JP5181864B2 - Image forming apparatus - Google Patents

Description

  The present invention relates to an image forming apparatus applied to a recording apparatus, a display apparatus, and the like to which an electrophotographic system such as a copying machine, a FAX, and a printer is applied.

  In an electrophotographic image forming apparatus, an image carrier such as a photosensitive drum, a charging device for uniformly charging the image carrier, and a surface charge are converted into an electrostatic latent image for process execution. For exposing the electrostatic latent image to a visible image with a developer (hereinafter referred to as toner), and electrically transferring the visible image on the image carrier to a medium such as a recording material. A transfer device for mechanical transfer, a cleaning device for removing toner remaining in the transfer operation by the transfer device on the image carrier, and the visualized toner on the recording material by heat or pressure permanently. And a fixing device for fixing.

  Of these, the configuration including the image carrier, the charging device, the exposure device, the developing device, the transfer device, and the cleaning device is referred to as a “process unit”. There is no need, and an image forming apparatus using a process unit in which an image carrier, a charging device, a cleaning device, and a developing device are integrated is common.

  Each device in each process has been promoted to reduce the size and speed of the device, especially with the increase in full-color output, and further demanded longer life, higher reliability, higher image quality and lower price. Yes.

  As a developing device, generally, a so-called two-component developing method using a mixture of toner and carrier is mainstream, and it is possible to output an image for a long time by continuously supplying the toner.

  However, such a two-component development method has a problem that the carrier deteriorates with time.

  Therefore, in recent years, mainly from the viewpoint of prolonging the service life and reliability, it has deteriorated over time by replenishing carrier materials in addition to toner and discharging excess carrier materials in a timely manner. An increasing number of image forming apparatuses are equipped with a “trickle-type” developing device that can suppress deterioration by replacing a carrier material with a certain probability.

  As described above, the two-component development method can achieve a long life and high reliability by adopting the “trickle method”. However, at present, technical countermeasures do not progress so much, and therefore, it is not possible to expect a long life for the image carrier, the charging device, and the cleaning device.

  Accordingly, when the image carrier, the charging device, and the cleaning device are integrated as a drum cartridge and the trickle method is adopted, the time required for replacement can be reduced by integrating the drum cartridge and the developing device. Since the lifespan of the drum cartridge and the developing device is different, it is wasteful of resources to replace both of them together. For this reason, it is necessary to separate the drum cartridge and the developing device from each other. That is, when the drum cartridge and the developing device are configured separately, it is desirable that the drum cartridge and the developing device can be easily replaced.

  For this reason, conventionally, for example, a technique has been proposed in which a process unit with a short lifetime is arranged at a position where it can be replaced with priority (see, for example, Patent Document 1).

Further, a technique has been proposed in which the drum cartridge and the developing device are taken out of the apparatus in an integrated state and can be easily separated outside the apparatus (for example, see Patent Document 2).
JP-A-5-289428 JP 2003-114601 A

  However, in the technique of Patent Document 1, a process unit having a long life cannot be easily replaced.

  In the technique disclosed in Patent Document 2, when the drum cartridge and the developing device are taken out and separated, a working space for that purpose must be secured, and the separation between the two is simple only outside the machine. If the configuration is such that the drum cartridge and the developing device are separated and dropped during the replacement work outside the apparatus, they may be damaged.

  The present invention has been made in view of the above circumstances, and an object thereof is to provide an image forming apparatus in which a developing device and a drum cartridge attached via a tray can be individually replaced by a simple operation.

  The above problem is solved by the following means.

[1] a drum cartridge;
A developing device;
A tray arranged to be drawable with respect to the main body of the apparatus,
First attachment means for attaching one of the drum cartridge and the developing device to the tray;
Second mounting means for mounting the other of the drum cartridge and the developing device to the tray,
The first attachment means includes
An engagement piece provided on the tray, the engagement piece being switchable between an engagement position engaging with the one and a non-engagement position where the engagement is released;
The engaging piece is
When the one is attached to the tray and the other is attached to the tray, the one is automatically removed from the non-engagement position to the engagement position, thereby removing the one from the tray. It is configured to be locked to prevent,
An image configured to release the locked state by automatically moving from the engagement position to the non-engagement position when the other is removed from the tray. Forming equipment.

[ 2 ] The image forming apparatus according to [1], wherein the second attachment unit is configured to be attached to the tray via the one by attaching the other to the one.

  According to the invention described in [1], the first attachment means for attaching one of the drum cartridge and the developing device to the tray prevents the one from being removed from the tray when the other is attached to the tray. Since it is in a state, it is possible to remove only the other from the tray while securely holding one on the tray.

Further, since the other is with the be removed from the tray, more be moved to the disengaged position from the engaging piece is automatically engaged position, one of the locked state is automatically released, the other After removing from the tray, one can be quickly removed from the tray without requiring a special unlocking operation.

Furthermore, the other with the be attached to the tray, for more to move from the engaging piece is automatically disengaged position to the engaged position, one becomes automatically locked, the tray above It is possible to easily and reliably prevent a situation in which one side is inadvertently removed from the tray without requiring a special locking operation in order to bring the attached side into a locked state.

According to the invention described in the preceding paragraph [2], since the other is attached to the tray via one,
The drum cartridge and the developing device are directly coupled to each other, so that the positional relationship between the two can be maintained properly, which contributes to stable image formation.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

  FIG. 1 is a schematic cross-sectional view showing a full-color electrophotographic image forming apparatus, and FIG. 2 is a schematic cross-sectional view showing a process unit used in the image forming apparatus.

  1 and 2, an image forming apparatus 20 includes an image carrier 1 such as a photosensitive drum, a charging device 2 for uniformly charging the surface of the image carrier 1 to form a potential, and a charging device. 2 to irradiate light to form a predetermined electrostatic latent image on the surface of the image carrier 1 charged to a desired potential by 2 and toner in the area where the electrostatic latent image is formed. A plurality of developing devices 4 for applying a mirror image by applying an electric field or the like are provided, and the powder on the image carrier 1 that has been mirrored is sequentially transferred onto a so-called transfer belt 5 called an intermediate transfer member. A primary transfer device 6 for moving by an electric field / pressure, a secondary transfer device 7 for moving powder on the transfer belt 5 onto a recording medium 11 such as recording paper by an electric field / pressure, and a recording medium 11 The powder that has moved up is permanently fixed by heat or pressure. And a because of the fixing device 8.

  On the other hand, in the primary transfer device 6, the powder may not completely move on the transfer belt 5 and may remain slightly on the image carrier 1. At this time, the residual powder remaining on the image carrier 1 is electrically and mechanically removed from the image carrier 1 by the cleaning device 9, and then the image carrier 1 is applied to the image carrier 1 by the slow current device 12. The charging process is performed again.

  In addition, since the mirror image formed on the transfer belt 5 cannot be completely transferred onto the recording medium in the secondary transfer device 7, it remains as a slight residual powder on the transfer belt 5. In some cases, this is electrically and mechanically removed by the transfer belt cleaning device 10.

  In order to form a color image, for example, a plurality of image forming units for each color such as yellow (Y), magenta (M), cyan (C), and black (K) are used and arranged as shown in FIG. In some cases, one image forming apparatus unit may be provided alone to form only a monochrome image.

  FIG. 3 is an external perspective view showing a process unit unit including the drum cartridge 21 and the developing device 30, and FIG. 4 is a cross-sectional view showing the process unit unit.

  3 and 4, the process unit section includes a tray 34, a drum cartridge 21 including the image carrier 1 accommodated via the tray 34, a developing device 30 including the developing device 4, and the drum cartridge 21. And a tray 34 to which the developing device 40 is attached.

  In this embodiment, the drum cartridge 21 is configured as a unit including the image carrier 1, the charging device (FIGS. 1 and 2), and the concept of the drum cartridge 21 in the present invention is at least an image. What is necessary is just to provide the support body 1. FIG.

  In this embodiment, the developing device 30 includes the developing device 4 having the developing roller 31, a toner supply unit (not shown), and the like. However, the concept of the developing device in the present invention is at least the developing roller 31. As long as it has.

  On the inner surface of the side wall of the apparatus main body 20A in the image forming apparatus 20, a movable member 200 that is movable in the front-rear direction (arrow a direction) with respect to the apparatus main body 20A is held. As shown in FIG. 4, a tray sliding rail 201 having a substantially U-shaped cross section is fixed to the inner surface of the movable member 200 along the longitudinal direction (front-rear direction).

  A slider rail 341 that is fitted to the rail 201 is fixed to the outer surface of the side wall of the tray 34, and the tray 34 is set to be movable in the front-rear direction along the rail 201 via the slider rail 341. Yes. Thereby, the tray 34 can be pulled out from the apparatus main body 20A.

  In addition, the image forming apparatus 20 includes a first attachment unit that attaches one of the drum cartridge 21 and the developing device 30 to the tray 34, and a second attachment unit that attaches the other drum cartridge 21 to the tray 34. And.

  In this embodiment, the first attachment means is an upward lifting restriction that restricts lifting of the developing device 30 above the tray 34 on one side of the developing device 30, and on the left side of the image forming device 20 in this embodiment. On the opposite side to the developing device 30, in this embodiment, on the right side, a removal prevention locking portion 40 that restricts lifting of the developing device 30 from the tray 34 and can be released is provided.

  The upward lifting restricting portion 50 restricts the left side of the developing device 30 from being lifted upward. For example, an inverted L-shaped fixing member fixed to the apparatus main body 20A side (specifically, the movable member 200). 32 and a protruding member 33 provided on the lower surface side of the developing device 30.

  As shown in FIGS. 4 and 5, the inverted L-shaped fixing member 32 protrudes rightward so as to face the upper surface of the left end portion of the developing device 30, and interferes with the upper surface of the developing device 30. Thus, the upward lifting of the developing device 30 is restricted.

  When the developing device 30 is attached to the tray 34 as shown in FIG. 3, the protruding member 33 enters the lower side of the slider rail 341 of the tray 34 and interferes with the slider rail 341 from the lower side. The lifting of the developing device is restricted.

  In this embodiment, the detachment prevention lock portion 40 restricts the right side of the developing device 30 from being lifted upward, and can be switched between an engaged state and an engaged state with respect to the developing device 30. A piece 401 is provided.

  The engaging piece 401 is disposed on the inner surface side of the bottom wall of the tray 34, and as shown in FIGS. 4 and 5, the prone posture (FIG. 5) engages with the recess 300 formed on the right side wall of the developing device 30. 4) and an upright posture (FIG. 5) that is disengaged.

  The engagement piece 401 is biased by a spring or the like (not shown) so as to be in the standing posture (FIG. 5) in which the engagement with the developing device 30 is released.

  Then, only when the drum cartridge 21 is set with the developing device 30 set on the tray 34, the engaging piece 401 is pushed by the drum cartridge 21 and changes to the prone posture. The right side of the developing device 30 is restricted by engaging with the concave portion 300.

  The second attachment means attaches the drum cartridge 21 to the tray 34. In this embodiment, the second attachment means is configured as a joint 60 that attaches the drum cartridge 21 to the developing device 30 attached to the tray 34 first. The drum cartridge 21 is attached to the tray 34 via the developing device 30.

  In this embodiment, the joint portion 60 has a pair of front and rear lever members 62 and 62 disposed at both ends in the longitudinal direction (front-rear direction) of the drum cartridge 21.

  As shown in FIG. 3, the lever members 62 and 62 are pivotally supported by a pivot 61 provided in the drum cartridge 21 so that the lever members 62 and 62 can swing in the left-right direction. Key-shaped engaging portions 62a and 62a are formed which enter the lower side of the developing roller shaft 301 and engage in a holding state.

  A spring force is applied to the pair of lever members 62 and 62 in a direction to engage with the developing roller shaft 30 by a spring (not shown).

  Each upper end portion 22 of the pair of lever members 62 and 62 is a release operation portion that releases the locking state of the locking portions 62a and 62a by pushing rightward in FIG. 4 against the spring force. Thus, the engagement state of the drum cartridge 21 with respect to the developing device 30 is released by releasing the locking state of the locking portions 62a and 62a.

  Next, a procedure for attaching and detaching the drum cartridge 21 and the developing device 30 will be described.

  When the drum cartridge 21 or the developing device 30 is attached to the tray 34, first, the tray 34 is pulled out from the apparatus main body 20A side.

  Then, as shown in FIG. 6, the developing device 30 is lowered to the left, and the developing device 30 is inserted from the left side toward the predetermined position of the tray 34. As a result, the protruding member 33 of the developing device 30 enters the lower side of the slider rail 341, and the upper left surface of the developing device 30 is accommodated below the inverted L-shaped fixing member 32 on the apparatus main body 20A side, and the upward lifting restriction is performed. Lifting the left side of the developing device 30 upward by the unit 50 is restricted.

  At this time, the engagement piece 401 of the removal preventing lock portion 40 is in a standing posture as shown in FIG. 5, and the right side of the developing device is not restricted from being lifted upward. Therefore, in this state, the developing device 30 can be easily detached from the tray 34 without performing a special unlocking operation or the like.

  When the developing device 30 is set on the tray 34 and the drum cartridge 21 is mounted thereon, the hook-shaped locking pieces 62a of the pair of front and rear lever members 62 and 62 at the joint 60 are shown in FIG. As described above, the drum cartridge 21 is joined to the developing device 30 by entering and engaging the lower side of the developing roller shaft 301. As a result, the drum cartridge 21 is attached to the tray 34 via the developing device 30.

  When the drum cartridge 21 is thus attached to the developing device 30, the engagement piece 401 in the removal prevention lock portion 40 is changed from the standing posture of FIG. 5 to the prone posture of FIG. 4 by being pushed against the lower surface of the drum cartridge 21. And enters the recess 300 of the developing device 30. As a result, the developing device 30 is held in a locked state that prevents it from being removed from the tray 34.

  On the other hand, when exchanging the drum cartridge 21 and the developing device 30, the tray 34 stored on the apparatus main body 20 side is pulled out.

  When the upper end portions 22 of the pair of lever members 62 and 62 in the joint portion 60 are pushed in, the hook-shaped locking pieces 62 a at the lower end portions of the lever members 62 and 62 are detached from the developing roller shaft 301. Therefore, the joined state between the drum cartridge 21 and the developing device 30 is released.

  Thereby, first, the drum cartridge 2 can be lifted upward and removed from the tray 3.

  When the drum cartridge 2 is removed from the tray 34 in this way, the engagement piece 401 is automatically changed from the prone state of FIG. 4 to the standing state shown in FIG. For this reason, the developing device 30 can lift the right side, which is disengaged from the engagement piece 401, to change to a take-out posture as shown in FIG. If the rightward movement is performed while rotating and changing so as to avoid the tip end portion 32 a of the fixing member 32, the protruding member 33 can be removed from the lower side of the slider rail 341 and easily removed from the tray 34.

  Thus, according to this embodiment, when the developing device 30 is set on the tray 34 and then the drum cartridge 21 is set on the developing device 30, the developing device 30 and the drum cartridge 21 are joined, and the tray 34. Can be formed in the apparatus main body 20A.

  In particular, when the drum cartridge 21 is attached to the tray 34 by the first attachment means 40 and 50 for attaching the developing device 30 to the tray 34, the developing device 34 is locked to prevent the developing device 34 from being removed from the tray 34. Only the drum cartridge 21 can be removed from the tray 34 while the developing device 30 is securely fastened to the tray 34.

  Further, when the drum cartridge 21 is removed from the tray 34, the locked state of the developing device 30 with respect to the tray 34 is automatically released. Therefore, after the drum cartridge 21 is removed from the tray 34, a special unlocking operation is required. The developing device 30 can be quickly removed from the tray 34.

  In addition, since the developing device 30 is automatically locked with respect to the tray 34 when the drum cartridge 21 is attached to the tray 34, a special device is required to place the developing device 30 previously attached to the tray 34 into a locked state. A situation in which the developing device 30 is inadvertently removed from the tray 34 can be easily and reliably prevented without requiring a locking operation.

  Further, since the drum cartridge 21 is attached to the tray 34 via the developing device 30 via one side, the drum cartridge 21 and the developing device 30 are directly coupled to each other, and the positional relationship between the both 21 and 30 can be maintained properly. This can contribute to stable image formation.

  In the above-described embodiment, the configuration in which the developing device 30 is first attached to the tray 34 and then the drum cartridge 21 is attached has been described. However, the present invention is directed to the developing device 30 and the drum on the tray 34. The mounting order of the cartridges 21 may be reversed. That is, the drum cartridge 21 may be attached by the first attachment means, and the developing device 30 may be attached by the second attachment means.

  In the above-described embodiment, the first attachment means includes the upper lifting restricting portion 50 that prevents the left side of the developing device 30 from being lifted and the removal prevention lock portion 40 that prevents the right side from being lifted. In the state where the drum cartridge 21 and the other of the developing device 30 (drum cartridge 21) are attached to the tray 34, the means is configured to be in a locked state that prevents the one (developing device 30) from being removed from the tray 34. If it is what is done, it is not restricted to the said structure.

  However, even in this case, the first attachment means automatically releases the locked state of the one (developing device 30) to the tray 34 when the other (drum cartridge 21) is removed from the tray 34. Preferably, the other (drum cartridge 21) is attached to the tray 34, so that one (developing device 30) is automatically locked with respect to the tray 34. It is desirable.

  In addition, the specific configurations of the take-out prevention lock portion 40 and the upward lifting restricting portion 50 are not limited to the configurations of the above-described embodiments, and can be arbitrarily changed.

  Further, the second mounting means is configured to mount the drum cartridge 21 on the tray 34 via the developing device 30 by mounting the drum cartridge 21 to the developing device 30, but the drum cartridge (the other of the two). 21 may be directly attached to the tray 34.

  Also, the specific configuration of the second mounting means has been described in the example realized by the joint portion 60 using the pair of lever members 62, 62 having the engagement piece 62a. It is also possible to join them together.

1 is a schematic cross-sectional view showing a full-color electrophotographic image forming apparatus according to an embodiment of the present invention. 2 is a schematic cross-sectional view showing a process unit in the image forming apparatus. FIG. FIG. 2 is an external perspective view illustrating a process unit unit including a drum cartridge and a developing device in the image forming apparatus. It is a cross-sectional view showing a state in which a drum cartridge is joined to the developing device. It is a cross-sectional view showing a state in which the drum cartridge is removed from the developing device. FIG. 10 is a perspective view showing a state in which the posture is changed in order to remove the developing device from the tray.

Explanation of symbols

DESCRIPTION OF SYMBOLS 20 ... Image forming apparatus 20A ... Apparatus main body 21 ... Drum cartridge (the other)
30 ... Developing device (one side)
34 ... Tray 40 ... Removal prevention locking part (first mounting means)
50 ... Up-lifting restricting portion (first mounting means)
60 ... Joining means (second mounting means)

Claims (2)

A drum cartridge,
A developing device;
A tray arranged to be drawable with respect to the main body of the apparatus,
First attachment means for attaching one of the drum cartridge and the developing device to the tray;
Second mounting means for mounting the other of the drum cartridge and the developing device to the tray,
The first attachment means includes
An engagement piece provided on the tray, the engagement piece being switchable between an engagement position engaging with the one and a non-engagement position where the engagement is released;
The engaging piece is
When the one is attached to the tray and the other is attached to the tray, the one is automatically removed from the non-engagement position to the engagement position, thereby removing the one from the tray. Configured to be locked to prevent
An image configured to release the locked state by automatically moving from the engagement position to the non-engagement position when the other is removed from the tray. Forming equipment. The image forming apparatus according to claim 1, wherein the second attachment unit is configured to be attached to the tray via the one by attaching the other to the one.

Images