Image forming apparatus, toner container, and developing apparatus

Abstract

An image forming apparatus includes a photosensitive drum, a toner storage portion, a developing roller including a toner bearing portion, and a cyclonic separation portion including an inlet, a first discharge port communicating with an interior of the toner storage portion, and a second discharge port communicating with an exterior of the toner storage portion. The cyclonic separation portion includes a tapered portion formed in a frustoconical shape having a radius that decreases as the frustoconical shape extends downward. The first discharge port is provided at a lower end portion of the tapered portion. At least a portion of the tapered portion protrudes downward with respect to an upper surface of an interior of the toner storage portion. The present disclosure also relates to a toner container and a developing device.

Description

Technical Field

[0001] The present invention relates to an image forming apparatus for forming an image on a recording material, a toner container for accommodating toner, and a developing device used in the image forming apparatus. Background Art

[0002] In an electrophotographic image forming apparatus, since the toner stored in the toner storage portion (i.e., developer container) of a developing device is consumed when an image is formed, toner is supplied to the toner storage portion from a toner container containing the toner for supply. Japanese Patent Application Laid-Open No. 2000-081778 describes a configuration in which toner is conveyed from the toner container to the developing device by an air flow generated by an air pump.

[0003] In the configuration described in Japanese Patent Application Laid-Open No. 2000-081778, a filter that exhausts air is provided on a path along which air containing toner flows toward a developing device. Summary of the invention

[0004] According to one aspect of the present invention, an image forming device includes: a photosensitive drum; a toner storage portion configured to store toner, to which toner is supplied by using air; a developing roller configured to rotate around a rotation axis, the developing roller including a toner carrying portion configured to carry the toner stored in the toner storage portion and supply the toner to the photosensitive drum; and a cyclone separation portion, the cyclone separation portion including an inlet, a first discharge port communicating with the inside of the toner storage portion, and a second discharge port communicating with the outside of the toner storage portion, the cyclone separation portion being configured to receive the toner stored in the toner storage portion through the inlet The cyclone separation portion collects air mixed with toner, separates the toner and the air from each other, discharges the toner separated from the air through a first discharge port, and discharges the air separated from the toner through a second discharge port, wherein the cyclone separation portion is disposed on an upper surface portion of a toner storage portion, wherein the cyclone separation portion includes a conical portion formed in a truncated cone shape, a radius of the truncated cone shape decreasing as the truncated cone shape extends downward, wherein the first discharge port is disposed at a lower end portion of the conical portion, and wherein at least a portion of the conical portion protrudes downward relative to an upper surface of an interior of the toner storage portion.

[0005] According to another aspect of the present invention, a colorant container includes: (i) a container constituting a colorant accommodating space, wherein the colorant accommodating space is configured to accommodate colorant; and (ii) a cyclone separation portion, wherein the cyclone separation portion (ii-i) includes a conical portion and (ii-ii) is configured to (ii-ii-i) receive air with colorant, (ii-ii-ii) separate air and colorant, (ii-ii-iii) discharge the colorant separated from the air into the colorant accommodating space, and (ii-ii-iv) discharge the air separated from the colorant to the outside of the container, wherein when the colorant container is oriented in a direction in which the central axis of the conical portion extends in the direction of gravity and the inner diameter of the conical portion decreases in the direction of gravity, at least a portion of the conical portion protrudes downward relative to the upper surface of the interior of the container constituting the colorant accommodating space.

[0006] According to another aspect of the present invention, a developing device includes: (i) a container constituting a colorant accommodating space, wherein the colorant accommodating space is configured to accommodate colorant; (ii) a developing roller, wherein the developing roller (ii-i) includes a colorant carrying portion for carrying the colorant accommodated in the colorant accommodating space and (ii-ii) is configured to rotate around a rotation axis; and (iii) a cyclone separation portion configured to separate the colorant and air, wherein the cyclone separation portion includes: (iii-i) an air inlet for receiving air carrying the colorant so that it flows into the cyclone separation portion; (iii-ii) a first discharge port, through which the colorant separated from the air is discharged from the cyclone separation portion into the colorant accommodating space, the first discharge port being arranged in a container area between two end portions of the colorant carrying portion of the developing roller in the direction of the rotation axis; and (iii-iii) a second discharge port, through which the air separated from the colorant is discharged from the cyclone separation portion to the outside of the container.

[0007] According to another aspect of the present invention, an image forming device includes: a photosensitive drum; a colorant storage portion configured to store colorant, the colorant being supplied to the colorant storage portion by using air; a developing roller configured to rotate around a rotation axis, the developing roller including a colorant carrying portion, the colorant carrying portion configured to carry the colorant stored in the colorant storage portion and to supply the colorant carried by the colorant carrying portion to the photosensitive drum; and a cyclone separation portion, the cyclone separation portion including an inlet, a first discharge port connected to the inside of the colorant storage portion, and a second discharge port connected to the outside of the colorant storage portion, the cyclone separation portion being configured to receive air mixed with the colorant through the inlet, separate the colorant and the air from each other, discharge the toner separated from the air through the first discharge port, and discharge the air separated from the toner through the second discharge port, wherein in the direction of the rotation axis, the first discharge port is provided between the positions of the two end portions of the colorant carrying portion along the direction of the rotation axis.

[0008] Further features of the present invention will become apparent from the following description of exemplary embodiments with reference to the attached drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Figure 1 is a schematic diagram of the image forming apparatus of the first embodiment.

[0010] Figure 2A is a perspective view of the image forming apparatus of the first embodiment.

[0011] Figure 2B is a perspective view of the image forming apparatus of the first embodiment.

[0012] Figure 2C is a perspective view of the image forming apparatus of the first embodiment.

[0013] Figure 3A is a perspective view of the image forming unit of the first embodiment.

[0014] Figure 3B is a perspective view of the image forming unit of the first embodiment.

[0015] Figure 4A is a top view of the image forming unit of the first embodiment.

[0016] Figure 4B is a top view of the image forming unit of the first embodiment.

[0017] Figure 5A is a sectional view of the image forming unit of the first embodiment.

[0018] Figure 5B is a sectional view of the image forming unit of the first embodiment.

[0019] Figure 6 1 is a diagram showing a state in which the image forming unit of the first embodiment is pulled out.

[0020] Fig. 7A is a front view of the box of the first embodiment.

[0021] Figure 7B is a top view of the box of the first embodiment.

[0022] Figure 7C It is a bottom view of the box of the first embodiment.

[0023] Fig.7D is a side view of the box of the first embodiment.

[0024] Fig. 7E is a rear view of the box of the first embodiment.

[0025] Fig. 8A is a sectional view of the cartridge of the first embodiment.

[0026] Figure 8B is a perspective view of the cartridge of the first embodiment.

[0027] Figure 8C is an exploded perspective view of the cartridge of the first embodiment.

[0028] Fig. 9A is a sectional view of the cartridge of the first embodiment.

[0029] Fig. 9B is a perspective view of a section of the cartridge of the first embodiment.

[0030] Fig. 10A is a front view of the cyclone separator of the first embodiment.

[0031] Fig. 10B FIG. 1 is a top view of the cyclone separator of the first embodiment.

[0032] Fig. 10C It is a bottom view of the cyclone separator of the first embodiment.

[0033] Fig. 10D It is a left side view of the cyclone separator of the first embodiment.

[0034] Fig.10E It is a right side view of the cyclone separator of the first embodiment.

[0035] Fig.11A is a cross-sectional view of the cyclone separator of the first embodiment.

[0036] Fig. 11B is an exploded perspective view of the cyclone separator of the first embodiment.

[0037] Fig. 11C is a cross-sectional view of the cyclone separator of the first embodiment.

[0038] Fig.12 is a perspective view of an image forming unit of a modification.

[0039] Fig.13 is a sectional view of the developing unit of the first embodiment.

[0040] Fig.14 is a perspective view of an image forming unit of the second embodiment.

[0041] Fig.15 is a top view of the image forming unit of the second embodiment.

[0042] Fig.16A is a sectional view of a developing unit of the second embodiment.

[0043] Fig. 16B is a sectional view of a developing unit of the second embodiment. DETAILED DESCRIPTION

[0044] Some embodiments of the present disclosure will be described below with reference to the accompanying drawings.In the following description, the X direction, the Y direction, and the Z direction are preferably orthogonal to each other.

[0045] First embodiment

[0046] Will refer to Figure 1 An overview of the image forming apparatus 1 of the first embodiment is described. Figure 1 A cross section of the image forming device 1 taken along a plane perpendicular to the main scanning direction (i.e., the direction of the rotation axis of the photosensitive drum 4) is shown. The image forming device 1 of the present embodiment is a full-color printer, which can form a full-color image on a recording material S by using four colors of toner as a developer. The recording material (recording medium) S may be any one of various sheets having different sizes and materials. For example, the recording material (recording medium) S may be a paper sheet (e.g., a plain paper sheet or a thick paper sheet), a sheet material on which a certain surface treatment has been performed (e.g., a coated paper sheet), a sheet material of a special shape (e.g., an envelope or index paper sheet), a plastic film, or a cloth sheet.

[0047] The image forming apparatus 1 includes processing units PY, PM, PC, and PK (hereinafter referred to as each processing unit P) and an apparatus body 72. It is to be noted that each processing unit P is arranged along a first direction (hereinafter referred to as the X direction), and the colors of the toners stored in the processing units are different from each other. The longitudinal direction of each processing unit P is a second direction (hereinafter referred to as the Y direction) perpendicular to the X direction. The processing units PY, PM, PC, and PK are defined as a first processing unit, a second processing unit, a third processing unit, and a fourth processing unit, respectively.

[0048] Each process unit P includes a process section (i.e., a process unit) for an electrophotographic process. The process section is a unit that operates an image bearing member or a recording material for performing any of the electrophotographic processes: a charging process, an exposure process, a developing process, a transfer process, a cleaning process, and a fixing process. A rotational driving force is transmitted from a driving force output portion of the device body 72 to each process unit P. In addition, a bias voltage (e.g., a charging bias or a developing bias) is supplied to each process unit P from a power supply circuit of the device body 72.

[0049] like Figure 1 As shown, the processing units PY, PM, PC and PK include drum units 8Y, 8M, 8C and 8K (hereinafter referred to as drum units 8), respectively. Each drum unit 8 includes a corresponding one of the photosensitive drums 4Y, 4M, 4C and 4K (hereinafter referred to as photosensitive drums 4), and a corresponding one of the charging rollers 5Y, 5M, 5C and 5K (hereinafter referred to as charging rollers 5). Each charging roller 5 is used as a processing part that operates on the corresponding photosensitive drum 4. Each photosensitive drum 4 is used as an image bearing member that carries a latent image and a toner image. Each photosensitive drum 4 is an electrophotographic photoreceptor in which a photosensitive layer made of an organic photosensitive material or the like is formed on the peripheral portion of a cylindrical substrate. Each photosensitive drum 4 is arranged so that the rotation axis direction of the photosensitive drum 4 is equivalent to the Y direction. The photosensitive drums 4Y, 4M, 4C and 4K are defined as a first photosensitive drum, a second photosensitive drum, a third photosensitive drum and a fourth photosensitive drum, respectively.

[0050] Each processing unit P includes a corresponding one of the developing units 9Y, 9M, 9C and 9K (hereinafter referred to as each developing unit 9). Each developing unit 9 includes a corresponding one of the developing rollers 6Y, 6M, 6C and 6K (hereinafter referred to as each developing roller 6). Each developing roller 6 develops the electrostatic latent image formed on the corresponding photosensitive drum 4. Each developing unit 9 is arranged along the X direction. The developing rollers 6Y, 6M, 6C and 6K are respectively defined as a first developing roller, a second developing roller, a third developing roller and a fourth developing roller. The developing units 9Y, 9M, 9C and 9K are respectively defined as a first developing unit, a second developing unit, a third developing unit and a fourth developing unit.

[0051] Each developing unit 9 includes a corresponding one of developer containers 3Y, 3M, 3C, and 3K (hereinafter referred to as each developer container 3). Each developer container 3 is a toner storage portion that stores toner used by a corresponding developing roller 6 for development. Each developing roller 6 includes an outer peripheral surface of a toner bearing portion that serves as a toner bearing portion that bears the toner stored in the corresponding developer container 3 (i.e., the toner storage portion). Each developing roller 6 is a developer bearing member that develops a latent image formed on a corresponding photosensitive drum 4 (i.e., an image bearing member) into a toner image by using the toner carried by the outer peripheral surface of the developing roller 6. It is to be noted that each developing roller 6 may be a cylindrical member (also referred to as a developing sleeve).

[0052] The developing unit 9Y includes a developer container 3Y (i.e., a first developer container) storing a yellow (Y) toner (i.e., a first toner). In the developing unit 9Y, the yellow toner is supplied to the surface of the photosensitive drum 4Y by the developing roller 6Y carrying the yellow toner. The developing unit 9M includes a developer container 3M (i.e., a second developer container) storing a magenta (M) toner (i.e., a second toner). In the developing unit 9M, the magenta toner is supplied to the surface of the photosensitive drum 4M by the developing roller 6M carrying the magenta toner. The developing unit 9C includes a developer container 3C (i.e., a third developer container) storing a cyan (C) toner (i.e., a third toner). In the developing unit 9C, the cyan toner is supplied to the surface of the photosensitive drum 4C by the developing roller 6C carrying the cyan toner. The developing unit 9K includes a developer container 3K (i.e., a fourth developer container) storing a black (K) toner (i.e., a fourth toner). In the developing unit 9K, the black toner is supplied to the surface of the photosensitive drum 4K by the developing roller 6K that carries the black toner.

[0053] The laser scanner unit LB (i.e., exposure unit) is disposed above each processing unit P (or each photosensitive drum 4) along a third direction (hereinafter referred to as Z direction) intersecting both the X direction and the Y direction. The laser scanner unit LB outputs a laser beam according to image information. Hereinafter, an optical path of the laser beam toward the photosensitive drum 4Y is represented by LY, an optical path of the laser beam toward the photosensitive drum 4M is represented by LM, an optical path of the laser beam toward the photosensitive drum 4C is represented by LC, and an optical path of the laser beam toward the photosensitive drum 4K is represented by LK (hereinafter, each optical path is referred to as each optical path L or optical path L). The laser beam passes through each exposure window 10Y, 10M, 10C, and 10K of the laser scanner unit LB, and scans and exposes the surface of the corresponding photosensitive drum 4. It is to be noted that an LED exposure unit may be used instead of the laser scanner unit LB.

[0054] Preferably, the Z direction is parallel to the vertical direction (i.e., the gravity direction) defined relative to the image forming apparatus 1 placed on a horizontal plane. In addition, unless otherwise specified, the downward direction is a direction of the Z direction (i.e., Figure 1 The downward direction in the Z direction), and the upward direction is the other direction of the Z direction (i.e. Figure 1 in the upward direction).

[0055] Below the process unit P along the Z direction, an intermediate transfer belt unit 11 is provided as a transfer member (i.e., an intermediate transfer unit). The intermediate transfer belt unit 11 includes a transfer belt 12, a drive roller 14, a tension roller 13, and an auxiliary roller 15. The transfer belt 12 has flexibility and is wound around the drive roller 14, the tension roller 13, and the auxiliary roller 15.

[0056] The bottom surface of each photosensitive drum 4 is in contact with the top surface of the transfer belt 12. The contact portion between each photosensitive drum 4 and the transfer belt 12 serves as a corresponding one of the primary transfer sections 30Y, 30M, 30C, and 30K (hereinafter referred to as the primary transfer section 30). Inside the transfer belt 12, each primary transfer roller 16Y, 16M, 16C, and 16K (hereinafter referred to as the transfer roller 16) is provided to face the corresponding photosensitive drum 4.

[0057] The driving roller 14 is pressed by the secondary transfer roller 17 via the transfer belt 12. A contact portion between the transfer belt 12 and the secondary transfer roller 17 serves as a secondary transfer portion 31.

[0058] The feeding unit 18 is disposed below the intermediate transfer belt unit 11 in the Z direction. The feeding unit 18 includes a feeding tray 19 that stores the recording material S stacked on the feeding tray 19 and a feeding roller 20 that picks up and conveys the recording material S from the feeding tray 19 .

[0059] exist Figure 1 , a fixing unit 21 and a discharge roller 22 are provided at an upper portion of the apparatus body 72. The fixing unit 21 fixes the toner image onto the recording material S, and the discharge roller 22 discharges the recording material S on which the toner image is fixed to the discharge tray 23. The discharge roller 22 discharges the recording material S toward the direction along the X direction. Note that, in the present embodiment, the downstream side of the discharge direction in which the recording material S is discharged toward the discharge tray 23 by the discharge roller 22 is defined as the front side or FE side of the image forming apparatus 1, and the upstream side of the discharge direction is defined as the rear side or BE side of the image forming apparatus 1. Furthermore, the right side of the image forming apparatus 1 as viewed from the front side is defined as the right side or RE side of the image forming apparatus 1, and the left side of the image forming apparatus 1 as viewed from the front side is defined as the left side or LE side of the image forming apparatus 1. In the present embodiment, the RE side is one side in the Y direction, and the LE side is the other side in the Y direction opposite to the RE side.

[0060] Image forming operation

[0061] The image forming operation for forming a full-color image is as follows. Each photosensitive drum 4 is rotated at a predetermined speed. Figure 1 The transfer belt 12 rotates counterclockwise along the direction in which the transfer belt 12 and each photosensitive drum 4 rotate together (i.e. Figure 1 The photosensitive drums 4 rotate (in the direction indicated by the arrow C) at a speed corresponding to the rotation speed of each photosensitive drum 4.

[0062] The laser scanner unit LB is also driven. In each process unit P, the charging roller 5 uniformly charges the surface of the corresponding photosensitive drum 4 with a predetermined polarity and potential in synchronization with the driving of the laser scanner unit LB. The laser scanner unit LB scans and exposes the charged surface of each photosensitive drum 4 with a laser beam according to the image signal of the corresponding color, and forms an electrostatic latent image on the surface of the photosensitive drum 4 according to the image signal of the corresponding color. That is, the laser scanner unit LB exposes the photosensitive drum 4Y and the photosensitive drum 4M, and forms a first electrostatic latent image on the photosensitive drum 4Y and a second electrostatic latent image on the photosensitive drum 4M. Similarly, the laser scanner unit LB exposes the photosensitive drum 4C and the photosensitive drum 4K, and forms a third electrostatic latent image on the photosensitive drum 4C and a fourth electrostatic latent image on the photosensitive drum 4K.

[0063] The electrostatic latent image on each photosensitive drum 4 is formed by Figure 1 The corresponding developing roller 6 which rotates clockwise and supplies toner to the photosensitive drum 4 is developed. In the above-mentioned electrophotographic image forming process, a yellow toner image is formed on the photosensitive drum 4Y of the processing unit PY. The yellow toner image is primarily transferred to the transfer belt 12. Similarly, a magenta toner image is formed on the photosensitive drum 4M of the processing unit PM. The magenta toner image is primarily transferred to the transfer belt 12, thereby being superimposed on the yellow toner image formed on the transfer belt 12. Similarly, a cyan toner image is formed on the photosensitive drum 4C of the processing unit PC. The cyan toner image is primarily transferred to the transfer belt 12, thereby being superimposed on the yellow and magenta toner images formed on the transfer belt 12. Similarly, a black toner image is formed on the photosensitive drum 4K of the processing unit PK. The black toner image is primarily transferred onto the transfer belt 12 so as to be superimposed on the yellow, magenta, and cyan toner images formed on the transfer belt 12 .

[0064] In this way, a full-color unfixed toner image of four colors, yellow, magenta, cyan, and black, is formed on the transfer belt 12. On the other hand, the recording material S is separated one by one by the feed roller 20 at a predetermined control timing and fed from the feed tray 19. The recording material S is introduced into the secondary transfer portion 31 at a predetermined control timing. The secondary transfer portion 31 is an abutment portion between the secondary transfer roller 17 and the transfer belt 12. In the process of conveying the recording material S by the secondary transfer portion 31, a toner image formed on the transfer belt 12 and in which the toner images of the four colors are superimposed on each other is transferred to the recording material S. The recording material S to which the toner image has been transferred is heated and pressurized by the fixing unit 21, so that the toner image is fixed to the recording material S. The recording material S on which the toner image is fixed is discharged to the discharge tray 23 by the discharge roller 22.

[0065] box

[0066] The image forming apparatus 1 includes cartridges 430Y, 430M, 430C, and 430K (hereinafter referred to as individual cartridges 430), each of which serves as a supply package that can be attached to and detached from the apparatus body 72. It should be noted that in the present embodiment, the apparatus body 72 is the remaining portion of the image forming apparatus 1 when the cartridges 430Y, 430M, 430C, and 430K are removed from the image forming apparatus 1. The individual cartridges 430 are arranged along the Y direction. That is, the individual cartridges 430 are arranged along a direction that intersects (or intersects at right angles) with the arrangement direction of the individual developing units 9. The cartridges 430Y, 430M, 430C, and 430K are defined as a first cartridge (i.e., a first toner container), a second cartridge (i.e., a second toner container), a third cartridge (i.e., a third toner container), and a fourth cartridge (i.e., a fourth toner container), respectively.

[0067] Figure 2A 1 is a perspective view of the image forming apparatus 1 in a state where the front door 72 b is closed. Figure 2B 7 is a perspective view of the image forming apparatus 1 in a state where the front door 72 b is opened. Figure 2C 4 is a perspective view of the image forming apparatus 1 with the cartridge 430M removed from the cartridge holder 429 in a state where the front door 72 b is open.

[0068] The device body 72 includes a housing 72a and a front door 72b, and the front door 72b serves as an opening and closing member that can be opened and closed relative to the housing 72a. The housing 72a contains each processing unit P, the laser scanner unit LB, the intermediate transfer belt unit 11, the fixing unit 21, etc. Each box 430 is attached to the upper part of the device body 72 at the front side so that the user can operate each box 430 by opening the front door 72b. In other words, each box 430 is provided on the end of the housing 72a on the downstream side of the discharge direction of the discharge roller 22.

[0069] The front door 72b can be in a closed position where the front door 72b closes the opening on the front side of the device body 72 (see Figure 2A ) and an open position (see FIG. 2b) in which the front door 72b opens the opening. Figure 2B As shown in FIG. 1 , if the front door 72 b is moved to the open position, each box 430 is exposed to the outside of the image forming apparatus 1 through the opening. The respective boxes 430 are arranged along the Y direction, and as shown in FIG. Figure 2C As shown, it is attachable to and detachable from the apparatus body 72 in the X direction. In this configuration, toner can be supplied to each processing unit P without separating each processing unit P from the apparatus body 72. Since each cartridge 430 is disposed on the front side of the image forming apparatus 1, the user can operate each cartridge 430 from the front side, as in the case where the user recovers the recording material S discharged to the discharge tray 23. In addition, since the cartridge holder 429 is disposed on the front side of the image forming apparatus 1, the processing unit P is not exposed even after each cartridge 430 is removed (see Figure 2C ). In a state where the front door 72b is closed, each box 430 is accommodated in a space formed in the device body 72 (ie, a space between the housing 72a and the front door 72b).

[0070] like Figure 2A As shown, indicators (i.e., marking portions or display portions) 208Y, 208M, 208C, and 208K (hereinafter referred to as individual indicators 208) of various colors are provided at the front side of the image forming apparatus 1. Each indicator 208 is arranged in association with the corresponding cartridge 430 along the Y direction. Indicator 208Y (i.e., the first indicator) has a yellow color, and indicator 208M (i.e., the second indicator) has a magenta color. Indicator 208C (i.e., the third indicator) has a cyan color, and indicator 208K (i.e., the fourth indicator) has a black color. Each indicator 208 is an LED or a seal, the color of which corresponds to the color of the toner of the corresponding cartridge, and is provided to prevent each cartridge 430 from being erroneously attached to the apparatus body 72. In another case, each indicator 208 may have a function for displaying the remaining amount of toner of the corresponding processing unit P (i.e., the corresponding developing unit 9).

[0071] Image forming unit

[0072] Next, we will refer to Figures 3A to 6 A toner conveying mechanism from each cartridge 430 to the corresponding process unit P is described.

[0073] A unit including each cartridge 430 , each process unit P, and a conveying path described below for conveying toner from each cartridge 430 to the corresponding process unit P is defined as an image forming unit 500 .

[0074] Figure 3A 4 is a perspective view of the image forming unit 500 in a state where the respective cartridges 430 are attached to the image forming unit 500 . Figure 3B 4 is a perspective view of the image forming unit 500 in a state where each cartridge 430 is removed from the image forming unit 500 . Figure 4A It is a plan view of the laser scanner unit LB and the image forming unit 500 . Figure 4B is a top view of the image forming unit 500 . Figure 5A It is along Figure 4A A cross-sectional view taken along line AA of Figure 5B It is along Figure 4A A cross-sectional view taken along line BB.

[0075] like Figure 3A As shown, pump units 80Y, 80M, 80C and 80K (hereinafter referred to as individual pump units 80) are arranged below the box holder 429. Each pump unit 80 is arranged along the Y direction. Pump units 80Y, 80M, 80C and 80K are defined as the first pump unit, the second pump unit, the third pump unit and the fourth pump unit, respectively. Each pump unit 80 is a positive displacement pump, such as a reciprocating pump or a rotary pump. A reciprocating pump performs suction and discharge through a reciprocating component (such as a piston or a plunger); and examples of reciprocating pumps include piston pumps, plunger pumps and diaphragm pumps. A rotary pump performs suction and discharge through the rotation of a component such as a gear or a rotor; and examples of rotary pumps include gear pumps, screw pumps and vane pumps. It should be noted that four pump units can be formed as a single pump unit. In the present embodiment, each pump unit 80 is arranged in the image forming unit 500, but can also be arranged in the corresponding box 430 or the device body 72.

[0076] It should be noted that the air exhausted from each pump unit 80 may not be a gas of the same composition as the atmosphere. For example, the air exhausted from each pump unit 80 may be a gas obtained by removing steam or oxygen from the atmosphere. In another case, each pump unit 80 may exhaust nitrogen supplied from a tank containing liquid nitrogen as air.

[0077] like Figure 3B and Figure 5A As shown, an opening is formed in the portion of the bottom surface of the cartridge holder 429 facing each cartridge 430, and ejection ports 80Ya, 80Ma, 80Ca and 80Ka (hereinafter referred to as each ejection port 80a) are exposed through the opening. The air generated by each pump unit 80 is ejected from the corresponding ejection port 80a. Each ejection port 80a opens in an upward direction.

[0078] The air discharged upward from each ejection port 80a is supplied to the inside of the corresponding box 430 attached to the box holder 429. The air supplied to the inside of each box 430 is discharged from the box 430 together with the toner. That is, the air containing the toner (i.e., the air mixed with the toner, or the mixed fluid containing the air and the toner) is discharged from each box 430. Note that the internal structure of each box 430 will be described later, so it will not be described in detail in this section.

[0079] The air discharged from each cartridge 430 and containing toner passes through Figure 3B A corresponding one of the receiving ports 429Ya, 429Ma, 429Ca and 429Ka formed in the shown box retainer 429 is received by a corresponding one of the supply pipes 444Y, 444M, 444C and 444K. Hereinafter, receiving ports 429Ya, 429Ma, 429Ca and 429Ka are referred to as each receiving port 429a. In addition, supply pipes 444Y, 444M, 444C and 444K are referred to as each supply pipe 444.

[0080] Each supply pipe 444 extends to the corresponding developing unit 9 and is connected to the developing unit 9. Each receiving port 429a is a through hole formed through the surface of the cartridge holder 429 facing the back side of the corresponding cartridge 430. Each receiving port 429a opens toward the X direction (that is, the direction in which each developing unit 9 is arranged). The direction in which each receiving port 429a opens intersects with the direction in which each ejection port 80a opens.

[0081] like Figure 4B As shown, upstream end portions 444Yu, 444Mu, 444Cu, and 444Ku (hereinafter referred to as respective upstream end portions 444u) of the supply pipes 444Y, 444M, 444C, and 444K are provided on the back side of a portion where respective receiving ports 429a are formed in the cartridge holder 429. Each upstream end portion 444u is connected to the cartridge holder 429 in such a manner as to communicate with the corresponding receiving port 429a.

[0082] The toner received from each receiving port 429a is conveyed through the inside of the corresponding supply pipe 444 by the air exhausted from the corresponding box 430. The toner moves from each upstream end 444u of the corresponding supply pipe 444 to a corresponding one of downstream ends 444Yd, 444Md, 444Cd, and 444Kd (hereinafter referred to as each downstream end 444d), and is supplied to the corresponding developing unit 9.

[0083] Each developer container 3 (that is, a storage portion of the corresponding developing unit 9 for storing the toner T) includes a corresponding one of cyclone separators CyY, CyM, CyC, and CyK (hereinafter referred to as each cyclone separator Cy) provided on the upper surface of the developer container 3. Each cyclone separator Cy supplies the toner T to the corresponding developer container 3, while separating air from the air supplied to the developer container 3 and containing the toner, and simultaneously discharges the separated air to the outside of the developer container 3. The developer container 3 and the cyclone separator Cy formed in the developer container 3 constitute a toner storage unit as an example of a toner container. It is to be noted that the internal structure of each cyclone separator Cy will be described below, so it will not be described in detail in this section.

[0084] Each downstream end portion 444d of the corresponding supply pipe 444 is connected to a corresponding cyclone separator Cy formed at the end portion in the Y direction of the corresponding developer container 3. Specifically, the downstream end portion 444Yd of the supply pipe 444Y is connected to the cyclone separator CyY formed at the end portion on the LE side of the developer container 3Y, and the downstream end portion 444Md of the supply pipe 444M is connected to the cyclone separator CyM formed at the end portion on the LE side of the developer container 3M. In addition, the downstream end portion 444Cd of the supply pipe 444C is connected to the cyclone separator CyC formed at the end portion on the RE side of the developer container 3C, and the downstream end portion 444Kd of the supply pipe 444K is connected to the cyclone separator CyK formed at the end portion on the RE side of the developer container 3K.

[0085] Since each supply pipe 444 and the corresponding cyclone separator Cy are connected to each other in this manner, the length of each supply pipe 444 can be shortened, thereby reducing the pressure loss of each supply pipe 444. In addition, since the pressure loss is reduced, a small pump unit can be selected as each pump unit 80, and the image forming unit 500 can be miniaturized.

[0086] Preferably, the image forming unit 500 is configured so that the user can easily operate the process unit P and the supply pipe 444 for performing maintenance or replacement of the process unit P or the supply pipe 444, so as to provide maintenance when a malfunction occurs in the image forming unit 500. For this reason, in the present embodiment, the image forming unit 500 can be pulled out from the BE side (i.e., the rear side) to the FE side (i.e., the front side) relative to the apparatus body 72. In addition, in the present embodiment, the image forming unit 500 can be pulled out from the BE side (i.e., the rear side) to the FE side (i.e., the front side) relative to the intermediate transfer belt unit 11. Figure 6 The image forming unit 500 is shown in a state where the image forming unit 500 is pulled out from the apparatus body 72. Note that the image forming apparatus 1 may have a configuration in which the image forming unit 500 cannot be pulled out.

[0087] Furthermore, it is preferable that the configuration of each cyclone separator Cy allows the user to easily operate the cyclone separator Cy for maintenance. For this reason, in the present embodiment, when the image forming unit 500 is pulled out from the BE side (i.e., the rear side) to the FE side (i.e., the front side) relative to the device body 72, each cyclone separator Cy is exposed to the outside of the device body 72. That is, when the image forming unit 500 is pulled out toward the FE side, each cyclone separator Cy is exposed to the outside of the device body 72 through the opening 72a1 ( Figure 2B ) protrudes toward the FE side (ie, the front side). Note that an opening 72a1 is formed in the end surface 72aF for allowing the user to pull out and insert the image forming unit 500. In addition, in the present embodiment, each cartridge 430 is attached to and detached from the device body 72 through the opening 72a1.

[0088] Box structure

[0089] Next, we will refer to Figure 3A and 7A to 9B The structure of each cartridge 430 of the present embodiment is described. Each cartridge 430 is an example of a toner container.

[0090] like Figure 3A As shown, the width La of box 430K in the Y direction is greater than the width Lb of boxes 430Y, 430M and 430C. Therefore, the volume of box 430K for storing toner is greater than the volume of each box 430Y, 430M and 430C. Usually, the consumption of black toner is greater than the toner of any other color. For this reason, box 430K is allowed to store more black toner than the toner of any other color. As a result, the number of replacements of box 430Y, 430M, 430C and 430K can be easily equalized. It should be noted that in the present embodiment, box 430Y, 430M and 430C have the same width Lb in the Y direction. However, box 430Y, 430M and 430C can have different widths in the Y direction.

[0091] The respective cartridges 430 have the same structure except that the width in the Y direction is different. Therefore, in the following description, the structure of the cartridge 430Y will be described, and the description of the structures of the cartridges 430M, 430C, and 430K will be omitted.

[0092] Fig. 7A This is the front view of the box 430Y. Figure 7B is a top view of the box 430Y, Figure 7C This is a bottom view of box 430Y. Fig.7D is a right side view of the cartridge 430Y, and Fig. 7E It is a rear view of the box 430Y. Fig. 8A It is along Fig. 7EA cross-sectional view taken along line HH. Figure 8B is a perspective view of the cartridge 430Y. Figure 8C is an exploded perspective view of the cartridge 430Y. Fig. 9A It is along Figure 7B A cross-sectional view taken along line GG. Fig. 9B yes Fig. 9A Note that the following description of the structure of the cartridge 430Y will be given with respect to the cartridge 430Y in a state (posture) in which the cartridge 430Y is attached to the cartridge holder 429.

[0093] like FIG. 8A to FIG. 8C As shown, box 430Y includes a first frame 430Ya, a second frame 430Yb, a filter 83Y (i.e., a first filter or a first air-permeable component), and an exhaust pipe 85Y (i.e., a first exhaust pipe or a first path). Although not shown in the figure, similar to box 430Y, box 430M includes a third frame corresponding to the first frame 430Ya and a fourth frame corresponding to the second frame 430Yb. In addition, box 430M includes a filter corresponding to filter 83Y (i.e., a second filter or a second air-permeable component) and an exhaust pipe corresponding to exhaust pipe 85Y (i.e., a second exhaust pipe or a second path). Similarly, box 430C includes a fifth frame corresponding to the first frame 430Ya and a sixth frame corresponding to the second frame 430Yb. In addition, box 430C includes a filter corresponding to filter 83Y (i.e., a third filter or a third air-permeable component) and an exhaust pipe corresponding to exhaust pipe 85Y (i.e., a third exhaust pipe or a third path). Similarly, the box 430K includes a seventh frame corresponding to the first frame 430Ya and an eighth frame corresponding to the second frame 430Yb. In addition, the box 430K includes a filter corresponding to the filter 83Y (i.e., a fourth filter or a fourth air-permeable member) and an exhaust pipe corresponding to the exhaust pipe 85Y (i.e., a fourth exhaust pipe or a fourth path).

[0094] The first frame 430Ya and the second frame 430Yb of the present embodiment are components made of resin. However, the first frame 430Ya and the second frame 430Yb may be made of another material such as paper. Fig. 7E As shown, a discharge port 430Ya1 (ie, a first discharge port) is formed in a rear surface 4300Ya of the first frame 430Ya.

[0095] like Figure 7C As shown, a receiving port 430Yb1 (i.e., a first receiving port or a first inlet) is formed on the bottom surface 4300Yb of the second frame 430Yb. Preferably, the discharge port 430Ya1 and the receiving port 430Yb1 are formed in the surface of the box 430Y except for the surface intersecting with the Y direction (the Y direction is the direction in which the respective boxes 430 are arranged) (which faces the Y direction). In this configuration, it is possible to Figure 3AThe gap Gym between the boxes 430Y and 430M shown, the gap Gmc between the boxes 430M and 430C, and the gap Gck between the boxes 430C and 430K are smaller. As a result, the width La or Lb of each box 430 can be increased, thereby increasing the volume of each box 430 for storing toner. It should be noted that the gap Gym is the gap between the boxes 430Y and 430M in the Y direction. The gap Gmc is the gap between the boxes 430M and 430C along the Y direction. The gap Gck is the gap between the boxes 430C and 430K along the Y direction.

[0096] The discharge port 430Ya1 is formed in the back side 4300Ya of the box 430Y (i.e., the end face of the box 430Y on the downstream side of the attachment direction) so that the discharge port 430Ya1 opens toward the downstream side of the attachment direction. Therefore, when the box 430Y is attached to the box holder 429, the discharge port 430Ya1 can be easily engaged with the receiving port 429Ya of the box holder 429 so that the discharge port 430Ya1 is connected to the receiving port 429Ya. It should be noted that the discharge port 430Ya1 can be formed in the bottom surface 4300Yb or the top surface of the box 430Y, and the receiving port 430Yb1 can be formed in the back side 4300Ya or the top surface. If the device body 72 has enough space, the discharge port 430Ya1 and the receiving port 430Yb1 can also be formed in the surface intersecting with the Y direction. In addition, although not shown in the figure, the box 430M includes a discharge port (i.e., the second discharge port) and a receiving port (i.e., the second receiving port or the second inlet) arranged similarly to the box 430Y. The box 430C includes a discharge port (i.e., the third discharge port) and a receiving port (i.e., the third receiving port or the third inlet) arranged similarly to the box 430Y. The box 430K includes a discharge port (i.e., the fourth discharge port) and a receiving port (i.e., the fourth receiving port or the fourth inlet) arranged similarly to the box 430Y.

[0097] In another case, a sealing member (i.e., a sealing member or a baffle) not shown in the figure may be provided on the discharge port 430Ya1. In this case, the sealing member seals the discharge port 430Ya1 and prevents the toner T stored in the cartridge 430Y from leaking to the outside of the cartridge 430Y in a state where the cartridge 430Y is not attached to the cartridge holder 429 of the apparatus body 72. When the cartridge 430Y is attached to the cartridge holder 429, the discharge port 430Ya1 is opened by removing or moving the sealing member.

[0098] Fig. 7A The label 430Ys of the cartridge 430Y shown disposed on the front side is for indicating the color of the toner stored in the cartridge 430Y. The label 430Ys may be instructions showing how to attach the cartridge 430Y to the cartridge holder 429, or may display some information about the cartridge 430Y.

[0099] like FIG. 8A to FIG. 8C As shown, the first frame 430Ya includes a flange portion 430Ya2, and the second frame 430Yb includes a flange portion 430Yb2. The flange portion 430Ya2 and the flange portion 430Yb2 are welded to each other by using ultrasonic welding, thereby forming a Fig. 8A The inner space SPY of the case 430Y is shown. Note that the flange portion 430Ya2 and the flange portion 430Yb2 may be fixed to each other via an adhesive or screws.

[0100] Filter 83Y is arranged to separate (or divide) the inner space SPY of box 430Y into two chambers: toner chamber 430Yc (i.e., the first chamber) and air chamber 430Yd (i.e., the second chamber). That is, air chamber 430Yd is adjacent to toner chamber 430Yc via filter 83Y. Although not shown in the figure, box 430M includes a filter that separates (or divides) the inner space of box 430M into two chambers: toner chamber (i.e., the third chamber) and air chamber (i.e., the fourth chamber). That is, the air chamber of box 430M is adjacent to the toner chamber via a filter. In addition, box 430C includes a filter that separates (or divides) the inner space of box 430C into two chambers: toner chamber (i.e., the fifth chamber) and air chamber (i.e., the sixth chamber). That is, the air chamber of box 430C is adjacent to the toner chamber via a filter. In addition, the cartridge 430K includes a filter that separates (or divides) the inner space of the cartridge 430K into two chambers: a toner chamber (ie, the seventh chamber) and an air chamber (ie, the eighth chamber). That is, the air chamber of the cartridge 430K is adjacent to the toner chamber via the filter.

[0101] The toner chamber 430Yc is located above the air chamber 430Yd, and the toner chamber 430Yc and the air chamber 430Yd are arranged in the Z direction. That is, the cartridge 430Y is attached to the device body 72 in a posture and orientation in which the toner chamber 430Yc is located above the air chamber 430Yd. The arrangement direction of the toner chamber 430Yc and the air chamber 430Yd is the Z direction. Therefore, in the present embodiment, the receiving port 430Yb1 opens toward the arrangement direction, and the discharge port 430Ya1 opens toward a direction intersecting the arrangement direction.

[0102] The toner chamber 430Yc stores toner T. In the toner chamber 430Yc, the toner T is supported by the filter 83Y.

[0103] In the air chamber 430Yd, toner is not stored. For example, the filter 83Y is a porous component made of resin fiber, and the size and density of the holes are determined to allow air to pass through and prevent toner from passing through. That is, the filter 83Y is made to allow air to pass through and prevent toner from passing through. As shown in Figures 8 and 9, the filter 83Y is held by the first frame 430Ya and the second frame 430Yb so that the outer edge portion 83Ya of the filter 83Y is clamped between the flange portion 430Ya2 of the first frame 430Ya and the flange portion 430Yb2 of the second frame 430Yb. The filter 83Y is inclined from the outer edge portion 83Ya toward the lowermost portion 83Yb located below the outer edge portion 83Ya. That is, the filter 83Y includes a portion (i.e., an inclined portion) extending downward as it extends toward (or approaches) the lowermost portion 83Yb in the X direction, the Y direction, or the horizontal direction.

[0104] The lowermost portion 83Yb is a portion that protrudes relative to the outer edge portion 83Ya in a direction extending from the toner chamber 430Yc toward the air chamber 430Yd. Fig. 8A and Fig. 9B As shown, the lowermost portion 83Yb is located at the central portion of the filter 83Y in the X direction and the Y direction. The filter 83Y is molded to have the above-described shape.

[0105] The discharge pipe 85Y (i.e., the path) is arranged in the colorant chamber 430Yc. The discharge pipe 85Y of the present embodiment is a component made of resin. However, the discharge pipe 85Y may be made of another material such as paper or rubber. The discharge pipe 85Y includes an inlet 85Ya (i.e., the first opening) and an outlet 85Yb (i.e., the second opening), and extends from the inlet 85Ya to the outlet 85Yb. The discharge pipe 85Y is the path through which the toner T stored in the colorant chamber 430Yc passes when the toner T moves toward the discharge outlet 430Ya1. The discharge pipe 85Y includes a first portion 85Y1 extending in the Z direction and provided with an inlet 85Ya, and a second portion 85Y2 extending in the X direction and provided with an outlet 85Yb. The direction in which the first portion 85Y1 extends and the direction in which the second portion 85Y2 extends intersect each other (in the present embodiment, the two directions are orthogonal to each other).

[0106] The outlet 85Yb of the discharge pipe 85Y is connected to the discharge port 430Ya1 so as to communicate with the discharge port 430Ya1. The inlet 85Ya of the discharge pipe 85Y is arranged to face the lowest part 83Yb as a part of the filter 83Y via a gap. Preferably, the inlet 85Ya is arranged closer to the filter 83Y. If the amount of the toner T remaining in the colorant chamber 430Yc is reduced, the toner T is fluidized by the air received via the receiving port 430Yb1, and moves along the above-mentioned inclined portion of the filter 83Y and gathers at the lowest part 83Yb. The inlet 85Ya of the discharge pipe 85Y can guide the toner T gathered at the lowest part 83Yb of the filter 83Y to the discharge port 430Ya1. Through this operation, even if the amount of the residual toner stored in the toner chamber 430Yc of the cartridge 430Y is reduced, the toner T can be efficiently discharged to the outside of the cartridge 430Y.

[0107] Since the box of this embodiment has a structure that discharges the toner to the outside of the box by air, the box does not require any rotating parts (such as screws). Therefore, the structure of the box can be simplified and has fewer parts.

[0108] The structure of cyclone separator

[0109] Next, the structures of the respective cyclone separators Cy of the present embodiment will be described with reference to Figures 10 and 11. Since the structures of the respective cyclone separators Cy are identical to one another, differing only in the direction in which the toner flows into the respective cyclone separators Cy, the structure of the cyclone separator CyY will be described below, and the description of the structures of the cyclone separators CyM, CyC, and CyK will be omitted.

[0110] Fig. 10A is the front view of the cyclone separator CyY, Fig. 10B is a top view of the cyclone separator CyY, Fig. 10C is a bottom view of the cyclone separator CyY. Fig. 10D is the left side diagram of cyclone separator CyY, and Fig.10E It is a right side view of the cyclone separator CyY. Fig.11A It is along Fig. 10B A cross-sectional view taken along line JJ. Fig. 11B is an exploded perspective view showing a cross section of the cyclone separator CyY taken along line JJ. Fig. 11C It is along Fig. 10A Note that the following description of the structure of the cyclone separator CyY will be given with respect to the cyclone separator CyY in a state (posture) in which the cyclone separator CyY is attached to the apparatus body 72. Fig. 10A The developer container 3Y (ie, the toner storage portion) to which the toner is supplied via the cyclone separator CyY is schematically shown. Fig.11AIn FIG. 1 , an imaginary straight line is shown to represent the central axis Ax of the tapered portion CyYb1. Fig. 11C In FIG. 1 , there are shown an imaginary straight line passing through the center axis Ax and extending in the X direction and an imaginary straight line passing through the center axis Ax and extending in the Y direction. These imaginary straight lines are used as a reference for showing an arrangement example of components related to the cyclone separator CyY.

[0111] The developing unit 9Y is attached to the apparatus body 72 in an orientation (posture) in which the inner diameter of the tapered portion CyYb1 decreases as the center axis Ax of the tapered portion CyYb1 extends in the gravity direction and toward the downward direction. That is, the following description will be given for the toner storage portion (the toner storage portion being oriented in a direction in which the inner diameter of the tapered portion CyYb1 decreases as the center axis Ax of the tapered portion CyYb1 extends in the gravity direction and toward the downward direction) and the cyclone separator CyYb1. FIG. 10A to FIG. 10E and FIG. 11A to FIG. 11C Description.

[0112] like FIG. 10A to FIG. 10E and FIG. 11A to FIG. 11C As shown, the cyclone separator CyY includes a cylindrical component CyYa (i.e., an upper component or a receiving component) serving as a first component, a truncated cone component CyYb (i.e., a lower component or a discharge component) serving as a second component, and an exhaust filter CyYf. The cylindrical component CyYa includes an inlet CyYa1, a cylindrical portion CyYa2, and an exhaust port CyYa3. The truncated cone component CyYb includes a tapered portion CyYb1 and a toner discharge port CyYb2.

[0113] The cyclone separator CyY is a separation device (i.e., a cyclone separation portion or a centrifugal separator) that receives air containing air and toner to be supplied to the developer container 3Y (i.e., the toner storage portion) and centrifugally separates the toner from the air. The cyclone separator CyY includes a toner discharge port CyYb2 (which serves as a first discharge port for discharging the toner to the inner space of the toner storage portion), and an exhaust port CyYa3 (which serves as a second discharge port for discharging the air to the outer space of the toner storage portion).

[0114] The cyclone separator CyY receives air containing toner through the inlet CyYa1; and performs centrifugal separation by generating a rotating flow of air in the internal space of the cylindrical portion CyYa2 and the tapered portion CyYb1. The cylindrical portion CyYa2 and the tapered portion CyYb1 are the main parts of the cyclone separator CyY, and generate a rotating flow of air containing toner in the space formed by them. The cyclone separator CyY discharges the toner separated from the air by performing the centrifugal separation from the toner discharge port CyYb2; and discharges the air separated from the toner by performing the centrifugal separation from the exhaust port CyYa3 and the exhaust filter CyYf.

[0115] In the following description, the direction along the central axis Ax of the conical portion CyYb1 formed in the shape of a truncated cone is defined as the axial direction (i.e., the axial direction) of the cyclone separator CyY. In the present embodiment, the axial direction of the cyclone separator CyY is substantially parallel to the Z direction (i.e., the gravity direction). However, the cyclone separator CyY may be arranged so that the axial direction obliquely intersects with the Z direction. In addition, the radial direction of an imaginary circle centered on the central axis Ax when the cyclone separator CyY is observed in the axial direction is defined as the radial direction of the cyclone separator CyY.

[0116] The cyclone separator CyY of this embodiment is a tangential inflow type, so the inlet CyYa1 is connected to contact the outer wall of the cylindrical part CyYa2. Fig. 11C As shown, the radius of the cylindrical portion CyYa2 relative to the center axis Ax is constant. In addition, the wall surface of the inlet CyYa1 farther from the center axis Ax in the radial direction extends along the tangent of the cylindrical portion CyYa2 in the connecting portion CyYa12 (i.e., the boundary portion) formed between the inlet CyYa1 and the cylindrical portion CyYa2.

[0117] The cyclone separator CyY may not be a tangential inflow type, and the radius of the cylindrical part CyYa2 may not be constant. For example, the cyclone separator CyY may be a semi-circular vortex type or a full-circular vortex type. In the case where the cyclone separator CyY is a semi-circular vortex type, the radius of the cylindrical part CyYa2 gradually decreases within a range of 180 degrees around the central axis Ax starting from the connecting part between the cylindrical part CyYa2 and the inlet CyYa1. In the case where the cyclone separator CyY is a full-circular vortex type, the radius of the cylindrical part CyYa2 gradually decreases within a range of 360 degrees around the central axis Ax starting from the connecting part between the cylindrical part CyYa2 and the inlet CyYa1.

[0118] like Fig.11A and Fig. 11BAs shown, the cylindrical portion CyYa2 of the cylindrical component CyYa and the tapered portion CyYb1 of the truncated cone component CyYb are arranged along the Z direction. The bottom of the cylindrical portion CyYa2 is connected to the top of the tapered portion CyYb1. The cylindrical portion CyYa2 is formed into a cylindrical shape, the center of which is the central axis Ax extending in the Z direction. The tapered portion CyYb1 is formed into a truncated cone shape, the center of which is the central axis Ax and the radius of which decreases as the truncated cone shape extends downward. The toner discharge port CyYb2 (i.e., the first discharge port) is formed at the lower end (i.e., the lower end portion) of the tapered portion CyYb1.

[0119] The bottom of the cylindrical part CyYa and the upper surface part of the truncated cone part CyYb are fixed to each other without any gap so that the toner does not leak from the connection part between the cylindrical part CyYa2 and the tapered part CyYb1 to the outside of the cyclone separator CyY and the developer container 3Y. For example, the fixing is performed by using an adhesive, but it can also be fixed by using ultrasonic welding or screws. More specifically, in the present embodiment, the annular protrusion CyYb3 ( Fig.11A and 11B ) is assembled in the annular recess CyYa5 formed in the bottom of the cylindrical member CyYa. The upper end surface of the convex portion CyYb3 contacts the upper end surface of the recess CyYa5, and the outer surface of the convex portion CyYb3 formed in the radial direction faces the inner surface of the recess CyYa5 formed in the radial direction. Thus, since the cylindrical member CyYa and the frustoconical member CyYb are fixed to each other so that a part of the cylindrical portion CyYa2 and a part of the tapered portion CyYb1 overlap each other in the Z direction, it is possible to more reliably reduce toner leakage. It is to be noted that the recess may be formed in the top of the frustoconical member CyYb, and the convex portion to be assembled in the recess may be formed on the bottom of the cylindrical member CyYa.

[0120] The inlet CyYa1 is an inlet (ie, an air intake, a receiving portion, or a receiving port) for receiving air containing toner. Fig. 11C The inlet CyYa1 of the present embodiment extends from the edge position of the inner wall of the cylindrical portion CyYa2 positioned in the X direction toward one side (i.e., LE side) in the Y direction. The inlet CyYa1 opens in a direction from the center portion of the corresponding developing roller 6Y toward the end portion of the developing roller 6Y (the center portion and the end portion of the developing roller 6Y are formed in the direction of the rotation axis direction of the developing roller 6Y).

[0121] The exhaust port CyYa3 is an opening portion (i.e., a second exhaust port) that is connected to the outside of the developer container 3Y (i.e., the toner storage portion). The exhaust port CyYa3 is an opening portion for discharging the air obtained by separating the toner from the mixed gas to the outside of the cyclone separator CyY. The exhaust port CyYa3 is arranged at the top (i.e., the upper end or the upper end surface) of the cylindrical portion CyYa2. The exhaust port CyYa3 of the present embodiment opens in the upper surface of the cylindrical portion CyYa2. The exhaust port CyYa3 of the present embodiment opens upward. The exhaust port CyYa3 of the present embodiment is located above the upper surface (i.e., the outer surface of the cover member 3Y1) of the developer container 3Y (i.e., the toner storage portion).

[0122] The exhaust port CyYa3 is provided at the upper end (i.e., the second end) of the tubular portion CyYa30 extending downward along the center axis Ax from the upper surface of the cylindrical portion CyYa2. The lower end CyYa31 (i.e., the first end) of the tubular portion CyYa30 provided with the exhaust port CyYa3 opens in the space inside the cylindrical portion CyYa2 and the tapered portion CyYb1 (see also Fig.13 ). The lower end CyYa31 of the tubular portion CyYa30 is located below the inner upper surface of the internal space of the developer container 3Y (i.e., the lower surface of the cover part 3Y1), and is located above the colorant discharge port CyYb2 (i.e., the first discharge port) of the cyclone separator CyY. That is, the cyclone separator CyY of the present embodiment includes a tubular portion CyYa30 extending downward from the exhaust port CyYa3 (i.e., the second discharge port). The lower end CyYa31 of the tubular portion CyYa30 opens in the internal space of the cyclone separator CyY formed by the cylindrical portion CyYa2 and the conical portion CyYb1. In addition, at least a portion of the tubular portion CyYa30 is located at the same position as the position of the inlet CyYa1 in the direction of the center axis Ax. In other words, when viewed in a direction orthogonal to the central axis Ax, at least a portion of the tubular portion CyYa30 is disposed at a position where the at least a portion of the tubular portion CyYa30 overlaps with the inlet CyYa1 .

[0123] The above-mentioned tubular portion CyYa30 has a function of preventing the airflow that has flowed into the internal space of the cyclone separator CyY from the inlet CyYa1 along the inner wall of the cylindrical portion CyYa2 and from which the toner has not yet been centrifugally separated from, from approaching the exhaust port CyYa3. By this function, the clogging suppression effect of the exhaust filter CyYf described below can be further improved. However, the tubular portion CyYa30 may not be provided. This is because the air mixed with the toner easily moves downward due to the self-weight of the toner, and it is difficult to move toward the exhaust port CyYa3 (or the exhaust filter CyYf) provided at a higher position.

[0124] The exhaust filter CyYf is attached to the upper surface of the cylindrical part CyYa. The exhaust filter CyYf is arranged to cover the exhaust port CyYa3 when viewed from above, and allows air to be discharged from the exhaust port CyYa3 and recovers the toner. That is, the exhaust filter CyYf allows air to pass through, and prevents the toner from passing through. In addition, a space (i.e., a chamber) formed by the chamber portion CyYc is provided between the exhaust port CyYa3 and the exhaust filter CyYf. The chamber portion CyYc has a concave shape in which a portion of the upper surface of the cylindrical part CyYa (including the circumferential edge of the exhaust port CyYa3) is recessed downward. The chamber is formed as a space surrounded by a concave bottom, a portion extending upward around the bottom (the portion is a portion to which the exhaust filter CyYf is attached), and the exhaust filter CyYf.

[0125] The area of ​​the cross section of the space (i.e., the chamber) formed by the chamber portion CyYc (at a plane perpendicular to the Z direction) is larger than the area of ​​the cross section of the exhaust port CyYa3 obtained in a plane perpendicular to the Z direction. That is, the cross-sectional area of ​​the cross section of the space (formed by the chamber portion CyYc) perpendicular to the extension direction of the tubular portion CyYa30 (which has the exhaust port CyYa3 formed in the upper end of the tubular portion CyYa30) is larger than the cross-sectional area of ​​the cross section of the tubular portion CyYa30 perpendicular to the extension direction of the tubular portion CyYa30. Therefore, the effective surface area of ​​the exhaust filter CyYf can be made larger than the effective surface area of ​​the exhaust filter CyYf arranged in a configuration in which the exhaust port CyYa3 directly faces the exhaust filter CyYf. The effective surface area of ​​the exhaust filter CyYf is the area of ​​a portion of the exhaust filter CyYf through which the air flows from the inside of the cyclone separator CyY to the outside of the cyclone separator CyY. If the total amount of toner particles attached to the exhaust filter CyYf is constant, the exhaust filter CyYf with a larger effective surface area is less likely to be clogged. The effective surface area of ​​the exhaust filter CyYf in this embodiment is the surface area of ​​the portion of the exhaust filter CyYf exposed to the chamber portion CyYc.

[0126] The toner discharge outlet CyYb2 is an opening portion (i.e., a first discharge outlet) that communicates with the interior of the developer container 3Y (i.e., a toner storage portion). The toner discharge outlet CyYb2 is an opening portion for discharging the toner separated from the air to the outside of the cyclone separator CyY. The toner discharge outlet CyYb2 is formed at the lower end of the tapered portion CyYb1. The toner discharge outlet CyYb2 of the present embodiment is formed into a circle with the central axis Ax as the center. The toner discharge outlet CyYb2 opens in the space inside the developer container 3Y (i.e., a storage space or a toner containing space that stores or contains toner used for image formation) (see Fig. 10A). The toner discharge port CyYb2 of this embodiment opens downward. The toner discharge port CyYb2 of this embodiment is located below the inner upper surface (ie, the inner surface of the cover member 3Y1) inside the developer container 3Y (ie, the toner storage portion).

[0127] In this embodiment, the truncated cone member CyYb of the cyclone separator CyY and the cover member 3Y1 ( Fig. 11B ) are formed integrally with each other by using a resin. That is, in the present embodiment, at least the conical portion CyYb1 of the cyclone separator CyY is formed integrally with the upper surface portion of the developer container 3Y (i.e., the toner storage portion). Being formed integrally with each other means being formed as a single component by using a method such as injection molding or cutting a resin material. Therefore, the truncated cone member CyYb and the cover member 3Y1 can be components that are integrally formed by using a single resin material.

[0128] In this embodiment, the developer container 3Y includes a main frame 3Y2 ( Fig. 10A ) and a cover member 3Y1 covering the top of the main frame 3Y2. A storage space for storing toner is formed between the main frame 3Y2 and the cover member 3Y1. Since the frustoconical member CyYb of the cyclone separator CyY and the cover member 3Y1 are formed integrally with each other, the structure for supplying toner to the developer container 3Y via the cyclone separator CyY can be simplified with a smaller number of parts. It is to be noted that the frustoconical member CyYb can be formed as a member different from the cover member 3Y1. In this case, the frustoconical member CyYb can be fixed to the cover member 3Y1 by using an adhesive or another method.

[0129] In this embodiment, the position of the toner discharge port CyYb2 of the cyclone separator CyY in the Y direction is located in the area where the developing roller 6Y is provided along the Y direction (hereinafter referred to as the width area W6 of the developing roller 6Y) (also see Fig.11A and Fig.13 ). The width region W6 of the developing roller 6Y is a range from one end to the other end of the outer peripheral surface (carrying toner) of the developing roller 6Y in the Y direction. In other words, in each developing unit 9, along the direction of the rotation axis of the developing roller 6 (i.e., the rotation axis direction of the developing roller 6), the first discharge port of the cyclone separator Cy is arranged at a position between the positions of the two end portions of the outer peripheral surface (i.e., the toner carrying portion) of the developing roller 6 in the rotation axis direction of the developing roller 6. As described below, by such an arrangement, the efficiency of toner conveyance can be improved.

[0130] Furthermore, in the present embodiment, the cyclone separator CyY is disposed in the upper surface portion of the developer container 3Y (i.e., the toner storage portion). The upper surface portion of the developer container 3Y is the surface (facing upward in the Z direction) of the developer container 3Y included in the top view of the developer container 3Y. Because the cyclone separator CyY is disposed in the upper surface portion of the developer container 3Y, the cyclone separator CyY and the developer container 3Y have a positional relationship in which the internal spaces of the cyclone separator CyY and the developer container 3Y overlap with each other when viewed in the Z direction. Therefore, compared with the area occupied by the developer unit 9Y when viewed in the Z direction in the positional relationship in which the cyclone separator CyY protrudes from the internal space of the developer container 3Y in the X direction or the Y direction when viewed in the Z direction, the area occupied by the developer unit 9Y when viewed in the Z direction can be reduced. As a result, miniaturization of the device can be achieved. Note that the sentence “two components overlap each other when viewed in a certain direction” means that when the components are vertically projected onto an imaginary plane orthogonal to the certain direction, a projection area of ​​one component and a projection area of ​​another component at least partially overlap each other.

[0131] Furthermore, in the present embodiment, when viewed in the Z direction, the toner discharge port CyYb2 of the cyclone separator CyY is aligned with the outer peripheral surface 6Ya ( Fig.13 ) overlap. In other words, in the direction of the rotation axis, the first discharge port is located between the positions of the two ends of the peripheral surface of the developing roller (i.e., the toner carrying portion) along the direction of the rotation axis of the developing roller; and when viewed in the direction of gravity, the first discharge port of the cyclone separator and the peripheral surface of the developing roller (i.e., the toner carrying portion) overlap each other. In this configuration, since the peripheral surface 6Ya of the developing roller 6Y is located directly below the toner discharge port CyYb2, the toner discharged from the toner discharge port CyYb2 can more easily reach the peripheral surface 6Ya of the developing roller 6Y. That is, the toner conveying efficiency can be further improved.

[0132] However, the toner discharge port CyYb2 and the outer peripheral surface 6Ya of the developing roller 6Y may have such a positional relationship that the toner discharge port CyYb2 and the outer peripheral surface 6Ya of the developing roller 6Y do not overlap each other when viewed in the direction of gravity. In this case, since the toner is conveyed along the X direction by the stirring members SY1 and SY2 provided in the developer container 3Y, the toner is supplied to the outer peripheral surface 6Ya of the developing roller 6Y. In another case, the developing unit 9Y may further include a supply roller that supplies the toner to the developing roller 6Y.

[0133] In addition, in the present embodiment, the tapered portion CyYb1 of the cyclone separator CyY is located relative to the inner surface 3Y1a ( Fig.13 ) protrudes downward. In other words, the cyclone separator CyY is arranged in the upper surface portion of the developer container 3Y (i.e., the colorant storage portion), and a portion of the cyclone separator CyY is buried in a portion of the toner storage portion that is below the upper surface portion of the toner storage portion. In other words, at least a portion of the tapered portion CyYb1 protrudes downward relative to the inner upper surface (i.e., the inner surface 3Y1a) of the interior of the developer container 3Y (i.e., the colorant storage portion). Through this configuration, the developing unit 9Y can be miniaturized in the Z direction. That is, the height occupied by the cyclone separator CyY and the developer container 3Y in the Z direction is less than the height occupied by the cyclone separator CyY and the developer container 3Y in the Z direction in a configuration in which the entire cyclone separator CyY is arranged on the upper side of the upper surface portion of the developer container 3Y. It should be noted that in the present embodiment, the entire tapered portion CyYb1 protrudes downward relative to the inner surface 3Y1a of the cover member 3Y1. However, only a part of the tapered portion CyYb1 may protrude downward relative to the inner surface 3Y1a of the cover member 3Y1.

[0134] Note that the tapered portion CyYb1 may be shortened to achieve miniaturization of the developing unit 9Y. However, if the tapered portion CyYb1 is shortened, the separation performance of the cyclone separator CyY may be reduced. In the configuration of the present embodiment, since it is not necessary to excessively shorten the tapered portion CyYb1, both the separation performance of the cyclone separator CyY and the miniaturization of the developing unit 9Y can be achieved simultaneously.

[0135] Toner conveying mechanism

[0136] Next, a mechanism for conveying the toner stored in the toner chamber 430Yc of the cartridge 430Y to the developing unit 9Y will be described.

[0137] like Figure 5A As shown, the air ejected from the ejection port 80Ya of the pump unit 80Y is received in the air chamber 430Yd through the receiving port 430Yb1 of the box 430Y. Then, the air increases the air pressure of the air chamber 430Yd, passes through the filter 83Y, and flows into the colorant chamber 430Yc. The air that has flowed into the colorant chamber 430Yc enters the space between the particles of the colorant T and fluidizes the colorant T. The toner T that has been mixed with the air and fluidized is moved by the air received into the air chamber 430Yd through the receiving port 430Yb1. The toner moves from the inlet 85Ya to the outlet 85Yb through the discharge pipe 85Y, and is discharged from the discharge port 430Ya1 to the outside of the box 430Y.

[0138] Since the air chamber 430Yd is formed between the ejection port 80Ya and the filter 83Y as a space with high airtightness, the air ejected from the ejection port 80Ya efficiently flows to the filter 83Y without being dispersed to the outside of the box 430Y. For example, if the box 430Y vibrates or is placed for a long time, the toner T in the toner chamber 430Yc will gather. In such a case, a higher pressure may be required to allow the air to pass through the filter 83Y and flow into the toner chamber 430Yc. Even in this case, by continuously sending air from the pump unit 80Y to the air chamber 430Yd and increasing the pressure (i.e., air pressure) of the air chamber 430Yd, the air is allowed to pass through the filter 83Y and flow into the toner chamber 430Yc. In addition, since the air chamber 430Yd is formed, the pump unit 80Y only needs to have the performance of generating a pressure that can continuously send air into the air chamber 430Yd until the value of the pressure allows the air to enter the toner chamber 430Yc through the filter 83Y. That is, the pump unit 80Y does not require specific performance in terms of the ejection speed and ejection rate. Therefore, a small pump unit can be used as the pump unit 80Y, which contributes to the miniaturization of the device.

[0139] like Figure 5A As shown, the toner T discharged from the discharge port 430Ya1 of the cartridge 430Y enters the interior of the supply pipe 444Y from the upstream end 444Yu through the receiving port 429Ya of the cartridge holder 429. The toner T that has entered the interior of the supply pipe 444Y from the upstream end 444Yu is moved to the downstream end 444Yd by the air that has been discharged from the discharge port 430Ya1 of the cartridge 430Y and has entered the upstream end 444Yu like the toner T. The toner T that has moved to the downstream end 444Yd flows into the cyclone separator CyY through the inlet CyYa1 together with the air.

[0140] like Fig.11A and 11CAs shown, the air containing the toner and having flowed into the cyclone separator CyY moves downward while rotating around the central axis Ax in the cylindrical portion CyYa2 and the tapered portion CyYb1. In this process, the toner T moves by centrifugal force, thereby approaching the inner wall of the cylindrical portion CyYa2 and the inner wall of the tapered portion CyYb1; and moves along the inner wall. As the air containing the toner T moves closer to the toner discharge port CyYb2, the cross-sectional area of ​​the tapered portion CyYb1 decreases. Therefore, when the toner T continuously moves along the inner wall of the tapered portion CyYb1 by the centrifugal force, the air having a specific gravity less than that of the toner T is pushed toward the center side of the cylindrical portion CyYa2 and the tapered portion CyYb1. The air pushed in this way flows along the central axis Ax toward the exhaust port CyYa3 connected to the external space of the cyclone separator CyY. As a result, when the air containing the toner T reaches the vicinity of the toner discharge port CyYb2, most of the air turns and becomes an ascending airflow, and is discharged to the outside of the developer container 3Y through the exhaust port CyYa3, the chamber portion CyYc, and the exhaust filter CyYf. Note that if the exhaust filter portion PYf (FIG. 3) is provided in the developer container 3Y as described below, and the developer container 3Y is not airtight, a part of the air is discharged from the toner discharge port CyYb2 to the developer container 3Y.

[0141] On the other hand, even near the toner discharge port CyYb2, the toner T continues to move downward while rotating due to its own weight, and is discharged from the toner discharge port CyYb2 and stored in the storage space formed in the developer container 3Y. In this way, the toner T is supplied from the cartridge 430Y to the developing unit 9Y of the process unit PY.

[0142] As described above, the toner is supplied to the developing unit 9Y in a state where most of the air is separated from the toner T by the cyclone separator CyY. That is, in the present embodiment, the toner can be supplied to the developer container 3Y (i.e., the toner storage portion) in a state where the toner is separated from the air. Therefore, the separation performance can be maintained for a longer time compared to the separation performance of the configuration in which the toner is separated from the air mainly by the filter.

[0143] In the present embodiment, since the toner T is supplied to the developing unit 9Y in a state where most of the air is separated from the toner T by the cyclone separator CyY, the increase in the internal pressure of the developing unit 9Y caused by the inflow of air can be reduced. Since the increase in the internal pressure of the developing unit 9Y is reduced, the toner can be prevented from leaking from the developing unit 9Y (for example, the toner T and the air are scattered from the opening portion of the developer container 3Y in which the developing roller 6Y is provided). In addition, since the increase in the internal pressure of the developing unit 9Y is reduced, the load for driving the pump unit 80Y is hardly increased. As a result, a pump unit such as a relatively small pump unit can be used as the pump unit 80Y, which contributes to the miniaturization of the device.

[0144] In this embodiment, since the air from which most of the colorant T has been separated is discharged from the exhaust port CyYa3, the exhaust filter CyYf is hardly clogged with the colorant T, thereby improving the durability of the colorant conveying function from the colorant container to the developer container.

[0145] Furthermore, as shown in FIG. 3 , in order to improve the exhaust performance of exhausting air to the outside of the developing unit 9, in addition to the exhaust filter of the corresponding cyclone separator Cy, each exhaust filter portion PYf, PMf, PCf and PKf (i.e., other filters) may be provided on the upper surface of the corresponding developing unit 9. Hereinafter, the exhaust filter portions PYf, PMf, PCf and PKf are referred to as each exhaust filter portion Pf. Each exhaust filter portion Pf is a portion in which a filter made of a nonwoven fabric or the like is attached to an opening (i.e., an exhaust hole or a through hole) so as to cover the opening formed in the upper surface of the corresponding frame (i.e., a cover member) forming the corresponding developing unit 9.

[0146] The toner T flowing into each developing unit 9 through the corresponding cyclone separator Cy remains in the developing unit 9, and at least a part of the air flowing into the developing unit 9 together with the toner T is discharged from the exhaust filter portion Pf to the outside of the developing unit 9. In this configuration, since the increase in the internal pressure inside each developing unit 9 is further reduced, the toner T and the air easily flow from the corresponding cartridge 430 to the developing unit 9 through the corresponding supply pipe 444. Since each exhaust filter portion Pf is provided in the corresponding developing unit 9, the toner T (and a part of the air) easily flows into the corresponding developing unit 9 through the corresponding cyclone separator Cy.

[0147] In the present embodiment, each exhaust filter portion Pf is provided in a portion of the upper surface of the corresponding developing unit 9, and is formed downstream of the corresponding cyclone separator Cy along the direction in which the toner flows into the cyclone separator Cy. That is, the exhaust filter portion PYf of the developing unit 9Y is provided in a portion of the upper surface of the developing unit 9Y, and is formed on the RE side of the cyclone separator CyY along the Y direction; the exhaust filter portion PMf of the developing unit 9M is provided in a portion of the upper surface of the developing unit 9M, and is formed on the RE side of the cyclone separator CyM along the Y direction. The exhaust filter portion PCf of the developing unit 9C is provided in a portion of the upper surface of the developing unit 9C, and is formed on the left side of the cyclone separator CyC along the Y direction; the exhaust filter portion PKf of the developing unit 9K is provided in a portion of the upper surface of the developing unit 9K, and is formed on the left side of the cyclone separator CyK along the Y direction. In other words, the developer container 3 (i.e., the toner storage portion) of each developing unit 9 includes an opening and an exhaust filter covering the opening, and the opening is provided at a position farther from the inlet (i.e., the inflow port) of the cyclone separator Cy than the exhaust port in the direction of the rotation axis of the developing roller 6. In this configuration, by using an area where each supply pipe 444 connected to the corresponding cyclone separator Cy is not provided, the exhaust performance of the air can be improved. It is to be noted that each exhaust filter portion may be provided not in the upper surface of the corresponding developing unit 9, but in the side surface of the developing unit 9.

[0148] The toner supplied to the developing unit 9Y from the end of the developing unit 9Y (i.e., the developer container 3Y) formed in the Y direction is Figure 5B and Fig.13 The stirring parts SY1 and SY2 shown in the figure stir and become uniform. Each of the stirring parts SY1 and SY2 can be a screw that transports the colorant from the end of the developing unit 9Y on one side (i.e., LE side) of the downstream end 444Yd of the supply pipe 444Y connected to the developing unit 9Y along the Y direction to the end on the other side of the developing unit 9Y. Each stirring part SY1 and SY2 may not be a screw with a spiral blade formed on the rotating shaft. For example, each stirring part SY1 and SY2 can be a paddle-shaped rotating part in which many short blades or protrusions are formed on the rotating shaft. In addition, depending on the stirring efficiency of the colorant T required in the developing unit 9Y, the number of stirring parts can be one, three or more.

[0149] In the present embodiment, the toner discharge port CyYb2 of the cyclone separator CyY is provided in the upper surface of the developer container 3Y and is in the width region W6 of the developer roller 6Y in the Y direction (the width region W6 is the region where the toner T is used). Therefore, the toner T supplied from the toner discharge port CyYb2 is allowed to easily reach the developer roller 6Y in the developer container 3Y. More specifically, the distance for conveying the toner T in the Y direction in order to spread the toner T over the width region W6 of the developer roller 6Y is shortened compared to the distance for conveying the toner T in the configuration in which the toner discharge port CyYb2 is provided outside the width region W6 of the developer roller 6Y in the Y direction. In addition, the toner can be efficiently conveyed from the cartridge 430Y to the developer roller 6Y.

[0150] It should be noted that in this embodiment, Figure 3A As shown, in consideration of the pressure loss, an example in which each cyclone separator Cy is provided in the end portion of the corresponding developing unit 9 formed in the Y direction is described. However, in a modified example, as shown in FIG. Fig.12 As shown, each cyclone separator Cy can be arranged in the Y direction at a substantially central portion of the corresponding developing unit 9. The center of each developing unit 9 in the Y direction is an intermediate position between the position of one end of the corresponding developer container 3 and the position of the other end of the developer container 3 along the Y direction.

[0151] like Fig.11A As shown, the toner T moves downward while rotating in the cyclone separator CyY, and flows from the toner discharge port CyYb2 into the storage space formed in the developer container 3Y. The toner T discharged from the toner discharge port CyYb2 has momentum in the direction along the inner wall of the tapered portion CyYb1 (that is, in the tangential direction of the circumference of the tapered portion CyYb1). Therefore, not all of the toner T falls vertically from the toner discharge port CyYb2 along the Z direction, and the other toner T is dispersed in the developing unit 9Y while moving in directions other than the Z direction. As a result, the efficiency of stirring performed in the developing unit 9Y can be improved. In addition, since the toner T is easily spread over the width area W6 of the developing roller 6Y, the toner can be efficiently transported.

[0152] Incidentally, when the toner T is supplied to the developer container 3Y via the cyclone separator CyY, the toner T in the developer container 3Y may be rolled up and flow back to the cyclone separator CyY. That is, the flow of the toner T discharged from the toner discharge port CyYb2 may collide with the toner T that has accumulated in the developer container 3Y, and part of the toner may be rolled up and flow into the cyclone separator CyY from the toner discharge port CyYb2. In the following description, reference will be made to Fig.13Describe the preferred positions of the various parts of the cyclone separator CyY in the Z direction. Fig.13 It is along Figure 4B Cross-sectional view taken along line CC.

[0153] like Fig.13 As shown, if the surface of the toner T in the developer container 3Y (hereinafter referred to as the toner top surface Ts) has a higher position, when the toner is supplied, the toner T may be rolled up and reach the cylindrical portion CyYa2. That is, the toner T in the developer container 3Y may flow back to the cyclone separator CyY, and may be rolled up above the lower end position TL2 of the cylindrical portion CyYa2. In this case, the rolled-up toner T may flow into the exhaust port CyYa3 and cause the separation performance of the cyclone separator CyY to decrease. In addition, the toner T flowing into the exhaust port CyYa3 may cause the clogging suppression effect of the exhaust filter CyYf to deteriorate.

[0154] Therefore, it is preferred that the lower end position TL2 of the cylindrical portion CyYa2 along the Z direction (i.e., the direction of gravity) is higher than the colorant top surface Ts. Specifically, it is preferred that the lower end position TL2 of the cylindrical portion CyYa2 is located above the uppermost portion of the outer peripheral surface 6Ya of the developing roller 6Y (i.e., the uppermost portion of the colorant carrying portion). It is preferred that the lower end position TL2 of the cylindrical portion CyYa2 is located above the stirring members SY1 and SY2 (i.e., located above the upper edge position of the stirring member). If a plurality of stirring members are provided, it is preferred that the lower end position TL2 of the cylindrical portion CyYa2 is located above a stirring member (i.e., the highest stirring member) that is higher than the position of any other stirring member. By such an arrangement, the possibility of the toner T that is rolled up when the toner is supplied flowing into the exhaust port CyYa3 can be reduced.

[0155] Preferably, the position TL1 of the toner discharge outlet CyYb2 in the Z direction (i.e., the direction of gravity) is located above the toner top surface Ts. Specifically, it is preferred that the position TL1 of the toner discharge outlet CyYb2 in the direction of gravity is located above the uppermost portion of the peripheral surface 6Ya of the developing roller 6Y. Preferably, the position TL1 of the toner discharge outlet CyYb2 is located above the stirring members SY1 and SY2. That is, it is preferred that the first discharge outlet is located above the uppermost portion of the toner carrying portion of the developing roller. By such an arrangement, the possibility of the toner T rolled up when the toner is supplied flowing into the exhaust port CyYa3 can be reduced.

[0156] In addition, it is preferred that the position TL1 of the toner discharge port CyYb2 in the Z direction (i.e., the direction of gravity) is located above the rotation axis of each stirring member SY1 and SY2 (if multiple stirring members are provided, it is preferred that the position TL1 of the toner discharge port CyYb2 in the Z direction is located above the rotation axis of the stirring member that is higher than the position of any other stirring member). That is, in the case where the rotation axis of the developing roller 6Y is defined as the first rotation axis, the image forming device further includes a stirring member that rotates on the second rotation axis for stirring the toner stored in the toner storage portion. In this case, the first discharge port is located above the second rotation axis of the stirring member along the direction of gravity. The second rotation axis of the present embodiment is the rotation axis of the stirring member SY1. By such an arrangement, the possibility of the toner T that is rolled up when the toner is supplied flowing into the exhaust port CyYa3 can be reduced.

[0157] In the present embodiment, the rotation axis (ie, the second rotation axis) of the stirring member SY1 is located above the rotation axis (ie, the first rotation axis) of the developing roller 6Y.

[0158] In a configuration in which the direction of the conveying path is changed midway like the respective supply pipes 444 of the present embodiment, or in a configuration in which the toner conveying path is changed according to a plurality of process units P or developing units 9, air is preferably used as a conveying medium for conveying toner. In this configuration, compared with a configuration in which a screw or the like is used as a conveying portion, it is possible to make the conveying path more flexible in designing, and since the need for a conveying component is eliminated, the number of components can be reduced.

[0159] Each supply pipe 444 is an example of a channel forming portion, which is connected between the discharge port of the corresponding box 430 (i.e., the toner container) and the inlet port of the corresponding cyclone separator Cy, and forms a channel for the mixed gas. It should be noted that in the present embodiment, the entire channel extending from the discharge port of each box 430 (i.e., the toner container) to the inlet port of the corresponding cyclone separator Cy is the corresponding supply pipe 444 formed as a cylindrical member. However, only a part of the channel may be used as the supply pipe 444.

[0160] like Figure 4B and Fig.11AAs shown, in the present embodiment, it is preferable that the inlet of each cyclone separator Cy faces the direction of the rotation axis of the developing roller 6 of the corresponding developing unit 9 (i.e., the Y direction). In the present embodiment, since the direction of the rotation axis of each developing roller 6 is substantially equivalent to the Y direction, it is preferable that the inlet of each cyclone separator Cy faces the LE side or the RE side in the Y direction. That is, it is preferable that the inlet of each cyclone separation portion opens in a direction from the central portion of the corresponding developing roller in the direction of the rotation axis toward the end of the developing roller. For example, in this arrangement, the downstream end portion 444Yd of the supply pipe 444Y can be connected to the inlet CyYa1 in a shape that does not cause the downstream end portion 444Yd to be sharply bent.

[0161] It is to be noted that each supply pipe 444 has a shape in which the supply pipe 444 is bent so that the toner conveying path extending from the corresponding cartridge 430 to the corresponding developing unit 9 does not block the optical path L extending from the laser scanner unit LB to the corresponding photosensitive drum 4. That is, each supply pipe 444 includes a corresponding one of the middle portions (i.e., first portions) 444Yi, 444Mi, 444Ci, and 444Ki, which passes outside the optical path L and extends in a direction intersecting the rotation axis direction of the developing roller 6 (i.e., the Y direction). In the present embodiment, the middle portions 444Yi, 444Mi, 444Ci, and 444Ki extend along the X direction. Furthermore, each supply pipe 444 includes a downstream end portion (i.e., second portion), which is connected to the inlet of the corresponding cyclone separator Cy and is bent relative to the corresponding one of the middle portions 444Yi, 444Mi, 444Ci, and 444Ki, so as to extend in a direction along the rotation axis direction of the developing roller 6 (i.e., the Y direction). The downstream end of each supply pipe 444 is a corresponding one of the downstream ends 444Yd, 444Md, 444Cd and 444Kd described above. Therefore, as described above, it is preferred that the inlet of each cyclone separator Cy faces the LE side or the RE side in the Y direction.

[0162] Furthermore, in the present embodiment, the inlet of each cyclone separator Cy is arranged on a side away from the corresponding box 430 along the X direction (the direction in which each processing unit P is arranged). Fig. 11C As shown, relative to the central axis Ax of the cyclone separator CyY in the X direction, the inlet CyYa1 of the cyclone separator CyY is arranged at Fig. 11C The upper side of the Fig. 11CBy such a configuration, the curvature radius of the curved portion of each supply pipe 444 (the curved portion is formed between the middle portion and the downstream end) can be increased without blocking the optical path L, so that the assembly work of each supply pipe 444 can be made easier. In addition, when the toner is supplied, the toner is subjected to centrifugal force in the curved portion between the middle portion and the downstream end, so that the toner deviates toward the outside in the curved portion of each supply pipe 444. Fig. 11C As shown, when viewed in the Z direction, the inner wall surface on the outer side of the curved portion of each supply pipe 444 is continuous with the inner surface of the cylindrical portion of the corresponding cyclone separator Cy. Therefore, the mixed gas is introduced into each cyclone separator Cy in a state where the toner is deviated toward the inner surface side of the cylindrical portion, so that the separation efficiency can be further improved.

[0163] The above-described configurations of the cyclone separator CyY and the developing unit 9Y can also be applied to the other cyclone separators CyM, CyC, and CyK respectively provided in the developing units 9M, 9C, and 9K.

[0164] Second embodiment

[0165] In the first embodiment described above, as an example, the configuration in which the toner T is supplied from each supply pipe 444 to the storage space of the corresponding developer container 3 through the corresponding cyclone separator Cy has been described. In the second embodiment, in addition to the storage space for the toner T, a passage for the mixed gas may also be provided in each developer container 3. In this embodiment, the mixed gas containing the toner T flows from each supply pipe 444 into the passage formed in the corresponding developer container 3, and the toner T is supplied from the passage to the storage space through the corresponding cyclone separator Cy. Figures 14 to 16B Hereinafter, unless otherwise specified, components assigned the same reference numerals as those of the first embodiment have substantially the same structure and effect as those described in the first embodiment, and features different from those of the first embodiment will be mainly described.

[0166] Fig.14 4 is a perspective view of the image forming unit 500 in a state where each cartridge 430 is attached to the image forming unit 500 . Fig.14 Also shown are respective optical paths L (LY, LM, LC, LK) of laser beams traveling from the laser scanner unit LB to the corresponding photosensitive drums 4. Fig.15 is a top view of the image forming unit 500 . Fig.16A It is along Fig.15 Cross-sectional view taken along line CC. Fig. 16B It shows that Fig.16A3 is a diagram showing a state in which the cylindrical member CyYa of the cyclone separator CyY is removed from the frustoconical member CyYb and the cover member 3Y1 of the developer container 3.

[0167] like Fig.15 As shown, the downstream end portion 444Yd of the supply pipe 444Y is connected to a passage 445Y provided in the developer container 3Y. Fig.16A and Fig. 16B As shown, the channel 445Y is formed by a channel inlet 3Ya1, a channel wall surface 3Ya2 and a channel top surface CyYa4. The channel inlet 3Ya1 and the channel wall surface 3Ya2 are formed integrally with the cover part 3Y1 of the developer container 3Y, and the channel top surface CyYa4 is formed integrally with the cylindrical part CyYa of the cyclone separator CyY. The channel inlet 3Ya1 is located at the end of the developer container 3Y in the Y direction (i.e., the end of the developing unit 9Y). In addition, the cyclone separator CyY is located at the approximate center part of the developer container 3Y in the Y direction (i.e., the approximate center part of the developing unit 9Y). The channel 445Y extends in the Y direction, extending from the channel inlet 3Ya1 to the inlet CyYa1 of the cyclone separator CyY through the conveying space formed between the channel wall surface 3Ya2 and the channel top surface CyYa4. The conveying space of the passage 445Y is formed at the top of the developer container 3Y; and is separated from the storage space of the toner T formed in the developer container 3Y by the passage wall surface 3Ya2 and the cyclone separator CyY.

[0168] The channel inlet 3Ya1, the channel wall surface 3Ya2 and the channel top surface CyYa4 are examples of the channel forming part forming the channel 445Y, and the channel 445Y is connected to the inlet CyYa1 of the cyclone separator CyY. The channel is a channel through which the mixed gas flows, and the channel is separated from the internal space of the developer container 3Y (i.e., the toner storage part). The channel forming part is fixed to the developer container 3Y (i.e., the toner storage part). As in the present embodiment, it is preferred that at least a part of the channel forming part is formed integrally with the developer container 3Y (i.e., the toner storage part).

[0169] The toner T that has been conveyed to the downstream end portion 444Yd of the supply pipe 444Y flows into the channel 445Y from the channel inlet 3Ya1 provided at the end portion of the developer container 3Y in the Y direction, and flows into the inlet CyYa1 of the cyclone separator CyY through the channel 445Y. Therefore, in the present embodiment, a conveying path for the toner T that is formed in the Y direction and extends from the end portion of the developer container 3Y to the cyclone separator CyY provided at the substantially central portion of the developer container 3Y is formed by the channel 445Y fixed to the top portion of the developer container 3Y.

[0170] Preferably, the position of the supply pipe 444Y in the X direction is restricted so that the supply pipe 444Y does not block the light path L. If a configuration is added to restrict the position of each supply pipe 444 in the X direction so as not to block the corresponding light path L, the device will become complicated and large-scale. However, in this embodiment, since the conveying path for the toner T is formed by the channel 445Y fixed to the top of the developer container 3Y, it is possible to prevent each supply pipe 444 from blocking the corresponding light path L without using any additional configuration.

[0171] Other Examples

[0172] In the above-described respective embodiments, the configuration in which the exhaust filter CyYf is provided on the exhaust port CyYa3 of the cyclone separator CyY has been described as an example. However, if the cyclone separator CyY has high separation performance, the exhaust filter CyYf may not be provided.

[0173] In the above-described respective embodiments, description has been given of the configuration in which each pump unit 80 provided in the apparatus body 72 of the image forming apparatus 1 ejects air so as to supply a mixed gas containing air from the pump unit 80 and toner from the corresponding cartridge 430 to the corresponding cyclone separator Cy. However, the configuration of each cyclone separator Cy described in the respective embodiments is applicable as long as a mixed gas containing air and toner to be supplied can be supplied to the cyclone separator Cy.

[0174] For example, although each pump unit 80 and the corresponding box 430 have a series relationship (that is, a relationship in which the air ejected from the pump unit 80 passes through the inside of the corresponding box and discharges the mixed gas), each pump unit 80 and the corresponding box 430 (i.e., the toner container) may have a parallel relationship. That is, the passage of the air discharged from the pump unit 80 and the passage of the toner discharged from the corresponding box 430 may merge with each other, and the mixed gas may flow from the confluent portion to the corresponding cyclone separator Cy. In this case, in order to convey the toner to the confluent portion, a discharge unit (or powder pump) that discharges the toner from the box 430 (i.e., the toner container) may be provided.

[0175] Each pump unit 80 is an example of an air supply portion for supplying air (the air for supplying toner) to the corresponding developing unit. The air supply portion may not be a pump but a fan.

[0176] In addition, the device for generating the air flow for conveying the toner may be a part of the toner container. For example, a positive displacement pump formed in a bellows shape may be provided at the end of a cylindrical toner bottle. In this case, the positive displacement pump may expand and contract as the toner bottle rotates, so that a mixed gas containing air and toner may be discharged from the toner bottle.

[0177] In another case, the image forming apparatus 1 may be configured to supply toner from the outside of the image forming apparatus 1 to each developer container 3 by using a toner container. For example, the toner container may be attached to an attachment portion provided in the image forming apparatus 1, and a mixed gas containing air and toner may be discharged by a user who operates the toner container. The toner container may be a container formed in a bag shape and having air and toner enclosed therein (i.e., a bag-shaped container), or may be a container formed in a cylindrical shape and having air and toner enclosed therein.

[0178] In each of the above-described embodiments, each developing unit 9 may be a box (i.e., a developing box) that can be attached to and detached from the device body 72. In addition, each processing unit P including the corresponding developing unit 9 may be a box (i.e., a processing box) that can be attached to and detached from the device body 72.

[0179] The present disclosure can provide a novel configuration for supplying toner by using air.

[0180] Other embodiments

[0181] While the present invention has been described with reference to exemplary embodiments, it is to be understood that the invention is not limited to the disclosed exemplary embodiments. The scope of the following claims is to be accorded the broadest interpretation so as to encompass all such modifications and equivalent structures and functions.

Claims

1. An image forming device, comprising: Photosensitive drum; a toner storage portion configured to store toner, the toner being supplied to the toner storage portion by using air; a developing roller configured to rotate about a rotation axis, the developing roller including a toner carrying portion configured to carry the toner stored in the toner storing portion and supply the toner to the photosensitive drum; as well as a cyclone separation portion including an inlet, a first discharge port communicating with the inside of the toner storage portion, and a second discharge port communicating with the outside of the toner storage portion, the cyclone separation portion being configured to receive air mixed with toner through the inlet, separate the toner and the air from each other, discharge the toner separated from the air through the first discharge port, and discharge the air separated from the toner through the second discharge port, wherein the cyclone separation portion is provided on an upper surface portion of the toner storage portion, wherein the cyclone separation portion includes a tapered portion formed in a frustoconical shape, the radius of the frustoconical shape decreasing as the frustoconical shape extends downward, wherein the first discharge port is disposed at the lower end of the tapered portion, and At least a portion of the tapered portion protrudes downward relative to an upper surface of an interior of the toner storage portion.

2. The image forming apparatus according to claim 1, The first discharge port is arranged above the uppermost portion of the toner carrying portion of the developing roller along the gravity direction.

3. The image forming apparatus according to claim 1, wherein the first discharge port and the toner carrying portion of the developing roller overlap each other when viewed in the direction of gravity.

4. The image forming apparatus according to claim 1, wherein the tapered portion of the cyclone separating portion is integrally formed with an upper surface portion of the toner storing portion.

5. The image forming apparatus according to claim 1, The first discharge port is provided between positions of both ends of the toner carrying portion in the direction of the rotation axis.

6. The image forming apparatus according to any one of claims 1 to 5, The inlet is opened in a direction from a center portion of the developing roller toward an end portion of the developing roller in the direction of the rotation axis of the developing roller.

7. The image forming apparatus according to any one of claims 1 to 5, wherein the rotation axis is a first rotation axis, wherein the image forming apparatus further includes a stirring member configured to rotate about a second rotation axis for stirring the toner stored in the toner storage portion, and The first discharge port is arranged above the second rotation axis of the stirring member along the direction of gravity.

8. The image forming apparatus according to any one of claims 1 to 5, The cyclone separation portion further includes a filter disposed to cover the second discharge port and configured to allow air to pass therethrough and block toner from passing therethrough.

9. The image forming apparatus according to claim 8, wherein the cyclone separation portion further comprises a tubular portion and a chamber portion, the tubular portion extending downward from the second discharge port in the direction of the central axis of the tapered portion, the lower end of the tubular portion opening in the inner space of the cyclone separation portion, and the chamber portion being configured to form a space between the second discharge port and the filter, and The area of ​​the cross section of the space formed by the chamber portion at a plane perpendicular to the extending direction of the tubular portion is larger than the area of ​​the cross section of the tubular portion at a plane perpendicular to the extending direction of the tubular portion.

10. The image forming apparatus according to any one of claims 1 to 5, further comprising: an air supply portion configured to supply air; as well as A colorant container configured to store the colorant to be supplied to the colorant storage portion, the colorant container including a receiving port configured to receive the air supplied from the air supply portion, and a discharge port configured to discharge the colorant stored in the colorant container together with the air supplied from the air supply portion.

11. The image forming apparatus according to claim 10, further comprising: A pipe is connected to the discharge port of the toner container and the inlet of the cyclone separation portion and through which air mixed with toner passes.

12. The image forming apparatus according to claim 11, further comprising: an exposure unit configured to expose the photosensitive drum to form a latent image, wherein the inlet opens in a direction from a central portion of the developing roller toward an end portion of the developing roller in a rotation axis direction of the developing roller, and The tube includes a first part and a second part, the first part extends in a direction intersecting the rotation axis and is arranged on the outside of the light path from the exposure unit toward the photosensitive drum along the direction of the rotation axis, and the second part is connected to the first part, extends in the direction of the rotation axis, and is connected to the inlet.

13. The image forming apparatus according to claim 10, further comprising: a tube having one end connected to a discharge port of the toner container and through which air mixed with toner passes; as well as a channel forming portion configured to form a channel connected to the other end of the tube and the inlet of the cyclone separation portion, through which the air mixed with the toner flows and which is separated from the inner space of the toner storage portion, wherein the passage forming portion is fixed to the toner storage portion.

14. The image forming apparatus according to any one of claims 1 to 5, The toner storage portion includes an opening and a filter covering the opening, the opening being formed at a position farther from the inlet than the second discharge port in the direction of the rotation axis of the developing roller, and the filter being configured to allow air to pass therethrough and prevent toner from passing therethrough.

15. A toner container, comprising: (i) a container constituting a toner accommodating space configured to accommodate toner; as well as (ii) a cyclone separation portion, the cyclone separation portion (ii-i) including a tapered portion and (ii-ii) configured to (ii-ii-i) receive air with toner, (ii-ii-ii) separate air and toner, (ii-ii-iii) discharge the toner separated from the air into the toner accommodating space, and (ii-ii-iv) discharge the air separated from the toner to the outside of the container, When the colorant container is oriented in a direction in which the central axis of the tapered portion extends in the direction of gravity and the inner diameter of the tapered portion decreases in the direction of gravity, at least a portion of the tapered portion protrudes downward relative to the upper surface of the interior of the container constituting the colorant accommodating space.

16. A developing device, comprising: (i) a container constituting a toner accommodating space configured to accommodate toner; (ii) a developing roller, the developing roller (ii-i) including a toner carrying portion for carrying the toner accommodated in the toner accommodating space and (ii-ii) configured to rotate about a rotation axis; as well as (iii) a cyclone separation portion configured to separate toner and air, the cyclone separation portion comprising: (iii-i) an air inlet for receiving air with toner to flow into the cyclone separation portion, (iii-ii) a first discharge port through which the toner separated from the air is discharged from the cyclone separation portion into the toner accommodating space, the first discharge port being provided in a container region between both end portions of the toner carrying portion of the developing roller in the direction of the rotation axis; as well as (iii-iii) A second discharge port through which the air separated from the toner is discharged from the cyclone separation portion to the outside of the container.

17. The developing device according to claim 16, The cyclone separation part is arranged at the upper part of the container.

18. The developing device according to claim 16, wherein the first discharge port is disposed below an upper surface of an interior of the container constituting the toner accommodating space, and The second discharge port is arranged above the upper surface of the interior of the container.

19. The developing device according to any one of claims 16 to 18, The cyclone separation portion includes a conical portion formed integrally with the container.

20. An image forming device comprising: Photosensitive drum; a toner storage portion configured to store toner, the toner being supplied to the toner storage portion by using air; a developing roller configured to rotate about a rotation axis, the developing roller including a toner carrying portion configured to carry the toner stored in the toner storage portion and to supply the toner carried by the toner carrying portion to the photosensitive drum; as well as a cyclone separation portion including an inlet, a first discharge port communicating with the inside of the toner storage portion, and a second discharge port communicating with the outside of the toner storage portion, the cyclone separation portion being configured to receive air mixed with toner through the inlet, separate the toner and the air from each other, discharge the toner separated from the air through the first discharge port, and discharge the air separated from the toner through the second discharge port, The first discharge port is provided between positions of both ends of the toner carrying portion in the direction of the rotation axis.

21. The image forming apparatus according to claim 20, wherein the cyclone separation portion is provided on an upper surface portion of the toner storage portion, wherein the first discharge port is located below an upper surface of an interior of the toner storage portion, and The second discharge port is located above an upper surface of the toner storage portion.

22. The image forming apparatus according to claim 20 or 21, The inlet is opened in a direction from a center portion of the developing roller toward an end portion of the developing roller in the direction of the rotation axis of the developing roller.

Images