JP2018031827A - Developing device, process cartridge, and image forming apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a developing device which can reduce blowout of toner cloud while simplifying assembly and reducing the size thereof, a process cartridge, and an image forming apparatus.SOLUTION: A developing device comprises: a developing housing which can store a developer therein; a developer holding body which is supported by the developing housing and rotates while holding the developer on an external surface; a first cover member which covers a top face of the developing housing; a second cover member which forms an exhaust passage exhausting air from the inside of the developing housing to the outside of the developing housing with an inner wall surface of the first cover member along the external surface of the developer holding body; and a filter member which is arranged at an exhaust port of the exhaust passage while sandwiched by the first cover member and the second cover member, and inhibits passage of the developer and permits passage of the air.SELECTED DRAWING: Figure 8

Description

  The present invention relates to a developing device, a process cartridge, and an image forming apparatus.

  A developer carrier that carries the developer on the surface, moves the surface, and supplies the developer to the latent image on the surface of the latent image carrier in the development area facing the latent image carrier, and a developer carrier Development in which a developer accommodating portion for accommodating a developer to be supplied is formed, a gas in the developer accommodating portion is discharged to the outside of the apparatus, and a pressure relief opening portion that suppresses an increase in air pressure in the developer accommodating portion is formed. A developing device comprising: a container; and a filter member that is provided in the pressure relief opening and that suppresses the discharge of the developer from the pressure relief opening, wherein the filter member is a porous film made of a fluororesin. An apparatus is known (Patent Document 1).

  A developer carrying member for carrying the developer on the surface, supplying the developer to the latent image on the surface of the latent image carrying member in a developing region that moves to the surface and opposes the latent image carrying member; and a developer carrying member The developer in the developer container that contains the developer to be supplied to the developer is supplied to the developer conveying member by rotating, and the gas in the developer container is discharged to the outside of the apparatus. In a developing device, comprising: a depressurization opening that suppresses an increase in atmospheric pressure; and a filter member that is provided in the depressurization opening and suppresses discharge of the developer from the depressurization opening. There is also known a developing device including a developer movement path shielding member that blocks a movement path of the developer splashed up by the rotation of the member toward the filter member (Patent Document 2).

Japanese Patent Laying-Open No. 2015-004773 JP 2014-178661 A

  SUMMARY OF THE INVENTION An object of the present invention is to provide a developing device, a process cartridge, and an image forming apparatus capable of facilitating assembly and suppressing toner cloud ejection while reducing the size.

In order to solve the above problem, the developing device according to claim 1,
A development housing capable of accommodating the developer therein;
A developer holder that is supported by the developer housing and rotates while holding the developer on an outer surface;
A first cover member covering an upper surface of the developing housing;
A second cover member that forms a discharge path for discharging air from the inside of the developing housing to the outside of the developing housing between the inner surface of the first cover member along the outer surface of the developer holder; ,
A filter member arranged to be sandwiched between the first cover member and the second cover member at a discharge port of the discharge path and preventing the passage of the developer and allowing the air to pass therethrough,
It is characterized by that.

According to a second aspect of the present invention, in the developing device according to the first aspect,
On the inner wall surface of the first cover member or the second cover member, a convex portion extending in the length direction along the rotation axis of the developer holder of the filter member is formed, and the second cover member is formed. A cover member is engaged with and engaged with the first cover member, and the convex portion presses the filter member in the thickness direction;
It is characterized by that.

According to a third aspect of the present invention, in the developing device according to the first or second aspect,
The second cover member is disposed on a side facing the developer holding body,
It is characterized by that.

According to a fourth aspect of the present invention, in the developing device according to any one of the first to third aspects,
The filter member is provided at a position not facing the developer holder;
It is characterized by that.

In order to solve the above-mentioned problem, a process cartridge according to claim 5,
It is attached to and detached from the image forming apparatus main body,
An image carrier on which an electrostatic latent image is formed on the surface;
The developing device according to claim 1, wherein a toner is supplied to the electrostatic latent image formed on a surface of the image carrier to develop the electrostatic latent image.
It is characterized by that.

In order to solve the above problem, an image forming apparatus according to claim 6,
An image carrier on which an electrostatic latent image is formed on the surface;
The developing device according to claim 1, wherein a toner is supplied to the electrostatic latent image formed on a surface of the image carrier to develop the electrostatic latent image.
It is characterized by that.

According to the first, fifth, and sixth aspects of the invention, it is possible to facilitate the assembly of the developing device and to suppress the ejection of the toner cloud while reducing the size.
According to the second aspect of the present invention, the assembly of the developing device can be facilitated.
According to the third aspect of the present invention, the assembly of the developing device can be facilitated and the size can be reduced.
According to the fourth aspect of the present invention, clogging by the developer in the discharge path can be suppressed.

1 is a schematic cross-sectional view showing an internal configuration of an image forming apparatus. (A) is a perspective view which shows a process cartridge, (b) is a longitudinal cross-sectional schematic diagram of a process cartridge. It is a cross-sectional schematic diagram showing the movement of the developer in the developing device. It is a perspective view which shows a 2nd cover member and a filter member. (A) is a perspective view which shows the inner wall surface side of a 1st cover member, (b) is a partial expansion perspective view which shows the attachment part of the 2nd cover member which expands and shows the B section in (a). It is a perspective view showing attachment of the 2nd cover member to the 1st cover member. (A) is a top view which shows the inner surface side of the 1st cover member by which the 2nd cover member was snap-fitted, (b), (c) is the 2nd cover member 4 snap-fit to the 1st cover member. It is a fragmentary sectional view of the longitudinal direction which shows the state made. (A) is a front view of the 1st cover member by which the 2nd cover member was snap-fitted, (b) crossed the longitudinal direction which shows the state by which the 2nd cover member was snap-fitted to the 1st cover member. It is a fragmentary sectional view of the direction to do.

Next, the present invention will be described in more detail with reference to the drawings with reference to embodiments and specific examples. However, the present invention is not limited to these embodiments and specific examples.
Also, in the description using the following drawings, it should be noted that the drawings are schematic and the ratio of each dimension and the like are different from the actual ones, and are necessary for the description for easy understanding. Illustrations other than the members are omitted as appropriate.
In order to facilitate understanding of the following description, in the drawings, the front-rear direction is the X-axis direction, the left-right direction is the Y-axis direction, and the up-down direction is the Z-axis direction.

(1) Overall Configuration and Operation of Image Forming Apparatus FIG. 1 is a schematic cross-sectional view showing the internal configuration of the image forming apparatus 1 according to this embodiment.
Hereinafter, the overall configuration and operation of the image forming apparatus 1 will be described with reference to the drawings.

  The image forming apparatus 1 includes a control device 10, a paper feeding device 20, a photosensitive unit 30, a developing device 40, a transfer device 50, a fixing device 60, and a power supply device 70. On the upper surface (Z direction) of the image forming apparatus 1, a discharge tray 1a for discharging and storing a sheet on which an image is recorded is formed.

  The control device 10 includes an image forming device control unit 11 that controls the operation of the image forming device 1, a controller unit 12 that prepares image data corresponding to a print processing request, an exposure control unit 13 that controls lighting of the exposure head LH, and the like. Have

  The controller unit 12 converts print information input from an external information transmission device (for example, a personal computer) into image information for forming a latent image, and outputs a drive signal to the exposure head LH at a preset timing. . The exposure head LH of the present embodiment is configured by an LED head in which a plurality of light emitting elements (LEDs) are linearly arranged along the main scanning direction.

  A paper feeding device 20 is provided at the bottom of the image forming apparatus 1. The sheet feeding device 20 includes a sheet stacking plate 21, and a plurality of sheets P as recording media are stacked on the upper surface of the sheet stacking plate 21. The sheets P stacked on the sheet stacking plate 21 and positioned in the width direction by a regulating plate (not shown) are pulled out one by one from the upper side by the sheet pulling portion 22 (X direction), and then the registration roller pair. 23 is conveyed to the nip portion.

  The photoconductor unit 30 includes a photoconductor drum 31 that is provided in parallel above the paper feeding device 20 (in the Z direction) and serves as an image carrier that is rotationally driven. A charging roller 32, an exposure head LH, a developing device 40, a primary transfer roller 52, and a cleaning blade 34 are arranged along the rotation direction of the photosensitive drum 31. A cleaning roller 33 for cleaning the surface of the charging roller 32 is disposed opposite to and in contact with the charging roller 32.

The developing device 40 includes a developing housing 41 in which a developer composed of toner and a carrier is accommodated. In the developing housing 41, a developing roller 42 as a developer holding member disposed facing the photosensitive drum 31, and the developer is stirred and conveyed to the developing roller 42 side obliquely below the back side of the developing roller 42. A pair of transfer augers 44 and 45 are disposed. A layer regulating member 46 that regulates the layer thickness of the developer is disposed in proximity to the developing roller 42.
Each of the developing devices 40 is configured in a similar manner except for the developer contained in the developing housing 41, and each forms a yellow (Y), magenta (M), cyan (C), and black (K) toner image. .

  The surface of the rotating photosensitive drum 31 is charged by the charging roller 32, and an electrostatic latent image is formed by the latent image forming light emitted from the exposure head LH. The electrostatic latent image formed on the photosensitive drum 31 is developed as a toner image by the developing roller 42.

  The transfer device 50 includes an intermediate transfer belt 51 to which each color toner image formed on the photoconductive drum 31 of each photoconductor unit 30 is transferred, and each color toner image formed on each photoconductor unit 30 to the intermediate transfer belt. 51, a primary transfer roller 52 that sequentially transfers (primary transfer) to 51, and a secondary transfer roller 53 that collectively transfers (secondary transfer) each color toner image transferred on the intermediate transfer belt 51 onto the paper P. Yes.

  Each color toner image formed on the photoconductive drum 31 of each photoconductive unit 30 is transferred to an intermediate transfer belt 51 by a primary transfer roller 52 to which a predetermined transfer voltage is applied from a power supply device 70 controlled by the image forming apparatus control unit 11. The toner images are sequentially electrostatically transferred (primary transfer), and a superimposed toner image in which toners of respective colors are superimposed is formed.

  The superimposed toner image on the intermediate transfer belt 51 is conveyed to a region (secondary transfer portion T) where the secondary transfer roller 53 is disposed as the intermediate transfer belt 51 moves. When the superimposed toner image is conveyed to the secondary transfer unit T, the paper P is supplied from the paper feeding device 20 to the secondary transfer unit T in accordance with the timing. A predetermined transfer voltage is applied to the secondary transfer roller 53 from the power supply device 70 controlled by the image forming apparatus control unit 11, and the intermediate transfer medium P is fed from the registration roller pair 23 and guided by the conveyance guide. Multiple toner images on the transfer belt 51 are collectively transferred.

  Residual toner on the surface of the photosensitive drum 31 is removed by the cleaning blade 34 and collected in the waste developer container. The surface of the photosensitive drum 31 is recharged by the charging roller 32. Residues that cannot be completely removed by the cleaning blade 34 and adhere to the charging roller 32 are captured and accumulated on the surface of the cleaning roller 33 that rotates in contact with the charging roller 32.

  The fixing device 60 includes a heating module 61 and a pressure module 62, and a fixing nip portion N (fixing area) is formed by a pressure contact area between the heating module 61 and the pressure module 62.

The sheet P on which the toner image is transferred in the transfer device 50 is conveyed to the fixing device 60 via the conveyance guide in a state where the toner image is not fixed. The toner image is fixed on the paper P conveyed to the fixing device 60 by the action of heating and pressure bonding by a pair of heating module 61 and pressure module 62.
The sheet P on which the fixing toner image is formed is discharged from the discharge roller pair 69 to the discharge tray 1 a on the upper surface of the image forming apparatus 1 via the conveyance roller pair 68.

(2) Process Cartridge FIG. 2A is a perspective view showing the process cartridge 100, FIG. 2B is a schematic longitudinal sectional view of the process cartridge 100, and FIG. 3 is a schematic sectional view showing movement of the developer D in the developing device 40. is there.
Hereinafter, the configuration and operation of the process cartridge 100 will be described with reference to the drawings.

(2.1) Overall Configuration of Process Cartridge The process cartridge 100 is configured such that the photosensitive unit 30 and the developing device 40 are integrated, and is detachable from the image forming apparatus 1.

(2.2) Configuration of Photoreceptor Unit In the photoreceptor unit 30, a photoreceptor drum 31 is rotatably supported by a unit housing 35. In the unit housing 35, a charging roller 32, a cleaning roller 33, a cleaning blade 34, A neutralization bar 36 that equalizes the residual potential of the photosensitive drum 31 and a conveyance auger 37 that conveys the toner removed by the cleaning blade 34 to a waste toner collection container (not shown) are arranged.

(2.3) Configuration and Operation of Developing Device In the developing device 40, a developing roller 42 is rotatably supported by a developing housing 41, and conveyance augers 44 and 45 and a layer regulating member 46 are disposed in the developing housing 41. ing. The periphery of the transport augers 44 and 45 in the developing housing 41 is filled with the developer D and is closed by the first cover member 43A.

The first cover member 43A is made of a synthetic resin such as ABS, closes the storage area for the developer D, and maintains a gap G with the outer peripheral surface 42a of the developing roller 42, so that the photosensitive drum 31 of the developing roller 42 is covered. (See FIG. 3).
Further, the first cover member 43 is formed with a discharge path 47 for discharging air from the inside of the developing housing 41 to the outside of the developing housing 41.

As shown in FIG. 3, the developing roller 42 is disposed to face the outer peripheral surface of the photosensitive drum 31 through an opening 41 </ b> C formed in the developing housing 41. The developing roller 42 includes a cylindrical developing sleeve 42A that is rotatably supported with respect to the developing housing 41, and a cylindrical magnet member that is provided in the inner space of the developing sleeve 42A and is fixed to the developing housing 41. As a magnet 42B.
The developing sleeve 42A is configured such that the developer D is held on the outer peripheral surface 42a by the magnetic force of the magnet 42B, and the developer D is conveyed and supplied to the electrostatic latent image on the photosensitive drum 31 by the rotation of the developing sleeve 42A. .

  As shown in FIG. 3, the magnet 42B has magnetic poles formed in the order of S3, N2, S1, N1, and S2 along the rotation direction of the developing sleeve 42A, and the developer D pumped up by the S3 magnetic pole is layered. It is transported while being held by the N2 magnetic pole that is regulated by the regulating member 46 and that faces the layer regulating member 46.

  The S1 magnetic pole is disposed opposite to the photosensitive drum 31, and holds the developer D conveyed from the N2 magnetic pole by the rotation of the developing sleeve 42A. A developing bias voltage is applied from the power supply device 70 of the main body of the image forming apparatus 1 to form an electric field between the developing sleeve 42 </ b> A and the photosensitive drum 31, and the toner TN in the developer D is transferred to the photosensitive drum 31. The carrier in the developer D moves and is held by the S1 magnetic pole, and adhesion to the photosensitive drum 31 is suppressed.

The N1 magnetic pole is disposed above the developing roller 42 and holds the developer D conveyed from the S1 magnetic pole side by the rotation of the developing sleeve 42A.
The S2 magnetic pole is disposed above the transport auger 44, and the developer D transported from the N1 magnetic pole side is peeled from the developing sleeve 42A by the rotation of the developing sleeve 42A. Specifically, the developer on the developing sleeve 42A in which the magnetic force of the developing sleeve 42A is substantially zero due to the repulsive force of the magnetic fields directed to the S2 magnetic pole and the S3 magnetic pole that are the same polarity, and the toner is consumed in the development D is peeled off.

(2.4) Configuration and Action of Discharge Channel As shown in FIG. 3, the discharge channel 47 is formed by a second cover member 43B attached to face the inner wall surface of the first cover member 43A.
The discharge path 47 is developed by holding the developer D by the magnetic force of the developing roller 42 while the first cover member 43A holds a predetermined gap G through which the developer D conveyed by the developing roller 42 passes. An inlet 47A is provided in a region S (see FIG. 3) where the agent D is sealed.
The discharge port 47 </ b> B is provided at a position close to the photosensitive drum 31 above the developing roller 42. Therefore, clogging of the filter member 48 due to the developer D flowing into the filter member 48 is suppressed.

A filter member 48 is provided in the discharge port 47B. The material of the filter member 48 is not particularly limited, and polyolefin (PE, PP, etc.), polyamide, polyester (PET, etc.), aromatic polyamide, or a composite material thereof can be used.
By using a porous material having a collection efficiency of 25% (particle diameter of 0.3 to 0.5 μm) and a pressure loss of about 3 Pa at a pressure loss of 10 cm / second, the generated toner cloud is prevented from passing through. An increase in pressure can be suppressed.

(3) Formation of Discharge Path FIG. 4 is a perspective view showing the second cover member 43B and the filter member 48, FIG. 5 (a) is a perspective view showing the inner wall surface side of the first cover member 43A, and FIG. FIG. 6A is a partially enlarged perspective view showing an attachment portion of the second cover member 43B showing an enlarged B portion in FIG. 6A, and FIG. 6 is a perspective view showing attachment of the second cover member 43B to the first cover member 43A. 7A is a plan view showing the inner surface side of the first cover member 43A in which the second cover member 43B is snap-fitted, and FIGS. 7B and 7C show the second cover member 43A in the second state. FIG. 8A is a partial cross-sectional view in the longitudinal direction showing a state where the cover member 43B is snap-fitted, FIG. 8A is a front view of the first cover member 43A where the second cover member 43B is snap-fitted, and FIG. The first cover member 43A and the second cover member It is a fragmentary sectional view of the direction which cross | intersects the longitudinal direction which shows the state by which 43B was snap-fitted.
Hereinafter, the formation of the discharge passage 47 will be described with reference to the drawings.

As shown in FIG. 4, the second cover member 43 </ b> B is made of a synthetic resin such as ABS, and a plurality of air that passes through the filter member 48 is discharged in the longitudinal direction along the axial direction of the developing roller 42. The through hole 43Ba is formed, and the filter member 48 is fitted (see the arrow in FIG. 4).
On the longitudinal direction and both ends of the second cover member 43B, a plurality of snap-fit engagement claws 43Bb are provided, and a positioning boss 43Bc having a snap-fit engagement claw is erected at the center.

As shown in FIG. 5, the first cover member 43A has an engagement groove 43Aa to which the second cover member 43B into which the filter member 48 is fitted is engaged by a snap fit and attached. A plurality of positioning claws 43Ac corresponding to the positioning bosses 43Bc of the second cover member 43B are formed at the center.
A convex portion 43Ab extending in the longitudinal direction of the filter member 48 is formed on the inner wall surface of the first cover member 43A (illustrated by hatching in FIG. 5B).

  The positioning boss 43Bc of the second cover member 43B is fitted into the positioning hole 43Ac of the first cover member 43A configured as described above, and the filter member 48 is fitted into the engagement groove 43Aa of the first cover member 43A. The discharge path 47 is formed by snap-fit fastening the engaging claws 43Bb of the second cover member 43B (see arrows in FIG. 6).

As shown in FIGS. 7 and 8, when the second cover member 43B in which the filter member 48 is fitted to the first cover member 43A is attached by snap fit, the outer periphery of the filter member 48 is The first cover member 43 </ b> A is pressed by a convex portion 43 </ b> Ab formed on the inner wall surface of the cover member 43 </ b> A and is in close contact with the periphery of the through hole 43 </ b> Ba that discharges air passing through the filter member 48.
Therefore, the toner cloud can be prevented from leaking from the contact surface between the filter member 48 and the second cover member 43B.

Since the filter member 48 is held by being sandwiched and pressed between the first cover member 43A and the second cover member 43B in the thickness direction, the first cover member 43A is used with an adhesive, a double-sided tape, or the like. Or even if it is not bonded to the second cover member 43B, it can be stably held therebetween. Therefore, assembly can be facilitated while downsizing.
Alternatively, the filter member 48 may be fitted into the first cover member 43A, and the second cover member 43B having a convex portion on the inner wall surface may be attached to the first cover member 43A.

DESCRIPTION OF SYMBOLS 1 ... Image forming apparatus 10 ... Control apparatus 20 ... Paper feeding apparatus 30 ... Photoconductor unit 31 ... Photoconductor drum 35 ... Unit housing 40 ... Developing apparatus 41 ... Developing housing 42 ... Developing roller 43A ... first cover member 43Aa ... engaging groove 43Ab ... convex part 43B ... second cover member 43Ba ... through hole 43Bb ... Engagement claw 47 ... discharge path 48 ... filter member
100 ... Process cartridge

Claims (6)

A development housing capable of accommodating the developer therein;
A developer holder that is supported by the developer housing and rotates while holding the developer on an outer surface;
A first cover member covering an upper surface of the developing housing;
A second cover member that forms a discharge path for discharging air from the inside of the developing housing to the outside of the developing housing between the inner surface of the first cover member along the outer surface of the developer holder; ,
A filter member arranged to be sandwiched between the first cover member and the second cover member at a discharge port of the discharge path and preventing the passage of the developer and allowing the air to pass therethrough,
A developing device. On the inner wall surface of the first cover member or the second cover member, a convex portion extending in the length direction along the rotation axis of the developer holder of the filter member is formed, and the second cover member is formed. A cover member is engaged with and engaged with the first cover member, and the convex portion presses the filter member in the thickness direction;
The developing device according to claim 1. The second cover member is disposed on a side facing the developer holding body,
The developing device according to claim 1, wherein The filter member is provided at a position not facing the developer holder;
The developing device according to claim 1, wherein: It is attached to and detached from the image forming apparatus main body,
An image carrier on which an electrostatic latent image is formed on the surface;
The developing device according to claim 1, wherein a toner is supplied to the electrostatic latent image formed on a surface of the image carrier to develop the electrostatic latent image.
A process cartridge characterized by that. An image carrier on which an electrostatic latent image is formed on the surface;
The developing device according to claim 1, wherein a toner is supplied to the electrostatic latent image formed on a surface of the image carrier to develop the electrostatic latent image.
An image forming apparatus.

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