JPS61175664A - Forming device for thin film of developer - Google Patents

Abstract

PURPOSE:To prevent the fogging and white absence of a developed image by circulating magnetic particles and taking a nonmagnetic developer in through the rotation of a circulating upper seal member and securing the triboelectrification of the nonmagnetic developer. CONSTITUTION:The upper seal member 36 is an unmagnetized magnetic member and fixed opposite a magnet blade 24. A magnetic field established between the upper seal member 36 and the magnet blade 24 prevents the magnetic particles 27 from leaking out of a developing container 21 and being conveyed to a development area 32. A circulation magnet 35 is provided at the upstream side of the upper seal member 36 in the rotating direction of the sleeve 22. The magnetic field of the circulation magnet 35 extends to not only magnetic particles contacting a developing sleeve 22, but also magnetic particles outside it, so the force of circulation extends to the whole of the magnetic particle layer with the force of the magnetic field, thereby stabilizing the circulation stably.

Description

【発明の詳細な説明】 １糺±」 本発明は乾式現像剤の薄層形成装置に関する。[Detailed description of the invention] 1 纺±” The present invention relates to an apparatus for forming a thin layer of dry developer.

更には、非磁性現像剤の薄層形成装置に関する。The present invention further relates to a thin layer forming device for non-magnetic developer.

賢」」Ｌｌ 従来、乾式−成分現像装置としては各種装置が提案され
また実用化されている。しかし、いずれの現像方式にお
いても乾式−成分現像剤の薄層を形成することは、極め
て難しく、このため比較的厚い層の形成で現像装置を構
成していた。しかるに現像画像の鮮明度、解像力、など
の向上が求められている現在、乾式−成分現像剤の薄層
形成方法およびその装置に関する開発は必須となってい
る。Hitherto, various devices have been proposed and put into practical use as dry-component developing devices. However, in any of the development methods, it is extremely difficult to form a thin layer of dry-component developer, and for this reason, a developing device has been constructed by forming a relatively thick layer. However, as improvements in the clarity, resolution, etc. of developed images are currently being sought, it is essential to develop a method for forming a thin layer of a dry component developer and an apparatus therefor.

従来知られている乾式−成分現像剤の薄層を形成する方
法としては、特開昭５４−４３０３７号が提案されてお
り、且つ実用化されている。しかし、これは磁性現像剤
の薄層形成に関するものであった。磁性現像剤は磁性を
持たせるため磁性体を内添しなければならず、これは転
写紙に転写した現像像を熱定着する際の定着性の悪さ、
現像剤自身に磁性体（磁性体は通常黒色である）を内添
するためにカラー再現の際の色彩の悪いこと等の問題点
がある。As a method of forming a thin layer of a conventionally known dry component developer, Japanese Patent Application Laid-Open No. 54-43037 has been proposed and has been put into practical use. However, this concerned the formation of a thin layer of magnetic developer. In order to make magnetic developers magnetic, a magnetic material must be added inside them, which causes poor fixing properties when heat fixing the developed image transferred to transfer paper.
Since the developer itself contains a magnetic material (the magnetic material is usually black in color), there are problems such as poor color reproduction during color reproduction.

このため非磁性現像剤の薄層形成方法として、ビーバー
の毛のような柔らかい毛を円筒状のブラシにして、これ
に現像剤を付着塗布する方法や、表面がベルベット等の
繊維で作られた現像ローラにドクターブレード等により
塗布する方法が提案されている。しかしながら上記繊維
ブラシにドクターブレードとして弾性体ブレードを使用
した場合、現像剤量の規制は可能であるが、均一な塗布
は行われず、現像ローラ上の繊維ブラシを摺擦するだけ
で、ブラシの繊維間に存在する現像剤への摩擦帯電電荷
賦与は行なわれないため、かぶり等の発生しやすいとい
う問題点があった。また、非磁性現像剤を有しているの
で、装置か°らの現像剤の漏れを防止することが難しか
った。For this reason, as a method for forming a thin layer of non-magnetic developer, there are two methods: using a cylindrical brush made of soft bristles like beaver's hair, and applying the developer to the brush. A method of coating the developing roller with a doctor blade or the like has been proposed. However, when an elastic blade is used as a doctor blade for the above-mentioned fiber brush, it is possible to regulate the amount of developer, but uniform application is not achieved, and the fibers of the brush are simply rubbed by the fiber brush on the developing roller. Since no triboelectric charge is imparted to the developer present in between, there is a problem in that fogging and the like are likely to occur. Furthermore, since the device includes a non-magnetic developer, it is difficult to prevent the developer from leaking from the device.

ｌ見立１道 上述の従来方法と全く異なる新規な薄層形成方法として
、現像剤保持部材の表面の移動方向に関し、磁性粒子拘
束部材の上流側に磁性粒子による磁気ブラシを形成し、
この磁気ブラシにより非磁性現像剤の薄層を現像剤保持
部材上に形成する方法が既に提案されている、しかし乍
ら、この現像装置においては、容器内で磁性粒子が十分
に循環していないと、現像剤が磁性粒子層へ充分に補給
されない為、現像剤保持部材上に形成される薄層にムラ
が生じ、それによって現像ムラが生じる。As a new thin layer forming method that is completely different from the conventional method described above, a magnetic brush made of magnetic particles is formed on the upstream side of the magnetic particle restraining member with respect to the moving direction of the surface of the developer holding member.
A method has already been proposed in which a thin layer of non-magnetic developer is formed on a developer holding member using this magnetic brush. However, in this developing device, magnetic particles are not sufficiently circulated within the container. Since the developer is not sufficiently replenished to the magnetic particle layer, unevenness occurs in the thin layer formed on the developer holding member, thereby causing uneven development.

又１画像形成装置本体からの振動等によって、磁性粒子
の循環が阻害され、磁性粒子の循環が不充分になったり
、あるいは停止した際には、現像剤保持部材上に保持さ
れる現像剤の摩擦による帯電量が上昇し、通常の現像バ
イアスを印加しても像担持体への現像剤が飛翔せず、現
像できないといった不都合（いわゆる白抜け）を生じる
場合もある。In addition, when the circulation of magnetic particles is inhibited by vibrations from the main body of the image forming apparatus, and the circulation of magnetic particles becomes insufficient or stops, the amount of developer held on the developer holding member The amount of electrification due to friction increases, and even if a normal developing bias is applied, the developer does not fly to the image carrier, which may cause problems such as inability to develop (so-called white spots).

従って、本発明は容器内に拘束された、磁性粒子を使用
して、現像剤保持部材上に非磁性現像剤の薄層を形成す
る装置において、磁性粒子が容器内で長期にわたって安
定に十分循環する現像剤薄層形成装置を提供することを
目的とする。Therefore, the present invention provides an apparatus for forming a thin layer of non-magnetic developer on a developer holding member using magnetic particles confined within a container, in which the magnetic particles are stably and sufficiently circulated within the container over a long period of time. An object of the present invention is to provide a developer thin layer forming device.

産」ＬΩＪＪ 本発明によれば開口を有する現像剤供給容器と、該開口
に設けられ、前記容器の内部と外部を無端移動可能な現
像剤保持用非磁性部材と、該保持部材内部に設けられた
磁性部材および固定磁界発生手段と、前記現像剤保持部
材の外側に設けられ、前記磁性部材および前記固定磁界
発生手段とともに前記磁性粒子層を現像剤供給容器内部
に拘束する磁石部材と、前記保持部材内部に設けられ１
回転可能な磁界発生手段を有する現像剤薄層形成装置が
提供されるので、磁性粒子の安定な循環が確保される。According to the present invention, there is provided a developer supply container having an opening, a developer holding non-magnetic member provided in the opening and movable endlessly between the inside and outside of the container, and a developer holding non-magnetic member provided inside the holding member. a magnetic member and a fixed magnetic field generating means; a magnet member provided outside the developer holding member and restraining the magnetic particle layer inside the developer supply container together with the magnetic member and the fixed magnetic field generating means; Provided inside the member 1
Since a developer thin layer forming device is provided with rotatable magnetic field generating means, stable circulation of the magnetic particles is ensured.

支ム１ 以下本発明の実施例を図面とともに説明する。Support 1 Embodiments of the present invention will be described below with reference to the drawings.

第１図は本出願人による特願昭５８−２０５１８９に記
載の現像剤薄層形成装置の断面図である。この現像剤薄
層形成装置は、現像剤保持部材の表面の移動方向に関し
、磁性粒子拘束部材の上流側に磁性粒子による磁気ブラ
シを形成し、この磁気ブラシにより非磁性現像剤の薄層
を現像剤保持部材に形成するものである。FIG. 1 is a sectional view of a developer thin layer forming apparatus described in Japanese Patent Application No. 58-205189 filed by the present applicant. This developer thin layer forming device forms a magnetic brush made of magnetic particles on the upstream side of a magnetic particle restraining member with respect to the moving direction of the surface of the developer holding member, and develops a thin layer of non-magnetic developer with this magnetic brush. It is formed on the agent holding member.

第１図の装置は、現像剤供給容器２１、現像剤保持部材
としての現像スリーブ２２を有する。現像スリーブ２２
は例えばアルミニウム等の非磁性スリーブであり、現像
剤供給容器２１の左側壁の下部に容器長手方向に形成し
た横長開口に、右略半周面を容器２１内へ突入させ、左
略半周面を容器外へ露出させて回転自由に軸受させて横
設してあり、矢示の反時計方向すに回転駆動される。現
像剤保持部材２２は上記円筒体（スリーブ）に限らず、
回動駆動される無端ベルト形態等にしてもよい、該現像
スリーブ２２の容器外露出面は、矢示ａ方向に面移動駆
動されている感光体等の潜像保持部材３面に借手な隙間
を存して対面している。The apparatus shown in FIG. 1 includes a developer supply container 21 and a developing sleeve 22 as a developer holding member. Developing sleeve 22
is a non-magnetic sleeve made of aluminum or the like, and its right half circumferential surface extends into the container 21 into a horizontally elongated opening formed in the lower part of the left side wall of the developer supply container 21 in the longitudinal direction of the container, and its left half circumferential surface extends into the container 21. It is mounted horizontally on a bearing that is exposed to the outside and can freely rotate, and is driven to rotate counterclockwise as shown by the arrow. The developer holding member 22 is not limited to the above-mentioned cylindrical body (sleeve).
The exposed surface of the developing sleeve 22 outside the container, which may be in the form of an endless belt that is rotationally driven, is provided with a gap between the surface of the latent image holding member 3 such as a photoreceptor that is driven to move in the direction of arrow a. We are facing each other in the same way.

現像スリーブ２２内には磁石（マグネット）２３が設け
られ、これは図示の位置・姿勢に位置決め保持した固定
磁界発生手段としての固定の永久磁石（マグネット）で
あり、現像スリーブ２２が回転駆動されてもこの磁石２
３は図示の位置−姿勢にそのまま固定保持される。この
磁石２３はＮ極２３ａ、Ｓ極２３ｂの磁極を有する。磁
石２３としては永久磁石に代えて電磁石を配設してもよ
い。A magnet 23 is provided inside the developing sleeve 22, and this is a fixed permanent magnet (magnet) as a fixed magnetic field generating means that is positioned and held in the illustrated position and orientation, and when the developing sleeve 22 is rotationally driven. Moko's magnet 2
3 is fixedly held in the illustrated position and posture. This magnet 23 has a north pole 23a and a south pole 23b. As the magnet 23, an electromagnet may be provided instead of a permanent magnet.

現像スリーブ２２を配設した現像剤供給容器開口の上縁
側には磁性粒子拘束部材としての磁石ブレード２４が設
けられ５これは基部を容器側壁に固定され、先端側は開
口上縁位置よりも容器２１の内方へ突入させて開口上級
長手に沿って配設されており、例えば鋼板を横断簡略く
の字形に曲げ加工した後着磁したものである。A magnet blade 24 as a magnetic particle restraining member is provided on the upper edge side of the opening of the developer supply container in which the developing sleeve 22 is disposed. 21, and is arranged along the upper longitudinal direction of the opening, for example, by bending a steel plate into a simple cross-sectional shape and then magnetizing it.

磁性粒子循環域限定部材２６が磁石ブレード２４の上面
側に下面を接触させて設けられ、その前端面２６ａはア
ンダカットされている。A magnetic particle circulation area limiting member 26 is provided with its lower surface in contact with the upper surface of the magnet blade 24, and its front end surface 26a is undercut.

２７・２８は現像剤供給容器ｚｌ内に順次に収容した磁
性粒子と非磁性現像剤である。Reference numerals 27 and 28 denote magnetic particles and non-magnetic developer which were sequentially accommodated in the developer supply container zl.

現像剤供給容器２１の底板は、現像剤保持部材たる現像
スリーブ２２の下方に延長位置させて現像剤が外部に漏
れないようにしである。またこの現像剤の外部への漏出
の防止をさらに確実ならしめるためにその延長底板２１
ａの上面に、漏出現像剤を受は入れて拘束する漏出現像
剤捕集容器部２９と、延長底板２１ａの先端縁長手に沿
って飛散防止部材３０を配設しである。The bottom plate of the developer supply container 21 is extended below the developing sleeve 22, which is a developer holding member, to prevent the developer from leaking to the outside. Further, in order to further ensure the prevention of leakage of this developer to the outside, the extension bottom plate 21 is
A leaked developer collecting container 29 for receiving and restraining leaked developer is disposed on the top surface of the container 21a, and a scattering prevention member 30 is disposed along the length of the distal end edge of the extended bottom plate 21a.

磁性粒子２７は粒径が３０〜２００ｐＬ、好ましくは７
０〜１５０用である。各磁性粒子は磁性材料のみから成
るものでも、磁性材料と非磁性材料との結合体でもよい
し、二種以上の磁性粒子の混合物でも良い、そしてこの
磁性粒子２７を先ずはじめに現像剤供給容器２１内に投
入することにより、その磁性粒子２７が容器２１内に臨
んでいるスリーブ面領域、即ちスリーブ２２を配設した
現像剤供給容器２１からの磁性粒子ないしは現像剤の漏
出を防止するための磁性部材３１から磁性粒子拘束部材
たる磁石ブレード２４の先端部までのスリーブ面慴域各
部に、スリーブ２２内の磁石２３による磁界により吸着
保持され、磁性粒子層として該スリーブ面領域を全体的
に覆った状態となる。非磁性現像剤２８は上記磁性粒子
２．７の投入後容器２１内に投入されることにより、上
記スリーブ２２に対する第１層としての磁性粒子層の外
側に多量に貯溜して第２層として存在する。The magnetic particles 27 have a particle size of 30 to 200 pL, preferably 7
It is for 0-150. Each magnetic particle may be made of only a magnetic material, a combination of a magnetic material and a non-magnetic material, or a mixture of two or more types of magnetic particles. By placing the magnetic particles 27 inside the container 21, the magnetic particles 27 are placed inside the sleeve surface area facing the inside of the container 21, that is, the magnetic particles or the developer are prevented from leaking from the developer supply container 21 in which the sleeve 22 is disposed. Each part of the sleeve surface area from the member 31 to the tip of the magnet blade 24, which is a magnetic particle restraining member, was attracted and held by the magnetic field of the magnet 23 in the sleeve 22, and the magnetic particle layer completely covered the sleeve surface area. state. When the non-magnetic developer 28 is put into the container 21 after the magnetic particles 2.7 are put in, a large amount of the non-magnetic developer 28 is stored outside the magnetic particle layer as the first layer with respect to the sleeve 22 and exists as a second layer. do.

上記最初に投入する磁性粒子２７は、磁性粒子に対して
もともと約２〜７０％（重量）の非磁性現像剤２８を含
むことが好ましいが、磁性粒子のみとしても良い、また
磁性粒子２７は一旦上記スリーブ面領域に磁性粒子層と
して吸着保持されれば、装置振動や、装置をかなり大き
く傾けても実質的に片寄り流動してしまうことはなく、
上記スリーブ面領域を全体的に覆った状態が保持される
。It is preferable that the magnetic particles 27 initially introduced above originally contain about 2 to 70% (by weight) of the non-magnetic developer 28 based on the magnetic particles, but it is also possible to use only magnetic particles. If the magnetic particles are adsorbed and held in the sleeve surface area as a layer, there will be no substantial unbalanced flow even if the device is vibrated or the device is tilted considerably.
The sleeve surface area is kept completely covered.

而して容器２１内に上記のように磁性粒子２７と非磁性
現像剤２８を順次に投入収容した状態に於て、磁石２３
の磁極２３ａ位置に対応するスリーブ表面付近の磁性粒
子層部分には磁極２３ａの強い磁界で磁性粒子の磁気ブ
ラシ２７ａが形成される。When the magnetic particles 27 and the non-magnetic developer 28 are sequentially placed in the container 21 as described above, the magnet 23
A magnetic brush 27a of magnetic particles is formed in a portion of the magnetic particle layer near the sleeve surface corresponding to the position of the magnetic pole 23a by the strong magnetic field of the magnetic pole 23a.

また磁性粒子拘束部材たる磁石ブレード２４の先端部近
傍部の磁性粒子層部分は、スリーブ２２が矢示す方向に
回転駆動されても、重力、磁気力および磁石ブレード２
４の存在による効果に基づく拘束力と、スリーブ２２の
移動方向への搬送力との釣合によってスリーブ２２表面
の点２５位置で拘束され、多少は動き得るが殆ど不動の
静止層２７ｂを形成する。Furthermore, even when the sleeve 22 is rotated in the direction indicated by the arrow, the magnetic particle layer near the tip of the magnet blade 24, which is a magnetic particle restraining member, is affected by gravity, magnetic force, and the magnetic particle layer 24.
Due to the balance between the restraint force based on the effect of the presence of 4 and the conveyance force in the moving direction of the sleeve 22, the sleeve 22 is restrained at the point 25 on the surface thereof, forming a stationary layer 27b that can move to some extent but is almost immobile. .

またスリーブ２２を矢示す方向に回転させた時、磁極２
４の配置位置と磁性粒子２７の流動性および磁気特性を
適宜選ぶことによって、前記磁気ブラシ２７ａは磁極２
３ａの付近で矢印Ｃ方向に循環し、循環層２７ｃを形成
する。該循環層２７ｃにおいて、スリーブ２２に比較的
近い磁性粒子分はスリーブ２２の回転によって磁極２３
ａ近傍からスリーブの回転下流側にある前記の静止層２
７ｂの上へ盛り上る。すなわち上部へ押し上げる力を受
ける。その押し上げられた磁性粒子分は、磁石ブレード
２４の上部に設けた磁性粒子循環域限定部材２６により
、その循環領域の上限を決められているため、磁石ブレ
ード２４上へ乗り上がることはなく、重力によって落下
し、２再び磁極２３ａ近傍へ戻る。この場合スリーブ表
面から遠くに位置するなどして受ける押し上げ力の小さ
い磁性粒子分は、磁性粒子循環域限定部材２６に到達す
る前に落下する場合もある。つまり該循環層２７ｃでは
重力と磁極による磁気力と摩擦力および磁性粒子の流動
性（粘性）によって矢印Ｃの如く磁性粒子の磁気ブラシ
２７ａの循環が行われ、磁気ブラシはこの循環の際に磁
性粒子層の上にある現像剤層から非磁性現像剤２８を逐
次取込んで現像剤供給容器２１内の下部に戻り、以下ス
リーブ２２の回転駆動に伴ないこの１環を繰返す、磁石
ブレード２４は直接にはこの循環には関与しない。Also, when the sleeve 22 is rotated in the direction shown by the arrow, the magnetic pole 2
4 and the fluidity and magnetic properties of the magnetic particles 27, the magnetic brush 27a can be set to the magnetic pole 2.
3a, it circulates in the direction of arrow C, forming a circulation layer 27c. In the circulation layer 27c, the magnetic particles relatively close to the sleeve 22 are moved to the magnetic pole 23 by the rotation of the sleeve 22.
The stationary layer 2 located on the rotationally downstream side of the sleeve from the vicinity of a
It rises to the top of 7b. In other words, it receives a force that pushes it upward. Since the upper limit of the circulation area of the pushed-up magnetic particles is determined by the magnetic particle circulation area limiting member 26 provided on the upper part of the magnet blade 24, the magnetic particles do not climb onto the magnet blade 24 and are 2, and returns to the vicinity of the magnetic pole 23a again. In this case, magnetic particles that are located far from the sleeve surface and receive a small push-up force may fall before reaching the magnetic particle circulation area limiting member 26. In other words, in the circulation layer 27c, the magnetic brush 27a of magnetic particles is circulated as shown by arrow C due to the magnetic force and frictional force due to gravity and magnetic poles, and the fluidity (viscosity) of the magnetic particles, and during this circulation, the magnetic brush 27a is made of magnetic particles. The magnetic blade 24 sequentially takes in the non-magnetic developer 28 from the developer layer above the particle layer, returns to the lower part of the developer supply container 21, and repeats this cycle as the sleeve 22 is rotated. It is not directly involved in this cycle.

スリーブ２２面の磁性粒子層内に逐次に取込まれ混入し
た非磁性現像剤は、磁性粒子の流動で磁性粒子との摩擦
、現像スリーブ面との摩擦等で帯電する。この場合、好
ましくは磁性粒子表面に酸化膜または非磁性現像剤と静
電的に同準位にある樹脂などの絶縁処理を施し、磁性粒
子からのトリポ付与を少なくし、必要な帯電を現像スリ
ーブ２２から受けるようにすれば、磁性粒子の劣化の影
響を防ぐことができるとともに、現像スリーブ２２への
現像剤塗布が安定する。この帯電現像剤は非磁性である
ため、磁極２４の磁界によっては拘束されず、スリーブ
面がスリーブ２２を配設した容器開口下縁の磁性部材３
１の所から磁石ブレード２４の先端部まで回転移動する
間に、鏡映力によってスリーブ表面に各部均一に薄くコ
ーティングされる。The non-magnetic developer that is successively taken in and mixed into the magnetic particle layer on the surface of the sleeve 22 is charged by friction with the magnetic particles due to the flow of the magnetic particles, friction with the surface of the developing sleeve, etc. In this case, it is preferable to apply an insulating treatment such as an oxide film or a resin that is electrostatically at the same level as the non-magnetic developer to the surface of the magnetic particles, to reduce the transfer of tripod from the magnetic particles, and to transfer the necessary charge to the developing sleeve. By applying the developer to the developing sleeve 22, it is possible to prevent the influence of deterioration of the magnetic particles, and the application of the developer to the developing sleeve 22 is stabilized. Since this charged developer is non-magnetic, it is not restrained by the magnetic field of the magnetic pole 24, and the sleeve surface is the magnetic member 3 at the lower edge of the container opening where the sleeve 22 is disposed.
During rotational movement from the point 1 to the tip of the magnet blade 24, the surface of the sleeve is uniformly and thinly coated at each part due to the mirroring force.

そして磁石ブレード２４の先端部近傍の磁性粒子静止層
２７ｂの磁性粒子は、スリーブ２２が回転していても前
述したように重力と磁気力および磁石ブレード２４の存
在による効果に基づく拘束力と、スリーブ２２の移動方
向への搬送力との釣合いによって拘束されて、磁石ブレ
ード２４の先端部とスリーブ２２との隙間部ｄを通過せ
ず、スリーブ２２面に形成された上記非磁性現像剤のコ
ーティング薄層のみが、スリーブ２２０回転に伴ない隙
間部ｄを通過して潜像保持体３側に回動搬送され、該潜
像保持体面に接近対面する。２８ａは現像スリーブ２２
面に形成された非磁性現像剤のコーティング薄層を示す
、また上記非磁性現像剤の薄層を形成した現像スリーブ
２２と潜像担持体１１との接近対面部を現像部３２と称
す。Even when the sleeve 22 is rotating, the magnetic particles in the magnetic particle stationary layer 27b near the tip of the magnet blade 24 are affected by the binding force based on the effects of gravity, magnetic force, and the presence of the magnet blade 24, as described above, and the sleeve 22. The thin coating of the non-magnetic developer formed on the surface of the sleeve 22 does not pass through the gap d between the tip of the magnet blade 24 and the sleeve 22 due to the balance with the conveyance force in the moving direction of the magnet blade 22. As the sleeve 220 rotates, only the layer passes through the gap d and is rotatably conveyed to the latent image holding body 3 side, and comes close to facing the surface of the latent image holding body. 28a is the developing sleeve 22
A thin coating layer of non-magnetic developer formed on the surface of the developing sleeve 22 and a close facing portion of the latent image carrier 11 on which the thin layer of non-magnetic developer is formed is referred to as a developing section 32.

尚、図中の３３はスリーブ２２の長手方向の両端部に設
けられた現像剤阻止部材で、スリーブ両端部での非磁性
現像剤の塗布を阻止している。Incidentally, reference numeral 33 in the figure denotes a developer blocking member provided at both ends of the sleeve 22 in the longitudinal direction, and prevents the non-magnetic developer from being applied to both ends of the sleeve.

現像部３２に於て、現像スリーブ２２面側の非磁性現像
剤層２８ａは、潜像保持体３と現像スリーブ２２の間に
バイアス電源３４で交流に直流を重畳した電圧を印加し
た現像バイアスの電界によって、潜像保持体３面へ潜像
パターンに対応して選択的に移行付着し潜像の現像が順
次に行われる（この現像方法については例えば特公昭５
８−３２３７５号公報参照）、バイアス電源３４は交流
でも直流でもよい。In the developing section 32, the non-magnetic developer layer 28a on the surface side of the developing sleeve 22 is coated with a developing bias voltage obtained by applying a voltage in which alternating current and direct current are superimposed by a bias power source 34 between the latent image holder 3 and the developing sleeve 22. The electric field selectively transfers and adheres to the three surfaces of the latent image carrier in accordance with the latent image pattern, and the latent images are sequentially developed (this developing method is described in, for example,
8-32375), the bias power supply 34 may be an alternating current or a direct current.

現像部３２を通過して現像剤層が選択的に現像に共され
て消費された現像スリーブ面は引続くスリーブの回転駆
動で再び現像剤供給容器２１内へ戻り、あらためて磁性
粒子層と接触し、その層内に含有されている非磁性現像
剤のコーティングを受けるサイクルが繰り返され、潜像
保持部材３面の現像が連続的に実行される。磁性粒子層
へは前記したように磁性粒子の循環層２７ｃによりその
外側に存在する非磁性現像剤２８の貯溜層から逐次現像
剤が取込まれて自然補給される。尚、現像スリーブの所
謂ゴースト像現象を防止するために、容器２１内へ戻り
回動した現像スリーブ面から現像に供されなかった現像
剤層を−Ｈスクレーバ手段（不図示）でかき落し、その
現像剤層かき落しスリーブ面を磁性粒子層に接触させて
現像剤のコーティングを行なわせるようにするのもよい
。The surface of the developing sleeve that has passed through the developing section 32 and been consumed as the developer layer is selectively developed is returned to the developer supply container 21 by the subsequent rotational drive of the sleeve, and comes into contact with the magnetic particle layer again. The cycle of being coated with the non-magnetic developer contained in the layer is repeated, and the surface of the latent image holding member 3 is continuously developed. As described above, the magnetic particle layer is naturally replenished by successively taking in developer from the non-magnetic developer 28 storage layer located outside of the magnetic particle circulation layer 27c. In order to prevent the so-called ghost image phenomenon of the developing sleeve, the developer layer that has not been subjected to development is scraped off from the surface of the developing sleeve that has been rotated back into the container 21 using a -H scraper means (not shown). It is also preferable to bring the developer layer scraping sleeve surface into contact with the magnetic particle layer so that the developer is coated.

非磁性現像剤２８には、流動性を高めるためにシリカ粒
子や、例えば転写方式画像形成方式に於て潜像保持部材
３たる感光体表面の研磨のために研磨剤粒子等を外添し
てもよい、また非磁性現像剤２８中に少量の磁性粒子を
加えたものを用いてもよい。The non-magnetic developer 28 may be externally supplemented with silica particles to increase fluidity, or abrasive particles to polish the surface of the photoreceptor, which is the latent image holding member 3, in a transfer image forming system, for example. Alternatively, a non-magnetic developer 28 containing a small amount of magnetic particles may be used.

上記の構成において、はぼ満足できる現、像剤薄層形成
装置が得られる。しかしながら、長期間にわたって使用
した際に現像装置が画像形成装置本体より受ける機械的
振動、または画像のカラー化に伴なって、現像装置の交
換動作の際に起こる振動・衝撃等によって循環ｙ＃２７
　ｃの循環が悪化することがある。前記したように、磁
性粒子の循環層２７ｃによりその外側に存在する非磁性
現像剤２８が磁性粒子層に取り込まれて自然補給がなさ
れる。したがって、循環層２７ｃの循環が悪化すれば、
磁性粒子層への非磁性現像剤２８の補給が滞り、現像ス
リーブ２２上に形成される非磁性現像剤２８の薄層の厚
さにムラを生じ、その結実現像像の濃度ムラを生じてし
まう、また、上述の如く現像装置への外部からの機械的
振動により循環層２７ｃの循環が阻害される。あるいは
、極端な場合として、停止した際には、現像スリーブ２
２上に薄層化された非磁性現像剤２２の摩擦帯電量が上
昇し、いわゆる自抜けを生じる等の不都合がある。With the above configuration, a highly satisfactory developing and developing agent thin layer forming apparatus is obtained. However, when the developing device is used for a long period of time, the mechanical vibrations that the developing device receives from the main body of the image forming apparatus, or the vibrations and shocks that occur when replacing the developing device due to the colorization of images, cause circulation.
c circulation may worsen. As described above, the non-magnetic developer 28 present outside the circulating layer 27c of magnetic particles is taken into the magnetic particle layer and naturally replenished. Therefore, if the circulation in the circulation layer 27c deteriorates,
Replenishment of the non-magnetic developer 28 to the magnetic particle layer is delayed, causing uneven thickness of the thin layer of the non-magnetic developer 28 formed on the developing sleeve 22, resulting in uneven density of the formed image. Further, as described above, the circulation of the circulation layer 27c is inhibited by external mechanical vibrations applied to the developing device. Or, in an extreme case, when it stops, the developing sleeve 2
The amount of triboelectric charge of the non-magnetic developer 22 formed in a thin layer on the developer 2 increases, causing problems such as so-called self-pulling.

第２図は、この不都合を解決する本発明の実施例の現像
剤薄層形成装置の断面図である。上部シール部材３６は
非着磁の磁性部材で、磁石ブレード２４と対向する位置
に固定されている。磁石ブレード２４に対向する磁極は
、４００Ｇ程度の強さで、本実施例ではＳ極であるが、
Ｎ極としても良い、この上部シール部材３６と磁石ブレ
ード２４との間に形成される磁界により、磁性粒子２７
が現像容器２１の外側へ漏れて現像領域３２へ搬送され
ることを防止している。FIG. 2 is a sectional view of a developer thin layer forming apparatus according to an embodiment of the present invention that solves this problem. The upper seal member 36 is a non-magnetized magnetic member and is fixed at a position facing the magnet blade 24. The magnetic pole facing the magnet blade 24 has a strength of about 400G, and is an S pole in this embodiment.
Due to the magnetic field formed between the upper sealing member 36 and the magnet blade 24, which may be a north pole, the magnetic particles 27
This prevents the liquid from leaking to the outside of the developing container 21 and being transported to the developing area 32.

スリーブ２２の回転方向で上部シール部材３６の上流に
は循環マグネット３５が設けられる。より詳細には、循
環マグネット３５は磁性粒子２７が循環する領域（磁石
ブレード２４と下部シール用の磁性部材３１との間に挾
まれた領域）近傍の現像スリーブ２２内に設けられる。A circulation magnet 35 is provided upstream of the upper seal member 36 in the direction of rotation of the sleeve 22 . More specifically, the circulation magnet 35 is provided in the developing sleeve 22 near the area where the magnetic particles 27 circulate (the area sandwiched between the magnet blade 24 and the lower sealing magnetic member 31).

循環マグネ−。Circulation magne.

トは回転可能で複数磁極を有するマグネットであり、本
実施例ではマグネットローラであり、矢印ｄの方向に回
動する。マグネットローラ３５は同方向に交互に配列さ
れた磁極を有する。磁性粒子２７は、循環マグネット３
５が矢印ｄの方向に回転することにより、矢印Ｃの方向
に循環する。したがって、磁性粒子２７は現像スリーブ
２２どの摩擦力により矢印Ｃの方向に動く力を受け、か
つ循環マグネット３５が矢印ｄの方向に回転することに
より、同じく矢印Ｃの方向へ動く力を同時に受けること
になる０本発明を用いない第１図に示す構成においては
、現像スリーブ２２の矢印すの回転により生じる摩擦力
のみで、磁性粒子２７を循環させる。したがって、直接
的な循環力は現像スリーブ２２に接している磁性粒子２
７にしか及ばない為に、磁性粒子層の循環が不安定にな
り易い、これに比して、第２図における本発明の実施例
によれば、循環マグネット３５の磁界は現像スリーブ２
２に接している磁性粒子のみならず、その外側の磁性粒
子にも届くので、この磁界の及ぼす力により、磁性粒子
層全体に循環の力が及び、非常に循環が安定となる。d is a rotatable magnet having a plurality of magnetic poles, which in this embodiment is a magnetic roller, and rotates in the direction of arrow d. The magnet roller 35 has magnetic poles arranged alternately in the same direction. The magnetic particles 27 are connected to the circulating magnet 3
5 rotates in the direction of arrow d, thereby circulating in the direction of arrow C. Therefore, the magnetic particles 27 receive a force to move in the direction of arrow C due to the frictional force of the developing sleeve 22, and simultaneously receive a force to move in the direction of arrow C as the circulating magnet 35 rotates in the direction of arrow d. In the configuration shown in FIG. 1 which does not use the present invention, the magnetic particles 27 are circulated only by the frictional force generated by the rotation of the developing sleeve 22 in the direction of the arrow. Therefore, the direct circulating force is applied to the magnetic particles 2 in contact with the developing sleeve 22.
7, the circulation of the magnetic particle layer tends to become unstable.In contrast, according to the embodiment of the present invention shown in FIG.
Since the magnetic field reaches not only the magnetic particles in contact with 2 but also the magnetic particles on the outside thereof, the force exerted by this magnetic field applies a circulation force to the entire magnetic particle layer, making the circulation extremely stable.

尚、第２図に於て、循環マグネット３５はＮ−３交互の
４極構成としたが、極数は？極でも、４極以上でもよい
、磁極の大きさとしては、、　４００〜８００Ｇ程度が
望ましい、また、循環マグネットの回転速度はスリーブ
速度の１．５〜３倍程度が好ましい。In Fig. 2, the circulating magnet 35 has a four-pole structure with N-3 alternating, but what is the number of poles? The size of the magnetic poles, which may be poles or 4 or more, is preferably about 400 to 800G, and the rotational speed of the circulation magnet is preferably about 1.5 to 3 times the sleeve speed.

第３図は本発明の他の実施例を示す。FIG. 3 shows another embodiment of the invention.

＃２［１ｉｆｆの実施例においては、現像スリーブ２２
と循環マグネト３５を外部より別々に駆動していたが、
この構成によると、駆動部が複雑化、大型化する。そこ
で１本実施例では、外部からの駆動は現像スリーブ２２
に対するものとし、循環マグネット３５は現像スリーブ
２２内にて現像スリーブ２２に従動する構成とするもの
である。#2 [In the 1iff embodiment, the developing sleeve 22
and the circulating magnet 35 were driven separately from the outside,
According to this configuration, the drive section becomes complicated and large. Therefore, in this embodiment, the external drive is for the developing sleeve 22.
In contrast, the circulation magnet 35 is configured to follow the developing sleeve 22 within the developing sleeve 22.

現像スリーブ２２の内部には内歯歯車が形成され、循環
磁石３５の外側にも歯車が形成され、これら両方の歯に
歯車３７が嵌合する。歯車３７の軸は本体に取付けられ
ている。An internal gear is formed inside the developing sleeve 22, and a gear is formed outside the circulation magnet 35, and a gear 37 is fitted into both teeth. The shaft of the gear 37 is attached to the main body.

第３図に於て、現像スリーブ２２を不図示の外部駆動機
構により矢印す方向に回転させると、ギアは３７は矢印
ｅの方向に回転し、循環上部シール部材３６は矢印ｄの
方向に回転する。このように、スリーブ２２に中間歯車
を設けることにょリ、駆動系を太きくすることなく、循
環上部シール部材３６を回転させることが可能である。In FIG. 3, when the developing sleeve 22 is rotated in the direction of the arrow by an external drive mechanism (not shown), the gear 37 rotates in the direction of the arrow e, and the circulation upper seal member 36 rotates in the direction of the arrow d. do. In this manner, by providing the intermediate gear on the sleeve 22, it is possible to rotate the circulation upper seal member 36 without increasing the size of the drive system.

すなわち、現像スリーブ２２の内面に歯車３７および３
５があり、ギヤ系はすべてスリーブ２２の内部に収まり
、奥行方向に特にギヤ列を特に設ける必要がなく駆動系
が太きくならない。That is, gears 37 and 3 are provided on the inner surface of the developing sleeve 22.
5, the gear system is all housed inside the sleeve 22, there is no need to provide a gear train in the depth direction, and the drive system does not become thick.

免１立皇Ｊ 以上説明したように、本発明によれば、循環上部シール
部材３６の回転により、磁性粒子の循環および非磁性現
像剤の取込みが十分に行なわれ、しかも、非磁性現像剤
に対するトリポ帯電を確実ならしめるので現像像のかぶ
りや白抜けが生ずることがない。As explained above, according to the present invention, by rotating the circulation upper seal member 36, magnetic particles are sufficiently circulated and non-magnetic developer is taken in. Since tripo charging is ensured, there will be no fogging or white spots in the developed image.

【図面の簡単な説明】[Brief explanation of drawings]

第１図は１本発明を用いない現像剤薄層形成装置の断面
図。 第２図は１本発明の実施例による、現像剤薄層形成装置
の断面図、 第３図は、本発明の他の実施例による現像剤薄層形成装
置の現像スリーブ近傍の拡大図。 征」ＬΩ」Ｌ男 ３−・・感光ドラム、２４・・嘩磁性粒子拘束部材、２
２・・・現像剤保持部材、２３・・・内部マグネット、
２７・・・磁性粒子、２８・・・非磁性現像剤、３６φ
−働固定マグネット、３５＠・・循環ヤグネット、３７
・・・中間歯車。FIG. 1 is a sectional view of a developer thin layer forming apparatus that does not use the present invention. FIG. 2 is a sectional view of a thin developer layer forming device according to an embodiment of the present invention, and FIG. 3 is an enlarged view of the vicinity of a developing sleeve of a thin developer layer forming device according to another embodiment of the present invention. "LΩ" L man 3--Photosensitive drum, 24...Magnetic particle restraining member, 2
2... Developer holding member, 23... Internal magnet,
27...Magnetic particles, 28...Nonmagnetic developer, 36φ
- Working fixed magnet, 35 @... Circulating Yagnet, 37
...Intermediate gear.

Claims (1)

【特許請求の範囲】 開口を有する現像剤供給容器と、 該開口に設けられ、前記容器の内部と外部を無端移動可
能な現像剤保持用非磁性部材と、該保持部材内部に設け
られた磁性部材および固定磁界発生手段と、 前記現像剤保持部材の外側に設けられ、前記磁性部材お
よび前記固定磁界発生手段とともに前記磁性粒子層を現
像剤供給容器内部に拘束する磁石部材と、 前記保持部材内部に設けられ、回転可能な磁界発生手段
、 を有することを特徴とする現像剤薄層形成装置。[Scope of Claims] A developer supply container having an opening; a non-magnetic developer holding member provided in the opening and movable endlessly inside and outside the container; and a magnetic developer provided inside the holding member. a member and a fixed magnetic field generating means; a magnet member provided outside the developer holding member and restraining the magnetic particle layer inside the developer supply container together with the magnetic member and the fixed magnetic field generating means; and an inside of the holding member. What is claimed is: 1. A developer thin layer forming device, comprising: a rotatable magnetic field generating means, which is provided in a rotatable magnetic field generating means.