Image forming apparatus

Abstract

In a developing unit where toner is supplied from a toner supply container via a toner supply pipe, the toner supply position of each developing unit is changed along the length of the developing roller to reduce the size of the main unit, thereby reducing the number of dedicated parts that make up the developing unit. [Solution] The first developing container is a first frame that forms a first space for containing a first toner, and includes a first frame with a first through-hole and a second through-hole; the second developing container is a second frame that forms a second space for containing a second toner, and has the same shape as the first frame, and includes a second frame with a third through-hole and a fourth through-hole corresponding to the first through-hole and the second through-hole, respectively; the other end of the first passage communicates with the first space of the first developing container via the first through-hole; the other end of the second passage communicates with the second space of the second developing container via the fourth through-hole; and the second and third through-holes are sealed.

Description

Technical Field

[0001] The present invention relates to an image forming apparatus using an electrophotographic method.

Background Art

[0002] In an electrophotographic color image forming apparatus, a configuration is known in which a conveyance mechanism using air is provided in the image forming apparatus to convey toner to a developing container in the image forming apparatus. Patent Document 1 discloses a configuration in which air supplied from a pump is mixed with toner and conveyed to a developing container.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In a developing unit in which toner is supplied from a toner supply container via a toner supply pipe, there may be a case where it is desired to change the toner supply position of each developing unit in the longitudinal direction of the developing roller. For example, when it is desired to configure the toner supply pipe to be as short as possible. Suppose the toner supply position in the developing unit is determined according to the position of the end of the toner supply pipe for each toner color. Then, the positions of the toner supply ports provided in the developing unit are different for each toner color. Then, a plurality of dedicated parts are required for each toner color to be written on the developing unit. This is because the shape of the toner storage container of the developing unit is different for each toner color. If the toner storage container of the developing unit is a resin part formed by injection molding, it is necessary to use different molds for each toner color. The need for dedicated parts for each toner color makes production management complicated, so it is desirable to minimize the number of dedicated parts.

[0005] Therefore, the present invention aims to reduce the number of specialized parts that make up the developing unit. [Means for solving the problem]

[0006] To achieve the above objective, the configuration of the image forming apparatus of this application is a first developing unit having a first toner container that contains a first toner and is provided with a first outlet for discharging the first toner outside the first toner container, a second toner container that contains a second toner and is provided with a second outlet for discharging the second toner outside the second toner container, a first developing unit having a first developing container configured to contain the first toner and a first developing roller configured to carry the first toner contained in the first developing container, a second developing unit having a second developing container configured to contain the second toner and a second developing roller configured to carry the second toner contained in the second developing container, and a first passage having one end communicating with the first outlet of the first toner container and the other end communicating with the first developing container, which transports the first toner discharged from the first outlet toward the first developing container. The invention provides a first passage for transporting the second toner discharged from the second toner container toward the second developing container, the second passage having one end communicating with the second discharge port of the second toner container and the other end communicating with the second developing container, wherein the first developing container is a first frame that forms a first space for containing the first toner, and includes a first through-hole and a second through-hole, the second developing container is a second frame that forms a second space for containing the second toner and has the same shape as the first frame, and includes a third through-hole and a fourth through-hole corresponding to the first through-hole and the second through-hole, respectively, the other end of the first passage communicates with the first space of the first developing container via the first through-hole, the other end of the second passage communicates with the second space of the second developing container via the fourth through-hole, and the second through-hole and the third through-hole are sealed. [Effects of the Invention]

[0007] According to the present invention, in an image forming apparatus that transports toner by means of air or a screw, the number of dedicated parts constituting the developing unit can be reduced. [Brief explanation of the drawing]

[0008] [Figure 1] These are a top view and a front view of the developing unit according to the first embodiment. [Figure 2] This is a cross-sectional view of an image forming apparatus according to the first embodiment. [Figure 3] This is a perspective view of an image forming apparatus according to the first embodiment. [Figure 4] This is a perspective view of the image forming unit according to the first embodiment. [Figure 5] This is a perspective view of the image forming unit according to the first embodiment (with laser beam path diagram). [Figure 6] This is a top view of an image forming unit and a laser scanner according to the first embodiment. [Figure 7] This is a cross-sectional view perpendicular to the rotation axis of the drum of the image forming unit and laser scanner according to the first embodiment. [Figure 8] This is a cross-sectional view parallel to the rotation axis of the drum of the image forming unit and laser scanner according to the first embodiment. [Figure 9] This is a perspective view of the image forming unit in a state extended from the main body of the apparatus, according to the first embodiment. [Figure 10] These are front view, top view, bottom view, side view, and rear view of the cartridge according to the first embodiment. [Figure 11] These are cross-sectional and exploded perspective views of the cartridge according to the first embodiment. [Figure 12] These are cross-sectional and exploded perspective views of the cartridge according to the first embodiment. [Figure 13] These are exploded perspective and perspective views of the developing unit according to the first embodiment. [Figure 14] This is a perspective view of a process cartridge according to the first embodiment. [Figure 15]Perspective view of the relay member according to the first embodiment. [Figure 16] Exploded perspective view and perspective view of the developing unit according to the first embodiment. [Figure 17] Perspective view of the sealing cap according to the first embodiment. [Figure 18] Exploded perspective view and perspective view of the developing unit according to the first embodiment. [Figure 19] Exploded perspective view and perspective view of the developing unit according to the first embodiment. [Figure 20] Perspective view of the image forming unit according to the first embodiment (with laser optical path shown). [Figure 21] Top view of the image forming unit according to the first embodiment (with laser optical path shown). [Figure 22] Top view and front view of the developing unit according to the second embodiment. [Figure 23] Exploded perspective view and perspective view of the developing unit according to the second embodiment. [Figure 24] Perspective view of the developing unit according to the second embodiment. [Figure 25] Perspective view of the developing unit according to the second embodiment. [Figure 26] Perspective view of the developing unit according to the second embodiment. [Figure 27] Top view and front view of the relay member according to the second embodiment. [Figure 28] Top view and front view of the developing unit according to the third embodiment. [Figure 29] Exploded perspective view and perspective view of the developing unit according to the third embodiment. [Figure 30] Side view of the developing unit according to the first embodiment. [Figure 31] Schematic side view of the developing unit according to the first embodiment. <目标语言文本>

Mode for Carrying Out the Invention

[0009] <First Embodiment> (Image forming apparatus) An image forming apparatus 1 according to the first embodiment of the present invention will be described with reference to Figure 2. The electrophotographic image forming apparatus of this embodiment is a full-color image forming apparatus equipped with four color process units. Figure 2 is a main cross-section of the image forming apparatus 1.

[0010] Image forming apparatus 1 is a full-color laser printer using an electrophotographic process, and is capable of forming full-color images on a recording medium S. Image forming apparatus 1 comprises process units PY, PM, PC, and PK (hereinafter referred to as each process unit P; the YMCK at the end of each code represents the toner color. Y represents yellow, M represents magenta, C represents cyan, and K represents black. The same applies to process units other than P), and the apparatus body 72. Each process unit P is arranged to align in a first direction X, and the toner colors contained inside are different from each other. The longitudinal direction of the process unit P is a second direction Y perpendicular to the first direction. Process units PY, PM, PC, and PK are referred to as the first process unit, second process unit, third process unit, and fourth process unit, respectively.

[0011] Each process unit P has an electrophotographic process element. Rotational driving force is transmitted to the process unit P from the drive output section (not shown) of the apparatus body 72, and a bias voltage (charging bias, development bias, etc.) is supplied from the bias application section (not shown) of the apparatus body 72.

[0012] As shown in Figure 2, each process unit P, consisting of a drum unit and a developing unit, is equipped with drum units 8Y, 8M, 8C, and 8K (hereinafter referred to as each drum unit 8). Each drum unit 8 has a photosensitive drum 4Y, 4M, 4C, and 4K (hereinafter referred to as each photosensitive drum 4) and charging rollers 5Y, 5M, 5C, and 5K (hereinafter referred to as each charging roller 5) as process means that act on the photosensitive drum 4. Each photosensitive drum 4 is arranged so that the direction of its rotation axis is in the second direction Y. The photosensitive drums 4Y, 4M, 4C, and 4K are referred to as the first photosensitive drum, second photosensitive drum, third photosensitive drum, and fourth photosensitive drum, respectively.

[0013] Each process unit P comprises developing units 9Y, 9M, 9C, 9K (hereinafter referred to as each developing unit 9), each having developing rollers 6Y, 6M, 6C, 6K (hereinafter referred to as each developing roller 6) for developing the electrostatic latent image on the corresponding photosensitive drum 4. Each developing unit 9 is aligned along a first direction X. The developing rollers 6Y, 6M, 6C, 6K are designated as the first developing roller, second developing roller, third developing roller, and fourth developing roller, respectively. The developing units 9Y, 9M, 9C, 9K are designated as the first developing unit, second developing unit, third developing unit, and fourth developing unit, respectively.

[0014] The developing unit 9Y has a developing container 3Y (first developing container) which serves as a toner container for holding yellow (Y) toner (first toner), and is configured so that yellow (Y) toner is supplied to the surface of the photosensitive drum 4Y by a developing roller 6Y that carries the yellow (Y) toner. The developing unit 9M has a developing container 3M (second developing container) which holds magenta (M) toner (second toner), and is configured so that magenta (M) toner is supplied to the surface of the photosensitive drum 4M by a developing roller 6M that carries the magenta (M) toner. The developing unit 9C has a developing container 3C (third developing container) which holds cyan (C) toner (third toner), and is configured so that cyan (C) toner is supplied to the surface of the photosensitive drum 4C by a developing roller 6C that carries the cyan (C) toner. The developing unit 9K has a developing container 3K (fourth developing container) that contains black (K) toner (fourth toner), and is configured so that the black (K) toner is supplied to the surface of the photosensitive drum 4K by a developing roller 6K that carries the black (K) toner.

[0015] In the third direction Z, which is the direction of gravity intersecting both the first direction X and the second direction Y, a laser scanner unit LB (exposure unit) is provided above the process unit P (photosensitive drum 4). This laser scanner unit LB outputs laser light corresponding to image information. Hereafter, the optical paths of the laser light directed towards the photosensitive drums 4Y, 4M, 4C, and 4K will be referred to as optical paths LY, LM, LC, and LK (hereinafter referred to as each optical path L or optical path L). The laser light then passes through the 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 instead of the laser scanner unit LB.

[0016] In the third direction Z, an intermediate transfer belt unit 11 is provided below the process unit P as a transfer member. This intermediate transfer belt unit 11 has a drive roller 14, a tension roller 13, and an assist roller 15, and a flexible transfer belt 12 is stretched across it.

[0017] Each photosensitive drum 4 has its lower surface in contact with the upper surface of the transfer belt 12. The contact area between each photosensitive drum 4 and the transfer belt 12 is the primary transfer section 30Y, 30M, 30C, 30K (hereinafter referred to as the primary transfer section 30). Inside the transfer belt 12, primary transfer rollers 16Y, 16M, 16C, 16K (hereinafter referred to as the transfer rollers 16) are provided facing the photosensitive drum 4.

[0018] The drive roller 14 is pressed by the secondary transfer roller 17 via the transfer belt 12. The contact area between the transfer belt 12 and the secondary transfer roller 17 is the secondary transfer section 31.

[0019] In the third direction Z, a feeding unit 18 is provided below the intermediate transfer belt unit 11. The feeding unit 18 includes a paper feed tray 19 for loading and storing recording media S, and a paper feed roller 20 for picking up and transporting the recording media S from the paper feed tray 19.

[0020] In Figure 2, the upper part of the main body 72 of the device is provided with a fixing unit 21 for fixing the toner image onto the recording medium S, and an ejection roller 22 for ejecting the recording medium S with the toner image fixed onto it to the ejection tray 23. The ejection roller 22 ejects the recording medium S in a direction along the first direction X. In this embodiment, the downstream side of the ejection direction in which the recording medium S is ejected toward the ejection tray 23 by the ejection roller 22 is considered the front side of the image forming apparatus 1, and the upstream side of the ejection direction is considered the rear side of the image forming apparatus 1.

[0021] (Image formation process) The image forming operation for creating a full-color image is as follows: Each photosensitive drum 4 is driven to rotate counterclockwise at a predetermined speed in Figure 2. The transfer belt 12 is driven to rotate in the forward direction of the rotation of each photosensitive drum 4 (in the direction of arrow C in Figure 2) at a speed corresponding to the rotation speed of each photosensitive drum 4.

[0022] The laser scanner unit LB is also driven. Each charging roller 5, in synchronization with the driving of the laser scanner unit LB, uniformly charges the surface of each corresponding photosensitive drum 4 in each process unit P 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 according to the image signal of each color. This forms an electrostatic latent image on the surface of each photosensitive drum 4 corresponding to the image signal of each color. In this way, the laser scanner unit LB exposes the photosensitive drum 4Y and the photosensitive drum 4M, and a first electrostatic latent image and a second electrostatic latent image are formed on the photosensitive drum 4Y and the photosensitive drum 4M, respectively. Similarly, the laser scanner unit LB exposes the photosensitive drum 4C and the photosensitive drum 4K, and a third electrostatic latent image and a fourth electrostatic latent image are formed on the photosensitive drum 4C and the photosensitive drum 4K, respectively.

[0023] The electrostatic latent image on each photosensitive drum 4 is developed by supplying toner to each photosensitive drum 4 by each developing roller 6, which is driven to rotate clockwise at a predetermined speed as shown in Figure 2.

[0024] Through the electrophotographic image formation process described above, a yellow toner image is formed on the photosensitive drum 4Y of the process unit PY. This yellow toner image is then primary transferred onto the transfer belt 12.

[0025] Similarly, in the case of magenta, a magenta toner image is formed on the photosensitive drum 4M of the process unit PM. Then, the magenta toner image is primary transferred onto the transfer belt 12 so as to be superimposed on the yellow toner image on the transfer belt 12.

[0026] Similarly, a cyan toner image is formed on the photosensitive drum 4C of the process unit PC in the case of cyan. The cyan toner image is then primary transferred onto the transfer belt 12 so as to be superimposed on the yellow and magenta toner images on the transfer belt 12.

[0027] Similarly, for the black color, a black toner image is formed on the photosensitive drum 4K of the process unit PK. Then, the black toner image is primary transferred onto the transfer belt 12 so as to be superimposed on the yellow, magenta, and cyan toner images on the transfer belt 12.

[0028] In this way, a full-color image of unfixed toner in four colors—yellow, magenta, cyan, and black—is formed on the transfer belt 12.

[0029] Meanwhile, at a predetermined control timing, the recording media S are separated one by one from the paper tray 19 by the paper feed roller 20 and fed. At a predetermined control timing, the recording media S are introduced into the secondary transfer section 31, which is the contact point between the secondary transfer roller 17 and the transfer belt 12. As the recording media S is transported in the secondary transfer section 31, the four-color superimposed toner image on the transfer belt 12 is transferred to the recording media S. The recording media S on which the toner image has been transferred is heated and pressurized by the fixing unit 21, and the toner image is fixed to the recording media S. The recording media S on which the toner image has been fixed is discharged into the discharge tray 23 by the discharge roller 22.

[0030] The image forming apparatus 1 has cartridges 430Y, 430M, 430C, and 430K, which serve as toner replenishment containers that can be attached to the apparatus body 72. Hereafter, each cartridge will be referred to as cartridge 430. Figure 2 illustrates the state in which each cartridge 430 is aligned and overlapping in the second direction Y. In Figure 2, it is typically labeled as cartridge 430. Since each cartridge 430 is aligned in the second direction Y, the direction in which each cartridge 430 is aligned intersects (is perpendicular to) the direction in which each developing unit 9 is aligned.

[0031] Cartridges 430Y, 430M, 430C, and 430K are designated as the first cartridge (first toner container), second cartridge (second toner container), third cartridge (third toner container), and fourth cartridge (fourth toner container), respectively.

[0032] Figure 3(a) is a perspective view of the image forming apparatus 1 with the front door 72b closed. Figure 3(b) is a perspective view of the image forming apparatus 1 with the front door 72b open. Figure 3(c) is a perspective view of the image forming apparatus 1 with the front door 72b open and the cartridge 430M removed from the cartridge holder 429.

[0033] Each cartridge 430 is mounted on the upper front side of the device body 72 so that it can be accessed by opening the front door 72b. The position where each cartridge 430 is mounted is also the downstream end of the device body 72 in the discharge direction of the recording medium S discharged by the discharge roller 22.

[0034] The front door 72b is configured to move between a closed position (see Figure 3(a)) that closes the opening 72a (see Figure 3(b)) of the front-facing device body 72 and an open position (see Figure 24(b)) that opens the opening 72a. When the front door 72b is moved to the open position, each cartridge 430 is exposed to the outside of the image forming apparatus 1 through the opening 72a, as shown in Figure 3(b).

[0035] Since each cartridge 430 is arranged in a second direction Y, it is configured to be detachable from the main body 72 of the device in a first direction X, as shown in Figure 3(c). This allows the cartridges 430 that supply toner to each process unit P to be attached to and detached from each process unit P without having to detach each process unit P from the main body 72 of the device.

[0036] By positioning each cartridge 430 on the front side of the image forming apparatus 1, the user can access each cartridge 430 from the front side, as well as access it for retrieving the recording medium S discharged into the discharge tray 23.

[0037] Furthermore, a cartridge holder 429 is located on the front side of the image forming apparatus 1, and the cartridge holder 429 is positioned further forward than the process unit P. Therefore, the process unit P is not exposed even after each cartridge 430 is removed (see Figures 2 and 3(c)).

[0038] Each cartridge 430 is housed inside the main body 72 of the device when the front door 72b is closed.

[0039] As shown in Figure 3(a), indicators 208Y, 208M, 208C, and 208K (hereinafter referred to as each indicator 208) (indicator section, display section) of each color are provided on the front of the image forming apparatus 1. Each indicator 208 is arranged in the second direction Y to correspond to each cartridge 430. Indicator 208Y (first indicator) is yellow, indicator 208M (second indicator) is magenta, indicator 208C (third indicator) is cyan, and indicator 208K (fourth indicator) is black. Each indicator 208 consists of an LED or sticker of a color corresponding to the toner color of each cartridge, and is provided to prevent incorrect installation of each cartridge 430. In addition, each indicator 208 may also have a toner level display function for the corresponding process unit P (each developing unit 9).

[0040] The toner transport mechanism from each cartridge 430 to the corresponding process unit P will be explained using Figures 4 to 8. The unit including each cartridge 430, each process unit P, and a transport path for transporting toner from each cartridge 430 to each process unit P, which will be described later, is defined as the image forming unit 500.

[0041] Figure 4(a) is a perspective view of the image forming unit 500 with each cartridge 430 installed. Figure 4(b) is a perspective view of the image forming unit with each cartridge 430 removed. Figure 5 is a perspective view showing the optical path of the laser beam from the laser scanner unit LB relative to the image forming unit 500. Figure 6(a) is a top view of the laser scanner unit LB and the image forming unit 500. Figure 6(b) is a top view of the image forming unit 500. Figures 7(a) and 7(b) are cross-sections AA and BB of Figure 6(b), respectively. Figure 8(a) is cross-section CC of Figure 6(a).

[0042] In the image forming unit 500 shown in Figures 4 to 8, FE indicates the front side and BE indicates the rear side. RE is the drive side, which mainly receives power from the main unit, and LE, the opposite side, is the non-drive side.

[0043] As shown in Figures 4(a) and 5, below the cartridge holder 429 that holds each cartridge 430, pump units 80Y, 80M, 80C, and 80K (hereinafter referred to as each pump unit 80) corresponding to each color are provided. Each pump unit 80 is aligned in the second direction Y. Pump units 80Y, 80M, 80C, and 80K are designated as the first pump unit, second pump unit, third pump unit, and fourth pump unit, respectively. Each pump unit 80 uses a positive displacement pump such as a reciprocating pump or a rotary pump. A reciprocating pump is a pump that performs suction and discharge by the reciprocating motion of a piston or plunger, and includes piston pumps, plunger pumps, and diaphragm pumps. A rotary pump is a pump that performs suction and discharge by the rotational motion of gears or a rotor, and includes gear pumps, screw pumps, and vane pumps. Note that the four pump units may be configured as a single pump unit. In this embodiment, each pump unit 80 is provided on the main body 72 of the device, but it may also be provided on each cartridge 430.

[0044] As shown in Figures 4(b) and 7(a), the cartridge holder 429 facing the lower surface of each cartridge 430 is provided with exposed openings. These openings are discharge ports 80Ya, 80Ma, 80Ca, and 80Ka (hereinafter referred to as each discharge port 80a) through which compressed air (hereinafter referred to as air) generated by each pump unit 80 is discharged. Each discharge port 80a opens upward.

[0045] The air discharged upward from each outlet 80a is supplied to the inside of each cartridge 430 mounted in the cartridge holder 429. The air supplied to the inside of each cartridge 430 is then discharged to the outside along with the toner. The internal structure of each cartridge 430 will be described later, so it will not be explained in detail here.

[0046] The toner discharged from each cartridge 430 along with air is received at one end of each replenishment pipe 444 via inlets 429Ya, 429Ma, 429Ca, and 429Ka (hereinafter referred to as each inlet 429a) provided in the cartridge holder 429 shown in Figure 4(b). Each replenishment pipe 444 is a toner supply pipe 444Y, 444M, 444C, and 444K. Each replenishment pipe 444 extends to each developing unit 9, and its other end is connected to them. Each inlet 429a is a through-hole provided so as to penetrate the surface of the cartridge holder 429 facing the back of each cartridge 430. Each inlet 429a opens toward a first direction X, which is the direction in which each developing unit 9 is aligned. The direction in which each inlet 429a opens intersects with the direction in which each discharge port 80a opens.

[0047] As shown in Figure 6(b), each supply pipe 444 is connected to the position corresponding to the portion of the cartridge holder 429 where each receiving port 429a (not shown) is provided. The upstream ends 444Yu, 444Mu, 444Cu, and 444Ku (hereinafter referred to as each upstream end 444u) of each supply pipe 444 are connected to the cartridge holder 429 so as to communicate with each receiving port 429a.

[0048] The toner received from each inlet 429a is transported by air discharged from each cartridge 430 through the inside of each supply pipe 444 from each upstream end 444u to each downstream end 444Yd, 444Md, 444Cd, 444Kd (hereinafter referred to as each downstream end 444d), and is supplied to each developing unit 9.

[0049] Each downstream end 444d of each replenishment pipe 444 is connected to the end of each developing unit 9 in the second direction Y. Specifically, the downstream end 444Yd of replenishment pipe 444Y and the downstream end 444Md of replenishment pipe 444M are connected to the LE side end of developing unit Y and the LE side end of developing unit M, respectively. The downstream end 444Cd of replenishment pipe 444C and the downstream end 444Kd of replenishment pipe 444K are connected to the RE side end of developing unit C and the RE side end of developing unit K, respectively. This is because shortening the length of each replenishment pipe 444 reduces pressure loss. This allows for the selection of smaller pump units 80, and thus enables miniaturization of the image forming unit 500.

[0050] Next, the arrangement of cartridge 430Y will be described. As shown in Figure 7(b), cartridge 430Y and each process unit P (each developing unit 9) are arranged on a virtual line VL1 extending in the first direction X. In other words, cartridge 430Y is arranged to be aligned with each developing unit 9 in the first direction X. To put it another way, when viewed in the first direction X, at least a portion of cartridge 430Y is arranged to overlap with each developing unit 9. Cartridges 430M, 430C, and 430K are also arranged to be aligned with each developing unit 9 in the first direction X. To put it another way, when viewed in the first direction X, at least a portion of each of cartridges 430M, 430C, and 430K is arranged to overlap with each developing unit 9. This arrangement of each cartridge 430 makes it possible to reduce the height of the image forming apparatus 1 in the third direction Z, thereby enabling miniaturization of the image forming apparatus 1. Furthermore, each cartridge 430 may be located above each process unit (each developing unit 9) in the third direction Z.

[0051] Next, the arrangement of each supply pipe 444 will be explained. In Figures 5, 6(b), and 8, the optical paths of the laser beam from the laser scanner unit LB are visualized for convenience. Optical paths LY, LM, LC, and LK (hereinafter referred to as each optical path L) are the optical paths of the laser beam emitted from the laser scanner unit LB to the photosensitive drums 4Y, 4M, 4C, and 4K, respectively.

[0052] Each replenishment pipe 444 is positioned so as not to interfere with each optical path L. Specifically, as shown in Figures 6(b) and 8(a), replenishment pipes 444Y and 444M are provided at the LE-side end of each process unit P, avoiding each optical path L in the second direction Y. Replenishment pipe 444Y is positioned outside, i.e., on the LE side, of replenishment pipe 444M in the first direction X.

[0053] At least a portion of the supply pipe 444Y does not overlap with the laser scanner unit LB when viewed from above in the third direction Z, as shown in Figure 6(a). The supply pipe 444M overlaps with the laser scanner unit LB when viewed from above in the third direction Z, as shown in Figure 6(a).

[0054] As shown in Figure 8(a), the replenishment pipes 444Y and 444M are located below the laser scanner LB and above each process unit P (each developing unit 9, each developing container 3) in the third direction Z. In other words, the replenishment pipes 444Y and 444M are located between the position of the laser scanner LB and the position of each process unit P in the third direction Z. Furthermore, the width of each optical path L increases in the second direction Y as it approaches the process unit P (each photosensitive drum 4) from the laser scanner unit LB. Therefore, in the third direction Z, there is a space between the optical path LK and the laser scanner unit LB, before the width of the optical path LK increases in the second direction Y. The replenishment pipe 444M is located in that space between the optical path LK and the laser scanner unit LB in the third direction Z. In other words, the laser scanner unit LB, the supply pipe 444M, and the optical path LK are located on a virtual line VL2 that extends in the third direction Z when viewed in the first direction X, as shown in Figure 8(a).

[0055] Next, as shown in Figures 6(b), 8(a), and 8(b), the replenishment pipes 444C and 444K are located at the RE-side end of each process unit P, avoiding each optical path L in the second direction Y. In other words, in the second direction Y, the replenishment pipes 444C and 444K are located at the end opposite to the end where the replenishment pipes 444Y and 444M are located. Furthermore, in the second direction Y, the replenishment pipe 444C is located outside, i.e., on the RE side, of the replenishment pipe 444K.

[0056] As shown in Figure 6(a), supply pipes 444C and 444K overlap with the laser scanner unit LB when viewed from above in the third direction Z. Note that in Figure 6(a), supply pipes 444C and 444K are hidden from view by the laser scanner unit LB.

[0057] As shown in Figure 8(b), the replenishment pipes 444C and 444K are located below the laser scanner LB and above each process unit P (each developing unit 9, each developing container 3). In other words, in the third direction Z, the replenishment pipes 444C and 444K are located between the position of the laser scanner LB and the position of each process unit P. In the third direction Z, the replenishment pipe 444K is located in the space between the optical path LK and the laser scanner unit LB.

[0058] Furthermore, as shown in Figure 8(a), the laser scanner unit LB, the supply pipe 444K, and the optical path LK are located on a virtual line VL3 that extends in the third direction Z when viewed in the first direction X.

[0059] As shown in Figure 8(b), the supply pipe 444C is located above the supply pipe 444K. Furthermore, the supply pipe 444C overlaps the supply pipe 444K by ΔY in direction Y, and the supply pipe 444C overlaps the supply pipe 444K by ΔZ in direction Z.

[0060] As explained above, by arranging each supply pipe 444, it becomes possible to miniaturize the image forming unit 500 in the second direction Y or the third direction Z. However, the supply pipes do not necessarily have to be arranged as described above.

[0061] The image forming unit 500 is preferably configured in a way that allows easy access to the process unit P and the supply pipe 444 for maintenance and replacement of these components in the event of a malfunction. Therefore, in this embodiment, the image forming unit 500 is configured to be able to be pulled out from the BE side (rear side) to the FE side (front side) relative to the main body 72 (intermediate transfer belt unit 11). However, the image forming apparatus 1 may be configured in a way that prevents the image forming unit 500 from being pulled out.

[0062] (Cartridge structure) The structure of each cartridge 430 (toner container) in this embodiment will be explained using Figures 4(a), 10 to 12.

[0063] As shown in Figure 4(a), the width La in the second direction Y of cartridge 430K is wider than the width Lb of cartridges 430Y, M, and 430C (hereinafter referred to as cartridges 430Y-C). Therefore, the volume for accommodating toner in cartridge 430K is larger than the volume of cartridges 430Y-C. By allowing more black toner, which is generally consumed more than other colors, the replacement frequency of cartridges 430Y, 430M, 430C, and 430K is more easily equalized. Except for the width in the second direction Y, the structure of each cartridge 430 is the same, so here we will explain the structure of cartridge 430Y, and omit the explanation of the structures of cartridges 430M, 430C, and 430K.

[0064] Figures 10(a), (b), (c), (d), and (e) are the front, top, bottom, right side, and rear views of cartridge 430Y, respectively. Figure 11(a) is a cross-sectional view of HH in Figure 10(e). Figure 11(b) is a perspective view of cartridge 430Y. Figure 11(c) is an exploded perspective view of cartridge 430Y. Figure 12(a) is a cross-sectional view of GG in Figure 10(b). Figure 12(b) is a perspective view of Figure 12(a). The following description of the structure of cartridge 430Y is basically based on the state (position) in which cartridge 430Y is attached to cartridge holder 429.

[0065] As shown in Figure 11, the cartridge 430Y comprises a first frame 430Ya, a second frame 430Yb, a filter 83Y (first filter, first ventilation member), and a discharge pipe 85Y (first discharge pipe, first passage).

[0066] Although not shown in the diagram, the cartridge 430M similarly includes a third frame 430Ma, a fourth frame 430Mb, a filter 83M (second filter, second ventilation member), and a discharge pipe 85M (second discharge pipe, second passage).

[0067] Similarly, cartridge 430C also includes a fifth frame 430Ca, a sixth frame 430Cb, a filter 83C (third filter, third ventilation member), and a discharge pipe 85C (third discharge pipe, third passage).

[0068] Similarly, cartridge 430K also includes a seventh frame 430Ka, an eighth frame 430Kb, a filter 83K (fourth filter, fourth ventilation member), and a discharge pipe 85K (fourth discharge pipe, fourth passage).

[0069] Although the first frame 430Ya and the second frame 430Yb in this embodiment are made of resin, they may also be made of paper or the like. As shown in Figure 10(e), the back surface 4300Ya of the first frame 430Ya is provided with an outlet 430Ya1 (first outlet). As shown in Figure 10(c), the bottom surface 4300Yb of the second frame 430Yb is provided with an inlet 430Yb1 (first inlet, first intake).

[0070] It is preferable to provide an outlet 430Ya1 and an inlet 430Yb1 on the surface of cartridge 430Y, excluding the surface that intersects the second direction Y, which is the direction in which each cartridge 430 is aligned (the surface whose normal direction is oriented towards the second direction Y). By configuring in this way, the gap G (Gym, Gmc, Gck) between each cartridge 430 shown in Figure 4(a) can be reduced.

[0071] As a result, the gaps in the transport path that would be necessary if the discharge port 430a1 and receiving port 430b1 were provided become unnecessary, allowing the width L of each cartridge 430 to be increased. Therefore, the volume for housing the toner in each cartridge 430 can be increased. Gap Gym is the gap in the second direction Y between cartridge 430Y and cartridge 430M. Gap Gmc is the gap in the second direction Y between cartridge 430M and cartridge 430C. Gap Gck is the gap in the second direction Y between cartridge 430C and cartridge 430K.

[0072] Furthermore, as shown in Figure 10(e), the discharge port 430Ya1 is provided on the back surface 4300Ya of the cartridge 430Y (the downstream end surface in the mounting direction of the cartridge 430Y) so as to open toward the downstream side in the mounting direction. Therefore, when mounting the cartridge 430Y into the cartridge holder 429, it becomes easier to engage the discharge port 430Ya1, which is facing the mounting direction, with the receiving port 429Ya of the cartridge holder 429 so as to communicate with it. Note that the discharge port 430Ya1 may also be provided on the bottom surface 4300Yb or top surface of the cartridge 430Y, and the receiving port 430Yb1 may be provided on the back surface 4300Ya or top surface. If there is sufficient space in the device body 72, the discharge port 430Ya1 and the receiving port 430Yb1 may also be provided on surfaces intersecting the second direction Y.

[0073] The same applies to colors other than yellow, although they are not shown in the illustration. Cartridge 430M has an outlet 430Ma1 (second outlet) and an inlet 430Mb1 (second inlet, second intake) arranged in the same way as cartridge 430Y. Cartridge 430C has an outlet 430Ca1 (third outlet) and an inlet 430Cb1 (third inlet, third intake) arranged in the same way as cartridge 430Y. Cartridge 430K has an outlet 430Ka1 (fourth outlet) and an inlet 430Kb1 (fourth inlet, fourth intake) arranged in the same way as cartridge 430Y.

[0074] An unillustrated sealing member (seal or shutter) may be provided at the discharge port 430Ya1. When the cartridge 430Y is not mounted in the cartridge holder 429 of the device body 72, the sealing member seals the discharge port 430Ya1, preventing the toner T contained inside from leaking out of the cartridge 430Y. When the cartridge 430Y is mounted in the cartridge holder 429, the sealing member is removed or moved, leaving the discharge port 430Ya1 open.

[0075] The label 430Ys on the front of the cartridge 430Y, shown in Figure 10(a), is for indicating the color of the toner inside. The label 430Ys also displays information about the cartridge 430Y, such as instructions illustrating how to install the cartridge 430Y into the cartridge holder 429.

[0076] As shown in Figure 11(c), the first frame 430Ya and the second frame 430Yb each have flange portions 430Ya2 and 430Yb2, respectively. The internal space SPY of the cartridge 430Y shown in Figure 11(a) is formed by welding the flange portions 430Ya2 and 430Yb2 to each other by ultrasonic welding. The flange portions 430Ya2 and 430Yb2 shown in Figure 11(c) may also be fixed to each other with adhesive or screws.

[0077] As shown in Figure 11(a), the filter 83Y is installed to divide the internal space SPY of the cartridge 430Y into two parts: the toner chamber 430Yc (first chamber) and the air chamber 430Yd (second chamber). In other words, the air chamber 430Yd is adjacent to the toner chamber 430Yc via the filter 83Y.

[0078] The same applies to colors other than yellow, although they are not shown in the diagram. Filter 83M is designed to divide the internal space SPM of cartridge 430M into two parts: the toner chamber 430Mc (third chamber) and the air chamber 430Md (fourth chamber). In other words, the air chamber 430Md is adjacent to the toner chamber 430Mc via filter 83M. Filter 83C is designed to divide the internal space SPC of cartridge 430C into two parts: the toner chamber 430Cc (fifth chamber) and the air chamber 430Cd (sixth chamber). In other words, the air chamber 430Cd is adjacent to the toner chamber 430Cc via filter 83C. Filter 83K is designed to divide the internal space SPK of cartridge 430K into two parts: the toner chamber 430Kc (seventh chamber) and the air chamber 430Kd (eighth chamber). In other words, the air chamber at 430Kd is adjacent to the toner chamber at 430Kc, separated by a filter at 83K.

[0079] As shown in Figure 11(a), the toner chamber 430Yc is located above the air chamber 430Yd and is aligned with the air chamber 430Yd in a third direction Z. In other words, the orientation in which the cartridge 430Y is oriented so that the toner chamber 430Yc is above the air chamber 430Yd is the mounting orientation for the device body 72. Therefore, in this embodiment, the receiving port 430Yb1 opens in this alignment direction, and the discharge port 430Ya1 opens in a direction intersecting this alignment direction.

[0080] The toner chamber 430Yc is configured to house the toner T. In the toner chamber 430Yc, the toner T is supported by the filter 83Y.

[0081] The air chamber 430Yd does not contain toner. The filter 83Y is made of a porous material, for example, resin fibers, with a pore size and density that allows air to pass through while inhibiting toner passage. As shown in Figures 11 and 12, the filter 83Y is held between the first frame 430Ya and the second frame 430Yb, with its outer edge 83Ya sandwiched between the flange portion 430Ya2 of the first frame 430Ya and the flange portion 430Yb2 of the second frame Yb. The filter 83Y is inclined from the outer edge 83Ya towards the lowest point 83Yb, which is below the outer edge 83Ya. In other words, the filter 83Y has a portion (inclined portion) that slopes downward as it moves towards the lowest point 83Yb in the first direction X, the second direction Y, or the horizontal direction.

[0082] The lowest part 83Yb is the portion that protrudes from the outer edge 83Ya in the direction from the toner chamber 430Yc toward the air chamber 430Yd. As shown in Figures 11(a) and 12(b), the lowest part 83Yb is located in the center of the filter 83Y in the first direction X and the second direction Y.

[0083] A discharge pipe 85Y (passage) is provided in the toner chamber 430Yc. In this embodiment, the discharge pipe 85Y is a resin-molded component, but it may also be made of paper or rubber. The discharge pipe 85Y has an inlet 85Ya (first opening) and an outlet 85Yb (second opening), and is a pipe that extends from the inlet 85Ya to the outlet 85Yb. The discharge pipe 85Y is a passage through which the toner T contained in the toner chamber 430Yc is moved toward the discharge port 430Ya1. The discharge pipe 85Y has a first portion 85Y1 which has an inlet 85Ya and extends in a third direction Z, and a second portion 85Y2 which has an outlet 85Yb and extends in a first direction X. The direction in which the first portion 85Y1 extends and the direction in which the second portion 85Y2 extends intersect (orthogonal). The outlet 85Yb of the discharge pipe 85Y is connected to the discharge port 430Ya1. The inlet 85Ya of the discharge pipe 85Y is positioned opposite the lowest part 83Yb, which is part of the filter 83Y, with a gap between them. It is preferable that the inlet 85Ya be close to the filter 83Y. When the amount of toner T in the toner chamber 430Yc becomes low, the toner T, which has been fluidized by the air received from the receiving inlet 430Yb1, moves along the slope of the filter 83Y described above and collects at the lowest part 83Yb. The inlet 85Ya of the discharge pipe 85Y guides the toner T collected at the lowest part 83Yb of the filter 83Y to the discharge port 430Ya1. With this configuration, even when the amount of toner contained in the toner chamber 430Yc of the cartridge 430Y becomes low, the toner T can be efficiently discharged to the outside of the cartridge 430Y.

[0084] The cartridge in this embodiment has a structure that uses air to expel toner from the outside of the cartridge, and does not require any rotating members such as screws. Therefore, it is possible to create a cartridge with a simple structure and a small number of parts.

[0085] (Toner transport mechanism) This section describes the mechanism by which toner stored in the toner chamber 430Yc of cartridge 430Y is transported to the developing unit PY.

[0086] As shown in Figure 7(a), air is discharged upward from the outlet 80Ya of the pump unit 80Y. As shown in Figure 11(a), the air is received into the air chamber 430Yd via the inlet 430Yb1 of the cartridge 430Y. The air then increases the air pressure in the air chamber 430Yd, passes through the filter 83Y, and flows into the toner chamber 430Yc. The air that flows into the toner chamber 430Yc penetrates between the toner particles T, causing the toner T to become fluid. The toner T, now fluidized with the air, is moved by the air through the inlet 430Yb1 from the inlet 85Ya to the outlet 85Yb in the discharge pipe 85Y. The toner T is then discharged to the outside of the cartridge 430Y from the outlet 430Ya1.

[0087] As in this embodiment, by providing an air chamber 430Yd, which is a highly sealed space as shown in Figure 11(a), between the discharge port 80Ya shown in Figure 7(a) and the filter 83Y, the air discharged from the discharge port 80Ya is efficiently directed to the filter 83Y without being dispersed outside the cartridge 430Y. For example, in situations where the toner T in the toner chamber 430Yc is likely to aggregate, such as when the cartridge 430Y is subjected to vibration or left unattended for a long time, the pressure required to allow air to flow into the toner chamber 430Yc through the filter 83Y increases. Even in such cases, air is continuously supplied from the pump unit 80Y shown in Figure 7(a) to the air chamber 430Yd shown in Figure 11(a), increasing the pressure (atmospheric pressure) inside the air chamber 430Yd. In this way, it becomes possible to supply air to the toner chamber 430Yc through the filter 83Y.

[0088] Furthermore, by providing an air chamber 430Yd, the pump unit 80Y can continue to supply air to the air chamber 430Yd without dispersing it until the pressure is sufficient for air to pass from the filter 83Y into the toner chamber 430Yc. The pump unit 80Y only needs to be able to generate this pressure; there are no special requirements for discharge speed or discharge volume. For this reason, it is possible to use a small pump unit, which in turn contributes to the miniaturization of the device.

[0089] As shown in Figure 4(b), the toner T discharged from the outlet 430Ya1 of cartridge 430Y enters the replenishment pipe 444Y through the receiving port 429Ya of cartridge holder 429 and into the replenishment pipe 444Y from the upstream end 444Yu shown in Figure 7(a). The toner T that has entered the replenishment pipe 444Y from the upstream end 444Yu is moved to the downstream end 444Yd by the air that flows in with the toner T and is replenished to the developing unit 9Y (developing container 3Y) of process unit PY.

[0090] As shown in Figure 6(b), toner is supplied into the developing unit 9Y (developing container 3Y) from the end of the developing unit 9Y in the second direction Y. The toner is stirred and leveled in the developing container 3Y by the stirring members SY1 and SY2 shown in Figure 7(b). The stirring members SY1 and SY2 may be screws configured to transport toner in the second direction Y from the end of the developing unit 9Y on the side to which the downstream end 444Yd of the supply pipe 444Y is connected to the end of the developing unit 9Y on the opposite side.

[0091] The space within the developing unit 9Y (developing container 3Y) where yellow toner is supplied may be called the first space. The space within the developing unit 9C (developing container 3C) where cyan toner is supplied may be called the second space. The space within the developing unit 9M (developing container 3M) where magenta toner is supplied may be called the third space. The space within the developing unit 9K (developing container 3K) where black toner is supplied may be called the fourth space.

[0092] Since air as well as toner T flows into the developing unit 9Y (developing container 3Y) from the supply pipe 444Y, the internal pressure inside the developing unit 9Y tends to rise. Therefore, in this embodiment, as shown in Figures 4 and 6(b), an exhaust filter PYf is provided on the upper surface of the developing unit 9Y. The exhaust filter section PYf is a part of the frame forming the developing unit 9Y in which through holes are provided, and a filter such as nonwoven fabric is provided in the through holes. The filter is configured to allow air to pass through but to prevent the passage of toner. The toner T that flows into the inside of the developing unit 9Y from the supply pipe 444Y remains in the developing unit 9Y. At least a portion of the air is discharged to the outside of the developing unit 9Y from the exhaust filter section PYf. This suppresses the rise in internal pressure inside the developing unit 9Y, making it easier for toner T and air to flow into the developing unit 9Y from the cartridge 430Y via the supply pipe 444Y.

[0093] In this embodiment, the exhaust filter PYf is located in the center of the developing unit 9Y in the second direction Y. Alternatively, the exhaust filter PYf may be located in the position indicated as exhaust filter PYfa. In this case, exhaust filter PYfa is located at the end of the developing container 3Y on the side where the upstream end 444Yu of the supply pipe 444Y is located in the second direction Y. Alternatively, as indicated as exhaust filter PYfb, exhaust filter PYf may be located at the end of the developing unit 9Y opposite to the end where the upstream end 444Yu of the supply pipe 444Y is located in the second direction Y. Furthermore, the exhaust filter may be located on the side of the developing unit 9Y instead of the top surface.

[0094] In configurations where the direction of the transport path changes midway, such as in the supply pipes 444 of this embodiment, or where the transport path differs for each color, it is preferable to use air as the transport means for transporting the toner. This improves the design flexibility of the transport path compared to using screws or the like as the transport means, and reduces the number of parts because transport components are not required.

[0095] This configuration describes a conveying method using air, but conveying methods such as screws may also be used. Furthermore, a combination of air and screw conveying methods may be used.

[0096] Characteristic features of Embodiment 1 of the present invention will be explained using Figures 1 and 13 to 21.

[0097] Figure 1(a) shows a top view of the developing unit 9Y1, and Figure 1(b) shows a front view of the developing unit 9Y1. Figure 1(b) shows an assembly diagram along with the parts assembled to the developing unit 9Y1. Figure 30 shows a side view of the developing unit 9Y1. Figure 30(a) is a view from the LE side, and Figure 30(b) is a view from the RE side. Figure 31 shows a schematic side view of the developing unit 9Y. Both Figure 31(a) and Figure 31(b) are views from the LE side. Here, Figure 31(b) is a side view in black, and Figure 31(a) is a side view in a color other than black.

[0098] Figure 13(a) shows an assembled perspective view of the developing unit 9Y1, and Figure 13(b) shows a perspective view of the developing unit 9Y1 after assembly. Figure 14 is a perspective view of the process cartridge PY1. Figure 15 shows a perspective view of the relay member 751. Figure 16(a) shows an assembled perspective view of the developing unit 9Y2, and Figure 13(b) shows a perspective view of the developing unit 9Y2 after assembly. Figure 17 shows a perspective view of the sealing cap 771. Figure 18(a) shows an assembled perspective view of the developing unit 9C3, and Figure 18(b) shows a perspective view of the developing unit 9C3 after assembly. Figure 19(a) shows an assembled perspective view of the developing unit 9Y4, and Figure 19(b) shows a perspective view of the developing unit 9Y4 after assembly. Figure 20 is a perspective view of the image forming unit 500. The laser beam paths (LY, LM, LC, LK) are also visualized and shown. Figure 21 is a top view of the image forming unit 500. In this figure, the laser beam paths (LY, LM, LC, LK) are also visualized and shown.

[0099] (Hole on the lid) The developing unit 9Y1 shown in Figure 1 is an improved version of the developing unit 9Y described above. As shown in Figure 1(b), the developing unit 9Y1 has a toner storage container 710 from which toner is supplied from a toner cartridge, which is a toner supply container, via a supply pipe 444Y, which is a toner supply tube. The toner storage container 710 consists of a toner container 710b that rotatably supports the developing roller 6Y, and a lid 710a that closes the opening of the toner container 710b. The lid 710a is welded and joined to the opening of the toner container 710b.

[0100] The cover 710a has two through holes, a first hole 711a and a second hole 711b, at different positions on a virtual axis VA2 parallel to the rotation axis direction of the rotation axis VA1 of the developing roller 6Y. The shapes of these holes are identical. Furthermore, the first hole 711a and the second hole 711b are arranged symmetrically with respect to the longitudinal center VF of the toner carrying area DA of the developing roller 8Y.

[0101] In Figure 1, the first hole 711a is located on the non-driven side LE, and the second hole 711b is located on the driven side RE.

[0102] As described above, Figure 30 shows a side view of the developing unit 9Y1, and is also a view along the rotation axis VA1 of the developing roller 6Y. When viewed along the rotation axis VA1 of the developing roller 6Y in this way, the first hole 711a and the second hole 711b are in overlapping positions. In Figure 30(a), the ellipse showing the position of the first hole 711a and the ellipse showing the position of the second hole 711b do not coincide, but the two hole positions may be configured to coincide.

[0103] The toner container 710 is divided into a toner container 710b and a lid 710a along the position of the dashed line in Figure 30(a), with the lid 710a on the side indicated by arrow A and the toner container 710b on the side indicated by arrow B.

[0104] Furthermore, the lid 710a is common to both yellow, cyan, magenta, and black toners, but the volume of the black toner container may be increased. Figure 31(a) shows the configuration for yellow, cyan, and magenta, and Figure 31(b) shows the configuration for black. Thus, the volume of the black toner container 710b2 is larger than that of the toner containers 710b of the other colors. However, the lid 710a is common to all colors. In this way, even if the capacity of the toner container is changed according to the toner color to meet the needs, the same effect as in this embodiment can be obtained by keeping the lid 710a common.

[0105] (Intermediate component) The following describes the intermediate member 751 (first intermediate member) that connects the replenishment pipe 444 and the toner storage container 710, as shown in Figure 1(b). As shown in Figure 15, the intermediate member 751 is made of an elastic material. It has a container mounting portion 751b with a cylindrical groove 751a, which is fitted into the first hole 711a (Figure 13(a)) and assembled. It also has a cylindrical pipe mounting portion 751c for attaching the replenishment pipe 444Y. Inside the intermediate member 751, there is a through hole 751d that serves as a toner transport passage.

[0106] As shown in Figure 13(a), the intermediate member 751 is assembled into the first hole 711a. The outer diameter of the cylindrical groove 751a of the intermediate member 751 in Figure 15 is set to be larger than the inner diameter of the first hole 711a in Figure 13(a). The container mounting portion 751b is assembled into the first hole 711a while undergoing elastic deformation. As a result, the intermediate member 751 fills the gaps in the contact areas of each component, preventing toner leakage from the toner container 710 to the outside.

[0107] Another assembly method involves adhesive bonding to seal the toner at the contact points of each component. In contrast, using the aforementioned elastic intermediate member 751 eliminates the need for adhesive bonding. Another possible method involves using a sealing member (not shown) to fill the gap between the intermediate member 751 and the toner container 710.

[0108] The outer diameter of the pipe mounting portion 751c is set to be larger than the inner diameter of the replenishment pipe 444Y. Since the pipe mounting portion 751c is configured to be elastically deformable, it is assembled while contracting to correspond to the inner diameter of the replenishment pipe 444Y. As a result, it fills the gaps in the assembly portions (outer diameter and inner diameter) of each component and prevents toner leakage to the outside from the part to which the replenishment pipe 444Y is attached. Even if the intermediate member 751 is an inelastic material, the same effect can be obtained if the replenishment pipe 444Y is an elastic material.

[0109] As shown in Figure 15, the intermediate member 751 is formed such that the central axis VJ2 of the pipe mounting portion 751c intersects the central axis VJ1 of the container mounting portion 751b at a predetermined angle, rather than coaxially. After attaching the container mounting portion 751b to the first hole 711a of the developing unit 9Y1, the protrusion angle of the pipe mounting portion 751c from the container can be changed by rotating it around the central axis VJ1. In this way, the protrusion angle can be adjusted with a single intermediate member 751, which allows for flexibility in the arrangement of the replenishment pipe 444.

[0110] (Exhaust filter) As shown in Figure 13(a), an exhaust filter 761 is attached to the second hole 711b by means of welding or adhesive. As described above, the toner T that flows into the developing unit 9Y1 from the supply pipe 444Y remains in the developing unit 9Y1, and at least a portion of the air is discharged to the outside of the developing unit 9Y1 through the exhaust filter 761. This suppresses the rise in internal pressure inside the developing unit 9Y1, making it easier for toner T and air to flow into the developing unit 9Y1 from the cartridge 430Y via the supply pipe 444Y.

[0111] Figure 13(b) shows the development unit 9Y1 with the intermediate member 751, supply pipe 444Y, and exhaust filter 761 assembled. Subsequently, the development unit 9Y1 is assembled to the drum unit 8Y, and the process cartridge PY1 is completed (Figure 14).

[0112] (Sealing cap) As shown in Figure 16, if the exhaust filters PfY, PfYa, and PfYb are placed on the upper surface of the lid 710a, sufficient exhaust can be achieved, and it may not be necessary to further place the exhaust filter 761 in the second hole 711b. In that case, it is also possible to assemble a sealing cap 771 that seals the toner inside the toner container 710 into the second hole 711b. The sealing cap 771 is an elastic material and is formed in the shape shown in Figure 17. It has a container mounting portion 771b with a cylindrical groove 771a and is fitted into the second hole 711b (Figure 16(a)). The outer diameter of the cylindrical groove 771a of the sealing cap 771 is set to be larger than the inner diameter of the second hole 711b. As a result, the container mounting portion 771b is assembled into the second hole 711b while elastically deforming and contracting. As a result, the gaps in the contact parts of each component are filled, preventing toner leakage from the toner container 710 to the outside.

[0113] (Reverse arrangement of relay members) As shown in Figures 20 and 21, the supply pipes 444 for each color are sometimes distributed between the non-drive side LE and the drive side RE to make effective use of the space inside the main unit (in this figure, two supply pipes 444 are distributed between the non-drive side LE and the drive side RE). In other words, in this case, a developing unit configuration is required in which the arrangement of the developing unit 9Y1 and the supply pipes 444 is reversed in the longitudinal direction of the developing roller 6.

[0114] In this case, as shown in Figure 18(a), the shapes of the first hole 711a and the second hole 711b are identical. Therefore, the relay member 751 can be assembled into the second hole 711b, thereby allowing the supply pipe 444C to be assembled into the relay member 751. Furthermore, the exhaust filter 761 can be assembled into the first hole 711a.

[0115] Identical circular ribs 712a and 712b are formed around the first hole 711a and the second hole 711b of the cover 710a. Ribs 712a and 712b can also be used to position the circular exhaust filter 761.

[0116] Instead of the exhaust filter 761, a sealing cap 771 can also be installed (not shown).

[0117] (Intermediate members are placed at both ends) As shown in Figure 19, it is also possible to place the replenishment pipe 444Ya on the non-drive side LE and the replenishment pipe 444Yb on the drive side RE. This makes it possible to increase the replenishment speed. In addition, replenishment from both ends makes it easier to mix the toner in the toner storage container 710.

[0118] Up to this point, we have described the developer units 9Y1, 9Y2, and 9Y4 that house yellow (Y) toner, and the developer unit 9C3 that houses cyan (C) toner. These developer unit configurations are similarly applicable to any developer unit that houses yellow (Y), magenta (M), cyan (C), or black (K) toner.

[0119] To summarize, as shown in Figure 1(b), the lid 710a has a first hole 711a and a second hole 711b at different positions on a virtual axis VA2 parallel to the rotation axis VA1 of the developing roller 6Y. The shapes of these holes are identical. This allows the relay member 751, exhaust filter 761, and sealing cap 771 to be selectively placed in the first hole 711a and the second hole 711b without increasing the number of dedicated parts for each color of the lid 710a, as shown in Figures 13 and 16.

[0120] Furthermore, even if the shapes of the first hole 711a and the second hole 711b are different, the mounting portions of the intermediate member 751, exhaust filter 761, and sealing cap 771 to the holes can be configured to accommodate the different shapes of these multiple holes, allowing for selective placement. However, if the holes are the same shape, the shapes of the mounting portions of the intermediate member 751, exhaust filter 761, and sealing cap 771 can be further simplified.

[0121] Furthermore, the first hole 711a and the second hole 711b are arranged symmetrically with respect to the longitudinal center VF of the toner-carrying area DA of the developing roller 8Y. In this way, each supply pipe 444 can be placed short at both ends of the longitudinal axis, avoiding the laser beam paths L located in the longitudinal center. As a result, optimal toner supply to the developing unit 9 can be achieved while miniaturizing the main unit.

[0122] This configuration allows the lid 710a to be a common part with the same shape for each toner color. This reduces the number of parts required during factory assembly, making management easier. Cost reduction due to economies of scale is also expected. If the lid 710a is an injection-molded resin part, the mold can be shared because it has a common shape for each toner color. This means that only one mold is needed for each color, thus reducing mold costs. As it is a common part, the dimensions of the part will match for each color, and with only one mold, there will be no dimensional variations due to the mold. Interfaces such as the intermediate member 751, exhaust filter 761, and sealing cap 771 will also be common, which offers advantages such as easier dimensional management of the interface parts.

[0123] <Second Embodiment> Characteristic features of the second embodiment of the present invention will be explained with reference to Figures 22 to 26.

[0124] Figure 22(a) shows a top view of the developing unit 9Y5, and Figure 22(b) shows a front view of the developing unit 9Y5. Figure 22(b) also serves as an assembly drawing showing the parts to be assembled into the developing unit 9Y5. Figure 23(a) shows an assembled perspective view of the developing unit 9Y5, and Figure 23(b) shows a perspective view of the developing unit 9Y5 after assembly is complete. Figure 24 shows a perspective view of the developing unit 9Y6 after assembly is complete. Figure 25 shows a perspective view of the developing unit 9Y7 after assembly is complete. Figure 26 shows a perspective view of the developing unit 9Y8 after assembly is complete.

[0125] (Hole on the lid) As shown in Figure 22(b), the developing unit 9Y5 has a toner container 720 from which toner is supplied from a toner cartridge, which is a toner supply container, via a supply pipe 444Y, which is a toner supply tube. The toner container 720 consists of a toner container 720b that rotatably supports the developing roller 6Y, and a lid 720a that closes the opening of the toner container 720b (Figure 23). The lid 720a is welded and joined to the opening of the toner container 720b.

[0126] As shown in Figure 22(b), the lid 720a has through holes, a first hole 721a, a second hole 721b, a third hole 721c, and a fourth hole 721d, at different positions on a virtual axis VA2 parallel to the rotation axis VA1 of the developing roller 6Y. The shapes of these holes are identical. Furthermore, the first hole 721a and the second hole 721b, and the third hole 721c and the fourth hole 721d are arranged symmetrically with respect to the longitudinal center VF of the toner carrying area DA of the developing roller 8Y.

[0127] In Figure 22, the first hole 721a and the third hole 721c are located on the non-driven side LE, and the second hole 721b and the fourth hole 721d are located on the driven side RE.

[0128] (Intermediate component) The following describes the intermediate member 752 that connects the replenishment pipe 444 and the toner storage container 720. The intermediate member 752 shown in Figure 23(a) is made of an elastic material. Similar to the intermediate member 751 in Figure 15, it has a container mounting portion 752b with a cylindrical groove 752a. The intermediate member 752 is assembled by fitting into the first hole 721a of the lid 720a. It also has a cylindrical pipe mounting portion 752c for attaching the replenishment pipe 444Y. Inside the intermediate member 752, there is a through hole 752d that serves as a toner transport passage. The configuration of these intermediate members 752 is the same as that of the intermediate member 751 in Figure 15. In addition, the outer diameter of the cylindrical groove 752a of the intermediate member 752 is set to be larger than the inner diameter of the hole 721a. As a result, the container mounting portion 752b is assembled into the first hole 721a while elastically deforming. As a result, the gaps in the contact parts of each component can be filled, preventing toner leakage from the toner storage container 720 to the outside. Other assembly methods are as described above.

[0129] Next, the replenishment pipe 444Y is attached to the pipe attachment portion 752c of the intermediate member 752. The outer diameter of the pipe attachment portion 752c is set to be larger than the inner diameter of the replenishment pipe 444Y. Since the pipe attachment portion 752c is configured to be elastically deformable, it is assembled while shrinking in accordance with the inner diameter of the replenishment pipe 444Y. As a result, the gaps between the parts where each component is assembled (outer diameter and inner diameter) are filled, preventing toner leakage to the outside from those parts. If the intermediate member 752 is made of an inelastic material, a similar effect can be obtained by making the replenishment pipe 444Y an elastic material.

[0130] (Exhaust filter) An exhaust filter 761 is attached to the lid 720a by means of welding or bonding, etc., through the second hole 721b. This makes it easier for toner T and air to flow from the cartridge 430Y into the developing unit 9Y5 via the supply pipe 444Y (similar to the effect of the exhaust filter described above).

[0131] (Sealing cap) As shown in Figure 23(a), sealing caps 772 for sealing toner inside the toner container 720 are assembled into the third hole 721c and the fourth hole 721d.

[0132] The sealing cap 772 is formed of an elastic material. The sealing cap 772 also has a container mounting portion 772b having a cylindrical groove 772a that fits into the third hole 721c and the fourth hole 721d for assembly.

[0133] The outer diameter of the cylindrical groove 772a of the sealing cap 772 is set to be larger than the inner diameters of the third hole 721c and the fourth hole 721d. As a result, the container mounting portion 772b is assembled into the third hole 721c and the fourth hole 721d while undergoing elastic deformation. Consequently, the gaps in the contact areas of each component are filled, preventing toner leakage from the toner container 720 to the outside.

[0134] Figure 23(b) shows the developing unit 9Y5 with the intermediate member 752, supply pipe 444Y, exhaust filter 761, and sealing cap 772 assembled. Subsequently, the developing unit 9Y5 is assembled to the drum unit, completing the process cartridge (not shown).

[0135] In Figure 23(b), the exhaust filter 761 is positioned in the second hole 721b, which is furthest from the first hole 721a, where the relay member 752 and the supply pipe 444Y are located, in the longitudinal direction of the developing roller 6Y. The toner supply port and the air outlet are positioned far apart from each other in the longitudinal direction. As a result, airflow is generated in the longitudinal direction within the toner container 720, making it easier for the toner to circulate throughout the longitudinal direction within the toner container 720.

[0136] (Exhaust filter added) Depending on the degree of ventilation, an additional area of ​​the exhaust filter may be required. In such cases, as shown in Figure 24, it is possible to install an exhaust filter 761 in the fourth hole 721d as well.

[0137] Furthermore, as shown in Figure 25, it is also possible to configure the system so that an exhaust filter 761 is also installed in the third hole 721c.

[0138] (Intermediate members are placed at both ends) As shown in Figure 26, it is also possible to place a replenishment pipe 444Ya on the non-drive side LE of the developing unit 9Y8 and a replenishment pipe 444Yb on the drive side RE. By providing two replenishment pipes, it is possible to increase the toner replenishment speed. In addition, replenishment from both ends of the developing unit 9Y8 makes it easier to mix the toner in the toner storage container 720.

[0139] (Attachment section for relay member) Figure 27(a) is a top view showing the relay member 752 and the portion to which the relay member 752 is attached. Figure 27(b) is a front view thereof.

[0140] A circular rib 722a is formed protruding from the first hole 721a (Figure 27(a)) of the lid 720a. The rib 722a has eight recesses 723a at 45° intervals with the center of the first hole 721a as the axis of rotation.

[0141] As shown in Figure 23, when the relay member 752 is attached to the first hole 721a, the outer shape of the cylindrical pipe mounting portion 752c engages with the recess 723a, as shown in Figure 27(b), thereby restricting the direction in which the through hole 752d of the relay member 752 faces. In this configuration, eight directions can be selected and restricted in 45° increments when viewed from the direction in Figure 27(a). In other words, the orientation of the replenishment pipe 444 connected from the developing unit 9 can be restricted relative to the lid 720a. Once the orientation is determined, it becomes possible to set a shorter distance from the toner cartridge 80Y to the replenishment pipe 444Y. Furthermore, it is possible to arrange each component while considering the deflection of the elastic replenishment pipe 444Y. As a result of the optimal arrangement, good toner transport is maintained.

[0142] Furthermore, the circular rib 722a, when viewed from above, can also be used to position the circular exhaust filter 761 when assembling it onto the cover 720a.

[0143] Intermediate members 752 can be selectively attached to the second hole 721b, third hole 721c, and fourth hole 721d, in addition to the first hole 721a. A circular rib similar in shape to 722a is formed around these holes, and the same effect as described above can be obtained when intermediate members 752 are assembled.

[0144] To summarize, as shown in Figure 22(b), the lid 720a has a first hole 721a, a second hole 721b, a third hole 721c, and a fourth hole 721d at different positions on a virtual axis VA2 parallel to the rotation axis VA1 of the developing roller 6Y. The shapes of these holes are identical.

[0145] This allows for the selective placement of the intermediate member 752, exhaust filter 761, and sealing cap 772 in the first hole 721a, second hole 721b, third hole 721c, and fourth hole 721d without increasing the number of dedicated parts for each color of the lid 720. The hole that allows for the shortest possible supply pipe 444 should be selected for each color. For example, the intermediate member 752 is placed in the first hole 721a for yellow, while it is placed in the third hole 721c for magenta. Similarly, the intermediate member 752 is placed in the fourth hole 721d for cyan, and in the second hole 721b for black thread.

[0146] The exhaust filter 761 is placed in the hole at the end opposite to the side where the intermediate member 752 is located in the longitudinal direction. That is, as shown in Figure 23, in the yellow color, the exhaust filter 761 is placed in the second hole 721b. Similarly, in the magenta color, the exhaust filter 761 is placed in the second hole 721b. In the cyan and black colors, the exhaust filter 761 is placed in the first hole 721a. In addition, sealing caps 772 are placed in the holes where neither the intermediate member 752 nor the exhaust filter 761 is placed.

[0147] Here, let's assume that the shapes of the first hole 721a, the second hole 721b, the third hole 721c, and the fourth hole 721d are different. Even in such a case, the mounting portions of the intermediate member 752, the exhaust filter 761, and the sealing cap 772 are configured to accommodate the different shapes of these multiple holes. This allows for selective placement. However, if the shapes of the holes are the same, the shapes of the mounting portions of the intermediate member 752, the exhaust filter 761, and the sealing cap 772 can be further simplified.

[0148] Furthermore, the first hole 711a and the second hole 711b, and the third hole 721c and the fourth hole 721d are arranged symmetrically with respect to the longitudinal center VF of the toner-carrying area DA of the developing roller 8Y. This makes it easier to arrange two supply pipes 444 at each longitudinal end. It also makes it easier to configure the system to avoid the laser beam paths L located in the longitudinal center. Consequently, the length of each supply pipe 444 can be shortened, thereby reducing the distance over which the toner is transported.

[0149] As a result, it is possible to reduce the size of the main unit while ensuring optimal toner supply to the developing unit 9.

[0150] <Third Embodiment> Characteristic features of the third embodiment of the present invention will be explained using Figures 28 and 29. Figure 28(a) shows a top view of the developing unit 9Y9, and Figure 28(b) shows a front view of the developing unit 9Y9. Figure 28(b) shows an assembly diagram along with the parts assembled to the developing unit 9Y9. Figure 29(a) shows an assembled perspective view of the developing unit 9Y9, and Figure 29(b) shows a perspective view of the developing unit 9Y9 after completion of assembly.

[0151] (Hole on the lid) As shown in Figure 28(b), the developing unit 9Y9 has a toner container 730 from which toner is supplied from a toner cartridge, which is a toner supply container, via a supply pipe 444Y, which is a toner supply tube. The toner container 730 consists of a toner container 730b that rotatably supports the developing roller 6Y, and a lid 730a that closes the opening of the toner container 730b. The lid 730a is welded and joined to the opening of the toner container 730b.

[0152] As shown in Figure 28(b), the lid 730a has through holes, specifically a first hole 731a, a second hole 731b, a third hole 731c, and a fourth hole 731d, at different positions on a virtual axis VA2 parallel to the rotation axis VA1 of the developing roller 6Y. The lid 730a also has protruding first cylindrical parts 732a, a second cylindrical part 732b, a third cylindrical part 732c, and a fourth cylindrical part 732d, corresponding to these through holes. As shown in Figure 28(a), the shapes of these holes and cylindrical parts are configured as having the same circular axis when viewed from above. Furthermore, the first cylindrical part 732a and the second cylindrical part 732b, and the third cylindrical part 732c and the fourth cylindrical part 732d are each arranged symmetrically with respect to the longitudinal center VF of the toner carrying area DA of the developing roller 8Y.

[0153] As shown in Figure 29(a), the replenishment pipe 444Y is attached to the first cylindrical portion 732a. The outer diameter of the first cylindrical portion 732a is set to be larger than the inner diameter of the replenishment pipe 444Y. The inner diameter of the replenishment pipe 444Y is elastically deformable and is assembled while expanding to correspond to the outer diameter of the cylindrical portion 732a. As a result, the gaps in the assembly parts (outer diameter and inner diameter) of each component are filled, and toner leakage to the outside from the assembly parts is prevented.

[0154] (Exhaust filter) A cap-shaped exhaust filter 762 is attached to the second cylindrical portion 732b by means of welding, bonding, or other means. This makes it easier for toner T and air to flow from the cartridge 430Y into the developing unit 9Y9 via the supply pipe 444Y, similar to the effect of the exhaust filter described above.

[0155] (Sealing cap) The third cylindrical portion 732c and the fourth cylindrical portion 732d are fitted with sealing caps 773 for sealing toner inside the toner container 730.

[0156] The sealing cap 773 is made of an elastic material and is assembled to cover the third cylindrical portion 732c and the fourth cylindrical portion 732d. The inner diameter of the sealing cap 773 is elastically deformable and is set to be smaller than the outer diameter of the third cylindrical portion 732c and the fourth cylindrical portion 732d. As a result, the inner diameter of the sealing cap 773 elastically deforms and expands relative to the outer diameter of the third cylindrical portion 732c and the fourth cylindrical portion 732d when assembled. Consequently, the gaps in the assembly portions (outer diameter and inner diameter) of each component are filled, preventing toner leakage to the outside from the assembly portions.

[0157] Figure 29(b) shows the developing unit 9Y9 with the supply pipe 444Y, exhaust filter 762, and sealing cap 773 assembled. The developing unit 9Y9 in this state is then assembled into the drum unit to complete the process cartridge (not shown).

[0158] In the longitudinal direction of the developing roller 6Y, the exhaust filter 762 is positioned in the second cylindrical section 732b, which is furthest from the first cylindrical section 732a where the supply pipe 444Y is located. In the longitudinal direction, the toner supply port and the air outlet are positioned as far apart as possible. As a result, airflow is generated in the longitudinal direction within the toner container 730, promoting toner circulation.

[0159] As described in the second embodiment, it is also possible to add an exhaust filter 762 to increase exhaust capacity. Similarly, the addition of a supply pipe 444 for supplying toner to both ends can also be adopted in this embodiment.

[0160] Furthermore, in other respects, the same effects as those described above can be obtained in the third embodiment as in the first and second embodiments.

[0161] To summarize, as shown in Figure 28(b), holes are provided in the lid 730a at different positions on a virtual axis VA2 parallel to the rotation axis VA1 of the developing roller 6Y. Corresponding to these holes, a first cylindrical section 732a, a second cylindrical section 732b, a third cylindrical section 732c, and a fourth cylindrical section 732d are provided in the lid 730a. As shown in Figure 28(a), the shapes of these holes and cylindrical sections are coaxial circular shapes when viewed from above.

[0162] This makes it possible to configure the lid 730 so that the supply pipe 444, exhaust filter 762, and sealing cap 773 are selectively positioned relative to each cylindrical section (732a, 732b, 732c, 732d) without increasing the number of parts in the lid 730.

[0163] Here, let's assume that the holes and shapes of the first cylindrical section 732a, the second cylindrical section 732b, the third cylindrical section 732c, and the fourth cylindrical section 732d are different. In such a case, the holes and mounting parts of the supply pipe 444, exhaust filter 762, and sealing cap 773 are made to correspond to these multiple holes and the different shapes of the cylindrical sections. With this configuration, they can be arranged selectively in the same way. However, it is preferable if the holes and cylindrical sections have the same shape, as this allows for a simpler design of the mounting parts of the supply pipe 444, exhaust filter 762, and sealing cap 773.

[0164] Furthermore, the first cylindrical section 732a and the second cylindrical section 732b, and the third cylindrical section 732c and the fourth cylindrical section 732d are each arranged symmetrically in pairs with respect to the longitudinal center VF of the toner-carrying area DA of the developing roller 8Y. This makes it easy to configure each replenishment pipe 444 to avoid each laser beam path L located in the longitudinal center. In addition, this arrangement allows each replenishment pipe 444 to be made shorter at both longitudinal ends.

[0165] As a result, it is possible to achieve optimal toner supply to the developing unit 9 while also miniaturizing the main unit.

[0166] The first embodiment shows an example configuration with two holes (711a, 711b) provided on the lid 710a. The second and third embodiments show an example configuration with four holes (721a, 721b, 721c, 721d, 731a, 731b, 731c, 731d) provided on the lids 720a and 730a.

[0167] The same effect as described above can be obtained even if these holes are provided on the side of the toner containers 710b, 720b, and 730b instead of the lid.

[0168] Furthermore, in the second and third embodiments, even if the fourth holes 721d and 722d are eliminated and three holes are arranged, the supply pipe 444 connected to the relay member 752, the exhaust filters (761, 762), and the sealing caps (772, 773) can be selectively arranged. Thus, the same effects as described above can be obtained.

[0169] Furthermore, the same effect can be obtained even if the toner is transported by a screw rather than compressed air. When the toner is transported by a screw, it is not necessarily required to provide an exhaust filter for exhausting compressed air.

[0170] Furthermore, the lid of the yellow toner container may be referred to as the first lid component, and the portion excluding the first lid component as the first container. The lid of the cyan toner container may be referred to as the second lid component, and the portion excluding the second lid component as the second container. The lid of the magenta toner container may be referred to as the third lid component, and the portion excluding the third lid component as the third container. The lid of the black toner container may be referred to as the fourth lid component, and the portion excluding the fourth lid component as the fourth container.

[0171] The first to third holes in the yellow lid may be referred to as the first through-hole, second through-hole, and fifth through-hole, in order from the LE side. The first to third holes in the cyan lid may be referred to as the third through-hole, fourth through-hole, and sixth through-hole, in order from the LE side. The first to third holes in the magenta lid may be referred to as the seventh through-hole, eighth through-hole, and ninth through-hole, in order from the LE side.

[0172] The axis of rotation of the yellow developing roller may be called the first axis of rotation, the axis of rotation of the cyan developing roller the second axis of rotation, the axis of rotation of the magenta developing roller the third axis of rotation, and the axis of rotation of the black developing roller the fourth axis of rotation.

[0173] Direction Y may be referred to as the first direction, direction X as the second direction, and direction Z as the third direction.

[0174] The end of the yellow toner container on the LE side may be called the first end, and the opposite end may be called the second end. The end of the cyan toner container on the LE side may be called the third end, and the opposite end may be called the fourth end. [Explanation of Symbols]

[0175] 1. Image forming apparatus 4 (4Y, 4M, 4C, 4K) Photosensitive Drum 6 (6Y, 6M, 6C, 6K) Developing Roller 8 (8Y, 8M, 8C, 8K, 8Y1) Drum Unit 9(9Y, 9M, 9C, 9K, 9Y1, 9Y2, 9C3, 9Y4, 9Y5, 9Y6, 9Y7, 9Y8, 9Y9) Development unit 444 (444Y, 444M, 444C, 444K, 444Ya, 444Yb) Refill Pipe 500 Image Forming Units 710, 720, 730 Toner Storage Containers 710a, 720a, 730a toner containers 710b, 720b, 730b lid 711a, 721a, 731a First hole 711b, 721b, 731b Second holes 712a, 712b ribs 721c, 731c Third hole 721d, 731d Fourth hole 722a Rib 723a Recess 732a First cylindrical section 732b Second cylindrical section 732c Third cylindrical section 732d Fourth cylindrical section 751, 752, 753 Intermediate members 751a, 752a, 771a, 772a Cylindrical groove 751b, 752b, 771b, 772b Container mounting section 751c, 752c Pipe mounting section 751d, 752d through hole 761 Exhaust filter 771, 772, 773 Sealing caps

Claims

1. A first toner container having a first outlet for discharging the first toner outside the first toner container, A second toner container is provided with a second outlet for containing a second toner and for discharging the second toner outside the second toner container, A first developing unit having a first developing container configured to contain the first toner, and a first developing roller configured to carry the first toner contained in the first developing container, A second developing unit having a second developing container configured to contain the second toner, and a second developing roller configured to carry the second toner contained in the second developing container, A first passage having one end communicating with the first discharge port of the first toner container and the other end communicating with the first developing container, the first passage for transporting the first toner discharged from the first discharge port toward the first developing container, A second passage having one end communicating with the second discharge port of the second toner container and the other end communicating with the second developing container, the second passage for transporting the second toner discharged from the second discharge port toward the second developing container, Equipped with, The first developing container includes a first frame that forms a first space for containing the first toner, and the first frame is provided with a first through hole and a second through hole. The second developing container includes a second frame having the same shape as the first frame, forming a second space for housing the second toner, and having a third through-hole and a fourth through-hole corresponding to the first through-hole and the second through-hole, respectively. The other end of the first passage communicates with the first space of the first developing container through the first through hole. The other end of the second passage communicates with the second space of the second developing container through the fourth through-hole. The second and third through holes are sealed. An image forming apparatus characterized by the following features.

2. The first developing container is a first container that forms the first space together with the first frame, and includes a first container that is located below the first frame and has a first opening that opens upward, The second developing container is a second container that forms the first space together with the second frame, and includes a second container provided below the second frame. The first frame is a first lid member that closes the opening of the first container, and the second frame is a second lid member that closes the opening of the second container. The image forming apparatus according to claim 1, further comprising the features described above.

3. The first developing roller is configured to be rotatable about a first rotation axis extending in a first direction, The second developing roller is configured to be rotatable about a second rotation axis extending in the first direction, The first through-hole and the second through-hole are provided at the first end and the second end opposite to the first end of the first developing container in the first direction, respectively. The third through-hole and the fourth through-hole are provided at the third end of the second developing container in the first direction, which is on the same side as the first end in the first direction, and at the fourth end on the opposite side of the third end, which is on the same side as the second end in the first direction. The image forming apparatus according to feature 1.

4. The first developing container and the second developing container are aligned in a second direction perpendicular to the first direction, The first toner container and the second toner container are aligned in the first direction, In the first direction, the first toner container is located closer to the first end than the second end, and the second toner container is located closer to the second end than the first end. The image forming apparatus according to feature 3.

5. A first pump that discharges air for transporting the first toner being transported in the first passage, A second pump that discharges air for transporting the second toner being transported in the second passage, The image forming apparatus according to claim 1, further comprising the features described above.

6. When viewed in the direction of the rotation axis of the rotation axis of the first developing roller, the first through hole and the second through hole are positioned to overlap. The image forming apparatus according to feature 1.

7. The first through hole and the second through hole have the same shape. The image forming apparatus according to feature 1.

8. A first filter for separating the air used to transport the first toner from the first toner and discharging it outside the first developing container, further comprising a first filter arranged to cover the second through-hole of the first lid member and configured to obstruct the passage of the first toner while allowing air to pass through. The image forming apparatus according to feature 2.

9. A third toner container is provided with a third outlet for containing a third toner and for discharging the third toner outside the third toner container, A third developing unit having a third developing container configured to contain the third toner, and a third developing roller configured to carry the third toner contained in the third developing container, A third passage having one end communicating with the third discharge port of the third toner container and the other end communicating with the third developing container, the third passage for transporting the third toner discharged from the third discharge port toward the third developing container, Furthermore, The first frame of the first developing container further has a fifth through hole, The second frame of the second developing container further has a sixth through hole, The third developing container includes a third frame having the same shape as the first frame, forming a third space for housing the third toner, and comprising a third frame provided with a seventh through-hole corresponding to the first through-hole, an eighth through-hole corresponding to the second through-hole, and a ninth through-hole corresponding to the fifth through-hole. The other end of the third passage is in communication with the third space of the third developing container through the ninth through-hole. The image forming apparatus according to feature 1.

10. The first developing container is provided with a sealing cap for sealing the fifth through-hole of the first frame. The image forming apparatus according to feature 9.

11. A first relay member is further provided between the other end of the first passage and the first through hole, The first relay member has an opening, and the other end of the first passage and the first through hole are in communication through the opening. The image forming apparatus according to feature 1.

12. A first pump that discharges air for transporting the first toner being transported in the first passage, Furthermore, The first frame of the first developing container is The fifth through-hole and A first filter for separating the air used to transport the first toner from the first toner and discharging it outside the first developing container, the first filter being positioned to cover the fifth through-hole and configured to obstruct the passage of the first toner while allowing air to pass through, Furthermore, The first through hole, the second through hole, and the fifth through hole are positioned at locations that coincide with a virtual line parallel to the rotation axis direction of the rotation axis of the first developing roller, and at different locations in the rotation axis direction. The image forming apparatus according to feature 1.

13. Because the first container and the second container have different shapes, the volume of the second space is larger than the volume of the first space. The image forming apparatus according to feature 2.

Images