JPH0731454B2 - Development device - Google Patents
Development deviceInfo
- Publication number
- JPH0731454B2 JPH0731454B2 JP60257540A JP25754085A JPH0731454B2 JP H0731454 B2 JPH0731454 B2 JP H0731454B2 JP 60257540 A JP60257540 A JP 60257540A JP 25754085 A JP25754085 A JP 25754085A JP H0731454 B2 JPH0731454 B2 JP H0731454B2
- Authority
- JP
- Japan
- Prior art keywords
- toner
- latent image
- developing
- outer layer
- developing roller
- 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.)
- Expired - Fee Related
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Description
【発明の詳細な説明】 技術分野 本発明は、導電体とその外側に位置する外側層とを備え
たトナー担持体を具備し、該担持体の外側層上に薄層状
態で担持された摩擦帯電トナーによって、潜像担持体に
形成された静電潜像を可視像化する現像装置に関する。Description: TECHNICAL FIELD The present invention comprises a toner carrier provided with a conductor and an outer layer located on the outer side thereof, and friction carried in a thin layer state on the outer layer of the carrier. The present invention relates to a developing device that visualizes an electrostatic latent image formed on a latent image carrier with charged toner.
従来技術 必要に応じて補助剤を外添したトナー、すなわち一成分
系現像剤を用いる上記形式の現像装置は従来より周知で
あり、電子複写機、プリンタあるいはファクシミリ等の
作像装置に採用される。2. Description of the Related Art A developing device of the type described above that uses a toner to which an auxiliary agent is externally added as required, that is, a one-component developer is well known in the prior art, and is used in an image forming device such as an electronic copying machine, a printer or a facsimile. .
ところで、この種の現像方式は一般に正転現像と反転現
像に大別することができ、たとえばネガ原稿からポジ画
像を得る複写機、あるいはレーザビームによって潜像担
持体に静電潜像を形成するレーザプリンタ等においては
反転現像が採用される。ところが、冒頭に記載した形式
の現像装置によって反転現像を行った場合、現像された
可視像が不鮮明となり、場合によっては所定の可視像が
得られないことのあることが最近の検討の結果明らかと
なった。By the way, this type of developing system can be generally classified into normal development and reversal development. For example, a copier that obtains a positive image from a negative original, or an electrostatic latent image is formed on a latent image carrier by a laser beam. Reversal development is adopted in laser printers and the like. However, as a result of recent studies, when reversal development is performed by the developing device of the type described at the beginning, the developed visible image may become unclear and the predetermined visible image may not be obtained in some cases. It became clear.
目的 本発明は上記認識に基きなされたものであり、その目的
とするところは、冒頭に記載した形式の現像装置を、反
転現像に支障なく用いることができるように構成するこ
とにある。OBJECT The present invention has been made on the basis of the above recognition, and an object thereof is to configure a developing device of the type described at the beginning so that it can be used for reversal development without any trouble.
構成 本発明は、上記目的を達成するため、静電潜像を反転現
像すべくトナー担持体の導電体にトナー粒子の帯電極性
と同極性の電圧を印加し、トナー担持体に担持されたト
ナー粒子が予め摩擦帯電された帯電極性を、現像動作時
に維持できるように、外側層の固有抵抗率を７×106Ω
・cm以上に設定した構成を提案する。To achieve the above object, the present invention applies a voltage having the same polarity as the charging polarity of toner particles to a conductor of a toner carrier to reverse develop an electrostatic latent image, and the toner carried on the toner carrier is The specific resistance of the outer layer is 7 × 10 6 Ω so that the particles can maintain the charging polarity pre-frictionally charged during the developing operation.
・ Propose a configuration set to cm or higher.
実施例 以下、本発明の実施例を図面に従って説明し、併せて上
述した従来の欠点について図面を参照しながらその詳細
を明らかにする。Embodiments Embodiments of the present invention will be described below with reference to the drawings, and the details of the above-mentioned conventional defects will be clarified with reference to the drawings.
第１図は本発明一実施例の現像装置100を用いた作像装
置の一例を示し、この現像装置100は、現像ローラ４と
して構成されたトナー担持体を有し、かかる現像装置の
タンク１内にはトナー（一成分系現像剤）２が収容され
ている。トナー２は磁性トナーであっても非磁性トナー
であってもよいが、図の例では非磁性トナーであるとす
る。FIG. 1 shows an example of an image forming apparatus using a developing device 100 according to an embodiment of the present invention. The developing device 100 has a toner carrier configured as a developing roller 4, and a tank 1 of such a developing device. A toner (one-component developer) 2 is contained therein. The toner 2 may be a magnetic toner or a non-magnetic toner, but is assumed to be a non-magnetic toner in the illustrated example.
タンク１内のトナー２はアジテータ13によって反時計方
向に回転する供給ローラ３に向けて押圧され、このロー
ラ３の搬送作用によって現像ローラ４に供給される。現
像ローラ４は、電源20によりバイアス電圧を印加される
導電体14と、その外側に位置していて、導電体14に固定
された外側層24とを備え、外側層24はたとえば剛体また
は弾性材等から成る。また図示した導電体14は現像ロー
ラ４の芯材としての用もなす。この現像ローラ４は第１
図における反時計方向に回転駆動され、当該ローラ４に
供給されたトナーは現像ローラ４に圧接されたブレード
状のトナー層厚規制部材５によって層厚を規制される。The toner 2 in the tank 1 is pressed by the agitator 13 toward the supply roller 3 which rotates counterclockwise, and is supplied to the developing roller 4 by the conveying action of the roller 3. The developing roller 4 includes a conductor 14 to which a bias voltage is applied by a power source 20 and an outer layer 24 that is located outside the conductor and is fixed to the conductor 14. The outer layer 24 is, for example, a rigid body or an elastic material. Etc. The illustrated conductor 14 also serves as a core material of the developing roller 4. This developing roller 4 is the first
The toner that is rotationally driven counterclockwise in the figure and is supplied to the roller 4 is regulated in layer thickness by a blade-shaped toner layer thickness regulating member 5 that is pressed against the developing roller 4.
またトナー２のトナー粒子は規制部材５との摩擦によっ
て、現像ローラ４の導電体14に印加されたバイアス電圧
の極性と同極性に帯電される。この極性は正または負の
いずれであってもよいが、本例では説明の便宜上、負で
あるとする。Further, the toner particles of the toner 2 are charged to the same polarity as the bias voltage applied to the conductor 14 of the developing roller 4 due to the friction with the regulation member 5. This polarity may be either positive or negative, but in this example, it is assumed to be negative for convenience of explanation.
規制部材５を通過した層厚規制後のトナーは薄層をなし
て現像ローラ４の外側層上に担持されつつ搬送され、潜
像担持体（図の例ではドラム状に形成され、矢印Ａ方向
に回転する感光体６）と現像ローラ４との対向領域、す
なわち現像領域Ｄに運ばれる。The toner, which has passed through the regulating member 5 and whose layer thickness has been regulated, is conveyed while being carried as a thin layer on the outer layer of the developing roller 4, and is formed as a latent image carrier (formed in a drum shape in the example of the drawing, in the direction of arrow A). It is conveyed to the developing area D, that is, the area where the photoconductor 6) rotating to the developing roller 4 and the developing roller 4 face each other.
感光体６はアースされたドラム状の導電性基体16とその
外側の感光層26を有し、その表面が現像ローラ４に接触
または近接して位置している。感光体６はその感光層26
が現像に先立ち帯電チャージャ７によってトナーの帯電
極性と同極性、すなわち負極性に均一に帯電される。次
いで露光部21にて原稿または発光装置からの光Ｌを照射
される。現像装置100を通常の電子複写機に用いたとき
は、光Ｌは原稿からの透過ないしは反射光であり、LED
アレイを用いたプリンタやレーザプリンタ等の場合に
は、LEDアレイないしはレーザ装置等の発光装置からの
ビームである。感光体表面に光Ｌが照射されることによ
り公知の如くこの表面に静電潜像が形成される。The photosensitive member 6 has a grounded drum-shaped conductive substrate 16 and a photosensitive layer 26 outside thereof, and the surface thereof is positioned in contact with or in proximity to the developing roller 4. Photoreceptor 6 has its photosensitive layer 26
Prior to the development, the charging charger 7 uniformly charges the toner with the same polarity as the charging polarity of the toner, that is, the negative polarity. Then, the exposure unit 21 irradiates the original or the light L from the light emitting device. When the developing device 100 is used in an ordinary electronic copying machine, the light L is the light transmitted or reflected from the document, and the light L
In the case of a printer using an array, a laser printer, or the like, it is a beam from a light emitting device such as an LED array or a laser device. By irradiating the surface of the photoconductor with light L, an electrostatic latent image is formed on this surface as is well known.
この潜像は光を強く当てられ、したがって感光層26の電
荷が消失し、あるいはその表面電位の絶対値が低下した
感光体部分と、光を当てられず、またはその光強度が弱
く、したがって負の電位が高く保たれた感光体部分とに
よって形成されるものであり、電荷が消失し、あるいは
表面電位の絶対値が低下した前者の部分が静電潜像であ
るとし、電位が高く保たれた後者の部分が地肌部である
とする。This latent image is strongly exposed to light, and therefore, the photoconductor portion in which the charge of the photosensitive layer 26 disappears or the absolute value of the surface potential thereof is reduced, and the latent image is not exposed to light or its light intensity is weak and therefore negative. Is formed by the photoconductor part whose potential is kept high, and the former part where the charge disappears or the absolute value of the surface potential has decreased is the electrostatic latent image, and the potential is kept high. It is assumed that the latter part is the background part.
上記静電潜像が現像領域Ｄに至ると、同じくここに運ば
れた摩擦帯電トナーによって潜像が可視像化される。よ
り詳しく言えば、感光体上の表面電位の高い地肌部では
なく、表面電位の低い静電潜像に、摩擦帯電されたトナ
ー粒子が付着する。これは、現像ローラ４の導電体14に
トナー粒子の帯電極性と同極性の電圧を印加することに
より生ずる電界の作用によって起こる現象であり、これ
が静電潜像の反転現像である。When the electrostatic latent image reaches the developing area D, the latent image is visualized by the triboelectrically charged toner which is also carried there. More specifically, the triboelectrically charged toner particles adhere to the electrostatic latent image having a low surface potential, not to the background portion having a high surface potential on the photoconductor. This is a phenomenon caused by the action of an electric field generated by applying a voltage having the same polarity as the charging polarity of the toner particles to the conductor 14 of the developing roller 4, and this is the reversal development of the electrostatic latent image.
上述のように、第１図に示した現像装置100は、現像ロ
ーラ４の外側層24上に薄層状態で担持された摩擦帯電ト
ナーによって、感光体６に形成された静電潜像を可視像
化し、その際、静電潜像を反転現像すべく、現像ローラ
４の導電体14にトナー粒子の帯電極と同極性の電圧が印
加される。As described above, the developing device 100 shown in FIG. 1 can develop the electrostatic latent image formed on the photoconductor 6 by the triboelectrically charged toner carried in the thin layer state on the outer layer 24 of the developing roller 4. A voltage having the same polarity as that of the toner particle strip electrode is applied to the conductor 14 of the developing roller 4 in order to visualize and electrostatically reverse develop the electrostatic latent image.
現像装置100によって反転現像された可視像は、転写チ
ャージャ８によって転写紙９上に転写される。転写チャ
ージャ８のチャージワイヤには正極性の電圧が印加さ
れ、これにより負に帯電したトナーが感光体から転写紙
側に移される。転写後の感光体はクリーニング装置10に
よって残存するトナーを清掃され、図示していない除電
ランプや除電チャージャ等から成る除電装置によって除
電作用を受ける。The visible image subjected to reversal development by the developing device 100 is transferred onto the transfer paper 9 by the transfer charger 8. A positive voltage is applied to the charge wire of the transfer charger 8, whereby negatively charged toner is transferred from the photoconductor to the transfer paper side. After the transfer, the cleaning device 10 cleans the remaining toner on the photoconductor, and the static elimination device (not shown) such as a static elimination lamp or a static elimination charger removes the static electricity.
上述のように静電潜像が反転現像されるが、従来は第１
図に示した如き現像装置により反転現像を行おうとした
とき、感光体上の静電潜像以外の地肌部にまでトナーが
多量に付着し、これによって可視像が不鮮明となった
り、感光体表面の全面にトナーが付着して所定の現像を
行えない恐れがあった。As described above, the electrostatic latent image is reverse-developed.
When reversal development is attempted by the developing device as shown in the figure, a large amount of toner adheres to the background portion other than the electrostatic latent image on the photoconductor, which makes the visible image unclear or the photoconductor There is a possibility that toner adheres to the entire surface and predetermined development cannot be performed.
これについて本発明者が検討したところ、現像ローラ４
の外側層24の電気抵抗の高低によって反転現像の可否が
決まることが明らかとなった。すなわち、従来の現像ロ
ーラ外側層の電気抵抗値は低く設定され、これにより、
現像領域Ｄにて静電潜像以外の地肌部に対向して位置す
るトナー粒子の電荷が失われ、あるいはその極性が反転
してしまい、その結果このトナー粒子が地肌部に付着
し、これによって可視像が不鮮明となっていたのであ
る。このようにトナー粒子の電荷が失われたり、その極
性が反転する理由は次のように推測される。When the present inventor examined this, the developing roller 4
It was revealed that whether or not the reversal development is possible depends on the level of the electric resistance of the outer layer 24. That is, the electric resistance value of the conventional developing roller outer layer is set to be low, whereby
In the developing area D, the electric charge of the toner particles located opposite to the background portion other than the electrostatic latent image is lost, or the polarity thereof is reversed, and as a result, the toner particles adhere to the background portion, which causes The visible image was unclear. The reason why the charge of the toner particles is lost and the polarity thereof is reversed is presumed as follows.
第２図は現像領域における感光体６と現像ローラ４を模
式的に示す説明図であり、第１図を参照して先に説明し
た如く、現像ローラ４の導電体14には電源20によって負
極性のバイアス電圧が印加され、感光体６と現像ローラ
４との間に、印加電圧極性と同極性の負に摩擦帯電され
た直径約10μ程のトナー粒子Ｔが挟まれている。感光体
６の基体16はアースされ、感光層26には「−」の符号で
示したように負側に表面電位の高い地肌部Ｘと、これよ
りも表面電位が低い静電潜像Ｙが形成されている。静電
潜像の表面電位は零ボルトであってもよい。FIG. 2 is an explanatory view schematically showing the photosensitive member 6 and the developing roller 4 in the developing area. As described above with reference to FIG. Bias voltage is applied, and toner particles T having a diameter of about 10 μm, which are negatively charged by friction and have the same polarity as the applied voltage, are sandwiched between the photoconductor 6 and the developing roller 4. The substrate 16 of the photoconductor 6 is grounded, and the photosensitive layer 26 is provided with a background portion X having a high surface potential on the negative side and an electrostatic latent image Y having a lower surface potential than that, as indicated by the symbol "-". Has been formed. The surface potential of the electrostatic latent image may be zero volts.
現像領域に至ったトナー粒子のうち、静電潜像Ｙに対向
したトナー粒子は、その帯電極性が負であり、導電体14
にはこれと同じ極性のバイアス電圧が印加されているの
で、かかるトナーは静電潜像Ｙに静電的に付着する。一
方、地肌部Ｘに対峙したトナー粒子Ｔは、この地肌部の
電荷に基く高電界（たとえば約10乃至100kv/cm）の作用
で、第２図に「＋」「−」の記号を記入した如く分極
し、その負の電荷が現像ローラ４の外側層24に対向す
る。Among the toner particles reaching the developing area, the toner particles facing the electrostatic latent image Y have a negative charging polarity, and the conductor 14
Is applied with a bias voltage of the same polarity, the toner is electrostatically attached to the electrostatic latent image Y. On the other hand, the toner particles T facing the background portion X are marked with "+" and "-" symbols in FIG. 2 by the action of a high electric field (for example, about 10 to 100 kv / cm) based on the electric charge of the background portion. Thus, the negative charges face the outer layer 24 of the developing roller 4.
このとき従来の現像ローラ４においては、その外側層24
の電気抵抗値が低く設定されていたため、トナー粒子Ｔ
の負の電荷が第４図に鎖線矢印で示す如く外側層24にリ
ークし、よって地肌部Ｘに対向したトナー粒子Ｔの帯電
極性が負から正に逆転する。このように正極性に反転し
たトナー粒子は、これと逆極性の地肌部Ｘに付着し、完
成した可視像が不鮮明とならざるを得ない。感光体に形
成された静電潜像Ｙに対向するトナー粒子の電荷の一部
もリークすると考えられるが、このトナー粒子極性は、
普通、逆転するまでには至らない。At this time, in the conventional developing roller 4, the outer layer 24
Since the electric resistance value of the toner particles was set low, the toner particles T
The negative electric charge of the toner particles leaks to the outer layer 24 as shown by the chain line arrow in FIG. 4, so that the charging polarity of the toner particles T facing the background portion X is reversed from negative to positive. In this way, the toner particles inverted to the positive polarity adhere to the background portion X having a polarity opposite to that of the toner particles, and the completed visible image is inevitable. It is considered that a part of the charge of the toner particles facing the electrostatic latent image Y formed on the photoconductor leaks, but the polarity of the toner particles is
Usually, it doesn't reach the point where it reverses.
そこで、本例の現像装置においては、現像動作時に静電
潜像Ｙ以外の地肌部Ｘに対向したトナー粒子の負電荷が
現像ローラ４の外側層24にリークしてその電荷が失われ
たり、その極性が反転しないように、外側層24の電気抵
抗値を高く設定してある。このように外側層24の電気抵
抗を設定するだけで、予め摩擦帯電されたトナー粒子の
極性を現像動作時に維持でき、これによって静電潜像Ｙ
以外の地肌部Ｘにはトナー粒子が付着せず、静電潜像Ｙ
にだけトナー粒子が付着し、支障なく鮮明な可視像を得
ることが可能となる。Therefore, in the developing device of this example, the negative charge of the toner particles facing the background portion X other than the electrostatic latent image Y leaks to the outer layer 24 of the developing roller 4 during the developing operation, and the charge is lost. The electric resistance value of the outer layer 24 is set high so that the polarity is not reversed. The polarity of the toner particles pre-frictionally charged can be maintained during the developing operation simply by setting the electric resistance of the outer layer 24 in this manner, whereby the electrostatic latent image Y is obtained.
The toner particles do not adhere to the background portion X other than the above, and the electrostatic latent image Y
The toner particles adhere only to the surface, and a clear visible image can be obtained without any trouble.
次に、第２図に示し、かつ上述した推論に至るまでの経
過と、図示した現像装置の利点を明らかにした実験例を
説明する。Next, an explanation will be given of an example of the experiment shown in FIG. 2 and leading to the above-mentioned inference and clarification of the advantages of the developing device shown.
第３図は直径20mm、長さ210mmの３本の現像ローラ4A,4
B,4Cの外側層の電気抵抗特性を表わしたグラフである。
第４図はこれら現像ローラの電気抵抗特性の測定方法を
示した模式図である。各現像ローラ4A,4B,4Cは、直径8m
mのステンレス軸の導電体14に、抵抗調節剤としての導
電性カーボンブラックを分散したシリコーン系ゴムを被
覆し、その外周面を研削して厚さ6mmのゴム層から成る
外側層24を形成した円柱状体である。このように形成さ
れた各現像ローラ4A,4B,4Cを、良く磨いた直径40mmのア
ルミニウム円柱30に当接させ、現像ローラの全体に荷重
Ｗ＝3.5kgを均一に加え、その周方向接触幅ｄを2mmとし
た。この状態で導電体14とアルミニウム円柱30との間に
電圧を印加し、ゴム層の外側層24を通る電流を読み取
り、これをグラフとして示したものが第３図である。Figure 3 shows three developing rollers 4A, 4 with a diameter of 20mm and a length of 210mm.
7 is a graph showing the electric resistance characteristics of the outer layers of B and 4C.
FIG. 4 is a schematic diagram showing a method for measuring the electric resistance characteristics of these developing rollers. Each developing roller 4A, 4B, 4C has a diameter of 8m
The stainless steel shaft conductor 14 of m was coated with silicone rubber in which conductive carbon black as a resistance modifier was dispersed, and the outer peripheral surface was ground to form an outer layer 24 consisting of a rubber layer having a thickness of 6 mm. It is a columnar body. The developing rollers 4A, 4B, 4C formed in this manner are brought into contact with a well-polished aluminum cylinder 30 having a diameter of 40 mm, and a load W = 3.5 kg is uniformly applied to the entire developing roller, and the circumferential contact width thereof. d was set to 2 mm. In this state, a voltage is applied between the conductor 14 and the aluminum cylinder 30, the current passing through the outer layer 24 of the rubber layer is read, and this is shown as a graph in FIG.
一方、潜像担持体としてドラム状基体に有機光導電体の
感光層26（第１図および第２図）を積層した直径40mmの
ドラム状感光体６を用い、これを第１図のように組付
け、48mm/secの線速で回転させて帯電チャージャ７によ
って−800Vに均一に帯電し、光Ｌによって像露光を行
い、露光された部分、すなわち静電潜像Ｙ（第２図）の
表面電位が−50Vに低下するようにした。On the other hand, as a latent image carrier, a drum-shaped photoreceptor 6 having a diameter of 40 mm, in which a photosensitive layer 26 (FIGS. 1 and 2) of an organic photoconductor is laminated on a drum-shaped substrate, is used. Assembled, rotated at a linear velocity of 48 mm / sec, uniformly charged to −800 V by the charging charger 7, imagewise exposed by the light L, and exposed portion, that is, electrostatic latent image Y (FIG. 2). The surface potential was lowered to -50V.
先ず感光体６を第１図に示した作像装置から取り外して
おき、負に帯電する非磁性トナー粒子のトナーを現像装
置100のタンク１に入れ、現像装置100のみを作動させて
現像ローラ4A,4Bまたは4C上に薄い帯電トナー層を形成
した。その帯電量を測定したところ、現像ローラ4A,4B,
4C共に−５乃至−30μc/gの電荷を有していた。First, the photoconductor 6 is detached from the image forming device shown in FIG. 1, toner of negatively charged non-magnetic toner particles is put in the tank 1 of the developing device 100, and only the developing device 100 is operated to operate the developing roller 4A. A thin charged toner layer was formed on 4B or 4C. When the charge amount was measured, the developing rollers 4A, 4B,
Both 4C had a charge of -5 to -30 μc / g.
次いで感光体６を第１図のように組込み、順次現像ロー
ラ4A,4B,4Cと組合せて各現像ローラの導電体14に負のバ
イアス電圧を印加して先に説明した態様で反転現像を行
った。Then, the photoconductor 6 is assembled as shown in FIG. 1, combined with the developing rollers 4A, 4B, and 4C in order, and a negative bias voltage is applied to the conductor 14 of each developing roller to perform the reversal development in the manner described above. It was
電気抵抗値が最も低い外側層24を有する現像ローラ4Aを
組込んだ現像装置においては、感光体６の全面にトナー
が付着し、現像ローラ4Aの導電体14へのバイアス電圧を
変えても鮮明な反転像は得られなかった。またこの感光
体６上の可視像を、転写チャージャ８によって正のコロ
ナチャージで普通紙に転写すると反転像が転写され、逆
に負のコロナチャージで同様に転写すると正像が転写さ
れた。これにより、現像動作時に地肌部Ｘ（第２図）に
対峙したトナー粒子が正極性に反転してこれが地肌部Ｘ
に付着し、静電潜像Ｙの形成された感光体部分には負に
帯電したままのトナー粒子が付着したことを理解でき
る。In the developing device incorporating the developing roller 4A having the outer layer 24 having the lowest electric resistance value, the toner adheres to the entire surface of the photoconductor 6 and is clear even if the bias voltage to the conductor 14 of the developing roller 4A is changed. No reverse image was obtained. When a visible image on the photoconductor 6 was transferred to plain paper by the transfer charger 8 with a positive corona charge, a reverse image was transferred, and when a negative corona charge was similarly transferred, a positive image was transferred. As a result, the toner particles facing the background portion X (FIG. 2) during the developing operation are reversed to the positive polarity, and this is the background portion X.
It can be understood that the toner particles remaining negatively charged adhere to the photoconductor portion on which the electrostatic latent image Y is formed.
外側層24の電気抵抗が現像ローラ4Aよりも高い現像ロー
ラ4B、および抵抗値の最も高い現像ローラ4Cを用いた各
現像装置においては、その導電体14に−400Vのバイアス
電圧を印加することにより、鮮明な反転可視像が得られ
た。但し現像ローラ4Bを組付けた現像装置により連続プ
リンタ動作を行ったところ、A4サイズの転写紙約100枚
に転写を行った程度で、現像ローラ4Aの場合と同様に感
光体表面の全面にトナー付着が発生した。これに対し現
像ローラ4Cでは5000枚以上プリンタを続けても鮮明な反
転可視像が得られた。現像ローラ4Bでは、その外側層24
を構成するゴム層の電気抵抗値が経時的に低下し、トナ
ー粒子の電荷のリークが発生するに至り、感光体の地肌
部にもトナー粒子が付着したものと考えられる。In each developing device using the developing roller 4B in which the electric resistance of the outer layer 24 is higher than the developing roller 4A, and the developing roller 4C having the highest resistance value, by applying a bias voltage of −400 V to the conductor 14. A clear inverted visible image was obtained. However, when continuous printer operation was performed with the developing device with the developing roller 4B installed, it transferred to approximately 100 sheets of A4 size transfer paper, and as with developing roller 4A, toner was applied to the entire surface of the photoconductor. Adhesion occurred. On the other hand, with the developing roller 4C, a clear inverted visible image was obtained even if the printer was continuously used for 5,000 sheets or more. In the developing roller 4B, the outer layer 24
It is considered that the electric resistance value of the rubber layer constituting the toner decreases with time, and the charge of the toner particles leaks, and the toner particles adhere to the background portion of the photoconductor.
上記実験結果が示す通り、電気抵抗の低い外側層を有す
る現像ローラ4A,4Bを用いると、初期から、あるいは極
めて短時間で現像ローラに保持されているトナー粒子の
帯電電荷が失なわれてその極性が反転し、これにより可
視像が不鮮明となることが明らかである。電気抵抗の高
い外側層を有する現像ローラ4Cを用いれば、長時間に亘
って鮮明な反転可視像が得られる。As shown by the above experimental results, when the developing rollers 4A and 4B having the outer layer having a low electric resistance are used, the charged electric charge of the toner particles held on the developing roller is lost from the initial stage or in an extremely short time. It is clear that the polarities are reversed, which causes the visible image to be blurred. If the developing roller 4C having the outer layer having high electric resistance is used, a clear inverted visible image can be obtained for a long time.
上述した実験以外にも各種実験を繰返したところ、外側
層24の電気抵抗値としては、第４図に示す測定方法にお
いて1000Vのバイアス電圧を印加したとき、少なくとも1
06Ω以上、好ましくは107Ω以上の抵抗値Ｒを示すもの
が鮮明な可視像を得る上で好ましかった。第４図に示す
測定方法では、アルミニウム円柱30に接する外側層24の
面積Ｓは、現像ローラ長さが210mm、ｄ＝2mmであるから
Ｓ＝２×210mm2となり、その厚さ（ｌ）は6mmである。
したがって外側層24の固有抵抗率をρとしたとき、Ｒ＝
ρ×l/sであるから、Ｒ＝106Ω以上であるには、 となり、ρ＝７×106Ω・cm以上である。同じく、好ま
しくはρ＝７×107Ω・cm以上（Ｒ＝107Ω以上）であ
る。When various experiments other than the above-described experiment were repeated, the electric resistance value of the outer layer 24 was found to be at least 1 when a bias voltage of 1000 V was applied in the measuring method shown in FIG.
Those showing a resistance value R of 0 6 Ω or more, preferably 10 7 Ω or more were preferable for obtaining a clear visible image. In the measuring method shown in FIG. 4, the area S of the outer layer 24 in contact with the aluminum cylinder 30 is S = 2 × 210 mm 2 because the developing roller length is 210 mm and d = 2 mm, and the thickness (l) is 6 mm.
Therefore, when the resistivity of the outer layer 24 is ρ, R =
Since ρ × l / s, if R = 10 6 Ω or more, Therefore, ρ = 7 × 10 6 Ω · cm or more. Similarly, it is preferably ρ = 7 × 10 7 Ω · cm or more (R = 10 7 Ω or more).
上述した事実から判るように、第１図に示した現像装置
100において、現像ローラ４に担持されたトナー粒子が
予め摩擦帯電された帯電極性を、現像動作時に維持でき
るように、現像ローラ４の外側層24の固有抵抗率を７×
106Ω・cm以上に設定すれば、長期に亘って高品質な可
視像化を得ることができる。As can be seen from the above facts, the developing device shown in FIG.
At 100, the specific resistance of the outer layer 24 of the developing roller 4 is set to 7 × so that the toner particles carried on the developing roller 4 can maintain the charging polarity pre-frictionally charged during the developing operation.
If it is set to 10 6 Ω · cm or more, a high quality visible image can be obtained for a long period of time.
以上、トナー担持体が現像ローラとして構成され、潜像
担持体がドラム状の感光体として構成された場合の実施
例を説明したが、トナー担持体がスリーブないしはベル
ト状に構成され、また潜像担持体がベルト状の感光体、
あるいは感光体以外の誘電体ドラムまたは誘電体ベルト
等から構成されているときも本発明を適用できる。また
図示した形式以外の現像装置、たとえばトナー担持体上
の磁性トナーを磁力を利用して搬送する装置、トナー担
持体が潜像担持体に対して離間した現像装置、ファクシ
ミリ等の作像装置における現像装置等に広く適用可能で
ある。The embodiment in which the toner bearing member is configured as a developing roller and the latent image bearing member is configured as a drum-shaped photosensitive member has been described above. However, the toner bearing member is configured as a sleeve or a belt, and a latent image is also used. The carrier is a belt-shaped photoreceptor,
Alternatively, the present invention can be applied to a case where the photosensitive drum is composed of a dielectric drum or a dielectric belt other than the photoconductor. Further, in a developing device other than the illustrated type, for example, a device that conveys magnetic toner on a toner carrier by using magnetic force, a developing device in which the toner carrier is separated from the latent image carrier, or an image forming apparatus such as a facsimile machine. It is widely applicable to developing devices and the like.
効果 本発明によれば、トナー担持体の外側層の固有抵抗率
を、トナー粒子の帯電極性を維持できるように設定する
という簡単な構成によって、反転現像が可能となり、鮮
明な可視像を得ることが可能となった。Effects According to the present invention, reversal development is possible and a clear visible image is obtained with a simple configuration in which the specific resistance of the outer layer of the toner carrier is set so as to maintain the charge polarity of the toner particles. It has become possible.
第１図は本発明に係る現像装置を有する作像装置の一例
を示す概略断面図、第２図は反転現像時の状況と、従来
の欠点の発生原因を説明する模式図、第３図は実験に用
いた現像ローラ外側層の電気抵抗特性を示すグラフ、第
４図は各現像ローラの電気抵抗値を測定する方法を示し
た説明図である。 ２……トナー、14……導電体 24……外側層、100……現像装置 Ｔ……トナー粒子FIG. 1 is a schematic cross-sectional view showing an example of an image forming apparatus having a developing device according to the present invention, FIG. 2 is a schematic diagram for explaining the situation at the time of reversal development, and a conventional defect cause, and FIG. FIG. 4 is a graph showing the electric resistance characteristic of the outer layer of the developing roller used in the experiment, and FIG. 4 is an explanatory view showing a method for measuring the electric resistance value of each developing roller. 2 ... toner, 14 ... conductor 24 ... outer layer, 100 ... developing device T ... toner particles
Claims (1)
えたトナー担持体を具備し、該担持体の外側層上に薄層
状態で担持された摩擦帯電トナーによって、潜像担持体
に形成された静電潜像を可視像化する現像装置におい
て、 静電潜像を反転現像すべくトナー担持体の導電体にトナ
ー粒子の帯電極性と同極性の電圧を印加し、トナー担持
体に担持されたトナー粒子が予め摩擦帯電された帯電極
性を、現像動作時に維持できるように、前記外側層の固
有抵抗率を７×106Ω・cm以上に設定したことを特徴と
する現像装置。1. A latent image carrier comprising a toner carrier comprising a conductor and an outer layer located on the outer side of the conductor, and a triboelectrically charged toner carried in a thin layer on the outer layer of the carrier. In a developing device that visualizes the electrostatic latent image formed on the toner carrier, a voltage having the same polarity as the charging polarity of the toner particles is applied to the conductor of the toner carrier to reverse develop the electrostatic latent image, The development is characterized in that the specific resistance of the outer layer is set to 7 × 10 6 Ω · cm or more so that the toner particles carried on the body can be preliminarily triboelectrically charged to maintain the charging polarity during the developing operation. apparatus.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP60257540A JPH0731454B2 (en) | 1985-11-19 | 1985-11-19 | Development device |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP60257540A JPH0731454B2 (en) | 1985-11-19 | 1985-11-19 | Development device |
Related Child Applications (2)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP11118096A Division JPH08272213A (en) | 1996-04-08 | 1996-04-08 | Developing device |
| JP2781698A Division JPH10293455A (en) | 1998-01-26 | 1998-01-26 | Developing device |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS62118372A JPS62118372A (en) | 1987-05-29 |
| JPH0731454B2 true JPH0731454B2 (en) | 1995-04-10 |
Family
ID=17307699
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP60257540A Expired - Fee Related JPH0731454B2 (en) | 1985-11-19 | 1985-11-19 | Development device |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH0731454B2 (en) |
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP2874015A1 (en) | 2013-11-13 | 2015-05-20 | Canon Kabushiki Kaisha | Developer carrying member, developing assembly, process cartridge, and image forming apparatus |
| EP2874011A1 (en) | 2013-11-13 | 2015-05-20 | Canon Kabushiki Kaisha | Image forming apparatus |
| EP2874010A1 (en) | 2013-11-13 | 2015-05-20 | Canon Kabushiki Kaisha | Image forming apparatus |
| EP2874014A1 (en) | 2013-11-13 | 2015-05-20 | Canon Kabushiki Kaisha | Developer carrying member, developing assembly, process cartridge, and image forming apparatus |
| US9405217B2 (en) | 2014-06-30 | 2016-08-02 | Canon Kabushiki Kaisha | Developer carrying member and image forming apparatus |
Families Citing this family (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS6420581A (en) * | 1987-07-16 | 1989-01-24 | Minolta Camera Kk | Developing device |
| US5076201A (en) * | 1989-03-16 | 1991-12-31 | Fujitsu Limited | Developing device used in electrophotographic field and method of producing developing roller incorporated therein |
| US5057871A (en) * | 1989-03-16 | 1991-10-15 | Fujitsu Limited | Developing device having a conductive porous toner-removing roller |
| US5097294A (en) * | 1989-03-20 | 1992-03-17 | Fujitsu Limited | Developing device used in electrophotographic field with a one-component developer and having a blade member for developer layer thickness regulation |
| JP3014052B2 (en) * | 1989-05-11 | 2000-02-28 | 富士通株式会社 | One-component developing device |
| US5068691B1 (en) * | 1989-06-01 | 1995-01-24 | Fujitsu Ltd | Developing device with a controllable pressure release for the developing roller |
| AU619686B2 (en) * | 1989-06-21 | 1992-01-30 | Fuji Xerox Co., Ltd. | Developing device used in electrophotographic field |
| JPH0363677A (en) * | 1989-08-01 | 1991-03-19 | Fujitsu Ltd | Developing device with one-component toner |
| JPH11160997A (en) * | 1997-11-28 | 1999-06-18 | Nec Niigata Ltd | Electrophotographic developing device |
| JP7020853B2 (en) | 2017-10-13 | 2022-02-16 | キヤノン株式会社 | Developing equipment and image forming equipment |
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5937830B2 (en) * | 1976-05-31 | 1984-09-12 | 株式会社日立製作所 | Charge latent image developing device |
| JPS5926025B2 (en) * | 1978-06-23 | 1984-06-23 | 株式会社日立製作所 | electrostatic recording device |
| JPS5546768A (en) * | 1978-09-29 | 1980-04-02 | Ricoh Co Ltd | Electrostatic latent image development unit |
| JPS5614242A (en) * | 1979-07-16 | 1981-02-12 | Canon Inc | Electrostatic developing method |
| JPS56125776A (en) * | 1980-03-08 | 1981-10-02 | Mita Ind Co Ltd | Developing device of electrostatic latent image |
| JPS56144452A (en) * | 1980-04-14 | 1981-11-10 | Hitachi Ltd | Electrophotographic recorder |
| JPS5846346A (en) * | 1981-09-14 | 1983-03-17 | Ricoh Co Ltd | Composite electrophotographic receptor |
| JPS5858568A (en) * | 1981-10-02 | 1983-04-07 | Canon Inc | Developing device |
| JPS5891476A (en) * | 1981-11-26 | 1983-05-31 | Ricoh Co Ltd | Developing device |
| JPS58114048A (en) * | 1981-12-28 | 1983-07-07 | Konishiroku Photo Ind Co Ltd | Controlling device of picture density |
| JPS58144863A (en) * | 1982-02-23 | 1983-08-29 | Toshiba Corp | Magnetic brush developing apparatus |
| JPS58153972A (en) * | 1982-03-10 | 1983-09-13 | Toshiba Corp | Developing device |
| JPS592060A (en) * | 1982-06-28 | 1984-01-07 | Fujitsu Ltd | Developing device |
| JPS6045272A (en) * | 1983-08-23 | 1985-03-11 | Fuji Xerox Co Ltd | Developing device |
| JPS6080875A (en) * | 1983-10-11 | 1985-05-08 | Fuji Xerox Co Ltd | Non-magnetic one-component developing device |
-
1985
- 1985-11-19 JP JP60257540A patent/JPH0731454B2/en not_active Expired - Fee Related
Cited By (9)
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|---|---|---|---|---|
| EP2874015A1 (en) | 2013-11-13 | 2015-05-20 | Canon Kabushiki Kaisha | Developer carrying member, developing assembly, process cartridge, and image forming apparatus |
| EP2874011A1 (en) | 2013-11-13 | 2015-05-20 | Canon Kabushiki Kaisha | Image forming apparatus |
| EP2874010A1 (en) | 2013-11-13 | 2015-05-20 | Canon Kabushiki Kaisha | Image forming apparatus |
| EP2874014A1 (en) | 2013-11-13 | 2015-05-20 | Canon Kabushiki Kaisha | Developer carrying member, developing assembly, process cartridge, and image forming apparatus |
| US9134649B2 (en) | 2013-11-13 | 2015-09-15 | Canon Kabushiki Kaisha | Image forming apparatus |
| US9261811B2 (en) | 2013-11-13 | 2016-02-16 | Canon Kabushiki Kaisha | Developer carrying member, developing assembly, process cartridge, and image forming apparatus |
| US9261814B2 (en) | 2013-11-13 | 2016-02-16 | Canon Kabushiki Kaisha | Developer carrying member, developing assembly, process cartridge, and image forming apparatus |
| US9298128B2 (en) | 2013-11-13 | 2016-03-29 | Canon Kabushiki Kaisha | Image forming apparatus |
| US9405217B2 (en) | 2014-06-30 | 2016-08-02 | Canon Kabushiki Kaisha | Developer carrying member and image forming apparatus |
Also Published As
| Publication number | Publication date |
|---|---|
| JPS62118372A (en) | 1987-05-29 |
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