JPS59229572A - Method for forming thin developer layer - Google Patents

Abstract

PURPOSE:To form a superior toner image by forming a magnetic brush in a magnetic field using a mixture of a spherical nonmagnetic developer (toner) and magnetic particles (carrier), regulating the toner thickness on a developer holding roller, and triboelectrifying the toner sufficiently. CONSTITUTION:An electrophotographic sensitive drum 1 is rotated in the direction of arrow (a), and while a developer holding roller 2 is rotated in the direction of arrow (b), a magnetic brush 8 of a carrier M of spherical magnetic particles coated with a spherical nonmagnetic toner D2 is formed with a magnet 7, and a uniform layer thickness of the toner D2 is formed by using a magnetic blade 6. An electrostatic latent image formed on the drum 1 is developed with said toner D2, and the toner image is transferred to a transfer paper and fixed. Since a uniform thin toner layer can be formed, the image thus obtained is sharp and free from a ghost and fog, etc., and retains image density equal to that obtained in the initial stage after successively forming a large number of copies.

Description

【発明の詳細な説明】 本発明は、現像剤の薄層形成方法及びその為の現像剤に
関する。DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for forming a thin layer of a developer and a developer therefor.

従来、乾式−成分系現像装置としては各種装置が提案さ
れ又実用化されている。しかし、いずれの現像方式にお
いても現像剤の薄層を形成することは極めて難かしくこ
のため比較的厚い層の形成で現像していた。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及びその装置に
関する開発は必須となっている。　従来乾式−成分系現
像剤の薄層を形成する方法は特開昭５４−４３０３７号
公報、同５５−１８６５６号公報等に提案されており、
且つ実用化されている。しかし、これは磁性現像剤の画
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や、カラー再現
の際の色彩が限定されること等の問題点がある。Conventionally, various types of dry-component type developing apparatuses have been proposed and put into practical use. However, in any of the development methods, it is extremely difficult to form a thin layer of developer, and for this reason, development has been performed by forming a relatively thick layer. However, as improvements in the clarity and resolution 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. Conventional methods for forming a thin layer of dry-component type developers have been proposed in Japanese Patent Laid-Open Nos. 54-43037 and 55-18656, etc.
And it has been put into practical use. However, this concerned image formation with magnetic developers. Magnetic developers must contain a magnetic substance to make them magnetic, which limits the fixability when heat fixing the developed image transferred to transfer paper and the color reproduction. There are other problems.

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、均一な塗布は行な
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、ゴースト等の発生しやすい問題点
があった。For this reason, methods for forming a thin layer of non-magnetic developer include using a cylindrical brush made of soft bristles like beaver hair and applying the developer to the brush, or using a brush with a surface made of fibers such as velvet. 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 fiber brush mentioned above, although it is possible to regulate the amount of developer, uniform application is not achieved and the fiber brush on the developing roller is simply rubbed.
Since no triboelectric charge is imparted to the developer existing between the fibers of the brush, there is a problem in that ghosts and the like are likely to occur.

本発明は上述の従来方法の問題点を除き、現像剤、特に
非磁性現像剤を現像剤保持部材表面に均一な薄層として
形成し、且つ、十分な摩擦帯電を与え、塗布する新規な
方法及びその為の現像剤を提供することを目的としてい
る。The present invention eliminates the problems of the conventional method described above, and provides a novel method for coating a developer, particularly a non-magnetic developer, by forming a uniform thin layer on the surface of a developer holding member and applying sufficient triboelectric charging. and to provide a developer therefor.

その特徴とするところは、現像剤供給手段に球状の非磁
性現像剤と磁性粒子とを配し、磁界下で磁性粒子の磁気
ブラシを形成し、非磁性現像剤を現像剤保持部材に供給
し、現像剤保持部材上の非磁性現像剤の層厚を規制する
現像剤薄層形成方法、及び磁界下で形成した磁性粒子の
磁気ブラシを有する現像剤供給手段に配する為の１球状
の非磁性現像剤にある。The feature is that spherical non-magnetic developer and magnetic particles are arranged in the developer supply means, a magnetic brush of the magnetic particles is formed under a magnetic field, and the non-magnetic developer is supplied to the developer holding member. , a developer thin layer forming method for regulating the layer thickness of non-magnetic developer on a developer holding member, and a method for forming a thin layer of non-magnetic developer on a developer holding member; In magnetic developer.

ここで、球状の非磁性現像剤は、ワーデルの実用球形度
が０．８５〜１．００であるのが良い。Here, it is preferable that the spherical nonmagnetic developer has a practical Wardell sphericity of 0.85 to 1.00.

本発明に係る現像剤薄層形成方法あるいは非磁性現像剤
を適用するのに好適な装置の一例は、非磁性現像剤を保
持する現像剤保持部材と、非磁性現像剤を現像剤保持部
材表面に供給する現像剤供給手段と、現像剤保持部材表
面に間隙を形成して配置したブレードと、磁性ブレード
に対し現像剤保持部材を介して反対側に配置され、且つ
磁性ブレードの対向する位置より現像剤保持部材の移動
方向上流側に配置された磁石と、磁石と磁性ブレードと
の磁界下に形成した磁性粒子よりなる磁気ブラシと、を
有する現像剤薄層形成装置である。An example of an apparatus suitable for applying the developer thin layer forming method or the non-magnetic developer according to the present invention includes a developer holding member that holds the non-magnetic developer, and a device that holds the non-magnetic developer on the surface of the developer holding member. a blade disposed with a gap formed on the surface of the developer holding member; and a blade disposed on the opposite side of the magnetic blade with the developer holding member interposed therebetween, and from a position facing the magnetic blade. This developer thin layer forming device includes a magnet disposed upstream in the direction of movement of a developer holding member, and a magnetic brush made of magnetic particles formed under a magnetic field between the magnet and a magnetic blade.

本発明について以下詳細に説明する。The present invention will be explained in detail below.

第１図は、本発明に係る現像剤薄層形成方法を適用する
非磁性現像剤薄層形成装置の一例の説明図である。同図
において、［は円筒状電子写真感光体であり矢印方向ａ
に移動する。この感光体に対して間隙を介して現像剤を
保持する円筒状現像剤保持部材２を矢印す方向に回転移
動させる。この現像剤保持部材に現像剤を供給するため
に現像剤供給容器３が設けられている。また現像剤容器
の入口側には包囲体４が円筒状現像剤保持部材の下方を
包んでおり、この包囲体４との間には現像剤が漏れない
ようにシール部材５が設けられている。この現像剤供給
容器３の出口には磁性体よりなる磁性ブレード６が配置
されている。この磁性ブレードに対して現像剤保持部材
の反対側には磁石７が設けられている。この磁石の位置
は磁性ブレード６の対向する位置より円筒状現像剤保持
部材２の回転方向上流側位置（円筒状現像剤保持部材の
中心から磁性ブレード及び磁石の磁極位置を見た角度θ
分上流側位置）に配置されている。FIG. 1 is an explanatory diagram of an example of a non-magnetic developer thin layer forming apparatus to which the developer thin layer forming method according to the present invention is applied. In the figure, [ is a cylindrical electrophotographic photoreceptor in the direction of the arrow a
Move to. The cylindrical developer holding member 2 that holds the developer with a gap therebetween is rotated in the direction indicated by the arrow. A developer supply container 3 is provided to supply developer to this developer holding member. Further, on the entrance side of the developer container, an enclosure 4 surrounds the lower part of the cylindrical developer holding member, and a sealing member 5 is provided between the enclosure 4 and the enclosure 4 to prevent the developer from leaking. . At the outlet of the developer supply container 3, a magnetic blade 6 made of a magnetic material is arranged. A magnet 7 is provided on the opposite side of the developer holding member with respect to the magnetic blade. The position of this magnet is a position upstream in the rotational direction of the cylindrical developer holding member 2 from the position facing the magnetic blade 6 (an angle θ when looking at the magnetic pole position of the magnetic blade and the magnet from the center of the cylindrical developer holding member).
(upstream position).

かかる構成の現像装置に磁性粒子Ｍと非磁性現像剤りと
を上記現像剤供給容器に供給することにより、磁性粒子
のブラシ８が磁性ブレードと磁石の対向する円筒状現像
剤保持部材表面との間に形成される。円筒状現像剤保持
部材の回転により磁性粒子と非磁性現像剤は攪拌混合さ
れて摩擦帯電する。By supplying the magnetic particles M and the non-magnetic developer to the developer supply container in the developing device having such a configuration, the brush 8 of the magnetic particles is brought into contact with the surface of the cylindrical developer holding member where the magnetic blade and the magnet face each other. formed between. As the cylindrical developer holding member rotates, the magnetic particles and non-magnetic developer are stirred and mixed and triboelectrically charged.

摩擦帯電された非磁性現像剤は磁性ブレード部に形成さ
れた磁気ブラシ部より円筒状現像剤保持部材表面に鏡映
力により均一に薄くコーティングされる。一方、磁気ブ
ラシ８を構成している磁性粒子は磁石７による磁界の拘
束力が、円筒状現像剤保持部材２と磁性粒子の静電付着
力、機械的な摩擦力に依存する搬送力より大となるよう
に設定されるため、非磁性現像剤と共に円筒状現像剤保
持部材２上にコーティング搬送されることはない。The triboelectrically charged non-magnetic developer is uniformly and thinly coated on the surface of the cylindrical developer holding member by a mirror force from a magnetic brush portion formed in the magnetic blade portion. On the other hand, for the magnetic particles constituting the magnetic brush 8, the binding force of the magnetic field by the magnet 7 is greater than the conveying force that depends on the electrostatic adhesion force between the cylindrical developer holding member 2 and the magnetic particles and the mechanical friction force. Therefore, the developer is not coated and conveyed onto the cylindrical developer holding member 2 together with the non-magnetic developer.

また、通常の状態では磁気ブラシ８部に非磁性現像剤が
あれば、磁気ブラシ部での磁性粒子に対する非磁性現像
剤の比率は、はぼ一定値になっている。従って、コーテ
ィングされた非磁性現像剤を公知の手段により現像に使
用して消費した場合も自動的に非磁性現像剤が磁気ブラ
シ８部に供給されるため、常に一定量のコーティングが
可能である。Further, under normal conditions, if there is non-magnetic developer in the magnetic brush 8 portion, the ratio of the non-magnetic developer to the magnetic particles in the magnetic brush portion is approximately constant. Therefore, even if the coated non-magnetic developer is used for development by known means and consumed, the non-magnetic developer is automatically supplied to the 8 magnetic brushes, so a constant amount of coating is always possible. .

かかる構成の現像装置において、使用する非磁性現像剤
は少なくとも以下の条件を満足する必要がある。すなわ
ち、該現像剤は、現像剤供給容器内より近滞することな
く現像剤保持部材上に運ばれ、その後該保持部材上の磁
性粒子と速やかに混合され、速やかに帯電されなくては
ならない。In the developing device having such a configuration, the non-magnetic developer used must satisfy at least the following conditions. That is, the developer must be transported onto the developer holding member from within the developer supply container without stagnation, and then quickly mixed with the magnetic particles on the holding member and quickly charged.

上述の現像装置に従来の粉砕法による不定形の非磁性現
像剤を使用する場合、上記の条件を満足させるために次
のような改良を加えねばならない。つまり、従来の現像
剤では現像剤保持部材上へ遅滞することなく供給される
には流動性が低いため、流動性向上剤を更に加えなけれ
ばならない場合が生じる。更に、該現像剤が磁性粒子と
混合して速やかに帯電するためには、磁性粒子を大量に
使用し、接触回数を増やす必要がある。When using the amorphous non-magnetic developer produced by the conventional pulverization method in the above-mentioned developing device, the following improvements must be made in order to satisfy the above-mentioned conditions. In other words, since the fluidity of the conventional developer is too low to be supplied onto the developer holding member without delay, it may be necessary to further add a fluidity improver. Furthermore, in order for the developer to be mixed with magnetic particles and quickly charged, it is necessary to use a large amount of magnetic particles and increase the number of times of contact.

しかしながら、このような改良により、かなり優れた画
像を得ら−れるまでになったとしても、それでも尚、従
来の現像剤を使用した場合、ムラ、カブリ、画像濃度変
移などが生じる場合があり、安定した画質を得るために
は、いま−歩の改良が必要とされていた。そこで、本発
明者らは、更に研究を重ねた結果、球状の現像剤粒子よ
り成る現像剤が上記の必要条件を満足し、かつ、残され
た問題点を解決し、上述の様な現像装置に最適な現像剤
であるという結論に達した。However, even though these improvements have made it possible to obtain considerably superior images, when conventional developers are used, unevenness, fogging, and changes in image density may still occur. In order to obtain stable image quality, significant improvements were needed. As a result of further research, the inventors of the present invention have found that a developer made of spherical developer particles satisfies the above requirements and solves the remaining problems. We have reached the conclusion that this is the best developer for.

球状現像剤は懸濁重合、乳化重合、マイクロカプセル、
スプレードライ等により得られるが、本発明のためにＷ
ｉｄｅｌｌ　（ワーデル）の実用球形度が０．８５〜１
．００である実質上球形の現像剤を開発して用いたとこ
ろ、良好な結果を得た。Spherical developers can be used for suspension polymerization, emulsion polymerization, microcapsules,
Although it can be obtained by spray drying etc., for the purpose of the present invention, W
Idell (Wardell) practical sphericity is 0.85-1
．． A substantially spherical developer of 0.00 was developed and used with good results.

Ｗａｄｅ　ｌ　ｌの実用球形度とは次式で表わされる。Wade's practical sphericity is expressed by the following equation.

Ｗａｄｅ　ｌ　＋の実用球形度 不定形の現像剤を使用した場合と、球形の現像剤を使用
した場合の相違を、以下に詳しく説明する。Practical sphericity of Wade l + The difference between the case where a developer with irregular sphericity is used and the case where a spherical developer is used will be explained in detail below.

該現像装置における非磁性現像剤の帯電は、主として磁
性粒子と現像剤保持体の間を該現像剤が通り抜ける際に
生ずる摩擦帯電である。The charging of the non-magnetic developer in the developing device is mainly due to frictional charging that occurs when the developer passes between the magnetic particles and the developer holder.

本発明構成で、球状の現像剤Ｄ２と従来の不定形現像剤
ＯＬの磁性粒子との付着状態の様子を顕微鏡観察したと
ころ、第２図（ａ）（ｂ）のような結果を得た。When the state of adhesion between the spherical developer D2 and the magnetic particles of the conventional amorphous developer OL in the configuration of the present invention was observed under a microscope, the results shown in FIGS. 2(a) and 2(b) were obtained.

すなわち、従来の粉砕法による現像剤Ｄ１は、その製造
特性上不定形で表面性が不均一な粒子であり、磁性粒子
及び現像保持体との帯電状態は第２図（Ｃ）の拡大図に
示す如くなる。That is, the developer D1 produced by the conventional pulverization method has particles with an irregular shape and uneven surface properties due to its manufacturing characteristics, and the charging state of the magnetic particles and the developer carrier is shown in the enlarged view of FIG. 2 (C). It will be as shown.

ただし、第２図では、磁性粒子をわかりやすいように球
形で示しであるが、これになんら限定されるものではな
く、不定形の磁性粒子であっても現像、結果は変わるも
のではない。However, in FIG. 2, the magnetic particles are shown as spherical to make it easier to understand, but the invention is not limited to this in any way, and the development results will not change even if the magnetic particles are irregularly shaped.

不定形現像剤粒子（第２図（ａ）のＤ＋　）のエツジ部
に電荷が集中しく（Ｃ）の拡大図）、−個の現像剤粒子
自身の帯電が均一でなく遍在している。The charge is concentrated at the edge portion of the amorphous developer particle (D+ in FIG. 2(a)) (an enlarged view of FIG. 2(C)), and the charge on the - developer particle itself is not uniform but distributed everywhere.

そのため、静電気的に現像剤粒子同士が引きつけ合い、
磁気ブラシ付近で凝集体をつくりやすく、これが、現像
剤の現像剤保持体上への供給を遅滞させる原因となる。Therefore, developer particles attract each other electrostatically,
Aggregates tend to form near the magnetic brush, which causes a delay in the supply of developer onto the developer holder.

また、現像剤保持体上の個々の現像剤粒子の帯電電荷の
差が大きく、電荷分布の幅が広いため、現像特性がバラ
つき、カブリ、ムラ等の原因となる。Furthermore, since the difference in charge between individual developer particles on the developer holder is large and the width of the charge distribution is wide, this causes variations in development characteristics, fog, unevenness, and the like.

これに対して、球状の現像剤は、その製法上、粒径がほ
ぼ均一であり、表面性が均一であるため、その帯電性は
第２図（ｄ）の拡大図の如く、１個の粒子自身の帯電電
荷が遍在せず、均一である。故に静電気的な粒子同士の
凝集がなく、その上、流動性もその形状から非常に優れ
ており現像剤保持体への供給がスムーズである。ここで
、流動性は良好ではあるが必要に応じて、一般に知られ
ているシリカ等の流動性向上剤を補充してもよい、また
、球状で、はぼ均一粒径であるので、磁性粒子との接触
機会が各粒子同等であり、生ずる帯電電荷もほぼ同じで
あり、そのため、現像特性が各粒子同−であるので、従
来の現像剤にみられるカブリ、ムラ等が生じない、更に
、従来の不定形の現像剤を使用した場合、比較的多量の
磁性粒子を使用し、磁性粒子の循環運動により塗布する
現像剤薄層の規制を行なう必要があるが、本発明では、
球状の現像剤は磁性粒子や現像剤保持体との数少ない接
触で、粒子表面全体に容易に摩擦帯電が生ずるため、使
用する磁性粒子は非常番と少量でも塗布がｕ５能である
。On the other hand, spherical developer has almost uniform particle size and uniform surface properties due to its manufacturing method, so its chargeability is as shown in the enlarged view of Figure 2(d). The charges on the particles themselves are not omnipresent and uniform. Therefore, there is no electrostatic aggregation of particles, and in addition, the fluidity is excellent due to its shape, and supply to the developer holder is smooth. Although the fluidity is good, if necessary, a fluidity improver such as silica, which is generally known, may be supplemented. Each particle has the same opportunity to come into contact with the developer, and the electrostatic charge generated is almost the same, so the development characteristics are the same for each particle, so there is no fogging, unevenness, etc. that occurs with conventional developers. When using a conventional amorphous developer, it is necessary to use a relatively large amount of magnetic particles and to control the thin layer of developer applied by the circular movement of the magnetic particles, but in the present invention,
The spherical developer easily generates triboelectrification on the entire surface of the particles due to the small amount of contact with the magnetic particles or the developer holder, so even if the magnetic particles used are extremely large or small, coating is possible.

ここで、磁性粒子の量は、現像剤保持部材を垂直力向に
νＪつだ時に磁性粒子が形成する包絡線と該保持部材と
磁性ブレードにより囲まれる面積（断面積Ａと呼ぶ）が
０．０２ｃ＋ｏ２〜３ＣＩ１１２好ましくはＱ、１　ｃ
＋ｎ２〜ｌ　ｃ＋ｏ２　となる量が適当である。Here, the amount of magnetic particles is determined by the envelope formed by the magnetic particles when the developer holding member is moved in the vertical direction of force νJ and the area (referred to as cross-sectional area A) surrounded by the holding member and the magnetic blade of 0. 02c+o2~3CI112 preferably Q, 1 c
An appropriate amount is +n2 to lc+o2.

磁性粒子の量が断面積Ａ　＞　３　ａｍ２を越えると、
磁石７伺近の現像剤保持部材を介して反対側に形成され
る磁気ブラシの磁石方向への引きつけられる力が強すぎ
、現像剤が該磁気ブラシと現像剤保持部材の間を通過す
る際又は、磁性粒子間を通過する際に発生する摩擦帯電
電荷が非常に高くなりすぎてしまう。When the amount of magnetic particles exceeds the cross-sectional area A > 3 am2,
The attraction force of the magnetic brush formed on the opposite side of the magnet 7 in the direction of the magnet via the developer holding member near the magnet 7 is too strong, and when the developer passes between the magnetic brush and the developer holding member, or , the triboelectric charge generated when passing between magnetic particles becomes too high.

また、断面積Ａ　＜　０．０２ｃＩＩ＋２であると、現
像剤保持体を充分被えず、又、現像剤の帯電にもムラが
できるので好ましくない。Further, if the cross-sectional area A < 0.02cII+2, the developer holder will not be sufficiently covered and the developer will be charged unevenly, which is not preferable.

−・方、不定形の現像剤を使用する場合においては、磁
性粒子は最小でもＡは２ｃｍ２．以上望ましくは４ｃｍ
１２以上必要であり、２Ｃ１１２以下では塗布層厚が著
しく大きくなって、十分に帯電した塗布が得られない。- On the other hand, when using an amorphous developer, the minimum size of magnetic particles A is 2 cm2. Preferably 4cm or more
12 or more is required, and if it is less than 2C112, the coating layer thickness becomes extremely large and a sufficiently charged coating cannot be obtained.

これは第２図で示した磁性粒子と現像剤の伺着状態の差
に起因すると推定される。This is presumed to be due to the difference in adhesion between the magnetic particles and the developer shown in FIG.

〔実施例１〕 本発明の一実施例を第３図により説明する。[Example 1] An embodiment of the present invention will be described with reference to FIG.

第３図に於いて、ｌは円筒状電子写真感光体であり矢印
ａ方向に回転移動する。２は直径３０ｍｍの５ｕｓ３０
４製の現像剤保持部材である。この現像剤保持部材表面
は＃６００７ランダム砥粒により不定型サンドブラスト
を施し、周方向表面粗度をＲｚ＝０．８ｇｍにしている
。この現像剤保持部材２内には、フェライト焼結タイプ
の磁石７が内在し、図示のようにＮ磁極を磁性ブレード
６に対しθ＝１５度（磁石の円筒状現像剤保持部材表面
での対向位置と磁性ブレードとの間の距離が４．２ｍｍ
）傾けて配置している。この磁極Ｎは表面磁束密度８５
０Ｇ、半値幅８．４ｍｍ（円筒状現像剤保持部材表面に
おける幅）であり、磁極Ｓは表面磁束密度６５０Ｇであ
る。Ｓは現像剤供給容器３の図示位置にあり非磁性現像
剤には何ら影響を及ぼさないが、Ｎ磁極を強い表面磁束
密度にし、かつ、磁石製造上の都合により配置されてい
る。磁性ブレード６は鉄製であり、表面にサビ止めの為
にニッケルメッキを施している。また。In FIG. 3, l is a cylindrical electrophotographic photoreceptor that rotates in the direction of arrow a. 2 is 5us30 with a diameter of 30mm
This is a developer holding member manufactured by No. 4. The surface of this developer holding member was subjected to amorphous sandblasting using #6007 random abrasive grains, and the surface roughness in the circumferential direction was set to Rz=0.8 gm. A sintered ferrite type magnet 7 is contained in this developer holding member 2, and as shown in the figure, the N magnetic pole is θ=15 degrees with respect to the magnetic blade 6 (the magnet is opposed to the surface of the cylindrical developer holding member). The distance between the position and the magnetic blade is 4.2mm
) It is placed at an angle. This magnetic pole N has a surface magnetic flux density of 85
0G and a half width of 8.4 mm (width on the surface of the cylindrical developer holding member), and the magnetic pole S has a surface magnetic flux density of 650G. S is located at the illustrated position of the developer supply container 3 and does not have any effect on the non-magnetic developer, but it is placed to make the N magnetic pole have a strong surface magnetic flux density and for convenience in magnet manufacturing. The magnetic blade 6 is made of iron, and its surface is nickel plated to prevent rust. Also.

先端形状を図示のようにくさび形状としている。The tip has a wedge shape as shown in the figure.

これは１例えば直方形断面彫工の如くエツジ部分が他に
もあるとそのエツジ部分にも磁界が集中し、ここに磁性
粒子を引きつける力が発生し、磁性粒子がその部分から
もれ出す恐れがある為である。この磁性ブレー　ドロは
円筒状現像剤保持部材２の表面に対してその間隔を３０
０７ｚｍに設定した。This is because 1. For example, if there are other edge parts such as a rectangular cross-section carving, the magnetic field will also concentrate on that edge part, generating a force that attracts magnetic particles, and there is a risk that the magnetic particles will leak from that part. It is for a certain reason. The distance between this magnetic blade roller and the surface of the cylindrical developer holding member 2 is 30 mm.
It was set to 07zm.

磁性粒子Ｍとしては粒径８０〜１５０ＪＬ、最大磁化７
５ｅｍｕ／Ｈの球状フェライト５ｇを用いた。The magnetic particles M have a particle size of 80 to 150 JL and a maximum magnetization of 7.
5 g of spherical ferrite of 5 emu/H was used.

断面積Ａ　＝　０．７０ｍ２であった。これに、非磁性
現像剤りとして、スチレンモノマーを懸濁重合より重合
した球状のスチレンマレイン酩共重合体（顔料としての
フタロシアンブルー、離型助剤等を含有する）、平均粒
径１１　ＭＷａｄｅｌｌ　　の実用球形度値０．８９の
ポジ現像剤を１０ｇ加えて用意した。この磁性粒子Ｍと
非磁性現像剤りをよく混合した後、現像剤供給容器内に
入れる。これら磁性粒子と非磁性現像剤は第３図の磁石
Ｎ及びＳ極付近に磁力によりブラシを形成し、付着する
。このような状態で円筒状現像剤保持部材２を矢印ａ方
向に回転せしめると、この円筒状現像剤保持部材の回転
に伴い、非磁性現像剤が磁性粒子と共に攪拌循環し、円
筒状現像剤保持部材上には非磁性現像剤のみのコーティ
ングが得られた。　この後、上述の非磁性現像剤のみを
更に２００ｇ補給し１円筒状現像剤保持部材を回転させ
たところ、円筒状現像剤保持部材上に良好な均一な非磁
性現像剤のコーティングが得られた。The cross-sectional area A = 0.70 m2. In addition, as a non-magnetic developer, a spherical styrene-malein copolymer (containing phthalocyan blue as a pigment, a release aid, etc.) obtained by polymerizing styrene monomer by suspension polymerization, and an average particle size of 11 MWadell were added. 10 g of a positive developer with a practical sphericity value of 0.89 was prepared. After thoroughly mixing the magnetic particles M and non-magnetic developer, they are placed in a developer supply container. These magnetic particles and nonmagnetic developer form brushes and adhere to the vicinity of the N and S poles of the magnet shown in FIG. 3 by magnetic force. When the cylindrical developer holding member 2 is rotated in the direction of arrow a in this state, as the cylindrical developer holding member 2 rotates, the non-magnetic developer is stirred and circulated together with the magnetic particles, and the cylindrical developer holding member 2 is rotated. A coating of non-magnetic developer only was obtained on the member. After this, an additional 200 g of the above-mentioned non-magnetic developer was replenished and the cylindrical developer holding member was rotated, and a good and uniform coating of the non-magnetic developer was obtained on the cylindrical developer holding member. .

なお、第３図でＮ極と磁性ブレードの成す角θを３０度
（磁石の円筒状現像剤保持部材表面での対向位置に磁性
ブレードとの間の距離が８．４ｍ　ｍ　）にすると円筒
状現像剤保持部材上に比較的厚い非磁性現像剤コーティ
ング層が得られ現像に供したとき、更に濃度の高い画像
を得られるが、磁性ブレード位置での磁性粒子への拘束
力が弱くなるためその拘束状態は不安定となり、磁性粒
子が磁性ブレードを通り抜けることがあった。また先に
述べた如くあらかじめ非磁性現像剤の一部と磁性粒子を
混合することにより、初期より安定したコーティングを
得ることができる。あらかじめ非磁性現像剤と磁性粒子
を混合せずに、磁性粒子のみを最初に投入した後、非磁
性現像剤を補給すると双方が充分に混合されるまで、コ
ーティングに厚みムラが発生しやすい。また磁性粒子の
みを磁性ブレードの部分に拘束することは難しく非磁性
現像剤の存在がある場合に初めて磁性粒子の完全な拘束
が可能であった。これは、磁性粒子に付着した非磁性現
像剤が円筒状現像剤保持部材と磁性粒子の摩擦を減じる
ためと考えられる。In addition, in Fig. 3, if the angle θ between the N pole and the magnetic blade is 30 degrees (the distance between the magnetic blade and the magnet at the opposing position on the surface of the cylindrical developer holding member is 8.4 mm), the cylindrical shape is When a relatively thick non-magnetic developer coating layer is obtained on the developer holding member and subjected to development, an image with even higher density can be obtained, but the binding force on the magnetic particles at the magnetic blade position is weakened. The restraint state became unstable, and magnetic particles could sometimes pass through the magnetic blades. Further, as mentioned above, by mixing a portion of the non-magnetic developer and the magnetic particles in advance, a stable coating can be obtained from the initial stage. If the non-magnetic developer and magnetic particles are not mixed in advance and only the magnetic particles are initially introduced and then the non-magnetic developer is replenished, the coating tends to become uneven in thickness until both are sufficiently mixed. Furthermore, it is difficult to restrict only the magnetic particles to the magnetic blade, and complete restriction of the magnetic particles is only possible in the presence of a non-magnetic developer. This is thought to be because the non-magnetic developer attached to the magnetic particles reduces the friction between the cylindrical developer holding member and the magnetic particles.

なおＳ極伺近にも磁性粒子を拘束させ、現像剤供給容器
３をこの部分で狭くすることにより、現像剤供給容器下
部からの非磁性現像剤漏れを防ぐことができる。Note that by restraining the magnetic particles near the S pole and narrowing the developer supply container 3 at this portion, leakage of non-magnetic developer from the lower part of the developer supply container can be prevented.

このようにして得られた非磁性現像剤コーティング層を
現像作用に供するため、静電潜像として暗部＋５００Ｖ
、明部−５０Ｖを有する電子写真感光体に、該表面と円
筒状現像剤保持部材表面間を３００　＃Ｌｍの間隔をお
いて、円筒状現像剤保持部材と電子写真感光体の間に周
波数ＩＥ１００Ｈｚ　。In order to subject the non-magnetic developer coating layer obtained in this way to a developing action, the dark area was heated to +500V as an electrostatic latent image.
, a frequency IE of 100 Hz was applied between the cylindrical developer holding member and the electrophotographic photosensitive member, with a distance of 300 #Lm between the surface and the surface of the cylindrical developer holding member. .

ピーク対ピーク値１．６ＫＶ、中心値−３（）ＯＶの電
圧を電源Ｅにより加え、キャノン製ＰＣ−２０複写機に
より複写画像を得たところ、良好な、ゴーストやカブリ
等のない鮮明画像が得られた。When a voltage with a peak-to-peak value of 1.6 KV and a center value of -3 () OV was applied from power supply E, a copied image was obtained using a Canon PC-20 copier, and a good, clear image without ghosts or fog was obtained. Obtained.

更に約２０００枚コピー後の、非磁性現像剤が殆んど消
費された状態まで画像濃度の変動はなく、初期の画質と
同様の画像が得られ、磁性粒子が現像に供せられること
もなかった。Furthermore, after copying approximately 2,000 sheets, there was no change in image density until the non-magnetic developer was almost consumed, and an image with the same quality as the initial image was obtained, and no magnetic particles were used for development. Ta.

〔比較例１〕 非磁性現像剤りとして実施例と同じ組成で、粉砕法によ
り製造したトナー、平均粒径１２．の不定形のポジ現像
剤を使用して、該実施例の装置にてキャノン製ＰＣ−２
０複写機によ１コピーしたところ、カブリがひどく、ま
た、トナーが遅滞してしまい、トナーの供給が現像にお
いつかず、実用レベルにはほど遠い画像であった。[Comparative Example 1] A toner having the same composition as the example as a non-magnetic developer and produced by a pulverization method, with an average particle size of 12. Using the amorphous positive developer of Canon PC-2 in the apparatus of this example
When I made one copy using a copying machine, there was severe fog, and the toner supply was delayed, and the toner supply was not sufficient for development, resulting in an image that was far from practical.

〔実施例２〕 実施例１において非磁性現像剤をスチレンマレイン酸共
重合体及び顔料（カーボンブラック）を熱混練粉砕して
得た粉体をスプレードライ法により球状化したものに変
えた。この現像剤は平均粒径ｌｏｇ、Ｗａｄｅ　ｌ　ｌ
の実用球形度０．１１８５であった。[Example 2] In Example 1, the non-magnetic developer was changed to a powder obtained by thermally kneading and pulverizing a styrene-maleic acid copolymer and a pigment (carbon black) and spheroidizing it by spray drying. This developer has an average particle size log, Wade l l
The practical sphericity was 0.1185.

これを実施例１と同様にして良好なコーティングが得ら
れ、実施例１と同様にしてキャノン製ＰＣ−２０複写機
により複写画像を得たところ、カブリ、ムラ等のない鮮
明な画像が得られた。更に約２０００枚コピー後の非磁
性現像剤が殆んど消費された状態まで画像濃度の変動は
なく、磁性粒子が現像に供せられることもなかった。A good coating was obtained in the same manner as in Example 1, and when a copied image was obtained using a Canon PC-20 copier in the same manner as in Example 1, a clear image without fogging or unevenness was obtained. Ta. Furthermore, after copying approximately 2,000 sheets, there was no change in image density until the non-magnetic developer was almost consumed, and no magnetic particles were used for development.

〔比較例２〕 実施例２と同様にして得た粉体を球状化せず、そのまま
現像剤として使用したところ、カブリ、及びスジが発生
し、未帯電の現像剤が現像に供せられてしまった。[Comparative Example 2] When the powder obtained in the same manner as in Example 2 was used as a developer without being spheroidized, fog and streaks occurred, and the uncharged developer was used for development. Oops.

（実施例３〕 実施例１において、磁性粒子を粒径４４ＩＬ〜７４１Ｌ
、最大磁化１９５　ｅｍｕ／ｇの不定形鉄粉４ｇ、断面
積Ａ　＝　０．４　ｃｍ２に変えて使用した。その結果
、実施例１と同様の優れた複写画像が得られた。(Example 3) In Example 1, the magnetic particles had a particle size of 44IL to 741L.
, 4 g of amorphous iron powder with a maximum magnetization of 195 emu/g, and a cross-sectional area A = 0.4 cm2 were used. As a result, an excellent copy image similar to that of Example 1 was obtained.

〔比較例３〕 実施例３において非磁性現像剤を粉砕法による不定形も
のに変えたところ、未帯電の現像剤が多く、スリーブ上
にスジが発生してしまい、これが複写画像にも現れてし
まった。[Comparative Example 3] In Example 3, when the non-magnetic developer was changed to an amorphous one made by pulverization, there was a lot of uncharged developer, and streaks appeared on the sleeve, which also appeared in the copied image. Oops.

〔実施例４〕 実施例１において非磁性現像剤に、芯材がパラフィン、
顔料（フタロシアニンブルー）及び滑剤、外殻がスチレ
ン−ＤＭから成る球形カプセル平均粒径９井、Ｗａｄｅ
　Ｉ　１球形度０．９１１５を使用して、実施例１と同
様にして現像材保持部材上に良好な現像剤コートを得た
。[Example 4] In Example 1, the core material was paraffin,
Pigment (phthalocyanine blue) and lubricant, spherical capsules with outer shell made of styrene-DM, average particle size 9 wells, Wade
A good developer coat was obtained on the developer holding member as in Example 1 using I 1 sphericity of 0.9115.

実施例１同様キャノン製ＰＣ−２０（但し、熱定着器を
取りはずしたもの）にてコピーし、別定着器にて圧力１
５ｋｇで定着させたところ、カブリ等のない良好な画像
が得られた。更に約２０００枚コピー後も２画像に変化
はなく良好で、現像剤保持部材上に融着等も発生しなか
った。As in Example 1, copies were made using a Canon PC-20 (however, the heat fixing device was removed), and a pressure of 1 was applied using a separate fixing device.
When fixing was carried out using 5 kg, a good image without fogging etc. was obtained. Further, even after copying approximately 2,000 sheets, the two images remained in good condition with no change, and no fusion or the like occurred on the developer holding member.

〔実施例５〕 実施例４において、磁性粒子の量を４０ｇ、断面積Ａ　
＝　　３．５ｃｍ２にかえて実施例４と同様に複写した
ところ、約１０００枚のコピーでは良好であった。２０
００枚のコピー後、現像剤保持部材上に、若干の現像剤
の融着がみられ、画像もやや汚れが出た。[Example 5] In Example 4, the amount of magnetic particles was 40 g, and the cross-sectional area was A.
When copies were made in the same manner as in Example 4 except that the size of the paper was changed to 3.5 cm2, the results were good after about 1000 copies were made. 20
After copying 00 sheets, some developer was observed to be fused onto the developer holding member, and the image was also slightly smeared.

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

第１図は本発明の現像剤薄層形成方法を適用する非磁性
現像剤薄層形成装置の一例の説明図。 第２図（ａ）は、不定形現像剤と磁性粒子との付着状態
の説明図。第２図（ｂ）は、球状現像剤と磁性粒子との
付着状態の説明図、第２図（ｃ）は、不定形現像剤の拡
大説明図。第２図（ｄ’）は、球状現像剤の拡大説明図
。 第３図は、本発明の具体的実施例に適用した非磁性現像
剤薄層形成装置の説明図。 ｌ：電子写真感光体。２：現像剤保持体。３：現像剤供
給容器、４：包囲体。５：シール部材。 ６：磁性ブレード。７：磁石。８：磁気ブラシ。 Ｄ：現像剤。Ｍ：磁性粒子。Ｃ：非磁性現像剤の流れ方
向。 出願人：　キャノン株式会社FIG. 1 is an explanatory diagram of an example of a nonmagnetic developer thin layer forming apparatus to which the developer thin layer forming method of the present invention is applied. FIG. 2(a) is an explanatory diagram of the state of adhesion between an amorphous developer and magnetic particles. FIG. 2(b) is an explanatory diagram of the adhesion state of the spherical developer and magnetic particles, and FIG. 2(c) is an enlarged explanatory diagram of the amorphous developer. FIG. 2(d') is an enlarged explanatory diagram of a spherical developer. FIG. 3 is an explanatory diagram of a non-magnetic developer thin layer forming apparatus applied to a specific embodiment of the present invention. l: Electrophotographic photoreceptor. 2: Developer holding body. 3: developer supply container, 4: enclosure. 5: Seal member. 6: Magnetic blade. 7: Magnet. 8: Magnetic brush. D: Developer. M: Magnetic particles. C: Flow direction of non-magnetic developer. Applicant: Canon Co., Ltd.

Claims (1)

【特許請求の範囲】 （，１）現像剤供給手段に球状の非磁性現像剤と磁性粒
子とを配し、磁界下で磁性粒子の磁気ブラシを形成し、
非磁性現像剤を現像剤保持部材に供給し、現像剤保持部
材上の非磁性現像剤の層厚を規制することを特徴とする
現像剤薄層形成方法。 （２）非磁性現像剤は、ワーデルの実用球形度が０．８
５〜１．００である特許請求の範囲第１項記載の現像剤
薄層形成方法。 （３）磁界下で形成した磁性粒子の磁気ブラシを有する
現像剤供給手段に配する為の、球状の非磁性現像剤。[Claims] (1) A spherical non-magnetic developer and magnetic particles are arranged in a developer supply means, and a magnetic brush of the magnetic particles is formed under a magnetic field,
A method for forming a thin layer of developer, characterized by supplying non-magnetic developer to a developer holding member and regulating the layer thickness of the non-magnetic developer on the developer holding member. (2) The non-magnetic developer has a Wardel practical sphericity of 0.8
5 to 1.00. The method for forming a thin developer layer according to claim 1. (3) A spherical non-magnetic developer to be placed in a developer supply means having a magnetic brush of magnetic particles formed under a magnetic field.