JP2000206792A - Developing device - Google Patents
Developing deviceInfo
- Publication number
- JP2000206792A JP2000206792A JP11009151A JP915199A JP2000206792A JP 2000206792 A JP2000206792 A JP 2000206792A JP 11009151 A JP11009151 A JP 11009151A JP 915199 A JP915199 A JP 915199A JP 2000206792 A JP2000206792 A JP 2000206792A
- Authority
- JP
- Japan
- Prior art keywords
- developer
- magnetic
- carrier
- sleeve
- developing
- 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.)
- Pending
Links
Landscapes
- Hard Magnetic Materials (AREA)
- Magnetic Brush Developing In Electrophotography (AREA)
- Dry Development In Electrophotography (AREA)
Abstract
Description
【０００１】[0001]
【発明の属する技術分野】本発明は、電子写真方式もし
くは静電記録方式の画像形成装置に用いられる２成分現
像剤を使用した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 a developing device using a two-component developer used in an electrophotographic or electrostatic recording type image forming apparatus.
【０００２】[0002]
【従来の技術】従来から、２成分現像剤の磁気ブラシに
より現像を行う現像装置は、図４に示すような構成がと
られている。2. Description of the Related Art Conventionally, a developing device for performing development using a magnetic brush of a two-component developer has a configuration as shown in FIG.
【０００３】この現像装置は、磁性キャリアと非磁性ト
ナーとからなる２成分現像剤を収容した現像容器２を備
え、現像容器２内には隔壁２ａで隔てられた現像剤撹拌
スクリュー４および６が配設され、また現像容器２の感
光ドラム１００と対した開口部には、現像剤担持体とし
ての現像スリーブ１０が配設されている。This developing device includes a developing container 2 containing a two-component developer composed of a magnetic carrier and a non-magnetic toner. In the developing container 2, developer stirring screws 4 and 6 separated by a partition 2a are provided. A developing sleeve 10 as a developer carrier is provided at an opening of the developing container 2 facing the photosensitive drum 100.
【０００４】現像スリーブ１０は非磁性材料の円筒体か
らなり、矢印ａ方向に回転する感光ドラム１００に対し
て所定間隙をあけて配置され、矢印ｂ方向に回転駆動さ
れる。この現像スリーブ１０の内側には、磁界発生手段
として磁化されたマグネットローラ１１が設置され、マ
グネットローラ１１は現像スリーブ１０の回転に対して
非回転に配置されている。The developing sleeve 10 is formed of a cylindrical body made of a non-magnetic material, is disposed at a predetermined distance from the photosensitive drum 100 rotating in the direction of arrow a, and is driven to rotate in the direction of arrow b. A magnet roller 11 magnetized as a magnetic field generating means is provided inside the developing sleeve 10, and the magnet roller 11 is arranged so as not to rotate with respect to the rotation of the developing sleeve 10.
【０００５】現像容器２内の２成分現像剤は、上記のス
クリュー４による搬送およびスクリュー６による搬送で
容器２内を循環され、そのスクリュー４による搬送過程
で、マグネットローラ１１の磁極Ｎ３により現像スリー
ブ１０上に汲み上げられ、現像スリーブ１０の回転にと
もない現像スリーブ１０上をＳ２極→Ｎ１極→Ｓ１極と
搬送される。その搬送途上で現像剤は、現像スリーブ１
０に対して磁極Ｓ２の対向部近傍に非接触で配置された
規制ブレード３０によって層厚を規制され、現像スリー
ブ１０上に現像剤の薄層が形成される。The two-component developer in the developing container 2 is circulated in the container 2 by the above-mentioned screw 4 and the screw 6, and in the course of the screw 4, the developing sleeve is moved by the magnetic pole N 3 of the magnet roller 11. The developing sleeve 10 is conveyed in the order of S2 pole → N1 pole → S1 pole as the developing sleeve 10 rotates. During the conveyance, the developer is
The layer thickness is regulated by a regulating blade 30 arranged in a non-contact manner in the vicinity of a portion facing the magnetic pole S2 with respect to 0, and a thin layer of the developer is formed on the developing sleeve 10.
【０００６】マグネットローラ１１の磁極Ｎ１は現像主
極であり、現像スリーブ１０と感光ドラム１とが対向し
た現像部に位置している。現像スリーブ１０により現像
部に搬送された現像剤は、現像主極Ｎ１の磁力によって
穂立ちして磁気ブラシに形成され、その磁気ブラシの現
像剤により感光ドラム１００上に形成された静電潜像を
現像する。The magnetic pole N1 of the magnet roller 11 is a main developing pole, and is located at a developing section where the developing sleeve 10 and the photosensitive drum 1 are opposed to each other. The developer conveyed to the developing unit by the developing sleeve 10 rises up by the magnetic force of the developing main pole N1 to form a magnetic brush, and the electrostatic latent image formed on the photosensitive drum 100 by the developer of the magnetic brush. Develop.
【０００７】現像を終了した現像剤は、その後、現像ス
リーブ１０の回転により現像容器２内に戻され、マグネ
ットローラ１１の磁極Ｓ１をすぎた後、磁極Ｎ２、Ｎ３
の反撥磁界により現像スリーブ１０から除去され、容器
２内に落下、回収される。After the development is completed, the developer is returned into the developing container 2 by the rotation of the developing sleeve 10, and after passing the magnetic pole S 1 of the magnet roller 11, the magnetic poles N 2, N 3
Is removed from the developing sleeve 10 by the repelling magnetic field, and falls into the container 2 and is collected.
【０００８】[0008]
【発明が解決しようとする課題】しかしながら、このよ
うな従来の現像装置においては、規制ブレード３０によ
り規制され残った現像剤が、規制ブレード３０の現像ス
リーブ１０の回転方向上流側付近に、磁極Ｓ２とＮ３の
２極により発生する磁界の力により大量に保持されて溜
まり、さらに現像スリーブ１０によって現像剤がつぎつ
ぎと搬送されてくるので、現像剤に大きな圧力がかか
る。However, in such a conventional developing device, the developer regulated by the regulating blade 30 is left near the upstream of the regulating blade 30 in the rotation direction of the developing sleeve 10 by the magnetic pole S2. And a large amount of the magnetic field generated by the two poles N3 and N3, and the developer is conveyed by the developing sleeve 10 one after another, so that a large pressure is applied to the developer.
【０００９】このため、規制ブレード３０の付近に溜ま
った現像剤には、磁性キャリアとトナーの間に大きな力
が加わって、トナーに外添されたＳｉＯ２等の微粉粒子
がトナー（樹脂が主成分）の中に埋め込まれるといった
現象が発生する。さらにトナーの形状自体も磁性キャリ
アとの衝突によって角が取れて、丸みを帯びてくる。ま
た長時間使用すると、磁性キャリアの表面にトナーが付
着してとれなくなるいわゆるスペント現象が生じる。For this reason, a large force is applied between the magnetic carrier and the toner to the developer accumulated near the regulating blade 30, and fine powder particles such as SiO 2 externally added to the toner are removed from the toner (main component is resin). ) Occurs. Furthermore, the shape of the toner itself is rounded due to collision with the magnetic carrier, so that the shape is rounded. When used for a long time, a so-called spent phenomenon occurs in which the toner adheres to the surface of the magnetic carrier and cannot be removed.
【００１０】このような現象が生じると、トナーの摩擦
帯電量（トリボ）が使用時間とともに変化し、画像濃度
が変化したり、磁性キャリアや感光ドラムに対するトナ
ーの機械的付着力が増大し、電界に対応した現像や転写
が行われにくくなり、現像トナーの部分的欠落（ムラ）
が発生してしまう。すなわち、初期の画像と比べると、
使用とともに極めて印象の悪い画像になる。When such a phenomenon occurs, the amount of triboelectric charge (tribo) of the toner changes with use time, the image density changes, the mechanical adhesion of the toner to the magnetic carrier or the photosensitive drum increases, and the electric field increases. It is difficult to perform development and transfer in accordance with the conditions, and partial omission (unevenness) of developed toner
Will occur. That is, compared to the initial image,
The image becomes extremely poor with use.
【００１１】これを防ぐ方法として、図５に示すよう
に、反撥磁極を形成する同極の２極Ｎ２、Ｎ３のうち、
現像スリーブ１０の回転方向下流側の磁極Ｎ３を、現像
スリーブ１０の鉛直方向最下点から現像スリーブ回転方
向に９０゜の間のθの位置に配置し、この磁極Ｎ３の対
向位置近傍に規制ブレード３０を配置し、かつ規制ブレ
ード３０を、現像スリーブ１０の周方向上の接線方向に
対して、現像スリーブ回転方向にα＝９０゜〜１８０゜
の角度をなすように配置する現像装置が提案されている
（特願平１０−１９６５５８）。図５において、図４に
付した符号と同一の符号は同一の部材を示す。As a method for preventing this, as shown in FIG. 5, of the two poles N2 and N3 of the same polarity forming a repelling magnetic pole,
The magnetic pole N3 on the downstream side in the rotation direction of the developing sleeve 10 is disposed at a position of θ between 90 ° in the rotation direction of the developing sleeve from the lowest point in the vertical direction of the developing sleeve 10, and a regulating blade is provided near the position facing the magnetic pole N3. A developing device in which the regulating blade 30 is arranged and the regulating blade 30 is arranged at an angle of α = 90 ° to 180 ° in the developing sleeve rotation direction with respect to the tangential direction in the circumferential direction of the developing sleeve 10. (Japanese Patent Application No. 10-196558). 5, the same reference numerals as those shown in FIG. 4 denote the same members.
【００１２】このような構成とすることにより、規制ブ
レード３０の上流側に溜まる現像剤量を大幅に減少し
て、現像剤の劣化を低減することができる。With such a configuration, the amount of the developer accumulated on the upstream side of the regulating blade 30 can be greatly reduced, and the deterioration of the developer can be reduced.
【００１３】しかしながら、現像剤規制部材として金属
板等からなる規制ブレード３０を用いた場合、一般に、
強度を確保するために、規制ブレード３０の厚さを約１
ｍｍ以上と厚くしている。このため、規制ブレード３０
を、上記のように、現像スリーブ１０の周方向上の接線
方向に対して、現像スリーブ回転方向にα＝９０゜〜１
８０゜の角度をなすように配置すると、規制ブレード３
０先端の現像スリーブ回転方向下流側の部分が、現像ス
リーブ１０の周面に対する最近接点となり、規制ブレー
ド３０の先端面と現像スリーブ１０の周面との間に、現
像スリーブ１０の回転方向下流側に向けて間隔が狭くな
るくさび状の領域Ｓが形成される。However, when a regulating blade 30 made of a metal plate or the like is used as a developer regulating member, generally,
In order to secure the strength, the thickness of the regulating blade 30 is set to about 1
mm or more. For this reason, the regulating blade 30
As described above, with respect to the tangential direction in the circumferential direction of the developing sleeve 10, α = 90 ° to 1 in the rotational direction of the developing sleeve.
When they are arranged at an angle of 80 °, the regulating blade 3
The portion of the leading end on the downstream side in the rotation direction of the developing sleeve is the closest point to the peripheral surface of the developing sleeve 10, and is located between the leading end surface of the regulating blade 30 and the peripheral surface of the developing sleeve 10 on the downstream side in the rotating direction of the developing sleeve 10. , A wedge-shaped region S having a smaller interval is formed.
【００１４】すなわち、規制ブレード３０の現像スリー
ブ回転方向上流側面の先端で規制され、排除されて余っ
た現像剤は、規制ブレード３０の上流側面に沿って流れ
て落下するので、規制ブレード３０の上流側に大量の現
像剤が溜まることはなく、現像剤が大きな圧力を受ける
ことはないが、規制ブレード３０の現像スリーブ回転方
向上流側面の先端での規制後に現像スリーブ１０上に残
った現像剤は、搬送されて上記のくさび状の領域Ｓに入
り込み、強く圧迫される。That is, the developer regulated at the tip of the regulating blade 30 on the upstream side in the rotation direction of the developing sleeve and remaining and removed is flowed along the upstream side of the regulating blade 30 and falls. A large amount of developer does not accumulate on the side, and the developer does not receive a large pressure, but the developer remaining on the developing sleeve 10 after the regulation at the tip of the regulating blade 30 on the upstream side in the developing sleeve rotation direction is Is conveyed, enters the wedge-shaped region S, and is strongly pressed.
【００１５】このようにくさび状の部分Ｓに入り込む現
像剤は少量であるが、現像装置を長期間使い続けると、
現像剤中に劣化した現像剤が増加していくことが分かっ
た。また、このようなくさび状の規制部では、凝集した
トナーあるいは異物が入って、規制ブレード３０の先端
部につまりやすく、現像スリーブ１０上の現像剤の層厚
にムラが生じて、その結果、現像された画像に濃度ムラ
が発生しやすい。また、このように規制部で現像剤が強
く圧迫される現像装置は、高速で現像スリーブを回転さ
せて使用すると、くさび状の部分で圧迫された現像剤自
体が凝集体を形成してしまうことがあった。Although a small amount of the developer enters the wedge-shaped portion S, if the developing device is used for a long period of time,
It was found that the amount of deteriorated developer in the developer increased. Further, in such a wedge-shaped regulating portion, agglomerated toner or foreign matter enters and easily clogs the tip of the regulating blade 30, causing unevenness in the layer thickness of the developer on the developing sleeve 10. Density unevenness is likely to occur in the developed image. Also, in such a developing device in which the developer is strongly pressed by the regulating portion, when the developing sleeve is rotated at a high speed and used, the developer itself pressed in the wedge-shaped portion may form an aggregate. was there.
【００１６】本発明の目的は、現像剤規制部材上で２成
分現像剤に大きな圧力がかかるのを防止し、長期間の使
用によっても現像剤の劣化等がない現像装置を提供する
ことである。An object of the present invention is to provide a developing device which prevents a large pressure from being applied to a two-component developer on a developer regulating member and which does not deteriorate the developer even after long-term use. .
【００１７】[0017]
【課題を解決するための手段】上記目的は本発明に係る
現像装置にて達成される。要約すれば、本発明は、現像
容器に収容された２成分現像剤を、磁界発生手段を内蔵
した回転する現像剤担持体上に担持し、担持された現像
剤の層厚を前記現像剤担持体に近接して設置された現像
剤規制部材で規制しながら、像担持体と対向した現像部
へ搬送し、該現像部で現像剤を像担持体上に形成された
静電潜像の現像に供する現像装置において、前記磁界発
生手段は、前記現像部よりも前記現像剤担持体の回転方
向下流側でかつ現像容器内に位置する第１の磁極と、該
第１の磁極の前記現像剤担持体の回転方向下流側でかつ
前記第１の磁極に隣接して位置する同極性の第２の磁極
とを有し、前記第１の磁極および前記第２の磁極間に
は、前記現像剤担持体表面の垂直方向の磁束密度Ｂｒが
８０ガウス以下でかつ水平方向の磁束密度Ｂθが８０ガ
ウス以下である領域を有し、前記現像剤担持体の鉛直方
向最下点から前記現像剤担持体の回転方向に９０゜の間
の位置に、前記現像剤規制部材を前記現像剤担持体と非
接触に設置するとともに、前記現像剤規制部材の前記現
像剤担持体の回転方向上流側の面が、前記現像剤担持体
の周方向上の接線方向に対して前記現像剤担持体の回転
方向に９０゜〜１８０゜の角度をなすように、前記現像
剤規制部材を前記現像剤担持体に対して配置し、さらに
前記現像剤規制部材の先端を、前記現像剤担持体の回転
方向上流側で前記現像剤担持体に最近接する傾斜形状に
形成し、そして前記第２の磁極を前記現像剤規制部材の
最近接部の対向位置近傍に配置したことを特徴とする現
像装置である。The above object is achieved by a developing apparatus according to the present invention. In summary, the present invention provides a two-component developer contained in a developing container, which is supported on a rotating developer carrier having a built-in magnetic field generating means. The developer is conveyed to a developing section facing the image carrier while being regulated by a developer regulating member provided close to the body, and the developer is used to develop the electrostatic latent image formed on the image carrier. Wherein the magnetic field generating means comprises: a first magnetic pole located in the developing container at a position downstream of the developing section in the rotation direction of the developer carrier; and the developer of the first magnetic pole. A second magnetic pole of the same polarity, which is located on the downstream side in the rotation direction of the carrier and adjacent to the first magnetic pole, wherein the developer is provided between the first magnetic pole and the second magnetic pole; The magnetic flux density Br in the vertical direction on the carrier surface is 80 Gauss or less and the magnetic flux density Bθ in the horizontal direction The developer regulating member has an area that is equal to or less than 80 Gauss, and the developer regulating member is disposed at a position between 90 degrees in the rotation direction of the developer carrier from the lowest point in the vertical direction of the developer carrier. And the surface of the developer regulating member on the upstream side in the rotation direction of the developer carrier is rotated with respect to the tangential direction in the circumferential direction of the developer carrier. The developer regulating member is arranged with respect to the developer carrier so as to form an angle of 90 ° to 180 ° with respect to the direction, and further, the tip of the developer regulating member is moved upstream in the rotation direction of the developer carrier. The developing device is formed in an inclined shape closest to the developer carrier on the side, and the second magnetic pole is arranged in the vicinity of a position facing a closest portion of the developer regulating member.
【００１８】本発明によれば、前記現像剤規制部材は、
非磁性部材と、該非磁性部材の先端部であって、前記現
像剤担持体の回転方向上流側の部分に設けられた磁性部
材とからなることができる。According to the present invention, the developer regulating member comprises:
A non-magnetic member, and a magnetic member provided at a tip portion of the non-magnetic member and at a portion on the upstream side in the rotation direction of the developer carrying member can be provided.
【００１９】[0019]
【発明の実施の形態】以下、本発明に係る実施例を図面
に則して更に詳しく説明する。Embodiments of the present invention will be described below in more detail with reference to the drawings.
【００２０】実施例１ 図１は、本発明の現像装置の一実施例を示す断面図であ
る。Embodiment 1 FIG. 1 is a sectional view showing an embodiment of the developing device of the present invention.
【００２１】本実施例の現像装置は、図５に示した従来
の現像装置と同様、磁性キャリアと非磁性トナーとから
なる２成分現像剤を収容した現像容器２を備え、現像容
器２内には隔壁２ａで隔てられた現像剤撹拌スクリュー
４および６が配設され、また現像容器２の感光ドラム１
００と対した開口部には、現像剤担持体としての現像ス
リーブ１０が配設され、現像スリーブ１０内には磁界発
生手段としてマグネットローラ１１が非回転に配設さ
れ、さらに現像スリーブ２の回転方向下流側の現像容器
２の開口部の部分には、規制ブレード３０が設置されて
いる。The developing device of the present embodiment includes a developing container 2 containing a two-component developer composed of a magnetic carrier and a non-magnetic toner, similarly to the conventional developing device shown in FIG. Are provided with developer stirring screws 4 and 6 separated by a partition 2a.
A developing sleeve 10 as a developer carrying member is disposed in the opening facing 00, and a magnet roller 11 is non-rotatably disposed within the developing sleeve 10 as a magnetic field generating means. A regulating blade 30 is provided at an opening portion of the developing container 2 on the downstream side in the direction.
【００２２】現像スリーブ１０はＳＵＳ３１６等の非磁
性材料の円筒体からなり、矢印ａ方向に回転する感光ド
ラム１００に対して所定間隙をあけて配置され、矢印ｂ
方向に回転駆動される。現像スリーブ１０内のマグネッ
トローラ１１は、５つの磁極Ｓ１、Ｓ２、Ｎ１、Ｎ２、
Ｎ３を有している。The developing sleeve 10 is made of a cylindrical body made of a non-magnetic material such as SUS316, and is arranged at a predetermined distance from the photosensitive drum 100 rotating in the direction of arrow a.
It is driven to rotate in the direction. The magnet roller 11 in the developing sleeve 10 has five magnetic poles S1, S2, N1, N2,
N3.
【００２３】この５つの磁極のうち、現像容器２内に位
置する磁極Ｎ２、Ｎ３は、現像容器２内に戻された現像
剤を現像スリーブ１０から除去する反撥磁極を形成して
おり、磁極Ｎ２、Ｎ３は、これら磁極Ｎ２、Ｎ３間に、
現像スリーブ１０表面の垂直方向の磁束密度Ｂｒが８０
ガウス以下、かつ水平方向の磁束密度Ｂθが８０ガウス
以下である領域を有する。Of the five magnetic poles, the magnetic poles N2 and N3 located in the developing container 2 form a repelling magnetic pole for removing the developer returned into the developing container 2 from the developing sleeve 10. , N3 are located between these magnetic poles N2, N3.
The magnetic flux density Br in the vertical direction on the surface of the developing sleeve 10 is 80
It has a region where the magnetic flux density Bθ in the horizontal direction is equal to or less than 80 Gauss.
【００２４】現像容器２内の２成分現像剤は、現像剤搬
送スクリュー４により撹拌しながら、図の紙面の垂直方
向奥側から手前側に搬送され、この搬送過程でマグネッ
トローラ１１の磁極Ｎ３により現像スリーブ１０上に汲
み上げられる。本実施例では、磁極Ｎ３の現像スリーブ
１０表面での最大磁束密度を６００ガウス、磁束密度の
半値幅を３０゜とした。この磁極Ｎ３は、規制ブレード
３０の対向部近傍に配設した。The two-component developer in the developing container 2 is conveyed from the back side in the vertical direction of the drawing to the front side while being stirred by the developer conveying screw 4, and is conveyed by the magnetic pole N 3 of the magnet roller 11 in this conveying process. It is pumped onto the developing sleeve 10. In the present embodiment, the maximum magnetic flux density of the magnetic pole N3 on the surface of the developing sleeve 10 is 600 gauss, and the half value width of the magnetic flux density is 30 °. The magnetic pole N3 is disposed near the opposing portion of the regulating blade 30.
【００２５】規制ブレード３０は、現像スリーブ１０の
鉛直方向最下点から現像スリーブ回転方向に９０゜の間
の角度θの位置に、現像スリーブ１０と非接触に設置す
る。The regulating blade 30 is installed at a position at an angle θ between the lowermost point of the developing sleeve 10 in the vertical direction and 90 ° in the rotating direction of the developing sleeve 10 without contact with the developing sleeve 10.
【００２６】本実施例によれば、図２に示すように、規
制ブレード３０は、磁極Ｎ３の最大磁束密度位置の現像
スリーブ回転方向５゜下流で、現像スリーブ１０の鉛直
方向最下点から現像スリーブ回転方向にθ＝６０゜の位
置に、現像スリーブ１０との最近接部を有し、かつ規制
ブレード３０の現像スリーブ回転方向上流側の面が、現
像スリーブ１０の周方向上の接線方向に対して回転方向
にα＝１２０゜の角度をなすように配置した。According to the present embodiment, as shown in FIG. 2, the regulating blade 30 moves the developing sleeve 10 from the lowest point in the vertical direction of the developing sleeve 10 downstream of the maximum magnetic flux density position of the magnetic pole N3 by 5 ° in the developing sleeve rotation direction. At the position of θ = 60 ° in the sleeve rotation direction, a portion closest to the development sleeve 10 is provided, and the surface of the regulating blade 30 on the upstream side in the development sleeve rotation direction is in the tangential direction in the circumferential direction of the development sleeve 10. On the other hand, they were arranged so as to form an angle of α = 120 ° in the rotation direction.
【００２７】また、規制ブレード３０の現像スリーブ回
転方向上流側の先端３０ａにおいて、現像スリーブ１０
と最近接点をなすように、鋭角の先端角度β＝４５゜
で、規制ブレード３０の先端を下流側面に向けてナイフ
状に傾斜させた。規制ブレード３０の最近接部先端３０
ａにおける現像スリーブ１０周面との距離は４００μｍ
とした。At the tip 30a of the regulating blade 30 on the upstream side in the developing sleeve rotation direction, the developing sleeve 10
The tip of the regulating blade 30 was inclined like a knife toward the downstream side at an acute tip angle β = 45 ° so as to make the closest contact with the blade. The tip 30 of the closest part of the regulating blade 30
a is 400 μm from the peripheral surface of the developing sleeve 10
And
【００２８】上記の磁極Ｎ３で汲み上げられた現像剤
は、磁極Ｎ３の５゜下流側で、最近接部先端３０ａにお
ける現像スリーブ１０との間隔が４００ｍｍ規制ブレー
ド３０により、約４５ｍｇ／ｃｍ2の層厚に規制され
る。規制部で余った現像剤は、規制ブレード３０に沿っ
て現像スリーブ１０から離れる方向に押し出され、磁極
Ｎ３の磁界が及びにくくなると、速やかにスクリュー４
上に落下する。The developer pumped up by the magnetic pole N3 has a layer of about 45 mg / cm 2 at a distance of 5 mm downstream of the magnetic pole N3 from the developing sleeve 10 at the nearest end 30a by a 400 mm regulating blade 30. The thickness is regulated. The developer remaining in the regulating portion is pushed out in a direction away from the developing sleeve 10 along the regulating blade 30, and when the magnetic field of the magnetic pole N3 becomes difficult to spread, the screw 4
Fall on.
【００２９】このようにして規制ブレード３０上流側の
最近接部先端３０ａで層厚が規制された現像剤は、現像
スリーブ回転方向に規制ブレード３０の先端と現像スリ
ーブ１０との間の間隔が広がっているので、規制ブレー
ド３０の先端で圧迫されることなく規制ブレード３０を
通過して、現像スリーブ１０の回転にともない現像スリ
ーブ１０上をＳ２極→Ｎ１極と搬送される。現像主極で
ある磁極Ｎ１の近傍に至った現像剤は、磁極Ｎ１により
穂立ちして磁気ブラシに形成され、感光ドラム１００上
の静電潜像の現像に供される。As described above, the developer whose layer thickness is regulated at the distal end 30a on the upstream side of the regulating blade 30 has an increased distance between the leading end of the regulating blade 30 and the developing sleeve 10 in the developing sleeve rotation direction. Therefore, the developer passes through the regulating blade 30 without being pressed by the tip of the regulating blade 30, and is conveyed from the S2 pole to the N1 pole on the developing sleeve 10 as the developing sleeve 10 rotates. The developer that has reached the vicinity of the magnetic pole N1 which is the main developing pole is raised by the magnetic pole N1 to form a magnetic brush, and is used for developing the electrostatic latent image on the photosensitive drum 100.
【００３０】現像を終了した現像剤は、その後、現像ス
リーブ１０の回転により現像容器２内に戻され、磁極Ｓ
１→Ｎ２極へと搬送され、磁極Ｎ２、Ｎ３間の現像スリ
ーブ１０周面での垂直方向の磁界の強さＢｒが５０ガウ
ス以下で、水平方向の磁界の強さが５０ガウス以下の領
域で、現像スリーブ１０から除去され、搬送スクリュー
４上に落下する。落下した現像剤はスクリュー４によ
り、図の紙面に対する垂直方向奥側に搬送してスクリュ
ー６に受け渡される。After the development is completed, the developer is returned into the developing container 2 by the rotation of the developing sleeve 10, and the magnetic pole S
1 → N2 pole in a region where the magnetic field strength Br in the vertical direction on the peripheral surface of the developing sleeve 10 between the magnetic poles N2 and N3 is 50 Gauss or less and the magnetic field strength in the horizontal direction is 50 Gauss or less. Is removed from the developing sleeve 10 and falls on the transport screw 4. The dropped developer is conveyed by the screw 4 to the back in the vertical direction with respect to the sheet of FIG.
【００３１】規制ブレード３０での規制によって現像ス
リーブ１０上に残らずに余った現像剤は、上記したよう
に、規制ブレード３０に沿って移動して、磁極Ｎ３で保
持できない現像剤は、速やかにスクリュー４上へと落下
するので、規制ブレード３０の現像スリーブ１０の回転
方向下流側の近傍に、現像剤の大きな溜まりが発生する
ことがなく、現像剤の劣化が少ない。また、規制ブレー
ド３０の先端部に従来のようなくさび状領域がないの
で、規制部で現像剤が圧迫されて劣化したり、ストレス
を受けて凝集体を形成したりすることがなく、現像剤の
寿命を向上できる。また凝集トナーや異物が規制部につ
まって現像ムラを生じたりすることも、従来よりも起こ
りにくい。As described above, the remaining developer remaining on the developing sleeve 10 due to the regulation by the regulating blade 30 moves along the regulating blade 30, and the developer that cannot be held by the magnetic pole N3 is promptly removed. Since the developer drops onto the screw 4, a large accumulation of the developer does not occur near the downstream side of the regulating blade 30 in the rotation direction of the developing sleeve 10, and the deterioration of the developer is small. Further, since there is no wedge-shaped region at the tip portion of the regulating blade 30 as in the related art, the developer is not pressed by the regulating portion and deteriorates, and the aggregate does not form due to stress. Life can be improved. Also, the occurrence of uneven development due to the aggregation toner and foreign matters clogging the regulating portion is less likely than in the related art.
【００３２】なお、規制ブレード３０の先端角度βは
（１８０−α）度よりも小さければ、現像剤が規制部で
強く圧迫されることはなく、現像剤の劣化低減に効果が
ある。If the tip angle β of the regulating blade 30 is smaller than (180-α) degrees, the developer is not strongly pressed by the regulating portion, which is effective in reducing the deterioration of the developer.
【００３３】本実施例において、規制ブレード３０の角
度α＝１２０゜、β＝４５゜である本実施例の現像装置
と、α＝１２０゜、β＝９０゜である従来の現像装置と
を現像に用いて、画像形成を行い、得られた画像の画質
と現像装置の空回転時間とから、現像剤の劣化を判断し
て比較したところ、本実施例の現像装置では、従来の現
像装置の約２倍の空回転を行っても、ほぼ同等の現像剤
劣化に抑えることができた。In the present embodiment, the developing device of the present embodiment in which the angles α of the regulating blade 30 are α = 120 ° and β = 45 ° and the conventional developing device in which α = 120 ° and β = 90 ° are developed. The image forming apparatus was used to determine the deterioration of the developer based on the image quality of the obtained image and the idle rotation time of the developing device, and a comparison was made. Even when the idle rotation was about twice, it was possible to suppress almost the same deterioration of the developer.
【００３４】実施例２ 図３は、本発明の現像装置の他の実施例を示す断面図で
ある。Embodiment 2 FIG. 3 is a sectional view showing another embodiment of the developing device of the present invention.
【００３５】本実施例では、非磁性材料で形成された先
端角度β＝４５゜のナイフ状の規制ブレード３０が、現
像スリーブ１０に対し実施例１と同様に配置されている
が、規制ブレード３０の現像スリーブ回転方向上流側の
面の先端から２００μｍの位置に、規制ブレード３０の
長手方向（現像スリーブ１０の長手方向と同方向）に延
びる厚さ３００μｍ、幅３ｍｍの磁性板３１、たとえば
鉄板を接着した。In this embodiment, the knife-shaped regulating blade 30 made of a nonmagnetic material and having a tip angle β = 45 ° is arranged on the developing sleeve 10 in the same manner as in the first embodiment. A magnetic plate 31 having a thickness of 300 μm and a width of 3 mm, for example, an iron plate, extending in the longitudinal direction of the regulating blade 30 (in the same direction as the longitudinal direction of the developing sleeve 10) is placed at a position 200 μm from the tip of the surface on the upstream side in the developing sleeve rotation direction. Glued.
【００３６】これによれば、規制ブレード３０の現像ス
リーブ回転方向上流側の現像剤は、磁極Ｎ３と磁性板３
１との間で形成される磁界により、磁性板３１に引かれ
るように磁気ブラシを形成するので、規制ブレード３０
の上流側に現像剤の密度が低い疎な状態が形成される。According to this, the developer on the upstream side in the rotation direction of the developing sleeve of the regulating blade 30 includes the magnetic pole N3 and the magnetic plate 3
The magnetic brush is formed so as to be attracted to the magnetic plate 31 by the magnetic field formed between the control blade 30 and the regulating blade 30.
A sparse state where the density of the developer is low is formed on the upstream side of.
【００３７】このように磁性板３１で現像剤の密度を低
くして、磁性板３１直後の規制ブレード３０で現像剤を
規制すれば、規制ブレード３０の現像スリーブ１０との
最近接距離を大きく設定しても、現像剤層厚を薄く規制
することができる。たとえば実施例１では、規制ブレー
ド３０の現像スリーブ１０との最近接距離が４００μｍ
で、現像剤層厚を塗布量換算で約４５ｍｇ／ｃｍ2得る
ことができたが、本実施例では、最近接距離が６００μ
ｍでほぼ同じ現像剤層厚が得られる。When the developer density is reduced by the magnetic plate 31 and the developer is regulated by the regulating blade 30 immediately after the magnetic plate 31, the closest distance between the regulating blade 30 and the developing sleeve 10 is set large. Even in this case, the thickness of the developer layer can be regulated to be thin. For example, in the first embodiment, the closest distance between the regulating blade 30 and the developing sleeve 10 is 400 μm.
As a result, a developer layer thickness of about 45 mg / cm 2 could be obtained in terms of a coating amount, but in this embodiment, the closest distance was 600 μm.
With m, almost the same developer layer thickness can be obtained.
【００３８】本実施例によれば、上記のように、規制ブ
レード３０の上流側の現像スリーブ１０との最近接距離
を大きくすることができるので、規制部に凝集したトナ
ーや異物がつまるのを一層防止することができる。また
規制部での現像剤の密度が低いので、規制部において現
像剤にかかるストレスが低減され、規制ブレード３０の
先端部で凝集体を作ることもない。According to the present embodiment, as described above, the closest distance between the regulating blade 30 and the developing sleeve 10 on the upstream side can be increased. It can be further prevented. In addition, since the density of the developer in the regulating portion is low, the stress applied to the developer in the regulating portion is reduced, and no aggregate is formed at the tip of the regulating blade 30.
【００３９】[0039]
【発明の効果】以上説明したように、本発明によれば、
現像剤担持体の像担持体と対向した現像部よりも現像剤
担持体の回転方向下流で、かつ現像容器内の位置に配置
された現像剤担持体内磁界発生手段の反撥磁極が、その
反撥磁極間に、現像剤担持体表面の垂直方向の磁束密度
Ｂｒが８０ガウス以下でかつ水平方向の磁束密度Ｂθが
８０ガウス以下である領域を有し、現像剤規制部材の現
像剤担持体との最近接部を、現像剤担持体の鉛直方向最
下点から現像剤担持体の回転方向に９０゜の間の位置に
配置し、かつ現像剤規制部材を、現像剤規制部材の現像
剤担持体の回転方向上流側の面が、現像剤担持体の周方
向上の接線方向に対して現像剤担持体の回転方向に９０
゜〜１８０゜の角度をなすように配設し、さらにその現
像剤規制部材の先端を、現像剤担持体の回転方向上流側
で現像剤担持体に最近接する傾斜形状に形成し、そして
反撥磁極のうちの現像剤担持体の回転方向下流側の磁極
を現像剤規制部材の最近接部の対向位置近傍に配置した
ので、現像剤規制部材の上流側に２成分現像剤が溜まる
のを少なくし、つぎつぎと現像剤が搬送されてくること
による現像剤への圧力を軽減して、現像剤の劣化を防止
でき、また凝集したトナーや異物が規制部につまるのを
防止できる。さらに現像剤担持体を高速回転で使用して
も、現像剤規制部材の先端部でトナーの凝集体が形成さ
れるのを防止することができる。As described above, according to the present invention,
The repelling magnetic poles of the magnetic field generating means in the developer carrier disposed downstream of the developing unit facing the image carrier of the developer carrier in the rotation direction of the developer carrier and at a position in the developing container are the repelling magnetic poles thereof. In between, there is a region where the magnetic flux density Br in the vertical direction on the surface of the developer carrying member is 80 Gauss or less and the magnetic flux density Bθ in the horizontal direction is 80 Gauss or less, The contact portion is disposed at a position between 90 ° in the rotation direction of the developer carrying member from the lowest point in the vertical direction of the developer carrying member, and the developer regulating member is provided on the developer carrying member of the developer regulating member. The surface on the upstream side in the rotational direction is 90 ° in the rotational direction of the developer carrier with respect to the tangential direction in the circumferential direction of the developer carrier.
And a tip of the developer regulating member is formed in an inclined shape closest to the developer carrying member on the upstream side in the rotation direction of the developer carrying member, and a repelling magnetic pole is formed. Since the magnetic pole on the downstream side in the rotation direction of the developer carrying member is arranged near the position opposing the nearest part of the developer regulating member, the accumulation of the two-component developer on the upstream side of the developer regulating member is reduced. The pressure on the developer due to the successive transport of the developer can be reduced, so that the deterioration of the developer can be prevented, and the agglomerated toner and foreign substances can be prevented from clogging the regulating portion. Further, even when the developer carrier is used at a high speed, it is possible to prevent the formation of the toner aggregate at the tip of the developer regulating member.
【００４０】また、非磁性材料の現像剤規制部材の現像
剤担持体回転方向上流側の面に磁性部材を設けたときに
は、規制部における現像剤の密度を低くできるので、現
像剤にかかる負荷をさらに低減して、現像剤の劣化防止
および現像剤規制部材先端部でのトナーの凝集体形成防
止を一段と向上できる。また現像剤規制部材の現像剤担
持体との最近接距離を大きく設定することができるの
で、凝集したトナーや異物の規制部へのつまり防止をさ
らに向上することができる。When the magnetic member is provided on the surface of the non-magnetic material developer regulating member on the upstream side in the direction of rotation of the developer carrier, the density of the developer in the regulating portion can be reduced, so that the load on the developer is reduced. This further reduces the deterioration of the developer and the formation of toner aggregates at the tip of the developer regulating member can be further improved. Further, since the closest distance between the developer regulating member and the developer carrying member can be set large, it is possible to further improve the prevention of agglutinated toner and foreign matter from clogging in the regulating portion.
【図１】本発明の現像装置の一実施例を示す断面図であ
る。FIG. 1 is a sectional view showing one embodiment of a developing device of the present invention.
【図２】図１の現像装置の拡大断面図である。FIG. 2 is an enlarged sectional view of the developing device of FIG.
【図３】本発明の現像装置の他の実施例を示す拡大断面
図である。FIG. 3 is an enlarged sectional view showing another embodiment of the developing device of the present invention.
【図４】従来の現像装置を示す断面図である。FIG. 4 is a cross-sectional view illustrating a conventional developing device.
【図５】従来の現像装置の他の例を示す拡大断面図であ
る。FIG. 5 is an enlarged sectional view showing another example of the conventional developing device.
２ 現像容器 １０ 現像スリーブ １１ マグネットローラ ３０ 規制ブレード ３０ａ 最近接部先端 ３１ 磁性板 １００ 感光ドラム Ｎ２、Ｎ３ 反撥磁極 2 Developing container 10 Developing sleeve 11 Magnet roller 30 Restriction blade 30a Tip end of closest part 31 Magnetic plate 100 Photosensitive drum N2, N3 Repulsive magnetic pole
───────────────────────────────────────────────────── フロントページの続き (51)Int.Cl.7 識別記号 ＦＩ テーマコート゛(参考） Ｈ０１Ｆ 7/02 Ｈ０１Ｆ 1/02 Ａ (72)発明者 長谷川 和弘 東京都大田区下丸子３丁目30番２号 キヤ ノン株式会社内 Ｆターム(参考） 2H031 AC19 AC20 AC31 AC33 AC34 AD11 BA04 2H077 AB02 AB14 AB15 AD06 AD13 AD18 AD24 EA03 FA19 5E040 CA01 HB19 NN13 NN17 ──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. 7 Identification symbol FI Theme coat ゛ (Reference) H01F 7/02 H01F 1/02 A (72) Inventor Kazuhiro Hasegawa 3- 30-2 Shimomaruko, Ota-ku, Tokyo F term in Canon Inc. (reference) 2H031 AC19 AC20 AC31 AC33 AC34 AD11 BA04 2H077 AB02 AB14 AB15 AD06 AD13 AD18 AD24 EA03 FA19 5E040 CA01 HB19 NN13 NN17
Claims (2)
磁界発生手段を内蔵した回転する現像剤担持体上に担持
し、担持された現像剤の層厚を前記現像剤担持体に近接
して設置された現像剤規制部材で規制しながら、像担持
体と対向した現像部へ搬送し、該現像部で現像剤を像担
持体上に形成された静電潜像の現像に供する現像装置に
おいて、 前記磁界発生手段は、前記現像部よりも前記現像剤担持
体の回転方向下流側でかつ現像容器内に位置する第１の
磁極と、該第１の磁極の前記現像剤担持体の回転方向下
流側でかつ前記第１の磁極に隣接して位置する同極性の
第２の磁極とを有し、前記第１の磁極および前記第２の
磁極間には、前記現像剤担持体表面の垂直方向の磁束密
度Ｂｒが８０ガウス以下でかつ水平方向の磁束密度Ｂθ
が８０ガウス以下である領域を有し、前記現像剤担持体
の鉛直方向最下点から前記現像剤担持体の回転方向に９
０゜の間の位置に、前記現像剤規制部材を前記現像剤担
持体と非接触に設置するとともに、前記現像剤規制部材
の前記現像剤担持体の回転方向上流側の面が、前記現像
剤担持体の周方向上の接線方向に対して前記現像剤担持
体の回転方向に９０゜〜１８０゜の角度をなすように、
前記現像剤規制部材を前記現像剤担持体に対して配置
し、さらに前記現像剤規制部材の先端を、前記現像剤担
持体の回転方向上流側で前記現像剤担持体に最近接する
傾斜形状に形成し、そして前記第２の磁極を前記現像剤
規制部材の最近接部の対向位置近傍に配置したことを特
徴とする現像装置。1. A two-component developer stored in a developing container,
The image carrier is supported on a rotating developer carrier having a built-in magnetic field generating means, and the layer thickness of the carried developer is regulated by a developer regulating member provided in proximity to the developer carrier. A developing unit that conveys the developer to the electrostatic latent image formed on the image carrier at the developing unit, wherein the magnetic field generating unit is more than the developing unit. A first magnetic pole located on the downstream side in the rotational direction of the carrier and in the developing container, and a first magnetic pole located on the downstream side in the rotational direction of the developer carrier of the first magnetic pole and adjacent to the first magnetic pole; A second magnetic pole having the same polarity, wherein a magnetic flux density Br in the vertical direction on the surface of the developer carrier is 80 Gauss or less and a magnetic flux in the horizontal direction is provided between the first magnetic pole and the second magnetic pole; Density Bθ
Has an area of 80 gauss or less, and is 9 deg. From the lowest point in the vertical direction of the developer carrier in the rotational direction of the developer carrier.
0 °, the developer regulating member is installed in non-contact with the developer carrier, and the surface of the developer regulating member on the upstream side in the rotation direction of the developer carrier is the developer An angle of 90 ° to 180 ° with respect to a rotational direction of the developer carrier with respect to a tangential direction in a circumferential direction of the carrier,
The developer regulating member is disposed with respect to the developer carrier, and the tip of the developer regulating member is formed in an inclined shape closest to the developer carrier at the upstream side in the rotation direction of the developer carrier. And a second magnetic pole is arranged near a position facing a closest portion of the developer regulating member.
該非磁性部材の先端部であって、前記現像剤担持体の回
転方向上流側の部分に設けられた磁性部材とからなる請
求項１の現像装置。2. The developer regulating member according to claim 1, wherein the non-magnetic member comprises:
The developing device according to claim 1, further comprising a magnetic member provided at a tip portion of the non-magnetic member and on a portion of the developer carrier on the upstream side in the rotation direction.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP11009151A JP2000206792A (en) | 1999-01-18 | 1999-01-18 | Developing device |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP11009151A JP2000206792A (en) | 1999-01-18 | 1999-01-18 | Developing device |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JP2000206792A true JP2000206792A (en) | 2000-07-28 |
Family
ID=11712626
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP11009151A Pending JP2000206792A (en) | 1999-01-18 | 1999-01-18 | Developing device |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP2000206792A (en) |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2007219400A (en) * | 2006-02-20 | 2007-08-30 | Ricoh Printing Systems Ltd | Developer conveyance amount restricting member, developing device, image forming apparatus, and replacing method for development body |
| US7890026B2 (en) | 2007-07-13 | 2011-02-15 | Canon Kabushiki Kaisha | Development apparatus and image forming apparatus |
| JP2011164323A (en) * | 2010-02-09 | 2011-08-25 | Ricoh Co Ltd | Developing device, process cartridge and image forming apparatus |
| US10088776B2 (en) | 2015-10-22 | 2018-10-02 | Ricoh Company, Ltd. | Developing device, and image forming apparatus and process cartridge incorporating same |
-
1999
- 1999-01-18 JP JP11009151A patent/JP2000206792A/en active Pending
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2007219400A (en) * | 2006-02-20 | 2007-08-30 | Ricoh Printing Systems Ltd | Developer conveyance amount restricting member, developing device, image forming apparatus, and replacing method for development body |
| US7890026B2 (en) | 2007-07-13 | 2011-02-15 | Canon Kabushiki Kaisha | Development apparatus and image forming apparatus |
| JP2011164323A (en) * | 2010-02-09 | 2011-08-25 | Ricoh Co Ltd | Developing device, process cartridge and image forming apparatus |
| US10088776B2 (en) | 2015-10-22 | 2018-10-02 | Ricoh Company, Ltd. | Developing device, and image forming apparatus and process cartridge incorporating same |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| JP2003162151A (en) | Developing device and image forming apparatus | |
| US20060045575A1 (en) | Developing device and electrostatic recording device | |
| US5239343A (en) | Developing apparatus with regulating member having magnetic and non-magnetic members | |
| JP2000206792A (en) | Developing device | |
| JP2005352225A (en) | Developing device | |
| JPH1144997A (en) | Developing device | |
| JP2005077540A (en) | Developing device | |
| JP4731218B2 (en) | Development device | |
| JPH06110333A (en) | Magnetic brush developing device | |
| JP2005077538A (en) | Developing device | |
| JPH11161032A (en) | Electrostatic latent image developing device | |
| JP2001034066A (en) | Image forming device and developing device | |
| JP4106678B2 (en) | Development device | |
| JP3636590B2 (en) | Development device | |
| JPH0245866Y2 (en) | ||
| JPH11338259A (en) | Developing device | |
| JP2000250299A (en) | Developing device | |
| JPS59111663A (en) | Electrostatic latent image developing device | |
| JP2003255696A (en) | Developing device and image forming apparatus | |
| JP2000066513A (en) | Developing device and image forming device provided with the same | |
| JP3677443B2 (en) | Development device | |
| JPH06194962A (en) | Developing device | |
| JP2003107909A (en) | Developing device | |
| JP2001005296A (en) | Developing method, developing device and image forming device | |
| JP4139172B2 (en) | Image forming apparatus |