Image forming apparatus

Abstract

To provide an image forming apparatus that can increase the degree of freedom in design of a channel and can suppress reduction in the airtightness of the channel.SOLUTION: An image forming apparatus comprises an air supply unit, and a channel forming unit that is formed to cause air to flow in the order of a first channel, a second channel, and a third channel. The channel forming unit includes a first member that has a first surface and a second surface intersecting each other with a ridge part therebetween, a second member that has a third surface, and a third member that has a fourth surface. The first channel is formed in a gap between the first surface and the third surface. The third channel is formed in a gap between the second surface and the third surface. The second channel is at least partially formed into a tunnel shape inside the first member. A first connection part where the first channel and the second channel are connected to each other, and a second connection part where the second channel and the third channel are connected to each other, are provided at positions separate from the ridge part.SELECTED DRAWING: Figure 7

Description

[Technical field]

[0001] The present invention relates to an image forming apparatus for forming an image on a recording material. [Background technology]

[0002] Patent Document 1 describes a method in which toner is replenished from a toner container to a developing device by air generated by an air pump. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2000-81778 A Summary of the Invention [Problem to be solved by the invention]

[0004] One method for forming an air flow path for transporting toner is to join a member with a groove on its surface to another member, thereby sealing the groove to form a flow path. In such a case, there has been a demand for a configuration that can increase the design freedom of the flow path and prevent a decrease in the airtightness of the flow path.

[0005] SUMMARY OF THE PRESENTLY PREFERRED EMBODIMENTS An object of the present invention is to provide an image forming apparatus that can increase the degree of freedom in designing a flow path and prevent a decrease in the airtightness of the flow path. [Means for solving the problem]

[0006] One aspect of the present invention is an image forming apparatus comprising: an air supply unit that supplies air for transporting toner; and a flow path forming unit formed so that the air supplied by the air supply unit flows in the order of a first flow path, a second flow path, and a third flow path, wherein the flow path forming unit includes a first member having a first surface and a second surface that intersect with each other across a ridge portion, a second member having a third surface, and a third member having a fourth surface, wherein the first flow path is formed in a gap between the first surface and the third surface, the third flow path is formed in a gap between the second surface and the third surface, at least a portion of the second flow path is formed in a tunnel shape inside the first member, and a first connection portion connecting the first flow path and the second flow path and a second connection portion connecting the second flow path and the third flow path are provided at a position away from the ridge portion. Effect of the Invention

[0007] According to the present invention, it is possible to provide an image forming apparatus that can increase the degree of freedom in designing the flow passages and prevent the sealing performance of the flow passages from decreasing. [Brief description of the drawings]

[0008] [Figure 1] 1 is a schematic diagram of an image forming apparatus according to a first embodiment. [Diagram 2] 1A to 1C are perspective views of an image forming apparatus according to a first embodiment. [Diagram 3] 1A and 1B are perspective views of an image forming unit according to a first embodiment. [Figure 4] 3A and 3B are top views of the image forming unit according to the first embodiment. [Diagram 5] 3A and 3B are cross-sectional views of an image forming unit according to the first embodiment. [Figure 6] 3A and 3B are exploded views of a cartridge holder according to the first embodiment. [Figure 7] 3A is a rear view, FIG. 3B is a bottom view, and FIG. 3C is a cross-sectional view of the cartridge holder according to the first embodiment. [Figure 8] 2A to 2E are explanatory views of the cartridge according to the first embodiment. [Figure 9] 1A to 1C are explanatory views of a cartridge according to a first embodiment. [Figure 10] 1A and 1B are explanatory views of a cartridge according to a first embodiment. [Figure 11] FIG. 11 is a cross-sectional view of a cartridge holder according to a second embodiment. [Figure 12] FIG. 11 is a cross-sectional view of a cartridge holder according to a third embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings.

[0010] In this disclosure, the term "image forming apparatus" refers to an apparatus generally having a function of forming an image on a sheet, which is a recording material (recording medium). The image forming apparatus may be a single-function printer, a copier, or a multifunction machine. The image forming apparatus may be an apparatus that mainly forms color images, or an apparatus that mainly forms monochrome images. The image forming apparatus may also be a system (image forming system) in which an accessory device used integrally with the image forming apparatus main body is connected to the image forming apparatus main body that forms an image on a recording material. Examples of the accessory device include a sheet processing device (finisher) that performs processing such as binding on sheets on which an image has been formed, a conveying device that conveys sheets from the image forming apparatus main body to another device, and a feeding device (optional feeder) that feeds sheets toward the image forming apparatus main body.

[0011] Example 1 An image forming apparatus 1 according to a first embodiment of the present disclosure will be described with reference to Fig. 1. Fig. 1 is a cross-sectional view of the image forming apparatus 1 cut along a plane perpendicular to the direction of the rotation axis of a photosensitive drum 4Y.

[0012] The image forming apparatus 1 is a full-color image forming apparatus (full-color laser printer) equipped with four-color process units. The image forming apparatus 1 can form a full-color image on a recording material S by an electrophotographic process. As the recording material S (recording medium), various sheet materials of different sizes and materials can be used, including paper such as plain paper and thick paper, surface-treated sheet materials such as coated paper, sheet materials of special shapes such as envelopes and index paper, plastic films, cloth, etc.

[0013] In the following description and drawings, the vertical direction (direction of gravity) when image forming apparatus 1 is placed on a horizontal surface is defined as the Z-axis direction. The direction of the rotation axis of a photosensitive drum (image carrier) included in image forming apparatus 1 is defined as the Y-axis direction. The direction intersecting both the Z-axis direction and the Y-axis direction is defined as the X-axis direction. The X-axis direction, Y-axis direction, and Z-axis direction are preferably perpendicular to each other.

[0014] The positive and negative directions along each coordinate axis are indicated by adding a + (plus) or - (minus) sign as necessary. For example, the positive direction of the X axis (the direction indicated by the X arrow in the figure) is the +X side or +X direction, and the negative direction of the X axis (the opposite side of the arrow) is the -X side or -X direction.

[0015] Further, elements such as cartridges that are detachable from the device body 72 of the image forming apparatus 1 will be described based on the posture of the element when it is attached to the device body 72.

[0016] As shown in Fig. 1, the image forming apparatus 1 includes process units PY, PM, PC, and PK, an intermediate transfer belt unit 11, and an apparatus main body 72. The process units PY, PM, PC, and PK are arranged to be aligned in the X-axis direction, and the toner colors contained therein are different from each other. Hereinafter, any one of the process units PY, PM, PC, and PK will be referred to as a process unit P. The longitudinal direction of each process unit P is the Y-axis direction. The process units PY, PM, PC, and PK will be referred to as a first process unit, a second process unit, a third process unit, and a fourth process unit, respectively.

[0017] Each process unit P has a process element for performing an electrophotographic process. A rotational driving force is transmitted to each process unit P from a drive output unit (not shown) of the device main body 72, and a bias voltage (charging bias, developing bias, etc.) is supplied from a bias application unit (not shown) of the device main body 72.

[0018] As shown in FIG. 1, the process units PY, PM, PC, and PK include drum units 8Y, 8M, 8C, and 8K, respectively. The drum units 8Y, 8M, 8C, and 8K include photosensitive drums 4Y, 4M, 4C, and 4K, and charging rollers 5Y, 5M, 5C, and 5K as process means acting on the photosensitive drums 4Y, 4M, 4C, and 4K, respectively. Hereinafter, any one of the drum units 8Y, 8M, 8C, and 8K will be referred to as a drum unit 8, any one of the photosensitive drums 4Y, 4M, 4C, and 4K will be referred to as a photosensitive drum 4, and any one of the charging rollers 5Y, 5M, 5C, and 5K will be referred to as a charging roller 5. Each photosensitive drum 4 is disposed so that the direction of its rotation axis is in the Y-axis direction, and is rotatable around the rotation axis. The photosensitive drums 4Y, 4M, 4C, and 4K are respectively a first photosensitive drum, a second photosensitive drum, a third photosensitive drum, and a fourth photosensitive drum.

[0019] The process units PY, PM, PC, and PK are each provided with a developing unit 9Y, 9M, 9C, and 9K having a developing roller 6Y, 6M, 6C, and 6K for developing the electrostatic latent image on the corresponding photosensitive drum 4. The developing units 9Y, 9M, 9C, and 9K are aligned in the X-axis direction. The developing rollers 6Y, 6M, 6C, and 6K are respectively referred to as a first developing roller, a second developing roller, a third developing roller, and a fourth developing roller. The developing units 9Y, 9M, 9C, and 9K are respectively referred to as a first developing unit, a second developing unit, a third developing unit, and a fourth developing unit. Hereinafter, any one of the developing units 9Y, 9M, 9C, and 9K will be referred to as a developing unit 9, and any one of the developing rollers 6Y, 6M, 6C, and 6K will be referred to as a developing roller 6.

[0020] The developing units 9Y, 9M, 9C, and 9K include developing containers 3Y, 3M, 3C, and 3K, respectively. Hereinafter, any one of the developing containers 3Y, 3M, 3C, and 3K will be referred to as the developing container 3. The developing unit 9Y has a developing container 3Y (first developing container) that contains yellow (Y) toner (first toner), and is configured so that the yellow toner is supplied to the surface of the photosensitive drum 4Y by a developing roller 6Y that carries the yellow toner. The developing unit 9M has a developing container 3M (second developing container) that contains magenta (M) toner (second toner), and is configured so that the magenta toner is supplied to the surface of the photosensitive drum 4M by a developing roller 6M that carries the magenta toner. The developing unit 9C has a developing container 3C (third developing container) that contains cyan (C) toner (third toner), and is configured so that the cyan toner is supplied to the surface of the photosensitive drum 4C by a developing roller 6C that carries the cyan 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 toner is supplied to the surface of the photosensitive drum 4K by a developing roller 6K that carries the black toner.

[0021] In the Z-axis direction intersecting both the X-axis direction and the Y-axis direction, a laser scanner unit LB (exposure unit) is provided above the process units PY, PM, PC, and PK (photosensitive drums 4Y, 4M, 4C, and 4K). This laser scanner unit LB outputs laser light corresponding to image information. Hereinafter, the optical paths of the laser light toward the photosensitive drums 4Y, 4M, 4C, and 4K are referred to as LY, LM, LC, and LK, respectively. The laser light irradiated from the laser scanner unit LB scans and exposes the surfaces of the photosensitive drums 4Y, 4M, 4C, and 4K. An LED exposure unit may be used instead of the laser scanner unit LB.

[0022] Below the process unit P in the Z-axis direction, an intermediate transfer belt unit 11 including a transfer belt 12 as a transfer member (intermediate transfer body) is provided. The intermediate transfer belt unit 11 has a drive roller 14, a tension roller 13, and an assist roller 15. The flexible endless transfer belt 12 is stretched around these rollers.

[0023] The lower surface of each photosensitive drum 4 contacts the upper surface of the transfer belt 12. The contact portions between the photosensitive drums 4Y, 4M, 4C, and 4K and the transfer belt 12 are primary transfer portions 30Y, 30M, 30C, and 30K (hereinafter referred to as primary transfer portion 30). Primary transfer rollers 16Y, 16M, 16C, and 16K (hereinafter referred to as transfer rollers 16) are provided on the inner side of the transfer belt 12 so as to face the photosensitive drums 4Y, 4M, 4C, and 4K.

[0024] A secondary transfer roller 17 is pressed against the drive roller 14 with the transfer belt 12 sandwiched therebetween. The contact portion between the transfer belt 12 and the secondary transfer roller 17 is a secondary transfer portion 31. The secondary transfer portion 31 is a transfer portion where an image (toner image) is transferred to the recording material S by the image forming portion 1A.

[0025] The process units PY, PM, PC, PK and the intermediate transfer belt unit 11 constitute a tandem type intermediate transfer type image forming section 1A as an image forming means in this embodiment. The image forming section 1A forms an image (developer image) using toner (developer) contained in developing containers 3Y, 3M, 3C, 3K as containers.

[0026] A feeding unit 18 is provided in the lower part of the device body 72 (below the intermediate transfer belt unit 11 in the Z-axis direction). The feeding unit 18 has a feeding tray 19 (sheet storage section) that stacks and stores the recording material S, and a feeding roller 20 as a feeding member that picks up the recording material S from the feeding tray 19 and transports it.

[0027] At the top of the device main body 72, there are provided a fixing unit 21 for fixing the toner image on the recording material S, and a discharge roller 22 as a discharge member for discharging the recording material S with the fixed toner image to a discharge tray 23. The discharge roller 22 discharges the recording material S in a direction along the X-axis direction. The fixing unit 21 has a pair of rotating bodies forming a nip portion (fixing nip) for sandwiching and transporting the recording material S, and a heating means (a halogen lamp or a ceramic heater) for heating the toner image on the recording material S. In this embodiment, the downstream side of the discharge direction in which the recording material S is discharged toward the discharge tray 23 by the discharge roller 22 is the front side of the image forming apparatus 1, and the upstream side of the discharge direction is the rear side of the image forming apparatus 1. The front side of the image forming apparatus 1 is the +X side in the X-axis direction, and the rear side is the -X side in the X-axis direction.

[0028] Each process unit P may be a process cartridge that is detachable from the apparatus main body 72. Also, among each process unit P, only the developing unit 9 may be a unit that is detachable from the apparatus main body 72 (developing cartridge).

[0029] [Image formation operation] The operation for forming a full-color image is as follows: The photosensitive drums 4Y, 4M, 4C, and 4K are rotated at a predetermined speed in a counterclockwise direction in Fig. 1. The transfer belt 12 is rotated at a speed corresponding to the rotational speed (circumferential speed) of the photosensitive drums 4Y, 4M, 4C, and 4K in a rotation direction following the rotation of the photosensitive drums 4Y, 4M, 4C, and 4K.

[0030] The laser scanner unit LB is also driven. In synchronization with the driving of the laser scanner unit LB, the charging roller 5 in each process unit P uniformly charges the surface of the photosensitive drum 4 to a predetermined polarity and potential. The laser scanner unit LB scans and exposes the surfaces of the charged photosensitive drums 4Y, 4M, 4C, and 4K with laser beams LY, LM, LC, and LK in accordance with the image signals of each color, and writes electrostatic latent images in accordance with the image signals of each color on the surfaces of the photosensitive drums 4Y, 4M, 4C, and 4K. That is, the laser scanner unit LB exposes the photosensitive drums 4Y and 4M to light, and forms a first electrostatic latent image and a second electrostatic latent image on the photosensitive drums 4Y and 4M, respectively. Similarly, the laser scanner unit LB exposes the photosensitive drums 4C and 4K to light, and forms a third electrostatic latent image and a fourth electrostatic latent image on the photosensitive drums 4C and 4K, respectively.

[0031] The electrostatic latent image on each photosensitive drum 4 is developed by supplying toner to the photosensitive drum 4 by the developing roller 6, which is driven to rotate clockwise in FIG. 1 at a predetermined speed. By the electrophotographic image forming process described above, a yellow toner image is formed on the photosensitive drum 4Y of the process unit PY. Then, the yellow toner image is primarily transferred onto the transfer belt 12. Similarly, a magenta toner image is formed on the photosensitive drum 4M of the process unit PM. Then, the magenta toner image is primarily transferred onto the transfer belt 12 so as to be superimposed on the yellow toner image on the transfer belt 12. A cyan toner image is formed on the photosensitive drum 4C of the process unit PC. Then, the cyan toner image is primarily transferred onto the transfer belt 12 so as to be superimposed on the yellow and magenta toner images on the transfer belt 12. A black toner image is formed on the photosensitive drum 4K of the process unit PK. Then, the black toner image is primarily transferred onto the transfer belt 12 so as to be superimposed on the yellow, magenta, and cyan toner images on the transfer belt 12.

[0032] In this way, a full-color unfixed toner image of four colors, yellow, magenta, cyan, and black, is formed on the transfer belt 12. Meanwhile, at a predetermined control timing, the recording material S is separated one by one from the feed tray 19 by the feed roller 20 and fed. The recording material S is introduced into the secondary transfer section 31, which is the contact portion between the secondary transfer roller 17 and the transfer belt 12, at a predetermined control timing. In the process of the recording material S being conveyed through the secondary transfer section 31, the four-color superimposed toner image on the transfer belt 12 is transferred onto the recording material S. The recording material S onto which the toner image has been transferred is heated and pressurized by the fixing unit 21, and the toner image is fixed onto the recording material S. The recording material S onto which the toner image has been fixed is discharged to the discharge tray 23 by the discharge roller 22.

[0033] [Installation and removal of toner cartridges] The arrangement of the toner cartridges will be described with reference to Fig. 2. Image forming apparatus 1 has cartridges 430Y, 430M, 430C, and 430K as supply containers detachable from apparatus main body 72. Any one of cartridges 430Y, 430M, and 430C will be referred to as cartridge 430 below.

[0034] The cartridges 430Y, 430M, 430C, and 430K are aligned in a direction intersecting (orthogonal to) the direction in which the developing units 9 are aligned. In this embodiment, the cartridges 430Y, 430M, 430C, and 430K are aligned in the Y-axis direction. The cartridges 430Y, 430M, 430C, and 430K are respectively referred to as a first cartridge (first toner container), a second cartridge (second toner container), a third cartridge (third toner container), and a fourth cartridge (fourth toner container).

[0035] Fig. 2(a) is a perspective view of the image forming apparatus 1 with the front door 72b closed. Fig. 2(b) is a perspective view of the image forming apparatus 1 with the front door 72b open. Fig. 2(c) is a perspective view of the image forming apparatus 1 with the front door 72b open and the cartridge 430Y removed from the cartridge holder 51.

[0036] As shown in FIG. 2(b), the cartridges 430Y, 430M, 430C, and 430K are mounted on the upper part of the front side of the device body 72 so that each cartridge 430 can be accessed by opening the front door 72b. In other words, each cartridge 430 is provided at an end of the device body 72 downstream of the discharge roller 22 in the discharge direction. The front door 72b is an opening / closing member configured to be movable between a closed position (see FIG. 2(a)) that closes the opening of the device body 72 on the front side, and an open position (see FIG. 2(b)) that opens the opening. 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, as shown in FIG. 2(b).

[0037] The cartridges 430Y, 430M, 430C, and 430K are arranged in line in the Y-axis direction, and are configured to be detachable in the X-axis direction with respect to the device main body 72 as shown in FIG. 2(c). This allows the process units PY, PM, PC, and PK to be replenished with toner without removing the process units PY, PM, PC, and PK from the device main body 72. By arranging each cartridge 430 on the front side of the image forming device 1, each cartridge 430 can be accessed from the front side, as in the case of collecting the recording material S discharged to the discharge tray 23. In addition, since the cartridge holder 51 is located on the front side of the image forming device 1, the process unit P is not exposed even after each cartridge 430 is removed (see FIG. 2(c)). Each cartridge 430 is stored in the device main body 72 with the front door 72b closed.

[0038] As shown in FIG. 2(a), indicators 208Y, 208M, 208C, and 208K (marking units, display units) of each color are provided on the front side of the image forming apparatus 1. The indicators 208Y, 208M, 208C, and 208K are arranged in the Y-axis direction to correspond to the cartridges 430Y, 430M, 430C, and 430K. The indicator 208Y (first indicator) is yellow, the indicator 208M (second indicator) is magenta, the indicator 208C (third indicator) is cyan, and the indicator 208K (fourth indicator) is black. Each of the indicators 208Y, 208M, 208C, and 208K is composed of an LED or a sticker of a color corresponding to the color of the toner of the corresponding cartridge 430, and is provided to prevent the cartridge 430 from being erroneously installed. Furthermore, each of the indicators 208Y, 208M, 208C, and 208K may have a display function for displaying the remaining amount of toner in the corresponding process unit P (developing unit 9).

[0039] As shown in FIG. 2(b), the device main body 72 has an inclined portion 51a provided on the lower side of the cartridge holder 51. The inclined portion 51a is a slope that faces obliquely upward toward the front side of the image forming device 1. In other words, the inclined portion 51a is inclined with respect to the horizontal plane so as to extend downward (-Z side) toward the front side (+X side) of the image forming device 1. A label 210 corresponding to the color of the toner of the cartridges 430Y, 430M, 430C, and 430K is attached to the inclined portion 51a. When a user replaces each cartridge, the user can visually check the label 210 on the inclined portion 51a, and therefore can install each cartridge 430 in a predetermined position.

[0040] [Image forming unit] The toner transport mechanism from each cartridge 430 to the corresponding process unit P will be described with reference to FIGS. 3(a) to 5(b).

[0041] A unit including the cartridges 430Y, 430M, 430C, and 430K, the process units PY, PM, PC, and PK, and a toner transport path described later is referred to as the image forming unit 50. The toner transport path is a toner transport path (toner transport mechanism) from each cartridge 430 to the corresponding process unit P.

[0042] FIG. 3(a) is a perspective view of the image forming unit 50 with the cartridges 430Y, 430M, 430C, and 430K attached. FIG. 3(b) is a perspective view of the image forming unit with the cartridges 430Y, 430M, 430C, and 430K removed. FIG. 4(a) is a top view of the laser scanner unit LB and the image forming unit 50. FIG. 4(b) is a top view of the image forming unit 50. FIGS. 5(a) and 5(b) are cross-sectional views showing the AA and BB sections of FIG. 4(a), respectively. In FIGS. 3(a) to 5(b), the front side (+X side) of the image forming apparatus 1 is designated as "FE" and the rear side (-X side) is designated as "BE". When the image forming apparatus 1 is viewed from the front side toward the rear side, the right end side (+Y side) is designated as "RE" and the left end side (-Y side) is designated as "LE".

[0043] 3(a), in the image forming unit 50, process units PY, PM, PC, and PK are arranged side by side in the X direction. Each process unit P is attached to a tray 55. A cartridge holder 51 is provided in front of the tray 55, and cartridges 430Y, 430M, 430C, and 430K are attached to the cartridge holder 51. The cartridges 430Y, 430M, 430C, and 430K are arranged side by side in the Y direction.

[0044] That is, the device main body 72 has a cartridge holder 51 as a holding member (a mounting portion on which the cartridge 430 is mounted) that holds each cartridge 430. The cartridge holder 51 forms a mounting space in which each cartridge 430 is mounted. The mounting space in this embodiment is the space between the cartridge holder 51 and the front door 72b in the closed state (FIGS. 1 and 2(a)). The cartridge holder 51 is fixed to the frame of the device main body 72. The cartridge holder 51 may be a part of the frame of the device main body 72.

[0045] A pump unit 80 is provided above the process unit PK. The pump unit 80 is supported by a support member 56 and attached to the cartridge holder 51. The pump unit 80 includes four air pumps for sending air to the cartridges 430Y, 430M, 430C, and 430K, respectively. A positive displacement pump such as a reciprocating pump or a rotary pump is used for each pump unit 80. A reciprocating pump is a pump that performs suction and discharge by the reciprocating motion of a piston or a plunger, and includes a piston pump, a plunger pump, and a diaphragm pump. A rotary pump is a pump that performs suction and discharge by rotating a gear or a rotor, and includes a gear pump, a screw pump, and a vane pump.

[0046] In this embodiment, the pump unit 80 is provided in the image forming unit 50, but may be provided in each cartridge 430 or another portion of the apparatus main body 72. The pump unit 80 (air pump) is an example of an air supply portion or supply means that supplies air to transport toner from each cartridge 430 to the developing unit 99, and for example, a fan (axial fan, sirocco fan, etc.) may be used as the air supply portion.

[0047] [Cartridge holder] FIG. 6(a) is an exploded perspective view (viewed from the front side) of the cartridge holder 51. FIG. 6(b) is an exploded perspective view (viewed from the rear side) of the cartridge holder 51. FIG. 7(a) is a view of the cartridge holder 51 as viewed from the rear side (-X side). FIG. 7(b) is a view (bottom view) of the cartridge holder 51 as viewed from the lower side (-Z side). FIG. 7(c) is a cross-sectional view of the cartridge holder 51 taken along line AA in FIG. 7(a).

[0048] As shown in Figs. 6(a)(b) and 7(a)(b), the cartridge holder 51 has a holder body 510, connection members 52a, 52b, 52c, 52d, and a bottom cover 53. The holder body 510 is an example of a first member, the connection member 52a is an example of a second member, and the bottom cover 53 is an example of a third member. The holder body 510, the connection members 52a, 52b, 52c, 52d, and the bottom cover 53 are formed as one unit joined by a method such as adhesion. The holder body 510, the connection members 52a, 52b, 52c, 52d, and the bottom cover 53 may all be resin molded products molded by a method such as injection molding.

[0049] The cartridge holder 51 is an example of a flow path forming part that forms a flow path through which air flows to supply toner from the cartridge 430 as a supply container to the corresponding developing container 3 (container). The cartridge holder 51 of this embodiment forms an installation space in which the cartridge 430 is installed, and is a holding member that holds the cartridge 430, and is also a flow path forming part that forms a flow path for air.

[0050] The cartridge holder 51 has air connection ports 521, 522, 523, and 524, and air discharge ports 514a, 514b, 514c, and 514d. The cartridge holder 51 further has toner receiving ports 515a, 515b, 515c, and 515d, and toner connection ports 525, 526, 527, and 528.

[0051] The air connection port 521 and the air discharge port 514a are connected via an air flow path 57a in the cartridge holder 51. The air connection port 522 and the air discharge port 514b are connected via an air flow path 57b in the cartridge holder 51. The air connection port 523 and the air discharge port 514c are connected via an air flow path 57c in the cartridge holder 51. The air connection port 524 and the air discharge port 514d are connected via an air flow path 57d in the cartridge holder 51. These air flow paths 57a, 57b, 57c, and 57d are paths through which air supplied from the pump unit 80 (air supply section) flows toward each cartridge 430 (refill container).

[0052] The cartridge holder 51 is configured so that air supplied from the pump unit 80 flows through an upstream portion 57a1 (first flow path), an internal flow path 512a (second flow path), and a downstream portion 57a2 (third flow path) of an air flow path 57a, which will be described later, in that order. The cartridge holder 51 is also configured so that air supplied from the pump unit 80 flows through an upstream portion (fourth flow path), an internal flow path 512b (fifth flow path), and a downstream portion (sixth flow path) of an air flow path 57b, in that order, in a path independent of the air flow path 57a. Similarly, the cartridge holder 51 is configured so that air supplied from the pump unit 80 flows through an upstream portion, an internal flow path 512c, and a downstream portion of an air flow path 57c, in that order. The cartridge holder 51 is also configured so that air supplied from the pump unit 80 flows through an upstream portion, an internal flow path 512d, and a downstream portion of an air flow path 57d, in that order, in a path independent of the air flow path 57c.

[0053] When the cartridge 430Y is attached to the cartridge holder 51, the air discharge port 514a is connected to a receiving port 430Yb1 (described later) of the cartridge 430Y, and the toner receiving port 515a is connected to a discharge port 430Ya1 of the cartridge. When the cartridge 430M is attached to the cartridge holder 51, the air discharge port 514b is connected to a receiving port 430Mb1 (described later) of the cartridge 430M, and the toner receiving port 515b is connected to a discharge port 430Ma1 of the cartridge. When the cartridge 430C is attached to the cartridge holder 51, the air discharge port 514c is connected to a receiving port 430Cb1 (described later) of the cartridge 430C, and the toner receiving port 515c is connected to a discharge port 430Ca1 of the cartridge. When the cartridge 430K is attached to the cartridge holder 51, the air outlet 514d is connected to a receiving port 430Kb1 (described later) of the cartridge 430K, and the toner receiving port 515d is connected to a discharge port 430Ka1 of the cartridge.

[0054] Toner receiving port 515a and toner connection port 525 are connected via a toner flow path in cartridge holder 51. Toner receiving port 515b and toner connection port 526 are connected via a toner flow path in cartridge holder 51. Toner receiving port 515c and toner connection port 527 are connected via a toner flow path in cartridge holder 51. Toner receiving port 515d and toner connection port 528 are connected via a toner flow path in cartridge holder 51. These toner flow paths are paths through which air containing toner discharged from each cartridge 430 flows toward the corresponding developing unit 9.

[0055] That is, the cartridge holder 51 has, as a structure for transporting toner from the cartridge 430Y using air, an air flow path 57a including an air connection port 521 and an air discharge port 514a, and a toner flow path including a toner receiving port 515a and a toner connection port 525. The cartridge holder 51 has, as a structure for transporting toner from the cartridge 430M using air, an air flow path 57b including an air connection port 522 and an air discharge port 514b, and a toner flow path including a toner receiving port 515b and a toner connection port 526. The cartridge holder 51 has, as a structure for transporting toner from the cartridge 430C using air, an air flow path 57c including an air connection port 523 and an air discharge port 514c, and a toner flow path including a toner receiving port 515c and a toner connection port 527. The cartridge holder 51 has an air flow path 57d including an air connection port 524 and an air discharge port 514d, and a toner flow path including a toner receiving port 515d and a toner connection port 528 as a structure for transporting toner from the cartridge 430K using air.

[0056] The air connection port 521 is an example of a first opening for receiving air supplied from an air supply unit. The air exhaust port 514a is an example of a second opening that is connected to an opening (a receiving port 430Yb1 described later) provided in the supply container for taking in air.

[0057] [Air supply path from pump to cartridge] Hereinafter, the air supply paths from the pump unit 80 to each cartridge 430 will be described in detail with reference to FIGS. 5(a) and (b), 6(a) and (b), and 7(a) to (c).

[0058] 5(a) and (b), the four outlets of the pump unit 80 are respectively connected to the air connection ports 521, 522, 523, and 524 of the cartridge holder 51 by four air supply pipes 61. Although only one air supply pipe 61Y connected to the air connection port 521 is shown in FIGS. 5(a) and (b), the other three outlets of the pump unit 80 are respectively connected to the air connection ports 522, 523, and 524 via the corresponding three air supply pipes 61. The air supply pipe 61Y is a flexible cylindrical member (tube) having one end connected to the pump unit 80 (air supply section) and the other end connected to the air connection port 521 (first opening).

[0059] The outer diameter of the air connection port 521 is slightly larger than the inner diameter of the end 61Yu of the air supply pipe 61Y (FIG. 5(b)). The end 61Yu of the air supply pipe 61Y is connected to the air connection port 521 by press-fitting. This makes it possible to prevent air leakage from the connection portion between the air supply pipe 61Y and the air connection port 521. Similarly, the outer diameters of the air connection ports 522, 523, 524 are slightly larger than the inner diameters of the corresponding ends of the air supply pipe 61.

[0060] (1. Air supply path to cartridge 430Y) First, the air supply path to the cartridge 430Y will be described in detail. As shown in FIG. 6(a)(b), the air connection port 521 is provided in the connection member 52a. The holder body 510 (first member) has a flat surface 51f (first surface, first flat surface) facing the connection member 52a. The connection member 52a (second member) has a flat surface 52a1 (third surface, third flat surface) facing the holder body 510. In this embodiment, the connection member 52a is joined to the holder body 510 by bonding the flat surfaces 51f and 52a1 with an adhesive. The flat surface 51f of the holder body 510 and the flat surface 52a1 of the connection member 52a are substantially parallel surfaces. In this embodiment, the flat surfaces 51f and 52a1 extend in a direction intersecting with the X-axis direction. The flat surface portion 51f of the holder main body 510 is a surface facing one side (-X side) in the X-axis direction, and the flat surface portion 52a1 of the connection member 52a is a surface facing the other side (+X side) in the X-axis direction.

[0061] A groove 511a (first groove) is formed in the flat surface 51f of the holder body 510. The groove 511a has a groove shape (concave shape) that is recessed in a direction away from the flat surface 52a1 (+X direction in this embodiment) in a direction in which the flat surface 51f and the flat surface 52a1 of the connection member 52a face each other (a direction perpendicular to the flat surface 52a1, approximately in the X-axis direction). When the holder body 510 and the connection member 52a are joined, the groove 511a is covered by the flat surface 52a1 of the connection member 52a. This forms an upstream portion 57a1 (FIGS. 7(a)(c), first flow path) of the air flow path 57a.

[0062] In other words, one of the first surface and the third surface is provided with a first groove portion recessed in a direction away from the other of the first surface and the third surface in a first direction in which the first surface and the third surface face each other. The first groove portion forms a first portion of the flow path by being covered by the first member or the second member having the other of the first surface and the third surface. The groove portion 511a as the first groove portion in this embodiment is provided in the flat surface portion 51f of the holder main body 510 as the first surface of the first member, but as shown in Example 2 described later, the first groove portion may be provided in the flat surface portion 52a1 of the connection member 52a (the third surface of the second member). In other words, the upstream portion 57a1 (first flow path) of the air flow path 57a is a space formed in a gap between the flat surface portion 51f (first surface) of the holder main body 510 and the flat surface portion 52a1 (the third surface) of the connection member 52a. The "gap" may be a gap formed when a groove portion provided on either the first surface or the third surface is covered by the other of the first surface or the third surface, or a gap formed when groove portions provided on both the first surface and the third surface face each other.

[0063] At least a part of the groove 511a extends in a direction intersecting with the lower surface portion 51b (second surface, second flat surface portion) described later. This allows the air flow path 57a to extend in a direction different from the in-plane direction of the lower surface portion 51b. The groove 511a in this embodiment extends substantially along the Z-axis direction (FIG. 7(a)). Note that the extension direction of the groove 511a may be changed as long as it is in the in-plane direction of the flat surface portion 51f, or the groove 511a may be bent one or more times within the plane of the flat surface portion 51f.

[0064] Furthermore, a hole 521a (FIG. 6(a)) is provided in the flat surface portion 52a1 of the connection member 52a at a position facing the end (upper end) of the groove portion 511a. The hole 521a communicates with the air connection port 521 via a flow path formed inside the connection member 52a. When the holder body 510 and the connection member 52a are joined, the hole 521a faces the end of the groove portion 511a. This allows the air connection port 521 to communicate with an upstream portion 57a1 of the air flow path 57a.

[0065] Further, the holder body 510 (first member) has a lower surface portion 51b which is a flat surface portion (second surface, second flat surface portion) facing the bottom cover 53. The lower surface portion 51b is a flat surface portion intersecting with the flat surface portion 51f at the ridge portion R1. The bottom cover 53 (third member) has an upper surface portion 53b which is a flat surface portion (fourth surface, fourth flat surface portion) facing the holder body 510. In this embodiment, the bottom cover 53 is joined to the holder body 510 by bonding the upper surface portion 53b to the lower surface portion 51b of the holder body 510 with an adhesive. The lower surface portion 51b of the holder body 510 and the upper surface portion 53b of the bottom cover 53 are substantially parallel surfaces. The lower surface portion 51b and the upper surface portion 53b of the bottom cover 53 in this embodiment spread in a direction intersecting with the Z-axis direction. The lower surface 51b of the holder body 510 is a surface facing one side (-Z side, downward) in the Z axis direction, and the upper surface 53b of the bottom cover 53 is a surface facing the other side (+Z side, upward) in the Z axis direction.

[0066] A groove 513a (second groove) is formed in the lower surface 51b of the holder body 510. The groove 513a has a groove shape (concave shape) that is recessed in a direction away from the upper surface 53b (+Z direction in this embodiment) in a direction in which the lower surface 51b and the upper surface 53b of the bottom cover 53 face each other (a direction perpendicular to the lower surface 51b, approximately the Z-axis direction). When the holder body 510 and the bottom cover 53 are joined together, the groove 513a is covered by the upper surface 53b of the bottom cover 53. This forms a downstream portion 57a2 of the air flow path 57a (FIGS. 7(b)(c), the second portion of the flow path).

[0067] In other words, one of the second surface and the fourth surface is provided with a second groove portion recessed in a direction away from the other of the second surface and the fourth surface in a second direction in which the second surface and the fourth surface face each other. The second groove portion forms a second portion of the flow path by being covered by the first member or the third member having the other of the second surface and the fourth surface. The groove portion 513a as the second groove portion in this embodiment is provided in the lower surface portion 51b of the holder main body 510 as the second surface of the first member, but as shown in Example 2 described later, the second groove portion may be provided in the upper surface portion 53b of the bottom cover 53 (the fourth surface of the third member). In other words, the downstream portion 57a2 (the third flow path) of the air flow path 57a is a space formed in a gap between the lower surface portion 51b (the second surface) of the holder main body 510 and the upper surface portion 53b (the fourth surface) of the bottom cover 53. The "gap" may be a gap formed when a groove portion provided on either the second surface or the fourth surface is covered by the other of the second surface or the fourth surface, or a gap formed when groove portions provided on both the second surface and the fourth surface face each other.

[0068] At least a part of the groove 513a extends in a direction intersecting with the flat surface portion 51f (first surface, first flat surface portion). This allows the air flow path 57a to extend in a direction different from the in-plane direction of the flat surface portion 51f. The groove 513a in this embodiment extends along the lower surface portion 51b, approximately along the X-axis direction (FIG. 7(b)). Note that the extension direction of the groove 513a may be changed as long as it is in the in-plane direction of the lower surface portion 51b, or the groove 513a may be bent one or more times within the plane of the lower surface portion 51b.

[0069] Also, an end (the end on the +X side) of groove 513a communicates with air exhaust port 514a through a hole formed in holder body 510 (FIG. 7(c)). Therefore, when holder body 510 and bottom cover 53 are joined, downstream portion 57a2 of air flow path 57a communicates with air exhaust port 514a.

[0070] In this way, by providing the grooves 511a and 513a on two surfaces (flat surface portion 51f and lower surface portion 51b) of the holder main body 510, it is possible to form the air flow path 57a in a curved shape that cannot be realized within a single plane. Specifically, in this embodiment, by providing the groove 511a extending approximately in the Z-axis direction on the flat surface portion 51f, it is possible to connect the air connection port 521 and the air exhaust port 514a, which are located at different positions in the Z-axis direction, with the air flow path 57a. Also, by providing the groove 513a extending approximately in the X-axis direction on the lower surface portion 51b, it is possible to connect the air connection port 521 and the air exhaust port 514a, which are located at different positions in the X-axis direction, with the air flow path 57a.

[0071] Furthermore, the holder body 510 is provided with an internal flow passage 512a that communicates the groove portion 511a and the groove portion 513a. The internal flow passage 512a is formed in a tunnel shape inside the holder body 510. One end of the internal flow passage 512a opens into the groove portion 511a at a position away from the ridge portion R1 between the flat surface portion 51f and the lower surface portion 51b of the holder body 510 in the Z-axis direction. The other end of the internal flow passage 512a opens into the groove portion 513a at a position away from the ridge portion R1 of the holder body 510 in the X-axis direction. This makes it easier to improve the sealing of the air flow passage 57a. The opening 512a1 of the internal flow passage 512a relative to the groove portion 511a is a first connection portion that connects the upstream portion 57a1 (first flow passage) of the air flow passage 57a and the internal flow passage 512a (second flow passage). An opening 512a2 of the internal flow path 512a relative to the groove portion 513a is a second connection portion that connects the internal flow path 512a (second flow path) and a downstream portion 57a2 (third flow path) of the air flow path 57a.

[0072] In other words, the internal flow path 512a is configured to connect the upstream portion 57a1 and the downstream portion 57a2 of the air flow path 57a via a path that bypasses the ridgeline R1 and passes through the inside of the holder main body 510. An end 511a1 (FIG. 7(c)) of the groove 511a that is closer to the ridgeline R1 is provided at a position away from the ridgeline R1 in the Z-axis direction. An end 513a1 (FIG. 7(c)) of the groove 513a that is closer to the ridgeline R1 is provided at a position away from the ridgeline R1 in the X-axis direction. In other words, the grooves 511a and 513a are formed so as not to reach the ridgeline R1.

[0073] When viewed in a first direction (approximately the X-axis direction) in which the flat surface portion 51f of the holder body 510 and the flat surface portion 52a1 of the connection member 52a face each other, it is preferable that there is an area between the groove portion 511a and the ridge portion R1 where the flat surface portion 51f and the flat surface portion 52a1 are in contact with each other. In other words, it is preferable that the upstream portion 57a1 (first flow path) of the air flow path 57a and the ridge portion R1 are separated by an area where the flat surface portion 51f (first surface) and the flat surface portion 52a1 (third surface) are in contact with each other. In addition, when viewed in a second direction (approximately the Z-axis direction) in which the lower surface portion 51b of the holder body 510 and the upper surface portion 53b of the bottom cover 53 face each other, it is preferable that there is an area between the groove portion 513a and the ridge portion R1 where the lower surface portion 51b and the upper surface portion 53b are in contact with each other. That is, it is preferable that downstream portion 57a2 (third flow path) of air flow path 57a and ridge portion R1 are separated by an area where lower surface portion 51b (second surface) and upper surface portion 53b (fourth surface) abut. This can more reliably improve the sealing performance of air flow path 57a. When viewed in the first direction, it is more preferable that the entire circumference of groove portion 511a is surrounded by the abutment area between flat surface portion 51f and flat surface portion 52a1. When viewed in the second direction, it is more preferable that the entire circumference of groove portion 513a is surrounded by the abutment area between lower surface portion 51b and upper surface portion 53b.

[0074] In this embodiment, the internal flow path 512a is formed in an approximately L-shape, including a portion extending in approximately the +X direction from an end 511a1 closer to the ridge portion R1 of the groove portion 511a, and a portion extending in approximately the +Z direction from an end 513a1 closer to the ridge portion R1 of the groove portion 513a.

[0075] As a molding method for the holder body 510, it is possible to perform injection molding with the opening and closing direction of a mold being approximately in the X-axis direction, based on the posture when attached to the device body 72. In this case, the groove portion 513a, a part of the internal flow path 512a, and the air exhaust port 514a are undercut, but it is possible to remove them from the mold by using a slide core that slides in the Z-axis direction, for example.

[0076] (2. Air supply path to cartridge 430M) The air supply path to the cartridge 430M is basically the same as the air supply path to the cartridge 430Y.

[0077] 6(a) and 6(b), the air connection port 522 is provided in the connection member 52a. A groove 511b is formed in the flat surface portion 51f of the holder body 510. When the holder body 510 and the connection member 52a are joined, the groove 511b is covered by the flat surface portion 52a1 of the connection member 52a. This forms an upstream portion of the air flow path 57b (a first portion of the flow path).

[0078] The grooves 511b in this embodiment extend substantially along the Z-axis direction (FIG. 7(a)). Note that the extension direction of the grooves 511b may be changed as long as it is within the in-plane direction of the flat surface portion 51f, and the grooves 511b may be bent one or more times within the plane of the flat surface portion 51f.

[0079] Furthermore, a hole 522a (FIG. 6(a)) is provided in the flat surface portion 52a1 of the connection member 52a at a position facing the end (upper end) of the groove portion 511b. The hole 522a communicates with the air connection port 522 via a flow path formed inside the connection member 52a. When the holder body 510 and the connection member 52a are joined, the hole 522a faces the end of the groove portion 511b. This allows the air connection port 522 to communicate with the upstream portion of the air flow path 57b.

[0080] A groove 513b is formed in the lower surface 51b of the holder body 510. When the holder body 510 and the bottom cover 53 are joined together, the groove 513b is covered by the upper surface 53b of the bottom cover 53. This forms a downstream portion of the air flow path 57b (a second portion of the flow path).

[0081] In this embodiment, the groove 513b extends toward the +X side and the +Y side along the lower surface portion 51b (FIG. 7(b)). Note that the extension direction of the groove 513b may be changed as long as it is in the in-plane direction of the lower surface portion 51b, and the groove 513b may be bent one or more times within the plane of the lower surface portion 51b.

[0082] Also, an end (the end on the +X side) of groove portion 513b communicates with air exhaust port 514b through a hole formed in holder body 510 (FIG. 7(c)). Therefore, when holder body 510 and bottom cover 53 are joined, a downstream portion of air flow path 57b communicates with air exhaust port 514b.

[0083] In this way, by providing grooves 511b, 513b on two surfaces (flat surface portion 51f and bottom surface portion 51b) of holder body 510, it is possible to form air flow path 57b with a curved shape that cannot be realized within a single plane.

[0084] Furthermore, the holder body 510 is provided with an internal flow path 512b that communicates with the groove 511b and the groove 513b. The internal flow path 512b is formed in a tunnel shape inside the holder body 510. One end of the internal flow path 512b opens into the groove 511b at a position away from the ridge R1 in the Z-axis direction. The other end of the internal flow path 512b opens into the groove 513b at a position away from the ridge R1 in the X-axis direction.

[0085] In other words, internal flow path 512b is configured to connect the upstream and downstream portions of air flow path 57b via a path that bypasses ridgeline R1 and passes through the inside of holder body 510. The end portion (FIG. 7(c)) of groove 511b that is closer to ridgeline R1 is provided at a position away from ridgeline R1 in the Z-axis direction. The end portion 513b1 (FIG. 7(c)) of groove 513b that is closer to ridgeline R1 is provided at a position away from ridgeline R1 in the X-axis direction. In other words, grooves 511b and 513b are formed so as not to reach ridgeline R1.

[0086] In this embodiment, two air flow paths 57a, 57b are formed by one holder main body 510, one connection member 52a, and one bottom cover 53. This makes it possible to realize a plurality of flow paths for transporting toner by air with a simple configuration.

[0087] In other words, the developing container 3Y (container) is the first container, the cartridge 430Y (supply container) is the first supply container, the air flow path 57a (flow path) is the first flow path, and the internal flow path 512a is the first internal flow path. In this case, the image forming unit 1A has another developing container 3M (second container) for containing toner. The cartridge holder 51 (flow path forming part) forms an air flow path 57b (second flow path) through which air flows to supply toner from a cartridge 430M (second supply container) other than the cartridge 430Y to the developing container 3M (second container). One of the flat surface portion 51f (first surface) and the flat surface portion 52a1 (third surface) is provided with a groove portion 511b (third groove portion) recessed in a direction away from the other of the flat surface portion 51f (first surface) and the flat surface portion 52a1 (third surface) in the first direction. The groove 511b is covered by the holder main body 510 (first member) or the connection member 52a (second member) having the other of the flat surface portion 51f (first surface) and the flat surface portion 52a1 (third surface) to form a part of the air flow path 57b (second flow path). One of the lower surface portion 51b (second surface) and the upper surface portion 53b (fourth surface) is provided with a groove 513b (fourth groove) recessed in a direction away from the other of the lower surface portion 51b (second surface) and the upper surface portion 53b (fourth surface) in the second direction. The groove 513b is covered by the holder main body 510 (first member) or the bottom cover 53 (third member) having the other of the lower surface portion 51b (second surface) and the upper surface portion 53b (fourth surface) to form the other part of the air flow path 57b (second flow path). The holder body 510 (first member) has an internal flow passage 512b (second internal flow passage) formed inside the holder body 510, the internal flow passage 512b opening to the one part and the other part of the air flow passage 57b (second flow passage) at a position away from the ridge line portion R1. This makes it possible to realize a plurality of flow passages with a simple configuration.

[0088] (3. Air supply path to cartridges 430C and 430K) The air supply paths to the cartridges 430C and 430K are basically the same as the air supply paths to the cartridges 430Y and 430M, except that the connecting member 52d is used instead of the connecting member 52d.

[0089] As shown in FIG. 6(a)(b), the air connection ports 523 and 524 are provided on the connection member 52d. The holder body 510 has a flat surface 51h facing the connection member 52d. The connection member 52d has a flat surface 52d1 facing the holder body 510. In this embodiment, the connection member 52d is joined to the holder body 510 by bonding the flat surfaces 51h and 52d1 with an adhesive. The flat surface 51h of the holder body 510 and the flat surface 52d1 of the connection member 52d are substantially parallel surfaces. In this embodiment, the flat surfaces 51h and 52d1 extend in a direction intersecting the X-axis direction. The flat surface 51h of the holder body 510 is a surface facing one side (-X side) in the X-axis direction, and the flat surface 52d1 of the connection member 52d is a surface facing the other side (+X side) in the X-axis direction.

[0090] Grooves 511c and 511d are formed in flat surface portion 51h of holder body 510. When holder body 510 and connection member 52d are joined, grooves 511c and 511d are covered by flat surface portion 52d1 of connection member 52d. This forms upstream portions of air flow paths 57c and 57d (first portions of the flow paths).

[0091] The grooves 511c and 511d in this embodiment extend substantially along the Z-axis direction (FIG. 7(a)). Note that the extension direction of the grooves 511c and 511d may be changed as long as it is within the plane of the flat portion 51h, and the grooves 511c and 511d may be bent one or more times within the plane of the flat portion 51h.

[0092] Furthermore, holes 523a, 524a (FIG. 6(a)) are provided in the flat surface portion 52d1 of the connection member 52d at positions facing the ends (upper ends) of the grooves 511c, 511d. The holes 523a, 524a communicate with the air connection ports 523, 524 via flow paths formed inside the connection member 52d. When the holder body 510 and the connection member 52d are joined, the holes 523a, 524a face the ends of the grooves 511c, 511d. This allows the air connection ports 523, 524 to communicate with the upstream portions of the air flow paths 57c, 57d.

[0093] Grooves 513c, 513d are formed in the lower surface portion 51b of the holder main body 510. When the holder main body 510 and the bottom cover 53 are joined together, the grooves 513c, 513d are covered by the upper surface portion 53b of the bottom cover 53. This forms downstream portions of the air flow paths 57c, 57d (second portions of the flow paths).

[0094] Groove portion 513c in this embodiment extends toward the +X side and the -Y side along lower surface portion 51b (FIG. 7(b)). Groove portion 513d in this embodiment extends toward the +X side and the -Y side along lower surface portion 51b (FIG. 7(b)). Groove portion 513c and groove portion 513d extend in different directions, with groove portion 513d being closer to the Y-axis direction. Note that the extension directions of groove portions 513c and 513d may be changed as long as they are in the in-plane direction of lower surface portion 51b, or groove portions 513c and 513d may be bent one or more times in the plane of lower surface portion 51b.

[0095] Furthermore, the ends (ends on the +X side) of the grooves 513c and 513d communicate with the air exhaust port 514b through holes formed in the holder body 510 (FIG. 7(c)). Therefore, when the holder body 510 and the bottom cover 53 are joined, the downstream parts of the air flow paths 57c and 57d communicate with the air exhaust port 514b.

[0096] In this way, by providing groove portions 511c, 511d, 513c, and 513d on two surfaces (flat surface portion 51h and bottom surface portion 51b) of the holder body 510, it is possible to form air flow paths 57c, 57d with curved shapes that cannot be realized within a single plane.

[0097] Furthermore, the holder body 510 is provided with internal flow paths 512c and 512d that communicate the grooves 511c and 511d with the grooves 513c and 513d. The internal flow paths 512c and 512d are formed in a tunnel shape inside the holder body 510. One end of the internal flow paths 512c and 512d opens into the grooves 511c and 511d at a position away from the ridgeline R2 in the Z-axis direction. The other end of the internal flow paths 512c and 512d opens into the grooves 513c and 513d at a position away from the ridgeline R2 in the X-axis direction.

[0098] In other words, the internal flow paths 512c, 512d are configured to connect the upstream and downstream parts of the air flow paths 57c, 57d via a path that bypasses the ridgeline R2 and passes through the inside of the holder main body 510. The ends of the grooves 511c, 511d that are closer to the ridgeline R2 (FIG. 7(c)) are provided at a position away from the ridgeline R2 in the Z-axis direction. The ends of the grooves 513c, 513d that are closer to the ridgeline R2 (FIG. 7(c)) are provided at a position away from the ridgeline R2 in the X-axis direction. In other words, the grooves 511c, 511d, 513c, 513d are all formed so as not to reach the ridgeline R2.

[0099] In this embodiment, the internal flow paths 512c, 512d are formed in an approximately L-shape including a portion extending in approximately the +X direction from the end portion closer to the ridge portion R2 of the groove portions 511c, 511d, and a portion extending in approximately the +Z direction from the end portion closer to the ridge portion R2 of the groove portions 513c, 513d.

[0100] Furthermore, in this embodiment, two air flow paths 57c, 57d are formed by one holder body 510, one connection member 52d, and one bottom cover 53. This makes it possible to realize a plurality of flow paths for transporting toner by air with a simple configuration.

[0101] (4. Summary of air supply paths) The air flow paths 57a, 57b, 57c, and 57d described above can realize paths for supplying air from the pump unit 80 to each cartridge 430 in a small space. Also, as shown in Figures 7(a) and (b), the positions of the air exhaust ports 514a, 514b, 514c, and 514d corresponding to the air connection ports 521, 522, 523, and 524 can be easily moved in any of the three axial directions of X, Y, and Z. In other words, by forming flow paths that are bent along multiple faces of the holder body 510, the degree of freedom in designing the flow paths can be improved.

[0102] The advantages of this embodiment will be described below by taking the air flow path 57a corresponding to the cartridge 430Y as an example.

[0103] In this embodiment, by providing groove portion 511a (first groove portion) and groove portion 513a (second groove portion) on two surfaces (flat surface portion 51f and bottom surface portion 51b) of the holder main body 510, it is possible to form an air flow path 57a with a curved shape that cannot be realized within a single plane.

[0104] Instead of providing the air flow path 57a in the cartridge holder 51, it is possible to arrange the air connection port 521 near the air discharge port 514a and extend the air supply pipe 61 to the vicinity of the air discharge port 514a and connect it to the air connection port 521. However, if the air supply pipe 61 is extended to the vicinity of the air discharge port 514a, the space required for arranging the air supply pipe 61 may become large. Specifically, in order to suppress air leakage, it is required that the press-fit length of the air supply pipe 61 into the air connection port 521 (the protrusion amount of the air connection port 521) is relatively long. Also, when the air supply pipe 61 is curved according to the positional relationship between the air connection port 521 and the pump unit 80, it is required to increase the radius of curvature to a certain degree so that the air supply pipe 61 does not buckle. For this reason, if there is a space restriction near the air discharge port 514a, it may be difficult to extend the air supply pipe 61 to the vicinity of the air discharge port 514a.

[0105] As yet another alternative configuration, instead of providing the air flow path 57a in the cartridge holder 51, it is also possible to connect the air supply pipe 61 to an L-shaped tube (bent tube). However, if the L-shaped tube is press-fitted into the inside of the air supply pipe 61 to ensure airtightness, there are disadvantages such as a smaller inner diameter of the L-shaped tube, narrowing the flow path, and increasing the pressure loss of the air.

[0106] According to this embodiment, even if the space around the air exhaust port 514a is narrow, the air connection port 521 can be provided at a position away from the air exhaust port 514a, and the air connection port 521 and the air exhaust port 514a can be connected by the air flow path 57a inside the cartridge holder 51. The air flow path 57a can be realized in a small space because it is configured such that the grooves 511a, 513a provided in the holder main body 510 are covered and sealed with the connection member 52a and the bottom cover 53. Also, the air flow path 57a can be bent at a steep angle, which is difficult to achieve by bending the air supply pipe 61.

[0107] More specifically, in this embodiment, the cartridge 430Y (supply container) is configured to be mounted on the holder body 510 (first member). The cartridge 430Y is mounted on the upstream side of the holder body 510 in the mounting direction (approximately the -X direction) relative to the holder body 510. Meanwhile, the pump unit 80 (air supply unit) is disposed on the downstream side of the holder body 510 in the mounting direction. Then, the air discharge port 514a (second opening) connected to the cartridge 430Y is located upstream of the air connection port 521 (first opening) connected to the pump unit 80 in the mounting direction. This allows the distance between the pump unit 80 and the air connection port 521 to be shortened in the mounting direction, and the distance between the air discharge port 514a and the cartridge 430Y to be shortened. Then, the air connection port 521 (first opening) and the air discharge port 514a (second opening), which are disposed apart in the mounting direction, can be connected by the air flow path 57a, which has a high degree of design freedom.

[0108] In this embodiment, the pump unit 80 is disposed above the developing container 3Y (container). The position of the cartridge 430Y (supply container) in the vertical direction (Z-axis direction) overlaps with the position of the developing container 3Y in the vertical direction. The receiving port 430Yb1 (opening) of the cartridge 430Y is disposed below the pump unit 80. The air discharge port 514a (second opening) connected to the cartridge 430Y is located below the air connection port 521 (first opening) connected to the pump unit 80. This allows the distance between the pump unit 80 and the air connection port 521 to be shortened in the vertical direction, and the distance between the air discharge port 514a and the cartridge 430Y to be shortened. The air connection port 521 (first opening) and the air discharge port 514a (second opening), which are disposed apart in the vertical direction, can be connected by the air flow path 57a, which has a high degree of design freedom.

[0109] In addition, in this embodiment, the direction in which the air exhaust port 514a (second opening) connected to the cartridge 430Y is open (approximately +Z direction) is different from the direction in which the air connection port 521 (first opening) connected to the air supply pipe 61Y (cylindrical member) is open (approximately -X direction). For this reason, it is difficult to realize a path that is sharply bent like the air flow path 57a of this embodiment by bending the flexible air supply pipe 61Y. In contrast, according to this embodiment, the air connection port 521 (first opening) and the air exhaust port 514a (second opening), which have different opening directions, can be connected by the air flow path 57a, which has a high degree of design freedom.

[0110] In this embodiment, the grooves 511a, 513a provided on the two surfaces (flat surface portion 51f and bottom surface portion 51b) of the holder body 510 are connected by an internal flow path 512a formed inside the holder body 510. The internal flow path 512a opens to the upstream portion 57a1 and downstream portion 57a2 of the air flow path 57a at positions away from the ridges R1 of the two surfaces. This reduces the possibility of air leaking from a gap occurring at the ridges R1.

[0111] If the grooves 511a and 513a were directly connected at the ridgeline R1, the flat surface 51f and the lower surface 51b of the holder body 510, the flat surface 52a1 of the connection member 52a, and the upper surface 53b of the bottom cover 53 would be concentrated at the ridgeline R1. At this time, a gap may be generated between the flat surface 52a1 of the connection member 52a and the upper surface 53b of the bottom cover 53. That is, when the lower surface 51b of the holder body 510 is brought into close contact with the upper surface 53b of the bottom cover 53, a gap may be generated between the flat surface 52a1 of the connection member 52a and the upper surface 53b of the bottom cover 53 due to dimensional errors during component manufacturing, positioning errors during joining, and the like. If such a gap is present, air may leak from the air flow path 57a to the outside of the cartridge holder 51. In order to prevent gaps from occurring near the ridgeline R1, it is possible to improve the accuracy of dimensional errors of the parts and position adjustment during joining, but this could increase manufacturing costs and man-hours.

[0112] In contrast, in this embodiment, the grooves 511a and 513a do not reach the ridgeline R1, and the grooves 511a and 513a are connected by an internal flow path 512a inside the holder body 510. Therefore, even if there is a gap between the flat surface 52a1 of the connection member 52a and the upper surface 53b of the bottom cover 53 at a position adjacent to the ridgeline R1, air does not leak through this gap. If there is airtightness between the flat surface 51f of the holder body 510 and the flat surface 52a1 of the connection member 52a, and between the lower surface 51b of the holder body 510 and the upper surface 53b of the bottom cover 53, air leakage to the outside of the cartridge holder 51 can be suppressed.

[0113] In this embodiment, a gap G1 (FIG. 7(c)) may be present between the connection member 52a (second member) and the bottom cover 53 (third member) at a position adjacent to the ridge line portion R1. This reduces the possibility that the upper surface portion 53b of the bottom cover 53 cannot abut against the lower surface portion 51b of the holder body 510 due to abutment between the bottom cover 53 and the connection member 52a, for example.

[0114] [Air supply from air outlet to cartridge] A description will be given of the supply of air from the air exhaust ports 514a, 514b, 514c, and 514d to each cartridge 430. Hereinafter, any one of the air exhaust ports 514a, 514b, 514c, and 514d will be referred to as an air exhaust port 514. As shown in Figures 3(b) and 5(a), each air exhaust port 514 opens upward (approximately in the +Z direction).

[0115] 3(a) and 5(a), each cartridge 430 has receiving openings 430Yb1, 430Mb1, 430Cb1, 430Kb1 connected to the corresponding air exhaust port 514. When each cartridge 430 is attached to the cartridge holder 51, each of the receiving openings 430Yb1, 430Mb1, 430Cb1, 430Kb1 is connected to the corresponding air exhaust port 514.

[0116] Air discharged upward from each air outlet 514 passes through the corresponding inlets 430Yb1, 430Mb1, 430Cb1, and 430Kb1 and is supplied to the inside of the cartridge 430. The air supplied to the inside of each cartridge 430 is discharged to the outside together with toner from each cartridge 430. The internal structure of the cartridge 430 will be described later.

[0117] The toner discharged together with air from each cartridge 430 enters a toner flow path from toner receiving ports 515a, 515b, 515c, and 515d (FIGS. 3(a) and 6(a)) of the cartridge holder 51. The toner is then discharged together with air from toner connection ports 525, 526, 527, and 528 (FIGS. 4(b) and 6(b)), which are the outlets of the toner flow path.

[0118] Toner connection ports 525, 526, 527, 528 are connected to one ends (upstream ends 62Yu, 62Mu, 62Cu, 62Ku) of supply pipes 62Y, 62M, 62C, 62K (FIGS. 3(b), 4(b)). Supply pipes 62Y, 62M, 62C, 62K are flexible cylindrical members (tubes). Hereinafter, any one of supply pipes 62Y, 62M, 62C, 62K will be referred to as supply pipe 62.

[0119] The toner receiving openings 515a, 515b, 515c, and 515d (FIG. 6(a)) of the cartridge holder 51 are through holes provided in the front part of the holder main body 510. The front part of the holder main body 510 is the surface facing the rear surface (-X side surface) of each cartridge 430. The toner receiving openings 515a, 515b, 515c, and 515d open toward the X-axis direction in which the developing units 9Y, 9M, 9C, and 9K are aligned. The opening direction of the toner receiving openings 515a, 515b, 515c, and 515d intersects with the opening direction of the air exhaust ports 514a, 514b, 514c, and 514d.

[0120] As shown in FIG. 6(b), toner connection ports 525, 526, 527, and 528 are provided in connection members 52a, 52b, 52c, and 52d provided on the rear surface of cartridge holder 51. Toner connection port 525 communicates with toner receiving port 515a via a flow path inside connection member 52a and a flow path formed between a groove portion provided in flat surface portion 51f of holder main body 510 and flat surface portion 52a1 of connection member 52a. Toner connection port 526 communicates with toner receiving port 515b via a flow path inside connection member 52b. Toner connection port 527 communicates with toner receiving port 515c via a flow path inside connection member 52c. The toner connection port 528 is connected to the toner receiving port 515d via a flow path inside the connection member 52d and a flow path formed between a groove portion provided in the flat portion 51h of the holder main body 510 and the flat portion 52d1 of the connection member 52d.

[0121] As shown in Fig. 7(a), of the toner connection ports 525, 526, 527, and 528, the toner connection ports 526 and 527 located at the center in the Y-axis direction face outward in the Y-axis direction and upward in the Z-axis direction. This makes it easy to extend the supply pipes 62M and 62C connected to the toner connection ports 526 and 527 toward the end positions of the process unit PK in the Y-axis direction, passing above the toner connection ports 525 and 528 (Fig. 4(b)). Note that by extending the supply pipes 62Y, 62M, 62C, and 62K in the X-axis direction through the end positions of the process unit PK in the Y-axis direction, the supply pipes 62Y, 62M, 62C, and 62K can be prevented from blocking the optical path LK (Fig. 1) of the laser light.

[0122] The other ends (downstream ends) of the supply pipes 62Y, 62M, 62C, and 62K are connected to the developing units 9Y, 9M, 9C, and 9K, respectively. The toner discharged from the toner connection ports 525, 526, 527, and 528 is carried by the air current through the supply pipes 62Y, 62M, 62C, and 62K, respectively, to the developing units 9Y, 9M, 9C, and 9K. Then, the toner is supplied to each developing unit 9.

[0123] A toner receiving port is provided on the upper surface of the developing container 3, which is a toner storage section in each developing unit 9, and is connected to a corresponding supply pipe 62. Air (air mixture) containing toner is supplied to the developing container 3 through the toner receiving port.

[0124] It is preferable that the image forming unit 50 is configured to have easy access to the process unit P and the supply pipe 62 for maintenance and replacement of the process unit P and the supply pipe 62 during service response in the event of a breakdown, etc. Therefore, the image forming unit 50 in this embodiment is configured so that it can be pulled out from the back side (BE) to the front side (FE) with respect to the apparatus main body 72 (intermediate transfer belt unit 11).

[0125] [Cartridge structure] The structure of each cartridge 430 (toner container, supply container) of this embodiment will be described with reference to FIGS. 8(a) to 10(b).

[0126] The cartridges 430Y, 430M, 430C, and 430K have basically the same structure, so the following will describe the cartridge 430Y. Figures 8(a), (b), (c), (d), and (e) are a front view, a top view, a bottom view, a right side view, and a rear view of the cartridge 430Y, respectively. Figure 9(a) is a cross-sectional view of the cartridge 430Y taken along line HH in Figure 8(e). Figure 9(b) is a cross-sectional perspective view of the cartridge 430Y. Figure 9(c) is an exploded perspective view of the cartridge 430Y in Figure 9(b). Figure 10(a) is a cross-sectional view of the cartridge 430Y taken along line GG in Figure 8(b). Figure 10(b) is a perspective view of Figure 10(a). The following description of the structure of the cartridge 430Y is based on the state (posture) in which the cartridge 430Y is attached to the cartridge holder 51.

[0127] As shown in FIGS. 9(a) to 9(c), the cartridge 430Y has 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). Although not shown, the cartridge 430M also has a first frame, a second frame, a filter (second filter, second ventilation member), and a discharge pipe (second discharge pipe, second passage). The cartridge also has a first frame, a second frame, a filter (third filter, third ventilation member), and a discharge pipe (third discharge pipe, third passage). The cartridge 430K also has a first frame, a second frame, a filter (fourth filter, fourth ventilation member), and a discharge pipe (fourth discharge pipe, fourth passage).

[0128] In this embodiment, the first frame 430Ya and the second frame 430Yb are members molded from resin, but may be made from paper or the like. As shown in FIG. 8(e), a discharge port 430Ya1 (first discharge port) is provided on the back surface 4300Ya of the first frame 430Ya. As shown in FIG. 8(c), a receiving port 430Yb1 (first receiving port, first intake port) is provided on the bottom surface 4300Yb of the second frame 430Yb. It is preferable to provide the discharge port 430Ya1 and the receiving port 430Yb1 on the surface of the cartridge 430Y except for the surface (surface facing the Y-axis direction) that intersects with the Y-axis direction in which the cartridges 430Y, 430M, 430C, and 430K are aligned. This makes it possible to reduce the gaps G (Gym, Gmc, Gck) between cartridges 430Y, 430M, 430C, and 430K shown in FIG. 3(a). As a result, the width of each cartridge 430 can be increased, and the volume for storing toner can be increased. Note that gap Gym is the gap between cartridge 430Y and cartridge 430M in the Y-axis direction. Gap Gmc is the gap between cartridge 430M and cartridge 430C in the Y-axis direction. Gap Gck is the gap between cartridge 430C and cartridge 430K in the Y-axis direction.

[0129] The ejection port 430Ya1 is provided on the rear surface 4300Ya (the end surface on the downstream side in the mounting direction of the cartridge 430Y) of the cartridge 430Y so as to open toward the downstream side in the mounting direction. The mounting direction in this embodiment is the direction from the front side to the rear side of the image forming apparatus 1 (-X direction). Therefore, when the cartridge 430Y is mounted in the cartridge holder 51, the ejection port 430Ya1 can be easily engaged so as to communicate with the receiving port 429Ya of the cartridge holder 51. The ejection port 430Ya1 may be provided on the bottom surface 4300Yb or the top surface of the cartridge 430Y, and the receiving port 430Yb1 may be provided on the rear surface 4300Ya or the top surface.

[0130] In cases where there is sufficient space in the device main body 72, the discharge port 430Ya1 and the receiving port 430Yb1 may be provided on a plane intersecting with the Y-axis direction. Cartridge 430M has a discharge port and a receiving port 430Mb1 (inlet, FIG. 3(a)) in the same arrangement as cartridge 430Y. Cartridge 430C has a discharge port and a receiving port 430Cb1 (inlet, FIG. 3(a)) in the same arrangement as cartridge 430Y. Cartridge 430K has a discharge port and a receiving port 430Kb1 (inlet, FIG. 3(a)) in the same arrangement as cartridge 430Y.

[0131] The discharge port 430Ya1 may be provided with a sealing member (seal or shutter) (not shown). When the cartridge 430Y is not attached to the cartridge holder 51 of the apparatus main body 72, the sealing member seals the discharge port 430Ya1 to prevent the toner T contained therein from leaking out of the cartridge 430Y. When the cartridge 430Y is attached to the cartridge holder 51, the sealing member is removed or moved so that the discharge port 430Ya1 is opened.

[0132] 8(a) is for indicating the color of the toner inside. The label 430Ys may also indicate instructions showing how to mount the cartridge 430Y in the cartridge holder 51, or may indicate some other information related to the cartridge 430Y.

[0133] The first frame 430Ya and the second frame 430Yb have a flange portion 430Ya2 and a flange portion 430Yb2, respectively. The flange portion 430Ya2 and the flange portion 430Yb2 are joined to each other by ultrasonic welding or the like to form an internal space SPY of the cartridge 430Y shown in Fig. 9(a). The flange portion 430Ya2 and the flange portion 430Yb2 may be joined with an adhesive or screws.

[0134] The filter 83Y is provided so as to partition (divide) the internal space SPY of the cartridge 430Y into two, a toner chamber 430Yc (first chamber) and an air chamber 430Yd (second chamber). In other words, the air chamber 430Yd is adjacent to the toner chamber 430Yc via the filter 83Y. In the other cartridges 430M, 430C, and 430K, the internal space of the cartridge is also partitioned (divided) into a toner chamber and an air chamber by a filter. These air chambers are adjacent to the toner chambers via the filters, respectively.

[0135] The toner chamber 430Yc is located above the air chamber 430Yd and is aligned with the air chamber 430Yd in the Z-axis direction. In other words, the cartridge 430Y is mounted in the apparatus main body 72 in a position in which the toner chamber 430Yc is above the air chamber 430Yd. The alignment direction of the toner chamber 430Yc and the air chamber 430Yd is the Z-axis direction. Therefore, in this embodiment, the receiving opening 430Yb1 opens toward this alignment direction, and the discharge opening 430Ya1 opens in a direction intersecting this alignment direction.

[0136] The toner chamber 430Yc (accommodating space) is configured to accommodate the toner T. In the toner chamber 430Yc, the toner T is supported by the filter 83Y.

[0137] No toner is stored in the air chamber 430Yd. The filter 83Y is made of a porous member made of, for example, resin fibers, and has a pore size and density that allows air to pass through and prevents toner from passing through. In other words, the filter 83Y is configured to allow air to pass through and prevent toner from passing through. As shown in Figs. 9(a) to 10(b), the filter 83Y is held by the first frame 430Ya and the second frame 430Yb by having the outer edge 83Ya sandwiched between the flange 430Ya2 of the first frame 430Ya and the flange 430Yb2 of the second frame Yb. The filter 83Y is inclined from the outer edge 83Ya toward the lowest part 83Yb, which is located below the outer edge 83Ya. In other words, the filter 83Y has a portion (inclined portion) that is inclined downward as it approaches (closes to) the lowest part 83Yb in the X-axis direction, Y-axis direction, or horizontal direction.

[0138] The bottom portion 83Yb is a portion that protrudes from the outer edge portion 83Ya in the direction from the toner chamber 430Yc toward the air chamber 430Yd. The bottom portion 83Yb is provided at the center of the filter 83Y in the X-axis direction and the Y-axis direction, as shown in Figures 9(a) and 10(b). The filter 83Y is a pyramid preformed with the bottom portion 83Yb as the apex.

[0139] The toner chamber 430Yc is provided with a discharge pipe 85Y (passage). Although the discharge pipe 85Y in this embodiment is a member molded with resin, it may be formed of paper, rubber, or the like. The discharge pipe 85Y is a pipe having an inlet 85Ya (first opening) and an outlet 85Yb (second opening) and extending from the inlet 85Ya to the outlet 85Yb. The discharge pipe 85Y is a passage through which the toner T accommodated in the toner chamber 430Yc passes when it is moved toward the discharge port 430Ya1. The discharge pipe 85Y has a first portion 85Y1 having the inlet 85Ya and extending in the Z-axis direction, and a second portion 85Y2 having the outlet 85Yb and extending in the X-axis direction. The direction in which the first portion 85Y1 extends and the direction in which the second portion 85Y2 extends intersect (perpendicular to each other in this embodiment).

[0140] The outlet 85Yb of the discharge pipe 85Y is connected to communicate with the discharge port 430Ya1. The inlet 85Ya of the discharge pipe 85Y is arranged to face the lowest part 83Yb, which is a part of the filter 83Y, with a gap therebetween. It is preferable that the inlet 85Ya is close to the filter 83Y. When the remaining amount of toner T in the toner chamber 430Yc becomes small, the toner T fluidized by the air received from the receiving port 430Yb1 moves along the inclination of the filter 83Y described above and collects at the lowest part 83Yb. The toner T collected at the lowest part 83Yb of the filter 83Y enters the inlet 85Ya of the discharge pipe 85Y and is guided through the discharge pipe 85Y to the discharge port 430Ya1. As a result, even when the remaining amount of toner contained in the toner chamber 430Yc of the cartridge 430Y becomes small, the toner T can be efficiently discharged to the outside of the cartridge 430Y.

[0141] The cartridge 430Y of this embodiment has a structure in which toner is discharged to the outside of the cartridge by air, and is not provided with a rotating member such as a screw, etc. Therefore, it is possible to make the cartridge have a simple structure with a small number of parts.

[0142] [Toner transport mechanism] The mechanism by which the toner contained in the toner chamber 430Yc of the cartridge 430Y is transported to the developing unit 9Y will be described.

[0143] Air discharged from the pump of the pump unit 80 corresponding to the cartridge 430Y passes through the air supply pipe 61Y and the air flow path 57a of the cartridge holder 51, and is discharged from the air discharge port 514a (FIG. 5(b)) facing the cartridge 430Y. The air discharged from the air discharge port 514a is received into the air chamber 430Yd through the receiving port 430Yb1 of the cartridge 430Y. Then, the air pressure in the air chamber 430Yd (FIG. 9(d)) increases, and the air passes through the filter 83Y and flows from the air chamber 430Yd into the toner chamber 430Yc. The air that flows into the toner chamber 430Yc enters between the particles of the toner T, fluidizing the toner T. The toner T, which is mixed with air and fluidized, is moved through the discharge pipe 85Y from the inlet 85Ya to the outlet 85Yb by the air received in the air chamber 430Yd through the receiving port 430Yb1, and is discharged to the outside of the cartridge 430Y through the discharge port 430Ya1.

[0144] By providing the air chamber 430Yd, which is a highly sealed space, between the discharge port of the pump unit 80 and the filter 83Y, the air discharged from the discharge port efficiently travels to the filter 83Y without dispersing outside the cartridge 430Y. For example, in a situation 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 for a long time, the pressure required to pass through the filter 83Y and flow into the cartridge 430Y may increase. Even in this case, air can be passed through the filter 83Y and sent into the toner chamber 430Yc by continuing to send air from the pump unit 80 to the air chamber 430Yd and increasing the pressure (atmospheric pressure) in the air chamber 430Yd. In addition, by providing the air chamber 430Yd, the toner can be discharged from the cartridge 430Y with a relatively small amount of air supplied by the pump unit 80. In other words, the pump unit 80 is sufficient if it can generate a pressure sufficient to continuously send air into the air chamber 430Yd to a pressure sufficient to pass air through the filter 83Y into the toner chamber 430Yc, and no special requirements are imposed on the discharge speed or discharge amount. This makes it possible to employ a small pump unit 80, which contributes to the miniaturization of the device.

[0145] 4B, the toner T discharged from the discharge port 430Ya1 of the cartridge 430Y passes through the toner receiving port 515a of the cartridge holder 51 and enters the inside of the supply pipe 62Y from the upstream end 62Yu of the supply pipe 62Y. The toner T that has entered the inside of the supply pipe 62Y from the upstream end 62Yu is moved to the downstream end of the supply pipe 62Y by air that flows into the supply pipe 62Y together with the toner T.

[0146] In order to improve the discharge of air, the developing unit 9Y is provided with an exhaust filter part PYf on the upper surface of the developing unit 9Y as shown in FIG. 3. The exhaust filter part PYf is a part in which a through hole is provided in a frame body forming the developing unit 9Y and a filter such as a nonwoven fabric is attached so as to cover the through hole. The toner T that flows into the inside of the developing unit 9Y from the supply pipe 62Y remains inside the developing unit 9Y, and at least a part of the air is discharged to the outside of the developing unit 9Y from the exhaust filter part PYf. This suppresses an increase in the internal pressure inside the developing unit 9Y, and the toner T and air can easily flow into the developing unit 9Y from the cartridge 430Y through the supply pipe 62Y. The other developing units 9M, 9C, and 9K are also provided with similar exhaust filter parts PMf, PCf, and PKf.

[0147] In this embodiment, the exhaust filter part PYf is provided on the upper surface of the developing unit 9Y in a downstream portion in the toner inflow direction (+Y direction) in the Y-axis direction. The exhaust filter part PYf may be provided on the side surface of the developing unit 9Y instead of on the upper surface.

[0148] The toner supplied to the developing unit 9Y (developing container 3Y) is stirred and leveled by the stirring members SY1 and SY2 shown in FIG. 5(b). When the downstream end of the supply pipe 62Y is connected to one end of the developing unit 9Y in the Y-axis direction, the stirring members SY1 and SY2 may be screws that transport the toner in the Y-axis direction from one end to the other end of the developing unit 9Y (+Y direction). Depending on the required stirring efficiency of the toner T in the developing unit 9Y, the stirring members may be one or three or more. The other developing units 9M, 9C, and 9K are also provided with similar stirring members SM1, SM2, SC1, SC2, SK1, and SK2.

[0149] In the case of a configuration in which the direction of the transport path changes midway or the transport path differs for each color, such as the supply pipe 62 in this embodiment, it is preferable to use air as a transport means for transporting toner. This allows for greater freedom in designing the transport path than using a screw or other transport means, and reduces the number of parts because no transport member is required.

[0150] In each process unit P, the developing unit 9 may be configured to be movable within the apparatus body, for example, to be swingable relative to the drum unit 8 or to be pressed against the drum unit 8. In this case, it is preferable that each supply pipe 62 is formed from a stretchable and flexible material. This makes it possible to prevent each supply pipe 62 from interfering with the operation of the corresponding developing unit 9, and to prevent the addition of parts to accommodate the operation of the corresponding developing unit 9.

[0151] Example 2 A cartridge holder 51 (flow path forming portion) according to the second embodiment will be described with reference to Fig. 11. In the following, elements with the same reference symbols as those in the first embodiment have basically the same configurations and functions as those described in the first embodiment unless otherwise specified, and differences from the first embodiment will be mainly described.

[0152] FIG. 11 is a cross-sectional view of a cartridge holder 51 according to Example 2, and corresponds to FIG. 7(c) of Example 1. Example 2 differs from Example 1 in that a groove 529 serving as a first groove is provided on a flat surface portion 52a1 (third surface of the second member) of a connection member 52a. Example 2 also differs from Example 1 in that a groove 531a serving as a second groove is provided on an upper surface portion 53b (fourth surface of the third member) of a bottom cover 53. Other configurations of the cartridge holder 51 are basically the same as those of Example 1.

[0153] When the holder body 510 and the connection member 52a are joined, the groove 529 is covered by the flat surface 51f (first surface) of the holder body 510. This forms an upstream portion 57a1 (first portion of the flow path) of the air flow path 57a. When the holder body 510 and the bottom cover 53 are joined, the groove 531a is covered by the lower surface 51b of the holder body 510. This forms a downstream portion 57a2 (second portion of the flow path) of the air flow path 57a.

[0154] In this manner, by providing grooves 529, 531a on the surfaces (flat surface portion 52a1 and upper surface portion 53b) of another member facing the two surfaces of holder body 510, it is possible to form air flow path 57a having a curved shape that cannot be realized within one plane. In other words, according to embodiment 2, it is possible to improve the degree of freedom in designing the flow path, similarly to embodiment 1.

[0155] Furthermore, the holder main body 510 is provided with an internal flow path 512a that communicates with the groove portion 529 and the groove portion 531a. The internal flow path 512a is formed inside the holder main body 510. One end of the internal flow path 512a opens into a region of the flat surface portion 51f facing the groove portion 529 at a position away from the ridge portion R1 in the Z axis direction. The other end of the internal flow path 512a opens into a region of the lower surface portion 51b facing the groove portion 531a at a position away from the ridge portion R1 in the X axis direction.

[0156] In other words, the upstream portion 57a1 (first portion of the flow path) and the downstream portion 57a2 (second portion of the flow path) of the air flow path 57a are connected by an internal flow path 512a formed inside the holder body 510. The internal flow path 512a opens to the upstream portion 57a1 and the downstream portion 57a2 of the air flow path 57a at positions away from the ridge portions R1 of the two faces. This reduces the possibility of air leaking from a gap occurring at the ridge portion R1, as in the first embodiment.

[0157] Example 3 A cartridge holder 51 (flow path forming portion) according to Example 3 will be described with reference to Fig. 12. In the following, elements having the same reference symbols as those in Example 1 will have basically the same configurations and functions as those described in Example 1 unless otherwise specified, and differences from Example 1 will be mainly described.

[0158] Fig. 12 is a cross-sectional view of a cartridge holder 51 according to Example 3, and corresponds to Fig. 7(c) of Example 1. Example 3 differs from Example 1 in that, in addition to groove 511a as the first groove, groove 529 as the third groove forming part of air flow path 57a together with groove 511a is provided on flat surface 52a1 (third surface of the second member) of connection member 52a. Also, Example 2 differs from Example 1 in that, in addition to groove 513a as the second groove, groove 531a as the fourth groove forming part of air flow path 57a together with groove 513a is provided on upper surface 53b (fourth surface of the third member) of bottom cover 53.

[0159] When the holder body 510 and the connection member 52a are joined, the groove 511a and the groove 529 face each other. This forms an upstream portion 57a1 of the air flow path 57a (a first portion of the flow path). When the holder body 510 and the bottom cover 53 are joined, the groove 513a and the groove 531a face each other. This forms a downstream portion 57a2 of the air flow path 57a (a second portion of the flow path).

[0160] In this manner, by providing grooves 511a, 513a, 529, and 531a on two surfaces of holder body 510 and on the opposing surface of another member, it is possible to form air flow path 57a having a curved shape that cannot be realized within a single plane. In other words, according to the third embodiment, it is possible to improve the design freedom of the flow path, similarly to the first embodiment.

[0161] Furthermore, the holder body 510 is provided with an internal flow path 512a that connects the groove 511a and the groove 513a. The internal flow path 512a is formed inside the holder body 510. One end of the internal flow path 512a opens into the groove 511a at a position away from the ridge R1 in the Z-axis direction. The other end of the internal flow path 512a opens into the groove 513a at a position away from the ridge R1 in the X-axis direction.

[0162] In other words, the upstream portion 57a1 (first portion of the flow path) and the downstream portion 57a2 (second portion of the flow path) of the air flow path 57a are connected by an internal flow path 512a formed inside the holder body 510. The internal flow path 512a opens to the upstream portion 57a1 and the downstream portion 57a2 of the air flow path 57a at positions away from the ridge portions R1 of the two faces. This reduces the possibility of air leaking from a gap occurring at the ridge portion R1, as in the first embodiment.

[0163] In this embodiment, upstream portion 57a1 of air flow path 57a is formed by two grooves 511a and 529 facing each other, so the cross-sectional area of ​​the flow path can be made larger and pressure loss can be reduced compared to embodiments 1 and 2. Also, in this embodiment, downstream portion 57a2 of air flow path 57a is formed by two grooves 513a and 531a facing each other, so the cross-sectional area of ​​the flow path can be made larger and pressure loss can be reduced compared to embodiments 1 and 2. Therefore, toner can be replenished using air even when a smaller air pump is used, and the device can be made more compact.

[0164] Other Embodiments In the above-described embodiment, an example was described in which the gap between the flat surface portion 51f and the flat surface portions 52a1 and 52d1 is sealed by bonding the cartridge holder 51 and the connecting members 52a and 52d. In the present embodiment, an example was described in which the gap between the lower surface portion 51b and the upper surface portion 53b is sealed by bonding the cartridge holder 51 and the bottom cover 53. The present embodiment is not limited to this, and may be configured such that the gap is sealed by abutting the cartridge holder 51 and the connecting members 52a and 52d with a seal member (first seal member) sandwiched between the flat surface portion 51f and the flat surface portions 52a1 and 52d1. In addition, the present embodiment may be configured such that the gap is sealed by abutting the cartridge holder 51 and the bottom cover 53 with a seal member (second seal member) sandwiched between the lower surface portion 51b and the upper surface portion 53b. In this case, the joining method is not limited to adhesion, and may be any method that can join the members together while the seal member is compressed, such as screw fastening or snap fitting.

[0165] The sealing member is a perforated sheet-like or ring-like member made of an elastic material such as rubber. As a specific example, one sealing member is arranged so as to surround each of the grooves 511a and 511b over the entire circumference when viewed in the X-axis direction. Another sealing member is arranged so as to surround each of the grooves 511c and 511c over the entire circumference when viewed in the X-axis direction. Another sealing member is arranged so as to surround each of the grooves 513a, 513b, 513c, and 513d over the entire circumference when viewed in the Z-axis direction.

[0166] In the above-described embodiments, the configuration of the flow path through which air flows mainly from the pump unit 80 toward the cartridge 430 has been described. However, the present invention is not limited to this, and the configuration of the flow path described in each embodiment may be applied to a flow path through which air containing toner flows from the cartridge 430 toward the developing container 3.

[0167] Summary of the Disclosure The present disclosure includes at least the following: (Configuration 1) An image forming apparatus, an air supply unit that supplies air for transporting the toner; a flow path forming portion formed so that the air supplied by the air supply portion flows through a first flow path, a second flow path, and a third flow path in this order; Equipped with the flow path forming portion includes a first member having a first surface and a second surface intersecting each other with a ridge portion therebetween, a second member having a third surface, and a third member having a fourth surface; The first flow path is formed in a gap between the first surface and the third surface, The third flow path is formed in a gap between the second surface and the third surface, At least a portion of the second flow path is formed in a tunnel shape inside the first member, a first connection portion connecting the first flow path and the second flow path, and a second connection portion connecting the second flow path and the third flow path are provided at a position away from the ridge line portion. 1. An image forming apparatus comprising: (Configuration 2) the first member has a first groove portion provided on the first surface, The first groove portion is covered by the third surface of the second member, thereby forming the first flow path. 2. The image forming apparatus according to claim 1, (Configuration 3) the first member has a second groove portion provided in the second surface, The second groove portion is covered by the fourth surface of the third member, thereby forming the third flow path. 3. The image forming apparatus according to claim 1, wherein the first and second components are arranged in a same plane. (Configuration 4) the second member has a first groove portion provided in the third surface, The first groove portion is covered with the first surface of the first member, thereby forming the first flow path. 2. The image forming apparatus according to claim 1, (Configuration 5) the third member has a second groove portion provided in the fourth surface, The second groove portion is covered with the second surface of the first member, thereby forming the third flow path. 5. The image forming apparatus according to claim 1, wherein the first and second electrodes are arranged in a first direction and a second direction. (Configuration 6) the first member has a first groove portion provided on the first surface, the second member has a third groove portion provided in the third surface, The first groove portion and the third groove portion face each other to form the first flow path. 2. The image forming apparatus according to claim 1, (Configuration 7) the first member has a second groove portion provided in the second surface, the third member has a fourth groove portion provided in the fourth surface, The second groove portion and the fourth groove portion face each other to form the third flow path. 7. The image forming apparatus according to claim 1 or 6, (Configuration 8) the first flow path and the ridge portion are separated by a region where the first surface and the third surface are in contact with each other, The third flow path and the ridge portion are separated by a region where the second surface and the fourth surface are in contact with each other. 8. The image forming apparatus according to any one of configurations 1 to 7. (Configuration 9) There is a gap between the second member and the third member at a position adjacent to the ridge line portion. 9. The image forming apparatus according to any one of configurations 1 to 8. (Configuration 10) At least a portion of the first flow path extends in a direction intersecting the second surface, At least a portion of the second flow path extends in a direction intersecting the first surface. 10. The image forming apparatus according to any one of configurations 1 to 9. (Configuration 11) a supply container having a storage space for storing toner; an apparatus main body to which the supply container is detachably attached, the apparatus main body having a storage section for storing the toner supplied from the supply container; the flow path forming portion is disposed in the device body, The first flow path, the second flow path, and the third flow path are paths through which air supplied from the air supply unit flows toward the supply container. 11. The image forming apparatus according to any one of configurations 1 to 10. (Configuration 12) The flow path forming portion has a first opening for receiving air supplied from the air supply portion, and a second opening connected to an opening provided in the refill container for taking in air from the air supply portion. 12. The image forming apparatus according to claim 11, (Configuration 13) The supply container is attached to the first member in an attachment direction, the air supply unit is disposed downstream of the first member in the mounting direction, The second opening is located upstream of the first opening in the mounting direction. 13. The image forming apparatus according to claim 12, (Configuration 14) The air supply unit is disposed above the storage unit, a position of the supply container in a vertical direction overlaps with a position of the storage portion in the vertical direction, The opening of the supply container is disposed below the air supply unit, The second opening is located below the first opening. 14. The image forming apparatus according to claim 12 or 13. (Configuration 15) a flexible tubular member having one end connected to the air supply unit and the other end connected to the first opening, The direction in which the first opening is open is different from the direction in which the second opening is open. 15. The image forming apparatus according to any one of configurations 12 to 14. (Configuration 16) the flow path forming portion is formed such that the air supplied by the air supply portion flows through a fourth flow path, a fifth flow path, and a sixth flow path in this order, in a route independent of the first flow path, the second flow path, and the third flow path; The fourth flow path is formed in a gap between the first surface and the third surface, The sixth flow path is formed in a gap between the second surface and the third surface, At least a portion of the fifth flow path is formed in a tunnel shape inside the first member, A connection portion of the fourth flow path connected to the fifth flow path and a connection portion of the fifth flow path connected to the sixth flow path are provided at a position away from the ridge line portion. 16. The image forming apparatus according to any one of configurations 1 to 15. (Configuration 17) the first surface and the third surface are bonded with an adhesive; The second surface and the fourth surface are bonded with an adhesive. 17. The image forming apparatus according to any one of configurations 1 to 16. (Configuration 18) a first seal member sandwiched between the first surface and the third surface; a second seal member sandwiched between the second surface and the fourth surface; Further comprising 18. The image forming apparatus according to any one of configurations 1 to 17. (Configuration 19) The air supply unit is an air pump. 19. The image forming apparatus according to any one of configurations 1 to 18. [Explanation of symbols]

[0168] 1A...image forming means (image forming section) / 3, 3Y, 3M, 3C, 3K...storage section (developing container) / 51...flow path forming section (cartridge holder) / 510...first member (holder main body) / 51b...second surface (lower surface) / 51f...first surface (flat surface) / 511a...first groove section (groove section) / 512a...second flow path (internal flow path) / 513a...second groove section (groove section) / 52 a... second member (connecting member) / 52a1... third surface (flat portion) / 53... third member (bottom cover) / 53b... fourth surface (upper surface) / 57a1... first flow path (upstream portion) / 57a2... third flow path (downstream portion) / 80... air supply portion (pump unit) / 430, 430Y, 430M, 430C, 430K... supply container (cartridge) / R1... ridge portion

Claims

1. An image forming apparatus, an air supply unit that supplies air for transporting the toner; a flow path forming portion formed so that the air supplied by the air supply portion flows through a first flow path, a second flow path, and a third flow path in this order; Equipped with the flow path forming portion includes a first member having a first surface and a second surface intersecting each other with a ridge portion therebetween, a second member having a third surface, and a third member having a fourth surface; The first flow path is formed in a gap between the first surface and the third surface, The third flow path is formed in a gap between the second surface and the third surface, At least a portion of the second flow path is formed in a tunnel shape inside the first member, a first connection portion connecting the first flow path and the second flow path and a second connection portion connecting the second flow path and the third flow path are provided at a position away from the ridge line portion.

1. An image forming apparatus comprising:

2. The first member has a first groove portion provided in the first surface, The first groove portion is covered by the third surface of the second member, thereby forming the first flow path.

2. The image forming apparatus according to claim 1,

3. The first member has a second groove portion provided in the second surface, The second groove portion is covered by the fourth surface of the third member, thereby forming the third flow path.

2. The image forming apparatus according to claim 1,

4. the second member has a first groove portion provided in the third surface, The first groove portion is covered with the first surface of the first member, thereby forming the first flow path.

2. The image forming apparatus according to claim 1,

5. the third member has a second groove portion provided in the fourth surface, The second groove portion is covered by the second surface of the first member, thereby forming the third flow path.

2. The image forming apparatus according to claim 1,

6. The first member has a first groove portion provided in the first surface, the second member has a third groove portion provided in the third surface, The first groove portion and the third groove portion face each other to form the first flow path.

2. The image forming apparatus according to claim 1,

7. The first member has a second groove portion provided in the second surface, the third member has a fourth groove portion provided in the fourth surface, The second groove portion and the fourth groove portion face each other to form the third flow path.

2. The image forming apparatus according to claim 1,

8. the first flow path and the ridge portion are separated by a region where the first surface and the third surface are in contact with each other, The third flow path and the ridge portion are separated by a region where the second surface and the fourth surface are in contact with each other.

8. The image forming apparatus according to claim 1, wherein the image forming apparatus is a multi-color image forming apparatus.

9. There is a gap between the second member and the third member at a position adjacent to the ridge line portion.

8. The image forming apparatus according to claim 1, wherein the image forming apparatus is a multi-color image forming apparatus.

10. At least a portion of the first flow path extends in a direction intersecting the second surface, At least a portion of the second flow path extends in a direction intersecting the first surface.

8. The image forming apparatus according to claim 1, wherein the image forming apparatus is a multi-color image forming apparatus.

11. a supply container having a storage space for storing toner; an apparatus main body to which the supply container is detachably attached, the apparatus main body having a storage section for storing the toner supplied from the supply container; the flow path forming portion is disposed in the device body, The first flow path, the second flow path, and the third flow path are paths through which air supplied from the air supply unit flows toward the refill container.

8. The image forming apparatus according to claim 1, wherein the image forming apparatus is a multi-color image forming apparatus.

12. The flow path forming portion has a first opening for receiving air supplied from the air supply portion, and a second opening connected to an opening provided in the refill container for taking in air from the air supply portion.

12. The image forming apparatus according to claim 11.

13. The supply container is attached to the first member in an attachment direction, the air supply unit is disposed downstream of the first member in the mounting direction, The second opening is located upstream of the first opening in the mounting direction.

13. The image forming apparatus according to claim 12.

14. The air supply unit is disposed above the storage unit, a position of the supply container in a vertical direction overlaps with a position of the storage portion in the vertical direction, The opening of the supply container is disposed below the air supply unit, The second opening is located below the first opening.

13. The image forming apparatus according to claim 12.

15. a flexible tubular member having one end connected to the air supply portion and the other end connected to the first opening, The direction in which the first opening is open is different from the direction in which the second opening is open.

13. The image forming apparatus according to claim 12.

16. the flow path forming portion is formed such that the air supplied by the air supply portion flows through a fourth flow path, a fifth flow path, and a sixth flow path in this order, in a route independent of the first flow path, the second flow path, and the third flow path; The fourth flow path is formed in a gap between the first surface and the third surface, The sixth flow path is formed in a gap between the second surface and the third surface, At least a portion of the fifth flow path is formed in a tunnel shape inside the first member, A connection portion of the fourth flow path connected to the fifth flow path and a connection portion of the fifth flow path connected to the sixth flow path are provided at a position away from the ridge line portion.

8. The image forming apparatus according to claim 1, wherein the image forming apparatus is a multi-color image forming apparatus.

17. the first surface and the third surface are bonded with an adhesive; The second surface and the fourth surface are bonded with an adhesive.

8. The image forming apparatus according to claim 1, wherein the image forming apparatus is a multi-color image forming apparatus.

18. a first seal member sandwiched between the first surface and the third surface; a second seal member sandwiched between the second surface and the fourth surface; Further comprising 8. The image forming apparatus according to claim 1, wherein the image forming apparatus is a multi-color image forming apparatus.

19. The air supply unit is an air pump.

8. The image forming apparatus according to claim 1, wherein the image forming apparatus is a multi-color image forming apparatus.

Images