JP2003323043A - Developing device and image forming apparatus - Google Patents

Developing device and image forming apparatus

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Publication number
JP2003323043A
JP2003323043A JP2002127479A JP2002127479A JP2003323043A JP 2003323043 A JP2003323043 A JP 2003323043A JP 2002127479 A JP2002127479 A JP 2002127479A JP 2002127479 A JP2002127479 A JP 2002127479A JP 2003323043 A JP2003323043 A JP 2003323043A
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developer
developing
chamber
carrying member
image
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JP2002127479A
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JP3950735B2 (en )
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Fumitake Hirobe
文武 廣部
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Canon Inc
キヤノン株式会社
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Abstract

<P>PROBLEM TO BE SOLVED: To provide a developing device capable of forming a uniform image free from an image defect such as density irregularity by preventing developer from getting one-sided in a developing container and the developer from being deteriorated because it is concentrated in the vicinity of a developer regulation means as a developing device in which a circulation means for stirring and feeding the developer in the developing device and making it circulate is arranged up and down in a vertical direction in an image forming apparatus such as a high-speed copying machine or a printer, and to provide the image forming apparatus equipped with the developing device. <P>SOLUTION: In the developing device, a 2nd developer carrier 11 on which the developer T is carried to be fed to the 2nd developing part of an image carrier 10 and which can rotate in the same direction as a 1st developer carrier 8 is disposed above the developer carrier 8, and the developer T is transferred from the developer carrier 8 to the developer carrier 11. The developing container 2 has a developing chamber 3 supplying the developer T to the developer carrier 8, a stirring chamber 4 disposed above the chamber 3 and recovering the developer T passing through a 1st developing part and the 2nd developing part from the developer carrier 11, and circulation means 5 and 6 making the developer circulate between the chambers 3 and 4. <P>COPYRIGHT: (C)2004,JPO

Description

【発明の詳細な説明】 【0001】 【発明の属する技術分野】本発明は、像担持体上に形成された潜像に現像剤を付着させて可視像化する電子写真方式や静電記録方式を用いた複写機及びレーザービームプリンタなどの画像形成装置に使用される現像装置に関するものである。 BACKGROUND OF THE INVENTION [0001] [Technical Field of the Invention The present invention provides an electrophotographic method or an electrostatic recording a visible image by adhering developer to the latent image formed on an image bearing member scheme relates developing device used in an image forming apparatus such as a copying machine and laser beam printer was used. 【0002】 【従来の技術】電子写真方式を用いた複写機等の画像形成装置では、感光ドラム等の像担持体上に形成された潜像を、現像剤を付着させて可視像化する。 [0002] In the image forming apparatus such as a copying machine using the Related Art electrophotographic method, a latent image formed on an image bearing member such as a photosensitive drum, a visible image by attaching developer . このような現像に使用される従来の現像装置のうち、現像剤として、 Among conventional developing device used in such a developing, as a developer,
トナーとキャリアを含む二成分現像剤を用いるものの一例を図7に示す。 An example of those using two-component developer containing toner and carrier shown in FIG. この図7のように二成分現像剤を用いる現像装置102においては、二成分現像剤を攪拌しながら循環させる循環手段である第1の搬送スクリュー5 In the developing device 102 using a two-component developer as in FIG. 7, the first conveying screw is a circulating means for circulating while stirring the two-component developer 5
と第2の搬送スクリュー6とを水平方向に2本配置しているものが多い。 When many of the second conveying screw 6 are arranged two in the horizontal direction. 【0003】2本の循環手段のうち感光ドラムに近い方に位置する第1の搬送スクリュー5は、現像剤担持体(現像スリーブ)8に現像剤を供給し、現像部を通過した後の現像剤を回収するために用いられる。 [0003] The first conveyance screw 5 which is located closer to the photosensitive drum of the two circulating means, the developer carrying member to supply the developer to the development sleeve 8, developer after passing the developing unit agents used to recover. 又、第2の搬送スクリュー6は、現像スリーブ8から回収された現像剤と新しく補給された現像剤とを混合攪拌するために用いられる。 The second conveying screw 6 is used for mixing and stirring the recovered developer and newly replenished developer from the developing sleeve 8. 【0004】一方、近年、複写機、プリンタ等の電子写真方式を用いた画像形成装置においては、省スペースを達成するために装置本体の小型化の要求が強くなっており、特に、フルカラー方式の画像形成装置においては、 On the other hand, in recent years, copying machines, an image forming apparatus using the electrophotographic printer, etc., demand for downsizing of the apparatus main body in order to achieve a space-saving has become stronger, in particular, full color scheme in the image forming apparatus,
現像装置を複数用いるため、小型化の要望が強い。 For using a plurality of developing devices, demand for downsizing is strong. 【0005】この問題を解決するため、図8に示すような、特開平5−333691公報等に提案されている現像装置が考案されている。 To solve this problem, as shown in FIG. 8, the developing apparatus has been proposed which is proposed in JP-A-5-333691 Publication. この図8の現像装置103 A developing device 103 of FIG. 8
は、現像剤を攪拌・搬送し、現像容器2内を循環させる循環手段である2本の搬送スクリュー5、6が上下に配置されていることが特徴である。 Is a developer stirring and conveying, is characterized in that two conveying screws 5,6 a developer container 2 is a circulating means for circulating are arranged vertically. より詳細に説明すれば、現像装置103は現像剤を収容した現像容器2を備え、現像容器2の感光ドラム10と対面した開口部に現像剤担持体である現像スリーブ8を有している。 In more detail, the developing device 103 has a developing sleeve 8 which is a developer carrying member in the opening with a developer container 2 containing a developer, faces the photosensitive drum 10 of the developing container 2. そして、現像容器2内の開口部との反対側には隔壁7によって区画された現像室3と攪拌室4が上下に形成されており、これらの現像室3と攪拌室4内には、循環手段である第1及び第2の搬送スクリュー5、6がそれぞれ設置されている。 Then, on the opposite side of the opening in the developer container 2 and the developing chamber 3 and the stirring chamber 4 are partitioned by a partition wall 7 is formed on the upper and lower, these developing chamber 3 and the stirring chamber 4, circulation first and second conveying screws 5,6 a means is provided respectively. 第1の搬送スクリュー5は現像室3内の現像剤を搬送し、又、第2の搬送スクリュー6はトナー補給口(不図示)から攪拌室4内に第2の搬送スクリュー5の上流側に供給されるトナーと攪拌室4内に既にある現像剤とを攪拌しながら搬送し、現像剤のトナー濃度を均一化する。 The first conveying screw 5 conveys the developer in the developing chamber 3, and the second conveying screw 6 on the upstream side of the second conveying screw 5 to the stirring chamber 4 from the toner replenishing port (not shown) and already developer toner and the agitating chamber 4 supplied is conveyed while stirring, to equalize the toner density of the developer. 【0006】以上説明したように、図8に示した縦攪拌型の現像装置103は、現像室3と攪拌室4とが鉛直方向上下に配置されているため、その水平方向の占有スペースが小さくて済むという長所があり、例えば複数の現像装置を水平方向に並列搭載するタンデム方式等のカラー画像形成装置でも小型化が可能となる。 [0006] As described above, the vertical agitation type developing device 103 shown in FIG. 8, since the developing chamber 3 and the stirring chamber 4 are arranged in a vertical direction up and down, the space occupied by the horizontal direction is small has advantages of requiring Te, for example, miniaturization becomes possible with a color image forming apparatus such as a tandem type in parallel with a plurality of developing devices in the horizontal direction. 【0007】更に、この縦攪拌型の現像装置103は以下の利点も有している。 Furthermore, the developing device 103 of the vertical agitation type also has the following advantages. 【0008】即ち、現像室3から矢印aに従って供給された現像剤は、現像スリーブ8内に非回転に設けられた磁界発生手段であるマグネットローラ8'の現像容器2 [0008] That is, the developing agent supplied according to arrow a from the developing chamber 3, the developer container 2 of a magnetic field generating means provided in the non-rotating in the developing sleeve 8 a magnet roller 8 '
内部に位置する磁極N1により現像スリーブ8に汲み上げられ、現像スリーブ8の回転にともない、現像スリーブ8上を、磁極S1を通過し、現像スリーブ8が感光ドラム10側に露出している部分の磁極N2へと、現像容器2の内部から外部に搬送され、現像極S2が配置された、現像スリーブ8と感光ドラム10とが対向した現像部に至る。 Drawn up to the developing sleeve 8 by the magnetic pole N1 positioned inside, with the rotation of the developing sleeve 8, the upper developing sleeve 8, passes through the magnetic pole S1, poles of the portion developing sleeve 8 is exposed to the photosensitive drum 10 side to N2, is conveyed from the interior of the developing container 2 to the outside, the developing pole S2 arranged, the developing sleeve 8 and the photosensitive drum 10 reaches the developing portion opposed. その搬送途中で現像剤は、現像剤規制手段である現像剤規制ブレード9によりそれと対向する位置にある磁極S1と協同して磁気的に層厚を規制することで、現像剤の薄層化が達成し、現像部において静電潜像を現像する。 Developer in the course that the transport, by regulating the magnetically layer thickness in cooperation with the magnetic pole S1, which is positioned to the same facing the developer regulating blade 9 which is a developer regulating means, a thin layer of the developer is achieved, for developing an electrostatic latent image in the developing unit. 【0009】その後、現像部において現像に供されないで残った現像剤は、磁極N3で現像容器2内部に搬送され、現像容器2内部側に位置する隣り合った同極の磁極N1、N3の反発磁界により現像スリーブ8から除去され、現像容器2内下部分の攪拌室4に回収される。 [0009] Thereafter, the developer remaining without being used for development at the developing portion is conveyed inside the developer container 2 by the magnetic poles N3, repulsion of the developer container 2 magnetic poles of the same polarity of adjacent positioned inside side N1, N3 is removed from the developing sleeve 8 by the magnetic field, it is collected into the stirring chamber 4 of the developer container 2 inside lower portion. 【0010】このとき、現像スリーブ8の回転に伴って、横攪拌型の現像装置102のように現像室3側に回収されるのではなく、矢印bに従って攪拌室4側に回収されるために現像室3内には常に攪拌室4で十分攪拌された現像剤のみが存在する。 [0010] At this time, with the rotation of the developing sleeve 8, a developing chamber rather than being recovered in 3 side as the horizontal agitation type developing device 102, in order to be collected in the stirring chamber 4 side according to arrow b only always developer is sufficiently stirred in the stirring chamber 4 is present in the developing chamber 3. このため、現像スリーブ8 For this reason, the developing sleeve 8
には常に均一な濃度の現像剤が供給され、スラスト方向の画像ムラや濃度差のない均一な画像を得ることができる。 Always uniform density of the developer is supplied, it is possible to obtain a uniform image free from image unevenness and density difference of the thrust direction. 【0011】 【発明が解決しようとする課題】しかしながら、上記した従来の縦攪拌型現像装置の構成では以下のような問題が存在する。 [0011] However [0005] In the configuration of a conventional vertical agitation type developing apparatus described above there is the following problem. 【0012】従来の縦攪拌型現像装置103における剤循環経路は図8に示した通り、攪拌室4から現像室3へ受け渡された現像剤のすべてが現像室3において第1の搬送スクリュー5の下流端に到達するわけではなく、途中で現像スリーブ8に供給され、現像部を通過後、攪拌室4に回収される成分が存在する。 [0012] Conventional dosage circulation path in the vertical agitation type developing device 103 as is shown in FIG. 8, the first conveyance screw all the passed developer to the developing chamber 3 is in the developing chamber 3 from the agitating chamber 4 5 does not mean to reach the downstream end of the supplied to the developing sleeve 8 in the middle, after passing through the developing unit, the component to be recovered in the stirring chamber 4 are present. 【0013】この現像スリーブ8への現像剤Tの受け渡しは、現像スリーブ8のスラスト方向のほぼ全域にわたってなされる。 [0013] Passing of the developer T to the developing sleeve 8 is made substantially over the entire area of ​​the thrust direction of the developing sleeve 8. このため、現像室3内において第1の搬送スクリュー5により搬送される現像剤Tの量は、搬送方向上流端から下流端に行くに従い徐々に減少する傾向がある。 Therefore, the amount of the developer T is conveyed by the first conveying screw 5 in the developing chamber 3 tend to gradually decrease as it goes to the downstream end of the conveyance direction upstream end. 一方、攪拌室4において第2の搬送スクリュー6により搬送される現像剤Tの量は、搬送方向上流端から下流端にいくに従い徐々に増加する傾向がある。 On the other hand, the amount of the developer T in the stirring chamber 4 is conveyed by the second conveying screw 6 tends to increase gradually as it goes to the downstream end of the conveyance direction upstream end. 即ち、現像装置103内の現像剤Tの分布は図9に図示したように片寄りが非常に起こりやすい。 That is, the distribution of the developer T in the developing device 103 offset is likely to occur in very As illustrated in FIG. 【0014】又、本現像装置103では、現像室3が重力方向上方に、攪拌室4が重力方向下方に配置されているため、図9に示す方向dに移動し、つまり、現像室3 [0014] Further, in the developing device 103, the developing chamber 3 of gravity upward, since the stirring chamber 4 are arranged downward in the gravity direction, to move in a direction d shown in FIG. 9, that is, the developing chamber 3
から攪拌室4への現像剤Tは、現像容器2端部で攪拌室4内の攪拌スクリュー6現像剤搬送方向上流部にある隔壁7の開口部つまり現像室3から攪拌室4への連通部7 Developer T to the stirring chamber 4 are communicating portion from the opening, that the developing chamber 3 of the partition wall 7 in the agitating screw 6 developer conveying direction upstream portion of the agitating chamber 4 in the developer container 2 ends to the stirring chamber 4 7
2で、重力により落下し、又、攪拌室4から現像室3への現像剤は、現像容器2端部で連通部72の反対側に位置する連通部71にて下から上へ動く。 2, it falls by gravity, also the developer from the stirring chamber 4 to the developing chamber 3 moves from bottom to top in the communicating portion 71 located on the opposite side of the communicating portion 72 in the developer container 2 ends. 【0015】特に、この攪拌室4から現像室3への移動は、攪拌スクリュー6現像剤搬送方向下流部の連通部7 [0015] In particular, the move to the developing chamber 3 from the stirring chamber 4, the communicating portion 7 of the stirring screw 6 developer conveyance direction downstream portion
1で攪拌室4の端部に溜まった現像剤の圧力により下から上へと押し上げられるようにして現像剤Tが受け渡される。 1 developer T is transferred as pushed up from the bottom to the top by the pressure of the accumulated developer at an end portion of the agitating chamber 4. 【0016】このため、攪拌スクリュー6現像剤搬送方向下流部である連通部71では、現像剤Tに大きな圧力がかかり、現像剤T中の磁性キャリアとトナーが加圧されて、トナーに外添した酸化チタン等の微粒子がトナー中に埋め込まれると言った現象を生じる。 [0016] Thus, the communicating portion 71 is a stirring screw 6 developer conveying direction downstream section, it takes a large pressure on the developer T, the magnetic carrier and the toner in the developer T is pressurized, externally added to the toner fine particles such as titanium oxide results in a phenomenon said to be embedded in the toner. 更に、トナーと磁性キャリアとの摩擦によって、トナー自体の粒子形状も角がとれて丸みを帯びてくる。 Furthermore, by the friction between the toner and the magnetic carrier, the particle shape of the toner itself Tore corners coming rounded. 又、長時間使用すると、磁性キャリアの表面にトナーが付着して取れなくなる、いわゆるスペント現象が生じる。 Moreover, a long time when used, will not get to adhere toner to the surface of the magnetic carrier, so-called spent phenomenon. 【0017】又、図8の現像装置103では上述したように、現像剤規制ブレード9を用いて現像剤層厚規制を達成している。 [0017] Also, as described above in the developing device 103 of FIG. 8, it has achieved a developer layer thickness regulation with a developer regulating blade 9. この現像剤規制ブレード9近傍では規制ブレード9で現像スリーブ8から排除され余った現像剤は、該ブレード9のS1極とN1極の2極により発生する磁力により、現像剤規制ブレード9の現像スリーブ8 Developer remaining excluded from the developing sleeve 8 by the regulating blade 9 in the developer regulating blade 9 near by the magnetic force generated by the two-pole S1 pole and N1 pole of the blade 9, the developing sleeve of the developer regulating blade 9 8
の回転方向上流側付近に保持され大量に溜まり、現像剤規制ブレード9付近に溜った現像剤に対して現像スリーブ8によって次々に現像剤が搬送されてくるため、この現像剤規制ブレード9付近に溜った現像剤に大きな圧力がかかり、現像剤劣化を促進する。 Rotational direction upstream held near side reservoir to a large amount of, for developer one after another by the developing sleeve 8 to the developer collected in the vicinity of the developer regulating blade 9 is conveyed in the vicinity of the developer regulating blade 9 large pressure to the developer accumulated consuming, promotes deterioration of the developer. 【0018】このような現像剤劣化が生じると、トナーの摩擦帯電量(いわゆるトリボ)が使用時間とともに変化し、トナーの現像性が変わって画像濃度が変化したり、磁性キャリアや感光ドラムに対するトナーの機械的付着力が増大し、電界に対応した現像や転写が行われにくくなって、トナーの部分的欠落(ムラ)が発生してしまい、使用とともに、初期の画像と比べると、極めて印象の悪い画像になってしまうという問題が生じていた。 [0018] The toner for the such a developer deterioration occur, the triboelectric charge quantity of toner changed (so-called triboelectric charge) together with the operating time, the image density may change in developability of the toner is changed, the magnetic carrier and the photosensitive drum mechanical adhesion force is increased, making it difficult conducted development and transfer corresponding to the electric field, partial lack toner (unevenness) will occur, with use, as compared to the initial image, the strikingly a problem that became a bad image has occurred. 【0019】又、この現像剤劣化現象は、特に高速の複写機やプリンタに対応するために画像形成速度を増加させた場合に顕著になる。 [0019] Further, the developer deterioration phenomenon becomes remarkable when particularly increased image forming speed to high-speed copiers and printers. これは画像形成速度の増加に伴い、現像性を確保する為に現像スリーブ周速度を増加させる。 This involves an increase in image forming speed, increasing the developing sleeve peripheral speed to ensure developing property. それによる現像剤規制ブレード9付近での現像剤劣化及び現像剤搬送力を増加させることによる連通部7 Communicating unit 7 by increasing the developer deterioration and the developer conveying force around the developer regulating blade 9 by it
1での現像剤劣化が加速される。 Developer deterioration in 1 is accelerated. 【0020】我々の検討結果から劣化スピード(ここでは空回転での現像スリーブ上のトナートリボ変化を劣化スピードとして評価した)は速度の2乗で促進するため、現像スリーブ周速度を2倍、搬送スクリュー速度を2倍にすることで劣化は単純に16倍になると想定される。 [0020] To facilitate our study results from degradation speed (here were evaluated toner tribo variation on the developing sleeve of the air rotates degradation speed) is the square of the speed, twice the developing sleeve peripheral speed, conveying screws degradation by the speed doubling is assumed to simply become 16 times. そのため、上記のような問題は、最近の電子写真方式を用いたプリンタや複写機の更なる高速化の流れの中でますます重要な問題となると考えられる。 Therefore, the above problem is considered to be an increasingly important issue in recent further faster electrophotographic printer or a copying machine using a flow. 【0021】具体的には、現像スリーブの回転速度が2 [0021] Specifically, the rotational speed of the developing sleeve 2
50mm/secを超えると、更には500mm/se If more than 50mm / sec, and further 500mm / se
cを超えた高速対応現像装置で特に問題となっている。 In particular a problem in high speed corresponding developing device beyond or c. 【0022】従って、本発明の目的は、高速の複写機やプリンタのような画像形成装置にて、現像装置内の現像剤を攪拌・搬送し、循環させる循環手段が鉛直方向上下に配置された現像装置において、現像容器内での現像剤の片寄りや現像剤規制手段付近への集中によって生じる現像剤劣化を防止し、濃度ムラ等の画像不良の発生のない均一な画像を形成する現像装置及びそれを備えた画像形成装置を提供することである。 [0022] Therefore, an object of the present invention, in the image forming apparatus such as a high-speed copying machine or a printer, a developer in the developing device and stirring and conveying, circulation means for circulating are disposed vertically up and down the developing device, the developer deterioration preventing caused by concentration on the offset and the developer regulating means around the developer in the developing container, to form a uniform image free from occurrence of image defects such as density unevenness developing device and to provide an image forming apparatus having the same. 【0023】 【課題を解決するための手段】上記目的は本発明に係る現像装置及び画像形成装置にて達成される。 [0023] SUMMARY OF THE INVENTION The above object is achieved by the developing device and an image forming apparatus according to the present invention. 要約すれば、第1の本発明は、現像剤を収容する現像容器と、現像剤を担持してこれを像担持体の第1現像部に搬送する回転可能な第1の現像剤担持体と、を有し、前記像担持体上に形成された潜像を現像する現像装置において、前記第1の現像剤担持体の上方に、現像剤を担持してこれを前記像担持体の第2現像部に搬送する、前記第1の現像剤担持体と同方向に回転可能な第2の現像担持体が配設され、前記第1の現像担持体から前記第2の現像担持体へ現像剤が受け渡され、前記現像容器は、前記第1の現像担持体へ現像剤を供給する現像室と、該現像室の上方に配設され、前記第1現像部及び前記第2現像部を通過した現像剤を前記第2の現像担持体から回収する攪拌室と、前記現像室と前記攪拌室間で前記現像剤を循環させる循環 In summary, the first aspect of the present invention includes a developing container for accommodating the developer, a rotatable first developer carrying member for conveying this by carrying a developer to a first developing unit of the image bearing member has, in a developing device for developing a latent image formed on the image bearing member, above the first developer carrying member, the second of which carries a developer said image bearing member conveyed to the developing portion, the first second developer carrying member rotatable developer carrying member in the same direction are disposed, the developer from the first developer carrying member to said second developer carrying member is is passed, the developer container is passed through a developing chamber for supplying a developer, is disposed above the developing chamber, the first developing portion and the second developing unit the the first developer carrying member a stirring chamber for collecting the the developer from said second developer carrying member, circulation for circulating the developer between the stirring chamber and the developing chamber 段と、を有することを特徴とする現像装置を提供する。 To provide a developing apparatus, comprising: the stage, a. 【0024】第2の本発明は、表面に潜像が形成される像担持体と、第1の本発明の現像装置と、が備えられ、 The second of the present invention includes an image bearing member a latent image is formed on the surface, a developing device of the first present invention, is provided,
記録材に画像を形成することを特徴とする画像形成装置を提供する。 To provide an image forming apparatus and forming an image on a recording material. 【0025】 【発明の実施の形態】以下、本発明に係る現像装置及び画像形成装置を図面に則して更に詳しく説明する。 [0025] PREFERRED EMBODIMENTS Hereinafter will be described in more detail with reference to the accompanying drawings developing device and an image forming apparatus according to the present invention. 尚、 still,
この現像装置は、例えば以下に述べるような画像形成装置の中で使用されるが、必ずしもこの形態に限られるものではない。 The developing device, for example, are used in the image forming apparatus as described below, not necessarily limited to this form. 【0026】実施例1 図1は、図2に示されるようなフルカラー画像形成装置における、Y、M、C、Kの各ステーションにおける像担持体(感光ドラム)10と現像装置1との位置関係を示したものである。 [0026] Example 1 FIG. 1 is in the full-color image forming apparatus as shown in FIG. 2, Y, M, C, the image bearing member at each station K (photosensitive drum) 10 and the positional relationship between the developing device 1 It shows the. Y、M、C、Kの各ステーションはほぼ同様の構成であり、フルカラー画像において、それぞれイエロー(Y)、マゼンタ(M)、シアン(C)、 Y, M, C, each station K is substantially the same structure, in a full-color image, each of yellow (Y), magenta (M), cyan (C),
ブラック(K)の画像を形成する。 Forming an image of black (K). 以下の説明において、例えば現像装置1とあれば、Y、M、C、K各ステーションにおける現像装置1Y、現像装置1M、現像装置1C、現像装置1Kを共通して指すものとする。 In the following description, for example, if the developing device 1, for Y, M, C, K developing devices 1Y in each station, a developing device 1M, a developing device 1C, shall refer to a common developing device 1K. 【0027】まず、図2により、画像形成装置全体の動作を説明する。 [0027] First, FIG. 2, the operation of the entire image forming apparatus. 【0028】像担持体である感光ドラム10は回動自在に設けられており、その感光ドラム10を一次帯電器2 The image bearing member is a photosensitive drum 10 is rotatably provided, the photosensitive drum 10 primary charger 2
1で一様に帯電し、例えばレーザーのような発光素子2 Uniformly charged at 1, for example, the light emitting element 2 such as a laser
2によって情報信号に応じて変調された光で露光して潜像を形成する。 By 2 is exposed with light modulated according to information signals to form a latent image. その潜像は現像装置1により、後述のような過程でトナー像として可視像化される。 By its latent image developing device 1, it is visualized as a toner image in the process as described below. その可視像である現像像(トナー像)を、第1転写帯電器23によって、転写媒体シート24上に各ステーションごとに転写し、その後、搬送されてきた記録材である転写紙27 Developed image that is a visible image (toner image), by the first transfer charger 23, the transfer medium sheet is transferred to each station on the 24, then, the transfer paper 27 as a recording material conveyed
上に第2転写帯電器30によって転写し、更に定着装置25によって定着して永久画像を得る。 Transferring the second transfer charger 30 above, to obtain a permanent image by the fixing by further fixing device 25. 又、感光ドラム10上の転写残トナーはクリーニング装置26により除去する。 Also, the transfer residual toner on the photosensitive drum 10 is removed by a cleaning device 26. 又、画像形成で消費されたトナーはトナー補給槽20から補給される。 The toner consumed in the image formation is supplied from a toner supply tank 20. 【0029】又、ここでは、トナー像を感光ドラム10 [0029] Further, here, the photosensitive toner image drum 10
M、10C、10Y、10Kから中間転写体としての転写媒体シート24に一次転写した後に、記録材である転写紙に各色の複合トナー像を一括して二次転写する構成をとったが、転写媒体シート24の代わりに、各ステーションM、C、Y、Kに対向しながら記録材を搬送する転写材搬送体を設け、転写材搬送体に搬送される転写紙に直接転写する構成とる画像形成装置においても、本発明は適用できる。 M, 10C, 10Y, after the primary-transferred transfer media sheet 24 as an intermediate transfer member from the 10K, but it took configured to secondarily transferred collectively colors composite toner image onto a transfer sheet as a recording medium, transfer instead of media sheet 24, each station M, C, Y, K the transfer material conveying member for conveying the face while the recording material is provided in the image forming taking configured directly transferred to a transfer paper conveyed to the transfer material conveying member also in apparatus, the present invention is applicable. 【0030】次に、図1により、現像装置1の動作を説明する。 Next, with reference to FIG. 1, operation of the developing device 1. 本実施例の現像装置1は、非磁性トナーと磁性キャリアを含む二成分現像剤が収容された現像容器2内に、現像剤担持体としての第1現像スリーブ8と、現像スリーブ8と対向して設置され、現像スリーブ8表面に担持された現像剤の層厚を規制する現像剤規制手段である規制ブレード9と、を有している。 Developing apparatus 1 of this embodiment, the developing container 2 which two-component developer containing nonmagnetic toner and magnetic carrier is accommodated, the first developing sleeve 8 as the developer carrying member, opposed to the developing sleeve 8 installed Te, and a regulating blade 9 which is a developer regulating means for regulating the layer thickness of the developer carried on the developing sleeve 8 surface. 規制ブレード9は現像スリーブ8の下方に位置している。 Regulating blade 9 is positioned below the developing sleeve 8. 【0031】そして、第1現像スリーブ8の上方にてそれと対向するように第2現像スリーブ11が配設され、 [0031] Then, the second developing sleeve 11 is disposed so as to therewith opposed at above the first developing sleeve 8,
現像容器2内の略中央部に現像スリーブ8と平行に延在する隔壁7によって現像室3とその上方の攪拌室4とにより上下に区画されており、現像剤は現像室3及び攪拌室4に収容されている。 By a partition wall 7 extending parallel to the developing sleeve 8 in the substantially central portion of the developing container 2 is partitioned vertically by a developing chamber 3 and the stirring chamber 4 located thereabove, the developer developing chamber 3 and the stirring chamber 4 It is housed in. 【0032】更に、上記現像容器2の感光ドラム10に対向した現像部に相当する位置には開口部があり、この開口部に第1現像スリーブ8及び第2現像スリーブ11 Furthermore, at a position corresponding to the developing section opposite to the photosensitive drum 10 of the developing container 2 has an opening, the first developing sleeve 8 and the second developing sleeve 11 in the opening
が感光ドラム10側に一部露出するように回転可能に配設されている。 There is rotatably disposed so as to expose a portion on the photosensitive drum 10 side. 尚、この第1、第2現像スリーブ8、1 In this first, the second developing sleeve 8,1
1は非磁性材料で構成され、その内部には第1、第2の磁界発生手段であるマグネットローラ8'、11'が非回転状態で設置されており、この第1現像スリーブ8内の第1マグネットローラ8'は、現像極N2と現像剤T 1 is composed of non-magnetic material, first inside thereof, the magnet roller 8 which is a second magnetic field generating means ', 11' are installed in a non-rotating state, the in this first developing sleeve 8 1 magnet roller 8 'includes a developing pole N2 developer T
を搬送する磁極S1、S2、N1、N3、を有し、第2 Conveying the magnetic pole S1, S2, N1, N3, having a second
現像スリーブ11内の第2マグネットローラ11'は、 Second magnet roller 11 in the developing sleeve 11 '
現像極N4と現像剤を搬送する磁極S3、S4極を有している。 And a magnetic pole S3, S4 pole for transporting the developing pole N4 developer. このうち、N1極とN3極、及びS3極とS4 Among, N1 pole and the N3 pole, and S3 pole and S4
極は、詳しくは後に説明するように、同極で極間には反発磁界が形成され、現像剤に対してはバリアが形成されている。 Poles, details as described later, the machining gap at the same polarity repulsive magnetic field is formed, a barrier is formed against the developer. 【0033】そして本実施例では、現像スリーブ8、1 [0033] Then, in this embodiment, the developing sleeve 8,1
1は、同方向である図示矢印方向に回転することで、感光ドラム10に対して順方向に回転し、現像部を重力方向下から上へと通過する方向に回転する構成とした。 1, by rotating in the direction shown by an arrow in the same direction, rotating in a forward direction with respect to the photosensitive drum 10 and the developing unit is configured to be rotated in a direction to pass up from the lower direction of gravity. つまり、現像容器2の隔壁7によって仕切られた下部分の現像室3から現像剤Tが汲み上げられ、現像後の現像剤Tが上部分の攪拌室4に戻るように搬送される。 In other words, the developer T is drawn up from the developing chamber 3 of the lower part partitioned by a partition wall 7 of the developing container 2, the developer T after development is conveyed back to the stirring chamber 4 of the upper part. 【0034】これらの現像スリーブ8、11による感光ドラム10への現像剤Tの搬送について説明する。 The described conveyance of the developer T to the photosensitive drum 10 by these developing sleeves 8 and 11. まず現像室3内の第1搬送スクリュー5により搬送された二成分現像剤Tは、第1現像スリーブ8の現像容器内部側に位置するN1極の磁力により汲み上げられ、現像スリーブ8回転方向に従って搬送され、規制ブレード9によりそれと対向する位置にある磁極S2と協同して磁気的に層厚を規制され、これを感光ドラム10と対向した第1現像部(現像磁極N2)に搬送し、感光ドラム10上に形成された潜像に現像剤Tを供給して潜像を現像する。 First the two-component developer T transported by the first transport screw 5 in the developing chamber 3 is pumped up by the N1 pole of the magnetic force located developer container interior side of the first developing sleeve 8, the conveyance in accordance with the developing sleeve 8 rotating direction It is, is regulated magnetically layer thickness in cooperation with the magnetic pole S2, which is positioned to the same opposing the regulating blade 9, conveys it to the first developing portion opposed to the photosensitive drum 10 (developing magnetic pole N2), the photosensitive drum the latent image formed on 10 by supplying the developer T to develop the latent image. 【0035】そして第1現像スリーブ8による第1現像終了後、現像剤Tは、現像スリーブ8の回転方向に従って、重力方向下から上へとS1極を通過し、両スリーブ8と11が最も接近している現像スリーブ8内部のマグネット8'のN3極と、現像スリーブ11内部のマグネット11'のS3極と、の間において、第2現像スリーブ11に引き渡される。 [0035] Then after the first completion of development of the first developing sleeve 8, the developer T in accordance with the rotational direction of the developing sleeve 8, passes through the pole S1 to top from bottom direction of gravity, both the sleeve 8 and 11 closest 'and N3 pole of the developing sleeve 11 inside the magnet 11' the developing sleeve 8 of the magnet 8 that the S3 poles, between, are handed over to the second developing sleeve 11. 【0036】以下、現像剤Tの流れを、図3に示す、第1現像スリーブ8と第2現像スリーブ11付近の拡大図を用いて説明する。 [0036] Hereinafter, the flow of the developer T, shown in FIG. 3 will be described with reference to the first developing sleeve 8 an enlarged view of the vicinity of the second developing sleeve 11. 第1現像スリーブ8内部の第1マグネット8'の、第1磁極N1極とそれと同極性で現像スリーブ8回転方向の上流側の第2磁極N3極間には反発磁界が形成されおり、又、第2現像スリーブ11内部の第2マグネット11'の第3磁極S3極と第4磁極S4 Internal of the first magnet 8 'the first developing sleeve 8, repulsive magnetic field in the second magnetic pole N3 interpolar the upstream side of the first magnetic pole N1 pole and therewith the developing sleeve 8 rotating direction at the same polarity are formed, and, second developing sleeve 11 inside of the second magnet 11 third magnetic pole S3 poles and fourth magnetic poles S4 in '
極間にも反発磁界が形成されている。 Repulsive magnetic field in the machining gap is formed. 尚、現像スリーブ8内のN1極とN3極の反発磁界及び第2現像スリーブ11内のS3極とS4極の反発磁界は同じ側を向き、現像容器2の内部方向を向いている。 Incidentally, repulsive magnetic field at S3 pole and S4 pole N1 pole and the N3 pole of the repulsive magnetic field and the second developing sleeve 11 in the developing sleeve 8 faces the same side, facing the internal direction of the developing container 2. よって、第一現像スリーブ8上を搬送され第1現像スリーブ8の現像部である第1現像部を通過してきた現像剤Tは、その回転によって、マグネット8'の第2磁極N3極の位置へ至り、 Therefore, the developer T which has passed through the first developing unit is a developing unit of the first developing sleeve 8 is conveyed on the first developing sleeve 8, by its rotation, the position of the second magnetic pole N3 pole of the magnet 8 ' lead,
下流の第1磁極N1極との反発磁界によって、両スリーブ8と11の対向部である最近接位置をすり抜けて、矢印eのように通過することができず、即ち現像スリーブ8に現像剤Tが連れ回ることができず、矢印fのように第1現像スリーブ8側のN3極から第2現像スリーブ1 By the repulsive magnetic field between the first magnetic pole N1 pole downstream, slipping through the closest position which is opposed portions of the sleeve 8 and 11, it can not pass through as indicated by the arrow e, i.e. the developer T to the developing sleeve 8 can not be rotated together, the second developing sleeve from the first developing sleeve 8 side of the pole N3 as indicated by arrow f 1
1側のマグネット11'の第3磁極S3極方向へのびる磁力線に従って、第2現像スリーブ11側へ移動し、第2現像スリーブ11上を搬送されることでマグネット1 Accordance magnetic field lines extending to the third magnetic pole S3 pole direction of one side of the magnet 11 ', the magnet 1 by moving the second developing sleeve 11 side, is conveyed on the second developing sleeve 11
1'のN4極である第2現像部に達し、再度現像に供され、その後、攪拌室4内の第2の搬送スクリュー6まで搬送される。 Reaches the second developing unit is N4 pole 1 ', is used for the development again, then, it is conveyed to the second conveying screw 6 in the stirring chamber 4. 【0037】尚、現像効率(つまり、潜像へのトナーの付与率)を向上させるために、第1及び第2現像スリーブ8、11には電源から直流電圧と交流電圧を重畳した現像バイアス電圧が印加される。 [0037] Incidentally, the development efficiency (i.e., grant of the toner to the latent image) in order to improve the developing bias voltage to the first and second developing sleeve 8 and 11 obtained by superimposing a DC voltage and an AC voltage from a power source There is applied. この第2現像スリーブ11に印加する現像バイアスは直流電圧のみでもよいが、第1現像スリーブ8に印加する現像バイアスと同様に直流電圧と交流電圧を重畳した電圧を印加することでより現像効率を上げることが可能となる。 Developing bias applied to the second developing sleeve 11 may be only a DC voltage, but a more development efficiency by applying a voltage obtained by superimposing a DC voltage and an AC voltage as with the developing bias applied to the first developing sleeve 8 It can be increased to become. まとめると、 Summary,
第1現像スリーブ8か第2現像スリーブ11のいずれか、更に好ましくは両方に交流電圧を印加させることが好ましい。 One of the first developing sleeve 8 or the second developing sleeve 11, it is preferable to apply an AC voltage to more preferably both. 【0038】現像スリーブ8、11を2本用いることで現像回数が2回に増え、つまり、濃度低下に関しては、 The increase in development times twice by using the developing sleeve 8 and 11 two, that is, with respect to the concentration decreases,
2回目の現像を行うことで十分感光ドラム10の潜像部分にトナーを載せることが可能となり、1本スリーブから構成される従来系よりも現像効率を上げることが可能となる。 Can put the toner sufficiently latent image portion of the photosensitive drum 10 by performing a second development and becomes, it becomes possible to increase the developing efficiency than the conventional system composed of one sleeve. 具体的には我々の実験の結果では現像効率として約30%改善した。 Specifically the results of our experiments was improved by about 30% as a developing efficiency. これによりスリーブ周速度を逆に30%低下しても1本スリーブ同等の現像効率を達成できるようになった。 Thus now a single sleeve same development efficiency decreased by 30% sleeve peripheral speed in the opposite can be achieved. 従って、上述したように現像剤劣化を抑制する事が可能となった。 Therefore, it is possible to suppress deterioration of the developer as described above. 【0039】その後、現像スリーブ11の回転によって、攪拌室4内に搬送され、第2現像スリーブ11内で現像容器2内部側に設けられたS3極とS4極間での反発磁界により攪拌室4の搬送スクリュー6へと現像剤T [0039] Then, by the rotation of the developing sleeve 11 is transported to the stirring chamber 4, the stirring chamber 4 by the repulsive magnetic field in S3 pole and S4 machining gap provided in the developer container 2 inner side in the second developing sleeve 11 the developer T to the conveyance screw 6
が剥ぎ落とされる。 It is dropped stripped. 【0040】又、上述した通り、現像室3と攪拌室4には現像剤攪拌・搬送し、循環させる循環手段として第1 [0040] Also, as described above, the developer stirred and conveyed to the developing chamber 3 and the stirring chamber 4, first as a circulating means for circulating
及び第2の搬送スクリュー5、6がそれぞれ配置されている。 And second conveying screws 5 and 6 are disposed respectively. 第1の搬送スクリュー5は、現像室3内の底部に現像スリーブ8の軸方向(現像幅方向)に沿ってほぼ平行に配置されており、回転して現像室3内の現像剤Tを現像室3の底部にて現像スリーブ8の軸線方向に沿って搬送する。 The first conveying screw 5, developing on the bottom of the developing chamber 3 the axial direction of the developing sleeve 8 are arranged substantially parallel to the (development width direction), rotated to the developer T in the developing chamber 3 at the bottom of the chamber 3 is carried along the axial direction of the developing sleeve 8. 又、第2の搬送スクリュー6も第1の搬送スクリュー5とは逆向きにしてスパイラル状に設けたスクリュー構造とされ、攪拌室4内の底部に第1の搬送スクリュー5とほぼ平行に配設され、第1の搬送スクリュー5と同方向に回転して攪拌室4内の現像剤を第1の搬送スクリュー5と反対方向に搬送する。 Also, the second conveying screw 6 and the first conveying screw 5 is a screw structure in which a spiral shape in the opposite direction, substantially arranged parallel to the first conveying screw 5 on the bottom of the stirring chamber 4 It is, to convey the first conveying screw 5 and the developer in the stirring chamber 4 to rotate in the same direction in a direction opposite to the first conveying screw 5. 【0041】このようにして、第1及び第2の搬送スクリュー5、6の回転によって、図4に示すような、現像剤が隔壁7の両端の開口部71、72を通って、d方向に現像室3と攪拌室4との間で循環される。 [0041] Thus, the rotation of the first and second conveying screws 5,6, as shown in FIG. 4, the developer through the opening 71, 72 at both ends of the partition walls 7, in the direction d It is circulated between the developing chamber 3 and the stirring chamber 4. 【0042】特に本実施例において、攪拌室4と現像室3とが鉛直方向上下に配置されている点は従来例と同じであるが、現像室と攪拌室が上下逆に位置している点が従来例の現像装置103とは大きく異なっている。 [0042] In particular, the present embodiment, although the point where the stirring chamber 4 and the developing chamber 3 is arranged vertically above and below is the same as the conventional example, that the developing chamber and the stirring chamber is positioned upside down There are significantly different from the developing device 103 of the conventional example. つまり、攪拌室4から現像室3への現像剤は重力により上から下へ、又、現像室3から攪拌室4への現像剤は下から上へ剤圧により動く。 That is, the developer from the stirring chamber 4 to the developing chamber 3 from top to bottom by gravity, also the developer from the developing chamber 3 to the agitating chamber 4 is moved by agent pressure from bottom to top. 【0043】ここで、上述した通り現像剤劣化は、現像剤にかかる圧力が最大となる部分、つまり本実施例で、 [0043] Here, as developer deterioration described above, the portion where the pressure applied to the developer becomes maximum, i.e. in the present embodiment,
トナーが補給される攪拌室4内の搬送スクリュー6現像剤搬送方向の下流部分であり、最も剤面が高くなる連通部72で促進されるが、攪拌室4から現像室3への移動を下から上とした結果、本実施例では攪拌室4から現像室3への連通部72での剤循環は剤圧ではなく重力でおこなわれるため、剤へのストレスがない。 A downstream portion of the conveying screws 6 developer conveying direction of the stirring chamber 4 to which the toner is replenished, is accelerated by the communicating portion 72 for most developer surface becomes higher, the lower the transfer from the stirring chamber 4 to the developing chamber 3 as a result of the above from, to be done by gravity rather than agent circulation agent pressure at the communicating portion 72 from the stirring chamber 4 to the developing chamber 3 in this embodiment, there is no stress on the agent. 【0044】又、現像室3から攪拌室4への循環は剤圧により連通部71で下から上へと搬送されるが、現像剤剤面バランスは、図4に示したとおり現像室3側下流側では、現像剤Tが現像動作に供されるため、剤面が低くなり、剤圧で循環しないような剤量並びに現像剤搬送力に規制することができるので、ストレスのかかる部分が少ない(現像剤劣化の少ない)現像装置を達成することができた。 [0044] In addition, it is conveyed from bottom to top in the communication part 71 by circulating agent pressure from the developing chamber 3 to the stirring chamber 4, surface balance developer agent, as developing chamber 3 side shown in FIG. 4 downstream, since the developer T is subjected to a developing operation, the developer surface is lowered, such agent amount as not to circulate agent pressure and it is possible to regulate the developer conveying force, less parts stressful It could be achieved (developer less degradation) developing apparatus. 【0045】具体的に我々は、本実施例にて、2本スリーブを用いることでスリーブ周速を30%ダウンすることができ、更に、現像室3を重力方向下に、攪拌室4を重力方向上に配置したことで、現像剤にかかるストレスを解消した。 [0045] Specifically we have in this embodiment, the sleeve peripheral speed by using two sleeves can be down to 30%, further, the developing chamber 3 under gravity direction, gravitational agitation chamber 4 by disposing on direction and eliminate the stress on the developer. 【0046】本実施例の構成で実験したところ、従来現像装置を用いた際の現像剤劣化スピードに対し、1/3 [0046] When an experiment the configuration of the present embodiment, with respect to the developer deterioration speed when using the conventional developing device, 1/3
まで低減することが可能となった。 It has become possible to reduce up to. 【0047】一般に、現像剤劣化は、特に高速の複写機やプリンタに対応するために現像スリーブの周速度を早くした場合に、顕著に現われるようになる。 [0047] Generally, the deterioration of the developer, especially when fast peripheral speed of the developing sleeve in order to cope with high speed copying machine or a printer, becomes noticeably appears as. 具体的には、現像スリーブの回転速度が250mm/secを超えると、更には500mm/sec以上で特に問題になる。 Specifically, when the rotational speed of the developing sleeve exceeds 250 mm / sec, more particularly problematic with 500 mm / sec or more. 又、一般に、現像スリーブの回転を1000mm/ Also, in general, the rotation of the developing sleeve 1000 mm /
sec以上にすると現像スリーブからの遠心力によるトナーの飛散が問題になるので、本発明は、現像スリーブの周速を250mm/sec以上1000mm/sec Since scattering of toner due to the centrifugal force from the developing sleeve to the above sec is a problem, the present invention, the peripheral speed of the developing sleeve 250 mm / sec or more 1000 mm / sec
以下の高速対応現像装置に有効なものといえる。 It said to be effective in a high speed corresponding developing device below. 【0048】以上のように、現像装置内の現像剤を攪拌・搬送し、現像容器内を循環させる循環手段が上下に配置された場合において、2本の現像スリーブを用い、更に現像スリーブに現像剤を供する現像室を下に、現像に共された後の現像剤を回収する攪拌室を上方に配置させた現像容器を用いることで現像効率を改善でき、更に容易に現像剤劣化を防止できる現像装置を提供することができる。 [0048] As described above, the developer in the developing device and stirring and conveying, in a case where the circulating means for circulating the developer container is disposed vertically, using two developing sleeve, further development to the developing sleeve under the developing chamber to provide the agent, can improve development efficiency by using a developer container was placed a stir chamber upwardly for collecting the developer after being co-development, it can be prevented more easily developer deterioration it is possible to provide a developing device. 従って、現像剤劣化に伴う濃度ムラ等の画像不良を回避し、良好な画像形成を行う現像装置及びそれを備えた画像形成装置が提供できる。 Therefore, to avoid the image defect density unevenness due to deterioration of the developer, can provide a developing device and an image forming apparatus provided therewith perform good image formation. 【0049】実施例2 次に本発明の実施例2を図5の断面図に基づいて説明する。 [0049] be described with reference to Example 2 of the present invention will now Example 2 in the sectional view of FIG. 【0050】本実施例は実施例1とほぼ同様の構成であるが、本実施例の現像装置100においては、規制ブレード9を第1現像スリーブ内に設けられた第1と第2の磁極である反発極N1、N3のうち現像スリーブ8の回転方向で下流側の第1磁極であるN1極近傍に対向させ、汲み上げと同時に現像剤の層厚規制を行うことが特徴である。 [0050] While this embodiment is substantially the same structure as in Example 1, the developing device 100 of this embodiment, the first and second magnetic pole which is provided with the regulating blade 9 inside the first developing sleeve to face the N1 pole near a first magnetic pole downstream in the rotation direction of the developing sleeve 8 of some repulsive poles N1, N3, it is it is characterized to conduct the layer thickness regulation of pumping at the same time the developer. 【0051】この構成は、例えば特開平11−1946 [0051] This configuration is, for example, JP-A-11-1946
17公報等に提案されているように現像装置トルクを大幅に減少可能な構成であるが、1本の現像スリーブを用いる構成のものや水平方向に搬送部材を設置する構成では、現像剤溜り部となる領域が非常に少ないため、現像剤がスリーブ上を連れ回ることでの現像剤トナー濃度ムラ画像欠陥を生じやすかった。 17 is a greatly reduced configurable developing apparatus torque as proposed in Japanese, etc., but in the configuration of installing the one or horizontally conveying member configurations using a single developing sleeve, a developer reservoir section since very little area to be, the developer is likely to occur the developer toner density unevenness image defects by rotated together on sleeves. 【0052】しかしながら、本実施例のように縦攪拌型の現像装置と2本の現像スリーブ構成を用いることで現像剤の連れ回りを完全に防止できるため、先の画像欠陥が生じることがなくなった。 [0052] However, it is possible to prevent completely the co-rotation of the developer by using a vertical agitation type developing device and the developing sleeve arrangement of two as in this example, no longer be the previous image defects . この構成を用いて我々の実験したところ実施例1の現像装置1に比べ、現像剤劣化スピードを1/4まで低減できることが確かめられた。 Compared to the developing device 1 of Example 1 was our experiments with this arrangement, it was confirmed that can reduce the developer deterioration speed to 1/4. 【0053】以上のように、規制ブレードを第1現像スリーブ内に設けられた反発極のうち現像スリーブ回転方向で下流側の第1磁極近傍に対向させ、2本の現像スリーブを用いた本構成を採用することで大幅に現像剤劣化を防止できる現像装置を提供することができる。 [0053] As described above, are opposed to the regulating blade to the first magnetic pole near the downstream in the developing sleeve rotation direction of the repelling poles provided in the first developing sleeve, the configuration using the two developing sleeves it is possible to provide a developing device capable of preventing a by adopting greatly developer degrade. 【0054】実施例3 次に本発明の実施例3を図6に基づいて説明する。 [0054] Example 3 Example 3 of the present invention will be described below with reference to FIG. 尚、 still,
図6は、本実施例に係る現像装置101のスクリュー軸方向断面図である。 Figure 6 is a screw axial cross-sectional view of the developing device 101 according to this embodiment. 【0055】本実施例は実施例1の現像装置1とほぼ同様の構成であるが、本実施例においては、現像室3の容器最下流近傍の外壁に現像剤の剤面高さがある一定以上(図中ではg)になった場合に現像剤を排出するための排出口12を設けたことが特徴である。 [0055] Although the present embodiment is substantially the same structure as the developing apparatus 1 of the first embodiment, in this embodiment, there is a developer surface height of the developer on the outer wall of the container most downstream vicinity of the developing chamber 3 constant above is characterized in that provided an outlet 12 for discharging the developer if it becomes (g in the figure). 【0056】本構成により、現像室3内を搬送スクリュー5により搬送されてき現像剤Tが、第1現像スリーブ8上に汲みあがらず、現像室3最下流部の現像剤滞留部に蓄積し、現像剤面が上昇してきた場合にも、ある高さg以上になると、現像剤排出口12より自動的に排出されることになる。 [0056] With this configuration, the developer T has a developing chamber 3 is transferred by the transfer screw 5 is not increased pumping on the first developing sleeve 8, and accumulated in the developer staying portion of the developing chamber 3 downstream portion, when the developer surface have risen, becomes more than a certain height g, it will be automatically discharged from the developer discharge port 12. 尚、排出された現像剤Tは廃トナーボックス(不図示)へと搬送される。 Incidentally, the discharged developer T is conveyed to the waste toner box (not shown). 従って現像室3下流部の剤面を一定に保つことができるようになった。 Thus it has become possible to maintain the agent surface of the developing chamber 3 downstream portion constant. 【0057】この結果連通部71で現像室3から攪拌室4へ汲みあがる際の現像剤Tへのストレスを軽減することができ、更なる現像剤劣化スピードを低減する現像装置を提供することができる。 [0057] be the result communicating portion 71 can reduce the stress from the developing chamber 3 to the developer T at the time of rising pumping into the stirring chamber 4, provide a developing apparatus for reducing further developer deterioration speed it can. 【0058】実施例4 本実施例4では、トナー補給槽20内に補給トナーに加えて磁性キャリアを混合したことを特徴とする。 [0058] Example 4 Example 4, characterized in that a mixture of magnetic carrier in addition to the supplied toner in the toner replenishing tank 20. 【0059】この構成により、実施例3において現像剤排出口12より現像剤(トナー+磁性キャリア)が流出しても上記トナー補給槽20より補給することで、劣化していない新しい磁性キャリアを自動的に補給することが可能となった為、耐久を通してトリボを安定化できた。 [0059] Automatic This configuration a new magnetic carrier developer discharge port 12 of the developing agent (toner + magnetic carrier) is also flows out by replenishing from the toner replenishing tank 20, which is not deteriorated in Example 3 because it has become possible to supply to, it was able to stabilize the triboelectric charge through endurance. この結果、現像剤寿命を更に延命することが可能となった。 As a result, it became possible to further prolong the developer life. 【0060】以上に述べた本発明により、現像装置内の現像剤を攪拌・搬送し、循環させる循環手段が上下に配置された場合の構成において、2本の現像スリーブを用いた構成を採用することで現像効率を改善でき、更に容易に現像剤劣化を防止できる。 [0060] The present invention described above, the developer in the developing device and stirring and conveying, in the configuration when the circulating means for circulating are arranged vertically, to adopt a configuration using two developing sleeves can improve development efficiency by, it can be prevented more easily developer deterioration. 従って、現像剤劣化に伴う濃度ムラ等の画像不良も回避し、良好な画像形成が可能となる。 Therefore, image density unevenness, etc. due to developer deterioration failure also avoided, thereby enabling good image formation. 【0061】又、本発明の現像装置の特徴である、現像容器を現像室と攪拌室に分割する構成は、一般に二成分現像器に対して実行されているが、実施例1〜3に関しては、現像剤は、二成分現像剤に限定されるわけではなく、トナーを含んでキャリアを含まない一成分現像剤を用いても良い。 [0061] Also, a feature of the developing device of the present invention, is configured to divide the developer container to the developing chamber and the stirring chamber, generally are performed for the two-component developing device, but for Example 1-3 , the developer is not limited to the two-component developer, may be used one-component developer not containing carrier contains toner. 一成分現像剤の場合は、特に連れまわりによる剤劣化抑制を目的として本発明が適用できる。 For one-component developer, may present invention is applied for the purpose of surrounding the dosage suppressing deterioration took particular. 【0062】 【発明の効果】以上説明したように、本発明は、現像装置内の現像剤を攪拌・搬送し、循環させる循環手段が上下に配置された場合の構成において、2本の現像剤担持体を用い、現像容器は、第1の現像担持体へ現像剤を供給する現像室が重力方向下方に、第1現像部及び前記第2現像部を通過した現像剤を第2の現像担持体から回収する攪拌室を上方に、配置した構成を採用することで、 [0062] As described above, according to the present invention, in a configuration in which the developer in the developing device and stirring and conveying, circulation means for circulating disposed above and below, two developer with carrier, developing container, a developer developing chamber in the gravity direction lower side supplied to the first developing carrying member, the developer that has passed through the first developing portion and the second developing unit the second developer carrying the stirring chamber for collecting the body upward, by adopting an arrangement and configuration,
現像効率を改善し、現像容器内でかかる現像剤へのストレスを軽減することで、現像剤劣化を防止できる現像装置を提供することができるので、小型で、高速化対応可能で、現像剤劣化に伴う濃度ムラ等の画像不良を回避し、良好な画像を形成する現像装置及びそれを備えた画像形成装置が達成される。 The development efficiency was improved, to alleviate the stress on the developer according in the developing container, it is possible to provide a developing device capable of preventing deterioration of the developer, a small, high-speed response possible, developer deterioration to avoid image defects such as density unevenness caused by, a developing device and an image forming apparatus including the same can be achieved to form a good image.

【図面の簡単な説明】 【図1】本発明に係る現像装置の一例及び感光ドラムとの位置関係を示す断面図である。 Is a sectional view showing the positional relationship between an example and a photosensitive drum BRIEF DESCRIPTION OF THE DRAWINGS [Figure 1] developing device according to the present invention. 【図2】本発明に係る画像形成装置の一例を示す概略構成図である。 Is a schematic diagram showing an example of an image forming apparatus according to the present invention; FIG. 【図3】本発明に係る現像装置の一例における現像剤担持体部分を示す拡大図である。 3 is an enlarged view of the developing agent carrier portion in an example of a developing apparatus according to the present invention. 【図4】本発明に係る現像装置の一例を示す軸方向断面図である。 Is an axial cross-sectional view showing an example of a developing apparatus according to the present invention; FIG. 【図5】本発明に係る現像装置の他の例及び感光ドラムとの位置関係を示す断面図である。 5 is a cross-sectional view showing the positional relationship between the other examples and the photosensitive drum of a developing device according to the present invention. 【図6】本発明に係る現像装置に他の例を示す軸方向断面図である。 Is an axial sectional view showing another example in the developing apparatus according to the present invention; FIG. 【図7】従来の現像装置の一例を示す断面図である。 7 is a sectional view showing an example of a conventional developing apparatus. 【図8】従来の現像装置の他の例及び感光ドラムとの位置関係を示す断面図である。 8 is a sectional view showing the positional relationship between the other examples and the photosensitive drum of a conventional developing apparatus. 【図9】従来の現像装置の他の例を示す軸方向断面図である。 9 is an axial sectional view showing another example of a conventional developing apparatus. 【符号の説明】 1、100、101 現像装置2 現像容器3 現像室4 攪拌室5 第1の搬送スクリュー(循環手段) 6 第2の搬送スクリュー(循環手段) 7 隔壁8 第1現像スリーブ(第1の現像剤担持体) 8' マグネットローラ(第1の磁界発生手段) 9 規制ブレード(現像剤規制手段) 10 感光ドラム(像担持体) 11 第2現像スリーブ(第2の現像剤担持体) 11' マグネットローラ(第2の磁界発生手段) 12 現像剤排出口71、72 連通部 [Sign Description] 1,100,101 developing device 2 developer container 3 developing chamber 4 stirring chamber 5 first conveying screw (circulation means) 6 second conveying screw (circulation means) 7 partition wall 8 first developing sleeve (the 1 developer carrying member) 8 'magnet roller (first magnetic field generation means) 9 regulating blade (developer regulating means) 10 a photosensitive drum (image bearing member) 11 second developing sleeve (a second developer carrying member) 11 'magnet roller (second magnetic field generating means) 12 developer outlet 71 communicating portion

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Claims (1)

  1. 【特許請求の範囲】 【請求項1】 現像剤を収容する現像容器と、現像剤を担持してこれを像担持体の第1現像部に搬送する回転可能な第1の現像剤担持体と、を有し、前記像担持体上に形成された潜像を現像する現像装置において、 前記第1の現像剤担持体の上方に、現像剤を担持してこれを前記像担持体の第2現像部に搬送する、前記第1の現像剤担持体と同方向に回転可能な第2の現像担持体が配設され、前記第1の現像担持体から前記第2の現像担持体へ現像剤が受け渡され、 前記現像容器は、前記第1の現像担持体へ現像剤を供給する現像室と、該現像室の上方に配設され、前記第1現像部及び前記第2現像部を通過した現像剤を前記第2の現像担持体から回収する攪拌室と、前記現像室と前記攪拌室間で前記現像剤を循環させる A developing container [Claims 1 accommodating the developer, a rotatable first developer carrying member for conveying this by carrying a developer to a first developing unit of the image bearing member has, in a developing device for developing a latent image formed on the image bearing member, above the first developer carrying member, the second of which carries a developer said image bearing member conveyed to the developing portion, the first second developer carrying member rotatable developer carrying member in the same direction are disposed, the developer from the first developer carrying member to said second developer carrying member is is passed, the developer container is passed through a developing chamber for supplying a developer, is disposed above the developing chamber, the first developing portion and the second developing unit the the first developer carrying member a stirring chamber for collecting the the developer from said second developer carrying member, circulating the developer between the stirring chamber and the developing chamber 循環手段と、を有することを特徴とする現像装置。 A developing device, characterized in that it comprises a circulation means. 【請求項2】 前記第1の現像剤担持体の内部には、該第1の現像剤担持体回転方向で前記第1現像部より上流に配置された第1磁極と、該第1磁極より同回転方向上流に配置され、前記第1磁極と同極性である第2磁極と、を有する第1の磁界発生手段が設けられ、前記第1 Inside of claim 2 wherein said first developer carrying member, a first magnetic pole disposed upstream of the first developing portion in the first developer carrying member rotational direction, from the first magnetic pole are arranged in the same rotational direction upstream, a second magnetic pole is the first pole of the same polarity, the first magnetic field generating means having disposed, said first
    磁極の対向位置近傍に、前記第1の現像剤担持体が担持する現像剤量を規制する現像剤規制手段を配設することを特徴とする請求項1の現像装置。 Near opposite positions of the magnetic poles, the developing apparatus of claim 1, wherein said first developer carrying member is characterized by disposing the developer regulating means for regulating the amount of developer carrying. 【請求項3】 前記第1の現像剤担持体と前記第2の現像剤担持体のうち少なくとも1つに交流電圧を印加することを特徴とする請求項1又は2の現像装置。 Wherein said first developer carrying member and said second developer developing apparatus according to claim 1 or 2, characterized in that an AC voltage is applied to at least one of the carriers. 【請求項4】 前記現像室における、前記循環手段による現像剤搬送方向最下流近傍の外壁に現像剤の剤面高さがある一定以上になった場合に現像剤を排出するための排出口を有することを特徴とする請求項1、2又は3の現像装置。 In wherein said developing chamber, a discharge port for discharging the developer when the developer surface height of the developer has become constant or in the outer wall of the developer conveying direction downstream vicinity by the circulation means a developing device according to claim 1, 2 or 3, characterized in that it has. 【請求項5】 前記現像容器は、トナーと磁性キャリアを含む現像剤を収容することを特徴とする請求項1〜4 Wherein said developer container, according to claim, characterized in that they contain a developer including toner and magnetic carrier 1-4
    のいずれかの項に記載の現像装置。 A developing device according to any one of the paragraphs. 【請求項6】 前記現像容器に、前記磁性キャリアが補給されることを特徴とする請求項5の現像装置。 Wherein said developing container, a developing apparatus according to claim 5, wherein the magnetic carrier is characterized in that it is replenished. 【請求項7】 表面に潜像が形成される像担持体と、請求項1〜6のいずれかの項に記載の現像装置と、が備えられ、記録材に画像を形成することを特徴とする画像形成装置。 An image bearing member a latent image to 7. A surface is formed, a developing device according to any one of claims 1 to 6, is provided, and characterized by forming an image on a recording material An image forming apparatus.
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JP2002127479A JP3950735B2 (en) 2002-04-26 2002-04-26 A developing device and image forming apparatus
US10420838 US6973281B2 (en) 2002-04-26 2003-04-23 Developing apparatus with two developing chamber-rotatable member pairs
EP20120153575 EP2450753A3 (en) 2002-04-26 2003-04-24 Developing device
EP20030009317 EP1357443B1 (en) 2002-04-26 2003-04-24 Developing device
CN 03122483 CN100430835C (en) 2002-04-26 2003-04-28 Developing apparatus
US11171541 US7099609B2 (en) 2002-04-26 2005-07-01 Developing device

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JP2007133100A (en) * 2005-11-09 2007-05-31 Canon Inc Replenisher developer and development method using the same
JP2007240619A (en) * 2006-03-06 2007-09-20 Canon Inc Developing device
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US7853186B2 (en) 2005-09-07 2010-12-14 Canon Kabushiki Kaisha Developing apparatus featuring multiple magnetic rollers
US8626034B2 (en) 2011-02-28 2014-01-07 Ricoh Company, Ltd. Development device, and image forming apparatus and process cartridge incorporating same
US8989621B2 (en) 2011-08-01 2015-03-24 Ricoh Company, Ltd. Development device, and process cartridge and image forming apparatus including same
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US9316950B2 (en) 2012-04-17 2016-04-19 Ricoh Company, Ltd. Development device, process cartridge, image forming apparatus incorporating same, and developer amount adjustment method therefor
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JP2005309218A (en) * 2004-04-23 2005-11-04 Canon Inc Developing device and image forming apparatus
JP4641383B2 (en) * 2004-04-23 2011-03-02 キヤノン株式会社 Image forming apparatus
EP1628171A1 (en) 2004-04-27 2006-02-22 Canon Kabushiki Kaisha Developing method for an image forming apparatus and developing device using the same
US7272348B2 (en) 2004-04-27 2007-09-18 Canon Kabushiki Kaisha Developing method using a developer with a specified degree of compression and shearing stress
US7853186B2 (en) 2005-09-07 2010-12-14 Canon Kabushiki Kaisha Developing apparatus featuring multiple magnetic rollers
JP2007133100A (en) * 2005-11-09 2007-05-31 Canon Inc Replenisher developer and development method using the same
JP2007240619A (en) * 2006-03-06 2007-09-20 Canon Inc Developing device
JP2009025597A (en) * 2007-07-20 2009-02-05 Canon Inc Image forming method
US8626034B2 (en) 2011-02-28 2014-01-07 Ricoh Company, Ltd. Development device, and image forming apparatus and process cartridge incorporating same
US8989621B2 (en) 2011-08-01 2015-03-24 Ricoh Company, Ltd. Development device, and process cartridge and image forming apparatus including same
US9316950B2 (en) 2012-04-17 2016-04-19 Ricoh Company, Ltd. Development device, process cartridge, image forming apparatus incorporating same, and developer amount adjustment method therefor
US9310715B2 (en) 2012-12-17 2016-04-12 Ricoh Company, Ltd. Developing device and image forming apparatus
US9405223B2 (en) 2014-06-12 2016-08-02 Ricoh Company, Ltd. Developing device, image forming apparatus, and process cartridge

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