Image forming apparatus

Abstract

To provide a developer collecting device that can reduce leakage or scattering of a collected developer in a configuration in which the collected developer is selectively collected to a plurality of collected developer containers, and to provide an image formation device including the developer collecting device.SOLUTION: A developer collecting device 1 comprises: a vertical conveyance part 41; a lateral conveyance part 42; a conveyance member 43 that conveys a collected developer inside the lateral conveyance part 42, the conveyance member 43 including a spiral-shaped part rotating in a first direction around a rotation axis along an elongated direction of the lateral conveyance part 42 to convey the collected developer in a direction from a second end part side (a right side end part) toward a first end part side (a left side end part), and rotating in a second direction opposite the first direction around the rotation axis to convey the collected developer in a direction from the first end part side toward the second end part side; and a drive unit 5 that can rotatingly drive the conveyance member 43 in the first direction and second direction.SELECTED DRAWING: Figure 5

Description

[Technical field]

[0001] The present invention relates to a developer recovery device used in an image forming apparatus such as a copying machine, a printer, a facsimile machine, or a multifunction machine having multiple functions thereof, which uses an electrophotographic method or an electrostatic recording method, and to an image forming apparatus equipped with the developer recovery device. [Background technology]

[0002] Conventionally, in an image forming apparatus such as a copying machine using an electrophotographic method, a toner image formed by an electrophotographic image forming process on a photoconductor as an image carrier using a developer containing a toner is transferred to a transferee such as a recording material. The toner (transfer residual toner) remaining on the photoconductor when the toner image is transferred from the photoconductor to the transferee is removed from the photoconductor by a cleaning means, transported to a recovered developer container as a recovered developer by a developer recovery device, and accumulated inside the recovered developer container. Then, the recovered developer container is replaced with an empty recovered developer container when the inside of the recovered developer container becomes full with recovered developer. Conventionally, generally, when replacing the recovered developer container, it is necessary to stop the image forming operation of the image forming apparatus in order to stop the transport of the recovered developer by the developer recovery device. Therefore, for example, in a business in which continuous large-volume printing is desired, there is a problem that productivity decreases due to replacement of the recovered developer container.

[0003] In response to this problem, a configuration has been proposed in which two recovered developer containers are detachably provided in the main body of an image forming apparatus, and the recovered developer is selectively discharged from one of two discharge sections that discharge the recovered developer to each of the recovered developer containers (Patent Document 1). In the configuration described in Patent Document 1, an agitating member having a plurality of wings radially provided on a rotating shaft is disposed in an agitating tank into which the recovered developer is fed, and a plurality of chambers for accommodating the recovered developer are formed by the plurality of wings. The agitating member rotates so that the plurality of chambers of the agitating tank pass sequentially through two openings provided in the agitating tank so as to communicate with the two discharge sections, respectively, and the recovered developer is discharged from the agitating tank. When the recovered developer is discharged from the right discharge section of the two discharge sections arranged side by side in the left-right direction, the agitating member rotates in a clockwise direction, and when the recovered developer is discharged from the left discharge section, the agitating member rotates in a counterclockwise direction. According to this configuration, when replacing one of the recovered developer containers, if the recovered developer can be recovered in the other recovered developer container, one of the recovered developer containers can be replaced without stopping the image formation operation. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2008-83102 A Summary of the Invention [Problem to be solved by the invention]

[0005] However, in the configuration described in Patent Document 1, the stirring member rotates clockwise or counterclockwise so that the multiple chambers of the stirring tank pass through the two openings of the stirring tank in sequence, and the recovered developer is selectively discharged from the right-side discharge part or the left-side discharge part. In other words, the multiple chambers of the stirring tank move so as to pass not only through the opening that communicates with the discharge part that is currently discharging the recovered developer, but also through the opening that communicates with the discharge part that is not currently discharging the recovered developer.

[0006] Therefore, for example, when one of the recovered developer containers is removed, there is a high risk of the recovered developer leaking or scattering through the opening of the agitation tank corresponding to that recovered developer container. In the configuration of Patent Document 1, the opening of the agitation tank that communicates with the discharge part that is not currently discharging the recovered developer is closed by a shutter member, but as described above, there is still a high risk of the recovered developer leaking or scattering. In addition, if the leaking or scattering of the recovered developer is strictly prevented, the configuration of the shutter member will become complicated and large, which will lead to a complicated and large configuration of the image forming apparatus.

[0007] In the above, the recovered developer has been described as a transfer residual toner removed from a photoconductor, but the recovered developer generated in an image forming apparatus is not limited to this. For example, the recovered developer may be a transfer residual toner removed from an intermediate transfer body serving as a second image carrier that conveys a toner image primarily transferred from a photoconductor serving as a first image carrier to a recording material for secondary transfer. In addition, for example, the recovered developer may be a developer (which may include a toner and a carrier) discharged from a developing device that develops an electrostatic image formed on an image carrier.

[0008] Therefore, an object of the present invention is to provide a developer recovery device that can reduce the risk of leakage or scattering of recovered developer in a configuration in which recovered developer is selectively recovered into multiple recovered developer containers, and an image forming apparatus equipped with the same. [Means for solving the problem]

[0009] The above object is achieved by the developer recovery device and image forming apparatus according to the present invention. In summary, the present invention relates to a developer recovery device capable of transporting recovered developer discharged from an image forming unit that forms an image using developer to a first recovered developer container and a second recovered developer container, the developer recovery device comprising: a tubular vertical transport section that guides the recovered developer discharged from the image forming unit from above to below in the direction of gravity; and a tubular horizontal transport section that can guide the recovered developer transported through the interior of the vertical transport section toward the first recovered developer container and the second recovered developer container along a direction intersecting the direction of gravity, the tubular horizontal transport section having a first discharge port provided at a first end in the extension direction of the horizontal transport section and discharging the recovered developer, a second discharge port provided at a second end opposite to the first end in the extension direction of the horizontal transport section and discharging the recovered developer, and a tubular horizontal transport section that can guide the recovered developer transported through the interior of the vertical transport section toward the first recovered developer container and the second recovered developer container along a direction intersecting the direction of gravity, the first discharge port being provided at a first end in the extension direction of the horizontal transport section and discharging the recovered developer, This developer recovery device is characterized by having: a horizontal conveying section having an receiving port that is arranged between the first discharge outlet and the second discharge outlet in the longitudinal direction and receives the recovered developer from the vertical conveying section into the horizontal conveying section; a conveying member that conveys the recovered developer inside the horizontal conveying section, the conveying member having a spiral-shaped portion that conveys the recovered developer in a direction from the second end side to the first end side by rotating in a first direction about a rotation axis that is along the extension direction of the horizontal conveying section, and conveys the recovered developer in a direction from the first end side to the second end side by rotating in a second direction opposite to the first direction about the rotation axis; and a drive unit that is capable of rotating the conveying member in the first direction and the second direction.

[0010] According to another aspect of the present invention, there is provided an image forming apparatus having an image forming unit that forms an image using a developer, and in which a first recovered developer container and a second recovered developer container that accommodate recovered developer discharged from the image forming unit are each detachable, the image forming apparatus being characterized in having the developer recovery device of the present invention described above that is capable of transporting recovered developer discharged from the image forming unit to the first recovered developer container and the second recovered developer container. Effect of the Invention

[0011] According to the present invention, in a configuration in which recovered developer is selectively recovered into a plurality of recovered developer containers, it is possible to reduce the risk of the recovered developer leaking or scattering. [Brief description of the drawings]

[0012] [Figure 1] FIG. 1 is a schematic cross-sectional view of an image forming apparatus. [Diagram 2] 5A and 5B are schematic diagrams illustrating a manner in which a recovered developer is discharged from an image forming unit. [Diagram 3] FIG. 2 is a schematic perspective view of an image forming apparatus, illustrating a manner in which a recovered developer container is attached. [Figure 4] FIG. [Diagram 5] FIG. 2 is a perspective view of a developer recovery device. [Figure 6] 5 is a cross-sectional view taken along line XX in FIG. 4. [Figure 7] 5 is a cross-sectional view taken along line YY in FIG. 4. [Figure 8] 2 is a perspective view of a portion of the developer recovery device with the recovered developer container removed. FIG. [Figure 9] FIG. 4 is a perspective view of the developer recovery device for explaining a developer recovery operation. [Figure 10] FIG. 4 is a perspective view of the developer recovery device for explaining a developer recovery operation. [Figure 11] 5 is a schematic block diagram showing a control mode of the developer recovery device. FIG. [Figure 12] FIG. 11 is a flowchart showing an outline of a procedure of a developer collecting operation. [Figure 13] FIG. 13 is a perspective view of a developer recovery device according to another embodiment. [Figure 14] 14 is a cross-sectional view of the device of FIG. 13 taken along the line XX in FIG. 4. [Figure 15] 14 is a cross-sectional view of the device of FIG. 13 taken along the same line as YY in FIG. 4. [Figure 16] FIG. 14 is a perspective view showing a drive transmission unit of the device in FIG. [Figure 17] 14 is a perspective view for explaining a developer collecting operation in the device of FIG. 13. FIG. [Figure 18] 14 is a perspective view for explaining a developer collecting operation in the device of FIG. 13. FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0013] The developer recovery device and the image forming apparatus according to the present invention will be described in more detail below with reference to the drawings.

[0014] [Example 1] 1. Image forming equipment 1 is a schematic cross-sectional view (a cross-section substantially perpendicular to the direction of the rotation axis of a photosensitive drum 101 described later) of an image forming apparatus 100 of this embodiment. The image forming apparatus 100 of this embodiment is a tandem printer employing an intermediate transfer method that can form a full-color image using an electrophotographic method.

[0015] With respect to the image forming apparatus 100 and its elements, the front side of the paper in FIG. 1 is the "front" side, and the back side of the paper in FIG. 1 is the "rear" side. An operator such as a user or a service person usually operates the image forming apparatus 100 from the front side of the image forming apparatus 100. The front-rear direction of the image forming apparatus 100 is assumed to be approximately parallel to the rotation axis direction of the photosensitive drum 1 described later. With respect to the image forming apparatus 100 and its elements, the left side and the right side when viewed from the front side are respectively assumed to be the "left" side and the "right" side. With respect to the image forming apparatus 100 and its elements, the up-down direction refers to the up-down direction in the direction of gravity (vertical direction), but does not mean only directly above and directly below, but also includes the upper side and the lower side of a horizontal plane passing through the element or position of interest.

[0016] The image forming apparatus 100 has a first, second, third and fourth stations SY, SM, SC and SK as a plurality of image forming means, which form images of yellow (Y), magenta (M), cyan (C) and black (K), respectively. Elements having the same or corresponding functions or configurations in each station SY, SM, SC and SK may be generally described by omitting the suffixes Y, M, C and K of the reference numerals indicating that the elements are for any of the colors. In this embodiment, the station S is configured to include a photosensitive drum 101, a charging device 102, an exposure device 103, a developing device 104, a primary transfer roller 105 and a drum cleaning device 106, which will be described later. In this embodiment, a plurality of stations SY, SM, SC and SK (four in this embodiment) are arranged in a line along a direction intersecting the direction of gravity, particularly along a substantially horizontal direction in this embodiment.

[0017] The photosensitive drum 101, which is a rotatable drum-type photosensitive member (electrophotographic photosensitive member) serving as a first image carrier, is driven to rotate in the direction of the arrow R1 in the figure. In this embodiment, the four photosensitive drums 101 are arranged side by side in a substantially horizontal direction. The surface of the rotating photosensitive drum 101 is uniformly charged to a predetermined polarity (negative polarity in this embodiment) by a charging device 102 serving as a charging means. The surface of the charged photosensitive drum 101 is scanned and exposed according to image information by an exposure device (laser scanner) 103 serving as an exposure means, and an electrostatic image (electrostatic latent image) is formed on the photosensitive drum 101. The electrostatic image formed on the photosensitive drum 101 is developed (visualized) by the supply of toner by a developing device 104 serving as a developing means, and a toner image is formed on the photosensitive drum 101. In this embodiment, toner charged with the same polarity (positive polarity in this embodiment) as the charge polarity of the photosensitive drum 101 adheres to an exposed portion (image portion) on the photosensitive drum 101, which has been uniformly charged and then exposed to light, thereby decreasing the absolute value of the potential. In this embodiment, the normal charge polarity of the toner, which is the charge polarity of the toner during development, is negative polarity.

[0018] An intermediate transfer belt 107, which is an intermediate transfer body formed of an endless belt as a second image carrier, is disposed so as to face the four photosensitive drums 101. The intermediate transfer belt 107 is stretched around a driving roller 171, a tension roller 172, and a secondary transfer opposing roller 173 as a plurality of tension rollers (support rollers) and stretched with a predetermined tension. The intermediate transfer belt 107 rotates (moves in a circular motion) in the direction of an arrow R2 in the figure by transmitting a driving force as the driving roller 171 is driven to rotate. On the inner peripheral surface side of the intermediate transfer belt 107, a primary transfer roller 105, which is a roller-type primary transfer member as a primary transfer means, is disposed in correspondence with each photosensitive drum 101. The primary transfer roller 105 presses the intermediate transfer belt 107 toward the photosensitive drum 101 to form a primary transfer portion (primary transfer nip) N1 where the photosensitive drum 101 and the intermediate transfer belt 107 come into contact with each other. As described above, the toner images formed on the photosensitive drums 101 are primarily transferred onto the rotating intermediate transfer belt 107 at the primary transfer portion N1 by the action of the primary transfer rollers 105. During the primary transfer, a primary transfer voltage, which is a DC voltage of a polarity opposite to the normal charging polarity of the toner, is applied to the primary transfer rollers 105. For example, when a full-color image is formed, the toner images of each color, yellow, magenta, cyan, and black, formed on the photosensitive drums 101 are primarily transferred in sequence onto the intermediate transfer belt 107 so as to be superimposed on each other.

[0019] A secondary transfer roller 108, which is a roller-type secondary transfer member serving as a secondary transfer means, is disposed at a position facing the secondary transfer opposing roller 173 on the outer peripheral surface side of the intermediate transfer belt 107. The secondary transfer roller 108 is pressed toward the secondary transfer opposing roller 173 via the intermediate transfer belt 107, forming a secondary transfer portion (secondary transfer nip) N2 where the intermediate transfer belt 107 and the secondary transfer roller 108 come into contact with each other. The toner image formed on the intermediate transfer belt 107 as described above is secondarily transferred onto a recording material (recording medium, sheet) P such as a recording paper that is sandwiched and conveyed between the intermediate transfer belt 107 and the secondary transfer roller 108 in the secondary transfer portion N2. During secondary transfer, a secondary transfer voltage, which is a DC voltage of a polarity opposite to the normal charging polarity of the toner, is applied to the secondary transfer roller 108. The recording material P is accommodated in a cassette 111 serving as a recording material accommodation portion. The recording material P is supplied from the cassette 111 to the secondary transfer portion N2 by a recording material conveying device 112. The recording material conveying device 112 includes a pickup roller 112a, a feed roller 112b, a conveying roller 112c, and a registration roller 112d. The pickup roller 112a sends out the recording material P one by one from the cassette 111. The feed roller 112b and the conveying roller 112c convey the recording material P sent out from the cassette 111. The registration roller 112d temporarily stops the recording material P conveyed by the feed roller 112b and the conveying roller 112c, and sends out the recording material P to the secondary transfer section N2 so as to synchronize with the toner image on the intermediate transfer belt 107.

[0020] The recording material P onto which the toner image has been transferred is conveyed to a fixing device 113 as a fixing means. The fixing device 113 has a fixing roller 113a equipped with a heat source, and a pressure roller 113b that is in pressure contact with the fixing roller 113a. The fixing device 113 conveys the recording material P carrying an unfixed toner image while sandwiching it between the fixing roller 113a and the pressure roller 113b, thereby applying heat and pressure to the recording material P, thereby fixing (melting and bonding) the toner image onto the recording material P. The recording material P onto which the toner image has been fixed is discharged (output) by a discharge roller 114 onto a tray 115 provided outside the device body 110 of the image forming apparatus 100.

[0021] Furthermore, toner remaining on the photosensitive drum 101 without being transferred to the intermediate transfer belt 107 during the primary transfer (primary transfer residual toner) is removed from the photosensitive drum 101 and collected by a drum cleaning device 106 serving as a photosensitive body cleaning means. As shown in FIG. 2, the drum cleaning device 106 has a drum cleaning blade 161 formed of an elastic body serving as a cleaning member, and a drum cleaning container 162 serving as a toner collection section. The drum cleaning device 106 scrapes off the primary transfer residual toner from the surface of the rotating photosensitive drum 101 by the drum cleaning blade 161 arranged to abut against the surface of the photosensitive drum 101, and stores it inside the drum cleaning container 162.

[0022] Further, a belt cleaning device 109 serving as an intermediate transfer belt cleaning means is disposed at a position facing the tension roller 172 on the outer peripheral surface side of the intermediate transfer belt 107. Toner (secondary transfer residual toner) remaining on the intermediate transfer belt 107 without being transferred to the recording material P during secondary transfer is removed from the intermediate transfer belt 107 and collected by the belt cleaning device 109. The belt cleaning device 109 has a belt cleaning blade 191 formed of an elastic body as a cleaning member, and a belt cleaning container 192 as a toner collection section. The belt cleaning device 109 scrapes off secondary transfer residual toner from the surface of the rotating intermediate transfer belt 107 by the belt cleaning blade 191 disposed so as to abut against the surface of the intermediate transfer belt 107, and stores the toner inside the belt cleaning container 192.

[0023] The primary transfer residual toner contained in the drum cleaning container 162 is transported by a transport means (not shown) arranged inside the drum cleaning container 162. Then, this primary transfer residual toner is discharged from a drum cleaning container outlet 162a, which is an opening, and sent to a developer recovery device 1 (described later) as a recovered developer. Also, the secondary transfer residual toner contained in the belt cleaning container 192 is transported by a transport means (not shown) arranged inside the belt cleaning container 192. Then, this secondary transfer residual toner is discharged from a belt cleaning container outlet 192a, which is an opening, and sent to a developer recovery device 1 (described later) as a recovered developer.

[0024] In this embodiment, in each station S, the photosensitive drum 101 and the charging device 102, developing device 104, and drum cleaning device 106 acting on the photosensitive drum 101 as process means integrally constitute a process cartridge 117. The process cartridge 117 is configured so as to be pulled out to the front side of the image forming apparatus 100 and detachable from the apparatus main body 110. The process cartridges 117 for each color have substantially the same structure, except that the color of toner contained in the developing device 104 is different.

[0025] In this embodiment, the intermediate transfer belt 107, tension rollers 171 to 173 for the intermediate transfer belt 107, the primary transfer rollers 105, and the belt cleaning device 109 are integrated into an intermediate transfer unit 170. The intermediate transfer unit 170 is configured so as to be removable from the apparatus body 110 by being pulled out from the right side of the image forming apparatus 100.

[0026] The image forming apparatus 100 is also provided with toner cartridges 116Y, 116M, 116C, and 116K as supply developer containers that accommodate developers (supply developers) to be supplied to the developing devices 104Y, 104M, 104C, and 104K. The toner cartridges 116 are configured to be pulled out to the front side of the image forming apparatus 100 and detachable from the apparatus main body 110. The toner cartridges 116 for each color have substantially the same structure except for the colors of toner that are accommodated. The toner cartridges 116 have a supply developer accommodating section 116a that accommodates the supply developer, and a supply screw 116b that is a supply member that serves as a supplying means for supplying the supply developer in the supply developer accommodating section 116a to the developing device 104.

[0027] In this embodiment, the developing device 104 uses a two-component developer containing toner (non-magnetic toner particles) and carrier (magnetic carrier particles) as a developer. As shown in FIG. 2, the developing device 104 has a rotatable developing sleeve 141 as a developer carrier and a developing container 142 that contains the developer. The developing device 104 carries a developer containing toner and carrier on the developing sleeve 141, and conveys the developer to a developing position where the photosensitive drum 101 and the developing sleeve 141 face each other by the rotation of the developing sleeve 141. The developing device 104 forms a toner image on the photosensitive drum 101 by supplying the toner of the developer to the electrostatic image on the photosensitive drum 101 at the developing position. In addition, the developer contained in the developing container 142 and the replenished developer replenished from the toner cartridge 116 are circulated and conveyed while being stirred by a stirring and conveying means (not shown) arranged inside the developing container 142. In this embodiment, the supply developer supplied from the toner cartridge 116 to the developing device 104 contains toner and carrier. Then, the developer (which may contain toner and carrier) inside the developing container 142 that becomes excessive due to the supply of the supply developer is discharged from a developing container discharge port 142a, which is an opening, along with the circulating transport of the developer inside the developing container 142, and is sent to the developer recovery device 1, which will be described later, as recovered developer.

[0028] In this embodiment, each station S, the intermediate transfer unit 170, the secondary transfer roller 108, and the fixing device 113 constitute an image forming section G, which is a mechanism for forming an image on a recording material P using a developer. Note that Fig. 2 is a schematic diagram showing a manner in which recovered developer is discharged from the image forming section G (the drum cleaning device 106 and the developing device 104 of each station S, and the belt cleaning device 109).

[0029] 2. Developer waste container In this embodiment, two containers, the first and second recovered developer containers 10L and 10R, as a plurality of recovered developer containers are detachably attached to the device body 110 of the image forming device 100. In this embodiment, the first and second recovered developer containers 10L and 10R are arranged side by side in the substantially horizontal direction inside the device body 110. In particular, in this embodiment, the first and second recovered developer containers 10L and 10R have substantially the same structure and are arranged in parallel at substantially the same height in the vertical direction inside the device body 110. The recovered developer sent from the image forming section G to the developer recovery device 1 described later is selectively transported to and accumulated in one of the first and second recovered developer containers 10L and 10R. In this embodiment, as described above, the recovered developer is discharged from the drum cleaning device 106 and the developing device 104 of each station S, and the belt cleaning device 109 in the image forming section G. In addition, when the inside of either one of the first and second recovered developer containers 10L and 10R becomes full with recovered developer, the destination of the recovered developer is switched to the other container, and the one container is replaced with an empty container.

[0030] In addition, when the first and second recovered developer containers 10L, 10R are arranged side by side in a substantially horizontal direction, this also includes the first and second recovered developer containers 10L, 10R being arranged so that they overlap at least partially in the vertical direction.

[0031] The first and second recovered developer containers 10L and 10R are box-shaped containers having a predetermined length in the longitudinal direction and the lateral direction, a predetermined thickness (height) in the thickness direction, and a substantially rectangular cross section perpendicular to the longitudinal direction. The longitudinal direction is the direction along the front-rear direction of the image forming apparatus 100 inside the apparatus body 110. The lateral direction is the direction along the left-right direction of the image forming apparatus 100 inside the apparatus body 110. The thickness direction is the direction along the up-down direction inside the apparatus body 110. The first and second recovered developer containers 10L and 10R each have a hollow recovered developer storage section 11L or 11R (see FIG. 6 and FIG. 7) that stores the recovered developer formed therein. As described above, in this embodiment, the first and second recovered developer containers 10L and 10R have substantially the same structure, and each container can be mounted on either the left or right side inside the apparatus body 110. In this embodiment, the first collected developer container 10L is mounted on the left side inside the apparatus main body 110, and the second collected developer container 10R is mounted on the right side inside the apparatus main body 110.

[0032] FIG. 3 is a schematic external perspective view of the image forming apparatus 100 seen from the oblique front side to explain the mounting manner of the first and second collected developer containers 10L and 10R. FIG. 3(a) shows a state in which a container replacement door 118 described later is closed, and FIG. 3(b) shows a state in which the container replacement door 118 is opened and the first and second collected developer containers 10L and 10R can be attached and detached. On the front side of the image forming apparatus 110, a container replacement door 118 is provided which constitutes a part of the exterior cover of the image forming apparatus 100 and allows the first and second collected developer containers 10L and 10R to be attached and detached. In this embodiment, the container replacement door 118 is composed of one (common) opening and closing member which allows both the first and second collected developer containers 10L and 10R to be attached and detached. In this embodiment, the container replacement door 118 has a substantially rectangular shape which is long in the left-right direction when viewed from the front side. In this embodiment, the container replacement door 118 is configured to be rotatable about a rotation axis extending along the left-right direction intersecting with the up-down direction at the bottom of the door. The container replacement door 118 can be opened and closed by rotating the upper side of the door 118 about the rotation axis extending along the left-right direction at the lower side in the up-down direction by the operator.

[0033] As shown in FIG. 3(a), when the container replacement door 118 is closed, it has the appearance of a single panel that is equal in size in the left-right and up-down directions to the front panel 111a of the cassette 111 provided adjacently below it. Therefore, the appearance is prevented from becoming complicated due to the provision of two containers, the first and second collected developer containers 10L and 10R. In addition, by opening and closing the single container replacement door 118, both the first and second collected developer containers 10L and 10R can be attached and detached. Therefore, it is possible to prevent waste of operations caused by an operator opening and closing the wrong door, which may occur when a container replacement door is provided for each of a plurality of collected developer containers.

[0034] As shown in FIG. 3(b), by opening the container replacement door 118, an operator can access both the first and second collected developer containers 10L and 10R. The apparatus main body 110 is provided with first and second container mounting parts 119L and 119R to which the first and second collected developer containers 10L and 10R are respectively mounted. The first and second container mounting parts 119L and 119R have first and second container support parts 120L and 120R extending in the front-rear direction and supporting the lower sides of the first and second collected developer containers 10L and 10R, respectively. The first and second container mounting parts 119L and 119R have, for example, a rail-like structure (not shown) in which the first and second container support parts 120L and 120R engage with the first and second collected developer containers 10L and 10R, respectively. This allows the first and second recovered developer containers 10L, 10R to be slid from the front side to the rear side and easily disposed at a predetermined position inside the device main body 110. This also allows the first and second recovered developer containers 10L, 10R to be slid from the rear side to the front side and easily removed from the device main body 110 by pulling them out from a predetermined position inside the device main body 110.

[0035] As shown in FIG. 3(b), identification marks (identification marking portions) 121L and 121R are provided on the inner surface of the container replacement door 118 so that the operator can see them when the container replacement door 118 is open. The identification marks 121L and 121R are provided at positions corresponding to the first and second collected developer containers 10L and 10R in the left-right direction. In this embodiment, the left identification mark 121L is configured as a sticker on which characters such as "CONTAINER 1" (or "LEFT CONTAINER") are written to identify the first collected developer container 10L. In this embodiment, the right identification mark 121R is configured as a sticker on which characters such as "CONTAINER 2" (or "RIGHT CONTAINER") are written to identify the second collected developer container 10R. The identification marks 121L, 121R are provided to facilitate easy identification of the corresponding container when a display is displayed on the operation unit 130 (FIG. 11) of the image forming apparatus 100 to prompt the user to replace one of the collected developer containers 10L, 10R, as described below. In this embodiment, the identification marks 121L, 121R are provided on the inner surface of the container replacement door 118, but the present invention is not limited to this. The identification marks 121L, 121R may be provided, for example, on the front surface of a panel adjacent to each of the first and second container mounting portions 119L, 119R, corresponding to each of the first and second collected developer containers 10L, 10R.

[0036] 3. Structure of the developer recovery device Next, the configuration of the developer recovery device 1 in this embodiment will be described.

[0037] <Overall composition> Fig. 4 is a front view of the developer recovery device 1 of this embodiment as seen from the front. Fig. 5 is a perspective view of the developer recovery device 1 of this embodiment as seen from the diagonally front. Figs. 4 and 5 mainly show the recovered developer transport path 2 in the developer recovery device 1, and also show the first and second recovered developer containers 10L and 10R connected to the developer recovery device 1.

[0038] In this embodiment, the recovered developer transport path 2 of the developer recovery device 1 has, broadly speaking, an upstream transport section 3 and a downstream transport section 4. The upstream transport section 3 receives the recovered developer discharged from the image forming section G (the drum cleaning device 106 and the developing device 104 of each station S, and the belt cleaning device 109). The downstream transport section 4 receives the recovered developer from the upstream transport section 3, and transports the recovered developer to the first and second recovered developer containers 10L and 10R.

[0039] <Upstream conveying section> 4 and 5, the upstream transfer section 3 has first to fifth discharge pipes 31 to 35 and a main discharge pipe 36. The first to fifth discharge pipes 31 to 35 and the main discharge pipe 36 are disposed inside the apparatus body 110 near the rear end portion.

[0040] In this embodiment, the first to fifth discharge pipes 31 to 35 are hollow tubular members extending vertically approximately along the direction of gravity. The first discharge pipe 31 is formed with a first discharge receiving port 31a which is an opening connected to the belt cleaning container discharge port 192a (FIG. 2) and a second discharge receiving port 31b which is an opening connected to the yellow developing container discharge port 142a (FIG. 2). The second discharge pipe 32 is formed with a first discharge receiving port 32a which is an opening connected to the yellow drum cleaning container discharge port 162a (FIG. 2) and a second discharge receiving port 32b which is an opening connected to the magenta developing container discharge port 142a (FIG. 2). The third discharge pipe 33 is formed with a first discharge receiving port 33a connected to the magenta drum cleaning container discharge port 162a (FIG. 2) and a second discharge receiving port 33b which is an opening connected to the cyan developer container discharge port 142a (FIG. 2). The fourth discharge pipe 34 is formed with a first discharge receiving port 34a connected to the cyan drum cleaning container discharge port 162a (FIG. 2) and a second discharge receiving port 34b which is an opening connected to the black developer container discharge port 142a (FIG. 2). The fifth discharge pipe 34 is formed with a discharge receiving port 35a connected to the black drum cleaning container discharge port 162a (FIG. 2). The lower ends of the first to fifth discharge pipes 31 to 35 are each connected to a main discharge pipe 36, and the insides of the first to fifth discharge pipes 31 to 35 and the inside of the main discharge pipe 36 are connected to each other so as to enable the transfer of recovered developer.

[0041] In this embodiment, the main discharge pipe 36 is a hollow tubular member extending left and right along a substantially horizontal direction. Particularly, in this embodiment, the main discharge pipe 36 is configured as a circular pipe having a substantially circular cross section substantially perpendicular to the extension direction (axial direction) of the main discharge pipe 36. The first to fifth discharge pipes 31 to 35 are connected to the upper side of the main discharge pipe 36, respectively, and the inside of the main discharge pipe 36 and the inside of the first to fifth discharge pipes 31 to 35 are communicated so that the recovered developer can be transferred. A discharge screw 37 is disposed inside (hollow portion) of the main discharge pipe 36 as a discharge transport member. In this embodiment, the discharge screw 37 is configured as a shaftless screw conveyor (spring auger) that can rotate around a rotation axis that extends left and right along the extension direction (substantially horizontal direction) of the main discharge pipe 36. The discharge screw 37 transports the recovered developer inside the main discharge pipe 36 while stirring it. A main discharge port 36a is formed on the lower side of the main discharge pipe 36 located between both ends in the extension direction of the main discharge pipe 36. The main discharge port 36a is an opening for allowing the recovered developer to fall by gravity from the main discharge pipe 36 and be discharged to the downstream transport section 4. In this embodiment, the main discharge port 36a is formed at the following position in the horizontal direction in a cross section substantially perpendicular to the front-rear direction of the image forming apparatus 100. That is, the main discharge port 36a is formed on the lower side of the main discharge pipe 36 so as to be located between first and second horizontal pipe discharge ports 42b and 42c provided on a horizontal pipe 42 of the downstream transport section 4 described later in the horizontal direction.

[0042] The recovered developer sent to the first to fifth discharge pipes 31 to 35 falls by gravity through the insides (hollow parts) of the first to fifth discharge pipes 31 to 35 and moves to the main discharge pipe 36. The recovered developer that has fallen to the main discharge pipe 36 is transported to the main discharge port 36a by the discharge screw 37. In this embodiment, the discharge screw 37 has a spiral shape in which the winding directions are different between a first part 37a on the left side and a second part 37b on the right side with respect to the position corresponding to the main discharge port 36a with respect to the rotation axis direction. In addition, the discharge screw 37 is rotated in a predetermined direction by a rotational driving force transmitted from a driving source (discharge screw driving unit) (not shown) provided in the main body 110 of the apparatus via a drive transmission member (such as a single or multiple gears) 125. As a result, the recovered developer sent from the first and second discharge pipes 31 and 32 to the main discharge pipe 36 is transported in a direction from the left side to the right side by the first part 37a of the discharge screw 37 and sent to the main discharge port 36a. On the other hand, the recovered developer sent from the third to fifth discharge pipes 33 to 35 to the main discharge pipe 36 is transported from the right side to the left side by the second portion 37b of the discharge screw 37 and sent to the main discharge port 36a. The recovered developer transported to the main discharge port 36a falls from the main discharge port 36a by gravity and moves to a vertical pipe 41 of the downstream transport section 4 described later.

[0043] <Downstream conveying section> 4 and 5, the downstream conveying section 4 has a vertical pipe 41, a horizontal pipe 42, and first and second recovery pipes 44L, 44R. The vertical pipe 41 and the horizontal pipe 42 are disposed near the rear end inside the apparatus main body 110. The first and second recovery pipes 44L, 44R are disposed above the first and second recovered developer containers 10L, 10R disposed inside the apparatus main body 110, respectively, and extend from the rear side to the front side.

[0044] The developer recovery device 1 has a vertical pipe 41 as a tubular vertical transport section that guides the recovered developer discharged from the image forming section G from above to below in the direction of gravity. In this embodiment, the vertical pipe 41 is a hollow tubular member that extends vertically approximately along the direction of gravity. The vertical pipe 41 may be inclined with respect to the direction of gravity. In this embodiment, the recovered developer falls and moves inside the vertical pipe 41 due to gravity, but a transport member that transports the recovered developer may be provided inside the vertical pipe 41. The main discharge pipe 36 of the upstream transport section 3 is connected to the upper end of the vertical pipe 41. A vertical pipe receiving port 41a, which is an opening for receiving the recovered developer discharged from the main discharge port 36a into the vertical pipe 41, is formed at the upper end of the vertical pipe 41 at a position corresponding to the main discharge port 36a of the main discharge pipe 36. As a result, the inside of the main discharge pipe 36 and the inside of the vertical pipe 41 are in communication with each other via the main discharge port 36a and the vertical pipe receiving port 41a. A vertical pipe discharge port 41b, which is an opening for allowing the recovered developer to fall by gravity from the vertical pipe 41 and be delivered to the horizontal pipe 42, is formed at the lower end of the vertical pipe 41. In this embodiment, the vertical pipe receiving opening 41a and the vertical pipe discharge port 41b are formed at the following positions in the horizontal direction in a cross section substantially perpendicular to the front-rear direction of the image forming apparatus 100. That is, the vertical pipe receiving opening 41a and the vertical pipe discharge port 41b are formed on the vertical pipe 41 so as to be located between first and second horizontal pipe discharge ports 42b and 42c, which are provided on the horizontal pipe 42, which will be described later, in the horizontal direction.

[0045] The developer recovery device 1 has a horizontal pipe 42 as a tubular horizontal transport part capable of guiding the recovered developer transported through the inside of the vertical pipe 41 toward the first recovered developer container 10L and the second recovered developer container 10R along a direction intersecting the direction of gravity. In this embodiment, the horizontal pipe 42 is a hollow tubular member extending left and right along a substantially horizontal direction. The horizontal pipe 42 may be inclined with respect to the horizontal direction. Particularly, in this embodiment, the horizontal pipe 42 is configured as a circular tube having a substantially circular cross section substantially perpendicular to its extension direction (axial direction). The vertical pipe 41 is connected to the upper side of the horizontal pipe 42 between both ends in the extension direction of the horizontal pipe 42. And, at a position corresponding to the vertical pipe discharge port 41b of the vertical pipe 41, a horizontal pipe receiving port 42a, which is an opening for receiving the recovered developer discharged from the vertical pipe discharge port 41b into the horizontal pipe 42, is formed on the upper side of the horizontal pipe 42. As a result, the interior of the vertical pipe 41 communicates with the interior of the horizontal pipe 42 via the vertical pipe outlet 41b and the horizontal pipe inlet 42a. In addition, first and second horizontal pipe outlets 42b and 42c are formed on the lower side of the horizontal pipe 42 located at both ends in the extension direction of the horizontal pipe 42. The first and second horizontal pipe outlets 42b and 42c are openings for allowing the recovered developer to fall by gravity from the horizontal pipe 42 and be discharged to the first and second recovery pipes 44L and 44R, respectively. The first horizontal pipe outlet 42b is formed near the left end (first end) of the horizontal pipe 42, and the second horizontal pipe outlet 42c is formed near the right end (second end) of the horizontal pipe 42. Here, the horizontal pipe receiving port 42a is formed in the horizontal pipe 42 so as to be located between the first and second horizontal pipe discharge ports 42b, 42c in the horizontal direction in a cross section substantially perpendicular to the front-rear direction of the image forming apparatus 100. In this manner, the horizontal pipe 42 includes the first horizontal pipe discharge port 42b, which is provided on the first end side in the extension direction of the horizontal pipe 42 and discharges the recovered developer from the horizontal pipe 42 toward the first recovered developer container 10L.The horizontal pipe 42 also has a second horizontal pipe discharge port 42c that is provided on a second end side opposite to the first end in the extension direction of the horizontal pipe 42 and discharges the recovered developer from the horizontal pipe 42 toward the second recovered developer container 10R. The horizontal pipe 42 also has a horizontal pipe receiving port 42a that is provided between the first horizontal pipe discharge port 42b and the second horizontal pipe discharge port 42c in the extension direction of the horizontal pipe 42 and receives the recovered developer from the vertical pipe 41 into the horizontal pipe 42.

[0046] A conveying screw 43 is disposed inside (hollow portion) of the horizontal pipe 42 as a conveying member. In this embodiment, the conveying screw 43 is configured as an axisless screw conveyor (spring auger) that can rotate around a rotation axis extending left and right along the extension direction (approximately horizontal direction) of the horizontal pipe 42. In this embodiment, the conveying screw 43 has a spiral shape with a unidirectional winding direction. The conveying screw 43 conveys the recovered developer inside the horizontal pipe 42 while stirring it. The conveying screw 43 is rotated by a rotational driving force transmitted from the driving unit 5. In this embodiment, the driving unit 5 is configured to have a driving motor 51 as a driving source and a driving train (such as a single or multiple gears) 52 that transmits the driving force from the driving motor 51 to the conveying screw 43. In this embodiment, the driving motor 51 is disposed on the right side of the horizontal pipe 42, and the driving train 52 is connected to the right end of the conveying screw 43. The driving motor 51 of the driving unit 5 can rotate in both forward and reverse directions. As a result, the driving unit 5 can rotate the conveying screw 43 in a first direction and a second direction opposite to the first direction. As described above, the conveying screw 43 has a helical shape with a winding direction in one direction, and conveys the recovered developer inside the horizontal pipe 42 from the right end (second end) side to the left end (first end) side by rotating in the first direction. Moreover, the conveying screw 43 conveys the recovered developer inside the horizontal pipe 42 from the left end (first end) side to the right end (second end) side by rotating in the second direction. In this way, the developer recovery device 1 has the conveying screw 43 that conveys the recovered developer inside the horizontal pipe 42. The conveying screw 43 has a helical shape portion with a winding direction that conveys the recovered developer as follows. That is, the conveying screw 43 conveys the recovered developer in a direction from the second end side toward the first end side along the rotation axis by rotating in a first direction about a rotation axis along the extension direction of the horizontal pipe 42. Moreover, the conveying screw 43 conveys the recovered developer in a direction from the first end side toward the second end side along the rotation axis by rotating in a second direction opposite to the first direction about the rotation axis.The developer recovery device 1 also has a drive unit 5 capable of rotating the conveying screw 43 in a first direction and a second direction.

[0047] The developer recovery device 1 has a first recovery pipe 44L as a tubular first recovery conveying part that guides the recovered developer discharged from the first horizontal pipe discharge port 42b toward the first recovered developer container 10L. The first recovery pipe 44L may be inclined with respect to the horizontal direction. In this embodiment, the first recovery pipe 44L is a hollow tubular member that extends back and forth along a substantially horizontal direction. Particularly, in this embodiment, the first recovery pipe 44L is configured as a circular tube having a substantially circular cross section that is substantially perpendicular to its extension direction (axial direction). The horizontal pipe 42 is connected to the upper side of the first recovery pipe 44L located at the rear end in the extension direction of the first recovery pipe 44L. And, a first recovery receiving port 44aL is formed at the upper side of the first recovery pipe 44L at a position corresponding to the first horizontal pipe discharge port 42b of the horizontal pipe 42. The first recovery receiving port 44aL is an opening for receiving the recovered developer discharged from the first horizontal pipe discharge port 42b into the first recovery pipe 44L. As a result, the inside of the horizontal pipe 42 communicates with the inside of the first recovery pipe 44L via the first horizontal pipe discharge port 42b and the first recovery receiving port 44aL. In addition, a first recovery discharge port 44bL is formed on the lower side of the first recovery pipe 44L located at the front end in the extension direction of the first recovery pipe 44L. The first recovery discharge port 44bL is an opening for allowing the recovered developer to fall by gravity from the first recovery pipe 44L and be discharged to the first recovered developer container 10L. In this way, the first recovery pipe 44L is provided with a first recovery receiving port 44aL that is provided at one end side in the extension direction of the first recovery pipe 44L and receives the recovered developer discharged from the first horizontal pipe discharge port 42b into the first recovery pipe 44L. Also, the first recovery pipe 44L is provided with a first recovery discharge port 44bL that is provided at the other end side in the extension direction of the first recovery pipe 44L and discharges the recovered developer from the first recovery pipe 44L toward the first recovered developer container 10L.

[0048] A first recovery screw 45L as a first recovery conveying member is disposed inside (hollow portion) of the first recovery pipe 44L. In this embodiment, the first recovery screw 45L is configured as an axisless screw conveyor (spring auger) that can rotate around a rotation axis extending back and forth along the extension direction (substantially horizontal direction) of the first recovery pipe 44L. In this embodiment, the first recovery screw 45L has a helical shape with a unidirectional winding direction. The first recovery screw 45L conveys the recovered developer inside the first recovery pipe 44L while stirring it. As shown in FIG. 7, the first recovery screw 45L is rotationally driven by a rotational driving force transmitted from the first recovery driving unit 6L. In this embodiment, the first collection drive unit 6L includes a first collection drive motor 61L as a drive source and a first collection drive train (such as a single or multiple gears) 62L that transmits the drive force from the first collection drive motor 61L to the first collection screw 45L. In this embodiment, the first collection drive source 61L is disposed below the rear end of the first collection pipe 44L, and the first collection drive train 62L is connected to the rear end of the first collection screw 45L. The first collection drive motor 61L of the first collection drive unit 6L rotates in a predetermined direction. As a result, the first collection drive unit 6L drives the first collection screw 45L to rotate in a predetermined direction. As described above, the first collection screw 45L has a helical shape with a unidirectional winding direction, and by rotating in the above-mentioned predetermined direction, the collected developer inside the first collection pipe 44L is transported from the rear end side to the front end side. In this way, the developer recovery device 1 has a first recovery screw 45L that transports the recovered developer inside the first recovery pipe 44L. The first recovery screw 45L has a spiral-shaped portion in a winding direction that transports the recovered developer as follows. That is, the first recovery screw 45L rotates in a predetermined direction about a rotation axis along the extension direction of the first recovery pipe 44L, thereby transporting the recovered developer along the rotation axis in a direction from one end side (rear end side) of the first recovery pipe 44L to the other end side (front end side). In this embodiment, the developer recovery device 1 also has a first recovery drive unit 6L that rotates the first recovery screw 45L.

[0049] Furthermore, the developer recovery device 1 has a second recovery pipe 44R as a tubular second recovery conveying part that guides the recovered developer discharged from the second horizontal pipe discharge port 42c toward the second recovered developer container 10R. In this embodiment, the second recovery pipe 44R is a hollow tubular member that extends back and forth along a substantially horizontal direction. The second recovery pipe 44R may be inclined with respect to the horizontal direction. Particularly, in this embodiment, the second recovery pipe 44R is configured as a circular tube whose cross section is substantially circular and substantially perpendicular to its extension direction (axial direction). The horizontal pipe 42 is connected to the upper side of the second recovery pipe 44R located at the rear end in the extension direction of the second recovery pipe 44R. And, a second recovery receiving port 44aR is formed at the upper side of the second recovery pipe 44R at a position corresponding to the second horizontal pipe discharge port 42c of the horizontal pipe 42. The second recovery receiving port 44aR is an opening for receiving the recovered developer discharged from the second horizontal pipe discharge port 42c into the second recovery pipe 44R. As a result, the inside of the horizontal pipe 42 communicates with the inside of the second recovery pipe 44R via the second horizontal pipe discharge port 42c and the second recovery receiving port 44aR. In addition, a second recovery discharge port 44bR is formed on the lower side of the second recovery pipe 44R located at the front end in the extension direction of the second recovery pipe 44R. The second recovery discharge port 44bR is an opening for allowing the recovered developer to fall by gravity from the second recovery pipe 44R and be discharged to the second recovered developer container 10R. In this way, the second recovery pipe 44R is provided with a second recovery inlet 44aR, which is provided at one end side in the extension direction of the second recovery pipe 44R and receives the recovered developer discharged from the second horizontal pipe outlet 42c into the second recovery pipe 44R. The second recovery pipe 44R is also provided with a second recovery outlet 44bR, which is provided at the other end side in the extension direction of the second recovery pipe 44R and discharges the recovered developer from the second recovery pipe 44R toward the second recovered developer container 10R.

[0050] A second recovery screw 45R serving as a second recovery conveying member is disposed inside (hollow portion) of the second recovery pipe 44R. In this embodiment, the second recovery screw 45R is configured as an axisless screw conveyor (spring auger) that can rotate around a rotation axis extending back and forth along the extension direction (substantially horizontal direction) of the second recovery pipe 44R. In this embodiment, the second recovery screw 45R has a helical shape with a unidirectional winding direction. The second recovery screw 45R conveys the recovered developer inside the second recovery pipe 44R while stirring it. As shown in FIG. 6, the second recovery screw 45R is rotationally driven by a rotational driving force transmitted from the second recovery drive unit 6R. In this embodiment, the second collection drive unit 6R includes a second collection drive motor 61R as a drive source and a second collection drive train (such as a single or multiple gears) 62R that transmits the drive force from the second collection drive motor 61R to the second collection screw 45R. In this embodiment, the second collection drive source 61R is disposed below the rear end of the second collection pipe 44R, and the second collection drive train 62R is connected to the rear end of the second collection screw 45R. The second collection drive motor 61R of the second collection drive unit 6R rotates in a predetermined direction. As a result, the second collection drive unit 6R drives and rotates the second collection screw 45R in a predetermined direction. As described above, the second collection screw 45R has a spiral shape with a unidirectional winding direction, and by rotating in the above-mentioned predetermined direction, the collected developer inside the second collection pipe 44R is transported from the rear end side to the front end side. In this way, the developer recovery device 1 has a second recovery screw 45R that transports the recovered developer inside the second recovery pipe 44R. The second recovery screw 45R has a spiral-shaped portion in a winding direction that transports the recovered developer as follows. That is, the second recovery screw 45R rotates in a predetermined direction about a rotation axis along the extension direction of the second recovery pipe 44R, thereby transporting the recovered developer along the rotation axis in a direction from one end side (rear end side) of the second recovery pipe 44R to the other end side (front end side). In this embodiment, the developer recovery device 1 also has a second recovery drive unit 6R that rotationally drives the second recovery screw 45R.

[0051] In addition, the first and second recovery pipes 44L and 44R may not be provided, and the recovered developer may be sent directly from the horizontal pipe 42 to the first and second recovered developer containers 10L and 10R. When the first and second recovery pipes 44L and 44R are provided, they can function as a buffer capable of holding a predetermined amount of recovered developer between the horizontal pipe 42 and the first and second recovered developer containers 10L and 10R. For example, even if both the first and second recovered developer containers 10L and 10R are full, image formation can be continued up to the amount that functions as a buffer if the number of remaining image formation sheets of the job is less than a predetermined value. Then, it becomes possible to prompt the user to replace the first and second recovered developer containers 10L and 10R after the job is completed.

[0052] In this embodiment, the first and second recovered developer containers 10L and 10R have first and second container receiving openings 12L and 12R, respectively, on the upper side portions located at the front end portions when the first and second recovered developer containers 10L and 10R are disposed at predetermined positions inside the main body 110 of the apparatus. The first and second container receiving openings 12L and 12R are openings for receiving the recovered developer discharged from the first and second recovered developer discharge openings 44bL and 44bR into the first and second recovered developer containers 10L and 10R, respectively. When the first and second recovered developer containers 10L and 10R are mounted at predetermined positions inside the main body 110 of the apparatus, the first and second container receiving openings 12L and 12R are disposed at positions corresponding to the first and second recovered developer discharge openings 44bL and 44bR, respectively. This allows the insides of the first and second recovered developer containers 10L and 10R to communicate with the insides of the first and second recovered developer containers 10L and 10R. In this embodiment, the first and second shutter members 46L and 46R are provided at the front ends of the first and second recovery pipes 44L and 44R, respectively, to switch the opening and closing states of the first and second recovery and discharge ports 44bL and 44bR. The first and second shutter members 46L and 46R are provided on the first and second recovery pipes 44L and 44R so as to be slidable in the front-rear direction, respectively, and are biased in the direction from the rear to the front by a shutter pressing spring (not shown) as a biasing means. Then, just before the first and second recovery developer containers 10L and 10R are mounted at predetermined positions inside the main body 110 of the apparatus, engagement portions (not shown) provided on the first and second recovery developer containers 10L and 10R engage with the first and second shutter members 46L and 46R. Then, when the first and second collected developer containers 10L, 10R are further inserted to a predetermined position inside the apparatus main body 110, the first and second shutter members 46L, 46R are moved rearward against the biasing force of the shutter pressing spring and opened. When the first and second collected developer containers 10L, 10R are removed from their predetermined positions inside the apparatus main body 110, the first and second shutter members 46L, 46R are closed by the biasing force of the shutter pressing spring in the reverse operation to the above. Note that the shutter members are not limited to those that open and close in conjunction with the movement of the collected developer containers, and may be those that open and close by, for example, an appropriate actuator.Furthermore, the first and second recovered developer containers 10L and 10R may also be provided with shutter members that open and close the first and second container receiving openings 12L and 12R in conjunction with the above-mentioned mounting and removal operations.

[0053] In this embodiment, as shown in Figs. 6 and 7, the first and second container screws 13L and 13R are provided inside the first and second recovered developer containers 10L and 10R as container transport members for transporting the recovered developer stored in the recovered developer storage units 11L and 11R. In this embodiment, the first and second container screws 13L and 13R are configured to transport the recovered developer from the front side to the rear side when the first and second recovered developer containers 10L and 10R are disposed at predetermined positions inside the device main body 110. In this embodiment, the first and second container screws 13L and 13R have a rotating shaft portion and a screw blade portion formed in a spiral shape around the rotating shaft portion. In addition, a drive receiving portion is provided at the rear end of the rotating shaft portion of the first and second container screws 13L and 13R, respectively. When the first and second recovered developer containers 10L and 10R are mounted at predetermined positions inside the apparatus main body 110, the drive receiving portions are connected to the first and second couplings 63L and 63R provided on the apparatus main body 110 side. In this embodiment, the first and second couplings 63L and 63R are rotated by the rotational drive force transmitted from the first and second recovery drive portions 6L and 6R described above. As a result, in this embodiment, the first and second container screws 13L and 13R rotate in conjunction with the first and second recovery screws 45L and 45R described above, respectively, to transport the recovered developer inside the first and second recovered developer containers 10L and 10R.

[0054] As shown in FIG. 8, the first and second couplings 63L and 63R are provided so as to be exposed from first and second container facing portions 122L and 122R, respectively, which will be described later.

[0055] <Container sensors, etc.> Figure 8 shows first and second container opposing portions 122L, 122R facing the first and second recovered developer containers 10L, 10R at the rear ends of the first and second container mounting portions 119L, 119R (Figure 3(b)) of the device main body 110.

[0056] In this embodiment, the first and second container sensors 7L and 7R are provided on the first and second container facing portions 122L and 122R as container detection means for detecting the presence or absence (attachment / detachment state) of the first and second recovered developer containers 10L and 10R, respectively. In this embodiment, the first and second container sensors 7L and 7R are configured as mechanical switches that output signals to a control unit 150 (FIG. 11) described later depending on whether the container is pressed or released. The control unit 150 can control the drive unit 5 based on the detection results of the first and second container sensors 7L and 7R. The first container sensor 7L is pressed by the first recovered developer container 10L when the first recovered developer container 10L is placed at a predetermined position inside the main body 110 of the apparatus, that is, at a position where the first recovered developer discharge port 44bL and the first container receiving port 12L communicate with each other. This allows the control unit 150 to detect that the first collected developer container 10L has been placed at the predetermined position. In addition, when the first collected developer container 10L is moved (removed) from the predetermined position, the first container sensor 7L is released from the pressure of the first collected developer container 10L. This allows the control unit 150 to detect that the first collected developer container 10L has been moved from the predetermined position. Similarly, the control unit 150 can detect that the second collected developer container 10R has been placed at the predetermined position or that the second collected developer container 10R has been moved from the predetermined position, based on a signal from the second container sensor 7R. Note that the container detection means is not limited to a mechanical switch, and may be, for example, an optical sensor.

[0057] In this embodiment, the first and second full sensors 8L and 8R are provided in the first and second container facing portions 122L and 122R as recovered developer detection means for detecting whether the first and second recovered developer containers 10L and 10R are full with recovered developer. In this embodiment, the first and second full sensors 8L and 8R are optical sensors that output signals to a control unit 150 (FIG. 11) described later depending on whether the detection light is transmitted or not. The control unit 150 can control the drive unit 5 based on the detection results of the first and second full sensors 8L and 8R. In this embodiment, the first and second full sensors 8L and 8R have a light-emitting unit that emits detection light and a light-receiving unit that can receive the detection light emitted from the detection light. When the first and second recovered developer containers 10L and 10R are arranged at predetermined positions inside the main body 110 of the apparatus, a detection window portion (not shown) that is provided in each of these containers and that is capable of transmitting the detection light is arranged between the light projecting portion and the light receiving portion. The inside of this detection window portion is designed to receive the recovered developer when a predetermined amount of recovered developer corresponding to a preset full state is stored inside the first and second recovered developer containers 10L and 10R. Therefore, when the first and second recovered developer containers 10L and 10R are filled with recovered developer, the detection light of the first and second full sensor 8L and 8R is blocked by the recovered developer inside the detection window. This allows the control portion 150 to detect that the first and second recovered developer containers 10L and 10R are filled with recovered developer. The recovered developer detection means is not limited to an optical sensor, and may be composed of, for example, a weight sensor.

[0058] Furthermore, in this embodiment, the first and second container facing portions 122L and 122R are provided with first and second locking members 9L and 9R as a means for preventing the first and second collected developer containers 10L and 10R from accidentally moving in the removal direction. The first and second locking members 9L and 9R engage with the engagement portions provided on the first and second collected developer containers 10L and 10R when the first and second collected developer containers 10L and 10R are mounted at predetermined positions inside the main body 110 of the apparatus. The engagement between the first and second locking members 9L and 9R and the first and second collected developer containers 10L and 10R is intended to prevent the first and second collected developer containers 10L and 10R from accidentally moving mainly due to the biasing force of the shutter pressing spring. Therefore, this engagement can be easily released by the force of the operator moving the first and second collected developer containers 10L and 10R to remove them.

[0059] 4. Control mode 11 is a schematic block diagram showing the control mode of the main parts of the image forming apparatus 100 of this embodiment. In this embodiment, a control unit 150 is provided in the device body 110 of the image forming apparatus 100. The control unit 150 is configured to have a CPU 151 as an arithmetic control means which is a central element for performing arithmetic processing, a memory (storage medium) 152 such as a RAM or ROM as a storage means, an input / output circuit (not shown) for controlling input / output of signals between the control unit 150 and each part, and the like. The RAM, which is a rewritable memory, stores information input to the control unit 150, detected information, arithmetic results, and the like, and the ROM stores a control program, a data table obtained in advance, and the like. The CPU 151 and the memory 152 such as a RAM or ROM are capable of transferring and reading data to and from each other.

[0060] The control unit 150 is connected to each unit of the image forming unit G. The control unit 150 is also connected to the drive unit 5 of the developer recovery device 1, the first and second recovery drive units 6L and 6R, the first and second container sensors 7L and 7R, and the first and second full sensors 8L and 8R. The control unit 150 is also connected to an operation unit (operation panel) 130 provided in the image forming apparatus 100. The operation unit 130 has a display unit such as a liquid crystal panel as a display means for displaying information under the control of the control unit 150, and an input unit such as a key as an input means for inputting information to the control unit 150 by operation by an operator such as a user or a service representative. The operation unit 130 may be configured to have a touch panel having the functions of the display unit and the input unit. The control unit 150 may also be connected to an external device such as an image reading device (not shown) provided in the image forming apparatus 100 or connected to the image forming apparatus 100, or a personal computer connected to the image forming apparatus 100.

[0061] The control unit 150 can centrally control each unit of the image forming unit G based on instructions and image information from the operation unit 130 of the image forming apparatus 100 or an external device to execute an image forming operation. The control unit 150 can centrally control each unit of the developer recovery device 1 to execute an operation of transporting the recovered developer to the first and second recovered developer containers 10L and 10R, an operation of prompting replacement of each container, and the like. The control unit 150 can also be considered to constitute a part of the developer recovery device 1.

[0062] 5. Operation of the developer recovery device Next, the transport operation of the recovered developer to the first and second recovered developer containers 10L and 10R by the developer recovery device 1 of this embodiment will be described. Here, the operation of the developer recovery device 1 when transporting the recovered developer to each of the first and second recovered developer containers 10L and 10R will be described. A specific example of the operation sequence of the developer recovery device 1, including switching the transport destination of the recovered developer, will be described later.

[0063] Table 1 summarizes the operating states of the drive unit 5 and the first and second recovery drive units 6L and 6R in the transport operation of the recovered developer to the first and second recovered developer containers 10L and 10R in this embodiment. This operation is performed by the control unit 150 controlling the drive unit 5 and the first and second recovery drive units 6L and 6R in accordance with a program stored in the memory 152.

[0064] [Table 1]

[0065] <Transportation Operation to First Collected Developer Container 10L> FIG. 9 shows the flow of the recovered developer when the recovered developer is transported to the first recovered developer container 10L on the left side. The developer recovery device 1 transports the recovered developer from the image forming unit G to the downstream transport unit 4 via the upstream transport unit 3 as described above. The recovered developer transported to the downstream transport unit 4 moves into the horizontal pipe 42 through the vertical pipe 41. When transporting the recovered developer to the first recovered developer container 10L, the drive motor 51 of the drive unit 5 rotates forward, and the transport screw 43 in the horizontal pipe 42 rotates in the first direction by the drive force transmitted from the drive unit 5. As a result, the transport screw 43 transports the recovered developer in the horizontal pipe 42 in a direction from the right side to the left side. At this time, in conjunction with the forward rotation of the drive motor 51 of the drive unit 5, the first recovery drive motor 61L of the first recovery drive unit 6L rotates, and the second recovery drive motor 61R of the second recovery drive unit 6R is in a stopped state.

[0066] As a result, the recovered developer transported inside the horizontal pipe 42 by the transport screw 43 and sent to the first recovery pipe 44L is transported inside the first recovery pipe 44L by the first recovery screw 45L and sent to the first recovered developer container 10L. On the other hand, the recovered developer sent from the vertical pipe 41 to the horizontal pipe 42 is not transported in the direction from left to right inside the horizontal pipe 42. In addition, the recovered developer is not transported inside the second recovery pipe 44R.

[0067] Therefore, even if the developer recovery device 1 is removed from the apparatus main body 110 to replace the second recovered developer container 10R while the developer recovery device 1 is transporting the recovered developer to the first recovered developer container 10L during operation of the image forming apparatus 1, it is possible to suppress the recovered developer from leaking or scattering from the periphery of the second recovered developer container 10R into the apparatus main body 110. That is, according to this embodiment, while the recovered developer is being transported to the first recovered developer container 10L, the recovered developer sent from the image forming unit G does not pass through the transport path toward the second recovered developer container 10R. Therefore, even if the second recovered developer container 10R is removed, it is possible to reduce the risk of the recovered developer leaking or scattering from the transport path toward the second recovered developer container 10R.

[0068] In this embodiment, a second shutter member 46R is provided on the second recovery pipe 44R, but due to the effect of reducing the risk of leakage or scattering of the recovered developer as described above, it is possible to omit this shutter member or simplify its configuration.

[0069] <Transportation Operation to Second Collected Developer Container 10R> FIG. 10 shows the flow of the recovered developer when the recovered developer is transported to the second recovered developer container 10R on the right side. The developer recovery device 1 sends the recovered developer from the image forming unit G to the downstream transport unit 4 via the upstream transport unit 3 as described above. The recovered developer sent to the downstream transport unit 4 moves into the horizontal pipe 42 through the vertical pipe 41. When the recovered developer is transported to the second recovered developer container 10R, the drive motor 51 of the drive unit 5 rotates in the reverse direction, and the transport screw 43 in the horizontal pipe 42 rotates in the second direction by the drive force transmitted from the drive unit 5. As a result, the transport screw 43 transports the recovered developer in the horizontal pipe 42 in the direction from the left side to the right side. At this time, in conjunction with the reverse rotation of the drive motor 51 of the drive unit 5, the second recovery drive motor 61R of the second recovery drive unit 6R rotates, and the first recovery drive motor 61L of the first recovery drive unit 6L is stopped.

[0070] As a result, the recovered developer transported inside the horizontal pipe 42 by the transport screw 43 and sent to the second recovery pipe 44R is transported inside the second recovery pipe 44R by the second recovery screw 45R and sent to the second recovered developer container 10R. On the other hand, the recovered developer sent from the vertical pipe 41 to the horizontal pipe 42 is not transported in the direction from right to left inside the horizontal pipe 42. In addition, the recovered developer is not transported inside the first recovery pipe 44L.

[0071] Therefore, even if the developer recovery device 1 is removed from the apparatus main body 110 to replace the first recovered developer container 10L while the developer recovery device 1 is transporting the recovered developer to the second recovered developer container 10R during operation of the image forming apparatus 1, it is possible to suppress the recovered developer from leaking or scattering from the periphery of the first recovered developer container 10L into the apparatus main body 110. That is, according to this embodiment, when the recovered developer is being transported to the second recovered developer container 10R, the recovered developer sent from the image forming unit G does not pass through the transport path toward the first recovered developer container 10L. Therefore, even if the first recovered developer container 10L is removed, it is possible to reduce the risk of the recovered developer leaking or scattering from the transport path toward the first recovered developer container 10L.

[0072] In this embodiment, the first recovery pipe 44L is provided with a first shutter member 46L, but similar to the case of the second shutter member 46R, it is also possible to omit this shutter member or simplify its configuration.

[0073] In this manner, the developer recovery device 1 has a control unit 150 that controls the drive unit 5, the first recovery drive unit 6L, and the second recovery drive unit 6R. When the drive unit 5 drives the conveying screw 43 to rotate in the first direction, the control unit 150 controls the first recovery drive unit 6L to rotate the first recovery screw 45L and stops the second recovery drive unit 6R to rotate the second recovery screw 45R. When the drive unit 5 drives the conveying screw 43 to rotate in the second direction, the control unit 150 controls the first recovery drive unit 6L to stop the first recovery screw 45L and stops the second recovery drive unit 6R to rotate the second recovery screw 45R.

[0074] 6. Operation sequence of developer recovery device Next, a specific example of the operation sequence of the developer recovery device 1 including switching the destination of the recovered developer in the developer recovery device 1 of this embodiment will be described. FIG. 12 is a flow chart showing an outline of the procedure of the operation sequence. For simplicity, the operation of switching the destination of the recovered developer during the execution of a job of continuous image formation will be described on the assumption that the first and second recovered developer containers 10L and 10R are arranged at predetermined positions inside the device main body 110. Note that a job is a series of operations that form and output images on one or more recording materials P, which is started by one start instruction. In addition, although not described below, the control unit 150 also controls the operations of the first and second recovery drive units 6L and 6R as described above in conjunction with the control of the operation of the drive unit 5 (see Table 1). In addition, although not described below, the discharge screw 37 of the upstream transport unit 3 is continuously driven to rotate during the image forming operation, and is stopped when the image forming operation is completed (or interrupted).

[0075] When a job is input and an image forming operation is started (S101), the control unit 150 judges whether the current destination of the collected developer is the first collected developer container 10L or not based on information stored in the memory 152 (S102). Note that, every time the control unit 150 switches the destination of the collected developer, the control unit 150 stores information on the current destination of the collected developer in the memory 152. If the control unit 150 judges in S102 that the current destination of the collected developer is not the first collected developer container 10L ("No"), the control unit 150 proceeds to the process of S112. If the control unit 150 judges in S102 that the current destination of the collected developer is the first collected developer container 10L ("Yes"), the control unit 150 rotates the drive motor 51 of the drive unit 5 in the forward direction (S103). Next, the control unit 150 judges whether the first recovered developer container 10L is full or not (whether the signal of the first full sensor 8L is ON or not) based on the signal from the first full sensor 8L (S104). If the control unit 150 judges that the first recovered developer container 10L is not full ("No") in S104, the control unit 150 continues the image forming operation (S105). Next, the control unit 150 judges whether there is an image that has not been output for the job (S106). Then, if the control unit 150 judges that there is an image that has not been output ("Yes") in S106, the control unit 150 returns to the process of S104, and if the control unit 150 judges that there is no image that has not been output ("No") in S106, the control unit 150 stops the drive motor 51 of the drive unit 5 (S107). In addition, the control unit 150 ends the image forming operation and ends the job (S108). Furthermore, when the control unit 150 determines in S104 that the second collected developer container 10R is full (whether the signal of the second full sensor 8R is ON or not) based on the signal from the second full sensor 8R (S109). When the control unit 150 determines in S109 that the second collected developer container 10R is full (whether the signal of the second full sensor 8R is ON or not), the control unit 150 stops the drive motor 51 of the drive unit 5 (S110). Furthermore, the control unit 150 interrupts the image forming operation (S111). In S111, the control unit 150 can display, on the operation unit 130 (or a display unit of an external device, etc.) to notify that both the first and second collected developer containers 10L and 10R are full.

[0076] On the other hand, when the control unit 150 determines in S109 that the second collected developer container 10R is not full ("No"), it switches the rotation direction of the drive motor 51 of the drive unit 5 to rotate in the reverse direction (S112). As a result, the destination of the collected developer is switched from the first collected developer container 10L to the second collected developer container 10R. Note that even when the control unit 50 determines in S102 that the current destination of the collected developer is not the first collected developer container 10L ("No"), it also rotates the drive motor 51 of the drive unit 5 in the reverse direction (S112). Next, the control unit 150 determines whether the second collected developer container 10L is full (whether the signal of the second full sensor 8R is ON) based on the signal from the second full sensor 8R (S113). When the control unit 150 determines in S113 that the second collected developer container 10R is not full ("No"), it continues the image forming operation (S114). Next, the control unit 150 judges whether there is an image of the job that has not been output (S115). If the control unit 150 judges in S115 that there is an image that has not been output ("Yes"), the process returns to S113, and if the control unit 150 judges in S115 that there is no image that has not been output ("No"), the control unit 150 stops the drive motor 51 of the drive unit 5 (S116). Furthermore, the control unit 150 ends the image forming operation and ends the job (S117). Furthermore, if the control unit 150 judges in S113 that the container is full ("Yes"), the control unit 150 judges whether the first recovered developer container 10L is full (whether the signal of the first full sensor 8L is ON) based on the signal from the first full sensor 8L (S118). If the control unit 150 judges in S118 that the container is not full ("No"), the process proceeds to S103. That is, the control unit 50 switches the rotation direction of the drive motor 51 of the drive unit 5 to rotate in the forward direction, and switches the destination of the recovered developer from the second recovered developer container 10R to the first recovered developer container 10L. If the control unit 150 determines in S118 that the containers are full ("Yes"), it stops the drive motor 51 of the drive unit 5 (S119). The control unit 150 also suspends the image forming operation (S120). In S120, the control unit 150 can display, on the operation unit 130 (or a display unit of an external device, etc.), a message to notify the user that both the first and second recovered developer containers 10L and 10R are full.

[0077] Furthermore, when the rotation direction of the drive motor 51 of the drive unit 5 is switched in S112 and S103 to switch the container to which the recovered developer is transported, the control unit 150 can do the following. That is, the operation unit 130 (or the display unit of the external device, etc.) can display a message (such as a message urging the user to replace the full container) to inform the user that the full container needs to be replaced. At this time, the message may be displayed after the job is completed, rather than immediately during the image forming operation. After the job is completed, the developer recovery device 1 may be operated to transport the recovered developer toward the full container, so that the recovered developer remaining in the recovery pipe 44 corresponding to the full container is transported to that container. This can prevent the recovered developer from being left in the recovery pipe 44 and flocculating (adhering) thereto.

[0078] Although the description is omitted here for simplicity, the control unit 150 can control the image forming operation and the operation of the developer recovery device 1 based on the signals from the first and second container sensors 7L and 7R. For example, when the control unit 150 determines that both the first and second recovered developer containers 10L and 10R are not attached when the start of a job is instructed, the control unit 150 can control not to start the image forming operation. Also, for example, when the control unit 50 detects that one of the first and second recovered developer containers 10L and 10R is full and detects that the other container is not attached, the control unit 50 can control to interrupt the image forming operation. In either case, a display encouraging the attachment of the corresponding container can be displayed on the operation unit 130 (or a display unit of an external device, etc.).

[0079] In this manner, in this embodiment, when one of the first and second recovered developer containers 10L and 10R becomes full, the destination of the recovered developer is switched to the other container, and the first and second recovered developer containers 10L and 10R are used alternately. As a result, even if one of the containers becomes full during an image forming operation, the container can be replaced without stopping the image forming operation. And, according to this embodiment, even when one of the containers is replaced during the image forming operation, it is possible to prevent the recovered developer from leaking or scattering around the container into the device main body 110.

[0080] As described above, according to this embodiment, in a configuration in which recovered developer is selectively recovered into a plurality of recovered developer containers, it is possible to reduce the risk of the recovered developer leaking or scattering.

[0081] [Example 2] Next, another embodiment of the present invention will be described. The basic configurations of the developer recovery device 1 and image forming apparatus 100 of this embodiment are the same as those of embodiment 1. In the developer recovery device 1 and image forming apparatus 100 of this embodiment, elements having the same or corresponding functions or configurations as those of embodiment 1 are given the same reference numerals as those of embodiment 1, and detailed explanations will be omitted.

[0082] 1. Structure of the developer recovery device In the first embodiment, the developer recovery device 1 is configured such that the first and second recovery screws 45L and 45R are each rotationally driven by a drive unit (drive source) separate from the conveying screw 43. In contrast, in the present embodiment, the first and second recovery screws 45L and 45R are configured to be rotationally driven by transmitting the driving force transmitted to the conveying screw 43.

[0083] FIG. 13 is a perspective view of the developer recovery device 1 in this embodiment as seen obliquely from the front (first and second recovered developer containers 10L, 10R connected to the developer recovery device 1 are also shown). FIG. 14 is a cross-sectional view of the developer recovery device 1 of this embodiment shown in FIG. 13 taken along line XX in FIG. 4. FIG. 15 is a cross-sectional view of the developer recovery device 1 of this embodiment shown in FIG. 13 taken along line YY in FIG. 4. FIG. 16 is a perspective view of a part of the developer recovery device 1 of this embodiment as seen obliquely from the rear, showing the drive transmission paths to the first and second recovery screws 45L, 45R.

[0084] 13 and 16, the conveying screw 43 is rotationally driven by a rotational driving force transmitted from the drive unit 5. In this embodiment, the drive unit 5 is configured to have a drive motor 51 as a drive source, and a drive train (such as one or more gears) 52 that transmits the drive force from the drive motor 51 to the conveying screw 43. In this embodiment, the drive source 51 is disposed on the left side of the horizontal pipe 42, and the drive train 52 is connected to the left end of the conveying screw 43.

[0085] As shown in Figs. 13 and 16, the first and second linear shafts 43a and 43b are formed (or connected) at the left and right ends of the conveying screw 43 in the direction of the rotation axis, respectively, and extend outside the horizontal pipe 42. The first and second drive transmission units 20L and 20R are provided so as to be drivably connected to the first and second shafts 43a and 43b, respectively. In this embodiment, the first drive transmission unit 20L is configured to have a first one-way clutch gear 21L as a driving force interrupting member and a first recovery drive train (such as a single or multiple gears) 22L. The first one-way clutch gear 21L is disposed so as to be able to transmit drive to the first shaft 43a of the conveying screw 43, and is configured by pressing a one-way clutch into the inner diameter portion. The first recovery drive train 22L is configured to transmit the rotational drive force from the first one-way clutch gear 21L to the first recovery screw 45L. In this embodiment, the first recovery drive train 22L is also configured to transmit the drive to the first coupling 63L. Similarly, in this embodiment, the second drive transmission section 20L is configured to have a second one-way clutch gear 21R as a drive force interrupting member and a second recovery drive train (such as a single or multiple gears) 22R. The second one-way clutch gear 21R is disposed on the second shaft portion 43b of the conveying screw 43 so as to be capable of transmitting the drive, and is configured by pressing a one-way clutch into the inner diameter portion. In addition, the second recovery drive train 22R is configured to transmit the rotational drive force from the second one-way clutch gear 21R to the second recovery screw 45R. In this embodiment, the second recovery drive train 22R is also configured to transmit the drive to the second coupling 63R.

[0086] The first one-way clutch gear 21L is configured to rotate together with the transport screw 43 when the transport screw 43 rotates in the first direction (the direction in which the collected developer is transported toward the first collected developer container 10L) and transmit the driving force downstream. The second one-way clutch gear 21R is configured to rotate together with the transport screw 43 when the transport screw 43 rotates in the second direction (the direction in which the collected developer is transported toward the second collected developer container 10R) and transmit the driving force downstream.

[0087] 2. Operation of the developer recovery device Next, the transport operation of the recovered developer to the first and second recovered developer containers 10L and 10R by the developer recovery device 1 of this embodiment will be described. Here, the differences from the first embodiment will be mainly described. Table 2 summarizes the operating states of the drive unit 5 and the first and second recovery screws 45L and 45R in the transport operation of the recovered developer to the first and second recovered developer containers 10L and 10R, respectively, in this embodiment. This operation is performed by the control unit 150 controlling the drive unit 5 according to a program stored in the memory 152.

[0088] [Table 2]

[0089] <Transportation Operation to First Collected Developer Container 10L> FIG. 17 shows the flow of the recovered developer when the recovered developer is transported to the first recovered developer container 10L on the left side. In this embodiment, when the recovered developer is transported to the first recovered developer container 10L, the first one-way clutch gear 21L rotates in a direction to transmit the drive force in synchronization with the rotation of the transport screw 43 in the first direction caused by the forward rotation of the drive motor 51 of the drive unit 5. Then, the drive force is transmitted from the first one-way clutch gear 21L to the first recovery drive train 22L, and the first recovery screw 45L rotates. On the other hand, the second one-way clutch gear 21R cuts off the drive force and does not transmit the drive force to the second recovery drive train 22R, so that the second recovery screw 45R remains stopped.

[0090] As a result, the recovered developer transported inside the horizontal pipe 42 by the transport screw 43 and sent to the first recovery pipe 44L is transported inside the first recovery pipe 44L by the first recovery screw 45L and sent to the first recovered developer container 10L. On the other hand, the recovered developer sent from the vertical pipe 41 to the horizontal pipe 42 is not transported in the direction from left to right inside the horizontal pipe 42. In addition, the recovered developer is not transported inside the second recovery pipe 44R.

[0091] Therefore, even if the second recovered developer container 10R is removed from the device main body 110 to be replaced while the developer recovery device 1 is transporting recovered developer to the first recovered developer container 10L during operation of the image forming device 1, it is possible to prevent the recovered developer from leaking or scattering around the second recovered developer container 10R into the device main body 110.

[0092] <Transportation Operation to Second Collected Developer Container 10R> FIG. 18 shows the flow of the recovered developer when the recovered developer is transported to the second recovered developer container 10R on the right side. In this embodiment, when the recovered developer is transported to the second recovered developer container 10R, the second one-way clutch gear 21R rotates in a direction to transmit the drive force in synchronization with the rotation of the transport screw 43 in the second direction caused by the reverse rotation operation of the drive motor 51 of the drive unit 5. Then, the drive force is transmitted from the second one-way clutch gear 21R to the second recovery drive train 22R, and the second recovery screw 45R rotates. On the other hand, the first one-way clutch gear 21L cuts off the drive force and does not transmit the drive force to the first drive train 22L, so that the first recovery screw 45R remains stopped.

[0093] As a result, the recovered developer transported inside the horizontal pipe 42 by the transport screw 43 and sent to the second recovery pipe 44R is transported inside the second recovery pipe 44R by the second recovery screw 45R and sent to the second recovered developer container 10R. On the other hand, the recovered developer sent from the vertical pipe 41 to the horizontal pipe 42 is not transported in the direction from right to left inside the horizontal pipe 42. In addition, the recovered developer is not transported inside the first recovery pipe 44R.

[0094] Therefore, even if the first recovered developer container 10L is removed from the device main body 110 to be replaced while the developer recovery device 1 is transporting recovered developer to the second recovered developer container 10R during operation of the image forming device 1, it is possible to prevent the recovered developer from leaking or scattering around the first recovered developer container 10L into the device main body 110.

[0095] As described above, in this embodiment, the developer recovery device 1 has a first drive transmission unit 20L capable of transmitting the driving force transmitted from the drive unit 5 to the conveying screw 43 to the first recovery screw 45L and capable of blocking the transmission of the driving force. The developer recovery device 1 also has a second drive transmission unit 20R capable of transmitting the driving force transmitted from the drive unit 5 to the conveying screw 43 to the second recovery screw 45R and capable of blocking the transmission of the driving force. When the conveying screw 43 is rotationally driven in the first direction by the drive unit 5, the first drive transmission unit 20L transmits the driving force from the conveying screw 43 to the first recovery screw 45L, and the second drive transmission unit 20R blocks the transmission of the driving force from the conveying screw 43 to the second recovery screw 45R. In addition, when the conveying screw 43 is driven to rotate in the second direction by the drive unit 5, the first drive transmission unit 20L cuts off the transmission of drive force from the conveying screw 43 to the first recovery screw 45L, and the second drive transmission unit 20R transmits the drive force from the conveying screw 43 to the second recovery screw 45R.

[0096] The operation sequence of the developer recovery device 1 in this embodiment can be the same as that described in the embodiment 1 with reference to Fig. 12. However, in this embodiment, it is not necessary to control the operation of the first and second recovery drive units 6L and 6R in conjunction with the control of the operation of the conveying screw 43 by the drive unit 5.

[0097] As described above, according to this embodiment, the same effects as those of the first embodiment can be obtained, and the structure of the developer recovery device 1 can be simplified more than that of the first embodiment.

[0098] [others] Although the present invention has been described above with reference to specific embodiments, the present invention is not limited to the above-mentioned embodiments.

[0099] In the above embodiment, the image forming apparatus is a tandem type color image forming apparatus that employs an intermediate transfer method, but the present invention is not limited to this. For example, the image forming apparatus may be a tandem type color image forming apparatus that employs a direct transfer method. As is well known to those skilled in the art, this image forming apparatus has a recording material carrier (such as a conveying belt formed of an endless belt) that carries and conveys a recording material, instead of the intermediate transfer body in the above embodiment. Then, the toner images formed on the image carriers of the multiple stations are sequentially transferred to the recording material carried and conveyed on the recording material carrier, and after being fixed, are discharged outside the image forming apparatus. In this image forming apparatus, the image forming section includes each station, the recording material carrier, and a fixing device. Also, the image forming apparatus may be a so-called one-drum type color image forming apparatus that transfers multiple color toner images to the intermediate transfer body or the recording material carried on the recording material carrier each time they are sequentially formed on one image carrier. In this image forming apparatus, the image forming section includes a toner image forming section (corresponding to a station) that forms a toner image on one image carrier, an intermediate transfer body (or a recording material carrier), and a fixing device. The image forming apparatus may also be a monochrome image forming apparatus. In this case, the image forming section includes a toner image forming section (corresponding to a station) that forms a toner image on one image carrier, and a fixing device. [Explanation of symbols]

[0100] 1 Developer recovery device 3. Upstream transport section 4 Downstream conveying section 5 Drive unit 6L, 6R First and second recovery drive units 10L, 10R First and second waste developer containers 41 Vertical Pipe 42 Horizontal Pipe 43 Conveying screw 44L, 44R 1st and 2nd recovery pipes 45L, 45R 1st and 2nd recovery screws

Claims

1. A developer recovery device capable of transporting recovered developer discharged from an image forming unit that forms an image using developer to a first recovered developer container and a second recovered developer container, a tubular vertical conveying section that guides the recovered developer discharged from the image forming section from above downward in a direction of gravity; a tubular horizontal transport section capable of guiding the recovered developer transported through the inside of the vertical transport section toward the first recovered developer container and the second recovered developer container along a direction intersecting a gravity direction, the horizontal transport section including: a first discharge outlet provided at a first end in an extension direction of the horizontal transport section and discharging the recovered developer; a second discharge outlet provided at a second end opposite to the first end in the extension direction of the horizontal transport section and discharging the recovered developer; and a receiving port provided between the first discharge outlet and the second discharge outlet in the extension direction of the horizontal transport section and receiving the recovered developer from the vertical transport section into the horizontal transport section; a transport member for transporting the recovered developer inside the horizontal transport section, the transport member including a spiral-shaped portion that rotates in a first direction about a rotation axis along the extension direction of the horizontal transport section to transport the recovered developer in a direction from the second end side toward the first end side, and rotates in a second direction opposite to the first direction about the rotation axis to transport the recovered developer in a direction from the first end side toward the second end side; a drive unit capable of rotating the conveying member in the first direction and the second direction; A developer recovery device comprising:

2. a tubular first recovery and transport section that guides the recovered developer discharged from the first discharge port toward the first recovered developer container, the first recovery and transport section including a first recovery receiving port provided at one end side in an extension direction of the first recovery and transport section and that receives the recovered developer discharged from the first discharge port into the first recovery and transport section, and a first recovery and discharge port provided at the other end side in the extension direction of the first recovery and transport section and that discharges the recovered developer from the first recovery and transport section toward the first recovered developer container; a first recovery and transport member that transports the recovered developer inside the first recovery and transport section, the first recovery and transport member having a spiral-shaped portion that rotates in a predetermined direction about a rotation axis along an extension direction of the first recovery and transport section, thereby transporting the recovered developer in a direction from the one end side to the other end side of the first recovery and transport section; a tubular second recovery and transport section that guides the recovered developer discharged from the second discharge port toward the second recovered developer container, the second recovery and transport section including a second recovery receiving port provided at one end of the second recovery and transport section in an extension direction thereof for receiving the recovered developer discharged from the second discharge port into the second recovery and transport section, and a second recovery and discharge port provided at the other end of the second recovery and transport section in the extension direction thereof for discharging the recovered developer from the second recovery and transport section toward the second recovered developer container; a second recovery and transport member that transports the recovered developer inside the second recovery and transport section, the second recovery and transport member having a spiral-shaped portion that rotates in a predetermined direction about a rotation axis along an extension direction of the second recovery and transport section, thereby transporting the recovered developer in a direction from the one end side to the other end side of the second recovery and transport section; 2. The developer recovery device according to claim 1, further comprising:

3. a first recovery drive unit that rotates the first recovery transport member; a second recovery drive unit that rotationally drives the second recovery transport member; 3. The developer recovery device according to claim 2, further comprising:

4. a control unit that controls the drive unit, the first collection drive unit, and the second collection drive unit; The developer recovery device described in claim 3, characterized in that when the drive unit rotates the transport member in the first direction, the control unit controls the first recovery transport member to be rotationally driven by the first recovery drive unit and stops the rotational drive of the second recovery transport member by the second recovery drive unit, and when the drive unit rotates the transport member in the second direction, the control unit controls the first recovery transport member to be rotationally driven by the first recovery drive unit and stops the rotational drive of the first recovery transport member by the first recovery drive unit and rotates the second recovery transport member by the second recovery drive unit.

5. a first drive transmission unit capable of transmitting a drive force transmitted from the drive unit to the transport member to the first recovery transport member and capable of cutting off the transmission of the drive force; a second drive transmission unit capable of transmitting the drive force transmitted from the drive unit to the transport member to the second recovery transport member and interrupting the transmission of the drive force; 3. The developer recovery device according to claim 2, further comprising:

6. when the transport member is rotationally driven in the first direction by the drive unit, the first drive transmission unit transmits a drive force from the transport member to the first collecting and transporting member, and the second drive transmission unit interrupts transmission of the drive force from the transport member to the second collecting and transporting member; The developer recovery device described in claim 5, characterized in that when the transport member is rotationally driven in the second direction by the drive unit, the first drive transmission unit cuts off the transmission of drive force from the transport member to the first recovery transport member, and the second drive transmission unit transmits drive force from the transport member to the second recovery transport member.

7. An image forming apparatus having an image forming unit that forms an image using a developer, and a first recovered developer container and a second recovered developer container that accommodate recovered developer discharged from the image forming unit are detachable, 7. An image forming apparatus comprising: the developer recovery device according to claim 1, which is capable of transporting recovered developer discharged from the image forming unit to the first recovered developer container and the second recovered developer container.

8. a first sensor for detecting whether the first recovered developer container is full; a second sensor for detecting whether the second recovered developer container is full; a control unit that controls the drive unit based on detection results of the first sensor and the second sensor, 8. The image forming apparatus according to claim 7, wherein the control unit controls the drive unit to switch the rotation direction of the transport member from the first direction to the second direction when the control unit detects that the first recovered developer container is full and detects that the second recovered developer container is not full while transporting the recovered developer to the first recovered developer container.

Images