JP2013076755A - Developer transporting device, and process cartridge - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce a size of a developer transporting device, which regulates drive of a developer transporting member if developer in a developer storage unit is aggregated during distribution.SOLUTION: A developer transporting device comprises: a developer transporting member 25 that is arranged inside a developer storage unit 15, and rotates to transport developer; and a clutch 70 that can be, if a driving force required for rotating the developer transporting member 25 exceeds a predetermined amount, in a state of regulating a transmission of a driving force from a drive input unit 32 to the developer transporting member 25. The clutch 70 is attached inside the developer storage unit 15.

Description

  The present invention relates to a developer transport device used in an image forming apparatus, and a process cartridge including the developer transport device.

  Here, the developer transport device is a device that transports the developer used in the image forming apparatus. For example, a process cartridge, a developer replenishment cartridge, and a developer conveying means in an electrophotographic image forming apparatus are included.

  An image forming apparatus forms an image on a recording medium. Examples include an electrophotographic copying machine that forms an image using an electrophotographic process, an electrophotographic printer (such as an LED printer or a laser beam printer), and an electrophotographic facsimile machine.

  The recording medium is an object on which an image is formed, and is, for example, a recording sheet, an OHP sheet, or the like.

  2. Description of the Related Art Conventionally, an image forming apparatus employs a process cartridge system in which a photosensitive drum and process means acting on the photosensitive drum are integrally formed into a cartridge that can be attached to and detached from the image forming apparatus main body. The process cartridge system can improve the operability because the apparatus can be maintained by the user.

  The process cartridge is formed of a cleaning device (hereinafter referred to as a cleaning unit) and a developing device (hereinafter referred to as a developing unit). The cleaning unit includes a photosensitive drum, a cleaning member that cleans the surface of the photosensitive drum, and the like. The developing unit includes a developing roller that supplies the developer to the photosensitive drum, a developer accommodating portion that accommodates the developer, and the like.

  On the other hand, a developer supply system is known as one of the process cartridge systems. In this system, the developer supply opening of the developer supply cartridge is connected to the developer receiving opening of the process cartridge, and the developer is supplied from the developer supply cartridge to the process cartridge.

  In the developer replenishing system, when a new developer replenished from the developer replenishing cartridge and an old developer in the developing unit are mixed non-uniformly, an image defect is caused. Therefore, a developer replenishment process cartridge has the following configuration (for example, Patent Document 1).

  The development unit is divided into a development unit and a developer storage unit. The developing section and the developer accommodating section are connected by openings provided at both ends in the rotational axis direction (hereinafter referred to as “longitudinal direction”) of the photosensitive drum. The developer accommodating portion is provided with a developer conveying member for conveying the developer and a developer agitating member for agitating the developer. The developer is circulated in the developing unit by the developer conveying member and the developer agitating member, so that the new developer and the old developer are uniformly mixed.

  However, the developer in the developer container may be pressed and aggregated depending on the physical distribution. In particular, when the process cartridge at the time of distribution is in a posture in which the longitudinal direction thereof is oriented in the vertical direction and the downstream side in the transport direction of the developer transport member is the bottom surface, the aggregated developer is removed from the developer transport member. Accumulate on the downstream side in the transport direction. If the process cartridge is used in this state, the agglomerated developer is further pressed and solidified by the developer conveying member, and thus the torque required to drive the developer conveying member may increase.

  As a countermeasure, there is a configuration in which a clutch is provided on the drive gear train of the developer agitating member and the developer conveying member as in Patent Document 2. When driving the developer agitating member and the developer conveying member with the same driving source, if the driving source is overloaded, the rotation of the developer conveying member is stopped by the clutch, and only the developer agitating member is It is a structure to rotate.

  Further, as disclosed in Patent Document 3, there is a configuration in which a torque limiter is connected to a driving gear of a developer stirring member, and when an overload is applied, the driving of the developer stirring member is cut off and only toner seal pulling driving is rotated.

JP 2010-014890 A (FIG. 4) Japanese Patent Laid-Open No. 11-160985 (FIG. 1) JP 2009-116039 A (FIG. 1)

  In the configurations of Patent Documents 2 and 3, since the clutch and the torque limiter are provided on the drive gear train, the size of the apparatus is increased.

  Therefore, in view of the above problems, an object of the present invention is to reduce the size of the apparatus by providing a clutch inside the developer accommodating portion.

  A typical configuration according to the present application for achieving the above object is arranged in a developer conveying device used in an image forming apparatus, a developer accommodating portion for accommodating a developer, and the developer accommodating portion. A developer conveying member that conveys the developer by rotation, a drive input unit that receives a driving force for driving the developer conveying member, and a state in which the driving force is transmitted from the driving input unit to the developer conveying member. A state of restricting transmission of the driving force from the drive input unit to the developer conveying member when a driving force necessary for rotating the developer conveying member exceeds a predetermined magnitude; A developer transport device, wherein the clutch is attached to the inside of the developer accommodating portion.

  As described above, according to the present invention, the developer conveying device can be reduced in size by providing the clutch inside the developer accommodating portion.

Schematic sectional view of the developing unit in the embodiment of the present invention 1 is a schematic cross-sectional view of an electrophotographic image forming apparatus according to an embodiment of the present invention. Main sectional views of a process cartridge and a developer supply cartridge in the embodiment of the present invention 1 is a perspective view showing an overall image of a process cartridge and a developer supply cartridge in an image forming apparatus according to an embodiment of the present invention. The exploded perspective view which shows the whole image of the process cartridge in embodiment of this invention 1 is a schematic perspective view showing the configuration of a developer supply cartridge according to an embodiment of the present invention. The exploded perspective view of the clutch part in an embodiment of the invention Schematic sectional view showing the periphery of the clutch portion of the developer conveying member in the embodiment of the present invention Front view showing the engaging member

  Hereinafter, a developer conveying device, a process cartridge and a color image forming apparatus employing the same according to the present invention will be described with reference to the drawings.

<Example 1>
[Entire configuration of image forming apparatus]
First, the overall configuration of the image forming apparatus will be described with reference to FIGS. FIG. 2 is a schematic cross-sectional view showing an outline of a color electrophotographic image forming apparatus. FIG. 3 is a main cross-sectional view of the process cartridge and the developer supply cartridge.

  An image forming apparatus 100 shown in FIG. 2 is a four-color full-color laser printer using an electrophotographic process, and forms a color image on a recording medium S. The image forming apparatus 100 is a process cartridge type. In this method, a process cartridge P and a developer supply cartridge T are detachably attached to the image forming apparatus main body 100A, and a color image is formed on a recording medium S.

  In the following description, an image forming apparatus main body (hereinafter, referred to as “apparatus main body”) 100A refers to an apparatus configuration portion excluding the process cartridge P and the developer supply cartridge T from the configuration of the image forming apparatus 100. .

  In the apparatus main body 100A, first to fourth process cartridges P (PY, PM, PC, PK) and a developer supply cartridge T (TY, TM, TC, TK) are arranged in a horizontal direction. Yes. Each process cartridge P and developer supply cartridge T have the same electrophotographic process mechanism, and are different in developer color and developer filling amount. A rotation driving force is transmitted from the apparatus main body 100A to the process cartridge P and the developer supply cartridge T, respectively. The process cartridge P is supplied with a bias (charging bias, developing bias, etc.) from the apparatus main body 100A. The process cartridge P and the developer supply cartridge T can be attached to and detached from the apparatus main body 100A independently.

  Each process cartridge P in this embodiment is formed of a cleaning unit 1 and a developing unit 10 as shown in FIG. The cleaning unit 1 includes a photosensitive drum 2, a charging roller 3 that acts on the photosensitive drum 2, and a cleaning member 6. The developing unit 10 has developing means for developing the electrostatic latent image on the photosensitive drum 2. The cleaning unit 1 and the developing unit 10 are coupled to each other so as to be swingable.

  The first process cartridge PY contains a yellow (Y) developer in the developer accommodating portion 15 and forms a Y color developer image on the photosensitive drum 2. Similarly, the second process cartridge PM contains magenta (M), the third process cartridge PC contains cyan (C), and the fourth process cartridge PK contains black (K) developer.

  On the other hand, the first developer supply cartridge TY contains yellow (Y) developer in the supply frame 40, and supplies the Y developer to the process cartridge PY containing the same color developer. . Similarly, the second developer supply cartridge TM stores magenta (M) developer, and supplies the M color developer to the process cartridge PM containing the same color developer. Similarly, the third developer supply cartridge TC contains cyan (C) developer, and supplies the C color developer to the process cartridge PC containing the same color developer. Similarly, the fourth developer supply cartridge TK contains black (K) developer, and supplies the K color developer to the process cartridge PK containing the same color developer.

  As shown in FIG. 3, the supply frame 40 of the developer supply cartridge T is provided with a developer supply opening 43 for supplying developer to the process cartridge P. In the developer accommodating portion 15 of the process cartridge P, a developer receiving port 23 corresponding to the developer supply opening 43 is provided. When the process cartridge P and the developer supply cartridge T are attached to the apparatus main body 100A, the developer supply opening 43 and the developer receiving port 23 communicate with each other, and the developer is supplied from the developer supply cartridge T to the process cartridge P. Is done.

  Details of the process cartridge P and the developer supply cartridge T will be described later.

  As shown in FIG. 2, a laser scanner unit LB as an exposure unit is disposed above the process cartridge P (PY / PM / PC / PK). The laser scanner unit LB outputs laser light L corresponding to the image information. The laser beam L scans and exposes the surface of the photosensitive drum 2.

  Below the process cartridge P (PY / PM / PC / PK), an intermediate transfer belt unit 110 as a primary transfer member is disposed. The intermediate transfer belt unit 110 includes an endless transfer belt 111 having flexibility, a driving roller 112 that stretches and rotates the transfer belt 111, a driven roller 113, and a secondary transfer counter roller 114. The photosensitive drum 2 of each process cartridge P is in contact with the transfer belt 111. A contact portion N1 between the photosensitive drum 2 and the transfer belt 111 is a primary transfer portion. A primary transfer roller 115 is disposed inside the transfer belt 111 so as to face the photosensitive drum 2. A secondary transfer roller 117 as a secondary transfer unit is disposed at a position facing the secondary transfer counter roller 114. A contact portion N2 between the transfer belt 111 and the secondary transfer roller 117 is a secondary transfer portion.

  A feeding unit 120 is disposed below the intermediate transfer belt unit 110. The feeding unit 120 is a recording medium transport unit that transports the recording medium S, and includes a feeding tray 121 that stores the recording medium S and a feeding roller 122.

  A fixing unit 130 is disposed above the apparatus main body 100A. The upper surface of the apparatus main body 100A is a discharge tray 100a.

[Image forming operation]
Next, a full color image forming operation will be described with reference to FIG. FIG. 2 is a schematic sectional view of the color electrophotographic image forming apparatus. The full color image forming operation is as follows.

  The photosensitive drums 2 of the first to fourth cartridges P (PY, PM, PC, PK) are rotationally driven at a predetermined speed in the direction of arrow A in FIG. The transfer belt 111 is rotationally driven in the direction of arrow B (forward direction with respect to the photosensitive drum rotation). At this time, the speed of the transfer belt 111 corresponds to the speed of the photosensitive drum 2. At the same time, the laser scanner unit LB is driven.

  In synchronization with the driving of the laser scanner unit LB, the charging roller 3 of each cartridge P uniformly charges the surface of the photosensitive drum 2 with a predetermined polarity and potential. The laser scanner unit LB scans and exposes the surface of each photosensitive drum 2 with a laser beam L corresponding to the image signal of each color. As a result, an electrostatic latent image corresponding to the image signal of the corresponding color is formed on the surface of each photosensitive drum 2. The formed electrostatic latent image is developed by the developing roller 11. The developing roller 11 is a developer carrying member, and carries a developer for developing the latent image formed on the photosensitive drum 2 as an image carrying member.

  By the above image forming operation, a Y color developer image is formed on the photosensitive drum 2 of the first cartridge PY. Then, the Y developer image is primarily transferred onto the transfer belt 111. Similarly, the developer images of the second cartridge PM, the third cartridge PC, and the fourth cartridge PK are superimposed on the transfer belt 111 to form a four-color full-color unfixed developer image. In each process cartridge P, the developer remaining on the surface of the photosensitive drum 2 after the primary transfer is removed by the cleaning member 6.

  On the other hand, the recording medium S accommodated in the tray 121 is fed at a predetermined control timing. The four color superimposed developer images on the transfer belt 111 are collectively transferred onto the surface of the recording medium S introduced into the secondary transfer nip N2.

  The recording medium S is separated from the surface of the transfer belt 111 and introduced into the fixing unit 130. Then, it is heated and pressurized at the fixing nip portion. As a result, the developer image is fixed on the recording medium S. Thereafter, the recording medium S that has been fixed is conveyed to the discharge tray 100a, whereby the full-color image forming operation is completed.

[Overall configuration of process cartridge]
Next, the overall configuration of the process cartridge P will be described with reference to FIGS. 3, 4, and 5. FIG. FIG. 3 is a main cross-sectional view of the process cartridge and the developer supply cartridge. FIG. 4 is a perspective view showing an overall image of a process cartridge and a developer supply cartridge in the image forming apparatus. FIG. 5 is a perspective view showing an overall image of the process cartridge.

  As shown in FIG. 3, the cartridge P (PY / PM / PC / PK) is formed of a cleaning unit 1 and a developing unit 10.

  First, the cleaning unit 1 will be described. The cleaning unit 1 includes a photosensitive drum 2, a charging roller 3, and a cleaning member 6 in a cleaning frame 7.

  The photosensitive drum 2 is rotatably supported by the cleaning frame 7. As shown in FIG. 4, a drum drive coupling 2 a is provided at one end of the photosensitive drum 2. The photosensitive drum 2 and the drum drive coupling 2a are integrally formed. The drum drive coupling 2a is engaged with a coupling (not shown) of the apparatus main body 100A. By transmitting a driving force of a driving motor (not shown) of the apparatus main body to the drum driving coupling 2a, the photosensitive drum 2 is rotationally driven at a predetermined speed in the direction of arrow A in FIG.

  The charging roller 3 rotates while being in contact with the photosensitive drum 2. As shown in FIG. 3, the charging roller 3 is attached to the cleaning frame body 7 via the charging roller bearing 4. The charging roller 3 is attached to be movable in the direction of arrow E in FIG. 3 along a line connecting the rotation center of the charging roller 3 and the rotation center of the photosensitive drum 2. A rotation shaft 3 a of the charging roller 3 is rotatably supported by the charging roller bearing 4. The charging roller bearing 4 is urged toward the photosensitive drum 2 by the charging roller pressing member 5.

  The cleaning member 6 includes an elastic rubber blade 6a at the tip and a support metal plate 6b. The tip of the elastic rubber blade 6a is in contact with the rotation direction of the photosensitive drum 2 (the direction of arrow A in FIG. 3) in the counter direction. The cleaning member 6 removes the developer remaining on the photosensitive drum 2. The developer removed from the peripheral surface of the photosensitive drum 2 by the cleaning member 6 is accommodated in the removed developer accommodating portion 7 a of the cleaning frame 7.

  Next, the developing unit 10 will be described. As shown in FIG. 3, the developing unit 10 includes a developing frame 14 that supports various elements in the developing unit 10. The developing device frame 14 is divided into a developing unit 16 and a developer container 15.

  The developing unit 16 includes a developing roller 11, a developer supply roller (hereinafter referred to as “supply roller”) 12, and a developing blade 13. The developing roller 11 rotates in the direction of arrow D in contact with the photosensitive drum 2. The supply roller 12 rotates in the direction of arrow F while being in contact with the developing roller 11. The supply 12 roller has two roles. One is to supply a developer onto the developing roller 11. The other is to strip off the developer remaining on the developing roller 11 without being supplied for development. The developing blade 13 is in contact with the peripheral surface of the developing roller 11 to regulate the developer layer thickness on the developing roller 11.

  On the other hand, the developer accommodating portion 15 accommodates the developer replenished from the developer replenishing cartridge T. Details of the developer container 15 will be described later.

  Next, the coupling between the cleaning unit 1 and the developing unit 10 will be described. As shown in FIG. 5, the cleaning frame 7 has cleaning coupling holes 8 (8R, 8L). As shown in FIGS. 3 and 5, the developing frame 14 is provided with development side plates 19 (19R, 19L) at both ends in the longitudinal direction. The development side plate 19 (19R, 19L) has a development coupling hole 20 (20R, 20L). As shown in FIGS. 3 and 5, the cleaning coupling hole 8 (8R, 8L) and the development coupling hole 20 (20R, 20L) are swingably coupled by fitting with the coupling shaft 21 (21R, 21L). Is done. Thereby, the cleaning unit 1 and the developing unit 10 are coupled.

  Between the cleaning unit 1 and the developing unit 10, as shown in FIG. 5, pressure springs 22 are arranged at both ends. By the urging force of the pressure spring 22, the developing unit 10 obtains a rotational moment in the direction of arrow G about the developing coupling hole 20. As a result, the developing roller 11 comes into contact with the photosensitive drum 2.

  In the present embodiment, the developing roller 11 is disposed in contact with the photosensitive drum 2, but may be configured to be disposed at a predetermined interval.

[Overall configuration of developer supply cartridge]
Next, the configuration of the developer supply cartridge T will be described with reference to FIGS. FIG. 3 is a main cross-sectional view of the process cartridge and the developer supply cartridge. FIG. 6 is a perspective view showing the configuration of the developer supply cartridge T. FIG.

  As shown in FIG. 3, the developer supply cartridge T has a supply frame 40 for containing the developer. The supply frame 40 has a developer supply opening 43 for supplying developer to the process cartridge P. A developer supply shutter 44 is provided below the developer supply opening 43. Normally, the developer supply shutter 44 is closed, but is configured to open when the process cartridge P and the developer supply cartridge T are mounted on the apparatus main body 100A.

  In the supply frame 40, a supply conveyance member 41 and a supply stirring member 42 are provided. The replenishment conveyance member 41 and the replenishment stirring member 42 are rotatably supported by the replenishment frame body 40. The supply transport member 41 transports the developer in the supply frame 40 toward the developer supply opening 43. As shown in FIG. 6, the replenishment conveying member 41 is a screw member having helical fins 41 a and return fins 41 b formed on the surface. The fin 41a conveys the developer in the arrow Q direction. The return fin 41b conveys the developer in the direction opposite to the fin 41a. The replenishing stirring member 42 has two roles. One is to stir the developer in the supply frame 40. The other is to send the stirred developer to the replenishment conveying member 41. The replenishing stirring member 42 is formed of a replenishing stirring rod 42a and a replenishing stirring sheet 42b. A cover member 47 is provided above the replenishment transport member 41. The cover member 47 covers a part of the developer supply opening 43 and the supply conveyance member 41 in the longitudinal direction. The cover member 47 is provided with a return hole 47a.

  A supply transport coupling 45 and a supply stirring coupling 46 are provided at one end in the longitudinal direction of the supply transport member 41 and the supply stirring member 42, respectively. The supply transport coupling 45 and the supply agitation coupling 46 engage with a coupling (not shown) of the apparatus main body 100A. When the driving force of a drive motor (not shown) of the apparatus main body 100A is transmitted to the replenishing conveyance coupling 45 and the replenishing stirring coupling 46, the replenishing conveyance member 41 and the replenishing stirring member 42 are rotationally driven at a predetermined speed. .

  The conveyance of the developer in the developer supply cartridge T will be described. The developer in the supply frame body 40 is stirred by the supply stirring member 42 and sent to the supply transport member 41. A part of the developer sent to the replenishment transport member 41 is regulated by the cover member 47 when transported to the cover member 47. As a result, the amount of developer discharged from the developer supply opening 43 becomes constant. The developer conveyed into the cover member 47 is discharged from the developer supply opening 43 to the process cartridge P. The developer that has not dropped from the developer supply opening 43 is sent to the supply stirring member 42 from the return hole 47a by the return fin 41b and is stirred again.

[Configuration of developer transport device]
Next, the configuration of the developer conveying means (developer conveying device) 9 used in the image forming apparatus 100 will be described with reference to FIG. FIG. 1A is a schematic cross-sectional view of the developing unit 10 in a state where the sealing member 80 is present. FIG. 1B is a schematic cross-sectional view of the developing unit 10 in a state where a part of the sealing member 80 is pulled.

  In this embodiment, the developer transport device 9 is configured by members such as the developer container 15 provided in the developing unit and the developer transport member 25 attached to the developer container 15.

  As shown in FIG. 1, the developer accommodating portion 15 is divided into a first accommodating portion 15 a and a second accommodating portion 15 b by a partition portion 29. The 1st accommodating part 15a and the 2nd accommodating part 15b are connected by the 1st opening 17 and the 2nd opening 18 which were provided in the both ends of the longitudinal direction.

  A developer receiving opening 23 is provided in the first accommodating portion 15a. The developer receiving opening 23 is connected to the developer supply opening 43 of the developer supply cartridge T. By connecting the developer supply opening 43 and the developer receiving opening 23, the developer is supplied from the developer supply cartridge T to the process cartridge P. A developer receiving shutter 26 is disposed above the developer receiving opening 23. Normally, the developer receiving shutter 26 is closed, but is configured to open when the process cartridge P and the developer supply cartridge T are mounted on the apparatus main body 100A.

  The second accommodating portion 15 b is connected to the developing portion 16 through the developing opening 28. When the process cartridge P is not used, the developing opening 28 is sealed with a sealing member 80. Here, the development opening 28 is an opening for discharging the developer from the developer accommodating portion 15. The sealing member 80 is attached to the developing opening 28 to prevent the developer from leaking from the developer containing portion 15 when the process cartridge P is distributed. The sealing member 80 is adhered to the surface of the development opening 28 by welding or the like.

  One end in the longitudinal direction of the sealing member 80 is folded back as shown in FIG. 1, passes through a seal opening 14 a provided in the developing device frame 14, and extends to the outside of the developing device frame 14. A seal member 51 is provided in the seal opening 14a. The seal member 51 prevents the developer from leaking from the seal opening 14a. An end 80 b in the longitudinal direction of the folded portion 80 a of the sealing member 80 is coupled to the winding member 38 outside the developing device frame 14. The sealing member 80 is bonded to the winding shaft portion 38b with a double-sided tape or the like. When the process cartridge P is used, the sealing member 80 is removed by being wound by the winding member 38. The winding member 38 is a removing member for removing (removing) the sealing member 80 from the developing opening 28.

  A developer stirring member 24 is provided in the first housing portion 15a. The developer stirring member 24 has two roles. One is to mix the developer in the developer container 15 and the developer replenished from the developer replenishment cartridge T. The other is to transport the mixed developer in the direction of arrow H. That is, when the developer transport member 25 is the first developer transport member, the developer stirring member becomes the second developer transport member. The developer stirring member 24 has a configuration in which a stirring spring 24c is attached to a developing support shaft 24b provided around the developing stirring shaft 24a.

  A developer transport member 25 is provided in the second storage portion 15b. The developer transport member 25 is a screw member that transports the developer in the arrow J direction (developer transport direction). At this time, the developer conveying speed by the developer agitating member 24 is set slower than the developer conveying speed by the developer conveying member 25.

  The conveyance of the developer in the developing unit 10 will be described. The developer supplied from the developer supply cartridge T is mixed with the developer in the developer storage unit 15 by the developer stirring member 24 in the first storage unit 15a. The mixed developer is sent to the second storage portion 15 b through the first opening 17. In the second storage portion 15 b, the developer is transported from the development opening 28 to the developing portion 16 by the developer transport member 25. The developer conveyed to the developing unit 16 is sent to the developing roller 11 via the supply roller 12 and developed. The developer that has not been supplied to the development returns from the developing unit 16 to the second storage unit 15b again. Thereafter, the developer is transported from the second opening 18 to the first storage portion 15 a by the developer transport member 25. The developer is circulated by repeating this state.

[Development unit drive configuration]
Next, the driving configuration of the developing unit will be described with reference to FIGS. FIG. 1 is a schematic sectional view of the developing unit. FIG. 5 is a perspective view showing an overall image of the process cartridge P. FIG.

  As shown in FIG. 1, a developing roller gear 30 for transmitting drive to the developing roller 11 is provided at one end of the developing roller 11. A supply roller gear 31 for transmitting drive to the supply roller 12 is provided at one end of the supply roller 12. At one end of the developer transport member 25, a development transport gear 32 for transmitting drive to the developer transport member 25 is provided. One end of the developer stirring member 24 is provided with a first development stirring gear 33 for transmitting drive to the developer stirring member 24. The development transport gear 32 is a drive input unit to which a driving force for rotating the developer transport member 25 is input.

  At the other end of the developer stirring member 24, a second development stirring gear 34 for transmitting the drive from the developer stirring member 24 is provided.

  On the other hand, a developing drive coupling 27 is provided at one end of the developing unit 10 in the longitudinal direction, as shown in FIG. The development drive coupling 27 engages with a coupling (not shown) of the apparatus main body 100A. The development drive coupling 27 rotates at a predetermined speed when a drive force of a drive motor (not shown) of the apparatus main body is transmitted.

  The driving force of the driving motor of the apparatus main body 100A is transmitted from the development driving coupling 27 through the following path.

  The drive of the development drive coupling 27 is transmitted from the gear portion 27a of the development drive coupling 27 to the development roller gear 30 and the supply roller gear 31 via the first idler gear 35 and the second idler gear 36, as shown in FIG. . As a result, the developing roller 11 and the supply roller 12 are driven.

  The driving of the first idler gear 35 is also transmitted to the first developing stirring gear 33, and the developer stirring member 24 is driven. The driving of the developer agitating member 24 is transmitted from the second developing agitating gear 34 to the developing and conveying gear 32 via the third idler gear 37, and the developer conveying member 25 is driven.

  The drive of the third idler gear 37 is also transmitted to the fourth idler gear 39. The drive of the fourth idler gear is transmitted to the winding member 38, and the winding member 38 rotates. As a result, the sealing member 80 is wound up and removed from the development opening 28.

  When the process cartridge P is mounted on the apparatus main body 100A and a new state is detected, the development drive coupling 27 is driven, and the winding of the sealing member 80 is started.

  At this time, the developing drive coupling 27 is subjected to the developing roller 11, the supply roller 12, the developer stirring member 24, the developer conveying member 25, the winding member 38 of the sealing member 80, and the load torque required to drive them. .

  In particular, due to physical distribution, development is performed downstream in the developer transport direction J by the developer transport member 25 in the second storage portion 15b and upstream in the developer transport direction H by the developer stirring member 24 in the first storage portion 15a. It has been found that the load torque is greatest when the agent is agglomerated.

  One reason for this is that when the developer conveying member 25 and the developer agitating member 24 are started, the speed of the developer moving in the first accommodating portion 15a moves in the second accommodating portion 15b. This is because it is slower than the speed of the agent. Accordingly, the developer transported from the second storage portion 15b to the first storage portion 15a through the second opening 18 is likely to be clogged downstream in the developer transport direction J. Even after the developer is clogged, if the developer conveying member 25 continues to be driven, the load torque required to drive the developer conveying member 25 will increase.

  On the other hand, when the developer aggregates on the upstream side in the developer transport direction J, the developer transport speed of the second storage portion 15b is faster than the developer transport speed of the first storage portion 15a, Since there is a space on the downstream side in the developer transport direction J of the storage portion 15b, the aggregation of the developer is eliminated. Therefore, compared with the case where the developer aggregates on the downstream side in the developer transport direction J, when the developer aggregates on the upstream side in the developer transport direction J, the load torque of the developer transport member 25 is small.

  As a countermeasure against the problem that the load torque increases when the developer aggregates on the downstream side in the developer transport direction J, in the present embodiment, the second storage portion with respect to the developer transport member 25 to which the load torque is most applied. A clutch portion 70 is provided inside 15b. The clutch portion 70 is provided in the developer accommodating portion 15 and is provided between the developer conveying member 25 and the developer conveying gear 32 and coaxially therewith.

  By accommodating the clutch portion 70 inside the developer accommodating portion 15, it is possible to reduce the size of the developing device and the process cartridge as compared with the case where the clutch portion 70 is provided outside the developer accommodating portion 15.

  When the load torque of the developer conveying member 25 is equal to or greater than a certain level, the clutch unit 70 operates and the drive is cut off. Since the drive transmission to the fourth idler gear 39 is performed while the driving of the developer conveying member 25 is interrupted, the winding of the sealing member 80 is continuously performed. When the sealing member 80 is wound, the developing opening 28 starts to open from the folded portion of the sealing member 80 as shown in FIG. As a result, the developer aggregated in the second accommodating portion 15 b starts to fall into the developing portion 16. When the developer falls on the developing unit 16, the load torque for driving the developer transport member 25 is reduced, the drive of the development transport gear 32 is transmitted to the developer transport member 25, and the developer transport member 25 is driven. Start.

  Further, since the developer agitating member 24 continues to be driven even when the driving of the developer conveying member 25 is interrupted, the developer aggregating member 24 can also eliminate the aggregation of the developer.

  Note that the upstream side of the developer transport direction J by the developer transport member 25 in the second storage section 15b of the developer storage section and the downstream side of the developer transport direction H by the developer stirring member 24 in the first storage section 15a. When the developer aggregates, the driving of the developer conveying member 25 is not interrupted. The reason is that, as described above, the aggregated developer is conveyed while being loosened, so that the load torque of the developer conveying member 25 does not increase greatly. At this time, the clutch unit 70 does not operate.

  In other words, it is particularly necessary to operate the clutch unit 70 to cut off the driving of the developer transport member 25 when the developer is aggregated on the downstream side in the developer transport direction J. At this time, since the developer is not aggregated on the upstream side in the developer transport direction J where the clutch unit 70 is disposed, the malfunction of the clutch unit 70 due to the influence of the developer is suppressed.

[Composition of clutch part]
Next, the detailed structure of the clutch part in a present Example is demonstrated using FIG. 7, FIG. FIG. 7 is an exploded perspective view of the developing and conveying member and the clutch portion. FIG. 8A is a schematic cross-sectional view of the clutch portion during driving of the developing and conveying member. FIG. 8B is a schematic cross-sectional view of the clutch portion when the driving of the developing conveyance member is cut off.

As shown in FIG. 7, in a state where a compression coil spring (hereinafter referred to as a compression spring) 71 that is an elastic member and an engaging member 72 are attached on the same axis as the developer transport member 25, The developing conveyance gear 32 is attached from the outside of the developing device frame 14 to the second accommodating portion 15b. At this time, the compression spring 71 is held between the spring receiving surface 25e of the developer conveying member 25 and the spring receiving portion 72e of the engaging member 72.
Further, the inner peripheral portion 72b of the engaging member 72 and the outer peripheral portion 32a of the developing and conveying gear 32 are engaged.

Next, the state at the time of the drive of the developer conveyance member 25 is demonstrated using FIG. 7, FIG. 8 (a).
On the inner peripheral portion 72b of the engagement member 72, rib-shaped drive transmission portions 72c and 72d are provided. The developer conveying member 25 has a cylindrical portion 25b, and has a slit 25a at a position facing the drive transmission portions 72c and 72d. The engaging member 72 is engaged with the cylindrical portion 25b so that the inner peripheral portion 72b can move in the axial direction.

  Since the engaging member 72 can move in the axial direction with a low load, the width of the slit 25a is greater than the width of the drive transmission portions 72c and 72d.

  The drive transmission units 72 c and 72 d have a function of receiving the driving force of the developing and conveying gear 32 and transmitting the driving force to the developer conveying member 25. Further, the developing and conveying gear 32 has an inclined surface (hereinafter referred to as a cam surface 32b) that is inclined with respect to the rotation axis of the developer conveying member and engages with the engaging member 72. As for the development conveyance gear 32, the cam surface 32 b comes into contact with the drive transmission portions 72 c and 72 d and transmits the driving force to the engagement member 72. Thereafter, the drive transmission portions 72c and 72d are brought into contact with the driven transmission surfaces 25c and 25d while being engaged with the slits 25a of the developer conveying member 25, and the developer conveying member 25 is driven.

Next, the state when the driving of the developer conveying member 25 is cut off will be described with reference to FIGS. 7 and 8B.
When the load torque of the developer conveying member 25 becomes a certain level or more, the drive transmission portions 72c and 72d of the engaging member 72 are compressed in the direction in which the compression spring 71 is compressed along the cam surface 32b of the rotating developer conveying gear 32 (arrow). Move in the V direction). At this time, the axial force applied to the drive transmission portions 72 c and 72 d of the engaging member 72 is larger than the force applied from the compression spring 71 to the engaging member 72. Then, as shown in FIG. 8B, when the drive transmission parts 72c and 72d reach a position where they come into contact with the apex 32d of the cam surface 32b, the rotational drive transmission from the developing conveyance gear 32 to the engaging member 72 is performed. I will not be broken. At this time, the development conveyance gear 32 is idled. By this operation, driving to the developer conveying member 25 is interrupted.

  That is, the engaging member 72 is a position (drive transmission position) for transmitting a driving force to the developer conveying member 25 (see FIG. 8A) and a restriction position for restricting the transmission of the driving force to the developing conveying member 25 (see FIG. 8A). It is a moving member which can move (refer FIG.8 (b)). The engagement member 72 is urged toward the drive transmission position by the compression spring 71. If the driving force (load torque) necessary for driving the developer conveying member 25 exceeds a predetermined magnitude, the engagement member 72 is driven. Move from the transmission position to the restriction position.

  In the present embodiment, the engagement member 72 is moved twice in one driving cycle of the developing and conveying gear 32. When the rotation torque of the developer conveying member 25 becomes a certain value or less, the driving of the developer conveying member 25 is started by the cam surface 32b of the developing and conveying gear 32.

  As described above, with a simple configuration in which only the compression spring 71 and the engagement member 72 are added, the drive can be cut off when the load torque becomes a certain level or more.

  In the present embodiment, as described above, the clutch unit 70 is provided on the upstream side of the developer transport member 25 in the developer transport direction J. Therefore, even when the developer aggregates on the downstream side in the developer transport direction J and the load torque of the developer transport member 25 increases, the periphery of the clutch portion 70 located on the upstream side in the developer transport direction J Then, the density of the developer is relatively small. When the driving force transmitted to the developer conveying member 25 is interrupted, even if the engaging member 72 moves, the resistance force that the engaging member 72 receives from the developer is reduced. As a result, the clutch unit 70 reliably interrupts transmission of the driving force without causing malfunction due to the developer.

  9 shows a front view of the engaging member 72 viewed from the downstream side in the direction of arrow V in FIG. As shown in FIG. 9, the engaging member 72 is provided with a through hole 70 g that penetrates the engaging member 72. The through hole 70g allows the developer around the engaging member 72 to pass when the engaging member 72 moves. As a result, the resistance received by the engaging member 72 from the developer is further reduced, and the malfunction of the clutch portion 70 is further suppressed.

  As described above, by providing the clutch portion 70 inside the developer accommodating portion 15, it is possible to reduce the size of the apparatus while suppressing an increase in load torque due to aggregation of the developer. In particular, in this embodiment, by providing the clutch part 70 upstream of the developer conveying member 25 in the developer conveying direction J, the malfunction of the clutch part 70 is suppressed, and the clutch part 70 is surely connected to the developer conveying member 25. Can be cut off.

  Further, in this embodiment, the developer accommodating portion 15 and the developer conveying device 9 having the developer agitating member 24 provided in the developer accommodating portion 15, the developer conveying member 25, the sealing member 80, the clutch portion 70, and the like. Was adopted in the developing unit 10 of the process cartridge. On the other hand, in the developer supply cartridge, the same effect can be obtained by adopting the configuration of the developer transport device described above.

  Needless to say, the clutch unit 70 is not limited to the configuration of the present embodiment, and the same effect can be obtained by using a clutch of another configuration such as a torque limiter or a friction clutch.

2 Photosensitive drum 9 Developer transport device 11 Developing roller 15 Developer accommodating portion 15a First accommodating portion 15b Second accommodating portion 24 Developer stirring member 25 Developer conveying member 25a Slit 25b Cylindrical portion 25c, 25d Driven transmission surface 25e Spring receiving surface 32 Developing and conveying gear 32a First cylindrical portion 32b Cam surface 32c Second cylindrical portion 32d Apex 70 Clutch portion 71 Compression spring 72 Engaging member 72b Inner peripheral portion 72c, 72d Drive transmission portion 72e Spring receiving portion 120 Feeding unit 121 Feed tray 122 Feeding roller

Claims (9)

In the developer conveying device used in the image forming apparatus,
A developer accommodating portion for accommodating the developer;
A developer conveying member disposed inside the developer accommodating portion and conveying the developer by rotation;
A drive input unit to which a driving force for driving the developer conveying member is input;
A state in which a driving force is transmitted from the driving input unit to the developer conveying member, and a driving force necessary for rotating the developer conveying member exceeds a predetermined magnitude from the driving input unit to the developer. A clutch that can take a state in which the driving force is transmitted to the conveying member, and
With
The developer conveying device according to claim 1, wherein the clutch is attached to the inside of the developer accommodating portion.   2. The developer conveying device according to claim 1, wherein the clutch is disposed on the upstream side of the developer conveying member in a developer conveying direction in which the developer conveying member conveys the developer.   The clutch includes a movable member that is movable between a drive transmission position that transmits a driving force to the developer conveying member and a restriction position that restricts the transmission of the driving force to the developer conveying member, and the moving member The developer conveying device according to claim 1, further comprising an elastic member that urges the toner toward the drive transmission position. The drive input unit has a slope that engages with the moving member;
When the driving force necessary for rotating the developer conveying member exceeds a predetermined magnitude, the moving member moves from the drive transmission position to the restriction position along the slope. The developer conveying device according to claim 3.   The developer conveying device according to claim 3, wherein the moving member is provided with a through hole that allows the developer to pass when the moving member moves. An opening for discharging the developer from the developer container;
A sealing member attached to the opening and sealing the opening;
A removal member for removing the sealing member from the opening;
The developer conveying device according to claim 1, wherein the developer conveying device is provided. The developer container is divided into a first container and a second container,
The second accommodating portion is arranged with the developer conveying member and the clutch, and is connected to the first accommodating portion,
The speed of the developer that moves the second container when the developer transport member rotates is faster than the speed of the developer that moves the first container. The developer conveying apparatus of any one of Claims.   The developer conveying device according to claim 7, further comprising a developer stirring member that is disposed inside the first storage portion and stirs the developer by rotating. In a process cartridge detachable from an image forming apparatus,
An image carrier on which a latent image is formed;
A developer carrying member carrying a developer for developing the latent image;
The developer conveying device according to any one of claims 1 to 8,
A process cartridge comprising:

Images