Image forming apparatus

Abstract

This provides one form of an image forming apparatus. [Solution] The device comprises a cartridge for containing toner, a device body to which the cartridge can be attached and detached, a pump unit for discharging air, a developing container including a toner storage section, and a tube for transporting the toner discharged from the cartridge along with the air to the toner storage section of the developing container. When the toner transport operation is being performed, the pressure of the pump unit, the pressure of the air chamber, the pressure of the toner chamber, and the pressure of the toner storage section are all above atmospheric pressure, the pressure of the toner chamber is greater than the pressure of the toner storage section, and the pressure of the air chamber is greater than the pressure of the toner chamber. When the toner transport operation is being performed, the pressure difference between the toner chamber and the air chamber in the first state, where toner is on only a part of the partition of the filter, is greater than the pressure difference between the toner chamber and the air chamber in the second state, where toner is not on the entire partition of the filter.

Description

[Technical Field]

[0001] This invention relates to an image forming apparatus that transports toner together with air. [Background technology]

[0002] Generally, electrophotographic image forming apparatuses form images by transferring a toner image formed on the surface of a photosensitive drum onto a transfer medium. Methods for replenishing the developer include, for example, the process cartridge system and the toner replenishment system. The process cartridge system integrates the photosensitive drum and the developer container into a single process cartridge, and when the developer runs out, the process cartridge is replaced with a new one.

[0003] On the other hand, the toner replenishment method is a method in which new toner is replenished into the developing container when the toner runs out. Conventionally, an image forming apparatus has been proposed that has a powder storage section for storing toner and a powder supply device capable of supplying toner to a toner hopper provided on the main body of the image forming apparatus (see Patent Document 1). The powder supply device has an air pump that discharges air into the powder storage section and a suction pump that sucks the toner stored in the powder storage section toward the toner hopper. [Prior art documents] [Patent Documents]

[0004] [Patent Document 1] Japanese Patent Publication No. 2007-249151 [Overview of the Initiative] [Problems that the invention aims to solve]

[0005] The present invention aims to provide an image forming apparatus that transports toner together with air. [Means for solving the problem]

[0006] One aspect of the present invention is an image forming apparatus comprising: a cartridge for containing toner; an apparatus body to which the cartridge can be attached and detached, comprising: a pump unit for discharging air; a developing container including a toner storage section for containing toner; and a tube for transporting toner discharged from the cartridge along with air to the toner storage section of the developing container, wherein the cartridge comprises: a toner chamber for containing toner; a filter configured to obstruct the passage of toner but allow the passage of air; an air chamber adjacent to the toner chamber via the filter, having an intake for taking in air discharged from the pump unit; an outlet for discharging the toner contained in the toner chamber to the outside of the cartridge; and a pipe configured to communicate with the outlet, through which the toner discharged from the outlet passes, wherein at least a portion of the toner chamber is in the direction of gravity of the air chamber The image forming apparatus has a partition that separates the toner chamber and the air chamber so as to be located above, and when a toner transport operation is performed in which toner in the toner chamber is discharged from the outlet and transported to the toner storage section via the tube by air discharged from the pump section and taken in from the intake of the cartridge, the pressure of the pump section, the pressure of the air chamber, the pressure of the toner chamber and the pressure of the toner storage section are greater than atmospheric pressure, the pressure of the toner chamber is greater than the pressure of the toner storage section, and the pressure of the air chamber is greater than the pressure of the toner chamber, and when the toner transport operation is performed, the pressure difference between the toner chamber and the air chamber in a first state in which toner is placed only on a part of the partition of the filter is greater than the pressure difference between the toner chamber and the air chamber in a second state in which no toner is placed on the entire surface of the partition of the filter.

[0007] Another aspect of the present invention is an image forming apparatus comprising: a cartridge for containing toner; an apparatus body to which the cartridge can be attached and detached, comprising: a pump unit for discharging air; a developing container including a toner storage section for containing toner; and a tube for transporting toner discharged from the cartridge along with air to the toner storage section of the developing container, wherein the cartridge comprises: a toner chamber for containing toner; a first filter configured to obstruct the passage of toner but allow the passage of air; an air chamber adjacent to the toner chamber via the first filter, having an intake for taking in air discharged from the pump unit; and a tube for transporting the toner contained in the toner chamber to the cartridge. The image forming apparatus is characterized by having an outlet for discharging to the outside of the cartridge, and a pipe configured to communicate with the outlet through which the toner discharged from the outlet passes, wherein the toner in the toner chamber is discharged from the outlet and transported to the toner storage section via the tube by air discharged from the pump section and taken in from the intake of the cartridge, the developing container is provided with an opening for communicating the toner storage section with the outside of the developing container, the developing container has a second filter configured to cover the opening and prevent the passage of toner but allow the passage of air, and the air permeability of the first filter is smaller than that of the second filter. [Effects of the Invention]

[0008] According to the present invention, one form of an image forming apparatus can be provided. [Brief explanation of the drawing]

[0009] [Figure 1] A schematic diagram showing an image forming apparatus according to the first embodiment. [Figure 2] A cross-sectional view showing a process cartridge. [Figure 3] (a) is a cross-sectional view showing a toner cartridge with the sealing member open, and (b) is a cross-sectional view showing a toner cartridge with the sealing member closed. [Figure 4] Perspective view showing a toner cartridge cut in the XY plane. [Figure 5] Exploded perspective view showing a toner cartridge cut in the XY plane. [Figure 6] Perspective view showing a filter. [Figure 7] Enlarged view showing the joint portion of the first frame body and the second frame body. [Figure 8] Bottom view showing the first frame body. [Figure 9] Cross-sectional view showing the state where the toner cartridge is connected to the developing container through a passage. [Figure 10] Graph showing the pressure of each part when the pressure generated by the pump is transmitted from the toner cartridge to the process cartridge. [Figure 11] (a) is a cross-sectional view showing the state where the discharge of toner has not started, (b) is a cross-sectional view showing the state where the discharge of toner has started by the air taken in from the intake port. (c) is a cross-sectional view showing the state where the toner has been further discharged from the state of Fig. 10(b), (d) is a cross-sectional view showing the state where a part of the inclined portion of the filter is exposed. [Figure 12] Table showing whether toner can be transported according to each condition. [Figure 13] Graph showing the relationship between the pump flow rate and the pressure difference between the air chamber and the toner chamber.

Embodiments for Carrying Out the Invention

[0010] Hereinafter, embodiments for carrying out this invention will be exemplarily and detailedly described based on examples with reference to the drawings. However, the dimensions, materials, shapes, relative arrangements, etc. of the components described in this embodiment should be appropriately changed according to the configuration of the device to which the invention is applied and various conditions. That is, it is not intended to limit the scope of this invention to the following embodiments.

[0011] In the following description, examples of the image forming apparatus include a copying machine, a printer, a multifunction peripheral, a commercial printing apparatus, and the like. In such an image forming apparatus, an image is formed on a recording material based on image information input from an external device or image information read from a document. In addition, in the image forming apparatus, in addition to the main body having an image forming function, an optional feeder, an image reading device, a sheet processing device, and other attached devices may be connected. However, the entire system to which such attached devices are connected is also a kind of image forming apparatus. The recording materials include papers such as plain paper and thick paper, plastic films, coated papers, sheets of special shapes such as envelopes and index papers, and sheet materials of various materials and shapes such as cloth.

[0012] 〔Overall Configuration〕 The image forming apparatus IF according to the present embodiment is an electrophotographic monochrome laser beam printer. As shown in FIG. 1, the image forming apparatus IF has an image forming unit 50 that forms an image on a sheet P, a feeding unit 60, a fixing unit 9, and a discharge roller pair 5c. The image forming unit 50 includes a process cartridge B and a scanner unit 3. The scanner unit 3 is disposed above the process cartridge B. Note that, instead of the scanner unit 3, an LED exposure unit having an LED array in which a plurality of LEDs are arranged along the longitudinal direction of the photosensitive drum 1 may be applied.

[0013] Note that, the portion excluding the process cartridge B and a toner cartridge C described later from the image forming apparatus IF may be referred to as the main body of the image forming apparatus IF or the apparatus main body 100. In the following description, the toner cartridge C may be simply referred to as the cartridge C. The process cartridge B may be detachably supported with respect to the apparatus main body 100, or may be fixedly attached to the apparatus main body 100 in a non-detachable manner.

[0014] Furthermore, in the following explanation, unless otherwise specified, it is assumed that process cartridge B and toner cartridge C are in their normal position, that is, the position in which they are mounted on the main unit 100 of the device, and the directions (X, Y, Z) are defined as follows.

[0015] As shown in Figure 1, the front-to-back direction is indicated by the X-axis, and the direction from the back to the front of the image forming apparatus IF is defined as the X-direction. The X-direction is sometimes referred to as the front direction or the direction towards the viewer. In addition, the downstream side in the X-direction of the image forming apparatus IF is sometimes referred to as the front side, and the upstream side as the back side.

[0016] The left-right direction is indicated by the Z-axis, and the direction from left to right in the image forming apparatus IF is defined as the Z-direction. The Z-direction is sometimes referred to as the right direction. Additionally, the downstream side and the upstream side in the Z-direction of the image forming apparatus IF are sometimes referred to as the right side and left side, respectively.

[0017] The vertical direction is indicated by the Y-axis, and the direction from the bottom to the top of the image forming apparatus IF is defined as the Y-direction. The Y-direction may also be called the upward direction, height direction, or vertical direction. Furthermore, the downstream side in the Y-direction of the image forming apparatus IF may be called the upper side, top surface side, or top surface side, while the upstream side may be called the lower side, bottom surface side, or bottom surface side.

[0018] The X, Y, and Z axes are perpendicular to each other. For example, the X axis is perpendicular to both the Y axis and the Z axis. The plane perpendicular to the X axis is sometimes called the YZ plane, the plane perpendicular to the Y axis is called the ZX plane, and the plane perpendicular to the Z axis is called the XY plane. For example, the XZ plane is a horizontal plane. The X and Z directions are directions along the horizontal XZ plane, i.e., horizontal directions.

[0019] Process cartridge B includes a photosensitive drum 1, a developing roller 2, a charging roller 11, and a developing container 12 which includes a toner storage section 12a for storing toner supplied to the developing roller 2. The photosensitive drum 1 is constructed by coating the outer circumference of an aluminum cylinder with an organic photoconductive layer and is rotated by a drive motor (not shown). A photosensitive belt may be used instead of the photosensitive drum 1.

[0020] Furthermore, the image forming unit 50 has a transfer roller 7 that contacts the developing roller 2 of the process cartridge B and forms the transfer portion Nt. The transfer roller 7 contacts the photosensitive drum 1 of the process cartridge B and forms the transfer portion Nt.

[0021] The fixing unit 9 includes a heating roller 9a that is heated by a heater and a pressure roller 9b that presses against the heating roller 9a. Alternatively, instead of the heating roller 9a, a fixing film that rotates while rubbing against the heater or a fixing belt having a conductive layer that is heated by electromagnetic induction may be used.

[0022] The feeding unit 60 is located at the bottom of the image forming apparatus IF. The feeding unit 60 includes a tray 4 that can be pulled out and attached to the apparatus body 100, and a feeding roller 5a that feeds the sheet P contained in the tray 4.

[0023] The main body 100 of the device is detachably supported by a toner cartridge C. The toner cartridge C contains toner T that can be supplied to the toner storage section 12a of the developing container 12 of the process cartridge B.

[0024] [Image Formation Process] Next, the image forming operation of the image forming apparatus IF configured in this way will be described. When an image signal is input to the scanner unit 3 from a personal computer (not shown), the scanner unit 3 irradiates a laser beam L corresponding to the image signal onto the photosensitive drum 1 of each process cartridge B.

[0025] At this time, the surface of the photosensitive drum 1 is uniformly charged to a predetermined polarity and potential by the charging roller 11, and an electrostatic latent image is formed on the surface when laser light L is irradiated from the scanner unit 3. The electrostatic latent image formed on the photosensitive drum 1 is developed by the developing roller 2, and a toner image is formed on the photosensitive drum 1.

[0026] In parallel with this image formation process, the sheet P contained in the tray 4 of the feeding unit 60 is transported toward the transfer unit Nt. In the transfer unit Nt, the toner image on the photosensitive drum 1 is transferred to the sheet P by a secondary transfer bias applied to the transfer roller 7. After the toner image is transferred to the sheet P, any toner remaining on the surface of the photosensitive drum 1 is removed by a cleaning device (not shown).

[0027] The sheet P onto which the toner image has been transferred is subjected to predetermined heat and pressure by the heating roller 9a and pressure roller 9b of the fixing unit 9, causing the toner to melt and solidify (fix) to the sheet. After passing through the fixing unit 9, the sheet P is discharged in the direction along the X direction by the discharge roller pair 5c and loaded onto the discharge tray 10 located on the top of the main body 100 of the device.

[0028] [Processing cartridge] Next, we will describe process cartridge B in more detail using Figure 2. Figure 2 is a cross-sectional view showing process cartridge B. Process cartridge B only needs to have a photosensitive drum 1 and process means that act on the photosensitive drum 1. In this embodiment, the process means includes a charging roller 11, a developing roller 2, a developing blade 15, and a cleaning blade 14.

[0029] Furthermore, process cartridge B is composed of a drum unit as an image carrier unit and a developing unit as a developing means. The drum unit has a charging roller 11 located around the photosensitive drum 1 and an elastic cleaning blade 14. The developing unit has a developing roller 2, a developing blade 15, a supply roller 6, a developing container 12 including a toner storage section 12a for storing toner T, and a stirring member 13.

[0030] The stirring member 13 has a rotating shaft 13a and a flexible stirring sheet 13b fixed to the rotating shaft 13a, and stirs the toner T contained in the toner storage section 12a by rotating. The developing container 12 is provided with a passage 24 through which the toner supplied from the toner cartridge C passes, a receiving port 24a for receiving the supplied toner, and an opening 26 for allowing air inside the toner storage section 12a to pass to the outside of the developing container 12. In the orientation when the image forming apparatus IF is in use, the receiving port 24a and the opening 26 are located at the top of the developing container 12, and the opening 26 is covered by a filter 26a as a second filter. In this embodiment, the opening 26 is composed of a through hole, connecting the inside of the toner storage section 12a to the outside of the developing container 12. The filter 26a is composed of a porous material, for example, resin fibers. The holes in the filter 26a are sized and dense enough to allow the passage of air but restrict the passage of toner T. In other words, filter 26a is configured to allow air to pass through but to prevent toner T from passing through.

[0031] [Toner cartridge general configuration] Next, the schematic configuration of the toner cartridge C will be described using Figures 3(a) to 3(8). Figure 3(a) is a cross-sectional view showing the toner cartridge C with the sealing member 30 open, and Figure 3(b) is a cross-sectional view showing the toner cartridge C with the sealing member 30 closed. Figure 4 is a perspective view showing the toner cartridge C cut in the XY plane. Figure 5 is an exploded perspective view showing the toner cartridge C cut in the XY plane. Figure 6 is a perspective view showing the filter 18. Figure 7 is an enlarged view showing the joint portion of the first frame 32 and the second frame 31. Figure 8 is a bottom view showing the first frame 32.

[0032] The image forming apparatus IF has a front door (not shown) that is supported by the housing of the apparatus body 100 so as to be openable and closable. When the front door is in the closed position, it covers the opening provided at the front of the apparatus body 100, i.e., the downstream end in the X direction. When the front door is in the open position, it opens the opening of the apparatus body 100. The front door can maintain its position when in the open position.

[0033] When the front door is opened from the closed position to the open position, the toner cartridge C is exposed to the outside of the image forming apparatus IF through the opening. This allows the user to access the toner cartridge C.

[0034] The toner cartridge C is located on the downstream side of the device body 100 in the X direction, i.e., on the front side of the device body 100. In other words, the toner cartridge C is located on the downstream side of the device body 100 in the sheet discharge direction of the discharge roller pair 5c.

[0035] The toner cartridge C is detachably supported in the X direction relative to the main unit 100. Therefore, the toner cartridge C can be replaced without removing the process cartridge B from the main unit 100. The toner cartridge C is located on the front side of the main unit 100 and is exposed by opening the front door, allowing for easy replacement.

[0036] In the following explanation, unless otherwise specified, it is assumed that the toner cartridge C assumes the orientation described below, and the directions (X, Y, Z) are defined as shown in Figures 3(a) to 11(d). That is, the explanation assumes that the toner cartridge C assumes an orientation in which the toner chamber 16, filter 18, and air chamber 17 are arranged in that order from top to bottom with respect to the direction of gravity G (opposite to the Y direction; see Figure 3(a)), and that the toner cartridge C assumes an orientation in which the short direction (Z direction) and long direction (X direction) of the toner cartridge C are parallel to the horizontal direction perpendicular to the direction of gravity G.

[0037] In this orientation, the direction opposite to the Y direction is the direction of gravity, and the toner cartridge C is oriented in a predetermined direction where at least a part of the toner chamber 16 is above the air chamber 17. In this case, the short side of the toner cartridge C is the Z direction, the long side is the X direction, and the direction opposite to the direction of gravity is the Y direction. That is, the direction of gravity G is the direction in which the second frame 31 and the first frame 32, which will be described later, are aligned. In other words, the direction of gravity G is the direction in which the toner chamber 16 and the air chamber 17 are aligned. The X direction is the long side of the toner cartridge C when viewed in the direction of gravity G. The Z direction is the short side of the first frame 32 that intersects both the X and Y directions, and is also the long side of the developing container 12.

[0038] The front-to-back direction of toner cartridge C is indicated by the X-axis, with the direction from the back to the front being defined as the X-direction. The X-direction is sometimes referred to as the front direction or the direction towards the viewer. Additionally, the downstream side of toner cartridge C in the X-direction is sometimes referred to as the front side, and the upstream side as the back side.

[0039] The left-right direction of toner cartridge C is indicated by the Z-axis, and the direction from left to right of toner cartridge C is defined as the X-direction. The Z-direction is sometimes referred to as the right direction. Additionally, the downstream side of toner cartridge C in the Z-direction is sometimes referred to as the right side, and the upstream side as the left side.

[0040] The vertical direction of toner cartridge C is indicated by the Y-axis, and the direction from the bottom to the top of toner cartridge C is defined as the Y-direction. The Y-direction may also be called the upward direction, height direction, or vertical direction. Furthermore, the downstream side of toner cartridge C in the Y-direction may be called the upper side, top surface side, or top surface side, while the upstream side may be called the lower side, bottom surface side, or bottom surface side.

[0041] As shown in Figures 3(a) to 5, the toner cartridge C includes a first frame 32 as a first container, a second frame 31 as a second container, a filter 18, and a discharge pipe 27 as a pipe. In this embodiment, the first frame 32 and the second frame 31 are made of resin material, but they may be made of paper or the like. As will be described in detail later, the filter 18 is held in a state sandwiched between the first frame 32 and the second frame 31.

[0042] The internal space of the toner cartridge C is divided into a toner chamber 16 and an air chamber 17 by a filter 18. Specifically, the toner chamber 16 is composed of a first frame 32 and a filter 18, and the air chamber 17 is composed of a second frame 31 and a filter 18. The air chamber 17 is located below the filter 18, and the toner chamber 16 is located above the filter 18. In other words, the air chamber 17 is adjacent to the toner chamber 16 via the filter 18. There are no partitions within the air chamber 17, and it is the only chamber (room, space) adjacent to the toner chamber 16 via the filter 18.

[0043] The toner chamber 16 is configured to contain toner T, which is supported by gravity by the filter 18 within the toner chamber 16. The air chamber 17 does not contain toner T. The filter 18 is made of a porous material, for example, resin fibers. The pores of the filter 18 are of a size and density that allows air to pass through but restricts the passage of toner T. In other words, the filter 18, as the first filter, is configured to allow air to pass through but to prevent the passage of toner T.

[0044] The back of the first frame 32 is provided with an outlet 16a through which toner in the toner chamber 16 is discharged to the outside of the toner cartridge C. In other words, the toner chamber 16 is provided with an outlet 16a. The outlet 16a is made up of a through hole that penetrates the first frame 32 in the X direction. The bottom surface 31d of the second frame 31 is provided with an intake 20 made up of a through hole that penetrates the second frame 31 in the Y direction. In other words, the air chamber 17 is provided with an intake 20. The outlet 16a and the intake 20 are connected to the outside of the toner cartridge C.

[0045] As shown in Figure 1, the main body 100 of the image forming apparatus IF includes a pump 35 as a pump unit and an air supply pipe 21. The air supply pipe 21 connects the pump 35 to the inlet 20 of the toner cartridge C, and the pump 35 is configured to supply air to the air chamber 17 of the toner cartridge C via the air supply pipe 21. The pump 35 is located below the toner cartridge C. The pump 35 is composed of, but is not limited to, a positive displacement pump such as a reciprocating pump or a rotary pump. For example, the pump 35 may be composed of a non-positive displacement pump such as a centrifugal pump, a propeller pump, or a viscous pump.

[0046] Reciprocating pumps are pumps that perform suction and discharge by the reciprocating motion of a piston or plunger, and include piston pumps, plunger pumps, and diaphragm pumps. Rotary pumps are pumps that perform suction and discharge by the rotational motion of gears or rotors, and include gear pumps, screw pumps, and vane pumps. Pump 35 in this embodiment is composed of a diaphragm pump as an example.

[0047] In this embodiment, the pump 35 was connected to the intake 20 via the air supply pipe 21, but this is not limited to this configuration. For example, the pump 35 may be directly connected to the intake 20 of the toner cartridge C, or it may be connected to the intake 20 via a passage formed by the frame of the device body 100 or the like.

[0048] Furthermore, in this embodiment, the pump 35 is provided on the main body 100 of the device, but it may also be provided on the toner cartridge C or the process cartridge B, respectively.

[0049] Furthermore, the discharge port 16a provided on the first frame 32 of the toner cartridge C opens toward the upstream direction in the X direction. Therefore, when the toner cartridge C is mounted on the device body 100 facing toward the upstream direction in the X direction, it is easier to engage the discharge port 16a with the passage 24.

[0050] In addition to the arrangement described above, the discharge port 16a may be provided on the bottom surface 31d or top surface of the toner cartridge C, and the intake port 20 may be provided on the back or top surface of the toner cartridge C. Furthermore, if there is sufficient space in the main body 100 of the device, the discharge port 16a and the intake port 20 may be provided on both the left and right sides of each side of the toner cartridge C.

[0051] Furthermore, the first frame 32 of the toner cartridge C supports a sealing member 30 that seals the discharge port 16a, so that it can rotate around a pivot axis 30a. When the toner cartridge C is not mounted on the device body 100 and the discharge port 16a of the toner cartridge C is not connected to the passage 24, the sealing member 30 is in the closed position shown in Figure 3(a). In the closed position, the sealing member 30 seals the discharge port 16a, preventing toner in the toner chamber 16 from leaking to the outside of the toner cartridge C.

[0052] On the other hand, when the toner cartridge C is mounted on the device body 100 and the outlet 16a of the toner cartridge C is connected to the passage 24 which acts as a tube, the sealing member 30 is in the open position shown in Figure 3(b). In the open position, the sealing member 30 opens the outlet 16a, allowing toner T to be supplied from the toner cartridge C to the process cartridge B via the passage 24. Note that the sealing member 30 is not limited to an opening / closing member as in this embodiment, but may also be composed of, for example, a seal that can be peeled off from the toner cartridge C, or a sliding member that can slide.

[0053] As shown in Figures 3(a) to 5, the first frame 32 has a first box portion that forms the toner chamber 16, and a first flange portion 32a that extends substantially horizontally from the lower end of the first box portion toward the outside of the toner chamber 16. The first box portion is formed in a substantially rectangular parallelepiped shape. The first flange portion 32a is formed around the entire circumference of the lower end of the first box portion.

[0054] Furthermore, as shown in Figure 8, a plurality of ribs 32d are provided on the inner wall of the first box portion of the first frame 32. The plurality of ribs 32d extend inward into the toner chamber 16, corresponding to the region where the second flange portion 31a of the second frame 31 is formed. The plurality of ribs 32d face the second flange portion 32a of the second frame 31 in the Y direction.

[0055] The second frame 31 is formed separately from the first frame 32 and has a second box portion that forms the air chamber 17, and a second flange portion 31a that extends substantially horizontally from the upper end of the second box portion toward the outside of the air chamber 17. The second flange portion 31a is formed around the entire circumference of the upper end of the second box portion.

[0056] As shown in Figures 3(a) to 6, the filter 18 has a bottom portion 18e that separates the air chamber 17 and the toner chamber 16, and an outer edge portion 18a that is sandwiched and held by a first flange portion 32a and a second flange portion 31a. The bottom portion 18e is composed of a plurality of inclined portions 18c that are formed to slope downward in the direction of gravity G as they approach the lowest part 18b of the filter 18, and constitutes the bottom surface of the toner chamber 16. The lowest part 18b is located in the center of the filter 18 in the X and Z directions. In other words, the filter 18 has a bottom portion 18e that acts as a partition separating the toner chamber 16 and the air chamber 17 such that at least a part of the toner chamber 16 is located above the air chamber 17 in the direction of gravity G.

[0057] The filter 18 is made of a filter material formed by, for example, a heat press, or a fibrous sheet material. The filter 18 is formed from a single continuous component, and the bottom surface 18e of the filter 18 is configured to be parallel to the shape of the bottom surface of the second frame 31. The toner T in the toner chamber 16 rests on the bottom surface 18e of the filter 18.

[0058] The frame of the toner cartridge C is constructed such that the first flange portion 32a and the second flange portion 31a are joined together by ultrasonic welding, preventing air from leaking between them. The first flange portion 32a and the second flange portion 31a may be fixed to each other not only by ultrasonic welding, but also by heat welding, adhesives such as double-sided tape or hot melt, or screws.

[0059] The first flange portion 32a and the second flange portion 31a are joined together, so that the outer edge portion 18a of the filter 18 and the sealing member 34 are sandwiched between the multiple ribs 32d of the first frame 32 and the second flange portion 31a. The sealing member 34 is made of a flexible material such as rubber or silicone. In this way, the filter 18 is held in place by being sandwiched between the first frame 32 and the second frame 31 together with the sealing member 34. If the holding force of the filter 18 is insufficient, the entire circumference of the outer edge portion 18a of the filter 18 may be bonded to at least one of the first flange portion 32a and the second flange portion 31a. This allows the filter 18 to be held with high holding force. The sealing member 34 may also be omitted.

[0060] Inside the toner chamber 16, a cylindrical discharge pipe 27 is arranged as shown in Figures 3(a) to 5. The discharge pipe 27 has an inlet 27a that opens downward in the direction of gravity G, and an outlet 27b that opens backward, i.e., upstream in the direction of X, and communicates with the discharge port 16a of the toner cartridge C, and communicates with the outside of the toner cartridge C. The outlet 27b is connected to the discharge port 16a and is located above the inlet 27a. The discharge pipe 27 has a first pipe section with an inlet 27a that extends in the direction of Y or the direction of gravity G, and a second pipe section with an outlet 27b that is connected to the discharge port 16a and extends in the direction of X, and is bent in the middle. In this way, the discharge pipe 27 connects the inlet 27a and the outlet 27b. The inlet 27a, which is the end of the discharge pipe 27 opposite to the outlet 27b, is positioned to face the lowest part 18b, which is part of the filter 18, with a gap in the direction of gravity G. The discharge pipe 27 is appropriately constructed from a flexible tube made of a resin material such as rubber or a silicone material, or from a hollow member made of a resin or metal pipe.

[0061] As shown in Figures 4 and 8, support portions 32b and 32c extend from the inner circumferential surface of the first frame 32. Support portion 32b extends in the -Y direction (gravity direction G) from the inner circumferential surface on the upper side of the first frame 32, and support portion 32c extends in the X direction from the inner circumferential surface on the back side of the first frame. These support portions 32b and 32c support the portion of the discharge pipe 27 near the inlet 27a and the portion near the outlet 27b, respectively. Note that the support portions 32b and 32c may be molded integrally with the first box portion of the first frame 32 during the molding of the first frame 32, or they may be constructed separately from the first box portion.

[0062] [Toner transport mechanism] Next, using Figures 1, 3(a)(b), and 9, the mechanism by which toner contained in the toner chamber 16 of toner cartridge C is transported to the developing container 12 of process cartridge B will be explained. Figure 9 is a cross-sectional view showing how toner cartridge C is connected to the developing container 12 via the passage 24. As shown in Figures 1 and 9, air discharged from the pump 35 is taken into the air chamber 17 via the air supply pipe 21 and the intake 20 of toner cartridge C. This air then fills the air chamber 17, passes through the filter 18, and flows into the toner chamber 16.

[0063] Air flowing into the toner chamber 16 penetrates between the toner particles T, causing the toner T to become fluid. The influx of air from the pump 35 creates positive pressure inside the toner cartridge C, and the air attempts to exit the toner cartridge C through the discharge pipe 27 and the discharge port 16a. At this time, the toner T in the toner chamber 16 is moved along with the air through the discharge pipe 27 and discharged to the outside of the toner cartridge C through the discharge port 16a. In other words, the discharge pipe 27 guides the toner in the toner chamber 16 along with the air from the inlet 27a to the discharge port 16a.

[0064] As in this embodiment, by providing an air chamber 17, which is a highly sealed space, between the pump 35 and the filter 18, the air discharged from the pump 35 is efficiently directed to the filter 18 without being dispersed outside the toner cartridge C. For example, in situations where the toner T in the toner chamber 16 agglomerates, such as when the toner cartridge C is subjected to vibration or left unattended for a long time, the pressure required to allow air to flow into the toner chamber 16 through the filter 18 may be high. Even in this case, by continuously supplying air from the pump 35 to the air chamber 17 and increasing the pressure (atmospheric pressure) in the air chamber 17, it becomes possible to supply air to the toner chamber 16 through the filter 18. Furthermore, by providing the air chamber 17, it is sufficient for the pump 35 to generate enough pressure to continue supplying air into the air chamber 17 until the pressure required for air to pass from the filter 18 into the toner chamber 16 is reached. Therefore, it becomes possible to use a small pump for the pump 35, contributing to the miniaturization of the device.

[0065] Furthermore, in this embodiment, the air taken in from the intake port 20 of the toner cartridge C has only one outlet, the discharge port 16a. As a result, the airflow within the toner cartridge C is stable, and the toner T contained in the toner chamber 16 can be stably discharged to the outside of the toner cartridge.

[0066] Furthermore, by not providing any vents or outlets inside the toner cartridge C except for one outlet 16a, it is possible to stably discharge the toner T using only the power of the pump 35 that discharges air toward the intake 20. When multiple air outlets are provided, it becomes difficult to manage the flow of toner and air, so in order to stably transport the toner, it may be necessary to have a configuration that sucks up the toner and air and discharges them to the outside of the toner cartridge C. With the configuration of this embodiment, it is possible to stably discharge the toner T without having to provide a separate pump to suck up air, so that stably transporting the toner T can be achieved with a simpler configuration.

[0067] The toner T discharged from the discharge port 16a is supplied to the upstream end of the developing container 12 in the Y direction via the passage 24. Here, as shown in Figure 2, a stirring member 13 for stirring the toner inside the developing container 12 is rotatably provided in the toner storage section 12a of the developing container 12.

[0068] The toner in the toner storage section 12a is leveled by the rotation of the stirring member 13. In this embodiment, the stirring member 13 consists of a rotating shaft 13a and a stirring sheet 13b fixed to the rotating shaft 13a, but it is not limited to this configuration. For example, the stirring member 13 may consist of a screw configured to transport the toner in the toner storage section 12a of the developing container 12 along the Z direction.

[0069] Since air as well as toner T flows into the developing container 12, the internal pressure inside the developing container 12 increases. Therefore, in this embodiment, as shown in Figures 3(a)(b) and 9, an opening 26 is provided on the top surface of the developing container 12, and this opening 26 is covered by a filter 26a. As a result, the toner that flows into the developing container 12 is restricted from being discharged to the outside by the filter 26a and remains inside the developing container 12. On the other hand, at least a portion of the air that flows into the developing container 12 passes through the filter 26a and is discharged to the outside of the developing container 12. This suppresses the rise in internal pressure of the developing container 12 and allows for smooth replenishment of toner to the developing container 12.

[0070] As described above, the toner contained in the toner cartridge C is transported to the developing container 12 along with air and replenished in the developing container 12. By transporting the toner using air, the design flexibility of the toner transport path is increased, and since components such as screws for transporting the toner are not required, the number of parts can be reduced, and costs can be lowered.

[0071] Furthermore, as described above, the inlet 27a of the discharge pipe 27 is positioned opposite the lowest part 18b of the filter 18 with a gap between them. Since the filter 18 is held in a downward-sloping position toward the lowest part 18b, when the amount of toner remaining in the toner chamber 16 becomes low, the toner, which has been fluidized by the air, moves along the slope of the filter 18 and collects at the lowest part 18b. In other words, the toner in the toner chamber 16 can be guided toward the inlet 27a of the discharge pipe 27.

[0072] Therefore, even when the amount of toner remaining in the toner chamber 16 becomes low, the toner that has accumulated at the bottom 18b can be efficiently discharged from the inlet 27a of the discharge pipe 27 through the outlet 16a to the outside of the toner cartridge C. The outlet 16a is located above the inlet 27a and the bottom surface 18e of the filter 18, but the toner is transported from the inlet 27a to the outlet 16a by air. Thus, the amount of toner that remains in the toner chamber 16 without being replenished can be reduced.

[0073] [Relationship of pressure in each part during toner transport] Next, using Figure 10, we will explain the pressure at each part of the transport path when toner is being transported from the toner cartridge C to the developing container 12 by air supplied by the pump 35. In the toner transport operation, the toner in the toner chamber 16 is discharged from the outlet 16a and transported to the toner storage section 12a via the passage 24 by air discharged from the pump 35 and taken in from the intake 20 of the toner cartridge C. Figure 10 is a graph showing the pressure at each part as the pressure generated by the pump 35 is transmitted from the toner cartridge C to the process cartridge B.

[0074] As shown in Figure 10, the pressure P1 generated by the pump 35 is slightly reduced to pressure P2 in the air chamber 17 of the toner cartridge C as it passes through the air supply pipe 21. Then, the pressure decreases by the amount of pressure loss when the air passes through the filter 18, and the pressure in the toner chamber 16 becomes pressure P3. Furthermore, the pressure decreases by the amount of pressure loss when air and toner pass through the passage 24 from the toner chamber 16, and the pressure in the toner storage section 12a of the developing container 12 of the process cartridge B becomes pressure P4.

[0075] The developing container 12 of process cartridge B is connected to the outside of the developing container 12 by an opening 26, so the pressure inside the developing container 12 can be maintained at a value close to atmospheric pressure. In this way, the toner cartridge C and process cartridge B are pressurized by the pump 35 so that the pressure is always increasing. The pressure P1 applied to the pump 35 is the pressure P4 of the developing container 12 plus the pressure loss when air and toner T pass through the passage 24 (P4-P3), the pressure loss when air passes through the filter 18 (P3-P2), and the pressure loss when air passes through the air supply pipe 21 (P2-P1). Note that by placing the pump 35 and the toner cartridge C in close proximity and omitting or shortening the air supply pipe 21 between the pump 35 and the toner cartridge C, the pressure loss in the air supply pipe 21 can be ignored.

[0076] [Changes in toner ejection status] Figures 11(a) to 11(d) are cross-sectional views illustrating the changes in the discharge state when toner T contained in the toner chamber 16 is discharged from the toner cartridge C. Figure 11(a) is a cross-sectional view showing the state in which toner T discharge has not yet begun, and Figure 11(b) is a cross-sectional view showing the state in which toner T discharge has begun due to air taken in from the intake port 20. Figure 11(c) is a cross-sectional view showing the state in which toner T has been discharged further from the state in Figure 11(b), and Figure 11(d) is a cross-sectional view showing the state in which the inclined portion 18c of the filter 18 is partially exposed.

[0077] As shown in Figure 11(a), when air is pumped from the intake 20 into the air chamber 17 of the toner cartridge C by the pump 35, the air flows through the filter 18 and discharge pipe 27 towards the discharge port 16c, which is the only outlet of the toner cartridge C. At this time, the air flows with the toner T, so the toner T enters the intake 27a with the air and is then transported through the discharge pipe 27 towards the discharge port 16a, and discharge from the discharge port 16a begins. As a result, the amount of toner T contained in the toner chamber 16 decreases, and the state transitions from Figure 11(a) to Figure 11(b).

[0078] As shown in Figure 11(b), when the amount of toner T in the toner chamber 16 decreases due to the discharge of toner T, the surface level of the toner T near the inlet 27a drops with respect to gravity. As a result, the toner T contained in the toner chamber 16 begins to collapse from around the inlet 27a. At this time, the toner T is fluidized by the inflow of air that has passed through the filter 18, and the toner T is transported along the slope of the inclined section 18c toward the lowest point 18b. As long as the inflow of air from the intake 20 continues, the toner T near the lowest point 18b enters the discharge pipe 27 through the inlet 27a, passes through the discharge pipe 27 with the air, and is then discharged from the outlet 16a. If the discharge of toner T continues, the surface level of the toner T contained in the toner chamber 16 will drop further, transitioning from the state in Figure 11(b) to the state in Figure 11(c) and then to the state in Figure 11(d).

[0079] As shown in Figure 11(d), as the amount of toner T in the toner storage section 12a decreases, a portion of the inclined section 18c of the filter 18 becomes exposed. In this state, the air discharged from the pump 35 is set to blow out from the entire bottom surface 18e of the filter 18, regardless of the presence or absence of toner on the filter 18, by adjusting the air permeability of the filter 18 and the pump flow rate as described later.

[0080] [Relationship between filter airflow and pump flow rate] Next, the required airflow rate of the filter 18 and the pump flow rate for the toner T in the toner chamber 16 to be fluidized by the air that has passed through the filter 18 will be explained using Figures 12 and 13. Figure 12 is a table showing whether or not toner can be transported under each condition. Figure 13 is a graph showing the relationship between the pump flow rate and the pressure difference between the air chamber 17 and the toner chamber 16.

[0081] The air permeability of the filter 18 provided in the toner cartridge C is [cm]. 3 / (cm 2 It is expressed in units of (cm²) and indicates the airflow rate passing through filter 18 per unit area when air is drawn in to a pressure of 125 [Pa]. For example, air permeability can be measured by Method A (Fragile method) as defined in the JIS air permeability test (L1096). In Method A (Fragile method), first, five test pieces of approximately 200 [mm] x 200 [mm] are taken. Next, the test pieces are attached to a Frazier type testing machine, air is drawn in to a pressure of 125 [Pa], and the airflow rate at that time is measured. Then, from the measured airflow rate and test area, the air permeability [cm²] is calculated. 3 / (cm 2 ·s) is required.

[0082] A filter with a low air permeability can be considered as a filter having a small opening area per unit area. Therefore, when the same flow rate of air is blown onto a filter with a low air permeability and a filter with a high air permeability, the flow velocity at the opening of the filter with a low air permeability becomes higher. For this reason, in order to lift and fluidize toner T that settles in the filter due to its own weight, such as the toner in the toner chamber 16, by the buoyancy of the air flow velocity, a filter with a low air permeability is more advantageous. Also, in the case of a filter with a low air permeability, even a pump 35 with a small flow rate can fluidize the toner T in the toner chamber 16.

[0083] In FIG. 12, for a filter 18 with an air permeability of 0.9 [cm 3 / (cm 2 ·s)], the result of judging the possibility of toner conveyance from the ratio of the air flow rate through the filter 18 and the pump flow rate is shown. In FIG. 12, the area of the filter 18 is changed as in conditions 1 to 4.

[0084] That is, in condition 1, the filter area is 202 [cm 2 , and the air flow rate through the filter 18 is 171.7 [cc / sec]. The air flow rate through the filter 18 is obtained from the air permeability of the filter 18 and the filter area. In condition 2, the filter area is 72 [cm 2 , and the air flow rate through the filter 18 is 61.2 [cc / sec]. In condition 3, the filter area is 47 [cm 2 , and the air flow rate through the filter 18 is 40.0 [cc / sec]. In condition 4, the filter area is 15 [cm 2 , and the air flow rate through the filter 18 is 12.8 [cc / sec].

[0085] Figure 12 shows whether toner transport is possible when the pump flow rate is 6 [cc / sec] and 25 [cc / sec] for each of conditions 1 to 4. The feasibility of toner transport indicates whether the toner T in the toner chamber 16 of the toner cartridge C can be transported through the passage 24 to the toner storage section 12a of the developing container 12 of the process cartridge B by the drive of the pump 35 during toner transport operation.

[0086] As shown in Figure 12, it was found that toner transport becomes possible when the filter 18 and pump 35 are selected so that the pump flow rate is 10% or more of the air permeable capacity of the filter 18. In other words, for toner to be transported to the developing container 12 by the air supplied from the pump 35, the pump flow rate must be 10% or more of the air permeable capacity of the filter 18.

[0087] Next, the influence of the air permeability of the filter 18 and the pump flow rate on the pressure difference between the air chamber 17 and the toner chamber 16 (hereinafter simply referred to as the pressure difference ΔP) will be explained using Figure 13. The horizontal axis of Figure 13 represents the pump flow rate, and the vertical axis of Figure 13 represents the pressure difference ΔP. Line P11 in Figure 13 shows the relationship between the pump flow rate and the pressure difference ΔP when the pump 35 is driven with no toner T on the entire bottom surface 18e of the filter 18, which has low air permeability (hereinafter referred to as the toner-free state). Line P21 shows the relationship between the pump flow rate and the pressure difference ΔP when the pump 35 is driven with no toner T on the bottom surface 18e of the filter 18, which has high air permeability. Line P12 shows the relationship between the pump flow rate and the pressure difference ΔP when the pump 35 is driven with toner T on the entire bottom surface 18e of the filter 18, which has low air permeability (hereinafter referred to as the toner-present state). Linear curve P22 shows the relationship between the pump flow rate and the pressure difference ΔP when the pump 35 is driven with toner T covering the entire bottom surface 18e of the highly permeable filter 18.

[0088] As can be seen from the lines P11, P12, P21, and P22, the pressure difference ΔP increases as the pump flow rate increases. Also, as can be seen from line P11, the pressure difference ΔP when using a filter 18 with low air permeability and a pump 35 with a pump flow rate X1 is value P111. And, as can be seen from line P21, the pressure difference ΔP when using a filter 18 with high air permeability and a pump 35 with a pump flow rate X1 is value P211, which is smaller than value P111. In other words, in order to achieve the same pressure difference as the filter 18 with low air permeability, the pump flow rate of the filter 18 with high air permeability needs to be increased from X1 to X2.

[0089] Furthermore, as can be seen from the line P12, with toner present, the pressure difference ΔP is P121 when the pump flow rate is X1. Value P121 is greater than value P111. As can be seen from the line P22, with toner present, the pressure difference ΔP is P221 when the pump flow rate is X1. Value 221 is greater than value 211. Thus, it can be seen that, under the same conditions of air permeability of filter 18 and pump flow rate, the pressure difference ΔP is larger with toner present than without toner. This is because the toner T rests on the bottom surface 18e of filter 18, causing pressure loss as air passes through the toner T.

[0090] Furthermore, the gap in the pressure difference ΔP between the toner-containing and toner-free states in a filter with low air permeability is P121-P111. The gap in the pressure difference ΔP between the toner-containing and toner-free states in a filter with high air permeability is P221-P211. Since (P121-P111) is larger than (P221-P211), it can be seen that the lower the air permeability of the filter, the larger the gap in the pressure difference ΔP between the toner-containing and toner-free states. A larger gap in the pressure difference ΔP between the toner-containing and toner-free states is advantageous for the fluidization of toner T.

[0091] Here, as shown in Figure 11(d), the state in which toner T is present only on a portion of the bottom surface 18e of the filter 18, and a portion of the bottom surface 18e is exposed, is defined as the "partial toner present" state. In the partial toner present state, the amount of airflow is reduced in the areas of the filter 18 with low permeability where toner is present compared to the areas without toner. For this reason, it can be considered as the pressure difference ΔP at a flow rate slightly lower than the pump flow rate X1, and the pressure difference ΔP is value P122. Also, the amount of airflow is increased in the areas of the filter 18 with low permeability where toner is not present compared to the areas with toner. For this reason, it can be considered as the pressure difference ΔP at a flow rate slightly higher than the pump flow rate X1, and the pressure difference ΔP is value P112. Values ​​P112 and P122 are both higher than the value P111.

[0092] Similarly, when there is some toner present, the amount of airflow is reduced in the areas of the highly permeable filter 18 where toner is present compared to areas where toner is not. Therefore, this can be considered as the pressure difference ΔP at a flow rate slightly lower than the pump flow rate X1, and the pressure difference ΔP becomes value P222. Also, in the areas of the highly permeable filter 18 where toner is not present, the amount of airflow is increased compared to areas where toner is present. Therefore, this can be considered as the pressure difference ΔP at a flow rate slightly higher than the pump flow rate X1, and the pressure difference ΔP becomes value P212. Values ​​P212 and P222 are both higher than value P211.

[0093] The pressure difference ΔP between the air chamber 17 and the toner chamber 16 represents the pressure loss when air passes through the filter 18. As shown in Figure 13, increasing the pump flow rate increases the pressure loss due to the filter 18. As mentioned above, for the pump 35 to be able to transport toner to the developing container 12, the pump flow rate must be 10% or more of the airflow rate through the filter 18. On the other hand, supplying more air to the filter 18 than the airflow rate through the filter 18 will result in a greater pressure loss due to the filter 18. Therefore, from the standpoint of energy saving, it is desirable that the pump flow rate is 100% or less of the airflow rate through the filter 18.

[0094] [How to check toner fluidization conditions] Next, we will explain a method for verifying that air is blown out from the entire bottom surface 18e of the filter 18, regardless of whether or not toner is present on the bottom surface 18e of the filter 18. For example, if there is some toner present, but air is blown out only from the parts of the filter 18 where there is no toner, the toner in the toner chamber 16 will not be properly fluidized by the air.

[0095] As part of the verification method described above, the pressure in the air chamber 17 and the pressure in the toner chamber 16 are measured while the toner transport operation is in progress, and the pressure difference ΔP is calculated. The pressure difference ΔP is calculated under two conditions: when there is no toner and when there is some toner. When the pressure difference ΔP in the state with some toner is greater than the pressure difference ΔP in the state with no toner, it can be confirmed that air is being blown out from the entire bottom surface 18e of the filter 18. If the pressure difference ΔP in the state with some toner and the pressure difference ΔP in the state with no toner are the same, it can be considered that in the state with some toner, air is passing through only the parts of the filter 18 where there is no toner. Therefore, air is not being blown out from the parts of the filter 18 where there is toner, and the toner T cannot be properly fluidized.

[0096] Furthermore, the pressure in the air chamber 17 is higher when there is some toner present or when there is toner present compared to when there is no toner. This is because the toner on the bottom surface 18e of the filter 18 creates resistance when air passes through. Therefore, when the pressure in the air chamber 17 when there is some toner present is greater than the pressure in the air chamber 17 when there is no toner, it can be confirmed that air is able to blow out from the entire bottom surface 18e of the filter 18.

[0097] Furthermore, the angle of inclination of the inclined section 18c and the airflow rate supplied by the pump 35 also affect the toner T discharge performance. Increasing the angle of the inclined section 18c is effective in discharging toner T from the entire toner chamber 16. However, if the angle of the inclined section 18c is too large, the capacity of toner T that can be contained in the toner chamber 16 will decrease compared to a configuration with a smaller angle of the inclined section 18c. This may make it difficult to achieve miniaturization of the toner cartridge C when trying to contain the desired amount of toner T. Therefore, from the standpoint of securing capacity and miniaturizing the toner cartridge C, it is more desirable to set the angle of the inclined section 18c as small as possible while still being able to discharge toner T.

[0098] [Positioning of the discharge pipe] As shown in Figures 3(a) and 3(b), the first frame 32 can position the discharge pipe 27 such that its inlet 27a faces the lowest part 18b of the filter 18 by engaging the support portion 31b with the discharge pipe 27. Here, the position of the inlet 27a in the toner chamber 16 relative to the lowest part 18b of the filter 18 affects the discharge of toner T. As shown in Figures 11(a) to 11(c), the toner T contained in the toner chamber 16 is fluidized by the inflow of air and transported toward the lowest part 18b by the configuration of the inclined portion 18c. Therefore, in the configuration of this embodiment, it is most desirable from the viewpoint of toner T discharge to provide the inlet 27a in the vicinity of the lowest part 18b.

[0099] For example, if the discharge pipe 27 is made of a flexible member without a support part 31b inside the toner chamber 16, the position of the inlet 27a may change due to stimuli such as shocks and vibrations to the toner cartridge C or the movement of toner T. If the position of the inlet 27a shifts away from the vicinity of the lowest part 18b, the amount of toner T discharged may also change, since the position where the most toner T accumulates inside the toner chamber 16 is near the lowest part 18b.

[0100] In particular, as shown in Figure 11(c), when the amount of toner T in the toner chamber 16 decreases, if the position of the inlet 27a moves to a position where there is little or no toner T, it becomes difficult to send the toner T to the discharge pipe 27 even if air is introduced from the intake port 20. As a result, the amount of toner T remaining in the toner chamber 16 may increase compared to when the inlet 27a is positioned near the bottom 18b. In other words, by properly positioning the inlet 27a, toner T can be discharged stably from the toner cartridge C to the outside. Furthermore, the amount of toner T remaining in the toner chamber 16 can be controlled, and excess toner T can be prevented from remaining in the toner chamber 16 when toner T is not discharged from the discharge port 16a due to the inflow of air into the intake port 20.

[0101] As described above, in this embodiment, when the toner transport operation is performed, the pressures in each part are set to be in the relationship shown in Figure 10. That is, the pressure P1 of the pump 35, the pressure P2 of the air chamber 17, the pressure P3 of the toner chamber 16, and the pressure P4 of the toner storage section 12a are all above atmospheric pressure, and the pressure P3 of the toner chamber 16 is greater than the pressure P4 of the toner storage section 12a. As a result, the air supplied by the pump 35 can transport the toner T in the toner chamber 16 to the toner storage section 12a. Also, because the pressure P2 of the air chamber 17 is greater than the pressure P3 of the toner chamber 16, air can be supplied to the toner chamber 16 via the filter 18, and the toner T on the bottom surface 18e of the filter 18 can be fluidized. Note that these pressures P1 to P4 are just an example, and the values ​​of each pressure P1 to P4 can be set arbitrarily as long as the relative magnitudes of the pressures are as described above. These pressures P1 to P4 are determined by the pump flow rate of the pump 35, the airflow rate of the filter 18, the pressure loss in the air supply pipe 21, and the pressure loss in the passage 24, etc. The pressure loss in the air supply pipe 21 and passage 24 is determined by the inner diameter, cross-sectional area, length, and arrangement of the air supply pipe 21 and passage 24, etc.

[0102] Furthermore, the developing container 12 is provided with an opening 26, and the opening 26 is covered by a filter 26a which acts as a developing filter, so that at least a portion of the air that flows into the developing container 12 can be discharged to the outside of the developing container 12. In particular, the amount of air taken in from the pump 35 to the toner cartridge C is less than the sum of the amount of air taken in to the developing container 12 via the passage 24 and the amount of air that can be discharged to the outside of the developing container 12 through the opening 26 and the filter 26a. As a result, the rise in internal pressure of the developing container 12 is suppressed, and toner T can be smoothly transported from the toner cartridge C to the developing container 12 while suppressing toner leakage from the developing container 12.

[0103] In this embodiment, the air permeability of the filter 18 provided in the toner cartridge C is 1 / 15 or more and 1 / 5 or less of the air permeability of the filter 26a covering the opening 26 of the developing container 12. For example, the air permeability of the filter 18 is 0.9 [cm²]. 3 / (cm 2 ·s) and the air permeability of filter 26a is 11.0 [cm 3 / (cm 2 The air permeability of filter 26a is preferably large enough to prevent toner from leaking out of the developing container 12 through filter 26a, in order to reduce the internal pressure of the developing container 12. For example, if the air permeability of filter 26a is 11.0 [cm] 3 / (cm 2 If the value exceeds (s), there is a risk that toner may leak out of filter 26a.

[0104] On the other hand, a lower air permeability of the filter 18 is advantageous for the fluidization of toner in the toner chamber 16. This is because a lower air permeability of the filter 18 increases the pressure difference between the air chamber 17 and the toner chamber 16, increasing the airflow velocity through the filter 18 and enhancing the toner fluidization effect. However, if the air permeability of the filter 18 is too low, the pressure loss in the filter 18 will increase, requiring a higher pump flow rate for toner transport. Considering these factors, the air permeability of the filter 18 is preferably 1 / 15 or more and 1 / 5 or less of the air permeability of the filter 26a.

[0105] Furthermore, in this embodiment, when toner T is present on only a portion of the bottom surface 18e, the air permeability of the filter 18 and the pump flow rate are set so that air blows out (passes through) from the entire bottom surface 18e of the filter 18. More specifically, when the toner transport operation is being performed, the air permeability of the filter 18 is set so that the pressure difference ΔP between the toner chamber 16 and the air chamber 17 in the first state (partial toner present) is greater than the pressure difference ΔP in the second state (no toner). At this time, the pressure in the air chamber 17 in the partial toner present state is greater than the pressure in the air chamber 17 in the no toner state. Therefore, even in the partial toner present state, air can pass through the area on the bottom surface 18e of the filter 18 where the toner is present, and the toner T can be loosened and made fluid. Furthermore, this fluidization of the toner by air causes the toner on the inclined portion 18c of the filter 18 to collapse towards the bottom 18b, allowing the toner to be collected at the inlet 27a of the discharge pipe 27, thereby suppressing the amount of toner T remaining in the toner chamber 16.

[0106] Furthermore, in this embodiment, when the toner transport operation is being performed, the pump flow rate of the pump 35 is set to be 10% or more and 100% or less of the air permeability of the filter 18. By setting the pump flow rate to 10% or more of the air permeability of the filter 18, the toner can be reliably transported from the toner cartridge C to the developing container 12 by the air supplied from the pump 35. Also, by setting the pump flow rate to 100% or less of the air permeability of the filter 18, pressure loss due to the filter 18 can be suppressed, improving energy efficiency and allowing the pump 35 to be made smaller. The air permeability of the filter 18 can be determined by the air permeability of the filter 18 and the area of ​​the bottom surface 18e.

[0107] <Other Embodiments> In the above-described embodiment, the configuration of the toner cartridge C, which can be attached to and detached from the main body 100 of the device, was explained. However, the present invention is not limited to this. The present invention can also be applied to all-in-one cartridges that integrate the toner cartridge C and the process cartridge B, or to cartridges that integrate the toner cartridge C and the developing means, and the same effects as described above can be obtained.

[0108] Furthermore, although the above-described embodiment used a monochrome image forming apparatus as the image forming apparatus interface (IF), the invention is not limited to this. For example, it is also possible to use a color image forming apparatus as the image forming apparatus interface. In that case, similar effects can be obtained by adopting the configuration described in the present invention for the configuration of multiple toner cartridges or process cartridges that contain toners of different colors.

[0109] Furthermore, in the above-described embodiment, the discharge port 16a and discharge pipe 27 were provided in the toner chamber 16, but the invention is not limited to this. For example, the discharge port 16a may be provided in the air chamber 17, the discharge pipe 27 may pass through a hole provided in the filter 18, and the inlet 27a may face the lowest part 18b of the filter 18, while the outlet 27b may be connected to the discharge port 16a.

[0110] Summary of this disclosure This disclosure includes at least the following: (Composition 1) An image forming apparatus, A cartridge that contains toner, The device body, which allows the aforementioned cartridge to be attached and detached, The pump section that discharges air, A developing container including a toner storage section for storing toner, A tube for transporting the toner discharged from the cartridge along with air to the toner storage section of the developing container, The device comprises a main body having, The aforementioned cartridge is The toner chamber that houses the toner, A filter configured to obstruct the passage of toner while allowing the passage of air, An air chamber adjacent to the toner chamber via the aforementioned filter, the air chamber having an intake for taking in air discharged from the pump section, An outlet for discharging the toner contained in the toner chamber to the outside of the cartridge, It has a pipe configured to communicate with the aforementioned discharge port, through which the toner discharged from the discharge port passes, The filter has a partition that separates the toner chamber and the air chamber such that at least a portion of the toner chamber is located above the air chamber in the direction of gravity. During the toner transport operation in which toner from the toner chamber is discharged from the outlet and transported to the toner storage section via the tube by air discharged from the pump section and taken in from the intake of the cartridge, the pressure of the pump section, the pressure of the air chamber, the pressure of the toner chamber, and the pressure of the toner storage section are all greater than or equal to atmospheric pressure, the pressure of the toner chamber is greater than the pressure of the toner storage section, and the pressure of the air chamber is greater than the pressure of the toner chamber. When the toner transport operation is being performed, the pressure difference between the toner chamber and the air chamber in the first state, where toner is present only on a portion of the partition portion of the filter, is greater than the pressure difference between the toner chamber and the air chamber in the second state, where no toner is present on the entire partition portion of the filter. An image forming apparatus characterized by the following: (Configuration 2) When the toner transport operation is being performed, the pressure in the air chamber in the first state is greater than the pressure in the air chamber in the second state. The image forming apparatus according to configuration 1, characterized in that it is a picture forming apparatus. (Composition 3) During the toner transport operation, the pump flow rate of the pump unit is 10% or more and 100% or less of the airflow rate of the filter. An image forming apparatus according to configuration 1 or 2, characterized by the above. (Composition 4) The aforementioned filter is the first filter, The developing container is provided with an opening that allows the inside of the toner storage section to communicate with the outside of the developing container. The developing container has a second filter configured to cover the opening and prevent the passage of toner while allowing the passage of air. An image forming apparatus according to any one of configurations 1 to 3, characterized by the above. (Composition 5) The air permeability of the first filter is less than that of the second filter. The image forming apparatus according to configuration 4, characterized in that... (Composition 6) The pump section includes a diaphragm pump. An image forming apparatus according to any one of configurations 1 to 5, characterized by the above. (Composition 7) A first container that forms the toner chamber together with the filter, A second container, together with the filter, forms the air chamber, The first container and the second container are joined together with the outer edge of the filter sandwiched between them. An image forming apparatus according to any one of configurations 1 to 6 characterized by the above. (Composition 8) The aforementioned discharge port and pipe are provided in the toner chamber. The end of the pipe connected to the outlet and the end opposite to it are configured to open toward the filter. An image forming apparatus according to any one of configurations 1 to 7, characterized by the above. (Composition 9) An image forming apparatus, A cartridge that contains toner, The device body, which allows the aforementioned cartridge to be attached and detached, The pump section that discharges air, A developing container including a toner storage section for storing toner, A tube for transporting the toner discharged from the cartridge along with air to the toner storage section of the developing container, The device comprises a main body having, The aforementioned cartridge is The toner chamber that houses the toner, A first filter configured to obstruct the passage of toner while allowing the passage of air, An air chamber adjacent to the toner chamber via the first filter, the air chamber having an intake for taking in air discharged from the pump unit, An outlet for discharging the toner contained in the toner chamber to the outside of the cartridge, It has a pipe configured to communicate with the aforementioned discharge port, through which the toner discharged from the discharge port passes, The air discharged from the pump unit, which is taken in through the intake port of the cartridge, causes the toner in the toner chamber to be discharged from the outlet and transported to the toner storage unit via the tube. The developing container is provided with an opening to connect the toner storage section with the outside of the developing container. The developing container has a second filter configured to cover the opening and prevent the passage of toner while allowing the passage of air. The air permeability of the first filter is less than that of the second filter. An image forming apparatus characterized by the following: (Composition 10) The air permeability of the first filter is 1 / 15 or more and 1 / 5 or less of the air permeability of the second filter. The image forming apparatus according to configuration 9, characterized by the features described therein. (Composition 11) When the toner contained in the toner chamber is being transported to the toner storage section by the air discharged from the pump section, the pump flow rate of the pump section is 10% or more and 100% or less of the airflow rate of the first filter. The image forming apparatus according to configuration 9 or 10, characterized by the above. (Composition 12) The pump section includes a diaphragm pump. An image forming apparatus according to any one of configurations 9 to 11, characterized by the features described herein. (Composition 13) A first container that forms the toner chamber together with the first filter, The system comprises a second container that forms the air chamber together with the first filter, The first container and the second container are joined together with the outer edge of the first filter sandwiched between them. An image forming apparatus according to any one of configurations 9 to 12, characterized by the features described herein. (Composition 14) The aforementioned discharge port and pipe are provided in the toner chamber. The end of the pipe connected to the outlet and the end opposite to it are configured to open toward the first filter. An image forming apparatus according to any one of configurations 9 to 13, characterized by the features described herein. [Explanation of Symbols]

[0111] 12: Developing container / 12a: Toner storage section / 16: Toner chamber / 16a: Outlet / 17: Air chamber / 18: Filter, first filter / 18a: Outer edge / 18e: Partition (bottom) / 20: Inlet / 24: Tube (passage) / 26: Opening / 26a: Second filter (filter) / 27: Pipe (discharge pipe) / 27a: Inlet / 27b: Outlet / 31: Second container (second frame) / 32: First container (first frame) / 35: Pump section (pump) / 100: Main unit / C: Cartridge (toner cartridge) / G: Direction of gravity / IF: Image forming apparatus / P1, P2, P3, P4: Pressure / Y: Longitudinal direction (direction) / ΔP: Pressure difference

Claims

1. An image forming apparatus, A cartridge that contains toner, The device body, which allows the aforementioned cartridge to be attached and detached, The pump section that discharges air, A developing container including a toner storage section for storing toner, A tube for transporting the toner discharged from the cartridge along with air to the toner storage section of the developing container, The device comprises a main body having, The aforementioned cartridge is The toner chamber that houses the toner, A filter configured to obstruct the passage of toner while allowing the passage of air, An air chamber adjacent to the toner chamber via the aforementioned filter, the air chamber having an intake for taking in air discharged from the pump section, An outlet for discharging the toner contained in the toner chamber to the outside of the cartridge, It has a pipe configured to communicate with the aforementioned discharge port, through which the toner discharged from the discharge port passes, The filter has a partition that separates the toner chamber and the air chamber such that at least a portion of the toner chamber is located above the air chamber in the direction of gravity. During the toner transport operation in which toner from the toner chamber is discharged from the outlet and transported to the toner storage section via the tube by air discharged from the pump section and taken in from the intake of the cartridge, the pressure of the pump section, the pressure of the air chamber, the pressure of the toner chamber, and the pressure of the toner storage section are all greater than or equal to atmospheric pressure, the pressure of the toner chamber is greater than the pressure of the toner storage section, and the pressure of the air chamber is greater than the pressure of the toner chamber. When the toner transport operation is being performed, the pressure difference between the toner chamber and the air chamber in the first state, where toner is present only on a portion of the partition portion of the filter, is greater than the pressure difference between the toner chamber and the air chamber in the second state, where no toner is present on the entire partition portion of the filter. An image forming apparatus characterized by the following features.

2. When the toner transport operation is being performed, the pressure in the air chamber in the first state is greater than the pressure in the air chamber in the second state. The image forming apparatus according to feature 1.

3. During the toner transport operation, the pump flow rate of the pump unit is 10% or more and 100% or less of the airflow rate of the filter. The image forming apparatus according to feature 1.

4. The aforementioned filter is the first filter, The developing container is provided with an opening that allows the inside of the toner storage section to communicate with the outside of the developing container. The developing container has a second filter configured to cover the opening and prevent the passage of toner while allowing the passage of air. The image forming apparatus according to any one of claims 1 to 3.

5. The air permeability of the first filter is less than that of the second filter. The image forming apparatus according to feature 4.

6. The pump section includes a diaphragm pump. The image forming apparatus according to any one of claims 1 to 3.

7. A first container that forms the toner chamber together with the filter, The system comprises a second container that forms the air chamber together with the filter, The first container and the second container are joined to each other with the outer edge of the filter sandwiched between them. The image forming apparatus according to any one of claims 1 to 3.

8. The aforementioned discharge port and pipe are provided in the toner chamber. The end of the pipe connected to the outlet and the end opposite to it are configured to open toward the filter. The image forming apparatus according to any one of claims 1 to 3.

9. An image forming apparatus, A cartridge that contains toner, The device body, which allows the aforementioned cartridge to be attached and detached, The pump section that discharges air, A developing container including a toner storage section for storing toner, A tube for transporting the toner discharged from the cartridge along with air to the toner storage section of the developing container, The device comprises a main body having, The aforementioned cartridge is The toner chamber that houses the toner, A first filter configured to obstruct the passage of toner while allowing the passage of air, An air chamber adjacent to the toner chamber via the first filter, the air chamber having an intake for taking in air discharged from the pump unit, An outlet for discharging the toner contained in the toner chamber to the outside of the cartridge, It has a pipe configured to communicate with the aforementioned discharge port, through which the toner discharged from the discharge port passes, The air discharged from the pump unit, which is taken in through the intake port of the cartridge, causes the toner in the toner chamber to be discharged from the outlet and transported to the toner storage unit via the tube. The developing container is provided with an opening to connect the toner storage section with the outside of the developing container. The developing container has a second filter configured to cover the opening and prevent the passage of toner while allowing the passage of air. The air permeability of the first filter is less than that of the second filter. An image forming apparatus characterized by the following features.

10. The air permeability of the first filter is 1 / 15 or more and 1 / 5 or less of the air permeability of the second filter. The image forming apparatus according to feature 9.

11. When the toner contained in the toner chamber is being transported to the toner storage section by the air discharged from the pump section, the pump flow rate of the pump section is 10% or more and 100% or less of the airflow rate of the first filter. The image forming apparatus according to feature 9.

12. The pump section includes a diaphragm pump. The image forming apparatus according to any one of claims 9 to 11.

13. A first container that forms the toner chamber together with the first filter, The system comprises a second container that forms the air chamber together with the first filter, The first container and the second container are joined together with the outer edge of the first filter sandwiched between them. The image forming apparatus according to any one of claims 9 to 11.

14. The aforementioned discharge port and pipe are provided in the toner chamber. The end of the pipe connected to the outlet and the end opposite to it are configured to open toward the first filter. The image forming apparatus according to any one of claims 9 to 11.

Images