JP2023134076A - Toner conveying device and cleaning device including the same, and image forming apparatus - Google Patents

Abstract

To provide a toner conveying device that can maintain toner conveying performance, while effectively preventing adhesion of toner.SOLUTION: A toner conveying device comprises a toner conveyance path, a conveying screw, and a scraping member. The conveying screw has a rotation shaft and a spiral blade. The rotation shaft is provided with a pair of support parts on both sides of the toner conveyance path with a center part therebetween with respect to an axial direction. The scraping member has a plurality of flickers arranged side by side at a predetermined interval along the axial direction. Regarding the flickers, the length of flickers other than the center flicker is equal to or less than the length of flickers adjacent to the center with respect to the axial direction, and the length of the center flicker is longer than the length of end flickers.SELECTED DRAWING: Figure 5

Description

The present invention relates to a toner transport device, a cleaning device equipped with the same, and an image forming apparatus.

Image forming apparatuses (copiers, printers, fax machines, etc.) that use a general electrophotographic method first use toner (powdered developer) to form an image on an image carrier (photoreceptor drum) when forming an image. etc.) to form a toner image that visualizes the electrostatic latent image formed thereon. Next, this toner image is transferred onto a recording medium directly or via an intermediate transfer member, and then the toner image is fixed on this recording medium.

A cleaning member is in contact with the image carrier of such an image forming apparatus. The cleaning member removes unnecessary toner (residual toner) remaining on the surface of the image carrier after the image carrier transfers the toner image onto the recording medium or intermediate transfer member. The removed toner is transported as waste toner to a waste toner collection container by a toner transport device. As a result, the outer circumferential surface of the image carrier is cleaned every time the toner image is transferred to a recording medium or an intermediate transfer member, and the toner image can be continuously transferred by the image carrier.

The toner transport device described above includes a toner transport path and a transport screw. The conveyance screw has a rotating shaft and a spiral blade. The rotating shaft is rotatably supported within the toner transport path. The spiral blade is formed on the outer peripheral surface of the rotating shaft. A discharge port is formed in the toner transport path and communicates with a waste toner collection container provided outside the toner transport path. The waste toner removed by the cleaning member falls into the toner conveyance path. The waste toner in the toner conveyance path is conveyed downstream by the conveyance screw, and is discharged into the waste toner collection container through the discharge port.

Here, the external additives contained in the waste toner removed from the surface of the image carrier may become uneven in particle size due to mechanical stress (friction with a cleaning member, friction between external additives, etc.), or There is a risk that paper dust or the like may be mixed into the collected waste toner, resulting in a decrease in the fluidity of the waste toner. Therefore, waste toner is easily solidified. Furthermore, as the melting point of toners has decreased in recent years, the fluidity of toners tends to further decrease in high-temperature environments. For this reason, especially in high-temperature, high-humidity environments, waste toner with reduced fluidity solidifies around the conveying screw (for example, between the spiral blades), resulting in a so-called blocking state, which makes it difficult to convey the toner. was there.

Therefore, methods for suppressing toner blocking have been proposed. For example, Patent Document 1 discloses a toner conveying device that employs a configuration in which a large number of film-like flickers provided in the axial direction are brought into contact with a conveying screw to suppress adhesion of toner to the conveying screw. The flicker is provided to press the conveyance screw toward the inner wall surface of the toner conveyance path. Due to the contact of the flicker, the toner adhering to the conveyance screw is scraped off by the flicker, and toner sticking (blocking) is suppressed.

JP2016-218421A

Incidentally, the conveying screw of the toner conveying device disclosed in Patent Document 1 is formed to be elongated along the rotation axis direction. For this reason, the conveying screw is more likely to deform along the radial direction around the center than around both ends with respect to the rotation axis direction. Then, there is a possibility that the center portion of the conveying screw may be deformed away from the flicker due to the pressing force of the flicker. Therefore, it becomes difficult for the flicker to come into contact with the conveying screw at the deformed location, and there is a possibility that the toner will stay and stick at this location.

SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide a toner conveyance device, a cleaning device equipped with the same, and an image forming apparatus that can maintain toner conveyance performance while effectively suppressing toner sticking.

In order to achieve the above object, a first configuration of the present invention is a toner conveying device including a toner conveying path, a conveying screw, and a scraping member. Toner is transported through the toner transport path. The conveyance screw is provided with a pair of support parts on both sides with the center of the toner conveyance path in between in the axial direction, and has a rotating shaft rotatably supported inside the toner conveyance path by the pair of support parts. , and a spiral blade formed on the outer peripheral surface of the rotating shaft. The scraping member includes a plurality of flickers that abut the outer peripheral surface of the conveying screw and press the conveying screw toward the inner wall surface of the toner conveying path, and are lined up at predetermined intervals along the axial direction. Among the flickers, the flicker closest to the center in the axial direction is defined as the center flicker, and the flicker farthest from the center in the axial direction is defined as the end flicker. Among the flickers, the length of each flicker other than the center flicker is less than or equal to the length of the flicker adjacent to the center side in the axial direction, and the length of the center flicker is longer than the length of the end flicker.

According to the first configuration of the present invention, the length of the center flicker is longer than the end flicker, and the lengths of the other flickers become shorter as they move away from the center in the axial direction. Therefore, even if the center of the conveyance screw is relatively largely deformed in the axial direction so as to move away from the flicker toward the inner wall surface, the contact area between the center flicker and the conveyance screw is difficult to change. Therefore, waste toner around the center of the conveyance screw in the axial direction can be suitably scraped off, and toner sticking within the toner conveyance path can be suppressed.

Therefore, it is possible to provide a toner conveyance device that can maintain toner conveyance performance while effectively suppressing toner sticking.

A cross-sectional view showing a schematic configuration of an image forming apparatus 100 equipped with cleaning devices 7a to 7d including a toner transport device 50 of the present invention. Enlarged view of the vicinity of image forming section Pa in FIG. 1 A side cross-sectional view showing the configuration around the cleaning device 7a including the toner conveying device 50 according to the first embodiment of the present invention in FIG. A partially enlarged view of the conveying screw 29 and scraping member 31 in the cleaning device 7a viewed from the axial direction (perpendicular to the rotating shaft 29a) A plan view of the conveying screw 29 and the scraping member 31 of the toner conveying device 50 of the first embodiment viewed from above in FIG. A plan view of the conveying screw 29 and the scraping member 31 of the toner conveying device 50 of the second embodiment.

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a sectional view showing a schematic configuration of an image forming apparatus 100 equipped with cleaning devices 7a to 7d including a toner conveying device 50 of the present invention. FIG. 2 is an enlarged view of the vicinity of the image forming section Pa in FIG. FIG. 3 is a side cross-sectional view showing the configuration around the cleaning device 7a including the toner conveying device 50 according to the first embodiment of the present invention in FIG. The image forming apparatus 100 according to this embodiment is a 4-tandem color copying machine.

As shown in FIGS. 1 to 3, the image forming apparatus 100 includes image forming sections Pa to Pd, an intermediate transfer unit 12, and cleaning devices 7a to 7d. The image forming sections Pa to Pd are provided in order from one side in the horizontal direction (left side in FIG. 1). The image forming sections Pa to Pd are provided corresponding to images of four different colors (magenta, cyan, yellow, and black), and are formed into magenta, cyan, yellow, and black by each charging, exposure, development, and transfer process. images are formed sequentially.

The image forming sections Pa to Pd include photoreceptor drums 1a to 1d (image carriers), charging devices 2a to 2d, exposure devices 5, and developing devices 3a to 3d. Note that since the image forming sections Pa to Pd basically have the same configuration, only the image forming section Pa will be explained, and the explanation for the image forming sections Pb to Pd will be omitted.

The photosensitive drum 1a is rotatably supported. The photosensitive drum 1a is formed by laminating a photosensitive layer on the outer peripheral surface of an aluminum drum tube. As the photosensitive layer, for example, an organic photosensitive layer (OPC) using an organic photoconductor or an inorganic photosensitive layer such as an amorphous silicon (a-Si) photosensitive layer formed by vapor deposition of silane gas or the like is used.

A charging device 2a, a developing device 3a, and a cleaning device 7a are arranged in this order around the photosensitive drum 1a along the drum rotation direction (clockwise direction in FIG. 2). The charging device 2a includes a charging roller 21 and a brush roller 22. The charging roller 21 contacts the photoreceptor drum 1a and applies a charging bias to the drum surface. The brush roller 22 contacts the charging roller 21 and cleans the charging roller 21.

The exposure device 5 emits a light beam so as to pass between the charging device 2a and the developing device 3a to form an electrostatic latent image on the surface of the photosensitive drum 1a.

The developing device 3 a includes a developing container 20 , an agitation conveyance screw 23 , a supply conveyance screw 24 , and a developing roller 25 . The developer container 20 is filled with a developer containing toner. The stirring conveyance screw 23 and the supply conveyance screw 24 are rotatably supported within the developer container 20. The developing roller 25 is rotatably supported between the supply conveyance screw 24 and the photosensitive drum 1a at positions facing each other.

The toner in the developing container 20 is supplied to the surface of the developing roller 25 while being stirred and conveyed by the stirring conveyance screw 23 and the supply conveyance screw 24 . The toner on the surface of the developing roller 25 is supplied to the surface of the photoreceptor drum 1a and electrostatically adheres thereto. As a result, a toner image (visible image) that is a visible electrostatic latent image is formed on the surface of the photoreceptor drum 1a.

Each of the developing containers 20 of the developing devices 3a to 3d is filled with a predetermined amount of one color of magenta, cyan, yellow, and black toner. Toner containers 4a to 4d corresponding to each color are arranged above the developing devices 3a to 3d. When the ratio of toner in the two-component developer filled in the developing devices 3a to 3d falls below a specified value, toner is replenished from the toner containers 4a to 4d to the developing container 20 of each developing device 3a to 3d. .

Intermediate transfer unit 12 is provided adjacent to image forming sections Pa to Pd. The intermediate transfer unit 12 includes a driven roller 10 , a driving roller 11 , and an intermediate transfer belt 8 . The driven roller 10 and the driving roller 11 are rotatably supported. The driven roller 10 and the driving roller 11 are arranged parallel to the horizontal direction. The drive roller 11 is connected to a drive source (not shown) such as a motor, and is rotated by the driving force of this drive source. The intermediate transfer belt 8 is formed of a sheet made of dielectric resin. The intermediate transfer belt 8 is stretched around a driven roller 10 and a driving roller 11 .

The intermediate transfer belt 8 is in contact with the photosensitive drums 1a to 1d. Primary transfer rollers 6a to 6d are arranged to face the photosensitive drums 1a to 1d, respectively, with the intermediate transfer belt 8 in between. The primary transfer rollers 6a to 6d are driven to rotate at the same linear speed as the photosensitive drums 1a to 1d and the intermediate transfer belt 8 by a primary transfer drive motor (not shown).

A secondary transfer roller 9 is arranged at a position facing the drive roller 11 with the intermediate transfer belt 8 in between. The secondary transfer roller 9 is in pressure contact with the intermediate transfer belt 8 to form a secondary transfer nip portion N. A cleaning blade 19 is arranged downstream of the secondary transfer nip N with respect to the rotation direction of the intermediate transfer belt 8 (counterclockwise as shown in FIG. 1). The cleaning blade 19 is in contact with the outer peripheral surface of the intermediate transfer belt 8 and removes toner and the like remaining on the surface of the intermediate transfer belt 8.

A sheet stacking section 16 that can stack and accommodate sheets S is provided at the bottom of the image forming apparatus 100. A sheet conveying path 14 is connected to the sheet stacking section 16 . The sheet conveyance path 14 extends upward from the sheet stacking section 16 to the discharge roller pair 18 while passing through the secondary transfer nip section N.

A sheet feeding section 61 is provided between the sheet stacking section 16 and the sheet conveying path 14 in the sheet conveying direction. The sheet feeding section 61 feeds the sheets S stacked on the sheet stacking section 16 to the sheet conveyance path 14.

A fixing device 15 is disposed in the sheet conveyance path 14 at a position downstream from the secondary transfer nip portion N with respect to the sheet conveyance direction. A registration roller pair 13 is provided at a position on the upstream side of the secondary transfer nip portion N in the sheet conveyance direction in the sheet conveyance path 14 . A branch portion 17 is provided in the sheet conveyance path 14 at a position downstream from the fixing device 15 in the sheet conveyance direction.

The sheet conveyance path 14 is connected to a reversal conveyance path 60 via a branch portion 17 . The reversing conveyance path 60 extends downward from the branching portion 17 while being curved in a C-shape, and joins the sheet conveyance path 14 at a position upstream of the registration roller pair 13 in the sheet conveyance direction. .

When the drive roller 11 rotates, the intermediate transfer belt 8 rotates while contacting the outer peripheral surfaces of the photoreceptor drums 1a to 1d. At this time, the primary transfer rollers 6a to 6d apply a predetermined transfer voltage between the primary transfer rollers 6a to 6d and the photosensitive drums 1a to 1d. Then, the toner images on the photoreceptor drums 1a to 1d are primarily transferred onto the intermediate transfer belt 8.

Then, the registration roller pair 13 transports the sheet S to the secondary transfer nip portion N at a predetermined timing. As a result, the toner image that has been primarily transferred to the intermediate transfer belt 8 is secondarily transferred to the surface of the sheet S. Thereafter, the toner remaining on the surfaces of the photoreceptor drums 1a to 1d is removed by cleaning devices 7a to 7d, and a new electrostatic latent image is subsequently formed. Details of the cleaning devices 7a to 7d will be described later.

The sheet S onto which the toner image has been transferred is conveyed to a fixing device 15 via a sheet conveyance path 14. The secondarily transferred toner image is fixed onto the sheet S by the fixing device 15. Thereafter, the sheet S is discharged from the image forming apparatus 100. Note that when double-sided printing is performed, the sheet S is distributed to the reversal conveyance path 60 by a branching section 17 provided downstream of the fixing device 15. The reversing conveyance path 60 conveys the sheet S to the secondary transfer nip again while inverting the front and back sides. The toner image is secondarily transferred to the back surface of the re-conveyed sheet S, and the toner image is fixed by the fixing device 15. Then, the sheet S is discharged onto the discharge tray 62 by the discharge roller pair 18.

FIG. 4 is a partially enlarged view of the conveying screw 29 and the scraping member 31 in the cleaning device 7a, viewed from the axial direction (perpendicular to the rotating shaft 29a). FIG. 5 is a plan view of the conveying screw 29 and the scraping member 31 of the toner conveying device 50 of the first embodiment as viewed from above in FIG. 4. As shown in FIG.

As shown in FIGS. 2 to 4, the cleaning device 7a includes a housing 26, a cleaning blade 28 (cleaning member), and a toner conveying device 50. The housing 26 is adjacent to the photosensitive drum 1a in the horizontal direction (radial direction of the photosensitive drum 1a). An opening 30 is formed in the housing 26 at a location adjacent to the photoreceptor drum 1a. The opening 30 is formed to be elongated along the longitudinal direction of the photoreceptor drum 1 .

The cleaning blade 28 is provided at the downstream edge 42 of the opening 30 with respect to the rotational direction of the photosensitive drum 1a (clockwise direction shown in FIG. 4). The cleaning blade 28 protrudes from the housing 26 toward the photoreceptor drum 1a so that its tip extends from the downstream side to the upstream side (in the counter direction) with respect to the rotational direction of the photoreceptor drum 1a. A toner passage opening 43 is formed between the upstream edge 41 of the opening 30 and the tip 28a of the cleaning blade 28 with respect to the rotational direction of the photosensitive drum 1a.

The tip portion 28a is pressed against the outer peripheral surface of the photoreceptor drum 1a. As the photoreceptor drum 1a rotates, toner on the outer peripheral surface of the photoreceptor drum 1a is scraped off by the tip portion 28a. The scraped toner enters the inside of the housing 26 from the toner passage port 43 as waste toner.

As shown in FIGS. 4 and 5, the toner conveyance device 50 includes a toner conveyance path 37, a conveyance screw 29, and a scraping member 31. The toner conveyance path 37 is formed inside the housing 26 . The waste toner that has passed through the toner passage port 43 is stored in the toner conveyance path 37. The toner conveyance path 37 is elongated and parallel to the longitudinal direction of the photoreceptor drum 1a (the longitudinal direction of the cleaning blade 28).

The conveyance screw 29 is housed inside the toner conveyance path 37 . The conveying screw 29 has a rotating shaft 29a and a spiral blade 29b. The rotating shaft 29a is a rod-shaped body arranged parallel to the longitudinal direction of the photoreceptor drum 1a. The rotating shaft 29a has a pair of support parts 44.

The pair of support portions 44 are located on both sides with the center portion C of the toner conveyance path 37 sandwiched therebetween in the axial direction (the longitudinal direction of the rotating shaft 29a). The rotating shaft 29a is rotatably supported in the toner conveyance path 37 by supporting a pair of support parts 44 by a bearing 46 provided on a side wall of the housing 26. The rotating shaft 29a is connected to a drive source (not shown) such as a motor, and is rotated by the rotational driving force of the drive source. The outer peripheral surface of the rotating shaft 29a and the inner wall surface 40 of the toner transport path 37 face each other in the radial direction of the rotating shaft 29a.

The spiral blade 29b is a spiral blade having a constant pitch. The spiral blade 29b is formed integrally with the rotating shaft 29a on the outer peripheral surface of the rotating shaft 29a. When the conveyance screw 29 is not deformed, the distance D between the tip of the spiral blade 29b (the tip of the spiral blade 29b in the radial direction of the rotating shaft 29a) and the inner wall surface 40 is 0.5 mm or more and 1.5 mm or less. It is preferable that

The spiral blade 29b is formed over the entire region of the rotating shaft 29a located within the toner transport path 37 in the axial direction. The area where the spiral blade 29b is formed in the axial direction is defined as a spiral blade forming area A1.

When the rotating shaft 29a rotates, the waste toner stored in the toner conveying path 37 is conveyed along the axial direction by the spiral blade 29b. The waste toner is then discharged to the outside of the cleaning device 7a from a toner discharge port (not shown) formed near the downstream end of the toner conveyance path 27 with respect to the toner conveyance direction.

As shown in FIGS. 4 and 5, the scraping member 31 has a base 32 and a plurality of flickers 33. The base portion 32 is formed to be elongated in the axial direction, parallel to the rotating shaft 29a. The base portion 32 is fixed to a portion of the inner wall surface 40 of the housing 26 located above the rotating shaft 29a with an adhesive or the like.

Here, among the flickers 33, the flicker 33 closest to the center C in the axial direction is defined as the center flicker 33a. Furthermore, the flicker 33 furthest from the center C in the axial direction is defined as an end flicker 33b. The flickers 33 other than the center flicker 33a and the end flicker 33b are referred to as third flickers 33c. If these are not particularly distinguished, they are simply referred to as flicker 33.

Each flicker 33 is arranged at equal intervals throughout the spiral blade forming region A1 in the axial direction. The interval between the flickers 33 in the axial direction is equal to or less than 1/2 of the pitch in the axial direction of the spiral blades 29b.

The flicker 33 is a film-like rectangular plate. The width of the flicker 33 in the axial direction is preferably 1 mm or more and 2 mm or less. The material of the flicker 33 is not particularly limited as long as it is an elastic material that swings in contact with the spiral blade 29b of the conveying screw 29. For example, a sheet made of polyethylene terephthalate (PET), a sheet made of fluororesin, a sheet made of polyimide, etc. Although various synthetic resin sheets with low frictional resistance such as sheets can be used, polyethylene terephthalate sheets are preferred from the viewpoint of cost and durability.

The flicker 33 is connected to an edge 45 of the base 32 on the side far from the cleaning blade 28 in the width direction of the base 32 that is perpendicular to the axial direction. The flicker 33 extends from the base 32 toward the cleaning blade 28 while passing above the rotating shaft 29a. The flicker 33 and the conveyance screw 29 are opposed to each other in the radial direction of the rotating shaft 29a.

The tip of the flicker 33 is located closer to the opening 30 than the rotating shaft 29a in the horizontal direction. The surface of the flicker 33 on the rotating shaft 29a side is in contact with the outer circumferential surface of the conveying screw 29 from above (see FIGS. 3 and 4). The flicker 33 presses the conveyance screw 29 toward the inner wall surface 40 of the toner conveyance path 37 from the contact position with the conveyance screw 29 .

As the conveyance screw 29 rotates, the flicker 33 alternately contacts the rotating shaft 29a and the spiral blade 29b. At this time, the flicker 33 is lifted by using the connecting portion with the base 32 (edge 45 of the base 32) as a fulcrum, and the position where it contacts the rotating shaft 29a (dotted chain line in FIG. 4) and the position where it contacts the spiral blade 29b. (solid line in Figure 4). While in contact with the spiral blade 29b, the flicker 33 is lifted by the spiral blade 29b and elastically deforms so as to separate from the rotating shaft 29a. Furthermore, the flicker 33 moves closer to the rotating shaft 29a due to the restoring force.

The center flicker 33a is located at a position overlapping the center portion C in the axial direction. The length L1 (dimension from the edge 45 to the tip in the longitudinal direction) of the central flicker 33a is longer than the length L2 of the end flicker 33b and the length of the third flicker 33c. Further, the length L1 of the center flicker 33a is greater than or equal to the sum of the length L2 of the end flicker 33b and the above-mentioned interval D.

The lengths of the end flicker 33b and the third flicker 33c are shorter than the length of the flicker 33 adjacent to the center C side in the axial direction. The length of the third flicker 33c becomes uniformly short as it moves away from the central flicker 33a in the axial direction. The length of the end flicker 33b is the shortest among the flickers 33.

As described above, the flicker 33 contacts the outer circumferential surface of the conveyance screw 29, and as the conveyance screw 29 rotates, the flicker 33 swings so as to alternate between a state in which it contacts the spiral blade 29b and a state in which it contacts the rotating shaft 29a. do. This contact of the flicker 33 makes it possible to scrape off residual toner on the outer peripheral surface of the conveying screw 29.

Further, as described above, the length of the center flicker 33a is longer than the end flicker 33b, and the length of the third flicker 33c becomes shorter as the distance from the center portion C increases in the axial direction. Therefore, even if the center of the conveyance screw 29 (around the center of the rotating shaft 29a in the axial direction) is relatively largely deformed toward the inner wall surface 40 and away from the flicker 33, the central flicker 33a Continue to touch 29b. This makes it difficult for the contact area between the central flicker 33a and the conveying screw 29 to change. Therefore, waste toner around the center of the conveyance screw 29 in the axial direction can be suitably scraped off, and toner sticking within the toner conveyance path 37 can be suppressed.

Further, as described above, the length L1 of the center flicker 33a is greater than or equal to the sum of the length L2 of the end flicker 33b and the above-mentioned interval D. Here, when the periphery of the center of the conveyance screw 29 in the axial direction is deformed toward the inner wall surface 40, the amount of deformation is at most the distance D. Therefore, even if the conveyance screw 29 deforms to the point where it comes into contact with the inner wall surface 40, the central flicker 33a will come into contact with the conveyance screw 29, and the waste toner can be suitably scraped off from the outer peripheral surface of the conveyance screw 29.

Further, as described above, the flickers 33 are arranged in the axial direction at an interval of 1/2 or less of the axial pitch of the spiral blades 29b. Therefore, the flicker 33 contacts the entire area of the spiral blade 29b and the rotating shaft 29a evenly. Thereby, waste toner can be suitably scraped off from the outer circumferential surface of the conveying screw 29.

Next, a second embodiment of the present invention will be described. FIG. 6 is a plan view of the conveying screw 29 and the scraping member 31 of the toner conveying device 50 of the second embodiment.

As shown in FIG. 6, the area where the flickers 33 are lined up is divided into a central area A2 and an outer area A3. The central region A2 is located at the center of the toner transport path 37 in the axial direction. The central region A2 is located at a position overlapping the central portion C in the axial direction. The outer region A3 is a region located on both outer sides of the central region A2 in the axial direction. The length of the central region A2 in the axial direction is 1/4 or more and 3/4 or less of the sum of the lengths of the outer regions A3.

The lengths of the flickers 33 arranged in the central area A2 are all equal to the length L1 of the central flicker 33a. The length of the flicker 33 placed in the central area A2 is longer than the length of the flicker 33 placed in the outer area A3.

The flicker 33 disposed in the outer region A3 becomes uniformly short in length as it moves away from the central portion C in the axial direction.

By doing so, even if the center of the conveying screw 29 (around the center of the rotating shaft 29a in the axial direction) is relatively largely deformed toward the inner wall surface 40 and away from the flicker 33, it will not be disposed in the central region A2. The plurality of flickers 33 continue to contact the rotating shaft 29a and the spiral blade 29b. The contact area between the conveyor screw 29 and the transport screw 29 is difficult to change. This makes it difficult for the contact area between the plurality of flickers 33 arranged in the central area A2 and the conveying screw 29 to change. Therefore, waste toner around the center of the conveyance screw 29 in the axial direction can be suitably scraped off, and toner sticking within the toner conveyance path 37 can be suppressed.

In addition, the present invention is not limited to the above embodiments, and various changes can be made without departing from the spirit of the present invention. For example, in each of the above embodiments, only a configuration in which only the cleaning blade 28 is provided as the cleaning devices 7a to 7d is described, but the present invention is not limited to this. For example, the cleaning devices 7a to 7d may have a configuration including a rubbing roller that removes toner on the surface of the drum while rubbing against the photoreceptor drums 1a to 1d, or a configuration including a fur brush instead of the cleaning blade 28, etc. The present invention can be applied to cleaning devices having various configurations having the screw 29.

Further, in each of the above embodiments, the center flicker 33a is located at a position overlapping the center portion C in the axial direction, but may be located at a position shifted from the center portion C. In this case, the flicker 33 closest to the center portion C in the axial direction is defined as the center flicker 33a. Further, in each of the above embodiments, the pair of flickers 33 located at both ends in the axial direction are referred to as the end flickers 33b, but this is because the distances between the flickers 33 at both ends and the center portion C in the axial direction are This is because they have the same configuration. When the distances between the flickers 33 at both ends and the center portion C in the axial direction are different, the one with the larger distance is defined as the end flicker 33b.

Furthermore, the present invention is applicable not only to the transport of waste toner within the cleaning devices 7a to 7d, but also to the waste toner transport path from the cleaning devices 7a to 7d to a waste toner collection container (not shown). Alternatively, it is also applicable to the toner supply path from the toner containers 4a to 4d to the developing devices 3a to 3d.

INDUSTRIAL APPLICATION This invention can be utilized for the toner conveyance apparatus which conveys the waste toner removed from the surface of an image carrier, and the toner replenished to a developing device. By utilizing the present invention, it is possible to provide a toner conveyance device that can effectively prevent solidification of toner and maintain stable toner conveyance performance, and a cleaning device and an image forming apparatus equipped with the same.

1a to 1d Photosensitive drum (image carrier)
7a to 7d Cleaning device 26 Housing 27 Toner transport path 28 Cleaning blade (cleaning member)
29 Conveyance screw 29a Rotating shaft 29b Spiral blade 30 Opening 31 Scraping member 33 Flicker 33a Center flicker 33b End flicker 37 Toner conveyance path 40 Inner wall surface 44 Support portion 50 Toner conveyance device 100 Image forming device A2 Central area A3 Outer area C Center part D Spacing L1 Length of center flicker L2 Length of edge flicker Pa to Pd Image forming section

Claims (9)

a toner conveyance path through which toner is conveyed;
a rotating shaft that is provided with a pair of support parts on both sides of the toner transport path with the center thereof interposed therebetween in the axial direction, and is rotatably supported within the toner transport path by the pair of support parts; a conveyance screw having a spiral blade formed on the outer peripheral surface of the rotating shaft;
a scraping member configured such that a plurality of flickers are lined up at predetermined intervals along the axial direction and abut against an outer circumferential surface of the conveying screw and press the conveying screw toward an inner wall surface of the toner conveying path; ,
In a toner transport device equipped with
Among the flickers, the flicker closest to the center in the axial direction is defined as a center flicker, and the flicker farthest from the center in the axial direction is defined as an end flicker,
Among the flickers, the length of the flicker other than the center flicker is less than or equal to the length of the flicker adjacent to the center side in the axial direction, and the length of the center flicker is equal to A toner conveying device characterized by being longer than a flicker. The length of the center flicker is determined by the length of the end flicker, the spiral blade in the radial direction of the rotating shaft, and the inner wall surface of the toner conveyance path facing the conveyance screw in the pressing direction of the flicker. 2. The toner conveying device according to claim 1, wherein the length is longer than the sum of the intervals. The toner conveying device according to claim 2, wherein the interval is 0.5 mm or more and 1.5 mm or less. The central flicker overlaps the central portion in the axial direction,
The toner conveying device according to any one of claims 1 to 3, wherein the length of the flicker is the longest at the center flicker, and becomes uniformly shorter as the distance from the center flicker increases in the axial direction. . The area where the flickers are lined up in the axial direction is divided into a central area including the central part and outer areas located on both sides of the central area,
The length of the central region in the axial direction is 1/4 or more and 3/4 or less of the sum of the lengths of each of the outer regions,
The length of the flicker located in the central region is equal to the length of the central flicker and longer than the length of the flicker located in the outer region, according to any one of claims 1 to 3. toner transport device. 6. The toner conveying device according to claim 1, wherein an interval between adjacent flickers is 1/2 or less of a pitch of the spiral blades of the conveying screw. An image forming apparatus comprising the toner conveying device according to claim 1. a housing having an opening formed to face the outer peripheral surface of the image carrier, into which waste toner removed from the outer peripheral surface of the image carrier is introduced through the opening;
a cleaning member that comes into contact with the outer peripheral surface of the image carrier through the opening;
The toner conveying device according to any one of claims 1 to 6,
Equipped with
In the cleaning device, the toner transport path is formed at the bottom of the housing. an image forming unit that transfers the toner on the image carrier onto a recording medium to form an image;
A cleaning device according to claim 8;
An image forming apparatus comprising:

Images