Image forming apparatus

Abstract

To provide an image forming apparatus capable of suppressing an increase in size of the apparatus and simplifying a conveyance path of recovered developer, in a configuration in which a plurality of recovered developer containers are detachably provided.SOLUTION: Below the image forming portion G and above the recording material accommodating portion 11, a half or more of a length of each of the first and second developer collecting containers 10L and 10R with respect to the depth direction D and a half or more of a length of each of the first and second developer collecting containers 10L and 10R with respect to the widthwise direction W are disposed in a region sandwiched between the image forming portion G and the recording material accommodating portion 11. The first and second developer collecting containers 10L and 10R are constituted so as to be arranged and held in the widthwise direction W.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to an image forming apparatus such as a copying machine, a printer, a facsimile machine, or a multifunction machine having a plurality of functions among these, which uses an electrophotographic system or an electrostatic recording system. [Background technology]

[0002] In conventional image forming apparatuses, such as electrophotographic copying machines, a toner image formed on a photoconductor (image carrier) using a developer containing toner by an electrophotographic image formation process is transferred to a transfer medium such as a recording medium. When the toner image is transferred from the photoconductor to the transfer medium, residual toner (transfer residual toner) remaining on the photoconductor is removed from the photoconductor by a cleaning unit and transported to a recovered developer container by a developer recovery device as recovered developer, where it accumulates. When the recovered developer container becomes full, it is replaced with an empty recovered developer container. Conventionally, replacing a recovered developer container requires stopping the image formation operation of the image forming apparatus in order to stop the developer recovery device from transporting the recovered developer. Therefore, in operations requiring continuous, large-volume printing, for example, replacing the recovered developer container reduces productivity.

[0003] To address this issue, a configuration is known in which a plurality of recovered developer containers are detachably provided in the main body of the image forming apparatus.

[0004] Patent Document 1 proposes a configuration in which waste toner is transported to the lowest toner recovery container among multiple toner recovery containers stacked vertically, and when this toner recovery container becomes full, it is removed, causing the toner recovery container immediately above it to move to the bottom. In the configuration described in Patent Document 1, the toner recovery container is located to the right, left, or rear of the paper cassette at the bottom of the device.

[0005] Furthermore, Patent Document 2 proposes a configuration in which waste developer is transferred to one of a plurality of collection containers, and when this collection container is nearly full, the plurality of collection containers are moved all at once, and another collection container is used as a buffer container for temporarily storing the waste developer. In the configuration of Patent Document 2, the collection container is attached to a container attachment part formed at the bottom on the rear side of the housing of the image forming apparatus. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Laid-Open No. 2008-203751 [Patent Document 2] Japanese Patent Application Laid-Open No. 2014-115521 Summary of the Invention [Problem to be solved by the invention]

[0007] However, in the conventional configuration in which multiple recovered developer containers are detachably provided, the image forming apparatus tends to become large in size, and the transport path for the recovered developer from the image forming unit to each recovered developer container tends to become complicated, increasing the risk of the recovered developer sticking or clogging in the transport path.

[0008] In the above, the recovered developer has been described as being transfer residual toner removed from a photosensitive member, but the recovered developer generated in an image forming apparatus is not limited to this. For example, the recovered developer may be transfer residual toner removed from an intermediate transfer member serving as a second image carrier that is transported for secondary transfer of a toner image primarily transferred from a photosensitive member serving as a first image carrier to a recording material. Furthermore, for example, the recovered developer may be developer (which may include toner and carrier) discharged from a developing device that develops an electrostatic image formed on an image carrier.

[0009] Therefore, an object of the present invention is to provide an image forming device that has a configuration in which multiple recovered developer containers are detachably provided, while preventing the device from becoming larger and simplifying the transport path for the recovered developer. [Means for solving the problem]

[0010] The above object is achieved by an image forming apparatus according to the present invention. In summary, the present invention provides an image forming apparatus having a recording material storage section that stores recording material, an image forming section that forms an image on the recording material sent out from the recording material storage section using a developer, a rotatable transport member that transports the recording material sent out from the recording material storage section toward the image forming section, a developer recovery device that can transport recovered developer discharged from the image forming section to a first recovered developer container and a second recovered developer container, and a container mounting section that can hold the first recovered developer container and the second recovered developer container, and to which the first recovered developer container and the second recovered developer container are detachably mounted, wherein a direction substantially parallel to the rotation axis of the transport member is defined as When the depth direction of the image forming device and the direction approximately parallel to the horizontal direction in a cross section approximately perpendicular to the rotation axis of the conveying member are defined as the width direction of the image forming device, the container mounting section is located below the image forming section and above the recording material storage section, and is capable of holding the first recovered developer container and the second recovered developer container side by side in the width direction so that more than half of the length of each of the first recovered developer container and the second recovered developer container in the depth direction and more than half of the length of each of the first recovered developer container and the second recovered developer container in the width direction are positioned in an area sandwiched between the image forming section and the recording material storage section. [Effects of the Invention]

[0011] According to the present invention, in a configuration in which a plurality of recovered developer containers are detachably provided, it is possible to suppress an increase in the size of the device and to simplify the transport path for the recovered developer. [Brief explanation of the drawings]

[0012] [Figure 1] FIG. 1 is a schematic cross-sectional view of an image forming apparatus. [Figure 2] 5A and 5B are schematic diagrams illustrating a manner in which recovered developer is discharged from an image forming unit. [Figure 3] FIG. 2 is a schematic perspective view of an image forming apparatus showing a manner in which a recovered developer container is attached. [Figure 4] FIG. 2 is a schematic diagram illustrating the inside of the image forming apparatus. [Figure 5] FIG. 2 is a schematic cross-sectional view showing a transport path for a collected developer. [Figure 6] FIG. 4 is a schematic block diagram showing a control mode of the developer recovery device. [Figure 7] FIG. 10 is a flowchart showing an outline of the procedure of a developer collecting operation. [Figure 8] FIG. 10 is a schematic cross-sectional view of an image forming apparatus according to another embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0013] 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. Overall configuration and operation of the image forming apparatus 1 is a schematic cross-sectional view (a cross-section substantially perpendicular to the direction of the rotation axis of a photosensitive drum 1, which will be described later) of an image forming apparatus 100 according to this embodiment. The image forming apparatus 100 according to this embodiment is a tandem printer employing an intermediate transfer method, capable of forming full-color images using an electrophotographic method.

[0015] With respect to the image forming apparatus 100 and its elements, the front side of the page in FIG. 1 is referred to as the "front" side, and the back side of the page in FIG. 1 is referred to as the "rear" side. An operator, such as a user or a service representative, typically operates the image forming apparatus 100 from the front side of the image forming apparatus 100. The front-to-rear direction of the image forming apparatus 100 is assumed to be approximately parallel to the direction of the rotation axis of the photosensitive drum 1, which will be described later. With respect to the image forming apparatus 100 and its elements, the left and right sides when viewed from the front side are referred to as the "left" and "right" sides, respectively. 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 or directly below, and also includes the sides above and below a horizontal plane passing through the element or position of interest.

[0016] Image forming apparatus 100 includes multiple image forming units, namely, first, second, third, and fourth stations SY, SM, SC, and SK, which form images of yellow (Y), magenta (M), cyan (C), and black (K), respectively. Elements in each station SY, SM, SC, and SK that have the same or corresponding functions or configurations will be generally described by omitting the Y, M, C, or K suffix to the reference numeral, indicating that the element is for one of the colors. In this embodiment, station S includes a photosensitive drum 1, a charging device 2, an exposure device 3, a developing device 4, a primary transfer roller 5, and a drum cleaning device 6, which will be described later. In this embodiment, multiple (four in this embodiment) stations SY, SM, SC, and SK are arranged side by side in a direction intersecting the direction of gravity, particularly in a substantially horizontal direction in this embodiment.

[0017] The photosensitive drum 1, a rotatable drum-type photosensitive member (electrophotographic photosensitive member) serving as a first image carrier, is driven to rotate in the direction of arrow R1 in the figure. In this embodiment, four photosensitive drums 1 are arranged side by side in a substantially horizontal direction. The surface of the rotating photosensitive drum 1 is uniformly charged to a predetermined polarity (negative in this embodiment) by a charging device 2 serving as a charging means. The charged surface of the photosensitive drum 1 is scanned and exposed by an exposure device (laser scanner) 3 serving as an exposure means in accordance with image information, forming an electrostatic image (electrostatic latent image) on the photosensitive drum 1. The electrostatic image formed on the photosensitive drum 1 is developed (visualized) by the supply of toner by a developing device 4 serving as a developing means, forming a toner image on the photosensitive drum 1. In this embodiment, toner charged to the same polarity as the charge polarity of the photosensitive drum 1 (positive in this embodiment) adheres to the exposed portion (image portion) of the photosensitive drum 1, where the absolute value of the potential has been reduced by exposure after being uniformly charged. In this embodiment, the normal charging polarity of the toner, which is the charging polarity of the toner during development, is negative.

[0018] An intermediate transfer belt 7, an intermediate transfer body formed of an endless belt and serving as a second image carrier, is disposed facing the four photosensitive drums 1. The intermediate transfer belt 7 is stretched over and tensioned by a predetermined tension between a drive roller 71, a tension roller 72, and a secondary transfer counter roller 73, which serve as multiple support rollers. The drive roller 71 is driven to rotate, transmitting a driving force to the intermediate transfer belt 7, causing it to rotate (circularly move) in the direction of arrow R2 in the figure. Primary transfer rollers 5, roller-type primary transfer members serving as primary transfer means, are disposed on the inner circumferential surface of the intermediate transfer belt 7 and correspond to each photosensitive drum 1. The primary transfer rollers 5 press the intermediate transfer belt 7 toward the photosensitive drums 1, forming a primary transfer nip N1 where the photosensitive drums 1 and the intermediate transfer belt 7 come into contact. The toner image formed on the photosensitive drums 1 as described above is primarily transferred onto the rotating intermediate transfer belt 7 by the action of the primary transfer rollers 5 at the primary transfer nip N1. During primary transfer, a primary transfer voltage, which is a DC voltage of the opposite polarity to the normal charging polarity of the toner, is applied to the primary transfer roller 5. For example, when forming a full-color image, the toner images of yellow, magenta, cyan, and black formed on each photosensitive drum 1 are sequentially primary-transferred onto the intermediate transfer belt 7 so as to be superimposed on top of each other.

[0019] A secondary transfer roller 8, a roller-type secondary transfer member serving as a secondary transfer means, is disposed on the outer peripheral surface of the intermediate transfer belt 7, facing the secondary transfer opposing roller 73. The secondary transfer roller 8 is pressed against the secondary transfer opposing roller 73 via the intermediate transfer belt 7, forming a secondary transfer portion (secondary transfer nip) N2 where the intermediate transfer belt 7 and the secondary transfer roller 8 come into contact. The toner image formed on the intermediate transfer belt 7 as described above is secondarily transferred onto a recording material (recording medium, sheet) P, such as recording paper, being conveyed between the intermediate transfer belt 7 and the secondary transfer roller 8 at the secondary transfer portion N2. During secondary transfer, a secondary transfer voltage, which is a DC voltage with a polarity opposite to the normal charging polarity of the toner, is applied to the secondary transfer roller 8. The recording material P is accommodated in a cassette 11, which serves as a recording material accommodation portion. The recording material P is supplied from the cassette 11 to the secondary transfer portion N2 by a recording material conveyance device 12. The recording material conveying device 12 has a pickup roller 12a, a feed roller 12b, a conveying roller 12c, and a registration roller 12d. The pickup roller 12a feeds the recording material P one sheet at a time from the cassette 11. The feed roller 12b and the conveying roller 12c convey the recording material P fed from the cassette 11. The registration roller 12d temporarily stops the recording material P conveyed by the feed roller 12b and the conveying roller 12c, and sends the recording material P to the secondary transfer unit N2 so as to synchronize with the toner image on the intermediate transfer belt 7.

[0020] The recording material P onto which the toner image has been transferred is transported to a fixing device 13 serving as a fixing means. The fixing device 13 has a fixing roller 13a equipped with a heat source and a pressure roller 13b that is in pressure contact with the fixing roller 13a. The fixing device 13 heats and presses the recording material P carrying the unfixed toner image by sandwiching it between the fixing roller 13a and the pressure roller 13b and transporting it, thereby fixing (melting and adhering) the toner image onto the recording material P. The recording material P with the fixed toner image is discharged (output) by a discharge roller 14 onto a tray 15 provided outside the apparatus main body 110 of the image forming apparatus 100.

[0021] Furthermore, toner that remains on the photosensitive drum 1 without being transferred to the intermediate transfer belt 7 during the primary transfer (primary transfer residual toner) is removed from the photosensitive drum 1 and collected by a drum cleaning device 6 serving as a photosensitive body cleaning means. As shown in FIG. 2, the drum cleaning device 6 has a drum cleaning blade 61 formed of an elastic body as a cleaning member, and a drum cleaning container 62 as a toner collection unit. The drum cleaning device 6 scrapes the primary transfer residual toner from the surface of the rotating photosensitive drum 1 by the drum cleaning blade 61 arranged to abut against the surface of the photosensitive drum 1, and stores it inside the drum cleaning container 62.

[0022] Furthermore, a belt cleaning device 9 serving as an intermediate transfer belt cleaning means is disposed on the outer peripheral surface side of the intermediate transfer belt 7, at a position facing the tension roller 72. Toner that remains on the intermediate transfer belt 7 without being transferred to the recording material P during the secondary transfer (secondary transfer residual toner) is removed from the intermediate transfer belt 7 by the belt cleaning device 9 and collected. The belt cleaning device 9 has a belt cleaning blade 91 formed of an elastic body as a cleaning member, and a belt cleaning container 92 as a toner collection unit. The belt cleaning device 9 scrapes secondary transfer residual toner from the surface of the rotating intermediate transfer belt 7 by the belt cleaning blade 91 disposed so as to abut against the surface of the intermediate transfer belt 7, and stores the secondary transfer residual toner inside the belt cleaning container 92.

[0023] The primary transfer residual toner contained in the drum cleaning container 62 is transported by a transport means (not shown) arranged inside the drum cleaning container 62. Then, this primary transfer residual toner is discharged from a drum cleaning container outlet 62a, which is an opening, and sent to a developer recovery device 30, which will be described later, as a recovered developer. Meanwhile, the secondary transfer residual toner contained in the belt cleaning container 92 is transported by a transport means (not shown) arranged inside the belt cleaning container 92. Then, this secondary transfer residual toner is discharged from a belt cleaning container outlet 92a, which is an opening, and sent to a developer recovery device 30, which will be described later, as a recovered developer.

[0024] In this embodiment, at each station S, the photosensitive drum 1 and the charging device 2, developing device 4, and drum cleaning device 6 acting as process means thereon are integrally configured as a process cartridge 17. The process cartridge 17 is configured so that it can be pulled out to the front of the image forming apparatus 100 and detached from the apparatus main body 110. The process cartridges 17 for each color have substantially the same structure, except that the color of toner contained in the developing device 4 is different.

[0025] In this embodiment, the intermediate transfer belt 7, tension rollers 71 to 73 for the intermediate transfer belt 7, the primary transfer rollers 5, and the belt cleaning device 9 are integrated into a unit to form an intermediate transfer unit 70. The intermediate transfer unit 70 is configured so as to be detachable from the apparatus main 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 16Y, 16M, 16C, and 16K as replenishment developer containers that contain developer (replenishment developer) to be replenished to the developing devices 4Y, 4M, 4C, and 4K. The toner cartridges 16 are configured so that they can be pulled out toward the front of the image forming apparatus 100 and attached to and detached from the apparatus main body 110. The toner cartridges 16 for each color have substantially the same structure except for the color of toner they contain. The toner cartridges 16 have a replenishment developer container 16a that contains the replenishment developer, and a replenishment screw 16b that is a replenishment member that serves as a replenishment means for replenishing the replenishment developer inside the replenishment developer container 16a to the developing devices 4.

[0027] In this embodiment, the developing device 4 uses a two-component developer containing toner (non-magnetic toner particles) and carrier (magnetic carrier particles) as the developer. As shown in FIG. 2, the developing device 4 has a rotatable developing sleeve 41 as a developer carrier and a developing container 42 that contains the developer. The developing device 4 carries the developer containing toner and carrier on the developing sleeve 41, and transports the developer to a developing position where the photosensitive drum 1 and the developing sleeve 41 face each other by the rotation of the developing sleeve 41. The developing device 4 supplies the toner of the developer to the electrostatic image on the photosensitive drum 1 at the developing position, thereby forming a toner image on the photosensitive drum 1. In addition, a stirring and transporting means (not shown) disposed inside the developing container 42 circulates and transports the developer contained in the developing container 42 and the replenishment developer replenished from the toner cartridge 16 while stirring them. In this embodiment, the replenishment developer replenished from the toner cartridge 16 to the developing device 4 contains toner and carrier. Then, the developer (which may include toner and carrier) inside the developing container 42 that has become excessive due to the replenishment of the supply developer is discharged from the opening, the developing container discharge port 42a, as the developer is circulated and transported inside the developing container 42, and is sent to the developer recovery device 30, which will be described later, as recovered developer.

[0028] In this embodiment, each station S, the intermediate transfer unit 70, the secondary transfer roller 8, and the fixing device 13 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 the manner in which recovered developer is discharged from the image forming section G (the drum cleaning device 6 and the developing device 4 of each station S, and the belt cleaning device 9).

[0029] 2. Developer recovery container In this embodiment, two containers, first and second recovered developer containers 10L and 10R, are detachably mounted on the apparatus main body 110 of the image forming apparatus 100 as a plurality of recovered developer containers. The recovered developer sent from the image forming unit G to the developer recovery device 30 (described later) is selectively transported to and accumulated in either one of the first or second recovered developer containers 10L or 10R. In this embodiment, as described above, the recovered developer is discharged from the drum cleaning device 6 and developing device 4 of each station S, and the belt cleaning device 9, in the image forming unit G. Furthermore, when either one of the first or second recovered developer containers 10L or 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] The first and second recovered developer containers 10L and 10R are box-shaped containers each having a predetermined length in the longitudinal direction and a predetermined thickness (height) in the thickness direction, and having a substantially rectangular cross section substantially perpendicular to the longitudinal direction. The longitudinal direction is the direction in which the containers are arranged along the front-to-rear direction of the image forming apparatus 100 inside the apparatus main body 110. The lateral direction is the direction in which the containers are arranged along the left-to-right direction of the image forming apparatus 100 inside the apparatus main body 110. The thickness direction is the direction in which the containers are arranged along the up-to-down direction inside the apparatus main body 110. The first and second recovered developer containers 10L and 10R each have a hollow recovered developer storage portion 10aL or 10aR formed therein for storing recovered developer. In this embodiment, the first and second recovered developer containers 10L and 10R have substantially the same structure, and each container can be installed on either the left or right side inside the apparatus main 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.

[0031] FIG. 3 is a schematic perspective view of the image forming apparatus 100, seen obliquely from the front, illustrating the manner in which the first and second collected developer containers 10L and 10R are attached. FIG. 3(a) shows a state in which a container replacement door 18 (described later) is closed, and FIG. 3(b) shows a state in which the container replacement door 18 is open, allowing the first and second collected developer containers 10L and 10R to be attached and detached. The container replacement door 18, which constitutes 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, is provided on the front side of the image forming apparatus 110. In this embodiment, the container replacement door 18 is configured as a single (common) opening / closing member that allows both the first and second collected developer containers 10L and 10R to be attached and detached. In this embodiment, the container replacement door 18 has a generally rectangular shape that is elongated in the left-right direction when viewed from the front. In this embodiment, the container exchange door 18 is configured to be rotatable about a rotation axis extending in the left-right direction intersecting the up-down direction at the bottom of the door. The container exchange door 18 can be opened and closed by an operator by rotating the upper part about the rotation axis extending in the left-right direction at the bottom in the up-down direction.

[0032] As shown in FIG. 3(a), when the container replacement door 18 is closed, it has the appearance of a single panel whose size in the left-right and up-down directions is equal to that of the front panel 11a of the cassette 11 provided adjacently below it. This prevents the appearance from becoming cluttered due to the provision of two containers, the first and second collected developer containers 10L and 10R. Furthermore, by opening and closing the single container replacement door 18, both the first and second collected developer containers 10L and 10R can be attached and detached. This prevents unnecessary operations that could occur if multiple collected developer containers were each provided with their own container replacement door, such as opening and closing the wrong door.

[0033] As shown in FIG. 3(b), by opening the container replacement door 18, an operator can access both the first and second recovered developer containers 10L and 10R. The apparatus main body 110 is provided with a container mounting portion 20 capable of holding the first and second recovered developer containers 10L and 10R, to which the first and second recovered developer containers 10L and 10R are detachably mounted. In this embodiment, the container mounting portion 20 has first and second container mounting portions 20L and 20R to which the first and second recovered developer containers 10L and 10R are respectively mounted. The first and second container mounting portions 20L and 20R have first and second container support portions 21L and 21R extending in the front-to-rear direction and supporting the lower sides of the first and second recovered developer containers 10L and 10R, respectively. The first and second container mounting portions 20L and 20R have, for example, rail-like structures (not shown) that allow the first and second container support portions 21L and 21R to engage with the first and second collected developer containers 10L and 10R, respectively. This allows the first and second collected developer containers 10L and 10R to be slid from the front to the rear and easily disposed at predetermined positions inside the device main body 110. This also allows the first and second collected developer containers 10L and 10R to be slid from the rear to the front and easily removed from the device main body 110 by being pulled out from the predetermined positions inside the device main body 110.

[0034] As shown in FIG. 3(b), identification marks (identification marking portions) 19L and 19R are provided on the inner surface of the container replacement door 18 so that the operator can see them when the container replacement door 18 is open. The identification marks 19L and 19R 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 19L is a sticker bearing letters such as "CONTAINER 1" (or "LEFT CONTAINER") to identify the first collected developer container 10L. In this embodiment, the right identification mark 19R is a sticker bearing letters such as "CONTAINER 2" (or "RIGHT CONTAINER") to identify the second collected developer container 10R. These identification marks 19L and 19R are intended to allow the operator to easily identify the corresponding container when a display prompting the operator to replace one of the collected developer containers 10L and 10R is displayed on the operation unit 80 (FIG. 6) of the image forming apparatus 100, as described below. In this embodiment, the identification marks 19L and 19R are provided on the inner surface of the container replacement door 18, but the present invention is not limited to this. The identification marks 19L and 19R may be provided, for example, on the front surface of a panel adjacent to each of the first and second container mounting portions 20L and 20R, corresponding to the first and second recovered developer containers 10L and 10R, respectively.

[0035] 3. Location of recovered developer container Next, the arrangement of the first and second recovered developer containers 10L and 10R inside the apparatus main body 110 in this embodiment will be further described with reference to Figures 1 and 4. Figure 4 is a schematic diagram showing the arrangement of each part inside the image forming apparatus 100 as seen from the right side.

[0036] Here, a direction substantially parallel to the rotation axis of, for example, a conveying roller 12c serving as a rotatable conveying member that conveys the recording material P sent out from a cassette 11 serving as a recording material storage unit toward the image forming unit G is defined as the depth direction D of the image forming apparatus 100 (FIG. 4). The rotation axis of the conveying roller 12c is substantially parallel to the rotation axis of the photosensitive drum 1. In other words, the depth direction of the image forming apparatus 100 corresponds to the front-rear direction of the image forming apparatus 100 described above. Furthermore, a direction substantially parallel to the horizontal direction in a cross section substantially perpendicular to the rotation axis of the conveying roller 12c is defined as the width direction W of the image forming apparatus 100 (FIG. 1). In other words, the width direction of the image forming apparatus 100 corresponds to the left-right direction of the image forming apparatus 100 described above.

[0037] At this time, the first and second container mounting portions 20L, 20R are capable of holding the first and second collected developer containers 10L, 10R side by side in the width direction W below the image forming unit G and above the cassette 11 such that at least half of the length of the first and second collected developer containers 10L, 10R in the depth direction D and at least half of the length of the first and second collected developer containers 10L, 10R in the width direction W are disposed in an area sandwiched between the image forming unit G and the cassette 11. In other words, the container mounting portion 20 according to this embodiment does not include a configuration in which the first and second collected developer containers 10L, 10R are disposed only on the front side or rear side inside the apparatus main body 110. However, this is not limited to the case where the entire first and second collected developer containers 10L, 10R fit within the area where the area occupied by the image forming unit G is projected downward in the direction of gravity and the area occupied by the cassette 11 is projected upward in the direction of gravity. In particular, in this embodiment, the first and second container mounting portions 20L, 20R can hold the first and second collected developer containers 10L, 10R aligned in the width direction W so that the entire length of each of the first and second collected developer containers 10L, 10R in the width direction W is located in the area sandwiched between the image forming unit G and the cassette 11. Furthermore, in this embodiment, the first and second container mounting portions 20L, 20R are configured so that the first and second collected developer containers 10L, 10R can be attached to and detached from the first and second container mounting portions 20L, 20R by moving them along the depth direction D, respectively.

[0038] In this embodiment, as described above, the image forming section G includes each station S, the intermediate transfer unit 70, and the fixing device 13. In this embodiment, more specifically, the first and second container mounting portions 20L and 20R can hold the first and second collected developer containers 10L and 10R aligned in the width direction W so that more than half of the length of each of the first and second collected developer containers 10L and 10R in the depth direction D and more than half of the length of each of the first and second collected developer containers 10L and 10R in the width direction W are located in an area sandwiched between the intermediate transfer belt 7 and the cassette 11. In particular, in this embodiment, the first and second container mounting portions 20L and 20R are capable of holding the first and second recovered developer containers 10L and 10R side by side in the width direction W so that the entire length of each of the first and second recovered developer containers 10L and 10R in the width direction W is positioned in the area sandwiched between the intermediate transfer belt 7 and the cassette 11.

[0039] This allows the first and second collected developer containers 10L, 10R to be arranged side by side in the width direction W along the substantially horizontal direction inside the apparatus main body 110, without increasing the size of the image forming apparatus 100 in the depth direction D and width direction W. In this embodiment, the first and second collected developer containers 10L, 10R have substantially the same structure, and are arranged side by side at substantially the same height in the vertical direction inside the apparatus main body 110. Note that "arranging the first and second collected developer containers 10L, 10R side by side in the width direction W" includes arranging the first and second collected developer containers 10L, 10R so that they at least partially overlap each other in the vertical direction.

[0040] 4. Structure of the developer recovery device Next, the transport path of the recovered developer by the developer recovery device 30 in this embodiment will be described with reference to Figures 4 and 5. Figure 5 is a schematic cross-sectional view of the image forming apparatus 100 in this embodiment, showing the transport path of the recovered developer with some elements omitted.

[0041] In this embodiment, the developer recovery device 30 has first to fifth discharge pipes 31a to 31e, a main discharge pipe 32, a vertical pipe 33, and a horizontal pipe 34. In this embodiment, the first to fifth discharge pipes 31a to 31e, the main discharge pipe 32, the vertical pipe 33, and the horizontal pipe 34 are arranged near the rear end of the inside of the device main body 110.

[0042] The first to fifth discharge pipes 31a to 31e serving as discharge and conveyance sections are hollow tubular members that extend vertically substantially in the direction of gravity. The first to fourth discharge pipes 31a to 31d receive recovered developer discharged from the drum cleaning devices 6 and developing devices 4 of the stations SY, SM, SC, and SK, respectively. The fifth discharge pipe 31d receives recovered developer discharged from the belt cleaning device 9.

[0043] The main discharge pipe 32, which serves as a discharge / conveyance unit, is a hollow tubular member extending laterally in a substantially horizontal direction. In particular, in this embodiment, the main discharge pipe 32 is configured as a circular pipe with a substantially circular cross section substantially perpendicular to its extension direction (axial direction). The first to fifth discharge pipes 31a to 31e are connected to the upper side portions of the main discharge pipe 32, respectively, and the interiors of the main discharge pipe 32 and the first to fifth discharge pipes 31a to 31e are connected to each other so that the recovered developer can be transferred. A discharge screw 35, which serves as a discharge / conveyance member, is disposed inside (hollow portion of) the main discharge pipe 32. In this embodiment, the discharge screw 35 is configured as a shaftless screw conveyor (spring auger) that can rotate around a rotation axis extending laterally along the extension direction (substantially horizontal direction) of the main discharge pipe 32. The discharge screw 35 transports the recovered developer inside the main discharge pipe 32 while stirring it. A main discharge port 32a is formed on the lower side of the main discharge pipe 32, which is located between both ends in the extension direction of the main discharge pipe 32. This main discharge port 32a is an opening for allowing the recovered developer to fall by gravity from the main discharge pipe 32 and be discharged, and for transferring it to the vertical pipe 33.

[0044] The recovered developer sent to the first to fifth discharge pipes 31a to 31e falls by gravity through the interiors (hollow portions) of the first to fifth discharge pipes 31a to 31e and moves toward the main discharge pipe 32. The recovered developer that falls into the main discharge pipe 32 and joins therewith is transported to the main discharge port 32a by the discharge screw 35. In this embodiment, the discharge screw 35 has a spiral shape with different winding directions between a first portion on the left side and a second portion on the right side, with respect to the rotational axis direction, with the position corresponding to the main discharge port 32a as the boundary. The discharge screw 35 is rotated in a predetermined direction by a rotational driving force transmitted from a drive source (discharge screw driving unit) (not shown) provided in the apparatus main body 110 via a drive transmission member (such as one or more gears). As a result, the recovered developer sent from the first to fifth discharge pipes 31a to 31e to the main discharge pipe 32 is transported from the left side to the right side by the first portion of the discharge screw 35. The recovered developer is also transported from the right side to the left side by the second portion of the discharge screw 35. In this way, the recovered developer inside the main discharge pipe 32 is sent to be collected at the main discharge port 32a. The recovered developer transported to the main discharge port 32a falls from the main discharge port 32a by gravity and moves to the vertical pipe 33.

[0045] The vertical pipe 33 serving as the vertical conveying unit is a hollow tubular member extending vertically substantially in the direction of gravity. The vertical pipe 33 may be inclined with respect to the direction of gravity. In this embodiment, the recovered developer falls within the vertical pipe 33 due to gravity. However, a conveying member for conveying the recovered developer may be provided within the vertical pipe 33. The main discharge pipe 32 is connected to the upper end of the vertical pipe 33. A vertical pipe receiving port 33a, which is an opening for receiving the recovered developer discharged from the main discharge port 32a into the vertical pipe 33, is formed at the upper end of the vertical pipe 33 at a position corresponding to the main discharge port 32a of the main discharge pipe 32. This allows the interior of the main discharge pipe 32 to communicate with the interior of the vertical pipe 33 via the main discharge port 32a and the vertical pipe receiving port 33a. A vertical pipe discharge port 33b, which is an opening for allowing the recovered developer to fall from the vertical pipe 33 due to gravity and be delivered to the horizontal pipe 34, is formed at the lower end of the vertical pipe 33.

[0046] The horizontal pipe 34 serving as the horizontal conveying section is a hollow tubular member extending laterally in a substantially horizontal direction. The horizontal pipe 34 may be inclined with respect to the horizontal direction. In particular, in this embodiment, the horizontal pipe 34 is configured as a circular pipe having a substantially circular cross section substantially perpendicular to its extension direction (axial direction). The vertical pipe 33 is connected to the upper side of the horizontal pipe 34 between both ends of the horizontal pipe 34 in the extension direction. The upper side of the horizontal pipe 34 is formed with a horizontal pipe receiving port 34a, which is an opening for receiving the recovered developer discharged from the vertical pipe discharge port 33b into the horizontal pipe 34, at a position corresponding to the vertical pipe discharge port 33b of the vertical pipe 33. This allows the interior of the vertical pipe 33 to communicate with the interior of the horizontal pipe 34 via the vertical pipe discharge port 33b and the horizontal pipe receiving port 34a. First and second recovery / discharge sections 34b and 34c are provided on the lower side of the horizontal pipe 34, respectively, located at both ends of the horizontal pipe 34 in the extension direction. The first and second collecting and discharging portions 34b, 34c are provided to allow the recovered developer to fall by gravity from the horizontal pipe 34 and be delivered to the first and second recovered developer containers 10L, 10R. An opening (recovery and discharging port) is formed at the end of each of the first and second collecting and discharging portions 34b, 34c facing the first and second recovered developer containers 10L, 10R. The first collecting and discharging portion 34b is provided near the left end (first end) of the horizontal pipe 34, and the second collecting and discharging portion 34c is provided near the right end (second end) of the horizontal pipe 34. The horizontal pipe receiving port 34a is formed in the horizontal pipe 34 so as to be located between the first and second collecting and discharging portions 34b, 34c in the horizontal direction in a cross section substantially perpendicular to the front-rear direction of the image forming apparatus 100.

[0047] A conveying screw 36 serving as a conveying member is disposed inside (in the hollow portion of) the horizontal pipe 34. In this embodiment, the conveying screw 36 is configured as a shaftless screw conveyor (spring auger) that can rotate about a rotation axis extending laterally along the extension direction (substantially horizontal direction) of the horizontal pipe 34. In this embodiment, the conveying screw 36 has a spiral shape that winds in one direction. The conveying screw 36 conveys the recovered developer inside the horizontal pipe 34 while stirring it. The conveying screw 36 is rotationally driven by a rotational driving force transmitted from a driving unit 37. In this embodiment, the driving unit 37 is configured to include a driving motor as a driving source and a drive train (such as one or more gears) that transmits the driving force from the driving motor to the conveying screw 36. The driving motor of the driving unit 37 is rotatable in both forward and reverse directions. This allows the driving unit 37 to rotate the conveying screw 36 in a first direction and a second direction opposite to the first direction. As described above, the conveying screw 36 has a spiral shape with a unidirectional winding direction, and by rotating in a first direction, conveys the recovered developer inside the horizontal pipe 34 from the right end (second end) side toward the left end (first end) side. Also, by rotating in a second direction, the conveying screw 36 conveys the recovered developer inside the horizontal pipe 34 from the left end (first end) side toward the right end (second end) side.

[0048] In this embodiment, the first and second recovered developer containers 10L and 10R have container receiving openings 10bL and 10bR, respectively, on their upper side portions located at the rear end when the first and second recovered developer containers 10L and 10R are disposed at predetermined positions inside the apparatus main body 110. These container receiving openings 10bL and 10bR are for receiving recovered developer discharged from the first and second recovered developer discharge portions 34b and 34c into the first and second recovered developer containers 10L and 10R. When the first and second recovered developer containers 10L and 10R are attached to predetermined positions inside the apparatus main body 110, the container receiving openings 10bL and 10bR are positioned corresponding to the first and second recovered developer discharge portions 34b and 34c, respectively. This establishes communication between the interior of the horizontal pipe 34 and the interior of the first and second recovered developer containers 10L and 10R.

[0049] In this embodiment, the apparatus main body 110 of the image forming apparatus 100 is provided with first and second container sensors 38L and 38R as container detection means for detecting the presence (attachment / detachment) of the first and second recovered developer containers 10L and 10R, respectively. In this embodiment, the first and second container sensors 38L and 38R are configured as mechanical switches that output signals to a control unit 50 (described later) (FIG. 6) that change depending on whether they are pressed or released. The control unit 50 can control the drive unit 37 based on the detection results of the first and second container sensors 38L and 38R. The first container sensor 38L is pressed by the first recovered developer container 10L when the first recovered developer container 10L is positioned in a predetermined position within the apparatus main body 110, i.e., a position where the first recovery / discharge portion 34c and the first container receiving opening 10bL communicate with each other. This allows the control unit 50 to detect that the first collected developer container 10L has been placed at the predetermined position. Furthermore, when the first collected developer container 10L is moved (removed) from the predetermined position, the pressure applied by the first container sensor 38L from the first collected developer container 10L is released. This allows the control unit 50 to detect that the first collected developer container 10L has been moved from the predetermined position. Similarly, the control unit 50 can detect, based on a signal from the second container sensor 38R, 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. The container detection means is not limited to a mechanical switch, and may be, for example, an optical sensor.

[0050] In this embodiment, the apparatus main body 110 of the image forming apparatus 100 is provided with first and second full sensors 39L and 39R 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 39L and 39R are optical sensors that output signals to a control unit 50 (described later) (FIG. 6) that change depending on whether the detection light is transmitted or not. The control unit 50 can control the drive unit 37 based on the detection results of the first and second full sensors 39L and 39R. In this embodiment, the first and second full sensors 39L and 39R each have a light-emitting unit that emits detection light and a light-receiving unit that receives the detection light emitted from the detection sensors. When the first and second recovered developer containers 10L and 10R are placed in predetermined positions within the apparatus main body 110, a detection window (not shown) that allows the detection light to pass through is located between the light-emitting unit and the light-receiving unit. The detection window is designed to receive recovered developer when a predetermined amount of recovered developer corresponding to a preset full state is stored in the first and second recovered developer containers 10L and 10R. Therefore, when the first and second recovered developer containers 10L and 10R are full of recovered developer, the detection light from the first and second fullness sensors 39L and 39R is blocked by the recovered developer inside the detection window. This allows the control unit 50 to detect that the first and second recovered developer containers 10L and 10R are full of recovered developer. The recovered developer detection means is not limited to an optical sensor and may be, for example, a weight sensor.

[0051] 5. Operation of the developer recovery device Next, the operation of transporting recovered developer to the first and second recovered developer containers 10L and 10R by the developer recovery device 30 of this embodiment will be described. Here, the operation of the developer recovery device 30 when transporting recovered developer to each of the first and second recovered developer containers 10L and 10R will be described. This operation is performed by a control unit 50 (FIG. 6) described later controlling the drive unit 37 in accordance with a program stored in a memory 52 (FIG. 6) described later. Specific examples of the operation sequence of the developer recovery device 30, including switching the destination of the recovered developer, will be described later.

[0052] <Transportation Operation to First Collected Developer Container 10L> In the developer recovery device 30, the recovered developer sent from the image forming unit G to the vertical pipe 33 via the first to fifth discharge pipes 31a to 31e and the main discharge pipe 32 as described above moves through the vertical pipe 33 into the horizontal pipe 34. When the recovered developer is to be transported to the first recovered developer container 10L, the drive motor of the drive unit 37 rotates forward, and the conveying screw 36 in the horizontal pipe 34 receives driving force from the drive unit 37 and rotates in a first direction. As a result, the conveying screw 36 conveys the recovered developer in the horizontal pipe 34 from right to left. As a result, the recovered developer conveyed through the horizontal pipe 34 by the conveying screw 34 to the first recovery discharge unit 34b is sent to the first recovered developer container 10L. On the other hand, the recovered developer sent from the vertical pipe 33 to the horizontal pipe 34 is not conveyed from left to right within the horizontal pipe 33.

[0053] <Transportation Operation to Second Collected Developer Container 10R> In the developer recovery device 30, the recovered developer sent from the image forming unit G to the vertical pipe 33 via the first to fifth discharge pipes 31a to 31e and the main discharge pipe 32 as described above moves through the vertical pipe 33 into the horizontal pipe 34. When the recovered developer is to be transported to the second recovered developer container 10R, the drive motor of the drive unit 37 rotates in the reverse direction, and the drive force is transmitted from the drive unit 37 to the conveying screw 36 in the horizontal pipe 34, causing it to rotate in the second direction. As a result, the conveying screw 36 conveys the recovered developer in the horizontal pipe 34 from left to right. As a result, the recovered developer conveyed through the horizontal pipe 34 by the conveying screw 34 to the second recovery discharge unit 34c is sent to the second recovered developer container 10R. On the other hand, the recovered developer sent from the vertical pipe 33 to the horizontal pipe 34 is not conveyed from right to left within the horizontal pipe 33.

[0054] 6. Control mode 6 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 50 is provided in the apparatus body 110 of the image forming apparatus 100. The control unit 50 is configured to include a CPU 51 as an arithmetic control means which is a central element for performing arithmetic processing, a memory (storage medium) 52 such as RAM or ROM as a storage means, and an input / output circuit (not shown) which controls the input and output of signals between the control unit 50 and each part. The RAM, which is a rewritable memory, stores information input to the control unit 50, detected information, arithmetic results, etc., while the ROM stores control programs, pre-calculated data tables, etc. The CPU 51 and memory 52 such as RAM or ROM can transfer and read data to and from each other.

[0055] The control unit 50 is connected to each component of the image forming unit G. The control unit 50 is also connected to the drive unit 37 of the developer recovery device 30, the first and second container sensors 38L and 38R, and the first and second full-state sensors 39L and 39R. The control unit 50 is also connected to an operation unit (operation panel) 80 provided in the image forming apparatus 100. The operation unit 80 includes a display unit such as a liquid crystal panel as a display means for displaying information under the control of the control unit 50, and an input unit such as keys as an input means for inputting information to the control unit 50 through operation by an operator such as a user or a service representative. The operation unit 80 may be configured with a touch panel that functions as both a display unit and an input unit. The control unit 50 may also be connected to an external device, such as an image reading device (not shown) provided in or connected to the image forming apparatus 100, or a personal computer connected to the image forming apparatus 100.

[0056] The control unit 50 can comprehensively control each unit of the image forming unit G based on instructions and image information from the operation unit 80 of the image forming apparatus 100 or an external device, and can cause the image forming operation to be performed. The control unit 50 can also comprehensively control each unit of the developer recovery device 30, and can cause the unit to perform operations such as transporting recovered developer to the first and second recovered developer containers 10L and 10R, and prompting replacement of each container. The control unit 50 can also be considered to constitute a part of the developer recovery device 30.

[0057] 7. Operation sequence of developer recovery device Next, a specific example of an operation sequence of the developer recovery device 30, including switching the destination of the recovered developer in the developer recovery device 30 of this embodiment, will be described. FIG. 7 is a flowchart outlining the steps of the operation sequence. For simplicity's sake, the operation of switching the destination of the recovered developer during execution of a continuous image formation job will be described, assuming that the first and second recovered developer containers 10L and 10R are arranged in predetermined positions inside the device main body 110. Note that a job is a series of operations that start in response to a single start instruction and form and output images on one or more recording materials P. Although not described below, the discharge screw 35 is continuously driven to rotate during the image formation operation and is stopped when the image formation operation is completed (or interrupted).

[0058] When a job is input and an image forming operation is started (S101), the control unit 50 determines whether the current destination of the collected developer is the first collected developer container 10L based on information stored in the memory 52 (S102). Note that, every time the control unit 50 switches the destination of the collected developer, it stores information about the current destination of the collected developer in the memory 52. ​​If 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 proceeds to the process of S112. If the control unit 50 determines in S102 that the current destination of the collected developer is the first collected developer container 10L ("Yes"), it causes the drive motor of the drive unit 37 to rotate forward (S103). Next, the control unit 50 determines whether the first recovered developer container 10L is full (whether the signal from the first full sensor 39L is ON) based on the signal from the first full sensor 39L (S104). If the control unit 50 determines that the first recovered developer container 10L is not full ("No") in S104, it continues the image forming operation (S105). Next, the control unit 50 determines whether there are any unprinted images for the job (S106). If it determines that there are unprinted images ("Yes"), it returns to the processing of S104, and if it determines that there are no unprinted images ("No"), it stops the drive motor of the drive unit 37 (S107). In addition, the control unit 50 ends the image forming operation and ends the job (S108). Furthermore, if the control unit 50 determines in S104 that the second collected developer container 10R is full ("Yes"), it determines whether the second collected developer container 10R is full (whether the signal from the second full sensor 39R is ON) based on the signal from the second full sensor 39R (S109). If the control unit 50 determines in S109 that the second collected developer container 10R is full ("Yes"), it stops the drive motor of the drive unit 37 (S110). Furthermore, the control unit 50 suspends the image forming operation (S111). In S111, the control unit 50 can display, on the operation unit 80 (or a display unit of an external device, etc.), a message to notify the user that both the first and second collected developer containers 10L, 10R are full.

[0059] On the other hand, if the control unit 50 determines in S109 that the second collected developer container 10R is not full ("No"), it switches the rotation direction of the drive motor of the drive unit 37 to rotate it 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 if 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 of the drive unit 37 in the reverse direction (S112). Next, the control unit 50 determines whether the second collected developer container 10L is full (whether the signal from the second full sensor 39R is ON) based on the signal from the second full sensor 39R (S113). If the control unit 50 determines in S113 that the second collected developer container 10L is not full ("No"), it continues the image forming operation (S114). Next, the control unit 50 determines whether there are any unoutput images of the job (S115), and if it determines that there are unoutput images ("Yes"), it returns to the processing of S113, and if it determines that there are no unoutput images ("No"), it stops the drive motor of the drive unit 39 (S116). Furthermore, the control unit 50 ends the image forming operation and ends the job (S117). Furthermore, if it determines that the first recovered developer container 10L is full ("Yes") in S113, it determines whether the first recovered developer container 10L is full (whether the signal from the first full sensor 39L is ON) based on the signal from the first full sensor 39L (S118). If it determines that the first recovered developer container 10L is not full ("No") in S118, it proceeds to the processing of S103. That is, the control unit 50 switches the rotation direction of the drive motor of the drive unit 37 to rotate it forward, and switches the destination of the collected developer from the second collected developer collection container 10R to the first collected developer container 10L. If the control unit 50 determines in S118 that the containers are full ("Yes"), it stops the drive motor of the drive unit 37 (S119). It also suspends the image forming operation (S120). In S120, the control unit 50 can display, on the operation unit 80 (or a display unit of an external device, etc.), a message to notify the user that both the first and second collected developer containers 10L, 10R are full.

[0060] Furthermore, when the rotation direction of the drive motor of the drive unit 37 is switched in S112 and S103 to switch the container to which the recovered developer is to be transported, the control unit 50 can do the following: That is, the operation unit 80 (or the display unit of the external device, etc.) can display a message (such as a message urging the user to replace the container) to notify 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.

[0061] Although not described here for simplicity, the control unit 50 can control the image forming operation and the operation of the developer recovery device 30 based on signals from the first and second container sensors 38L and 38R. For example, when the control unit 50 determines that both the first and second recovered developer containers 10L and 10R are not installed when an instruction to start a job is received, the control unit 50 can control the image forming operation not to start. Furthermore, for example, when the control unit 50 detects that one of the first and second recovered developer containers 10L and 10R is full and then detects that the other container is not installed, the control unit 50 can control the image forming operation to be interrupted. In either case, a display urging the user to install the corresponding container can be displayed on the operation unit 80 (or a display unit of an external device, etc.).

[0062] 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. This allows one container to be replaced without stopping the image formation operation, even if it becomes full during the image formation operation. In this embodiment, the control unit 50 determines to which of the first and second recovered developer containers 10L and 10R the recovered developer is to be transported, based on the detection results of the first and second container sensors 38L and 38R and the first and second fullness sensors 39L and 39R. When the control unit 50 determines to switch the destination container of the recovered developer, for example, because the destination container of the recovered developer becomes full, it reverses the rotation direction of the drive motor of the drive unit 37 to switch the destination container of the recovered developer.

[0063] As mentioned above, conventionally, a configuration in which multiple detachable recovered developer containers are provided tends to increase the size of the image forming apparatus, and the transport path for the recovered developer from the image forming unit to each recovered developer container tends to become complicated, increasing the risk of the recovered developer sticking or clogging the transport path.

[0064] In contrast, in the image forming apparatus 100 of this embodiment, the first and second recovered developer containers 10L and 10R are arranged in parallel in the positions described above, which prevents the image forming apparatus from becoming larger. Furthermore, the transport path for the recovered developer can be shortened, preventing the recovered developer from adhering to or clogging the transport path. In other words, according to this embodiment, in a configuration in which multiple recovered developer containers are detachably provided, it is possible to prevent the apparatus from becoming larger and simplify the transport path for the recovered developer.

[0065] [Example 2] Next, another embodiment of the present invention will be described. In the image forming apparatus of this embodiment, elements having the same or corresponding functions or configurations as those of the image forming apparatus of the first embodiment will be assigned the same reference numerals as those of the image forming apparatus of the first embodiment, and detailed explanations will be omitted.

[0066] 8 is a schematic cross-sectional view (a cross-section substantially perpendicular to the rotation axis direction of the photosensitive drum 1) of the image forming apparatus 100 of this embodiment. The image forming apparatus 100 of this embodiment is a tandem printer employing an intermediate transfer method, capable of forming a full-color image using an electrophotographic method, similar to the image forming apparatus 100 of the first embodiment.

[0067] With respect to the image forming apparatus 100 and its elements, the front side of the page in FIG. 8 is referred to as the "front" side, and the back side of the page in FIG. 8 is referred to as the "rear" side. An operator, such as a user or a service representative, typically operates the image forming apparatus 100 from the front side of the image forming apparatus 100. The front-to-rear direction of the image forming apparatus 100 is assumed to be approximately parallel to the direction of the rotation axis of the photosensitive drum 1. With respect to the image forming apparatus 100 and its elements, the left and right sides when viewed from the front side are referred to as the "left" and "right" sides, respectively. 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 or directly below, but also includes the sides above and below a horizontal plane passing through the element or position of interest.

[0068] In the first embodiment, the image forming apparatus 100 had a plurality of stations SY, SM, SC, and SK (four in the first embodiment) arranged side by side in a direction intersecting the direction of gravity, particularly in the substantially horizontal direction in the first embodiment. In contrast, in the present embodiment, the image forming apparatus 100 has a plurality of stations SY, SM, SC, and SK (four in the present embodiment) arranged side by side in a direction intersecting the horizontal direction, particularly in the substantially gravity direction in the present embodiment. In the image forming apparatus 100 of the present embodiment, as in the image forming apparatus 100 of the first embodiment, the image forming section G includes each station S, an intermediate transfer unit 70, and a fixing device 13.

[0069] Also in this embodiment, as in the first embodiment, two containers, first and second recovered developer containers 10L and 10R, are detachably mounted on the apparatus main body 110 of the image forming apparatus 100 as a plurality of recovered developer containers. The recovered developer sent from the image forming unit G to the developer recovery device 30 is selectively transported to and accumulated in either one of the first or second recovered developer containers 10L or 10R. Also in this embodiment, the recovered developer is discharged, for example, from the drum cleaning device 6 and developing device 4 of each station S, and the belt cleaning device 9 in the image forming unit G. Furthermore, when either one of the first or second recovered developer containers 10L or 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. The first and second recovered developer containers 10L and 10R are detachably mounted in first and second container mounting portions 20L and 20R, which serve as the container mounting portion 20, respectively.

[0070] Here, a direction substantially parallel to the rotation axis of, for example, a conveying roller 12c serving as a rotatable conveying member that conveys the recording material P sent out from a cassette 11 serving as a recording material storage unit toward the image forming unit G is defined as a depth direction D of the image forming apparatus 100 (see FIG. 3). The rotation axis of the conveying roller 12c is substantially parallel to the rotation axis of the photosensitive drum 1. In other words, the depth direction of the image forming apparatus 100 corresponds to the front-rear direction of the image forming apparatus 100 described above. Furthermore, a direction substantially parallel to the horizontal direction in a cross section substantially perpendicular to the rotation axis of the conveying roller 12c is defined as a width direction W of the image forming apparatus 100 (see FIG. 3). In other words, the width direction of the image forming apparatus 100 corresponds to the left-right direction of the image forming apparatus 100 described above.

[0071] At this time, also in this embodiment, similarly to Embodiment 1, the first and second container mounting portions 20L and 20R can hold the first and second collected developer containers 10L and 10R side by side in the width direction W below the image forming unit G and above the cassette 11 such that more than half of the length of the first and second collected developer containers 10L and 10R in the depth direction D and more than half of the length of the first and second collected developer containers 10L and 10R in the width direction W are disposed in an area sandwiched between the image forming unit G and the cassette 11. In particular, in this embodiment, the first and second container mounting portions 20L and 20R can hold the first and second collected developer containers 10L and 10R side by side in the width direction W such that the entire length of the first and second collected developer containers 10L and 10R in the width direction W is disposed in an area sandwiched between the image forming unit G and the cassette 11. In this embodiment, the first and second container mounting portions 20L, 20R are configured so that the first and second collected developer containers 10L, 10R can be attached to and detached from the first and second container mounting portions 20L, 20R by moving them respectively along the depth direction D. In this embodiment, similar to the first embodiment, the first and second collected developer containers 10L, 10R are attached by moving them respectively from the front side to the rear side of the image forming apparatus 100, and are removed by moving them respectively from the rear side to the front side.

[0072] As a result, in this embodiment as well, similarly to the first embodiment, the first and second collected developer containers 10L and 10R can be arranged side by side in the width direction W along the substantially horizontal direction inside the device main body 110, without increasing the size of the image forming apparatus 100 in the depth direction D and the width direction W. In this embodiment, the first and second collected developer containers 10L and 10R have substantially the same structure, and are arranged side by side at substantially the same height in the up-down direction inside the device main body 110.

[0073] Also in this embodiment, the recovered developer discharged from the image forming unit G can be transported to the first and second recovered developer containers 10L and 10R by the developer recovery device 30 similar to that in Embodiment 1. As described above, the recovered developer may be discharged from the drum cleaning device 6 and the developing device 4 of each station S, and the belt cleaning device 9 in the image forming unit G.

[0074] As described above, in the image forming apparatus 100 of this embodiment, in a configuration in which a plurality of stations S are arranged along a direction intersecting the horizontal direction (particularly in this embodiment, approximately the direction of gravity), the first and second recovered developer containers 10L and 10R are arranged in parallel at the positions described above. Even with such a configuration, the same effects as in the first embodiment can be obtained.

[0075] [others] Although the present invention has been described above with reference to specific embodiments, the present invention is not limited to the above-described embodiments.

[0076] In the above-described embodiment, the image forming apparatus is provided with two detachable recovered developer containers as the multiple recovered developer containers. However, three or more (e.g., three or four) detachable recovered developer containers may also be provided. In this case, the same effects as those of the above-described embodiment can be achieved by arranging these three or more recovered developer containers in parallel in the same positions as those described in the above-described embodiment. Furthermore, in the above-described embodiment, the destination of the recovered developer is switched each time one of the multiple recovered developer containers becomes full. However, the use of the multiple recovered developer containers is not limited to this. For example, one of the multiple recovered developer containers may be used as a buffer container. That is, for example, when a first recovered developer container becomes full, the destination of the recovered developer may be temporarily switched to a second recovered developer container, and when the first recovered developer container is replaced with an empty container, the destination of the recovered developer may be returned to the first recovered developer container.

[0077] In the above-described embodiment, the image forming apparatus is a tandem-type color image forming apparatus employing an intermediate transfer system. However, the present invention is not limited to this. For example, the image forming apparatus may be a tandem-type color image forming apparatus employing a direct transfer system. As is well known to those skilled in the art, this image forming apparatus includes a recording material carrier (e.g., an endless conveying belt) that supports and transports a recording material, instead of the intermediate transfer member in the above-described embodiment. Then, toner images formed on the image carriers of multiple stations are sequentially transferred to the recording material carried and transported on the recording material carrier, fixed, and then discharged outside the image forming apparatus. In this image forming apparatus, the image forming unit includes each station, the recording material carrier, and a fixing device. The image forming apparatus may also be a so-called one-drum color image forming apparatus in which multiple color toner images are sequentially formed on one image carrier and transferred to the intermediate transfer member or the recording material carried on the recording material carrier. In this image forming apparatus, the image forming unit includes a toner image forming unit (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 unit includes a toner image forming unit (corresponding to a station) that forms a toner image on one image carrier, and a fixing device. [Explanation of symbols]

[0078] 1 Photosensitive drum 4. Developing device 6 Drum cleaning device 7 Intermediate transfer belt 9 Belt cleaning device 10L, 10R First and second recovered developer containers 20L, 20R 1st and 2nd container attachment parts 30 Developer recovery device

Claims

1. a recording material storage section for storing recording materials; an image forming section that forms an image on the recording material sent out from the recording material storage section using a developer; a rotatable conveying member that conveys the recording material sent out from the recording material container toward the image forming unit; a developer recovery device capable of transporting recovered developer discharged from the image forming unit to a first recovered developer container and a second recovered developer container; a container mounting portion capable of holding the first recovered developer container and the second recovered developer container, the container mounting portion to which the first recovered developer container and the second recovered developer container are detachably mounted; In an image forming apparatus having When a direction substantially parallel to the rotation axis of the conveying member is defined as a depth direction of the image forming apparatus, and a direction substantially parallel to the horizontal direction in a cross section substantially perpendicular to the rotation axis of the conveying member is defined as a width direction of the image forming apparatus, an image forming apparatus, characterized in that the container mounting portion is capable of holding the first recovered developer container and the second recovered developer container lined up in the width direction below the image forming portion and above the recording material storage portion, so that more than half of the length of each of the first recovered developer container and the second recovered developer container in the depth direction and more than half of the length of each of the first recovered developer container and the second recovered developer container in the width direction are positioned in an area sandwiched between the image forming portion and the recording material storage portion.

2. 2. The image forming apparatus according to claim 1, wherein the container mounting section is capable of holding the first recovered developer container and the second recovered developer container side by side in the width direction so that the entire length of each of the first recovered developer container and the second recovered developer container in the width direction is positioned in an area sandwiched between the image forming section and the recording material storage section.

3. 3. The image forming apparatus according to claim 1, wherein the image forming unit includes a photosensitive member, a charging device that charges the photosensitive member, an exposure device that exposes the charged photosensitive member to light to form an electrostatic image on the photosensitive member, a developing device that develops the electrostatic image on the photosensitive member using a developer containing toner to form a toner image on the photosensitive member, an intermediate transfer member that transports the toner image that has been primarily transferred from the photosensitive member to a recording material for secondary transfer onto the recording material, and a fixing device that fixes the toner image that has been secondarily transferred onto the recording material.

4. 4. The image forming apparatus according to claim 3, wherein the container mounting section is capable of holding the first recovered developer container and the second recovered developer container side by side in the width direction so that more than half of the length of each of the first recovered developer container and the second recovered developer container in the depth direction and more than half of the length of each of the first recovered developer container and the second recovered developer container in the width direction are positioned in an area sandwiched between the intermediate transfer body and the recording material storage section.

5. 5. The image forming apparatus according to claim 4, wherein the container mounting section is capable of holding the first recovered developer container and the second recovered developer container side by side in the width direction so that the entire length of each of the first recovered developer container and the second recovered developer container in the width direction is positioned in an area sandwiched between the intermediate transfer body and the recording material storage section.

6. 6. The image forming apparatus according to claim 1, wherein the container mounting section is configured so that the first recovered developer container and the second recovered developer container can be attached and detached to and from the container mounting section by moving them respectively along the depth direction.

7. 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 developer recovery device based on detection results of the first sensor and the second sensor; and 7. The image forming apparatus according to claim 1, wherein the control unit controls the developer recovery device to switch the destination of the recovered developer by the developer recovery device from the first recovered developer container to the second recovered developer container 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 the developer recovery device is transporting the recovered developer to the first recovered developer container.

Images