JPH08314279A - Developing device - Google Patents

Abstract

PURPOSE: To perform excellent image forming by a developing device using a stirring carrier member provided with a first blade member carrying developer by the center part of a carrier part and a second blade member carrying the developer by the peripheral part of the carrier part in a reverse direction to the first blade member. CONSTITUTION: As for the developing device carrying the developer while stirring it at the inside of the carrier part by rotating the stirring carrier member 13 provided at the inside of the carrier part 12 carrying the developer; the stirring carrier member is provided with the first blade member 134 carrying the developer while stirring by the center part of the carrier part and the second blade member 135 carrying the developer while stirring by the peripheral part of the carrier part in the reverse direction to the first blade member, and the carrier speed of the developer at least at either of the first blade member and the second blade member is made to be higher on the upstream side in the carrier direction of the developer than on a downstream side.

Description

【発明の詳細な説明】Detailed Description of the Invention

【０００１】[0001]

【産業上の利用分野】この発明は、複写機やプリンター
等の画像形成装置において使用される現像装置に係り、
特に、現像剤を搬送させる搬送部内に設けられた撹拌搬
送部材を回転させて、現像剤を搬送部内で撹拌しながら
搬送させるようになった現像装置に関するものである。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a developing device used in an image forming apparatus such as a copying machine or a printer,
In particular, the present invention relates to a developing device configured to rotate a stirring / conveying member provided in a conveying section for conveying the developer so that the developer is conveyed while being stirred in the conveying section.

【０００２】[0002]

【従来の技術】従来より、複写機やプリンター等の画像
形成装置においては、像担持体に形成された静電潜像に
現像装置から現像剤を供給して現像を行なうようにして
おり、このような現像装置としては、様々な種類のもの
が用いられていた。2. Description of the Related Art Conventionally, in an image forming apparatus such as a copying machine or a printer, a developing device supplies a developer to an electrostatic latent image formed on an image carrier to develop the electrostatic latent image. Various types of developing devices have been used.

【０００３】そして、このような現像装置の一つとし
て、現像剤を搬送させる搬送部内に撹拌搬送部材を設
け、この撹拌搬送部材を回転させて、トナーとキャリア
とを含む現像剤をこの搬送部内で混合撹拌しながら搬送
させるようになった現像装置が知られていた。As one of such developing devices, an agitating / conveying member is provided in a conveying part for conveying the developer, and the agitating / conveying member is rotated to allow the developer containing the toner and the carrier to be contained in the conveying part. There is known a developing device which can be conveyed while being mixed and stirred.

【０００４】ここで、このような現像装置としては、一
般に、図１に示すように、像担持体１に現像剤を搬送さ
せる現像スリーブ２の軸方向に沿った２つの搬送部３
ａ，３ｂを仕切り壁４を介して並設させ、この２つの搬
送部３ａ，３ｂ内にそれぞれ撹拌搬送部材５ａ，５ｂを
設け、各撹拌搬送部材５ａ，５ｂを回転させて上記２つ
の搬送部３ａ，３ｂ内においてそれぞれ現像剤を撹拌し
ながら逆方向に搬送させて、現像剤をこの２つの搬送部
３ａ，３ｂ内において循環させると共に、現像スリーブ
２に近接した搬送部３ａにおいて現像剤を現像スリーブ
２に供給するようにしていた。Here, in such a developing device, generally, as shown in FIG. 1, two conveying portions 3 along the axial direction of the developing sleeve 2 for conveying the developer to the image carrier 1 are provided.
a and 3b are arranged side by side through the partition wall 4, agitating and transporting members 5a and 5b are provided in the two transporting units 3a and 3b, respectively, and the agitating and transporting members 5a and 5b are rotated and the above-mentioned two transporting units are provided. The developer is conveyed in the opposite directions while being stirred in 3a and 3b, and the developer is circulated in the two conveying portions 3a and 3b, and the developer is developed in the conveying portion 3a close to the developing sleeve 2. It was supplied to the sleeve 2.

【０００５】しかし、このように現像スリーブ２の軸方
向に沿った２つの搬送部３ａ，３ｂを現像装置内に並設
させた場合、この現像装置が大型化すると共に、各搬送
部３ａ，３ｂに設けられた撹拌搬送部材５ａ，５ｂを回
転させる機構等も必要になって、画像形成装置全体が大
型化する等の問題があり、またトナーを補給する場合
は、一般に現像スリーブ２から離れた搬送部３ｂにトナ
ーを補給するため、補給されたトナーが現像スリーブ２
に導かれるのに長い時間を要し、その間、トナー濃度の
低い現像剤によって現像が行なわれ、形成された画像の
濃度が低下する等の問題もあった。However, when the two transport portions 3a and 3b along the axial direction of the developing sleeve 2 are arranged side by side in the developing device as described above, the developing device becomes large and each of the transport portions 3a and 3b. A mechanism for rotating the agitating / conveying members 5a and 5b, etc., is also required, which causes a problem that the entire image forming apparatus becomes large, and when replenishing the toner, it is generally separated from the developing sleeve 2. To replenish the toner to the transport portion 3b, the replenished toner is supplied to the developing sleeve 2
It takes a long time to be introduced into the recording medium, and during that time, there is a problem that the density of the formed image is lowered by developing with a developer having a low toner density.

【０００６】また、従来においては、米国特許第４７０
７１０７号，第４８８７１３２号及び第４９５６６７５
号公報等に示されるように、搬送部内において現像剤を
撹拌しながら搬送させる撹拌搬送部材に第１羽根部材と
第２羽根部材とを設け、この第１羽根部材によって搬送
部の中心部分における現像剤を撹拌しながら搬送させる
一方、第２羽根部材によって搬送部の周辺部分における
現像剤を撹拌しながら第１羽根部材と逆方向に搬送さ
せ、１つの搬送部内において現像剤を循環させるように
したものや、米国特許第４８２５２４４号公報や特開昭
５４−１１９９３４号公報等に示されるように、搬送部
の中心部分にパイプを配すると共に、このパイプ内に第
１搬送部材を設け、この第２搬送部材によってパイプ内
における現像剤を撹拌しながら搬送させる一方、このパ
イプの周囲における搬送部内の第２搬送部材を設け、こ
の第２搬送部材によりパイプの周囲における搬送部内の
現像剤を撹拌しながら上記の第１搬送部材とは逆方向に
搬送させ、上記のパイプ内とその周囲の搬送部との間で
現像剤を循環させるようにしたものが開発された。Also, in the past, US Pat. No. 470 was used.
No. 7107, No. 4887132 and No. 4956675
As disclosed in Japanese Patent Laid-Open Publication No. 2004-242242, a stirring and conveying member that conveys a developer while stirring in a conveying unit is provided with a first blade member and a second blade member, and the first blade member is used for developing in a central portion of the conveying unit. While the agent is conveyed while being stirred, the developer in the peripheral portion of the conveying section is conveyed in the opposite direction to the first blade member while being stirred by the second blade member, and the developer is circulated in one conveying section. As shown in U.S. Pat. No. 4,825,244 and Japanese Unexamined Patent Publication No. 54-119934, a pipe is arranged in the central portion of the conveying section, and a first conveying member is provided in the pipe. While the developer in the pipe is conveyed while being agitated by the two conveying members, a second conveying member in the conveying portion around the pipe is provided. A configuration in which the developer in the transport section around the pipe is transported in a direction opposite to that of the first transport member while agitating, and the developer is circulated between the transport section in the pipe and the periphery thereof. Was developed.

【０００７】しかし、上記のように撹拌搬送部材に第１
羽根部材と第２羽根部材とを設け、第１羽根部材と第２
羽根部材とにより搬送部の中心部分と周辺部分とで現像
剤を逆方向に搬送させるようにしたものにおいては、搬
送部内における現像剤がその中心部分と周辺部分との間
で局部的に循環することが多く、現像剤が搬送部全体に
わたって搬送されにくくなっていた。このため、この搬
送部にトナーを補給した場合、補給されたトナーが搬送
部全体に搬送されにくく、搬送部内における現像剤全体
にトナーが均一に分散されるのに長い時間がかかり、現
像剤の搬送方向において搬送部内における現像剤のトナ
ー濃度に差が生じ、形成された画像において濃度傾斜が
発生し、またトナーが十分に分散されないためにキャリ
アとの接触確率が低くなって帯電不良のトナーが発生
し、これにより形成される画像に地肌かぶりが発生した
り、トナーが飛散したりする等の問題があった。However, as described above, the first member is added to the stirring and conveying member.
A blade member and a second blade member are provided, and the first blade member and the second blade member are provided.
In a case where the developer is conveyed in the opposite direction by the blade member between the central portion and the peripheral portion of the conveying portion, the developer in the conveying portion circulates locally between the central portion and the peripheral portion. In many cases, the developer is difficult to be carried over the entire carrying section. For this reason, when toner is replenished to the transport unit, the replenished toner is difficult to be transported to the entire transport unit, and it takes a long time for the toner to be uniformly dispersed in the entire developer in the transport unit, and There is a difference in the toner concentration of the developer in the conveyance section in the conveyance direction, a density gradient occurs in the formed image, and the toner is not sufficiently dispersed, so that the probability of contact with the carrier becomes low and the toner with poor charging is generated. However, there are problems such as occurrence of background fog in an image formed by this and toner scattering.

【０００８】また、上記のように搬送部の中心部分にパ
イプを配し、このパイプ内に設けた第１搬送部材と、パ
イプの周囲における搬送部内に設けた第２搬送部材とに
よって、現像剤をパイプ内と搬送部とにおいて逆方向に
搬送させ、現像剤を搬送部とパイプ内との間で循環させ
るようにしたものにおいては、一般にトナーをパイプ内
に補給し、このようにトナーが補給された現像剤を上記
の第１搬送部材によりパイプ内を搬送させて搬送部に導
き、これを第２搬送部材により搬送部内で搬送させると
共に、この現像剤を現像スリーブに供給するようになっ
ていた。このため、この場合においても、補給されたト
ナーが現像剤全体に均一に分散されるのに時間がかか
り、キャリアとの接触によるトナーの帯電が上手く行な
われず、不良帯電トナーが発生し、これにより形成され
る画像に地肌かぶりが発生したり、トナーが飛散したり
する等の問題があり、さらに搬送部の中心部分にパイプ
を設けると共に、このパイプ内に第１搬送部材を設ける
ため、その製造コストも高くつく等の問題があった。Further, as described above, the pipe is arranged in the central portion of the carrying section, and the first carrying member provided in the pipe and the second carrying member provided in the carrying section around the pipe make the developer When the developer is conveyed in the opposite direction in the pipe and the conveying section and the developer is circulated between the conveying section and the pipe, the toner is generally replenished in the pipe, and the toner is replenished in this way. The developer thus conveyed is conveyed in the pipe by the first conveying member and guided to the conveying section, and is conveyed by the second conveying member in the conveying section, and at the same time, the developer is supplied to the developing sleeve. It was Therefore, even in this case, it takes time for the replenished toner to be uniformly dispersed in the entire developer, the toner is not properly charged due to the contact with the carrier, and a poorly charged toner is generated. There are problems such as background fog in the formed image and toner scattering. Further, since a pipe is provided in the central portion of the conveying unit and the first conveying member is provided in this pipe, the production thereof is performed. There were problems such as high cost.

【０００９】[0009]

【発明が解決しようとする課題】この発明は、複写機や
プリンター等の画像形成装置に使用される現像装置であ
って、現像剤を搬送させる搬送部内に設けられた撹拌搬
送部材を回転させて、現像剤を搬送部内で撹拌しながら
搬送させるようにした場合における上記のような様々な
問題を解決することを課題とするものである。SUMMARY OF THE INVENTION The present invention is a developing device used in an image forming apparatus such as a copying machine or a printer, in which a stirring and conveying member provided in a conveying portion for conveying the developer is rotated. It is an object of the present invention to solve various problems as described above in the case where the developer is conveyed while being stirred in the conveying section.

【００１０】ここで、この発明においては、現像剤を搬
送部内で撹拌しながら搬送させる撹拌搬送部材に、現像
剤を搬送部の中心部分で搬送させる第１羽根部材と現像
剤を搬送部の周辺部分で上記第１羽根部材と逆方向に搬
送させる第２羽根部材とを設け、この第１羽根部材と第
２羽根部材とによって現像剤を互いに逆方向に搬送させ
るようになった現像装置において、トナーを補給した場
合に、このトナーが搬送部内における現像剤全体に速や
かに分散されると共に、このトナーが適切に帯電され、
形成される画像に濃度傾斜が発生するということがな
く、均一な濃度になった画像形成が行なえると共に、帯
電不良のトナーによって形成される画像に地肌かぶりが
生じたり、トナーが飛散したりすることがない現像装置
を提供することを目的とするものである。Here, in the present invention, the stirring and conveying member that conveys the developer while stirring in the conveying unit, the first blade member that conveys the developer in the central portion of the conveying unit, and the periphery of the conveying unit. In a developing device, a portion is provided with a second blade member for conveying in the opposite direction to the first blade member, and the developer is conveyed in opposite directions by the first blade member and the second blade member, When the toner is replenished, this toner is quickly dispersed throughout the developer in the conveying section, and this toner is appropriately charged,
An image with a uniform density can be formed without causing a density gradient in the formed image, and a background fog occurs or the toner scatters in the image formed by a poorly charged toner. It is an object of the present invention to provide a developing device that does not have such a problem.

【００１１】[0011]

【課題を解決するための手段】この発明においては、上
記のような課題を解決するため、現像剤を搬送させる搬
送部内に設けられた撹拌搬送部材を回転させて、現像剤
を搬送部内で撹拌しながら搬送させる現像装置におい
て、上記の撹拌搬送部材に、現像剤を搬送部の中心部分
で撹拌しながら搬送させる第１羽根部材と、現像剤を搬
送部の周辺部分で撹拌しながら上記第１羽根部材と逆方
向に搬送させる第２羽根部材とを設け、上記第１羽根部
材と第２羽根部材の少なくとも一方における現像剤の搬
送速度を、現像剤の搬送方向下流側より上流側の方が速
くなるようにしたのである。According to the present invention, in order to solve the above problems, the agitating / conveying member provided in the conveying section for conveying the developer is rotated to stir the developer in the conveying section. In the developing device for transporting while carrying out the above-mentioned stirring and carrying member, the first blade member for carrying the developer while stirring at the central portion of the carrying section, and the first stirring member for carrying the developer at the peripheral portion of the carrying section. A blade member and a second blade member for transporting in the opposite direction are provided, and the developer transport speed in at least one of the first blade member and the second blade member is more upstream than downstream in the developer transport direction. I made it faster.

【００１２】ここで、上記の撹拌搬送部材における第１
羽根部材や第２羽根部材において、現像剤の搬送速度を
現像剤の搬送方向下流側より上流側の方が速くなるよう
にするにあたっては、第１羽根部材や第２羽根部材にお
ける羽根のピッチを現像剤の搬送方向上流側から下流側
に向けて狭くする等の様々な方法によって行なうことが
できる。なお、この発明においては、上記のように第１
羽根部材と第２羽根部材の少なくとも一方において、現
像剤の搬送速度を搬送方向下流側より上流側の方が速く
なるようにしておけばよいが、より好ましくは、第１羽
根部材と第２羽根部材との双方において、それぞれ現像
剤の搬送速度がその搬送方向下流側より上流側の方が速
なるようにすることが望ましい。[0012] Here, the first of the above-mentioned stirring and conveying member.
In the blade member and the second blade member, the pitch of the blades in the first blade member and the second blade member is set so that the developer conveying speed becomes faster on the upstream side than on the downstream side in the developer conveying direction. It can be carried out by various methods such as narrowing from the upstream side to the downstream side in the developer conveying direction. In the present invention, as described above, the first
In at least one of the blade member and the second blade member, the developer may be transported at a speed higher on the upstream side than on the downstream side in the transport direction, but more preferably, the first blade member and the second blade. It is desirable that both the member and the member have a developer transport speed higher on the upstream side than on the downstream side in the transport direction.

【００１３】[0013]

【作用】この発明における現像装置においては、上記の
ように撹拌搬送部材に、現像剤を搬送部の中心部分で撹
拌しながら搬送させる第１羽根部材と、現像剤を搬送部
の周辺部分で撹拌しながら上記第１羽根部材と逆方向に
搬送させる第２羽根部材とを設け、この撹拌搬送部材を
回転させて現像剤を搬送部の中心部分と周辺部分とで現
像剤を逆方向に搬送させて循環させるにあたり、第１羽
根部材と第２羽根部材の少なくとも一方における現像剤
の搬送速度がその搬送方向下流側より上流側の方が速く
なるようにしたため、現像剤の搬送速度が速くなった搬
送方向上流側の部分において現像剤がその搬送方向に速
やかに移動されるようになる。In the developing device according to the present invention, as described above, the agitating / conveying member conveys the developer while stirring the developer in the central portion of the conveying portion, and the developer in the peripheral portion of the conveying portion. However, a second blade member that conveys the developer in the opposite direction to the first blade member is provided, and the stirring and conveying member is rotated to convey the developer in the opposite direction between the central portion and the peripheral portion of the conveying portion. In the circulation, the developer transport speed in at least one of the first blade member and the second blade member is set to be higher on the upstream side than on the downstream side in the transport direction, so that the developer transport speed is increased. The developer is quickly moved in the carrying direction in the upstream portion in the carrying direction.

【００１４】このため、トナーを現像剤の搬送速度が速
くなった搬送方向上流側の部分に補給した場合、トナー
が補給された現像剤がその搬送方向に速やかに移動され
ると共に、搬送部の中心部分と周辺部分との間で混合さ
れて、補給されたトナーが速やかにこの搬送部内におけ
る現像剤全体に分散されるようになり、現像剤の搬送方
向において搬送部内における現像剤のトナー濃度に差が
生じるということがなく、また補給されたトナーが搬送
部内における現像剤中のキャリアと十分に接触して適切
に帯電されるようになり、形成された画像において濃度
むらや地肌かぶりが発生するということがなくなると共
に、トナーが現像装置から飛散するということもなくな
る。For this reason, when the toner is replenished to the upstream portion in the conveying direction where the developer conveying speed has increased, the toner-supplemented developer is quickly moved in the conveying direction, and at the same time, in the conveying section. The mixed toner between the central portion and the peripheral portion allows the replenished toner to be quickly dispersed in the entire developer in the transport section, and the toner concentration of the developer in the transport section in the developer transport direction can be improved. There is no difference, and the replenished toner comes into sufficient contact with the carrier in the developer in the transport section to be properly charged, and uneven density or background fogging occurs in the formed image. In addition to the above, the toner is not scattered from the developing device.

【００１５】[0015]

【実施例】以下、この発明の実施例に係る現像装置を添
付図面に基づいて具体的に説明すると共に比較例と比較
し、この実施例の現像装置においては、補給されたトナ
ーが搬送部内の現像剤中に速やかに均一に分散されるこ
とを明らかにする。DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A developing device according to an embodiment of the present invention will be specifically described below with reference to the accompanying drawings and compared with a comparative example. In the developing device of this embodiment, the replenished toner is stored in a conveying section. It is revealed that it is rapidly and uniformly dispersed in the developer.

【００１６】この実施例における現像装置においては、
図２に示すように、現像剤を像担持体に搬送する現像ス
リーブ１１の軸方向に沿って、この現像スリーブ１１と
隣接して現像剤を搬送させる搬送部１２を設け、この搬
送部１２内に現像剤を撹拌しながら現像スリーブ１１の
軸方向に沿って搬送させる撹拌搬送部材１３を設けるよ
うにした。In the developing device of this embodiment,
As shown in FIG. 2, a transport section 12 for transporting the developer is provided adjacent to the developing sleeve 11 along the axial direction of the developing sleeve 11 for transporting the developer to the image carrier. Further, a stirring and conveying member 13 for conveying the developer along the axial direction of the developing sleeve 11 while stirring the developer is provided.

【００１７】ここで、上記の撹拌搬送部材１３として、
この実施例においては、図２及び図３に示すように、現
像スリーブ１１の軸方向両端部における回転軸１３１に
それぞれ大径の取付部１３２と小径の取付部１３３とを
設け、小径の取付部１３３間に現像剤を搬送部１２の中
心部分で搬送させる回転径が２０ｍｍの螺旋状になった
第１羽根部材１３４を設ける一方、大径の取付部１３２
間においては現像剤を搬送部１２の周辺部分で上記第１
羽根部材１３４と逆方向に搬送させる回転径が６０ｍｍ
の螺旋状になった第２羽根部材１３５を設けるようにし
た。Here, as the above-mentioned stirring and conveying member 13,
In this embodiment, as shown in FIGS. 2 and 3, a large-diameter mounting portion 132 and a small-diameter mounting portion 133 are provided on the rotary shaft 131 at both axial ends of the developing sleeve 11, respectively, and the small-diameter mounting portion is provided. A spiral first blade member 134 having a rotation diameter of 20 mm is provided between 133 for transporting the developer in the central portion of the transport unit 12, while a large-diameter mounting portion 132 is provided.
In the interval between the above-mentioned
Rotation diameter for conveying in the opposite direction to the blade member 134 is 60 mm
The second blade member 135 having a spiral shape is provided.

【００１８】そして、上記の第１羽根部材１３４におい
ては、その現像剤の搬送方向上流側の部分における羽根
間のピッチＰ１を２０ｍｍにし、現像剤の搬送方向下流
側に向かうに連れてその羽根間のピッチを小さくして、
下流側の部分における羽根間のピッチＰ２が１０ｍｍに
なるようにした。一方、上記の第２羽根部材１３５にお
いては、その現像剤の搬送方向上流側、すなわち第１羽
根部材１３４における現像剤の搬送方向下流側の部分に
おける羽根間のピッチＰ１を２０ｍｍにし、現像剤の搬
送方向下流側に向かうに連れてその羽根間のピッチを小
さくして、下流側の部分における羽根間のピッチＰ２が
１０ｍｍになるようにした。In the above first blade member 134, the pitch P1 between the blades in the upstream portion of the developer conveying direction is set to 20 mm, and the distance between the blades moves toward the downstream side in the developer conveying direction. Decrease the pitch of
The pitch P2 between the blades in the downstream portion was set to 10 mm. On the other hand, in the above-mentioned second blade member 135, the pitch P1 between the blades at the upstream side in the developer transport direction, that is, the portion of the first blade member 134 on the downstream side in the developer transport direction is set to 20 mm, and The pitch between the blades is reduced toward the downstream side in the transport direction so that the pitch P2 between the blades in the downstream portion is 10 mm.

【００１９】そして、このように第１羽根部材１３４と
第２羽根部材１３５とが設けられた撹拌搬送部材１３を
搬送部１２内において回転させると、上記の第１羽根部
材１３４において羽根間のピッチが大きくなった現像剤
の搬送方向上流側の部分においては、この搬送部１２の
中心部分における現像剤がこの第１羽根部材１３４によ
り現像スリーブ１１の軸方向に沿ってその下流側に速や
かに送られると共に、この搬送部１２の周辺部分におけ
る現像剤は羽根間のピッチが小さくなった第２羽根部材
１３５によって第１羽根部材１３４とは反対方向に徐々
に送られるようになった。一方、第２羽根部材１３５に
おいて羽根間のピッチが大きくなった現像剤の搬送方向
上流側の部分においては、この搬送部１２の周辺部分に
おける現像剤がこの第２羽根部材１３５により現像スリ
ーブ１１の軸方向に沿ってその下流側に速やかに送られ
ると共に、この搬送部１２の中心部分における現像剤は
羽根間のピッチが小さくなった第１羽根部材１３４によ
って徐々に送られるようになった。When the stirring / conveying member 13 provided with the first blade member 134 and the second blade member 135 is rotated in the conveying section 12, the pitch between the blades of the first blade member 134 is increased. In the upstream portion of the developer in the conveyance direction, the developer in the central portion of the conveyance portion 12 is quickly sent to the downstream side along the axial direction of the developing sleeve 11 by the first blade member 134. At the same time, the developer in the peripheral portion of the transport unit 12 is gradually fed in the direction opposite to the first blade member 134 by the second blade member 135 having a smaller pitch between the blades. On the other hand, in the portion of the second blade member 135 on the upstream side in the developer conveying direction where the pitch between the blades is increased, the developer in the peripheral portion of the conveying portion 12 is transferred to the developing sleeve 11 by the second blade member 135. The developer in the central portion of the carrying portion 12 is gradually fed along the axial direction to the downstream side thereof, and is gradually fed by the first blade member 134 in which the pitch between the blades is reduced.

【００２０】この結果、この実施例の現像装置において
は、図２に示すように、搬送部１２内における現像剤が
撹拌搬送部材１３に設けられた第１羽根部材１３４と第
２羽根部材１３５とによって上記のように現像スリーブ
１１の軸方向に沿って搬送部１２の中心部分と周辺部分
とで逆方向に搬送されると共に、搬送部１２の両側部分
において現像剤が搬送部１２の中心部分と周辺部分とで
混合されて循環されるようになった。As a result, in the developing device of this embodiment, as shown in FIG. 2, the developer in the conveying section 12 is provided with the first blade member 134 and the second blade member 135 provided on the stirring and conveying member 13. As described above, the central portion and the peripheral portion of the conveying portion 12 are conveyed in opposite directions along the axial direction of the developing sleeve 11, and the developer is conveyed to the central portion of the conveying portion 12 at both side portions of the conveying portion 12. It became mixed with the surrounding area and circulated.

【００２１】次に、この実施例の現像装置における搬送
部１２内にトナー濃度が３重量％になった現像剤を収容
させた状態で、上記の撹拌搬送部材１３を回転させて、
現像剤を上記のように搬送部１２内で混合撹拌しながら
搬送させて、搬送部１２内における現像剤を現像スリー
ブ１１に供給すると共に、上記第１羽根部材１３４にお
ける現像剤搬送方向上流側の部分に上記の現像剤の２重
量％にあたるトナーを補給し、図２に示すように、現像
スリーブ１１の両側及び中央におけるＢ，Ｃ，Ｄの各部
分に供給された現像剤におけるトナー濃度の経時変化を
測定し、その結果を図４に示した。なお、この図４にお
いては、Ｂ部分に供給された現像剤におけるトナー濃度
の変化を実線で、Ｃ部分に供給された現像剤におけるト
ナー濃度の変化を破線で、Ｄ部分に供給された現像剤に
おけるトナー濃度の変化を一点鎖線で示した。Next, while the developer having a toner concentration of 3% by weight is contained in the carrying section 12 of the developing device of this embodiment, the agitating and carrying member 13 is rotated,
The developer is conveyed while being mixed and stirred in the conveying section 12 as described above, and the developer in the conveying section 12 is supplied to the developing sleeve 11, and at the upstream side of the developer conveying direction in the first blade member 134. The toner corresponding to 2% by weight of the developer is replenished to the portion, and as shown in FIG. 2, the toner concentration in the developer supplied to the portions B, C, and D on both sides and the center of the developing sleeve 11 with the passage of time. The change was measured and the result is shown in FIG. In FIG. 4, the solid line represents the change in the toner density of the developer supplied to the portion B, the broken line represents the change in the toner density of the developer supplied to the portion C, and the developer supplied to the portion D is the same. The change in the toner density in the above is shown by the alternate long and short dash line.

【００２２】一方、この実施例の現像装置と比較するた
め、比較例１においては、図５に示すように、搬送部１
２内における現像剤を撹拌しながら現像スリーブ１１の
軸方向に沿って搬送させる撹拌搬送部材１４として、回
転軸１４１の周囲に小径の第１羽根部材１４４と大径の
第２羽根部材１４５とをそれぞれ一定のピッチで設けた
ものを用い、この撹拌搬送部材１４を搬送部１２内で回
転させて、小径の第１羽根部材１４４により搬送部１２
の中心部分における現像剤を撹拌しながら搬送させる一
方、大径の第２羽根部材１４５により搬送部１２の周辺
部分における現像剤を撹拌しながら上記第１羽根部材１
４４と逆方向に現像剤を搬送させるようにした。On the other hand, in order to compare with the developing device of this embodiment, in Comparative Example 1, as shown in FIG.
As a stirring / conveying member 14 that conveys the developer in 2 along the axial direction of the developing sleeve 11, a small-diameter first blade member 144 and a large-diameter second blade member 145 are provided around the rotating shaft 141. The agitating and conveying member 14 is rotated in the conveying unit 12 by using those provided at a constant pitch, and the conveying unit 12 is rotated by the first blade member 144 having a small diameter.
While the developer in the central portion of the first blade member 1 is conveyed while being stirred, the second blade member 145 having a large diameter is used to stir the developer in the peripheral portion of the conveying portion 12 while the first blade member 1 is being stirred.
The developer is conveyed in the direction opposite to 44.

【００２３】そして、この比較例１のものにおいても、
上記実施例の場合と同様に、搬送部１２内にトナー濃度
が３重量％になった現像剤を収容させた状態で、上記の
撹拌搬送部材１４を回転させて、現像剤を上記のように
搬送部１２内で混合撹拌しながら搬送させて、搬送部１
２内における現像剤を現像スリーブ１１に供給すると共
に、上記第１羽根部材１４４における現像剤搬送方向上
流側の部分に上記の現像剤の２重量％にあたるトナーを
補給し、図５に示すように、現像スリーブ１１の両側及
び中央におけるＢ，Ｃ，Ｄの各部分に供給された現像剤
におけるトナー濃度の経時変化を測定し、その結果を図
６に示した。なお、この図６においても、Ｂ部分に供給
された現像剤におけるトナー濃度の変化を実線で、Ｃ部
分に供給された現像剤におけるトナー濃度の変化を破線
で、Ｄ部分に供給された現像剤におけるトナー濃度の変
化を一点鎖線で示した。And, also in the case of Comparative Example 1,
As in the case of the above-described embodiment, while the developer having the toner concentration of 3% by weight is contained in the transport unit 12, the stirring and transporting member 14 is rotated to remove the developer as described above. Transporting is performed in the transporting unit 12 while mixing and stirring, and the transporting unit 1
The developer in 2 is supplied to the developing sleeve 11, and 2% by weight of the developer is replenished to the upstream side portion of the first blade member 144 in the developer conveying direction, as shown in FIG. The changes over time in the toner density of the developer supplied to the portions B, C, and D on both sides and the center of the developing sleeve 11 were measured, and the results are shown in FIG. Also in FIG. 6, the change in toner concentration in the developer supplied to the portion B is shown by a solid line, the change in toner concentration in the developer supplied to the portion C is shown by a broken line, and the change in toner concentration in the developer supplied to the portion D is shown. The change in the toner density in the above is shown by the alternate long and short dash line.

【００２４】また、比較例２においては、図７に示すよ
うに、現像剤を搬送させる搬送部１２内に現像スリーブ
１１に沿って現像剤搬送用のパイプ１５を設けると共
に、このパイプ１５内に現像剤を撹拌しながら搬送させ
る第１搬送部材１６を配する一方、このパイプ１５の外
周側に現像剤を撹拌しながら上記の第１搬送部材１６と
逆方向に現像剤を搬送させる第２搬送部材１７を設け、
上記第１搬送部材１６と第２搬送部材１７とによって現
像剤をパイプ１５内とこのパイプ１５の外周側における
搬送部１２との間で循環させるようにした。Further, in Comparative Example 2, as shown in FIG. 7, a pipe 15 for carrying the developer is provided along the developing sleeve 11 in the carrying section 12 for carrying the developer, and in the pipe 15. While the first transport member 16 for transporting the developer while stirring is arranged, the second transport for transporting the developer in the opposite direction to the first transport member 16 while stirring the developer on the outer peripheral side of the pipe 15. The member 17 is provided,
The developer is circulated between the pipe 15 and the conveying portion 12 on the outer peripheral side of the pipe 15 by the first conveying member 16 and the second conveying member 17.

【００２５】そして、この比較例２のものにおいても、
上記実施例の場合と同様に、搬送部１２及びパイプ１５
内にトナー濃度が３重量％になった現像剤を収容させた
状態で、上記の第１搬送部材１６と第２搬送部材１７と
を回転させて、現像剤を上記のように搬送部１２とパイ
プ１５とにおいて混合撹拌しながら搬送させ、パイプ１
５の外周側における搬送部１２内の現像剤を現像スリー
ブ１１に供給すると共に、上記パイプ１５における現像
剤搬送方向上流側の部分に現像剤の２重量％にあたるト
ナーを補給し、図７に示すように、現像スリーブ１１の
両側及び中央におけるＢ，Ｃ，Ｄの各部分に供給された
現像剤におけるトナー濃度の経時変化を測定し、その結
果を図８に示した。なお、この図８においても、Ｂ部分
に供給された現像剤におけるトナー濃度の変化を実線
で、Ｃ部分に供給された現像剤におけるトナー濃度の変
化を破線で、Ｄ部分に供給された現像剤におけるトナー
濃度の変化を一点鎖線で示した。And, also in this Comparative Example 2,
As in the case of the above embodiment, the transport unit 12 and the pipe 15
With the developer having a toner concentration of 3% by weight contained therein, the first transport member 16 and the second transport member 17 are rotated to transfer the developer to the transport unit 12 as described above. Pipe 1 is conveyed while being mixed and stirred with pipe 15.
5, the developer in the carrying section 12 on the outer peripheral side of 5 is supplied to the developing sleeve 11, and the portion of the pipe 15 on the upstream side in the developer carrying direction is replenished with toner corresponding to 2% by weight of the developer. As described above, the change with time of the toner concentration in the developer supplied to the portions B, C, and D on both sides and the center of the developing sleeve 11 was measured, and the results are shown in FIG. In FIG. 8 as well, the solid line represents the change in the toner density of the developer supplied to the portion B, the broken line represents the change in the toner density of the developer supplied to the portion C, and the developer supplied to the portion D is the same. The change in the toner density in the above is shown by the alternate long and short dash line.

【００２６】ここで、上記の比較例１のものにおいて
は、トナーが補給された搬送部１２の中心部分における
現像剤が、第１羽根部材１４４によって現像スリーブ１
１の軸方向に搬送される他に、トナーが補給された現像
剤が搬送部１２の中心部分と周辺部分とで多く混合さ
れ、トナーを補給した当初、トナーを補給した部分にお
いて現像スリーブ１１に供給される現像剤のトナー濃度
が非常に高くなり、補給されたトナーが搬送部１２内に
おける現像剤全体にうまく分散されず、搬送部１２内に
おいて現像剤中のトナー濃度に傾斜が生じ、また補給さ
れたトナーがキャリアと十分に混合撹拌されず、帯電不
良のトナーが現像スリーブ１１に供給され、形成される
画像に濃度むらや地肌かぶり等が発生すると共に、帯電
不良のトナーが現像装置から飛散した。Here, in the case of Comparative Example 1 described above, the developer in the central portion of the conveying portion 12 to which the toner has been replenished is developed by the first blade member 144.
In addition to being conveyed in the axial direction of 1, the toner-supplemented developer is mixed in a large amount in the central portion and the peripheral portion of the conveying portion 12, and when the toner is replenished, the developing sleeve 11 is initially supplied to the developing sleeve 11. The toner concentration of the supplied developer becomes very high, the replenished toner is not well dispersed in the entire developer in the transport unit 12, the toner concentration in the developer in the transport unit 12 is inclined, and The replenished toner is not sufficiently mixed and agitated with the carrier, the poorly charged toner is supplied to the developing sleeve 11, uneven density and background fogging occur in the formed image, and the poorly charged toner is discharged from the developing device. Scattered.

【００２７】また、比較例２のものにおいては、トナー
が補給された現像剤を第１搬送部材１６によりパイプ１
５内において撹拌しながら搬送させて搬送部１２に導く
ために、トナーが補給された現像剤が現像スリーブ１１
に供給されるのに時間がかかると共に、補給されたトナ
ーはパイプ１５内とその外周側における搬送部１２とを
搬送される途中で徐々に現像剤中に分散されるため、補
給されたトナーが搬送部１２における現像剤に均一に分
散されるのに時間がかかり、搬送部１２内における現像
剤中のトナー濃度にむらが生じ、また補給されたトナー
がキャリアと十分に混合撹拌されずに帯電不良のトナー
が発生し、形成される画像に濃度むらや地肌かぶり等が
発生すると共に、帯電不良のトナーが現像装置から飛散
した。Further, in the comparative example 2, the developer supplied with the toner is supplied to the pipe 1 by the first conveying member 16.
The toner-supplemented developer is supplied to the developing sleeve 11 in order to convey the toner while stirring and to guide it to the conveying portion 12.
It takes time to be supplied to the toner, and the replenished toner is gradually dispersed in the developer while being conveyed through the pipe 15 and the conveying portion 12 on the outer peripheral side thereof. It takes time to be uniformly dispersed in the developer in the transport unit 12, uneven toner concentration in the developer in the transport unit 12 occurs, and the replenished toner is not sufficiently mixed and stirred with the carrier and charged. Defective toner was generated, uneven density and background fog were generated in the formed image, and toner with poor charging was scattered from the developing device.

【００２８】これに対して、この発明の実施例における
現像装置においては、図４に示ように、搬送部１２内に
おける現像剤のトナー濃度が局部的に高くなるというこ
とがなく、補給されたトナーが速やかに搬送部１２内に
おける現像剤全体に分散されるようになり、搬送部１２
内において現像剤のトナー濃度に傾斜が生じるというこ
とがなく、また補給されたトナーがキャリアと十分に混
合撹拌されて適切に帯電されるようになって、形成され
た画像に濃度むらや地肌かぶり等が発生するということ
がなく、良好な画像が得られ、またトナーが現像装置か
ら飛散するということもなかった。On the other hand, in the developing device according to the embodiment of the present invention, as shown in FIG. 4, the toner concentration of the developer in the carrying section 12 was replenished without locally increasing. The toner is quickly dispersed throughout the developer in the transport unit 12,
There is no gradient in the toner concentration of the developer inside, and the replenished toner is sufficiently mixed and stirred with the carrier so that it is appropriately charged, and the formed image has uneven density and background fog. And the like, a good image was obtained, and the toner was not scattered from the developing device.

【００２９】[0029]

【発明の効果】以上詳述したように、この発明の現像装
置においては、搬送部内において現像剤を撹拌しながら
搬送させる撹拌搬送部材に、現像剤を搬送部の中心部分
で撹拌しながら搬送させる第１羽根部材と、現像剤を搬
送部の周辺部分で撹拌しながら上記第１羽根部材と逆方
向に搬送させる第２羽根部材とを設け、第１羽根部材と
第２羽根部材の少なくとも一方における現像剤の搬送速
度をその搬送方向下流側より上流側の方が速くなるよう
にしたため、搬送部の中心部分や周辺部分において現像
剤がその搬送方向に速やかに移動させると共に、搬送部
の中心部分と周辺部分との間で現像剤がうまく混合され
て循環され、トナーを補給した場合にも、このトナーが
速やかにこの搬送部内における現像剤全体に分散される
ようになった。As described above in detail, in the developing device of the present invention, the agitating / conveying member for agitating and conveying the developer in the conveying section conveys the developer while agitating in the central portion of the conveying section. A first blade member and a second blade member that conveys the developer in the opposite direction to the first blade member while stirring the developer in the peripheral portion of the conveying unit are provided, and at least one of the first blade member and the second blade member is provided. Since the developer transport speed is made higher on the upstream side than on the downstream side in the transport direction, the developer is quickly moved in the transport direction in the central portion and the peripheral portions of the transport portion, and at the same time, the central portion of the transport portion is transported. The developer is well mixed and circulated between the peripheral portion and the peripheral portion, and even when the toner is replenished, the toner is promptly dispersed in the entire developer in the transport portion.

【００３０】この結果、この発明の現像装置において
は、トナーを補給した場合にも、現像剤の搬送方向にお
いて搬送部内における現像剤のトナー濃度に差が生じる
ということがなく、また補給されたトナーが搬送部内に
おける現像剤中のキャリアと十分に接触して適切に帯電
されるようになり、形成された画像において濃度むらや
地肌かぶり等が発生したり、トナーが現像装置から飛散
したりするということがなく、良好な画像形成が行なえ
るようになった。As a result, in the developing device of the present invention, even when the toner is replenished, there is no difference in the toner concentration of the developer in the conveying portion in the developer conveying direction, and the replenished toner is supplied. Is sufficiently contacted with the carrier in the developer in the transport section to be appropriately charged, resulting in uneven density or background fog in the formed image, and toner scattering from the developing device. And good image formation can be performed.

【図面の簡単な説明】[Brief description of drawings]

【図１】現像装置内に現像スリーブの軸方向に沿って２
つの搬送部を設けた従来の現像装置の概略断面図であ
る。FIG. 1 is a view in which a developing sleeve 2 is provided in a developing device along an axial direction of the developing sleeve.
It is a schematic sectional drawing of the conventional developing device which provided the one conveyance part.

【図２】この発明の一実施例に係る現像装置の概略説明
図である。FIG. 2 is a schematic explanatory diagram of a developing device according to an embodiment of the present invention.

【図３】上記の実施例において使用した撹拌搬送部材の
概略説明図である。FIG. 3 is a schematic explanatory view of a stirring / conveying member used in the above examples.

【図４】上記の実施例の現像装置にトナーを補給した場
合において、現像スリーブの両側及び中央の各部分に供
給された現像剤におけるトナー濃度の経時変化を示した
図である。FIG. 4 is a diagram showing a change over time in the toner concentration in the developer supplied to both sides and the center of the developing sleeve when toner is supplied to the developing device of the above embodiment.

【図５】比較例１において使用した現像装置の概略説明
図である。5 is a schematic explanatory diagram of a developing device used in Comparative Example 1. FIG.

【図６】比較例１の現像装置にトナーを補給した場合に
おいて、現像スリーブの両側及び中央の各部分に供給さ
れた現像剤におけるトナー濃度の経時変化を示した図で
ある。FIG. 6 is a diagram showing changes over time in toner concentration in the developer supplied to both sides and the center of the developing sleeve when toner is supplied to the developing device of Comparative Example 1;

【図７】比較例２において使用した現像装置の概略説明
図である。7 is a schematic explanatory view of a developing device used in Comparative Example 2. FIG.

【図８】比較例２の現像装置にトナーを補給した場合に
おいて、現像スリーブの両側及び中央の各部分に供給さ
れた現像剤におけるトナー濃度の経時変化を示した図で
ある。FIG. 8 is a diagram showing changes over time in toner concentration in the developer supplied to both sides and the center of the developing sleeve when toner is supplied to the developing device of Comparative Example 2;

【符号の説明】[Explanation of symbols]

１１ 現像スリーブ １２ 搬送部 １３ 撹拌搬送部材 １３４ 第１羽根部材 １３５ 第２羽根部材 11 Development Sleeve 12 Conveying Section 13 Stirring Conveying Member 134 First Blade Member 135 Second Blade Member

Claims (1)

【特許請求の範囲】[Claims] 【請求項１】 現像剤を搬送させる搬送部内に設けられ
た撹拌搬送部材を回転させて、現像剤を搬送部内で撹拌
しながら搬送させる現像装置において、上記の撹拌搬送
部材に、現像剤を搬送部の中心部分で撹拌しながら搬送
させる第１羽根部材と、現像剤を搬送部の周辺部分で撹
拌しながら上記第１羽根部材と逆方向に搬送させる第２
羽根部材とが設けられ、上記第１羽根部材と第２羽根部
材の少なくとも一方における現像剤の搬送速度が、現像
剤の搬送方向下流側より上流側の方が速くなっているこ
とを特徴とする現像装置。1. A developing device for rotating a stirring / transporting member provided in a transporting unit for transporting the developer to transport the developer while stirring in the transporting unit, and transporting the developer to the stirring / transporting member. A first blade member that conveys while agitating in the central portion of the portion, and a second blade member that conveys the developer in the opposite direction to the first blade member while agitating in the peripheral portion of the conveying portion.
A blade member is provided, and the developer transport speed in at least one of the first blade member and the second blade member is higher on the upstream side than on the downstream side in the developer transport direction. Development device.