Toner recovery device and image forming apparatus equipped with toner recovery device

Abstract

To provide a toner recovery device that can prevent false detection of a detection sensor and appropriately replace a toner recovery container.SOLUTION: A toner recovery device comprises a toner recovery container, a toner conveyance path, a side wall part, a detection recess, and a detection sensor. The toner conveyance path is configured by including a downgrade first inclined part that is provided immediately below a toner recovery port and extends to the left in a lateral direction orthogonal to a vertical direction, and a downgrade second inclined part that is connected with a lower end of the first inclined part, extends to the front in the fore-and-aft direction orthogonal to the vertical direction and the lateral direction, and is in contact, at its left side end part, with a left side inner wall surface of the toner recovery container. The side wall part is erected from a right side end part of the second inclined part. The detection recess has an opening between an upper end of the side wall part and the inner wall surface of the toner recovery container and is communicated to the rear side of the second inclined part. The detection sensor detects whether waste toner is present at a predetermined position in the vertical direction inside the detection recess.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a toner recovery device and an image forming apparatus equipped with the toner recovery device. [Background technology]

[0002] In image forming apparatuses (such as copy machines, printers, and fax machines) using electrophotography, an electrostatic latent image formed on an image carrier such as a photosensitive drum is visualized by toner (powdered developer) in a developing device, and the toner image is transferred directly or via an intermediate transfer body onto a recording medium, followed by a fixing process. Such image forming apparatuses are equipped with a cleaning device for removing residual toner from the surface of the image carrier or intermediate transfer body. The residual toner removed by the cleaning device is transported to a toner recovery container as waste toner and stored there. The toner recovery container is replaceable, and is replaced by an operator (such as a user or a maintenance worker) as appropriate.

[0003] The cleaning device is provided with a waste toner transport unit that transports waste toner. The waste toner transport unit is provided with a toner transport path and a transport screw for transporting toner. An opening is formed at the downstream end of the toner transport path. The opening is aligned vertically with a toner recovery port formed at the top of the toner recovery container. The waste toner in the toner transport path is transported to the opening by the transport screw, and is fed from the opening through the toner recovery port into the toner recovery container. This process of removing the residual toner on the image carrier is continuously performed while the image forming apparatus is forming an image. During the process of removing the residual toner, the waste toner is sequentially fed into the toner recovery container.

[0004] Here, the waste toner put into the toner recovery container gradually accumulates from the bottom of the toner recovery container. When the accumulated waste toner reaches the toner recovery port, the toner recovery port is blocked, and the toner recovery container becomes full, making it impossible to put the waste toner into the toner recovery container. If the residual toner removal process continues while the toner recovery container is full, the waste toner may flow back to the image carrier or the intermediate transfer body. For this reason, in such an image forming apparatus, it is necessary to replace the toner recovery container at an appropriate time before the toner recovery container becomes full. Therefore, Patent Document 1 discloses a toner recovery device equipped with a detection sensor capable of detecting the amount of waste toner in the toner recovery container so that an operator can replace the toner recovery container at an appropriate time before the toner recovery container becomes full.

[0005] The detection sensor of Patent Document 1 is disposed around the toner recovery port in order to detect whether the waste toner is sufficiently stored in the toner recovery container (see FIG. 2 of Patent Document 1). The detection sensor is an optical sensor such as a photointerrupter that includes a light-emitting unit that emits light and a light-receiving unit that receives the light emitted from the light-emitting unit. The light-emitting unit and the light-receiving unit are disposed at a predetermined position in the vertical direction of the toner recovery container so as to sandwich the toner recovery container from both sides in its width direction (direction perpendicular to the vertical direction). The detection sensor is connected to a control unit provided at an arbitrary position of the image forming device, and detects the presence or absence of waste toner between the light-emitting unit and the light-receiving unit (the above-mentioned predetermined position) depending on the light receiving state of the light-receiving unit, and transmits the detection result to the control unit.

[0006] When the waste toner gradually accumulates in the toner recovery container and reaches the predetermined position, the light emitted by the light-emitting unit is blocked by the waste toner, and the light-receiving state of the light-receiving unit changes. When this detection result is sent to the control unit, the control unit displays on the operation screen of the image forming device, etc., the time to replace the toner recovery container. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] JP 2015-94890 A Summary of the Invention [Problem to be solved by the invention]

[0008] Incidentally, waste toner inserted from the toner recovery port may adhere to the inner wall surface of the toner recovery container and remain there instead of falling. In particular, waste toner is likely to scatter around the toner recovery port due to impact when the toner is inserted, and a large amount of waste toner adheres thereto. Since the above detection sensor is disposed around the toner recovery port as described above, if waste toner adheres to the detection point of the detection sensor (a point located between the light receiving unit and the light emitting unit on the inner wall surface of the toner recovery container), the light receiving state of the light receiving unit changes. Then, even if there is not enough waste toner accumulated in the toner recovery container, the detection sensor may erroneously detect that the toner recovery container is full.

[0009] In addition, since the waste toner falls from the toner recovery port and is thrown into the toner recovery container, it accumulates intensively around the area immediately below the toner recovery port. Therefore, the waste toner is likely to accumulate in the toner recovery container in a mountain shape with the area immediately below the toner recovery port as its peak. Here, as described above, the detection sensor is provided around the toner recovery port. Therefore, the waste toner may not be sufficiently stored at a position away from the toner recovery port inside the toner recovery container, and the waste toner may accumulate around the detection point. Then, the detection sensor erroneously detects that the toner recovery container is full, while a lot of storage space for the waste toner remains in the toner recovery container. In this way, the toner recovery device of Patent Document 1 makes it difficult to properly replace the toner recovery container.

[0010] SUMMARY OF THE PRESENT DISCLOSURE In view of the above, an object of the present invention is to provide a toner recovery device that can suppress erroneous detection by a detection sensor and can properly replace a toner recovery container. [Means for solving the problem]

[0011] In order to achieve the above object, the present invention provides a toner recovery device including a toner recovery container, a toner transport path, a side wall, a detection recess, and a detection sensor. The toner recovery container is formed with a toner recovery port into which waste toner on a toner carrier is poured, and is capable of storing waste toner poured from the toner recovery port inside. The toner transport path is provided directly below the toner recovery port, and includes a first inclined portion with a downward slope extending leftward in a left-right direction perpendicular to the up-down direction, and a second inclined portion with a downward slope connected to the lower end of the first inclined portion, extending forward in a front-rear direction perpendicular to the up-down direction and the left-right direction, and a side end portion on the left side abutting against an inner wall surface on the left side of the toner recovery container, and transports waste toner poured from the toner recovery port along the first inclined portion and the second inclined portion toward the bottom of the toner recovery container. The side wall portion rises from a side end portion on the right side of the second inclined portion. The detection recess has an opening between an upper end of the side wall portion and an inner wall surface of the toner recovery container, and communicates with the rear side of the second inclined portion. The detection sensor detects the presence or absence of waste toner at a predetermined vertical position inside the detection recess. Effect of the Invention

[0012] According to the configuration of the present invention, the first inclined portion is disposed directly below the toner recovery port, and the second inclined portion is connected to the lower end of the first inclined portion, so that the waste toner put in from the toner recovery port is transported to the bottom of the toner recovery container so as to slide down the first inclined portion and the second inclined portion. This makes it possible to prevent the waste toner from being concentrated and accumulated directly below the toner recovery port, and to efficiently store the waste toner in the storage space in the toner recovery container.

[0013] In addition, a side wall is provided on the right side end of the second inclined portion, and an opening of the detection recess is formed between the upper end of the side wall and the inner wall surface of the toner recovery container. Therefore, the side wall prevents waste toner fed from the toner recovery port from entering the detection recess. This makes it difficult for waste toner to adhere to the inner wall surface around the detection sensor in the detection recess, thereby reducing false detections by the detection sensor.

[0014] According to the configuration of the present invention, when a predetermined amount or more of waste toner is stored in the toner recovery container and the waste toner is piled up to the lower end of the second inclined portion, newly added waste toner is piled up on the second inclined portion. The waste toner piled up on the second inclined portion reaches the upper end of the side wall portion and passes through the opening by climbing over the upper end of the side wall portion, so that the waste toner enters the detection recess. Therefore, until a predetermined amount or more of waste toner (the amount at which the waste toner on the second inclined portion reaches the upper end of the side wall portion) is stored in the toner recovery container, the waste toner is less likely to enter the detection recess. In other words, it is possible to prevent the detection sensor from erroneously detecting that the toner recovery container is full while leaving a large amount of waste toner storage space in the toner recovery container.

[0015] Therefore, the present invention can provide a toner recovery device that can suppress erroneous detection by the detection sensor and properly replace the toner recovery container. [Brief description of the drawings]

[0016] [Figure 1] FIG. 1 is a schematic cross-sectional view of an image forming apparatus 100 equipped with a toner recovery device 21 according to the present invention. [Diagram 2] FIG. 2 is a perspective view showing the toner recovery device 21 and the waste toner transport unit 25 of the present invention. [Diagram 3] FIG. 2 is a front cross-sectional view showing the internal structure of the toner recovery device 21 of the present invention (cross-sectional view taken along the line A-A' in FIG. 1). [Figure 4] FIG. 4 is a cross-sectional view of the toner recovery device 21 of the present invention taken along the line BB′ shown in FIG. [Diagram 5] FIG. 4 is a cross-sectional view of the toner recovery device 21 of the present invention taken along the line CC′ in FIG. [Figure 6] 6 is a cross-sectional view of the toner recovery container 23 taken along the line DD′ shown in FIG. [Figure 7] FIG. 3 is a cross-sectional view showing the toner collection container 23 in a state where waste toner is stored. [Figure 8] 8 is a cross-sectional view of the toner recovery container 23 shown in FIG. 7 taken along the line EE′. [Figure 9]FIG. 11 is a cross-sectional view showing a state in which waste toner is stored in the detection recess 29. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0017] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. Fig. 1 is a schematic cross-sectional view of an image forming apparatus 100 equipped with a toner recovery device 21 of the present invention. Four image forming sections Pa, Pb, Pc, and Pd are arranged in the main body of the image forming apparatus 100 (here, a color printer) in order from the upstream side in the transport direction (the right side in Fig. 1). These image forming sections Pa to Pd are provided corresponding to images of four different colors (magenta, cyan, yellow, and black), and sequentially form images of magenta, cyan, yellow, and black through the respective processes of charging, exposure, development, and transfer.

[0018] The image forming units Pa to Pd are provided with photoconductor drums (toner image carriers) 1a, 1b, 1c, and 1d that carry visible images (toner images) of each color, and the toner images formed on the photoconductor drums 1a to 1d are sequentially transferred (primary transfer) onto an intermediate transfer belt 8 that moves adjacent to each image forming unit while rotating clockwise in Fig. 1 by a driving device (not shown), and then transferred (secondary transfer) all at once onto paper S (recording medium) by a secondary transfer roller 9, and further fixed on the paper S by a fixing unit 7, and then discharged from the device main body. An image forming process is performed on each of the photoconductor drums 1a to 1d while the photoconductor drums 1a to 1d are rotated counterclockwise as shown in Fig. 1.

[0019] The paper S onto which the toner image is transferred is stored in a paper cassette 16 at the bottom of the device, and is transported to the secondary transfer roller 9 via a paper feed roller 12a and a pair of registration rollers 12b. A sheet made of dielectric resin is used for the intermediate transfer belt 8, and a belt having an endless shape with both ends overlapped and joined together, or a seamless belt is used. In addition, a blade-shaped belt cleaner 19 is disposed downstream of the secondary transfer roller 9 to remove toner remaining on the surface of the intermediate transfer belt 8.

[0020] Next, the image forming units Pa to Pd will be described. Around and below the rotatably arranged photoconductor drums 1a to 1d, there are provided chargers 2a, 2b, 2c, and 2d that charge the photoconductor drums 1a to 1d, an exposure unit 4 that exposes image information onto each of the photoconductor drums 1a to 1d, developing units 3a, 3b, 3c, and 3d that form toner images on the photoconductor drums 1a to 1d, and cleaning units 5a, 5b, 5c, and 5d that remove developer (toner) remaining on the photoconductor drums 1a to 1d.

[0021] When a user inputs a command to start image formation, first, the surfaces of the photosensitive drums 1a-1d are uniformly charged by the chargers 2a-2d, and then the exposure unit 4 irradiates light to form electrostatic latent images on the photosensitive drums 1a-1d according to the image signal. The development units 3a-3d include development rollers (developer carriers) arranged opposite the photosensitive drums 1a-1d, and are filled with a predetermined amount of toner of each color, magenta, cyan, yellow, and black, by toner cartridges (not shown). The toner is supplied onto the photosensitive drums 1a-1d by the development rollers of the development units 3a-3d, and electrostatically adheres to the photosensitive drums 1a-1d, forming a toner image according to the electrostatic latent image formed by exposure from the exposure unit 4.

[0022] Then, after an electric field is applied to the intermediate transfer belt 8 with a predetermined transfer voltage, the magenta, cyan, yellow, and black toner images on the photoconductor drums 1a to 1d are primarily transferred onto the intermediate transfer belt 8 by the primary transfer rollers 6a to 6d. These four color images are formed with a predetermined positional relationship for forming a predetermined full-color image. Thereafter, in preparation for the subsequent formation of a new electrostatic latent image, the toner remaining on the surfaces of the photoconductor drums 1a to 1d is removed by the cleaning units 5a to 5d.

[0023] The intermediate transfer belt 8 is stretched around a driven roller 10, a driving roller 11, and a tension roller 20. When the intermediate transfer belt 8 starts to rotate clockwise with the rotation of the driving roller 11 by a driving motor (not shown), the paper S is transported from the registration roller 12b to a secondary transfer roller 9 provided adjacent to the intermediate transfer belt 8 at a predetermined timing, and a full-color image is secondarily transferred onto the paper S at a nip portion (secondary transfer nip portion) with the intermediate transfer belt 8. The paper S with the transferred toner image is transported to the fixing unit 7.

[0024] The paper S conveyed to the fixing section 7 is heated and pressurized as it passes through the nip section (fixing nip section) of the pair of fixing rollers 13, so that the toner image is fixed onto the surface of the paper S and a predetermined full-color image is formed. The paper S on which the full-color image has been formed is then redirected in a conveying direction by a branching section 14 which branches into multiple directions. When an image is formed on only one side of the paper S, the paper S is directly discharged onto a discharge tray 17 by discharge rollers 15.

[0025] On the other hand, when images are formed on both sides of the paper S, a part of the paper S that has passed through the fixing unit 7 is once protruded from the discharge roller 15 to the outside of the device. In this state, by rotating the discharge roller 15 in the reverse direction, the paper S is diverted to the paper transport path 18 at the branching unit 14 with the image side (the side on which the image is formed) inverted, and is transported again to the secondary transfer roller 9. Then, the next image formed on the intermediate transfer belt 8 is transferred by the secondary transfer roller 9 to the side of the paper S on which no image is formed, and the paper is transported to the fixing unit 7 where the toner image is fixed, and then discharged to the discharge tray 17.

[0026] A toner recovery device 21 that recovers and stores waste toner scraped off by the cleaning units 5a to 5d and belt cleaner 19 is disposed at the bottom of the device, and is connected to the cleaning units 5a to 5d and belt cleaner 19 via a waste toner transport unit 25 (waste toner transport unit). The waste toner transport unit 25 includes a transport screw 24 that transports waste toner therein (see FIG. 2), and transports waste toner generated by the cleaning units 5a to 5d and belt cleaner 19 to the toner recovery device 21. The waste toner transport unit 25 has a discharge port 32 formed at the downstream end in the waste toner transport direction (see FIG. 2), and discharges waste toner through the discharge port 32.

[0027] Fig. 2 is a perspective view showing the toner recovery device 21 of the present invention and the waste toner transport unit 25. Fig. 3 is a front cross-sectional view (cross-sectional view taken along the A-A' cross-sectional line in Fig. 1) showing the internal structure of the toner recovery device 21 of the present invention. Fig. 4 is a cross-sectional view taken along the BB' cross-sectional line of the toner recovery device 21 of the present invention shown in Fig. 3. Fig. 5 is a cross-sectional view taken along the CC' cross-sectional line of the toner recovery device 21 of the present invention shown in Fig. 3.

[0028] In the following, among the directions perpendicular to the up-down direction (the direction of the arrow ZZ' shown in Figs. 1, 2, 3, and 5), the direction along the width direction of the image forming apparatus 100 is referred to as the left-right direction (the direction of the arrow X-X' shown in Figs. 1, 2, 4, and 5). Furthermore, the direction perpendicular to the up-down direction and the left-right direction is referred to as the front-rear direction (the direction of the arrow YY' shown in Figs. 2, 3, and 4). Furthermore, one of the front-rear directions (the direction of the arrow Y shown in each figure) is referred to as the "front", and the other (the direction of the arrow Y' shown in each figure) is referred to as the "rear". Furthermore, one of the left-right directions (the direction of the arrow X shown in each figure) is referred to as the "left", and the other (the direction of the arrow X' shown in each figure) is referred to as the "right".

[0029] As shown in FIGS. 1, 2, and 3, the toner recovery device 21 includes a toner recovery container 23, a toner transport path 27, a side wall portion 28, a detection recess 29, and a detection sensor 30. The toner recovery container 23 is a bottomed container capable of accommodating waste toner transported by the waste toner transport unit 25. A toner recovery port 31 is formed on the top surface of the toner recovery container 23. The toner recovery port 31 is a through hole that penetrates the top surface portion of the toner recovery container 23 in the vertical direction. The toner recovery port 31 is disposed below the discharge port 32 of the waste toner transport unit 25. The toner recovery port 31 receives the waste toner discharged from the discharge port 32 and inputs it into the toner recovery container 23.

[0030] The toner transport path 27 is disposed below the toner recovery port 31, and transports the waste toner input from the toner recovery port 31 into the toner recovery container 23. The toner transport path 27 includes a first inclined portion 33 provided directly below the toner recovery port 31, and a second inclined portion 34 connected to the first inclined portion 33.

[0031] 4 and 5, the first inclined portion 33 is a plate-like body that slopes downward toward the left in the left-right direction (the direction of the arrow X in FIGS. 4 and 5). Waste toner fed from the toner recovery port 31 falls onto the first inclined portion 33 and slides down to the lower end of the first inclined portion 33. The inclination angle of the first inclined portion 33 (the inclination of the first inclined portion 33 with respect to the horizontal plane) is larger than the angle of repose of the waste toner.

[0032] As shown in Figs. 3 and 4, the second inclined portion 34 is a plate-like body that slopes downward toward the front in the front-rear direction (the direction of the arrow Y in Figs. 3 and 4). The upper end of the second inclined portion 34 is connected to the inner wall surface on the rear side of the toner recovery container 23, and extends forward from the upper end to the lower end. The inclination angle of the second inclined portion 34 (the inclination of the second inclined portion 34 with respect to the horizontal plane) is larger than the angle of repose of the waste toner. The upper end of the second inclined portion 34 is connected to the lower end of the first inclined portion 33. The waste toner that slides down the first inclined portion 33 to the left slides down the second inclined portion 34 toward the front and falls from the lower end of the second inclined portion 34 toward the bottom 35 of the toner recovery container 23.

[0033] Fig. 6 is a cross-sectional view of the toner recovery container 23 taken along the line DD' shown in Fig. 5. As shown in Figs. 5 and 6, the side wall portion 28 is formed so as to rise from the side end portion on the right side of the second inclined portion 34. The side wall portion 28 extends from the upper end portion to the lower end portion of the second inclined portion 34 along the waste toner transport direction (see Fig. 5).

[0034] The side wall portion 28 has a third inclined portion 36 that is connected to the right side end portion of the second inclined portion 34. The third inclined portion 36 slopes downward from the upper end (the apex of the side wall portion 28) to the left.

[0035] The waste toner sliding down the second inclined portion 34 passes through a waste toner transport section 37 surrounded by the second inclined portion 34, the inner wall surface on the left side of the toner recovery container 23, and the third inclined portion 36. The cross-sectional area of ​​the region surrounded by the side wall portion 28, the second inclined portion 34, and the toner recovery container 23 is approximately equal to the area of ​​the toner transport space in a cross section perpendicular to the axis of the transport screw 24 (the space partitioned by the spiral blade and the rotation shaft of the transport screw 24, and through which the waste toner is transported by the rotation of the spiral blade).

[0036] 6, the detection recess 29 has an opening 38 between the apex of the side wall 28 and the inner wall surface on the right side (arrow X' direction) of the toner recovery container 23, and is a recess that is recessed rearward (arrow Y' direction) from the opening 38. The detection recess 29 communicates with the internal space of the toner recovery container 23 through the opening 38. Waste toner inside the toner recovery container 23 enters the detection recess 29 from the opening 38 and accumulates therein.

[0037] 6, the detection sensor 30 is an optical sensor such as a photointerrupter that includes a light-emitting unit 39 that emits light and a light-receiving unit 40 that receives the light emitted from the light-emitting unit 39. The detection sensor 30 is disposed outside the toner recovery container 23 so as to overlap with the detection recess 29 in the front-rear direction. The light-emitting unit 39 and the light-receiving unit 40 are disposed so as to sandwich the detection recess 29 between them in the left-right direction. The detection sensor 30 is connected to a control unit (not shown) provided at a predetermined location in the image forming apparatus 100. The detection result of the detection sensor 30 is transmitted to the control unit.

[0038] The detection sensor 30 detects whether or not there is waste toner between the light-emitting unit 39 and the light-receiving unit 40 based on the light-receiving state of the light-receiving unit 40. Specifically, the light-receiving state of the light-receiving unit 40 when there is no waste toner between the light-emitting unit 39 and the light-receiving unit 40 (the state shown in FIG. 6) is set as a reference state. When waste toner accumulates between the light-emitting unit 39 and the light-receiving unit 40 (see FIG. 9), the light emitted from the light-emitting unit 39 is blocked by the waste toner, and the light-receiving state changes from the above-mentioned reference state. This detection result is sent to the control unit, and the control unit displays on the operation screen or the like of the image forming apparatus 100 that a predetermined amount of waste toner is stored in the toner recovery container 23.

[0039] As described above, the waste toner input from the toner recovery port 31 is transported to the bottom 35 of the toner recovery container 23 by the toner transport path 27 so as to slide down the first inclined portion 33 and the second inclined portion 34. Here, the side wall portion 28 is provided at the right side end portion of the second inclined portion 34. Therefore, the waste toner input from the toner recovery port 31 is prevented from entering the detection recessed portion 29 by the side wall portion 28, and is transported to the bottom 35 of the toner recovery container 23 through the second inclined portion 34.

[0040] Fig. 7 is a cross-sectional view showing the toner recovery container 23 in a state where waste toner is stored. Fig. 8 is a cross-sectional view of the toner recovery container 23 shown in Fig. 7 taken along the line EE'. Fig. 9 is a cross-sectional view showing a state where waste toner is stored in the detection recess 29.

[0041] As shown in Fig. 7, when the amount of waste toner stored in toner recovery container 23 increases and the waste toner accumulates above the lower end of second inclined portion 34, the waste toner accumulates in toner transport path 27. As described above, the side wall portion 28 prevents the waste toner in toner transport path 27 from entering detection recess 29. However, as shown in Fig. 9, when the amount of waste toner stored in toner recovery container 23 exceeds a predetermined amount and the amount of waste toner in toner transport path 27 exceeds a certain amount, the waste toner climbs over side wall portion 28, enters detection recess 29 from opening 38, and is stored in detection recess 29.

[0042] The accumulation of waste toner in the detection recess 29 progresses gradually from the bottom as the amount of waste toner accumulated in the toner recovery container 23 increases. When the waste toner accumulates up to a predetermined position in the detection recess 29 in the vertical direction, the light emitted from the light-emitting unit 39 is blocked, and the light-receiving state of the light-receiving unit 40 changes. As a result, the control unit displays on the operation screen of the image forming device, etc., that a predetermined amount of waste toner is accumulated in the toner recovery container 23.

[0043] As described above, the waste toner input from the toner recovery opening 31 is prevented from entering the detection recess 29 by the side wall 28 and gradually accumulates in the toner recovery container 23. This prevents the waste toner from adhering to the periphery of the detection sensor 30 in the detection recess 29, which may result in the detection sensor 30 making an erroneous detection. In addition, the waste toner is prevented from entering the opening 38 by the side wall 28 until the amount of waste toner stored in the toner recovery container 23 reaches a predetermined amount or more (at least the amount of waste toner that reaches the lower end of the second inclined portion 34), which prevents the detection sensor 30 from detecting the waste toner when the waste toner is not sufficiently stored in the toner recovery container 23. This allows the toner recovery container 23 to be replaced efficiently.

[0044] As described above, the side wall 28 is formed with the third inclined portion 36. Therefore, even if the waste toner that has entered the second inclined portion 34 from the first inclined portion 33 collides with the side wall 28, the waste toner is likely to fall along the third inclined portion 36 to the second inclined portion 34, and the waste toner can be prevented from adhering to the side wall 28. Furthermore, the waste toner in the toner conveying path 27 is likely to concentrate on the second inclined portion 34 as the waste toner slides down from the third inclined portion 36. Then, when a predetermined amount of waste toner is stored in the toner collecting container 23, the waste toner gradually accumulates from the second inclined portion 34 located at the bottom of the toner conveying path 27. Therefore, the so-called dead space where the waste toner is not accumulated is reduced, and the waste toner can be efficiently stored in the toner collecting container 23.

[0045] As described above, the inclination angles of the first inclined portion 33 and the second inclined portion 34 are set to be larger than the angle of repose of the waste toner. Therefore, the waste toner that falls onto the first inclined portion 33 or the second inclined portion 34 does not remain at the point where it falls, but is transported downstream of the toner transport path 27. This makes it possible to prevent the waste toner from adhering to the first inclined portion 33 or the second inclined portion 34, blocking the toner transport path 27, and preventing the waste toner from being stored in the toner recovery container 23.

[0046] The present invention is not limited to the above-described embodiment, and various modifications are possible without departing from the spirit of the present invention. For example, the present invention is not limited to the tandem type color image forming apparatus shown in Fig. 1, and can be applied to various image forming apparatuses having a waste toner recovery mechanism, such as rotary type color copiers and printers, monochrome copiers, monochrome printers, digital multifunction machines, and facsimiles. [Industrial Applicability]

[0047] By installing the toner recovery device of the present invention, an image forming apparatus can replace the toner recovery container at the appropriate time, thereby reducing the frequency of replacing the toner recovery container and suppressing the backflow of waste toner. [Explanation of symbols]

[0048] 1a to 1d Photoconductor drum (toner carrier) 21 Toner recovery device 23 Toner collection container 25 Waste toner transport unit (waste toner transport section) 27 Toner transport path 28 Side wall 29 Detection recess 30 Detection Sensor 31 Toner collection port 32 Outlet 33 1st slope part 34 2nd slope part 35 Bottom 36 Third slope 39 Light-emitting part 40 Light receiving part 100 Image forming device Pa~Pd Image forming section S Paper (recording medium)

Claims

1. a toner recovery container formed with a toner recovery port into which waste toner on a toner carrier is poured and capable of containing the waste toner poured from the toner recovery port; a toner transport path including: a first inclined portion that is provided immediately below the toner recovery port and extends leftward in a left-right direction perpendicular to the up-down direction; and a second inclined portion that is connected to a lower end of the first inclined portion and extends forward in a front-rear direction perpendicular to the up-down direction and the left-right direction, the second inclined portion having a downward slope and a left side end that abuts against an inner wall surface on the left side of the toner recovery container, the toner transport path transporting the waste toner input from the toner recovery port along the first inclined portion and the second inclined portion toward a bottom of the toner recovery container; a side wall portion connected to a right side end portion of the second inclined portion in the left-right direction and rising upward in the up-down direction from the right side end portion of the second inclined portion; a detection recess having an opening between an upper end of the side wall portion and an inner wall surface on the right side of the toner recovery container, the detection recess extending from the opening to a rear side in the front-rear direction and communicating with the rear side of the second inclined portion; a detection sensor that detects the presence or absence of the waste toner at a predetermined position in the vertical direction inside the detection recess; Equipped with The detection sensor includes: a light-emitting unit disposed on one side of the detection recess in the left-right direction; A light receiving unit disposed on the other side; a light sensor that detects the presence or absence of the waste toner between the light emitting portion and the light receiving portion based on a light receiving state of the light receiving portion.

2. 2. The toner recovery device according to claim 1, wherein the side wall portion has a third inclined portion that slopes downward from an upper end of the side wall portion toward the left.

3. 3. The toner recovery device according to claim 1, wherein an inclination angle of the first inclined portion and an inclination angle of the second inclined portion are larger than an angle of repose of the waste toner.

4. an image forming section having the toner carrier and forming an image on a recording medium; a waste toner transport unit that transports the waste toner on the toner carrier to the toner recovery port; The toner recovery device according to claim 1 , which recovers the waste toner transported by the waste toner transport unit; An image forming apparatus comprising:

Images