Image forming device

Abstract

To improve the transportability of developer from a developer container detachable from the main body of an apparatus to a storage section of the main body of an apparatus. [Solution] In an image forming device, of multiple developer containers aligned in a second direction perpendicular to a first direction in which multiple development units are aligned, a first developer container extends from a first communication port of a detachable mounting portion to a first receiving port of the first development unit, and includes a first pipe through which developer discharged from a first discharge port of the first developer container passes, and has multiple pipes through which developer passes as it is transported from the multiple developer containers to the corresponding multiple development units by air supplied from an air supply portion, and the first developer container is located at a position among the multiple developer containers closest to the first end face in the second direction, and the first pipe is located at a position among the multiple pipes closest to the first end face in the second direction, and when viewed in the first direction, at least a portion of the first communication port overlaps with the first receiving port.

Description

[Technical Field]

[0001] The present invention relates to an image forming apparatus in which developer is replenished from a developer supply container that is detachable from the image forming apparatus. [Background technology]

[0002] In electrophotographic image forming apparatuses, a configuration is known in which toner (developer) is replenished to a developing container (main body storage section) of a developing unit in the image forming apparatus using a toner cartridge, which is a toner container (developer container) that can be attached to and detached from the image forming apparatus. Patent Document 1 discloses a configuration in which toner can be easily replenished without replacing the developing container by attaching a toner cartridge to the image forming apparatus. In the configuration of Patent Document 1, toner is supplied from the toner cartridge to the developing container using a screw inside a toner transport path. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2023-007030 Summary of the Invention [Problem to be solved by the invention]

[0004] In Patent Document 1, the toner transport path connecting the toner cartridge to the developing unit is bent multiple times to avoid the laser light and to connect to the toner receiving port located in the longitudinal center of the developing unit, which may impair the toner transport force.

[0005] An object of the present invention is to provide a technique capable of improving the transportability of developer from a developer container detachable from the main body of the apparatus to a developer storage unit in the main body of the apparatus. [Means for solving the problem]

[0006] In order to solve the above-mentioned problems, an image forming apparatus according to the present invention comprises: an apparatus body including a plurality of photosensitive drums including a first photosensitive drum, a first developing unit provided with a first receiving port and having a first developing roller that supplies developer received from the first receiving port to the first photosensitive drum, and a plurality of developing units aligned in a first direction; and an air supply unit; a first developer container that contains a developer and is provided with a first discharge port, the first developer container being detachable from the device main body, and a plurality of developer containers that are aligned in a second direction perpendicular to the first direction; Equipped with The device body includes: a mounting portion to which the plurality of developer containers can be detachably attached, the mounting portion being provided with a first communication port that can communicate with the first discharge port; a plurality of pipes through which the developer conveyed from the plurality of developer containers to the corresponding plurality of developing units by air supplied from the air supply unit passes, the plurality of pipes including a first pipe extending from the first communication port to the first receiving port and through which the developer discharged from the first discharge port passes; and When one end surface and the other end surface of the device body in the second direction are a first end surface and a second end surface, The first developer container is the developer container closest to the first developer container in the second direction. 1 Located near the end face, the first pipe is provided at a position among the plurality of pipes closest to the first end face in the second direction, When viewed in the first direction, at least a portion of the first communication port overlaps with the first receiving port. It is characterized by: [Effects of the Invention]

[0007] According to the present invention, it is possible to improve the transportability of developer from a developer container detachable from the main body of the apparatus to a developer storage unit in the main body of the apparatus. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is a top view of an image forming apparatus according to a first embodiment of the present invention; [Figure 2] 1 is a cross-sectional view of an image forming apparatus according to a first embodiment of the present invention; [Figure 3] 1 is a perspective view of an image forming apparatus according to a first embodiment of the present invention; [Figure 4] FIG. 1 is a perspective view of an image forming unit according to a first embodiment; [Figure 5] FIG. 1 is a perspective view of an image forming unit according to a first embodiment; [Figure 6] 1 is a cross-sectional view of an image forming unit and a laser scanner according to a first embodiment. [Figure 7] 1 is a diagram illustrating the configuration of a cartridge according to Example 1. [Figure 8] 1A and 1B are a cross-sectional view and an exploded perspective view of a cartridge according to a first embodiment; [Figure 9] 1A and 1B are a cross-sectional view and a perspective view of a cartridge according to a first embodiment; [Figure 10] Illustration of overlap configuration [Figure 11] Illustration of overlap configuration DETAILED DESCRIPTION OF THE INVENTION

[0009] The following describes in detail exemplary embodiments of the present invention with reference to the drawings. However, the dimensions, materials, shapes, and relative positions of the components described in the embodiments may be modified as appropriate depending on the configuration of the device to which the invention is applied and various conditions. In other words, the scope of the present invention is not limited to the following embodiments. Furthermore, although the embodiments describe multiple features, not all of these features are necessarily essential to the invention, and multiple features may be combined arbitrarily. Furthermore, in the accompanying drawings, the same reference numerals are used to designate identical or similar components, and redundant explanations will be omitted.

[0010] Example 1 [Image forming device] An image forming apparatus 1 according to a first embodiment of the present invention will be described with reference to FIG. 2. The electrophotographic image forming apparatus 1 of this embodiment is a full-color image forming apparatus equipped with four-color process cartridges. FIG. 2 is a schematic cross-sectional view showing the general configuration of the image forming apparatus 1. The image forming apparatus 1 is a full-color laser printer that uses an electrophotographic process, and is capable of forming a full-color image on a recording medium S using four-color (yellow, magenta, cyan, and black) toners (developers). The image forming apparatus 1 includes process cartridges PY, PM, PC, and PK, and an apparatus main body 72.

[0011] Here, Y, M, C, and B added to the end of the reference numerals attached to each component of the image forming apparatus 1 are identifiers for distinguishing the toner colors (yellow (Y), magenta (M), cyan (C), and black (B)) that correspond to the component. In the following explanations, Y, M, C, and B may be omitted unless a distinction between colors is required.

[0012] Each process cartridge P is aligned in the X direction (the horizontal direction intersecting with the axial direction of the photosensitive drum). The process cartridges P are aligned in a direction substantially parallel to the X axis (first direction), and the toner (developer) contained therein is different in color from one another. The longitudinal direction of the process cartridge P (the axial direction of the photosensitive drum) is the Y axis (second direction) that intersects with the X axis and the first direction.

[0013] The image forming apparatus 1 according to this embodiment is typically installed and used on a horizontal surface, and the X and Y directions shown in the drawings are horizontal directions that are perpendicular to each other. The Z direction shown in the drawings is perpendicular to both the X and Y directions and is a direction along the vertical direction (gravity direction, height direction, up-down direction).

[0014] In this embodiment, the process cartridges P are aligned in a direction (first direction) substantially parallel to the X direction, but this direction may coincide with the X direction or may be at a slight angle relative to the X direction. FIG. 2 shows an example of an apparatus configuration in which the first direction coincides with the X direction, and FIG. 6 shows an example of an apparatus configuration in which the first direction is slightly inclined relative to the X direction. Both apparatus configurations are identical in terms of functionality, etc., except for the difference in the layout of the toner supply configuration from the toner cartridge 430 to the process cartridge P, which will be described later, and the present invention is applicable to either configuration. In this embodiment, the first direction, which is the alignment direction of the process cartridges P, and the second direction, which is the longitudinal direction of the process cartridge P (the axial direction of the photosensitive drum), are perpendicular to each other, but they may also intersect at an angle slightly different from the perpendicular. In other words, the angle between the first direction and the second direction does not have to be perpendicular (right angle) but may intersect each other.

[0015] Each process cartridge P has an electrophotographic process element. A rotational driving force is transmitted to the process cartridge P from a drive output unit (not shown) of the apparatus main body 72, and a bias voltage (charging bias, developing bias, etc.) is supplied to the process cartridge P from a bias application unit (not shown) of the apparatus main body 72.

[0016] As shown in FIG. 2, each process cartridge P includes a drum unit 8Y, 8M, 8C, or 8K. Each drum unit 8 includes a photosensitive drum 4Y, 4M, 4C, or 4K, which serves as an image carrier, and a charging roller 5Y, 5M, 5C, or 5K, which serves as a process means acting on the photosensitive drum 4. Each photosensitive drum 4 is disposed so that its rotation axis extends along the Y direction. That is, each photosensitive drum 4 is rotatable about its rotation axis extending in the Y direction (second direction). Each process cartridge P includes a developing unit 9Y, 9M, 9C, or 9K, which includes a developing roller 6Y, 6M, 6C, or 6K, which serves as a developer supplying member for developing an electrostatic latent image on the corresponding photosensitive drum 4. Each developing unit 9Y, 9M, 9C, or 9K is aligned along the X direction.

[0017] The developing unit 9Y has a developing container 3Y as a main body accommodating portion that accommodates yellow (Y) toner, and a developing roller 6Y as a developer carrier that carries yellow (Y) toner. The developing roller 6Y supplies yellow (Y) toner to the surface of the photosensitive drum 4Y. The developing unit 9M has a developing container 3M as a main body accommodating portion that accommodates magenta (M) toner, and a developing roller 6M as a developer carrier that carries magenta (M) toner. The developing roller 6M supplies magenta (M) toner to the surface of the photosensitive drum 4M. The developing unit 9C has a developing container 3C as a main body accommodating portion that accommodates cyan (C) toner, and a developing roller 6C as a developer carrier that carries cyan (C) toner. The developing roller 6C supplies cyan (C) toner to the surface of the photosensitive drum 4C. The developing unit 9K has a developing container 3K as a main body-side storage section that stores black (K) toner, and a developing roller 6K as a developer carrier that carries black (K) toner. The developing roller 6K supplies black (K) toner to the surface of the photosensitive drum 4K.

[0018] In the Z direction (third direction) intersecting both the X direction (first direction) and the Y direction (second direction), a laser scanner unit LB (exposure unit) is provided above the process cartridge P (photosensitive drum 4) as an exposure unit. This laser scanner unit LB outputs laser light corresponding to image information and irradiates each photosensitive drum 4. Hereinafter, the optical paths of the laser light toward the photosensitive drums 4Y, 4M, 4C, and 4K are referred to as optical paths LY, LM, LC, and LK, respectively. The laser light then passes through exposure windows 10Y, 10M, 10C, and 10K of the laser scanner unit LB to scan and expose the surface of each photosensitive drum 4. Note that an LED exposure unit may be used as the exposure unit instead of the laser scanner unit LB.

[0019] An intermediate transfer belt unit 11 serving as a transfer member is provided below the process cartridge P in the Z direction. The intermediate transfer belt unit 11 includes a drive roller 14, a tension roller 13, and an assist roller 15, and a flexible transfer belt 12 is wound around the intermediate transfer belt unit 11. The lower end region of each photosensitive drum 4 contacts an upwardly facing region of the circumferential surface of the transfer belt 12. The contact points between the photosensitive drums 4 and the transfer belt 12 are primary transfer portions 30Y, 30M, 30C, and 30K. Primary transfer rollers 16Y, 16M, 16C, and 16K are provided on the inside of the transfer belt 12 at positions corresponding to the photosensitive drums 4Y, 4M, 4C, and 4K, with the transfer belt 12 sandwiched therebetween. A secondary transfer roller 17 is pressed against the drive roller 14 via the transfer belt 12. The contact point between the transfer belt 12 and the secondary transfer roller 17 is a secondary transfer portion 31.

[0020] A feeding unit 18 is provided below the intermediate transfer belt unit 11 in the Z direction. The feeding unit 18 has a paper feed tray 19 that stores a stack of recording media (recording materials) S, such as recording paper or sheets, and a paper feed roller 20 that picks up and transports the recording media S from the paper feed tray 19. A fixing unit 21 that fixes a toner image to the recording medium S and a discharge roller 22 that discharges the recording medium S with the fixed toner image onto a discharge tray 23 are provided at the top of the device main body 72 in FIG. 2 . The discharge roller 22 discharges the recording medium S in the X direction. In this embodiment, the downstream side of the discharge direction in which the recording medium S is discharged by the discharge roller 22 toward the discharge tray 23 is the front side of the image forming apparatus 1, and the upstream side of the discharge direction is the rear side of the image forming apparatus 1.

[0021] [Image formation operation] The image forming operation for forming a full-color image is as follows. Each photosensitive drum 4 is rotated counterclockwise in FIG. 2 at a predetermined speed. The transfer belt 12 is rotated in the same direction as the rotation of each photosensitive drum 4 (the direction of arrow C in FIG. 2) as the photosensitive drum 4, at a speed corresponding to the rotational speed of each photosensitive drum 4. The laser scanner unit LB is also driven. In synchronization with the drive of the laser scanner unit LB, each charging roller 5 in each process cartridge P uniformly charges the surface of each corresponding photosensitive drum 4 to a predetermined polarity and potential. The laser scanner unit LB scans and exposes the charged surface of each photosensitive drum 4 with laser light in accordance with the image signal for each color. An electrostatic latent image corresponding to the image signal for each color is formed on the surface of each photosensitive drum 4. The electrostatic latent image on each photosensitive drum 4 is developed by the supply of toner to each photosensitive drum 4 by each developing roller 6, which is rotated clockwise in FIG. 2 at a predetermined speed.

[0022] By the electrophotographic image forming process described above, a yellow toner image is formed on the photosensitive drum 4Y of the process cartridge PY. Then, this yellow toner image is primarily transferred onto the transfer belt 12. Similarly, a magenta toner image is formed on the photosensitive drum 4M of the process cartridge PM. Then, the magenta toner image is primarily transferred onto the transfer belt 12 so as to be superimposed on the yellow toner image on the transfer belt 12. A cyan toner image is formed on the photosensitive drum 4C of the process cartridge PC. Then, the cyan toner image is transferred onto the yellow and magenta toner images on the transfer belt 12. A black toner image is formed on the photosensitive drum 4K of the process cartridge PK. The black toner image is then primarily transferred onto the transfer belt 12 so as to be superimposed on the yellow, magenta, and cyan toner images on the transfer belt 12.

[0023] In this way, an unfixed four-color full-color toner image of yellow, magenta, cyan, and black is formed on the transfer belt 12. Meanwhile, at a predetermined control timing, the recording medium S is separated one by one from the paper feed tray 19 by the paper feed roller 20 and fed. The recording medium S is introduced into the secondary transfer unit 31, which is the contact point between the secondary transfer roller 17 and the transfer belt 12, at a predetermined control timing. As the recording medium S is transported through the secondary transfer unit 31, the four-color superimposed toner image on the transfer belt 12 is transferred onto the recording medium S. The recording medium S with the transferred toner image is heated and pressurized by the fixing unit 21, and the toner image is fixed to the recording medium S. The recording medium S with the fixed toner image is discharged to the discharge tray 23 by the discharge roller 22.

[0024] [Toner cartridge description] The image forming apparatus 1 has toner cartridges 430Y, 430M, 430C, and 430K (hereinafter referred to as toner cartridges 430) as developer containers that are detachable from the apparatus main body 72. The toner cartridges 430 are aligned in the Y direction (second direction) at positions that are aligned with the developing units 9 in the X direction (first direction). In other words, the toner cartridges 430 are aligned in a direction that intersects (is perpendicular to) the direction in which the developing units 9 are aligned.

[0025] Fig. 3(a) is a perspective view of the image forming apparatus 1 in a state where the front door 72b serving as an opening / closing member is closed. Fig. 3(b) is a perspective view of the image forming apparatus 1 in a state where the front door 72b is open. Fig. 3(c) is a perspective view of the image forming apparatus 1 in a state where the toner cartridge 430M is removed from the toner cartridge holder 429 with the front door 72b open.

[0026] Each toner cartridge 430 is attached to the upper front side of the device body 72 and is exposed to the outside through an opening 73 formed on the front side of the device body 72 by opening the front door 72b, making it accessible to the user. In other words, each toner cartridge 430 is provided at an end of the device body 72 downstream in the discharge direction of the recording medium S discharged by the discharge roller 22. The front door 72b is configured to be movable between a closed position (see FIG. 3(a)) that closes the device body 72 on the front side and an open position (see FIG. 3(b)) that opens it. When the front door 72b is moved to the open position, as shown in FIG. 3(b), each toner cartridge 430 is exposed to the outside of the image forming apparatus 1. The toner cartridges 430 are arranged side by side in the Y direction (second direction) and are configured to be attachable to and detachable from the device body 72 in the X direction (first direction) as shown in FIG. 3(c). This makes it possible to replace the toner cartridge 430 without removing each process cartridge P from the apparatus main body 72, and to continuously replenish toner in each process cartridge P. By arranging each toner cartridge 430 on the front side of the image forming apparatus 1, each toner cartridge 430 can be accessed from the front side, just as when collecting the recording medium S discharged to the discharge tray 23. In addition, since a toner cartridge holder 429 serving as an attachment portion is provided on the front side of the image forming apparatus 1, the process cartridge P is not exposed even after each toner cartridge 430 is removed (see FIG. 3(c)). Each toner cartridge 430 is stored within the apparatus main body 72 when the front door 72b is closed.

[0027] As shown in FIG. 3(a), the image forming apparatus 1 has indicators 208Y and 20 Indicators 208 are provided in the form of indicators 208M, 208C, and 208K (marking portions, display portions). The indicators 208 are lined up in the Y direction (second direction) to correspond to the respective toner cartridges 430. Indicator 208Y is yellow, indicator 208M is magenta, indicator 208C is cyan, and indicator 208K is black. Each indicator 208 is composed of an LED or a sticker of a color corresponding to the color of toner in each cartridge, and is provided to prevent the toner cartridges 430 from being installed incorrectly. Furthermore, each indicator 208 may have a function to display the remaining toner amount in the corresponding process cartridge P (each developing unit 9).

[0028] 1 and 4(a) to 6(b), the toner transport mechanism of each toner cartridge 430 will be described. A unit including each toner cartridge 430, each process cartridge P, and a cartridge tray 74 (drawer member) that supports them is referred to as an image forming unit 500. The image forming unit 500 also includes a transport path for transporting toner from each toner cartridge 430 to each process cartridge P, which will be described later.

[0029] In this embodiment, the four process cartridges PY, PM, PC, and PK are each mounted on a cartridge tray 74 and are configured to be movable integrally with the cartridge tray 74 relative to the apparatus main body 72. The cartridge tray 74 is configured to be movable between an mounted position inside the apparatus main body 72 and an extracted position outside the apparatus main body 72 through an opening 73 in the apparatus main body 72 that is formed when the front door 72b is opened. The mounted position is a position where each process cartridge P is located at a predetermined mounted position in the apparatus main body 72. The extracted position is a position where each process cartridge P is located outside the apparatus main body 72, allowing each process cartridge P to be replaced.

[0030] In this embodiment, each toner cartridge 430 and a transport mechanism that transports toner from the toner cartridge 430 to the process cartridge P are also integrally mounted on the cartridge tray 74. That is, the toner cartridge 430 and the toner transport unit are configured to move between the inside and outside of the apparatus main body 72 by moving the cartridge tray 74. That is, the toner cartridge 430 is not only detachable from the apparatus main body 72 when the cartridge tray 74 is in the mounted position shown in FIG. 3(c), but is also detachable when the cartridge tray 74 is in the pulled-out position. Note that the configuration of the process cartridge P is not limited to this configuration, and at least a portion of the process cartridge P may be fixed to the apparatus main body 72 or the cartridge tray 74. Also, the process cartridge P may be detachable from the apparatus main body 72 in a direction different from the mounting and removal direction of the toner cartridge 430. Also, the toner cartridge 430 and the toner transport unit may be provided in the apparatus main body 72, not in the cartridge tray 74.

[0031] Fig. 1 is a top view of the image forming unit 500. Fig. 4(a) is a perspective view of the image forming unit 500 with the toner cartridges 430 attached. Fig. 4(b) is a perspective view of the image forming unit 500 with the toner cartridges 430 removed. Fig. 5 is a perspective view showing the optical path of the laser light from the laser scanner unit LB relative to the image forming unit 500. Figs. 6(a) and 6(b) are cross sections taken along lines AA and BB in Fig. 1, respectively.

[0032] As shown in Figures 4(a) and 5, the cartridge tray 74 is provided with a toner cartridge holder 429 and pump units 80Y, 80M, 80C, and 80K as air supply units for supplying compressed air to the inside of the toner cartridge 430. The pump units 80 are arranged below the toner cartridge holder 429. The pump units 80 are aligned in the Y direction (second direction). Positive displacement pumps such as reciprocating pumps and rotary pumps can be used. Reciprocating pumps are pumps that perform suction and discharge by the reciprocating motion of a piston or plunger, and include piston pumps, plunger pumps, and diaphragm pumps. Rotary pumps are pumps that perform suction and discharge by the rotational motion of a gear or rotor, and include gear pumps, screw pumps, and vane pumps. Four pump units 80 may be provided corresponding to the four toner cartridges 430, or a single pump unit 80 may be provided to supply compressed air to the four toner cartridges 430. In this embodiment, each pump unit 80 is provided as a component on the device main body 72 side, but it may also be provided in each toner cartridge 430.

[0033] Each pump unit 80 is provided with outlets 80aY, 80aM, 80aC, and 80aK through which the generated compressed air is discharged. As shown in FIGS. 4(b) and 6(a), an opening is provided in the toner cartridge holder 429 at a portion facing the lower surface of each toner cartridge 430, through which the outlet 80a of each pump unit 80 is exposed. Each outlet 80a opens upward. The compressed air discharged upward from each outlet 80a is supplied to the inside of each toner cartridge 430 attached to the toner cartridge holder 429. The compressed air supplied to the inside of each toner cartridge 430 is discharged to the outside together with the toner from each toner cartridge 430.

[0034] [Toner cartridge structure] The structure of each toner cartridge 430 (toner container) of this embodiment will be described with reference to FIG. 4(a) and FIG. 7(a) to FIG. 9(b).

[0035] As shown in FIG. 4(a), the width La of toner cartridge 430K in the Y direction is wider than the width Lb of toner cartridges 430Y, 430M, and 430C. Therefore, the toner capacity of toner cartridge 430K is greater than the capacity of toner cartridges 430Y-C. By allowing toner cartridge 430K to accommodate more black toner, which is generally consumed more frequently, than toner of other colors, the number of times toner cartridges 430Y, 430M, 430C, and 430K are replaced more frequently. Since the structure of each toner cartridge 430 is the same except for the width in the Y direction, only the structure of toner cartridge 430Y will be described here, and a description of the structures of toner cartridges 430M, 430C, and 430K will be omitted.

[0036] Figures 7(a), 7(b), 7(c), 7(d), and 7(e) are a front view, a top view, a bottom view, a right side view, and a rear view, respectively, of toner cartridge 430Y. Figure 8(a) is a cross-sectional view taken along line HH of Figure 7(e). Figure 8(b) is a cross-sectional perspective view of toner cartridge 430Y. Figure 8(c) is an exploded perspective view of toner cartridge 430Y. Figure 9(a) is a cross-sectional view taken along line G-G of Figure 7(b). Figure 9(b) is a cross-sectional perspective view of Figure 7(a). Note that the following description of the structure of toner cartridge 430Y is based on the assumption that toner cartridge 430Y is in a state (position) attached to toner cartridge holder 429.

[0037] As shown in FIGS. 8(a) and 8(b), the toner cartridge 430Y has a first frame 430aY, a second frame 430bY, a filter 83Y (ventilation member), and a discharge pipe 85Y. Although not shown, the toner cartridge 430M also has a first frame 430aM, a second frame 430bM, a filter 83M (ventilation member), and a discharge pipe 85M. The toner cartridge 430C also has a first frame 430aC, a second frame 430bC, a filter 83C (ventilation member), and a discharge pipe 85C. The toner cartridge 430K also has a first frame 430aK, a second frame 430bK, a filter 83K, and a discharge pipe 85K.

[0038] Although the first frame 430aY and the second frame 430bY of the toner cartridge 430Y in this embodiment are members molded from resin, they may also be formed from paper or the like. As shown in Fig. 7(e), a discharge port 430a1Y (developer discharge port) for discharging toner is provided on the rear surface 4300aY of the first frame 430aY. As shown in Fig. 7(c), a receiving port 430b1Y (air receiving port) for receiving compressed air for transporting toner is provided on the bottom surface 4300bY of the second frame 430bY.

[0039] The discharge port 430a1Y and the receiving port 430b1Y are preferably provided on the surface of the toner cartridge 430Y excluding the surface (surface facing the Y direction) intersecting the Y direction (second direction), in which the toner cartridges 430 are aligned. This reduces the gap G (Gym, Gmc, Gck) between the toner cartridges 430 shown in FIG. 4(a). As a result, the width L of each toner cartridge 430 can be increased, thereby increasing the volume for storing toner. Note that the gap Gym is the gap between the toner cartridge 430Y and the toner cartridge 430M in the Y direction (second direction). The gap Gmc is the gap between the toner cartridge 430M and the toner cartridge 430C in the Y direction (second direction). The gap Gck is the gap between the toner cartridge 430C and the toner cartridge 430K in the Y direction (second direction).

[0040] The discharge opening 430a1Y is provided on the rear surface 4300aY of the toner cartridge 430Y (the end surface on the downstream side in the installation direction of the toner cartridge 430Y) so as to open toward the downstream side in the installation direction (a direction substantially along the -X direction). Therefore, when the toner cartridge 430Y is installed in the toner cartridge holder 429, the discharge opening 430a1Y can be easily engaged so as to communicate with the receiving opening 429aY (communication opening) of the toner cartridge holder 429. The discharge opening 430a1Y may be provided on the bottom surface 4300bY or top surface of the toner cartridge 430Y, and the receiving opening 430b1Y may be provided on the rear surface 4300aY or top surface. If there is sufficient space in the device main body 72, the discharge opening 430a1Y and the receiving opening 430b1Y may be provided on a surface intersecting the Y direction (second direction). Although not shown, toner cartridge 430M has an outlet 430a1M and an inlet 430b1M arranged in the same manner as toner cartridge 430Y. Toner cartridge 430C has an outlet 430a1C and an inlet 430b1C arranged in the same manner as toner cartridge 430Y. Toner cartridge 430K has an outlet 430a1K and an inlet 430b1K arranged in the same manner as toner cartridge 430Y.

[0041] Discharge opening 430a1Y may be provided with a sealing member (seal or shutter) (not shown). When toner cartridge 430Y is not attached to toner cartridge holder 429, the sealing member seals discharge opening 430a1Y and prevents toner T inside toner cartridge 430Y from leaking out of toner cartridge 430Y. When toner cartridge 430Y is attached to toner cartridge holder 429, the sealing member is removed or moved so that discharge opening 430a1Y is opened.

[0042] 7(a) shows the color of the toner inside the toner cartridge 430Y. The label 430c may also include instructions on how to install the toner cartridge 430Y in the toner cartridge holder 429, or may display some other information about the toner cartridge 430Y.

[0043] The first frame 430aY has a flange portion 430a2Y, and the second frame 430bY has a flange portion 430b2Y. The flange portions 430a2Y and 430b2Y may be fixed to each other with adhesive or screws.

[0044] The filter 83Y is provided to partition (separate or divide) the internal space SPY of the toner cartridge 430Y into two spaces: a toner chamber 430cY (developer storage chamber) and an air chamber 430dY. In other words, the air chamber 430dY is adjacent to the toner chamber 430Yc via the filter 83Y. Although not shown, the filter 83M of the magenta toner cartridge 430M is provided to partition the internal space SPM of the toner cartridge 430M into the toner chamber 430cM and the air chamber 430dM. In other words, the air chamber 430dM is adjacent to the toner chamber 430cM via the filter 83M. The filter 83C of the cyan toner cartridge 430C is provided to partition the internal space SPC of the toner cartridge 430C into the toner chamber 430cC and the air chamber 430dC. In other words, the air chamber 430dC is adjacent to the toner chamber 430cC via the filter 83C. The filter 83K of the black toner cartridge 430K is provided to separate the internal space SPK of the toner cartridge 430K into the toner chamber 430cK and the air chamber 430dK. In other words, the air chamber 430dK is adjacent to the toner chamber 430cK via the filter 83K.

[0045] The toner chamber 430cY is located above the air chamber 430dY and is aligned with the air chamber 430dY in the Z direction (third direction). In other words, the toner cartridge 430Y is mounted in the apparatus main body 72 in a position where the toner chamber 430cY is above the air chamber 430dY. The third direction (Z direction) in which the toner chamber 430cY and the air chamber 430dY are aligned intersects (is perpendicular to) both the first direction (X direction) in which the process cartridges P are aligned and the second direction (Y direction) in which the toner cartridges 430 are aligned. Therefore, in this embodiment, the receiving opening 430b1Y opens toward this alignment direction, and the discharge opening 430a1Y opens in a direction intersecting this alignment direction.

[0046] The filter 83Y is configured to allow air to pass through but prevent toner from passing through, and within the toner cartridge 430Y, the toner T is contained only in the toner chamber 430cY. The filter 83Y is provided to separate the toner chamber 430cY and the air chamber 430dY into upper and lower sections, and the toner T is supported by the filter 83Y in the toner chamber 430cY. In other words, the filter 83Y forms the bottom of the toner chamber 430cY. The receiving port 430b1Y is provided to communicate with the air chamber 430dY, and compressed air supplied from the pump unit 80Y is introduced into the air chamber 430dY through the receiving port 430b1Y.

[0047] No toner is stored in the air chamber 430dY. The filter 83Y is made of a porous material, such as resin fibers, and has pores of a size and density that allow air to pass through but prevent toner from passing through. In other words, the filter 83Y is configured to allow air to pass through but prevent toner from passing through.

[0048] As shown in FIGS. 8(a) to 9(c), the filter 83Y has an outer edge 83aY sandwiched between a flange 430a2Y of the first frame 430aY and a flange 430b2Y of the second frame 430bY, and is held between the first frame 430aY and the second frame 430bY. The filter 83Y has a recessed shape inward from the outer edge 83aY, with the recessed shape being most downward at the center of the filter 83Y. That is, the filter 83Y has a bottom portion 83bY that protrudes from the outer edge 83aY in a direction (third direction) from the toner chamber 430cY toward the air chamber 430dY. The bottom portion 83bY of this recessed shape is located at the outer edge 83aY. Y, and the surface of the filter 83Y facing the toner chamber 430cY is a generally bowl-shaped slope from the outer edge 83aY to the bottom 83bY. In other words, the surface of the filter 83Y facing the toner chamber 430cY has a shape (slope) that slopes downward from the outer edge 83aY toward (closer to) the bottom 83Yb in the X direction (first direction), the Y direction (second direction), or the horizontal direction. In this embodiment, a filter 83Y molded in the above shape is used.

[0049] The toner chamber 430cY is provided with a discharge pipe 85Y (passage). In this embodiment, the discharge pipe 85Y is a member molded from resin, but it may also be made from paper, rubber, or the like. The discharge pipe 85Y has an inlet 85aY (first opening) and an outlet 85bY (second opening), and is a pipe extending from the inlet 85aY to the outlet 85bY. The outlet 85bY of the discharge pipe 85Y is connected to the discharge port 430a1Y of the toner chamber 430cY. In other words, the discharge port 430a1Y of the toner chamber 430cY is configured to communicate with the interior of the toner chamber 430cY via the discharge pipe 85Y extending inside the toner chamber 430cY.

[0050] The discharge pipe 85Y is a passage through which the toner T contained in the toner chamber 430cY passes when it is moved toward the discharge outlet 430a1Y. The discharge pipe 85Y has a first portion 851Y having an inlet 85aY and extending in the third direction (Z direction), and a second portion 852Y having an outlet 85bY and extending in the first direction (X direction). The extension directions of the first portion 851Y and the second portion 852Y intersect (are perpendicular to each other). The outlet 85bY of the discharge pipe 85Y is connected to communicate with the discharge outlet 430a1Y. The inlet 85aY of the discharge pipe 85Y is positioned opposite, with a gap therebetween, a lowermost portion 83bY, which is a part of the filter 83Y. In other words, the filter 83Y has a concave shape such that the lowermost portion 83bY is positioned corresponding to the inlet 85aY of the discharge pipe 85Y. The inlet 85aY of the discharge pipe 85Y is preferably located close to the filter 83Y. When the amount of toner T remaining in the toner chamber 430cY becomes low, the toner T is fluidized by the compressed air received through the receiving port 430b1Y, moves along the slope of the filter 83Y, and collects at the bottom 83bY. The inlet 85aY of the discharge pipe 85Y can guide the toner T that has collected at the bottom 83bY of the filter 83Y to the discharge port 430a1Y. This allows the toner T to be efficiently discharged to the outside of the toner cartridge 430Y, even when the amount of toner contained in the toner chamber 430cY of the toner cartridge 430Y becomes low.

[0051] Toner cartridge 430 of this embodiment is structured to use compressed air to discharge toner to the outside of toner cartridge 430, eliminating the need for a rotating member such as a screw. Therefore, it is possible to create a cartridge with a simple structure with a small number of parts.

[0052] [Toner transport mechanism] The mechanism by which the toner contained in the toner chamber 430cY of the toner cartridge 430Y is transported to the developing unit PY will now be described. Compressed air discharged upward from the discharge port 80aY of the pump unit 80Y is received into the air chamber 430dY via the receiving port 430b1Y of the toner cartridge 430Y, as shown in FIG. 8(a). The compressed air then increases the air pressure in the air chamber 430dY, passes through the filter 83Y, and flows into the toner chamber 430cY. The compressed air that flows into the toner chamber 430cY penetrates between the particles of the toner T, fluidizing the toner T. The fluidized toner T mixed with the compressed air flows into the discharge pipe 85Y from the inlet 85aY by the compressed air that flows further into the air chamber 430dY via the receiving port 430b1Y. The toner T that has flowed into the discharge pipe 85Y is moved through the discharge pipe 85Y to the outlet 85bY, and is then discharged from the discharge port 430a1Y to the outside of the toner cartridge 430Y.

[0053] As in this embodiment, there is a highly sealed space between the discharge port 80aY and the filter 83Y. By providing the air chamber 430dY, the compressed air discharged from the discharge port 80aY is efficiently directed toward the filter 83Y without dispersing outside the toner cartridge 430Y. For example, if the toner cartridge 430Y is subjected to vibration or left unused for a long period of time, the toner T in the toner chamber 430cY may aggregate. In such a situation, high pressure may be required to pass the compressed air through the filter 83Y and into the toner chamber 430cY. Even in such a case, by continuing to send compressed air from the pump unit 80Y to the air chamber 430dY and increasing the pressure (air pressure) within the air chamber 430dY, it becomes possible to send the compressed air through the filter 83Y into the toner chamber 430cY. Furthermore, by providing the air chamber 430dY, the performance of the pump unit 80Y is sufficient as long as it can continue to send compressed air so that the pressure in the air chamber 430dY increases to a level sufficient to pass the compressed air from the filter 83Y into the toner chamber 430cY. Therefore, no special requirements are placed on the discharge speed or discharge amount of the pump unit 80Y, so a small pump unit can be used, which can contribute to the miniaturization of the device.

[0054] As shown in Figures 6(a) and 8(a), the toner T discharged from the discharge port 430a1Y of the toner cartridge 430Y passes through the receiving port 429aY of the toner cartridge holder 429 and enters the inside of the supply pipe 444Y from the upstream end 444uY. The toner T that has entered the inside of the supply pipe 444Y from the upstream end 444uY is moved to the downstream end 444dY by the compressed air that has flowed into the upstream end 444uY together with the toner T, and is replenished to the developing unit 9Y (developing container 3Y) of the process cartridge PY.

[0055] The toner supplied into the developing unit 9Y (developer container 3Y) from the end of the developing unit 9Y in the Y direction (second direction) is stirred and leveled in the toner storage chamber of the developing unit 9Y (developer container 3Y) by the stirring members SY1 and SY2 shown in FIG. 6(b). The stirring members SY1 and SY2 may be, for example, screws extending in the Y direction (second direction). That is, the stirring members SY1 and SY2 may be any members capable of transporting toner from the end (first end) of the developing unit 9Y on the side where the downstream end 444dY of the supply pipe 444Y is connected to the end (second end) of the developing unit 9Y on the opposite side.

[0056] Since not only toner T but also compressed air flows into the developing unit 9Y (developer container 3Y) from the supply pipe 444Y, the internal pressure within the developing unit 9Y tends to increase. Therefore, in this embodiment, as shown in FIG. 4, an exhaust filter portion PfY is provided on the upper surface of the developing unit 9Y. The exhaust filter portion PfY is a portion in which a through-hole is formed in a frame that forms the developing unit 9Y and a filter such as a nonwoven fabric is fitted in the through-hole. The toner T that flows into the developing unit 9Y from the supply pipe 444Y remains in the developing unit 9Y, while at least a portion of the compressed air is exhausted to the outside of the developing unit 9Y from the exhaust filter portion PfY. This suppresses an increase in the internal pressure within the developing unit 9Y, and facilitates the flow of toner T and compressed air from the toner cartridge 430Y into the developing unit 9Y via the supply pipe 444Y.

[0057] In this embodiment, the exhaust filter portion PfY is provided in the center of the developing unit 9Y in the Y direction (second direction). Like the exhaust filter PfaY, it may be provided at the end of the developing container 3Y on the side where the upstream end 444uY of the supply pipe 444Y is located in the Y direction (second direction). Also, like the exhaust filter PfbY, it may be provided at the end of the developing unit 9Y on the opposite side in the Y direction (second direction) to the end where the upstream end 444uY of the supply pipe 444Y is located. Also, the exhaust filter PfbY may be provided on the side of the developing unit 9Y instead of on the top surface thereof.

[0058] [Supply Pipe Configuration] The configuration of the supply pipe will be described with reference to Figures 1, 5, and 6(a). The toner discharged from the toner cartridge 430 together with the compressed air is received by a supply pipe 444Y through a receiving port 429aY provided in the toner cartridge holder 429. Each supply pipe 444 extends to and is connected to each developing unit 9. Each receiving port 429a, which can communicate with the discharge port 430a1Y, is a through-hole provided to penetrate the surface of the toner cartridge holder 429 facing the back surface of each toner cartridge 430. Each receiving port 429a opens in a direction (first direction) substantially along the X direction, which is the direction in which the developing units 9 are lined up. The opening direction of each receiving port 429a (429aY, 429aM, 429aC, 429aK) of the toner cartridge holder 429 intersects with the opening direction of each discharge port 80a of each pump unit 80.

[0059] 6(a), upstream ends 444uY, 444uM, 444uC, and 444uK of supply pipes 444 are connected to the rear side of the portion of toner cartridge holder 429 where each receiving port 429a is provided, so as to communicate with each receiving port 429a. Downstream ends 444dY, 444dM, 444dC, and 444dK of each supply pipe 444 are connected to the connection ports 900Y, 900M, 900C, and 900K, which are toner receiving ports in the developing units 9. The toner received through each receiving port 429a is moved inside each supply pipe 444 from each upstream end 444u to each downstream end 444d by compressed air discharged from each toner cartridge 430, and is supplied to each developing unit 9.

[0060] Next, we will explain the arrangement of each supply pipe 444. For convenience, the optical path L of the laser light from the laser scanner unit LB is visualized in Figures 1 and 5. The optical path L is the optical path of the laser light emitted from the laser scanner unit LB toward the photosensitive drums 4Y, 4M, 4C, and 4K, respectively.

[0061] 1, the supply pipes 444Y and 444M are provided so as to extend from the end of the LE side (one side in the second direction) of each process cartridge P in the Y direction (second direction), avoiding the optical paths L. The supply pipes 444C and 444K are provided so as to extend from the end of the RE side (the other side in the second direction) of each process cartridge P in the Y direction (second direction), avoiding the optical paths L.

[0062] The downstream end 444d of each supply pipe 444 is connected to the end of the toner storage portion 901Y of each developing unit 9 in the Y direction (second direction). Specifically, the downstream end 444dY of the supply pipe 444Y and the downstream end 444dM of the supply pipe 444M are connected to the LE side end of the developing unit Y and the LE side end of the developing unit M, respectively. The downstream end 444dC of the supply pipe 444C and the downstream end 444dK of the supply pipe 444K are connected to the RE side end of the developing unit C and the RE side end of the developing unit K, respectively.

[0063] Of the supply pipes 444, the supply pipe 444Y (first supply pipe) will be described. The supply pipe 444Y (first supply pipe) connects the toner cartridge 430Y and the developing unit 9Y. The toner cartridge 430Y is the toner cartridge 430 that is located closest to the first end face 721 in the Y direction (second direction) of both end faces (first end face 721, second end face 722; see FIG. 3, etc.) of the device main body 72 in the Y direction (second direction) of the toner cartridge 430. The supply pipe 444Y is also the supply pipe 444 that is located closest to the first end face 721 in the Y direction among the supply pipes 444. When viewed in the Z direction perpendicular to both the X direction (first direction) and the Y direction (second direction), the supply pipe 444Y (first supply pipe) is located outside the optical path L of the laser light from the laser scanner unit LB in the Y direction. The receiving opening 429aY of the toner cartridge holder 429 and the connection opening 900Y of the developing unit 9 are aligned in the direction in which the toner cartridges 430 are arranged (Y direction). The connecting port 900Y and the discharging port 430a1Y of the toner cartridge 430Y are located at the same position in the Z direction (first direction) and at approximately the same height in the Z direction (third direction). That is, the connecting port 900Y of the developing unit 9 is disposed opposite the discharging port 430a1Y of the toner cartridge 430Y in the alignment direction (first direction) of the process cartridges P. The connecting port 900Y and the discharging port 430a1Y each open in the alignment direction (first direction) of the process cartridges P, and are positioned so as to overlap each other when viewed in the same direction but not overlap with the optical path L of the laser light of the laser scanner unit LB. Furthermore, at least a portion of the receiving port 429aY (first communication port) of the toner cartridge holder 429 also overlaps with the connecting port 900Y (first receiving port) of the developing unit 9Y when viewed in the alignment direction (first direction) of the process cartridges P (see FIGS. 10 and 11(a)).

[0064] FIG. 10 is a schematic plan view (viewed in the Z direction) of the image forming apparatus 1 according to this embodiment, showing the layout of the apparatus main body 72, process cartridges PY and PK, toner cartridges 430Y and 430K, and supply pipes 444Y and 444K. Components not required for explanation are omitted. FIG. 11(a) is a schematic side view (viewed in the Y direction) of the image forming apparatus 1 according to this embodiment, showing an enlarged view of only the configuration around the supply pipe 444Y. FIG. 11(b) is a schematic side view (viewed in the Y direction) of the image forming apparatus 1 according to this embodiment, showing an enlarged view of only the configuration around the supply pipe 444K. In Fig. 10, as indicated by auxiliary lines Lw1 and Lw2 extending along the alignment direction (first direction) of the process cartridges P, the discharge port 430a1Y, the receiving port 429aY, and the connection port 900Y are arranged to at least partially overlap each other when viewed in the alignment direction (first direction). Also, in Fig. 11(a), auxiliary lines Lh1 and Lh2 are lines extending along the alignment direction (first direction) of the process cartridges P, with the auxiliary line Lh1 being a line passing through the lower end of the connection port 900Y and the auxiliary line Lh2 being a line passing through the upper end of the connection port 900Y. As indicated by auxiliary lines Lh1 and Lh2, the discharge port 430a1Y, the receiving port 429aY, and the connection port 900Y are arranged to at least partially overlap each other when viewed in the alignment direction (first direction).

[0065] The overlapping configuration described above allows the toner supply path from the receiving port 429aY (first communication port) of the toner cartridge holder 429 to the connecting port 900Y (first receiving port) of the developing unit 9Y to be configured as a path with minimal pressure loss. Furthermore, the supply pipe 444Y can be arranged to extend substantially linearly between the discharge port 430a1Y (first discharge port) and the connecting port 900Y (first receiving port) when viewed from a direction perpendicular to the alignment direction (first direction) of the process cartridges P, which is substantially along the X direction. Therefore, the supply pipe 444Y has no bends and forms a substantially linear (straight) toner transport path. This reduces pressure loss when transporting the toner T using compressed air, thereby achieving stable toner supply. The supply pipe 444Y does not necessarily have to be a straight pipe; for example, a flexible tubular pipe may be used. When the latter pipe is used, some bending may occur between the receiving port 429aY (first communication port) and the connection port 900Y (first receiving port), but the above-mentioned overlap configuration reduces the difference in height between the inlet and outlet, and the above-mentioned pressure loss reduction effect can be fully obtained.

[0066] Of the supply pipes 444, supply pipes 444M and 444C (second supply pipes) will be described. Supply pipes 444M and 444C are pipes that are at least partially bent. Supply pipe 444M connects discharge port 430a1M (second discharge port) of toner cartridge 430M (second developer container) to connection port 900M (second receiving port) of development unit 9M (second main body housing portion). Supply pipe 444C connects discharge port 430a1C (second discharge port) of toner cartridge 430C (second developer container) to connection port 900C (second receiving port) of development unit 9C (second main body housing portion).

[0067] The discharge ports 430a1M, 430a1C and the connection ports 900M, 900C are positioned at offset positions (different positions) from each other in the Y direction (second direction). The discharge ports 430a1M, 430a1C and the connection ports 900M, 900C each open in the alignment direction of the process cartridges P (first direction), but are positioned so as not to overlap with each other when viewed in the same direction. Furthermore, when viewed in the same direction, at least the connection ports 900M, 900C are positioned so as not to overlap with each other with respect to the optical path L of the laser light from the laser scanner unit LB. Therefore, the supply pipes 444M, 444C each include a first portion extending substantially along the X direction or the first direction, and a second portion extending substantially along the Y direction or the second direction, so that the extension direction of the toner transport path changes. In the toner transport path formed by the supply pipes 444M and 444C, the first portion forms the downstream toner transport path, and the second portion forms the upstream toner transport path.

[0068] Furthermore, first portions of the supply pipes 444M and 444C that extend in a direction substantially along the X direction or the first direction are parallel to each other and also to the supply pipe 444Y. As shown in Figures 6(a) and 6(b), when viewed in the Y direction (second direction), the first portions of the supply pipes 444M and 444C are hidden behind the supply pipe 444Y.

[0069] Of the supply pipes 444, supply pipe 444K will be described. Supply pipe 444K (second supply pipe) connects toner cartridge 430K and development unit 9K. Of the toner cartridges 430, toner cartridge 430K is the toner cartridge 430 that is provided at a position closest to the second end face 722 in the Y direction (second direction) of both end faces (first end face 721, second end face 722; see FIG. 3, etc.) of device main body 72. Supply pipe 444K is the supply pipe 444 that is provided at a position closer to the second end face 722 in the Y direction than the first end face 721.

[0070] Similar to the supply pipe 444Y, the supply pipe 444K extends in a substantially straight line between the discharge port 430a1K (second discharge port) of the toner cartridge 430K (second developer container) and the connection port 900K (second receiving port) of the developing unit 9K (second main body housing portion). However, the extension direction of the supply pipe 444K is different from that of the supply pipe 444Y. That is, as shown in FIG. 4(b), the receiving port 429aK of the toner cartridge holder 429 is positioned higher in the Z direction (third direction) than the other receiving ports 429aY, 429aM, and 429aC. Correspondingly, the discharge port 430a1K of the toner cartridge 430K is positioned higher in the Z direction (third direction) than the discharge ports 430a1Y, 430a1M, and 430a1C of the other toner cartridges 430Y, 430M, and 430C. On the other hand, the connection port 900K of the developing unit 9K is provided at the same height in the Z direction (third direction) as the connection ports 900Y, 900M, and 900C of the other developing units 9Y, 9M, and 9C when viewed in the line-up direction (first direction) of the process cartridges P. Therefore, when viewed in the line-up direction (second direction) of the toner cartridges 430, it is provided so as to extend in a direction angled with respect to the line-up direction (first direction) of the process cartridges P. As shown in FIGS. 6(a) and 6(b), the supply pipe 444K is configured to extend in directions that intersect with the first portions of the supply pipes 444M and 444C and the supply pipe 444Y when viewed in the Y direction (second direction).

[0071] 10, as shown by auxiliary lines Lw3 and Lw4 extending along the alignment direction (first direction) of the process cartridges P, the discharge port 430a1K, the receiving port 429aK, and the connection port 900K are arranged so as to at least partially overlap one another when viewed in the alignment direction. Also, in FIG. 11(b), auxiliary lines Lh3 and Lh4 are lines extending along the alignment direction (first direction) of the process cartridges P, with the auxiliary line Lh3 being a line passing through the lower end of the connection port 900K and the auxiliary line Lh4 being a line passing through the upper end of the connection port 900K. As shown by auxiliary lines Lh3 and Lh4, as shown by auxiliary lines Lh3 and Lh4, the discharge port 430a1K, the receiving port 429aK, and the connection port 900K are arranged so as to at least partially overlap one another when viewed in the alignment direction (first direction). 30a1K, receiving port 429aK, and connection port 900K are arranged so as to at least partially overlap one another.

[0072] As shown in FIGS. 1, 6(a), and 6(b), the supply pipe 444K extends from the toner cartridge holder 429, passing above the second portion (the portion extending in the Y direction (second direction)) of the supply pipe 444C, to the connection port 900M of the developing unit 9M. More specifically, the upstream end 444uK of the supply pipe 444K is located above the second portion of the supply pipe 444C. Therefore, as shown in FIG. 1, when viewed in the Z direction, the supply pipe 444K and the second portion of the supply pipe 444C are arranged to intersect with each other.

[0073] Furthermore, the supply pipe 444K is the supply pipe with the shortest toner transport path length among the four supply pipes 444. The direction in which the supply pipe 444K extends is a downward direction inclined downward with respect to the horizontal direction (X direction). In other words, the toner transport path formed by the supply pipe 444K is a path that descends from the upstream side to the downstream side, and it is possible to transport toner from the toner cartridge 430K to the developing unit 9K by utilizing the toner's own weight. This toner transport path is particularly advantageous for toner cartridge 430K, which is replenished relatively frequently and has a large toner capacity.

[0074] The supply pipe 444Y connects the developing unit 9Y that is the farthest from the toner cartridge 430 in the first direction among the developing units 9, to the toner cartridge 430Y that is the endmost toner cartridge 430 in the second direction among the toner cartridges 430. The supply pipe 444K connects the developing unit 9K that is the closest to the toner cartridge 430 in the first direction among the developing units 9, to the toner cartridge 430K that is the endmost toner cartridge 430 in the second direction among the toner cartridges 430. In this embodiment, the supply pipes 444Y and 444K are only supply pipes that extend linearly (first supply pipes), but this is not limited to this. For example, depending on the arrangement of the toner cartridges 430 in the Y direction (second direction), the supply pipes 444M and 444C that connect the developing units 9M and 9C to the toner cartridges 430M and 430C may also be supply pipes that extend linearly (first supply pipes).

[0075] As described above, the supply pipe 444 connecting the toner cartridge 430 and the developing unit 9 is provided at the end of the developing unit 9 in the Y direction (second direction) away from the light path L, and is made to be approximately straight when viewed from a direction approximately perpendicular to the X direction (first direction). This reduces pressure loss when transporting the toner T using compressed air, making it possible to achieve a stable supply of toner.

[0076] Although the receiving opening 429aY of the toner cartridge holder 429 and the connection opening 900Y of the developing unit 9 are described as being at the same position in the Y direction (second direction), this is not necessarily the case. Even if they are misaligned in the second direction, pressure loss can be reduced by connecting the receiving opening 429Y and the connection opening 900Y in a substantially straight line (a straight line in a direction slightly inclined with respect to the X direction (first direction)) while avoiding the optical path. Also, although they are described as being at the same height in the Z direction (third direction), this is not necessarily the case. Even if they are at different heights, pressure loss can be reduced by connecting the receiving opening 429Y and the connection opening 900Y in a substantially straight line.

[0077] The disclosure of the embodiments of the present invention includes the following configurations. (Configuration 1) An image forming apparatus for forming an image on a recording material, a plurality of developing units aligned in a first direction, the plurality of developing units including a first photosensitive drum and a first developing unit provided with a first receiving port and having a first developing roller that supplies developer received through the first receiving port to the first photosensitive drum; an apparatus body having an air supply unit; a first developer container that contains a developer and is provided with a first discharge port, the first developer container being detachable from the device main body, and a plurality of developer containers that are aligned in a second direction perpendicular to the first direction; Equipped with The device body includes: a mounting portion to which the plurality of developer containers can be detachably attached, the mounting portion being provided with a first communication port that can communicate with the first discharge port; a plurality of pipes through which the developer conveyed from the plurality of developer containers to the corresponding plurality of developing units by air supplied from the air supply unit passes, the plurality of pipes including a first pipe extending from the first communication port to the first receiving port and through which the developer discharged from the first discharge port passes; and When one end surface and the other end surface of the device body in the second direction are a first end surface and a second end surface, the first developer container is provided at a position among the plurality of developer containers closest to the first end surface in the second direction, the first pipe is provided at a position among the plurality of pipes closest to the first end face in the second direction, When viewed in the first direction, at least a portion of the first communication port overlaps with the first receiving port. An image forming apparatus characterized by: (Configuration 2) 2. The image forming apparatus according to claim 1, wherein the first pipe extends linearly from the first communication port to the first receiving port. (Configuration 3) When viewed in the first direction, at least a portion of the first communication port overlaps with the first discharge port. 3. The image forming apparatus according to claim 1, wherein: (Configuration 4) the plurality of developing units includes a second developing unit provided with a second receiving port; the plurality of developer containers include a second developer container that contains a developer and is provided with a second discharge port and is detachable from the apparatus main body, The mounting portion is provided with a second communication port that communicates with the second discharge port, the plurality of pipes include a second pipe extending from the second communication port to the second receiving port, through which the developer discharged from the second discharge port passes; the second developer container is provided at a position among the plurality of developer containers that is closest to the second end face in the second direction, the second pipe is provided at a position closer to the second end face than to the first end face in the second direction, When viewed in the first direction, at least a portion of the second communication port overlaps with the second receiving port. 4. The image forming apparatus according to any one of configurations 1 to 3. (Configuration 5) When viewed in the first direction, at least a portion of the second communication port overlaps with the second discharge port. 5. The image forming apparatus according to configuration 4. (Configuration 6) 6. The image forming apparatus according to configuration 4 or 5, wherein the second pipe extends linearly from the second communication port to the second receiving port. (Configuration 7) the second developing unit is located closer to the plurality of developer containers than the first developing unit in the first direction; The second pipe is shorter than the first pipe. 7. The image forming apparatus according to any one of configurations 4 to 6. (Configuration 8) the first developing unit is the farthest from the plurality of developer containers in the first direction among the plurality of developing units; 8. The image forming apparatus according to any one of configurations 1 to 7. (Configuration 9) the plurality of developing units includes a second developing unit provided with a second receiving port; the plurality of developer containers include a second developer container that contains a developer and is provided with a second discharge port and is detachable from the device main body; The mounting portion is provided with a second communication port that communicates with the second discharge port, the plurality of pipes include a second pipe extending from the second communication port to the second receiving port, through which the developer discharged from the second discharge port passes; the second developer container is provided at a position closer to a center between the first end surface and the second end surface in the second direction than the first developer container, the second communication port is provided at a position different from the second receiving port in the second direction and at a position not overlapping with the second receiving port when viewed in the first direction, At least a portion of the second pipe is bent. 4. The image forming apparatus according to any one of configurations 1 to 3. (Configuration 10) the second developing unit is located closer to the plurality of developer containers than the first developing unit in the first direction; 10. The image forming apparatus according to configuration 9, (Configuration 11) the apparatus main body includes a laser scanner that irradiates a laser onto the surface of the first photosensitive drum, the first pipe is provided outside the optical path of the laser in the second direction. 11. The image forming apparatus according to any one of configurations 1 to 10. (Configuration 12) the first communication port and the first receiving port are located at positions that do not overlap with the optical path when viewed in the first direction; 12. The image forming apparatus according to claim 11, (Configuration 13) The first developer container is a developer storage chamber that stores a developer and is provided with the first discharge port; a filter that allows air to pass through but prevents developer from passing through; an air chamber separated from the developer accommodating chamber by the filter and having an air intake port for receiving air supplied from the air supply unit; having 13. The image forming apparatus according to any one of configurations 1 to 12. (Configuration 14) the air inlet is provided so as to open on a surface of the developer container excluding a surface facing the second direction. 14. The image forming apparatus according to claim 13, (Configuration 15) The developer storage chamber and the air chamber are arranged in a third direction intersecting both the first direction and the second direction. are aligned in the direction 15. The image forming apparatus according to claim 13 or 14. (Configuration 16) the third direction is the direction of gravity, the air chamber is located below the developer storage chamber, the discharge port is configured to communicate with the inside of the developer storage chamber via a discharge pipe provided inside the developer storage chamber, an opening of the discharge pipe that opens into the developer storage chamber faces the filter; 16. The image forming apparatus according to claim 15, wherein the filter has a concave shape that is most concave downward in a region facing the opening of the discharge pipe. (Configuration 17) The second pipe includes a first portion extending in the first direction and a second portion extending in the second direction. 11. The image forming apparatus according to configuration 9 or 10. (Configuration 18) the first developer container is detachable from the mounting portion in the first direction; 18. The image forming apparatus according to any one of configurations 1 to 17. [Explanation of symbols]

[0078] 1: image forming apparatus, 3: developer container, 9: developer unit, 29: cartridge holder, 429a: receiving port, 430: toner cartridge, 444: supply pipe, 80: pump unit, 83: filter, 85: discharge pipe, 85a: inlet (first opening), 85b: outlet (second opening), 900: connection port, 901: toner storage section, L: laser optical path, LB: laser scanner unit, P: process cartridge

Claims

1. An image forming apparatus for forming an image on a recording material, an apparatus body including a plurality of photosensitive drums including a first photosensitive drum, a first developing unit provided with a first receiving port and having a first developing roller that supplies developer received from the first receiving port to the first photosensitive drum, the plurality of developing units being aligned in a first direction, and an air supply unit; a first developer container that contains a developer and is provided with a first discharge port, the first developer container being detachable from the device main body, and a plurality of developer containers that are aligned in a second direction perpendicular to the first direction; Equipped with The device body includes: a mounting portion to which the plurality of developer containers are detachably attached, the mounting portion being provided with a first communication port that can communicate with the first discharge port; a plurality of pipes through which the developer conveyed from the plurality of developer containers to the corresponding plurality of developing units by air supplied from the air supply unit passes, the plurality of pipes including a first pipe extending from the first communication port to the first receiving port and through which the developer discharged from the first discharge port passes; and When one end surface and the other end surface of the device body in the second direction are a first end surface and a second end surface, the first developer container is provided at a position among the plurality of developer containers closest to the first end surface in the second direction, the first pipe is provided at a position among the plurality of pipes closest to the first end surface in the second direction, When viewed in the first direction, at least a portion of the first communication port overlaps with the first receiving port. An image forming apparatus characterized by:

2. 2. The image forming apparatus according to claim 1, wherein the first pipe extends linearly from the first communication port to the first receiving port.

3. When viewed in the first direction, at least a portion of the first communication port overlaps with the first discharge port.

2. The image forming apparatus according to claim 1, wherein the image forming apparatus is a recording medium.

4. the plurality of developing units includes a second developing unit provided with a second receiving port; the plurality of developer containers include a second developer container that contains a developer and is provided with a second discharge port and is detachable from the device main body, The mounting portion is provided with a second communication port that communicates with the second discharge port, the plurality of pipes include a second pipe extending from the second communication port to the second receiving port, through which the developer discharged from the second discharge port passes; the second developer container is provided at a position among the plurality of developer containers that is closest to the second end surface in the second direction, the second pipe is provided at a position closer to the second end face than to the first end face in the second direction, When viewed in the first direction, at least a portion of the second communication port overlaps with the second receiving port.

2. The image forming apparatus according to claim 1, wherein the image forming apparatus is a recording medium.

5. When viewed in the first direction, at least a portion of the second communication port overlaps with the second discharge port.

5. The image forming apparatus according to claim 4.

6. 5. The image forming apparatus according to claim 4, wherein the second pipe extends linearly from the second communication port to the second receiving port.

7. the second developing unit is located closer to the plurality of developer containers than the first developing unit in the first direction; The second pipe is shorter than the first pipe.

5. The image forming apparatus according to claim 4.

8. the first developing unit is the farthest from the plurality of developer containers in the first direction among the plurality of developing units; 2. The image forming apparatus according to claim 1, wherein the image forming apparatus is a recording medium.

9. the plurality of developing units includes a second developing unit provided with a second receiving port; the plurality of developer containers include a second developer container that contains a developer and is provided with a second discharge port and is detachable from the device main body, The mounting portion is provided with a second communication port that communicates with the second discharge port, the plurality of pipes include a second pipe extending from the second communication port to the second receiving port, through which the developer discharged from the second discharge port passes; the second developer container is provided at a position closer to a center between the first end surface and the second end surface in the second direction than the first developer container, the second communication port is provided at a position different from the second receiving port in the second direction and at a position not overlapping with the second receiving port when viewed in the first direction, At least a portion of the second pipe is bent.

2. The image forming apparatus according to claim 1, wherein the image forming apparatus is a recording medium.

10. the second developing unit is located closer to the plurality of developer containers than the first developing unit in the first direction; 10. The image forming apparatus according to claim 9,

11. the apparatus main body includes a laser scanner that irradiates a laser onto the surface of the first photosensitive drum, the first pipe is provided outside an optical path of the laser in the second direction; 2. The image forming apparatus according to claim 1, wherein the image forming apparatus is a recording medium.

12. the first communication port and the first receiving port are located at positions that do not overlap with the optical path when viewed in the first direction; 12. The image forming apparatus according to claim 11.

13. The first developer container is a developer storage chamber that stores developer and is provided with the first discharge port; a filter that allows air to pass through but prevents developer from passing through; an air chamber separated from the developer accommodating chamber by the filter and provided with an air intake port for receiving air supplied from the air supply unit; having 2. The image forming apparatus according to claim 1, wherein the image forming apparatus is a recording medium.

14. the air inlet is provided so as to open on a surface of the developer container excluding a surface facing the second direction; 14. The image forming apparatus according to claim 13.

15. the developer storage chamber and the air chamber are aligned in a third direction that intersects both the first direction and the second direction; 14. The image forming apparatus according to claim 13.

16. the third direction is the direction of gravity, the air chamber is located below the developer storage chamber, the discharge port is configured to communicate with the inside of the developer storage chamber via a discharge pipe provided inside the developer storage chamber, an opening of the discharge pipe that opens into the developer storage chamber faces the filter; 16. The image forming apparatus according to claim 15, wherein the filter has a concave shape that is most concave downward in a region facing the opening of the discharge pipe.

17. The second pipe includes a first portion extending in the first direction and a second portion extending in the second direction.

10. The image forming apparatus according to claim 9,

18. the first developer container is detachable from the mounting portion in the first direction; 2. The image forming apparatus according to claim 1, wherein the image forming apparatus is a recording medium.

Images