JPH08240972A - Developing device - Google Patents
Developing deviceInfo
- Publication number
- JPH08240972A JPH08240972A JP4306895A JP4306895A JPH08240972A JP H08240972 A JPH08240972 A JP H08240972A JP 4306895 A JP4306895 A JP 4306895A JP 4306895 A JP4306895 A JP 4306895A JP H08240972 A JPH08240972 A JP H08240972A
- Authority
- JP
- Japan
- Prior art keywords
- toner
- developing
- developing sleeve
- developer
- sleeve
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Withdrawn
Links
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- Developing For Electrophotography (AREA)
- Dry Development In Electrophotography (AREA)
Abstract
Description
【０００１】[0001]
【産業上の利用分野】本発明は、電子写真法や静電記録
法によって、磁性キャリアとトナーとからなる二成分現
像剤を用いて、像担持体上に形成された静電潜像を現像
する複写機やプリンタ等の現像装置に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention develops an electrostatic latent image formed on an image bearing member by a two-component developer composed of a magnetic carrier and a toner by an electrophotographic method or an electrostatic recording method. The present invention relates to a developing device such as a copying machine or a printer.
【０００２】[0002]
【従来の技術】従来より、像担持体上に静電潜像を形成
し、この静電潜像に対して現像装置によりトナーと磁性
キャリアとからなる二成分現像剤を供給して前記静電潜
像を現像し、この現像によって形成されたトナー像を被
転写材に転写させる電子写真法や静電記録法を用いた複
写機やプリンタ等が知られている。2. Description of the Related Art Conventionally, an electrostatic latent image is formed on an image bearing member, and a two-component developer composed of toner and magnetic carrier is supplied to the electrostatic latent image by a developing device. There is known a copying machine, a printer, or the like that uses an electrophotographic method or an electrostatic recording method, which develops a latent image and transfers the toner image formed by the development to a transfer material.
【０００３】この現像装置は、静電潜像が形成されて回
転する像担持体に対向して配設され、上記二成分現像剤
を吸着して現像領域へ搬送する現像剤担持体と、該現像
剤担持体上に吸着されて現像領域へ搬送される現像剤の
層厚を規制する層厚規制部材とを備えている。また、現
像剤担持体は、通常、回転する導電性非磁性の現像スリ
ーブと、該現像スリーブの内部に配設された固定のマグ
ネットロールとで構成される。層厚規制部材は非磁性材
料により形成される。現像剤は、現像スリーブ上にマグ
ネットロールの磁力によって保持され、現像スリーブの
回転によって、若しくは現像スリーブとマグネットロー
ルとの相対的な回転によって攪拌されながら搬送され、
現像領域において、現像剤が像担持体表面に近接あるい
は接触して、像担持体の表面上に形成された静電潜像を
現像する。This developing device is disposed so as to face an image bearing member on which an electrostatic latent image is formed and rotates, and a developer bearing member that adsorbs the two-component developer and conveys it to a developing area. And a layer thickness regulating member that regulates the layer thickness of the developer that is adsorbed on the developer carrier and conveyed to the developing area. The developer carrying member is usually composed of a rotating conductive non-magnetic developing sleeve and a fixed magnet roll arranged inside the developing sleeve. The layer thickness regulating member is made of a non-magnetic material. The developer is held on the developing sleeve by the magnetic force of the magnet roll, and is conveyed while being stirred by the rotation of the developing sleeve or the relative rotation of the developing sleeve and the magnet roll,
In the developing area, the developer approaches or contacts the surface of the image carrier to develop the electrostatic latent image formed on the surface of the image carrier.
【０００４】[0004]
【発明が解決しようとする課題】ところで、上記の様な
現像装置においては、マグネットロールの磁力パターン
にしたがって現像剤が現像スリーブ上において穂立ちが
形成されたり現像スリーブに密着した状態になったりし
ながら搬送されるため、キャリアからトナーが剥がれや
すく、剥がれたトナーが現像装置の周辺に飛散し、現像
装置等を汚してしまうという問題がある。By the way, in the developing device as described above, the developer may form a spike on the developing sleeve or become in a state of being in close contact with the developing sleeve according to the magnetic force pattern of the magnet roll. Since the toner is conveyed while being conveyed, there is a problem in that the toner is easily peeled off from the carrier, and the peeled toner scatters around the developing device, thereby contaminating the developing device and the like.
【０００５】本発明は、上記事情に鑑み、現像スリーブ
上でのトナーの飛散を抑制することができる現像装置を
提供することを目的とする。In view of the above circumstances, it is an object of the present invention to provide a developing device capable of suppressing the toner scattering on the developing sleeve.
【０００６】[0006]
【課題を解決するための手段】本発明の現像装置は、上
記目的を達成するため、回転する現像スリーブと該現像
スリーブの内部に配設された固定マグネットとからな
り、静電潜像が形成される像担持体に対向して配設さ
れ、磁性キャリアとトナーとからなる二成分現像剤を前
記現像スリーブ上に吸着して現像領域へ搬送する現像剤
担持体を備えて成る現像装置において、前記現像スリー
ブに所定の間隔をおいて対向させて、該現像スリーブ上
のトナーに対して該現像スリーブ側に向けて静電気力が
作用するように電圧が印加されるトナー飛散抑制電極が
配設されていることを特徴とする。In order to achieve the above-mentioned object, a developing device of the present invention comprises a rotating developing sleeve and a fixed magnet disposed inside the developing sleeve to form an electrostatic latent image. And a developing device provided with a developer carrying member for adsorbing a two-component developer composed of a magnetic carrier and a toner onto the developing sleeve and conveying the two-component developer to a developing area. A toner scattering suppressing electrode is provided facing the developing sleeve at a predetermined interval, and a voltage is applied to the toner on the developing sleeve so that an electrostatic force acts on the toner toward the developing sleeve. It is characterized by
【０００７】ここで、上記本発明の現像装置において、
前記トナー飛散抑制電極は、前記現像剤担持体の軸方向
に沿って延びると共に該軸方向に沿って複数の小領域に
分割され、各小領域毎に前記電圧を印加制御可能に構成
することが好ましい。また、前記トナー飛散抑制電極
は、前記現像剤担持体上の磁極に対向して配設すること
が好ましい。Here, in the developing device of the present invention,
The toner scattering suppression electrode extends along the axial direction of the developer carrying member and is divided into a plurality of small regions along the axial direction, and the voltage can be controlled to be applied to each small region. preferable. Further, it is preferable that the toner scattering suppression electrode is arranged so as to face a magnetic pole on the developer carrying member.
【０００８】前記トナー飛散抑制電極は、現像スリーブ
上に吸着されて現像領域へ搬送される現像剤の層厚を規
制する層厚規制部材によって構成することもできる。The toner-scattering suppressing electrode may be composed of a layer-thickness regulating member that regulates the layer thickness of the developer adsorbed on the developing sleeve and conveyed to the developing area.
【０００９】[0009]
【作用】本発明の画像形成装置は、上記のように、現像
領域の近傍において現像スリーブに所定の間隔をおいて
対向させて、現像スリーブ上のトナーに対して現像スリ
ーブ側に向けて静電気力が作用するように電圧が印加さ
れるトナー飛散抑制電極が配設されているので、この電
極に電圧を印加することにより形成される電界の作用に
よりトナーが現像スリーブ側に向けて押し付けられ、現
像スリーブ上の現像剤層の上層部にはトナーが少なくな
る。このため、現像スリーブの回転に伴う現像剤の穂立
ち等の動きによって発生するトナーの飛散を抑制するこ
とができる。In the image forming apparatus of the present invention, as described above, the toner on the developing sleeve is opposed to the developing sleeve at a predetermined interval in the vicinity of the developing area, and electrostatic force is applied to the toner on the developing sleeve toward the developing sleeve. Since a toner scattering suppression electrode to which a voltage is applied is provided so that the voltage acts on the toner, the toner is pressed toward the developing sleeve by the action of the electric field formed by applying a voltage to this electrode, There is less toner in the upper layer portion of the developer layer on the sleeve. For this reason, it is possible to suppress the scattering of the toner which is caused by the movement of the developer such as the spikes of the developer due to the rotation of the developing sleeve.
【００１０】上記トナー飛散抑制電極を、像担持体上に
形成された静電潜像に応じて電圧が印加されるように構
成すると、例えば非画像部、つまり像担持体上に形成さ
れた静電潜像領域以外の領域に対する部分についてのみ
電圧を印加することにより、静電潜像の現像に悪影響を
及ぼすこと無く良好にトナーの飛散防止を図ることがで
きる。When the toner scattering suppression electrode is constructed so that a voltage is applied according to the electrostatic latent image formed on the image carrier, for example, a non-image portion, that is, a static image formed on the image carrier is formed. By applying the voltage only to the portion other than the electric latent image region, it is possible to prevent the toner from scattering without adversely affecting the development of the electrostatic latent image.
【００１１】また、上記トナー飛散抑制電極を、現像剤
担持体の軸方向に沿って延びると共にその軸方向に沿っ
て複数の小領域に分割し、各小領域毎に電圧を印加制御
可能に構成した場合には、例えば現像スリーブの軸方向
において静電潜像に対応する領域以外の領域、例えば現
像スリーブの軸方向長さがＡ３用紙の幅方向の長さに対
応している場合において静電潜像がＡ４用紙の幅方向の
長さに対応する領域に形成されている場合、そのＡ４用
紙の幅方向の長さに対応する領域以外の領域に対応する
電極の小領域についてのみ電圧を印加することにより、
静電潜像の現像に悪影響を及ぼすこと無く良好にトナー
の飛散防止を図ることができる。Further, the toner scattering suppression electrode extends along the axial direction of the developer carrying member and is divided into a plurality of small regions along the axial direction so that the voltage can be controlled to be applied to each small region. In this case, for example, in the area other than the area corresponding to the electrostatic latent image in the axial direction of the developing sleeve, for example, in the case where the axial length of the developing sleeve corresponds to the widthwise length of the A3 sheet, the electrostatic charge is generated. When the latent image is formed in the area corresponding to the length of the A4 paper in the width direction, the voltage is applied only to the small area of the electrode corresponding to the area other than the area corresponding to the length of the A4 paper in the width direction. By doing
It is possible to effectively prevent the toner from scattering without adversely affecting the development of the electrostatic latent image.
【００１２】また、トナー飛散抑制電極を、固定マグネ
ット上の磁極に対向して配設した場合には、磁性上では
トナーが穂立ちするのでトナーの飛散が生じやすいが、
このトナーの飛散が生じやすい領域においてその穂立ち
の隙間からトナーが現像スリーブ側に有効に移動し、特
に良好にトナーの飛散防止を図ることができる。更に、
トナー飛散抑制電極を、層厚規制部材によって構成した
場合には、別途の電極部材を配設する必要がなく、従っ
て構成の複雑化を伴うこと無くトナーの飛散防止を図る
ことができる。When the toner-scattering suppressing electrode is arranged so as to face the magnetic pole on the fixed magnet, the toner scatters magnetically, so that the toner tends to scatter.
In the region where the toner is likely to be scattered, the toner is effectively moved to the developing sleeve side through the gap between the spikes, so that the toner can be particularly effectively prevented from being scattered. Furthermore,
When the toner-scattering suppressing electrode is composed of the layer thickness regulating member, it is not necessary to dispose a separate electrode member, and therefore toner scattering can be prevented without complicating the structure.
【００１３】[0013]
【実施例】以下、図面を参照しながら、本発明の実施例
を詳細に説明する。図１は本発明にかかる現像装置の一
実施例を備えた静電写真方式の複写機を示す概略図であ
る。図示の複写機は、静電潜像が形成される像担持体と
しての感光体ドラム１と、感光体ドラム１を一様に帯電
する帯電器２と、画像情報に応じて感光体ドラム１を露
光し静電潜像を形成する露光器３と、二成分現像剤を用
いて静電潜像を現像してトナー像を形成する現像装置４
と、現像されたトナー像を用紙５に転写するための転写
器６とを備えている。Embodiments of the present invention will now be described in detail with reference to the drawings. FIG. 1 is a schematic view showing an electrostatographic copying machine provided with an embodiment of a developing device according to the present invention. The copying machine shown in the drawing has a photosensitive drum 1 as an image carrier on which an electrostatic latent image is formed, a charger 2 for uniformly charging the photosensitive drum 1, and a photosensitive drum 1 according to image information. An exposing device 3 that exposes to form an electrostatic latent image, and a developing device 4 that develops the electrostatic latent image using a two-component developer to form a toner image.
And a transfer device 6 for transferring the developed toner image onto the sheet 5.
【００１４】以下、各部の構成、動作などについて、負
に帯電する感光体ドラム１を、負帯電トナーとキャリア
とから成る二成分現像剤を使用して反転現像を行うもの
として説明する。まず、帯電器２は感光体ドラム１の表
面を均一に負帯電し、露光器３は画像情報に応じて感光
体ドラム１に光を照射して画像部の電位を落とす。これ
により感光体ドラム１表面の背景部電位はＶＨ、画像部
電位はＶＬの電位となって、感光体ドラム１の表面に静
電潜像が形成される。次に、現像装置４の以下に述べる
現像スリーブ７にＶＬとＶＨの中間電位となるようにバ
イアス電圧ＶＢを与え、負帯電したトナーをこの現像ス
リーブ７上に付着させ、かつ現像スリーブ７を矢印方向
に回転させて付着したトナーを現像領域（感光体ドラム
１と現像スリーブ７とが対向している領域）に供給し、
該現像領域においてトナーを静電気力で静電潜像に向け
て移動させることにより、静電潜像を顕像化したトナー
像を形成する。トナー像は、送られてきた用紙５の紙面
上に転写器６により転写される。The structure and operation of each part will be described below assuming that the negatively charged photosensitive drum 1 is subjected to reversal development by using a two-component developer composed of negatively charged toner and carrier. First, the charger 2 uniformly negatively charges the surface of the photoconductor drum 1, and the exposure device 3 irradiates the photoconductor drum 1 with light according to image information to reduce the potential of the image portion. As a result, the background potential on the surface of the photosensitive drum 1 becomes VH and the image portion potential becomes VL, and an electrostatic latent image is formed on the surface of the photosensitive drum 1. Next, a bias voltage VB is applied to the developing sleeve 7 of the developing device 4 described below so as to have an intermediate potential between VL and VH, the negatively charged toner is adhered onto the developing sleeve 7, and the developing sleeve 7 is indicated by an arrow. To the developing area (the area where the photosensitive drum 1 and the developing sleeve 7 face each other) by rotating in the direction
In the developing area, the toner is moved toward the electrostatic latent image by the electrostatic force to form a toner image in which the electrostatic latent image is visualized. The toner image is transferred by the transfer device 6 onto the paper surface of the fed paper 5.
【００１５】図２は図１に示す現像装置４の主要部詳細
図である。現像装置４は、感光体ドラム１に対向して設
けられた、矢印方向に回転する現像スリーブ７と、その
内部に配置された固定のマグネットロール８とからなる
現像剤担持体（現像ローラ）９と、現像領域１０へ搬送
する現像剤量を規制する層厚規制部材１１と、トナーの
飛散を抑制するトナー飛散抑制電極１２とを有してい
る。マグネットロール８は、図２に示すように、現像領
域１０で現像剤を穂立ちさせる磁極Ｓ１、現像領域通過
後の現像剤を現像スリーブ７上から剥がすためのピック
オフ磁極Ｎ３、現像剤を現像スリーブ７に吸着させるた
めのピックアップ磁極Ｎ４、及び、層厚規制部材１１と
対向させ、現像剤の薄層を形成するためのトリミング磁
極Ｓ３、トナー飛散抑制電極１２を対向させる磁極Ｎ
１、更に、現像剤の搬送がスムーズにいくように反発磁
界を形成させないよう設けられた磁極Ｎ２，Ｓ２を有し
ている。FIG. 2 is a detailed view of the main parts of the developing device 4 shown in FIG. The developing device 4 includes a developer bearing member (developing roller) 9 including a developing sleeve 7 provided in opposition to the photosensitive drum 1 and rotating in the direction of the arrow, and a fixed magnet roll 8 disposed inside thereof. And a layer thickness regulating member 11 that regulates the amount of developer conveyed to the developing area 10, and a toner scattering suppressing electrode 12 that suppresses toner scattering. As shown in FIG. 2, the magnet roll 8 includes a magnetic pole S1 for making the developer stand in the developing area 10, a pick-off magnetic pole N3 for peeling the developer after passing through the developing area from the developing sleeve 7, and a developing sleeve for the developer. 7, a pickup magnetic pole N4 for adsorbing to 7, a trimming magnetic pole S3 for facing the layer thickness regulating member 11 and forming a thin layer of the developer, and a magnetic pole N for facing the toner scattering suppressing electrode 12.
1. Further, it has magnetic poles N2 and S2 provided so as not to form a repulsive magnetic field so that the developer can be conveyed smoothly.
【００１６】トナー飛散抑制電極１２は、例えば、アル
ミニウム製で、層厚規制部材１１と現像領域１０との間
の位置に、現像スリーブ７と０．２〜２．０ｍｍの間隔
をあけて設けられている。このトナー飛散抑制電極１２
は、現像剤担持体９の軸方向に沿って現像剤担持体９の
軸方向全域に対向させて設けられており、現像剤担持体
９との間に現像スリーブ７上のトナーに対して現像スリ
ーブ７側に向けて静電気力が作用するように電界を形成
すべく、電圧が印加される。The toner scattering suppressing electrode 12 is made of, for example, aluminum, and is provided at a position between the layer thickness regulating member 11 and the developing region 10 with a distance of 0.2 to 2.0 mm from the developing sleeve 7. ing. This toner scattering suppression electrode 12
Are provided so as to face the entire area of the developer carrying member 9 in the axial direction along the axial direction of the developer carrying member 9, and develop between the developer carrying member 9 and the toner on the developing sleeve 7. A voltage is applied to form an electric field so that the electrostatic force acts toward the sleeve 7 side.
【００１７】前記マグネットロール８の磁極上の現像剤
は、図３に示す様に穂立ちが形成され穂と穂との間が立
って疎な状態になっているため、トナー１３に対して現
像スリーブ７側に向けて力が働くように電界をかけた際
に、トナー１３をキャリア１４から剥がして現像スリー
ブ７側に押しつける効果が大きいので、マグネットロー
ル８の磁極Ｎ１に対向するようにトナー飛散抑制電極１
２を配置するのが好ましい。As shown in FIG. 3, the developer on the magnetic poles of the magnet roll 8 develops with respect to the toner 13 because the spikes are formed and the gaps between the spikes are sparse. When an electric field is applied so as to exert a force toward the sleeve 7 side, the toner 13 is peeled off from the carrier 14 and pressed against the developing sleeve 7 side, so that the toner is scattered so as to face the magnetic pole N1 of the magnet roll 8. Suppression electrode 1
It is preferable to arrange two.
【００１８】トナー飛散抑制電極１２には、非画像部に
対応する現像スリーブ７上の現像剤中のトナー１３に対
して現像スリーブ７側に向けて力が働くように、５．０
×１０5 Ｖ／ｍ以上の電界がかかるように電圧を印加す
る。すると、図４に示すように、トナー１３が現像剤の
上層部から下層部へ移り、現像スリーブ７の回転にとも
なう現像剤の動きによって発生するトナー飛散を抑制で
きる。画像部に対応する現像トナー７上の現像剤に対し
ては、トナー飛散抑制電極１２に現像スリーブ７と同電
圧を印加すると、現像に影響を与えないため好ましい。The toner-scattering suppressing electrode 12 has a force of 5.0 so that a force acts on the toner 13 in the developer on the developing sleeve 7 corresponding to the non-image portion toward the developing sleeve 7 side.
A voltage is applied so that an electric field of × 10 5 V / m or more is applied. Then, as shown in FIG. 4, the toner 13 moves from the upper layer portion of the developer to the lower layer portion, and it is possible to suppress the toner scattering generated by the movement of the developer accompanying the rotation of the developing sleeve 7. It is preferable to apply the same voltage as that of the developing sleeve 7 to the toner-scattering suppressing electrode 12 for the developer on the developing toner 7 corresponding to the image area, since it does not affect the development.
【００１９】なお、非画像部とは、感光体ドラム１上の
静電潜像が形成されていない領域を、画像部とは感光体
ドラム１上の静電潜像が形成されている領域を意味す
る。また、非画像部もしくは画像部に対応する現像スリ
ーブ７上の現像剤とは、現像スリーブ７上の領域のうち
その現像スリーブ７が回転して現像領域１０に位置した
ときに非画像部もしくは画像部に対向する領域上の現像
剤を意味する。The non-image area is the area on the photosensitive drum 1 on which the electrostatic latent image is not formed, and the image area is the area on the photosensitive drum 1 on which the electrostatic latent image is formed. means. Further, the developer on the developing sleeve 7 corresponding to the non-image area or the image area means the non-image area or the image when the developing sleeve 7 of the area on the developing sleeve 7 is rotated and positioned in the developing area 10. Means the developer on the area opposite the part.
【００２０】非画像部とは、例えば感光体ドラム１上の
周方向における前の静電潜像と次の静電潜像との間の領
域、あるいは感光体ドラム１の軸方向の一部の領域にの
み静電潜像が形成されている場合のその軸方向の残りの
静電潜像が形成されていない領域を意味する。次に、本
実施例の現像装置４を用いた作像工程の一例を説明す
る。帯電工程にて感光体ドラム１表面を一様に帯電し
（初期帯電電位ＶＨ）、露光工程にて画像情報に対応し
た潜像（原稿の画像部電位をＶＬ、非画像部電位ＶＨと
する）を形成後、現像工程にて反転現像（現像バイアス
電位ＶＢ）にて静電潜像を現像し、感光体ドラム１上に
トナー画像を形成する。The non-image portion is, for example, a region between the previous electrostatic latent image and the next electrostatic latent image on the photosensitive drum 1 in the circumferential direction, or a part of the photosensitive drum 1 in the axial direction. When the electrostatic latent image is formed only in the area, it means the area in which the remaining electrostatic latent image in the axial direction is not formed. Next, an example of an image forming process using the developing device 4 of this embodiment will be described. The surface of the photoconductor drum 1 is uniformly charged in the charging step (initial charging potential VH), and the latent image corresponding to the image information in the exposure step (the image portion potential of the original is VL, the non-image portion potential VH). After the formation, the electrostatic latent image is developed by reversal development (developing bias potential VB) in the developing process, and a toner image is formed on the photosensitive drum 1.
【００２１】上記の画像形成プロセスにおける各種条件
は次の通りである。 ・ＶＨ，ＶＬ，ＶＢ ＶＨ＝−６５０Ｖ ＶＬ＝−１００Ｖ ＶＢ＝−２５０Ｖ ・感光体ドラム 有機系感光体ドラム（負帯電型） ドラム外径８４ｍｍ ・プロセス速度 １６０ｍｍ／ｓ ・現像剤（トナー濃度８．０％） ・二成分系（負帯電の黒色トナー） ・磁性キャリア 平均粒径１００μｍのフェライト系キャリア ・黒色トナー スチレン−ｎ−ブチルメタクリレート共重合体９８部と
カーボンブラック７部とを混合し溶融混練後、平均粒径
１１μｍに微粉砕したもので、磁性キャリアに対し負極
性に帯電させる。 〔実施例１〕上記条件の下に上記の画像形成プロセスで
５０００枚の画像を形成し、その際トナー飛散抑制電極
１２に対し、現像領域１０において感光体ドラム１の周
方向における画像部間の非画像部に対向する現像スリー
ブ７の表面領域がトナー飛散抑制電極１２に対向する時
間帯に−１２５０Ｖ印加した。結果については後述す
る。 〔実施例２〕次に、実施例２について説明する。実施例
２では、図５に示す様に、最大使用用紙サイズをＡ３と
して、現像剤担持体９の軸方向（矢印方向）に延びるト
ナー飛散抑制電極１２の全体の長さをＡ３の幅方向と同
じとし、かつトナー飛散抑制電極１２を現像剤担持体９
の軸方向に沿ってＡ３，Ｂ３，Ｂ４，Ａ４の幅方向にあ
わせてＡ，Ｂ，Ｃ，Ｄ，Ｅの５つの小領域に分割し、各
小領域毎に電圧印加制御可能に構成した。Various conditions in the above image forming process are as follows. VH, VL, VB VH = -650V VL = -100V VB = -250V-Photosensitive drum Organic photosensitive drum (negative charging type) Drum outer diameter 84mm-Process speed 160mm / s-Developer (toner density 8. 0%) ・ Two-component system (negatively charged black toner) ・ Magnetic carrier Ferrite carrier with an average particle size of 100 μm ・ Black toner styrene-n-butyl methacrylate copolymer 98 parts and carbon black 7 parts are mixed and melt-kneaded. After that, the particles are finely pulverized to have an average particle size of 11 μm, and the magnetic carrier is negatively charged. [Embodiment 1] Under the above conditions, 5000 sheets of images are formed by the above-mentioned image forming process, and at this time, the toner scattering suppressing electrode 12 is provided between the image portions in the developing region 10 in the circumferential direction of the photosensitive drum 1. A voltage of -1250V was applied in the time zone in which the surface area of the developing sleeve 7 facing the non-image area faces the toner scattering suppression electrode 12. The results will be described later. [Second Embodiment] Next, a second embodiment will be described. In the second embodiment, as shown in FIG. 5, the maximum paper size used is A3, and the entire length of the toner scattering suppression electrode 12 extending in the axial direction (arrow direction) of the developer carrier 9 is the width direction of A3. In the same manner, the toner scattering suppression electrode 12 is connected to the developer carrier 9
It is divided into five small regions A, B, C, D and E along the axial direction of A3, B3, B4, A4 according to the width direction, and the voltage application can be controlled for each small region.
【００２２】分割にあたっては、画像部端部の現像剤に
影響をあたえないよう多少広めに分割するのが良い。本
実施例２では１５４，１８３，２１４，２５６ｍｍに分
割した。そして、使用する用紙のサイズに対応しない小
領域、例えば、Ａ４の用紙を使用する場合は小領域Ｄ，
Ｅに実施例１と同様な電圧を印加した。 〔実施例３〕実施例３として、上記実施例２のトナー飛
散抑制電極１２を用い、実施例１と同様にして５０００
枚の画像を形成した。トナー飛散抑制電極１２への電圧
印加は、実施例１の電圧印加と実施例２の電圧印加とを
組み合せた。 〔比較例〕比較例として、トナー飛散抑制電極１２を設
けない現像装置を用いて、実施例１と同様にして５００
０枚の画像を形成した。 〔クラウドの発生測定〕図１に示す様に、現像装置４に
キャッチパン（受け皿）１５を設け、実施例１，２，３
および比較例にて画像を１０００枚および５０００枚形
成した時点でそれぞれキャッチパン１５上に堆積したト
ナーの量を目視で観察し、これによりクラウドの発生量
（トナーの飛散量）を測定した。測定結果を下記表１に
示す。なお、表１においてＧ１はトナーの堆積が殆んど
ない状態を、Ｇ２はキャッチパン１５の表面にトナーが
５０％程度堆積した（キャッチパンの表面の５０％程度
がトナーに覆われて見えない）状態を、Ｇ３はキャッチ
パン１５の表面のほぼ全域がトナーに覆われて該表面が
殆んど見えない状態を、Ｇ４はキャッチパン１５の表面
にトナーが層状に堆積している状態を意味する。When dividing the image, it is preferable to divide the image slightly wider so as not to affect the developer at the edge of the image portion. In the second embodiment, it is divided into 154, 183, 214 and 256 mm. Then, a small area that does not correspond to the size of the used paper, for example, a small area D when using A4 size paper,
The same voltage as in Example 1 was applied to E. [Embodiment 3] As Embodiment 3, the toner scattering suppressing electrode 12 of Embodiment 2 is used, and 5000 is carried out in the same manner as in Embodiment 1.
A sheet of image was formed. The voltage application to the toner scattering suppression electrode 12 was a combination of the voltage application of Example 1 and the voltage application of Example 2. [Comparative Example] As a comparative example, a developing device not including the toner-scattering suppressing electrode 12 was used and the same procedure as in Example 1 was performed.
0 image was formed. [Measurement of Cloud Generation] As shown in FIG. 1, the developing device 4 is provided with a catch pan (saucepan) 15, and the first, second, and third embodiments are provided.
In the comparative example, the amount of toner deposited on the catch pan 15 was visually observed at the time when 1000 images and 5000 images were formed, and the amount of cloud generation (toner scattering amount) was measured. The measurement results are shown in Table 1 below. In Table 1, G1 indicates a state in which almost no toner is accumulated, and G2 indicates that about 50% of the toner is accumulated on the surface of the catch pan 15 (about 50% of the surface of the catch pan is covered with toner and cannot be seen). ), G3 means that almost the entire surface of the catch pan 15 is covered with toner and the surface is almost invisible, and G4 means that toner is accumulated in layers on the surface of the catch pan 15. To do.
【００２３】[0023]
【表１】 表１の測定結果から、トナー飛散抑制電極１２に電圧を
印加することにより、明らかにクラウドの発生が抑制さ
れていることが認められる。[Table 1] From the measurement results in Table 1, it is recognized that the generation of the cloud is obviously suppressed by applying the voltage to the toner scattering suppression electrode 12.
【００２４】上記各実施例１，２，３ではトナー飛散抑
制電極１２を別個に設けたが、トナー飛散抑制電極１２
は層厚規制部材１１によって構成することもできる。こ
の場合は、例えば、アクリル板の上にアルミのトナー飛
散抑制電極を配置し、これを層厚規制部材１１に設ける
ことができる。かかるトナー飛散抑制電極１２を実施例
２と同様に５つの小領域に分割し、使用する用紙のサイ
ズに対応しない小領域に実施例１と同様な電圧を印加し
た。この結果、実施例２と同等の効果が認められた。In each of the first, second, and third embodiments described above, the toner scattering suppression electrode 12 is provided separately, but the toner scattering suppression electrode 12
Can also be constituted by the layer thickness regulating member 11. In this case, for example, an aluminum toner scattering suppressing electrode may be arranged on the acrylic plate and provided on the layer thickness regulating member 11. The toner scattering suppression electrode 12 was divided into five small areas as in Example 2, and the same voltage as in Example 1 was applied to a small area that did not correspond to the size of the paper used. As a result, the same effect as in Example 2 was confirmed.
【００２５】上記各実施例では、いずれも非画像部に対
応させてトナー飛散抑制電極１２に所定の電圧を印加す
る様にしているか、電圧の印加は適宜に行えば良く、例
えば電圧印加による現像への悪影響を適宜の方法で回避
できれば、トナー飛散抑制電極１２の全域に常時電圧を
印加するようにしても良い。また、電圧の印加制御を行
うにあたっては、要は静電潜像に応じて電圧印加制御を
行えば良く、例えば画像部はトナーが付着するトナー部
とトナーが付着しない背景部とから成るが、非画像部の
みでなくこの背景部にも対応させて電圧を印加するよう
にしても良い。この場合は、勿論トナー飛散抑制電極１
２をその長手方向に沿って図５に示す実施例２よりもさ
らに多数の微小領域に分割して各微小領域毎に電圧印加
制御可能に構成することが望ましい。In each of the above-described embodiments, a predetermined voltage is applied to the toner-scattering suppressing electrode 12 in correspondence with the non-image area, or the voltage may be applied appropriately. For example, development by voltage application is performed. A voltage may be constantly applied to the entire area of the toner scattering suppression electrode 12 as long as the adverse effect on the toner scattering prevention electrode 12 can be avoided by an appropriate method. To control the voltage application, the voltage application control may be performed in accordance with the electrostatic latent image. For example, the image part is composed of a toner part to which toner adheres and a background part to which toner does not adhere. The voltage may be applied not only to the non-image area but also to the background area. In this case, of course, the toner scattering suppression electrode 1
It is desirable to divide 2 into a larger number of minute regions than the second embodiment shown in FIG. 5 along its longitudinal direction so that voltage application can be controlled for each minute region.
【００２６】また、上記各実施例ではトナー飛散抑制電
極１２を現像領域１０よりも上流側であって、かつ層厚
規制部材１１よりも下流側に設けているが、トナー飛散
抑制電極１２は現像領域１０の下流側に設けても良い。
この場合は、例えばトナー飛散抑制電極１２に常時電圧
を印加することができ、現像終了後の現像剤のトナーの
飛散を抑制することができる。In each of the above embodiments, the toner-scattering suppressing electrode 12 is provided upstream of the developing region 10 and downstream of the layer thickness regulating member 11, but the toner-scattering suppressing electrode 12 is developed. It may be provided on the downstream side of the region 10.
In this case, for example, a voltage can be constantly applied to the toner-scattering suppression electrode 12, and the scattering of the toner of the developer after the development can be suppressed.
【図１】本発明に係る現像装置の一実施例を備えた複写
機の概略構成を示す説明図である。FIG. 1 is an explanatory diagram showing a schematic configuration of a copying machine including an embodiment of a developing device according to the present invention.
【図２】図１に示す現像装置の要部を詳細に示す説明図
である。FIG. 2 is an explanatory diagram showing in detail a main part of the developing device shown in FIG.
【図３】トナー飛散抑制電極に電圧を印加しない場合の
現像スリーブ上の現像剤の状態を示す説明図である。FIG. 3 is an explanatory diagram showing a state of a developer on a developing sleeve when a voltage is not applied to a toner scattering suppressing electrode.
【図４】トナー飛散抑制電極に電圧を印加した場合の現
像スリーブ上の現像剤の状態を示す説明図である。FIG. 4 is an explanatory diagram showing a state of a developer on a developing sleeve when a voltage is applied to a toner scattering suppression electrode.
【図５】本発明に係るトナー飛散抑制電極の他の実施例
の概略構成を示す説明図である。FIG. 5 is an explanatory diagram showing a schematic configuration of another embodiment of the toner scattering suppressing electrode according to the present invention.
１ 感光体ドラム ４ 現像装置 ７ 現像スリーブ ８ 固定マグネットロール ９ 現像剤担持体 １０ 現像領域 １１ 層厚規制部材 １２ トナー飛散抑制電極 DESCRIPTION OF SYMBOLS 1 Photoconductor drum 4 Developing device 7 Developing sleeve 8 Fixed magnet roll 9 Developer carrier 10 Developing area 11 Layer thickness regulating member 12 Toner scattering suppressing electrode
───────────────────────────────────────────────────── フロントページの続き (72)発明者 青島 琢 神奈川県海老名市本郷2274番地 富士ゼロ ックス株式会社海老名事業所内 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Taku Aoshima 2274 Hongo, Ebina City, Kanagawa Prefecture Fuji Xerox Co., Ltd.
Claims (4)
の内部に配設された固定マグネットとからなり、静電潜
像が形成される像担持体に対向して配設され、磁性キャ
リアとトナーとからなる二成分現像剤を前記現像スリー
ブ上に吸着して現像領域へ搬送する現像剤担持体を備え
て成る現像装置において、 前記現像スリーブに所定の間隔をおいて対向させて、該
現像スリーブ上のトナーに対して該現像スリーブ側に向
けて静電気力が作用するように電圧が印加されるトナー
飛散抑制電極が配設されていることを特徴とする現像装
置。1. A rotating developing sleeve and a fixed magnet disposed inside the developing sleeve, and the magnetic carrier and toner are disposed so as to face an image carrier on which an electrostatic latent image is formed. A developing device comprising a developer carrying member for adsorbing a two-component developer consisting of the above onto the developing sleeve and transporting the two-component developer to the developing region, wherein the developing sleeve is opposed to the developing sleeve at a predetermined interval. And a toner scattering suppressing electrode to which a voltage is applied so that an electrostatic force acts on the toner toward the developing sleeve.
担持体の軸方向に沿って延びると共に該軸方向に沿って
複数の小領域に分割され、各小領域毎に前記電圧を印加
制御可能に構成されていることを特徴とする請求項１記
載の現像装置。2. The toner scattering suppressing electrode extends along the axial direction of the developer carrying member and is divided into a plurality of small regions along the axial direction, and the voltage can be controlled to be applied to each small region. The developing device according to claim 1, wherein the developing device is configured as follows.
グネットの磁極に対向する位置に配設されていることを
特徴とする請求項１又は２記載の現像装置。3. The developing device according to claim 1, wherein the toner scattering suppression electrode is arranged at a position facing a magnetic pole of the fixed magnet.
像領域へ搬送される前記現像剤の層厚を規制する層厚規
制部材を備え、前記トナー飛散抑制電極が、前記層厚規
制部材によって構成されていることを特徴とする請求項
１から３のうちちずれか１項記載の現像装置。4. A layer thickness regulating member for regulating the layer thickness of the developer adsorbed on the developing sleeve and conveyed to the developing area, wherein the toner scattering suppression electrode is constituted by the layer thickness regulating member. 4. The developing device according to claim 1, wherein the developing device is provided with one of the following.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP4306895A JPH08240972A (en) | 1995-03-02 | 1995-03-02 | Developing device |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP4306895A JPH08240972A (en) | 1995-03-02 | 1995-03-02 | Developing device |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH08240972A true JPH08240972A (en) | 1996-09-17 |
Family
ID=12653546
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP4306895A Withdrawn JPH08240972A (en) | 1995-03-02 | 1995-03-02 | Developing device |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH08240972A (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US7957681B2 (en) | 2009-03-27 | 2011-06-07 | Canon Kabushiki Kaisha | Developing device |
| US11914312B2 (en) | 2021-07-14 | 2024-02-27 | Kyocera Document Solutions Inc. | Developing device and image forming apparatus including the same |
-
1995
- 1995-03-02 JP JP4306895A patent/JPH08240972A/en not_active Withdrawn
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US7957681B2 (en) | 2009-03-27 | 2011-06-07 | Canon Kabushiki Kaisha | Developing device |
| US11914312B2 (en) | 2021-07-14 | 2024-02-27 | Kyocera Document Solutions Inc. | Developing device and image forming apparatus including the same |
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