JP2003316119A - Charging member, charging device, and image forming unit and image forming apparatus using them - Google Patents
Charging member, charging device, and image forming unit and image forming apparatus using themInfo
- Publication number
- JP2003316119A JP2003316119A JP2002117895A JP2002117895A JP2003316119A JP 2003316119 A JP2003316119 A JP 2003316119A JP 2002117895 A JP2002117895 A JP 2002117895A JP 2002117895 A JP2002117895 A JP 2002117895A JP 2003316119 A JP2003316119 A JP 2003316119A
- Authority
- JP
- Japan
- Prior art keywords
- charging
- image carrier
- charging member
- image forming
- image
- 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.)
- Granted
Links
Landscapes
- Photoreceptors In Electrophotography (AREA)
- Electrostatic Charge, Transfer And Separation In Electrography (AREA)
Abstract
Description
【０００１】[0001]
【発明の属する技術分野】本発明は、電子写真方式の複
写機、ファクシミリ、プリンタ等の画像形成装置に配設
される帯電部材、帯電装置、像担持体とこの帯電装置を
有する作像ユニットと、この帯電装置を有する画像形成
装置に関するものである。さらに詳細には、像担持体表
面に対向して配設され、かつ像担持体に対して微少な間
隙を有する帯電部材、これを配設する帯電装置、さらに
これらを備える作像ユニット、画像形成装置に関するも
のである。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a charging member, a charging device, an image carrier provided in an image forming apparatus such as an electrophotographic copying machine, a facsimile and a printer, and an image forming unit having the charging device. The present invention relates to an image forming apparatus having this charging device. More specifically, a charging member that is disposed so as to face the surface of the image carrier and has a minute gap with respect to the image carrier, a charging device that disposes the charging member, an image forming unit including these, and an image forming unit. It relates to the device.
【０００２】[0002]
【従来の技術】電子写真方式の画像形成装置は、像担持
体に帯電を施し、その帯電を露光より選択的に消去ある
いは減少させ、像担持体上に静電潜像を形成するものが
知られている。そして、像担持体に帯電する帯電装置と
しては、コロナ放電を利用したものが主流であった。し
かし、このコロナ放電を用いた帯電装置は、オゾンが多
量に発生してしまうという不具合があり、またコロナ放
電を行わせるために５〜１０ｋＶという高電圧を印加す
る高電圧電源が必要となり、画像形成装置の低コスト化
が難しくなる。従って、近年、コロナ放電を利用しない
帯電部材を像担持体に対向して設ける帯電装置が提案さ
れている。この帯電装置は、像担持体と直接接触させる
接触型と微少な間隙を設ける非接触型とがある。接触型
の帯電装置では、コロナ放電を用いる場合の不具合の多
くが解消される一方、「像流れ」と呼ばれる異常画像の
発生及び像担持体の摩耗量が増大する等の不具合が発生
している。また、印加電圧に交流を用いた場合は騒音が
発生するという不具合がある。さらに、接触型帯電装置
では、トナーや紙粉を像担持体と帯電部材で擦りつける
ので汚染を助長するという不具合がある。2. Description of the Related Art An electrophotographic image forming apparatus is known which forms an electrostatic latent image on an image bearing member by charging the image bearing member and selectively erasing or reducing the charging by exposure. Has been. As the charging device for charging the image bearing member, the one using corona discharge has been the mainstream. However, the charging device using this corona discharge has a drawback that a large amount of ozone is generated, and a high voltage power source for applying a high voltage of 5 to 10 kV is required to perform the corona discharge. It becomes difficult to reduce the cost of the forming apparatus. Therefore, in recent years, a charging device has been proposed in which a charging member that does not utilize corona discharge is provided facing the image carrier. This charging device is classified into a contact type that directly contacts the image carrier and a non-contact type that provides a minute gap. In the contact type charging device, while many of the problems when using corona discharge are solved, problems such as occurrence of abnormal image called "image deletion" and increase of wear amount of the image carrier occur. . Further, there is a problem that noise is generated when an alternating current is used as the applied voltage. Further, in the contact type charging device, toner and paper dust are rubbed between the image bearing member and the charging member, which causes a problem of promoting contamination.
【０００３】そのために、非接触型で像担持体を帯電さ
せる帯電装置が多く提案されている。この非接触型の帯
電装置では、接触型の帯電装置と比較して、帯電部材が
像担持体に機械的に当接しないために、互いに摩耗する
ことが無く、さらに、トナー又は紙粉等による汚れるこ
とが少ないために、経時劣化を防止することができる。Therefore, many non-contact type charging devices for charging the image bearing member have been proposed. In this non-contact type charging device, compared with the contact type charging device, since the charging member does not mechanically contact the image carrier, they do not wear each other, and further, due to toner or paper dust. Since it is less likely to get dirty, deterioration over time can be prevented.
【０００４】また、従来、所定の間隙にするために、帯
電部材の両端にスペーサ部材を接着剤で貼着させている
が、この接着剤が圧力を受けてスペーサ部材から染み出
してくることがある。この染み出した接着剤にトナー等
が付着して異常生成物を形成すると、異常放電が発生し
て像担持体、帯電部材の劣化を招くことになる。また、
異常放電により像担持体が正常に帯電しないために画像
斑等の異常画像が形成されることがある。Conventionally, spacer members are adhered to both ends of the charging member with an adhesive in order to form a predetermined gap. However, this adhesive may be exuded from the spacer member under pressure. is there. When toner or the like adheres to the exuded adhesive to form an abnormal product, abnormal discharge occurs and the image carrier and the charging member are deteriorated. Also,
An abnormal image such as image spots may be formed because the image carrier is not charged normally due to abnormal discharge.
【０００５】[0005]
【発明が解決しようとする課題】そこで、本発明は、上
記問題点に鑑みてなされたものであり、その課題は、圧
力が加えられても像担持体と帯電部材とが形成する間隙
の変動が少なく、帯電部材からの放電生成物と異常生成
物を少なくすることができる帯電部材を提供することで
ある。さらに、この帯電部材を配設することで、像担持
体と帯電部材とが形成する間隙の変動を少なくして像担
持体の帯電を均一にすることができる帯電装置を提供す
ることである。また、この帯電装置を用いることで帯電
装置を交換するための期間を長くした高寿命の作像ユニ
ットを提供することである。また、この帯電装置を用い
ることで、放電生成物を形成することが少なくなるため
に、異常画像の少ない高品位の画像を得ることができる
画像形成装置を提供することである。Therefore, the present invention has been made in view of the above problems, and the problem is that the gap between the image carrier and the charging member varies even when pressure is applied. It is an object of the present invention to provide a charging member capable of reducing discharge products and abnormal products from the charging member. Further, by disposing this charging member, it is possible to provide a charging device capable of uniforming the charging of the image carrier by reducing the fluctuation of the gap formed by the image carrier and the charging member. Another object of the present invention is to provide a long-life image forming unit in which the period for replacing the charging device is extended by using this charging device. Another object of the present invention is to provide an image forming apparatus capable of obtaining a high-quality image with few abnormal images because the use of this charging device reduces the formation of discharge products.
【０００６】[0006]
【課題を解決するための手段】上記課題を解決するため
に、請求項１に記載の発明は、帯電装置に配設される帯
電部材であって、像担持体に対向して配置されて、像担
持体表面を帯電させる帯電部材において、前記帯電部材
は、軸部と軸部を被覆する本体部とから構成され、像担
持体の画像形成領域外に対応する本体部に収縮性を有す
るスペーサ部材を設けて、像担持体と帯電部材との間で
間隙を形成する帯電部材とする。請求項２に記載の発明
は、前記帯電部材は、像担持体の画像形成領域外に対応
する部分であって、端部より内側に段差を有する請求項
１に記載の帯電部材とする。請求項３に記載の発明は、
前記帯電部材は、円柱形状で、回転可能に配設される請
求項１又は２に記載の帯電部材とする。請求項４に記載
の発明は、前記本体部は、導電剤を含む樹脂から構成さ
れる請求項１ないし３のいずれかに記載の帯電部材とす
る。請求項５に記載の発明は、前記スペーサ部材は、切
れ目を有しない請求項１ないし４のいずれかに記載の帯
電部材とする。請求項６に記載の発明は、前記スペーサ
部材は、熱又は光により収縮する請求項１ないし５のい
ずれかに記載の帯電部材とする。請求項７に記載の発明
は、前記スペーサ部材は、弾性により収縮する請求項１
ないし５のいずれかに記載の帯電部材とする。請求項８
に記載の発明は、前記スペーサ部材は、弾性を有するゴ
ム製である請求項７に記載の帯電部材とする。請求項９
に記載の発明は、前記スペーサ部材は、弾性を有する金
属製である請求項８に記載の帯電部材とする。請求項１
０に記載の発明は、前記スペーサ部材は、接着剤なしで
前記本体部に固定される請求項１ないし９のいずれかに
記載の帯電部材とする。請求項１１に記載の発明は、前
記スペーサ部材は、帯電部材より硬度が低い請求項１な
いし８、１０のいずれかに記載の帯電部材とする。In order to solve the above-mentioned problems, the invention according to claim 1 is a charging member arranged in a charging device, the charging member being arranged so as to face an image carrier. In a charging member for charging the surface of an image carrier, the charging member is composed of a shaft portion and a main body portion covering the shaft portion, and a spacer having contractibility in the main body portion outside the image forming area of the image carrier. The charging member is provided with a member to form a gap between the image carrier and the charging member. The invention according to claim 2 is the charging member according to claim 1, wherein the charging member is a portion corresponding to the outside of the image forming area of the image carrier and has a step inside the end portion. The invention according to claim 3 is
The charging member according to claim 1, wherein the charging member has a cylindrical shape and is rotatably arranged. The invention according to claim 4 is the charging member according to any one of claims 1 to 3, wherein the main body portion is made of a resin containing a conductive agent. According to a fifth aspect of the present invention, the spacer member is the charging member according to any one of the first to fourth aspects, which has no cut. The invention according to claim 6 is the charging member according to any one of claims 1 to 5, wherein the spacer member is contracted by heat or light. In the invention according to claim 7, the spacer member contracts by elasticity.
The charging member according to any one of 1 to 5. Claim 8
The invention according to claim 8 is the charging member according to claim 7, wherein the spacer member is made of rubber having elasticity. Claim 9
The invention according to claim 8 is the charging member according to claim 8, wherein the spacer member is made of a metal having elasticity. Claim 1
The invention described in 0 is the charging member according to any one of claims 1 to 9, wherein the spacer member is fixed to the main body portion without an adhesive. An eleventh aspect of the present invention is the charging member according to any one of the first to eighth and tenth aspects, wherein the spacer member has a hardness lower than that of the charging member.
【０００７】請求項１２に記載の発明は、像担持体に対
向し、像担持体表面を帯電させる帯電部材を配設する帯
電装置において、前記帯電部材は、軸部と軸部を被覆す
る本体部とから構成され、かつ 像担持体の画像形成領
域外に対応する本体部に収縮性を有するスペーサ部材を
設けて、像担持体と帯電部材との間で間隙を形成する帯
電装置とする。請求項１３に記載の発明は、前記帯電部
材は、端部より内側であって、像担持体の画像形成領域
外に対応する部分に段差を有する請求項１２に記載の帯
電装置とする。請求項１４に記載の発明は、前記帯電部
材と前記像担持体の間で形成される間隙は、接触しない
距離であって、８０μｍ以下である請求項１２又は１３
に記載の帯電装置とする。請求項１５に記載の発明は、
前記帯電部材は、スペーサ部材で像担持体に接触し、前
記スペーサ部材は、４〜２５Ｎの荷重で像担持体に対し
て押圧され、かつ、スペーサ部材の像担持体表面の移動
する円周方向における接触幅を０．５ｍｍ以下にする請
求項１２ないし１４のいずれかに記載の帯電装置とす
る。請求項１６に記載の発明は、前記帯電部材は、請求
項４から１１のいずれかに記載の帯電部材である請求項
１２ないし１５のいずれかに記載の帯電装置とする。請
求項１７に記載の発明は、少なくとも帯電装置を配設す
る作像ユニットであって、画像形成装置本体に着脱可能
な作像ユニットであって、前記作像ユニットの帯電装置
は、像担持体に対向して配置されて、像担持体表面を帯
電させる帯電部材を配設する作像ユニットにおいて、前
記帯電部材は、軸部と軸部を被覆する本体部とから構成
され、かつ 像担持体の画像形成領域外に対応する本体
部にスペーサ部材を設けて像担持体と間隙を形成する作
像ユニットとする。請求項１８に記載の発明は、前記作
像ユニットの帯電部材は、請求項１ないし１１のいずれ
かに記載の帯電部材である作像ユニットとする。請求項
１９に記載の発明は、前記作像ユニットは、現像装置及
び／又はクリーニング装置を配設する請求項１７又は１
８に記載の作像ユニットとする。請求項２０に記載の発
明は、帯電装置と像担持体の一部に当接して位置決めす
る当接部材を備える請求項１７ないし１９のいずれかに
記載の作像ユニットとする。According to a twelfth aspect of the present invention, in a charging device provided with a charging member facing the image carrier and charging the surface of the image carrier, the charging member has a shaft portion and a main body covering the shaft portion. And a contracting spacer member is provided in the main body portion corresponding to the outside of the image forming area of the image carrier to form a gap between the image carrier and the charging member. A thirteenth aspect of the present invention is the charging device according to the twelfth aspect, wherein the charging member has a step at a portion inside the end portion and outside the image forming area of the image carrier. According to a fourteenth aspect of the present invention, the gap formed between the charging member and the image bearing member is a distance at which the charging member and the image bearing member do not come into contact with each other and is 80 μm or less.
The charging device described in 1. The invention according to claim 15 is
The charging member is in contact with the image carrier by a spacer member, the spacer member is pressed against the image carrier by a load of 4 to 25 N, and the surface of the image carrier of the spacer member moves in the circumferential direction. The charging device according to any one of claims 12 to 14, wherein the contact width in (5) is 0.5 mm or less. The invention according to claim 16 is the charging device according to any one of claims 12 to 15, wherein the charging member is the charging member according to any one of claims 4 to 11. The invention according to claim 17 is an image forming unit in which at least a charging device is provided, and the image forming unit is attachable to and detachable from a main body of the image forming apparatus, wherein the charging device of the image forming unit is an image carrier. In the image forming unit, which is arranged so as to face the image carrier, and which is provided with a charging member for charging the surface of the image carrier, the charging member includes a shaft portion and a main body portion covering the shaft portion, and the image carrier In the image forming unit, a spacer member is provided on the main body portion corresponding to the outside of the image forming area to form a gap with the image carrier. An eighteenth aspect of the present invention is an image forming unit in which the charging member of the image forming unit is the charging member according to any one of the first to eleventh aspects. A nineteenth aspect of the present invention is that the image forming unit includes a developing device and / or a cleaning device.
The image forming unit described in 8. According to a twentieth aspect of the present invention, there is provided the image forming unit according to any one of the seventeenth to nineteenth aspects, which includes a charging device and an abutting member that abuts and positions a part of the image carrier.
【０００８】請求項２１に記載の発明は、少なくとも像
担持体、帯電装置、現像装置を配設する画像形成装置で
あって、前記画像形成装置の帯電装置は、像担持体に対
向して配置されて、像担持体表面を帯電させる帯電部材
を配設する画像形成装置において、前記帯電部材は、軸
部と軸部を被覆する本体部とから構成され、かつ 像担
持体の画像形成領域外に対応する本体部にスペーサ部材
を設けて像担持体と間隙を形成する画像形成装置とす
る。請求項２２に記載の発明は、前記画像形成装置の帯
電部材は、請求項１ないし１１のいずれかに記載の帯電
部材である画像形成装置とする。請求項２３に記載の発
明は、前記画像形成装置において、前記像担持体は、ア
モルファスシリコンを光導電体として用いる請求項２１
又は２２に記載の画像形成装置とする。請求項２４に記
載の発明は、前記画像形成装置において、前記像担持体
は、有機光導電体を用い、フィラーを分散させる表面層
を有する請求項２１又は２２に記載の画像形成装置とす
る。According to a twenty-first aspect of the present invention, there is provided an image forming apparatus including at least an image carrier, a charging device and a developing device, wherein the charging device of the image forming device is arranged so as to face the image carrier. In the image forming apparatus having the charging member for charging the surface of the image carrier, the charging member includes a shaft portion and a main body portion covering the shaft portion, and is outside the image forming area of the image carrier. In the image forming apparatus, a spacer member is provided on the main body corresponding to the above, and a gap is formed with the image carrier. A twenty-second aspect of the invention is an image forming apparatus in which the charging member of the image forming apparatus is the charging member according to any one of the first to eleventh aspects. A twenty-third aspect of the invention is the image forming apparatus, wherein the image carrier uses amorphous silicon as a photoconductor.
Alternatively, the image forming apparatus according to item 22 is used. According to a twenty-fourth aspect of the present invention, in the image forming apparatus according to the twenty-first aspect, the image carrier is an organic photoconductor and has a surface layer in which a filler is dispersed.
【０００９】[0009]
【発明の実施の形態】以下に、本発明の実施の形態を図
面に基づいて説明する。図１は、本発明の帯電部材、本
発明の帯電装置を用いる画像形成装置である本発明の画
像形成装置の構成を示す概略図である。図２は、図１の
画像形成装置の画像形成部の構成を示す概略図である。
この画像形成装置１は、表面に感光体層を有するドラム
状であってイエロー（Ｙ）、マゼンタ（Ｍ）、シアン
（Ｃ）、ブラック（Ｋ）の４色に対応する分の個数分の
像担持体６１と、各像担持体６１をほぼ一様に帯電する
帯電装置１００と、帯電された像担持体６１にレーザ光
で露光して静電潜像を形成する露光装置７０と、イエロ
ー、マゼンタ、シアン、ブラックの４色の現像剤を収容
し、像担持体６１上の静電潜像に対応するトナー像を形
成する現像装置６３と、像担持体６１上のトナー像を転
写する１次転写装置６２と、像担持体６１上のトナー像
が転写されるベルト状の中間転写体５０と、中間転写体
５０のトナー像を転写する２次転写装置５１と、中間転
写体５０のトナー像が転写される記録媒体上のトナー像
を定着させる定着装置８０と、さらに、像担持体６１上
に転写後残留するトナーを除去するクリーニング装置６
４とを備える。記録媒体は、記録媒体を収納する給紙装
置２１、２２のひとつから、１枚ずつ搬送経路を搬送ロ
ーラでレジストローラ２３まで搬送され、ここで、像担
持体６１上のトナー像と同期を計って転写位置に搬送さ
れる。BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a schematic view showing a configuration of an image forming apparatus of the present invention which is an image forming apparatus using the charging member of the present invention and the charging device of the present invention. FIG. 2 is a schematic diagram showing the configuration of the image forming unit of the image forming apparatus of FIG.
The image forming apparatus 1 has a drum-like shape having a photoconductor layer on the surface thereof, and has a number of images corresponding to four colors of yellow (Y), magenta (M), cyan (C), and black (K). A carrier 61, a charging device 100 that charges each image carrier 61 substantially uniformly, an exposure device 70 that exposes the charged image carrier 61 with a laser beam to form an electrostatic latent image, and a yellow device. A developing device 63 that contains four color developers of magenta, cyan, and black and forms a toner image corresponding to the electrostatic latent image on the image carrier 61, and a toner image on the image carrier 61 are transferred 1 A secondary transfer device 62, a belt-shaped intermediate transfer member 50 onto which the toner image on the image carrier 61 is transferred, a secondary transfer device 51 that transfers the toner image on the intermediate transfer member 50, and toner on the intermediate transfer member 50. A fixing device for fixing the toner image on the recording medium onto which the image is transferred. 80, further, a cleaning apparatus for removing toner remaining after transfer on the image carrier 61 6
4 and. The recording medium is conveyed sheet by sheet from one of the sheet feeding devices 21 and 22 for accommodating the recording medium to the registration roller 23 by the conveying roller, and here, the recording medium is synchronized with the toner image on the image carrier 61. Are conveyed to the transfer position.
【００１０】ここで、帯電装置１００について詳細に説
明する。図３は、本発明の帯電装置の構成を示す概略図
である。図４は、本発明の帯電部材と像担持体との位置
関係を示す概略図である。帯電装置１００は、像担持体
６１に対向し、微少な間隙Ｇを設けて配設される帯電部
材１０１と、帯電部材を清掃する不図示のクリーニング
部材１０２と、帯電部材１０１に電圧を印加する不図示
の電源と、帯電部材１０１を像担持体に６１に加圧して
接触させる加圧スプリング１０５とを少なくとも備え
る。帯電部材１０１は、図３及び図４に示すように、像
担持体６１に微少な間隙Ｇを持たせて対向して配設され
る。帯電部材１０１と像担持体６１の間隙Ｇは、一定の
厚さを有するスペーサ部材１０３を帯電部材１０１の非
画像形成領域に貼着させて調整する。また、スペーサ部
材１０３は、像担持体６１と移動する円周方向に対して
接触幅Ｗをもって接触している。図５は、本発明の帯電
部材の構造を示す概略図である。図５に示すように、帯
電部材１０１の本体部の両端に、段差１０１ｅが設けら
れ、この段差１０１ｅにスペーサ部材１０３を巻き付け
る。例えば、この段差１０１ｅとしては、図５（Ａ）に
示すように、帯電部材１０１本体部１０１ｂの端部に段
差１０１ｅがある。図５（Ｂ）に示すように、帯電部材
１０１本体部１０１ｂの端部内側に段差１０１ｅがあ
り、スペーサ部材１０３を両側から挟むような状態にな
っている。さらに、図５（Ｃ）に示すように、帯電部材
１０１本体部１０１ｂの端部に段差１０１ｅがあり、こ
の段差１０１ｅに別の部材１０１ｆを設けられている。
これにより、帯電部材１０１の端部に段差１０１ｅがあ
っても、スペーサ部材１０３を両側から挟むことで、ス
ペーサ部材１０３の変動を抑えることができる。Here, the charging device 100 will be described in detail. FIG. 3 is a schematic diagram showing the configuration of the charging device of the present invention. FIG. 4 is a schematic view showing the positional relationship between the charging member and the image carrier of the present invention. The charging device 100 faces the image carrier 61 and is provided with a minute gap G, a charging member 101, a cleaning member 102 (not shown) that cleans the charging member, and a voltage is applied to the charging member 101. At least a power source (not shown) and a pressure spring 105 that presses the charging member 101 against the image carrier 61 to contact the image carrier 61 are provided. As shown in FIGS. 3 and 4, the charging member 101 is disposed so as to face the image carrier 61 with a minute gap G. The gap G between the charging member 101 and the image carrier 61 is adjusted by attaching the spacer member 103 having a constant thickness to the non-image forming area of the charging member 101. The spacer member 103 is in contact with the image carrier 61 with a contact width W in the circumferential direction. FIG. 5 is a schematic view showing the structure of the charging member of the present invention. As shown in FIG. 5, steps 101e are provided at both ends of the main body of the charging member 101, and the spacer member 103 is wound around the steps 101e. For example, as the step 101e, as shown in FIG. 5A, there is a step 101e at the end of the main body 101b of the charging member 101. As shown in FIG. 5B, there is a step 101e inside the end of the charging member 101 body 101b, and the spacer member 103 is sandwiched from both sides. Further, as shown in FIG. 5C, there is a step 101e at the end of the charging member 101 body 101b, and another member 101f is provided on this step 101e.
Accordingly, even if there is a step 101e at the end of the charging member 101, it is possible to suppress the variation of the spacer member 103 by sandwiching the spacer member 103 from both sides.
【００１１】また、図６は、本発明の帯電部材にスペー
サ部材を巻き付けた状態を示す概略構成図である。図６
（Ａ）は、帯電部材の端部に段差にスペーサ部材を巻き
付けた状態を示し、図６（Ｂ）は、帯電部材の端部内側
に段差にスペーサ部材を巻き付けた状態を示し、図６
（Ｃ）は、帯電部材の端部に段差にスペーサ部材を巻き
付け、その側面を別の部材で挟んだ状態を示している。
スペーサ部材１０３は、像担持体６１と接触して加圧さ
れているため、像担持体６１の回転に伴って、移動する
ことがある。このために、段差１０１ｅにスペーサ部材
１０３を接着剤で貼着して固定する。従来は、凸状又は
帯電部材１０１表面に直接スペーサ部材を接着剤で貼着
していたことで、接着剤が染み出して、これに像担持体
６１の表面のトナー、紙粉等の異物が付着して、異常生
成物になり、これが次第に大きくなりこの異常生成物の
箇所で異常放電が発生して、像担持体６１上に斑点状の
静電潜像を形成して、異常画像が形成されることがあっ
た。しかし、段差１０１ｅにしたことで、図６（Ａ）に
示すように、この間隙Ｇを調整するためのスペーサ部材
１０３の底部は段差１０１ｅにあり、ここから接着剤が
染み出しても、像担持体６１との距離が離れているため
に、異常放電を抑えることができる。また、図６（Ｂ）
に示すように、段差１０１ｅは、帯電部材１０１端部よ
り内側に設けても良いし、図６（Ｃ）に示すように、段
差１０１ｅが帯電部材１０３の端部にある場合でも、そ
の側面を別の部材１０１ｆで抑えて、挟んでも良い。ス
ペーサ部材１０３の接着剤が少ない場合に帯電部材１０
１の回転によりスペーサ部材１０３は左右に移動した
り、剥がれることがある。しかし、図６（Ｂ）及び図６
（Ｃ）に示すように、段差１０１ｅにすることで、像担
持体６１に接触していることによる圧力を受けても、ス
ペーサ部材１０３の変位を防止し、帯電部材１０１の間
隙Ｇを適正な範囲に維持することができ、異常放電を抑
え、異常画像が形成されるのを防止することができる。FIG. 6 is a schematic diagram showing a state in which a spacer member is wound around the charging member of the present invention. Figure 6
6A shows a state in which the spacer member is wound around the step on the end portion of the charging member, and FIG. 6B shows a state in which the spacer member is wrapped around the step inside the end portion of the charging member.
(C) shows a state in which the spacer member is wound around the end portion of the charging member in a stepped manner, and the side surface thereof is sandwiched by another member.
Since the spacer member 103 is in contact with the image carrier 61 and is pressurized, the spacer member 103 may move as the image carrier 61 rotates. For this purpose, the spacer member 103 is attached and fixed to the step 101e with an adhesive. Conventionally, since the spacer member is directly adhered to the surface of the convex or charging member 101 with an adhesive, the adhesive oozes out and foreign matter such as toner and paper dust on the surface of the image carrier 61 is spilled on the adhesive. Adhesion results in abnormal products, which gradually increase and abnormal discharge occurs at the locations of these abnormal products to form spotted electrostatic latent images on the image carrier 61, forming abnormal images. I was sometimes told. However, because of the step 101e, the bottom of the spacer member 103 for adjusting the gap G is at the step 101e as shown in FIG. Since the distance from the body 61 is large, abnormal discharge can be suppressed. In addition, FIG. 6 (B)
6C, the step 101e may be provided inside the end of the charging member 101, or even when the step 101e is at the end of the charging member 103 as shown in FIG. It may be sandwiched by being suppressed by another member 101f. When the amount of adhesive on the spacer member 103 is small, the charging member 10
The rotation of 1 may cause the spacer member 103 to move to the left or right or be peeled off. However, FIG. 6 (B) and FIG.
As shown in (C), by forming the step 101e, the spacer member 103 is prevented from displacing and the gap G of the charging member 101 is set to an appropriate value even if pressure is applied due to contact with the image carrier 61. The range can be maintained, the abnormal discharge can be suppressed, and the abnormal image can be prevented from being formed.
【００１２】また、帯電部材１０１の形状は、特に限定
されず、半円柱状で固定されて配設されていても良い。
また、図３に示すように、帯電部材１０１の形状が円柱
状で、両端をギア又は軸受１０４で回転可能に支持され
ていても良い。このように、帯電部材１０１は、像担持
体６１への最近接部から、像担持体６１移動方向の上下
流に漸次離間する局面で形成されていると、像担持体６
１をより均一に帯電させることができる。像担持体６１
に対向する帯電部材１０１が、先鋭な部分があると、そ
の部分の電位が高くなるために優先的に放電が開始さ
れ、像担持体６１の均一な帯電が困難になる。従って、
円柱状の形状で、曲面を有することで均一な像担持体６
１の帯電が可能になる。また、帯電部材１０１の放電し
ている表面は強いストレスを受ける。放電が常に同じ面
で発生するので、その劣化が促進され、さらに、削り落
ちることがある。そのために、帯電部材１０１の全面を
放電する面として使用できるのであれば、回転させるこ
とで、早期の劣化を防止することで、長期にわたって使
用することができる。また、スペーサ部材１０３を巻き
付ける段差１０１ｅは、旋盤等による切削加工で設ける
ことができる。また、外側の凸部を別部材にしても良
い。The shape of the charging member 101 is not particularly limited, and it may be fixed and arranged in a semi-cylindrical shape.
Further, as shown in FIG. 3, the charging member 101 may have a cylindrical shape, and both ends thereof may be rotatably supported by gears or bearings 104. As described above, when the charging member 101 is formed at a phase where the charging member 101 is gradually separated from the closest portion to the image carrier 61 in the upstream and downstream directions in the moving direction of the image carrier 61, the image carrier 6 is formed.
1 can be charged more uniformly. Image carrier 61
If the charging member 101 facing to the point has a sharp portion, the potential of that portion becomes high, so that the discharge is preferentially started and it becomes difficult to uniformly charge the image carrier 61. Therefore,
A uniform image carrier 6 having a cylindrical shape and having a curved surface
1 charge is possible. In addition, the discharging surface of the charging member 101 is strongly stressed. Since the discharge always occurs on the same surface, its deterioration is promoted and it may be scraped off. Therefore, if the entire surface of the charging member 101 can be used as a discharging surface, it can be used for a long period of time by rotating it to prevent early deterioration. The step 101e around which the spacer member 103 is wound can be provided by cutting with a lathe or the like. Also, the outer convex portion may be a separate member.
【００１３】図７は、本発明の帯電装置に備えられる帯
電部材の半径方向の断面図である。帯電部材１０１は、
中心に金属製芯金による軸部１０１ａ、その外側に中抵
抗層１０１ｃと最外層に表面層１０１ｄとを有する本体
部１０１ｂからなる構造をしている。軸部１０１ａは、
例えば、直径が８〜２０ｍｍのステンレス、アルミニウ
ムの高い剛性と導電性を有している金属製又は１×１０
３Ω・ｃｍ以下、好ましくは１×１０２Ω・ｃｍ以下で
高い剛性を有する導電性の樹脂等で構成される。中抵抗
層１０１ｃは、１×１０５Ω・ｃｍ〜１×１０９Ω・ｃ
ｍの体積抵抗率で、１〜２ｍｍ程度の厚さにすることが
好ましい。表面層１０１ｄは、１×１０６Ω・ｃｍ〜１
×１０１０Ω・ｃｍの体積抵抗率で、１０μｍ程度の厚
さが好ましい。表面層１０１ｄの体積抵抗率は、中抵抗
層１０１ｃの電気抵抗率より高くすることが好ましい。
ここで、本体部１０１ｂは、中抵抗層１０１ｃと表面層
１０１ｄとの２層構造で示したが、特にこの構造に限定
されるものではなく、単層でも３層であっても良い。FIG. 7 is a radial cross-sectional view of the charging member provided in the charging device of the present invention. The charging member 101 is
The shaft 101a is made of a metal core at the center, and the main body 101b has a medium resistance layer 101c on the outside and a surface layer 101d at the outermost layer. The shaft portion 101a is
For example, stainless steel having a diameter of 8 to 20 mm, metal made of aluminum having high rigidity and conductivity, or 1 × 10
It is made of a conductive resin or the like having a high rigidity of 3 Ω · cm or less, preferably 1 × 10 2 Ω · cm or less. The medium resistance layer 101c is 1 × 10 5 Ω · cm to 1 × 10 9 Ω · c.
The volume resistivity of m is preferably about 1 to 2 mm. The surface layer 101d is 1 × 10 6 Ω · cm to 1
A volume resistivity of × 10 10 Ω · cm and a thickness of about 10 μm are preferable. The volume resistivity of the surface layer 101d is preferably higher than the electrical resistivity of the medium resistance layer 101c.
Here, the main body portion 101b has a two-layer structure including the medium resistance layer 101c and the surface layer 101d, but the main body portion 101b is not particularly limited to this structure and may have a single layer or three layers.
【００１４】中抵抗層１０１ｃには、従来は、ヒドリン
ゴム等のゴムを用いていたが、ここでは、ゴムより膨張
係数の低い樹脂を用いて、導電剤を混入して電気抵抗を
調整する。通常、樹脂の線膨張係数はゴムの約１／２以
下であり、樹脂の体積膨張係数は等方性の場合ゴムの約
１／６以下になる。従来のように、ゴムを用いると、熱
や湿度により、ゴムの寸法精度が大きく変化し、間隙Ｇ
が小さくなり像担持体６１と接触することがある。ゴム
には、その弾性を発揮させるためや劣化防止のために数
種類の可塑剤、活性剤が添加されており、さらに、導電
剤を分散させるために分散補助剤を添加していることが
ある。像担持体６１の表面は、ポリカーボネイト、アク
リル等の非晶性樹脂が多く用いられており、可塑剤、活
性剤等により非常に弱い。また、帯電部材１０１と像担
持体６１とが接触していると、その接触部分にトナー等
の異物を巻き込み、帯電部材１０１が汚染されて帯電不
良となる。さらに、像担持体６１も汚染されて、横筋等
の異常画像が形成される。Conventionally, rubber such as hydrin rubber has been used for the medium resistance layer 101c, but here, a resin having a lower expansion coefficient than that of rubber is used to mix the conductive agent to adjust the electric resistance. Usually, the coefficient of linear expansion of resin is about 1/2 or less of that of rubber, and the volume expansion coefficient of resin is about 1/6 or less of that of rubber when it is isotropic. When rubber is used as in the past, the dimensional accuracy of the rubber changes greatly due to heat and humidity, and the gap G
May become small and may come into contact with the image carrier 61. To the rubber, several kinds of plasticizers and activators are added to exert its elasticity and to prevent deterioration, and a dispersion aid may be added to disperse the conductive agent. Amorphous resins such as polycarbonate and acrylic are often used on the surface of the image carrier 61 and are very weak due to plasticizers, activators and the like. Further, when the charging member 101 and the image carrier 61 are in contact with each other, foreign matter such as toner is caught in the contact portion, and the charging member 101 is contaminated, resulting in poor charging. Further, the image carrier 61 is also contaminated and an abnormal image such as a horizontal stripe is formed.
【００１５】ここで、中抵抗層１０１ｃの樹脂として
は、ポリエチレン、ポリプロピレン等のオレフィン樹
脂、ポリスチレン及びその共重合体等のスチレン系樹
脂、ポリメタクリル酸メチル等のアクリル系樹脂等を用
いることができる。樹脂には、導電剤のほかに強度を向
上、寸法の精度を向上させるためにカーボンファイバ
ー、グラスファイバー、炭化物、硼化物等のセラミック
スを混入することにより膨張係数を小さくすることがで
きる。導電剤としては、過酸化リチウム等のアルカリ金
属塩、過塩素酸ナトリウム等の過塩素酸塩、テトラブチ
ルアンモニウム塩等の４級アンモニウム塩、高分子導電
剤等のイオン系導電剤、カーボンブラック、銀粉、銅粉
等の金属粉、ＩＴＯ等のセラミックス粉を用いることが
できる。表面層１０１ｄは、表面張力が小さいフッ素系
樹脂に導電剤を混入して電気抵抗を調整する。フッ素系
樹脂としては、ポリテトラフルオロエチレンの共重合体
を用いることができる。導電剤としては、中抵抗層１０
１ｃと同様に、カーボンブラック、銀粉、銅粉等の金属
粉、ＩＴＯ等のセラミックス粉を用いることができる。Here, as the resin of the medium resistance layer 101c, an olefin resin such as polyethylene or polypropylene, a styrene resin such as polystyrene and a copolymer thereof, an acrylic resin such as polymethylmethacrylate, or the like can be used. . In addition to the conductive agent, the resin may be mixed with ceramics such as carbon fiber, glass fiber, carbide, and boride in order to improve strength and dimensional accuracy, so that the expansion coefficient can be reduced. As the conductive agent, an alkali metal salt such as lithium peroxide, a perchlorate salt such as sodium perchlorate, a quaternary ammonium salt such as tetrabutylammonium salt, an ionic conductive agent such as a polymer conductive agent, carbon black, Metal powder such as silver powder and copper powder, and ceramic powder such as ITO can be used. The surface layer 101d adjusts electric resistance by mixing a conductive agent in a fluorine-based resin having a small surface tension. As the fluororesin, a polytetrafluoroethylene copolymer can be used. As the conductive agent, the medium resistance layer 10
Similar to 1c, carbon black, metal powder such as silver powder and copper powder, and ceramic powder such as ITO can be used.
【００１６】帯電部材１０１と像担持体６１との間隙Ｇ
は、スペーサ部材１０３により１００μｍ以下、特に、
２０〜５０μｍの範囲にする。これにより、帯電装置１
００の作動時における異常画像の形成を抑えることがで
きる。間隙Ｇが、１００μｍ以上では、像担持体６１に
到達するまでの距離も長くなることで、パッシェンの法
則の放電開始電圧が大きくなり、さらに、像担持体６１
までの放電空間が大きくなることで、像担持体６１を所
定の帯電をさせるためには放電による放電生成物が多量
に必要となり、これが画像形成後も放電空間に多量に残
留し、像担持体６１に付着して、像担持体６１の経時劣
化を促進する原因になる。また、この間隙Ｇが小さい
と、像担持体６１までの到達距離も短く、放電エネルギ
ーも小さくても像担持体６１を帯電させることができ
る。しかし、帯電部材１０１と像担持体６１により形成
される空間が狭くなり、空気の流が悪くなってしまう。
そのために、放電空間で形成された放電生成物はこの空
間内に滞留するために、間隙Ｇが大きい場合と同様に、
画像形成後も放電空間に多量に残留し、像担持体６１に
付着して、像担持体６１の経時劣化を促進する原因にな
る。従って、放電エネルギーを小さくして放電生成物の
生成を少なくし、かつ、空気が滞留しない程度の空間を
形成することが好ましい。そのために、間隙Ｇは、１０
０μ以下であって、２０〜５０μｍの範囲にすることが
好ましい。これにより、ストリーマ放電の発生を防止
し、放電生成物の生成を少なくして像担持体６１に堆積
する量を少なくして、斑点状の画像斑・像流れを防止す
ることができる。A gap G between the charging member 101 and the image carrier 61
Is less than 100 μm due to the spacer member 103, in particular,
The range is 20 to 50 μm. As a result, the charging device 1
It is possible to suppress the formation of an abnormal image during the operation of 00. If the gap G is 100 μm or more, the distance to reach the image carrier 61 also becomes long, and the discharge start voltage according to Paschen's law becomes large.
Since the discharge space up to the point becomes large, a large amount of discharge products due to discharge are required to charge the image carrier 61 to a predetermined amount, and a large amount of this discharge product remains in the discharge space even after image formation. It becomes a cause of accelerating the deterioration of the image carrier 61 with time by adhering to the image carrier 61. Further, when the gap G is small, the reaching distance to the image carrier 61 is short and the image carrier 61 can be charged even if the discharge energy is small. However, the space formed by the charging member 101 and the image carrier 61 becomes narrow, and the air flow becomes poor.
Therefore, since the discharge products formed in the discharge space stay in this space, as in the case where the gap G is large,
Even after the image formation, a large amount remains in the discharge space and adheres to the image carrier 61, which causes the deterioration of the image carrier 61 over time. Therefore, it is preferable to reduce the discharge energy to reduce the generation of discharge products and to form a space in which air does not stay. Therefore, the gap G is 10
It is preferably 0 μ or less and preferably in the range of 20 to 50 μm. As a result, it is possible to prevent the generation of streamer discharge, reduce the generation of discharge products, and reduce the amount of the discharge products to be deposited on the image carrier 61, and to prevent spotted image spots / image deletions.
【００１７】ここで、上述したように、像担持体６１上
に現像後に残留するトナーは、像担持体６１に対向して
設けられるクリーニング装置６４によりクリーニングさ
れるが、完全に除去するのは困難であり、極わずかのト
ナーがクリーニング装置を通過し、帯電装置１００へと
搬送されてくる。このときに、トナーの粒径が間隙Ｇよ
り大きいと、トナーは回転する像担持体６１や帯電部材
１０１により摺擦されて熱を帯び、帯電部材１０１に融
着することがある。このトナーが融着した部分は、像担
持体６１に近くなるために優先的に放電が生ずる異常放
電を起こす。従って、間隙Ｇは、画像形成装置１に用い
られるトナーの最大粒径よりも大きいことが好ましい。As described above, the toner remaining on the image carrier 61 after development is cleaned by the cleaning device 64 provided so as to face the image carrier 61, but it is difficult to completely remove it. Therefore, a very small amount of toner passes through the cleaning device and is conveyed to the charging device 100. At this time, if the particle diameter of the toner is larger than the gap G, the toner may be rubbed by the rotating image carrier 61 or the charging member 101 to be heated and fused to the charging member 101. The portion where the toner is fused adheres to the image carrier 61, so that abnormal discharge occurs preferentially, causing abnormal discharge. Therefore, the gap G is preferably larger than the maximum particle size of the toner used in the image forming apparatus 1.
【００１８】また、帯電部材１０１は、図３に示すよう
に、帯電装置１００の図示しないハウジングの側板に設
けられる軸受１０４に嵌合され、軸受１０４には従動し
ない摩擦係数の低い樹脂による軸受１０４に設ける圧縮
バネ１０５により像担持体６１表面方向に押圧されてい
る。これにより、機械的振動、芯金の偏位があっても一
定の間隙Ｇを形成することができる。押圧する荷重は、
４〜２５Ｎにする。好ましくは、６〜１５Ｎにする。帯
電部材１０１は、軸受１０４で固定されていても、回転
するときの振動、帯電部材１０１の偏心、その表面の凹
凸により間隙Ｇの大きさが変動し、間隙Ｇが適正な範囲
からはずれる場合があり、このために、経時的には像担
持体６１の劣化を促進することになる。ここで、荷重と
は、スペーサ部材１０３を通して像担持体６１に加わる
すべての荷重を意味する。これは、帯電部材１０１の両
端に設けられる圧縮バネ１０５の力、帯電部材１０１と
クリーニング部材１０２の自重等により調整できる。荷
重が小さいと、帯電部材１０１の回転時による変動、駆
動するギア等の衝撃力による跳ね上がりを抑えることが
できない。荷重が大きいと、帯電部材１０１と嵌合する
軸受１０４との摩擦が大きくなり、経時的な摩耗量を大
きくして変動を促進することになる。従って、荷重を４
〜２５Ｎ、好ましくは、６〜１５Ｎの範囲にすることに
より、間隙Ｇを適正な範囲にして、放電生成物の生成を
少なくして像担持体６１に堆積する量を少なくして像担
持体６１の寿命を延ばし、かつ、斑点状の異常画像・画
像流を防止することができる。Further, as shown in FIG. 3, the charging member 101 is fitted into a bearing 104 provided on a side plate of a housing (not shown) of the charging device 100, and is not driven by the bearing 104. The bearing 104 is made of resin having a low friction coefficient. It is pressed in the surface direction of the image carrier 61 by the compression spring 105 provided at. Thereby, a constant gap G can be formed even if there is mechanical vibration or deviation of the cored bar. The load to press is
4 to 25N. It is preferably 6 to 15N. Even if the charging member 101 is fixed by the bearing 104, the size of the gap G may fluctuate due to vibration when rotating, eccentricity of the charging member 101, and unevenness of the surface, and the gap G may deviate from an appropriate range. Therefore, the deterioration of the image carrier 61 is accelerated over time. Here, the load means all the loads applied to the image carrier 61 through the spacer member 103. This can be adjusted by the force of the compression springs 105 provided at both ends of the charging member 101, the weight of the charging member 101 and the cleaning member 102, and the like. If the load is small, it is not possible to suppress fluctuations due to the rotation of the charging member 101 and bounce due to impact force of the driven gear or the like. When the load is large, the friction between the charging member 101 and the bearing 104 that is fitted therein becomes large, which increases the amount of wear over time and promotes fluctuation. Therefore, load 4
˜25N, preferably 6 to 15N, the gap G is set to an appropriate range, the amount of discharge products is reduced, and the amount deposited on the image carrier 61 is reduced to reduce the amount of the image carrier 61. It is possible to extend the life of the image and prevent spotted abnormal images and image flows.
【００１９】また、スペーサ部材１０３の像担持体６１
表面の移動方向における接触幅Ｗを０．５ｍｍ以下にす
る。接触幅Ｗは、図３に示すように、帯電部材１０１の
各層の材料・厚さと荷重の大きさにより制御することが
できる。接触幅Ｗを０．５ｍｍ以下にすることで、回転
する像担持体６１表面のうねり、偏心等により像担持体
６１側から帯電部材１０１に加えられる外力又は圧縮バ
ネ１０５による帯電部材１０１への押圧する荷重が変化
しても、間隙Ｇが大きく変動するのを阻止することがで
きる。また、スペーサ部材１０３は、円周方向に切れ目
があると、荷重より押圧されているために、この部分か
ら接着剤が染み出したり、切れ目から剥がれたりするこ
とが多い。このために、切れ目をなくすことで、像担持
体６１との接触による圧力を受けても、接着剤が染み出
したり、剥がれるのを防止する。また、接着剤を用いな
いスペーサ部材１０３を用いることが好ましい。これに
より、染み出した接着剤にトナー等が付着するのを防止
することができる。さらに、 スペーサ部材１０３は、
この帯電部材１０１の本体部１０１ｂの、中抵抗層１０
１ｃと表面層１０１ｄよりも硬度が低いことが好まし
い。スペーサ部材１０３には、像担持体６１と接触して
いるために圧力がかかっている。このために、スペーサ
部材１０３が帯電部材１０１の段差１０１ｅ中で回転す
ることがある。そのときに、スペーサ部材１０３の方を
帯電部材１０１よりも硬度が高いと帯電部材１０１を摩
耗する。そのために、スペーサ部材１０３の硬度を低く
して、スペーサ部材１０３を摩耗させて、間隙Ｇが変動
した場合にはスペーサ部材１０３のみを交換する。これ
により、帯電部材１０３の寿命を延ばすことができる。Further, the image carrier 61 of the spacer member 103.
The contact width W in the moving direction of the surface is 0.5 mm or less. The contact width W can be controlled by the material and thickness of each layer of the charging member 101 and the magnitude of the load, as shown in FIG. By setting the contact width W to 0.5 mm or less, the external force applied to the charging member 101 from the image carrier 61 side due to the undulation or eccentricity of the surface of the rotating image carrier 61 or the pressing force of the compression spring 105 on the charging member 101. Even if the load applied changes, the gap G can be prevented from largely changing. When the spacer member 103 has a cut in the circumferential direction, it is often pressed by the load, so that the adhesive often exudes from this portion or peels off from the cut. Therefore, by eliminating the breaks, the adhesive is prevented from exuding or peeling off even when pressure is applied due to contact with the image carrier 61. Further, it is preferable to use the spacer member 103 that does not use an adhesive. This makes it possible to prevent toner and the like from adhering to the exuding adhesive. Further, the spacer member 103 is
The medium resistance layer 10 of the main body 101b of the charging member 101.
1c and the surface layer 101d are preferably lower in hardness. Pressure is applied to the spacer member 103 because it is in contact with the image carrier 61. For this reason, the spacer member 103 may rotate in the step 101e of the charging member 101. At that time, if the spacer member 103 has a higher hardness than the charging member 101, the charging member 101 is worn. Therefore, the hardness of the spacer member 103 is lowered, the spacer member 103 is abraded, and when the gap G changes, only the spacer member 103 is replaced. As a result, the life of the charging member 103 can be extended.
【００２０】図８は、スペーサ部材の外観を示す斜視図
である。図８（Ａ）は、熱収縮性樹脂製のスペーサ部材
の外観で、図８（Ｂ）は、弾性を有する金属製のスペー
サ部材の外観である。また、スペーサ部材１０３には、
熱収縮性の樹脂を用いることができる。図８（Ａ）に示
すように、円周方向に切れ目のないチューブ状のスペー
サ部材１０３を帯電部材１０１の段差１０１ｅに配置
し、熱処理して収縮させて巻き付ける。ここで、スペー
サ部材１０３を収縮させるのに熱を用いたが、特に限定
されず、紫外線等の光によって収縮するものであっても
良い。スペーサ部材１０３は、ポリエチレン、ポリオレ
フィン等のオレフィン樹脂、ポエチレンテレフタレー
ト、ポリブチレンテレフタレート等のポリエステル樹
脂、ポリテトラフルオロエチレン等のフッ素系樹脂を用
いることができる。さらに、これらの収縮性の樹脂を用
いることが好ましい。収縮は、特別な処理をすることで
収縮するものであってもよく、例えば、熱又は光を作用
させることが挙げられる。また、このスペーサ部材１０
３は、接着剤を用いないことが好ましい。帯電部材１０
１端部の内側に段差１０１ｅを設け、両側を壁にしてス
ペーサ部材１０３を抑えることで、接着剤を用いなく
て、多少スペーサ部材１０３のみが回転したり又は滑っ
ても、間隙Ｇが変動することはない。また、これによ
り、接着剤が用いる必要が無く、接着剤の染み出しによ
る放電生成物の形成を防止することができる。FIG. 8 is a perspective view showing the outer appearance of the spacer member. FIG. 8A shows the appearance of the spacer member made of heat-shrinkable resin, and FIG. 8B shows the appearance of the spacer member made of metal having elasticity. In addition, the spacer member 103 includes
A heat-shrinkable resin can be used. As shown in FIG. 8A, a tubular spacer member 103 having no break in the circumferential direction is arranged on the step 101e of the charging member 101, and is heat-treated to shrink and wound. Here, heat is used to shrink the spacer member 103, but the spacer member 103 is not particularly limited, and may be one that shrinks by light such as ultraviolet rays. For the spacer member 103, an olefin resin such as polyethylene or polyolefin, a polyester resin such as polyethylene terephthalate or polybutylene terephthalate, or a fluorine resin such as polytetrafluoroethylene can be used. Furthermore, it is preferable to use these shrinkable resins. The contraction may be one that contracts by a special treatment, and examples thereof include applying heat or light. In addition, this spacer member 10
No. 3 preferably does not use an adhesive. Charging member 10
By providing the step 101e inside one end and holding the spacer member 103 with both sides as walls, the gap G varies even if only the spacer member 103 rotates or slides to some extent without using an adhesive. There is no such thing. In addition, this eliminates the need to use an adhesive and can prevent the formation of discharge products due to the seepage of the adhesive.
【００２１】また、スペーサ部材１０３には、弾性を有
する金属又はゴムを用いることができる。図８（Ｂ）に
示すように、円周方向に切れ目がある金属製のスペーサ
部材１０３を帯電部材１０１の段差１０１ｅに配置し、
金属の弾性による圧縮力を利用して巻き付ける。ここ
で、スペーサ部材１０３を収縮させるのに金属の弾性を
用いたが、特に限定されず、ゴムの弾性による圧縮力に
よって収縮するものであっても良い。スペーサ部材１０
３は、金属としては、アルミニウム、鉄、銅、チタン又
はこれらを主体とする合金を用いることができる。さら
に、これらの表面を酸化物で被覆して、電気的に絶縁性
にすることが好ましい。金属製のスペース部材１０３
は、像担持体６１の樹脂による感光層と比較して硬いた
め、さらに、表面に樹脂で被覆することが好ましい。こ
れにより、像担持体６１の感光層より硬度を低くして、
像担持体６１の摩耗を減らすことができる。また、ゴム
としては、天然ゴム、ポリウレタンゴム、クロロプレン
ゴム、ニトリル−ブタジエンゴム、シリコーンゴム、フ
ッ素ゴムを用いることができる。ＪＩＳ−Ａ：ゴム硬度
が７０Ｈｓ以上が好ましく、さらに、シリカ、アルミ
ナ、グラスファイバー等を添加して硬化させたものが好
ましい。これにより、間隙Ｇの変動を防ぐことができ
る。The spacer member 103 may be made of elastic metal or rubber. As shown in FIG. 8B, a metallic spacer member 103 having a cut in the circumferential direction is arranged on the step 101e of the charging member 101,
It is wound by using the compressive force due to the elasticity of metal. Here, the elasticity of the metal is used to contract the spacer member 103, but the spacer member 103 is not particularly limited, and may be contracted by the compressive force due to the elasticity of the rubber. Spacer member 10
As metal 3, aluminum, iron, copper, titanium, or an alloy mainly containing these can be used. Further, it is preferable to coat these surfaces with an oxide to make them electrically insulating. Space member 103 made of metal
Is harder than the photosensitive layer made of resin of the image carrier 61, and therefore it is preferable to further coat the surface with resin. Thereby, the hardness is lower than that of the photosensitive layer of the image carrier 61,
The wear of the image carrier 61 can be reduced. Further, as the rubber, natural rubber, polyurethane rubber, chloroprene rubber, nitrile-butadiene rubber, silicone rubber, or fluororubber can be used. JIS-A: A rubber hardness of 70 Hs or more is preferable, and a material obtained by adding silica, alumina, glass fiber or the like and curing the same is preferable. This can prevent the gap G from changing.
【００２２】図９は、本発明の帯電部材であって、段差
とスペーサ部材の一つの例である。図９（Ａ）は、段差
にスペーサ部材を配置し、図９（Ｂ）は、スペーサ部材
を段差に押し込んだ状況を示している。図９に示すよう
に、帯電部材１０１の端部内側に２つの小さい段差１０
１ｅを設け、ここに収縮性樹脂製のスペーサ部材１０３
を巻き付けるときに、圧力をかけて段差１０１ｅに樹脂
製スペーサ部材１０３を押し込むことで、樹脂製のスペ
ーサ部材１０３は帯電部材１０１の段差１０１ｅに固定
できる。これにより、軸方向における接触幅Ａで帯電部
材１０１と像担持体６１が接触して、間隙Ｇを一定に保
つことができる。また、帯電部材１０１の回転方向は、
端部にギアを配設して、像担持体６１と逆方向に回転さ
せる。帯電部材１０１の回転させる線速度は、像担持体
６１の線速度以上の線速度で回転させることが好まし
く、同じ線速度が特に好ましい。帯電部材１０１の線速
度を像担持体６１より遅くする場合は、印加する電圧に
よっては帯電が不安定になり、像担持体６１を均一に帯
電させることが困難になる。FIG. 9 shows an example of the step and the spacer member of the charging member of the present invention. FIG. 9 (A) shows a situation in which a spacer member is arranged at the step, and FIG. 9 (B) shows a situation in which the spacer member is pushed into the step. As shown in FIG. 9, two small steps 10 are formed inside the end of the charging member 101.
1e is provided, and a spacer member 103 made of shrinkable resin is provided here.
The resin spacer member 103 can be fixed to the step 101e of the charging member 101 by pressing the resin spacer member 103 into the step 101e while winding. As a result, the charging member 101 and the image carrier 61 contact each other with the contact width A in the axial direction, and the gap G can be kept constant. Further, the rotation direction of the charging member 101 is
Gears are arranged at the ends to rotate the image carrier 61 in the opposite direction. The linear velocity of rotation of the charging member 101 is preferably equal to or higher than that of the image carrier 61, and the same linear velocity is particularly preferable. When the linear velocity of the charging member 101 is set lower than that of the image carrier 61, the charging becomes unstable depending on the applied voltage, and it becomes difficult to uniformly charge the image carrier 61.
【００２３】また、帯電装置１００は、帯電部材１０１
の汚染を除去するためのクリーニング部材１０２を備え
る。図１０は、本発明の帯電装置に備えられるクリーニ
ング部材の構成を示す概略図である。クリーニング部材
１０２は、図１０に示すように、帯電装置１００の図示
しないハウジングの側板に設けられる軸受に嵌合され、
回転可能に軸支される。このクリーニング部材１０２
は、帯電部材１０１に当接して、外周面をクリーニング
する。帯電部材１０１の表面にトナー、紙粉、部材の破
損物等の異物が付着すると、電界が異物部分に集中する
ために優先的に放電が生ずる異常放電を起こす。逆に、
電気的絶縁性の異物が広い範囲に付着すると、その部分
では放電が生じないために、像担持体６１に帯電斑が生
ずる。このために、帯電装置１００には帯電部材１０１
の表面をクリーニングするクリーニング部材１０２を設
けることが好ましい。The charging device 100 includes a charging member 101.
The cleaning member 102 is provided for removing the contamination. FIG. 10 is a schematic view showing the structure of the cleaning member provided in the charging device of the present invention. As shown in FIG. 10, the cleaning member 102 is fitted to a bearing provided on a side plate of a housing (not shown) of the charging device 100,
It is rotatably supported. This cleaning member 102
Contacts the charging member 101 to clean the outer peripheral surface. When foreign matter such as toner, paper powder, or broken material of the member adheres to the surface of the charging member 101, an electric field concentrates on the foreign matter portion, and abnormal discharge occurs preferentially. vice versa,
When the electrically insulating foreign matter adheres to a wide area, no electric discharge is generated in that area, so that charging unevenness occurs on the image carrier 61. To this end, the charging device 100 includes a charging member 101.
It is preferable to provide a cleaning member 102 for cleaning the surface of the.
【００２４】また、帯電装置１００は、帯電部材１０１
に電圧を印加する電源を備える。電圧としては、直流電
圧だけでも良いが、直流電圧と交流電圧を重畳した電圧
が好ましい。帯電部材１０１の層構成が不均一な部分が
ある場合には、直流電圧のみを印加すると像担持体６１
の表面電位が不均一になることがある。重畳した電圧で
は、帯電部材１０１表面が等電位となり、放電が安定し
て像担持体６１を均一に帯電させることができる。重畳
する電圧における交流電圧は、ピ−ク間電圧を像担持体
６１の帯電開始電圧の２倍以上にすることが好ましい。
帯電開始電圧とは、帯電部材１０１に直流のみを印加し
た場合に像担持体６１が帯電され始めるときの電圧の絶
対値である。これにより、像担持体６１から帯電部材１
０１への逆放電が生じ、そのならし効果で像担持体６１
をより安定した状態で均一に帯電させることができる。The charging device 100 includes a charging member 101.
A power source for applying a voltage to is provided. The voltage may be a DC voltage alone, but a voltage obtained by superimposing a DC voltage and an AC voltage is preferable. If there is a portion where the layer structure of the charging member 101 is non-uniform, it is necessary to apply only a DC voltage to the image carrier 61.
The surface potential of may become uneven. With the superposed voltage, the surface of the charging member 101 becomes equipotential, and the discharge is stabilized and the image carrier 61 can be uniformly charged. As for the AC voltage in the superimposed voltage, it is preferable that the peak-to-peak voltage is twice or more the charging start voltage of the image carrier 61.
The charging start voltage is an absolute value of the voltage when the image carrier 61 starts to be charged when only direct current is applied to the charging member 101. As a result, the image carrier 61 to the charging member 1
The reverse discharge to 01 occurs, and the leveling effect produces the image carrier 61.
Can be uniformly charged in a more stable state.
【００２５】スペーサ部材１０３の接触幅Ｗを０．５ｍ
ｍ以下にすることで、間隙Ｇの変動を抑えることができ
る。これは、帯電部材１０１の本体部１０１ｂに硬質の
樹脂に、強度を向上させるためのセラミックス等によっ
て更に硬質にする。これにより、この硬質樹脂の帯電部
材１０１は、像担持体６１の回転中に、帯電部材１０１
と像担持体６１の偏心、回転の振動又は圧縮バネのばら
つきによる押圧力の差異によっても接触幅Ｗがほとんど
同じにすることができる。さらに、帯電部材１０１と像
担持体６１の間の間隙Ｇは、所定の大きさに制御するこ
とができる。また、像担持体６１の駆動装置のギア、チ
ェーンなどの駆動部材が経時的に摩耗等により偏心が大
きくなったり、衝撃力が加わっても間隙Ｇの変動を抑え
ることができる。これにより、帯電部材１０１の全面を
一様に帯電に用いられることから、一部を過度に使用さ
れる場合に生ずる劣化が生ずることなく、帯電部材１０
１の寿命も延ばすことができる。The contact width W of the spacer member 103 is 0.5 m
By setting it to be equal to or less than m, the variation of the gap G can be suppressed. This is made by using a hard resin for the main body portion 101b of the charging member 101 and further hardening it with ceramics or the like for improving the strength. As a result, the charging member 101 made of the hard resin is charged during the rotation of the image carrier 61.
The contact width W can be almost the same due to the difference in the pressing force due to the eccentricity of the image carrier 61, the vibration of rotation, or the variation of the compression spring. Further, the gap G between the charging member 101 and the image carrier 61 can be controlled to a predetermined size. Further, it is possible to suppress the fluctuation of the gap G even if the gears of the driving device of the image carrier 61, the driving members such as the chains, become eccentric due to abrasion or the like, or the impact force is applied. As a result, since the entire surface of the charging member 101 is uniformly used for charging, the charging member 10 is not deteriorated when a part thereof is excessively used.
The life of 1 can be extended.
【００２６】図１１は、本発明の作像ユニットの構成を
示す概略図である。画像形成装置１本体に着脱可能であ
って、少なくとも像担持体６１と上述の帯電装置１００
を配設する作像ユニットを用いることができる。この作
像ユニットでは、像担持体６１と帯電装置１００とは、
上述したように、一定の間隙Ｇを持って対向するように
組み込まれている。このために、画像形成装置１から着
脱しても間隙Ｇを一定に保持することができる。従っ
て、画像形成時には、像担持体６１を均一に帯電するこ
とができ、放電生成物が少なく、かつ、異常画像のない
画像を形成することができる。また、経時的な変化によ
り帯電部材１０１と像担持体６１の当接が生じないため
に、帯電部材１０１の経時的な劣化が少なく、作像ユニ
ット全体の寿命を延ばすことができる。また、この作像
ユニットは、帯電装置１００を配置し、像担持体６１を
配置しないものであっても良い。像担持体６１、現像装
置６３、帯電装置１００はそれぞれ寿命が異なり、メン
テナンス性を考慮して最適の組み合わせをとることがで
きる。このほかに、作像ユニットは、少なくとも像担持
体６１のクリーニング装置６４、現像装置６３、のいず
れかを配設するものであっても良い。また、作像ユニッ
トは、像担持体６１、帯電装置１００を作像ユニット内
に組み付けるときの、位置出しのための当接部材を有す
る。像担持体６１、帯電装置１００は、それぞれ別に組
み付けられるために、当接部材を作像ユニット本体に設
け、像担持体６１と帯電部材１０１とを所定の間隙Ｇに
する。また、像担持体６１、帯電装置１００は、寿命が
異なることがあり、回収して補修し再度又は新たな像担
持体６１等を組み付ける場合であっても、当接部材を設
けることで、所定の間隙Ｇにすることができる。FIG. 11 is a schematic diagram showing the structure of the image forming unit of the present invention. It is detachable from the main body of the image forming apparatus 1, and at least the image carrier 61 and the charging device 100 described above.
It is possible to use an image forming unit in which In this image forming unit, the image carrier 61 and the charging device 100 are
As described above, they are installed so as to face each other with a constant gap G therebetween. Therefore, the gap G can be maintained constant even when the image forming apparatus 1 is attached to or detached from the image forming apparatus 1. Therefore, at the time of image formation, the image carrier 61 can be uniformly charged, the amount of discharge products is small, and an image without an abnormal image can be formed. Further, since the charging member 101 and the image carrier 61 do not come into contact with each other due to changes over time, deterioration of the charging member 101 over time is small, and the life of the entire image forming unit can be extended. Further, this image forming unit may be one in which the charging device 100 is arranged and the image carrier 61 is not arranged. The image carrier 61, the developing device 63, and the charging device 100 have different lifespans, and an optimum combination can be taken in consideration of maintainability. In addition, the image forming unit may be provided with at least one of the cleaning device 64 for the image carrier 61 and the developing device 63. Further, the image forming unit has a contact member for positioning when the image carrier 61 and the charging device 100 are assembled in the image forming unit. Since the image carrier 61 and the charging device 100 are separately assembled, a contact member is provided in the main body of the image forming unit so that the image carrier 61 and the charging member 101 have a predetermined gap G. In addition, the image carrier 61 and the charging device 100 may have different lifespans, and even when the image carrier 61 and the charging device 100 are recovered and repaired or a new image carrier 61 or the like is assembled, the contact member is provided to provide a predetermined value. The gap G can be set to G.
【００２７】また、少なくとも像担持体６１と上述の帯
電装置１００を有する画像形成装置１である。画像形成
装置１では、像担持体６１と帯電装置１００とは、上述
したように、一定の間隙Ｇを持って対向するように組み
込まれている。これにより、像担持体６１と帯電装置１
００との間の間隙Ｇを、像担持体６１等との駆動・回転
時で偏心により中心がぶれたり、回転による振動、衝撃
力が生じて、帯電部材１０１の像担持体６１への圧力が
変化しても、一定に維持することができる。さらに、像
担持体６１が備える光導電体をアモルファスシリコン系
にすることが好ましい。アモルファスシリコン系像担持
体６１は、真空中の気相成長法で製造されるために表面
が極めて平滑になる。従って、像担持体６１を回転させ
ても帯電部材１０１との間で形成される間隙Ｇの変動が
少なく、帯電部材１０１表面の全体で放電し、像担持体
６１は均一に帯電される。さらに、間隙Ｇが一定に維持
されることから放電生成物の発生を少なく抑えることが
できる。また、光導電性の有機物質を用いる像担持体６
１は、樹脂中に有機物質を分散させている。層構成によ
り有機物質が表面層に含まれないことが多いが、いずれ
の層構成であっても、樹脂を主体としている。そのため
に、上述の帯電部材１０１を用いることで間隙Ｇを一定
に維持できるが、さらに、像担持体６１の表面層にフィ
ラーを分散させて硬質の表面にすることが好ましい。耐
摩耗性が向上し、経時的劣化を抑え、寿命を延ばすこと
ができる。フィラーとしては、グラスファイバー、アル
ミナ、シリカ等の酸化物を用いることができる。The image forming apparatus 1 has at least the image carrier 61 and the charging device 100 described above. In the image forming apparatus 1, the image carrier 61 and the charging device 100 are incorporated so as to face each other with a constant gap G as described above. As a result, the image carrier 61 and the charging device 1
The gap G between the charging member 101 and the image carrier 61 is deviated at the time of driving / rotation with the image carrier 61 or the like, and vibration and impact force are generated by the rotation, so that the pressure of the charging member 101 on the image carrier 61 is increased. Even if it changes, it can be kept constant. Further, the photoconductor provided in the image carrier 61 is preferably made of amorphous silicon. The surface of the amorphous silicon-based image carrier 61 is extremely smooth because it is manufactured by a vapor phase growth method in vacuum. Therefore, even if the image carrier 61 is rotated, the gap G formed between the image carrier 61 and the charging member 101 does not fluctuate, the entire surface of the charging member 101 is discharged, and the image carrier 61 is uniformly charged. Furthermore, since the gap G is maintained constant, the generation of discharge products can be suppressed to a small level. Further, an image carrier 6 using a photoconductive organic substance
In No. 1, an organic substance is dispersed in the resin. Organic materials are often not contained in the surface layer due to the layer structure, but in any layer structure, the resin is the main component. Therefore, the gap G can be maintained constant by using the above-mentioned charging member 101, but it is preferable to further disperse the filler in the surface layer of the image carrier 61 to form a hard surface. Wear resistance is improved, deterioration over time is suppressed, and life can be extended. As the filler, oxides such as glass fiber, alumina and silica can be used.
【００２８】この画像形成装置１は、上述の帯電装置１
００のほかに下記の装置を搭載する。図１に示すよう
に、画像形成装置１における露光装置７０は、帯電装置
１００により帯電された像担持体６１に光を照射して、
光導電性を有する像担持体６１上に静電潜像を形成す
る。光Ｌは、蛍光灯、ハロゲンランプ等のランプ、ＬＥ
Ｄ、ＬＤ等の半導体素子によるレーザ光線等であっても
良い。ここでは、図示しない画像処理部からの信号によ
り像担持体６１の回転速度に同期して照射される場合
は、ＬＤの素子を用いる。The image forming apparatus 1 is the same as the charging device 1 described above.
In addition to 00, the following devices are installed. As shown in FIG. 1, the exposure device 70 in the image forming apparatus 1 irradiates the image carrier 61 charged by the charging device 100 with light,
An electrostatic latent image is formed on the image carrier 61 having photoconductivity. The light L is a lamp such as a fluorescent lamp or a halogen lamp, LE
It may be a laser beam by a semiconductor element such as D or LD. Here, when irradiation is performed in synchronization with the rotation speed of the image carrier 61 by a signal from an image processing unit (not shown), an LD element is used.
【００２９】現像装置６３は、現像剤担持体を有し、現
像装置６３内に貯蔵されたトナーを供給ローラで攪拌部
に搬送されて、キャリアを含む現像剤と混合・攪拌さ
れ、像担持体６１に対向する現像領域に搬送される。こ
のときに、正又は負極性に帯電されたトナーは、像担持
体６１の静電潜像に転移して現像される。現像剤は、磁
性又は非磁性の一成分現像剤又はこれらを併せて使用す
るものであっても良いし、湿式の現像液を用いるもので
あっても良い。The developing device 63 has a developer carrying member, and the toner stored in the developing device 63 is conveyed to an agitating section by a supply roller and mixed and agitated with a developer containing a carrier to obtain an image carrying member. It is conveyed to the developing area facing 61. At this time, the positively or negatively charged toner is transferred to the electrostatic latent image on the image carrier 61 and developed. The developer may be a magnetic or non-magnetic one-component developer or a combination thereof, or may be a wet developer.
【００３０】１次転写装置６２は、像担持体６１上の現
像されたトナー像を中間転写体５０の裏側からトナーの
極性と反対の極性の電場を形成して、中間転写体５０に
転写する。１次転写装置６２は、コロトロン、スコロト
ロンのコロナ転写器、転写ローラ、転写ブラシのいずれ
の転写装置であっても良い。その後、給紙装置２２から
搬送されてくる記録媒体と同期させて、再度２次転写装
置５１による転写で記録媒体上にトナー像を転写する。
ここで、最初の転写が中間転写体５０ではなく、記録媒
体に直接転写する方式であっても良い。The primary transfer device 62 transfers the developed toner image on the image carrier 61 from the back side of the intermediate transfer body 50 to the intermediate transfer body 50 by forming an electric field having a polarity opposite to that of the toner. . The primary transfer device 62 may be any one of a corotron, a scorotron corona transfer device, a transfer roller, and a transfer brush. After that, the toner image is transferred onto the recording medium by transfer by the secondary transfer device 51 again in synchronization with the recording medium conveyed from the paper feeding device 22.
Here, the first transfer may be a method of directly transferring to the recording medium instead of the intermediate transfer body 50.
【００３１】定着装置８０は、記録媒体上のトナー像
を、加熱及び／又は加圧して記録媒体上にトナー像を固
定して定着させる。ここでは、１対の加圧・定着ローラ
の間を通過させ、このときに熱・圧力をかけて、トナー
の結着樹脂を溶融しながら定着させる。定着装置８０
は、ローラ状ではなく、ベルト状であっても良いし、ハ
ロゲンランプ等で熱照射により定着させるものであって
も良い。像担持体６１のクリーニング装置６４は、転写
されずに像担持体６１上に残留したトナーをクリーニン
グして除去し、次の画像形成を可能にする。クリーニン
グ装置６４は、ウレタン等のゴムによるブレード、ポリ
エステル等の繊維によるファーブラシ等のいずれの方式
であっても良い。The fixing device 80 heats and / or pressurizes the toner image on the recording medium to fix and fix the toner image on the recording medium. Here, the toner is passed between a pair of pressure / fixing rollers, and heat / pressure is applied at this time to fix the binder resin of the toner while melting. Fixing device 80
May be belt-shaped instead of roller-shaped, or may be fixed by heat irradiation with a halogen lamp or the like. The cleaning device 64 for the image carrier 61 cleans and removes the toner remaining on the image carrier 61 without being transferred, and enables the next image formation. The cleaning device 64 may be of any type such as a blade made of rubber such as urethane and a fur brush made of fiber such as polyester.
【００３２】以下、本発明の画像形成装置１の動作につ
いて説明する。読み取り部３０は、原稿搬送部３６の原
稿台上に原稿をセットするか、又、原稿搬送部３６を開
いてコンタクトガラス３１上に原稿をセットし、原稿搬
送部３６を閉じて原稿を押さえる。そして、不図示のス
タートスイッチを押すと、原稿搬送部３６に原稿をセッ
トしたときは原稿をコンタクトガラス３１上へと搬送し
て後、他方コンタクトガラス３１上に原稿をセットした
ときは直ちに、第１読み取り走行体及び第２読み取り走
行体３２、３３を走行する。そして、第１読み取り走行
体３２で光源から光を発射するとともに原稿面からの反
射光をさらに反射して第２読み取り走行体３３に向け、
第２読み取り走行体３３のミラーで反射して結像レンズ
３４を通して読取りセンサであるＣＣＤ３５に入れ、画
像情報を読み取る。読み取った画像情報をこの制御部に
送る。制御部は、読み取り部３０から受け取った画像情
報に基づき、画像形成部６０の露光装置７０内に配設さ
れた図示しないＬＤ又はＬＥＤ等を制御して像担持体６
１に向けて、書き込みのレーザ光Ｌを照射させる。この
照射により、像担持体６１の表面には静電潜像が形成さ
れる。The operation of the image forming apparatus 1 of the present invention will be described below. The reading unit 30 sets an original on the original table of the original conveying unit 36, or opens the original conveying unit 36 to set the original on the contact glass 31, and closes the original conveying unit 36 to hold the original. When a start switch (not shown) is pressed, the original is conveyed onto the contact glass 31 when the original is set on the original conveying section 36, and immediately after the original is set on the other contact glass 31. The first reading traveling body and the second reading traveling body 32, 33 travel. Then, the first reading carriage 32 emits light from the light source, and the light reflected from the document surface is further reflected and directed to the second reading carriage 33.
The image information is read by being reflected by the mirror of the second reading traveling body 33 and passing through the imaging lens 34 into the CCD 35 which is a reading sensor. The read image information is sent to this control unit. Based on the image information received from the reading unit 30, the control unit controls an LD, an LED, or the like (not shown) provided in the exposure device 70 of the image forming unit 60 to control the image carrier 6.
The laser light L for writing is emitted toward 1. By this irradiation, an electrostatic latent image is formed on the surface of the image carrier 61.
【００３３】給紙部２０は、多段に備える給紙カセット
２１から給紙ローラにより記録媒体を繰り出し、繰り出
した記録媒体を分離ローラで分離して給紙路に送り出
し、画像形成部６０の給紙路に記録媒体を搬送ローラで
搬送する。この給紙部２０以外に、手差し給紙も可能と
なっており、手差しのための手差しトレイ、手差しトレ
イ上の記録媒体を手差し給紙路に向けて一枚ずつ分離す
る分離ローラも装置側面に備えている。レジストローラ
２３は、それぞれ給紙カセット２１に載置されている記
録媒体を１枚だけ排出させ、中間転写体５０と２次転写
装置５１との間に位置する２次転写部に送る。画像形成
部６０では、読み取り部３０から画像情報を受け取る
と、上述のようなレーザ書き込みや、現像プロセスを実
施させて像担持体６１上に潜像を形成させる。The paper feeding unit 20 feeds a recording medium from a multi-staged paper feeding cassette 21 by a paper feeding roller, separates the fed recording medium by a separating roller, and feeds it to a paper feeding path to feed the image forming unit 60. The recording medium is conveyed to the path by a conveying roller. In addition to the paper feeding section 20, manual feeding is also possible, and a manual feeding tray for manual feeding and a separating roller for separating the recording media on the manual feeding tray one by one toward the manual feeding path are provided on the side of the apparatus. I have it. The registration roller 23 discharges only one recording medium placed in each of the paper feeding cassettes 21 and sends it to the secondary transfer portion located between the intermediate transfer body 50 and the secondary transfer device 51. Upon receiving the image information from the reading unit 30, the image forming unit 60 forms the latent image on the image carrier 61 by performing the above laser writing or developing process.
【００３４】現像装置６３内の現像剤は、図示しない磁
極により汲み上げて保持され、現像剤担持体上に磁気ブ
ラシを形成する。さらに、現像剤担持体に印加する現像
バイアス電圧により像担持体６１に転移して、その像担
持体６１上の静電潜像を可視化して、トナー像を形成す
る。現像バイアス電圧は、交流電圧と直流電圧を重畳さ
せている。次に、トナー像に応じたサイズの記録媒体を
給紙させるべく、給紙部２０の給紙ローラのうちの１つ
を作動させる。また、これに伴なって、駆動モータで支
持ローラの１つを回転駆動して他の２つの支持ローラを
従動回転し、中間転写体５０を回転搬送する。同時に、
個々の画像形成ユニットでその像担持体６１を回転して
像担持体６１上にそれぞれ、ブラック・イエロー・マゼ
ンタ・シアンの単色画像を形成する。そして、中間転写
体５０の搬送とともに、それらの単色画像を順次転写し
て中間転写体５０上に合成トナー像を形成する。The developer in the developing device 63 is drawn and held by a magnetic pole (not shown) to form a magnetic brush on the developer carrier. Further, a developing bias voltage applied to the developer carrying member transfers to the image carrying member 61 to visualize the electrostatic latent image on the image carrying member 61 to form a toner image. As the developing bias voltage, an AC voltage and a DC voltage are superposed. Next, one of the paper feed rollers of the paper feed unit 20 is operated to feed a recording medium of a size corresponding to the toner image. Along with this, one of the support rollers is rotationally driven by the drive motor and the other two support rollers are driven to rotate, and the intermediate transfer member 50 is rotatably conveyed. at the same time,
The image carrier 61 is rotated by each image forming unit to form black, yellow, magenta, and cyan single color images on the image carrier 61, respectively. Then, as the intermediate transfer member 50 is conveyed, the single color images are sequentially transferred to form a synthetic toner image on the intermediate transfer member 50.
【００３５】一方、給紙部２０の給紙ローラの１つを選
択回転し、給紙カセット２１の１つから記録媒体を繰り
出し、分離ローラで１枚ずつ分離して給紙路に入れ、搬
送ローラで画像形成装置１の画像形成部６０内の給紙路
に導き、この記録媒体をレジストローラ２３に突き当て
て止める。そして、中間転写体５０上の合成トナー像に
タイミングを合わせてレジストローラ２３を回転し、中
間転写体５０と２次転写装置５１との当接部である２次
転写部に記録媒体を送り込み、この２次転写部に形成さ
れている２次転写バイアスや当接圧力などの影響によっ
てトナー像を２次転写して記録媒体上にトナー像を記録
する。ここで、２次転写バイアスは、直流であることが
好ましい。画像転写後の記録媒体は、２次転写装置の搬
送ベルトで定着装置８０へと送り込み、定着装置８０で
加圧ローラによる加圧力と熱の付与によりトナー像を定
着させた後、排出ローラ４１で排紙トレイ４０上に排出
する。On the other hand, one of the paper feed rollers of the paper feed unit 20 is selectively rotated, the recording medium is fed out from one of the paper feed cassettes 21, separated by the separation rollers one by one, and put into a paper feed path for conveyance. The roller guides the recording medium to the paper feed path in the image forming unit 60 of the image forming apparatus 1 and abuts the recording medium against the registration roller 23 to stop the recording medium. Then, the registration roller 23 is rotated in synchronization with the synthetic toner image on the intermediate transfer body 50, and the recording medium is sent to the secondary transfer section, which is the contact section between the intermediate transfer body 50 and the secondary transfer device 51. The toner image is secondarily transferred by the influence of the secondary transfer bias formed in the secondary transfer portion and the contact pressure, and the toner image is recorded on the recording medium. Here, the secondary transfer bias is preferably direct current. The recording medium after the image transfer is sent to the fixing device 80 by the conveyance belt of the secondary transfer device, the fixing device 80 fixes the toner image by applying pressure and heat by the pressure roller, and then the discharging roller 41. The sheet is discharged onto the sheet discharge tray 40.
【００３６】[0036]
【実施例】（実施例１と比較例１）帯電部材の材質によ
る円周方向の接触幅Ｗに対する影響を評価した。実施例
１では、帯電部材の中抵抗層に硬質の樹脂を用い、比較
例１では、帯電部材の中抵抗層に軟質のゴムを用いる。
スペーサ部材は、同一の樹脂によるテープを用いる。ス
ペーサ部材を巻き付けた帯電部材を、天秤ばかりの積載
台面に接触させる。この帯電部材の上に透明なガラス板
を載せ、このガラス板に圧力をかける。このときに、ガ
ラス板と帯電部材の接触部分の接触幅Ｗを測定し、かつ
天秤ばかりの加圧力を測定した。その結果を表１に示
す。Example (Example 1 and Comparative Example 1) The influence of the material of the charging member on the contact width W in the circumferential direction was evaluated. In Example 1, a hard resin is used for the medium resistance layer of the charging member, and in Comparative Example 1, soft rubber is used for the medium resistance layer of the charging member.
A tape made of the same resin is used as the spacer member. The charging member around which the spacer member is wound is brought into contact with the loading table surface of the balance. A transparent glass plate is placed on the charging member, and pressure is applied to the glass plate. At this time, the contact width W of the contact portion between the glass plate and the charging member was measured, and the pressing force of the balance was measured. The results are shown in Table 1.
【表１】
表１からも明らかなように、硬質の樹脂を中抵抗層に用
いた実施例１の帯電部材は、帯電部材にかける圧力を変
えても、接触幅Ｗが変化しなかったが、軟質のゴムを用
いた比較例１の帯電部材は、圧力により接触幅Ｗが大き
く変化した。[Table 1] As is clear from Table 1, in the charging member of Example 1 using the hard resin for the medium resistance layer, the contact width W did not change even when the pressure applied to the charging member was changed, but the soft rubber was used. The contact width W of the charging member of Comparative Example 1 using No. 1 changed significantly due to the pressure.
【００３７】（実施例２）また、このときの画像形成装
置１の像担持体６１、帯電装置１００のプロセス条件
を、下記の条件にして、６万プリント、１５万プリント
のプリント試験を行なって、接着剤の染み出し、異常画
像の発生を評価した。像担持体
像担持体は、４層構造でＡｌ基体の上に下引層、キャリ
ア発生層、キャリア移動層、表面層からなっている。キ
ャリア発生材料は、フタロシアニン顔料を用いた。表面
層となる保護層には、ポリカーボネート樹脂を用い、フ
ィラーとして平均粒径０．０５〜０．８μｍのシリカを
用いた。像担持体の帯電条件等は、画像部電位：−１５
０Ｖ、非画像部電位：−７００Ｖ、像担持体の線速：２
４５ｍｍ／ｓ とした。帯電装置
帯電部材１０１は、円筒状で直径は１２ｍｍのものを用
い、段差を端部内側に接触幅Ａ：８ｍｍに設け、軸部は
直径：１０ｍｍ、材質：快削鋼（ＪＩＳ ＳＵＭ２
２）、中抵抗層は厚さ：２ｍｍ、材質：ＡＢＳ樹脂、導
電剤：エーテルアミド、表面層は厚さ：１０μｍ、材
質：フッ素樹脂、導電剤：ＩＴＯで、電圧条件は交流電
圧：２ｋＨｚ、Ｖｐ−ｐ：２ｋＶ、直流電圧：−４５０
Ｖで、スペーサ部材は熱収縮性フッ素樹脂、加圧した圧
力：１０Ｎ、クリーニング部材：ポリエステル繊維で、
接触幅Ｗは０．３ｍｍ、間隙Ｇは４０μｍにした。(Embodiment 2) Also, the image forming apparatus at this time is
Process conditions of the image carrier 61 of the apparatus 1 and the charging device 100
Under the following conditions, 60,000 prints, 150,000 prints
Perform a print test of the
Image generation was evaluated.Image carrier
The image carrier has a four-layer structure, an undercoat layer and a carrier on an Al substrate.
A generation layer, carrier transfer layer, and surface layer. Ki
A phthalocyanine pigment was used as the carrier generating material. surface
Polycarbonate resin is used for the protective layer,
As a filler, silica with an average particle size of 0.05 to 0.8 μm is used.
Using. The charging condition of the image carrier is, for example, the image portion potential: −15.
0 V, non-image area potential: -700 V, image carrier linear velocity: 2
It was set to 45 mm / s.Charging device
The charging member 101 has a cylindrical shape and a diameter of 12 mm.
A step is provided inside the end with a contact width A of 8 mm, and the shaft is
Diameter: 10 mm, Material: Free cutting steel (JIS SUM2
2), the middle resistance layer has a thickness of 2 mm, material: ABS resin, conductive
Electrical agent: ether amide, surface layer thickness: 10 μm, material
Quality: Fluororesin, Conductive agent: ITO, voltage condition is AC
Pressure: 2 kHz, Vp-p: 2 kV, DC voltage: -450
At V, the spacer member is heat-shrinkable fluororesin,
Power: 10N, cleaning material: polyester fiber,
The contact width W was 0.3 mm and the gap G was 40 μm.
【００３８】（比較例２）帯電部材１０１の表面層に、
発泡性ウレタンゴムにカーボンブラックを混入し、厚
さ：５ｍｍ、接触幅Ａ：５ｍｍにしたスペーサ部材１０
３を接着剤で帯電部材１０１に貼着した以外は、すべて
実施例２と同じ条件にした。(Comparative Example 2) On the surface layer of the charging member 101,
Spacer member 10 in which carbon black is mixed in foamable urethane rubber to have a thickness of 5 mm and a contact width A of 5 mm
All conditions were the same as in Example 2 except that No. 3 was attached to the charging member 101 with an adhesive.
【００３９】その結果、表２に示す。The results are shown in Table 2.
【表２】
６万プリントした後では、実施例２の帯電ローラは、何
ら問題が生じていない。比較例１の帯電部材１０１は、
接着剤が染み出していたが、画像流れ、画像斑等の異常
画像は現れていない。１５万プリントした後では、実施
例２では、スペーサ部材１０３はよれたり、移動したり
することはなかった。また、画像流れ、画像斑等の異常
画像は現れていない。比較例２では、接着剤が染み出し
ていたし、放電生成物が原因の画像流れが画像上に現れ
ていた。また、接着剤にトナー等が付着した異常生成物
が原因の画像斑が現れていた。[Table 2] After printing 60,000, the charging roller of Example 2 did not have any problem. The charging member 101 of Comparative Example 1 is
The adhesive had exuded, but abnormal images such as image deletion and image spots did not appear. After printing 150,000, in Example 2, the spacer member 103 did not twist or move. Further, no abnormal image such as image deletion or image spots appears. In Comparative Example 2, the adhesive had exuded, and the image deletion due to the discharge product appeared on the image. In addition, image unevenness due to an abnormal product in which toner or the like adheres to the adhesive appears.
【００４０】[0040]
【発明の効果】以上説明したように、本発明の帯電装置
は、帯電装置と像担持体の間に形成される間隙を、画像
形成動作時であっても、一定に維持することができ、帯
電部材の全面で一様な放電をさせることで、異常放電と
放電生成物の発生を少なく抑え、異常画像が形成される
のを防止して、高品位の画像を得ることができる。ま
た、本発明の作像ユニットでは、像担持体と帯電部材の
経時的な接触を抑えることで、経時的な劣化を抑え、異
常画像の形成を防止し、作像ユニットの寿命を延ばすこ
とができる。また、本発明の画像形成装置では、帯電部
材の経時的な劣化を抑え、異常画像が形成されるのを防
止することができる。As described above, in the charging device of the present invention, the gap formed between the charging device and the image carrier can be maintained constant even during the image forming operation. By causing uniform discharge over the entire surface of the charging member, abnormal discharge and generation of discharge products can be suppressed, abnormal images can be prevented from being formed, and high-quality images can be obtained. Further, in the image forming unit of the present invention, by suppressing the contact between the image carrier and the charging member with time, deterioration with time can be suppressed, formation of an abnormal image can be prevented, and the life of the image forming unit can be extended. it can. Further, in the image forming apparatus of the present invention, deterioration of the charging member over time can be suppressed and an abnormal image can be prevented from being formed.
【図１】本発明の帯電部材、本発明の帯電装置を用いる
画像形成装置である本発明の画像形成装置の構成を示す
概略図である。FIG. 1 is a schematic diagram showing a configuration of an image forming apparatus of the present invention which is an image forming apparatus using the charging member of the present invention and the charging device of the present invention.
【図２】本発明を説明するための画像形成部の拡大図で
ある。FIG. 2 is an enlarged view of an image forming unit for explaining the present invention.
【図３】本発明の帯電装置に備えられる帯電部材の構成
を示す概略図である。FIG. 3 is a schematic diagram showing a configuration of a charging member included in the charging device of the present invention.
【図４】本発明の帯電部材と像担持体との位置関係を示
す概略図である。FIG. 4 is a schematic view showing a positional relationship between a charging member and an image carrier of the present invention.
【図５】本発明の帯電装置に備えられる帯電部材の構造
を示す概略図である。FIG. 5 is a schematic view showing a structure of a charging member provided in the charging device of the present invention.
【図６】本発明の帯電装置に備えられる帯電部材にスペ
ーサ部材を配設した状態を示す概略構成図である。FIG. 6 is a schematic configuration diagram showing a state in which a spacer member is provided on a charging member included in the charging device of the present invention.
【図７】本発明の帯電装置に備えられる帯電部材の半径
方向の断面図である。FIG. 7 is a radial cross-sectional view of a charging member included in the charging device of the present invention.
【図８】スペーサ部材の外観を示す斜視図である。FIG. 8 is a perspective view showing an outer appearance of a spacer member.
【図９】図９は、本発明の帯電部材であって、段差とス
ペーサ部材の一つの例である。FIG. 9 is an example of a step and a spacer member of the charging member of the present invention.
【図１０】本発明の帯電装置に備えられるクリーニング
部材の構成を示す概略図である。FIG. 10 is a schematic diagram showing a configuration of a cleaning member provided in the charging device of the present invention.
【図１１】本発明の作像ユニットの構成を示す概略図で
ある。FIG. 11 is a schematic diagram showing a configuration of an image forming unit of the present invention.
１ 画像形成装置 １０ 画像形成部 ２０ 給紙部 ２１ 給紙カセット ２２ 給紙装置 ２３ レジストローラ ３０ 読み取り部 ３１ コンタクトガラス ３２、３３ 読み取り走行体 ３４ レンズ ３５ ＣＣＤ ３６ 自動原稿搬送装置 ４０ 排紙収納部 ４１ 排紙ローラ ５０ 中間転写体 ５１ ２次転写装置 ５２ 中間転写ベルトクリーニング装置 ６０ 画像形成部 ６１ 像担持体 ６２ １次転写装置 ６３ 現像装置 ６３ａ 現像剤担持体 ６４ クリーニング装置 ６４ａ クリーニングブラシ ６４ｂ クリーニングブレード ７０ 露光装置 ８０ 定着装置 １００ 帯電装置 １０１ 帯電部材 １０１ａ 軸部 １０１ｂ 本体部 １０１ｃ 中抵抗層 １０１ｄ 表面層 １０１ｅ 段差 １０１ｆ 別の部材 １０２ クリーニング部材 １０３ スペーサ部材 １０４ 軸受 １０５ 加圧スプリング Ｇ 間隙 Ｌ レーザ光 Ｗ 接触幅（円周方向） Ａ 接触幅（軸方向） 1 Image forming device 10 Image forming section 20 paper feeder 21 Paper feed cassette 22 Paper feeder 23 Registration roller 30 Reader 31 contact glass 32, 33 Read running body 34 lens 35 CCD 36 Automatic Document Feeder 40 Paper output storage section 41 Paper ejection roller 50 Intermediate transfer body 51 Secondary transfer device 52 Intermediate transfer belt cleaning device 60 Image forming unit 61 Image carrier 62 Primary transfer device 63 developing device 63a developer carrier 64 cleaning device 64a cleaning brush 64b cleaning blade 70 Exposure equipment 80 Fixing device 100 charging device 101 charging member 101a shaft 101b main body 101c Middle resistance layer 101d surface layer 101e step 101f Another member 102 cleaning member 103 Spacer member 104 bearing 105 Pressure spring G gap L laser light W contact width (circumferential direction) A contact width (axial direction)
───────────────────────────────────────────────────── フロントページの続き (72)発明者 小野 博司 東京都大田区中馬込１丁目３番６号 株式 会社リコー内 (72)発明者 小菅 明朗 東京都大田区中馬込１丁目３番６号 株式 会社リコー内 (72)発明者 小池 寿男 東京都大田区中馬込１丁目３番６号 株式 会社リコー内 (72)発明者 杉浦 健治 東京都大田区中馬込１丁目３番６号 株式 会社リコー内 (72)発明者 中里 保史 東京都大田区中馬込１丁目３番６号 株式 会社リコー内 (72)発明者 成田 豊 東京都大田区中馬込１丁目３番６号 株式 会社リコー内 (72)発明者 田中 亜希子 東京都大田区中馬込１丁目３番６号 株式 会社リコー内 Ｆターム(参考） 2H068 AA04 AA21 CA06 DA23 FC01 2H200 FA07 FA08 GA12 GA16 GA18 GA23 GA47 GA49 HA13 HA28 HB12 HB22 HB45 HB46 HB47 HB48 LA07 LA14 LA17 LA18 LA38 LA40 LC08 MA01 MA03 MA04 MA12 MA14 MB01 MB04 MC01 MC02 MC18 NA02 ─────────────────────────────────────────────────── ─── Continued front page (72) Inventor Hiroshi Ono 1-3-3 Nakamagome, Ota-ku, Tokyo Stocks Company Ricoh (72) Inventor Akira Kosuge 1-3-3 Nakamagome, Ota-ku, Tokyo Stocks Company Ricoh (72) Inventor Toshio Koike 1-3-3 Nakamagome, Ota-ku, Tokyo Stocks Company Ricoh (72) Inventor Kenji Sugiura 1-3-3 Nakamagome, Ota-ku, Tokyo Stocks Company Ricoh (72) Inventor Yasushi Nakazato 1-3-3 Nakamagome, Ota-ku, Tokyo Stocks Company Ricoh (72) Inventor Yutaka Narita 1-3-3 Nakamagome, Ota-ku, Tokyo Stocks Company Ricoh (72) Inventor Akiko Tanaka 1-3-3 Nakamagome, Ota-ku, Tokyo Stocks Company Ricoh F term (reference) 2H068 AA04 AA21 CA06 DA23 FC01 2H200 FA07 FA08 GA12 GA16 GA18 GA23 GA47 GA49 HA13 HA28 HB12 HB22 HB45 HB46 HB47 HB48 LA07 LA14 LA17 LA18 LA38 LA40 LC08 MA01 MA03 MA04 MA12 MA14 MB01 MB04 MC01 MC02 MC18 NA02
Claims (24)
て、像担持体に対向して配置されて、像担持体表面を帯
電させる帯電部材において、 前記帯電部材は、軸部と軸部を被覆する本体部とから構
成され、 像担持体の画像形成領域外に対応する本体部に収縮性を
有するスペーサ部材を設けて、像担持体と帯電部材との
間で間隙を形成することを特徴とする帯電部材。1. A charging member disposed in a charging device, the charging member being arranged to face an image carrier and charging the surface of the image carrier, wherein the charging member comprises a shaft portion and a shaft portion. And a spacer member having a contracting property is provided in the main body portion corresponding to the outside of the image forming area of the image carrier to form a gap between the image carrier and the charging member. Characteristic charging member.
域外に対応する本体部の端部に又は端部より内側に段差
を有することを特徴とする請求項１に記載の帯電部材。2. The charging member according to claim 1, wherein the charging member has a step at an end portion of the main body portion corresponding to the outside of the image forming area of the image carrier or inside the end portion.
に配設されることを特徴とする請求項１又は２に記載の
帯電部材。3. The charging member according to claim 1, wherein the charging member has a cylindrical shape and is rotatably arranged.
成されることを特徴とする請求項１ないし３のいずれか
に記載の帯電部材。4. The charging member according to claim 1, wherein the main body is made of a resin containing a conductive agent.
ことを特徴とする請求項１ないし４のいずれかに記載の
帯電部材。5. The charging member according to claim 1, wherein the spacer member has no break.
縮することを特徴とする請求項１ないし５のいずれかに
記載の帯電部材。6. The charging member according to claim 1, wherein the spacer member contracts by heat or light.
ることを特徴とする請求項１ないし５のいずれかに記載
の帯電部材。7. The charging member according to claim 1, wherein the spacer member contracts due to elasticity.
製であることを特徴とする請求項７に記載の帯電部材。8. The charging member according to claim 7, wherein the spacer member is made of elastic rubber.
製であることを特徴とする請求項８に記載の帯電部材。9. The charging member according to claim 8, wherein the spacer member is made of metal having elasticity.
請求項１ないし９のいずれかに記載の帯電部材。10. The charging member according to claim 1, wherein the spacer member is fixed to the main body portion without an adhesive.
度が低いことを特徴とする請求項１ないし８、１０のい
ずれかに記載の帯電部材。11. The charging member according to claim 1, wherein the spacer member has a hardness lower than that of the charging member.
電させる帯電部材を配設する帯電装置において、 前記帯電部材は、軸部と軸部を被覆する本体部とから構
成され、かつ像担持体の画像形成領域外に対応する本体
部に収縮性を有するスペーサ部材を設けて、像担持体と
帯電部材との間で間隙を形成することを特徴とする帯電
装置。12. A charging device provided with a charging member facing the image carrier and charging the surface of the image carrier, wherein the charging member comprises a shaft portion and a main body portion covering the shaft portion, and A charging device characterized in that a spacer member having contractibility is provided in a main body portion corresponding to the outside of the image forming area of the image carrier to form a gap between the image carrier and the charging member.
領域外に対応する本体部の端部に又は端部より内側に段
差を有することを特徴とする請求項１２に記載の帯電装
置。13. The charging device according to claim 12, wherein the charging member has a step at an end portion of the main body portion corresponding to the outside of the image forming area of the image carrier or inside the end portion.
成される間隙は、接触しない距離であって、８０μｍ以
下であることを特徴とする請求項１２又は１３に記載の
帯電装置。14. The charging device according to claim 12, wherein a gap formed between the charging member and the image carrier is a distance in which the charging member and the image carrier do not come into contact with each other and is 80 μm or less.
持体に接触し、 前記スペーサ部材は、４〜２５Ｎの荷重で像担持体に対
して押圧され、 かつ、スペーサ部材の像担持体表面の移動する円周方向
における接触幅を０．５ｍｍ以下にすることを特徴とす
る請求項１２ないし１４のいずれかに記載の帯電装置。15. The charging member contacts the image carrier with a spacer member, the spacer member is pressed against the image carrier with a load of 4 to 25 N, and the surface of the image carrier of the spacer member is pressed. 15. The charging device according to claim 12, wherein a contact width in the moving circumferential direction is 0.5 mm or less.
いずれかに記載の帯電部材であることを特徴とする請求
項１２ないし１５のいずれかに記載の帯電装置。16. The charging device according to claim 12, wherein the charging member is the charging member according to any one of claims 4 to 11.
ニットであって、画像形成装置本体に着脱可能な作像ユ
ニットであって、前記作像ユニットの帯電装置は、像担
持体に対向して配置されて、像担持体表面を帯電させる
帯電部材を配設する作像ユニットにおいて、 前記帯電部材は、軸部と軸部を被覆する本体部とから構
成され、かつ像担持体の画像形成領域外に対応する本体
部にスペーサ部材を設けて像担持体と間隙を形成するこ
とを特徴とする作像ユニット。17. An image forming unit including at least a charging device, the image forming unit being attachable to and detachable from a main body of the image forming apparatus, wherein the charging device of the image forming unit faces the image carrier. An image forming unit having a charging member arranged to charge the surface of the image carrier, wherein the charging member includes a shaft portion and a main body portion covering the shaft portion, and an image forming area of the image carrier. An image forming unit, characterized in that a spacer member is provided on a body portion corresponding to the outside to form a gap with an image carrier.
項１ないし１１のいずれかに記載の帯電部材であること
を特徴とする作像ユニット。18. The image forming unit according to claim 1, wherein the charging member of the image forming unit is the charging member according to any one of claims 1 to 11.
又は像担持体を配設することを特徴とする請求項１７又
は１８に記載の作像ユニット。19. The image forming unit includes a developing device and / or a developing device.
The image forming unit according to claim 17 or 18, further comprising an image carrier.
持体の一部に当接して位置決めする当接部材を備えるこ
とを特徴とする請求項１７ないし１９のいずれかに記載
の作像ユニット。20. The image forming unit according to claim 17, wherein the image forming unit includes an abutting member that abuts and positions a part of the charging device and the image carrier. .
装置を配設する画像形成装置であって、 前記画像形成装置の帯電装置は、像担持体に対向して配
置されて、像担持体表面を帯電させる帯電部材を配設す
る画像形成装置において、 前記帯電部材は、軸部と軸部を被覆する本体部とから構
成され、かつ 像担持体の画像形成領域外に対応する本体部にスペーサ
部材を設けて像担持体と間隙を形成することを特徴とす
る画像形成装置。21. An image forming apparatus comprising at least an image carrier, a charging device, and a developing device, wherein the charging device of the image forming device is arranged to face the image carrier, and the surface of the image carrier is formed. In the image forming apparatus having a charging member for charging, the charging member is composed of a shaft portion and a main body portion covering the shaft portion, and a spacer is provided on the main body portion outside the image forming area of the image carrier. An image forming apparatus comprising a member to form a gap with an image carrier.
項１ないし１１のいずれかに記載の帯電部材であること
を特徴とする画像形成装置。22. The image forming apparatus according to claim 1, wherein the charging member of the image forming apparatus is the charging member according to any one of claims 1 to 11.
て用いることを特徴とする請求項２１又は２２に記載の
画像形成装置。23. The image forming apparatus according to claim 21, wherein in the image forming apparatus, the image carrier uses amorphous silicon as a photoconductor.
させる表面層を有することを特徴とする請求項２１又は
２２に記載の画像形成装置。24. The image forming apparatus according to claim 21, wherein the image carrier includes an organic photoconductor and has a surface layer in which a filler is dispersed.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2002117895A JP3749501B2 (en) | 2002-04-19 | 2002-04-19 | Charging member, charging device, image forming unit and image forming apparatus using them |
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2002117895A JP3749501B2 (en) | 2002-04-19 | 2002-04-19 | Charging member, charging device, image forming unit and image forming apparatus using them |
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| Publication Number | Publication Date |
|---|---|
| JP2003316119A true JP2003316119A (en) | 2003-11-06 |
| JP3749501B2 JP3749501B2 (en) | 2006-03-01 |
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ID=29534955
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|---|---|---|---|
| JP2002117895A Expired - Fee Related JP3749501B2 (en) | 2002-04-19 | 2002-04-19 | Charging member, charging device, image forming unit and image forming apparatus using them |
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Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2005301201A (en) * | 2004-03-16 | 2005-10-27 | Ricoh Co Ltd | Image forming apparatus with refacing mode |
| JP2006284827A (en) * | 2005-03-31 | 2006-10-19 | Ricoh Co Ltd | Image forming apparatus and toner |
| US7155146B2 (en) | 2003-11-20 | 2006-12-26 | Ricoh Company, Ltd. | Method and apparatus for electro photographic image forming capable of effectively performing an evenly charging operation |
| JP2011242647A (en) * | 2010-05-19 | 2011-12-01 | Ricoh Co Ltd | Electrifying member, process cartridge, and image forming apparatus |
-
2002
- 2002-04-19 JP JP2002117895A patent/JP3749501B2/en not_active Expired - Fee Related
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US7155146B2 (en) | 2003-11-20 | 2006-12-26 | Ricoh Company, Ltd. | Method and apparatus for electro photographic image forming capable of effectively performing an evenly charging operation |
| US7603063B2 (en) | 2003-11-20 | 2009-10-13 | Ricoh Company, Ltd. | Method and apparatus for electro photographic image forming capable of effectively performing an evenly charging operation |
| JP2005301201A (en) * | 2004-03-16 | 2005-10-27 | Ricoh Co Ltd | Image forming apparatus with refacing mode |
| JP4647259B2 (en) * | 2004-03-16 | 2011-03-09 | 株式会社リコー | How to remove protective substances |
| JP2006284827A (en) * | 2005-03-31 | 2006-10-19 | Ricoh Co Ltd | Image forming apparatus and toner |
| JP2011242647A (en) * | 2010-05-19 | 2011-12-01 | Ricoh Co Ltd | Electrifying member, process cartridge, and image forming apparatus |
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| Publication number | Publication date |
|---|---|
| JP3749501B2 (en) | 2006-03-01 |
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