JP3652082B2

JP3652082B2 - Toner recovery apparatus, image forming unit, and image forming apparatus

Info

Publication number: JP3652082B2
Application number: JP26494597A
Authority: JP
Inventors: 岳郎榑沼
Original assignee: Ricoh Co Ltd
Current assignee: Ricoh Co Ltd
Priority date: 1997-09-11
Filing date: 1997-09-11
Publication date: 2005-05-25
Anticipated expiration: 2017-09-11
Also published as: JPH1184974A

Description

【０００１】
【発明の属する技術分野】
本発明はトナー回収装置の改良に関し、詳細には感光体等から除去されて回収スクリューにより回収されたトナーを搬送ベルトを用いて現像装置等に搬送するトナー回収装置において、大量のトナーが搬送ベルトへ移送されることにより発生する不具合や、トナーが搬送ベルトとプーリとの間に入り込むことにより発生する不具合を解決することができるトナー回収装置に関する。
【０００２】
【従来の技術】
電子写真式の画像形成装置においては、感光体上に形成したトナー像を転写紙上に転写してから定着することにより画像形成が行われる。トナーリサイクル機構を備えた画像形成装置においては、転写後に感光体や中間転写ベルト等の上に残留するトナーは、クリーニングブレード等のクリーニング手段によって掻き取られてから回収スクリュー、搬送ベルトを介して現像装置に搬送されて再使用に供される。また、回収トナーを回収容器に回収することも行われている。
図１０は実開平５−８１８６３号公報に開示された残留トナー回収装置の構成説明図であり、感光体等の上から回収したトナーを搬送する回収スクリュー１０１と、回収スクリュー１０１により搬送されてきたトナーを回収容器或は現像手段１０３に向けて搬送する無端状の搬送ベルト１０２と、を備えている。また、搬送ベルト１０２の面には係合孔１０２ａを所定のピッチで設けると共に、搬送ベルトを張設するプーリ周面の係合突起に該係合孔を係合させることにより、ベルトの滑りを防止するようにしている。
また、図１１は実開平３−２９９７１号公報に開示されたトナー回収装置を構成する搬送ベルトの構成説明図であり、プーリ１１０、１１１によってエンドレスに張設された搬送ベルト１１２の周面には所定のピッチで羽根１１３が設けられている。羽根１１３は、筐体１１５の内底面及び側壁の一部に、その先端部で摺接可能な構成を有している為、筐体底部に入り込んだトナーを速やかに回収し、トナーの残留、固形化を防止できる。
しかし、従来のトナー回収装置にあっては、図１０に示す様に回収スクリュー１０１の終端部に位置するフィン１０１ａ或は羽根１０１ｂが、搬送ベルト１０２に近接配置されているため、回収スクリュー１１０によって一挙に大量のトナーが搬送されてきた場合に、搬送ベルト自体の端面や羽根１１３の端面に大量のトナーがぶつかって円滑にトナーの移送が行われず、その結果この部分に一時的に滞留するトナーが回収スクリューや搬送ベルトの駆動に対する負荷となり、搬送性の低下を招いている。
【０００３】
なお、大量のトナーが一挙に搬送されてくる場合とは、例えば用紙ジャムによって転写が行われなかったことによって、感光体上に黒ベタ画像が残留した時に発生するものであり、この画像をクリーニングすると、大量のトナーが回収スクリューによって搬送されることとなる。通常の回収トナー量はさほど多くない為、回収スクリューや搬送ベルトの搬送能力は、回収トナーが少量である場合に合わせて設定してあるが、上記理由により大量のトナーが回収される場合には、搬送能力が間に合わずに搬送性の低下、負荷の増大を招く結果となる。
また、図１１に示す様に回収トナーＴを搬送ベルト１１２により現像室側に搬送する場合、搬送できなかった回収トナーは再度回収スクリュー（駆動側）側に搬送ベルトに乗って送り戻される。この時搬送ベルトの駆動用穴（図１０の係合孔１０２ａに相当）から搬送ベルト内周面に落下し従動コロと搬送ベルトに挟まれる可能性がある。この状態で搬送ベルトを継続使用すると、挟まれたトナーが凝集され、その後、剥れて現像装置内にトナー塊として供給されると異常画像を発生させる原因となる。
【０００４】
【発明が解決しようとする課題】
本発明は上記に鑑みてなされたものであり、感光体等に残留したトナーをクリーニング手段によって除去してから、回収スクリュー、搬送ベルトを経て現像装置、或は回収容器等に回収するようにした画像形成装置において、大量の回収トナーが回収スクリュー端部から搬送ベルト側に落下する時、回収スクリューのフィン部の終端部から搬送ベルトに対するトナーの移送能力が低過ぎることに起因して発生する、大量の回収トナーによる搬送性の低下を防止することを目的としている。
また、回収トナーを搬送ベルトにより現像室側に搬送する場合に、搬送ベルトの駆動用穴から搬送ベルト内周面に回収トナーが落下し、プーリと搬送ベルトに挟まれることに起因して形成された凝集トナーが剥がれて現像室に送られることにより異常画像が発生することを防止することを目的としている。
【０００５】
【課題を解決するための手段】
上記目的を達成する為、請求項１の発明は、回収したトナーを軸方向へ搬送する回収スクリューと、該回収スクリューの搬送方向一端部に隣接配置されて回収スクリューからのトナーを受けて回収スクリューの軸方向と交差する方向へ搬送する無端状の搬送ベルトと、該搬送ベルトの無端状のベルト本体の外周面に所定の周方向間隔で配置されたフィンと、を備えたトナー回収装置において、上記搬送ベルトの外周面に配置されるフィンの幅方向の回収スクリュー側端縁を越えて拡張することにより形成した拡大部を備えたことを特徴とする。
請求項２の発明は、上記フィン部の拡大部を、上記回収スクリューの螺旋羽根の終端部を越えて回収スクリュー側へ拡大させたことを特徴とする。
請求項３の発明は、回収したトナーを軸方向へ搬送する回収スクリューと、該回収スクリューの搬送方向一端部に隣接配置されて回収スクリューからのトナーを受けて回収スクリューの軸方向と交差する方向へ搬送する無端状の搬送ベルトと、該搬送ベルトの無端状のベルト本体の外周面に所定の周方向間隔で配置されたフィンと、該ベルト本体に所定の周方向間隔で貫通形成された駆動用穴と、を備えたトナー回収装置において、上記搬送ベルトの内部に掻取り部材を配置して搬送ベルトの下側の内周面に摺接させたことを特徴とする。
請求項４の発明は、上記掻取り部材の上部に落下トナー規制板を設けたことを特徴とする。
請求項５の発明は、上記掻き取り部材と上記落下トナー規制板とを一体構成にしたことを特徴とする。
請求項６の発明に係る画像形成ユニットは、請求項１乃至５の何れか一項に記載のトナー回収装置と、現像装置と、感光体ドラムとを備えたことを特徴とする。
請求項７の発明に係る画像形成装置は、請求項１乃至５の何れか一項に記載のトナー回収装置、又は請求項６に記載の画像形成ユニットを備えたことを特徴とする。
【０００６】
【発明の実施の形態】
以下、本発明を添付図面に示した形態例により詳細に説明する。図１は本発明のトナー回収装置を備えた画像形成ユニットの一例の一部断面斜視図であり、図２はその平面図、図３は正面縦断面図、図４は一形態例のトナー回収装置の要部断面図である。図１等に示した画像形成ユニットは、現像装置１、搬送ベルト３、トナー回収スクリュー４、感光体ドラム６、クリーニングブレード９等を備える。現像装置１は、ハウジング１ａ、内部にトナー攪拌部１ｂ等を備える。
感光体ドラム６の周面に転写後に残留したトナーは、ブレード９により掻落され、回収スクリュー４の回転によって矢印方向へ搬送される。回収スクリュー４の終端部には搬送ベルト３が位置しており、回収スクリュー４の終端部から落下したトナーは搬送ベルト３の上面に移送され、搬送ベルト３上を矢印Ａ方向に搬送される。２ａ、２ｂは搬送ベルト３を駆動する為のプーリである。
回収スクリュー４は、感光体ドラム６とギヤで連結されており、感光体が回転している時は常時回転している。回収スクリュー４の端部にはトナー搬送ベルトを駆動するためのプーリ２ａが取り付けてあり、搬送ベルトはこれと従動プーリ２ｂにより回転し、回収スクリュー４によって搬送されてきた残留トナーを搬送ベルト３で剤攪拌部へ送る構成になっている。
図４は本発明の一形態例の搬送ベルトの構成を示す断面図（図２のＡ−Ａ断面図）であり、搬送ベルトの周面に所定の配置で設けられたフィン部の幅を広くしたものの形態例である。回収スクリュー４及び搬送ベルト３は、ケース１０により包囲されており、搬送ベルト３は、回収スクリュー４の端部のプーリ２ａに巻きかけられたベルト本体１１と、ベルト本体１１の周面に所定の周方向間隔で突設されたフィン１２を有する。
【０００７】
図１０に示したように従来の搬送ベルトのフィンは、ベルト本体の幅と同等の幅を有した板部材であり、従来のフィンの面積、形状は、回収スクリュー４によって搬送されてくるトナー量が通常量である場合を想定しており、通紙ジャム等に起因して感光体上の黒ベタ画像がそのままクリーニングブレード９により除去されることにより大量のトナーが一挙に搬送されてくる事態は想定していなかった。このため、大量のトナーが一挙に搬送されてきた場合には、回収スクリュー４の終端部から搬送ベルト３へのトナーの受渡がスムーズに行われず、搬送性の低下等の不具合が生じたことは前述の如くである。
このような不具合が生じる原因は、ベルト３のフィン１２の面積が大量のトナーを受けるのに不十分であったからであった。これに対して、本発明では、回収スクリュー４の螺旋羽根の終端部４ａとプーリ２ａとの間の距離Ｌを従来と一定に維持しつつ、フィン１２の幅方向一端縁（スクリュー側端縁）を図示のように台形状に（ベルト本体の幅方向一端縁を越えて）延長させることにより、フィン１２の面積を増大させて回収スクリュー４からのトナー量が多い場合に於ても確実にトナーを受入れて現像室等に搬送できるようにしている。つまり、フィン１２をスクリュー側に突出させた拡大部１２ａを設けることにより、搬送ベルト３の搬送能力を向上させた点が特徴的である。
なお、この形態例の拡大部１２ａは、回収スクリュー４の螺旋羽根の終端部４ａの位置と同等か、その手前で終端している。この結果、回収スクリュー４と搬送ベルト３との受け渡し部に大量のトナーが滞留して、搬送能力の低下をもたらす不具合がなくなる。
【０００８】
次に、図５は本発明の他の形態例であり、図４に示した搬送ベルト３のフィン１２の面積を更に大きくする工夫をしたものである。この形態例のフィン１２は、図４の拡大部１２ａよりも更に面積（突出量）の大きい拡大部１２ｂを有し、この拡大部１２ｂを受入れる為にケース１０の一部１０ａを大きく構成している。
具体的には、フィン１２を収容する為に大径に構成していたケースの一部１０ａを回収スクリュー方向に延長させることにより、拡大部１２ｂを内部に受入れ得るように構成している。この形態例でも、フィン１２の面積を増大させて回収スクリュー４からのトナー量が多い場合に於ても確実にトナーを受入れて現像室等に搬送できるようにしている。つまり、フィン１２をスクリュー側に突出させた拡大部１２ｂを設けることにより、搬送ベルト３の搬送能力を向上させた点が特徴的である。
また、この拡大部１２ｂは、図４の拡大部１２ａよりも、その端縁が、回収スクリュー４の螺旋羽根の終端部４ａを乗り越えてスクリュー側に拡大している点が特徴的である。この結果、回収スクリュー４と搬送ベルト３との受け渡し部に大量のトナーが滞留して、搬送能力の低下をもたらす不具合がなくなる。この搬送能力は、図４の形態例の搬送ベルト３よりも高いものとなっている。なお、回収スクリュー４の羽根部の終端部４ａとプーリ２ａとの間の距離Ｌは、図４の場合と同等であるので、装置の軸方向長が増大する訳ではない。
【０００９】
次に、図６は、本発明の他の形態例の搬送ベルト部分の構成を示す分解斜視図であり、この形態例の搬送ベルト３は、ベルト本体１１に所定の間隔で駆動用穴１５が形成されている。駆動用穴１５は、プーリ２ａ，２ｂの外周面に設けた係合用の突起（図示せず）が嵌合することにより、ベルトの回転駆動を確実なものにする手段である。
前述のようにこれら駆動用穴１５から回収トナーが搬送ベルト内部に落下すると、プーリ２ａ，２ｂとベルト３との接触部に入り込んで固まり、これが現像室内に入り込むと画質を悪化させる原因となる。
【００１０】
図７はこのような不具合を解決する為の構成を備えた搬送ベルトの一例の正面図であり、この形態例の搬送ベルト３はその内部に掻取り部材２０を配置した構成が特徴的である。即ち、掻取り部材２０は、搬送ベルト３の内周面（底面）に先端が摺接するように固定された部材であり、ゴム板、樹脂板、金属板等から構成し、ベルト３の内底面に落下して矢印方向へ搬送されようとするトナーＴを掻取り部材２０の先端で掻きとってベルト３の幅方向両端縁から落下させるようにしている。
落下したトナーはケース１０の内底面に一旦落ち、移動するフィン１２によって現像室側へ搬送される。この結果、ベルト内に入り込んだトナーは、従動プーリ２ｂと搬送ベルト３に挟まれることがなくなる。なお、掻取り部材２０の形状としては、図示の逆字型のものは一例であり、単なる平板状のものをベルトの移動方向に対してカウンター方向に摺接させる等々、種々の変形が可能である。
【００１１】
次に、図８は図７の形態例の変形例であり、この形態例は、掻取り部材２０の上部に落下トナー規制板２１を所定の傾斜角度をもって配置させることにより、搬送ベルト駆動用穴１５から落下してくるトナーを受けとめ、掻取り部材２０の前方に落下させて、掻取りを確実にさせるようにしている。即ち、この規制板２１の位置は、プーリ２ｂの左側近傍であって、駆動用穴１５から落下したトナーが掻取り部材２０の右側（プーリ２ｂ寄り）へ落下することを防止し得る位置に設定する。
掻取り部材２０の機能と、掻取られたトナーの行方は上記形態例の場合と同様である。
【００１２】
次に、図９は図７及び図８の形態例の変形例であり、図７の掻取り部材と、図８の落下トナー規制板２１とを一体化した落下トナー規制掻取り部材２２を備えた構成が特徴的である。落下トナー規制掻取り部材２２は、掻取り部２０Ａと、落下トナー規制部２１Ａとを一体化した構成を備え、各部２０Ａ、２１Ａは、夫々、上述した掻取り部材２０と、規制板２１の機能を備える。従って、一枚の部材２２の一端を搬送ベルト内周面に接触させトナーを掻き取り、もう一端を従動プーリと搬送ベルト内周面の間に角度をもって設置させ落下してくるトナーを受けとめ掻き取り部材前に落とすことができ、部品点数を低減できるメリットを提供する。
なお、図７、図８、図９の各形態例は、図４、図５の拡大部を有したフィンを備えた搬送ベルトにも適用することができる。
【００１３】
【発明の効果】
以上のように、請求項１の発明は、搬送ベルトの外周面に配置されるフィンの幅方向の回収スクリュー側端縁を、ベルト本体の幅方向一端縁を越えて拡張することにより形成した拡大部を備えたので、回収スクリュー側から一挙に多量のトナーが搬送ベルト上に移送される場合に於ても、フィンの面積が大きいので増量されたトナーを確実に受け、搬送することができる。従って、この増量分のトナーが回収スクリューの負荷となって搬送性を低下させる事態の発生を防止できる。
請求項２の発明は、上記フィン部の拡大部を、上記回収スクリューの螺旋羽根の終端部を越えて回収スクリュー側へ拡大させたので、請求項１の効果を更に高めることができる。
請求項３の発明は、回収したトナーを軸方向へ搬送する回収スクリューと、該回収スクリューの搬送方向一端部に隣接配置されて回収スクリューからのトナーを受けて搬送する無端状の搬送ベルトと、該ベルト本体に所定の周方向間隔で貫通形成された駆動用穴と、を備えたトナー回収装置において、上記搬送ベルトの内部に掻取り部材を配置して搬送ベルトの下側の内周面に摺接させた。このため、トナーが駆動プーリと搬送ベルトの間に挟まれて凝集することが防止されるので、異常画像の発生を防ぐことができる。
請求項４の発明は、上記掻取り部材の上部に落下トナー規制板を設けたので、駆動穴から落下してくるトナーを確実に掻取り部材によって除去することができる。
請求項５の発明は、上記掻き取り部材と上記落下トナー規制板とを一体構成にしたので、安価でコンパクトな装置構成により凝集トナーによる異常画像を防止することができる。
請求項６の発明は、上記各請求項の効果を備えた画像形成ユニットを提供することができる。
請求項７の発明は、上記各請求項の効果を備えた画像形成装置を提供することができる。
【図面の簡単な説明】
【図１】本発明のトナー回収装置を備えた画像形成ユニットの一例の一部断面斜視図。
【図２】図１の平面図。
【図３】正面縦断面図。
【図４】本発明の一形態例のトナー回収装置の要部断面図。
【図５】本発明の他の形態例のトナー回収装置の要部断面図。
【図６】本発明の他の形態例を適用したトナー回収装置の要部構成斜視図。
【図７】本発明の他の形態例の搬送ベルトの構成を示す正面図。
【図８】本発明の他の形態例の搬送ベルトの構成を示す正面図。
【図９】本発明の他の形態例の搬送ベルトの構成を示す正面図。
【図１０】従来例の説明図。
【図１１】従来例の説明図。
【符号の説明】
１現像装置、２ａ，２ｂプーリ、３搬送ベルト、４トナー回収スクリュー、４ａ螺旋羽根の終端部、６感光体ドラム、９クリーニングブレード、１０ケース、１１ベルト本体、１２フィン、１２ａ，１２ｂ拡大部。２０掻取り部材、２１落下トナー規制板。[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an improvement in a toner recovery device, and more particularly, in a toner recovery device that transports toner removed from a photoreceptor or the like and recovered by a recovery screw to a developing device using a transport belt, a large amount of toner is transported by the transport belt. The present invention relates to a toner recovery device that can solve problems that occur when the toner is transported to the belt and problems that occur when toner enters between the conveyor belt and the pulley.
[0002]
[Prior art]
In an electrophotographic image forming apparatus, an image is formed by transferring a toner image formed on a photoreceptor onto a transfer sheet and then fixing it. In an image forming apparatus equipped with a toner recycling mechanism, toner remaining on a photoconductor or an intermediate transfer belt after transfer is scraped off by a cleaning means such as a cleaning blade and then developed through a recovery screw and a conveyor belt. It is transported to the device for reuse. In addition, the collected toner is collected in a collection container.
FIG. 10 is a diagram for explaining the configuration of the residual toner recovery device disclosed in Japanese Utility Model Laid-Open No. 5-81863. The recovery screw 101 for transporting the toner recovered from above the photoconductor and the like and the transport screw 101 have transported the residual toner. And an endless transport belt 102 that transports the toner toward the collection container or the developing unit 103. In addition, engagement holes 102a are provided on the surface of the conveyance belt 102 at a predetermined pitch, and the engagement holes are engaged with engagement protrusions on a pulley peripheral surface on which the conveyance belt is stretched, thereby preventing the belt from slipping. I try to prevent it.
FIG. 11 is an explanatory diagram of the configuration of a conveyor belt constituting the toner recovery device disclosed in Japanese Utility Model Publication No. Hei 3-29971. The conveyor belt 112 stretched endlessly by pulleys 110 and 111 is provided on the peripheral surface of the conveyor belt 112. Blades 113 are provided at a predetermined pitch. Since the blade 113 has a configuration capable of sliding contact with the inner bottom surface and a part of the side wall of the housing 115 at the tip thereof, the toner that has entered the bottom of the housing is quickly collected, and the residual toner, Solidification can be prevented.
However, in the conventional toner recovery apparatus, as shown in FIG. 10, the fin 101 a or the blade 101 b located at the terminal end of the recovery screw 101 is disposed close to the transport belt 102, so When a large amount of toner is conveyed all at once, a large amount of toner collides with the end surface of the conveyance belt itself or the end surface of the blade 113, so that the toner is not smoothly transferred, and as a result, the toner temporarily staying in this portion This is a load for driving the recovery screw and the conveyor belt, leading to a decrease in transportability.
[0003]
The case where a large amount of toner is conveyed all at once is generated when, for example, a black solid image remains on the photosensitive member due to the fact that the transfer has not been performed due to paper jam, for example. Then, a large amount of toner is conveyed by the collection screw. Since the normal amount of collected toner is not so large, the conveying capacity of the collecting screw and the conveying belt is set according to the case where the amount of collected toner is small. However, when a large amount of toner is collected for the above reason, As a result, the conveyance capability is not in time, resulting in a decrease in conveyance performance and an increase in load.
In addition, as shown in FIG. 11, when the collected toner T is conveyed to the developing chamber side by the conveyance belt 112, the collected toner that could not be conveyed is again sent on the conveyance belt to the collection screw (drive side) side. At this time, there is a possibility that the roller falls from the driving hole of the conveying belt (corresponding to the engagement hole 102a in FIG. 10) to the inner peripheral surface of the conveying belt and is sandwiched between the driven roller and the conveying belt. If the conveyor belt is continuously used in this state, the sandwiched toner is aggregated and then peeled off and supplied as a toner lump into the developing device, which causes an abnormal image.
[0004]
[Problems to be solved by the invention]
The present invention has been made in view of the above, and after the toner remaining on the photosensitive member or the like is removed by a cleaning means, the toner is recovered in a developing device or a recovery container through a recovery screw and a conveyor belt. In the image forming apparatus, when a large amount of collected toner falls from the end of the collecting screw to the conveying belt side, the toner transfer capability from the end portion of the fin portion of the collecting screw to the conveying belt is generated due to being too low. The object is to prevent a decrease in transportability due to a large amount of collected toner.
Further, when the collected toner is transported to the developing chamber side by the transport belt, the recovered toner falls from the drive hole of the transport belt to the inner peripheral surface of the transport belt and is sandwiched between the pulley and the transport belt. An object of the present invention is to prevent an abnormal image from being generated when the aggregated toner is peeled off and sent to the developing chamber.
[0005]
[Means for Solving the Problems]
In order to achieve the above object, the invention of claim 1 is directed to a collection screw for conveying the collected toner in the axial direction and a collection screw that is disposed adjacent to one end of the collection screw in the conveyance direction and receives the toner from the collection screw. A toner collection device comprising: an endless transport belt that transports in a direction that intersects the axial direction of the belt; and fins that are disposed on the outer peripheral surface of the endless belt body of the transport belt at predetermined circumferential intervals. It has an enlarged portion formed by extending beyond the collection screw side end edge in the width direction of the fin disposed on the outer peripheral surface of the conveyor belt.
The invention of claim 2 is characterized in that the enlarged portion of the fin portion is enlarged to the recovery screw side beyond the terminal portion of the spiral blade of the recovery screw.
According to a third aspect of the present invention, there is provided a recovery screw that conveys the collected toner in the axial direction, and a direction that is disposed adjacent to one end of the recovery screw in the conveyance direction and that receives the toner from the recovery screw and intersects the axial direction of the recovery screw. An endless transport belt that transports to the outer periphery of the transport belt, fins that are disposed on the outer peripheral surface of the endless belt body of the transport belt at predetermined circumferential intervals, and a drive that is formed through the belt body at predetermined circumferential intervals. In the toner collecting device provided with the use hole, a scraping member is disposed inside the conveying belt and is brought into sliding contact with the inner peripheral surface on the lower side of the conveying belt.
According to a fourth aspect of the present invention, there is provided a falling toner regulating plate provided on an upper portion of the scraping member.
The invention according to claim 5 is characterized in that the scraping member and the falling toner regulating plate are integrated.
According to a sixth aspect of the present invention, an image forming unit includes the toner collecting device according to any one of the first to fifth aspects, a developing device, and a photosensitive drum.
An image forming apparatus according to a seventh aspect of the invention includes the toner collecting device according to any one of the first to fifth aspects or the image forming unit according to the sixth aspect.
[0006]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the present invention will be described in detail with reference to embodiments shown in the accompanying drawings. FIG. 1 is a partial cross-sectional perspective view of an example of an image forming unit provided with a toner recovery apparatus of the present invention, FIG. 2 is a plan view thereof, FIG. 3 is a front vertical cross-sectional view, and FIG. It is principal part sectional drawing of an apparatus. The image forming unit shown in FIG. 1 and the like includes a developing device 1, a conveyor belt 3, a toner collecting screw 4, a photosensitive drum 6, a cleaning blade 9, and the like. The developing device 1 includes a housing 1a and a toner stirring unit 1b inside.
The toner remaining on the peripheral surface of the photosensitive drum 6 after being transferred is scraped off by the blade 9 and conveyed in the arrow direction by the rotation of the recovery screw 4. The conveyor belt 3 is located at the end of the collection screw 4, and the toner dropped from the end of the collection screw 4 is transferred to the upper surface of the conveyor belt 3 and is conveyed on the conveyor belt 3 in the direction of arrow A. Reference numerals 2a and 2b denote pulleys for driving the conveyor belt 3.
The collection screw 4 is connected to the photosensitive drum 6 by a gear, and always rotates when the photosensitive member is rotating. A pulley 2 a for driving the toner conveying belt is attached to the end of the collecting screw 4, and the conveying belt is rotated by this and the driven pulley 2 b, and the residual toner conveyed by the collecting screw 4 is transferred by the conveying belt 3. It is configured to send to the agent stirring section.
FIG. 4 is a cross-sectional view (cross-sectional view taken along the line AA in FIG. 2) showing the configuration of the conveyance belt according to an embodiment of the present invention. This is an example of the form. The collection screw 4 and the conveyance belt 3 are surrounded by a case 10, and the conveyance belt 3 has a belt body 11 wound around a pulley 2 a at the end of the collection screw 4 and a predetermined circumferential surface of the belt body 11. Fins 12 are provided protruding at circumferential intervals.
[0007]
As shown in FIG. 10, the fins of the conventional transport belt are plate members having a width equivalent to the width of the belt body, and the area and shape of the conventional fins are the amount of toner transported by the recovery screw 4. Is a normal amount, and a situation in which a large amount of toner is conveyed all at once by removing the black solid image on the photosensitive member as it is by the cleaning blade 9 due to a paper jam or the like. I did not expect. For this reason, when a large amount of toner is transported all at once, the transfer of toner from the end of the recovery screw 4 to the transport belt 3 is not performed smoothly, and problems such as a decrease in transportability have occurred. As described above.
The reason why such a problem occurs is that the area of the fin 12 of the belt 3 is insufficient to receive a large amount of toner. On the other hand, in the present invention, one end edge in the width direction of the fin 12 (screw side end edge) while maintaining the distance L between the terminal end 4a of the spiral blade of the recovery screw 4 and the pulley 2a constant. Is extended in a trapezoidal shape (exceeding one edge in the width direction of the belt body) as shown in the figure, thereby increasing the area of the fin 12 and ensuring that the amount of toner from the recovery screw 4 is large. Can be received and conveyed to a developing chamber or the like. That is, it is characteristic that the conveyance capability of the conveyance belt 3 is improved by providing the enlarged portion 12a in which the fins 12 protrude to the screw side.
Note that the enlarged portion 12a of this embodiment is equal to or terminated in front of the position of the terminal portion 4a of the spiral blade of the recovery screw 4. As a result, a large amount of toner stays in the transfer portion between the collection screw 4 and the conveyance belt 3, thereby eliminating a problem that causes a decrease in conveyance capability.
[0008]
Next, FIG. 5 shows another embodiment of the present invention, in which the area of the fins 12 of the conveyor belt 3 shown in FIG. 4 is further increased. The fin 12 of this embodiment has an enlarged portion 12b having a larger area (projection amount) than the enlarged portion 12a of FIG. 4, and a part 10a of the case 10 is configured to be larger in order to receive the enlarged portion 12b. Yes.
Specifically, the enlarged portion 12b can be received inside by extending a part 10a of the case that has been configured to have a large diameter to accommodate the fins 12 in the direction of the recovery screw. Also in this embodiment, the area of the fin 12 is increased so that the toner can be reliably received and conveyed to the developing chamber or the like even when the amount of toner from the recovery screw 4 is large. That is, it is characteristic that the conveyance capability of the conveyance belt 3 is improved by providing the enlarged portion 12b in which the fins 12 protrude to the screw side.
Further, the enlarged portion 12b is characterized in that the edge of the enlarged portion 12b extends over the terminal portion 4a of the spiral blade of the recovery screw 4 and expands to the screw side as compared with the enlarged portion 12a of FIG. As a result, a large amount of toner stays in the transfer portion between the collection screw 4 and the conveyance belt 3, thereby eliminating a problem that causes a decrease in conveyance capability. This conveyance capability is higher than that of the conveyance belt 3 in the embodiment of FIG. In addition, since the distance L between the terminal part 4a of the blade | wing part of the collection | recovery screw 4 and the pulley 2a is equivalent to the case of FIG. 4, the axial direction length of an apparatus does not necessarily increase.
[0009]
Next, FIG. 6 is an exploded perspective view showing the configuration of the conveyor belt portion of another embodiment of the present invention. The conveyor belt 3 of this embodiment has the driving holes 15 in the belt body 11 at predetermined intervals. Is formed. The driving hole 15 is means for ensuring the rotational driving of the belt by engaging engagement protrusions (not shown) provided on the outer peripheral surfaces of the pulleys 2a and 2b.
As described above, when the collected toner falls from the driving holes 15 to the inside of the conveying belt, the toner enters the contact portion between the pulleys 2a and 2b and the belt 3 and hardens. When this enters the developing chamber, the image quality deteriorates.
[0010]
FIG. 7 is a front view of an example of a conveyor belt having a configuration for solving such problems, and the conveyor belt 3 of this embodiment is characterized by a configuration in which a scraping member 20 is disposed therein. . In other words, the scraping member 20 is a member that is fixed so that the tip is in sliding contact with the inner peripheral surface (bottom surface) of the conveyor belt 3, and is composed of a rubber plate, a resin plate, a metal plate, and the like, and the inner bottom surface of the belt 3. The toner T which is about to fall and be conveyed in the direction of the arrow is scraped off at the tip of the scraping member 20 and dropped from both edges in the width direction of the belt 3.
The dropped toner once falls on the inner bottom surface of the case 10 and is conveyed to the developing chamber side by the moving fins 12. As a result, the toner that has entered the belt is not caught between the driven pulley 2 b and the conveyance belt 3. The shape of the scraping member 20 is merely an example of the inverted character shown in the figure, and various modifications are possible, such as a simple flat plate made to slide in the counter direction with respect to the moving direction of the belt. is there.
[0011]
Next, FIG. 8 is a modified example of the embodiment of FIG. 7. In this embodiment, the falling toner regulating plate 21 is disposed at an upper portion of the scraping member 20 with a predetermined inclination angle, whereby a conveying belt driving hole is formed. The toner falling from 15 is received and dropped to the front of the scraping member 20 to ensure the scraping. That is, the position of the regulating plate 21 is set to a position in the vicinity of the left side of the pulley 2b so that the toner dropped from the driving hole 15 can be prevented from dropping to the right side (near the pulley 2b) of the scraping member 20. To do.
The function of the scraping member 20 and the whereabouts of the scraped toner are the same as those in the above embodiment.
[0012]
Next, FIG. 9 is a modification of the embodiment shown in FIGS. 7 and 8, and includes a falling toner regulating scraping member 22 in which the scraping member of FIG. 7 and the falling toner regulating plate 21 of FIG. 8 are integrated. The configuration is characteristic. The falling toner restriction scraping member 22 has a configuration in which a scraping part 20A and a falling toner restriction part 21A are integrated, and each part 20A, 21A has a function of the above-described scraping member 20 and the restriction plate 21, respectively. Is provided. Accordingly, one end of one member 22 is brought into contact with the inner peripheral surface of the conveyor belt to scrape the toner, and the other end is installed at an angle between the driven pulley and the inner peripheral surface of the conveyor belt to receive and scrape the falling toner. It can be dropped in front of the member, providing the advantage of reducing the number of parts.
7, 8, and 9 can also be applied to a conveyor belt that includes fins having the enlarged portions of FIGS. 4 and 5.
[0013]
【The invention's effect】
As described above, the invention according to claim 1 is an expansion formed by extending the recovery screw side end edge in the width direction of the fin disposed on the outer peripheral surface of the conveyor belt beyond the one end edge in the width direction of the belt body. Since the portion is provided, even when a large amount of toner is transferred onto the conveying belt from the collecting screw side, the increased amount of toner can be reliably received and conveyed because the fin area is large. Therefore, it is possible to prevent the occurrence of a situation in which the increased amount of toner becomes a load on the recovery screw and deteriorates the transportability.
According to the second aspect of the present invention, since the enlarged portion of the fin portion is expanded to the recovery screw side beyond the end portion of the spiral blade of the recovery screw, the effect of the first aspect can be further enhanced.
The invention of claim 3 is a collection screw for conveying the collected toner in the axial direction, an endless conveyance belt that is disposed adjacent to one end of the collection screw in the conveyance direction and receives and conveys toner from the collection screw; In a toner recovery apparatus having a driving hole formed through the belt body at predetermined intervals in the circumferential direction, a scraping member is disposed inside the conveyor belt and disposed on an inner peripheral surface below the conveyor belt. Slid in contact. For this reason, the toner is prevented from being agglomerated by being sandwiched between the driving pulley and the conveyance belt, and thus the occurrence of an abnormal image can be prevented.
In the fourth aspect of the present invention, since the falling toner regulating plate is provided above the scraping member, the toner falling from the drive hole can be surely removed by the scraping member.
According to the fifth aspect of the present invention, the scraping member and the falling toner regulating plate are integrally configured, and therefore, an abnormal image due to the aggregated toner can be prevented by an inexpensive and compact device configuration.
The invention of claim 6 can provide an image forming unit having the effects of the above claims.
The invention of claim 7 can provide an image forming apparatus having the effects of the above claims.
[Brief description of the drawings]
FIG. 1 is a partial cross-sectional perspective view of an example of an image forming unit including a toner recovery device of the present invention.
FIG. 2 is a plan view of FIG.
FIG. 3 is a front longitudinal sectional view.
FIG. 4 is a cross-sectional view of a main part of a toner recovery device according to an embodiment of the present invention.
FIG. 5 is a cross-sectional view of a main part of a toner recovery device according to another embodiment of the present invention.
FIG. 6 is a perspective view of a main part configuration of a toner recovery device to which another embodiment of the present invention is applied.
FIG. 7 is a front view illustrating a configuration of a conveyance belt according to another embodiment of the present invention.
FIG. 8 is a front view illustrating a configuration of a conveyance belt according to another embodiment of the present invention.
FIG. 9 is a front view illustrating a configuration of a conveyance belt according to another embodiment of the present invention.
FIG. 10 is an explanatory diagram of a conventional example.
FIG. 11 is an explanatory diagram of a conventional example.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Developing device, 2a, 2b Pulley, 3 Conveying belt, 4 Toner collection screw, 4a End part of spiral blade, 6 Photosensitive drum, 9 Cleaning blade, 10 Case, 11 Belt body, 12 Fin, 12a, 12b Enlarged part 20 scraping member, 21 falling toner regulating plate.

Claims

A collection screw that conveys the collected toner in the axial direction, and an endless conveyance that is disposed adjacent to one end of the collection screw in the conveyance direction, receives the toner from the collection screw, and conveys the toner in a direction that intersects the axial direction of the collection screw A width direction of fins disposed on the outer peripheral surface of the conveyor belt in a toner recovery device comprising: a belt; and fins disposed on the outer peripheral surface of the endless belt body of the transport belt at predetermined circumferential intervals A toner collecting device comprising: an enlarged portion formed by extending the edge of the collecting screw side beyond one edge in the width direction of the belt body.

2. The toner collecting apparatus according to claim 1, wherein an enlarged portion of the fin portion is enlarged toward the collecting screw side beyond a terminal portion of the spiral blade of the collecting screw.

A collection screw that conveys the collected toner in the axial direction, and an endless conveyance that is disposed adjacent to one end of the collection screw in the conveyance direction, receives the toner from the collection screw, and conveys the toner in a direction that intersects the axial direction of the collection screw A belt, fins disposed at a predetermined circumferential interval on the outer peripheral surface of the endless belt body of the conveyor belt, and drive holes formed through the belt body at a predetermined circumferential interval. In the toner collecting apparatus, a scraping member is disposed inside the conveying belt and is brought into sliding contact with an inner peripheral surface below the conveying belt.

4. The toner collecting apparatus according to claim 3, wherein a falling toner regulating plate is provided on an upper portion of the scraping member.

5. The toner collecting apparatus according to claim 3, wherein the scraping member and the falling toner regulating plate are integrated.

An image forming unit comprising the toner recovery device according to claim 1, a developing device, and a photosensitive drum.

An image forming apparatus comprising the toner collecting device according to claim 1 or the image forming unit according to claim 6.