JP3517439B2 - Charging member, charging device, image forming apparatus, and process cartridge - Google Patents
Charging member, charging device, image forming apparatus, and process cartridgeInfo
- Publication number
- JP3517439B2 JP3517439B2 JP29142193A JP29142193A JP3517439B2 JP 3517439 B2 JP3517439 B2 JP 3517439B2 JP 29142193 A JP29142193 A JP 29142193A JP 29142193 A JP29142193 A JP 29142193A JP 3517439 B2 JP3517439 B2 JP 3517439B2
- Authority
- JP
- Japan
- Prior art keywords
- charging
- tube
- layer
- foam layer
- 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.)
- Expired - Fee Related
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Landscapes
- Electrophotography Configuration And Component (AREA)
- Electrostatic Charge, Transfer And Separation In Electrography (AREA)
- Rolls And Other Rotary Bodies (AREA)
Description
【０００１】[0001]
【産業上の利用分野】本発明は、帯電部材、帯電装置、
画像形成装置、及びプロセスカートリッジに関する。よ
り詳しくは、
ａ．帯電部材を被帯電体に当接させて帯電を行う接触帯
電装置の接触帯電部材、
ｂ．帯電部材を被帯電体に当接させて帯電を行う接触帯
電装置、
ｃ．像担持体の帯電手段として、帯電部材を像担持体に
当接させて帯電を行う接触帯電装置を用いた画像形成装
置、
ｄ．少なくとも、像担持体と、該像担持体の帯電手段を
包含し、画像形成装置に対して着脱されるプロセスカー
トリッジ、
に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a charging member, a charging device,
The present invention relates to an image forming apparatus and a process cartridge. More specifically, a. A contact charging member of a contact charging device that charges the member by bringing the charging member into contact with a member to be charged; b. A contact charging device for charging a charging member by bringing it into contact with a member to be charged, c. An image forming apparatus using a contact charging device that charges a charging member by bringing the charging member into contact with the image carrier, as a charging unit of the image carrier, d. The present invention relates to an image carrier and at least a process cartridge that includes a charging unit for the image carrier and is attached to and detached from an image forming apparatus.
【０００２】[0002]
【従来の技術】従来、例えば、電子写真プロセス・静電
記録プロセスなど、感光体・誘電体等の像担持体に該像
担持体を帯電処理する工程を含む画像形成プロセスを適
用して画像形成を実行する、複写機・レーザービームプ
リンター・静電記録装置等の画像形成装置においては、
被帯電体としての像担持体を帯電処理（除電処理も含
む）する手段機器としてコロナ放電により像担持体をコ
ロナ帯電させる、非接触式であるコロトロンやスコロト
ロン等のコロナ放電装置が広く利用されていた。2. Description of the Related Art Conventionally, image formation is performed by applying an image forming process including a step of charging an image carrier such as a photoconductor or a dielectric to an image carrier such as an electrophotographic process or an electrostatic recording process. In image forming apparatuses such as copiers, laser beam printers, electrostatic recording devices, etc.
Corona discharge devices such as a non-contact type corotron and scorotron, which corona-charge the image bearing member by corona discharge, are widely used as a device for charging the image bearing member as a member to be charged (including static elimination treatment). It was
【０００３】近時は接触式の帯電装置の利用が進められ
ている。接触帯電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に電荷を直接的に転移させ被帯電
体面を所用の電位に帯電するもので、コロナ放電装置に
比べて、被帯電体面に所望の電位を得るのに必要とされ
る印加電圧の低電圧化がはかれること、帯電過程で発生
するオゾン量がごく微量でありオゾン除去フィルターの
必要性がなくなること、そのため装置の排気系の構成が
簡略化されること、メンテナンスフリーであること、構
成が簡単であること、等の長所を有している。Recently, the use of a contact type charging device has been promoted. In the contact charging, a charging member to which a voltage is applied is brought into contact with a member to be charged to directly transfer the charge to the member to be charged, and the surface of the member to be charged is charged to a desired potential. The applied voltage required to obtain the desired potential on the surface of the charged body can be lowered, and the amount of ozone generated during the charging process is very small, eliminating the need for an ozone removal filter. It has advantages such as a simplified system configuration, maintenance-free operation, and simple configuration.
【０００４】そこで、例えば電子写真装置・静電記録装
置等の画像形成装置において、感光体、誘電体等の像担
持体、その他の被帯電体を帯電処理する手段としてコロ
ナ放電装置に変わるものとして注目され実用化もされて
いる。Therefore, for example, in an image forming apparatus such as an electrophotographic apparatus or an electrostatic recording apparatus, a corona discharge device is used as a means for charging a photoconductor, an image carrier such as a dielectric, and other charged members. It has been noticed and put into practical use.
【０００５】図６に接触帯電装置を像担持体の一次帯電
装置として用いた画像形成装置の一例の概略構成を示し
た。FIG. 6 shows a schematic structure of an example of an image forming apparatus using the contact charging device as a primary charging device of an image carrier.
【０００６】１は像担持体としての例えば電子写真感光
ドラムであり、矢印Ａ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。Reference numeral 1 denotes an electrophotographic photosensitive drum as an image bearing member, which is rotationally driven in the clockwise direction of arrow A at a predetermined peripheral speed (process speed).
【０００７】２０は接触帯電部材としての導電性ローラ
（帯電ローラ）である。２ａはローラ芯金棒、２ｂはこ
の芯金棒の外周に同心一体にローラ状に設けた導電性弾
性層である。この帯電ローラ２０は芯金棒２ａの両端部
にそれぞれ作用させた押し圧バネ３の押し圧力で感光ド
ラム１面に対して所定の押し圧力をもって圧接してお
り、感光ドラム１の回転に伴い従動回転する。Reference numeral 20 is a conductive roller (charging roller) as a contact charging member. Reference numeral 2a is a roller cored bar, and 2b is a conductive elastic layer which is concentrically and integrally provided on the outer periphery of the cored bar in a roller shape. The charging roller 20 is pressed against the surface of the photosensitive drum 1 with a predetermined pressing force by the pressing force of the pressing springs 3 acting on both ends of the cored bar 2a, and is driven to rotate as the photosensitive drum 1 rotates. To do.
【０００８】４は帯電ローラ２０に対する電圧印加電源
であり、この電源４により帯電ローラ２０の芯金棒２ａ
に接触させた接点板ばね４ａを介して感光ドラム１の帯
電開始電圧の２倍以上のピーク間電圧Ｖｐｐを有する振
動電圧（時間と共に電圧値が周期的に変化する電圧）Ｖ
ａｃと所定の直流電圧Ｖｄｃとを重畳した電圧（Ｖａｃ
＋Ｖｄｃ）が帯電ローラ２０に印加されて、回転駆動さ
れている感光ドラム１の外周面が均一に所定の極性・電
位に帯電される。Reference numeral 4 denotes a power supply for applying a voltage to the charging roller 20, and the power supply 4 serves as a core rod 2a of the charging roller 20.
An oscillating voltage (a voltage whose voltage value periodically changes) V having a peak-to-peak voltage Vpp that is at least twice as high as the charging start voltage of the photosensitive drum 1 via a contact leaf spring 4a brought into contact with
ac voltage and a predetermined DC voltage Vdc are superimposed (Vac
+ Vdc) is applied to the charging roller 20 to uniformly charge the outer peripheral surface of the photosensitive drum 1 which is rotationally driven to a predetermined polarity and potential.
【０００９】その感光ドラム１の帯電処理面に対して不
図示の露光装置（原稿画像投影露光装置・レーザースキ
ャナ等）により目的の画像情報の露光５（画像情報の書
き込み）がなされて、感光ドラム１面に目的の画像情報
に対応した静電潜像が形成され、該潜像が現像装置６に
よりトナー画像として現像される。Exposure 5 (writing of image information) of desired image information is performed on the charged surface of the photosensitive drum 1 by an unillustrated exposing device (original image projection exposing device, laser scanner, etc.), and the photosensitive drum is exposed. An electrostatic latent image corresponding to target image information is formed on one surface, and the latent image is developed as a toner image by the developing device 6.
【００１０】そのトナー画像が感光ドラム１と該感光ド
ラム１に当接させた転写ローラ８との圧接ニップ部であ
る転写部位Ｎにおいて、該転写部位Ｎに不図示の給紙部
から所定のタイミングで給送された転写材７に対して順
次に転写されていく。At the transfer portion N where the toner image is a pressure contact nip portion between the photosensitive drum 1 and the transfer roller 8 brought into contact with the photosensitive drum 1, the transfer portion N is fed to the transfer portion N at a predetermined timing from a sheet feeding portion (not shown). The images are sequentially transferred to the transfer material 7 fed in.
【００１１】転写部位Ｎにてトナー画像の転写を受けた
転写材７は感光ドラム１面から分離されて不図示の定着
装置へ搬送されてトナー画像の定着処理を受け画像形成
物（コピー・プリント）として出力される。The transfer material 7 to which the toner image has been transferred at the transfer portion N is separated from the surface of the photosensitive drum 1 and conveyed to a fixing device (not shown) to undergo a toner image fixing process to form an image-formed product (copy / print). ) Is output.
【００１２】また転写材７へのトナー画像転写後の感光
ドラム１面はクリーニング装置９により転写残りトナー
等の残留付着物の除去を受けて清浄面化され、繰り返し
て作像に供される。The surface of the photosensitive drum 1 after the transfer of the toner image onto the transfer material 7 is cleaned by a cleaning device 9 to remove residual adhered substances such as transfer residual toner, and is repeatedly used for image formation.
【００１３】接触帯電部材としての帯電ローラ２０に対
する電圧印加は、直流電圧のみを印加する方式（ＤＣ印
加方式）と、上記例のように振動電圧を印加する（ＡＣ
印加方式、特開昭６３−１４９６６９号公報等）があ
る。後者のＡＣ印加方式の方が均一帯電処理性がよい。As for the voltage application to the charging roller 20 as the contact charging member, a method of applying only a DC voltage (DC applying method) and an oscillating voltage as in the above example (AC) are applied.
Application method, Japanese Patent Laid-Open No. 63-149669). The latter AC application method has better chargeability for uniform charging.
【００１４】しかしＡＣ印加方式においては問題点とし
て、振動電圧に起因する「帯電音」と呼ばれる振動騒音
の発生がある。この帯電音を軽減させる対策として、こ
れまで硬めのソリッドであった帯電部材の弾性層２ｂを
非常に柔軟な発泡部材等の層とすることで、帯電部材２
０と感光ドラム１との振動を抑えることができ、帯電音
も気にならないレベルまで軽減することが可能である。However, a problem with the AC applying method is that vibration noise called "charging noise" is generated due to the vibration voltage. As a measure for reducing the charging noise, the charging member 2 is made by forming the elastic layer 2b of the charging member, which has been a hard solid so far, into a layer such as a very flexible foaming member.
The vibration between 0 and the photosensitive drum 1 can be suppressed, and the charging noise can be reduced to a level that is not noticeable.
【００１５】しかしながら、発泡部材は非常に柔軟なた
め発泡部材の材質、又は環境によって帯電部材が外部か
ら受ける力により永久変形をし、画像上に帯電不良等が
現れる可能性がある。これを防止する対策として、発泡
部材の外周面に抵抗層であり発泡部材に対し硬度が高い
チューブで覆う方法が考えられている。これにより発泡
部材に受ける力は小さくなり、帯電音も大きくなること
はない。更に発泡部材は表面性に難があったため、表面
性がよいチューブで覆うことで画像ムラ等の問題もなく
なる。However, since the foam member is very flexible, there is a possibility that the charging member may be permanently deformed by a force applied from the outside depending on the material of the foam member or the environment, and charging defects may appear on the image. As a measure to prevent this, a method of covering the outer peripheral surface of the foamed member with a tube having a high hardness and covering the foamed member is considered. As a result, the force applied to the foamed member is reduced, and the charging noise is not increased. Further, since the foamed member has a poor surface property, the problem of image unevenness can be eliminated by covering it with a tube having a good surface property.
【００１６】図７にそのような発泡部材層・チューブ層
を有する帯電ローラ２０の層構成例を示す横断面模型図
を示した。帯電ローラ２０は芯金棒２ａと、その外周に
形成したカーボン等の導電性粉体を分散させたポリウレ
タン等の発泡部材２ｂとチューブ２ｃ、更にその外周に
形成した導電層２ｄ、中抵抗層２ｅ、保護層２ｆからな
る。２ｂ1 は発泡部材２ｂの気泡部である。FIG. 7 shows a schematic cross-sectional view showing an example of the layer structure of the charging roller 20 having such a foam member layer / tube layer. The charging roller 20 includes a cored bar 2a, a foaming member 2b made of polyurethane or the like in which conductive powder such as carbon is dispersed, a tube 2c, a conductive layer 2d and a medium resistance layer 2e formed on the outer periphery of the cored bar 2a, It consists of a protective layer 2f. 2b 1 is a bubble portion of the foam member 2b.
【００１７】このような帯電ローラ２０は、図８のよう
に、先に原料を発泡させた発泡部材２ｂを作成し、それ
に芯金２ａとチューブ２ｃを挿入させて作製する方法
や、図９のように、チューブ２ｃの内側に芯金２ａを立
て、発泡部材の原料２ｂ2 を芯金２ａに差し込み固定さ
せた状態で該原料２ｂ2 を発泡ａさせることで芯金棒２
ａとチューブ２ｃとの間に発泡部材２ｂを形成させて作
製する方法などがある。表面性、精度、コストの面を考
慮すると、後者の方法が優れている。As shown in FIG. 8, such a charging roller 20 is manufactured by first forming a foaming member 2b in which a raw material is foamed, and inserting a core metal 2a and a tube 2c into the foaming member 2b. as such, make the core metal 2a to the inside of the tube 2c, a core raw material 2b 2 of the foamed member the raw material 2b 2 while being inserted and fixed to the core metal 2a by bubbling a Kanabo 2
There is a method in which the foam member 2b is formed between a and the tube 2c, and the like. The latter method is superior in consideration of surface properties, accuracy, and cost.
【００１８】[0018]
【発明が解決しようとする課題】しかし上述図９の後者
の方法においては次のような問題が起きた。即ち発泡部
材の原料２ｂ2 を発泡ａさせて芯金棒２ａとチューブ２
ｃの間に発泡部材２ｂを形成させた場合、チューブ２ｃ
と発泡した発泡部材２ｂとの界面において空気の逃げ道
がないため、空気がそのまま溜まり大きな気泡として残
ってしまう。この状態は一見表面性が良いように見える
が、この帯電部材２０が感光ドラム１と当接し、感光ド
ラム１が回転した場合、クリーニング装置９をすり抜け
てきた廃トナーが帯電部材２０と感光ドラム１間に入り
込み、帯電部材２０のチューブ２ｃの内側の界面が気泡
である部分にこの廃トナーが溜まり易くなり、画像上に
帯電不良となって黒い斑点のようなものが現れてしま
う。However, in the latter method of FIG. 9 described above, the following problems occur. That is, the raw material 2b 2 of the foaming member is foamed a and the cored bar 2a and the tube 2 are
When the foam member 2b is formed between the two tubes, the tube 2c
Since there is no escape path for air at the interface with the foamed foam member 2b, air accumulates as it is and remains as large bubbles. In this state, the surface property seems to be good at first glance, but when the charging member 20 comes into contact with the photosensitive drum 1 and the photosensitive drum 1 rotates, the waste toner that has slipped through the cleaning device 9 is discharged to the charging member 20 and the photosensitive drum 1. This waste toner easily accumulates in a portion where the inside interface of the tube 2c of the charging member 20 is a bubble, and the waste toner is apt to be improperly charged on the image and black spots appear.
【００１９】本発明はこの問題を解消するものである。The present invention solves this problem.
【００２０】[0020]
【課題を解決するための手段】本発明は下記の構成を特
徴とする、帯電部材、帯電装置、画像形成装置、及びプ
ロセスカートリッジである。The present invention is a charging member, a charging device, an image forming apparatus, and a process cartridge, which are characterized by the following configurations.
【００２１】（１）支持部材と、支持部材上に設けられ
た発泡体層と、発泡体層上に設けられたチューブと、を
有する帯電部材において、直径が２００μｍ以下の微小
な穴を有するチューブ内に支持部材を固定した状態で発
泡原料を発泡させて発泡体層を形成し、前記チューブの
外側に表面保護層を有することを特徴とする帯電部材。(1) A charging member having a support member, a foam layer provided on the support member, and a tube provided on the foam layer, wherein the tube has fine holes with a diameter of 200 μm or less. The foam material is foamed with the support member fixed inside to form a foam layer ,
A charging member having a surface protective layer on the outside .
【００２２】（２）支持部材と、支持部材上に設けられ
た発泡体層と、発泡体層上に設けられたチューブと、を
有する帯電部材を被帯電体に当接させて帯電を行う帯電
装置において、帯電部材は、直径が２００μｍ以下の微
小な穴を有するチューブ内に支持部材を固定した状態で
発泡原料を発泡させて発泡体層を形成し、前記チューブ
の外側に表面保護層を有することを特徴とする帯電装
置。 (2) Charging in which a charging member having a supporting member, a foam layer provided on the supporting member, and a tube provided on the foam layer is brought into contact with a member to be charged for charging. in the apparatus, the charging member forms a foam layer by foaming a foaming material in a state where the diameter is fixed to the support member in the tube having the fine holes 200 [mu] m, the tube
A charging device having a surface protective layer on the outside of the charging device.
【００２３】（３）像担持体の帯電手段として、支持部
材と、支持部材上に設けられた発泡体層と、発泡体層上
に設けられたチューブと、を有する帯電部材を像担持体
に当接させて帯電を行う帯電装置を用いた画像形成装置
において、帯電部材は、直径が２００μｍ以下の微小な
穴を有するチューブ内に支持部材を固定した状態で発泡
原料を発泡させて発泡体層を形成し、前記チューブの外
側に表面保護層を有することを特徴とする画像形成装
置。 (3) As a charging means for the image bearing member, a charging member having a supporting member, a foam layer provided on the supporting member, and a tube provided on the foam layer is used as the image bearing member. In an image forming apparatus using a charging device that contacts and charges a foaming material, a charging material is foamed by foaming a foaming raw material in a state in which a supporting member is fixed in a tube having fine holes with a diameter of 200 μm or less. Form the outside of the tube
An image forming apparatus having a surface protective layer on its side .
【００２４】（４）少なくとも、像担持体と、該像担持
体の帯電手段を包含し、画像形成装置に対して着脱され
るプロセスカートリッジにおいて、帯電手段が、支持部
材と、支持部材上に設けられた発泡体層と、発泡体層上
に設けられたチューブと、を有する帯電部材を像担持体
に当接させて帯電を行う帯電装置であり、帯電部材は、
直径が２００μｍ以下の微小な穴を有するチューブ内に
支持部材を固定した状態で発泡原料を発泡させて発泡体
層を形成し、前記チューブの外側に表面保護層を有する
たことを特徴とするプロセスカートリッジ。 (4) In a process cartridge that includes at least an image carrier and a charging unit for the image carrier and is attached to and detached from an image forming apparatus, the charging unit is provided on the support member and the support member. Is a charging device having a charging member having a foam layer provided on the foam layer and a tube provided on the foam layer, and charging the image carrier with the charging member.
A foam layer is formed by foaming a foaming raw material in a state where a supporting member is fixed in a tube having fine holes with a diameter of 200 μm or less, and a surface protective layer is provided outside the tube. Characteristic process cartridge.
【００２５】[0025]
【作用】チューブの内側に芯金を立て、発泡体層の原料
を芯金に差し込み固定させた状態で該原料を発泡させる
ことで芯金とチューブとの間に発泡体層を形成させて発
泡体層・チューブ層を有する帯電部材を構成した場合で
も、チューブと発泡した発泡部材との界面の空気はチュ
ーブに存在させた、直径が２００μｍ以下の微小な穴が
空気抜けとなって該穴から抜け出ることで溜まりを生ぜ
ず、チューブと発泡体層との界面に空気溜まりによる気
泡を生じない。穴は直径２００μｍ以下であってチュー
ブの外側に表面保護層を有することにより、穴によって
表面にへこみが生じることなく帯電ムラを防止できる。 [Function] A core metal is erected inside the tube, and the raw material of the foam layer is inserted into and fixed in the core metal to foam the raw material to form a foam layer between the core metal and the tube. Even when a charging member having a body layer and a tube layer is configured, the air at the interface between the tube and the foamed foam member is allowed to exist in the tube, and minute holes with a diameter of 200 μm or less become air vents, and No air bubbles will be generated due to air traps at the interface between the tube and the foam layer, because no traps will be created by the escape. The hole is 200 μm or less in diameter and
By having a surface protective layer on the outside of the
It is possible to prevent uneven charging without causing dents on the surface.
【００２６】従って、接触帯電部材を構成する発泡体層
とチューブとの界面に空気溜まりが生じることがなくな
り、該空気溜まりの存在に起因する帯電不良の発生が防
止される。そして画像形成装置やプロセスカートリッジ
にあっては該帯電不良による画像不良の発生を防ぐこと
が可能となり常に安定した均一な画像が得られる。チュ
ーブに形成する穴は大きくなると、その部分でローラ面
にへこみが生じ、チューブの外周面を導電層、中抵抗
層、保護層で覆ったとしても、そのへこみは消えないた
め帯電ムラとなってしまう。そのためチューブに形成す
る穴は２００μｍ以下の微少な穴にする。 Therefore, no air pocket is formed at the interface between the foam layer forming the contact charging member and the tube, and the occurrence of charging failure due to the existence of the air pocket is prevented. In the image forming apparatus and the process cartridge, it is possible to prevent the occurrence of image defects due to the charging failure, and it is possible to always obtain a stable and uniform image. Ju
When the hole formed in the groove becomes large, the roller surface
A dent is generated, and the outer peripheral surface of the tube has a conductive layer and medium resistance.
Even if it was covered with a layer and a protective layer, the dent did not disappear
As a result, uneven charging occurs. Therefore, it is formed into a tube
Hole is 200 μm or less.
【００２７】[0027]
【実施例】図１は本発明に従う接触帯電部材もしくは接
触帯電装置の一実施例の横断面模型図、図２はその接触
帯電部材の部分的な縦断面模型図である。DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a cross-sectional model view of an embodiment of a contact charging member or a contact charging device according to the present invention, and FIG. 2 is a partial vertical cross-sectional model view of the contact charging member.
【００２８】図１において、１は被帯電体としての帯電
極性がマイナス又はプラスの回転感光ドラムとする。２
は接触帯電部材としての帯電ローラである。この帯電ロ
ーラ２は支持部材としてのステンレス等でできた金属芯
金２ａと、この芯金２ａの外周に同心一体にローラ状に
形成した発泡部材（発泡体層）２ｂと、この発泡部材２
ｂの外周面をチューブ２ｃで覆い、チューブ２ｃに導電
層２ｄを介して中抵抗層２ｅを形成し、更にその外周面
に保護層２ｆを設けたものである。In FIG. 1, reference numeral 1 designates a rotating photosensitive drum having a negative or positive charging polarity as a member to be charged. Two
Is a charging roller as a contact charging member. The charging roller 2 includes a metal cored bar 2a made of stainless steel or the like as a support member, a foamed member ( foamed layer ) 2b concentrically and integrally formed on the outer periphery of the cored bar 2a, and the foamed member 2
The outer peripheral surface of b is covered with a tube 2c, a medium resistance layer 2e is formed on the tube 2c via a conductive layer 2d, and a protective layer 2f is further provided on the outer peripheral surface thereof.
【００２９】発泡部材２ｂはポリスチレン・ポリオレフ
ィン・ポリエステル・ポリウレタン・ポリアミド系等の
発泡部材や、ＥＰＤＭやウレタンを発泡させた柔軟な部
材に、カーボン・酸化錫等の導電性粉体を分散させて体
積抵抗率を低くした部材である。The foam member 2b is made of a polystyrene / polyolefin / polyester / polyurethane / polyamide foam member or a flexible member made of EPDM or urethane foam, and conductive powder such as carbon / tin oxide is dispersed in the foam member 2b. It is a member with low resistivity.
【００３０】チューブ２ｃはウレタン、スチレンゴム、
ハイパロン等の熱可塑性エラストマーを用いており、帯
電ローラの全体の抵抗が適当な値になるように、チュー
ブ２ｃの抵抗値を定めれば良い。The tube 2c is made of urethane, styrene rubber,
A thermoplastic elastomer such as Hypalon is used, and the resistance value of the tube 2c may be determined so that the overall resistance of the charging roller is an appropriate value.
【００３１】本実施例では発泡させたポリウレタンにカ
ーボンを分散させている。２ｂ1 は発泡部材２ｂの気泡
部（空気・窒素・アルゴンガス等の封入気泡）である。In this embodiment, carbon is dispersed in foamed polyurethane. 2b 1 is a bubble part (enclosed bubble of air, nitrogen, argon gas, etc.) of the foam member 2b.
【００３２】本実施例における帯電ローラ２の具体的な
仕様は下記の通りである。The specific specifications of the charging roller 2 in this embodiment are as follows.
【００３３】芯金２ａ ；直径６ｍｍ、長さ２６０ｍ
ｍのステンレス丸棒
発泡部材２ｂ；カーボン分散の発泡エピクロルヒドリン
ゴム
体積抵抗値１０2 Ωｃｍ〜１０5 Ωｃｍ
層厚２．６ｍｍ、長さ２３０ｍｍ
チューブ２ｃ；ポリウレタン熱可塑性エラストマー
体積抵抗値１０4 Ωｃｍ〜１０8 Ωｃｍ
層厚２５０μｍ
導電層２ｄ ；EPDMやウレタンに多量のカーボン・酸化
錫等の導電性粉体を分散させたもの
体積抵抗値１０2 Ωｃｍ〜１０5 Ωｃｍ
層厚１０μｍ
中抵抗層２ｅ；エピクロルヒドリンゴム
体積抵抗値１０7 Ωｃｍ〜１０10 Ωｃｍ
層厚１８０μｍ
保護層２ｆ ；Ｎ−メトキシメチル化ナイロン
体積抵抗値１０7 Ωｃｍ〜１０11 Ωｃｍ
層厚５μｍ
帯電ローラ２の重量７０ｇ、硬度４０度〜５０度(ASKER
-C)
感光ドラム１に対する押圧力 総圧１０００ｇ
上記帯電ローラ２において、芯金２ａからチューブ２ｃ
へ電荷が一様に供給できずにチューブ２ｃ表面上での電
荷量が不均一になるのを防止するため、チューブ２ｃの
外周面に体積抵抗値の低い導電層２ｄを設けてある。Core metal 2a; diameter 6 mm, length 260 m
m stainless round bar foam member 2b; carbon dispersion foamed epichlorohydrin rubber volume resistance value 10 2 Ωcm to 10 5 Ωcm layer thickness 2.6 mm, length 230 mm tube 2c; polyurethane thermoplastic elastomer volume resistance value 10 4 Ωcm to 10 8 Ωcm Layer thickness 250 μm Conductive layer 2d; A large amount of conductive powder such as carbon / tin oxide dispersed in EPDM or urethane Volume resistance value 10 2 Ωcm to 10 5 Ωcm Layer thickness 10 μm Medium resistance layer 2e; Epichlorohydrin rubber volume Resistance value 10 7 Ωcm to 10 10 Ωcm Layer thickness 180 μm Protective layer 2f; N-methoxymethyl nylon volume resistance value 10 7 Ωcm to 10 11 Ωcm Layer thickness 5 μm Charging roller 2 weight 70 g, hardness 40 degrees to 50 degrees (ASKER)
-C) Pressing force on the photosensitive drum 1 Total pressure 1000g In the above charging roller 2, the core metal 2a to the tube 2c
In order to prevent the charge from being uniformly supplied to the surface of the tube 2c and prevent the charge from becoming uneven on the surface of the tube 2c, a conductive layer 2d having a low volume resistance value is provided on the outer peripheral surface of the tube 2c.
【００３４】また中抵抗層２ｅの外周面に設けた保護層
２ｆは感光ドラム１の表層に対し相性の良い材料を使用
することで、感光ドラム１、帯電ローラ２の表層の汚染
を防ぐことができる。The protective layer 2f provided on the outer peripheral surface of the medium resistance layer 2e is made of a material having a good compatibility with the surface layer of the photosensitive drum 1, so that the surface layer of the photosensitive drum 1 and the charging roller 2 can be prevented from being contaminated. it can.
【００３５】チューブ２ｃの表面には、図３のように、
長手方向に１５個、周方向に６ヶ所の微少な穴２ｇを開
けてある。穴２ｇの大きさは直径２０μｍである。On the surface of the tube 2c, as shown in FIG.
There are 15 small holes 2g in the longitudinal direction and 6 in the circumferential direction. The size of the hole 2g is 20 μm in diameter.
【００３６】而して、前述図９と同じ要領でチューブ２
ｇの内側に芯金２ａを立て、発泡部材２ｂの原料（２ｂ
2 ）を芯金２ａに差し込み固定させた状態で該原料を発
泡ａさせることで芯金２ａとチューブ２ｃとの間に発泡
部材２ｂを形成させた。Then, the tube 2 is processed in the same manner as in FIG.
The core metal 2a is erected inside the g, and the raw material (2b
2 ) was inserted into the core metal 2a and fixed, and the raw material was foamed a to form a foam member 2b between the core metal 2a and the tube 2c.
【００３７】この場合、チューブ２ｃと発泡した発泡部
材２ｂとの界面の空気はチューブ２ｃに開けてある上述
の穴２ｇから抜け出ることで溜まりを生ぜず、チューブ
２ｃと発泡部材２ｂとの界面に空気溜まりによる気泡を
生じない。In this case, the air at the interface between the tube 2c and the foamed foam member 2b escapes from the above-described hole 2g formed in the tube 2c and does not form a pool, and the air at the interface between the tube 2c and the foam member 2b does not form. Does not generate bubbles due to accumulation.
【００３８】次いで、チューブ２ｃの外周面に導電層２
ｄ、中抵抗層２ｅ、保護層２ｆを順次に形成処置して帯
電ローラ２を作製した。この帯電ローラ２はチューブ２
ｃと発泡部材２ｂとの界面に空気溜まりによる気泡がな
く、そのような気泡の存在に起因する帯電ムラがなく、
安定した画像が得られるようになった。Then, the conductive layer 2 is formed on the outer peripheral surface of the tube 2c.
Then, the charging roller 2 was manufactured by sequentially forming d, the medium resistance layer 2e, and the protective layer 2f. This charging roller 2 is a tube 2
There are no bubbles due to air traps at the interface between c and the foam member 2b, and there is no charging unevenness due to the presence of such bubbles,
A stable image can now be obtained.
【００３９】チューブ２ｃに形成する穴２ｇは大きくな
ると、その部分でローラ面にへこみが生じ、チューブ２
ｃの外周面を導電層２ｄ、中抵抗層２ｅ、保護層２ｆで
覆ったとしても、そのへこみは消えないため帯電ムラと
なってしまう。そのため２００μｍ以下の微少な穴であ
ることが望ましい。When the hole 2g formed in the tube 2c becomes large, the roller surface is indented at that portion, and the tube 2c
Even if the outer peripheral surface of c is covered with the conductive layer 2d, the medium resistance layer 2e, and the protective layer 2f, the dents do not disappear, resulting in uneven charging. Therefore, it is desirable that the holes have a size of 200 μm or less.
【００４０】またチューブ２ｃの長手方向、周方向上の
穴の数が異常に多い場合、穴と穴との間隔が狭くなり、
２つの穴の間でへこみとなってしまうため、上記と同様
な帯電ムラとなってしまう。逆に穴の数が少ないと、空
気が抜ける量が少なくなってしまい、気泡ができ易い。
故に、穴の数はへこみとならない程度に多くすることが
大切である。When the number of holes in the longitudinal and circumferential directions of the tube 2c is abnormally large, the distance between the holes becomes narrow,
Since a dent is formed between the two holes, charging unevenness similar to the above occurs. On the contrary, if the number of holes is small, the amount of air escaped is small, and bubbles are easily formed.
Therefore, it is important to make the number of holes large enough not to cause dents.
【００４１】図４の（ａ）〜（ｃ）はそれぞれチューブ
２ｃに対する穴２ｇの他の形成形態例を示した。FIGS. 4 (a) to 4 (c) show other examples of the form of the hole 2g for the tube 2c.
【００４２】（ａ）は穴２ｇの位置をチューブ２ｃの長
手方向に螺旋状にしたものである。In (a), the position of the hole 2g is made spiral in the longitudinal direction of the tube 2c.
【００４３】（ｂ）はチューブ２ｃの表面上にランダム
に穴２ｇを開けたものである。In (b), holes 2g are randomly formed on the surface of the tube 2c.
【００４４】（ｃ）は帯電ローラ２の長手方向の両端部
から中心部に向かい穴２ｇの数を多くしたものである。
これは発泡部材２ｂの原料（２ｂ2 ）を発泡させた場
合、帯電ローラ２の長手方向の中心部の発泡部材２ｂと
チューブ２ｃの界面で気泡ができ易いため、それを防止
するためである。In (c), the number of holes 2g is increased from both ends in the longitudinal direction of the charging roller 2 toward the center.
This is because when the raw material (2b 2 ) of the foaming member 2b is foamed, bubbles easily form at the interface between the foaming member 2b and the tube 2c at the center of the charging roller 2 in the longitudinal direction, and this is prevented.
【００４５】帯電部材２は実施例のローラタイプに限ら
ず、ブレード形・パッド形など他の形状形態のものであ
ってもよく、この場合も弾性層を発泡部材とし、その表
面をチューブで覆わせた構成のものとした場合に本発明
を適用できる。The charging member 2 is not limited to the roller type of the embodiment, but may have other shapes such as a blade type and a pad type. In this case, the elastic layer is a foam member and the surface thereof is covered with a tube. The present invention can be applied to the case of the combined configuration.
【００４６】図５は前述図１・２の接触帯電部材もしく
は接触帯電装置を像担持体の一次帯電手段として用いた
画像形成装置もしくはプロセスカートリッジの一例の概
略構成図を示すものである。FIG. 5 is a schematic diagram showing an example of an image forming apparatus or a process cartridge using the contact charging member or the contact charging device of FIGS. 1 and 2 as the primary charging means of the image carrier.
【００４７】本例の画像形成装置は転写式電子写真プロ
セスの利用のプロセスカートリッジ着脱式のレーザービ
ームプリンターである。前述図６の装置と共通する構成
部材・機器には同一の符号を付して再度の説明を省略す
る。The image forming apparatus of this embodiment is a laser beam printer of a process cartridge detachable type which utilizes a transfer type electrophotographic process. The same components and devices as those of the apparatus shown in FIG. 6 are designated by the same reference numerals, and the repeated description will be omitted.
【００４８】像担持体としての感光ドラム１はその回転
過程で前述図１・２の帯電部材としての帯電ローラ２に
より一次帯電処理を受け、レーザースキャナ５Ａから出
力される、目的の画像情報の時系列電気デジタル画素信
号に対応して変調されたレーザービームによる走査露光
を受けることで、回転ドラム周面に目的の画像情報に対
応した静電潜像が形成されていく。The photosensitive drum 1 as an image carrier is subjected to a primary charging process by the charging roller 2 as a charging member shown in FIGS. 1 and 2 in the course of its rotation, and when the desired image information is output from the laser scanner 5A. By receiving scanning exposure with the laser beam modulated corresponding to the series electric digital pixel signal, an electrostatic latent image corresponding to the target image information is formed on the peripheral surface of the rotating drum.
【００４９】その静電潜像が現像装置６によりトナー画
像として現像されて転写部位Ｎにて転写材７に転写され
る。８Ａは転写ローラ８に対する電圧印加電源である。The electrostatic latent image is developed as a toner image by the developing device 6 and transferred to the transfer material 7 at the transfer portion N. 8A is a voltage application power source for the transfer roller 8.
【００５０】トナー画像の転写を受けた転写材７は搬送
装置２４で定着装置２５へ導入されてトナー画像の定着
処理を受け、機外の排紙トレイ２６へ排出される。The transfer material 7 to which the toner image has been transferred is introduced into the fixing device 25 by the conveying device 24, undergoes the fixing process of the toner image, and is discharged to the paper discharge tray 26 outside the machine.
【００５１】２１は転写材７を積載収納させた、プリン
ター本体に対して着脱自在の給紙カセットであり、給紙
ローラ２２と不図示の分離手段により上のものから１枚
宛繰り出され、レジストローラ対２３でタイミングどり
されて転写部位Ｎへ導入される。Reference numeral 21 denotes a paper feed cassette in which the transfer material 7 is stacked and stored, and which is detachable from the printer main body, and is fed out one by one from above by a paper feed roller 22 and a separating means (not shown). It is introduced to the transfer site N at a timed timing by the roller pair 23.
【００５２】転写後の感光ドラム１面はクリーニング装
置９で清掃されて繰り返して作像に供される。After the transfer, the surface of the photosensitive drum 1 is cleaned by the cleaning device 9 and repeatedly used for image formation.
【００５３】本例装置においては、感光ドラム１、帯電
ローラ２、現像装置６、クリーニング装置９の４つのプ
ロセス機器を共通のハウジング３１に組み込んで一括し
てプリンター本体に対して着脱交換自在のプロセスカー
トリッジ３０としてある。In the apparatus of this embodiment, four processes including the photosensitive drum 1, the charging roller 2, the developing device 6, and the cleaning device 9 are incorporated into a common housing 31 and are detachably replaceable with respect to the printer main body. It is as a cartridge 30.
【００５４】このプロセスカートリッジ３０は、プリン
ター本体の上側筐体を開いてプリンター内を開放して、
或いはプリンター本体の正面扉板を開いて装置内を開放
し、或いはその他の手段構成にてプリンター内の所定の
位置に着脱操作される。In this process cartridge 30, the upper casing of the printer main body is opened to open the inside of the printer,
Alternatively, the front door plate of the printer main body is opened to open the inside of the apparatus, or the printer is attached / detached to / from a predetermined position in the printer by other means.
【００５５】プロセスカートリッジ３０がプリンター内
に所定に装着されることで、プリンター本体側とプロセ
スカートリッジ３０側とが機械的・電気的にカップリン
グしてプリント実行可能な状態となる。When the process cartridge 30 is mounted in the printer in a predetermined manner, the printer main body side and the process cartridge 30 side are mechanically and electrically coupled to each other so that printing can be performed.
【００５６】[0056]
【発明の効果】以上のように本発明によれば、接触帯電
部材を構成する発泡体層とチューブとの界面に空気溜ま
りが生じることがなくなり、該空気溜まりの存在に起因
する帯電不良の発生が防止される。そして画像形成装置
やプロセスカートリッジにあっては該帯電不良による画
像不良の発生を防ぐことが可能となり常に安定した均一
な画像が得られる。As described above, according to the present invention, no air pockets are formed at the interface between the foam layer and the tube constituting the contact charging member, and the occurrence of charging failure due to the existence of the air pockets. Is prevented. In the image forming apparatus and the process cartridge, it is possible to prevent the occurrence of image defects due to the charging failure, and it is possible to always obtain a stable and uniform image.
【図１】 一実施例の接触帯電ローラの層構成を示す横
断面模型図FIG. 1 is a schematic cross-sectional view showing a layer structure of a contact charging roller according to an embodiment.
【図２】 一部の縦断面模型図[Figure 2] Partial vertical section model
【図３】 空気抜き穴を具備させたチューブの斜視図FIG. 3 is a perspective view of a tube provided with an air vent hole.
【図４】 （ａ）・（ｂ）・（ｃ）はそれぞれ空気抜き
穴の他の形成形態例を示したチューブの斜視図4 (a), (b), and (c) are perspective views of a tube showing another example of formation of air vent holes.
【図５】 画像形成装置の一例の概略構成図FIG. 5 is a schematic configuration diagram of an example of an image forming apparatus.
【図６】 従来例としての画像形成装置の一例の概略構
成図FIG. 6 is a schematic configuration diagram of an example of an image forming apparatus as a conventional example.
【図７】 接触帯電ローラの層構成を示す横断面模型図FIG. 7 is a schematic cross-sectional view showing the layer structure of the contact charging roller.
【図８】 該帯電ローラの作製要領説明図（その１）FIG. 8 is an explanatory diagram of the manufacturing procedure of the charging roller (No. 1)
【図９】 該帯電ローラの作製要領説明図（その２）FIG. 9 is an explanatory diagram of the manufacturing procedure of the charging roller (No. 2)
１ 被帯電体としての感光ドラム ２ 帯電部材としての帯電ローラ ２ａ 芯金棒 ２ｂ 弾性導電層としての発泡部材 ２ｃ チューブ ２ｇ 空気抜き穴 ２ｄ 導電層 ２ｅ 中抵抗層 ２ｆ 保護層 1 Photosensitive drum as charged body 2 Charging roller as charging member 2a Core bar 2b Foamed member as elastic conductive layer 2c tube 2g air vent hole 2d conductive layer 2e Medium resistance layer 2f protective layer
───────────────────────────────────────────────────── フロントページの続き (56)参考文献 特開 平１−191880（ＪＰ，Ａ) 特開 昭50−6668（ＪＰ，Ａ) 特開 平５−248426（ＪＰ，Ａ) 特開 平２−110045（ＪＰ，Ａ) 特開 昭53−40068（ＪＰ，Ａ) ─────────────────────────────────────────────────── ─── Continued front page (56) References JP-A-1-191880 (JP, A) JP-A-50-6668 (JP, A) JP-A-5-248426 (JP, A) Japanese Patent Laid-Open No. 2-110045 (JP, A) JP-A-53-40068 (JP, A)
Claims (4)
泡体層と、発泡体層上に設けられたチューブと、を有す
る帯電部材において、 直径が２００μｍ以下の微小な穴を有するチューブ内に
支持部材を固定した状態で発泡原料を発泡させて発泡体
層を形成し、前記チューブの外側に表面保護層を有する
ことを特徴とする帯電部材。1. A charging member having a support member, a foam layer provided on the support member, and a tube provided on the foam layer, wherein the inside of the tube has minute holes with a diameter of 200 μm or less. A charging member characterized in that a foaming material is foamed to form a foam layer with the support member fixed to the surface of the tube, and a surface protection layer is provided outside the tube .
泡体層と、発泡体層上に設けられたチューブと、を有す
る帯電部材を被帯電体に当接させて帯電を行う帯電装置
において、 帯電部材は、直径が２００μｍ以下の微小な穴を有する
チューブ内に支持部材を固定した状態で発泡原料を発泡
させて発泡体層を形成し、前記チューブの外側に表面保
護層を有することを特徴とする帯電装置。 2. A charging device for charging by charging a charging member having a support member, a foam layer provided on the support member, and a tube provided on the foam layer, against a member to be charged. In the charging member, the foaming raw material is foamed in a state where the supporting member is fixed in a tube having fine holes with a diameter of 200 μm or less to form a foam layer, and the surface protection is provided on the outside of the tube.
A charging device having a protective layer .
と、支持部材上に設けられた発泡体層と、発泡体層上に
設けられたチューブと、を有する帯電部材を像担持体に
当接させて帯電を行う帯電装置を用いた画像形成装置に
おいて、 帯電部材は、直径が２００μｍ以下の微小な穴を有する
チューブ内に支持部材を固定した状態で発泡原料を発泡
させて発泡体層を形成し、前記チューブの外側に表面保
護層を有することを特徴とする画像形成装置。 3. A charging member having a supporting member, a foam layer provided on the supporting member, and a tube provided on the foam layer as a charging means for the image bearing member is applied to the image bearing member. In an image forming apparatus using a charging device that contacts and charges, a charging member is formed by foaming a foaming raw material while a supporting member is fixed in a tube having fine holes with a diameter of 200 μm or less to form a foam layer. Form and keep the surface on the outside of the tube.
An image forming apparatus having a protective layer .
帯電手段を包含し、画像形成装置に対して着脱されるプ
ロセスカートリッジにおいて、 帯電手段が、支持部材と、支持部材上に設けられた発泡
体層と、発泡体層上に設けられたチューブと、を有する
帯電部材を像担持体に当接させて帯電を行う帯電装置で
あり、帯電部材は、直径が２００μｍ以下の微小な穴を
有するチューブ内に支持部材を固定した状態で発泡原料
を発泡させて発泡体層を形成し、前記チューブの外側に
表面保護層を有することを特徴とするプロセスカートリ
ッジ。 4. A process cartridge that includes at least an image carrier and a charging unit for the image carrier and is attached to and detached from an image forming apparatus, wherein the charging unit is provided on a supporting member and on the supporting member. A charging device having a foam layer and a tube provided on the foam layer for charging by charging the charging member to the image carrier, and the charging member is a minute hole having a diameter of 200 μm or less. A foam layer is formed by foaming the foaming raw material with the supporting member fixed in the tube having
A process cartridge having a surface protective layer .
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP29142193A JP3517439B2 (en) | 1993-10-27 | 1993-10-27 | Charging member, charging device, image forming apparatus, and process cartridge |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP29142193A JP3517439B2 (en) | 1993-10-27 | 1993-10-27 | Charging member, charging device, image forming apparatus, and process cartridge |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH07121014A JPH07121014A (en) | 1995-05-12 |
| JP3517439B2 true JP3517439B2 (en) | 2004-04-12 |
Family
ID=17768666
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP29142193A Expired - Fee Related JP3517439B2 (en) | 1993-10-27 | 1993-10-27 | Charging member, charging device, image forming apparatus, and process cartridge |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP3517439B2 (en) |
-
1993
- 1993-10-27 JP JP29142193A patent/JP3517439B2/en not_active Expired - Fee Related
Also Published As
| Publication number | Publication date |
|---|---|
| JPH07121014A (en) | 1995-05-12 |
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