Toner conveying device and image forming apparatus

Abstract

A toner conveying device includes: a first conveying portion that conveys toner, the first conveying portion having a first screw that is rotatable and a first conveying passage forming member that forms a first conveying space around the first screw; a second conveying portion that conveys toner from the first conveying portion upward, the second conveying portion having a second screw that is rotatable and a second conveying passage forming member that forms a second conveying space around the second screw and includes a connection portion; and a protruding portion that protrudes from a region of the first conveying passage forming member that is above a first rotation axis toward a rotation axis line of the first rotation axis, the protruding portion being disposed between a downstream end of a first blade portion that is located most downstream in a toner conveying direction of the first screw and a connection port in a direction of the rotation axis line, the protruding portion overlapping the first blade portion when viewed in the direction of the rotation axis line of the first rotation axis.

Description

[0001] This application is a divisional application of the invention patent application entitled "Toner Delivery Device and Imaging Device", with a national application date of November 12, 2020 and national application number of 202011263381.4. Technical Field

[0002] The present invention relates to a toner delivery device for delivering toner, and an electrophotographic imaging device equipped with the toner delivery device. Background Technology

[0003] Conventional electrophotographic imaging devices such as printers, copiers, and fax machines consist of three components: a toner holding unit that pre-stores toner; a toner delivery unit that delivers the toner; and an imaging section located downstream of the toner delivery unit. As a structure for delivering toner, there exists a configuration in which a helical screw with a central rotating shaft is arranged in a delivery channel, and the toner is delivered from upstream to downstream of the delivery channel by rotating the helical screw.

[0004] Japanese Patent Application Publication No. 2014-157350 discloses a structure for dripping and conveying toner from a toner supply port to a developing apparatus, wherein the toner is conveyed via a toner delivery channel from a toner bottle arranged vertically above a toner receiving unit. (The last sentence appears to be incomplete and possibly refers to a different document.) Figure 9 and 11 In the configuration shown, multiple screws arranged in a toner delivery channel consisting of multiple interconnected delivery channels change the delivery direction and height of the toner in order to deliver the toner to the desired toner supply port.

[0005] For example, in Japanese patent application publication No. 2014-157350 Figure 10 In the illustrated configuration, two screws are arranged to intersect in a virtual direction, thereby conveying the toner from upstream to downstream. At the conveying section through which the toner passes, the downstream edge of the upstream screw and the upstream edge of the downstream screw are arranged to intersect in a vertical direction. When the toner conveyed by the upstream screw reaches the downstream edge of the upstream screw, it is guided to the downstream screw by gravity. The toner is then further conveyed downstream via the downstream screw.

[0006] Japanese Patent Application Publication No. 2012-230358 also discloses a structure in which two screws are arranged to cross in the vertical direction, thereby conveying the toner by transferring it from the upstream screw to the downstream screw. As shown in Figure 8 of Japanese Patent Application Publication No. 2012-230358, the upstream and downstream screws cross in the vertical direction, causing the toner to be conveyed downstream in the conveying direction. Summary of the Invention

[0007] In these existing technologies, at the conveying section where the toner is transferred from the upstream screw to the downstream screw, the toner is subjected to gravity in addition to the conveying force of the screw. Through the combined force of gravity and the conveying force of the screw, the toner is pushed out of the conveying channel with the upstream screw and flows into the conveying channel with the downstream screw (the downstream side of the toner conveying channel). Therefore, there is a need to improve the toner conveying efficiency on the downstream side of the toner conveying channel.

[0008] In view of the foregoing, one object of the present invention is to improve the toner delivery efficiency on the downstream side of the toner delivery device.

[0009] To achieve the above objectives, the toner delivery device of the present invention for delivering toner for imaging includes:

[0010] A first conveying section configured to convey toner has a first screw and a first conveying channel forming component. The first screw includes a first rotating shaft and a first blade portion and is rotatable. The first conveying channel forming component forms a first conveying space in which the first screw is disposed.

[0011] The second conveying section is configured to convey the toner conveyed by the first conveying section upwards. The second conveying section has a second screw and a second conveying channel forming member. The second screw includes a second rotating shaft and a second blade portion and is rotatable. The second conveying channel forming member forms a second conveying space in which the second screw is disposed. The second conveying channel forming member has a connection port that is connected to the first conveying channel forming member.

[0012] The protruding portion protrudes from the region of the first conveying channel forming component above the first rotating shaft toward the rotation axis of the first rotating shaft. The protruding portion is arranged in the direction of the rotation axis between the downstream end of the first blade portion at the downstreammost point in the toner conveying direction of the first screw and the connection port. When viewed along the rotation axis of the first rotating shaft, the protruding portion overlaps with the first blade portion.

[0013] According to the present invention, the toner delivery efficiency on the downstream side of the toner delivery device can be improved.

[0014] Other features of the invention will become apparent from the following description of exemplary embodiments with reference to the accompanying drawings. Attached Figure Description

[0015] Figure 1 This is a perspective view of a toner delivery device according to Embodiment 1 of the present invention;

[0016] Figures 2A to 2C This is a cross-sectional view of the toner delivery device according to Embodiment 1 of the present invention;

[0017] Figure 3 It is a graph illustrating the toner delivery properties according to Embodiment 1 of the present invention;

[0018] Figure 4 This is a schematic cross-sectional view of an imaging device according to Embodiment 1 of the present invention;

[0019] Figures 5A to 5C This is a cross-sectional view of the toner delivery device according to Embodiment 2 of the present invention;

[0020] Figure 6 This is a cross-sectional view of the toner delivery device according to Embodiment 3 of the present invention;

[0021] Figure 7 This is an explanatory diagram of a toner delivery device according to Embodiment 4 of the present invention;

[0022] Figure 8A and Figure 8B This is a perspective view of a toner delivery device according to Embodiment 4 of the present invention;

[0023] Figure 9 This is a schematic cross-sectional view of an imaging device according to Embodiment 4 of the present invention;

[0024] Figure 10 This is an explanatory diagram of a toner delivery device according to Embodiment 5 of the present invention;

[0025] Figure 11 This is a perspective view of a toner delivery device according to Embodiment 6 of the present invention;

[0026] Figures 12A to 12C This is an explanatory diagram of a toner delivery device according to Embodiment 6 of the present invention;

[0027] Figure 13 This is a schematic cross-sectional view of an imaging apparatus according to an embodiment of the present invention;

[0028] Figure 14 This is a schematic cross-sectional view of a toner delivery device according to Embodiment 7 of the present invention; and

[0029] Figures 15A to 15CThis is a schematic diagram illustrating a construction example of an anti-backflow rib (protruding portion) according to an embodiment of the present invention. Detailed Implementation

[0030] In the following description, various embodiments (examples) of the invention will be described with reference to the accompanying drawings. However, the dimensions, materials, shapes, and relative arrangements of the components described in the embodiments can be appropriately varied depending on the construction of the device to which the invention is applied, various conditions, etc. Therefore, the dimensions, materials, shapes, and relative arrangements of the components described in the various embodiments are not intended to limit the scope of the invention to the following embodiments.

[0031] Example 1

[0032] Reference Figure 4 An imaging apparatus 1 according to embodiment 1 of the present invention is described. Figure 4 It is a schematic cross-sectional view showing the overall structure of the imaging device 1, and is a cross-sectional view of the imaging device 1 viewed from the front side. Figure 4 This describes the configuration of the imaging device 1 in its normal installation state, where the imaging device 1 is arranged on a horizontal mounting surface. Figure 4 The left and right directions in the text correspond to the horizontal direction. Figure 4 The up and down directions in the diagram correspond to the vertical direction of the device.

[0033] The imaging apparatus 1 includes an imaging section 6 as an imaging unit, which is composed of imaging stations 6Y, 6M, 6C, and 6K arranged horizontally in a straight line, each corresponding to a toner (developer) for each color (i.e., yellow (Y), magenta (M), cyan (C), and black (K)). Inside the imaging section 6, photosensitive drums 7Y, 7M, 7C, and 7K (hereinafter referred to as photosensitive drums 7) and charging devices 8Y, 8M, 8C, and 8K (hereinafter referred to as charging devices 8) are arranged to uniformly charge the surface of the photosensitive drums 7. In addition, inside the imaging section 6, developing devices 9Y, 9M, 9C, and 9K (hereinafter referred to as developing devices 9) are arranged to attach toner to an electrostatic latent image and develop the electrostatic latent image into a toner image (developer image). Additionally, inside the imaging section 6, cleaning blades 10Y, 10M, 10C, and 10K (hereinafter referred to as photosensitive component cleaning blades 10) are arranged to remove residual toner from the photosensitive drum 7. In the developing apparatus 9, developing rollers 11Y, 11M, 11C, and 11K (hereinafter referred to as developing rollers 11) corresponding to each color are arranged such that they can contact and separate from each photosensitive drum 7. The developing rollers 11 are contacted or separated according to the electrostatic latent image, i.e., according to the developing requirements, thereby improving the product life of the developing rollers 11. Furthermore, a scanner unit 12 that emits a laser beam based on image information and forms an electrostatic latent image on the photosensitive drum 7 is arranged below the imaging section 6. Each imaging station 6Y, 6M, 6C, and 6K is configured as a processing box so that it can be detached from the main body of the imaging apparatus 1. The processing cartridge is configured to attach the developing apparatus 9, equipped with the developing roller 11, and the photosensitive unit, equipped with the photosensitive drum 7, charging device 8, and photosensitive component cleaning blade 10, individually or integrally to the apparatus body, or to detach them individually or integrally from the apparatus body. In Embodiment 1, the developing apparatus 9 includes its own toner receiving chamber, thereby replenishing the toner supplied from the supplementary toner container (toner cartridge) 13, which serves as a receiving portion, into the toner receiving chamber. Here, the apparatus body of the imaging apparatus 1 is referred to as the imaging apparatus 1, except for the structural parts that can be detached from the imaging apparatus (e.g., the processing cartridge and supplementary toner container 13 described above).

[0034] At the lower part of the imaging device 1, a drawer-shaped cassette 2 is housed. Recording materials 4, such as paper and sheets, are stored in the cassette 2. By rotating the paper feed cassette section 3 located near the front end of the recording materials 4, the recording materials 4 are separated and fed sheet by sheet. Each sheet of recording material 4 is then conveyed downstream via a blocking roller 5.

[0035] Intermediate transfer unit 16 is arranged above developing unit 9. Intermediate transfer unit 16 is arranged in a generally horizontal position such that its lower part faces the respective imaging stations (imaging sections) 6 (located on the side of primary transfer section 20). Intermediate transfer belt 18 facing each photosensitive drum 7 is a rotatable annular belt and is tensioned by multiple tension rollers. Primary transfer rollers 19Y, 19M, 19C, and 19K (hereinafter referred to as primary transfer rollers 19) are arranged as primary transfer components on the inner surface side of intermediate transfer belt 18. Each primary transfer roller 19 is arranged at a specific position to form respective primary transfer sections 20Y, 20M, 20C, and 20K (hereinafter referred to as primary transfer sections 20) with each photosensitive drum 7 via intermediate transfer belt 18. At each primary transfer section 20, the toner image is transferred from each photosensitive drum 7 to intermediate transfer belt 18 by the primary transfer roller 19 with applied voltage. In Example 1, the unit consisting of the intermediate transfer belt 18, a plurality of tensioning rollers for tensioning the intermediate transfer belt 18, and each primary transfer roller 19 can be detached from the main body of the device as an intermediate transfer unit 16.

[0036] The toner images developed by each imaging station are transferred from the primary transfer section 20 to the intermediate transfer belt 18, and by transferring each color in sequence, the four-color toner image is formed on the surface of the intermediate transfer belt 18 and is transported to the secondary transfer section 17.

[0037] At the lower part of the imaging section 6, toner replenishment containers 13Y, 13M, 13C, and 13K (hereinafter referred to as toner replenishment containers 13) that replenish toner to each imaging station (imaging section) 6 are arranged approximately horizontally and detachably between the scanner unit 12 and the cartridge 2. Also referred to as toner replenishment cartridges, the toner replenishment containers 13 store toner. Toner replenishment corresponding to each color is filled in the toner replenishment containers 13. Toner delivery devices 14Y, 14M, 14C, and 14K (hereinafter referred to as toner delivery devices 14) deliver toner received from the toner replenishment containers 13 upwards according to toner consumption in the imaging section 6, and supply toner to the developing unit 9. The toner delivery devices 14 deliver toner for forming an image. The toner delivery device 14, which serves as the toner delivery section, is driven by various toner delivery drive units 15Y, 15M, 15C, and 15K (hereinafter referred to as toner delivery drive units 15) arranged as drive units below the toner delivery device 14. Each toner delivery drive unit 15 includes: a motor, i.e., a power source, for providing driving force to the toner delivery device 14 via an upstream drive gear 1030 and a downstream drive gear 1120, mentioned later, to drive the various screws of the toner delivery device 14; and gears serving as drive transmission units.

[0038] The secondary transfer roller 21, serving as a secondary transfer component, contacts the intermediate transfer belt 18, thereby forming a secondary transfer section 17 via the intermediate transfer belt 18 and the rollers on the opposite side. The toner image transferred onto the intermediate transfer belt 18 is then transferred a second time onto the recording material 4 via the secondary transfer section 17. The cleaning unit 22 removes the toner remaining on the intermediate transfer belt 18 that was not transferred to the recording material 4 during the secondary transfer. The toner removed by the cleaning unit 22 is conveyed to the toner collection container 24 via the toner delivery section 23 and stored in the toner collection container 24.

[0039] The recording material 4, with the unfixed toner image transferred onto it, is further conveyed downstream and pressurized and heated by the heating unit 25a and pressure roller 25b of the fixing device 25. The toner image is then fixed onto the recording material 4 by the molten toner. The recording material 4 is then conveyed by the discharge roller pair 26 and discharged onto the paper transport tray 27. Through this series of operations, an image is formed on the surface of the recording material 4.

[0040] Toner delivery device

[0041] Figure 1 This is a schematic perspective view showing the overall structure of the toner delivery device 14 equipped in the imaging apparatus 1 of Embodiment 1. Figure 1 In the illustration, a portion of the toner delivery device 14 is omitted to show the internal structure of the toner delivery device 14.

[0042] The toner delivery device 14 mainly consists of an upstream delivery section 1000 (i.e., the first delivery section) and a downstream delivery section 1100 (i.e., the second delivery section). The upstream delivery section 1000 and the downstream delivery section 1100 deliver the toner used for imaging by the imaging section 6. The downstream delivery section 1100 delivers the toner delivered by the upstream delivery section 1000 vertically upwards.

[0043] A supply port (opening) 1010 for supplying toner to the upstream conveying section 1000 is arranged on the upper surface of the upstream conveying section 1000. From Figure 4 The toner supplied by the supplementary toner container 13 shown is supplied through the supply port 1010 into the first toner delivery channel formed by the upstream sidewall portion 1040 of the upstream side delivery section 1000. The supplied toner is delivered by the rotation of the upstream side screw 1050 (i.e., the first screw), which is arranged to be covered by the upstream sidewall portion 1040 of the upstream side delivery section 1000. The upstream side screw 1050 is driven to rotate by a rotational driving force transmitted from the toner delivery drive device 15 to the upstream side drive gear 1030. The upstream side screw 1050 delivers toner toward the downstream side delivery section 1100.

[0044] A downstream screw 1140 is arranged inside the downstream conveying section 1100 and is covered by the downstream sidewall portion 1130 of the downstream conveying section 1100. The upstream portion of the downstream conveying section 1100 is connected to the downstream portion of the upstream conveying section 1000. The toner conveyed by the upstream screw 1050 of the upstream conveying section 1000 is supplied to the interior of a second toner conveying channel, which is formed by the downstream sidewall portion 1130 of the downstream conveying section 1100. The toner inside the downstream conveying section 1100 is conveyed by the rotation of the downstream screw 1140 (i.e., the second screw). The downstream screw 1140 is driven by a rotational driving force transmitted from the toner conveying drive device 15 to the downstream drive gear 1120, and the downstream screw 1140 conveys the toner in the opposite direction of gravity (vertically upward). The toner conveyed by the downstream screw 1140 in the opposite direction of gravity is further conveyed by the discharge screw 1160 (i.e., the third screw) and discharged from the downstream conveying section 1100 via the discharge port 1110. The discharge screw 1160 has a rotating shaft and is rotatable. The upstream edge of the discharge screw 1160 contacts the downstream edge of the downstream screw 1140 for a driven connection, and the discharge screw 1160 rotates by a driving force received from the rotating downstream screw 1140. The toner discharged from the discharge screw 1160 through the discharge port 1110 is supplied (replenished) to... Figure 4 The developing apparatus 9 shown.

[0045] In conventional constructions, even in a cross-sectional view of an axially oriented screw arranged horizontally, a space is formed above the screw, as in Japanese Patent Application Publication No. 2014-157350. Figure 9 As shown, for example, the toner may also be conveyed along the axial direction of the screw without entering the space. In this case, the conveying force applied to the toner as it is conveyed from the upstream screw to the downstream screw is the resultant force of the radial conveying force generated by the screw and gravity.

[0046] Therefore, in the cases of the following configurations (1) and (2), in some cases, the toner may not be delivered smoothly because the radial delivery force of the screw alone is insufficient.

[0047] The configuration is (1) in which the downstream screw is located above the upstream screw in the vertical direction, and (2) in which the conveying channel is inclined such that the edge of the downstream screw becomes higher as it approaches the downstream of the conveying channel.

[0048] In the configurations (1) and (2) described above, the conveying efficiency is reduced due to the transmission section between the upstream and downstream screws. This results in a decrease in the maximum conveying force of the entire system relative to the maximum conveying force of each screw.

[0049] Therefore, in conventional imaging devices, the required toner dosage is set for the processing box, and in order to meet the set toner dosage, the rotation speed of the screw is increased so that the toner delivery amount becomes sufficient.

[0050] However, despite meeting the required toner delivery volume, operating noise increased with increasing screw rotation speed. Furthermore, the device's lifespan decreased due to the cumulative increase in screw rotation speed throughout the imaging device's product lifespan.

[0051] Furthermore, if the screw rotation speed is increased, the toner will be damaged more due to the friction and pressure it experiences during transport. The toner may also melt, which could interrupt the screw rotation and cause blockage of the transport channel.

[0052] Figures 2A to 2C This is a diagram showing the detailed structure of the connection portion (connection port) 1200 connecting the downstream conveying section 1100 to the upstream conveying section 1000. Figure 2A This is a top view of the toner delivery device 14. Figure 2B yes Figure 2A The sectional view at A1-A2 in the figure. Figure 2C yes Figure 2A The cross-sectional view at points B1-B2 is shown. The connecting portion 1200 of the downstream conveying section 1100 is an opening formed in the downstream conveying section 1100 and connects to an opening formed in the upstream conveying section 1000. The toner within the upstream conveying section 1000 is conveyed via the upstream screw 1050 at the portion where the connecting portion 1200 of the downstream conveying section 1100 is located. The connecting portion 1200 of the downstream conveying section 1100 is arranged downstream of the upstream screw 1050 in the toner conveying direction. The toner within the upstream conveying section 1000 flows into the downstream conveying section 1100 via the connecting portion 1200 of the downstream conveying section 1100.

[0053] like Figure 2B As shown, a degassing component 1020 is arranged on the upper surface of the upstream conveying section 1000. The degassing component 1020 is made of non-woven fabric, allowing air to pass through while preventing the toner from passing through. If the degassing component 1020 is not used, then when... Figure 4When the supplementary toner container 13 shown supplies toner, the air pressure in the upstream conveying section 1000 will increase. This increase in air pressure creates a pressure difference relative to the pressure in the supplementary toner container 13, thereby preventing toner from being supplied from the supplementary toner container 13 to the upstream conveying section 1000.

[0054] The upstream conveying section 1000 includes an upstream screw 1050 and an upstream sidewall portion (first conveying channel forming member) 1040 surrounding the upstream screw 1050, thereby forming a first conveying space 1080 surrounding the upstream screw 1050. The upstream sidewall portion 1040 surrounds the upstream screw 1050 and the first conveying space 1080 in the rotational direction of the upstream screw 1050. The first conveying space 1080 surrounds the upstream screw 1050 in the rotational direction of the upstream screw 1050. The first conveying space 1080 includes a first region 1060 and a second region 1070, the second region 1070 being closer to the connecting portion 1200 of the downstream conveying section 1100 than the first region 1060 in the toner conveying direction of the upstream screw 1050. The upstream sidewall portion 1040 includes a first wall portion 1040A surrounding the first region 1060 and a second wall portion 1040B surrounding the second region 1070. The first wall portion 1040A forms a first region 1060 surrounding the upstream screw 1050. The second wall portion 1040B forms a second region 1070 surrounding the upstream screw 1050.

[0055] The upstream screw 1050 includes a rotating shaft 1050A (i.e., a first rotating shaft) and a blade portion 1050B (i.e., a first blade portion) spirally arranged around the outer periphery of the rotating shaft 1050A. The blade portion 1050B is blade-shaped. The upstream screw 1050 is rotatably arranged in a generally horizontal direction within an upstream conveying section 1000 extending in a generally horizontal direction. The first portion of the upstream screw 1050 is arranged in a first region 1060 of a first conveying space 1080 of the upstream conveying section 1000, and the second portion of the upstream screw 1050 is arranged in a second region 1070 of the first conveying space 1080 of the upstream conveying section 1000. The first portion of the upstream screw 1050 includes an upstream end 1050A1 of the rotating shaft 1050A. The second portion of the upstream screw 1050 is a portion different from the first portion of the upstream screw 1050 and includes a downstream end 1050A2 of the rotating shaft 1050A. The upstream end 1050A1 of the rotating shaft 1050A is arranged in the first region 1060 of the first conveying space 1080 of the upstream side conveying section 1000, and the downstream end 1050A2 of the rotating shaft 1050A is arranged in the second region 1070 of the first conveying space 1080 of the upstream side conveying section 1000. Alternatively, the upstream end 1050A1 of the rotating shaft 1050A can be arranged in a region outside the upstream side conveying section 1000.

[0056] The downstream conveying section 1100 includes a downstream screw 1140 and a downstream sidewall portion (a second conveying channel forming member) 1130. The downstream sidewall portion 1130 forms a second conveying space 1150 surrounding the downstream screw 1140. The downstream sidewall portion 1130 surrounds the downstream screw 1140 and the second conveying space 1150 along the rotation direction of the downstream screw 1140. The second conveying space 1150 surrounds the downstream screw 1140 along the rotation direction of the downstream screw 1140. The downstream sidewall portion 1130 includes a connecting portion 1200. The connecting portion 1200 of the downstream sidewall portion 1130 is connected to the upstream sidewall portion 1040. A second region 1070 of the first conveying space of the upstream conveying section 1000 is connected to the second conveying space 1150 formed inside the downstream conveying section 1100 via the connecting portion 1200. The connecting portion 1200 is arranged along the axial direction of the rotation axis 1050A of the upstream screw 1050. The construction is not limited to this; the connecting portion 1200 of the downstream conveying section 1100 can also be arranged in a horizontal direction and in a direction perpendicular to the axis of rotation 1050A of the upstream screw 1050. The downstream screw 1140 includes a rotating shaft 1140A (i.e., a second rotating shaft) and a blade portion 1140B (i.e., a second blade portion) spirally arranged around the outer periphery of the rotating shaft 1140A. The blade portion 1140B is blade-shaped. The downstream screw 1140 is rotatably arranged in a generally vertical direction inside the downstream conveying section 1100, which extends in a generally vertical direction. The toner conveying direction of the downstream screw 1140 is, for example, the axial direction of the rotating shaft 1140A and is vertically upward.

[0057] The first wall portion 1040A includes a supply port 1010 for supplying toner to a first region 1060 of the first conveying space 1080. Toner is supplied from a replenishing toner container 13 to the upstream conveying section 1000 via the supply port 1010. Because the supply port 1010 is located in the first wall portion 1040A, toner passing through the supply port 1010 is supplied to the first region 1060 of the first conveying space 1080. The supply port 1010 is arranged vertically above the upstream screw 1050. The first region 1060 of the first conveying space 1080 is wider than the second region 1070 of the first conveying space 1080. In other words, the first conveying space 1080 includes a first region 1060 that is wider than the second region 1070. This is because even if excess toner is supplied from the replenishing toner container 13 to the upstream conveying section 1000, the toner will not overflow from the upstream conveying section 1000.

[0058] The first region 1060 has a cross-sectional area in a section perpendicular to the axis of rotation 1050A of the upstream screw 1050, determined by integrating the height H1 and width W1 of the first region 1060. The height H1 of the first region 1060 is its height in the vertical direction. The width W1 of the first region 1060 is its width in the horizontal direction and in the direction perpendicular to the axis of rotation 1050A of the upstream screw 1050. When viewed from a section perpendicular to the axis of rotation 1050A of the upstream screw 1050, the cross-sectional area of ​​the first region 1060 can be calculated by integrating the height and width of the toner delivery channel formed by the first wall portion 1040A. On the other hand, the second region 1070 is narrower than the first region 1060. The second region 1070 has a cross-sectional area in a section perpendicular to the axial direction of the rotation axis 1050A of the upstream screw 1050, determined by integrating the height H2 and the width W2 of the second region 1070. The height H2 of the second region 1070 is its vertical height. The width W2 of the second region 1070 is its width in the horizontal direction and in the direction perpendicular to the axial direction of the rotation axis 1050A of the upstream screw 1050. When viewed from a section perpendicular to the axial direction of the rotation axis 1050A of the upstream screw 1050, the cross-sectional area of ​​the second region 1070 can be calculated by integrating the height and width of the toner delivery channel formed by the second wall portion 1040B.

[0059] The height H2 of the second region 1070 is lower than the height H1 of the first region 1060. The width W1 of the first region 1060 is the same as the width W2 of the second region 1070. Therefore, the cross-sectional area of ​​the second region 1070, i.e., the cross-sectional area of ​​the connecting portion 1200 of the downstream conveying section 1100, is smaller than the cross-sectional area of ​​the first region 1060. Therefore, when the toner is conveyed by the upstream screw 1050 and transferred to the downstream screw 1140 of the downstream conveying section 1100, the pressure inside the second region 1070 of the first conveying space 1080 becomes higher than the pressure inside the first region 1060 of the first conveying space 1080. When the cross-sectional area of ​​the second region 1070 is smaller than the cross-sectional area of ​​the first region 1060, the height H2 of the second region 1070 can be lower than the height H1 of the first region 1060, and the width W2 of the second region 1070 can be narrower than the width W1 of the first region 1060. Furthermore, when the cross-sectional area of ​​the second region 1070 is smaller than that of the first region 1060, the height H2 of the second region 1070 can be smaller than the height H1 of the first region 1060, and the width W2 of the second region 1070 can be wider than the width W1 of the first region 1060.

[0060] In some cases where the pressure inside the second region 1070 of the first conveying space 1080 is low, it may be impossible to convey the toner in the direction opposite to the direction of gravity via the downstream screw 1140. To set the pressure inside the second region 1070 of the first conveying space 1080 to be higher than the pressure inside the first region 1060 of the first conveying space 1080, in this configuration, the width of the second region 1070 of the first conveying space 1080 is narrower than the width of the first region 1060 of the first conveying space 1080. In other words, in the axial direction of the rotation axis 1050A of the upstream screw 1050, the cross-sectional area of ​​the internal space surrounded by the upstream sidewall portion 1040 is smaller in the second region 1070 of the first conveying space 1080 than in the first region 1060 of the first conveying space 1080. The cross-sectional area of ​​the internal space surrounded by the upstream sidewall portion 1040 is the cross-sectional area perpendicular to the axial direction of the rotation axis 1050A of the upstream screw 1050. By making the width of the second region 1070 narrower than that of the first region 1060, pressure can be effectively applied to the connecting portion 1200 of the downstream conveying section 1100. As a result, the toner conveying efficiency from the upstream conveying section 1000 to the downstream conveying section 1100 can be improved. Furthermore, the toner can be easily conveyed in the opposite direction of gravity via the downstream screw 1140.

[0061] Figure 3 It's a diagram. Figures 2A to 2CThe graph shows the relationship between the spatial distance L of the second region 1070 of the first conveying space 1080 and the amount of toner conveyed by the downstream screw 1140 in the opposite direction of gravity. Figure 3 The horizontal axis in the figure represents the spatial distance L of the second region 1070. Figure 3 The vertical axis represents the amount of toner delivered by the downstream screw 1140 in the direction opposite to the direction of gravity. The spatial distance L of the second region 1070 is the length of the second region 1070 along the axial direction of the rotation axis 1050A of the upstream screw 1050. In other words, the spatial distance L is the length of the second wall portion 1040B along the axial direction of the rotation axis 1050A of the upstream screw 1050. Figure 3 The toner delivery rate on the vertical axis is defined as the ratio (%) relative to the maximum delivery rate.

[0062] also, Figure 3 This refers to data about the upstream screw 1050, which was measured using blade portions 1050B with different pitches. For example, the pitch of the blade portion 1050B is the distance between two adjacent protrusions of the blade portion 1050B when viewed in a direction perpendicular to the axial direction of the rotation axis 1050A of the upstream screw 1050. Figure 3 The solid line in the figure represents the measurement results of the upstream screw 1050 of the blade section 1050B with a pitch of 10 mm. Figure 3 The dashed line represents the measurement results of the upstream screw 1050 with a blade portion 1050B having a pitch of 20 mm. When the upstream screw 1050 has a blade portion 1050B with a pitch of 10 mm, the toner delivery rate is at least 100% when the spatial distance L is at least 10 mm. When the upstream screw 1050 has a blade portion 1050B with a pitch of 20 mm, the toner delivery rate is at least 100% when the spatial distance L is at least 20 mm. According to... Figure 3 According to the measurement results, when the spatial distance L is at least one pitch of the blade portion 1050B of the upstream screw 1050 in the second region 1070, the toner delivery amount of the downstream screw 1140 in the opposite direction of gravity can be maximized. In Embodiment 1, the blade portion 1050B is arranged in the rotation shaft 1050A such that the pitch of the blade portion 1050B of the upstream screw 1050 is smaller than the spatial distance L. Therefore, in the second region 1070, the blade portion 1050B of the upstream screw 1050 circulates around the rotation shaft 1050A at least once.

[0063] Example 2

[0064] Embodiment 2 of the present invention will now be described. Elements having the same or equivalent functions or structures as in Embodiment 1 are indicated by the same reference numerals, and their detailed descriptions are omitted.

[0065] Figures 5A to 5C This is a diagram showing the detailed structure of the connection portion (connection port) 1200 connecting the downstream conveying section 1100 to the upstream conveying section 1000 according to Embodiment 2. Figure 5A This is a top view of the toner delivery device 14. Figure 5B yes Figure 5A The sectional view at A1-A2 in the figure. Figure 5C yes Figure 5A The sectional view at points B1-B2.

[0066] Figures 5A to 5C The detailed structure of the connecting portion 1200 of the downstream conveying portion 1100 according to Embodiment 2 is shown. In the structure of Embodiment 2, unlike Embodiment 1, a difference is formed between the first region 1060 and the first region 1060 of the first conveying space 1080 by controlling the width direction of the toner conveying device 14.

[0067] The first wall portion 1040A includes a supply port 1010 for supplying toner to a first region 1060 of the first conveying space 1080. Toner is supplied from a replenishing toner container 13 to the upstream conveying portion 1000 via the supply port 1010. Because the supply port 1010 is located in the first wall portion 1040A, toner passing through the supply port 1010 is supplied to the first region 1060 of the first conveying space 1080. The supply port 1010 is vertically positioned above the upstream screw 1050. The first region 1060 of the first conveying space 1080 is wider than the second region 1070 of the first conveying space 1080. In other words, the first conveying space 1080 includes a first region 1060 that is wider than the second region 1070. The first region 1060 has a cross-sectional area in a section perpendicular to the axial direction of the rotation axis 1050A of the upstream screw 1050, determined by integrating the height H1 and width W1 of the first region 1060. On the other hand, the second region 1070 is narrower than the first region 1060. The second region 1070 has a cross-sectional area in a section perpendicular to the axial direction of the rotation axis 1050A of the upstream screw 1050, determined by integrating the height H2 and width W2 of the second region 1070.

[0068] The height H1 of the first region 1060 is the same as the height H2 of the second region 1070. The width W2 of the second region 1070 is narrower than the width W1 of the first region 1060. Therefore, the cross-sectional area of ​​the second region 1070, i.e., the cross-sectional area of ​​the connecting portion 1200 of the downstream conveying section 1100, is smaller than the cross-sectional area of ​​the first region 1060. Therefore, when the toner is conveyed by the upstream screw 1050 and transferred to the downstream screw 1140 of the downstream conveying section 1100, the pressure inside the second region 1070 of the first conveying space 1080 becomes higher than the pressure inside the first region 1060 of the first conveying space 1080. When the cross-sectional area of ​​the second region 1070 is smaller than the cross-sectional area of ​​the first region 1060, the width W2 of the second region 1070 can be narrower than the width W1 of the first region 1060, and the height H2 of the second region 1070 can be lower than the height H1 of the first region 1060. Furthermore, when the cross-sectional area of ​​the second region 1070 is smaller than that of the first region 1060, the width W2 of the second region 1070 can be narrower than the width W2 of the first region 1060, and the height H2 of the second region 1070 can be higher than the height H1 of the first region 1060.

[0069] If the pressure inside the second region 1070 of the first conveying space 1080 is low, it may be impossible to convey the toner in the opposite direction of gravity through the downstream screw 1140. To set the pressure inside the second region 1070 of the first conveying space 1080 to be higher than the pressure inside the first region 1060 of the first conveying space 1080, the width of the second region 1070 of the first conveying space 1080 is narrower than the width of the first region 1060 of the first conveying space 1080. In other words, in the axial direction of the rotation axis 1050A of the upstream screw 1050, the cross-sectional area of ​​the internal space surrounded by the upstream sidewall portion 1040 is smaller in the second region 1070 of the first conveying space 1080 than in the first region 1060 of the first conveying space 1080. The cross-sectional area of ​​the internal space surrounded by the upstream sidewall portion 1040 is the cross-sectional area perpendicular to the axial direction of the rotation axis 1050A of the upstream screw 1050. By making the width of the second region 1070 narrower than that of the first region 1060, pressure can be effectively applied to the connecting portion 1200 of the downstream conveying section 1100. As a result, the toner conveying efficiency from the upstream conveying section 1000 to the downstream conveying section 1100 can be improved. Furthermore, the toner can be easily conveyed in the opposite direction of gravity via the downstream screw 1140. According to the configuration of Embodiment 2, the height H1 of the first region 1060 can be reduced, thus reducing the height of the upstream conveying section 1000 of the toner conveying device 14.

[0070] Example 3

[0071] Embodiment 3 of the present invention will now be described. Elements having the same or equivalent functions or structures as in Embodiment 1 are indicated by the same reference numerals, and their detailed descriptions are omitted. Figure 6 This is a diagram showing the detailed structure of the connection portion (connection port) 1200 connecting the downstream conveying section 1100 to the upstream conveying section 1000 according to Embodiment 3.

[0072] The height H2 of the second region 1070 of the first conveying space 1080 is greater than the pitch P of the blade portion 1140B of the downstream screw 1140. The pitch P of the blade portion 1140B is, for example, the distance between two adjacent protrusions of the blade portion 1050B when viewed in a direction perpendicular to the axis of rotation 1140A of the downstream screw 1140. By making the height H2 of the second region 1070 of the first conveying space 1080 greater than the pitch P of the blade portion 1140B of the downstream screw 1140, more toner can be conveyed to the downstream screw 1140. Therefore, pressure can be effectively applied to the connecting portion 1200 of the downstream conveying section 1100. As a result, the amount of toner conveyed by the downstream screw 1140 in the direction opposite to the direction of gravity can be further increased.

[0073] In various embodiments, the downstream conveying section 1100 is arranged in a vertical direction, i.e., the downstream conveying section 1100 is arranged such that its longitudinal direction (the axial direction of the rotation axis 1140A of the downstream screw 1140) is aligned with the vertical direction. However, the construction of the toner conveying device of the present invention is not limited to this. A structure in which the longitudinal direction of the downstream conveying section 1100 is different from the vertical direction can be used. For example, the inclination angle of the longitudinal direction of the downstream conveying section 1100 relative to the horizontal direction or the longitudinal direction of the upstream conveying section 1000 (the axial direction of the rotation axis 1050A of the upstream screw 1050) can be at least 45 degrees and not more than 90 degrees.

[0074] The toner delivery device of the present invention can be used not only to deliver new toner (as described in each embodiment), but also to deliver waste toner (e.g., untransferred toner). In this case, the particles to be delivered may include not only waste toner, but also particles such as paper dust generated from recording materials, but the primary delivery target remains waste toner. Therefore, the particle delivery efficiency can be improved by using the same structure as in the various embodiments.

[0075] Example 4

[0076] Reference Figure 9 An imaging apparatus 1 according to embodiment 4 of the present invention is described. Figure 9It is a schematic cross-sectional view showing the overall structure of the imaging device 1, and is a cross-sectional view of the imaging device 1 viewed from the front side. Figure 9 This describes the structure of the imaging device in its normal mounting state, where the imaging device is arranged on a horizontal mounting surface, and... Figure 9 The left and right directions in the text correspond to the horizontal direction. Figure 9 The up and down directions in the diagram correspond to the vertical direction of the device.

[0077] The imaging apparatus 1 includes an imaging section 6 as an imaging unit, which is composed of imaging stations 6Y, 6M, 6C, and 6K arranged horizontally in a straight line, each corresponding to a toner (developer) for each color (i.e., yellow (Y), magenta (M), cyan (C), and black (K)). Inside the imaging section 6, photosensitive drums 7Y, 7M, 7C, and 7K (hereinafter referred to as photosensitive drums 7) and charging devices 8Y, 8M, 8C, and 8K (hereinafter referred to as charging devices 8) are arranged to uniformly charge the surface of the photosensitive drums 7. In addition, inside the imaging section 6, developing devices 9Y, 9M, 9C, and 9K (hereinafter referred to as developing devices 9) are arranged to attach toner to the electrostatic latent image formed on the photosensitive drums 7 and to develop the electrostatic latent image into a toner image (developer image). Additionally, inside the imaging section 6, cleaning blades 10Y, 10M, 10C, and 10K (hereinafter referred to as photosensitive component cleaning blades 10) are arranged to remove residual toner from the photosensitive drum 7. In the developing apparatus 9, developing rollers 11Y, 11M, 11C, and 11K (hereinafter referred to as developing rollers 11) corresponding to each color are arranged such that they can contact and separate from each photosensitive drum 7. The developing rollers 11 are contacted or separated according to the electrostatic latent image, i.e., according to the developing requirements, thereby improving the product life of the developing rollers 11. Furthermore, a scanner unit 12 that emits a laser beam based on image information and forms an electrostatic latent image on the photosensitive drum 7 is arranged below the imaging section 6. Each imaging station 6Y, 6M, 6C, and 6K is configured as a processing box so that it can be detached from the main body of the imaging apparatus 1. The processing cartridge is configured to attach the developing apparatus 9, equipped with the developing roller 11, and the photosensitive unit, equipped with the photosensitive drum 7, charging device 8, and photosensitive component cleaning blade 10, individually or integrally to the apparatus body, or to detach them individually or integrally from the apparatus body. In embodiment 4, the developing apparatus 9 includes its own toner reservoir, thereby replenishing the toner supplied from the supplementary toner container (toner cartridge) 13 into the toner reservoir. Here, the apparatus body of the imaging apparatus 1 is referred to as the imaging apparatus 1, except for the structural parts that can be detached from the imaging apparatus (e.g., the processing cartridge and supplementary toner container 13 described above).

[0078] At the lower part of the imaging device 1, a drawer-shaped cassette 2 is housed. Recording materials 4, such as paper and sheets, are stored in the cassette 2. By rotating the paper feed cassette section 3 arranged near the front end of the recording materials 4, the recording materials 4 are separated and fed sheet by sheet. Each sheet of recording material 4 is then conveyed downstream via a stop roller 5.

[0079] Intermediate transfer unit 16 is arranged above developing unit 9. Intermediate transfer unit 16 is arranged at a generally horizontal position such that its lower part faces the respective imaging stations (imaging sections) 6 (located on the side of primary transfer section 20). Intermediate transfer belt 18 facing each photosensitive drum 7 is a rotatable annular belt and is tensioned by multiple tension rollers. Primary transfer rollers 19Y, 19M, 19C, and 19K (hereinafter referred to as primary transfer rollers 19) are arranged as primary transfer components on the inner surface side of intermediate transfer belt 18. Each primary transfer roller 19 is arranged at a specific position to form respective primary transfer sections 20Y, 20M, 20C, and 20K (hereinafter referred to as primary transfer sections 20) with each photosensitive drum 7 via intermediate transfer belt 18. At each primary transfer section 20, the toner image is transferred from each photosensitive drum 7 to intermediate transfer belt 18 by the primary transfer roller 19 with applied voltage. In embodiment 4, the unit consisting of the intermediate transfer belt 18, a plurality of tensioning rollers for tensioning the intermediate transfer belt 18, and each primary transfer roller 19 can be detached from the main body of the device as an intermediate transfer unit 16.

[0080] The toner images developed by each imaging station are transferred from the primary transfer section 20 to the intermediate transfer belt 18, and by transferring each color in sequence, the four-color toner image is formed on the surface of the intermediate transfer belt 18 and is transported to the secondary transfer section 17.

[0081] At the lower part of the imaging section 6, toner replenishment containers 13Y, 13M, 13C, and 13K (hereinafter referred to as toner replenishment containers 13) that replenish toner to each imaging station (imaging section) 6 are arranged approximately horizontally and detachably between the scanner unit 12 and the cartridge 2. Toner replenishment containers 13 are also referred to as toner replenishment cartridges. Toner replenishment corresponding to each color is filled in toner replenishment containers 13. Toner delivery devices 14Y, 14M, 14C, and 14K (hereinafter referred to as toner delivery devices 14) deliver toner received from toner replenishment containers 13 upwards according to toner consumption in the imaging section 6, and supply toner to the developing unit 9. Toner delivery devices 14 are driven by toner delivery drive devices 15Y, 15M, 15C, and 15K (hereinafter referred to as toner delivery drive devices 15), which are drive units arranged below toner delivery devices 14.

[0082] The secondary transfer roller 21, serving as a secondary transfer component, contacts the intermediate transfer belt 18, thereby forming a secondary transfer section 17 via the intermediate transfer belt 18 and the roller on the opposite side. The toner image transferred onto the intermediate transfer belt 18 is then transferred a second time to the recording material 4 via the secondary transfer section 17. The recording material 4, with the unfixed toner image transferred onto it, is further conveyed downstream and pressurized and heated by the fixing device 25, whereby the toner image is fixed onto the recording material 4 by the molten toner. The recording material 4 is then discharged into the paper transport tray 27. Through this series of operations, an image is formed on the surface of the recording material 4.

[0083] In the imaging apparatus 1, a toner collection container (containing part) 24 is arranged for collecting waste toner discharged during the primary and secondary transfers. Since the imaging apparatus 1 is an electrophotographic system, the transfer is performed by electrostatic force during the primary and secondary transfers. Therefore, not the entire toner image of the transfer source is transferred; instead, a few percent of the toner image remains on the surface of the photosensitive drum 7 of the transfer source and on the surface of the intermediate transfer belt 18. The untransferred residual toner is removed to improve the stability of the image. The removed residual toner becomes waste toner and is collected in the toner collection container 24.

[0084] The waste toner conveying device (toner conveying device), which is part of the toner conveying section, includes waste toner conveying channels 51Y, 51M, 51C, and 51K (hereinafter referred to as waste toner conveying channel 51) and waste toner conveying channels 52, 53, and 54. Furthermore, the waste toner conveying device includes a drive unit (drive section) that rotates a screw to convey waste toner in each of the waste toner conveying channels 51, 52, 53, and 54.

[0085] The description will cover the conveying operation of waste toner (residual toner) from the primary transfer section 20 and the secondary transfer section 17 to the toner collection container 24.

[0086] The residual toner after the initial transfer (residual toner on the surface of the photosensitive drum 7) is collected by the photosensitive component cleaning blade 10 and conveyed in the order of waste toner conveying channels 51, 52, 53, and 54, and stored in the toner collection container 24. The residual toner in the secondary transfer section 17 (residual toner on the surface of the intermediate transfer belt 18) is collected by the cleaning unit 22. Then, the residual toner collected by the cleaning unit 22 is conveyed from the waste toner conveying channel 55 to the waste toner conveying channel 53, combined with the residual toner collected by the photosensitive component cleaning blade 10, and stored as waste toner in the toner collection container 24. The waste toner conveying device is included in and used by the imaging device 1. The waste toner conveying channels 51, 52, 53, and 54 can be detached from the imaging device 1.

[0087] Figure 8A The detailed construction of the waste toner delivery channels 52 and 53 included in the imaging device 1 is shown. Figure 8B The detailed internal structure is shown. Waste toner of each color flows from waste toner conveying channel 51 into waste toner conveying channel 52. Waste toner conveying channel 52 includes a rotatable screw 202 (first screw) for conveying waste toner (granules). Waste toner flowing into waste toner conveying channel 52 is conveyed to the downstream side of waste toner conveying channel 51 by the rotation of screw 202. Screw 202 is rotated by a rotational driving force transmitted from the drive unit (first drive part) to drive gear 201.

[0088] Waste toner conveying channel 53 is connected to waste toner conveying channel 52. Waste toner conveying channel 53 includes a rotatable downstream screw 204 (second screw) for conveying waste toner. Waste toner conveyed downstream of waste toner conveying channel 52 flows into waste toner conveying channel 53. Waste toner flowing into waste toner conveying channel 53 is conveyed vertically upward by the rotation of downstream screw 204. Downstream screw 204 is rotated by a rotational driving force transmitted from the drive unit (second drive section) to drive gear 203.

[0089] Next, the screw structure and its effects, which are features of Example 4, will be described. Figure 7 This is an explanatory diagram of a toner conveying device, showing the internal structure of the downstream side of the waste toner conveying channel 52 included in the toner conveying device. The screw 202, as a conveying component, includes a rotating shaft and is rotatable. The screw 202 includes a large-diameter screw portion 202a, a small-diameter screw portion 202b, a rotating shaft portion 202c (large-diameter shaft portion), and a rotating shaft portion 202d (small-diameter shaft portion). The large-diameter screw portion 202a is arranged spirally around the outer periphery of the rotating shaft portion 202c, and the small-diameter screw portion 202b is arranged spirally around the outer periphery of the rotating shaft portion 202d. The large-diameter screw portion 202a and the small-diameter screw portion 202b are blade-shaped blade portions.

[0090] The screw 202 includes a first screw portion consisting of a large-diameter screw portion 202a and a rotating shaft portion 202c, and a second screw portion consisting of a small-diameter screw portion 202b and a rotating shaft portion 202d. The first screw portion of the screw 202 is arranged on the upstream side of the waste toner conveying channel 52. The second screw portion of the screw 202 is arranged on the downstream side of the waste toner conveying channel 52. The point where the cross-sectional area of ​​the first screw portion of the screw 202 (the large-diameter screw portion 202a and the rotating shaft portion 202c) changes relative to the waste toner conveying channel 52 (the point of change of cross-sectional area) is arranged on the upstream side of the waste toner conveying direction (the upstream side of the waste toner conveying channel 52). The waste toner conveying direction on the waste toner conveying channel 52 is the direction of the rotating shaft of the screw 202, and is the direction toward the connection between the waste toner conveying channel 52 and the waste toner conveying channel 53. Waste toner delivery channel 52 is arranged in imaging device 1 such that the rotation axis of screw 202 is aligned with the horizontal direction.

[0091] The outer diameter (screw outer diameter) of the large-diameter screw section 202a is φDa1. Therefore, the outer diameter (diameter) of the first screw section, which is composed of the large-diameter screw section 202a and the rotating shaft section 202c, is φDa1. Half of the outer diameter (φDa1) of the large-diameter screw section 202a is the distance from the rotation center line (rotation axis) of the rotating shaft section 202c to the outer peripheral edge of the large-diameter screw section 202a. The second screw section of the screw 202 (the small-diameter screw section 202b and the rotating shaft section 202d) is arranged on the downstream side of the waste toner conveying direction (the downstream side of the waste toner conveying channel 52) relative to the point of change in cross-sectional area. The outer diameter of the small-diameter screw section 202b is φDa2. Therefore, the outer diameter of the second screw section, which is composed of the small-diameter screw section 202b and the rotating shaft section 202d, is φDa2. Half of the outer diameter (φDa2) of the small-diameter screw portion 202b is the distance from the rotation center line of the rotating shaft portion 202d to the outer peripheral edge of the small-diameter screw portion 202b. The large-diameter screw portion 202a and the small-diameter screw portion 202b are formed such that the outer diameter (φDa2) of the small-diameter screw portion 202b is smaller than the outer diameter (φDa1) of the large-diameter screw portion 202a (φDa1>φDa2).

[0092] The outer diameter of the rotating shaft portion 202c of the large-diameter screw portion 202a is φd1. The outer diameter of the rotating shaft portion 202d of the small-diameter screw portion 202b is φd2. The rotating shaft portions 202c and 202d are formed such that the outer diameter (φd2) of the rotating shaft portion 202d of the small-diameter screw portion 202b is smaller than the outer diameter (φd1) of the rotating shaft portion 202c of the large-diameter screw portion 202a (φd1>φd2).

[0093] Based on the outer diameter of the screw 202, a tube portion 101 (first tube) with an inner diameter of φDb1 and a tube portion 102 (second tube) with an inner diameter of φDb2 are arranged around the screw 202. Tube portion 101 is arranged upstream of the waste toner conveying channel 52. Tube portion 102 is arranged downstream of the waste toner conveying channel 52. Tube portions 101 and 102 are formed such that the inner diameter (φDb2) of tube portion 102 is smaller than the inner diameter (φDb1) of tube portion 101. Tube portions 101 and 102 constitute a tube 104 through which waste toner flows. Tube 104 is arranged on the waste toner conveying channel 52. The screw 202 is arranged inside the tube (inside tube 104). A hole 103, serving as an outlet (opening), is formed at the edge of tube portion 102, and the hole 103 is arranged downstream of the waste toner conveying channel 52.

[0094] The screw 202 extends to the vicinity of the hole 103 in the tube portion 102. In other words, the second screw portion of the screw 202 is arranged near the hole 103 in the tube portion 102. Figure 7 In the context of the tube portion 102, when viewed from a direction perpendicular to the rotation axis of the screw 202, the area near the hole 103 includes a region overlapping with the hole 103 and a peripheral region surrounding the overlapping region. Figure 7 In this configuration, the hole 103 is arranged in the tube portion 102 in a direction perpendicular to the rotation axis of the screw 202. The screw 202 extends to the vicinity of the hole 103 such that, when viewed in a direction perpendicular to the rotation axis of the screw 202, a portion of the screw 202 (the second screw portion) overlaps with a portion of the hole 103. The screw configuration is not limited to... Figure 7 In this configuration, when viewed along a direction perpendicular to the rotation axis of the screw 202, the screw 202 and the hole 103 may not overlap. Furthermore, the hole 103 may be arranged in the tube portion 102 facing the rotation axis of the screw 202. In this case, the screw 202 extends to the vicinity of the hole 103, such that when viewed along the rotation axis of the screw 202, a portion of the screw 202 (the second screw portion) overlaps with a portion of the hole 103. The screw configuration is not limited to this configuration; when viewed along the rotation axis of the screw 202, the screw 202 and the hole 103 may not overlap.

[0095] Waste toner delivered to the waste toner delivery channel 52 is pushed out through the hole 103 of the tube section 102 to the waste toner delivery channel 53 side. In other words, by rotating the screw 202, the waste toner inside the tube section 101 flows into the tube section 102, and the waste toner is discharged from the hole 103 of the tube section 102. This means that the hole 103 is a discharge outlet for discharging the waste toner inside the tube section 102. When the waste toner is delivered to the waste toner delivery channel 52, the waste toner is distributed in the waste toner delivery channel 52. Figure 7The area A1 shown by the slanted shaded line in the diagram, and the area (nearby area) on the side (peripheral side) of the waste toner delivery channel 52 near the hole 103, is filled with waste toner.

[0096] In conventional constructions, such as those in Japanese Patent Application Publication No. 2014-157350... Figure 9 In the arrangement shown, even if a space is formed above the screw in the axial direction section of the horizontally arranged screw, the toner will not enter the space, but will be conveyed along the axial direction of the screw. In this case, the conveying force applied to the toner when it is conveyed from the upstream screw to the downstream screw is the resultant force of the radial conveying force generated by the screw and gravity.

[0097] Therefore, in (1) the configuration in which the downstream screw is located above the upstream screw in the vertical direction, and in (2) the configuration in which the conveying channel is inclined such that the edge of the downstream screw becomes higher as it approaches the downstream of the conveying channel, the conveying force of the screw in the radial direction alone may not be sufficient, and thus the toner may not be conveyed smoothly.

[0098] In the configurations (1) and (2) described above, the conveying efficiency decreases due to the transmission section between the upstream and downstream screws. This results in a decrease in the maximum conveying force of the entire system relative to the maximum conveying force of each screw.

[0099] Therefore, in conventional imaging devices, the required toner dosage is set for the processing box, and in order to meet the set toner dosage, the rotation speed of the screw is increased so that the toner delivery amount becomes sufficient.

[0100] However, although the required toner delivery volume was met, the operating noise increased with the increase in screw rotation speed. Furthermore, the product lifespan of the device decreased due to the cumulative increase in the screw rotation speed in the particle delivery system throughout the product lifespan of the imaging device.

[0101] Furthermore, if the screw rotation speed increases, the toner will be damaged more due to the pressure and friction it experiences during transport. The toner may melt, and in the worst case, the melted toner may interrupt the screw rotation and cause blockage of the transport channel.

[0102] On the other hand, in Embodiment 4, the waste toner delivery channel 53 (second delivery channel) is connected to the hole 103 of the pipe portion 102. In other words, waste toner flows into the waste toner delivery channel 53 through the hole 103. The hole 103 can be regarded as a connection port connecting the waste toner delivery channel 52 and the waste toner delivery channel 53. Thus, when the waste toner flowing into the waste toner delivery channel 53 is conveyed upward in the vertical direction, the area near the hole 103 in the waste toner delivery channel 52 is filled with waste toner. Figure 7 The graph in the figure represents the effective cross-sectional area of ​​the conveying channel and the pressure applied to the waste toner in this state, with the horizontal axis representing the position of the waste toner in the conveying direction.

[0103] The effective cross-sectional area of ​​the conveying channel will now be described. The effective cross-sectional area of ​​the tube portion 101 is determined by subtracting the cross-sectional area of ​​the rotating shaft portion 202c of the screw 202 in the vertical direction from the cross-sectional area of ​​the tube portion 101 in the direction perpendicular to the rotation axis of the screw 202 (hereinafter referred to as the vertical direction). In other words, the effective cross-sectional area of ​​the tube portion 101 is the cross-sectional area of ​​the space formed between the inner wall 101a of the tube portion 101 and the rotating shaft portion 202c of the screw 202 in the vertical direction. The effective cross-sectional area of ​​the tube portion 102 is determined by subtracting the cross-sectional area of ​​the rotating shaft portion 202d of the screw 202 in the vertical direction from the cross-sectional area of ​​the tube portion 102 in the vertical direction. In other words, the effective cross-sectional area of ​​the tube portion 102 is the cross-sectional area of ​​the space formed between the inner wall 102a of the tube portion 102 and the rotating shaft portion 202d of the screw 202 in the vertical direction. The effective cross-sectional area of ​​the waste toner conveying channel 52 is either the effective cross-sectional area of ​​pipe section 101 or pipe section 102. The effective cross-sectional area of ​​the waste toner conveying channel 52 is the same as the cross-sectional area of ​​the area through which the waste toner passes in the waste toner conveying channel 52.

[0104] In Example 4, the outer diameter of the screw 202 is changed so that the effective cross-sectional area (downstream effective cross-sectional area) of the waste toner conveying channel 52 at the point of cross-sectional area change is different from the effective cross-sectional area (upstream effective cross-sectional area) of the waste toner conveying channel 52 at the point of cross-sectional area change. In other words, the effective cross-sectional area of ​​the waste toner conveying channel 52 is set such that the downstream effective cross-sectional area is smaller than the upstream effective cross-sectional area. For example, the effective cross-sectional area near the hole 103 in the waste toner conveying channel 52 (the effective cross-sectional area of ​​the tube portion 102) is smaller than the effective cross-sectional area of ​​the waste toner conveying channel 52 excluding the area near the hole 103 (the effective cross-sectional area of ​​the tube portion 101).

[0105] The pressure applied to the waste toner gradually increases downstream from the point of accumulation. That is, the amount of waste toner per unit cross-sectional area of ​​the waste toner conveying channel 52 increases from the point of accumulation. The cross-sectional area of ​​the waste toner conveying channel 52 decreases downstream from the point of cross-sectional area change. Therefore, the slope of the pressure increase applied to the waste toner increases from the point of cross-sectional area change, and the pressure applied to the waste toner finally reaches its maximum at the discharge point (orifice 103) of the waste toner conveying channel 52. Since the pressure applied to the waste toner reaches its maximum at the discharge outlet of the waste toner conveying channel 52, the pressure required to convey the waste toner vertically upward in the waste toner conveying channel 53 can be ensured. Thus, each time waste toner is supplied to the waste toner conveying channel 52, the waste toner can flow from the waste toner conveying channel 52 to the waste toner conveying channel 53.

[0106] In conventional conveying structures without a point of change in cross-sectional area, the slope of the pressure increase applied to the waste toner is relatively gentle from the accumulation start point of the conveying channel to the discharge outlet. Therefore, compared to the structure of Example 4, the accumulation start point in the conventional structure is located further upstream of the waste toner conveying channel 52. By reducing the effective cross-sectional area of ​​the waste toner conveying channel 52 downstream, as in the structure of Example 4, the amount of waste toner accumulated in the area between the accumulation start point and the discharge outlet of the waste toner conveying channel 52 can be relatively reduced.

[0107] When waste toner is pressed, it may melt or adhere together, causing blockage of the delivery channel. According to the construction of Example 4, the risk of blockage of the waste toner delivery channel 52 can be reduced by decreasing the amount of waste toner accumulating in the channel. Furthermore, by reducing the effective cross-sectional area of ​​the waste toner delivery channel 52 downstream, the flow velocity of the waste toner from the point of accumulation in the channel 52 to the discharge port is increased. Therefore, since the time required to move the waste toner inside the channel 52 is reduced, the time for pressure to be applied to the waste toner inside the channel 52 is also reduced. As a result, melting and adhesion of the waste toner can be prevented.

[0108] In Example 4, the length from the point of change in cross-sectional area of ​​the waste toner conveying channel 52 to the outlet (hole 103) is the same as one rotational pitch of the helical shape of the small-diameter screw portion 202b. The effective cross-sectional area (effective cross-sectional area of ​​pipe portion 102) of the region from the point of change in cross-sectional area of ​​the waste toner conveying channel 52 to the outlet (hole 103) is smaller than the effective cross-sectional area (effective cross-sectional area of ​​pipe portion 101) from the point of change in cross-sectional area of ​​the waste toner conveying channel 52 to the upstream edge. In the region from the point of change in cross-sectional area of ​​the waste toner conveying channel 52 to the outlet (hole 103), the small-diameter screw portion 202b circulates around the rotating shaft portion 202d at least once. This prevents flow in the waste toner conveying channel 52 in the direction opposite to the conveying direction of the waste toner, and the waste toner can be effectively conveyed to the downstream side of the waste toner conveying channel 52. As a result, the waste toner can be effectively discharged from the outlet (hole 103) of the waste toner conveying channel 52.

[0109] According to Embodiment 4, when waste toner is conveyed vertically upwards, the required inflow pressure to flow into the waste toner conveying channel 53 can be effectively generated. Therefore, the toner conveying efficiency on the downstream side of the toner conveying channel can be improved. Furthermore, the toner conveying efficiency in a toner conveying channel where gravity has a greater impact on the downstream side than the upstream side can be improved. Therefore, increased operating noise and reduced product lifespan due to increased screw rotation speed can be prevented. In addition, by setting the accumulation start point closer to the discharge port (hole 103) of the waste toner conveying channel 52, the area where pressure is applied to the waste toner is reduced, and the time the waste toner spends in the waste toner conveying channel 52 is shortened. This reduces damage to the waste toner.

[0110] In the configuration of Embodiment 4, the waste toner conveying channel 53 is arranged vertically, that is, the longitudinal direction of the waste toner conveying channel 53 (the direction of the rotation axis of the downstream screw 204) is consistent with the vertical direction. However, the present invention is not limited to this configuration. A configuration in which the longitudinal direction of the waste toner conveying channel 53 is different from the vertical direction can be used. Thus, similar effects can be obtained regardless of the inclination angle of the longitudinal direction of the waste toner conveying channel 53 relative to the vertical direction. Furthermore, similar effects can be obtained regardless of the angle of the longitudinal direction of the waste toner conveying channel 52 (the direction of the rotation axis of the screw 202) relative to the longitudinal direction of the waste toner conveying channel 53.

[0111] This invention is not limited to conveying waste toner, but similar effects can be achieved in configurations used to convey particles such as toner before development. For example, for the toner conveying device 14, a toner conveying channel with a similar configuration to the waste toner conveying channel 52 and a toner conveying channel with a similar configuration to the waste toner conveying channel 53 can be arranged. Furthermore, in embodiment 4, a parameter such as the outer diameter of the screw 202 is set for the portion before and after the cross-sectional area change point, respectively. However, the parameter such as the outer diameter of the screw 202 can be changed continuously, because this effect can be obtained by setting at least one stage of changing the outer diameter of the screw 202.

[0112] Example 5

[0113] Embodiment 5 of the present invention will now be described. Elements having the same or equivalent functions or structures as in Embodiment 4 are indicated by the same reference numerals, and their detailed descriptions are omitted. Figure 10 This is an explanatory diagram of a toner conveying device, showing the internal structure of the downstream side of the waste toner conveying channel 52. A pipe 401 is arranged in the waste toner conveying channel 52. A screw 405 is arranged in this pipe (inside the pipe 401). The screw 405 (conveyor component) has a rotating shaft and is rotatable. The screw 405 includes a rotating shaft portion 402 (small diameter shaft portion), a rotating shaft portion 403 (large diameter shaft portion), and a helical portion 404. The helical portion 404 is arranged helically around the outer periphery of the rotating shaft portions 402 and 403. The helical portion 404 is a blade-shaped blade portion.

[0114] The screw 405 includes a first screw portion consisting of a helical portion 404 and a rotating shaft portion 402, and a second screw portion consisting of a helical portion 404 and a rotating shaft portion 403. The first screw portion (helical portion 404 and rotating shaft portion 402) of the screw 405 is arranged upstream of the point where the cross-sectional area of ​​the waste toner conveying channel 52 changes (the point of change in cross-sectional area) in the waste toner conveying direction. The second screw portion (helical portion 404 and rotating shaft portion 403) of the screw 405 is arranged downstream of the point of change in cross-sectional area in the waste toner conveying direction (the downstream side of the waste toner conveying channel 52).

[0115] The outer diameter (outer diameter) of the helical portion 404 is φDa1'. Therefore, the outer diameter (diameter) of the screw 405 is φDa1'. Furthermore, the outer diameters of both the first and second screw portions of the screw 405 are φDa1'. Half of the outer diameter (φDa1') of the first screw portion of the screw 405 is the distance from the rotation center line of the rotating shaft portion 402 to the outer peripheral edge of the helical portion 404. Half of the outer diameter (φDa1') of the second screw portion of the screw 405 is the distance from the rotation center line of the rotating shaft portion 403 to the outer peripheral edge of the helical portion 404. The rotating shaft portion 402 and the rotating shaft portion 403 are configured such that the outer diameter (φd2') of the rotating shaft portion 403 is greater than the outer diameter (φd1') of the rotating shaft portion 402 (φd1' < φd2').

[0116] Around the screw 405, a tube 401 (tube section) with an inner diameter of φDb1' is arranged according to the outer diameter of the screw 405. A hole 406, serving as a discharge port (opening), is formed at the edge of the tube 401, and the hole 406 is arranged on the downstream side of the waste toner conveying channel 52.

[0117] The screw 405 extends to the vicinity of the hole 406 in the tube 401. In other words, the second screw portion of the screw 405 is positioned near the hole 406 in the tube 401. Figure 10 In the tube 401, the area near the hole 406 includes: a region overlapping with the hole 406 when viewed in a direction perpendicular to the rotation axis of the screw 405, and a peripheral region of this overlapping region. Figure 10 In this configuration, the hole 406 is arranged in the tube 401 in a direction perpendicular to the rotation axis of the screw 405. The screw 405 extends to the vicinity of the hole 406 such that, when viewed in a direction perpendicular to the rotation axis of the screw 405, a portion of the screw 405 (the second screw portion) overlaps with a portion of the hole 406. The screw configuration is not limited to... Figure 10 The screw 405 and the hole 406 are not necessarily arranged in the tube 401 in a manner that faces the rotation axis of the screw 405. In this case, the screw 405 extends to the vicinity of the hole 406, such that a portion of the screw 405 (the second screw portion) overlaps with a portion of the hole 406 when viewed along the rotation axis of the screw 405. The screw configuration is not limited to this configuration, and the screw 405 and the hole 406 may not overlap when viewed along the rotation axis of the screw 405.

[0118] Waste toner, conveyed to the waste toner conveying channel 52, is pushed out through the hole 406 of pipe 401 to the waste toner conveying channel 53 side. In other words, the waste toner is discharged from the hole 406 of pipe 401 by the rotation of screw 405. This means that hole 406 is the outlet for discharging waste toner from pipe 401. When waste toner is conveyed into waste toner conveying channel 52, the waste toner is distributed in waste toner conveying channel 52 by… Figure 10 The area A2, indicated by the slanted shading line, and the area (nearby area) in the waste toner delivery channel 52 near the hole 406 (peripheral side) are filled with waste toner.

[0119] Waste toner conveying channel 53 (second conveying channel) is connected to hole 406 in pipe 401. Waste toner flows into waste toner conveying channel 53 through hole 406. Hole 406 can be considered as a connection port connecting waste toner conveying channel 52 and waste toner conveying channel 53. Thus, when waste toner flowing into waste toner conveying channel 53 is conveyed vertically upwards, the area near hole 406 in waste toner conveying channel 52 is filled with waste toner. Figure 10 The graph in the figure represents the effective cross-sectional area of ​​the conveying channel and the pressure applied to the waste toner in this state, with the horizontal axis representing the position of the waste toner in the conveying direction.

[0120] The effective cross-sectional area of ​​the conveying channel will now be described. The effective cross-sectional area of ​​the region in which the first screw portion of the screw 405 is arranged in the pipe 401 is determined by subtracting the cross-sectional area of ​​the rotating shaft portion 402 in the vertical direction from the cross-sectional area of ​​the pipe 401 in the direction perpendicular to the rotation axis of the screw 405 (hereinafter referred to as the vertical direction). In other words, the effective cross-sectional area of ​​the region in which the first screw portion of the screw 405 is arranged in the pipe 401 (the effective cross-sectional area of ​​the first part of the pipe 401) is the cross-sectional area of ​​the space formed between the inner wall 401a of the pipe 401 and the rotating shaft portion 402 of the screw 405 in the vertical direction. The effective cross-sectional area of ​​the region in which the second screw portion of the screw 405 is arranged in the pipe 401 is determined by subtracting the cross-sectional area of ​​the rotating shaft portion 403 in the vertical direction from the cross-sectional area of ​​the pipe 401 in the direction perpendicular to the rotation axis of the screw 405 (hereinafter referred to as the vertical direction). In other words, the effective cross-sectional area of ​​the region in which the second screw portion of the screw 405 is arranged in the pipe 401 (the effective cross-sectional area of ​​the second portion of the pipe 401) is the cross-sectional area of ​​the space formed between the inner wall 401a of the pipe 401 and the rotation axis portion 403 of the screw 405 in the vertical direction. The effective cross-sectional area of ​​the waste toner conveying channel 52 is either the effective cross-sectional area of ​​the first portion of the pipe 401 or the effective cross-sectional area of ​​the second portion of the pipe 401.

[0121] In Example 5, the diameter of the rotating shaft of the screw 405 was increased without changing the outer diameter (φDa1') of the screw 405. Similar to Example 4, as... Figure 10 As shown in the graph depicting the effective cross-sectional area of ​​the conveying channel, the effective cross-sectional area of ​​the downstream side of the conveying channel relative to the point of change in cross-sectional area in the waste toner conveying direction can be reduced compared to the effective cross-sectional area of ​​the conveying channel on the upstream side in the waste toner conveying direction. For example, the effective cross-sectional area near the hole 406 in the waste toner conveying channel 52 (the effective cross-sectional area of ​​the second part of the pipe 401) is smaller than the effective cross-sectional area of ​​the area in the waste toner conveying channel 52 other than near the hole 406 (the effective cross-sectional area of ​​the first part of the pipe 401). Therefore, by using the same mechanism as described in Example 4, the pressure applied to the waste toner increases, and as in Example 4, the required inflow pressure into the waste toner conveying channel 53 can be effectively generated when the waste toner is conveyed vertically upward. Therefore, the toner conveying efficiency on the downstream side of the toner conveying channel can be improved. Furthermore, the toner conveying efficiency in a toner conveying channel in which the downstream side is more affected by gravity than the upstream side can be improved. Furthermore, by setting the accumulation start point closer to the outlet (hole 406) of the waste toner delivery channel 52, the area where pressure is applied to the waste toner is reduced, and the time the waste toner spends in the waste toner delivery channel 52 is decreased. This reduces damage to the waste toner.

[0122] In Example 5, the same effect as in Example 4 can be expected in terms of mechanism by using the same effective cross-sectional area of ​​the conveying channel. However, in Example 5, it is sufficient to change the screw shape and the shape of the components on the outer periphery of the screw when adjusting the screw shape according to the flow rate and conditions of the waste toner. Therefore, the construction of Example 5 is preferred in this case. In Example 5, the outer diameter of the screw is constant, but the effective cross-sectional area of ​​the conveying channel can be adjusted (in conjunction with Examples 4 and 5), and similar effects can be obtained even with this construction. Furthermore, as with Example 4, the present invention is not limited to conveying waste toner, but similar effects can be obtained even when conveying particles such as toner before development.

[0123] Example 6

[0124] Traditional electrophotographic imaging devices such as printers, copiers, and fax machines consist of three parts: a toner container that pre-stores toner; a toner delivery unit that delivers toner; and an imaging section located downstream of the toner delivery unit.

[0125] Traditionally, the construction used for conveying toner involves arranging a screw (which has a centrally located axis of rotation and includes blade portions that extend helically from the outer periphery of the screw) in a conveying channel, and conveying the toner from upstream to downstream of the conveying channel by rotating the screw.

[0126] Japanese Patent Application Publication No. 2014-157350 discloses a structure for dripping toner from a toner supply port of a toner bottle and conveying it to a developing apparatus via a toner delivery channel, wherein the toner bottle is arranged vertically on the upper side. In this case, the toner delivery channel consists of multiple interconnected screws, and the toner is delivered to the desired toner supply port by changing the delivery direction and height of the screws, as described in Japanese Patent Application Publication No. 2014-157350. Figure 9 and 11 shown.

[0127] For example, in Japanese patent application publication No. 2014-157350 Figure 10 In the configuration shown, two screws intersect to convey toner from upstream to downstream. At the conveying section, the downstream edge of the upstream screw and the upstream edge of the downstream screw are arranged to intersect and overlap in the vertical direction. When the toner conveyed by the upstream screw reaches the downstream edge of the upstream screw, the toner is guided by gravity to the downstream screw, and then the toner is further conveyed downstream through the downstream screw.

[0128] Japanese Patent Application Publication No. 2012-230358 also discloses a structure in which two screws intersect, allowing the toner to be transferred from the upstream screw to the downstream screw and conveyed. As shown in Figure 5 of Japanese Patent Application Publication No. 2012-230358, in this structure, the upstream and downstream screws intersect, allowing the toner to be conveyed downstream in the conveying direction.

[0129] In these prior art techniques, at the conveying section from the upstream screw to the downstream screw, the toner is subjected to gravity in addition to the conveying force of the screw. Through the combined force of gravity and the conveying force of the screw, the toner is pushed out from the conveying channel where the upstream screw is arranged, and the toner flows into the conveying channel where the downstream screw is arranged.

[0130] In this case, even in a sectional view taken along the axial direction of a horizontally arranged screw, a space is formed above the screw, as in Japanese Patent Application Publication No. 2014-157350. Figure 9 As shown, the toner is also conveyed along the axial direction of the screw without entering the space.

[0131] This indicates that the conveying force applied to the toner by the screw cannot overcome gravity to lift the toner upwards. This means that the radial conveying force generated by the screw is less than the gravity applied to the toner. In other words, the conveying force applied to the toner as it is transferred from the upstream screw to the downstream screw is the resultant force of the radial conveying force and gravity, and at least half of it is generated by gravity.

[0132] Therefore, the delivery force of the toner may become insufficient under the following conditions in which gravity becomes an obstacle to the delivery of the toner.

[0133] (1) is the case where the downstream screw is located above the upstream screw in the vertical direction.

[0134] As mentioned above, when conveying toner against gravity, the toner may not be conveyed smoothly because the conveying force of the screw in the radial direction alone is insufficient to convey the toner.

[0135] (2) is the case where the downstream screw is tilted so that the screw arrangement angle increases as it approaches the downstream side.

[0136] Especially in the case of a configuration where the downstream screw extends vertically, the upstream screw must overcome the radial conveying force generated by the downstream screw to push the toner from the upstream conveying channel to the downstream conveying channel through the connection port. Therefore, in some cases, a conventional upstream screw with insufficient conveying force may not be able to resist the backflow force of the downstream screw.

[0137] In the case of existing technology, if this structure is used, the conveying efficiency is reduced due to the transmission section between the upstream and downstream screws, and the maximum conveying force of the entire system is reduced relative to the maximum conveying force of each screw.

[0138] In conventional imaging devices, the required toner dosage is set for the processing cartridge, and in order to meet this toner dosage, the rotation speed of the screw is increased so that the required toner delivery amount becomes sufficient.

[0139] However, despite meeting the required delivery volume, the operating noise also increases with the increase in rotational speed. Furthermore, the product lifespan of the device decreases due to the increased cumulative rotational speed of the screw within the toner delivery device throughout its product lifecycle.

[0140] Furthermore, if the cross-sectional area of ​​the screw is increased to increase the conveying force without increasing the screw's rotational speed, the volume of the device increases, which affects the overall size of the entire imaging device.

[0141] Therefore, the following section will describe a technique to improve the toner delivery efficiency in a toner delivery channel where the downstream side is more affected by gravity than the upstream side.

[0142] Reference Figure 13 An imaging apparatus 1 according to embodiment 6 of the present invention is described. Figure 13 It is a schematic cross-sectional view showing the overall structure of the imaging device 1, and is a cross-sectional view of the imaging device 1 viewed from the front side. Figure 13 This describes the structure of the imaging device in its normal installation state, where the imaging device is arranged on a horizontal mounting surface, and... Figure 13 The left and right directions in the middle correspond to the horizontal direction, while Figure 13 The up and down directions in the text correspond to the vertical direction of the device. (Except for the following references...) Figure 13 In the description of the accompanying drawings other than those shown, descriptions relating to direction (e.g., left and right, up and down) are based on Figure 13 .

[0143] The imaging apparatus 1 includes an imaging section 6 as an imaging unit, which is composed of imaging stations 6Y, 6M, 6C, and 6K arranged horizontally in a straight line, each corresponding to a toner (developer) for each color (i.e., yellow (Y), magenta (M), cyan (C), and black (K)). Inside the imaging section 6, photosensitive drums 7Y, 7M, 7C, and 7K (hereinafter referred to as photosensitive drums 7) and charging devices 8Y, 8M, 8C, and 8K (hereinafter referred to as charging devices 8) are arranged to uniformly charge the surface of the photosensitive drums 7. In addition, developing devices 9Y, 9M, 9C, and 9K (hereinafter referred to as developing devices 9) are arranged to attach toner to an electrostatic latent image and develop the electrostatic latent image into a toner image (developer image). Additionally, individual photosensitive component cleaning blades 10Y, 10M, 10C, and 10K (hereinafter referred to as photosensitive component cleaning blades 10) are arranged to remove residual toner remaining on the photosensitive drum 7. In the developing apparatus 9, individual developing rollers 11Y, 11M, 11C, and 11K (hereinafter referred to as developing rollers 11) corresponding to each color are arranged such that they can contact and separate from each photosensitive drum 7. The developing rollers 11 are contacted or separated according to the electrostatic latent image, i.e., according to the developing requirements, thereby improving the product life of the developing rollers 11. Furthermore, a scanner unit 12 that emits a laser beam based on image information and forms an electrostatic latent image on the photosensitive drum 7 is arranged below the imaging section 6. Each imaging station 6Y, 6M, 6C, and 6K is configured as a processing box so that it can be detached from the main body of the imaging apparatus 1. The processing cartridge is configured to attach the developing apparatus 9, equipped with the developing roller 11, and the photosensitive unit, equipped with the photosensitive drum 7, charging device 8, and photosensitive component cleaning blade 10, individually or integrally to the apparatus body, or to detach them individually or integrally from the apparatus body. In embodiment 6, the developing apparatus 9 includes its own toner receiving chamber, thereby replenishing the toner supplied from the supplementary toner container (toner cartridge) 13, which will be mentioned later, into the toner receiving chamber. Here, the apparatus body of the imaging apparatus 1 is referred to as the imaging apparatus, except for the components that can be detached from the imaging apparatus 1 (e.g., the processing cartridge mentioned above and the supplementary toner container 13 mentioned later).

[0144] At the lower part of the imaging device 1, a drawer-shaped cassette 2 is housed. Recording materials 4, such as paper and sheets, are stored in the cassette 2. By rotating the paper feed cassette section 3 arranged near the front end of the recording materials 4, the recording materials 4 are separated and fed sheet by sheet. Each sheet of recording material 4 is then conveyed downstream via a stop roller 5.

[0145] Intermediate transfer unit 16 is arranged above developing unit 9. Intermediate transfer unit 16 is arranged in a generally horizontal position such that its lower part faces each imaging station (imaging section) 6 (located on the side of primary transfer section 20). Intermediate transfer belt 18 facing each photosensitive drum 7 is a rotatable annular belt and is tensioned by multiple tension rollers. Each primary transfer roller 19Y, 19M, 19C, and 19K (hereinafter referred to as primary transfer roller 19) is arranged as a primary transfer component on the inner surface side of intermediate transfer belt 18. Each primary transfer roller 19 is arranged at a specific position to form each primary transfer section 20Y, 20M, 20C, and 20K (hereinafter referred to as primary transfer section 20) with each photosensitive drum 7 via intermediate transfer belt 18. At each primary transfer section 20, the toner image is transferred from each photosensitive drum 7 to intermediate transfer belt 18 by the primary transfer roller 19 with applied voltage. In embodiment 6, the unit consisting of the intermediate transfer belt 18, a plurality of tensioning rollers for tensioning the intermediate transfer belt 18, and each primary transfer roller 19 can be detached from the main body of the device as an intermediate transfer unit 16.

[0146] The toner images developed by each imaging station are transferred from the primary transfer section 20 to the intermediate transfer belt 18, and by transferring each color in sequence, the four-color toner image is formed on the surface of the intermediate transfer belt 18 and is transported to the secondary transfer section 17.

[0147] At the lower part of the imaging section 6, toner replenishment containers (toner replenishment cassettes) 13Y, 13M, 13C, and 13K (hereinafter referred to as toner replenishment containers 13) that replenish toner to each imaging station (imaging section) 6 are arranged approximately horizontally and detachably between the scanner unit 12 and the cassette 2. Toner replenishment corresponding to each color is filled in the toner replenishment container 13. Each toner delivery device 14Y, 14M, 14C, and 14K (hereinafter referred to as toner delivery device 14) delivers toner received from the toner replenishment container 13 upwards according to toner consumption within the imaging section 6 and supplies toner to the developing unit 9. The toner delivery device 14 is driven by toner delivery drive devices 15Y, 15M, 15C, and 15K (hereinafter referred to as toner delivery drive devices 15), which are drive units arranged below the toner delivery device 14. The toner delivery drive unit 15 includes: a motor, i.e. a power source, for providing driving force to the toner delivery unit 14 via the upstream drive gear 303 and the downstream drive gear 112, which will be mentioned later, to drive the various screws of the toner delivery unit 14; and gears as drive transmission units.

[0148] The secondary transfer roller 21, serving as a secondary transfer component, contacts the intermediate transfer belt 18, thereby forming a secondary transfer section 17 via the intermediate transfer belt 18 and the rollers on the opposite side. The toner image transferred onto the intermediate transfer belt 18 is then transferred a second time onto the recording material 4 via the secondary transfer section 17. The cleaning unit 22 removes the toner remaining on the intermediate transfer belt 18 that was not transferred to the recording material 4 during the secondary transfer. The toner removed by the cleaning unit 22 is conveyed to the toner collection container 24 via the toner delivery section 23 and stored in the toner collection container 24.

[0149] The recording material 4, with the unfixed toner image transferred through the secondary transfer section 17, is further conveyed downstream and pressurized and heated by the heating unit 25a and pressure roller 25b of the fixing device 25. The toner image is then fixed onto the recording material 4 by the molten toner. The recording material 4 is then conveyed by the discharge roller pair 26 and discharged to the paper transport tray 27. Through this series of operations, an image is formed on the surface of the recording material 4.

[0150] Toner delivery device

[0151] Figure 11 This is a schematic perspective view showing the overall structure of the toner delivery device 14 equipped in the imaging apparatus of Embodiment 6. Figure 11 In the illustration, a portion of the toner delivery device 14 is omitted to show the internal structure of the toner delivery device 14.

[0152] The toner conveying device 14 mainly consists of an upstream conveying section 100 and a downstream conveying section 110.

[0153] The supply port 301 is arranged on the upper surface of the upstream conveying section 100, and from... Figure 13 The toner supplied by the supplementary toner container 13 shown is supplied through the supply port 301 into a first toner delivery channel formed by the upstream sidewall surface 304 inside the upstream side delivery section 100. The supplied toner is delivered by the rotation of the upstream side screw 105 (i.e., the first screw), which is arranged to be covered by the upstream sidewall surface 304 inside the upstream side delivery section 100. The upstream side screw 105 is driven to rotate by a rotational driving force transmitted from the toner delivery drive device 15 to the upstream side drive gear 303, and the upstream side screw 105 delivers toner to the downstream side delivery section 110.

[0154] The upstream conveying section 100 includes: a first conveying channel forming component that forms a first toner conveying channel 108 on the upstream side; a second conveying channel forming component that forms a portion of the upstream side of a second toner conveying channel 109 on the downstream side; and a connection port 107 that connects the first toner conveying channel 108 and the second toner conveying channel 109.

[0155] The upstream screw 105 includes a rotating shaft 105A (i.e., a first rotating shaft) and a blade portion 105B that is spirally arranged around the outer periphery of the rotating shaft 105A.

[0156] In the conveying channel formed by the upstream conveying section 100, the upstream screw 105 is rotatably arranged in a generally horizontal direction within a first toner conveying channel 108 that extends in a generally horizontal direction and is formed by the first conveying channel forming member. The upstream screw 105 is configured such that the edge of the rotating shaft 105A on the side that is drivenly connected to the upstream drive gear 303 (the upstream edge of the upstream conveying section 100 in the toner conveying direction) is rotatably supported by the housing of the upstream conveying section 100.

[0157] The connection port 107 is arranged to connect to the first toner delivery channel 108 along the axial direction of the rotation axis 105A of the upstream screw 105.

[0158] In the upstream side conveying section 100, the upstream end of the upstream side portion of the second toner conveying channel 109 formed by the second conveying channel forming component is located at the end (downstream side) of the connection port 107 in the axial direction of the rotation shaft 105A, and extends upward (in the direction opposite to the direction of gravity) from the upstream end.

[0159] In other words, the conveying channel formed by the upstream conveying section 100 has an approximate L-shape consisting of the upstream side portion of the first toner conveying channel 108, the connection port 107, and the second toner conveying channel 109.

[0160] The downstream conveying section 110 includes a second conveying channel forming member that forms a second toner conveying channel 109, which extends substantially vertically (in the opposite direction to gravity) downstream of the first toner conveying channel 108. The second conveying channel forming member of the downstream conveying section 110 forms the main portion 109b of the second toner conveying channel 109, except for the upstream portion 109a of the second toner conveying channel 109 formed by the second conveying channel forming member of the upstream conveying section 100. In other words, the upstream portion 109a of the second toner conveying channel 109 is formed by the upstream conveying section 100, and the downstream portion 109b is formed from there by the downstream conveying section 110. This means that the second conveying channel forming member forming the second toner conveying channel 109 extends across both the upstream conveying section 100 and the downstream conveying section 110.

[0161] The second conveying channel forming member of the upstream conveying section 100 has an opening that opens the second toner conveying channel 109 upwards, and is configured such that the lower end (upstream end) of the second conveying channel forming member of the downstream conveying section 110 is inserted into the opening from above. Through this connection, the second toner conveying channel 109a of the upstream conveying section 100 and the second toner conveying channel 109b of the downstream conveying section 110 are connected, thereby forming a second toner conveying channel 109.

[0162] The first toner delivery channel 108 is the space formed between the upstream sidewall surface 304 of the upstream delivery section 100 and the upstream screw 105.

[0163] The second toner delivery channel 109 is the space formed between the downstream sidewall 113 extending across the upstream delivery section 100 and the downstream delivery section 110 and the downstream screw 114.

[0164] The downstream screw 114, i.e. the second screw, is rotatably arranged in the vertical direction inside the second toner delivery channel 109 and is accommodated extending across the portion (109b) inside the downstream delivery section 110 and the portion (109a) inside the upstream delivery section 100.

[0165] Inside the downstream conveying section 110, the downstream screw 114 is arranged to be covered by the downstream side wall 113. The upstream portion of the downstream conveying section 110 is connected to the downstream portion of the upstream conveying section 100, and the toner conveyed by the upstream screw 105 of the upstream conveying section 100 passes through the connection port 107 and is then conveyed by the downstream screw 114. The downstream screw 114 is rotated by a rotational driving force transmitted from the toner conveying drive device 15 to the downstream drive gear 112, and the downstream screw 114 conveys the toner in the opposite direction to the direction of gravity. The downstream screw 114 is configured such that the edge of the rotating shaft 114A on the side driven by the downstream drive gear 112 (the upstream edge of the downstream conveying section 110 in the toner conveying direction) is rotatably supported by the housing of the downstream conveying section 110. The toner conveyed by the downstream screw 114 in the opposite direction to gravity is further conveyed by the discharge screw 116 (i.e., the third screw) and discharged from the downstream conveying section 110 via the discharge port 111. The upstream edge of the blade portion of the discharge screw 116 is driven to contact the downstream edge of the blade portion of the downstream screw 114, and the discharge screw 116 rotates by a driving force received from the rotating downstream screw 114. The toner discharged from the discharge port 111 via the discharge screw 116 is supplied (replenished) to… Figure 13 The developing apparatus 9 shown.

[0166] Figures 12A to 12C This is a diagram showing the detailed structure of the connection portion (connection port 107) between the first toner delivery channel 108 and the second toner delivery channel 109 mentioned above. Figure 12A This is a top view of the toner delivery device 14. Figure 12B yes Figure 12A The cross-sectional view at A-A' only shows the connection part of the toner delivery device 14. Figure 12C yes Figure 12A The sectional view at point B-B'.

[0167] like Figure 12B As shown, the degassing component 302 is arranged on the upper surface of the upstream conveying section 100. The degassing component 302 is made of non-woven fabric, allowing air to pass through while preventing the toner from passing through. If the degassing component 302 is not used, then when... Figure 13 When the supplementary toner container 13 shown supplies toner, the air pressure in the space within the upstream conveying section 100 will increase. This increase in air pressure creates a pressure difference relative to the pressure in the supplementary toner container 13, thereby preventing toner from being supplied from the supplementary toner container 13 to the upstream conveying section 100.

[0168] The toner supplied from the replenishing toner container 13 is first conveyed by the upstream screw 105 and then by the downstream screw 114. A space is created along the axial direction of the rotation axis 105A between the downstream end 105a of the rotation axis 105A of the upstream screw 105 and the outer diameter end 114a of the blade portion 114B of the downstream screw 114. The area that creates this space can be considered as a connection port 107. The length of this space (the connection length of the connection port 107) can be appropriately set according to the specifications of the device. Based on this length, the toner in this space (within the connection port 107) can be conveyed to the second toner delivery channel 109 located on the downstream side by the rotational conveying force of the upstream screw 105.

[0169] In the second toner delivery channel 109 located downstream of this space (connection port 107), the downstream screw 114 delivers toner in the opposite direction to gravity, while the upstream screw 105 is rotated to supply toner to the downstream screw 114. In some cases, toner may flow back from the downstream screw 114 to the upstream screw 105. In other words, toner that falls into the second toner delivery channel 109 due to gravity returns to the first toner delivery channel 108 via this space (connection port 107). This backflow of toner reduces the efficiency of transferring toner from the upstream screw 105 to the downstream screw 114.

[0170] The force that delivers the toner via the horizontally extending upstream screw 105 is primarily generated in the region below the rotation axis 105c of the rotating shaft 105A. Therefore, the toner backflow is primarily generated in the region above the rotation axis 105c, while simultaneously, the flow of toner from the upstream screw 105 to the downstream screw 114 is generated in the region below the rotation axis 105c.

[0171] Therefore, an anti-backflow rib (protrusion) 106 is provided at the connection port 107, which is the connection between the first toner delivery channel 108 and the second toner delivery channel 109. This anti-backflow rib 106 is continuously formed from the inner wall surface 113 constituting the second toner delivery channel 109 along the rotation axis direction of the rotation shaft 114A of the downstream screw 114, so as to cover the outer diameter end (outer peripheral end) 114a of the blade portion 114B of the downstream screw 114. Moreover, the anti-backflow rib 106 is formed to protrude from the area covering the outer diameter end (outer peripheral end) 105b of the blade portion 105B of the upstream screw 105 in the gravity direction (the upper end of the inner wall surface 304), that is, protruding from a part of the inner wall surface 304 constituting the first toner delivery channel 108. In other words, the anti-backflow rib 106 protrudes from the inner wall surface 304 toward the rotation axis 105c in a direction perpendicular to the rotation axis 105c of the rotation axis 105A. When viewed along the rotation axis 105c of the rotation axis 105A, the anti-backflow rib 106 is arranged to overlap with the blade portion 105B. Due to the anti-backflow rib 106, the width of the connection portion (connection port 107) between the first toner delivery channel 108 and the second toner delivery channel 109 becomes narrower than the width of the space located on the downstream side of the downstream edge of the rotation axis 105A of the first toner delivery channel 108.

[0172] Regarding the amount of the anti-backflow rib 106 protruding from the inner wall surface 304, the key point is that the anti-backflow rib 106 protrudes from the outer diameter end 105b of the upstream screw 105 toward the rotation axis (rotation center axis) 105c, and is located above the rotation center axis 105c in the vertical direction when viewed along the direction of the rotation center axis 105c. By forming the anti-backflow rib 106 within this protrusion range, the amount of toner backflow from the downstream screw 114 to the upstream screw 105 can be reduced without reducing the amount of toner transferred from the upstream screw 105 to the downstream screw 114.

[0173] The anti-backflow rib 106 is formed from a single continuous rib, but it can also be formed discontinuously from multiple ribs. In embodiment 6, the end of the anti-backflow rib 106 is located on a horizontal line along the axis of rotation 105c (e.g., Figure 12C (as shown), but it can be an arc or a diagonal.

[0174] According to Embodiment 6, even in a conveying channel configuration where the influence of gravity is greater downstream than upstream, making toner delivery difficult, the toner delivery efficiency will not decrease at the joint where the toner delivery direction changes in a way that increases the influence of gravity, and drawbacks such as increased operating noise and reduced product life can be prevented. In other words, according to Embodiment 6, when at least two screws are connected, the conveying force of the upstream screw can be used to effectively deliver the toner to the downstream screw at the toner delivery section. Therefore, the screw rotation speed can be minimized relative to the required toner delivery amount, resulting in power savings and reduced noise. Similarly, the screw outer diameter can be minimized relative to the required toner delivery amount, resulting in a reduction in the overall size of the device.

[0175] Example 7

[0176] Reference Figure 14 Embodiment 7 of the present invention is described. Figure 14 This is a schematic cross-sectional view showing the detailed construction of the connection portion (connection port 107) located between the first toner delivery channel 108 and the second toner delivery channel 109 in the toner delivery device according to Embodiment 7.

[0177] In the construction of the imaging apparatus and toner delivery apparatus according to Embodiment 7, the same components as those in the apparatus according to Embodiment 6 are indicated by the same reference numerals, and their repeated descriptions are omitted. Matters not specifically described in Embodiment 7 are the same as in Embodiment 6.

[0178] In Embodiment 7, unlike Embodiment 6, the anti-backflow rib 106 protrudes discontinuously from the inner wall surface 304 constituting the first toner delivery channel 108, independent of (discontinuously from) the inner wall surface 113 constituting the second toner delivery channel 109. This is based on the assumption that the anti-backflow rib 106 cannot be continuously formed from the inner wall surface 113 due to limitations of the mold used for molding the upstream delivery section 100 and the downstream delivery section 110. According to Embodiment 7, regardless of mold limitations, the backflow of toner from the downstream screw 114 to the upstream screw 105 can be reduced without reducing the amount of toner delivered from the upstream screw 105 to the downstream screw 114.

[0179] Example of the construction of anti-backflow ribs (protruding parts)

[0180] Reference Figures 15A to 15C Describe a construction example of the anti-backflow rib 106. Figures 15A to 15CThis is a schematic diagram showing an example of the construction of the upstream screw 105's rotation axis 105A, anti-backflow rib 106, connection port 107, and inner wall surface 304 constituting the first toner delivery channel 108 when viewed along the rotation axis 105c of the upstream screw 105's rotation axis 105A. Figure 15A The structure of the single anti-backflow rib 106 described in the above embodiments is as follows. Figure 15B This refers to the structure when multiple anti-backflow ribs 106 are arranged. Figure 15C It is a construction that reduces toner backflow by optimizing the positional relationship between the connection port 107 and the rotating shaft 105A, without including the anti-backflow rib 106.

[0181] The specific construction of the anti-backflow rib 106 is not limited to the construction of the above embodiment. In other words, various constructions can be used for the connection port 107, as long as the flow of toner is blocked in the area above the rotation axis 105c of the rotation axis 105A of the upstream screw 105 where toner backflow is likely to occur, but the flow of toner is not blocked in the area below the rotation axis 105c. In other words, other constructions without the anti-backflow rib 106 can be used, as long as the width of the connection port 107 is set such that the area above the rotation axis 105c is narrower than the area below the rotation axis 105c. For example, as... Figure 15C As shown, the opening of the connector 107 is set such that the area above the rotation axis 105c is narrower than the area below the rotation axis 105c, thereby achieving an effect similar to the construction using the anti-backflow rib 106 described in the above embodiment. The connector 107 is in... Figures 15A to 15C The connection port 107 is constructed to have a rectangular shape, but is not limited to that shape. The connection port 107 can have various shapes, such as circular or polygonal. The anti-backflow rib 106 is also shaped in this way.

[0182] other

[0183] The configuration of the components that make up the first toner delivery channel, the connector, and the second toner delivery channel (where the upstream delivery portion 100 and the downstream delivery portion 110 are separated) is not limited to the configuration described in the embodiments.

[0184] For example, the upstream conveying section 100 and the downstream conveying section 110 can be separated at the connection port 107. In other words, in the upstream conveying section 100, a first opening portion is arranged that opens at the downstream end of the first toner conveying channel 108, and in the downstream conveying section 110, a second opening portion that opens at the upstream end of the second toner conveying channel 109 is arranged to connect to the first opening portion along the axis of rotation 105A of the upstream screw 105. Thus, the connection port 107 can be formed by the first opening portion and the second opening portion connected along the axis of rotation 105A of the upstream screw 105. Then, by arranging anti-backflow ribs (protrusions) at the edges of at least one of the first opening portion and the second opening portion, or by making the widths of the respective opening portions different, the backflow of toner can be reduced.

[0185] Furthermore, regarding the portion of the connection port 107 that serves as a third toner delivery channel (with a short delivery distance), the third delivery channel forming portion constituting the third toner delivery channel can be configured differently from the first delivery channel forming component constituting the first toner delivery channel 108 and the second delivery channel forming component constituting the second toner delivery channel 109. In this case, in the region above the rotation axis of the rotation shaft 105A, the width of the third toner delivery channel formed by the third delivery channel forming portion is narrower than the width of the downstream opening portion of the first toner delivery channel 108 formed by the first delivery channel forming component. Furthermore, in this case, the third toner delivery channel becomes a toner delivery channel without an internal delivery unit (e.g., a screw). Therefore, the length of the third toner delivery channel is such that the toner within the third toner delivery channel can be delivered to the downstream second toner delivery channel 109 by the rotational delivery force of the first screw arranged in the upstream first toner delivery channel 108.

[0186] In the toner delivery apparatus of the above embodiments, a delivery channel is described where the upstream side is a horizontal delivery channel and the downstream side is a vertical upward delivery channel. However, the construction of the delivery channel is not limited to this. In other words, the present invention can be applied to delivery channels in which the influence of gravity on toner delivery increases in the direction toward the downstream side of the delivery channel, as in the delivery channels of the various embodiments. For example, in the construction of the various embodiments, the first toner delivery channel 108 (rotation shaft 105A of the upstream screw 105) may have a small angle (elevation angle) relative to the horizontal plane. In this case, even if the second toner delivery channel 109 (rotation shaft 114A of the downstream screw 114) has a small angle relative to the vertical direction, a delivery channel construction in which the influence of gravity is stronger on the downstream side can still be established, as long as the angle (elevation angle) of the second toner delivery channel 109 relative to the horizontal plane is greater than the angle of the first toner delivery channel 108 (rotation shaft 105A of the upstream screw 105). Similarly, the present invention can be appropriately applied in this configuration, and similar effects to those in the embodiments can be obtained. The change in the angle of the conveying channel relative to the horizontal plane is not limited to a one-time change along the direction from the horizontal line to the vertical line as described in the embodiments, but can be gradually changed two or more times, or can be changed into a curve. The present invention can also be appropriately applied in this case as well.

[0187] The toner delivery device of the present invention can be applied not only to the delivery of new toner (as described in the above embodiments), but also to the delivery of waste toner, such as untransferred toner. In this case, particles such as paper scraps generated from the recording material may be included in the delivery target particles, but the primary delivery target remains the waste toner. Therefore, the delivery target particles can be efficiently delivered using the same construction as in the above embodiments.

[0188] Although the invention has been described with reference to exemplary embodiments, it should be understood that the invention is not limited to the disclosed exemplary embodiments. The scope of the appended claims should be given the broadest interpretation to cover all such modifications and equivalent structures and functions.

Claims

1. A toner delivery device for image formation, the toner delivery device comprising: A first conveying section configured to convey toner has a first screw and a first conveying channel forming member. The first screw includes a first rotating shaft and a first blade portion and is rotatable. The first conveying channel forming member forms a first conveying space by covering the first screw. A second conveying section is configured to convey the toner conveyed by the first conveying section upwards. The second conveying section has a second screw and a second conveying channel forming member. The second screw includes a second rotating shaft and a second blade portion and is rotatable. The second conveying channel forming member forms a second conveying space by covering the second screw. The first conveying space and the second conveying space are connected by a connection port. The protruding portion protrudes from the region of the first conveying channel forming component located above the first rotating shaft toward the axis of rotation of the first rotating shaft. The protruding portion is located at the connection port; and When viewed along the axis of rotation of the first rotation axis, the protruding portion overlaps with the first blade portion.

2. The toner delivery device according to claim 1, in, The first conveying channel forming component includes a supply port disposed on the upper surface of the first conveying section, through which the toner is supplied into the first conveying space.

3. The toner delivery device according to claim 1, in, The protruding portion protrudes in a direction perpendicular to the axis of rotation of the first rotating shaft.

4. The toner delivery device according to claim 1, in, The protruding portion protrudes further toward the rotation axis of the first rotating shaft than the inner wall surface of the first conveying channel forming component in a direction perpendicular to the rotation axis of the first rotating shaft.

5. The toner delivery device according to claim 1, in, The protruding portion includes a surface that is continuous with the inner wall surface of the component forming the second conveying channel.

6. The toner delivery device according to claim 1, in, The connection port is located downstream of the downstream end of the first blade portion in the toner delivery direction of the first screw.

7. The toner delivery device according to claim 1, in, The connection port opens in the direction of the rotation axis of the first rotating shaft.

8. The toner delivery device according to claim 1, in, The axis of rotation of the second rotating shaft extends along the direction of gravity.

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