JP2007298824A - Developing device - Google Patents

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JP2007298824A
JP2007298824A JP2006127620A JP2006127620A JP2007298824A JP 2007298824 A JP2007298824 A JP 2007298824A JP 2006127620 A JP2006127620 A JP 2006127620A JP 2006127620 A JP2006127620 A JP 2006127620A JP 2007298824 A JP2007298824 A JP 2007298824A
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stirring
component developer
toner
developing device
stirring chamber
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Toshito Shimoda
敏人 下田
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Murata Machinery Ltd
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Murata Machinery Ltd
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Abstract

<P>PROBLEM TO BE SOLVED: To suitably perform toner charge by suppressing irregularity of a two-component developer passing through a detection region of a toner concentration sensor, and stabilizing output of the toner concentration sensor to perform suitable toner supply. <P>SOLUTION: In a developing device, a gap of a constant interval formed between an inner face of an agitating chamber 43 and a regulated face 50 is set to be a detection flow passage 52 through which the two-component developer passes, and the cross sectional area of the detection flow passage 52 is made to be smaller than the cross sectional area of a flow passage at another position in the agitating chamber 43 in order to have an amount of the two-component developer 81 passing through the detection region of the toner concentration sensor constant. Consequently, the irregularity of the amount of the two-component developer 81 passing through the detection area 63 of the toner concentration sensor is suppressed. Thus, the irregularity of permeability is suppressed, and the output of the toner concentration sensor can be stabilized, while suitable toner supply is performed to perform the suitable toner charge. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

本発明は、現像装置に関し、より詳細にはトナー濃度センサを備えた現像装置の技術に関する。   The present invention relates to a developing device, and more particularly to a technology of a developing device provided with a toner density sensor.

従来、プリンタ、複合機、及びファクシミリ等の画像形成装置には現像装置が設けられており、現像剤として、トナーとキャリアとからなる２成分現像剤が用いられているものがある。２成分現像剤が用いられる現像装置の内部には、２成分現像剤を攪拌及び循環させて現像に供する攪拌室と、現像剤を攪拌及び搬送するための攪拌搬送部材とが設けられている。攪拌搬送部材には回転軸の軸方向に沿って螺旋状の撹拌羽根が形成されており、攪拌搬送部材が前記攪拌室内で軸周りに回転する。攪拌搬送部材により、トナーとキャリアとが攪拌室内を搬送され、その間にキャリアとトナーとが混合・攪拌されてトナーが帯電される。   2. Description of the Related Art Conventionally, image forming apparatuses such as printers, multifunction peripherals, and facsimile machines are provided with a developing device, and there are some that use a two-component developer composed of a toner and a carrier as the developer. Inside the developing device in which the two-component developer is used, an agitating chamber for agitating and circulating the two-component developer for development and an agitating and conveying member for agitating and conveying the developer are provided. The stirring and conveying member is formed with a spiral stirring blade along the axial direction of the rotation shaft, and the stirring and conveying member rotates around the axis in the stirring chamber. The toner and the carrier are conveyed in the agitating chamber by the agitating and conveying member, and the carrier and the toner are mixed and agitated in the meantime to charge the toner.

前記２成分現像剤のトナーとキャリアとの混合比は、トナーの適切な帯電電位を得て、良好な画像を得るために、適切な範囲に設定されることが必要である。このため、トナー濃度を検出するトナー濃度センサを攪拌室に設け、攪拌室内のトナー濃度を連続的に検出するようにした現像装置が公知である（例えば、特許文献１参照。）。   The mixing ratio of the toner and carrier of the two-component developer needs to be set in an appropriate range in order to obtain an appropriate charging potential of the toner and obtain a good image. For this reason, a developing device is known in which a toner concentration sensor for detecting the toner concentration is provided in the stirring chamber so that the toner concentration in the stirring chamber is continuously detected (see, for example, Patent Document 1).

前記従来の現像装置によれば、現像によってトナーを消費することにより、キャリアに対するトナーの割合が減少して、トナー濃度が所定の基準値より低下したことが検出されると、トナー室から攪拌室内に新たなトナーが適宜補給される。新たに補給されたトナーは、攪拌室内の既存の２成分現像剤とともに攪拌搬送部材によって混合・攪拌され、逐次現像に供される。前記トナー濃度センサは、現像剤中のキャリアの透磁率を検出する磁気センサであり、攪拌室の壁面にセンサ面が設けられており、磁気センサの出力からトナー濃度を検出している。   According to the conventional developing device, when it is detected that the toner is consumed by development and the ratio of the toner to the carrier decreases and the toner concentration is lower than the predetermined reference value, New toner is replenished as needed. The newly replenished toner is mixed and agitated by the agitating and conveying member together with the existing two-component developer in the agitating chamber, and is successively subjected to development. The toner concentration sensor is a magnetic sensor that detects the magnetic permeability of the carrier in the developer. A sensor surface is provided on the wall surface of the stirring chamber, and the toner concentration is detected from the output of the magnetic sensor.

特開平５−３２３７９４号公報JP-A-5-323794

しかしながら、上記従来の現像装置では、攪拌搬送部材が回転することによって２成分現像剤が螺旋状の攪拌羽根により送り出されるため、２成分現像剤の送り量には、攪拌羽根の送り速度やピッチなどに起因した周期的なうねりや脈打ちなどの波がある。このため、トナー濃度センサのセンサ面を通過する２成分現像剤の量が変動し、これが磁気センサの読取、出力を不安定にさせて出力の周期的変化、いわゆるリップルが生じ、その結果、トナー補給量に過不足が生じ、トナーの帯電過多あるいは不足が生じるという問題がある。   However, in the conventional developing device, the two-component developer is sent out by the spiral stirring blades by rotating the stirring and conveying member. Therefore, the feed amount of the two-component developer includes the feed speed and pitch of the stirring blades, etc. There are waves such as periodic swells and pulsations caused by. For this reason, the amount of the two-component developer passing through the sensor surface of the toner density sensor fluctuates, which causes the reading and output of the magnetic sensor to become unstable, resulting in periodic changes in output, so-called ripples. There is a problem that the replenishment amount becomes excessive or insufficient, and the toner is excessively charged or insufficient.

本発明は前記課題に鑑みてなされたものであり、トナー濃度センサの検出域を通過する２成分現像剤の量のばらつきを抑え、トナー濃度センサの出力を安定させることにより、適切なトナー補給を行い、トナーの帯電を適切に行うようにした現像装置の提供を目的とする。   The present invention has been made in view of the above-described problems, and suppresses variations in the amount of the two-component developer that passes through the detection area of the toner density sensor and stabilizes the output of the toner density sensor, thereby providing appropriate toner replenishment. An object of the present invention is to provide a developing device that performs charging of toner appropriately.

本発明の解決しようとする課題は以上の如くであり、次にこの課題を解決するための手段を説明する。   The problem to be solved by the present invention is as described above. Next, means for solving the problem will be described.

即ち、請求項１に記載の発明では、トナーとキャリアとからなる２成分現像剤を用いる現像装置であって、
前記２成分現像剤を攪拌及び循環させて現像に供する攪拌室と、
回転軸の軸方向に沿って螺旋状の撹拌羽根が形成され、前記攪拌室内で軸周りに回転することにより、攪拌室内の２成分現像剤を攪拌及び搬送する攪拌搬送部材と、
前記攪拌室に設けられ、前記攪拌室内で攪拌及び搬送される２成分現像剤のトナー濃度を検出するトナー濃度センサと、
前記攪拌搬送部材の回転軸の周囲であって、かつ前記トナー濃度センサの検出域に形成され、攪拌搬送部材の回転軸からの半径方向距離が一定に形成された規制面を有する規制部材と、
を備え、
前記攪拌室の内面と前記規制面との間に形成される一定間隔の間隙を２成分現像剤が通過する検出用流路とし、前記検出用流路の断面積を、攪拌室内の他の位置における流路の断面積より小として、トナー濃度センサの検出域を通過する２成分現像剤の量を一定としたことを特徴とする現像装置とした。 That is, the invention according to claim 1 is a developing device using a two-component developer comprising a toner and a carrier,
A stirring chamber for stirring and circulating the two-component developer for development,
A stirring and conveying member for stirring and conveying the two-component developer in the stirring chamber by forming a spiral stirring blade along the axial direction of the rotation shaft and rotating around the axis in the stirring chamber;
A toner concentration sensor that is provided in the stirring chamber and detects the toner concentration of a two-component developer stirred and conveyed in the stirring chamber;
A regulating member having a regulating surface formed around the rotation axis of the stirring and conveying member and in a detection area of the toner density sensor, and having a constant radial distance from the rotating shaft of the stirring and conveying member;
With
A detection channel through which the two-component developer passes is formed at a constant interval formed between the inner surface of the stirring chamber and the regulating surface, and the cross-sectional area of the detection channel is set to another position in the stirring chamber. The developing device is characterized in that the amount of the two-component developer passing through the detection area of the toner density sensor is constant so as to be smaller than the cross-sectional area of the flow path.

請求項２に記載の発明では、請求項１に記載の発明において、トナーとキャリアとからなる２成分現像剤を用いる現像装置であって、前記規制部材は円柱状であることを特徴とする現像装置とした。   According to a second aspect of the present invention, in the first aspect of the present invention, the developing device uses a two-component developer composed of a toner and a carrier, and the regulating member has a cylindrical shape. The device.

請求項３に記載の発明では、請求項１または２のいずれか１項に記載の発明において、トナーとキャリアとからなる２成分現像剤を用いる現像装置であって、
２成分現像剤の搬送方向の上流側に、前記規制面から連続する案内面が形成され、前記案内面は、前記攪拌搬送部材の回転軸の周囲に、攪拌搬送部材の回転軸からの半径方向距離を搬送方向上流側から下流側に向けて漸次増大するように形成されていることを特徴とする現像装置とした。 The invention according to claim 3 is the developing device according to any one of claims 1 or 2, wherein the developing device uses a two-component developer composed of a toner and a carrier.
A guide surface continuous from the regulation surface is formed on the upstream side in the transport direction of the two-component developer, and the guide surface is arranged around the rotation shaft of the stirring and transporting member in the radial direction from the rotation shaft of the stirring and transporting member. The developing device is characterized in that the distance is gradually increased from the upstream side to the downstream side in the transport direction.

本発明の効果として、以下に示すような効果を奏する。   As effects of the present invention, the following effects can be obtained.

請求項１に記載の発明によれば、トナー濃度センサの検出域において攪拌搬送部材の螺旋状の攪拌羽根を無くし、その代わりに攪拌搬送部材の回転軸からの半径方向距離を一定とした規制面を有する規制部材を設け、攪拌室の内面と規制面との間に形成される一定間隔の間隙を２成分現像剤が通過する検出用流路とする。そして、前記検出用流路の断面積を、攪拌室内の他の位置における流路の断面積より小として、トナー濃度センサの検出域を通過する２成分現像剤の量を一定としている。このため、検出用流路では、攪拌羽根の送り速度やピッチなどに起因した２成分現像剤の量の周期的なうねりや脈打ちなどの波が抑えられ、前記トナー濃度センサの検出域を通過する２成分現像剤の量のばらつきが抑えられる。よって、透磁率のばらつきを抑え、トナー濃度センサの出力を安定させることができ、適切なトナー補給を行って、トナーの帯電を適切に行うことができる。   According to the first aspect of the present invention, the spiral stirring blades of the stirring / conveying member are eliminated in the detection area of the toner concentration sensor, and instead, the regulation surface in which the radial distance from the rotating shaft of the stirring / transporting member is constant. And a detection flow path through which the two-component developer passes through a gap formed between the inner surface of the stirring chamber and the restriction surface. The cross-sectional area of the detection flow path is smaller than the cross-sectional area of the flow path at other positions in the stirring chamber, and the amount of the two-component developer passing through the detection area of the toner concentration sensor is constant. For this reason, in the detection flow path, waves such as periodic undulation and pulsation of the amount of the two-component developer due to the feed speed and pitch of the stirring blades are suppressed, and the detection flow path passes through the detection area of the toner concentration sensor. Variation in the amount of the two-component developer can be suppressed. Therefore, variation in magnetic permeability can be suppressed, the output of the toner density sensor can be stabilized, toner can be appropriately charged, and toner can be charged appropriately.

請求項２に記載の発明によれば、規制部材を円柱状とすることにより、規制部材の側面部を、攪拌搬送部材の回転軸からの半径方向距離が一定に形成された規制面とすることができる。攪拌室の内面と規制面との間に形成される一定間隔の間隙は２成分現像剤が通過する検出用流路となり、前記検出用流路の断面積を、攪拌室内の他の位置における流路の断面積より小として、トナー濃度センサの検出域を通過する２成分現像剤の量を一定としている。このため、検出用流路では、攪拌羽根の送り速度やピッチなどに起因した２成分現像剤の量の周期的なうねりや脈打ちなどの波が抑えられ、前記トナー濃度センサの検出域を通過する２成分現像剤の量のばらつきが抑えられる。よって、透磁率のばらつきを抑え、トナー濃度センサの出力を安定させることができ、適切なトナー補給を行って、トナーの帯電を適切に行うことができる。   According to the invention described in claim 2, the side surface portion of the regulating member is formed as a regulating surface having a constant radial distance from the rotating shaft of the stirring and conveying member by forming the regulating member in a columnar shape. Can do. A gap formed between the inner surface of the stirring chamber and the regulating surface is a detection flow path through which the two-component developer passes, and the cross-sectional area of the detection flow path is a flow at another position in the stirring chamber. The amount of the two-component developer passing through the detection area of the toner density sensor is made constant so as to be smaller than the cross-sectional area of the path. For this reason, in the detection flow path, waves such as periodic undulation and pulsation of the amount of the two-component developer due to the feed speed and pitch of the stirring blades are suppressed, and the detection flow path passes through the detection area of the toner concentration sensor. Variation in the amount of the two-component developer can be suppressed. Therefore, variation in magnetic permeability can be suppressed, the output of the toner density sensor can be stabilized, toner can be appropriately charged, and toner can be charged appropriately.

請求項３に記載の発明によれば、２成分現像剤の搬送方向の上流側に、前記規制面から連続する案内面が形成され、前記案内面は、前記攪拌搬送部材の回転軸の周囲に、攪拌搬送部材の回転軸からの半径方向距離を搬送方向上流側から下流側に向けて漸次増大するように形成されていることにより、案内面の部分では、搬送方向上流側から下流に向けて、２成分現像剤が通過する流路が漸次狭くなっていき、連続する規制面に円滑に案内される。このため、規制面における流路の断面積と、攪拌羽根が形成されている流路の断面積との変化が、案内面によって緩やかに変化することとなり、規制面の上流部において２成分現像剤の停滞を生じにくくすることができる。   According to the third aspect of the present invention, a guide surface continuous from the restriction surface is formed on the upstream side in the transport direction of the two-component developer, and the guide surface is around the rotation shaft of the stirring transport member. The radial distance from the rotating shaft of the agitating / conveying member is formed so as to gradually increase from the upstream side to the downstream side in the conveying direction, so that at the guide surface portion, from the upstream side in the conveying direction toward the downstream side. The flow path through which the two-component developer passes is gradually narrowed and smoothly guided to the continuous regulation surface. For this reason, the change in the cross-sectional area of the flow path on the regulation surface and the cross-sectional area of the flow path where the stirring blades are formed gradually changes depending on the guide surface, and the two-component developer in the upstream portion of the regulation surface Can be made difficult to occur.

次に、発明の実施の形態について図を用いて説明する。   Next, embodiments of the invention will be described with reference to the drawings.

本発明の実施例１に係る現像装置について、図を用いて説明する。図１は本実施例の現像装置を含む画像形成装置１１の全体的な構成を示した断面図、図２は現像装置としての現像器ユニット４１の平面図、図３は攪拌室４３と攪拌搬送部材４４の平面簡略図、図４は図３の４−４線における端面図である。   A developing device according to Embodiment 1 of the present invention will be described with reference to the drawings. FIG. 1 is a cross-sectional view showing an overall configuration of an image forming apparatus 11 including a developing device of the present embodiment, FIG. 2 is a plan view of a developing unit 41 as a developing device, and FIG. FIG. 4 is a simplified plan view of the member 44, and FIG. 4 is an end view taken along line 4-4 of FIG.

まず、本実施例の現像装置を含む画像形成装置１１の全体構成について説明すると、図１に示すように、画像形成装置１１は、給紙カセット１２の上方に配置され、給紙カセット１２から繰り込まれた記録紙上に画像情報を顕像化したトナー画像が転写され、トナー画像が定着された記録紙が、画像形成装置１１の上部に設けられる排紙トレイ１３に主搬送経路１４を経て排出されるように構成されている。また、主搬送経路１４の外側には両面印刷時の反転経路１５が形成され、この反転経路１５が該主搬送経路１４と分岐・合流する構成とされている。この主搬送経路１４に沿って、感光ドラムユニット２１、露光器３１、現像装置としての現像器ユニット４１及び定着器ユニット７１等が配置されている。   First, the overall configuration of the image forming apparatus 11 including the developing device of this embodiment will be described. As shown in FIG. 1, the image forming apparatus 11 is disposed above the paper feed cassette 12 and is fed from the paper feed cassette 12. A toner image in which image information is visualized is transferred onto the inserted recording paper, and the recording paper on which the toner image is fixed is discharged to a paper discharge tray 13 provided at the upper part of the image forming apparatus 11 via the main conveyance path 14. It is configured to be. Further, a reversing path 15 for duplex printing is formed outside the main transport path 14, and the reversing path 15 branches and merges with the main transport path 14. A photosensitive drum unit 21, an exposure device 31, a developing device unit 41 as a developing device, a fixing device unit 71, and the like are arranged along the main transport path 14.

前記感光ドラムユニット２１は、図１に示すように、記録紙に接触してトナーを転写する感光体ドラム２２と、感光体ドラム２２の表面を帯電させる帯電器２３と、感光体ドラム２２の表面をクリーニングするクリーニング装置２４等とを備えている。この感光ドラムユニット２１の感光体ドラム２２の表面に静電潜像が形成される。   As shown in FIG. 1, the photosensitive drum unit 21 includes a photosensitive drum 22 that contacts a recording sheet and transfers toner, a charger 23 that charges the surface of the photosensitive drum 22, and a surface of the photosensitive drum 22. And a cleaning device 24 for cleaning. An electrostatic latent image is formed on the surface of the photosensitive drum 22 of the photosensitive drum unit 21.

前記露光器３１は、図１に示すように、感光体ドラム２２の斜下方に配設されている。本実施例では、露光ヘッドとしてＬＥＤヘッドを用いた固定走査型のものが配設されている。ＬＥＤヘッドが、前記帯電器２３によって帯電された感光体ドラム２２の外周面にデジタル化された画像情報に基づいて像露光することによって、感光体ドラム２２の外周面に静電潜像が形成される。   As shown in FIG. 1, the exposure device 31 is disposed obliquely below the photosensitive drum 22. In this embodiment, a fixed scanning type using an LED head as an exposure head is provided. The LED head performs image exposure on the outer peripheral surface of the photosensitive drum 22 charged by the charger 23 based on the digitized image information, whereby an electrostatic latent image is formed on the outer peripheral surface of the photosensitive drum 22. The

前記現像装置としての現像器ユニット４１は、図１に示すように、ケーシング４２、攪拌室４３、攪拌搬送部材４４、現像ローラ５４、搬送ローラ５５が備えられている。この現像器ユニット４１では、現像ローラ５４の磁力により２成分現像剤８１が現像ローラ５４の外周面に吸着・担持されて磁気ブラシが形成される。２成分現像剤８１は搬送ローラ５５により現像ローラ５４に供給される。現像ローラ５４は、図１において時計回りへ回転され、現像ローラ５４の外周面に担持されたブラシ状の２成分現像剤８１が感光体ドラム２２との間に移動される。そして、現像ローラ５４の外周面に積層されたキャリアに付着したトナーは、現像ローラ５４と感光体ドラム２２の静電潜像との間に形成される電界によって、感光体ドラム２２の静電潜像の方向に移動してトナー現像される。   As shown in FIG. 1, the developing device unit 41 as the developing device includes a casing 42, a stirring chamber 43, a stirring and conveying member 44, a developing roller 54, and a conveying roller 55. In the developing unit 41, the two-component developer 81 is attracted and carried on the outer peripheral surface of the developing roller 54 by the magnetic force of the developing roller 54 to form a magnetic brush. The two-component developer 81 is supplied to the developing roller 54 by the conveyance roller 55. The developing roller 54 is rotated clockwise in FIG. 1, and the brush-like two-component developer 81 carried on the outer peripheral surface of the developing roller 54 is moved between the photosensitive drum 22. The toner adhering to the carrier laminated on the outer peripheral surface of the developing roller 54 is electrostatically latent on the photosensitive drum 22 due to an electric field formed between the developing roller 54 and the electrostatic latent image on the photosensitive drum 22. The toner is developed by moving in the direction of the image.

前記定着器ユニット７１は、図１に示すように、ヒートローラ７２と、ヒートローラ７２の外周面に圧接するように主搬送経路１４を挟んで配設されたプレスローラ７３等とからなるユニット体として構成されている。定着器ユニット７１では、ヒートローラ７２とプレスローラ７３とのニップ部にトナー転写された記録紙が送り込まれて加熱・加圧され、記録紙上のトナー画像が定着される。   As shown in FIG. 1, the fixing unit 71 is a unit body including a heat roller 72 and a press roller 73 and the like disposed with the main conveyance path 14 interposed therebetween so as to be in pressure contact with the outer peripheral surface of the heat roller 72. It is configured as. In the fixing unit 71, the recording paper on which toner is transferred is sent to the nip portion between the heat roller 72 and the press roller 73 and is heated and pressurized to fix the toner image on the recording paper.

次に、現像装置としての現像器ユニット４１について詳細に説明する。図１に示すように、前記ケーシング４２は、内部に攪拌室４３が形成されるとともに、現像ローラ５４、攪拌搬送部材４４、搬送ローラ５５等を回動可能に支持する部分である。感光体ドラム２２に対向する側が開口され、開口された部分には、現像ローラ５４がその外周面を感光体ドラム２２の外周面に対向させて配置されている。   Next, the developing unit 41 as a developing device will be described in detail. As shown in FIG. 1, the casing 42 is a portion in which a stirring chamber 43 is formed, and a developing roller 54, a stirring and conveying member 44, a conveying roller 55 and the like are rotatably supported. The side facing the photosensitive drum 22 is opened, and the developing roller 54 is disposed in the opened portion with the outer peripheral surface thereof facing the outer peripheral surface of the photosensitive drum 22.

前記攪拌室４３は、ケーシング４２内部に形成され、磁性のキャリアと非磁性のトナーとから成る２成分現像剤８１を収容し、２成分現像剤８１を攪拌及び循環させて現像に供する部分である。図２に示すように、攪拌室４３の上面のケーシング４２には平面視略矩形状に開口部４７が開口されており、この開口部４７を覆うようにしてトップカバー（図示せず）が開閉自在に取り付けられている。図２はトップカバーを外した状態を示している。図３に示すように、攪拌室４３の内部には攪拌室４３より短い隔壁４８が形成され、攪拌室４３が２区画に区分されているとともに、隔壁４８の両端部で相互に連通している。攪拌室４３を隔壁４８の両端部で連通させていることにより、２成分現像剤８１は前記連通した部分を通過して攪拌室４３内を循環できるようにしている。また、攪拌室４３に連通するようにトナー供給口４９が形成されており、トナー供給口４９は開閉自在の蓋体（図示せず）で閉鎖されている。現像器ユニット４１を画像形成装置１１に装着すると（図１参照）、前記蓋体が開放されてトナー供給口４９にトナー室５６が連結され、必要に応じてトナー室５６から攪拌室４３にトナーが供給される。   The agitating chamber 43 is a portion formed inside the casing 42, which contains a two-component developer 81 made of a magnetic carrier and non-magnetic toner, and agitates and circulates the two-component developer 81 for development. . As shown in FIG. 2, an opening 47 is opened in a substantially rectangular shape in plan view in the casing 42 on the upper surface of the stirring chamber 43, and a top cover (not shown) is opened and closed so as to cover the opening 47. It is attached freely. FIG. 2 shows a state in which the top cover is removed. As shown in FIG. 3, a partition wall 48 shorter than the stirring chamber 43 is formed inside the stirring chamber 43, and the stirring chamber 43 is divided into two sections and communicates with both ends of the partition wall 48. . By allowing the stirring chamber 43 to communicate with both ends of the partition wall 48, the two-component developer 81 can pass through the communicating portion and circulate in the stirring chamber 43. Further, a toner supply port 49 is formed so as to communicate with the stirring chamber 43, and the toner supply port 49 is closed by an openable / closable lid (not shown). When the developing device unit 41 is attached to the image forming apparatus 11 (see FIG. 1), the lid is opened and the toner chamber 56 is connected to the toner supply port 49, and the toner chamber 56 and the agitation chamber 43 as necessary. Is supplied.

攪拌搬送部材４４は、前記攪拌室４３内の２成分現像剤８１を攪拌及び搬送する部材である。図２に示すように、攪拌搬送部材４４は、前記攪拌室４３内の各区画にそれぞれ配置されている。図３に示すように、各攪拌搬送部材４４には、回転軸４６の軸方向に沿って所定のピッチで螺旋状に形成した攪拌羽根４５が設けられているとともに、後記トナー濃度センサのセンサ面６２に対向する検出域６３（図４参照）には、攪拌羽根４５の代わりに後記規制部材５１が設けられている。駆動手段（図示せず）により２本の攪拌搬送部材４４はそれぞれ軸周りに回転するが、回転方向は相互に反対方向に回転するものとされており、トナー供給口４９から補給されたトナーはキャリアとともに図示矢印方向に循環する。トナーとキャリアは攪拌室４３内を循環しながら攪拌され、摩擦帯電されて、静電気により互いに吸着される。   The agitating and conveying member 44 is a member that agitates and conveys the two-component developer 81 in the agitating chamber 43. As shown in FIG. 2, the stirring and conveying member 44 is disposed in each section in the stirring chamber 43. As shown in FIG. 3, each stirring and conveying member 44 is provided with stirring blades 45 formed in a spiral shape at a predetermined pitch along the axial direction of the rotation shaft 46, and the sensor surface of the toner density sensor described later. In the detection area 63 (see FIG. 4) facing 62, a postscript restricting member 51 is provided instead of the stirring blade 45. The two agitating / conveying members 44 are rotated about their respective axes by driving means (not shown), but the rotation directions are opposite to each other. The toner replenished from the toner supply port 49 is Circulates with the carrier in the direction of the arrow shown. The toner and the carrier are stirred while circulating in the stirring chamber 43, are frictionally charged, and are adsorbed to each other by static electricity.

トナー濃度センサとしての磁気センサ６１は、２成分現像剤中のキャリアの透磁率を検出してトナー濃度を検出するものである。図３に示すように、磁気センサ６１のセンサ面６２は、攪拌室４３の側面であって、前記トナー供給口４９からやや離隔した位置に設けられている。トナー濃度の変化は、トナーとキャリアの混合比率の変化であり、これは２成分現像剤８１の透磁率の変化として現れる。磁気センサ６１は、センサ面６２に対向する検出域６３（図４参照）を通過する２成分現像剤８１の透磁率の変化を電圧の変化として連続的に検出している。   A magnetic sensor 61 as a toner concentration sensor detects the toner concentration by detecting the magnetic permeability of the carrier in the two-component developer. As shown in FIG. 3, the sensor surface 62 of the magnetic sensor 61 is a side surface of the stirring chamber 43 and is provided at a position slightly separated from the toner supply port 49. The change in the toner density is a change in the mixing ratio of the toner and the carrier, and this appears as a change in the magnetic permeability of the two-component developer 81. The magnetic sensor 61 continuously detects a change in magnetic permeability of the two-component developer 81 passing through a detection area 63 (see FIG. 4) facing the sensor surface 62 as a change in voltage.

規制部材５１は、磁気センサ６１の検出域６３に規制面５０を配置して、攪拌室４３の内面と規制面５０との間に検出用流路５２を形成する部材である。図３、図４に示すように、規制部材５１は、外形が円柱状であり、前記攪拌搬送部材４４の回転軸４６と一体に形成されており、設置位置は、前記磁気センサ６１の検出域６３である。この部分には攪拌羽根４５は形成されておらず、攪拌羽根４５の代わりに規制部材５１が設けられる。また、規制部材５１は、円柱の中心軸と攪拌搬送部材４４の回転軸４６の中心が一致するように形成されている。規制面５０は規制部材５１の側面部に形成されており、攪拌搬送部材４４の回転軸４６から規制面５０までの半径方向距離は一定である。このため、図４に示すように、前記攪拌室４３の内面と規制面５０の間に形成される検出用流路５２は、攪拌搬送部材４４の回転角度に関わらず一定となる。   The regulating member 51 is a member that forms the detection flow path 52 between the inner surface of the stirring chamber 43 and the regulating surface 50 by arranging the regulating surface 50 in the detection area 63 of the magnetic sensor 61. As shown in FIGS. 3 and 4, the regulating member 51 has a cylindrical outer shape and is formed integrally with the rotating shaft 46 of the stirring and conveying member 44, and the installation position is within the detection area of the magnetic sensor 61. 63. The stirring blade 45 is not formed in this portion, and a regulating member 51 is provided instead of the stirring blade 45. In addition, the regulating member 51 is formed so that the center axis of the cylinder coincides with the center of the rotation shaft 46 of the stirring and conveying member 44. The regulating surface 50 is formed on the side surface of the regulating member 51, and the radial distance from the rotation shaft 46 of the stirring and conveying member 44 to the regulating surface 50 is constant. For this reason, as shown in FIG. 4, the detection flow path 52 formed between the inner surface of the stirring chamber 43 and the regulating surface 50 is constant regardless of the rotation angle of the stirring and conveying member 44.

図４に示すように、磁気センサ６１の検出域６３に形成された検出用流路５２の断面積（図示右側）と、攪拌室４３内の他の位置における流路の断面積（図示左側）を比較すると、検出用流路５２の断面積は、他の位置における流路の断面積より小となっており、２成分現像剤８１は磁気センサ６１のセンサ面６２の位置より高い位置まで流路の空間を満たしながら、トナー濃度センサの検出域６３を通過する。このため、攪拌羽根４５の送り速度やピッチなどに起因した２成分現像剤８１量の周期的なうねりや脈打ちなどの波は、検出用流路５２では抑えられ、磁気センサ６１の検出域６３を通過する２成分現像剤８１の量は一定となる。   As shown in FIG. 4, the cross-sectional area of the detection flow path 52 formed in the detection area 63 of the magnetic sensor 61 (right side in the figure) and the cross-sectional area of the flow path in other positions in the stirring chamber 43 (left side in the figure). In comparison, the cross-sectional area of the detection flow path 52 is smaller than the cross-sectional area of the flow path at other positions, and the two-component developer 81 flows to a position higher than the position of the sensor surface 62 of the magnetic sensor 61. It passes through the detection area 63 of the toner density sensor while filling the space of the road. For this reason, waves such as periodic undulation and pulsation of the amount of the two-component developer 81 due to the feed speed and pitch of the stirring blade 45 are suppressed in the detection flow path 52, and the detection area 63 of the magnetic sensor 61 is controlled. The amount of the two-component developer 81 that passes through is constant.

尚、攪拌搬送部材４４の回転軸４６から規制面５０までの半径方向距離により、検出用流路５２の断面積が決定されるため、検出用流路５２の断面積が２成分現像剤８１の量に応じて適切な断面積となるように、半径方向距離を設定するものとする。また、規制部材５１の長手方向の長さは、少なくとも磁気センサ６１のセンサ面６２より長く形成するようにし、磁気センサ６１の検出域６３を通過する２成分現像剤８１量が一定となるようにする。   The cross-sectional area of the detection flow path 52 is determined by the radial distance from the rotating shaft 46 of the stirring and conveying member 44 to the restriction surface 50, so that the cross-sectional area of the detection flow path 52 is equal to that of the two-component developer 81. The radial distance is set so as to obtain an appropriate cross-sectional area according to the amount. The length of the regulating member 51 in the longitudinal direction is at least longer than the sensor surface 62 of the magnetic sensor 61 so that the amount of the two-component developer 81 passing through the detection area 63 of the magnetic sensor 61 is constant. To do.

以上説明した本実施例に係る現像装置によれば、前記検出用流路５２の断面積を、攪拌室４３内の他の位置における流路の断面積より小として、磁気センサ６１の検出域６３を通過する２成分現像剤８１の量を一定としているため、攪拌羽根４５の送り速度やピッチなどに起因した２成分現像剤８１量の周期的なうねりや脈打ちなどの波が抑えられ、前記磁気センサ６１の検出域６３を通過する２成分現像剤８１量のばらつきが抑えられる。よって、透磁率のばらつきを抑え、磁気センサ６１の出力を安定させることができ、適切なトナー補給を行って、トナーの帯電を適切に行うことができる。   According to the developing device according to the present embodiment described above, the detection area 63 of the magnetic sensor 61 is set so that the cross-sectional area of the detection flow path 52 is smaller than the cross-sectional area of the flow path at other positions in the stirring chamber 43. Since the amount of the two-component developer 81 passing through is constant, waves such as periodic undulation and pulsation of the amount of the two-component developer 81 due to the feed speed and pitch of the stirring blade 45 are suppressed, and the magnetic Variation in the amount of the two-component developer 81 passing through the detection area 63 of the sensor 61 is suppressed. Therefore, variation in magnetic permeability can be suppressed, the output of the magnetic sensor 61 can be stabilized, toner can be appropriately charged, and toner can be charged appropriately.

次に、本発明の実施例２に係る現像装置について説明する。実施例２では、前記規制面５０に連続する案内面５３が形成されている点が実施例１に係る現像装置と大きく異なっている。実施例１と同一部分は同一符号を付して詳しい説明は省略する。   Next, a developing device according to Embodiment 2 of the present invention will be described. The second embodiment is greatly different from the developing device according to the first embodiment in that a guide surface 53 that is continuous with the restriction surface 50 is formed. The same parts as those in the first embodiment are denoted by the same reference numerals, and detailed description thereof is omitted.

図５は実施例２に係る現像装置の攪拌室４３と攪拌搬送部材４４の平面簡略図である。図５に示すように、２成分現像剤８１の搬送方向の上流側に、前記規制面５０から連続する案内面５３を形成する。案内面５３は、攪拌室４３の内面と規制面５０との間に形成される検出用流路５２に、２成分現像剤８１を円滑に導入するものである。案内面５３の外形は、略截頭円錐形状であり、前記攪拌搬送部材４４の回転軸４６の周囲に、攪拌搬送部材４４の回転軸４６からの半径方向距離を搬送方向上流側から下流側に向けて漸次増大するように形成される。このため、案内面５３と攪拌室４３の内面との間に形成される２成分現像剤８１の流路は、搬送方向上流側から下流に向けて、２成分現像剤８１が通過する流路が漸次狭くなっていく形状である。尚、案内面５３は、前記規制面５０に円滑に連続するように形成される。   FIG. 5 is a schematic plan view of the stirring chamber 43 and the stirring and conveying member 44 of the developing device according to the second embodiment. As shown in FIG. 5, a guide surface 53 continuous from the regulation surface 50 is formed on the upstream side in the transport direction of the two-component developer 81. The guide surface 53 smoothly introduces the two-component developer 81 into the detection flow path 52 formed between the inner surface of the stirring chamber 43 and the regulation surface 50. The outer shape of the guide surface 53 is substantially frustoconical, and the radial distance from the rotating shaft 46 of the stirring and conveying member 44 is changed from the upstream side to the downstream side in the conveying direction around the rotating shaft 46 of the stirring and conveying member 44. It forms so that it may increase gradually toward it. Therefore, the flow path of the two-component developer 81 formed between the guide surface 53 and the inner surface of the stirring chamber 43 is a flow path through which the two-component developer 81 passes from the upstream side in the transport direction to the downstream side. The shape gradually becomes narrower. The guide surface 53 is formed so as to be smoothly continuous with the restriction surface 50.

実施例２に係る現像装置によれば、以下の効果を有する。すなわち、２成分現像剤８１の搬送方向の上流側に、前記規制面５０から円滑に連続する案内面５３が形成され、前記案内面５３は、前記攪拌搬送部材４４の回転軸４６の周囲に、攪拌搬送部材４４の回転軸４６からの半径方向距離を搬送方向上流側から下流側に向けて漸次増大するように形成されていることにより、案内面５３の部分では、搬送方向上流側から下流に向けて、２成分現像剤８１が通過する流路が漸次狭くなっていき、連続する規制面５０に円滑に案内される。このため、規制面５０における検出用流路５２の断面積と、その他の位置における流路の断面積との変化が、案内面５３によって緩やかに変化することとなり、規制面５０の上流部において２成分現像剤８１の停滞を生じにくくすることができる。   The developing device according to Embodiment 2 has the following effects. That is, on the upstream side in the transport direction of the two-component developer 81, a guide surface 53 that is smoothly continuous from the regulation surface 50 is formed, and the guide surface 53 is around the rotation shaft 46 of the stirring and transporting member 44. Since the radial distance from the rotating shaft 46 of the agitating / conveying member 44 is formed so as to gradually increase from the upstream side to the downstream side in the conveying direction, the guide surface 53 has a portion downstream from the upstream side in the conveying direction. The flow path through which the two-component developer 81 passes is gradually narrowed and smoothly guided to the continuous regulating surface 50. For this reason, the change in the cross-sectional area of the detection flow path 52 on the restriction surface 50 and the cross-sectional area of the flow path at other positions is gently changed by the guide surface 53. The stagnation of the component developer 81 can be made difficult to occur.

本発明の実施の形態は上記実施例に限定されるものではなく、例えば、円柱状の規制部材５１は攪拌搬送部材４４と一体に形成したが、これに限定されず、攪拌搬送部材４４と別体に形成した円筒状の規制部材５１を攪拌搬送部材４４に取り付けるようにしてもよい。   The embodiment of the present invention is not limited to the above-described embodiment. For example, the columnar regulating member 51 is formed integrally with the stirring and conveying member 44. However, the present invention is not limited to this. A cylindrical regulating member 51 formed on the body may be attached to the stirring and conveying member 44.

また、本実施例では、規制部材５１は円柱状としたが、これに限定されず、回転軸４６から規制面５０までの半径方向距離は、回転軸４６のある位置において、規制面５０の全周について半径距離が一定であればよく、回転軸４６の長手方向の各位置における半径距離は一定でなくてもよい。すなわち、トナー濃度センサの検出域６３を通過する２成分現像剤８１の量が、攪拌搬送部材４４の回転によって変化せず、一定であればよい。従って、規制部材５１の形状は、例えば、截頭円錐形状や、樽形、紡錘形などの形状であってもよい。   In the present embodiment, the restricting member 51 has a cylindrical shape. However, the present invention is not limited to this, and the radial distance from the rotating shaft 46 to the restricting surface 50 is the total of the restricting surface 50 at a position where the rotating shaft 46 is located. The radius distance may be constant for the circumference, and the radius distance at each position in the longitudinal direction of the rotation shaft 46 may not be constant. That is, the amount of the two-component developer 81 that passes through the detection area 63 of the toner density sensor may be constant without being changed by the rotation of the stirring and conveying member 44. Therefore, the shape of the regulating member 51 may be, for example, a truncated cone shape, a barrel shape, a spindle shape, or the like.

本実施例の現像装置を含む画像形成装置１１の全体的な構成を示した断面図。FIG. 2 is a cross-sectional view illustrating an overall configuration of an image forming apparatus 11 including a developing device according to the present exemplary embodiment. 現像装置としての現像器ユニット４１の平面図。The top view of the developing device unit 41 as a developing device. 攪拌室４３と攪拌搬送部材４４の平面簡略図。FIG. 3 is a simplified plan view of the stirring chamber 43 and the stirring and conveying member 44. 図３の４−４線における端面図。FIG. 4 is an end view taken along line 4-4 of FIG. 実施例２に係る現像装置の攪拌室４３と攪拌搬送部材４４の平面簡略図。9 is a simplified plan view of an agitating chamber 43 and an agitating and conveying member 44 of a developing device according to Embodiment 2. FIG.

符号の説明Explanation of symbols

１１ 画像形成装置
１２ 給紙カセット
１３ 排紙トレイ
１４ 主搬送経路
１５ 反転経路
２１ 感光ドラムユニット
２２ 感光体ドラム
２３ 帯電器
２４ クリーニング装置
３１ 露光器
４１ 現像装置としての現像器ユニット
４２ ケーシング
４３ 攪拌室
４４ 攪拌搬送部材
４５ 攪拌羽根
４６ 回転軸
４７ 開口部
４８ 隔壁
４９ トナー供給口
５０ 規制面
５１ 規制部材
５２ 検出用流路
５３ 案内面
５４ 現像ローラ
５５ 搬送ローラ
５６ トナー室
６１ トナー濃度センサとしての磁気センサ
６２ センサ面
６３ 検出域
７１ 定着器ユニット
７２ ヒートローラ
７３ プレスローラ
８１ ２成分現像剤 DESCRIPTION OF SYMBOLS 11 Image forming apparatus 12 Paper feed cassette 13 Paper discharge tray 14 Main conveyance path 15 Reverse path 21 Photosensitive drum unit 22 Photosensitive drum 23 Charger 24 Cleaning device 31 Exposure unit 41 Developer unit as developing device 42 Casing 43 Stirring chamber 44 Stirring Conveying member 45 Stirrer blade 46 Rotating shaft 47 Opening portion 48 Bulkhead 49 Toner supply port 50 Restricting surface 51 Restricting member 52 Detection flow channel 53 Guide surface 54 Developing roller 55 Conveying roller 56 Toner chamber 61 Magnetic sensor 62 as a toner concentration sensor 62 Sensor Surface 63 Detection area 71 Fixing unit 72 Heat roller 73 Press roller 81 Two-component developer

Claims (3)

トナーとキャリアとからなる２成分現像剤を用いる現像装置であって、
前記２成分現像剤を攪拌及び循環させて現像に供する攪拌室と、
回転軸の軸方向に沿って螺旋状の撹拌羽根が形成され、前記攪拌室内で軸周りに回転することにより、攪拌室内の２成分現像剤を攪拌及び搬送する攪拌搬送部材と、
前記攪拌室に設けられ、前記攪拌室内で攪拌及び搬送される２成分現像剤のトナー濃度を検出するトナー濃度センサと、
前記攪拌搬送部材の回転軸の周囲であって、かつ前記トナー濃度センサの検出域に形成され、攪拌搬送部材の回転軸からの半径方向距離が一定に形成された規制面を有する規制部材と、
を備え、
前記攪拌室の内面と前記規制面との間に形成される一定間隔の間隙を２成分現像剤が通過する検出用流路とし、前記検出用流路の断面積を、攪拌室内の他の位置における流路の断面積より小として、トナー濃度センサの検出域を通過する２成分現像剤の量を一定としたことを特徴とする現像装置。 A developing device using a two-component developer comprising a toner and a carrier,
A stirring chamber for stirring and circulating the two-component developer for development,
A stirring and conveying member for stirring and conveying the two-component developer in the stirring chamber by forming a spiral stirring blade along the axial direction of the rotation shaft and rotating around the axis in the stirring chamber;
A toner concentration sensor that is provided in the stirring chamber and detects the toner concentration of a two-component developer stirred and conveyed in the stirring chamber;
A regulating member having a regulating surface formed around the rotation axis of the stirring and conveying member and in a detection area of the toner density sensor, and having a constant radial distance from the rotating shaft of the stirring and conveying member;
With
A detection channel through which the two-component developer passes is formed at a constant interval formed between the inner surface of the stirring chamber and the regulating surface, and the cross-sectional area of the detection channel is set to another position in the stirring chamber. A developing device characterized in that the amount of the two-component developer passing through the detection area of the toner density sensor is constant so as to be smaller than the cross-sectional area of the flow path. トナーとキャリアとからなる２成分現像剤を用いる現像装置であって、
前記規制部材は円柱状であることを特徴とする請求項１に記載の現像装置。 A developing device using a two-component developer comprising a toner and a carrier,
The developing device according to claim 1, wherein the regulating member has a cylindrical shape. トナーとキャリアとからなる２成分現像剤を用いる現像装置であって、
２成分現像剤の搬送方向の上流側に、前記規制面から連続する案内面が形成され、前記案内面は、前記攪拌搬送部材の回転軸の周囲に、攪拌搬送部材の回転軸からの半径方向距離を搬送方向上流側から下流側に向けて漸次増大するように形成されていることを特徴とする請求項１または２のいずれか１項に記載の現像装置。 A developing device using a two-component developer comprising a toner and a carrier,
A guide surface continuous from the regulation surface is formed on the upstream side in the transport direction of the two-component developer, and the guide surface is arranged around the rotation shaft of the stirring and transporting member in the radial direction from the rotation shaft of the stirring and transporting member. The developing device according to claim 1, wherein the developing device is formed so as to gradually increase the distance from the upstream side toward the downstream side in the transport direction.
JP2006127620A 2006-05-01 2006-05-01 Developing device Pending JP2007298824A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
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Application Number Priority Date Filing Date Title
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Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN109212932A (en) * 2017-07-03 2019-01-15 富士施乐株式会社 Image forming apparatus and developing apparatus
JP2021063890A (en) * 2019-10-11 2021-04-22 コニカミノルタ株式会社 Developing device and image forming apparatus

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN109212932A (en) * 2017-07-03 2019-01-15 富士施乐株式会社 Image forming apparatus and developing apparatus
JP2019015758A (en) * 2017-07-03 2019-01-31 富士ゼロックス株式会社 Image forming apparatus and developing device
CN109212932B (en) * 2017-07-03 2022-06-03 富士胶片商业创新有限公司 Image forming apparatus and developing device
JP2021063890A (en) * 2019-10-11 2021-04-22 コニカミノルタ株式会社 Developing device and image forming apparatus
JP7363337B2 (en) 2019-10-11 2023-10-18 コニカミノルタ株式会社 Developing device and image forming device

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