JP5526889B2 - Developing device and image forming apparatus - Google Patents

Description

  The present invention provides a developer carrying member for carrying a developer on the surface and developing the latent image on the surface of the latent image carrying member disposed at a position facing the latent image carrying member, and a developer carrying the developer. The present invention relates to a developing device developing device including a transport member, a developer, a developer carrier, and a developer container that holds the developer transport member therein, and an image forming apparatus including the developing device.

  Conventionally, in an electrophotographic system using a powdery developer such as toner, toner or the like may be scattered during image formation, and the inside and outside of the apparatus may be contaminated. Therefore, in order to cope with this problem, a duct having an opening is provided in the machine, and the powder is sucked by a fan.

  In Patent Document 1, in an electrophotographic image forming apparatus having a developing unit for containing a developer, a duct having a suction port capable of sucking air is integrally formed so as to face a developing nip of the developing unit. What is provided is described. In this example, the duct is provided integrally with the developing device so as to oppose the nip portion between the developer carrying member and the latent image carrying member, thereby realizing a small structure capable of efficiently sucking scattered toner.

  However, in the case of providing a mechanism for sucking toner by generating an air flow in a direction opposite to the nip portion as described above and installing the opening portion facing upward, abnormal toner dropping, for example, deteriorated toner lump When the toner drops, since the toner lump and the air flow travel in the same direction, the toner may be clogged in the flow path and the toner suction performance may deteriorate.

  FIG. 5 is a schematic view showing a cross section of a conventional developing device. The duct 110 is installed with a gap 113 and a latent image carrier 115 therebetween. At this time, the suction unit 111 generates a downward airflow B on the paper surface of FIG. 5, and the airflow B sucks scattered toner around the latent image carrier 115. The sucked toner is conveyed by the airflow C of the conveyance unit 112. Here, although the airflow C in the conveyance part 112 flows in the back direction in the figure, this may be another direction. In this state, if the toner lump 114 that cannot be conveyed by the airflow B enters the suction unit 111, the suction unit 111 is clogged with the toner lump 114.

  As a means for avoiding this, it is possible to prevent the dropped toner from entering the duct by changing the direction of the duct. In this case, a mechanism for receiving the dropped toner is required. In addition, the dropped toner is scattered on the spot to contaminate the surroundings.

  The present invention has been made in view of the above problems, and can form a flow path capable of conveying scattered toner without clogging even when a large amount of toner or toner lump falls, thereby preventing toner contamination inside and outside the apparatus. It is an object of the present invention to provide a developing storage and an image forming apparatus using the developing device.

According to a first aspect of the present invention, in the developing device, a developer is carried on the surface, and is disposed at a location facing the latent image carrier and develops a latent image on the surface of the latent image carrier; In a developing device comprising: a developer conveying member that conveys a developer; and a developer container that holds the developer, the developer carrier, and the developer conveying member inside,
Extending along the axial direction of the latent image carrier between the developer container and the latent image carrier, and forming a flow path through which airflow along the extending direction can flow .
A protruding portion that prevents the developer from leaking from between the latent image carrier and the developer carrier is provided in a portion that forms the flow path, and the developer is stored below the protruding portion. A proximity portion to be held is provided close to the latent image carrier,
It is characterized by this.

A second aspect of the present invention, in the developing device, the pre SL channel, while arranged in the direction of rotation downstream of the opposing portion of the latent image bearing member and the developer carrying member, the latent image carrier and the developer carrier It is a thing of Claim 1 provided in the lower side from the nip part which a body forms .

According to a third aspect of the present invention, in the developing device according to the first or second aspect, a portion of the wall surface of the developer container that forms the flow path includes a toner receiving portion at a lower portion and an opening portion at an upper portion. It is characterized by having a cross-sectional bag shape .

A fourth aspect of the present invention, in the developing device according to any one of claims 1 to 3, the opposite ends in the axial direction of the latent image bearing member before Symbol passage with a sealing member sealing The sealing material is brought into contact with the latent image carrier to seal both ends of the flow path .

  According to a fifth aspect of the present invention, in the developing device according to any one of the first to fourth aspects, an airflow generating means for generating an airflow in the flow path is provided.

  A sixth aspect of the present invention is an image forming apparatus comprising the developing device according to any one of the first to fifth aspects.

  According to the present invention, since the toner transport flow path is formed by the wall surface integral with the developer container and the latent image carrier, the toner scattered from the opposing portion of the developer carrier and the latent image carrier is allowed to flow directly. In addition to being able to guide into the road, since there is no opening portion that is relatively narrow with respect to the toner scattering location, the opening portion is not clogged with toner, and thus the contamination of the image forming apparatus due to toner scattering can be prevented. .

1 is a cross-sectional view illustrating an image forming apparatus according to an embodiment. It is sectional drawing which shows the structure of the developing device which concerns on an Example. 1 is a perspective view illustrating a developing device according to an embodiment. It is an expanded sectional view which shows operation | movement of the developing device which concerns on an Example. It is sectional drawing which shows the conventional image development apparatus.

  The developing device according to the present invention has a developer carried on the surface thereof, disposed at a position facing the latent image carrier, and developing the latent image on the surface of the latent image carrier, and the developer And a developer container that holds the developer, the developer carrying member, and the developer carrying member therein, and a developer container that conveys the developer container and the latent image carrier. A flow path is formed along the axial direction of the latent image carrier between which the airflow along the extending direction can flow. According to the present invention, since the flow path is formed by the wall surface integral with the developer container and the latent image carrier, the toner scattered from the opposed portion of the developer carrier and the latent image carrier is directly guided into the flow path. be able to. Further, since there is no opening that is relatively narrow with respect to the toner scattering location as in the conventional toner suction flow path, the problem of toner clogging in the opening can be prevented.

  Further, in the developing device according to the present invention, the developer carrying member and the latent image carrying member rotate in opposite directions, and the flow path rotates more than the opposed portion of the developer carrying member and the latent image carrying member. It can be arranged downstream in the direction. According to this example, the toner scattering outside the developing device can be suppressed by providing the flow path downstream in the rotation direction of the developer bearing member and the latent image bearing member in which the toner easily scatters.

  Further, the flow path of the developing device according to the present invention can be provided below a nip portion formed by the developer carrier and the latent image carrier. According to this example, since the flow path is provided below the opposed portion of the developer carrier and the latent image carrier, toner that cannot be conveyed by the airflow can be stored in the flow path.

  Moreover, the part which forms the said flow path among the wall surfaces of the said developer container of the developing device which concerns on this invention can be made into a cross-sectional bag shape which equips a lower part with a toner receiving part, and equips an upper part with an opening part. According to this example, since the flow path has a bag shape in cross section, more toner can be stored without adhering toner to the latent image carrier side.

  The developing storage according to the present invention includes an air flow generating means for generating an air flow in the flow path.

  An image forming apparatus according to the present invention includes the developing device. According to the image forming apparatus of this example, it is possible to prevent the image forming apparatus from being soiled due to toner scattering.

  A basic configuration and operation of a copying machine as an image forming apparatus according to an embodiment will be described below with reference to the drawings. FIG. 1 is a schematic configuration diagram illustrating a configuration of an image forming apparatus according to an embodiment.

  The image forming apparatus according to the present embodiment includes a sheet feeding unit in which a sheet feeding cassette 20 that stores a sheet as a recording material is arranged at a lower portion of the apparatus main body 100, and an image forming unit 30 is disposed above the sheet feeding unit. . The image forming unit 30 includes photosensitive drums 1Y, 1M, 1C, and 1K (hereinafter referred to as photosensitive drums 1 unless otherwise specified) and developing devices 9Y, 9M, 9C, and 9K (image carriers). 4) image forming units 5Y, 5M, 5C, 5K (also referred to as image forming unit 5) equipped with a developing device 9) and a plurality of rollers 11, 12, 13 An intermediate transfer belt 10 as an intermediate transfer member constituted by an endless belt, an optical writing unit 4 which is a latent image forming device for forming a latent image on each image carrier, a fixing device 23 for fixing a toner image on a sheet, and the like. Is arranged and configured. A transport path for transporting paper is formed between the paper feed cassette 20 and the fixing device 23. In the figure, 21 indicates a calling roller, and 22 indicates a registration roller.

  A space between the roller 11 and the roller 12 of the intermediate transfer belt 10 corresponds to a lower side belt running side of the intermediate transfer belt 10. The intermediate transfer belt 10 is provided with a secondary transfer roller 16 serving as a secondary transfer device facing a roller 13 at a portion facing the roller 13, and cleaning the belt surface at a portion facing the roller 11. A device 15 is provided.

  The image forming unit 30 is disposed below the intermediate transfer belt 10 by being disposed so as to face the lower running side. Each image forming unit includes a photosensitive drum 1 in contact with the intermediate transfer belt 10. Around each photosensitive drum 1, a charging device 7, a developing device 9, and a cleaning device 17 are arranged. A transfer roller 14 as a transfer device that performs primary transfer is provided inside the intermediate transfer belt 10 at a position where each photosensitive drum 1 is in contact with the intermediate transfer belt 10.

  In the image forming unit 5Y, as described above, the photosensitive drum 1, the developing device 9, the cleaning device 17, and the charging device 7 are integrally configured to form a process cartridge. The other image forming units 5M, 5C, and 5K have the same configuration.

  The optical writing unit 4 irradiates the surface of each photosensitive drum 1 with light-modulated laser light L to form a latent image for each color on the surface of the image carrier. In this embodiment, the image forming unit 30 It is arranged below.

  As shown in FIG. 1, toner bottles 31Y, 31M, 31C, and 31K (hereinafter referred to as toner bottle 31 unless otherwise specified) are usually provided in the upper portion of apparatus main body 100. The toner is replenished only by replacement, and the entire process cartridge is replaced only when the process cartridge such as the photosensitive drum 1 or the charging device 7 is replaced.

  In FIG. 1, a toner bottle 31 is arranged on the upper side of each machine for each color, and the toner is transported to the process cartridges for each color on the lower side to replenish the toner. With such a configuration, it is usually only necessary to replace the toner bottle, so that the cost of the user can be reduced. Further, since the number of times of opening / closing and taking in / out of other parts of the apparatus is reduced, it is possible to prevent toner scattering at the shutter portion and the like, thereby improving maintenance.

  When the image forming operation starts, the photosensitive drum 1 of each image forming unit is rotated clockwise by a driving device (not shown), and the surface of each photosensitive drum 1 is uniformly charged to a predetermined polarity by the charging device 7. . The surface of each charged photosensitive drum 1 is irradiated with laser light L from the optical writing unit 4 to form an electrostatic latent image on each surface. At this time, for example, the image information read on each photoconductor drum 1 by the arithmetic device with the image read by the scanner 40 is monochromatic image information obtained by separating a desired full-color image into color information of yellow, cyan, magenta, and black. is there. The electrostatic latent image formed in this way is visualized as a toner image by toner stored in each developing device 9 when passing between each photosensitive drum 1 and the developing device 9.

  One of the plurality of rollers around which the intermediate transfer belt 10 is wound is rotationally driven in a counterclockwise direction by a driving device (not shown), thereby driving the intermediate transfer belt 10 to run and the other rollers being driven to rotate. Let On the intermediate transfer belt 10 that travels in this manner, the toner images of the respective colors formed by the respective image forming units are sequentially superimposed and transferred by the transfer roller 14, and a full-color toner image is carried on the surface of the intermediate transfer belt 10. .

  Residual toner adhering to the surface of each photoconductive drum 1 after transferring the toner image is removed from the surface of each photoconductive drum 1 by the cleaning device 17, and the surface of the photoconductive drum 1 is discharged by a static eliminator (not shown). The surface potential is initialized to prepare for the next image formation.

  On the other hand, the paper fed from the paper feed cassette 20 is sent to the transport path, and the roller 13 and the secondary transfer roller 16 are fed by the registration roller pair 22 disposed on the paper feed side with respect to the secondary transfer roller 16. Feed to the opposite part. At this time, a transfer voltage having a polarity opposite to the toner charging polarity of the toner image on the surface of the intermediate transfer belt 10 is applied to the secondary transfer roller 16, thereby collectively transferring the toner images on the surface of the intermediate transfer belt 10 onto the sheet. Transcript. The sheet on which the toner image has been transferred is conveyed to the fixing device 23, and heat and pressure are applied when passing through the fixing device 23 to melt and fix the toner image. Then, the sheet on which the toner image is fixed, that is, the printed sheet, is conveyed to a discharge roller 24 positioned at the end of the conveyance path provided near the upper part of the apparatus main body 100, and a stacking unit configured on the upper part of the apparatus main body 100. To discharge. The toner remaining on the intermediate transfer belt 10 after the toner image is transferred to the paper is removed by the belt cleaning device 15.

  The toner removed by the belt cleaning device 15 and the cleaning device 17 in each of the image forming units 5Y, 5M, 5C, and 5K is transported by the transport coil and collected in the waste toner collecting container 45.

  The copying machine configured in this manner is provided with four image forming units 5Y, 5M, 5C, and 5K facing the intermediate transfer belt 10, and sequentially transfers the toner images of the respective colors onto the intermediate transfer belt 10, The image forming time can be greatly reduced as compared with a type in which a single image forming unit has a four-color developing device, transfers a toner image on an intermediate transfer belt, and then transfers it onto a sheet. In addition, since the stacking unit is formed on the upper part of the apparatus main body 100, the stacking unit does not jump out from the apparatus main body 100 to the surroundings, and the installation area and the occupied area are reduced.

  The above description is an image forming operation when a full-color image is formed on a sheet. A single color image is formed using any one of the image forming units 5Y, 5M, 5C, and 5K of the image forming unit 30. In some cases, a two-color or three-color image is formed. When monochrome printing is performed using the printer of this embodiment, an electrostatic latent image is formed only on the photosensitive drum 1K of the black image forming unit 5K, developed by the unit, transferred to the paper, Fixing may be performed by the fixing device 23.

  The developing device according to the embodiment will be described below. Since the developing devices 9Y, 9M, 9C, and 9K are the same in each of the image forming units 5Y, 5M, 5C, and 5K, the developing device 9Y of the image forming unit 5Y will be described. Since all the developing devices 9Y, 9M, 9C, and 9K have the same configuration, description of the subscript Y is omitted below.

FIG. 2 is a cross-sectional view illustrating a configuration of the developing device according to the embodiment, FIG. 3 is a perspective view illustrating the developing device according to the embodiment, and FIG. 4 is an enlarged cross-sectional view illustrating an operation of the developing device according to the embodiment. The developing device 9 according to the embodiment includes a developing roller 52 that applies a developer to the photosensitive drum 1 in a developing case 51, and stirring rollers 61, 62, and 63 that stir the developer in the developing case 51. The developing roller 52 is in contact with the photosensitive drum 1 to form a nip portion 58. The developing case 51 includes a seal member 57 that contacts the photosensitive drum 1 with the nip portion 58 interposed therebetween, and a protruding portion 53 that is close to the photosensitive drum 1, and a gap between the developing roller 52 and the photosensitive drum 1. Prevents toner from leaking out.

  In this example, a flow path 56 is formed below the developing roller 52. This flow path is along the axial direction of the photosensitive drum 1, is formed between the photosensitive drum 1 and the developing case 51, and has a toner receiving portion 54 below and a proximity portion 55 adjacent to the photosensitive drum 1. Surrounded by and formed. Further, the end of the flow path 56 in the axial direction of the photosensitive drum 1 (end in the front-rear direction in the drawing) is sealed with a side seal 65 shown in FIG. The side seal 65 seals the flow path 56 by being in contact with the photosensitive drum 1. Here, the proximity portion 55 disposed below the flow path 56 cannot be brought into contact with the photosensitive drum 1 on which the toner image is formed. It does not occur. The distance between the proximity portion 55 and the photosensitive drum 1 is desirably as close as possible within a range that does not affect the toner image developed on the photosensitive drum 1, and is set to 0.8 mm, for example.

  In the developing device according to this example, the flow path 56 is configured to be sealed in the vertical direction and the front-rear direction. In this example, as shown in FIG. 3, the airflow A is generated by sucking air from the opening 59 opened in the developing case 51. As a result, an air flow is generated in the flow path 56 along the longitudinal direction (axial direction) of the photosensitive drum 1. This airflow is generated by a suction device or a blower which is an airflow generating means (not shown).

  Next, toner collection processing in the developing device according to the present embodiment will be described. As shown in FIG. 4, in the developing device 9, the toner separated from the developer is scattered in the nip portion 58 (indicated by reference numeral 60 in the figure). A part of the scattered toner is generated in the developing device 9 by a suction air flow into the developing case 51 generated between the developing roller 52 and the projecting portion 53 of the developing case 51 when the developing roller 52 transports the developer and returns it to the case. Is recovered. Part of the toner that has not been collected due to inertia or airflow due to rotation of the photosensitive drum 1 flows into the flow path 56. The scattered toner is conveyed by the air flow A in the flow path 6 and collected from the opening 59. In this example, since the flow path 56 is formed integrally with the developing device 9, there is no gap and the scattered toner can be collected efficiently.

  Here, when toner lump that cannot be carried by the air flow is generated due to deterioration of toner / carrier / machine, control abnormality, etc. Since it is received at 54, it does not fall on the image. Further, since the flow path 56 does not have a portion corresponding to a conventional suction portion, and the air flow is conveyed by the air flow A in a direction different from the direction in which the toner falls, the flow path is not easily blocked. . As a result, the dropped toner can be received in the flow path, so that surrounding contamination can also be suppressed. Further, the toner accumulated in the proximity portion 55 can be easily cleaned because the flow path 56 is exposed as shown in FIG. 3 if the photosensitive drum 1 is removed during maintenance. Thereby, the flow path 56 can maintain the function of conveying scattered toner over a long period of time.

DESCRIPTION OF SYMBOLS 1 Photosensitive drum 1Y, 1M, 1C, 1K Photosensitive drum 4 Optical writing unit 5 Image forming unit 5Y, 5M, 5C, 5K Image forming unit 6 Flow path 7 Charging device 9 Developing device 9Y, 9M, 9C, 9K Developing device DESCRIPTION OF SYMBOLS 10 Intermediate transfer belt 11, 12, 13 Roller 14 Transfer roller 15 Belt cleaning device 16 Secondary transfer roller 17 Cleaning device 20 Paper feed cassette 22 Registration roller pair 23 Fixing device 24 Discharge roller 30 Image forming unit 31 Toner bottles 31Y, 31M, 31C, 31K Toner bottle 40 Scanner 45 Waste toner collection container 51 Developing case 52 Developing roller 53 Overhang portion 54 Toner receiving portion 55 Proximity portion 56 Channel 57 Seal member 58 Nip portion 59 Opening portions 61, 62, 63 Stir roller 65 Side Seal 100 Device body

JP 2002-268377 A

Claims (6)

A developer carrying member for carrying a developer on the surface and developing the latent image on the surface of the latent image carrier disposed at a position facing the latent image carrier; a developer carrying member for carrying the developer; In a developing device comprising the developer, a developer carrier, and a developer container that holds the developer transport member therein,
Extending along the axial direction of the latent image carrier between the developer container and the latent image carrier, and forming a flow path through which airflow along the extending direction can flow .
A protruding portion that prevents the developer from leaking from between the latent image carrier and the developer carrier is provided in a portion that forms the flow path, and the developer is stored below the protruding portion. A proximity portion to be held is provided close to the latent image carrier,
A developing device. The pre SL channel, while arranged in the direction of rotation downstream of the portion facing the developer carrying member wherein the latent image bearing member, below the nip the developer carrying member and said latent image bearing member to form the developing device according to claim 1, characterized in that provided. 3. The cross-sectional bag shape according to claim 1, wherein a portion of the wall surface of the developer container forming the flow path has a cross-sectional bag shape including a toner receiving portion at a lower portion and an opening portion at an upper portion . Development device. Characterized in that the opposite ends in the axial direction of the latent image bearing member before Symbol passage sealed with a sealing material and the sealing material in contact with the latent image bearing member to seal both ends of the channel The developing device according to any one of claims 1 to 3.   The developing device according to claim 1, further comprising an airflow generation unit configured to generate an airflow in the flow path. An image forming apparatus comprising the developing device according to any one of claims 1 to 5.