JPH043181A - Electrifying device - Google Patents

Abstract

PURPOSE:To allow the good electrifying processing of the surface of a body to be electrified, such as photosensitive drum, by a contact electrifying body system by setting the width of a conductive member in the part opposite to the body to be electrified to a specific range. CONSTITUTION:The photosensitive drum 1 consists of the drum base body 1b made of aluminum and a photosensitive body layer 1a formed on the outer peripheral surface of the base body 1b and is rotationally driven at a prescribed speed in a clockwise direction. A conductive member 10a which is made of a tungsten wire and is subjected to a coating treatment 10b with a fluororesin contg. carbon subjected to resistance control on the outer peripheral surface thereof is used as an electrifying wire 10. This coating layer 10b constitutes the resistance member to be interposed between the photosensitive drum 1 as the body to be electrified and the conductive member 10a. The width (d) of the part of the conductive member opposite to the body to be electrified is set at 5mum<d<1,000mum. The electrifying sound generated with the electrifying device of the contact electrifying system is decreased or substantially eliminated in this way.

Description

【発明の詳細な説明】 （産業上の利用分野） 本発明は、電圧を印加した帯電部材を被帯電体に当接さ
せて被帯電体面を所定の電位に帯電処理（除電処理も含
む、以下同じ）する接触帯電装置に関する。DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention is a method of charging the surface of a charged object to a predetermined potential by bringing a charging member to which a voltage is applied into contact with a charged object (including static electricity removal processing). The same applies to contact charging devices.

（従来の技ｉ） 例えば、電子写真装置（複写機・レーザーヒームプリン
タなと）・静電記録装置等の画像形成装置に於て、感光
体・誘電体等の被帯電体としての像担持体面を帯電処理
する手段機器としでは従来よりコロナ放電装置が広く利
用されている。(Conventional technique i) For example, in image forming devices such as electrophotographic devices (copying machines, laser beam printers, etc.) and electrostatic recording devices, image bearing as a charged body such as a photoreceptor or dielectric Corona discharge devices have been widely used as devices for charging the body surface.

コロナ放電装置は像担持体等の被帯電体面を所定の電位
に均一に帯電処理する手段として有効である。しかし、
高圧電源を必要とし、コロナ放電により好ましくないオ
ゾンか比較的多く発生するなとの問題点を有している。A corona discharge device is effective as a means for uniformly charging the surface of an object to be charged, such as an image carrier, to a predetermined potential. but,
It requires a high-voltage power supply and has the problem of generating a relatively large amount of undesirable ozone due to corona discharge.

このようなコロナ放電装置に対して、前記のように電圧
を印加した帯電部材を被帯電体に接触させて被帯電体面
を帯電処理する接触帯電装置は、電源の低圧化が図れ、
オゾンの発生をみても極々微量である等の長所を有して
いることから、例えば画像形成装置に於て感光体・誘電
体等の像担持体、その他の被帯電体面を帯電処理する、
コロナ放電装置に代わる手段装置として注目され、その
実用化研究か進められている（特開昭５７−１７８２６
７・５６−１０４３５１・５８−４０５６６・５８−１
１９＋５６・５８−１５０９７５号公報等）。In contrast to such a corona discharge device, a contact charging device, which charges the surface of the charged object by bringing a charging member to which a voltage is applied as described above into contact with the charged object, can reduce the voltage of the power source, and
Since it has the advantage of generating only a very small amount of ozone, it is used, for example, in image forming apparatuses to charge the surface of image carriers such as photoreceptors and dielectrics, and other objects to be charged.
It has attracted attention as an alternative to corona discharge devices, and research into its practical application is underway (Japanese Patent Application Laid-Open No. 17826-1982).
7・56-104351・58-40566・58-1
19+56, 58-150975, etc.).

本出願人も、均一な帯電処理等を目的として、帯電部材
に対して、直流電圧と、被帯電体の帯電開始電圧の２倍
以上のピーク間電圧を有する振動電圧（時間とともに電
圧値か周期的に変化する電圧）を印加することを基本と
する接触帯電方法ないしは装置なと数多くの提案を行な
っている（特開昭６３−１４９６６８・１４９６６９号
公報等）。The present applicant also applied a direct current voltage to a charging member and an oscillating voltage having a peak-to-peak voltage that is more than twice the charging start voltage of the charged object (with the voltage value changing over time) for the purpose of uniform charging processing, etc. Many proposals have been made for contact charging methods and devices based on the application of a voltage that changes over time (Japanese Patent Laid-Open Nos. 149668 and 149669, 1983, etc.).

帯電部材は一般にローラ型もしくはプレート型の構成の
ものか用いられている。The charging member generally has a roller type or plate type construction.

第１０図は像担持体の帯電処理手段としてローラ型の接
触帯電部材を使用した画像形成装置の一例の概略構成を
示している。本例の画像形成装置は転写方式の電子写真
装置（複写機、レーザービームプリンタなど）である。FIG. 10 shows a schematic configuration of an example of an image forming apparatus using a roller type contact charging member as a charging processing means for an image carrier. The image forming apparatus in this example is a transfer type electrophotographic apparatus (copying machine, laser beam printer, etc.).

１は被帯電体としての回転ドラム型の電子写真感光体（
以下、感光ドラムと記す）であり、矢印の時計方向に所
定の周速度（プロセススピード）をもって回転駆動され
る。1 is a rotating drum-type electrophotographic photoreceptor (
(hereinafter referred to as a photosensitive drum), which is rotated clockwise as indicated by an arrow at a predetermined circumferential speed (process speed).

２は接触帯電部材としての帯電ローラてあり、鉄・銅・
アルミニウム・ステンレススチール（ＳＵＳ＞等の導電
性芯金２ａと、その外周をローラ状に被覆させて設けた
、カーボンを含んだＥ　ＰＤＭ・ウレタン等で出来た低
抵抗層２ｂとトレシン・工どクロルヒドリンゴム等から
なる高抵抗層２Ｃからなり、該ローラ２は芯金２ａの両
端側を不図示のハネ等の加圧手段により加圧してローラ
全長部を感光ドラム１面に対して所定の押圧力をもって
ドラム母線方向に略並行させて当接させてあり、本例の
場合は感光トラム１の回転に伴い従動回転する。2 is a charging roller as a contact charging member, which is made of iron, copper,
A conductive core metal 2a made of aluminum, stainless steel (SUS), etc., a low resistance layer 2b made of carbon-containing E PDM, urethane, etc., whose outer periphery is coated in a roller shape, and a low resistance layer 2b made of carbon-containing EPDM, urethane, etc. The roller 2 is made of a high-resistance layer 2C made of hydrin rubber, etc., and the roller 2 presses both ends of the core metal 2a with pressure means such as springs (not shown) to press the entire length of the roller against the surface of the photosensitive drum. The drum is brought into contact with pressure substantially parallel to the generatrix direction of the drum, and in this example, rotates as the photosensitive tram 1 rotates.

９は帯電ローラ２に対して電圧を印加する外部電源で、
該電＃９により帯電ローラ２に対して予め設定された、
直流電圧と、感光体の帯電開始電圧の２倍以上のど−り
間電圧の振動電圧との重畳電圧が接点ハネ８・芯金２３
を介して印加されることで、回転駆動されている感光ト
ラム１の外周面が所定の電位に帯電処理される。9 is an external power source that applies voltage to the charging roller 2;
Preset for the charging roller 2 by the voltage #9,
A superimposed voltage of a DC voltage and an oscillating voltage with a voltage that is more than twice the charging start voltage of the photoconductor is applied to the contact spring 8 and the core bar 23.
By applying the electric potential through the electric potential, the outer circumferential surface of the rotationally driven photosensitive tram 1 is charged to a predetermined electric potential.

次いでその感光ドラム１の帯電処理面に対して不図示の
露光手段により原稿画像の結像露光または印字情報に対
応して変調されたレーザー光による走査露光などの画像
露光３がなされて目的の画像情報に対応した静電潜像が
感光ドラム１面に順次に形成されていく。Next, the charged surface of the photosensitive drum 1 is subjected to image exposure 3, such as image-forming exposure of the original image or scanning exposure with a laser beam modulated in accordance with printed information, by an exposure means (not shown) to form a target image. Electrostatic latent images corresponding to information are sequentially formed on the surface of the photosensitive drum.

次いてその感光ドラム１面に対して現像装置の現像スリ
ーブ４からトナーか供給されて感光ドラム１而の形成潜
像が順次にトナー像として現像されていく。Next, toner is supplied from a developing sleeve 4 of a developing device to the surface of the photosensitive drum 1, and the latent image formed on the photosensitive drum 1 is sequentially developed as a toner image.

５は現像スリーブ４よりも感光トラム回転方向下流側に
おいて感光ドラムｌに圧接させた転写ローラであり、不
図示の給紙部から転写材７か感光ドラム１と転写ローラ
５との圧接部（転写部）に対して、感光ドラム１面のト
ナー像の先端部が圧接部へ到着したとき転写材７の先端
部も圧接部へ丁度到着するタイミングをもって感光ドラ
ムの回転と周期とりされて供給される。Reference numeral 5 denotes a transfer roller that is brought into pressure contact with the photosensitive drum l on the downstream side of the developing sleeve 4 in the rotational direction of the photosensitive drum. With respect to part), when the leading edge of the toner image on the surface of the photosensitive drum 1 reaches the pressure contact part, the leading edge of the transfer material 7 also arrives at the pressure contact part, and the transfer material 7 is supplied in a period synchronized with the rotation of the photosensitive drum. .

転写ローラ５には電源から転写バイアスが印加されてお
り、転写材７が上記圧接部を通過していく過程で感光ド
ラム１面のトナー像が転写材７側へ順次に移転（転写）
する。A transfer bias is applied to the transfer roller 5 from a power source, and as the transfer material 7 passes through the pressure contact section, the toner image on the surface of the photosensitive drum 1 is sequentially transferred to the transfer material 7 side (transfer).
do.

トナー像転写後の感光ドラム１面はクリーニング装置６
て転写残りトナー等の残留物の除去を受けて清掃され、
縁り返して像形成に供される。After the toner image has been transferred, one surface of the photosensitive drum is cleaned by a cleaning device 6.
It is cleaned by removing residuals such as untransferred toner.
The edges are turned over and used for image formation.

（発明が解決しようとする問題点） しかしなから上記従来例では以下のような問題点かある
。(Problems to be Solved by the Invention) However, the above conventional example has the following problems.

１）耐久により帯電部材としての帯電ローラのゴム層２
ｂ・２Ｃから、ゴムの可塑剤か滲みたし被帯電体たる感
光トラム１の表面に付着したり、融着したりして、画像
流れを生じさせる原因になっていた。1) Rubber layer 2 of the charging roller as a charging member due to durability
From b.2C, the plasticizer of the rubber oozed out and adhered or fused to the surface of the photosensitive tram 1, which was the object to be charged, causing image deletion.

２）Ａ３サイズ用の帯電ローラ２では軸方向の長さもそ
れにつれて長くなり、帯電ローラ２をその両端側をバネ
等の加圧手段により加圧して感光トラム１にドラム母線
並行させて押し当てたとき、ローラ中央部か感光トラム
１の表面から浮いてしまいその部分で帯電不良が発生し
てしまう。2) In the charging roller 2 for A3 size, the length in the axial direction becomes longer accordingly, and the charging roller 2 is pressed against the photosensitive tram 1 parallel to the drum bus line by pressing both ends thereof with a pressure means such as a spring. At this time, the central portion of the roller floats off the surface of the photosensitive tram 1, resulting in charging failure at that portion.

３）プロセススど一トの速い機種では帯電不良防止のた
めプロセススピードの速さにあわせて帯電ローラ２に印
加する１次電源周波数も上げなければならないが、それ
に伴ない感光トラム１と帯電ローラ２が振動しあって発
生する帯電音が大きくなる。3) In models with a fast process speed, the primary power frequency applied to the charging roller 2 must be increased in accordance with the process speed to prevent charging failures, but as a result, the photosensitive tram 1 and charging roller 2 vibrate each other, and the charging noise generated becomes louder.

帯電ローラに印加するバイアスのど−り間電圧を小さく
することで帯電層を実用ト許容範囲へｔげていくと、必
要な電流か流れにくくなり、帯電不良を発生する結果と
もなる。If the voltage of the bias voltage applied to the charging roller is reduced to raise the charging layer to a practical allowable range, it becomes difficult for the necessary current to flow, resulting in charging failure.

本発明はＬｍ記のような問題点なく、感光トラムなとの
被帯電体面を接触帯電方式で良好に帯電処理することを
可能にしたものである。The present invention makes it possible to satisfactorily charge the surface of a charged object such as a photosensitive tram by a contact charging method without having the problems mentioned above.

（問題点を解決するための手段） 本発明は、電圧を印加した導電性部材を直接に又は抵抗
部材を介して被帯電体に当接させて被帯電体面の帯電を
行なう接触式の帯電装置であり、航記導電性部材の被帯
電体に対する対向部の幅ｄを５μｍ＜ｄ＜１０００μｍ
に設定したことを特徴とする帯電装置を要旨とする。(Means for Solving the Problems) The present invention is a contact-type charging device that charges the surface of a charged object by bringing a conductive member to which a voltage is applied into contact with the charged object directly or through a resistive member. The width d of the portion of the electrically conductive member facing the charged object is 5 μm<d<1000 μm.
The gist of the present invention is a charging device that is characterized by being set to .

（作　用） （１）被帯電体に対する対向部の幅ｄか５μｍ＜ｄ＜１
０００４ｍ の接触帯電部材としての導電性部材は、−数的には、直
径又は幅か５〜１０００μｍの導電性線材の形態、或い
は厚さか５〜ｉ　ｏｏｏμｍの導電性薄板材の形態のも
のとすることかでき、その導電性線材を接触帯電部材と
して被帯電体面に腹当り直接に当接させる、或いは導電
性薄板材のエツジ部を直接に当接させる。(Function) (1) Width d of the part facing the charged object is 5μm<d<1
The conductive member as a contact charging member of 0004m is numerically in the form of a conductive wire with a diameter or width of 5 to 1000 μm, or in the form of a conductive thin plate material with a thickness of 5 to ioooo μm. The conductive wire can be used as a contact charging member to directly contact the surface of the object to be charged, or the edge portion of the conductive thin plate material can be brought into direct contact with the surface of the object to be charged.

該導電性線材や導電性薄板を抵抗部材を介して被帯電体
に当接させる場合の該抵抗部材は一般的にはその導電性
の線材や薄板材の表面被覆層の形態とすることかできる
。When the conductive wire or conductive thin plate is brought into contact with the charged object via a resistive member, the resistive member can generally be in the form of a surface coating layer of the conductive wire or thin plate. .

（２）接触帯電部材としての電圧を印加した導電性部材
を直接に又は抵抗部材を介して被帯電体面に対して当接
させて相対移動させることで、接触帯電ローラや接触帯
電プレートの場合と間柱に被帯電体面の接触帯電処理が
なされる。(2) By bringing a conductive member to which a voltage is applied as a contact charging member into contact with the surface of the charged object directly or through a resistance member and moving it relative to the surface of the object to be charged, it can be used as a contact charging roller or a contact charging plate. Contact charging treatment is performed on the surface of the object to be charged on the stud.

（３）接触帯電ローラや接触帯電プレートの場合とは異
なり、ゴム等から構成れさる帯電層を持っていないため
、ゴム帯電層からにしみでる可塑剤の被帯電体面への付
着・融着、それによる画像形成装置における画像流れと
いった問題の発生を押えることか（ｒ’ｆ能となった。(3) Unlike contact charging rollers and contact charging plates, they do not have a charging layer made of rubber or the like, so plasticizer seeping from the rubber charging layer may adhere or fuse to the surface of the charged object. In order to suppress the occurrence of problems such as image blurring in the image forming apparatus due to this, it has become possible to prevent the occurrence of problems such as image blurring in the image forming apparatus.

（４）接触帯電部材か（１）項で述へた線材や板材のよ
うな形態のものは適当な押え込み手段や支持持丁段によ
って線材の全長部或は薄板材のエツジ部の全長部を被帯
電体面に対して各部浮きなく押え込んて当接状態に保持
させることか容易であり、接触帯電ローラの場合のよう
な中央部の浮き、その浮きに起因する帯電不良の問題を
解消することが可能となる。(4) For contact charging members, such as wire rods and plate materials mentioned in item (1), the entire length of the wire rod or the entire length of the edge portion of the thin plate material is It is easy to press and hold each part in contact with the surface of the charged object without floating, and eliminates the problem of floating in the center and poor charging caused by the floating as in the case of contact charging rollers. becomes possible.

（５）被帯電体に直接に又は抵抗部材を介して当接させ
る接触帯電部材としての導電性部材の被帯電体に対する
対向部の幅ｄを ５μｍ＜ｄ＜１０００μｍ と小さいものに設定したことで帯電層の発生を実用」二
支障がない範囲内に低下させる、或いは実質的になくす
ることができた。(5) By setting the width d of the portion facing the charged object of the conductive member as a contact charging member that comes into contact with the charged object directly or through a resistance member to be as small as 5 μm<d<1000 μm. It was possible to reduce the occurrence of a charged layer to within a range that causes no problems in practical use, or to substantially eliminate it.

この理由は、帯電ローラの場合、帯電ローラに外部バイ
アスを印加するとローラが振動を始め、ローラと被帯電
体との間に挟まっていた空気の流動で帯電層が発生して
いたのであるが、上記のように幅ｄを５μｍ＜ｄ＜１０
００μｍと小さいものに設定すると接触帯電部材と被帯
電体との間に挟まる空気か無いため該接触帯電部材か撮
動しても帯電層か低下するか、実質的になくなるものと
考えられる。The reason for this is that in the case of a charging roller, when an external bias was applied to the charging roller, the roller began to vibrate, and a charged layer was generated due to the flow of air caught between the roller and the charged object. As above, the width d is 5μm<d<10
If it is set to a small value of 00 μm, there will be no air trapped between the contact charging member and the object to be charged, so even if the contact charging member is photographed, the charged layer will be reduced or substantially eliminated.

（６）接触帯電部材としての導電性部材を抵抗部材を介
して被帯電体に当接させて被帯電体面の帯電処理をする
場合は被帯電体にピンホール等の表面欠陥が存在してい
てもリークによる給電部の電圧降下が防止され、接触帯
電部材が被帯電体と接触している領域全体の帯電不良を
防止することが可能になる。(6) When charging the surface of the charged object by bringing a conductive member as a contact charging member into contact with the charged object via a resistive member, the surface of the charged object may have surface defects such as pinholes. This also prevents a voltage drop in the power supply section due to leakage, and prevents charging failures in the entire area where the contact charging member is in contact with the object to be charged.

即ち、接触帯電部材は裸の金属ワイヤなと無被覆の導電
性部材そのものを使用することかできるのであるか、例
えば航述例の画像形成装置において被帯電体としての感
光ドラムになんらかの原因（例えば打痕や異物混入等）
でどンホールか生した場合、接触帯電部材が無被覆の導
電性部材であるとどンホール部か該帯電部材と感光ドラ
ムの接点である帯電領域に移動したとき該帯電部材と感
光ドラムのどンホールの間でリークか発生して給電部の
電圧が著しく降下してしまう。In other words, can a bare metal wire or an uncoated conductive member itself be used as the contact charging member? dents, foreign matter, etc.)
If the contact charging member is an uncoated conductive member, when the contact charging member moves to the charging area that is the contact point between the charging member and the photosensitive drum, the contact charging member and the photosensitive drum will form holes in the contact charging member and the photosensitive drum. If a leak occurs between the two, the voltage at the power supply section will drop significantly.

そのため、このリーク発生時は帯電部材と感光ドラムと
の接点の長手方向全体か帯電不良となり、実際の画像上
に於ては反転現象では黒帯状、正規現象では白帯状の画
像むらか感光トラムの回転周期毎に現われ画像品質が著
しく低下する。Therefore, when this leak occurs, the entire longitudinal direction of the contact between the charging member and the photosensitive drum becomes defective in charging, and in the actual image, there is a black band-like image in the case of an inversion phenomenon, and a white band-like image unevenness in the normal phenomenon. It appears at every rotation period and the image quality deteriorates significantly.

これに対して接触帯電部材としての電圧を印加した導電
性部材を抵抗部材を介して被帯電体に当接させた態様で
被帯電体面の帯電処理を実行することで抵抗部材の体積
抵抗率が導電性部材より大きいので抵抗部材を伝わって
被帯電体側のピンホール等の表面欠陥部へ流れ込む電流
が小さくなり、たとえ被帯電体にどンホール等の表面欠
陥が生じてもその部分に於て接触帯電部材とのリーク（
過剰電流流れ）による給電部の電圧降下を防止すること
が出来る。従って、被帯電体面にピンホール等かあフて
も接触帯電部材か被帯電体と接触している領域全体の帯
電不良を防＋ｈすることか出来る。画像形成装置にあっ
ては前述の画像品質の低下の問題か解消される。しかも
、供給電圧なア・ツブする事なく現状のままで被帯電体
に十分電圧かかかるので、交流電圧不足による帯電不良
中帯電むらも防１トすることが出来る。On the other hand, the volume resistivity of the resistance member can be increased by carrying out the charging process on the surface of the object to be charged in such a manner that a conductive member to which a voltage is applied as a contact charging member is brought into contact with the object to be charged through the resistance member. Since it is larger than the conductive member, the current that flows through the resistive member and into surface defects such as pinholes on the charged object side is small, so even if there is a surface defect such as a hole on the charged object, it will not make contact at that part. Leak from charging member (
It is possible to prevent a voltage drop in the power supply section due to excessive current flow. Therefore, even if there is a pinhole or the like on the surface of the object to be charged, it is possible to prevent charging failures in the contact charging member or the entire area in contact with the object to be charged. In the image forming apparatus, the above-mentioned problem of image quality deterioration is solved. In addition, since sufficient voltage is applied to the object to be charged as it is without any drop in the supply voltage, it is possible to prevent charging irregularities during charging failures due to insufficient AC voltage.

上記の効果は、接触帯電部材に印加する交流電圧のピー
ク間電圧を直流電圧のみ印加したときの被帯電体を帯電
する帯電開始電圧の２倍以上にする接触帯電方式に於て
特に有効である。The above effect is particularly effective in a contact charging method in which the peak-to-peak voltage of the AC voltage applied to the contact charging member is more than twice the charging start voltage at which the charged object is charged when only DC voltage is applied. .

（実　施　例） 〈実施例１〉（第１〜５図） 第１図は本発明の帯電装置の一例の側面図、第２図はそ
の平面図、第３図はその斜視図である。(Example) <Example 1> (Figs. 1 to 5) Fig. 1 is a side view of an example of the charging device of the present invention, Fig. 2 is a plan view thereof, and Fig. 3 is a perspective view thereof.

１は前述第Ｉ０図の画像形成装置における被帯電体とし
ての感光ドラムであり、該感光ドラム１はアルミニウム
製のドラム基体１ｂと該基体１ｂの外周面に形成された
感光体層１ａ（本実施例では有機感光体（ＯＰＣ））と
からなり、本実施例では外径３０φとされ、矢印の時計
方向に所定の速度で回転駆動される。Reference numeral 1 designates a photosensitive drum as a charged member in the image forming apparatus shown in FIG. In this example, it consists of an organic photoreceptor (OPC), has an outer diameter of 30φ in this example, and is driven to rotate at a predetermined speed in the clockwise direction of the arrow.

１０は接触帯電部材としての帯電線材（以下、帯電ワイ
ヤと記す）であり、本実施例では第４図（ｅ）の断面模
型図のように該帯電ワイヤ１０は直径ｄか６０μｍのタ
ングステン線を導電性部材（電極）１０ａとし、その外
周面を体積抵抗率を１０１０Ωｃｍに抵抗制御したカー
ボン入りふっそ樹脂（商品名、エムラロン、日本アジソ
ン社）を厚さ２５μｍに被覆処理１０ｂしたものを用い
た。この被覆層１０ｂか被帯電体としての感光トラム１
と導電性部材１０ａとの間に介在する抵抗部材となる。Reference numeral 10 denotes a charging wire material (hereinafter referred to as charging wire) as a contact charging member. In this embodiment, as shown in the cross-sectional model diagram of FIG. 4(e), the charging wire 10 is a tungsten wire with a diameter of d or 60 μm. A conductive member (electrode) 10a was used, the outer peripheral surface of which was coated to a thickness of 25 μm with carbon-containing fusso resin (trade name, Emlaron, Nippon Addison Co., Ltd.) whose volume resistivity was controlled to 1010 Ωcm. . This coating layer 10b or the photosensitive tram 1 as a charged object
This serves as a resistance member interposed between the conductive member 10a and the conductive member 10a.

導電性部材としてのタングステン＠　１０　ａの直径寸
法ｄが被帯電体としての感光トラム１に対する対向部の
幅である。The diameter dimension d of the tungsten@10a as the conductive member is the width of the portion facing the photosensitive tram 1 as the charged object.

導電性部材１０ａはタングステンに限らず、鉄・銅・ア
ルミニウム・ＳＵＳなど導電性材質のものであればよい
。断面形状は円形に限らす第４図（ｆ）　・　（ｇ）　
・（ｈ）のように三角形・四角形（矩形）・楕円形なと
任意である。The conductive member 10a is not limited to tungsten, but may be made of a conductive material such as iron, copper, aluminum, or SUS. The cross-sectional shape is limited to circular Figure 4 (f) and (g)
・As shown in (h), it can be any triangle, quadrilateral (rectangle), or ellipse.

抵抗部材としての被覆層１０ｂは一般に１０〜１０００
μｍの層厚とされる。被覆層１０ｂは第４図（ｉ）・（
ｊ）・（ｋ）・（［）のように導電性部材１０ａの被帯
電体１面に対向する部分面に限定形成した形態に施こし
てもよい。The coating layer 10b as a resistance member generally has a thickness of 10 to 1000
The layer thickness is assumed to be μm. The coating layer 10b is shown in FIG.
j), (k), and ([) may be formed only on the partial surface of the conductive member 10a that faces the surface of the object to be charged.

接触帯電部材１０は第４図（ａ）・（ｂ）（Ｃ）・　（
ｄ）のように被覆層のない裸の導電性部材を用いること
もてきる。The contact charging member 10 is shown in FIGS. 4(a), (b), (C), and (
It is also possible to use a bare conductive member without a covering layer as in d).

抵抗部材としての被覆層１０ｂを構成させる材料として
は、その他、Ｎ−メトキシメヂル化ナイロン（商品名ト
レジン：帝国化学産業■）、ポリビニルブチラール樹脂
、ポリウレタン樹脂、エチレン・酢酸ビニル樹脂、スチ
レン・ブタジェン樹脂、再生セルロース等の樹脂、さら
には、工どクロルヒドリン、ウレタン、ＣＲ，ＮＢＲ系
のゴム等を用いることが出来る。更に熱収縮チューブを
用いることも可能である。In addition, the materials constituting the coating layer 10b as a resistance member include N-methoxymethylated nylon (trade name: Torezine: Teikoku Kagaku Sangyo ■), polyvinyl butyral resin, polyurethane resin, ethylene/vinyl acetate resin, styrene/butadiene resin, Resins such as regenerated cellulose, as well as engineered chlorohydrin, urethane, CR and NBR rubbers, etc. can be used. Furthermore, it is also possible to use a heat shrink tube.

而して、本実施例において帯電ワイヤ１０はその左右端
側をデルリン等で作った押し当て部材１１・１１により
感光ドラム１面に対してドラムｍ線とほぼ並行に圧接さ
せである。１２・１２は押し当て部材１１・１１を感光
トラム感光トラム１の方向へ常時押圧付勢するためのハ
ネを示す。In this embodiment, the left and right ends of the charging wire 10 are pressed against the surface of the photosensitive drum 1 by pressing members 11 made of Delrin or the like, substantially parallel to the drum line m. Reference numerals 12 and 12 indicate springs for constantly pressing and biasing the pressing members 11 and 11 in the direction of the photosensitive tram 1.

押し当て部材１１・１１間の帯電ワイヤ１０はその有効
全長部が感光ドラム１而に対して圧接密着した状態に保
たれる。The entire effective length of the charging wire 10 between the pressing members 11 is kept in close contact with the photosensitive drum 1 under pressure.

帯電ワイヤ１０にはその導電性部材１０ａの一端側に電
源部９より接点８を介して電圧か印加され、交流電圧と
直流電圧を重畳して振動電圧が供給される。ここで振動
電圧とは時間とともに周期的に電圧埴が変化する電圧で
ある。更に詳【ノく云えば、好ましくは、感光体の帯電
開始電圧の２倍以上のピーク間電圧を有する交流電圧と
直流電圧とを重畳した電圧が印加される。A voltage is applied to one end of the conductive member 10a of the charging wire 10 from the power source 9 through the contact 8, and an oscillating voltage is supplied by superimposing an alternating current voltage and a direct current voltage. Here, the oscillating voltage is a voltage whose voltage level changes periodically over time. More specifically, preferably, a voltage that is a superimposition of an AC voltage and a DC voltage having a peak-to-peak voltage that is twice or more the charging start voltage of the photoreceptor is applied.

振動電圧の波形としては正弦波に限らず矩形波、三角波
、パルス波でもよい。また、直流電圧たけでも同様に被
帯電体の帯電処理が可能である。The waveform of the oscillating voltage is not limited to a sine wave, but may be a rectangular wave, a triangular wave, or a pulse wave. Further, the charging process of the charged object can be performed in the same manner using only a direct current voltage.

以上の構成に於て、感光トラム感光トラム１を周速４０
　ｍ　ｍ　／　ｓ　ｅ　ｃで回転させ、帯電ワイヤ１０
に電源９より一７００ｖの直流電圧と、ど−ク間電圧１
８００Ｖｐｐ、周波数２５０Ｈｚの交流電圧を印加した
ところ、感光体１ａ而は大略−７００Ｖに均一帯電し良
好な画像が出力された。In the above configuration, the photosensitive tram 1 is set at a circumferential speed of 40
Rotate at m m / sec and charge wire 10
DC voltage of -700V from power supply 9 and voltage 1 between
When an AC voltage of 800 Vpp and a frequency of 250 Hz was applied, the photoreceptor 1a was uniformly charged to about -700 V and a good image was output.

本実施例は帯電部材１０に印加する交流電圧のピーク間
電圧を、直流電圧のみ印加した時の被帯電体を帯電する
帯電開始電圧の２倍以上にする場合に応用した時に特に
効果か大きい。This embodiment is particularly effective when applied to the case where the peak-to-peak voltage of the AC voltage applied to the charging member 10 is more than twice the charging start voltage at which the object to be charged is charged when only the DC voltage is applied.

なお本実施例に於ては直流電圧のみ印加したときの帯電
開始電圧は一５６０ｖであった。In this example, the charging start voltage when only DC voltage was applied was -560V.

また帯電ローラや帯電ブレードの場合におけるような導
電性ゴム層からの滲出可塑剤に起因する画像流れの発生
、帯電部材の浮きによる部分的な帯電不良部の発生、帯
電音の発生等もなかった。In addition, unlike in the case of charging rollers and charging blades, there was no occurrence of image deletion due to plasticizer exuding from the conductive rubber layer, no occurrence of partial charging defects due to lifting of the charging member, and no occurrence of charging noise. .

また帯電ワイヤが感光ドラム感光ドラムに軽く当接して
いるだけの接触ワイヤ帯電では、感光ドラムに一定の圧
力で押しつけられてる帯電プレートの場合と異なり、画
像形成装置においてクリーニング装置６をくぐり抜けて
きたシリカやトナーなどがワイヤをすり抜けやすく、そ
の結果ワイヤに付着しにくいといった利点もある。In addition, in contact wire charging in which the charging wire is only lightly in contact with the photosensitive drum, unlike in the case of a charging plate that is pressed against the photosensitive drum with a constant pressure, silica that has passed through the cleaning device 6 in the image forming apparatus It also has the advantage that toner, etc. can easily pass through the wire and, as a result, are less likely to adhere to the wire.

ここで帯電音に関して次のような測定を行なフた。At this point, we performed the following measurements regarding charging noise.

本実施例において帯電ワイヤ１０の導電性部材１０ａに
対する電圧印加を前述のように一７００Ｖの直流電圧と
、ど−ク間電圧１５ｏｏｖｐｐ、周波数２５０Ｈｚの交
流電圧として、導電性部材１０ａの幅ｄ、即ち直径を大
小変化させたときの発生帯電音の変化を測定した。その
結果を第５図のグラフに示した。In this embodiment, the voltage applied to the conductive member 10a of the charging wire 10 is a DC voltage of -700 V as described above, an AC voltage of 15 oovpp and a frequency of 250 Hz, and the width d of the conductive member 10a, i.e. Changes in the generated charging sound were measured when the diameter was varied. The results are shown in the graph of FIG.

第５図のグラフにおいて、横軸は導電性部材の幅（直径
）ｄ、縦軸は発生帯電音の大きさ（ｄＢ）である。In the graph of FIG. 5, the horizontal axis is the width (diameter) d of the conductive member, and the vertical axis is the magnitude (dB) of the generated charging noise.

幅ｄが１０００μｍを越えると実質的な騒音界としての
５０ｄＢを越えてしまう。これは接触帯電部材に一般的
に印加されるピーク間電圧・周波数の交流電圧について
同様であった。If the width d exceeds 1000 μm, the actual noise field exceeds 50 dB. This was the same for the peak-to-peak voltage/frequency AC voltage that is generally applied to contact charging members.

この理由は次のように考えられる。つまり接触帯電では
、接触帯電部材に外部バイアスを印加すると接触帯電部
材が振動を始め、接触帯電部材と被帯電体との間に挟ま
っていた空気の流動で帯電音か発生するものと考えられ
る。しかし接触帯電部材が従来の太い接触帯電ローラの
場合と異なり、本実施例の帯電ワイヤ１０のように細く
、それが細くなればなるほど接触帯電部材１０と被帯電
体１との両者の間に挟まる空気がほとんど無くなるため
、発生帯ｔ　ｆが低下していくものと考えられる。The reason for this is thought to be as follows. In other words, in contact charging, when an external bias is applied to the contact charging member, the contact charging member begins to vibrate, and it is thought that charging noise is generated due to the flow of air caught between the contact charging member and the object to be charged. However, unlike the conventional thick contact charging roller, the contact charging member is thin like the charging wire 10 of this embodiment, and the thinner it is, the more it is caught between the contact charging member 10 and the object to be charged 1. It is thought that the generation zone t f decreases because almost no air is present.

しかじ幅ｄをあまり小さくし４μｍ以下にすると、今度
は帯電部分の面積が小さくなるので帯電抵抗が大きくな
り、帯電不良が発生するようになり、表１のように出力
画像が恋化する。If the width d is made too small to 4 μm or less, the area of the charged portion becomes smaller, the charging resistance increases, and charging defects occur, causing the output image to become distorted as shown in Table 1.

表　　１ ○：良　　　　△・Ｘ：不良 このような測定から、電圧を印加した導電性部材を直接
に又は抵抗部材を介して被帯電体に当接させて被帯電体
面の帯電を行なう場合には導電性部材の被帯電体に対す
る対向部の幅ｄを５μｍ＜ｄ＜１０００μｍに設定する
ことて発生歪電音を実用上許容限界内にすることが可能
であることがわかった。Table 1 ○: Good △・X: Bad From these measurements, when charging the surface of a charged object by bringing a conductive member to which a voltage is applied into contact with the charged object directly or through a resistive member, It has been found that by setting the width d of the portion of the conductive member facing the object to be charged to 5 .mu.m<d<1000 .mu.m, it is possible to bring the generated distorted electric noise within the practically acceptable limits.

なお導電性部材１０ａに被覆層１０ｂ（抵抗部材）を設
ける場合にはその厚みか幅ｄに関与しないこともないか
、その厚みは一般に薄く実質的に導電性部材１０ａの幅
ｄを前記のように規定することで足りる。むしろ被覆層
１０ｂが′介在すると該被覆層１０ｂのクツション性が
帯電音を減少させる方向に働く。Note that when the coating layer 10b (resistance member) is provided on the conductive member 10a, its thickness or width d may not be affected, or the thickness is generally thin and the width d of the conductive member 10a is substantially the same as described above. It is sufficient to specify. Rather, when the covering layer 10b is present, the cushioning properties of the covering layer 10b act to reduce charging noise.

〈実施例２〉（第６図） 本例は帯電ワイヤ１０を前述実施例１の場合の１本に対
して２本配設したものである。２本の帯電ワイヤｌ０Ａ
−１０Ｂは押し当て部材１１により互いに略並行に被帯
電体としての感光ドラム１面にドラム母線に略並行に圧
接され、どちらにも電圧が印加される。<Embodiment 2> (FIG. 6) In this example, two charging wires 10 are provided in place of one in the case of the first embodiment. Two charging wires l0A
-10B are pressed approximately parallel to each other by the pressing member 11 to the surface of the photosensitive drum as a charged member approximately parallel to the drum bus line, and a voltage is applied to both.

このように帯電ワイヤを２本以上複数本とすることによ
り１本の場合よりも確実な帯電性か得られる。仮に１本
の帯電ワイヤに異物か付着したり、断線しても残りの帯
電ワイヤで帯電を確実に続行させることができる。By using two or more charging wires in this way, more reliable charging performance can be obtained than when using only one charging wire. Even if a foreign object adheres to one charging wire or the wire is broken, charging can be reliably continued using the remaining charging wires.

この場合は、個々の帯電ワイヤＩＯＡ・ＩＯＢ・・・は
導電性部材１０ａの幅ｄを前記の規定範囲に設定するこ
とで個々の帯電ワイヤの発生歪電音は小さくなるが、合
計で大きな帯電音となることもあるから、各帯電ワイヤ
の導電性部材の合計幅が前記の規定範囲に納まるものと
なるようにするのがよい。In this case, by setting the width d of the conductive member 10a within the specified range for each charging wire IOA, IOB, etc., the distorted sound generated by each charging wire will be reduced, but the total charging will be large. Since this may result in noise, it is preferable that the total width of the conductive members of each charging wire falls within the above-mentioned specified range.

〈実施例３〉（第７図） 接触帯電部材１０は第７図（Ａ）や同図（Ｂ）に横断面
図を示したように、１本或いは複数本の導電性部材１０
ａを抵抗部材１０ｂの肉厚内に埋設した形態の両部材１
０ａ・１０ｂの一体成型体とすることもてき、量産性が
あり、低コスト化が図れるメリットがある。<Example 3> (FIG. 7) The contact charging member 10 is composed of one or more conductive members 10, as shown in cross-sectional views in FIGS. 7(A) and 7(B).
Both members 1 are embedded in the thickness of the resistance member 10b.
It is also possible to form an integrally molded body of 0a and 10b, which has the advantage of being mass-producible and reducing costs.

〈実施例４〉（第８図） この実施例は接触帯電部材１０を第８図に横断面図を示
したように、導電性部材１０ａとして幅ｄ＝６０μｍの
横断面矩形のフラットワイヤを用い、これをモルトブレ
ン等の横長のクツション材１０ｃの下面に添設し、該フ
ラットワイヤ１０ａを添設したクツション材１０ｃの下
面を全面的に抵抗部材としてのカーボン人すのテフロン
（商品名、エムラロン、日本アジソン社）等の高抵抗材
料で被覆１０ｂし、この被覆層ｉｏｂとは反対側のクツ
ション材１０ｃの上面に剛体製の押し当て板１０ｄを設
けた形態のものとしたものである。<Embodiment 4> (FIG. 8) In this embodiment, as shown in the cross-sectional view of the contact charging member 10 in FIG. , this is attached to the lower surface of a horizontally long cushioning material 10c such as maltbrene, and the lower surface of the cushioning material 10c to which the flat wire 10a is attached is entirely covered with carbon fiber Teflon (trade name: Emlaron) as a resistance member. The cushioning material 10b is coated with a high-resistance material such as Nippon Addison Co., Ltd., and a rigid pressing plate 10d is provided on the upper surface of the cushioning material 10c on the opposite side from the coating layer iob.

被帯電体としての感光ドラム１面に対して上記の接触帯
電部材１０を抵抗部材である被覆層１０ｂ側を対面させ
てクツション材ｆｏｃの弾性に抗して適度に押し付は状
態にして保持させ、導電性部材１０ａに対して電圧を印
加する。The above-mentioned contact charging member 10 is held with the coating layer 10b, which is a resistance member, facing the surface of the photosensitive drum as the object to be charged, and is pressed appropriately against the elasticity of the cushion material foc. , a voltage is applied to the conductive member 10a.

導電性部材１０ａがｄ＝直径６０μｍの横断面丸形ワイ
ヤである場合に比べて幅６０μｍのフラットワイヤを用
いた場合には感光ドラムに対向する実効幅ないしは実効
面積か増えて、即ち帯電幅が増えて帯電能力が増加する
効果かある。When a flat wire with a width of 60 μm is used as the conductive member 10a compared to a wire with a round cross section and a diameter of d=60 μm, the effective width or effective area facing the photosensitive drum increases, that is, the charging width increases. This has the effect of increasing the charging capacity.

またクツション部材１０ｃか存在することで帯電音の発
生か低減される効果かある。Furthermore, the presence of the cushion member 10c has the effect of reducing the generation of charging noise.

〈実施例５〉（第９図） この実施例は接触帯電部材１０を第９図に横断面を示し
たように、導電性部材１０ａとしてリン青銅やＳＵＳ等
の厚さｄ＝６０μｍの導電性薄板材を用い、これにトレ
ジン等の抵抗材料を厚さ１００μｍ程度に塗布して被覆
したものとしたものである。<Example 5> (FIG. 9) In this example, as shown in the cross section of the contact charging member 10 in FIG. A thin plate material is used and coated with a resistive material such as resin to a thickness of about 100 μm.

この接触帯電部材１０をそのエツジ部を被帯電体として
の感光トラム１に押圧接触させ、導電性部材１０ａに電
圧を印加する。The edge portion of the contact charging member 10 is pressed into contact with the photosensitive tram 1 as a charged object, and a voltage is applied to the conductive member 10a.

接触帯電部材１０が線材である場合と興なり、押え部材
が必要ないという利点がある。When the contact charging member 10 is a wire rod, there is an advantage that no presser member is required.

（発明の効果） 以Ｆのように本発明に依れば、接触帯電方式の帯電装置
について発生帯電音を低減もしくは実質的になくするこ
とかでき、所期の目的かよく達成される。(Effects of the Invention) As described in F below, according to the present invention, the charging noise generated in a contact charging type charging device can be reduced or substantially eliminated, and the intended purpose is well achieved.

【図面の簡単な説明】[Brief explanation of the drawing]

第１図は第１の実施例装置の側面図。 第２図のその平面図。 第３図はその斜視図。 第４図＜ａ＞乃至同図（１）は接触帯電ワイヤの各種拡
大横断面図。 第５図は導電性部材の幅（直径）ｄと帯電音の大きさｄ
Ｂの測定。 第６図は第２の実施例装置の要部の横断面図。 第７図（Ａ）・（Ｂ）は夫々第３の実施例装置の要部の
横断面図。 第８図は第４の実施例装置の要部の横断面図。 第９図は第５の実施例装置の要部の横断面図。 第１０図は帯電ローラな用いた画像形成装置例の概略図
。 １は被帯電体としての感光トラム、１０・１０Ａ・ＩＯ
Ｂは接触帯電部材、１０ａは導電性部材、Ｊｏｂは抵抗
部材、９は外部電源。 ノ 茅 図 茅 Ａ 図FIG. 1 is a side view of the device of the first embodiment. The plan view of FIG. 2. FIG. 3 is a perspective view thereof. FIG. 4<a> to FIG. 4(1) are various enlarged cross-sectional views of the contact charging wire. Figure 5 shows the width (diameter) d of the conductive member and the magnitude d of the charging sound.
Measurement of B. FIG. 6 is a cross-sectional view of the main parts of the device of the second embodiment. FIGS. 7(A) and 7(B) are cross-sectional views of essential parts of the third embodiment apparatus, respectively. FIG. 8 is a cross-sectional view of the main parts of the device of the fourth embodiment. FIG. 9 is a cross-sectional view of the main parts of the device of the fifth embodiment. FIG. 10 is a schematic diagram of an example of an image forming apparatus using a charging roller. 1 is a photosensitive tram as a charged object, 10.10A.IO
B is a contact charging member, 10a is a conductive member, Job is a resistance member, and 9 is an external power source. Kaya illustration Kaya A

Claims (1)

【特許請求の範囲】[Claims] （１）電圧を印加した導電性部材を直接に又は抵抗部材
を介して被帯電体に当接させて被帯電体面の帯電を行な
う接触式の帯電装置であり、前記導電性部材の被帯電体
に対する対向部の幅ｄを５μｍ＜ｄ＜１０００μｍに設
定したことを特徴とする帯電装置。(1) A contact-type charging device that charges the surface of the charged object by bringing a conductive member to which a voltage is applied into contact with the charged object directly or through a resistive member, and the charged object of the conductive member A charging device characterized in that the width d of the opposing portion is set to 5 μm<d<1000 μm.