JP2007304453A - Developing device, process cartridge, image forming apparatus, and image forming method using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a developing device capable of forming a high quality image by removing the adverse effect of foreign matter in the developing device, and to provide a process cartridge, an image forming apparatus, and an image forming method using this. <P>SOLUTION: The developing device having a toner storage section includes: a partition 20 that divides the toner storage section into an upstream toner storage part and a downstream toner storage part; a first toner path 15 along which toner moves from the upstream toner storage part 10 to the downstream toner storage part 11; a second toner path 16 along which toner moves from the downstream toner storage part 11 to the upstream toner storage part 10; a filter 17 disposed in the first toner path 15; and a developing roller 5 disposed in the downstream toner storage part 11 and used in order that toner supplied from the upstream toner storage part 10 via the first toner path 15 is supplied to an image forming surface of an image carrier. The effective diameter of the filter 17 disposed in the first toner path 15 is made smaller than the effective diameter of the second toner path 16. This developing device is incorporated in the process cartridge and image forming apparatus. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

The present invention relates to a developing device applied to an electrophotographic image forming apparatus such as a copying machine, a printer, and a facsimile, a process cartridge, an image forming apparatus provided with these, and an image forming method using the same.

In an electrophotographic image forming apparatus, toner is supplied from a toner container to a developing roller during an image forming operation. In order to stably supply toner to the developing roller, the toner container includes a supply roller, a conveying screw, A rotating body such as a transport paddle is provided. The rotating body rotates at a high speed, and there is a problem that foreign matter is likely to be generated due to scraping or the like in the toner containing portion, particularly in the vicinity of the developing roller. That is, since the supply roller normally rotates in contact with the developing roller, when an image is formed over a long period of time, the supply roller may be damaged and the surface of the supply roller may be scraped. In addition, a seal member is usually provided at both ends of the developing roller to prevent the toner from leaking to the outside. It may become.
If these foreign matters generated near the developing roller stay, for example, stay in the developing roller portion, they may be caught between the developing roller and the developing blade, causing serious image defects such as vertical stripes. In order to solve this problem, various ideas have been conventionally made.

For example, Patent Document 1 discloses a developing device that prevents the occurrence of defective printing by preventing the occurrence of defective printing by preventing toner from being deteriorated or foreign matter caught in a developing blade by forcibly circulating toner. ) A toner carrier disposed rotatably; (b) a first toner supply member rotatably disposed in contact with the toner carrier; and (c) the toner carrier and first toner. A developing device including a guide member that forms a toner flow toward a valley region formed between the toner supply member and the toner supply member is disclosed.
Further, in Patent Document 2, even if foreign matter enters the developing device or toner aggregate is formed in the developing device, the foreign matter or toner aggregate is prevented from being conveyed again into the developing device. The developing device has been developed for the purpose of providing a developing device, and is provided with an opening provided at a portion facing the latent image carrier and a part of the opening exposed from the opening. A developer having a developer carrier, a developer containing portion configured to communicate with the inside of the developer, a developer containing portion for containing the developer to be supplied to the developer, and a developer in the developer containing portion. In a developing device having a supply transport member that is transported and supplied to a developing device, and a recovery transport member that transports and collects excess developer that has not contributed to development to a developer storage unit, a predetermined particle size is provided in the developer storage unit. Development with a filter that does not pass substances larger than the diameter Location is disclosed.

Furthermore, Patent Document 3 aims to eliminate development unevenness and high development density by obtaining good agitation without impairing the transportability of the two-component developer in a vertical developing device. An apparatus that has been developed, has an upper conveyance path and a lower conveyance path that are conducted through first and second supply ports, and is configured to transfer a two-component developer composed of toner and a carrier to the upper conveyance path and the lower conveyance path. A housing that can be circulated between conveyance paths, and a first supply port that is provided in the lower conveyance path, stirs and conveys the two-component developer in a first direction, and is located downstream in the first direction. A lower conveying means for supplying to the upper conveying path and the two-component developer provided on the upper conveying path and supplied from the first supply port in a second direction opposite to the first direction. Agitating and conveying, from the second supply port located downstream in the second direction, An upper conveying unit that drops and supplies to the conveying path; a developing unit that magnetically conveys the two-component developer supplied from the upper conveying unit and applies the toner to the electrostatic latent image holding unit; There is disclosed a developing device including a developer diffusing unit that diffuses the two-component developer attached to a supply port and dropped and supplied from the upper conveying path to the lower conveying path.

JP 2004-093924 A JP 07-168433 A JP-A-11-030913

However, none of the above prior arts can completely eliminate the influence of the foreign matter generated in the vicinity of the developing roller, and the developing device, the process cartridge, and the image that can reliably avoid image defects caused by the foreign matter. Development of a forming device has been desired.
The present invention has been made in view of the above-described problems of the prior art. The problem is that the foreign matter generated in the vicinity of the developing roller is circulated together with the toner, and the foreign matter is passed through the flow path for supplying the toner to the developing roller. It is an object of the present invention to provide a developing device, a process cartridge, an image forming apparatus, and an image forming method using the same, which can reliably eliminate the influence of foreign matter by installing a non-filter.

  In order to achieve the above object, a developing device according to the present invention includes a toner container, a partition separating the toner container into an upstream side and a downstream side, and a toner from the upstream toner container to the downstream toner container. A first toner channel through which the toner moves, a second toner channel through which toner moves from the downstream toner container to the upstream toner container, a filter provided in the first toner channel, and the downstream A developing roller that is provided in the side toner container and supplies toner supplied from the upstream toner container through the first toner channel to the image forming surface of the image carrier. The effective diameter of the filter provided in the second toner flow path is smaller than the effective diameter of the second toner flow path.

In this case, it is preferable that the upstream toner container is located above the downstream toner container.
The downstream toner storage unit and / or the upstream toner storage unit may be provided with a rotating body. Examples of the rotating body include a supply roller, a transport screw, a transport paddle, a stirring screw, and a stirring roller. Can be mentioned.
Furthermore, a seal member is provided at an end of the developing roller or the rotating body,
The first toner channel is provided at the center of the partition, and the second toner channel is provided at a position facing the both ends of the developing roller or the rotating body in the longitudinal direction of the partition. be able to.
Furthermore, a movable member that contacts the filter may be provided.

The process cartridge of the present invention is integrally formed with an image carrier and a developing device that visualizes an electrostatic latent image formed on the image carrier, and is detachable from the image forming apparatus main body. In the process cartridge, the developing device is any one of the developing devices described above.
The image forming apparatus of the present invention includes an image carrier, a charging device that uniformly charges the surface of the image carrier, and a charged surface of the image carrier that is irradiated with light based on image information. An exposure device that forms an electrostatic latent image; a developing device that visualizes the electrostatic latent image; a transfer device that transfers the visible image to a recording medium or an intermediate transfer member; and an image carrier after transfer An image forming apparatus having a cleaning device that collects toner remaining in the image forming apparatus includes any one of the developing devices described above or the process cartridge as the developing device.

Furthermore, the image forming method of the present invention can be obtained by uniformly charging the image forming surface of the image carrier with a charging device and then exposing the image carrier based on the image information to form an electrostatic latent image. In the image forming method using the image forming apparatus in which the electrostatic latent image is visualized by the developing device, the visible image is transferred to the transfer device, and the transferred image is fixed by the fixing device. The image forming apparatus is used.
In this case, it is preferable to use a one-component toner as a developer.

According to the developing device of the present invention, the foreign matter generated in the downstream toner container is moved to the upstream toner container through the second toner channel, and is introduced into the downstream toner container through the first toner channel. At this time, since it can be captured by a filter, it is possible to eliminate the influence of the foreign matter and form a good image.
According to the process cartridge of the present invention, maintenance such as replacement or repair of the developing device can be easily performed.
According to the image forming apparatus of the present invention, it is possible to stably form a high-quality image without being affected by the foreign matter generated in the developing device, particularly in the downstream toner container.
According to the image forming method of the present invention, it is possible to eliminate the influence of foreign matter generated in the developing device, particularly in the downstream toner container, thereby stably forming a high-quality image free from image quality defects.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.
FIG. 1 is an explanatory view showing a configuration of a developing device according to an embodiment of the present invention, and FIG.
In FIG. 1, the toner storage portion of the developing device 3 is divided into an upstream toner storage portion 10 and a downstream toner storage portion 11 by a partition wall 20, and the upstream toner storage portion 10 of the downstream toner storage portion 11. It is arranged above. In other words, the downstream toner storage unit 11 is positioned below the upstream toner storage unit 10 in the vertical direction. Since the downstream toner container 11 is positioned below the upstream toner container 10 in the vertical direction, powder pressure is applied to the toner flowing into the downstream toner container 11 from the upstream toner container 10, and the toner is filtered by the filter 17. Easier to pass through.

In the partition wall 20, the first toner flow path 15 in which the toner moves from the upstream toner container 10 to the downstream toner container 11, and the first toner flow in which the toner moves from the downstream toner container 11 to the upstream toner container 10. Two toner channels 16 are provided. A filter 17 is fitted and disposed in the first toner flow path 15, and the effective diameter of the filter 17 is selected to be smaller than the effective diameter of the second toner flow path 16.
The downstream toner storage unit 11 is provided with a developing roller 5, a supply roller 9, and a developing blade 8 disposed so that the front end of the developing roller 5 is in contact with the surface of the developing roller 5. The supply roller 9 supplies toner to the surface of the developing roller 5, and the developing blade 8 regulates the amount of toner that adheres to the surface of the developing roller 5.
Rotating bodies 13 and 14 are provided in the upstream toner container 10 and the downstream toner container 11, respectively. The rotating bodies 13 and 14 are conveyance members such as a supply roller, a conveyance screw, a conveyance paddle, a stirring screw, and a stirring roller for smoothing the circulation of toner, for example. The rotators 13 and 14 are arranged such that a part thereof abuts against the filter 17 fitted in the first toner flow path 15 of the partition wall 20.

In FIG. 2, seal members 18 are installed at both ends of the developing roller 5 and the supply roller 9 of the developing device 3 in order to prevent toner leakage to the outside. The first toner channel 15 is formed at a substantially central portion of the partition wall 20 in the figure, and a filter 17 is fitted in the first toner channel 15. Rotating bodies 13 and 14 are respectively arranged above and below the filter 17 so that a part thereof is in contact with the filter 17. The filter 17 is vibrated by the rotation of the rotating body 13 or 14 to prevent clogging due to clogging of foreign matter. A total of two second toner flow paths 16 are provided, one at each of the partition walls 20 at opposite positions in the longitudinal direction of the developing roller 5 and the supply roller 9.

The operation of the developing device having the above configuration will be described below.
The toner accommodated in the upstream toner accommodating portion 10 flows into the downstream toner accommodating portion 11 through the first toner channel 15 provided in the substantially central portion of the partition wall 20 as indicated by an arrow A in FIG. To do. The toner that has flowed into the downstream toner container 11 is supplied to the developing roller 5 by the supply roller 9. The toner supplied onto the developing roller 5 is regulated by the developing blade 8, and a toner thin film is formed on the surface of the developing roller 5. The thin film toner formed on the developing roller 5 is supplied to a photoconductor as an image carrier (not shown), and the electrostatic latent image is developed to form a toner image.
As shown by an arrow B in FIG. 1, the toner that has not been consumed by the developing roller 5 flows again into the upstream toner accommodating portion 10 via the second toner flow path 16, for example, newly introduced new toner. At the same time, the toner flows again into the downstream toner container 11 through the first toner channel 15. A filter 17 is disposed in the first toner flow path 15, and for example, foreign matter that occurs in the downstream toner storage portion 11 and flows into the upstream toner storage portion 10 along with the toner circulation flow is captured. Is done. That is, as shown in FIG. 2, a toner circulation flow as shown by an arrow E is formed by the action of the first toner flow path 15 and the two second toner flow paths 16 provided in the partition wall 20. . At this time, since the effective diameter of the filter 17 is selected to be smaller than the effective diameter of the second toner flow path 16, for example, foreign matter generated in the vicinity of the developing roller 5 or the supply roller 9 in the downstream toner containing portion 11. Circulates in the toner container along with the toner circulation flow, and is captured and separated by the filter 17.

According to this embodiment, the toner container is partitioned into the upstream toner container 10 and the downstream toner container 11 by the partition wall 20, and the first toner flow path 15 including the filter 17 in the partition wall 20 and the second toner channel 15 are provided. By providing the toner flow path 16, the toner flows from the upstream toner storage section 10 through the first toner flow path 15 to the downstream toner storage section 11 and from the downstream toner storage section 11 through the second toner flow path 16. A circulation flow of toner flowing into the upstream toner storage unit 10 is formed. For example, foreign matter generated in the downstream toner storage unit 11 flows into the upstream toner storage unit 10 along with the toner circulation flow, and the first toner It is captured by the filter 17 when it is introduced again into the downstream toner containing portion 11 through the flow path 15. In this way, the foreign matter that has once flowed into the upstream toner containing portion 10 can be prevented from flowing into the downstream toner containing portion 11, so that the adhering of foreign matters to the developing roller 5, developing blade 8, etc. can be avoided. Thus, a good image can be stably formed over a long period of time.

In the developing device having a vertical structure as shown in FIG. 1, the toner easily passes through the filter 17 due to the action of gravity, but the toner powder is applied to the developing roller 5 and the supply roller 9 provided in the downstream toner storage unit. The load due to pressure is likely to be applied, and there is a characteristic that foreign matter due to scraping of a part of the roller or stuck toner is likely to occur. However, in such a vertical development device, the influence of foreign matter is avoided. The effect is more prominently expressed.
Further, in the developing device in which the seal member is provided around the rotating member, if the rotating body continues to rotate for a long time and the rotating body continues to rotate, the sealing member in contact with the rotating body rotating at high speed is roughened. Foreign matter may be generated due to scraping of the surface and / or a lump of toner formed between the seal member and each rotary member. However, in this embodiment, since the toner circulation path is formed as indicated by the arrow E, for example, foreign matter generated in the downstream toner storage unit 11 can be quickly moved to the upstream toner storage unit 10. When this is introduced again into the downstream toner accommodating portion 11, it can be captured by the filter 17, so that the influence of foreign matter can be minimized.

Further, according to the present embodiment, the rotating members 13 and 14 are provided as movable members that come into contact with the filter 17 provided in the first toner flow path 15, thereby preventing the filter 17 from being clogged. Can be maintained well.
In the present embodiment, it is preferable to provide a toner conveying screw as a rotator in the upstream toner container 10. As a result, toner transportability can be improved. In addition, a toner conveying screw can be provided in the downstream toner accommodating portion 11, thereby improving the conveying ability of foreign matters together with the toner.
In this embodiment, it is preferable to use a one-component toner as the developing toner. Thereby, the effective diameter of the filter can be set without considering the influence of the carrier.

FIG. 3 is a schematic configuration diagram of a process cartridge according to the embodiment of the present invention. In FIG. 3, this process cartridge 1 is an image forming apparatus in which a photosensitive member 2 as an image carrier, a cleaning device having a cleaning blade 4 for cleaning the surface of the photosensitive member 2, and a developing device 3 are integrated. It is formed detachably on the main body.
The toner container of the developing device 3 is divided into an upstream toner container 10 and a downstream toner container 11 by a partition wall 20. The partition wall 20 is provided with a first toner flow path 15 including a filter 17. As the second toner flow path, a residual toner collection path 19 is provided for circulating the toner scraped off from the surface of the photoreceptor 2 by the cleaning blade 4 to the upstream toner storage unit 10. The effective diameter of the filter 17 provided in the first toner flow path 15 is selected to be smaller than the effective diameter of the remaining toner collection path 19.

In the process cartridge having such a configuration, the toner in the upstream toner containing portion 10 flows into the downstream toner containing portion 11 as indicated by an arrow C through the first toner flow path 15. The toner that flows into the toner container 11 on the downstream side and is supplied to the surface of the developing roller 5 by the supply roller 9 visualizes the electrostatic latent image in the print area on the photoreceptor 2 and is not shown as a toner image. For example, it is transferred to an intermediate transfer member. The untransferred residual toner remaining without being transferred is scraped off by the cleaning blade 4 and returned to the upstream toner accommodating portion 10 again via the residual toner collecting path 19 as indicated by an arrow D.

According to the present embodiment, even if foreign matter generated in the downstream toner container passes through the developing roller 5 and the photosensitive member 2 and is collected by being mixed with the remaining toner, the filter 17 provided in the first toner flow path 15 is used. Therefore, the toner does not flow again into the downstream toner container 11 and cause image defects. Therefore, a good image forming operation can be performed continuously and stably.

FIG. 4 is a diagram showing a schematic configuration of the image forming apparatus according to the embodiment of the present invention.
4, the image forming apparatus 100 is an image forming apparatus including the process cartridge of FIG. In the drawing of the image forming apparatus 100, process cartridges 1 (a, b, c, d) corresponding to yellow, cyan, magenta, and black toners are detachably arranged at the approximate center. An exposure device 103 is arranged above the process cartridge row, and this exposure device 103 is arranged on each photosensitive member 2 (a, b, c, d) of the process cartridge 1 (a, b, c, d). For example, an electrostatic latent image is formed by irradiating a laser beam.
An intermediate transfer member 101 is provided below the process cartridge row, and the intermediate transfer member 101 includes a photosensitive member 2 (a, b, c, d) of each process cartridge 1 (a, b, c, d). ) Each color toner image formed thereon is sequentially transferred and laminated to form a color image. A paper feed tray 104 is disposed below the intermediate transfer member 101, and the paper feed tray 104 accommodates recording paper as a recording medium. A fixing device 110 is disposed above the end of the intermediate transfer member 101 so as to be adjacent to the process cartridge row. The fixing device 110 forms a color image formed on the intermediate transfer member 101 and transferred onto a recording sheet. Fix on the recording paper.

Hereinafter, the operation of the image forming apparatus having such a configuration will be described in detail.
When starting the image forming operation, first, a start button (not shown) is pressed, and the static elimination lamp 7 is applied to the photosensitive member 2 (a, b, c, d) of the process cartridge 1 (a, b, c, d). Then, for example, the surface potential is averaged to the reference potential by irradiating with static elimination light. Next, the charging roller 6 (a, b, c, d) is brought into contact with the surface of the photoconductor 2 (a, b, c, d), and a high voltage is applied to the photoconductor 2 (a, b, c). , D) are uniformly charged to a predetermined potential.
Next, the exposure device 103 exposes the charged surface of the photoreceptor 2 (a, b, c, d) by irradiating, for example, a laser beam based on the image information, thereby exposing the photoreceptor 2 (a, b, c). D) An electrostatic latent image is formed on the surface. The photosensitive member 2 (a, b, c, d) on which the electrostatic latent image is formed is rotated and moved to a position facing the developing device 3 (a, b, c, d), and the developing device 3 (a , B, c, d) and the potential difference between the latent image portion, toner is attached to the latent image portion, and the electrostatic latent image is visualized. The obtained toner image as a visible image is transferred to the intermediate transfer member 101 by the potential difference and pressure between the nips of the photosensitive member 2 (a, b, c, d) and the intermediate transfer member 101, and laminated to form a color image. Form.

On the other hand, the transfer paper held on the paper supply tray 104 is conveyed to the registration roller pair 107 by the paper supply roller 105, and this registration roller pair 107 is placed at the position of the secondary transfer roller 109 between the leading edge of the transfer paper and the intermediate portion. The color image formed on the transfer body 101 is adjusted so as to coincide with the leading end of the color image, and the color image is transferred onto the transfer paper. Thereafter, the transfer sheet is conveyed between the rollers of the fixing device 110 and fixed to the transfer sheet by heat and pressure, and discharged onto a discharge tray 106 outside the apparatus. After the image transfer, the waste toner that is not transferred and remains on the photosensitive member 2 (a, b, c, d) is scraped off by the cleaning blade 4 (a, b, c, d). a, b, c, d) Prepare for the next image forming step with almost no toner remaining on the surface.

According to the present embodiment, by applying the process cartridge of FIG. 3 described above, foreign matter generated in the toner container of the developing device can be captured and separated by the filter, so that the influence is minimized, A good image without image defects can be stably output over a long period of time.
In this embodiment, it is preferable to apply a one-component toner as a developer. This eliminates the need to consider the carrier in the design stage of the filter 17 and facilitates the design.

1 is a diagram illustrating a schematic configuration of a developing device according to the present invention. It is a principal part expanded sectional view of FIG. It is a figure which shows schematic structure of the process cartridge which concerns on this invention. 1 is a diagram illustrating a schematic configuration of an image forming apparatus according to the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Process cartridge 2 Photoconductor 3 Developing apparatus 4 Cleaning blade 5 Developing roller 6 Charging roller 8 Developing blade 9 Supplying roller 10 Upstream toner storage unit 11 Downstream toner storage unit 13 Rotating body 14 Rotating body 15 First toner flow path 16 2 Toner channel 17 Filter 18 Seal member 19 Residual toner recovery channel
20 Bulkhead 100 Image forming apparatus 101 Intermediate transfer member 103 Exposure device 104 Paper feed tray 105 Paper feed roller 106 Paper discharge tray 107 Registration roller pair 109 Secondary transfer roller 110 Fixing device

Claims (10)

A toner container;
A partition that separates the toner container into an upstream side and a downstream side;
A first toner flow path through which toner moves from the upstream toner container to the downstream toner container;
A second toner flow path through which toner moves from the downstream toner container to the upstream toner container;
A filter provided in the first toner flow path;
A developing roller that is provided in the downstream toner container and supplies toner supplied from the upstream toner container through the first toner channel to the image forming surface of the image carrier;
Have
A developing device, wherein an effective diameter of a filter provided in the first toner channel is made smaller than an effective diameter of the second toner channel. The developing device according to claim 1,
The developing device according to claim 1, wherein the upstream toner storage unit is located above the downstream toner storage unit. The developing device according to claim 1 or 2,
The developing device according to claim 1, wherein a rotating body is provided in the upstream toner container and / or the downstream toner container. The developing device according to claim 3,
The developing device, wherein the rotating body is a supply roller, a transport screw, a transport paddle, a stirring screw, or a stirring roller. The developing device according to claim 4,
A seal member is provided at an end of the developing roller or the rotating body;
The first toner flow path is provided at a central portion of the partition wall, and the second toner flow path is provided at a position facing the both ends of the development roller or the rotating body in the longitudinal direction of the partition wall. A developing device. In the developing device according to any one of claims 1 to 5,
A developing device comprising a movable member that contacts the filter. An image carrier;
In a process cartridge formed integrally with a developing device that visualizes the electrostatic latent image formed on the image carrier, and is detachable from the image forming apparatus main body,
The process cartridge according to claim 1, wherein the developing device is the developing device according to claim 1. An image carrier;
A charging device for uniformly charging the surface of the image carrier;
An exposure apparatus that forms an electrostatic latent image by irradiating light on the charging surface of the image carrier based on image information;
A developing device for visualizing the electrostatic latent image;
A transfer device for transferring the visible image to a recording medium or an intermediate transfer member;
A cleaning device for collecting toner remaining on the image carrier after transfer;
In an image forming apparatus having
An image forming apparatus comprising the developing device according to claim 1 or the process cartridge according to claim 7 as the developing device. After the image forming surface of the image carrier is uniformly charged by a charging device, it is exposed based on image information by an exposure device to form an electrostatic latent image, and the resulting electrostatic latent image can be developed by a developing device. In an image forming method using an image forming apparatus that visualizes, transfers a visible image to a transfer device, and fixes the transferred image by a fixing device.
9. An image forming method using the image forming apparatus according to claim 8 as the image forming apparatus. 10. The image forming method according to claim 9, wherein one-component toner is used as a developer.

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