JP2021047232A - Developing device, process cartridge, and image forming apparatus - Google Patents

Abstract

To provide a developing device that achieves a configuration that can supply a developer from the lower part to the upper part, and improves the miscibility of a developer newly supplied to a developer storage chamber from a supply port and an existing developer, a process cartridge, and an image forming apparatus.SOLUTION: A developer storage chamber is provided with a supply port for supplying a developer to the developer storage chamber from the outside. In the posture in use, when viewed along a rotation axis direction of a rotary shaft part, with a perpendicular passing through the center of rotation of the rotary shaft part as a reference, at least part of a communication port and at least part of the supply port are both located on one side with respect to the perpendicular, and a restoration unit is located on the other side with respect to the perpendicular.SELECTED DRAWING: Figure 6

Description

The present invention relates to a developing device, a process cartridge and an image forming device. In particular, the present invention relates to an electrophotographic image forming apparatus adopting an electrophotographic method, a developing apparatus used in the electrophotographic image forming apparatus, and a process cartridge.

Conventionally, there is a wide range of configurations in which a developing cartridge (including developing means) and a process cartridge (including developing means and a photoconductor drum) can be attached to and detached (replaceable) from the main body of the electrophotographic image forming apparatus. Are known.

Among them, a cartridge as in Patent Document 1 in which the developer is transferred from the lower developer storage chamber to the upper developer chamber through the communication port by elastic deformation (elastic restoring force) of the stirring sheet. Existing.

On the other hand, in order to improve the image formation efficiency, there is also a technique of providing a replenishment port in the developer storage chamber of the cartridge as in Patent Document 1 and directly replenishing the developer from the outside to the developer storage chamber via the replenishment port. It is being considered.

JP 2011-253203

However, in the cartridge described in Patent Document 1, when a replenishment port is provided in the developer storage chamber, the developer newly replenished from the replenishment port to the developer storage chamber is not sufficiently mixed with the existing toner. , May be transported to the upper developing room via the communication port. This can reduce the stability of the formed image.

The present invention realizes a configuration capable of supplying a developer from below to above, and improves the mixing property of the developer newly supplied to the developer storage chamber from the supply port and the existing developer. It is an object of the present invention to provide a process cartridge and an image forming apparatus.

The developing apparatus of the present invention
A developing room in which a developing agent carrier carrying a developing agent is housed, a developing agent storage room located below the developing room in a posture during use and storing the developing agent, and the developing room and the developing agent storage room. With a developing frame body, which has a communication port for communicating with
A transport member provided in the developing agent accommodating chamber and conveying the developing agent contained in the developing agent accommodating chamber to the developing chamber, the rotatable rotating shaft portion and one end fixed to the rotating shaft portion. A transport member including a sheet portion having a free end at the other end and elastically deformable.
A deformed portion provided in the developer accommodating chamber and abutting with the free end of the sheet portion that rotates with the rotational operation of the rotating shaft portion to bend and elastically deform the sheet portion.
The sheet portion provided in the developer accommodating chamber at a position upstream of the communication port and downstream of the deformed portion in the rotation direction of the rotating shaft portion, and elastically deformed by the deformed portion. A restoration unit that allows the developer carried on the sheet portion to fly toward the communication port by releasing and restoring the processing unit, and a restoration unit.
It is a developing device having
The developer accommodating chamber is provided with a supply port for replenishing the developer from the outside to the developer accommodating chamber.
When viewed along the direction of the rotation axis of the rotation shaft in the posture during use, when the vertical line passing through the rotation center of the rotation shaft is used as a reference,
At least a part of the communication port and at least a part of the supply port are both located on one side of the vertical line.
The restored portion is located on the opposite side of the perpendicular line.

Further, the process cartridge of the present invention is characterized in that it includes an image carrier for carrying a developer image and the developing device, and is removable from the image forming device.

Further, the image forming apparatus of the present invention is characterized by including at least one of the developing apparatus or the process cartridge, and a transfer member.

According to the present invention, it is possible to realize a configuration in which the developer can be supplied from the developing agent storage chamber located below to the developing chamber located above, and the developer newly supplied to the developing agent storage chamber from the supply port. The mixability of existing developing agents can be improved.

Conceptual cross-sectional view of the image forming apparatus according to the embodiment of the present invention Conceptual sectional view of a process cartridge used in the image forming apparatus according to the embodiment of the present invention. Conceptual perspective view from above the drive side of the process cartridge according to the embodiment of the present invention. Conceptual perspective view from above the drive side of the developing unit used in the image forming apparatus according to the embodiment of the present invention. (A) Conceptual diagram showing a stirring state of toner in a developing unit according to an embodiment of the present invention; (b) Conceptual diagram showing a free length L (free state) of a sheet member of a stirring member. A conceptual diagram showing regions A and B in a developing unit according to an embodiment of the present invention. (A) Conceptual diagram showing the posture of the developing unit and the position of the supply port according to the embodiment of the present invention; (b to d) Conceptual diagram showing the posture of the developing unit and the position of the supply port in the comparative example with respect to the embodiment of the present invention. The conceptual diagram which shows the circulation of the toner in the developing unit of the Example of this invention.

The present invention can be implemented as either an electrophotographic image forming apparatus (hereinafter, may be simply referred to as an "image forming apparatus"), a process cartridge forming a part of the image forming apparatus, or a developing apparatus. Is.

Hereinafter, the image forming apparatus according to the present invention will be described with reference to the drawings.

The examples described below exemplify the present invention, and the dimensions, materials, shapes, relative positional relationships, and the like of the components described below are particularly specific. Unless not, the scope of the invention is not limited thereto.

Here, the electrophotographic image forming apparatus is an device that forms an image on a recording medium by using an electrophotographic image forming method. Examples of the electrophotographic image forming apparatus include, for example, an electrophotographic copying machine, an electrophotographic printer (for example, a laser beam printer, an LED printer, etc.), a facsimile machine, a word processor, and the like.

Further, the developing device used in the image forming device has at least a developing means. In addition, the developing device can be made into a cartridge and attached to and detached from the main body of the electrophotographic image forming device. Further, the developing apparatus may include a toner cartridge that is detachable from the frame of the developing apparatus and can supply toner to the developing apparatus.

Further, the process cartridge forming a part of the image forming apparatus is obtained by integrally forming a charging means, a developing means or a cleaning means and an electrophotographic photosensitive member drum into a cartridge, and this cartridge is used for the main body of the electrophotographic image forming apparatus. It is removable. Further, at least one of the charging means, the developing means, and the cleaning means and the electrophotographic photosensitive member drum are integrally formed into a cartridge so that they can be attached to and detached from the main body of the electrophotographic image forming apparatus. Further, at least the developing means and the electrophotographic photosensitive member drum are integrally formed into a cartridge so that they can be attached to and detached from the main body of the electrophotographic image forming apparatus. It is also possible to use the process cartridge fixed to the image forming apparatus.

Hereinafter, the image forming apparatus and the process cartridge according to the present invention will be described with reference to the drawings.

<Overall configuration of image forming device>
First, the overall configuration of the electrophotographic image forming apparatus 100 (hereinafter, simply referred to as an image forming apparatus) will be described with reference to FIG.

FIG. 1 is a conceptual cross-sectional view of an image forming apparatus according to an embodiment of the present invention.

As shown in FIG. 1, four detachable process cartridges 70 (70Y, 70M, 70C, 70K) are mounted by mounting members (not shown). Further, the upstream side of the image forming apparatus 100 of the process cartridge 70 in the mounting direction is defined as the front side surface side, and the downstream side in the mounting direction is defined as the back side surface side.

Each process cartridge 70 includes a photoconductor drum 1 (1a to 1d), a charging roller 2 (2a to 2d) around the photoconductor drum 1 (image carrier), and a developing roller 25 (25a to 25d). Process means such as cleaning members 6 (6a to 6d) are integrally arranged.

The charging roller 2 uniformly charges the surface of the photoconductor drum 1, and the developing roller 25 (developer carrier) uses a latent image formed on the photoconductor drum 1 as a toner (hereinafter referred to as a developing agent). In some cases), it is developed and made into a visible image. Then, the cleaning member 6 removes the developer remaining on the photoconductor drum 1 after transferring the toner image formed on the photoconductor drum 1 to the recording medium.

Further, below the process cartridge 70, a scanner unit 3 for selectively exposing the photoconductor drum 1 based on image information and forming a latent image on the photoconductor drum 1 is provided.

A cassette 17 containing the recording medium S is mounted on the lower portion of the apparatus main body 100A of the image forming apparatus 100. A recording medium transporting means is provided so that the recording medium S passes through the secondary transfer roller 69 and the fixing portion 74 and is transported above the apparatus main body 100A.

That is, the feeding roller 54 that separates and feeds the recording media S in the cassette 17 one by one, the transport roller pair 76 that conveys the fed recording medium S, and the latent image and the recording medium formed on the photoconductor drum 1. A resist roller pair 55 for synchronizing with S is provided.

Further, above the process cartridge 70 (70Y, 70M, 70C, 70K), an intermediate transfer unit 5 is provided as an intermediate transfer means for transferring the toner image formed on each of the photoconductor drums 1 (1a to 1d). Has been done.

The intermediate transfer unit 5 includes a drive roller 56, a driven roller 57, a primary transfer roller 58 (58a to 58d) at a position facing the photoconductor drum 1 of each color, and an opposing roller 59 at a position facing the secondary transfer roller 69. It has a transfer belt 50 and is hung on it.

Then, the transfer belt 50 circulates so as to face and contact all the photoconductor drums 1, and by applying a voltage to the primary transfer roller 58 (transfer member), the transfer belt 50 is moved from the photoconductor drum 1 onto the transfer belt 50. Perform primary transcription. By applying a voltage to the opposing 59 rollers and the secondary transfer roller 69 arranged in the transfer belt 50, the toner of the transfer belt 50 is transferred to the recording medium S.

At the time of image formation, each photoconductor drum 1 is rotated, and the photoconductor drum 1 uniformly charged by the charging roller 2 is selectively exposed from the scanner unit 3. As a result, an electrostatic latent image is formed on the photoconductor drum 1.

Further, the electrostatic latent image is developed by the developing roller 25 to form each color toner image on each photoconductor drum 1. In synchronization with this image formation, the resist roller pair 55 conveys the recording medium S to the secondary transfer position where the opposing roller 59 and the secondary transfer roller 69 are in contact with each other with the transfer belt 50 interposed therebetween.

Then, by applying a transfer bias voltage to the secondary transfer roller 69, each color toner image on the transfer belt 50 is secondarily transferred to the recording medium S. As a result, a color image is formed on the recording medium S.

The recording medium S on which the color image is formed is heated and pressurized by the fixing unit 74 to fix the toner image. After that, the recording medium S is discharged to the discharge unit 75 by the discharge roller 72. The fixing portion 74 is arranged above the apparatus main body 100A.

The first to fourth toner cartridges 9 are arranged horizontally below the process cartridge 70 in an order corresponding to the color of the toner contained in each process cartridge 70.

That is, the first toner cartridge 9Y contains yellow (Y) toner, similarly, the second toner cartridge 9M is magenta (M), the third toner cartridge 9C is cyan (C), and the fourth toner cartridge 9C. Toner cartridge 9K stores black (K) toner. Then, each toner cartridge 9 replenishes the process cartridge 70 containing the toner of the same color.

The toner cartridge 9 replenishment operation is performed when the remaining amount detecting unit (not shown) provided in the apparatus main body 100A of the image forming apparatus 100 detects the remaining amount of toner in the process cartridge 70. The toner cartridge 9 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 (not shown) provided in the image forming apparatus 100. A detailed description of the process cartridge 70 and the toner cartridge 9 will be described later.

Below the toner cartridge 9, first to fourth toner transfer devices 18 are arranged corresponding to each toner cartridge 9. Each toner transfer device 18 conveys the toner received from each toner cartridge 9 upward, and supplies the toner to each development unit 4 (development device).

<Process cartridge>
Next, the process cartridge 70 in which the present invention has been carried out will be described with reference to FIG.

FIG. 2 is a conceptual cross-sectional view of a process cartridge used in the image forming apparatus according to the embodiment of the present invention.

Specifically, FIG. 2 shows the main cross section of the process cartridge 70 containing the toner. The cartridge 70Y containing yellow toner, the cartridge 70M containing magenta toner, the cartridge 70C containing cyan toner, and the cartridge 70K containing black toner have the same configuration.

The process cartridge 70 (70Y, 70M, 70C, 70K) has a cleaning unit 26 (26a to 26d) and a developing unit 4 (4a to 4d). The cleaning unit 26 includes a photoconductor drum 1 (1a to 1d), a charging roller 2 (2a to 2d), and a cleaning member 6 (6a to 6d). The developing unit 4 (developing apparatus) includes a developing roller 25.

As described above, the charging roller 2 and the cleaning member 6 are arranged on the periphery of the photoconductor drum 1. The cleaning member 6 is composed of an elastic member 7 formed of a rubber blade and a cleaning support member 8.

The tip portion 7a of the rubber blade 7 is arranged so as to be in contact with the rotation direction of the photoconductor drum 1 in the counter direction. Then, the residual toner removed from the surface of the photoconductor drum 1 by the cleaning member 6 falls into the removal toner chamber 27a.

Further, the squeeze sheet 21 for preventing the removal toner from the removal toner chamber 27a from leaking is in contact with the photoconductor drum 1. Then, by transmitting the driving force of the main body driving motor (not shown) which is the driving source to the cleaning unit 26, the photoconductor drum 1 is rotationally driven according to the image forming operation.

The charging roller 2 is rotatably attached to the cleaning unit 26 via the charging roller bearing 28, is pressurized toward the photoconductor drum 1 by the charging roller pressurizing member 46, and is driven to rotate by the photoconductor drum 1. ..

<Development unit and toner transfer means>
Next, the developing unit and the toner transporting means will be described with reference to FIGS. 2 to 5.

FIG. 3 is a perspective conceptual view of the process cartridge according to the embodiment of the present invention as viewed from above on the drive side.

FIG. 4 is a perspective conceptual diagram seen from above the drive side of the developing unit used in the image forming apparatus according to the embodiment of the present invention.

FIG. 5A is a conceptual diagram showing a stirring state of toner in the developing unit according to the embodiment of the present invention. FIG. 5B is a conceptual diagram showing a free length L (free state) of the sheet member of the stirring member.

As shown in FIGS. 2 and 3, the developing unit 4 includes a developing roller 25 that rotates in contact with the photoconductor drum 1 and a developing frame 31 that supports the developing roller 25.

The developing roller 25 is rotatably supported by the developing frame 31 via the pre-developing bearings 12 and the developing back bearings 13 attached to both sides of the developing frame 31 (see FIG. 4). Further, on the circumference of the developing roller 25, a toner supply roller 34 (supply member) that contacts the developing roller 25 and rotates in the direction of arrow C and a developing blade 35 for regulating the toner layer on the developing roller 25 are arranged. Has been done.

When the toner supplied from the toner supply roller 34 to the developing roller 25 passes through the developing blade 35, the amount of toner coated on the developing roller 25 is regulated and the toner is charged. This forms an optimal toner coat for developing the latent image created on the photoconductor drum.

The developing roller 4 and the photoconductor drum 1 rotate so that their surfaces move in the same direction (in this embodiment, from the bottom to the top) at the facing portion (contact portion). In this embodiment, in the developing section where the toner negatively charged by triboelectric charging with respect to the predetermined DC bias applied to the developing roller 17 comes into contact with the photoconductor drum 1, the bright area potential portion is determined from the potential difference. The electrostatic latent image is visualized by transferring only to.

Further, a blowout prevention sheet 20 as a development contact sheet for preventing toner from leaking from the development frame 31 in contact with the development roller 25 is arranged. Further, the toner storage chamber 31a (developer storage chamber) of the developing frame 31 is provided with a toner transport member 36 (conveyor member) for stirring the stored toner and transporting the toner to the toner supply roller 34. There is.

As shown in FIG. 5A, the toner transport member 36 is a stirring shaft 36a (rotating shaft portion) that can be rotated by an external driving force, and a sheet member that is attached to the stirring shaft 36a and rotates together with the stirring shaft 36a. It is composed of 36b (seat portion).

Next, the toner transfer of the developing unit will be described. The toner storage chamber 31a is provided with a deformed portion 31a1 that comes into contact with the sheet member 36b below the opening 31c (communication port). The seat member 36b comes into contact with the deformed portion 31a1 as it rotates.

As a result, the seat member 36b receives a force from the deformed portion 31a1. As a result, the seat member 36b is deformed against the elastic force of the seat member 36b. Further, by rotating the sheet member 36b in a state of being in contact with the deformed portion 31a1, the toner is conveyed in a state of being supported on the surface on the downstream side of the rotation. In this embodiment, the deformed portion 31a1 refers to a portion of the inner wall of the toner accommodating chamber until the sheet member 36b is separated, as shown in FIG. 5A.

Further, the toner storage chamber 31a is provided with a restoration portion 31a2 on the downstream side of the deformed portion 31a1 and on the upstream side of the opening portion 31c in the rotation of the sheet member 36b. Here, the restoration portion 31a2 is a portion for releasing the contact between the sheet member 36b and the inner wall of the toner storage chamber 31a. In this embodiment, the restoration unit 31a2 is arranged above the horizontal plane including the rotation axis of the stirring member.

Therefore, after the tip of the seat member 36b on the free end side passes through the deformed portion 31a1 as the seat member 36b rotates, the contact with the inner wall of the seat member 36b is released at the restored portion 31a2. Then, the sheet member 36b is released from the state of being deformed by the deformed portion 31a1, and is restored to the natural state (original shape) by the elastic restoring force of itself.

Due to the shape change of the sheet member 36b in the restoring direction, the toner supported and conveyed on the sheet member 36b flies toward the opening 31c against gravity. The opening 31c is located on the downstream side of the seat member 36b in the rotational direction with respect to the restored portion 31a2.

A part of the toner flying toward the opening 31c is conveyed into the developing chamber 31b. On the other hand, the toner that has not reached the inside of the developing chamber 31b falls into the toner accommodating chamber 31a, stays at the bottom of the toner accommodating chamber 31a, and returns to the original state again. By repeating this cycle, the toner is agitated and conveyed.

<Toner replenishment operation>
Next, the toner replenishment operation in this embodiment will be described.

As shown in FIG. 4, the developing unit 4 is provided with a receiving port 40 at one end on the downstream side in the attachment / detachment direction. A receiving and transporting path 41 is provided so as to communicate with the toner receiving and receiving port 40, and a receiving and transporting screw (not shown) is arranged inside. The receiving transport path 41 extends parallel to the direction of the rotation axis of the developing roller 25 and the supply roller 34.

Further, a storage chamber communication port 43 (supply port) for supplying toner to the toner storage chamber 31a is provided near the center of the longitudinal direction of the developing unit 4, and communicates the receiving transport path 41 and the toner storage chamber 16b. The toner discharged from the toner cartridge 9 reaches the toner receiving port 40 by the toner transport device 18 provided in the apparatus main body 100A. The toner received from the toner receiving port 40 is conveyed and replenished inside the toner storage chamber 16b via the storage chamber communication port 43.

More specifically, as described above, the developing unit 4 of this embodiment includes a developing frame 31.

The developing frame 31 includes a developing chamber 31b in which a developing roller 25 for carrying toner is housed, a toner storage chamber 31a located below the developing room in a posture during use and storing toner, and a developing room and a toner storing room. It is provided with an opening 31c for communicating with the above.

The toner storage chamber 31a is provided with a toner transport member 36 that transports the toner stored in the toner storage chamber to the developing room 31b.

The toner transport member 36 includes a rotatable stirring shaft 36a and an elastically deformable sheet member 36b. One end 36b1 of the sheet member 36b is fixed to the stirring shaft 36a, and the other end 36b2 is a free end.

The toner accommodating chamber 31a is provided with a deformed portion 31a1.

When the free end (36b2) of the seat member 36b that rotates with the rotational operation of the stirring shaft 36a comes into contact with the deformed portion 31a1, the seat member is flexed and elastically deformed.

The toner accommodating chamber 31a is provided with a restoring portion 31a2 at a position upstream of the opening 31c and downstream of the deformed portion 31a1 in the rotation direction X2 of the stirring shaft 36a.

The sheet member 36b (free end) in a state of being elastically deformed by the deformed portion 31a1 is released by the restoring portion 31a2 and elastically restored. As a result, the toner supported on the upper surface of the sheet member 36b is blown toward the opening 31c and supplied to the developing chamber 31b.

The toner storage chamber 31a is provided with a storage chamber communication port 43 for supplying toner to the toner storage chamber 31a from the outside.

<Mixing of toner in the toner storage chamber>
Toner is replenished from the toner cartridge 9 into the toner storage chamber 31a via the toner transfer device 18 and the storage chamber communication port 43. The replenished toner (hereinafter referred to as "new toner") is inside the toner storage chamber 31a by the rotation of the sheet member 36b together with the toner (hereinafter referred to as "old toner") that already existed in the toner storage chamber 31a before replenishment. Stir (mix) and transport.

Here, as the use of the developing unit 4 progresses and the toner circulation is repeated in the developing unit 4, the deterioration of the old toner in the toner accommodating chamber 31a progresses. Deterioration here means that the toner resin is worn or deformed by mechanical rubbing, or the external additive added to the surface is released or embedded in the resin, and the toner resin is replenished from the toner replenishment container. It refers to a phenomenon in which behavior such as charging characteristics changes with respect to new toner.

That is, in a state where the development unit 4 is used and the old toner is deteriorated, a difference in charging characteristics from the new toner occurs. If the charging characteristics of the toner are different, the amount of toner that fills the electrostatic latent image changes when the electrostatic latent image formed on the photoconductor drum 1 is visualized, and not only the bright potential but also the bright potential. Toner may fly to the dark potential. As a result, image defects such as "density unevenness" and "fog" described later will occur.

In order to suppress the occurrence of such a problem, even if there is a difference in charging characteristics between the new toner and the old toner, the new toner and the old toner are sufficiently agitated in the toner storage chamber 31a. It is important to reduce the uneven distribution of new toner in the old toner.

In the present invention, the positions of the opening 31c and the restoring portion 31a2 and the position of the accommodating chamber communication port 43 are defined as described below, thereby solving the problem with a simple configuration without providing additional members or complicated configurations. ..

Next, the relationship between the positions of the opening 31c and the restoration portion 31a2, the position of the accommodation chamber communication port 43, and the occurrence of the problem will be described in detail.

FIG. 6 is a conceptual diagram showing a region A and a region B in the developing unit according to the embodiment of the present invention.

FIG. 7A is a conceptual diagram showing the posture of the developing unit and the position of the supply port according to the embodiment of the present invention. 7 (b to d) are conceptual diagrams showing the posture of the developing unit and the position of the supply port in the comparative example with respect to the embodiment of the present invention.

First, as shown in FIG. 6, when a vertical line passing through the center of the stirring shaft 36a is drawn and divided into left and right in the posture during use, the region including the restoration portion 31a2 is referred to as region A, and the region not including the restoration portion 31a2 is referred to as region B. I will do it.

At this time, the combination of the opening 31c and the position of the storage chamber communication port 43 can be distinguished into the four patterns shown in Tables 1 and 7 (a) to (d). When the opening 31c and the accommodation chamber communication port 43 straddle between the areas A and B, if even a part of the opening 31c is included in the area B, the area B is set.

First, in this embodiment, as shown in FIG. 7A, both the opening 31c and the accommodation chamber communication port 43 are in the area B.

More specifically, in this embodiment, when viewed along the rotation axis direction X1 of the stirring shaft 36a in the posture during use, the perpendicular line G1 passing through the rotation center X0 of the stirring shaft 36a can be used as a reference. At this time, at least a part of the opening 31c and at least a part of the accommodation chamber communication port 43 are both located on one side G11 with respect to the perpendicular line G1. Further, the restoration unit 31a2 is located on the other side G12, which is a side different from the one side G11 with respect to the perpendicular line G1.

On the other hand, in Comparative Example 1, as shown in FIG. 7B, the opening 31c is in the area B, and the accommodation chamber communication port 43 is in the area A.

In Comparative Example 2, as shown in FIG. 7 (c), the opening 31c is in the area A, and the accommodation chamber communication port 43 is in the area B.

In Comparative Example 3, as shown in FIG. 7D, both the opening 31c and the accommodation chamber communication port 43 are in the region A.

First, the difference between the position of the storage chamber communication port 43 and the mixed state of the new toner and the old toner in the toner storage chamber 31a will be described.

When the storage chamber communication port 43 is in the area B as in the configuration of the present embodiment, the new toner replenished from the storage chamber communication port 43 is in the old toner staying at the bottom of the toner storage chamber 31a, or the old toner. It will be replenished to the rotation upstream side of the stirring sheet 36b. Then, the stirring sheet 36b passes through the old toner staying at the bottom of the toner storage chamber 31a by the time it reaches the restoration portion 31a due to its rotation, and during that time, it is actively mixed with the old toner and then developed. It is transported to the chamber 31b.

On the other hand, when the storage chamber communication port 43 is in the region A as in the configurations shown in Comparative Examples 1 and 3, the new toner to be replenished is agitated in the old toner staying at the bottom of the toner storage chamber 31a or from the old toner. It will be replenished to the rotation downstream side of the seat 36b.

That is, the distance from the storage chamber communication port 43 to the restoration unit 31a2 is short, and there is little chance that the old toner and the new toner are mixed. Then, the new toner reaches the restoration unit 31a2 in a state where it is not sufficiently mixed with the old toner, and is conveyed to the developing room.

Next, the difference between the position of the opening 31c and the mixed state of the new toner and the old toner in the toner storage chamber 31a will be described.

FIG. 8 is a conceptual diagram showing the circulation of toner in the developing unit according to the embodiment of the present invention.

Specifically, FIG. 8 shows a state after one of the stirring sheets 36b has passed the restoration portion 31a and the toner has been conveyed to the developing chamber 31b. It shows how the toner that has not been conveyed to the developing chamber 31b has fallen into the toner accommodating chamber 31a.

First, as in the configuration shown in this embodiment and Comparative Example 1, when the opening 31c is in the region B, the toner that has flown toward the opening 31c does not reach the developing chamber 31b and falls into the toner accommodating chamber 31a. Most of the toner to be processed will fall into the region B (see FIG. 8). Then, the dropped toner is agitated and mixed with the old toner staying at the bottom of the toner accommodating chamber 31a, and then transported to the developing chamber.

On the other hand, when the opening 31c is in the region A as in the configurations shown in Comparative Examples 2 and 3, among the toners that have flown toward the opening 31c, the toner that does not reach the developing chamber 31b and falls into the toner accommodating chamber 31a. Most of them will fall into the area A. The dropped toner is lifted by the rotation of the stirring sheet, reaches the restored portion, and flies. That is, the toner is conveyed to the developing chamber in a state where it is less likely to be mixed with the toner accumulated at the bottom of the toner accommodating chamber.

As described above, in the present embodiment, when a perpendicular line is drawn so as to pass through the center of the stirring shaft in the posture during use, the opening 31c and the accommodation chamber communication port 43 are restored as in the configuration of the present embodiment. It is arranged on a different side (area B) from. As a result, the new toner and the old toner can be sufficiently agitated and mixed in the toner accommodating chamber 31a before being conveyed to the developing chamber 31b.

Therefore, it is possible to reduce uneven distribution of toners having different chargeability in the coating on the developing roller, and it is possible to suppress the occurrence of image defects such as "fog", toner scattering and density unevenness, which will be described later.

In this embodiment, the two sets of seat members 36b are attached by shifting the attachment position on the stirring shaft 36a. As a result, the toner can be efficiently agitated in the toner accommodating chamber 31a and the toner can be efficiently transferred to the developing chamber 31b in the case where the sheet members 36b are one set.

Further, in this embodiment, the length (free length L) of the seat member 36b is longer than the shortest distance (L1) from the stirring shaft 36a to the storage chamber communication port 43.

In other words, the seat member 36a comes into contact with the accommodation chamber communication port 43 in a phase in which the seat member 36b overlaps the accommodation chamber communication port 43. As a result, the transport capacity for the new toner replenished from the storage chamber communication port 43 can be increased, and the mixing with the old toner can be efficiently performed.

<Effect verification experiment>
In order to verify the effect of this example, the experiments described below were carried out together with Comparative Examples 1, 2 and 3.

An intermittent printing durability test was performed on two sheets in an environment of normal temperature and humidity (temperature 23 ° C., humidity 60%). In this printing durability, horizontal lines with an image ratio of 1% are printed.

Further, in this experiment, the process cartridge 70 was started with 200 g of toner filled, and control was performed to replenish 10 g of toner from the toner cartridge 9 every time the toner decreased by 10 g. Then, the printing durability was performed until the amount of the process cartridge 70 used reached 100%, and the occurrence of fog was judged according to the criteria shown below.

Next, an evaluation experiment is conducted for image defects due to "fog".

The "fog" is an image defect in which the toner is slightly developed in an unexposed area that is not originally printed and appears like a background stain.

The image forming apparatus is stopped while printing a solid white image. The toner on the photoconductor drum after development and before transfer is once transferred to a transparent tape, and the tape to which the toner is attached is attached to a recording paper or the like. At the same time, a tape to which toner is not attached is also attached to the same recording paper. The optical reflectance of the tape attached to the recording paper is measured by a green filter using an optical reflectance measuring machine (TC-6DS manufactured by Tokyo Denka Co., Ltd.) and subtracted from the reflectance of the tape to which no toner is attached. The amount of reflectance of the fog was calculated and evaluated as the amount of fog. The amount of fog was measured at 3 or more points on the tape and the average value was calculated.

A: The amount of fog is less than 1.0%.
B: The amount of fog is less than 1.0 to 3.0%.
C: The amount of fog is less than 3.0 to 5.0%.
D: The amount of fog is 5.0% or more.

The evaluation results are shown in Table 2.

In the configuration of this embodiment, as a result of sufficient mixing of the new toner and the old toner in the toner storage chamber 31a, the use of the process cartridge is advanced, and the new toner is replenished in a state where the old toner is deteriorated. In that case, the occurrence of fog could be suppressed.

On the other hand, in the configuration of Comparative Example 1, since the storage chamber communication port 43 is in the area A, the new toner replenished from the storage chamber communication port 43 is conveyed to the developing room 31b without being sufficiently mixed with the old toner. .. As a result, "fog" occurred when the usage amount of the process cartridge was close to 100%.

Further, in the configuration of Comparative Example 2, since the opening 31c is in the region A, most of the toner that has not been conveyed to the developing chamber 31b and has fallen into the toner accommodating chamber 31a will fall near the restoration portion 31a2. It becomes difficult to mix with the toner staying at the bottom of the toner storage chamber 31a. As a result, "fog" occurred when the amount of the process cartridge used increased as in Comparative Example 1.

Further, in the configuration of Comparative Example 3, since both the storage chamber communication port 43 and the opening 31c are in the region A, the toner is mixed in the toner storage chamber 31a more than the configurations of Comparative Example 1 and Comparative Example 2. It will be insufficient. As a result, "fog" occurred even when the amount of the process cartridge used was relatively low.

As described above, there is a relationship between the arrangement of the storage chamber communication port 43 and the opening 31c and the toner mixed state in the toner storage chamber 31a, and by adopting the configuration of this embodiment, additional members and complicated configurations can be added. It was possible to suppress the occurrence of "fog" without providing it.

According to the present invention, it is possible to suppress the occurrence of "fog" due to the difference in the charging ability of the toner when the toner is replenished with a simple configuration.

The configuration of the present invention can be summarized as follows.

(1) The developing apparatus (4) of the present invention is
A developing chamber (31b) containing a developing agent carrier (25) carrying a developing agent, a developing agent accommodating chamber (31a) located below the developing chamber in the posture during use and accommodating the developing agent, and developing. A developing frame (31) comprising a communication port (31c) for communicating the chamber and the developing agent storage chamber, and a developing frame (31).
It has a transport member provided in the developer storage chamber (31a) and transports the developer stored in the developer storage chamber to the developing chamber (31b).

The transport member (36) includes a rotatable rotating shaft portion (36a) and a seat portion (36b) in which one end (36b1) is fixed to the rotating shaft portion and the other end (36b2) becomes a free end and is elastically deformable. , Equipped with.

In addition, the developing device (4)
By contacting the free end (36b2) of the sheet portion (36b) provided in the developer accommodating chamber (31a) and rotating with the rotational operation of the rotating shaft portion (36a), the sheet portion is flexed and elastic. The deformed part (31a1) to be deformed and
With the restoring portion (31a2) provided in the developer accommodating chamber (31a) at a position upstream of the communication port (31c) and downstream of the deformed portion (31a1) in the rotation direction (X2) of the rotating shaft portion (36a). Further has.

The restoring portion (31a2) releases the sheet portion (36b) elastically deformed by the deforming portion (31Aa1) and restores the sheet portion (36b) so that the developer supported on the sheet portion is directed toward the communication port (31c). It is configured to fly.

Further, the developer accommodating chamber (31a) is provided with a replenishment port (43) for replenishing the developer from the outside to the developer accommodating chamber.
When viewed along the rotation axis direction (X1) of the rotation shaft portion (36a) in the posture during use, when the vertical line (G1) passing through the rotation center (X0) of the rotation shaft portion (36a) is used as a reference.
At least a part of the communication port (31c) and at least a part of the supply port (43) are both located on one side (G11) with respect to the vertical line (G1).
The restoration unit (31a2) is located on the opposite side (G12) of the perpendicular line (G1).

(2) In the developing apparatus of the present invention
The seat portion (36b) may have a free length (L) longer than the shortest distance (L1) from the rotation center (X0) of the rotation shaft portion (36a) to the supply port (43).

(3) In the developing apparatus of the present invention
In the posture during use, the highest position (P11) of the supply port (43) may be located below the lowest position (P21) of the restoration portion (31a2). In the present invention, the lowest position of the restored portion (31a2) is such that the free end (36b2) of the sheet portion (36b) comes into contact with the inner wall surface of the developing frame constituting the restored portion (31a2) when rotating. This is the position where the state begins to change from the state to the state of being separated.

(4) In the developing apparatus of the present invention
In the posture during use, the highest position (P11) of the supply port (43) may be located below the highest position (P31) of the deformed portion (31a1). The highest position of the deformed portion (31a1) is the position where the distance of the rotating shaft portion (36a) to the rotation center X0 is the shortest among the inner wall surfaces of the developing frame constituting the deformed portion (31a1). ..

(5) In the developing apparatus of the present invention
The seat portion (36b) includes a first seat portion (36b3) and a second seat portion (36b4).
The first seat portion (36b3) and the second seat portion (36b4) may be attached to the rotation shaft portion (36a) at different positions (X21, X22) in the rotation direction (X2).

(6) In the developing apparatus of the present invention
The first seat portion (36b3) and the second seat portion (36b4) may be fixed to both sides (36a1, 36a2) of the rotation shaft portion (36a) with the rotation center (X0) interposed therebetween.
The first seat portion (36b3) and the second seat portion (36b4) may be arranged so that their free ends (36b2) extend in opposite directions (D1, D2).

(7) In the developing apparatus of the present invention
In the posture during use, the highest position (P11) of the supply port (43) is located above the surface (LV) of the developer stored in the developer storage chamber (31a) in the unused state. You may do so.

(8) In the developing apparatus of the present invention
The developing chamber (31b) may be provided with a supply member (34) that comes into contact with the developing agent carrier (25) and supplies the developing agent to the developing agent carrier.

(9) In the developing apparatus of the present invention
The developer may be a one-component non-magnetic developer.

(10) In the developing apparatus of the present invention
The developing device (4) may be made removable from the image forming device (100) that forms an image.

(11) The process cartridge (70) of the present invention is
An image carrier (1) that supports a developer image and
It includes the developing device (4) and is removable from the image forming device (100).

(12) In the process cartridge of the present invention
The developer carrier (25) may recover the developer remaining on the pre-carrier (1) after the developer image has been transferred from the image carrier (1).

(13) The image forming apparatus (100) of the present invention is
With at least one of the developing apparatus (4) or the process cartridge (70),
A transfer member (58) is provided.

4 Development unit (developer)
25 Development roller (developer carrier)
31 Develop frame 31a Toner storage room (Developer storage room)
31a1 Deformation part 31a2 Restoration part 31b Development room 31c Opening (communication port)
36 Toner Conveying Member (Conveying Member)
36a Stirring shaft (rotating shaft)
36b Seat member (seat part)
36b1 One end (fixed end)
36b2 The other end (free end)
43 Containment room communication port (supply port)
G1 vertical line G11 (relative to vertical line) one side G12 (relative to vertical line) other side X0 rotation center X1 rotation axis direction

Claims (13)

A developing room in which a developing agent carrier carrying a developing agent is housed, a developing agent storage room located below the developing room in a posture during use and storing the developing agent, and the developing room and the developing agent storage room. With a developing frame body, which has a communication port for communicating with
A transport member provided in the developing agent accommodating chamber and conveying the developing agent contained in the developing agent accommodating chamber to the developing chamber, the rotatable rotating shaft portion and one end fixed to the rotating shaft portion. A transport member including a sheet portion having a free end at the other end and elastically deformable.
A deformed portion provided in the developer accommodating chamber and abutting with the free end of the sheet portion that rotates with the rotational operation of the rotating shaft portion to bend and elastically deform the sheet portion.
The sheet portion provided in the developer accommodating chamber at a position upstream of the communication port and downstream of the deformed portion in the rotation direction of the rotating shaft portion, and elastically deformed by the deformed portion. A restoration unit that allows the developer carried on the sheet portion to fly toward the communication port by releasing and restoring the processing unit, and a restoration unit.
It is a developing device having
The developer accommodating chamber is provided with a supply port for replenishing the developer from the outside to the developer accommodating chamber.
When viewed along the direction of the rotation axis of the rotation shaft in the posture during use, when the vertical line passing through the rotation center of the rotation shaft is used as a reference,
At least a part of the communication port and at least a part of the supply port are both located on one side of the vertical line.
The developing device is characterized in that the restoration unit is located on the opposite side of the perpendicular line. The developing apparatus according to claim 1, wherein the sheet portion has a free length longer than the shortest distance from the rotation center of the rotating shaft portion to the supply port. The developing apparatus according to claim 1 or 2, wherein the highest position of the supply port is located below the lowest position of the restoration portion in the posture during use. The developing apparatus according to any one of claims 1 to 3, wherein the highest position of the supply port is located below the highest position of the deformed portion in the posture during use. The seat portion includes a first seat portion and a second seat portion.
The invention according to any one of claims 1 to 4, wherein the first seat portion and the second seat portion are attached to the rotation shaft portion at different positions in the rotation direction. Development equipment. The first seat portion and the second seat portion are fixed to both sides of the rotation shaft portion with the rotation center interposed therebetween.
The developing apparatus according to claim 5, wherein the first sheet portion and the second sheet portion are arranged so that their free ends extend in opposite directions. Claims 1 to 1, characterized in that, in the posture during use, the highest position of the supply port is located above the surface of the developer contained in the developer storage chamber in an unused state. 6. The developing apparatus according to any one of 6. The one according to any one of claims 1 to 7, wherein the developing chamber is provided with a supply member that comes into contact with the developing agent carrier and supplies the developing agent to the developing agent carrier. Develop device. The developing apparatus according to any one of claims 1 to 8, wherein the developing agent is a one-component non-magnetic developing agent. The developing device according to any one of claims 1 to 9, wherein the developing device is detachable from an image forming device that forms an image. An image carrier that supports a developer image and
A process cartridge comprising the developing apparatus according to any one of claims 1 to 10, which is removable from and detachable from an image forming apparatus. The process cartridge according to claim 11, wherein the developer carrier recovers the developer remaining on the image carrier after the developer image is transferred from the image carrier. At least one of the developing apparatus according to any one of claims 1 to 10 or the process cartridge according to claim 11 or 12.
Transfer member and
An image forming apparatus comprising.

Images