JP4105480B2 - Toner transport device - Google Patents

Description

【００１８】
トナー粒径と画質との関係を以下の表２に示す。体積平均粒径を５〜１０μｍとし、かつその粒径５μｍ以下を６０〜８０個数％にすることで、高精細化・高解像化が可能になったことがわかる。
【表２】

解像度は、縦線、横線が、それぞれ１ｍｍあたり、２．０、２．２、２．５、２．８、３．２、３．６、４．０、４．５、５．０、５．６、６．３、７．１本の線が等間隔に並んでいる線画像に対して、複写画像が線間をどこまで忠実に再現できるかを評価した。
【００１９】
図５のトナー搬送装置で、エアーポンプ７１のＯＦＦタイミングとジョイント部９０のトナー溜まりとの関係を評価した。エアーポンプ７１のＯＦＦ遅延時間は、オーガ（トナー搬送スクリュ５１）のＯＦＦタイミングを基準（０ｓ）とした。
【表３】

エアーポンプ７１のＯＦＦタイミングを遅延させることで、ジョイント部９０のトナー溜まり量が減少した。
【００２０】
上記トナー搬送装置を搭載することで、微粉含有トナーを用いる画像形成装置のトナー搬送を安定させ、高画質化を達成することができる。
【００２１】
【発明の効果】
以上説明したように、本発明によれば、トナー搬送経路およびトナーリサイクル経路一部にエアーポンプまたはモーノポンプによるエアー搬送機構を用いることで、トナーリサイクルシステムと高画質化を両立させたトナー搬送装置を提供することができる。
また、トナー搬送経路およびトナーリサイクル経路の最も現像ホッパよりにエアー搬送機構を設けることで、オーガを使用する構成であっても副作用が少なく高画質化が可能なトナー搬送装置を提供することができる。
さらに、現像ホッパのエアー抜きを目的としたエアー循環経路を設けることで、現像ホッパ部におけるトナー飛散や圧抜きフィルタの目詰まりを防止したトナー搬送装置を提供することができる。
さらに、搬送経路のジョイント部材を設け、各搬送経路の連結位置を規定することで、万が一トナー塊が形成されても、エアーポンプに吸引されないよう分級することが可能なトナー搬送装置を提供することができる。
さらに、エアーポンプの駆動ＯＦＦタイミングをオーガ駆動ＯＦＦから遅延させることで、ジョイント下部のトナー溜まりを減少させ、安定したトナー搬送システムのトナー搬送装置を提供することができる。
さらに、本発明によれば、上記トナー搬送装置を用いることで、トナーリサイクルシステムと高画質化を両立させた画像形成装置を提供することができる。
【図面の簡単な説明】
【図１】本発明のトナー搬送装置を示す構成図である。
【図２】モーノポンプの構成を示す図である。
【図３】オーガを用いた場合の本発明のトナー搬送装置の構成を示す図である。
【図４】現像ホッパにエアー循環用チューブを設けた構成を示す図である。
【図５】図４における搬送チューブの構成を示す図である。
【図６】ジョイント部内でのトナー溜まりを示す図であり、（ａ）は従来図、（ｂ）は本発明である。
【図７】従来のトナー搬送装置の構成を示す図である。
【図８】従来のエアー搬送機構の一例を示す図である。
【符号の説明】
１０ 感光体ユニット
１１ 感光体
１２ クリーニングブレード
１３ クリーニングブラシ
１４ 廃トナー搬送スクリュ
２０ 現像ユニット
２１ トナー供給部
２２ 現像ユニット本体
２３ 現像ホッパ
２４ 圧抜きフィルタ
３０ 転写ユニット
３１ 転写ベルト
３２ クリーニングブレード
３３ 駆動ローラ
３４ 従動ローラ
３５ ケーシング
４０ トナーボトルユニット
４１ トナーボトル
４２ トナーボトル駆動装置
４３ ケーシング
５０ トナー供給搬送経路
５１ トナー搬送スクリュ
５２ トナー搬送パイプ
５３ 搬送スクリュ駆動装置
６０ トナーリサイクル経路
６１ リサイクルトナー搬送スクリュ
６２ リサイクルトナー搬送パイプ
７０ トナーポンプ装置
７１ エアーポンプ（駆動モータ含む）
７２ 上流側チューブ
７３ 下流側チューブ
７４ エアー循環用チューブ
８０ モーノポンプ部
８１ ロータ
８２ ステータ
８３ モーノポンプ用エアーポンプ（チューブ、駆動モータ含む）
８４ 搬送チューブ
８５ ケーシング
９０ ジョイント部[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a toner conveying apparatus that conveys toner using an air conveying mechanism according to an image forming apparatus such as a copying machine or a printer.
[0002]
[Prior art]
In recent years, there has been a strong demand for higher definition and higher resolution of copied or printed images.
In order to obtain such high-definition and high-resolution images, Japanese Patent Application Laid-Open Nos. 1-112253, 2-284158, and 7-295283 disclose toner particles having a small average particle diameter and 5 μm or less. Developers that define the content and distribution thereof have been proposed. Here, toner particles of 5 μm or less are essential components for forming a high-definition, high-resolution image. When toner of this particle size is smoothly supplied during development of a latent image, it is faithful to the latent image. That is, an image with excellent reproducibility that does not protrude from the latent image is obtained.
On the other hand, the edge effect phenomenon in which the density in the central portion of the image is lighter than that in the edge portion appears more conspicuously with toner particles of 5 μm or less. For this, the number% of toner particles is defined. , Trying to solve this problem.
[0003]
However, the toner has the following problems.
As the fine powder content of the toner increases, the granularity decreases and dot reproducibility is improved. In particular, in a digital machine, halftone reproducibility is improved. On the other hand, since it contains a lot of fine particles, it easily aggregates. For example, toner aggregation easily occurs in a toner transport path using an auger transported by a transport screw. The toner aggregation nuclei deteriorate the firefly image and the black solid filling. Therefore, it is necessary to pay close attention to the toner conveying means in order to improve the image quality using the toner.
In recent years, the number of machines equipped with a toner recycling system is increasing. However, recycled toner tends to aggregate more easily than new toner due to additives being buried, and so on. Since aggregation may lead to a toner lump, it is very difficult to achieve compatibility between the toner and the toner recycling system.
[0004]
FIG. 7 is a diagram for explaining a general toner conveying apparatus including a toner conveying path between a toner bottle and a developing hopper, and a toner recycling path. FIG. 8 is a diagram illustrating an example of a general air transport mechanism.
The toner supplied from the toner bottle 41 to the casing 43 by driving the toner bottle driving device 42 is supplied to the toner supply unit 51 located upstream of the developing hopper 23 via the conveying pipe 52 by the toner conveying screw 51 and the conveying screw driving device 53. 21 is replenished.
In the toner recycling system, untransferred toner scraped from the photoreceptor 11 by the cleaning blade 12 and the cleaning brush 13 passes through the recycled toner transport pipe 62 by the waste toner transport screw 14 and the recycled toner transport screw 61. The supply unit 21 is replenished.
[0005]
In addition, when an air transport mechanism is used for transporting toner to the developing hopper 23, it is common to use an air venting filter so that the toner does not scatter in the developing hopper 23 portion. It is easy to cause toner leakage from the toner and clogging of the filter. Further, the toner soul described above causes clogging of the air pump and the tube, which is a fatal problem.
[0006]
[Problems to be solved by the invention]
Therefore, when using the above toner, equipped with a toner recycling system, and using an air transport mechanism with an air pump, it has a mechanism that can suppress abnormal temperature rise in the machine and can classify if a toner lump is formed. It is important.
In view of the above problems, the present invention provides a toner conveying apparatus that conveys the fine powder-containing toner and that uses an air conveying mechanism and that can achieve both a toner recycling system and high image quality. With the goal.
Further, it is possible to prevent toner scattering in a developing hopper, clogging of a pressure release filter, air pump clogging of a toner soul, and the like, and to provide a toner conveying device of a stable toner conveying system even with a conveying mechanism using an auger. With the goal.
Another object of the present invention is to provide an image forming apparatus using these toner conveying devices.
[0007]
[Means for Solving the Problems]
In order to solve the above problems, a toner conveying device of the present invention includes a toner bottle, a casing to which toner is supplied from the toner bottle, and a toner conveying device for supplying toner from the casing to a developing hopper via a joint portion. The toner transport device includes a toner transport path for transporting toner from the casing to the joint by an auger, and transporting toner from the joint to the development hopper by an air pump, and from the development hopper to the joint. An air circulation path for sending air, wherein the connection position of the air pump and the joint part is above the connection position of the joint part and the auger, and the air circulation path The connection position with the joint part is the connection between the joint part and the auger. Than forming position, characterized in that at the bottom.
The toner conveying device of the present invention is further characterized in that the drive OFF timing of the air pump is delayed from the drive OFF timing of the auger .
[0008]
The image forming apparatus according to the present invention includes at least the photosensitive member, a developing unit that forms a toner image from the latent image on the photosensitive member, and a toner conveying device that conveys the toner to the developing unit. The conveying device is a toner conveying device according to claim 1 or 2.
[0009]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
In the toner conveying device of the present invention, a fine powder-containing toner having a volume average particle diameter of 5 to 10 μm and a particle diameter of 5 μm or less of 60 to 80% by number is used as the toner.
The toner is composed of a resin component and a colorant, and a wax component and inorganic fine particles can be added. Also, the production method is not particularly limited, and either a pulverization method or a polymerization method can be used.
[0010]
Any conventionally known resin can be used as the resin component. For example, styrene, poly-α-still styrene, styrene-chlorostyrene copolymer, styrene-propylene copolymer, styrene-butadiene copolymer, styrene-vinyl chloride copolymer, styrene-vinyl acetate copolymer, styrene -Styrene such as maleic acid copolymer, styrene-acrylic acid ester copolymer, styrene-methacrylic acid ester copolymer, styrene-alpha-methyl acrylate copolymer, styrene-acrylonitrile-acrylic acid ester copolymer Resin (monopolymer or copolymer containing styrene or styrene-substituted product), polyester resin, epoxy resin, vinyl chloride resin, rosin-modified maleic acid resin, phenol resin, polyethylene resin, polyester resin, polypropylene resin, petroleum resin, Polyurethane resin, ketone tree Examples thereof include fats, ethylene-ethyl acrylate copolymers, xylene resins, and polyvinyl butyrate resins. Moreover, although single use is also possible, you may use 2 or more types together.
[0011]
As the colorant, conventionally known ones can be used, and for example, carbon black, lamp black, iron black, ultramarine blue, nigrosine dye, aniline blue, calco oil blue, oil black, azo oil black and the like are not particularly limited.
A conventionally well-known thing can be used as a wax component, For example, carnauba wax, rice wax, synthetic ester wax, etc. are not specifically limited.
A conventionally well-known thing can be used as an inorganic fine particle, For example, a silica, a titanium oxide fine powder, etc. are not specifically limited.
[0012]
FIG. 1 is a configuration diagram showing a toner conveying device of the present invention.
An air conveyance mechanism is used between the toner bottle 41 to the casing 43 and the developing hopper 23 and in a part between the photosensitive member cleaning unit and the developing hopper 23 in the toner recycling system mounting machine.
The air transport mechanism is configured by an air pump (including a drive motor) 71, an upstream tube 72, and a downstream tube 73. When using an air conveyance mechanism, it is preferable to provide a pressure relief filter 24 around the toner supply unit 21.
[0013]
Alternatively, a Mono pump may be used as the air transport mechanism.
FIG. 2 is a diagram showing an example when used in a part between the photosensitive member cleaning unit and the developing hopper 23.
The air transport mechanism that uses a Mono pump is composed of a recycled toner transport screw 61 that transports toner to the Mono pump section 80, a rotor 81, a stator 82, an air pump for a Mono pump (including a tube and a drive motor) 83, a transport tube 84, and a casing 85. The Although used on the toner recycling side in this figure, it can also be suitably used for an air conveyance mechanism between the toner bottle 41 and the developing hopper 23.
[0014]
Further, when an auger including a toner conveying screw 51 and a toner conveying pipe 52 is used between the toner bottle 41 and the developing hopper 23, an air pump 71 is provided on the side closest to the developing hopper 23 as shown in FIG. As a result, even in a toner conveyance device having a configuration in which an auger must be used, toner does not aggregate and stable toner conveyance can be performed.
Further, when an air conveyance mechanism is used between the toner bottle 41 and the developing hopper 23, an air circulation tube 74 is provided from the toner supply unit 21, as shown in FIG. By positively venting air in this way, it is possible to prevent toner scattering from the pressure release filter 24 and filter clogging.
[0015]
FIG. 5 is a diagram showing the configuration of the transport tube in the configuration of FIG.
The developing hopper 23, the toner bottle 41, and the air pump 71 are connected via a joint portion 90. The upstream tube 72 that transports the toner to the developing hopper 23 has a connection position at the joint portion 90 above the connection position of the toner transport pipe 52 (auger). The toner transport pipe 52 is located above the air circulation tube 74.
Therefore, the toner transported from the toner bottle 41 via the toner transport pipe 52 is pulled upward in the joint portion 90 and transported to the developing hopper 23 via the upstream tube 72. Therefore, toner lumps and carriers having a specific gravity are accumulated below the joint portion 90, and only normal toner can be classified as an air-fuel mixture above the joint portion 90.
With this configuration, even if a toner lump is generated due to an abnormal temperature rise in the machine, problems such as air pump clogging do not occur.
[0016]
However, in the configuration of FIG. 5, after the operation of the air pump 71 is turned OFF, a certain amount of normal toner that is not a toner soul accumulates below the joint portion 90. FIGS. 6A and 6B are diagrams showing toner accumulation in the joint portion 90, where FIG. 6A is a conventional view and FIG. 6B is the present invention.
Therefore, if the OFF time of the air pump 71 is delayed for 0 to 10 seconds with respect to the OFF time of the conveying screw 51, the amount of normal toner accumulated in the joint portion 90 can be reduced.
[0017]
Examples for specifically describing embodiments of the present invention will be described below.
The toner used is a toner having a volume average particle size of 5 to 10 μm and a particle size of 5 μm or less of 60 to 80% by number. Table 1 below shows the particle size distribution of the toner.
[Table 1]

[0018]
The relationship between toner particle size and image quality is shown in Table 2 below. It can be seen that high definition and high resolution can be achieved by setting the volume average particle size to 5 to 10 μm and the particle size of 5 μm or less to 60 to 80% by number.
[Table 2]

The resolution is 2.0, 2.2, 2.5, 2.8, 3.2, 3.6, 4.0, 4.5, 5.0, 5 for each vertical line and horizontal line. For a line image in which .6, 6.3, and 7.1 lines are arranged at equal intervals, it was evaluated how faithfully the copied image can be reproduced between the lines.
[0019]
The relationship between the OFF timing of the air pump 71 and the toner reservoir in the joint portion 90 was evaluated using the toner conveying device shown in FIG. The OFF delay time of the air pump 71 is based on the OFF timing of the auger (toner conveying screw 51) as a reference (0 s).
[Table 3]

By delaying the OFF timing of the air pump 71, the amount of toner accumulated in the joint portion 90 is reduced.
[0020]
By mounting the toner conveying device, it is possible to stabilize the toner conveyance of the image forming apparatus using the fine powder-containing toner and to achieve high image quality.
[0021]
【The invention's effect】
As described above , according to the present invention, a toner transport device that achieves both a toner recycling system and high image quality by using an air transport mechanism using an air pump or a mono pump in part of the toner transport path and the toner recycle path. Can be provided.
In addition, by providing an air transport mechanism that is farthest from the developing hopper in the toner transport path and toner recycling path, it is possible to provide a toner transport apparatus that can achieve high image quality with few side effects even in a configuration that uses an auger. .
Furthermore, by providing an air circulation path for the purpose of releasing the air from the developing hopper, it is possible to provide a toner conveying device that prevents toner scattering and clogging of the pressure releasing filter in the developing hopper.
Furthermore, by providing a joint member for a transport path and defining a connection position of each transport path, a toner transport device that can be classified so that even if a toner lump is formed, it is not sucked by an air pump. Can do.
Furthermore, by delaying the air pump drive OFF timing from the auger drive OFF, the toner accumulation in the lower portion of the joint can be reduced, and a stable toner transport device of the toner transport system can be provided.
Furthermore, according to the present invention, by using the toner conveying device, it is possible to provide an image forming apparatus that achieves both a toner recycling system and high image quality.
[Brief description of the drawings]
FIG. 1 is a configuration diagram illustrating a toner conveying device of the present invention.
FIG. 2 is a diagram illustrating a configuration of a MONO pump.
FIG. 3 is a diagram illustrating a configuration of a toner conveying device of the present invention when an auger is used.
FIG. 4 is a view showing a configuration in which an air circulation tube is provided in the developing hopper.
FIG. 5 is a diagram showing a configuration of a transfer tube in FIG. 4;
FIGS. 6A and 6B are diagrams illustrating toner accumulation in a joint portion, where FIG. 6A is a conventional view and FIG. 6B is the present invention.
FIG. 7 is a diagram illustrating a configuration of a conventional toner conveyance device.
FIG. 8 is a diagram illustrating an example of a conventional air conveyance mechanism.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 10 Photoconductor unit 11 Photoconductor 12 Cleaning blade 13 Cleaning brush 14 Waste toner conveyance screw 20 Development unit 21 Toner supply part 22 Development unit main body 23 Development hopper 24 Pressure release filter 30 Transfer unit 31 Transfer belt 32 Cleaning blade 33 Drive roller 34 Driven Roller 35 Casing 40 Toner bottle unit 41 Toner bottle 42 Toner bottle driving device 43 Casing 50 Toner supply transport path 51 Toner transport screw 52 Toner transport pipe 53 Transport screw drive 60 Toner recycling path 61 Recycled toner transport screw 62 Recycled toner transport pipe 70 Toner pump device 71 Air pump (including drive motor)
72 Upstream Tube 73 Downstream Tube 74 Air Circulation Tube 80 Mono Pump Unit 81 Rotor 82 Stator 83 Mono Pump Air Pump (Including Tube and Drive Motor)
84 Conveying tube 85 Casing 90 Joint part

Claims (3)

Toner bottle,
A casing to which toner is supplied from the toner bottle;
In a toner conveying device that supplies toner from the casing to a developing hopper via a joint portion,
The toner conveying device conveys toner from the casing to the joint by an auger, and conveys toner from the joint to the developing hopper by an air pump; and
An air circulation path for sending air from the developing hopper to the joint part,
The connection position of the air pump and the joint part is above the connection position of the joint part and the auger, and the connection position of the air circulation path and the joint part is the joint part and the joint part. A toner conveying device, which is located below a connecting position with an auger . The toner conveying device according to claim 1,
The toner conveying device according to claim 1, wherein the driving OFF timing of the air pump is delayed from the driving OFF timing of the auger . At least with a photoreceptor,
A developing unit for forming a toner image from the latent image on the photoreceptor;
In an image forming apparatus including a toner conveying device that conveys toner to a developing unit,
The toner conveying device is the toner conveying device according to claim 1.
An image forming apparatus .

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