Image forming apparatus and method for filling with developer

Abstract

This technology provides a way to stabilize the amount of developer transported from the developer container to the developing unit. [Solution] An image forming apparatus comprising: a main body having a developing unit having a developing roller that supplies developer received from an inlet to a photosensitive drum; a developer container that houses the developer and has an outlet and is detachable from the main body; and a developer transport path that connects the outlet and the inlet, wherein the main body has an intake and exhaust unit that can perform an exhaust operation to supply air to the developer container and an intake operation to draw air from the developer container, the intake and exhaust unit, by exhaust operation, forms a first flow of air that flows from the developer container to the developing unit via the developer transport path, thereby supplying the developer from the developer container to the developing unit, and by intake operation, forms a second flow of air that flows from the developing unit to the developer container via the developer transport path.

Description

Technical Field

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

Background Art

[0002] In an electrophotographic image forming apparatus, a toner storage unit (developer container) that stores toner (developer) used for image formation is configured to be detachable from the apparatus main body separately from a developing unit for performing an electrophotographic process. In the toner conveyance from the toner storage unit to the developing unit, for example, as in Patent Document 1, there is a configuration in which toner is conveyed by two types of pumps: an exhaust pump for exhausting air and a suction pump for sucking toner and air. In the toner storage unit according to Patent Document 1, the toner fluidized by the air flowing into the toner storage portion of the toner storage unit from the exhaust pump is collected at the lower portion of the toner storage portion using an inclined surface provided on the bottom surface of the toner storage portion and then conveyed. Then, the toner collected at the lower portion of the toner storage portion and fluidized by mixing with air is sucked by the suction pump and conveyed to the developing unit of the image forming apparatus.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] Here, since the developing unit has rotating parts such as developer supply rollers, if toner remains inside, it will deteriorate due to friction. Deteriorated toner negatively affects image formation. To avoid this, it is effective to keep the amount of toner in the developing unit constant. For this reason, it is desirable that the amount of toner transported to the developing unit be stable. However, when toner is transported by airflow as described above, toner that does not reach the developing unit may accumulate in the toner transport path. The amount of toner that accumulates can vary due to various factors. If the next toner transport is carried out in this state, the variation in the amount of accumulated toner will be added together, making the toner transport amount unstable.

[0005] The objective of the present invention is to provide a technology for stabilizing the amount of developer transported from the developer container to the developing unit. [Means for solving the problem]

[0006] To solve the above-mentioned problems, the image forming apparatus of the present invention is: An image forming apparatus for forming an image on a recording material, A device body comprising: a photosensitive drum; a developing unit having a developer receiving port, and a developing roller that supplies the developer received from the receiving port to the photosensitive drum; A developer container that contains the developer and has an outlet, and is detachable from the main body of the apparatus, A developer transport path connecting the discharge port and the receiving port, In an image forming apparatus comprising, The apparatus body is characterized by having an intake and exhaust unit capable of performing an exhaust operation in which air is supplied to the developer container to form an airflow that flows from the developer container to the developing unit via the developer transport path, thereby supplying the developer from the developer container to the developing unit, and an intake operation in which air is sucked from the developer container to form an airflow that flows from the developing unit to the developer container via the developer transport path. To solve the above-mentioned problems, the developer filling method of the present invention is: A method for filling a developer container, which is detachable from the main body of an image forming apparatus, The aforementioned developer container is A developer storage chamber containing the developer and equipped with a developer discharge port, A filter that allows air to pass through but prevents the developer from passing through, An air chamber is separated from the developer storage chamber by the filter and is provided with an air inlet for receiving air supplied from the intake and exhaust section of the main body of the apparatus, It has, The air chamber is configured to be mounted on the main body of the device in a position where it is located below the developer storage chamber. When filling the developer into the developer storage chamber, the air chamber is positioned above the developer storage chamber, the discharge port is used as the developer filling port, and the developer is filled into the developer storage chamber from the discharge port while drawing air from the air inlet. [Effects of the Invention]

[0007] According to the present invention, it is possible to stabilize the amount of developer transported from the developer container to the developing unit. [Brief explanation of the drawing]

[0008] [Figure 1] Cross-sectional view of the image forming apparatus according to Example 1 [Figure 2] Cross-sectional view of the developing unit according to Example 1 [Figure 3] Cross-sectional view of the toner storage unit according to Example 1 [Figure 4] Cross-sectional view of the toner storage unit and developing unit according to Example 1 [Figure 5] Cross-sectional view of the toner storage unit and developing unit according to Example 1 [Figure 6] Cross-sectional view of the toner storage unit and developing unit according to Example 2 [Figure 7] Cross-sectional view of the toner storage unit and developing unit according to Example 2 [Figure 8] Cross-sectional view of the toner storage unit according to the modification of Example 2

Mode for Carrying Out the Invention

[0009] Hereinafter, with reference to the drawings, embodiments for carrying out this invention will be exemplarily described in detail based on examples. However, dimensions, materials, shapes, relative arrangements, etc. of the components described in this embodiment should be appropriately changed according to the configuration of the apparatus 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. Also, although a plurality of features are described in the embodiment, not all of these plurality of features are essential to the invention, and the plurality of features may be arbitrarily combined. Furthermore, in the accompanying drawings, the same or similar configurations are given the same reference numerals, and duplicate explanations are omitted.

[0010] Examples of the image forming apparatus in the following description include a copying machine, a printer, a multifunction machine, a commercial printing apparatus, etc. An image is formed on a recording medium (recording material) based on image information input from an external computer or image information read from a document. As the recording medium, sheets of various materials and shapes such as paper such as plain paper and cardboard, plastic film, coated paper, sheets of special shapes such as envelopes and index paper, and cloth are used.

[0011] (Example 1) FIG. 1 is a schematic view showing a cross-sectional configuration of an image forming apparatus IF according to a first embodiment of the present invention, and FIG. 2 is a view of a developing unit B. As shown in FIG. 1, the developing unit B and the toner storage unit C are installed in the apparatus main body A of the image forming apparatus IF and form an image on a sheet P which is a recording medium. The apparatus main body A is the part excluding the developing unit B and the toner storage unit C from the image forming apparatus IF.

[0012] <Configuration of the entire image forming apparatus> As shown in FIG. 1, the image forming apparatus IF of this embodiment is an electrophotographic laser beam printer. In addition to the installation portions for the developing unit B and the toner storage unit C, the apparatus main body A has a pickup roller 5a, a pair of conveyance rollers 5b, a transfer roller 7, a fixing device 9, a pair of discharge rollers 5c, and a discharge tray 10 along the direction in which the sheet P is conveyed from the sheet tray 4. A control unit 100 for controlling the operations of each component of the image forming apparatus IF is provided in the apparatus main body A. The control unit 100 controls the operations of each part constituting the air intake and exhaust means 135 in the exhaust operation and the intake operation of the air intake and exhaust means 135, which will be described later.

[0013] The developing unit B includes a photosensitive drum 1 as a photoreceptor, a developing roller 2 as a developer carrier, a charging roller 11 as a charging means, a toner chamber 12 as a developer storage unit for storing the toner T supplied to the developing roller 2, and the like. The toner storage unit C as a toner container stores the toner T to be replenished to the toner chamber 12 of the developing unit B.

[0014] <Image Forming Process> When the image forming apparatus IF receives a signal to start image formation on the sheet P, the photosensitive drum 1 is rotationally driven in the direction of arrow R in FIG. 1. The charging roller 11 contacts the outer peripheral surface of the photosensitive drum 1 and uniformly charges the surface of the photosensitive drum 1. The laser scanner 3 irradiates the photosensitive drum 1 with a laser beam L based on the image information and performs an exposure operation of writing an electrostatic latent image on the surface of the photosensitive drum 1.

[0015] The toner T stored in the toner chamber 12 is sent out toward the sponge-like developer supply roller 6 by the stirring member 13. Then, the toner T is supplied to the developing roller 2 by the developer supply roller 6 and is carried in a thin layer on the surface of the developing roller 2 by the developing blade 15 (see FIG. 2). The toner T that reaches the developing area where the developing roller 2 and the photosensitive drum 1 face each other transfers from the developing roller 2 to the surface of the photosensitive drum 1 according to the potential distribution on the surface of the photosensitive drum 1. Thereby, the electrostatic latent image on the surface of the photosensitive drum 1 is visualized as a toner image.

[0016] In parallel with this process, the sheet P is fed at a timing synchronized with the exposure operation of the laser scanner 3. The pickup roller 5a shown in Figure 1 feeds the sheet P loaded on the sheet tray 4 out of the sheet tray 4. The transport roller pair 5b receives the sheet P from the pickup roller 5a and transports the sheet P to the transfer section between the photosensitive drum 1 and the transfer roller 7. Then, when a bias voltage is applied to the transfer roller 7, the toner image supported on the photosensitive drum 1 is transferred to the sheet P.

[0017] The sheet P onto which the toner image has been transferred is transported along the transport guide 8 to the fuser unit 9. The fuser unit 9 applies heat and pressure to the toner image on the sheet P using the heating roller 9a and the pressure roller 9b, fixing the image to the sheet P. After the image fixing process, the sheet P is discharged by the discharge roller pair 5c into the discharge tray 10 located at the top of the main body A of the device.

[0018] <Developing Unit> Next, the configuration overview of the developing unit B will be explained using Figure 2. In addition to the photosensitive drum 1, charging roller 11, developing roller 2, developing blade 15, developer supply roller 6, toner chamber 12, etc., the developing unit B of this embodiment is provided with a receiving port 24 for receiving toner T supplied from the toner storage unit C.

[0019] <Explanation of each part of the toner storage unit> After outlining the overall configuration of the toner storage unit, each part will be explained. Figure 3 is a cross-sectional view of the toner storage unit. Figure 4 is a cross-sectional view of the toner storage unit and the developing unit. be.

[0020] First, let's describe the overall configuration of the toner storage unit C. As shown in Figure 3, the toner storage unit C consists of a first frame 31 and a second frame 32. The first ventilation member, the first filter 18, is positioned between the first frame 31 and the second frame 32, and the flanges of the first frame 31a, the second frame 32a, and the filter flange 18a are joined together.

[0021] Due to this configuration, the toner storage unit C is divided (partitioned) into a toner storage section 16 (developer storage chamber) and an air chamber 17 by a first filter 18. The toner storage section 16 is provided with a first transport path 27, and the air chamber 17 is provided with an air inlet 20 (air receiving port). The air chamber 17 is located below the toner storage section 16.

[0022] The toner storage section 16 will now be described. As shown in Figure 3, the toner storage section 16 is a space enclosed by a second frame 32 and a first filter 18 at its bottom, and it stores toner T. The second frame 32 has a first inlet support section 32b, which supports the vicinity of the first inlet 27a of the first transport path 27. The second frame 32 also has a second inlet support section 32c, which supports the second inlet 27b (discharge port) of the first transport path 27. The first inlet support section 32b may be integrated with the second frame 32 that constitutes the toner storage section 16, or the first inlet support section 32b may be a separate component fixed to the second frame 32.

[0023] Let's describe the air chamber 17. As shown in Figure 3, the air chamber 17 is a space enclosed by the first frame 31 and the first filter 18, with the first filter 18 as the ceiling, and is a single, connected space. As shown in Figure 1, when the toner storage unit C is installed in the main body A of the device, the air port 20 is connected to the air intake and exhaust means 35, and air flows in and out from the air port 20.

[0024] The first filter 18 will now be described. The first filter 18 is a porous material made of, for example, resin fibers, with a pore size and density that allows air to pass through but prevents toner T from passing through. Alternatively, the first filter 18 can be made from a filter material formed by, for example, a heat press.

[0025] The first transport path 27 will now be described. As shown in Figure 4, the first transport path 27 is a path formed by a cylindrical tube (first tube) with an internally connected structure. One end of the first transport path 27 is a first inlet 27a provided inside the toner storage section 16, and the other end of the first transport path 27 is a second inlet 27b leading to the outside of the toner storage unit C. The first transport path 27 can be made of a flexible tube made of rubber or silicone, or a hollow member such as a pipe made of resin or metal, as appropriate. The first inlet 27a, which opens into the inside of the toner storage section 16 in the first transport path 27, opens so as to face the first filter 18, and the first filter 18 has a concave shape in which the area facing the first inlet 27a is most recessed downwards.

[0026] The second transport path 28 will now be described. As shown in Figure 4, the second transport path 28 is a path formed by a cylindrical tube (second tube) with an internal connection between the toner storage unit C and the developing unit B when the toner storage unit C and the developing unit B are mounted on the main body A of the device. One end of the second transport path 28 is connected to the second outlet 27b (discharge port) of the toner storage unit C, and the other end of the second transport path 28 is connected to the receiving port 24 of the developing unit B. Similar to the first transport path 27, the second transport path 28 can be made of a flexible tube made of rubber or silicone, or a hollow member such as a pipe made of resin or metal, as appropriate.

[0027] The second filter 26 (second filter) will now be described. As shown in Figure 4, the second filter 26, as the second ventilation member, is installed above the toner chamber 12 of the developing unit B. It is a component. The second filter 26, like the first filter 18, is a porous component made of, for example, resin fibers, with a pore size and density that allows air to pass through but prevents toner T from passing through. In this embodiment, the second filter 26 is shown installed in the developing unit B, but it may also be installed in the portion of the second transport path 28 near the developing unit B.

[0028] As described above, the air exhausted by the air intake and exhaust means 35 shown in Figure 4 can only pass through a single path: from the air port 20, through the first filter 18, through the first transport path 27 and the second transport path 28, and then discharged to the outside of the developing unit B from the second filter 26. Due to this configuration, toner replenishment and accumulated toner recovery, as described later, are possible.

[0029] Furthermore, the toner storage unit C and the developing unit B in this embodiment may be configured to be detachable from the main body A of the device.

[0030] <How toner is supplied> Using Figure 4, the mechanism by which toner T is discharged from the toner storage unit C and replenished to the developing unit B will be explained. In this embodiment, the main body A of the device is equipped with an air intake and exhaust means 35 as an intake and exhaust section. The air intake and exhaust means 35 is capable of performing an exhaust operation to supply air to the toner storage unit C in order to form an airflow for supplying toner from the toner storage unit C to the developing unit B via the first transport path 27 and the second transport path 28 as developer transport paths.

[0031] In this embodiment, the air exhausted by the air intake and exhaust means 35 provided in the main body A of the device forms an airflow (first flow) from the air inlet 20 to the outside through the second filter 26. This airflow transports the toner T from the toner storage section 16 to the outside of the toner storage unit C and replenishes it to the developing unit B.

[0032] The details are explained below. As shown in Figure 4, the air intake and exhaust means 35 of the main body A of this embodiment is connected to the air port 20 of the air chamber 17 via the air pipe 21. The air exhausted by the air intake and exhaust means 35 is sent to the air chamber 17 through the air port 20 of the toner storage unit C, as described above. The air that has flowed into every corner of the air chamber 17 flows to the first filter 18 which forms the ceiling surface. Next, the air passes through the first filter 18 and flows into the toner storage section 16. The air that flows into the toner storage section 16 fluidizes the toner T inside the toner storage section 16. The air mixed with the toner T then passes through the first inlet / outlet 27a, the first transport path 27, the second inlet / outlet 27b, and the second transport path 28 in that order, and flows out from the second filter 26. Toner T that cannot pass through the second filter 26 remains in the toner chamber 12 of the developing unit B. In other words, the toner T from the toner storage unit C can be supplied to the developing unit B by the airflow exhausted from the air intake / exhaust means 35. At this time, toner that has flowed out from the toner storage section 16 but has not reached the toner chamber 12 accumulates in the first transport path 27 and the second transport path 28. (Hereinafter referred to as "accumulated toner")

[0033] <Mechanism for collecting accumulated toner> Using Figure 5, the mechanism for recovering the accumulated toner in the first transport path 27 and the second transport path 28 into the toner storage unit 16 after replenishment will be explained. The air intake and exhaust means 35 is capable of performing an intake operation to draw air from the toner storage unit C in order to form an airflow that flows from the developing unit B through the first transport path 27 and the second transport path 28 to the toner storage unit C.

[0034] The air intake and exhaust means 35 of this embodiment consists of a flexible container portion whose volume can be changed and an air port connection portion (intake and exhaust port) that connects the inner space (inside) and the outside. That is, the air intake and exhaust means 35 works by reducing the volume of the flexible container portion due to pressing or the like, allowing air to enter through the air port connection portion. This system performs exhaust and draws in air from the air port connection as the volume of the flexible container increases due to pulling or other means. For example, it is a bellows pump as shown in Figure 5. In this embodiment, when the variable volume of the air intake / exhaust means 35 is Vp, the volume of the first transport path 27 is V1, and the volume of the second transport path 28 is V2, it is set such that Vp > V1 + V2.

[0035] As shown in Figure 5(a), when the air intake and exhaust means 35 changes volume by Vp in the direction of arrow D1, which is the direction of pump volume reduction, the exhausted air generates an airflow F1 (first flow) during toner replenishment, and as described above, toner T can be supplied to the toner chamber 12.

[0036] Then, as shown in Figure 5(b), when the air intake / exhaust means 35 changes volume by Vp in the direction of arrow D2, which is the direction of pump volume increase, outside air is drawn in from the second filter 26. Since the amount of air drawn in corresponds to Vp, it mixes with the toner accumulated in the second transport path 28 and the first transport path 27, and an airflow F2 (second flow) for retrieving accumulated toner is generated, which passes through the first outlet 27a to the toner storage section 16. As a result, with this configuration, at least a portion of the toner accumulated in the first transport path 27 and the second transport path 28 can be recovered into the toner storage section 16. The air then passes through the first filter 18 and reaches the air intake / exhaust means 35.

[0037] As explained above, by reversing the flow of air during toner transport, the toner accumulated in the transport path is loosened, and at least a portion of the accumulated toner can be recovered into the toner storage section 16, thereby reducing the amount of accumulated toner. When the next toner replenishment is performed in this state, mainly only the toner transported from the toner storage section 16 is transported to the toner chamber 12, so variations in the replenishment amount can be reduced and the amount of toner transported can be stabilized.

[0038] (Example 2) Embodiment 2 of the present invention will be described with reference to FIGS. 6(a) to 7(b). Here, mainly the differences from Embodiment 1 in Embodiment 2 will be described, and the components common to Embodiment 1 will be denoted by the same reference numerals and the description thereof will be omitted again. Matters not particularly described here in Embodiment 2 are the same as those in Embodiment 1.

[0039] The configuration of this embodiment is different from that of Embodiment 1. When the variable volume of the air intake and exhaust means 135 is Vp, the volume of the first conveyance path 27 is V1, and the volume of the second conveyance path 28 is V2, it is set that Vp < V1 + V2. Even in this configuration, toner replenishment and recovery of the deposited toner are possible.

[0040] <Configuration of the air intake and exhaust means> As shown in FIG. 6(a), the air intake and exhaust means 135 of this embodiment has a volume change part (variable volume part) 135a, an intake path 135b connected to the volume change part 135a, and an exhaust path 135c. Further, an intake path valve 135d that is in an open state when the volume of the volume change part 135a increases is provided in the intake path 135b, and an exhaust path valve 135e that is in an open state when the volume of the volume change part 135a decreases is provided in the exhaust path 135c. The volume change part 135a can continuously change in a minute volume increase or decrease, and thereby intake and exhaust can be repeated, and for example, a diaphragm pump can be cited.

[0041] An intake switching part 36 is provided between the intake path 135b and the air port 20. The intake switching part 36 has a connection port with the intake path 135b, a connection port with an air pipe 21 connected to the air port 20, and a communication port with the outside air. Further, an air port side intake valve 36a that can be arbitrarily opened and closed is provided at the connection port with the air pipe 21, and an outside air side intake valve 36b that can be arbitrarily opened and closed is provided at the communication port with the outside air.

[0042] An exhaust switching part 37 is provided between the exhaust path 135c and the air port 20. Exhaust switching Section 37 has a connection port to the exhaust path 135c, a connection port to the air pipe 21 leading to the air port 20, and a communication port to the outside air. In addition, the connection port to the air pipe 21 is provided with an air port-side exhaust valve 37a that can be opened and closed at will, and the communication port to the outside air is provided with an outside air-side exhaust valve 37b that can be opened and closed at will.

[0043] <Airflow during toner replenishment> The airflow during toner replenishment will be explained using Figures 6(a) and 6(b). Figure 6(a) shows the state in which a flow path (first intake path) is formed for the air intake / exhaust means 135 to take in air from the outside to form the exhaust flow during the exhaust operation for supplying toner from the toner storage unit C to the developing unit B. Figure 6(b) shows the state in which a flow path (first exhaust path) is formed for the air intake / exhaust means 135 to discharge the air taken in from the outside towards the toner storage unit C via the first transport path 27 and the second transport path 28 during the exhaust operation described above.

[0044] When replenishing toner, the control unit 100 controls the intake valve 36a on the air inlet side of the intake switching unit 36 ​​to the "closed" state and the intake valve 36b on the outside air side to the "open" state, while the exhaust valve 37a on the air inlet side of the exhaust switching unit 37 to the "open" state and the exhaust valve 37b on the outside air side to the "closed" state.

[0045] As shown in Figure 6(a), the air intake and exhaust means 135 has a first path that connects the volume changing section 135a and the toner storage section 16, and includes an intake path 135b, an intake switching section 36, and an air pipe 21. The first path is configured to be able to communicate with the outside midway through the path by an intake opening 36c (first opening) which is opened and closed by an outside air side intake valve 36b (first outside air valve) in the intake switching section 36. In this first path, when the air inlet side intake valve 36a (first path valve) closes the first path on the side closer to the toner storage section 16 than the intake opening 36c, the outside air side intake valve 36b (first outside air valve) opens the intake opening 36c (first opening), and the volume changing section 135a increases its volume, the intake path valve 135d (first intake valve) opens and the exhaust path valve 135e (first exhaust valve) closes. As a result, as shown in Figure 6(a), the volume-changing section 135a communicates with the outside through the intake opening 36c, forming a first intake path between the intake opening 36c and the volume-changing section 135a, and creating an airflow in the direction indicated by arrow F31. In other words, a first intake path is formed in the first path.

[0046] Furthermore, as shown in Figure 6(b), the air intake and exhaust means 135 has a second path that connects the volume change section 135a and the toner storage section 16, and is different from the first path described above, and includes an exhaust path 135c, an exhaust switching section 37, and an air pipe 21. The second path is configured to be able to communicate with the outside midway through the path by an exhaust opening 37c (second opening) which is opened and closed by an outside air side exhaust valve 37b (second outside air valve) in the exhaust switching section 37. In this second path, when the air inlet side exhaust valve 37a (second path valve) opens the second path on the side closer to the toner storage section 16 than the exhaust opening 37c, the outside air side exhaust valve 37b closes the exhaust opening 37c, and the volume change section 135a decreases in volume, the exhaust path valve 135e (second path valve) opens and the intake path valve 135d (first path valve) closes. As a result, as shown in Figure 6(b), the volume change section 135a is in communication with the toner storage section 16, and the path (first exhaust path) formed between the volume change section 135a and the toner storage section 16 creates an airflow in the direction indicated by arrow F32. In other words, the first exhaust path is formed in the second path.

[0047] In this state, when the volume change section 135a of the air intake / exhaust means 135 continuously increases and decreases its volume, an airflow in the direction indicated by arrow F31 in Figure 6(a) and an airflow in the direction indicated by arrow F32 in Figure 6(b) alternately occur. Air taken in from the intake switching section 36 passes through the air intake / exhaust means 135 and the exhaust switching section 37 and flows into the air chamber 17. Then, the air that passes through the first filter 18 and flows into the toner storage section 16 passes through the first transport path 27 and the second transport path 28 and flows out from the second filter 26. As a result, as described above, Toner T can be supplied to the toner chamber 12 of image unit B, and any toner that does not reach the toner chamber 12 is deposited in the first transport path 27 and the second transport path 28.

[0048] <Airflow during toner collection> The airflow during toner retrieval will be explained using Figures 7(a) and 7(b). Figure 7(a) shows the state in which a flow path (second intake path) is formed for drawing air from the toner storage unit 16 to the air intake / exhaust means 135 during the intake operation for drawing air from the toner storage unit C and the developing unit B. Figure 6(7) shows the state in which a flow path (second exhaust path) is formed for the air intake / exhaust means 135 to discharge the air drawn in from the toner storage unit 16 during the above intake operation.

[0049] When retrieving accumulated toner, the control unit 100 controls the intake valve 36a on the air port side of the intake switching unit 36 ​​to the "open" state and the intake valve 36b on the outside air side to the "closed" state, while the exhaust valve 37a on the air port side of the exhaust switching unit 37 to the "closed" state and the exhaust valve 37b on the outside air side to the "open" state.

[0050] As shown in Figure 7(a), the air intake and exhaust means 135 has a first path including an air pipe 21, an intake switching section 36, and an intake path 135b. In the first path, when the air inlet side intake valve 36a (first path valve) opens the first path, the outside air side intake valve 36b (first outside air valve) closes the intake opening 36c (first opening), and the volume of the volume change section 135a increases, the intake path valve 135d (second intake valve) opens and the exhaust path valve 135e (second exhaust valve) closes. As a result, as shown in Figure 7(a), the volume change section 135a comes into communication with the toner storage section 16, and an airflow in the direction indicated by arrow F41 is formed by the path (second intake path) formed between the volume change section 135a and the toner storage section 16. In other words, a second intake path is formed in the first path.

[0051] Furthermore, as shown in Figure 7(b), the air intake and exhaust means 135 has a second path including an exhaust path 135c, an exhaust switching section 37, and an air pipe 21. In the second path, when the air inlet side exhaust valve 37a closes the second path, the outside air side exhaust valve 37b opens the exhaust opening 37c (second opening), and the volume of the volume change section 135a decreases, the exhaust path valve 135e (second exhaust valve) opens and the intake path valve 135d (second intake valve) closes. As a result, as shown in Figure 7(b), the volume change section 135a communicates with the outside through the exhaust opening 37c, and an airflow in the direction indicated by arrow F42 is formed by the path (second exhaust path) formed between the volume change section 135a and the exhaust opening 37c. In other words, a second exhaust path is formed in the second path.

[0052] In this state, when the volume changing section 135a of the air intake / exhaust means 135 continuously increases or decreases its volume, an airflow is generated in the direction indicated by arrow F4 in the figure. The air taken in from the second filter 26 passes through the second transport path 28 and the first transport path 27 to reach the toner storage section 16. The air that has passed through the first filter 18 and flowed into the air chamber 17 then passes through the intake switching section 36 and the air intake / exhaust means 135 and flows out from the exhaust switching section 37. As a result, as described above, at least a portion of the toner accumulated in the first transport path 27 and the second transport path 28 can be recovered into the toner storage section 16.

[0053] According to the configuration described above, even when Vp < V1 + V2 is set, toner replenishment and recovery of deposited toner can be performed. As a result, in toner conveyance by air, variations in the toner conveyance amount can be suppressed, and stable toner replenishment becomes possible.

[0054] <Method of Filling Toner into Toner Storage Unit C> FIG. 8 is a schematic cross-sectional view of the toner in the toner storage unit C showing the state when filling toner into the toner storage unit C. As shown in FIG. 8, when filling toner into the toner storage unit C, the posture of the toner storage unit C is set to the posture during replenishment with the top and bottom reversed from the posture during use. By inverting the top and bottom of the toner storage unit C in this way, the second outflow inlet 27b (discharge port) can be used as the filling port for the toner T. Further, when filling the toner T, for example, the air intake and exhaust means 35 is used to suck air from the air port 20. Thereby, the toner T is supplied to the toner storage portion 16 from the second outflow inlet 27b as the filling port through the first conveyance path 27.

[0055] ​​Since the first outlet 27a is located at the top of the toner storage section 16, filling can be continued without the first outlet 27a being buried in toner as the toner T is filled. In addition, in this embodiment, since the first outlet 27a is located near the center in the horizontal direction, the toner is ejected in a balanced manner horizontally. Furthermore, since the first outlet 27a is located in a position where toner can be easily discharged when the unit is installed in the image forming apparatus, when the unit is inverted, it is located in a position where filling is easy. Also, when the toner storage unit C is inverted, the top surface of the toner storage section 16 is covered by the first ventilation member 18, so the degassing efficiency is also good. There is no need to create a new opening for filling in the toner storage unit C, and therefore there is no need to create a new seal or lid to cover the filling opening. Furthermore, when recycling the toner storage unit C, it can be refilled using the second outlet 27b (discharge port) without disassembling it, so it is also recyclable.

[0056] The configurations of each of the above embodiments can be combined with each other as much as possible.

[0057] The disclosure of embodiments of the present invention includes the following configurations. (Composition 1) An image forming apparatus for forming an image on a recording material, A device body comprising: a photosensitive drum; a developing unit having a developer receiving port, and a developing roller that supplies the developer received from the receiving port to the photosensitive drum; A developer container that contains the developer and has an outlet, and is detachable from the main body of the apparatus, A developer transport path connecting the discharge port and the receiving port, In an image forming apparatus comprising, The main body of the apparatus has an intake and exhaust unit capable of performing an exhaust operation to supply air to the developer container and an intake operation to draw air from the developer container. The aforementioned intake and exhaust section is The exhaust operation creates a first flow of air that flows from the developer container through the developer transport path to the developing unit, thereby supplying the developer from the developer container to the developing unit. The aforementioned intake operation creates a second flow of air that flows from the developing unit through the developer transport path to the developer container. An image forming apparatus characterized by the following features. (Configuration 2) The aforementioned developer container is A developer storage chamber containing the developer and having the aforementioned outlet, A first filter that allows air to pass through but prevents the developer from passing through, An air chamber is separated from the developer storage chamber by the first filter and is provided with an air inlet for receiving air supplied from the intake and exhaust section, It has, The developing unit includes a developer storage section and a second filter between the developer storage section and the outside of the developing unit that allows air to pass through but prevents the developer from passing through. The first flow flows to the outside of the developing unit via the second filter. The second flow is formed by air flowing from outside the developing unit into the developer container via the second filter. The image forming apparatus described in Configuration 1. (Composition 3) The discharge port is configured to communicate with the inside of the developer storage chamber via a first pipe provided inside the developer storage chamber. The developer transport path is formed by a second pipe connecting the discharge port and the receiving port. The intake and exhaust section comprises a flexible container whose volume can be changed, and an intake and exhaust port that connects the inside and outside of the flexible container. It is configured such that when the volume of the flexible container decreases, air is exhausted to the outside through the intake and exhaust port, and when the volume of the flexible container increases, air is drawn in to the inside through the intake and exhaust port. The intake and exhaust port is connected to the developer storage chamber. When the volume of the first transport path using the first pipe is V1, the volume of the second transport path using the second pipe is V2, and the variable volume of the flexible container is Vp, Vp > V1 + V2 This means, An image forming apparatus according to configuration 1 or 2. (Composition 4) The intake and exhaust section is a bellows pump. An image forming apparatus according to any one of configurations 1 to 3. (Composition 5) The air chamber is located below the developer storage chamber. The opening of the first tube, which opens into the interior of the developer storage chamber, is opened so as to face the first filter. The first filter has a concave shape in which the region facing the opening of the first tube is most recessed downwards. An image forming apparatus according to any one of the configurations 1 to 4 characterized by the above. (Composition 6) The aforementioned intake and exhaust section is A volume variable section whose volume can be changed, A first intake path for drawing air into the variable volume section from the outside, A first exhaust path for exhausting from the variable volume section toward the developer storage chamber, A first intake valve for opening and closing the first intake path, the first intake valve which opens when the volume of the variable volume section increases and closes when the volume of the variable volume section decreases, A first exhaust valve for opening and closing the first exhaust path, the first exhaust valve which opens when the volume of the variable volume section decreases and closes when the volume of the variable volume section increases, It has, The exhaust operation is performed by the variable volume unit repeatedly increasing and decreasing in volume. An image forming apparatus according to configuration 1 or 2. (Composition 7) The aforementioned intake and exhaust section is A volume variable section whose volume can be changed, A second intake path for drawing air from the developer storage chamber to the variable volume section, A second exhaust path for exhausting from the variable volume section to the outside, A second intake valve for opening and closing the second intake path, the second intake valve which opens when the volume of the variable volume section increases and closes when the volume of the variable volume section decreases, A second exhaust valve for opening and closing the second exhaust path, the second exhaust valve which opens when the volume of the variable volume section decreases and closes when the volume of the variable volume section increases, It has, The intake operation is performed by the variable volume section repeatedly increasing and decreasing in volume. The image forming apparatus described in configuration 6. (Composition 8) The aforementioned intake and exhaust section is A first path is provided that connects the variable volume section and the developer storage chamber, and has a first opening in the middle that communicates with the outside, A first outside air valve that opens and closes the first opening, A first path valve that opens and closes the first path on the side of the first path closer to the developer storage chamber than the first opening, A second path, different from the first path, which connects the variable volume section and the developer storage chamber and has a second opening in the middle that communicates with the outside, A second outside air valve that opens and closes the second opening, A second path valve that opens and closes the second path on the side of the second path closer to the developer storage chamber than the second opening, It has, When the aforementioned exhaust operation is performed, The first outside air valve is open, the first pathway valve is closed, the second outside air valve is closed, and the second pathway valve is open. The first path forms the first intake path, The second path forms the first exhaust path, When the aforementioned intake operation is performed, The first external air valve is closed, the first pathway valve is open, the second external air valve is open, and the second pathway valve is closed. The first intake path forms the second intake path. The second path forms the second exhaust path. The image forming apparatus described in configuration 7. (Composition 9) The variable volume section is a diaphragm pump. An image forming apparatus according to any one of the configurations 6 to 8. (Composition 10) A method for filling a developer container, which is detachable from the main body of an image forming apparatus, The aforementioned developer container is A developer storage chamber containing the developer and equipped with a developer discharge port, A filter that allows air to pass through but prevents the developer from passing through, An air chamber is separated from the developer storage chamber by the filter and is provided with an air inlet for receiving air supplied from the intake and exhaust section of the main body of the apparatus, It has, The air chamber is configured to be mounted on the main body of the device in a position where it is located below the developer storage chamber. A method for filling a developer into a developer storage chamber, characterized in that the air chamber is positioned above the developer storage chamber, the discharge port is used as the developer filling port, and the developer is filled into the developer storage chamber from the discharge port while air is drawn in from the air inlet. [Explanation of Symbols]

[0058] B...Developing unit, C...Toner storage unit, T...Toner, D1...Pump volume decreasing direction, D2...Pump volume increasing direction, F1...Airflow during toner replenishment, F2...Airflow during accumulated toner recovery, F3...Airflow during toner replenishment, F4...Airflow during accumulated toner recovery, 1...Photosensitive drum, 2...Developing roller, 3...Toner cartridge, 13...Agitation member, 16...Toner storage section, 17...Air chamber, 18...First ventilation member, 20...Air port, 21...Air pipe, 24...Inlet, 26...Second ventilation member, 27...First discharge path, 27a...First outlet, 27b...Second flow Inlet / outlet, 35...Air intake / exhaust means, 35a...Volume changing section, 35b...Intake path, 35c...Exhaust path, 35d...Intake path valve, 35e...Exhaust path valve, 36...Intake switching section, 36a...Air inlet side intake valve, 36b...Outside air side intake valve, 37...Exhaust switching section, 37a...Air inlet side exhaust valve, 37b...Outside air side exhaust valve, 135...Air intake / exhaust means, 135a...Volume changing section, 135b...Intake path, 135c...Exhaust path, 135d...Intake path valve, 135e...Exhaust path valve

Claims

1. An image forming apparatus for forming an image on a recording material, A device body comprising: a photosensitive drum; a developing unit having a developer receiving port, and a developing roller for supplying the developer received from the receiving port to the photosensitive drum; A developer container that contains the developer and has an outlet, and is detachable from the main body of the device, A developer transport path connecting the discharge port and the receiving port, In an image forming apparatus comprising, The main body of the apparatus has an intake and exhaust unit capable of performing an exhaust operation to supply air to the developer container and an intake operation to draw air from the developer container. The aforementioned intake and exhaust section is The exhaust operation creates a first flow of air that flows from the developer container through the developer transport path to the developing unit, thereby supplying the developer from the developer container to the developing unit. The aforementioned intake operation creates a second flow of air that flows from the developing unit through the developer transport path to the developer container. An image forming apparatus characterized by the following features.

2. The aforementioned developer container is A developer storage chamber containing the developer and having the aforementioned outlet, A first filter that allows air to pass through but prevents the developer from passing through, An air chamber is separated from the developer storage chamber by the first filter and is provided with an air inlet for receiving air supplied from the intake and exhaust section, It has, The developing unit includes a developer storage section and a second filter between the developer storage section and the outside of the developing unit that allows air to pass through but prevents the developer from passing through. The first flow flows to the outside of the developing unit via the second filter. The second flow is formed by air flowing from outside the developing unit into the developer container via the second filter. The image forming apparatus according to claim 1.

3. The discharge port is configured to communicate with the inside of the developer storage chamber via a first pipe provided inside the developer storage chamber. The developer transport path is formed by a second pipe connecting the discharge port and the receiving port. The intake and exhaust section comprises a flexible container whose volume can be changed, and an intake and exhaust port that connects the inside and outside of the flexible container. It is configured such that when the volume of the flexible container decreases, air is exhausted to the outside through the intake and exhaust port, and when the volume of the flexible container increases, air is drawn in to the inside through the intake and exhaust port. The intake and exhaust port is connected to the developer storage chamber. When the volume of the first transport path using the first pipe is V1, the volume of the second transport path using the second pipe is V2, and the variable volume of the flexible container is Vp, Vp > V1 + V2 This means, The image forming apparatus according to claim 2.

4. The intake and exhaust section is a bellows pump. The image forming apparatus according to claim 3.

5. The air chamber is located below the developer storage chamber. The opening of the first tube, which opens into the interior of the developer storage chamber, is opened so as to face the first filter. The first filter has a concave shape in which the region facing the opening of the first tube is most recessed downwards. The image forming apparatus according to feature 3.

6. The aforementioned intake and exhaust section is A volume variable section whose volume can be changed, A first intake path for drawing air into the variable volume section from the outside, A first exhaust path for exhausting from the variable volume section toward the developer storage chamber, A first intake valve for opening and closing the first intake path, the first intake valve which opens when the volume of the variable volume section increases and closes when the volume of the variable volume section decreases, A first exhaust valve for opening and closing the first exhaust path, the first exhaust valve which opens when the volume of the variable volume section decreases and closes when the volume of the variable volume section increases, It has, The exhaust operation is performed by the variable volume unit repeatedly increasing and decreasing in volume. The image forming apparatus according to claim 2.

7. The aforementioned intake and exhaust section is A volume variable section whose volume can be changed, A second intake path for drawing air from the developer storage chamber to the variable volume section, A second exhaust path for exhausting from the variable volume section to the outside, A second intake valve for opening and closing the second intake path, the second intake valve which opens when the volume of the variable volume section increases and closes when the volume of the variable volume section decreases, A second exhaust valve for opening and closing the second exhaust path, the second exhaust valve which opens when the volume of the variable volume section decreases and closes when the volume of the variable volume section increases, It has, The intake operation is performed by the variable volume section repeatedly increasing and decreasing in volume. The image forming apparatus according to claim 6.

8. The aforementioned intake and exhaust section is A first path is provided that connects the variable volume section and the developer storage chamber, and has a first opening in the middle that communicates with the outside, A first outside air valve that opens and closes the first opening, A first path valve that opens and closes the first path on the side of the first path closer to the developer storage chamber than the first opening, A second path, different from the first path, which connects the variable volume section and the developer storage chamber and has a second opening in the middle that communicates with the outside, A second outside air valve that opens and closes the second opening, A second path valve that opens and closes the second path on the side of the second path that is closer to the developer storage chamber than the second opening, It has, When the aforementioned exhaust operation is performed, The first outside air valve is open, the first pathway valve is closed, the second outside air valve is closed, and the second pathway valve is open. The first path forms the first intake path, The second path forms the first exhaust path, When the aforementioned intake operation is performed, The first outside air valve is closed, the first pathway valve is open, the second outside air valve is open, and the second pathway valve is closed. The first path forms the second intake path, The second path forms the second exhaust path. The image forming apparatus according to claim 7.

9. The variable volume section is a diaphragm pump. The image forming apparatus according to claim 6.

10. A method for filling a developer container, which is detachable from the main body of an image forming apparatus, The aforementioned developer container is A developer storage chamber containing the developer and equipped with a developer discharge port, A filter that allows air to pass through but prevents the developer from passing through, An air chamber is separated from the developer storage chamber by the filter and is provided with an air inlet for receiving air supplied from the intake and exhaust section of the main body of the apparatus, It has, The air chamber is configured to be mounted on the main body of the device in a position where it is located below the developer storage chamber. A method for filling a developer into a developer storage chamber, characterized in that the air chamber is positioned above the developer storage chamber, the discharge port is used as the developer filling port, and air is drawn in from the air inlet while the developer is filled into the developer storage chamber from the discharge port.

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