JP2009139476A - Developing device and image forming apparatus - Google Patents

Developing device and image forming apparatus Download PDF

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JP2009139476A
JP2009139476A JP2007313559A JP2007313559A JP2009139476A JP 2009139476 A JP2009139476 A JP 2009139476A JP 2007313559 A JP2007313559 A JP 2007313559A JP 2007313559 A JP2007313559 A JP 2007313559A JP 2009139476 A JP2009139476 A JP 2009139476A
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developer
conveyance path
supply
path
opening
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Yutaka Takahashi
裕 高橋
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Ricoh Co Ltd
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Ricoh Co Ltd
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Abstract

<P>PROBLEM TO BE SOLVED: To provide a developing device having a recovery conveyance path and a stir conveyance path which are located below a supply conveyance path, wherein the developing device is compact and prevents scattering of toner, which is caused by an increase in pressure in the developing device. <P>SOLUTION: A partition member separates: the supply conveyance path 2a along which developer is supplied to a developing sleeve 11; the recovery conveyance path 2b which is disposed below the supply conveyance path and recovers developer; the stir conveyance path which is disposed below the supply conveyance path, stirs and conveys developer supplied from the downstream area of the supply conveyance path and the downstream area of the recovery conveyance path, and transfers the developer to the upstream area of the supply conveyance path. A filter 5 for allowing the passage of air but not toner is disposed above the supply conveyance path. An opening 2f for supplying developer from the downstream area of the supply conveyance path to the stir conveyance path is disposed in a section extended upward from the lowest point of the supply conveyance path of the partition member 33 separating the supply conveyance path and the stir conveyance path. A ventilation opening 2g for ventilating the supply conveyance path and stir conveyance path is disposed further downstream than the opening 2f. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

本発明は、複写機、ファクシミリ、プリンタ等に用いられる現像装置に係り、詳しくは、トナーと磁性キャリアからなる二成分現像剤を用いる現像装置およびこれを用いた画像形成装置に関するものである。   The present invention relates to a developing device used for a copying machine, a facsimile, a printer, and the like, and more particularly to a developing device using a two-component developer composed of toner and a magnetic carrier and an image forming apparatus using the same.

従来、上記現像装置の一つとして、現像剤担持体の軸方向に現像剤を搬送しながら現像剤担持体に現像剤を供給する供給搬送路と、現像剤を攪拌しながら供給搬送路とは逆方向に搬送する攪拌搬送路とを設けて、現像剤を循環させるものが知られている。このような現像装置において、現像領域を通過した現像剤担持体上の現像剤を供給搬送路で回収すると、現像領域でトナーが消費された現像剤と供給搬送路内の現像剤とが混ざり、供給搬送路の下流側ほど現像領域を通過した現像剤が多くなる。このため、供給搬送路の下流側ほど現像剤担持体に供給する現像剤のトナー濃度が低下し、搬送方向上流側と下流側とで画像濃度が異なるという問題があった。   Conventionally, as one of the developing devices, a supply conveyance path for supplying a developer to the developer carrying body while conveying the developer in the axial direction of the developer carrying body and a supply conveyance path for stirring the developer are: There is known an agitating / conveying path that conveys the developer in the reverse direction to circulate the developer. In such a developing device, when the developer on the developer carrying member that has passed through the development area is collected in the supply conveyance path, the developer in which the toner has been consumed in the development area and the developer in the supply conveyance path are mixed, The more developer that has passed through the development area, the more downstream the supply conveyance path. For this reason, there is a problem that the toner density of the developer supplied to the developer carrier decreases toward the downstream side of the supply conveyance path, and the image density differs between the upstream side and the downstream side in the conveyance direction.

この問題は、特許文献１に記載の現像装置のように、供給搬送路及び攪拌搬送路とは別に現像剤を回収する回収搬送路を設けることで解決できる。この現像装置では、現像剤担持体に現像剤を供給する供給搬送路と、供給搬送路の下方に配置され供給搬送路と反対方向に現像剤を搬送する攪拌搬送路と、現像剤担持体の下方に配置され現像剤担持体から現像剤を回収しながら供給搬送路と同方向に現像剤を搬送する回収搬送路とを備えている。供給搬送路、回収搬送路及び攪拌搬送路は、それぞれ仕切り部材によって仕切られており、攪拌搬送路の下流側端部の供給搬送路との仕切り部材には、供給搬送路に攪拌した現像剤を受け渡す開口部を設けている。また、供給搬送路の下流側端部の攪拌搬送路との仕切り部材には攪拌搬送路に余剰現像剤を受け渡す開口部、回収搬送路の下流側端部の攪拌搬送路との仕切り部材には攪拌搬送路に回収現像剤を受け渡す開口部をそれぞれ設けて、現像剤を循環させている。このように、現像剤担持体への現像剤の供給と回収との機能を分離して行うことにより、現像剤担持体に供給する現像剤のトナー濃度が一定となり、濃度ムラの発生を防止することができる。   This problem can be solved by providing a recovery conveyance path that collects the developer separately from the supply conveyance path and the agitation conveyance path, as in the developing device described in Japanese Patent Application Laid-Open No. 2005-228867. In this developing device, a supply conveyance path for supplying the developer to the developer carrying member, a stirring conveyance path that is disposed below the supply conveyance path and conveys the developer in a direction opposite to the supply conveyance path, and a developer carrying member A recovery conveyance path that is disposed below and conveys the developer in the same direction as the supply conveyance path while collecting the developer from the developer carrying member is provided. The supply conveyance path, the recovery conveyance path, and the agitation conveyance path are each partitioned by a partition member, and the developer agitated in the supply conveyance path is supplied to the partition member with the supply conveyance path at the downstream end of the agitation conveyance path. A passing opening is provided. Also, the partition member for the agitating and conveying path at the downstream end of the supply conveying path is an opening for delivering the excess developer to the agitating and conveying path, and the partitioning member for the agitating and conveying path at the downstream end of the collecting and conveying path. Each has an opening for delivering the collected developer to the agitation transport path to circulate the developer. In this way, by separately performing the functions of supplying and collecting the developer to the developer carrying member, the toner concentration of the developer supplied to the developer carrying member becomes constant, and density unevenness is prevented. be able to.

また、一般的に現像装置では、現像剤担持体の回転により発生した気流により周辺空気が装置内に吸い込まれて装置内の内圧が上昇し、装置内外の圧力差によって、装置内に浮遊するトナーが僅かな隙間から装置外へ飛散してしまうという不具合がある。特許文献２には、現像装置の内圧上昇を抑えて現像装置からのトナー飛散を抑制するものとして、トナーを通過させず空気を通過させるフィルタを設けた現像装置が記載されている。これは、フィルタを介して現像装置内の気流を装置外に排出して現像装置内の内圧の上昇を抑えると共に、浮遊するトナーを気流に乗せてフィルタで捕集することで、現像装置からのトナー飛散を抑制するものである。また、フィルタは、十分な通気を確保すると共に、フィルタの目詰まりをし難くするために、現像装置の上側に設置し、効率よく現像装置内の気流を装置外に排出して内圧の上昇を抑えている。   In general, in a developing apparatus, the ambient air is sucked into the apparatus due to the air flow generated by the rotation of the developer carrier, and the internal pressure in the apparatus rises, and the toner floating in the apparatus due to the pressure difference between the inside and outside of the apparatus. However, there is a problem in that the air scatters out of the device through a slight gap. Patent Document 2 describes a developing device provided with a filter that does not allow toner to pass therethrough and suppresses toner scattering from the developing device by suppressing an increase in internal pressure of the developing device. This is because the airflow in the developing device is discharged out of the device through the filter to suppress the increase in the internal pressure in the developing device, and the floating toner is carried on the airflow and collected by the filter, It suppresses toner scattering. In addition, the filter is installed on the upper side of the developing device to ensure sufficient ventilation and to prevent clogging of the filter, and the internal air pressure is increased by efficiently discharging the air flow in the developing device to the outside. It is suppressed.

特開２００１−２９０３６８号公報JP 2001-290368 A 特開昭６０−５１８６１号公報JP-A-60-51861

上述の回収搬送路と攪拌搬送路とを供給搬送路の下方に設けた現像装置においては、現像剤担持体の回転により現像剤が回収搬送路へ回収されると共に、回収搬送路に周辺気流を取り込んで現像装置内圧を上昇させる。この内圧上昇を防止するためには、現像装置の上側、すなわち、供給搬送路の上方にフィルタを設ける。そして、回収搬送路に取り込まれた気流を、回収搬送路と連通する攪拌搬送路へ通気し、さらに攪拌搬送路と連通する上方の供給搬送路へと通気して、供給搬送路の上方のフィルタから排気するようにしたい。しかしながら、回収搬送路からフィルタまでの間で十分な通気が確保できず、回収搬送路の内圧上昇が抑えらずに、トナー飛散が発生してしまうことがあった。   In the developing device in which the recovery conveyance path and the agitation conveyance path described above are provided below the supply conveyance path, the developer is recovered to the recovery conveyance path by the rotation of the developer carrier, and a peripheral airflow is generated in the recovery conveyance path. Take in and increase the internal pressure of the developing device. In order to prevent this increase in internal pressure, a filter is provided above the developing device, that is, above the supply conveyance path. Then, the airflow taken into the collection conveyance path is ventilated to the stirring conveyance path communicating with the collection conveyance path, and further to the upper supply conveyance path communicating with the agitation conveyance path, and the filter above the supply conveyance path I want to exhaust from. However, sufficient ventilation cannot be secured between the collection conveyance path and the filter, and toner scattering may occur without suppressing an increase in internal pressure in the collection conveyance path.

この現像装置では、回収搬送路と攪拌搬送路とは、回収搬送路の下流部側面に設けられた開口部により連通しているが、現像剤の受け渡しは現像剤が存在する開口部の下部を介しておこなわれ、開口部上部の現像剤の嵩が達しない領域では通気がおこなわれる。一方、攪拌搬送路と上方の供給搬送路とは、供給搬送路の上流部底面および下流部底面に設けられた二つの開口部により連通している。このうち、攪拌搬送路の下流部から上方の供給搬送路への現像剤の受け渡しは、供給搬送路の上流側底面に設けられた開口部を介して攪拌搬送路の現像剤を溢れさせているので、開口部は現像剤で塞がれた状態になり易く、十分な通気が確保できない。また、上方の供給搬送路から下方の攪拌搬送路への現像剤の受け渡しは、供給搬送路の下流側底面に設けられた開口部を介して現像剤を落下させており、開口部面積に対して現像剤量が多い場合、開口部が現像剤で塞がれた状態になり十分な通気が確保できない。このように、下方の攪拌搬送路と上方の供給搬送路とが連通する開口部は、現像剤で塞がれた状態になり易く、上方の供給搬送路と通気が確保できないことがある。上方の供給搬送路と十分な通気が確保できないと、下方の回収搬送路と攪拌搬送路とでは内圧が上昇したままになってしまう。   In this developing apparatus, the collection conveyance path and the agitation conveyance path are communicated with each other through an opening provided on the side surface of the downstream portion of the collection conveyance path, but the developer is transferred at a lower portion of the opening where the developer exists. In the region where the bulk of the developer at the upper part of the opening is not reached, ventilation is performed. On the other hand, the stirring conveyance path and the upper supply conveyance path are communicated with each other by two openings provided on the upstream bottom surface and the downstream bottom surface of the supply conveyance path. Among these, the transfer of the developer from the downstream portion of the stirring conveyance path to the upper supply conveyance path causes the developer in the stirring conveyance path to overflow through the opening provided on the bottom surface on the upstream side of the supply conveyance path. As a result, the opening is likely to be blocked with the developer, and sufficient ventilation cannot be ensured. In addition, the developer is transferred from the upper supply conveyance path to the lower stirring conveyance path by dropping the developer through the opening provided on the bottom surface on the downstream side of the supply conveyance path. If the amount of the developer is large, the opening is closed with the developer and sufficient ventilation cannot be ensured. As described above, the opening where the lower agitation conveyance path and the upper supply conveyance path communicate with each other is likely to be clogged with the developer, and the upper supply conveyance path and the ventilation may not be ensured. If the upper supply conveyance path and sufficient ventilation cannot be ensured, the internal pressure remains elevated in the lower collection conveyance path and the stirring conveyance path.

供給搬送路、攪拌搬送路および供給搬送路の下流部から攪拌搬送路に現像剤を受け渡す開口部を軸方向下流側に延ばして、開口部が現像剤に塞がれずに供給搬送路と攪拌搬送路との通気をおこなう領域を確保するようにすることも考えられる。しかし、現像装置が大型化してしまうというデメリットがある。   The supply conveyance path, the agitation conveyance path, and the opening that delivers the developer from the downstream portion of the supply conveyance path to the agitation conveyance path are extended to the downstream side in the axial direction, and the opening is not blocked by the developer and the agitation conveyance path and the agitation It is also conceivable to secure a region for venting the conveyance path. However, there is a demerit that the developing device becomes large.

本発明は、以上の背景に鑑みなされたものであり、その目的とするところは、現像剤の供給おこなう供給搬送路よりも下方に、回収をおこなう回収搬送路と攪拌をおこなう攪拌搬送路とを備えた現像装置及びこれを用いた画像形成装置において、現像装置内圧上昇によるトナー飛散を防止できる小型の現像装置及びこれを用いた画像形成装置を提供することである。   The present invention has been made in view of the above background, and the object of the present invention is to provide a recovery conveyance path for collecting and a stirring conveyance path for stirring below a supply conveyance path for supplying developer. It is an object of the present invention to provide a small developing device capable of preventing toner scattering due to an increase in internal pressure of the developing device and an image forming device using the developing device.

上記目的を達成するために、請求項１の発明は、トナーと磁性キャリアとからなる現像剤を担持して回転により潜像担持体との対向部まで搬送する現像剤担持体と、該現像剤担持体の軸線方向に沿って現像剤を攪拌搬送して該現像剤担持体に供給する第１現像剤攪拌搬送手段を有する第１現像剤搬送路と、該第１現像剤攪拌搬送手段よりも下方に配置され該潜像担持体との対向部通過後の該現像剤担持体から現像剤を回収して、該第１現像剤攪拌搬送手段と同方向に搬送する第２現像剤攪拌搬送手段を有する第２現像剤搬送路と、該第１現像剤攪拌搬送手段よりも下方に配置され、該第１現像剤攪拌搬送手段により該現像剤担持体に供給されずに該第１現像剤搬送路の搬送方向下流部まで搬送された現像剤と、該第２現像剤攪拌搬送手段により該現像剤担持体から回収され該第２現像剤搬送路の搬送方向下流部まで搬送された現像剤との供給を受け、該第１現像剤攪拌搬送手段と逆方向に現像剤を攪拌搬送して下流側で該第１現像剤攪拌搬送手段に受け渡す第３現像剤攪拌搬送手段を有する第３現像剤搬送路とを有し、該第１現像剤搬送路、該第２現像剤搬送路及び該第３現像剤搬送路は仕切り部材により仕切られる現像装置において、
トナーを通過させずに空気を通過させるフィルタを上記第１現像剤搬送路の上方に設け、該第１現像剤搬送路と上記第３現像剤搬送路とを仕切る仕切り部材は該第１現像剤搬送路最下点より上方へ延伸したものであり、該第１現像剤搬送路の搬送方向下流部から該第３現像剤搬送路に現像剤を供給するための第１現像剤供給用開口部を、該第１現像剤搬送路と該第３現像剤搬送路との仕切り部材の該第１現像剤搬送路最下点より上方の位置に設け、該第１現像剤搬送路と該第３現像剤搬送路とを通気するための通気用開口部を、該第１現像剤供給用開口部よりも該第１現像剤搬送路の搬送方向下流で、且つ、該第１現像剤供給用開口部の最上部よりも上方の位置に設けたことを特徴とするものである。
請求項２の発明は、請求項１の現像装置において、上記第３現像剤攪拌搬送手段の現像剤搬送方向下流部で現像剤を上記第１現像剤攪拌搬送手段に受け渡すために、上記第３現像剤搬送路の搬送方向下流部の上記第１現像剤搬送路との仕切り部材に設ける第３現像剤供給用開口部を、上記現像剤担持体が上記潜像担持体にトナーを供給する現像領域の該軸線方向の幅である現像領域幅内に配置することを特徴とするものである。
請求項３の発明は、請求項１または２の現像装置において、上記第１現像剤供給用開口部を上記現像剤担持体が上記潜像担持体にトナーを供給する現像領域の該軸線方向の幅である現像領域幅内に配置することを特徴とするものである。
請求項４の発明は、請求項１、２または３の何れかの現像装置において、上記通気用開口部を上記現像剤担持体が上記潜像担持体にトナーを供給する現像領域の該軸線方向の幅である現像領域幅内に配置することを特徴とするものである。
請求項５の発明は、潜像担持体と、該潜像担持体を帯電させるための帯電手段と、該潜像担持体上に静電潜像を形成するための潜像形成手段と、該静電潜像を現像してトナー像化するための現像手段とを有する画像形成装置において、上記現像手段として、請求項１、２、３または４の現像装置を採用することを特徴とするものである。 In order to achieve the above object, a first aspect of the present invention is to provide a developer carrying member that carries a developer composed of toner and a magnetic carrier and conveys the developer to a portion facing the latent image carrier by rotation, and the developer. A first developer conveying path having first developer agitating and conveying means for agitating and conveying the developer along the axial direction of the carrier and supplying the developer to the developer carrying body; and more than the first developer agitating and conveying means Second developer agitating and conveying means that is disposed below and collects the developer from the developer carrying body after passing through a portion facing the latent image carrier and conveys the developer in the same direction as the first developer agitating and conveying means. A second developer conveying path having a first developer agitating and conveying means disposed below the first developer agitating and conveying means without being supplied to the developer carrier by the first developer agitating and conveying means. A developer conveyed to a downstream portion in the conveyance direction of the path and the second developer agitating and conveying means. The developer is recovered from the developer carrying member and supplied to the downstream portion in the transport direction of the second developer transport path, and the developer is stirred and transported in the direction opposite to the first developer agitating and transporting means. A third developer conveying path having a third developer agitating and conveying means that is transferred downstream to the first developer agitating and conveying means, the first developer conveying path, and the second developer conveying path. And the third developer transport path is divided by a partition member,
A filter that allows air to pass without passing through the toner is provided above the first developer transport path, and a partition member that partitions the first developer transport path and the third developer transport path is the first developer. A first developer supply opening that extends upward from the lowest point of the transport path and supplies developer to the third developer transport path from a downstream portion in the transport direction of the first developer transport path. At a position above the lowest point of the first developer transport path of a partition member between the first developer transport path and the third developer transport path, and the first developer transport path and the third developer transport path. A ventilation opening for venting the developer conveyance path is located downstream of the first developer supply path in the conveyance direction of the first developer supply path and the first developer supply opening. It is characterized by being provided at a position above the uppermost part of the part.
According to a second aspect of the present invention, there is provided the developing device according to the first aspect, wherein the developer is transferred to the first developer agitating / conveying means downstream of the third developer agitating / conveying means in the developer conveying direction. 3. The developer carrier supplies toner to the latent image carrier through a third developer supply opening provided in a partition member with the first developer conveyance path downstream in the conveyance direction of the three developer conveyance path. It is characterized in that it is disposed within the development area width which is the width in the axial direction of the development area.
According to a third aspect of the present invention, there is provided the developing device according to the first or second aspect, wherein the first developer supply opening is disposed in the axial direction of the development region where the developer carrier supplies toner to the latent image carrier. It arrange | positions in the image development area width which is a width | variety.
According to a fourth aspect of the present invention, in the developing device according to any one of the first, second, and third aspects, the axial direction of the developing region where the developer carrying member supplies toner to the latent image carrying member through the ventilation opening. It is characterized in that it is disposed within the width of the development area which is the width of the above.
The invention of claim 5 comprises a latent image carrier, charging means for charging the latent image carrier, latent image forming means for forming an electrostatic latent image on the latent image carrier, An image forming apparatus having a developing unit for developing an electrostatic latent image into a toner image, wherein the developing unit of claim 1, 2, 3, or 4 is used as the developing unit. It is.

本発明では、第１現像剤搬送路を軸方向に第１現像剤供給用開口部まで搬送されてきた現像剤のうち嵩が第１現像剤供給用開口部の最下部の高さに達するものは、第１現像剤供給用開口部を介して下方の第３現像剤搬送路へこぼれ落ちる。
一方、第１現像剤供給用開口部の最下部の高さに達しない現像剤はさらに下流側へ搬送されながら現像剤担持体に供給されていくため、第１現像剤搬送路内の第１現像剤供給用開口部よりも下流側では、現像剤の嵩は第１現像剤供給用開口部の最下部よりも徐々に低くなっていく。第１現像剤搬送路の最下流部は行き止まりとなっているため最下流部で現像剤の嵩が高くなることもあるが、ある程度の高さになると第１現像剤攪拌搬送手段に逆らって現像剤が押し戻されて第１現像剤供給用開口部まで戻り、第１現像剤供給用開口部の最下部の高さに達するものは第１現像剤供給用開口部を介して下方の第３現像剤搬送路へこぼれ落ちる。これらにより、第１現像剤搬送路の第１現像剤供給用開口部よりも下流側では、現像剤の嵩は増え続けることはなく、第１現像剤供給用開口部の最下部近傍である勾配を持った平衡状態となる。通気用開口部を、第１現像剤供給用開口部の最上部より高い位置、すなわち、この平衡状態よりも高い位置に設けることで、通気用開口部が現像剤で塞がれて通気が不十分となる虞は少なく、第３現像剤搬送路と第１現像剤搬送路とで十分な通気を確保することができる。
このようにして、下方に配置される第３現像剤搬送路と、上方に配置され、空気を通過させるフィルタを設けた第１現像剤搬送路との間で十分な通気が確保する。そして、第３現像剤搬送路及びこれと連通する第２現像剤搬送路の空気を、第１現像剤搬送路のフィルタから排気する。よって、下方に配置される第３現像剤搬送路および第３現像剤搬送路と連通する第２現像剤搬送路で内圧が上昇しても、空気を通過させるフィルタを設けた上方の第１現像剤搬送路と十分な通気を確保することができ、現像装置全体の内圧上昇を抑制することができる。
なお、第１現像剤供給用開口部を第１現像剤搬送路最下点に設けても、搬送方向下流側に設けた通気用開口部により十分な通気をおこなうことが可能である。しかし、この場合は、第１現像剤供給用開口部で現像剤の大部分が下方の第３現像剤搬送路に落下してしまい、第１現像剤供給用開口部下流側では現像剤担持体への現像剤供給不足が発生しやすい。このような不具合を避けて、通気用開口部を第１現像剤供給用開口部よりも下流に設けるためには、第１現像剤搬送路を軸方向下流側に延ばすことが必要になり、現像装置が大型化してしまう。
本発明では、第１現像剤搬送路と第３現像剤搬送路との仕切り部材で第１現像剤搬送路最下点より上方に第１現像剤供給用開口部を設け、さらに、第１現像剤供給用開口部よりも下流で、第１現像剤供給用開口部の最上部よりも上方に通気用開口部を設けることで、第１現像剤供給用開口部よりも下流側でも現像剤供給不足を起こす虞なく、内圧上昇を抑制できる小型の現像装置を提供することができる。 In the present invention, the bulk of the developer transported in the axial direction to the first developer supply opening in the first developer transport path reaches the height of the lowermost portion of the first developer supply opening. Spills down to the third developer transport path below through the first developer supply opening.
On the other hand, the developer that does not reach the lowest height of the first developer supply opening is supplied to the developer carrying member while being further conveyed to the downstream side. On the downstream side of the developer supply opening, the bulk of the developer gradually becomes lower than the lowest part of the first developer supply opening. Since the most downstream portion of the first developer conveyance path is a dead end, the bulk of the developer may increase at the most downstream portion. However, when the height reaches a certain level, development is performed against the first developer agitating and conveying means. The developer is pushed back to return to the first developer supply opening, and reaches the lowermost height of the first developer supply opening through the first developer supply opening. Spills into the agent transport path. Thus, the developer volume does not continue to increase on the downstream side of the first developer supply opening in the first developer transport path, and the gradient is in the vicinity of the lowermost portion of the first developer supply opening. It will be in an equilibrium state with By providing the ventilation opening at a position higher than the uppermost portion of the first developer supply opening, that is, at a position higher than this equilibrium state, the ventilation opening is blocked by the developer and the ventilation is not performed. There is little possibility of becoming sufficient, and sufficient ventilation can be secured in the third developer transport path and the first developer transport path.
In this manner, sufficient ventilation is ensured between the third developer conveyance path disposed below and the first developer conveyance path disposed above and provided with a filter through which air passes. Then, the air in the third developer transport path and the second developer transport path communicating with the third developer transport path is exhausted from the filter in the first developer transport path. Therefore, even if the internal pressure rises in the third developer transport path disposed below and the second developer transport path communicating with the third developer transport path, the upper first development provided with a filter that allows air to pass therethrough. The agent conveying path and sufficient ventilation can be ensured, and an increase in the internal pressure of the entire developing device can be suppressed.
Even if the first developer supply opening is provided at the lowest point of the first developer conveyance path, sufficient ventilation can be performed by the ventilation opening provided on the downstream side in the conveyance direction. However, in this case, most of the developer falls to the third developer transport path below at the first developer supply opening, and the developer carrier on the downstream side of the first developer supply opening. Insufficient developer supply is likely to occur. In order to avoid such problems and to provide the ventilation opening downstream of the first developer supply opening, it is necessary to extend the first developer conveyance path to the downstream side in the axial direction. The device becomes large.
In the present invention, the first developer supply opening is provided above the lowest point of the first developer conveyance path in the partition member between the first developer conveyance path and the third developer conveyance path, and the first development is further performed. By providing an opening for ventilation downstream of the opening for supplying the developer and above the uppermost portion of the opening for supplying the first developer, the developer is supplied also downstream of the opening for supplying the first developer. It is possible to provide a small-sized developing device that can suppress an increase in internal pressure without causing a shortage.

以上、本発明によれば、現像剤の供給おこなう供給搬送路よりも下方に、回収をおこなう回収搬送路と攪拌をおこなう攪拌搬送路とを備えた現像装置及びこれを用いた画像形成装置において、現像装置内圧上昇によるトナー飛散を防止できる小型の装置を提供できるという優れた効果がある。   As described above, according to the present invention, in a developing device including a collection conveyance path for collecting and a stirring conveyance path for stirring below a supply conveyance path for supplying developer, and an image forming apparatus using the same. There is an excellent effect that it is possible to provide a small apparatus capable of preventing toner scattering due to an increase in the internal pressure of the developing device.

以下、本発明を画像形成装置に適用した一実施形態について説明する。図１は、本実施形態に係る画像形成装置の要部の概略構成図である。画像形成装置は、潜像担持体である感光体ドラム１００の周囲に、帯電装置２１、現像装置１、中間転写装置２３、クリーニング装置２８等が配設されている。また、これらの下方には露光装置２２が設けられている。また、中間転写装置２３の側方には２次転写装置２５と定着装置２７とが設けられている。   Hereinafter, an embodiment in which the present invention is applied to an image forming apparatus will be described. FIG. 1 is a schematic configuration diagram of a main part of the image forming apparatus according to the present embodiment. In the image forming apparatus, a charging device 21, a developing device 1, an intermediate transfer device 23, a cleaning device 28, and the like are disposed around a photosensitive drum 100 that is a latent image carrier. An exposure device 22 is provided below these. Further, a secondary transfer device 25 and a fixing device 27 are provided on the side of the intermediate transfer device 23.

感光体ドラム１００は、図中反時計回りに回転しながら、帯電装置２１で一様に帯電され、露光装置２２よりレーザーのような発光素子によって情報信号を露光されて静電潜像を形成される。感光体ドラム１００上の静電潜像は、現像装置１によりトナー像化され、形成されたトナー像は中間転写装置２３によって中間転写ベルト２４の上に転写される。中間転写ベルト２４上には、図示しない他の現像装置によるトナー像も転写可能であり、異なる色のトナーを重ねたカラー画像を作成することもできる。中間転写ベルト２４上のトナー像は２次転写装置２５によって転写紙２６の上に転写され、更に定着装置２７にて定着して永久画像を得る。感光体ドラム１００上の転写残トナーはクリーニング装置２８により除去され、感光体ドラム１００は次の画像形成に供される。   The photosensitive drum 100 is uniformly charged by the charging device 21 while rotating counterclockwise in the figure, and an information signal is exposed by a light emitting element such as a laser from the exposure device 22 to form an electrostatic latent image. The The electrostatic latent image on the photosensitive drum 100 is converted into a toner image by the developing device 1, and the formed toner image is transferred onto the intermediate transfer belt 24 by the intermediate transfer device 23. A toner image by another developing device (not shown) can be transferred onto the intermediate transfer belt 24, and a color image in which different color toners are superimposed can be created. The toner image on the intermediate transfer belt 24 is transferred onto the transfer paper 26 by the secondary transfer device 25 and further fixed by the fixing device 27 to obtain a permanent image. The transfer residual toner on the photosensitive drum 100 is removed by the cleaning device 28, and the photosensitive drum 100 is used for the next image formation.

図２は、現像装置の概略構成を示す断面図である。この現像装置１は、２成分現像剤を収容した現像容器２を備え、感光体ドラム１００と対面した現像容器２の開口部に、現像剤担持体としての現像スリーブ１１が感光体ドラム１００と所定の間隔を開けて回転自在に設置されている。現像スリーブ１１は非磁性材料の円筒形からなり、矢印の方向に回転する感光体ドラム１００に対して、対向部が同方向に移動する向きに回転する。現像スリーブ１１の内側には磁界発生手段のマグネットローラが、現像スリーブ１１の回転に対して非回転に配置されている。マグネットローラは５つの磁極Ｎ１、Ｓ１、Ｎ２、Ｎ３、Ｓ２を有している。現像スリーブ１１上方の現像容器２の部分には磁性部材の規制ブレード３０が取付けられ、この規制ブレード３０は、マグネットローラの鉛直方向最上点に略位置した磁極Ｓ２の近傍に向けて、現像スリーブ１１と非接触に配置されている。   FIG. 2 is a cross-sectional view illustrating a schematic configuration of the developing device. The developing device 1 includes a developing container 2 containing a two-component developer, and a developing sleeve 11 serving as a developer carrying member is formed with a predetermined distance from the photosensitive drum 100 at an opening of the developing container 2 facing the photosensitive drum 100. It is installed so as to be freely rotatable with an interval of. The developing sleeve 11 is made of a non-magnetic cylindrical material, and rotates in the direction in which the facing portion moves in the same direction with respect to the photosensitive drum 100 rotating in the direction of the arrow. Inside the developing sleeve 11, a magnet roller as a magnetic field generating means is arranged so as not to rotate with respect to the rotation of the developing sleeve 11. The magnet roller has five magnetic poles N1, S1, N2, N3, and S2. A magnetic member regulating blade 30 is attached to the portion of the developing container 2 above the developing sleeve 11, and the regulating blade 30 is directed toward the vicinity of the magnetic pole S <b> 2 that is substantially positioned at the uppermost point in the vertical direction of the magnet roller. And arranged in non-contact.

現像容器２内には第１現像剤攪拌搬送手段である供給スクリュー４、第２現像剤攪拌搬送手段である回収スクリュー６、第３現像剤攪拌搬送手段である攪拌スクリュー７をそれぞれ収容する供給搬送路２ａ、回収搬送路２ｂ、攪拌搬送路２ｃの３つの現像剤搬送路が設けられている。供給搬送路２ａと攪拌搬送路２ｃとは、斜め上下方向に配置されている。また、回収搬送路２ｂは、現像スリーブ１１の現像領域下流側で、攪拌搬送路２ｃと略水平な側方に配置されている。   In the developing container 2, a supply screw 4 serving as a first developer stirring and conveying unit, a recovery screw 6 serving as a second developer stirring and conveying unit, and a stirring screw 7 serving as a third developer stirring and conveying unit are accommodated. There are provided three developer transport paths: a path 2a, a recovery transport path 2b, and a stirring transport path 2c. The supply conveyance path 2a and the agitation conveyance path 2c are arranged obliquely in the vertical direction. Further, the collection conveyance path 2b is disposed on the downstream side of the developing region of the developing sleeve 11 and on a side substantially horizontal to the stirring conveyance path 2c.

現像容器２内に収容された２成分現像剤は、供給スクリュー４、回収スクリュー７、攪拌スクリュー６の撹拌、搬送により供給搬送路２ａ、回収搬送路２ｂ、攪拌搬送路２ｃを循環搬送されながら、供給搬送路２ａより現像スリーブ１１に供給される。現像スリーブ１１に供給された現像剤は、マグネットローラの磁極Ｎ２により現像スリーブ１１上に汲み上げられる。現像スリーブ１１の回転にともない、現像スリーブ１１上を磁極Ｓ２から磁極Ｎ１、磁極Ｎ１から磁極Ｓ１と搬送され、現像スリーブ１１と感光ドラム１００とが対向した現像領域にいたる。その搬送の途上で現像剤は、規制ブレード３０により磁極Ｓ２と共同して磁気的に層厚を規制され、現像スリーブ１１上に現像剤の薄層が形成される。現像スリーブ１１内の現像領域に位置されたマグネットローラの磁極Ｓ１は現像主極であり、現像領域に搬送された現像剤は、磁極Ｓ１によって穂立ちして感光ドラム１００の表面に接触し、感光ドラム１００の表面に形成された静電潜像を現像する。潜像を現像した現像剤は、現像スリーブ１１の回転にともない現像領域を通過し、搬送極Ｎ３を経て現像容器２内に戻され、磁極Ｎ２、Ｎ３の反発磁界により現像スリーブ１１から離脱し、回収スクリュー６により回収搬送路２ｂに回収される。   The two-component developer accommodated in the developing container 2 is circulated and conveyed through the supply conveyance path 2a, the collection conveyance path 2b, and the agitation conveyance path 2c by stirring and conveyance of the supply screw 4, the recovery screw 7 and the stirring screw 6. The toner is supplied to the developing sleeve 11 from the supply conveyance path 2a. The developer supplied to the developing sleeve 11 is pumped onto the developing sleeve 11 by the magnetic pole N2 of the magnet roller. As the developing sleeve 11 rotates, the developing sleeve 11 is conveyed from the magnetic pole S2 to the magnetic pole N1 and from the magnetic pole N1 to the magnetic pole S1, and reaches the developing area where the developing sleeve 11 and the photosensitive drum 100 face each other. During the conveyance, the developer is magnetically regulated by the regulating blade 30 in cooperation with the magnetic pole S2, and a thin layer of developer is formed on the developing sleeve 11. The magnetic pole S1 of the magnet roller located in the developing area in the developing sleeve 11 is a developing main pole, and the developer conveyed to the developing area rises by the magnetic pole S1 and comes into contact with the surface of the photosensitive drum 100, and is exposed to light. The electrostatic latent image formed on the surface of the drum 100 is developed. The developer that has developed the latent image passes through the developing region as the developing sleeve 11 rotates, returns to the developing container 2 through the transport pole N3, and is separated from the developing sleeve 11 by the repulsive magnetic field of the magnetic poles N2 and N3. It is collected in the collection conveyance path 2b by the collection screw 6.

供給搬送路２ａと斜め下方の回収搬送路２ｂとは第１仕切り部材３１によって仕切られている。   The supply conveyance path 2 a and the collection conveyance path 2 b obliquely below are partitioned by a first partition member 31.

回収搬送路２ｂと側方に配置される攪拌搬送路２ｃとは第２仕切り部材３２によって仕切られているが、回収搬送路２ｂの回収スクリュー６による搬送方向下流部には、回収された現像剤を攪拌搬送路２ｃに供給するための現像剤供給用開口部が設けられている。図３は、回収スクリュー６による搬送方向下流部における回収搬送路２ｂと攪拌搬送路２ｃとの断面図であり、回収搬送路２ｂと攪拌搬送路２ｃとを連通する開口部２ｄが設けられている。   The collection conveyance path 2b and the agitating conveyance path 2c arranged on the side are partitioned by the second partition member 32, but the collected developer is located downstream in the conveyance direction by the collection screw 6 of the collection conveyance path 2b. Is provided with a developer supply opening for supplying the toner to the agitating and conveying path 2c. FIG. 3 is a cross-sectional view of the collection conveyance path 2b and the agitation conveyance path 2c at the downstream portion in the conveyance direction by the collection screw 6, and an opening 2d that connects the collection conveyance path 2b and the agitation conveyance path 2c is provided. .

また、供給搬送路２ａと斜め下方に配置されるの攪拌搬送路２ｃとは第３仕切り部材３３により仕切られているが、供給搬送路２ａの供給スクリュー４による搬送方向上流部と下流部には、現像剤を供給するための現像剤供給用開口部が設けられている。図４は、供給スクリュー７による搬送方向上流部における現像装置１の断面図であり、第３仕切り部材３３に攪拌搬送路２ｃと供給搬送路２ａとを連通する開口部２ｅが設けられている。また、図５は、供給スクリュー７による搬送方向下流部における現像装置１の断面図であり、第３仕切り部材３３に攪拌搬送路２ｃと供給搬送路２ａとを連通する開口部２ｆが設けられている。   Further, the supply conveyance path 2a and the stirring conveyance path 2c arranged obliquely below are partitioned by the third partition member 33, but in the upstream and downstream portions in the conveyance direction by the supply screw 4 of the supply conveyance path 2a. A developer supply opening for supplying the developer is provided. FIG. 4 is a cross-sectional view of the developing device 1 at the upstream portion in the conveyance direction by the supply screw 7, and the third partition member 33 is provided with an opening 2 e that communicates the agitation conveyance path 2 c and the supply conveyance path 2 a. FIG. 5 is a cross-sectional view of the developing device 1 at the downstream portion in the conveyance direction by the supply screw 7. The third partition member 33 is provided with an opening 2 f that communicates the agitation conveyance path 2 c and the supply conveyance path 2 a. Yes.

次に、３つの現像剤搬送路内での現像剤の循環について説明する。
図６は、現像装置１内での現像剤の流れの模式図である。図６中の各矢印は現像剤の移動方向を示している。攪拌搬送路２ｃから現像剤の供給を受けた供給搬送路２ａでは、現像スリーブ１１に現像剤を供給しながら、供給スクリュー４の搬送方向下流側に現像剤を搬送する。そして、現像スリーブ１１に供給されずに供給搬送路２ａの搬送方向下流部まで搬送された余剰現像剤は第３仕切り部材３３に設けられた第１現像剤供給用開口部としての開口部２ｆより攪拌搬送路２ｃに供給される。
また、回収スクリュー６により現像スリーブ１１から回収搬送路２ｂに回収され、供給搬送路２ａの現像剤と同方向に搬送方向下流部まで搬送された回収現像剤は第２仕切り部材３２に設けられた第２現像剤供給用開口部としての開口部２ｄより攪拌搬送路２ｃに供給される。
攪拌搬送路２ｃでは、攪拌スクリュー７により供給された余剰現像剤と回収現像剤とを攪拌し、回収搬送路２ｂ及び供給搬送路２ａの現像剤と逆方向に搬送する。そして、攪拌搬送路２ｃの搬送方向下流側に搬送された現像剤は、第３仕切り部材３３に設けられた第３現像剤供給用開口部としての開口部２ｅより供給搬送路２ａの搬送方向上流部に供給される。 Next, the circulation of the developer in the three developer conveyance paths will be described.
FIG. 6 is a schematic diagram of the developer flow in the developing device 1. Each arrow in FIG. 6 indicates the moving direction of the developer. In the supply conveyance path 2 a that receives the developer supplied from the agitation conveyance path 2 c, the developer is conveyed downstream in the conveyance direction of the supply screw 4 while supplying the developer to the developing sleeve 11. The surplus developer conveyed to the downstream side in the conveyance direction of the supply conveyance path 2 a without being supplied to the developing sleeve 11 is from an opening 2 f as a first developer supply opening provided in the third partition member 33. It is supplied to the agitation transport path 2c.
Further, the recovered developer that is recovered from the developing sleeve 11 to the recovery transport path 2b by the recovery screw 6 and transported to the downstream portion in the transport direction in the same direction as the developer in the supply transport path 2a is provided in the second partition member 32. The developer is supplied to the stirring and conveying path 2c from the opening 2d as the second developer supply opening.
In the agitating and conveying path 2c, the surplus developer and the recovered developer supplied by the agitating screw 7 are agitated and conveyed in the opposite direction to the developer in the collecting and conveying path 2b and the supplying and conveying path 2a. The developer conveyed downstream in the conveyance direction of the agitation conveyance path 2 c is upstream in the conveyance direction of the supply conveyance path 2 a from the opening 2 e serving as the third developer supply opening provided in the third partition member 33. Supplied to the department.

また、攪拌搬送路２ｃの下方には、トナー濃度センサ（不図示）が設けられ、センサ出力により不図示のトナー補給制御装置を作動し、トナー収容部（不図示）からトナー補給を行っている。攪拌搬送路２ｃでは攪拌スクリュー７によって、必要に応じてトナー補給口３から補給されるトナーを、回収現像剤及び余剰現像剤と攪拌しながら搬送方向下流側へ搬送する。トナーを補給する際には攪拌スクリュー７の上流にて補給すると補給から現像までの攪拌時間を長くとれるので良い。   A toner concentration sensor (not shown) is provided below the agitation transport path 2c, and a toner supply control device (not shown) is operated by the sensor output to supply toner from a toner container (not shown). . In the agitating and conveying path 2c, the toner replenished from the toner replenishing port 3 as necessary is conveyed by the agitating screw 7 to the downstream side in the conveying direction while being agitated with the collected developer and the surplus developer. When replenishing toner, replenishing upstream of the agitation screw 7 can increase the agitation time from replenishment to development.

このように現像装置１では、供給搬送路２ａと回収搬送路２ｂとを備え、現像剤の供給と回収とを異なる現像剤搬送路で行うので、現像済みの現像剤が供給搬送路２ａに混入することがない。よって、供給搬送路２ａの搬送方向下流側ほど現像スリーブ１１に供給される現像剤のトナー濃度が低下することを防止することができる。また、回収搬送路２ｂと攪拌搬送路２ｃとを備え、現像剤の回収と攪拌とを異なる現像剤搬送路で行うので、現像済みの現像剤が攪拌の途中に落ちることがない。よって、十分に攪拌がなされた現像剤が供給搬送路２ａに供給されるため、供給搬送路２ａに供給されるの現像剤が攪拌不足となることを防止することができる。このように、供給搬送路２ａ内の現像剤のトナー濃度が低下することを防止し、供給搬送路２ａ内の現像剤が攪拌不足となることを防止することができるので現像時の画像濃度を一定にすることができる。   As described above, the developing device 1 includes the supply conveyance path 2a and the collection conveyance path 2b, and the developer is supplied and collected in different developer conveyance paths, so that the developed developer is mixed into the supply conveyance path 2a. There is nothing to do. Therefore, it is possible to prevent the toner concentration of the developer supplied to the developing sleeve 11 from decreasing toward the downstream side of the supply conveyance path 2a in the conveyance direction. Further, since the recovery conveyance path 2b and the agitation conveyance path 2c are provided and the developer is collected and stirred in different developer conveyance paths, the developed developer does not fall during the agitation. Therefore, since the sufficiently agitated developer is supplied to the supply conveyance path 2a, it is possible to prevent the developer supplied to the supply conveyance path 2a from being insufficiently agitated. In this way, the toner density of the developer in the supply conveyance path 2a can be prevented from decreasing, and the developer in the supply conveyance path 2a can be prevented from being insufficiently stirred, so the image density during development can be reduced. Can be constant.

また、図４に示す供給搬送路２ａの搬送方向上流部では、斜め下方に配置される攪拌搬送路２ｃから上方の供給搬送路２ａへ現像剤を供給するものである。この現像剤の受け渡しは、攪拌スクリュー７の回転で現像剤を押し込むことにより、現像剤を盛り上がらせて開口部２ｅより現像剤を溢れさせて供給搬送路２ａに現像剤を供給するものである。このような現像剤の移動は、現像剤に対してストレスを与えることになり、現像剤の寿命低下の一因となる。現像装置１では、供給搬送路２ａを攪拌搬送路２ｃの斜め上方になるように配置することにより、供給搬送路２ａを攪拌搬送路２ｃの垂直上方に設け、現像剤を持ち上げるものに比べて、上方への現像剤の移動における現像剤のストレスを軽減することができる。   Further, in the upstream portion in the conveyance direction of the supply conveyance path 2a shown in FIG. 4, the developer is supplied from the stirring conveyance path 2c disposed obliquely downward to the upper supply conveyance path 2a. In the delivery of the developer, the developer is pushed up by the rotation of the stirring screw 7 so that the developer is raised and overflows from the opening 2e to supply the developer to the supply conveyance path 2a. Such movement of the developer gives stress to the developer and contributes to a decrease in the life of the developer. In the developing device 1, the supply conveyance path 2a is disposed so as to be obliquely above the agitation conveyance path 2c, so that the supply conveyance path 2a is provided vertically above the agitation conveyance path 2c, and the developer is lifted, It is possible to reduce the developer stress in the upward movement of the developer.

次に、本発明の特徴部について説明する。
図５に示す供給スクリュー７による搬送方向下流部では、上方に配置される供給搬送路２ａから斜め下方に配置される攪拌搬送路２ｃへ現像剤を供給するために、供給搬送路２ａと攪拌搬送路２ｃとを連通する開口部２ｆが設けられている。ここで、攪拌搬送路２ｃと供給搬送路２ａとを仕切る第３仕切り部材３３は、供給搬送路２ａの最下点から上方に延伸しており、開口部２ｆは最下点よりも上方の位置に設けられている。また、図７は、供給スクリュー７による搬送方向最下流部における現像装置１の断面図である。図７に示すように、供給スクリュー７による搬送方向に関して開口部２ｆよりも下流部には、第３仕切り部材３３に攪拌搬送路２ｃと供給搬送路２ａとを連通する開口部２ｇが設けられている。また、開口部２ｇは開口部２ｆの最上部よりも上方に設けられている。 Next, features of the present invention will be described.
In the downstream portion in the conveyance direction by the supply screw 7 shown in FIG. 5, the supply conveyance path 2a and the agitation conveyance are performed in order to supply the developer from the supply conveyance path 2a disposed above to the agitation conveyance path 2c disposed obliquely below. An opening 2f that communicates with the path 2c is provided. Here, the third partition member 33 that partitions the stirring conveyance path 2c and the supply conveyance path 2a extends upward from the lowest point of the supply conveyance path 2a, and the opening 2f is located above the lowest point. Is provided. FIG. 7 is a cross-sectional view of the developing device 1 at the most downstream portion in the conveyance direction by the supply screw 7. As shown in FIG. 7, an opening 2 g that communicates the stirring and conveying path 2 c and the supply and conveying path 2 a with the third partition member 33 is provided downstream of the opening 2 f in the conveying direction by the supply screw 7. Yes. The opening 2g is provided above the top of the opening 2f.

図８は、供給搬送路２ａに設けた開口部と現像剤の嵩の変化を示す説明図である。開口部２ｆ、２ｇを有する供給搬送路２ａでは、供給スクリュー７により供給搬送路２ａを軸方向に開口部２ｆまで搬送されてきた現像剤のうち嵩が開口部２ｆの最下部の高さに達するものは、開口部２ｆを介して下方の攪拌搬送路２ｃへこぼれ落ちる。一方、開口部２ｆの最下部の高さに達しない現像剤は、供給スクリュー７によりさらに下流側へ搬送されながら現像スリーブ１１に供給される。そこで、供給搬送路２ａ内の開口部２ｆよりも下流側では、現像剤の嵩は開口部２ｆの最下部よりも徐々に低くなっていく。供給搬送路２ａの最下流部は行き止まりとなっているため最下流部で現像剤の嵩が高くなることもあるが、ある程度の高さになると供給スクリュー７に逆らって現像剤が押し戻されて開口部２ｆまで戻り、開口部２ｆの最下部の高さに達するものは開口部２ｆを介して下方の攪拌搬送路２ｃへこぼれ落ちる。これらにより、供給搬送路２ａの開口部２ｆよりも下流側では、現像剤の嵩は増え続けることはなく、開口部２ｆの最下部近傍である勾配を持った平衡状態となる。開口部２ｇを、開口部２ｆの最上部より高い位置、すなわち、この平衡状態よりも高い位置に設けることで、開口部２ｆが現像剤で塞がれて通気が不十分となる虞は少なく、攪拌搬送路２ｃと供給搬送路２ａとで十分な通気を確保することができる。すなわち、開口部２ｇは、供給搬送路２と攪拌搬送路２ｃとの間の現像剤供給用開口部としての機能ではなく、供給搬送路２と攪拌搬送路２ｃとの間で十分な通気を確保するための通気用開口部としての機能を果たすものである。このような通気用の開口部２ｇを設けることで、下方に配置される攪拌搬送路２ｃおよび攪拌搬送路２ｃと連通する回収搬送路２ｂで内圧が上昇しても、空気を通過させるフィルタを設けた上方の供給搬送路２ａと十分な通気を確保することができ、現像装置１全体の内圧上昇を抑制することができる。   FIG. 8 is an explanatory diagram showing changes in the opening provided in the supply conveyance path 2a and the bulk of the developer. In the supply conveyance path 2a having the openings 2f and 2g, the bulk of the developer conveyed in the axial direction through the supply conveyance path 2a to the opening 2f by the supply screw 7 reaches the lowest height of the opening 2f. Things fall down to the lower agitating and conveying path 2c through the opening 2f. On the other hand, the developer that does not reach the lowermost height of the opening 2 f is supplied to the developing sleeve 11 while being conveyed further downstream by the supply screw 7. Therefore, on the downstream side of the opening 2f in the supply conveyance path 2a, the volume of the developer gradually becomes lower than the lowest part of the opening 2f. Since the most downstream portion of the supply conveyance path 2a is a dead end, the bulk of the developer may increase in the most downstream portion. However, when the height reaches a certain level, the developer is pushed back against the supply screw 7 and opened. What returns to the portion 2f and reaches the lowest height of the opening 2f spills down to the lower stirring and conveying path 2c through the opening 2f. Thus, on the downstream side of the opening 2f of the supply conveyance path 2a, the bulk of the developer does not continue to increase, and an equilibrium state with a gradient near the bottom of the opening 2f is obtained. By providing the opening 2g at a position higher than the uppermost part of the opening 2f, that is, a position higher than this equilibrium state, there is little possibility that the opening 2f is blocked by the developer and the ventilation becomes insufficient. Sufficient ventilation can be ensured by the stirring conveyance path 2c and the supply conveyance path 2a. That is, the opening 2g does not function as a developer supply opening between the supply conveyance path 2 and the agitation conveyance path 2c, and ensures sufficient ventilation between the supply conveyance path 2 and the agitation conveyance path 2c. It fulfills the function as an opening for ventilation. By providing such an opening 2g for ventilation, a filter that allows air to pass therethrough is provided even if the internal pressure rises in the agitation conveyance path 2c disposed below and the recovery conveyance path 2b communicating with the agitation conveyance path 2c. Further, it is possible to ensure sufficient ventilation with the upper supply conveyance path 2a, and it is possible to suppress an increase in internal pressure of the entire developing device 1.

なお、供給搬送路２ａ下流部の現像剤供給用開口部を供給搬送路２ａ最下点に設けても、搬送方向下流側に設けた通気用開口部により十分な通気をおこなうことが可能である。しかし、この場合は、現像剤供給用開口部で現像剤の大部分が下方の攪拌搬送路２ｃに落下してしまい、現像剤供給用開口部下流側では現像スリーブ１１への現像剤供給不足が発生しやすい。このような不具合を避けて、通気用開口部を像剤供給用開口部よりも下流に設けるためには、供給搬送路２ａを軸方向下流側に延ばすことが必要になり、現像装置が大型化してしまう。   Even if the developer supply opening on the downstream side of the supply conveyance path 2a is provided at the lowest point of the supply conveyance path 2a, the ventilation opening provided on the downstream side in the conveyance direction can provide sufficient ventilation. . However, in this case, most of the developer falls to the lower agitating / conveying path 2c at the developer supply opening, and there is insufficient developer supply to the developing sleeve 11 on the downstream side of the developer supply opening. Likely to happen. In order to avoid such problems and to provide the ventilation opening downstream of the image agent supply opening, it is necessary to extend the supply conveyance path 2a to the downstream side in the axial direction, which increases the size of the developing device. End up.

本実施形態の現像装置１では、供給搬送路２ａと攪拌搬送路２ｃとの第３仕切り部材３３で、供給搬送路２ａ最下点から上方に延伸した部分に、上記開口部２ｆ、２ｇを設けることで、開口部２ｆ下流側でも現像剤供給不足を起こす虞なく、内圧上昇を抑制できる小型の現像装置を提供することができる。   In the developing device 1 of the present embodiment, the openings 2f and 2g are provided in a portion extending upward from the lowest point of the supply conveyance path 2a by the third partition member 33 of the supply conveyance path 2a and the agitation conveyance path 2c. As a result, it is possible to provide a small-sized developing device that can suppress an increase in internal pressure without fear of insufficient supply of the developer even on the downstream side of the opening 2f.

また、現像装置１では、攪拌搬送路２ｃの下流部で供給搬送路２ｃに現像剤を供給する開口部２ｅを、現像スリーブ１１が感光体ドラム１００にトナーを供給する現像領域の軸線方向の幅である現像領域幅内に配置する。これにより、開口部２ｅを現像領域幅よりも外側に設けたものに比べて、供給搬送路２ａおよび攪拌搬送路２ｃが短くなる。そこで、供給搬送路２ａおよび攪拌搬送路２ｃが占めるスペースを小さくすることができ、装置の小型化を図ることができる。   Further, in the developing device 1, an opening 2e that supplies the developer to the supply conveyance path 2c in the downstream portion of the stirring conveyance path 2c, and the width in the axial direction of the development area in which the developing sleeve 11 supplies toner to the photosensitive drum 100 are provided. It is arranged within the development area width. As a result, the supply conveyance path 2a and the agitation conveyance path 2c are shorter than those in which the opening 2e is provided outside the development region width. Therefore, the space occupied by the supply conveyance path 2a and the stirring conveyance path 2c can be reduced, and the apparatus can be downsized.

また、供給搬送路２ａの下流部で攪拌搬送路２ｃに現像剤を供給する開口部２ｆを現像領域幅内に配置する。これにより、開口部２ｆを現像領域幅よりも外側に設けたものに比べて、供給搬送路２ａおよび攪拌搬送路２ｃが短くなる。そこで、供給搬送路２ａおよび攪拌搬送路２ｃが占めるスペースを小さくすることができ、装置の小型化を図ることができる。   In addition, an opening 2f for supplying the developer to the stirring and conveying path 2c is disposed within the developing region width at a downstream portion of the supply and conveying path 2a. Thereby, the supply conveyance path 2a and the agitation conveyance path 2c are shorter than those in which the opening 2f is provided outside the development region width. Therefore, the space occupied by the supply conveyance path 2a and the stirring conveyance path 2c can be reduced, and the apparatus can be downsized.

また、供給搬送路２ａの最下流部で攪拌搬送路２ｃと通気をおこなう開口部２ｇを現像領域幅内に配置する。これにより、開口部２ｇを現像領域幅よりも外側に設けたものに比べて、供給搬送路２ａおよび攪拌搬送路２ｃが短くなる。そこで、供給搬送路２ａおよび攪拌搬送路２ｃが占めるスペースを小さくすることができ、装置の小型化を図ることができる。   In addition, an opening 2g that ventilates with the agitation conveyance path 2c at the most downstream portion of the supply conveyance path 2a is disposed within the width of the development area. Thereby, the supply conveyance path 2a and the agitation conveyance path 2c are shorter than those in which the opening 2g is provided outside the width of the development region. Therefore, the space occupied by the supply conveyance path 2a and the stirring conveyance path 2c can be reduced, and the apparatus can be downsized.

なお、本実施形態の現像装置１では、供給搬送路２ａと攪拌搬送路２ｃとは、斜め上下方向、回収搬送路２ｂと攪拌搬送路２ｃとは略水平に配置されるものであるが、回収搬送路２ｂと攪拌搬送路２ｃとが供給搬送路２ａより下方に配置される構成のものであれば、これに限らない。例えば、供給搬送路２ａの真下に攪拌搬送路２ｃが配置される、特許文献１の現像装置にも適用できる。この場合も、従来の現像剤供給用開口部では、開口部が現像剤で塞がれて、上下に配置される供給搬送路と攪拌搬送路の間で十分な通気が確保できない。上方に配置される供給搬送路２ａ下流部に、現像剤供給用記開口部としての開口部２ｆと、通気用開口部としての開口部２ｇとを上述のように配置することで、空気を通過させるフィルタを設けた上方の供給搬送路２ａと十分な通気を確保することができ、現像装置全体の内圧上昇を抑制することができる。   In the developing device 1 of the present embodiment, the supply conveyance path 2a and the agitation conveyance path 2c are arranged obliquely in the vertical direction, and the collection conveyance path 2b and the agitation conveyance path 2c are arranged substantially horizontally. The present invention is not limited to this as long as the conveyance path 2b and the stirring conveyance path 2c are arranged below the supply conveyance path 2a. For example, the present invention can also be applied to the developing device of Patent Document 1 in which the agitation conveyance path 2c is disposed directly below the supply conveyance path 2a. Also in this case, in the conventional developer supply opening, the opening is blocked with the developer, and sufficient ventilation cannot be ensured between the supply conveyance path and the agitation conveyance path arranged above and below. By arranging the opening 2f as the developer supply opening and the opening 2g as the ventilation opening as described above in the downstream of the supply conveyance path 2a arranged above, the air passes. It is possible to ensure sufficient ventilation with the upper supply conveyance path 2a provided with the filter to suppress the increase in the internal pressure of the entire developing device.

以上、本実施形態の現像装置１は、トナーと磁性キャリアとからなる現像剤を軸線方向に攪拌搬送して現像スリーブ１１に供給する第１現像剤攪拌搬送手段としての供給スクリュー４を有する第１現像剤搬送路としての供給搬送路２ａと、供給スクリュー４よりも下方に配置され潜像担持体としての感光体ドラム１００との対向部通過後の現像スリーブ１１から現像剤を回収して、供給スクリュー４と同方向に搬送する第２現像剤攪拌搬送手段としての回収スクリュー６を有する第２現像剤搬送路としての回収搬送路２ｂと、供給スクリュー４よりも下方に配置され、供給スクリュー４により現像スリーブ１１に供給されずに供給搬送路２ａの下流部まで搬送された現像剤と、回収スクリュー６により現像スリーブ１１から回収され回収搬送路２ｂの搬送方向の下流部まで搬送された現像剤との供給を受け、供給スクリュー４と逆方向に現像剤を攪拌搬送して下流側で供給スクリュー４に受け渡す第３現像剤攪拌搬送手段としての攪拌スクリュー７を有する第３現像剤搬送路としての攪拌搬送路２ｃとを有する。供給搬送路２ａ、回収搬送路２ｂ、攪拌搬送路２ｃは、それぞれ第１仕切り部材３１、第２仕切り部材３２、第３仕切り部材３３により仕切られる。この現像装置１において、 供給搬送路２ａの上方にトナーを通過させずに空気を通過させるフィルタを設ける。また、供給搬送路２ａと攪拌搬送路２ｃとを仕切る第３仕切り部材３３は、供給搬送路２ａ最下点より上方に延伸している。供給搬送路２ａの搬送方向下流部から攪拌搬送路２ｃに現像剤を供給するための第１現像剤供給用開口部として、第３仕切り部材３３の供給搬送路２ａ最下点より上方に開口部２ｆを設ける。さらに、供給搬送路２ａと攪拌搬送路２ｃとを通気するための通気用開口部として、開口部２ｆより供給スクリュー４の搬送方向下流で、且つ、開口部２ｆの最上部よりも上方の第３仕切り部材３３に開口部２ｇを設ける。これにより、開口部２ｇにより、攪拌搬送路２ｃとフィルタを設けた供給搬送路２ａとの間で十分な通気が確保する。そして、攪拌搬送路２ｃ及びこれと連通する回収搬送路２ｂの空気を供給搬送路２ａを介してフィルタから排気することにより、攪拌搬送路２ｃ及び回収搬送路２ｂの内圧上昇を抑制できる。
また、攪拌搬送路２ｃの下流部で供給搬送路２ｃに現像剤を供給する開口部２ｅを、現像スリーブ１１が感光体ドラム１００にトナーを供給する現像領域の軸線方向の幅である現像領域幅内に配置する。これにより、開口部２ｅを現像領域幅よりも外側に設けたものに比べて、供給搬送路２ａおよび攪拌搬送路２ｃが短くなり、装置の小型化を図ることができる。
また、供給搬送路２ａの下流部で攪拌搬送路２ｃに現像剤を供給する開口部２ｆを現像領域幅内に配置する。これにより、開口部２ｆを現像領域幅よりも外側に設けたものに比べて、供給搬送路２ａおよび攪拌搬送路２ｃが短くなり、装置の小型化を図ることができる。
また、供給搬送路２ａの最下流部で攪拌搬送路２ｃと通気をおこなう開口部２ｇを現像領域幅内に配置する。これにより、開口部２ｇを現像領域幅よりも外側に設けたものに比べて、供給搬送路２ａおよび攪拌搬送路２ｃが短くなり、装置の小型化を図ることができる。 As described above, the developing device 1 of the present embodiment has the first supply screw 4 as the first developer agitating / conveying means that agitates and conveys the developer composed of the toner and the magnetic carrier in the axial direction and supplies the developer to the developing sleeve 11. The developer is collected from the developing sleeve 11 after passing through the facing portion between the supply conveyance path 2a as the developer conveyance path and the photosensitive drum 100 as the latent image carrier disposed below the supply screw 4 and supplied. A recovery conveyance path 2b as a second developer conveyance path having a collection screw 6 as a second developer agitating and conveyance means that conveys in the same direction as the screw 4 and a supply screw 4 are arranged below the supply screw 4. The developer that has not been supplied to the developing sleeve 11 and has been transported to the downstream portion of the supply transport path 2a, and is recovered from the developing sleeve 11 by the recovery screw 6 and recovered and transported. As a third developer agitating and conveying means that receives the developer conveyed to the downstream portion in the conveying direction of 2b, agitates and conveys the developer in the direction opposite to the supply screw 4 and delivers it to the supply screw 4 on the downstream side And a stirring / conveying path 2c as a third developer conveying path having the agitating screw 7. The supply conveyance path 2a, the collection conveyance path 2b, and the agitation conveyance path 2c are partitioned by a first partition member 31, a second partition member 32, and a third partition member 33, respectively. In the developing device 1, a filter that allows air to pass therethrough is provided above the supply conveyance path 2a. Moreover, the 3rd partition member 33 which partitions off the supply conveyance path 2a and the stirring conveyance path 2c is extended upwards from the supply conveyance path 2a lowest point. As a first developer supply opening for supplying the developer from the downstream side in the conveyance direction of the supply conveyance path 2a to the agitation conveyance path 2c, an opening is provided above the lowest point of the supply conveyance path 2a of the third partition member 33. 2f is provided. Furthermore, as a ventilation opening for ventilating the supply conveyance path 2a and the agitation conveyance path 2c, a third downstream of the opening 2f in the conveyance direction of the supply screw 4 and above the uppermost part of the opening 2f. An opening 2 g is provided in the partition member 33. Thereby, sufficient ventilation is ensured by the opening part 2g between the stirring conveyance path 2c and the supply conveyance path 2a provided with the filter. And the internal pressure rise of the stirring conveyance path 2c and the collection conveyance path 2b can be suppressed by exhausting the air in the collection conveyance path 2b communicating with the stirring conveyance path 2c from the filter via the supply conveyance path 2a.
Further, an opening 2e that supplies the developer to the supply conveyance path 2c in the downstream portion of the agitation conveyance path 2c, and a development area width that is the width in the axial direction of the development area where the developing sleeve 11 supplies toner to the photosensitive drum 100. Place in. As a result, the supply conveyance path 2a and the agitation conveyance path 2c are shortened as compared with the case where the opening 2e is provided outside the width of the development area, and the apparatus can be downsized.
In addition, an opening 2f for supplying the developer to the stirring and conveying path 2c is disposed within the developing region width at a downstream portion of the supply and conveying path 2a. As a result, the supply conveyance path 2a and the agitation conveyance path 2c are shortened compared to those in which the opening 2f is provided outside the width of the development region, and the apparatus can be downsized.
In addition, an opening 2g that ventilates with the agitation conveyance path 2c at the most downstream portion of the supply conveyance path 2a is disposed within the width of the development area. As a result, the supply conveyance path 2a and the agitation conveyance path 2c are shortened compared with the case where the opening 2g is provided outside the width of the development area, and the apparatus can be downsized.

本実施形態に係る画像形成装置の要部の概略構成図。1 is a schematic configuration diagram of a main part of an image forming apparatus according to an embodiment. 現像装置の概略構成を示す断面図。Sectional drawing which shows schematic structure of a developing device. 回収搬送路の搬送方向下流部における回収搬送路と攪拌搬送路との断面図。Sectional drawing of the collection conveyance path and the stirring conveyance path in the conveyance direction downstream part of a collection conveyance path. 現像装置の供給搬送路の搬送方向上流部における断面図。Sectional drawing in the conveyance direction upstream part of the supply conveyance path of a developing device. 現像装置の供給搬送路の搬送方向下流部における断面図。Sectional drawing in the conveyance direction downstream part of the supply conveyance path of a developing device. 現像装置内における現像剤の流れの模式図。FIG. 6 is a schematic diagram of a developer flow in the developing device. 現像装置の供給搬送路の搬送方向最下流部における断面図。Sectional drawing in the conveyance direction most downstream part of the supply conveyance path of a developing device. 供給搬送路に設けた開口部と現像剤の嵩の変化を示す説明図。Explanatory drawing which shows the change of the opening part provided in the supply conveyance path, and the volume of a developing agent.

符号の説明Explanation of symbols

１ 現像装置
２ 現像容器
２ａ 供給搬送路（第１現像剤搬送路）
２ｂ 回収搬送路（第２現像剤搬送路）
２ｃ 攪拌搬送路（第３現像剤搬送路）
２ｄ 開口部（第２現像剤供給用開口部）
２ｅ 開口部（第３現像剤供給用開口部）
２ｆ 開口部（第１現像剤供給用開口部）
２ｇ 開口部（通気用開口部）
３ トナー補給口
４ 供給スクリュー（第１現像剤攪拌搬送手段）
５ フィルタ
６ 回収スクリュー（第２現像剤攪拌搬送手段）
７ 攪拌スクリュー（第３現像剤攪拌搬送手段）
１０ 現像剤
１１ 現像スリーブ
２１ 帯電装置
２２ 露光装置
２３ 中間転写装置
２４ 中間転写ベルト
２５ ２次転写装置
２６ 転写紙
２７ 定着装置
２８ クリーニング装置
３０ 規制ブレード
３１ 第１仕切り部材
３２ 第２仕切り部材
３３ 第３仕切り部材
１００ 感光体ドラム DESCRIPTION OF SYMBOLS 1 Developer 2 Developer container 2a Supply conveyance path (1st developer conveyance path)
2b Collection transport path (second developer transport path)
2c Agitation conveyance path (third developer conveyance path)
2d opening (second developer supply opening)
2e Opening (third developer supply opening)
2f opening (first developer supply opening)
2g opening (ventilation opening)
3 Toner replenishment port 4 Supply screw (first developer stirring and conveying means)
5 Filter 6 Recovery screw (second developer stirring and conveying means)
7 Stirring screw (third developer stirring and conveying means)
DESCRIPTION OF SYMBOLS 10 Developer 11 Developing sleeve 21 Charging device 22 Exposure device 23 Intermediate transfer device 24 Intermediate transfer belt 25 Secondary transfer device 26 Transfer paper 27 Fixing device 28 Cleaning device 30 Regulator blade
31 1st partition member 32 2nd partition member 33 3rd partition member 100 Photosensitive drum

Claims (5)

トナーと磁性キャリアとからなる現像剤を担持して回転により潜像担持体との対向部まで搬送する現像剤担持体と、
該現像剤担持体の軸線方向に沿って現像剤を攪拌搬送して該現像剤担持体に供給する第１現像剤攪拌搬送手段を有する第１現像剤搬送路と、
該第１現像剤攪拌搬送手段よりも下方に配置され該潜像担持体との対向部通過後の該現像剤担持体から現像剤を回収して、該第１現像剤攪拌搬送手段と同方向に搬送する第２現像剤攪拌搬送手段を有する第２現像剤搬送路と、
該第１現像剤攪拌搬送手段よりも下方に配置され、該第１現像剤攪拌搬送手段により該現像剤担持体に供給されずに該第１現像剤搬送路の搬送方向下流部まで搬送された現像剤と、該第２現像剤攪拌搬送手段により該現像剤担持体から回収され該第２現像剤搬送路の搬送方向下流部まで搬送された現像剤との供給を受け、該第１現像剤攪拌搬送手段と逆方向に現像剤を攪拌搬送して下流側で該第１現像剤攪拌搬送手段に受け渡す第３現像剤攪拌搬送手段を有する第３現像剤搬送路とを有し、
該第１現像剤搬送路、該第２現像剤搬送路及び該第３現像剤搬送路は仕切り部材により仕切られる現像装置において、
トナーを通過させずに空気を通過させるフィルタを上記第１現像剤搬送路の上方に設け、
該第１現像剤搬送路と上記第３現像剤搬送路とを仕切る仕切り部材は該第１現像剤搬送路最下点より上方へ延伸したものであり、
該第１現像剤搬送路の搬送方向下流部から該第３現像剤搬送路に現像剤を供給するための第１現像剤供給用開口部を、該第１現像剤搬送路と該第３現像剤搬送路との仕切り部材の該第１現像剤搬送路最下点より上方の位置に設け、
該第１現像剤搬送路と該第３現像剤搬送路とを通気するための通気用開口部を、該第１現像剤供給用開口部よりも該第１現像剤搬送路の搬送方向下流で、且つ、該第１現像剤供給用開口部の最上部よりも上方の位置に設けたことを特徴とする現像装置。 A developer carrier that carries a developer composed of toner and a magnetic carrier and conveys the developer to a portion facing the latent image carrier by rotation;
A first developer conveying path having first developer agitating and conveying means for agitating and conveying the developer along the axial direction of the developer carrying member and supplying the developer to the developer carrying member;
The developer is disposed below the first developer agitating / conveying means, and the developer is recovered from the developer carrying body after passing through the portion facing the latent image carrier, and is in the same direction as the first developer agitating / conveying means. A second developer conveying path having a second developer stirring and conveying means for conveying
The first developer agitating / conveying means is disposed below the first developer agitating / conveying means, and is not supplied to the developer carrier by the first developer agitating / conveying means, but is conveyed to the downstream portion in the conveying direction of the first developer conveying path. The first developer is supplied with the developer and the developer collected from the developer carrier by the second developer agitating and conveying means and conveyed to the downstream portion in the conveying direction of the second developer conveying path. A third developer conveying path having third developer agitating and conveying means that agitates and conveys the developer in the opposite direction to the agitating and conveying means and delivers the developer to the first developer agitating and conveying means on the downstream side;
In the developing device in which the first developer transport path, the second developer transport path, and the third developer transport path are partitioned by a partition member,
A filter that allows air to pass through without passing toner is provided above the first developer transport path,
The partition member that partitions the first developer transport path and the third developer transport path extends upward from the lowest point of the first developer transport path,
A first developer supply opening for supplying developer to the third developer transport path from a downstream portion in the transport direction of the first developer transport path is formed between the first developer transport path and the third development. Provided at a position above the lowest point of the first developer transport path of the partition member with the developer transport path,
A ventilation opening for ventilating the first developer conveyance path and the third developer conveyance path is disposed downstream of the first developer conveyance path in the conveyance direction with respect to the first developer supply opening. And a developing device provided at a position above the uppermost portion of the first developer supply opening. 請求項１の現像装置において、上記第３現像剤攪拌搬送手段の現像剤搬送方向下流部で現像剤を上記第１現像剤攪拌搬送手段に受け渡すために、上記第３現像剤搬送路の搬送方向下流部の上記第１現像剤搬送路との仕切り部材に設ける第３現像剤供給用開口部を、上記現像剤担持体が上記潜像担持体にトナーを供給する現像領域の該軸線方向の幅である現像領域幅内に配置することを特徴とする現像装置。   2. The developing device according to claim 1, wherein transport of the third developer transport path is performed in order to deliver the developer to the first developer stir transport unit downstream of the third developer stir transport unit in the developer transport direction. A third developer supply opening provided in a partition member between the first developer transport path and a downstream portion in the direction of the direction of the axial direction of the developing region in which the developer carrier supplies toner to the latent image carrier. A developing device, wherein the developing device is disposed within a width of a developing area which is a width. 請求項１または２の現像装置において、上記第１現像剤供給用開口部を上記現像剤担持体が上記潜像担持体にトナーを供給する現像領域の該軸線方向の幅である現像領域幅内に配置することを特徴とする現像装置。   3. The developing device according to claim 1, wherein the first developer supply opening is within a development region width that is a width in the axial direction of a development region where the developer carrier supplies toner to the latent image carrier. A developing device characterized by being arranged in 請求項１、２または３の何れかの現像装置において、上記通気用開口部を上記現像剤担持体が上記潜像担持体にトナーを供給する現像領域の該軸線方向の幅である現像領域幅内に配置することを特徴とする現像装置。   4. The developing area width according to claim 1, wherein the developing opening is a width in the axial direction of a developing area where the developer carrying member supplies toner to the latent image carrying body through the ventilation opening. A developing device arranged inside. 潜像担持体と、該潜像担持体を帯電させるための帯電手段と、該潜像担持体上に静電潜像を形成するための潜像形成手段と、該静電潜像を現像してトナー像化するための現像手段とを有する画像形成装置において、
上記現像手段として、請求項１、２、３または４の現像装置を採用することを特徴とする画像形成装置。 A latent image carrier, a charging means for charging the latent image carrier, a latent image forming means for forming an electrostatic latent image on the latent image carrier, and developing the electrostatic latent image. And an image forming apparatus having a developing unit for forming a toner image.
An image forming apparatus using the developing device of claim 1, 2, 3, or 4 as the developing means.
JP2007313559A 2007-12-04 2007-12-04 Developing device and image forming apparatus Withdrawn JP2009139476A (en)

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Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2012189811A (en) * 2011-03-10 2012-10-04 Ricoh Co Ltd Developing device and image forming apparatus
JP2012189787A (en) * 2011-03-10 2012-10-04 Ricoh Co Ltd Developing device and image forming apparatus
JP2013020119A (en) * 2011-07-12 2013-01-31 Canon Inc Developing device
JP2013190758A (en) * 2012-03-15 2013-09-26 Canon Inc Developing device
JP2016200790A (en) * 2015-04-07 2016-12-01 株式会社リコー Powder storage container, developing device, process unit, and image forming apparatus

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2012189811A (en) * 2011-03-10 2012-10-04 Ricoh Co Ltd Developing device and image forming apparatus
JP2012189787A (en) * 2011-03-10 2012-10-04 Ricoh Co Ltd Developing device and image forming apparatus
JP2013020119A (en) * 2011-07-12 2013-01-31 Canon Inc Developing device
JP2013190758A (en) * 2012-03-15 2013-09-26 Canon Inc Developing device
JP2016200790A (en) * 2015-04-07 2016-12-01 株式会社リコー Powder storage container, developing device, process unit, and image forming apparatus

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