JP3455337B2 - Developing unit - Google Patents
Developing unitInfo
- Publication number
- JP3455337B2 JP3455337B2 JP22781995A JP22781995A JP3455337B2 JP 3455337 B2 JP3455337 B2 JP 3455337B2 JP 22781995 A JP22781995 A JP 22781995A JP 22781995 A JP22781995 A JP 22781995A JP 3455337 B2 JP3455337 B2 JP 3455337B2
- Authority
- JP
- Japan
- Prior art keywords
- developer
- stirring member
- developing sleeve
- toner
- developing
- 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
- Dry Development In Electrophotography (AREA)
Description
【０００１】[0001]
【発明の属する技術分野】本発明は、複写機やプリンタ
等の電子写真装置における現像ユニットに関し、詳しく
は、二つの攪拌部材で現像剤を攪拌・搬送して現像スリ
ーブ、感光体へと供給する２軸攪拌スクリュータイプの
現像ユニットに関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a developing unit in an electrophotographic apparatus such as a copying machine or a printer, and more specifically, a developer is agitated and conveyed by two agitating members and supplied to a developing sleeve and a photoconductor. The present invention relates to a biaxial stirring screw type developing unit.
【０００２】[0002]
【従来の技術】この種の現像ユニットでは、感光体面上
にトナーを供給して現像するための現像スリーブが備え
られているとともに、この現像スリーブの軸線に沿って
二つの現像剤攪拌部材が並設されている。各現像剤攪拌
部材は回転軸と攪拌羽根とからなるスクリュー構造を有
し、互いに軸方向逆向きに現像剤を攪拌・搬送するよう
に構成されている。各現像剤攪拌部材の間には、軸方向
両端において現像剤の連絡通路を形成する仕切部材が設
けられており、これらの連絡通路を介して各現像剤攪拌
部材間での現像剤の受け渡しがなされるようになってい
る。従って、現像剤は各現像剤攪拌部材で攪拌されなが
らループ状に循環し、現像スリーブに近い現像剤攪拌部
材から現像スリーブ、感光体へと供給される。2. Description of the Related Art A developing unit of this type is provided with a developing sleeve for supplying toner to the surface of a photosensitive member for development, and two developer stirring members are arranged in parallel along the axis of the developing sleeve. It is set up. Each developer stirring member has a screw structure including a rotating shaft and stirring blades, and is configured to stir and convey the developer in axially opposite directions. Partition members that form communication passages for the developer are provided at both ends in the axial direction between the developer stirring members, and the developer is transferred between the developer stirring members via these communication passages. It is supposed to be done. Therefore, the developer circulates in a loop while being stirred by each developer stirring member, and is supplied from the developer stirring member near the developing sleeve to the developing sleeve and the photoconductor.
【０００３】[0003]
【発明が解決しようとする課題】ところで、この種の現
像ユニット内に収容される現像剤は、キャリアと呼ばれ
る小さな鉄球と、トナーよりなる二成分構成であり、攪
拌によるキャリアの摩擦帯電でキャリアに付着している
トナーの比電荷（Ｑ／Ｍ）を上げるようになっている
が、上述のような従来の現像剤攪拌構成では、トナーの
比電荷（Ｑ／Ｍ）の立ち上げ能力が十分ではない。この
ため、Ｑ／Ｍの不安定な（低い）トナーが残存し、これ
が感光体面上の地肌部に当たる所（本来トナーが付着し
てはならない所）に付着し、画像上にいわゆる「地肌汚
れ」が発生する、という問題があった。The developer contained in this type of developing unit has a two-component structure consisting of a small iron ball called a carrier and a toner. The specific charge (Q / M) of the toner adhering to the toner is increased, but the conventional developer stirring structure as described above has a sufficient ability to raise the specific charge (Q / M) of the toner. is not. For this reason, an unstable (low) Q / M toner remains, and this toner adheres to the surface of the photoconductor surface where it contacts the surface (where the toner should not originally adhere), resulting in so-called "background stain" on the image. There is a problem that occurs.
【０００４】本発明は、このような地肌汚れの発生を抑
制でき、画像品質の向上を図ることができる現像ユニッ
トの提供を、その目的とする。An object of the present invention is to provide a developing unit capable of suppressing the occurrence of such background stain and improving the image quality.
【０００５】[0005]
【課題を解決するための手段】本発明は、本来の循環流
れから現像剤を導いてトナー比電荷を上昇させ、比電荷
が十分に立ち上げられた現像剤を再び本来の循環流れに
組み入れて現像剤の全体的な比電荷の立ち上がりを得
る、という考えに立っている。この考えの下、請求項１
記載の発明では、感光体面上へトナーを供給して現像す
るための現像スリーブと、この現像スリーブの軸線方向
に沿って延び前後反対方向に現像剤を攪拌・搬送する二
つの現像剤攪拌部材を設け、現像スリーブに近い方を第
１の現像剤攪拌部材、遠い方を第２の現像剤攪拌部材と
するとともに、これら第１の現像剤攪拌部材と第２の現
像剤攪拌部材との間に、両端に現像剤の連絡通路を確保
する形状の仕切部材を設け、現像剤がループ状に循環す
るように構成した現像ユニットにおいて、前記第２の現
像剤攪拌部材に沿う位置に、内側に磁石が配設された現
像剤立上げ用現像スリーブと現像剤立上げ用ドクターブ
レードを配置する、という構成を採っている。請求項２
記載の発明では、請求項１記載の構成において、前記現
像剤立上げ用現像スリーブと現像剤立上げ用ドクターブ
レードを、第２の現像剤攪拌部材から第１の現像剤攪拌
部材へ現像剤を受け渡す側に配置する、という構成を採
っている。SUMMARY OF THE INVENTION In the present invention, the developer is introduced from the original circulating flow to increase the toner specific charge, and the developer having a sufficiently increased specific charge is reintroduced into the original circulating flow. It is based on the idea of obtaining the rise of the overall specific charge of the developer. Under this idea, claim 1
In the invention described above, there are provided a developing sleeve for supplying the toner onto the surface of the photoconductor for development, and two developer agitating members extending along the axial direction of the developing sleeve and agitating and transporting the developer in the opposite directions. The first developer stirring member is provided closer to the developing sleeve and the second developer stirring member is further away from the developing sleeve. The first developer stirring member and the second developer stirring member are provided between the first developer stirring member and the second developer stirring member. In a developing unit in which partition members having a shape for ensuring a communication passage for the developer are provided at both ends and the developer circulates in a loop , a magnet is provided inside at a position along the second developer stirring member. The present invention employs a configuration in which a developing sleeve for developing an image agent and a doctor blade for developing a developer are disposed. Claim 2
According to the invention described in claim 1, in the configuration according to claim 1, the developer starting development sleeve and the developer starting doctor blade are provided with a developer from the second developer stirring member to the first developer stirring member. The configuration is such that it is placed on the delivery side.
【０００６】[0006]
【実施例】以下、本発明の一実施例を図１乃至図５に基
づいて説明する。図１に示すように、感光体２に沿って
その表面上に現像用のトナーを供給する現像スリーブ４
が備えられ、この現像スリーブ４の上部には当該現像ス
リーブ４に供給された現像剤を一定の層厚にカットする
ドクターブレード５が軸線に沿って設けられている。ま
た、現像スリーブ４に沿って第１の現像剤攪拌部材６
と、第２の現像剤攪拌部材８とが並設されており、さら
に第２の現像剤攪拌部材８に沿って現像剤立上げ用現像
スリーブ１０が設けられているとともに当該現像剤立上
げ用現像スリーブ１０の軸線に沿って現像剤立上げ用ド
クターブレード１２が設けられている。第１の現像剤攪
拌部材６と第２の現像剤攪拌部材８との間には、軸方向
両端に現像剤の連絡通路１４，１６（図４参照）を確保
する形状の仕切部材１８が設けられている。そして、上
述の現像スリーブ４以下を主要部として現像ユニットが
構成されている。DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. As shown in FIG. 1, a developing sleeve 4 for supplying developing toner along the surface of the photoconductor 2
A doctor blade 5 for cutting the developer supplied to the developing sleeve 4 into a constant layer thickness is provided along the axis line on the developing sleeve 4. In addition, the first developer stirring member 6 is provided along the developing sleeve 4.
And a second developer stirring member 8 are juxtaposed with each other, and a developer starting development sleeve 10 is provided along the second developer stirring member 8 as well as the developer starting member. A developer starting doctor blade 12 is provided along the axis of the developing sleeve 10. Between the first developer stirring member 6 and the second developer stirring member 8, there is provided a partition member 18 having a shape that secures the developer communication passages 14, 16 (see FIG. 4) at both axial ends. Has been. A developing unit is configured with the developing sleeve 4 and the following parts as a main part.
【０００７】図１において、符号２０は帯電ローラ、２
２は転写ローラ、２４は除電針、２５はクリーニング装
置、２６はクリーニングブレード、２８はトナーリサイ
クルベルト、３０は透磁率測定センサをそれぞれ示す。
図１に基づいて作像系の基本的な動きについて説明す
る。まず、感光体２は図示しない除電部から照射される
除電光３２によって除電され、表面電位が０〜１５０Ｖ
の基準電位に平均化される。次に、感光体２は帯電ロー
ラ２０により帯電され、表面電位が−８５０Ｖ前後とな
る。そして、図示しない露光部より照射される光３４で
露光され、光３４が照射された部分（画像部分）は表面
電位が０〜２００Ｖとなる。現像スリーブ４には−６０
０Ｖ前後のバイアスがかけられているため、画像部分に
現像スリーブ４上のトナーが付着する。トナー像が形成
された感光体２は回転移動し、これに伴って、図示しな
い給紙部から用紙先端部と画像先端部とが転写ローラ２
２部位で一致するようなタイミングで用紙が送られる。
そして、転写ローラ２２部位で感光体２の表面のトナー
像が用紙へ転写される。転写後、用紙は図示しない定着
部へ送られ、熱と圧力でトナーが溶融して用紙に定着
し、コピーとして排出される。転写分離の際、用紙は除
電針２４で除電され、感光体２からの分離が助勢され
る。感光体２上に残った残留トナーは、クリーニングブ
レード２６により掻き落とされ、感光体２はトナーの無
い状態で再び次の作像工程へ移る。上記感光体２、帯電
ローラ２０、現像スリーブ４等で構成される現像ユニッ
ト、クリーニング装置２５等は、一体に形成された感光
体回りケース６０内に納められている（図５）。In FIG. 1, reference numeral 20 is a charging roller, 2
2 is a transfer roller, 24 is a discharging needle, 25 is a cleaning device, 26 is a cleaning blade, 28 is a toner recycling belt, and 30 is a magnetic permeability measuring sensor.
The basic movement of the image forming system will be described with reference to FIG. First, the photoconductor 2 is neutralized by the neutralization light 32 emitted from a neutralization unit (not shown), and the surface potential is 0 to 150V.
Are averaged to the reference potential of. Next, the photoconductor 2 is charged by the charging roller 20, and the surface potential becomes about -850V. Then, the portion (image portion) exposed to the light 34 emitted from an exposure unit (not shown) has a surface potential of 0 to 200V. -60 for the developing sleeve 4.
Since the bias of about 0 V is applied, the toner on the developing sleeve 4 adheres to the image portion. The photoconductor 2 on which the toner image is formed is rotationally moved, and along with this, the transfer roller 2 moves from the paper feed unit (not shown) to the paper front end and the image front end.
The paper is sent at a timing such that the two parts match.
Then, the toner image on the surface of the photoconductor 2 is transferred to the sheet at the transfer roller 22 portion. After the transfer, the paper is sent to a fixing unit (not shown), the toner is melted by heat and pressure, the toner is fixed on the paper, and the paper is ejected as a copy. At the time of transfer separation, the charge of the sheet is removed by the charge removing needle 24, and the separation from the photoconductor 2 is assisted. The residual toner remaining on the photoconductor 2 is scraped off by the cleaning blade 26, and the photoconductor 2 moves to the next image forming step again without the toner. The developing unit including the photoconductor 2, the charging roller 20, the developing sleeve 4, and the cleaning device 25 are housed in an integrally formed photoconductor case 60 (FIG. 5).
【０００８】現像スリーブ４（アルミ円筒）の表面は、
無垢又は現像剤の搬送性を上げるために凹凸（例えばＶ
形溝）に形成されている。現像スリーブ４の内側には、
図３に示すように、円柱部材３６が設けられており、こ
の円柱部材３６には周方向に間隔をおいて５個の磁石Ｍ
1，Ｍ2，Ｍ3，Ｍ5，Ｍ6 配設されている。これによっ
て、現像スリーブ４の円周上には磁力線Ｐ1，Ｐ2，
Ｐ3，Ｐ4，Ｐ5，Ｐ6 が存在し、一定の磁力分布が現れ
るようになっている。ドクターブレード５は、現像スリ
ーブ４に対して略法線方向に調整可能な構成となってい
る。現像スリーブ４の一端部（前端部又は手前側端部）
には、現像スリーブ４内に設けられた磁石Ｍの回転方向
を決める機能を有するとともにドクターブレード５を調
整可能に支持する支持部材３８が設けられており、他端
部には、現像スリーブ４の回転を受ける軸受の機能を有
するとともにドクターブレード５を調整可能に支持する
軸受が圧入された支持部材４０が設けられている（図
５）。ドクターブレード５が法線方向に調整可能に設け
られていることにより、ドクターブレード５の調整量
と、現像スリーブ４とドクターブレード５とのギャップ
Ｇは一対一で対応する。図３において、符号４２は入口
シール、４４は現像ケーシング部をそれぞれ示す。The surface of the developing sleeve 4 (aluminum cylinder) is
Solid or uneven (for example, V
Shaped groove). Inside the developing sleeve 4,
As shown in FIG. 3, a columnar member 36 is provided, and the columnar member 36 has five magnets M at intervals in the circumferential direction.
1 , M 2 , M 3 , M 5 , and M 6 are arranged. As a result, on the circumference of the developing sleeve 4, the magnetic force lines P 1 , P 2 ,
P 3 , P 4 , P 5 , and P 6 exist, and a constant magnetic force distribution appears. The doctor blade 5 is configured to be adjustable in a substantially normal direction with respect to the developing sleeve 4. One end of the developing sleeve 4 (front end or front end)
Is provided with a support member 38 that has a function of determining the rotation direction of the magnet M provided in the developing sleeve 4 and that supports the doctor blade 5 in an adjustable manner. A support member 40 having a function of a bearing for receiving rotation and press-fitting a bearing for adjustingably supporting the doctor blade 5 is provided (FIG. 5). Since the doctor blade 5 is provided so as to be adjustable in the normal direction, the adjustment amount of the doctor blade 5 and the gap G between the developing sleeve 4 and the doctor blade 5 have a one-to-one correspondence. In FIG. 3, reference numeral 42 is an inlet seal, and 44 is a developing casing portion.
【０００９】第１の現像剤攪拌部材６と第２の現像剤攪
拌部材８は、図４及び図５から明らかなように、それぞ
れ回転軸４６，４８と、一部が切り欠かれた楕円板形状
の羽根５０，５２とから成るスクリュー形状に構成され
ており、また、第１の現像剤攪拌部材６は現像剤を手前
方向（矢印Ｆ方向）に、第２の現像剤攪拌部材８は現像
剤を奥行方向（矢印Ｂ方向）に攪拌しながら搬送するよ
うに構成・設定されている。第１の現像剤攪拌部材６と
第２の現像剤攪拌部材８で攪拌・搬送される現像剤は、
仕切部材１８によって確保された連絡通路１４，１６に
おいてそれぞれ相手側に入り込み、これによって現像剤
はループ状に循環する。現像スリーブ４に供給された余
分な現像剤は第１の現像剤攪拌部材６で回収され、再び
循環流に乗せられる。現像剤はキャリアと呼ばれる小さ
な鉄球とトナーよりなる二成分構成である。現像剤中の
トナー濃度を透磁率測定センサ３０で検出し、トナーが
不足している場合には、検出信号に基づいて図示しない
トナー補給部より現像ユニット内へ、具体的には第２の
現像剤攪拌部材８の端部へトナーが供給されるようにな
っている。図４において、符号７０，７２，７４は回転
伝達用の歯車を示す。As is apparent from FIGS. 4 and 5, the first developer stirring member 6 and the second developer stirring member 8 have rotary shafts 46 and 48, respectively, and an elliptical plate partially cut away. The first developer stirring member 6 is for developing the developer in the front direction (arrow F direction), and the second developer stirring member 8 is for developing the screw. It is configured and set to convey the agent while stirring it in the depth direction (arrow B direction). The developer stirred and conveyed by the first developer stirring member 6 and the second developer stirring member 8 is
Each of the communication passages 14 and 16 secured by the partition member 18 enters into the other side, whereby the developer circulates in a loop. The excess developer supplied to the developing sleeve 4 is recovered by the first developer stirring member 6 and is put on the circulating flow again. The developer has a two-component structure composed of small iron balls called a carrier and toner. The toner concentration in the developer is detected by the magnetic permeability measurement sensor 30, and when the toner is insufficient, the toner replenishment unit (not shown) enters the developing unit, specifically the second developing unit, based on the detection signal. The toner is supplied to the end of the agent stirring member 8. In FIG. 4, reference numerals 70, 72 and 74 denote gears for transmitting rotation.
【００１０】また、クリーニングブレード２６で掻き落
とされてクリーニング装置２５に回収された残留トナー
は、図示しないトナー搬送コイルで奥側より手前側へ搬
送され、リサイクルトナー搬送部５４へ送られる。リサ
イクルトナー搬送部５４は、図１及び図５に示すよう
に、駆動軸５６と、従動軸５８及びこれらの軸間に掛け
られた、送り羽根２８ａを有するトナーリサイクルベル
ト２８等から構成されており、奥側から送られてきたト
ナーは、トナーリサイクルベルト２８によって第２の現
像剤攪拌部材８の手前側端部へ送られ、トナーがリサイ
クルされる仕組みになっている。リサイクルトナー搬送
部５４も感光体回りケース６０と一体化されており、こ
れにより別体とした時の接合部でのトナー漏れの心配が
なく、また、これを防止するためのスポンジ部材の追加
等を行わなくてよい。また、一体化されているので、組
付性も向上する。Further, the residual toner scraped off by the cleaning blade 26 and collected by the cleaning device 25 is transported from the back side to the front side by a toner transport coil (not shown), and is sent to the recycled toner transport section 54. As shown in FIGS. 1 and 5, the recycled toner transport unit 54 includes a drive shaft 56, a driven shaft 58, and a toner recycling belt 28 having a feed blade 28a that is hung between these shafts. The toner sent from the back side is sent to the front end of the second developer stirring member 8 by the toner recycling belt 28, and the toner is recycled. The recycled toner transport unit 54 is also integrated with the photosensitive member case 60, so that there is no fear of toner leakage at the joint portion when it is separated, and a sponge member is added to prevent this. You don't have to. Moreover, since it is integrated, the assembling property is also improved.
【００１１】図４及び図５に示すように、現像剤立上げ
用現像スリーブ１０は、第２の現像剤攪拌部材８の奥
側、すなわち、第１の現像剤攪拌部材６へトナーを受け
渡す連絡通路１６がある側に第２の現像剤攪拌部材８に
沿って平行に配置されており、現像剤立上げ用ドクター
ブレード１２もこれに沿って配置されている。図２に示
すように、現像剤立上げ用現像スリーブ１０の内側に
は、現像スリーブ４と同様に、円柱部材６２が設けられ
ているとともに磁石Ｍ1，Ｍ2，Ｍ3，Ｍ5，Ｍ6 が配設さ
れている。磁極配置とドクターブレードの向きは、現像
スリーブ４側との間で左右対称となっている。また、現
像剤立上げ用現像スリーブ１０の前後端部には、現像ス
リーブ４と同様に機能的に対応する支持部材６４，６６
が設けられている。なお、図２及び図３中、符号６８は
入口シールカバーを示す。As shown in FIGS. 4 and 5, the developer start-up developing sleeve 10 transfers the toner to the inner side of the second developer stirring member 8, that is, the first developer stirring member 6. On the side where the communication passage 16 is provided, it is arranged in parallel along the second developer stirring member 8, and the developer starting doctor blade 12 is also arranged along this. As shown in FIG. 2, like the developing sleeve 4, a cylindrical member 62 is provided inside the developing sleeve 10 for developing the developer, and magnets M 1 , M 2 , M 3 , M 5 and M are provided. 6 are arranged. The arrangement of the magnetic poles and the orientation of the doctor blade are symmetrical with respect to the developing sleeve 4 side. Further, the front and rear ends of the developing sleeve 10 for developing the developer are provided with supporting members 64, 66 which are functionally corresponding to each other similarly to the developing sleeve 4.
Is provided. 2 and 3, reference numeral 68 indicates an inlet seal cover.
【００１２】次に、現像剤立上げ用現像スリーブ１０等
によるトナー比電荷の立ち上げ動作について説明する。
第２の現像剤攪拌部材８側における現像剤は、現像剤立
上げ用現像スリーブ１０上に保持される形で回転移動さ
れ、現像剤立上げ用ドクターブレード１２で一定の層厚
にカットされる。この時、現像剤が現像剤立上げ用ドク
ターブレード１２と強制的に接触して摩擦が生じるた
め、キャリアが摩擦帯電し、キャリアに付着しているト
ナーのトナー比電荷（Ｑ／Ｍ）が上昇する。このＱ／Ｍ
が十分に立ち上がった現像剤が第２の現像剤攪拌部材８
より第１の現像剤攪拌部材６へ送られ、現像スリーブ４
を介して感光体２へ供給され、現像される。実験の結
果、地肌汚れの発生を抑制できることが確認された。現
像剤立上げ用現像スリーブ１０等のいわゆるトナー比電
荷立上げ機構は、第２の現像剤攪拌部材８に沿って任意
の位置に配置することができるが、本実施例のように、
Ｑ／Ｍが立ち上がっている現像剤を直ちに、無駄なく正
規の現像ルートへ移行させる観点から、第１の現像剤攪
拌部材６へ現像剤の受け渡しが行われる側へ配置して、
最短距離供給の形態とするのが望ましい。なお、現像剤
立上げ用現像スリーブ１０の磁石の配置数については、
必ずしも上記実施例で示したようにする必要はなく、場
合によって少なくすることも可能である。Next, the operation of raising the toner specific charge by the developing sleeve 10 for developing the developer will be described.
The developer on the side of the second developer stirring member 8 is rotatably moved while being held on the developer start-up developing sleeve 10 and cut into a constant layer thickness by the developer start-up doctor blade 12. . At this time, the developer is forcibly brought into contact with the doctor blade 12 for starting up the developer to cause friction, so that the carrier is frictionally charged and the toner specific charge (Q / M) of the toner adhering to the carrier is increased. To do. This Q / M
The developer that has sufficiently risen is the second developer stirring member 8
Is sent to the first developer stirring member 6 from the developing sleeve 4
And is supplied to the photoconductor 2 through the developer and is developed. As a result of the experiment, it was confirmed that the generation of background stains can be suppressed. A so-called toner specific charge raising mechanism such as the developer raising developing sleeve 10 can be arranged at an arbitrary position along the second developer stirring member 8, but as in this embodiment,
From the viewpoint of immediately transferring the developer whose Q / M has risen to the regular developing route without waste, the developer is placed on the side where the developer is transferred to the first developer stirring member 6,
The form of shortest distance supply is desirable. Regarding the number of magnets arranged in the developing sleeve 10 for developing the developer,
It is not always necessary to make it as shown in the above-mentioned embodiment, and it is possible to reduce it as the case may be.
【００１３】[0013]
【発明の効果】請求項１記載の発明によれば、第２の現
像剤攪拌部材に沿って現像剤立上げ用現像スリーブと現
像剤立上げ用ドクターブレードを配置する構成としたの
で、トナー比電荷が十分に立ち上げられた現像剤が第２
の現像剤攪拌部材から第１の現像剤攪拌部材へ送られて
現像スリーブに供給され、感光体に供給される。これに
よって、感光体面上の地肌部に当たる所（本来トナーが
付着してはならない所）にトナーが付着することが抑制
され、画像上のいわゆる地肌汚れの抑制によって画像品
質の向上を図ることができる。請求項２記載の発明によ
れば、トナー比電荷が十分に立ち上げられた現像剤が無
駄なく有効に現像スリーブへ供給されるので、地肌汚れ
の抑制を一層向上させることができる。According to the first aspect of the present invention, since the developing sleeve for developing the developer and the doctor blade for raising the developer are arranged along the second developer stirring member, the toner ratio is increased. The second is the developer whose charge has been sufficiently raised.
From the developer stirring member to the first developer stirring member, is supplied to the developing sleeve, and is supplied to the photoconductor. As a result, it is possible to prevent the toner from adhering to a portion on the surface of the photoconductor that hits the background portion (where the toner should not originally adhere), and it is possible to improve image quality by suppressing so-called background stain on the image. . According to the second aspect of the present invention, the developer whose toner specific charge has been sufficiently raised is effectively supplied to the developing sleeve without waste, so that the background stain can be further suppressed.
【図１】本発明の一実施例を示す現像ユニットの概要断
面図である。FIG. 1 is a schematic sectional view of a developing unit showing an embodiment of the present invention.
【図２】現像スリーブと現像剤立上げ用現像スリーブと
の対称性を示す概要断面図である。FIG. 2 is a schematic cross-sectional view showing the symmetry between the developing sleeve and the developer starting developing sleeve.
【図３】現像スリーブの磁力分布を示す要部断面図であ
る。FIG. 3 is a cross-sectional view of essential parts showing a magnetic force distribution of a developing sleeve.
【図４】上面側からみた一部省略の断面図である。FIG. 4 is a partially omitted cross-sectional view seen from the upper surface side.
【図５】一部省略の斜視図である。FIG. 5 is a partially omitted perspective view.
２ 感光体 ４ 現像スリーブ ６ 第１の現像剤攪拌部材 ８ 第２の現像剤攪拌部材 １０ 現像剤立上げ用現像スリーブ １２ 現像剤立上げ用ドクターブレード １４，１６ 連絡通路 １８ 仕切部材 2 photoconductor 4 Development sleeve 6 First developer stirring member 8 Second developer stirring member 10 Developer start-up developing sleeve 12 Doctor blade for developing developer 14, 16 connecting passage 18 Partition member
───────────────────────────────────────────────────── フロントページの続き (72)発明者 丹沢 節 東京都大田区中馬込１丁目３番６号・株 式会社リコー内 (72)発明者 植野 博 東京都大田区中馬込１丁目３番６号・株 式会社リコー内 (56)参考文献 特開 平８−76596（ＪＰ，Ａ) 特開 平５−127537（ＪＰ，Ａ) 特開 平６−89058（ＪＰ，Ａ) (58)調査した分野(Int.Cl.7，ＤＢ名) G03G 15/08 110 G03G 15/08 112 G03G 15/08 504 G03G 15/08 507 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Setsu Tanzawa 1-3-6 Nakamagome, Ota-ku, Tokyo, Ricoh Co., Ltd. (72) Hiroshi Ueno 1-3-6 Nakamagome, Ota-ku, Tokyo No./Shared company Ricoh (56) References JP-A-8-76596 (JP, A) JP-A-5-127537 (JP, A) JP-A-6-89058 (JP, A) (58) Field (Int.Cl. 7 , DB name) G03G 15/08 110 G03G 15/08 112 G03G 15/08 504 G03G 15/08 507
Claims (2)
めの現像スリーブと、この現像スリーブの軸線方向に沿
って延び前後反対方向に現像剤を攪拌・搬送する二つの
現像剤攪拌部材を設け、現像スリーブに近い方を第１の
現像剤攪拌部材、遠い方を第２の現像剤攪拌部材とする
とともに、これら第１の現像剤攪拌部材と第２の現像剤
攪拌部材との間に、両端に現像剤の連絡通路を確保する
形状の仕切部材を設け、現像剤がループ状に循環するよ
うに構成した現像ユニットにおいて、 前記第２の現像剤攪拌部材に沿う位置に、内側に磁石が
配設された現像剤立上げ用現像スリーブと現像剤立上げ
用ドクターブレードを配置したことを特徴とする現像ユ
ニット。1. A developing sleeve for supplying toner onto the surface of a photosensitive member for development, and two developer stirring members extending along the axial direction of the developing sleeve and stirring and conveying the developer in opposite directions. The first developer stirring member is provided closer to the developing sleeve and the second developer stirring member is further away from the developing sleeve. The first developer stirring member and the second developer stirring member are provided between the first developer stirring member and the second developer stirring member. In a developing unit in which a partition member having a shape for ensuring a communication passage for the developer is provided at both ends and the developer circulates in a loop, a magnet is provided inside at a position along the second developer stirring member. A developing unit for arranging a developing sleeve for activating a developer and a doctor blade for activating a developer.
立上げ用ドクターブレードを、第２の現像剤攪拌部材か
ら第１の現像剤攪拌部材へ現像剤を受け渡す側に配置し
たことを特徴とする請求項１記載の現像ユニット。2. The developer startup developing sleeve and the developer startup doctor blade are arranged on the side for transferring the developer from the second developer stirring member to the first developer stirring member. The developing unit according to claim 1, which is characterized in that:
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP22781995A JP3455337B2 (en) | 1995-09-05 | 1995-09-05 | Developing unit |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP22781995A JP3455337B2 (en) | 1995-09-05 | 1995-09-05 | Developing unit |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH0973218A JPH0973218A (en) | 1997-03-18 |
| JP3455337B2 true JP3455337B2 (en) | 2003-10-14 |
Family
ID=16866879
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP22781995A Expired - Fee Related JP3455337B2 (en) | 1995-09-05 | 1995-09-05 | Developing unit |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP3455337B2 (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP4903551B2 (en) * | 2006-12-26 | 2012-03-28 | 三星電子株式会社 | Image forming apparatus |
-
1995
- 1995-09-05 JP JP22781995A patent/JP3455337B2/en not_active Expired - Fee Related
Also Published As
| Publication number | Publication date |
|---|---|
| JPH0973218A (en) | 1997-03-18 |
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