JP2903770B2 - Development method - Google Patents
Development methodInfo
- Publication number
- JP2903770B2 JP2903770B2 JP12447091A JP12447091A JP2903770B2 JP 2903770 B2 JP2903770 B2 JP 2903770B2 JP 12447091 A JP12447091 A JP 12447091A JP 12447091 A JP12447091 A JP 12447091A JP 2903770 B2 JP2903770 B2 JP 2903770B2
- Authority
- JP
- Japan
- Prior art keywords
- electrostatic latent
- latent image
- developer
- carrier
- holding member
- 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
Links
Landscapes
- Magnetic Brush Developing In Electrophotography (AREA)
Description
【０００１】[0001]
【産業上の利用分野】本発明は、電子写真複写機等の画
像形成装置において用いられ、感光体上の静電潜像を粉
状現像剤によって現像する方法に係り、特に絶縁性トナ
ーと磁性粒子とを混合した二成分現像剤を用いる現像方
法に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for developing an electrostatic latent image on a photoreceptor with a powdery developer, which is used in an image forming apparatus such as an electrophotographic copying machine. The present invention relates to a developing method using a two-component developer mixed with particles.
【０００２】[0002]
【従来の技術】従来より二成分現像剤を用いた現像方法
として現像剤担持体を使用し、これと近接する感光体上
の静電潜像にトナーを転写する方法が知られている。こ
の方法に使用される現像装置の概略は例えば次のような
ものである。静電潜像保持体と近接して配置され表面に
現像剤を吸着して搬送することができる現像剤担持体
と、この現像剤担持体上に吸着された現像剤の量を規制
し、現像剤の薄層を形成する現像剤規制部材とがハウジ
ング内に設けられており、ハウジング内の現像剤収容室
から現像剤担持体に現像剤が供給されるようになってい
る。2. Description of the Related Art Conventionally, as a developing method using a two-component developer, there has been known a method in which a developer carrying member is used and toner is transferred to an electrostatic latent image on a photosensitive member adjacent to the developer carrying member. The outline of the developing device used in this method is as follows, for example. A developer carrier that is arranged in close proximity to the electrostatic latent image carrier and that can adsorb and transport the developer to the surface, and regulates the amount of the developer adsorbed on the developer carrier, A developer regulating member that forms a thin layer of developer is provided in the housing, and the developer is supplied to the developer carrier from a developer storage chamber in the housing.
【０００３】上記現像剤担持体は非磁性材料からなり回
転可能に支持された円筒状のスリーブと、その内部にお
いて位置が不動に取り付けられた複数の磁石とを有して
おり、その磁石の磁界によって現像剤がスリーブの表面
に吸着され、現像剤中の磁性粒子（キャリア）による磁
気ブラシが形成されるようになっている。また、現像剤
担持体には静電潜像保持体との間に電界を生じさせるバ
イアス電圧が印加されている。この現像剤担持体は静電
潜像保持体と近接して対向する位置に設けられ、この対
向する位置が現像領域となり、ここでの双方の間隔は上
記磁気ブラシが静電潜像保持体と接触し得る程度に設定
されている。The developer carrier has a cylindrical sleeve made of a non-magnetic material and rotatably supported, and a plurality of magnets fixedly mounted inside the sleeve. As a result, the developer is adsorbed on the surface of the sleeve, and a magnetic brush is formed by magnetic particles (carrier) in the developer. A bias voltage for generating an electric field between the developer carrier and the electrostatic latent image carrier is applied to the developer carrier. The developer carrier is provided at a position close to and opposed to the electrostatic latent image holder, and the opposed position is a development area, and the distance between the two is set by the magnetic brush and the electrostatic latent image holder. It is set so that it can touch.
【０００４】このような現像装置において静電潜像の現
像は次のような方法によって行われる。図６に示すよう
に磁気ブラシが静電潜像保持体と接触した状態で静電潜
像保持体が回転を開始し、その表面が一様に帯電された
後、露光によって帯電電位の差による静電潜像が形成さ
れる。その後、バイアス電圧の印加が開始されるととも
に現像剤担持体が回転動作を開始し、現像剤担持体表面
に形成されている磁気ブラシが連続的に現像領域へ搬送
される。現像領域ではバイアス電圧が印加されており、
帯電したトナーは静電潜像保持体の表面に接触する磁気
ブラシから静電潜像に付着し、現像が行なわれる。静電
潜像保持体上の静電潜像が現像領域を通過した後は、現
像剤担持体の回転が停止されるとともにバイアス電圧の
印加が解除され、一連の現像工程を終了する。The development of an electrostatic latent image in such a developing device is performed by the following method. As shown in FIG. 6, the electrostatic latent image holding member starts rotating in a state where the magnetic brush is in contact with the electrostatic latent image holding member, and after the surface thereof is uniformly charged, the surface is uniformly charged. An electrostatic latent image is formed. Thereafter, the application of the bias voltage is started and the developer carrier starts rotating, and the magnetic brush formed on the surface of the developer carrier is continuously transported to the developing area. In the development area, a bias voltage is applied,
The charged toner adheres to the electrostatic latent image from a magnetic brush in contact with the surface of the electrostatic latent image holding member, and is developed. After the electrostatic latent image on the electrostatic latent image holder passes through the developing area, the rotation of the developer carrier is stopped, the application of the bias voltage is released, and a series of developing steps is completed.
【０００５】[0005]
【発明が解決しようとする課題】しかしながら、上記の
ような従来の現像方法では、現像剤担持体の始動および
停止、バイアス電圧の印加および解除と関連して表１に
示すような問題点がある。However, in the conventional developing method as described above, there are problems as shown in Table 1 in relation to starting and stopping of the developer carrier and application and release of the bias voltage. .
【０００６】[0006]
【表１】 [Table 1]
【０００７】現像を開始しようとするとき、磁気ブラシ
が静電潜像保持体と接触しており、静電潜像保持体が動
作している状態で現像剤担持体の動作を開始する（表１
中、欄）と、接触している磁気ブラシが急に動きだす
ことになり、多量の現像剤が静電潜像保持体に付着す
る。多量に付着した現像剤は現像領域において、現像剤
担持体と静電潜像保持体との間隙に詰まり、静電潜像保
持体の回転速度にムラを生じることになる。静電潜像保
持体の回転速度のムラは像の歪みを生じさせ、特に複数
の色を重ね合わせるカラー画像を形成しようとする場合
には、静電潜像保持体の回転速度の変動がわずかであっ
ても色ずれが生じ、良好な画像が得られない。When the development is to be started, the magnetic brush is in contact with the electrostatic latent image carrier, and the operation of the developer carrier is started in a state where the electrostatic latent image carrier is operating (see Table 1). 1
, Column), the magnetic brush in contact with it suddenly starts to move, and a large amount of developer adheres to the electrostatic latent image holding member. A large amount of the developer adheres to the gap between the developer carrier and the electrostatic latent image holder in the development area, causing uneven rotation speed of the electrostatic latent image holder. Unevenness in the rotation speed of the electrostatic latent image holder causes image distortion, and particularly when an attempt is made to form a color image in which a plurality of colors are superimposed, fluctuations in the rotation speed of the electrostatic latent image holder are slight. However, a color shift occurs, and a good image cannot be obtained.
【０００８】また、静電潜像保持体表面に付着する現像
剤にはトナーのみではなく磁性粒子であるキャリアも含
まれており、キャリアが多量に付着するとブレードによ
るクリーニング装置を用いた場合には、ブレードや静電
潜像保持体表面が傷つき、黒すじや黒斑などの画像欠陥
が生じる。また用紙への転写装置として静電潜像保持体
と近接して回転する転写ロールを用いる場合には、静電
潜像保持体に付着したキャリアが転写ロールと静電潜像
保持体との近接部分を通過する際に、静電潜像保持体の
回転に対する負荷を増大させ、静電潜像保持体の回転速
度が変動して画像に欠陥が生じることになる。このよう
な問題点はバイアス電圧が印加されている状態、または
印加されていない状態のいずれの場合にも生じる。Further, the developer adhering to the surface of the electrostatic latent image holding member includes not only toner but also carrier which is a magnetic particle. In this case, the blade and the surface of the electrostatic latent image holding member are damaged, and image defects such as black streaks and black spots occur. When a transfer roll that rotates in close proximity to the electrostatic latent image holding member is used as a transfer device for paper, the carrier adhered to the electrostatic latent image holding member is moved close to the transfer roll and the electrostatic latent image holding member. When passing through the portion, the load on the rotation of the electrostatic latent image holding member is increased, and the rotation speed of the electrostatic latent image holding member fluctuates, resulting in image defects. Such a problem occurs regardless of whether the bias voltage is applied or not applied.
【０００９】また、現像剤担持体の動作を停止したとき
（表１中、欄）にも、急に磁気ブラシの動きが止まる
ことによって現像剤が静電潜像保持体に多量に付着する
という問題が生じる。Also, when the operation of the developer carrying member is stopped (column in Table 1), the movement of the magnetic brush suddenly stops, so that a large amount of the developer adheres to the electrostatic latent image holding member. Problems arise.
【００１０】一方、静電潜像保持体が動作し、磁気ブラ
シが接触した状態でバイアス電圧の印加を開始したとき
（表１中、欄）および印加を解除したとき（表１中、
欄）にも急に電界の作用が開始または停止されること
によって多量の現像剤が静電潜像保持体に付着する。こ
れによって上記現像剤担持体の始動時および停止時と同
様の問題が生じる。さらにバイアス電圧の印加時には、
電圧が図７に示すように変動し、一時的に印加電圧が高
くなる（オーバーシュート）。これによって現像剤担持
体と静電潜像保持体との間でバイアス電圧下の放電がお
こり、静電潜像保持体表面を傷つけることがある。On the other hand, when the electrostatic latent image holding member operates and the application of the bias voltage is started in the state where the magnetic brush is in contact (column in Table 1), and when the application of the bias voltage is canceled (in Table 1,
In column (a), a large amount of developer adheres to the electrostatic latent image holding member when the action of the electric field is suddenly started or stopped. As a result, the same problem occurs when the developer carrier is started and stopped. When applying a bias voltage,
The voltage fluctuates as shown in FIG. 7, and the applied voltage temporarily increases (overshoot). As a result, a discharge under a bias voltage occurs between the developer carrying member and the electrostatic latent image holding member, which may damage the surface of the electrostatic latent image holding member.
【００１１】表１中、欄に示すように現像剤担持体の
始動とバイアス電圧の印加開始時に差があり、バイアス
電圧が先に印加される場合には、現像領域内で静止して
いる磁気ブラシのキャリアに電荷の注入がおこり、帯電
したキャリアが静電潜像保持体に付着するという問題が
ある。キャリアが静電潜像保持体に付着すると上記した
ように画像の欠陥を生じる原因となる。In Table 1, as shown in the column, there is a difference between the start of the developer carrier and the start of the application of the bias voltage, and when the bias voltage is applied first, the magnetic field that is stationary in the development area is changed. There is a problem that charge is injected into the brush carrier and the charged carrier adheres to the electrostatic latent image holding member. When the carrier adheres to the electrostatic latent image holding member, it causes image defects as described above.
【００１２】静電潜像保持体を停止した状態であって
も、バイアス電圧の印加開始時（表１中、欄）におい
ては静電潜像保持体と現像剤担持体との間でのバイアス
下の放電によって静電潜像保持体を傷つけるという問題
があり、さらに現像剤担持体が停止しておりバイアス電
圧のみが作用する状態（表１中、欄）ではキャリアへ
の電荷の注入がおこる。さらに静電潜像保持体が停止し
ている状態で現像剤担持体を動作させる（表１中、
欄）と、磁気ブラシが静電潜像保持体の一カ所のみと接
触し、静電潜像保持体表面を傷つけるという問題もあ
る。Even when the electrostatic latent image holding member is stopped, the bias between the electrostatic latent image holding member and the developer holding member is started when the bias voltage is applied (column in Table 1). There is a problem that the electrostatic discharger may damage the electrostatic latent image holder due to the lower discharge, and further, when the developer carrier is stopped and only the bias voltage is applied (column in Table 1), charge injection into the carrier occurs. . Further, the developer carrier is operated in a state where the electrostatic latent image carrier is stopped (in Table 1,
Column), and there is also a problem that the magnetic brush contacts only one portion of the electrostatic latent image holding member and damages the surface of the electrostatic latent image holding member.
【００１３】カラー画像を形成する画像形成装置では、
複数の現像装置が一つの静電潜像保持体に対向して設け
られ、これらの現像装置が現像を行なわないときには静
電潜像保持体と磁気ブラシとが接触しない位置に保持さ
れ、現像を行なう現像装置のみが移動して磁気ブラシと
静電潜像保持体とが接触する位置に設定されるものがあ
る。このような現像装置を有する画像形成装置において
も、現像に使用される現像装置が磁気ブラシと静電潜像
保持体とが接触する位置に設定され、その後現像剤担持
体の回転およびバイアス電圧の印加を開始して現像を行
ない、現像終了後は現像剤担持体の回転、バイアス電圧
の印加を停止した後に現像装置を静電潜像保持体から離
隔するようになっているので、上記と全く同様の問題点
を有している。In an image forming apparatus for forming a color image,
A plurality of developing devices are provided so as to face one electrostatic latent image holding member, and when these developing devices do not perform development, they are held at positions where the electrostatic latent image holding member does not come into contact with the magnetic brush. In some cases, only the developing device to be moved is set at a position where the magnetic brush and the electrostatic latent image holder come into contact with each other. Also in the image forming apparatus having such a developing device, the developing device used for development is set at a position where the magnetic brush and the electrostatic latent image holding member are in contact with each other, and then the rotation of the developer carrying member and the bias voltage are set. The application is started and development is performed. After the development is completed, the rotation of the developer carrier and the application of the bias voltage are stopped, and then the developing device is separated from the electrostatic latent image holding member. It has similar problems.
【００１４】本発明は上記のような状況に鑑みてなされ
たものであり、その目的は、静電潜像の現像を開始する
までの状態または静電潜像の現像終了後、現像状態を解
除する状態において、静電潜像保持体に現像剤が多量に
付着することや、バイアス電圧下の放電が生じることを
防止し、良好な画像が得られる現像方法を提供すること
である。SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and has as its object to release the development state until the development of the electrostatic latent image is started or after the development of the electrostatic latent image is completed. It is an object of the present invention to provide a developing method capable of preventing a large amount of developer from adhering to an electrostatic latent image holding member and preventing a discharge under a bias voltage from being generated, and obtaining a good image.
【００１５】[0015]
【課題を解決するための手段】上記問題点を解決するた
めに、本発明は、磁石ロールを内蔵し、表面に二成分現
像剤の磁気ブラシを形成して現像剤を搬送する現像剤担
持体と、露光によって表面に静電潜像が形成される静電
潜像保持体とが近接して対向する位置で、前記磁気ブラ
シを前記静電潜像保持体表面に接触させるとともに、前
記静電潜像保持体と現像剤担持体との間にバイアス電圧
を印加し、帯電した現像剤を前記静電潜像に付着させて
可視化する現像方法において、 図１に示すように、前
記静電潜像を現像しないときは、前記現像剤担持体を、
前記磁気ブラシが静電潜像保持体に接触しない位置に保
持し、 前記静電潜像保持体上の静電潜像を現像すると
きに、バイアス電圧の印加、および現像剤担持体の動作
を開始し、 その後現像剤担持体を、前記磁気ブラシが
動作中の前記静電潜像保持体と接触する位置に移動させ
て現像を行ない、 現像終了後、再び前記現像剤担持体
を、前記磁気ブラシが動作中の前記静電潜像保持体と接
触しない位置に戻し、 その後バイアス電圧の印加解
除、および現像剤担持体の動作の停止を行なうものとす
る。SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention relates to a developer carrying member having a built-in magnet roll, forming a magnetic brush of a two-component developer on the surface, and transporting the developer. And contacting the magnetic brush with the surface of the electrostatic latent image holding member at a position where the electrostatic latent image holding member having an electrostatic latent image formed on the surface by exposure is in close proximity to the electrostatic latent image holding member. In a developing method in which a bias voltage is applied between a latent image holding member and a developer carrying member to make a charged developer adhere to the electrostatic latent image to visualize the electrostatic latent image, as shown in FIG. When the image is not developed, the developer carrier is
When the magnetic brush is held at a position where it does not contact the electrostatic latent image holding member, and when the electrostatic latent image on the electrostatic latent image holding member is developed, application of a bias voltage and operation of the developer holding member are performed. Start, and thereafter, the developer carrying member is moved to a position where the magnetic brush is in contact with the electrostatic latent image holding member during operation to perform the development. After the development is completed, the developer carrying member is again moved to the magnetic state. The brush is returned to a position where it does not come into contact with the electrostatic latent image holding member during operation, and then the application of the bias voltage is stopped and the operation of the developer holding member is stopped.
【００１６】上記バイアス電圧印加の開始時（ＴB1）
と、現像剤担持体の動作の開始時（ＴR1）はいずれが先
であっても良いし、同時であってもよい。また、上記バ
イアス電圧印加の解除時（ＴB2）と、現像剤担持体の動
作の停止時（ＴR2）はいずれが先であってもよいし、同
時であってもよい。また、静電潜像保持体の動作の開始
時（ＴS1）は磁気ブラシが静電潜像保持体と接触する時
（ＴT1）より先であればよく、静電潜像保持体の動作の
停止時（ＴS2）は、現像終了後に磁気ブラシが静電潜像
保持体と離れる時（ＴT2）の後とすればよい。At the start of the bias voltage application (T B1 )
And the start of the operation of the developer carrier (T R1 ) may be either earlier or simultaneously. Either the release of the bias voltage application (T B2 ) or the stop of the operation of the developer carrier (T R2 ) may be performed first or simultaneously. The start of the operation of the electrostatic latent image holder (T S1 ) may be earlier than the time when the magnetic brush contacts the electrostatic latent image holder (T T1 ). (T S2 ) may be after the time (T T2 ) when the magnetic brush separates from the electrostatic latent image holding member after the development is completed.
【００１７】[0017]
【作用】上記のような現像方法では、現像を行わないと
きに現像剤担持体はその表面に形成された磁気ブラシが
静電潜像保持体と接触しない位置に保持されており、現
像を開始する時にそのままの位置でバイアス電圧の印
加、および現像剤担持体の始動が行われる。したがっ
て、静電潜像保持体に多量の現像剤が付着するようなこ
とはなく、またバイアス電圧下の放電も生じない。バイ
アス電圧の印加開始、および現像剤担持体の始動後、磁
気ブラシが静電潜像保持体表面と接触する位置に現像剤
担持体を移動するので、磁気ブラシは現像剤担持体上で
搬送されながら徐々に静電潜像保持体の表面と接触し、
このときにも現像剤の多量の付着等は生じない。In the above-described developing method, when the developing is not performed, the developer-carrying member is held at a position where the magnetic brush formed on the surface does not contact the electrostatic latent image holding member, and the developing is started. Then, the bias voltage is applied and the developer carrier is started at the same position. Accordingly, a large amount of the developer does not adhere to the electrostatic latent image holding member, and no discharge occurs under the bias voltage. After the application of the bias voltage and the start of the developer carrier, the magnetic brush moves to a position where it contacts the surface of the electrostatic latent image carrier, so that the magnetic brush is conveyed on the developer carrier. While gradually contacting the surface of the electrostatic latent image carrier,
At this time, a large amount of the developer does not adhere.
【００１８】静電潜像が現像領域を通過し、現像が終了
すると磁気ブラシが静電潜像保持体と接触しない位置ま
で現像剤担持体を移動させ、その後バイアス電圧の印加
解除、および現像剤担持体の動作の停止を行なうので、
バイアス電圧の印加開始時、および現像剤担持体の始動
時と同様、静電潜像保持体に多量の現像剤が付着するよ
うな不都合がなくなる。これによって画像に欠陥が生じ
るのが防止される。When the electrostatic latent image passes through the developing area and the development is completed, the developer carrier is moved to a position where the magnetic brush does not come into contact with the electrostatic latent image carrier. Since the operation of the carrier is stopped,
As with the start of the application of the bias voltage and the start of the developer carrier, the disadvantage that a large amount of the developer adheres to the electrostatic latent image holder is eliminated. This prevents image defects.
【００１９】[0019]
【実施例】以下本発明の実施例について図を用いて説明
する。図２は本発明の実施例である現像方法に用いられ
る現像装置の一例を示す概略構成図である。現像装置２
は、帯電電位の差による静電潜像を保持することができ
る静電潜像保持体１と対向して設けられており、この現
像装置２は現像剤を収容するハウジング７と、位置が固
定された複数の磁石９を内部に有しこの周囲で回転自在
に支持された非磁性円筒状の現像剤担持体３と、現像剤
担持体３の表面に付着する磁性現像剤の量を規制する現
像剤規制部材４と、回転して現像剤の攪拌及び搬送を行
ない現像剤担持体３に現像剤を供給するスクリューオー
ガー５、６とを備えている。DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below with reference to the drawings. FIG. 2 is a schematic configuration diagram illustrating an example of a developing device used in the developing method according to the embodiment of the present invention. Developing device 2
Is provided opposite to an electrostatic latent image holding member 1 capable of holding an electrostatic latent image due to a difference in charging potential. The developing device 2 has a housing 7 for housing a developer and a fixed position. A non-magnetic cylindrical developer carrier 3 having a plurality of magnets 9 therein and rotatably supported around the magnet 9, and regulates the amount of magnetic developer adhering to the surface of the developer carrier 3. The image forming apparatus includes a developer regulating member 4 and screw augers 5 and 6 that rotate and stir and transport the developer to supply the developer to the developer carrier 3.
【００２０】上記静電潜像保持体１は表面に高分子化合
物からなる感光体（ｏｐｃ感光体）を有しており、一旦
一様に帯電させた後露光して静電潜像を形成できるもの
である。上記現像剤担持体３は内部に複数の磁石９を有
し、これらはＳ極とＮ極とが交互に配置されたもので、
隣接する磁極間で形成される磁界によって磁性粒子の磁
気ブラシを現像剤担持体３の表面に形成し、回転して現
像剤を搬送できるようになっている。また、現像剤担持
体３には直流電源１０および交流電源１１から直流重量
交流電圧が印加されており、静電潜像保持体１と近接す
る位置（現像領域）に形成される電界によって電荷を有
するトナーが静電潜像に付着するようになっている。現
像剤規制部材４は、一端がハウジング７と固定して支持
され、他端が現像剤担持体３の表面に近接して突き出す
ように取り付けられており、現像剤担持体表面に吸着さ
れる現像剤を一定量に規制するものである。The electrostatic latent image holding member 1 has a photoreceptor (opc photoreceptor) made of a polymer compound on its surface, and can be charged once and then exposed to form an electrostatic latent image. Things. The developer carrier 3 has a plurality of magnets 9 therein, which are arranged with S poles and N poles alternately.
A magnetic brush of magnetic particles is formed on the surface of the developer carrier 3 by a magnetic field formed between adjacent magnetic poles, and the developer can be rotated to transport the developer. Further, a DC weight AC voltage is applied to the developer carrier 3 from a DC power supply 10 and an AC power supply 11, and electric charges are generated by an electric field formed at a position (developing area) close to the electrostatic latent image holding body 1. The toner contained therein adheres to the electrostatic latent image. One end of the developer regulating member 4 is fixedly supported on the housing 7 and the other end is attached so as to protrude in the vicinity of the surface of the developer carrier 3, and the developer is adsorbed on the surface of the developer carrier. The agent is regulated to a fixed amount.
【００２１】このような現像装置２は、現像剤担持体３
が静電潜像保持体１と近接して対向し得る位置に設けら
れており、静電潜像保持体１と現像剤担持体３との間隔
が０．５ｍｍ程度（現像剤担持体３上の磁気ブラシが静
電潜像保持体１と接触し得る間隔）となる位置およびこ
れらの間隔が現像剤担持体表面に形成される磁気ブラシ
と静電潜像保持体表面とが接触しない程度となる位置に
設定することができ、カム８の回転によって上記双方の
位置の間を移動できるようになっている。The developing device 2 includes a developer carrier 3
Is provided at a position close to and opposing the electrostatic latent image holder 1, and the distance between the electrostatic latent image holder 1 and the developer carrier 3 is about 0.5 mm (on the developer carrier 3). The distance between the magnetic brush formed on the surface of the developer carrying member and the surface of the electrostatic latent image holding member is determined by the distance between the magnetic brush and the surface of the electrostatic latent image holding member. The cam 8 can be moved between the two positions by rotating the cam 8.
【００２２】このような現像装置は、静電潜像保持体に
対して一つの現像装置のみが対向する画像形成装置に用
いてもよいが、図３に示すように複数の現像装置が一つ
の静電潜像保持体に対向して配置され、それぞれの現像
装置は色が異なる画像の現像を行うカラー画像形成装置
に用いることができる。図３に示す画像形成装置では三
つの現像装置２ａ，２ｂ，２ｃが配列されており、それ
ぞれがカム８ａ，８ｂ，８ｃの回転によって、現像剤担
持体３ａ，３ｂ，３ｃの表面に形成される磁気ブラシが
静電潜像保持体１と接触する位置と接触しない位置との
双方に設定できるようになっている。Such a developing device may be used in an image forming apparatus in which only one developing device faces the electrostatic latent image holding member, but as shown in FIG. Each of the developing devices arranged opposite to the electrostatic latent image holding member can be used in a color image forming apparatus for developing an image having a different color. In the image forming apparatus shown in FIG. 3, three developing devices 2a, 2b, 2c are arranged, each of which is formed on the surface of the developer carrier 3a, 3b, 3c by rotation of the cams 8a, 8b, 8c. The position can be set at both a position where the magnetic brush contacts the electrostatic latent image holding member 1 and a position where the magnetic brush does not contact the electrostatic latent image holder 1.
【００２３】本発明の一実施例である現像方法は、例え
ばこのような画像形成装置において実施することができ
るものであり、以下にこの実施例を説明する。現像を開
始する前の段階ではすべての現像装置は、現像剤担持体
表面の磁気ブラシと静電潜像保持体１とが接触しない位
置に設定されている。現像プロセスの開始にともない静
電潜像保持体１は回転して、表面が一様に帯電される。
その後、像光が照射され、照射される光の強さにしたが
って静電潜像保持体１の表面には帯電電位の差による静
電潜像が形成される。この静電潜像は単色の画像に対応
するものであり、この静電潜像に対応する色の現像装
置、すなわち図３に示す第１の現像装置２ａの動作が開
始される。The developing method according to an embodiment of the present invention can be carried out, for example, in such an image forming apparatus. This embodiment will be described below. At the stage before the development is started, all the developing devices are set at positions where the magnetic brush on the surface of the developer carrier and the electrostatic latent image holder 1 are not in contact with each other. At the start of the developing process, the electrostatic latent image holder 1 rotates and the surface is uniformly charged.
Thereafter, image light is irradiated, and an electrostatic latent image is formed on the surface of the electrostatic latent image holding member 1 due to a difference in charged potential according to the intensity of the irradiated light. The electrostatic latent image corresponds to a single-color image, and the operation of the developing device for the color corresponding to the electrostatic latent image, that is, the first developing device 2a shown in FIG. 3 is started.
【００２４】現像装置の動作は、図４に示すようにまず
現像剤担持体３ａの回転の始動とバイアス電圧の印加が
同時に行われる。回転するスクリューオーガー５ａ、６
ａから現像剤担持体３ａに供給された現像剤が表面にお
いて磁気ブラシを形成しており、この現像剤の層は現像
剤規制部材４ａによって規制された後、現像剤担持体３
ａの回転によって連続的に現像領域へと搬送される。現
像剤担持体３ａの回転が始動し、バイアス電圧が印加さ
れた後、カム８ａが回転し、第１の現像装置２ａが現像
剤担持体３ａ上の磁気ブラシと静電潜像保持体１とが接
触する位置へ移動する。このとき現像剤担持体３ａと静
電潜像保持体１との間にはバイアス電界が生じており、
帯電したトナーが静電潜像保持体１上の静電潜像に付着
し、静電潜像を可視化する。In the operation of the developing device, as shown in FIG. 4, the start of rotation of the developer carrier 3a and the application of a bias voltage are simultaneously performed. Rotating screw augers 5a, 6
The developer supplied from a to the developer carrier 3a forms a magnetic brush on the surface, and the layer of the developer is regulated by the developer regulating member 4a.
By the rotation of a, the sheet is continuously conveyed to the developing area. After the rotation of the developer carrier 3a is started and a bias voltage is applied, the cam 8a rotates, and the first developing device 2a moves the magnetic brush and the electrostatic latent image carrier 1 on the developer carrier 3a. Moves to the position where touches. At this time, a bias electric field is generated between the developer carrier 3a and the electrostatic latent image carrier 1, and
The charged toner adheres to the electrostatic latent image on the electrostatic latent image holding member 1 to visualize the electrostatic latent image.
【００２５】静電潜像保持体１が回転し、静電潜像の形
成された部分が現像領域を通過すると現像は終了し、カ
ム８ａが回転して第１の現像装置２ａを磁気ブラシと静
電潜像保持体とが接触しない位置へ戻す。静電潜像保持
体１にはさらに他の色に対応する静電潜像が形成され、
これに対応する現像装置すなわち第２の現像装置２ｂが
駆動される。この第２の現像装置２ｂの動作の順序は図
４に示すように第１の現像装置２ａの場合と同じであ
る。このような工程が現像する色の種類と同じ数だけ繰
り返し行われ、静電潜像保持体１上にカラー画像が形成
される。このカラー画像は転写装置（図示せず）によっ
て用紙上に転写され、定着装置によって融着される。When the electrostatic latent image holding member 1 rotates and the portion on which the electrostatic latent image is formed passes through the developing area, the development is completed, and the cam 8a rotates to move the first developing device 2a to the magnetic brush. Return to a position where it does not come into contact with the electrostatic latent image holder. An electrostatic latent image corresponding to another color is formed on the electrostatic latent image holding member 1,
The corresponding developing device, that is, the second developing device 2b is driven. The order of operation of the second developing device 2b is the same as that of the first developing device 2a as shown in FIG. Such a process is repeated by the same number as the types of colors to be developed, and a color image is formed on the electrostatic latent image holding member 1. This color image is transferred onto a sheet by a transfer device (not shown) and fused by a fixing device.
【００２６】このような現像方法を行なった場合におけ
るキャリアの静電潜像保持体への付着量を調査するた
め、図３に示すように現像装置２ａ、２ｂ、２ｃが静電
潜像保持体１と対向する位置よりも静電潜像保持体１の
回転方向における下流側にキャリアの補集手段１２を設
け、これによって補集されたキャリアの量を、従来の現
像方法（現像剤担持体上の磁気ブラシが静電潜像保持体
と接触した状態で現像剤担持体の動作の開始・停止およ
びバイアス電圧の印加の開始・解除を行なう）を行なっ
た場合と比較する。As shown in FIG. 3, the developing devices 2a, 2b, and 2c are used to investigate the amount of the carrier adhered to the electrostatic latent image holder when such a developing method is performed. A carrier collection means 12 is provided downstream of the position facing the image carrier 1 in the rotational direction of the electrostatic latent image holding member 1, and the amount of the collected carrier is reduced by the conventional developing method (developer carrier). (The start and stop of the operation of the developer carrier and the start and release of the bias voltage are performed in a state where the upper magnetic brush is in contact with the electrostatic latent image holder).
【００２７】図５は１００回の現像を行なう間に補集手
段１２で補集されたキャリアの量を重量で示したもので
あり、本発明の実施例においては補集されたキャリアが
著しく少なくなっている。このように本実施例の現像方
法では、それぞれの色の現像において静電潜像保持体１
に現像剤が多量に付着したり、キャリアの電荷注入によ
る静電潜像保持体への付着が防止されるので、静電潜像
保持体１の回転にムラが生じるのを防止でき、色ずれ等
のない良好なカラー画像が形成される。FIG. 5 shows, by weight, the amount of carrier collected by the collecting means 12 during 100 developments. In the embodiment of the present invention, the amount of collected carrier is extremely small. Has become. As described above, according to the developing method of the present embodiment, the electrostatic latent image holder 1
A large amount of the developer is prevented from adhering to the surface of the electrostatic latent image holding member 1 due to the carrier injection, and the rotation of the electrostatic latent image holding member 1 can be prevented from being uneven. And a good color image without the like is formed.
【００２８】[0028]
【発明の効果】以上説明したように、本発明の現像方法
では、現像剤担持体の動作開始時および停止時、ならび
にバイアス電圧の印加開始時および解除時に、現像剤担
持体表面に形成された磁気ブラシが静電潜像保持体と接
触していないので、多量の現像剤が静電潜像保持体に付
着するのが防止でき、良好な画像が得られる。また、バ
イアス電圧印加開始時に、現像剤担持体は、表面の磁気
ブラシが静電潜像保持体と接触しない程度に離れてお
り、バイアス電圧下の放電による静電潜像保持体表面の
損傷が防止され、画像に欠陥が生じるのを防ぐことがで
きる。さらに、現像剤担持体が動作していない状態で磁
気ブラシが静電潜像保持体と接触することがなく、キャ
リアへの電荷注入によってキャリアが静電潜像保持体に
付着して画像に欠陥が生じるのを防止できる。As described above, according to the developing method of the present invention, when the operation of the developer carrier is started and stopped, and when the application of the bias voltage is started and released, the developer carrier is formed on the surface of the developer carrier. Since the magnetic brush is not in contact with the electrostatic latent image holder, a large amount of developer can be prevented from adhering to the electrostatic latent image holder, and a good image can be obtained. Also, at the start of bias voltage application, the developer carrier is so far away that the magnetic brush on the surface does not contact the electrostatic latent image holder, and damage to the surface of the electrostatic latent image holder due to discharge under the bias voltage is reduced. This prevents the occurrence of defects in the image. Furthermore, the magnetic brush does not come into contact with the electrostatic latent image holding member in a state where the developer holding member is not operating, and the carrier is attached to the electrostatic latent image holding member due to charge injection into the carrier, resulting in image defects. Can be prevented from occurring.
【図１】本発明の現像方法を説明するためのタイミング
図である。FIG. 1 is a timing chart for explaining a developing method of the present invention.
【図２】本発明の一実施例である現像方法に使用するこ
とができる現像装置の一例を示す概略構成図である。FIG. 2 is a schematic configuration diagram illustrating an example of a developing device that can be used in a developing method according to an embodiment of the present invention.
【図３】本発明の一実施例である現像方法に使用するこ
とができるカラー画像形成装置の一部を示す概略構成図
である。FIG. 3 is a schematic configuration diagram illustrating a part of a color image forming apparatus that can be used in a developing method according to an embodiment of the present invention.
【図４】図３に示すカラー画像形成装置において、本発
明の現像方法を実施した例を示すタイミング図である。FIG. 4 is a timing chart showing an example in which the developing method of the present invention is implemented in the color image forming apparatus shown in FIG.
【図５】図３に示すカラー画像形成装置において、本発
明の現像方法を実施した場合の効果を従来例と比較して
示す図である。FIG. 5 is a diagram illustrating an effect obtained when the developing method of the present invention is performed in the color image forming apparatus illustrated in FIG. 3 in comparison with a conventional example.
【図６】従来の現像方法を説明するためのタイミング図
である。FIG. 6 is a timing chart for explaining a conventional developing method.
【図７】バイアス電圧の印加開始時および解除時におけ
る電圧の変動を示す図である。FIG. 7 is a diagram illustrating voltage fluctuations at the time of starting and canceling application of a bias voltage.
１ 静電潜像保持体 ２ 現像装置 ３ 現像剤担持体 ４ 現像剤規制部材 ５ スクリュウオーガー ６ スクリュウオーガー ７ ハウジング ８ カム REFERENCE SIGNS LIST 1 electrostatic latent image holder 2 developing device 3 developer carrier 4 developer regulating member 5 screw auger 6 screw auger 7 housing 8 cam
───────────────────────────────────────────────────── フロントページの続き (72)発明者 山下 孝幸 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 (56)参考文献 特開 平１−202780（ＪＰ，Ａ) 特開 平２−179663（ＪＰ，Ａ) 実開 昭64−32560（ＪＰ，Ｕ) (58)調査した分野(Int.Cl.6，ＤＢ名) G03G 15/08 - 15/095 ──────────────────────────────────────────────────続 き Continuation of the front page (72) Inventor Takayuki Yamashita 2274 Hongo, Ebina-shi, Kanagawa Fuji Xerox Co., Ltd. Ebina Works (56) References JP-A-1-202780 (JP, A) JP-A-2-2- 179663 (JP, A) Actually open sho 64-32560 (JP, U) (58) Field surveyed (Int. Cl. 6 , DB name) G03G 15/08-15/095
Claims (1)
像剤の磁気ブラシを形成して現像剤を搬送する現像剤担
持体と、露光によって表面に静電潜像が形成される静電
潜像保持体とが近接して対向する位置で、前記磁気ブラ
シを前記静電潜像保持体表面に接触させるとともに、前
記静電潜像保持体と現像剤担持体との間にバイアス電圧
を印加し、帯電した現像剤を前記静電潜像に付着させて
可視化する現像方法において、前記静電潜像を現像しな
いときは、前記現像剤担持体を、前記磁気ブラシが静電
潜像保持体に接触しない位置に保持し、前記静電潜像保
持体上の静電潜像を現像するときに、バイアス電圧の印
加、および現像剤担持体の動作を開始し、その後現像剤
担持体を、前記磁気ブラシが動作中の前記静電潜像保持
体と接触する位置に移動させて現像を行ない、現像終了
後、再び前記現像剤担持体を、前記磁気ブラシが動作中
の前記静電潜像保持体と接触しない位置に戻し、その後
バイアス電圧の印加解除、および現像剤担持体の動作の
停止を行なうことを特徴とする現像方法。1. A developer carrier having a built-in magnet roll, forming a magnetic brush of a two-component developer on the surface and transporting the developer, and an electrostatic latent image formed on the surface by exposure to an electrostatic latent image At a position where the image carrier is close to and opposed to the image carrier, the magnetic brush is brought into contact with the surface of the electrostatic latent image carrier, and a bias voltage is applied between the electrostatic latent image carrier and the developer carrier. In the developing method in which a charged developer is adhered to the electrostatic latent image to visualize the developer, when the electrostatic latent image is not developed, the developer brush may be attached to the electrostatic latent image holder by the magnetic brush. When the electrostatic latent image on the electrostatic latent image holding body is developed, the bias voltage is applied, and the operation of the developer holding body is started. The magnetic brush is moved to a position where the magnetic brush comes into contact with the electrostatic latent image holding member during operation. After the development is completed, the developer carrier is returned to a position where the magnetic brush is not in contact with the electrostatic latent image holding member in operation, and then the application of the bias voltage is stopped, and the developer is removed. A developing method, wherein the operation of the carrier is stopped.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP12447091A JP2903770B2 (en) | 1991-04-30 | 1991-04-30 | Development method |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP12447091A JP2903770B2 (en) | 1991-04-30 | 1991-04-30 | Development method |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH04328783A JPH04328783A (en) | 1992-11-17 |
| JP2903770B2 true JP2903770B2 (en) | 1999-06-14 |
Family
ID=14886321
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP12447091A Expired - Fee Related JP2903770B2 (en) | 1991-04-30 | 1991-04-30 | Development method |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP2903770B2 (en) |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP3413314B2 (en) | 1994-10-21 | 2003-06-03 | 株式会社リコー | Image forming device |
| JP5750870B2 (en) | 2010-11-10 | 2015-07-22 | 富士ゼロックス株式会社 | Image forming apparatus |
-
1991
- 1991-04-30 JP JP12447091A patent/JP2903770B2/en not_active Expired - Fee Related
Also Published As
| Publication number | Publication date |
|---|---|
| JPH04328783A (en) | 1992-11-17 |
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