JP5585881B2 - Developing device, process cartridge, and image forming apparatus - Google Patents

Description

  The present invention relates to a developing device having a toner scattering prevention structure used in an image forming apparatus such as a copying machine, a FAX, and a printer, a process cartridge including the developing device, and an image forming apparatus including any of these. It is.

  2. Description of the Related Art Conventionally, a developing device that visualizes a latent image formed on a latent image agent carrier with a developing device is known. For example, there is a two-component developing device using a two-component developer composed of a toner and a carrier as a developer in order to visualize a latent image formed on a photoconductor as a latent image agent carrier. In this two-component developing device, a toner is supplied by bringing a magnetic brush of a developing roller, which is a developer carrying member, into contact with a photosensitive member, and is attached to a latent image on the photosensitive member to form a visible image. Then, a phenomenon occurs in which part of the toner supplied from the developer magnetic brush scatters to the outside without adhering to the photoconductor in the development area (hereinafter referred to as toner scattering), and internal contamination caused by the scattered toner. In addition, it is known that problems such as abnormal images occur.

  Therefore, conventionally, a flexible sealing member called an entrance seal is generally arranged on the upstream side in the rotation direction of the magnetic brush in the vicinity of the developing area between the photosensitive member and the developing roller, and the toner is scattered by blocking. A structure for reducing the above is known. For example, Patent Document 1 describes a configuration in which a unit including a flexible entrance seal is movably supported so that the amount of contact of the entrance seal with the photosensitive member can be adjusted to an appropriate range. ing. By setting the amount of contact of the entrance seal to the photoconductor within an appropriate range, it is possible to prevent toner from scattering from the upstream side of the developing region in the photoconductor rotation direction, and to cause a problem that the amount of contact exceeds the appropriate range. It is to suppress. Japanese Patent Application Laid-Open No. 2004-228561 describes a configuration that uses a U-shaped inlet seal and eliminates a gap between the photoreceptor and the inlet seal without requiring high processing accuracy and installation accuracy. Without requiring high processing accuracy and installation accuracy, the entire contact portion of the inlet seal is always brought into contact with the photosensitive member to eliminate the gap between the inlet seal and the photosensitive member, and from the upstream side of the developing region in the photosensitive member rotation direction. This prevents the toner from scattering.

  However, the toner scattered from within the developing area accumulates on the entrance seal, and the toner accumulated on the entrance seal increases and accumulates. Then, there is a problem that the toner accumulated on the entrance seal is adsorbed (developed) to the photoconductor by the potential of the photoconductor and causes an abnormal image such as a background stain or a toner drop image. Neither of the above-mentioned Patent Documents 1 and 2 has a configuration for solving the problem of abnormal images caused by toner deposited on the entrance seal. In addition, toner scattering has been increasing due to the recent trend toward smaller particle size of toner due to demands for higher speed image forming devices and higher image quality, and longer life due to the demand for high durability. The problem of abnormal images due to toner accumulation has become apparent.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a developing device that can prevent toner accumulation on the inlet seal and prevent the occurrence of abnormal images over a long period of time.

In order to achieve the above object, the invention described in claim 1 is provided with a flexibility for suppressing toner scattered from a developer carrying member, and a developing area where the latent image carrying member and the developer carrying member face each other. A developing device for developing a latent image formed on the latent image carrier with a two-component developer composed of toner and a carrier, wherein the sealing member is attached to a case of the developing device. is supported in a movable state, both also of the latent image bearing member and said developer carrying member, Ri alternatively contactable der moves, during the image forming contact to said latent image bearing member , in conjunction with reverse rotation of the developer carrier, and is characterized in contact to Rukoto to the developer carrier.
The invention of a process cartridge according to claim 2, at least the latent image bearing member, a charging device, with any of the cleaning device, the process cartridge comprising a developing apparatus, as the developing device, according to claim 1 A developing device is provided.
According to a third aspect of the present invention, there is provided an image forming apparatus including the developing device according to the first aspect as a developing device.
According to a fourth aspect of the present invention, there is provided an image forming apparatus comprising the process cartridge according to the second aspect as a process cartridge of the image forming unit.
In the present invention, since the seal member can be moved and selectively brought into contact with either the latent image carrier or the developer carrier, the latent image carrier or the developer carrier is interlocked with the operation of the developing device. It is possible to select either of them and move the seal member to contact. Accordingly, the scattered toner accumulated on the seal member in a state where the seal member is in contact with the latent image carrier is brought into contact with the developer carrier at a predetermined timing such as when image formation is completed. It is also possible to collect in the apparatus. Therefore, the toner accumulated on the seal member is collected in the developing device by bringing the seal member into contact with the developer carrying member, thereby preventing toner accumulation on the seal member. That is, the toner accumulated on the inlet seal can be collected in the developing device by bringing the inlet seal into contact with the developer carrying member, thereby preventing toner accumulation on the inlet seal.
In addition, the contact of the inlet seal with the developer carrier is interlocked with the reverse rotation drive of the developer carrier that is performed at a predetermined timing such as when image formation is completed. It can be brought into contact with the developer carrying member. As a result, a low-cost configuration can be achieved, and the developing device can be prevented from becoming large, and the accumulation of scattered toner on the entrance seal can be prevented, and abnormal images can be prevented from being generated over a long period of time.

  In the present invention, the scattered toner accumulated on the inlet seal can be collected in the developing device by bringing the inlet seal into contact with the developer carrying member. Therefore, it is possible to provide a developing device that can prevent toner accumulation on the inlet seal and prevent the occurrence of abnormal images over a long period of time.

1 is an overall configuration diagram of an image forming apparatus according to an embodiment. FIG. 3 is an explanatory diagram of an image forming unit of the image forming apparatus according to the present embodiment. FIG. 3 is an explanatory diagram of a state where an entrance seal is in contact with a photosensitive drum. FIG. 4 is an explanatory diagram of a state where an entrance seal is in contact with a developing roller.

  Hereinafter, as an example of an embodiment in which the present invention is applied to an image forming apparatus, an example in which the present invention is applied to an intermediate transfer tandem type full-color printer will be described with reference to the drawings. FIG. 1 is an overall configuration diagram of an image forming apparatus according to the present embodiment, and FIG. 2 is an explanatory diagram of an image forming unit of the image forming apparatus according to the present embodiment. FIG. 3 is an explanatory view showing a state where the entrance seal is in contact with the photosensitive drum, and FIG. 4 is an explanatory view showing a state where the entrance seal is in contact with the photosensitive drum.

  First, an outline of the printer 100 will be described with reference to FIG. The printer 100 is conveyed from the upper part of the main body to a stack unit 30 on which the image-formed transfer material P is stacked, a discharge roller pair 29 that discharges the transfer material P to the stack unit 30, and a discharge roller pair 29. A fixing unit 20 for fixing the transfer material P to be transferred is provided. A toner replenishing device 31 is provided on the left side of the fixing unit 20 in FIG. 1, and an intermediate transfer unit 15 is provided below the fixing unit 20 and the toner replenishing device 31, and the right side of the intermediate transfer unit 15 in FIG. Is provided with a secondary transfer roller 19. Below the intermediate transfer unit 15, four image forming units 6Y, 6M, 6C, and 6K corresponding to the respective colors (yellow, magenta, cyan, and black) are provided. An exposure unit 7 for irradiating L is provided. Below the exposure unit 7, two paper feeding units 26 for stacking and accommodating the transfer material P are provided. From the right side of the paper feeding unit 26 in FIG. 1, the secondary transfer roller 19 and the fixing unit 20 are passed through. Thus, a transport path for transporting the transfer material P to the paper discharge roller pair 29 is provided.

  In the toner supply device 31, four toner cartridges (toner containers) 32Y, 32M, 32C, and 32K corresponding to the respective colors (yellow, magenta, cyan, and black) are detachably (replaceable). A portion other than the toner cartridge in the toner replenishing device 31 is a toner conveying device that conveys toner, which is a powdery image forming agent, discharged from the toner cartridge to a developing device, which will be described later.

  The fixing unit 20 includes a heating and pressing type fixing device that fixes the color image transferred to the surface of the transfer material P by heat and pressure generated by the fixing roller and the pressure roller.

  The intermediate transfer unit 15 includes an intermediate transfer belt 8 as an intermediate transfer member, four primary transfer bias rollers 9Y, M, C, and K, a secondary transfer backup roller 12, a cleaning backup roller 13, a tension roller 14, and the like. Has been. A belt cleaning device 10 as an intermediate transfer cleaning unit is also provided.

  The secondary transfer roller 19 faces the secondary transfer backup roller 12 via the intermediate transfer belt 8 of the intermediate transfer unit 15 described above.

  The image forming units 6Y, 6M, 6C, and 6K corresponding to the respective colors are arranged in parallel so as to face the intermediate transfer belt 8 of the intermediate transfer unit 15 described above. Here, the image forming units 6Y, 6M, 6C, and 6K have the same configuration and operation except for the color of the toner used. Therefore, in the following description, the symbols Y, M, C, and K are appropriately used. The description is omitted.

  As shown in FIG. 2, the image forming unit 6 includes a photosensitive drum 1 as a latent image carrier, a charging device 4 provided around the photosensitive drum 1, a developing device 5 (developing unit), and a photosensitive member. The cleaning device 2 and a charge removal unit (not shown) are included. Then, an image forming process (charging process, exposure process, developing process, transfer process, cleaning process) is performed on the photosensitive drum 1, and a toner image is formed on the photosensitive drum 1.

  The photosensitive drum 1 is rotationally driven in a clockwise direction in FIG. 2 by a drive motor (not shown). Then, the surface of the photosensitive drum 1 is uniformly charged at the charging position by the charging device 4 (“charging process”). Thereafter, the surface of the photosensitive drum 1 reaches the irradiation position of the laser beam L irradiated from the exposure unit 7 (see FIG. 1), and an electrostatic latent image is formed by exposure scanning at this position (“exposure process”). "). Specifically, the exposure unit 7 emits a laser beam L from a light source, and scans the laser beam L with a polygon mirror, which is a rotationally driven rotary polygon mirror, on a photosensitive drum via a plurality of optical elements. Irradiate. After that, the photosensitive drum 1 and the developing roller 51 of the developing device 5 reach a developing region where the photosensitive drum 1 and the developing roller 51 are opposed to each other, and the electrostatic latent image is visualized by attaching the toner (“developing step”).

  Thereafter, the surface of the photoconductor drum 1 reaches a position facing the photoconductor cleaning device 2. At this position, the untransferred toner remaining on the photosensitive drum 1 is mechanically scraped and collected by the cleaning blade 2a (“cleaning process”). Finally, the surface of the photoconductive drum 1 reaches a position facing a static eliminating unit (not shown), and the residual potential on the photoconductive drum 1 is removed at this position. In this way, a series of image forming processes performed on the photosensitive drum 1 is completed.

  The intermediate transfer belt 8 is stretched and supported by the three rollers 12 to 14 and is endlessly moved in the direction of the arrow in FIG. The four primary transfer bias rollers 9Y, 9M, 9C, and 9K respectively sandwich the intermediate transfer belt 8 with the photosensitive drums 1Y, 1M, 1C, and 1K to form a primary transfer nip. A transfer bias having a polarity opposite to the polarity of the toner is applied to the primary transfer bias rollers 9Y, 9M, 9C, and 9K. The intermediate transfer belt 8 travels in the direction of the arrow, and sequentially passes through the primary transfer nips of the primary transfer bias rollers 9Y, 9M, 9C, and 9K. In this way, the toner images of the respective colors on the photosensitive drums 1Y, 1M, 1C, and 1K are primarily transferred onto the intermediate transfer belt 8 in an overlapping manner. ("Primary transfer process"). In this way, a color image is formed on the intermediate transfer belt 8.

  Thereafter, the intermediate transfer belt 8 on which the toner images of the respective colors are transferred in a superimposed manner reaches a position facing the secondary transfer roller 19. At this position, the secondary transfer backup roller 12 sandwiches the intermediate transfer belt 8 with the secondary transfer roller 19 to form a secondary transfer nip. The four-color toner images formed on the intermediate transfer belt 8 are transferred onto a transfer material (recording material) P such as transfer paper conveyed to the position of the secondary transfer nip (“secondary” Transfer process "). At this time, the untransferred toner that has not been transferred to the transfer material P remains on the intermediate transfer belt 8. Thereafter, the intermediate transfer belt 8 reaches the position of the belt cleaning device 10. At this position, the untransferred toner on the intermediate transfer belt 8 is collected. Thus, a series of transfer processes performed on the intermediate transfer belt 8 is completed.

  Here, the transfer material P conveyed to the position of the secondary transfer nip is fed from the paper feed unit 26 disposed below the printer 100 apparatus main body via the paper feed roller 27, the registration roller pair 28, and the like. It has been transported. Specifically, a plurality of transfer materials P such as transfer paper are stored in the paper supply unit 26 in a stacked manner. When the paper feed roller 27 is rotated in the counterclockwise direction in FIG. 1, the uppermost transfer material P is fed between the rollers of the registration roller pair 28.

  The transfer material P conveyed to the registration roller pair 28 is temporarily stopped at the position of the roller nip of the registration roller pair 28 that has stopped rotating. Then, the registration roller pair 28 is rotationally driven in time with the color image on the intermediate transfer belt 8, and the transfer material P is conveyed toward the secondary transfer nip. In this way, a desired color image is transferred onto the transfer material P.

  Thereafter, the transfer material P on which the color image has been transferred at the position of the secondary transfer nip is conveyed to the position of the fixing unit 20. At this position, the color image transferred to the surface is fixed on the transfer material P by heat and pressure generated by the fixing roller and the pressure roller. Thereafter, the transfer material P is discharged out of the apparatus through the rollers of the discharge roller pair 29. The transfer material P discharged from the apparatus by the discharge roller pair 29 is sequentially stacked on the stack unit 30 as an output image. In this way, a series of image forming processes in the printer is completed.

  Next, an inlet seal provided at the upstream of the developing device 5 in the image forming unit 6 and the developing region of the developing device 5 and the photosensitive drum 1 in the rotation direction of the photosensitive drum 1, which is a characteristic part of the present embodiment. The configuration and operation of the members will be described in more detail. As shown in FIG. 2, the developing device 5 includes a developing roller 51 that is a developer carrying member facing the photosensitive drum 1, a doctor blade 52 facing the developing roller 51, and two in the developer containing portions 53 and 54. A conveyance screw 55 that is a conveyance member is provided. Further, a density detection sensor 56 that detects the toner density in the developer, an inlet seal 57 that contacts the photosensitive drum, and the like are also provided.

  The developing roller 51 includes a magnet fixed inside, a sleeve rotating around the magnet, and the like. In the developer accommodating portions 53 and 54, a two-component developer G containing a carrier and toner is accommodated. The developer accommodating portion 54 communicates with the toner transport pipe 43 that is a toner replenishment path through an opening formed thereabove.

  The developing device 5 operates as follows. The sleeve of the developing roller 51 rotates counterclockwise, which is the direction of the arrow in FIG. The developer G carried on the developing roller 51 by the magnetic field formed by the magnet moves on the developing roller 51 as the sleeve rotates. Here, the developer G in the developing device 5 is adjusted so that the toner concentration (toner concentration) in the developer is detected by the toner concentration sensor 56 and the toner concentration falls within a predetermined range. Specifically, the toner stored in the toner cartridge 32 is replenished into the developer storage portion 54 via the toner transport pipe 43 according to the consumption of toner in the developing device 5.

  Thereafter, the toner replenished in the developer accommodating portion 54 is mixed and stirred together with the developer G by the two conveying screws 55, and the two developer accommodating portions 53, 54 are perpendicular to the paper surface in FIG. The direction moves and circulates. The toner in the developer G is attracted to the carrier by frictional charging with the carrier, and is carried on the developing roller 51 together with the carrier by the magnetic force formed on the developing roller 51.

  The developer G carried on the developing roller 51 is conveyed in the direction of the arrow in FIG. 2 and reaches the position of the doctor blade 52. The developer G on the developing roller 51 is conveyed to a developing area that is a position facing the photosensitive drum 1 after the developer amount is made appropriate at this position. The toner is attracted to the latent image formed on the photosensitive drum 1 by the electric field formed in the development area. Thereafter, the developer G remaining on the developing roller 51 reaches the upper portion of the developer containing portion 53 as the sleeve rotates, and is detached from the developing roller 51 at this position.

  In the developing area, the developer G is rubbed against the photosensitive drum 1, and at this time, toner separated from the carrier is attracted to the photosensitive drum 1 and scattered to the space. The toner scattered downward from the developing area, that is, from the developing area to the upstream side in the rotation direction of the photosensitive drum 1 is supplied to the apparatus by a flexible inlet seal 57 that is in contact with the photosensitive drum 1 provided to protrude from the developing device 5. Prevents splashing outside. This is to prevent the scattered toner from scattering to the upstream side in the rotation direction of the photosensitive drum by closing the space connecting from the developing region to the upstream side in the rotation direction of the photosensitive drum by the inlet seal 57. Further, the toner scattered upward is sucked into the developing device 5 by a suction air flow generated by sliding the developer accommodating portion 53 and the developer G on the developing roller 51.

  However, the toner scattered from within the developing area accumulates on the entrance seal 57, and the toner accumulated on the entrance seal 57 increases and accumulates. The toner deposited on the inlet seal 57 is attracted (developed) to the photoconductor 1 by the potential of the photoconductor drum 1 and causes an abnormal image such as a background stain or a toner drop image. There is. In recent years, toner scattering has been increasing due to the reduction in toner particle size due to demands for higher speed and higher image quality of image forming apparatuses and longer life due to the demand for high durability. The problem of abnormal images due to toner accumulation has become apparent.

  Therefore, in the present embodiment, the developing device 5 is configured as follows. The inlet seal 57 provided in the developing device 5 is supported by the case of the developing device 5 in a movable state, and moves to both the photosensitive drum 1 as a latent image carrier and the developing roller 51 as a developer carrier. Thus, it is configured to be able to contact alternatively. In other words, the inlet seal 57 is provided so as to be movable, so that it can move and selectively contact either the photosensitive drum 1 or the developing roller 51. With this configuration, it is possible to select either the photosensitive drum 1 or the developing roller 51 and move the inlet seal 57 in contact with the inlet seal 57 in conjunction with the operation of the developing device 5. become.

  With this configuration, the scattered toner accumulated on the entrance seal 57 in a state where the entrance seal 57 is in contact with the photosensitive drum 1 is brought into contact with the developing roller 51 and the inside of the developing device 5. Can be recovered. The scattered toner collected on the inlet seal 57 is collected in the developing device 5 by bringing the inlet seal 57 into contact with the developing roller 51 at a predetermined timing such as when image formation is completed. It is possible to prevent toner accumulation on the surface. Therefore, it is possible to provide the developing device 5 that can prevent toner accumulation on the inlet seal 57 and prevent the occurrence of abnormal images over a long period of time.

  Further, in conjunction with the operation of the developing device 5, as a specific configuration for bringing the inlet seal 57 into contact with either the photosensitive drum 1 or the developing roller 51, a dedicated solenoid or the like for rotating the inlet seal 57 is used. It is also possible to provide and control. However, in the configuration in which a dedicated solenoid or the like is provided, cost is increased or the developing device 5 is increased in size. Therefore, in the present embodiment, the configuration is made to be interlocked with the reverse rotation driving of the developing roller 51 of the developing device 5. .

  Next, an example of a specific configuration in which the inlet seal 57 of this embodiment is interlocked with the reverse rotation driving of the developing roller 51 will be described with reference to FIGS. As shown in FIG. 3, the inlet seal 57 is held by a holder 58 that is a holder for the inlet seal formed in a substantially square shape. The holder 58 is supported by the developing device 5 so as to be rotatable about a rotation center B in the vicinity of the folding point of the dogleg. In any of the rotated states, the vicinity of the folding point of the dogleg is at the doctor blade 52. It is comprised so that the state contact | abutted to the surface may be hold | maintained.

  An inlet seal 57 is bonded to the downstream side in the rotation direction of the photosensitive drum 1 that is one end side of the holder 58 and protrudes in the entire length direction of the developing roller. When the holder 58 rotates about the rotation center B, the entrance seal 57 comes into contact with either the photosensitive drum 1 or the developing roller 51. Further, the end on the downstream side in the rotational direction of the photosensitive drum 1, which is the other end of the holder 58, has a spring (not fixed) in the direction of arrow C shown in FIG. Etc.). At the end of the photosensitive drum 1 at the end, a cam 60 is connected to a developing drive gear 59 provided at one end in the longitudinal direction of the developing roller 51 via a one-way clutch (not shown). It is comprised so that it may contact | abut.

  Here, the cam 60 has a substantially gourd shape with the rotation axis as the target axis. Then, with the longitudinal surface of the cam 60 in contact with the end of the holder 58, the opposite side of the end of the holder 58 is pressed against and contacted with the doctor blade 52, and the inlet seal 57 contacts the photoreceptor drum 1. Contact with a predetermined amount of contact. Further, in a state where the short side surface of the cam 60 is in contact with the end portion of the holder 58, the opposite side of the end portion of the holder 58 is separated from the doctor blade 52, and the inlet seal 57 is attached to the developing roller 51 in a predetermined manner. Contact at the end. Further, the rotation of the cam 60 is performed by transmitting only the reverse rotation in 90 ° units of the developing drive gear 59 rotated in the reverse direction to the time of image formation via the one-way clutch.

  Then, during normal image formation, as shown in FIG. 3, the longitudinal surface of the cam 60 abuts against the end of the holder 58 against the biasing force of a spring or the like in the direction of arrow C, and the inlet seal 57 is The photosensitive drum 1 is in contact with a predetermined amount of contact. As described above, when the image forming operation is performed in a state in which the inlet seal 57 is in contact with the photosensitive drum 1, scattering of toner from the developing region to the upstream side in the rotational direction of the photosensitive drum 1 can be prevented. However, as described above, when a large amount of the scattered toner T scattered in the space A on the upstream side in the rotation direction of the photosensitive drum 1 in the developing region accumulates, the scattered toner T moves to the photosensitive drum 1 due to the potential of the photosensitive drum 1. Causes abnormal images.

  In the present embodiment, at a predetermined timing such as at the end of image formation, a reverse rotation operation is performed in which the developing drive gear 59 is reversely rotated by 90 °. Then, the cam 60 is rotated by the connection of the one-way clutch, and the holder 58 is moved in the direction of arrow D in FIG. 4 so as to contact the surface in the short direction of the cam 60 with the rotation center B as a fulcrum by the spring force. To do. At this time, the tip of the inlet seal 57 moves from the photosensitive drum 1 to the developing roller 51 as shown in FIG. During this movement, the scattered toner T that has been received by the inlet seal 57 so far is adhered to the developer G on the developing roller 51, whereby the scattered toner T that has accumulated on the inlet seal 57 is removed. Thereafter, the state is further reversed by 90 ° from this state before the normal image formation, and the entrance seal 57 is brought into contact with the photosensitive drum 1 to obtain the normal image formation state as shown in FIG. Prepare for the image forming operation. Further, the rotational driving force of the developing drive gear 59 during normal image formation is not transmitted to the cam 60 by the one-way clutch, so that the postures of the cam 60, the holder 58, and the inlet seal 57 are maintained.

  In this embodiment, the gear that connects the rotation shaft of the cam 60 is the developing drive gear 59, but is not limited to the driving gear, and the rotational driving force is transmitted from the driving gear to the gear of the developing roller 51. An idler gear may be used. Further, the shapes of the holder 58 and the cam 60 are not limited to the above-described configuration, and the entrance seal 57 contacts the photosensitive drum 1 during image formation, and the entrance seal 57 rotates when the developing roller 51 reverses. Any structure that contacts the developing roller 51 may be used.

  Further, the developing device 5 of the present embodiment is configured to be detachable from the printer main body as a process cartridge including at least one of the photosensitive drum 1, the charging device 4, and the photosensitive member cleaning device 2, and the developing device 5. Can be provided as.

As described above, the developing device 5 of the present embodiment can provide the following operations and effects. Since the entrance seal 57 can move and selectively come into contact with either the photosensitive drum 1 or the developing roller 51, either the photosensitive drum 1 or the developing roller 51 is connected in conjunction with the operation of the developing device 5. It is possible to select and move the inlet seal 57 into contact. The scattered toner accumulated on the entrance seal 57 in a state where the entrance seal 57 is in contact with the photosensitive drum 1 can be collected in the developing device 5 by bringing the entrance seal 57 into contact with the developing roller 51. It is. Accordingly, the scattered toner T collected on the inlet seal 57 is collected in the developing device 5 by bringing the inlet seal 57 into contact with the developing roller 51 at a predetermined timing such as when image formation is completed, so that the inlet seal 57 is recovered. Accumulation of scattered toner T can be prevented. Therefore, it is possible to provide the developing device 5 that can prevent the scattered toner T from accumulating on the inlet seal 57 and prevent the occurrence of abnormal images over a long period of time.
Also, the contact of the developing roller 51 of the incoming mouth seal 57, since the interlocked with the reverse rotation of the developing roller 51 for a predetermined time at the end of image formation or the like, without providing a dedicated solenoid or the like, certainly It can be brought into contact with the developing roller 51. As a result, the developing device 5 has a low-cost configuration and does not increase the size of the developing device 5, prevents the scattered toner T from accumulating on the inlet seal 57, and prevents the occurrence of abnormal images over a long period of time. Can also be provided.
Further, since the process cartridge according to the present embodiment includes at least one of the photosensitive drum 1, the charging device 4, and the photosensitive member cleaning device 2, and the developing device 5 described above, the same operation and function as the developing device 5 described above are provided. There is an effect.
In addition, since the image forming apparatus of the present embodiment includes the developing device 5 described above, the same operations and effects as those of the developing device 5 described above can be achieved.
In addition, since the image forming apparatus of the present embodiment includes the process cartridge described above, the same operations and effects as those of the process cartridge described above can be achieved.

DESCRIPTION OF SYMBOLS 1 Photoconductor drum 2 Photoconductor cleaning apparatus 4 Charging apparatus 5 Developing apparatus 6 Image forming part 7 Exposure part 8 Intermediate transfer belt 15 Intermediate transfer unit 20 Fixing part 26 Paper feed part 30 Stack part 51 Developing roller 52 Doctor blade 57 Entrance seal 58 Holder 59 Development drive gear 60 Cam 100 Printer

Japanese Patent No. 3492858 JP 10-307474 A

Claims (4)

A developer carrying member, and a flexible seal member that suppresses scattered toner from a developing region where the latent image carrying member and the developer carrying member face each other, and is formed on the latent image carrying member. In the developing device for developing the latent image with a two-component developer composed of toner and carrier,
The seal member is supported in a movable state by the case of the developing device,
Both the said latent image bearing member and said developer carrying member, Ri alternatively contactable der moved,
At the time the image forming contact to said latent image bearing member, in conjunction with reverse rotation of the developer carrier, a developing device according to claim contact to Rukoto to the developer carrier. In a process cartridge comprising at least one of a latent image carrier, a charging device, a cleaning device, and a developing device,
A process cartridge comprising the developing device according to claim 1 as the developing device. An image forming apparatus comprising the developing device according to claim 1 as a developing device. An image forming apparatus comprising the process cartridge according to claim 2 as a process cartridge of an image forming unit.

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