JP6685979B2 - Developing container, process cartridge and image forming apparatus - Google Patents

Description

  The present invention relates to a developing container that contains a developer used for forming an image on a recording medium. The present invention also relates to a process cartridge that forms a developer image on a photosensitive drum and is attachable to and detachable from the apparatus body of the image forming apparatus, and an image forming apparatus that forms an image on a recording medium using the developer. is there.

  In an image forming apparatus such as a printer using an electrophotographic image forming system (electrophotographic process), when a recording material is imaged, the photosensitive drum is first uniformly charged by a charging roller. Next, the charged photosensitive drum is selectively exposed by the exposure device to form an electrostatic latent image on the photosensitive drum. Further, the electrostatic latent image formed on the photosensitive drum is developed as a toner image using toner by the developing device. Then, the toner image formed on the photosensitive drum is transferred to a recording material such as recording paper or a plastic sheet, and the toner image transferred to the recording material is heated and pressed by the fixing device to be recorded on the recording material. Establish. In this way, an image is formed on the recording material. Further, the toner remaining on the photosensitive drum after the toner image is transferred to the recording material is removed by the cleaning blade.

  In such an image forming apparatus, the process means such as the photosensitive drum, the charging roller, and the developing device generally require maintenance. In recent years, in order to easily perform maintenance of these process means, a photosensitive drum, a charging roller, a developing device, and a cleaning blade are integrated into a cartridge. Generally, a cartridge having such a process means is called a process cartridge. This process cartridge is attachable to and detachable from the main body of the image forming apparatus. By exchanging the process cartridge, the process means can be exchanged and the process means can be maintained.

  Here, conventionally, there is known an in-line type image forming apparatus in which a plurality of photosensitive drums are arranged substantially horizontally and which transfers a toner image on the photosensitive drums to a recording material via an intermediate transfer belt. ing. Further, in such an image forming apparatus, there is an image forming apparatus in which a plurality of photosensitive drums, a developing device, and an exposing device are arranged below the intermediate transfer belt. When the photosensitive drum, the developing device, and the exposing device are arranged below the intermediate transfer belt, the photosensitive drum, the developing device, and the exposing device are located inside the image forming apparatus on the side opposite to the fixing device with respect to the intermediate transfer belt. Will be placed in. Therefore, the photosensitive drum, the developing device, and the exposure device can be arranged at positions apart from the fixing device. This can prevent the photosensitive drum, the developing device, and the exposure device from being affected by the heat from the fixing device.

  As described above, when the photosensitive drum, the intermediate transfer belt, and the exposure device are arranged below the intermediate transfer belt, generally, in the developing chamber in which the developing roller carrying the toner used for the development is arranged, It is arranged above the toner storage chamber in which it is stored. Further, the developing chamber and the toner storage chamber are communicated with each other through the opening. In such a developing device, the toner accommodated in the toner accommodating chamber needs to be conveyed to the developing chamber disposed above the toner accommodating chamber against the gravity through the opening.

Therefore, conventionally, a developing device (developing container) is provided with a sheet-shaped stirring member, and by rotating the stirring member, the stirring member splashes the toner accumulated at the bottom of the toner storage chamber into the developing chamber. Was raised. Specifically, the sheet-shaped stirring member rotates around a rotation center axis extending in a substantially horizontal direction to lift the toner accumulated at the bottom of the toner storage chamber. Further, when the stirring member lifts the toner, the stirring member abuts against the inner wall surface of the toner storage chamber and bends. When the contact state between the inner wall surface of the toner storage chamber and the stirring member is released, the stirring member restores its original shape, and the restoring force causes the toner on the stirring member to jump up against the gravity into the developing chamber. .

  Incidentally, the developing container is generally provided with a developing roller rotatably supported with respect to the frame of the developing container and a developing blade for adjusting the layer thickness of the toner carried on the developing roller. There is. Further, the developing container is provided with a sheet member that closes the gap between the frame and the developing roller so that the toner does not leak from the gap between the frame and the developing roller of the developing container. Further, in the developing container, a seal member for closing a gap between the developing roller and the frame body, a gap between the developing blade and the frame body, and a gap between the sheet member and the frame body is provided. It is provided near the end in the direction. This prevents the toner in the developing container from leaking out of the developing container. However, when the pressure in the developing container rises, a pressure difference occurs between the inside and outside of the developing container, resulting in a gap between the sheet member and the developing roller and a gap between the frame member of the developing container and the seal member. There is a risk that toner will leak from the.

  Here, in the technique disclosed in Patent Document 1, in the configuration in which the developing chamber is arranged below the toner storage chamber, an opening is provided in the inner wall of the developing chamber, and the opening has air permeability. Blocked by a filter. As a result, even when a shock is applied to the developing device, air is discharged from the opening and the pressure in the developing chamber is reduced, so that the toner can be prevented from leaking from the developing device.

  Further, in the technique disclosed in Patent Document 2, the developing device is not provided with a developing chamber, and the developing roller is arranged above the screw for conveying the toner in the toner storage chamber. Further, an opening is provided on the inner wall of the toner storage chamber, and the opening is closed by a filter having air permeability. Then, when an air flow is generated toward the opening, toner floating in the developing device is collected by the filter by the air flow generated by the rotation of the developing roller.

Japanese Patent No. 5571779 Japanese Patent No. 4790676

  Here, in the developing container in which the sheet-shaped stirring member supplies the toner into the developing chamber, the stirring member rotates to carry not only the toner but also the air into the developing chamber. Therefore, when the stirring member rotates, the pressure inside the developing chamber rises, and a pressure difference occurs between the inside and outside of the developing container, which causes a gap between the sheet member and the developing roller and a frame and a seal of the developing container. There is a risk that toner will leak from a gap between the member and the like.

  Further, in recent years, the image forming speed (printing speed) of the image forming apparatus has been increased, so that a large amount of toner needs to be supplied to the developing chamber. For that purpose, it is required to increase the rotational speed of the sheet-shaped stirring member and to increase the thickness of the stirring member. However, in such a case, since a large amount of air is carried into the developing chamber by the rotation of the stirring member, the pressure inside the developing chamber rises, which causes the gap between the sheet member and the developing roller, etc., as described above. There is a risk that toner will leak from the.

Therefore, an object of the present invention is to prevent the toner from leaking out from the developing chamber in the developing container in which the toner is conveyed from the toner storing chamber to the developing chamber by rotating the stirring member.

In order to achieve the above object, the developing container according to the present invention,
A developer carrying member for carrying a developer,
A transport member for transporting the developer,
A frame for storing the developer,
A developer storage chamber for storing the transport member,
A developing chamber in which the developer carrier is arranged,
A partition part for partitioning the developer accommodating chamber and the developing chamber, for communicating the developer accommodating chamber with the developing chamber, and passing the developer conveyed from the developer accommodating chamber to the developing chamber. A partition provided with a first opening,
A second opening that communicates the inside of the developing chamber with the outside of the frame in an orthogonal direction orthogonal to the direction of the rotation axis of the transport member;
With a frame,
A sealing member that suppresses the developer from leaking between the frame and the developer carrier,
A filter for allowing passage of air and restricting passage of a developer, the filter being fixed to the frame so as to cover the second opening,
Have,
By the deformation of the front Symbol conveying member is released such that said developer is conveyed to the developing chamber from said developer accommodating chamber via the first opening, the conveying member is constructed deformably It is characterized by

Further, in order to achieve the above object, the process cartridge according to the present invention,
The developing container described above,
An image carrier on which a developer image is formed,
Have
It is characterized in that it is detachable from the main body of the image forming apparatus.

Further, in order to achieve the above object, the image forming apparatus according to the present invention,
The developing container described above,
An image carrier on which a developer image is formed,
A fixing device for fixing the developer image on the recording medium;
It is characterized by having.

  The present invention can prevent toner from leaking out from the developing chamber in the developing container in which the toner is conveyed from the toner storing chamber to the developing chamber by rotating the stirring member.

Schematic cross-sectional view of a process cartridge according to an embodiment Schematic cross-sectional view of an image forming apparatus according to an embodiment FIG. 3 is a diagram showing a process cartridge being inserted into the main body of the image forming apparatus. 1 is a perspective view and a schematic sectional view of a developing unit according to an embodiment. FIG. 3 is a diagram showing a state where the toner in the toner storage chamber is conveyed to the developing chamber. 1 is a perspective view of a process cartridge according to an embodiment. Schematic cross-sectional view of a process cartridge according to an embodiment The figure explaining the example of arrangement | positioning of the deaeration opening and filter which concern on an Example.

(Example)
Embodiments of the present invention will be exemplified below with reference to the drawings. However, the dimensions, materials and shapes of the components described in the embodiments and their relative arrangements, etc., should be appropriately changed according to the configuration of the device to which the invention is applied and various conditions. The scope is not limited to the following embodiments.

<Electrophotographic image forming apparatus 100>
The overall configuration of the electrophotographic image forming apparatus 100 (image forming apparatus 100) according to this embodiment will be described with reference to FIGS. 2 and 3. FIG. 2 is a schematic diagram of the image forming apparatus 100 according to this embodiment. 3 is a perspective view showing a state in which the process cartridge 7 is attached to the image forming apparatus 100.

  The image forming apparatus 100 is a first to fourth image forming unit for forming images of yellow (Y), magenta (M), cyan (C), and black (K) as a plurality of image forming units. It has formation parts SY to SK. In this embodiment, the process cartridge 7 is detachable from the main body of the image forming apparatus 100.

  In this embodiment, the configurations and operations of the first to fourth image forming units are substantially the same except that the colors of the images to be formed are different. Therefore, in the following, the subscripts Y to K will be omitted and a general description will be given unless particularly distinguished. In this embodiment, the image forming apparatus 100 has four photosensitive drums 1 (1Y to 1K) as image bearing members. The photosensitive drum 1 rotates in the direction of arrow A in FIG. Around the photosensitive drum 1, a charging roller 2 (2Y to 2K) and a scanner unit 3 are arranged.

  Here, the charging roller 2 (see FIG. 1) is a charging unit that uniformly charges the surface of the photosensitive drum 1. The charging roller 2 is biased toward the photosensitive drum 1 in the direction of arrow C in FIG. The scanner unit 3 is an exposure unit that irradiates a laser based on image information to form an electrostatic latent image on the photosensitive drum 1 (corresponding to the image carrier). Around the photosensitive drum 1, a developing unit 4 (4Y to 4K) as a developing device and a cleaning blade 6 (see FIG. 1) as a cleaning unit are arranged. Here, the developing unit 4 has a developing roller 22 (see FIG. 1) as a developer carrying member carrying at least a developer.

  Further, an intermediate transfer belt 5 (intermediate transfer belt 5) for transferring a toner image (corresponding to a developer image) on the photosensitive drum 1 to a recording material 12 (corresponding to a recording medium) is provided facing the four photosensitive drums 1. Corresponding to the body) is arranged. Further, in this embodiment, the developing unit 4 uses toner T (TY to TK) which is a non-magnetic one-component developer. In this embodiment, the developing unit 4 brings the developing roller 22 into contact with the photosensitive drum 1 to perform contact development.

  Further, the photoconductor unit 13 includes a removed toner storage portion (see FIG. 1) that stores transfer residual toner (waste toner) remaining on the photosensitive drum 1, the photosensitive drum 1, the charging roller 2, and the cleaning blade 6. Have. Further, in this embodiment, the developing unit 4 and the photoconductor unit 13 are integrally made into a cartridge to form the process cartridge 7 (7Y to 7K). The process cartridge 7 is attachable to and detachable from the image forming apparatus 100 via a mounting means such as a mounting guide and a positioning member (not shown) provided in the image forming apparatus 100. Further, the process cartridge 7 has the photosensitive drum 1 carrying at least a developer image.

In this embodiment, the process cartridge 7 can be attached to the apparatus body of the image forming apparatus 100 in the direction of arrow G in FIG. 3, which is the direction of the rotation axis of the photosensitive drum 1. In this embodiment, the process cartridges 7 for each color have the same shape. However, the shape and size are not limited to this, and may be different. For example, it may be larger than other cartridges in order to increase the capacity of the black cartridge. Further, the process cartridge 7 for each color contains toner T (TY to TK) of each color of yellow (Y), magenta (M), cyan (C), and black (K). The intermediate transfer belt 5 is in contact with all the photosensitive drums 1 and moves in the direction of arrow B in FIG. The intermediate transfer belt 5 is spanned by a plurality of supporting members (a driving roller 29, a secondary transfer counter roller 30, and a driven roller 28). On the inner peripheral surface side of the intermediate transfer belt 5, four primary transfer rollers 8 (8Y to 8K) (corresponding to primary transfer members) are arranged in parallel so as to face the respective photosensitive drums 1. A secondary transfer roller 9 is arranged at a position facing the secondary transfer counter roller 30 on the outer peripheral surface side of the intermediate transfer belt 5.

<Image forming process>
When forming an image, first, the surface of the photosensitive drum 1 is uniformly charged by the charging roller 2. Next, the surface of the photosensitive drum 1 is scanned and exposed by the laser light emitted from the scanner unit 3 to form an electrostatic latent image on the photosensitive drum 1 based on image information. The electrostatic latent image formed on the photosensitive drum 1 is developed as a toner image by the developing unit 4. The toner image formed on the photosensitive drum 1 is primarily transferred onto the intermediate transfer belt 5 by the primary transfer roller 8.

  For example, when forming a full-color image, the above-described processes are sequentially performed in the image forming units SY to SK, which are the first to fourth image forming units, so that the toner images of the respective colors are sequentially superimposed on the intermediate transfer belt 5. To be done. Then, the recording material 12 is conveyed to the secondary transfer portion in synchronization with the movement of the intermediate transfer belt 5. Then, by the secondary transfer roller 9 (corresponding to the secondary transfer member) that is in contact with the intermediate transfer belt 5 via the recording material 12, the four-color toner images on the intermediate transfer belt 5 are collectively recorded. Secondary transcribed on.

  Then, the recording material 12 to which the toner image is transferred is conveyed to the fixing device 10. When the recording material 12 is heated and pressed in the fixing device 10, the toner image is fixed on the recording material 12. The primary transfer residual toner remaining on the photosensitive drum 1 after the primary transfer process is removed by the cleaning blade 6. 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 is also capable of forming a single-color or multi-color image by using a desired single image forming unit or some (not all) image forming units. In this embodiment, the developing unit 4 is arranged on the opposite side of the fixing device 10 with respect to the intermediate transfer belt 5.

<Process cartridge>
Next, the overall configuration of the process cartridge 7 installed in the image forming apparatus 100 according to this embodiment will be described with reference to FIG. FIG. 1 is a schematic diagram of a process cartridge 7 according to this embodiment. The developing unit 4 has a developing frame body 18 that supports various members in the developing unit 4. Here, the portion of the developing device frame 18 that contains the toner is referred to as a container body 19. The developing unit 4 is provided with a developing roller 22 that conveys toner to the photosensitive drum 1 by coming into contact with the photosensitive drum 1. The developing roller 22 carries toner and rotates in the direction of arrow D (counterclockwise) in FIG. The developing roller 22 is rotatably supported by the developing device frame 18 at both ends in the longitudinal direction (rotational axis direction) of the developing roller 22.

Further, the developing unit 4 includes a toner storage chamber 18a (corresponding to a developer storage chamber) which is a space inside the container body 19, a developing chamber 18b in which the developing roller 22 is disposed, a toner storage chamber 18a and a developing chamber. It has an opening 18c as a first opening communicating with 18b. The opening 18c is formed in a partition (partition 18m in FIG. 1) that partitions the toner storage chamber 18a and the developing chamber 18b. In this embodiment, the developing chamber 18b is located above the toner storage chamber 18a in the posture in which the developing unit 4 is normally used (posture in use). Further, in the developing chamber 18b, a toner supply roller 20 (corresponding to a supply member) that contacts the developing roller 22 and rotates in the arrow E direction, and a developing device that regulates the thickness of the toner layer formed on the developing roller 22. And a blade 21 (corresponding to a layer thickness regulating member). Here, as shown in FIG. 1, the developing blade 21 is in contact with the surface of the developing roller 22.
As shown in FIG. 1, the developing roller 22 and the toner supplying roller 20 rotate so that the surface of the developing roller 22 and the surface of the toner supplying roller 20 are directed in the same direction at their contact portions. In other words, when viewed in a direction along the rotation axis of the developing roller 22 or the rotation axis of the toner supply roller 20, the rotation direction of the development roller 22 is opposite to the rotation direction of the toner supply roller 20.

  Further, the toner storage chamber 18a inside the container body 19 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 22 and a stirring sheet 23b as a conveying member which is a flexible sheet. That is, the direction of the rotation axis of the stirring member 23 is parallel to the direction of the rotation axis of the developing roller 22. One end of the stirring sheet 23b is attached to the rotating shaft 23a, and the other end of the stirring sheet 23b is a free end. The rotating shaft 23a rotates and the stirring sheet 23b rotates, whereby the toner is stirred by the stirring sheet 23b. To be done. The stirring member 23 rotates so as to slide on a region including at least the bottom portion 18f on the inner wall surface of the container body 19. In this embodiment, the rotating shaft 23a extends substantially horizontally in the posture where the developing unit 4 is normally used.

  When the stirring member 23 stirs the toner, the stirring sheet 23b comes into contact with the inner wall surface of the container body 19, so that the stirring member 23 rotates with the stirring sheet 23b bent. Here, the inner wall surface of the container body 19 has a release position 18e that is a position where the stirring sheet 23b is released from the bent state. The stirring sheet 23b is released from the flexed state when passing through the release position 18e, and the restoring force released from the flexed state causes the toner on the stirring sheet to jump up. The toner that has jumped up is conveyed to the toner supply roller 20 in the developing chamber 18b through the opening 18c. The photoconductor unit 13 has a cleaning frame that supports the components that make up the photoconductor unit 13. The photosensitive drum 1 is attached to the cleaning frame so as to be rotatable in the direction of arrow A in FIG.

  The cleaning blade 6 is composed of an elastic member 6a for removing transfer residual toner (waste toner) remaining on the surface of the photosensitive drum 1 after the primary transfer, and a supporting member 6b for supporting the elastic member 6a. ing. The waste toner removed from the surface of the photosensitive drum 1 by the cleaning blade 6 is stored in a removed toner storage portion formed by the cleaning blade 6 and the cleaning frame. In the present embodiment, the developing container 190 has a configuration including the developing roller 22, the container body 19 and the stirring sheet 23b.

<Structure of seal provided in developing chamber 18b>
Next, the structure of the developing chamber 18b will be described with reference to FIGS. 1 and 4A to 4D. FIG. 1 is a schematic sectional view of a process cartridge 7 according to this embodiment. 4A to 4D are perspective views or schematic sectional views of the developing unit 4 according to the embodiment. Specifically, FIG. 4A is a perspective view of the developing unit 4, and FIG. 4B is a perspective view of the developing unit 4 with the bearing unit 26 and the developing roller 22 removed. 4C is a perspective view of the developing unit 4 with the elastic sheet 24, the developing blade 21, and the end seal member 25 removed from the developing unit 4 shown in FIG. 4B. FIG. 4D is a schematic sectional view of the developing unit 4 shown in FIG.

As shown in FIGS. 4C and 4D, in the developing chamber 18b, a developing opening 18d (corresponding to the third opening) surrounded by an upper edge portion 18h, a lower edge portion 18j, and both edge portions 18k. ) Is provided. A developing roller 22 carrying toner is rotatably provided in the developing opening 18d by a bearing unit 26. In addition, as shown in FIGS. 4A and 4B, at the lower edge portion 18j of the developing opening 18d, the developing frame body 18 extends toward the surface of the developing roller 22 and extends above the developing roller 22. A developing blade 21 for adjusting the thickness of the toner layer is provided.
Here, as shown in FIG. 4C, the length of the developing opening 18d in the rotation axis direction of the developing roller 22 is longer than the length of the developing opening 18d in the direction orthogonal to the rotation axis direction of the developing roller 22. That is, the longitudinal direction of the developing opening 18d is the same as the rotation axis direction of the developing roller 22. The lateral direction of the developing opening 18d is the same as the direction orthogonal to the rotation axis direction of the developing roller 22. The upper edge portion 18h and the lower edge portion 18j are edge portions extending along the longitudinal direction of the developing opening 18d. Both edges 18k correspond to the ends of the developing opening 18d in the longitudinal direction. Both edges 18k are edges extending along the lateral direction of the developing opening 18d.

  On the other hand, an elastic sheet 24 (corresponding to a sealing sheet) is provided on the developing device frame 18 at the upper edge portion 18h of the developing opening 18d. One end of the elastic sheet 24 is attached to the developing device frame 18. As shown in FIGS. 4A to 4D, one end of the elastic sheet 24 is attached to the upper edge portion 18h. That is, the upper edge portion 18h is a fixed portion to which the elastic sheet 24 is fixed. The other end of the elastic sheet 24 is in contact with the developing roller 22. As a result, the toner in the developing unit 4 is prevented from leaking through the gap between the developing roller 22 and the upper edge portion 18h. Further, both edge portions 18k forming the developing opening 18d are respectively provided with end seal members 25 so as to close the gaps between the developing frame 18, the developing roller 22, the developing blade 21, and the elastic sheet 24. The end seal member 25 has flexibility, and when attached to the developing unit 4, it makes pressure contact with the outer peripheral surface of the developing roller 22, the back surface of the developing blade 21, and the back surface of the elastic sheet 24. This prevents toner in the developing unit 4 from leaking out in the vicinity of both ends of the developing roller 22 in the rotation axis direction. That is, as shown in FIGS. 4A to 4D, in the longitudinal direction of the developing opening 18d, the inner end of the end seal member 25 provided at one end and the end provided at the other end in the longitudinal direction. The elastic sheet 24 is in contact with the developing roller 22 between the inner ends of the partial seals 25. The elastic sheet 24 and the end seal member 25 both have a function as a sealing member that suppresses development leakage from between the developing frame 18 and the developing roller 22.

<Structure in which Toner is Conveyed to Developing Room 18b>
Next, a configuration in which the toner in the toner storage chamber 18a (corresponding to the inside of the developer storage chamber) is transported to the developing chamber 18b will be described with reference to FIGS. Here, FIGS. 5A to 5E are views showing how the toner in the toner storage chamber 18a is conveyed to the developing chamber 18b. In this embodiment, the agitating sheet 23b contacts the inner wall surface of the toner storage chamber 18a to rotate in the toner storage chamber 18a in a bent state.

  Further, the toner storage chamber 18a is provided with a release position 18e for restoring the stirring sheet 23b from the bent state to the original state (non-deflected state). In this embodiment, on the inner wall surface of the toner storage chamber 18a, the portion at the release position 18e has a convex shape with respect to the portion around the release position 18e. The stirring sheet 23b jumps up the toner on the stirring sheet 23b by the restoring force generated when the stirring sheet 23b returns from the bent state to the original state at the timing of passing the release position 18e. As a result, the toner on the stirring sheet 23b is conveyed to the toner supply roller 20 in the developing chamber 18b via the opening 18c. That is, the stirring sheet 23b is deformable, and the toner is conveyed by releasing the deformation.

  Here, in a state where the stirring sheet 23b is not bent (natural state), the length (distance) from the tip of the stirring sheet 23b to the center of the rotation shaft 23a (the rotation axis of the stirring sheet 23b) is defined as the length W0. Further, the length from the bottom portion 18f of the toner storage chamber 18a to the rotating shaft 23a is defined as the length W1. Here, the bottom portion 18f is the lowermost portion of the bottom portion of the toner storage chamber 18a in the posture in which the developing unit 4 is normally used. In addition, in a cross section cut along a plane orthogonal to the rotation axis direction of the rotation shaft 23a (a cross section cut along a plane perpendicular to the rotation axis of the stirring sheet 23b), the rotation axis from the edge located below the edge of the opening 18c is rotated. The length up to 23a is defined as the length W2. Further, in this embodiment, the length W0> length W1 is satisfied as shown in FIG. 1 so that the toner in the bottom portion 18f of the toner storage chamber 18a is also conveyed to the developing chamber 18b. Further, the length W0 is larger than the length W2 so that the toner can be stably supplied to the developing chamber 18b. That is, the distance between the tip of the stirring sheet 23b in the undeformed state and the rotation axis of the stirring sheet 23b is larger than the shortest distance between the opening 18c and the rotation axis of the stirring sheet 23b. By setting the length W0 of the sheet 23b to be larger than the length W2, the stirring sheet 23b may collide with the toner supply opening 18c during rotation, and pressure fluctuations in the developing chamber 18b may easily occur. is there. The degassing opening described below can suppress the pressure fluctuation in such a case. As shown in FIG. 1, in the cross-sectional direction orthogonal to the rotation axis of the stirring sheet 23b (the orthogonal direction orthogonal to the direction of the rotation axis of the stirring sheet 23b), the deaeration opening 18g is provided inside the developing chamber 18b and the developing frame. It communicates with the outside of the body 18.

  Next, how the states of the stirring sheet 23b and the toner change while the stirring member 23 makes one revolution will be described with reference to FIGS. FIG. 5A shows a state before the rotating stirring sheet 23b starts to push the toner loaded in the toner storage chamber 18a. After that, in FIG. 5B, the stirring sheet 23b further rotates in the direction of the arrow F, so that the stirring sheet 23b starts to lift the toner in the toner storage chamber 18a upward.

  In FIG. 5C, the tip of the rotating stirring sheet 23b reaches the release position 18e. The toner is placed on the stirring sheet 23b, and the bent state of the stirring sheet 23b is restored to the original state at the timing when the tip of the stirring sheet 23b passes the release position 18e. Thus, as shown in FIG. 5D, the toner on the stirring sheet 23b is splashed up toward the opening 18c and the developing roller 22 by the restoring force when the stirring sheet 23b is restored. The toner on the stirring sheet 23b is pushed into the developing chamber 18b by the stirring sheet 23b colliding with the edge of the opening 18c. That is, the opening 18c is an opening for connecting the toner storage chamber 18a and the developing chamber 18b and allowing the toner conveyed from the toner storage chamber 18a to the developing chamber 18b to pass therethrough.

  At this time, as shown in FIG. 5D, the toner conveyed from the toner storage chamber 18a to the developing chamber 18b through the opening 18c passes above the toner supply roller 20 and moves toward the developing opening 18d. It is conveyed in the direction of arrow H. Further, the toner conveyed toward the developing opening 18d is directed to a portion where the toner supply roller 20 and the developing roller 22 contact each other, and a part of the toner is supplied to the developing roller 22.

  The toner not supplied to the developing roller 22 is caused by the rotation of the developing roller 22 and the toner supplying roller 20, the wall surface forming the developing chamber 18b, the developing blade 21 (see FIG. 1), the developing roller 22 and the toner supplying roller 20. Is conveyed to a region J surrounded by. Then, as shown in FIG. 5E, when a sufficient amount of toner is supplied to the developing chamber 18b, the area J is filled with the toner, and the excess toner is opened by the rotation of the toner supply roller 20. It returns to the toner storage chamber 18a via (is conveyed in the direction of arrow K).

<Structure of degassing opening 18g and filter 27>
In the present embodiment, the developing frame 18 is provided with the deaeration opening 18g (corresponding to the second opening) and the filter 27, so that the pressure in the developing chamber 18b rises and the toner enters the developing chamber 18b ( Leakage (corresponding to the outside of the developing chamber) is effectively suppressed. The deaeration opening 18g communicates the inside and outside of the developing chamber 18b. The deaeration opening 18g and the filter 27 will be described with reference to FIGS. 1, 6 (a), 6 (b) and FIG. Here, FIGS. 6A and 6B are perspective views of the process cartridge 7 according to the present embodiment, and FIG. 7 is a schematic cross-sectional view of the process cartridge 7 according to the present embodiment. Specifically, FIG. 6A is a perspective view of the process cartridge 7, and FIG. 6B is a perspective view of the process cartridge 7 with the filter 27 removed. Further, specifically, FIG. 7 is a cross-sectional view of the process cartridge in the case where the deaeration opening 18g is provided at a position different from that of the developing device frame 18 shown in FIG.

As shown in FIGS. 1 and 6A and 6B, the deaeration opening 18g extends in the longitudinal direction of the developing unit 4 (the rotation axis direction of the rotation shaft 23a) on the wall surface forming the development chamber 18b. Is formed. That is, the length of the deaeration opening 18g in the direction of the rotation axis of the rotation shaft 23a (the rotation axis of the stirring sheet 23b) is determined by degassing in the direction orthogonal to the rotation axis direction of the rotation shaft 23a (short direction of the developing unit 4). It is longer than the length of the opening 18g. By forming the deaeration opening 18g in the developing device frame 18, the outside of the developing unit 4 and the developing chamber 18b communicate with each other through the deaeration opening 18g. As described above, in the orthogonal direction orthogonal to the direction of the rotation axis of the stirring sheet 23b, the deaeration opening 18g communicates the inside of the developing chamber 18b with the outside of the developing frame 18 (FIG. 1). By arranging the deaeration opening 18g in such a direction, it is possible to effectively reduce the pressure fluctuation in the developing chamber 18b due to the stirring sheet 23b.
In this embodiment, the deaeration opening 18g has a rectangular shape and is provided over a wide area in the longitudinal direction of the developing unit 4. Note that, for example, as shown in FIGS. 1 and 4D, the degassing opening 18g and the opening 18c are configured to intersect with a single cross section in the direction orthogonal to the rotation axis of the stirring member 23. That is, when viewed from the orthogonal direction, at least a part of the deaeration opening 18g and at least a part of the opening 18c overlap each other. In other words, in the axial direction (longitudinal direction) of the rotary shaft 23a, at least a part of the range of the degassing opening 18g and the range of the opening 18c overlap.
It suffices that at least one deaeration opening 18g is formed in the developing device frame 18, and the larger the area of the deaeration opening 18g, the more the pressure in the developing chamber 18b can be reduced. In this embodiment, in order to sufficiently secure the rigidity of the developing device frame 18 and to sufficiently reduce the pressure of the developing chamber 18b, the developing device frame 18 is provided with two deaeration openings 18g. ing.

As shown in FIG. 1, a connection wall 18n is connected to the fixed portion (upper edge portion 18h). The connection wall 18n extends in a direction intersecting the direction in which the elastic sheet 24 extends in the orthogonal direction (direction orthogonal to the rotation axis of the developing roller 22 or the rotation axis of the stirring sheet 23b). The connection wall 18n can be said to be a wall surface that supports the fixed portion in the thickness direction of the elastic sheet 24 and supports the upper edge portion 18h that is the fixed portion. In the configuration shown in FIG. 1, the deaeration opening 18g is provided in the connection wall 18n.
Here, as shown in FIGS. 4 (a) to 4 (d) and FIGS. 6 (a) and 6 (b), the degassing openings 18g are provided at two places in this embodiment. At this time, the deaeration opening 18g is not arranged at the center of the development opening 18d in the longitudinal direction of the development opening 18d. That is, in the longitudinal direction, the degassing opening 18g is arranged at a position deviated from the central position of the developing opening 18d. In other words, in the longitudinal direction of the developing opening 18d, the central position of the developing opening 18d and the position of the connection wall 18n of the degassing opening 18g overlap.
By providing the degassing opening 18g on the connection wall 18n, which is the wall surface closest to the developing opening 18d, the pressure can be effectively reduced in the vicinity of the developing opening 18d. Further, the rigidity of the developing device frame 18 (in particular, the connecting wall 18n) can be increased at the central portion in the longitudinal direction.

Further, as shown in FIG. 6B, a convex portion 18p is provided around the deaeration opening 18g. Thereby, the rigidity of the developing device frame 18 can be increased around the deaeration opening 18g. In this embodiment, the convex portion 18p extends along the longitudinal direction and the lateral direction of the degassing opening 18g. And each convex part 18p is provided in both sides of the deaeration opening 18g. In addition, the convex portion 18p may be provided with a portion that extends in the lateral direction so as to cross between the deaeration openings 18g at the longitudinal center of the opening 18c.
Further, as shown in FIG. 1, a line connecting one end of the degassing opening 18g and one end of the opening 18c in the direction orthogonal to the rotation axis 23c is referred to as a first line L1. Further, a line connecting the other end of the degassing opening 18g and the other end of the opening 198c is referred to as a second line L2. At this time, the region between the first line L1 and the second line L2 can be said to be a region including the shortest route of the routes through which the air passing through the opening 18c reaches the degassing opening 18g. In the configuration shown in FIG. 1, at least a part of the supply roller 20 is arranged so as to be located outside the region between the first line L1 and the second line L2. By doing so, the area between the first line L1 and the second line L2 can be reduced from being narrowed by the supply roller 20. In addition, in a configuration in which a plurality of degassing openings 18g are provided, it is not necessary that all the degassing openings 18g have the above arrangement. That is, a part of the degassing openings 18g and the supply roller 20 may have the above-mentioned arrangement relationship.

Further, in the present embodiment, the deaeration opening 18g is provided on the top surface (connection wall 18n) of the developing device frame 18. Since the area J in the developing chamber 18b is basically always filled with toner, the deaeration opening 18g is provided on the surface that does not form the area J on the wall surface forming the developing chamber 18b. As a result, even when the developing unit 4 is in use, the pressure in the developing chamber 18b can be reduced without the toner in the developing chamber 18b blocking the deaeration opening 18g.
Further, the wall surface provided with the deaeration opening 18g is a wall surface where one surface forms the inner wall of the developing chamber 18b and the other surface which is the back surface of the one surface forms a part of the outer wall of the developing device frame 18. is there. As shown in FIG. 1, by providing the deaeration opening 18g on the widest wall surface among such wall surfaces, the size of the deaeration opening 18g can be increased. Although the deaeration opening 18g is provided on the top surface of the developing device frame 18 in this embodiment, the deaeration opening 18g is provided on the side surface of the developing device frame 18, as shown in FIG. 7, for example. May be.

  Further, as shown in FIG. 5D, the deaeration opening 18g is located upstream of the developing opening 18d in the direction in which the toner is conveyed in the developing chamber 18b (the rotation direction of the toner supply roller 20 (direction of arrow H)). And is arranged on the downstream side of the opening 18c. Further, in the supply path in which the toner is supplied from the opening 18c side (corresponding to the opening side) to the developing opening 18d side by the toner supply roller 20, the deaeration opening 18g is located between the opening 18c and the developing opening 18d. There is. Therefore, the air carried by the agitating sheet 23b from the toner storage chamber 18a is discharged from the degassing opening 18g before reaching the developing opening 18d where toner easily leaks. As a result, the pressure in the developing chamber 18b can be effectively reduced, and the toner can be prevented from leaking from the developing opening 18d.

  Further, the deaeration opening 18g is provided in the developing device frame 18 up to the vicinity of both ends in the longitudinal direction of the developing unit 4. As a result, it is possible to more effectively suppress the pressure from being applied to the end seal members 25 arranged at both ends of the developing opening 18d (both ends in the longitudinal direction of the developing unit 4). Therefore, it is possible to prevent the toner from leaking from both ends of the developing opening 18d. Further, as shown in FIGS. 6A and 6B, the filter 27 is provided so as to cover the deaeration opening 18g, and suppresses the toner from leaking out from the developing unit 4. That is, as shown in FIGS. 6A and 6B, the filter 27 is larger than the deaeration opening 18g when viewed from the normal direction of the surface on which the filter 27 is fixed. Further, the filter 27 is formed of a material that allows the air in the developing chamber 18b to pass therethrough.

The filter 27 is preferably made of a material having high air permeability. The higher the air permeability of the filter 27, the higher the effect of reducing the pressure in the developing chamber 18b. Therefore, the higher the air permeability of the filter 27, the more the leakage of the toner in the developing chamber 18b can be suppressed. In the present embodiment, the filter 27 is attached to the developing device frame 18 by welding from the outside of the wall surface of the developing device frame 18. However, the method of fixing the filter 27 to the developing device frame 18 is not limited to welding. For example, the filter 27 may be fixed to the developing device frame 18 with a double-sided tape or an adhesive. Further, for example, the filter 27 may be fixed from the inside of the developing unit 4. Further, the filter 27 may be integrally attached to the developing device frame 18 by being insert-molded to the developing unit 4. The filter 27 is fixed to the developing unit 4 so that the air in the developing chamber 18b can be discharged through the filter 27 and the toner in the developing chamber 18b can be prevented from leaking from the deaeration opening 18g. If you have.

  The number of filters 27 attached to the developing unit 4 may be at least one, and the number of filters 27 is not particularly limited. In this embodiment, the two degassing openings 18g are covered with two filters 27, respectively. However, the number of the deaeration openings 18g and the number of the filters 27 do not have to be the same, and for example, a plurality of the deaeration openings 18g may be covered with one filter 27. That is, as shown in FIGS. 8A to 8C, the deaeration opening 18g and the filter 27 may be arranged. 8 (a) to 8 (c) are diagrams showing an example of the arrangement of the degassing openings 18g and the filter 27 in this embodiment. FIGS. 8A to 8C are schematic views of the degassing opening 18g, the filter 27, the opening 18c, and the developing opening 18d, respectively, in a direction orthogonal to the rotation axis direction of the stirring sheet 23b. The arrow P indicates the direction of the rotation axis of the stirring sheet 23b. 8A to 8C, parts other than the degassing opening 18g, the filter 27, the opening 18c, and the developing opening 18d are omitted. When viewed from the direction of the rotation axis of the stirring sheet 23b, the deaeration opening 18g can be arranged at the position shown in FIG. It can also be arranged at the position shown in FIG.

  As described above, in the present embodiment, the developing chamber 18b is formed in the developing unit 4 in which the stirring sheet 23b rotates in the toner storage chamber 18a, so that the toner is conveyed from the toner storage chamber 18a to the developing chamber 18b. A degassing opening 18g is provided on the wall. As a result, even when air is carried into the developing chamber 18b by the stirring sheet 23b, it is possible to prevent the pressure inside the developing chamber 18b from rising, and to prevent the toner from leaking from the developing chamber 18b. can do.

Further, in the present embodiment, the deaeration opening 18g is blocked by the filter 27 that allows air to pass through instead of toner. That is, the filter 27 allows the air to pass through the deaeration opening 18g and restricts the passage of the toner. This can prevent the pressure in the developing chamber 18b from rising and prevent the toner from leaking from the developing chamber 18b through the deaeration opening 18g. In this embodiment, a non-woven fabric having an average diameter of 5 μm is used as the material of the filter in order to secure the collecting property and the air permeability.
Further, in this embodiment, the developing unit 4 is arranged on the opposite side of the fixing device 10 with respect to the intermediate transfer belt 5. As a result, the developing unit 4 can be suppressed from being affected by the heat generated by the fixing device 10.

In the present embodiment, the degassing opening 18g does not necessarily have to be closed by the filter 27. If the air is discharged from the degassing opening 18g and the toner is not discharged, the member that closes the degassing opening 18g may not be the filter 27.
Further, in this embodiment, the developing chamber 18b does not necessarily have to be arranged above the toner storage chamber 18a. For example, the developing chamber 18b may be arranged next to the toner storage chamber 18a in the horizontal direction.

  18 ... Development frame, 18a ... Toner storage chamber (developer storage chamber), 18b ... Development chamber, 18c ... Opening (first opening), 18d ... Development opening (third opening), 18g ... Degassing opening (second) Opening), 18n ... Connection wall, 20 ... Toner supply roller, 22 ... Developing roller, 23 ... Stirring member, 23b ... Stirring sheet, 24 ... Elastic sheet, 25 ... End seal member, 27 ... Filter, 190 ... Development container

Claims (20)

A developer carrying member for carrying a developer,
A transport member for transporting the developer,
A frame for storing the developer,
A developer storage chamber for storing the transport member,
A developing chamber in which the developer carrier is arranged,
A partition part for partitioning the developer accommodating chamber and the developing chamber, for communicating the developer accommodating chamber with the developing chamber, and passing the developer conveyed from the developer accommodating chamber to the developing chamber. A partition provided with a first opening,
A second opening that communicates the inside of the developing chamber with the outside of the frame in an orthogonal direction orthogonal to the direction of the rotation axis of the transport member;
With a frame,
A sealing member that suppresses the developer from leaking between the frame and the developer carrier,
A filter for allowing passage of air and restricting passage of a developer, the filter being fixed to the frame so as to cover the second opening,
Have,
By the deformation of the front Symbol conveying member is released such that said developer is conveyed to the developing chamber from said developer accommodating chamber via the first opening, the conveying member is constructed deformably A developing container characterized by the above. In the orthogonal direction, a distance between the tip of the transport member in the undeformed state and the rotation axis is larger than a shortest distance between the first opening and the rotation axis. Item 1. The developing container according to Item 1. Wherein the developing chamber, the developer container according to claim 1 or 2, characterized in a third the opening is provided to the developer carrying member is disposed. The second opening is located between the first opening and the third opening in a supply path through which the developer is supplied from the first opening toward the third opening. 3. The developing container according to item 3 . The developing container according to claim 3 , further comprising: a supply member that is housed inside the developing chamber and that supplies the developer to the developer carrier by coming into contact with the developer carrier.   A first line connecting one end of the first opening and one end of the second opening in the orthogonal direction, and a second line connecting the other end of the first opening and the other end of the second opening. The developing container according to claim 5, wherein, when pulled, at least a part of the supply member is located outside the region between the first line and the second line. The developing container according to claim 5, wherein the second opening is arranged on the upstream side of the third opening and on the downstream side of the first opening with respect to the rotation direction of the supply member. The transport member transports the developer such that the developer transported to the developing chamber through the first opening passes above the supply member,
The said 2nd opening is formed in the wall surface which faces the path | route which the developer conveyed to the said development chamber through the said 1st opening passes, The any one of Claim 5 to 7 characterized by the above-mentioned. Developer container. The sealing member is disposed at both edges of the third opening in the longitudinal direction, and is fixed to the frame body and an end seal that contacts the developer carrying member, and between the end seals, developer container according to any one of claims 3 to 8, characterized in that it comprises a sealing sheet in contact with the developer carrying member, a. The frame is a fixed portion to which the sealing sheet is fixed, and a connection wall connected to the fixed portion, and extends in a direction intersecting a direction in which the sealing sheet extends in the orthogonal direction. And a connection wall,
The developing container according to claim 9 , wherein the second opening is provided in the connection wall. Prior Symbol longitudinal direction, the second opening, the developer container according to claim 10, characterized in that disposed with respect to the position of the center of the third opening, shifted position. The developing container according to claim 1, wherein a convex portion is provided around the second opening. The convex portion has a first portion and a second portion extending in the direction of the rotation axis, the first portion is arranged on one side of the second opening, and the second portion is the The developing container according to claim 12, wherein the developing container is disposed on the other side of the second opening. Said frame member, a developing container according to any one of claims 1 to 13, wherein a plurality of the second openings are provided. The developing container according to claim 14, wherein the filter is attached to the outside of the frame so as to cover the plurality of second openings. In a posture in which the developing container is normally used, the developing chamber is disposed above the developer accommodating chamber, and the transport member lifts the developer accommodated in the developer accommodating chamber to remove the developer. developer container according to any one of claims 1 1 5 from the storage chamber, characterized in that conveys the developer to the developing chamber. The developing container according to any one of claims 1 to 16 , wherein the transport member is capable of contacting the partition section. A developing container according to any one of claims 1 to 17 ,
An image carrier on which a developer image is formed,
Have
A process cartridge, which is detachably attached to a main body of an image forming apparatus. A developing container according to any one of claims 1 to 17 ,
An image carrier on which a developer image is formed,
A fixing device for fixing the developer image on the recording medium;
An image forming apparatus comprising: An intermediate transfer member on which the developer image on the image carrier is primarily transferred,
A primary transfer member that primarily transfers the developer image on the image carrier to the intermediate transfer member;
A secondary transfer member that secondarily transfers the developer image primarily transferred to the intermediate transfer member to a recording medium,
The image forming apparatus according to claim 19 , wherein the developing container is disposed on the opposite side of the fixing device with respect to the intermediate transfer member.

Images