JP2009265127A - Electrophotographic photoreceptor - Google Patents

Abstract

An electrophotographic photosensitive member capable of stabilizing a resistance value of a contact portion between a conducting member and a conductive support shaft and suppressing generation of wear and noise.
A photosensitive drum 61 includes a drum body 110 having a cylindrical conductive rotating base 111 and a photosensitive layer 112 on which an electrostatic latent image is formed on the outer peripheral surface of the conductive rotating base 111 by exposure. A conductive drum shaft 120 disposed on the central axis of the drum main body 110 and a conductive member 140 that conducts the inner peripheral surface 110A of the drum main body 110 and the drum shaft 120 are provided. The conducting member 140 supports the roller part 161 that rolls on the peripheral surface of the drum shaft 120, supports the roller part 161 at one end via the support part 162, and contacts the inner peripheral surface 110A of the drum main body 110 at the other end. And a conductive connecting portion 150 that rotates together with the drum body 110.
[Selection] Figure 3

Description

  The present invention relates to an electrophotographic photoreceptor.

  In general, a photosensitive drum provided in an image forming apparatus such as a laser printer includes a drum body having a photosensitive layer on the surface (outer peripheral surface) of a cylindrical conductive rotating base, and flanges engaged with both ends of the drum body. And a drum shaft inserted into each flange along the central axis of the drum body. The drum shaft is supported by the image forming apparatus main body, and the drum main body is supported by the drum shaft via each flange so as to be relatively rotatable.

  By the way, in such a photosensitive drum, in order to form a good electrostatic latent image on the photosensitive layer, it is necessary to connect the drum body (conductive rotating base) to the ground. For example, in Patent Document 1, a plate-shaped ground electrode extending from the inner periphery of a ring-shaped ground plate electrically connected to the inner peripheral surface of the drum body toward the drum shaft is in sliding contact with the drum shaft. A configuration is disclosed in which the drum body and the drum shaft can be electrically connected.

JP 2000-181286 A

  However, in the conventional configuration described above, since the ground electrode (conducting member) and the drum shaft (conductive support shaft) are in sliding contact with the rotation of the drum body, the sliding contact portion (contact) between the conductive member and the conductive support shaft is provided. Part)), the resistance value increases, and the drum body and the conductive support shaft may be in a non-conductive state. In addition, the conductive member and the conductive support shaft are in sliding contact with each other, thereby causing a problem that the conductive member and the conductive support shaft are worn and the life is shortened, and that a frictional sound (noise) is generated.

  Accordingly, an object of the present invention is to provide an electrophotographic photosensitive member that can stabilize the resistance value of the contact portion between the conducting member and the conductive support shaft, and can suppress the generation of wear and noise. And

  In order to achieve the above-described object, the present invention provides a drum body having a cylindrical conductive rotating base, and a photosensitive layer on which an electrostatic latent image is formed by exposure on the outer peripheral surface of the conductive rotating base, A conductive support shaft disposed on a central axis of the drum body; and a conductive member that conducts the inner peripheral surface of the drum main body and the conductive support shaft. The conductive member has a periphery of the conductive support shaft. A conductive rolling element that rolls on the surface, and a conductive connection portion that supports the conductive rolling element at one end and rotates with the drum body while contacting the inner peripheral surface of the drum body at the other end. It is characterized by that.

  Here, in the present invention, the conductive connecting part supports the conductive rolling element when the conductive connecting part itself supports the conductive rolling element so as to be able to roll directly, and the conductive rolling element can roll. This includes both cases where the conductive connection portion indirectly supports the conductive rolling element via a support member or the like that supports the conductive rolling element.

  According to the electrophotographic photosensitive member configured as described above, the conductive rolling member of the conductive member rolls on the peripheral surface of the conductive support shaft by the rotation of the drum body. Compared to the configuration in which the sliding contact is made, the change in the surface state of the contact portion between the conductive member and the conductive support shaft can be reduced. In addition, since the conductive rolling element rolls on the peripheral surface of the conductive support shaft, it is possible to suppress wear of the conductive support shaft and the conductive rolling element and generation of noise at the contact portion.

  According to the electrophotographic photosensitive member of the present invention, since the conductive rolling element rolls on the peripheral surface of the conductive support shaft, the change in the surface state of the contact portion between the conductive member and the conductive support shaft can be reduced. It is possible to stabilize the resistance value of the contact portion and to suppress the generation of wear and noise.

[First Embodiment]
<Overall configuration of laser printer>
Next, a first embodiment of the present invention will be described in detail with reference to the drawings as appropriate. In the drawings to be referred to, FIG. 1 is a cross-sectional view showing an overall configuration of a laser printer as an example of an image forming apparatus.
Here, in the following description, the direction will be described with reference to the user when using the laser printer. That is, in FIG. 1, the right side toward the paper surface is the “front” side, the left side toward the paper surface is the “rear” side, the back side toward the paper surface is the “right” side, and the front side toward the paper surface is “left”. ”Side. In addition, the vertical direction toward the page is the “vertical” direction.

  As shown in FIG. 1, the laser printer 1 includes a main body housing 2, a paper feeding unit 3 for feeding paper P (recording sheet), an exposure device 4, and a toner image (development) on the paper P. The process cartridge 5 for transferring the agent image) and the fixing device 8 for thermally fixing the toner image on the paper P are mainly provided.

  The paper feed unit 3 is disposed in the lower part of the main body housing 2 and is detachably mounted on the main body housing 2, and is swingable provided on the front side of the paper feed tray 31. A paper pressing plate 32, a paper feed roller 33, a paper feed pad 34, paper dust removing rollers 35 and 36, and a registration roller 37 provided mainly on the upper front side of the paper feed tray 31 are mainly provided. The paper P in the paper feed tray 31 is brought close to the paper feed roller 33 by the paper pressing plate 32 and sent out by the paper feed roller 33 and the paper feed pad 34, and the paper dust removing rollers 35 and 36 and the registration roller 37 are moved. After passing, they are conveyed one by one to a process cartridge 5 described later.

  The exposure apparatus 4 is arranged at the upper part in the main body housing 2 and mainly includes a laser light emitting unit (not shown), a polygon mirror 41 that is rotationally driven, lenses 42 and 43, and reflecting mirrors 44, 45, and 46. In preparation. The laser light based on the image data emitted from the laser light emitting part is reflected or passed through the polygon mirror 41, the lens 42, the reflecting mirrors 44 and 45, the lens 43, and the reflecting mirror 46 in this order, as indicated by the chain line, and is electrophotographic photosensitive. The surface of the photosensitive drum 61 as an example of the body is irradiated by high-speed scanning.

  The process cartridge 5 is disposed below the exposure apparatus 4 and is configured to be detachably mounted from an opening formed when the front cover 21 provided on the front side of the main body housing 2 is opened. The process cartridge 5 includes a drum cartridge 6 and a developing cartridge 7.

  The drum cartridge 6 mainly includes a photosensitive drum 61, a transfer roller 62, and a charger 63, which are rotatably supported by the drum case 60, in a hollow drum case 60 constituting an outer frame. A detailed configuration of the photosensitive drum 61 will be described later.

  The developing cartridge 7 is configured to be detachably attached to the drum cartridge 6 (drum case 60). The developing cartridge 7 mainly includes a developing roller 71 and a supply roller 72 rotatably supported by the developing case 70 and a layer thickness regulating blade 73 in the developing case 70, and has a toner containing portion 74. Yes.

  In the process cartridge 5 configured as described above, the surface of the photosensitive drum 61 is uniformly charged by the charger 63 and then exposed by high-speed scanning of the laser light from the exposure device 4. Thereby, the potential of the exposed portion is lowered, and an electrostatic latent image based on the image data is formed.

  At this time, the toner in the toner container 74 is supplied onto the supply roller 72 and is supplied onto the developing roller 71 by the sliding contact between the supply roller 72 and the developing roller 71. The toner supplied onto the developing roller 71 enters between the developing roller 71 and the layer thickness regulating blade 73 by the rotation of the developing roller 71 and is carried on the developing roller 71 as a thin layer having a constant thickness.

  The toner carried on the developing roller 71 is supplied to the electrostatic latent image on the surface of the photoconductive drum 61 when the developing roller 71 and the photoconductive drum 61 face each other. As a result, the electrostatic latent image on the surface of the photosensitive drum 61 is visualized and a toner image is formed. Then, the sheet P is conveyed between the photosensitive drum 61 and the transfer roller 62, whereby the toner image on the surface of the photosensitive drum 61 is transferred onto the sheet P.

  The fixing device 8 is disposed behind the process cartridge 5 (on the downstream side in the conveyance direction of the paper P), and is disposed so as to face the heating roller 81 and sandwich the paper P between the heating roller 81 and the heating roller 81. The apparatus mainly includes a pressure roller 82 and a pair of conveyance rollers 83 provided on the downstream side of the heating roller 81 and the pressure roller 82 in the conveyance direction of the paper P. The toner transferred onto the paper P is thermally fixed while the paper P passes between the heating roller 81 and the pressure roller 82. The sheet P on which the toner image has been thermally fixed is conveyed to the sheet discharge path 91 by the conveyance roller 83 and the flapper 84, and the discharge formed on the upper surface of the main body housing 2 by the pair of sheet discharge rollers 92 from the sheet discharge path 91. The paper is discharged onto the paper tray 22.

<Configuration of photosensitive drum>
Next, a detailed configuration of the photosensitive drum 61 as an example of the electrophotographic photosensitive member of the present invention will be described. 2A and 2B are views showing the appearance of the photosensitive drum, FIG. 3A is a sectional view of the photosensitive drum according to the first embodiment, and FIG. 2B is a perspective view of the drum shaft and the conducting member.

  As shown in FIG. 2, the photosensitive drum 61 includes a drum body 110, a drum shaft 120 as an example of a conductive support shaft disposed along the central axis of the drum body 110, and each end of the drum body 110. And flanges 130 and 139 engaged with each other.

  The drum main body 110 includes a conductive rotating base 111 (see FIG. 3A) having a cylindrical shape (a cylindrical shape coaxial with the drum shaft 120) formed of a conductive material such as aluminum. A photosensitive layer 112 on which an electrostatic latent image is formed by exposure is formed on the outer peripheral surface of the conductive rotating base 111.

  The drum shaft 120 is a rod-like (substantially columnar) member made of a conductive material such as metal, and both ends are supported by the drum case 60 of the drum cartridge 6. When the drum cartridge 6 (process cartridge 5) is attached to the main body housing 2, the drum shaft 120 is supported by the main body housing 2 (device main body). The drum shaft 120 is electrically grounded by a known configuration.

The flanges 130 and 139 are formed of an insulating resin material, and are respectively attached to end portions of the drum main body 110 so as not to rotate with respect to the drum main body 110.
As shown in FIG. 3A, the flange 130 is integrally formed with a flange main body 131 and a bearing 132 through which the drum shaft 120 is inserted.

  The flange main body 131 has an insertion portion 133 formed in a substantially cylindrical shape, and a gear portion 134 that extends axially outward from the insertion portion 133. A part of the inner periphery of the insertion portion 133 and the inner periphery of the gear portion 134 form a communicating through hole 131A, and the bearing 132 is supported by the through hole 131A.

The insertion portion 133 is a portion that is inserted into the drum main body 110, and a cutout portion 133 </ b> B having a rectangular cross-sectional view is formed over the entire circumference of the insertion portion 133 on the outer peripheral side of the end portion 133 </ b> A.
The gear portion 134 has an outer diameter larger than the outer diameter of the drum body 110, and gear teeth 134A (see FIG. 2) are formed on the outer peripheral surface.

  As described above, the flanges 130 and 139 are non-rotatably attached to both ends of the drum body 110 and are rotatably supported by the drum shaft 120, so that the drum body 110 is connected to the drum shaft via the flanges 130 and 139. 120 is supported so as to be relatively rotatable. The drum body 110 and the flanges 130 and 139 (photosensitive drums) are input to the gear portion 134 of the flange 130 from a driving source such as a motor (not shown) provided in the main body housing 2. 61) is driven to rotate.

  As shown in FIGS. 3A and 3B, the photosensitive drum 61 includes a conductive member that conducts the drum main body 110 and the drum shaft 120 in addition to the drum main body 110, the drum shaft 120, and the flanges 130 and 139. 140. In the present embodiment, a configuration in which one conductive member 140 is provided only on the flange 130 side will be described.

  The conducting member 140 is a member that conducts between the inner peripheral surface 110 </ b> A of the drum main body 110 and the drum shaft 120, and includes a conductive connecting portion 150 and a conductive roller 160.

  The conductive connection portion 150 includes a ring-shaped portion 151, four contact portions 152 extending radially outward from the outer periphery of the ring-shaped portion 151, and one arm portion 153 extending radially inward from the inner periphery of the ring-shaped portion 151. And have. Such a conductive connection part 150 is formed using a plate-like member made of a material having conductivity and springiness such as phosphor bronze.

  The ring-shaped portion 151 is formed so that the outer diameter is smaller than the inner diameter of the drum body 110 and the inner diameter is larger than the maximum outer diameter of the drum shaft 120. One end surface of the ring-shaped portion 151 is supported by the end portion 133 </ b> A of the flange 130 in the drum main body 110. The ring-shaped portion 151 may simply abut against the end portion 133A, may be locked by an engagement portion provided on the ring-shaped portion 151 and the end portion 133A, or may be screwed. Or may be fixed with an adhesive or the like.

  The contact portions 152 have a substantially triangular shape, and are provided so that the contact portions 152 are equidistant from each other, that is, at the same angle (90 degrees) with respect to the center of the ring-shaped portion 151. The distance between the tip portions of the contact portions 152 and 152 facing each other is set to be larger than the inner diameter of the drum main body 110.

  When the conductive connecting portion 150 is inserted into the drum body 110, the contact portion 152 abuts on the inner peripheral surface 110A and bends to the opposite side (left side in FIG. 3A) to the original direction. The conductive connecting portion 150 (conducting member 140) is supported in the drum main body 110 by a force for returning to the shape of the drum body 110. Thereby, the conduction member 140 can be rotated together with the drum main body 110 as the drum main body 110 rotates. Further, the conductive member 140 and the drum main body 110 are electrically connected by the contact portion 152 and the inner peripheral surface 110A being in contact with each other. Since the bent contact portion 152 enters the notch 133B, no force acts in the direction in which the ring-shaped portion 151 is separated from the end portion 133A (in the axial direction).

  The arm portion 153 extends radially inward from a position facing the one contact portion 152 in the inner periphery of the ring-shaped portion 151, and further curves toward the center (axially inner side) of the drum main body 110. The arm portion 153 supports the conductive roller 160 at an end portion. The arm portion 153 is configured to act as a leaf spring, and biases the roller portion 161 toward the drum shaft 120.

The conductive roller 160 includes a roller portion 161 as an example of a conductive rolling element, and a support portion 162 that rotatably supports the roller portion 161. The roller part 161 and the support part 162 are made of a conductive material.
The roller unit 161 includes a cylindrical roller body 161A that contacts the circumferential surface of the drum shaft 120, and a support shaft 161B that rotatably supports the roller body 161A.

  The support portion 162 has a substantially U shape when viewed from the front, and supports the support shaft 161B of the roller portion 161 in a non-rotatable manner. As for this support part 162, the edge part of the arm part 153 is being fixed to the upper surface shown to Fig.3 (a). The end portion of the arm portion 153 and the support portion 162 are fixed by, for example, screwing, welding, adhesion with a conductive adhesive or tape, or the like.

The effects of the photosensitive drum 61 configured as described above will be described.
When the driving force is input to the gear unit 134 during the operation of the laser printer 1, the photosensitive drum 61 (the drum body 110 and the flanges 130 and 139) rotates. As a result, the conductive connecting portion 150 supported by the drum main body 110 rotates, and the conductive roller 160 supported by the arm portion 153 of the conductive connecting portion 150 rotates around the drum shaft 120. At this time, the roller portion 161 of the conductive roller 160 rolls on the peripheral surface of the drum shaft 120. Thus, the drum main body 110 and the drum shaft 120 are electrically connected via the conducting member 140, whereby the drum main body 110 is electrically grounded.

  According to this embodiment, since the conductive roller 160 of the conductive member 140 rolls on the peripheral surface of the drum shaft 120, the conductive member 140 and the drum are compared with the conventional configuration in which the drum shaft and the ground electrode are in sliding contact. The change in the surface state of the contact portion with the shaft 120 is reduced. Thereby, since the resistance value of the contact portion can be stabilized, it is possible to prevent the drum main body 110 and the drum shaft 120 from being in a non-conductive state, and the drum main body 110 and the drum shaft 120 are in a conductive state. Can be secured satisfactorily. As a result, a good electrostatic latent image can be formed on the photosensitive layer 112 of the photosensitive drum 61, and the image quality of the laser printer 1 having such a photosensitive drum 61 can be improved.

  In addition, since the conductive roller 160 rolls on the peripheral surface of the drum shaft 120, wear of the drum shaft 120 and the conductive roller 160 can be suppressed, so that the drum shaft 120 and the conductive member 140 (roller portion 161) can be prevented. Long life can be achieved. Further, since the generation of noise at the contact portion can be suppressed, the operating state of the laser printer 1 including the photosensitive drum 61 can be kept good.

  Further, since the roller portion 161 is biased toward the drum shaft 120 by the arm portion 153 of the conductive connection portion 150 that acts as a leaf spring, the contact between the roller portion 161 and the drum shaft 120 can be more reliably performed. Can be secured. Furthermore, by adopting a roller (roller portion 161) as an example of the conductive rolling element, it is possible to roll on the peripheral surface of the drum shaft 120 satisfactorily.

  As described above, in the present embodiment, the configuration in which one conductive member 140 is provided only on the flange 130 side has been described, but the present embodiment is not limited to this. For example, the conduction member 140 may be provided on both the flange 130 side and the flange 139 side, or three or more may be provided in the drum main body 110.

  Here, a modified example of the present embodiment will be described. 4A is a cross-sectional view of the photosensitive drum according to the first modification, FIG. 4B is a perspective view of the drum shaft and the conductive member, and FIG. 5A is a photosensitive body according to the second modification. It is sectional drawing of a drum, (b) is a perspective view of a drum axis | shaft and a conduction member. In addition, since the modification of this embodiment mainly changed the structure of the conduction | electrical_connection member, the same code | symbol shall be attached | subjected about the component similar to above-described embodiment, and the description shall be abbreviate | omitted.

  As shown in FIGS. 4A and 4B, the conductive member 141 according to the first modification has conductive connection parts 150 and 170 and a conductive roller 180.

  The conductive connection portion 170 is disposed closer to the center of the drum body 110 than the conductive connection portion 150 with a predetermined distance from the conductive connection portion 150. The conductive connection portion 170 includes a ring-shaped portion 151, four contact portions 152, and one arm portion 173 that extends radially inward from the inner periphery of the ring-shaped portion 151. Such a conductive connecting portion 170 is also formed using a plate-like member made of a material having conductivity and spring property.

  The arm portion 173 extends radially inward from a position facing the one contact portion 152 in the inner periphery of the ring-shaped portion 151, and further curves toward the end portion (axially outer side) of the drum main body 110. . The arm portion 173 supports the conductive roller 180 at the end. The arm portion 173 is also configured to act as a leaf spring, and biases the roller portion 181 toward the drum shaft 120.

  The conductive roller 180 includes a cylindrical roller portion 181 (conductive rolling element) that contacts the peripheral surface of the drum shaft 120 and a support shaft 182 that rotatably supports the roller portion 181. The roller part 181 and the support shaft 182 are made of a conductive material.

  The support shaft 182 is formed in a cylindrical shape in appearance, and a hole 182A that can be engaged with the ends of the arm portions 153 and 173 is formed at both ends. The support shaft 182 is non-rotatably supported by the conductive connection portions 150 and 170 via the arm portions 153 and 173 by engaging the arm portions 153 and 173 with the hole portion 182A.

  In the conductive member 141 configured as described above, the conductive connection parts 150 and 170 supported by the drum body 110 are rotated by the rotation of the drum body 110, and the support shaft 182 is supported by the arm parts 153 and 173. Rotates around the drum shaft 120. At this time, the roller portion 181 rolls on the peripheral surface of the drum shaft 120 using the support shaft 182 as a rotation axis.

  As shown in FIGS. 5A and 5B, the conductive member 142 according to the second modification has a conductive connection portion 190 and a conductive roller 160.

  The conductive connecting portion 190 is formed of a long plate-like member having conductivity and spring property, and is substantially perpendicular to the contact portion 191 that is linear in a side view and downward from the contact portion 191 in FIG. The arm portion 192 extends toward the center of the drum main body 110 (inner side in the axial direction).

  Here, the insertion portion 133 ′ of the flange 130 ′ (flange main body portion 131 ′) is not formed with the notch 133 B as in the flange 130 of the first embodiment, and instead the contact portion 191 is provided. An engaging recess 133C is formed. The concave portion 133C is provided so that the contact portion 191 and the inner peripheral surface 110A come into contact with each other by attaching a flange 130 'having the contact portion 191 engaged with the concave portion 133C to one end of the drum body 110. The conductive connecting portion 190 is fixed to the flange 130 ′ with a screw 193.

  The arm part 192 supports the support part 162 of the conductive roller 160 at the end part. The end portion of the arm portion 192 and the support portion 162 are fixed by, for example, screwing, welding, adhesion with a conductive adhesive or tape, or the like. The arm portion 192 is also configured to act as a leaf spring, and biases the roller portion 161 toward the drum shaft 120.

  In the conductive member 142 configured as described above, the conductive connecting portion 190 supported by the drum main body 110 is rotated by the rotation of the drum main body 110, and the conductive roller 160 supported by the arm portion 192 is further rotated by the drum shaft 120. Rotate around. At this time, the roller portion 161 of the conductive roller 160 rolls on the peripheral surface of the drum shaft 120.

[Second Embodiment]
Next, a second embodiment of the present invention will be described in detail with reference to the drawings as appropriate. 6A is a cross-sectional view of a photosensitive drum according to the second embodiment, FIG. 6B is an XX cross-sectional view of FIG. 6A, and FIG. 7 is a cross-sectional view of the second embodiment. It is sectional drawing of the photoreceptor drum which concerns on a modification. In this embodiment, since the configuration of a part of the photosensitive drum according to the first embodiment is changed, the same components as those in the first embodiment are denoted by the same reference numerals. The description will be omitted. Also in this embodiment, a configuration in which a conducting member is provided only on the flange 130 side will be described.

  The flange 230 is attached to one end of the drum body 110 so as not to rotate with respect to the drum body 110. The flange 230 is mainly composed of a flange main body portion 231 formed from an insulating resin material and a bearing 132.

  The flange main body portion 231 has an insertion portion 233 formed in a substantially cylindrical shape and a gear portion 134. A part of the inner periphery of the insertion portion 233 and the inner periphery of the gear portion 134 form a communicating through hole 231A, and the bearing 132 is supported by the through hole 231A.

  The insertion portion 233 is a portion that is inserted into the drum main body 110. The insertion portion 233 is formed with three wall portions 233A, 233B, and 233C extending radially inward from the inner periphery (portion excluding the through hole 231A). Specifically, the wall portion 233A is provided so as to face the end surface 233D of the insertion portion 233 in the axial direction, and the wall portions 233B and 233C face each other and are substantially perpendicular to the wall portion 233A and the end surface 233D. It is provided so as to be connected. A conductive member 240 (conductive roller 160), which will be described later, is engaged in a space surrounded by the walls 233A, 233B, 233C and the end surface 233D.

The conductive member 240 includes a coil spring 250 as another example of the conductive connection portion and a conductive roller 160.
The coil spring 250 is made of a conductive material, and has one end fixed to the support portion 162 of the conductive roller 160 and the other end passing through a through hole 233E provided in the insertion portion 233 to the inner peripheral surface 110A of the drum body 110. The contact is made in a slightly compressed state. Thereby, the inner peripheral surface of the drum main body 110 and the drum shaft 120 are electrically connected via the coil spring 250 and the conductive roller 160. The roller 161 is urged toward the drum shaft 120 by the force of returning to the original shape of the compressed coil spring 250, so that the roller 161 and the drum shaft 120 are more reliably brought into contact with each other. Can do.

  The conductive member 240 configured in this manner is engaged with the space surrounded by the wall portions 233A, 233B, 233C and the end surface 233D of the flange 230 with the conductive roller 160. It rotates around the drum shaft 120 together with the drum body 110. At this time, the roller portion 161 of the conductive roller 160 rolls on the peripheral surface of the drum shaft 120.

  In addition, the electroconductive rolling element of this embodiment is not limited to a roller, For example, a spherical body may be sufficient. As shown in FIG. 7, the conductive ball 260 includes a sphere 261 as another example of the conductive rolling element, and a support portion 262 that supports the sphere 261 so that it can roll. The spherical body 261 and the support portion 262 are made of a conductive material. Even such a spherical body 261 can roll on the peripheral surface of the drum shaft 120 satisfactorily.

  The size of the space surrounded by the wall portions 233A, 233B, 233C and the end surface 233D of the flange 230 with which the conducting members 240, 241 engage is the size of the conductive rolling element, specifically, the support portions 162, 262. It can change suitably according to the magnitude | size. Further, the conducting members 240 and 241 may be provided at both ends of the drum main body 110.

[Third Embodiment]
Next, a third embodiment of the present invention will be described in detail with reference to the drawings as appropriate. In the drawings to be referred to, FIG. 8 is a cross-sectional view of a photosensitive drum according to the third embodiment. In addition, since this embodiment also changes a part of the configuration of the photosensitive drum according to the first embodiment, the same components as those in the first embodiment are denoted by the same reference numerals, The description will be omitted.

  As shown in FIG. 8, the flange 330 is attached to one end of the drum body 110 so as not to rotate with respect to the drum body 110. The conducting member 340 includes a conductive connecting portion 350 and a roller bearing 360 as another example of the conductive rolling element.

  The conductive connection portion 350 includes a cylindrical support portion 351 that supports the roller bearing 360, a cylindrical contact portion 352 whose outer peripheral portion contacts the inner peripheral surface 110A when inserted into the drum main body 110, and a support. It is integrally formed from the connection part 353 which connects the part 351 and the contact part 352. FIG. The conductive connection portion 350 is integrated with the flange 330 when the support portion 351 is inserted into the through hole 331A of the flange 330, and is inserted into the drum body 110 together with the flange 330 in this state.

  The roller bearing 360 includes a plurality of roller portions 361 and an outer ring 362 that is formed in a ring shape having a concave portion on the inner peripheral surface and rotatably supports the roller portion 361, and rotatably supports the drum shaft 120. is doing. The roller bearing 360 (the roller portion 361 and the outer ring 362) is made of a conductive material.

  Thereby, the inner peripheral surface 110 </ b> A of the drum main body 110 and the drum shaft 120 are electrically connected via the conductive connection portion 350 and the roller bearing 360. The conducting member 340 employing such a roller bearing 360 may be provided only on the flange 130 or may be provided on both the flanges 130 and 139.

  In the conductive member 340 configured as described above, when a driving force is input to the gear portion 334 of the flange 330, each roller portion 361 of the roller bearing 360 rolls on the peripheral surface of the drum shaft 120. Thereby, the flange 330 and the drum main body 110 rotate. By adopting such a roller bearing 360, it is possible to roll on the peripheral surface of the drum shaft 120 satisfactorily. Instead of the roller bearing 360, a ball bearing or the like in which all components are made of a conductive material may be employed.

  As mentioned above, although embodiment of this invention was described, this invention is not limited to above-described embodiment. About a concrete structure, it can change suitably in the range which does not deviate from the meaning of this invention.

  In the above-described embodiment, in order to bias the conductive rolling elements such as the roller portion 161 and the spherical body 261 toward the drum shaft 120, the conductive portion having the arm portion 153 that acts as a leaf spring as the conductive connection portion. Although the example which employ | adopted the connection part 150 etc. and the coil spring 250 was shown, this invention is not limited to this. That is, the conductive connecting portion of the present invention is particularly limited as long as it is a member that can urge the conductive rolling portion toward the conductive support shaft or at least part of such a configuration. Is not to be done.

  In the above-described embodiment, examples in which the roller portions 161 and 181, the spherical body 261, the roller bearing 360, and the like are adopted as examples of the conductive rolling elements have been shown, but the conductive rolling elements of the present invention are limited to this. It is not a thing. That is, any rolling element having conductivity that can roll well on the peripheral surface of the conductive support shaft can be adopted.

  In the above-described embodiment, the conductive connection parts 150 and 241 indirectly support the conductive rolling elements such as the roller part 161 and the spherical body 261 via the support parts 162 and 262 that support the rolling. Although shown, the present invention is not limited to this. That is, it is good also as a structure which the electroconductive connection part itself supports an electroconductive rolling element so that rolling is possible directly.

  For example, a support member that supports the roller portion 161 in a rollable manner is provided integrally with the conductive connection portion 150 at the end of the arm portion 153 of the conductive connection portion 150 shown in FIG. It is good also as a structure supported so that rolling is possible. Moreover, it is good also as a structure which makes the edge part of the arm parts 153 and 173 of the electroconductive connection parts 150 and 170 shown in FIG. 4 cylindrical shape, and supports the roller part 181 so that rolling is possible in this cylindrical part. Furthermore, it is good also as a structure which integrally provides the support member which supports the spherical body 261 so that rolling is possible at the end of the coil spring 250 shown in FIG. 7, and supports the spherical body 261 by this supporting member.

  In the above-described embodiment, the laser printer 1 that forms a monochromatic image is exemplified as an example of the image forming apparatus provided with the photosensitive drum 61 (electrophotographic photosensitive member). However, the image forming apparatus provided with the electrophotographic photosensitive member is illustrated as an example. It is not limited to this. For example, it may be a copying machine or a multifunction machine that forms a single color image, or may be a printer, a copying machine, or a multifunction machine that forms a multicolor image (color image).

1 is a cross-sectional view illustrating an overall configuration of a laser printer as an example of an image forming apparatus. It is a figure which shows the external appearance of a photoconductive drum. (A) is sectional drawing of the photoconductive drum which concerns on 1st Embodiment, (b) is a perspective view of a drum axis | shaft and a conduction member. (A) is sectional drawing of the photoconductive drum which concerns on the 1st modification of 1st Embodiment, (b) is a perspective view of a drum axis | shaft and a conduction member. (A) is sectional drawing of the photosensitive drum which concerns on the 2nd modification of 1st Embodiment, (b) is a perspective view of a drum axis | shaft and a conduction member. (A) is sectional drawing of the photoconductive drum which concerns on 2nd Embodiment, (b) is XX sectional drawing of (a). It is sectional drawing of the photoconductor drum which concerns on the modification of 2nd Embodiment. It is sectional drawing of the photoconductor drum which concerns on 3rd Embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Laser printer 61 Photosensitive drum 110 Drum main body 110A Inner peripheral surface 111 Conductive rotating base 112 Photosensitive layer 120 Drum shaft 140 Conductive member 141 Conductive member 142 Conductive member 150 Conductive connecting portion 153 Arm portion 161 Roller portion 170 Conductive connecting portion 173 Arm unit 181 Roller unit 190 Conductive connection unit 192 Arm unit 240 Conducting member 241 Conducting member 250 Coil spring 261 Sphere 340 Conducting member 350 Conductive connecting unit 360 Roller bearing

Claims (7)

A drum body having a cylindrical conductive rotating base and a photosensitive layer on which an electrostatic latent image is formed by exposure on the outer peripheral surface of the conductive rotating base;
A conductive support shaft disposed on the central axis of the drum body;
A conductive member that conducts the inner peripheral surface of the drum body and the conductive support shaft;
The conducting member is
A conductive rolling element that rolls on a peripheral surface of the conductive support shaft;
An electrophotographic photosensitive member comprising: an electroconductive photoreceptor having one end supporting the conductive rolling element and the other end contacting an inner peripheral surface of the drum body and rotating together with the drum body.   2. The electrophotographic photosensitive member according to claim 1, wherein the conductive connection portion biases the conductive rolling element toward the conductive support shaft.   The electrophotographic photosensitive member according to claim 2, wherein the conductive connection portion includes a conductive leaf spring.   The electrophotographic photosensitive member according to claim 2, wherein the conductive connection portion is a conductive coil spring.   The electrophotographic photosensitive member according to any one of claims 1 to 4, wherein the conductive rolling element is a conductive roller.   The electrophotographic photosensitive member according to claim 1, wherein the conductive rolling element is a conductive sphere.   2. The electrophotographic photosensitive member according to claim 1, wherein the conductive rolling element is a conductive roller bearing.

Images