Image forming apparatus

Abstract

An image forming apparatus includes an air supply portion and a flow passage forming portion in which a first flow passage, a second flow passage, and a third flow passage are formed. The flow channel forming portion includes a first member having a first surface and a second surface, a second member having a third surface, and a third member having a fourth surface. A first flow channel is formed in a gap between the first surface and the third surface. A third flow channel is formed in a gap between the second surface and the fourth surface. At least a portion of the second flow channel is a tunnel through the interior of the first component.

Description

Technical Field

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

[0002] Japanese Patent Laid-Open No. 2000-81778 discloses supplying toner from a toner container to a developing unit by air generated by an air pump. Summary of the Invention

[0003] The present invention provides an image forming apparatus capable of increasing the design freedom of a flow channel and suppressing a decrease in the airtightness of the flow channel.

[0004] According to an aspect of the present invention, there is provided an image forming apparatus including: an air supply unit configured to supply air for transporting toner; and a flow channel forming unit in which a first flow channel, a second flow channel, and a third flow channel are formed such that the air supplied by the air supply unit sequentially flows through the first flow channel, the second flow channel, and the third flow channel, wherein the flow channel forming unit includes a first member having a first surface and a second surface, a second member having a third surface, and a third member having a fourth surface, the first surface and the second surface intersect and have a ridge therebetween, wherein the first flow channel is formed in a gap between the first surface and the third surface, wherein the third flow channel is formed in a gap between the second surface and the fourth surface, wherein at least a part of the second flow channel is a tunnel passing through the inside of the first member, and wherein a first connection portion connecting the first flow channel and the second flow channel to each other and a second connection portion connecting the second flow channel and the third flow channel to each other are provided at positions away from the ridge.

[0005] More features of the present invention will become apparent from the following description of exemplary embodiments with reference to the drawings. Brief Description of the Drawings

[0006] Figure 1 is a schematic view of an image forming apparatus according to a first embodiment.

[0007] Figures 2A to 2C are perspective views of an image forming apparatus according to a first embodiment.

[0008] Figure 3A and Figure 3B are perspective views of an image forming unit according to a first embodiment.

[0009] Figure 4A and Figure 4BThese are top views of the image forming unit according to the first embodiment.

[0010] Figure 5A and Figure 5B These are cross-sectional views of the image forming unit according to the first embodiment.

[0011] Figure 6A and Figure 6B These are exploded views of the cartridge holder according to the first embodiment.

[0012] Figure 7A This is a rear view of the cartridge holder according to the first embodiment.

[0013] Figure 7B This is a bottom view of the cartridge holder according to the first embodiment.

[0014] Figure 7C This is a cross-sectional view of the cartridge holder according to the first embodiment.

[0015] Figures 8A to 8E These are explanatory views of the cartridge according to the first embodiment.

[0016] Figures 9A to 9C These are explanatory views of the cartridge according to the first embodiment.

[0017] Figure 10A and Figure 10B These are explanatory views of the cartridge according to the first embodiment.

[0018] Figure 11 This is a cross-sectional view of the cartridge holder according to the second embodiment.

[0019] Figure 12 This is a cross-sectional view of the cartridge holder according to the third embodiment. Detailed Description of the Embodiment

[0020] Embodiments of the present disclosure will be described in detail below with reference to the accompanying drawings.

[0021] In the present disclosure, an "image forming apparatus" generally refers to an apparatus having a function of forming an image on a sheet (recording medium) used as a recording material. The image forming apparatus may be a single-function printer, a copying machine, or a multi-function apparatus. The image forming apparatus may be an apparatus that mainly forms a color image, or may be an apparatus that mainly forms a monochrome image. Further, the image forming apparatus may be such a system (image forming system) in which accessory devices used together with the image forming apparatus main body for forming an image on a recording material are connected to the image forming apparatus main body. Examples of the accessory devices include a sheet processing apparatus (finisher) that performs a process such as a binding process on a sheet on which an image has been formed, a conveying device that conveys a sheet from the image forming apparatus main body to another apparatus, and a feeding device (optional feeder) that feeds a sheet toward the image forming apparatus main body.

[0022] First Embodiment

[0023] Reference will be made to Figure 1 describe the image forming apparatus 1 according to the first embodiment of the present disclosure. Figure 1 is a cross-sectional view taken along a plane perpendicular to the rotation axis direction of the photosensitive drum 4Y of the image forming apparatus 1.

[0024] The image forming apparatus 1 is a full-color image forming apparatus (full-color laser printer) including four-color processing units. The image forming apparatus 1 can form a full-color image on a recording material S by electrophotographic processing. Various sheet materials of different sizes and materials can be used as the recording material S (recording medium). Examples of the sheet materials include paper sheets (e.g., plain paper sheets and cardboard), sheet materials having a surface treatment (e.g., coated paper sheets), sheet materials having an irregular shape (e.g., envelopes and index paper sheets), plastic films, and cloth.

[0025] In the following description and drawings, the vertical direction (gravity direction) in the case where the image forming apparatus 1 is installed on a horizontal surface will be referred to as the Z-axis direction. The direction of the rotation axis of the photosensitive drum (image bearing member) included in the image forming apparatus 1 will be referred to as the Y-axis direction. The direction that intersects both the Z-axis direction and the Y-axis direction will be referred to as the X-axis direction. The X-axis direction, the Y-axis direction, and the Z-axis direction are preferably orthogonal to each other.

[0026] If necessary, the positive direction and the negative direction in the directions along the respective coordinate axes will be represented by using + (positive) and - (negative) signs. For example, the positive direction along the X-axis (the direction indicated by the X arrow in the figure) will be referred to as the +X direction, and the negative direction along the X-axis (the direction opposite to the arrow direction) will be referred to as the -X direction.

[0027] In addition, an element (e.g., a cartridge) that can be attached to the apparatus main body 72 of the image forming apparatus 1 and can be detached from the apparatus main body 72 will be described based on its attitude in a state of being attached to the apparatus main body 72.

[0028] As Figure 1 shown, the image forming apparatus 1 includes processing units PY, PM, PC, and PK, an intermediate transfer belt unit 11, and an apparatus main body 72. The processing units PY, PM, PC, and PK are arranged in parallel in the X-axis direction and each accommodate toner of a different color. In the following description, any one of the processing units PY, PM, PC, and PK will be described as the processing unit P. The longitudinal direction of each processing unit P is the Y-axis direction. The processing units PY, PM, PC, and PK will be referred to as the first processing unit, the second processing unit, the third processing unit, and the fourth processing unit, respectively.

[0029] Each processing unit P includes a processing element for performing electrophotographic processing. A rotational driving force is transmitted from a drive output unit (not shown) of the apparatus main body 72 to each processing unit P, and a bias voltage (charging bias voltage, developing bias voltage, etc.) is supplied from a bias voltage application unit (not shown) of the apparatus main body 72 to each processing unit P.

[0030] As Figure 1 shown, the processing units PY, PM, PC, and PK respectively include drum units 8Y, 8M, 8C, and 8K. The drum units 8Y, 8M, 8C, and 8K respectively include photosensitive drums 4Y, 4M, 4C, and 4K, and charging rollers 5Y, 5M, 5C, and 5K that serve as processing units acting on the photosensitive drums 4Y, 4M, 4C, and 4K. In the following description, any one of the drum units 8Y, 8M, 8C, and 8K will be described as the drum unit 8, any one of the photosensitive drums 4Y, 4M, 4C, and 4K will be described as the photosensitive drum 4, and any one of the charging rollers 5Y, 5M, 5C, and 5K will be described as the charging roller 5. Each photosensitive drum 4 is arranged such that the direction of its rotation axis is the Y-axis direction and can rotate around the rotation axis. The photosensitive drums 4Y, 4M, 4C, and 4K serve as the first photosensitive drum, the second photosensitive drum, the third photosensitive drum, and the fourth photosensitive drum, respectively.

[0031] The processing units PY, PM, PC, and PK respectively include developing units 9Y, 9M, 9C, and 9K. The developing units 9Y, 9M, 9C, and 9K respectively include developing rollers 6Y, 6M, 6C, and 6K. Each of the developing rollers 6Y, 6M, 6C, and 6K develops the electrostatic latent image on the corresponding photosensitive drum 4. The developing units 9Y, 9M, 9C, and 9K are arranged in parallel in the X-axis direction. The developing rollers 6Y, 6M, 6C, and 6K respectively serve as the first developing roller, the second developing roller, the third developing roller, and the fourth developing roller. The developing units 9Y, 9M, 9C, and 9K respectively serve as the first developing unit, the second developing unit, the third developing unit, and the fourth developing unit. In the following description, any one of the developing units 9Y, 9M, 9C, and 9K will be described as the developing unit 9, and any one of the developing rollers 6Y, 6M, 6C, and 6K will be described as the developing roller 6.

[0032] The developing units 9Y, 9M, 9C, and 9K respectively include developing containers 3Y, 3M, 3C, and 3K. In the following description, any one of the developing containers 3Y, 3M, 3C, and 3K will be referred to as the developing container 3. The developing unit 9Y includes a developing container 3Y (first developing container) that houses yellow (Y) toner (first toner), and is configured such that the yellow toner is supplied to the surface of the photosensitive drum 4Y by the developing roller 6Y that carries the yellow toner. The developing unit 9M includes a developing container 3M (second developing container) that houses magenta (M) toner (second toner), and is configured such that the magenta toner is supplied to the surface of the photosensitive drum 4M by the developing roller 6M that carries the magenta toner. The developing unit 9C includes a developing container 3C (third developing container) that houses cyan (C) toner (third toner), and is configured such that the cyan toner is supplied to the surface of the photosensitive drum 4C by the developing roller 6C that carries the cyan toner. The developing unit 9K includes a developing container 3K (fourth developing container) that houses black (K) toner (fourth toner), and is configured such that the black toner is supplied to the surface of the photosensitive drum 4K by the developing roller 6K that carries the black toner.

[0033] In the Z-axis direction that intersects both the X-axis direction and the Y-axis direction, a laser scanner unit LB (exposure unit) is disposed above the processing units PY, PM, PC, and PK (photosensitive drums 4Y, 4M, 4C, and 4K). The laser scanner unit LB outputs a laser corresponding to the image information. Hereinafter, the optical paths of the lasers directed toward the photosensitive drums 4Y, 4M, 4C, and 4K will be represented by LY, LM, LC, and LK, respectively. The laser emitted from the laser scanner unit LB scans and exposes the surfaces of the photosensitive drums 4Y, 4M, 4C, and 4K. It should be noted that an LED exposure unit can be used instead of the laser scanner unit LB.

[0034] In the Z-axis direction, an intermediate transfer belt unit 11 including a transfer belt 12 serving as a transfer member (intermediate transfer member) is provided below the process unit P. The intermediate transfer belt unit 11 includes a driving roller 14, a tension roller 13, and an auxiliary roller 15. The transfer belt 12 having flexibility and an endless shape is stretched around these rollers.

[0035] The lower surface of each photosensitive drum 4 is in contact with 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 will be referred to as primary transfer portions 30Y, 30M, 30C, and 30K (hereinafter referred to as primary transfer portions 30), respectively. On the inner peripheral side of the transfer belt 12, primary transfer rollers 16Y, 16M, 16C, and 16K (hereinafter referred to as transfer rollers 16) are provided to oppose the photosensitive drums 4Y, 4M, 4C, and 4K.

[0036] The secondary transfer roller 17 is in pressure contact with the driving roller 14 via the transfer belt 12. The contact portion between the transfer belt 12 and the secondary transfer roller 17 serves as a secondary transfer portion 31. The secondary transfer portion 31 is a transfer portion that transfers an image (toner image) onto the recording material S by the image forming portion 1A.

[0037] The process units PY, PM, PC, and PK and the intermediate transfer belt unit 11 constitute a tandem / intermediate transfer type image forming section 1A serving as an image forming section of the present embodiment. The image forming section 1A forms an image (developer image) by using toner (developer) contained in developing containers 3Y, 3M, 3C, and 3K serving as containing sections.

[0038] The feeding unit 18 is provided at the lower portion of the apparatus body 72 (a portion located below the intermediate transfer belt unit 11 in the Z-axis direction). The feeding unit 18 includes a feeding tray 19 (sheet accommodating portion) that accommodates a stack of recording materials S, and a feeding roller 20 that serves as a feeding member that picks up the recording materials S from the feeding tray 19 and conveys the recording materials S.

[0039] At the upper part of the apparatus main body 72, a fixing unit 21 and a discharging roller 22 are provided. The fixing unit 21 fixes the toner image to the recording material S, and the discharging roller 22 serving as a discharging member discharges the recording material S on which the toner image has been fixed onto a discharging tray 23. The discharging roller 22 discharges the recording material S in the direction along the X-axis. The fixing unit 21 includes a pair of rotating members and a heating unit (such as a halogen lamp, a ceramic heater, etc.) that heats the toner image on the recording material S, and the pair of rotating members forms a clamping unit (fixing clamping unit) that clamps and conveys the recording material S. It should be noted that, in the present embodiment, the downstream side in the discharging direction in which the recording material S is discharged by the discharging roller 22 toward the discharging tray 23 will be referred to as the front side of the image forming apparatus 1, and the upstream side in the discharging direction will be referred to as 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.

[0040] It should be noted that each processing unit P may be a processing cartridge that can be attached to the apparatus main body 72 and can be detached from the apparatus main body 72. Additionally, a configuration may be adopted in which only the developing unit 9 in each processing unit P is a unit (developing cartridge) that can be attached to the apparatus main body 72 and can be detached from the apparatus main body 72.

[0041] Image forming operation

[0042] The operation for forming a full-color image is as described below. The photosensitive drums 4Y, 4M, 4C, and 4K are rotationally driven in the counterclockwise direction in Figure 1 . As the photosensitive drums 4Y, 4M, 4C, and 4K rotate, the transfer belt 12 is rotationally driven in the rotational direction at a speed corresponding to the rotational speed (circumferential speed) of the photosensitive drums 4Y, 4M, 4C, and 4K.

[0043] The laser scanner unit LB is also driven. In each processing unit P, in synchronization with the driving of the laser scanner unit LB, the charging roller 5 uniformly charges the surface of the photosensitive drum 4 to a predetermined polarity and a predetermined electric potential. The laser scanner unit LB scans and exposes the charged surfaces of the photosensitive drums 4Y, 4M, 4C, and 4K with the lasers LY, LM, LC, and LK respectively according to the image signals of various colors, thereby forming electrostatic latent images corresponding to the image signals of various colors on the surfaces of the photosensitive drums 4Y, 4M, 4C, and 4K. That is, the laser scanner unit LB exposes the photosensitive drum 4Y and the photosensitive drum 4M, thereby forming a first electrostatic latent image and a second electrostatic latent image on the photosensitive drum 4Y and the photosensitive drum 4M respectively. Similarly, the laser scanner unit LB exposes the photosensitive drum 4C and the photosensitive drum 4K, thereby forming a third electrostatic latent image and a fourth electrostatic latent image on the photosensitive drum 4C and the photosensitive drum 4K respectively.

[0044] By rotating at a predetermined speed along Figure 1The clockwise rotation-driven developing roller 6 in it supplies toner to the photosensitive drum 4 to develop the electrostatic latent image on each photosensitive drum 4. A yellow toner image is formed on the photosensitive drum 4Y of the processing unit PY through the image forming process of the above-described electrophotographic system. Then, the yellow toner image is transferred onto the transfer belt 12 by primary transfer. Similarly, a magenta toner image is formed on the photosensitive drum 4M of the processing unit PM. Then, the magenta toner image is transferred onto the transfer belt 12 by primary transfer, so that the magenta toner image is superimposed on the yellow toner image on the transfer belt 12. A cyan toner image is formed on the photosensitive drum 4C of the processing unit PC. Then, the cyan toner image is transferred onto the transfer belt 12 by primary transfer, so that the cyan toner image is 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 processing unit PK. Then, the black toner image is transferred onto the transfer belt 12 by primary transfer, so that the black toner image is superimposed on the yellow, magenta, and cyan toner images on the transfer belt 12.

[0045] In this way, an unfixed full-color toner image of yellow, magenta, cyan, and black is formed on the transfer belt 12. At the same time, the recording material S is fed one by one from the feed tray 19 by the feed roller 20 at a predetermined control timing while being separated from each other. The recording material S is introduced into the secondary transfer section 31 (i.e., the contact section between the secondary transfer roller 17 and the transfer belt 12) at a predetermined control timing. During the conveyance of the recording material S in the secondary transfer section 31, the four-color 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 pressed by the fixing unit 21, thereby fixing the toner image onto the recording material S. The recording material S onto which the toner image is fixed is discharged onto the discharge tray 23 by the discharge roller 22.

[0046] Layout, attachment, and detachment of the toner cartridge

[0047] The layout of the toner cartridge will be described with reference to FIG. 2. The image forming apparatus 1 includes cartridges 430Y, 430M, 430C, and 430K as supply containers that can be attached to and detached from the apparatus main body 72. In the following description, any one of the cartridges 430Y, 430M, 430C, and 430K will be described as the cartridge 430.

[0048] The cartridges 430Y, 430M, 430C, and 430K are arranged in a row in a direction crossing (orthogonal to) the direction in which the developing unit 9 is arranged in a row. The cartridges 430Y, 430M, 430C, and 430K of the present embodiment are arranged in parallel in the Y-axis direction. The cartridges 430Y, 430M, 430C, and 430K will be referred to as the first cartridge (first toner container), the second cartridge (second toner container), the third cartridge (third toner container), and the fourth cartridge (fourth toner container), respectively.

[0049] Figure 2A is a perspective view of the image forming apparatus 1 with the front door 72b closed. Figure 2B is a perspective view of the image forming apparatus 1 with the front door 72b open. Figure 2C 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.

[0050] As Figure 2B shown, the cartridges 430Y, 430M, 430C, and 430K are attached to the upper part of the front side of the apparatus main body 72 so that each cartridge 430 can be operated by opening the front door 72b. In other words, each cartridge 430 is provided at the end of the apparatus main body 72 on the downstream side in the discharging direction of the discharging roller 22. The front door 72b is configured to be movable to a closed position (see Figure 2A ) to close the opening on the front side of the apparatus main body 72 and to be movable to an open position (see Figure 2B ) to open the opening. As Figure 2B shown, 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.

[0051] As Figure 2C shown, the cartridges 430Y, 430M, 430C, and 430K are arranged in the Y-axis direction and are configured to be attachable to and detachable from the apparatus main body 72 in the X-axis direction. Therefore, toner can be supplied to the processing units PY, PM, PC, and PK without detaching the processing units PY, PM, PC, and PK from the apparatus main body 72. Since each cartridge 430 is provided on the front side of the image forming apparatus 1, each cartridge 430 can be operated from the front side in a similar manner to the case of collecting the recording material S discharged onto the discharge tray 23. In addition, since the cartridge holder 51 is provided on the front side of the image forming apparatus 1, the processing unit P is not exposed even after each cartridge 430 is detached (see Figure 2C ). Each cartridge 430 is accommodated in the apparatus main body 72 with the front door 72b closed.

[0052] As Figure 2AAs shown, indicators 208Y, 208M, 208C, and 208K of various colors (indicating unit, display unit) are provided on the front side of the image forming apparatus 1. Indicators 208Y, 208M, 208C, and 208K are arranged along the Y-axis direction corresponding to cartridges 430Y, 430M, 430C, and 430K. Indicator 208Y (first indicator) is yellow, indicator 208M (second indicator) is magenta, indicator 208C (third indicator) is cyan, and indicator 208K (fourth indicator) is black. Each of indicators 208Y, 208M, 208C, and 208K is constituted by a light emitting diode (LED) or a sticker whose color corresponds to the toner color of the corresponding one of cartridges 430, and is provided so that cartridges 430 are not attached erroneously. In addition, each of indicators 208Y, 208M, 208C, and 208K can be given a display function of displaying the remaining toner amount in the corresponding processing unit P (developing unit 9).

[0053] As Figure 2B shown, the apparatus main body 72 includes an inclined portion 51a provided on the lower side of the cartridge holder 51. The inclined portion 51a is an inclined surface facing obliquely upward toward the front side of the image forming apparatus 1. In other words, the inclined portion 51a is inclined downward (toward the -Z side) with respect to the horizontal plane toward the front side (+X side) of the image forming apparatus 1. Labels 210 corresponding to the toner colors of cartridges 430Y, 430M, 430C, and 430K are attached to the inclined portion 51a. When the user replaces each cartridge, since the labels 210 on the inclined portion 51a can be visually recognized, each cartridge 430 can be attached to a predetermined position.

[0054] Image forming unit

[0055] will be described with reference to Figures 3A to 5B the toner conveyance mechanism from each cartridge 430 to the corresponding one of the processing units in the processing unit P.

[0056] A unit including cartridges 430Y, 430M, 430C, and 430K, processing units PY, PM, PC, and PK, and a toner conveyance path to be described later will be referred to as an image forming unit 50. The toner conveyance path is a toner conveyance route (toner conveyance mechanism) from each cartridge 430 to the corresponding one of the processing units in the processing unit P.

[0057] Figure 3A is a perspective view of the image forming unit 50 in a state where cartridges 430Y, 430M, 430C, and 430K are attached to the image forming unit 50. Figure 3B is a perspective view of the image forming unit 50 in a state where cartridges 430Y, 430M, 430C, and 430K have been detached from the image forming unit 50. Figure 4AIt is a top view of the laser scanner unit LB and the image forming unit 50. Figure 4B It is a top view of the image forming unit 50. Figure 5A and Figure 5B are cross-sectional views showing the A-A cross-section and the B-B cross-section of Figure 4A respectively. In Figures 3A to 5B , the front side (+X side) of the image forming apparatus 1 is indicated by "FE", and the rear side (-X side) thereof is indicated by "BE". When observing the image forming apparatus 1 from the front side to the rear side, the right end side (+Y side) thereof is indicated by "RE", and the left end side (-Y side) thereof is indicated by "LE".

[0058] As Figure 3A shown, the processing units PY, PM, PC, and PK are arranged in parallel in the X-axis direction in the image forming unit 50. Each processing unit P is attached to the tray 55. The cassette holder 51 is provided in front of the tray 55, and the cassettes 430Y, 430M, 430C, and 430K are attached to the cassette holder 51. The cassettes 430Y, 430M, 430C, and 430K are arranged in parallel in the Y-axis direction.

[0059] That is to say, the apparatus main body 72 includes the cassette holder 51 that serves as a holding member (the attached portion to which the cassette 430 is attached) for holding each cassette 430. The cassette holder 51 defines an attachment space for attaching each cassette 430. The attachment space in this embodiment is the space between the cassette holder 51 and the front door 72b ( Figure 1 and Figure 2A ) in the closed state. The cassette holder 51 is fixed to the frame main body of the apparatus main body 72. The cassette holder 51 may be a part of the frame main body of the apparatus main body 72.

[0060] The pump unit 80 is provided above the processing unit PK. The pump unit 80 is supported by the support member 56 and attached to the cassette holder 51. The pump unit 80 includes four air pumps for supplying air to the cassettes 430Y, 430M, 430C, and 430K respectively. As each pump in the pump unit 80, a positive displacement pump such as a reciprocating pump or a rotary pump is used. A reciprocating pump is a pump that performs suction and discharge through the reciprocating motion of a piston, a plunger, etc., and examples thereof include a piston pump, a plunger pump, and a diaphragm pump. A rotary pump is a pump that performs suction and discharge through the rotary motion of a gear, a rotor, etc., and examples thereof include a gear pump, a screw pump, and a vane pump.

[0061] Although the pump unit 80 is provided in the image forming unit 50 in the present embodiment, the pump unit 80 may be provided in each cartridge 430 or in other parts of the apparatus main body 72. In addition, the pump unit 80 (air pump) is an example of an air supply unit or supply section that supplies air to transport toner from each cartridge 430 to the developing unit 99, and for example, a fan (axial flow fan, sirocco fan, etc.) may be used as the air supply section.

[0062] Cartridge holder

[0063] Figure 6A is an exploded perspective view of the cartridge holder 51 (as viewed from the front side). Figure 6B is an exploded perspective view of the cartridge holder 51 (as viewed from the rear side). Figure 7A is a view showing the cartridge holder 51 as viewed from the rear side (-X side). Figure 7B is a view showing the cartridge holder 51 as viewed from the lower side (-Z side) (bottom view). Figure 7C is along Figure 7A a cross-sectional view of the cartridge holder 51 taken along line A-A.

[0064] As Figures 6A to 7B shown, the cartridge holder 51 includes a holder body 510, connecting members 52a, 52b, 52c, and 52d, and a bottom cover 53. The holder body 510 is an example of a first member, the connecting 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 connecting members 52a, 52b, 52c, and 52d, and the bottom cover 53 are formed as a single unit joined by a method such as adhesion. The holder body 510, the connecting members 52a, 52b, 52c, and 52d, and the bottom cover 53 may all be molded resin products formed by a method such as injection molding.

[0065] The cartridge holder 51 is an example of a flow channel forming section that forms a flow channel through which air flows to supply toner from the cartridge 430 serving as a replenishment container to a corresponding one of the developing containers 3 (accommodating sections). The cartridge holder 51 of the present embodiment defines an attachment space for attaching the cartridge 430, serves as a holding member for holding the cartridge 430, and serves as a flow channel forming section for forming an air flow channel.

[0066] The cartridge holder 51 has air connection ports 521, 522, 523, and 524, and air discharge ports 514a, 514b, 514c, and 514d. In addition, the cartridge holder 51 has toner inlet ports 515a, 515b, 515c, and 515d, and toner connection ports 525, 526, 527, and 528.

[0067] The air connection port 521 and the air discharge port 514a are connected to each other through the air flow passage 57a in the cassette holder 51. The air connection port 522 and the air discharge port 514b are connected to each other through the air flow passage 57b in the cassette holder 51. The air connection port 523 and the air discharge port 514c are connected to each other through the air flow passage 57c in the cassette holder 51. The air connection port 524 and the air discharge port 514d are connected to each other through the air flow passage 57d in the cassette holder 51. These air flow passages 57a, 57b, 57c, and 57d are all flow paths through which the air supplied from the pump unit 80 (air supply unit) flows toward the respective cassettes 430 (refill containers).

[0068] The cassette holder 51 is configured such that the air supplied from the pump unit 80 sequentially flows through the upstream portion 57a1 (first flow passage), the internal flow passage 512a (second flow passage), and the downstream portion 57a2 (third flow passage) of the air flow passage 57a, which will be described hereinafter. In addition, the cassette holder 51 is configured such that the air supplied from the pump unit 80 sequentially flows through the upstream portion 57b1 (fourth flow passage), the internal flow passage 512b (fifth flow passage), and the downstream portion 57b2 (sixth flow passage) of the air flow passage 57b, which is a path independent of the air flow passage 57a. Similarly, the cassette holder 51 is configured such that the air supplied from the pump unit 80 sequentially flows through the upstream portion 57c1, the internal flow passage 512c, and the downstream portion 57c2 of the air flow passage 57c. In addition, the cassette holder 51 is configured such that the air supplied from the pump unit 80 sequentially flows through the upstream portion 57d1, the internal flow passage 512d, and the downstream portion 57d2 of the air flow passage 57d, which is a path independent of the air flow passage 57c.

[0069] When the cassette 430Y is attached to the cassette holder 51, the air discharge port 514a is connected to the inlet port 430Yb1 (to be described later) of the cassette 430Y, and the toner inlet port 515a is connected to the discharge port 430Ya1 of the cassette. When the cassette 430M is attached to the cassette holder 51, the air discharge port 514b is connected to the inlet port 430Mb1 (to be described later) of the cassette 430M, and the toner inlet port 515b is connected to the discharge port 430Ma1 of the cassette. When the cassette 430C is attached to the cassette holder 51, the air discharge port 514c is connected to the inlet port 430Cb1 (to be described later) of the cassette 430C, and the toner inlet port 515c is connected to the discharge port 430Ca1 of the cassette. When the cassette 430K is attached to the cassette holder 51, the air discharge port 514d is connected to the inlet port 430Kb1 (to be described later) of the cassette 430K, and the toner inlet port 515d is connected to the discharge port 430Ka1 of the cassette.

[0070] The toner inlet port 515a and the toner connection port 525 are connected to each other through a toner flow channel in the cartridge holder 51. The toner inlet port 515b and the toner connection port 526 are connected to each other through a toner flow channel in the cartridge holder 51. The toner inlet port 515c and the toner connection port 527 are connected to each other through a toner flow channel in the cartridge holder 51. The toner inlet port 515d and the toner connection port 528 are connected to each other through a toner flow channel in the cartridge holder 51. These toner flow channels are all paths through which air including the toner discharged from each cartridge 430 flows toward a corresponding one of the developing units in the developing unit 9.

[0071] That is, as a structure for transporting toner from the cartridge 430Y by using air, the cartridge holder 51 includes an air flow channel 57a (which includes an air connection port 521 and an air discharge port 514a) and a toner flow channel (which includes a toner inlet port 515a and a toner connection port 525). As a structure for transporting toner from the cartridge 430M by using air, the cartridge holder 51 includes an air flow channel 57b (which includes an air connection port 522 and an air discharge port 514b) and a toner flow channel (which includes a toner inlet port 515b and a toner connection port 526). As a structure for transporting toner from the cartridge 430C by using air, the cartridge holder 51 includes an air flow channel 57c (which includes an air connection port 523 and an air discharge port 514c) and a toner flow channel (which includes a toner inlet port 515c and a toner connection port 527). As a structure for transporting toner from the cartridge 430K by using air, the cartridge holder 51 includes an air flow channel 57d (which includes an air connection port 524 and an air discharge port 514d) and a toner flow channel (which includes a toner inlet port 515d and a toner connection port 528).

[0072] The air connection port 521 is an example of a first opening for receiving air supplied from an air supply unit. The air discharge port 514a is an example of a second opening that is connected to an opening (the inlet port 430Yb1 to be described below) provided in the replenishment container for sucking air.

[0073] Air supply path from the pump to the cartridge

[0074] will be described in detail Figures 5A to 7C the air supply path from the pump unit 80 to each cartridge 430.

[0075] As Figure 5A and Figure 5BAs shown, the four ejection ports of the pump unit 80 are respectively connected to the air connection ports 521, 522, 523, and 524 of the cartridge holder 51 via four air supply tubes 61. Although only the air supply tube 61Y connected to the air connection port 521 is shown in Figure 5A and Figure 5B , the other three ejection ports of the pump unit 80 are respectively connected to the air connection ports 522, 523, and 524 via their respective corresponding three air supply tubes 61. The air supply tube 61Y is a flexible tubular 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).

[0076] The outer diameter of the air connection port 521 is slightly larger than the inner diameter of the end portion 61Yu ( Figure 5B ) of the air supply tube 61Y. The end portion 61Yu of the air supply tube 61Y is connected by press-fitting to the air connection port 521. Thereby, air leakage from the connection portion between the air supply tube 61Y and the air connection port 521 can be suppressed. Similarly, the outer diameters of the air connection ports 522, 523, and 524 are slightly larger than the inner diameters of the end portions of the corresponding one of the air supply tubes 61.

[0077] 1. Air supply path of the cartridge 430Y

[0078] First, details of the air supply path of the cartridge 430Y will be described. As Figure 6A and Figure 6B shown, the air connection port 521 is provided in the connection member 52a. The holder body 510 (first member) includes a flat surface portion 51f (first surface, first flat surface portion) opposite to the connection member 52a. The connection member 52a (second member) includes a flat surface portion 52a1 (third surface, third flat surface portion) opposite to the holder body 510. In the present embodiment, the connection member 52a is joined to the holder body 510 by bonding the flat surface portions 51f and 52a1 together using an adhesive. The flat surface portion 51f of the holder body 510 and the flat surface portion 52a1 of the connection member 52a are substantially parallel surfaces. The flat surface portions 51f and 52a1 of the present embodiment extend in a direction crossing the X-axis direction. The flat surface portion 51f of the holder body 510 is a surface facing the 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.

[0079] The flat surface portion 51f of the holding member body 510 has a groove portion 511a (first groove portion). The groove portion 511a is a groove shape (concave shape) that is recessed in a direction away from the flat surface portion 52a1 (in the +X direction in this embodiment) in a direction in which the flat surface portion 51f of the holding member body 510 and the flat surface portion 52a1 of the connecting member 52a face each other (a direction orthogonal to the flat surface portion 52a1, approximately the X-axis direction). When the holding member body 510 and the connecting member 52a are joined together, the groove portion 511a is covered by the flat surface portion 52a1 of the connecting member 52a. Thereby, the upstream portion 57a1 ( Figure 7A and Figure 7C , the first flow channel) of the air flow channel 57a is formed.

[0080] In other words, one of the first surface and the third surface is provided with a first groove portion that is recessed in a first direction in which the first surface and the third surface face each other in a direction away from the other of the first surface and the third surface. The first groove portion is covered by the first member or the second member including the other of the first surface and the third surface, thereby forming the first part of the flow channel. The groove portion 511a serving as the first groove portion of the present embodiment is provided in the flat surface portion 51f of the holding member body 510 serving as the first surface, but as will be described later in the second embodiment, the first groove portion may be provided in the flat surface portion 52a1 (the third surface of the second member) of the connecting member 52a. That is, the upstream portion 57a1 (the first flow channel) of the air flow channel 57a1 is a space defined in the gap between the flat surface portion 51f (the first surface) of the holding member body 510 and the flat surface portion 52a1 (the third surface) of the connecting member 52a. The "gap" may be a gap defined by the groove portion provided in one of the first surface and the third surface being covered by the other of the first surface and the third surface, or a gap defined by the groove portions respectively provided in the first surface and the third surface facing each other.

[0081] At least a part of the groove portion 511a extends in a direction intersecting with the lower surface portion 51b (second surface, second flat surface portion) to be described below. Thereby, the air flow channel 57a can extend in a direction different from the in-plane direction of the lower surface portion 51b. The groove portion 511a of the present embodiment extends substantially along the Z-axis direction ( Figure 7A ). It should be noted that the extending direction of the groove portion 511a can be changed within the in-plane direction of the flat surface portion 51f, and the groove portion 511a can be bent one or more times within the surface of the flat surface portion 51f.

[0082] In addition, the hole 521a ( Figure 6Ais provided at a position in the flat surface portion 52a1 of the connecting member 52a that faces the end portion (upper end portion) of the groove portion 511a. The hole 521a communicates with the air connection port 521 through a flow channel formed inside the connecting member 52a. When the holder body 510 and the connecting member 52a are joined together, the hole 521a faces the end portion of the groove portion 511a. As a result, the air connection port 521 communicates with the upstream portion 57a1 of the air flow channel 57a.

[0083] In addition, the holder body 510 (first member) includes a lower surface portion 51b that serves as a flat surface portion (second surface, second surface portion) facing the bottom cover 53. The lower surface portion 51b is a flat surface portion that intersects the flat surface portion 51f at the ridge portion R1. The bottom cover 53 (third member) includes an upper surface portion 53b that serves as a flat surface portion (fourth surface, fourth flat surface portion) facing the holder body 510. In this embodiment, since the upper surface portion 53b is bonded to the lower surface portion 51b of the holder body 510, the bottom cover 53 is joined to the holder body 510. 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 this embodiment extend in a direction intersecting the Z-axis direction. The lower surface portion 51b of the holder body 510 is a surface facing one side (-Z side, lower side) in the Z-axis direction, and the upper surface portion 53b of the bottom cover 53 is a surface facing the other side (+Z side, upper side) in the Z-axis direction.

[0084] A groove portion 513a (second groove portion) is provided in the lower surface portion 51b of the holder body 510. The groove portion 513a has a groove shape (concave shape) that is recessed in a direction away from the upper surface portion 53b (in the +Z direction in this embodiment) in a direction in which the lower surface portion 51b and the upper surface portion 53b of the bottom cover 53 face each other (a direction orthogonal to the lower surface portion 51b, substantially the Z-axis direction). When the holder body 510 and the bottom cover 53 are joined together, the groove portion 513a is covered by the upper surface portion 53b of the bottom cover 53. As a result, the downstream portion 57a2 of the air flow channel 57a ( Figure 7B and Figure 7C , second flow channel) is formed.

[0085] In other words, one of the second surface and the fourth surface is provided with a second groove portion that is recessed in a direction away from the other of the second surface and the fourth surface in a direction in which the second surface and the fourth surface face each other. The second groove portion is covered by the first member or the third member including the other of the second surface and the fourth surface, thereby forming a second portion of the flow channel. The groove portion 513a serving as the second groove portion of the present embodiment is provided in the lower surface portion 51b of the holder body 510 serving as the first member, which is the second surface. However, as will be described later in the second embodiment, the second groove portion may be provided in the upper surface portion 53b (the fourth surface of the third member) of the bottom cover 53. That is, the downstream portion 57a2 (the third flow channel) of the air flow channel 57a is a space defined in the gap between the lower surface portion 51b (the second surface) of the holder body 510 and the upper surface portion 53b (the fourth surface) of the bottom cover 53. The "gap" may be a gap defined by the groove portion provided in one of the second surface and the fourth surface being covered by the other of the second surface and the fourth surface, or a gap defined by groove portions respectively provided in the second surface and the fourth surface facing each other.

[0086] At least a part of the groove portion 513a extends in a direction intersecting the flat surface portion 51f (the first surface, the first flat surface portion). Thereby, the air flow channel 57a can extend in a direction different from the in-plane direction of the flat surface portion 51f. The groove portion 513a of the present embodiment extends substantially in the X-axis direction ( Figure 7B ) along the lower surface portion 51b. It should be noted that the extending direction of the groove portion 513a can be changed within the in-plane direction of the lower surface portion 51b, and the groove portion 513a can be bent one or more times within the surface of the lower surface portion 51b.

[0087] Furthermore, the end portion (+X side end portion) of the groove portion 513a communicates with the air discharge port 514a through a hole provided in the holder body 510 ( Figure 7C ). Therefore, when the holder body 510 and the bottom cover 53 are joined together, the downstream portion 57a2 of the air flow channel 57a communicates with the air discharge port 514a.

[0088] As described above, by providing the groove portions 511a and 513a on the two surfaces (the flat surface portion 51f and the lower surface portion 51b) of the holder body 510 respectively, an air flow channel 57a having a curved shape (which cannot be achieved in a single plane) can be formed. Specifically, in the present embodiment, by providing the groove portion 511a extending substantially in the Z-axis direction in the flat surface portion 51f, the air connection port 521 and the air discharge port 514a provided at different positions in the Z-axis direction can be connected to each other through the air flow channel 57a. In addition, by providing the groove portion 513a extending substantially in the X-axis direction in the lower surface portion 51b, the air connection port 521 and the air discharge port 514a provided at different positions in the X-axis direction can be connected to each other through the air flow channel 57a.

[0089] In addition, in the holder body 510, an internal flow channel 512a communicating with the groove portion 511a and the groove portion 513a is provided. The internal flow channel 512a is formed in a tunnel shape inside the holder body 510. One end of the internal flow channel 512a opens to the groove portion 511a at a position away from the ridge 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 channel 512a opens to the groove portion 513a at a position away from the ridge R1 of the holder body 510 in the X-axis direction. Thereby, the airtightness of the air flow channel 57a can be more easily improved. The opening portion 512a1 of the internal flow channel 512a to the groove portion 511a is the first connection portion connecting the upstream portion 57a1 (the first flow channel) of the air flow channel 57a and the internal flow channel 512a (the second flow channel). The opening portion 512a2 of the internal flow channel 512a to the groove portion 513a is the second connection portion connecting the internal flow channel 512a (the second flow channel) of the air flow channel 57a and the downstream portion 57a2 (the third flow channel).

[0090] In other words, the internal flow channel 512a is a path extending inside the holder body 510 and bypassing the ridge R1 at the same time, and is configured to connect the upstream portion 57a1 and the downstream portion 57a2 of the air flow channel 57a to each other. It should be noted that the end portion 511a1 of the groove portion 511a on the side close to the ridge R1 ( Figure 7C ) is provided at a position away from the ridge R1 in the Z-axis direction. The end portion 513a1 of the groove portion 513a on the side close to the ridge R1 ( Figure 7C ) is provided at a position away from the ridge R1 in the X-axis direction. That is to say, both the groove portions 511a and 513a are formed so as not to reach the ridge R1.

[0091] Preferably, when viewed in a first direction (substantially the X-axis direction) in which the flat surface portion 51f of the holding member body 510 and the flat surface portion 52a1 of the connecting member 52a face each other, a region Rc1 where the flat surface portion 51f and the flat surface portion 52a1 abut against each other is provided between the groove portion 511a and the ridge portion R1. That is, preferably, an upstream portion 57a1 (first flow channel) of the air flow channel 57a and the ridge portion R1 are separated by the region Rc1 where the flat surface portion 51f (first surface) and the flat surface portion 52a1 (third surface) abut against each other. In addition, preferably, when viewed in a second direction (substantially the Z-axis direction) in which the lower surface portion 51b of the holding member body 510 and the upper surface portion 53b of the bottom cover 53 face each other, a region Rc2 where the lower surface portion 51b and the upper surface portion 53b abut against each other is provided between the groove portion 513a and the ridge portion R1. That is, preferably, a downstream portion 57a2 (third flow channel) of the air flow channel 57a and the ridge portion R1 are separated by the region Rc2 where the lower surface portion 51b (second surface) and the upper surface portion 53b (fourth surface) abut against each other. Thereby, the airtightness of the air flow channel 57a can be more reliably improved. Note that, more preferably, when viewed in the first direction, the entire periphery of the groove portion 511a is surrounded by the contact region between the flat surface portions 51f and 52a1. In addition, more preferably, when viewed in the second direction, the entire periphery of the groove portion 513a is surrounded by the contact region between the lower surface portion 51b and the upper surface portion 53b.

[0092] The internal flow channel 512a of the present embodiment is formed in a substantially L shape, which includes a portion extending substantially in the +X direction from an end portion 511a1 on the side of the groove portion 511a close to the ridge portion R1 and a portion extending substantially in the +Z direction from an end portion 513a1 on the side of the groove portion 513a close to the ridge portion R1.

[0093] Note that, as a method for molding the holding member body 510, injection molding can be considered with the substantially X-axis direction as the opening and closing direction of the mold based on the attitude of the holding member body 510 attached to the device body 72. In this case, although the groove portion 513a, a part of the internal flow channel 512a, and the air discharge port 514a are undercuts, these parts can be demolded from the mold by using, for example, a slide core that slides in the Z-axis direction.

[0094] 2. Air supply path of the cartridge 430M

[0095] The air supply path of the cartridge 430M is substantially the same as the air supply path of the cartridge 430Y.

[0096] As Figure 6A and Figure 6BAs shown, an air connection port 522 is provided in a connection member 52a. A flat surface portion 51f of a holder body 510 has a groove portion 511b. When the holder body 510 and the connection member 52a are joined together, the groove portion 511b is covered by a flat surface portion 52a1 of the connection member 52a. Thus, an upstream portion (a first part of a flow path) of an air flow channel 57b is formed.

[0097] The groove portion 511b of the present embodiment extends substantially in the Z-axis direction ( Figure 7A ). It should be noted that the extending direction of the groove portion 511b can be changed within the in-plane direction of the flat surface portion 51f, and the groove portion 511b can be bent one or more times within the surface of the flat surface portion 51f.

[0098] In addition, a hole 522a ( Figure 6A ) is provided at a position in the flat surface portion 52a1 of the connection member 52a that is opposite to an end portion (an upper end portion) of the groove portion 511b. The hole 522a communicates with the air connection port 522 through a flow channel formed inside the connection member 52a. When the holder body 510 and the connection member 52a are joined together, the hole 522a is opposite to the end portion of the groove portion 511b. Thus, the air connection port 522 communicates with the upstream portion 57a1 of the air flow channel 57b.

[0099] A groove portion 513b is provided in a lower surface portion 51b of the holder body 510. When the holder body 510 and a bottom cover 53 are joined together, the groove portion 513b is covered by an upper surface portion 53b of the bottom cover 53. Thus, a downstream portion (a second part of a flow path) of the air flow channel 57b is formed.

[0100] The groove portion 513b of the present embodiment extends along the lower surface portion 51b toward the +X side and the +Y side ( Figure 7B ). It should be noted that the extending direction of the groove portion 513b can be changed within the in-plane direction of the lower surface portion 51b, and the groove portion 513b can be bent one or more times within the surface of the lower surface portion 51b.

[0101] In addition, an end portion (+X side end portion) of the groove portion 513b communicates with an air discharge port 514b through a hole provided in the holder body 510 ( Figure 7C ). Therefore, when the holder body 510 and the bottom cover 53 are joined together, the downstream portion of the air flow channel 57b communicates with the air discharge port 514b.

[0102] As described above, by providing the groove portions 511b and 513b on the two surfaces (the flat surface portion 51f and the lower surface portion 51b) of the holder body 510, respectively, an air flow passage 57b having a curved shape (which cannot be achieved in a single plane) can be formed.

[0103] In addition, an internal flow passage 512b communicating with the groove portion 511b and the groove portion 513b is provided in the holder body 510. The internal flow passage 512b is formed in a tunnel shape inside the holder body 510. One end 512b1 (the first connection portion) of the internal flow passage 512b opens to the groove portion 511b at a position away from the ridge portion R1 in the Z-axis direction. The other end 512b2 (the second connection portion) of the internal flow passage 512b opens to the groove portion 513b at a position away from the ridge portion R1 in the X-axis direction.

[0104] In other words, the internal flow passage 512b is a path that extends in the holder body 510 and bypasses the ridge portion R1 at the same time, and is configured to connect the upstream portion and the downstream portion of the air flow passage 57b to each other. It should be noted that the end portion 511b1 ( Figure 7C ) of the groove portion 511b on the side closer to the ridge portion R1 is provided at a position away from the ridge portion R1 in the Z-axis direction. The end portion 513b1 ( Figure 7C ) of the groove portion 513b on the side closer to the ridge portion R1 is provided at a position away from the ridge portion R1 in the X-axis direction. That is to say, both the groove portions 511b and 513b are formed so as not to reach the ridge portion R1.

[0105] In this embodiment, the two air flow passages 57a and 57b are defined by a single holder body 510, a connecting member 52a, and a bottom cover 53. Thus, a plurality of flow passages for conveying toner by using air can be realized with a simple structure.

[0106] In other words, the developing container 3Y (accommodating portion) is set as the first accommodating portion, the cartridge 430Y (replenishing container) is set as the first replenishing container, the air flow passage 57a (flow path) is set as the first flow path, and the internal flow passage 512a is set as the first internal flow passage. In this case, the image forming unit 1A includes another developing container 3M (second accommodating portion) for accommodating toner. The cartridge holder 51 (flow passage forming portion) forms an air flow passage 57b (second flow passage) through which air for replenishing toner from a cartridge 430M (second replenishing container) different from the cartridge 430Y to the developing container 3M (second accommodating portion) flows. One of the flat surface portion 51f (first surface) and the flat surface portion 52a1 (third surface) is provided with a groove portion 511b (another first groove portion) that is recessed in a direction away from the other in the first direction. The groove portion 511b is covered by the holder body 510 (first member) or the connecting member 52a (second member) including the other of the flat surface portion 51f (first surface) and the flat surface portion 52a1 (third surface), thereby forming a part of the air flow passage 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 portion 513b (another second groove portion) that is recessed in a direction away from the other in the second direction. The groove portion 513b is covered by the holder body 510 (first member) or the bottom cover 53 (third member) including the other of the lower surface portion 51b (second surface) and the upper surface portion 53b (fourth surface), thereby forming another part of the air flow passage 57b (second flow path). The holder body 510 (first member) includes an internal flow passage 512b that is formed inside the holder body 510 and leads to the said part and the said another part of the air flow passage 57b (second flow path) at positions away from the ridge portion R1, respectively. Thus, multiple flow paths can be realized with a simple structure.

[0107] 3. Air supply paths of cartridges 430C and 430K

[0108] Except for using the connecting member 52d instead of the connecting member 52a, the air supply paths of the cartridges 430C and 430K are substantially the same as those of the cartridges 430Y and 430M.

[0109] As Figure 6A and 6BAs shown, air connection ports 523 and 524 are provided in the connection member 52d. The holder body 510 includes a flat surface portion 51h facing the connection member 52d. The connection member 52d includes a flat surface portion 52d1 facing the holder body 510. In the present embodiment, the connection member 52d is joined to the holder body 510 by joining the flat surface portion 51h and 52d1 together using an adhesive. The flat surface portion 51h of the holder body 510 and the flat surface portion 52d1 of the connection member 52d are substantially parallel surfaces. The flat surface portions 51h and 52d1 of the present embodiment extend in a direction intersecting the X-axis direction. The flat surface portion 51h of the holder body 510 is the surface facing one side (-X side) in the X-axis direction, and the flat surface portion 52d1 of the connection member 52d is the surface facing the other side (+X side) in the X-axis direction.

[0110] The flat surface portion 51h of the holder body 510 has groove portions 511c and 511d. When the holder body 510 and the connection member 52d are joined together, the groove portions 511c and 511d are covered by the flat surface portion 52d1 of the connection member 52d. Thereby, the upstream portions (the first part of the flow path) of the air flow channels 57c and 57d are formed.

[0111] The groove portions 511c and 511d of the present embodiment extend substantially along the Z-axis direction ( Figure 7A ). It should be noted that the extending direction of the groove portions 511c and 511d can be changed within the in-plane direction of the flat surface portion 51h, and the groove portions 511c and 511d can be bent one or more times within the surface of the flat surface portion 51h.

[0112] In addition, holes 523a and 524a ( Figure 6A ) are provided at positions in the flat surface portion 52d1 of the connection member 52d that are opposite to the ends (upper ends) of the groove portions 511c and 511d. The holes 523a and 524a communicate with the air connection ports 523 and 524 through flow channels formed inside the connection member 52d. When the holder body 510 and the connection member 52d are joined together, the holes 523a and 524a are respectively opposite to the ends of the groove portions 511c and 511d. Thereby, the air connection ports 523 and 524 communicate with the upstream portions of the air flow channels 57c and 57d.

[0113] Groove portions 513c and 513d are provided in the lower surface portion 51b of the holder body 510. When the holder body 510 and the bottom cover 53 are joined together, the groove portions 513c and 513d are covered by the upper surface portion 53b of the bottom cover 53. Thereby, the downstream portions (the second part of the flow path) of the air flow channels 57c and 57d are formed.

[0114] The groove portion 513c of the present embodiment extends along the lower surface portion 51b toward the +X side and the -Y side ( Figure 7B ). The groove portion 513d of the present embodiment extends along the lower surface portion 51b toward the +X side and the -Y side ( Figure 7B ). The extending directions of the groove portions 513c and 513d are different, and the extending direction of the groove portion 513d is closer to the Y-axis direction. It should be noted that the extending directions of the groove portions 513c and 513d can be changed within the in-plane direction of the lower surface portion 51b, and the groove portions 513c and 513d can be bent one or more times within the surface of the lower surface portion 51b.

[0115] In addition, the ends (the ends on the +X side) of the groove portions 513c and 513d communicate with the air discharge ports 514c and 514d respectively through the holes provided in the holder body 510 ( Figure 7C ). Therefore, when the holder body 510 and the bottom cover 53 are joined together, the downstream portions of the air flow channels 57c and 57d communicate with the air discharge ports 514c and 514d respectively.

[0116] As described above, by providing the groove portions 511c, 511d, 513c, and 513d on the two surfaces (the flat surface portion 51h and the lower surface portion 51b) of the holder body 510 respectively, the air flow channels 57c and 57d having a curved shape (which cannot be achieved in a single plane) can be formed.

[0117] In addition, an internal flow channel 512c (through which the groove portions 511c and 513c communicate with each other) and an internal flow channel 512d (through which the groove portions 511d and 513d communicate with each other) are provided in the holder body 510. Both the internal flow channels 512c and 512d are formed in a tunnel shape inside the holder body 510. One ends 512c1 and 512d1 of the internal flow channels 512c and 512d open to the groove portions 511c and 511d respectively at positions away from the ridge portion R2 in the Z-axis direction. The other ends 512c2 and 512d2 of the internal flow channels 512c and 512d open to the groove portions 513c and 513d respectively at positions away from the ridge portion R2 in the X-axis direction.

[0118] In other words, both the internal flow channels 512c and 512d are paths that extend in the holder body 510 and bypass the ridge portion R1 at the same time, and are both configured to connect the upstream portion and the downstream portion of the corresponding one of the air flow channels 57c and 57d to each other. It should be noted that the ends of the groove portions 511c and 511d on the side closer to the ridge portion R2 ( Figure 7Cis provided at a position away from the ridge portion R2 in the Z-axis direction. The ends of the groove portions 513c and 513d on the side closer to the ridge portion R2 ( Figure 7C is provided at a position away from the ridge portion R2 in the X-axis direction. That is, the groove portions 511c, 511d, 513c, and 513d are formed so as not to reach the ridge portion R2.

[0119] The internal flow channels 512c and 512d are each formed in a substantially L shape, and the L shape includes a portion extending substantially in the +X direction from the end of a corresponding one of the groove portions 511c and 511d on the side closer to the ridge portion R2 and a portion extending substantially in the +Z direction from the end of a corresponding one of the groove portions 513c and 513d on the side closer to the ridge portion R2.

[0120] In addition, in the present embodiment, the two air flow channels 57c and 57d are defined by a holder body 510, a connecting member 52d, and a bottom cover 53. Thus, a plurality of flow paths for conveying toner by using air can be realized with a simple structure.

[0121] 4. Overview of the air supply path

[0122] The above-described air flow channels 57a, 57b, 57c, and 57d can realize a path for supplying air from the pump unit 80 to the cartridge 430 in a small space. In addition, as Figure 7A and Figure 7B shown, it is easy to arrange the air discharge ports 514a, 514b, 514c, and 514d at positions offset in any of the X-axis direction, Y-axis direction, and Z-axis direction from the corresponding air connection ports among the air connection ports 521, 522, 523, and 524. That is, by forming flow channels that bend along a plurality of surfaces of the holder body 510, the design freedom of the flow channels can be improved.

[0123] Hereinafter, the advantages of the present embodiment will be described by taking the air flow channel 57a corresponding to the cartridge 430Y as an example.

[0124] In the present embodiment, by providing the groove portion 511a (first groove portion) and the groove portion 513a (second groove portion) in two surfaces (the flat surface portion 51f and the lower surface portion 51b) of the holder body 510, respectively, an air flow channel 57a having a curved shape (which cannot be realized in a single plane) can be formed.

[0125] As an alternative to the configuration in which the air flow passage 57a is provided in the cassette holder 51, a configuration may also be considered in which the air connection port 521 is provided near the air discharge port 514a and the air supply pipe 61 extends to near the air discharge port 514a and is connected to the air connection port 521. However, if the air supply pipe 61 extends to near the air discharge port 514a, the space required for arranging the air supply pipe 61 may be large. Specifically, in order to suppress air leakage, the press-fitting length of the air supply pipe 61 with respect to the air connection port 521 (the protruding amount of the air connection port 521) needs to be long to a certain extent. In addition, when the air supply pipe 61 is bent according to the positional relationship between the air connection port 521 and the pump unit 80, the radius of curvature needs to be large so that the air supply pipe 61 will not be significantly bent. Therefore, when the space near the air discharge port 514a is limited, it may be difficult to extend the air supply pipe 61 to near the air discharge port 514a.

[0126] In addition, as another alternative configuration, it may also be considered to connect the air supply pipe 61 to an L-shaped pipe (elbow pipe) instead of providing the air flow passage 57a in the cassette holder 51. However, if the L-shaped pipe is configured to be press-fitted into the air supply pipe 61 to ensure airtightness, the inner diameter of the L-shaped pipe should be small, which narrows the flow passage, and this causes drawbacks such as a large pressure drop of air.

[0127] According to the present embodiment, even when the space near the air discharge port 514a is small, the air connection port 521 can be provided at a position away from the air discharge port 514a, and the air connection port 521 and the air discharge port 514a can be connected to each other through the air flow passage 57a in the cassette holder 51. The air flow passage 57a is formed by covering and thus sealing the groove portions 511a and 513a provided in the holder body 510 by the connecting member 52a and the bottom cover 53, and thus can be realized in a small space. In addition, the air flow passage 57a can be bent at a sharp angle in a manner that is difficult to achieve with the air supply pipe 61.

[0128] More specifically, in the present embodiment, the cartridge 430Y (supply container) is configured to be attached to the holder body 510 (first member). The cartridge 430Y is attached to the upstream side of the holder body 510 in the attachment direction (substantially -X direction) with respect to the holder body 510. In contrast, the pump unit 80 (air supply section) is provided on the downstream side of the holder body 510 in the attachment direction. Further, 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 attachment direction. Thereby, in the attachment direction, the distance between the pump unit 80 and the air connection port 521 can be reduced, and the distance between the air discharge port 514a and the cartridge 430Y can be reduced. In addition, the air connection port 521 (first opening) and the air discharge port 514a (second opening) provided at separated positions in the attachment direction can be connected to each other through the air flow passage 57a having a high degree of design freedom.

[0129] Further, in the present embodiment, the pump unit 80 is provided above the developing container 3Y (accommodating section). 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 inlet port 430Yb1 (opening) of the cartridge 430Y is provided below the pump unit 80. Further, 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. Thereby, in the vertical direction, the distance between the pump unit 80 and the air connection port 521 can be reduced, and the distance between the air discharge port 514a and the cartridge 430Y can be reduced. In addition, the air connection port 521 (first opening) and the air discharge port 514a (second opening) provided at separated positions in the vertical direction can be connected to each other through the air flow passage 57a having a high degree of design freedom.

[0130] Further, in the present embodiment, the direction (substantially +Z direction) in which the air discharge port 514a (second opening) connected to the cartridge 430Y faces is different from the direction (substantially -X direction) in which the air connection port 521 (first opening) connected to the air supply pipe 61Y (tubular member) faces. Therefore, it is difficult to achieve a path with a sharp bend similar to the air flow passage 57a of the present embodiment by bending the flexible air supply pipe 61Y. In contrast, according to the present embodiment, the air connection port 521 (first opening) and the air discharge port 514a (second opening) having different opening directions can be connected to each other through the air flow passage 57a having a high degree of design freedom.

[0131] In addition, in the present embodiment, the groove portions 511a and 513a provided on the two surfaces (the flat surface portion 51f and the lower surface portion 51b) of the holder body 510 are connected to each other through the internal flow passage 512a formed in the holder body 510. The internal flow passage 512a leads to the upstream portion 57a1 and the downstream portion 57a2 of the air flow passage 57a at positions away from the ridge portion R1 between the two surfaces. Thereby, the possibility of air leakage from the gap generated in the ridge portion R1 can be reduced.

[0132] If the groove portions 511a and 513a are directly connected to each other at the ridge portion R1, the flat surface portion 51f and the lower surface portion 51b of the holder body 510, the flat surface portion 52a1 of the connecting member 52a, and the upper surface portion 53b of the bottom cover 53 are concentrated on the ridge portion R1. At this time, a gap may be generated between the flat surface portion 52a1 of the connecting member 52a and the upper surface portion 53b of the bottom cover 53. That is, in the case where the lower surface portion 51b of the holder body 510 is in close contact with the upper surface portion 53b of the bottom cover 53, due to dimensional errors during the manufacture of the components, positioning errors during joining, etc., a gap may be generated between the flat surface portion 52a1 of the connecting member 52a and the upper surface portion 53b of the bottom cover 53. In the presence of such a gap, air may leak from the air flow passage 57a to the outside of the cartridge holder 51. In order to suppress the occurrence of a gap near the ridge portion R1, it is possible to consider reducing the dimensional errors of the components and improving the accuracy of position adjustment. However, this may lead to an increase in production costs and the amount of work required.

[0133] In contrast, in the present embodiment, the groove portions 511a and 513a do not reach the ridge portion R1, and the groove portions 511a and 513a are connected to each other through the internal flow passage 512a in the holder body 510. Therefore, even if there is a gap between the flat surface portion 52a1 of the connecting member 52a and the upper surface portion 53b of the bottom cover 53 at a position adjacent to the ridge portion R1, air will not leak through this gap. If the gaps between the flat surface portion 51f of the holder body 510 and the flat surface portion 52a1 of the connecting member 52a and between the lower surface portion 51b of the holder body 510 and the upper surface portion 53b of the bottom cover 53 are sealed, the leakage of air to the outside of the cartridge holder 51 can be suppressed.

[0134] It should be noted that in the present embodiment, a gap G1 may exist between the connecting member 52a (the second member) and the bottom cover 53 (the third member) at a position adjacent to the ridge portion R1 ( Figure 7C). Thus, for example, due to the abutment between the bottom cover 53 and the connecting member 52a, 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 can be reduced.

[0135] Air supply from the air discharge port to the cartridge

[0136] The air supply from the air discharge ports 514a, 514b, 514c, and 514d to the respective cartridges 430 will be described. In the following description, any one of the air discharge ports 514a, 514b, 514c, and 514d will be described as the air discharge port 514. As Figure 3B and Figure 5A shown, each air discharge port 514 faces upward (substantially in the +Z direction).

[0137] As Figure 3A and Figure 5A shown, the cartridges 430 respectively include inlet ports 430Yb1, 430Mb1, 430Cb1, and 430Kb1 connected to a corresponding one of the air discharge ports 514. In a state where each cartridge 430 is attached to the cartridge holder 51, the inlet ports 430Yb1, 430Mb1, 430Cb1, and 430Kb1 are all connected to a corresponding one of the air discharge ports 514.

[0138] The air discharged upward from each air discharge port 514 is supplied to the inside of the cartridge 430 through a corresponding one of the inlet ports 430Yb1, 430Mb1, 430Cb1, and 430Kb1. The air supplied to the inside of each cartridge 430 is discharged to the outside together with the toner from the cartridge 430. It should be noted that the internal structure of the cartridge 430 will be described later.

[0139] The toner discharged from the cartridge 430 enters the toner flow channel together with the air through the toner inlet ports 515a, 515b, 515c, and 515d of the cartridge holder 51 ( Figure 3A and Figure 6A ). Then, the toner is discharged through the toner connection ports 525, 526, 527, and 528 ( Figure 4B and Figure 6B ) serving as the toner flow channel outlets.

[0140] The supply tubes 62Y, 62M, 62C, and 62K ( Figure 3B and Figure 4BOne end (the upstream ends 62Yu, 62Mu, 62Cu, and 62Ku) of each of the supply tubes 62Y, 62M, 62C, and 62K is connected to the toner connection ports 525, 526, 527, and 528, respectively. The supply tubes 62Y, 62M, 62C, and 62K are all flexible tubular members (tubes). In the following description, any one of the supply tubes 62Y, 62M, 62C, and 62K will be described as the supply tube 62.

[0141] The toner inlet ports 515a, 515b, 515c, and 515d of the cartridge holder 51 Figure 6A are through-holes provided in the front surface portion of the holder body 510. The front surface portion of the holder body 510 is the surface that faces the rear surface (-X side surface) of each cartridge 430. The toner inlet ports 515a, 515b, 515c, and 515d face in the X-axis direction (i.e., the direction in which the developing units 9Y, 9M, 9C, and 9K are arranged in parallel). The direction in which the toner inlet ports 515a, 515b, 515c, and 515d face intersects the direction in which the air discharge ports 514a, 514b, 514c, and 514d open.

[0142] As Figure 6B shown, the toner connection ports 525, 526, 527, and 528 are provided in the connection members 52a, 52b, 52c, and 52d provided on the rear surface portion of the cartridge holder 51, respectively. The toner connection port 525 communicates with the toner inlet port 515a through the flow channel in the connection member 52a and the flow channel formed between the groove portion in the flat surface portion 51f of the holder body 510 and the flat surface portion 52a1 of the connection member 52a. The toner connection port 526 communicates with the toner inlet port 515b through the flow channel in the connection member 52b. The toner connection port 527 communicates with the toner inlet port 515c through the flow channel in the connection member 52c. The toner connection port 528 communicates with the toner inlet port 515d through the flow channel in the connection member 52d and the flow channel formed between the groove portion in the flat surface portion 51h of the holder body 510 and the flat surface portion 52d1 of the connection member 52d.

[0143] As Figure 7A shown, the toner connection ports 526 and 527, which are located in the central portion in the Y-axis direction among the toner connection ports 525, 526, 527, and 528, face outward in the Y-axis direction and upward in the Z-axis direction. Therefore, the supply tubes 62M and 62C connected to the toner connection ports 526 and 527 can easily pass through the toner connection ports 525 and 528 Figure 4Bextends toward the end position in the Y-axis direction of the space orientation processing unit PK above. It should be noted that the supply pipes 62Y, 62M, 62C, and 62K extend in the X-axis direction through the end position in the Y-axis direction of the processing unit PK so that the supply pipes 62Y, 62M, 62C, and 62K do not block the optical path LK of the laser ( Figure 1 ).

[0144] The other ends (downstream ends) of the supply pipes 62Y, 62M, 62C, and 62K are respectively connected to the developing units 9Y, 9M, 9C, and 9K. The toner discharged from the toner connection ports 525, 526, 527, and 528 is respectively transported to the developing units 9Y, 9M, 9C, and 9K through the supply pipes 62Y, 62M, 62C, and 62K by means of an air flow. Thus, toner is supplied to each developing unit 9.

[0145] The toner inlets connected to the corresponding one of the supply pipes 62 are provided in the upper surface of the developing container 3 that serves as the toner storage part in each developing unit 9. Air (mixed air) including toner is supplied to the developing container 3 through the toner inlet port.

[0146] The image forming unit 50 is preferably configured such that it is easy to operate the processing unit P and the supply pipes 62 for maintenance and replacement of the processing unit P, the supply pipes 62, etc. in case of a failure. Therefore, the image forming unit 50 of the present embodiment is configured to be able to be pulled out from the rear side (BE) to the front side (FE) with respect to the apparatus main body 72 (intermediate transfer belt unit 11).

[0147] Structure of the cartridge

[0148] The structure of each cartridge 430 (toner container, supply container) of the present embodiment will be described with reference to Figures 8A to 10B .

[0149] Each of the cartridges 430Y, 430M, 430C, and 430K has substantially the same structure, and thus the cartridge 430Y will be described below. Figure 8A , Figure 8B , Figure 8C , Figure 8D and Figure 8E are respectively the front view, top view, bottom view, right view, and rear view of the cartridge 430Y. Figure 9A is a cross-sectional view of the cartridge 430Y taken along the line H-H of Figure 8E . Figure 9B is a perspective cross-sectional view of the cartridge 430Y. Figure 9C is Figure 9B exploded perspective view of the cartridge 430Y. Figure 10A is a cross-sectional view of the cartridge 430Y taken along the line G-G of Figure 8B . Figure 10B isFigure 10A Perspective view. It should be noted that the description of the structure of the cartridge 430Y below is based on the state (posture) in which the cartridge 430Y is attached to the cartridge holder 51.

[0150] As Figures 9A to 9C shown, the cartridge 430Y includes a first frame body 430Ya, a second frame body 430Yb, a filter 83Y (first filter, first ventilation member), and a discharge pipe 85Y (first discharge pipe, first passage). Although not shown here, the cartridge 430M similarly includes a first frame body, a second frame body, a filter (second filter, second ventilation member), and a discharge pipe (second discharge pipe, second passage). The cartridge 430C similarly includes a first frame body, a second frame body, a filter (third filter, third ventilation member), and a discharge pipe (third discharge pipe, third passage). The cartridge 430K similarly includes a first frame body, a second frame body, a filter (fourth filter, fourth ventilation member), and a discharge pipe (fourth discharge pipe, fourth passage).

[0151] Both the first frame body 430Ya and the second frame body 430Yb of the present embodiment are members formed of resin, but they may also be formed of paper or the like. As Figure 8E shown, a discharge port 430Ya1 (first discharge port) is provided in the rear surface 4300Ya of the first frame body 430Ya. As Figure 8C shown, an inlet port 430Yb1 (first inlet port, first introduction port) is provided in the bottom surface 4300Yb of the second frame body 430Yb. Preferably, the discharge port 430Ya1 and the inlet port 430Yb1 are provided in a surface of the cartridge 430Y other than the surface that intersects the Y-axis direction (i.e., the arrangement direction of the cartridges 430Y, 430M, 430C, and 430K) (the surface facing the Y-axis direction). Thereby, the gap G (Gym, Gmc, and Gck) between the cartridges 430Y, 430M, 430C, and 430K can become narrower. Thereby, the width of each cartridge 430 can be increased, and thus the capacity for accommodating toner can be increased. It should be noted that the gap Gym is the gap in the Y-axis direction between the cartridge 430Y and the cartridge 430M. The gap Gmc is the gap in the Y-axis direction between the cartridge 430M and the cartridge 430C. The gap Gck is the gap in the Y-axis direction between the cartridge 430C and the cartridge 430K.

[0152] In addition, the discharge port 430Ya1 is provided in the rear surface 4300Ya of the cartridge 430Y (the end surface on the downstream side in the attachment direction of the cartridge 430Y) to face the downstream in the attachment direction. The attachment 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 attaching the cartridge 430Y to the cartridge holder 51, it is easier to engage the discharge port 430Ya1 with the inlet port 429Ya of the cartridge holder 51 so that the discharge port 430Ya1 communicates with the inlet port 429a. Note that the discharge port 430Ya1 may be provided in the bottom surface 4300Yb or the top surface of the cartridge 430Y, or the inlet port 430Yb1 may be provided in the rear surface 4300Ya or the top surface.

[0153] When there is sufficient space in the apparatus main body 72 or the like, the discharge port 430Ya1 and the inlet port 430Yb1 may be provided on a surface intersecting the Y-axis direction. In addition, the cartridge 430M includes a discharge port and an inlet port 430Mb1 (introduction port, Figure 3A ), which are arranged in the same manner as in the cartridge 430Y. The cartridge 430C includes a discharge port and an inlet port 430Cb1 (introduction port, Figure 3A ), which are arranged in the same manner as in the cartridge 430Y. The cartridge 430K includes a discharge port and an inlet port 430Kb1 (introduction port, Figure 3A ), which are arranged in the same manner as in the cartridge 430Y.

[0154] The discharge port 430Ya1 may be provided with a sealing member (sticker or baffle) not shown. In a state where 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 suppress leakage of the toner T accommodated therein to the outside of the cartridge 430Y. When attaching the cartridge 430Y to the cartridge holder 51, the sealing member is removed or moved to open the discharge port 430Ya1.

[0155] Figure 8A The label 430Ys on the front surface of the illustrated cartridge 430Y is provided to display the color of the toner in the cartridge. In addition, the label 430Ys may display instructions on how to attach the cartridge 430Y to the cartridge holder 51, or may display some information about the cartridge 430Y.

[0156] The first frame body 430Ya and the second frame body 430Yb each include a flange portion 430Ya2 and a flange portion 430Yb2. Figure 9A The internal space SPY of the illustrated cartridge 430Y is defined by joining the flange portion 430Ya2 and the flange portion 430Yb2 to each other by ultrasonic welding or the like. Note that the flange portion 430Ya2 and the flange portion 430Yb2 may be joined together by an adhesive or screws.

[0157] The filter 83Y is provided to divide (partition) the internal space SPY of the cartridge 430Y into two chambers, namely a toner chamber 430Yc (the first chamber) and an air chamber 430Yd (the second chamber). That is to say, the air chamber 430Yd is adjacent to the toner chamber 430Yc and the filter 83Y is provided therebetween. Similarly, in each of the other cartridges 430M, 430C, and 430K, the internal space of the cartridge is divided (partitioned) into a toner chamber and an air chamber by a filter. These air chambers are all adjacent to the corresponding toner chambers and the filters are provided therebetween.

[0158] The toner chamber 430Yc is located above the air chamber 430Yd and is aligned with the air chamber 430Yd in the Z-axis direction. That is to say, the attachment attitude of the cartridge 430Y relative to the apparatus main body 72 is an attitude in which the cartridge 430Y is oriented such that the toner chamber 430Yc is located 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 the present embodiment, the inlet port 430Yb1 faces this alignment direction, and the discharge port 430Ya1 faces a direction crossing this alignment direction.

[0159] The toner chamber 430Yc (accommodating space) is configured to accommodate toner T. In the toner chamber 430Yc, the toner T is supported by the filter 83Y.

[0160] The air chamber 430Yd does not accommodate toner. The filter 83Y is constituted by, for example, a porous member formed of resin fibers, and the size and density of the pores therein are set to values that allow air to flow through but inhibit toner from flowing through. That is to say, the filter 83Y is configured to allow air to flow through and inhibit toner from flowing through. As Figures 9A to 10B shown, the outer edge portion 83Ya of the filter 83Y is sandwiched between the flange portion 430Ya2 of the first frame body 430Ya and the flange portion 430Yb2 of the second frame body Yb, and thus the filter 83Y is held by the first frame body 430Ya and the second frame body 430Yb. The filter 83Y is inclined from the outer edge portion 83Ya toward the lowermost portion 83Yb provided below the outer edge portion 83Ya. That is to say, the filter 83Y includes a portion (inclined portion) whose position is lower the closer it is to the lowermost portion 83Yb in the X-axis direction, Y-axis direction, or horizontal direction.

[0161] The lowermost 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. As Figure 9A and Figure 10B shown, the lowermost portion 83Yb is provided at the central portion of the filter 83Y in the X-axis direction and Y-axis direction. As the filter 83Y, a filter formed in a quadrangular pyramid shape with the lowermost portion 83Yb as the vertex is used.

[0162] The toner chamber 430Yc is provided with a discharge pipe 85Y (passage). The discharge pipe 85Y of the present embodiment is a member formed of resin, but it may also be formed of paper, rubber, etc. 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 flow passage through which the toner T accommodated in the toner chamber 430Yc passes when moving toward the discharge port 430Ya1. The discharge pipe 85Y includes a first portion 85Y1 provided with the inlet 85Ya and extending in the Z-axis direction, and a second portion 85Y2 provided with 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 each other (at right angles in the present embodiment).

[0163] The outlet 85Yb of the discharge pipe 85Y is connected to the discharge port 430Ya1 and thus communicates with the discharge port 430Ya1. The inlet 85Ya of the discharge pipe 85Y is arranged to face the lowermost portion 83Yb which is a part of the filter 83Y and has a gap therebetween. The inlet 85Ya is preferably close to the filter 83Y. When the remaining amount of the toner T in the toner chamber 430Yc is small, the toner T fluidized by the air received via the inlet port 430Yb1 moves according to the inclination of the above-mentioned filter 83Y and accumulates in the lowermost portion 83Yb. The toner T that has accumulated in the lowermost portion 83Yb of the filter 83Y enters the inlet 85Ya of the discharge pipe 85Y and is guided to the discharge port 430Ya1 through the discharge pipe 85Y. Thus, even when the remaining amount of the toner in the toner chamber 430Yc accommodated in the cartridge 430Y is small, the toner T can be effectively discharged to the outside of the cartridge 430Y.

[0164] The cartridge 430Y of the present embodiment has a structure for discharging the toner to the outside of the cartridge by air and does not provided a rotating member such as a screw. Therefore, the cartridge can be configured as a simple structure with a small number of components.

[0165] Toner conveying mechanism

[0166] An mechanism for conveying the toner accommodated in the toner chamber 430Yc of the cartridge 430Y to the developing unit 9Y will be described.

[0167] The 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 passage 57a of the cartridge holder 51 from the air discharge port 514a opposite to the cartridge 430Y ( Figure 5B). Discharge. The air discharged from the air discharge port 514a is received by the air chamber 430Yd through the inlet port 430Yb1 of the cartridge 430Y. In this case, the air pressure in the air chamber 430Yd ( Figure 9A ) increases, and the air flows from the air chamber 430Yd into the toner chamber 430Yc through the filter 83Y. The air that has flowed into the toner chamber 430Yc enters the gaps between the particles of the toner T, and thus fluidizes the toner T. The toner T mixed with air and thus fluidized is moved from the inlet 85Ya to the outlet 85Yb in the discharge pipe 85Y by the air received by the air chamber 430Yd through the inlet port 430Yb1, and is discharged to the outside of the cartridge 430Y from the discharge port 430Ya1.

[0168] By providing the air chamber 430Yd with high airtightness between the ejection port of the pump unit 80 and the filter 83Y, the air ejected from the ejection port efficiently flows toward the filter 83Y without being scattered to the outside of the cartridge 430Y. For example, when the toner T in the toner chamber 430Yc is likely to agglomerate (for example, when it receives vibration or the cartridge 430Y has been placed for a long time), the pressure required to allow air to flow into the cartridge 430Y through the filter 83Y may be high. Similarly, in this case, by continuously supplying air from the pump unit 80 to the air chamber 430Yd to increase the pressure (air pressure) in the air chamber 430Yd, air can also be supplied to the toner chamber 430Yc through the filter 83Y. In addition, by providing the air chamber 430Yd, the toner can be discharged from the cartridge 430Y even when the air supply amount of the pump unit 80 is relatively small. That is, as long as the pump unit 80 has the performance of generating a high enough pressure to continuously supply air to the air chamber 430Yd so as to reach a pressure sufficient to allow air to enter the toner chamber 430Yc through the filter 83Y, there are no particular requirements for its ejection speed and ejection amount. Therefore, a small-sized pump unit 80 can be adopted, which contributes to the miniaturization of the device.

[0169] The toner T discharged from the discharge port 430Ya1 of the cartridge 430Y enters the supply pipe 62Y from the upstream end 62Yu of the supply pipe 62Y through the toner inlet port 515a of the cartridge holder 51, as Figure 4B shown. The toner T that has entered the supply pipe 62Y from the upstream end 62Yu is moved to the downstream end of the supply pipe 62Y by the air that flows into the supply pipe 62Y together with the toner T.

[0170] In order to improve the exhaust performance of the developing unit 9Y, an exhaust filter portion PYf is provided on the upper surface of the developing unit 9Y, as shown in FIG. 3. The exhaust filter portion PYf is a portion where through holes are provided in the frame body constituting the developing unit 9Y and a filter formed of non-woven fabric or the like is pasted to cover the through holes. The toner T that has flowed into 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 through the exhaust filter portion PYf. Thereby, an increase in the internal pressure in the developing unit 9Y is suppressed, and the toner T and air can more 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 similarly provided with exhaust filter portions PMf, PCf, and PKf, respectively.

[0171] In the present embodiment, the exhaust filter portion PYf is provided on a part of the upper surface of the developing unit 9Y on the downstream side in the Y-axis direction in the toner inflow direction (+Y direction). The exhaust filter portion PYf may be provided on the side surface of the developing unit 9Y instead of on the upper surface of the developing unit 9Y.

[0172] The toner supplied to the inside of the developing unit 9Y (developing container 3Y) is Figure 5B stirred evenly by the stirring members SY1 and SY2 shown. When the downstream end of the supply pipe 62Y is connected to one end in the Y-axis direction of the developing unit 9Y, both the stirring members SY1 and SY2 can be screws that convey the toner in the direction from the one end of the developing unit 9Y toward the other end in the Y-axis direction (+Y direction). In addition, according to the stirring efficiency of the toner T required in the developing unit 9Y, the number of stirring members may be one, three, or more. The other developing units 9M, 9C, and 9K are similarly provided with stirring members SM1, SM2, SC1, SC2, SK1, and SK2, respectively.

[0173] As in the case of the supply pipe 62 of the present embodiment, in a configuration where the direction of the conveyance path changes midway or a configuration where the conveyance path is different for each color, it is preferable to use air as the conveyance medium for conveying the toner. In this case, compared with the case of using a screw or the like as the conveyance medium, the design freedom of the conveyance path is improved, and since there is no need for a conveyance member, the number of components can be reduced.

[0174] In each processing unit P, the developing unit 9 can be configured to be movable within the apparatus main body. For example, the developing unit 9 can be configured to be swingable relative to the drum unit 8 or pressed against the drum unit 8. In this case, each supply pipe 62 is preferably formed of a stretchable flexible material (bendable material). Thereby, it is possible to suppress the case where each supply pipe 62 hinders the operation of the developing unit 9, and it is possible to suppress an increase in components for corresponding to the operation of the developing unit 9.

[0175] Second Embodiment

[0176] will be referred to Figure 11 to describe the cassette holder 51 (flow channel forming portion) according to the second embodiment. In the following description, unless otherwise specified, it is assumed that elements denoted by the same reference numerals as those in the first embodiment have substantially the same configurations and functions as the elements described in the first embodiment, and parts different from the first embodiment will be mainly described.

[0177] Figure 11 is a cross-sectional view of the cassette holder 51 according to the second embodiment and corresponds to that of the first embodiment Figure 7C . The second embodiment is different from the first embodiment in that a groove portion 529 serving as the first groove portion is provided in the flat surface portion 52a1 (the third surface of the second member) of the connecting member 52a. Further, the second embodiment is different from the first embodiment in that a groove portion 531a serving as the second groove portion is provided in the upper surface portion 53b (the fourth surface of the third member) of the bottom cover 53. Other elements in the configuration of the cassette holder 51 are substantially the same as those in the first embodiment.

[0178] When the holder main body 510 and the connecting member 52a are engaged, the groove portion 529 is covered by the flat surface portion 51f (the first surface) of the holder main body 510. Thereby, an upstream portion 57a1 (the first part of the flow channel) of the air flow channel 57a is formed. When the holder main body 510 and the bottom cover 53 are engaged, the groove portion 531a is covered by the lower surface portion 51b of the holder main body 510. Thereby, a downstream portion 57a2 (the second part of the flow channel) of the air flow channel 57a is formed.

[0179] As described above, by providing the groove portions 529 and 531a in the surfaces (the flat surface portion 52a1 and the upper surface portion 53b) of the other members facing the two surfaces of the holder main body 510, it is possible to form the air flow channel 57a having a curved shape (which cannot be achieved in one plane). That is, according to the second embodiment, the design freedom of the flow channel can be improved similarly to the first embodiment.

[0180] In addition, the holder body 510 is provided with an internal flow channel 512a, and the groove portion 529 and the groove portion 531a communicate with each other through the internal flow channel 512a. The internal flow channel 512a is formed inside the holder body 510. One end of the internal flow channel 512a opens to the region of the flat surface portion 51f opposite to 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 channel 512a opens to the region of the lower surface portion 51b opposite to the groove portion 531a at a position away from the ridge portion R1 in the X-axis direction.

[0181] In other words, the upstream portion 57a1 (the first part of the flow channel) and the downstream portion 57a2 (the second part of the flow channel) of the air flow channel 57a are connected to each other through the internal flow channel 512a formed inside the holder body 510. The internal flow channel 512a leads to the upstream portion 57a1 and the downstream portion 57a2 of the air flow channel 57a at positions away from the ridge portion R1 between the two surfaces. Thus, similar to the first embodiment, the possibility of air leakage from the gap generated at the ridge portion R1 can be reduced.

[0182] Third Embodiment

[0183] will be described with reference to Figure 12 the cassette holder 51 (flow channel forming portion) according to the third embodiment. In the following description, unless otherwise specified, it is assumed that the elements denoted by the same reference numerals as those in the first embodiment have substantially the same configurations and functions as the elements described in the first embodiment, and the parts different from the first embodiment will be mainly described.

[0184] Figure 12 is a cross-sectional view of the cassette holder 51 according to the third embodiment and corresponds to that of the first embodiment Figure 7C . The difference between the third embodiment and the first embodiment is that, in addition to the groove portion 511a serving as the first groove portion, a groove portion 529 serving as a third groove portion, which together with the groove portion 511a constitutes a part of the air flow channel 57a, is provided in the flat surface portion 52a1 (the third surface of the second member) of the connecting member 52a. Further, the difference between the third embodiment and the first embodiment is that, in addition to the groove portion 513a serving as the second groove portion, a groove portion 531a serving as a fourth groove portion, which together with the groove portion 513a constitutes a part of the air flow channel 57a, is provided in the upper surface portion 53b (the fourth surface of the third member) of the bottom cover 53.

[0185] When the holder body 510 and the connecting member 52a are joined together, the groove portion 511a faces the groove portion 529. Thus, the upstream portion 57a1 (the first part of the flow channel) of the air flow channel 57a is formed. When the holder body 510 and the bottom cover 53 are joined together, the groove portion 513a faces the groove portion 531a. Thus, the downstream portion 57a2 (the second part of the flow channel) of the air flow channel 57a is formed.

[0186] As described above, by providing the groove portions 511a, 513a, 529, and 531a on two surfaces of the holder body 510 and on the surfaces of other members facing these two surfaces, an air flow channel 57a having a curved shape (which cannot be achieved in a single plane) can be formed. That is, according to the third embodiment, the design freedom of the flow channel can be improved similarly to the first embodiment.

[0187] In addition, the holder body 510 is provided with an internal flow channel 512a, and the groove portion 511a and the groove portion 513a communicate with each other through the internal flow channel 512a. The internal flow channel 512a is formed inside the holder body 510. One end of the internal flow channel 512a opens to the groove portion 511a at a position away from the ridge portion R1 in the Z-axis direction. The other end of the internal flow channel 512a opens to the groove portion 513a at a position away from the ridge portion R1 in the X-axis direction.

[0188] In other words, the upstream portion 57a1 (the first part of the flow channel) and the downstream portion 57a2 (the second part of the flow channel) of the air flow channel 57a are connected to each other through the internal flow channel 512a formed inside the holder body 510. The internal flow channel 512a leads to the upstream portion 57a1 and the downstream portion 57a2 of the air flow channel 57a at positions away from the ridge portion R1 between the two surfaces. Thus, similarly to the first embodiment, the possibility of air leakage from the gap generated at the ridge portion R1 can be reduced.

[0189] In the present embodiment, since the upstream portion 57a1 of the air flow channel 57a is defined by two groove portions 511a and 529 facing each other, the cross-sectional area of the flow channel can be increased compared to the first and second embodiments, and thus the pressure loss can be reduced. In addition, in the present embodiment, since the downstream portion 57a2 of the air flow channel 57a is defined by two groove portions 513a and 531a facing each other, the cross-sectional area of the flow channel can be increased compared to the first and second embodiments, and thus the pressure loss can be reduced. Therefore, even when a smaller air pump is used, air can be used for toner replenishment, and thus the device can be miniaturized.

[0190] Other embodiments

[0191] In the above-described embodiments, an example has been 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 to the connecting members 52a and 52d. Further, in the embodiment, an example has been 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 to the bottom cover 53. The configuration is not limited thereto, and the gap can be sealed by bringing the cartridge holder 51 into contact with the connecting members 52a and 52d when there is a sealing member (first sealing member) between the flat surface portion 51f and the flat surface portions 52a1 and 52d1. Further, the gap can be sealed by bringing the cartridge holder 51 into contact with the bottom cover 53 when there is a sealing member (second sealing member) between the lower surface portion 51b and the upper surface portion 53b. In this case, the joining method is not limited to bonding, as long as the members can be joined together in a state where the sealing member is compressed. For example, the joining can be performed by screwing or snap fitting.

[0192] The sealing member is a sheet-like or ring-like member formed of an elastic material such as rubber and having open pores. As a specific example, when viewed in the X-axis direction, one sealing member is provided so as to surround the entire periphery of each of the groove portions 511a and 511b. When viewed in the X-axis direction, another sealing member is provided so as to surround the entire periphery of each of the groove portions 511c and 511d. When viewed in the Z-axis direction, another sealing member is provided so as to surround the entire periphery of each of the groove portions 513a, 513b, 513c, and 513d.

[0193] Further, in the above-described embodiments, an example of the configuration of the flow path in which air mainly flows from the pump unit 80 to the cartridge 430 has been described. The configuration is not limited thereto, and the configuration of the flow path described in each of the embodiments can be applied to a flow path in which air including toner flows from the cartridge 430 toward the developing container 3.

[0194] According to the present invention, the design freedom of the flow path can be improved, and an image forming apparatus capable of suppressing a decrease in the airtightness of the flow path can be provided.

[0195] Although the present invention has been described with reference to exemplary embodiments, it should be understood that the present invention is not limited to the disclosed exemplary embodiments. The scope of the appended claims should be accorded the broadest interpretation so as to cover all such modifications as well as equivalent structures and functions.

Claims

1. An image forming device, comprising: an air supply portion configured to supply air for conveying toner; as well as a flow channel forming portion in which a first flow channel, a second flow channel, and a third flow channel are formed so that air supplied by the air supply portion flows through the first flow channel, the second flow channel, and the third flow channel in sequence, wherein the flow channel forming portion includes a first component having a first surface and a second surface, a second component having a third surface, and a third component having a fourth surface, the first surface and the second surface intersecting each other and having a ridge therebetween, wherein the first flow channel is formed in a gap between the first surface and the third surface, wherein the third flow channel is formed in a gap between the second surface and the fourth surface, wherein at least a portion of the second flow passage is a tunnel passing through an interior of the first component, and A first connection portion connecting the first flow channel and the second flow channel to each other and a second connection portion connecting the second flow channel and the third flow channel to each other are provided at a position away from the ridge.

2. The image forming apparatus according to claim 1, wherein the first component comprises a first recessed portion provided in the first surface, and The first groove portion is covered by the third surface of the second component, thereby forming the first flow channel.

3. The image forming apparatus according to claim 1, wherein the first component includes a second recessed portion provided in the second surface, and The second groove portion is covered by the fourth surface of the third component, thereby forming the third flow channel.

4. The image forming apparatus according to claim 1, wherein the second component comprises a first groove portion provided in the third surface, and The first groove portion is covered by the first surface of the first component, thereby forming the first flow channel.

5. The image forming apparatus according to claim 1, wherein the third component comprises a second groove portion provided in the fourth surface, and The second groove portion is covered by the second surface of the first component, thereby forming the third flow channel.

6. The image forming apparatus according to claim 1, wherein the first component comprises a first groove portion provided in the first surface, wherein the second component comprises a third recessed portion provided in the third surface, and The first groove portion and the third groove portion are opposite to each other, thereby forming the first flow channel.

7. The image forming apparatus according to claim 1, wherein the first component comprises a second groove portion provided in the second surface, wherein the third component comprises a fourth recessed portion provided in the fourth surface, and The second groove portion and the fourth groove portion are opposite to each other, thereby forming the third flow channel.

8. The image forming apparatus according to any one of claims 1 to 7, wherein the first flow channel and the ridge are separated by an area where the first surface and the third surface abut each other, and The third flow channel and the ridge are separated by a region where the second surface and the fourth surface abut each other.

9. The image forming apparatus according to any one of claims 1 to 7, A gap is provided between the second component and the third component at a position adjacent to the ridge.

10. The image forming apparatus according to any one of claims 1 to 7, wherein at least a portion of the first flow channel extends in a direction intersecting the second surface, and At least a portion of the second flow channel extends in a direction intersecting the first surface.

11. The image forming apparatus according to any one of claims 1 to 7, further comprising: A replenishing container, wherein the replenishing container is provided with a receiving space for receiving toner; as well as an apparatus body to which the replenishing container is attachable and detachable, and the apparatus body includes a housing portion configured to house the toner supplied from the replenishing container, wherein the flow channel forming portion is disposed in the device body, and The first flow channel, the second flow channel, and the third flow channel constitute a flow path, and the air supplied from the air supply portion flows toward the supply container through the flow path.

12. The image forming apparatus according to claim 11, The flow passage forming portion includes a first opening portion for receiving air supplied from the air supply portion, and a second opening portion configured to be connected to an opening portion provided in the replenishment container to draw air from the air supply portion.

13. The image forming apparatus according to claim 12, wherein the replenishing container is attached to the first component in an attachment direction, wherein the air supply is located downstream of the first component in the attachment direction, and The second opening is located upstream of the first opening in the attachment direction.

14. The image forming apparatus according to claim 12, wherein the air supply portion is arranged above the accommodation portion, The position of the replenishing container in the vertical direction overlaps with the position of the accommodating portion in the vertical direction. wherein the opening of the supply container is arranged below the air supply portion, and The second opening is located below the first opening.

15. The image forming apparatus according to claim 12, further comprising: a flexible tubular member having one end connected to the air supply portion and the other end connected to the first opening portion, The opening direction of the first opening is different from the opening direction of the second opening.

16. The image forming apparatus according to any one of claims 1 to 7, wherein the flow channel forming portion is formed so that the air supplied from the air supply portion flows through a fourth flow channel, a fifth flow channel, and a sixth flow channel in sequence, and the fourth flow channel, the fifth flow channel, and the sixth flow channel are flow channels independent of the first flow channel, the second flow channel, and the third flow channel, wherein the fourth flow channel is formed in a gap between the first surface and the third surface, wherein the sixth flow channel is formed in a gap between the second surface and the fourth surface, wherein at least a portion of the fifth flow channel is a tunnel passing through an interior of the first component, and wherein a connecting portion connecting the fourth flow channel and the fifth flow channel to each other and a connecting portion connecting the fifth flow channel and the sixth flow channel to each other are provided at a position away from the ridge portion.

17. The image forming apparatus according to any one of claims 1 to 7, wherein the first surface and the third surface are bonded together, and The second surface and the fourth surface are bonded together.

18. The image forming apparatus according to any one of claims 1 to 7, further comprising: a first sealing member sandwiched between the first surface and the third surface; as well as A second sealing member is sandwiched between the second surface and the fourth surface.

19. The image forming apparatus according to any one of claims 1 to 7, The air supply part is an air pump.

Images