Image forming device

Abstract

To provide an image forming apparatus that can increase the capacity of a toner container while preventing an increase in the size of the toner container.SOLUTION: An image forming apparatus 1 comprises a photoconductor drum 51Y, a toner container 6Y, a developing unit 53Y, a drum cleaner 55Y, and a toner tube 56Y. The toner tube 56Y allows passage of toner recovered from the drum cleaner 55Y to the toner container 6Y. The toner container 6Y has a toner discharge port 7132 and a toner reception port 71211. The toner reception port 71211 can receive a toner discharged from a discharge port 562 of the toner tube 56Y. A developing housing 531Y of the developing unit 53Y has a developer receiving port 53111 and a developer discharge port 53121. The developer receiving port 53111 can receive a toner discharged from the toner discharge port 7132. The developer discharge port 53121 can discharge a toner returned from the developing housing 531Y to the toner container 6Y to the toner tube 56Y.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present disclosure relates to an image forming apparatus. [Background technology]

[0002] Conventionally, an image forming apparatus includes a drum cartridge and a toner cartridge. The drum cartridge includes a photosensitive drum, a developing unit, a cleaner, and a transport pipe. The toner cartridge includes a waste toner storage unit and a toner storage unit. The cleaner removes toner from the circumferential surface of the photosensitive drum. The transport pipe transports the toner removed by the cleaner. The waste toner storage unit stores the toner transported through the transport pipe. The toner storage unit stores toner to be supplied to the photosensitive drum (see Patent Document 1 below). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2018-155959 Summary of the Invention [Problem to be solved by the invention]

[0004] In the image forming apparatus described in Patent Document 1, there are cases where it is desired to increase the capacity of the toner storage unit while suppressing an increase in the size of the toner cartridge.

[0005] Therefore, an object of the present disclosure is to provide an image forming apparatus that can increase the capacity of a toner container while suppressing an increase in size of the toner container. [Means for solving the problem]

[0006] (1) The image forming apparatus of the present disclosure includes a photosensitive drum, a toner container, a developing unit, a drum cleaner, and a toner tube. The photosensitive drum is rotatable about a first axis. The first axis extends in a first direction. The toner container is capable of containing toner. The developing unit is capable of supplying toner in the toner container to the photosensitive drum. The developing unit has a developing housing and a developing roller. The developing housing is capable of containing toner from the toner container. The developing roller is rotatably supported by the developing housing. The drum cleaner is capable of cleaning the circumferential surface of the photosensitive drum. The toner tube allows toner collected from the drum cleaner to the toner container to pass through. The toner tube has an outlet. The outlet is capable of discharging toner in the toner tube.

[0007] The toner container has a toner discharge port, a toner receiving port, and a toner transport member. The toner discharge port can discharge toner from the toner container. The toner receiving port can receive toner discharged from the discharge port of the toner tube. The toner transport member transports toner from the toner receiving port toward the toner discharge port.

[0008] The developing housing has a developing device receiving opening and a developing device discharging opening. The developing device receiving opening can receive the toner discharged from the toner discharging opening. The developing device discharging opening can discharge the toner to be returned from the developing housing to the toner container into the toner tube.

[0009] According to this configuration, the toner (recovered toner) collected from the photosensitive drum by the drum cleaner can be returned to the toner container through the toner tube.

[0010] This allows the collected toner to be mixed with unused toner in the toner container and then supplied to the photosensitive drum again.

[0011] Therefore, there is no need to provide a section for storing the collected toner in the toner container, and the capacity of the toner container can be increased accordingly.

[0012] As a result, the toner storage unit can have a large capacity while preventing the toner storage container from becoming too large.

[0013] The toner in the developing housing can also be returned to the toner container through the toner tube.

[0014] Therefore, the toner can be circulated between the developing unit and the toner container, thereby preventing the toner from accumulating in the developing unit.

[0015] As a result, it is possible to prevent the toner remaining in the developing unit from being repeatedly charged and degraded within the developing unit.

[0016] Furthermore, by returning the collected toner and the toner from the developing housing to the toner container through the toner tube, the collected toner and the toner from the developing housing can be mixed in the toner tube.

[0017] (2) The image forming apparatus may include a drum cartridge and a toner container. The drum cartridge has a photosensitive drum, a developing unit, a drum cleaner, and a toner tube. The toner container is detachable from the drum cartridge. When the toner container is attached to the drum cartridge, the toner receiving port can receive toner discharged from the toner tube outlet. When the toner container is attached to the drum cartridge, the developing receiving port can receive toner discharged from the toner outlet.

[0018] (3) The toner container may be aligned with the developing unit in the first direction.

[0019] (4) The toner tube may be located below the developer receiving opening.

[0020] With this configuration, the toner in the developing housing can be transported to the toner tube by utilizing gravity.

[0021] Therefore, the toner inside the developing unit can be smoothly discharged.

[0022] (5) The developing unit may further include a developer transport member that transports the toner in the developing housing toward the developer outlet.

[0023] According to this configuration, the toner inside the developing casing can be smoothly discharged by the developing transport member.

[0024] (6) The toner container may have a first toner shutter and a second toner shutter. The first toner shutter opens and closes the toner inlet. The second toner shutter opens and closes the toner outlet.

[0025] With this configuration, by closing the first toner shutter and the second toner shutter, it is possible to prevent toner in the toner container from spilling out of the toner receiving port and the toner discharging port when the toner container is removed from the drum cartridge.

[0026] (7) The image forming apparatus may have a toner tube shutter that opens and closes the discharge port.

[0027] According to this configuration, by closing the toner tube shutter, it is possible to prevent the toner in the developing unit from spilling out of the discharge port of the toner tube when the toner container is removed from the drum cartridge.

[0028] (8) The developing unit may be movable relative to the photosensitive drum. The image forming apparatus may further include a first seal member. The first seal member is positioned around the developing outlet. The first seal member seals between the toner tube and the developing unit.

[0029] According to this configuration, the first seal member can prevent toner from leaking from the developer discharge port when the developing unit moves relative to the photosensitive drum.

[0030] (9) The image forming apparatus may have a side plate. The side plate supports one end of the photosensitive drum in a first direction. The side plate is positioned in the first direction with a gap therebetween relative to one end of the developing housing in the first direction. The first seal member may be positioned between the one end of the developing housing in the first direction and the side plate.

[0031] (10) The image forming apparatus may further include a connecting pipe and a second sealing member. The connecting pipe is supported by the side plate. The connecting pipe connects the toner container and the developing housing. The connecting pipe has a connecting pipe receiving opening and a connecting pipe discharge opening. The connecting pipe receiving opening is capable of receiving toner discharged from the toner discharge opening. The connecting pipe discharge opening is capable of discharging toner in the connecting pipe to the developing housing receiving opening. The second sealing member is positioned around the connecting pipe discharge opening and the developing housing receiving opening. The second sealing member seals between the connecting pipe and the developing housing.

[0032] According to this configuration, the second seal member can prevent toner from leaking from the connecting pipe outlet and the developing device receiving port when the developing unit moves relative to the photosensitive drum.

[0033] (11) The image forming apparatus may further include a connecting pipe shutter that opens and closes the connecting pipe receiving port.

[0034] According to this configuration, by closing the connecting pipe shutter, it is possible to prevent toner in the developing unit from spilling out of the connecting pipe receiving port of the connecting pipe when the toner container is removed from the drum cartridge.

[0035] (12) An image forming apparatus may include a first photosensitive drum, a second photosensitive drum, a first toner container, a first developing unit, a second toner container, a second developing unit, a drum cleaner, and a toner tube. The first photosensitive drum is rotatable about a first axis. The second photosensitive drum is rotatable about a second axis. The second axis extends in a first direction. The second photosensitive drum is aligned with the first photosensitive drum in the second direction. The second direction intersects with the first direction. The first toner container is capable of containing toner. The first developing unit is capable of supplying toner in the first toner container to the first photosensitive drum. The first developing unit has a first developing housing and a first developing roller. The first developing housing is capable of containing toner from the first toner container. The first developing roller is rotatably supported by the first developing housing. The second toner container is capable of containing toner. The second toner container is aligned with the first toner container in the second direction. The second developing unit is capable of supplying toner in the second toner container to the second photosensitive drum. The second developing unit has a second developing housing and a second developing roller. The second developing housing is capable of storing toner from the second toner container. The second developing roller is rotatably supported by the second developing housing. The second developing unit is aligned with the first developing unit in the second direction. The drum cleaner is capable of cleaning the circumferential surface of the first photosensitive drum. The toner tube allows toner collected from the drum cleaner to pass through the first toner container.

[0036] The first toner container has a toner outlet, a toner inlet, and a toner transport member. The toner outlet allows the toner in the first toner container to be discharged.

[0037] The first developing housing has a developing device receiving opening and a developing device discharging opening, through which toner returned from the first developing housing to the first toner container can be discharged into the toner tube.

[0038] (13) The first toner container may be aligned with the first developing unit in the first direction.

[0039] (14) The first developing unit may further include a developer transport member that transports the toner in the first developing housing toward the developer outlet.

[0040] (15) The first toner container may have a first toner shutter and a second toner shutter.

[0041] (16) The first developing unit may be movable relative to the first photosensitive drum. The first sealing member may seal between the toner tube and the first developing unit.

[0042] (17) The side plate may support one end of the first photosensitive drum in the first direction. The side plate may be positioned in the first direction with a gap between it and one end of the first developing housing in the first direction. The first seal member may be positioned between the one end of the first developing housing in the first direction and the side plate.

[0043] (18) The connecting pipe may connect the first toner container and the first developing casing, and the second seal member may seal between the connecting pipe and the first developing casing. [Effects of the Invention]

[0044] According to the image forming apparatus of the present disclosure, it is possible to increase the capacity of the toner container while suppressing an increase in size of the toner container. [Brief explanation of the drawings]

[0045] [Figure 1] FIG. 1 is a schematic diagram of an image forming apparatus. [Figure 2] FIG. 2 is a cross-sectional view of the image forming apparatus shown in FIG. [Figure 3] FIG. 3 is a cross-sectional view of the image forming apparatus shown in FIG. 2, taken along a line passing through the toner container. [Figure 4] FIG. 4 is an explanatory diagram for explaining the attachment and detachment of the drum cartridge shown in FIG. [Figure 5] FIG. 5 is an explanatory diagram for explaining the attachment and detachment of the toner container shown in FIG. [Figure 6] FIG. 6 is an enlarged view of the drum cartridge shown in FIG. [Figure 7] 7 is a cross-sectional view of the drum cartridge shown in FIG. 6 taken along the line AA. [Figure 8] FIG. 8 is a side view of the drum cartridge shown in FIG. 6, as seen from one side in the first direction. [Figure 9] 9 is a cross-sectional view of the drum cartridge shown in FIG. 6 taken along the line BB. [Figure 10] 10 is a cross-sectional view of the drum cartridge shown in FIG. 6 taken along line CC. [Figure 11] FIG. 11 is an enlarged view of the toner container shown in FIG. [Figure 12] 12 is a cross-sectional view of the toner container shown in FIG. 11 taken along the line DD. [Figure 13] 13 is a cross-sectional view of the toner container shown in FIG. 11 taken along the line E-E. [Figure 14] 14 is a cross-sectional view of the toner container shown in FIG. 11 taken along the line FF. [Figure 15] FIG. 15 is a cross-sectional view of the toner container shown in FIG. 11 taken along line GG. DETAILED DESCRIPTION OF THE INVENTION

[0046] 1. Overview of image forming apparatus 1 An overview of the image forming apparatus 1 will be described with reference to Figures 1 to 5. In the following description, the "vertical direction" refers to the vertical direction when the image forming apparatus 1 is placed on a horizontal surface.

[0047] As shown in Figures 1 to 3, the image forming apparatus 1 includes a main body housing 2, a cover 3 (see Figure 2), a sheet storage section 4, a plurality of drum cartridges 5Y, 5M, 5C, and 5K, a plurality of toner storage containers 6Y, 6M, 6C, and 6K (see Figure 3), an exposure device 7, an intermediate transfer unit 8, a transfer roller 9, and a fixing device 10.

[0048] 1.1 Main body casing 2 The main body housing 2 houses a sheet storage section 4, drum cartridges 5Y, 5M, 5C, and 5K, toner storage containers 6Y, 6M, 6C, and 6K, an exposure device 7, an intermediate transfer unit 8, a transfer roller 9, and a fixing device 10.

[0049] 2, the main body housing 2 has an opening 21. The opening 21 is located at one end of the main body housing 2 in the first direction. 1.2 Cover 3 2 and 4, the cover 3 is movable between a cover closed position (see FIG. 2) and a cover open position (see FIG. 4). As shown in FIG. 2, when the cover 3 is in the cover closed position, the cover 3 closes the opening 21. As shown in FIG. 4, when the cover 3 is in the open position, the opening 21 is open.

[0050] 1.3 Sheet storage section 4 1, the sheet storage unit 4 is capable of storing sheets S. The sheets S in the sheet storage unit 4 are conveyed toward a transfer roller 9.

[0051] 1.4 Drum Cartridge 5Y The drum cartridge 5Y is detachably mountable within the main body housing 2. Specifically, as shown in Fig. 4, with the cover 3 in the cover open position, the drum cartridge 5Y is detachably mountable within the main body housing 2 through the opening 21 in the first direction.

[0052] 1, the drum cartridge 5Y includes a photosensitive drum 51Y, a charging roller 52Y, and a developing unit 53Y. In other words, the image forming apparatus 1 includes the photosensitive drum 51Y and the developing unit 53Y.

[0053] 1.4.1 Photosensitive drum 51Y The photosensitive drum 51Y has a cylindrical shape. When the drum cartridge 5Y is installed in the main body housing 2, the photosensitive drum 51Y extends in a first direction. The photosensitive drum 51Y is rotatable about a first axis A1. When the drum cartridge 5Y is installed in the main body housing 2, the first axis A1 extends in the first direction.

[0054] 1.4.2 Charging Roller 52Y The charging roller 52Y charges the photosensitive drum 51Y. The drum cartridge 5Y may have a scorotron type charger instead of the charging roller 52Y.

[0055] 1.4.3 Developing Unit 53Y The developing unit 53Y is capable of supplying toner in a toner container 6Y (see FIG. 2) to the photosensitive drum 51Y. The developing unit 53Y includes a developing housing 531Y and a developing roller 532Y.

[0056] The developing casing 531Y can store toner from the toner container 6Y.

[0057] The developing roller 532Y is capable of supplying toner in the developing housing 531Y to the photosensitive drum 51Y. The developing roller 532Y is rotatably supported by the developing housing 531Y. The developing roller 532Y contacts the photosensitive drum 51Y. The developing roller 532Y may be separable from the photosensitive drum 51Y. When the drum cartridge 5Y is mounted in the main body housing 2, the developing roller 532Y extends in the first direction. The developing roller 532Y is rotatable about the developing axis A11. When the drum cartridge 5Y is mounted in the main body housing 2, the developing axis A11 extends in the first direction.

[0058] 1.5 Drum Cartridge 5M, 5C, 5K Each of the drum cartridges 5M, 5C, and 5K has the same structure as the drum cartridge 5Y.

[0059] In other words, the drum cartridge 5M includes a photosensitive drum 51M and a developing unit 53M. In other words, the image forming apparatus 1 includes the photosensitive drum 51M and the developing unit 53M. The photosensitive drum 51M is rotatable about a second axis A2. When the drum cartridge 5Y is installed in the main body housing 2, the second axis A2 extends in the first direction. When the drum cartridge 5Y and the drum cartridge 5M are installed in the main body housing 2, the photosensitive drum 51M is aligned with the photosensitive drum 51Y in the second direction. The second direction intersects with the first direction. The developing unit 53M is capable of supplying toner in a toner container 6M (see FIG. 3) to the photosensitive drum 51M. The developing unit 53M includes a developing housing 531M and a developing roller 532M. The developing housing 531M is capable of storing toner from the toner container 6M. The developing roller 532M is rotatably supported by the developing housing 531M. When the drum cartridge 5Y and the drum cartridge 5M are mounted in the main body casing 2, the developing unit 53M is aligned with the developing unit 53Y in the second direction.

[0060] A description of each of the drum cartridges 5C and 5K will be omitted.

[0061] 1.6 Toner containers 6Y, 6M, 6C, and 6K As shown in FIG. 5, the toner container 6Y is detachable from the drum cartridge 5Y. More specifically, when the cover 3 is in the cover open position and the drum cartridge 5Y is installed in the main body housing 2, the toner container 6Y is detachable from the drum cartridge 5Y through the opening 21 in the first direction. The toner container 6Y can store toner. Note that the image forming apparatus 1 may prompt the user to replace the toner container 6Y when a predetermined amount of toner remains in the toner container 6Y. As shown in FIG. 2, when the toner container 6Y is installed in the drum cartridge 5Y, the toner container 6Y is aligned with the developing unit 53Y in the first direction.

[0062] 3, each of the toner containers 6M, 6C, and 6K has the same structure as the toner container 6Y. When the toner container 6Y is attached to the drum cartridge 5Y and the toner container 6M is attached to the drum cartridge 5M, the toner container 6M is aligned with the toner container 6Y in the second direction. A description of each of the toner containers 6M, 6C, and 6K will be omitted.

[0063] 1.7 Exposure equipment 7 1, with the drum cartridges 5Y, 5M, 5C, and 5K installed in the main body housing 2, the exposure device 7 can expose the circumferential surface of the photosensitive drum 51Y charged by the charging roller 52Y, the circumferential surface of the photosensitive drum 51M charged by the charging roller 52M, the circumferential surface of the photosensitive drum 51C charged by the charging roller 52C, and the circumferential surface of the photosensitive drum 51K charged by the charging roller 52K. In this embodiment, the exposure device 7 is a laser scan unit. The exposure device 7 may also be an LED head.

[0064] The developing unit 53Y supplies toner to the exposed circumferential surface of the photosensitive drum 51Y. The developing unit 53M supplies toner to the exposed circumferential surface of the photosensitive drum 51M. The developing unit 53C supplies toner to the exposed circumferential surface of the photosensitive drum 51C. The developing unit 53K supplies toner to the exposed circumferential surface of the photosensitive drum 51K.

[0065] 1.8 Intermediate Transfer Unit 8 When the drum cartridges 5Y, 5M, 5C, and 5K are installed in the main body housing 2, the intermediate transfer unit 8 is located above the drum cartridges 5Y, 5M, 5C, and 5K. The intermediate transfer unit 8 includes an intermediate transfer belt 81 and transfer rollers 82Y, 82M, 82C, and 82K.

[0066] When the drum cartridges 5Y, 5M, 5C, and 5K are installed in the image forming apparatus 1, the intermediate transfer belt 81 comes into contact with the photosensitive drums 51Y, 51M, 51C, and 51K.

[0067] The transfer roller 82Y transfers the toner on the photosensitive drum 51Y onto the intermediate transfer belt 81. The transfer roller 82M transfers the toner on the photosensitive drum 51M onto the intermediate transfer belt 81. The transfer roller 82C transfers the toner on the photosensitive drum 51C onto the intermediate transfer belt 81. The transfer roller 82K transfers the toner on the photosensitive drum 51K onto the intermediate transfer belt 81.

[0068] 1.9 Transfer roller 9 The transfer roller 9 transfers the toner on the intermediate transfer belt 81 onto the sheet S. More specifically, the sheet S transported from the sheet storage unit 4 toward the transfer roller 9 passes between the transfer roller 9 and the intermediate transfer belt 81 and is transported to the fixing device 10. At this time, the transfer roller 9 transfers the toner on the intermediate transfer belt 81 onto the sheet S.

[0069] 1.10 Fixing device 10 The fixing device 10 applies heat and pressure to the sheet S onto which the toner has been transferred, thereby fixing the toner to the sheet S. After passing through the fixing device 10, the sheet S is discharged onto the top surface of the main body casing 2.

[0070] 2. Details of the 5Y drum cartridge In the present disclosure, when the drum cartridge 5Y is mounted in the main body housing 2 and the toner container 6Y is mounted in the drum cartridge 5Y, the drum cartridge 5Y and the toner container 6Y can collect toner that remains on the circumferential surface of the photosensitive drum 51Y without being transferred from the photosensitive drum 51Y to the sheet S. Hereinafter, the toner collected from the photosensitive drum 51Y into the toner container 6Y is defined as collected toner.

[0071] Furthermore, when the drum cartridge 5Y is mounted in the main body housing 2 and the toner container 6Y is mounted in the drum cartridge 5Y, the drum cartridge 5Y and the toner container 6Y can circulate toner between the developing housing 531Y and the toner container 6Y. This allows the developing unit 53Y to supply recovered toner mixed with unused toner in the toner container 6Y to the photosensitive drum 51Y again. Unused toner is toner that has never been supplied to the photosensitive drum 51Y. In the following description, toner returned from the developing housing 531Y to the toner container 6Y is defined as returned toner.

[0072] The drum cartridge 5Y will be described in detail below with reference to Figures 6 to 10. In the following description of the drum cartridge 5Y, the "first direction" and the "vertical direction" refer to the first direction and the vertical direction when the drum cartridge 5Y is installed in the main body housing 2.

[0073] 6, drum cartridge 5Y includes, in addition to photosensitive drum 51Y, charging roller 52Y, and developing unit 53Y, a drum frame 54Y, a drum cleaner 55Y (see FIG. 9), a toner tube 56Y, a toner tube shutter 57Y, a first seal member 58Y (see FIG. 10), a toner tube transport member 59Y (see FIG. 10), a connecting tube 60Y, a connecting tube shutter 61Y, a second seal member 62Y (see FIG. 10), and a connecting tube transport member 63Y (see FIG. 10). In other words, image forming apparatus 1 includes drum cleaner 55Y, toner tube 56Y, a toner tube shutter 57Y, a first seal member 58Y, a connecting tube 60Y, a connecting tube shutter 61Y, and a second seal member 62Y.

[0074] 2.1 Drum Frame 54Y 6, the drum frame 54Y extends in the first direction. The drum frame 54Y has side plates 541A and 541B. That is, the image forming apparatus 1 has the side plate 541A.

[0075] The side plate 541A is located at one end of the drum frame 54Y in the first direction. The side plate 541A is located at a distance in the first direction from one end of the developing casing 531Y in the first direction. The side plate 541A extends in a direction intersecting the first direction. Preferably, the side plate 541A extends in a direction perpendicular to the first direction. The side plate 541A supports one end of the photosensitive drum 51Y in the first direction. As shown in FIG. 7, the side plate 541A has two holes 5411A, 5412A.

[0076] The hole 5411A is positioned away from the photosensitive drum 51Y in the third direction. The third direction is a direction connecting the first axis A1 and the development axis A11. The hole 5411A extends in the third direction. The hole 5411A is an elongated hole.

[0077] The hole 5412A is located between the hole 5411A and the photosensitive drum 51Y in the third direction. The hole 5412A extends in the third direction. The hole 5412A is an elongated hole.

[0078] As shown in FIG. 6, the side plate 541B is located at the other end of the drum frame 54Y in the first direction. The side plate 541B is located at a distance in the first direction from the other end of the developing housing 531Y in the first direction. The side plate 541B extends in a direction intersecting the first direction. Preferably, the side plate 541B extends in a direction perpendicular to the first direction. The side plate 541B supports the other end of the photosensitive drum 51Y in the first direction. As shown in FIG. 8, the side plate 541B has two holes 5411B, 5412B.

[0079] The hole 5411B is positioned away from the photosensitive drum 51Y in the third direction. The hole 5411B extends in the third direction. The hole 5411B is an elongated hole.

[0080] The hole 5412B is located between the hole 5411B and the photosensitive drum 51Y in the third direction. The hole 5412B extends in the third direction. The hole 5412B is an elongated hole.

[0081] 2.2 Details of the Developer Unit 53Y As shown in FIG. 9, in addition to the developing housing 531Y and developing roller 532Y described above, the developing unit 53Y further has two protrusions 533A, 534A (see FIG. 7), two protrusions 533B, 534B (see FIG. 8), a first developing transport member 535Y, and a second developing transport member 536Y as a developing transport member.

[0082] 2.2.2 Details of the developing unit 531Y 6, the developing housing 531Y extends in the first direction and has a partition wall 5310 (see FIG. 9), a developing device receiving portion 5311 (see FIG. 10), and a developing device discharging portion 5312 (see FIG. 10).

[0083] As shown in FIG. 9, the partition wall 5310 divides the internal space of the developing housing 531Y into a first internal space 531A and a second internal space 531B. The first internal space 531A accommodates a portion of the developing roller 532Y. The partition wall 5310 has a passage 53101. The passage 53101 communicates the first internal space 531A with the second internal space 531B. The passage 53101 is located at the other end of the partition wall 5310 in the first direction.

[0084] As shown in FIG. 10, the developer receiving portion 5311 is located at one end of the developing housing 531Y in the first direction. The developer receiving portion 5311 extends in the first direction. The developer receiving portion 5311 has a cylindrical shape. The internal space of the developer receiving portion 5311 communicates with the first internal space 531A (see FIG. 9). The developer receiving portion 5311 has a developer receiving opening 53111. In other words, the developing housing 531Y has the developer receiving opening 53111.

[0085] When the drum cartridge 5Y is mounted in the main body housing 2 and the toner container 6Y is mounted in the drum cartridge 5Y, the developer receiving opening 53111 can receive toner discharged from the toner discharge opening 7132 (see FIG. 14) of the toner container 6Y. More specifically, when the drum cartridge 5Y is mounted in the main body housing 2 and the toner container 6Y is mounted in the drum cartridge 5Y, the developer receiving opening 53111 can receive, from the connecting pipe outlet 6012, toner that has been discharged from the toner discharge opening 7132 and passed through the connecting pipe 60Y. The toner discharge opening 7132 and the connecting pipe outlet 6012 will be described later. The developer receiving opening 53111 communicates with the internal space of the developer receiving portion 5311.

[0086] The developer discharge portion 5312 is located at one end of the developing casing 531Y in the first direction. The developer discharge portion 5312 extends in the first direction. The developer discharge portion 5312 has a cylindrical shape. The internal space of the developer discharge portion 5312 communicates with the second internal space 531B (see FIG. 9). The developer discharge portion 5312 has a developer discharge port 53121. In other words, the developing casing 531Y has the developer discharge port 53121.

[0087] The developer discharge port 53121 can discharge the returned toner into the toner tube 56Y. This allows the collected toner from the drum cleaner 55Y to be mixed with the returned toner from the developer casing 531Y in the toner tube 56Y. The developer discharge port 53121 communicates with the internal space of the developer discharge portion 5312.

[0088] 2.2.3 Protrusions 533A, 534A, 533B, 534B 7, the protrusion 533A fits into a hole 5411A in the side plate 541A. The protrusion 533A extends from one outer surface of the developing housing 531Y in the first direction. The protrusion 533A extends in the first direction. The protrusion 533A has a cylindrical shape.

[0089] The protrusion 534A fits into the hole 5412A of the side plate 541A. The protrusion 534A extends from one outer surface of the developing housing 531Y in the first direction. The protrusion 534A is located away from the protrusion 533A. The protrusion 534A extends in the first direction. In this embodiment, the protrusion 534A extends along the developing axis A11. The protrusion 534A may be one end of the developing roller shaft in the first direction. The protrusion 534A has a cylindrical shape.

[0090] 8, the protrusion 533B fits into a hole 5411B in the side plate 541B. The protrusion 533B extends from the other outer surface of the developing housing 531Y in the first direction. The protrusion 533B extends in the first direction. The protrusion 533B has a cylindrical shape.

[0091] The protrusion 534B fits into the hole 5412B of the side plate 541B. The protrusion 534B extends from the other outer surface of the developing housing 531Y in the first direction. The protrusion 534B is located away from the protrusion 533B. The protrusion 534B extends in the first direction. In this embodiment, the protrusion 534B extends along the developing axis A11. The protrusion 534B may be the other end of the developing roller shaft in the first direction. The protrusion 534B has a cylindrical shape.

[0092] The developing unit 53Y is movable in the third direction relative to the photosensitive drum 51Y by fitting the protrusion 533A into the hole 5411A, the protrusion 534A into the hole 5412A, the protrusion 533B into the hole 5411B, and the protrusion 534B into the hole 5412B.

[0093] 2.2.4 First Development Conveying Member 535Y As shown in Fig. 9, the first developer transport member 535Y is located in the first internal space 531A of the developer casing 531Y. The first developer transport member 535Y transports toner from the developer receiving opening 53111 (see Fig. 10) toward the passage 53101. The first developer transport member 535Y extends in a first direction. In this embodiment, the first developer transport member 535Y is an auger screw.

[0094] 2.2.5 Second developing transport member 536Y The second developer transport member 536Y is located in the second internal space 531B of the developing housing 531Y. The second developer transport member 536Y transports toner from the passage 53101 toward the developing housing discharge port 53121 (see FIG. 10). That is, the second developer transport member 536Y transports toner in the developing housing 531Y toward the developing housing discharge port 53121. The second developer transport member 536Y extends in the first direction. In this embodiment, the second developer transport member 536Y is an auger screw.

[0095] 2.3 Drum Cleaner 55Y The drum cleaner 55Y is capable of cleaning the circumferential surface of the photosensitive drum 51Y. The drum cleaner 55Y removes toner from the circumferential surface of the photosensitive drum 51Y that has not been transferred from the photosensitive drum 51Y to the sheet S and remains on the circumferential surface of the photosensitive drum 51Y. The toner removed from the circumferential surface of the photosensitive drum 51Y by the drum cleaner 55Y becomes recovered toner.

[0096] The drum cleaner 55Y includes a cleaner housing 551, a cleaning member 552, and a collected toner transport member 553.

[0097] The cleaner housing 551 is located between the side plate 541A (see FIG. 6) and the side plate 541B (see FIG. 6) in the first direction. The cleaner housing 551 extends in the first direction. One end of the cleaner housing 551 in the first direction is connected to the side plate 541A. The other end of the cleaner housing 551 in the first direction is connected to the side plate 541B. The cleaner housing 551 has an opening 5511. The cleaner housing 551 stores collected toner.

[0098] The cleaning member 552 is attached to the cleaner housing 551. The cleaning member 552 extends in a first direction. The cleaning member 552 has a plate shape. The cleaning member 552 cleans the circumferential surface of the photosensitive drum 51Y. Specifically, the edge of the cleaning member 552 comes into contact with the circumferential surface of the photosensitive drum 51Y. When the photosensitive drum 51Y rotates, toner on the circumferential surface of the photosensitive drum 51Y comes into contact with the edge of the cleaning member 552 and is removed from the circumferential surface of the photosensitive drum 51Y. The removed toner passes through the opening 5511 and is contained in the cleaner housing 551.

[0099] The collected toner transport member 553 is located inside the cleaner housing 551. The collected toner transport member 553 transports the toner inside the cleaner housing 551 in a first direction toward the toner tube 56Y. In this embodiment, the collected toner transport member 553 is an auger screw.

[0100] 2.4 Toner Tube 56Y 6, the toner tube 56Y extends in a first direction. The toner tube 56Y penetrates the side plate 541A in the first direction. One end of the toner tube 56Y in the first direction is located on the opposite side of the side plate 541A from the developing housing 531Y. The other end of the toner tube 56Y in the first direction is located between the developing housing 531Y and the side plate 541A.

[0101] As shown in FIG. 10, the other end of the toner tube 56Y in the first direction is connected to one end of the cleaner housing 551 in the first direction. The toner tube 56Y communicates with the cleaner housing 551. This allows the toner tube 56Y to receive recovered toner from the drum cleaner 55Y. The toner tube 56Y allows the passage of recovered toner collected from the drum cleaner 55Y to the toner container 6Y. When the drum cartridge 5Y is installed in the main body housing 2, the toner tube 56Y is located below the drum cleaner 55Y. When the drum cartridge 5Y is installed in the main body housing 2, the toner tube 56Y is located below the recovered toner transport member 553. Furthermore, when the drum cartridge 5Y is installed in the main body housing 2, the toner tube 56Y is located below the developing device receiving port 53111. The toner tube 56Y has a return toner receiving port 561 and a discharge port 562 (see FIG. 7).

[0102] The returned toner receiving port 561 is capable of receiving the returned toner discharged from the developing device discharge port 53121. The returned toner receiving port 561 is located at the other end of the toner tube 56Y in the first direction. The returned toner receiving port 561 communicates with the internal space of the toner tube 56Y.

[0103] 7, the discharge port 562 is located at one end of the toner tube 56Y in the first direction. The discharge port 562 communicates with the internal space of the toner tube 56Y. The discharge port 562 allows the toner inside the toner tube 56Y to be discharged.

[0104] 2.5 Toner tube shutter 57Y As shown in FIG. 6, the toner tube shutter 57Y is located at one end of the toner tube 56Y in the first direction. The toner tube shutter 57Y is located on the circumferential surface of the toner tube 56Y. The toner tube shutter 57Y opens and closes the discharge port 562 (see FIG. 7). Specifically, the toner tube shutter 57Y is movable relative to the toner tube 56Y between a closed position (see FIG. 6) and an open position (see FIG. 2). The toner tube shutter 57Y in the open position (see FIG. 2) is closer to the side plate 541A in the first direction than the toner tube shutter 57Y in the closed position (see FIG. 6). The toner tube shutter 57Y is movable in the first direction between the closed position and the open position. When the toner tube shutter 57Y is in the closed position, the toner tube shutter 57Y closes the discharge port 562. When the toner tube shutter 57Y is in the open position, the discharge port 562 is open. The toner tube shutter 57Y in the open position is pressed by the spring 571 toward the closed position.

[0105] 2.6 First seal member 58Y As shown in FIG. 10, the first seal member 58Y is located between the developer discharge portion 5312 and the other end of the toner tube 56Y in the first direction. The first seal member 58Y is located around the developer discharge port 53121 and the return toner receiving port 561. The first seal member 58Y seals between the toner tube 56Y and the developing unit 53Y. More specifically, the first seal member 58Y seals between the other end of the toner tube 56Y in the first direction and the developer discharge portion 5312. The first seal member 58Y is elastically deformable in response to movement of the developing unit 53Y. The first seal member 58Y is made of, for example, a sponge.

[0106] As shown in FIG. 6, the first seal member 58Y is located between one end of the developing casing 531Y in the first direction and the side plate 541A.

[0107] 2.7 Toner tube transport member 59Y 7 and 10, toner tube transport member 59Y is located inside toner tube 56Y. Toner tube transport member 59Y transports toner inside toner tube 56Y in a first direction toward discharge port 562. In this embodiment, toner tube transport member 59Y is an auger screw.

[0108] 2.8 Connecting pipe 60Y 2, when the drum cartridge 5Y is mounted in the main body housing 2 and the toner container 6Y is mounted in the drum cartridge 5Y, the connecting pipe 60Y connects the toner container 6Y to the developing housing 531Y. As shown in FIG. 6, the connecting pipe 60Y has a connecting pipe main body 601 and an insertion portion 602.

[0109] 2.8.1 Connecting pipe body 601 The connecting pipe main body 601 extends in the first direction. The connecting pipe main body 601 has a cylindrical shape. The connecting pipe main body 601 penetrates the side plate 541A in the first direction. The connecting pipe main body 601 is supported by the side plate 541A. As a result, the connecting pipe 60Y is supported by the side plate 541A. One end of the connecting pipe main body 601 in the first direction is located on the opposite side of the side plate 541A from the developing housing 531Y. The other end of the connecting pipe main body 601 in the first direction is located between the developing housing 531Y and the side plate 541A. As shown in FIG. 10 , when the drum cartridge 5Y is attached to the main housing 2, the connecting pipe main body 601 is located above the developing device receiving opening 53111.

[0110] 7 and 10, the connecting pipe main body 601 has a connecting pipe receiving port 6011 (see FIG. 7) and a connecting pipe discharge port 6012 (see FIG. 10). In other words, the connecting pipe 60Y has the connecting pipe receiving port 6011 and the connecting pipe discharge port 6012.

[0111] 7, the connecting pipe receiving port 6011 is located at one end of the connecting pipe 60Y in the first direction. The connecting pipe receiving port 6011 communicates with the internal space of the connecting pipe main body 601. When the drum cartridge 5Y is installed in the main body housing 2 and the toner container 6Y is installed in the drum cartridge 5Y, the connecting pipe receiving port 6011 can receive toner discharged from the toner discharge port 7132 (see FIG. 14).

[0112] 10 , the connecting pipe outlet 6012 is located at the other end of the connecting pipe 60Y in the first direction. The connecting pipe outlet 6012 communicates with the internal space of the connecting pipe main body 601. The connecting pipe outlet 6012 communicates with the developing device receiving port 53111. The connecting pipe outlet 6012 can discharge toner inside the connecting pipe 60Y to the developing device receiving port 53111.

[0113] 2.8.2 Insertion section 602 As shown in FIG. 7, the insertion portion 602 is aligned with the connection pipe main body 601 in the radial direction of the connection pipe main body 601. The insertion portion 602 extends in a first direction. The insertion portion 602 has a cylindrical shape. The insertion portion 602 is connected to the circumferential surface of the connection pipe main body 601. The internal space of the insertion portion 602 communicates with the connection pipe receiving port 6011. As shown in FIG. 2, when the drum cartridge 5Y is installed in the main body housing 2 and the toner container 6Y is installed in the drum cartridge 5Y, the toner discharge portion 713 (see FIG. 11) of the toner container 6Y is inserted into the insertion portion 602. When the toner discharge portion 713 is inserted into the insertion portion 602, the connection pipe receiving port 6011 (see FIG. 7) communicates with the toner discharge port 7132 (see FIG. 14) of the toner discharge portion 713.

[0114] 2.9 Connecting pipe shutter 61Y As shown in FIGS. 6 and 7, the connecting pipe shutter 61Y is located within the insertion section 602. The connecting pipe shutter 61Y opens and closes the connecting pipe receiving port 6011 (see FIG. 7). Specifically, the connecting pipe shutter 61Y is movable between a closed position (see FIG. 6) and an open position (see FIG. 2) relative to the insertion section 602 of the connecting pipe 60Y. The connecting pipe shutter 61Y located in the open position (see FIG. 2) is located closer to the side plate 541A in the first direction than the connecting pipe shutter 61Y located in the closed position (see FIG. 6). The connecting pipe shutter 61Y is movable in the first direction between the closed position and the open position. As shown in FIG. 6, when the connecting pipe shutter 61Y is located in the closed position, the connecting pipe shutter 61Y closes the connecting pipe receiving port 6011. As shown in FIG. 2, when the connecting pipe shutter 61Y is located in the open position, the connecting pipe receiving port 6011 is open. The connecting pipe shutter 61Y in the open position is pressed by the spring 611 toward the closed position.

[0115] 2.10 Second seal member 62Y 10, the second seal member 62Y is located between the developing device receiving portion 5311 and the other end of the connecting pipe main body 601 in the first direction. The second seal member 62Y is located around the connecting pipe outlet 6012 and the developing device receiving port 53111. The second seal member 62Y seals between the connecting pipe 60Y and the developing device housing 531Y. More specifically, the second seal member 62Y seals between the other end of the connecting pipe 60Y in the first direction and the developing device receiving portion 5311.

[0116] As shown in FIG. 6, the second seal member 62Y is located between one end of the developing casing 531Y in the first direction and the side plate 541A.

[0117] 2.11 Connecting pipe carrying member 63Y 7 and 10, connecting pipe conveying member 63Y is located inside connecting pipe main body 601. Connecting pipe conveying member 63Y conveys toner inside connecting pipe main body 601 in a first direction toward connecting pipe discharge port 6012. In this embodiment, connecting pipe conveying member 63Y is an auger screw.

[0118] 3. Details of Toner Container 6Y Next, the toner container 6Y will be described in detail with reference to Figures 11 to 15. In the following description of the toner container 6Y, the "first direction" and the "vertical direction" refer to the first direction and the vertical direction "in a state in which the drum cartridge 5Y is mounted in the main body housing 2 and the toner container 6Y is mounted in the drum cartridge 5Y."

[0119] As shown in FIG. 11, the toner container 6Y includes a toner housing 71Y, a first toner shutter 72Y, a first toner transport member 73Y (see FIG. 12), a second toner shutter 74Y, a second toner transport member 75Y (see FIG. 12), and a third toner transport member 76Y (see FIG. 12) as a toner transport member.

[0120] 3.1 Toner housing 71Y 11, the toner housing 71Y extends in the first direction and the vertical direction. As shown in FIG.

[0121] 3.1.1 Partition Wall 711 The partition wall 711 divides the internal space of the toner housing 71Y into a first internal space 71A and a second internal space 71B. The first internal space 71A is located higher than the second internal space 71B. As shown in FIG. 13 , the partition wall 711 has a passage 7111. The passage 7111 connects the first internal space 71A and the second internal space 71B. The passage 7111 is located in the center of the partition wall 711 in the first direction. Toner in the first internal space 71A passes through the passage 7111 and enters the second internal space 71B.

[0122] 3.1.2 Toner Receiving Unit 712 As shown in Fig. 11, the toner receiving portion 712 is located at the lower end of the toner housing 71Y. As shown in Fig. 2, when the drum cartridge 5Y is installed in the main body housing 2 and the toner container 6Y is installed in the drum cartridge 5Y, the toner receiving portion 712 can receive toner discharged from the toner tube 56Y (see Fig. 6). As shown in Fig. 14, the toner receiving portion 712 has a toner receiving portion main body 7121 and an insertion portion 7122.

[0123] The toner receiving portion main body 7121 extends in the first direction. The toner receiving portion main body 7121 has a cylindrical shape. As shown in FIGS. 12 and 14, the toner receiving portion main body 7121 has a toner receiving opening 71211 (see FIG. 14) and a passage 71212 (see FIG. 12). In other words, the toner container 6Y has the toner receiving opening 71211.

[0124] 14, the toner receiving opening 71211 is located at the other end of the toner receiving portion main body 7121 in the first direction. The toner receiving opening 71211 communicates with the internal space of the toner receiving portion main body 7121. When the drum cartridge 5Y is installed in the main body housing 2 and the toner container 6Y is installed in the drum cartridge 5Y, the toner receiving opening 71211 can receive toner discharged from the discharge opening 562 (see FIG. 7) of the toner tube 56Y.

[0125] 12, the passage 71212 is located at one end of the toner receiving body 7121 in the first direction. The passage 71212 connects the internal space of the toner receiving body 7121 with the second internal space 71B of the toner housing 71Y. The toner in the toner receiving body 7121 passes through the passage 71212 and enters the second internal space 71B of the toner housing 71Y.

[0126] As shown in FIG. 14, the insertion portion 7122 is aligned with the toner receiving portion main body 7121 in the radial direction of the toner receiving portion main body 7121. The insertion portion 7122 extends in a first direction. The insertion portion 7122 has a cylindrical shape. The insertion portion 7122 is connected to the circumferential surface of the toner receiving portion main body 7121. The internal space of the insertion portion 7122 communicates with the toner receiving opening 71211. As shown in FIG. 2, when the drum cartridge 5Y is installed in the main housing 2 and the toner container 6Y is installed in the drum cartridge 5Y, the toner tube 56Y (see FIG. 6) of the drum cartridge 5Y is inserted into the insertion portion 7122 (see FIG. 11). When the toner tube 56Y is inserted into the insertion portion 7122, the toner receiving opening 71211 (see FIG. 14) communicates with the outlet 562 (see FIG. 7) of the toner tube 56Y.

[0127] 3.1.3 Toner discharge unit 713 As shown in FIG. 11, the toner discharge portion 713 is located in the center of the toner housing 71Y in the up-down direction. The toner discharge portion 713 is capable of discharging toner from the toner housing 71Y. The toner discharge portion 713 extends in the first direction. As shown in FIGS. 14 and 15, the toner discharge portion 713 has a passage 7131 (see FIG. 15) and a toner discharge port 7132 (see FIG. 14). In other words, the toner container 6Y has the toner discharge port 7132.

[0128] 15, the passage 7131 is located at one end of the toner discharge portion 713 in the first direction. The passage 7131 connects the internal space of the toner discharge portion 713 with the second internal space 71B of the toner housing 71Y. The toner in the second internal space 71B flows into the toner discharge portion 713 through the passage 7131.

[0129] 14, the toner discharge port 7132 is located at the other end of the toner discharge portion 713 in the first direction. The toner discharge port 7132 communicates with the internal space of the toner discharge portion 713. The toner discharge port 7132 can discharge toner inside the toner discharge portion 713. More specifically, the toner discharge port 7132 can discharge toner that has entered the toner discharge portion 713 from the second internal space 71B of the toner casing 71Y. This allows the toner discharge port 7132 to discharge toner inside the toner container 6Y.

[0130] 3.2 First toner shutter 72Y As shown in FIGS. 11 and 14, the toner first shutter 72Y is located within the insertion portion 7122. The toner first shutter 72Y opens and closes the toner receiving port 71211. Specifically, the toner first shutter 72Y is movable relative to the insertion portion 7122 between a closed position (see FIG. 11) and an open position (see FIG. 2). The toner first shutter 72Y (see FIG. 2) located in the open position is closer to the toner housing 71Y in the first direction than the toner first shutter 72Y (see FIG. 11) located in the closed position. The toner first shutter 72Y is movable in the first direction between the closed position and the open position. As shown in FIG. 11, when the toner first shutter 72Y is located in the closed position, the toner first shutter 72Y closes the toner receiving port 71211 (see FIG. 14). As shown in FIG. 2, when the toner first shutter 72Y is located in the open position, the toner receiving port 71211 is open. The first toner shutter 72Y located in the open position is pressed by the spring 721 toward the closed position.

[0131] 3.3 First toner transport member 73Y 12 and 14, the first toner transport member 73Y is located inside the toner receiving part main body 7121. The first toner transport member 73Y transports the toner inside the toner receiving part main body 7121 in a first direction toward the passage 71212 (see FIG. 12). In this embodiment, the first toner transport member 73Y is an auger screw.

[0132] 3.4 Second toner shutter 74Y As shown in FIGS. 11 and 14, the toner second shutter 74Y is located at the other end of the toner discharge portion 713 in the first direction. The toner second shutter 74Y is located on the circumferential surface of the toner discharge portion 713. The toner second shutter 74Y opens and closes the toner discharge port 7132 (see FIG. 14). Specifically, the toner second shutter 74Y is movable between a closed position (see FIG. 11) and an open position (see FIG. 2) relative to the toner discharge portion 713. The toner second shutter 74Y (see FIG. 2) located in the open position is located closer to the toner housing 71Y in the first direction than the toner second shutter 74Y (see FIG. 11) located in the closed position. The toner second shutter 74Y is movable in the first direction between the closed position and the open position. As shown in Fig. 11, when the second toner shutter 74Y is in the closed position, the second toner shutter 74Y closes the toner discharge port 7132 (see Fig. 14). As shown in Fig. 2, when the second toner shutter 74Y is in the open position, the toner discharge port 7132 is open. The second toner shutter 74Y in the open position is pressed toward the closed position by the spring 741.

[0133] 3.5 Second toner transport member 75Y 14 and 15, the second toner transport member 75Y is located inside the toner discharge portion 713. The second toner transport member 75Y transports the toner inside the toner discharge portion 713 in the first direction toward the toner discharge port 7132. In this embodiment, the second toner transport member 75Y is an auger screw.

[0134] 3.6 Third toner transport member 76Y As shown in FIGS. 12, 13, and 15, the toner third transport member 76Y is located in the second internal space 71B of the toner housing 71Y. The toner third transport member 76Y can transport the toner in the second internal space 71B in the first direction while stirring it. As a result, the collected toner and the returned toner are mixed with the unused toner from the first internal space 71A in the second internal space 71B. Specifically, the toner third transport member 76Y transports the toner in the second internal space 71B from the passage 71212 (see FIG. 12) toward the passage 7131 (see FIG. 15). In other words, the toner third transport member 76Y transports the toner from the toner receiving portion 712 toward the toner discharge portion 713. That is, the toner third transport member 76Y transports the toner from the toner receiving opening 71211 toward the toner discharge opening 7132.

[0135] 4. Effects (1) According to the image forming apparatus 1, as shown in Fig. 10, the toner tube 56Y can receive the recovered toner from the drum cleaner 55Y. Then, as shown in Fig. 2, when the drum cartridge 5Y is mounted in the main body casing 2 and the toner container 6Y is mounted in the drum cartridge 5Y, the recovered toner that has entered the toner tube 56Y is transported to the toner container 6Y through the toner tube 56Y.

[0136] That is, the collected toner can be returned to the toner container 6Y through the toner tube 56Y.

[0137] This allows the collected toner to be mixed with unused toner in the toner container 6Y and then supplied to the photosensitive drum 51Y again.

[0138] Therefore, there is no need to provide a portion for storing the collected toner in the toner container 6Y, and the capacity of the toner container 6Y can be increased accordingly.

[0139] As a result, the toner container 6Y can be increased in capacity while preventing the toner container 6Y from becoming too large.

[0140] As shown in FIG. 10, the toner tube 56Y can receive the returned toner from the developer discharge portion 5312 of the developing casing 531Y.

[0141] This allows the toner in the developing casing 531Y to be returned to the toner container 6Y through the toner tube 56Y.

[0142] Therefore, the toner is circulated between the developing unit 53Y and the toner container 6Y, and the toner can be prevented from accumulating in the developing unit 53Y.

[0143] As a result, it is possible to prevent the toner remaining in the developing unit 53Y from being repeatedly charged and degraded in the developing unit 53Y.

[0144] Furthermore, the collected toner and the returned toner from the developing casing 531Y are returned to the toner container 6Y through the toner tube 56Y, so that the collected toner and the returned toner can be mixed in the toner tube 56Y.

[0145] (2) According to the image forming apparatus 1, the toner tube 56Y is located below the developing port 53111, as shown in FIG.

[0146] Therefore, the toner in the developing casing 531Y can be transported to the toner tube 56Y by utilizing gravity.

[0147] As a result, the toner inside the developing unit 53Y can be smoothly discharged.

[0148] (3) According to the image forming apparatus 1, as shown in FIGS. 9 and 10, the developing unit 53Y includes a second developing transport member 536Y.

[0149] Therefore, the toner inside the developing casing 531Y can be smoothly discharged by the second developing conveying member 536Y.

[0150] (4) According to the image forming apparatus 1, as shown in FIG. 11, the toner container 6Y has a first toner shutter 72Y and a second toner shutter 74Y.

[0151] Therefore, by closing the first toner shutter 72Y and the second toner shutter 74Y, it is possible to prevent the toner in the toner container 6Y from spilling out from the toner receiving port 71211 and the toner discharge port 7132 when the toner container 6Y is removed from the drum cartridge 5Y.

[0152] (5) According to the image forming apparatus 1, as shown in FIG. 6, the drum cartridge 5Y has a toner tube shutter 57Y.

[0153] Therefore, by closing the toner tube shutter 57Y, it is possible to prevent the toner in the developing unit 53Y from spilling out from the discharge port 562 of the toner tube 56Y when the toner container 6Y is removed from the drum cartridge 5Y.

[0154] (6) According to the image forming apparatus 1, the drum cartridge 5Y includes a first seal member 58Y, as shown in FIG.

[0155] Therefore, the first seal member 58Y can prevent toner from leaking from the developing device discharge port 53121 when the developing unit 53Y moves relative to the photosensitive drum 51Y.

[0156] (7) According to the image forming apparatus 1, the drum cartridge 5Y includes a second seal member 62Y, as shown in Figure 10. The second seal member 62Y is positioned around the connecting pipe outlet 6012 and the developing device receiving opening 53111.

[0157] Therefore, the second seal member 62Y can prevent toner from leaking from the connecting pipe outlet 6012 and the developing device receiving port 53111 when the developing unit 53Y moves relative to the photosensitive drum 51Y.

[0158] (8) According to the image forming apparatus 1, the drum cartridge 5Y includes the connecting pipe shutter 61Y.

[0159] Therefore, by closing the connecting pipe shutter 61Y, it is possible to prevent the toner in the developing unit 53Y from spilling out from the connecting pipe receiving port 6011 of the connecting pipe 60Y when the toner container 6Y is removed from the drum cartridge 5Y. [Explanation of symbols]

[0160] 1. Image forming device 5Y drum cartridge 6Y Toner container (first toner container) 6M Toner Container (Second Toner Container) 51Y Photosensitive drum (first photosensitive drum) 51M Photosensitive drum (second photosensitive drum) 53Y Development unit (first development unit) 53M Development Unit (Second Development Unit) 55Y Drum Cleaner 56Y Toner Tube 57Y Toner tube shutter 58Y First sealing member 60Y connecting pipe 61Y Connection pipe shutter 62Y Second seal member 72Y Toner 1st shutter 74Y Toner 2nd shutter 76Y Third toner transport member (toner transport member) 531Y Developing unit (first developing unit) 531M Developer Case (Second Developer Case) 532Y Developing roller (first developing roller) 532M Developing Roller (Second Developing Roller) 536Y Second developing conveying member (developing conveying member) 541A side plate 562 Outlet 6011 Connection pipe receiving port 6012 Connecting pipe outlet 7132 Toner outlet 53111 Developing port 53121 Developing outlet 71211 Toner receiving slot A1 First axis A2 2nd axis

Claims

1. a photosensitive drum rotatable about a first axis extending in a first direction; a toner container capable of storing toner; a developing unit capable of supplying the toner in the toner container to the photosensitive drum, the developing unit having a developing casing capable of accommodating the toner from the toner container, and a developing roller rotatably supported by the developing casing; a drum cleaner capable of cleaning the peripheral surface of the photosensitive drum; a toner tube that allows passage of toner collected from the drum cleaner to the toner container, the toner tube having an outlet that allows the toner inside the toner tube to be discharged; Equipped with The toner container is a toner discharge port through which the toner in the toner container can be discharged; a toner receiving port capable of receiving the toner discharged from the discharge port of the toner tube; a toner transport member for transporting the toner from the toner receiving opening toward the toner discharging opening, The developing housing includes: a developing receiving port capable of receiving the toner discharged from the toner discharge port; a developer discharge port capable of discharging the toner returned from the developing housing to the toner container into the toner tube, The toner container is aligned with the developing unit in the first direction.

2. A photosensitive drum rotatable about a first axis extending in a first direction; a toner container capable of storing toner; a developing unit capable of supplying the toner in the toner container to the photosensitive drum, the developing unit having a developing casing capable of accommodating the toner from the toner container and a developing roller rotatably supported by the developing casing, the developing unit being movable relative to the photosensitive drum; a drum cleaner capable of cleaning the peripheral surface of the photosensitive drum; a toner tube that allows passage of toner collected from the drum cleaner to the toner container, the toner tube having an outlet that allows the toner inside the toner tube to be discharged; A first seal member; Equipped with The toner container is a toner discharge port through which the toner in the toner container can be discharged; a toner receiving port capable of receiving the toner discharged from the discharge port of the toner tube; a toner transport member for transporting the toner from the toner receiving opening toward the toner discharging opening, The developing housing includes: a developing receiving port capable of receiving the toner discharged from the toner discharge port; a developer discharge port capable of discharging the toner returned from the developing housing to the toner container into the toner tube, The first seal member is positioned around the developer outlet and seals between the toner tube and the developing unit.

3. the image forming apparatus, a side plate supporting one end of the photosensitive drum in the first direction, the side plate being positioned in the first direction with a gap between it and one end of the developing housing in the first direction; The image forming apparatus according to claim 2 , wherein the first seal member is positioned between one end of the developing housing in the first direction and the side plate.

4. the image forming apparatus, a connecting pipe supported by the side plate and connecting the toner container and the developing housing, the connecting pipe having a connecting pipe receiving port capable of receiving the toner discharged from the toner discharge port and a connecting pipe discharge port capable of discharging the toner in the connecting pipe to the developing housing receiving port; The image forming apparatus according to claim 3 , further comprising a second seal member positioned around the connecting pipe outlet and the developing device receiving port to seal between the connecting pipe and the developing device housing.

5. The image forming apparatus according to claim 4 , further comprising a connecting pipe shutter that opens and closes the connecting pipe receiving port.

6. the image forming apparatus, a drum cartridge having the photosensitive drum, the developing unit, the drum cleaner, and the toner tube; the toner container is detachable from the drum cartridge, When the toner container is attached to the drum cartridge, the toner receiving port can receive the toner discharged from the discharge port of the toner tube, 6. The image forming apparatus according to claim 1, wherein the developing device receiving opening is capable of receiving the toner discharged from the toner discharge opening when the toner container is attached to the drum cartridge.

7. The image forming apparatus according to claim 1 , wherein the toner tube is located below the developer receiving opening.

8. The developing unit comprises: The image forming apparatus according to claim 1 , further comprising a developer transport member configured to transport the toner in the developing housing toward the developer outlet.

9. The toner container is a first toner shutter that opens and closes the toner receiving opening; The image forming apparatus according to claim 1 , further comprising: a second toner shutter that opens and closes the toner discharge port.

10. The image forming apparatus according to claim 1 , further comprising a toner tube shutter that opens and closes the discharge port.

11. a first photosensitive drum rotatable about a first axis extending in a first direction; a second photosensitive drum rotatable about a second axis extending in the first direction and aligned with the first photosensitive drum in a second direction intersecting the first direction; a first toner container capable of containing toner; a first developing unit capable of supplying the toner in the first toner container to the first photosensitive drum, the first developing unit having a first developing casing capable of accommodating the toner from the first toner container, and a first developing roller rotatably supported by the first developing casing; a second toner container capable of containing toner, the second toner container being aligned with the first toner container in the second direction; a second developing unit capable of supplying the toner in the second toner container to the second photosensitive drum, the second developing unit having a second developing casing capable of accommodating the toner from the second toner container and a second developing roller rotatably supported by the second developing casing, the second developing unit being aligned with the first developing unit in the second direction; a drum cleaner capable of cleaning the peripheral surface of the first photosensitive drum; a toner tube that allows passage of the toner collected from the drum cleaner to the first toner container, the toner tube having an outlet that allows the toner inside the toner tube to be discharged; Equipped with The first toner container is a toner discharge port through which the toner in the first toner container can be discharged; a toner receiving port capable of receiving the toner discharged from the discharge port of the toner tube; a toner transport member for transporting the toner from the toner receiving opening toward the toner discharging opening, The first developing housing includes: a developing receiving port capable of receiving the toner discharged from the toner discharge port; a developer discharge port capable of discharging the toner returned from the first developing housing to the first toner container into the toner tube, The image forming apparatus, wherein the first toner container is aligned with the first developing unit in the first direction.

12. A first photosensitive drum rotatable about a first axis extending in a first direction; a second photosensitive drum rotatable about a second axis extending in the first direction and aligned with the first photosensitive drum in a second direction intersecting the first direction; a first toner container capable of containing toner; a first developing unit capable of supplying the toner in the first toner container to the first photosensitive drum, the first developing unit having a first developing casing capable of accommodating the toner from the first toner container and a first developing roller rotatably supported by the first developing casing, and movable relative to the first photosensitive drum; a second toner container capable of containing toner, the second toner container being aligned with the first toner container in the second direction; a second developing unit capable of supplying the toner in the second toner container to the second photosensitive drum, the second developing unit having a second developing casing capable of accommodating the toner from the second toner container and a second developing roller rotatably supported by the second developing casing, the second developing unit being aligned with the first developing unit in the second direction; a drum cleaner capable of cleaning the peripheral surface of the first photosensitive drum; a toner tube that allows passage of the toner collected from the drum cleaner to the first toner container, the toner tube having an outlet that allows the toner inside the toner tube to be discharged; A first seal member; Equipped with The first toner container is a toner discharge port through which the toner in the first toner container can be discharged; a toner receiving port capable of receiving the toner discharged from the discharge port of the toner tube; a toner transport member for transporting the toner from the toner receiving opening toward the toner discharging opening, The first developing housing includes: a developing receiving port capable of receiving the toner discharged from the toner discharge port; a developer discharge port capable of discharging the toner returned from the first developing housing to the first toner container into the toner tube, The first seal member is positioned around the developer discharge port and seals between the toner tube and the first developing unit.

13. the image forming apparatus, a side plate supporting one end of the first photosensitive drum in the first direction, the side plate being positioned in the first direction with a gap between it and one end of the first developing casing in the first direction; The image forming apparatus according to claim 12 , wherein the first seal member is located between one end of the first developing casing in the first direction and the side plate.

14. the image forming apparatus, a connecting pipe supported by the side plate and connecting the first toner container and the first developing housing, the connecting pipe having a connecting pipe receiving port capable of receiving the toner discharged from the toner discharge port and a connecting pipe discharge port capable of discharging the toner in the connecting pipe to the developing housing receiving port; a second seal member positioned around the connecting pipe outlet and the developing device receiving port, and sealing between the connecting pipe and the first developing device housing; The image forming apparatus according to claim 13 , further comprising: a connecting pipe shutter that opens and closes the connecting pipe receiving port.

15. The image forming apparatus according to claim 11 , wherein the toner tube is located below the developer receiving port.

16. The first developing unit is The image forming apparatus according to claim 11 , further comprising a developer transport member configured to transport the toner in the first developing housing toward the developer outlet.

17. The first toner container is a first toner shutter that opens and closes the toner discharge port; The image forming apparatus according to claim 11 , further comprising: a second toner shutter that opens and closes the toner receiving opening.

18. The image forming apparatus according to claim 11 , further comprising a toner tube shutter that opens and closes the discharge port.

Images