  As shown in FIG. 4, the convex portion 512 is formed at the end (edge) portion of the concave portion 511 and adjacent to the side surface side (the end portion direction side of the charging roll rotating shaft 401 a), A low surface portion 513 whose surface is lowered by one step is provided so as not to contact the shaft 401a. By providing the low surface portion 513, a gap 514 is formed between the support member 500 and the outer periphery of the charging roll rotating shaft 401a in the shaft support structure shown in FIG. The gap 514 is provided in order to ensure a distance between the bottom surface of the recess 511 and the outer periphery of the charging roll rotating shaft 401a in the axial direction of the charging roll rotating shaft 401a. Further, the convex portion 512 and the low surface portion 513 constitute a support portion. The convex portion 512 is located on the inner side (center side of the charging roll 40) with respect to the axial direction of the support portion (the extending direction of the charging roll rotating shaft 401). In the shaft support structure shown in FIG. 3, there is a gap 515 between the end portion 401c of the charging roll rotating shaft 401a and the wall surface of the recess 511 (the wall surface facing the end portion 401b) 500b (see also FIG. 4). Is formed.

  In addition, the position of the recess 511 is located on the outer side (end side) in the axial direction than the position of the recess 501. That is, when viewed from the direction in which the rotation shaft 301a and the charging roll rotation shaft 401a overlap (the Y-axis direction), the recess 511 is in the axial direction of the charging roll rotation shaft 401a (or the rotation shaft 301a) with respect to the recess 501. Thinking is located outside.

  The above is the details of the configuration relating to the support of the charging roll rotating shaft 401a by the support member 500. This configuration is the same for the support of the charging roll rotating shaft 401b by the support member 600. That is, the support member 600 includes a recess 611 corresponding to the recess 511 of the support member 500, and the charging roll rotating shaft 401b is supported in a rotatable state by the same configuration as described above. . A gap 615 corresponding to the gap 515 is formed at the end of the charging roll rotating shaft 401b. The charging roll rotating shafts 401a and 401b may be separated and not connected. Further, there is a mechanism for supplying a voltage to the charging roll 40 via the charging roll rotating shaft 401, but this mechanism is the same as a mechanism that is normally used, and thus the description thereof is omitted.

(Assembly of charging unit 140)
Hereinafter, an example of an operation procedure for assembling the charging unit 140 shown in FIG. 3 will be described. First, coil springs 517 and 617 are attached to the casing 141. Next, the supporting members 500 and 600 are pushed in from the Y direction in the figure. At this time, a guide in the pushing direction is performed by the function of the groove 516 illustrated in FIG.

  Next, the cleaning roll 30 is pushed into the housing 141 from the Y direction in the figure, and one of the rotation shafts 301a is accommodated in the recess 501 of the support member 500, and the other rotation shaft 301b is accommodated in the recess 601 of the support member 600. . At this time, since the margin of the dimension in which the gap 505 and the gap 605 are formed is set, an error in component accuracy and an error in assembly accuracy in the axial direction are allowed. Depending on the assembled state, the gap 505 or the gap 605 may not be present, or one gap may have a larger gap dimension than the other gap.

  Next, the charging roll 40 is pushed into the housing 141 from the Y direction in the figure, one charging roll rotating shaft 401a is accommodated in the recess 511 of the supporting member 500, and the other charging roll rotating shaft 401b is supported by the supporting member. It is accommodated in 600 recesses 611. At this time, since the margin of the dimension in which the gap 515 and the gap 615 are formed is set, an error in component accuracy and an error in assembly accuracy in the axial direction are allowed. Depending on the assembled state, the gap 515 or the gap 615 may not be present, or one gap may have a larger gap dimension than the other gap. By assembling the charging roll 40 in this way, the charging roll 40 comes into contact with the cleaning roll 30. In this way, the charging unit 140 is obtained.

  Next, the charging unit 140 is attached to the image forming apparatus 100 (see FIG. 1) to which the photosensitive drum 103 is attached by a mechanism not shown. At this time, the charging unit 140 is fixed in the image forming apparatus 100 to obtain the state shown in FIG. In this state, the support members 500 and 600 are pressed in the Y-axis direction in the drawing by the action of the coil springs 517 and 617, and thereby the charging roll 40 is pressed against and contacts the photosensitive drum 103. Further, the cleaning roll 30 is pressed against the charging roll 40 by the pressure. Further, due to the pressure from the coil springs 517 and 617, the charging roll rotating shaft 401 a is pressed and held in the recess 511, and the charging roll rotating shaft 401 b is pressed and held in the recess 611. The charging roll rotating shaft 301a is pressed and held in the recess 501 and the rotating shaft 301b is pressed and held in the recess 601.

  In this state, the cleaning roll 30 and the charging roll 40 are attached to the housing 141 in a state in which a pressure that is pressed relatively to each other is applied. For this reason, both of them come into contact with the cleaning roll 30 whose surface is made of a porous resin with the charging roll 40 biting into a dimension of, for example, several mm.

(Operation of the embodiment)
An example of the operation of the image forming apparatus shown in FIGS. 1 to 3 will be described. When printing is started, image data sent from a terminal (for example, a personal computer) or the like is taken into the image processing apparatus 209. The image data captured by the image processing apparatus 209 is color-separated into YMCK basic color image data, and each color-separated image is stored in a buffer memory (not shown). When the color-separated image is obtained, a transfer bias voltage is applied between the photosensitive drum 103 and the primary transfer roll 115. Further, a condition is set for the toner supply mechanism 11 b of the Y developing device 11 to face the photosensitive drum 103. In addition, the cleaning blade 118 comes into contact with the photosensitive drum 103 so that the toner attached to the surface of the photosensitive drum 103 can be scraped off.

  Next, a toner image forming process is performed. In this example, first, a Y-color toner image is formed. The toner image forming step includes the formation of the toner image on the photosensitive drum 103 and the primary transfer of the toner image to the intermediate transfer member. The toner image is formed on the photosensitive drum 103 as follows. First, in a state where the toner supply mechanism 11b of the Y developing device 11 is opposed to the photosensitive drum 103, the photosensitive drum 103 is rotated in the counterclockwise direction in FIG. As the photosensitive drum 103 rotates, the toner remaining on the surface of the photosensitive drum 103 is scraped off by the cleaning blade 118, and then that portion is neutralized by the static eliminator 111.

  This neutralized portion of the photosensitive drum 103 is charged by the charging roll 40, and further, drawing with a laser beam is performed on the photosensitive drum 103 by the ROS 113. At this time, the portion irradiated with the laser light is exposed to light, and the state of the charge distribution changes. In this way, a latent image (Y-color image latent image) constituted by the distribution of the charged state is formed on the surface of the photosensitive drum 103.

  The portion where the latent image is formed passes through a position facing the toner supply mechanism 11 b of the Y developing device 11 as the photosensitive drum 103 rotates. At this time, Y toner is supplied from the toner supply mechanism 11 b to the photosensitive drum 103, the toner is captured according to the latent image, and a toner image is formed on the photosensitive drum 103.

  This toner image is primarily transferred to the intermediate transfer member 114 between the photosensitive drum 103 and the primary transfer roll 115. The toner remaining on the surface of the photosensitive drum 103 after the transfer is scraped off by the cleaning blade 118. By repeating the above-described cycle, a toner image is continuously formed on the surface of the rotating photosensitive drum 103 and transferred to the intermediate transfer member 114. Then, by rotating the photosensitive drum 103 a predetermined number of times, a toner image of a predetermined basic color (Y in this case) is formed on the intermediate transfer body 114.

  By repeating the above processing, the YMCK toner images are superimposed on the intermediate transfer member 114, and a color toner image is formed on the intermediate transfer member 114. The color toner image is secondarily transferred to the printing paper. At this time, the printing paper 122 is conveyed from the paper storage device 123 along the paper conveyance path 125 to the locations of the secondary transfer rolls 126a and 126b. Then, secondary transfer of the toner image from the intermediate transfer body 114 is performed on the printing paper by the action of the secondary transfer rolls 126a and 126b, and toner is fixed using the fixing rolls 127a and 127b. In this way, a color image is printed on the printing paper. The toner remaining on the surface of the intermediate transfer member 114 after the secondary transfer is positively charged by the action of the charging roll 117 and collected on the photosensitive drum 103.

  In the above processing, the charging roll 40 pressed against the photosensitive drum 103 is rotated by the rotational force of the photosensitive drum 103. Further, as the charging roll 40 rotates, the cleaning roll 30 in contact therewith also rotates. When the charging roll 40 rotates in contact with the photosensitive drum 103, toner or dust remaining on the surface of the photosensitive drum 103 adheres to the surface of the charging roll 40. These deposits are removed by the cleaning roll 30 that is pressed against the charging roll 40 and rotates.

(Evaluation)
In the above operation, the pressure is applied from the cleaning roll 30 to the charging roll 40, and the pressure is applied from the charging roll 40 to the photosensitive drum 103. The support members 500 and 600 are configured to be less inclined with respect to an axis (Z axis in FIG. 4) perpendicular to the XY plane in FIG. 3 by the function of the groove 516 and the like illustrated in FIG. Yes. However, in some cases, the cleaning roller 30 and the charging roller 40 may be inclined in the axial direction due to the application of the pressure described above, problems of dimensional accuracy of the member, wear and deformation of the member, and the like. Here, the support member 500 is inclined in the axial direction of the rotation axis of the cleaning roll 30 and the charging roll 40 because the Z axis is the rotation axis in the XY plane from the state shown in FIG. As described above, the rotation of the support member 500 occurs. In addition, the position of the axis of rotation of this support member may be inside the support member 500 or may be outside. Further, the direction of rotation may be clockwise or counterclockwise. In addition, the fact that the support member 600 is tilted is used in the same meaning.

  FIG. 5 is a conceptual diagram illustrating a state in which the above-described support member is tilted. FIG. 5A shows a case where the support member 500 rotates and tilts counterclockwise, and FIG. 5B shows a case where the support member 500 rotates and tilts clockwise.

  Even if the support member 500 is tilted as shown in FIG. 5A, since the gap 514 is provided, to the support member 500 (the bottom of the recess 511) of the end portion 401d of the charging roll rotating shaft 401a. Can be avoided. For this reason, the lifting of the end edge portion 401d of the charging roll rotating shaft 401a is suppressed until the inclination of the support member 500 proceeds to some extent.

  When the gap 514 is not provided, the edge 401 d of the end edge of the charging roll rotating shaft 401 a comes into contact with the support member 500 and is lifted by the support member 500 with the occurrence of the inclination shown in FIG. As a result, the charging roll rotating shaft 401 is inclined. By providing the gap 514, the lifting of the end portion edge portion 401d of the charging roll rotation shaft 401a due to the inclination of the support member 500 is suppressed, and therefore the inclination of the charging roll rotation shaft 401 is also suppressed.

That is, as shown in FIG. 5 (A), when a clearance 514, even when the inclination of the support member 500 shown by the angle theta _1, dimension of the gap 514 alone, the end of the support member 500 and the shaft Contact with the edge portion 401d can be avoided. Therefore, it is possible to suppress lifting of the portion 401d of the end edges of the shaft with increasing angle theta _1. In other words, even if the support member 500 tilts with respect to the charging roll rotating shaft 401a with the top of the convex portion 512 as a fulcrum, the charging roll rotating shaft 401a escapes into the space of the gap 514. It is possible to avoid contact with the end edge portion 401b.

A similar effect can be pointed out at the end edge portion of the rotating shaft 301a. That is, by gaps 503a are provided, even when the inclination of the supporting member 500 shown in FIG. 5 (A), a situation where the end edge portion of the rotary shaft 301a is in contact with the support member 500 is avoided. Thereby, the lifting of the end of the rotating shaft 301a is suppressed, and the occurrence of fluctuations in the inter-axis distance between the cleaning roll 30 and the charging member 40 is suppressed.

In this way, fluctuations in the inter-axis distance between the charging member 400 and the cleaning member 300 when the support member 500 is tilted with an increase in the angle θ ₁ can be suppressed. That is, it is possible to suppress variation in cleaning function of the cleaning member 300 to the charging member 400 with increasing the angle theta _1.

  FIG. 5B is a conceptual diagram showing a case where the support member 500 is tilted in the opposite direction to the case of FIG. In this case, since the rotating shaft 301a escapes into the gap 504a, a situation where the rotating shaft 301a is lifted by the support member 500 can be avoided. Thereby, generation | occurrence | production of the fluctuation | variation of the center distance can be suppressed.

  FIG. 6 is a conceptual diagram showing the influence of the inclination of the support member. In FIG. 6, support portions 612 and 613 that support the charging roll 40 are shown, and support portions 621 and 622 that support the cleaning roll 30 are also shown. The support part 612 includes a contact part 631 (corresponding to a convex part 512 in FIG. 3), and the support part 613 includes a contact part 632. In addition, the support portion 621 includes a contact portion 641 (corresponding to a convex portion denoted by reference numeral 502 in FIG. 3), and the support portion 622 includes a contact portion 642.

  The contact portion 631 is located on the inner side in the axial direction of the charging roll 40 with respect to the center of the support portion 612 (the central portion in the extending direction). The contact portion 632 is located inside the charging roll 40 in the axial direction with respect to the center of the support portion 613. The contact portion 641 is located outside the cleaning roll 30 in the axial direction with respect to the center of the support portion 621. The contact part 642 is located outside the cleaning roll 30 in the axial direction with respect to the center of the support part 622.

  FIG. 6A shows a state in which the support members 500 and 600 are not inclined. In FIG. 6 (B), the axially outer sides of the support members 500 and 600 (in the direction far from the center of the supporting shaft) are lifted up and shown in an exaggerated state. In FIG. 6C, the axially inner side of the support members 500 and 600 (the direction close to the center of the supporting shaft) is lifted up, and the tilted state is exaggeratedly shown.

  According to this support structure, the charging roll 40 is in contact with the support part inside the center of the support parts 612 and 613, and the cleaning roll 30 is in contact with the support part outside the center of the support parts 621 and 622. For this reason, when considered on one side, the distance in the axial direction of the contact portion of the charging roll 40 and the cleaning roll 30 with respect to the support member can be made shorter than when this configuration is not adopted. Thereby, the change in the inter-axis distance between the charging roll rotating shaft 401 and the cleaning roll rotating shaft 301 in the state shown in FIGS. 6B and 6C is suppressed. Assuming that the charging roll 40 is in contact with the support part outside the center of the support parts 612 and 613, and the cleaning roll 30 is in contact with the support part inside the center of the support parts 621 and 622, charging on one side is assumed. The distance in the axial direction of the contact portion of the roll 40 and the cleaning all 30 with respect to the support member is longer than that in the configuration of FIG. For this reason, the change in the inter-axis distance between the charging roll rotating shaft 401 and the cleaning roll rotating shaft 301 in the state shown in FIGS. 6B and 6C is relatively large.

FIG. 7 is a graph showing an example of a simulated state of fluctuation of the inter-axis distance caused by the inclination of the support member. The “distance between the support portions in the axial direction” on the horizontal axis in FIG. 7 is the distance between the support position in the axial direction of the rotary shaft 401a for the charging roll and the support position of the rotary shaft 301a. The “distance fluctuation between axes” on the vertical axis in FIG. 7 is an average value of fluctuations in the distance between the charging roll rotating shaft 401 and the cleaning roll rotating shaft 301. Here, the initial value of the distance between the axes (the initial value of the distance between the charging roll rotating shaft 401 and the cleaning roll rotating shaft 301) is 10 mm, and the inclination angle indicated by θ ₁ in FIG. 5 is 5 °. The simulation is performed on the assumption that this is the case.

  As FIG. 7 shows, if the distance between the support parts of an axial direction is small, the distance fluctuation | variation between axes | shafts can be suppressed. As described with reference to FIG. 6, the charging roll 40 comes into contact with the support portion inside the support portions 612 and 613, and the cleaning roll 30 contacts the support portion outside the center portions of the support portions 621 and 622. I try to make contact. For this reason, the distance of the supporting member in the axial direction in FIG. 7 can be reduced as compared with the case of adopting a configuration that is not so, and the influence of the inclination of the supporting member on the fluctuation of the interaxial distance can be suppressed.

  FIG. 8 is a graph showing the results of the durability test. 8, the sample having the structure shown in FIG. 3 is A, and in the structure shown in FIG. 3, the sample having the structure without the gaps 503 a and 504 a is B and the structure without the gaps 503 a, 504 a, and 514 is provided. Is sample C. Note that the presence or absence of a gap in the corresponding portion of the support member 600 was the same as that of the support member 500. The vertical axis in FIG. 8 is the result of calculating the average value after measuring the amount of biting into the cleaning member 300 of the charging member 400 every 1 cm in the axial direction after this test. Note that the initial value of the amount of biting is 0.75 mm. From FIG. 8, the effect of providing the gaps 503a and 504a, the effect of providing the gaps 503a, 504a and 514, and the charging roll 40 contacts the support part inside the support parts 612 and 613, and the cleaning roll It can be confirmed that 30 is in contact with the support portion outside the center of the support portions 621 and 622.

(2) Other Embodiments In the structure illustrated in FIG. 4, the convex portion 512 is extended so as to be in contact with the outer periphery of the lower half of the charging roll rotating shaft 401 a. However, the convex portion 512 does not extend continuously and may be partially interrupted. That is, the convex portion 512 may be divided into a plurality of parts. In addition, the portion of the top of the convex portion 512 that contacts the charging roll rotating shaft 401a may not be flat in cross section and may be rounded. These are the same for the convex portions 502 and the like. Further, the pressure generating means may be a plate spring, a hydraulic cylinder or the like instead of the coil spring.

  In the example shown in FIG. 3, an example in which a gap is formed between the support structure portion of the charging roll rotating shaft 401 and the support structure portion of the rotating shaft 301 is shown, but the present invention is applied to the support structure of one of the rotating shafts. May be applied. That is, the present invention is applied to the support structure of the cleaning roll 30 and the support structure of the present invention is not applied to the charging roll 40, and the present invention is not applied to the support structure of the cleaning roll 30, and the present invention is applied to the charging roll 40. It is good also as either of the aspects which apply a support structure. Further, in the support structure of the charging roll rotating shaft 401, the shaft supporting structure of the present invention may be applied to only one of the charging roll rotating shafts 401a and 401b. Moreover, in the support structure of the rotating shaft 301, the shaft supporting structure of the present invention may be applied to only one of the rotating shafts 301a and 301b.

  The image forming apparatus 100 illustrated in FIG. 1 includes a photosensitive drum 103, a rotary developing device 101, a primary transfer roll 115, a driving roll 116, a charging roll 117, a conveyance roll for the paper conveyance system 124, and a rotating body. The next transfer rolls 126a and 126b, the fixing rolls 127a and 127b, and the roll of the discharge mechanism 128 are arranged, but the support structure of the present invention can be applied to one or a plurality of these rolls. In addition, the present invention can be applied to a support structure for a rotating body having the same structure as the roll exemplified above.

  For example, the present invention can also be used for a transfer unit, a fixing unit, a charging roll 117 for charging the intermediate transfer member 114, and the like. For example, if it is a transfer unit, this invention can be utilized for the combination of the transfer roll which comprises a transfer unit, and the cleaning roll which cleans this transfer roll. Further, for example, in the case of a fixing unit, the present invention can be used for a combination of a fixing roll (or an opposing roll) constituting the fixing unit and a cleaning roll for cleaning the transfer roll (opposing roll). Further, for example, in the case of the charging roll 117, the present invention can be used for a combination of the charging roll 117 and a cleaning roll for cleaning the charging roll 117.

  Hereinafter, an example when the present invention is applied to a transfer unit will be described. FIG. 1 shows a cleaning roll 131 for cleaning dirt on the secondary transfer roll 126b. The present invention can be used in a transfer roll unit including the secondary transfer roll 126b and the cleaning roll 131. That is, in the configuration shown in FIG. 3, the transfer roll 126 b is arranged instead of the charging roll 40, and the cleaning roll 131 shown in FIG. 3 is arranged instead of the cleaning roll 30. In this case, the transfer roller 126a is positioned on the photosensitive drum 103, the intermediate transfer member 114 and the printing paper are sandwiched between the transfer rollers 126a and 126b, and the toner image is transferred from the intermediate transfer member 114 to the printing paper. Is done. For the support structure and the like, the structure of FIG. 3 can be used as it is.

  The present invention can be used for an image holding unit or a rotating unit in an image forming apparatus.

1 is a conceptual diagram illustrating an example of an image forming apparatus using the invention. FIG. 2 is a block diagram illustrating a configuration of a control system of the image forming apparatus illustrated in FIG. 1. It is a conceptual diagram which shows the support structure of a charging roll and a cleaning roll. It is a perspective view which shows the outline | summary of a supporting member. It is a conceptual diagram which shows the state which the inclination of the support member produced. It is a conceptual diagram which shows the influence of the inclination of a supporting member. It is a graph which shows an example which simulated the state of change of the distance between axes. It is a graph which shows the result of an endurance test.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 103 ... Photosensitive drum, 103a ... Rotary shaft, 103b ... Rotary shaft, 30 ... Cleaning roll, 300 ... Cleaning member, 301 ... Cleaning roll rotary shaft, 301a ... Cleaning roll rotary shaft, 301b ... Cleaning roll rotary shaft, 40 ... Charging roll, 400 ... Charging member, 401 ... Charging roll rotating shaft, 401a ... Charging roll rotating shaft, 401b ... Charging roll rotating shaft, 401c ... End of charging roll rotating shaft 401a, 401c ... Charging roll End portion edge portion of the rotary shaft 401a, 500 ... support member, 500b ... wall surface inside the recess, 501 ... recess, 502 ... convex portion, 503 ... low surface portion, 504 ... low surface portion, 503a ... gap, 504a ... gap, 505 gap, 511 ... concave part, 512 ... convex part, 513 ... low surface part, 514 ... low surface part, 515 ... gap, 516 ... groove, 517 coil spring.

Claims (4)

A contacted member;
A first roll comprising a rotating shaft and a contact member disposed around the rotating shaft, wherein the first roll rotates around the rotating shaft and contacts the contacted member;
A support member comprising a first support part that contacts and supports the rotating shaft;
And a pressing means for pressing the support member against the contacted member,
The first support portion includes a contact portion that contacts the first roll and a non-contact portion that does not contact the first roll in a state where the support member is not inclined in the axial direction of the rotation shaft,
By gap is provided between the wall surface of the support member facing an end portion and said end portion of said rotary shaft together with the contact portion protrudes toward the rotation axis with respect to the non-contact portion, the rotating unit the support member, characterized in that the end of the previous SL rotating shaft support member is prevented from contacting when inclined in the axial direction of the rotary shaft. An image carrier for holding an image;
A charging roll rotating shaft and a charging member disposed around the charging roll rotating shaft;
A charging roll that rotates around the rotation axis for the charging roll and charges the surface of the image carrier;
A support member including a first support portion that contacts and supports the rotating shaft for the charging roll;
Pressing means for pressing the support member against the image carrier,
The first support portion includes a contact portion that is in contact with the charging roll and a non-contact portion that is not in contact with the charging member in a state where the support member is not inclined in the axial direction of the rotating shaft for the charging roll,
The contact portion protrudes toward the charging roll rotation shaft with respect to the non-contact portion, and a gap is formed between an end portion of the charging roll rotation shaft and the wall surface of the support member facing the end portion. by provided, an image, characterized in that said support member is so does not contact the end of the previous SL rotational axis charging roller to the support member when tilted in the axial direction of the for charging roll rotating shaft Holding unit. A first roll rotating shaft and a contact surface disposed around the first roll rotating shaft, wherein the first rotating shaft rotates around the first roll rotating shaft and contacts the contacted surface; Rolls of
A cleaning roll provided with a cleaning roll rotating shaft and a cleaning member disposed around the cleaning roll rotating shaft, and rotating around the cleaning roll rotating shaft to clean the first roll;
A support member comprising a first support portion that contacts and supports the first roll rotation shaft and a second support portion that contacts and supports the cleaning roll rotation shaft;
Pressing means for pressing the support member against the contacted surface,
The first support portion includes a contact portion that is in contact with the first roll and a non-contact portion that is not in contact with the support member when the support member is not inclined in the axial direction of the first roll rotation shaft. ,
The second support portion includes a contact portion that contacts the cleaning roll and a non-contact portion that does not contact the cleaning roll in a state where the support member is not inclined in the axial direction of the rotary shaft for the cleaning roll,
The contact portion of the first support portion projects toward the first roll rotation shaft with respect to the non-contact portion of the first support portion, so that the support member rotates the first roll. the end of the first roll rotating shaft before Symbol the support member is prevented from contacting when inclined in the axial direction of the shaft,
The contact portion of the second support portion protrudes toward the cleaning roll rotation shaft with respect to the non-contact portion of the second support portion, so that the support member is in the axial direction of the cleaning roll rotation shaft. wherein the support member is an end portion of the front Symbol rotation axis cleaning roller so as not to contact when tilted by,
The contact portion of the first support portion is disposed inside the axial direction of the first roll with respect to the center of the first support portion,
The rotating body unit, wherein the contact portion of the second support portion is disposed outside the cleaning roll in the axial direction with respect to the center of the second support portion. An image carrier for holding an image;
A charging roll comprising a charging roll rotating shaft and a charging member arranged around the charging roll rotating shaft, and rotating around the charging roll rotating shaft to charge the surface of the image carrier;
A cleaning roll provided with a cleaning roll rotating shaft and a cleaning member disposed around the cleaning roll rotating shaft, wherein the cleaning roll rotates around the cleaning roll rotating shaft and cleans the charging roll;
A support member comprising a first support part that contacts and supports the charging roll rotating shaft and a second support part that contacts and supports the cleaning roll rotating shaft;
Pressing means for pressing the support member against the image carrier,
The first support portion includes a contact portion that is in contact with the charging roll and a non-contact portion that is not in contact with the charging member in a state where the support member is not inclined in the axial direction of the rotating shaft for the charging roll,
The second support portion includes a contact portion that contacts the cleaning roll and a non-contact portion that does not contact the cleaning roll in a state where the support member is not inclined in the axial direction of the rotary shaft for the cleaning roll,
The contact portion of the first support portion protrudes toward the rotation shaft for the charging roll with respect to the non-contact portion of the first support portion, so that the support member is in the axial direction of the rotation shaft for the charging roll. wherein the support member is an end portion of the front Symbol for charging roll rotating shaft so as not to contact when tilted by,
The contact portion of the second support portion protrudes toward the cleaning roll rotation shaft with respect to the non-contact portion of the second support portion, so that the support member is in the axial direction of the cleaning roll rotation shaft. wherein the support member is an end portion of the front Symbol rotation axis cleaning roller so as not to contact when tilted by,
The contact portion of the first support portion is disposed inside the charging roll in the axial direction with respect to the center of the first support portion,
The image carrier unit according to claim 1, wherein the contact portion of the second support portion is arranged outside in the axial direction of the cleaning roll with respect to the center of the second support portion.

Images