JPH03251879A - Developing device - Google Patents
Developing deviceInfo
- Publication number
- JPH03251879A JPH03251879A JP2050251A JP5025190A JPH03251879A JP H03251879 A JPH03251879 A JP H03251879A JP 2050251 A JP2050251 A JP 2050251A JP 5025190 A JP5025190 A JP 5025190A JP H03251879 A JPH03251879 A JP H03251879A
- Authority
- JP
- Japan
- Prior art keywords
- sleeve
- roller
- drive roller
- developing device
- driving roller
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
- 239000000696 magnetic material Substances 0.000 claims abstract description 9
- 239000004417 polycarbonate Substances 0.000 abstract description 11
- 239000011347 resin Substances 0.000 abstract description 7
- 229920005989 resin Polymers 0.000 abstract description 7
- 230000005291 magnetic effect Effects 0.000 abstract description 4
- 230000005415 magnetization Effects 0.000 abstract description 4
- 239000010409 thin film Substances 0.000 abstract description 4
- 239000004677 Nylon Substances 0.000 abstract description 2
- 230000000694 effects Effects 0.000 abstract description 2
- 239000003302 ferromagnetic material Substances 0.000 abstract description 2
- 239000000463 material Substances 0.000 abstract description 2
- 229920001778 nylon Polymers 0.000 abstract description 2
- 229920000515 polycarbonate Polymers 0.000 abstract description 2
- 230000001105 regulatory effect Effects 0.000 description 3
- 230000007423 decrease Effects 0.000 description 2
- 238000010586 diagram Methods 0.000 description 2
- 239000002184 metal Substances 0.000 description 2
- 229910052751 metal Inorganic materials 0.000 description 2
- 239000000843 powder Substances 0.000 description 2
- 230000007547 defect Effects 0.000 description 1
- NBVXSUQYWXRMNV-UHFFFAOYSA-N fluoromethane Chemical compound FC NBVXSUQYWXRMNV-UHFFFAOYSA-N 0.000 description 1
- 230000007774 longterm Effects 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 108091008695 photoreceptors Proteins 0.000 description 1
- 230000003068 static effect Effects 0.000 description 1
- 238000003756 stirring Methods 0.000 description 1
- 229910000859 α-Fe Inorganic materials 0.000 description 1
Landscapes
- Dry Development In Electrophotography (AREA)
- Magnetic Brush Developing In Electrophotography (AREA)
Abstract
Description
【発明の詳細な説明】
〔産業上の利用分野〕
本発明は、プリンタ、複写機等の画像形成装置における
現像装置に関する。DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a developing device in an image forming apparatus such as a printer or a copying machine.
画像形成装置における現像装置の一つに、駆動ローラに
該ローラ外径より若干大きい内径を有する可撓性のある
現像剤担持用薄肉スリーブを外嵌し、該スリーブを一方
側から前記駆動ローラに押圧して他方側にたるみ部分を
形成しつつ該たるみ部分を静電潜像担持体に接触させる
現像装置がある。第６図はこの種の現像装置の一例を示
している。第６図に示す現像装置は、現像用トナーから
なる一成分現像剤りを収容するケーシング４に図示しな
い駆動手段により回される駆動ローラ１を設けるととも
に、該ローラに薄肉の現像剤担持用スリーブ２を外嵌し
たものである。In one of the developing devices in the image forming apparatus, a flexible thin sleeve for carrying developer having an inner diameter slightly larger than the outer diameter of the drive roller is fitted onto the drive roller, and the sleeve is attached to the drive roller from one side. There is a developing device that presses to form a slack portion on the other side and brings the slack portion into contact with the electrostatic latent image carrier. FIG. 6 shows an example of this type of developing device. The developing device shown in FIG. 6 is provided with a drive roller 1 rotated by a drive means (not shown) in a casing 4 containing a one-component developer consisting of toner for development, and a thin developer-carrying sleeve attached to the roller. 2 is fitted externally.
スリーブ２はその回転軸線方向両端部の外周面に半円状
に当接するガイド部材３（一つだけ図示）によりケーシ
ング４内側から駆動ローラ１に圧接されており、それに
よってケーシング外側にたるみ部分２０が形成されでお
り、このたるみ部分が静電潜像担持体である感光体ドラ
ムＰＣに接触している。The sleeve 2 is pressed against the drive roller 1 from inside the casing 4 by guide members 3 (only one shown) that abut semicircularly on the outer circumferential surface of both ends in the direction of the rotational axis, thereby creating a slack portion 20 on the outside of the casing. is formed, and this slack portion is in contact with the photosensitive drum PC, which is an electrostatic latent image carrier.
ケーシング４内の現像剤りは撹拌回転羽根４１によって
撹拌されつつスリーブ２上へ送り込まれる。また、ケー
シング内では、スリーブ２表面に規制部材であるブレー
ド４２が当接しており、この規制部材はスリーブ２の押
圧に若干寄与するとともに現像剤りの帯電量およびスリ
ーブ２表面への付着量を規制する。駆動ローラ１が図示
しない駆動手段により第６図中矢印方向に回されると、
主としてガイド部材３の圧接力に起因する駆動ローラ１
表面とスリーブ２内面との摩擦によりスリーブ２も同方
向に回転する。The developer in the casing 4 is fed onto the sleeve 2 while being stirred by the stirring rotary blade 41. In addition, within the casing, a blade 42 that is a regulating member is in contact with the surface of the sleeve 2, and this regulating member slightly contributes to pressing the sleeve 2 and also controls the amount of charge of the developer and the amount of adhesion to the surface of the sleeve 2. regulate. When the drive roller 1 is rotated in the direction of the arrow in FIG. 6 by a drive means (not shown),
The drive roller 1 is mainly caused by the pressure contact force of the guide member 3.
The sleeve 2 also rotates in the same direction due to friction between the surface and the inner surface of the sleeve 2.
かくして感光体ＰＣ上の静電潜像は現像される。In this way, the electrostatic latent image on the photoreceptor PC is developed.
しかしながら、前記従来現像装置によると、スリーブ２
をガイド部材３によって駆動ローラ１に圧接させ、主と
してこの圧接力に基づく駆動ローラ１とスリーブ２との
間の摩擦力によって、スリーブ２を駆動ローラ１の回転
に伴って駆動させるようにしているため、長期使用する
と次第に駆動ローラエの表面が摩耗し、そのためローラ
１およびスリーブ２間の摩擦力が小さくなり、両者間に
スリップが生じ易くなり、このスリップのため現像剤の
搬送量が変動し、画像上に濃度むらやピッチむらが発生
するという問題がある。However, according to the conventional developing device, the sleeve 2
is brought into pressure contact with the drive roller 1 by the guide member 3, and the sleeve 2 is driven as the drive roller 1 rotates mainly due to the frictional force between the drive roller 1 and the sleeve 2 based on this pressure contact force. After long-term use, the surface of the drive roller gradually wears out, and as a result, the frictional force between the roller 1 and the sleeve 2 decreases, making it easy for slips to occur between them.This slip causes fluctuations in the amount of developer conveyed, causing the image to deteriorate. There is a problem in that density unevenness and pitch unevenness occur on the top.
また、ガイド部材３は、スリーブ２の両端部にのみ接触
するため、スリーブ２の前記たるみ部分２０がスリーブ
回転軸線方向にわたって一様に形成されず、中央部分で
たるみ量が少なくなり、その結果、静電潜像担持体ＰＣ
とスリーブ２とのニップ幅Ｗが第７図に示すようにスリ
ーブ２の中央部分で少なくなり、これが画像欠損を引き
起こすという問題がある。Further, since the guide member 3 contacts only both ends of the sleeve 2, the slack portion 20 of the sleeve 2 is not formed uniformly in the direction of the sleeve rotation axis, and the amount of slack in the central portion is small. Electrostatic latent image carrier PC
There is a problem in that the nip width W between the sleeve 2 and the sleeve 2 decreases at the center of the sleeve 2, as shown in FIG. 7, and this causes image defects.
そこで本発明は、前述の従来現像装置におけるこのよう
な問題を解決することを課題とする。Therefore, it is an object of the present invention to solve these problems in the conventional developing device described above.
〔課題を解決するための手段］
本発明は前記課題を解決するため、駆動ローラに該ロー
ラ外径より若干大きい内径を有する現像剤担持用スリー
ブを外嵌し、該スリーブを一方側から前記駆動ローラに
圧接して他方側にたるみ部分を形成しつつ該たるみ部分
を静電潜像担持体に接触させる現像装置において、前記
駆動ローラおよび前記スリーブのうちいずれか一方に着
磁するとともに他方の少なくとも一部を該着磁部分によ
り吸引力を受ける磁性材料で形成したことを特徴とする
現像装置を提供するものである。[Means for Solving the Problems] In order to solve the above-mentioned problems, the present invention includes a developer-carrying sleeve having an inner diameter slightly larger than the outer diameter of the drive roller, and a sleeve for carrying developer having an inner diameter slightly larger than the outer diameter of the drive roller. In a developing device that presses a roller to form a slack portion on the other side and brings the slack portion into contact with an electrostatic latent image carrier, one of the drive roller and the sleeve is magnetized, and at least one of the other side is magnetized. The object of the present invention is to provide a developing device characterized in that a portion thereof is formed of a magnetic material that receives an attractive force from the magnetized portion.
本発明によると、駆動ローラおよびこれに外装されたス
リーブのいずれか一方が着磁され、他方の少なくとも一
部が該着磁部分に吸引される磁性材料で形成されている
ため、スリーブは磁力の作用も受けてその回転軸線方向
にわたり一様に駆動ローラに密着し、駆動ローラの回転
に円滑に従動回転するとともに、スリーブのたるみ部分
がローラ回転軸線方向にわたり一様に形成され、従って
スリーブと静電潜像担持体のニップ幅も全体−様なもの
となる。According to the present invention, either the drive roller or the sleeve sheathed thereon is magnetized, and at least a portion of the other is made of a magnetic material that is attracted to the magnetized portion, so that the sleeve is free from magnetic force. In addition, the slack portion of the sleeve is uniformly formed along the roller rotation axis, and the sleeve and static The nip width of the latent image carrier also becomes similar to that of the whole.
〔実 施 例］ 以下、本発明の実施例を図面を参照して説明する。〔Example] Embodiments of the present invention will be described below with reference to the drawings.
第１図に示す一実施例現像装置は駆動ローラ５およびス
リーブ６を除いて第６図に示す従来現像装置と同構造で
あり、同一符号で示されている部分は同構造であり、同
様に作用する。従って、それらの詳細説明は省略する。The developing device according to the embodiment shown in FIG. 1 has the same structure as the conventional developing device shown in FIG. 6 except for the drive roller 5 and the sleeve 6, and the parts indicated by the same reference numerals have the same structure and are similar. act. Therefore, detailed explanation thereof will be omitted.
スリーブ６はその内径が駆動ローラ５の外径よりやや大
きく、駆動ローラ５に外嵌されている。The sleeve 6 has an inner diameter slightly larger than the outer diameter of the drive roller 5, and is fitted around the drive roller 5.
スリーブ６の両端部、換言すれば静電潜像担持体である
感光体ドラムＰＣと対面する現像領域部分の外側の部分
がそれぞれガイド部材３によりケーシング４内側から駆
動ローラ１に圧接されており、それによってケーシング
外側にたるみ部分６ｏが形成されており、このたるみ部
分が感光体ドラムＰＣに接触している。Both end portions of the sleeve 6, in other words, the outer portions of the development area facing the photosensitive drum PC, which is an electrostatic latent image carrier, are pressed against the drive roller 1 from the inside of the casing 4 by guide members 3, respectively. As a result, a slack portion 6o is formed on the outside of the casing, and this slack portion is in contact with the photosensitive drum PC.
また、スリーブ６にはケーシング４内に架設した規制部
材であるブレード４２が当接している。Further, a blade 42 that is a regulating member installed within the casing 4 is in contact with the sleeve 6 .
駆動ローラ５は図示しないモータ等の駆動手段により図
中矢印方向に駆動回転し、これに伴ってスリーブ６も同
方向に回転する。The drive roller 5 is driven and rotated in the direction of the arrow in the figure by a drive means such as a motor (not shown), and the sleeve 6 is accordingly rotated in the same direction.
スリーブ６としては、例えばポリカーボネート、ナイロ
ン、フッソ系樹脂等の樹脂に保持力（磁化させたときの
残留磁界）の大きい磁石材料（ＦｅＣＯ粉末、Ｃｏ粉末
、７ ＦｅｚＯ＋、Ｃｏフェライト等）を分散混入さ
せ、薄膜スリーブ状に形成したのち、着磁したもの、ま
たはＮｉ等の金属薄膜スリーブ上に前記磁石材料を分散
混入した樹脂をシート状に積層したのち、該樹脂層に同
様に着磁したもの、金属薄膜スリーブに直接着磁したも
のが考えられるが、本実施例では磁石材料を分散混入し
た樹脂からなるものである。The sleeve 6 is made by dispersing and mixing a magnetic material (FeCO powder, Co powder, 7 FezO+, Co ferrite, etc.) with a large coercive force (residual magnetic field when magnetized) into a resin such as polycarbonate, nylon, or fluorocarbon resin. , formed into a thin film sleeve shape and then magnetized, or a metal thin film sleeve made of Ni or the like, a resin containing the magnetic material dispersed therein is laminated in a sheet shape, and then the resin layer is similarly magnetized; Although it is conceivable to directly magnetize a metal thin film sleeve, in this embodiment it is made of resin in which magnet material is dispersed.
一方、駆動ローラ５はその全体が比較的保持力の小さな
強磁性材料（Ｆｅ、Ｃｏ、Ｎｉ等）で構成されている。On the other hand, the entire driving roller 5 is made of a ferromagnetic material (Fe, Co, Ni, etc.) with a relatively small coercive force.
なお、ローラ５の表面部等のみを該磁性材料で形成する
ことも考えられる。Note that it is also possible to form only the surface portion of the roller 5 with the magnetic material.
前記スリーブ６の着磁パターンとしては種々のものが考
えられるが、例示すると第２図から第４図に示すとおり
である。Although various magnetization patterns can be considered for the sleeve 6, examples thereof are shown in FIGS. 2 to 4.
第２図に示すパターンはスリーブ６の厚み方向にＮ極お
よびＳ極が交互に配置されたパターンである。第３図に
示すパターンはスリーブ６の円周方向にＮ極およびＳ極
が交互に配置されたパターンである。第４図のパターン
はスリーブにその回転軸線方向および円周方向のそれぞ
れにＮ極およびＳ極が交互に配置されたパターンである
。The pattern shown in FIG. 2 is a pattern in which north poles and south poles are alternately arranged in the thickness direction of the sleeve 6. The pattern shown in FIG. 3 is a pattern in which north poles and south poles are alternately arranged in the circumferential direction of the sleeve 6. The pattern shown in FIG. 4 is a pattern in which north poles and south poles are alternately arranged on the sleeve in the rotational axis direction and the circumferential direction, respectively.
この現像装置によると、スリーブ６はガイド部材３によ
る圧接力とともにスリーブ６の着磁による磁力の作用も
受けて回転軸線方向にわたり一様に駆動ローラに密着す
る。従ってスリーブ６は駆動ローラ５の回転に円滑に従
動して回転する。また、スリーブ６のたるみ部分６０が
スリーブ回転軸線方向にわたり一様に形成され、従って
スリーブ６と感光体ドラムＰＣのニップ幅Ｗも第５図に
示すように全体−様なものとなる。According to this developing device, the sleeve 6 is uniformly brought into close contact with the drive roller along the rotational axis direction due to the pressure force exerted by the guide member 3 as well as the magnetic force generated by the magnetization of the sleeve 6 . Therefore, the sleeve 6 rotates smoothly following the rotation of the drive roller 5. Further, the slack portion 60 of the sleeve 6 is formed uniformly in the direction of the sleeve rotation axis, so that the nip width W between the sleeve 6 and the photosensitive drum PC is also uniform throughout as shown in FIG.
以上説明した点を除く他の部分の動作は第６図に示す従
来現像装置におけるものと同様である。The operations of other parts except for the points described above are the same as those in the conventional developing device shown in FIG.
前記本発明にかかる現像装置によると、スリーブ６は駆
動ローラ５の回転に円滑に従動し、駆動ローラ５に対し
てスリップする恐れがなく、また、スリーブ６と感光体
ドラムＰＣとのニップ幅Ｗも全体−様なものとなるから
、安定した現像剤搬送が行われ、最終画質も向上する。According to the developing device according to the present invention, the sleeve 6 smoothly follows the rotation of the drive roller 5, there is no risk of slipping against the drive roller 5, and the nip width W between the sleeve 6 and the photosensitive drum PC is small. Since the entire surface of the image is similar to that of the original image, stable developer transport is achieved and the final image quality is also improved.
なお、本発明は前記実施例に限定されるものではなく、
他にも種々の態様で実施することができる。Note that the present invention is not limited to the above embodiments,
It can also be implemented in various other ways.
例えば、前記実施例では、スリーブ６に着磁され、駆動
ローラ５が磁性材料で構成されたが、これを逆にして駆
動ローラ５に着磁するとともにスリーブ６を磁性材料で
構成してもよい。For example, in the above embodiment, the sleeve 6 is magnetized and the drive roller 5 is made of a magnetic material, but this may be reversed so that the drive roller 5 is magnetized and the sleeve 6 is made of a magnetic material. .
以上説明したように本発明によると、駆動ローラに該ロ
ーラ外径より若干大きい内径を有する現像剤担持用スリ
ーブを外嵌し、該スリーブを一方側から前記駆動ローラ
に圧接して他方側にたるみ部分を形成しつつ該たるみ部
分を静電潜像担持体に接触させる現像装置において、ス
リーブが駆動ローラの回転に円滑に従動して回転し、ス
リーブと静電潜像担持体とのニップ幅がスリーブ回転軸
線方向にわたって実質上−様であり、それによって安定
した画像が得られる利点がある。As explained above, according to the present invention, a developer carrying sleeve having an inner diameter slightly larger than the outer diameter of the roller is fitted around the drive roller, and the sleeve is pressed against the drive roller from one side so that the sleeve sag on the other side. In a developing device that brings the slack portion into contact with the electrostatic latent image carrier while forming a portion, the sleeve rotates smoothly following the rotation of the drive roller, and the nip width between the sleeve and the electrostatic latent image carrier increases. There is an advantage that the sleeve is substantially uniform in the direction of the rotational axis of the sleeve, thereby providing a stable image.
第１図は本発明の一実施例の概略断面図、第２図から第
４図はそれぞれスリーブの着磁パターンの説明図、第５
図は第１図に示す実施例におけるスリーブと静電潜像担
持体とのニップ幅の説明図、第６図は従来例説明図、第
７図は第６図に示す従来例におけるスリーブと静電潜像
担持体とのニップ幅の説明図である。
５・・・駆動ローラ
６・・・スリーブ
６０・・・たるみ部分
ＰＣ・・・感光体ドラム
出 願 人 ミノルタカメラ株式会社
第
１
図
第
図
第
図
第
図
第
図
］ＷFIG. 1 is a schematic sectional view of one embodiment of the present invention, FIGS. 2 to 4 are explanatory diagrams of the magnetization pattern of the sleeve, and FIG.
The figure is an illustration of the nip width between the sleeve and the electrostatic latent image carrier in the embodiment shown in Fig. 1, Fig. 6 is an illustration of the conventional example, and Fig. 7 is an illustration of the nip width between the sleeve and the electrostatic latent image carrier in the embodiment shown in Fig. 6. FIG. 3 is an explanatory diagram of the nip width with the electrolatent image carrier. 5... Drive roller 6... Sleeve 60... Slack portion PC... Photosensitive drum Applicant Minolta Camera Co., Ltd.
Claims (1)
有する現像剤担持用スリーブを外嵌し、該スリーブを一
方側から前記駆動ローラに圧接して他方側にたるみ部分
を形成しつつ該たるみ部分を静電潜像担持体に接触させ
る現像装置において、前記駆動ローラおよび前記スリー
ブのうちいずれか一方に着磁するとともに他方の少なく
とも一部を該着磁部分により吸引力を受ける磁性材料で
形成したことを特徴とする現像装置。(1) A developer carrying sleeve having an inner diameter slightly larger than the outer diameter of the roller is fitted onto the drive roller, and the sleeve is pressed against the drive roller from one side to form a slack portion on the other side. In a developing device in which a portion is brought into contact with an electrostatic latent image carrier, one of the drive roller and the sleeve is magnetized, and at least a portion of the other is made of a magnetic material that receives an attractive force from the magnetized portion. A developing device characterized by:
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2050251A JPH03251879A (en) | 1990-03-01 | 1990-03-01 | Developing device |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2050251A JPH03251879A (en) | 1990-03-01 | 1990-03-01 | Developing device |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH03251879A true JPH03251879A (en) | 1991-11-11 |
Family
ID=12853763
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP2050251A Pending JPH03251879A (en) | 1990-03-01 | 1990-03-01 | Developing device |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH03251879A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP4669623B2 (en) * | 2001-03-27 | 2011-04-13 | 株式会社リコー | Magnetic roller, manufacturing method thereof, developing device and image forming apparatus |
-
1990
- 1990-03-01 JP JP2050251A patent/JPH03251879A/en active Pending
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP4669623B2 (en) * | 2001-03-27 | 2011-04-13 | 株式会社リコー | Magnetic roller, manufacturing method thereof, developing device and image forming apparatus |
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