JPS63291072A - Developing device - Google Patents
Developing deviceInfo
- Publication number
- JPS63291072A JPS63291072A JP12680387A JP12680387A JPS63291072A JP S63291072 A JPS63291072 A JP S63291072A JP 12680387 A JP12680387 A JP 12680387A JP 12680387 A JP12680387 A JP 12680387A JP S63291072 A JPS63291072 A JP S63291072A
- Authority
- JP
- Japan
- Prior art keywords
- magnetic poles
- magnetic
- toner concentration
- magnet
- roller
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
- 238000001514 detection method Methods 0.000 description 12
- 238000010586 diagram Methods 0.000 description 2
- 230000000630 rising effect Effects 0.000 description 2
- 238000003756 stirring Methods 0.000 description 2
- 239000002131 composite material Substances 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 230000035699 permeability Effects 0.000 description 1
- 108091008695 photoreceptors Proteins 0.000 description 1
- 230000001105 regulatory effect Effects 0.000 description 1
- 230000032258 transport Effects 0.000 description 1
Landscapes
- Magnetic Brush Developing In Electrophotography (AREA)
- Dry Development In Electrophotography (AREA)
Abstract
Description
【発明の詳細な説明】
（産業上の利用分野）
本発明は静電複写機やファクシミリ等の画像形成装置に
用いられる現像装置の改良に関するものである。DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an improvement in a developing device used in an image forming apparatus such as an electrostatic copying machine or a facsimile machine.
（従来技術）
従来よりトナー濃度センサーを用いた現像装置において
センサーの設置位置は、例えば第２図に示されるように
現像ローラ３０の表面に形成される穂の高さを規制する
ためのドクターブレード３１の壁面外方に現像ローラの
回転によりドクターブレード３１に沿って上昇する現像
剤の透磁率を検知するためのコイルを内蔵する検知部３
２から構成されるセンサー３３が設けられるというもの
であった。(Prior Art) Conventionally, in a developing device using a toner density sensor, the sensor is installed at a doctor blade for regulating the height of the spike formed on the surface of the developing roller 30, for example, as shown in FIG. A detection unit 3 has a built-in coil outside the wall surface of 31 for detecting the magnetic permeability of the developer rising along the doctor blade 31 due to the rotation of the developing roller.
A sensor 33 consisting of two sensors was provided.
（発明が解決しようとする問題点）
上記従来技術にあっては矢印で示すセンサーの検知部を
なすコイルにより生じる磁界と、点線で示す現像ローラ
の磁石による磁界が干渉しそれらの合成磁界によって生
じる電圧が出力されるためコイルのＳＮ比が極めて悪化
し正確なトナー濃度測定が困難となる。また現像ローラ
の磁石の着磁位置、磁石強度のわずかなバラツキによっ
てもセンサーにおよぼす影響が変化するために出力電圧
が変動しそれらを一定値に合わせるための組み立て調整
に時間を要し生産性が悪い。さらにセンサーはドクター
ブレードの壁面外方に設置されるゆえに、ドクターブレ
ードの壁面に沿ってセンサーの検知部まで上昇してゆく
現像剤の流動性の変化が住じた場合、センサーの検知部
と現像剤との接触状態が変化し特に接触圧が大きく変わ
るため、センサーの出力変動をきたすという不都合があ
る。(Problems to be Solved by the Invention) In the above-mentioned conventional technology, the magnetic field generated by the coil forming the detection part of the sensor, indicated by the arrow, and the magnetic field generated by the magnet of the developing roller, indicated by the dotted line, interfere with each other, and a composite magnetic field is generated by them. Since a voltage is output, the signal-to-noise ratio of the coil becomes extremely poor, making it difficult to accurately measure toner concentration. In addition, slight variations in the magnetized position and strength of the developing roller magnets can affect the sensor, resulting in fluctuations in the output voltage, which requires time to assemble and adjust to keep them at a constant value, reducing productivity. bad. Furthermore, since the sensor is installed outside the wall of the doctor blade, if there is a change in the fluidity of the developer rising along the wall of the doctor blade to the detection area of the sensor, the detection area of the sensor and the developer Since the state of contact with the agent changes, especially the contact pressure, there is a disadvantage that the output of the sensor fluctuates.
（発明の目的）
この発明は上記の問題に鑑みてなされたものであり、ト
ナー濃度検知センサーが現像ローラの磁石からの磁界に
影響されることなく正確なトナー濃度検知が可能であり
、また現像ローラの磁石位置、磁石強度のバラツキにか
かわらず正確なトナー濃度検知が可能であるために装置
の生産性が高く、さらに現像剤の流動性の変化が有って
も正確なトナー濃度検知が可能な現像装置を提供するこ
とを目的とする。(Object of the Invention) The present invention was made in view of the above problems, and provides a toner concentration detection sensor that is capable of accurately detecting toner concentration without being affected by the magnetic field from the magnet of the developing roller. Accurate toner concentration detection is possible regardless of variations in the roller magnet position or magnet strength, which increases the productivity of the device.Furthermore, accurate toner concentration detection is possible even when there are changes in developer fluidity. The purpose of the present invention is to provide a developing device.
（問題点を解決するための手段）
上記の目的を達成するために、この発明の現像装置は、
回転自在の中空円筒スリーブの内部に複数の磁極を有す
る固定磁石が配置される現像ローラを有する現像装置に
おいて、固定磁石の磁極のうち相隣る特定の２つの磁極
は同一極性を有し、同一の極性を有する磁極の間に対応
する部位にトナー濃度センザーを設けたことを特徴とす
る。(Means for Solving the Problems) In order to achieve the above object, the developing device of the present invention has the following features:
In a developing device having a developing roller in which a fixed magnet having a plurality of magnetic poles is arranged inside a rotatable hollow cylindrical sleeve, two specific adjacent magnetic poles of the fixed magnet have the same polarity and are the same. The present invention is characterized in that a toner concentration sensor is provided at a corresponding position between magnetic poles having polarity.
（作用）
トナー濃度センサーは現像ローラの磁石により発生され
る磁界の影響を受けない。(Function) The toner density sensor is not affected by the magnetic field generated by the magnet of the developing roller.
（実施例）
第１図は本発明に係る現像装置を備えた静電複写機の要
部を示し、同図において１は表面に静電潜像が形成され
る感光体ドラム、２はトナーとキャリアとからなる現像
剤が収容された現像剤容器、３は補給用トナーが収容さ
れたトナーホッパーである。上記現像剤容器２内には、
感光体ドラム１の表面と所定間隔をもって対向する現像
ローラ４と、現像剤を撹拌混合しつつ現像ローラ４に搬
送する撹拌ローラ５が配設されている。上記現像ローラ
４は図外の駆動手段によって矢符で示される時計方向に
回転駆動される回転スリーブ６を有し、その内部には磁
気ブラシを形成するための複数の磁極８が所定の間隔で
着磁されたマグネットが固定されている。(Example) Fig. 1 shows the main parts of an electrostatic copying machine equipped with a developing device according to the present invention, in which 1 is a photosensitive drum on whose surface an electrostatic latent image is formed, 2 is a toner A developer container 3 contains a developer consisting of a carrier, and a toner hopper 3 contains replenishment toner. Inside the developer container 2,
A developing roller 4 facing the surface of the photoreceptor drum 1 at a predetermined distance, and an agitating roller 5 that transports the developer to the developing roller 4 while stirring and mixing the developer are provided. The developing roller 4 has a rotating sleeve 6 which is rotationally driven in the clockwise direction indicated by an arrow by a driving means (not shown), and inside the rotating sleeve 6, a plurality of magnetic poles 8 for forming a magnetic brush are arranged at predetermined intervals. A magnetized magnet is fixed.
また磁極８のうち磁極８−２と磁極８−１とは、両磁極
間に磁界が発生しないように同極性としている。よって
感光体ドラム１に供与された後の現像剤は回転スリーブ
６の回動とともに磁極８〜２上へ移動し、次に磁極８−
１上へ移動する段階で回転スリーブ６上から剥離されて
撹拌ローラ５に向けて移動する。Further, among the magnetic poles 8, the magnetic poles 8-2 and 8-1 have the same polarity so that no magnetic field is generated between the two magnetic poles. Therefore, the developer supplied to the photosensitive drum 1 moves onto the magnetic poles 8-2 as the rotating sleeve 6 rotates, and then moves onto the magnetic poles 8-2.
1, it is peeled off from above the rotating sleeve 6 and moves toward the stirring roller 5.
そして上述した関係にある磁極８−１と８−２間の下方
における現像剤容器２の壁面にはトナー濃度センサー９
を取り付けている。更に詳しくは磁極８−１と８−２の
ほぼ中央位置下方にセンサー９のコイルを内蔵する検出
部１０が現像剤容器２の壁に嵌入されている。ここで現
像ローラ４に近接する現像剤容器２の底面２−１とそれ
に続く容器２の傾斜部２−２との成す角度θは、現像剤
の自然落下とトナー濃度センサーの検知精度の点からし
て４０″以上であることが好ましい。A toner concentration sensor 9 is provided on the wall surface of the developer container 2 below between the magnetic poles 8-1 and 8-2 having the above-mentioned relationship.
is installed. More specifically, a detection section 10 containing a built-in coil of a sensor 9 is fitted into the wall of the developer container 2 below the substantially central position of the magnetic poles 8-1 and 8-2. Here, the angle θ formed by the bottom surface 2-1 of the developer container 2 adjacent to the developing roller 4 and the sloped portion 2-2 of the container 2 following it is determined from the viewpoint of natural fall of the developer and the detection accuracy of the toner concentration sensor. It is preferable that the length is 40'' or more.
（発明の効果）
トナー濃度検知センサーが現像ローラの磁石からの磁界
に影響されることなく正確なトナー濃度検知が可能であ
る。現像ローラの磁石からの磁界に影響されることのな
い位置でトナー濃度検知を行うために現像ローラの磁石
位置、磁石強度のバラツキが有っても正確なトナー濃度
検知が可能であるために装置の生産性が高い。さらに現
像装置内を自然落下する現像剤のトナー濃度を検知する
ため、現像剤の流動性の変化があっても接触圧の変化が
少なく正確なトナー濃度検知が可能である。(Effects of the Invention) The toner concentration detection sensor can accurately detect toner concentration without being affected by the magnetic field from the magnet of the developing roller. In order to detect toner concentration at a position that is not affected by the magnetic field from the developing roller magnet, the device is capable of accurate toner concentration detection even if there are variations in the developing roller magnet position and magnet strength. productivity is high. Furthermore, since the toner concentration of the developer that naturally falls inside the developing device is detected, even if there is a change in the fluidity of the developer, there is little change in contact pressure, and accurate toner concentration detection is possible.
第１図は本発明に係る現像装置を備えた静電複写機の要
部を示す図、第２図は従来例を示す図である。
４・・・・・現像ローラ
８・・・・・磁極FIG. 1 is a diagram showing essential parts of an electrostatic copying machine equipped with a developing device according to the present invention, and FIG. 2 is a diagram showing a conventional example. 4...Developing roller 8...Magnetic pole
Claims (1)
る固定磁石が配置される現像ローラを有する現像装置に
おいて、該固定磁石の磁極のうち相隣る特定の２つの磁
極は同一極性を有し、該同一の極性を有する磁極の間に
対応する部位にトナー濃度センサーを設けたことを特徴
とする現像装置。In a developing device having a developing roller in which a fixed magnet having a plurality of magnetic poles is arranged inside a freely rotatable hollow cylindrical sleeve, two specific adjacent magnetic poles of the fixed magnet have the same polarity, A developing device characterized in that a toner concentration sensor is provided at a corresponding position between the magnetic poles having the same polarity.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP12680387A JPS63291072A (en) | 1987-05-22 | 1987-05-22 | Developing device |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP12680387A JPS63291072A (en) | 1987-05-22 | 1987-05-22 | Developing device |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPS63291072A true JPS63291072A (en) | 1988-11-28 |
Family
ID=14944348
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP12680387A Pending JPS63291072A (en) | 1987-05-22 | 1987-05-22 | Developing device |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS63291072A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH0468374A (en) * | 1990-07-09 | 1992-03-04 | Mita Ind Co Ltd | Manufacture of developing device and developing roller |
-
1987
- 1987-05-22 JP JP12680387A patent/JPS63291072A/en active Pending
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH0468374A (en) * | 1990-07-09 | 1992-03-04 | Mita Ind Co Ltd | Manufacture of developing device and developing roller |
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