JPH096139A - Developing device - Google Patents
Developing deviceInfo
- Publication number
- JPH096139A JPH096139A JP15072495A JP15072495A JPH096139A JP H096139 A JPH096139 A JP H096139A JP 15072495 A JP15072495 A JP 15072495A JP 15072495 A JP15072495 A JP 15072495A JP H096139 A JPH096139 A JP H096139A
- Authority
- JP
- Japan
- Prior art keywords
- carrier
- developer
- magnetic
- magnetic force
- collected
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Withdrawn
Links
Landscapes
- Magnetic Brush Developing In Electrophotography (AREA)
- Dry Development In Electrophotography (AREA)
Abstract
Description
【０００１】[0001]
【産業上の利用分野】本発明は静電潜像を現像して可視
化する画像形成装置、例えば複写機、レーザビームプリ
ンタ等の現像装置に関するものである。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming apparatus for developing and visualizing an electrostatic latent image, for example, a developing apparatus such as a copying machine or a laser beam printer.
【０００２】[0002]
【従来の技術】電子写真法を利用した複写機やレーザー
ビームプリンタ(LBP)では、トナーとキャリアとからな
る２成分現像剤が多用されている。２成分現像剤では、
内部に複数の磁極を配した現像剤担持体によって磁気ブ
ラシを形成し、トナーのみを潜像に付着せしめる。キャ
リアは、製造過程で粒径や、透磁率が異なるものが生
じ、粒径の小さいものや透磁率が低いものは、現像剤担
持体内の永久磁石によって保持されている力よりも記録
体上の潜像、背景部（非潜像部）に吸引される力が強い
ので、記録体上に付着する現象（以下キャリアステイッ
クと呼ぶ）が生じる。転写される際には、キャリアが付
着している部分が転写されないので、広面積像において
は白抜け、線画、文字等の場合には、脱字となって識別
不可能となる場合がある。近年LBPは、金融関係の請求
書、明細書あるいはバーコード等に利用される機会が増
えておりキャリアステイックによる脱字は重要な問題点
である。2. Description of the Related Art In a copying machine or a laser beam printer (LBP) using an electrophotographic method, a two-component developer composed of a toner and a carrier is often used. With a two-component developer,
A magnetic brush is formed by a developer bearing member having a plurality of magnetic poles arranged inside to adhere only toner to the latent image. Carriers with different particle diameters and magnetic permeability are produced in the manufacturing process, and those with small particle diameter and low magnetic permeability are more likely to cause a difference in the recording medium than the force held by the permanent magnet in the developer carrier. Since the force of attraction to the latent image and the background portion (non-latent image portion) is strong, a phenomenon of sticking to the recording medium (hereinafter referred to as carrier stick) occurs. When the image is transferred, the part to which the carrier is attached is not transferred. Therefore, in a wide area image, in the case of white spots, line drawings, characters, etc., there is a case that the character is missing and cannot be identified. In recent years, LBP has been increasingly used for financial invoices, statements, bar codes, etc., and punctuation due to carrier sticking is an important issue.
【０００３】また、非画像部においても記録体上に付着
したキャリアは転写されなければ、画質上には支障はな
いが、そのまま清掃系に移動した場合、クリーニングブ
ラシやクリーニングブレードを、また用紙上に転写され
た場合も定着の際、定着ロールをいためる等、消耗部品
の交換を早める原因となる。さらに、遠心力によってキ
ャリアが現像剤担持体から飛散したり、感光体に付着し
たキャリアが重力により機内に落下して、用紙搬送系の
部位に入りこんだ場合、その箇所をいため、用紙つまり
の原因になる。その他、飛散キャリアで機内が汚染され
た場合、メンテナンス時に取り除くための作業が必要に
なる。Further, even in the non-image area, if the carrier attached to the recording medium is not transferred, the image quality is not hindered. Even when it is transferred to, it may cause expedited replacement of consumable parts such as damaging the fixing roll during fixing. Furthermore, if the carrier scatters from the developer carrier due to centrifugal force, or if the carrier attached to the photoconductor falls into the machine due to gravity and enters the part of the paper transport system, that part is removed, causing the paper to be clogged. become. In addition, if the inside of the machine is contaminated by the scattering carrier, work is required to remove it during maintenance.
【０００４】[0004]
【発明が解決しようとする課題】このようにキャリアス
テイック、キャリア飛散による障害を防ぐことは、高画
質、高信頼性を得るのに不可欠である。そこで特開平6-
11970号公報のように、単一の磁石からなるキャリア回
収部材を現像剤担持体下部に設けるものがある。しか
し、このような構成をとる場合、現像剤担持体内部の磁
極とキャリア回収部材内の磁極間で磁気干渉を生じて、
キャリア回収部材で捕集したキャリアをうまく、搬送で
きずに、つまり等の不具合を生じるという問題があっ
た。In order to obtain high image quality and high reliability, it is essential to prevent obstacles due to carrier sticking and carrier scattering. Therefore, JP-A-6-
As in Japanese Patent No. 11970, there is one in which a carrier collecting member composed of a single magnet is provided below a developer carrying member. However, when such a configuration is adopted, magnetic interference occurs between the magnetic pole inside the developer carrier and the magnetic pole inside the carrier recovery member,
There is a problem in that the carrier collected by the carrier recovery member cannot be conveyed properly, that is, problems such as clogging occur.
【０００５】[0005]
【課題を解決するための手段】本発明は、キャリア回収
部材が捕集したキャリアを、キャリア回収部材および現
像剤担持体間に生じる磁界によって搬送するものであ
り、キャリアを搬送するために現像剤担持体の磁極位
置、キャリア回収部材の外周に生じる磁力に着目したも
のである。SUMMARY OF THE INVENTION The present invention conveys a carrier collected by a carrier collecting member by a magnetic field generated between the carrier collecting member and a developer carrier, and a developer for conveying the carrier. It focuses on the magnetic pole position of the carrier and the magnetic force generated on the outer periphery of the carrier recovery member.
【０００６】[0006]
【作用】本発明によれば、キャリア回収部材から現像剤
担持体の方向に磁界が働き、現像機内に現像剤を引き込
むことができるので、つまりが生じることなく円滑に現
像剤を搬送することが可能になる。また、現像剤担持体
に設けられた極と磁気干渉を起こすことなく現像剤が搬
送される。According to the present invention, since the magnetic field acts from the carrier recovery member toward the developer carrying member and the developer can be drawn into the developing machine, the developer can be smoothly conveyed without being clogged. It will be possible. Further, the developer is transported without causing magnetic interference with the poles provided on the developer carrier.
【０００７】[0007]
【実施例】本発明を電子写真法を用いるレーザプリンタ
に適用した実施例を図１を用いて以下説明する。現像剤
収容容器１底部には、２本のスクリュー状の撹拌部材
２、３が設けられており、現像剤を撹拌、混合しながら
現像剤担持体４まで現像剤５を搬送する。現像剤担持体
４の内部には複数の磁極を持つ永久磁石６が内在されて
おり、矢印方向にスリーブ７のみ回転しながら現像剤５
を吸着、搬送し、搬送方向に設けられた規制部材８によ
って一定の高さに規制され、現像剤担持体４により感光
体９まで搬送する。感光体９上には帯電器１０のコロナ
放電により表面を帯電されたのち半導体レーザー、LED
等の光源１１により潜像が形成され、トナーのみ感光体
９に付着する。DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment in which the present invention is applied to a laser printer using electrophotography will be described below with reference to FIG. Two screw-shaped stirring members 2 and 3 are provided at the bottom of the developer container 1, and the developer 5 is conveyed to the developer carrier 4 while stirring and mixing the developers. A permanent magnet 6 having a plurality of magnetic poles is internally provided inside the developer carrying member 4, and only the sleeve 7 is rotated in the direction of the arrow while the developer 5 is being rotated.
Is adsorbed and conveyed, regulated to a constant height by a regulating member 8 provided in the conveying direction, and conveyed to the photoconductor 9 by the developer carrying member 4. The surface of the photoconductor 9 is charged by the corona discharge of the charger 10 and then the semiconductor laser, LED
A latent image is formed by the light source 11 such as the above, and only the toner adheres to the photoconductor 9.
【０００８】現像剤担持体４下部には、飛散キャリア、
感光体上に付着したキャリアを補集するためのキャリア
回収部材１２が設けられている。キャリア回収部材１２
内には現像剤担持体４同様に、永久磁石１３が固定して
内在しており、スリーブ１４のみ矢印方向に回転して、
補集したキャリアを搬送する。搬送されたキャリアは、
後述するがキャリア回収部材と現像剤担持体の極間に働
く磁力により、現像剤担持体４に吸引される。Below the developer carrying member 4, a scattering carrier,
A carrier recovery member 12 is provided for collecting carriers attached to the photoconductor. Carrier recovery member 12
Like the developer carrying member 4, a permanent magnet 13 is fixedly provided therein, and only the sleeve 14 rotates in the arrow direction,
Transport the collected carriers. The transported carrier is
As will be described later, the magnetic force acting between the carrier recovery member and the developer carrying member attracts the developer carrying member 4.
【０００９】現像がおこなわれる際、前述したように現
像剤担持体４内の永久磁石６によって保持されているキ
ャリアが、記録体上の潜像、非潜像部に吸引される力が
強くなり記録体上に付着したり、遠心力によりキャリア
が飛散する現象が生じる。この付着、飛散キャリアを回
収するキャリア回収部材１２の働きを図２を用いて詳細
に説明する。When the development is carried out, the carrier held by the permanent magnet 6 in the developer carrying member 4 is strongly attracted to the latent image and non-latent image portions on the recording member as described above. The phenomenon that the carrier adheres to the recording medium or the carrier scatters due to centrifugal force occurs. The function of the carrier collecting member 12 for collecting the adhered and scattered carriers will be described in detail with reference to FIG.
【００１０】感光体９とキャリア回収部材１２間は、一
定の間隔をもって保持されている。感光体９上に付着し
たキャリア１５は、キャリア回収部材１２の磁力によっ
て吸引される。また現像剤担持体４上から飛散したキャ
リア１６も重力により、落下する力が働くので、キャリ
ア回収部材１２の近傍で磁力により吸引される。スリー
ブ１４は、省略するが、現像機の駆動ギアを介して、間
欠的に矢印方向に回転しているので、一定量補集された
キャリア１７は、矢印方向に搬送される。現像剤担持体
４上の極１８と磁気干渉を避けるため、キャリア回収部
材の内部の永久磁石１３は単一磁石で構成されている。
この場合、外周には、永久磁石１３によって磁力１９と
ほぼ同面積で、この極とは極性が異なる磁力２０が生じ
る。現像剤担持体４のキャリア回収部材１２との対向し
た面の近傍には、キャリア回収部材の永久磁石１３とは
反対の極１８が設けられている。従って、キャリア回収
部材１２と現像剤担持体４上の極１８間には、磁界が生
じるので補集キャリアには、矢印方向の力が働き、移動
することができる。しかし、この磁力２０が大きくなる
と現像剤担持体４上の極１８と反発力が働くためキャリ
アを搬送することができず、つまりとなってキャリア回
収部材１３上に堆積する。キャリア回収部材１３上に堆
積する現像剤が増加すると感光体上に形成されたトナ−
像を掻き取る等の不具合が生じる。The photosensitive member 9 and the carrier recovery member 12 are held with a constant space. The carrier 15 attached on the photoconductor 9 is attracted by the magnetic force of the carrier recovery member 12. Further, the carrier 16 scattered from the developer carrying member 4 also has a force of dropping due to gravity, and therefore is attracted by magnetic force in the vicinity of the carrier recovery member 12. Although omitted, the sleeve 14 is intermittently rotated in the direction of the arrow via the drive gear of the developing machine, so that the carrier 17 collected by a certain amount is conveyed in the direction of the arrow. In order to avoid magnetic interference with the pole 18 on the developer carrier 4, the permanent magnet 13 inside the carrier recovery member is composed of a single magnet.
In this case, on the outer circumference, a magnetic force 20 is generated by the permanent magnet 13 which has substantially the same area as the magnetic force 19 but has a polarity different from that of this magnetic pole. A pole 18 opposite to the permanent magnet 13 of the carrier collecting member is provided in the vicinity of the surface of the developer carrying member 4 facing the carrier collecting member 12. Therefore, since a magnetic field is generated between the carrier recovery member 12 and the pole 18 on the developer carrying member 4, a force in the direction of the arrow acts on the collecting carrier, and the carrier can move. However, when the magnetic force 20 becomes large, the repulsive force acts on the pole 18 on the developer carrying member 4, so that the carrier cannot be conveyed, that is, it accumulates on the carrier collecting member 13. When the amount of the developer deposited on the carrier recovery member 13 increases, the toner formed on the photoconductor is increased.
Problems such as scraping the image occur.
【００１１】図３は、磁力２０の磁束密度とキャリア回
収部材１３上の現像剤の堆積量を表したものである。こ
のように磁力２０の磁束密度が小さくなると、堆積量が
減少することがわかり、これを１５０ガウス、好ましく
は１００ガウス以下とするのがよい。FIG. 3 shows the magnetic flux density of the magnetic force 20 and the amount of developer deposited on the carrier recovery member 13. It has been found that when the magnetic flux density of the magnetic force 20 is reduced as described above, the deposition amount is reduced, and it is preferable to set the deposition amount to 150 gauss, preferably 100 gauss or less.
【００１２】図４は、極１８の位置とキャリア回収部材
１２上の現像剤堆積量を表したもので、対向した位置を
０°として、移動方向側を−としている。極１８が対向
した位置よりも、移動方向に対して内側（−方向）にな
ると、現像機内に現像剤を引き込むことができるので、
堆積量が減少することがわかる。しかし、１５°になる
と極１８が離れるので、逆に堆積量は増える。このた
め、内側に数度から１０度くらいがのぞましい。磁力に
よって吸引できないトナーや紙粉は、スクレーパ２１に
よって、かきおとされる。このように、キャリア回収部
材の永久磁石を単一にすることによって、補集キャリア
の搬送を安定に行うことが出来ると共に、製造時の工
数、部品点数を減らすことができるので、従来のものと
比べて、コストを下げることができる。FIG. 4 shows the position of the pole 18 and the amount of developer deposited on the carrier recovery member 12, where the facing position is 0 ° and the moving direction side is −. When the poles 18 are located inward (-direction) with respect to the moving direction, the developer can be drawn into the developing device.
It can be seen that the amount of deposition decreases. However, at 15 °, the pole 18 separates, so the amount of deposition increases. For this reason, it is desirable to have a few degrees to 10 degrees inside. The scraper 21 scrapes off toner and paper dust that cannot be attracted by the magnetic force. In this way, by using a single permanent magnet for the carrier recovery member, the collection carrier can be stably transported, and the number of manufacturing steps and the number of parts can be reduced. In comparison, the cost can be reduced.
【００１３】上記の説明においては、画像形成装置の現
像機、方式は図１のような構成、方式としたが、現像剤
担持体の回転方向、現像剤担持体本数、撹拌部材の形
状、撹拌補助部材の形状、傾斜案内板の形状、仕切り板
構造等は、これに限定されるものではなく本発明の効果
を得ることができる。In the above description, the developing machine of the image forming apparatus and the system have the configuration and system as shown in FIG. 1, but the rotation direction of the developer carrying member, the number of developer carrying members, the shape of the stirring member, and the stirring method. The shape of the auxiliary member, the shape of the inclined guide plate, the partition plate structure, and the like are not limited to these, and the effects of the present invention can be obtained.
【００１４】[0014]
【発明の効果】以上のように本発明によれば、補集キャ
リアをキャリア回収部材から現像剤担持体に搬送する際
に、現像剤担持体に設けられた極と磁気干渉を起こすこ
とがなく、円滑に現像剤を搬送することができる。As described above, according to the present invention, when the collecting carrier is transported from the carrier collecting member to the developer carrying member, magnetic interference with the pole provided on the developer carrying member does not occur. Therefore, the developer can be transported smoothly.
【図１】本発明の一実施例を示した現像装置の断面図で
ある。FIG. 1 is a sectional view of a developing device showing an embodiment of the present invention.
【図２】現像剤担持体間とキャリア回収部材間の磁界を
表した説明図である。FIG. 2 is an explanatory diagram showing a magnetic field between a developer carrier and a carrier recovery member.
【図３】異極により生じる磁束密度と現像剤堆積量の関
係を示す説明図である。FIG. 3 is an explanatory diagram showing a relationship between a magnetic flux density generated by different poles and a developer deposition amount.
【図４】搬送極位置と現像剤堆積量を表した説明図であ
る。FIG. 4 is an explanatory diagram showing a transport pole position and a developer deposition amount.
４は現像剤担持体、６は永久磁石、７はスリーブ、９は
感光体、１２はキャリア回収部材、１３は永久磁石、１
４はスリーブである。4 is a developer carrying member, 6 is a permanent magnet, 7 is a sleeve, 9 is a photosensitive member, 12 is a carrier collecting member, 13 is a permanent magnet, 1
4 is a sleeve.
Claims (3)
吸着搬送する現像剤担持体の近傍に単一の永久磁石から
なるキャリア回収部材を設け、記録体上に付着したキャ
リアおよび前記現像剤担持体から飛散したキャリアを補
集回収するようにした現像装置において、前記キャリア
回収部材と前記現像剤担持体との間に生じる磁界によっ
て捕集したキャリアを移動せしめることを特徴とする現
像装置。1. A carrier collecting member composed of a single permanent magnet is provided in the vicinity of a developer carrying member that adsorbs and conveys a developer containing a toner and a carrier as main components, and the carrier and the developer adhered to a recording member. A developing device in which a carrier scattered from a carrier is collected and collected, wherein the carrier collected by a magnetic field generated between the carrier collecting member and the developer carrier is moved.
対向面よりも移動方向に対し内側に、捕集キャリア搬送
極を設け、該搬送極は前記キャリア回収部材の記録体に
対向する磁極と異極であることを特徴とする請求項１記
載の現像装置。2. A collecting carrier transport pole is provided inside a surface of the developer carrying body facing the carrier collecting member with respect to a moving direction, and the transport pole is a magnetic pole facing the recording body of the carrier collecting member. 2. The developing device according to claim 1, wherein the developing device has a different polarity.
磁石によって生じた磁力と異極性の磁力が生じており、
異極性の磁力ピークを１５０ガウス以下としたことを特
徴とする請求項１記載の現像装置。3. A magnetic force having a polarity different from that generated by a single magnet is generated on the outer circumference of the carrier recovery member.
2. The developing device according to claim 1, wherein the peak of magnetic force of different polarity is 150 gauss or less.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP15072495A JPH096139A (en) | 1995-06-16 | 1995-06-16 | Developing device |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP15072495A JPH096139A (en) | 1995-06-16 | 1995-06-16 | Developing device |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH096139A true JPH096139A (en) | 1997-01-10 |
Family
ID=15503030
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP15072495A Withdrawn JPH096139A (en) | 1995-06-16 | 1995-06-16 | Developing device |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH096139A (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6810222B2 (en) * | 2001-08-29 | 2004-10-26 | Ricoh Company, Ltd. | Image forming apparatus including an image carrier, a latent image forming means, and a developing device capable of preventing developer from escaping the developing device, and process cartridge therefore |
| US8014706B2 (en) | 2007-03-02 | 2011-09-06 | Ricoh Company, Ltd. | Developing device, process cartridge, and image forming apparatus |
-
1995
- 1995-06-16 JP JP15072495A patent/JPH096139A/en not_active Withdrawn
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6810222B2 (en) * | 2001-08-29 | 2004-10-26 | Ricoh Company, Ltd. | Image forming apparatus including an image carrier, a latent image forming means, and a developing device capable of preventing developer from escaping the developing device, and process cartridge therefore |
| US8014706B2 (en) | 2007-03-02 | 2011-09-06 | Ricoh Company, Ltd. | Developing device, process cartridge, and image forming apparatus |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| A300 | Withdrawal of application because of no request for examination |
Free format text: JAPANESE INTERMEDIATE CODE: A300 Effective date: 20020903 |