JPH038542B2 - - Google Patents
Info
- Publication number
- JPH038542B2 JPH038542B2 JP16661581A JP16661581A JPH038542B2 JP H038542 B2 JPH038542 B2 JP H038542B2 JP 16661581 A JP16661581 A JP 16661581A JP 16661581 A JP16661581 A JP 16661581A JP H038542 B2 JPH038542 B2 JP H038542B2
- Authority
- JP
- Japan
- Prior art keywords
- toner
- developer
- carrier
- image
- developing
- 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
Links
- 238000000034 method Methods 0.000 claims description 25
- 238000011161 development Methods 0.000 claims description 21
- 230000005684 electric field Effects 0.000 claims description 20
- 239000000843 powder Substances 0.000 claims description 9
- 239000006247 magnetic powder Substances 0.000 claims description 5
- 238000002156 mixing Methods 0.000 claims description 5
- 230000001105 regulatory effect Effects 0.000 claims description 3
- 238000012546 transfer Methods 0.000 description 31
- 239000002245 particle Substances 0.000 description 25
- 239000000696 magnetic material Substances 0.000 description 6
- 230000007704 transition Effects 0.000 description 5
- 230000006866 deterioration Effects 0.000 description 3
- 238000002474 experimental method Methods 0.000 description 3
- UQSXHKLRYXJYBZ-UHFFFAOYSA-N Iron oxide Chemical compound [Fe]=O UQSXHKLRYXJYBZ-UHFFFAOYSA-N 0.000 description 2
- 239000004020 conductor Substances 0.000 description 2
- 238000010586 diagram Methods 0.000 description 2
- 239000012212 insulator Substances 0.000 description 2
- SZVJSHCCFOBDDC-UHFFFAOYSA-N iron(II,III) oxide Inorganic materials O=[Fe]O[Fe]O[Fe]=O SZVJSHCCFOBDDC-UHFFFAOYSA-N 0.000 description 2
- 238000002844 melting Methods 0.000 description 2
- 230000008018 melting Effects 0.000 description 2
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 1
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 description 1
- 239000001000 anthraquinone dye Substances 0.000 description 1
- 229910052799 carbon Inorganic materials 0.000 description 1
- 239000006229 carbon black Substances 0.000 description 1
- 239000011248 coating agent Substances 0.000 description 1
- 238000000576 coating method Methods 0.000 description 1
- 239000003086 colorant Substances 0.000 description 1
- 238000001816 cooling Methods 0.000 description 1
- 239000003822 epoxy resin Substances 0.000 description 1
- 230000009191 jumping Effects 0.000 description 1
- 230000005389 magnetism Effects 0.000 description 1
- 238000000691 measurement method Methods 0.000 description 1
- 239000000203 mixture Substances 0.000 description 1
- 108091008695 photoreceptors Proteins 0.000 description 1
- 239000000049 pigment Substances 0.000 description 1
- 229920000647 polyepoxide Polymers 0.000 description 1
- 229920001225 polyester resin Polymers 0.000 description 1
- 239000004645 polyester resin Substances 0.000 description 1
- 238000003825 pressing Methods 0.000 description 1
- 238000010298 pulverizing process Methods 0.000 description 1
- 229920005989 resin Polymers 0.000 description 1
- 239000011347 resin Substances 0.000 description 1
- PYWVYCXTNDRMGF-UHFFFAOYSA-N rhodamine B Chemical compound [Cl-].C=12C=CC(=[N+](CC)CC)C=C2OC2=CC(N(CC)CC)=CC=C2C=1C1=CC=CC=C1C(O)=O PYWVYCXTNDRMGF-UHFFFAOYSA-N 0.000 description 1
- 229920006395 saturated elastomer Polymers 0.000 description 1
- 238000007790 scraping Methods 0.000 description 1
- 125000006850 spacer group Chemical group 0.000 description 1
- 230000003068 static effect Effects 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
Landscapes
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Magnetic Brush Developing In Electrophotography (AREA)
- Developing For Electrophotography (AREA)
Description
【発明の詳細な説明】
本発明は、静電潜像を現像する現像方法に関す
るものである。DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a developing method for developing an electrostatic latent image.
本出願人は先に特開昭55−18656号〜18659号公
報において新規な現像方法を開示した。これは、
内部に磁石を有する円筒状の現像剤支持部材上に
絶縁性磁性トナーを均一に塗布し、これを潜像保
持部材に接触させる事なく対向せしめ、現像する
ものである。この時、現像剤支持部材と、潜像保
持部材の基盤導体との間に低周波交番電圧を印加
し、トナーを現像剤支持部材と潜像保持部材の間
で往復運動させることにより地カブリのないかつ
階調性の再現にすぐれ、画像端部の細りのない良
好な現像を行う事ができる。この現像方法ではト
ナーは絶縁体であるため転写が容易である。又、
現像装置がきわめて簡単で、安価であるというも
のである。 The present applicant previously disclosed a novel developing method in Japanese Patent Application Laid-Open Nos. 18656-18659. this is,
Insulating magnetic toner is uniformly applied onto a cylindrical developer support member having a magnet inside, and the toner is placed facing the latent image holding member without coming into contact with it for development. At this time, a low frequency alternating voltage is applied between the developer support member and the base conductor of the latent image holding member to cause the toner to reciprocate between the developer support member and the latent image holding member, thereby eliminating background fog. It has excellent gradation reproduction and can perform good development without thinning at the edges of the image. In this developing method, since the toner is an insulator, transfer is easy. or,
The developing device is extremely simple and inexpensive.
しかしながら、この現像方法においては、磁性
を有するトナーを用いなければならないことから
次のような欠点を有していた。磁性トナーは一般
に黒色の磁性体粉をふくむため黒色以外の色のト
ナーを作る事は困難である。又磁性体粉をふくむ
事によりトナー像を、熱定着器、圧力定着器等に
より定着する時定着性が劣り、画像が荒びる。 However, this developing method has the following drawbacks because it requires the use of magnetic toner. Since magnetic toner generally contains black magnetic powder, it is difficult to produce toner of colors other than black. Furthermore, by containing magnetic powder, when a toner image is fixed using a heat fixing device, a pressure fixing device, etc., the fixing performance is poor and the image becomes rough.
磁性を有しないトナーを現像剤支持部材に塗付
し、これを静電像保持部材に対向させて現像する
方法は古くから知られている。しかし、これは現
像剤支持部材にトナーを均一に塗布する事が困難
である事、静電像がきわめて高い電位を有しなけ
れば現像が困難である事、現像像の画像の画質が
劣る事等々の欠点のため、実用に供されるに至つ
ていない。 2. Description of the Related Art A method has long been known in which a non-magnetic toner is applied to a developer supporting member, and the toner is developed by facing an electrostatic image holding member. However, this is because it is difficult to uniformly apply toner to the developer support member, it is difficult to develop the electrostatic image unless it has an extremely high potential, and the image quality of the developed image is poor. Due to these drawbacks, it has not been put to practical use.
一成分現像方式のこの様な欠点のため、従来、
殊にカラートナーを用いて現像する場合等には、
トナーとキヤリアを混合した２成分現像剤を用い
る方法が一般的である。ところが、２成分現像方
式はキヤリアの劣化が有る事、トナーとキヤリア
を一定の比率に保たなければならず、その制御が
困難である事、現像器が大型かつ複雑である事等
の欠点を有している。 Due to these drawbacks of the one-component development method, conventional
Especially when developing using color toner,
A common method is to use a two-component developer containing a mixture of toner and carrier. However, the two-component development method has drawbacks such as deterioration of the carrier, the need to maintain a constant ratio of toner and carrier, which is difficult to control, and a large and complicated developing device. have.
本発明は、従来の現像方法の前述のごとき欠点
を解消することを目的とするもので、現像器とし
ては、前述の特開昭54−18656号〜18659号公報等
で開示された現像方法に用いられる現像器と同じ
ものか、又はほぼ同じ構成のものを用いる事がで
きる。現像剤は少量のキヤリアを含むが、これは
ほとんど消費される事もなく劣化もない。又、ト
ナーとキヤリアの混合比の許容範囲は広い。 The purpose of the present invention is to eliminate the above-mentioned drawbacks of conventional developing methods. It is possible to use the same developing device as that used, or one having almost the same configuration. The developer contains a small amount of carrier, but this is hardly consumed and does not deteriorate. Also, there is a wide permissible range for the mixing ratio of toner and carrier.
本発明は、いずれか一方を大として大きさの比
が１：３以内である絶縁性トナーと導電性及び磁
性を有する粉体を重量比で１：４乃至１：１で混
合した現像剤を現像剤担持体に供給し、この現像
剤を現像剤担持体上に現像剤規制手段によつて現
像位置における現像剤担持体と像担持体との間隔
よりも薄く層状に塗布し、この現像剤層を現像剤
担持体内に配置された磁石の磁極が像保持体に対
向している現像位置へ運び、現像位置において上
記現像剤担持体と像保持体との間〓に交番電界を
形成して絶縁縁性トナーを像保持体に付着、離脱
させるとともに、導電性磁性粉体を像保持体に付
着、離脱させて現像を行なうことを特徴とする現
像方法である。 The present invention uses a developer in which an insulating toner and a powder having conductivity and magnetism are mixed in a weight ratio of 1:4 to 1:1, the size ratio of which is within 1:3. The developer is supplied to the developer carrier, and the developer is applied onto the developer carrier by a developer regulating means in a layer thinner than the distance between the developer carrier and the image carrier at the development position. The layer is transported to a development position where the magnetic poles of a magnet disposed within the developer carrier face the image carrier, and an alternating electric field is formed between the developer carrier and the image carrier at the development position. This developing method is characterized in that insulating edge toner is attached to and detached from the image carrier, and conductive magnetic powder is attached to and detached from the image carrier to perform development.
導電性及び磁性を有する粉体としては、酸化鉄
粉等が使用可能であるが、磁性体と樹脂を溶融混
合し粉砕し、カーボン等で導電処理した公知の導
電性磁性トナーと同様のものが、より好適であ
る。 As the conductive and magnetic powder, iron oxide powder etc. can be used, but it is also possible to use a powder similar to the known conductive magnetic toner, which is made by melting and mixing a magnetic material and resin, pulverizing it, and treating it with conductive material such as carbon. , is more suitable.
現像剤支持部材に現像剤を塗布する方法として
は、例えば特開昭54−43037号公報記載のごとく、
現像剤支持部材に内装された磁界発生手段の磁極
に対向して磁性体のブレードを配置し、磁気カツ
トによりブレードと支持部材との間隙よりも薄い
トナー層を形成することが可能である。磁性を有
しないトナーは一般に現像剤支持部材に均一に塗
付する事が困難であるが、本発明の方法ではトナ
ーは磁性を有するキヤリアと混合されているた
め、キヤリアとともに薄く均一に塗布される。 As a method of applying the developer to the developer support member, for example, as described in Japanese Patent Application Laid-Open No. 54-43037,
It is possible to arrange a blade of a magnetic material opposite to the magnetic pole of a magnetic field generating means built into the developer support member, and form a toner layer thinner than the gap between the blade and the support member by magnetic cutting. Generally, it is difficult to apply non-magnetic toner uniformly to a developer support member, but in the method of the present invention, since the toner is mixed with a magnetic carrier, it can be applied thinly and uniformly together with the carrier. .
塗布された現像剤層はきわめて薄く、トナーが
現像剤支持部材、ブレード等と直接接する機会が
多い。そのためキヤリア粉の摩擦帯電特性等はあ
まり重要でなく、トナー自体がすぐれた摩擦帯電
特性を有していれば良好な画像が得られる。従つ
て通常の２成分現像方式に見られるようなキヤリ
アの劣化にともなう画質の低下はほとんど無い。 The applied developer layer is extremely thin, and there are many opportunities for the toner to come into direct contact with the developer support member, blade, etc. Therefore, the triboelectric charging properties of the carrier powder are not very important, and good images can be obtained as long as the toner itself has excellent triboelectric charging properties. Therefore, there is almost no deterioration in image quality due to deterioration of the carrier as seen in ordinary two-component development systems.
現像剤は、トナーととキヤリアが混合されたま
まの状態で現像剤支持部材に内装された磁石によ
り支持された潜像保持部材に対向される。ここで
潜像の静電気力及び現像剤支持部材と潜像保持部
材の間に印加された低周波交番電圧により現像剤
が潜像保持部材へと飛び移り、交番電圧に応じて
往復運動する。 The developer is opposed to a latent image holding member supported by a magnet installed in the developer support member while the toner and carrier are still mixed. Here, the developer jumps to the latent image holding member due to the electrostatic force of the latent image and the low frequency alternating voltage applied between the developer supporting member and the latent image holding member, and moves back and forth in response to the alternating voltage.
以下第１図及び第２図を例にとつてこの現像剤
の往復運動の原理について説明する。図におい
て、下段にはトナー担持体に印加する電圧波形が
示され、ここでは矩形波となつているが、後述す
るようにこれに限るものではない。時間間隔t1で
大きさVminの負の極性のバイアス電圧が印加さ
れ、また時間間隔t2では大きさVmaxの正の極性
のバイアス電圧が印加される。Vmin、Vmaxの
大きさは、像面に形成されている画像部電荷が正
で、これを負に帯電したトナーで現像する場合は
画像部電位をVD、非画像部電位をVLとするとき、
Vmin＜VL＜VD＜Vmax………(1)
を満足するように選ぶ。このように選べば、時間
間隔t1ではバイアス電圧Vminは静電潜像保持体
の画像部及び非画像部へのトナーの付着を促進す
る傾向にバイアス電界を与えるように作用するの
でトナー転移段階と呼ぶ。また時間間隔t2ではバ
イアス電圧Vmaxは時間間隔t1において潜像保持
面へ転移したトナーを逆にトナー担持体へ戻す傾
向にバイアス電界を与えるように作用するのでト
ナー逆転移段階と呼ぶ。 The principle of this reciprocating movement of the developer will be explained below using FIGS. 1 and 2 as examples. In the figure, the voltage waveform applied to the toner carrier is shown in the lower part, and although it is a rectangular wave here, it is not limited to this as will be described later. During time interval t 1 a negative polarity bias voltage of magnitude Vmin is applied, and during time interval t 2 a positive polarity bias voltage of magnitude Vmax is applied. The magnitude of Vmin and Vmax is determined by assuming that the image area charge formed on the image surface is positive and that this is to be developed with negatively charged toner, the image area potential is V D and the non-image area potential is V L. When, Vmin < V L < V D < Vmax (1) is selected. If chosen in this way, during the time interval t 1 the bias voltage Vmin acts to provide a bias electric field that tends to promote the adhesion of toner to the image and non-image areas of the electrostatic latent image carrier, so that the toner transfer stage It is called. In the time interval t 2 , the bias voltage Vmax acts to provide a bias electric field that tends to return the toner transferred to the latent image holding surface in the time interval t 1 to the toner carrier, which is called a toner reverse transfer stage.
第１図に於けるVth・ｆ，Vth・ｒは、それぞ
れトナー担持体から潜像面へまた潜像面からトナ
ー担持体へトナーが転移するための電位閾値であ
り、図に示された曲線の立ち上がりの最も傾きの
大きい点より、直線で外挿した電位値と考える。
第１図上段には、t1におけるトナー転移量とt2に
おけるトナー逆転移度が潜像電位に対してモデル
的にプロツトされている。 Vth・f and Vth・r in FIG. 1 are potential thresholds for toner transfer from the toner carrier to the latent image surface and from the latent image surface to the toner carrier, respectively, and the curves shown in the figure It is considered that the potential value is extrapolated by a straight line from the point where the slope of the rise is the largest.
In the upper part of FIG. 1, the amount of toner transfer at t 1 and the degree of toner reverse transfer at t 2 are plotted as a model against the latent image potential.
トナー転移段階における、トナー担持体から静
電像保持体へのトナー転移量は、第１図に破線で
示したカーブ１の如くになる。この曲線の傾き
は、バイアス交互電圧を印加しない場合の曲線の
傾きにほぼ等しいものである。この傾きは大き
く、しかもVLとVDとの中間の値で、トナー転移
量は飽和してしまう傾向にあり、従つて中間調画
像の再現に劣り、階調性は悪い。第１図に示した
第２の破線のカーブ２は、トナー逆転度の確率を
表わしたものである。 In the toner transfer stage, the amount of toner transferred from the toner carrier to the electrostatic image holder is as shown by curve 1 shown by a broken line in FIG. The slope of this curve is approximately equal to the slope of the curve when no alternating bias voltage is applied. This slope is large, and the amount of toner transfer tends to be saturated at an intermediate value between V L and V D , resulting in poor halftone image reproduction and poor gradation. The second broken line curve 2 shown in FIG. 1 represents the probability of the degree of toner reversal.
本発明に係る現像方法においては、このような
トナー転移段階と、トナー逆転移段階とが、交互
に繰り返されるように交番する電界を与えその交
番電界のトナー転移段階のバイアス位相t1では、
トナー支持体からトナーを静電潜像保持体の非画
像部にまでもあえて一旦到達させ（勿論画像部に
も到達させる）、明部電位（VL）に近い低い電位
をもつ中間調の電位部分にも充分にトナーを付着
させて階調性を向上させるようにし、次いで、ト
ナー逆転移段階のバイアス位相t2では、上記トナ
ー転移方向と逆方向にバイアスを作用させて、上
述のように非画像部にも到達しているトナーをも
とのトナー支持体側へ復帰させるものである。こ
のトナー逆転移段階では、後述するように、非画
像部に本来像電位を実質的に有しないから、逆極
性のバイアス電界が印加されると上述のように非
画像部に到達しているトナーは直ちに該非画像部
から離れてトナー担持体へ復帰する傾向をもつ。
他方中間調域を含む画像部に一旦付着したトナー
は該画像部電荷に吸引されているから、この吸引
力と逆方向に上述の如く逆バイアスが印加されて
も、実際に該画像部を離れてトナー支持体側へ復
帰する量は少い。このように相互に極性の異なる
バイアス電界を好ましい振幅と周波数で交番させ
ることにより、上記のトナーの転移と逆転移が多
数回、現像位置で繰返される。こうして潜像面に
転移するトナー転移量を静電像の電位に忠実な転
移量とできる。即ちトナー転移通を第１図にカー
ブ３として示した通り、傾きの小さい、且つVL
からVDにかけてほぼ一様なトナー転移量変化を
来たす現象を得ることが出来たものである。従つ
て、非画像部においては、最終的にトナーの付着
は実用上皆無に近く、他方中間調画像部分へのト
ナーの付着は、その表面電位に則した階調性の極
めて高い優れた顕画像が得られる。そして、この
傾向は、静電潜像保持体とトナー担持体の間隙が
現像過程の終期に向つて大となるよう設定して、
現像間隙における上述の電界の強度を減じ、収束
させることによつて一層顕著にある。 In the developing method according to the present invention, an alternating electric field is applied so that the toner transfer stage and the toner reverse transfer stage are alternately repeated, and in the bias phase t 1 of the toner transfer stage of the alternating electric field,
The toner from the toner support is intentionally made to reach the non-image area of the electrostatic latent image holding member (of course, it also reaches the image area), and the potential of the midtone has a low potential close to the bright area potential (V L ). The toner is sufficiently attached to the area to improve the gradation, and then, in the bias phase t 2 of the toner reverse transfer stage, a bias is applied in the opposite direction to the toner transfer direction as described above. The toner that has reached the non-image area is returned to the original toner support side. In this toner reverse transfer stage, as will be described later, since the non-image area originally has no image potential, when a bias electric field of opposite polarity is applied, the toner reaches the non-image area as described above. tends to immediately leave the non-image area and return to the toner carrier.
On the other hand, since the toner once attached to the image area including the halftone area is attracted by the charge of the image area, even if a reverse bias is applied in the opposite direction to this attraction force as described above, the toner will not actually leave the image area. The amount that returns to the toner support is small. By alternating the bias electric fields having mutually different polarities at a preferable amplitude and frequency, the above-mentioned toner transfer and reverse transfer are repeated many times at the development position. In this way, the amount of toner transferred to the latent image surface can be made faithful to the potential of the electrostatic image. That is, as shown in Figure 1 as curve 3, the toner transfer flow has a small slope and V L
We were able to obtain a phenomenon in which the amount of toner transfer changes almost uniformly from VD to VD . Therefore, in the non-image area, there is almost no toner adhesion in practical terms, while toner adhesion to the halftone image area results in an excellent visible image with extremely high gradation in accordance with the surface potential. is obtained. This tendency can be overcome by setting the gap between the electrostatic latent image holding member and the toner carrying member to become larger towards the end of the developing process.
This is even more pronounced by reducing and converging the strength of the above-mentioned electric field in the development gap.
本発明に係るこのような現像過程の一例を第２
図に示す。第２図Ａ，Ｂに示されるように、静電
像保持体４は矢印方向に移動し、この間に現像領
域、を通過し、に至る。５はトナー担持体
である。従つて静電像保持面と、トナー担持体は
現像部において最近接位置から、次第にその間隙
を広げていく。同図Ａは静電像保持体の画像部、
同Ｂは非画像部におけるトナー担持体からの転
移、逆転移の電界を示す。又、同図Ｃは、トナー
担持体に印加される交互電圧の波形を示し、静電
像電荷が正の場合、
｜Vmax−VL｜＞｜VL−Vmin｜、
｜Vmax−VD｜＜｜VD−Vmin｜ ……(2)
と設定されている。 An example of such a developing process according to the present invention is shown in the second example.
As shown in the figure. As shown in FIGS. 2A and 2B, the electrostatic image holder 4 moves in the direction of the arrow, during which it passes through a development area and reaches . 5 is a toner carrier. Therefore, the gap between the electrostatic image holding surface and the toner carrier gradually widens starting from the closest position in the developing section. A in the same figure shows the image area of the electrostatic image holder;
B shows the electric field of the transfer and countertransference from the toner carrier in the non-image area. Further, C in the same figure shows the waveform of the alternating voltage applied to the toner carrier, and when the electrostatic image charge is positive, |Vmax−V L |>|V L −Vmin|, |Vmax−V D | <|V D −Vmin| ...(2) is set.
領域で現像における第１の過程が、又領域
で第２の過程が生じている。第２図Ａに示した画
像部の場合、領域では、交互電界の位相に応じ
てトナーの転移、逆転移の両方が交互におこつて
いる。現像間隙が大となつていくためでは、共
に転移、逆転移電界が弱くなり、トナー転移は可
能であるが逆転移をおこす程（閾値以下）の逆転
移電界はなくなる。では、最早転移、逆転移共
におこらず、現像は完結する。 A first process in development is occurring in the area, and a second process is occurring in the area. In the case of the image area shown in FIG. 2A, both toner transfer and countertransference occur alternately in the area depending on the phase of the alternating electric field. As the development gap becomes larger, both the transition and reverse transition electric fields become weaker, and although toner transfer is possible, the reverse transition electric field is no longer strong enough to cause reverse transition (below the threshold). Now, neither transfer nor countertransference occurs, and development is completed.
第２図Ｂに示した非画像部の場合、領域では
トナーの転移、逆転移の両方がおこつている。従
つてこの領域では地カブリが生じている。では
共に転移、逆転移電界が弱くなり、トナー逆転移
は可能であるが転移をおこす程の（閾値以下）の
転移電界は無くなる。したがつてこの領域で地カ
ブリは実質的に起こらず、生じていた地カブリも
除去される。では最早転移、逆転移共におこら
ず、現像は完結する。中間調の画像部について
は、その電位に応じたトナー転移量と逆転移量の
大小によつて最終的な潜像面へのトナー転移量が
決まり、結局第１図の曲線３のように傾きの小さ
い。従つて階調性の高い顕画像が得られる。 In the case of the non-image area shown in FIG. 2B, both toner transfer and reverse transfer occur in the area. Therefore, ground fog occurs in this area. In this case, both the transfer and counter-transition electric fields become weak, and although toner counter-transition is possible, the transfer electric field (below the threshold value) sufficient to cause the transition disappears. Therefore, ground fog does not substantially occur in this area, and any ground fog that has occurred is also removed. In this case, neither transfer nor countertransference occurs anymore, and development is completed. For halftone image areas, the final amount of toner transferred to the latent image surface is determined by the magnitude of the toner transfer amount and the reverse transfer amount according to the potential, and the slope is as shown in curve 3 in Figure 1. Small. Therefore, a microscopic image with high gradation can be obtained.
このように、現像間隙を飛行させて非画像部に
も一旦トナーを到達させて階調性を改善させ次い
で該非画像部から主として付着トナーをはぎとる
ように作用させるためには、印加する交互バイア
ス電圧の振幅と交番の周波数とを適正に選定する
必要がある。 In this way, in order to cause the toner to fly through the development gap and once reach the non-image area to improve the gradation, and then to mainly strip off the adhered toner from the non-image area, the alternating bias voltage to be applied is necessary. It is necessary to appropriately select the amplitude of the signal and the frequency of the alternation.
このようにしてトナー担持体と静電像保持体と
の間で現像剤の往復運動が行なわれるわけである
が、この過程の詳細は未だ十分には解明されてい
ない。本発明では現像剤中のキヤリアと、トナー
はともに飛び移り往復運動をしているものと推定
される。しかしなから、この過程でトナーとキヤ
リアが分離され、トナーのみが潜像保持部材上に
残る。これはキヤリア粒子が導電性であるためで
あると推定される。絶縁体で、かつ電荷を有する
トナーは静電像の画像部に付着すると容易に離れ
ない。ところが、導電性の粒子は、現像剤支持部
材から潜像保持部材に飛び移る過程では、現像剤
支持部材から電荷が注入するが、静電像の画像部
に接した時、静電像の電荷により容易に中和され
場合によつては極性が反転して、現像剤支持部材
への飛び移つてしまう。このように、導電性粒子
は強い付着力を示さないため、最終的には磁力に
より現像剤支持部材に保持される。従つて、静電
像保持部材上には最終的には絶縁性トナーのみに
よつて可視像が形成される。 In this way, the developer is reciprocated between the toner carrier and the electrostatic image holder, but the details of this process have not yet been fully elucidated. In the present invention, it is presumed that both the carrier and the toner in the developer jump and move back and forth. However, during this process, the toner and carrier are separated, and only the toner remains on the latent image holding member. This is presumed to be because the carrier particles are electrically conductive. Toner, which is an insulator and has a charge, does not easily separate when it adheres to the image area of an electrostatic image. However, during the process of conductive particles jumping from the developer support member to the latent image holding member, charge is injected from the developer support member, but when they come into contact with the image area of the electrostatic image, the charge of the electrostatic image is injected into the conductive particles. The developer is easily neutralized by the developer, and in some cases, the polarity is reversed, causing the developer to jump to the developer support member. As described above, since the conductive particles do not exhibit strong adhesion, they are ultimately held on the developer support member by magnetic force. Therefore, a visible image is ultimately formed on the electrostatic image holding member only by the insulating toner.
本発明の現像方法においては、キヤリア粒子は
主としてトナーを現像剤支持部材上に薄く塗布
し、これを磁力により支持し、磁力によりほぐす
ために必要なのであつて、静電的特性はあまり重
要ではない。それ故トナーとキヤリアの混合比は
比較的自由である。さらに、現像剤支持部材上に
所定量のキヤリア粒子が有ればキヤリア粒子は、
現像剤支持部材から離れないのでトナーのみを補
給すれば良い。 In the developing method of the present invention, the carrier particles are mainly necessary for thinly coating the toner on the developer support member, supporting it with magnetic force, and loosening it with magnetic force, and the electrostatic properties are not so important. . Therefore, the mixing ratio of toner and carrier is relatively free. Furthermore, if there is a predetermined amount of carrier particles on the developer support member, the carrier particles will be
Since the toner does not separate from the developer support member, only toner needs to be replenished.
第３図に示した現像装置を用いて実験を行なつ
た。図の装置で、４は公知の電子写真法によつて
得られた静電潜像を有する静電像保持体である。
５は内部に固定マグネツト・ロール６を有する非
磁性の現像剤担持体としての現像スリーブであ
る。現像部は静電像保持部４に対向して現像スリ
ーブ５の内部に磁極（例えば図示のＳ極、約650
ガウス）を配置し、現像スリーブ５と静電像保持
体４との間隔はスリーブ両端に配したスペーサー
コロによつて300μmに保持されている。又は磁性
体からなるブレードであり、ホツパー８の中の本
発明現像剤９を目的の厚みに規制する。トナーは
主に現像スリーブ５との間で摩擦帯電される。こ
の磁性体又は磁石からなるブレード７に対向し
て、現像スリーブ５の内側にマグネツト・ロール
６の一つの磁極（例えば図示例ではN1極850ガウ
ス）を配置させている。この場合現像スリーブ５
とこの磁性体からなるブレード７との間隔を
250μmに設定し、磁性体からなるブレード７と現
像スリーブ５との間に磁界によつて現像スリーブ
５の本発明の現像剤９の層の厚みを規制してい
る。現像スリーブ５の回転方向は図のように感光
体の回転方向と同じである。図中１０はスクレー
パーブレードでスリーブ５上の残留現像剤を掻き
落とすためのものであり、１１はスリーブ５感光
ドラム４との間に交番電界を形成するための電源
であり、パルス波、交流、交流に直流を重畳した
電圧等を発生する。この実施例では1000VP-Pの
交流に＋200Vの直流バイアスを重畳させた電源
を用いた。因みに感光ドラム４上の潜像電位は画
像部で＋500V、非画像部でOVであつた。
Experiments were conducted using the developing device shown in FIG. In the apparatus shown in the figure, 4 is an electrostatic image carrier having an electrostatic latent image obtained by a known electrophotographic method.
Reference numeral 5 designates a developing sleeve as a non-magnetic developer carrier having a fixed magnet roll 6 therein. The developing section has a magnetic pole (for example, the S pole shown in the figure, approximately 650 mm) inside the developing sleeve 5, facing the electrostatic image holding section 4.
Gauss), and the distance between the developing sleeve 5 and the electrostatic image holder 4 is maintained at 300 μm by spacer rollers arranged at both ends of the sleeve. Alternatively, it is a blade made of a magnetic material, and regulates the developer 9 of the present invention in the hopper 8 to a desired thickness. The toner is mainly triboelectrically charged between it and the developing sleeve 5. Opposing this blade 7 made of a magnetic material or magnet, one magnetic pole of a magnetic roll 6 (for example, N1 pole 850 Gauss in the illustrated example) is arranged inside the developing sleeve 5. In this case, the developing sleeve 5
The distance between the blade 7 made of magnetic material and
The thickness of the layer of the developer 9 of the present invention on the developing sleeve 5 is regulated by a magnetic field between the blade 7 made of a magnetic material and the developing sleeve 5. The direction of rotation of the developing sleeve 5 is the same as the direction of rotation of the photoreceptor, as shown in the figure. In the figure, 10 is a scraper blade for scraping off residual developer on the sleeve 5, and 11 is a power source for forming an alternating electric field between the sleeve 5 and the photosensitive drum 4, which is a pulse wave, alternating current, Generates a voltage that is a combination of alternating current and direct current. In this example, a power supply in which +200V DC bias was superimposed on 1000V PP AC was used. Incidentally, the latent image potential on the photosensitive drum 4 was +500V in the image area and OV in the non-image area.
使用したトナーは次の通りのものである。 The toner used was as follows.
ポリエステル樹脂（融点106℃） 100重量部
ローダミンレーキ顔料 ４重量部
Ｃ・Ｉソノレベント・レツド５２に分類されて
いるアントラキノン系染料、 ２重量部
以上をボールミルで混合粉砕した後、ロールミ
ルで溶融混練し、冷却した後ハンマーミルを用い
て粗粉砕し、次いでエアージエツト方式による微
粉砕機で微粉砕する。得られた微粉砕物を分級し
て５〜20μを選択し、これをトナーとした。これ
はマゼンタのカラートナーである。Polyester resin (melting point 106°C) 100 parts by weight Rhodamine lake pigment 4 parts by weight Anthraquinone dye classified as C/I Sonorevent Red 52 2 parts by weight or more were mixed and ground in a ball mill, then melted and kneaded in a roll mill. After cooling, it is coarsely pulverized using a hammer mill, and then finely pulverized using an air jet type pulverizer. The obtained finely pulverized product was classified to select 5 to 20 microns, which was used as a toner. This is a magenta color toner.
使用したキヤリア粒子は、
(1) ミノルタ(株)社製EG101複写機用トナー
(2) シヤープ(株)社製SF730複写機用トナー
(3) マグネタイト 100部
エポキシ樹脂 100部
を前述のトナーと同様に溶融混練、粉砕、分級
し、得られた粉体に４重量パーセントのカーボン
ブラツクを加えて熱風中で処理したもの。 The carrier particles used were: (1) Minolta Co., Ltd. EG101 copier toner (2) Sharp Co., Ltd. SF730 copier toner (3) Magnetite 100 parts Epoxy resin 100 parts Same as the above toner. 4% by weight of carbon black was added to the resulting powder and treated in hot air.
以上の３種を使用したが、これらの間には顕著
な差異は認められなかつた。以下の実験の説明に
当つてはこれら３種の現像剤について殊に区別し
ては述べない。 Although the above three types were used, no significant difference was observed between them. In the following description of the experiment, these three types of developer will not be particularly distinguished.
この３種の内(2)の現像剤は比較的抵抗が高く、
粉体を加圧しない状態で電極間に挾み抵抗値を測
定したところ、1000V／cmの電界下で1012Ωcm、
10000V／cmの電界下で、109Ωcmの抵抗値であつ
た。しかし、これは静電荷を保持するほどに高抵
抗とは言えず、導電性と見なされる。 Of these three types, developer (2) has relatively high resistance;
When the resistance value was measured by sandwiching the powder between electrodes without applying pressure, it was 10 12 Ωcm under an electric field of 1000V/cm,
Under an electric field of 10,000 V/cm, the resistance value was 10 9 Ωcm. However, it is not highly resistive enough to hold a static charge and is considered conductive.
(3)の現像剤は1000V／cmの電界下で106Ωcm以
下であり、比較的低抵抗である。尚前述のトナー
は同様の測定法で10000V／cmの電界下で1013Ω
cm以上の抵抗値を示し測定不能であつた。 The developer (3) has a relatively low resistance of 10 6 Ωcm or less under an electric field of 1000 V/cm. The above-mentioned toner has a resistance of 10 13 Ω under an electric field of 10000 V/cm using the same measurement method.
The resistance value exceeded cm and was impossible to measure.
以上のトナーとキヤリアを混合して現像剤とし
た用いたところ、トナーとキヤリアの混合比が、
重量比は１：４乃至１：１の時、ほぼ良好な画像
得られたが、現像剤支持部材上の現像剤層に若干
のムラが見られ、それにともなつて画像にわずか
にムラが発生した。 When the above toner and carrier were mixed and used as a developer, the mixing ratio of toner and carrier was as follows.
When the weight ratio was 1:4 to 1:1, almost good images were obtained, but some unevenness was observed in the developer layer on the developer support member, resulting in slight unevenness in the images. did.
そこで、スクレーパー１０をはずし、現像剤支
持部材を本出願人が先に提案した特願昭55−
16453号明細書に記された通り、支持部材表面を
粗したものに交換した。その結果、ムラがなく良
好な画像が得られた。 Therefore, the scraper 10 was removed and the developer support member was replaced with a
As described in the specification of No. 16453, the support member was replaced with one whose surface was roughened. As a result, a good image without unevenness was obtained.
ここで、現像器内の現像剤と同量程度のトナー
をホツパー内に追加したが、同様に良画像が得ら
れた。これは、現像剤支持部材上のキヤリア粒子
が、磁力により現像剤支持部材に吸引されてお
り、新たにホツパー内に加えられたトナーとは混
合されず、ホツパー内のトナーが必要量だけキヤ
リア粒子に付着するためである。これらいずれろ
場合にも、潜像保持部材上にはキヤリア粒子の付
着は見られなかつた。 At this time, approximately the same amount of toner as the developer in the developing device was added to the hopper, but good images were similarly obtained. This is because the carrier particles on the developer support member are attracted to the developer support member by magnetic force, and are not mixed with the newly added toner in the hopper. This is because it adheres to. In any of these cases, no carrier particles were observed to adhere to the latent image holding member.
尚、現像器に加えられたバイアス電圧を切り、
現像器を接地したところ、一応現像は可能であつ
た。しかし、画質はバイアスを加えたものよりも
劣るものであつた。 In addition, turn off the bias voltage applied to the developing device,
When the developing device was grounded, development was possible. However, the image quality was inferior to that with bias added.
また、キヤリア粒子として前述の例の他、通常
の２成分磁気ブラシ現像に用いられる。表面を窒
化処理した鉄粉（粒径は約50〜100μ）を用いた
が、満足な画像が得られなかつた。これはキヤリ
ア粒子の粒径が大きいため、トナー粒子との混合
が不十分になり易いからであると思われる。又マ
グネタイト粉（粒径は0.2μ程度）を用いると、現
像像に多量のキヤリア粒子をふくむものとなつ
た。これは粒径がトナー粒子に比べてあまりに小
さいため、現像行程でトナー粒子とキヤリア粒子
が十分に分離されないためであると思われる。ト
ナー粒子と、キヤリア粒子の大きさは比較的近い
ものである事がのぞましい。実験によれば、両者
の大きさの比は略１：３以内程度の時、良好であ
る。この場合トナー粒子とキヤリア粒子のいずれ
が大きくても良い。 Further, in addition to the above-mentioned examples as carrier particles, they are used in ordinary two-component magnetic brush development. Although we used iron powder (particle size: approximately 50 to 100 μm) whose surface was nitrided, a satisfactory image could not be obtained. This is believed to be because carrier particles have a large particle size and tend to be insufficiently mixed with toner particles. Furthermore, when magnetite powder (particle size is about 0.2 μm) was used, the developed image contained a large amount of carrier particles. This is believed to be because the particle size is too small compared to the toner particles, and the toner particles and carrier particles are not sufficiently separated during the development process. It is desirable that the toner particles and carrier particles are relatively similar in size. According to experiments, it is good when the ratio of both sizes is within about 1:3. In this case, either the toner particles or the carrier particles may be large.
以上詳細に述べたように本発明では、絶縁性ト
ナーと導電性及び磁性を有する微小な粉体を混合
し、これを背面に磁石を有する現像剤支持部材上
に均一に塗布し、これを潜像保持部材に接触させ
る事なく対向せしめて現像するようにしたから、
トナーの定着性も良好であり、カラートナーも使
用可能である。 As described in detail above, in the present invention, an insulating toner is mixed with conductive and magnetic fine powder, and this is uniformly applied onto a developer support member having a magnet on the back surface, and this is coated in a latent manner. Because the image is developed by facing the image holding member without contacting it,
The toner fixability is also good, and color toners can also be used.
第１図は潜像電位に対するトナー転移量及びト
ナー逆転移度の特性及び印加電圧波形の一例を示
す説明図、第２図Ａ〜Ｃは本発明に係る現像方法
の過程における現像剤の移動と印加電圧波形を模
式的に表わした過程説明図、第３図は本発明の実
施例を示す現像装置の断面図である。
図において、４……静電像保持体、５……現像
スリーブ、６……固定マグネツト・ロール、７…
…磁性体ブレード、８……ホツパー、９……現像
剤、１０……スクレーパー、１１……バイアス電
源、を表わす。
FIG. 1 is an explanatory diagram showing an example of the characteristics of the toner transfer amount and toner reverse transfer degree with respect to the latent image potential, and the applied voltage waveform. FIG. 3 is a process explanatory diagram schematically showing applied voltage waveforms, and FIG. 3 is a sectional view of a developing device showing an embodiment of the present invention. In the figure, 4...electrostatic image holder, 5...developing sleeve, 6...fixed magnet roll, 7...
...Magnetic blade, 8...Hopper, 9...Developer, 10...Scraper, 11...Bias power supply.
Claims (1)
以内である絶縁性トナーと導電性及び磁性を有す
る粉体を重量比で１：４乃至１：１で混合した現
像剤を現像剤担持体に供給し、この現像剤を現像
剤担持体上に現像剤規制手段によつて現像位置に
おける現像剤担持体と像保持体との間隔よりも薄
く層状に塗布し、この現像剤層を現像剤担持体内
に配置された磁石の磁極が像保持体に対向してい
る現像位置へ運び、現像位置において、上記現像
剤担持体と像保持体との間〓に交番電界を形成し
て絶縁性トナーを像保持体に付着、離脱させると
ともに、導電性磁性粉体を像保持体に付着、離脱
させて現像を行なうことを特徴とする現像方法。1 If one is larger, the size ratio is 1:3
A developer prepared by mixing an insulating toner with conductive and magnetic powder at a weight ratio of 1:4 to 1:1 is supplied to the developer carrier, and this developer is placed on the developer carrier. The developer regulating means applies the developer layer in a layer thinner than the gap between the developer carrier and the image carrier at the development position, and the magnetic pole of a magnet placed inside the developer carrier applies this developer layer to the image carrier. At the developing position, an alternating electric field is formed between the developer carrier and the image carrier to cause the insulating toner to adhere to and detach from the image carrier, and the conductive toner A developing method characterized by developing by adhering powder to and detaching from an image carrier.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP16661581A JPS5868051A (en) | 1981-10-19 | 1981-10-19 | Developing method |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP16661581A JPS5868051A (en) | 1981-10-19 | 1981-10-19 | Developing method |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS5868051A JPS5868051A (en) | 1983-04-22 |
| JPH038542B2 true JPH038542B2 (en) | 1991-02-06 |
Family
ID=15834587
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP16661581A Granted JPS5868051A (en) | 1981-10-19 | 1981-10-19 | Developing method |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS5868051A (en) |
Families Citing this family (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS59121077A (en) * | 1982-12-28 | 1984-07-12 | Toshiba Corp | Electrostatic latent image developing device |
| US5669050A (en) * | 1993-12-29 | 1997-09-16 | Canon Kabushiki Kaisha | Developing apparatus using blank pulse bias |
| JP2003255694A (en) | 2002-02-28 | 2003-09-10 | Canon Inc | Developing device and image forming apparatus |
-
1981
- 1981-10-19 JP JP16661581A patent/JPS5868051A/en active Granted
Also Published As
| Publication number | Publication date |
|---|---|
| JPS5868051A (en) | 1983-04-22 |
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