JP6230495B2 - Developing device and image forming apparatus - Google Patents

Description

  The present invention relates to a developing device that uses a developer and an image forming apparatus, and more particularly to a configuration of an opening / closing mechanism for a developer passage opening.

  Conventionally, for example, when opening and closing the discharge port of the toner recovery device, the discharge port formed in the cylindrically formed storage portion has an opening that can be opposed to the discharge port, and is provided to the peripheral surface of the storage portion. There is a configuration including a shutter member that opens and closes the discharge port while sliding (see, for example, Patent Document 1).

JP 2008-286820 A (5th page, FIG. 4)

  However, even when the discharge port is closed, there is a problem in that the toner stored in the storage unit leaks from the discharge port through a gap in the sliding portion.

The developing device according to the present invention comprises:
A developer removing member for removing the developer attached to the image carrier;
A waste developer container having a container for storing the developer removed by the developer removing member, and having a discharge port for discharging the stored developer to the outside;
A developer conveying member that conveys the developer accommodated in the accommodating portion toward the discharge port;
A cylindrical portion disposed opposite to the discharge port; and a seal member disposed on an outer peripheral surface of the cylindrical portion, and is disposed so as to be rotatable about an axis parallel to the developer conveyance direction. A shutter for opening and closing the discharge port;
The cylindrical portion extends in the conveying direction before Kigen image agent in the receptacle, and an opening facing the exhaust outlet during the discharge open mouth, on the upstream side in the transport direction than the opening, than the outer diameter of the portion opening is formed to have a large diameter portion of larger outer diameter,
The seal member is interposed between the waste developer accommodating portion and the cylindrical portion, and has a region having an outer diameter of a portion of the cylindrical portion where the opening is formed and a region having an outer diameter of the large-diameter portion. The crushing amount of the region having the outer diameter of the large-diameter portion is larger than the crushing amount of the other regions .

  According to the present invention, it is possible to prevent the contained developer from leaking from the closed discharge port while suppressing an increase in the rotational load of the shutter that opens and closes the discharge port.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic configuration diagram for explaining a main configuration of an image forming apparatus according to a first embodiment that employs the present invention. FIG. 2 is a schematic configuration diagram schematically showing a black (K) image drum unit together with a transfer roller, a transfer belt, a recording sheet on which toner development is transferred, and an exposure device. It is the external appearance perspective view which looked at the image drum unit from diagonally downward. 4A and 4B are cross-sectional views of the AA cross section passing through the toner discharge port in FIG. 3 as viewed from the same direction, in which FIG. 3A shows a state where the toner discharge port is closed and FIG. 3B shows a state where the toner discharge port is opened. (A) is an external perspective view of the shutter, (b) is an external perspective view of the rotating member excluding the seal sponge, and (c) is an external perspective view of the seal sponge. FIG. 4 is a partially enlarged view of the vicinity of the toner discharge port shown in FIG. 3 with the image drum unit tilted by about 90 °, where (a) shows a state where the toner discharge port is closed, and (b) shows a toner discharge port. Is shown in the open state.

Embodiment 1 FIG.
Embodiment 1 FIG.
FIG. 1 is a schematic configuration diagram for explaining a main configuration of an image forming apparatus according to a first embodiment employing the present invention.

  In FIG. 1, an image forming apparatus 100 is configured as a color electrophotographic printer capable of printing four colors of black (K), yellow (Y), magenta (M), and cyan (C). Inside, a substantially reverse S-shaped paper conveyance path 15 having paper conveyance roller pairs 16 to 19 is formed, and a paper feed cassette for storing recording paper at the upstream end of the paper conveyance path 15. 20 is disposed, and a stacker 21 is provided at the downstream end.

  The paper transport path 15 has a hopping roller, a paper feed unit 22 that feeds the recording paper from the paper feed cassette 20, a detection unit 26 that detects the paper thickness of the recording paper, and transfers the fed recording paper by electrostatic effect. A transfer belt unit 24 that adheres and conveys the belt 11 and a fixing device 25 that fixes the toner image onto the recording paper are provided.

  Black (K) and yellow (Y) in order from the upstream side in the conveyance direction of the recording paper at a position sandwiching the recording paper 13 (FIG. 2) attached to the transfer belt 11 and conveyed in the direction of the arrow by the transfer belt unit 24. , Image drum units 23K, 23Y, 23M, and 23C as developing devices for forming magenta (M) and cyan (C) toner images are formed in a row. Toner cartridges 27K, 27Y, 27M, and 27C that contain toner as a developer of the corresponding color are arranged in each image drum unit 23 (if there is no particular need to distinguish them). A toner cartridge 27 is detachably mounted. Note that, like the image drum unit 23 of the image forming apparatus 100, a part other than the detachable or movable constituent elements other than the constituent elements may be referred to as the main body of the image forming apparatus 100.

  For example, by opening the top cover 30 of the image forming apparatus 100, the toner cartridge 27, the image drum unit 23, the fixing device 25, the transfer belt unit 24, and the like are moved in the vertical direction so that they can be exchanged.

  In this embodiment, the configuration of each image drum unit 23 and each toner cartridge 27 is the same, and only the color of the toner used is different. Therefore, here, the black (K) image drum unit 23K is taken as an example, and The internal structure will be described below.

  Note that the X, Y, and Z axes in FIG. 1 take the X axis in the transport direction when the recording paper passes through the image drum unit 23, and take the Y axis in the rotational axis direction of the photosensitive drum 1 described later. The Z axis is taken in a direction perpendicular to both the axes. Moreover, when each axis | shaft of X, Y, and Z is shown in the other figure mentioned later, these axial directions shall show a common direction. That is, the XYZ axes in each drawing indicate the arrangement direction when the depicted portion of each drawing constitutes the image forming apparatus 100 shown in FIG. Here, it is assumed that the Z-axis is arranged in a substantially vertical direction.

  FIG. 2 is a schematic configuration diagram schematically showing a black (K) image drum unit 23 </ b> K together with the transfer roller 12, the transfer belt 11, the recording paper 13 onto which toner development has been transferred, and the exposure device 3.

  As shown in the figure, in the image drum unit 23K, a photosensitive drum 1 as an image carrier is rotatably arranged in the direction of the arrow, and around the photosensitive drum 1 in order from the upstream side in the rotation direction. Based on the print data, a charging roller 2 that contacts the surface of the photosensitive drum 1 with a certain pressure to supply and charge the surface of the photosensitive drum 1 and light from a light source such as an LED head is applied to the charged surface of the photosensitive drum 1. An exposure device 3 is provided for forming an electrostatic latent image by irradiation.

  Further, a developing unit 41 that generates toner by attaching toner of a predetermined color (here, black) to the surface of the photosensitive drum 1 on which the electrostatic latent image is formed, and toner development on the photosensitive drum 1 is performed on recording paper. A cleaning blade 9 serving as a developer removing member that removes the transfer residual toner 38 remaining when the toner image is transferred to 13 and drops the toner to a waste toner container 42 serving as a waste developer container is fixed to the lower frame 10. ing. For this reason, the cleaning blade 9 is formed of an elastic body, and the edge portion thereof is disposed so as to contact the surface of the photosensitive drum 1 with a constant pressure.

  Here, the waste toner storage portion 42 is formed at the inner lower portion of the lower frame 10 as a frame constituting a part of the outer casing of the image drum unit 23K. The waste toner storage portion 42 stores the waste toner storage portion 42 as described later. A conveying spring 4 as a developer conveying member that conveys the transferred residual toner 38 toward a toner discharge port 51 (see FIG. 3) formed in the waste toner accommodating portion 42 is rotatably disposed.

  The developing unit 41 includes a toner storage unit 45 that stores the toner supplied from the toner cartridge 27K (FIG. 1) mounted on the upper portion, a developing roller 6 that contacts the photosensitive drum 1 with a constant pressure, and the developing roller 6 An electrostatic latent image formed on the surface of the photosensitive drum 1 by the developing roller 6 having toner supplying rollers 7 and 8 for supplying toner and a developing blade 5 for uniformly thinning the toner on the developing roller 6. Is developed with a thinned toner, that is, developed.

  The image drum unit 23K is configured such that the toner cartridge 27K (FIG. 1) is detachably disposed in the mounting portion 33 above the developing portion 41.

  The developing roller 6 and the toner supply rollers 7 and 8 are arranged in parallel with each other so as to be in contact with each other at a constant pressure, and rotate in the directions of the arrows (same direction) shown in the figure. Further, as shown in the figure, the developing blade 5 and the developing roller 6 are arranged in parallel to each other so that, for example, a bent portion of the developing blade 5 is in contact with the peripheral surface of the developing roller 6 with a constant pressure. Note that the rotating body used in each of these devices rotates by receiving power from a drive source (not shown) via a gear or the like.

  As shown in FIG. 1, transfer rollers 12 formed of conductive rubber or the like are placed on the recording paper 13 (FIG. 2) at positions facing the respective photosensitive drums 1 of the four image drum units 23 described above. They are arranged in pressure contact with each other via a transfer belt 11 that is electrostatically absorbed and conveyed. These transfer rollers 12 transfer the toner development on the photosensitive drum 1 onto the recording paper 13 (FIG. 2). At the time of this transfer, these transfer rollers 12 are supplied with the surface potential of the corresponding photosensitive drum 1. A voltage for applying a predetermined potential difference between them is applied.

  The fixing device 25 includes a heating roller and a backup roller inside, and fixes the transferred toner 14 transferred onto the recording paper 13 (FIG. 2) by applying pressure and heating. The recording sheet 13 fixed here is conveyed to a recording sheet stacker 21 by a pair of sheet conveying rollers 18 and 19 at the subsequent stage.

  In the above configuration, first, the operation of the image forming apparatus 100 will be described with reference to FIG.

  When printing is started, the image forming apparatus 100 feeds the recording paper from the paper feed cassette 20 by the paper feeding unit 22 shown in FIG. 1 and transports the recording paper downstream along the paper transport path 15. Then, in the middle of the paper conveyance path, the paper thickness of the recording paper is detected by the detection unit 26 that detects the paper thickness, and is conveyed by the transfer belt unit 24 in the direction of the arrow. In this conveyance process, the toner images of the respective colors individually formed by the image drum units 23K, 23Y, 23M, and 23C are sequentially transferred onto the recording surface of the recording paper by the transfer roller 12, and further transferred by the fixing unit 25. The image is fixed on the recording surface, and the fixed recording paper is conveyed to the stacker 21.

  The operation of the image drum unit 23 at this time will be described below with reference to FIG.

  In the image drum unit 23, the toner supplied from the toner cartridge 27 (FIG. 1) is supplied to the developing roller 6 by the toner supply rollers 7 and 8, and the toner supplied to the developing roller 6 is equalized to a uniform thickness by the developing blade 5. The Then, the electrostatic latent image formed on the photosensitive drum 1 based on the print data is visualized, that is, developed by the uniformized toner by the exposure device 3. The toner developed on the photosensitive drum 1 is electrically transferred to the recording paper 13 by the transfer roller 12. On the other hand, the untransferred toner 38 that is not transferred onto the recording paper 13 but remains on the surface of the photosensitive drum 1 is scraped off by the cleaning blade 9 and accumulated in the waste toner container 42.

  Next, the configuration of the toner discharge port 51 formed in the waste toner container 42 and the shutter 60 that opens and closes the toner discharge port 51 will be further described.

  3 is an external perspective view of the image drum unit 23 as viewed obliquely from below, and FIG. 4 is a cross-sectional view of the AA cross section passing through the toner discharge port 51 in FIG. 4A shows a state in which the toner discharge port 51 is closed, and FIG. 4B shows a state in which the toner discharge port 51 is opened.

  The waste toner storage portion 42 formed on the lower frame 10 is disposed along the axial direction (Y-axis direction) of the photosensitive drum 1 and in contact with the peripheral surface of the photosensitive drum 1 over the entire area in the axial direction. A toner receiving portion 43 (FIG. 2) that is formed to face the cleaning blade 9 (FIG. 2) and receives the transfer residual toner 38 scraped off by the cleaning blade 9, and outside the axial region of the peripheral surface of the photosensitive drum 1. And a toner discharge portion 44 (FIG. 4) formed in a cylindrical shape. The toner receiving portion 43 and the toner discharging portion 44 correspond to a storage portion that stores toner.

  In the toner discharge portion 44, a toner discharge port 51 is formed vertically downward as a discharge port communicating with the outside. The conveyance spring 4 (FIG. 2) disposed in the waste toner storage portion 42 extends in the axial direction (Y-axis direction) of the photosensitive drum 1 inside the waste toner storage portion 42, and rotates to rotate. The untransferred toner 38 (FIG. 2) dropped on the toner receiving portion 43 of the waste toner containing portion 42 is conveyed toward the toner discharge port 51 of the toner discharge portion 44.

  The toner discharge portion 44 is formed with a shutter slide portion 44a that is formed in a cylindrical shape inside and has a toner discharge port 51 on its inner peripheral surface. The shutter slide portion 44a includes a cylindrical portion 62 of the shutter 60. (FIG. 5B) is slidably fitted.

  5A is an external perspective view of the shutter 60, FIG. 5B is an external perspective view of the rotating member 61 excluding the seal sponge 65, and FIG. 5C is an external perspective view of the seal sponge 65. FIG.

  As shown in FIG. 5B, the shutter 60 shown in FIG. 5A includes a rotating member 61 having a hollow cylindrical portion 62 and a lever portion 63, and a seal member attached to the rotating member 61. As a sealing foam 65 made of urethane foam.

  The cylindrical portion 62 is formed continuously with the lever portion 63, and has a small-diameter portion 62 a in which an opening 62 c is formed and a distal end side (an opposite side of the lever portion 63) from the small-diameter portion 62. And a large diameter portion 62b having a larger outer diameter than the portion 62a. The opening 62c is formed at a position that can face the toner discharge port 51 when the shutter 60 is mounted on the toner discharge portion 44 of the waste toner storage portion 42 as will be described later. The small diameter portion 62a and the large diameter portion 62b are flush with each other on the hollow inner peripheral surface.

  The lever portion 63 includes a shaft portion 63a serving as a rotation shaft of the shutter 60 and an engagement portion 63b for receiving a force from the outside when the shutter 60 rotates.

  As shown in FIG. 5C, the seal sponge 65 is formed in a cylindrical shape here, and its inner diameter is formed slightly smaller than the outer diameter of the small-diameter portion 62a of the rotating member 61. An opening 65a is formed. Further, when the seal sponge 65 is mounted so as to cover the cylindrical portion 62a of the rotating member 61 as shown in FIG. At this time, since the seal sponge 65 needs to be fixed to the outer peripheral surface of the cylindrical portion 62, it is preferable to fix the seal sponge 65 with a double-sided adhesive tape, for example.

  At this time, the opening 65a of the seal sponge 65 and the opening 62c of the rotating member 61 overlap, and the outer peripheral surface thereof is slightly stepped by the influence of the small diameter portion 62a and the large diameter portion 62b of the rotating member 61. The shape and thickness are taken into consideration so that the above occurs.

  Here, the seal sponge 65 is formed in a cylindrical shape, but may be formed in a band shape so as to be wound around the cylindrical portion 62 of the rotating member 61 with a double-sided adhesive.

  As shown in the sectional view of FIG. 4, the cylindrical portion 62 of the shutter 60 is fitted into the shutter sliding portion 44 a of the toner discharge portion 44 of the waste toner storage portion 42, and the inner peripheral surface 62 d of the cylindrical portion 62 and the toner discharge portion. 44 is flush with the inner peripheral surface 44b, and the seal sponge 65 is between the cylindrical portion 62 of the shutter 60 and the shutter sliding portion 44a of the toner discharge portion 44, and is compressed and compressed by a predetermined amount. Thus, the dimensions of each part are considered. As shown in FIG. 4, the large diameter portion 62 b of the shutter 60 is positioned upstream of the toner discharge port 51 of the toner discharge portion 44 in the waste toner conveyance direction (arrow D direction).

  Further, as shown in FIG. 4, the crushing amount (compression amount) of the seal sponge 65 is necessarily larger in the region of the large diameter portion 62 b than the small diameter portion 62 a of the cylindrical portion 62. On the other hand, the shaft portion 63a of the lever portion 63 of the shutter 60 is fitted into a bearing hole 10a formed in the lower frame 10 and is held rotatably. Thereby, the shutter 60 rotates around the shaft portion 63a while the inner peripheral surface of the shutter sliding portion 44a and the seal sponge 65 slide while the cylindrical portion 62 is fitted in the shutter sliding portion 44a. It is possible to move.

  FIG. 4A shows a state where the rotation position of the shutter 60 is in a closed position in which the peripheral surface of the small diameter portion 62 a closes the toner discharge port 51 of the toner discharge unit 44 and closes the toner discharge port 51. 4B shows a state where the rotation position of the shutter 60 is in the open position where the opening 62c of the small diameter portion 62a overlaps the toner discharge port 51 of the toner discharge unit 44 and opens the toner discharge port 51. FIG. .

  Further, the shutter 60 is urged in the direction of the arrow B toward the closed position shown in FIG. 4A by a torsion spring 67 as an urging member spanned between the lever portion 63 and the lower frame 10, This closed position is configured to be maintained by a regulating means that does not.

  FIG. 6 is a partially enlarged view of the vicinity of the toner discharge port 51 shown in FIG. 3 with the image drum unit 23 tilted by about 90 °. 6A shows a state in which the toner discharge port 51 is closed, and FIG. 6B shows a state in which the toner discharge port 51 is opened.

  Therefore, as shown in FIGS. 4A and 6A, for example, against the urging by the torsion spring 67 from the state where the shutter 60 is in the closed position and the toner discharge port 51 is closed, for example, The engaging portion 63b of the lever portion 63 shown in FIG. 6 (a) is rotated in the direction of arrow C by a member engaged therewith, and the shutter 60 is shown in FIGS. 4 (b) and 6 (b). Is rotated to the open position, the toner discharge port 51 can be opened.

  For example, when the image drum unit 23 configured as described above is separated from the main body of the image forming apparatus 100 and exists alone, the shutter 60 is urged to the closed position by the torsion spring 67 and the toner discharge port 51 is closed. When the image forming apparatus 100 is mounted on the image forming apparatus 100, an engaged portion (not shown) disposed on the image forming apparatus 100 main body engages with the engaging portion 63b of the shutter 60 and rotates in the direction of arrow C. When the mounting is completed, the toner is rotated to the open position, and the toner discharge port 51 is opened.

  In this state, the untransferred toner 38 (FIG. 2) that has dropped onto the toner receiving portion 43 of the waste toner containing portion 42 is conveyed to the toner discharge port 51 of the toner discharge portion 44 by the transfer spring 4, and sequentially from the toner discharge port 51. Then, the toner falls into a predetermined waste toner storage unit disposed in the main body of the image forming apparatus 100.

  When the image drum unit 23 is removed from the main body of the image forming apparatus 100 again, in this process, the engaging state of the engaging portion 63b of the lever portion 63 and the engaged portion (not shown) provided in the main body of the image forming apparatus 100 is engaged. At the stage of releasing, the shutter 60 is urged to the closed position by the urging force of the torsion spring 67, and the toner discharge port 51 is closed again.

  In the present embodiment, the top cover 30 is opened, and the image forming apparatus 100 configured to attach and detach the toner cartridge 27 and the image drum unit 23 in the vertical direction (Z-axis direction) is shown. For example, in FIG. 1, the toner cartridge 27 and the image drum unit 23 are slid along the Y axis from the front side (the positive side of the Y axis) in FIG. It can be taken as various forms, such as the one that has been made.

  As described above, according to the image drum unit 23 of the present embodiment, the gap between the shutter sliding portion 44a of the toner discharge portion 44 of the waste toner storage portion 42 and the cylindrical portion 62 of the shutter 60 is crushed (compressed). The toner discharge port 51 is closed because a region with a large crushing amount (compression amount) exists on the upstream side of the toner discharge port 51 in the toner conveyance direction. In this state, it is possible to prevent the waste toner in the waste toner container 42 from leaking.

  Further, in the sliding region between the shutter sliding portion 44a of the toner discharge portion 44 and the seal sponge 65, the region where the crushing amount (compression amount) of the seal sponge 65 is large is limited to a part (large diameter portion 62b). Thus, an increase in rotational load when the shutter 60 is rotated to open and close the toner discharge port 51 is suppressed, and for example, the shutter 60 smoothly closes the toner discharge port 51 by the urging force of the torsion spring 67. Can be maintained.

  In this embodiment, the color printer is used as the image forming apparatus. However, the present invention can be applied to a single color printer, a copying machine, a FAX, and a complex machine in which these are combined.

DESCRIPTION OF SYMBOLS 1 Photosensitive drum, 2 Charging roller, 3 Exposure apparatus, 4 Conveying spring, 5 Developing blade, 6 Developing roller, 7 Toner supplying roller, 8 Toner supplying roller, 9 Cleaning blade, 10 Lower frame, 10a Bearing hole, 11 Transfer belt , 12 transfer roller, 13 recording paper, 14 transferred toner, 15 paper transport path, 16 paper transport roller pair, 17 paper transport roller pair, 18 paper transport roller pair, 19 paper transport roller pair, 20 paper feed cassette, 21 stacker , 22 sheet feeding unit, 23 image drum unit, 24 transfer belt unit, 25 fixing unit, 26 detection unit, 27 toner cartridge, 30 top cover, 33 mounting unit, 38 transfer residual toner, 41 developing unit, 42 waste toner storage unit, 43 Toner receiving part, 44 Toner discharge 44a Shutter sliding part, 45 Toner storage part, 51 Toner discharge port, 60 Shutter, 61 Rotating member, 62 Cylindrical part, 62a Small diameter part, 62b Large diameter part, 62c Opening, 62d Inner peripheral surface, 63 Lever part 63a Shaft portion, 63b engaging portion, 65 seal sponge, 65a opening, 67 torsion spring, 100 image forming apparatus.

Claims (5)

A developer removing member for removing the developer attached to the image carrier;
A waste developer container having a container for storing the developer removed by the developer removing member, and having a discharge port for discharging the stored developer to the outside;
A developer conveying member that conveys the developer accommodated in the accommodating portion toward the discharge port;
A cylindrical portion disposed opposite to the discharge port; and a seal member disposed on an outer peripheral surface of the cylindrical portion, and is disposed so as to be rotatable about an axis parallel to the developer conveyance direction. A shutter for opening and closing the discharge port,
The cylindrical portion extends in the conveying direction before Kigen image agent in the receptacle, and an opening facing the exhaust outlet during the discharge open mouth, on the upstream side in the transport direction than the opening, than the outer diameter of the portion opening is formed to have a large diameter portion of larger outer diameter,
The seal member is interposed between the waste developer accommodating portion and the cylindrical portion, and has a region having an outer diameter of a portion of the cylindrical portion where the opening is formed and a region having an outer diameter of the large-diameter portion. The developing device is characterized in that the crushing amount of the region having the outer diameter of the large-diameter portion is larger than the crushing amount of the other region .   The developing device according to claim 1, further comprising an urging member that urges the shutter in a direction to close the discharge port.   The developing device according to claim 1, wherein the waste developer container is formed in a frame of the developing device.   The developing device according to claim 1, wherein the shutter includes an engaging portion for receiving an external force for rotating the cylindrical portion. An image forming apparatus characterized by comprising any one of the developing apparatus according to claim 1 to 4.

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