JP5376975B2 - Image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image forming apparatus capable of inexpensively collecting used developer by using an inexpensive collection container without deviating it in the collection container. <P>SOLUTION: The collection container 12 is detachably attached to an upper cover 16 fixed to a collected toner pipe 14. A discharge tube 15 is rotatably attached relative to the upper cover 16 while communicating with the collected toner pipe 14. A control unit 21 controls a DC servomotor 18 to rotate the discharge tube 15 in the collection container 12 so as to discharge the used toner with centrifugal force from an opening 15a. <P>COPYRIGHT: (C)2010,JPO&amp;INPIT

Description

  The present invention relates to an image forming apparatus that accumulates used developer collected in an image forming unit in a collection container and takes out the entire collection container, and more particularly to a mechanism for depositing used developer in the collection container without bias.

  Practical use of an image forming device that collects used developer collected in the image forming section by screw conveyance with a conveyance pipe equipped with a screw member, drops and accumulates in the collection container, and takes out and discards the collection container when the collection container is full (Patent Document 1). Examples of the used developer are residual transfer toner collected from the photoreceptor, deteriorated carrier collected from the developing device, and the like.

  In such an image forming apparatus, when a collecting container having a large bottom area is used, the used developer is biased toward a part of the collecting container, and it may be determined that the collecting container is full in a state far from being full.

  For this reason, a mechanism for depositing a used developer in the collection container without any bias has been proposed (Patent Documents 2 and 3).

  Patent Document 2 discloses a collection container rotating mechanism in which a used developer accumulated in the center by rotating a cylindrical collection container at high speed is broken outward by centrifugal force.

  In Patent Document 3, a used developer dropping port is provided at a position away from the center of rotation of a cylindrical collection container, and the collection position of the used developer on the bottom surface of the collection container is moved by rotating the collection container at a low speed. A recovery container rotation mechanism is shown.

JP 09-212053 A Japanese Patent Laid-Open No. 01-233473 JP 05-333749 A

  The residual toner collected from the photoconductor is difficult to flow because the carrier and additives that have been given fluidity are lost in addition to the small centrifugal force acting on the particles because of their small mass. . Further, the transfer residual toner conveyed so as to be kneaded using a screw member may fall into a collection container in a state where a part of the toner is melted and solidified into a block shape.

  For this reason, as shown in Patent Document 1, as much as the collection container is rotated, the toner deposited near the center cannot be diffused into the collection container. However, if the toner is rotated at a high speed, the accumulated toner is displaced to a part of the outer side and collapses, and abnormal vibration of the collection container due to the deviation of the center of gravity occurs.

  On the other hand, as shown in Patent Document 2, when the collection container is rotated to move the accumulation position on the bottom surface, the used developer that is difficult to flow can be evenly dispersed and accumulated in the collection container.

  However, since the used developer is deposited directly under the dropping port, the diameter of the opening of the collection container is increased so as to ensure the movable range of the dropping port. When the aperture diameter increases, the manufacturing cost of the collection container including the lid increases, and the used developer that scatters outside when the full collection container is taken out also increases. There is also a problem that considerable power consumption is required to keep rotating the collecting container that becomes heavier as the used developer is accumulated.

  An object of the present invention is to provide an image forming apparatus capable of collecting a used developer at a low cost by using a low-cost collection container without causing the developer to be displaced in the collection container.

An image forming apparatus according to the present invention includes an image forming unit that forms an image using toner, a detachable collection container that has an opening facing upward, and a used developer collected by the image forming unit. And a transport path for guiding the developer to the opening, and the used developer falls and accumulates in the collection container. And it is arranged to communicate with the transport path so that the opening faces the inner wall surface of the collection container, and rotates in the collection container so as to change the accumulated position of the used developer in the collection container. A pipe member capable of dropping the used developer delivered from the transport path to the outside of the opening just below the opening by centrifugal force, and an increase in the amount of used developer accumulated in the collection container And a control means for controlling the rotation speed of the tube member so that the rotation speed of the tube member becomes slow .

  In the image forming apparatus of the present invention, the used developer collected by the image forming unit is conveyed to a removable collection container through a conveyance path, and the deposition position is shifted in the collection container by a rotating member that rotates in the collection container. To fall.

  For this reason, it is possible to disperse and deposit the used developer in the collection container even if a general bottle-shaped collection container having a relatively small opening is used without rotating the collection container itself.

  Therefore, it is possible to collect the used developer at a low cost by using a low-cost collection container without shifting the developer in the collection container.

It is explanatory drawing of a structure of the image forming apparatus of 1st Embodiment. It is explanatory drawing of the structure of the used toner collection | recovery apparatus of a comparative example. It is explanatory drawing of the full state of the collection container in a comparative example. FIG. 3 is an explanatory diagram of a configuration of a used toner collection device according to the first exemplary embodiment. FIG. 6 is an explanatory diagram of a toner accumulation state when the rotation speed is low. FIG. 6 is an explanatory diagram of a toner accumulation state when the rotation speed is high. FIG. 6 is an explanatory diagram of a toner accumulation state when the rotation speed is alternately switched. FIG. 10 is an explanatory diagram of a configuration of a used toner collecting device according to a second embodiment. 6 is an explanatory diagram of a toner accumulation state in the control of Embodiment 2. FIG.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. The present invention provides another embodiment in which part or all of the configuration of the embodiment is replaced with the alternative configuration as long as the used developer is discharged and accumulated in the collection container with a centrifugal force. But it can be done.

  The used developer collected in the collection container may be any of a one-component developer, a two-component developer, and a nonmagnetic toner for replenishment. The image forming apparatus is not limited to the monochrome image forming apparatus shown in FIG. 1, but may be an intermediate transfer type or direct transfer type full color image forming apparatus.

  In the present embodiment, only main parts related to toner image formation / transfer will be described. However, the present invention includes a printer, various printing machines, a copier, a fax machine, a composite machine, in addition to necessary equipment, equipment, and a housing structure. It can be implemented in various applications such as a machine.

  In addition, about the general matter regarding the image forming apparatus and the fixing apparatus disclosed in Patent Documents 1 to 3, illustration is omitted and redundant description is omitted.

<Image forming apparatus>
FIG. 1 is an explanatory diagram of a configuration of the image forming apparatus according to the first embodiment.

  As shown in FIG. 1, the image forming apparatus A is a monochrome printer that forms a toner image on the photosensitive drum 7 of the image forming unit 9 and transfers the toner image to the recording material 2.

  The recording material P taken out from the recording material cassette 3a using the pickup roller 3b is separated one by one and fed to the registration roller 3c. The registration roller 3 c waits for the recording material P, and sends the recording material 2 to the transfer unit in synchronization with the toner image on the photosensitive drum 7. The recording material 2 to which the toner image is transferred by the transfer unit is nipped and conveyed by the fixing device 5 to the fixing nip, and the toner image is fixed on the surface.

  A charging roller 8, an exposure device 1, a developing device 10, a transfer roller 4, and a cleaning device 11 are disposed around the photosensitive drum 7.

  The charging roller 8 is applied with an oscillating voltage obtained by superimposing an AC voltage on a DC voltage from a power source (not shown), and charges the surface of the photosensitive drum 7 to a uniform negative potential.

  The exposure apparatus 1 scans a laser beam that is ON-OFF modulated in accordance with an image signal obtained by developing image data, and writes an electrostatic image of the image on the surface of the photosensitive drum 7.

  In the developing device 10, a toner hopper 10a is filled with a toner T1 as a one-component developer. The developing device 10 supplies the toner T1 carried on the developing sleeve 10b in a thin layer state to the electrostatic image on the photosensitive drum 7 in a state where the toner T1 is rubbed by the developing blade 10c and charged negatively. By applying an oscillating voltage in which an AC voltage is superimposed on a DC voltage from a power source (not shown) to the developing sleeve 10b, the toner T1 is transferred to the exposed portion of the photosensitive drum 7 having a relatively positive polarity, and electrostatic The image is reversal developed.

  The transfer roller 4 is pressed against the photosensitive drum 7 to form a transfer portion, and sandwiches and conveys the recording material 2 over the toner image carried on the photosensitive drum 7. A toner image is transferred from the photosensitive drum 7 to the recording material 2 by applying a positive DC voltage to the transfer roller 4 from a power source (not shown).

  The cleaning device 11 slides the cleaning drum 11a on the photosensitive drum 7 to remove used toner (transfer residual toner) T2 remaining on the surface of the photosensitive drum 7 that has passed through the transfer portion.

  The fixing device 5 forms a fixing nip for a recording material by pressing a pressure roller 5b against a fixing roller 5a provided with a heater inside.

<Used toner collection device>
In the image forming apparatus A, after the toner image formed on the photosensitive drum 7 is transferred to the recording material 2, it remains on the photosensitive drum 7 using the cleaning device 11 so as not to hinder the next image formation. Transfer residual toner is removed. Then, the used toner collecting device B collects the toner in the removable collection container 12 through the conveyance path.

  The used toner T2 scraped off from the photosensitive drum 7 by the cleaning blade 11a is temporarily stored in the cleaning container 11b and is transported in the direction perpendicular to the paper surface by the transport screw 11c. The used toner T2 collected at one end (front side) in the longitudinal direction of the cleaning device 11 by the transport screw 11c is collected in a removable collection container 12 through the transport path of the used toner collection device B (B0 to B2). The

  The collection container 12 is finished by blow molding PTT resin into a cylindrical bottle shape having a wide opening. As will be described later, the cylindrical portion has a diameter of 150 mm, a height of 150 mm, and is designed to accommodate 1000 g of used toner in a full state.

<Comparative example>
FIG. 2 is an explanatory diagram of a configuration of a used toner recovery device of a comparative example, and FIG. 3 is an explanatory diagram of a full state of a recovery container in the comparative example.

  As shown in FIG. 2, in the used toner collection device B0 of the comparative example, the collection container 12 is integrally formed as a whole by arranging an opening 12a having a smaller diameter than the cylindrical side surface at the center of the upper bottom surface of the cylindrical side surface. It is the appearance shape of a general resin bottle. An upper lid 16 that is fitted and sealed to the opening 12a of the collection container 12 is connected to the end of the collection toner pipe 14 that is an example of the conveyance path. The collection toner pipe 14 is connected to the opening 12a of the collection container 12. It is arranged on the central axis.

  The collection container 12 is formed using a transparent resin material, and a light receiving element 25b that receives infrared light from the light emitting element 25a is provided on a side surface of the collection container 12 so as to face the light emitting element 25a that emits infrared light. Has been placed.

  The controller 21 detects the output of the light emitting element 25a and determines whether the used toner in the collection container 12 is full. When the amount of light received by the light emitting element 25a decreases, it is determined that the used toner accumulated in the collecting container 12 has blocked the output optical path of the light emitting element 25a, and a warning that the used toner in the collecting container 12 is full. The display is displayed on the operation panel 22.

  In the used toner collecting apparatus B0 of the comparative example, the used toner conveyed by the conveying screw 13 falls into the collecting container 12 through the collected toner pipe 14 as the conveying screw 13 rotates inside the collected toner pipe 14. . When the toner falls directly into the collecting container 12 from the collecting toner pipe 14, the used toner accumulates in a hill shape with the dropping position as a vertex.

  For this reason, the used toner T2 accumulates in a hill shape immediately below the discharge port of the collection container 12. Then, when the top portion blocks the output optical path of the light emitting element 25a, the control unit 21 displays a warning display on the operation panel 22 that the used toner in the collection container 12 is full.

  Accordingly, the fullness of the collection container 12 is determined in a state where there is sufficient storage space for the used toner in the collection container 12, and the collection container 12 needs to be replaced earlier than the original full state. Specifically, when the collection container 12 is full and can store about 1000 g of used toner, if the used toner accumulates in a hill shape with the drop position at the top, only about 700 g is stored before it is judged full. Can not. That is, the used toner collecting device B0 of the comparative example cannot store as much toner as possible in the collecting container 12 having a limited volume.

<Example 1>
4 is an explanatory diagram of a configuration of the used toner collecting apparatus according to the first embodiment, FIG. 5 is an explanatory diagram of a toner accumulation state when the rotation speed is low, and FIG. 6 is an explanatory diagram of a toner accumulation state when the rotation speed is high, FIG. 7 is an explanatory diagram of the toner accumulation state when the rotation speed is alternately switched.

  As shown in FIG. 4, the used toner collecting device B1 of Example 1 rotates the discharge tube 15 so that the tip of the discharge tube 15 which is an example of a tube member circulates in the collection container 12. As a result, the used toner reaches the outside of the tube member directly below the opening of the tube member by centrifugal force, and is dispersed and accumulated in the collection container 12.

  The recovery toner pipe 14 communicates the cleaning container (11b: FIG. 1) and the recovery container 12 so that the used toner does not leak to form a conveyance path. The conveying screw 13 disposed in the collected toner pipe 14 rotates as a screw member in the conveying path, and the used toner in the cleaning container (11b: FIG. 1) is screwed to the collecting container 12.

  The conveying screw 13 is formed by forming a wire-like metal in a spiral shape, and drives a drive gear 13a fixed to one end by a DC servo motor 13b to convey used toner along the collected toner pipe 14. To do.

  The recovered toner pipe 14 is fixed to the upper lid 16 with the upper lid 16 being penetrated. The upper lid 16 is fitted and sealed to the opening 12a of the collection container 12 through a seal member (not shown). Since the upper lid 16 and the collection container 12 are connected by a close fitting form such as screwing, the collection container 12 can be detached with the upper lid 16 left on the collection toner pipe 14 side.

  A discharge pipe 15 communicates with an end portion of the collected toner pipe 14 penetrating the upper lid 16 and is attached to be relatively rotatable. The discharge pipe 15 is formed by bending smoothly so that the tip thereof faces the cylindrical side surface of the collection container 12, and is fitted and fixed to a rotating member 17 having a tooth portion formed on the outer periphery. The rotating member 17 is assembled by being rotatably fitted in the collecting toner pipe 14 inside the collecting container 12.

  A driving gear 19 fixed to the output shaft of the DC servo motor 18 is meshed with the teeth on the outer periphery of the rotating member 17.

  The control unit 21 controls the DC servo motor 18 via the drive circuit 20 to rotate the rotating member 17 inside the collection container 12. The rotating member 17 rotates at a speed appropriately controlled by the rotation of the DC servo motor 18.

  On the cylindrical side surface of the collection container 12, a light emitting element 25a and a light receiving element 25b for detecting a full state of the used toner are obtained by blocking the optical path with the used toner collected and accumulated in the transparent collection container 12. Is arranged.

  As described above, when the amount of light received by the light emitting element 25a decreases, the control unit 21 displays a warning display on the operation panel 22 that the used toner in the collection container 12 is full.

  As shown in FIG. 5, the pipe member (15) drops the used developer to the outside of the part directly below the opening by centrifugal force. The discharge tube 15 rotates about the rotation axis O of the rotating member 17, and the opening 15 a of the discharge tube 15 circulates at a position away from the rotation axis O by a distance r.

  For this reason, the discharge tube 15 drops the used toner T2 into the collection container 12 so as to form a deposition center at a radius that does not coincide with the rotation axis O of the rotation member 17.

Here, the mass of the toner particles is m, the distance from the rotation center of the collection container 12 to the opening 15a is r, and the angular velocity of rotation of the discharge tube 15 is ω. At this time, the centrifugal force F acting on the toner particles is expressed by the following equation.
F = mrω ²

  Since r = r1 at the opening 15a of the discharge tube 15, a large centrifugal force F is applied to the toner particles, which are fine particles, so as to reach the inner wall surface of the collection container 12 even at a relatively low rotational speed. Is possible.

  In other words, the distance r1 is a rotation axis that allows the used toner T2 present at the tip of the discharge tube 15 to receive a sufficient centrifugal force from the rotational movement of the discharge tube 15 when discharged through the opening 15a. The distance from O. In Example 1, the radius r of the bottom surface of the collection container 12 was 75 mm, whereas the distance r was 25 mm.

  As shown in FIG. 5, when the angular velocity ω of rotation of the discharge tube 15 is small (low angular velocity ω0), the centrifugal force applied to the used toner T2 discharged from the opening 12a becomes minute. For this reason, the used toner T2 falling from the opening 12a is accumulated as a mountain-shaped used toner T2 having a recess centered on the rotation axis O.

  Therefore, compared to the comparative example shown in FIG. 2, the used toner T2 is diffused to some extent in the container body 12, and this alone reduces the problem of uneven deposition of the used toner T2.

  As shown in FIG. 6, when the angular velocity ω of rotation of the discharge tube 15 is high (high angular velocity ω1), the centrifugal force applied to the used toner T2 discharged from the opening 12a increases. Therefore, the used toner T2 falling from the opening 12a is diffused in a direction away from the rotation axis O, and is accumulated as a concave used toner T2 that is inclined toward the center with the vicinity of the inner wall surface of the collection container 12 as a vertex. .

  Therefore, the uneven deposition of the used toner T2 in the container body 12 changes according to the angular velocity ω of the rotation of the discharge tube 15, and the uneven deposition can be reduced by controlling the angular velocity ω.

  In the first embodiment, the control unit 21 controls on / off switching of the rotation of the discharge tube 15 and change of the angular velocity ω according to the operation state of the image forming apparatus (A: FIG. 1) and the accumulated usage time of the container body 12. To do.

  The controller 21 accumulates and counts the number of images formed immediately after the collection container 12 is replaced. The controller 21 intermittently switches the angular velocity ω of rotation of the discharge tube 15 between the low angular velocity ω0 (360 degrees / sec) and the high angular velocity ω1 (1440 degrees / sec) according to the cumulative number of image formations. Take control. The radius of the deposition center of the used developer is shifted by alternately switching the rotation speed of the tube member.

  Specifically, immediately after the collection container 12 is replaced, every time 1000 image formations are accumulated, the angular velocity ω of the rotation of the discharge tube 15 is switched alternately between the low angular velocity ω0 and the high angular velocity ω1. .

  Applying such control, image formation of 20000 sheets was performed, and the accumulated state of the used toner T2 in the collection container 12 was examined, and as shown in FIG.

  As shown in FIG. 7, the used toner T2 in the collection container 12 was diffused more uniformly than in the case of using a single angular velocity ω as shown in FIGS. That is, the accumulation amount deficient region near the inner wall surface when rotated at the low angular velocity ω0 shown in FIG. 5 is offset by the excessive accumulation amount region near the inner wall surface when rotated at the high angular velocity ω1 shown in FIG. .

  In the first embodiment, the DC servo motor 18 is used as means for driving the discharge tube 15 to rotate. However, a control for intermittently rotating the discharge tube 15 using a stepping motor may be employed.

  According to the configuration and control of the first embodiment, the used toner can be uniformly deposited in the collection container 12 as shown in FIG. 7 without being inclined and deposited in a hill shape as shown in FIG. Become.

  Accordingly, the recovery container 12 is not judged to be full when there is sufficient storage space for the used toner in the recovery container 12, and the recovery container 12 can be replaced in the original full state. It is possible to store as much toner as possible in the collection container 12 whose capacity is limited.

<Example 2>
FIG. 8 is an explanatory diagram of the configuration of the used toner collecting apparatus of the second embodiment, and FIG. 9 is an explanatory diagram of the toner accumulation state in the control of the second embodiment.

  As shown in FIG. 8, in the used toner collecting device B2 of the second embodiment, the rotation driving and the rotation control of the discharge tube 15 are different from those of the first embodiment. Since the other parts are the same as those in the first embodiment, the same reference numerals as those in FIG. 4 are given to the components common to the first embodiment in FIG.

  As shown in FIG. 4, in Example 1, the discharge tube 15 was rotationally driven using a dedicated DC servo motor 18, and the angular velocity of rotation of the discharge tube 15 was switched alternately in two stages.

  As shown in FIG. 8, in the second embodiment, the discharge pipe 15 is connected to the conveying screw 13 and is integrally rotated, and the angular velocity of the rotation of the discharge pipe 15 is largely controlled according to the toner accumulation amount in the collection container 12. Is done.

  The discharge pipe 15 is assembled to the upper lid 16 so as to be rotatable, and communicates with a collected toner pipe 14 having a lower end fixed to the upper lid 16.

  The discharge pipe 15 is coupled to an end portion of the conveying screw 13 penetrating the upper lid 16 via a joining member 23. The joining member 23 transmits the rotational force of the transport screw 13 to the discharge pipe 15 to rotate the discharge pipe 15 and the transport screw 13 integrally. Therefore, even if a special drive source is not provided for driving the discharge tube 15, when the conveying screw 13 is rotated, the discharge tube 15 rotates together to diffuse and accumulate the used toner in the collection container 12. .

  The control unit 21 controls the drive motor 24 of the transport screw 13 via the drive circuit 20 to rotate the transport screw 13 at an appropriately controlled angular velocity ω.

  The control unit 21 determines the cumulative amount of used toner collected by the cleaning device (11: FIG. 1) based on the cumulative number of images formed immediately after the collection container 12 is replaced (the amount of toner accumulated in the collection container 12). Predicted value). Then, the angular velocity ω of rotation of the discharge tube 15 is changed according to the calculated accumulated amount of used toner.

  As shown in Table 1, the control unit 21 switches the angular velocity ω of the rotation of the discharge tube 15 according to the toner accumulation amount in the collection container 12 predicted based on the cumulative number of image formations.

As shown in Table 1, the angular velocity ω of the rotation of the discharge pipe 15 is increased every time the predicted value increases by 200 g from immediately after the collection container 12 is replaced until the predicted value of the toner accumulation amount reaches 800 g, which is almost full. Decrease by 360 (degrees / sec). In the second embodiment, the collection container 12 is full and can store about 1000 g of used toner.

  While the amount of accumulated toner in the collection container 12 is small, the discharge tube 15 is rotated at a large angular velocity ω, and the used toner T2 is deposited by shifting toward the inner wall surface in the collection container 12 as shown in FIG. .

  Thereafter, as the amount of accumulated toner in the collection container 12 increases, the angular velocity ω of the rotation of the discharge tube 15 is decreased, and the used toner is moved toward the center side in the collection container 12 as shown in FIG. T2 is deposited.

  Then, after the predicted value of the toner accumulation amount in the collection container 12 reaches 800 g or more, the angular velocity ω of the rotation of the discharge tube 15 is reduced to 180 (degrees / sec) to the accumulation amount limit of 1000 g. Decrease the centrifugal force.

  As shown in FIG. 9, the used toner having only a small centrifugal force is deposited so as to fill the concave portion of the concave recovery toner T2 centering on the rotation axis O and accommodates more used toner. it can.

  Specifically, according to the second embodiment, when the collection container 12 is full and can store about 1000 g of used toner, the used toner can be stored up to 980 g before the full load determination is made. In addition, without using the dedicated DC servo motor 18 as in the first embodiment, the used toner can be actively dispersed in the collection container 12 and can be uniformly deposited in a low-cost configuration.

  In the configuration described above, the discharge position of the used developer supplied through the opening 12a is changed so that the discharge pipe 15 which is an example of the moving discharge mechanism changes the deposition position of the used developer in the collection container 12. Is moved in the collection container 12. The discharge tube 15, which is an example of a toner guide member, is rotated with the gravity direction as the rotation axis O, and the opening 15 a of the discharge tube 15 is provided at a position that does not coincide with the rotation axis O in the collection container 12.

  Then, by dropping the used toner from the opening 15a while rotating the discharge tube 15, the effect of diffusing the used toner in the collection container 12 is enhanced, and high-density filling is possible.

  Further, since only the very light discharge tube 15 is rotated, the power consumption required for the rotation drive of the discharge tube 15 is low, the drive motor can be small, and it can be shared with the drive of the conveying screw 13, and noise and vibration can be shared. Does not occur.

  In addition, by adjusting the rotation speed of the discharge tube 15, the accumulated state of the used toner in the collection container 12 can be made uniform.

  In the first and second embodiments, the shape of the recovery container 12 is a cylindrical shape with a circular bottom surface, but the present invention can be applied regardless of the container shape.

<Example 3>
In both Example 1 and Example 2, the upper lid 16 of the recovery container 12 was fixed to the recovery toner pipe 14. That is, after the rotating member is disposed on the image forming apparatus (A: FIG. 1) side and the collection container filled with used toner is taken out, the upper lid 16 including the discharge tube 15 is moved to the image forming apparatus (A: FIG. 1). 1) Remained on the side.

  As shown in FIG. 8, in Example 3, the collection container 12 with the upper lid 16 screwed on is removed from the image forming apparatus A. A pipe connector that allows the discharge pipe 15 and the recovered toner pipe 14 to be detachably connected to each other is provided on the upper cover 16, and a rotary connection structure that transmits the rotation of the conveying screw 13 to the discharge pipe 15 is incorporated in the pipe connector.

  Specifically, a pin groove having an open upper end is formed on the inner wall surface of the discharge pipe 15 so that the pin rotating integrally with the conveying screw 13 can be extracted upward.

A Image forming apparatus B Used toner collecting device T1 Toner T2 Used toner O Rotating axis 1 Exposure device 2 Recording material 3 Paper feed mechanism 3a Recording material cassette 3b Pickup roller 3c Registration roller 4 Transfer roller 5 Fixing device 5a Fixing roller 5b Addition Pressure roller 6 discharge tray 7 photosensitive drum 8 charging roller 10 developing device 10a toner hopper 10b developing sleeve 10c developing blade 11 cleaning device 11a cleaning blade 11b cleaning container 12 recovery container 13 transport screw 14 recovery toner pipe 15 discharge pipe 16 upper lid 17 rotating member 18 DC servo motor 19 Drive gear 20 Drive circuit 21 Control unit 22 Operation panel 23 Joining member 24 Drive motor 25a Light emitting element 25b Light receiving element

Claims (4)

An image forming unit that forms an image using toner, a detachable collection container that is disposed with the opening facing upward, and a conveyance path that guides the used developer collected by the image forming unit to the opening. In an image forming apparatus in which a used developer drops and accumulates in the collection container,
It is arranged to communicate with the transport path so that the opening faces the inner wall surface of the collection container, and rotates in the collection container so as to change the accumulated position of the used developer in the collection container, A pipe member capable of dropping the used developer delivered from the conveyance path to the outside of the opening just below the opening by centrifugal force;
An image forming apparatus comprising: a control unit configured to control the rotation speed of the tube member so that the rotation speed of the tube member becomes slow as the amount of used developer accumulated in the collection container increases . Comprising a screw member which rotates to screw transporting the spent developer in said conveying path, said tube member, an image forming apparatus according to claim 1, wherein the rotating integrally coupled to the screw member . Said tube member, an image forming apparatus according to claim 1 or 2, wherein the drawn off from the collecting vessel through the opening with the detachable for replacement of the collection container. It said tube member, an image forming apparatus according to claim 1 to 3 any one of claims, characterized in that it is separated from the transport path to the collection container integrally with the removable for replacement of the collection container.

Images