JPH02306278A - Image transfer device - Google Patents
Image transfer deviceInfo
- Publication number
- JPH02306278A JPH02306278A JP12752289A JP12752289A JPH02306278A JP H02306278 A JPH02306278 A JP H02306278A JP 12752289 A JP12752289 A JP 12752289A JP 12752289 A JP12752289 A JP 12752289A JP H02306278 A JPH02306278 A JP H02306278A
- Authority
- JP
- Japan
- Prior art keywords
- transfer
- toner
- surface tension
- transfer roller
- developer
- 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
- 239000002344 surface layer Substances 0.000 claims abstract description 8
- 239000000463 material Substances 0.000 claims description 28
- 239000007788 liquid Substances 0.000 abstract description 4
- 239000007787 solid Substances 0.000 abstract description 3
- 230000007547 defect Effects 0.000 abstract 1
- 239000010410 layer Substances 0.000 description 44
- 238000000034 method Methods 0.000 description 21
- 229920001971 elastomer Polymers 0.000 description 12
- 238000004140 cleaning Methods 0.000 description 6
- -1 polyhexafluoropropylene Polymers 0.000 description 6
- 229920005989 resin Polymers 0.000 description 6
- 239000011347 resin Substances 0.000 description 6
- 239000006260 foam Substances 0.000 description 5
- 108091008695 photoreceptors Proteins 0.000 description 5
- 230000000694 effects Effects 0.000 description 4
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 3
- JOYRKODLDBILNP-UHFFFAOYSA-N Ethyl urethane Chemical compound CCOC(N)=O JOYRKODLDBILNP-UHFFFAOYSA-N 0.000 description 3
- 239000000853 adhesive Substances 0.000 description 3
- 230000001070 adhesive effect Effects 0.000 description 3
- 229910052799 carbon Inorganic materials 0.000 description 3
- 230000005684 electric field Effects 0.000 description 3
- 230000007613 environmental effect Effects 0.000 description 3
- 239000002184 metal Substances 0.000 description 3
- 229910052751 metal Inorganic materials 0.000 description 3
- 229920001225 polyester resin Polymers 0.000 description 3
- 239000004645 polyester resin Substances 0.000 description 3
- PXHVJJICTQNCMI-UHFFFAOYSA-N Nickel Chemical compound [Ni] PXHVJJICTQNCMI-UHFFFAOYSA-N 0.000 description 2
- 239000004698 Polyethylene Substances 0.000 description 2
- 230000007423 decrease Effects 0.000 description 2
- 238000010586 diagram Methods 0.000 description 2
- 239000010419 fine particle Substances 0.000 description 2
- 238000005187 foaming Methods 0.000 description 2
- 229920000573 polyethylene Polymers 0.000 description 2
- 238000010186 staining Methods 0.000 description 2
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 description 1
- 229910001111 Fine metal Inorganic materials 0.000 description 1
- OKKJLVBELUTLKV-UHFFFAOYSA-N Methanol Chemical group OC OKKJLVBELUTLKV-UHFFFAOYSA-N 0.000 description 1
- 239000002033 PVDF binder Substances 0.000 description 1
- 239000004372 Polyvinyl alcohol Substances 0.000 description 1
- 229920001328 Polyvinylidene chloride Polymers 0.000 description 1
- 239000003795 chemical substances by application Substances 0.000 description 1
- RRGUKTPIGVIEKM-UHFFFAOYSA-N cilostazol Chemical compound C=1C=C2NC(=O)CCC2=CC=1OCCCCC1=NN=NN1C1CCCCC1 RRGUKTPIGVIEKM-UHFFFAOYSA-N 0.000 description 1
- 239000000470 constituent Substances 0.000 description 1
- 238000011109 contamination Methods 0.000 description 1
- 229910052802 copper Inorganic materials 0.000 description 1
- 239000010949 copper Substances 0.000 description 1
- 230000005489 elastic deformation Effects 0.000 description 1
- 229920001821 foam rubber Polymers 0.000 description 1
- 238000002347 injection Methods 0.000 description 1
- 239000007924 injection Substances 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 239000002923 metal particle Substances 0.000 description 1
- 238000000465 moulding Methods 0.000 description 1
- 229910052759 nickel Inorganic materials 0.000 description 1
- 230000003287 optical effect Effects 0.000 description 1
- 230000000704 physical effect Effects 0.000 description 1
- 229920003023 plastic Polymers 0.000 description 1
- 239000004033 plastic Substances 0.000 description 1
- 229920000728 polyester Polymers 0.000 description 1
- 229920002635 polyurethane Polymers 0.000 description 1
- 239000004814 polyurethane Substances 0.000 description 1
- 229920005749 polyurethane resin Polymers 0.000 description 1
- 229920002451 polyvinyl alcohol Polymers 0.000 description 1
- 229920000915 polyvinyl chloride Polymers 0.000 description 1
- 239000004800 polyvinyl chloride Substances 0.000 description 1
- 229920002620 polyvinyl fluoride Polymers 0.000 description 1
- 239000005033 polyvinylidene chloride Substances 0.000 description 1
- 229920002981 polyvinylidene fluoride Polymers 0.000 description 1
- 238000003825 pressing Methods 0.000 description 1
- 239000002356 single layer Substances 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
- KKEYFWRCBNTPAC-UHFFFAOYSA-L terephthalate(2-) Chemical compound [O-]C(=O)C1=CC=C(C([O-])=O)C=C1 KKEYFWRCBNTPAC-UHFFFAOYSA-L 0.000 description 1
Landscapes
- Dry Development In Electrophotography (AREA)
- Electrostatic Charge, Transfer And Separation In Electrography (AREA)
Abstract
Description
【発明の詳細な説明】
[発明の目的]
(産業上の利用分野)
本発明は、たとえば、電子写真装置などに備えられる画
像転写装置に関する。DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial Application Field) The present invention relates to an image transfer device included in, for example, an electrophotographic device.
(従来の技術)
現在、電子写真装置などにおいては、感光体などの像担
持体上に形成された画像を、紙などの被転写材に転写す
るようになっているが、この転写方式として、主にコロ
ナチャージャを用いる方式(コロナ転写方式)が使用さ
れている。(Prior Art) Currently, in electrophotographic devices, an image formed on an image carrier such as a photoreceptor is transferred to a transfer material such as paper. A method using a corona charger (corona transfer method) is mainly used.
この方式では、被転写材の背面からコロナチャージャで
電荷を発生させ被転写材に付着した電荷により生じる電
界によりトナーをトナー像担持体より被転写材に転写す
る。この方式はコロナチャージャーによる電荷の発生量
は同じでも、被転写材の電気抵抗により、電荷付着:が
異なり電界の強さが変化するため、トナーの転写効率が
変化する。この為、一般に被転写材として使用される普
通紙は多湿環境において、吸湿し、電気抵抗が大きく減
少するから、転写不良を生じるという問題があった。In this method, charges are generated by a corona charger from the back side of the transfer material, and toner is transferred from the toner image carrier to the transfer material using an electric field generated by the charges attached to the transfer material. In this method, even though the amount of charge generated by the corona charger is the same, the charge adhesion varies depending on the electrical resistance of the transferred material, and the strength of the electric field changes, so the toner transfer efficiency changes. For this reason, plain paper, which is generally used as a transfer material, absorbs moisture in a humid environment and its electrical resistance is greatly reduced, resulting in a problem of poor transfer.
また、被転写材がトナー像担持体と接触するとき、ある
いは、離脱するときに、被転写材の帯電電荷にる気体放
電が生じて被転写材に転写されたトナーが飛散し、画像
が乱れるという問題もあった。In addition, when the transfer material comes into contact with the toner image carrier or separates from the toner image carrier, a gas discharge occurs due to the charged charge on the transfer material, and the toner transferred to the transfer material scatters, causing the image to become distorted. There was also the problem.
更に、−コロナ;゛ヤージャに高圧を発生させるための
高価な電源も必要になるという問題があった。Furthermore, there is a problem in that an expensive power source is required to generate high voltage in the corona charger.
これらの問題を解決するため、転写部材を像担持体に押
圧して圧力により画像を転写させる方法、さらに、弾性
を有した転写部材を像担持体に押圧してバイアス電圧を
印加し、圧力および静電気力により転写させる方法など
が考案さている。In order to solve these problems, we have developed a method in which a transfer member is pressed against an image carrier and the image is transferred by pressure.Furthermore, a transfer member with elasticity is pressed against the image carrier and a bias voltage is applied, and pressure and pressure are applied. A method of transferring using electrostatic force has been devised.
特に、弾性を有した転写部材を像担持体に押圧し、バイ
アス電圧を印加し圧力および静電気力により転写させる
方法は、画像の飛散もなく、環境安定性も良く、像担持
体を傷付けずに良好な転写を行なうことができる。In particular, a method in which an elastic transfer member is pressed against an image carrier, a bias voltage is applied, and the image is transferred by pressure and electrostatic force is free from scattering, has good environmental stability, and does not damage the image carrier. Good transfer can be performed.
しかしながら、この転写部すは、像担持体上にトナー像
形成可能な幅と同等あるいはそれ以上の幅を持って常に
像担持体に接しているため、被転写材の幅よりも大きい
像担持体上の不要画像部のトナーが転写部材に直接転写
され、転写部材に汚れを生じる。However, since this transfer section is always in contact with the image carrier with a width equal to or greater than the width that can form a toner image on the image carrier, the image carrier is larger than the width of the transferred material. The toner in the upper unnecessary image area is directly transferred to the transfer member, causing stains on the transfer member.
また、゛転写部材の搬送ミス発生時には像担持体上のト
ナー画像部てが転写部材に付着する。Further, when a transfer error occurs in the transfer member, the toner image portion on the image carrier adheres to the transfer member.
さらに、装置が正常に運転している場合でも、浮遊トナ
ーの付着で転写部材が汚れる。この転写部材上のトナー
汚れにより、被転写材の裏汚れが生じるだけでなく、絶
縁性トナーが転写部材に付着することで転写ムラの原因
になるという問題が ・あった。Further, even when the apparatus is operating normally, the transfer member becomes contaminated with adhesion of floating toner. This toner stain on the transfer member not only causes stains on the back side of the transfer material, but also causes problems in that the insulating toner adheres to the transfer member, causing uneven transfer.
これらの聞届の解決のために、転写部材に付着したトナ
ーを除去する手段が考案されている。In order to solve these problems, means have been devised to remove the toner adhering to the transfer member.
第1の方法は転写部材にブレード、ブラシ、フェルトな
どを接触させ、付着トナーを掻き取る方法であり、第2
の方法は極性制御用チャージャーを用いることにより、
転写部材上に付着したトナーを像担持体上に逆転写させ
る方法である。The first method is to bring a blade, brush, felt, etc. into contact with the transfer member and scrape off the adhered toner.
This method uses a polarity control charger,
This is a method in which toner adhering to a transfer member is reversely transferred onto an image carrier.
これらのクリーニング法により転写部材の汚れは、軽減
された。These cleaning methods reduced staining on the transfer member.
(発明が解決しようする課題)
しかしながら、第1の方法においては、転写部材の表面
に存在する凹部へ付着したトナーは掻き取ることができ
ず、第2の方法においては、生じる電界の力に抗するフ
ァンデールワースカをもつトナーは像担持体へ逆転写さ
せることができず、転写部材上に残ってしまい、装置の
長期使用によって転写部材へのトナー付着から生じる被
転写材の裏汚れ、転写ムラ等の問題点が発生した。(Problem to be Solved by the Invention) However, in the first method, the toner adhering to the recesses existing on the surface of the transfer member cannot be scraped off, and in the second method, the toner cannot be scraped off by resisting the force of the electric field generated. Toner with van der Werska cannot be reverse transferred to the image bearing member and remains on the transfer member, and when the device is used for a long period of time, toner adhesion to the transfer member may cause stains on the back of the transfer material and transfer. Problems such as unevenness occurred.
[発明の構成コ
(課題を解決するための手段)
本発明は上記課題を解決するために、転写部材にその表
面層の臨界表面張力をrR,現像剤の臨界表面張力をr
Tとしたとき、
lrRrrl≧5 [dyne 會cm−1]の関係を
持たせるようにした。[Structure of the Invention (Means for Solving the Problems)] In order to solve the above problems, the present invention provides a transfer member with the critical surface tension of its surface layer rR and the critical surface tension of the developer as rR.
When T, the relationship lrRrrl≧5 [dyne cm-1] is established.
(作 用)
上記手段により、転写部材に対する現像剤の付着力を低
下させ、転写部材に残留した現像剤を容易に像担持体に
逆転写できるようにした。(Function) By the above means, the adhesive force of the developer to the transfer member is reduced, and the developer remaining on the transfer member can be easily reversely transferred to the image carrier.
(実施例)
以下、本発明を図面に示す一実施例を参照して説明する
。(Example) The present invention will be described below with reference to an example shown in the drawings.
第1図は転写部材としての転写ローラ5を示すものであ
る。この転写ローラ5は抵抗性表面層1と、導電層2と
、弾性的に変形可能な弾性層3とによって構成されてい
る。4は金属シャフトである。上記抵抗性表面層1はポ
リへキサフルオロプロピレン、ポリテトラオロエチレン
、ポリトリフルオロエチレン、ポリビニリデンフルオラ
イド、ポリビニルフルオライド等のフッ素樹脂、ポリビ
ニルアルコール、メチルメタクリレート、ポリビニルク
ロライド、ポリビニリデンクロライド、ポリエチレンテ
レフタレート等の樹脂、ポリウレタ等のゴムに導電性カ
ーボン、銅、ニッケル等の微細金属粒子等導電性物質を
分散させたものなどを用いることができる。FIG. 1 shows a transfer roller 5 as a transfer member. The transfer roller 5 is composed of a resistive surface layer 1, a conductive layer 2, and an elastic layer 3 which is elastically deformable. 4 is a metal shaft. The above-mentioned resistive surface layer 1 is made of fluororesins such as polyhexafluoropropylene, polytetraoethylene, polytrifluoroethylene, polyvinylidene fluoride, polyvinyl fluoride, polyvinyl alcohol, methyl methacrylate, polyvinyl chloride, polyvinylidene chloride, polyethylene, etc. A resin such as terephthalate or a rubber such as polyurethane in which conductive substances such as conductive carbon, fine metal particles such as copper or nickel are dispersed can be used.
上記表面抵抗層1の体積抵抗値は後述するように105
〜1015Ω印の範囲が望ましく、特に、106〜10
12Ω印の範囲が好適に用いられる。The volume resistivity value of the surface resistance layer 1 is 105 as described later.
The range of ~1015Ω mark is desirable, especially 106~10
The range marked by 12Ω is preferably used.
このような体積抵抗値の制御は樹脂あるいはゴムへの導
電性微粒子の混合率を変えることにより、容易になされ
る。Such volume resistance value can be easily controlled by changing the mixing ratio of conductive fine particles to the resin or rubber.
また、表面抵抗性層1の体積抵抗値は外部からの圧力お
よび/あるいは温度、湿度などの環境条件の変化に対し
て変わらないか、あるいは、その変化が小さいことが望
ましい。樹脂シート構造は内部に空気室を持たないので
発砲構造と比較して温度に対して抵抗値は安定している
。このような特性を持つことにより、紙、封書、葉書な
ど厚みの異なる転写材が圧接状態にあるトナー像担持体
と転写ローラの間に入ってきても、あるいは温湿度に係
わらず、電気的トナー転写条件を同じに維持することが
できる。Further, it is preferable that the volume resistivity of the surface resistive layer 1 does not change or changes only slightly in response to changes in external pressure and/or environmental conditions such as temperature and humidity. Since the resin sheet structure does not have an internal air chamber, the resistance value is more stable with respect to temperature than the foam structure. With these characteristics, even if transfer materials of different thicknesses such as paper, envelopes, postcards, etc. come between the toner image carrier and the transfer roller that are in pressure contact, or regardless of the temperature or humidity, the electric toner Transfer conditions can be kept the same.
表面抵抗性層1の厚みは弾性層3の柔軟性を損わぬため
にできるだけ薄い方が良く、0.02〜2市の範囲が良
い。前記導電層3はポリエステルなどに導電性カーボン
などを導電性微粒子を分散させた導電性樹脂、金属の薄
いシートあるいは、導電性接着材などを用いることがで
き、導電性と可とう性が必要である。The thickness of the surface resistive layer 1 is preferably as thin as possible in order not to impair the flexibility of the elastic layer 3, and is preferably in the range of 0.02 to 2 mm. The conductive layer 3 can be made of a conductive resin such as polyester with conductive fine particles such as conductive carbon dispersed therein, a thin sheet of metal, or a conductive adhesive, and must have conductivity and flexibility. be.
体積抵抗値は表面抵抗性層1のそれより低くしなければ
ならず、10うΩ叩以下である。また、上記導電性層2
と表面抵抗性層1は電気的な接続が確保されなければな
らない導電層2の厚みも弾性層3の柔軟性を損わないた
めにできるだけ薄い方が良い。上記表面抵抗性層1と導
電層2の厚みの和を弾性層3の厚みの1/10以下にす
ることにより弾性層3の機能は維持される。弾力的に変
形可能な弾性層3は発砲ゴムスポンジ、発砲ポリエチレ
ン、発砲ウレタンなど、圧縮変形可能な弾性体を利用で
きる。The volume resistivity value must be lower than that of the surface resistive layer 1, less than 10Ω. Further, the conductive layer 2
The thickness of the conductive layer 2, which must ensure electrical connection with the surface resistive layer 1, is preferably as thin as possible so as not to impair the flexibility of the elastic layer 3. By setting the sum of the thicknesses of the surface resistive layer 1 and the conductive layer 2 to 1/10 or less of the thickness of the elastic layer 3, the function of the elastic layer 3 is maintained. The elastic layer 3 that can be elastically deformed can be made of an elastic body that can be compressed and deformed, such as foamed rubber sponge, foamed polyethylene, or foamed urethane.
上記転写a−ラ5はトナー像担持体に一部を圧接して用
いられるので、弾性層3は圧接時に柔軟に変形し、圧接
開放時にはすみやかに原型に復元する必要があり、かつ
、この繰返しに対し、安定に動作することが必要である
。すなわち、耐クリープ、耐塑性変形に優れた材料が望
ましい。発砲構造としては、連続発砲(連泡)構造、独
立気泡構造などいずれの構造も用いることができるが、
連泡構造は周囲温度に係わらず、形状が安定しているの
で、好適に使用することができる。Since the transfer a-ra 5 is used by partially pressing the toner image carrier, the elastic layer 3 needs to be flexibly deformed when the pressure is applied, and quickly return to its original shape when the pressure is released. However, it is necessary to operate stably. That is, a material with excellent creep resistance and plastic deformation resistance is desirable. As the foam structure, any structure such as continuous foam (open cell) structure or closed cell structure can be used.
Since the open cell structure has a stable shape regardless of the ambient temperature, it can be suitably used.
上記弾性層3の柔軟性は構成材料、発砲構造、発砲の程
度などを変えることにより任意のものを得ることが可能
であり、独立気泡構造のスポンジゴム硬度30と同等以
下の硬度が好適に用いられる。Any flexibility can be obtained for the elastic layer 3 by changing the constituent materials, foaming structure, degree of foaming, etc., and a hardness equal to or lower than a sponge rubber hardness of closed cell structure of 30 is preferably used. It will be done.
また、上記弾性層3を端部より導電処理することにより
、一部を導電性弾性層6とすることもできる。前記導電
性弾性層6は導電層2とシャフト4を電気的に接続し、
シャフト4に給電することにより、表面抵抗性層1に電
圧を印加することが可能となる。また、第2図に示すよ
うに、導電層2の一部を露出させ、その部分より給電す
ることも可能である。弾性層3の厚みは薄過ぎると柔軟
構造が機能しないので、2■以上の厚みが必要である。In addition, a part of the elastic layer 3 can be made into the conductive elastic layer 6 by subjecting the elastic layer 3 to conductive treatment from the end. The conductive elastic layer 6 electrically connects the conductive layer 2 and the shaft 4,
By supplying power to the shaft 4, it becomes possible to apply a voltage to the surface resistive layer 1. Furthermore, as shown in FIG. 2, it is also possible to expose a part of the conductive layer 2 and supply power from that part. If the thickness of the elastic layer 3 is too thin, the flexible structure will not function, so it is necessary to have a thickness of 2 mm or more.
第1図に示した転写ローラ5の製法を簡単に説明する。A method for manufacturing the transfer roller 5 shown in FIG. 1 will be briefly described.
φ8 mrsのSUSシャフトの周囲にゴム硬度20の
発砲ウレタンを注型により厚さ10a+mに形成した。A urethane foam having a rubber hardness of 20 was cast to a thickness of 10 a+m around a SUS shaft having a diameter of 8 mrs.
このスポンジローラの両端より導電処理をして発砲ウレ
タンの両端的51の幅で体積抵抗値104Ω印導電性ス
ポンジ層を形成した。さらに、この上に、導電カーボン
をポリエステル樹脂に分散さ
せ、体積抵抗値を107Ω(至)に調整した導電層1及
び体積抵抗値101°Ω印を調整した抵抗性層を各々0
.1n+mの厚さに注型形成した。Both ends of this sponge roller were subjected to conductive treatment to form a conductive sponge layer having a volume resistivity of 104Ω and having a width of 51 at both ends of the urethane foam. Further, on top of this, a conductive layer 1 in which conductive carbon is dispersed in a polyester resin and a volume resistance value adjusted to 107Ω (maximum) and a resistive layer 1 in which a volume resistance value adjusted to a 101°Ω mark are formed.
.. Cast molding was performed to a thickness of 1n+m.
つぎに、第1図に示した転写ローラ5を用いたこの発明
に係わるトナー転写装置の一実施例の動作を第3図を用
いて説明する。Next, the operation of an embodiment of the toner transfer device according to the present invention using the transfer roller 5 shown in FIG. 1 will be described with reference to FIG.
トナー像担持体7上のトナー像8はトナー像担持体7の
回転(矢印方向)に従って、トナー転写部(B−0間)
に移送される。トナー転写部でトナー像8は被転写材で
ある普通紙9に圧接される。The toner image 8 on the toner image carrier 7 is transferred to the toner transfer portion (between B and 0) as the toner image carrier 7 rotates (in the direction of the arrow).
will be transferred to. At the toner transfer section, the toner image 8 is pressed against plain paper 9, which is a transfer material.
この間、トナー98には高圧発生回路1oにより供給さ
れるトナー像8の電荷と(この図では負極性)と逆極性
の高圧の転写電圧約1kv〜3kvが作用し、トナー像
8は静電的に普通紙9に転写され、普通紙9上に画像を
形成する。During this time, a high transfer voltage of approximately 1 kV to 3 kV having a polarity opposite to that of the toner image 8 (negative polarity in this figure) supplied by the high voltage generation circuit 1o acts on the toner 98, and the toner image 8 is electrostatically is transferred to plain paper 9 to form an image on plain paper 9.
トナー転写部(B−C区間)では、転写ローラ5の弾性
層3の弾力的な変形により、トナー担持体7と普通紙9
は密着し、幅広いニップ幅を形成する。この領域では、
弾性層3の柔軟な構造により、転写圧力もほぼ一定に保
つことができる。In the toner transfer section (B-C section), due to the elastic deformation of the elastic layer 3 of the transfer roller 5, the toner carrier 7 and the plain paper 9
are in close contact and form a wide nip width. In this area,
Due to the flexible structure of the elastic layer 3, the transfer pressure can also be kept almost constant.
また、抵抗性層1は体積抵抗値の圧力依存性がほとんど
ないので、ニップ幅の全領域において、均一な転写条件
を得ることが可能である。Furthermore, since the volume resistivity of the resistive layer 1 has almost no pressure dependence, it is possible to obtain uniform transfer conditions over the entire nip width region.
ローラ転写では、転写圧力が大き過ぎると、トナー像の
中央部のトナーが転写材に転写されない現象を生じ。例
えば、文字記録では、白抜き文字、すなわち、文字形の
ワタのみが記録される。第5図に第3図のトナー転写装
置を用いたときの転写圧力と中抜けの生じる割合いとの
関係を示す。In roller transfer, if the transfer pressure is too high, a phenomenon occurs in which the toner in the center of the toner image is not transferred to the transfer material. For example, in character recording, only outline characters, that is, the outline of the character shape, are recorded. FIG. 5 shows the relationship between the transfer pressure and the rate of occurrence of voids when the toner transfer device of FIG. 3 is used.
中抜けの現われる割合いは正方形の孤立したトナー像を
転写し、得られた転写像中の白地部分の全体像に占める
割合で示した。中抜けの出現割合が10%以下であれば
事実上、問題のない転写像が得られる。The rate at which hollow areas appear is expressed by transferring a square isolated toner image and expressing the proportion of the white area in the resulting transferred image to the overall image. If the appearance rate of hollow spots is 10% or less, a transfer image with virtually no problems can be obtained.
しかし、転写圧力が低すぎると、ニップ幅が狭くなり、
転写濃度が低下する。However, if the transfer pressure is too low, the nip width will become narrower.
Transfer density decreases.
この発明になるトナー転写装置では、20〜300 g
/ cdの範囲の転写圧力が適しており、好ましくは
、20〜200 g / cdの範囲の転写圧力が用い
られる。転写ローラ5の弾性層のゴム硬度が30以下の
場合は、第5図に示したような、関係が保たれるが、ゴ
ム硬度が30以上になると、弾性的に変形する機能が低
下するため、転写圧力は小さくしなければならない。例
えば、ゴム硬度的45の場合には転写圧力20〜50
g / cdの範囲しか用いることができない。第6図
に環境温度をパラメータに転写ローラの抵抗性層を体積
抵抗値とトナーの転写効率の関係を示す。In the toner transfer device of this invention, 20 to 300 g
Transfer pressures in the range of g/cd are suitable, preferably transfer pressures in the range of 20 to 200 g/cd are used. When the rubber hardness of the elastic layer of the transfer roller 5 is 30 or less, the relationship shown in FIG. 5 is maintained, but when the rubber hardness becomes 30 or more, the ability to elastically deform is reduced. , the transfer pressure must be small. For example, if the rubber hardness is 45, the transfer pressure is 20 to 50.
Only the g/cd range can be used. FIG. 6 shows the relationship between the volume resistance value of the resistive layer of the transfer roller and the toner transfer efficiency using the environmental temperature as a parameter.
トナーの転写効率は転写材に転写されたトナー量(転写
トナー量と呼す)の転写トナー量とトナー像担持体に残
ったトナー量の和に対する割合を百分率で現わしたもの
である。The toner transfer efficiency is expressed as a percentage of the amount of toner transferred to the transfer material (referred to as the amount of transferred toner) to the sum of the amount of transferred toner and the amount of toner remaining on the toner image carrier.
抵抗性層を形成する抵抗性樹脂シートは電気的特性のみ
を重視して設計できる。The resistive resin sheet forming the resistive layer can be designed with emphasis only on electrical properties.
抵抗性層の体積抵抗値が低過ぎると、転写電圧印加時に
トナー像担持体との間で放電を生じたり、電荷注入によ
る逆極性トナーが発生し、転写効率が著しく低下する。If the volume resistance value of the resistive layer is too low, discharge will occur between the resistive layer and the toner image carrier when a transfer voltage is applied, or toner of opposite polarity will be generated due to charge injection, resulting in a significant reduction in transfer efficiency.
また、体積抵抗値か高すぎると、トナ一層に分配される
転写電圧が低くなり、転写効率は低下する。Furthermore, if the volume resistance value is too high, the transfer voltage distributed to the toner layer becomes low, and the transfer efficiency decreases.
第6図に示されるように、この発明になる、トナー転写
装置の転写ローラの抵抗性層の体積抵抗値としては10
5〜10】5ΩCシの範囲が良く、特に106〜101
2ΩCシの範囲を好適に使用することができる。As shown in FIG. 6, the volume resistance value of the resistive layer of the transfer roller of the toner transfer device according to the present invention is 10.
5~10] The range of 5ΩC is good, especially 106~101
A range of 2ΩC can be suitably used.
この発明にかかる電極構成体としては、第4図に示すよ
うに、導電性樹脂シート2と発砲ゴムスポンジ層3との
間に導電性ゴム層3を設けた構成でもよい。この構成は
ポリエステル樹脂シート2と発砲ゴムスポンジ3との間
の接着力を強化する必要のある時に用いられる。The electrode structure according to the present invention may have a structure in which a conductive rubber layer 3 is provided between a conductive resin sheet 2 and a foamed rubber sponge layer 3, as shown in FIG. This configuration is used when it is necessary to strengthen the adhesive force between the polyester resin sheet 2 and the foamed rubber sponge 3.
1は抵抗性ポリエステル樹脂シート層、4は金属シャフ
ト、6は導電処理された発砲性ゴムスポンジである。Reference numeral 1 indicates a resistive polyester resin sheet layer, 4 a metal shaft, and 6 a conductive treated foam rubber sponge.
更に、本発明の手段であるところの仕事関数、体積抵抗
率の条件を満たすならば、弾性体の一層構造たとえば、
ポリウレタン樹脂、ゴム等であってもかまわない。Furthermore, if the conditions of work function and volume resistivity, which are the means of the present invention, are satisfied, a single layer structure of an elastic body, for example,
It may be made of polyurethane resin, rubber, etc.
つぎに、第7図を用いて本発明に係わるトナー転写装置
を電子写真装置に適用した実施例について説明する。こ
の図は反転現像装置を組込んだ電子写真装置を示す。有
機感光体(以後、opcという)21にチャージャー2
2を用いて負電荷23を与え、この負電荷23を有する
。PC上にレーザ光等による光信号24を照射し、反転
した静電潜像を形成させる。この静電潜像をopc上の
表面電位と同程度の600Vの負電圧でバイアス25さ
れた負極性のトナーを有する現像器26で現像し、可視
像27を0PC2i上に形成する。Next, an embodiment in which the toner transfer device according to the present invention is applied to an electrophotographic device will be described with reference to FIG. This figure shows an electrophotographic apparatus incorporating a reversal developing device. A charger 2 is attached to an organic photoreceptor (hereinafter referred to as OPC) 21.
2 is used to give a negative charge 23, and this negative charge 23 is possessed. An optical signal 24 such as a laser beam is irradiated onto the PC to form an inverted electrostatic latent image. This electrostatic latent image is developed with a developing device 26 having negative polarity toner biased 25 with a negative voltage of 600 V, which is about the same as the surface potential on the OPC, to form a visible image 27 on the OPC 2i.
一方、転写紙28は0PC21と転写ローラ5との間に
搬送され、2kv近辺の正電圧30が加えられた転写ロ
ーラー5によって転写され、転写紙28上にトナー画像
31を形成する。On the other hand, the transfer paper 28 is conveyed between the 0PC 21 and the transfer roller 5, and is transferred by the transfer roller 5 to which a positive voltage 30 of around 2 kV is applied, thereby forming a toner image 31 on the transfer paper 28.
一方、0PC21上に残留したトナーはクリーナ装置3
3で清掃され、かつ、感光体21」二の静電潜像は消去
ランプ34により消去されて、0PC21は再び使用さ
れる。On the other hand, the toner remaining on the 0PC21 is removed from the cleaner device 3.
3, and the electrostatic latent image on the photoconductor 21'' is erased by the erase lamp 34, and the 0PC 21 is used again.
転写ローラ5上に残留したトナーはOPC21に逆転写
される。The toner remaining on the transfer roller 5 is reversely transferred to the OPC 21.
0PC21への逆転等方については第8図(a)を用い
て以下に説明する。The isotropic reversal to 0PC21 will be explained below using FIG. 8(a).
転写ローラ5上に付着した負極性のトナーを5゜5kv
の正極性の電圧を印加できる極制御用チャージャー41
中を矢印B方向に通過させ正極性にする。この正極性に
変化したトナー42は転写ローラ5に加えられてる60
0Vの転写電圧と同一の電源43により0PC21上に
逆転写する。この0PC21上に逆転写したトナー42
はopc周辺に装置されているクリーニング装置33に
より清掃され、OPCは初期状態になる。また、トナー
42を感光体21上に逆転写した後の転写ローラ5はト
ナーが除去され再び使用できる。この一連の工程におけ
る0PC21上の残留電位は100V近辺存在してもよ
いが、より小さな電位であることが望ましい。The negative polarity toner adhering to the transfer roller 5 is heated to 5°5kv.
A polar control charger 41 that can apply a positive polarity voltage of
Pass through the inside in the direction of arrow B to make it positive polarity. This toner 42 changed to positive polarity is applied to the transfer roller 5 60
Reverse transfer is performed onto the 0PC21 using the same power source 43 as the transfer voltage of 0V. Toner 42 reversely transferred onto this 0PC21
is cleaned by a cleaning device 33 installed around the OPC, and the OPC returns to its initial state. Furthermore, after the toner 42 has been reversely transferred onto the photoreceptor 21, the transfer roller 5 is free of toner and can be used again. Although the residual potential on the 0PC21 in this series of steps may exist around 100V, it is desirable that the potential be smaller.
以上の転写ローラクリーニング行程中は作像行程は行わ
ず、0PC21を1回転移動する間にクリーニングを終
了する。この間現像器26の動作を停止しておくことで
、0PC21上のトナーの付着はなくなり、クリーニン
グ効果は上昇する。During the transfer roller cleaning process described above, the image forming process is not performed, and the cleaning is completed while the 0PC21 is moved one rotation. By stopping the operation of the developing device 26 during this time, toner does not adhere to the 0PC 21 and the cleaning effect is improved.
同図(b)は転写ローラ5に電圧を印加することなく、
転写ローラー5上の付着トナーを0PC21に逆転写さ
せる方式である。In the same figure (b), without applying voltage to the transfer roller 5,
This is a method in which the toner adhered on the transfer roller 5 is reversely transferred onto the 0PC21.
作像行程を終了しクリーニングを終えて清掃された0P
C21にメインチャージャー22により、作像行程と同
極性の負電荷で一600Vの表面電位が与えられる。こ
の0PC21は転写ローラ5に搬送される。0P cleaned after completing the image forming process and cleaning
A surface potential of -600 V is applied to C21 by the main charger 22 with a negative charge having the same polarity as that of the image forming process. This 0PC21 is conveyed to the transfer roller 5.
一方、転写ローラ5上の負極性の付着トナーは転写ロー
ラ5周辺に設けられたトナーの極性制御用チャージャ4
1にて正極性に変化され、負の表面電位を有する感光体
上に付着することでトナーの逆転写が終了する。このと
き転写ローラ5には正極性の電圧を印加する必要ははな
い。On the other hand, the negative polarity adhering toner on the transfer roller 5 is removed by a toner polarity control charger 4 provided around the transfer roller 5.
The reverse transfer of the toner is completed by changing the polarity to positive at step 1 and adhering to the photoreceptor having a negative surface potential. At this time, there is no need to apply a positive voltage to the transfer roller 5.
ところで、転写ローラ5にトナーが付着する際、その付
着力の強さを仕事Waで現わすとき、「粉体の表面科学
」 (小石、角田著 昭和50年11月日刊工業新聞)
に示されるように、
Wa−σRa+σT、−σRT(1)
σRa’転写部材の表面張力
σT、;トナーの表面張力
σl?T’転写ローラの界面張力
(aはエアーの意味)
また、この付着面をある液体(1)中で引離す仕事をW
a ’ とすると、
W a ’ ” (7Rp+ (7Tp (7RT
(2)更に、この液体を転写ローラ表面及びト
ナー表面上においたときの接触角をθ θ とする
Rga Tj!a
と、
(7Ra (7Rp−(7ハCOSθRpa’Ta−
aT(1−σΩaCoSθT j)a (3)し
たがって、(1)〜(3)より
W a −W a ’
一σ (cosθ +cosθTh ) (4)i
laRΩa
σ1a−AのときWa’ −0とすると、Wa
”A(cosθ +cosθTjlla )(5)1
?Qa
接触角Q とQ の差IQ −Q IRN
a Tpa RΩaTΩaが大きいと接着
仕事Waは小さくなる。By the way, when the toner adheres to the transfer roller 5, the strength of its adhesion is expressed by the work Wa.
As shown in, Wa-σRa+σT, -σRT (1) σRa'Surface tension of transfer member σT,;Surface tension of toner σl? T'The interfacial tension of the transfer roller (a means air) Also, the work of separating this adhering surface in a certain liquid (1) is W
a', W a''' (7Rp+ (7Tp (7RT
(2) Furthermore, Rga Tj! where the contact angle when this liquid is placed on the transfer roller surface and the toner surface is θ θ! a and (7Ra (7Rp-(7ha COSθRpa'Ta-
aT(1-σΩaCoSθT j)a (3) Therefore, from (1) to (3), W a −W a ' - (cosθ + cosθTh ) (4)i
If Wa′ −0 when laRΩa σ1a−A, then Wa ”A(cosθ +cosθTjlla )(5)1
? Qa Difference between contact angles Q and Q IQ −Q IRN
a Tpa RΩa When TΩa is large, the adhesion work Wa becomes small.
固体表面に液滴をおいた時の接触角は表面張力を相対的
に比較するときの良いパラメータであり、一方、固体の
表面張力を簡単に測定しうる物性値−臨海表面張力で表
現することができる。すなわち、2種類の物体の接触角
の差が大きい時、臨海表面張力の差も大きい。The contact angle when a droplet is placed on a solid surface is a good parameter for relative comparison of surface tension.On the other hand, the surface tension of a solid can be expressed as a physical property value that can be easily measured - critical surface tension. I can do it. That is, when the difference in contact angle between two types of objects is large, the difference in coastal surface tension is also large.
トナーと転写ローラとの接着仕事Waが小さいとき接着
強さもまた小さく、したがってトナーと転写ローラ5と
の臨海表面張力の差が大きいとき、トナーは転写ローラ
5に付着しにくいと言ことはできる。When the adhesion work Wa between the toner and the transfer roller is small, the adhesion strength is also small, and therefore, when the difference in critical surface tension between the toner and the transfer roller 5 is large, it can be said that the toner is difficult to adhere to the transfer roller 5.
以上説明したような写真装置を用いてA4標準サイズ画
像をIOK枚連続して複写し、転写ローラ5のトナー汚
染による被転写材(普通紙)の裏t15れを目視にて確
認した。IOK sheets of A4 standard size images were continuously copied using the photographic device as described above, and the back side t15 of the transfer material (plain paper) due to toner contamination of the transfer roller 5 was visually confirmed.
その結果、第1表に示すように、臨界表面張力「が使用
したトナーの臨界表面張力(32dyne/cm)から
5dyne/cm以上離れていると、表面層を持った転
写ローラを用いた場合、被転写材の裏汚れは発生しなか
った。As a result, as shown in Table 1, if the critical surface tension "is 5 dyne/cm or more away from the critical surface tension (32 dyne/cm) of the toner used, when a transfer roller with a surface layer is used, There was no staining on the back side of the transferred material.
これは、トナーと転写ローラ5の表面層の臨界表面張力
との差が大きいため、ぬれ性が悪く、トナーと転写ロー
ラ5間の付着力が弱いためである。This is because the difference in critical surface tension between the toner and the surface layer of the transfer roller 5 is large, resulting in poor wettability and weak adhesion between the toner and the transfer roller 5.
表
[発明の効果]
以上説明したように本発明によれば、トナーの転写部材
への付着力が非常に小さくなるため、トナー担持体上の
被転写材より幅の広い不要画像の転写、被転写材の搬送
ミス、浮遊トナーなどによっても転写部材が汚染される
ことがなく、被転写材の裏汚れ転写むらを防止すること
ができるという効果を奏する。Table [Effects of the Invention] As explained above, according to the present invention, the adhesion force of the toner to the transfer member is extremely small, so that unnecessary images that are wider than the transfer material on the toner carrier can be transferred and The transfer member is not contaminated by transport errors of the transfer material, floating toner, etc., and it is possible to prevent stains on the back side of the transfer material and uneven transfer.
[発明の効果]
以上説明したように本発明によれば、現像剤の転写部材
への付着力が非常に小さくなり、転写部材の現像剤を像
担持体に良好に逆転写させることができ、像担持体上の
被転写材より幅の広い不要画像の転写、被転写材の搬送
ミス、浮遊トナーなどによっても転写部材が汚染される
ことかなく、被転写材の裏汚れ転写むらを防止すること
ができるという効果を奏する。[Effects of the Invention] As explained above, according to the present invention, the adhesion force of the developer to the transfer member is extremely small, and the developer on the transfer member can be successfully reversely transferred to the image carrier. The transfer member is not contaminated by unnecessary images that are wider than the transfer material on the image carrier, transport errors of the transfer material, floating toner, etc., and uneven transfer due to dirt on the back of the transfer material is prevented. It has the effect of being able to
図面は本発明の一実施例を示すもので、第1図は転写ロ
ーラを示す側断面図、第2図は転写ローラの変形例を示
す側断面図、第3図はトナーの転写状態を示す説明図、
第4図(a)は電極構成体の変形例を示す転写ローラの
側断面図、第4図(b)はその側面図、第5図はトナー
転写装置における転写圧力と転写特性゛の関係を示すグ
ラフ図、第6図は転写ローラの抵抗性層の体積抵抗値と
転写特性の関係を示すグラフ図、第7図はトナー転写装
置を組込んだ電子写真装置の概略説明図、第8図(a)
は転写ローラに付着したトナーを除去する第1の方法を
示す説明図、第8図(b)は転写ローラに付着したトナ
ーを除去する第2の方法を示す説明図である。
9.28・・・用紙(被転写材)、5・・・転写ローラ
(転写部材)、21・・・像担持体(感光体)。
出願人代理人 弁理士 鈴江武彦
転マ圧力 (97αηつ
第5ffl
林種穫抗儂(Ω・cm)
第6図
第1 図
第2図
第3図
(a)
1″″
(b)
第4図The drawings show one embodiment of the present invention; FIG. 1 is a side sectional view showing a transfer roller, FIG. 2 is a side sectional view showing a modified example of the transfer roller, and FIG. 3 is a side sectional view showing a toner transfer state. Explanatory diagram,
FIG. 4(a) is a side cross-sectional view of a transfer roller showing a modified example of the electrode structure, FIG. 4(b) is a side view thereof, and FIG. 5 shows the relationship between transfer pressure and transfer characteristics in a toner transfer device. 6 is a graph showing the relationship between the volume resistance value of the resistive layer of the transfer roller and the transfer characteristics. FIG. 7 is a schematic explanatory diagram of an electrophotographic apparatus incorporating a toner transfer device, and FIG. (a)
8(b) is an explanatory view showing a first method of removing toner adhering to the transfer roller, and FIG. 8(b) is an explanatory view showing a second method of removing toner adhering to the transfer roller. 9.28... Paper (transfer material), 5... Transfer roller (transfer member), 21... Image carrier (photoreceptor). Applicant's agent Takehiko Suzue, patent attorney
Claims (1)
れた転写部材とを具備し、前記像担持体と転写部材との
間に被転写材を送り込んで前記現像剤像を転写させ、転
写後、前記転写部材に残った現像剤を前記像担持体に逆
転写させる画像転写装置において、前記転写部材はその
表面層の臨界表面張力をr_R、現像剤の臨界表面張力
をr_Tとしたとき、 |r_R−r_T|≧5[dyne・cm^−^1]の
関係を有することを特徴とする画像転写装置。[Scope of Claims] An image carrier that carries a developer image, and a transfer member that is pressed against the image carrier, and a transfer material is fed between the image carrier and the transfer member to In an image transfer device that transfers a developer image and reversely transfers the developer remaining on the transfer member to the image carrier after the transfer, the transfer member has a critical surface tension of its surface layer r_R, and a critical surface tension of the developer. An image transfer device characterized by having a relationship of |r_R-r_T|≧5 [dyne·cm^-^1], where surface tension is r_T.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP12752289A JPH02306278A (en) | 1989-05-20 | 1989-05-20 | Image transfer device |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP12752289A JPH02306278A (en) | 1989-05-20 | 1989-05-20 | Image transfer device |
Publications (1)
Publication Number | Publication Date |
---|---|
JPH02306278A true JPH02306278A (en) | 1990-12-19 |
Family
ID=14962100
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
JP12752289A Pending JPH02306278A (en) | 1989-05-20 | 1989-05-20 | Image transfer device |
Country Status (1)
Country | Link |
---|---|
JP (1) | JPH02306278A (en) |
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US5418605A (en) * | 1992-12-10 | 1995-05-23 | Canon Kabushiki Kaisha | Charging device and image forming apparatus |
Citations (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPS54114248A (en) * | 1978-02-27 | 1979-09-06 | Olympus Optical Co Ltd | Electrophotographic apparatus |
JPS5890669A (en) * | 1981-11-26 | 1983-05-30 | Olympus Optical Co Ltd | Toner image transfer roll |
JPS6356674A (en) * | 1986-08-27 | 1988-03-11 | Fuji Xerox Co Ltd | Cleaning method for transfer device |
JPS646988A (en) * | 1987-06-30 | 1989-01-11 | Toshiba Corp | Toner transfer device |
-
1989
- 1989-05-20 JP JP12752289A patent/JPH02306278A/en active Pending
Patent Citations (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPS54114248A (en) * | 1978-02-27 | 1979-09-06 | Olympus Optical Co Ltd | Electrophotographic apparatus |
JPS5890669A (en) * | 1981-11-26 | 1983-05-30 | Olympus Optical Co Ltd | Toner image transfer roll |
JPS6356674A (en) * | 1986-08-27 | 1988-03-11 | Fuji Xerox Co Ltd | Cleaning method for transfer device |
JPS646988A (en) * | 1987-06-30 | 1989-01-11 | Toshiba Corp | Toner transfer device |
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US5418605A (en) * | 1992-12-10 | 1995-05-23 | Canon Kabushiki Kaisha | Charging device and image forming apparatus |
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