Toner conveying device and image forming apparatus

Abstract

To reduce generation of an unusual sound while reducing occurrence of toner cross-linking even when an inclined conveyance path extending obliquely downward is installed to communicate with a lower end of a fall conveyance path.SOLUTION: A plurality of flexible sheet members 53A-53C are provided in parallel, so that gaps D1, D2 in a conveyance direction are formed which are larger than a coil pitch H of an inclined conveyance coil 52, at least in a portion from a portion in contact with a projection 43b up to a leading end 53b between the sheet members adjacent to a conveyance direction. The plurality of flexible sheet members 53A-53C are further configured so that the gap D2 between the adjacent sheet members at a position corresponding to an upstream side in the conveyance direction, is larger than the gap D1 between the adjacent sheet members at a position corresponding to a downstream side.SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] This invention relates to a toner conveying device for conveying toners such as waste toner, recycled toner, and new toner, and an image forming apparatus such as a copying machine, a printer, a facsimile machine, or a multifunction machine equipped with the same.

Background Art

[0002] Conventionally, in image forming apparatuses such as copying machines and printers, there has been known a toner conveying device provided with a dropping conveyance path for dropping toner such as waste toner by its own weight, and an inclined conveyance path that communicates with the lower end of the dropping conveyance path and extends obliquely downward (see, for example, Patent Document 1).

[0003] On the other hand, Patent Document 1 discloses a technique of providing a comb-shaped flexible sheet member that sways in conjunction with the rotation of an inclined conveyance coil installed in the inclined conveyance path near the portion where the dropping conveyance path and the inclined conveyance path communicate, so as to prevent crosslinking of the toner.

Summary of the Invention

Problems to be Solved by the Invention

[0004] Although the conventional toner conveying device can sufficiently expect the effect of making it difficult for toner crosslinking to occur near the portion where the dropping conveyance path and the inclined conveyance path communicate, abnormal noise has been generated due to the swaying of the comb-shaped flexible sheet member.

[0005] This invention has been made to solve the above-described problems, and even when an inclined conveyance path extending obliquely downward is installed so as to communicate with the lower end of the dropping conveyance path, it is possible to reduce the generation of abnormal noise while making it difficult for toner crosslinking to occur, and to provide a toner conveying device and an image forming apparatus.

Means for Solving the Problems

[0006] The toner conveyance device in this invention includes a drop conveyance path along which toner drops due to its own weight, an inclined conveyance path that communicates with the lower end of the drop conveyance path and extends obliquely downward, a coiled or screw-shaped conveyance member provided inside the inclined conveyance path and rotating in a predetermined direction to convey the toner obliquely downward, a flexible sheet member provided inside the drop conveyance path such that its tip can contact the conveyance member and that swings in conjunction with the rotation of the conveyance member, and a protrusion that inclines the inner wall surface in a direction away from the rotation center of the conveyance member so that the tip of the flexible sheet member faces the rotation center of the conveyance member. A plurality of the flexible sheet members are provided such that a plurality of the tips are arranged along the conveyance direction of the conveyance member, and a plurality of the protrusions are provided so as to correspond to the plurality of flexible sheet members respectively. The plurality of protrusions are configured such that those located at positions corresponding to the upstream side in the conveyance direction have a higher protrusion height than those located at positions corresponding to the downstream side. The plurality of flexible sheet members are arranged side by side such that a gap in the conveyance direction that is larger than the coil pitch or screw pitch of the conveyance member is formed in at least a portion from the portion contacting the protrusion to the tip between those adjacent to each other in the conveyance direction, and the gap between those adjacent to each other at a position corresponding to the upstream side in the conveyance direction is configured to be larger than the gap between those adjacent to each other at a position corresponding to the downstream side.

Advantages of the Invention

[0007] According to the present invention, even when an inclined conveyance path extending obliquely downward is installed so as to communicate with the lower end of the drop conveyance path, it is possible to provide a toner conveyance device and an image forming apparatus in which the generation of abnormal noise is reduced and the crosslinking of toner is less likely to occur.

Brief Description of the Drawings

[0008]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Figure 11

Embodiments for Carrying Out the Invention

[0009] Hereinafter, embodiments for carrying out this invention will be described in detail with reference to the drawings. In each figure, the same or corresponding parts are denoted by the same reference numerals, and the redundant description thereof will be appropriately simplified or omitted.

[0010] First, with reference to FIG. 1, the overall configuration and operation of the image forming apparatus 1 will be described. In FIG. 1, reference numeral 1 denotes a color copying machine as an image forming apparatus, 3 denotes a document conveyance unit that conveys a document to a document reading unit 4, 4 denotes a document reading unit that reads image information of a document, and 6 denotes a writing unit (exposure unit) that emits a laser beam based on input image information. Further, 7 denotes a paper feeding device that stores a sheet P such as paper, 10Y, 10M, 10C, and 10BK denote process cartridges as image forming units corresponding to respective colors (yellow, magenta, cyan, black), 17 denotes an intermediate transfer belt (image carrier) onto which toner images of a plurality of colors are superposed and transferred, and 18 denotes a secondary transfer roller that transfers the toner image formed on the intermediate transfer belt 17 to the sheet P. Also, 20 denotes a fixing device that fixes an unfixed image on the sheet P, 28 denotes a toner container for supplying toner of each color to a developing device of each of the process cartridges 10Y, 10M, 10C, and 10BK, and 30 denotes a waste toner collection container for collecting waste toner.

[0011] Here, each of the process cartridges 10Y, 10M, 10C, and 10BK (image forming units) is an integrated unit of a photosensitive drum 11 as an image carrier, a charging device 12, a developing device 13, and a cleaning device 15 (see FIG. 2). And each of the process cartridges 10Y, 10M, 10C, and 10BK is replaced with a new one when its life is reached. On the photosensitive drum 11 (image carrier) in each of the process cartridges 10Y, 10M, 10C, and 10BK, toner images of respective colors (yellow, magenta, cyan, black) are formed.

[0012] Hereinafter, the operation during normal color image formation in the image forming apparatus will be described. First, the document is conveyed from the document table by the conveyance roller of the document conveyance unit 3 and placed on the contact glass of the document reading unit 4. Then, in the document reading unit 4, the image information of the document placed on the contact glass is optically read. Then, the image information of each color of yellow, magenta, cyan, and black is transmitted to the writing unit 6. Then, from the writing unit 6, laser light (exposure light) based on the image information of each color is irradiated onto the photosensitive drums 11 of the corresponding process cartridges 10Y, 10M, 10C, and 10BK, respectively.

[0013] On the other hand, the four photosensitive drums 11 are each rotating in the clockwise direction in FIGS. 1 and 2. Then, referring to FIG. 2, first, the surface of the photosensitive drum 11 is uniformly charged at the position facing the charging device 12 (charging roller) (this is the charging process). In this way, a charging potential is formed on the photosensitive drum 11. After that, the surface of the charged photosensitive drum 11 reaches the irradiation position of each laser light. In the writing unit 6, laser light L corresponding to the image signal is emitted from the light source for each color. The laser light L is incident on the polygon mirror and reflected, and then passes through a plurality of lenses. The laser light after passing through the plurality of lenses will pass through different optical paths for each color component of yellow, magenta, cyan, and black (this is the exposure process).

[0014] The laser light corresponding to the yellow component is irradiated onto the surface of the photosensitive drum 11 of the first process cartridge 10Y from the left side of the paper surface. In this way, an electrostatic latent image corresponding to the yellow component is formed on the photosensitive drum 11 after being charged by the charging roller 12a. Similarly, the laser light of the cyan component is irradiated onto the surface of the photosensitive drum 11 of the second process cartridge 10C from the left of the paper surface, and an electrostatic latent image of the cyan component is formed. The laser light corresponding to the magenta component is irradiated onto the surface of the photosensitive drum 11 of the third process cartridge 10M from the left of the paper surface, and an electrostatic latent image corresponding to the magenta component is formed. The laser light of the black component is irradiated onto the surface of the photosensitive drum 11 of the fourth process cartridge 10BK from the left of the paper surface, and an electrostatic latent image of the black component is formed.

[0015] After that, the surfaces of the photosensitive drums 11 on which electrostatic latent images of respective colors are formed reach the positions facing the developing devices 13 (see FIG. 2), respectively. Then, toners of respective colors are supplied onto the photosensitive drums 11 from the respective developing devices 13, and the latent images on the photosensitive drums 11 are developed (this is the developing process). After that, the surfaces of the photosensitive drums 11 after the developing process reach the positions facing the intermediate transfer belt 17 (intermediate transfer member) as the image carrier, respectively. Here, primary transfer rollers 14 are installed at the respective facing positions so as to abut on the inner peripheral surfaces of the intermediate transfer belt 17. Then, at the positions of the primary transfer rollers 14, the toner images of respective colors formed on the photosensitive drums 11 are sequentially transferred and overlapped onto the intermediate transfer belt 17 (this is the primary transfer process).

[0016] Then, the surfaces of the photosensitive drums 11 after the primary transfer process reach the positions facing the cleaning devices 15 (see FIG. 2), respectively. And the untransferred toner remaining on the photosensitive drums 11 is collected by the cleaning devices 15 (this is the cleaning process). After that, the surfaces of the photosensitive drums 11 pass through the position of the charge eliminating device, and a series of image forming processes on the photosensitive drums 11 are completed.

[0017] On the other hand, the surface of the intermediate transfer belt 17 onto which the images of respective colors on the photosensitive drum 11 are transferred and overlapped travels in the direction of the arrow in FIG. 1 and reaches the position of the secondary transfer roller 18. Then, at the position of the secondary transfer roller 18, the full-color image on the intermediate transfer belt 17 is secondarily transferred onto the sheet P (this is the secondary transfer process). After that, the surface of the intermediate transfer belt 17 reaches the position of the intermediate transfer belt cleaning device 9 (cleaning device). And the untransferred toner on the intermediate transfer belt 17 is collected by the intermediate transfer belt cleaning device 9, and a series of transfer processes on the intermediate transfer belt 17 are completed.

[0018] Here, the sheet P at the position of the secondary transfer roller 18 is conveyed via a paper feed device 7, a conveyance guide, a registration roller 19, and the like. Specifically, the sheet P fed from the sheet feeding device 7 that stores the sheet P is guided to the registration roller 19 after passing through the conveyance guide by the sheet feeding roller 8. The sheet P that has reached the registration roller 19 is conveyed toward the position of the secondary transfer roller 18 in synchronization with the toner image on the intermediate transfer belt 17.

[0019] After that, the sheet P onto which the full-color image has been transferred is guided to the fixing device 20. In the fixing device 20, the color image is fixed onto the sheet P at the nip between the fixing roller and the pressure roller. Then, the sheet P after the fixing process is discharged outside the apparatus main body 1 as an output image by the paper discharge roller 29, and then stacked on the paper discharge unit 5, completing a series of image forming processes.

[0020] Next, with reference to FIG. 2, the image forming section of the image forming apparatus will be described in detail. FIG. 2 is a configuration diagram showing the process cartridge 10BK for black. Since the other three process cartridges 10Y, 10M, and 10C are configured substantially the same as the process cartridge 10BK for black, except that the color of the toner used in the image forming process is different, their illustration and description are omitted.

[0021] As shown in FIG. 2, the process cartridge 10BK integrally houses in a case a photosensitive drum 11 as an image carrier, a charging device 12 that charges the photosensitive drum 11, a developing device 13 that develops the electrostatic latent image formed on the photosensitive drum 11, and a cleaning device 15 that recovers the untransferred toner on the photosensitive drum 11.

[0022] Here, the photosensitive drum 11 is a negatively chargeable organic photosensitive member, which is provided with a photosensitive layer and the like on a drum-shaped conductive support. The charging device 12 is a charging roller formed by coating the outer periphery of a conductive core bar with a medium-resistance elastic layer. A predetermined voltage is applied to this charging device 12 (charging roller) from a power supply unit, thereby uniformly charging the surface of the opposing photosensitive drum 11.

[0023] The developing device 13 mainly includes a developing roller 13a facing the photosensitive drum 11, a first conveying screw 13b1 facing the developing roller 13a, a second conveying screw 13b2 facing the first conveying screw 13b1 via a partition member, and a doctor blade 13c facing the developing roller 13a. The developing roller 13a is composed of a magnet fixedly installed inside and forming magnetic poles on the roller circumferential surface, and a sleeve rotating around the magnet. A plurality of magnetic poles are formed on the developing roller 13a (sleeve) by the magnet, and the developer is carried on the developing roller 13a. The developing device 13 contains a two-component developer composed of carrier and toner.

[0024] The cleaning device 15 is provided with a cleaning blade 15a that contacts the photosensitive drum 11, a conveying screw 15b (conveying pipe 16) that conveys the untransferred toner collected in the cleaning device 15 as waste toner toward the waste toner conveying device 40 (see FIG. 3), and the like. The cleaning blade 15a is made of a rubber material such as urethane rubber and contacts the surface of the photosensitive drum 11 at a predetermined angle and pressure. Thereby, deposits such as untransferred toner adhering to the photosensitive drum 11 are mechanically scraped off and collected in the cleaning device 15. Then, the untransferred toner collected in the cleaning device 15 is conveyed via the conveying pipe 16 (inside which the conveying screw 15b is installed) to the waste toner conveying device 40 as a toner conveying device (see FIG. 3), and further conveyed by the waste toner conveying device 40 to the waste toner collection container 30 and collected inside the waste toner collection container 30 as waste toner. Similarly, referring to FIG. 1, an intermediate transfer belt cleaning device 9 as a cleaning device also includes a cleaning blade that contacts the intermediate transfer belt 17, a conveying screw (conveying pipe 16) that conveys the untransferred toner collected in the intermediate transfer belt cleaning device 9 as waste toner toward a waste toner conveying device 40 (see FIG. 3), and the like. The untransferred toner collected in the intermediate transfer belt cleaning device 9 is conveyed through the conveying pipe 16 (inside which a conveying screw is provided) to the waste toner conveying device 40 as a toner conveying device (see FIG. 3), and further conveyed by the waste toner conveying device 40 to the waste toner collection container 30, and collected inside the waste toner collection container 30 as waste toner. The waste toner conveying device 40 will be described in more detail later. In addition, as deposits adhering to the photosensitive drum 11 and the intermediate transfer belt 17, in addition to the untransferred toner, there are paper dust generated from the sheet P (paper), discharge products generated on the photosensitive drum 11 during discharge by the charging device 12, additives added to the toner, and the like. In the present application, these are collectively referred to as "untransferred toner".

[0025] In FIG. 2, the imaging process described above will be further described in detail. The developing roller 13a is rotating in the direction of the arrow (counterclockwise) in FIG. 2. The developer in the developing device 13 is circulated in the longitudinal direction (perpendicular to the plane of FIG. 2) while being agitated and mixed with the toner replenished from the toner container 28 by a toner replenishing unit by the rotation of the first conveying screw 13b1 and the second conveying screw 13b2 arranged with a partition member interposed therebetween.

[0026] Then, the toner triboelectrically charged and adsorbed to the carrier is carried on the developing roller 13a together with the carrier. The developer carried on the developing roller 13a then reaches the position of the doctor blade 13c. And the developer on the developing roller 13a is adjusted to an appropriate amount at the position of the doctor blade 13c and then reaches the facing position with the photosensitive drum 11 (which is the developing area). Thereafter, in the development area, the toner in the developer adheres to the electrostatic latent image formed on the surface of the photoreceptor drum 11. Specifically, the toner adheres to the latent image (a toner image is formed) due to the electric field formed by the potential difference (development potential) between the latent image potential (exposure potential) of the image portion irradiated with the laser beam L and the development bias applied to the development roller 13a. Thereafter, most of the toner adhering to the photoreceptor drum 11 in the developing process is transferred onto the intermediate transfer belt 17. Then, the untransferred toner remaining on the photoreceptor drum 11 is collected into the cleaning device 15 by the cleaning blade 15a.

[0027] Hereinafter, the waste toner conveyance device 40 as a toner conveyance device, which is characteristic in the image forming apparatus 1 according to the present embodiment, will be described in detail. Referring to FIG. 3, the waste toner conveyance device 40 as a toner conveyance device discharges waste toner as the toner (developer) collected by the plurality of cleaning devices 15 and the intermediate transfer belt cleaning device 9 and flowing in from the inlet A through the conveyance pipe 16, toward the waste toner collection container 30 from the outlet B. Specifically, in the waste toner conveyance device 40, the waste toner (toner) is conveyed in the direction of the black arrow in FIG. 3. The waste toner collection container 30 is detachably (replaceably) installed with respect to the image forming apparatus main body 1, and when the waste toner collection container 30 is attached to the image forming apparatus main body 1, it is connected to be communicable with the waste toner conveyance device 40 (the inclined conveyance path 42). Then, the waste toner conveyed by the waste toner conveyance device 40 is collected inside the waste toner collection container 30.

[0028] Here, as shown in FIGS. 3 and 4, the waste toner conveyance device 40 (toner conveyance device) is provided with a horizontal conveyance path 41, a dropping conveyance path 43, and an inclined conveyance path 42 along the conveyance direction of the waste toner indicated by the black arrow. Further, an inlet A is provided at the upper part of the sky on the upstream side in the conveyance direction of the horizontal conveyance path 41, and an outlet B is provided at the bottom on the downstream side in the conveyance direction of the inclined conveyance path 42. Thus, the waste toner conveying device 40 is configured by combining a plurality of conveying paths extending in different directions without providing a conveying path directly connecting the inlet A and the outlet B because of layout constraints in the image forming apparatus main body 1. Specifically, in the present embodiment, as shown in FIG. 3, a horizontal conveying path 41, a dropping conveying path 43, and an inclined conveying path 42 are provided so as to avoid the writing unit 6 located above the waste toner collection container 30 inside the image forming apparatus 1.

[0029] The dropping conveying path 43 is a conveying path along which waste toner (toner) drops by its own weight, and is formed to extend in a substantially vertical direction in the present embodiment. Further, the dropping conveying path 43 in the present embodiment is formed such that its cross section in the horizontal direction is rectangular. Here, a flexible sheet member 53 (see FIGS. 3 to 5, etc.) for preventing crosslinking of toner in the conveying path is provided in the dropping conveying path 43, which will be described in detail later. In the present embodiment, the dropping conveying path 43 is formed to extend in a substantially vertical direction. However, the dropping conveying path 43 may be any path as long as it allows the waste toner to drop by its own weight. For example, it may be a path that allows the toner to slide down on an inclined surface inclined with respect to the vertical direction and then drop by its own weight.

[0030] The inclined conveying path 42 communicates with the lower end of the dropping conveying path 43 (the portion surrounded by the broken line in FIG. 3) and extends obliquely downward (the direction from the upper right to the lower left in FIG. 3). That is, the inclined conveying path 42 is arranged to intersect the dropping conveying path 43 at a predetermined inclination angle. In the present embodiment, the inclined conveying path 42 is formed in a substantially cylindrical shape.

[0031] And, in the inclined conveyance path 42, an inclined conveyance coil 52 is provided as a coiled conveyance member (first conveyance member) that rotates in a predetermined direction and conveys waste toner (toner) obliquely downward. Referring to FIGS. 3, 4, etc., the inclined conveyance coil 52 as a conveyance member is made of a metal material, and the upstream end portion of the coil portion spirally wound in a predetermined direction (the upper right end portion in FIG. 3.) is joined to the shaft portion by welding or the like, and a bevel gear 62 is installed on the shaft portion. This bevel gear 62 meshes with the bevel gear 61 of the horizontal conveyance coil 51 described later, and as the horizontal conveyance coil 51 is rotationally driven by a motor (not shown), the inclined conveyance coil 52 rotates about the rotation center X2 in the direction of the arrows in FIGS. 3 and 4. Note that when the inclined conveyance coil 52 rotates in the direction of the arrow in FIG. 4 (counterclockwise), the flexible sheet member 53 (53A to 53C) described later is lifted in a direction away from the protrusion 43b (43b1 to 43b3) due to contact with the inclined conveyance coil 52. Therefore, the flexible sheet member 53 (53A to 53G) described later swings efficiently.

[0032] On the other hand, the horizontal conveyance path 41 communicates with the upper end of the dropping conveyance path 43 and extends in the horizontal direction (the direction from the left to the right in FIG. 3). That is, the horizontal conveyance path 41 is arranged so as to intersect the dropping conveyance path 43 in the horizontal direction. In the present embodiment, the horizontal conveyance path 41 is formed in a substantially cylindrical shape.

[0033] And, in the horizontal conveyance path 41, a horizontal conveyance coil 51 is provided as a coiled second conveyance member that rotates in a predetermined direction and conveys waste toner (toner) in the horizontal direction. Referring to FIGS. 3, 6, etc., the horizontal conveyance coil 51 as the second conveyance member is made of a metal material, and the upstream end portion of the coil portion spirally wound in a predetermined direction (the right end portion in FIG. 3.) is joined to the shaft portion by welding or the like, and a bevel gear 61 is installed on the shaft portion. And the horizontal conveyance coil 51 rotates about the rotation center X1 in the direction of the arrows in FIGS. 3 and 4 by being driven by a motor (not shown). Note that as the horizontal conveyance coil 51 rotates in the direction of the arrow in Fig. 4 (clockwise), the waste toner in the horizontal conveyance path 41 conveyed by the horizontal conveyance coil 51 will fall by its own weight along the side of the flexible sheet member 53 (or the inner wall surface 43a), which will be described later, within the dropping conveyance path 43.

[0034] Here, referring to Fig. 3, Fig. 4, etc., a flexible sheet member 53 is provided within the dropping conveyance path 43 in the waste toner conveyance device 40 (toner conveyance device) in the present embodiment such that the tip portion 53b (in the present embodiment, it is the bent portion of the flexible sheet member 53) can contact the inclined conveyance coil 52 (conveyance member). This flexible sheet member 53 swings in conjunction with the rotation of the inclined conveyance coil 52 (conveyance member) as shown by the double arrows in Fig. 4. That is, when the inclined conveyance coil 52 rotates together with the horizontal conveyance coil 51 with the operation of the waste toner conveyance device 40, the tip portion 53b (the lower end portion that becomes the free end) of the flexible sheet member 53 repeatedly contacts and separates from the coil portion of the inclined conveyance coil 52, and the flexible sheet member 53 swings. In particular, the tip portion 53b of the flexible sheet member 53 swings greatly at the communication portion between the dropping conveyance path 43 and the inclined conveyance path 42.

[0035] In the present embodiment, since the flexible sheet member 53 configured as such is provided, even when the inclined conveyance path 42 extending obliquely downward is installed to communicate with the lower end of the dropping conveyance path 43, even if toner is likely to condense in the vicinity of the portion where the dropping conveyance path 43 and the inclined conveyance path 42 communicate, the toner is scraped off by the flexible sheet member 53, making it difficult for toner bridging to occur. Therefore, it is also difficult for conveyance failure of the toner due to toner bridging to occur. In particular, since waste toner is more likely to cause toner bridging compared to new toner (fresh toner), the configuration of the present invention is useful. Also, as described above, in the dropping conveyance path 43, the waste toner drops by its own weight along the flexible sheet member 53, so it is configured to easily adhere to the flexible sheet member 53. However, since the flexible sheet member 53 itself is actively shaken, toner adhesion to such a flexible sheet member 53 is less likely to occur. Furthermore, the flexible sheet member 53 is a relatively inexpensive and lightweight member, and is configured to shake by repeatedly coming into contact with and separating from the inclined conveyance coil 52 without providing a dedicated drive source for causing the shaking. Therefore, the apparatus has a relatively simple configuration.

[0036] In the present embodiment, the flexible sheet member 53 is made of a material such as PET (polyurethane terephthalate), and is formed so that the sheet thickness is 0.2 mm or more (in this embodiment, it is about 0.3 to 0.8 mm). This is because when the sheet thickness is less than 0.05 mm, the function of breaking up the toner by shaking becomes low, and when the sheet thickness is 0.05 mm or more, the function of breaking up the toner during shaking increases as the thickness increases. However, when the sheet thickness is 0.2 mm or more, as will be described later with reference to FIG. 6, when a plurality of flexible sheet members are arranged side by side without gaps, the sound when the flexible sheet members interfere with each other and bounce off becomes large (abnormal noise occurs). In this embodiment, even when the sheet thickness is set to 0.2 mm or more, a plurality of flexible sheet members 53A to 53C are arranged side by side with gaps D1 and D2 so that such abnormal noise does not occur, which will be described in detail later.

[0037] Here, referring to FIGS. 3 to 5 and the like, in the present embodiment, the flexible sheet member 53 (53A to 53C) extends in the vertical direction, and the upper end portion 53a is fixed to the inner wall surface 43a of the dropping conveyance path 43 as a fixed end so that the tip portion 53b as the lower end portion becomes a free end. Specifically, in this embodiment, the upper end portion 53a of the flexible sheet member 53 (53A to 53C) is adhered to the inner wall surface 43a by a double-sided tape (supported as a cantilever). Then, as shown in FIG. 3, when viewed from the direction facing the inner wall surface 43a of the dropping conveyance path 43, the inclined conveyance path 42 extends obliquely downward at a predetermined inclination angle θ.

[0038] And in the present embodiment, as shown in FIGS. 4 (and FIG. 5), a plurality of protrusions 43b (43b1 to 43b3) are provided on the inner wall surface 43a of the dropping conveyance path 43. These protrusions 43b (43b1 to 43b3) are for inclining the portion excluding the upper end portion 53a (which is a fixed end fixed to the inner wall surface 43a of the dropping conveyance path 43) in a direction away from the inner wall surface 43a so that the tip portion 53b, which is the free end of the flexible sheet member 53 (53A to 53C), faces the rotation center X2 of the inclined conveyance coil 52 (conveyance member). Specifically, as shown in FIG. 4, the protrusion 43b (43b1 to 43b3) has an inclined surface that inclines in a direction away from the inner wall surface 43a from the upper part to the lower part. And when it is assumed that the protrusion 43b does not contact the inclined conveyance coil 52 (or when it is assumed that there is no inclined conveyance coil 52), the flexible sheet member 53 inclines along the inclined surface of the protrusion 43b, and its tip portion 53b faces the rotation center X2 of the inclined conveyance coil 52.

[0039] More specifically, as shown in FIG. 4, the flexible sheet member 53 (53A to 53C) is provided with an upper end portion 53a (fixed end), a belly portion 53c, and a tip portion 53b (lower end portion). The belly portion 53c extends vertically downward from the upper end portion 53a when viewed from the direction facing the inner wall surface 43a as shown in FIG. 3. Also, the belly portion 53c extends obliquely downward to the left from the upper end portion 53a when viewed from the side as shown in FIG. 4. In contrast, as shown in FIGS. 3, 5, and 7(B), the tip portion 53b (lower end portion) is bent so as to follow the inclination with respect to the rotation center X2 of the coil of the inclined conveying coil 52 (conveying member) from the lower end of the abdomen 53c. That is, as shown in FIG. 7(B), the inclination angle β of the tip portion 53b with respect to the rotation center X2 is configured to be substantially equal (α≒β) to the inclination angle α of the inclined conveying coil 52 with respect to the rotation center X2 of the coil. Therefore, the tip portion 53b is likely to be in surface contact with the coil of the inclined conveying coil 52, and compared with the structure in which the tip portion 153b is in point contact with the coil like the flexible sheet member 153 shown as a comparative example in FIG. 7(A) (α≠β´), the sound (abnormal sound) when the flexible sheet member 53 is repelled by the inclined conveying coil 52 becomes smaller.

[0040] Here, as shown in FIGS. 3 to 5(A), etc., a plurality of tip portions 53b (in this embodiment, there are three tip portions 53b) of the flexible sheet member 53 are arranged along the conveying direction of the inclined conveying coil 52 (diagonal downward in FIG. 3), and a plurality of flexible sheet members 53A to 53C (in this embodiment, there are three flexible sheet members) are provided. And for the plurality of flexible sheet members 53A to 53C, their upper end portions 53a are at the same height position (near the connecting portion of the horizontal conveying path 41 and the falling conveying path 43) and are adhered to the inner wall surface 43a. Also, referring to FIG. 5 etc., a plurality of protrusions 43b are provided so as to correspond to the plurality of flexible sheet members 53A to 53C respectively.

[0041] Specifically, referring to FIGS. 3, 5, etc., the flexible sheet members 53A to 53C located at positions corresponding to the upstream side in the conveying direction (the direction from the upper right diagonal to the lower left diagonal in FIG. 3) are configured to have a shorter sheet length (the length of the portion excluding the fixed end) than those located at positions corresponding to the downstream side (R1>R2>R3). More specifically, referring to FIG. 5, the sheet lengths of the first flexible sheet member 53A, the second flexible sheet member 53B, and the third flexible sheet member 53C become shorter in this order.

[0042] Further, among the plurality of protrusions 43b, those located at positions corresponding to the upstream side in the conveyance direction (the direction from the upper right diagonal to the lower left diagonal in FIG. 3) are configured to have a higher protrusion height (the height at the lower part, which is the height in the direction away from the inner wall surface 43a) than those located at positions corresponding to the downstream side. Specifically, referring to FIG. 4, the protrusion height of the downstream protrusion 43b shown in FIG. 4(A) is lower than the protrusion height of the middle-stream protrusion 43b shown in FIG. 4(B), and the protrusion height of the middle-stream protrusion 43b shown in FIG. 4(B) is lower than the protrusion height of the upstream protrusion 43b shown in FIG. 4(C). As a result, the inclination angle θ1 of the downstream flexible sheet member 53A shown in FIG. 4(A) is smaller than the inclination angle θ2 of the middle-stream flexible sheet member 53B shown in FIG. 4(B), and the inclination angle θ2 of the middle-stream flexible sheet member 53B shown in FIG. 4(B) is smaller than the inclination angle θ3 of the upstream flexible sheet member 53C shown in FIG. 4(C) (θ1 < θ2 < θ3). The inclination angles θ1 to θ3 described above are the angles formed by the inner wall surface 43a of the dropping conveyance path 43 and the abdomen 53c of the flexible sheet members 53A to 53C when viewed in a cross section orthogonal to the rotation axis of the horizontal conveyance coil 51. By configuring in this way, a plurality of flexible sheet members 53A to 53C with different lengths and having their upper end portions 53a fixed at the same height position will uniformly head toward the rotation center X2 of the inclined conveyance coil 52 that inclines. Therefore, the plurality of flexible sheet members 53A to 53C will smoothly swing in conjunction with the rotation of the inclined conveyance coil 52 respectively, and the toner crosslinking will be efficiently reduced.

[0043] In this embodiment, as shown in FIG. 5(B), the upper end portions 53a (fixed ends) of the plurality of flexible sheet members 53A to 53C can be integrally formed at the same height position. That is, the flexible sheet member 53 can be formed in a comb shape as one member such that it is composed of flexible sheet members 53A to 53C in which portions other than the upper end portion 53a are divided into a plurality. Thus, when the flexible sheet member 53 is formed in a comb shape, compared with the case where a plurality of flexible sheet members 53A to 53C are configured as independent components as shown in FIG. 5(A), the number of components can be reduced and the assemblability to the apparatus can be improved. In this embodiment, the number of the plurality of flexible sheet members 53A to 53C and the number of the plurality of protrusions 43b are three, but these numbers are not limited to this. Also, in the example of FIG. 5(B), a part of the abdomen 53c below the upper end portion 53a of the plurality of flexible sheet members 53A to 53C (the region up to the protrusions 43b1 to 43b3) is also integrated (connected), which will be described in detail later.

[0044] Here, as shown in FIG. 6, in this embodiment, the sheet width W of the tip portion 53b of the flexible sheet member 53 (53A to 53C) is configured to be smaller than the coil pitch H (see FIG. 3) of the inclined conveying coil (conveying member) (W < H). By configuring in this way, the rocking of the flexible sheet member 53 interlocked with the rotation of the inclined conveying coil 52 can be smoothly performed without causing problems such as riding on the coil portion in a twisted state. Therefore, the effect of preventing toner crosslinking is also efficiently exerted.

[0045] Here, referring to FIGS. 3, 5(A), etc., in this embodiment, the plurality of flexible sheet members 53A to 53C are arranged in parallel such that gaps D1, D2 in the conveying direction larger than the coil pitch H (see FIG. 3) of the inclined conveying coil 52 are formed in at least the portions from the contact portions of the adjacent ones in the conveying direction to the tip portion 53b (D1, D2 > H). Also, the plurality of flexible sheet members 53A to 53C are configured such that the gap D2 between the adjacent ones 53B and 53C at the position corresponding to the upstream side in the conveying direction is larger than the gap D1 between the adjacent ones 53A and 53B at the position corresponding to the downstream side (D1 < D2). Specifically, for the gap D1 between the tip 53b of the first flexible sheet member 53A and the tip 53b of the second flexible sheet member 53B, and the gap D2 between the tip 53b of the second flexible sheet member 53B and the tip 53b of the third flexible sheet member 53C, the relationship H < D1 < D2 holds. Also, in this embodiment, for the gap D1' between the abdomen 53c of the first flexible sheet member 53A and the abdomen 53c of the second flexible sheet member 53B, and the gap D2' between the abdomen 53c of the second flexible sheet member 53B and the abdomen 53c of the third flexible sheet member 53C, the relationship H < D1' < D2' also holds.

[0046] In this way, by providing a gap D1 (D2) larger than the coil pitch H between adjacent flexible sheet members 53A and 53B (53B and 53C), as shown in Fig. 6(A), even if the flexible sheet members 53A to 53B are deformed by the shaking due to contact with the inclined conveying coil 52, it becomes difficult for them to contact adjacent flexible sheet members. Therefore, unlike the flexible sheet member 153 shown in Fig. 6(B) as a comparative example (where a plurality of flexible sheet members are arranged side by side in a comb shape without gaps), the flexible sheet members do not interfere with each other, and problems such as the interference of the flexible sheet members being bounced back and generating abnormal sounds are also suppressed. Also, as described above, since the upstream flexible sheet members 53C (53B) have a larger inclination angle θ of the protruding portions 43b1 to 43b3 in contact than the downstream flexible sheet members 53B (53A), the inclination angle of the flexible sheet member 53 is large and the movable region during shaking is also large, making it easier to contact adjacent flexible sheet members. Therefore, in this embodiment, the gap D2 between the upstream flexible sheet members 53B and 53C is set larger than the gap D1 between the downstream flexible sheet members 53A and 53B so that adjacent flexible sheet members do not contact each other even if the movable region (shaking range) is large.

[0047] Note that the effect of providing the above-described gaps D1 and D2 (the effect of preventing the generation of abnormal noise by preventing adjacent flexible sheet members from contacting each other) is sufficient if the relationship of H < D1 < D2 (H < D1' < D2') is established in the gaps from the portions contacting the protrusions 43b1 to 43b3 to the tip portions 53b in the flexible sheet members 53A to 53C. Therefore, for example, even if the abdominal portion 53c of the flexible sheet member 53 shown in FIG. 5(B), which is integrally connected from the upper end portion 53a to the portion contacting the protrusions 43b1 to 43b3, the effects of the same gaps D1 and D2 as those in FIG. 5(A) can be obtained.

[0048] <Modification Example 1> In the waste toner conveying device 40 (toner conveying device) in Modification Example 1 shown in FIG. 8(A), the protrusion 43b is formed of an elastic material such as a foamed material like foamed polyurethane (sponge material) or a rubber material. Thereby, when the flexible sheet member 53 that swings due to contact with the inclined conveying coil 52 is displaced from a state of being separated from the protrusion 43b (a state located at the position shown by the broken line) to a state of abutting against the protrusion 43b (a state located at the position shown by the solid line), the impact force on the protrusion 43b can be attenuated. Therefore, it is possible to make it difficult for abnormal noise to occur when the flexible sheet member 53 collides with the protrusion 43b. In particular, when the protrusion 43b is formed of a rubber material, it becomes easier to ensure the accuracy of the protrusion height of the protrusion 43b compared to the case where it is formed of a foamed material. On the other hand, the protrusion 43b in FIG. 8(B) is configured to always contact the flexible sheet member 53 and elastically deform in conjunction with the swing of the flexible sheet member 53. That is, the protrusion 43b shown in FIG. 8(B) is in an extended state when the flexible sheet member 53 is located at a position separated from the protrusion 43b (the position shown by the broken line), and is in a contracted state when the flexible sheet member 53 is located at a position contacting the protrusion 43b (the position shown by the solid line). By configuring it in this way, the vibration during the rocking of the flexible sheet member 53 is reduced, so that it is possible to make it difficult for abnormal noise to occur due to the flexible sheet member 53 being struck by the protrusion 43b.

[0049] <Modification Example 2> As shown in FIG. 9, in the waste toner conveying device 40 (toner conveying device) in Modification Example 2, the plurality of protrusions 43b1 to 43b3 are formed of foamed polyurethane (sponge material) which is a foamed material, and those located at positions corresponding to the upstream side in the conveying direction are configured to have a higher foaming density than those located at positions corresponding to the downstream side. Specifically, the foaming density of the first protrusion 43b1 is set to be lower than the foaming density of the second protrusion 43b2, and the foaming density of the second protrusion 43b2 is set to be lower than the foaming density of the 32nd protrusion 43b3. Note that the "foaming density" of the foamed material is the total volume of bubbles contained per unit volume. As described above, the flexible sheet member 53C (53B) on the upstream side has a larger movable range during rocking than the flexible sheet member 53B (53A) on the downstream side, so the impact when colliding with the protrusion 43b also becomes larger. On the other hand, in Modification Example 2, since the foaming density of the protrusion 43b3 (43b2) with which the flexible sheet member 53C (53B) on the upstream side collides is set larger than the foaming density of the protrusion 43b2 (43b1) with which the flexible sheet member 53B (53A) on the downstream side collides, the impact during the above-mentioned impact can be mitigated (the generation of abnormal noise due to impact can be reduced in any part regardless of the magnitude of the impact force).

[0050] <Modification Example 3> As shown in FIG. 10, in the waste toner conveying device 40 (toner conveying device) in Modification Example 3, the plurality of flexible sheet members 53A to 53C are configured such that those located at positions corresponding to the upstream side in the conveying direction have a thinner sheet thickness t1 to t3 than those located at positions corresponding to the downstream side. Specifically, as shown in Fig. 10(A), the sheet thickness t1 of the downstream flexible sheet member 53A is thicker than the sheet thickness t2 of the middle - stream flexible sheet member 53B shown in Fig. 10(B), and the sheet thickness t2 of the middle - stream flexible sheet member 53B shown in Fig. 10(B) is thicker than the sheet thickness t3 of the upstream flexible sheet member 53C shown in Fig. 10(C) (t1 > t2 > t3). The reason for this configuration is that the downstream flexible sheet member 53A (53B) has a longer sheet length compared to the upstream flexible sheet member 53B (53C). If they have the same sheet thickness, the repulsive force when bounced by the inclined conveying coil 52 will be small, and the performance of preventing toner bridging may be reduced. Also, as described above, the upstream flexible sheet member 53C (53B) has a larger movable range during shaking compared to the downstream flexible sheet member 53B (53A), so the impact when colliding with the protrusion 43b also becomes larger. In contrast, in Modification 3, the sheet thickness t3 (t2) of the upstream flexible sheet member 53C (53B) is set thinner than the sheet thickness t2 (t1) of the downstream flexible sheet member 53B (53A). Therefore, the impact during the above - mentioned impact can be reduced (the impact force becomes uniform in any part, and the generation of abnormal noise can be reduced). In Modification 3, the above - mentioned effects are achieved by providing differences in the sheet thicknesses t1 - t3 of the plurality of flexible sheet members 53A - 53C themselves. On the other hand, in the plurality of flexible sheet members 53A - 53C, by preparing flexible sheet members 53A - 53 with a constant thickness and material and providing differences in the number of laminated sheets for each, differences in thickness t1 - t3 can be created, and the above - mentioned effects can also be achieved.

[0051] <Modification 4> As shown in Fig. 11(A), the tip portion 53b of the flexible sheet member 53 (53A - 53C) in Modification 4 is formed in a straight shape from the abdomen without bending from the abdomen. Furthermore, the flexible sheet member 53 (53A to 53C) shown in FIG. 11(B) is provided with a taper (the tip is diagonally cut) at its straight tip portion 53b along the rotation center X2 of the inclined conveyance coil 52 that is inclined. When configured in this way, as described above with reference to FIG. 5, compared to the flexible sheet member 53 formed such that the tip portion 53b bends from the abdomen 53c, when the flexible sheet member 53 rocks in conjunction with the rotation of the inclined conveyance coil 52, although a problem of riding on the coil portion in a twisted state is likely to occur, since the flexible sheet member 53 will rock to some extent, toner crosslinking is reduced to some extent. Also, since appropriate gaps D1 and D2 are provided between adjacent ones of the plurality of flexible sheet members 53A to 53C, generation of abnormal noise can also be reduced.

[0052] As described above, the waste toner conveying device 40 (toner conveying device) in the present embodiment includes a dropping conveyance path 43 along which the toner drops by its own weight, an inclined conveyance path 42 that communicates with the lower end of the dropping conveyance path 43 and extends obliquely downward, and a coiled (or screw-shaped) inclined conveyance coil 52 (conveying member) that is provided inside the inclined conveyance path 42 and rotates in a predetermined direction to convey the toner obliquely downward. Further, a flexible sheet member 53 that swings in conjunction with the rotation of the inclined conveyance coil 52 is provided inside the dropping conveyance path 43 such that the tip portion 53b can contact the inclined conveyance coil 52. In addition, a protrusion 43b is provided to incline the tip portion 53b of the flexible sheet member 53 away from the inner wall surface 43a so as to face the rotation center X2 of the conveying member. A plurality of flexible sheet members 53A to 53C are provided such that a plurality of tip portions 53b are arranged along the conveyance direction of the inclined conveyance coil 52, and a plurality of protrusions 43b1 to 43c are provided to correspond to the plurality of flexible sheet members 53A to 53C, respectively. Further, the plurality of protrusions 43b1 to 43b3 are configured such that the protrusion height is higher for those located at positions corresponding to the upstream side in the conveyance direction than for those located at positions corresponding to the downstream side. The plurality of flexible sheet members 53A to 53C are arranged side by side such that gaps D1 and D2 in the conveyance direction, which are larger than the coil pitch H of the inclined conveyance coil 52, are formed in at least the portion from the portion in contact with the protrusion 43b to the tip portion 53b of those adjacent to each other in the conveyance direction. Further, the plurality of flexible sheet members 53A to 53C are configured such that the gap D2 between those adjacent to each other at a position corresponding to the upstream side in the conveyance direction is larger than the gap D1 between those adjacent to each other at a position corresponding to the downstream side. Thereby, even when the inclined conveyance path 42 extending obliquely downward is installed to communicate with the lower end of the dropping conveyance path 43, generation of abnormal noise is reduced and bridging of the toner is less likely to occur.

[0053] In addition, in the present embodiment, the present invention is applied to a waste toner conveying device 40 (toner conveying device) that conveys the untransferred toner collected by the cleaning device 15 or the intermediate transfer belt cleaning device 9 as waste toner toward the waste toner collection container 30. However, the application of the present invention is not limited to this. For example, the present invention can naturally be applied to a waste toner conveying device 40 in which only the untransferred toner collected by the cleaning device for the photosensitive drum is conveyed as waste toner toward the waste toner collection container 30. Also, in the present embodiment, the present invention is applied to a waste toner conveying device 40 (toner conveying device) that conveys waste toner as toner. However, the application of the present invention is not limited to this. For example, a toner conveying device that conveys the untransferred toner collected by the cleaning device 15 as recycled toner toward the developing device 13, or a toner conveying device that conveys waste toner (including a two-component developer composed of toner and carrier, etc.) discharged from the developing device toward the waste developer collection container, or a toner conveying device that conveys new toner or a two-component developer toward the developing device, etc. The present invention can also be applied. Also, in the present embodiment, the present invention is applied to a waste toner conveying device 40 (toner conveying device) provided with a horizontal conveying path 41. However, the present invention can also be applied to a toner conveying device composed of a dropping conveying path 43 and an inclined conveying path 42 without a horizontal conveying path 41, or a toner conveying device provided with another conveying path (for example, an inclined conveying path) instead of the horizontal conveying path 41. And in such cases as well, the same effects as those of the present embodiment can be obtained.

[0054] Also, in the present embodiment, an inclined conveying coil 52 (coil-shaped conveying member) is installed on the inclined conveying path 42. However, instead, an inclined conveying screw (screw-shaped conveying member) can also be installed. Specifically, as the inclined conveying screw, one in which a screw portion is spirally wound around a shaft portion extending in the rotation axis direction over substantially the entire area of the inclined conveying path with a predetermined screw pitch can be used. In addition, in the present embodiment, the horizontal conveyance coil 51 (coil-shaped second conveyance member) is installed in the horizontal conveyance path 41. Instead, a horizontal conveyance screw (screw-shaped second conveyance member) can also be installed. Specifically, as the horizontal conveyance screw, one in which a screw portion is spirally wound around a shaft portion extending in the rotation axis direction over substantially the entire area of the horizontal conveyance path can be used with a predetermined screw pitch. And even in such cases, the same effects as those of the present embodiment can be obtained.

[0055] It should be noted that the present invention is not limited to the present embodiment, and it is obvious that the present embodiment can be appropriately modified within the scope of the technical idea of the present invention, other than those suggested in the present embodiment. Also, the number, position, shape, etc. of the above-described constituent members are not limited to the present embodiment, and can be set to appropriate numbers, positions, shapes, etc. for implementing the present invention.

Explanation of Reference Numerals

[0056] 1 Image forming apparatus (image forming apparatus main body), 30 Waste toner collection container, 40 Waste toner conveyance device (toner conveyance device), 41 Horizontal conveyance path, 42 Inclined conveyance path, 43 Falling conveyance path, 43a Inner wall surface, 43b, 43b1 - 42b3 Protrusions, 51 Horizontal conveyance coil (second conveyance member), 52 Inclined conveyance coil (conveyance member), 53, 53A - 53C Flexible sheet members, 53a Upper end portion (fixed end), 53b Lower end portion (tip portion, free end), 53c Abdominal portion, A Inlet, B Outlet, D1, D2 Clearances, X1, X2 Rotation centers.

[0057] In addition, the embodiments in the present invention can also be, for example, combinations of Appendices 1 to 10 as follows. (Appendix 1) A falling conveyance path along which toner falls by its own weight, An inclined conveyance path that communicates with the lower end of the falling conveyance path and extends obliquely downward, A coiled or screw-shaped conveyance member that is provided inside the inclined conveyance path and rotates in a predetermined direction to convey the toner obliquely downward, A flexible sheet member that is provided inside the falling conveyance path such that the tip portion can contact the conveyance member and swings in conjunction with the rotation of the conveyance member, A protrusion that inclines in a direction away from the inner wall surface so that the tip portion of the flexible sheet member faces the rotation center of the conveyance member, Comprising A plurality of the flexible sheet members are provided such that a plurality of the tip portions are arranged along the conveyance direction of the conveyance member, and a plurality of the protrusions are provided so as to correspond to the plurality of flexible sheet members respectively, The plurality of protrusions are configured such that those located at positions corresponding to the upstream side in the conveyance direction have a higher protrusion height than those located at positions corresponding to the downstream side, The plurality of flexible sheet members Are arranged in parallel such that a gap in the conveyance direction that is larger than the coil pitch or screw pitch of the conveyance member is formed in at least a portion from the portion in contact with the protrusion to the tip portion between those adjacent to each other in the conveyance direction, A toner conveyance device characterized in that the gap between those adjacent to each other at a position corresponding to the upstream side in the conveyance direction is configured to be larger than the gap between those adjacent to each other at a position corresponding to the downstream side. (Appendix 2) The flexible sheet member An upper end portion as a fixed end fixed to the inner wall surface of the falling conveyance path, An abdomen extending vertically downward from the upper end portion, A tip portion that bends along the inclination of the coil or screw of the conveyance member from the lower end of the abdomen to the rotation center, The toner conveyance device according to appended claim 1, characterized by comprising (Appended claim 3) The toner conveyance device according to appended claim 1 or 2, characterized in that the protruding portion is formed of an elastic material. (Appended claim 4) The toner conveyance device according to appended claim 3, characterized in that the protruding portion is configured to contact the flexible sheet member and elastically deform in conjunction with the rocking of the flexible sheet member. (Appended claim 5) The toner conveyance device according to appended claim 3 or 4, characterized in that the elastic material is a rubber material. (Appended claim 6) The toner conveyance device according to any one of appended claims 1 to 4, characterized in that the plurality of protruding portions are formed of a foaming material, and the foaming density of the protruding portions located at positions corresponding to the upstream side in the conveyance direction is higher than that of the protruding portions located at positions corresponding to the downstream side. (Appended claim 7) The toner conveyance device according to any one of appended claims 1 to 6, characterized in that the plurality of flexible sheet members have a thinner sheet thickness at positions corresponding to the upstream side in the conveyance direction than at positions corresponding to the downstream side. (Appended claim 8) The toner conveyance device according to any one of appended claims 1 to 7, characterized in that the sheet width of the tip portion of the flexible sheet member is smaller than the coil pitch or screw pitch of the conveyance member. (Appended claim 9) A horizontal conveyance path that communicates with the upper end of the dropping conveyance path and extends horizontally, A second conveyance member in the form of a coil or screw that is provided in the horizontal conveyance path and rotates in a predetermined direction to convey toner in the horizontal direction, The toner conveyance device according to any one of appended claims 1 to 8, characterized by comprising (Appended claim 10) An image forming apparatus, characterized by comprising the toner conveyance device according to any one of appended claims 1 to 9.

Prior art documents

Patent Document

[0058]

Patent Document 1

Claims

1. A falling conveyance path through which toner falls by its own weight, an inclined conveyance path that communicates with the lower end of the falling conveyance path and extends obliquely downward, a coiled or screw-shaped conveyance member provided inside the inclined conveyance path and rotating in a predetermined direction to convey the toner obliquely downward, a flexible sheet member provided inside the falling conveyance path such that its tip can contact the conveyance member and that swings in conjunction with the rotation of the conveyance member, a protrusion that inclines in a direction away from the inner wall surface so that the tip of the flexible sheet member faces the center of rotation of the conveyance member, comprising: a plurality of the flexible sheet members are provided such that a plurality of the tips are arranged along the conveyance direction of the conveyance member, and a plurality of the protrusions are provided so as to correspond to the plurality of flexible sheet members respectively, the plurality of protrusions are configured such that those located at positions corresponding to the upstream side in the conveyance direction have a higher protrusion height than those located at positions corresponding to the downstream side, the plurality of flexible sheet members are arranged side by side such that a gap in the conveyance direction that is larger than the coil pitch or screw pitch of the conveyance member is formed in at least a portion from the portion in contact with the protrusion to the tip between those adjacent to each other in the conveyance direction, and a toner conveyance device, characterized in that a gap between those adjacent to each other at a position corresponding to the upstream side in the conveyance direction is configured to be larger than a gap between those adjacent to each other at a position corresponding to the downstream side.

2. The flexible sheet member has an upper end portion as a fixed end fixed to the inner wall surface of the falling conveyance path, a belly portion extending vertically downward from the upper end portion, and a tip portion that bends along an inclination with respect to the center of rotation of the coil or screw of the conveyance member from the lower end of the belly portion, and the toner conveyance device according to claim 1, characterized by comprising the above.

3. The toner conveyance device according to claim 1 or claim 2, characterized in that the protrusion is formed of an elastic material.

4. The toner conveyance device according to claim 3, characterized in that the protrusion is configured to contact the flexible sheet member and elastically deform in conjunction with the swing of the flexible sheet member.

5. The toner conveyance device according to claim 3, characterized in that the elastic material is a rubber material.

6. The plurality of protrusions are formed of a foaming material and are configured such that the density of the foam is higher at positions corresponding to the upstream side in the conveyance direction than at positions corresponding to the downstream side. The toner conveyance device according to claim 1 or claim 2.

7. The plurality of flexible sheet members are characterized in that the sheet thickness is thinner at positions corresponding to the upstream side in the conveyance direction than at positions corresponding to the downstream side. The toner conveyance device according to claim 1 or claim 2.

8. The toner conveyance device according to claim 1 or claim 2, characterized in that the sheet width of the tip portion of the flexible sheet member is smaller than the coil pitch or screw pitch of the conveyance member.

9. A horizontal conveyance path that communicates with the upper end of the drop conveyance path and extends in the horizontal direction, A second conveyance member in the form of a coil or screw that is provided in the horizontal conveyance path and rotates in a predetermined direction to convey toner in the horizontal direction, The toner conveyance device according to claim 1 or claim 2, characterized by comprising the above.

10. An image forming apparatus, characterized by comprising the toner conveyance device according to claim 1 or claim 2.

Images