JP5350194B2 - Electrophotographic image forming apparatus - Google Patents

Description

  The present invention relates to an electrophotographic image forming apparatus having a support member to which a plurality of cartridges are detachably mounted.

  2. Description of the Related Art An electrophotographic image forming apparatus using an electrophotographic image forming process is known that employs a system in which various components are made into cartridges and can be attached to and detached from the apparatus main body. Specifically, there is a cartridge in which at least one of an electrophotographic photosensitive member, process means acting on the electrophotographic photosensitive member, and a storage portion for storing toner is formed as a cartridge. According to this cartridge system, the maintenance of the apparatus can be performed by the user himself / herself without depending on the service person, so that the operability can be greatly improved. For this reason, this cartridge system is often used in electrophotographic image forming apparatuses.

  With regard to such a configuration for attaching and detaching a cartridge, there is a method of pulling out a cartridge placed on a support member and attaching and detaching the cartridge (see Patent Documents 1 and 2). When such a cartridge system is adopted, the consumption amount of black toner is generally larger than the consumption amount of other color toners. Therefore, the cartridge containing black toner should be made larger than the other cartridges. There is.

  However, when only the cartridge for storing the toner of a specific color is enlarged as described above, the electrophotographic image forming apparatus may be enlarged or the space may be wasted.

JP 2006-184901 A JP 2003-316105 A

  SUMMARY OF THE INVENTION An object of the present invention is that an electrophotographic image forming apparatus provided with a support member on which a plurality of cartridges can be mounted can store a larger amount of a specific color toner than other color toners, and wastes space. An object of the present invention is to provide an electrophotographic image forming apparatus that suppresses the above.

  The present invention employs the following means in order to solve the above problems.

That is, the present invention includes an apparatus main body having an exposure unit for forming a latent image on an electrophotographic photosensitive member, a first cartridge for storing first color toner, and a second cartridge for storing second color toner. An electrophotographic image forming apparatus comprising: a support member that removably supports a plurality of cartridges and is movable between an inner position located inside the apparatus main body and an outer position located outside the apparatus main body. The first cartridge is supported by the support member at a position downstream of the plurality of cartridges in the pull-out direction in which the support member is pulled out from the inner position to the outer position. A protrusion that protrudes more than the second cartridge with respect to the detaching direction of the plurality of cartridges with respect to the member and can store the toner of the first color. The exposure unit and the second cartridge when viewed in the disengagement direction with the plurality of cartridges supported by the support member and the support member positioned at the inner position. Has an overlapping portion, and when viewed in the pull-out direction, the exposure unit and the protruding storage portion have an overlapping portion.

  As described above, according to the present invention, a larger amount of the first color toner can be accommodated than the other color toners, and the waste of space can be suppressed.

1 is a schematic cross-sectional view of an electrophotographic image forming apparatus according to an embodiment. FIG. 3 is a schematic cross-sectional view of a process cartridge according to the present embodiment. 1 is a perspective view of a process cartridge according to the present embodiment. 1 is a schematic cross-sectional view of an electrophotographic image forming apparatus according to an embodiment. The process cartridge attachment / detachment explanatory view according to the present embodiment. 1 is a schematic cross-sectional view of an electrophotographic image forming apparatus according to an embodiment. 1 is a schematic cross-sectional view of an electrophotographic image forming apparatus according to an embodiment. The figure which shows the drawing-out state of the supporting member which concerns on a present Example. 1 is a perspective view of an electrophotographic image forming apparatus according to an embodiment.

  DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments for carrying out the present invention will be exemplarily described in detail with reference to the drawings. However, the dimensions, materials, shapes, relative arrangements, and the like of the components described in this embodiment are not intended to limit the scope of the present invention only to those unless otherwise specified. .

(Example)
An electrophotographic image forming apparatus according to an embodiment of the present invention (hereinafter, appropriately referred to as “image forming apparatus”) will be described with reference to FIGS. In the following description, the “apparatus main body” refers to a cartridge tray (hereinafter referred to as “tray” as appropriate) 13 as a support member and a plurality of removably supported trays 13 in the image forming apparatus. The process cartridge 50 is excluded.

  Further, in the following description and drawings, symbols such as “50y, 50m, 50c, 50k” with suffixes y, m, c, k added to numbers are used as appropriate. These subscripts y, m, c, and k mean yellow, magenta, cyan, and black (black), respectively. In the image forming process sections of the respective colors basically having the same configuration, the members having the same function are denoted by the same reference numerals with subscripts corresponding to the respective colors. In the following description, the subscripts are omitted as appropriate.

<Overall configuration of electrophotographic image forming apparatus>
An overall configuration of an image forming apparatus capable of forming an image on the recording material P will be described. This image forming apparatus is an inline system in which a plurality of process cartridges 50 are arranged in a line. FIG. 1 shows a state in which process cartridges (hereinafter referred to as “cartridges”) 50 of the respective colors are mounted on the apparatus main body 100. Here, the first color (black) toner kT is stored in the cartridge 50k as the first cartridge. The other cartridges 50y, 50m, and 50c as second cartridges that store toner of the second color (colors other than black) include yellow toner yT, magenta toner mT, and cyan toner, respectively. cT is stored.

In the apparatus main body 100, a laser beam 11 based on an image signal is emitted from each of the electrophotographic photosensitive drums (hereinafter referred to as “photosensitive drums”) 30y, 30m, 30c, and 30k from a laser scanner 10 as an exposure unit. Irradiate the surface. Thereby, electrostatic latent images corresponding to the respective colors are formed on the respective photosensitive drums 30. These electrostatic latent images are respectively developed by the developing roller 42, and a toner image is formed on the surface of the photosensitive drum 30. The toner images of the respective colors formed on the respective photosensitive drums 30 are transferred to the recording material P conveyed by the recording material conveying belt 19 by applying a voltage to the transfer rollers 18y, 18m, 18c, and 18k. . The recording material P is fed to the recording material conveyance belt 19 after being fed by the feeding roller 1. In the process of being conveyed by the recording material conveying belt 19, toner images are sequentially transferred in the order of black (black), cyan, magenta, and yellow. As a result, the toner images of the respective colors are superimposed on the recording material P.

  Thereafter, the recording material P is conveyed to a fixing device 6 including a driving roller and a fixing roller having a built-in heater. Here, the fixing device 6 is provided on the left side of the tray 13 in FIG. Then, the recording material P is heated and pressed by the fixing device 6, whereby the toner image transferred onto the recording material P is fixed to the recording material P. Thereafter, the recording material P on which the toner image is fixed is discharged to the discharge tray 9 by the discharge roller pair 7.

<Overall configuration of process cartridge>
The process cartridge 50 according to the present embodiment will be described in more detail with reference to FIGS. The process cartridge is a cartridge in which a charging unit, a developing unit, an electrophotographic photosensitive member, and the like are integrally formed, and is configured to be detachable from the main body of the electrophotographic image forming apparatus.

  As described above, the toners yT, mT, cT, and kT having different colors are stored in the cartridges 50y, 50m, 50c, and 50k, respectively. The cartridge 50k has the same configuration as the other cartridges 50y, 50m, and 50c except that the type (color) of the stored toner and the toner storage portion have a larger capacity than the other. Therefore, in the following description, the internal structure of the cartridge will be described using cartridges 50y, 50m, and 50c that are second cartridges. The details of the cartridge 50k, which is the first cartridge in which black toner is stored, will be described later.

  The cartridge 50 includes a photosensitive drum 30 and a process unit as a toner image forming unit that acts on the photosensitive drum 30. Here, as the process means, there are a charging means 32, a developing roller 42, and a cleaning means 33. In addition, the cartridge 50 includes a toner storage portion 49 and a waste toner storage portion 35.

  The charging unit 32 uniformly charges the surface of the photosensitive drum 30. The developing roller 42 develops the latent image formed on the surface of the photosensitive drum 30 with toner. The toner storage unit 49 stores toner T for developing the latent image. The cleaning unit 33 is a toner removing unit for cleaning residual toner remaining on the surface of the photosensitive drum 30. The waste toner storage unit 35 stores the residual toner.

  The cartridge 50 includes a first unit 31 as a photosensitive unit and a second unit 41 as a developing unit.

<Configuration of first unit (photosensitive unit)>
The first unit 31 will be described. As shown in FIG. 2, the first unit 31 includes a photosensitive drum 30, a charging unit 32, a cleaning unit 33, a drum frame 34, and a waste toner storage unit 35.

  As shown in FIG. 3, one end side in the longitudinal direction of the photosensitive drum 30 is rotatably supported by the cover member 36 (the same applies to the developing roller 42). On the other hand, the other end side in the longitudinal direction of the photosensitive drum 30 is rotatably supported by the cover member 37. These cover members 36 and 37 are fixed to the drum frame 34 at both ends in the longitudinal direction of the drum frame 34.

  A coupling member 30 a for transmitting a driving force to the photosensitive drum 30 is provided on one end side in the longitudinal direction of the photosensitive drum 30. The coupling member 30a engages with the first main body coupling member 105 when the cartridge 50 is mounted on the apparatus main body 100 (see FIG. 5). Then, when a driving force is transmitted to the coupling member 30a from a driving motor (not shown) provided in the apparatus main body 100, the photosensitive drum 30 rotates in the direction of the arrow u shown in FIGS. .

  The charging unit 32 is supported by the drum frame 34 so as to be driven and rotated while being in contact with the photosensitive drum 30. The cleaning unit 33 is supported by the drum frame 34 so as to come into contact with the peripheral surface of the photosensitive drum 30 with a predetermined pressure.

(Configuration of second unit (development unit))
The second unit 41 will be described. As shown in FIG. 2, the second unit 41 includes a developing roller 42, a developing blade 43, and a developing frame 48. The developing frame 48 includes a toner storage portion 49 that stores the toner T to be supplied to the developing roller 42. The developing blade 43 that restricts the toner layer thickness on the peripheral surface of the developing roller 42 is fixed to the developing frame 48. As shown in FIG. 3, in order to rotationally drive the developing roller 42, a coupling member 67 that is driven from the apparatus main body 100 is provided on one end side of the developing roller 42.

<Cartridge tray (support member)>
The cartridge tray 13 as a support member will be described in more detail. As shown in FIG. 5, the tray 13 is movable with respect to the apparatus main body 100 in the D1 direction (pressing direction) and the D2 direction (drawing direction). That is, the tray 13 is provided so that it can be pulled out and pushed into the apparatus main body 100. Further, the tray 13 is movable in a substantially horizontal direction in a state where the apparatus main body 100 is installed on a horizontal plane. Further, the tray 13 is movable between an inner position located inside the apparatus main body 100 and an outer position located outside the apparatus main body 100. Here, with respect to the inner position, the tray 13 is separated from the recording material transport belt 19 inside the apparatus main body 100 and an image forming position where the cartridge 50 is positioned at a position where image formation is possible. It is also possible to move between positions. 1 shows a case where the tray 13 is located at the image forming position, FIG. 4 shows a case where the tray 13 is located at a position away from the recording material transport belt 19, and FIG. 5 shows a case where the tray 13 is located at the outer position. Shows when to do. In this embodiment, the case where the tray 13 is located inside the apparatus main body 100 and is located at an image forming position, a position away from the recording material transport belt 19 and a position between them is collectively referred to as an inner position. . Further, the tray 13 has a mounting portion 13a to which a plurality of cartridges 50 can be mounted (see FIG. 5).

  With the tray 13 pulled out to the outer position shown in FIG. 5, each cartridge 50 is detachably mounted on the mounting portion 13a along the direction of arrow C in the drawing.

Each cartridge 50 enters (is pushed into) the apparatus main body 100 together with the tray 13 while being placed in the mounting portion 13a. At this time, as shown in FIG. 4, the cartridge 50 moves in a state where the recording material conveyance belt 19 provided below the cartridge 50 and the photosensitive drum 30 maintain a constant distance F. That is, the cartridge 50 moves along a direction parallel to the recording material conveyance surface of the recording material conveyance belt 19. As a result, the tray 13 moves to the inner position. Even when the tray 13 is pushed in all the way, the cartridge 50 is kept away from the recording material conveyance belt 19.

  Thereafter, when the door 12 is closed, the cartridge 50 is positioned with respect to the apparatus main body 100. That is, the tray 13 moves to the image forming position. As a result, an image can be formed by the cartridge 50.

  As described above, the plurality of cartridges 50 can be collectively moved into the apparatus main body 100 by the tray 13 and can be pulled out to the outside of the apparatus main body 100 collectively. Therefore, the operability of the user can be improved as compared with a type in which a plurality of cartridges are individually mounted in or removed from the apparatus main body.

  Next, the operation of the tray 13 will be described with reference to FIGS. In these drawings, the cartridge 50 is omitted to make the operation of the tray 13 easier to understand.

  The tray 13 is supported so that it can be pulled out with respect to the tray holding member 14. The tray holding member 14 is interlocked with the movement of the door 12 as an opening / closing member. The door 12 is provided so as to be rotatable within a certain range with respect to the apparatus main body 100 around the rotation center 12a. The door 12 is configured to be rotatable between a closed position for closing the opening 80 shown in FIG. 6 and an open position for opening the opening 80 shown in FIG. 7.

  When taking out the cartridge 50 attached to the apparatus main body 100, first, the door 12 is rotated from the closed position to the open position. As the door 12 rotates, the engagement portion 15 provided on the door 12 rotates clockwise in FIG. 6 about the rotation center 12a. As a result, as shown in FIG. 7, the engaging portion 15 moves from the lower end 14 c 2 to the upper end 14 c 1 in the elongated hole 14 c provided in the tray holding member 14. The engaging portion 15 pushes the upper end 14c1 of the elongated hole 14c upward, and pushes the tray holding member 14 upward. As the engaging portion 15 moves, the tray holding member 14 moves in a direction away from the recording material conveyance belt 19 (arrow y1 in FIG. 7). Then, as shown in FIG. 8, in a state where the photosensitive drum 30 is separated from the recording material transport belt 19, the tray 13 moves through the opening 80 in the direction of the arrow D2 in the drawing and is pulled out of the apparatus main body 100. It is. FIG. 9 shows a perspective view in that state.

  Next, a case where the cartridge 50 is mounted on the apparatus main body 100 will be described. As shown in FIG. 8, in a state where the door 12 is located at the open position, the tray 13 is moved in the direction of the arrow D1 so as to pass through the opening 80, and is pushed into (enters into) the apparatus main body 100. Thereafter, as shown in FIG. 6, the door 12 is rotated to the closed position. As the door 12 rotates, the engaging portion 15 provided on the door 12 rotates counterclockwise around the rotation center 12a. Thereby, as shown in FIG. 6, the engaging portion 15 moves from the upper end 14 c 1 to the lower end 14 c 2 in the elongated hole 14 c provided in the tray holding member 14. Then, the engaging portion 15 pushes the lower end 14c1 of the elongated hole 14c downward, and pushes down the tray holding member 14 downward. Along with this movement, the engaging portion 15 moves the tray holding member 14 in the direction approaching the recording material conveyance belt 19 (the direction of the arrow y2 in FIG. 6). As described above, the cartridge 50 is positioned on the apparatus main body 100. That is, the tray 13 is located at the image forming position. More specifically, the photosensitive drum 30 contacts the recording material conveyance belt 19.

(Attaching the process cartridge to the main unit)
The mounting operation of the cartridge 50 to the apparatus main body 100 will be described in more detail.

  As shown in FIG. 5, the cartridge 50 is mounted along the direction of arrow C in the figure on the mounting portion 13a of the tray 13 pulled out to the outside position. By moving the tray 13 in the arrow D1 direction with all the cartridges 50 mounted, all the cartridges 50 pass through the openings 80 and enter the apparatus main body 100. In this embodiment, the cartridge 50 enters the apparatus main body 100 along a direction substantially orthogonal to the axial direction of the rotation center of the photosensitive drum 30 and the developing roller 42.

  Here, in the pull-out direction of the tray 13 (the direction of arrow D2 in FIG. 5), the cartridge 50k storing the black toner kT is detachably mounted on the most downstream side. The other cartridges 50y, 50m, and 50c are detachably mounted on the upstream side of the cartridge 50k.

  Further, the cartridge 50k as the first cartridge is provided with a protruding storage portion 50k1 capable of storing black toner kT on the upper surface portion 48ak side of the developing device frame 48 (see FIG. 1). The protruding storage portion 50k1 constitutes a part of the toner storage portion in the cartridge 50k. Further, the protruding storage portion 50k1 protrudes in the upper part of FIG. 1 from the upper surface portions 48ay, 48am, 48ac of the developing frame bodies 48 of the other cartridges 50y, 50m, 50c in a state where all the cartridges 50 are mounted. ing. In the cartridges 50y, 50m, and 50c, the upper surface portions 48ay, 48am, and 48ac in each developing frame 48 and the upper surface portions 34ay, 34am, and 34ac in each drum frame 34 are configured to be on the same surface. Further, the upper surface portion 34aK of the drum frame 34 in the cartridge 50k is configured to be flush with the upper surface portions 34ay, 34am, 34ac of the drum frame 34 of the cartridges 50y, 50m, 50c. As described above, the protruding storage portion 50k1 protrudes more than the cartridges 50y, 50m, and 50c that are the second cartridges in the direction in which the cartridge 50 is detached from the tray 13 (the direction opposite to the arrow C in FIG. 5). Yes. Further, the protruding storage portion 50k1 protrudes from the upper surface portion 34aK of the drum frame 34 of the cartridge 50k in the detachment direction.

  Further, when the cartridge 50 is supported by the tray 13 and the tray 13 is located at the inner position, the laser scanner 10 and the cartridges 50y, 50m, and 50c overlap when viewed in the direction in which the cartridge 50 is detached from the tray 13. Have

  Further, the laser scanner 10 and the protruding storage portion 50k1 have a portion that overlaps when viewed in the direction in which the tray 13 is pulled out.

  As described above, the protruding storage portion 50k1 constitutes a part of the toner storage portion 49. This extends the life of the black cartridge 50k and reduces the replacement frequency. Further, by devising the arrangement configuration of the cartridge 50 and the laser scanner 10 as described above, it is possible to effectively utilize the space upstream of the protruding storage portion 50k1 in the pull-out direction of the tray 13. Accordingly, the space efficiency of the entire image forming apparatus can be improved.

As a method for increasing the black toner capacity as compared with the toner capacity of other colors, a method of expanding the size of the container of the developing frame 48 in the left-right direction (drawing direction) in FIG. 1 is also possible. However, according to the present embodiment, the distance between the photosensitive drum 30k and the photosensitive drum 30c can be reduced and the size of the apparatus main body 100 can be reduced as compared with the method of enlarging in the pull-out direction. Furthermore, according to the present embodiment, color misregistration (color registration misregistration) between images of a plurality of colors can be reduced as compared with the method of enlarging in the drawing direction, and high image quality can be obtained. This is because the intervals between the plurality of photosensitive drums 30 can be made equal.

  Further, in the present embodiment, the distance to pull out the tray 13 can be reduced as compared with the configuration in which the cartridge 50k is increased in the pull-out direction. Therefore, according to this embodiment, usability can be improved.

  As shown in FIG. 1, in this embodiment, the black cartridge 50k having a large toner capacity and a large weight is mounted on the most downstream side (outermost side) of the mounting portion 13a along the pulling direction. Accordingly, when the black cartridge 50k is replaced, when the tray 13 is pulled out, the cartridge 50k is first exposed to the outside.

  Therefore, there is no need to pull out the tray 13 from the apparatus main body 100 to the all-color replaceable position (position where all cartridges are exposed) shown in FIG. That is, since it is only necessary to pull out the tray 13 to a position where at least only the cartridge 50k can be replaced, it is easy to replace the black cartridge 50k with a relatively high replacement frequency. In the present embodiment, the case where the first color is black has been described. However, toner other than black may be used. However, it is more preferable that the first color is black because the above-described effects can be obtained.

  Here, in this embodiment, specific examples of the electrophotographic image forming apparatus include an electrophotographic copying machine, an electrophotographic printer (for example, a laser beam printer, an LED printer, etc.), a facsimile machine, and a word processor.

  In this embodiment, the case where the cartridge is a process cartridge has been described. However, the present invention can be applied to other cartridges as long as at least a toner storage portion (developer storage portion) is provided. That is, the present invention can be applied to cartridges other than the process cartridge of the present embodiment. For example, a toner cartridge that stores toner or a developing cartridge that uses only the second unit 41 of the present embodiment as a cartridge can be cited as an example.

  DESCRIPTION OF SYMBOLS 10 ... Laser scanner, 13 ... Tray, 30 ... Photosensitive drum, 50 ... Process cartridge, 50k1 ... Projection storage part, 100 ... Main body of apparatus

Claims (5)

An apparatus main body having an exposure unit for forming a latent image on the electrophotographic photosensitive member;
A plurality of cartridges including a first cartridge that stores toner of the first color and a second cartridge that stores toner of the second color are removably supported, and an inner position positioned inside the apparatus body and the apparatus body A support member movable between an outer position located on the outer side of
In an electrophotographic image forming apparatus comprising:
The first cartridge is
The support member is supported by the support member at the most downstream position among the plurality of cartridges in the pulling direction in which the support member is pulled out from the inner position to the outer position, and the plurality of cartridges are detached from the support member. A protruding storage portion that protrudes more than the second cartridge in the direction and that can store toner of the first color;
When the plurality of cartridges are supported by the support member and the support member is located at the inner position, the exposure unit and the second cartridge overlap when viewed in the detachment direction, The electrophotographic image forming apparatus, wherein the exposure unit and the protruding storage portion have a portion overlapping when viewed in the pull-out direction.   The electrophotographic image forming apparatus according to claim 1, wherein the protruding storage portion constitutes a part of a toner storage portion in the first cartridge. A plurality of transfer rollers for transferring a toner image formed on the electrophotographic photosensitive member onto a recording material;
3. The electrophotographic image forming apparatus according to claim 1, wherein the support member is positioned between the exposure unit and the plurality of transfer rollers in a state where the support member is positioned at the inner position. 4. . The first cartridge includes a photosensitive unit having the electrophotographic photosensitive member, a developing roller for developing the latent image, and a developing unit having the protruding storage portion.
In a state where the first cartridge is supported by the support member, the developing unit is positioned on the downstream side of the photoconductor unit in the drawing direction,
When the support member is located at the inner position, the photosensitive unit is positioned so as to overlap the exposure unit when viewed in the detachment direction, and the exposure unit is located more than the projecting storage portion in the pull-out direction. The electrophotographic image forming apparatus according to any one of claims 1 to 3, wherein the electrophotographic image forming apparatus is located upstream.   5. The electrophotographic image forming apparatus according to claim 1, wherein the first color toner is a black toner, and the second color toner is a toner of a color other than black. apparatus.

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