JPH06258917A - Electrostatic charger - Google Patents
Electrostatic chargerInfo
- Publication number
- JPH06258917A JPH06258917A JP5043862A JP4386293A JPH06258917A JP H06258917 A JPH06258917 A JP H06258917A JP 5043862 A JP5043862 A JP 5043862A JP 4386293 A JP4386293 A JP 4386293A JP H06258917 A JPH06258917 A JP H06258917A
- Authority
- JP
- Japan
- Prior art keywords
- magnetic powder
- image forming
- charging
- forming body
- magnetic
- 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.)
- Pending
Links
Classifications
-
- G—PHYSICS
- G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
- G03G—ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY
- G03G2215/00—Apparatus for electrophotographic processes
- G03G2215/02—Arrangements for laying down a uniform charge
- G03G2215/021—Arrangements for laying down a uniform charge by contact, friction or induction
- G03G2215/023—Arrangements for laying down a uniform charge by contact, friction or induction using a laterally vibrating brush
Landscapes
- Electrostatic Charge, Transfer And Separation In Electrography (AREA)
Abstract
Description
【０００１】[0001]
【産業上の利用分野】本発明は、電子写真複写機等の画
像形成装置において、像形成体を一様に帯電させる磁気
ブラシ或はブラシ状部材等を用いた接触帯電装置に関す
る。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a contact charging device in an image forming apparatus such as an electrophotographic copying machine which uses a magnetic brush or a brush-like member for uniformly charging an image forming body.
【０００２】[0002]
【従来の技術】図３は接触帯電装置の一例である磁気ブ
ラシ帯電装置の概略構成を示す図である。2. Description of the Related Art FIG. 3 is a diagram showing a schematic structure of a magnetic brush charging device which is an example of a contact charging device.
【０００３】磁気ブラシ帯電装置20は、筐体25の開口を
像形成体10に対向するように配置し、その中に磁性粉体
担体23、磁性粉体21等を内包し、磁性粉体担体23の搬送
と規制部材26上により、磁性粉体担体23上に磁性粉体21
による磁気ブラシを形成し、振動電界下で像形成体10の
感光層12を摺擦して帯電を行うものである。The magnetic brush charging device 20 is arranged such that the opening of the housing 25 faces the image forming body 10, and the magnetic powder carrier 23, the magnetic powder 21 and the like are included therein, and the magnetic powder carrier The magnetic powder 21 is placed on the magnetic powder carrier 23 by the transport of the 23 and the regulating member 26.
To form a magnetic brush, and rub the photosensitive layer 12 of the image forming body 10 under an oscillating electric field for charging.
【０００４】撹拌部材27は筐体25内に装填した磁性粉体
21を撹拌することにり磁性粉体の停滞や溜りを防止する
ものである。像形成体10は導電性基体11の表面を覆うＯ
ＰＣ感光体層12からなるドラムである。The stirring member 27 is a magnetic powder loaded in the housing 25.
The stirring of 21 prevents the magnetic powder from stagnation and accumulation. The image forming body 10 covers the surface of the conductive substrate 11 with O
This is a drum composed of the PC photosensitive layer 12.
【０００５】磁性粉体21は導電性の磁性粒子である。The magnetic powder 21 is a conductive magnetic particle.
【０００６】磁石22は円柱状の棒にＳ極及びＮ極を図の
ように着磁してあり、磁石22はその両端部を筐体25の内
側壁に固設してある。磁性粉体担体23は非磁性金属で形
成された導電性円筒状で、その円筒内に磁石22を内包す
る。これにより、磁性粉体担体23は像形成体10と同方向
に1.2〜2.0倍の周速で回転する。磁性粉体担体23と像形
成体10との間隙は帯電電位等により異なるが、一般に0.
1〜５mm好ましくは0.3〜1.5mmに保持されている。この
間隙は帯電電圧等により異なる。The magnet 22 is magnetized with a S pole and an N pole on a cylindrical rod as shown in the figure, and both ends of the magnet 22 are fixed to the inner wall of the housing 25. The magnetic powder carrier 23 has a conductive cylindrical shape formed of a non-magnetic metal, and the magnet 22 is included in the cylinder. As a result, the magnetic powder carrier 23 rotates in the same direction as the image forming body 10 at a peripheral speed of 1.2 to 2.0 times. The gap between the magnetic powder carrier 23 and the image forming body 10 varies depending on the charging potential and the like, but is generally 0.
It is held at 1 to 5 mm, preferably 0.3 to 1.5 mm. This gap varies depending on the charging voltage and the like.
【０００７】電源24は電圧Ｖp-pが200〜3500Ｖの交流電
圧源と帯電すべき電圧と同じ値或はそれより低い例えば
−500〜−1500Ｖに設定した可変直流電圧源とを直列接
続したものと等価とみなす。直流電圧源24bの一方の出
力端子は導電性基体11に接続し、導電性基体11は接地し
てある。一方の出力端子を磁性粉体担体23に接続するこ
とになる。磁性粉体担体23に付着して搬送される磁性粉
体21層は筐体25の開口に設けた規制板26により間隙の厚
さに規制する。これにより、磁性粉体21層は磁性粉体担
体23と感光層12を接続する。これによって、電源24は磁
性粉体担体23と像形成体10の導電性基体11との0.1〜５m
m間隙に前述の電圧を印加することになり、像形成体10
に直接電荷を注入するので、低電圧でかつ、オゾンの発
生を減少し、交流成分を含むので極めて安定した均一帯
電を行うことができる。直流成分は定電圧制御をし、交
流成分Ｖp-pは定電流制御をすることになる。[0007] Power 24 to that a variable DC voltage source the voltage V pp is set to the same value or lower than eg -500-1500V voltage to be charged and the AC voltage source 200~3500V connected in series Consider equivalent. One output terminal of the DC voltage source 24b is connected to the conductive base 11, and the conductive base 11 is grounded. One of the output terminals will be connected to the magnetic powder carrier 23. The layer of the magnetic powder 21 attached to the magnetic powder carrier 23 and conveyed is regulated by the regulation plate 26 provided in the opening of the housing 25 to the thickness of the gap. As a result, the magnetic powder 21 layer connects the magnetic powder carrier 23 and the photosensitive layer 12. As a result, the power source 24 is 0.1 to 5 m between the magnetic powder carrier 23 and the conductive base 11 of the image forming body 10.
The above-mentioned voltage is applied to the m gap, and
Since the electric charge is directly injected into, the generation of ozone is reduced at a low voltage, and the AC component is included, so that extremely stable uniform charging can be performed. The DC component controls the constant voltage, and the AC component V pp controls the constant current.
【０００８】図４は接触帯電装置の他の例としてのファ
ーブラシ形式によるブラシ帯電器の概略構成を示す断面
図である。FIG. 4 is a sectional view showing a schematic structure of a fur charger type brush charger as another example of the contact charging device.
【０００９】導電性繊維を接触子として、各々機能分離
した層が積層構造をとる制止固定型の帯電器がある。こ
れは像形成体10表面から順に短繊維41、電極42、絶縁材
43、ヒータ44、クッション材45が層状に重合された構成
を持つ。像形成体表面に接触する繊維状導電子は、太さ
1.5〜10デニール、長さ1.5mm，毛ブラシ密度16000〜200
00本／cm2、繊維長方向の抵抗は約108Ωcmである。電極
材はカーボンを織り込んだ５×105ΩのＳＢＲを用い、
帯電の均一性を得るために、Ａ点に交流電圧印加し、Ｂ
点に直流電圧を印加し、電極材抵抗を通してある。ヒー
タは表層の短繊維の吸湿を防ぎ抵抗の変動を抑えるもの
である。There is a fixed-stop type charging device in which conductive fibers are used as contacts and the layers separated from each other have a laminated structure. This is a short fiber 41, an electrode 42, and an insulating material in order from the surface of the image forming body 10.
43, a heater 44, and a cushioning material 45 are layered and superposed. The thickness of the fibrous conductor that contacts the surface of the image forming body is
1.5-10 denier, length 1.5 mm, bristle brush density 16000-200
The number of fibers is 00 fibers / cm 2 , and the resistance in the fiber length direction is about 10 8 Ωcm. 5 × 10 5 Ω SBR woven with carbon is used as the electrode material,
In order to obtain uniform charging, AC voltage is applied to point A and B
A DC voltage is applied to the point and the resistance of the electrode material is passed through. The heater prevents the short fibers in the surface layer from absorbing moisture and suppresses fluctuations in resistance.
【００１０】[0010]
【発明が解決しようとする課題】しかしながら、実際に
は被帯電体たる像形成体10面を上記のような接触帯電法
により帯電処理しても像形成体10面の各部均一な帯電は
なされず、スジ状の帯電ムラを生じる。これは電圧を印
加した導電性部材とそれを接触させた像形成体10表面と
が微視的には両表面の凹凸によって理想的な密着面が得
られにくいためと考えられる。これはそしてそのスジ状
帯電ムラ状態の像形成体10面に光像露光以下の像形成プ
ロセスを適用しても出力画像はスジ状帯電ムラに対応し
たスジ状の画像となり、高品位な画像は得られない。However, in practice, even if the surface of the image forming body 10 which is the body to be charged is charged by the contact charging method as described above, the respective portions of the surface of the image forming body 10 are not uniformly charged. , And streaky uneven charging occurs. It is considered that this is because it is difficult to microscopically obtain an ideal contact surface between the conductive member to which a voltage is applied and the surface of the image forming body 10 in contact with the conductive member due to the unevenness of both surfaces. Even if the image forming process below the optical image exposure is applied to the surface of the image forming body 10 in the streak-shaped uneven charging state, the output image becomes a streak-shaped image corresponding to the streak-shaped uneven charging, and a high-quality image is obtained. I can't get it.
【００１１】又、例えば、磁性粉体から形成した磁気ブ
ラシ帯電器は、磁性粉体21からなる穂を十分に伸長した
状態で像形成体10に摺接することにより帯電する。しか
しながら、このような状態下で磁性粉体からなる穂は図
３に示すように粗であるため、像形成体表面にスジ状の
帯電ムラを引き起こす傾向にある。そこで、従来は交流
バイアスを印加するなどして帯電ムラを軽減している
が、それでも十分でない。従って、スジ状帯電ムラ状態
の像形成体10面に光像露光以下の像形成プロセスを適用
しても出力画像はスジ状のムラのある画像となり、高品
位な画像を得られないという課題がある。Further, for example, a magnetic brush charger formed of magnetic powder is charged by sliding the brush made of the magnetic powder 21 in a sufficiently extended state and slidingly contacting the image forming body 10. However, under such a condition, the ears made of magnetic powder are rough as shown in FIG. 3, and therefore tend to cause streak-shaped charging unevenness on the surface of the image forming body. Therefore, conventionally, uneven charging is reduced by applying an AC bias, but this is not sufficient. Therefore, even if the image forming process below the optical image exposure is applied to the surface of the image forming body 10 in the streaky charging uneven state, the output image becomes an image with streaky unevenness, and it is not possible to obtain a high-quality image. is there.
【００１２】本発明の第１の目的は、接触帯電装置につ
いて像形成体の移動方向にでき易い帯電ムラを解消する
ことにより被帯電面各部が均一帯電されるように改善す
ることにある。A first object of the present invention is to improve the contact charging device so that each portion of the surface to be charged is uniformly charged by eliminating charging unevenness that tends to occur in the moving direction of the image forming body.
【００１３】本発明の第２の目的は、磁気ブラシ帯電装
置について像形成体の移動方向にでき易い帯電ムラを解
消することにより被帯電面各部が均一帯電されるように
改善することにある。A second object of the present invention is to improve charging of each portion of the surface to be charged uniformly by eliminating charging unevenness that tends to occur in the moving direction of the image forming member in the magnetic brush charging device.
【００１４】[0014]
【課題を解決するための手段】上記の目的を達成する本
発明は、像形成体と帯電部材とを接触させて交流バイア
ス下で帯電を行う帯電装置であって、前記帯電部材を像
形成体の移動方向に対し、直交する方向に往復運動を行
うことを特徴とする。SUMMARY OF THE INVENTION The present invention which achieves the above object is a charging device for contacting an image forming member and a charging member to perform charging under an AC bias. The reciprocating motion is performed in a direction orthogonal to the moving direction of the.
【００１５】また本発明は、像形成体に磁気ブラシを接
触させて交流バイアス下で帯電する磁気ブラシ帯電装置
であって、磁性粉体担体と像形成体との間隙をＤS、前
記磁性粉体担体と磁気ブラシの層厚を規制する規制部材
との間隙ＤRとし、1.1≦ＤR／ＤS≦2.1であることを特
徴とする。The present invention is also a magnetic brush charging device for charging a magnetic brush to an image forming body under an AC bias, wherein a gap between the magnetic powder carrier and the image forming body is D S , and the magnetic powder is The gap D R between the body carrier and the regulating member that regulates the layer thickness of the magnetic brush is set to 1.1 ≦ D R / D S ≦ 2.1.
【００１６】[0016]
【実施例】本発明の実施例を説明する前に磁性粉体の粒
径について説明する。EXAMPLES Before describing the examples of the present invention, the particle size of the magnetic powder will be described.
【００１７】一般に磁性粉体の平均粒径（重量平均）が
大きいと、磁性粉体担体23上に形成される磁気ブラシの
穂の状態が粗いために、電界により振動を与えながら帯
電しても、磁気ブラシにムラが現れ易く、帯電ムラの問
題が起こる。この問題を解消するには、磁性粉体の平均
粒径を小さくすれば良く、実験の結果、平均粒径150μm
以下になると、実質的に前記の問題が生じる。しかし、
粒子が細かすぎると帯電時像形成体面に付着するように
なったり、飛散し易くなったりする。これらの現象は、
粒子に作用する磁界の強さ、それによる粒子の磁化の強
さにも関係するが、一般的には、粒子の平均粒径が30μ
m以下に顕著に現れるようになる。なお、磁化の強さは2
0〜200emu/gのものが好ましく用いられる。Generally, when the average particle size (weight average) of the magnetic powder is large, the state of the ears of the magnetic brush formed on the magnetic powder carrier 23 is rough, and thus the magnetic brush is charged while being vibrated by the electric field. However, unevenness is likely to appear on the magnetic brush, and the problem of uneven charging occurs. To solve this problem, the average particle size of the magnetic powder should be reduced.
In the following cases, the above problem substantially occurs. But,
If the particles are too fine, they tend to adhere to the surface of the image forming body or become easily scattered during charging. These phenomena are
Although it is related to the strength of the magnetic field acting on the particles and the strength of the magnetization of the particles due to it, in general, the average particle size of particles is 30μ.
It will appear significantly below m. The strength of magnetization is 2
Those of 0 to 200 emu / g are preferably used.
【００１８】以上から、磁性粉体の粒径は、平均粒径
（重量平均）が150μm以下、特に好ましくは100μm以下
30μm以上であることが好ましい。From the above, the average particle size (weight average) of the magnetic powder is 150 μm or less, particularly preferably 100 μm or less.
It is preferably 30 μm or more.
【００１９】このような磁性粉体は、磁性体として従来
の二成分現像剤の磁性キャリア粒子におけると同様の、
鉄、クロム、ニッケル、コバルト等の金属、あるいはそ
れらの化合物や合金、例えば四三酸化鉄、γ−酸化第二
鉄、二酸化クロム、酸化マンガン、フェライト、マンガ
ン−銅系合金といった強磁性体の粒子、又はそれら磁性
体粒子の表面をスチレン系樹脂、ビニル系樹脂、エチレ
ン系樹脂、ロジン変性樹脂、アクリル系樹脂、ポリアミ
ド樹脂、エポキシ樹脂、ポリエステル樹脂、シリコン樹
脂等の樹脂で被覆するか、あるいは、磁性体微粒子を分
散して含有した樹脂で作られた粒子を従来公知の平均粒
径選別手段で粒径選別することによって得られる。Such a magnetic powder is the same as the magnetic carrier particles of the conventional two-component developer as a magnetic material,
Metals such as iron, chromium, nickel and cobalt, or their compounds and alloys, such as particles of ferromagnetic substances such as ferric tetroxide, γ-ferric oxide, chromium dioxide, manganese oxide, ferrite and manganese-copper alloys. , Or coating the surface of these magnetic particles with a resin such as styrene resin, vinyl resin, ethylene resin, rosin-modified resin, acrylic resin, polyamide resin, epoxy resin, polyester resin, or silicone resin, or It can be obtained by selecting the particle size of particles made of a resin containing magnetic fine particles dispersed therein by a conventionally known average particle size selecting means.
【００２０】なお、磁性粉体を球状に形成することは、
磁性粉体担体に形成される粒子層が均一となり、また磁
性粉体担体に高いバイアス電圧を均一に印加することが
可能となる。即ち、磁性粉体が球形化されていること
は、一般に、磁性粉体は長軸方向に磁化吸着され易い
が、球形化によってその方向性がなくなり、従って、層
が均一に形成され、局所的に抵抗の低い領域や層厚のム
ラの発生を防止する。磁性粉体の高抵抗化と共に、従
来の粒子に見られるようなエッジ部がなくなって、エッ
ジ部への電界集中が起こらなくなり、その結果、磁性粉
体搬送担体に高いバイアス電圧を印加しても、像形成体
面に均一に放電して帯電ムラが起こらないという効果を
与える。The spherical shape of the magnetic powder is
The particle layer formed on the magnetic powder carrier becomes uniform, and a high bias voltage can be uniformly applied to the magnetic powder carrier. That is, the fact that the magnetic powder is spherical means that, in general, the magnetic powder is easily magnetized and adsorbed in the long axis direction, but due to the spherical shape, its directionality disappears, so that a layer is uniformly formed and local It also prevents the occurrence of unevenness in the region of low resistance and layer thickness. With the increase in the resistance of magnetic powder, the edge part as seen in conventional particles disappears, and electric field concentration does not occur at the edge part. As a result, even if a high bias voltage is applied to the magnetic powder carrier. The effect of uniformly discharging the surface of the image forming body to prevent uneven charging is provided.
【００２１】以上のような効果を奏する球形粒子には磁
性粉体の抵抗率が103Ω・cm以上、1012Ωcm以下特に104
Ω・cm 以上109Ω・cm 以下であるような導電性の磁性粉
体を形成したものが好ましい。この抵抗率は、粒子を0.
50cm2の断面積を有する容器に入れてタッピングした
後、詰められた粒子上に１kg/cm2の荷重をかけ、荷重と
底面電極との間に1000Ｖ／cmの電界が生ずる電圧を印加
したときの電流値を読み取ることで得られる値であり、
この抵抗率が低いと、搬送担体にバイアス電圧を印加し
た場合に、磁性粉体に電荷が注入されて、像形成体面に
磁性粉体が付着し易くなったり、或はバイアス電圧によ
る像形成体の絶縁破壊が起こり易くなったりする。ま
た、抵抗率が高いと電荷注入が行われず帯電が行われな
い。For spherical particles having the above-mentioned effects, the resistivity of the magnetic powder is 103 Ω · cm or more and 10 12 Ωcm or less, particularly 10 4
It is preferable to form conductive magnetic powder having a resistance of Ω · cm or more and 10 9 Ω · cm or less. This resistivity is 0 for particles.
After tapping in a container having a sectional area of 50 cm 2, under a load of 1 kg / cm 2 on packed particles, when a voltage is applied to the field of 1000V / cm is generated between the load and a bottom electrode Is the value obtained by reading the current value of
When the resistivity is low, when a bias voltage is applied to the carrier, electric charges are injected into the magnetic powder, and the magnetic powder easily adheres to the surface of the image forming body, or the image forming body is biased by the bias voltage. The insulation breakdown of is likely to occur. If the resistivity is high, charge injection is not performed and charging is not performed.
【００２２】更に、本発明に用いられる磁性粉体は、そ
れにより構成される磁気ブラシが振動電界により動き、
しかも外部飛散が起きないように、比重が小さく、かつ
適度の最大磁化を有するものが望ましい。具体的には真
比重が６以下で最大磁化が30〜100emu／ｇのものを用い
ると好結果が得られることが判明した。Further, in the magnetic powder used in the present invention, the magnetic brush constituted by the magnetic powder moves by an oscillating electric field,
Moreover, it is desirable that the specific gravity is small and the maximum magnetization is appropriate so that external scattering does not occur. Specifically, it was found that good results can be obtained by using a material having a true specific gravity of 6 or less and a maximum magnetization of 30 to 100 emu / g.
【００２３】以上を総合して、磁性粉体は、少なくとも
長軸と短軸の比が３倍以下であるように球形化されてお
り、針状部やエッジ部等の突起がなく、抵抗率が好まし
くは104Ω・cm以上109Ω・cm 以下であることが適正条件
である。そして、このような球状の磁性粉体は、磁性体
粒子にできるだけ球形のものを選ぶこと、磁性体微粒子
分散系の粒子では、できるだけ磁性体の微粒子を用い
て、分散樹脂粒子形成後に球形化処理を施すことによっ
て製造される。In summary, the magnetic powder is spherical so that at least the ratio of the major axis to the minor axis is 3 times or less, there are no protrusions such as needles and edges, and the resistivity is high. Is preferably 10 4 Ω · cm or more and 10 9 Ω · cm or less. In addition, such spherical magnetic powder should be selected as spherical as possible for the magnetic particles, and in the particles of the magnetic fine particle dispersion system, the fine particles of the magnetic material should be used as much as possible, and the spheroidizing treatment should be performed after forming the dispersed resin particles. It is manufactured by applying.
【００２４】また、トナーが磁気ブラシに混じると、ト
ナーは絶縁性が高いため帯電性が低下した帯電ムラを生
じる。これを防止するためにはトナーが帯電時像形成体
へ移動するようにトナーの電荷量を低くすることが必要
であり、磁性粉体にトナーを混合し、１％のトナー濃度
に調整した条件下でトナーの摩擦帯電量を帯電極性が同
じで、かつ１〜20μC/gとした場合、磁気ブラシへのト
ナーの蓄積を防止できた。このことはトナーが混入して
も帯電時像形成体へ付着するためと考えられる。トナー
の電荷量が大きいと磁性粉体から離れずらくなり、一方
小さいと電気的に像形成体に移動しずらくなることが認
められた。Further, when the toner is mixed with the magnetic brush, the toner has a high insulating property, so that the charging property is lowered and uneven charging occurs. In order to prevent this, it is necessary to reduce the charge amount of the toner so that the toner moves to the image forming body during charging, and the toner is mixed with the magnetic powder to adjust the toner concentration to 1%. When the triboelectrification amount of the toner was the same and the charging polarity was 1 to 20 μC / g, the toner could be prevented from accumulating on the magnetic brush. It is considered that this is because even if the toner is mixed, it adheres to the image forming body during charging. It was confirmed that when the charge amount of the toner is large, it becomes difficult to separate from the magnetic powder, while when it is small, it becomes difficult to electrically move to the image forming body.
【００２５】実施例１ 図１は本願発明の帯電装置の一実施例の要部構成を示す
縦断面図である。図３は一般的な磁気ブラシ帯電装置を
示す横断面図であるが、本実施例と同様の構成であるの
で、これを参照して説明する。Embodiment 1 FIG. 1 is a longitudinal sectional view showing the structure of the essential part of one embodiment of the charging device of the present invention. FIG. 3 is a cross-sectional view showing a general magnetic brush charging device, but since it has the same configuration as that of this embodiment, it will be described with reference to this.
【００２６】帯電装置20は、筐体25の開口を像形成体10
に対向するように配置し、その中に磁性粉体担体23、磁
性粉体21等を内包することにより、磁性粉体担体23上に
磁性粉体21による磁気ブラシを形成し、振動電界下で像
形成体10の感光層12を摺擦して帯電を行うものであり、
所謂接触帯電方式による帯電装置である。The charging device 20 includes an opening of the housing 25 and an image forming body 10.
The magnetic powder carrier 23, the magnetic powder 21 and the like are included in the magnetic powder carrier 23 to form a magnetic brush of the magnetic powder 21 on the magnetic powder carrier 23 under an oscillating electric field. The photosensitive layer 12 of the image forming body 10 is rubbed to perform charging.
The charging device is a so-called contact charging system.
【００２７】帯電装置20は帯電部材を像形成体10の移動
方向に対し、直交する矢印Ｘ方向に往復運動するための
構成を備えている。ここで、磁性粉体21、磁性粉体担体
23、磁性粉体担体23に内包される磁石22が帯電部材に相
当する。The charging device 20 has a structure for reciprocating the charging member in the direction of arrow X, which is orthogonal to the moving direction of the image forming body 10. Here, magnetic powder 21, magnetic powder carrier
23, the magnet 22 contained in the magnetic powder carrier 23 corresponds to the charging member.
【００２８】以下に、本実施例の帯電装置20における各
部構成を説明する。The configuration of each part of the charging device 20 of this embodiment will be described below.
【００２９】筐体25は、帯電部材を内包する主室を周壁
25cで形成し、更に周壁25cの左方側壁に超音波振動子51
等の往復運動源を収容する左室を周壁25dで形成してあ
る。周壁25cの両側方にはロール軸22a,22bの直径よりも
幾分大きめな円形状の穴部25a,25bを形成してある。The housing 25 has a main wall which encloses the charging member as a peripheral wall.
25c, and an ultrasonic transducer 51 on the left side wall of the peripheral wall 25c.
A left chamber for accommodating the reciprocating motion source such as is formed by the peripheral wall 25d. Circular holes 25a and 25b, which are slightly larger than the diameters of the roll shafts 22a and 22b, are formed on both sides of the peripheral wall 25c.
【００３０】筐体25の主室は磁性粉体21の貯蔵部を形成
し、この主室内に磁性粉体担体23を磁石ロール22が配置
されており、主室の出口には磁性粉体21の通過量を規制
する規制部材である非磁性の規制部材26が設けてあっ
て、磁性粉体担体23に付着して搬送される磁性粉体21層
の厚さを規制するようになっている。The main chamber of the housing 25 forms a storage unit for the magnetic powder 21, the magnetic powder carrier 23 and the magnet roll 22 are arranged in the main chamber, and the magnetic powder 21 is provided at the outlet of the main chamber. A non-magnetic restricting member 26, which is a restricting member that restricts the passage amount of the magnetic powder, is provided to restrict the thickness of the layer of the magnetic powder 21 attached to the magnetic powder carrier 23 and conveyed. .
【００３１】この結果、磁性粉体21の搬送量即ち帯電領
域における磁性粉体担体23上の磁性粉体21の存在量が10
〜300mg/cm2となるよう調整される。像形成体10と磁性
粉体担体23との間隙ＤRは厚さを規制された磁性粉体21
の磁気ブラシ21Aで接続される。撹拌部材27は磁性粉体2
1の偏りを修正する板状部材を軸の回りに有する回転体
である。As a result, the carrying amount of the magnetic powder 21, that is, the existing amount of the magnetic powder 21 on the magnetic powder carrier 23 in the charging area is 10%.
Adjusted to ~ 300 mg / cm 2 . The gap D R between the image forming body 10 and the magnetic powder carrier 23 is a magnetic powder 21 whose thickness is regulated.
It is connected by the magnetic brush 21A. Stirring member 27 is magnetic powder 2
A rotating body having a plate-shaped member for correcting the deviation of 1 around the axis.
【００３２】磁性粉体21としては導電性を有する球形フ
ェライト粒子を用いた。その他に磁性粉体と樹脂を主成
分としてこれを熱錬生後に粉砕して得られる導電性の磁
性樹脂粒子を用いることもできる。良好な帯電を行うた
めに、外形は真球で粒径50μm、比抵抗105Ω・cmに調整
されていて、トナーとの摩擦帯電量はトナー濃度１％の
条件で−５μC/gである。As the magnetic powder 21, spherical ferrite particles having conductivity are used. In addition, electrically conductive magnetic resin particles obtained by pulverizing the magnetic powder and a resin as the main components after thermal calcination can also be used. In order to perform good charging, the outer shape is adjusted to a spherical shape with a particle size of 50 μm and a specific resistance of 10 5 Ω · cm, and the amount of frictional charge with the toner is −5 μC / g at a toner concentration of 1%. .
【００３３】磁性粉体担体23は、非磁性金属で形成され
た導電性円筒状であり、一般にアルミニュウム、ステン
レス鋼などの金属或は半導性のプラスチックに0.1〜数
十μｍ程度の微細粗面加工を施したものであり、円柱状
の棒にＳ極及びＮ極を着磁した磁石ロール22を内包して
おり、磁性粉体担体23の側壁に軸23cを個設しており、
当該軸23cを筐体の側壁25cに形成した穴25aにシール材2
9を介して挿通し、更に当該軸23cの小径部を超音波振動
子51の穴を貫通してある。磁石ロール22の両端部にはロ
ール軸22a,22bを個設しており、ロール軸22aはベアリン
グ23aで磁性粉体担体23に嵌合しており、他方のロール
軸22bはベアリング23b 及びシール材29を介して筐体25
の周壁25cに形成した穴部25bに挿通して保持部材28で固
定してある。従って、磁石ロール22は筐体25に対して固
定してある。The magnetic powder carrier 23 has a conductive cylindrical shape formed of a non-magnetic metal, and is generally made of a metal such as aluminum or stainless steel or a semi-conductive plastic and has a fine rough surface of about 0.1 to several tens of μm. It is processed, and includes a magnet roll 22 in which a S pole and an N pole are magnetized in a cylindrical rod, and a shaft 23c is individually provided on a side wall of a magnetic powder carrier 23.
The shaft 23c is placed in the hole 25a formed in the side wall 25c of the housing and the sealing material 2
The small diameter portion of the shaft 23c passes through the hole of the ultrasonic transducer 51. Roll shafts 22a and 22b are individually provided at both ends of the magnet roll 22, the roll shaft 22a is fitted to the magnetic powder carrier 23 by a bearing 23a, and the other roll shaft 22b is a bearing 23b and a sealing material. Housing 25 through 29
It is inserted into a hole 25b formed in the peripheral wall 25c and fixed by a holding member 28. Therefore, the magnet roll 22 is fixed to the housing 25.
【００３４】シール材29は例えばスポンジ等の弾性部材
であり、磁性粉体担体23の振動を吸収すると共に磁性粉
体21の溢れるのを防止する。The sealing material 29 is an elastic member such as a sponge, which absorbs the vibration of the magnetic powder carrier 23 and prevents the magnetic powder 21 from overflowing.
【００３５】機械的振動手段は例えば、ピエゾ素子等の
超音波振動子に交流電源52から交流電圧を供給すること
によりロール軸を矢印Ｘ方向に振動させる。この時の振
動の振幅は0.1〜１mmであり、その周波数は0.1〜10KHz
である。なお、機械的振動手段は超音波振動子に限定さ
れるものでなく、高周波コイルを用いて前述の振幅及び
周波数で振動させてもよい。The mechanical vibrating means vibrates the roll shaft in the arrow X direction by supplying an AC voltage from an AC power supply 52 to an ultrasonic vibrator such as a piezo element. The vibration amplitude at this time is 0.1 to 1 mm, and the frequency is 0.1 to 10 KHz.
Is. The mechanical vibrating means is not limited to the ultrasonic vibrator, and a high-frequency coil may be used to vibrate with the above-mentioned amplitude and frequency.
【００３６】電源24はＶp-pを200〜3500Ｖの交流電圧源
と帯電すべき電圧と同じ値或は低い例えば−500〜−150
0Ｖに設定した可変直流電圧源とを直列接続したものと
等価とみなす。直流電圧源の一方の出力端子は導電性基
体11に接続し、導電性基体11は接地してある。一方、電
源24の出力端子を磁性粉体担体23に接続したものとな
る。磁性粉体担体23に付着して搬送される磁性粉体21層
は筐体25の開口に設けた規制板26により間隙の厚さに規
制する。これにより、磁性粉体21層は磁性粉体担体23と
感光層12を接続する。従って、電源24は磁性粉体担体23
と像形成体10の導電性基体11との0.1〜５mm間隙に前述
の電圧を印加することになり、像形成体10に直接電荷を
注入するので、低電圧でかつ、オゾンの発生を減少し、
交流成分を含むので極めて安定した均一帯電を行うこと
ができる。直流成分は定電圧制御をし、交流成分Ｖp-p
は定電流制御をすることになる。The power supply 24 has a V pp of the AC voltage source of 200 to 3500 V and the same or lower value than the voltage to be charged, for example, -500 to -150.
It is regarded as equivalent to a series connection of a variable DC voltage source set to 0V. One output terminal of the DC voltage source is connected to the conductive base 11, and the conductive base 11 is grounded. On the other hand, the output terminal of the power supply 24 is connected to the magnetic powder carrier 23. The layer of the magnetic powder 21 attached to the magnetic powder carrier 23 and conveyed is regulated by the regulation plate 26 provided in the opening of the housing 25 to the thickness of the gap. As a result, the magnetic powder 21 layer connects the magnetic powder carrier 23 and the photosensitive layer 12. Therefore, the power source 24 is the magnetic powder carrier 23.
The above voltage is applied to the gap of 0.1 to 5 mm between the image forming body 10 and the conductive substrate 11, and the charge is directly injected into the image forming body 10. Therefore, the voltage is low and the generation of ozone is reduced. ,
Since it contains an AC component, extremely stable uniform charging can be performed. DC component is controlled by constant voltage, AC component V pp
Will perform constant current control.
【００３７】像形成体10は導電性基体11の表面を覆うＯ
ＰＣ感光層12からなるドラムである。The image forming body 10 covers the surface of the conductive substrate 11 with O
This is a drum composed of the PC photosensitive layer 12.
【００３８】以下に本実施例の帯電装置20における帯電
動作を説明する。The charging operation of the charging device 20 of this embodiment will be described below.
【００３９】像形成体10を矢印Ａ方向に回転させながら
磁性粉体担体23を矢印Ｂ方向に像形成体10の周速度の0.
2〜1.2倍の周速度で回転させると、磁性粉体担体23に付
着・搬送される磁性粉体21の層は磁石22の磁力線により
磁性粉体担体23上の像形成体10との対向位置で磁気的に
鎖状に連結して一種のブラシ状になり、いわゆる磁気ブ
ラシ21Aが形成される。そしてこの磁気ブラシ21Aは磁性
粉体担体23の回転方向に搬送されて像形成体10の感光層
12に接触して摺擦する。磁性粉体担体23と像形成体10と
の間には前記交流バイアス電圧が印加されているので、
導電性の磁性粉体21を経て感光層12上に電荷が注入され
て帯電が行われる。この場合特に、交流バイアスを印加
することにより振動電界を形成したことと、規制部材26
と磁性粉体担体23との間隙ＤRは0.2mm以上5.0mm以下と
なるように設定され、像形成体10との対向位置での間隙
ＤSは通常ＤRの1.7〜1.5倍に規制され、帯電領域におけ
る磁性粉体21の量が適正に保持され磁気ブラシ21Aから
の電荷注入の効率を向上させることができる。これはＤ
Sで磁性粉体21からなる穂を十分に伸長した状態で像形
成体10に摺接するためである。While rotating the image forming body 10 in the direction of arrow A, the magnetic powder carrier 23 is moved in the direction of arrow B at the peripheral velocity of the image forming body 10.
When rotated at a peripheral speed of 2 to 1.2 times, the layer of the magnetic powder 21 adhered to and conveyed by the magnetic powder carrier 23 is located at a position facing the image forming body 10 on the magnetic powder carrier 23 due to the magnetic lines of force of the magnet 22. Then, they are magnetically linked in a chain shape to form a kind of brush shape, so-called magnetic brush 21A is formed. Then, the magnetic brush 21A is conveyed in the rotation direction of the magnetic powder carrier 23 to be a photosensitive layer of the image forming body 10.
Contact 12 and rub. Since the AC bias voltage is applied between the magnetic powder carrier 23 and the image forming body 10,
Electric charges are injected onto the photosensitive layer 12 through the electrically conductive magnetic powder 21 to be charged. In this case, in particular, the oscillating electric field is formed by applying the AC bias, and the regulating member 26
The gap D R between the magnetic powder carrier 23 and the magnetic powder carrier 23 is set to be 0.2 mm or more and 5.0 mm or less, and the gap D S at the position facing the image forming body 10 is normally regulated to 1.7 to 1.5 times D R. As a result, the amount of the magnetic powder 21 in the charging region is properly maintained, and the efficiency of charge injection from the magnetic brush 21A can be improved. This is D
This is because at S, the ears formed of the magnetic powder 21 are brought into slidable contact with the image forming body 10 in a sufficiently extended state.
【００４０】しかしながら、前述の帯電条件下で磁性粉
体21からなる磁気ブラシ21Aは図４に示すように粗であ
ることにより、像形成体10の移動方向にスジ状の帯電ム
ラを引き起こすことなる。However, since the magnetic brush 21A made of the magnetic powder 21 is rough as shown in FIG. 4 under the above-described charging conditions, streak-like charging unevenness is caused in the moving direction of the image forming body 10. .
【００４１】帯電装置20は磁性粉体担体23が回動するの
に期間に超音波振動子51に交流電圧を印加してある。超
音波振動子51は軸23cを介して磁性粉体担体23を0.1〜１
mmの振幅で、0.1〜10KHZの周波数で振動する。The charging device 20 applies an AC voltage to the ultrasonic vibrator 51 during the period when the magnetic powder carrier 23 rotates. The ultrasonic transducer 51 moves the magnetic powder carrier 23 through the shaft 23c from 0.1 to 1
It vibrates at a frequency of 0.1-10KHZ with an amplitude of mm.
【００４２】これにより磁性粉体担体23上の磁性ブラシ
21Aは図１に示す矢印Ｘ方向に約0.1〜１mmの振幅で、0.
1〜10KHZの周波数で像形成体10の感光層12に振動しなが
ら摺接することにより像形成体10の移動方向の被帯電面
各部が均一帯電されるように改善することができる。Thereby, the magnetic brush on the magnetic powder carrier 23
21A has an amplitude of about 0.1 to 1 mm in the arrow X direction shown in FIG.
By vibrating and slidingly contacting the photosensitive layer 12 of the image forming body 10 at a frequency of 1 to 10 KHZ, it is possible to improve such that each portion of the charged surface in the moving direction of the image forming body 10 is uniformly charged.
【００４３】なお、本実施例では磁気ブラシ帯電装置を
用いて説明したが、これに限定されるものでなく、静止
型ブラシ帯電方式等に適用しても同様に像形成体10の移
動方向の被帯電面各部が均一帯電することができる。Although the magnetic brush charging device has been described in the present embodiment, the present invention is not limited to this, and the same applies to a static brush charging system or the like in the moving direction of the image forming body 10. Each part of the surface to be charged can be uniformly charged.
【００４４】実施例２ 図２は本願発明の磁気ブラシ帯電装置の一実施例の要部
構成を示す断面図である。Embodiment 2 FIG. 2 is a sectional view showing the structure of the essential part of an embodiment of the magnetic brush charging device of the present invention.
【００４５】磁気ブラシ帯電装置20は、磁性粉体21と像
形成体10との接触する範囲（これを、以後帯電部とい
う）に多くの磁性粉体を送り込み磁性粉体21層をより高
密度にパッキングすることにより、磁性粉体を像形成体
10に均一に接触するようにしたものである。具体的には
帯電装置20は像形成体10に磁気ブラシ21Aを接触させて
交流バイアス下で帯電する磁気ブラシ帯電装置であり、
磁性粉体担体23と像形成体10との間隙をＤS、磁性粉体
担体23と磁気ブラシ21Aの層厚を規制する規制部材26と
の間隙ＤRとし、1.1≦ＤR／ＤS≦2.1とすることによ
り、帯電部に磁性粉体21を数多く送り込むので、密な状
態で磁性粉体21層を像形成体10の感光層12に摺接させる
ようにできる。更に帯電部における磁性粉体層の相対体
積率Ｑ（％）が40≦Ｑ≦60であるようにしたものであ
る。これにより像形成体10の移動方向の被帯電面各部が
均一帯電されるように改善するものである。The magnetic brush charging device 20 sends a large amount of magnetic powder to a range in which the magnetic powder 21 and the image forming body 10 are in contact with each other (hereinafter, referred to as a charging portion), so that the magnetic powder 21 layer has a higher density. The magnetic powder is packed into the image forming body.
It is designed to contact 10 evenly. Specifically, the charging device 20 is a magnetic brush charging device that contacts the magnetic brush 21A to the image forming body 10 and charges under an AC bias.
The gap between the magnetic powder carrier 23 and the image forming body 10 is D S , and the gap between the magnetic powder carrier 23 and the regulation member 26 that regulates the layer thickness of the magnetic brush 21A is D R, and 1.1 ≦ D R / D S ≦ By setting 2.1, a large amount of the magnetic powder 21 is sent to the charging portion, so that the magnetic powder 21 layer can be brought into slidable contact with the photosensitive layer 12 of the image forming body 10 in a dense state. Further, the relative volume ratio Q (%) of the magnetic powder layer in the charging portion is set to 40≤Q≤60. This improves each part of the surface to be charged in the moving direction of the image forming body 10 so as to be uniformly charged.
【００４６】以下に本実施例の各部構成について説明す
る。本実施例は上述の実施例とほぼ同様であり、機械的
振動手段及びこれと関連する構成を備えない点において
相違するので、共通の部材については同一の符号を付し
て詳述しない。The configuration of each part of this embodiment will be described below. This embodiment is almost the same as the above-mentioned embodiment and is different in that it does not have a mechanical vibrating means and a structure related thereto, and therefore common members are designated by the same reference numerals and will not be described in detail.
【００４７】磁性粉体21の条件は上述したのでここでは
省略する。The conditions for the magnetic powder 21 have been described above and will not be repeated here.
【００４８】粒子層を形成して像形成体を帯電する磁性
粉体の磁性粉体担体23に関する条件について述べる。The conditions for the magnetic powder carrier 23 of magnetic powder that forms a particle layer and charges the image forming body will be described.
【００４９】磁性粉体担体23は、バイアス電圧を印加し
得る導電性の磁性粉体担体が用いられるが、特に、表面
に粒子層が形成される導電性部材からなる円筒の内部に
複数の磁極を有する磁石22が設けられる構造のものが好
ましく用いられる。このような磁性粉体担体23におい
て、磁石22との相対的な回転によって、導電性の磁性粉
体担体23の表面に形成される粒子層が波状に起伏して移
動するようになるから、新しい磁性粉体が次々と供給さ
れ、磁性粉体担体23表面の粒子層に多少の層厚の不均一
があっても、その影響は上記波状の起伏によって実際上
問題とならないように十分カバーされる。そして、磁性
粉体担体23の回転による磁性粉体の搬送速度は、像形成
体10の移動速度より早くても良いが、ほとんど同じか、
それよりも遅いことが好ましい。磁性粉体を高温度で帯
電部に、滞留を起こさせず送り込むにはこの条件が好ま
しい。この搬送速度の相対比は0.2〜1.0倍であり、さら
に好ましくは0.2〜0.8倍である。0.2倍より小さいと搬
送それ自体が不足し、帯電が均一に行われないし、0.8
倍より大きくなるに従い磁性粉体の滞留が生じ易くな
る。又、磁性粉体担体23の回転による搬送方向は、同方
向が好ましい。像形成体10と磁性粉体担体23を同方向に
回転させたほうが帯電の均一性に優れているが、これに
限定されるものでない。As the magnetic powder carrier 23, a conductive magnetic powder carrier capable of applying a bias voltage is used. In particular, a plurality of magnetic poles are provided inside a cylinder made of a conductive member having a particle layer formed on the surface thereof. A structure having a magnet 22 having a is preferably used. In such a magnetic powder carrier 23, the relative rotation with the magnet 22 causes the particle layer formed on the surface of the conductive magnetic powder carrier 23 to undulate and move in a wavy shape, which is new. The magnetic powder is supplied one after another, and even if the particle layer on the surface of the magnetic powder carrier 23 has some non-uniformity in the layer thickness, the effect is sufficiently covered so that it does not actually cause a problem due to the corrugation. . The magnetic powder carrying speed by the rotation of the magnetic powder carrier 23 may be higher than the moving speed of the image forming body 10, but is almost the same,
It is preferably slower than that. This condition is preferable in order to send the magnetic powder to the charging section at a high temperature without causing retention. The relative ratio of the transport speeds is 0.2 to 1.0 times, more preferably 0.2 to 0.8 times. If it is less than 0.2 times, the transportation itself will be insufficient, and charging will not be performed uniformly, and 0.8
As it becomes larger than twice, retention of magnetic powder is likely to occur. In addition, it is preferable that the magnetic powder carrier 23 is rotated in the same direction as the conveying direction. Although the uniformity of charging is better when the image forming body 10 and the magnetic powder carrier 23 are rotated in the same direction, the present invention is not limited to this.
【００５０】磁性粉体担体23表面は磁性粉体21の安定な
均一搬送のために、表面平均荒さを２〜15μmとするこ
とが好ましい。平滑であると搬送が十分に行えなく、荒
すぎると面の凸部から過電流が流れ、どちらにしても帯
電ムラが生じ易いのでサンドブラスト処理が好ましく用
いられる。又その表面を酸化処理、樹脂コーティングに
より高抵抗処理することが好ましい。The surface of the magnetic powder carrier 23 preferably has an average surface roughness of 2 to 15 μm in order to stably and uniformly convey the magnetic powder 21. If it is smooth, it cannot be sufficiently conveyed, and if it is too rough, overcurrent flows from the convex portions of the surface, and uneven charging tends to occur in either case, so sandblasting is preferably used. Further, it is preferable to subject the surface to high resistance treatment by oxidation treatment or resin coating.
【００５１】磁性粉体担体23に形成する粒子層の厚さ
は、規制部材26によって十分に掻き落とされて均一な層
となる厚さであることが好ましい。帯電部において磁性
粉体担体23の表面上の磁性粉体の存在量が多すぎると磁
性粉体の振動が十分に行われず像形成体10との摩擦によ
る像形成体10へのダメージ、磁性粉体の像形成体10上へ
の付着や帯電ムラを起こすとともに過電流が流れ易く、
磁性粉体担体の駆動トルクが大きくなるという欠点があ
る。反対に磁性粉体の帯電部における磁性粉体担体23上
の存在量が少なすぎると像形成体10への接触に不完全な
部分を生じ易くなり、帯電ムラを起こすことになる。The thickness of the particle layer formed on the magnetic powder carrier 23 is preferably such that it is sufficiently scraped off by the regulating member 26 to form a uniform layer. If the amount of the magnetic powder present on the surface of the magnetic powder carrier 23 in the charging portion is too large, the vibration of the magnetic powder is not sufficiently performed, and the image forming body 10 is damaged by friction with the image forming body 10, and the magnetic powder is generated. Overcurrent easily flows as well as adhesion of the body on the image forming body 10 and uneven charging,
There is a drawback that the driving torque of the magnetic powder carrier becomes large. On the other hand, if the amount of the magnetic powder present on the magnetic powder carrier 23 in the charging portion is too small, an incomplete portion is likely to be brought into contact with the image forming body 10, resulting in uneven charging.
【００５２】磁性粉体担体23と像形成体10との最近接部
分での間隙ＤSは0.1mm ≦10mmが好ましく更に好ましく
は0.2mm≦ＤS≦5.0mmが好ましい。磁性粉体担体23と像
形成体10の表面の間隙が0.2mmよりも狭くなりすぎる
と、それに対応して均一に帯電作用する磁気ブラシの穂
を形成するのが困難となり、また、十分な磁性粉体を帯
電部に供給することができなくなって、安定した帯電が
行われなくなるし、間隙が1.0mmを大きく越すようにな
ると、粒子層が粗く形成されて帯電ムラが起き易く、ま
た、電荷注入効果が低下して十分な帯電が得られないよ
うになる。このように磁性粉体担体23と像形成体10との
間隙が極端になると、それに対して磁性粉体担体23上の
均一な粒子層として像形成をすることができなくなる
が、間隙ＤＳが０．２〜1.0mmの範囲では、それに対し
て粒子層の厚さを適当に形成することができ、密な均一
な状態の磁気ブラシが摺擦していることになる。The gap D S at the closest portion between the magnetic powder carrier 23 and the image forming body 10 is preferably 0.1 mm ≦ 10 mm, more preferably 0.2 mm ≦ D S ≦ 5.0 mm. If the gap between the surface of the magnetic powder carrier 23 and the surface of the image forming body 10 becomes too narrower than 0.2 mm, it becomes difficult to form the ears of the magnetic brush that uniformly charge, and sufficient magnetic properties are obtained. If powder cannot be supplied to the charging section, stable charging will not be performed, and if the gap greatly exceeds 1.0 mm, the particle layer will be formed coarsely and uneven charging will occur easily. The injection effect is reduced and sufficient charging cannot be obtained. When the gap between the magnetic powder carrier 23 and the image forming body 10 becomes extremely extreme as described above, it becomes impossible to form an image as a uniform particle layer on the magnetic powder carrier 23, but the gap D S is reduced. In the range of 0.2 to 1.0 mm, the thickness of the particle layer can be appropriately formed, and the magnetic brush in a dense and uniform state is rubbing.
【００５３】本実施例では帯電部に搬送される磁性粉体
21層を密な状態で接触させる構成について説明する。In this embodiment, magnetic powder conveyed to the charging section
A configuration in which 21 layers are brought into contact in a dense state will be described.
【００５４】図２において、磁性粉体担体23と像形成体
10との間隙をＤSとし、磁性粉体担体23と磁性粉体21層
の層厚を規制する規制部材26との間隙をＤRとして示し
てある。一般の磁気ブラシ帯電法と異なり、間隙ＤRを
間隙ＤSより小さくしてある。In FIG. 2, the magnetic powder carrier 23 and the image forming body are shown.
The gap between 10 and D S, Aru the gap between the regulating member 26 for regulating the layer thickness of the magnetic powder carrier 23 and magnetic powder 21 layers shown as D R. Unlike the general magnetic brush charging method, the gap D R is smaller than the gap D S.
【００５５】具体的には1.1≦ＤR／ＤS≦2.1となってい
る。一般の磁気ブラシ帯電法に比して単位時間当たりの
搬送量を大きくしたことに相当する。続いて、間隙ＤR
を通過する磁性粉体21層は帯電部を形成する間隙ＤSで
像形成体10に押圧されるので、従来の構成の磁気ブラシ
帯電法よりも相対体積比率Ｑが大きい状態で磁性粉体21
層は像形成体10の感光層12に摺接させることになる。こ
れにより像形成体10の移動方向の被帯電面各部が均一帯
電されるように改善することになる。Specifically, 1.1 ≦ D R / D S ≦ 2.1. This is equivalent to increasing the transport amount per unit time as compared with the general magnetic brush charging method. Then, the gap D R
Since the layer of magnetic powder 21 passing through is pressed against the image forming body 10 by the gap D S forming the charging portion, the magnetic powder 21 with the relative volume ratio Q larger than that of the conventional magnetic brush charging method.
The layer will be in sliding contact with the photosensitive layer 12 of the image forming body 10. As a result, each part of the surface to be charged in the moving direction of the image forming body 10 is improved so as to be uniformly charged.
【００５６】即ち、相対的な磁性粉体密度に相当する相
対体積比率Ｑが小さいときは、磁性粉体の鎖は粗となり
撹乱は少ない。このことが電荷の自由な移動を妨げ、均
一な帯電が行われなくなる原因と考えられる。That is, when the relative volume ratio Q corresponding to the relative magnetic powder density is small, the chains of the magnetic powder become coarse and the disturbance is small. It is considered that this hinders the free movement of the charges and prevents uniform charging.
【００５７】ここで、相対体積比率Ｑ（％）は帯電領域
における以下の式によって定義されるものである。Here, the relative volume ratio Q (%) is defined by the following equation in the charging region.
【００５８】Ｑ＝（Ｗ／ＤS ）×（１／ρ）×100 ここで、Ｗは搬送量即ち磁性粉体担体上の単位面積あた
りの磁性粉体の存在量（ｇ／cm2）、ＤSは前記間隙で単
位をcmとした値、ρは磁性粉体の比重（g／cm3）であ
る。Q = (W / D S ) × (1 / ρ) × 100 where W is the transport amount, that is, the amount of magnetic powder present per unit area on the magnetic powder carrier (g / cm 2 ), D S is the value of the gap in cm, and ρ is the specific gravity (g / cm 3 ) of the magnetic powder.
【００５９】帯電を均一で且つ高速で安定に行う実験を
重ねた結果、帯電領域における磁性粉体の相対体積比Ｑ
（％）を40≦Ｑ≦60としたとき、磁性粉体の付着や帯電
ムラのない均一な帯電特性が得られることが明らかとな
った。つまり、像形成体10の回転方向に発生する帯電ム
ラが解消される。As a result of repeated experiments in which the charging was carried out uniformly and stably at a high speed, the relative volume ratio Q of the magnetic powder in the charging region was Q.
When (%) is set to 40 ≦ Q ≦ 60, it has been clarified that uniform charging characteristics without adhesion of magnetic powder or uneven charging can be obtained. That is, charging unevenness that occurs in the rotation direction of the image forming body 10 is eliminated.
【００６０】即ち、Ｑが60％より小さいと磁性粉体が押
圧されて像形成体に均一に接触することにより均一帯電
が行える。しかし、40％より下回ると十分密な磁気ブラ
シの穂21Aが形成されないので完全な帯電が行われず帯
電ムラが発生する。一方、Ｑが60％より大きくなると磁
性粉体が詰まって送られなくなり、磁性粉体担体の回転
トルクが高くなり回転が高くなる。又、磁性粉体の圧縮
が起こり帯電領域上流部に滞留し、荷電流が発生したり
帯電領域が不要に広がったり、像形成体が傷ついたり、
像形成体10への磁性粉体の付着が発生する。That is, when Q is less than 60%, the magnetic powder is pressed and uniformly contacts the image forming body, so that uniform charging can be performed. However, if it is less than 40%, the sufficiently dense magnetic brush ears 21A are not formed, so that complete charging is not performed and charging unevenness occurs. On the other hand, when Q is more than 60%, the magnetic powder is clogged and cannot be fed, so that the rotation torque of the magnetic powder carrier becomes high and the rotation becomes high. In addition, the magnetic powder is compressed and stays in the upstream portion of the charging area, and a load current is generated, the charging area unnecessarily expands, the image forming body is damaged,
The magnetic powder adheres to the image forming body 10.
【００６１】本発明は実施例１の帯電装置を実施例２の
磁性粒子の搬送条件を組み合わせることにより、帯電ム
ラの解消に効果を発揮させることができる。According to the present invention, the charging device of the first embodiment is combined with the magnetic particle carrying conditions of the second embodiment, so that the effect of eliminating uneven charging can be exhibited.
【００６２】[0062]
【発明の効果】第１の発明によれば、接触帯電装置につ
いて像形成体の移動方向にでき易い帯電ムラを解消する
ことにより被帯電面各部が均一帯電されるように改善す
ることができる。According to the first aspect of the present invention, it is possible to improve the uniform charging of each part of the surface to be charged by eliminating the charging unevenness that tends to occur in the moving direction of the image forming body in the contact charging device.
【００６３】第２の発明によれば、磁気ブラシ帯電装置
について像形成体の移動方向にでき易い帯電ムラを解消
することにより被帯電面各部が均一帯電されるように改
善することができる。According to the second aspect of the present invention, it is possible to improve the charging of each portion of the surface to be charged uniformly by eliminating the charging unevenness that tends to occur in the moving direction of the image forming body in the magnetic brush charging device.
【図１】本願発明の帯電装置の一実施例の要部構成を示
す断面図である。FIG. 1 is a cross-sectional view showing a main configuration of an embodiment of a charging device of the present invention.
【図２】本願発明の磁気ブラシ帯電装置の一実施例の要
部構成を示す断面図である。FIG. 2 is a cross-sectional view showing a main configuration of an embodiment of a magnetic brush charging device of the present invention.
【図３】磁性粉体による磁気ブラシ帯電装置の概略構成
を示す図である。FIG. 3 is a diagram showing a schematic configuration of a magnetic brush charging device using magnetic powder.
【図４】ファーブラシ形式によるブラシ帯電器の概略構
成を示す断面図である。FIG. 4 is a cross-sectional view showing a schematic configuration of a brush charger of a fur brush type.
10 像形成体 11 導電性基体 12 感光層 20 磁気ブラシ帯電装置 21 磁性粉体 22 磁石（ロール） 22a ロール軸 22b ロール軸 22c 滑車 23 磁性粉体担体 24 電源 25 筐体 25a 穴部 25b 穴部 25c 周壁 25d 周壁 27 撹拌部材 29 シール材 30 ローラ帯電装置 31 芯金 32 導電性弾性層 33 中抵抗層 34 保護層 35 電源 40 ファーブラシ型ブラシ帯電装置 41 短繊維 42 電極 43 絶縁材 44 ヒータ 45 クッション材 51 超音波振動子 52 交流電源 ＤS 磁性粉体担体と像形成体との間隙 ＤR 磁性粉体担体と規制部材との間隙10 Image forming body 11 Conductive substrate 12 Photosensitive layer 20 Magnetic brush charging device 21 Magnetic powder 22 Magnet (roll) 22a Roll axis 22b Roll axis 22c Pulley 23 Magnetic powder carrier 24 Power supply 25 Housing 25a Hole 25b Hole 25c Peripheral wall 25d Peripheral wall 27 Stirring member 29 Sealing material 30 Roller charging device 31 Core metal 32 Conductive elastic layer 33 Medium resistance layer 34 Protective layer 35 Power supply 40 Fur brush type brush charging device 41 Short fiber 42 Electrode 43 Insulation material 44 Heater 45 Cushion material 51 Ultrasonic transducer 52 AC power supply D S Gap between magnetic powder carrier and image forming body D R Gap between magnetic powder carrier and regulating member
───────────────────────────────────────────────────── フロントページの続き (72)発明者 野守 弘之 東京都八王子市石川町2970番地コニカ株式 会社内 (72)発明者 福地 真和 東京都八王子市石川町2970番地コニカ株式 会社内 (72)発明者 森田 静雄 東京都八王子市石川町2970番地コニカ株式 会社内 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Hiroyuki Nomori Inside Konica Co., Ltd. 2970 Ishikawa-cho, Hachioji, Tokyo (72) Inventor Masakazu Fukuchi 2970 Ishikawa-cho Hachioji, Tokyo In Konica stock (72) Inventor Shizuo Morita 2970 Ishikawacho, Hachioji City, Tokyo Konica Stock Company
Claims (6)
バイアス下で帯電を行う帯電装置において、前記帯電部
材を像形成体の移動方向に対し、直交する方向に往復運
動を行うことを特徴とする帯電装置。1. A charging device for contacting an image forming body and a charging member to perform charging under an AC bias, wherein the charging member is reciprocated in a direction orthogonal to a moving direction of the image forming body. Characteristic charging device.
請求項１記載の帯電装置。2. The charging device according to claim 1, wherein the amplitude of the reciprocating motion is 0.1 to 1 mm.
る請求項１記載の帯電装置。3. The charging device according to claim 1, wherein the frequency of the reciprocating motion is 0.1 to 10 KHz.
ある請求項１記載の帯電装置。4. The charging device according to claim 1, wherein the charging member is a rotating brush-shaped member.
バイアス下で帯電する磁気ブラシ帯電装置において、磁
性粉体担体と像形成体との間隙をＤS、前記磁性粉体担
体と磁気ブラシの層厚を規制する規制部材との間隙ＤR
とし、1.1≦ＤR／ＤS≦2.1であることを特徴とする磁気
ブラシ帯電装置。5. A magnetic brush charging device, wherein a magnetic brush is brought into contact with an image forming body to be charged under an AC bias, wherein a gap D S between the magnetic powder carrier and the image forming body is D S , the magnetic powder carrier and the magnetic brush. gap D R of the regulating member for regulating the layer thickness of
And 1.1 ≦ D R / D S ≦ 2.1.
バイアス下で帯電する磁気ブラシ帯電装置において、帯
電部における磁気ブラシの相対体積率Ｑ（％）が40〜60
であることを特徴とする帯電装置。6. A magnetic brush charging device for charging a magnetic brush to an image forming body under an AC bias, wherein the relative volume ratio Q (%) of the magnetic brush in the charging section is 40 to 60.
A charging device characterized in that
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP5043862A JPH06258917A (en) | 1993-03-04 | 1993-03-04 | Electrostatic charger |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP5043862A JPH06258917A (en) | 1993-03-04 | 1993-03-04 | Electrostatic charger |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH06258917A true JPH06258917A (en) | 1994-09-16 |
Family
ID=12675514
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP5043862A Pending JPH06258917A (en) | 1993-03-04 | 1993-03-04 | Electrostatic charger |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH06258917A (en) |
Cited By (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5179390A (en) * | 1989-07-10 | 1993-01-12 | Canon Kabushiki Kaisha | Thermal transfer recording apparatus that securely transports the ink containing member |
| US5206661A (en) * | 1988-11-04 | 1993-04-27 | Canon Kabushiki Kaisha | Thermal transfer recording apparatus and method that stably conveys |
| US5248996A (en) * | 1990-02-01 | 1993-09-28 | Canon Kabushiki Kaisha | Thermal transfer recording apparatus which avoids ink sheet sticking after recording data reception is interrupted |
| US5266971A (en) * | 1990-02-01 | 1993-11-30 | Canon Kabushiki Kaisha | Thermal transfer recording apparatus and facsimile apparatus utilizing the same |
| US5418554A (en) * | 1989-02-21 | 1995-05-23 | Canon Kabushiki Kaisha | Image recording apparatus with recording sheet and ink sheet width detection |
| US5481291A (en) * | 1989-07-20 | 1996-01-02 | Canon Kabushiki Kaisha | Recording apparatus with improved ink sheet conveyance |
| CN112290634A (en) * | 2020-11-03 | 2021-01-29 | Tcl通讯（宁波）有限公司 | Charging device |
Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS63150863U (en) * | 1987-03-25 | 1988-10-04 |
-
1993
- 1993-03-04 JP JP5043862A patent/JPH06258917A/en active Pending
Patent Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS63150863U (en) * | 1987-03-25 | 1988-10-04 |
Cited By (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5206661A (en) * | 1988-11-04 | 1993-04-27 | Canon Kabushiki Kaisha | Thermal transfer recording apparatus and method that stably conveys |
| US5418554A (en) * | 1989-02-21 | 1995-05-23 | Canon Kabushiki Kaisha | Image recording apparatus with recording sheet and ink sheet width detection |
| US5179390A (en) * | 1989-07-10 | 1993-01-12 | Canon Kabushiki Kaisha | Thermal transfer recording apparatus that securely transports the ink containing member |
| US5481291A (en) * | 1989-07-20 | 1996-01-02 | Canon Kabushiki Kaisha | Recording apparatus with improved ink sheet conveyance |
| US5579042A (en) * | 1989-07-20 | 1996-11-26 | Canon Kabushiki Kaisha | Recording apparatus with improved ink sheet conveyance |
| US5248996A (en) * | 1990-02-01 | 1993-09-28 | Canon Kabushiki Kaisha | Thermal transfer recording apparatus which avoids ink sheet sticking after recording data reception is interrupted |
| US5266971A (en) * | 1990-02-01 | 1993-11-30 | Canon Kabushiki Kaisha | Thermal transfer recording apparatus and facsimile apparatus utilizing the same |
| US5623299A (en) * | 1990-02-01 | 1997-04-22 | Canon Kabushiki Kaisha | Thermal transfer recording apparatus with ink sheet and recording medium transported by predetermined amounts |
| CN112290634A (en) * | 2020-11-03 | 2021-01-29 | Tcl通讯（宁波）有限公司 | Charging device |
| CN112290634B (en) * | 2020-11-03 | 2022-08-05 | Tcl通讯（宁波）有限公司 | Charging device |
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