JP4283688B2 - Developing device for electrophotographic apparatus - Google Patents

Developing device for electrophotographic apparatus Download PDF

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JP4283688B2
JP4283688B2 JP2004009071A JP2004009071A JP4283688B2 JP 4283688 B2 JP4283688 B2 JP 4283688B2 JP 2004009071 A JP2004009071 A JP 2004009071A JP 2004009071 A JP2004009071 A JP 2004009071A JP 4283688 B2 JP4283688 B2 JP 4283688B2
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developer
developing
magnetic roll
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plate
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JP2005202203A (en
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宏 白田
浩 上野
公太郎 山田
聡 藤田
進一 渡辺
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Ricoh Co Ltd
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Description

本発明は、電子写真装置の現像装置に関するものである。   The present invention relates to a developing device for an electrophotographic apparatus.

プリンタ等に利用される電子写真装置の現像装置では現像で消費され不均一となった現像剤のトナー濃度を均一化するための撹拌装置として安価で駆動力を必要としないクロスミキシング構造の撹拌装置（以下、クロスミキサという）が広く用いられている。   An agitation device having a cross-mixing structure that is inexpensive and does not require a driving force as an agitation device for uniformizing the toner density of a developer that has been consumed in development and becomes non-uniform in a developing device of an electrophotographic apparatus used in a printer or the like (Hereinafter referred to as a cross mixer) is widely used.

従来のクロスミキサを備えた現像装置を、図４〜図６を用いて具体的に説明する。   A developing device equipped with a conventional cross mixer will be specifically described with reference to FIGS.

図４は断面図、図５はクロスミキサでの現像剤撹拌状態を示す斜視図、図６は図５のＡ方向から見た現像剤搬送状態を示す断面図である。   4 is a cross-sectional view, FIG. 5 is a perspective view showing a developer stirring state in a cross mixer, and FIG. 6 is a cross-sectional view showing a developer conveying state as seen from the direction A in FIG.

図において、現像容器１内部には搬送磁気ロール２及び感光体３に対向して現像磁気ロール４、現像磁気ロ−ル５が取り付けられており、モータ等の適当な動力により図の矢印方向にほぼ同周速で回転する。現像磁気ロール４、現像磁気ロール５に適当な間隔で対向してドクター板６が、現像磁気ロール５に対向して分離板８ｃの両側に複数の偏向板８ａ、８ｂを有するクロスミキサ８が、現像磁気ロール４に対向して同様の構成のクロスミキサ７がそれぞれ取り付けられている。クロスミキサ８の下方にはトナー補給点に現像剤を導くガイド板９とガイド板９に対向して直線型現像剤規制板１０が取り付けられている。又、搬送磁気ロール２に隣接して撹拌パドル１１が取り付けられており、現像磁気ロール４、現像磁気ロール５及び搬送磁気ロール２と連動して適当な動力により図の矢印方向に回転する。さらに撹拌パドル１１下部の現像容器１にはトナー濃度センサ１２が取り付けられている。一方、現像容器１に隣接して設けられたトナー容器１３の下部にはトナー補給ロール１４が取り付けられており、適当な動力で駆動される。   In the drawing, a developing magnetic roll 4 and a developing magnetic roll 5 are attached to the inside of the developing container 1 so as to face the transport magnetic roll 2 and the photoconductor 3, and in the direction of the arrow in the figure by appropriate power such as a motor. It rotates at almost the same peripheral speed. A cross mixer 8 having a plurality of deflecting plates 8a and 8b on both sides of the separating plate 8c facing the developing magnetic roll 5 and the developing magnetic roll 5 with a doctor plate 6 facing the developing magnetic roll 5 on both sides, Opposite to the developing magnetic roll 4, cross mixers 7 having the same configuration are respectively attached. Below the cross mixer 8, a guide plate 9 for guiding the developer to the toner replenishment point and a linear developer regulating plate 10 are attached so as to face the guide plate 9. An agitation paddle 11 is attached adjacent to the transport magnetic roll 2 and rotates in the direction of the arrow in the figure by appropriate power in conjunction with the development magnetic roll 4, the development magnetic roll 5 and the transport magnetic roll 2. Further, a toner concentration sensor 12 is attached to the developing container 1 below the stirring paddle 11. On the other hand, a toner replenishing roll 14 is attached to the lower part of the toner container 13 provided adjacent to the developing container 1, and is driven with appropriate power.

前記現像装置において、現像容器１内部の現像剤１５は搬送磁気ロール２の回転により搬送され現像磁気ロール４、現像磁気ロール５に受け渡され、ドクター板６で適当な厚みに規制され、現像磁気ロール４、現像磁気ロール５の上面を搬送され感光体３に送られる。   In the developing device, the developer 15 in the developing container 1 is conveyed by the rotation of the conveying magnetic roll 2 and is transferred to the developing magnetic roll 4 and the developing magnetic roll 5, and is regulated to an appropriate thickness by the doctor plate 6. The upper surfaces of the roll 4 and the developing magnetic roll 5 are conveyed and sent to the photoreceptor 3.

感光体３に接触し現像を終えた現像磁気ロール５側の現像剤１５ｂはクロスミキサ８に落下し、複数の偏向板８ａ、８ｂで軸方向に搬送、撹拌されることで現像によって不均一になったトナー濃度が均一化された後、直線型現像剤規制板１０により現像剤厚みが規制され、ガイド板９によりトナー補給ロール１４下を通り撹拌パドル１１で送られ、トナー濃度センサ１２でトナー濃度の測定がなされ、再び搬送磁気ロール２に送られる。   The developer 15b on the side of the developing magnetic roll 5 that has contacted the photoconductor 3 and completed the development falls to the cross mixer 8, and is transported and agitated in the axial direction by the plurality of deflecting plates 8a and 8b so that it becomes uneven due to development. After the toner density is uniformized, the developer thickness is regulated by the linear developer regulating plate 10, and is fed by the guide pad 9 through the toner supply roll 14 by the stirring paddle 11. The concentration is measured and sent to the transport magnetic roll 2 again.

又、上記現像プロセスが行われる内に現像剤中のトナーが消費されトナー濃度が低下し、トナー濃度センサ１２で測定されたトナー濃度がある一定レベルを下回ると、トナー補給ロール１４が駆動されトナー容器１３内のトナー１６が現像剤１５ｂに補給される。一方、現像磁気ロール４側の現像剤１５ａはクロスミキサ７に落下し、前記と同様に搬送、撹拌された後、クロスミキサ７から落下して現像剤１５と合流し再び搬送磁気ロール２に送られる。   Further, when the toner in the developer is consumed while the developing process is performed and the toner density is lowered, and the toner density measured by the toner density sensor 12 falls below a certain level, the toner supply roll 14 is driven and the toner is driven. The toner 16 in the container 13 is supplied to the developer 15b. On the other hand, the developer 15a on the side of the developing magnetic roll 4 falls to the cross mixer 7 and is transported and agitated in the same manner as described above, and then drops from the cross mixer 7 and joins with the developer 15 and is sent to the transport magnetic roll 2 again. It is done.

前記現像装置において、ドクター板６で均一な厚みに規制された現像剤１５ｂは、現像終了後、現像磁気ロール５からクロスミキサ８に落下し、複数の偏向板８ａ、８ｂにより軸方向に搬送、撹拌される。しかしながら、現像剤１５ｂはそれぞれの偏向板により分割されて集められるため、クロスミキサ８から落下した時、偏向板の間隔で図のαの部分はく、βの部分は低いそれぞれ一定高さの凹凸で、軸方向の搬送厚が不均一なスジ状の流れとなり、トナー濃度センサ１２がトナー濃度の低下を検出し、トナー補給ロール１４によりトナー容器１３からトナー１６が現像剤１５ｂに補給されると、現像剤が多いαの部分はトナー濃度が薄く、現像剤が少ないβの部分はトナー濃度が濃くなり、スジ状の印刷濃度ムラとなって現れる。又、不均一なトナー濃度により、トナー濃度センサ１２で正確なトナー濃度の検出が出来なくなるため、過剰な又は過小なトナー補給が行われ、印刷濃度が全体的に濃く又は薄くなる等の不具合が発生する。   In the developing device, the developer 15b regulated to have a uniform thickness by the doctor plate 6 falls from the developing magnetic roll 5 to the cross mixer 8 after the development, and is conveyed in the axial direction by the plurality of deflecting plates 8a and 8b. Stir. However, since the developer 15b is divided and collected by the respective deflecting plates, when falling from the cross mixer 8, the portion of α in the figure is not spaced by the spacing of the deflecting plates, and the portion of β is low and uneven with a certain height. When the toner density sensor 12 detects a decrease in toner density and the toner replenishing roll 14 replenishes the toner 16 from the toner container 13 to the developer 15b. The α portion where the developer is large has a low toner density, and the β portion where the developer is small has a high toner density, resulting in streaky print density unevenness. Further, since the toner density sensor 12 cannot accurately detect the toner density due to the non-uniform toner density, excessive or insufficient toner replenishment is performed, and there is a problem that the printing density becomes dark or thin as a whole. appear.

そこで従来、クロスミキサ８から落下した現像剤１５ｂの厚みを均一化する方法として、クロスミキサ８とトナー補給点の間に、ガイド板９と適当な間隔で対向する直線型現剤規制板１０を設ける方法を取っていたが、ガイド板９と直線型現像剤規制板１０との間隔を設定する条件が難しく、わずかでも間隔が広いと凹凸のまま現像剤１５ｂがすり抜けていき、前述と同様にスジ状の印刷濃度ムラとなり、狭いとクロスミキサ８上方から現像剤があふれ、現像磁気ロール５の回転ロックを引き起こし、クロスミキサ８とガイド板９の隙間部分から凹凸のスジ状のまま現像剤が流出し、前述と同様のスジ状の印刷濃度ムラとなる等の不具合を生じ、現像剤規制部分への現像剤の流入量に自在に対応できず、前記間隔と現像剤の流入量が一致する時しかバランスがとれないと言った問題があった。   Therefore, conventionally, as a method for equalizing the thickness of the developer 15b dropped from the cross mixer 8, a linear type active material regulating plate 10 facing the guide plate 9 at an appropriate interval is provided between the cross mixer 8 and the toner supply point. However, the condition for setting the distance between the guide plate 9 and the linear developer regulating plate 10 is difficult, and even if the distance is wide, the developer 15b slips through the concave and convex portions, as described above. If it is narrow, the developer overflows from above the cross mixer 8 and causes the rotation of the developing magnetic roll 5, and the developer remains in the form of uneven stripes from the gap between the cross mixer 8 and the guide plate 9. This causes problems such as streaky print density unevenness similar to the above, and it is not possible to respond freely to the amount of developer flowing into the developer restricting portion, and the interval and the amount of developer flowing match. There has been a problem that only said that the balance can not be taken.

また、クロスミキサ８から落下した現像剤１５ｂの厚みを均一化する方法として、図７に示すように、櫛歯上の櫛形現像剤規制板１８をクロスミキサ８とトナー補給点の間に設けたものがあるが、軸方向に凹凸の流れの現像剤１５ｂが櫛形現像剤規制板１８を通過するとき、流れが凸の部分のみが規制板に当たり搬送厚を規制するが、前記凸部の現像剤が凹部に回り込み、凹部が凸となり、結果として軸方向の現像剤凹凸は緩和されるものの、軸方向に均一な現像剤の流れを得るに至らなかった。   Further, as a method for equalizing the thickness of the developer 15b dropped from the cross mixer 8, a comb-shaped developer regulating plate 18 on the comb teeth is provided between the cross mixer 8 and the toner replenishment point as shown in FIG. Although the developer 15b having a concavo-convex flow in the axial direction passes through the comb-shaped developer regulating plate 18, only the convex portion of the flow hits the regulating plate and regulates the transport thickness. Around the concave portion, and the concave portion becomes convex. As a result, the unevenness of the developer in the axial direction is reduced, but a uniform developer flow in the axial direction cannot be obtained.

特開平１１−１４３１９１号公報JP-A-11-143191

上記したように、従来の現像装置にあっては、クロスミキサの出口において現像剤は軸方向に凹凸が発生し、この凹凸により磁気ロ−ル上の現像剤量が軸方向に不均一となり、印刷出力に軸方向の濃淡差が発生するという問題があった。   As described above, in the conventional developing device, the developer is uneven in the axial direction at the exit of the cross mixer, and this unevenness causes the amount of developer on the magnetic roll to be uneven in the axial direction. There has been a problem that a shading difference in the axial direction occurs in the print output.

本発明は、クロスミキサにより発生する現像剤の軸方向の凹凸な流れを均一化し、印刷濃度ムラの発生し難い現像装置を提供することを目的とする。   An object of the present invention is to provide a developing device in which uneven flow in the axial direction of a developer generated by a cross mixer is made uniform and print density unevenness is hardly generated.

上記目的は、現像剤の流れ方向にフレキシブルで且つ現像剤の流れ量によって現像剤の流れ口の広さが可変である可撓型現像剤規制板を設けることによって達成される。   The above object can be achieved by providing a flexible developer regulating plate that is flexible in the developer flow direction and has a developer flow port whose width is variable depending on the developer flow amount.

本発明によれば、クロスミキサにより発生する現像剤の軸方向の凹凸な流れを均一化し、印刷濃度ムラの発生し難い現像装置を提供できる。   According to the present invention, it is possible to provide a developing device in which the uneven flow in the axial direction of the developer generated by the cross mixer is made uniform and print density unevenness hardly occurs.

以下、本発明の実施例を図１〜図３を用いて詳細に説明する。図１〜図３において、図４〜図6と同一部分は同一符号で示し、詳細な説明は省略する。   Hereinafter, embodiments of the present invention will be described in detail with reference to FIGS. 1 to 3, the same parts as those in FIGS. 4 to 6 are denoted by the same reference numerals, and detailed description thereof is omitted.

図１は本発明による現像装置の一実施例を示す断面図、図２はクロスミキサでの現像剤撹拌状態を示す斜視図、図３は図２のＡ方向から見た現像剤搬送状態を示す断面図である。   1 is a cross-sectional view showing an embodiment of a developing device according to the present invention, FIG. 2 is a perspective view showing a developer stirring state in a cross mixer, and FIG. 3 shows a developer conveying state as seen from the direction A in FIG. It is sectional drawing.

本発明は、クロスミキサ８下方にフィルム材からなる、現像剤の流れ方向にフレキシブルな直線型現像剤規制板１７を設けたことを特徴とするものである。   The present invention is characterized in that a linear developer regulating plate 17 made of a film material and flexible in the flow direction of the developer is provided below the cross mixer 8.

クロスミキサ８から落下した軸方向に凹凸の現像材１５ｂの流れは、凸部と凹部の両方で、現像剤の流れ方向にフレキシブルな直線型現像剤規制板１７に当る。現像剤１５ｂの流れが当るとフレキシブルな直線型現像剤規制板１７は流れ方向に撓ながら、現像剤１５ｂの流れの厚みを押さえ、ほぼ軸方向に均一な現像剤１５ｂの流れが得られる。現像剤１５ｂの凸部においては現像剤の凹部に比べフレキシブルな直線型現像剤規制板は大きく撓み、また、現像剤１５ｂの流れ量が多くなるとフレキシブルな直線型現像剤規制板１７の撓み量は、現像剤１５ｂの流れ量に追従し大きくなるので、現像剤１５ｂを滞留させることがなく、クロスミキサ８上方から現像剤があふれない。   The flow of the concavo-convex developer 15b dropped from the cross mixer 8 hits the linear developer regulating plate 17 that is flexible in the developer flow direction in both the convex and concave portions. When the flow of the developer 15b hits, the flexible linear developer regulating plate 17 is bent in the flow direction, while suppressing the thickness of the flow of the developer 15b, so that the flow of the developer 15b is almost uniform in the axial direction. In the convex portion of the developer 15b, the flexible linear developer regulating plate is greatly bent as compared with the concave portion of the developer, and when the flow amount of the developer 15b is increased, the deflection amount of the flexible linear developer regulating plate 17 is Since the flow increases with the flow amount of the developer 15b, the developer 15b is not retained and the developer does not overflow from above the cross mixer 8.

本発明による現像装置の一実施例を示す断面図。1 is a cross-sectional view showing an embodiment of a developing device according to the present invention. 本発明による現像装置の一実施例におけるクロスミキサでの現像剤撹拌状態を示す斜視図。FIG. 3 is a perspective view showing a developer stirring state in a cross mixer in an embodiment of the developing device according to the present invention. 図２のＡ方向から見た現像剤搬送状態を示す断面図。Sectional drawing which shows the developer conveyance state seen from the A direction of FIG. 従来技術における現像装置の構成を示す断面図。Sectional drawing which shows the structure of the developing device in a prior art. 従来技術における現像装置のクロスミキサでの現像剤撹拌状態を示す斜視図。The perspective view which shows the developing agent stirring state in the cross mixer of the developing device in a prior art. 図５のＡ方向から見た現像剤搬送状態を示す断面図。Sectional drawing which shows the developer conveyance state seen from the A direction of FIG. 従来の櫛形現像剤規制板での現像剤搬送状態を示す断面図。Sectional drawing which shows the developer conveyance state in the conventional comb-shaped developer control board.

符号の説明Explanation of symbols

１は現像容器、２は搬送磁気ロール、３は感光体、４は現像磁気ロール、５は現像磁気ロール、６はドクター板、７はクロスミキサ、８はクロスミキサ、９はガイド板、１０は直線型現像剤規制板、１１は撹拌パドル、１２はトナー濃度センサ、１３はトナー容器、１４はトナー補給ロール、１５は現像剤、１６はトナー、１７は可撓型現像剤規制板、１８は櫛形現像剤規制板である。
1 is a developing container, 2 is a conveying magnetic roll, 3 is a photoreceptor, 4 is a developing magnetic roll, 5 is a developing magnetic roll, 6 is a doctor plate, 7 is a cross mixer, 8 is a cross mixer, 9 is a guide plate, Linear developer regulating plate, 11 agitation paddle, 12 toner density sensor, 13 toner container, 14 toner supply roll, 15 developer, 16 toner, 17 flexible developer regulating plate, 18 This is a comb-shaped developer regulating plate.

Claims (1)

感光体に対向して配置した少なくとも一本の現像磁気ロールを有し、現像後の現像剤が前記現像磁気ロールから落下する位置に、前記現像剤を軸方向手前側に搬送する偏向板と奥側に搬送する偏向板が分離板の両側に等間隔で交互に配置されたクロスミキシング構造の撹拌装置を少なくとも一つ有し、トナー補給点側の前記撹拌装置下部に、該撹拌装置下部から落下する前記現像剤をトナー補給点に搬送するガイド板を有する電子写真装置の現像装置において、現像剤の流れ方向にフレキシブルで且つ現像剤の流れ量によって現像剤の流れ口の広さが可変である可撓型現像剤規制板を設けたことを特徴とする現像装置。
A deflection plate having at least one developing magnetic roll disposed so as to face the photoconductor, and a developer plate for conveying the developer to the front side in the axial direction at a position where the developed developer falls from the developing magnetic roll At least one cross-mixing stirrer in which deflecting plates conveyed to the side are alternately arranged at equal intervals on both sides of the separation plate, and fall from the lower part of the stirrer to the lower part of the stirrer on the toner replenishment point side In a developing device of an electrophotographic apparatus having a guide plate for transporting the developer to a toner replenishment point, the developer flow direction is flexible in the developer flow direction and the width of the developer flow port is variable depending on the developer flow amount. A developing device comprising a flexible developer regulating plate.
JP2004009071A 2004-01-16 2004-01-16 Developing device for electrophotographic apparatus Expired - Fee Related JP4283688B2 (en)

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Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US8718498B2 (en) 2010-03-17 2014-05-06 Ricoh Company, Limited Image forming apparatus and image forming method for advanced control of image density

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US8718498B2 (en) 2010-03-17 2014-05-06 Ricoh Company, Limited Image forming apparatus and image forming method for advanced control of image density

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