JP5874243B2 - Developing device, process unit, and image forming apparatus - Google Patents

Description

  The present invention relates to a developing device, a process unit, and an image forming apparatus.

  Generally, in an electrophotographic image forming apparatus or the like, either a one-component system composed only of toner or a two-component system composed of toner and carrier is used as a developer. Since the one-component developer has advantages such that the configuration of the developing device can be simplified and maintenance is easy, various developing devices for the one-component developer have been proposed.

  As shown in FIG. 6, a conventional developing device 100 that uses a one-component developer is disposed in a developing roller 500 that supplies toner to a photosensitive member 300 and a toner container 600, and a supply that supplies toner to the developing roller 500. The roller 700 and the doctor blade 800 that contacts the surface of the developing roller to frictionally charge the toner and regulate the layer thickness are provided as a basic configuration. In the developing device of FIG. 6, the toner is supplied to and removed from the developing roller 500 by a common roller 700. However, as shown in FIG. 7, the toner is supplied and removed from different rollers (a supply roller 710 and a removal roller 720). ).

  As a developing device for a one-component developer, for example, JP 2006-178034 A (Patent Document 1), JP 2003-021695 A (Patent Document 2), and JP 2001-194904 A (Patent Document 1). Those described in the literature 3) are known.

  By the way, in the developing device, the friction generated in the contact portion between the developing roller 500 and the doctor blade 800, the contact portion between the developing roller 500 and the photosensitive member 300, and the contact portion between the developing roller 500 and the supply roller 700, and the toner storage portion 600. The toner is subjected to external force and stress due to friction with other members accompanying the stirring and conveyance of the toner inside and in a toner conveyance path (not shown) reaching here. As a result, the toner deteriorates, and fine powder smaller than the toner particles is generated due to liberation of external additives, cracking of the toner, and the like. These fine powders (hereinafter referred to as “foreign substances”) that are not the original toner are weakly charged or reversely charged when the toner is charged, and may move differently from normal toner in an electric field. In addition, because of the small size, the physical adsorption force is large and large aggregates are easily formed, and therefore, they tend to adhere to various members (particularly doctor blades) and filming. Therefore, there is a possibility that the operation stability of the image forming apparatus is impaired.

  The developing device described in Patent Document 1 uses toner on the developing roller to prevent development streaks and development blades from fusing when using a developer having a small particle diameter or a developer in which WAX resin is dispersed. A configuration has been proposed in which the developing roller is refreshed by applying an AC voltage to the stripping buffer roller and controlling the period of the AC voltage. However, in such a developing device, even if the foreign matter is peeled off from the developing roller by the buffer roller, the foreign matter is returned to the developing roller again and supplied to the contact portion between the doctor blade and the developing roller. For this reason, it is impossible to prevent foreign matter from sticking to the developing blade and filming.

  Further, the developing device described in Patent Document 2 attaches the external additive to the non-image forming area of the photosensitive drum in order to prevent the external additive from accumulating on the toner supply roller, and at the photosensitive drum cleaning position. It is configured to collect. However, since the collection position of the external additive in the two-component developer is on the photosensitive drum, there is a possibility that foreign matter may accumulate on various parts (particularly the regulation blade) from the toner supply position to the collection position.

  Further, the developing device described in Patent Document 3 relates to recovery of defectively charged toner in a one-component developer. A defectively charged toner removing member is provided on the upper side of the developing roller, and a removed toner collecting member is arranged so that one end of the toner comes into contact with the defectively charged toner removing member. However, since the defectively charged toner removing member is provided on the downstream side of the thin layer blade as the developer regulating member, foreign matter in the toner may be deposited on the thin layer blade.

  As described above, in any of the patent documents, it is insufficient to prevent the foreign matters contained in the toner from accumulating on the doctor blade.

  SUMMARY OF THE INVENTION In view of such circumstances, it is an object of the present invention to provide a developing device, a process unit, and an image forming apparatus that prevent foreign matters from accumulating on various members and perform good and stable image formation over the long term. .

In order to achieve the above object, the present invention provides a rotatable developer carrier that carries a one-component developer on its surface and supplies the developer to a latent image carrier that has formed an electrostatic latent image, agent regulating member for regulating the layer thickness with in contact with the surface of the carrier to frictionally charge the developer, a developer accommodating portion for accommodating the developer, disposed in said developer accommodating portion, said developer container the developer contained a developing apparatus having a supply member for supplying the developer bearing member is disposed between the supply member and the developer carrying member, which is supplied from the supply member the developer has a collecting member for supplying the contact portion between the regulating member and said developer carrying member, the the collecting member, and configured to collect foreign matter in the developer by its smooth surface It is characterized by this.

  According to the present invention, by newly arranging a collecting member between the supply member and the developer carrier, it is possible to separate minute foreign matters contained in the developer without using a complicated mechanism. In addition, accumulation of minute foreign matters on the surface of each member can be prevented. In particular, since the minute foreign matter is separated immediately before the contact portion between the regulating member and the developer carrier, the developer from which the minute foreign matter has been removed can be supplied to the contact portion, Adherence of foreign matters can be prevented.

1 is an external perspective view of an image forming apparatus to which an embodiment of the present invention is applied. It is a schematic sectional drawing which shows an example of the internal structure of the said image forming apparatus. It is a schematic sectional drawing of the process unit mounted in the said image forming apparatus. It is a schematic sectional drawing which shows the other example of the said process unit. It is a schematic sectional drawing which shows the other example of the said process unit. It is a schematic sectional drawing of the conventional image development apparatus. It is a schematic sectional drawing of the other conventional image development apparatus.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. Throughout the embodiments and modifications, components such as members and components having the same function or shape are denoted by the same reference numerals as much as possible, and once described, the description is omitted.

  First, an overall configuration and operation of an image forming apparatus to which an embodiment of the present invention is applied will be described with reference to FIGS. FIG. 1 is an external perspective view of an image forming apparatus to which an embodiment of the present invention is applied, and FIG. 2 is a schematic longitudinal sectional view showing an example of an internal configuration of the image forming apparatus. The image forming apparatus shown in both figures is a tandem type color image forming apparatus.

  The image forming apparatus shown in FIGS. 1 and 2 is disposed almost at the center of the apparatus main body 1, and is disposed below the image forming part 2 and an image forming part 2 that forms an image on a sheet SH as a recording medium. A paper feed unit 20 that feeds the paper SH to the image forming unit 2, a paper discharge unit 25 that discharges the paper SH image-formed by the image forming unit 2, and an upper part of the image forming unit 2. And a stacking unit 40 on which sheets SH discharged from the unit 25 are stacked. Paper SH includes not only plain paper (including thick paper, postcards, envelopes, plain paper, thin paper, etc.) such as transfer paper and recording paper, but also coated paper (including coated paper, art paper, etc.), OHP sheet or An OHP film or tracing paper is also included.

  As shown in FIG. 2, the image forming unit 2 includes a plurality of drum-shaped photoconductors 3a, 3b, 3c, and 3d configured as latent image carriers, and each of the photoconductors 3a to 3d includes: Toner images of different colors are formed. In the illustrated example, a yellow toner image, a cyan toner image, a magenta toner image, and a black toner image are formed on the surfaces of the photoreceptors 3a to 3d, respectively. The photoconductors 3a to 3d are arranged in parallel with each other at a predetermined interval, and an intermediate transfer belt 4 configured as an intermediate transfer body is arranged facing the lower portions of the photoconductors 3a to 3d. The intermediate transfer belt 4 is an endless belt that is wound around a plurality of support rollers 5 and 6 and driven in the direction of an arrow (counterclockwise in FIG. 2). A drum can also be used as the intermediate transfer member.

  Since the configuration around each of the photoconductors 3a to 3d is common, the configuration around the photoconductor 3a on which the yellow toner image arranged on the rightmost side in FIG. 2 is formed will be described as a representative. Around the photosensitive member 3a, a charging roller 7 as a charging means for uniformly charging the surface of the photosensitive member 3a, and a laser beam is applied to the surface of the photosensitive member 3a based on the image information to electrostatic latent. An optical scanning device (LSU) 8 that forms an image, a developing device 9 that visualizes an electrostatic latent image formed on the surface of the photoconductor 3 a, and the photoconductor 3 a via the intermediate transfer belt 4. A transfer device 10 and a cleaning blade 11 as a cleaning unit for removing toner remaining on the surface of the photoreceptor 3a after being transferred to the intermediate transfer belt 4 are disposed. Above the developing device 9, a toner container and a replenishing mechanism are arranged. The replenishing mechanism is driven according to toner consumption in the developing device 9, and toner is supplied from the toner container to the developing device 9.

  When image formation is started in such an image forming apparatus, the photoreceptor 3a is rotated in the clockwise direction in FIG. 2, and the surface of the photoreceptor 3a is uniformly charged to a predetermined polarity by the charging roller 7. Next, the charged surface is irradiated with laser light based on image information from the optical scanning device 8, thereby forming an electrostatic latent image on the photoreceptor 3 a. The electrostatic latent image formed on the surface of the photoreceptor 3 a is visualized as a yellow toner image by the toner supplied from the developing roller 45 of the developing device 9, and the yellow toner image is visualized by the transfer device 10 as the intermediate transfer belt 4. Transcribed above.

  At the time of full color image formation, the above-described image forming operation is performed in the same manner on all the remaining photoconductors 3b to 3d, whereby yellow toner images, cyan toner images, and magenta toner images respectively formed on the respective photoconductors 3a to 3d. Then, the black toner image is sequentially superimposed and transferred onto the intermediate transfer belt 4. In the image forming apparatus, a secondary transfer roller 12 is disposed so as to face the support roller 6 with the intermediate transfer belt 4 interposed therebetween.

  On the other hand, a paper feed unit 20 disposed below the image forming unit 2 includes a paper feed tray 21 on which the paper SH is stacked, a paper feed roller 22 that sends out the paper SH stacked on the paper feed tray 21, A friction pad 23 and the like for separating the fed paper into one sheet are provided.

  The paper SH fed from the paper supply unit 20 is sent out toward the registration roller 13 and is once abutted against the registration roller 13 whose tip is stopped. This corrects and aligns the oblique deviation of the leading end of the sheet SH. Thereafter, the registration roller 13 resumes rotation at a timing such that the color toner image formed on the intermediate transfer belt 4 matches the leading edge of the sheet SH at the secondary transfer portion provided with the secondary transfer roller 12. The sheet SH is sent out to a secondary transfer portion (transfer portion) provided with the secondary transfer roller 12.

  The sheet SH on which the unfixed color toner image is transferred in the secondary transfer unit is sent to the fixing unit 14 which is a fixing device, and after the unfixed color toner image is fixed by heating and pressing by the fixing unit 14. Then, the paper is discharged with a pair of paper discharge rollers 25a and 25b of the paper discharge unit 25 onto the stacking unit 40 provided on the upper surface of the apparatus body 1 with the image surface facing downward (face down). The fixing unit 14 includes, for example, a fixing roller 14a, a fixing belt 14c wound around the fixing roller 14a, and a pressure roller 14b that is in pressure contact with the fixing roller 14a via the fixing belt 14c. The fixing unit 14 is not limited to the configuration described above, and a roller type with a built-in heater, a heating type using IH, or the like can be appropriately employed. The transfer residual toner and the like attached to the surface of the intermediate transfer belt 4 after the color toner image transfer is removed by the belt cleaning device 15.

  An upper cover 18 as an upper cover member that covers the image forming unit 2 is provided on the upper portion of the apparatus main body 1. In the present embodiment, the upper surface portion of the upper cover 18 is used as a paper discharge tray (sheet stacking surface) 41 of the stacking unit 40.

  Further, as shown in FIG. 2, the upper cover 18 supports the optical scanning device 8 which is a part of the image forming unit 2 at the lower portion thereof, and is located above a hinge 17 provided on the rear end side of the device. It is configured to be openable. The upper cover 18 is locked to the apparatus main body 1 by a lock lever 60 serving as a locking means described later, and when the lock is released, the upper cover 18 can be opened and closed. Although not shown, when the upper cover 18 is opened counterclockwise, the lower optical scanning device 8 moves together with the upper cover 18. This makes it possible to access the image forming unit 2 for maintenance and the like, and the process unit 30 in which the photoconductors 3a to 3d, the charging roller 7, the developing device 9, and the cleaning blade 11 are integrated can be attached and detached. It becomes.

  In the image forming apparatus shown in FIGS. 1 and 2, the operation unit 61 that releases the lock of the lock lever 60 and allows the upper cover 18 to swing and be opened is provided on the paper discharge tray 41 and the stocked paper SH. It is provided at a position hidden by The lock lever 60 is integrally provided with an operation portion 61 operated by a user on one end side and a lock claw 62 engaged with a protrusion 64 fixed to the apparatus main body 1 on the other end side. The lock lever 60 is supported so as to be rotatable about a pin 63 fixed to the upper cover 18. The lock lever 60 is applied with a biasing force in a direction in which the lock claw 62 always engages the protrusion 64 by a torsion coil spring (not shown) mounted around the pin 63. The operation portion 61 of the lock lever 60 is formed of a plate material having a surface that is on the same plane as the paper discharge tray 41, so that the operation portion 61 can be put on the paper discharge tray 41. For this purpose, a fan-shaped recess 44 is formed as shown in FIG.

  When opening the upper cover 18, a hand is inserted from the recess 44, and the operating portion 61 of the lock lever 60 is lifted up against the urging force of a torsion coil spring (not shown), so that the lock lever 60 is centered on the pin 63. The lock claw 62 is disengaged from the protrusion 64 by rotating clockwise. Then, the upper cover 18 is swung around the hinge 17 by lifting the operation unit 61 as it is.

[First Embodiment]
FIG. 3 is a schematic cross-sectional view of a process unit 30 having the photoreceptors 3a to 3d and the developing device 9. The image forming apparatus is equipped with four process units 30 each including any one of the four photoconductors 3a to 3d. Since the configuration of each process unit 30 is basically common, In the description, the configuration of one of the process units 30 will be described (the corresponding photosensitive drum is denoted by “3”), and description of the other process units 30 will be omitted.

  As shown in FIG. 3, the process unit 30 includes a photoconductor housing 31 to which the photoconductor 3 is mounted, and a developing housing 32 to which various components constituting the developing device 9 are mounted. The photoreceptor housing 31 and the development housing 32 are configured to be assembled and separated. Between the photosensitive member housing 31 and the developing housing 32 assembled to each other, a laser beam path space 33 through which the laser beam L irradiated to the photosensitive member 3 from the optical scanning device 8 shown in FIG.

  In addition to the photosensitive member 3, the photosensitive member housing 31 includes a charging roller 7, a charging roller cleaning member 26 for cleaning the surface of the charging roller 7, a cleaning blade 11 as a cleaning unit for cleaning the surface of the latent image carrier, and cleaning. A toner recovery member 27 (first developer recovery member) that transports the transfer residual toner removed from the surface of the photoreceptor 3 by the blade 11 to a waste toner recovery unit (not shown) is mounted.

  The charging roller 7 is configured by covering a conductive cored bar with a conductive elastic layer (conductive rubber or the like). The charging roller 7 is connected to a power source (not shown), and one or both of a predetermined DC voltage and an AC voltage are applied. The charging roller 7 removes the charge / potential difference remaining on the surface of the photoconductor 3 after the transfer, and uniformly charges the surface of the photoconductor 3 to a predetermined polarity.

  The cleaning blade 11 is formed of a plate-like rubber or the like, and is in contact with the photoconductor 3 in a counter state. By this contact, the toner remaining on the photosensitive member 3 and the additive (talc, kaolin, calcium carbonate, etc.) of the paper SH adhering as dirt are removed and conveyed to the waste toner collecting unit by the toner collecting member 27.

  The developing housing 32 is provided with a toner containing portion 35 (developer containing portion) for containing toner replenished from a toner cartridge (not shown). The toner accumulated in the toner storage unit 35 (shown as dots in FIG. 3) passes through the supply roller 37 (supply member), the collection roller 36 (collection member), and the development roller 45 (developer carrier). Supplied to the photoreceptor 3. As the toner, a one-component system containing no carrier is used. Either magnetic toner or non-magnetic toner can be used. In this embodiment, for example, a nonmagnetic toner having negative chargeability can be used.

  The supply roller 37 is disposed in the vicinity of the toner outlet of the toner container 35 and is driven to rotate in the direction of arrow C in the drawing. The supply roller 37 can be formed of, for example, a conductive foamed urethane material.

  The collecting roller 36 is disposed between the supply roller 37 and the developing roller 45 and is in contact with both the supply roller 37 and the developing roller 45. The collection roller 36 is made of a metal such as stainless steel, and the outer peripheral surface thereof is smoothed by polishing or the like. The collection roller 36 is rotationally driven in the forward direction (the direction of arrow D in the figure) with respect to the supply roller 37. Although not shown, it is desirable to connect an AC power source to the collection roller 36.

  The developing roller 45 is configured by covering a conductive cored bar with a conductive elastic body, for example, a urethane foam material. The developing roller 45 is in pressure contact with each of the collecting roller 36 and the photosensitive member 3, and nips N and P are formed between the developing roller 45 and each member. The developing roller 45 is connected to a bias power source such as a negative polarity DC power source, and a developing bias having a predetermined potential is applied thereto. The developing roller 45 of this embodiment is rotationally driven in the counter direction (the direction of arrow B in the figure) with respect to the collecting roller 36.

  A cleaning member 38 is in contact with the outer peripheral surface of the collecting roller 36. The cleaning member 38 is fixed to the developing housing 32 and comes into contact with the collecting roller 36 on the downstream side in the rotation direction of the collecting roller 36 with respect to the nip N between the collecting roller 36 and the developing roller 45. The configuration of the cleaning member 38 is arbitrary, and can be formed of an elastic body such as rubber. Foreign matter adhering to the collecting roller 36 is removed from the roller surface by the cleaning member 38, and the removed foreign matter is transferred to a collecting unit (not shown) by a foreign matter collecting screw 39 (foreign matter collecting member).

  Further, the developing housing 32 includes a doctor blade 46 (regulating member) for regulating the layer thickness of the toner carried by the developing roller 45, a removing roller 47 (removing member) for removing residual toner on the surface of the developing roller 45, and a doctor blade. A second toner collecting member 48 (second developer collecting member) for collecting the toner scraped by the toner 46, and a third toner collecting member 49 (third developing member) for collecting the toner removed by the removing roller 47. The agent recovery member is mounted.

  The doctor blade 46 is made of a conductive member such as stainless steel, and contacts the developing roller 45 downstream of the nip N between the collecting roller 36 and the developing roller 45 in the rotation direction of the developing roller 45. By this contact, excess toner on the surface of the developing roller 45 is removed, and a charge due to friction is given to the toner passing through the contact portion.

  The excess toner removed by the doctor blade 46 is transferred to the toner storage unit 35 by the second toner recovery member 48. The second toner collecting member 48 is disposed in a compartment 352 that is partitioned from the toner containing portion 35 by a partition wall 32 a provided in the developing housing 32.

  The removal roller 47 is made of, for example, urethane foam, and is rotationally driven in a counter rotation direction (the direction of arrow E in the drawing) with respect to the developing roller 45. The removing roller 47 is disposed downstream of the nip P between the developing roller 45 and the photosensitive member 3 in the rotation direction of the developing roller 45, and removes excess toner on the surface of the developing roller 45 that has not been supplied to the photosensitive member 3. . The removed toner is transferred to the toner container 35 by the third toner collecting member 49.

  The partition wall 32 a of the developing housing 32 extends to the vicinity of the outer peripheral surface of the collecting roller 36. A seal 353 is provided at the tip of the partition wall 32a, and the seal 353 seals the gap around the collection roller 36, specifically, the gap between the tip of the partition wall 32a and the outer peripheral surface of the collection roller 36. Toner leakage is prevented. In addition to using a contact-type seal member, a non-contact seal can also be used as the seal.

  With this configuration, the toner container 35 partitioned by the partition wall 32a, the collection roller 36, and the cleaning member 38 is substantially sealed. Further, the gap S between the outer peripheral surface of the supply roller 37 and the developing housing 32 is made as small as possible so that unnecessary toner does not enter the space downstream of the supply roller 37. In this embodiment, the case where the gap S is narrowed by bringing the partition wall 32a and the cleaning member 38 close to the outer peripheral surface of the supply roller 37 is illustrated. With the above configuration, most of the toner in the toner container 35 is supplied to the developing roller 45 through the contact point between the supply roller 37 and the collecting roller 36. The gap S may be sealed with a sealing member.

  Note that, on the downstream side in the rotation direction of the collecting roller 36 from the nip N between the collecting roller 36 and the developing roller 45, the inner surface of the developing housing 32 is close to the collecting roller 36 and forms a gap. A space defined by the cleaning member 38, the collecting roller 36, and the developing housing 32 is sealed by sealing this gap (a peripheral gap around the collecting roller 36) with, for example, a seal member 354 provided on the inner surface of the developing housing 32. Can be substantially sealed. This sealing can also be performed by a non-contact seal.

  With the above configuration, the toner stored in the toner storage unit 35 is transferred from the supply roller 37 toward the nip N between the developing roller 45 and the collecting roller 36. A certain amount of charge is imparted to the toner by the friction caused by the counter rotation at the nip N, and the charged toner adheres to the surface of the developing roller 45. The toner on the developing roller 45 is charged to a predetermined potential by being given a larger charge by friction with the doctor blade 46. Thereafter, the toner reaching the nip P with the photosensitive member 3 is transferred to the surface of the photosensitive member 3 by a transfer bias, and an electrostatic image is visualized.

  Here, the foreign matter contained in the toner is a fine powder such as an external additive or a cracked toner and is finer than the toner particles, and therefore has a higher physical adsorption force to other members than the toner. In the present invention, as described above, the collecting roller 36 having a newly smoothed surface is disposed between the supply roller 37 and the developing roller 45. On the smoothed surface of the collecting roller 36, normal toner particles are easily separated from the surface, but foreign matters having a small particle diameter are easily adsorbed on the surface. Therefore, the regular toner on the collecting roller 36 is transferred to the developing roller 45, but the foreign matter contained in the toner passes through the nip N while adhering to the surface of the collecting roller 36. The foreign matter on the surface of the collecting roller 36 that has passed through the nip N is scraped off by the cleaning member 38, and further conveyed to a waste toner collecting portion (not shown) by the foreign matter collecting screw 39 and discarded.

  In this way, by newly disposing the collecting roller 36 between the supply roller 37 and the developing roller 45, foreign matters contained in the toner can be separated without using a complicated mechanism. Further, since the foreign matter is separated immediately before the contact portion between the doctor blade 46 and the developing roller 45, the toner from which the foreign matter has been removed can be supplied to the contact portion. It is possible to prevent foreign matter from adhering to the surface of the doctor blade 46 that is likely to occur. In addition, the space where the foreign material is removed by the cleaning member 38 is a sealed space that is isolated from the toner container 35 and the toner moving path as described above, and therefore the collected foreign material is not mixed into the toner again. Absent. Accordingly, it is possible to prevent sticking of foreign matter and filming at various locations inside the image forming apparatus over a long period of time.

  Further, if an AC voltage is applied to the collecting roller 36, the movement of the toner on the surface of the collecting roller 36 is activated. For this reason, the separation of the foreign matter and the toner is promoted, and the separation effect of the foreign matter is enhanced.

[Second Embodiment]
Next, another embodiment of the process unit 30 according to the present invention will be described. FIG. 4 is a schematic sectional view showing another example of the process unit 30. Note that the present embodiment is intended for a monochrome image forming apparatus using a single color toner.

  The process unit 30 of this embodiment has substantially the same configuration as that of the first embodiment, but the transfer residual toner removed from the surface of the photoreceptor 3 by the cleaning blade 11 is transferred to a toner circulation path (not shown) by the toner recovery member 27. It is configured to be conveyed and re-supplied to the toner storage unit 35.

  In an electrophotographic image forming apparatus such as the present invention, it is difficult to completely transfer toner. Therefore, in the color image forming apparatus, the transfer residual toner on the photoconductor 3 that has not been transferred to the intermediate transfer belt 4 may be mixed with other color toners, and is collected and discarded. Is desirable. On the other hand, in the monochrome image forming apparatus using the single color toner, since there is no color mixture of the toner, the transfer residual toner can be re-supplied to the toner storage unit 35 as described above, and the toner consumption can be reduced.

  In this case, the additive for the paper SH (mineral minerals and chemical compounds such as talc, kaolin, and calcium carbonate) adhering to the surface of the photosensitive member 3 is also supplied to the toner containing portion 35. Since the additive is sufficiently smaller than the particle size of the toner, it can be removed together with other foreign matters by the collecting roller 36 even when the toner container 35 is replenished. Therefore, it is possible to prevent an adverse effect on image quality due to the mixing of these additives into the toner.

[Third Embodiment]
Still another embodiment of the process unit 30 according to the present invention will be described. FIG. 5 is a schematic sectional view showing still another example of the process unit 30.

  In the process unit 30 of the present embodiment, in place of the doctor blade 46 as the restricting member in the first embodiment, a rotatable restricting roller 50 is disposed in contact with the developing roller 45, and further on the surface of the restricting roller 50. A regulating roller cleaning member 51 to be contacted was mounted.

  Originally, the foreign matter contained in the toner is removed by the collecting roller 36, but when the foreign matter that could not be completely removed is supplied to the developing roller 45, there is a possibility that the foreign matter is deposited on the doctor blade 46. As described above, if the restricting roller 50 that can be rotated is used in place of the doctor blade 46, even if foreign matter accumulates on the surface of the restricting roller 50, the restricting roller 50 is rotated by a predetermined angle to appropriately accumulate foreign matter. A fresh surface without any contact can be brought into contact with the developing roller 45. Further, along with the rotation of the regulating roller 50, the surface of the regulating roller 50 is cleaned by the regulating roller cleaning member 51. Therefore, maintenance of the regulating member can be facilitated.

  The embodiment of the present invention has been described above, but the present invention is not limited to the above-described embodiment, and it is needless to say that various modifications can be made without departing from the gist of the present invention. The image forming apparatus according to the present invention is not limited to the image forming apparatus shown in FIG. 1, and may be a monochrome image forming apparatus, other copiers, printers, facsimiles, or complex machines thereof.

3 Photoconductor (latent image carrier)
9 Developing Device 35 Toner Container (Developer Container)
36 Collection roller (collection member)
37 Supply roller (supply member)
45 Development roller (developer carrier)
46 Doctor blade (regulating member)

JP 2006-178034 A JP 2003-021695 A JP 2001-194904 A

Claims (14)

A rotatable developer carrier that carries a one-component developer on its surface and supplies the developer to a latent image carrier on which an electrostatic latent image is formed;
A regulating member that contacts the surface of the developer carrying member and frictionally charges the developer and regulates the layer thickness;
A developer accommodating portion for accommodating the developer;
Wherein disposed in the developer accommodating portion, a developing device having a supply member for supplying the developer carrying member a developing agent stored in the developer storage portion,
Wherein disposed between the developer carrying member and said feed member has a collecting member for supplying the supplied developer contact portion between the regulating member and said developer carrying member from said supply member,
A developing device characterized in that the collecting member is configured to collect foreign matter in the developer by its smooth surface . The developing device according to claim 1, wherein the collecting member has a cylindrical shape and is disposed so as to contact both the developer carrying member and the supply member. The developing device according to claim 2, wherein the collecting member rotates in a direction opposite to a direction in which a surface of the developer carrying member moves in a contact portion with the developer carrying member. The developing device according to claim 1, wherein the collecting member has a surface made of metal. The developing device according to claim 1-4 any one which is characterized in that to enable applying an AC voltage to the collecting member. The developing device according to claim 1-5 any one, characterized in that it comprises a cleaning member for removing foreign matter adhering to the surface of the collecting member. The collection member is configured to be rotatable,
The developer is prevented from leaking in the gap between the collecting member and the developing housing of the developing device upstream of the position facing the cleaning member in the rotational direction of the collecting member. Provide a seal ,
In the space defined by the collecting member, the cleaning member, the seal, and the developing housing, the foreign material removed from the surface of the collecting member by the cleaning member is collected. The developing device according to claim 6 . The removing member to the developer carrying member is contacted, claim 1-7, characterized in that the removal by the removing member the developer on the developer carrying member which has passed through the contact portion between the image bearing member 1 The developing device according to item. In the vicinity of the latent image bearing member, according to claim 1-8, characterized in that the developer was collected, and the collected developer is provided a first developer collecting member for supplying the developer accommodating portion The developing device according to any one of the above. In the vicinity of the regulating member, it claims 1-9, characterized in that the developer was collected, and the collected developer is provided a second developer collecting member for supplying the developer accommodating portion 2. The developing device according to item 1. In the vicinity of the removal member, claim 1-10, characterized in that the developer was collected, and the collected developer is provided a third developer collecting member for supplying the developer accommodating portion 2. The developing device according to item 1. It said restricting member is a rotatable cylindrical, the regulating member, a developing device according to any one of claims 1 to 11, wherein the contacting the cleaning member. Process unit of the developing device according to any one of claims 1 to 12, characterized in that a latent image bearing member for bearing a latent image. The developing device according to any one of claims 1 to 13 , a latent image carrier that carries a latent image, a transfer unit that transfers an image visualized with a developer to a recording medium, An image forming apparatus comprising: a fixing unit that fixes the image on a recording medium.

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