JP5953820B2 - Image forming apparatus - Google Patents

Description

  The present invention relates to an image forming apparatus employing an electrophotographic system.

  An electrophotographic image forming apparatus includes an apparatus main body, a cartridge and a drum unit that are detachably attached to the apparatus main body, the cartridge includes a new toner box that stores unused toner, and the drum unit includes a photosensitive drum. There is known an image forming apparatus that integrally includes a drum cleaning unit that removes and collects waste toner from the surface of a photosensitive drum, and a waste toner box that stores waste toner.

  In such an image forming apparatus, waste toner generated on the surface of the photosensitive drum in the image forming process is collected by the drum cleaning unit and stored in the waste toner box.

  However, since such a waste toner box is integrally provided in the drum unit, it is replaced at the same time as the replacement of the drum unit. For this reason, the waste toner box needs to have a capacity corresponding to the life of the drum unit (photosensitive drum), and there is a limit to downsizing the waste toner box.

  On the other hand, in recent years, downsizing of an image forming apparatus is increasingly desired from the viewpoint of flexibility in installation location. Accordingly, various attempts have been made to reduce the size of the waste toner box. For example, a method has been proposed in which a new toner box and a waste toner box are integrally held in a cartridge.

  According to such a proposal, since the waste toner box is replaced at the same time as the replacement of the cartridge, it is sufficient to secure a capacity corresponding to a relatively short life of the cartridge with respect to the life of the drum unit. Miniaturization can be achieved.

  When the cartridge integrally holds the waste toner box as described above, the drum cleaning unit and the waste toner box are arranged at an interval in the circumferential direction of the photosensitive drum in a state where the cartridge and the drum unit are mounted on the apparatus main body. Is done.

  Therefore, in such an image forming apparatus, a transport unit for transporting the waste toner collected by the drum cleaning unit from the drum cleaning unit to the waste toner box is required.

  In an image forming apparatus including such a conveying unit, when the cartridge and the drum unit are configured to be detachable from the apparatus main body along the axial direction of the photosensitive drum, other members (for example, driving for driving the photosensitive drum) In consideration of an efficient arrangement of the units), the conveying means is arranged on the downstream side in the drawing direction with respect to the cartridge and the drum unit.

  As such an image forming apparatus, for example, the image forming apparatus main body, a photosensitive member rotatably supported by the image forming apparatus main body, and the image forming apparatus main body can be pulled out along the axial direction of the photosensitive member. A cleaning device that removes and collects waste toner from the surface of the photoreceptor, a waste toner storage device that stores waste toner recovered by the cleaning device, A developing device that accommodates unused toner, and a grip that includes a cleaning device and a downstream end of the developing device in the pull-out direction, and includes a toner conveying means that conveys waste toner from the cleaning device to the waste toner accommodating device. Has been proposed (see, for example, Patent Document 1).

  In such an image forming apparatus, in a state where the photosensitive member is supported by the image forming apparatus main body, the image forming unit (the cleaning device, the waste toner storage device, the developing device, and the handle) is connected to the image forming apparatus main body. Then, it is pulled out along the axial direction of the photoconductor and replaced.

Japanese Utility Model Publication No. 4-104668

  However, the cleaning device is generally in contact with the photoreceptor in order to remove and collect the waste toner from the surface of the photoreceptor. Therefore, when the cleaning device is moved with respect to the photoconductor, the toner may fall from the cleaning device, the photoconductor, or a contact portion thereof.

  That is, in the image forming apparatus described in Patent Document 1, the image forming unit, that is, the cleaning device or the like is pulled out from the image forming apparatus main body in a state where the photoconductor is supported by the image forming apparatus main body. The toner may fall from the cleaning device. As a result, the inside of the image forming apparatus main body and the outside of the image forming apparatus main body may be stained with toner.

  SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide an image forming apparatus that can prevent the inside of the apparatus main body and the outside of the apparatus main body from being contaminated with the developer while being able to be downsized.

(1) In order to achieve the above object, an image forming apparatus according to the present invention includes an apparatus main body, a photosensitive drum carrying a developer image, and drum cleaning for removing and collecting waste developer from the surface of the photosensitive drum. A drum unit that holds the unit and is accommodated in the apparatus main body, a waste developer accommodating portion for accommodating waste developer, a development unit for supplying developer to the photosensitive drum, and waste development from the drum cleaning unit And a first transport member for transporting the waste developer to the agent container.

  The developing unit is movable in a state where the drum unit is accommodated in the apparatus main body, drawn from the mounting position where the drum unit is mounted on the apparatus main body along the axial direction of the photosensitive drum, and moved away from the apparatus main body. At the mounting position, the drum cleaning unit is disposed in the circumferential direction of the photosensitive drum and spaced from the drum cleaning unit.

  The first conveying member can be moved integrally with the developing unit by connecting one end of the first conveying member to the downstream side in the drawing direction of the developing unit in the waste developer container, and the developing unit is positioned at the mounting position. In the state, the other end is connected to the downstream end of the drum cleaning unit in the pull-out direction, and the connection between the other end and the drum cleaning unit is released in the state where the developing unit is positioned at the separation position.

  According to such a configuration, since the developing unit that can be moved from the mounting position to the separation position includes the waste developer container, the waste unit is disposed in comparison with the case where the drum unit includes the waste developer container. It is possible to reduce the size of the developer accommodating portion, and consequently to reduce the size of the image forming apparatus.

  Further, the developing unit can be moved from the mounting position to the detaching position in a state where the drum unit holding the photosensitive drum and the drum cleaning unit is accommodated in the apparatus main body, so that the drum cleaning unit can be moved even if the developing unit is moved. , It does not move relative to the photosensitive drum.

  Therefore, the developer can be prevented from dropping from the photosensitive drum and the drum cleaning unit, and the inside of the apparatus main body and the outside of the apparatus main body can be suppressed from being contaminated with the developer.

Therefore, according to the image forming apparatus of the present invention, it is possible to suppress the inside of the apparatus main body and the outside of the apparatus main body from being stained with the developer while being able to reduce the size.
(2) Moreover, the other end part of the 1st conveyance member may be formed as an engaging part extended along an axial direction. In this case, the end of the drum cleaning unit on the downstream side in the pulling direction is engaged with the engaging portion when the developing unit is positioned at the mounting position, and is engaged when the developing unit is positioned at the detached position. An engaged portion that is disengaged from the portion is provided.

  According to such a configuration, the engaging portion of the first transport member and the engaged portion of the drum cleaning unit are engaged with each other in a state where the developing unit is located at the mounting position. Can be securely connected to the drum cleaning unit.

Further, since the engagement between the engaging portion and the engaged portion is released in the state where the developing unit is located at the disengaged position, the connection between the first transport member and the drum cleaning unit can be reliably released.
(3) Moreover, the engaging part may have an opening part and the shutter member which can open and close an opening part. In this case, the opening is closed by the shutter member in a state where the engagement between the engaging portion and the engaged portion is released.

According to such a configuration, since the opening is closed by the shutter member in a state where the engagement between the engaging portion and the engaged portion is released, the leakage of the waste developer from the opening is suppressed. it can. Therefore, it is possible to prevent the inside of the apparatus main body and the outside of the apparatus main body from being stained with the waste developer.
(4) In addition, an endless belt disposed opposite to the photosensitive drum, a belt cleaning unit that removes and collects the waste developer from the belt, and transports the waste developer from the belt cleaning unit to the waste developer container. And a second conveying member. In this case, one end of the second transport member is connected to the upstream end in the pulling direction in the waste developer container, and the other end is connected to the upstream end in the pulling direction in the belt cleaning unit.

  According to such a configuration, after the waste developer is removed and collected from the belt by the belt cleaning unit, the waste developer can be accommodated in the waste developer accommodating portion via the second conveying member. it can.

  That is, the waste developer recovered from the surface of the photosensitive drum and the waste developer recovered from the belt can be stored in a common waste developer storage unit.

  Therefore, it is possible to reduce the number of parts and to reduce the size of the image forming apparatus as compared with a case where a waste developer storage unit for storing the waste developer collected from the belt is separately provided. it can.

  The first transport member is disposed downstream of the development unit with respect to the waste developer container and the drum cleaning unit, and the second transport member is disposed with respect to the waste developer container and the drum cleaning unit. Since the developing unit is disposed on the upstream side in the drawing direction, an efficient arrangement of the first conveying member and the second conveying member can be ensured.

Therefore, the number of parts can be reduced, the image forming apparatus can be reduced in size, and an efficient arrangement of the first conveying member and the second conveying member can be ensured.
(5) Further, a plurality of photosensitive drums may be provided corresponding to a plurality of colors, and may be arranged in parallel at intervals in a direction orthogonal to the axial direction. In this case, the belt is disposed on the upper side of the plurality of photosensitive drums, and a plurality of developing units are provided corresponding to the plurality of photosensitive drums, respectively, and the lower side of the corresponding photosensitive drum in a state where the developing unit is located at the mounting position. Is arranged.

  According to such a configuration, a plurality of developing units supplies a developer corresponding to each of a plurality of colors (for example, yellow, magenta, cyan, and black) to a corresponding photosensitive drum, thereby forming a full-color image. Can be formed.

  In addition, since the developing unit is disposed below the photosensitive drum and the belt, the drum cleaning unit and the belt cleaning unit are disposed above the waste developer container.

  Therefore, when the waste developer is transported toward the waste developer container by the first transport member and the second transport member, gravity can be used, and the waste developer can be stably stabilized. Can be conveyed.

  In the image forming apparatus of the present invention, the inside of the apparatus main body and the outside of the apparatus main body can be prevented from being contaminated with the developer while the size can be reduced.

1 is a cross-sectional view illustrating a color printer as an embodiment of an image forming apparatus of the present invention. It is AA sectional drawing of the color printer shown in FIG. 1A is a cross-sectional view of the drum unit, and FIG. 1B is a front view of the drum unit. FIG. 3B is a cross-sectional view of the drum unit shown in FIG. 3A taken along line B-B, in which FIG. 3A shows a state where the drum unit side shutter is disposed at the closed position, and FIG. Shows the state of placement. 1 shows a state where the developing unit shown in FIG. 1 is pulled out from the main casing. 2 is a right side view of the developing unit shown in FIG. 1, (a) shows a right side view of the black developing unit, (b) shows a right side view of the black developing unit in a state where the developing device is removed, and (c) ) Shows a right side view of other developing units (yellow developing unit, magenta developing unit and cyan developing unit) in a state where the developing device is removed. FIG. 2 is a rear view of the developing unit shown in FIG. 1, wherein (a) shows a rear view of the black developing unit, and (b) shows other developing units (yellow developing unit, magenta developing unit and cyan developing unit). A rear view is shown.

1. Overall Configuration of Color Printer As shown in FIG. 1, a color printer 1 as an example of an image forming apparatus is a horizontal type intermediate transfer type color printer.

  The color printer 1 is a multi-function machine that is integrally provided with a main body casing 2 as an example of an apparatus main body and a flat bed scanner 3 that is provided on the upper side of the main body casing 2 and reads image information of a document.

In the main body casing 2, the color printer 1 includes a paper feeding unit 4 for feeding paper P and an image forming unit 5 for forming an image on the fed paper P.
(1) Main Body Casing As shown in FIGS. 1 and 2, the main body casing 2 is formed in a box shape that accommodates the paper feeding unit 4 and the image forming unit 5. A main body opening 8 (see FIG. 2) is formed on one side wall of the main body casing 2, and the front cover 6 (see FIG. 2) closes with the lower end of the front cover 6 as a fulcrum. (See FIG. 2) and an open position (see FIG. 5) where the main body opening 8 is opened so as to be swingable (movable).

  In the following description, the side on which the front cover 6 is provided (the left side in FIG. 2) is the front side, and the opposite side (the right side in FIG. 2) is the rear side. In addition, when the color printer 1 is viewed from the front side, the left and right reference is used.

That is, in FIG. 1, the left side of the drawing is the left side, and the right side of the drawing is the right side. Further, the front side of the page is the front side, and the back side of the page is the rear side.
(2) Paper Feed Unit The paper feed unit 4 includes a paper feed tray 7 that stores the paper P. The paper feed tray 7 is detachably attached to the bottom of the main casing 2.

The paper P stored in the paper feed tray 7 is sent between the paper feed roller 10 and the paper feed pad 11 by the rotation of the pickup roller 9, and is fed one by one by the rotation of the paper feed roller 10. Thereafter, the sheet P is fed toward the upper registration rollers 13 so as to sequentially pass between the sheet feeding roller 10 and each pinch roller 12 by the rotation of the sheet feeding roller 10. With the rotation of the registration roller 13, the image is supplied to the image forming unit 5 (between an intermediate transfer belt 38 (described later) and a secondary transfer roller 35 (described later)) at a predetermined timing.
(3) Image Forming Unit The image forming unit 5 is disposed on the upper side of the paper feeding unit 4 and includes a process unit 14, a transfer unit 18, and a fixing unit 19.
(3-1) Process Unit The process unit 14 is disposed on the upper side of the paper feed tray 7 and includes a drum unit 15, a developing unit 16, and a plurality (four) of LED units 17.
(3-1-1) Drum Unit The drum unit 15 is disposed at the upper end of the process unit 14, and integrally holds a photosensitive drum 21, a charging roller 22, and a drum cleaner 23 as an example of a drum cleaning unit. doing.

  A plurality (four) of photosensitive drums 21 are provided corresponding to a plurality of colors (black, yellow, magenta, cyan), and are arranged in parallel at intervals in the left-right direction.

  The charging roller 22 is provided corresponding to each of the four photosensitive drums 21 and is disposed on the lower right side of the corresponding photosensitive drum 21 so as to face and contact the photosensitive drum 21.

The drum cleaner 23 is provided corresponding to each of the four photosensitive drums 21 and is disposed on the right side of the corresponding photosensitive drum 21.
(3-1-2) Developing Unit A plurality (four) of developing units 16 are provided corresponding to each of a plurality (four) of photosensitive drums. Further, as will be described in detail later, the developing unit 16 is provided to be slidable in the front-rear direction at a mounting position where the developing unit 16 is mounted on the main casing 2 and a separation position where the developing unit 16 is detached from the main casing 2.

  Each of the plurality of developing units 16 is arranged below the corresponding photosensitive drum 21 in a state where it is located at the mounting position, and is arranged in parallel at intervals in the left-right direction. Specifically, a black developing unit 16K, a yellow developing unit 16Y, a magenta developing unit 16M, and a cyan developing unit 16C are sequentially arranged from the left side to the right side.

  The developing unit 16 includes a developing device 24 and a unit frame 25, which will be described in detail later.

  The developing device 24 is accommodated in the unit frame 25 and includes a developing roller 26.

  The developing roller 26 is rotatably supported at the upper end of the developing device 24 so as to be exposed from the upper side (upper right side), and is in contact with the photosensitive drum 21 from the lower left side.

The developing device 24 includes a supply roller 27 that supplies toner to the developing roller 26 and a layer thickness regulating blade 28 that regulates the thickness of the toner supplied to the developing roller 26. Further, the developing device 24 includes a toner storage unit 29 that stores toner as an example of a developer corresponding to each color (black, yellow, magenta, cyan) below the supply roller 27.
(3-1-3) LED Unit Each of the plurality of LED units 17 is arranged on the right side of the corresponding developing unit 16 and is supported by the main casing 2 so as to face the corresponding photosensitive drum 21 from below. . The LED unit 17 exposes the surface of the corresponding photosensitive drum 21 based on predetermined image data.
(3-2) Transfer Unit The transfer unit 18 is disposed above the process unit 14 and includes a belt unit 34 and a secondary transfer roller 35.

  The belt unit 34 is disposed along the left-right direction so as to face each of the four photosensitive drums 21 from above.

  The belt unit 34 includes a driving roller 36, a driven roller 37, an intermediate transfer belt 38 as an example of an endless belt, a plurality (four) of primary transfer rollers 39, and a belt cleaner 40 as an example of a belt cleaning unit. I have.

  The driving roller 36 and the driven roller 37 are arranged to face each other with a space in the left-right direction.

  The intermediate transfer belt 38 is disposed above the photosensitive drum 21 so that a lower portion thereof is opposed to and contacted with each of the four photosensitive drums 21, and is wound around the driving roller 36 and the driven roller 37. . In addition, the intermediate transfer belt 38 is rotated in such a way that the lower portion in contact with the photosensitive drum 21 moves from the left side to the right side by the driving of the driving roller 36 and the driven roller 37.

  Each of the plurality of primary transfer rollers 39 is provided to face the corresponding photosensitive drum 21 with the lower portion of the intermediate transfer belt 38 interposed therebetween.

  The belt cleaner 40 is disposed above the left end of the intermediate transfer belt 38, and includes a belt cleaning roller 72 and a counter roller 73, as will be described in detail later.

  The belt cleaning roller 72 is provided on the upper side of the intermediate transfer belt 38 so as to face the opposing roller 73 in the vertical direction with the intermediate transfer belt 38 interposed therebetween.

The secondary transfer roller 35 is provided on the right side of the belt unit 34 so as to face the driving roller 36 with the intermediate transfer belt 38 interposed therebetween.
(3-3) Fixing Unit The fixing unit 19 includes a heating roller 41 and a pressure roller 42 that is in pressure contact with the heating roller 41 from the upper right side. .
(3-4) Image Forming Operation (3-4-1) Developing Operation The toner in the developing device 24 is supplied to the supply roller 27 and further supplied to the developing roller 26.

  The toner supplied to the developing roller 26 is regulated by the layer thickness regulating blade 28 as the developing roller 26 rotates, and is carried on the surface of the developing roller 26 as a thin layer having a constant thickness.

  On the other hand, the surface of the photosensitive drum 21 is uniformly positively charged by the charging roller 22 as the photosensitive drum 21 rotates, and then exposed by the LED unit 17. As a result, an electrostatic latent image corresponding to the image to be formed on the paper P is formed on the surface of the photosensitive drum 21.

When the photosensitive drum 21 further rotates, the toner carried on the surface of the developing roller 26 is supplied to the electrostatic latent image formed on the surface of the photosensitive drum 21. As a result, the electrostatic latent image on the photosensitive drum 21 is visualized, and a toner image by reversal development is carried on the surface of the photosensitive drum 21.
(3-4-2) Transfer / Fixing Operation The toner image carried on the surface of the photosensitive drum 21 is primarily transferred sequentially to the lower portion of the intermediate transfer belt 38 that is moved from the left side to the right side. As a result, a color image is formed on the intermediate transfer belt 38.

  The color image formed on the intermediate transfer belt 38 is secondarily transferred onto the paper P supplied from the paper supply unit 4 while the intermediate transfer belt 38 passes through a position facing the secondary transfer roller 35.

The color image transferred onto the paper P is heat-fixed on the paper P in the fixing unit 19 by being heated and pressed while the paper P passes between the heating roller 41 and the pressure roller 42. Is done.
(4) Paper Discharge The paper P on which the toner image has been fixed in the fixing unit 19 is discharged by a paper discharge roller 44 onto a paper discharge tray 45 formed on the upper surface of the main casing 2.
(5) Flatbed Scanner The flatbed scanner 3 is provided above the paper discharge tray 45. In the flatbed scanner 3, after the original is placed between the presser cover 47 and the glass surface 48, the CCD sensor 49 slides to read the image information of the original.

Then, based on the read image information of the document, the image forming unit 5 can form an image on the paper P as described above.
2. Details of Main Body Casing As shown in FIG. 2, the main body casing 2 includes an outer casing 80 that forms the outer shape of the color printer 1 and an inner casing 81 that is provided inside the outer casing 80.

  The outer casing 80 is formed in a substantially box shape that is substantially rectangular in a side view, and includes a front cover 6 at the front end.

  The inner casing 81 is formed in a substantially box shape that is substantially rectangular in side view. The inner casing 81 has a vertical length and a horizontal length that can accommodate the paper feed unit 4 (see FIG. 1) and the image forming unit 5, and is spaced apart from the outer casing 80 on the rear side. The outer casing 80 is accommodated so as to be packed on the front side.

  Further, the inner space of the inner casing 81 is partitioned by a partition wall 111.

  The partition wall 111 is formed in a substantially flat plate shape, and is provided between the paper feed tray 7 and the developing unit 16 in the vertical direction. The inner space of the inner casing 81 is divided into the upper unit accommodating space 115 and the lower paper feed tray. The housing space 116 is partitioned.

  A holding member 20 is provided on the upper surface of the partition wall 111.

  As shown in FIGS. 1 and 2, four holding members 20 are provided so as to correspond to the four developing units 16.

  As shown in FIG. 2, the holding member 20 is formed in a substantially U shape in front view and a substantially tray shape extending in the front-rear direction, and the upper and front sides are open. The holding member 20 is formed so that the inner surface thereof conforms to the outer shape of the lower end portion of the unit frame 25, and the inner dimension (the length in the left-right direction and the length in the front-rear direction) is the outer dimension (the length in the left-right direction) of the unit frame 25. And the length in the front-rear direction).

Specifically, as shown in FIG. 1, the holding member 20 is formed such that the vertical length of the left wall is longer than the vertical length of the right wall, and an inner portion of the connecting portion between the left wall and the lower wall is formed. The side surface is formed in a substantially arc shape when viewed from the front along the outer shape of the lower end portion of the waste toner container 31.
3. Details of Drum Unit (1) Drum Frame As shown in FIG. 2, the drum unit 15 includes a pair of drum frames 51 that are opposed to each other with an interval in the front-rear direction.

  As shown in FIGS. 3A and 3B, the drum frame 51 is formed in a substantially flat plate shape that is long in the left-right direction, and a unit groove 52 is formed in a lower portion thereof.

  The unit groove 52 is formed by cutting out a portion that overlaps the upper end of the developing device 24 of the developing unit 16 when projected in the front-rear direction (see FIG. 1).

  Specifically, the unit groove 52 corresponding to the black developing unit 16K extends from the center in the vertical direction at the left end edge of the drum frame 51 toward the right, and then inclines downward toward the right. It is missing and formed.

  The unit grooves 52 corresponding to the other developing units 16Y, 16M, and 16C (the yellow developing unit 16Y, the magenta developing unit 16M, and the cyan developing unit 16C) are notched upward from the lower end edge of the drum frame 51. Further, it is formed in a substantially U shape that is open downward.

  Further, among the pair of drum frames 51, the front drum frame 51 has a plurality of (four) insertion ports 53, as shown in FIG. 3B, and a plurality of drum-side receiving cylinders 56 (described later). Are formed at intervals in the left-right direction.

  The insertion port 53 is formed in a portion that overlaps a drum-side receiving cylinder 56 (described later) when projected in the front-rear direction, and is formed in a substantially circular shape in front view that penetrates the drum frame 51 in the front-rear direction. The hole diameter of the insertion port 53 is slightly larger than the outer diameter of the drum pipe side shutter 101 (described later).

  Further, between the pair of drum frames 51, the photosensitive drum 21, the charging roller 22, and the drum cleaner 23 are supported.

  As shown in FIG. 4A, the photosensitive drum 21 is formed in a substantially cylindrical shape extending in the front-rear direction, and both front and rear ends thereof are rotatably supported by the drum frame 51, respectively.

  Further, a drum gear 181 as a drive input unit is provided at the rear end of the photosensitive drum 21. The drum gear 181 is connected to driving means (not shown) provided in the main casing 2, and a driving force for rotating the photosensitive drum 21 is input from the driving means (not shown).

The charging roller 22 is formed in a substantially cylindrical shape extending in the front-rear direction, and both front and rear ends thereof are rotatably supported by a drum frame 51 (described later).
(2) Drum Cleaner The drum cleaner 23 includes a drum waste toner reservoir 54 and a cleaning blade 55 as shown in FIG.

  As shown in FIGS. 3A and 4A, the drum waste toner reservoir 54 is formed in a substantially rectangular shape that is vertically long when viewed from the front and extends in the front-rear direction. . Further, the lower wall of the drum waste toner reservoir 54 is formed in a substantially semicircular arc shape in front view that bulges downward along a rotation locus of a first auger screw 58 (described later).

  In the drum waste toner reservoir 54, an opening 57 is formed in the left wall (see FIG. 3A), and a drum waste toner discharge port 62 is formed in the lower wall (see FIG. 4A).

  As shown in FIG. 3A, the opening 57 is formed through the left wall of the drum waste toner reservoir 54 in the left-right direction.

  As shown in FIG. 4A, the drum waste toner discharge port 62 communicates between the drum waste toner storage portion 54 and the drum side receiving cylinder 56 (described later) at the front end portion of the lower wall of the drum waste toner storage portion 54. It is formed so as to penetrate in the vertical direction.

  A first auger screw 58 is provided in the drum waste toner reservoir 54.

  The first auger screw 58 is formed so as to extend in the front-rear direction, and is disposed along the lower wall of the drum waste toner reservoir 54 (see FIG. 3A). The front end portion of the first auger screw 58 is rotatably supported on the front wall of the drum waste toner storage portion 54, and the rear end portion thereof is rotatably supported on the rear wall of the drum waste toner storage portion 54. .

  Further, the drum waste toner storage portion 54 is integrally provided with a front side fixing portion 59, a rear side fixing portion 60, and a drum side receiving cylinder 56 as an example of an engaged portion.

  The front fixing portion 59 is formed in a substantially box shape having a substantially rectangular shape when viewed from the front, and is provided on the front wall of the drum waste toner storage portion 54. The vertical length of the front fixing portion 59 is shorter than the vertical length of the drum waste toner storage portion 54.

  The rear side fixing portion 60 is formed in a substantially box shape having a substantially rectangular shape when viewed from the front, and is provided on the rear wall of the drum waste toner storage portion 54. The vertical length of the rear fixing portion 60 is formed to be approximately the same as the vertical length of the drum waste toner storage portion 54.

  The drum-side receiving cylinder 56 is formed in a substantially cylindrical shape extending in the front-rear direction and closed at the rear end portion, and is continuous with the front end portion of the lower wall of the drum waste toner storage portion 54 in the upper portion thereof. . Further, the inner diameter of the drum-side receiving cylinder 56 is formed to be substantially the same as the outer diameter of the drum-side engaging portion 99 (described later).

  The drum side receiving cylinder 56 includes a drum unit side shutter 63.

  The drum unit side shutter 63 is formed in a substantially cylindrical shape whose front end is closed, and is accommodated in the drum side receiving cylinder 56. The outer diameter of the drum unit side shutter 63 is formed to be substantially the same as the inner diameter of the drum side receiving cylinder 56. The drum unit side shutter 63 is disposed at the rear end portion of the drum side receiving cylinder 56 so as to open the drum waste toner discharge port 62 in the drum side receiving cylinder 56 (see FIG. 4B). And a slidable position (see FIG. 4A) disposed at the front end of the drum-side receiving cylinder 56 so as to close the drum waste toner discharge port 62.

  A compression spring 64 is interposed between the rear wall of the drum-side receiving cylinder 56 and the front wall of the drum unit-side shutter 63, and the drum unit-side shutter 63 is always directed to the front side by the compression spring 64. And is placed in the closed position (see FIG. 4A).

  As shown in FIG. 3A, the cleaning blade 55 is formed in a substantially flat plate shape extending in the vertical direction, and its lower end portion so that its upper end portion (free end portion) contacts the photosensitive drum 21 from the right side. The (base end) is fixed to the left peripheral edge of the opening 57 in the left wall of the drum waste toner reservoir 54.

In the drum cleaner 23, as shown in FIG. 4A, the front end portion of the front fixing portion 59 is fixed to the front drum frame 51, and the rear end portion of the rear fixing portion 60 is fixed to the rear drum frame 51. As a result, the drum frame 51 is held.
4). Details of Belt Unit (1) Belt Cleaner The belt cleaner 40 includes a belt cleaner frame 50 as shown in FIG.

  The belt cleaner frame 50 is formed in a substantially U shape in a side view opened upward, and is disposed between a pair of side walls 66 opposed to each other with a space in the front-rear direction and a lower end portion of the pair of side walls 66. And a covering wall 67 for erected.

  As shown in FIG. 1, the side wall 66 is formed in a substantially flat plate shape that is long in the left-right direction.

  Between the pair of side walls 66, a belt waste toner collecting unit 65 and a belt waste toner storage unit 68 are held.

  The belt waste toner collecting unit 65 includes a belt cleaning roller 72 and a relay roller 74.

  The belt cleaning roller 72 is formed in a substantially cylindrical shape extending in the front-rear direction, and both front and rear ends thereof are rotatably supported by a pair of side walls 66, respectively. The covering wall 67 is notched so as to expose the lower portion of the belt cleaning roller 72, and the belt cleaning roller 72 is opposed to the opposing roller 73 in the vertical direction with the intermediate transfer belt 38 interposed therebetween. Is arranged.

  The relay roller 74 is disposed on the left side of the belt cleaning roller 72 so as to contact the belt cleaning roller 72 from the left side. Further, as shown in FIG. 2, the relay roller 74 is formed in a substantially cylindrical shape extending in the front-rear direction, and both front and rear end portions thereof are rotatably supported by a pair of side walls 66, respectively.

  The belt waste toner reservoir 68 extends in the front-rear direction, and is formed in a substantially box shape whose front and rear ends are each closed by a pair of side walls 66 (see FIG. 1).

  Further, as shown in FIG. 1, the belt waste toner reservoir 68 has an opening 69 penetrating in the left-right direction in the lower portion of the right wall.

  A second auger screw 71 is provided in the belt waste toner storage unit 68. As shown in FIG. 5, the second auger screw 71 is formed to extend in the front-rear direction, and its front end is rotatably supported by the front side wall 66, and its rear end is supported by the rear side wall 66. It is rotatably supported.

  The belt waste toner reservoir 68 is provided with a scraping blade 75 as shown in FIG. The scraping blade 75 is formed in a substantially flat plate shape extending in the vertical direction, and the upper end (base end) of the scraping blade 75 is a belt waste so that the lower end (free end) contacts the relay roller 74 from the left side. It is fixed to the right peripheral edge of the opening 69 in the right wall of the toner reservoir 68.

  The belt waste toner reservoir 68 is connected to a belt waste toner transport pipe 70 as an example of a second transport member.

  As shown in FIG. 5, the belt waste toner conveyance pipe 70 is formed in a substantially pipe shape, and a substantially coil spring-shaped screw 82 is accommodated therein. Further, the belt waste toner conveying pipe 70 is formed in a substantially U shape in a side view in which both upper and lower ends are bent forward, and is integrally formed from a belt side connecting portion 76, a midway portion 77, and a developing side engaging portion 78. Has been.

  The belt side connecting portion 76 is an upper end portion of the belt waste toner conveying pipe 70 and extends in the front-rear direction. The front end portion shares the central axis with the second auger screw 71 and is disposed in the belt waste toner storage portion 68. Is fixed to the rear side wall 66, and its rear end extends so as to penetrate the rear wall of the inner casing 81.

  The intermediate portion 77 bends downward from the rear end portion of the belt side connecting portion 76. Specifically, as shown in FIG. 1, the middle portion 77 is inclined downward as it goes leftward from the rear end portion of the belt side connecting portion 76. After that, it bends and extends downward. That is, when projected in the front-rear direction, the middle portion 77 bends in a substantially L shape when viewed from the front so as to retract from the projection surface of the leftmost photosensitive drum 21 among the plurality (four) of photosensitive drums 21. ing.

  Further, as shown in FIG. 5, the intermediate portion 77 is disposed between the rear wall of the outer casing 80 and the rear wall of the inner casing 81.

  The developing side engaging portion 78 is a lower end portion of the belt waste toner transport pipe 70, is bent forward from the lower end portion of the midway portion 77, and extends so as to penetrate the rear wall of the inner casing 81.

  Further, a belt waste toner discharge port 79 is formed in the development side engaging portion 78. The belt waste toner discharge port 79 is formed to penetrate in the vertical direction at the front end portion of the lower side portion of the developing side engaging portion 78.

  Further, the developing side engaging portion 78 includes a belt pipe side shutter 83.

  The belt pipe side shutter 83 is formed in a substantially cylindrical shape extending in the front-rear direction, and is fitted to the developing side engaging portion 78 from the outside. Further, the inner diameter of the belt pipe side shutter 83 is formed to be substantially the same diameter (slightly larger) as the outer diameter of the developing side engaging portion 78. The belt pipe side shutter 83 has an open position (see FIG. 2) disposed at the rear end portion of the developing side engaging portion 78 so as to open the belt waste toner discharge port 79, and the belt waste toner discharge port 79. It is slidably provided at a closed position (see FIG. 5) disposed at the front end of the developing side engaging portion 78 so as to be closed. That is, the belt pipe side shutter 83 can open and close the belt waste toner discharge port 79.

A compression spring 84 is interposed between the rear end portion of the belt pipe side shutter 83 and the rear wall of the inner casing 81, and the belt pipe side shutter 83 is always moved forward by the compression spring 84. It is urged | biased toward and is arrange | positioned in the closed position (refer FIG. 5).
5). Details of Developing Unit (1) Unit Frame As shown in FIG. 1, the unit frame 25 is formed in a substantially rectangular shape when viewed from the front, and its right side portion is partitioned as a developing device accommodating portion 32, and its left side portion is waste development. A waste toner container 31 as an example of the agent container is defined.
(1-1) Developing Device Housing Unit The developing device housing portion 32 is formed in a length in the front-rear direction capable of housing the developing device 24 as shown in FIG. Further, as shown in FIG. 6 (b), the developing device accommodating portion 32 is formed in a substantially U-shape that is opened upward, and the front wall 105 and the rear wall that are opposed to each other with an interval in the front-rear direction. The wall 106 and the lower wall 104 constructed between those lower end parts are provided.

  As shown in FIGS. 7A and 7B, the front wall 105 and the rear wall 106 are formed in a substantially flat plate shape having a substantially rectangular shape when viewed from the back.

  A guide hole 107 is formed in each of the front wall 105 and the rear wall 106.

  Two guide holes 107 are formed at portions corresponding to bosses 88 (described later) of the developing device 24, and two guide holes 107 are formed at intervals in the vertical direction. The guide hole 107 is formed in an approximately elliptical shape when viewed from the back, and is formed so as to extend along the facing direction of the photosensitive drum 21 and the developing roller 26 (see FIG. 1). The guide hole 107 has a major axis that is approximately 1.5 times as long as an outer diameter of a corresponding boss 88 (described later), and a minor diameter of the guide hole 107 is an outer diameter of the corresponding boss 88 (described later). And approximately the same diameter.

  Further, as shown in FIGS. 6A to 6C, a grip portion 120 for attaching and detaching the developing unit 16 to the main body casing 2 is formed on the front wall 105.

  The grip portion 120 is formed in a substantially rectangular shape in a side view extending forward from the lower end portion of the front surface of the front wall 105.

  As shown in FIG. 1, the lower wall 104 is provided with a spring support portion 108.

  The spring support portion 108 is formed in a substantially triangular shape in front view extending in the front-rear direction. The spring support portion 108 is provided at the left end portion of the lower wall 104, and the upper surface facing the outer surface of the toner storage portion 29 is formed as a curved surface 110 when the developing device 24 is stored in the developing device storage portion 32. Has been. The curved surface 110 is formed in a substantially arc shape in front view that curves upward as it goes to the left.

  The spring support 108 is provided with a coil spring 109.

  As shown in FIG. 6B, the coil spring 109 is formed in an air-core coil shape, and its axial direction is substantially parallel to the facing direction of the photosensitive drum 21 and the developing roller 26 (see FIG. 1). The front and rear ends of the curved surface 110 are respectively fixed.

  Further, as shown in FIG. 6A, the developing device accommodating portion 32 accommodates the developing device 24.

  The developing device 24 is formed in a hollow cylindrical shape extending in the front-rear direction (see FIG. 1), and its front end is closed by a front wall 86 and its rear end is closed by a rear wall 87.

  In the present embodiment, the configurations relating to the front wall 86 and the rear wall 87 are the same. Therefore, in the following description, the rear wall 87 will be described in detail, and description of the front wall 86 will be omitted.

  A boss 88 is provided on the rear wall 87.

  As shown in FIGS. 6A and 7A, the boss 88 is formed in a substantially cylindrical shape that protrudes rearward from the rear wall 87. In the left portion of the rear wall 87, the boss 88 is spaced apart in the vertical direction. Two are provided apart. Further, the upper boss 88 has a larger diameter than the lower boss 88 as shown in FIG.

  As shown in FIG. 6A, the developing device 24 is accommodated in the developing device accommodating portion 32 so that the boss 88 is inserted from the inside into the corresponding guide hole 107. As a result, the developing device 24 is accommodated in the developing device so as to be relatively movable along the opposing direction of the photosensitive drum 21 and the developing roller 26 (see FIG. 1) by guiding the bosses 88 into the corresponding guide holes 107. It is accommodated in the part 32.

Further, as shown in FIG. 1, the coil spring 109 is disposed between the spring support portion 108 and the outer surface of the toner storage portion 29 of the developing device 24.
(1-2) Waste Toner Storage Unit The waste toner storage unit 31 is formed in a substantially box shape having a substantially rectangular shape when viewed from the front in the vertical direction, and is connected to the left end of the developing device storage unit 32.

  As shown in FIGS. 6B and 6C, the waste toner container 31 includes a third auger screw 89.

  The third auger screw 89 extends in the front-rear direction and is disposed on the upper portion of the waste toner storage unit 31 (see FIG. 1), and is rotatably supported on the front wall of the waste toner storage unit 31 at the front end thereof. The rear end portion is rotatably supported by the rear wall of the waste toner storage unit 31. Further, the rear end portion of the third auger screw 89 passes through the rear wall of the waste toner storage portion 31, and the coupling 95 is held so as not to rotate relative to the through portion.

  As shown in FIG. 6B, the third auger screw 89 in the black developing unit 16K is formed so that the spiral winding direction is reversed between the front half and the rear half. On the other hand, the third auger screw 89 in the other developing units 16Y, 16M, 16C (yellow developing unit 16Y, magenta developing unit 16M and cyan developing unit 16C) has a spiral winding direction as shown in FIG. Are formed in the same direction.

  The waste toner container 31 (hereinafter referred to as waste toner container 31K) in the black developing unit 16K has an insertion port 112 and a development side receiving cylinder 90 as shown in FIG. 6B. ing.

  The insertion port 112 is formed to penetrate in the front-rear direction at the upper end portion of the rear wall of the waste toner storage portion 31K. The hole diameter of the insertion port 112 is formed to be substantially the same diameter (slightly larger) as the outer diameter of the developing side engaging portion 78.

  The development side receiving cylinder 90 is formed in a substantially cylindrical shape extending forward from the peripheral end portion of the insertion port 112, and the front end portion thereof is closed. That is, the development side receiving cylinder 90 is disposed in the waste toner storage unit 31K.

  Further, a belt waste toner receiving port 92 is formed in the lower portion of the developing side receiving tube 90.

  The belt waste toner receiving port 92 is formed so as to penetrate in the vertical direction at the rear end portion of the lower portion of the developing side receiving cylinder 90 so as to communicate the waste toner container 31K and the developing side receiving cylinder 90.

  Further, the developing side receiving cylinder 90 includes a developing side shutter 91.

  The development-side shutter 91 is formed in a substantially cylindrical shape extending in the front-rear direction and closed at the rear end, and is accommodated in the development-side receiving cylinder 90. The outer diameter of the development side shutter 91 is formed to be substantially the same as the inner diameter of the development side receiving cylinder 90. The developing side shutter 91 has an open position (see FIG. 2) disposed at the front end portion of the developing side receiving cylinder 90 so as to open the belt waste toner receiving port 92 in the developing side receiving cylinder 90, and a belt waste. The toner receiving port 92 is slidably provided at a closed position (see FIG. 6B) disposed at the rear end portion of the developing side receiving cylinder 90 so as to close the toner receiving port 92.

  A compression spring 93 is interposed between the front wall of the development side receiving cylinder 90 and the rear wall of the development side shutter 91, and the development side shutter 91 is always moved rearward by the compression spring 93. It is biased toward the end and is disposed at the closed position (see FIG. 6B).

  The waste toner storage unit 31 is connected to a drum waste toner transport pipe 96 as an example of a first transport member.

  As shown in FIGS. 2 and 6A to 6C, the drum waste toner conveying pipe 96 is formed in a substantially pipe shape, and a substantially coil spring-shaped screw 94 is accommodated therein. (See FIG. 1). 2 is a cross-sectional view taken along the line AA of the color printer shown in FIG. 1, but the entire drum waste toner transport pipe 96 is shown in FIG. 2 for convenience of explanation.

  Further, as shown in FIG. 6A, the drum waste toner transport pipe 96 is formed in a substantially U shape in plan view with both front and rear end portions bent toward the rear side, It is integrally formed from the part 98 and the drum side engaging part 99 as an example of an engaging part (refer FIG. 2).

  The accommodating portion side connecting portion 97 is a left end portion of the drum waste toner conveying pipe 96 and extends in the front-rear direction. The rear end portion shares the central axis with the third auger screw 89 and is disposed in the waste toner accommodating portion 31. Is fixed to the front wall of the waste toner container 31. As a result, the drum waste toner transport pipe 96 can move integrally with the developing unit 16.

  The midway portion 98 is bent rightward from the front end portion of the accommodating portion side connecting portion 97 and extends so as to incline upward toward the right (see FIG. 1).

  The drum-side engagement portion 99 extends from the right end portion of the midway portion 98 by bending backward. The drum side engaging portion 99 is formed with a drum waste toner receiving port 100 as an example of an opening.

  The drum waste toner receiving port 100 is formed so as to penetrate in the vertical direction at the rear end portion in the upper portion of the drum side engaging portion 99.

  The drum side engaging portion 99 includes a flange portion 102 and a drum pipe side shutter 101 as an example of a shutter member.

  The flange portion 102 is provided on the outer peripheral surface of the front side portion of the drum side engagement portion 99 and is formed in a substantially annular plate shape that extends radially outward of the drum side engagement portion 99.

  The drum pipe side shutter 101 is formed in a substantially cylindrical shape extending in the front-rear direction, and is fitted to the drum side engagement portion 99 from the outside. Further, the inner diameter of the drum pipe side shutter 101 is formed to be substantially the same diameter (slightly larger) as the outer diameter of the drum side engaging portion 99. The drum pipe-side shutter 101 has an open position (see FIG. 4B) disposed at the front end of the drum-side engagement portion 99 so as to open the drum waste toner receiving port 100, and a drum waste toner receiving port. It is slidably provided at a closed position (see FIG. 6A) disposed at the rear end portion of the drum side engaging portion 99 so as to close 100. That is, the drum pipe side shutter 101 can open and close the drum waste toner receiving port 100.

A compression spring 103 is interposed between the front end portion of the drum pipe side shutter 101 and the front side surface of the flange portion 102, and the drum pipe side shutter 101 is always moved rearward by the compression spring 103. It is urged | biased toward and it has arrange | positioned in the closed position (refer Fig.6 (a)).
6). Next, the attaching / detaching operation of the developing unit 16 with respect to the main casing 2 will be described.

  In order to attach the developing unit 16 to the main casing 2, as shown in FIG. 5, first, the front cover 6 is positioned at the open position, and the grip portion 120 is gripped toward the unit housing space 115. The developing unit 16 is inserted from the front side.

  Then, the lower end portion of the unit frame 25 of the developing unit 16 is inserted into the holding member 20 from the front side. That is, the holding member 20 is disposed so as to support the unit frame 25 from below, and the developing unit 16 is guided by the holding member 20 and moved along the front-rear direction. At this time, the developing device 24 passes through the corresponding unit groove 52.

  Further, when the developing unit 16 is moved rearward with respect to the main casing 2, as shown in FIG. 4B, the drum pipe side shutter 101 passes through the insertion port 53 from the front side, and the drum pipe side shutter 101. The upper portion of the rear end portion is in contact with the lower side of the front end portion of the drum waste toner storage portion 54, and the rear end portion of the drum side engaging portion 99 is in contact with the front end portion of the drum unit side shutter 63.

  When the developing unit 16 is further moved rearward, the drum pipe side shutter 101 is pressed forward against the urging force of the compression spring 103 by the drum waste toner reservoir 54 and is disposed at the open position. Is done.

  At this time, the drum side engaging portion 99 is inserted into the drum side receiving cylinder 56 until the drum waste toner discharge port 62 and the drum waste toner receiving port 100 are opposed to each other in the vertical direction. That is, the drum side engaging portion 99 is fitted (engaged) in the drum side receiving cylinder 56.

  Accordingly, the drum pipe side shutter 101 and the drum unit side shutter 63 are disposed at the open position, and the drum waste toner discharge port 62 and the drum waste toner receiving port 100 are opposed to each other in the vertical direction and communicate with each other.

  That is, as shown in FIG. 1, the drum waste toner transport pipe 96 has a left end portion (rear end portion of the accommodating portion side connecting portion 97) connected to a front end portion of the waste toner accommodating portion 31 and a right end portion (drum side). The rear end portion of the engaging portion 99 is connected to the front end portion of the drum waste toner storage portion 54.

  Further, as shown in FIG. 2, when the black developing unit 16 </ b> K is inserted into the unit accommodating space 115 from the front side, the peripheral end portion of the insertion port 112 in the rear wall 106 is in front of the front end portion of the belt pipe side shutter 83. And the rear end portion of the developing side shutter 91 is in contact with the front end portion of the developing side engaging portion 78 (see FIGS. 5 and 6B).

  When the black developing unit 16K is further moved rearward, the peripheral end portion of the insertion port 112 presses the belt pipe side shutter 83 rearward against the urging force of the compression spring 84, and the belt pipe side The shutter 83 is disposed at the open position.

  At this time, the developing side engaging portion 78 is inserted into the developing side receiving cylinder 90 until the belt waste toner discharge port 79 and the belt waste toner receiving port 92 are opposed to each other in the vertical direction. That is, the developing side engaging portion 78 and the developing side receiving cylinder 90 are fitted (engaged).

  As a result, the belt pipe side shutter 83 and the development side shutter 91 are disposed in the open position, and the belt waste toner discharge port 79 and the belt waste toner receiving port 92 face each other in the vertical direction and communicate with each other.

  That is, as shown in FIG. 1, the belt waste toner transport pipe 70 has a left end (front end of the developing side engaging portion 78) connected to a rear end of the waste toner containing portion 31 and a right end (belt side). The rear end portion of the connecting portion 76 is connected to the rear end portion of the belt waste toner storage portion 68 (see FIG. 2).

  Thus, the mounting of the developing unit 16 to the main casing 2 (unit housing space 115) is completed, and the developing unit 16 is positioned at the mounting position.

  At this time, the developing unit 16 is arranged at a distance from the drum cleaner 23 in the circumferential direction of the photosensitive drum 21.

  In addition, in order to detach the developing unit 16 from the main casing 2 (unit accommodating space 115), the procedure is reversed to the above-described mounting operation.

  Then, as shown in FIG. 5, the developing unit 16 is guided by the holding member 20 and pulled out from the unit accommodating space 115 to the front side. As a result, the developing unit 16 is positioned at a separation position where the developing unit 16 is detached from the main casing 2 (unit accommodation space 115).

  That is, the direction in which the developing unit 16 is attached to and detached from the main body casing 2 and the axial direction of the photosensitive drum 21 are the same direction (front-rear direction), and the developing unit 16 is in a state where the drum unit 15 is accommodated in the main body casing 2. It is pulled out from the mounting position along the front-rear direction and can be moved to the separation position.

  At this time, the engagement (engagement) between the drum side engaging portion 99 of the drum waste toner conveying pipe 96 and the drum side receiving cylinder 56 (see FIG. 4B) of the drum waste toner storing portion 54 is released. As a result, the connection between the drum side engaging portion 99 and the drum waste toner storing portion 54 is released. Further, the engagement (engagement) between the developing side engaging portion 78 of the belt waste toner conveying pipe 70 and the developing side receiving cylinder 90 (see FIG. 6B) of the waste toner containing portion 31K is released. The connection between the developing side engaging portion 78 and the waste toner containing portion 31K is released.

  The drum pipe-side shutter 101 is disposed at the closed position by the compression spring 103 (see FIG. 6A), and the belt pipe-side shutter 83 is disposed at the closed position by the compression spring 84.

  That is, as shown in FIG. 6A, the drum waste toner receiving port 100 is released from the engagement (engagement) between the drum side engaging portion 99 and the drum side receiving cylinder 56 (see FIG. 4B). In this state, the drum pipe side shutter 101 is closed. Further, as shown in FIG. 5, the belt waste toner discharge port 79 is in a state where the engagement (engagement) between the developing side engaging portion 78 and the developing side receiving cylinder 90 (see FIG. 6B) is released. 1 is closed by a belt pipe side shutter 83.

Thus, the attachment and detachment of the developing unit 16 with respect to the main casing 2 (unit accommodation space 115) is completed.
7). Waste toner collection and storage (cleaning operation)
When the image forming operation of the color printer 1 is started, as shown in FIG. 1, the first auger screw 58 (FIG. 4A and FIG. 4) is driven by a driving force from a driving source (motor) (not shown) in the main casing 2. 4 (b)), the second auger screw 71 (see FIG. 5), the third auger screw 89 (see FIG. 6 (b) and FIG. 6 (c)), the screw 94 in the drum waste toner conveying pipe 96, And the screw 82 in the belt waste toner conveyance pipe 70 rotates.

  In the image forming operation of the color printer 1, as described above, the toner image carried on the surface of the photosensitive drum 21 is primarily transferred sequentially to the lower portion of the intermediate transfer belt 38 that is moved from the left side to the right side. The

  At this time, after the primary transfer to the lower part of the intermediate transfer belt 38, the transfer residual toner (waste toner) remains on the surface of the photosensitive drum 21 without being transferred to the paper P.

  When the photosensitive drum 21 rotates, the waste toner on the photosensitive drum 21 is scraped off by the cleaning blade 55 and falls into the drum waste toner storage unit 54 through the opening 57.

  That is, the cleaning blade 55 removes waste toner from the surface of the photosensitive drum 21 and collects it in the drum waste toner storage unit 54.

  Thereafter, the waste toner that has fallen into the drum waste toner storage unit 54 (waste toner collected by the cleaning blade 55) is stored in the drum waste toner storage unit 54, as shown in FIG. By the rotation of the first auger screw 58, the belt waste toner reservoir 68 is conveyed forward. Then, the waste toner that has reached the front end of the belt waste toner reservoir 68 falls into the drum-side engagement portion 99 from the drum waste toner discharge port 62 through the drum waste toner receiving port 100 due to gravity.

  As shown in FIG. 6B, the waste toner that has fallen into the drum side engaging portion 99 passes through the intermediate portion 98 from the drum side engaging portion 99 by the rotation of the screw 94 (see FIG. 1). It is conveyed to the connecting part 97.

  Then, the waste toner conveyed into the storage unit side connection unit 97 is transported into the waste toner storage unit 31 by the rotation of the third auger screw 89.

  That is, the drum waste toner transport pipe 96 transports the waste toner from the drum waste toner storage unit 54 to the waste toner storage unit 31.

  Thereafter, the waste toner transported into the waste toner storage portion 31K of the black developing unit 16K is transported rearward by the rotation of the third auger screw 89 and stored in the central portion in the front-rear direction of the waste toner storage portion 31K. The

  On the other hand, the waste toner transported into the waste toner storage unit 31 of the other developing units 16Y, 16M, and 16C is transported rearward by the rotation of the third auger screw 89, and the rear side of the waste toner storage unit 31 Contained in the part.

  Next, as described above, the color image formed on the intermediate transfer belt 38 is applied to the paper P supplied from the paper feeding unit 4 while the intermediate transfer belt 38 passes through the position facing the secondary transfer roller 35. Secondary transfer.

  At this time, after the color image is secondarily transferred to the paper P, residual transfer toner (waste toner) remains on the intermediate transfer belt 38. When the waste toner faces the belt cleaning roller 72 due to the circumferential movement of the intermediate transfer belt 38, the waste toner is collected from the intermediate transfer belt 38 to the peripheral surface of the belt cleaning roller 72. As a result, the waste toner is removed from the intermediate transfer belt 38.

  Thereafter, when the waste toner carried on the peripheral surface of the belt cleaning roller 72 faces the relay roller 74 as the belt cleaning roller 72 rotates, the toner is discarded from the peripheral surface of the belt cleaning roller 72 to the peripheral surface of the relay roller 74. Toner adheres.

  When the relay roller 74 rotates, the waste toner on the peripheral surface of the relay roller 74 is scraped off by the scraping blade 75 and falls into the belt waste toner storage unit 68.

  Thereafter, the waste toner that has fallen into the belt waste toner storage unit 68 is stored in the belt waste toner storage unit 68 as shown in FIG. 5, and the belt waste toner storage unit is rotated by the rotation of the second auger screw 71. The belt 68 is conveyed rearward and is sent from the belt waste toner reservoir 68 to the belt waste toner conveyance pipe 70.

  The waste toner sent into the belt waste toner transport pipe 70 is transported by the screw 82 from the belt side connecting portion 76 to the developing side engaging portion 78 via the intermediate portion 77.

  Then, the waste toner conveyed into the developing side engaging portion 78 is fed from the belt waste toner discharge port 79 through the belt waste toner receiving port 92 by gravity, and is sent to the waste toner containing portion 31K (the waste of the black developing unit 16K). The toner falls into the toner container 31).

  Thereafter, as shown in FIG. 6B, the waste toner that has fallen into the waste toner container 31K is conveyed forward by the rotation of the third auger screw 89, and the center of the waste toner container 31K in the front-rear direction. Contained in the part.

  That is, the belt waste toner transport pipe 70 transports the waste toner from the belt waste toner storage unit 68 to the waste toner storage unit 31.

Thus, the cleaning operation of the color printer 1 is completed.
8). Effect (1) In the color printer 1, as shown in FIG. 5, the developing unit 16 is mounted in the unit housing space 115 of the main casing 2 in a state where the drum unit 15 is stored in the main casing 2. And a disengagement position where the main body casing 2 is disengaged from the unit accommodating space 115. Therefore, the developing unit 16 having a shorter life than the drum unit 15 (photosensitive drum 21) can be replaced independently of the drum unit 15.

  Since the developing unit 16 includes the waste toner storage unit 31, the waste toner storage unit 31 can be downsized as compared with the case where the drum unit 15 includes the waste toner storage unit 31. As a result, the color printer 1 can be miniaturized.

  Further, the drum cleaner 23 does not move relative to the photosensitive drum 21 even when the developing unit 16 is moved from the attachment position to the separation position.

  Therefore, it is possible to suppress the toner from dropping from the photosensitive drum 21 and the drum cleaner 23, and it is possible to suppress the inside of the main body casing 2 and the outside of the main body casing 2 from being stained with toner.

Therefore, according to the color printer 1, the inside of the main body casing 2 and the outside of the main body casing 2 can be prevented from being contaminated with toner, while the size can be reduced.
(2) Further, as shown in FIG. 2, the drum waste toner transport pipe 96 has a right end portion formed as a drum side engaging portion 99 extending along the front-rear direction. As shown in FIG. 4B, a drum-side receiving cylinder 56 is provided at the front end of the drum waste toner storage portion 54 (the end on the downstream side in the drawing direction of the developing unit 16).

  Then, in a state where the developing unit 16 is located at the mounting position, the drum side engaging portion 99 is fitted (engaged) in the drum side receiving cylinder 56, and in a state where the developing unit 16 is located at the detached position. As shown in FIG. 5, the engagement (engagement) between the drum side engaging portion 99 and the drum side receiving cylinder 56 is released.

Therefore, in the state where the developing unit 16 is located at the mounting position, as shown in FIG. 4B, the drum waste toner transport pipe 96 and the drum cleaner 23 can be reliably connected, and the developing unit 16 is located at the detached position. In this state, as shown in FIG. 5, the connection between the drum waste toner transport pipe 96 and the drum cleaner 23 can be reliably released.
(3) The drum side engaging portion 99 has a drum waste toner receiving port 100 and a drum pipe side shutter 101, as shown in FIGS. 6 (b) and 6 (c).

The drum waste toner receiving port 100 is closed by the drum pipe side shutter 101 in a state where the engagement (engagement) between the drum side engaging portion 99 and the drum side receiving cylinder 56 is released. Leakage of waste toner from the toner receiving port 100 can be suppressed. Therefore, it is possible to suppress the inside of the main casing 2 and the outside of the main casing 2 from being contaminated with waste toner.
(4) Further, as shown in FIG. 1, the color printer 1 includes an intermediate transfer belt 38, a belt cleaner 40, and a belt waste toner transport pipe 70. The left end portion of the belt waste toner transport pipe 70 is connected to the rear wall 106 (upstream end portion in the pulling direction of the developing unit 16) of the waste toner storage portion 31K, and the right end portion is on the rear side of the belt cleaner 40. The side wall 66 is connected to the upstream end of the developing unit 16 in the drawing direction.

  Therefore, after the waste toner is removed and collected from the intermediate transfer belt 38 by the belt cleaner 40, the waste toner can be stored in the waste toner storage unit 31 via the belt waste toner transport pipe 70.

  That is, the waste toner collected from the surface of the photosensitive drum 21 and the waste toner collected from the intermediate transfer belt 38 can be stored in the common waste toner storage unit 31.

  Therefore, the color printer 1 can be reduced in size while the number of parts can be reduced as compared with the case where a waste toner storage unit 31 for storing the waste toner collected from the intermediate transfer belt 38 is separately provided. be able to.

  As shown in FIG. 2, the drum waste toner transport pipe 96 is disposed on the front side (downstream in the pulling direction of the developing unit 16) with respect to the waste toner storage unit 31 and the drum cleaner 23, and the belt waste toner transport pipe. 70 is disposed on the rear side (upstream in the direction in which the developing unit 16 is pulled out) with respect to the waste toner storage unit 31 and the drum cleaner 23. Therefore, the efficiency of the drum waste toner transport pipe 96 and the belt waste toner transport pipe 70 Can be ensured.

  Further, in the main casing 2, on the rear side of the drum unit 15 and the developing unit 16, although not shown, driving means (not shown) for transmitting driving force to the drum gear 118 (see FIG. 4A) of the photosensitive drum 21. For example, a gear train) is arranged.

  On the other hand, since the drum waste toner transport pipe 96 is disposed on the front side with respect to the drum unit 15 and the developing unit 16, the drum waste toner transport pipe 96 is an obstacle to the arrangement of the driving means (for example, gear train). Can be suppressed.

  On the other hand, the belt waste toner transport pipe 70 is arranged on the rear side with respect to the drum unit 15 and the developing unit 16, but when the middle portion 77 of the belt waste toner transport pipe 70 is projected in the front-rear direction, a plurality of ( Among the four photosensitive drums 21, the photosensitive drum 21 is bent so as to be retracted from the projection surface of the leftmost photosensitive drum 21, so that it is possible to suppress the disposition of the driving means (for example, gear train). As a result, the space in the main body casing 2 can be used effectively.

Therefore, the number of parts can be reduced, the color printer 1 can be reduced in size, and the efficient arrangement of the drum waste toner transport pipe 96 and the belt waste toner transport pipe 70 can be ensured. Can do.
(5) In addition, as shown in FIG. 1, a plurality (four) of photosensitive drums 21 are provided corresponding to a plurality of colors (black, yellow, magenta, cyan), and are arranged in parallel in the left-right direction at intervals. Has been placed. Further, toner corresponding to each color (black, yellow, magenta, cyan) is stored in the toner storage unit 29 of the developing device 24.

  Then, a plurality (four) of the developing units 16 supply toner corresponding to each of a plurality of colors (for example, yellow, magenta, cyan, and black) to the corresponding photosensitive drums 21, thereby forming a full-color image. be able to.

  Further, since the developing unit 16 is disposed below the photosensitive drum 21 and the intermediate transfer belt 38, the drum cleaner 23 and the belt cleaner 40 are disposed above the waste toner storage unit 31.

  Therefore, when the waste toner is transported toward the waste toner container 31 by the drum waste toner transport pipe 96 and the belt waste toner transport pipe 70, gravity can be used, and the waste developer can be stably stabilized. It can be conveyed to the accommodating part 31.

DESCRIPTION OF SYMBOLS 1 Color printer 2 Main body casing 15 Drum unit 16 Development unit 21 Photosensitive drum 23 Drum cleaner 31 Waste toner accommodating part 38 Intermediate transfer belt 40 Belt cleaner 56 Drum side receiving cylinder 70 Waste belt toner conveyance pipe 96 Drum waste toner conveyance pipe 99 Drum insertion part 100 Drum waste toner receiving port 101 Drum pipe side shutter

Claims (4)

The device body;
A drum unit that holds a photosensitive drum carrying a developer image, and a drum cleaning unit that removes and collects the waste developer from the surface of the photosensitive drum, and is housed in the apparatus main body;
A development unit for supplying a developer to the photosensitive drum, comprising a waste developer storage unit for storing the waste developer;
A first transport member for transporting waste developer from the drum cleaning unit to the waste developer container ;
An endless belt disposed opposite to the photosensitive drum;
A belt cleaning unit that removes and collects the waste developer from the belt; and
A second transport member for transporting the waste developer from the belt cleaning unit to the waste developer container ,
The developing unit is
In a state where the drum unit is housed in the apparatus main body, the drum unit is pulled out from the mounting position at which the drum unit is mounted along the axial direction of the photosensitive drum, and can be moved to a separation position at which the drum unit is detached from the apparatus main body. ,
In the mounting position, the drum cleaning unit is disposed in the circumferential direction of the photosensitive drum and spaced apart from the photosensitive drum.
The first conveying member is
One end portion is connected to the downstream side of the developing unit in the waste developer accommodating portion in the pulling-out direction of the developing unit, so that it can move integrally with the developing unit,
When the developing unit is positioned at the mounting position, the other end is connected to the downstream end of the drum cleaning unit in the pull-out direction, and when the developing unit is positioned at the detached position, the other end is connected. And the drum cleaning unit is disconnected ,
The second conveying member is
One end is connected to the upstream end in the pulling direction in the waste developer container, and the other end is connected to the upstream end in the pulling direction in the belt cleaning unit.
The image forming apparatus , wherein the drum cleaning unit maintains a relative position with respect to the photosensitive drum when the developing unit moves from the mounting position to the separation position . The first conveying member is formed as an engaging portion whose other end extends along the axial direction.
A state where the developing unit is engaged with the engaging portion and the developing unit is positioned at the disengaged position at the downstream end of the drum cleaning unit in the pulling direction in the state where the developing unit is positioned at the mounting position. The image forming apparatus according to claim 1, further comprising an engaged portion that is disengaged from the engaging portion. The engaging portion has an opening and a shutter member capable of opening and closing the opening,
The opening is
The image forming apparatus according to claim 2, wherein the shutter is closed by the shutter member in a state where the engagement between the engagement portion and the engaged portion is released. A plurality of the photosensitive drums are provided corresponding to a plurality of colors, and are arranged in parallel at intervals from each other in a direction orthogonal to the axial direction.
The belt is disposed on the upper side of the plurality of photosensitive drums,
The developing unit includes a plurality provided corresponding to each of the plurality of photosensitive drums in a state of being positioned in the mounting position, characterized in that it is arranged on the lower side of the corresponding photosensitive drum, according to claim 1 the image forming apparatus according to any one of to 3.

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