JP6772030B2 - Process cartridge and image forming equipment - Google Patents

Description

The present invention relates to an image forming apparatus to which a process cartridge can be attached and detached.

In the process cartridge type image forming apparatus, there is a configuration in which the photosensitive drum is arranged below the intermediate transfer body, that is, the photosensitive drum, the developer carrier, and the developer layer thickness regulating member are arranged above the process cartridge. In this process cartridge, a scattering developer for preventing the developer that falls or scatters from the photosensitive drum, the developer carrier, and the developer regulating member falls or scatters into the image forming apparatus. There is a configuration in which a housing portion is provided (Patent Document 1).

Japanese Unexamined Patent Publication No. 2008-209914

The above-mentioned conventional configuration is provided with a regulating portion for preventing the developer from falling due to an impact during the process cartridge attachment / detachment operation by the user. However, when the user handles the used process cartridge in various postures, the developer contained in the regulatory section may leak to the outside of the process cartridge.

Therefore, an object of the present invention is to provide a process cartridge in which the developer does not leak to the outside as much as possible even if the handling posture changes.

In order to solve the above problems, the process cartridge of the present invention is used.
A process cartridge that can be attached to and detached from the main body of the image forming device.
A developer carrier that supports a developer and a developer
A developer regulating member that regulates the amount of the developer carried by the developer carrier, and a developer regulating member.
A first frame body having a side wall formed with an opening for supporting the axial end portion of the developer carrier and exposing the axial end portion of the developer regulating member.
A second frame body attached to the side wall so as to cover the opening and having a collecting portion for collecting the developing agent leaking from the opening.
With
In order to guide the developer leaking from the opening from the opening to the collecting portion, a regulating portion having a surface extending from the edge of the opening of the second frame toward the collecting portion is provided. It is characterized by being prepared.
Further, in order to solve the above problems, the image forming apparatus of the present invention is used.
With the device body
With the above process cartridge
It is characterized by having.

As described above, according to the present invention, the photosensitive drum, the developing agent carrier, and the developing agent scattered and dropped from the regulating member of the developing agent contained in the regulating portion in the process cartridge are handled by the user in the process cartridge. It is possible to minimize leakage to the outside of the.

Schematic sectional view of the length of the developer collecting portion and the developing agent regulating portion according to Example 1. Schematic sectional view of the image forming apparatus and the process cartridge according to the first embodiment. Schematic perspective view of the image forming apparatus and the process cartridge according to the first embodiment. Schematic sectional view of the process cartridge according to the first embodiment. Schematic perspective view of the developing unit according to the first embodiment Schematic perspective view of the photoconductor unit according to the first embodiment Schematic cross-sectional view showing a developer collecting part and a developing agent controlling part according to Example 1.

Hereinafter, embodiments for carrying out the present invention will be described in detail exemplarily based on examples with reference to the drawings. However, the dimensions, materials, shapes of the components described in this embodiment, their relative arrangements, and the like should be appropriately changed depending on the configuration of the apparatus to which the invention is applied and various conditions. That is, it is not intended to limit the scope of the present invention to the following examples.

(Example 1)
Here, the image forming apparatus is an image forming apparatus for forming an image on a recording material (recording medium) by using an electrophotographic image forming method. Examples of the image forming apparatus include a copier, a printer (laser beam printer, LED printer, etc.), a facsimile apparatus, a word processor, and a multifunction printer (multifunction printer) thereof.

(Configuration of image forming apparatus)
The overall configuration of an embodiment of the image forming apparatus according to the present invention will be described with reference to FIGS. 2 and 3. FIG. 2 is a schematic cross-sectional view of the image forming apparatus 100 of this embodiment. FIG. 3 is a perspective view in which the process cartridge 7 is mounted on the main body of the image forming apparatus 100. The image forming apparatus 100 uses the first, second, and third image forming units for forming images of each color of yellow (Y), magenta (M), cyan (C), and black (K), respectively. , Has a fourth image forming unit SY, SM, SC, SK. Then, a part of the image forming unit S (SY, SM, SC, SK) of the image forming apparatus 100 is configured as a process cartridge 7 (7Y, 7M, 7C, 7K), respectively, and is configured to be replaceable. In this embodiment, the configurations and operations of the first to fourth image forming portions are substantially the same except that the colors of the formed images are different. Therefore, when no distinction is required below, Y, M, C, and K will be omitted and a general description will be given.

The overall configuration of the process cartridge 7 mounted on the image forming apparatus 100 of this embodiment will be described with reference to FIGS. 4 to 6. FIG. 4 is a schematic cross-sectional view of the process cartridge 7. FIG. 5 is a schematic perspective view of the developing unit. FIG. 6 is a schematic perspective view of the photoconductor unit. In each process cartridge 7, a photoconductor unit 13 having a photosensitive drum 1 (1Y, 1M, 1C, 1K) as an image carrier and a developing roller 17 as a developer carrier are brought into contact with the photosensitive drum 1. It is composed of a development unit 4 for contact development. The process cartridge 7 is formed into a cartridge by rotatably integrating the developing unit 4 with the photoconductor unit 13.
As shown in FIG. 4, the developing unit 4 has a developing frame body 18 as a first frame body that supports various elements in the developing unit 4. The developing unit 4 is provided with a developing roller 17 that comes into contact with the photosensitive drum 1 and rotates in the direction of arrow D (counterclockwise) shown in FIG. The developing roller 17 is rotatably supported via the developing roller bearing member 32 at both ends in the developing roller axial direction (hereinafter, longitudinal direction) (FIG. 5). In this embodiment, the developing bearing member 32 is provided, but the supporting portion of the developing roller 17 may be formed integrally with the developing frame body 18. Further, the developing unit 4 develops with a developing agent storage chamber (hereinafter, toner storage chamber) 18a in which toner T as a developing agent is stored, a developing chamber 18b in which a developing roller 17 is arranged, and a toner storage chamber 18a. It has an opening 18c that communicates with the chamber 18b. In this embodiment, the developing chamber 18b is located above the toner storage chamber 18a. Further, in this embodiment, the developing unit 4 uses a non-magnetic one-component developer, that is, toner T (TY, TM, TC, TK) as the developing agent.

In the developing chamber 18b, a toner supply roller 20 as a developing agent supplying member that comes into contact with the developing roller 17 and rotates in the direction of arrow E (clockwise), and a developer for regulating a toner layer on the surface of the developing roller 17. A developing blade 21 as a regulating member is arranged. Further, the toner storage chamber 18a of the developing frame 18 is provided with a stirring member 23 for stirring the stored toner T and for conveying the toner to the toner supply roller 20 through the opening 18c. .. The stirring member 23 has a rotating shaft 23a parallel to the rotating shaft direction of the developing roller 17, and a stirring sheet 23b which is a flexible sheet-like member having one end attached to the rotating shaft 23a and agitating and transporting toner.

The photoconductor unit 13 has a cleaning frame 14 as a second frame that supports various elements in the photoconductor unit 13. A photosensitive drum 1 is rotatably attached to the cleaning frame 14 via a drum bearing member 40 (FIG. 6) in the direction of arrow A (clockwise) shown in FIG. In this embodiment, the drum bearing member 40 is provided as a separate body from the cleaning frame body 14, but may be integrally formed with the cleaning frame body 14 as a support portion of the photosensitive drum 1 in the cleaning frame body 14. Further, a charging roller 2, which is a charging means for uniformly charging the surface of the photosensitive drum 1, is rotatably attached to the cleaning frame 14 via a charging roller bearing 15. The charging roller 2 is rotatably supported by a charging roller bearing 15 slidably assembled with respect to the cleaning frame 14. The charging roller 2 is urged in the direction of arrow F shown in FIG. 4 toward the photosensitive drum 1 by urging the charging roller bearing 15 by the charging roller pressurizing spring 16 as an urging means. Further, the cleaning frame 14 is attached with a cleaning blade 6 in which an elastic member 6a that comes into contact with the surface of the photosensitive drum 1 and a support member 6b for supporting the elastic member are integrally formed. Then, a space serving as a removal developer accommodating portion (waste toner accommodating portion) 14a (14aY, 14aM, 14aC, 14aK) is formed by the cleaning blade 6 and the cleaning frame body 14.
Then, the image forming apparatus 100 is mounted around the photosensitive drums 1 (1Y, 1M, 1C, 1K) as the four image carriers by mounting the process cartridges 7 (7Y, 7M, 7C, 7K). The charging roller 2 and the scanner unit (exposure device) 3 are arranged in the. Here, the scanner unit 3 is an exposure means that irradiates a laser based on image information to form an electrostatic image (electrostatic latent image) on the photosensitive drum 1. A developing device (hereinafter referred to as a developing unit) 4 (4Y, 4M, 4C, 4K) and a cleaning blade 6 (6Y, 6M, 6C, 6K) as a cleaning means are arranged around the photosensitive drum 1. .. Further, an intermediate transfer belt 5 as an intermediate transfer body for transferring the toner image on the photosensitive drum 1 to the recording material 12 is arranged so as to face the four photosensitive drums 1.

The process cartridge 7 forms an image along the axial direction of the photosensitive drum 1 as shown by an arrow G in FIG. 3 via mounting means such as a mounting guide and a positioning member (not shown) provided in the image forming apparatus 100. It is removable from the device 100. Here, the arrow G indicates a direction in which the process cartridge 7 is inserted into the image forming apparatus 100. The process cartridges 7 for each color all have the same shape. In the process cartridge 7 for each color, toners T (TY, TM, TC, TK) of each color of yellow (TY), magenta (TM), cyan (TC), and black (TK) are stored. The intermediate transfer belt 5 abuts on all the photosensitive drums 1, rotates in the direction of arrow B in the drawing, and is hung on a plurality of support members (driving roller 26, secondary transfer opposing roller 27, driven roller 28). The B direction is a direction from the upstream to the downstream of the intermediate transfer belt 5. Further, on the inner peripheral surface side of the intermediate transfer belt 5, four primary transfer rollers 8 (8Y, 8M, 8C, 8K) as primary transfer means are arranged side by side so as to face each photosensitive drum 1. ing. Further, a secondary transfer roller 9 as a secondary transfer means is arranged at a position facing the secondary transfer facing roller 27 on the outer peripheral surface side of the intermediate transfer belt 5.

(Image formation process)
At the time of image formation, first, the surface of the photosensitive drum 1 is uniformly charged by the charging roller 2. Next, the surface of the charged photosensitive drum 1 is scanned and exposed by the laser beam L corresponding to the image information emitted from the scanner unit 3, and an electrostatic latent image according to the image information is formed on the photosensitive drum 1. Next, the electrostatic latent image formed on the photosensitive drum 1 is developed as a toner image (developer image) by the developing unit 4. The toner image formed on the photosensitive drum 1 is transferred (primary transfer) onto the intermediate transfer belt 5 by the action of the primary transfer roller 8. For example, when forming a full-color image, the above processes are sequentially performed in the first to fourth image forming units SY, SM, SC, and SK, and the toner images of each color are sequentially superimposed on the intermediate transfer belt 5. Is primarily transferred. After that, the recording material 12 is conveyed to the secondary transfer unit in synchronization with the movement of the intermediate transfer belt 5. Then, the four-color toner images on the intermediate transfer belt 5 are collectively secondarily transferred onto the recording material 12 by the action of the secondary transfer roller 9 that is in contact with the intermediate transfer belt 5 via the recording material 12. Toner.

The recording material 12 on which the toner image is transferred is conveyed to the fixing device 10 as a fixing means. By applying heat and pressure to the recording material 12 in the fixing device 10, the toner image is fixed to the recording material 12. The primary transfer residual toner remaining on the photosensitive drum 1 after the primary transfer step is removed by the elastic member 6a of the cleaning blade 6 and drops in the direction of gravity, and is inside the waste toner accommodating portion 14a (14aY, 14aM, 14aC, 14aK). Is housed in. Further, the secondary transfer residual toner remaining on the intermediate transfer belt 5 after the secondary transfer step is removed by the intermediate transfer belt cleaning device 11. The removed transfer residual toner (waste toner) is discharged to a waste toner box (not shown) of the image forming apparatus 100. The image forming apparatus 100 in the present invention is also capable of forming a monochromatic or multicolor image using only the desired single or some (but not all) image forming portions.

(Toner retention configuration on the developing blade)
Next, a configuration for restricting the drop of the developer will be described with reference to FIGS. 1, 4, and 5. FIG. 1 is a cross-sectional view taken along the line JJ of FIG. 4, and is a schematic longitudinal sectional view showing a developer regulating member and a developer collecting portion described later. As shown in FIG. 1, the developing blade 21 has a blade portion 21b that regulates the layer thickness of toner on the developing roller 17 at one end, and a supporting portion 21a that supports the blade portion 21b. In the present embodiment, both the blade portion 21b and the support portion 21a are made of a thin metal plate, and are welded and joined by laser irradiation. The support portion 21a is screwed and assembled to the developing frame body 18 with a screw 43 in a state where a notch is formed and is positioned by engaging with a boss 42 protruding from the developing frame body 18. Then, in the present embodiment, as shown in FIG. 4, in the developing blade 21, one end that regulates the layer thickness of the toner on the developing roller 17 is in contact with the developing blade 21 and the photoconductor drum 1 in an opposed region (nip). It is configured to be located below the gravity direction of the part). Therefore, after the layer thickness is regulated by the developing blade 21, the toner that has separated from the developing roller 17 before reaching the nip portion where the developing blade 21 and the photoconductor drum 1 abut is on the developing blade 21. It will be deposited. Therefore, a regulating member 31 is attached to the developing unit 4 in order to hold the toner deposited on the developing blade 21 so as not to fall and to prevent the toner from leaking to the outside of the cartridge 7. Specifically, the regulating member 31 is made of a flexible sheet member, and one end thereof is fixed to the support portion 21a of the developing blade 21 with double-sided tape or the like on the short side orthogonal to the longitudinal direction of the regulating member 31. The end is in contact with the surface layer of the photosensitive drum 1. On the other hand, the regulating member 31 is provided apart from the developing roller 17 in the longitudinal direction of the developing roller 17 (see FIG. 5). In this way, the space S surrounded by the developing roller 17, the developing blade 21, the photosensitive drum 1, and the regulating member 31 is formed.

With this configuration, even if the developer that falls and scatters from the exposed portion of the developing roller 17 or the contact portion between the developing roller 17 and the developing blade 21 tilts the process cartridge 7 around the axis, it goes out of the process cartridge 7. It is possible to regulate falling and scattering. In particular, in the developing unit 4 and the process cartridge 7 in which the developing roller 17 is located above the scanner unit 3 in the direction of gravity as shown in FIG. 2, the developing agent that falls and scatters from the developing roller 17 and the developing blade 21 is the scanner unit 3. Need to be prevented from contaminating. In this case, the contact position of the regulating member 31 with respect to the photosensitive drum 1 is the drum rotation of the contact position H of the photosensitive drum 1 with the charging roller 2 and the position B latently imaged on the photosensitive drum 1 by the scanner unit 3. It is on the downstream side in the direction. Further, the contact position between the photosensitive drum 1 and the regulating member 31 is on the upstream side in the drum rotation direction with respect to the nip portion (contact position C) with the developing roller 17.

(Structure of developer collecting part and regulating part)
Next, a configuration for collecting the leaked developer will be described with reference to FIGS. 1, 4, 5, 6, and 7. FIG. 7 is a cross-sectional view taken along the line KK of FIG. 1, which is a schematic cross-sectional view showing a developer collecting portion and a second regulating portion as viewed from the bearing member side of the photosensitive drum 1. As described above, the developer is regulated in the space S formed by the developing roller 17, the developing blade 21, the photosensitive drum 1 and the regulating member 31 on the cross section of the process cartridge 7 shown in FIG. Further, in the state of being mounted on the image forming apparatus 100, the regulated developer is accumulated in the space S formed by the developing roller 17, the developing blade 21, the photosensitive drum 1 and the regulating member 31 as shown in FIG. It tends to be easy.

On the other hand, the image forming apparatus 100 is required to be miniaturized. Therefore, the size of the developing frame 18 is reduced. On the other hand, in addition to the length of the developing blade 21 that abuts on the developing roller 17, a notch that engages with the boss 42 protruding from the developing frame 18 and a screw 43 for fixing to the developing frame 18 are provided. You need a minute length. That is, the support portion 21a of the developing blade 21 needs to have a length that abuts on the developing roller 17 and a length that is provided with the notch / screw 43, and the longitudinal end portion can be grasped at the time of assembly. It is difficult to shorten the length in the longitudinal direction. Therefore, as shown in FIG. 5, an opening is provided in the developing frame 18, and the longitudinal end portion of the supporting portion 21a of the developing blade 21 is exposed from the opening. That is, at the end in the longitudinal direction, the support portion 21a of the developing blade 21 is exposed from the developing blade opening 18h of the developing frame body 18. Therefore, there is a concern that the developer accumulated in the space S may leak when the developing blade opening 18h is lowered.

In this embodiment, the side wall 14b of the cleaning frame 14 and the developer collecting portion 41 are provided on the longitudinal outer side of the developing blade opening 18h of the developing frame 18. As shown in FIGS. 1 and 6, the developer collecting portion 41 is provided on the drum bearing member 40, has an opening on the developing blade 21 side, and has surfaces 41a, 41b, 41c, 41d, 41e around the opening. It is a collection space surrounded by, and can accommodate the developer. Further, in the longitudinal direction of the developing frame, a wall having a surface for guiding the developer leaking to the developing agent collecting portion 41 between the developing agent collecting portion 41 and the developing blade opening 18h is formed in the developing blade opening 18h. It is provided as a regulation unit 18k around it. Then, as shown in FIG. 5, the restricting portion 18k constitutes a wall portion with surfaces 18k2, 18k3, 18k4 surrounding the longitudinal end portion 21a of the developing blade 21 exposed from the developing blade opening 18h. The cleaning frame body 14, the developing frame body 18, and the drum bearing member 40 are resin molded bodies. The regulating unit 18k has a role of guiding the developer leaking from the developing blade opening 18h to the developing agent collecting unit 41. If there is no wall portion having the above-mentioned surface, there is a concern that the developing agent may leak from the joint portion between the developing frame body 18 and the drum bearing member 40. The above-mentioned surfaces 18k2, 18k3, and 18k4 extend from the edge of the developing blade opening 18h to the developing agent collecting portion 41, and the surface 18k4 facing the surface 18k3 is the length of the developing blade 21 as compared with the 18k3. The amount of protrusion in the direction is small. Further, the surface 18k2 is also provided with a portion where the amount of protrusion in the longitudinal direction of the developing blade 21 is small. It is assumed that the portion where the protrusion amount is reduced is located below the developing blade opening 18h in the process (in the middle) of changing the posture of the process cartridge so that the developing blade opening 18h is downward. It is provided in the area. Therefore, when the user tilts the process cartridge so that the developing blade opening 18h is downward, the developing agent collects the developing agent 41 from the surface 18k4 and the surface 18k2, which are the above-mentioned regions where the amount of protrusion is small. It is configured to make it easier to go to. Then, as shown in FIG. 7, when the developing unit 4 is in contact with the photosensitive drum 1, a part of the surfaces 18k2 and 18k3 facing the developing blade 21 of the regulating portion 18k is inside the developing agent collecting portion 41. It is in.

That is, the regulating portion 18k is located between the developing blade opening 18h and the developing agent collecting portion 41, and the amount of protrusion of the developing blade 21 such as the surface 18k4 and the surface 18k2 of the regulating portion 18k in the longitudinal direction is small. By these two points, the developer accumulated in the space S is guided by the surfaces 18k2 and 18k3 of the second regulating member 18k, and the developer is more reliably transmitted to the developer collecting portion 41 along the region where the protrusion amount is small. It is configured to be accommodated. That is, the surfaces 18k2, 18k3, and 18k4 prevent the developer from leaking from between the developing frame 18 and the drum bearing member 40, and the developing agent is housed in the developing agent collecting unit 41. There is. In this embodiment, the regulation portion 18k is not provided with a surface above the opening 18h. However, a regulating portion 18k having a surface serving as a wall is provided so as to surround the entire circumference of the developing blade opening 18h, and a region where the amount of protrusion in the longitudinal direction of the developing blade 21 is small is formed at a position where the developer is to be guided. , The developer may be induced there. Further, the same effect can be obtained even if the developing unit 4 moves in a direction away from the photosensitive drum 1. Further, as shown in FIG. 5, the developing blade opening 18h covers the entire circumference of the longitudinal end portion 21a of the developing blade 21. As a result, the developer accumulated in the space S can be more reliably moved to the second developer regulating section. The developing blade opening 18h, the regulating portion 18k, and the developing agent collecting portion 41 in the present invention may be either only one side or both sides of the end portion in the longitudinal direction of the developing blade 21. As described above, when the user handles the used process cartridge, the amount of the developer leaking to the outside of the process cartridge can be minimized.

1 ... Photosensitive drum, 7 ... Process cartridge, 17 ... Development roller, 18 ... Development frame, 18h ... Development blade opening, 18k ... Regulatory part, 21 ... Development blade, 31 ... Regulatory member, 40 ... Drum bearing member, 41 … Developer collection section

Claims (9)

A process cartridge that can be attached to and detached from the main body of the image forming device.
A developer carrier that supports a developer and a developer
A developer regulating member that regulates the amount of the developer carried by the developer carrier, and a developer regulating member.
A first frame body having a side wall formed with an opening for supporting the axial end portion of the developer carrier and exposing the axial end portion of the developer regulating member.
A second frame body attached to the side wall so as to cover the opening and having a collecting portion for collecting the developing agent leaking from the opening.
With
In order to guide the developer leaking from the opening from the opening to the collecting portion, a regulating portion having a surface extending from the edge of the opening of the second frame toward the collecting portion is provided. A process cartridge characterized by being equipped. In the region between the side walls provided on both sides of the developer carrier in the axial direction, a regulating member for holding the developer dropped from the developer carrier on the developer regulating member is further provided. The process cartridge according to claim 1. An image carrier that carries a developer image developed by the developer carried by the developer carrier is further provided.
The restricting member is a flexible sheet member that is attached to the first frame below the region where the developer carrier and the image carrier face each other and is in contact with the surface of the image carrier. The process cartridge according to claim 2, wherein the process cartridge is provided. The process cartridge according to claim 3, wherein the second frame is a bearing member that supports an axial end of the image carrier. The process cartridge according to any one of claims 1 to 4, wherein the regulating portion is a wall portion provided around the opening. The wall portion protrudes so that the surface reaches the collecting space of the developer in the collecting portion, and at least the opening portion is changed in the process of changing the posture of the process cartridge so that the opening portion is downward. The process cartridge according to claim 5, wherein the protruding amount is partially reduced in a region below the surface. Any of claims 1 to 6, wherein the regulating portion is provided so as to restrict the developing agent leaking from the opening from moving to the joint portion between the first frame body and the second frame body. The process cartridge according to item 1. The process cartridge according to any one of claims 1 to 7, wherein the first frame body and the second frame body are resin molded bodies. With the device body
The process cartridge according to any one of claims 1 to 8.
An image forming apparatus comprising.

Images