JP2018077458A - Development container, process cartridge and image formation apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress toner from leaking from the inside of a development chamber in a development container in which the toner is conveyed to the development chamber from a toner storage chamber with rotation of an agitation member.SOLUTION: A development container includes: a frame body being the frame body storing a developer which has: a developer storage chamber storing a conveyance member conveying the developer; a development chamber storing a developer carrier for carrying the developer; a first opening communicating the developer storage chamber with the development chamber and making the developer conveyed from the developer storage chamber to the development chamber pass therethrough; and a second opening communicating the inside of the development chamber with the outside of the frame body in the orthogonal direction orthogonal to the direction of the rotation axis of the conveyance member; a sealing member which suppresses the developer from leaking from the space between the frame body and the developer carrier; and a filter which permits passage of the air through the second opening, regulates passage of the developer through the second opening and is fixed to the frame body.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a developing container that stores 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 an apparatus main body on an 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 an image is formed on a recording material, first, the photosensitive drum is uniformly charged by a charging roller. Next, the charged photosensitive drum is selectively exposed by an exposure device, whereby an electrostatic latent image is formed on the photosensitive drum. The electrostatic latent image formed on the photosensitive drum is developed as a toner image using toner by a developing device. 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 a fixing device to form a recording material. To settle. 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, generally, process means such as a photosensitive drum, a charging roller, and a developing device 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. In general, a cartridge having such process means is called a process cartridge. The process cartridge can be attached to and detached from the apparatus main body of the image forming apparatus. By exchanging the process cartridge, the process means can be replaced and the process means can be maintained.

  Here, conventionally, there is known an in-line image forming apparatus in which a plurality of photosensitive drums are arranged substantially horizontally, and which transfers a toner image on the photosensitive drum to a recording material via an intermediate transfer belt. ing. In some image forming apparatuses, a plurality of photosensitive drums, a developing device, and an exposure device are disposed below the intermediate transfer belt. When the photosensitive drum, the developing device, and the exposure device are disposed below the intermediate transfer belt, the photosensitive drum, the developing device, and the exposure device are disposed on the opposite side of the fixing device with respect to the intermediate transfer belt in the image forming apparatus. Will be placed. Therefore, the photosensitive drum, the developing device, and the exposure device can be arranged at positions away from the fixing device. Thereby, it is possible to suppress 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 disposed below the intermediate transfer belt, generally, the developing chamber in which the developing roller for carrying the toner used for the development is disposed has toner. It is disposed above the toner storage chamber that is stored. The developing chamber and the toner storage chamber are communicated with each other through an opening. In such a developing device, the toner stored in the toner storage chamber needs to be conveyed through the opening to the developing chamber disposed above the toner storage chamber against gravity.

Therefore, conventionally, a developing device (developing container) is provided with a sheet-like stirring member, and when the stirring member rotates, the stirring member splashes toner accumulated at the bottom of the toner storage chamber into the developing chamber. I was raising. Specifically, the sheet-like stirring member rotates about a rotation center axis extending in a substantially horizontal direction to lift the toner accumulated at the bottom of the toner storage chamber. Further, in a state where the stirring member lifts the toner, the stirring member comes into contact with the inner wall surface of the toner storage chamber and bends. Then, by releasing the contact state between the inner wall surface of the toner storage chamber and the stirring member, the stirring member is restored to its original shape, and the toner on the stirring member jumps up into the developing chamber against gravity due to the restoring force. .

  By the way, the developing container is generally provided with a developing roller that is rotatably supported with respect to the frame of the developing container, and a developing blade that adjusts the layer thickness of the toner carried on the developing roller. Yes. 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 developing container frame and the developing roller. Further, the developing container includes a seal member for closing the gap between the developing roller and the frame, the gap between the developing blade and the frame, and the gap between the sheet member and the frame. It is provided near the end in the direction. This suppresses the toner in the developing container from leaking out of the developing container. However, when the pressure in the developing container increases, a pressure difference occurs between the inside and the outside of the developing container, and the gap between the sheet member and the developing roller or the gap between the developing container frame and the seal member. The toner may leak from the toner.

  Here, in the technique disclosed in Patent Document 1, in the configuration in which the developing chamber is disposed below the toner storage chamber, an opening is provided on the inner wall of the developing chamber, and the opening has air permeability. It is blocked by a filter. As a result, even when an impact is applied to the developing device, air is discharged from the opening, and the pressure in the developing chamber is reduced, thereby preventing the toner from leaking from the developing device.

  In the technique disclosed in Patent Document 2, the developing device is not provided with a developing chamber, and a developing roller is disposed in the toner storage chamber above a screw for conveying toner. An opening is provided in the inner wall of the toner storage chamber, and the opening is closed by a filter having air permeability. Then, an air flow is generated toward the opening, so that the 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. 57517979 Japanese Patent No. 4790676

  Here, in the developing container in which the sheet-like stirring member supplies the toner into the developing chamber, the stirring member rotates, so that the stirring member carries not only toner but also air into the developing chamber. Therefore, when the agitating member rotates, the pressure in the developing chamber rises and a pressure difference is generated between the inside and the outside of the developing container, so that the gap between the sheet member and the developing roller, the frame of the developing container, and the seal There is a possibility that the toner leaks from a gap with the member.

  Further, in recent years, since the image forming speed (printing speed) of the image forming apparatus has been increased, a large amount of toner needs to be supplied to the developing chamber. For that purpose, it is required to increase the rotation speed of the sheet-like stirring member or 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 in the developing chamber increases, and as described above, the gap between the sheet member and the developing roller, etc. The toner may leak from the toner.

Therefore, an object of the present invention is to suppress the leakage of toner from the developing chamber in the developing container in which the toner is transported from the toner storing chamber to the developing chamber by the rotation of the stirring member.

In order to achieve the above object, a developing container according to the present invention comprises:
A developer carrier for carrying the developer;
A transport member for transporting the developer, which is deformable and transports the developer by rotating and releasing the deformation; and
A frame for storing the developer,
A developer storage chamber for storing the conveying member;
A developing chamber for storing the developer carrier;
A first opening for allowing the developer conveyed from the developer accommodating chamber to the developing chamber through the developer accommodating chamber and the developing chamber;
A second opening communicating the inside of the developing chamber and the outside of the frame body in an orthogonal direction orthogonal to the direction of the rotation axis of the transport member;
A frame provided with,
A sealing member that suppresses leakage of the developer from between the frame and the developer carrier;
A filter that allows air to pass through the second opening and restricts developer from passing through the second opening, the filter being fixed to the frame;
It is characterized by having.

In order to achieve the above object, a process cartridge according to the present invention includes:
A developer container as described above;
An image carrier on which a developer image is formed;
Have
The image forming apparatus is detachable from the apparatus main body.

In order to achieve the above object, an image forming apparatus according to the present invention includes:
A developer container as described above;
An image carrier on which a developer image is formed;
A fixing device for fixing a developer image on a recording medium;
It is characterized by having.

  The present invention can suppress the leakage of toner from the developing chamber in the developing container in which the toner is transported from the toner storing chamber to the developing chamber by the rotation of the stirring member.

Schematic sectional view of a process cartridge according to an embodiment Schematic sectional view of an image forming apparatus according to an embodiment The figure which shows a mode that a process cartridge is inserted in the apparatus main body of an image forming apparatus. A perspective view and a schematic sectional view of a developing unit according to an embodiment The figure which shows a mode that the toner in a toner storage chamber is conveyed to a developing chamber. The perspective view of the process cartridge which concerns on an Example Schematic 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 are illustrated below with reference to the drawings. However, the dimensions, materials, shapes, and relative arrangements of the components described in the embodiments should be appropriately changed depending on the configuration of the apparatus to which the invention is applied and various conditions. This is not intended to limit the scope 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. FIG. 2 is a schematic diagram of the image forming apparatus 100 according to the present embodiment. FIG. 3 is a perspective view showing a state where the process cartridge 7 is attached to the image forming apparatus 100.

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

  In the present 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, when there is no need for distinction, the subscripts Y to K will be omitted and the description will be made comprehensively. In this embodiment, the image forming apparatus 100 includes 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 urged toward the photosensitive drum 1 in the direction of arrow C in FIG. The scanner unit 3 is an exposure unit that forms an electrostatic latent image on the photosensitive drum 1 (corresponding to the image carrier) by irradiating a laser based on the image information. 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 at least a developing roller 22 (see FIG. 1) as a developer carrying member for carrying the developer.

  Further, an intermediate transfer belt 5 (intermediate transfer) 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) facing the four photosensitive drums 1. Corresponding to the body) is arranged. In this embodiment, the developing unit 4 uses toner T (TY to TK) which is a nonmagnetic one-component developer. In this embodiment, the developing unit 4 performs contact development by bringing the developing roller 22 into contact with the photosensitive drum 1.

  The photosensitive unit 13 includes a removed toner storage unit (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 Furthermore, in this embodiment, the process cartridge 7 (7Y to 7K) is configured by integrally forming the developing unit 4 and the photosensitive unit 13 into a cartridge. The process cartridge 7 can be attached to and detached from the image forming apparatus 100 via mounting means such as a mounting guide (not shown) and a positioning member provided in the image forming apparatus 100. Further, the process cartridge 7 has a photosensitive drum 1 that carries at least a developer image.

In this embodiment, the process cartridge 7 can be attached to the apparatus main body of the image forming apparatus 100 in the direction of the arrow G in FIG. In this embodiment, the process cartridges 7 for the respective colors have the same shape. However, the present invention is not limited to this, and the shape and size may be different. For example, in order to increase the capacity of a black cartridge, it may be larger than other cartridges. The process cartridge 7 for each color stores 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 stretched around a plurality of support members (a driving roller 29, a secondary transfer counter roller 30, and a driven roller 28). Four primary transfer rollers 8 (8Y to 8K) (corresponding to primary transfer members) are arranged in parallel on the inner peripheral surface side of the intermediate transfer belt 5 so as to face the respective photosensitive drums 1. A secondary transfer roller 9 is disposed at a position facing the secondary transfer counter roller 30 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 photosensitive drum 1 is scanned and exposed by the laser light emitted from the scanner unit 3, whereby an electrostatic latent image based on image information is formed on the photosensitive drum 1. 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 a full-color image is formed, the above-described processes are sequentially performed in the first to fourth image forming units SY to SK, so that the toner images of the respective colors are sequentially superimposed on the intermediate transfer belt 5. Is done. Thereafter, the recording material 12 is conveyed to the secondary transfer portion in synchronization with the movement of the intermediate transfer belt 5. The four-color toner images on the intermediate transfer belt 5 are collectively collected 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. Secondary transferred on top.

  Thereafter, the recording material 12 onto which the toner image has been transferred is conveyed to the fixing device 10. When the recording material 12 is heated and pressurized 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. 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. Note that the image forming apparatus 100 can form a single-color or multi-color image using only a desired single or some (not all) image forming units. In this embodiment, the developing unit 4 is disposed 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 mounted on the image forming apparatus 100 according to the present embodiment will be described with reference to FIG. FIG. 1 is a schematic view of a process cartridge 7 according to the present embodiment. The developing unit 4 includes a developing frame 18 that supports various members in the developing unit 4. Here, a portion of the developing frame 18 that accommodates toner is referred to as a container main body 19. The developing unit 4 is provided with a developing roller 22 that conveys toner to the photosensitive drum 1 by contacting 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 supported by the developing frame 18 so as to be rotatable by bearings at both ends in the longitudinal direction (rotation axis direction).

Further, the developing unit 4 includes a toner storage chamber 18a (corresponding to the developer storage chamber) which is a space in the container body 19, a development chamber 18b in which the developing roller 22 is disposed, a toner storage chamber 18a and a development chamber. An opening 18c is provided as a first opening that communicates with 18b. The opening 18c is formed in a partition (partition 18m in FIG. 1) that partitions the toner storage chamber 18a and the development chamber 18b. In the present embodiment, the developing chamber 18b is positioned above the toner storage chamber 18a in a posture in which the developing unit 4 is normally used (post-use posture). 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 direction of arrow E, and a development that regulates the thickness of the toner layer formed on the developing roller 22 A blade 21 (corresponding to a layer thickness regulating member) is arranged. 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 supply roller 20 rotate so that the surface of the developing roller 22 and the surface of the toner supply roller 20 are directed in the same direction at the contact portion. In other words, when viewed in the 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 and the rotation direction of the toner supply roller 20 are opposite.

  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 transporting the toner to the toner supply roller 20 through the opening 18c. . The stirring member 23 includes a rotation shaft 23a parallel to the rotation axis direction of the developing roller 22, and a stirring sheet 23b as a conveyance member that 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 rotation shaft 23a, and the other end of the stirring sheet 23b is a free end. The rotation of the rotation shaft 23a and the rotation of the stirring sheet 23b causes the toner to be stirred by the stirring sheet 23b. Is done. The stirring member 23 rotates so as to slide with a region including at least the bottom 18 f of the inner wall surface of the container main body 19. In the present embodiment, the rotating shaft 23a extends in a substantially horizontal direction in a posture in which the developing unit 4 is normally used.

  When the agitating member 23 agitates the toner, the agitating sheet 23b comes into contact with the inner wall surface of the container main body 19, so that the agitating member 23 rotates while the agitating sheet 23b is 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. When the stirring sheet 23b passes the release position 18e, the stirring sheet 23b is released from the bent state, and the toner loaded on the stirring sheet jumps up by the restoring force released from the bent state. The splashed toner 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 constituting the photoconductor unit 13. A 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 includes an elastic member 6a for removing transfer residual toner (waste toner) remaining on the surface of the photosensitive drum 1 after primary transfer, and a support member 6b for supporting the elastic member 6a. ing. Waste toner removed from the surface of the photosensitive drum 1 by the cleaning blade 6 is accommodated in a removed toner accommodating portion formed by the cleaning blade 6 and the cleaning frame. In the present embodiment, a configuration including the developing roller 22, the container main body 19, and the stirring sheet 23b is referred to as a developing container 190.

<Structure of the seal provided in the developing chamber 18b>
Next, the configuration of the developing chamber 18b will be described with reference to FIGS. 1 and 4 (a) to 4 (d). FIG. 1 is a schematic cross-sectional view of a process cartridge 7 according to the present 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 in a state where the elastic sheet 24, the developing blade 21, and the end seal member 25 are removed from the developing unit 4 shown in FIG. 4B. FIG. 4D is a schematic cross-sectional view of the developing unit 4 shown in FIG.

As shown in FIGS. 4C and 4D, the developing chamber 18b has a developing opening 18d (corresponding to the third opening) surrounded by the upper edge 18h, the lower edge 18j, and both edges 18k. ) Is provided. In the developing opening 18d, a developing roller 22 carrying toner is rotatably provided by a bearing unit 26. Further, as shown in FIGS. 4A and 4B, at the lower edge portion 18j of the developing opening 18d, the developing frame 18 extends toward the surface of the developing roller 22 and is on 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 18 d in the rotation axis direction of the developing roller 22 is longer than the length of the developing opening 18 d 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 short side 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 18h and the lower edge 18j are edges that extend along the longitudinal direction of the developing opening 18d. Both edge portions 18k correspond to end portions in the longitudinal direction of the developing opening 18d. Both edge portions 18k are edge portions extending along the short side direction of the developing opening 18d.

  On the other hand, the developing frame 18 is provided with an elastic sheet 24 (corresponding to a sealing sheet) at the upper edge 18h in 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. Thereby, the toner in the developing unit 4 is prevented from leaking from the gap between the developing roller 22 and the upper edge portion 18h. Further, end seal members 25 are provided at both edge portions 18k forming the developing opening 18d so as to close the gaps between the developing frame 18, the developing roller 22, the developing blade 21, and the elastic sheet 24, respectively. The end seal member 25 has flexibility, and presses 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 when attached to the developing unit 4. As a result, the toner in the developing unit 4 is prevented from leaking 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 portion of the end seal member 25 provided on one end side and the end provided on the other end side are provided. The elastic sheet 24 is in contact with the developing roller 22 between the inner ends of the part seal 25. Each of the elastic sheet 24 and the end seal member 25 has a function as a sealing member that suppresses the leakage of development from between the developing frame 18 and the developing roller 22.

<Configuration in which toner is conveyed to developing chamber 18b>
Next, a configuration for conveying toner in the toner storage chamber 18a (corresponding to the developer storage chamber) to the development chamber 18b will be described with reference to FIGS. 5 (a) to 5 (e). Here, FIGS. 5A to 5E are views showing how 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 and rotates 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 (not bent). In this embodiment, the portion at the release position 18e on the inner wall surface of the toner storage chamber 18a has a convex shape with respect to the portion around the release position 18e. The stirring sheet 23b jumps up the toner placed 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 through the release position 18e. Thus, the toner on the stirring sheet 23b is conveyed to the toner supply roller 20 in the developing chamber 18b through the opening 18c. That is, the stirring sheet 23b can be deformed, 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 a length W0. The length from the bottom 18f of the toner storage chamber 18a to the rotating shaft 23a is defined as a 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. Further, in a cross section cut along a plane orthogonal to the rotation axis direction of the rotation shaft 23a (cross section cut along a plane orthogonal to the rotation axis line of the stirring sheet 23b), the rotation axis extends from the edge located below the edge of the opening 18c. The length up to 23a is defined as length W2. In this embodiment, the length W0> the length W1, as shown in FIG. 1, so that the toner in the bottom 18f of the toner storage chamber 18a is also conveyed to the development chamber 18b. Further, the length W0> 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 that is not deformed and the rotation axis of the stirring sheet 23b is greater 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 when rotating, and pressure fluctuation in the developing chamber 18b is likely to occur. is there. The pressure fluctuation in such a case can be suppressed by a deaeration opening to be described later. As shown in FIG. 1, in the cross-sectional direction orthogonal to the rotation axis of the stirring sheet 23b (orthogonal direction orthogonal to the direction of the rotation axis of the stirring sheet 23b), the deaeration opening 18g has an inside of the developing chamber 18b and a developing frame. It communicates with the outside of the body 18.

  Next, a state in which the state of the stirring sheet 23b and the toner changes while the stirring member 23 makes one round will be described with reference to FIGS. 5 (a) to 5 (e). FIG. 5A shows a state before the rotating stirring sheet 23b starts to push the toner loaded in the toner storage chamber 18a. Thereafter, 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 leading end of the rotating stirring sheet 23b reaches the release position 18e. The toner is placed on the stirring sheet 23b, and at the timing when the tip of the stirring sheet 23b passes the release position 18e, the stirring sheet 23b is restored from the bent state to the original state. As a result, as shown in FIG. 5D, the toner on the stirring sheet 23b is splashed toward the opening 18c and the developing roller 22 by the restoring force when the stirring sheet 23b is restored. Further, when the stirring sheet 23b collides with the edge of the opening 18c, the toner on the stirring sheet 23b is pushed into the developing chamber 18b. That is, the opening 18c communicates the toner storage chamber 18a and the developing chamber 18b and allows 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 are in contact with each other, and a part of the toner is supplied to the developing roller 22.

  Toner that has not been supplied to the developing roller 22 is rotated by the rotation of the developing roller 22 and the toner supply roller 20, the wall surface that forms the developing chamber 18 b, the developing blade 21 (see FIG. 1), the developing roller 22, the toner supply roller 20, Is transported 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 region J is filled with toner, and excess toner is opened by the rotation of the toner supply roller 20 to open the opening 18c. To the toner storage chamber 18a (conveyed in the direction of arrow K).

<Configuration of Deaeration Opening 18g and Filter 27>
In this 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, 6A, 6B, and 7. 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 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. Specifically, FIG. 7 is a cross-sectional view of the process cartridge when a deaeration opening 18g is provided at a position different from the developing frame 18 shown in FIG.

As shown in FIGS. 1 and 6 (a) and 6 (b), the deaeration opening 18g extends in the longitudinal direction of the developing unit 4 (the rotational axis direction of the rotating shaft 23a) on the wall surface forming the developing chamber 18b. Is formed. That is, the length of the degassing opening 18g in the direction of the rotation axis of the rotation shaft 23a (the rotation axis of the stirring sheet 23b) is degassed 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 degassing opening 18g in the developing frame 18, the outside of the developing unit 4 and the developing chamber 18b communicate with each other through the degassing opening 18g. As described above, the deaeration opening 18g communicates the inside of the developing chamber 18b and the outside of the developing frame 18 in the orthogonal direction orthogonal to the direction of the rotation axis of the stirring sheet 23b (FIG. 1). By arranging the deaeration opening 18g in such a direction, the pressure fluctuation in the developing chamber 18b due to the stirring sheet 23b can be effectively reduced.
In this embodiment, the deaeration opening 18 g is rectangular and is provided over a wide area in the longitudinal direction of the developing unit 4. For example, as shown in FIGS. 1 and 4D, the deaeration opening 18 g and the opening 18 c 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. In other words, at least a part of the range of the deaeration opening 18g and the range of the opening 18c overlap in the axial direction (longitudinal direction) of the rotation shaft 23a.
It is sufficient that at least one deaeration opening 18g is formed in the developing frame 18, and the pressure of the developing chamber 18b can be reduced as the area of the deaeration opening 18g increases. In this embodiment, in order to sufficiently secure the rigidity of the developing frame 18 and to sufficiently reduce the pressure in the developing chamber 18b, the developing frame 18 is provided with deaeration openings 18g at two locations. ing.

As shown in FIG. 1, a connecting wall 18n is connected to the fixed portion (upper edge portion 18h). The connection wall 18n extends in a direction intersecting with the direction in which the elastic sheet 24 extends in the orthogonal direction (the 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 also be said to be a wall surface that supports the fixed portion in the thickness direction of the elastic sheet 24 and 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. 4A to 4D and FIGS. 6A and 6B, in this embodiment, the deaeration openings 18g are provided in two places. 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 deaeration opening 18g is disposed at a position shifted from the center position of the development opening 18d. In other words, in the longitudinal direction of the developing opening 18d, the center position of the developing opening 18d and the position of the connection wall 18n of the deaeration 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. Furthermore, the rigidity of the developing device frame 18 (particularly, the connection wall 18n) can be increased at the center 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 the present embodiment, the convex portion 18p extends along the longitudinal direction and the short direction of the deaeration opening 18g. And each convex part 18p is provided in the both sides of the deaeration opening 18g. In addition, the convex part 18p may be provided with the part extended in a transversal direction so that it may cross between the deaeration openings 18g in the longitudinal center of the opening 18c.
Further, as shown in FIG. 1, a line connecting one end of the deaeration opening 18g and one end of the opening 18c in a direction orthogonal to the rotation shaft 23c is defined as a first line L1. Further, a line connecting the other end of the deaeration opening 18g and the other end of the opening 198c is defined 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 path among the paths through which the air that has passed through the opening 18c reaches the deaeration opening 18g. In the configuration illustrated in FIG. 1, at least a part of the supply roller 20 is disposed outside the region between the first line L1 and the second line L2. By doing so, it is possible to reduce the area between the first line L1 and the second line L2 from being narrowed by the supply roller 20. In the configuration in which a plurality of deaeration openings 18g are provided, it is not necessary that all the deaeration openings 18g are arranged as described above. That is, a part of the deaeration openings 18g and the supply roller 20 may have the above-described arrangement relationship.

In this embodiment, the deaeration opening 18g is provided on the top surface (connection wall 18n) of the developing device frame 18. Since the region J in the developing chamber 18b is basically always filled with toner, the deaeration opening 18g is provided on a surface that does not constitute the region J on the wall surface that forms the developing chamber 18b. Thereby, even while the developing unit 4 is used, 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 in which 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 further increased. In this embodiment, the deaeration opening 18g is provided on the top surface of the developing device frame 18. For example, as shown in FIG. 7, the degassing opening 18g is provided on the side surface of the developing device frame 18. May be.

  As shown in FIG. 5D, the deaeration opening 18g is upstream of the development opening 18d in the direction in which the toner is conveyed in the development chamber 18b (the rotation direction of the toner supply roller 20 (arrow H direction)). It arrange | positions and is arrange | positioned downstream from the opening 18c. Further, in the supply path in which toner is supplied from the opening 18c side (corresponding to the opening side) by the toner supply roller 20 to the development opening 18d side, the deaeration opening 18g is located between the opening 18c and the development opening 18d. Yes. Therefore, the air conveyed by the stirring sheet 23b from the toner storage chamber 18a is discharged from the deaeration opening 18g before reaching the developing opening 18d where the toner easily leaks. Thereby, the pressure in the developing chamber 18b can be effectively reduced, and the leakage of toner from the developing opening 18d can be suppressed.

  Further, the deaeration opening 18 g is provided in the developing device frame 18 to the vicinity of both ends in the longitudinal direction of the developing unit 4. Thereby, it can suppress more effectively that a pressure is applied with respect to the edge part sealing member 25 arrange | positioned at the both ends (both ends in the longitudinal direction of the developing unit 4) of the developing opening 18d. Therefore, the toner can be prevented from leaking from both end portions 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 of 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 to which the filter 27 is fixed. The filter 27 is formed of a material that allows air in the developing chamber 18b to pass therethrough.

The filter 27 is preferably formed from 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 toner in the developing chamber 18b can be further prevented from leaking. In this embodiment, the filter 27 is attached to the developing frame 18 by welding from the outside of the wall surface of the developing frame 18. However, the method of fixing the filter 27 to the developing frame 18 is not limited to welding. For example, the filter 27 may be fixed to the developing frame 18 with a double-sided tape or an adhesive. 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 frame 18 by insert molding with respect to the developing unit 4. The filter 27 is fixed to the developing unit 4 so that the air in the developing chamber 18b is discharged through the filter 27 and the toner in the developing chamber 18b can be prevented from leaking from the deaeration opening 18g. It only has to be.

  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 by the two filters 27, respectively. However, the number of the deaeration openings 18g and the number of the filters 27 may not be the same. 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 can be arranged. FIGS. 8A to 8C are diagrams showing examples of arrangement of the deaeration openings 18g and the filters 27 in the present embodiment. 8A to 8C are schematic views of the deaeration opening 18g, the filter 27, the opening 18c, and the development opening 18d as viewed from the direction orthogonal to the rotation axis direction of the stirring sheet 23b. The arrow P represents the rotational axis direction of the stirring sheet 23b. 8A to 8C, portions other than the deaeration opening 18g, the filter 27, the opening 18c, and the development opening 18d are omitted. When viewed from the direction of the rotation axis of the stirring sheet 23b, the deaeration opening 18g can be disposed at the position shown in FIG. Moreover, it can also arrange | position in the position shown in FIG.

  As described above, in this embodiment, the developing sheet 18b is formed in the developing unit 4 in which the toner is transported from the toner storage chamber 18a to the development chamber 18b by rotating the stirring sheet 23b in the toner storage chamber 18a. The wall portion is provided with a deaeration opening 18g. As a result, even when air is carried into the developing chamber 18b by the stirring sheet 23b, it is possible to suppress the pressure in the developing chamber 18b from increasing, and to prevent the toner from leaking from the developing chamber 18b. can do.

Further, in the present embodiment, the deaeration opening 18g is closed by a filter 27 that does not allow toner to pass but allows air to pass. That is, the filter 27 allows air to pass through the deaeration opening 18g and restricts toner from passing therethrough. Accordingly, it is possible to suppress the pressure in the developing chamber 18b from increasing and to prevent the toner from leaking from the developing chamber 18b through the deaeration opening 18g. In this embodiment, the filter material is a non-woven fabric having an average diameter of 5 μm in order to ensure the collection and breathability.
In this embodiment, the developing unit 4 is disposed on the opposite side of the fixing device 10 with respect to the intermediate transfer belt 5. Thereby, it is possible to suppress the development unit 4 from being affected by heat generated from the fixing device 10.

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

  18 ... developing frame, 18a ... toner storage chamber (developer storage chamber), 18b ... developing chamber, 18c ... opening (first opening), 18d ... developing opening (third opening), 18g ... deaeration 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 ... developing container

Claims (14)

A developer carrier for carrying the developer;
A transport member for transporting the developer, which is deformable and transports the developer by rotating and releasing the deformation; and
A frame for storing the developer,
A developer storage chamber for storing the conveying member;
A developing chamber for storing the developer carrier;
A first opening for allowing the developer conveyed from the developer accommodating chamber to the developing chamber through the developer accommodating chamber and the developing chamber;
A second opening communicating the inside of the developing chamber and the outside of the frame body in an orthogonal direction orthogonal to the direction of the rotation axis of the transport member;
A frame provided with,
A sealing member that suppresses leakage of the developer from between the frame and the developer carrier;
A filter that allows air to pass through the second opening and restricts developer from passing through the second opening, the filter being fixed to the frame;
A developing container comprising:   The developing container according to claim 1, wherein the developing chamber is provided with a third opening in which the developer carrying member is disposed.   2. The supply path for supplying a developer from the first opening toward the third opening, wherein the second opening is positioned between the first opening and the third opening. The developing container according to 2.   The distance between the front end of the conveying member that is not deformed and the rotation axis in the orthogonal direction is greater than the shortest distance between the first opening and the rotation axis. Item 4. The developing container according to Item 2 or 3.   5. The apparatus according to claim 2, further comprising a supply member that is housed in the developing chamber and that supplies the developer to the developer carrier by contacting the developer carrier. The developing container according to 1. 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 a region between the first line and the second line.   The sealing member includes an end seal disposed at both edges in the longitudinal direction of the third opening, and a seal that is fixed to the frame body and that contacts the developer carrier between the end seals. The developing container according to claim 2, further comprising a stop sheet. The frame body 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 the direction in which the sealing sheet extends in the orthogonal direction. A connecting wall, and
The developing container according to claim 7, wherein the second opening is provided in the connection wall. The frame body is provided with a plurality of the second openings,
The developing container according to claim 8, wherein in the longitudinal direction, the second opening is disposed at a position shifted from a center position of the third opening.   The developing container according to claim 1, wherein the frame body includes a plurality of the second openings.   In a posture in which the developer container is normally used, the developer chamber is disposed above the developer storage chamber, and the transport member lifts the developer stored in the developer storage chamber, thereby the developer. The developer container according to claim 1, wherein the developer is transported from a storage chamber to the developing chamber. A developing container according to any one of claims 1 to 11,
An image carrier on which a developer image is formed;
Have
A process cartridge which is detachable from an apparatus main body of an image forming apparatus. A developing container according to any one of claims 1 to 11,
An image carrier on which a developer image is formed;
A fixing device for fixing a developer image on a recording medium;
An image forming apparatus comprising: An intermediate transfer member to which a developer image on the image carrier is primarily transferred;
A primary transfer member that primarily transfers a 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 13, wherein the developing container is disposed on a side opposite to the fixing device with respect to the intermediate transfer member.

Images