JP2001235947A - Electrostatic recorder - Google Patents
Electrostatic recorderInfo
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- JP2001235947A JP2001235947A JP2000049070A JP2000049070A JP2001235947A JP 2001235947 A JP2001235947 A JP 2001235947A JP 2000049070 A JP2000049070 A JP 2000049070A JP 2000049070 A JP2000049070 A JP 2000049070A JP 2001235947 A JP2001235947 A JP 2001235947A
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- Prior art keywords
- potential
- image
- electrostatic
- recording medium
- electrostatic recording
- 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.)
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- Electrostatic Charge, Transfer And Separation In Electrography (AREA)
- Control Or Security For Electrophotography (AREA)
Abstract
Description
【０００１】[0001]
【発明の属する技術分野】本発明は、静電記録装置に関
するものであり、特に高精細記録像を得るに適した静電
記録装置に関するものである。The present invention relates to an electrostatic recording apparatus, and more particularly to an electrostatic recording apparatus suitable for obtaining a high-definition recorded image.
【０００２】[0002]
【従来の技術】静電記録装置の一形態として知られるデ
ジタル印刷機器は、オンデマンドパブリッシングに代表
されるように、これまでの印刷方法を凌ぐ利点を持ち、
高速化、高精細化印字の方法が追求されている。2. Description of the Related Art Digital printing equipment, which is known as a form of electrostatic recording apparatus, has advantages over conventional printing methods, as represented by on-demand publishing.
High-speed, high-definition printing methods are being pursued.
【０００３】静電記録装置に用いられる記録方法として
代表的である電子写真方法においても、これらの要求を
満たすよう光学系、静電記録体（例えば誘電体や感光体
等である）、現像技術、静電転写技術、加熱加圧定着技
術、清掃系にわたって一連の改良が進められている。[0003] In an electrophotographic method, which is a typical recording method used in an electrostatic recording apparatus, an optical system, an electrostatic recording medium (for example, a dielectric or a photoconductor), and a developing technique are required to satisfy these requirements. A series of improvements have been made in electrostatic transfer technology, heat and pressure fixing technology, and cleaning systems.
【０００４】そして一連の改良の結果、静電記録体上に
形成された記録像（例えばトナー像である）は、静電記
録体に形成される潜像に対し大きさ、形状とも一定の関
係を満たし高精細印字を実現してはいるものの、静電転
写に際しトナー像の大きさおよび形状に乱れが生じ、高
精細印字を妨げる要因として認識されてきた。As a result of a series of improvements, a recorded image (for example, a toner image) formed on an electrostatic recording medium has a fixed relationship in size and shape with respect to a latent image formed on the electrostatic recording medium. Although high-definition printing is achieved by satisfying the above conditions, the size and shape of the toner image are disturbed during electrostatic transfer, and this has been recognized as a factor that hinders high-definition printing.
【０００５】この原因は、トナー像を保持した記録媒体
（主に用紙である）が静電記録体から剥離する過程に際
し、両者が高電圧帯電状態にあるため剥離放電、すなわ
ち間隙空気層に一定以上の電圧が印加される時、空気層
のイオン化に伴ういわゆるパッシェン放電が発生し、こ
の時の衝撃的過大電流がトナー像を乱してしまうのだと
考えられている。[0005] This is because when the recording medium (mainly paper) holding the toner image is peeled off from the electrostatic recording medium, both are in a high voltage charging state, and the peeling discharge, that is, the gap air layer is constant. It is considered that when the above voltage is applied, a so-called Paschen discharge occurs due to the ionization of the air layer, and a shocking excessive current at this time disturbs the toner image.
【０００６】そこで従来技術においては、転写後で剥離
前の段階において交流（ＡＣ）除電を施すようにした構
成が知られている。しかし、上記構成を高速印字に対応
させるには記録媒体と静電記録体とを平らな状態で接触
させるか、あるいは静電記録体がドラム形状であるなら
ば記録媒体を静電記録体外周に所定長さだけ巻き付ける
ようにし、接触面を増やし接触状態で除電手段を設置さ
せる必要が生じてくる。Therefore, in the prior art, there is known a configuration in which alternating current (AC) static elimination is performed after transfer and before separation. However, in order to make the above configuration correspond to high-speed printing, the recording medium is brought into contact with the electrostatic recording medium in a flat state, or if the electrostatic recording medium is a drum shape, the recording medium is placed around the electrostatic recording medium. It is necessary to wind the wire by a predetermined length, increase the contact surface, and install the static eliminator in the contact state.
【０００７】ところが、記録媒体と静電記録体の接触面
を増加させた場合には、記録媒体と静電記録体の走行速
度を同速度に維持することが難しく、この相対速度差に
伴い印字像乱れが生じてしまうという別の問題点を招い
ていた。However, when the contact surface between the recording medium and the electrostatic recording medium is increased, it is difficult to maintain the traveling speed of the recording medium and the electrostatic recording medium at the same speed. Another problem is that image disturbance occurs.
【０００８】また、上述の記録媒体と静電記録体とを平
らな状態で接触させる構成においては、静電記録体は例
えば薄いシームレスの感光体ベルトとして使用されるこ
とになるが、ベルト材の温度や湿度の変化による伸縮
や、長期間使用に際しての伸び、ダレの発生は高速印字
に際し克服しなければならない課題とされていた。In the above-described configuration in which the recording medium is brought into contact with the electrostatic recording medium in a flat state, the electrostatic recording medium is used, for example, as a thin seamless photosensitive belt. It has been considered that expansion and contraction due to changes in temperature and humidity, elongation during long-term use, and generation of sagging must be overcome in high-speed printing.
【０００９】一方、静電記録体が感光体ドラムのような
場合には、形状の加工精度が高く、剛性強度、変形に耐
久性を持つことが可能であるため、高速印字においは感
光体ドラムの利用が好適であり、記録媒体と感光体ドラ
ムの接触は両者の速度差発生を考慮し機械精度の観点か
ら線接触が望ましいと考えられていた。しかし、静電記
録体が感光体ドラムでは機器構成の観点から転写直後の
剥離前ＡＣ除電は難しいことが実状であった。On the other hand, when the electrostatic recording medium is a photosensitive drum, the processing accuracy of the shape is high, and the rigidity and the durability of the deformation are possible. It has been considered that the contact between the recording medium and the photosensitive drum is preferably a line contact from the viewpoint of mechanical accuracy in consideration of the speed difference between the two. However, when the electrostatic recording medium is a photosensitive drum, it is difficult to remove the AC before the separation immediately after the transfer from the viewpoint of the device configuration.
【００１０】[0010]
【発明が解決しようとする課題】上述の説明から、転写
後の剥離過程において、静電記録体が感光体ドラムや感
光体ベルトに関わらず、記録媒体と静電記録体の低電圧
化、非帯電状態を実現することが高精細印字の課題とな
る。この課題を、電子写真静電記録方法の静電潜像形
成、現像、転写の各工程における、電位形成状況に立ち
返り説明する。電子写真記録法においては、通常、暗部
にて静電記録体となる感光体表面をプラスまたはマイナ
スの極性にて数百ボルト乃至数千ボルトの初期電圧Ｖ0
に帯電させ、次に帯電した感光体に像露光を行い、光が
照射された部位の電位Ｖａを略±数十ボルト程度にまで
降下させ、感光体表面に光が照射された部位と照射され
ていない部位とを際立つ電位差で識別し静電潜像として
形成し、静電潜像の可視化である現像が行われる。な
お、現像方式は反転現像方式と正規現像方式とに大別さ
れる。From the above description, it can be seen from the above description that in the peeling process after the transfer, the voltage of the recording medium and the electrostatic recording medium can be reduced, and the electrostatic recording medium can be used regardless of the photosensitive drum or the photosensitive belt. Achieving a charged state is an issue of high-definition printing. This problem will be described by returning to the state of potential formation in each step of forming, developing, and transferring an electrostatic latent image in the electrophotographic electrostatic recording method. In an electrophotographic recording method, usually, an initial voltage V 0 of several hundred volts to several thousand volts is applied to the surface of a photoreceptor serving as an electrostatic recording medium in a dark portion with a positive or negative polarity.
Then, the charged photoreceptor is subjected to image exposure, and the potential Va of the light-irradiated portion is lowered to about ± several tens of volts, so that the light-irradiated portion is irradiated with the light-irradiated portion. The remaining portion is identified by a remarkable potential difference, formed as an electrostatic latent image, and development for visualizing the electrostatic latent image is performed. The developing method is roughly classified into a reversal developing method and a regular developing method.
【００１１】ここで、感光体としてマイナス帯電の有機
感光体を用い、現像方式としてマイナス帯電トナーを用
いる反転現像方式を採用した場合を前提として考える
と、光照射部分Ｖａは画像部電位を形成し、トナー粒子
は光照射部分Ｖａに堆積し記録像を作り、初期電位Ｖ0
の領域にはトナー像が付着せず背景部として表現され
る。Here, assuming that a negatively charged organic photoreceptor is used as a photoreceptor and a reversal developing method using a negatively charged toner is used as a developing method, the light irradiated portion Va forms an image portion potential. , The toner particles are deposited on the light irradiated portion Va to form a recorded image, and the initial potential V 0
The toner image is not adhered to the region of, and is expressed as a background portion.
【００１２】また、現像工程においては一般的に現像バ
イアス電位Ｖｂが印加されており、静電記録体の画像部
に現像されたトナー像の表面電位Ｖｒは現像バイアス電
位Ｖｂに等しく（Ｖｒ＝Ｖｂ）なるのが理想的現像条件
であるのだが、マイナス帯電感光体、反転現像方式、マ
イナス帯電トナー粒子を使う電子写真記録法の現像後の
状態においては、一般にＶ0＜Ｖｂ＜Ｖｒ＜Ｖａ≦０の
関係を示し、絶対値として書き直すと反転現像方式の場
合は０≦｜Ｖａ｜＜｜Ｖｒ｜＜｜Ｖｂ｜＜｜Ｖ 0｜の関
係となっている。In the developing step, a developing bag is generally used.
The ias potential Vb is applied, and the image area of the electrostatic recording medium is
The surface potential Vr of the toner image developed on the
(Vr = Vb) is the ideal development condition
However, the negatively charged photoreceptor, reversal development method,
Electrophotographic recording method using negatively charged toner particles after development
In the state, V0<Vb <Vr <Va ≦ 0
Indicate the relationship and rewrite it as an absolute value.
In this case, 0 ≦ | Va | <| Vr | <| Vb | <| V 0|
I am in charge.
【００１３】上記現像工程によって感光体上に形成され
たトナー像は、次に転写器によって用紙へ転写されるこ
ととなる。転写器の転写電極には、トナー粒子の帯電極
性と逆極性の電圧Ｖｔが印加され、感光体上のトナー像
を静電引力により用紙側へ静電吸着させている。このた
め、転写電圧Ｖｔと静電潜像の光照射部電位（画像部電
位）Ｖａの電位差（Ｖｔ−Ｖａ）は、転写電圧Ｖｔと初
期電位（背景部電位）Ｖ0の電位差（Ｖｔ−Ｖ0）に比べ
小さい値となる（｜Ｖｔ−Ｖａ｜＜｜Ｖｔ−Ｖ 0｜）。The toner image formed on the photoreceptor in the developing step is transferred to paper by a transfer unit. A voltage Vt having a polarity opposite to the charging polarity of the toner particles is applied to the transfer electrode of the transfer device, and the toner image on the photoconductor is electrostatically attracted to the paper side by electrostatic attraction. Therefore, the potential difference (Vt−Va) between the transfer voltage Vt and the light irradiation portion potential (image portion potential) Va of the electrostatic latent image is the potential difference (Vt−V) between the transfer voltage Vt and the initial potential (background portion potential) V 0. a small value compared with 0) (| Vt-Va | <| Vt-V 0 |).
【００１４】一方、正規現像方式を用いた場合には、上
述の反転現像方式とは逆に、光が照射されない部位の電
位Ｖ0の部分が画像部電位となり、この画像部電位領域
に電位Ｖ0と逆極性のトナー粒子が付着し現像して記録
像を形成し、光が照射された部位の電位Ｖａにはトナー
は付着されず、背景部をなすこととなる。On the other hand, when the normal development method is used, the portion of the potential V 0 of the portion not irradiated with light becomes the image portion potential, and the potential V Toner particles having a polarity opposite to that of 0 are attached and developed to form a recorded image, and no toner is attached to the potential Va at a portion irradiated with light, so that a background portion is formed.
【００１５】従って、正規現像方式の場合の各電位関係
は、絶対値で表した場合、０≦｜Ｖａ｜＜｜Ｖｂ｜＜｜
Ｖｒ｜＜｜Ｖ0｜の関係となり、上述の反転現像方式の
場合と比較してみると現像バイアス電位Ｖｂと、トナー
像の表面電位Ｖｒとの関係が入れ替わっている。Therefore, the relationship between the potentials in the case of the normal development system, when expressed by an absolute value, is 0 ≦ | Va | <| Vb | <|
Vr | <| V 0 |, and the relationship between the developing bias potential Vb and the surface potential Vr of the toner image is switched as compared with the case of the above-described reversal developing method.
【００１６】また、トナー粒子は静電潜像と逆極性のた
め、転写電圧Ｖｔは静電潜像と同極性となり、感光体に
形成された静電潜像の画像部電位Ｖ0と転写電圧Ｖｔの
電位差（Ｖｔ−Ｖ0）は、転写電圧Ｖｔと背景部電位Ｖ
ａの電位差（Ｖｔ−Ｖａ）に比べ小さい値となる（｜Ｖ
ｔ−Ｖ0｜＜｜Ｖｔ−Ｖａ｜）。Since the toner particles have a polarity opposite to that of the electrostatic latent image, the transfer voltage Vt has the same polarity as that of the electrostatic latent image, and the image portion potential V 0 of the electrostatic latent image formed on the photosensitive member and the transfer voltage The potential difference (Vt−V 0 ) between Vt is the transfer voltage Vt and the background portion potential V
a smaller than the potential difference (Vt−Va)
t−V 0 | <| Vt−Va |).
【００１７】以上により反転現像方式および正規現像方
式に関わらず、転写電圧Ｖｔと感光体上の画像部電位と
の電位差は、転写電圧Ｖｔと感光体上の背景部電位との
電位差よりも小さいことが重要である。As described above, the potential difference between the transfer voltage Vt and the potential of the image portion on the photosensitive member is smaller than the potential difference between the transfer voltage Vt and the potential of the background portion on the photosensitive member irrespective of the reversal developing method and the normal developing method. is important.
【００１８】感光体としてマイナス帯電の感光体を用
い、現像方式としてマイナス帯電トナーを用いる反転現
像方式を採用した場合の静電転写工程についてさらに考
察する。ここで、転写電圧Ｖｔは、マイナス帯電トナー
に静電引力を付与しなければならないため、感光体の初
期電位と逆向き符号のプラス帯電である。プラス帯電の
転写電圧Ｖｔが印加すると、トナー層の空間的電位分布
には電位の極小値が出現し、トナー層に作用する電場、
すなわち静電力はトナー層電位分布の極小値を境に方向
が逆向きとなる。この結果、トナー層は感光体側と用紙
側へと分離し、一部は用紙へ転写され、残りは用紙に転
写されずに感光体上に残留してしまうことになる。The electrostatic transfer step in the case where a negatively charged photoreceptor is used as the photoreceptor and a reversal developing method using a negatively charged toner as a developing method is adopted will be further considered. Here, the transfer voltage Vt is positively charged with a sign opposite to the initial potential of the photoconductor since electrostatic attraction must be applied to the negatively charged toner. When the positive transfer voltage Vt is applied, a minimum value of the potential appears in the spatial potential distribution of the toner layer, and an electric field acting on the toner layer,
That is, the direction of the electrostatic force is opposite to the minimum value of the toner layer potential distribution. As a result, the toner layer is separated into the photoconductor side and the paper side, part of the toner layer is transferred to the paper, and the rest is not transferred to the paper but remains on the photoconductor.
【００１９】転写工程では感光体、トナー層および用紙
が形成する空間ギャップ幅は一定であり、静電場の作用
下でのトナー層の分離過程は、トナー層の圧縮により発
生するものと思われる。用紙側および感光体側へと分離
された記録像を形成するトナー層は、互いに平均電荷密
度も電位も等しく、このため静電記録像を作るトナー層
の静電転写工程、すなわち静電力の作用下、トナー層の
圧縮、分離過程で発生する間隙空気層の電位差ΔＶｒは
略０Ｖにあるものと考えられる。In the transfer step, the width of the space formed by the photosensitive member, the toner layer and the paper is constant, and the process of separating the toner layer under the action of the electrostatic field is thought to occur by the compression of the toner layer. The toner layers forming the recording images separated on the paper side and the photoreceptor side have the same average charge density and potential, and therefore, the electrostatic transfer process of the toner layer for forming the electrostatic recording image, that is, under the action of electrostatic force It is considered that the potential difference ΔVr of the gap air layer generated in the process of compressing and separating the toner layer is approximately 0V.
【００２０】一方、転写工程において感光体上の背景部
電位領域では、周辺にトナー層が形成されているため、
背景部電位領域と用紙との間にはトナー層の厚さに相当
する隙間が作られる。このため、トナー層の厚さに相当
する空気層が発生する。ここで、感光体上の背景部電位
Ｖ0も層形成のため修正されることになるが、それでも
用紙と感光体上の背景部電位領域とが作る間隙空気層の
電位差ΔＶｗは、転写電圧Ｖｔが正帯電であることから
大きな値を持つことになる。On the other hand, in the transfer process, in the background potential region on the photoreceptor, a toner layer is formed on the periphery,
A gap corresponding to the thickness of the toner layer is formed between the background potential region and the sheet. Therefore, an air layer corresponding to the thickness of the toner layer is generated. Here, the background potential V 0 on the photoconductor is also corrected for layer formation, but the potential difference ΔVw between the paper and the background air potential region formed on the photoconductor by the transfer voltage Vt Has a large value because it is positively charged.
【００２１】従って、転写工程中に空間的圧縮、分離に
伴いトナー層に発生する間隙空気層の電位差ΔＶｒと、
用紙と感光体の背景部電位領域とが作る間隙空気層の電
位差ΔＶｗを比較するとΔＶｒ≪ΔＶｗになる。Accordingly, the potential difference ΔVr of the gap air layer generated in the toner layer due to the spatial compression and separation during the transfer process is represented by:
When the potential difference ΔVw of the gap air layer formed by the paper and the background potential region of the photoconductor is compared, ΔVr≪ΔVw.
【００２２】ここでさらに、静電転写直後の感光体と、
トナー像が転写された用紙との分離過程を考える。上述
のΔＶｒ、ΔＶｗをそれぞれの間隙空気層からなるコン
デンサの電位差と見なすと、静電容量Ｃ、電位差ΔＶお
よび実効電荷Ｑの関係はΔＶ＝Ｑ／Ｃであり、転写直後
の電荷は時間変化が発生しても小さく、一定値にあると
考えることができる。Here, further, a photosensitive member immediately after the electrostatic transfer,
A separation process from a sheet on which a toner image is transferred will be considered. If the above-mentioned ΔVr and ΔVw are regarded as potential differences of the capacitors formed of the respective gap air layers, the relationship among the capacitance C, the potential difference ΔV and the effective charge Q is ΔV = Q / C, and the charge immediately after the transfer has a time change. Even if it occurs, it can be considered to be small and at a constant value.
【００２３】上記の圧縮分離したトナー層の間隙空気層
の実効電荷をＱｒ、間隙空気層をｄｒ0、当該部分の面
積をＳｒ、背景部電位領域の間隙空気層の実効電荷をＱ
ｗ、間隙空気層をｄｗ0、当該部分の面積をＳｗ、空気
の誘電率をε0とすると、 ΔＶｒ＝Ｑｒ・ｄｒ0／Ｓｒ・ε0 …（１） ΔＶｗ＝Ｑｗ・ｄｗ0／Ｓｗ・ε0 …（２） となる。ここで、トナー層の実効電荷表面密度をｑｒ＝
Ｑｒ／Ｓｒ、背景部の実効電荷表面密度をｑｗ＝Ｑｗ／
Ｓｗとすると、 ΔＶｒ＝ｑｒ・ｄｒ0／ε0 …（３） ΔＶｗ＝ｑｗ・ｄｗ0／ε0 …（４） となる。感光体と用紙の剥離過程に伴い各々の間隙空気
層は、 ｄｒ(t)＝ｄｒ0＋ｋｔ …（５） ｄｗ(t)＝ｄｗ0＋ｋｔ …（６） の形で時間的に拡大し、剥離過程に入るものとする。こ
こで、ｋはｋ＞０の剥離速度係数である。従って、転写
直後の感光体と、トナー層を含む用紙の剥離過程では、
剥離開始時刻をｔ＝０として間隙空気層の電位差は、 ΔＶｒ(t)＝(ｑｒ／ε0)・(ｄｒ0＋ｋｔ) …（７） ΔＶｗ(t)＝(ｑｗ／ε0)・(ｄｗ0＋ｋｔ) …（８） となる。ここで、間隙空気層は式（５）および式（６）
によって与えており、必ずしも感光体ドラムと、平らな
用紙との線接触後の幾何学的剥離状態を表してはいない
が、重要なことは表式に関係なく、間隙空気層の時間変
化部分は画像部領域も背景部領域も同じ時間変化を示す
と言うことである。従って、ΔＶｒ(t)、ΔＶｗ(t)は、
ΔＶｒ≪ΔＶｗの関係を維持しながら、大きな電位差へ
と変化することになる。The effective charge of the gap air layer of the compressed and separated toner layer is Qr, the gap air layer is dr 0 , the area of the portion is Sr, and the effective charge of the gap air layer in the background potential area is Q.
Assuming that w, the gap air layer is dw 0 , the area of the portion is Sw, and the dielectric constant of air is ε 0 , ΔVr = Qr · dr 0 / Sr · ε 0 (1) ΔVw = Qw · dw 0 / Sw · ε 0 (2) Here, the effective charge surface density of the toner layer is represented by qr =
Qr / Sr, and the effective charge surface density of the background portion is qw = Qw /
If Sw, ΔVr = qr · dr 0 / ε 0 (3) ΔVw = qw · dw 0 / ε 0 (4) Each of the gap air layer with the desquamation process of the photoreceptor and the paper, dr (t) = dr 0 + kt ... (5) dw (t) = expanded dw 0 + kt ... (6) form temporally in the peeling Shall enter the process. Here, k is a peeling rate coefficient of k> 0. Therefore, in the process of separating the photoconductor immediately after the transfer and the paper including the toner layer,
Assuming that the separation start time is t = 0, the potential difference of the gap air layer is ΔVr (t) = (qr / ε 0 ) · (dr 0 + kt) (7) ΔVw (t) = (qw / ε 0 ) · (dw 0 + kt) (8) Here, the gap air layer is expressed by the equations (5) and (6).
, And does not necessarily represent the state of geometrical peeling after line contact between the photosensitive drum and flat paper, but the important thing is that regardless of the expression, the time-varying portion of the gap air layer is This means that both the image area and the background area show the same time change. Therefore, ΔVr (t) and ΔVw (t) are
While maintaining the relationship of ΔVr≪ΔVw, the potential changes to a large potential difference.
【００２４】パッシェン放電は、間隙空気層にある一定
以上の電圧が印加された時に発生する空気のイオン化放
電破壊現象であり、ΔＶｒ(t)≪ΔＶｗ(t)であることか
ら、用紙上の画像部よりも背景部に集中することになる
が、背景部はトナーが付着していないためパッシェン放
電が発生してもトナー像それ自体には無関係であり、静
電転写過程のパッシェン放電のトナー像への影響に関し
ては、トナー像と背景部との境界であるトナー像の周縁
輪郭部分がより強く影響されることが以上の考察から結
論できることになる。The Paschen discharge is an ionization discharge destruction phenomenon of air generated when a certain voltage or more is applied to the gap air layer, and ΔVr (t) ≪ΔVw (t). Although the toner is more concentrated in the background than in the area, even if a Paschen discharge occurs because the toner is not attached to the background, the toner image itself is irrelevant even if the Paschen discharge occurs. From the above consideration, it can be concluded that the influence on the peripheral edge of the toner image, which is the boundary between the toner image and the background, is more strongly affected.
【００２５】事実、現像後転写前の感光体上のトナー像
と、転写後の用紙上のトナー像を比較すると、静電転写
における印字欠陥はトナー像の周縁輪郭部に集中してお
り、しかも転写電圧Ｖｔの大小に拘わらず発生している
ことがわかる。さらに、数ｃｍ2のベタ画像を検討する
と、例え濃度が薄い場合であっても転写ボケはベタ画像
の周縁輪郭部に集中しており、上述の考察を裏付けてい
るものと考えられる。In fact, when the toner image on the photoreceptor before development and transfer is compared with the toner image on paper after transfer, print defects in electrostatic transfer are concentrated on the peripheral contour of the toner image. It can be seen that this occurs regardless of the magnitude of the transfer voltage Vt. Further, when examining a solid image of several cm 2 , even if the density is low, the transfer blur is concentrated on the peripheral edge portion of the solid image, which seems to support the above consideration.
【００２６】以上の考察は、正規現像方式／反転現像方
式、プラス帯電感光体／マイナス帯電感光体の何れの組
み合わせに対しても成立し、パッシェン放電はΔＶｒ≪
ΔＶｗの状況の下、感光体上のトナー層が堆積する画像
部よりも背景部に集中して発生し、このため背景部と画
像部の境界領域をなすトナー像の周縁輪郭部分が主に影
響を受け、トナー像のボケ、像歪み現象を発生している
と結論付けることができる。従って、本発明の目的は、
記録媒体と静電記録体との剥離過程において発生するパ
ッシェン放電を抑止することが可能で、記録像の周縁、
輪郭部分における転写ボケ、印字乱れの発生を抑止する
ことが可能な静電記録装置を提供することにある。The above considerations hold true for any combination of the normal development system / reversal development system and the positively charged photosensitive member / negatively charged photosensitive member, and the Paschen discharge is ΔVrΔ.
Under the condition of ΔVw, the toner layer on the photoreceptor occurs more concentrated on the background than on the image area where the toner layer is deposited. Therefore, the peripheral contour of the toner image forming the boundary area between the background and the image area is mainly affected. Accordingly, it can be concluded that the toner image is blurred and the image distortion phenomenon occurs. Therefore, the object of the present invention is to
It is possible to suppress the Paschen discharge that occurs during the separation process between the recording medium and the electrostatic recording medium, and it is possible to suppress the periphery of the recorded image,
It is an object of the present invention to provide an electrostatic recording apparatus capable of suppressing the occurrence of transfer blur and print disturbance in a contour portion.
【００２７】[0027]
【課題を解決するための手段】上記の目的は、静電記録
体上に画像部電位と背景部電位とを有する静電潜像を形
成する静電潜像形成手段と、前記静電潜像を保持した静
電記録体に記録剤を供給し、前記画像部電位の領域を記
録像として可視化させる現像手段と、前記静電記録体上
に形成された記録像を記録媒体に転写させる転写手段と
を備えた静電記録装置において、前記現像手段と前記転
写手段との間に配置され、前記静電記録体に向けて所定
極性のイオンを供給するイオン生成手段と、前記静電記
録体表面と前記イオン生成手段との間に配置され、前記
画像部電位と背景部電位との間の電位に設定されたグリ
ッド電位を有し、前記記録像の表面電位および前記背景
部電位の内、少なくとも前記背景部電位を前記グリッド
電位に同等となるように前記イオンの運動を制御するグ
リッド電極手段とを有することにより達成される。SUMMARY OF THE INVENTION It is an object of the present invention to provide an electrostatic latent image forming means for forming an electrostatic latent image having an image portion potential and a background portion potential on an electrostatic recording medium. Developing means for supplying a recording agent to the electrostatic recording medium holding the image and visualizing the area of the image portion potential as a recording image, and transferring means for transferring the recording image formed on the electrostatic recording medium to a recording medium And an ion generating means disposed between the developing means and the transfer means for supplying ions of a predetermined polarity toward the electrostatic recording medium; and a surface of the electrostatic recording medium. And between the ion generating means, having a grid potential set to a potential between the image portion potential and the background portion potential, at least of the surface potential of the recorded image and the background portion potential The background portion potential is equivalent to the grid potential Is accomplished by having the grid electrode means for controlling the movement of sea urchin said ions.
【００２８】上記、パッシェン放電解消手段において、
現像後、転写前の感光体上の電位、すなわち初期電位、
画像部潜像電位、背景部電位、および現像後トナー像の
表面電位の関係は、本発明の根幹となるため、静電電位
分布を与えるポアッソン式を使い詳細に説明する。な
お、ここでの説明は反転現像方式に基づくものとする。In the above Paschen discharge eliminating means,
After development, the potential on the photoconductor before transfer, that is, the initial potential,
Since the relationship between the image portion latent image potential, the background portion potential, and the surface potential of the toner image after development is the basis of the present invention, the relationship will be described in detail using a Poisson equation that gives an electrostatic potential distribution. The description here is based on the reversal development method.
【００２９】トナー粒子とキャリア粒子とからなる２成
分乾式現像剤は現像機内で攪拌され、トナーの特性帯電
量（ｑ／ｍ）が決まる。現像剤は隙間Ｇのドクターギャ
ップを通過し、現像剤の厚さが規制されるとともに、ク
ローズドパック（濃密堆積）状態になる。現像ニップ領
域の厚さはドクターギャップに略等しい値に設定されて
いる。現像ニップ領域では、当初全体で電気的に中性状
態の現像剤は、現像バイアス電位Ｖｂの作用とあいまっ
て、画像部電位Ｖａとの間で静電力（±ｑ（Ｖｂ−Ｖ
ａ）／Ｇ）を受け、トナー粒子は現像剤層から浸み出
し、分離し、画像部電位Ｖａに供給され、トナー像を形
成する。The two-component dry developer composed of toner particles and carrier particles is stirred in a developing machine, and the characteristic charge amount (q / m) of the toner is determined. The developer passes through the doctor gap of the gap G, the thickness of the developer is regulated, and the developer enters a closed pack (dense accumulation) state. The thickness of the development nip region is set to a value substantially equal to the doctor gap. In the developing nip region, the developer in an initially electrically neutral state as a whole is coupled with an electrostatic potential (± q (Vb−V
In response to a) / G), the toner particles seep out of the developer layer, are separated, and supplied to the image portion potential Va to form a toner image.
【００３０】この時、トナー粒子は同種電荷で互いに斥
力を及ぼし、疎に分布したトナー層を作ることになるの
で、分離後のトナー層の体積電荷密度ρｔは、ρｔ＝
（ｑ／ｍ）ρｔｇ・Ｐと書くことができる。ここでρｔ
ｇはトナーの比重であり、Ｐはパッキング比（体積嵩密
度）である。トナー粒子が分離後の現像剤は、分離トナ
ー粒子が時間的に持ち出す電荷量に等しい、単位時間当
たりの電荷量を持つことになる。現像工程で形成される
トナー層の厚さをｄ2、トナー層形成後の現像剤厚さを
ｄ3とすると、トナー電荷密度ρｔ、現像剤の電荷密度
ρｃは単位時間に現像ニップを通過する体積に対して、
異符号等電荷量にあることから、感光体の周速をｖｒ、
現像機内の現像磁気ロールの周速をｖｍとすると、 ρｔ・ｖｒ・ｄ2＋ρｃ・ｖｍ・ｄ3＝０ …（９） （故に、ρｃ＝−ρｔ・ｄ2／ｈ・ｄ3、 ｈ＝ｖｍ／ｖ
ｒ）の関係が成立する。ここで、ｈは感光体と現像磁気
ロールとの周速比である。現像ニップ領域では、現像バ
イアス電位Ｖｂ印加の下、この過程が推移し、感光体
（電位Ｖａ）、トナー層（電荷密度ρｔ）、現像剤層
（電荷密度ρｃ）の三層が形成される。この状態に対し
ポアッソン式を解くとトナー層の電位分布φ（ｘ）は、 φ(x)＝Ｖｂ−(ρｔ／２ε2)(ｘ−ｘ2)2＋(ρc／２ε2)(ｘ−ｘ2)ｄ3＋(Ｊ／ε2 )(ｘ−ｘ2)−ＪＤ3 …（１０） 但し、Ｊ＝(1／ΣＤ)[Ｖｂ−Ｖａ−ρｔｄ2(Ｄ1+Ｄ2／２)−ρｃ(ｄ3／２)(Ｄ1+ Ｄ2)]…（１１） である。At this time, the toner particles exert a repulsive force on each other with the same kind of charge, thereby forming a sparsely distributed toner layer. Therefore, the volume charge density ρt of the separated toner layer is ρt =
(Q / m) ρtg · P. Where ρt
g is the specific gravity of the toner, and P is the packing ratio (volume bulk density). The developer after the separation of the toner particles has a charge amount per unit time, which is equal to the charge amount of the separated toner particles with time. Assuming that the thickness of the toner layer formed in the developing step is d 2 and the thickness of the developer after the formation of the toner layer is d 3 , the toner charge density ρt and the developer charge density ρc pass through the development nip per unit time. For volume,
Since the charge amounts are of different signs, the peripheral speed of the photoconductor is vr,
Assuming that the peripheral speed of the developing magnetic roll in the developing machine is vm, ρt · vr · d 2 + ρc · vm · d 3 = 0 (9) (Therefore, ρc = −ρt · d 2 / h · d 3 , h = vm / v
The relationship of r) is established. Here, h is a peripheral speed ratio between the photosensitive member and the developing magnetic roll. In the developing nip region, this process changes under the application of a developing bias potential Vb, and three layers of a photoconductor (potential Va), a toner layer (charge density ρt), and a developer layer (charge density ρc) are formed. When Poisson's equation is solved for this state, the potential distribution φ (x) of the toner layer becomes φ (x) = Vb− (ρt / 2ε 2 ) (xx− 2 ) 2 + (ρc / 2ε 2 ) (x− x 2) d 3 + (J / ε 2) (x-x 2) -JD 3 ... (10) where, J = (1 / ΣD) [Vb-Va-ρtd 2 (D 1 + D 2/2) -ρc (d 3/2) ( D 1 + D 2)] is a ... (11).
【００３１】ここで、ΣＤ＝(Ｄ1+Ｄ2+Ｄ3)、Ｄ1は感光
体の誘電厚さ（Ｄ1＝(ｄ1／ε1)）、Ｄ2はトナー層の誘
電厚さ（Ｄ2＝(ｄ2／ε2)）、Ｄ3は現像剤層の誘電厚さ
（Ｄ3＝(ｄ3／ε3)）である。また、ｘ1＝ｄ1、ｘ2＝ｄ
1＋ｄ2、ｘ3＝ｄ1＋ｄ2＋ｄ3である。（１０）式のトナ
ー層の電位分布は位置ｘに対し極値を持ち、 ｄφ／ｄｘ＝−(ρｔ/ε2)(ｘ−ｘ2)＋(ρｃ／２ε2)ｄ3+(Ｊ／ε2)…（１２） ｄφ／ｄｘ｜ｘ2＝０とすると、ｘ＝ｘ2位置で電位の極
小値にあり、ｘ≦ｘ2の範囲のトナー層に働く静電力は
感光体へ向うことになる。すなわち、現像ニップ領域で
現像剤から分離したトナー層が全域現像され、感光体へ
と堆積されトナー像を作る条件になる。 上記式（１３）が成立する時、トナー層の電位をφ＊と
すると、 感光体とトナー層界面：φ＊(ｘ1)＝Ｖａ＋ρｔ・ｄ2Ｄ1 …（１４） トナー層表面：φ＊(ｘ2)＝Ｖｂ−ρｔ・ｄ2Ｄ3／２ｈ …（１５） ＝Ｖａ＋ρｔ・ｄ2(Ｄ1+Ｄ2／２) …（１６） 静電記録体を有機感光体とし、初期電位Ｖ0＝−６５０
Ｖ、画像部（光照射部）電位Ｖａ＝−１００Ｖ、現像バ
イアス電位Ｖｂ＝−４００Ｖとし、反転現像トナーの電
荷密度ρｔ＜０とすると、静電記録体の画像部上のトナ
ー層表面電位は式（１５）から周速比ｈ＝∞の理想的状
態において、φ＊(ｘ2)＝Ｖｂとなり、式（１６）から
Ｖｂ≦φ＊(ｘ2)＜Ｖａ≦０の表面電位にあることがわ
かる。Here, ΔD = (D 1 + D 2 + D 3 ), D 1 is the dielectric thickness of the photoconductor (D 1 = (d 1 / ε 1 )), and D 2 is the dielectric thickness of the toner layer. (D 2 = (d 2 / ε 2 )), and D 3 is the dielectric thickness of the developer layer (D 3 = (d 3 / ε 3 )). Also, x 1 = d 1 , x 2 = d
1 is a + d 2, x 3 = d 1 + d 2 + d 3. The potential distribution of the toner layer in the formula (10) has an extreme value with respect to the position x, and dφ / dx = − (ρt / ε 2 ) (xx− 2 ) + (ρc / 2ε 2 ) d 3 + (J / ε 2 ) (12) Assuming that dφ / dx | x 2 = 0, the potential at the x = x 2 position is the minimum value, and the electrostatic force acting on the toner layer in the range of x ≦ x 2 is directed to the photoconductor. become. That is, the condition is such that the toner layer separated from the developer in the development nip region is entirely developed and deposited on the photosensitive member to form a toner image. When the above equation (13) holds, assuming that the potential of the toner layer is φ *, the interface between the photoconductor and the toner layer: φ * (x 1 ) = Va + ρt · d 2 D 1 (14) The surface of the toner layer: φ * (x 2) = Vb-ρt · d 2 D 3 / 2h ... (15) = Va + ρt · d 2 (D 1 + D 2/2) ... (16) the electrostatic recording material and an organic photoreceptor, the initial potential V 0 = -650
V, the image portion (light irradiation portion) potential Va = −100 V, the developing bias potential Vb = −400 V, and the charge density ρt <0 of the reversal developing toner, the toner layer surface potential on the image portion of the electrostatic recording medium is From the equation (15), φ * (x 2 ) = Vb in an ideal state with the peripheral speed ratio h = ∞, and from the equation (16), the surface potential is Vb ≦ φ * (x 2 ) <Va ≦ 0. I understand.
【００３２】一方、Ｖ0＜Ｖｂ＜０、ρt＜０であること
から、トナー粒子は感光体の背景部（非光照射部）には
堆積されず、この部分の表面電位は現像工程では電位Ｖ
0のまま殆ど変化しない。感光体上に形成されたトナー
像の表面電位をＶｒとすると、Ｖｒ＝φ＊(ｘ2)であ
り、現像後転写前の電位として、Ｖ0＜Ｖｂ＜Ｖｒ＜Ｖ
ａ≦０の関係が成立する。On the other hand, since V 0 <Vb <0 and ρt <0, the toner particles are not deposited on the background portion (non-light-irradiated portion) of the photosensitive member, and the surface potential of this portion is the potential in the developing process. V
Almost unchanged at 0 . Assuming that the surface potential of the toner image formed on the photoreceptor is Vr, Vr = φ * (x 2 ), and V 0 <Vb <Vr <V
The relationship a ≦ 0 holds.
【００３３】反転現像方式においては、転写電圧Ｖｔ＞
０を印加すると、Ｖｔ−Ｖ0＞Ｖｔ−Ｖｒとなり、上述
の式（１）、式（２）に対しΔＶｒ≦ΔＶｗが成立する
ことになる。In the reversal developing method, the transfer voltage Vt>
When 0 is applied, Vt−V 0 > Vt−Vr, and ΔVr ≦ ΔVw holds with respect to the above equations (1) and (2).
【００３４】以上の考察から反転現像方式においてトナ
ー像の周縁輪郭部分のパッシェン放電を抑止するには、
転写前の時点で、感光体の背景部電位Ｖ0の絶対値を選
択的に０Ｖに近い電圧値へと低下させるとよいことがわ
かる。From the above considerations, in order to suppress the Paschen discharge at the peripheral edge portion of the toner image in the reversal developing method,
It can be seen that it is preferable to selectively lower the absolute value of the background potential V 0 of the photoconductor to a voltage value close to 0 V before the transfer.
【００３５】[0035]
【発明の実施の形態】以下、本発明の実施例を説明す
る。なお、以下の説明においては帯電工程、露光工程お
よび現像工程に基づき感光体表面にトナー像を形成し、
続く転写工程によって前記トナー像を用紙に転写させ
る、いわゆる電子写真記録法を用いた静電記録装置図１
を例示しながら述べることとする。Embodiments of the present invention will be described below. In the following description, a toner image is formed on the surface of the photoconductor based on a charging process, an exposure process, and a developing process,
An electrostatic recording apparatus using a so-called electrophotographic recording method in which the toner image is transferred to a paper in a subsequent transfer step.
Will be described as an example.
【００３６】図１において、１は感光体ドラムであり、
矢印ａ方向に一定の速度で回転するように支持されてい
る。帯電器２は感光体ドラム１の表面に対向するように
配置され、この帯電器２と対向するように通過する感光
体ドラム１表面を均一に帯電する。帯電された感光体ド
ラム１表面を像露光するレーザ光３は、上位装置（図示
せず）からの印刷情報信号に従って感光体ドラム１表面
に画像部電位と背景部電位とからなる静電潜像を形成す
る。In FIG. 1, reference numeral 1 denotes a photosensitive drum,
It is supported so as to rotate at a constant speed in the direction of arrow a. The charger 2 is disposed so as to face the surface of the photoconductor drum 1, and uniformly charges the surface of the photoconductor drum 1 passing so as to face the charger 2. A laser beam 3 for imagewise exposing the charged surface of the photosensitive drum 1 forms an electrostatic latent image composed of an image portion potential and a background portion potential on the surface of the photosensitive drum 1 in accordance with a print information signal from a higher-level device (not shown). To form
【００３７】現像装置４は、静電潜像が形成された感光
体ドラム１の表面と対向するように配置される。この現
像装置４は、静電潜像の静電力と、現像磁気ロール４ａ
に印加された現像バイアス電圧との作用によってトナー
粒子を感光体ドラム１に付着させ、前記画像部電位領域
をトナー像として可視化する。The developing device 4 is arranged so as to face the surface of the photosensitive drum 1 on which the electrostatic latent image has been formed. The developing device 4 includes an electrostatic force of an electrostatic latent image and a developing magnetic roll 4a.
The toner particles adhere to the photosensitive drum 1 by the action of the developing bias voltage applied to the photosensitive drum 1, and the image area potential region is visualized as a toner image.
【００３８】感光体ドラム１上に形成されたトナー像
は、用紙５の背面側からトナーと反対極性の電荷を付与
する転写器６の静電吸引作用により、感光体ドラム１か
ら用紙５に転写され、矢印ｂ方向へ搬送されて行く。な
お、トナー像が転写された用紙５はその後、定着装置
（図示せず）へ送り込まれ、トナー像は用紙５に定着さ
れる。The toner image formed on the photosensitive drum 1 is transferred from the photosensitive drum 1 to the paper 5 from the back side of the paper 5 by the electrostatic attraction of the transfer unit 6 which applies a charge of the opposite polarity to the toner. And is conveyed in the direction of arrow b. The sheet 5 onto which the toner image has been transferred is then sent to a fixing device (not shown), and the toner image is fixed on the sheet 5.
【００３９】一方、転写器６通過後の感光体ドラム１表
面に残留したトナーや紙粉等の異物は、クリーナ７を通
過することにより感光体ドラム１表面から除去される。On the other hand, foreign matters such as toner and paper powder remaining on the surface of the photosensitive drum 1 after passing through the transfer unit 6 are removed from the surface of the photosensitive drum 1 by passing through the cleaner 7.
【００４０】なお、８は感光体ドラム上に形成されたト
ナー像の表面電位を検出する電位センサ、９は感光体表
面に向けて所定極性のイオンを供給するイオン生成手段
として例示されたコロナ帯電器、１０は感光体ドラム１
表面とコロナ帯電器９との間に設けられたグリッド電
極、１１はコロナ帯電器９に設けられたコロナワイヤに
電圧を印加するためのコロナワイヤ用電源、１２はグリ
ッド電極１０に電圧を印加するためのグリッド用電源、
１３は電位センサ８の出力に基づいてコロナワイヤおよ
びグリッド電極への印加電圧を制御する制御装置であ
る。Reference numeral 8 denotes a potential sensor for detecting the surface potential of the toner image formed on the photoreceptor drum, and 9 denotes a corona charging device exemplified as ion generating means for supplying ions of a predetermined polarity toward the photoreceptor surface. , 10 is a photosensitive drum 1
A grid electrode provided between the surface and the corona charger 9, 11 is a corona wire power supply for applying a voltage to the corona wire provided in the corona charger 9, and 12 is a voltage applied to the grid electrode 10. Power supply for the grid,
Reference numeral 13 denotes a control device that controls the voltage applied to the corona wire and the grid electrode based on the output of the potential sensor 8.
【００４１】次に、上述したコロナ帯電器９およびグリ
ッド電極１０の詳細を図２を用いて説明する。なお、図
２においては該当部分を平面的に図示している。Next, details of the above-described corona charger 9 and grid electrode 10 will be described with reference to FIG. In FIG. 2, the corresponding portion is shown in a plan view.
【００４２】図２において、電源１１は高圧電源であ
り、交流（ＡＣ）であっても直流（ＤＣ）であってもよ
く、また、直流に交流を重畳させて用いる場合であって
もよい。図２において、Ｇは接地であり、コロナイオン
は、高電圧に印加された細い金属製のコロナワイア９ａ
と、これを取り囲む接地された金属製の筐体９ｂとの間
で発生する。高圧電源１１の極性に従い、筐体９ｂの開
口部からイオン化した正イオンあるいは負電荷の電子、
負イオンが放出される。グリッド電極１０は金属メッシ
ュから作られ、コロナ帯電器９に対し生成イオンの流れ
を制御するものであり、本実施例においては直流高圧電
源１２に結線されているが、直流に交流を重畳させて
も、または場合によっては交流高電圧を用いてもよい。In FIG. 2, the power supply 11 is a high-voltage power supply, may be an alternating current (AC) or a direct current (DC), or may be a case where an alternating current is superimposed on a direct current. In FIG. 2, G is a ground, and the corona ion is a thin metal corona wire 9a applied to a high voltage.
And a grounded metal housing 9b surrounding this. Positive ions or negatively charged electrons ionized from the opening of the housing 9b according to the polarity of the high voltage power supply 11,
Negative ions are released. The grid electrode 10 is made of a metal mesh and controls the flow of generated ions with respect to the corona charger 9. In this embodiment, the grid electrode 10 is connected to the DC high-voltage power supply 12. Alternatively, or in some cases, an AC high voltage may be used.
【００４３】Ｔは現像工程によって感光体１表面に付着
したトナー（本例においてトナーＴは負帯電トナーとし
ている）であり、その表面電位は上述の式（１５）また
は式（１６）によって与えられる電位Ｖｒを有してい
る。なお、１ｗはトナーＴが付着しない背景部電位を帯
びた領域を示しており、感光体自身の暗減衰により表面
電位は時間経過とともに低下するが、その減衰量は微量
であるため、本例では背景部電位は略初期電位（Ｖ0）
とみなすこととする。T is the toner adhered to the surface of the photoreceptor 1 in the developing step (the toner T is a negatively charged toner in this embodiment), and its surface potential is given by the above formula (15) or (16). It has the potential Vr. Note that 1 w indicates a background-potential region where the toner T does not adhere. The surface potential decreases with time due to dark decay of the photoreceptor itself. The background potential is approximately the initial potential (V 0 )
Shall be considered.
【００４４】以下、図１および図２の構成において、感
光体１がマイナス帯電による反転現像方式を採用した場
合を例示し、イオン運動と各電位の変化の様子を詳細に
説明する。Hereinafter, an example in which the photoreceptor 1 adopts the reversal development system by negative charging in the configuration of FIGS. 1 and 2 will be described in detail, and the state of the ion motion and the change of each potential will be described in detail.
【００４５】感光体１をマイナス帯電させ、反転現像方
式によってトナー像を得る場合、背景部（初期帯電）電
位Ｖ0と、現像バイアス電位Ｖｂと、静電潜像の画像部
（光照射部）電位Ｖａと、電位Ｖａに付着したトナーの
表面電位Ｖｒと、転写電位Ｖｔとの関係は、図３(ａ)の
ようになる。When the photosensitive member 1 is negatively charged and a toner image is obtained by the reversal developing method, the background portion (initial charging) potential V 0 , the developing bias potential Vb, and the image portion of the electrostatic latent image (light irradiation portion) FIG. 3A shows the relationship between the potential Va, the surface potential Vr of the toner attached to the potential Va, and the transfer potential Vt.
【００４６】図３(ａ）の電位関係において、コロナワ
イヤ用電源１１として画像部電位Ｖａと逆極性の正帯電
直流高電圧電源を用いた場合を図３(ｂ１)に示す。横軸
位置ｙ１は感光体表面の位置であり、ｙ１＋Ｌはグリッ
ド電極の位置である。実際は画像部電位領域にはトナー
が付着しているため、画像部電位領域Ｖａ、背景部電位
領域Ｖ0とトナー像の表面電位Ｖｒ位置では、トナー層
の厚さだけ物理的な表面位置は異なるが、感光体および
グリッド電極間の間隔をＬとすると、その差は極めて小
さいため、ここではトナー層の厚さは無視し、ｙ１で記
すことにする。FIG. 3 (b1) shows a case where a positively charged DC high voltage power supply having a polarity opposite to the image section potential Va is used as the corona wire power supply 11 in the potential relationship shown in FIG. 3 (a). The horizontal axis position y1 is the position of the photoconductor surface, and y1 + L is the position of the grid electrode. Actually, since toner adheres to the image portion potential region, the physical surface position differs by the thickness of the toner layer between the image portion potential region Va, the background portion potential region V 0 and the surface potential Vr of the toner image. However, assuming that the distance between the photoconductor and the grid electrode is L, the difference is extremely small. Therefore, the thickness of the toner layer is ignored here and is denoted by y1.
【００４７】今、コロナワイヤ用電源１１に正の直流高
電圧を印加すると、コロナワイヤ周辺の空気はイオン化
し、コロナワイヤから周囲に正帯電イオンが降り注ぐこ
とになる。この時、グリッド電極１０に画像部電位Ｖａ
（Ｖａ≦０）と同極性の直流負電圧Ｖｇを印加すると、
グリッド電極１０と感光体１との間には図３(ｂ１)に示
されるように、感光体上のトナー像表面電位の部分では
電位差Ｖｇ−Ｖｒ、背景部電位の部分ではＶｇ−Ｖ0の
電位差が発生する。When a high positive direct current voltage is applied to the corona wire power supply 11, the air around the corona wire is ionized, and positively charged ions fall from the corona wire to the surroundings. At this time, the image portion potential Va is applied to the grid electrode 10.
When a DC negative voltage Vg having the same polarity as (Va ≦ 0) is applied,
As is shown in FIG. 3 (b1) between the grid electrode 10 and the photosensitive member 1, the potential difference Vg-Vr in the portion of the toner image surface potential of the photosensitive member, the Vg-V 0 in the portion of the background portion potential A potential difference occurs.
【００４８】ここで、グリッド電圧ＶｇをＶｒ＜Ｖｇ＜
０の範囲に設定すると、正イオンは電位の低い方向へ、
即ち、図３(ｂ１)において矢印で示した方向へと移動す
る。正イオンの供給量が十分多いか、長時間この状態を
継続すると、正イオンは感光体上の負帯電状態を緩和
し、トナー像表面電位Ｖｒおよび背景部電位Ｖ0はグリ
ッド電位Ｖｇに一致するようになり、両電位とも絶対値
が低下することになる。Here, the grid voltage Vg is set to Vr <Vg <
When set in the range of 0, positive ions move in the direction of lower potential,
That is, it moves in the direction indicated by the arrow in FIG. Or the supply amount of positive ions is sufficiently large, a long time to continue this state, the positive ions relaxes negatively charged state on the photosensitive member, the toner image surface potential Vr and the background portion potential V 0 which corresponds to the grid potential Vg As a result, the absolute values of both potentials decrease.
【００４９】従って、現像後転写前のグリッド電圧Ｖｇ
制御の正コロナ帯電により、トナー像表面電位は電位差
Ｖｇ−Ｖｒ、また背景部電位は電位差Ｖｇ−Ｖ0の電位
が除電される。この結果、正帯電の転写電位Ｖｔとトナ
ー像表面電位Ｖｒとの間の電位差（Ｖｔ−Ｖｒ）は、
(Ｖｔ−Ｖｇ）へと、また転写電位Ｖｔと背景部電位Ｖ0
との電位差（Ｖｔ−Ｖ0）は、（Ｖｔ−Ｖｇ）へと低減
されることになる。このため、用紙および感光体上の背
景部領域間で作られる間隙空気層の電位差ΔＶｗは低下
し、パッシェン放電条件に到らず、トナー像の周縁輪郭
部分の転写による印字ボケを抑制することが可能にな
る。Therefore, the grid voltage Vg after development and before transfer is obtained.
The positive corona charging control, the toner image surface potential difference Vg-Vr The background portion potential, the potential of the potential difference Vg-V 0 is neutralization. As a result, the potential difference (Vt−Vr) between the positively charged transfer potential Vt and the toner image surface potential Vr is
(Vt−Vg), the transfer potential Vt and the background portion potential V 0
, The potential difference (Vt−V 0 ) is reduced to (Vt−Vg). For this reason, the potential difference ΔVw of the gap air layer formed between the paper and the background area on the photoreceptor is reduced, and the printing blur due to the transfer of the peripheral contour portion of the toner image is suppressed without reaching the Paschen discharge condition. Will be possible.
【００５０】図３(ｂ３)は、グリッド電位Ｖｇが図３
(ｂ１)と同様、画像部電位Ｖａに対し同極性のＶｒ＜Ｖ
ｇ＜０の範囲にある時、電源１１を画像部電位Ｖａに対
し同極性の負に選択した場合を示している。FIG. 3 (b3) shows that the grid potential Vg is
As in (b1), Vr <V having the same polarity with respect to the image portion potential Va.
This shows a case where the power supply 11 is selected to be negative with the same polarity with respect to the image portion potential Va when g <0.
【００５１】負帯電の高圧電源１１から負イオンあるい
は電子が放出され、感光体とグリッド電極間に存在した
時の状況を示している。負イオンや電子は正イオンとは
逆に、電位の高い方向に向うため、感光体とグリッド電
極間に負イオンや電子が存在したとしても、グリッド電
極に集積され、感光体上の画像部および背景部の電位は
直接影響を受けない。この時、感光体上のトナー像、あ
るいは背景部から負イオンや電子がグリッド電極に飛び
移り、捕獲されることは否定はできないが、ここで選択
している数百ボルト程度のグリッド電圧ではその可能性
は極めて低く、現像後転写前除電効果は極めて低いもの
と考えられる。This shows a situation in which negative ions or electrons are emitted from the negatively charged high-voltage power supply 11 and exist between the photosensitive member and the grid electrode. Negative ions and electrons are opposite to positive ions in the direction of higher potential, so even if negative ions or electrons exist between the photoconductor and the grid electrode, they are accumulated on the grid electrode, and the image area on the photoconductor and The background potential is not directly affected. At this time, it cannot be denied that negative ions or electrons jump from the toner image on the photoreceptor or the background to the grid electrode and are captured, but with the grid voltage of about several hundred volts selected here, the The possibility is extremely low, and the charge removal effect after development and before transfer is considered to be extremely low.
【００５２】しかし、図３(ｂ１)と図３(ｂ３)の組み合
わせは、グリッド電極に画像部電位Ｖａと同極性の直流
負電位Ｖｇを、Ｖｒ＜Ｖｇ＜０の条件で印加し、電源１
１に交流高電圧を印加した時、各半周期のピーク電圧状
況を表しているものとみなすことができる。すなわち、
図３(ｂ１)で与えた除電効果は図３(ｂ３)を考慮する
と、電源１１の交流高電圧電源の印加状態においても同
等の作用を為すことが判るが、高速印字においては注意
が必要である。However, in the combination of FIG. 3B1 and FIG. 3B3, the DC negative potential Vg having the same polarity as the image portion potential Va is applied to the grid electrode under the condition of Vr <Vg <0, and the power supply 1
1 can be regarded as representing a peak voltage situation in each half cycle when an AC high voltage is applied. That is,
Considering FIG. 3 (b3), it can be seen that the static elimination effect given in FIG. 3 (b1) has the same effect even when the AC high-voltage power supply of the power supply 11 is applied, but care must be taken in high-speed printing. is there.
【００５３】それは、感光体の走行速度をｖr、交流高
電圧コロナ帯電器の実効開口幅をｗで表すと、交流電源
の交流周波数ｆは、ｆ≧ｖr／ｗでなければならないと
言うことである。これ以下の周波数では感光体がコロナ
帯電器領域を走行中、例えば、図３(ｂ３)で示される負
帯電コロナの状態のみが印加され、除電効果を示す正帯
電コロナが印加されずに、現像後転写前の高電圧コロナ
帯電領域を通過してしまう為である。That is, if the traveling speed of the photoreceptor is represented by vr and the effective opening width of the AC high voltage corona charger is represented by w, the AC frequency f of the AC power supply must be f ≧ vr / w. is there. At a frequency lower than this, while the photoreceptor is traveling in the corona charger region, for example, only the state of the negatively charged corona shown in FIG. 3 (b3) is applied, and the positively charged corona showing the static elimination effect is not applied. This is because it passes through the high voltage corona charging area before the post-transfer.
【００５４】図３(ｂ２)は電源１１が正帯電高電圧電源
であり、正イオンがグリッド電極と感光体の間の空間に
存在し、直流グリッド電極電圧としてＶ0＜Ｖｇ≦Ｖｒ
＜０で、特にＶ0＜Ｖｒ＝Ｖｇに設定した時の状況を示
している。図３(ｂ１)および図３(ｂ３)の説明から明ら
かなように、正イオンはＶｇ＝Ｖｒであるから、トナー
像表面電位部分には引き付けられず、正帯電高電圧コロ
ナの影響を受けないことが判る。一方、背景部電位にお
いては、Ｖ0＜Ｖｇ＜０の関係にあるため、正イオン
は、背景部電位Ｖ0部分にのみ選択的に引き付けられ、
集積し、結果として電位Ｖ0からＶｇ（＝Ｖｒ）へと、
絶対値の低下を生じさせることになる。このため、トナ
ー像表面電位Ｖｒは不変で、背景部電位Ｖ0のみが選択
的に除電されることになる。FIG. 3 (b2) shows that the power supply 11 is a positively charged high voltage power supply, positive ions are present in the space between the grid electrode and the photosensitive member, and V 0 <Vg ≦ Vr as the DC grid electrode voltage.
<0, especially when V 0 <Vr = Vg. As is clear from the description of FIGS. 3B1 and 3B3, since the positive ions are Vg = Vr, they are not attracted to the toner image surface potential portion and are not affected by the positively charged high voltage corona. You can see that. On the other hand, in the background potential, the relationship V 0 <Vg <0 holds, so that positive ions are selectively attracted only to the background potential V 0 ,
Integration, and as a result, from potential V 0 to Vg (= Vr),
This will cause a decrease in the absolute value. For this reason, the toner image surface potential Vr does not change, and only the background portion potential V 0 is selectively discharged.
【００５５】先に、パッシェン放電の発生領域は、感光
体の背景部電位Ｖ0が関与していること、そして、パッ
シェン放電抑止には電位Ｖ0の絶対値を選択的に低下さ
せるとよいことを述べたが、正帯電高電圧コロナ帯電器
を利用し、設置されているグリッド電極の直流電圧Ｖｇ
の範囲をＶ0＜Ｖｒ≦Ｖｇ＜０に設定することにより、
これが実現可能であることが確認されたことになる。First, the region where the Paschen discharge occurs is related to the background potential V 0 of the photoreceptor, and the absolute value of the potential V 0 should be selectively reduced to suppress the Paschen discharge. However, the DC voltage Vg of the installed grid electrode using a positively charged high voltage corona charger is described.
By setting the range of V 0 <Vr ≦ Vg <0,
This confirms that this is feasible.
【００５６】図３(ｂ４)は、電源１１が負帯電高電圧電
源であり、負イオンや電子がグリッド電極と感光体の間
の空間に存在し、直流グリッド電極電圧としてＶ0＜Ｖ
ｇ≦Ｖｒ＜０、特にＶ0＜Ｖｒ＝Ｖｇに設定した時の状
況を示している。図３(ｂ３)と同様に、図３(ｂ２)と図
３(ｂ４)の組み合わせはグリッド電極に直流負電位Ｖｇ
をＶ0＜Ｖｒ＝Ｖｇ＜０の条件で印加し、電源１１とし
て交流高電圧を用いた時、各半周期のピーク電圧の状況
を表している。即ち、図３(ｂ２)で与えた背景部電位Ｖ
0の選択的除電効果は、図３(ｂ４)を考慮すると電源１
１の交流高電圧印加においても同等に作用する。以上述
べたように、図３(ｂ１)、図３(ｂ３)は現像後転写前に
おけるトナー像表面電位Ｖｒと背景部電位Ｖ0の全域除
電に相当する。また、図３(ｂ２)、図３(ｂ４)は背景部
電位Ｖ0のみの選択除電となる。FIG. 3 (b4) shows that the power supply 11 is a negatively charged high voltage power supply, negative ions and electrons are present in the space between the grid electrode and the photosensitive member, and V 0 <V as the DC grid electrode voltage.
This shows a situation when g ≦ Vr <0, particularly V 0 <Vr = Vg. 3 (b3), the combination of FIG. 3 (b2) and FIG. 3 (b4) shows that the grid electrode has a DC negative potential Vg.
Is applied under the condition of V 0 <Vr = Vg <0, and the peak voltage in each half cycle is shown when an AC high voltage is used as the power supply 11. That is, the background portion potential V given in FIG.
Considering FIG. 3 (b4), the selective static elimination effect of 0
The same effect is obtained even when the AC high voltage is applied. As described above, FIG. 3 (b1), Figure 3 (b3) corresponds to a whole neutralization of the toner image surface potential Vr and the background portion potential V 0 which before transfer after development. Further, FIG. 3 (b2), FIG. 3 (b4) is the selective neutralization of only the background portion potential V 0.
【００５７】パッシェン放電防止に関して言えば、全域
除電が効果的ではあるが、この時、除電効果が強ければ
静電転写効率を低下させることになる。従って、現像効
率が高く、現像バイアス電位とトナー像表面電位とがＶ
ｂ≒Ｖｒの時には、Ｖｇ≒Ｖｂ／２程度に設定し、全域
除電が望ましい。With respect to the prevention of Paschen discharge, static electricity removal is effective in the whole area, but at this time, if the static electricity removing effect is strong, the electrostatic transfer efficiency is reduced. Therefore, the developing efficiency is high, and the developing bias potential and the toner image surface potential are V
When b ≒ Vr, it is desirable to set about Vg 程度 Vb / 2, and to perform static elimination over the entire area.
【００５８】一方、現像効率が低く、Ｖａ≒Ｖｒの時に
は、転写効率を保持するためＶｇ≒Ｖｒとするとよいこ
とがわかる。すなわち、図３(ｂ１)、図３(ｂ３)の条
件、あるいは、図３(ｂ２)、図３(ｂ４)の条件の選択に
は、現像後のトナー像表面電位Ｖｒの大きさから判断可
能であることがわかる。On the other hand, when the developing efficiency is low and Va ≒ Vr, Vg よ い Vr should be satisfied to maintain the transfer efficiency. That is, the condition of FIG. 3 (b1) and FIG. 3 (b3) or the condition of FIG. 3 (b2) and FIG. 3 (b4) can be selected from the magnitude of the toner image surface potential Vr after development. It can be seen that it is.
【００５９】この観点から、図１に示したように現像後
のトナー像表面電位Ｖｒを、電位センサ８によって印字
前後あるいは印字中に常時測定し、その測定値に基づ
き、予め設定されたグリッド電位Ｖｇを選択し、コロナ
ワイヤへの印加電圧およびグリッド電圧を制御すること
により、高画質、高精細画像を得ることが可能になる。From this point of view, as shown in FIG. 1, the toner image surface potential Vr after development is always measured by a potential sensor 8 before or after printing or during printing, and based on the measured value, a grid potential set in advance is set. By selecting Vg and controlling the voltage applied to the corona wire and the grid voltage, it is possible to obtain high-quality and high-definition images.
【００６０】なお、以上の説明ではマイナス帯電による
反転現像方式を採用した場合に基づき説明したが、本発
明はこれに限らず、図４に示すように感光体のプラス帯
電に反転現像方式を採用した場合、この時、画像部のト
ナー粒子はプラス帯電にあり、コロナ帯電器は静電潜像
と逆極性のマイナスイオンを供給し、グリッド電位は選
択された範囲のプラス電位に対し、同等の作用効果が得
られることになる。更に、図５に示すように感光体のマ
イナス帯電に正規現像方式を採用した場合、あるいは図
６に示すように感光体のプラス帯電に正規現像方式を採
用した場合のそれぞれについても同等の作用効果が得ら
れるものであることは言うまでもない。In the above description, the description has been made based on the case where the reversal development system using negative charging is employed. However, the present invention is not limited to this, and the reversal development system is employed for positive charging of the photosensitive member as shown in FIG. In this case, at this time, the toner particles in the image area are positively charged, the corona charger supplies negative ions of the opposite polarity to the electrostatic latent image, and the grid potential is equivalent to the plus potential in the selected range. The effect will be obtained. Further, the same operation and effect can be obtained in the case where the regular development system is adopted for the negative charging of the photoconductor as shown in FIG. 5 or the case where the regular development system is adopted for the positive charging of the photoconductor as shown in FIG. Needless to say, this is what can be obtained.
【００６１】先にも述べたように、正規現像方式におい
て各電位の関係は、０≦｜Ｖａ｜＜｜Ｖｂ｜＜｜Ｖｒ｜
＜｜Ｖ0｜が成立し、初期帯電電位Ｖ0が最終的にトナー
の付着する部分となる。As described above, the relationship between the potentials in the normal development system is as follows: 0 ≦ | Va | <| Vb | <| Vr |
<| V 0 | is satisfied, and the initial charging potential V 0 finally becomes a portion where toner adheres.
【００６２】さらに正規現像方式では、転写電圧Ｖｔと
画像部電位Ｖ0は同極性であり、光照射部Ｖａが背景部
電位となることから、｜Ｖｔ−Ｖ0｜＜｜Ｖｔ−Ｖａ｜
となり、パッシェン放電抑制のための現像後転写前の直
流高電圧コロナは、光照射部Ｖａに対する同極性イオン
の帯電による効果に変更されていることが判明する。Further, in the normal development method, the transfer voltage Vt and the image portion potential V 0 have the same polarity, and the light irradiation portion Va has the background portion potential. Therefore, | Vt−V 0 | <| Vt−Va |
It can be seen that the DC high voltage corona after development and before transfer for suppressing Paschen discharge has been changed to the effect of charging the light irradiation part Va with ions of the same polarity.
【００６３】さらにこの時、グリッド電圧Ｖｇの｜Ｖｒ
｜＜｜Ｖｇ｜＜｜Ｖ0｜条件は全領域の帯電状態、グリ
ッド電圧Ｖｇの｜Ｖａ｜＜｜Ｖｇ｜＜｜Ｖｒ｜条件はト
ナーの背景部電位領域に対する選択的帯電状態になって
いることがわかる。Further, at this time, | Vr of the grid voltage Vg
The condition of | <| Vg | <| V 0 | is a charged state of the entire region, and the condition of Va | <| Vg | <| Vr | of the grid voltage Vg is a selective charged state of the toner with respect to the background potential region. You can see that.
【００６４】なお、所定極性のイオンを供給するイオン
生成手段であるコロナ帯電器電源の交流高電圧と直流高
電圧電源の大きな相違は、交流高電圧では半周期の異極
性無効成分を含むことであり、このため、直流高電圧の
方が強力に除電あるいは帯電効果を実現することであ
る。従って、高速印刷用の静電記録装置のように感光体
が高速で走行し、生成イオンが感光体に十分供給され
ず、除電あるいは帯電効果に乏しい時にはグリッド電極
で制御された直流高電圧コロナ帯電が有益であり、低速
で微妙な調整を必要な時には、グリッド電極で制御され
た正弦波波形に限定されず、三角波等いろいろなタイプ
の波形を選定した交流高電圧コロナ帯電を利用すること
が望ましい。A major difference between the AC high voltage of the corona charger power supply, which is an ion generating means for supplying ions of a predetermined polarity, and the DC high voltage power supply is that the AC high voltage includes a half-cycle different polarity invalid component. Therefore, for this reason, a high DC voltage is to realize a stronger static elimination or charging effect. Therefore, when the photoreceptor travels at a high speed like an electrostatic recording device for high-speed printing, the generated ions are not sufficiently supplied to the photoreceptor, and when the static elimination or charging effect is poor, the direct current high voltage corona charging controlled by the grid electrode is performed. Is useful, and when slow and delicate adjustments are needed, it is desirable to use AC high voltage corona charging that selects various types of waveforms such as triangular waves, not limited to sinusoidal waveforms controlled by grid electrodes .
【００６５】[0065]
【発明の効果】以上述べたように本発明によれば、記録
媒体と静電記録体との剥離過程において発生するパッシ
ェン放電を抑止することが可能で、記録像の周縁、輪郭
部分における転写ボケ、印字乱れの発生を抑止すること
が可能な静電記録装置を提供することができる。As described above, according to the present invention, it is possible to suppress the Paschen discharge that occurs during the separation process between the recording medium and the electrostatic recording medium, and to reduce the transfer blur at the peripheral edge and the outline of the recorded image. In addition, it is possible to provide an electrostatic recording device capable of suppressing occurrence of printing disorder.
【図１】本発明の静電記録装置の概略構成図。FIG. 1 is a schematic configuration diagram of an electrostatic recording device of the present invention.
【図２】本発明の要部概念図。FIG. 2 is a conceptual diagram of a main part of the present invention.
【図３】感光体マイナス帯電による反転現像方式の場合
における各電位とイオン運動との関係を示す説明図。FIG. 3 is an explanatory diagram showing the relationship between each potential and ion motion in the case of a reversal development system using negative charging of a photoconductor.
【図４】感光体プラス帯電による反転現像方式の場合に
おける各電位とイオン運動との関係を示す説明図。FIG. 4 is an explanatory diagram showing the relationship between each potential and ion motion in the case of a reversal development system using positive charging of a photoconductor.
【図５】感光体マイナス帯電による正規現像方式の場合
における各電位とイオン運動との関係を示す説明図。FIG. 5 is an explanatory diagram showing the relationship between each potential and ion motion in the case of a normal development method using negative charging of a photoconductor.
【図６】感光体プラス帯電による正規現像方式の場合に
おける各電位とイオン運動との関係を示す説明図。FIG. 6 is an explanatory diagram showing the relationship between each potential and ion motion in the case of a normal development system using a photosensitive member plus charging.
１…静電記録体（感光体）、９…イオン生成手段（コロ
ナ帯電器）、１０…グリッド電極、１１,１２…電源。DESCRIPTION OF SYMBOLS 1 ... Electrostatic recording body (photoreceptor), 9 ... Ion generating means (Corona charger), 10 ... Grid electrode, 11, 12 ... Power supply.
Claims (12)
を有する静電潜像を形成する静電潜像形成手段と、 前記静電潜像を保持した静電記録体に記録剤を供給し、
前記画像部電位の領域を記録像として可視化させる現像
手段と、 前記静電記録体上に形成された記録像を記録媒体に転写
させる転写手段とを備えた静電記録装置において、 前記現像手段と前記転写手段との間に配置され、前記静
電記録体に向けて所定極性のイオンを供給するイオン生
成手段と、 前記静電記録体表面と前記イオン生成手段との間に配置
され、前記画像部電位と背景部電位との間の電位に設定
されたグリッド電位を有し、前記記録像の表面電位およ
び前記背景部電位の内、少なくとも前記背景部電位を前
記グリッド電位に同等となるように前記イオンの運動を
制御するグリッド電極手段とを有することを特徴とする
静電記録装置。1. An electrostatic latent image forming means for forming an electrostatic latent image having an image portion potential and a background portion potential on an electrostatic recording medium, and recording on the electrostatic recording medium holding the electrostatic latent image Supply the agent,
A developing unit for visualizing the area of the image portion potential as a recording image; and an electrostatic recording apparatus including a transfer unit for transferring a recording image formed on the electrostatic recording medium to a recording medium, wherein the developing unit An ion generating unit disposed between the transfer unit and supplying ions of a predetermined polarity toward the electrostatic recording medium; and an ion generating unit disposed between the surface of the electrostatic recording medium and the ion generating unit, and Having a grid potential set to a potential between the partial potential and the background potential, so that at least the background potential is equal to the grid potential among the surface potential of the recorded image and the background potential. A grid electrode means for controlling the movement of the ions.
を有する静電潜像を形成する静電潜像形成手段と、 前記静電潜像を保持した静電記録体に記録剤を供給し、
前記画像部電位の領域を記録像として可視化させる現像
手段と、 前記静電記録体上に形成された記録像を記録媒体に転写
させる転写手段とを備えた静電記録装置において、 前記現像手段と前記転写手段との間に配置され、前記静
電潜像と逆極性のイオンを前記静電記録体に向けて供給
するイオン生成手段と、 前記静電記録体表面と前記イオン生成手段との間に配置
され、前記画像部電位と背景部電位との間の電位に設定
されたグリッド電位を有し、前記記録像の表面電位およ
び前記背景部電位の内、少なくとも前記背景部電位を前
記グリッド電位に同等となるように前記イオンの運動を
制御するグリッド電極手段とを有するとともに、 前記記録像の表面電位と前記グリッド電位は、前記記録
像の表面電位をＶｒ、前記グリッド電位をＶｇとしたと
き、０＜｜Ｖｇ｜≦｜Ｖｒ｜の条件を満たすように設定
されていることを特徴とする静電記録装置。2. An electrostatic latent image forming means for forming an electrostatic latent image having an image portion potential and a background portion potential on an electrostatic recording medium, and recording on the electrostatic recording medium holding the electrostatic latent image Supply the agent,
A developing unit for visualizing the area of the image portion potential as a recording image; and an electrostatic recording apparatus including a transfer unit for transferring a recording image formed on the electrostatic recording medium to a recording medium, wherein the developing unit An ion generating unit disposed between the transfer unit and supplying ions having a polarity opposite to that of the electrostatic latent image toward the electrostatic recording medium; and between the surface of the electrostatic recording medium and the ion generating unit. And a grid potential set to a potential between the image portion potential and the background portion potential, wherein at least the background portion potential of the surface potential of the recorded image and the background portion potential is the grid potential. Grid electrode means for controlling the movement of the ions so as to be equivalent to the surface potential of the recorded image and the grid potential, wherein the surface potential of the recorded image is Vr, and the grid potential is Vg. An electrostatic recording apparatus is set so as to satisfy the following condition: 0 <| Vg | ≦ | Vr |
を有する静電潜像を形成する静電潜像形成手段と、 前記静電潜像を保持した静電記録体に記録剤を供給し、
前記画像部電位の領域を記録像として可視化させる現像
手段と、 前記静電記録体上に形成された記録像を記録媒体に転写
させる転写手段とを備えた静電記録装置において、 前記現像手段と前記転写手段との間に配置され、前記静
電潜像と同極性のイオンを前記静電記録体に向けて供給
するイオン生成手段と、 前記静電記録体表面と前記イオン生成手段との間に配置
され、前記画像部電位と背景部電位との間の電位に設定
されたグリッド電位を有し、前記記録像の表面電位およ
び前記背景部電位の内、少なくとも前記背景部電位を前
記グリッド電位に同等となるように前記イオンの運動を
制御するグリッド電極手段とを有するとともに、 前記記録像の表面電位と前記グリッド電位は、前記記録
像の表面電位をＶｒ、前記グリッド電位をＶｇとしたと
き、０＜｜Ｖｇ｜≦｜Ｖｒ｜の条件を満たすように設定
されていることを特徴とする静電記録装置。3. An electrostatic latent image forming means for forming an electrostatic latent image having an image portion potential and a background portion potential on an electrostatic recording medium, and recording on the electrostatic recording medium holding the electrostatic latent image. Supply the agent,
A developing unit for visualizing the area of the image portion potential as a recording image; and an electrostatic recording apparatus including a transfer unit for transferring a recording image formed on the electrostatic recording medium to a recording medium, wherein the developing unit Ion generating means disposed between the transfer means and supplying ions of the same polarity as the electrostatic latent image toward the electrostatic recording medium; and between the surface of the electrostatic recording medium and the ion generating means. And a grid potential set to a potential between the image portion potential and the background portion potential, wherein at least the background portion potential of the surface potential of the recorded image and the background portion potential is the grid potential. Grid electrode means for controlling the movement of the ions so as to be equivalent to the surface potential of the recorded image and the grid potential, wherein the surface potential of the recorded image is Vr, and the grid potential is Vg. An electrostatic recording apparatus is set so as to satisfy the following condition: 0 <| Vg | ≦ | Vr |
を有する静電潜像を形成する静電潜像形成手段と、 前記静電潜像を保持した静電記録体に記録剤を供給し、
前記画像部電位の領域を記録像として可視化させる現像
手段と、 前記静電記録体上に形成された記録像を記録媒体に転写
させる転写手段とを備えた静電記録装置において、 前記現像手段と前記転写手段との間に配置され、前記静
電潜像と逆極性のイオンを前記静電記録体に向けて供給
するイオン生成手段と、 前記静電記録体表面と前記イオン生成手段との間に配置
され、前記画像部電位と背景部電位との間の電位に設定
されたグリッド電位を有し、前記記録像の表面電位およ
び前記背景部電位の内、少なくとも前記背景部電位を前
記グリッド電位に同等となるように前記イオンの運動を
制御するグリッド電極手段とを有するとともに、 前記記録像の表面電位と前記グリッド電位は、前記記録
像の表面電位をＶｒ、前記グリッド電位をＶｇとしたと
き、｜Ｖｒ｜＜｜Ｖｇ｜の条件を満たすように設定され
ていることを特徴とする静電記録装置。4. An electrostatic latent image forming means for forming an electrostatic latent image having an image portion potential and a background portion potential on an electrostatic recording medium, and recording on the electrostatic recording medium holding the electrostatic latent image. Supply the agent,
A developing unit for visualizing the area of the image portion potential as a recording image; and an electrostatic recording apparatus including a transfer unit for transferring a recording image formed on the electrostatic recording medium to a recording medium, wherein the developing unit An ion generating unit disposed between the transfer unit and supplying ions having a polarity opposite to that of the electrostatic latent image toward the electrostatic recording medium; and between the surface of the electrostatic recording medium and the ion generating unit. And a grid potential set to a potential between the image portion potential and the background portion potential, wherein at least the background portion potential of the surface potential of the recorded image and the background portion potential is the grid potential. Grid electrode means for controlling the movement of the ions so as to be equivalent to the surface potential of the recorded image and the grid potential, wherein the surface potential of the recorded image is Vr, and the grid potential is Vg. The electrostatic recording apparatus is set to satisfy | Vr | <| Vg |
を有する静電潜像を形成する静電潜像形成手段と、 前記静電潜像を保持した静電記録体に記録剤を供給し、
前記画像部電位の領域を記録像として可視化させる現像
手段と、 前記静電記録体上に形成された記録像を記録媒体に転写
させる転写手段とを備えた静電記録装置において、 前記現像手段と前記転写手段との間に配置され、前記静
電潜像と同極性のイオンを前記静電記録体に向けて供給
するイオン生成手段と、 前記静電記録体表面と前記イオン生成手段との間に配置
され、前記画像部電位と背景部電位との間の電位に設定
されたグリッド電位を有し、前記記録像の表面電位およ
び前記背景部電位の内、少なくとも前記背景部電位を前
記グリッド電位に同等となるように前記イオンの運動を
制御するグリッド電極手段とを有するとともに、 前記記録像の表面電位と前記グリッド電位は、前記記録
像の表面電位をＶｒ、前記グリッド電位をＶｇとしたと
き、｜Ｖｒ｜＜｜Ｖｇ｜の条件を満たすように設定され
ていることを特徴とする静電記録装置。5. An electrostatic latent image forming means for forming an electrostatic latent image having an image section potential and a background section potential on an electrostatic recording medium, and recording on the electrostatic recording medium holding the electrostatic latent image. Supply the agent,
A developing unit for visualizing the area of the image portion potential as a recording image; and an electrostatic recording apparatus including a transfer unit for transferring a recording image formed on the electrostatic recording medium to a recording medium, wherein the developing unit Ion generating means disposed between the transfer means and supplying ions of the same polarity as the electrostatic latent image toward the electrostatic recording medium; and between the surface of the electrostatic recording medium and the ion generating means. And a grid potential set to a potential between the image portion potential and the background portion potential, wherein at least the background portion potential of the surface potential of the recorded image and the background portion potential is the grid potential. Grid electrode means for controlling the movement of the ions so as to be equivalent to the surface potential of the recorded image and the grid potential, wherein the surface potential of the recorded image is Vr, and the grid potential is Vg. The electrostatic recording apparatus is set to satisfy | Vr | <| Vg |
ことを特徴とする請求項１〜５のいずれかの項に記載の
静電記録装置。6. An electrostatic recording apparatus according to claim 1, wherein a DC voltage is applied to said ion generating means.
ことを特徴とする請求項１〜５のいずれかの項に記載の
静電記録装置。7. An electrostatic recording apparatus according to claim 1, wherein an AC voltage is applied to said ion generating means.
た電圧に印加したことを特徴とする請求項１〜５のいず
れかの項に記載の静電記録装置。8. An electrostatic recording apparatus according to claim 1, wherein a voltage obtained by superimposing a direct current and an alternating current is applied to said ion generating means.
たことを特徴とする請求項１〜５のいずれかの項に記載
の静電記録装置。9. An electrostatic recording apparatus according to claim 1, wherein a DC voltage is applied to said grid electrode means.
電圧を重畳した電圧、または交流電圧を印加したことを
特徴とする請求項１〜５のいずれかの項に記載の静電記
録装置。10. An electrostatic recording apparatus according to claim 1, wherein a voltage obtained by superimposing an AC voltage on a DC voltage or an AC voltage is applied to said grid electrode means.
オン生成手段のイオン供給部の幅をｗ、前記イオン生成
手段に接続された電源の交流周波数をｆとしたとき、ｆ
≧ｖ／ｗの関係を満たすことを特徴とする請求項１〜１
０のいずれかの項に記載の静電記録装置。11. When the traveling speed of the electrostatic recording medium is v, the width of the ion supply unit of the ion generating means is w, and the AC frequency of a power supply connected to the ion generating means is f, f
2. The relationship of ≧ v / w is satisfied.
0. The electrostatic recording apparatus according to any one of the above items.
表面電位を検出する検出手段と、前記検出手段の出力に
基づき、前記イオン生成手段および前記グリッド電極手
段の少なくとも一方の電圧値を制御する制御手段とを備
えたことを特徴とする請求項１〜１０のいずれかの項に
記載の静電記録装置。12. A detecting means for detecting a surface potential of a recorded image formed on said electrostatic recording medium, and a voltage value of at least one of said ion generating means and said grid electrode means based on an output of said detecting means. The electrostatic recording device according to claim 1, further comprising a control unit configured to control the electrostatic recording device.
Priority Applications (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2000049070A JP2001235947A (en) | 2000-02-25 | 2000-02-25 | Electrostatic recorder |
| US09/760,657 US20010010768A1 (en) | 2000-01-21 | 2001-01-17 | Electrostatic recording method and electrostatic recording apparatus |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2000049070A JP2001235947A (en) | 2000-02-25 | 2000-02-25 | Electrostatic recorder |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JP2001235947A true JP2001235947A (en) | 2001-08-31 |
Family
ID=18571056
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP2000049070A Pending JP2001235947A (en) | 2000-01-21 | 2000-02-25 | Electrostatic recorder |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP2001235947A (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2006292938A (en) * | 2005-04-08 | 2006-10-26 | Konica Minolta Business Technologies Inc | Color image forming apparatus |
| US7251442B2 (en) | 2004-09-08 | 2007-07-31 | Konica Minolta Business Technologies, Inc. | Color image forming apparatus having advanced transfer system |
-
2000
- 2000-02-25 JP JP2000049070A patent/JP2001235947A/en active Pending
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US7251442B2 (en) | 2004-09-08 | 2007-07-31 | Konica Minolta Business Technologies, Inc. | Color image forming apparatus having advanced transfer system |
| JP2006292938A (en) * | 2005-04-08 | 2006-10-26 | Konica Minolta Business Technologies Inc | Color image forming apparatus |
| JP4613672B2 (en) * | 2005-04-08 | 2011-01-19 | コニカミノルタビジネステクノロジーズ株式会社 | Color image forming apparatus |
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