JP2023012062A - developing device - Google Patents

Abstract

To provide a configuration that can reduce load torque applied to a drive train that transmits drive to a first developing sleeve 44 and a second developing sleeve 45 and a plurality of conveying screws.SOLUTION: A developing device has a first developing sleeve 44, a second developing sleeve 45, a first conveying screw 42, a second conveying screw 43, and a third conveying screw 47. A first drive train 48 receives a first driving force from a driving source in an image forming apparatus body and transmits the first driving force to the first developing sleeve 44, second developing sleeve 45, and third conveying screw 47. A second drive train 49 receives a second driving force from the driving source in the image forming apparatus body and transmits the second driving force to the first conveying screw 42 and second conveying screw 43 separately from the first drive train 48.SELECTED DRAWING: Figure 5

Description

The present invention relates to a developing device that develops an electrostatic latent image formed on an image carrier with a developer.

The developing device carries and conveys the developer in the developing container by the developer carrier, and develops the electrostatic latent image formed on the image carrier with the developer. In such a developing device, in addition to a first conveying member and a second conveying member arranged respectively in a first chamber and a second chamber partitioned by a partition in a developing container and conveying the developer in directions opposite to each other, and a third conveying member for conveying the developer.

In order to drive the developer carrier and each transport member, a drive transmission section for transmitting the drive to the developer carrier and a drive transmission section for transmitting the drive to the first to third transport members are separated. A configuration has been proposed (Patent Document 1).

JP 2012-18302 A

In the developing device, the developer tends to deteriorate due to the temperature rise in the developing device and the friction with the conveying member, and the deteriorated developer has effects such as aggregation and decreased fluidity. As a result, the load (conveyance resistance) with which the conveying member agitates and conveys the developer increases, and the rotational torque of the conveying member increases. In recent years, due to the increase in speed, the rotation speed of the image carrier and the developer carrier has increased, and the speed at which the developer is consumed has increased accordingly. tend to increase in volume. In such a case, the developer in the developing device tends to be condensed, the load of the conveying member agitating and conveying the developer increases, and the rotational torque of the conveying member increases.

Here, when the driving force is transmitted from the driving source to the developer bearing member and the plurality of conveying members by one driving transmission portion, the load torque of the driving member constituting one driving transmission portion increases as the rotational torque of the conveying member increases. increase, and the service life of members involved in drive transmission is shortened.

Further, even if the drive transmission portion is divided into two parts as described in Patent Document 1, there are cases where the load torque of the drive transmission portion cannot be sufficiently reduced depending on the member driven by each drive transmission portion. That is, in the case of the configuration described in Japanese Patent Application Laid-Open No. 2002-200311, the drive transmission portion to the developer bearing member and the drive transmission to the three conveying members are separated. As a result, the rotational torque of the conveying member that conveys the developer tends to increase. Therefore, when three conveying members whose rotational torque tends to increase are driven by one drive transmission unit, the load torque cannot be sufficiently reduced.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a configuration capable of reducing load torque applied to a drive transmission section that transmits drive to a developer carrier and a plurality of conveying members.

A developing device of the present invention is a developing device which is arranged in an image forming apparatus main body and develops an electrostatic latent image formed on an image carrier with a developer, wherein the electrostatic latent image formed on the image carrier is developed. A second chamber in which the developer circulates between a developer bearing member that carries and conveys the developer for developing an image, a first chamber that supplies the developer to the developer bearing member, and the first chamber. and a partition partitioning the first chamber and the second chamber, the developing container containing the developer, and allowing the developer to move from the second chamber to the first chamber. a first communication portion; a second communication portion that allows the developer to move from the first chamber to the second chamber; a first conveying member for conveying the developer in a first direction toward the two communicating portions; and a second conveying member disposed in the second chamber for conveying the developer in a second direction from the second communicating portion to the first communicating portion. a third conveying member arranged below the developer bearing member for collecting the developer from the developer bearing member and stirring and conveying the developer; and receiving a first driving force from a driving source in the image forming apparatus main body. a first driving force transmitting portion for transmitting the first driving force to the developer bearing member and the third conveying member; and a second drive transmission section for transmitting the second driving force separately from the first drive transmission section to the second conveying member.

Further, the developing device of the present invention is a developing device which is arranged in an image forming apparatus body and develops an electrostatic latent image formed on an image carrier with a developer, wherein the electrostatic latent image formed on the image carrier is developed. a first developer carrier for carrying and conveying a developer for developing an electrostatic latent image; and a predetermined developer carrier for developing the electrostatic latent image formed on the image carrier. Development is performed between a second developer bearing member arranged in parallel with a gap therebetween for carrying and conveying the developer, a first chamber supplying the developer to the first developer bearing member, and the first chamber. a developer container having a second chamber in which a developer circulates and a partition wall separating the first chamber and the second chamber; a first communication portion that allows the developer to move from the first chamber to the second chamber; a second communication portion that allows the developer to move from the first chamber to the second chamber; a first conveying member for conveying the developer in a first direction from the first communicating portion to the second communicating portion; a second conveying member that conveys the developer in a direction; a third conveying member that is disposed below the second developer carrier and collects the developer from the second developer carrier and agitates and conveys the developer; and the image forming apparatus main body. a first drive transmission section that receives a first driving force from a driving source inside and transmits the first driving force to the first developer carrier, the second developer carrier, and the third conveying member; a second drive transmission that receives a second drive force from a drive source in the main body of the image forming apparatus and transmits the second drive force to the first conveying member and the second conveying member separately from the first drive transmission section; and a part.

Further, the developing device of the present invention is a developing device which is arranged in an image forming apparatus body and develops an electrostatic latent image formed on an image carrier with a developer, wherein the electrostatic latent image formed on the image carrier is developed. a first developer carrier for carrying and conveying a developer for developing an electrostatic latent image; and a predetermined developer carrier for developing the electrostatic latent image formed on the image carrier. Development is performed between a second developer bearing member arranged in parallel with a gap therebetween for carrying and conveying the developer, a first chamber supplying the developer to the first developer bearing member, and the first chamber. a developer container having a second chamber in which a developer circulates and a partition wall separating the first chamber and the second chamber; a first communication portion that allows the developer to move from the first chamber to the second chamber; a second communication portion that allows the developer to move from the first chamber to the second chamber; a first conveying member for conveying the developer in a first direction from the first communicating portion to the second communicating portion; a second conveying member that conveys the developer in a direction; a third conveying member that is disposed below the second developer carrier and collects the developer from the second developer carrier and agitates and conveys the developer; and the image forming apparatus main body. receiving a first driving force from a driving source inside, and transmitting the first driving force to the first developer bearing member, the second developer bearing member, the first conveying member, and the third conveying member; and a second drive transmission that receives a second drive force from a drive source in the image forming apparatus main body and transmits the second drive force to the second conveying member separately from the first drive transmission portion. and a part.

According to the present invention, it is possible to reduce the load torque applied to the drive transmission section that transmits the drive to the developer carrying member and the plurality of conveying members.

1 is a cross-sectional view of a schematic configuration of an image forming apparatus according to a first embodiment; FIG. 1 is a cross-sectional view of a schematic configuration of a developing device according to a first embodiment; FIG. 1 is a longitudinal sectional view of a schematic configuration of a developing device according to a first embodiment; FIG. 1 is a schematic perspective view showing a partially cut developing device according to a first embodiment; FIG. FIG. 4 is a schematic diagram showing the configuration of a drive transmission unit to the developing device according to the first embodiment; FIG. 2 is a perspective view showing the configuration of a drive transmission section to the developing device according to the first embodiment; FIG. 5 is a schematic diagram showing the configuration of a drive transmission unit to a developing device according to a second embodiment; FIG. 10 is a cross-sectional view of a schematic configuration of a developing device according to a third embodiment;

<First embodiment>
A first embodiment will be described with reference to FIGS. 1 to 6. FIG. First, a schematic configuration of the image forming apparatus of this embodiment will be described.

[Image forming apparatus]
FIG. 1 is a schematic sectional view showing an image forming apparatus 100 of this embodiment. The image forming apparatus 100 is an electrophotographic full-color laser printer. In the image forming apparatus 100 of the present embodiment, first, second, third, and fourth image forming units Py, Pm, Pc, and Pb arranged side by side inside the main body 101 of the image forming apparatus form four different colors. A color toner image is formed through the processes of charging, exposure, development and transfer. The control unit 19 as control means includes a CPU and memories such as ROM and RAM, and controls the configuration of each unit of the image forming apparatus 100 . When receiving a print command signal output from an external interface such as a host computer, the control unit 19 sequentially operates the image forming units Py, Pm, Pc and Pb according to the image forming control sequence stored in the memory.

In each image forming portion Py, Pm, Pc, Pb, a photosensitive drum 1 as an image bearing member is rotated at a predetermined peripheral speed (process speed). The photosensitive drum 1 is a cylindrical photosensitive member. Then, the intermediate transfer belt 7 stretched over the driving roller 6a, the driven roller 6b, and the tension roller 6c so as to straddle the photosensitive drums 1 of the image forming portions Py, Pm, Pc, and Pb is transferred to each photosensitive drum by the driving roller 6a. It is rotated at a rotational peripheral speed of 1 and a corresponding peripheral speed.

In the image forming portion Py for yellow, which is the first color, the outer peripheral surface (surface) of the photosensitive drum 1 is uniformly charged to a predetermined polarity and potential by the charger 2 . Next, the exposure device 3 scans and exposes the charged surface of the photosensitive drum 1 with laser light generated based on image information from an external device. As a result, an electrostatic latent image corresponding to the image information is formed on the charged surface of the photosensitive drum 1 . Then, the latent image is developed with a yellow toner (developer) by the developing device 4 to form a yellow toner image (development) on the surface of the photosensitive drum 1 . Similar charging, exposure, and development steps are also performed in the image forming portion Pm for the second color magenta, the image forming portion Pc for the third color cyan, and the image forming portion Pb for the fourth color black.

A toner image of each color formed on the surface of the photosensitive drum 1 in each of the image forming portions Py, Pm, Pc, and Pb is transferred to a primary transfer roller (transfer member) 8 arranged to face the photosensitive drum 1 with the intermediate transfer belt 7 interposed therebetween. are sequentially superimposed and transferred onto the outer peripheral surface (surface) of the intermediate transfer belt 7 by . As a result, a full-color toner image is formed on the intermediate transfer belt 7 surface. After the transfer of the toner image, the photosensitive drum 1 is used for the next image formation after the transfer residual toner remaining on the surface of the photosensitive drum 1 is removed by the drum cleaner 5 .

On the other hand, the recording material P is conveyed from the feeding cassette 10 to the registration rollers 13 through the conveying path 12a by the feeding rollers 11. As shown in FIG. The recording material P is, for example, a sheet material such as paper or a plastic sheet. Next, the recording material P is conveyed by the registration roller 13 to the secondary transfer nip portion Tn between the intermediate transfer belt 7 and the secondary transfer roller 14 . The recording material P is nipped and conveyed at the secondary transfer nip portion Tn, and the toner image on the surface of the intermediate transfer belt 7 is transferred onto the recording material P by the secondary transfer roller 14 in this conveying process. After the transfer of the toner image, the intermediate transfer belt 7 is used for the next image formation after the transfer residual toner remaining on the surface of the intermediate transfer belt 7 is removed by the belt cleaner 9 .

The recording material P bearing an unfixed toner image is introduced into the nip portion of the fixing device 15 with the image bearing surface facing upward. The recording material P is nipped and conveyed in the nip portion of the fixing device 15 so that the toner image is heat-fixed on the recording material P. As shown in FIG. When an image is formed on only one side of the recording material P, the recording material P discharged from the fixing device 15 is guided to the discharge roller 17 by the switching member 16, and is provided on the side surface of the image forming apparatus main body 101 by the discharge roller 17. It is discharged onto the discharge tray 18 where it is located.

When images are formed on both sides of the recording material P, the recording material P discharged from the fixing device 15 is guided by the switching member 16 to the reverse conveying path 12b below. In the reversing conveying path 12b, when the trailing edge of the recording material P reaches the reversing point Rp, the recording material P is switched back so that the image carrying surface faces upward and is sent to the double-sided conveying path 12c in this state. The recording material P is transported to the registration rollers 13 through the transport path 12a on the double-sided transport path 12c. The recording material P is conveyed to the secondary transfer nip portion Tn by the registration rollers 13, and is nipped and conveyed at the secondary transfer nip portion Tn. In this conveying process, the toner on the surface of the intermediate transfer belt 7 is transferred onto the recording material P by the secondary transfer roller 14 . The recording material P bearing an unfixed toner image is introduced into the nip portion of the fixing device 15 with the image bearing surface facing upward. The recording material P is nipped and conveyed in the nip portion of the fixing device 15 so that the toner image is heat-fixed on the recording material P. As shown in FIG. The recording material P ejected from the fixing device 15 is guided to the ejection roller 17 by the switching member 16 and ejected onto the ejection tray 18 by the ejection roller 17 .

[Developing device]
The developing device 4 of this embodiment will be described with reference to FIGS. 2 to 4. FIG. FIG. 2 is a cross-sectional view of the developing device 4 cut in a direction orthogonal to the rotational axis direction of the first developing sleeve 44 and the second developing sleeve 45. As shown in FIG. FIG. 3 is a cross-sectional view taken along the rotation axis direction of the first developing sleeve 44 and the second developing sleeve 45 at the first conveying screw 42 and the second conveying screw 43 . FIG. 4 is a perspective view showing an outline of the appearance of the developing device 4. As shown in FIG.

The developing device 4 has a developer container 41 containing developer. The developer of this embodiment is a so-called two-component developer containing non-magnetic toner and a magnetic carrier. The developing container 41 rotatably supports a first developing sleeve 44 as a first developer carrier and a second developing sleeve 45 as a developer carrier and a second developer carrier. A first developing sleeve 44 and a second developing sleeve 45 are arranged parallel to the rotation axis direction of the photosensitive drum 1 and develop the electrostatic latent image on the surface of the photosensitive drum 1 with developer. The second developing sleeve 45 is positioned below the first developing sleeve 44 and arranged in parallel with the first developing sleeve 44 with a predetermined gap therebetween.

Further, the developer container 41 is provided with a regulating blade 44 a that regulates the layer thickness of the developer carried on the first developing sleeve 44 . The first developing sleeve 44 carries developer supplied from a later-described developing chamber 41a on its surface and conveys it. The second developing sleeve 45 is provided below the first developing sleeve 44, carries the developer transferred from the first developing sleeve 44 on its surface, and conveys the same. The first developing sleeve 44 and the second developing sleeve 45 are each formed in a cylindrical shape, and a magnet is non-rotatably arranged inside. The first developing sleeve 44 and the second developing sleeve 45 are rotationally driven in the directions of the arrows shown in FIG. 2, and carry and convey the developer by the magnetic attraction force of magnets.

The developing container 41 is positioned below the developing chamber 41a, an upper developing chamber (developer transport path) 41a as a first chamber, and a stirring chamber ( developer transport path) 41b. The developing chamber 41 a is a functional chamber that supplies developer to the first developing sleeve 44 . The agitating chamber 41b contains the recovered developer recovered from the second developing sleeve 45, the surplus developer not supplied to the first developing sleeve 44 in the developing chamber 41a, and the replenished developer supplied from the outside of the developing device 4. It is a functional room that receives and stirs the

A first conveying screw 42 as a first conveying member and a second conveying screw 43 as a second conveying member are provided in the developing chamber 41a and the stirring chamber 41b, respectively. The first conveying screw 42 and the second conveying screw 43 each have spiral blades on a rotating shaft arranged substantially parallel to the rotational axis direction (longitudinal direction) of the first developing sleeve 44 and the second developing sleeve 45. It is a screw member provided.

Further, as shown in FIG. 3, at both ends in the longitudinal direction of the partition wall 41c, there are provided first communicating portions (developer conveying paths) serving as transfer portions (developer conveying paths) for mutually conveying the developer between the developing chamber 41a and the stirring chamber 41b. A portion 41d and a second communication portion 41e are provided. The first communication portion 41d has an opening that allows the developer to move from the stirring chamber 41b to the developing chamber 41a. The second communicating portion 41e has an opening that allows the developer to move from the developing chamber 41a to the stirring chamber 41b.

The first conveying screw 42 is arranged to face the first developing sleeve 44, and rotates to agitate and convey the developer in a first direction from the first communicating portion 41d to the second communicating portion 41e. 44 is supplied with developer. The second conveying screw 43 rotates so as to agitate and convey the developer in a second direction from the second communicating portion 41e to the first communicating portion 41d. The second conveying screw 43 is arranged below the first conveying screw 42 with respect to the direction of gravity, and the second direction is opposite to the first direction. The rotation of the first conveying screw 42 and the second conveying screw 43 causes the developer in the developer container 41 to circulate while being agitated and conveyed.

The developing device 4 is provided with a collection member 46 that is disposed below the second developing sleeve 45 so as to face it and that is substantially parallel to the rotation axis direction of the second developing sleeve 45 . The collecting member 46 is provided with a predetermined distance from the second developing sleeve 45 , and a potential difference is formed between the collecting member 46 and the second developing sleeve 45 so that normally charged toner moves from the second developing sleeve 45 to the collecting member 46 . do. As a result, the toner floating between the recovery member 46 and the second developing sleeve 45 is recovered to the recovery member 46 side. That is, the collecting member 46 collects the developer separated from the second developing sleeve 45 (on the developer carrier, on the second developer carrier) after the electrostatic latent image formed on the photosensitive drum 1 is developed. of toner is collected. The collecting member 46 is a cylindrical member and rotates together with the second developing sleeve 45 .

A modification may be made in which a potential difference is formed between the collecting member 46 and the second developing sleeve 45 such that the normally charged toner moves from the collecting member 46 to the second developing sleeve 45 . In this modification, the toner floating between the collecting member 46 and the second developing sleeve 45 is collected to the second developing sleeve 45 side.

Further, the developing device 4 is adjacent to a collecting member 46 and collects the undeveloped developer in the second developing sleeve 45 . A third conveying member for conveying and a third conveying screw 47 as a stirring member are provided. That is, the third conveying screw 47 is arranged below the second developing sleeve 45, collects the developer from the second developing sleeve 45, and agitates and conveys the developer. Such a third conveying screw 47 is a screw member having helical blades on a rotating shaft arranged substantially parallel to the rotating axis direction of the first developing sleeve 44 and the second developing sleeve 45 .

In such a developing device 4, the first developing sleeve 44 rotates in the direction of the arrow (clockwise) in FIG. It carries a two-component developer with a regulated layer thickness. Then, it is conveyed to a development area A1 facing the photosensitive drum 1, and a developer is supplied to the electrostatic latent image formed on the photosensitive drum 1 to develop the latent image. The photosensitive drum 1 rotates in the direction of the arrow (counterclockwise) in FIG.

On the other hand, the second developing sleeve 45 rotates in the direction of the arrow (clockwise) in FIG. 2 during development, and the developer is transferred from the surface of the first developing sleeve 44 that has passed through the developing area A1. The developer transferred to the second developing sleeve 45 is conveyed to the developing area A2 downstream of the developing area A1 in the rotational direction of the photosensitive drum 1, and is again developed into the electrostatic latent image formed on the photosensitive drum 1. A developer is supplied to develop the latent image. After that, the developer that has contributed to the development is separated from the second developing sleeve 45 and collected in the stirring chamber 41 b , conveyed by the third conveying screw 47 and transferred to the second conveying screw 43 .

[Driving Configuration of Developing Device]
Next, the driving structure of the developing device 4 will be described with reference to FIGS. 5 and 6. FIG. The developing device 4 receives driving force from a driving source (motor) in the main body of the image forming apparatus, and is driven by a first developing sleeve 44, a second developing sleeve 45, a first conveying screw 42, a second conveying screw 43, a third conveying screw. Screw 47 rotates. At this time, driving of the developing device 4 is transmitted from two different driving sources to the first driving train 48 and the second driving train 49, respectively. Specifically, as shown in FIG. 5 , drive is input to the first input gear 48 a of the first drive train 48 from the first motor 102 as the first drive source provided in the image forming apparatus main body 101 . Further, drive is input to the second input gear 49 a of the second drive train 49 from the second motor 103 as the second drive source provided in the image forming apparatus main body 101 .

The drive input to the first input gear 48a and the second input gear 49a may be input from one motor via a clutch. By switching the connection and disconnection of the power with a clutch, the motors may be driven independently or simultaneously. That is, as long as the first drive train 48 and the second drive train 49 can be driven independently of each other, they may be driven by separate motors or may be driven by one motor through a clutch. good.

A first drive train 48 as a first drive transmission section is a gear train having a plurality of gears, and has a first input gear 48a, a first developing gear 48b, a second developing gear 48c, and an agitating gear 48d. A first input gear 48a as a first input section receives a first driving force from a first motor 102 in the main body of the image forming apparatus. The first input gear 48a includes a first development gear 48b as a first development drive member connected to the first development sleeve 44, and a second development gear 48c as a second development drive member connected to the second development sleeve 45. to transmit the first driving force to. A stirring gear 48d as a stirring driving member connected to the third conveying screw 47 receives the first driving force via the second developing gear 48c. That is, in this embodiment, the first drive train 48 receives the first driving force from the first motor 102 and applies the first driving force to the first developing sleeve 44 , the second developing sleeve 45 and the third conveying screw 47 . introduce.

On the other hand, the second drive train 49 as a second drive transmission section is a gear train having a plurality of gears, and has a second input gear 49a, intermediate gears 49b and 49c, and a carrier gear 49d. The second drive train 49 receives a second driving force from a second motor 103 different from the first motor 102 that transmits driving power to the first drive train 48 . A second driving force from the second motor 103 is transmitted to a second input gear 49 a as a second input portion connected to the first conveying screw 42 . The second driving force input to the second input gear 49a is transmitted to the conveying gear 49d as a conveying driving member connected to the second conveying screw 43 via intermediate gears 49b and 49c as intermediate driving members. . That is, in the present embodiment, the second drive train 49 receives the second driving force from the second motor 103 and provides the second driving force to the first conveying screw 42 and the second conveying screw 43 separately from the first drive train 48 . transmit power.

Thereby, the first drive train 48 rotates the first developing sleeve 44 , the second developing sleeve 45 and the third conveying screw 47 , and the second driving train 49 rotates the first conveying screw 42 and the second conveying screw 43 . to rotate. In addition, since the first motor 102 that inputs drive to the first drive train 48 and the second motor 103 that inputs drive to the second drive train 49 are separate, the first developing sleeve 44 and the second developing sleeve 45 are driven. And the third conveying screw 47, the first conveying screw 42 and the second conveying screw 43 can be driven independently of each other. In the present embodiment, each drive member constituting the first drive train 48 and the second drive train 49 is formed of gears, but the first drive train 48 and the second drive train 49 are composed of pulleys, belts, and the like. Alternatively, it may be constructed by combining another driving member with a gear.

In general, due to deterioration of the developer and an increase in the amount of developer contained in the developing device 4, the first developing sleeve 44, the second developing sleeve 45, the third conveying screw 47, the first conveying screw 42, and the second developing sleeve 44 through which the developer passes. The load torque of the conveying screw 43 increases. In particular, when a plurality of conveying members are arranged vertically as in the present embodiment, the flow of the developer slows down in the area where the developer is conveyed against the direction of gravity, and the developer tends to clog. rotational torque increases.

If a single drive train were used to transmit the driving force of these constituent members to which the load torque increases, the load torque would be concentrated on the driving member that transmits the driving force, and the life of the driving member would be shortened. Therefore, in the present embodiment, by dividing the drive train as described above, the load torque applied to each drive member can be reduced more than when a single drive train is used.

Here, in the present embodiment, in the first drive train 48, the first developing sleeve 44, the second developing sleeve 45, and the third conveying screw 47 are arranged in the same drive train. As a result, the third conveying screw 47 is driven at the same time when performing the refresh operation of removing the developer remaining on the surfaces of the first developing sleeve 44 and the second developing sleeve 45 to refresh the developing sleeve 44, thereby efficiently performing the second developing sleeve 44 and the second developing sleeve 45. The developer on the surfaces of the first developing sleeve 44 and the second developing sleeve 45 can be collected. At this time, since the first conveying screw 42 and the second conveying screw 43 are driven by the second drive train 49 having a different drive source, the load torque is reduced when the first drive train 48 is driven alone. The developer on the surfaces of the first developing sleeve 44 and the second developing sleeve 45 can be refreshed.

Furthermore, in the present embodiment, the second drive train 49 is configured so that the first conveying screw 42 and the second conveying screw 43 can be driven independently. The first conveying screw 42 and the second conveying screw 43 have the function of circulating the developer inside the developing device 4 . Therefore, when the used developer in the developing device 4 is discharged to the outside, the developer in the developing device 4 is circulated by driving the second drive train 49 alone, and the developer is efficiently discharged to the outside of the developing device 4. The developer can be discharged.

Similarly, when the developer is supplied from the outside of the developing device 4 , the second drive train 49 is driven alone to circulate the developer in the developing device 4 and efficiently develop the entire developing device 4 . drug can be distributed. Thus, the function of driving the second drive train 49 independently is to stop the first developing sleeve 44 and the second developing sleeve 45 while reducing the load torque. 45 can be suppressed, which is effective.

As described above, in the present embodiment, the first drive train 48 is the first developing sleeve 44, the second developing sleeve 45, and the third conveying screw 47, and the second drive train 49 is the first conveying screw 42 and the second The conveying screw 43 can be driven independently. In addition, the drive trains are divided according to the functions of the first drive train 48 for collecting the developer and the second drive train 49 for the circulation of the developer. As a result, the load torque applied to the drive member involved in drive transmission can be reduced. At the same time, the first developing sleeve 44 , the second developing sleeve 45 , and the third conveying screw 47 can be independently driven to rotate when executing the refresh operation, so that the surface of the second developing sleeve 45 can be efficiently rotated. The developer can be collected. Furthermore, when executing the operation of circulating the developer inside the developing device 4 or the operation of discharging the developer, the first conveying screw 42 and the second conveying screw 43 can be driven to rotate independently. With the first developing sleeve 44 and the second developing sleeve 45 stopped, the developer inside the developing device 4 can be efficiently discharged, and the developer can be distributed inside the developing device 4 . In addition, consumption of the first developing sleeve 44 and the second developing sleeve 45 can be suppressed.

<Second embodiment>
A second embodiment will be described using FIG. 7 while referring to FIGS. 1 to 4. FIG. This embodiment differs from the first embodiment in terms of the members that transmit drive by two drive transmission members. Since other configurations and actions are the same as those of the above-described first embodiment, the same configurations are denoted by the same reference numerals, and explanations and illustrations are omitted or simplified. The description will focus on the parts.

As shown in FIG. 7, in the developing device 4A of this embodiment as well, driving is transmitted from two different drive sources to the first drive train 482 and the second drive train 492, respectively, as in the first embodiment. That is, drive is input to the first input gear 482 a of the first drive train 482 from the first motor 102 as the first drive source in the image forming apparatus main body. Further, drive is input to the second input gear 492 a of the second drive train 492 from the second motor 103 as the second drive source provided in the image forming apparatus main body 101 .

A first drive train 482 as a first drive transmission section is a gear train having a plurality of gears, and includes a first input gear 482a, a first developing gear 482b, a second developing gear 482c, a stirring gear 482d, and a first conveying gear. 482e. A first input gear 482a as a first input section receives a first driving force from a first motor 102 in the image forming apparatus main body. The first input gear 482a includes a first development gear 482b as a first development drive member connected to the first development sleeve 44 and a second development gear 482c as a second development drive member connected to the second development sleeve 45. , the first driving force is transmitted to the first transport gear 482e as a first transport drive member connected to the first transport screw 42. As shown in FIG. A stirring gear 482d as a stirring driving member connected to the third conveying screw 47 receives the first driving force via the second developing gear 48c. That is, in this embodiment, the first drive train 48 receives the first driving force from the first motor 102 , and the first developing sleeve 44 , the second developing sleeve 45 , the first conveying screw 42 and the third conveying screw 47 . It transmits the first driving force.

On the other hand, the second drive train 492 as a second drive transmission section is a gear train having a plurality of gears, and has a second input gear 492a and a second transport gear 492d. The second drive train 49 receives a second driving force from a second motor 103 different from the first motor 102 that transmits driving power to the first drive train 48 . A second driving force from the second motor 103 is transmitted to a second input gear 492a as a second input section. The second driving force input to the second input gear 492 a is transmitted to the second conveying gear 492 d as a second conveying drive member connected to the second conveying screw 43 . That is, in this embodiment, the second drive train 49 receives the second drive force from the second motor 103 and transmits the second drive force to the second conveying screw 43 separately from the first drive train 48 .

Thereby, the first drive train 482 rotates the first developing sleeve 44 , the second developing sleeve 45 , the first conveying screw 42 , and the third conveying screw 47 , and the second driving train 49 rotates the second conveying screw 43 . to rotate. In addition, since the first motor 102 that inputs drive to the first drive train 48 and the second motor 103 that inputs drive to the second drive train 49 are separate, the first developing sleeve 44 and the second developing sleeve 45 are driven. , the first conveying screw 42 and the third conveying screw 47, and the second conveying screw 43 can be driven independently of each other.

Here, as shown in FIG. 3, when the second conveying screw 43 is arranged below the first conveying screw 42, a transfer portion (second In the vicinity of the first communication portion 41d), the developer is conveyed against the direction of gravity, so the flow rate of the developer decreases and the developer tends to stay. At this time, the developer is compressed on the downstream side of the second conveying screw 43 in the developer conveying direction, and the load torque of the second conveying screw 43 increases.

For this reason, as in the present embodiment, by transmitting the driving force of the second conveying screw 43 to the independent second drive train 492, the load torque applied to each drive member including the first drive train 482 can be reduced. By distributing the drive trains, the load torque applied to the driving member can be reduced, and the life of the driving member can be reduced.

<Third Embodiment>
A third embodiment will be described with reference to FIG. In each of the above-described embodiments, a so-called twin-sleeve configuration in which two developing sleeves are arranged side by side has been described. On the other hand, in the present embodiment, a so-called single-sleeve configuration is adopted in which one developing sleeve 440 develops the electrostatic latent image on the photosensitive drum. Since other configurations and actions are the same as those of the above-described first embodiment or second embodiment, the same configurations are denoted by the same reference numerals, and explanations and illustrations are omitted or simplified. The description will focus on portions different from the first embodiment or the second embodiment.

The developing device 4B of this embodiment has one developing sleeve 440 as a developer carrier. Also in this embodiment, the first to third conveying screws 42 , 43 , 47 are provided. The third conveying screw 47 is arranged below the developing sleeve 440, collects the developer from the developing sleeve 440, and agitates and conveys the developer. In the case of this embodiment as well, similarly to the above-described first embodiment, a drive transmission section for transmitting driving force to the developing sleeve 440 and the third conveying screw 47, the first conveying screw 42 and the second conveying screw A drive transmission part for transmitting a driving force to the screw 43 is separated. Alternatively, as in the second embodiment, a drive transmission portion that transmits driving force to the developing sleeve 440, the first conveying screw 42, and the third conveying screw 47, and a drive transmitting portion that transmits the driving force to the second conveying screw 43. You may make it separate from a part. As a result, in the case of this embodiment as well, similarly to the first and second embodiments, the load torque applied to the drive transmission portion that transmits the drive to the developing sleeve 440 and the first to third conveying screws 42, 43, and 47 is reduced. can be reduced.

4, 4A Developing device 41a Developing chamber (first chamber)
41b... Stirring chamber (second chamber)
41c... partition wall 41d... first communicating portion 41e... second communicating portion 42... first conveying screw (first conveying member)
43 . . . Second conveying screw (second conveying member)
44 First developing sleeve (first developer carrier)
45 Second developing sleeve (second developer carrier, developer carrier)
46 Collecting member 47 Third conveying screw (third conveying member)
48, 482... First drive train (first drive transmission unit)
49, 492 . . . second drive train (second drive transmission unit)
440 Developing sleeve (developer carrier)

Claims (12)

A developing device disposed in an image forming apparatus main body for developing an electrostatic latent image formed on an image carrier with a developer,
a developer carrier that carries and transports a developer for developing the electrostatic latent image formed on the image carrier;
a first chamber for supplying the developer to the developer carrying member, a second chamber in which the developer circulates between the first chamber and the first chamber, a partition partitioning the first chamber and the second chamber; and a developer container containing a developer;
a first communicating portion that allows the developer to move from the second chamber to the first chamber;
a second communicating portion that allows the developer to move from the first chamber to the second chamber;
a first conveying member arranged in the first chamber for conveying the developer in a first direction from the first communicating portion to the second communicating portion;
a second conveying member disposed in the second chamber for conveying the developer in a second direction from the second communicating portion toward the first communicating portion;
a third conveying member arranged below the developer carrier for recovering the developer from the developer carrier and agitating and conveying the developer;
a first drive transmission unit that receives a first drive force from a drive source in the image forming apparatus main body and transmits the first drive force to the developer carrier and the third conveying member;
a second drive that receives a second drive force from a drive source in the image forming apparatus main body and transmits the second drive force to the first and second transport members separately from the first drive transmission unit; A developing device comprising: a transmission section. 2. The developing device according to claim 1, wherein the first drive transmission section and the second drive transmission section can be driven independently of each other. 3. The developing device according to claim 1, wherein the second conveying member is arranged below the first conveying member in the direction of gravity. The developing device according to any one of claims 1 to 3, wherein the first drive transmission section and the second drive transmission section are gear trains, respectively. A developing device disposed in an image forming apparatus main body for developing an electrostatic latent image formed on an image carrier with a developer,
a first developer carrier that carries and transports a developer for developing the electrostatic latent image formed on the image carrier;
a second developer carrier disposed in parallel with the first developer carrier with a predetermined gap therebetween and carrying and transporting the developer in order to develop the electrostatic latent image formed on the image carrier; ,
a first chamber for supplying the developer to the first developer bearing member, a second chamber in which the developer circulates between the first chamber and a partition wall for partitioning the first chamber and the second chamber. and a developer container containing a developer, and
a first communicating portion that allows the developer to move from the second chamber to the first chamber;
a second communicating portion that allows the developer to move from the first chamber to the second chamber;
a first conveying member arranged in the first chamber for conveying the developer in a first direction from the first communicating portion to the second communicating portion;
a second conveying member disposed in the second chamber for conveying the developer in a second direction from the second communicating portion toward the first communicating portion;
a third conveying member arranged below the second developer bearing member for collecting the developer from the second developer bearing member and stirring and conveying the developer;
a first drive that receives a first driving force from a driving source in the image forming apparatus main body and transmits the first driving force to the first developer carrier, the second developer carrier, and the third conveying member; a transmission unit;
a second drive that receives a second drive force from a drive source in the image forming apparatus main body and transmits the second drive force to the first and second transport members separately from the first drive transmission unit; A developing device comprising: a transmission section. 6. The developing device according to claim 5, wherein the first drive transmission section and the second drive transmission section can be driven independently of each other. 7. The developing device according to claim 5, wherein the second conveying member is arranged below the first conveying member with respect to the direction of gravity. The developing device according to any one of claims 5 to 7, wherein each of the first drive transmission section and the second drive transmission section is a gear train. A developing device disposed in an image forming apparatus main body for developing an electrostatic latent image formed on an image carrier with a developer,
a first developer carrier that carries and transports a developer for developing the electrostatic latent image formed on the image carrier;
a second developer carrier disposed in parallel with the first developer carrier with a predetermined gap therebetween and carrying and transporting the developer in order to develop the electrostatic latent image formed on the image carrier; ,
a first chamber for supplying the developer to the first developer bearing member, a second chamber in which the developer circulates between the first chamber and a partition wall for partitioning the first chamber and the second chamber. and a developer container containing a developer, and
a first communicating portion that allows the developer to move from the second chamber to the first chamber;
a second communicating portion that allows the developer to move from the first chamber to the second chamber;
a first conveying member arranged in the first chamber for conveying the developer in a first direction from the first communicating portion to the second communicating portion;
a second conveying member disposed in the second chamber for conveying the developer in a second direction from the second communicating portion toward the first communicating portion;
a third conveying member arranged below the second developer bearing member for collecting the developer from the second developer bearing member and stirring and conveying the developer;
receiving a first driving force from a driving source in the image forming apparatus main body, and applying the first driving force to the first developer carrier, the second developer carrier, the first conveying member, and the third conveying member; a first drive transmission unit that transmits the
a second drive transmission section that receives a second drive force from a drive source in the image forming apparatus main body and transmits the second drive force to the second conveying member separately from the first drive transmission section. A developing device characterized by: 10. The developing device according to claim 9, wherein the first drive transmission section and the second drive transmission section can be driven independently of each other. 11. The developing device according to claim 9, wherein the second conveying member is arranged below the first conveying member with respect to the direction of gravity. The developing device according to any one of claims 9 to 11, wherein each of the first drive transmission section and the second drive transmission section is a gear train.

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