JP3861980B2

JP3861980B2 - Charging device

Info

Publication number: JP3861980B2
Application number: JP2001112515A
Authority: JP
Inventors: 前田将宏
Original assignee: Seiko Epson Corp
Current assignee: Seiko Epson Corp
Priority date: 2001-04-11
Filing date: 2001-04-11
Publication date: 2006-12-27
Anticipated expiration: 2021-04-11
Also published as: JP2002311691A

Description

【０００１】
【発明の属する技術分野】
本発明は放電ワイヤとグリッドを有するコロナ帯電装置に関する。
【０００２】
【従来の技術】
画像形成装置に使用される帯電装置として、コロナ放電を利用したものが一般に広く用いられている。特に、感光体を帯電するためには、放電ワイヤと感光体表面の電位を制御するグリッドを備えたスコロトロンと呼ばれる装置が用いられている。この装置は画像形成を行うにつれて、放電ワイヤの劣化や付着物が付くことにより、画像が乱されることがあった。これを改善する手段として、ワイヤに清掃部材を接触させて摺動させることにより、クリーニングを行うものが提案されている（特公平４−６４０６６号公報）。また、グリッドとワイヤの両方とも清掃するものも提案されている（実開昭６３−２４５６１号公報）。
【０００３】
【発明が解決しようとする課題】
ところで、コロナ帯電装置は感光体の上方に配置し、帯電を行うことが一般的に行われている。これは浮遊トナー等が落下してコロナ帯電装置を汚染するのを防ぐためであった。その結果、コロナ放電によって発生するオゾンや窒素酸化物等、空気より重い生成物が、装置停止時などファンが停止している時に感光体表面近傍に滞留し、感光体層の劣化、画像の劣化を招く原因となっていた。これに対してコロナ帯電装置を感光体の下方に配置することより、感光層をオゾンや窒素酸化物から守ることが可能である。
【０００４】
しかし、コロナ帯電装置を感光体の下方に配置した場合、放電ワイヤがグリッドよりも下方に位置するため、放電ワイヤに清掃部材を接触させて、摺動するものにあってはカートリッジを取り外して清掃を終了し、カートリッジを装置に装着する時にグリッドに付着していたトナー等の異物がワイヤに落下し、清掃の効果が不充分になるという問題があった。
【０００５】
また、グリッド、ワイヤ両方とも清掃するものでは、帯電装置の配置方向、グリッド清掃部材とワイヤ清掃部材の位置関係が明確ではない。このため、例えばグリッドとワイヤを同時に清掃したのでは、グリッド清掃部材からワイヤへトナー等の異物が落下し、ワイヤの清掃効果が十分に得られず、帯電装置を感光体の下方に配置して帯電を行う場合に、清掃直後より画像不良が発生するという問題があった。
【０００６】
【課題を解決するための手段】
本発明は上記課題を解決するためのもので、感光体の下方から帯電を行う場合に、帯電装置の清掃効果を十分に高めて良好な画像が得られるようにするものである。
そのために本発明は、放電ワイヤとグリッドを有し、感光体の下方に配置されてコロナ帯電を行う帯電装置において、放電ワイヤに当接するワイヤ清掃部材およびグリッドに当接するグリッド清掃部材を有し、放電ワイヤおよびグリッドの張架方向に沿って摺動することにより清掃を行う清掃手段を備え、前記清掃手段は、グリッド清掃部材が固定され、ワイヤ清掃部材が回動可能に取り付けられる清掃部材支持部材を有し、前記清掃部材支持部材を放電ワイヤおよびグリッドの張架方向に沿って移動させることにより、前記清掃手段の摺動時進行方向においてグリッド清掃部材がワイヤ清掃部材よりも先行するようにして清掃を行うことを特徴とする。
また、本発明は、前記清掃手段は、放電ワイヤおよびグリッドの張架方向に沿う往復摺動の少なくとも復路においてグリッド清掃部材がワイヤ清掃部材よりも進行方向において先行するように構成されていることを特徴とする。
また、本発明は、ワイヤの清掃範囲とグリッド清掃範囲の共通部分を少なくとも有効画像範囲より広くしたことを特徴とする。
また、本発明は、グリッド清掃部材は、残留物がグリッド上に残らない材質からなることを特徴とする。
【０００７】
【発明の実施の形態】
以下、本発明の実施の形態を図面を参照しつつ説明する。
図１は本発明の帯電装置の清掃部材を説明する図、図２は帯電装置の清掃メカニズムを説明する図である。
本発明の帯電装置は、ケース８内に収納されて感光体１１の下方に配置され、清掃時にはケースの回転カバー１０を開いてカートリッジを取り外せるようになっている。回転カバー１０には、清掃部材つまみ７がその待機位置において嵌合する位置規制用開口部９が設けられている。一方、帯電装置のハウス１の底面は放電ワイヤとグリッドの張架方向に沿って開口しており、清掃部材つまみ７はその開口を通して清掃部材支持部材４に接続している。したがって、清掃部材つまみ７がその待機位置にある状態で、回転カバー１０を開くと、清掃部材つまみ７は手動で感光体軸方向に移動させることができる。清掃部材支持部材４にはグリッドに当接するグリッド清掃部材６、ワイヤ清掃部材５が取り付けられていて、清掃部材つまみ７を持って清掃部材支持部材４を放電ワイヤ、グリッドを清掃できる。なお、帯電装置により発生するオゾン等は矢印１２で示す排気方向に、清掃部材つまみ待機位置規制用開口部９とは反対側に排気ポンプ（図示せず）を設けて排気しており、開口部９から浮遊トナー等が入り込みにくくしている。
【０００８】
図２に示す例では、グリッド３は感光体軸方向に延びる長方形のプレートに斜め方向に多数の孔を開けた構成のもので、その下方にワイヤ２が張られている。本発明の清掃手段は、清掃部材支持部材４にグリッド３の下面に当接するグリッド清掃部材６と、ワイヤ２を両側から挟むワイヤ清掃部材５が取り付けられている。上記したように、清掃部材支持部材４には清掃部材つまみ７が取り付けられており、清掃部材つまみ７は帯電装置のハウス１の底面に軸方向に沿って形成された開口を通してケース８外に延びており、清掃部材つまみ７を掴んでこれを感光体軸方向に往復動することにより、グリッドとワイヤの清掃が行われる。
【０００９】
グリッド清掃部材６は清掃部材支持部材４に固定され、一方、ワイヤ清掃部材５は清掃部材支持部材４に対して回動可能に取り付けられているので、清掃部材つまみ７を持ってワイヤ張架方向に沿って往復動させた時、ワイヤ２との摩擦によりワイヤ清掃部材５はグリッド清掃部材６に対して遅れを生ずる。そのため、グリッド清掃部材がワイヤ清掃部材より先行し、グリッド清掃部材によりグリッドから異物がワイヤ側に落下しても後から到達するワイヤ清掃部材によってその汚れは取り除かれる。
【００１０】
このように、清掃部材の進行方向においてグリッド清掃部材がワイヤ清掃部材よりも常に先行するようにしたので、グリッド清掃によりワイヤへ落下した異物を取り除くことができ、この場合、感光体往路においてグリッド清掃によりワイヤへ落下した異物をワイヤ清掃部材により十分に取り除くことができない場合にも、復路のワイヤ清掃により取り除くことが可能であり、より清掃効果を高めることが可能である。
【００１１】
また、ワイヤとグリッドの清掃部材の両方とも有効画像幅に対してこれよりも広い範囲を清掃できるように移動範囲を設定する。これにより、有効画像幅に対してワイヤ、グリッド両方とも清掃を行うことが可能である。
【００１２】
また、グリッドにフェルトやブラシ等の毛が残留すると異常放電が発生して画像を乱す場合がある。そこで、グリッド清掃部材には抜け毛等残留物がグリッド上に残らない部材、例えば合成皮革等を用いるようにする。これにより異常放電を防ぐことが可能である。
【００１３】
【発明の効果】
以上のように本発明によれば、清掃部材の進行方向において、グリッド清掃部材がワイヤ清掃部材よりも先行するようにしたので、グリッド清掃によりワイヤへ落下した異物を後から到達するワイヤ清掃部材で取り除くことができる。また、往路において十分ワイヤへの落下物を取り除くことができない場合であっても、復路のワイヤ清掃によりこれを取り除くことができ、より清掃効果を多高めて良好な画像を得ることができる。また、有効画像幅に対してワイヤとグリッドの清掃部材の移動範囲を広く設定することにより、有効画像幅の清掃を行うことができ同様に良好な画像が得られる。また、グリッド清掃部材には残留物がグリッド上に残らない部材を用いることで異常放電を防ぎ、良好な画像が得られる。
【図面の簡単な説明】
【図１】本発明の画像形成装置に用いられる帯電装置の清掃部材を説明する図である。
【図２】帯電装置の清掃メカニズムを説明する図である。
【符号の説明】
１…ハウス、２…ワイヤ、３…グリッド、４…清掃部材支持部材、５…ワイヤ清掃部材、６…グリッド清掃部材、７…清掃部材つまみ、８…ケース、９…清掃部材つまみ待機位置規制用開口部、１０…回転カバー、１１…感光体。[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a corona charging device having a discharge wire and a grid.
[0002]
[Prior art]
As a charging device used in an image forming apparatus, those using corona discharge are generally widely used. In particular, in order to charge the photoconductor, an apparatus called a scorotron having a discharge wire and a grid for controlling the potential of the photoconductor surface is used. In this apparatus, as the image is formed, the image may be disturbed due to the deterioration of the discharge wire or the adhering matter. As means for improving this, there has been proposed a method in which cleaning is performed by bringing a cleaning member into contact with a wire and sliding the wire (Japanese Patent Publication No. 4-64066). In addition, it has been proposed to clean both the grid and the wire (Japanese Utility Model Publication No. 63-24561).
[0003]
[Problems to be solved by the invention]
By the way, it is generally performed that the corona charging device is disposed above the photosensitive member and is charged. This is to prevent floating toner or the like from falling and contaminating the corona charging device. As a result, products that are heavier than air, such as ozone and nitrogen oxides generated by corona discharge, stay near the surface of the photoconductor when the fan is stopped, such as when the device is stopped. Was the cause. On the other hand, it is possible to protect the photosensitive layer from ozone and nitrogen oxide by disposing the corona charging device below the photosensitive member.
[0004]
However, when the corona charging device is placed below the photoconductor, the discharge wire is positioned below the grid, so the cleaning member is in contact with the discharge wire, and if it slides, remove the cartridge and clean it. When the cartridge is installed in the apparatus, foreign matters such as toner adhered to the grid fall on the wire, and the cleaning effect becomes insufficient.
[0005]
Further, when both the grid and the wire are cleaned, the arrangement direction of the charging device and the positional relationship between the grid cleaning member and the wire cleaning member are not clear. For this reason, for example, if the grid and the wire are cleaned at the same time, foreign matters such as toner fall from the grid cleaning member to the wire, and the wire cleaning effect cannot be sufficiently obtained. When charging is performed, there is a problem that an image defect occurs immediately after cleaning.
[0006]
[Means for Solving the Problems]
SUMMARY OF THE INVENTION The present invention is to solve the above-mentioned problems, and is intended to obtain a good image by sufficiently enhancing the cleaning effect of the charging device when charging is performed from below the photoreceptor.
Therefore, the present invention has a discharge wire and a grid, and a charging device that is disposed below the photoreceptor and performs corona charging, has a wire cleaning member that contacts the discharge wire and a grid cleaning member that contacts the grid, A cleaning member support member provided with cleaning means for cleaning by sliding along the extending direction of the discharge wire and the grid, the cleaning means being fixed to the grid cleaning member and rotatably attached to the wire cleaning member And moving the cleaning member support member along the stretching direction of the discharge wire and the grid so that the grid cleaning member precedes the wire cleaning member in the sliding direction of the cleaning means. It is characterized by cleaning.
Further, in the present invention, the cleaning means is configured such that the grid cleaning member precedes the wire cleaning member in the traveling direction at least in the return path of the reciprocating sliding along the stretching direction of the discharge wire and the grid. Features.
Further, the present invention is characterized in that the common part of the wire cleaning range and the grid cleaning range is at least wider than the effective image range.
Further, the present invention is characterized in that the grid cleaning member is made of a material that does not leave a residue on the grid.
[0007]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a diagram illustrating a cleaning member of a charging device according to the present invention, and FIG. 2 is a diagram illustrating a cleaning mechanism of the charging device.
The charging device of the present invention is housed in the case 8 and disposed below the photosensitive member 11, and the cartridge can be removed by opening the rotating cover 10 of the case during cleaning. The rotary cover 10 is provided with a position restricting opening 9 into which the cleaning member knob 7 is fitted at the standby position. On the other hand, the bottom surface of the house 1 of the charging device is opened along the extending direction of the discharge wire and the grid, and the cleaning member knob 7 is connected to the cleaning member support member 4 through the opening. Therefore, when the rotary cover 10 is opened while the cleaning member knob 7 is in its standby position, the cleaning member knob 7 can be manually moved in the direction of the photosensitive member axis. The cleaning member support member 4 is provided with a grid cleaning member 6 and a wire cleaning member 5 that come into contact with the grid, and the cleaning member support member 4 can be cleaned with the discharge wire and the grid by holding the cleaning member knob 7. The ozone generated by the charging device is exhausted in the exhaust direction indicated by the arrow 12 by providing an exhaust pump (not shown) on the side opposite to the cleaning member knob standby position restricting opening 9. 9 makes it difficult for floating toner or the like to enter.
[0008]
In the example shown in FIG. 2, the grid 3 has a configuration in which a large number of holes are opened obliquely in a rectangular plate extending in the direction of the photoreceptor axis, and a wire 2 is stretched below the grid 3. In the cleaning means of the present invention, a grid cleaning member 6 that contacts the lower surface of the grid 3 and a wire cleaning member 5 that sandwiches the wire 2 from both sides are attached to the cleaning member support member 4. As described above, the cleaning member knob 7 is attached to the cleaning member support member 4, and the cleaning member knob 7 extends out of the case 8 through an opening formed along the axial direction on the bottom surface of the house 1 of the charging device. The grid and wires are cleaned by gripping the cleaning member knob 7 and reciprocating it in the photosensitive member axial direction.
[0009]
The grid cleaning member 6 is fixed to the cleaning member support member 4, while the wire cleaning member 5 is rotatably attached to the cleaning member support member 4, so that the wire cleaning direction is held with the cleaning member knob 7. When the wire cleaning member 5 is reciprocated along the wire 2, the wire cleaning member 5 is delayed with respect to the grid cleaning member 6 due to friction with the wire 2. For this reason, the grid cleaning member precedes the wire cleaning member, and even if foreign matter falls from the grid to the wire side by the grid cleaning member, the dirt is removed by the wire cleaning member that arrives later.
[0010]
As described above, since the grid cleaning member always precedes the wire cleaning member in the moving direction of the cleaning member, foreign matters dropped on the wire by the grid cleaning can be removed. In this case, the grid cleaning is performed in the forward path of the photosensitive member. Even when the foreign matter dropped on the wire cannot be sufficiently removed by the wire cleaning member, it can be removed by wire cleaning in the return path, and the cleaning effect can be further enhanced.
[0011]
Further, the moving range is set so that both the wire and the grid cleaning member can clean a wider range than the effective image width. Thereby, both the wire and the grid can be cleaned with respect to the effective image width.
[0012]
Further, if hair such as felt or brush remains on the grid, abnormal discharge may occur and the image may be disturbed. Therefore, a member that does not leave any residue such as hair loss on the grid, such as synthetic leather, is used for the grid cleaning member. As a result, abnormal discharge can be prevented.
[0013]
【The invention's effect】
As described above, according to the present invention, the grid cleaning member precedes the wire cleaning member in the traveling direction of the cleaning member. Can be removed. Further, even when the falling object cannot be sufficiently removed in the forward path, it can be removed by cleaning the wire in the backward path, and a good image can be obtained with more enhanced cleaning effects. Further, by setting the movement range of the wire and grid cleaning members wider than the effective image width, the effective image width can be cleaned, and similarly good images can be obtained. Further, by using a member that does not leave any residue on the grid as the grid cleaning member, abnormal discharge can be prevented and a good image can be obtained.
[Brief description of the drawings]
FIG. 1 is a diagram illustrating a cleaning member of a charging device used in an image forming apparatus of the present invention.
FIG. 2 is a diagram illustrating a cleaning mechanism of the charging device.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... House, 2 ... Wire, 3 ... Grid, 4 ... Cleaning member support member, 5 ... Wire cleaning member, 6 ... Grid cleaning member, 7 ... Cleaning member knob, 8 ... Case, 9 ... Cleaning member knob standby position regulation Opening, 10 ... rotating cover, 11 ... photoconductor.

Claims

A charging device that includes a discharge wire and a grid, and is disposed below the photosensitive member and performs corona charging, includes a wire cleaning member that contacts the discharge wire and a grid cleaning member that contacts the grid, and the tension of the discharge wire and the grid. The cleaning unit includes a cleaning unit that performs cleaning by sliding along a racking direction. The cleaning unit includes a cleaning member support member to which a grid cleaning member is fixed and a wire cleaning member is rotatably attached. by moving the support member discharge wire and along the stretched direction of the grid, characterized in that for cleaning cleaning brush in the sliding time of the traveling direction of said cleaning means so as to precede the wire cleaning member The charging device.

The cleaning means is configured such that the grid cleaning member precedes the wire cleaning member in the advancing direction at least in the return path of reciprocating sliding along the extending direction of the discharge wire and the grid. The charging device described.

3. The charging device according to claim 1, wherein a common portion of the wire cleaning range and the grid cleaning range is at least wider than the effective image range.

3. The charging device according to claim 1, wherein the grid cleaning member is made of a material that does not leave a residue on the grid.