JP2009116039A - Developing device, process cartridge, and electrophotographic image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a developing device capable of automatically unsealing a seal member which seals an opening of a toner storing container more inexpensively with simpler constitution in a small-space state, and to provide a process cartridge and an electrophotographic image forming apparatus. <P>SOLUTION: A torque limiter 62 is coupled with a stirring member 60. When torque for driving the stirring member while the opening of the toner storing container is sealed is defined as T<SB>2</SB>and torque for driving the stirring member while the opening is unsealed is defined as T<SB>2</SB>', transmissible maximum torque T<SB>1max</SB>of the torque limiter is set to T<SB>2</SB>>T<SB>1max</SB>>T<SB>2</SB>'. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an electrophotographic image forming apparatus, and also relates to a developing device and a process cartridge that can be used in the electrophotographic image forming apparatus.

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

  The process cartridge described above is a cartridge in which a charging unit, a developing unit, or a cleaning unit and an electrophotographic photosensitive member are integrally formed, and the cartridge can be attached to and detached from the image forming apparatus main body. In addition, at least one of charging means, developing means, and cleaning means and the electrophotographic photosensitive member are integrally formed into a cartridge so as to be detachable from the main body of the electrophotographic image forming apparatus. Further, it means that at least the developing means and the electrophotographic photosensitive member are integrated into a cartridge so that it can be attached to and detached from the electrophotographic image forming apparatus main body.

  In conventional image forming apparatuses using electrophotography, the electrophotographic photosensitive member can be replaced, the developer can be replenished or replaced, and other (charger, cleaner container, etc.) adjustments, cleanings, and replacements can be performed over a long period of time. Necessary. However, such maintenance work is practically difficult except for a service person having specialized knowledge.

  Therefore, in an image forming apparatus using an electrophotographic image forming process, a process in which an electrophotographic photosensitive member and process means acting on the photosensitive member are integrally formed into a cartridge so that the cartridge can be attached to and detached from the image forming apparatus main body. A cartridge system is adopted. According to this process cartridge system, since the apparatus can be maintained by the user himself / herself without depending on the service person, the operability can be remarkably improved. Therefore, this process cartridge system is widely used in electrophotographic image forming apparatuses.

  4 and 5 show an example of the image forming apparatus 100 including the electrophotographic image forming apparatus main body A and the process cartridge B. FIG.

  In the process cartridge B, a charging device (hereinafter referred to as “charging roller”) 20 and toner (developer) are disposed around a drum-shaped electrophotographic photosensitive member (hereinafter referred to as “photosensitive drum”) 10 as an image carrier. ) A developing device D containing T and a cleaning device C are disposed. Each device arranged around the photosensitive drum 10 is covered with a housing including a cleaning frame 90 and a toner container 70 to be integrated into a cartridge B, which is detachable from the image forming apparatus main body A.

  The developing device D will be further described. The toner container 70 is provided with an opening 70 a for supplying the toner T to the developing sleeve 40 at a position toward the developing sleeve 40 as a developing member. The opening 70a is sealed with a seal member, that is, a toner seal 71 in order to reliably prevent toner leakage during transportation, and is opened by a user performing a removal operation.

  A sleeve gear 41 is attached to one end of the developing sleeve 40 in the axial direction, and rotates integrally. The sleeve gear 41 meshes with the drum gear 11 of the photosensitive drum 10 and rotates the developing sleeve 40 according to the rotation of the photosensitive drum 10. A magnet roller 42 is included in the developing sleeve 40. Further, the sleeve gear 41 meshes with a stirring gear (not shown) connected to the stirring member 60 and transmits the rotational force of the photosensitive drum 10 to the stirring member 60.

  Here, the toner seal is unsealed by the driving force from the image forming apparatus main body, and in order to reduce the load on the image forming apparatus main body, the drive stirring member starts to rotate after the unsealing operation ends. (For example, refer to Patent Document 1). This configuration will be described below.

  The winding shaft of the toner seal having the drive gear is urged by a spring downward in the axial direction of the winding shaft, and the lower edge of the toner seal is supported by a stopper, so that the winding shaft resists the urging force. The position of is regulated. After the toner seal is taken up, the toner seal is removed from the stopper, and the take-up shaft is lowered by the biasing force of the spring. When the winding shaft moves, the drive gear and the agitation gear mesh with each other, and the agitation member is driven.

  Moreover, there exists a structure which interrupts | blocks the drive transmission of a stirring member when overload arises in the stirring member (for example, refer patent document 2). This configuration will be described below.

The stirring member is formed of a wire that is a single metal wire continuous with the rotation shaft. The wire has an arm portion for stirring and a coil portion for fixing to the rotating shaft. The coil portion has an inner diameter in a free state set smaller than an outer diameter of the rotating shaft, and is press-fitted into the rotating shaft. When the rotating shaft rotates, the arm portion of the wire receives the resistance force of the toner and receives a force in the direction in which the coil portion is loosened. Therefore, when the agitation member is overloaded, drive transmission to the arm portion can be interrupted.
JP 2001-134058 A Japanese Patent Publication No. 8-20801

  The present invention is a further development of the prior art.

  SUMMARY OF THE INVENTION An object of the present invention is to provide a developing device, a process cartridge, and an electrophotographic apparatus that automatically open a sealing member that seals the opening of a toner container in a small space with a simpler structure and at a lower cost. An object is to provide an image forming apparatus.

The above object is achieved by the developing device, the process cartridge, and the electrophotographic image forming apparatus according to the present invention. In summary, according to the first aspect of the present invention, in a developing device used in an electrophotographic image forming apparatus,
A developing member for developing the electrostatic latent image formed on the electrophotographic photosensitive member using a developer;
A toner container that contains the developer and has an opening for supplying the developer to the developing member;
A sealing member for sealing the opening;
A seal member opening means for removing the seal member and opening the opening by using a driving force from an apparatus main body of the electrophotographic image forming apparatus;
An agitating member for agitating the developer contained in the toner container;
A drive input unit that receives the driving force and transmits the driving force to the seal member opening means and the stirring member;
A torque limiter coupled to the stirring member and having a maximum transmittable torque of T _1max ;
Have
When the torque for driving the stirring member in a state where the opening is sealed is T ₂ , and the torque for driving the stirring member in a state where the opening is opened is T ₂ ′,
There is provided a developing device characterized in that T ₂ > T _1max > T ₂ ′.

According to the second aspect of the present invention, in the process cartridge detachable from the electrophotographic image forming apparatus main body,
An electrophotographic photoreceptor;
A developing member for developing the electrostatic latent image formed on the electrophotographic photosensitive member using a developer;
A toner container that contains the developer and has an opening for supplying the developer to the developing member;
A sealing member for sealing the opening;
A seal member opening means for removing the seal member and opening the opening by using a driving force from an apparatus main body of the electrophotographic image forming apparatus;
An agitating member for agitating the developer contained in the toner container;
A drive input unit that receives the driving force and transmits the driving force to the seal member opening means and the stirring member;
A torque limiter coupled to the stirring member and having a maximum transmittable torque of T _1max ;
Have
When the torque for driving the stirring member in a state where the opening is sealed is T ₂ , and the torque for driving the stirring member in a state where the opening is opened is T ₂ ′,
There is provided a process cartridge characterized by T ₂ > T _1max > T ₂ ′.

According to a third aspect of the present invention, in an electrophotographic image forming apparatus for forming an image on a recording medium,
(A) an electrophotographic photoreceptor;
(B) a developing member for developing the electrostatic latent image formed on the electrophotographic photosensitive member using a developer;
A toner container that contains the developer and has an opening for supplying the developer to the developing member;
A sealing member for sealing the opening;
A seal member opening means for removing the seal member and opening the opening by using a driving force from an apparatus main body of the electrophotographic image forming apparatus;
An agitating member for agitating the developer contained in the toner container;
A drive input unit that receives the driving force and transmits the driving force to the seal member opening means and the stirring member;
A torque limiter coupled to the stirring member and having a maximum transmittable torque of T _1max ;
Have
When the torque for driving the stirring member in a state where the opening is sealed is T ₂ , and the torque for driving the stirring member in a state where the opening is opened is T ₂ ′,
A developing device _satisfying T ₂ > T _1max > T ₂ ′;
(C) conveying means for conveying the recording medium;
An electrophotographic image forming apparatus is provided.

According to the present invention, the maximum torque T _1max that can be transmitted by the torque limiter is _set to T ₂ > T _1max > T ₂ ′, so that the stirring member is opened to the stirring member with a time difference after the opening of the seal member starts. Drive can be transmitted. Accordingly, it is possible to disperse the large driving force applied at the start of the seal member opening operation and the large driving force applied when the stirring member is rotated in the initially pressed developer. Therefore, the motor can be configured with a motor having a small torque and a small electric capacity, and the strength required for a driving force transmission member such as a gear can be kept small. Therefore, the developing device, the process cartridge, and the image forming apparatus can be reduced in size with a simple configuration at low cost.

  Hereinafter, a developing device, a process cartridge, and an electrophotographic image forming apparatus according to the present invention will be described in more detail with reference to the drawings.

  In the following description, the short direction of the process cartridge is a direction in which the process cartridge is attached to and detached from the apparatus main body, and coincides with the conveyance direction of the recording medium. The longitudinal direction of the process cartridge is a direction (substantially orthogonal) that intersects with the direction in which the process cartridge is attached to and detached from the apparatus main body, is substantially parallel to the surface of the recording medium, and the conveyance direction of the recording medium. Crossing direction.

Example 1
Hereinafter, embodiments of a developing device, a process cartridge, and an electrophotographic image forming apparatus according to the present invention will be described.

  The developing device, process cartridge, and electrophotographic image forming apparatus of the present embodiment can be configured in the same manner as the conventional one described with reference to FIGS. Accordingly, a schematic configuration of the developing device, the process cartridge, and the electrophotographic image forming apparatus of the present embodiment will be described with reference to FIGS. FIG. 1 is a perspective view showing a schematic configuration of a seal member unsealing means (toner seal unsealing mechanism) 200 constituting a characteristic part of the present invention.

(overall structure)
Referring to FIG. 4, the electrophotographic image forming apparatus 100 of the present embodiment is a laser printer, and the process cartridge B is detachably attached to the apparatus main body A by a mounting means (not shown). Therefore, when the process cartridge B is mounted on the apparatus main body A, an image is formed on the recording medium (sheet material) 1 (for example, recording paper, OHP sheet, cloth, etc.) by the electrophotographic image forming process.

  The surface of the photosensitive drum 10 is uniformly charged by the charging roller 20. The photosensitive drum 10 is irradiated with laser light L corresponding to image information from the exposure device (laser scanner unit) 2 to form a latent image corresponding to the image information on the photosensitive drum 10. The latent image formed on the photosensitive drum 10 is developed by the developing device D to be a toner image.

  On the other hand, in synchronization with the formation of the toner image, the recording medium 1 set on the sheet tray 3 includes a pickup (paper feed) roller 4a, a feed (conveyance) roller pair 4b, a registration roller pair 4c, which constitute a recording medium conveyance unit. And is conveyed along the transfer guide 5. Next, it passes through a nip formed by the photosensitive drum 10 and the transfer roller 6 to which a constant voltage is applied. At this time, the toner image developed on the photosensitive drum 10 is transferred to the recording medium 1.

  The recording medium 1 that has received the transfer of the toner image is conveyed to the fixing device 8 by the conveyance guide 7. The fixing device 8 includes a driving roller 8a and a heater 8b, and fixes the transferred toner image by applying heat and pressure to the recording medium 1 passing through the nip portion. Thereafter, the recording medium 1 is conveyed and discharged by the discharge roller pair 4d via the reverse conveying guide that also constitutes the recording medium conveying means, and is discharged to the discharge tray 9 with the printing surface facing downward.

(Process cartridge)
As described above, the process cartridge B integrally accommodates four types of process devices, ie, the photosensitive drum 10, the charging roller 20, the developing device D, and the cleaning device C, as can be understood with reference to FIG. is doing.

  In the cleaning device C of the process cartridge B, a photosensitive drum 10 for forming an electrostatic latent image, a charging roller 20 for uniformly charging the surface of the photosensitive layer, and a cleaning blade 30 are arranged. The cleaning blade 30 scrapes residual toner adhering to the photosensitive drum 10 without being transferred onto the transfer paper from the surface of the photosensitive drum 10 and stores it in the waste toner container 90.

  In the present embodiment, the developing device D is provided with a toner container 70 that contains a magnetic one-component developer (toner) T substantially composed of magnetic resin toner particles (may contain an external additive). ing. In the toner container 70, a developing sleeve 40 is disposed as a developing member for supplying toner T to the electrostatic latent image formed on the photosensitive drum 10 to form a visible image. Further, the developing device D imparts a triboelectric charge to the toner T, and forms a toner layer on the surface of the developing sleeve 40 (hereinafter referred to as “developing blade”) 50, and a toner container An agitating member 60 for agitating and conveying the toner T in the toner 70 is provided. Further, in the developing device D, an ejection preventing sheet 72 for preventing toner leakage is disposed in the lower opening of the toner container 70 where the developing sleeve 40 is disposed.

  The developing device D and the cleaning device C are integrally coupled by covers (not shown) provided at both ends in the longitudinal direction of the process cartridge B.

(Description of image forming process)
As shown in FIG. 5, the photosensitive drum 10 is rotationally driven from the apparatus main body A in the arrow R direction. A constant voltage is applied to the charging roller 20, and when the photosensitive drum 10 comes into contact, the surface of the photosensitive layer of the contacting photosensitive drum 10 is uniformly charged. Next, a laser beam L corresponding to the image information from the exposure device 2 is irradiated onto the photosensitive drum 10 through the exposure opening 90 a to form an electrostatic latent image on the photosensitive drum 10. Thereafter, a toner image is formed on the photosensitive drum 10 by the developing device D.

  The developing device D sends out the toner T in the toner container 70 to the developing sleeve 40 by the rotation of the stirring member 60. Then, the developing sleeve 40 incorporating the fixed magnet 42 is rotated, and a toner layer imparted with triboelectric charge by the developing blade 50 is formed on the surface of the developing sleeve 40.

  The developing sleeve 40 is pressed against the photosensitive drum 10 by an urging spring (not shown) while maintaining a certain clearance with respect to the photosensitive drum 10 by a spacer roller 43 (see FIG. 1), and the toner formed on the surface. The layer is supplied to the development area of the photosensitive drum 10. A toner image is formed by transferring the toner T to the photosensitive drum 10 in accordance with the electrostatic latent image. Here, the developing blade 50 defines the amount of toner on the peripheral surface of the developing sleeve 40 and imparts a triboelectric charge.

  A voltage having a polarity opposite to that of the toner image is applied to a transfer roller 6 serving as transfer means provided in the image forming apparatus main body A, and the toner image formed on the photosensitive drum 10 is transferred to the recording medium 1. Thereafter, residual toner on the photosensitive drum 10 is scraped off by the cleaning blade 30 and collected in the waste toner container 90.

(Toner seal opening mechanism)
With reference to FIG. 1, a seal member opening means (toner seal opening mechanism) 200 in this embodiment will be described.

  The opening 70a of the toner container 70 is sealed with a seal member, that is, a thin sheet toner seal 71 in a new state before use.

  As shown in FIG. 1, a drum gear 11 that rotates integrally with the photosensitive drum 10 is disposed at one end of the photosensitive drum 10, and a sleeve that rotates integrally with the developing sleeve 40 is disposed at one end of the developing sleeve 40. A gear 41 is arranged. The sleeve gear 41 meshes with the drum gear 11.

  Further, a bevel gear 81a and a bevel gear 81b are formed at both ends of the take-up shaft 81 coupled to one end of the toner seal 71. The bevel gear 80a and the idler gear 82 formed on the idler gear 80, respectively. Meshed with a bevel gear 82a formed on the surface.

  A gear 80 b integrally formed coaxially with the bevel gear 80 a on the idler gear 80 meshes with the sleeve gear 41.

On the other hand, a stirring gear 61 that transmits drive to the stirring member 60 is attached to the stirring member 60 via a torque limiter 62 whose maximum transmittable torque between the stirring gear 61 and the stirring member 60 is T _1max . The agitation gear 61 meshes with a gear 83a of a step gear 83 composed of gears 83a and 83b. The gear 83b of the step gear 83 meshes with a gear 82b that is integrally formed coaxially with the bevel gear 82a of the idler gear 82.

  That is, the driving force of the drum gear 11 acting as a drive input unit for the winding shaft 81 and the stirring member 60 is transmitted to the winding shaft 81 and the stirring member 60 via the gear train that constitutes the driving force transmission path. That is, the driving force of the drum gear 11 is agitated via the idler gear 80, the winding shaft 81, the idler gear 82, the step gear 83, the agitation gear 61, and the torque limiter 62 sequentially from the sleeve gear 41 meshed with the drum gear 11. It is transmitted to the member 60.

  Various known torque limiters 62 can be used as the torque limiter 62. For example, a spring type torque limiter can be preferably used.

  A spring type torque limiter will be described.

  The spring type torque limiter includes a housing having an input shaft, a coil spring having one end fixed to the housing, and an output shaft press-fitted and supported in the inner diameter portion of the coil spring.

  The winding direction of the coil spring is set so that when the input shaft rotates, the inner diameter increases due to the frictional force with the output shaft. Therefore, up to the maximum torque that can be transmitted by the torque limiter, the input shaft and the output shaft can be rotated together by the frictional force between the coil spring inner diameter portion and the output shaft. However, when a torque greater than the maximum torque that can be transmitted is required for the rotation of the output shaft, the inner diameter of the spring increases and the coil spring and the output shaft idle. That is, the rotation of the input shaft is not transmitted to the output shaft.

  Here, when the opening 70a (see FIG. 5) is sealed, the toner T has a large resistance to the driving of the stirring member 60. On the other hand, when the winding shaft 81 rotates and winds up the toner seal 71 to sufficiently open the opening 70a, the toner T flows into the space E shown in FIG. Decreases.

The torque for driving the stirring member 60 in a state where the opening 70a is sealed is T ₂ , and the torque for driving the stirring member 60 in a state where the toner seal 71 is wound up and the opening is completely opened is T ₂ ′. Then, the maximum transmittable torque T _1max of the torque limiter 62 is set to T ₂ > T _1max > T ₂ ′.

As described above, the torque limiter 62 having the maximum transmittable torque T _1max is provided between the stirring gear 61 and the stirring member 60. Therefore, in a state where the opening 70 a is sealed, the torque T ₂ necessary for driving the stirring member 60 is larger than the maximum transmittable torque T _{1max of} the torque limiter 62, so the stirring member 60 does not rotate. On the other hand, in a state where the opening 70a is sufficiently opened, the torque T ₂ ′ required for driving the stirring member 60 is smaller than the maximum transmittable torque T _{1max of the} torque limiter 62, so that the drive is transmitted to the stirring member 60. Rotate.

  Conventionally, a large driving force required when starting the toner seal opening operation and a large driving force required when rotating the agitating member 60 in the initially pressed toner have been required at the same time. Therefore, it is necessary to provide a motor having a large torque and a large electric capacity, and it is necessary to increase the strength of a driving force transmission member such as a gear.

  Further, in order to avoid the above problem, it is necessary to provide a special mechanism when driving is transmitted to the stirring member 60 with a time difference after the opening 70a starts to be opened.

In this embodiment, in order to solve the above-described problem, a torque limiter 62 having a maximum transmittable torque T _1max of T ₂ > T _1max > T ₂ ′ is provided between the stirring gear 61 and the stirring member 60. As a result, in a state where the opening 70a is sealed and the toner T has a large resistance to the driving of the stirring member 60, the stirring member 60 does not rotate, and the torque applied to the motor does not increase to any extent. _{It can} be suppressed to _1max . Then, when the opening 70a is sufficiently opened, the toner T flows into the space E and the resistance of the toner T with respect to the driving of the stirring member 60 decreases, and then the drive is transmitted to the stirring member 60 and rotates. Is possible.

As described above, in the first embodiment of the present invention, the torque limiter 62 having the maximum transmittable torque T _1max of T ₂ > T _1max > T ₂ ′ is provided between the stirring gear 61 and the stirring member 60. As a result, in a state where the opening 70a is sealed and the toner T has a large resistance to the driving of the stirring member 60, the stirring member 60 does not rotate, and the torque applied to the motor does not increase to any extent, and T _1max is always _obtained. Can be suppressed. Then, when the opening 70a is sufficiently opened, the toner T flows into the space E, and the resistance of the toner T with respect to the driving of the stirring member 60 is reduced. Then, the drive is transmitted to the stirring member 60 and rotates. It was possible.

  Further, since the drive transmission with the time difference as described above is possible, when the stirring member 60 is rotated in the large amount of driving force applied at the start of the toner seal opening operation and in the initial state of the pressed toner. Such a large driving force can be dispersed. Therefore, the motor can be configured with a motor having a small torque and a small electric capacity, and the strength required for a driving force transmission member such as a gear can be kept small.

  As a result, the process cartridge can be reduced in size as well as reduced in cost with a simple configuration.

Example 2
A second embodiment of the present invention will be described with reference to FIGS. FIG. 2 shows a seal member opening means (toner seal opening mechanism) 200 in this embodiment. Elements having the same configuration and function as those of the first embodiment or elements corresponding to those of the first embodiment are denoted by the same reference numerals, and detailed description thereof is omitted. The same applies to the following embodiments.

  In the present embodiment, the drive transmission path is different. As shown in FIG. 2, on one side surface of the toner container 70, a drum gear 11 that is disposed at one end of the photosensitive drum 10 and rotates integrally with the photosensitive drum 10, and a developing sleeve disposed at one end of the developing sleeve 40. A sleeve gear 41 that rotates integrally with 40 is disposed. The sleeve gear 41 meshes with a gear 80 b of an idler gear 80 having a bevel gear 80 a, and the bevel gear 80 a meshes with a bevel gear 81 a formed on a winding shaft 81 coupled to one end of the toner seal 71. . This configuration is the same as in the first embodiment.

In the present embodiment, the idler gear 80 meshes with the gear 83b of the step gear 83, and the gear 83a of the step gear 83 meshes with the stirring gear 61 that transmits the drive to the stirring member 60, as in the first embodiment. . As in the first embodiment, a torque limiter 62 having a maximum transmittable torque T _1max of T ₂ > T _1max > T ₂ ′ is provided between the stirring gear 61 and the stirring member 60.

  That is, the driving force of the drum gear 11 acting as a drive input unit is transmitted from the sleeve gear 41 meshed with the drum gear 11 to the idler gear 80 and the take-up shaft 81 sequentially. On the other hand, the driving force from the idler gear 80 is transmitted to the stirring member 60 via the step gear 83, the stirring gear 61, and the torque limiter 62 without passing through the winding shaft 81.

Thus, as in the first embodiment, in the state where the opening 70a is sealed and the toner T has a large resistance to the driving of the stirring member 60, the stirring member 60 does not rotate and the torque applied to the motor increases to any extent. There is no need to do so, and T _1max is always suppressed. When the opening 70a is sufficiently opened, the toner T flows into the space E (development chamber) shown in FIG. 5 and the resistance of the toner T with respect to the driving of the stirring member 60 is reduced. Can be transmitted and rotated.

  In addition, since the drive transmission with a time difference is possible as in the first embodiment, the agitation member 60 is rotated in the large amount of driving force applied at the start of the toner seal opening operation and in the initially pressed toner. It is possible to disperse the large driving force required. Therefore, the motor can be configured with a motor having a small torque and a small electric capacity, and the strength required for a driving force transmission member such as a gear can be kept small.

  In addition to the first embodiment, the process cartridge can be made not only inexpensive with a simpler structure, but also contributes to miniaturization.

Example 3
A third embodiment of the present invention will be described with reference to FIG. In this embodiment, the torque limiter 62 performs drive transmission using viscosity.

  The torque limiter 62 includes an input shaft 63 having a disk portion 63a and an output shaft 64 having a housing portion 64a provided so as to surround the disk portion 63a. The input shaft 63 and the output shaft 64 are rotatably provided on the same axis, and the input shaft 63 projects outwardly from the opening 64b formed in the housing portion 64a to the opposite side of the output shaft 64. ing.

  Oil OL is sealed in the housing portion 64a. In order to prevent oil leakage from between the input shaft 63 and the opening 64b of the housing portion 64a, an oil seal 65 is disposed between the input shaft 63 and the housing portion 64a.

  With the above configuration, when the input shaft 63 rotates, the drive is transmitted to the output shaft 64 due to the viscosity of the oil OL interposed between the input shaft 63 and the output shaft 64.

  In this configuration, the difference in rotational speed between the input shaft 63 and the output shaft 64 is small when the load on the output shaft 64 is small, and the rotational speed difference between the input shaft 63 and the output shaft 64 is small when the load on the output shaft 64 is large. growing. The maximum torque that can be transmitted is determined by the rotational speed of the input shaft 63, and the maximum torque is generated when the difference in rotational speed is maximum, that is, when the rotational speed of the output shaft 64 is zero.

In this embodiment, the rotational speed of the input shaft 63 is fixed, and the maximum torque that can be transmitted at this rotational speed is T _1max as in the first and second embodiments, so that T ₂ > T _1max > T ₂ ′. Set.

  In this configuration, as in the first embodiment, the stirring member 60 does not rotate in a state where the opening 70 a is sealed and the toner T has a large resistance to the driving of the stirring member 60. On the other hand, when the opening 70a is sufficiently opened, the toner T flows into the space E, and the resistance of the toner T with respect to the driving of the stirring member 60 is reduced. Then, the drive is transmitted to the stirring member 60 and rotates. It was possible.

  In addition, since the drive transmission with a time difference is possible as in the first embodiment, the agitation member 60 is rotated in the large amount of driving force applied at the start of the toner seal opening operation and in the initially pressed toner. It is possible to disperse the large driving force required. Therefore, the motor can be configured with a motor having a small torque and a small electric capacity, and the strength required for a driving force transmission member such as a gear can be kept small.

  In the same manner as in the first embodiment, the process cartridge can be made not only cheaper with a simpler structure, but also contributes to downsizing.

  Further, since the torque limiter 62 performs drive transmission using viscosity, it is possible to suppress torque fluctuations and vibrations when the stirring member 60 is driven to the drive transmission member such as the drum gear 11. Can be reduced.

  In the above description of each embodiment, the case where the present invention is applied to a process cartridge has been described. However, a developing device alone (developing cartridge) and a process cartridge system that are not integrated with a photosensitive drum or the like are used. The present invention can also be applied to image forming apparatuses that do not.

FIG. 3 is a perspective view illustrating a configuration of an embodiment of a toner seal opening mechanism according to the present invention. It is a perspective view explaining the structure of the other Example of the toner seal opening mechanism in this invention. It is a schematic block diagram explaining the other Example of the torque limiter in this invention. 1 is a schematic cross-sectional view of an embodiment of an image forming apparatus to which the present invention is applied. It is a schematic structure sectional view of one example of a process cartridge to which the present invention is applied.

Explanation of symbols

1 Recording medium 2 Laser scanner unit (exposure device)
10 Photosensitive drum (electrophotographic photosensitive member)
11 Drum gear (drive input part)
20 Charging roller (charging device)
40 Development sleeve (developer carrier)
41 Sleeve gear 42 Fixed magnet (magnetic field generating means)
50 Development blade (developer regulating member)
60 Stirring member 61 Stirring gear 62 Torque limiter 63 Input shaft 63a Disk portion 64 Output shaft 64a Housing portion 65 Oil seal 70 Toner container 70a Opening 71 Toner seal (seal member)
200 Toner seal opening mechanism (sealing member opening means)
A Image forming apparatus body (apparatus body)
B Process cartridge C Cleaning device D Developer

Claims (12)

In a developing device used in an electrophotographic image forming apparatus,
A developing member for developing the electrostatic latent image formed on the electrophotographic photosensitive member using a developer;
A toner container that contains the developer and has an opening for supplying the developer to the developing member;
A sealing member for sealing the opening;
A seal member opening means for removing the seal member and opening the opening by using a driving force from an apparatus main body of the electrophotographic image forming apparatus;
An agitating member for agitating the developer contained in the toner container;
A drive input unit that receives the driving force and transmits the driving force to the seal member opening means and the stirring member;
A torque limiter coupled to the stirring member and having a maximum transmittable torque of T _1max ;
Have
When the torque for driving the stirring member in a state where the opening is sealed is T ₂ , and the torque for driving the stirring member in a state where the opening is opened is T ₂ ′,
A developing device characterized in that T ₂ > T _1max > T ₂ ′.   The developing device according to claim 1, wherein the torque limiter is provided in a driving force transmission path between the driving input unit and the stirring member.   The developing device according to claim 1, wherein the torque limiter is provided in a driving force transmission path between the seal member opening unit and the stirring member.   The developing device according to claim 1, wherein the torque limiter transmits driving using viscosity. In a process cartridge that can be attached to and detached from the electrophotographic image forming apparatus main body,
An electrophotographic photoreceptor;
A developing member for developing the electrostatic latent image formed on the electrophotographic photosensitive member using a developer;
A toner container that contains the developer and has an opening for supplying the developer to the developing member;
A sealing member for sealing the opening;
A seal member opening means for removing the seal member and opening the opening by using a driving force from an apparatus main body of the electrophotographic image forming apparatus;
An agitating member for agitating the developer contained in the toner container;
A drive input unit that receives the driving force and transmits the driving force to the seal member opening means and the stirring member;
A torque limiter coupled to the stirring member and having a maximum transmittable torque of T _1max ;
Have
When the torque for driving the stirring member in a state where the opening is sealed is T ₂ , and the torque for driving the stirring member in a state where the opening is opened is T ₂ ′,
A process cartridge characterized by T ₂ > T _1max > T ₂ ′.   The process cartridge according to claim 5, wherein the torque limiter is provided in a driving force transmission path between the driving input unit and the stirring member.   6. The process cartridge according to claim 5, wherein the torque limiter is provided in a driving force transmission path between the seal member opening means and the stirring member.   8. The process cartridge according to claim 5, wherein the torque limiter transmits driving using viscosity. In an electrophotographic image forming apparatus for forming an image on a recording medium,
(A) an electrophotographic photoreceptor;
(B) a developing member for developing the electrostatic latent image formed on the electrophotographic photosensitive member using a developer;
A toner container that contains the developer and has an opening for supplying the developer to the developing member;
A sealing member for sealing the opening;
A seal member opening means for removing the seal member and opening the opening by using a driving force from an apparatus main body of the electrophotographic image forming apparatus;
An agitating member for agitating the developer contained in the toner container;
A drive input unit that receives the driving force and transmits the driving force to the seal member opening means and the stirring member;
A torque limiter coupled to the stirring member and having a maximum transmittable torque of T _1max ;
Have
When the torque for driving the stirring member in a state where the opening is sealed is T ₂ , and the torque for driving the stirring member in a state where the opening is opened is T ₂ ′,
A developing device _satisfying T ₂ > T _1max > T ₂ ′;
(C) conveying means for conveying the recording medium;
An electrophotographic image forming apparatus comprising:   The electrophotographic image forming apparatus according to claim 9, wherein the torque limiter is provided in a driving force transmission path between the driving input unit and the stirring member.   The electrophotographic image forming apparatus according to claim 9, wherein the torque limiter is provided in a driving force transmission path between the seal member opening unit and the stirring member.   12. The electrophotographic image forming apparatus according to claim 9, wherein the torque limiter transmits driving using viscosity.

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