JPH027471B2 - - Google Patents
Info
- Publication number
- JPH027471B2 JPH027471B2 JP56061447A JP6144781A JPH027471B2 JP H027471 B2 JPH027471 B2 JP H027471B2 JP 56061447 A JP56061447 A JP 56061447A JP 6144781 A JP6144781 A JP 6144781A JP H027471 B2 JPH027471 B2 JP H027471B2
- Authority
- JP
- Japan
- Prior art keywords
- carrier
- photoreceptor
- voltage
- magnetic brush
- brush sleeve
- 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.)
- Expired - Lifetime
Links
- 108091008695 photoreceptors Proteins 0.000 claims description 18
- 230000015556 catabolic process Effects 0.000 claims description 9
- 238000009413 insulation Methods 0.000 claims 1
- 238000010586 diagram Methods 0.000 description 4
- 230000005684 electric field Effects 0.000 description 4
- 239000000969 carrier Substances 0.000 description 3
- UQSXHKLRYXJYBZ-UHFFFAOYSA-N Iron oxide Chemical compound [Fe]=O UQSXHKLRYXJYBZ-UHFFFAOYSA-N 0.000 description 2
- 239000003990 capacitor Substances 0.000 description 1
- 230000008878 coupling Effects 0.000 description 1
- 238000010168 coupling process Methods 0.000 description 1
- 238000005859 coupling reaction Methods 0.000 description 1
- 238000000034 method Methods 0.000 description 1
- 239000000843 powder Substances 0.000 description 1
- 239000007787 solid Substances 0.000 description 1
Classifications
-
- G—PHYSICS
- G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
- G03G—ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY
- G03G15/00—Apparatus for electrographic processes using a charge pattern
- G03G15/06—Apparatus for electrographic processes using a charge pattern for developing
- G03G15/08—Apparatus for electrographic processes using a charge pattern for developing using a solid developer, e.g. powder developer
- G03G15/09—Apparatus for electrographic processes using a charge pattern for developing using a solid developer, e.g. powder developer using magnetic brush
- G03G15/0907—Apparatus for electrographic processes using a charge pattern for developing using a solid developer, e.g. powder developer using magnetic brush with bias voltage
Description
【発明の詳細な説明】
本発明は、トナーとキヤリアからなる２成分現
像法により感光体の静電潜像を現像するようにし
た電子複写機の現像装置に関するものである。DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a developing device for an electronic copying machine that develops an electrostatic latent image on a photoreceptor by a two-component developing method consisting of toner and carrier.
酸化鉄粉や、部分的にコートされたキヤリアを
用いた粉体の半導電性現像剤を用いた現像装置
は、ベタ黒部の再現性にすぐれているが、その一
方で磁気ブラシスリーブ自体が導電性を有してい
るため、感光体にキズがあつた場合には現像バイ
アス電圧が感光体よりリークしてしまうことと、
背景部にカブリが生じるという問題があつた。 Development devices using powdered semiconductive developers using iron oxide powder or partially coated carriers have excellent reproducibility of solid black areas, but on the other hand, the magnetic brush sleeve itself is conductive. If the photoreceptor is scratched, the developing bias voltage will leak from the photoreceptor.
There was a problem that fog appeared in the background.
これに対して従来は、磁気ブラシスリーブに半
導電性のスリーブを用いると共に、約１〜10μΩ
の高抵抗を現像バイアス用の電源とスリーブとの
間に入れ、また現像剤の導電性を下げる等の手段
により上記従来の問題点の改良が加えられてきた
が、未だ十分に問題は解決されていないのが現状
である。 On the other hand, in the past, a semiconductive sleeve was used as the magnetic brush sleeve, and the
Improvements have been made to the above conventional problems by placing a high resistance between the developing bias power source and the sleeve, and by lowering the conductivity of the developer, but the problems have not yet been fully resolved. The current situation is that this is not the case.
本発明は上記した従来技術の問題点を除去、改
良するためになされたもので、トナーとキヤリア
からなる２成分現像剤と、磁気ブラシスリーブを
用いて感光体の静電潜像を現像する現像装置にお
いて、上記キヤリアに、ブレークダウン電圧VB
を境に、低い電圧で絶縁性を示し、かつ、高い電
圧で導電性を示す半導電性キヤリアを用い、上記
磁気ブラシスリーブに、直流電圧にブレークダウ
ン電圧VBを境に上下する交番電圧を重畳して印
加するようにしたことにより、高抵抗なキヤリア
の見かけの抵抗を減少して、高抵抗なキヤリアを
用いて高濃度再現を可能にし、さらにバイアス電
流が感光体表面にリークするのを防止できるよう
にした現像装置を提供しようとするものである。 The present invention has been made to eliminate and improve the problems of the prior art described above, and is a developer that develops an electrostatic latent image on a photoreceptor using a two-component developer consisting of toner and carrier and a magnetic brush sleeve. In the device, the breakdown voltage V B is applied to the carrier.
Using a semiconductive carrier that exhibits insulating properties at low voltages and conductive properties at high voltages, an alternating voltage that rises and falls above and below breakdown voltage VB is applied to the magnetic brush sleeve. By superimposing the applied voltage, the apparent resistance of the high-resistance carrier is reduced, making it possible to reproduce high concentrations using the high-resistance carrier, and further preventing bias current from leaking to the photoreceptor surface. It is an object of the present invention to provide a developing device that can prevent such problems.
本発明の原理は、キヤリアのブレークダウン現
象と、半導電性キヤリアの非線型電圧―電流特性
を利用するものである。 The principle of the present invention utilizes the carrier breakdown phenomenon and the nonlinear voltage-current characteristics of semiconducting carriers.
ブレークダウン電圧VBを有する半導性キヤリ
アの電圧―電流特性は、第１図に示すように非線
形である。磁気ブラシスリーブにバイアス電圧を
印加すると、そのバイアス電圧がブレークダウン
電圧VBより小さい場合、キヤリアは絶縁性を示
し、電荷の注入は殆ど行なわれない。ところが、
そのバイアス電圧がブレークダウン電圧VBより
大きい場合、キヤリアは導電性を示し、磁気ブラ
シスリーブよりキヤリアへ電荷が注入される。こ
の注入された電荷は、感光体まで到達してバイア
スリークの原因となる。ところが、注入されたキ
ヤリアの電荷が感光体に電界を反転してやると、
キヤリアの電荷は磁気ブラシスリーブへ向かつて
逆方法に移動する。この電界を順次正・負反転、
つまり直流電圧にブレークダウン電圧VBを境に
上下する交番電圧を重畳した交番電界にすること
により、電荷が感光体に到達することなく、キヤ
リアへの電荷注入を行なうことができる。従つ
て、導電性キヤリアと同じようにキヤリアへの電
荷注入を行ない、感光体と磁気ブラシスリーブと
の電気的な間隔を見かけ上小さくすることにより
現像電場を大きくし、高濃度再現を可能としてい
る。しかも、注入されたキヤリアの電荷が感光体
表面に到達しないので、バイアス電流が感光体表
面にリークしなくなる。 The voltage-current characteristic of a semiconducting carrier with a breakdown voltage V B is nonlinear, as shown in FIG. When a bias voltage is applied to the magnetic brush sleeve, if the bias voltage is lower than the breakdown voltage V B , the carrier exhibits insulating properties and almost no charge is injected. However,
If the bias voltage is greater than the breakdown voltage V B , the carrier becomes conductive and charge is injected into the carrier from the magnetic brush sleeve. This injected charge reaches the photoreceptor and causes bias leakage. However, when the injected carrier charge reverses the electric field on the photoreceptor,
The carrier charge moves in the opposite direction towards the magnetic brush sleeve. This electric field is sequentially reversed between positive and negative.
In other words, by creating an alternating electric field in which an alternating voltage that rises and falls above and below the breakdown voltage V B is superimposed on a DC voltage, charge can be injected into the carrier without the charge reaching the photoreceptor. Therefore, charge is injected into the carrier in the same way as with conductive carriers, and by reducing the apparent electrical distance between the photoreceptor and the magnetic brush sleeve, the developing electric field is increased, making it possible to reproduce high density. . Moreover, since the injected carrier charges do not reach the surface of the photoreceptor, bias current does not leak to the surface of the photoreceptor.
次に第２図以下に示した実施例を参照して説明
する。 Next, a description will be given with reference to the embodiment shown in FIG. 2 and subsequent figures.
図中１は感光体、２は磁気ブラシスリーブであ
り、この磁気ブラシスリーブ２にカツプリングコ
ンデンサ３を介して交番電源４と、現像バイアス
用の直流電源５とが重畳接続してある。６はトナ
ー容器、７は絶縁性トナー、８は半導電性のキヤ
リアである。交番電源４のパルス波形は第３図に
示すようになり、パルス幅は0.1msec、パルス間
幅は0.3msecとした。パルス幅は0.1msecより大
きくなるとキヤリアから電荷が感光体１へ転移
し、背景部の汚れとなつた。なお、キヤリア８の
導電性が低い場合にはパルス幅は0.1msecより大
きくてもよい。またパルスのピーク電圧は現像濃
度と高い相関があり、第４図に示すように、現像
濃度は交番電圧を印加しない場合ａに比べて交番
電圧を印加した場合ｂの方が感光体電位が1000V
で1.5倍の濃度となつた。 In the figure, 1 is a photoreceptor, 2 is a magnetic brush sleeve, and an alternating current power source 4 and a DC power source 5 for developing bias are superimposedly connected to the magnetic brush sleeve 2 via a coupling capacitor 3. 6 is a toner container, 7 is an insulating toner, and 8 is a semiconductive carrier. The pulse waveform of the alternating current power source 4 was as shown in FIG. 3, with a pulse width of 0.1 msec and an interpulse width of 0.3 msec. When the pulse width was larger than 0.1 msec, the charge was transferred from the carrier to the photoreceptor 1 and became a stain in the background area. Note that if the carrier 8 has low conductivity, the pulse width may be greater than 0.1 msec. In addition, the peak voltage of the pulse has a high correlation with the developed density, and as shown in Figure 4, the developed density is higher when the photoreceptor potential is 1000 V when an alternating voltage is applied than when an alternating voltage is applied (a).
The concentration was 1.5 times higher.
本発明は以上のようになるから、高抵抗なキヤ
リアの見かけの抵抗を減少して、高抵抗なキヤリ
アを用いて高濃度再現を可能にすることができ、
さらにバイアス電流が感光体１の表面にリークす
るのを防止できる。 Since the present invention is as described above, it is possible to reduce the apparent resistance of a high-resistance carrier and to enable high-density reproduction using a high-resistance carrier.
Furthermore, bias current can be prevented from leaking to the surface of the photoreceptor 1.
第１図はキヤリアの電圧―電流特性を示す線
図、第２図は本発明の実施例を示す構成説明図、
第３図は交番電圧のパルスを示す線図、第４図は
感光体電位と現像濃度の関係を示す線図である。
１は感光体、２は磁気ブラシスリーブ、４は交
番電源、５は直流電源、８はキヤリア。
Fig. 1 is a diagram showing the voltage-current characteristics of the carrier, Fig. 2 is a configuration explanatory diagram showing an embodiment of the present invention,
FIG. 3 is a diagram showing alternating voltage pulses, and FIG. 4 is a diagram showing the relationship between photoreceptor potential and developer density. 1 is a photoreceptor, 2 is a magnetic brush sleeve, 4 is an alternating current power supply, 5 is a DC power supply, and 8 is a carrier.
Claims (1)
磁気ブラシスリーブ２を用いて感光体の静電潜像
を現像する現像装置において、上記キヤリアに、
ブレークダウン電圧VBを境に、低い電圧で絶縁
性を示し、かつ、高い電圧で導電性を示す半導電
性キヤリア８を用い、上記磁気ブラシスリーブ２
に、直流電圧にブレークダウン電圧VBを境に上
下する交番電圧を重畳して印加するようにしたこ
とを特徴とする現像装置。1. A two-component developer consisting of toner and carrier;
In a developing device that develops an electrostatic latent image on a photoreceptor using a magnetic brush sleeve 2, the carrier includes:
Using a semiconductive carrier 8 that exhibits insulation at low voltages and conductivity at high voltages with the breakdown voltage V B as the boundary, the magnetic brush sleeve 2 is
A developing device characterized in that an alternating voltage that rises and falls above and below a breakdown voltage VB is applied superimposed on the direct current voltage.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP56061447A JPS57177171A (en) | 1981-04-24 | 1981-04-24 | Developing device of electrophotographic copying machine |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP56061447A JPS57177171A (en) | 1981-04-24 | 1981-04-24 | Developing device of electrophotographic copying machine |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS57177171A JPS57177171A (en) | 1982-10-30 |
| JPH027471B2 true JPH027471B2 (en) | 1990-02-19 |
Family
ID=13171319
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP56061447A Granted JPS57177171A (en) | 1981-04-24 | 1981-04-24 | Developing device of electrophotographic copying machine |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS57177171A (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4496644A (en) * | 1983-02-28 | 1985-01-29 | Eastman Kodak Company | Electric field adjustment for magnetic brushes |
Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5543562A (en) * | 1978-09-22 | 1980-03-27 | Ricoh Co Ltd | Developing method |
| JPS5555373A (en) * | 1978-10-20 | 1980-04-23 | Ricoh Co Ltd | Pulse bias developing system for magnetic toner |
-
1981
- 1981-04-24 JP JP56061447A patent/JPS57177171A/en active Granted
Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5543562A (en) * | 1978-09-22 | 1980-03-27 | Ricoh Co Ltd | Developing method |
| JPS5555373A (en) * | 1978-10-20 | 1980-04-23 | Ricoh Co Ltd | Pulse bias developing system for magnetic toner |
Also Published As
| Publication number | Publication date |
|---|---|
| JPS57177171A (en) | 1982-10-30 |
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