JP2016194583A - Image forming apparatus and drum unit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image forming apparatus and a drum unit that can smoothly discharge a toner.SOLUTION: An image forming apparatus 1 comprises a main body casing 2 and a drum unit 9. The drum unit 9 includes a photoconductor drum 11, a cleaning unit 30 that removes a toner remaining on the surface of the photoconductor drum 11, and a conveyance unit 31 that conveys the toner removed by the cleaning unit 30 to a waste toner storage unit 150. The conveyance unit 31 includes a first conveyance member 81, and a conveyance tube 80 that has a discharge port 107 for discharging the toner to the waste toner storage unit 150 and stores the first conveyance member 81. The conveyance tube 80 includes a first conveyance tube 95 that extends in the fore-and-aft direction and stores the first conveyance member 81, and a second conveyance tube 104 that is connected with the first conveyance tube 95 and extends in a direction intersecting with the direction in which the first conveyance tube 95 extends.SELECTED DRAWING: Figure 11

Description

  The present invention relates to an image forming apparatus employing an electrophotographic system, and a drum unit attached to the image forming apparatus.

  As an electrophotographic image forming apparatus, a so-called tandem type image forming apparatus having a photosensitive drum corresponding to each color of yellow, magenta, cyan, and black is known.

  As such an image forming apparatus, a plurality of process cartridges including a photoconductor cleaning device that supports a photosensitive drum and removes residual toner on the photosensitive drum, a frame that supports the plurality of process cartridges, and a plurality of process cartridges There has been proposed an image forming apparatus including a photoreceptor waste toner transport pipe for transporting waste toner from the photoreceptor cleaning device to a waste toner storage box (for example, see Patent Document 1 below).

JP 2010-8472 A

  However, in the image forming apparatus described in Patent Document 1 described above, the photoreceptor waste toner conveyance tube is supported by the frame so as to be connected to the photoreceptor cleaning apparatuses of a plurality of process cartridges.

  Therefore, the position of the photoreceptor waste toner transport tube is limited, and there is a problem that the toner cannot be discharged smoothly.

  SUMMARY OF THE INVENTION An object of the present invention is to provide an image forming apparatus and a drum unit that can smoothly discharge toner.

(1) An image forming apparatus of the present invention is a drum unit that is movable between a main body casing, an inner position in the main body casing, and an outer position outside the main body casing, and includes a photosensitive drum and a photosensitive drum. A drum unit comprising a cleaning unit configured to remove toner remaining on the surface, and a transport unit configured to transport toner removed by the cleaning unit, and transported by the transport unit A waste toner storage unit configured to store toner, and a transport unit configured to transport the toner removed by the cleaning unit along the moving direction of the drum unit; A transport pipe that houses the first transport member, and the toner transported by the first transport member is collected as waste toner. A transport pipe having a discharge port for discharging toward the unit, the transport pipe extending in the moving direction, and connected to the first transport pipe and the first transport pipe, A second transport pipe extending in a direction intersecting with the direction in which the pipe extends.

  According to such a configuration, the toner remaining on the surface of the photosensitive drum is removed by the cleaning unit and flows into the transport pipe of the transport unit.

  The transport pipe includes a first transport pipe that extends in the moving direction and accommodates the first transport member, and a second transport pipe that extends in a direction crossing the extending direction of the first transport pipe. The first transport pipe is transported along the moving direction, and the second transport pipe is transported along the direction intersecting the extending direction of the first transport pipe.

As a result, by disposing only the second transport pipe so as to extend in a direction intersecting with the direction in which the first transport pipe extends, the toner removed by the cleaning unit is transported to the discharge port by the second transport pipe, The toner can be smoothly discharged to the waste toner storage unit.
(2) Moreover, the 2nd conveyance pipe may be connected with the edge part of the 1st conveyance pipe in a moving direction.

According to such a configuration, since the second transport pipe is connected to the end of the first transport pipe in the movement direction, the toner can be collected at the end of the first transport pipe in the movement direction.
(3) Moreover, the conveyance pipe may be further provided with the 3rd conveyance pipe connected with the 2nd conveyance pipe and extending along the direction where a 1st conveyance pipe is extended.

According to such a configuration, since the transport pipe is connected to the second transport pipe and includes the third transport pipe extending along the direction in which the first transport pipe extends, the toner is more smoothly smoothed by the waste toner storage unit. Can be discharged.
(4) Moreover, the 3rd conveyance pipe | tube may have a discharge port.

According to such a configuration, the discharge port can be reliably arranged at a position away from the first transport pipe with a high degree of freedom. The unit can be discharged more smoothly.
(5) Further, a belt unit including a belt that contacts the photosensitive drum when the drum unit is located at the inward position, and at least a part of the first transport pipe is viewed in a direction in which the photosensitive drum and the belt overlap each other. The third transport tube does not have to overlap the belt unit when viewed in the direction in which the photosensitive drum and the belt overlap.

According to such a configuration, the toner can be discharged to the waste toner storage unit by the third transport pipe so as to avoid the belt unit.
(6) The belt unit may include a frame that supports the belt, and the frame may include a recess that houses the first transport pipe.

According to such a configuration, since the first transport pipe is accommodated in the recess of the frame that supports the belt, space saving can be achieved, and an increase in size of the image forming apparatus can be suppressed.
(7) A second transport member disposed in the third transport pipe, the second transport member configured to transport the toner transported by the first transport member along the movement direction. Also good.

  According to such a configuration, the toner in the third conveyance tube can be reliably conveyed along the movement direction by the second conveyance member.

As a result, the toner can be prevented from staying in the conveyance tube, and the toner can be reliably conveyed to the discharge port.
(8) Moreover, the 1st conveyance member and the 2nd conveyance member can be rotated, and the rotation axis of the 1st conveyance member may exist above the rotation axis of the 2nd conveyance member.

  According to such a configuration, since the rotational axis of the first transport member is above the rotational axis of the second transport member, the toner transported by the first transport member is moved to the second transport member by its own weight. Can be dropped.

As a result, after the toner is transported by the first transport member, the toner can be reliably transported toward the waste toner storage unit by the second transport member.
(9) The second transport member may be an auger screw.

According to such a configuration, since the second transport member is an auger screw, the toner can be transported more reliably in the third transport pipe.
(10) The first transport member may be an auger screw.

According to such a configuration, since the first conveying member is an auger screw, the toner can be more reliably conveyed in the first conveying tube.
(11) Moreover, the 2nd conveyance pipe may have the inclined surface which inclines below toward the direction away from a 1st conveyance pipe.

According to such a configuration, since the second conveyance tube has the inclined surface inclined downward, the toner is conveyed by its own weight from the first conveyance tube to the third conveyance tube along the inclined surface. Can do.
(12) The drum unit may include a positioning plate for positioning the photosensitive drum, and at least a part of the positioning plate may overlap with the discharge port when viewed from the vertical direction.

According to such a configuration, since the positioning plate can be disposed inward in the axial direction so as to overlap the discharge port when viewed from the top and bottom directions, the size of the drum unit can be reduced.
(13) The drum unit may include a positioning plate for positioning the photosensitive drum, and the positioning plate may be disposed inward of the discharge port in the axial direction of the photosensitive drum.

According to such a configuration, since the positioning plate is disposed inward of the discharge port in the axial direction, the drum unit can be reduced in size.
(14) Further, the discharge port may be disposed below the positioning plate in the vertical direction.

According to such a configuration, since the discharge port is disposed below the positioning plate, the toner can be discharged toward the waste toner storage unit so as to avoid the positioning plate.
(15) A drum unit of the present invention includes a first photosensitive drum, a second photosensitive drum, a first cleaning unit configured to remove toner remaining on the surface of the first photosensitive drum, and a second photosensitive drum. A second cleaning unit configured to remove toner remaining on the surface of the photosensitive drum, and configured to convey the toner removed by the first cleaning unit and the toner removed by the second cleaning unit; A transport unit, and the transport unit removes the toner removed by the first cleaning unit and the toner removed by the second cleaning unit along the alignment direction of the first photosensitive drum and the second photosensitive drum. A first conveying member configured to convey, and a conveying tube that houses the first conveying member, the first conveying member A transport pipe having a discharge port for discharging the toner transported by the material to the outside, the transport pipe extending in the alignment direction, and connected to the first transport pipe and accommodating the first transport member And a second transport pipe extending in a direction intersecting with the extending direction of the first transport pipe.

  According to such a configuration, the toner remaining on the surface of the first photosensitive drum is removed by the first cleaning unit and flows into the transport pipe of the transport unit.

  The toner remaining on the surface of the second photosensitive drum is removed by the second cleaning unit and flows into the transport pipe of the transport unit.

  The transport pipe includes a first transport pipe that extends in the alignment direction and accommodates the first transport member, and a second transport pipe that extends in a direction intersecting with the direction in which the first transport pipe extends. The toner removed from the photosensitive drum and the second photosensitive drum is collected in the first transport pipe, transported along the alignment direction in the first transport pipe, and intersects the extending direction of the first transport pipe in the second transport pipe. It is conveyed along the direction.

  As a result, the toner removed by the first cleaning unit and the toner removed by the second cleaning unit can be removed by arranging only the second transport pipe so as to extend in a direction intersecting the extending direction of the first transport pipe. Then, it can be transported to the discharge port by the second transport pipe and smoothly discharged to the waste toner storage unit.

  According to the image forming apparatus and the drum unit of the present invention, the toner can be discharged smoothly.

FIG. 1 is a central sectional view of an image forming apparatus as an embodiment of the present invention. FIG. 2 is a perspective view of the drum unit shown in FIG. 1 as viewed from the upper right. FIG. 3 is a perspective view of the belt unit shown in FIG. 1 as viewed from the upper right. FIG. 4A is a perspective view of the transport unit shown in FIG. 2 as viewed from the upper right. FIG. 4B shows a state where the first positioning plate is attached to the transport unit shown in FIG. 4A. FIG. 4C is a perspective view of the transport unit and the first positioning plate shown in FIG. 4B as viewed from the lower left. FIG. 5A is a perspective view of the transport unit shown in FIG. 4A as viewed from the lower right, and shows a state where the shutter is located at the closed position. FIG. 5B is a perspective view of the transport unit shown in FIG. 4A as viewed from the lower right, and shows a state where the shutter is located at the open position. 5A and 5B, the urging member is omitted for convenience. FIG. 6 is a front view of the drum unit and the belt unit shown in FIG. FIG. 7 is a cross-sectional view taken along the line AA of FIG. 8 is a cross-sectional view taken along line BB in FIG. In FIG. 8, members other than the photosensitive drum, the cleaning unit, and the second positioning plate are omitted. 9 is a cross-sectional view taken along the line CC of FIG. FIG. 10 is an explanatory diagram for explaining the toner conveyance direction in the drum unit shown in FIG. 2. 11A is a cross-sectional view taken along the line DD of FIG. 11B is a cross-sectional view taken along line EE in FIG.

1. Overall Configuration of Image Forming Apparatus As shown in FIG. 1, the image forming apparatus 1 is a horizontal type direct tandem color laser printer.

  The image forming apparatus 1 includes a main body casing 2 having an opening 21, a process unit 3, a scanner unit 4, a belt unit 5, and a fixing unit 6.

  The main casing 2 is formed in a substantially box shape. The main casing 2 has a front cover 22, a paper feed tray 7, and a paper discharge tray 8.

  The opening 21 is disposed at the front end of the main casing 2. The opening 21 communicates the inside and outside of the main casing 2 in the front-rear direction so as to allow passage of the process unit 3.

  The front cover 22 is disposed at the front end of the main casing 2. The front cover 22 has a substantially flat plate shape. The front cover 22 extends in the vertical direction, and is swingably supported on the front wall of the main body casing 2 with the lower end portion as a fulcrum. The front cover 22 is configured to open or close the opening 21.

  The paper feed tray 7 is disposed at the bottom of the main casing 2. The paper feed tray 7 is configured to accommodate the paper P.

  The paper discharge tray 8 is disposed on the upper wall of the main body casing 2. The paper discharge tray 8 is recessed downward from the upper surface of the main casing 2 so that the paper P is placed thereon.

  The process unit 3 is disposed in the center of the main casing 2. The process unit 3 is slidable in the front-rear direction through an opening 21 to an inward position located in the main casing 2 and an outer position located outside the main casing 2. The process unit 3 includes a drum unit 9 and a plurality (four) of developing cartridges 10.

  The drum unit 9 includes a plurality (four) of photosensitive drums 11 and a plurality (four) of scorotron chargers 12.

  The photosensitive drum 11 is rotatably supported at the lower end of the process unit 3. The four photosensitive drums 11 correspond to yellow, magenta, cyan, and black. The four photosensitive drums 11 are arranged in parallel in the order of yellow, magenta, cyan, and black from the front toward the rear. The photosensitive drum 11 has a substantially cylindrical shape extending in the left-right direction.

  The scorotron chargers 12 are arranged at intervals behind the corresponding photosensitive drums 11.

  The four developing cartridges 10 have the same configuration except for the color of the toner accommodated therein. The developing cartridge 10 is disposed above the corresponding photosensitive drum 11. The developing cartridge 10 includes a developing roller 13 and a supply roller 14.

  The developing roller 13 is rotatably supported at the lower end portion of the developing cartridge 10 so as to be exposed rearward. The developing roller 13 is in contact with the front upper end portion of the photosensitive drum 11.

  The supply roller 14 is disposed on the front upper side of the developing roller 13. The supply roller 14 is in contact with the front upper end portion of the developing roller 13.

  The scanner unit 4 is disposed at the upper end portion of the main body casing 2. As shown by a solid line in FIG. 1, the scanner unit 4 emits a laser beam toward the photosensitive drum 11 based on the image data to expose the photosensitive drum 11.

  The belt unit 5 is disposed below the process unit 3. The belt unit 5 includes a driving roller 15, a driven roller 16, a belt 17, and a plurality (four) of transfer rollers 18.

  The driving roller 15 is disposed at the rear end of the belt unit 5.

  The driven roller 16 is disposed at the front end portion of the belt unit 5 so as to be opposed to the driving roller 15 with a space therebetween.

  The belt 17 is wound around the driving roller 15 and the driven roller 16 so that the upper portion of the belt 17 comes into contact with all the photosensitive drums 11 when the drum unit 9 is located at the inward position. The belt 17 is rotated by the drive of the drive roller 15 and the driven of the driven roller 16 so that the upper part thereof moves from the front toward the rear.

  The transfer roller 18 is disposed below the corresponding photosensitive drum 11 with the upper portion of the belt 17 interposed therebetween.

  The fixing unit 6 is disposed behind the belt unit 5. The fixing unit 6 includes a heating roller 19 and a pressure roller 20 that contacts the heating roller 19.

  When the image forming apparatus 1 starts an image forming operation, the scorotron charger 12 uniformly charges the surface of the photosensitive drum 11. Thereafter, the scanner unit 4 exposes the surface of the photosensitive drum 11. Thereby, an electrostatic latent image based on the image data is formed on the surface of the photosensitive drum 11.

  The supply roller 14 supplies the toner in the developing cartridge 10 to the developing roller 13. At this time, the toner is frictionally charged positively between the developing roller 13 and the supply roller 14 and is carried on the developing roller 13.

  The developing roller 13 supplies the carried toner to the electrostatic latent image on the surface of the photosensitive drum 11. As a result, the toner image is carried on the surface of the photosensitive drum 11.

  The paper P is transported forward and upward from the paper feed tray 7 by the rotation of various rollers, and then U-turns rearward and upward, between the yellow photosensitive drum 11 and the belt 17 one by one at a predetermined timing. Paper is fed to Thereafter, the paper P is conveyed from the front to the rear by the belt 17. The toner image on the photosensitive drum 11 is transferred to the paper P when the paper P passes between the photosensitive drum 11 and the transfer roller 18.

Thereafter, the sheet P is heated and pressed when it passes between the heating roller 19 and the pressure roller 20. At this time, the toner image on the paper P is thermally fixed to the paper P. Thereafter, the paper P is discharged to the paper discharge tray 8.
2. Details of the Drum Unit As shown in FIGS. 2 and 7, the drum unit 9 has a substantially rectangular frame shape in plan view. The drum unit 9 includes a first positioning plate 28 and a second positioning plate 29 as an example of a positioning plate having a plurality of (four) holes 40 and a plurality (four) holes 41, and the four photosensitive drums 11 described above. A plurality of (four) cleaning units 30, a transport unit 31, a front plate 32, a rear plate 33, a first side plate 34, and a second side plate 35 having a plurality (four) holes 142. ing.
(1) First positioning plate and second positioning plate The first positioning plate 28 is disposed at the right end of the drum unit 9 as shown in FIG. As shown in FIG. 4B, the first positioning plate 28 has a flat plate shape that is substantially rectangular in a side view that is long in the front-rear direction. The first positioning plate 28 includes an inclined portion 42 and a refracting portion 43 having a notch 48.

  The four holes 40 are arranged at equal intervals in the front-rear direction. The hole 40 is disposed corresponding to the photosensitive drum 11. The hole 40 has a substantially circular shape in a side view.

  The four holes 41 are arranged at equal intervals in the front-rear direction. The holes 41 are arranged behind the corresponding holes 40. The hole 41 has a substantially rectangular shape in side view.

  The inclined portion 42 has a substantially flat plate shape that is substantially rectangular in a side view extending from the front end portion of the first positioning plate 28 toward the front upper side. The inclined portion 42 includes a bulging portion 45 having a hole 46.

  The bulging portion 45 has a substantially flat plate shape having a substantially triangular shape in a side view that bulges from the substantial center in the direction connecting the front upper portion and the rear lower portion of the inclined portion 42 toward the front lower portion.

  The hole 46 is disposed in a continuous portion between the bulging portion 45 and the inclined portion 42. The hole 46 has a substantially circular shape in side view.

  The refracting portion 43 has a substantially rectangular flat plate shape in a side view extending upward from the rear end portion of the first positioning plate 28.

  The notch 48 is disposed at the rear end portion of the refracting portion 43. The notch 48 is notched forward from the rear edge of the refracting portion 43. The notch 48 has a substantially V shape in side view with the rear end portion opened.

As shown in FIGS. 7 and 8, the second positioning plate 29 is disposed at the left end portion of the drum unit 9 with a space leftward from the first positioning plate 28. The second positioning plate 29 has substantially the same shape as the first positioning plate 28. The second positioning plate 29 does not include the refracting portion 43 in the bulging portion 45, while the first positioning plate 28 includes the bulging portion 45 in the inclined portion 42. Since the second positioning plate 29 is the same as the first positioning plate 28 except for the above-described configuration, other description is omitted.
(2) Photosensitive drum As shown in FIG. 7, the photosensitive drum 11 includes a drum body 50, a first flange 51, a second flange 52, and a drum coupling 53.

  The drum body 50 is disposed between the first positioning plate 28 and the second positioning plate 29. The drum main body 50 is a substantially cylindrical metal tube extending left and right, and has a photosensitive layer on the outer peripheral surface.

  The first flange 51 is fitted to the right end portion of the drum body 50 so as not to be relatively rotatable. The first flange 51 includes a large diameter part 51A and a small diameter part 51B.

  The large diameter portion 51 </ b> A is disposed at the left end portion of the first flange 51. The large-diameter portion 51A has a substantially cylindrical shape with the right end portion closed. The outer diameter of the large-diameter portion 51A is substantially the same as the inner diameter of the drum body 50. The large diameter portion 51 </ b> A is inserted into the drum body 50 at the right end of the drum body 50.

  The small diameter part 51B protrudes rightward from the right wall of the large diameter part 51A. The small diameter part 51B has a substantially cylindrical shape sharing a central axis with the large diameter part 51A. The outer diameter of the small diameter part 51B is smaller than the outer diameter of the large diameter part 51A. The small diameter portion 51 </ b> B is fitted in the corresponding hole 40 of the first positioning plate 28.

  Accordingly, the first positioning plate 28 positions the photosensitive drum 11 by supporting the first flange 51.

  The second flange 52 is fitted to the left end portion of the drum main body 50 so as not to be relatively rotatable. The second flange 52 includes a large diameter part 52A, a gear part 52C, and a small diameter part 52B.

  The large diameter portion 52 </ b> A is disposed at the right end portion of the second flange 52. The large diameter portion 52A has a substantially cylindrical shape. The outer diameter of the large diameter portion 52A is substantially the same as the inner diameter of the drum body 50. The large diameter portion 52 </ b> A is inserted into the drum main body 50 at the left end portion of the drum main body 50.

  The gear portion 52C is disposed adjacent to the left of the large diameter portion 52A. The gear portion 52C shares a central axis with the large diameter portion 52A and has a substantially disc shape having a thickness in the left-right direction. The gear portion 52C has gear teeth over the entire peripheral surface.

  The small diameter portion 52B protrudes leftward from the gear portion 52C. The small diameter part 52B has a substantially cylindrical shape sharing a central axis with the large diameter part 52A and the gear part 52C. The outer diameter of the small diameter part 52B is smaller than the outer diameters of the large diameter part 52A and the gear part 52C. The small diameter portion 52 </ b> B is fitted in the corresponding hole 40 of the second positioning plate 29.

  Thereby, the second positioning plate 29 positions the photosensitive drum 11 by supporting the second flange 52.

  The drum coupling 53 is disposed at the left end portion of the photosensitive drum 11. The drum coupling 53 includes a disc part 53A and a shaft part 53B.

  The disc portion 53 </ b> A is disposed on the left side of the second positioning plate 29. The disc portion 53A has a substantially disc shape having a thickness in the left-right direction. The diameter of the disc portion 53A is smaller than the large diameter portion 52A of the second flange 52 and larger than the small diameter portion 52B. The disc part 53A is configured to engage with a main body coupling 155 of the main body casing 2 to be described later in a relatively non-rotatable manner.

The shaft portion 53B protrudes rightward from the disc portion 53A. The shaft portion 53B has a substantially cylindrical shape sharing a central axis with the disc portion 53A. The outer diameter of the shaft portion 53B is substantially the same as the inner diameter of the small diameter portion 52B. The shaft portion 53B is fitted to the small diameter portion 52B of the second flange 52 so as not to be relatively rotatable.
(3) Cleaning Unit As shown in FIGS. 7 and 8, the cleaning unit 30 is disposed behind the corresponding photosensitive drum 11. The cleaning unit 30 is configured to remove toner adhered and remaining on the surface of the drum body 50 of the photosensitive drum 11. The cleaning unit 30 includes a frame 60, a cleaning member 61, a cleaning conveyance member 62, and a charge removal member 63.

  The frame 60 includes a main body portion 66, a first wall portion 67, and a second wall portion 68.

  The main body 66 is disposed at the rear end of the frame 60. The main body 66 has a substantially rectangular tube shape extending in the left-right direction and closed at both ends in the left-right direction. The main body portion 66 includes a blade support portion 70, a waste toner conveyance portion 71, a gear accommodation portion 72, and a charge removal member accommodation portion 73.

  As shown in FIG. 8, the blade support portion 70 is disposed at the upper end portion of the main body portion 66. The blade support part 70 has a substantially plate shape extending in the left-right direction.

  The waste toner conveyance unit 71 is disposed below the blade support unit 70. The waste toner conveying portion 71 has a substantially semi-cylindrical shape extending in the left-right direction, closed at the left end, and opened at the right end and the front end. The upper end portion of the waste toner conveying portion 71 is continuous with the lower end portion of the blade support portion 70.

  The gear accommodating portion 72 is disposed on the left side of the waste toner conveying portion 71 as shown in FIG. The gear accommodating portion 72 has a substantially semi-cylindrical shape extending in the left-right direction, closed at both left and right ends, and opened at the front end.

  As shown in FIG. 8, the neutralizing member accommodating portion 73 is disposed below the waste toner conveying portion 71. The static elimination member accommodating part 73 has the substantially square cylinder shape extended in the left-right direction, and the front-end part was open | released. The upper end portion of the charge removal member accommodating portion 73 is continuous with the lower end portion of the waste toner conveying portion 71.

  As shown in FIG. 7, the first wall portion 67 is disposed at the right end portion of the frame 60. The first wall portion 67 has a substantially flat plate shape extending forward from the right end portion of the main body portion 66. The first wall 67 is in contact with the inner surface of the first positioning plate 28.

  As shown in FIGS. 7 and 8, the second wall portion 68 is disposed at the left end portion of the frame 60. The second wall portion 68 has a substantially flat plate shape extending forward from the left end portion of the main body portion 66. The second wall portion 68 is in contact with the inner surface of the second positioning plate 29.

  As shown in FIGS. 8 and 10, the cleaning member 61 includes a support member 75 and a blade 76.

  The support member 75 is made of metal and has a substantially flat plate shape extending in the left-right direction. The support member 75 is fixed to the blade support portion 70 of the frame 60.

  The blade 76 is made of an elastic member such as rubber and has a substantially flat plate shape extending in the left-right direction. The upper end portion of the blade 76 is fixed to the support member 75. The lower end of the blade 76 faces the front of the waste toner transport unit 71 so as to cover the upper half of the waste toner transport unit 71. Further, the lower end portion of the blade 76 is in contact with the rear end portion of the drum main body 50 of the photosensitive drum 11 while being curved backward.

  The cleaning conveyance member 62 is disposed in the waste toner conveyance portion 71 as shown in FIGS. The cleaning conveyance member 62 is a right-handed auger screw extending in the left-right direction. The left end portion of the cleaning conveyance member 62 is supported on the wall between the gear housing portion 72 and the waste toner conveyance portion 71 so as to be relatively rotatable. Further, the left end portion of the cleaning conveyance member 62 is disposed in the gear accommodation portion 72 so as to penetrate between the gear accommodation portion 72 and the waste toner conveyance portion 71. As shown in FIGS. 7 and 10, the cleaning conveyance member 62 includes a gear 78.

  The gear 78 is supported by the left end portion of the cleaning conveyance member 62 so as not to rotate relative to the gear housing 72. The gear 78 has a substantially cylindrical shape extending in the left-right direction, and has gear teeth over the entire peripheral surface thereof. As shown in FIG. 7, the gear 78 is disposed behind the second flange 52 of the photosensitive drum 11. The gear 78 meshes with the gear portion 52 </ b> C of the second flange 52 of the photosensitive drum 11.

As shown in FIG. 8, the static elimination member 63 is fixed in the static elimination member accommodation portion 73. The static eliminating member 63 has a semi-cylindrical shape extending in the left-right direction. The front surface of the static elimination member 63 has a substantially arc shape in side view so that the center in the vertical direction bulges forward. The neutralization member 63 exposes the toner on the surface of the drum main body 50 of the photosensitive drum 11 after the toner image is transferred to the paper P before being removed by the corresponding cleaning member 61, and the drum main body 50 of the corresponding photosensitive drum 11. Reduce the surface charge.
(4) Transport Unit The transport unit 31 is arranged at the lower right end of the drum unit 9 as shown in FIGS. The transport unit 31 is configured to transport the toner removed from the surface of the photosensitive drum 11 by the cleaning unit 30 to a waste toner storage unit 150 described later. 4A and 9, the transport unit 31 includes a transport pipe 80, a first transport member 81, a second transport member 82, a first gear 84, a second gear 85, and a gear cover 86. The shutter unit 88 is provided.

  The conveyance tube 80 extends in the front-rear direction, that is, the moving direction of the drum unit 9. The conveyance pipe 80 includes a first conveyance unit 91, a second conveyance unit 92, and a closing unit 93 having a hole 111 through which the first conveyance member 81 is inserted and a hole 112 through which the second conveyance member 82 is inserted. ing.

  The first transport unit 91 includes a first transport pipe 95 and a plurality (four) of connection units 96.

  The first transport pipe 95 has a substantially cylindrical shape extending in the front-rear direction and closed at the rear end. As shown in FIG. 11B, the first transport pipe 95 is disposed adjacent to the left of the lower end portion of the first positioning plate 28.

  As shown in FIGS. 4A and 4C, the four connection portions 96 are disposed above the first transport pipe 95 and spaced from each other in the front-rear direction. The connection part 96 includes an insertion part 97, a communication part 98, and a fixing part 99 having a fixing hole 101.

  The insertion portion 97 is disposed at the front upper end portion of the connection portion 96. The insertion portion 97 has a substantially cylindrical shape extending in the left-right direction, having a left end opened and a right end closed. As shown in FIG. 7, the insertion portion 97 is connected to the right end portion of the frame 60 of the cleaning unit 30 via a seal member (not shown). The right end portion of the cleaning conveyance member 62 of the cleaning unit 30 is inserted into the insertion portion 97.

  As shown in FIGS. 4C and 9, the communication part 98 is disposed behind the static elimination member 63 and below the insertion part 97. The communication part 98 has a substantially rectangular tube shape extending in the vertical direction. The rear upper end portion of the communication portion 98 is inclined forward as it goes upward. The front upper end portion of the communication portion 98 communicates with the rear lower end portion of the insertion portion 97. The lower end portion of the communication portion 98 communicates with the upper end portion of the first transfer pipe 95.

  As shown in FIGS. 4A and 4C, the fixing portion 99 is disposed at the rear upper end portion of the connection portion 96. The fixing part 99 has a substantially rectangular flat plate shape in side view extending upward from the right end part of the communication part 98.

  The fixing hole 101 is disposed at the center of the fixing part 99. The fixing hole 101 penetrates the fixing portion 99 in the left-right direction. The fixing hole 101 has a substantially circular shape in side view.

  Although not shown, the fixing portion 99 is sandwiched between the right end portion of the frame 60 of the cleaning unit 30 and the first positioning plate 28 and screwed so that the screw member is inserted into the fixing hole 101. Accordingly, the cleaning unit 30 is fixed to the frame 60 and the first positioning plate 28.

  As shown in FIG. 9 and FIG. 11A, the second transport unit 92 includes a connecting tube 103, a second transport tube 104, a third transport tube 105 having a discharge port 107, and an engaging unit 106.

  The connecting tube 103 is disposed at the upper left end of the second transport unit 92. The connecting pipe 103 has a substantially cylindrical shape that extends in the front-rear direction and shares a central axis with the first transport pipe 95. The connecting pipe 103 is fitted in the front end portion of the first transport pipe 95.

  As shown in FIG. 4C and FIG. 11A, the second transport pipe 104 is disposed on the lower right side of the front end portion of the connection pipe 103. The second transport pipe 104 has a substantially rectangular tube shape that extends in a direction connecting the upper left and the lower right, and the front is opened. That is, the second transport pipe 104 extends in a direction intersecting with the direction in which the first transport pipe 95 extends. The upper left end portion of the second transport pipe 104 communicates with the lower right end portion at the front end portion of the connecting pipe 103. That is, the second transfer pipe 104 is connected to the front end portion of the first transfer pipe 95 via the connecting pipe 103. As shown in FIG. 11A, the lower left surface inside the second transfer tube 104 is configured as an inclined surface 104 </ b> A that is inclined downward as the distance from the first transfer tube 95 increases.

  As shown in FIGS. 5A and 9, the third transport pipe 105 has a substantially cylindrical shape that extends rearward from the lower right end portion of the second transport pipe 104 and is closed at the rear end portion. The third transport pipe 105 extends along the same direction as the direction in which the first transport pipe 95 extends. The third transfer pipe 105 is connected by the second transfer pipe 104 so that the first transfer pipe 95 communicates with the inside and the outside thereof. In other words, the second transport pipe 104 connects the first transport pipe 95 and the third transport pipe 105. That is, in the transport pipe 80, the second transport pipe 104 connects the most downstream part in the first direction in the first transport pipe 95 and the most upstream part in the second direction in the third transport pipe 105. The 3rd conveyance pipe 105 is arrange | positioned under the 1st positioning board 28, as shown to FIG. 11B. As shown in FIG. 9, the rear end portion of the third transport pipe 105 is positioned in front of the center axis of the frontmost photosensitive drum 11 and in front of the frontmost connection portion 96.

  The discharge port 107 is disposed at the rear end portion of the third transport pipe 105. The discharge port 107 penetrates the lower peripheral wall of the third transport pipe 105 in the vertical direction. The discharge port 107 has a substantially rectangular shape in bottom view. The discharge port 107 is located in front of the central axis of the foremost photosensitive drum 11. As shown in FIG. 11B, the discharge port 107 overlaps the first positioning plate 28 in the vertical direction. In other words, the discharge port 107 is located outward from the first axis A1 of the first transport member 81 in the left-right direction.

  As shown in FIGS. 4A and 11A, the engaging portion 106 has a substantially flat plate shape that is substantially rectangular in a side view and protrudes upward from the upper portion of the connecting pipe 103. The engaging portion 106 is disposed on the left side of the bulging portion 45 of the first positioning plate 28. The engaging portion 106 includes a boss 108.

  The boss 108 has a substantially cylindrical shape that protrudes rightward from the right surface of the engaging portion 106. The boss 108 is fitted in the hole 46 of the first positioning plate 28.

  As shown in FIGS. 4C and 9, the closing portion 93 is disposed at the front end portion of the transport pipe 80. The closing portion 93 has a substantially flat plate shape that is substantially rectangular in front view and extends in a direction connecting the upper left and the lower right. The closing portion 93 includes an insertion portion 113, a support portion 115 that supports the first gear 84, and a support portion 116 that supports the second gear 85.

  The hole 111 is disposed substantially at the center in the upper left portion of the closing portion 93. The hole 111 has a circular shape when viewed from the front. The hole 111 shares the central axis with the first transport member 81.

  The hole 112 is disposed substantially at the center in the lower right portion of the closing portion 93. The hole 112 has a substantially circular shape when viewed from the front. The hole 112 shares the center axis with the second transport member 82.

  As shown in FIG. 9, the insertion portion 113 extends rearward from the rear surface of the closing portion 93. As shown in FIG. 11A, the insertion portion 113 has a substantially elliptical cylindrical shape in cross section. The insertion part 113 is fitted in the front end part of the second transport part 92.

  As shown in FIG. 9, the support portion 115 has a substantially cylindrical shape extending forward from the front surface of the closing portion 93 slightly spaced from the periphery of the hole 111. The support part 115 shares the center axis with the hole 111.

  The support portion 116 has a substantially cylindrical shape extending forward from the front surface of the closing portion 93 slightly spaced from the periphery of the hole 112. The support part 116 shares the central axis with the hole 112.

  The first transport member 81 is disposed in the first transport pipe 95 of the first transport unit 91. As shown in FIGS. 9 and 10, the first conveying member 81 is a right-handed auger screw that can rotate about a first axis A1 extending in the front-rear direction. The rear end portion of the first transport member 81 is rotatably supported by the rear wall of the first transport pipe 95. The front end portion of the first conveying member 81 passes through the hole 111 of the closing portion 93 and extends further forward than the front end portion of the supporting portion 115 of the closing portion 93.

  As illustrated in FIG. 9, the second transport member 82 is disposed in the third transport pipe 105 of the second transport unit 92. As shown in FIGS. 9 and 10, the second transport member 82 is a right-handed auger screw that can rotate about a second axis A <b> 2 that extends in the front-rear direction. The second transport member 82 is disposed on the lower right side of the first transport member 81. In other words, the first axis A <b> 1 of the first transport member 81 is above the second axis A <b> 2 of the second transport member 82. The second transport member 82 is parallel to the first transport member 81. The front-rear direction dimension of the second transport member 82 is shorter than the front-rear direction dimension of the first transport member 81. The rear end portion of the second transport member 82 is rotatably supported by the rear wall of the third transport pipe 105. The front end portion of the second conveying member 82 passes through the hole 112 of the closing portion 93 and extends further forward than the front end portion of the supporting portion 116 of the closing portion 93.

  The first gear 84 is supported by the front end portion of the first conveying member 81 so as not to rotate relative to the front of the closing portion 93. The first gear 84 has a substantially cylindrical shape extending in the front-rear direction, and has gear teeth over the entire peripheral surface thereof. That is, the first gear 84 is fixed to the first transport member 81 and can be rotated together with the first transport member 81. The first gear 84 includes a first boss 121 as shown in FIG.

  The first boss 121 protrudes rearward from the rear surface of the first gear 84 and has a substantially cylindrical shape that shares the central axis with the first gear 84. The first boss 121 is rotatably fitted to the support portion 115 of the closing portion 93.

  As shown in FIGS. 9 and 10, the second gear 85 is supported on the front end portion of the second transport member 82 in a non-rotatable manner in front of the closing portion 93. The second gear 85 has a substantially cylindrical shape extending in the front-rear direction, and has gear teeth over the entire peripheral surface thereof. That is, the second gear 85 is fixed to the second transport member 82 and can be rotated together with the second transport member 82. The second gear 85 meshes with the lower right end portion of the first gear 84. Moreover, the 2nd gear 85 is provided with the 2nd boss | hub 122, as shown in FIG.

  The second boss 122 protrudes rearward from the rear surface of the second gear 85 and has a substantially cylindrical shape that shares the central axis with the second gear 85. The second boss 122 is rotatably fitted to the support portion 116 of the closing portion 93.

  The gear cover 86 is disposed at the front end portion of the transport unit 31 as shown in FIGS. 4C and 9. The gear cover 86 has a substantially box shape with the rear and lower left open. The gear cover 86 covers the first gear 84 and the second gear 85 from the front so that the lower left end of the first gear 84 and the lower left end of the second gear 85 are exposed. The gear cover 86 includes a support portion 124 that supports the first transport member 81 and a support portion 125 that supports the second transport member 82.

  The support portion 124 has a substantially cylindrical shape that protrudes rearward from the rear surface of the front wall of the gear cover 86. The support part 124 shares the central axis with the first transport member 81. The support portion 124 receives the front end portion of the first transport member 81 so as to be relatively rotatable.

  The support part 125 has a substantially cylindrical shape that protrudes rearward from the rear surface of the gear cover 86 at the lower right of the support part 124. The support part 125 shares the center axis with the second transport member 82. The support portion 125 receives the front end portion of the second transport member 82 so as to be relatively rotatable.

  As shown in FIG. 2, the shutter unit 88 is assembled to the third transport pipe 105 of the second transport unit 92. The shutter unit 88 includes a shutter 130 and a biasing member 131.

  The shutter 130 is configured to be rotatable between a closed position shown in FIG. 5A where the discharge port 107 of the third transport pipe 105 is closed and an open position shown in FIG. 5B where the discharge port 107 of the third transport pipe 105 is opened. ing. In the following description of the shutter 130, the shutter 130 will be described based on the state in the closed position shown in FIG. 5A.

  As shown in FIGS. 4A and 5A, the shutter 130 includes a shutter main body 133 having a communication port 134 and a protrusion 135.

  The shutter body 133 has a substantially cylindrical shape extending in the front-rear direction. The shutter main body 133 receives the third transport pipe 105 therein.

  The communication port 134 penetrates the right peripheral wall of the shutter main body 133 in the left-right direction. The communication port 134 has a substantially rectangular shape in side view. The communication port 134 is located at substantially the same position as the discharge port 107 of the third transport pipe 105 in the front-rear direction.

  The protrusion 135 has a substantially flat plate shape that is substantially L-shaped in a side view and protrudes rightward from the right front end of the shutter body 133. The front end portion of the protrusion 135 is positioned in front of the front end portion of the shutter main body 133. When the shutter 130 is located at the open position shown in FIG. 5B, the protrusion 135 is located at the first position extending downward from the shutter body 133, and when the shutter 130 is located at the closed position shown in FIG. 5A. , Located at a second position extending rightward from the shutter body 133.

As shown in FIGS. 4A and 9, the urging member 131 is a coil spring having a coil shape in which a wire is wound spirally along the front-rear direction. The urging member 131 receives the front end portion of the third transport pipe 105 therein. The biasing member 131 overlaps the protrusion 135 of the shutter 130 in the front-rear direction. Although not shown, the urging member 131 has one end portion of the wire fixed to the third transport pipe 105 and the other end portion fixed to the protruding portion 135, and the protruding portion 135 is always positioned at the second position. The shutter 130 is biased counterclockwise as viewed from the front so that the shutter 130 is positioned at the closed position.
(5) Front plate, rear plate, first side plate, and second side plate The front plate 32 is disposed at the front end of the drum unit 9 as shown in FIGS. The front plate 32 has a substantially rectangular flat plate shape that is long in the left-right direction. The front plate 32 is installed between the front end portion of the first positioning plate 28 and the front end portion of the second positioning plate 29. The front plate 32 includes a rear grip 32A.

  The rear grip 32A is disposed at the center of the front plate 32 in the left-right direction. The rear grip portion 32A has a substantially flat plate shape protruding forward from the front surface of the front plate 32 and extending in the left-right direction.

  The rear plate 33 is disposed at the rear end portion of the drum unit 9. The rear plate 33 has a substantially rectangular flat plate shape that is long in the left-right direction. The rear plate 33 is installed between the rear end portion of the first positioning plate 28 and the rear end portion of the second positioning plate 29. The rear plate 33 includes a rear grip 33A.

  The rear grip 33A is disposed at the upper end of the rear plate 33. The rear grip 33A protrudes upward from the upper surface of the rear plate 33 and extends in the left-right direction. The rear grip 33A has a substantially rectangular frame shape when viewed from the back.

  As shown in FIGS. 2 and 7, the first side plate 34 is disposed on the right side of the first positioning plate 28. The first side plate 34 has a substantially rectangular flat plate shape in a side view wider than the first positioning plate 28 in the vertical direction.

  The second side plate 35 is disposed on the left side of the second positioning plate 29. The second side plate 35 has a substantially rectangular flat plate shape in side view wider than the second positioning plate 29 in the vertical direction.

As shown in FIG. 7, the four holes 142 are arranged at intervals in the front-rear direction. The hole 142 is disposed corresponding to the photosensitive drum 11. The hole 142 has a substantially circular shape in a side view. The hole 142 receives the drum coupling 53 of the corresponding photosensitive drum 11.
3. Configuration of Belt Unit The belt unit 5 includes a frame 146 having a recess 147 as shown in FIGS. 3 and 11B.

  The frame 146 has a substantially frame shape that supports the driving roller 15, the driven roller 16, and the four transfer rollers 18 described above. The frame 146 extends outward in the left-right direction from both ends in the left-right direction of the belt 17.

The recess 147 is recessed over the entire front-rear direction at the upper right end of the frame 146.
4). Structure of Main Body Casing As shown in FIG. 1, the main body casing 2 includes a waste toner storage unit 150, a main body reference shaft 154, and a main body coupling 155 (see FIG. 7).

  The waste toner storage unit 150 is disposed below the belt unit 5. The waste toner storage unit 150 has a substantially box shape. The waste toner storage unit 150 is configured to store the toner removed by the cleaning unit 30. As shown in FIGS. 3 and 6, the waste toner storage unit 150 includes an introduction pipe 160.

  The introduction pipe 160 is disposed at the right end portion of the front end portion of the waste toner storage unit 150. The introduction pipe 160 includes a first portion 161 and a second portion 162.

  The first portion 161 has a rectangular tube shape extending in the left-right direction. The left end portion of the first portion 161 communicates with the internal space of the waste toner storage unit 150.

  The second portion 162 is disposed on the right side of the front end portion of the frame 146 of the belt unit 5. The second portion 162 has a rectangular tube shape extending in the vertical direction. The lower end portion of the second portion 162 communicates with the second portion 162.

  As shown in FIG. 1, the main body reference shaft 154 is disposed in the rear end portion of the main body casing 2. The main body reference shaft 154 is made of metal and has a substantially cylindrical shape extending in the left-right direction.

As shown in FIG. 7, the four main body couplings 155 are arranged in parallel at intervals in the front-rear direction at the left end portion of the main body casing 2. The main body coupling 155 is disposed on the left side of the corresponding photosensitive drum 11, and the right end of the main body coupling 155 fits into the drum coupling 53 of the photosensitive drum 11 when the process unit 3 is mounted on the main body casing 2. It is configured. The main body coupling 155 is configured to move along the left-right direction in conjunction with the opening / closing operation of the front cover 22 by a known interlocking mechanism. The main body coupling 155 is configured to rotate when a driving force from a driving source such as a motor (not shown) provided in the main body casing 2 is transmitted.
5. As shown in FIG. 1, when the drum unit 9 is located at the inward position in the main body casing 2, the notch 48 of the first positioning plate 28 is fitted to the right end portion of the main body reference shaft 154. ing. Although not shown, the notch 48 of the second positioning plate 29 is fitted to the left end portion of the main body reference shaft 154. Thereby, the drum unit 9 is positioned at the inward position.

  At this time, the lower end portion of the photosensitive drum 11 is in contact with the upper portion of the belt 17 as shown in FIGS. Further, as shown in FIGS. 4C and 11A, when the contact portion (not shown) of the main casing 2 is in contact with the protrusion 135, the protrusion 135 is positioned at the first position extending downward. Yes. As a result, as shown in FIGS. 4C and 11B, the shutter 130 is positioned at the open position where the communication port 134 is positioned below the shutter body 133 and communicates with the discharge port 107 of the third transport pipe 105 in the vertical direction. ing. As shown in FIGS. 9 and 11B, the discharge port 107 of the third transport pipe 105 is connected to the upper end portion of the second portion 162 of the introduction pipe 160 of the waste toner storage unit 150. The conveyance tube 80 communicates with the upper end portion of the second portion 162 of the introduction tube 160 of the waste toner storage unit 150 through the discharge port 107. Note that the third transport pipe 105 does not overlap the belt unit 5 when viewed in the vertical direction, as shown in FIG. 11B.

  Further, the first transport pipe 95 is accommodated in the recess 147 of the frame 146. Thereby, a part of the first transport pipe 95 overlaps the frame 146 of the belt unit 5 when viewed in the vertical direction.

  Further, the main body coupling 155 shown in FIG. 7 is fitted into the corresponding drum coupling 53.

  To move the drum unit 9 to the outward position, the operator first opens the front cover 22 of the main casing 2 as shown in FIG.

  Then, in conjunction with the opening operation of the front cover 22, the main body coupling 155 moves to the left and is separated from the drum coupling 53 as shown in FIG.

  Next, the operator holds the rear holding portion 32A of the drum unit 9 and pulls the drum unit 9 forward.

  At this time, the drum unit 9 moves slightly forward and upward by a guide (not shown) of the main casing 2 and then moves forward.

  Then, as the drum unit 9 moves, the projection 135 of the shutter 130 and the contact portion (not shown) are separated from each other.

  As a result, as shown in FIGS. 2 and 4A, the shutter 130 is rotated counterclockwise as viewed from the front by the urging force of the urging member 131, and the protrusion 135 extends to the second position extending to the right. And move to a closed position where the discharge port 107 is closed by the peripheral wall of the shutter body 133.

  Then, the operator further pulls the drum unit 9 forward.

  As a result, the drum unit 9 is located at the outer position, and the pulling-out operation of the drum unit is completed.

  Further, in order to position the drum unit 9 from the outer position to the inner position, the drum unit 9 is operated contrary to the above-described pulling operation.

  Specifically, the operator holds the rear holding portion 32A of the drum unit 9 and pushes the drum unit 9 backward.

  Then, the drum unit 9 moves backward. Then, during the movement of the drum unit 9, the protrusion 135 of the shutter 130 comes into contact with a contact portion (not shown) of the main body casing 2.

  Next, when the operator pushes the drum unit 9 further backward, the drum unit 9 is guided by a guide (not shown), moves rearward and downward, and is positioned at the inward position.

  At this time, as shown in FIG. 11A, the protrusion 135 of the shutter 130 is positioned at the first position by being in contact with a contact portion (not shown) of the main casing 2.

  As a result, as shown in FIG. 11B, the shutter 130 is located at the open position, and the discharge port 107 of the third transport pipe 105 is connected to the upper end portion of the second portion 162 of the introduction pipe 160 of the waste toner storage unit 150. The

  When the operator closes the front cover 22, the main body coupling 155 moves to the right by a known interlocking mechanism in conjunction with the closing operation of the front cover 22, and the corresponding drum coupling of the photosensitive drum 11 is performed. 53.

Thereby, the mounting operation of the drum unit 9 is completed.
6). Cleaning Operation Next, a cleaning operation for toner remaining on the surface of the drum body 50 of the photosensitive drum 11 will be described.

  In the image forming operation, the toner remaining on the drum body 50 of the photosensitive drum 11 is rotated by the blade 76 of the cleaning member 61 of the cleaning unit 30 as shown in FIG. The toner remaining in contact with the drum main body 50 and scraping off the surface of the drum main body 50 is scraped off and removed.

  Then, the toner removed from the surface of the drum main body 50 falls into the waste toner conveying portion 71 of the main body portion 66 of the frame 60. That is, the toner remaining on the surface of the drum body 50 is collected by the cleaning member 61.

  At this time, the cleaning conveyance member 62 rotates clockwise as viewed from the right side because the gear 78 meshes with the second flange 52 of the photosensitive drum 11.

  Accordingly, the toner in the waste toner transport unit 71 is transported to the right by the cleaning transport member 62.

  Then, the waste toner conveyed to the right in the waste toner conveyance unit 71 flows into the first conveyance tube 95 through the insertion unit 97 and the communication unit 98 of the connection unit 96 as shown in FIG. .

  At this time, as shown in FIG. 7, the second transport member 82 rotates counterclockwise as viewed from the front when the second gear 85 transmits a driving force from a driving gear (not shown) of the main casing 2. ing.

  In addition, as shown in FIG. 10, the first conveying member 81 receives a driving force from a driving gear (not shown) of the main body casing 2 via the second gear 85 to the first gear 84. , Rotate clockwise when viewed from the front.

  As a result, as shown in FIG. 9, the toner that has flowed into the first conveyance tube 95 is conveyed forward by the first conveyance member 81. The direction in which the toner is transported through the first transport pipe 95 by the first transport member 81, that is, the direction from the rear to the front is the first direction.

  Thus, the toners scraped from the surfaces of the drum bodies 50 of the four photosensitive drums 11 are collected and transported from the rear to the front in the first transport pipe 95.

  Then, the toner transported to the front end portion of the first transport pipe 95 flows into the connecting pipe 103 of the second transport section 92.

  At this time, the toner is conveyed forward by the first conveying member 81, thereby contacting the rear surface of the closing portion 93, and the toner in its own weight causes the second conveying tube 104 to move downward and right along the inclined surface 104A. And flows into the front end portion of the third transport pipe 105.

  Next, the toner flowing into the front end portion of the third transport pipe 105 is transported rearward by the second transport member 82. The direction in which the toner is transported through the third transport pipe 105 by the second transport member 82, that is, the direction from the front to the rear is the second direction.

  As a result, the toner is transported to the discharge port 107 in the third transport tube 105 and discharged to the introduction tube 160 through the discharge port 107.

  The toner is stored in the waste toner storage unit 150 through the introduction tube 160.

Thus, the cleaning operation for the toner remaining on the surface of the drum body 50 of the photosensitive drum 11 is completed.
7). Operation and Effect (1) According to this image forming apparatus 1, as shown in FIGS. 8 and 9, the toner remaining on the surface of the photosensitive drum 11 is scraped off by the blade 76 of the cleaning member 61 and cleaned. It is conveyed rightward by the conveying member 62 and flows into the conveying tube 80.

  11A and 11B, the transport pipe 80 extends in the front-rear direction, and extends to the lower right from the first transport pipe 95 that houses the first transport member 81 and the front end portion of the first transport pipe 95. Since the second transport pipe 104 is provided, the toner is transported forward in the first transport pipe 95 and transported in the lower right direction in the second transport pipe 104.

As a result, by disposing only the second transport pipe 104 in a direction that intersects with the direction in which the first transport pipe 95 extends, the toner removed by the cleaning unit 30 is discharged by the second transport pipe 104. 107, and can be smoothly discharged to the waste toner storage unit 150.
(2) Further, according to the image forming apparatus 1, as shown in FIG. 9, the second transport pipe 104 is connected to the front end portion of the first transport pipe 95 via the connection pipe 103. The toner can be collected at the front end of the first conveyance tube 95.
(3) Further, according to the image forming apparatus 1, as shown in FIG. 9, the transport pipe 80 includes the third transport pipe 105 that is connected to the second transport pipe 104 and extends in the front-rear direction. The toner can be smoothly discharged by the waste toner storage unit 150.
(4) Further, according to this image forming apparatus 1, as shown in FIGS. 4C and 11B, since the third transport pipe 105 includes the discharge port 107, the discharge port 107 is securely connected to the first transport pipe 95. Can be arranged at a position away from

Therefore, the toner transported in the transport pipe 80 can be discharged more smoothly to the waste toner storage unit 150.
(5) Further, according to the image forming apparatus 1, as shown in FIGS. 11A and 11B, the toner is discharged to the waste toner storage unit 150 by the third transport pipe 105 so as to avoid the belt unit 5. Can do.
(6) Further, according to the image forming apparatus 1, as shown in FIG. 11B, the first transport pipe 95 is accommodated in the concave portion 147 of the frame 146 that supports the belt 17, so that space saving can be achieved. The size of the image forming apparatus 1 can be suppressed.
(7) Further, according to the image forming apparatus 1, as shown in FIGS. 10 and 11B, the toner in the third transport pipe 105 can be reliably transported backward by the second transport member 82.

As a result, the toner can be prevented from staying in the conveying tube 80, and the toner can be reliably conveyed to the discharge port 107.
(8) Also, according to the image forming apparatus 1, as shown in FIGS. 11A and 11B, the first axis A1 of the first transport member 81 is higher than the second axis A2 of the second transport member 82. Therefore, the toner conveyed by the first conveying member 81 can be dropped to the second conveying member 82 by its own weight.

As a result, after the toner is transported by the first transport member 81, the toner can be reliably transported toward the waste toner storage unit 150 by the second transport member 82.
(9) According to this image forming apparatus 1, as shown in FIGS. 9 and 10, since the second conveying member 82 is an auger screw, the toner is more reliably conveyed in the third conveying tube 105. can do.
(10) According to this image forming apparatus 1, as shown in FIGS. 9 and 10, since the first conveying member 81 is an auger screw, the toner is more reliably conveyed in the first conveying tube 95. can do.
(11) Also, according to this image forming apparatus 1, as shown in FIG. 11A, since the second transport pipe 104 has the inclined surface 104A inclined downward, the first conveying line 104A extends along the inclined surface 104A. The toner can be transported from the transport tube 95 to the third transport tube 105 by its own weight.
(12) Also, according to the image forming apparatus 1, as shown in FIG. 11B, the first positioning plate 28 is disposed inward in the left-right direction so as to overlap the discharge port 107 when viewed from the up-down direction. Therefore, the drum unit 9 can be downsized.
(13) Also, according to the image forming apparatus 1, as shown in FIG. 11B, the discharge port 107 is disposed below the first positioning plate 28, so that the first positioning plate 28 is avoided. The toner can be discharged toward the waste toner storage unit 150.
(14) Also, according to this drum unit 9, as shown in FIGS. 8 and 9, the toner remaining on the surface of the photosensitive drum 11 is collected by the cleaning member 61, and right by the cleaning transport member 62. And then flows into the transport pipe 80.

  11A and 11B, the transport pipe 80 extends in the front-rear direction, and extends to the lower right from the first transport pipe 95 that houses the first transport member 81 and the front end portion of the first transport pipe 95. Since the second transport tube 104 is provided, the toner scraped off from all the photosensitive drums 11 is collected in the first transport tube 95, transported forward in the first transport tube 95, and second transported. The pipe 104 is conveyed to the lower right.

  As a result, by disposing only the second transport pipe 104 in a direction that intersects with the direction in which the first transport pipe 95 extends, the toner removed by the cleaning unit 30 is discharged by the second transport pipe 104. 107, and can be smoothly discharged to the waste toner storage unit 150.

DESCRIPTION OF SYMBOLS 1 Image forming apparatus 2 Main body casing 5 Belt unit 9 Drum unit 11 Photosensitive drum 17 Belt 28 1st positioning plate 29 2nd positioning plate 30 Cleaning unit 31 Conveyance unit 60 Frame 62 Cleaning conveyance member 76 Blade 80 Conveyance pipe 81 1st conveyance member 82 Second conveying member 84 First gear 85 Second gear 95 First conveying tube 101 Fixed hole 104 Second conveying tube 104A Inclined surface 105 Third conveying tube 107 Discharge port 130 Shutter 146 Frame 147 Concave 150 Waste toner storage unit A1 First Axis A2 Second axis

Claims (25)

A body casing;
A drum unit movable between an inner position in the main body casing and an outer position outside the main body casing,
A photosensitive drum;
A cleaning unit configured to remove toner remaining on the surface of the photosensitive drum;
A drum unit comprising a transport unit configured to transport the toner removed by the cleaning unit;
A waste toner storage unit configured to store the toner transported by the transport unit;
The transport unit is
A first conveying member configured to convey the toner removed by the cleaning unit along a moving direction of the drum unit;
A transport pipe for housing the first transport member, and a transport pipe having a discharge port for discharging the toner transported by the first transport member toward the waste toner housing unit;
The transport pipe is
A first transfer pipe extending in the moving direction and accommodating the first transfer member;
An image forming apparatus comprising: a second transport pipe connected to the first transport pipe and extending in a direction intersecting with a direction in which the first transport pipe extends.   The image forming apparatus according to claim 1, wherein the second transport pipe is connected to an end of the first transport pipe in the moving direction.   The image forming apparatus according to claim 1, wherein the transport pipe further includes a third transport pipe that is connected to the second transport pipe and extends along a direction in which the first transport pipe extends. .   The image forming apparatus according to claim 3, wherein the third transport pipe has the discharge port. A belt unit comprising a belt that contacts the photosensitive drum when the drum unit is located at the inward position;
At least a part of the first transport pipe overlaps the belt unit when viewed in the direction in which the photosensitive drum and the belt overlap.
5. The image forming apparatus according to claim 3, wherein the third transport pipe does not overlap the belt unit when viewed in a direction in which the photosensitive drum and the belt overlap. 6. The belt unit includes a frame that supports the belt,
The image forming apparatus according to claim 5, wherein the frame has a concave portion that accommodates the first transport pipe.   A second transport member disposed in the third transport pipe, the second transport member configured to transport the toner transported by the first transport member along the moving direction. The image forming apparatus according to any one of claims 3 to 6. The first transport member and the second transport member are rotatable,
The image forming apparatus according to claim 7, wherein a rotation axis of the first conveyance member is above a rotation axis of the second conveyance member.   The image forming apparatus according to claim 7, wherein the second conveying member is an auger screw.   The image forming apparatus according to claim 1, wherein the first transport member is an auger screw.   The image forming apparatus according to claim 1, wherein the second transport pipe has an inclined surface that slopes downward in a direction away from the first transport pipe. The drum unit has a positioning plate for positioning the photosensitive drum,
12. The image forming apparatus according to claim 1, wherein at least a part of the positioning plate overlaps with the discharge port when viewed in the vertical direction. The drum unit has a positioning plate for positioning the photosensitive drum,
The image forming apparatus according to claim 1, wherein the positioning plate is disposed inward of the discharge port in the axial direction of the photosensitive drum.   The image forming apparatus according to claim 12, wherein the discharge port is disposed below the positioning plate in the vertical direction. A first photosensitive drum;
A second photosensitive drum;
A first cleaning unit configured to remove toner remaining on the surface of the first photosensitive drum;
A second cleaning unit configured to remove toner remaining on the surface of the second photosensitive drum;
A transport unit configured to transport the toner removed by the first cleaning unit and the toner removed by the second cleaning unit;
The transport unit is
A toner configured to convey the toner removed by the first cleaning unit and the toner removed by the second cleaning unit along an alignment direction of the first photosensitive drum and the second photosensitive drum. 1 conveying member;
A transport pipe that accommodates the first transport member, and a transport pipe having a discharge port for discharging the toner transported by the first transport member to the outside,
The transport pipe is
A first transport pipe extending in the alignment direction and containing the first transport member;
A drum unit comprising: a second transport pipe connected to the first transport pipe and extending in a direction intersecting with a direction in which the first transport pipe extends.   The drum unit according to claim 15, wherein the second transport pipe is connected to an end of the first transport pipe in the arrangement direction.   The drum unit according to claim 15 or 16, wherein the transport pipe further includes a third transport pipe connected to the second transport pipe and extending along a direction in which the first transport pipe extends.   The drum unit according to claim 17, wherein the third transport pipe has the discharge port.   A second transport member disposed in the third transport pipe, the second transport member configured to transport the toner transported by the first transport member along the alignment direction. The drum unit according to claim 17 or 18. The first transport member and the second transport member are rotatable,
The rotation axis of the first conveying member is at a position different from the rotation axis of the second conveying member in a direction orthogonal to both the axial direction of the first photosensitive drum and the second photosensitive drum and the alignment direction. The drum unit according to claim 19, characterized in that:   The drum unit according to claim 19 or 20, wherein the second conveying member is an auger screw.   The drum unit according to any one of claims 15 to 20, wherein the first conveying member is an auger screw.   The drum unit according to any one of claims 15 to 22, wherein the second transport pipe has an inclined surface. A positioning plate for positioning the first photosensitive drum and the second photosensitive drum;
The at least part of the positioning plate overlaps the discharge port when viewed from a direction orthogonal to both the axial direction and the alignment direction of the first photosensitive drum and the second photosensitive drum. The drum unit according to any one of 15 to 23. A positioning plate for positioning the first photosensitive drum and the second photosensitive drum;
The positioning plate is disposed inward of the discharge port in the axial direction of the first photosensitive drum and the second photosensitive drum. The drum unit described.

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