Image forming device

Abstract

This makes it possible to simplify the toner transport path from the toner cartridge to the developing container. [Solution] The first and second developing units are aligned in a second direction perpendicular to a first direction, which is the direction of the rotational axis of the photosensitive drum, and the first cartridge 200Y and the second cartridge 200M are disposed at one end of the image forming device 100 in the second direction. When viewed in a third direction perpendicular to both the first and second directions, the second cartridge 200M is disposed so that at least a portion of it overlaps with the first cartridge 200M. Furthermore, in the first direction, one end of the first cartridge 200Y is disposed on the side of the first end of the image forming device 100, and a first discharge opening is provided at this end. Furthermore, in the first direction, one end of the second cartridge 200M is disposed on the side of the first end of the image forming device 100, and a second discharge opening is provided at this end.

Description

[Technical Field]

[0001] The present invention relates to an image forming apparatus such as a printer, a copying machine, or a facsimile machine that uses an electrophotographic method. [Background technology]

[0002] 2. Description of the Related Art Conventionally, in an electrophotographic image forming apparatus, a configuration is known in which a detachable toner cartridge is used to replenish toner to a developing container of a developing device disposed in the image forming apparatus.

[0003] Patent Document 1 discloses an image forming apparatus in which toner bottles are attached to a plurality of supply containers provided corresponding to a plurality of developer containers, respectively, so that toner can be supplied to the developer containers without replacing the developer containers. In the image forming apparatus described in Patent Document 1, four photosensitive drums that can rotate about rotation axes extending in a first direction are aligned in a second direction perpendicular to the first direction. The four supply containers are aligned in the first direction at one end of the image forming apparatus in the second direction. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Publication No. 2023-7030 Summary of the Invention [Problem to be solved by the invention]

[0005] By making the toner cartridge detachable at one end of the image forming apparatus in the second direction, which is the alignment direction of the multiple photosensitive drums, it is possible to improve the operability of toner replenishment.

[0006] However, the toner transport path from the toner cartridge to the developing container needs to be arranged so as to avoid an exposure device such as a laser scanner and the optical path from the exposure device to the photosensitive drum. Therefore, as described in Patent Document 1, a configuration in which four toner cartridges are aligned in a first direction (the direction of the rotation axis of the photosensitive drum) perpendicular to the second direction has the following problem: That is, for at least two toner cartridges that are arranged inside the image forming device and not adjacent to the end of the image forming device, the toner transport path from the toner cartridge to the developing container needs to detour once to the outside of the exposure device and its optical path.

[0007] As described above, the conventional configuration requires a complicated toner transport path, which poses problems such as the need to increase the size of the image forming apparatus and to reduce the toner storage volume (toner capacity) of the toner cartridge in order to secure space for the toner transport path.

[0008] SUMMARY OF THE INVENTION It is therefore an object of the present invention to simplify the toner transport path from the toner cartridge to the developing container. [Means for solving the problem]

[0009] The above object can be achieved by an image forming apparatus according to the present invention. In summary, a representative configuration of the present invention is an image forming apparatus including: an apparatus main body including a first photosensitive drum rotatable about a first rotation axis extending in a first direction, a first developing unit including a first developing container that accommodates a first toner to be supplied to the first photosensitive drum and a first developing roller that carries the first toner accommodated in the first developing container, a second photosensitive drum rotatable about a second rotation axis extending in the first direction, and a second developing unit including a second developing container that accommodates a second toner to be supplied to the second photosensitive drum and a second developing roller that carries the second toner accommodated in the second developing container; a first cartridge detachable from the apparatus main body, the first cartridge accommodating the first toner and having a first discharge port for discharging the first toner toward the first developing container; and a second cartridge detachable from the apparatus main body, the second cartridge accommodating the second toner and having a second discharge port for discharging the second toner toward the second developing container. an image forming apparatus, characterized in that the first developing unit and the second developing unit are arranged to be aligned in a second direction perpendicular to the first direction, the first cartridge and the second cartridge are arranged at one end of the image forming apparatus in the second direction, and when viewed in a third direction perpendicular to both the first direction and the second direction, the second cartridge is arranged so that at least a portion of it overlaps with the first cartridge, and when one end and the other end of the image forming apparatus in the first direction are defined as a first end and a second end, respectively, in the first direction, one end of the first cartridge is arranged on the side of the first end of the image forming apparatus, and the first ejection outlet is provided at the end of the first cartridge that is on the side of the first end of the image forming apparatus, and in the first direction, one end of the second cartridge is arranged on the side of the first end of the image forming apparatus, and the second ejection outlet is provided at the end of the second cartridge that is on the side of the first end of the image forming apparatus. [Effects of the Invention]

[0010] According to the present invention, it is possible to simplify the toner transport path from the toner cartridge to the developing container. [Brief explanation of the drawings]

[0011] [Figure 1] 1 is a schematic cross-sectional view showing a general configuration of an image forming apparatus. [Figure 2] FIG. 1 is a perspective view of an appearance of an image forming apparatus. [Figure 3] FIG. 2 is a perspective view of the appearance of the image forming apparatus with the front door open. [Figure 4] FIG. 2 is a perspective view of the image forming apparatus showing a state in which a cartridge is being removed. [Figure 5] FIG. 2 is a front view of the image forming unit according to the first embodiment. [Figure 6] FIG. 2 is a perspective view of an image forming unit. [Figure 7] FIG. 2 is a perspective view of the image forming unit from which the cartridge has been removed. [Figure 8] FIG. 2 is a top view of the image forming unit and the laser scanner. [Figure 9] FIG. 2 is a top view of the image forming unit showing the optical path of laser light. [Figure 10] FIG. 2 is a side view of the image forming unit and the laser scanner. [Figure 11] 5 is a schematic diagram for explaining the positional relationship between a supply pipe, a discharge port, and the optical path of a laser beam. FIG. [Figure 12] 3A and 3B are a perspective view and a front view of the image forming unit for explaining the conveying device; [Figure 13] 10A and 10B are a front view and a perspective view of an image forming unit in a second embodiment. [Figure 14] 11A and 11B are a front view and a perspective view of an image forming unit according to a third embodiment. [Figure 15] 10A and 10B are a front view and a perspective view of an image forming unit in a fourth embodiment. [Figure 16] 13A and 13B are a front view and a perspective view of an image forming unit in a fifth embodiment. [Figure 17]13A and 13B are a front view and a perspective view of an image forming unit in a sixth embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0012] The image forming apparatus according to the present invention will be described in more detail below with reference to the drawings.

[0013] [Example 1] <Configuration of image forming device> 1 is a schematic cross-sectional view showing the general configuration of an image forming apparatus 100 of this embodiment (showing a cross section substantially perpendicular to the direction of the rotation axis of a photosensitive drum 1, which will be described later). The image forming apparatus 100 of this embodiment is a tandem-type full-color laser printer that employs an intermediate transfer system and is capable of forming a full-color image on a sheet-like recording material S using an electrophotographic image forming process (electrophotographic process).

[0014] Image forming apparatus 100 has four process units PY, PM, PC, and PK as multiple process units within main body housing 120. The four process units PY, PM, PC, and PK form toner images (toner images, developer images) of yellow (Y), magenta (M), cyan (C), and black (K), respectively. The four process units PY, PM, PC, and PK are similar in configuration except that the colors of toner contained inside developing containers 3 of developing units 5, which will be described later, are different. Elements provided for each color and having the same or corresponding functions or configurations may be generally described by omitting the Y, M, C, or K suffix to the reference numerals indicating that the elements are for one of the colors.

[0015] The four process units PY, PM, PC, and PK are aligned (substantially parallel in this embodiment) along the moving direction of a primary transfer surface 16 of the intermediate transfer belt 11, which will be described later. More specifically, the photosensitive drums 1 and developing units 5 constituting each of the four process units PY, PM, PC, and PK are aligned (substantially parallel in this embodiment) along the moving direction of the primary transfer surface 16 of the intermediate transfer belt 11.

[0016] Here, with respect to the image forming apparatus 100 and its components, the direction of the rotation axis of the photosensitive drum 1 (the longitudinal direction of the process unit P, the developing unit 5, and the drum unit 6) is defined as the "first direction (X direction)." That is, the photosensitive drum 1 is rotatable about a rotation axis extending in the first direction. Furthermore, with respect to the image forming apparatus 100 and its components, the direction perpendicular to the first direction is defined as the "second direction (Y direction)." The four process units PY, PM, PC, and PK are aligned in the second direction. That is, the alignment direction of the four process units PY, PM, PC, and PK (more specifically, the photosensitive drum 1 and the developing unit 5) is the second direction. Furthermore, with respect to the image forming apparatus 100 and its components, the direction perpendicular to both the first and second directions is defined as the "third direction (Z direction)." Furthermore, with respect to the image forming apparatus 100 and its elements, "up" and "down" refer to the direction of gravity (vertical direction), but do not necessarily mean directly above or directly below. They also include the upper and lower sides of a horizontal plane passing through a position or element of interest. The image forming apparatus 100 is used for image formation, positioned so that the first direction is substantially parallel to the horizontal direction and the second direction intersects with the direction of gravity. In FIG. 1, the image forming apparatus 100 is depicted with the second direction substantially parallel to the horizontal direction, but as shown in FIG. 10, the second direction may be angled relative to the horizontal direction. Furthermore, with respect to the image forming apparatus 100, the right side in FIG. 1 is referred to as the "front (FE)" side, the left side in FIG. 1 is referred to as the "back (BE)" side, the left side as viewed from the front side is referred to as the "left side (LE)" side, and the right side as viewed from the front side is referred to as the "right side (RE)" side. In this embodiment, the four process units PY, PM, PC, and PK are arranged in this order from the back side to the front side along the second direction.

[0017] The process unit P has electrophotographic process elements. A drive output unit (not shown) provided in the main body housing 120 transmits to the process unit P the rotational drive force of a rotating member (such as a photosensitive drum 1 and a developing roller 4, which will be described later). A bias voltage (such as a charging bias and a developing bias, which will be described later) is also supplied to the process unit P from a bias application unit (not shown) provided in the main body housing 120.

[0018] The process unit P has drum units 6 (6Y, 6M, 6C, 6K). The drum units 6 (6Y, 6M, 6C, 6K) have photosensitive drums 1 (1Y, 1M, 1C, 1K) as image carriers and charging rollers 2 (2Y, 2M, 2C, 2K) which are roller-type charging members and serve as charging means for charging the photosensitive drums 1. The charging rollers 2 constitute process means that act on the photosensitive drums 1. The photosensitive drums 1 are rotatable about a rotation axis extending in the first direction. The drum unit 6 is configured such that the photosensitive drums 1, the charging rollers 2, etc. are held in a drum unit frame 61.

[0019] The process unit P also has developing units (developing devices) 5 (5Y, 5M, 5C, 5K) as developing means for developing the electrostatic latent image formed on the photosensitive drum 1. The developing units 5 constitute process means acting on the photosensitive drum 1. The developing units 5 have developing containers 3 (3Y, 3M, 3C, 3K) that contain toner as developer, and developing rollers 4 (4Y, 4M, 4C, 4K) that serve as developer carriers (developing members). The developing containers 3Y, 3M, 3C, 3K contain yellow, magenta, cyan, and black toner, respectively. The developing rollers 4 carry and transport the toner contained in the developing containers 3 and supply it to the surface of the photosensitive drum 1. In this embodiment, the toner as developer is a non-magnetic one-component developer. In this embodiment, the developing unit 5 deposits toner charged with the same polarity as the charge polarity of the photosensitive drum 1 (negative in this embodiment) to the exposed portion of the photosensitive drum 1, which has been uniformly charged and then exposed to light, thereby reducing the absolute value of the potential. In this embodiment, the normal charge polarity of the toner, which is the main charge polarity of the toner during development, is negative. The developing unit 5 is configured such that the developing roller 4 and other components are held in a frame that constitutes the developing container 3.

[0020] Within the device housing 120, above the process unit P, a laser scanner unit (exposure unit, exposure device) 8 is provided as exposure means for exposing the photosensitive drum 1 to light to form an electrostatic latent image (electrostatic image) on the photosensitive drum 1. The laser scanner unit 8 outputs laser light corresponding to image signals (image information) for each color of yellow, magenta, cyan, and black, and irradiates the photosensitive drums 1Y, 1M, 1C, and 1K with the light. The optical paths of the laser light from the laser scanner unit 8 to the photosensitive drums 1Y, 1M, 1C, and 1K are designated as optical paths LY, LM, LC, and LK, respectively. The laser light passes through exposure windows 7 (7Y, 7M, 7C, and 7K) of the laser scanner unit 8 to scan and expose the surface of the photosensitive drum 1. Note that the exposure means is not limited to the laser scanner unit 8 and may be, for example, an LED exposure unit.

[0021] Within the main body housing 120, an intermediate transfer belt unit 10 serving as a transfer device is provided below the process unit P (on the opposite side of the laser scanner unit 8 across the process unit P in the third direction). The intermediate transfer belt unit 10 includes an intermediate transfer belt 11 serving as an intermediate transfer body, a drive roller 12, a tension roller 13, and an assist roller 14 serving as a plurality of tension rollers, and primary transfer rollers 15Y, 15M, 15C, and 15K serving as primary transfer means. The intermediate transfer belt 11, which is a flexible endless belt, is stretched over the drive roller 12, the tension roller 13, and the assist roller 14 and stretched with a predetermined tension. The lower surfaces of the photosensitive drums 1Y, 1M, 1C, and 1K contact a primary transfer surface 16, which is the upper surface of the intermediate transfer belt 11. The primary transfer surface 16 is the surface of the intermediate transfer belt 11 onto which the toner image is transferred from the photosensitive drum 1, and is formed by the surface of the intermediate transfer belt 11 stretched between a drive roller 12 and a tension roller 13. Primary transfer rollers 15Y, 15M, 15C, and 15K, which are roller-type primary transfer members serving as primary transfer means, are disposed on the inner circumferential surface of the intermediate transfer belt 11, facing the photosensitive drums 1Y, 1M, 1C, and 1K across the intermediate transfer belt 11. The primary transfer rollers 15 are pressed against the photosensitive drums 1 via the intermediate transfer belt 11, forming primary transfer portions N1 (N1Y, N1M, N1C, and N1K) that are contact portions between the photosensitive drums 1 and the intermediate transfer belt 11. Furthermore, a secondary transfer roller 20, serving as secondary transfer means, is disposed on the outer circumferential surface of the intermediate transfer belt 11, facing the drive roller 12 across the intermediate transfer belt 11. The secondary transfer roller 20 is pressed against the drive roller 12 via the intermediate transfer belt 11, and forms a secondary transfer portion N2, which is a contact portion between the intermediate transfer belt 11 and the secondary transfer roller 20.

[0022] Within the main body housing 120, a feeding unit 30 serving as a feeding means is provided below the intermediate transfer belt unit 10. The feeding unit 30 has a feeding tray 31 serving as a recording material storage section that stores a stack of recording materials (recording media, transfer materials, sheets) S such as paper or plastic sheets, and a feeding roller 32 serving as a feeding member that picks up and transports the recording material S from the feeding tray 31. Furthermore, within the main body housing 120, a registration roller pair 40 serving as a transport member is provided downstream of the feeding unit 30 in the transport direction of the recording material S and upstream of the secondary transfer portion N2.

[0023] Also, within the main body housing 120, a fixing unit (fixing device) 50 is provided downstream of the secondary transfer portion N2 in the conveying direction of the recording material S (above the process unit P) as a fixing means for fixing the toner image to the recording material S. Also, within the main body housing 120, a discharge roller 60 is provided downstream of the fixing unit 50 in the conveying direction of the recording material S (above the fixing unit 50) for discharging the recording material S with the fixed toner image to the outside of the main body housing 120. Also, outside (at the top) of the main body housing 120, a discharge tray 70 is provided on which the recording material S discharged from the main body housing 120 is stacked.

[0024] In this embodiment, the discharge rollers 60 discharge the recording material S in the second direction from the rear side to the front side. That is, in this embodiment, the downstream side in the discharge direction of the recording material S by the discharge rollers 60 is the front side (front side) of the image forming apparatus 100, and the upstream side in the discharge direction of the recording material S is the rear side (rear side) of the image forming apparatus 100.

[0025] <Image formation operation> Next, the image forming operation of the image forming apparatus 100 of this embodiment will be described using an example of forming a full-color image.

[0026] During image formation, the photosensitive drum 1 is driven to rotate at a predetermined rotation speed (circumferential speed) in the direction of arrow R1 in FIG. 1 (counterclockwise). Furthermore, as the drive roller 12 is driven to rotate, the intermediate transfer belt 11 rotates (circumferentially moves) in the direction of arrow R2 in FIG. 1 (clockwise) at a rotation speed corresponding to the rotation speed of the photosensitive drum 1. At the contact portion between the photosensitive drum 1 and the intermediate transfer belt 11, the surfaces of the photosensitive drum 1 and the intermediate transfer belt 11 move in the forward direction. The tension rollers other than the drive roller 12 and the primary transfer roller 15 are rotated in accordance with the rotation of the intermediate transfer belt 11.

[0027] Also, the laser scanner unit 8 starts to drive. In synchronization with the start of the laser scanner unit 8, the surface of the photosensitive drum 1 is uniformly charged to a predetermined potential of a predetermined polarity (negative polarity in this embodiment) by the charging roller 2. During charging, a charging voltage (charging bias) of the same polarity as the charging polarity of the photosensitive drum 1 is applied to the charging roller 2. The charged surface of the photosensitive drum 1 is scanned and exposed by the laser scanner unit 8 with laser light according to image signals of colors corresponding to each process unit P, and an electrostatic latent image according to the image signals of each color is formed on the photosensitive drum 1.

[0028] The electrostatic latent image formed on the photosensitive drum 1 is developed (visualized) by the development unit 5, which supplies toner to the surface of the photosensitive drum 1. The development unit 5 supplies toner to the surface of the photosensitive drum 1 by the development roller 4, which is driven to rotate clockwise in FIG. 1 at a predetermined rotational speed. During development, a development voltage (development bias) of the same polarity as the charge polarity of the photosensitive drum 1 is applied to the development roller 4. Through the above process, toner images of yellow, magenta, cyan, and black are formed on the photosensitive drums 1Y, 1M, 1C, and 1K, respectively. The toner images formed on the photosensitive drums 1Y, 1M, 1C, and 1K are transferred (primary transfer) at primary transfer sections N1Y, N1M, N1C, and N1K to the same image forming area on the rotating intermediate transfer belt 11 so as to be sequentially superimposed on each other. During the primary transfer, a primary transfer voltage (primary transfer bias) having a polarity opposite to the normal charging polarity of the toner (positive polarity in this embodiment) is applied to the primary transfer roller 15.

[0029] In this way, four-color toner images (yellow, magenta, cyan, and black) constituting a full-color image are formed on the intermediate transfer belt 11. Meanwhile, at predetermined control timing, recording materials S are separated and fed one by one from the feed tray 31 by the feed roller 32. The recording materials S are introduced into the secondary transfer section N2 at predetermined control timing by the registration roller pair 40. Then, as the recording materials S are sandwiched and conveyed between the intermediate transfer belt 11 and the secondary transfer roller 20 at the secondary transfer section N2, the toner images on the intermediate transfer belt 11 are transferred (secondary transfer) onto the recording materials S. During the secondary transfer, a secondary transfer voltage (secondary transfer bias) having a polarity opposite to the normal charging polarity of the toner (positive polarity in this embodiment) is applied to the secondary transfer roller 20. The drive roller 12 is electrically grounded (connected to a ground potential). The secondary transfer roller 20 is rotated in accordance with the rotation of the intermediate transfer belt 11.

[0030] The recording material S onto which the toner image has been transferred is heated and pressurized by the fixing unit 50, and the toner image is fixed (melted and adhered) onto the recording material S. The recording material S onto which the toner image has been fixed is discharged (output) onto a discharge tray 70 by a discharge roller 60.

[0031] The image forming apparatus 100 can also form a monochrome image (such as a black monochrome image) or a multicolor image using a desired single or multiple process units P.

[0032] The process unit P may also have a cleaning means for removing residual toner from the photosensitive drum 1. The cleaning means may be a cleaning device that uses a cleaning blade as a cleaning member to scrape off toner from the surface of the rotating photosensitive drum 1 and store the toner in a cleaning container.

[0033] The image forming apparatus 100 may also have a cleaning unit that removes residual toner from the intermediate transfer belt 11. The same cleaning device as described above can be used as this cleaning unit.

[0034] <Toner supply overview> Next, an outline of toner replenishment to the developing container 3 of the developing device 5 in this embodiment will be described.

[0035] A main body opening 121, which is an opening of a main body housing 120, is provided at the front end, which is one end of the image forming apparatus 100 in the second direction. A front door 130 is also provided on the main body housing 120 as an opening / closing member for opening and closing the main body opening 121. A cartridge holder 140 is provided between the process unit P and the main body opening 121 in the second direction. Toner cartridges (herein also simply referred to as "cartridges") 200Y, 200M, 200C, and 200K, which are toner containers for replenishing yellow, magenta, cyan, and black, respectively, are removably mounted to the cartridge holder 140. Thus, the cartridges 200Y, 200M, 200C, and 200K are removably mounted to the apparatus main body 110 of the image forming apparatus 100. The cartridges 200Y, 200M, 200C, and 200K contain yellow, magenta, cyan, and black toner, respectively. Toner is supplied from cartridges 200Y, 200M, 200C, and 200K to developing containers 3Y, 3M, 3C, and 3K of developing devices 5Y, 5M, 5C, and 5K, respectively. Here, the portion of image forming apparatus 100 excluding cartridges 200Y, 200M, 200C, and 200K is referred to as "apparatus main body 110."

[0036] Fig. 2 is a perspective view of image forming apparatus 100 with front door 130 closed. Fig. 3 is a perspective view of image forming apparatus 100 with front door 130 open. Fig. 4 is a perspective view of image forming apparatus 100 with front door 130 open and cyan cartridge 200C removed from cartridge holder 140.

[0037] The front door 130 is configured to be movable between a closed position (FIG. 2) where the main body opening 121 is closed and an open position (FIGS. 3 and 4) where the main body opening 121 is open. In this embodiment, the front door 130 is configured to be movable between the closed position and the open position by rotating about a rotation axis located at the lower end and substantially parallel to the first direction. As shown in FIGS. 3 and 4, an operator can access the cartridge 200 by opening the front door 130. In this manner, the cartridge 200 is detachably mounted to the apparatus main body 110 at the front end, which is one end of the image forming apparatus 100 in the second direction. In other words, the cartridge 200 is provided at the end of the image forming apparatus 100 on the downstream side in the discharge direction of the recording material S by the discharge roller 60.

[0038] As shown in FIG. 4, cartridge 200 is configured to be detachable from cartridge holder 140 by being moved along the second direction. This allows an operator to replenish toner in process unit P without removing process unit P from apparatus main body 110. Furthermore, by arranging cartridge 200 at the end on the front side of image forming apparatus 100, an operator can access cartridge 200 from the front side of image forming apparatus 100, just as when collecting recording material S discharged to discharge tray 70. Furthermore, as shown in FIG. 4, since cartridge holder 140 is provided at the end on the front side of image forming apparatus 100, process unit P is not substantially exposed to the outside of image forming apparatus 100 even after cartridge 200 is removed. Cartridge 200 is stored in apparatus main body 110 when front door 130 is closed.

[0039] The cartridge holder 140 may be provided with a holding means for removably holding the cartridge 200. As the holding means, any means can be used, such as a configuration in which at least a part of the cartridge 200 is held by being press-fitted into a holding portion, or a configuration in which at least a part of the cartridge 200 is locked by an elastically deformable locking portion.

[0040] <Toner cartridge placement> Next, the arrangement of cartridges 200Y, 200M, 200C, and 200K will be described with reference to Figures 3 to 5. Figure 5 is a front view of cartridges 200Y, 200M, 200C, and 200K (image forming units 500, described later) attached to cartridge holder 140, viewed from the front side in a second direction.

[0041] Image forming apparatus 100 has cartridges 200Y, 200M, 200C, and 200K that are detachable from apparatus main body 110. Cartridges 200Y, 200M, 200C, and 200K are arranged at the end of the front side of image forming apparatus 100 in the second direction.

[0042] Furthermore, each of the cartridges 200Y, 200M, 200C, and 200K is arranged such that at least one end (one end in this embodiment) in the first direction is adjacent to any end of the image forming apparatus 100 in the first direction. In other words, each of the cartridges 200Y, 200M, 200C, and 200K has only one end in the first direction adjacent to another cartridge 200.

[0043] The yellow cartridge 200Y and the magenta cartridge 200M are arranged so as to be stacked in the third direction. Here, "one cartridge 200 (or a predetermined area thereof) and another cartridge 200 (or a predetermined area thereof) being arranged so as to be stacked in the third direction" means, in more detail, the following. That is, when viewed in the third direction, at least a portion of one cartridge 200 (or a predetermined area thereof) overlaps with at least a portion of the other cartridge 200 (or a predetermined area thereof). In this embodiment, the yellow cartridge 200Y and the magenta cartridge 200M are arranged side by side in the third direction and adjacent to each other. In this embodiment, the yellow cartridge 200Y is arranged on the upper side, and the magenta cartridge is arranged on the lower side. Similarly, the cyan cartridge 200C and the black cartridge 200K are arranged so as to be stacked in the third direction. In this embodiment, the cyan cartridge 200C and the black cartridge 200K are arranged side by side in the third direction and adjacent to each other. In this embodiment, the cyan cartridge 200C is disposed on the upper side, and the black cartridge 200K is disposed on the lower side.

[0044] Furthermore, the yellow cartridge 200Y and the cyan cartridge 200C are arranged so as to be stacked in the first direction. Here, "one cartridge 200 (or a predetermined area thereof) and another cartridge 200 (or a predetermined area thereof) being arranged so as to be stacked in the first direction" means, in more detail, the following. That is, when viewed in the first direction, at least a portion of the one cartridge 200 (or a predetermined area thereof) overlaps with at least a portion of the other cartridge 200 (or a predetermined area thereof). In this embodiment, the yellow cartridge 200Y and the cyan cartridge 200C are arranged side by side in the first direction and adjacent to each other. In this embodiment, the yellow cartridge 200Y is arranged on the left side, and the cyan cartridge 200C is arranged on the right side. Similarly, the magenta cartridge 200M and the black cartridge 200K are arranged so as to be stacked in the first direction. In this embodiment, the magenta cartridge 200M and the black cartridge 200K are arranged side by side in the first direction and adjacent to each other. In this embodiment, the magenta cartridge 200M is disposed on the left side, and the black cartridge 200K is disposed on the right side.

[0045] As described above, in this embodiment, the yellow cartridge 200Y and the magenta cartridge 200M are disposed closer to the end on the left side of the image forming apparatus 100 in the first direction. Furthermore, the cyan cartridge 200C and the black cartridge 200K are disposed closer to the end on the right side of the image forming apparatus 100 in the first direction. That is, in this embodiment, the yellow cartridge 200Y and the magenta cartridge 200M are disposed closer to the end on the left side (first end) of the image forming apparatus 100 than to the end on the right side (second end) of the image forming apparatus 100 in the first direction. Furthermore, the cyan cartridge 200C and the black cartridge 200K are disposed closer to the end on the right side (second end) of the image forming apparatus 100 than to the end on the left side (first end) of the image forming apparatus 100 in the first direction.

[0046] In particular, in this embodiment, the cartridges 200Y, 200M, 200C, and 200K have approximately the same outer shape. In this embodiment, the cartridge 200 has a substantially rectangular parallelepiped shape that is long in the first direction when attached to the apparatus main body 110. When attached to the apparatus main body 110, the cartridge 200 has a side extending along the second direction (substantially parallel in this embodiment), a side extending along the first direction (substantially parallel in this embodiment), and a side extending along the third direction (substantially parallel in this embodiment). The yellow cartridge 200Y and the magenta cartridge 200M are aligned along the third direction (substantially parallel in this embodiment). In this embodiment, when viewed in the third direction, the yellow cartridge 200Y and the magenta cartridge 200M overlap each other almost entirely. Similarly, the cyan cartridge 200C and the black cartridge 200K are aligned along the third direction (substantially parallel in this embodiment). In this embodiment, when viewed in the third direction, the cyan cartridge 200C and the black cartridge 200K overlap each other substantially entirely. Furthermore, the yellow cartridge 200Y and the cyan cartridge 200C are aligned along the first direction (substantially parallel in this embodiment). In this embodiment, when viewed in the first direction, the yellow cartridge 200Y and the cyan cartridge 200C overlap each other substantially entirely. Similarly, the magenta cartridge 200M and the black cartridge 200K are aligned along the first direction (substantially parallel in this embodiment). In this embodiment, when viewed in the first direction, the magenta cartridge 200M and the black cartridge 200K overlap each other substantially entirely.

[0047] Cartridges 200Y, 200M, 200C, and 200K are provided with outlets 201Y, 201M, 201C, and 201K, respectively, for discharging toner. Outlet 201 is provided at an end of cartridge 200 in the first direction, adjacent to an end of image forming apparatus 100 in the first direction (FIG. 5). The arrangement of outlet 201 will be described in detail later.

[0048] In this embodiment, the cartridges 200Y, 200M, 200C, and 200K of the respective colors of yellow, magenta, cyan, and black are arranged in the color arrangement described above, but the color arrangement may be different from that in this embodiment.

[0049] <Toner transport path> Next, a toner transport path (toner supply path) from the cartridge 200 to the developing container 3 will be described with reference to FIGS.

[0050] Here, a unit including the process units PY, PM, PC, PK, cartridge holder 140, cartridges 200Y, 200M, 200C, 200K, and a supply mechanism 300 (described later) is referred to as an image forming unit 500. The supply mechanism 300 is configured to include supply pipes 310 (310Y, 310M, 310C, 310K) (FIGS. 6 to 10) and conveying devices 320 (320Y, 320M, 320C, 320K) (FIG. 12) (described later).

[0051] FIG. 6 is a perspective view of the image forming unit 500 with cartridges 200Y, 200M, 200C, and 200K attached. FIG. 7 is a perspective view of the image forming unit 500 with cartridges 200Y, 200M, 200C, and 200K removed. FIG. 8 is a top view of the laser scanner unit 8 and the image forming unit 500 viewed from above in a third direction. FIG. 9 is a top view of the image forming unit 500 viewed from above in a third direction, illustrating the optical paths LY, LM, LC, and LK of the laser light traveling from the laser scanner unit 8 toward the photosensitive drums 1Y, 1M, 1C, and 1K. FIG. 10 is a side view of the laser scanner unit 8 and the image forming unit 500 viewed from the left side in a first direction.

[0052] As shown in Fig. 7, the cartridge holder 140 is provided with receiving openings 141Y, 141M, 141C, and 141K for receiving toner discharged from discharge openings 201Y, 201M, 201C, and 201K provided in the cartridges 200Y, 200M, 200C, and 200K, respectively. The front end of the receiving opening 141 is located on a side surface 144 (Fig. 7) on the front side of the cartridge holder 140. The rear end of the receiving opening 141 is located on a side surface 142 (Figs. 9 and 10) on the rear side of the cartridge holder 140. Two receiving openings 141 are provided on each of the left and right side surfaces.

[0053] Replenishment pipes 310Y, 310M, 310C, and 310K are provided within the main body housing 120 as passages through which toner passes from cartridges 200Y, 200M, 200C, and 200K toward developing containers 3Y, 3M, 3C, and 3K, respectively. Replenishment pipe 310 constitutes a toner transport path from cartridge 200 to developing container 3. The end of replenishing pipe 310 on the cartridge 200 side (discharge port 201 side) is referred to as upstream end 311 (311Y, 311M, 311C, and 311K). The end of replenishing pipe 310 on the developing container 3 side is referred to as downstream end 312 (312Y, 312M, 312C, and 312K).

[0054] Upstream ends 311Y, 311M, 311C, and 311K of supply pipes 310Y, 310M, 310C, and 310K are connected to the rear end of the inlet 141Y, 141M, 141C, and 141K, respectively. This allows communication between the inlet 141 and the inside of the supply pipe 310 to allow the movement of toner. Furthermore, when the cartridges 200Y, 200M, 200C, and 200K are attached to predetermined positions in the cartridge holder 140, the discharge ports 201Y, 201M, 201C, and 201K are connected to the inlet 141Y, 141M, 141C, and 141K, respectively. This allows communication between the inside of the cartridge 200 and the inside of the supply pipe 310 via the discharge port 201 and the inlet 141 to allow the movement of toner. Downstream ends 312Y, 312M, 312C, and 312K of the supply pipes 310Y, 310M, 310C, and 310K are connected to the developer containers 3Y, 3M, 3C, and 3K, respectively, so that the inside of the developer container 3 and the inside of the supply pipe 310 communicate with each other to allow the movement of toner.

[0055] Note that the discharge outlet 201 and the inlet 141 can be connected by any connecting means as long as it can sufficiently prevent toner from leaking from between them. For example, a configuration in which either the discharge outlet 201 or the inlet 141 is inserted into the other, or a configuration in which the end faces constituting the edges of the discharge outlet 201 and the inlet 141 abut against each other can be used. Also, a sealing member may be provided to prevent toner from leaking from the connection between the discharge outlet 201 and the inlet 141.

[0056] The toner discharged from the inside of cartridge 200 through discharge port 121 and received by receiving port 141 is moved inside supply pipe 310 from upstream end 311 to downstream end 444, and is replenished into the inside of developing container 3. As a conveying means for conveying toner from cartridge 200 to developing container 3 through supply pipe 310, a configuration in which toner is conveyed together with air using a pump, a configuration in which a screw is used, a configuration in which a belt conveyor is used, or the like can be used. An example of this conveying means will be described later.

[0057] <Location of supply pipes and discharge ports> Next, the arrangement of supply pipes 310Y, 310M, 310C, and 310K and discharge ports 201Y, 201M, 201C, and 201K will be described with reference to Figures 6 to 11. Figure 11 is a schematic diagram for explaining the positional relationship between the optical path L (LY, LM, LC, and LK) of the laser light and the discharge port 201 (or the upstream end 311 of supply pipe 310) when viewed in the second direction (only one end side of the optical path L in the first direction is shown).

[0058] The supply pipes 310Y, 310M, 310C, and 310K are arranged to avoid the optical paths LY, LM, LC, and LK so as not to block the optical paths LY, LM, LC, and LK of the laser light irradiated from the laser scanner unit 8 to the photosensitive drums 1Y, 1M, 1C, and 1K during image formation. In this embodiment, the supply pipes 310Y, 310M, 310C, and 310K (particularly, at least a portion including the upstream ends 311Y, 311M, 311C, and 311K) are arranged so as not to overlap any of the optical paths LY, LM, LC, and LK when viewed in the second direction. Here, in this embodiment, as shown in FIG. 9 , the width of the optical path L of the laser light irradiated from the laser scanner unit 8 to the photosensitive drum 1 increases in the first direction from the exposure window 7 of the laser scanner unit 8 toward the photosensitive drum 1. In such a configuration, as shown in FIGS. 9 and 11(a), at least a portion of the supply pipe 310 (upstream end 311) may be located within the range LW of the optical path L in the first direction. Even in this case, if the supply pipe 310 does not overlap with the optical path L when viewed in the second direction, the supply pipe 310 can be prevented from blocking the optical path L and the toner transport path can be simplified. Furthermore, such a configuration is advantageous for reducing the size of the image forming apparatus 100 in the first direction. However, as shown in FIG. 11(b), the supply pipe 310 may be located outside the range LW of the optical path L in the first direction.

[0059] In this embodiment, two supply pipes 310 are arranged on each of the left and right sides of the optical paths LY, LM, LC, and LK in the first direction. That is, the yellow supply pipe 310Y and the magenta supply pipe 310M are arranged on the left side, and the cyan supply pipe 310C and the black supply pipe 310K are arranged on the right side. Furthermore, the yellow supply pipe 310Y and the magenta supply pipe 310M are configured such that at least a portion of the yellow supply pipe 310Y and at least a portion of the magenta supply pipe 310M overlap when viewed in the third direction. In this embodiment, the yellow supply pipe 310Y and the magenta supply pipe 310M are configured such that at least a portion of each pipe overlaps, including the upstream ends 311Y and 311M, when viewed in the third direction. Similarly, the cyan supply pipe 310C and the black supply pipe 310K are configured such that at least a portion of the cyan supply pipe 310C overlaps with at least a portion of the black supply pipe 310K when viewed in the third direction. In this embodiment, the cyan supply pipe 310C and the black supply pipe 310K are configured such that at least a portion of the cyan supply pipe 310C and the black supply pipe 310K, including their respective upstream ends 311C and 311K, overlap with each other when viewed in the third direction.

[0060] In this manner, in this embodiment, at least a portion including the upstream end 311 of the supply pipe 310 connected to the cartridge holder 140, two pairs of supply pipes 310 are configured to overlap when viewed in the third direction. Also, in this embodiment, at least a portion including the upstream end 311 of the supply pipes 310Y, 310M, 310C, and 310K extends in a substantially straight line from the cartridge holder 140 at a position that avoids the optical path L as described above.

[0061] 8 and 10, the supply pipes 310Y, 310M, 310C, and 310K are disposed below the laser scanner unit 8. Furthermore, in this embodiment, the supply pipes 310Y, 310M, 310C, and 310K are disposed above the photosensitive drums 1Y, 1M, 1C, and 4K. Furthermore, in this embodiment, the two supply pipes 310Y and 310M disposed on the left side and the two supply pipes 310C and 310K disposed on the right side are disposed above and below each other. However, as long as the optical paths LY, LM, LC, and LK and other peripheral components are avoided, the multiple supply pipes 310 disposed on the left or right side may be configured to at least partially overlap each other.

[0062] In order to enable the above-described arrangement of the supply pipes 310Y, 310M, 310C, and 310K, the discharge ports 201Y, 201M, 201C, and 201K of the cartridges 200Y, 200M, 200C, and 200K are arranged as follows: That is, the discharge ports 201Y, 201M, 201C, and 201K are each provided at an end of the cartridge 200 in the first direction that is adjacent to an end of the image forming apparatus 100 in the first direction (FIG. 5). In particular, in this embodiment, the discharge ports 201Y, 201M, 201C, and 201K are each arranged so as not to overlap any of the optical paths LY, LM, LC, and LK when viewed in the second direction (FIGS. 9 and 11). As in the case of the supply pipe 310 (upstream end 311), at least a portion of the outlet 201 may be located within the range LW of the optical path L in the first direction as shown in Figure 11(a), or the outlet 201 may be located outside the range LW of the optical path L in the first direction as shown in Figure 11(b).

[0063] In this embodiment, the yellow cartridge 200Y and the magenta cartridge 200M are arranged overlapping in the third direction, with their left side edges in the first direction disposed adjacent to the left side edge of the image forming device 100. Therefore, the ejection ports 201Y and 201M of the cartridges 200Y and 200M can be arranged at the left side edge of the cartridges 200Y and 200M adjacent to the left side edge of the image forming device 100 in the first direction (FIG. 5). Also, in this embodiment, the cyan cartridge 200C and the black cartridge 200K are arranged overlapping in the third direction, with their right side edge in the first direction disposed adjacent to the right side edge of the image forming device 100. Therefore, the ejection ports 201C and 201K of the cartridges 200C and 200K can be arranged at the right side edge of the cartridges 200C and 200K adjacent to the right side edge of the image forming device 100 in the first direction (FIG. 5). In this manner, in this embodiment, two outlets 201 are provided on each of the left and right side surfaces.

[0064] Here, as described in Patent Document 1, if four cartridges 200Y, 200M, 200C, and 200K are aligned in the first direction, the following occurs: For at least two cartridges 200 that are not adjacent to the end of image forming apparatus 100 but are arranged inside image forming apparatus 100, it is necessary to detour supply pipe 310 from upstream end 311 to the outside of the optical path once in order to avoid optical paths LY, LM, LC, and LK.

[0065] In contrast, in this embodiment, one end of each of cartridges 200Y, 200M, 200C, and 200K in the first direction is disposed adjacent to one end of image forming apparatus 100 in the first direction. Therefore, as shown in FIGS. 9 and 11, it is possible to dispose upstream end 311 of replenishing pipe 310 in a position that does not overlap with optical path L when viewed in the second direction. Therefore, according to this embodiment, the toner transport path from cartridge 200 to developer container 3 can be simplified. Therefore, by effectively utilizing the space within image forming apparatus 100, it is possible to reduce the size of image forming apparatus 100 and increase the capacity of cartridge 200.

[0066] In this embodiment, the upstream end 311 of the supply pipe 310 is disposed on a side surface 142 (FIGS. 9 and 10) on the rear side of the cartridge holder 140, but it may also be disposed on a side surface 143 (FIG. 5) on the left or right side of the cartridge holder 140 in the first direction. In this case, the receiving port 141 and the discharge port 201 may be disposed on the left or right side in accordance with the position of the upstream end 311 of the supply pipe 310.

[0067] <Transportation means> Next, an example of a conveying device as a conveying means that conveys toner from cartridge 200 to developer container 3 through replenishing pipe 310 will be described. Fig. 12(a) is a perspective view of image forming unit 500 with cartridge 200 attached, for explaining an example of conveying device 320 (320Y, 320M, 320C, 320K). Fig. 12(b) is a front view of image forming unit 500 with cartridge 200 attached, viewed from the front side in a second direction, for explaining an example of conveying device 320.

[0068] The conveying device 320 in this example is a pressure-feeding type conveying device. The conveying devices 320Y, 320M, 320C, and 320K for yellow, magenta, cyan, and black have the same configuration and operation. In this example, the conveying device 320 is configured with diaphragm pumps 321 (321Y, 321M, 321C, and 321K). The diaphragm pumps 321 may be any available configuration, such as known pumps. In this example, the diaphragm pumps 321 are attached to the cartridge holder 140. The diaphragm pumps 321 include motor units 322 (322Y, 322M, 322C, and 322K) and diaphragm units 323 (323Y, 323M, 323C, and 323K). The diaphragm unit 323 is provided with an intake port (not shown) for drawing in air and exhaust ports 324 (324Y, 324M, 324C, 324K) for exhausting air. The exhaust ports 324 extend into the area of ​​the cartridge holder 140 where the cartridge 200 is attached. Note that an air flow path such as a tube may be connected to the exhaust port 324 of the diaphragm pump 321, and the exhaust port 324 may be extended to an appropriate position in the cartridge holder 140. Furthermore, a groove (recess) or the like may be provided in the cartridge 200 as appropriate to avoid the tube or the like.

[0069] The cartridge 200 is provided with air receiving ports 202 (202Y, 202M, 202C, 202K) for receiving air discharged from the discharge port 324 into the interior of the cartridge 200. When the cartridge 200 is attached to a predetermined position in the cartridge holder 140, the discharge port 324 and the air receiving ports 202 are connected. In order to efficiently discharge the toner inside the cartridge 200 from the discharge port 201, it is preferable that the air receiving ports 202 are provided at the end opposite the discharge port 201 in the first direction.

[0070] When toner is transported from the cartridge 200 to the developing container 3 through the supply pipe 310, the diaphragm pump 321 is driven, and air is discharged from the discharge port 324. The operating principle of the diaphragm pump 321 is well known, so a detailed description will be omitted. For example, an eccentric shaft connected to the output shaft of the motor unit 322 moves the diaphragm (membrane) of the diaphragm unit 323, changing the internal pressure of the diaphragm unit 323. The diaphragm unit 323 is provided with a valve for opening and closing the suction port and a valve for opening and closing the discharge port 324. These valves open and close in response to changes in the internal pressure of the diaphragm unit 323, and air sucked in through the suction port is discharged from the discharge port 324. This air is received (sent) into the cartridge 200 through the air inlet 202. As a result, toner is discharged from the outlet 201 together with the air, and the toner is replenished to the developing container 3 through the supply pipe 310. The developing container 3 may be provided with an exhaust port for discharging air through a filter that prevents toner from flowing out.

[0071] Here, toner replenishment from the cartridge 200 to the developing container 3 may be performed all at once, for example, when the toner in the developing container 3 is depleted, or may be performed successively as the toner in the developing container 3 decreases. In addition, when toner replenishment is performed all at once, the cartridge 200 may be removed from the apparatus main body 110 after the toner replenishment is completed, and image formation may be performed in that state.

[0072] As described above, the conveying means for conveying toner from the cartridge 200 to the developing container 3 is not limited to a configuration in which a pump is used to convey toner together with air. For example, a configuration using a screw or a configuration using a belt conveyor may be used. For example, a screw may be provided inside the cartridge 200 to discharge toner from the discharge port 201. Furthermore, for example, a screw may be provided inside the supply pipe 310 to convey toner from the upstream end 311 to the downstream end 311 of the supply pipe 310. In a configuration using a screw, the drive source for rotating the screw may be a motor of a drive unit that drives the photosensitive drum 1 or the intermediate transfer belt 11, or a dedicated motor may be provided. Furthermore, the above-mentioned different conveying means may be used in appropriate combination.

[0073] As described above, according to this embodiment, it is possible to simplify the toner transport path from the cartridge 200 to the developing container 3. Therefore, by effectively utilizing the space inside the image forming apparatus 100, it is possible to reduce the size of the image forming apparatus 100 and increase the capacity of the cartridge 200.

[0074] The process units P may be attached to the main body housing 120 so that they cannot be easily attached or detached. Alternatively, the process units P may be detachable from the apparatus main body 110. In this case, the four process units P may be individually detachable from the apparatus main body 110, or a plurality of (or all of) the process units P may be detachable from the apparatus main body 110 as a whole. Furthermore, the image forming unit 500 may be detachable from the apparatus main body 110 as a whole.

[0075] In this embodiment, cartridges 200Y, 200M, 200C, and 200K are arranged so as not to overlap with process units PY, PM, PC, and PK in the second direction. Here, not overlapping with process unit P means not overlapping with elements constituting process unit P, typically the developing container 3 and drum unit frame 61 that form the outer shape of process unit P. However, for example, at least a portion of at least one cartridge 200 may be arranged so as to overlap with at least a portion of process cartridge P (for example, the process unit P located closest to the main body opening 121 in the second direction) in the second direction.

[0076] [Example 2] Next, another embodiment of the present invention will be described. The basic configuration and operation of the image forming apparatus of this embodiment are the same as those of embodiment 1. Therefore, in the image forming apparatus of this embodiment, elements having the same or corresponding functions or configurations as those of the image forming apparatus of embodiment 1 are assigned the same reference numerals as those of embodiment 1, and detailed descriptions thereof will be omitted.

[0077] Figure 13(a) is a front view of the image forming unit 500 in this embodiment, viewed from the front side in the second direction, and Figure 13(b) is a perspective view of the image forming unit 500 in this embodiment.

[0078] In this embodiment, cartridges 200Y, 200M, 200C, and 200K are arranged stacked in the third direction. Also, in this embodiment, both end portions in the first direction of cartridges 200Y, 200M, 200C, and 200K are arranged adjacent to ends of image forming apparatus 100 in the first direction. In other words, cartridges 200Y, 200M, 200C, and 200K extend in the first direction from a position adjacent to one end of image forming apparatus 100 to a position adjacent to the other end. In particular, in this embodiment, cartridges 200Y, 200M, 200C, and 200K have substantially the same outer shape (a substantially rectangular parallelepiped shape that is long in the first direction). In this embodiment, the cartridges 200Y, 200M, 200C, and 200K of each color, yellow, magenta, cyan, and black, are aligned in this order from top to bottom along the third direction (approximately parallel in this embodiment).

[0079] The ejection openings 201Y, 201M, 201C, and 201K are each provided at an end of the cartridge 200 in the first direction that is adjacent to an end of the image forming apparatus 100 in the first direction. In particular, in this embodiment, the ejection openings 201Y, 201M, 201C, and 201K are each arranged so as not to overlap with any of the optical paths LY, LM, LC, and LK when viewed in the second direction. In this embodiment, the ejection openings 201Y and 201M of the yellow and magenta cartridges 200Y and 200M are each arranged at an end on the left side surface of the cartridge 200Y and 200M that is adjacent to an end on the left side surface of the image forming apparatus 100 in the first direction. In this embodiment, the discharge ports 201C and 201K of the cyan and black cartridges 200C and 200K are disposed at the end of the right side surface of the cartridges 200C and 200K, respectively, adjacent to the end of the right side surface of the image forming apparatus 100 in the first direction. In this embodiment, both end portions of each of the cartridges 200Y, 200M, 200C, and 200K in the first direction are adjacent to the ends of the image forming apparatus 100 in the first direction. Therefore, the discharge ports 201Y, 201M, 201C, and 201K (and the supply pipes 310Y, 310M, 310C, and 310K) can be disposed arbitrarily on either the left side surface or the right side surface in the first direction.

[0080] In the configuration of this embodiment, the cartridge 200 is thinner in the third direction and longer in the first direction than in Embodiment 1. In this embodiment, the length of the cartridge 200 in the first direction can be increased, so that when the toner in the cartridge 200 is transported toward the discharge port 201 using a screw or the like, the toner can be easily transported.

[0081] In this embodiment, the cartridges 200Y, 200M, 200C, and 200K of the respective colors of yellow, magenta, cyan, and black are arranged in the color arrangement described above, but the color arrangement may be different from that in this embodiment.

[0082] Furthermore, in this embodiment, the upstream end 311 of the supply pipe 310 is disposed on the side surface 142 on the rear side of the cartridge holder 140, but it may also be disposed on the side surface 143 on the left or right side of the cartridge holder 140 in the first direction. In this case, the receiving port 141 and the discharge port 201 may be disposed on the left or right side in accordance with the position of the upstream end 311 of the supply pipe 310.

[0083] As described above, according to this embodiment, the same effects as those of the first embodiment can be obtained, and the use of a screw or the like as a toner conveying means in the cartridge 200 becomes easier.

[0084] [Example 3] Next, another embodiment of the present invention will be described. The basic configuration and operation of the image forming apparatus of this embodiment are the same as those of embodiment 1. Therefore, in the image forming apparatus of this embodiment, elements having the same or corresponding functions or configurations as those of the image forming apparatus of embodiment 1 are assigned the same reference numerals as those of embodiment 1, and detailed descriptions thereof will be omitted.

[0085] Figure 14(a) is a front view of the image forming unit 500 in this embodiment, viewed from the front side in the second direction, and Figure 14(b) is a perspective view of the image forming unit 500 in this embodiment.

[0086] In this embodiment, the arrangement of the cartridges 200Y, 200M, 200C, and 200K and the arrangement of the discharge ports 201Y, 201M, 201C, and 201K are generally similar to those in the first embodiment.

[0087] In this embodiment, when viewed in the second direction, the yellow cartridge 200Y and the magenta cartridge 200M are arranged to overlap in the third direction so that their L-shaped portions fit together.

[0088] More specifically, the yellow cartridge 200Y has a first region A1 and a second region A2 in the first direction. In the third direction, the width of the first region A1 is a first width W1, and the width of the second region A2 is a second width W2 that is larger than the first width W1. The magenta cartridge 200M has a third region A3 and a fourth region A4 in the first direction. In the third direction, the width of the third region A3 is a third width W3, and the width of the fourth region A4 is a fourth width A4 that is smaller than the third width W3. In this embodiment, the first width W1 and the fourth width W4 are approximately equal, and the second width W2 and the third width W3 are approximately equal, but they may be different. The yellow cartridge 200Y and the magenta cartridge 200M are arranged as follows: That is, when viewed in the third direction, at least a portion (in this embodiment, substantially the entirety) of the first region A1 overlaps with at least a portion (in this embodiment, substantially the entirety) of the third region A3. Also, when viewed in the third direction, at least a portion (in this embodiment, substantially the entirety) of the second region A2 overlaps with at least a portion (in this embodiment, substantially the entirety) of the fourth region A4. Furthermore, when viewed in the second direction, at least a portion (in this embodiment, substantially half of the second region A2) overlaps with at least a portion (in this embodiment, substantially half of the third direction) of the third region A3. Also, in the yellow cartridge 200Y, a discharge port 201Y is provided in the first region A1, and in the magenta cartridge 200M, a discharge port 201M is provided in the third region A3.

[0089] Similarly, in this embodiment, when viewed in the second direction, the cyan cartridge 200C and the black cartridge 200K are stacked in the third direction so that their L-shaped shapes interlock with each other. In the cyan and black cartridges 200C and 200K, regions with the same widths (W1 to W4) as those in the yellow and magenta cartridges 200Y and 200M are designated as first region A1 to fourth region A4. Furthermore, the cyan cartridge 200C has an outlet 201C in the first region A1, while the black cartridge 200K has an outlet 201K in the third region A3. However, the shapes and arrangement of the outlets 201 between the yellow cartridge 200Y and the cyan cartridge 200C are substantially symmetrical with respect to planes parallel to both the second and third directions. Similarly, the shapes and arrangements of the discharge ports 201 of the magenta cartridge 200M and the black cartridge 200K are substantially symmetrical with respect to a plane parallel to both the second direction and the third direction.

[0090] Therefore, in the configuration of this embodiment, the cartridges 200 of each color cannot be attached to locations of different colors due to a combination of the shape of the cartridges 200 and the arrangement of the outlets 201 provided in the cartridges 200. Therefore, the configuration of this embodiment is advantageous from the viewpoint of preventing erroneous attachment of the cartridges 200.

[0091] In this embodiment, the cartridges 200Y, 200M, 200C, and 200K of the respective colors of yellow, magenta, cyan, and black are arranged in the color arrangement described above, but the color arrangement may be different from that in this embodiment.

[0092] Furthermore, similar to the above-described embodiments, the upstream end 311 of the supply pipe 310, the inlet 141, and the outlet 201 may be disposed on the left or right side surface 143 of the cartridge holder 140 in the first direction.

[0093] As described above, according to this embodiment, the same effects as those of the first embodiment can be obtained, and also, the effect of easily preventing erroneous installation of the cartridge 200 can be obtained.

[0094] [Example 4] Next, another embodiment of the present invention will be described. The basic configuration and operation of the image forming apparatus of this embodiment are the same as those of embodiment 1. Therefore, in the image forming apparatus of this embodiment, elements having the same or corresponding functions or configurations as those of the image forming apparatus of embodiment 1 are assigned the same reference numerals as those of embodiment 1, and detailed descriptions thereof will be omitted.

[0095] Figure 15(a) is a front view of the image forming unit 500 in this embodiment, viewed from the front side in the second direction, and Figure 15(b) is a perspective view of the image forming unit 500 in this embodiment.

[0096] In this embodiment, similar to the third embodiment, the cartridge 200 has an advantageous shape from the viewpoint of preventing incorrect installation. In this embodiment, when viewed in the second direction, the yellow cartridge 200Y and the magenta cartridge 200M are stacked and arranged in the third direction so that their concave and convex shapes fit together.

[0097] More specifically, the yellow cartridge 200Y has the same first and second regions A1 and A2 as those in Example 3, but also a fifth region A5 located on the opposite side of the second region A2 from the first region A1 in the first direction. In the third direction, the width of the fifth region A5 is a fifth width W5 that is smaller than the second width W2. In this example, the fifth width W5 is approximately the same as the first width W1, but may be different. The magenta cartridge 200M has the same third and fourth regions A3 and A4 as those in Example 3, but also a sixth region A6 located on the opposite side of the fourth region A4 from the third region A3 in the first direction. In the third direction, the width of the sixth region W6 is a sixth width W6 that is larger than the fourth width W4. In this example, the sixth width W6 is approximately the same as the third width W3, but may be different.

[0098] The yellow cartridge 200Y and the magenta cartridge 200M are arranged as follows: That is, as in Example 3, when viewed in the third direction, at least a portion (in this example, substantially the entirety) of the first region A1 overlaps with at least a portion (in this example, substantially the entirety) of the third region A3. When viewed in the third direction, at least a portion (in this example, substantially the entirety) of the second region A2 overlaps with at least a portion (in this example, substantially the entirety) of the fourth region A4. When viewed in the second direction, at least a portion (in this example, substantially half of the second region A2 overlaps with at least a portion (in this example, substantially half of the third direction). Furthermore, in this example, when viewed in the third direction, at least a portion (in this example, substantially the entirety) of the fifth region A5 overlaps with at least a portion (in this example, substantially the entirety) of the sixth region A6. When viewed in the second direction, at least a portion of the second region A2 (approximately half in the third direction in this embodiment) overlaps with at least a portion of the sixth region (approximately half in the third direction in this embodiment).

[0099] In addition, the yellow cartridge 200Y has a discharge port 201Y provided in the first area A1, and the magenta cartridge 200M has a discharge port 201M provided in the third area A3.

[0100] Similarly, in this embodiment, when viewed in the second direction, the cyan cartridge 200C and the black cartridge 200K are stacked in the third direction so that their concave and convex shapes interlock with each other. In the cyan and black cartridges 200C and 200K, regions with the same widths (W1 to W6) as those in the yellow and magenta cartridges 200Y and 200M are designated as the first region A1 to the sixth region A6. The cyan cartridge 200C has an outlet 201C in the first region A1, while the black cartridge 200K has an outlet 201K in the third region A3. However, the shapes and arrangement of the outlets 201 between the yellow cartridge 200Y and the cyan cartridge 200C are substantially symmetrical with respect to planes parallel to both the second and third directions. Similarly, the shapes and arrangements of the discharge ports 201 of the magenta cartridge 200M and the black cartridge 200K are substantially symmetrical with respect to a plane parallel to both the second direction and the third direction.

[0101] Therefore, in the configuration of this embodiment, as in the third embodiment, the cartridges 200 of each color cannot be attached to a location of a different color due to the combination of the shape of the cartridges 200 and the arrangement of the outlets 201 provided in the cartridges 200. This is advantageous from the viewpoint of preventing erroneous attachment of the cartridges 200.

[0102] In this embodiment, the cartridges 200Y, 200M, 200C, and 200K of the respective colors of yellow, magenta, cyan, and black are arranged in the color arrangement described above, but the color arrangement may be different from that in this embodiment.

[0103] Furthermore, similar to the above-described embodiments, the upstream end 311 of the supply pipe 310, the inlet 141, and the outlet 201 may be disposed on the left or right side surface 143 of the cartridge holder 140 in the first direction.

[0104] As described above, according to this embodiment, the same effects as those of the first embodiment can be obtained, and also, like the third embodiment, the effect of easily preventing erroneous installation of the cartridge 200 can be obtained.

[0105] [Example 5] Next, another embodiment of the present invention will be described. The basic configuration and operation of the image forming apparatus of this embodiment are the same as those of embodiment 1. Therefore, in the image forming apparatus of this embodiment, elements having the same or corresponding functions or configurations as those of the image forming apparatus of embodiment 1 are assigned the same reference numerals as those of embodiment 1, and detailed descriptions thereof will be omitted.

[0106] Figure 16(a) is a front view of the image forming unit 500 in this embodiment, viewed from the front side in the second direction, and Figure 16(b) is a perspective view of the image forming unit 500 in this embodiment.

[0107] In this embodiment, the yellow cartridge 200Y, the magenta cartridge 200M, and the cyan cartridge 200C are stacked and arranged in the third direction. These cartridges 200Y, 200M, and 200C are arranged closer to the left side edge of the image forming apparatus 100 in the first direction. That is, in this embodiment, the yellow, magenta, and cyan cartridges 200Y, 200M, and 200C are arranged closer to the left side edge (first edge) of the image forming apparatus 100 than to the right side edge (second edge) of the image forming apparatus 100 in the first direction. In this embodiment, the yellow, magenta, and cyan cartridges 200Y, 200M, and 200C are aligned in this order from top to bottom along the third direction (approximately parallel in this embodiment). The black cartridge 200K is arranged on the opposite side of the other color cartridges 200Y, 200M, and 200C in the first direction. In other words, the black cartridge 200K is disposed closer to the right end of the image forming apparatus 100 in the first direction. That is, in this embodiment, the black cartridge 200K is disposed closer to the right end (second end) of the image forming apparatus 100 than to the left end (first end) of the image forming apparatus 100 in the first direction. The yellow, magenta, and cyan cartridges 200Y, 200M, and 200C and the black cartridge 200K are disposed overlapping each other in the first direction. Therefore, the width W11 of the black cartridge 200 in the third direction can be made larger than the widths W10 of the other color cartridges 200Y, 200M, and 200C in the third direction.

[0108] In the configuration of this embodiment, it is easy to make the toner storage volume of the black cartridge 200K, which generally consumes more toner than the yellow, magenta, and cyan cartridges 200Y, 200M, and 200C, respectively. Also, the arrangement allows users to intuitively distinguish between the yellow, magenta, and cyan cartridges 200Y, 200M, and 200C and the black cartridge 200K.

[0109] The yellow, magenta, and cyan colors may be arranged in a different order from that in this embodiment. Also, three cartridges 200 may be arranged at the end of the right side of the image forming apparatus 100, and one cartridge may be arranged at the end of the left side.

[0110] Furthermore, similar to the above-described embodiments, the upstream end 311 of the supply pipe 310, the inlet 141, and the outlet 201 may be disposed on the left or right side surface 143 of the cartridge holder 140 in the first direction.

[0111] As described above, according to this embodiment, the same effects as in the first embodiment can be obtained, and the toner storage volume of the cartridge 200 for black, which generally consumes more toner than other colors, can be increased.

[0112] [Example 6] Next, another embodiment of the present invention will be described. The basic configuration and operation of the image forming apparatus of this embodiment are the same as those of embodiment 1. Therefore, in the image forming apparatus of this embodiment, elements having the same or corresponding functions or configurations as those of the image forming apparatus of embodiment 1 are assigned the same reference numerals as those of embodiment 1, and detailed descriptions thereof will be omitted.

[0113] Figure 17(a) is a front view of the image forming unit 500 in this embodiment, viewed from the front side in the second direction, and Figure 17(b) is a perspective view of the image forming unit 500 in this embodiment.

[0114] In this embodiment, the yellow cartridge 200Y and the magenta cartridge 200M are arranged stacked in the second direction. Here, "arranging one cartridge 200 and another cartridge stacked in the second direction" means that at least a portion of one cartridge 200 overlaps (is superimposed on) at least a portion of the other cartridge 200 when viewed in the second direction. In this embodiment, the yellow cartridge 200Y and the magenta cartridge 200M are arranged side by side in the second direction and adjacent to each other. In this embodiment, the yellow cartridge 200Y is arranged on the rear side, and the magenta cartridge is arranged on the front side. Similarly, in this embodiment, the cyan cartridge 200C and the black cartridge 200K are arranged stacked in the second direction. In this embodiment, the cyan cartridge 200C and the black cartridge 200K are arranged side by side in the second direction and adjacent to each other. In this embodiment, the cyan cartridge 200C is arranged on the rear side, and the black cartridge 200K is arranged on the front side.

[0115] Furthermore, the yellow cartridge 200Y and the cyan cartridge 200C are arranged overlapping in the first direction. In this embodiment, the yellow cartridge 200Y and the cyan cartridge 200C are arranged side by side in the first direction. In this embodiment, the yellow cartridge 200Y is arranged on the left side, and the cyan cartridge 200C is arranged on the right side. Similarly, the magenta cartridge 200M and the black cartridge 200K are arranged overlapping in the first direction. In this embodiment, the magenta cartridge 200M and the black cartridge 200K are arranged side by side in the first direction. In this embodiment, the magenta cartridge 200M is arranged on the left side, and the black cartridge 200K is arranged on the right side.

[0116] In particular, in this embodiment, the cartridges 200Y, 200M, 200C, and 200K have substantially the same outer shape. The yellow cartridge 200Y and the magenta cartridge 200M are aligned along the second direction (substantially parallel in this embodiment). In this embodiment, when viewed in the second direction, the yellow cartridge 200Y and the magenta cartridge 200M overlap substantially entirely with each other. Similarly, the cyan cartridge 200C and the black cartridge 200K are aligned along the second direction (substantially parallel in this embodiment). In this embodiment, when viewed in the second direction, the cyan cartridge 200C and the black cartridge 200K overlap substantially entirely with each other. Furthermore, the yellow cartridge 200Y and the cyan cartridge 200C are aligned along the first direction (substantially parallel in this embodiment). In this embodiment, when viewed in the first direction, the yellow cartridge 200Y and the cyan cartridge 200C overlap substantially entirely with each other. Similarly, the magenta cartridge 200M and the black cartridge 200K are aligned (substantially parallel in this embodiment) along the first direction. In this embodiment, when viewed in the first direction, the magenta cartridge 200M and the black cartridge 200K overlap each other almost entirely.

[0117] In this embodiment, the ejection openings 201Y, 201M, and 201C are also provided at the end of the cartridge 200 in the first direction, adjacent to the end of the image forming apparatus 100 in the first direction. In particular, in this embodiment, the ejection openings 201Y, 201M, and 201C are arranged so as not to overlap with any of the optical paths LY, LM, LC, and LK when viewed in the second direction. In this embodiment, the ejection openings 201Y and 201M of the yellow and magenta cartridges 200Y and 200M are respectively arranged at the end of the left side of the cartridge 200Y and 200M, adjacent to the end of the left side of the image forming apparatus 100 in the first direction. Furthermore, in this embodiment, the ejection openings 201C and 201K of the cyan and black cartridges 200C and 200K are respectively arranged at the end of the right side of the cartridge 200C and 200K, adjacent to the end of the right side of the image forming apparatus 100 in the first direction.

[0118] The configuration of this embodiment is advantageous in terms of the configuration of the apparatus main body 110 and usability when the cartridge 200 is configured to be attached and detached along the third direction.

[0119] 17(a), in the configuration of this embodiment, when the discharge port 201 is provided on the surface facing the rear side of the cartridge holder 140, the following can be done: The cartridges 200Y and 200C arranged on the rear side in the second direction are provided with cutouts 203Y and 203C in part so as not to obstruct the toner transport paths of the cartridges 200M and 200K arranged on the front side.

[0120] In this embodiment, the cartridges 200Y, 200M, 200C, and 200K of the respective colors of yellow, magenta, cyan, and black are arranged in the color arrangement described above, but the color arrangement may be different from that in this embodiment.

[0121] Furthermore, similar to the above-described embodiments, the upstream end 311 of the supply pipe 310, the inlet 141, and the outlet 201 may be disposed on the left or right side surface 143 of the cartridge holder 140 in the first direction.

[0122] Furthermore, in a configuration in which the cartridges 200 are stacked in the second direction, similar to Example 2, the yellow, magenta, cyan, and black cartridges 200 may be arranged such that both end portions thereof are adjacent to both end portions of the image forming apparatus 100 in the first direction. The yellow, magenta, cyan, and black cartridges 200 may then be arranged stacked in the second direction. Also, in a configuration in which the cartridges 200 are stacked in the second direction, similar to Example 5, for example, three cartridges 200 may be arranged stacked at one end of the image forming apparatus 100 in the first direction, and one cartridge may be arranged at the other end.

[0123] As described above, according to this embodiment, the same effects as those of the first embodiment can be obtained, and also, an effect that a configuration in which the cartridge 200 can be easily attached and detached along the third direction can be easily adopted can be obtained.

[0124] [others] Although the present invention has been described above with reference to specific embodiments, the present invention is not limited to the above-described embodiments.

[0125] In the above-described embodiment, the image forming apparatus employs an intermediate transfer method, but the present invention is not limited to this. The image forming apparatus may employ, for example, a direct transfer method in which toner images are sequentially transferred from a plurality of photosensitive drums to a recording material carried on a recording material carrier (such as a recording material transport belt).

[0126] Furthermore, the replenishing developer replenished from the cartridge to the developing container may be a so-called two-component developer containing toner and carrier.

[0127] Although not described here, the same conveying means as that described in Example 1 can also be used in Examples 2 to 6. In this case, the positions of the discharge port and the air intake port can be changed appropriately depending on the arrangement of the cartridge.

[0128] In the above embodiment, the image forming apparatus is provided with four toner cartridges and four process units, but the number of toner cartridges and process units is not limited to this and may be set appropriately as needed. The number of cartridges removably provided in the image forming apparatus is not limited to four and may be more (e.g., six) or less (e.g., three). [Explanation of symbols]

[0129] 1 Photosensitive drum 3 Developer container 5 Development unit 6 Drum unit 8 Laser Scanner Unit 100 Image forming device 140 Cartridge Holder 200 toner cartridges (cartridges) 300 Supply Mechanism 500 Image forming unit P Process Unit S recording material

Claims

1. an apparatus main body including: a first photosensitive drum rotatable about a first rotation axis extending in a first direction; a first developing unit including a first developing container that contains a first toner to be supplied to the first photosensitive drum and a first developing roller that carries the first toner contained in the first developing container; and a second photosensitive drum rotatable about a second rotation axis extending in the first direction; and a second developing unit including a second developing container that contains a second toner to be supplied to the second photosensitive drum and a second developing roller that carries the second toner contained in the second developing container; a first cartridge detachably attached to the apparatus main body, the first cartridge containing the first toner and having a first discharge port for discharging the first toner toward the first developing container; a second cartridge detachably attached to the apparatus main body, the second cartridge containing the second toner and having a second discharge port for discharging the second toner toward the second developing container; An image forming apparatus comprising: the first developing unit and the second developing unit are arranged to be aligned in a second direction perpendicular to the first direction, the first cartridge and the second cartridge are disposed at one end of the image forming apparatus in the second direction, the second cartridge is disposed so that at least a portion of the second cartridge overlaps with the first cartridge when viewed in a third direction that is orthogonal to both the first direction and the second direction; When one end and the other end in the first direction of the image forming apparatus are defined as a first end and a second end, respectively, In the first direction, one end of the first cartridge is disposed on the side of the first end of the image forming apparatus, and the first ejection opening is provided at the end of the first cartridge that is on the side of the first end of the image forming apparatus, An image forming apparatus characterized in that, in the first direction, one end of the second cartridge is positioned on the side of the first end of the image forming device, and the second ejection outlet is provided on the end of the second cartridge on the side of the first end of the image forming device.

2. 2. The image forming apparatus according to claim 1, wherein, in the first direction, the first cartridge and the second cartridge are arranged at positions closer to the first end of the image forming apparatus than to the second end.

3. Equipped with a laser scanner, 3. The image forming apparatus according to claim 1, wherein the first discharge outlet and the second discharge outlet are arranged so as not to overlap with the optical paths of the laser light traveling from the laser scanner toward the first photosensitive drum and the second photosensitive drum, respectively, when viewed in the second direction.

4. a first passage through which the first toner passes after being discharged from the first discharge port and heading toward the first developing container; a second passage through which the second toner passes after being discharged from the second discharge port and directed toward the second developing container; and 4. The image forming apparatus according to claim 3, wherein the end of the first passage on the side of the first discharge outlet and the end of the second passage on the side of the second discharge outlet are arranged so as not to overlap with the optical paths of the laser light traveling from the laser scanner toward the first photosensitive drum and the second photosensitive drum, respectively, when viewed in the second direction.

5. the first cartridge includes a first air intake port for receiving air; the second cartridge includes a second air intake port for receiving air; a first pump for pumping air through the first air intake into the first cartridge; a second pump for pumping air through the second air intake into the second cartridge; a first passage through which the first toner passes, the first toner being discharged from the first discharge port by air received through the first air inlet and directed toward the first developing container; a second passage through which the second toner passes, the second toner being discharged from the second discharge port by air received through the second air inlet and directed toward the second developing container; 3. The image forming apparatus according to claim 1, further comprising:

6. the apparatus main body comprises: a third photosensitive drum rotatable about a third rotation axis extending in the first direction; a third developing unit including a third developing container that contains a third toner to be supplied to the third photosensitive drum and a third developing roller that carries the third toner contained in the third developing container; and a fourth photosensitive drum rotatable about a fourth rotation axis extending in the first direction; and a fourth developing unit including a fourth developing container that contains a fourth toner to be supplied to the fourth photosensitive drum and a fourth developing roller that carries the fourth toner contained in the fourth developing container, a third cartridge detachably attached to the apparatus main body, the third cartridge containing the third toner and having a third discharge port for discharging the third toner toward the third developing container; a fourth cartridge detachably attached to the apparatus main body, the fourth cartridge containing the fourth toner and having a fourth discharge port for discharging the fourth toner toward the fourth developing container; Equipped with the first developing unit, the second developing unit, the third developing unit, and the fourth developing unit are arranged to be aligned in the second direction; the third cartridge and the fourth cartridge are disposed at the one end of the image forming apparatus in the second direction, When viewed in the third direction, the fourth cartridge is disposed so that at least a portion of the fourth cartridge overlaps with the third cartridge; In the first direction, the third cartridge and the fourth cartridge are disposed at positions closer to the second end of the image forming apparatus than to the first end, 3. The image forming apparatus according to claim 2, wherein, in the first direction, the third ejection outlet is provided at an end of the third cartridge that is closer to the second end of the image forming apparatus, and the fourth ejection outlet is provided at an end of the fourth cartridge that is closer to the second end of the image forming apparatus.

7. When viewed in the first direction, the third cartridge is disposed so that at least a portion of the third cartridge overlaps with the first cartridge; 7. The image forming apparatus according to claim 6, wherein the fourth cartridge is disposed so that at least a portion of the fourth cartridge overlaps with the second cartridge when viewed in the first direction.

8. Equipped with a laser scanner, 8. The image forming apparatus according to claim 6, wherein the first discharge outlet, the second discharge outlet, the third discharge outlet, and the fourth discharge outlet are arranged so as not to overlap with the optical paths of laser light traveling from the laser scanner toward the first photosensitive drum, the second photosensitive drum, the third photosensitive drum, and the fourth photosensitive drum, respectively, when viewed in the second direction.

9. a first passage through which the first toner passes after being discharged from the first discharge port and heading toward the first developing container; a second passage through which the second toner passes after being discharged from the second discharge port and directed toward the second developing container; a third passage through which the third toner passes after being discharged from the third discharge port and heading toward the third developing container; a fourth passage through which the fourth toner passes after being discharged from the fourth discharge port and heading toward the fourth developing container; and 9. The image forming apparatus according to claim 8, wherein the end of the first passage on the side of the first discharge outlet, the end of the second passage on the side of the second discharge outlet, the end of the third passage on the side of the third discharge outlet, and the end of the fourth passage on the side of the fourth discharge outlet are arranged so as not to overlap with optical paths of laser light directed from the laser scanner to the first photosensitive drum, the second photosensitive drum, the third photosensitive drum, and the fourth photosensitive drum, respectively, when viewed in the second direction.

10. the first cartridge includes a first air intake port for receiving air; the second cartridge includes a second air intake port for receiving air; the third cartridge includes a third air intake port for receiving air; the fourth cartridge includes a fourth air intake port for receiving air; a first pump for pumping air through the first air intake into the first cartridge; a second pump for pumping air through the second air intake into the second cartridge; a third pump for pumping air through the third air intake into the third cartridge; a fourth pump for pumping air through the fourth air intake port into the fourth cartridge; a first passage through which the first toner passes, the first toner being discharged from the first discharge port by air received through the first air inlet and directed toward the first developing container; a second passage through which the second toner passes, the second toner being discharged from the second discharge port by air received through the second air inlet and directed toward the second developing container; a third passage through which the third toner passes, the third toner being discharged from the third discharge port by air received through the third air inlet and directed toward the third developing container; a fourth passage through which the fourth toner passes, the fourth toner being discharged from the fourth discharge port by air received through the fourth air inlet and directed toward the fourth developing container; 8. The image forming apparatus according to claim 6, further comprising:

11. In the first direction, one end of the first cartridge is disposed on a side of the first end of the image forming apparatus, and the other end of the first cartridge is disposed on a side of the second end of the image forming apparatus, 2. The image forming apparatus according to claim 1, wherein, in the first direction, one end of the second cartridge is positioned on the side of the first end of the image forming apparatus, and the other end of the second cartridge is positioned on the side of the second end of the image forming apparatus.

12. the apparatus main body includes a third photosensitive drum rotatable about a third rotation axis extending in the first direction, a third developing unit including a third developing container that contains a third toner to be supplied to the third photosensitive drum, and a third developing roller that carries the third toner contained in the third developing container; a third cartridge detachably attached to the apparatus main body, the third cartridge containing the third toner and having a third discharge port for discharging the third toner toward the third developing container; the first developing unit, the second developing unit, and the third developing unit are arranged to be aligned in the second direction; the third cartridge is disposed at the one end of the image forming apparatus in the second direction, When viewed in the first direction, the third cartridge is disposed so that at least a portion thereof overlaps with the first cartridge and at least a portion thereof overlaps with the second cartridge; In the first direction, the third cartridge is disposed at a position closer to the second end of the image forming apparatus than to the first end, 3. The image forming apparatus according to claim 2, wherein, in the first direction, the third discharge port is provided at an end of the third cartridge that is closer to the second end of the image forming apparatus.

13. 13. The image forming apparatus according to claim 12, wherein the storage volume of the third toner in the third cartridge is larger than the storage volume of the first toner in the first cartridge and is larger than the storage volume of the second toner in the second cartridge.

14. the first cartridge has a first region and a second region in the first direction, and in the third direction, the width of the first region is a first width, and the width of the second region is a second width that is larger than the first width; the second cartridge has a third region and a fourth region in the first direction, the width of the third region in the third direction being a third width, and the width of the fourth region in the third direction being a fourth width smaller than the third width; 3. The image forming apparatus of claim 1, wherein when viewed in the third direction, the third region is positioned so that at least a portion thereof overlaps with the first region, and the fourth region is positioned so that at least a portion thereof overlaps with the second region, and when viewed in the second direction, the third region is positioned so that at least a portion thereof overlaps with the second region.

15. the first cartridge has a fifth region located on the opposite side of the first region with the second region interposed therebetween in the first direction, and a width of the fifth region in the third direction is a fifth width that is smaller than the second width; the second cartridge has a sixth region located on the opposite side of the third region with the fourth region interposed therebetween in the first direction, and a width of the sixth region in the third direction is a sixth width that is larger than the fourth width; 15. The image forming apparatus according to claim 14, wherein the sixth region is arranged so that, when viewed in the third direction, at least a portion of the sixth region overlaps with the fifth region, and when viewed in the second direction, at least a portion of the sixth region overlaps with the second region.

16. an apparatus main body including: a first photosensitive drum rotatable about a first rotation axis extending in a first direction; a first developing unit including a first developing container that contains a first toner to be supplied to the first photosensitive drum and a first developing roller that carries the first toner contained in the first developing container; and a second photosensitive drum rotatable about a second rotation axis extending in the first direction; and a second developing unit including a second developing container that contains a second toner to be supplied to the second photosensitive drum and a second developing roller that carries the second toner contained in the second developing container; a first cartridge detachably attached to the apparatus main body, the first cartridge containing the first toner and having a first discharge port for discharging the first toner toward the first developing container; a second cartridge detachably attached to the apparatus main body, the second cartridge containing the second toner and having a second discharge port for discharging the second toner toward the second developing container; An image forming apparatus comprising: the first developing unit and the second developing unit are arranged to be aligned in a second direction perpendicular to the first direction, the first cartridge and the second cartridge are disposed at one end of the image forming apparatus so as not to overlap with either the first developing unit or the second developing unit in the second direction; When viewed in the second direction, the second cartridge is disposed so that at least a portion of the second cartridge overlaps with the first cartridge; When one end and the other end in the first direction of the image forming apparatus are defined as a first end and a second end, respectively, In the first direction, one end of the first cartridge is disposed on the side of the first end of the image forming apparatus, and the first ejection opening is provided at the end of the first cartridge that is on the side of the first end of the image forming apparatus, An image forming apparatus characterized in that, in the first direction, one end of the second cartridge is positioned on the side of the first end of the image forming device, and the second ejection outlet is provided on the end of the second cartridge on the side of the first end of the image forming device.

17. 17. The image forming apparatus according to claim 16, wherein, in the first direction, the first cartridge and the second cartridge are arranged at positions closer to the first end of the image forming apparatus than to the second end.

18. the apparatus main body comprises: a third photosensitive drum rotatable about a third rotation axis extending in the first direction; a third developing unit including a third developing container that contains a third toner to be supplied to the third photosensitive drum and a third developing roller that carries the third toner contained in the third developing container; and a fourth photosensitive drum rotatable about a fourth rotation axis extending in the first direction; and a fourth developing unit including a fourth developing container that contains a fourth toner to be supplied to the fourth photosensitive drum and a fourth developing roller that carries the fourth toner contained in the fourth developing container, a third cartridge detachably attached to the apparatus main body, the third cartridge containing the third toner and having a third discharge port for discharging the third toner toward the third developing container; a fourth cartridge detachably attached to the apparatus main body, the fourth cartridge containing the fourth toner and having a fourth discharge port for discharging the fourth toner toward the fourth developing container; Equipped with the first developing unit, the second developing unit, the third developing unit, and the fourth developing unit are aligned in the second direction, the first cartridge, the second cartridge, the third cartridge, and the fourth cartridge are disposed at the one end of the image forming apparatus so as not to overlap with any of the first developing unit, the second developing unit, the third developing unit, and the fourth developing unit in the second direction; the fourth cartridge is disposed so that at least a portion of the fourth cartridge overlaps with the third cartridge when viewed in the second direction; In the first direction, the third cartridge and the fourth cartridge are disposed at positions closer to the second end of the image forming apparatus than to the first end, 18. The image forming apparatus according to claim 17, wherein, in the first direction, the third ejection outlet is provided at an end of the third cartridge that is closer to the second end of the image forming apparatus, and the fourth ejection outlet is provided at an end of the fourth cartridge that is closer to the second end of the image forming apparatus.

19. When viewed in the first direction, the third cartridge is disposed so that at least a portion of the third cartridge overlaps with the first cartridge; 19. The image forming apparatus according to claim 18, wherein the fourth cartridge is disposed so that at least a portion of the fourth cartridge overlaps with the second cartridge when viewed in the first direction.

Images