Powder conveying apparatus and image forming apparatus

Abstract

This effectively prevents powder accumulation and aggregation in the powder drop path. [Solution] The waste toner transport unit (powder transport device) 7 comprises a waste toner drop path (powder drop path) 51 through which waste toner (powder) falls by its own weight, a second transport path (powder transport path) 61 connected to the lower part of the waste toner drop path 51 and extending in a direction intersecting the waste toner drop path 51, a second transport spiral (transport member) 62 provided in the second transport path 61 and transporting the waste toner along the second transport path 61 in a predetermined transport direction by rotating, and an agitation member 80 provided in the waste toner drop path 51 and having a swinging part 83 that swings within the waste toner drop path 51 by contact with the second transport spiral 62. The swinging part 83 of the agitation member 80 swings such that the upper end 83a and the lower end 83b move in opposite directions to each other.

Description

Technical Field

[0001] The present disclosure relates to a powder conveying device for conveying powders such as toner, and an image forming apparatus including the powder conveying device.

Background Art

[0002] Some image forming apparatuses using the electrophotographic method include a dropping path for dropping used powders such as waste toner by their own weight. For example, Patent Document 1 discloses providing a film-shaped stirring member to prevent retention and aggregation of powders (waste toner) in the dropping path.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, in the conventional configuration, there is a problem that the stirring action of the stirring member on the powder is weak in the vicinity of the inlet portion (upper end portion) of the dropping path for dropping powders such as waste toner by their own weight, and retention and aggregation of the powder cannot be sufficiently prevented.

[0005] The present disclosure has been made to solve the above problems, and an object thereof is to effectively prevent retention and aggregation of powders such as waste toner.

Means for Solving the Problems

[0006] The powder conveying apparatus of this disclosure comprises: a powder drop path through which powder falls by its own weight; a powder conveying path connected to the lower part of the powder drop path and extending in a direction intersecting the powder drop path; a conveying member provided in the powder conveying path and conveying the powder along the powder conveying path by rotating; and a stirring member provided in the powder drop path and having a rocking part that rocks within the powder drop path by contact with the conveying member. The rocking part of the stirring member rocks such that its upper end and lower end move in opposite directions to each other. [Effects of the Invention]

[0007] According to this disclosure, since the oscillating part of the stirring member oscillates such that its upper end and lower end move in opposite directions, the powder near the inlet and outlet of the powder drop channel can be efficiently stirred, and the aggregation and accumulation of the powder can be effectively prevented. [Brief explanation of the drawing]

[0008] [Figure 1] This is a diagram showing the overall configuration of the image forming apparatus of Embodiment 1. [Figure 2] This diagram shows the configuration of the process unit according to Embodiment 1. [Figure 3] This is a plan view showing the positional relationships of the various parts of the image forming apparatus of Embodiment 1. [Figure 4] This is a side view showing the waste toner collection unit of Embodiment 1. [Figure 5] This is a partially cutaway perspective view showing the waste toner drop path and its surroundings in Embodiment 1. [Figure 6] This is a cross-sectional view showing the waste toner drop path and its surroundings in Embodiment 1. [Figure 7] These are perspective views (A) and (B) showing the stirring member of Embodiment 1. [Figure 8] These are cross-sectional views (A) and (B) showing the operation of the stirring member in Embodiment 1. [Figure 9] This is a partially cutaway perspective view showing the waste toner drop path and its surroundings in Embodiment 1. [Figure 10]This is a perspective view showing a modified stirring member. [Figure 11] This is a partially cutaway perspective view showing the waste toner drop path and its surroundings in Embodiment 2. [Figure 12] This is a cross-sectional view showing the waste toner drop path and its surroundings in Embodiment 2. [Figure 13] This is a perspective view showing the stirring member of Embodiment 2. [Figure 14] These are cross-sectional views (A) and (B) showing the operation of the stirring member in Embodiment 2. [Figure 15] Figures (A) and (B) show the changes in the state of the waste toner transport section when the process unit of Embodiment 2 is attached or detached. [Figure 16] Figures (A) and (B) show the change in the positional relationship between the sponge and the stirring member when the process unit of Embodiment 2 is attached or detached. [Modes for carrying out the invention]

[0009] Embodiment 1. <Configuration of an image forming apparatus> Figure 1 shows the internal configuration of the image forming apparatus 1 of Embodiment 1. The image forming apparatus 1 forms images using electrophotography and is, for example, a color printer. However, the image forming apparatus 1 of Embodiment 1 may be a monochrome printer, a facsimile machine, a multifunction device, etc.

[0010] As shown in Figure 1, the image forming apparatus 1 comprises a medium supply unit 110 for supplying a medium P such as printing paper, process units 10K, 10C, 10M, and 10Y as image forming units for forming toner images (developer images), a transfer unit 30 for transferring the toner images to the medium P, a fixing device 120 for fixing the toner images to the medium P, a medium discharge unit 130 for discharging the medium P, and an apparatus housing 100 for housing these. The upper part of the apparatus housing 100 is covered with an openable and closable top cover 102.

[0011] The media supply unit 110 includes a paper feed tray 111 for accommodating the media P, a pickup roller 112 arranged to abut against the media P accommodated in the paper feed tray 111, a feed roller 113 arranged adjacent to the pickup roller 112, and a retard roller 114 arranged to face the feed roller 113.

[0012] The paper feed tray 111 accommodates the media P such as printing paper in a stacked state. The pickup roller 112 rotates while abutting against the surface of the uppermost media P in the paper feed tray 111, and pulls out the media P from the paper feed tray 111. The feed roller 113 sends out the media P pulled out by the pickup roller 112 to the paper feed conveyance path R1. The retard roller 114 imparts conveyance resistance to the media P sent out by the feed roller 113 to prevent double feeding.

[0013] The media supply unit 110 also has a pair of conveyance rollers 115 and a pair of conveyance rollers 116 along the paper feed conveyance path R1. The pair of conveyance rollers 115 is composed of a registration roller and a pinch roller, and corrects and conveys the skew of the media P by starting rotation at a predetermined timing after the leading end of the media P abuts against the nip portion of both rollers. The pair of conveyance rollers 116 conveys the media P from the pair of conveyance rollers 115 to the transfer unit 30.

[0014] The process units 10K, 10C, 10M, 10Y are arranged in this order in the conveyance direction of the media P (from left to right in FIG. 1). The process units 10K, 10C, 10M, 10Y are parts for forming toner images of black, cyan, magenta, and yellow. Since the process units 10K, 10C, 10M, 10Y have a common configuration except for the toner, they are referred to as "process unit 10" when there is no particular need to distinguish them. The process unit 10 is provided detachably with respect to the apparatus housing 100.

[0015] Figure 2 is a cross-sectional view showing the configuration of the process unit 10. The process unit 10 includes a photoreceptor drum 11 as an image carrier, a charging roller 12 as a charging member, a developing roller 14 as a developer carrier, a supply roller 15 as a supply member, a developing blade 16 as a layer regulating member, a cleaning member 17, a static eliminator 18, and a unit frame 105 that houses these components. In addition, a print head 13 as an exposure device is suspended from the top cover 102 (Figure 1) so as to face the photoreceptor drum 11.

[0016] The photoreceptor drum 11 is a cylindrical member having a photosensitive layer (charge generation layer and charge transport layer) on the surface of a conductive substrate, and rotates counterclockwise in the figure by the driving force of the drive motor.

[0017] The charging roller 12 is positioned to contact the surface of the photoreceptor drum 11 and rotates in accordance with the rotation of the photoreceptor drum 11. The charging roller 12 is subjected to a charging voltage by a charging voltage power supply, uniformly charging the surface of the photoreceptor drum 11.

[0018] The print head 13 has an array of light-emitting elements such as LEDs (light-emitting diodes) arranged together, and a lens array that focuses the light emitted from the light-emitting elements onto the surface of the photoreceptor drum 11. The print head 13 exposes the surface of the photoreceptor drum 11 to form an electrostatic latent image.

[0019] The developing roller 14 is positioned to contact the surface of the photoreceptor drum 11 and rotates in the opposite direction to the photoreceptor drum 11 (clockwise in the diagram). The developing roller 14 is subjected to a developing voltage by a developing voltage power supply, and deposits toner onto the electrostatic latent image formed on the surface of the photoreceptor drum 11, thereby forming a toner image.

[0020] The supply roller 15 is positioned to contact or face the surface of the developing roller 14 and rotates in the same direction as the developing roller 14 (clockwise in the figure). The supply roller 15 is supplied with a supply voltage by a supply voltage power supply and supplies toner to the developing roller 14.

[0021] The developing blade 16 is a long metal blade in the axial direction of the developing roller 14 and is positioned to press against the surface of the developing roller 14. The developing blade 16 regulates the thickness of the toner layer formed on the surface of the developing roller 14.

[0022] The cleaning member 17 is positioned upstream of the charging roller 12 and downstream of the transfer roller 31 (described later) in the rotational direction of the photoreceptor drum 11. The cleaning member 17 is a blade made of an elastic material such as urethane rubber and is pressed against the surface of the photoreceptor drum 11. The cleaning member 17 removes toner remaining on the surface of the photoreceptor drum 11 after the transfer of the toner image. The toner scraped off from the photoreceptor drum 11 by the cleaning member 17 is called waste toner.

[0023] Below the cleaning member 17, a waste toner discharge section 40 is provided for discharging waste toner from the process unit 10. The waste toner discharge section 40 has a first transport path 41 that extends parallel to the axial direction (X direction, described later) of the photoreceptor drum 11, and a first transport spiral 42 provided inside the first transport path 41. The first transport spiral 42 transports the waste toner to the back of the paper (+X direction, described later). The first transport path 41 is also called a powder discharge path. The first transport spiral 42 is also called a transport mechanism.

[0024] The static elimination device 18 is positioned upstream of the charging roller 12 and downstream of the cleaning member 17 in the rotational direction of the photoreceptor drum 11. The static elimination device 18 has an LED and irradiates the surface of the photoreceptor drum 11 with static elimination light, thereby uniformly reducing the surface potential of the photoreceptor drum 11 to zero in the axial direction.

[0025] As shown in Figure 1, toner cartridges 20K, 20C, 20M, and 20Y, which serve as developer housings, are positioned above the process units 10K, 10C, 10M, and 10Y. The toner cartridges 20K, 20C, 20M, and 20Y are detachably attached to the top cover 102. The toner cartridges 20K, 20C, 20M, and 20Y each contain black, cyan, magenta, and yellow toner, respectively.

[0026] The transfer unit 30 includes transfer rollers 31 positioned opposite each photoreceptor drum 11 of process units 10K, 10C, 10M, and 10Y, an endless transfer belt 32 provided to pass between the photoreceptor drum 11 and the transfer rollers 31, and drive rollers 33 and tension rollers 34 on which the transfer belt 32 is stretched.

[0027] The drive roller 33 rotates due to the driving force of the belt drive motor, causing the transfer belt 32 to move. The transfer belt 32 moves while holding the medium P on its surface by electrostatic force. The tension roller 34 applies tension to the transfer belt 32. The transfer roller 31 is subjected to a transfer voltage by the transfer voltage power supply and transfers the toner image on each photoreceptor drum 11 to the medium P on the transfer belt 32.

[0028] The transfer unit 30 also includes a belt cleaning member 35 for removing residual toner on the transfer belt 32, and a waste toner storage section 36 for storing the residual toner removed by the belt cleaning member 35.

[0029] The fixing device 120 is positioned downstream of the process units 10K, 10C, 10M, 10Y and the transfer unit 30 in the transport direction of the medium P. The fixing device 120 includes a fixing member 121 and a pressure roller 122. The fixing member 121 is a roller or belt heated by a heater and rotated by the driving force of a fixing motor. The pressure roller 122 is pressed against the fixing member 121 to form a fixing nip. The fixing member 121 and the pressure roller 122 apply heat and pressure to the toner image transferred to the medium P, fixing it to the medium P.

[0030] The media discharge section 130 is located downstream of the fixing device 120 in the media P transport direction and is equipped with a pair of discharge rollers 131. The pair of discharge rollers 131 transports the media P sent from the fixing device 120 along the discharge transport path R2 and discharges it to the outside through the discharge port 132. A stacker section 135 for stacking the media P discharged from the discharge port 132 is provided on the upper part of the top cover 102.

[0031] The image forming apparatus 1 also has an openable and closable top cover 102 attached to the top of the apparatus housing 100, and an openable and closable front cover 101 attached to the front of the apparatus housing 100. The toner cartridges 20K, 20C, 20M, and 20Y mentioned above are attached to the top cover 102.

[0032] In Figure 1, the direction of the rotation axis of the photoreceptor drum 11 is defined as the X direction. The X direction is the width direction of the medium P. The axial direction of each roller in each of the units described above is parallel to the X direction. The direction of movement of the medium P as it passes through process units 10K, 10C, 10M, and 10Y is defined as the Y direction. The direction perpendicular to the XY plane is defined as the Z direction.

[0033] For the Y direction, the direction of movement of the medium P as it passes through process units 10K, 10C, 10M, and 10Y is defined as the -Y direction (rearward), and the opposite direction is defined as the +Y direction (forward). For the X direction, the front side of Figure 1 is defined as the -X direction, and the back side is defined as the +X direction. Note that in Figure 1, etc., the XY plane is inclined with respect to the horizontal plane, but it is not necessarily required to be inclined.

[0034] Figure 3 is a schematic diagram showing the arrangement of each unit in the image forming apparatus 1. As shown in Figure 3, the process units 10K, 10C, 10M, and 10Y have a long shape in the X direction and are arranged in a single line in the Y direction. On the other hand, the toner cartridges 20K, 20C, 20M, and 20Y have a long shape in the Y direction and are arranged in the X direction.

[0035] Between the toner cartridges 20K, 20C, 20M, and 20Y (referred to as toner cartridge 20 unless otherwise specified) and the process units 10K, 10C, 10M, and 10Y, toner supply paths called toner ducts 22K, 22C, 22M, and 22Y are provided.

[0036] The toner ducts 22K, 22C, 22M, and 22Y (referred to as toner duct 22 unless otherwise specified) have connecting parts 21K, 21C, 21M, and 21Y connected to toner cartridges 20K, 20C, 20M, and 20Y, and connecting parts 19K, 19C, 19M, and 19Y (referred to as connecting part 19 unless otherwise specified) connected to process units 10K, 10C, 10M, and 10Y. The connecting parts 21K, 21C, 21M, and 21Y are arranged in a single line in the X direction, for example. The connecting parts 19K, 19C, 19M, and 19Y are arranged in a single line in the Y direction, for example.

[0037] As shown in Figure 2, the connection part 19 is connected to the upper part of the unit frame 105 of the process unit 10 (more specifically, above the developing roller 14 and the supply roller 15). The toner contained in the toner cartridge 20 is supplied from the connection part 19 to the process unit 10 via the toner duct 22.

[0038] Although this example describes a configuration where the toner cartridge 20 and the process unit 10 are connected by a toner duct 22, the example is not limited to this configuration, and the toner cartridge 20 may be detachably mounted on the process unit 10.

[0039] <Waste Toner Transport Unit 7> Figure 4 is a side view showing the waste toner transport unit 7, which functions as a powder transport device for transporting and collecting waste toner from process units 10K, 10C, 10M, and 10Y.

[0040] In each process unit 10, waste toner scraped from the photoreceptor drum 11 by the cleaning member 17 is transported in the +X direction within the first transport path 41 by the first transport spiral 42.

[0041] A waste toner drop path 51 is provided at the +X end of the first transport path 41 (i.e., the end of the waste toner transport direction). The waste toner drop path 51 is the section that allows the waste toner transported to the +X end of the first transport path 41 to fall by its own weight. The waste toner drop path 51 and the inner duct 55, which will be described later, together are also called the powder drop path.

[0042] Each waste toner drop path 51 provided in process units 10K, 10C, 10M, and 10Y is connected to a second transport path 61 which serves as a powder transport path extending in the Y direction. The second transport path 61 is provided with a second transport spiral 62 (see Figure 5) which serves as a transport member for transporting waste toner in the +Y direction.

[0043] A connecting pipe 66 is connected to the +Y end of the second transport path 61. The connecting pipe 66 is connected to a connection part 67 of a waste toner collection container 68, which serves as a powder recovery container. The waste toner transported along the second transport path 61 is collected in the waste toner collection container 68 via the connecting pipe 66.

[0044] As shown in Figure 3, the waste toner collection container 68 is located in the +X direction of the process units 10K, 10C, 10M, and 10Y within the apparatus housing 100 of the image forming apparatus 1. The waste toner collection container 68 can be removed from the front (+Y direction) of the apparatus housing 100.

[0045] The waste toner collection section 60 is comprised of the second transport path 61, the second transport spiral 62, and the waste toner collection container 68. Furthermore, the waste toner transport section 7, which functions as a powder transport device, is comprised of the waste toner discharge section 40, the waste toner drop path 51, and the waste toner collection section 60.

[0046] Figure 5 is a partially cutaway perspective view showing the waste toner drop path 51 and its surroundings. Figure 6 is a cross-sectional view showing the waste toner drop path 51 and its surroundings. Note that in Figure 5, only the +X end of the first transport path 41 of the waste toner discharge section 40 is shown.

[0047] As shown in Figure 6, the waste toner discharge section 40 has a first transport path 41 which is a duct extending in the X direction, and a first transport spiral 42 provided inside the first transport path 41. The first transport spiral 42 is made of a wire made of metal such as stainless steel, wound spirally around a rotation axis in the X direction.

[0048] A first drive gear (not shown) is attached to the -X end of the first transport spiral 42. Rotation from the photoreceptor drum 11 is transmitted to the first drive gear. As a result, the first transport spiral 42 rotates around its axis of rotation in the X direction, transporting the waste toner in the +X direction.

[0049] An outlet 44 for discharging waste toner downwards is formed at the +X end 43 of the first transport path 41. The waste toner transported in the +X direction by the first transport spiral 42 is discharged from the outlet 44.

[0050] As shown in Figure 5, the waste toner drop path 51 connects the first transport path 41 and the second transport path 61. More specifically, the waste toner drop path 51 extends to connect the +X end 43 of the first transport path 41 to the second transport path 61. The direction of extension of the waste toner drop path 51 is in the Z direction here, and is inclined with respect to the vertical direction, but it may also be in the vertical direction.

[0051] In other words, the direction of the waste toner drop path 51 only needs to be such that waste toner can fall within the waste toner drop path 51. Furthermore, in relation to the directions of the first transport path 41 and the second transport path 61, the direction of the waste toner drop path 51 only needs to intersect with the direction of the first transport path 41 and with the direction of the second transport path 61.

[0052] The waste toner drop path 51 is, for example, a duct having a rectangular cross-sectional shape. The waste toner drop path 51 has a wall portion 51a facing the -Y direction, a wall portion 51b facing the +Y direction, a wall portion 51c (Figure 6) facing the -X direction, and a wall portion 51d (Figure 6) facing the +X direction.

[0053] The waste toner drop path 51 has an inlet 52 at its upper end and an outlet 53 at its lower end. The inlet 52 faces the outlet 44 of the first transport path 41. Waste toner discharged from the outlet 44 of the first transport path 41 enters the waste toner drop path 51 from the inlet 52. The outlet 53 communicates with the second transport path 61.

[0054] An inner duct 55 is located inside the waste toner drop path 51. A passage for waste toner is formed inside the inner duct 55. The inner duct 55 has a first inner wall portion 55a located in wall portion 51a, a second inner wall portion 55b located in wall portion 51b (Figure 6), a third inner wall portion 55c located in wall portion 51c, and a fourth inner wall portion 55d located in wall portion 51d (Figure 6).

[0055] Furthermore, a flange portion 55e is formed at the upper end (the end in the +Z direction) of the inner duct 55. A sponge 56 is placed above the flange portion 55e, and a sponge 57 is placed below the flange portion 55e. The sponge 56 is in contact with the area around the discharge port 44 of the waste toner discharge section 40. The sponge 57 is sandwiched between the flange portion 55e of the inner duct 55 and the upper end of the waste toner drop path 51.

[0056] The inner duct 55 is a movable duct that can move along the inner surface of the waste toner drop path 51 and is biased upward (+Z direction) by a biasing member 58 such as a coil spring (Figure 11, described later). When the first transport path 41 and the waste toner drop path 51 are connected and disconnected, the inner duct 55 moves up and down relative to the waste toner drop path 51. This will be explained in Embodiment 2.

[0057] Here, we will describe an example in which an inner duct 55 is provided within the waste toner drop path 51, but the example is not limited to this. For example, instead of providing an inner duct 55, a stirring member 80 (described later) may be provided on the inner surface of the waste toner drop path 51.

[0058] As described above, the waste toner collection unit 60 has a second transport path 61 which is a duct extending in the Y direction, and a second transport spiral 62 which is a transport member provided inside the second transport path 61. The second transport spiral 62 is made of a wire made of metal such as stainless steel wound in a spiral shape, and rotates around a rotation axis in the Y direction to transport the waste toner in the +Y direction.

[0059] A second drive gear 65 for rotating the second transport spiral 62 is attached to the -Y end 63 of the second transport path 61. The end of the second transport spiral 62 is fixed to the second drive gear 65. The rotation of the waste toner collection motor is transmitted to the second drive gear 65, which causes the second transport spiral 62 to rotate.

[0060] The outlet 53 of the waste toner drop path 51 is connected to the upper part of the second transport path 61. The waste toner that has fallen through the waste toner drop path 51 enters the second transport path 61 from the outlet 53 and is transported in the +Y direction by the second transport spiral 62.

[0061] <Agitation component 80> Next, the stirring member 80 will be described. Inside the waste toner drop channel 51, a stirring member 80 is provided to prevent the accumulation and aggregation of waste toner. The stirring member 80 extends from near the inlet 52 of the waste toner drop channel 51 to a position where it contacts the second transport spiral 62 in the second transport channel 61.

[0062] Figures 7(A) and 7(B) are perspective views of the stirring member 80 from different angles. The stirring member 80 is formed by bending a film made of a flexible resin such as PET (polyethylene terephthalate).

[0063] The stirring member 80 has a fixed portion 81, a flexible portion 82, an oscillating portion 83, a connecting portion 84, and sliding portions 85 and 86. The stirring member 80 is V-shaped when viewed in the X direction, with the fixed portion 81 and the flexible portion 82 located on one side (-Y side), and the oscillating portion 83 and the sliding portions 85 and 86 located on the other side (+Y side). The connecting portion 84 is located between the flexible portion 82 and the oscillating portion 83.

[0064] The fixing portion 81 is fixed to the first inner wall portion 55a (Figure 5) of the inner duct 55, for example, by double-sided tape 89. The fixing portion 81 is a long strip in the Z direction and has a width in the X direction. The edge forming the -X end of the fixing portion 81 is called edge 81a, and the edge forming the +X end of the fixing portion 81 is called edge 81b. Here, edges 81a and 81b extend parallel to each other.

[0065] The flexible portion 82 is formed below the fixed portion 81 (in the -Z direction) and is continuous with the fixed portion 81. Since the flexible portion 82 is not fixed to the inner duct 55, it can bend (elastically deform) around the portion connected to the fixed portion 81.

[0066] The edge forming the -X end of the flexible portion 82 is called edge 82a, and the edge forming the +X end of the flexible portion 82 is called edge 82b. Edge 82a of the flexible portion 82 is inclined with respect to edge 81a of the fixed portion 81. Edge 82b of the flexible portion 82 is a straight line extending from edge 81b of the fixed portion 81. Therefore, the width of the flexible portion 82 in the X direction becomes narrower towards the bottom (-Z direction).

[0067] The oscillating portion 83 is opposed to the fixed portion 81 and the flexible portion 82 in the Y direction. The oscillating portion 83 is a long, strip-shaped object in the Z direction and has width in the X direction. The upper end portion 83a of the oscillating portion 83 reaches the entrance portion 52 (Figure 5) of the waste toner drop path 51. The lower end portion 83b of the oscillating portion 83 is in a position to contact the second transport spiral 62 (Figure 5) in the second transport path 61.

[0068] The side forming the -X end of the oscillating part 83 is called side 83c, and the side forming the +X end of the oscillating part 83 is called side 83d. Here, sides 83c and 83d are parallel to each other.

[0069] The connecting portion 84 extends from the lower end of the side 82b of the flexible portion 82 to the side 83d of the oscillating portion 83. The flexible portion 82 and the oscillating portion 83 are connected by this connecting portion 84.

[0070] As shown in Figure 7(A), a sliding portion 85 is formed along the edge 83c of the oscillating portion 83. The sliding portion 85 protrudes in the -Y direction toward the fixed portion 81. The edge forming the -Y end of the sliding portion 85 is referred to as edge 85a, and the edge forming the -Z end of the sliding portion 85 is referred to as edge 85b.

[0071] The side 85a of the sliding part 85 is inclined such that the amount of protrusion of the sliding part 85 in the -Y direction increases as it goes downward (-Z direction). The side 85b of the sliding part 85 is approximately perpendicular to the side 83c of the oscillating part 83. A curved (preferably arc-shaped) contact portion 87 is formed between sides 85a and 85b. The contact portion 87 is the part that contacts the fixed part 81, as will be described later.

[0072] As shown in Figure 7(B), a sliding portion 86 is formed along the edge 83d of the oscillating portion 83. The sliding portion 86 protrudes in the -Y direction toward the fixed portion 81. The edge forming the -Y end of the sliding portion 86 is referred to as edge 86a, and the edge forming the -Z end of the sliding portion 86 is referred to as edge 86b.

[0073] The side 86a of the sliding part 86 is inclined such that the amount of protrusion of the sliding part 86 in the -Y direction increases as it goes downward (-Z direction). The side 86b of the sliding part 86 is approximately perpendicular to the side 83d of the oscillating part 83. A curved (preferably arc-shaped) contact portion 88 is formed between sides 86a and 86b. The contact portion 88 is the part that contacts the fixed part 81, as will be described later.

[0074] It is desirable that the stirring member 80 is formed entirely from a single film that has been folded. Specifically, the connecting portion 84 is formed by folding the film along the side 82b of the flexible portion 82. The oscillating portion 83 is formed by folding the film along the side of the connecting portion 84 opposite to the flexible portion 82. The sliding portions 85 and 86 are formed by folding the film along the sides 83c and 83d of the oscillating portion 83.

[0075] However, the stirring member 80 is not limited to being formed by folding a single film, but may be made by combining multiple films.

[0076] Figures 8(A) and 8(B) are cross-sectional views illustrating the operation of the stirring member 80. In the state shown in Figure 8(A), the lower end portion 83b of the oscillating portion 83 of the stirring member 80 is inside the range of movement of the second conveying spiral 62 (shown by the dotted line), but it is not in contact with the wire of the second conveying spiral 62.

[0077] In this state, the flexible portion 82 of the stirring member 80 is not bent and extends linearly in the -Z direction from the fixed portion 81. At this time, the upper end portion 83a of the oscillating portion 83 is located at the inlet portion 52 of the waste toner drop path 51 and is in contact with the second inner wall portion 55b of the inner duct 55.

[0078] As shown in Figure 8(B), when the second conveying spiral 62 rotates, the lower end portion 83b of the oscillating portion 83 comes into contact with the wire of the second conveying spiral 62 and moves in the +Y direction. As a result, the flexible portion 82, which is connected to the oscillating portion 83 by the connecting portion 84, bends in the +Y direction around the joint portion with the fixed portion 81.

[0079] As the oscillating part 83 flexes, the contact parts 87 and 88 of the sliding parts 85 and 86 provided on the oscillating part 83 come into contact with the fixed part 81, and the oscillating part 83 oscillates with the contact parts 87 and 88 as pivot points. As a result, the upper end 83a of the oscillating part 83 moves in the -Y direction. In other words, the oscillating part 83 oscillates such that the upper end 83a and the lower end 83b move in opposite directions (-Y direction and +Y direction).

[0080] The pivot point of the swinging part 83 (the position where the sliding parts 85 and 86 contact the fixed part 81) is preferably the center in the Z direction of the waste toner drop path 51. However, it does not need to be exactly the center in the Z direction of the waste toner drop path 51; it is sufficient if it is between the upper end (inlet part 52) ​​and the lower end (outlet part 53) of the waste toner drop path 51.

[0081] Figure 9 is a partially cutaway perspective view showing the state shown in Figure 8(B). As the second conveying spiral 62 rotates further, just before the lower end 83b of the oscillating part 83 and the wire of the second conveying spiral 62 lose contact, the lower end 83b of the oscillating part 83 reaches the vicinity of the +Y end of the outlet part 53, and the upper end 83a of the oscillating part 83 contacts the first inner wall 55a of the inner duct 55.

[0082] As the second conveying spiral 62 rotates further and the contact between the lower end 83b of the oscillating section 83 and the wire of the second conveying spiral 62 is released, the stirring member 80 returns to the state before the bending section 82 was bent, as shown in Figure 8(A). As a result, the upper end 83a of the oscillating section 83 moves in the +Y direction, and the lower end 83b moves in the -Y direction.

[0083] In this way, as the second conveying spiral 62 rotates, the oscillating portion 83 of the stirring member 80 oscillates such that its upper end 83a and lower end 83b move in opposite directions. As a result, the stirring member 80 stirs the waste toner throughout the entire waste toner drop path 51 (especially near the inlet 52 and the outlet 53).

[0084] In Figure 8(A), it is most desirable for the upper end portion 83a of the oscillating portion 83 to contact the second inner wall portion 55b, but it may also be in a position close to the second inner wall portion 55b. Similarly, in Figure 8(B), it is most desirable for the upper end portion 83a of the oscillating portion 83 to contact the first inner wall portion 55a, but it may also be in a position close to the first inner wall portion 55a. In either case, the effect of preventing waste toner from accumulating near the upper end portion (inlet portion 52) of the waste toner drop path 51 can be obtained.

[0085] As the oscillating part 83 oscillates, the sliding parts 85 and 86 move while contacting the inner walls 55c and 55d of the inner duct 55. This prevents waste toner from adhering to the inner walls 55c and 55d of the inner duct 55. While it is most desirable for the sliding parts 85 and 86 to be in contact with the inner walls 55c and 55d, they may also be in a position close to the inner walls 55c and 55d, and the effect of preventing waste toner adhesion will still be obtained.

[0086] <Operation of the image forming apparatus> Next, the printing operation by the image forming apparatus 1 will be explained with reference to Figure 1. When the control device of the image forming apparatus 1 receives a print command and print data from a higher-level device such as a personal computer, it starts the printing operation.

[0087] At the start of printing, the media supply unit 110 begins supplying the media P. Specifically, the pickup roller 112 pulls the media P from the paper tray 111, and the feed roller 113 sends the media P to the paper feed transport path R1. The transport roller pairs 115 and 116 then transport the media P sent to the paper feed transport path R1 toward the transfer unit 30.

[0088] In the transfer unit 30, the drive roller 33 rotates to move the transfer belt 32. The transfer belt 32 adsorbs, holds, and transports the medium P. The medium P passes through the process units 10K, 10C, 10M, and 10Y in that order.

[0089] In each process unit 10, a charging voltage, a developing voltage, and a supply voltage are applied to the charging roller 12, the developing roller 14, and the supply roller 15, respectively. The photoreceptor drum 11 also rotates, and in conjunction with this, the charging roller 12, the developing roller 14, and the supply roller 15 also rotate.

[0090] The charging roller 12 uniformly charges the surface of the photoreceptor drum 11. The print head 13 exposes the surface of the photoreceptor drum 11 to form an electrostatic latent image. Toner is supplied to the developing roller 14 by the supply roller 15, and a toner layer is formed on the surface of the developing roller 14 by the developing blade 16. The electrostatic latent image formed on the photoreceptor drum 11 is developed by the toner on the surface of the developing roller 14 to form a toner image. The toner image formed on the photoreceptor drum 11 is transferred to the medium P on the transfer belt 32 by a transfer voltage applied to the transfer roller 31.

[0091] In this way, the toner images of each color formed in each process unit 10K, 10C, 10M, and 10Y are sequentially transferred to the medium P and superimposed. The medium P on which the toner images of each color have been transferred is further transported by the transfer belt 32 and reaches the fixing device 120.

[0092] In the fixing device 120, the fixing member 121 is heated to the fixing temperature by a heater and rotated. The medium P transported to the fixing device 120 is heated and pressurized between the fixing member 121 and the pressure roller 122, and the toner image is fixed to the medium P.

[0093] The media P on which the toner image has been fixed is transported along the discharge transport path R2 by the discharge roller pair 131 of the media discharge unit 130 and discharged to the outside of the image forming apparatus 1 through the discharge port 132. The discharged media P is stacked on the stacker unit 135. This completes the printing operation on the media P.

[0094] <effect> Next, the operation of this embodiment 1 will be explained with reference to Figures 4, 5, 8(A), (B), and 9. As shown in Figure 4, in each process unit 10, the transfer residue toner remaining on the photoreceptor drum 11 after the transfer of the toner image is scraped off by the cleaning member 17. The scraped waste toner falls into the first transport path 41 and is transported in the +X direction by the first transport spiral 42.

[0095] As shown in Figure 5, the waste toner transported to the +X end of the first transport path 41 falls from the discharge port 44 of the first transport path 41 and enters the waste toner drop path 51 from the inlet 52.

[0096] As shown in Figure 8(A), when the lower end 83b of the oscillating portion 83 of the stirring member 80 is not in contact with the wire of the second conveying spiral 62, the flexible portion 82 is not flexible, and the upper end 83a of the oscillating portion 83 is in contact with the second inner wall portion 55b. The waste toner that enters the waste toner drop path 51 from the inlet portion 52 falls into the space A1 between the oscillating portion 83 and the fixed portion 81.

[0097] As shown in Figure 8(B), when the second conveying spiral 62 rotates, the lower end portion 83b of the oscillating portion 83 comes into contact with the wire of the second conveying spiral 62 and moves in the +Y direction, causing the flexible portion 82 to bend, the contact portions 87 and 88 of the sliding portions 85 and 86 to come into contact with the fixed portion 81, and the oscillating portion 83 oscillates with the contact portions 87 and 88 as pivot points.

[0098] As the oscillating portion 83 swings, the upper end portion 83a moves in the -Y direction and contacts the first inner wall portion 55a, and the lower end portion 83b of the oscillating portion 83 moves in the +Y direction and reaches the vicinity of the +Y end of the outlet portion 53.

[0099] The waste toner in space A1 (Figure 8(A)) is broken up by the oscillation of the oscillating unit 83 and falls into space A2 below space A1. In addition, waste toner that newly enters the waste toner drop path 51 from the inlet 52 falls into space B1 between the oscillating unit 83 and the second inner wall 55b.

[0100] As the second conveying spiral 62 rotates further, the contact between the lower end 83b of the oscillating portion 83 and the wire of the second conveying spiral 62 is released, and the bending portion 82 returns to its pre-deformation position due to the restoring force. As a result, the upper end 83a of the oscillating portion 83 moves in the +Y direction and contacts the second inner wall portion 55b, and the lower end 83b moves in the -Y direction.

[0101] The waste toner in space B1 is broken up by the oscillation of the oscillating unit 83 and falls into space B2 (Figure 8(A)) below space B1.

[0102] In this manner, the waste toner that enters the waste toner drop path 51 from the inlet 52 is broken down by the oscillation of the oscillating unit 83 as it falls, and enters the second transport path 61 from the outlet 53.

[0103] The waste toner that enters the second transport path 61 is transported in the +Y direction by the second transport spiral 62. The waste toner transported in the +Y direction within the second transport path 61 is collected in the waste toner collection container 68 (Figure 3) via the connecting pipe 66.

[0104] Furthermore, if the amount of waste toner contained in the waste toner collection container 68 exceeds a specified amount, the control unit will detect this using a sensor or the like and display a message on the display unit of the image forming apparatus 1. The user can remove the waste toner collection container 68 from the front (+Y direction) of the apparatus housing 100 and replace it with a new waste toner collection container 68.

[0105] As shown in Figure 9, just before the lower end 83b of the oscillating part 83 and the wire of the second conveying spiral 62 come into contact, it is desirable that the entire sides 85a and 86b of the sliding parts 85 and 86 of the stirring member 80 be in contact with the fixed part 81. This suppresses stress concentration in the sliding parts 85 and 86, prevents deformation of the sliding parts 85 and 86, and thereby stabilizes the posture of the oscillating part 83 (prevents collapse of posture).

[0106] <Effects of Embodiment 1> As described above, the waste toner transport unit 7 as a powder transport device of Embodiment 1 comprises a waste toner drop path 51 and an inner duct 55 as a powder drop path through which the waste toner as powder falls by its own weight; a second transport path 61 as a powder transport path connected to the lower part of the waste toner drop path 51 and extending in a direction intersecting the waste toner drop path 51; a second transport spiral 62 as a transport member provided in the second transport path 61 and transporting the waste toner along the second transport path 61 by rotating; and an agitation member 80 provided in the waste toner drop path 51 and having a swinging part 83 that swings within the waste toner drop path 51 by contact with the second transport spiral 62. The swinging part 83 of the agitation member 80 swings such that its upper end 83a and lower end 83b move in opposite directions to each other.

[0107] In this way, the stirring member 80 oscillates so that its upper end 83a and lower end 83b move in opposite directions to each other, thereby stirring the waste toner inside the waste toner drop path 51 (especially near the inlet 52 and the outlet 53).

[0108] In other words, in the waste toner drop path 51, where the action of movable parts such as the first transport spiral 42 or the second transport spiral 62 does not directly affect the waste toner, it is possible to prevent the accumulation and aggregation of waste toner.

[0109] Furthermore, since the stirring member 80 does not block the waste toner drop channel 51 while it is oscillating, it is possible to prevent waste toner from adhering to the inner surface of the powder drop channel (waste toner drop channel 51 and inner duct 55).

[0110] Furthermore, since the fixed portion 81 of the stirring member 80 is fixed to the inner wall portion (first inner wall portion 55a) on the upstream side of the conveying direction by the second conveying spiral 62 in the waste toner drop path 51, the oscillating portion 83 is oscillated in the +Y direction (downstream side of the conveying direction) relative to the fixed portion 81, allowing the waste toner in the waste toner drop path 51 to be efficiently stirred.

[0111] Furthermore, since the oscillating part 83 and the fixed part 81 of the stirring member 80 are spaced apart from each other in the transport direction (Y direction), the fixed part 81 can be fixed to the waste toner drop path 51 while the oscillating part 83 can be oscillated widely in the Y direction, allowing for efficient stirring of the waste toner in the waste toner drop path 51.

[0112] Furthermore, since the oscillating portion 83 of the stirring member 80 has contact portions 87 and 88 that abut against the fixed portion 81 and form the pivot point for the oscillating portion 83, the oscillating of the oscillating portion 83 moves the upper end portion 83a and the lower end portion 83b in opposite directions, allowing the waste toner to be efficiently stirred near the inlet portion 52 and near the outlet portion 53 in the waste toner drop path 51.

[0113] Furthermore, the stirring member 80 has a flexible portion 82 below the fixed portion 81 that can be deformed in the +Y direction (conveying direction) and the -Y direction (opposite direction to the conveying direction), and the oscillating portion 83 is connected to the flexible portion 82, so the oscillating portion 83 can be oscillated by utilizing the deflection of the flexible portion 82.

[0114] Furthermore, the oscillating portion 83 of the stirring member 80 is inclined such that its upper end 83a is positioned in the +Y direction (downstream in the conveying direction) relative to its lower end 83b when it is not in contact with the second conveying spiral 62. As a result, the lower end 83b moves in the +Y direction due to contact with the second conveying spiral 62, causing the upper end 83a to move in the -Y direction, thereby efficiently stirring the waste toner near the inlet 52 of the waste toner drop path 51.

[0115] Furthermore, when the lower end portion 83b of the oscillating portion 83 is biased in the +Y direction by contact with the second transport spiral 62, the lower end portion 83b moves to be positioned in the +Y direction (downstream in the transport direction) relative to the upper end portion 83a, thereby enabling efficient agitation of the waste toner near the outlet portion 53 of the waste toner drop path 51.

[0116] Furthermore, since the stirring member 80 is positioned such that the lower end portion 83b of the oscillating portion 83 is inside the range of movement of the second conveying spiral 62, the lower end portion 83b can be moved in the +Y and -Y directions by utilizing contact with the wire of the second conveying spiral 62.

[0117] Furthermore, when the oscillating part 83 is not in contact with the second transport spiral 62, the upper end portion 83a of the oscillating part 83 contacts the second inner wall portion 55b (the inner wall portion on the downstream side in the transport direction), and when the oscillating part 83 is in contact with the second transport spiral 62, the upper end portion 83a of the oscillating part 83 contacts the first inner wall portion 55a (the inner wall portion on the upstream side in the transport direction). As a result, the waste toner can be efficiently agitated near the inlet portion 52 of the waste toner drop path 51.

[0118] Furthermore, since the stirring member 80 has sliding parts 85 and 86 at at least one end in the width direction of the oscillating part 83 that contact the inner wall portion (inner wall portion 55c, 55d) of the waste toner drop path 51, it is possible to prevent waste toner from adhering to the inner wall portion 55c, 55d.

[0119] Furthermore, since the stirring member 80 is made of resin, it is possible to prevent the accumulation of waste toner in the waste toner drop path 51 while keeping manufacturing costs down.

[0120] Furthermore, the image forming apparatus 1 of the first embodiment includes a process unit 10 as an image forming unit and a waste toner transport unit 7 (powder transport device) that transports waste toner (powder) generated by the process unit 10. Therefore, malfunctions of the image forming apparatus 1 caused by waste toner clogging and the like can be prevented.

[0121] Variation 1. Figure 10 is a perspective view showing a modified stirring member 80A of Embodiment 1. In the stirring member 80 of Embodiment 1, sliding parts 85 and 86 were formed at both ends in the width direction of the oscillating part 83 (see Figures 7(A) and (B)). In contrast, in the modified stirring member 80A, as shown in Figure 10, a sliding part 85 is formed at one end in the width direction of the oscillating part 83.

[0122] More specifically, a sliding portion 85 is formed on side 83c of the oscillating portion 83 (i.e., the side on the same side as the connecting portion 84). The shape of the sliding portion 85 is as described in Embodiment 1. In addition, a contact portion 87 is formed on the sliding portion 85, which serves as the pivot point for the oscillating motion of the oscillating portion 83.

[0123] Even when using the modified stirring member 80A, the oscillating part 83 can be oscillated in the same way as the stirring member 80 of Embodiment 1, and the waste toner in the waste toner drop path 51 can be efficiently diffused.

[0124] Embodiment 2. Figure 11 is a partially cutaway perspective view showing the waste toner drop path 51 and its surroundings in the waste toner transport section 7A as a powder transport device of Embodiment 2. Figure 12 is a cross-sectional view showing the waste toner drop path 51 and its surroundings. The waste toner transport section 7A of Embodiment 2 differs from the waste toner transport section 7 of Embodiment 1 in the configuration of the stirring member 90.

[0125] As shown in Figures 11 and 12, the waste toner transport section 7A has an agitation member 90 inside the waste toner drop path 51. The agitation member 90 is provided such that its upper end (the upper ends 94a and 95a of the oscillating arms 94 and 95, described later) reaches the discharge port 44 of the first transport path 41, and its lower end (the lower end 93c of the oscillating piece 93, described later) reaches inside the range of movement of the second transport spiral 62 in the second transport path 61.

[0126] Figure 13 is a perspective view showing the stirring member 90. Similar to the stirring member 80 of Embodiment 1, the stirring member 90 is formed by bending a film made of a flexible resin such as PET. The stirring member 90 has a fixed part 91, a flexible part 92, a swinging piece 93, and swinging arms 94 and 95. The swinging piece 93 and the swinging arms 94 and 95 constitute a swinging part that swings relative to the fixed part 91.

[0127] The fixing portion 91 is fixed to the inner duct 55. The fixing portion 91 is a long strip in the Z direction and has a width in the X direction. The edge forming the -X end of the fixing portion 91 is called edge 91a, and the edge forming the +X end of the fixing portion 91 is called edge 91b. Here, edges 91a and 91b extend parallel to each other. As will be described later, edge 91b of the fixing portion 91 is fixed to the inner surface of the inner duct 55.

[0128] At the lower ends of sides 91a and 91b of the fixed portion 91, notches C1 and C2 are formed opposite each other in the X direction, and a flexible portion 92 is formed between these notches C1 and C2. The oscillating piece 93 is formed below the fixed portion 91 (in the -Z direction) via the flexible portion 92. The oscillating piece 93 is not fixed to the inner duct 55 and can bend around the flexible portion 92. Note that in Figure 13, the notch C2 (Figure 12) is hidden.

[0129] The edge forming the -X end of the oscillating piece 93 is referred to as edge 93a, and the edge forming the +X end of the oscillating piece 93 is referred to as edge 93b. Edge 93b of the oscillating piece 93 is formed slightly inward in the X direction (i.e., towards edge 91a) than edge 91b of the fixed part 91, and extends in a straight line. Also, edge 93a, which extends in a straight line on the opposite side of edge 93b of the oscillating piece 93, is formed at approximately the same position in the X direction as edge 91a of the fixed part 91, but edge 93a may be formed slightly inward (i.e., towards edge 91b) than edge 91a.

[0130] In other words, when attaching the fixing part 91 of the stirring member 90 to the inner duct 55, the side 91b is aligned with the fourth inner wall portion 55d of the inner duct 55 (the inner wall portion downstream in the toner transport direction by the first transport spiral 42). However, in order to make it easier to attach the fixing part 91 to the inner duct 55, the space between the third inner wall portion 55c and the side 91a should be wider than the space between the fourth inner wall portion 55d and the side 91b, as shown in Figure 12.

[0131] The oscillating arms 94 and 95 extend in the +Y direction from the sides 93a and 93b of the oscillating piece 93, respectively. The sides 93a and 93b of the oscillating piece 93 correspond to the bases of the oscillating arms 94 and 95. The oscillating arms 94 and 95 face each other in the X direction, and a space for toner to pass is formed between them.

[0132] The upper ends 94a and 95a of the swinging arms 94 and 95 are formed to reach the inlet 52 (Figure 11) of the waste toner drop path 51 and to extend further into the discharge port 44 of the first transport path 41.

[0133] The rocking arm 94 also has sides 94b and 94c oriented in the +Y direction. Side 94b is parallel to side 93a of the rocking piece 93. Side 94c is formed continuously with side 94b in the -Z direction (downward) and is inclined to approach side 93a as it extends downward. Similarly, the rocking arm 95 has sides 95b and 95c. The direction of extension of sides 95b and 95c is the same as that of sides 94b and 94c of the rocking arm 94.

[0134] The lower end portion 93c of the oscillating piece 93 is positioned to contact the second conveying spiral 62 in the second conveying path 61 (Figure 11). The oscillating piece 93 has notches C3 and C4 below the oscillating arms 94 and 95 and on both sides in the X direction, but these are not necessarily required.

[0135] The oscillating section, consisting of the oscillating piece 93 and the oscillating arms 94 and 95, oscillates around the flexible section 92. The flexible section 92 is preferably located at the center in the Z direction of the waste toner drop path 51, but it is acceptable for it to be located between the inlet section 52 and the outlet section 53.

[0136] It is preferable that the stirring member 90 is formed entirely by folding a single film. In this case, the oscillating arms 94 and 95 are formed by folding the film along the sides 93a and 93b of the oscillating piece 93. However, the stirring member 90 is not limited to being formed by folding a single film, but may be made by combining multiple films.

[0137] As shown in Figure 12, the side 91b of the fixing portion 91 of the stirring member 90 is fixed to the fourth inner wall portion 55d of the inner duct 55. On the other hand, a gap is provided between the side 91a of the fixing portion 91 and the third inner wall portion 55c of the inner duct 55. In other words, the fixing portion 91 of the stirring member 90 is fixed to the inner duct 55 at one end in the width direction, which is the X direction.

[0138] Figures 14(A) and (B) are cross-sectional views illustrating the operation of the stirring member 90. In the state shown in Figure 14(A), the lower end portion 93c of the oscillating piece 93 of the stirring member 90 is inside the range of movement of the second conveying spiral 62, but is not biased by the wire of the second conveying spiral 62.

[0139] In this state, the flexible portion 92 of the stirring member 90 is not bent, and the oscillating piece 93 extends linearly in the -Z direction from the fixed portion 91. At this time, the upper ends 94a and 95a of the oscillating arms 94 and 95 (the oscillating arm 95 is hidden in Figures 14(A) and (B)) are located inside the discharge port 44 of the waste toner discharge section 40 and are in contact with the inner surface of the discharge port 44 on the +Y side (left side in the figure).

[0140] As shown in Figure 14(B), when the second conveying spiral 62 rotates and the lower end portion 93c of the oscillating piece 93 is biased by the wire of the second conveying spiral 62 and moves in the +Y direction, the oscillating piece 93 oscillates around the flexible portion 92.

[0141] As the oscillating piece 93 oscillates, the oscillating arms 94 and 95 provided on the oscillating piece 93 also oscillate. As a result, the upper ends 94a and 95a of the oscillating arms 94 and 95 move in the -Y direction and come into contact with the inner surface of the -Y side (right side in the figure) of the discharge port 44.

[0142] In this manner, the oscillating section of the stirring member 90, consisting of the oscillating piece 93 and the oscillating arms 94 and 95, oscillates such that its upper ends 94a and 95a and lower end 93c move in opposite directions (-Y direction and +Y direction). Since the upper ends 94a and 95a of the oscillating arms 94 and 95 are inserted into the discharge port 44, the waste toner can be efficiently stirred, especially in the vicinity of the discharge port 44.

[0143] Furthermore, since the oscillating arms 94 and 95 are positioned with a gap between them and the inner surface of the inner duct 55 (more specifically, the inner wall portions 55c and 55d), the waste toner can be efficiently agitated near the inner surface of the inner duct 55, preventing the waste toner from adhering to and accumulating on the inner surface of the inner duct 55.

[0144] Furthermore, since the oscillating arms 94 and 95 do not come into contact with the inner surface of the inner duct 55, twisting of the oscillating arms 94 and 95 due to friction with the inner surface of the inner duct 55 can be prevented, and the stirring effect can be maintained.

[0145] Furthermore, as shown in Figure 13, since the swinging arms 94 and 95 each have sides 94b, 95b and sides 94c, 95c respectively, interference between the swinging arms 94 and 95 and the waste toner drop path 51 and the inner duct 55 can be prevented when the swinging arms 94 and 95 swing as shown in Figures 14(A) and (B).

[0146] Furthermore, as shown in Figure 12, the oscillating arm 95 is located downstream and the oscillating arm 94 is located upstream with respect to the transport direction (+X direction) of the waste toner by the first transport spiral 42 of the waste toner discharge section 40. Therefore, even if the waste toner discharged from the discharge port 44 is slightly biased towards the +X direction (transport direction), the stirring action of the oscillating arm 95 prevents the waste toner from adhering to and accumulating on the inner surface of the inner duct 55.

[0147] Next, the connection operation between the first transport path 41 of the waste toner discharge unit 40 and the waste toner drop path 51 will be described. The first transport path 41 is part of the process unit 10, while the waste toner drop path 51 is part of the device housing 100 (Figure 1) of the image forming apparatus 1. Therefore, when the process unit 10 is attached to the device housing 100, the first transport path 41 and the waste toner drop path 51 are connected, and when the process unit 10 is removed from the device housing 100, the first transport path 41 and the waste toner drop path 51 are separated.

[0148] Figure 15(A) shows the waste toner transport section 7A before the process unit 10 is attached to the device housing 100. As shown in Figure 15(A), in the state before the process unit 10 is attached to the device housing 100, the first transport path 41 is not connected to the waste toner drop path 51, and the inlet 52 of the waste toner drop path 51 is open.

[0149] Figure 15(B) shows the waste toner transport section 7A with the process unit 10 attached to the device housing 100. As shown in Figure 15(B), when the process unit 10 is attached to the device housing 100, the first transport path 41 and the waste toner drop path 51 are connected, and the discharge port 44 and the inlet 52 of the waste toner drop path 51 face each other. At this time, the area around the discharge port 44 of the waste toner discharge section 40 presses against the sponge 56 on the inner duct 55 inside the waste toner drop path 51, causing the inner duct 55 to move downward while compressing the biasing member 58.

[0150] Figure 16(A) shows the vicinity of the upper end of the waste toner drop path 51 before the first transport path 41 and the waste toner drop path 51 are connected. As shown in Figure 16(A), in the state before the first transport path 41 and the waste toner drop path 51 are connected, the flange portion 55e of the inner duct 55 is biased upward (+Z direction) by the biasing member 58, causing the inner duct 55 to protrude upward from the waste toner drop path 51. The sponge 56 provided on the flange portion 55e of the inner duct 55 has a thickness H1 in the Z direction (vertical direction).

[0151] Figure 16(B) shows the vicinity of the upper end of the waste toner drop path 51 in a state where the first transport path 41 and the waste toner drop path 51 are connected. Note that in Figure 16(B), the waste toner discharge section 40 (first transport path 41 and first transport spiral 42) is omitted. The sponge 56 on the inner duct 55 is pressed against the area around the discharge port 44 of the waste toner discharge section 40, and its thickness H2(

[0152] In the example shown in Figure 16(B), the first portion 56a (i.e., the inner circumference) of the sponge 56 surrounding the entrance portion 52 is compressed to a thickness of H2, while the second portion 56b (outer circumference) on its outer side remains at a thickness of H1. However, in Embodiment 2, the entire sponge 56 may be compressed to a thickness of H2.

[0153] When the sponge 56 is compressed, the upper ends 94a and 95a of the oscillating arms 94 and 95 of the stirring member 90 are positioned higher than the upper end of the sponge 56 (more specifically, the upper end of the first portion 56a). In other words, the upper ends 94a and 95a of the oscillating arms 94 and 95 protrude upward from the sponge 56 by a distance D (>0). Therefore, the upper ends 94a and 95a of the oscillating arms 94 and 95 can enter the discharge port 44 (Figure 15(B)).

[0154] In contrast, as shown in Figure 16(A), when the sponge 56 is not compressed, the upper ends 94a and 95a of the oscillating arms 94 and 95 of the stirring member 90 are lower than the upper surface of the sponge 56. That is, the oscillating arms 94 and 95 of the stirring member 90 do not protrude above the sponge 56.

[0155] The effect of the positional relationship between the stirring member 90 and the sponge 56 will now be explained. When the process unit 10 is removed from the apparatus housing 100 (Figure 1), the inner duct 55 moves upward due to the biasing force of the biasing member 58, as shown in Figure 15(A).

[0156] ​As the inner duct 55 moves upward, the stirring member 90 fixed to the inner duct 55 also moves upward, and the oscillating piece 93 moves out of the range of motion of the second conveying spiral 62. At this time, the contact between the oscillating piece 93 of the stirring member 90 and the second conveying spiral 62 is eliminated, so the oscillating arms 94 and 95 may oscillate due to the elastic restoring force of the stirring member 90.

[0157] In this case, if the upper ends 94a and 95a of the oscillating arms 94 and 95 protrude above the upper surface of the sponge 56, the oscillating motion of the oscillating arms 94 and 95 may cause waste toner attached to the upper ends 94a and 95a to scatter into the surrounding area.

[0158] However, in Embodiment 2, as shown in Figure 16(A), when the sponge 56 is not compressed, the upper ends 94a and 95a of the oscillating arms 94 and 95 are lower than the upper surface of the sponge 56. Therefore, the scattering of waste toner caused by the oscillating arms 94 and 95 is prevented by the sponge 56.

[0159] Here, we have described an example in which an inner duct 55 (movable duct) is provided inside the waste toner drop path 51, but it is not necessary to provide an inner duct 55. That is, a sponge 56 is provided on the waste toner drop path 51, and when the first transport path 41 and the waste toner drop path 51 are connected, the upper ends 94a and 95a of the swinging arms 94 and 95 are positioned above the upper ends of the sponge 56 (more specifically, the upper ends of the first portion 56a), and when the first transport path 41 and the waste toner drop path 51 are separated, the upper ends 94a and 95a of the swinging arms 94 and 95 are positioned below the upper ends of the sponge 56.

[0160] <Effects of Embodiment 2> As described above, in the waste toner transport section 7A of Embodiment 2, a sponge (elastic member) 56 is provided on the waste toner drop path 51 so as to surround the inlet 52. When the first transport path 41 and the waste toner drop path 51 are connected, the upper ends 94a and 95a of the oscillating arms 94 and 95 of the stirring member 90 are located above the upper ends of the sponge 56. When the first transport path 41 and the waste toner drop path 51 are separated, the upper ends 94a and 95a of the oscillating arms 94 and 95 of the stirring member 90 are located below the upper ends of the sponge 56.

[0161] With this configuration, when the first transport path 41 and the waste toner drop path 51 are connected, the upper ends 94a and 95a of the oscillating arms 94 and 95 of the stirring member 90 can stir the waste toner in the discharge port 44. Also, when the first transport path 41 and the waste toner drop path 51 are separated, the sponge 56 can prevent the scattering of waste toner due to the oscillating of the oscillating arms 94 and 95.

[0162] Furthermore, when the first transport path 41 and the waste toner drop path 51 are connected, the sponge 56 is compressed by the waste toner discharge section 40, and when the first transport path 41 and the waste toner drop path 51 are separated, the compression of the sponge 56 is released. This prevents waste toner from leaking from between the first transport path 41 and the waste toner drop path 51.

[0163] Furthermore, when the first transport path 41 and the waste toner drop path 51 are separated, the oscillating part (oscillating piece 93 and oscillating arms 94, 95) of the agitator 90 moves out of the range of motion of the second transport spiral 62. Therefore, when separating the waste toner discharge section 40 from the waste toner transport section 7A, the oscillating piece 93 of the agitator 90 may deform as if being repelled. However, as described above, since the upper ends 94a, 95a of the oscillating arms 94, 95 are located below the upper end of the sponge 56, the scattering of waste toner can be prevented.

[0164] Furthermore, since the oscillating arms 94 and 95 that constitute the oscillating part of the stirring member 90 are positioned with a gap between them and the inner surface of the inner duct 55, it is possible to prevent waste toner from adhering to and accumulating on the inner surface of the inner duct 55. In addition, since the oscillating arms 94 and 95 do not come into contact with the inner surface of the inner duct 55, deformation of the oscillating arms 94 and 95 due to friction is prevented, and the stirring capacity can be maintained.

[0165] Furthermore, since the stirring member 90 has a swinging arm 95 on the downstream side in the direction of waste toner transport (+X direction) by the first transport spiral 42, and a swinging arm 94 on the upstream side, even if waste toner is discharged from the discharge port 44 with an imbalance in that transport direction, the swinging arm 95 can prevent waste toner from adhering to the inner surface of the inner duct 55.

[0166] Although embodiments 1 and 2 and their variations have been described above, this disclosure is not limited to embodiments 1 and 2 and their variations described above, and various modifications or alterations are possible. For example, embodiments 1 and 2 and their variations described above may be applied to the transport of powders other than waste toner (e.g., unused toner).

[0167] This disclosure can be used in image forming apparatuses (e.g., photocopiers, facsimile machines, printers, multifunction devices, etc.) that use electrophotography to form images on a medium.

[0168] The various aspects of this disclosure are summarized below as an appendix. (Note 1) A powder drop path through which the powder falls by its own weight, A powder transport path is connected to the lower part of the powder drop path and extends in a direction intersecting the powder drop path, A conveying member provided in the powder conveying path, which rotates to convey the powder along the powder conveying path in a predetermined conveying direction, A stirring member provided in the powder drop path and having a rocking part that rocks within the powder drop path by contact with the conveying member, Equipped with, The oscillating portion of the stirring member oscillates such that its upper end and lower end move in opposite directions. A powder conveying device characterized by the following features. (Note 2) The stirring member has a fixing portion fixed to the inner surface on the upstream side in the conveying direction of the powder drop path. The powder conveying apparatus described in Appendix 1, characterized by the features described herein. (Note 3) The oscillating portion and the fixed portion of the stirring member are spaced apart from each other in the conveying direction. The powder conveying apparatus described in Appendix 2, characterized by the features described herein. (Note 4) The swinging part has a contact portion that abuts against the fixed portion and forms the pivot point for the swinging of the swinging part. A powder conveying device as described in Appendix 2 or 3, characterized by the features described herein. (Note 5) The stirring member has a flexible portion below the fixed portion that can be deformed in the conveying direction and the opposite direction, The oscillating part is connected to the bending part. A powder conveying device as described in any one of the appendices 2 to 4, characterized by the above. (Note 6) When the oscillating portion is not in contact with the conveying member, the upper end of the oscillating portion is inclined so that it is located downstream in the conveying direction relative to the lower end. A powder conveying apparatus as described in any one of the appendices 1 to 5, characterized by the above. (Note 7) When the lower end of the oscillating part comes into contact with the conveying member and is biased by the rotation of the conveying member, the lower end of the oscillating part moves downstream in the conveying direction relative to the upper end. The powder conveying apparatus described in Appendix 6, characterized by the features described herein. (Note 8) The stirring member is positioned such that the lower end of the oscillating part is inside the range of movement of the conveying member. A powder conveying apparatus as described in any one of the appendices 1 to 7, characterized by the above. (Note 9) When the oscillating part is not in contact with the conveying member, the upper end of the oscillating part contacts the inner surface of the powder drop path on the downstream side in the conveying direction. A powder conveying apparatus as described in any one of the appendices 1 to 8, characterized by the above. (Note 10) With the oscillating part in contact with the conveying member, the upper end of the oscillating part contacts the inner surface of the powder drop path on the upstream side in the conveying direction. A powder conveying apparatus as described in any one of the appendices 1 to 9, characterized by the above. (Note 11) The oscillating portion has a sliding portion at at least one end in the width direction of the oscillating portion that contacts the inner surface of the powder drop path. A powder conveying apparatus as described in any one of the appendices 1 to 10, characterized by the above. (Note 12) When the oscillating part comes into contact with the conveying member, the upper end of the oscillating part moves in the opposite direction to the conveying direction, and the lower end of the oscillating part moves in the conveying direction. A powder conveying apparatus as described in any one of the appendices 1 to 11, characterized by the features described herein. (Note 13) A powder discharge channel is provided which has an outlet facing the inlet of the powder drop channel, and which drops the powder from the outlet to the inlet. An elastic member is provided between the powder drop channel and the powder discharge channel so as to surround the inlet of the powder drop channel. When the powder discharge passage and the powder drop passage are connected, the upper end of the swinging part protrudes above the upper end of the elastic member and enters the discharge port. When the powder discharge path and the powder drop path are separated, the upper end of the oscillating part is located below the upper end of the elastic member. A powder conveying apparatus as described in any one of the appendices 1 to 12, characterized by the features described herein. (Note 14) When the powder discharge channel and the powder drop channel are connected, the elastic member is compressed between the powder drop channel and the powder discharge channel. When the powder discharge channel and the powder drop channel are separated, the compression of the elastic member by the powder drop channel and the powder discharge channel is released. The powder conveying apparatus described in Appendix 13, characterized by the features described herein. (Note 15) When the powder discharge path and the powder drop path are separated, the oscillating part of the stirring member moves out of the range of movement of the conveying member. A powder conveying device as described in Appendix 13 or 14, characterized by the features described herein. (Note 16) The oscillating portion of the stirring member has a pair of arms, A space for powder to pass through is formed between the pair of arms. A powder conveying apparatus as described in any one of the appendices 13 to 15, characterized by the above. (Note 17) Both of the pair of arms of the stirring member are positioned with a gap between them and the inner surface of the powder drop path. The powder conveying apparatus described in Appendix 16, characterized by the features described herein. (Note 18) The powder discharge passage has a conveying mechanism for transporting the powder to the discharge port. The pair of arms are positioned on the downstream and upstream sides, respectively, in the direction of transport by the transport mechanism. A powder conveying device as described in Appendix 16 or 17, characterized by the features described herein. (Note 19) The stirring member is made of resin. A powder conveying apparatus as described in any one of the appendices 1 to 18, characterized by the above. (Note 20) An image forming unit that forms an image using a developer, A powder conveying device described in any one of the appendices 1 to 19 for conveying the developer as a powder, An image forming apparatus characterized by comprising the following: [Explanation of Symbols]

[0169] 1 Image forming apparatus, 7,7A Waste toner transport section (powder transport device), 10,10K,10C,10M,10Y Process unit (image forming unit), 11 Photoreceptor drum (image carrier), 12 Charging roller (charging member), 13 Print head (exposure device), 14 Developer roller (developer carrier), 15 Supply roller (supply member), 16 Developer blade (layer restricting member), 17 Cleaning member, 20,20K,20C,20M,20Y Toner cartridge, 30 Transfer unit, 31 Transfer roller (transfer member), 32 Transfer belt (transfer body), 40 Waste toner discharge section (discharge unit), 41 First transport path (powder discharge path), 42 First transport spiral (transport mechanism, first transport member), 50 Waste toner transport unit, 51 52 Waste toner drop path (powder drop path), 52 Inlet section, 53 Outlet section, 55 Inner duct (powder drop path), 55a, 55b, 55c, 55d Inner wall section, 56 Sponge (elastic member, first elastic member), 56a First section, 56b Second section, 57 Sponge (second elastic member), 58 Biasing member, 60 Waste toner recovery unit, 61 Second transport path (powder transport path), 62 Second transport spiral (transport member, second transport member), 65 Motor, 68 Waste toner recovery container (powder container), 80, 80A, 90 Agitation member, 81, 91 Fixed section, 82, 92 Flexible section, 83 Oscillating section, 83a Upper end section, 83b Lower end section, 84 Connecting section, 85,86 Sliding part, 87,88 Contact part (pivot part), 89 Double-sided tape, 93 Swiveling piece (swinging part), 93c Lower end, 94,95 Swiveling arm (arm part, swinging part), 94a,95a Upper end, 100 Device housing, 101 Front cover, 102 Top cover, 105 Unit frame, 110 Media supply unit, 120 Fixing device, 130 Media discharge unit.

Claims

1. A powder drop path through which the powder falls by its own weight, A powder transport path is connected to the lower part of the powder drop path and extends in a direction intersecting the powder drop path, A conveying member provided in the powder conveying path, which rotates to convey the powder along the powder conveying path in a predetermined conveying direction, A stirring member provided in the powder drop path and having a rocking part that rocks within the powder drop path by contact with the conveying member, Equipped with, The oscillating portion of the stirring member oscillates such that its upper end and lower end move in opposite directions. A powder conveying device characterized by the following features.

2. The stirring member has a fixing portion fixed to the inner surface on the upstream side in the conveying direction of the powder drop path. The powder conveying apparatus according to feature 1.

3. The oscillating portion and the fixed portion of the stirring member are spaced apart from each other in the conveying direction. The powder conveying apparatus according to feature 2.

4. The swinging part has a contact portion that abuts against the fixed portion and forms the pivot point for the swinging of the swinging part. The powder conveying apparatus according to feature 2.

5. The stirring member has a flexible portion below the fixed portion that can be deformed in the conveying direction and the opposite direction, The oscillating part is connected to the bending part. The powder conveying apparatus according to feature 2.

6. When the oscillating portion is not in contact with the conveying member, the upper end of the oscillating portion is inclined so that it is located downstream in the conveying direction relative to the lower end. The powder conveying apparatus according to feature 1.

7. When the lower end of the oscillating part comes into contact with the conveying member and is biased by the rotation of the conveying member, the lower end of the oscillating part moves downstream in the conveying direction relative to the upper end. The powder conveying apparatus according to feature 6.

8. The stirring member is positioned such that the lower end of the oscillating part is inside the range of movement of the conveying member. The powder conveying apparatus according to feature 1.

9. When the oscillating part is not in contact with the conveying member, the upper end of the oscillating part contacts the inner surface of the powder drop path on the downstream side in the conveying direction. The powder conveying apparatus according to feature 1.

10. With the oscillating part in contact with the conveying member, the upper end of the oscillating part contacts the inner surface of the powder drop path on the upstream side in the conveying direction. The powder conveying apparatus according to feature 1.

11. The oscillating portion has a sliding portion at at least one end in the width direction of the oscillating portion that contacts the inner surface of the powder drop path. The powder conveying apparatus according to feature 1.

12. When the oscillating part comes into contact with the conveying member, the upper end of the oscillating part moves in the opposite direction to the conveying direction, and the lower end of the oscillating part moves in the conveying direction. The powder conveying apparatus according to feature 1.

13. A powder discharge channel is provided which has an outlet facing the inlet of the powder drop channel, and which drops the powder from the outlet to the inlet. An elastic member is provided between the powder drop channel and the powder discharge channel so as to surround the inlet of the powder drop channel. When the powder discharge passage and the powder drop passage are connected, the upper end of the swinging part protrudes above the upper end of the elastic member and enters the discharge port. When the powder discharge path and the powder drop path are separated, the upper end of the oscillating part is located below the upper end of the elastic member. The powder conveying apparatus according to feature 1.

14. When the powder discharge channel and the powder drop channel are connected, the elastic member is compressed between the powder drop channel and the powder discharge channel. When the powder discharge channel and the powder drop channel are separated, the compression of the elastic member by the powder drop channel and the powder discharge channel is released. The powder conveying apparatus according to feature 13.

15. When the powder discharge path and the powder drop path are separated, the oscillating part of the stirring member moves out of the range of movement of the conveying member. The powder conveying apparatus according to feature 13.

16. The oscillating portion of the stirring member has a pair of arms, A space for powder to pass through is formed between the pair of arms. The powder conveying apparatus according to feature 13.

17. Both of the pair of arms of the stirring member are positioned with a gap between them and the inner surface of the powder drop path. The powder conveying apparatus according to feature 16.

18. The powder discharge passage has a conveying mechanism for transporting the powder to the discharge port. The pair of arms are positioned on the downstream and upstream sides, respectively, in the direction of transport by the transport mechanism. The powder conveying apparatus according to feature 16.

19. The stirring member is made of resin. The powder conveying apparatus according to feature 1.

20. An image forming unit that forms an image using a developer, A powder conveying device according to any one of claims 1 to 19 for conveying the developer as a powder, An image forming apparatus characterized by comprising the following:

Images