JP2015079097A - Developing device, and image forming apparatus and process cartridge including the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a developing device that can suppress the occurrence of defective images caused by a toner being collected by a magnetic brush in a mass state, and a process cartridge and an image forming apparatus including the developing device.SOLUTION: There is provided a developing device 5 including a developing case 59 that accommodates a two-component developer, a developing roller 51 that carries the two-component developer and conveys the developer to a developing area arranged opposite to a photoreceptor 1, an entrance seal 166 that is in contact with the surface of the photoreceptor 1 to suppress a toner from scattering to the outside of the developing device 5, and a seal bracket 167 that supports the entrance seal 166 to be fixed to the developing case 59, where the seal bracket 167 has a concavo-convex shape including groove parts 168 and projection parts 169 on the surface of a developing roller facing part 167f.

Description

  BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a developing device including a toner scattering prevention member for preventing toner scattering used in an image forming apparatus such as a copying machine, a fax machine, and a printer, and an image forming apparatus and a process cartridge including the developing device. It is.

  2. Description of the Related Art Conventionally, a developing device that visualizes a latent image formed on a latent image carrier with a developing device is known. For example, in order to visualize a latent image formed on a latent image carrier, there is a two-component developing device using a two-component developer composed of toner and a magnetic carrier as a developer. In this two-component developing device, a magnetic brush formed on the surface of the developer carrying member is brought into contact with the latent image carrying member in a developing region where the developer carrying member faces the latent image carrying member, and the latent image agent carrying member is placed on the latent image carrying member. Toner is supplied to the latent image to visualize the latent image.

  In the two-component developing device, a part of the toner supplied from the magnetic brush scatters to the outside without adhering to the latent image carrier in the developing region (hereinafter referred to as “toner scattering”). It is known that problems such as in-machine contamination due to toner and abnormal images occur. For this reason, conventionally, a flexible seal member generally called an inlet seal has been arranged upstream of the latent image carrier surface movement direction with respect to the development region where the latent image carrier and developer carrier face each other. (Patent Document 1 etc.). As this plastic seal member, the root side is fixed to the casing of the developing device, and the tip side is in contact with the surface of the latent image carrier, so that the gap between the casing of the developing device and the latent image carrier is closed, and the toner is scattered. What is reduced is known.

  Although the toner scattering can be reduced by arranging the flexible seal member, the toner that is prevented from scattering may adhere to the surface of the seal support member that supports the flexible seal member and fixes it to the casing. is there. Among the surfaces of the seal support member, the toner attached to the surface facing the developer carrying member (hereinafter referred to as “developer carrying member facing portion surface”) is brought into contact with or close to the magnetic brush. To be recovered. However, the toner adhering to the surface of the developer carrying member moves on the surface of the developer carrying member by the vibration of the apparatus until it is collected by the magnetic brush, and this movement causes the surface of the developer carrying member facing portion to move. The toner may concentrate on the upper part and form a lump.

  When the lump of toner is collected by the magnetic brush and reaches the developing region, it may adhere to the latent image carrier and become a poorly soiled image. In addition, when the toner mass collected by the magnetic brush does not adhere to the latent image carrier, the latent image on the surface portion of the latent image carrier facing the toner mass held by the magnetic brush is not developed and white toner is not developed. There is a possibility that a defective image is generated.

  Such a problem occurs not only in the case where the tip side of the member that closes the gap due to the tip side abutting on the latent image carrier is in contact with the latent image carrier, but also in the case where the tip side is close to the latent image carrier. obtain. The gap is not limited to the gap on the development area entrance side upstream of the latent image carrier in the surface movement direction with respect to the development area, and development on the downstream side of the latent image carrier in the surface movement direction with respect to the development area. A similar problem may occur even in the gap on the region exit side.

  The present invention has been made in view of the above-described problems, and an object of the present invention is to provide a developing device that can suppress the occurrence of a defective image due to toner being collected in a lump in a magnetic brush, and the developing device. A process cartridge and an image forming apparatus are provided.

  In order to achieve the above-mentioned object, the invention of claim 1 is characterized in that a two-component developer containing toner and a magnetic carrier is contained in the casing, and the two-component developer is applied by the magnetic force of the magnetic field generating means disposed inside. A developer carrier that carries the two-component developer to a development area facing the latent image carrier, and the tip is in contact with or close to the surface of the latent image carrier. A toner scattering suppression member that blocks the gap between the surface of the latent image carrier and the casing and prevents toner from scattering outside the developing device, and supports the toner scattering suppression member and is fixed to the casing. In the developing device having the scattering suppression supporting member, a portion of the surface of the scattering suppression supporting member facing the surface of the developer carrying member has an uneven shape.

  According to the present invention, it is possible to obtain an excellent effect that it is possible to suppress the occurrence of a defective image due to the toner being collected by the magnetic brush in a lump state.

FIG. 4 is an explanatory diagram of a developing device according to the embodiment, (a) is a schematic sectional view of the developing device, (b) is a top view of the surface of the seal bracket facing the developing roller of the developing device, and (c) is a developing roller. The perspective view of the opposing part surface. 1 is a schematic configuration diagram of an entire printer according to an embodiment. FIG. 3 is an enlarged explanatory diagram of an image forming unit. FIG. 4 is an explanatory view of the surface of the developing roller facing portion provided with a grid-like groove, (a) is a top view of the surface of the developing roller facing portion, and (b) is a perspective view of the surface of the developing roller facing portion. FIG. 10 is an explanatory view in the vicinity of a developing region where a developing roller and a photosensitive member provided in a developing device according to Modification 1 are opposed to each other. FIG. 10 is an enlarged explanatory view of the vicinity of a developing roller facing portion surface 167f of a seal bracket 167 provided in the developing device according to Modification 1. FIG. 10 is an explanatory view in the vicinity of a developing region where a developing roller and a photosensitive member provided in a developing device according to Modification 2 are opposed to each other. Explanatory drawing of the seal bracket with which the image development apparatus of the modification 3 is provided, and the fibrous protrusion provided in the seal bracket. FIG. 10 is an explanatory view in the vicinity of a developing region where a developing roller and a photosensitive member provided in a developing device according to Modification 4 are opposed to each other.

An embodiment in which the present invention is applied to a printer (hereinafter referred to as “printer 500”) as an image forming apparatus will be described below.
First, the entire printer 500 will be described. FIG. 2 is a schematic configuration diagram of the entire printer 500 of the present embodiment.

  The printer 500 includes four image forming units 6 (Y, C, M, K) for generating toner images of yellow, cyan, magenta, and black (hereinafter referred to as Y, C, M, and K). Yes. These image forming units 6 use different colors of Y toner, C toner, M toner, and K toner, but the other configurations are common to all four colors. In the following description, the subscripts Y, C, M, and K are omitted as appropriate.

In the printer 500 shown in FIG. 2, the optical writing unit 20 is provided below the four image forming units 6 (Y, C, M, K). The optical writing unit 20 serving as a latent image forming unit emits a laser beam L based on image information to each of the photoreceptors 1 (Y, C, M, K) of the four image forming units 6 (Y, C, M, K). ). Thereby, an electrostatic latent image corresponding to each color is formed on the surface of the photoreceptor 1 (Y, C, M, K).
The surface of the photoreceptor 1 (Y, C, M, K) on which the electrostatic latent image is formed is developed by a developing device 5 (Y, C, M, K), which will be described in detail later, and the photoreceptor 1 (Y, Y, C) is developed. Y, C, M, and K toner images are respectively formed on the surfaces of C, M, and K).

  As a configuration of the optical writing unit 20, in FIG. 2, the laser beam L emitted from the light source is irradiated to the photoreceptor 1 through a plurality of lenses and mirrors while being deflected by a polygon mirror 21 that is rotationally driven by a motor (not shown). I'm drawing things. However, as the configuration of the optical writing unit 20, an LED array system can be used in addition to such a polygon scanning system. The LED array method uses an LED as a light source instead of a laser diode as a light source in the polygon scanning method.

  On the lower side of the optical writing unit 20 in the figure, a first paper feed cassette 31 and a second paper feed cassette 32 are disposed so as to overlap in the vertical direction. In each of these paper feed cassettes, a plurality of transfer papers P as recording bodies are accommodated in a state of a bundle of transfer papers, and the first paper feed roller 31a, The second paper feed rollers 32a are in contact with each other.

When the first paper feed roller 31a is driven to rotate counterclockwise in the figure by driving means (not shown), the uppermost transfer paper P in the first paper feed cassette 31 is discharged from the first paper feed cassette 31. The The discharged transfer paper P is conveyed toward the paper feed path 33 arranged to extend in the vertical direction on the right side in FIG.
Further, when the second paper feed roller 32 a is driven to rotate counterclockwise in the figure by a driving means (not shown), the uppermost transfer paper P in the second paper feed cassette 32 is directed toward the paper feed path 33. Discharged. A plurality of transport roller pairs 34 are arranged in the paper feed path 33, and the transfer paper P sent to the paper feed path 33 is sandwiched between the rollers of the transport roller pair 34, while the paper feed path 33. 33 is conveyed from the lower side to the upper side in the figure.

  A registration roller pair 35 is disposed at the end of the paper feed path 33. The registration roller pair 35 temporarily stops the rotation of both rollers as soon as the transfer paper P sent from the transport roller pair 34 is sandwiched between the rollers. Then, the transfer paper P is sent out toward a secondary transfer nip described later at an appropriate timing.

  Above the four image forming units 6 (Y, C, M, and K) in FIG. 2, a transfer unit 40 that moves the endlessly counterclockwise in the figure while stretching an intermediate transfer belt 41 that is an intermediate transfer member. It is arranged. In addition to the intermediate transfer belt 41, the transfer unit 40 includes a belt cleaning device 42, a first bracket 43, a second bracket 44, and the like. Further, four primary transfer rollers 45 (Y, C, M, K), a secondary transfer backup roller 46, a belt driving roller 47, an auxiliary roller 48, a tension roller 49, and the like are also provided.

  The intermediate transfer belt 41 is endlessly moved in the counterclockwise direction in the drawing by the rotational driving of the belt driving roller 47 while being stretched around these eight rollers. The four primary transfer rollers 45 (Y, C, M, K) sandwich the intermediate transfer belt 41 moved endlessly in this way between the photoreceptor 1 (Y, C, M, K) and perform primary transfer respectively. A nip is formed. Then, a transfer bias having a polarity opposite to that of the toner (for example, plus) is applied to the back surface (loop inner peripheral surface) of the intermediate transfer belt 41. The intermediate transfer belt 41 sequentially passes through the primary transfer nips for Y, C, M, and K along with the endless movement thereof, and the photoreceptor 1 (Y, C, M, and K is provided on the front surface thereof. ) The Y, C, M, and K toner images above are superimposed and primarily transferred. As a result, a four-color superimposed toner image (hereinafter referred to as “four-color toner image”) is formed on the intermediate transfer belt 41.

  The secondary transfer backup roller 46 sandwiches the intermediate transfer belt 41 with the secondary transfer roller 50 disposed outside the loop of the intermediate transfer belt 41 to form a secondary transfer nip. The registration roller pair 35 described above sends the transfer paper P sandwiched between the rollers toward the secondary transfer nip at a timing at which the transfer paper P can be synchronized with the four-color toner image on the intermediate transfer belt 41. The four-color toner image on the intermediate transfer belt 41 is affected by the secondary transfer electric field formed between the secondary transfer roller 50 to which the secondary transfer bias is applied and the secondary transfer backup roller 46, and the influence of the nip pressure. The secondary transfer is performed on the transfer paper P in the secondary transfer nip. Then, combined with the white color of the transfer paper P, a full color toner image is obtained.

  Untransferred toner that has not been transferred to the transfer paper P adheres to the intermediate transfer belt 41 after passing through the secondary transfer nip. This is cleaned by the belt cleaning device 42.

  A fixing device 60 including a pressure roller 61 and a fixing belt unit 62 is disposed above the secondary transfer nip. The fixing belt unit 62 of the fixing device 60 moves the fixing belt 64 endlessly counterclockwise in FIG. 2 while being stretched by the heating roller 63, the fixing tension roller 65, and the fixing driving roller 66. The heating roller 63 includes a heat source 63a such as a halogen lamp, and heats the fixing belt 64 from the back side. The pressure roller 61 that is driven to rotate clockwise in the drawing is in contact with the surface of the fixing belt 64 that is heated in this manner from the front surface side. Thereby, a fixing nip where the pressure roller 61 and the fixing belt 64 abut is formed.

  The transfer paper P that has passed through the secondary transfer nip is separated from the intermediate transfer belt 41 and then fed into the fixing device 60. Then, in the process of being conveyed from the lower side to the upper side in the figure while being sandwiched by the fixing nip, the full-color toner image is fixed by being heated by the fixing belt 64 or being pressed by the pressure roller 61.

  The transfer sheet P subjected to the fixing process in this manner is discharged outside the apparatus after passing between the rollers of the discharge roller pair 67. A stack unit 68 is formed on the upper surface of the housing of the printer 500 main body, and the transfer paper P discharged to the outside by the discharge roller pair 67 is sequentially stacked on the stack unit 68.

  Above the transfer unit 40, four toner cartridges 100 (Y, C, M, K) are disposed as toner containers for storing Y, C, M, K toner. Y, C, M, and K toners (not shown) in the toner cartridge 100 (Y, C, M, and K) are respectively supplied to the developing devices 5 (Y, C, and M) of the image forming unit 6 (Y, C, M, and K). , K) as appropriate. These toner cartridges 100 (Y, C, M, K) are detachable from the main body of the printer 500 independently of the image forming unit 6 (Y, C, M, K).

In the printer 500 having the above configuration, the image forming means for forming a toner image is configured by the four image forming units 6 (Y, C, M, K), the optical writing unit 20, and the like.
Hereinafter, the image forming unit 6 will be described in more detail.

FIG. 3 is an enlarged explanatory view of one of the four image forming units 6 (Y, C, M, K).
As shown in FIG. 3, the image forming unit 6 includes a drum-shaped photoreceptor 1, a photoreceptor cleaning device 2, a static elimination device (not shown), a charging device 4, and a developing device 5. The image forming unit 6 can be integrally attached to and detached from the printer 500 as a process cartridge, and consumable parts can be replaced at a time.

  The charging device 4 uniformly charges the surface of the photoreceptor 1 that is rotated clockwise in the drawing by a driving unit (not shown). In FIG. 3, charging with a system in which the photosensitive member 1 is uniformly charged by contacting the photosensitive member 1 with a charging roller that is rotated counterclockwise in the drawing while a charging bias is applied by a power source (not shown). Device 4 is shown. Instead of the charging roller, a roller that contacts a charging brush may be used. Moreover, you may use what performs the charging process to the photoconductor 1 non-contact like a scorotron charger. The surface of the photosensitive member 1 uniformly charged by the charging device 4 is exposed and scanned by the laser beam L emitted from the optical writing unit 20 and carries an electrostatic latent image of a corresponding color.

  The developing device 5 includes a developing case 59 that is a casing that houses a developer G that is a two-component developer containing toner and a magnetic carrier. The developing device 5 forms a developer accommodating portion for accommodating the developer G therein by the developing case 59, and the developer accommodating portion in the developing case 59 is separated by the first conveying path 53 (first developing path) by the partition member 58. And a second transport path 54 (second developer accommodating portion). The developing device 5 includes a developing roller 51 above the first conveyance path 53. Further, the developing case 59 includes a developing opening 59 a for exposing a part of the surface of the developing roller 51 in the surface moving direction of the developing roller 51 so that the surface of the developing roller 51 faces the surface of the photoreceptor 1.

The developer G in the first transport path 53 is transported along the longitudinal direction of the developing roller 51 from the front side to the back side of the sheet by a first transport screw 55 as a first developer transport member. On the other hand, the developer G in the second transport path 54 is moved in the direction opposite to the first transport path 53 from the back side to the front side of the paper surface by the second transport screw 56 as the second developer transport member. Be transported.
The developer G in the middle of conveyance is detected by a toner concentration sensor 57 fixed to the bottom of the second conveyance path 54.

  The first transport path 53 and the second transport path 54 are isolated by a partition member 58 disposed in a region excluding both ends in the longitudinal direction, and communicate with each other in the longitudinal direction both ends where the partition member 58 is not interposed. That is, the developer G transported to the downstream end portion of the first transport path 53 by the first transport screw 55 passes through the opening at the back end portion of the partition member 58 and reaches the upstream end of the second transport path 54. And then conveyed by the second conveying screw 56. The developer G transported to the downstream end of the second transport path 54 by the second transport screw 56 passes through the opening at the front end of the partition member 58 to the upstream end of the first transport path 53. It flows, and is conveyed by the 1st conveyance screw 55 after that. Thus, in the developing device 5, a circulation path for the developer G is formed between the two transport paths (53 and 54).

Thus, the toner in the developer G circulating in the circulation path in the developing device 5 is attracted to the carrier by frictional charging with the magnetic carrier, and together with the magnetic carrier by the plurality of magnetic poles formed on the developing roller 51. It is carried on the developing roller 51.
The developing roller 51 includes a magnet roller 51b that is fixed inside and forms a plurality of magnetic poles on the peripheral surface of the roller, and a developing sleeve 51a that rotates around the magnet roller 51b. Then, when the developing sleeve 51a rotates around the magnet roller 51b on which a plurality of magnetic poles are formed, the developer G moves on the developing roller 51 (on the developing sleeve 51a) with the rotation.

The developer G carried on the developing roller 51 as the developer carrying member is conveyed along with the rotation of the developing roller 51 in the counterclockwise direction indicated by the arrow in the drawing, and the doctor blade 52 as the developer regulating member. Reach the position. Then, after the developer G on the developing roller 51 is regulated to an appropriate amount at this position, the developer G is transported to a developing area which is a position facing the photoreceptor 1. The toner is attracted to the electrostatic latent image formed on the photosensitive member 1 by the electric field (developing electric field) formed in the developing region.
In the developing device 5 of the present embodiment, as a developing bias applied to the developing roller 51, an AC component (alternating current component) developing bias is not applied, and only a DC component (direct current component) developing bias is applied. Has been. Accordingly, the configuration and control of the power supply unit that supplies the developing bias can be relatively simplified, and the occurrence of a blurred image can be reduced with respect to the magnetic carrier having a low resistance.

  The developing roller 51 in the developing device 5 of the present embodiment has an outer diameter set to 18 [mm] and a length in the longitudinal direction set to 326 [mm]. Further, the surface of the developing sleeve 51a of the developing roller 51 may be formed with V-shaped grooves at equal pitch intervals in the circumferential direction, or may be blasted. The gap (development gap) between the developing roller 51 and the photoreceptor 1 is set to 0.3 ± 0.05 [mm], and the gap (doctor gap) between the developing roller 51 and the doctor blade 52 is 0.5 ±. It is set to 0.04 [mm].

  The doctor blade 52 is a plate-like member made of a stainless material. Moreover, as for the 1st conveyance screw 55 and the 2nd conveyance screw 56, as for all, the screw part (blade) whose outer diameter is 14 [mm] on a shaft part whose outer diameter is 5 [mm] pitch. It is formed in a spiral shape. Although not shown, a plurality of magnetic poles are formed around the developing roller 51 (developing sleeve 51a) by the magnet roller 51b. The plurality of magnetic poles include a developing magnetic pole, a pumping magnetic pole (doctor-facing magnetic pole), an agent separating magnetic pole, a transporting magnetic pole, and the like. The developing magnetic pole is a magnetic pole formed at a position facing the photosensitive member 1, and the pumping magnetic pole (doctor facing magnetic pole) is formed from the position facing the first conveying screw 55 to the position facing the doctor blade 52. It is. The agent separation magnetic pole is a magnetic pole formed above the first conveyance path 53, and the conveyance magnetic pole is a magnetic pole formed between the development magnetic pole and the agent separation magnetic pole.

  In the developing device 5, first, the pumping magnetic pole acts on a magnetic carrier as a magnetic body, and a part of the developer G moving in the first transport path 53 is carried on the developing roller 51. Part of the developer G carried on the developing roller 51 is scraped off at the position of the doctor blade 52 (developer regulating member) and returned to the first transport path 53. On the other hand, the developer G carried on the developing roller 51 passing through the doctor gap between the doctor blade 52 and the developing roller 51 at the position of the doctor blade 52 affected by the magnetic force by the pumping magnetic pole is located at the position of the developing magnetic pole. To reach. The developer G that has reached the position of the developing magnetic pole rises to become a magnetic brush and slides on the photoreceptor 1 in the developing region. By this sliding contact, the toner in the developer G carried on the developing roller 51 adheres to the latent image on the photoreceptor 1.

  Thereafter, the developer G that has passed the position of the developing magnetic pole is transported to the position of the agent separating magnetic pole by the transporting magnetic pole. Then, at the position of the agent separating magnetic pole, the repelling magnetic field affects the magnetic carrier, and the developer G after the developing process carried on the developing roller 51 is detached from the developing roller 51. The detached developer G is returned again to the first transport path 53 and transported toward the downstream side of the first transport path 53, and is passed through the opening of the partition member 58 at the back end in FIG. To the upstream end of the second transport path 54. Further, the developer G that has moved to the upstream end of the second transport path 54 is transported by the second transport screw 56 together with the replenishment toner replenished from the toner replenishment port 144 via the toner replenishment path 143, and the second transport path 56. The downstream end of the path 54 is reached. And it moves to the upstream edge part of the 1st conveyance path | route 53 through the opening part of the partition member 58 of the near edge part in FIG. In the developing device 5, such a series of circulation of the developer G is repeated.

Next, the characteristic part of the developing device 5 of the present embodiment will be described.
FIG. 1 is an explanatory diagram of the developing device 5 of the present embodiment. 1A is a schematic cross-sectional view of the developing device 5, and FIG. 1B is a view of the surface 167f of the developing roller facing portion of the seal bracket 167 provided in the developing device 5 from the direction of arrow A in FIG. FIG. 1C is a perspective view of the developing roller facing portion surface 167f.

  As shown in FIG. 1A, the developing device 5 closes the gap between the surface of the photosensitive member 1 and the developing case 59 by having the tip end in contact with or close to the surface of the photosensitive member 1. An inlet seal 166 that suppresses the scattering of toner to the outside is provided. Further, a seal bracket 167 that supports the inlet seal 166 and is fixed to the developing case 59 is provided. Then, as shown in FIGS. 1B and 1C, a groove 168 and a convex 169 are formed on the surface 167f of the developing roller facing portion which is the portion of the surface of the seal bracket 167 facing the surface of the developing roller 51. It has an uneven shape.

Hereinafter, the advantage of the configuration having the uneven surface on the developing roller facing portion surface 167f will be described.
In the developing area, the developer G is rubbed against the photosensitive member 1, and at this time, toner separated from the carrier is adsorbed to the photosensitive member 1 and scattered to the space. The toner scattered below the development area in FIG. 1A, that is, upstream of the development area in the surface movement direction of the photoreceptor 1 is scattered outside the apparatus by the inlet seal 166 and the seal bracket 167. Is prevented. This is because the space connecting from the developing region to the upstream side in the rotation direction of the photoconductor 1 is blocked by the inlet seal 166 and the seal bracket 167 so that the scattered toner does not scatter to the upstream side in the rotation direction of the photoconductor 1. Is. The inlet seal 166 is a member that protrudes from the developing case 59 of the developing device 5, contacts the photoreceptor 1, and has flexibility.

Further, the toner scattered upward in FIG. 1A, which is on the downstream side in the surface movement direction of the photoreceptor 1 with respect to the development area, slides between the inner wall of the development case 59 and the developer G on the development roller 51. It is sucked into the developing device 5 by a suction air flow generated by rubbing.
The entrance seal 166 and the seal bracket 167 can prevent the toner scattered from within the developing region from scattering to the outside, but a part of the scattered toner adheres to the surface 167f of the seal bracket 167 facing the developing roller. Deposit with.

The toner deposited on the surface 167f of the developing roller facing portion (hereinafter referred to as “deposited toner”) increases in thickness as the number of sheets passing is increased, and if it exceeds a certain amount, it is scraped by the magnetic brush on the developing roller 51. Taken. Further, when an impact such as machine driving is transmitted to the seal bracket 167 and the seal bracket 167 vibrates, the accumulated toner moves on the surface 167f of the developing roller facing portion. At this time, the concentrated toner concentrates on a part of the surface 167f of the developing roller facing portion, and a lump may be formed. If the accumulated toner exceeds a certain amount in the state where the lump is formed, the lump of accumulated toner is scraped off by the magnetic brush on the developing roller 51.
When this timing overlaps with the time of printing, an abnormal image such as background smudges or toner dropping is generated.

  As a configuration for suppressing the occurrence of such a problem, the developing device 5 of the present embodiment has, as shown in FIGS. 1B and 1C, a surface 167 f of the developing roller facing portion of the seal bracket 167. The groove portion 168 is carved in a dice shape, and a convex portion 169 is formed. The depth of the groove 168 is sufficiently large with respect to the toner particle diameter. Since the surface 167f of the developing roller facing portion has an uneven shape, the movement range of the toner adhering to the surface is limited even if the toner moves due to vibration such as when the machine is driven.

  If the surface 167f of the developing roller facing portion 167f does not have an uneven shape and has a smooth surface, a lump of toner is easily formed as follows. That is, there is a possibility that the toner adhering to the developing roller facing portion surface 167f can freely move in the entire area of the developing roller facing portion surface 167f. For this reason, if there is a portion where the toner tends to concentrate on a part of the developing roller facing portion surface 167f due to the inclination of the developing roller facing portion surface 167f, the toner concentrates from the entire area of the developing roller facing portion surface 167f toward this portion. However, it is easy to form a lump of toner.

  On the other hand, in the developing device 5 of the present embodiment, the surface 167f of the developing roller facing portion has a concavo-convex shape, and the toner adhering to the surface of the convex portion 169 falls into the concave portion around the convex portion 169, or the groove 168 The toner adhering to the surface of the toner is blocked by the convex portion 169. Thus, by providing the developing roller facing portion surface 167f with a concavo-convex shape, the movement of the toner on the developing roller facing portion surface 167f can be restricted rather than the developing roller facing portion surface 167f being a smooth surface. Thereby, it is possible to suppress the toner from concentrating from the entire area of the developing roller facing portion surface 167f toward a part on the developing roller facing portion surface 167f, and it is possible to suppress the concentrated toner from forming a lump. Therefore, it is possible to suppress the toner adhering to the developing roller facing portion surface 167f from being collected by the magnetic brush in a lump state, and generating a defective image due to the toner being collected by the magnetic brush in a lump state. Can be suppressed.

When the developing roller facing portion surface 167f is flat, the toner may locally gather and form a large lump. However, in the developing device 5 of the present embodiment, the developing roller facing portion surface 167f is convex with the plurality of grooves 168. Since it is subdivided by the part 169, it does not become a large lump.
In the developing device 5 of the present embodiment, only the surface of the convex portion 169 is scraped off by the magnetic brush, so that the amount of toner scraped off is small and hardly forms an abnormal image. The toner in the groove 168 is not collected by the magnetic brush, but since the groove 168 has a sufficient depth, it takes time until the groove 168 is filled, and there is a problem even if the toner in the groove 168 is not collected. Does not occur.

In the developing device 5 of the present embodiment, the shape of the groove portion 168 is not limited to this configuration. The groove portion 168 has a dice-shaped groove portion 168 so that the square groove portions 168 and the convex portions 169 are arranged in a checkered pattern.
FIG. 4 is an explanatory diagram of the surface 167f of the developing roller facing portion provided with the grid-like groove portions 168. FIG. 4A is a top view of the surface 167f of the developing roller facing portion provided with the lattice-like groove 168, and FIG. 4B is a perspective view of the surface 167f of the developing roller facing portion provided with the lattice-like groove 168. FIG. FIG.

  As shown in FIG. 4, even if the grid-shaped grooves 168 are provided on the surface 167f of the developing roller facing portion, the movement range of the toner attached to the surface of the developing roller facing portion 167f is limited. For this reason, it is possible to suppress the toner adhering to the developing roller facing portion surface 167f from being collected by the magnetic brush in a lump state. However, the toner adhering to the groove portion 168 cannot move to the convex portion 169, but can move over the entire area of the continuous lattice-like groove portion 168, and the toner concentrates in a part of the groove portion 168 and concentrates. There is a risk that the toner that has been formed will form lumps.

  On the other hand, in the developing device 5 of the present embodiment shown in FIG. 1, the rectangular groove portions 168 and the convex portions 169 are arranged in a checkered pattern, and the range in which the toner attached to the convex portions 169 can move is one of them. It is limited to one convex part 169 and four groove parts 168 adjacent to it. In addition, the range in which the toner attached to the groove 168 can move is limited to the range of each groove 168. For this reason, the range in which the toner can move can be further subdivided, and the toner can be more reliably prevented from forming a lump.

By providing the developing device 5 of the present embodiment, the printer 500 can suppress the occurrence of a defective image due to the toner being collected by the magnetic brush in a lump state, and can perform good image formation.
In addition, since the image forming unit 6 that is a process cartridge includes the developing device 5 of the present embodiment, the development device 5 that can suppress the occurrence of a defective image due to the toner being collected by the magnetic brush in a lump state. Improve exchangeability

[Modification 1]
Next, a first modification of the developing device 5 according to the present invention (hereinafter referred to as “Modification 1”) will be described.
FIG. 5 is an explanatory diagram of the vicinity of the developing region where the developing roller 51 and the photosensitive member 1 provided in the developing device 5 according to the first modification are opposed to each other, and only the characteristic portions of the developing device 5 shown in FIG. 1 are left. And simplified. FIG. 6 is an enlarged explanatory view of the vicinity of the surface 167f of the developing roller facing portion of the seal bracket 167 provided in the developing device 5 of the first modification.

  The developing device 5 of Modification 1 uses a fibrous protrusion (hereinafter referred to as “fibrous protrusion 70”) instead of the uneven protrusion 169 formed on the surface 167f of the seal bracket 167 facing the developing roller. This is a configuration provided. In this configuration, the developing roller facing portion surface 167f where the fibrous protrusions 70 are not provided is a recess. The fibrous protrusion 70 has a role of adsorbing and collecting toner scattered from between the developing roller 51 and the doctor blade 52. The magnetic carrier C forming the magnetic brush is held on the developing sleeve 51a of the developing roller 51 by the magnetic force of the magnet roller 51b, and the toner T attached to the magnetic brush is electrostatically attached to and held on the magnetic carrier C. ing. For this reason, the magnetic carrier C forming the magnetic brush and the toner T held by the magnetic brush and contributing to development are not collected by the fibrous protrusions 70.

Further, since the fibrous protrusions 70 are on the developing roller facing portion surface 167f, the range in which the toner can move on the developing roller facing portion surface 167f is limited, and the toner is prevented from becoming a lump.
Further, as shown in FIG. 6, the tip of the fibrous protrusion 70 is in contact with the magnetic brush on the developing roller 51. Part of the toner T collected at the tip of the fibrous projection 70 is frictionally charged by coming into contact with the magnetic brush, and is collected in the magnetic brush by scraping from the fibrous projection 70 by electrostatic force or a magnetic brush. Is done.
The toner collected by the fibrous protrusions 70 is unlikely to be agglomerated and can be periodically collected in the developing case 59 of the developing device 5 with a magnetic brush. Furthermore, it does not move and localize due to vibrations such as machine driving, so that it is difficult to produce an abnormal image.

[Modification 2]
Next, a second modification (hereinafter referred to as “Modification 2”) of the developing device 5 according to the present invention will be described.
FIG. 7 is an explanatory view of the vicinity of the developing region where the developing roller 51 and the photosensitive member 1 provided in the developing device 5 according to the second modification are opposed to each other, and only the characteristic portions of the developing device 5 shown in FIG. 1 are left. And simplified.

  As shown in FIG. 7, in the developing device 5 of the second modification, the protrusion support seal member 71 with the fibrous protrusions 70 is attached to the developing roller facing surface 167 f of the seal bracket 167. The protrusion support seal member 71 is in contact with the photoreceptor 1 and functions as a toner scattering suppression member. By appropriately arranging the gap between the fibrous protrusion 70 and the magnetic brush on the developing sleeve 51a, the toner adhering to the fibrous protrusion 70 can always be scraped off with the magnetic brush, as in the first modification.

  In the developing device 5 of the first modification described with reference to FIGS. 5 and 6, scattered toner accumulates between the inlet seal 166 and the seal bracket 167, and the deposited toner is applied to the photoreceptor 1 by the potential of the photoreceptor 1. It may be adsorbed (developed). When the accumulated toner is adsorbed to the photosensitive member 1, there is a problem that an abnormal image such as a background stain or a toner drop image is caused. On the other hand, in the developing device 5 of the second modification shown in FIG. 7, the protrusion support seal member 71 abuts on the photosensitive member 1 and functions as a toner scatter suppressing member in the same manner as the entrance seal. Thereby, it is possible to prevent the occurrence of an abnormal image due to the accumulation of scattered toner between the toner scattering suppressing member and the seal bracket 167.

[Modification 3]
Next, a third modified example (hereinafter referred to as “modified example 3”) of the developing device 5 according to the present invention will be described.
FIG. 8 is an explanatory diagram of the seal bracket 167 provided in the developing device 5 of Modification 3 and the fibrous protrusions 70 provided on the seal bracket 167, so that the longitudinal direction of the developing device 5 is the horizontal direction. It is.
The developing device 5 of Modification 3 has a configuration in which the length of the fibrous protrusions 70 is different in the longitudinal direction of the developing device 5 that is the main scanning direction orthogonal to the surface movement direction of the developing roller 51.

As described in the modification example 2, in order to scrape the toner attached to the fibrous protrusions 70 with the magnetic brush, the gap between the fibrous protrusions 70 and the magnetic brush needs to be an appropriate interval. However, when it is difficult to develop the central portion in the main scanning direction due to a problem such as deflection, the distance between the doctor blade 52 in the central portion and the developing sleeve 51a of the developing roller 51 is made wider than the front side or the rear side. Things have been done. At this time, since the pumping amount of the developer G changes in the main scanning direction, the length of the magnetic brush also changes in the main scanning direction. In response to such a problem, the magnetic brush and the fibrous protrusion 70 have an appropriate gap by changing the length of the fibrous protrusion 70 in the main scanning direction as in the developing device 5 of Modification 3. The toner adhered to the fibrous protrusions 70 can be scraped off with a magnetic brush.
Note that the configuration of Modification 3 can be applied as the configuration of the fibrous protrusions 70 included in the developing device 5 of Modification 1 and Modification 2 described above and the developing device 5 of Modification 4 described later.

The toner adhering to the surface 167f of the seal bracket 167 facing the developing roller is a magnetic brush during forward rotation of the developing roller 51 that moves in the counterclockwise direction in FIGS. 1A, 5 and 7 during image formation. Is recovered by. As described above, the toner on the surface 167f of the developing roller facing portion can be collected during the forward rotation operation, but the reverse rotation that moves the surface of the developing roller 51 in a direction opposite to that during the forward rotation operation at a timing other than during image formation. It is preferable to perform the operation.
The toner is collected even in the forward rotation operation. However, in the reverse rotation operation, the magnetic brush spikes are different from the normal rotation operation, so it is possible to collect the accumulated toner that cannot be collected in the forward rotation operation. Become.

[Modification 4]
Next, a fourth modification (hereinafter referred to as “Modification 4”) of the developing device 5 according to the present invention will be described.
FIG. 9 is an explanatory view of the vicinity of the developing area where the developing roller 51 and the photosensitive member 1 provided in the developing device 5 according to the modified example 4 face each other, and only the characteristic portions of the developing device 5 shown in FIG. And simplified.

As shown in FIG. 9, the developing device 5 of Modification 4 extends such that the fibrous protrusions 70 are opposed to the forward rotation direction (the arrow direction in the drawing) of the developing sleeve 51 a included in the developing roller 51. . Specifically, the fibrous protrusion 70 is located on the upstream side in the surface movement direction with respect to the surface movement direction (the arrow direction in the drawing) of the developing roller 51 when compared with the fibrous root side. It is arranged to be located.
By disposing the fibrous protrusions 70 so as to face each other in the forward rotation direction of the developing roller 51, the fibrous protrusions 70 are tilted to the downstream side in the surface movement direction of the developing roller 51 due to the airflow generated by the rotation of the developing sleeve. This can be suppressed. Therefore, the scattered toner can be collected more reliably.
Further, by performing a reverse operation after image formation, it becomes possible to collect the accumulated toner at a location on the surface of the fibrous projection 70 that cannot be collected by the normal rotation operation, and the scattered toner attached to the fibrous projection 70 Can be efficiently recovered.

What has been described above is merely an example, and the present invention has a specific effect for each of the following modes.
(Aspect A)
The two-component developer is surfaced by the magnetic force of a casing such as a developing case 59 containing therein a two-component developer such as developer G containing toner and a magnetic carrier, and a magnetic field generating means such as a magnet roller 51b disposed therein. And a developer carrying member such as a developing roller 51 that transports the two-component developer to a developing region facing the latent image carrier such as the photosensitive member 1 and a tip portion of the surface of the latent image carrier. A toner scattering suppressing member such as an inlet seal 166 that closes a gap between the surface of the latent image carrier and the casing by contacting or approaching the toner and suppresses the toner from scattering to the outside of the developing device, and the toner scattering suppression In a developing device such as the developing device 5 having a toner scattering suppression support member such as a seal bracket 167 that supports the member and is fixed to the casing, the surface of the toner scattering suppression support member Surface facing the portion of the image carrying member has an uneven shape of the grooves such as 168 and protrusions 169 (the developing roller opposing portion surface 167f, etc.).
According to this, as described in the above-described embodiment, the surface of the toner scatter suppression support member that has a concavo-convex shape in the portion facing the surface of the developer carrier restricts the movement of the toner attached to this portion. It becomes possible to do. If the surface of the toner scattering suppression support member that faces the surface of the developer carrying member (hereinafter referred to as “developer carrying member facing portion surface”) has no uneven surface and has a smooth surface, It is easy to form a lump of toner. That is, there is a possibility that the toner adhering to the surface of the developer carrying member facing portion freely moves over the entire surface of the developer carrying member facing portion when the toner scattering suppressing support member vibrates. For this reason, if there is a portion where the toner tends to concentrate on a part of the surface of the developer carrying member facing portion due to the inclination of the surface of the developer carrying member facing portion or the like, The toner concentrates and it is easy to form a lump of toner.
On the other hand, if the surface of the developer-carrying member facing portion has a concavo-convex shape, the toner adhered on the surface of the convex portion falls into the concave portion around the convex portion, or the toner adhered to the surface in the concave portion The movement is blocked by the convex part. As described above, the surface of the developer carrying member facing portion is provided with a concavo-convex shape, so that the movement of the toner on the surface of the developer carrying member facing portion is limited rather than the surface of the developer carrying member facing portion being a smooth surface. Can do. Thereby, it is possible to suppress the concentration of toner from the entire area of the surface of the developer carrying member facing portion toward a part on the surface of the developer carrying member facing portion, and it is possible to suppress the concentrated toner from forming a lump. Therefore, it is possible to suppress the toner adhering to the surface of the developer carrying member facing portion from being collected by the magnetic brush in a lump state, and generating a defective image due to the toner being collected by the magnetic brush in a lump state Can be suppressed.
(Aspect B)
In the aspect A, the amount of the two-component developer such as the developer G carried on the developer carrying member facing the surface on the upstream side in the surface movement direction of the developer carrying member such as the developing roller 51 with respect to the developing region is set. A developer restricting member such as a doctor blade 52 to be regulated is provided, and a toner scattering suppressing member such as an inlet seal 166 is developed downstream of the developer carrying member in the surface movement direction of the developer carrying member and with respect to the developing region. And a developing region entrance toner scattering suppression member disposed upstream of the surface of the agent carrier in the moving direction.
According to this, as described in the above embodiment, the toner is not generated on the suction airflow side between the inner wall of the casing such as the developing case 59 and the developer carrying member, and the toner is generated on the inlet side of the developing region where toner scattering is likely to occur. The occurrence of scattering can be suppressed.
(Aspect C)
In any one of the aspects A and B, a concave portion and a convex portion such as a square groove portion 168 provided in a portion of the surface of the toner scattering suppression supporting member such as the developing roller facing portion surface 167f facing the surface of the developer carrier. The concavo-convex shape of the checkered pattern is formed by the convex portions such as 169.
According to this, as described in the above embodiment, the range in which the toner can move in the portion of the surface of the toner scattering suppression supporting member that faces the surface of the developer carrier can be further subdivided, and more reliably. It is possible to suppress the toner from forming lumps.
(Aspect D)
In any of the aspects A and B, the fibrous protrusions such as the fibrous protrusions 70 on the surface of the toner scattering suppression supporting member such as the developing roller facing portion surface 167f facing the surface of the developer carrier. To form an uneven shape.
According to this, as described in the first modification, the range in which the toner can move on the portion of the surface of the toner scattering suppression support member that faces the surface of the developer carrier is limited by the fibrous protrusions. In addition, the toner is prevented from becoming a lump.
(Aspect E)
In any of the aspects A and B, the toner scattering suppression member such as the inlet seal 166 is provided on the surface of the toner scattering suppression supporting member such as the seal bracket 167 and the like facing the surface of the developer carrying member such as the developing roller 51. An uneven shape is formed by disposing a fibrous protrusion such as the fibrous protrusion 70 on the surface of the toner scattering suppressing member that faces the surface of the developer carrying member.
According to this, as described in the second modification, it is possible to prevent the occurrence of abnormal images due to the accumulation of scattered toner between the toner scattering suppression member and the toner scattering suppression support member.
(Aspect F)
In any one of the aspects D or E, the fibrous protrusions are formed depending on the positions in the direction parallel to the width direction such as the main scanning direction which is the direction perpendicular to the surface moving direction on the surface of the developer carrying member such as the developing roller 51. The lengths of the fibrous protrusions such as the object 70 are different.
According to this, as described in the third modification, the length of the fibrous protrusion is set to a length corresponding to the amount of the developer pumped up on the developer carrier that varies depending on the position in the width direction. Can be set. Thereby, the magnetic brush and the fibrous protrusion maintain an appropriate gap, and the toner attached to the fibrous protrusion by the magnetic brush can be more reliably collected.
(Aspect G)
In any one of the aspects D to F, the fibrous protrusions such as the fibrous protrusions 70 have a fibrous root relative to the surface movement direction during image formation of the developer carrier such as the developing roller 51. It is arranged so that the tip side is located on the upstream side in the surface movement direction than the side.
According to this, as described in the fourth modification, it is possible to prevent the fibrous protrusions from falling down on the downstream side in the surface movement direction of the developer carrier due to the airflow generated by the surface movement of the developer carrier. Thus, the scattered toner can be collected more reliably.
(Aspect H)
At least the latent image carrier and the developing unit in an image forming apparatus including a latent image carrier such as the photosensitive member 1 that carries the latent image, and a developing unit that develops the latent image on the latent image carrier. In the process cartridge such as the image forming unit 6 that is held on a common holding body as a unit and is detachable from the main body of the image forming apparatus such as the printer 500, the developing according to any one of the aspects A to G A developing device such as the device 5 is used.
According to this, as described in the above embodiment, it is possible to improve the exchangeability of the developing device that can suppress the occurrence of a defective image due to the toner being collected by the magnetic brush in a lump state.
(Aspect I)
At least a latent image carrier such as the photosensitive member 1, charging means such as a charging device 4 for charging the surface of the latent image carrier, and an optical writing unit for forming an electrostatic latent image on the latent image carrier In an image forming apparatus such as a printer 500 having a latent image forming unit 20 or the like and a developing unit for developing an electrostatic latent image into a toner image, the developing unit is described in any one of aspects A to G. A developing device such as the developing device 5 is used.
According to this, as described in the above embodiment, it is possible to suppress the occurrence of a defective image due to the toner being collected by the magnetic brush in a lump state, and good image formation can be performed.

DESCRIPTION OF SYMBOLS 1 Photoconductor 2 Photoconductor cleaning apparatus 4 Charging apparatus 5 Developing apparatus 6 Image forming unit 20 Optical writing unit 21 Polygon mirror 31 First paper feed cassette 31a First paper feed roller 32 Second paper feed cassette 32a Second paper feed roller 33 Feeding path 34 Conveying roller pair 35 Registration roller pair 40 Transfer unit 41 Intermediate transfer belt 42 Belt cleaning device 43 First bracket 44 Second bracket 45 Primary transfer roller 46 Secondary transfer backup roller 47 Belt drive roller 48 Auxiliary roller 49 Tension Roller 50 Secondary transfer roller 51 Developing roller 51a Developing sleeve 51b Magnet roller 52 Doctor blade 53 First conveying path 54 Second conveying path 55 First conveying screw 56 Second conveying screw 57 Toner concentration sensor 58 Partition member 59 Developing case 5 a development opening 60 fixing device 61 pressure roller 62 fixing belt unit 63 heating roller 63a heat generation source 64 fixing belt 65 fixing tension roller 66 fixing driving roller 67 discharge roller pair 68 stack unit 70 fibrous projection 71 projection support seal Member 100 Toner cartridge 143 Toner supply path 144 Toner supply port 166 Entrance seal 167 Seal bracket 167f Developing roller facing surface 168 Groove 169 Protrusion 500 Printer C Magnetic carrier G Developer L Laser light P Transfer paper T Toner

Japanese Patent No. 3492858 JP 10-307474 A JP 2012-118359 A

Claims (9)

A casing containing therein a two-component developer containing toner and a magnetic carrier;
A developer carrier that carries the two-component developer on the surface by the magnetic force of a magnetic field generating means disposed therein, moves the surface, and conveys the two-component developer to a development region facing the latent image carrier;
A toner scattering suppressing member that prevents the toner from scattering to the outside of the developing device by closing the gap between the surface of the latent image bearing member and the casing by the front end portion contacting or approaching the surface of the latent image bearing member. When,
In the developing device having the scattering suppression support member that supports the toner scattering suppression member and fixes the toner scattering suppression member to the casing,
A developing device having a concavo-convex shape in a portion of the surface of the toner scattering suppression supporting member facing the surface of the developer carrying member. The developing device according to claim 1,
A developer regulating member that opposes the upstream surface of the developer carrying member in the surface movement direction with respect to the developing region and regulates the amount of the two-component developer carried on the developer carrying member;
The toner scattering suppressing member is a developer disposed downstream of the developer regulating member in the surface movement direction of the developer carrier and upstream of the developer region in the surface movement direction of the developer carrier. A developing device which is a region entrance toner scattering suppression member. The developing device according to claim 1 or 2,
A developing device characterized in that a checkerboard-like uneven shape is formed by a rectangular concave portion and a convex portion provided in a portion of the surface of the toner scattering suppression supporting member facing the surface of the developer carrying member. The developing device according to claim 1 or 2,
A developing device characterized in that a fibrous protrusion is disposed on a portion of the surface of the toner scattering suppression supporting member facing the surface of the developer carrying member to form the uneven shape. The developing device according to claim 1 or 2,
The toner scattering suppression member is provided on a portion of the surface of the toner scattering suppression supporting member facing the surface of the developer carrier,
A developing device characterized in that a fibrous protrusion is disposed on a portion of the surface of the toner scattering suppressing member facing the surface of the developer carrying member to form the uneven shape. In the developing device according to claim 4 or 5,
The developing device characterized in that the length of the fibrous projection differs depending on the position in the direction parallel to the width direction which is a direction orthogonal to the surface moving direction on the surface of the developer carrying member. The developing device according to any one of claims 4 to 6,
The fibrous protrusion is arranged such that the tip side is positioned upstream of the fibrous base side in the surface movement direction with respect to the surface movement direction during image formation of the developer carrier. A developing device. A latent image carrier for carrying a latent image;
In an image forming apparatus comprising a developing means for developing a latent image on the latent image carrier, at least the latent image carrier and the developing means are held as a single unit on a common holder, and the image forming apparatus main body In the process cartridge that can be attached and detached,
A process cartridge using the developing device according to claim 1 as the developing means. At least a latent image carrier;
Charging means for charging the surface of the latent image carrier;
Latent image forming means for forming an electrostatic latent image on the latent image carrier;
In an image forming apparatus having developing means for developing the electrostatic latent image into a toner image,
An image forming apparatus using the developing device according to claim 1 as the developing unit.