JP4507695B2 - Drum conduction mechanism and image forming apparatus - Google Patents

Description

  The present invention relates to a drum conduction mechanism and an image forming apparatus including the drum conduction mechanism.

  As an image forming method of the image forming apparatus, a method using a known electrophotographic process is known. In a known electrophotographic process, an image is formed on a recording medium such as a recording paper by the following process.

  The photosensitive drum is uniformly charged to a predetermined potential with a charger while rotating the photosensitive drum in which a thin film of photoconductive (a substance whose electric resistance decreases when exposed to light) is formed on the surface of the metallic drum. . The charged photosensitive drum is exposed according to image information. Since the photoconductive thin film is formed on the surface of the photosensitive drum, the resistance of the exposed portion is lowered. Therefore, charging of the exposed part is canceled and a latent image is formed. The latent image is developed with a developing device to form a toner image on the photosensitive drum. This toner image is transferred to the recording paper by a transfer device, and the toner image is fixed on the recording paper by a fixing device. Further, before charging by the charger, residual toner after transfer is removed by a cleaning mechanism.

  Now, in order to cancel the charging of the exposed portion and form a latent image, it is necessary to ground the photosensitive drum. Therefore, the photosensitive drum is grounded by bringing the conductive member into contact with the rotating shaft shaft of the photosensitive drum and the inner wall of the photosensitive drum so as to be conductive, and connecting the rotating shaft shaft to the ground of the image forming apparatus main body. .

The conductive member is inserted into the end portion of the photosensitive drum and attached to a flange through which the rotation shaft is passed. (For example, refer to Patent Document 1).
JP-A-1-65573

  However, in the method described in Japanese Patent Laid-Open No. 1-65573, it is necessary to fix the conductive member to the flange by screwing it after the conductive member is attached to the flange. For this reason, work efficiency was not good.

  The present invention has been made to solve the above-described problems, and an object thereof is to improve the work efficiency of attaching a conductive member to a flange.

The drum conduction mechanism according to claim 1 is a drum conduction mechanism that electrically connects the inner wall of the drum and the external contact portion, and a shaft that is electrically connected to the external contact portion, and the shaft penetrates. A flange that is inserted into an end of the drum; and an electrically conductive member that is attached to the flange, electrically connects the inner wall of the drum and the shaft, and has elasticity. In the state in which the groove is formed and the shaft penetrates the conductive member, the gap between the tip portions that are arranged to sandwich the shaft and abut against the shaft is not formed in the shaft. smaller than the outer diameter, enters the tip said grooves, and said to face said tip in a direction opposite to the side through which the said shaft in order to penetrate the shaft to the gap the gap et bent so as to be oblique to the axis And a locking claw portion number of double tip portion is located radially outwardly of the outer shape of the flange, and, with respect to the axis of the shaft such that the tip is directed to the side to penetrate into the gap It is characterized in that it is formed by a contact portion that is bent so as to be inclined and the tip end portion contacts with the inner wall of the drum.

In the drum conduction mechanism according to the first aspect, a flange through which a shaft electrically connected to the external contact portion passes is inserted into the drum end portion. A conductive member having elasticity is attached to the flange. In the conductive member, the distal end portion of the locking claw portion enters the groove on the peripheral surface of the shaft and comes into contact therewith to be electrically connected to the shaft, and the contact portion is electrically connected to the inner wall of the drum. The shaft is electrically connected to the external contact portion. Therefore, the inner wall of the drum is electrically connected to the external contact portion via the conductive member and the shaft.

Now, when the conductive member is passed through the shaft passing through the flange, the tip of the locking claw enters the groove and comes into contact therewith. Therefore, the conductive member is fixed to the flange only by passing the conductive member through the shaft. Therefore, for example, it is not necessary to separately fix the conductive member and the flange with a screw or the like, so that work efficiency is good. Moreover, since the number of parts is small, the cost is low.

The drum conduction mechanism according to claim 2, wherein the drum conduction mechanism electrically connects the inner wall of the drum and the external contact portion, and a shaft electrically connected to the external contact portion and the shaft penetrates. A flange that is inserted into an end of the drum; and an electrically conductive member that is attached to the flange, electrically connects the inner wall of the drum and the shaft, and has elasticity. , the groove is formed, the conductive member includes a substrate portion in contact with the abutment surface of the flange, the central portion of the substrate portion is formed by being cut-split, the shaft penetrating the central portion In the state in which the substrate portion is in contact with the contact surface of the flange, the gap between the tip portions arranged with the shaft in contact with the shaft is larger than the outer diameter of the shaft in which the groove is not formed. small, the tip enters into the groove, One was found bent so as to be oblique to the said shaft in order to penetrate the shaft to the central portion as the side to penetrate the central portion toward said tip portion in a direction opposite to the side shaft and multiple engaging claw portion, projecting radially with respect to said axis from said substrate portion, the tip portion is located radially outwardly of the outer shape of the flange, and, passing the said shaft in said central portion bent so as to be slanted against the shaft so as to face the said tip side, it is characterized in that the tip is radiating portion and, in structure in contact with the inner wall of the drum.

In the drum conduction mechanism according to the second aspect, a flange through which a shaft electrically connected to the external contact portion passes is inserted into the end portion of the drum. A conductive member having elasticity is attached to the flange. In the conductive member, the distal end portion of the locking claw portion enters and abuts the groove on the peripheral surface of the shaft and is electrically connected to the shaft, and the radiating portion is electrically connected to the inner wall of the drum. The shaft is electrically connected to the external contact portion. Therefore, the inner wall of the drum is electrically connected to the external contact portion via the conductive member and the shaft.

Now, when the penetrating the central portion of the substrate portion of the conductive member in the axial extending through the flange, the distal end portion of the engaging claw portion which is cut-split enters the groove abuts the substrate section is the contact surface of the flange Abut.

  Therefore, the conductive member is fixed to the flange only by passing the conductive member through the shaft. Therefore, for example, it is not necessary to separately fix the conductive member and the flange with a screw or the like, so that work efficiency is good. Moreover, since the number of parts is small, the cost is low.

An image forming apparatus according to a third aspect includes the drum conduction mechanism according to the first or second aspect , wherein the drum is a photosensitive drum on which a latent image is formed, and the external contact portion is It is a ground contact portion connected to the ground of the image forming apparatus main body.

The image forming apparatus according to claim 3 is provided with a photosensitive drum. In order to form a latent image, it is necessary to ground the photosensitive drum. Therefore, the drum conduction mechanism according to claim 1 or 2 is provided, the shaft is electrically connected to a ground contact portion that connects to the ground of the image forming apparatus main body, and the photosensitive drum is grounded.

  As described above, according to the present invention, the conductive member is fixed to the flange only by passing the conductive member through the shaft. Therefore, for example, it is not necessary to separately fix the conductive member and the flange with a screw or the like, so that work efficiency is good.

  Hereinafter, as an example of an image forming apparatus to which a drum conduction mechanism according to the present invention is applied, a color printer to which a known electrophotographic process is applied will be described with reference to the drawings. The image forming apparatus to which the present invention is applied is not limited to a color printer described below, and may be a monochrome printer. Further, it may be an image forming apparatus such as a copying machine, a facsimile machine, or a multifunction machine.

  A first embodiment of the present invention will be described with reference to the drawings. In the following description, detailed descriptions of those not directly related to the essence of the present invention are omitted.

  FIG. 1 shows an outline of a color printer 10 to which a drum conduction mechanism 100 (see FIG. 3) according to the first embodiment is applied. The color printer 10 includes a color printer main body 12, and an open / close cover 16 that is rotatable about a rotation fulcrum 14 is provided on the upper portion of the color printer main body 12. In addition, a paper feeding unit 18 is disposed below the color printer main body 12.

  The paper supply unit 18 includes a paper supply unit main body 20 and a paper supply cassette 22 in which the recording paper P is stored. A feed roll 24 that feeds recording paper P from the paper feed cassette 22 and a retard roll 26 that scoops the supplied recording paper P one by one are arranged in the upper part near the rear end of the paper feed cassette 22.

  The conveyance path 28 is a path for the recording paper P from the feed roll 24 to the discharge port 30. The conveyance path 28 is in the vicinity of the back side (right side in FIG. 1) of the color printer main body 12 and is formed substantially vertically from the paper feeding unit 18 to the fixing device 90. A secondary transfer roll 80 and a secondary transfer backup roll 72 are arranged on the upstream side of the fixing device 90 in the conveyance path 28, and a resist roll 32 is arranged on the upstream side of the secondary transfer roll 80 and the secondary transfer backup roll 72. Has been. In addition, a discharge roll 34 is disposed in the vicinity of the discharge port 30 of the conveyance path 28.

  Accordingly, the recording paper P sent out from the paper feeding cassette 22 of the paper feeding unit 18 by the feed roll 24 is turned by the retard roll 26 and only the uppermost recording paper P is guided to the transport path 28, and is fed by the registration roll 32. At this time, the toner image is transferred between the secondary transfer roll 80 and the intermediate transfer belt 64 (secondary transfer backup roll 72) at a timing, and the transferred toner image is transferred by the fixing device 90. The toner is fixed and discharged from a discharge port 30 to a discharge portion 36 provided on the upper part of the opening / closing cover 16 by a discharge roll 34. The discharge portion 36 has a low discharge port portion and is inclined so as to gradually increase toward the front direction (left direction in FIG. 1).

  In the color printer main body 12, a photoconductive drum 50 is formed on the surface of a metallic drum on which a photoconductive film (a material whose electric resistance decreases when exposed to light) is rotated. Is provided.

  In addition, a rotary developing device 38 is arranged at a substantially central portion, and a control unit 39 for controlling each part of the color printer 10 is arranged on the front side (left side in FIG. 1) of the rotary developing device 38.

  The rotary developing device 38 includes developing units 42a to 42d that respectively form toner images of four colors of yellow, yellow, magenta, cyan, and black in the developing unit main body 40. It rotates counterclockwise (counterclockwise in FIG. 1) about the rotary developing device center 44. Each of the developing units 42a to 42d has developing rolls 46a to 46d, and is pressed in the normal direction of the developing unit main body 40 by elastic bodies 48a to 48d such as coil springs.

  The photosensitive drum 50 is disposed in contact with the rotary developing device 38. The developing rolls 46 a to 46 d are not in contact with the photosensitive drum 50, and a part of the outer periphery thereof protrudes from the outer periphery of the developing device main body 40 in the radial direction by about 2 mm. Further, a tracking roll (not shown) having a diameter slightly larger than the diameter of the developing rolls 46a to 46d is provided at both ends of each of the developing rolls 46a to 46d so as to rotate coaxially with the developing rolls 46a to 46d. Yes. In other words, the developing devices 42 a to 42 d are arranged on the outer periphery of the developing device main body 40 at intervals of 90 ° with the rotary developing device center 44 as the center, and the tracking rolls of the developing rollers 46 a to 46 d are disposed at both ends of the photosensitive drum 50. The latent image on the photosensitive drum 50 is developed with toner of each color while abutting against a provided flange (not shown) and forming a predetermined gap between the developing rolls 46a to 46d and the photosensitive drum 50. To do.

  A charging roll 52 is provided below the photosensitive drum 50, and a charging bias is applied to the charging roll 52 to uniformly charge the photosensitive drum 50. Further, a photosensitive drum cleaner 54 is provided so as to hang from the rotation support shaft 49 of the photosensitive drum 50, and the photosensitive drum 50 and the photosensitive drum cleaner 54 are integrated. The photoreceptor drum cleaner 54 includes a cleaning blade 56 that scrapes waste toner remaining on the photoreceptor drum 50 after primary transfer, and a toner collection case 58 that collects waste toner scraped by the cleaning blade 56.

  Note that a rib or the like is formed on the back side (right side in FIG. 1) of the toner recovery case 58, and the recording paper P is curved to form a part of the transport path 28.

  On the lower back side of the rotary developing device 38, an exposure device 60 for writing a latent image on the photosensitive drum 50 charged by the charging roll 52 with a light beam such as a laser beam is disposed. Further, the toner image visualized by the rotary developing device 38 is primarily transferred above the rotary developing device 38 at the primary transfer position, and the secondary transfer position (the nip between the secondary transfer roll 80 and the secondary transfer backup roll 72) is transferred. An intermediate transfer device 62 is provided.

  The intermediate transfer device 62 includes an intermediate transfer belt 64, a primary transfer roll 66, a wrap-in roll 68, a wrap-out roll 70, a secondary transfer backup roll 72, a scraper backup roll 74, a brush backup roll 76, and the like.

  The intermediate transfer belt 64 has elasticity and is stretched substantially flat so as to have a long side and a short side above the rotary developing device 38. The long sides on the upper and lower sides of the intermediate transfer belt 64 are stretched so as to be substantially parallel to the discharge portion 36 provided on the upper portion of the color printer main body 12.

  The intermediate transfer belt 64 is positioned between a wrap-in roll 68 disposed upstream of the primary transfer roll 66 below the long side of the intermediate transfer belt 64 and a wrap-out roll 70 disposed downstream of the primary transfer roll 66. Thus, the photosensitive drum 50 has a primary transfer portion (photosensitive drum wrap region) that contacts the photosensitive drum 50 in a wrap shape, is wound around the photosensitive drum 50 by a predetermined range, and is driven by the rotation of the photosensitive drum 50. As described above, the intermediate transfer belt 64 primarily transfers the toner image on the photosensitive drum 50 by the primary transfer roll 66 in the order of yellow, magenta, cyan, and black, and the primary transferred toner image is secondary-transferred. It is conveyed toward the transfer roll 80. Note that the wrap-in roll 68 and the wrap-out roll 70 are separated from the photosensitive drum 50.

  As described above, the intermediate transfer belt 64 is stretched by the five rolls of the wrap-in roll 68, the wrap-out roll 70, the secondary transfer backup roll 72, the scraper backup roll 74, and the brush backup roll 76, and the primary transfer roll 66, the toner image on the photosensitive drum 50 is transferred.

  Further, a flat portion (short side) is formed on the back side (right side surface in FIG. 1) of the intermediate transfer belt 64 by a wrap-out roll 70 and a secondary transfer backup roll 72, and this flat portion is the secondary transfer portion. It faces the conveyance path 28.

  In the secondary transfer portion, the wrap-out roll 70 is disposed so that the intermediate transfer belt 64 and the conveyance path 28 are at an angle of about 12 °.

  A scraper backup roll 74 assists the scraper 84 to scrape waste toner remaining on the intermediate transfer belt 64 after the secondary transfer, and a brush backup roll 76 removes waste toner remaining on the intermediate transfer belt 64 after the secondary transfer. Helps the brush roll 86 to scrape.

  A reflective photosensor 78 is provided above the long side of the intermediate transfer belt 64 by being fixed to the back surface (inside) of the open / close cover 16. The reflective photosensor 78 reads a toner patch formed on the intermediate transfer belt 64, detects the position of the intermediate transfer belt 64 in the rotational direction, and detects the density of the toner image.

  A secondary transfer roll 80 is opposed to the secondary transfer backup roll 72 of the intermediate transfer device 62 with the conveyance path 28 interposed therebetween. That is, the secondary transfer position in the secondary transfer portion is between the secondary transfer roll 80 and the secondary transfer backup roll 72, and the secondary transfer roll 80 is intermediate with the assistance of the secondary transfer backup roll 72. The toner image primarily transferred to the transfer belt 64 is secondarily transferred to the recording paper P at the secondary transfer position. Here, the secondary transfer roll 80 is rotated while the intermediate transfer belt 64 rotates three times, that is, while the toner images of three colors of yellow, magenta, and cyan are primarily transferred and conveyed on the intermediate transfer belt. It is separated from the intermediate transfer belt 64, and comes into contact with the intermediate transfer belt 64 when a black toner image is transferred.

  In addition, a predetermined potential difference is generated between the secondary transfer roll 80 and the secondary transfer backup roll 72, and when the secondary transfer roll 80 is set to a high voltage, the secondary transfer backup roll 72 is connected to the ground (GND).

  An intermediate transfer belt cleaner 82 is provided at the end of the intermediate transfer belt 64 on the side opposite to the photosensitive drum 50. The intermediate transfer belt cleaner 82 includes a scraper 84, a brush roll 86, a toner collection case 88 and a rotation support shaft 89, and swings about the rotation support shaft 89. The scraper 84 scrapes off and cleans waste toner remaining on the intermediate transfer belt 64 after the secondary transfer. The brush roll 86 further scrapes off the waste toner remaining after cleaning by the scraper 84. The toner collecting case 88 collects the waste toner cleaned by the scraper 84 and the brush roll 86. The scraper 84 is made of a thin stainless steel plate, and a voltage having a polarity opposite to that of the toner is applied.

  The brush roll 86 is made of a brush such as acrylic that has been subjected to a conductive treatment. While the intermediate transfer belt 64 conveys the toner image, the scraper 84 and the brush roll 86 are separated from the intermediate transfer belt 64 and come into contact with the intermediate transfer belt 64 at a predetermined timing. Has been.

  A fixing device 90 is disposed above the secondary transfer position. The fixing device 90 includes a heating roll 92 and a pressure roll 94, and fixes the toner image secondarily transferred to the recording paper P by the secondary transfer roll 80 and the secondary transfer backup roll 72 to the recording paper P. It is conveyed toward the discharge roll 34. The discharge roll 34 discharges the recording paper P from the discharge port 30 to a discharge unit 36 provided at the upper part of the opening / closing cover 16.

  Further, the intermediate transfer device 62, the photosensitive drum 50, the charging roll 52, the photosensitive drum cleaner 54, and the intermediate transfer belt cleaner 82 are integrated to form an image forming unit 96.

  As shown in FIG. 2, the image forming unit 96 is detachable from the color printer main body 12, and is attached to the color printer main body 12 by opening the opening / closing cover 16. Therefore, since the respective components of the image forming unit 96 can be exchanged at once, maintenance is easy.

  The photosensitive drum 50 is uniformly charged to a predetermined potential by the charging roll 52 while rotating the photosensitive drum 50, and exposure is performed according to image information. Since the photoconductive thin film is formed on the surface of the photosensitive drum 50, the resistance of the exposed portion is lowered, charging of the exposed portion is canceled, and a latent image is formed.

  Thus, in order to cancel the charging of the exposed portion of the photosensitive drum 50 and form a latent image, the photosensitive drum 50 needs to be grounded. Therefore, in the color printer 10, the photosensitive drum 50 is grounded by the drum conduction mechanism 100 described in detail below.

  As shown in FIG. 3, a flange 102 through which a rotation support shaft 49 passes is press-fitted into an end portion of the photosensitive drum 50 and fixed with an adhesive (not shown). A contact member 150 made of a sheet metal having a spring property is attached to the flange 102. The locking claw 154 of the contact member 150 is in contact with the rotation support shaft 49, and the radiating portion 156 of the contact member 150 is in contact with the inner wall 50 </ b> A of the photosensitive drum 50. In other words, the inner wall 50 </ b> A of the photosensitive drum 50 is electrically connected to the rotation support shaft 49 through the contact member 150.

  When the image forming unit 96 is mounted on the color printer main body 12, the rotation support shaft 49 comes into contact with the earth metal fitting 99 of the color printer main body 12. (See FIGS. 1 and 2). The ground metal fitting 99 is connected to the ground of the color printer main body 12. Therefore, the photosensitive drum 50 is grounded via the contact member 150, the rotation support shaft 49, and the ground metal fitting 99.

  Next, the flange 102 and the contact member 150 will be described in detail.

  As shown in FIGS. 4 and 5, the rotation support shaft 49 passes through the center of the flange 102. A groove 49A is formed on the circumferential surface of the rotation support shaft 49 on the side inserted into the end of the photosensitive drum 50 (see FIG. 3).

  The contact member 150 includes a substrate part 152.

  The substrate portion is attached to the contact surface 104 of the flange 102 at the end inserted into the photosensitive drum 50 (see FIG. 3). In addition, an engagement hole 158 is formed in the substrate portion 152, and a pin portion 106 that projects from the contact surface 104 of the flange 102 is inserted into the engagement hole 158.

  Further, the base portion 152 is cut at the center portion, and a triangular locking claw 154 is formed in which the tip portion 154A enters and contacts the groove 49A on the peripheral surface of the rotation support shaft 49. The locking claw 154 is bent outward. A gap (hereinafter, this gap is referred to as “hole A” (see FIG. 5)) is formed between the front end portions 154A of the locking claws 154. The hole A is smaller than the outer diameter of the groove 49A on the peripheral surface of the rotation support shaft 49 (which is necessarily smaller than the outer diameter of the rotation support shaft 49). Note that the height from the contact surface 104 of the flange 102 to the groove 49A on the peripheral surface of the rotary shaft 49 is slightly longer than the height from the substrate portion 152 to the tip portion 154A of the locking claw 154.

  Radiating portions 156 project radially from the substrate portion 152 with respect to the rotation support shaft 49. The tip 156A of the radiating portion 156 is pointed. Further, the radiating portion 156 is bent to the side opposite to the locking claw 154 described above. When the tip 156A of the radiating portion 156 is attached to the flange 102, it slightly protrudes outside the flange 102.

  Next, a method for attaching the contact member 150 to the flange 102 will be described.

  As shown in FIG. 6, the rotation support shaft 49 is inserted into the hole A formed by the tip 154 </ b> A of the locking claw 154. Although the hole A is smaller than the outer diameter of the rotation support shaft 49, the contact claw 154 is made of a metal plate having a spring property, so that the locking claw 154 is elastically deformed so that the tip portion 154A spreads outward. . Therefore, it can be inserted as shown in FIG. Furthermore, since the locking claw 154 is bent in the direction opposite to the insertion direction (upward in FIG. 6), the front end 154A of the locking claw 154 can be smoothly inserted without being caught by the rotation support shaft 49.

  As shown in FIG. 6C, when the board portion 152 comes into contact with the contact surface 104 of the flange 49, the height from the board portion 152 to the tip 154 </ b> A of the locking claw 154 increases from the contact surface 104 of the flange 102. Since the height up to the groove 49A on the peripheral surface of the rotation spindle 49 is slightly longer, the tip 154A of the locking claw 154 enters the groove 49A and comes into contact therewith. In addition, the pin portion 106 is inserted into the engagement hole 158 of the substrate portion 152.

  In this way, the tip 154A of the locking claw 154 enters the groove 49A and comes into contact therewith, so that it does not come off. Furthermore, since the latching claw 154 is bent in a direction (upward in FIG. 6) in which the substrate portion 152 is about to be pulled out, the latching claw 154 is supported and pinched, so that the latching claw 154 is configured to be more difficult to be pulled out. Further, since the engagement hole 158 is inserted into the pin portion 106, the contact member 150 does not rotate around the rotation support shaft 49.

  Further, since the locking claw 154 presses against the rotation support shaft 49 due to the spring property, it is firmly fixed and does not cause a contact failure between the engagement claw 154 and the rotation support shaft 49. . Furthermore, since the tip 154A of the locking claw 154 is sharp, the contact pressure is high. Therefore, contact failure is less likely to occur.

  Next, press-fitting of the flange 102 to which the contact member 150 is attached into the photosensitive drum 50 will be described.

  As shown in FIG. 7, the flange 102 to which the contact member 150 is attached is press-fitted into the photosensitive drum 50. Note that an adhesive (not shown) is applied to the peripheral surface 103 of the flange 102.

  When the tip 156 A of the radiating portion 156 is attached to the flange 102, it slightly protrudes outside the flange 102. That is, since it is larger than the inner diameter of the photosensitive drum 50 but is made of a metal plate having a spring property, the radiating portion 156 is elastically deformed at the front end portion 156A in the inner direction. Therefore, it can be inserted. Further, since the radiating portion 156 is bent in the direction opposite to the press-fitting direction (left side in FIG. 7), the distal end portion 156A of the radiating portion 156 can be smoothly inserted without being caught by the inner wall 50A of the photosensitive drum 50.

  As shown in FIG. 7B, after the press-fitting, the distal end portion 156A of the radiating portion 156 presses against the inner wall 50A of the photosensitive drum 50 due to the spring property, and therefore, between the radiating portion 156 and the photosensitive drum 50. There is no contact failure. Since the tip 156A of the radiating portion 156 is sharp, the contact pressure is high. Therefore, contact failure is less likely to occur.

  The flange 102 is firmly fixed to the photosensitive drum 50 with an adhesive.

  The tip 156A of the radiating portion 156 is press-fitted while being rubbed against the inner wall 50A of the photosensitive drum 50, so that a force is applied to the contact member 150. However, since the press-fitting direction is a direction in which the substrate portion 152 is pressed against the contact surface 104 of the flange 102, the contact claw 154 is not bent at the time of press-fitting, for example, so that contact failure does not occur.

  Next, the operation of this embodiment will be described.

  As described so far, the contact member 150 is fixed to the flange 102 only by passing the contact member 150 through the rotation support shaft 49. Therefore, for example, there is no need to separately fix the contact member 150 and the flange 102 with screws or the like, so that work efficiency is good. Moreover, since the number of parts is small, the cost is low.

  Next, a second embodiment of the present invention will be described with reference to the drawings. In addition, the same code | symbol is attached | subjected to the member demonstrated in 1st Embodiment, and the overlapping description is abbreviate | omitted.

  FIG. 8 shows a drum conduction mechanism 200 according to the second embodiment. A rib 250 protruding from the peripheral surface is formed on the rotation support shaft 249.

  Therefore, when the contact member 150 is inserted into the rotation support shaft 249, the front end portion 154A of the locking claw 154 gets over the rib 250 and comes into contact with the lower side of the rib 250 and is prevented from coming off. Since the rib 250 is formed with the slope portion 250A, when the tip portion 154A of the locking claw 154 gets over the rib 250, it can get over smoothly without being caught.

  Next, the operation of this embodiment will be described.

  As in the first embodiment, the contact member 150 is fixed to the flange 102 simply by passing the contact member 150 through the rotation support shaft 249, so that work efficiency is good.

  Next, a third embodiment of the present invention will be described with reference to the drawings. In addition, the same code | symbol is attached | subjected to the member demonstrated in 1st and 2nd embodiment, and the overlapping description is abbreviate | omitted.

  FIG. 9 shows a drum conduction mechanism 200 according to the second embodiment. A hole 350 into which the locking claw 154 is engaged is formed in the peripheral surface of the rotation support shaft 349. Therefore, when the contact member 150 is inserted into the rotation support shaft 349, the front end portion 154A of the locking claw 154 engages with the hole 350 and is prevented from coming off.

  Unlike the first and second embodiments, the pin portion 106 (see FIG. 5) is not formed on the contact surface 304 of the flange 302.

  Next, the operation of this embodiment will be described.

  As in the first and second embodiments, the contact member 150 is fixed to the flange 302 simply by passing the contact member 150 through the rotation support shaft 349, so that work efficiency is good.

  Further, even if the pin portion 106 is not formed, the contact member 150 does not rotate around the rotation support shaft 49 because the tip portion 154A of the locking claw 154 is engaged with the hole 350.

  The present invention is not limited to the above embodiment.

  For example, in the above-described embodiment, the present invention is applied to the photosensitive drum 50 on which a latent image is formed, but may be applied to other drums. Further, the present invention may be applied to apparatuses other than the image forming apparatus.

1 is a cross-sectional view schematically showing the inside of a color printer to which a drum conduction mechanism according to a first embodiment of the present invention is applied. FIG. 2 is a cross-sectional view schematically showing how an image forming unit is attached to and detached from a color printer main body. 1 is a partial cross-sectional perspective view showing a photosensitive drum to which a drum conduction mechanism according to a first embodiment of the present invention is applied. It is a perspective view which shows the conduction mechanism of the drum which concerns on the 1st Embodiment of this invention. It is a perspective view before attaching a contact member and a flange. It is explanatory drawing which shows a mode that a contact member is attached to a flange in order from (a) to (c). It is explanatory drawing which shows a mode that the flange in which the contact member was attached is press-fitted in a photoreceptor drum in order from (a) to (b). The conduction mechanism of the drum which concerns on the 2nd Embodiment of this invention is shown, (A) is a schematic diagram after an assembly | attachment, (B) is a perspective view before an assembly | attachment. The conduction mechanism of the drum which concerns on the 3rd Embodiment of this invention is shown, (A) is a schematic diagram after an assembly | attachment, (B) is a perspective view before an assembly | attachment.

Explanation of symbols

10 Color printer (image forming device)
49 Rotating spindle (shaft)
49A Groove 50 Photosensitive drum 99 Grounding bracket (Earth contact)
DESCRIPTION OF SYMBOLS 100 Drum conduction mechanism 102 Flange 104 Contact surface 150 Contact member (conductive member)
152 Substrate part 154 Locking claw (Locking claw part)
156 Radiation part (contact part)
200 Drum conduction mechanism 249 Rotating spindle (shaft)
250 ribs (convex)
300 Drum conduction mechanism 302 Flange 349 Rotating spindle (shaft)
350 holes

Claims (3)

In the drum conduction mechanism that electrically connects the inner wall of the drum and the external contact portion,
A shaft electrically connected to the external contact portion;
A flange that passes through the shaft and is inserted into an end of the drum;
An electrically conductive member attached to the flange, electrically connecting the inner wall of the drum and the shaft, and having elasticity;
With
A groove is formed on the peripheral surface of the shaft,
The conductive member is
In a state where the shaft penetrates the gap between the arranged across the axis of the axial abutting tip is smaller than the outer diameter of the shaft which is not the groove is formed, the tip enters into the groove and, the side through which the said shaft in order to penetrate the shaft to the gap the gap was found bent so as to be oblique to the axis so as to face said tip opposite direction double A number of locking claws,
A distal end portion is disposed radially outward from the outer shape of the flange, and the distal end portion is bent so as to be inclined with respect to the shaft so that the distal end portion is directed to the side penetrating the shaft through the gap. A contact portion that contacts the inner wall of the drum;
A drum conduction mechanism characterized by comprising: In the drum conduction mechanism that electrically connects the inner wall of the drum and the external contact portion,
A shaft electrically connected to the external contact portion;
A flange that passes through the shaft and is inserted into an end of the drum;
An electrically conductive member attached to the flange, electrically connecting the inner wall of the drum and the shaft, and having elasticity;
With
A groove is formed on the peripheral surface of the shaft,
The conductive member is
A substrate portion that contacts the contact surface of the flange;
In the state where the central portion of the substrate portion is cut and the shaft penetrates the central portion and the substrate portion is in contact with the contact surface of the flange, the shaft is disposed across the shaft. a gap between the tip that abuts is smaller than the outer diameter of the shaft which the groove is not formed, enters into the tip said grooves, and, the shaft in order to penetrate the shaft to the central portion and multiple engaging claw portion was found bent so as to be oblique to the axis so as to face said tip in a direction opposite to the side to penetrate to the central portion,
Projecting radially from the substrate portion with respect to the shaft, a tip portion is disposed radially outward from the outer shape of the flange, and the tip portion is directed to the side penetrating the shaft through the central portion. A radiating portion that is bent so as to be inclined with respect to the axis , and the tip portion contacts the inner wall of the drum;
A drum conduction mechanism characterized by comprising: The drum conduction mechanism according to claim 1 or 2,
The drum is a photosensitive drum on which a latent image is formed,
The image forming apparatus according to claim 1, wherein the external contact portion is a ground contact portion connected to the ground of the image forming apparatus main body.

Images