JPH03256078A - Developing device - Google Patents
Developing deviceInfo
- Publication number
- JPH03256078A JPH03256078A JP2053760A JP5376090A JPH03256078A JP H03256078 A JPH03256078 A JP H03256078A JP 2053760 A JP2053760 A JP 2053760A JP 5376090 A JP5376090 A JP 5376090A JP H03256078 A JPH03256078 A JP H03256078A
- Authority
- JP
- Japan
- Prior art keywords
- developing roller
- developing
- image
- toner
- developing device
- 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
- 238000003825 pressing Methods 0.000 claims abstract description 23
- 230000007547 defect Effects 0.000 abstract description 5
- 230000006866 deterioration Effects 0.000 abstract description 4
- 230000015572 biosynthetic process Effects 0.000 abstract description 2
- 238000000034 method Methods 0.000 description 20
- 108091008695 photoreceptors Proteins 0.000 description 12
- 238000011161 development Methods 0.000 description 10
- 239000002184 metal Substances 0.000 description 9
- 229920001971 elastomer Polymers 0.000 description 8
- 239000000463 material Substances 0.000 description 7
- 239000003973 paint Substances 0.000 description 7
- 239000007787 solid Substances 0.000 description 7
- ZWEHNKRNPOVVGH-UHFFFAOYSA-N 2-Butanone Chemical compound CCC(C)=O ZWEHNKRNPOVVGH-UHFFFAOYSA-N 0.000 description 6
- 238000007598 dipping method Methods 0.000 description 5
- 239000002245 particle Substances 0.000 description 5
- WYURNTSHIVDZCO-UHFFFAOYSA-N Tetrahydrofuran Chemical compound C1CCOC1 WYURNTSHIVDZCO-UHFFFAOYSA-N 0.000 description 4
- 239000003795 chemical substances by application Substances 0.000 description 3
- 230000000694 effects Effects 0.000 description 3
- 230000007774 longterm Effects 0.000 description 3
- 229920002635 polyurethane Polymers 0.000 description 3
- 239000004814 polyurethane Substances 0.000 description 3
- 229910052710 silicon Inorganic materials 0.000 description 3
- 239000010703 silicon Substances 0.000 description 3
- 230000003746 surface roughness Effects 0.000 description 3
- 241000519995 Stachys sylvatica Species 0.000 description 2
- 238000013459 approach Methods 0.000 description 2
- 230000006835 compression Effects 0.000 description 2
- 238000007906 compression Methods 0.000 description 2
- 238000010438 heat treatment Methods 0.000 description 2
- 239000004014 plasticizer Substances 0.000 description 2
- 238000012805 post-processing Methods 0.000 description 2
- 230000008569 process Effects 0.000 description 2
- 239000002904 solvent Substances 0.000 description 2
- 239000007921 spray Substances 0.000 description 2
- YLQBMQCUIZJEEH-UHFFFAOYSA-N tetrahydrofuran Natural products C=1C=COC=1 YLQBMQCUIZJEEH-UHFFFAOYSA-N 0.000 description 2
- 229920002799 BoPET Polymers 0.000 description 1
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 1
- 229920002943 EPDM rubber Polymers 0.000 description 1
- 239000005041 Mylar™ Substances 0.000 description 1
- 239000004433 Thermoplastic polyurethane Substances 0.000 description 1
- 229920006311 Urethane elastomer Polymers 0.000 description 1
- 238000005513 bias potential Methods 0.000 description 1
- 229910052799 carbon Inorganic materials 0.000 description 1
- 239000000969 carrier Substances 0.000 description 1
- 230000008859 change Effects 0.000 description 1
- 230000002950 deficient Effects 0.000 description 1
- 238000007865 diluting Methods 0.000 description 1
- 238000006073 displacement reaction Methods 0.000 description 1
- 238000001035 drying Methods 0.000 description 1
- 239000013013 elastic material Substances 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 238000002474 experimental method Methods 0.000 description 1
- 239000006261 foam material Substances 0.000 description 1
- 230000006872 improvement Effects 0.000 description 1
- 239000000696 magnetic material Substances 0.000 description 1
- 239000000203 mixture Substances 0.000 description 1
- 238000004806 packaging method and process Methods 0.000 description 1
- 230000002093 peripheral effect Effects 0.000 description 1
- 238000005498 polishing Methods 0.000 description 1
- 229920001296 polysiloxane Polymers 0.000 description 1
- 229920005749 polyurethane resin Polymers 0.000 description 1
- 239000010734 process oil Substances 0.000 description 1
- 230000001681 protective effect Effects 0.000 description 1
- 238000011084 recovery Methods 0.000 description 1
- 230000009467 reduction Effects 0.000 description 1
- 230000001105 regulatory effect Effects 0.000 description 1
- 229920006395 saturated elastomer Polymers 0.000 description 1
- 239000003566 sealing material Substances 0.000 description 1
- 125000006850 spacer group Chemical group 0.000 description 1
- 238000005507 spraying Methods 0.000 description 1
- 229910001220 stainless steel Inorganic materials 0.000 description 1
- 239000010935 stainless steel Substances 0.000 description 1
- 238000003756 stirring Methods 0.000 description 1
- 229920002803 thermoplastic polyurethane Polymers 0.000 description 1
- 238000012546 transfer Methods 0.000 description 1
Landscapes
- Dry Development In Electrophotography (AREA)
Abstract
Description
【発明の詳細な説明】
［発明の目的コ
（産業上の利用目的）
この発明は、電子写真記録方式や静電記録方式による画
像形成装置の現像装置の改良に関し、さらに詳しくは一
威分現象剤を使用し、加圧現像法によって高品位の画像
を得ることができる現像装置に関する。[Detailed Description of the Invention] [Purpose of the Invention (Industrial Application Purpose) The present invention relates to an improvement of a developing device of an image forming apparatus using an electrophotographic recording method or an electrostatic recording method, and more particularly, to improving a developing device of an image forming apparatus using an electrophotographic recording method or an electrostatic recording method. The present invention relates to a developing device that can obtain high-quality images using a pressure developing method using a developing agent.
（従来の技術）
一成分現象剤を用いる現像方法の一つとして、加圧現像
法（Ｉｍｐｒｅｓｓｉｏｎ Ｄｅｖｅｌｏｐｍｅｎｔ）
が知られている。この方法は静電潜像とトナー粒子もし
くはトナー担持体とを実質的に零の相対周辺速度で接触
させることを特徴としており、磁性材料が不用であるた
め装置の簡素化および小型化が可能であるとともに、ト
ナーのカラー化が容易である等多くの利点を有している
。この加圧現像法においてはトナー保持体を静電潜像に
押圧もしくは接触させて現像を行うために適当な弾性と
トナーに適当な電荷を与えるため導電性を有する現像ロ
ーラを用いる必要がある。特に静電潜像保持体が剛体で
ある場合はこれを傷つけるのを避けるため現像ローラを
弾性体で構成することが必須条件となる。(Prior Art) One of the developing methods using a one-component developing agent is the impression development method.
It has been known. This method is characterized by bringing the electrostatic latent image into contact with toner particles or toner carriers at substantially zero relative peripheral velocity, and since no magnetic material is required, the device can be simplified and miniaturized. It also has many advantages, such as the ease of colorizing the toner. In this pressure development method, it is necessary to use a developing roller having appropriate elasticity and conductivity to impart an appropriate charge to the toner in order to perform development by pressing or contacting the toner holder with the electrostatic latent image. Particularly when the electrostatic latent image holder is a rigid body, it is essential that the developing roller be made of an elastic body to avoid damaging it.
また周知の現像電極効果やバイアス効果を得るためには
現像ローラ表面もしくは表面近傍に導電層を設け、必要
に応じてバイアス電圧を印加することか望ましい。Further, in order to obtain the well-known developing electrode effect and bias effect, it is desirable to provide a conductive layer on or near the surface of the developing roller and apply a bias voltage as necessary.
現像ローラを弾性体で構成した場合、現像ローラとトナ
ー層形成手段および現像ローラと感光体ドラムとの接触
する箇所において、現像ローラに歪が生じてしまう。特
に感光体ドラム上の静電潜像を現像するための十分な接
触幅、つまりニップ幅を得るためには感光体ドラムに現
像ローラを一淀の圧力で押圧するため大きな歪が生じや
すい。When the developing roller is made of an elastic material, distortion occurs in the developing roller at the locations where the developing roller and the toner layer forming means and the developing roller and the photosensitive drum come into contact. In particular, in order to obtain a sufficient contact width, ie, nip width, for developing the electrostatic latent image on the photoreceptor drum, the developing roller is pressed against the photoreceptor drum with a single pressure, which tends to cause large distortion.
現像ローラ上に歪が残った状態で、感光体ドラム上の静
電潜像を現像すると歪が生じている箇所に、自抜けや濃
度ムラといった画像不良が現われるという不都合な点が
ある。この傾向は感光体ドラムに現像ローラを押しつけ
た状態で放置すると顕著に現れ、またゴム硬度５０°以
下の現像ローラをこの発明は、上述した一成分現像剤に
よる加圧現像法におけるこのような従来技術の不都合な
点を解決すべくなされたもので、濃度ムラ等の不良画像
のない高品位の画像が得られ、かつ長期間使用しても画
質に劣化を生じない現像装置を提供しようとするもので
ある。If an electrostatic latent image is developed on a photoreceptor drum with distortion remaining on the developing roller, there is a disadvantage that image defects such as voids and density unevenness will appear in the areas where distortion occurs. This tendency becomes noticeable when the developing roller is left pressed against the photoreceptor drum, and the present invention uses a developing roller with a rubber hardness of 50° or less. This was developed to solve the disadvantages of technology, and aims to provide a developing device that can produce high-quality images without defective images such as density unevenness, and that does not cause deterioration in image quality even after long-term use. It is something.
［発明の構成］
（課題を解決するための手段）
以上の課題を解決するために、この発明は、静電潜像保
持体に対向配置され当該静電潜像保持体表面に一定の押
圧力を与えるように配設されたー弾性を有する現像ロー
ラと、この現像ローラの表面にトナー層を形成するトナ
ー層形成手段とを備え、前記現像ローラ表面のトナー層
を前記静電潜像保持体に接触させることにより静電潜像
保持体上の静電潜像を顕像化する現像装置において、前
記静電潜像保持体表面に対する現像ローラの押圧力の解
除手段を設けたことを特徴とするものである。[Structure of the Invention] (Means for Solving the Problems) In order to solve the above-mentioned problems, the present invention provides an electrostatic latent image holding body that is arranged opposite to the electrostatic latent image holding body and has a constant pressing force on the surface of the electrostatic latent image holding body. a toner layer forming means for forming a toner layer on the surface of the developing roller, the toner layer on the surface of the developing roller is applied to the electrostatic latent image carrier. A developing device that visualizes an electrostatic latent image on an electrostatic latent image holder by bringing it into contact with the electrostatic latent image holder, characterized in that a means for releasing the pressing force of the developing roller against the surface of the electrostatic latent image holder is provided. It is something to do.
（作用）
以上のように、静電潜像保持体に対向配置され、静電潜
像保持体表面に一定の押圧力を与えるように配設した弾
性を有する現像ローラと、この現像ローラの表面にトナ
ー層を形成するトナー層形成手段とを備え、現像ローラ
表面のトナー層を静電潜像保持体に接触させることによ
り静電潜像保持体上の静電潜像において、
静電潜像保持体に対する現像ローラの押圧力解除手段を
設けるため、現像ローラの押圧力を解除することが可能
となり、画像形成装置を放置する際に静電潜像保持体へ
の現像ローラの押圧力が原洒である歪の発生を防ぐこと
が可能になり、歪が原因である自抜けや濃度ムラといっ
た画像不良が発生せず長期間の使用においても画質の劣
化が生じない安定した画像形成を行うことができる。(Function) As described above, the developing roller having elasticity is arranged to face the electrostatic latent image holder and apply a constant pressing force to the surface of the electrostatic latent image holder, and the surface of this developing roller and a toner layer forming means for forming a toner layer on the surface of the developing roller, and by bringing the toner layer on the surface of the developing roller into contact with the electrostatic latent image carrier, the electrostatic latent image is formed on the electrostatic latent image carrier. Since a means for releasing the pressing force of the developing roller against the holder is provided, it is possible to release the pressing force of the developing roller, and when the image forming apparatus is left unused, the pressing force of the developing roller against the electrostatic latent image holder is released. It is now possible to prevent the occurrence of distortion, and to perform stable image formation without image defects such as image defects and density unevenness caused by distortion, and without deterioration of image quality even after long-term use. I can do it.
（実施例）
以下図面を参照しながらこの発明の実施例について説明
する。(Example) Examples of the present invention will be described below with reference to the drawings.
第１図はこの発明による成る画像形成装置の一実施例で
ある加圧型−成分非磁性現像装置３の縦断面図である。FIG. 1 is a longitudinal sectional view of a pressure-type component nonmagnetic developing device 3, which is an embodiment of the image forming apparatus according to the present invention.
本実施例の現像装置は導電性と弾性とを有する現像ロー
ラ９−の外表面にトナー供給ローラ１１により、非磁性
トナーの薄層を形成し、この非磁性トナー薄層を感光体
２の表面に接触させることにより現像を行うものであり
キャリア、Ｍｇローラ、トナー濃度コントローラ等か不
用であり小型化、低価格化が可能である。In the developing device of this embodiment, a thin layer of non-magnetic toner is formed on the outer surface of a developing roller 9- having conductivity and elasticity by a toner supply roller 11. Developing is performed by bringing the toner into contact with the toner, and a carrier, Mg roller, toner density controller, etc. are unnecessary, and miniaturization and cost reduction are possible.
以下に本実施例の現像装置３による現像プロセスを説明
する。The developing process by the developing device 3 of this embodiment will be described below.
トナー容器１２内の非磁性トナー１３はミキサー１４に
撹拌されつつトナー供給ローラ１１に送られ、トナー供
給ローラ１１により、現像ローラ９にトナーが供給され
たのち、トナー粒子は現像ローラ９表面との摩擦により
帯電し現像ローラ表面に静電的に吸着して搬送される。The non-magnetic toner 13 in the toner container 12 is sent to the toner supply roller 11 while being stirred by the mixer 14. After the toner supply roller 11 supplies the toner to the developing roller 9, the toner particles are mixed with the surface of the developing roller 9. It is charged by friction, electrostatically attracted to the surface of the developing roller, and transported.
その後、ブレードホルダＡ１７、スペーサ１８およびブ
レードホルダＢ１９により保持され、現像ローラ９に当
接されたブレード１０によりトナー搬送量が規制される
と同時に両者との摩擦によりトナーの摩擦帯電が行われ
る。本実施例においては、負帯電の有機感光体ドラム２
を使用した反転現像であるため、トナーには負帯電トナ
ーを用いブレード１０も負帯電を付与しやすい材質を使
用している。また感光体ドラム２の表面電位−５５０ｖ
に対して現像バイアス電位は一２００ｖを保護抵抗を介
して現像ローラ９の金属シャフト（９ａ）に給電され現
像ローラ９は感光体ドラム２と約１．２〜４倍程度の速
度で矢印方向（ｗｉｔｈ）に感光体ドラム２と約１〜４
■謹程度の接触幅（現像ニップ）を有して接触回転して
いる。また、トナー粒子は現像位置でも摩擦帯電される
ため、「かぶり」が少なく極めてシャープな画像が得ら
れる。現像残りトナーは、リカバリーブレード（マイラ
ーフィルム）１５を擦り抜は現像装置内へ戻る。また何
らかの原因で現像ローラ９からトナーが落ちるとマシン
内または転写紙を汚すことになるためトナーと反応して
トナーを溶着させるような可塑剤等の部材１６を下部に
取り付けることにより上記欠点が解消し、しかも現像装
置３が上下が反対に置かれてもトナーが落下しないよう
に構成されている。なお、第１図において２１はブレー
ドホルダＡに取り付けられたバックル板でありブレード
１０真面に取り付けられたモルトブレン等で作られた発
泡材２３と当接されることによりトナーのシールおよび
ブレード１０の振動を押えることができ、良好なトナー
層を現像ローラ９上に形成することかできる。またブレ
ード１０は、ブレードホルダ１７の回転軸１７ａおよび
加圧用の複数の圧縮スプリング２０により現像ローラ９
に押圧される。圧縮スプリング２０はブレード１０の薄
板バネ材のバネ定数よりも低いためブレード１０の当接
部か薯耗してもほとんど加圧力が変化しないため良好な
トナー層を維持できるようになっている。Thereafter, the amount of toner conveyed is regulated by the blade 10 held by the blade holder A 17, the spacer 18, and the blade holder B 19, and brought into contact with the developing roller 9, and at the same time, the toner is triboelectrically charged by friction therebetween. In this embodiment, negatively charged organic photoreceptor drum 2
Since this is reversal development using , the toner is negatively charged toner and the blade 10 is also made of a material that easily imparts negative charge. Also, the surface potential of the photoreceptor drum 2 is -550v.
On the other hand, the developing bias potential is -200V, which is supplied to the metal shaft (9a) of the developing roller 9 through a protective resistor, and the developing roller 9 moves in the direction of the arrow at a speed approximately 1.2 to 4 times that of the photoreceptor drum 2 ( with) photoreceptor drum 2 and about 1 to 4
■It rotates in contact with a reasonable contact width (developing nip). Furthermore, since the toner particles are triboelectrically charged even at the development position, extremely sharp images with little "fogging" can be obtained. The toner remaining after development is scraped off through a recovery blade (Mylar film) 15 and returned to the inside of the developing device. Also, if toner falls from the developing roller 9 for some reason, it will stain the inside of the machine or the transfer paper, so the above drawback can be solved by attaching a member 16 such as a plasticizer to the bottom that reacts with the toner and fuses the toner. Moreover, the toner is constructed so that the toner does not fall even if the developing device 3 is placed upside down. In FIG. 1, reference numeral 21 denotes a buckle plate attached to the blade holder A, which seals the toner and seals the blade 10 by coming into contact with a foam material 23 made of maltbrene or the like attached directly to the blade 10. Vibration can be suppressed and a good toner layer can be formed on the developing roller 9. Further, the blade 10 is connected to the developing roller 9 by the rotating shaft 17a of the blade holder 17 and a plurality of compression springs 20 for applying pressure.
Pressed by Since the compression spring 20 has a spring constant lower than that of the thin plate spring material of the blade 10, the pressing force hardly changes even if the contact portion of the blade 10 wears out, so that a good toner layer can be maintained.
現像装置３の感光体ドラム２への押圧力は、バネ２１に
より与えられている。バネ２１は現像装置３のフレーム
ａとバネ支持部材２２との間の間隙２４に張設されてい
る。このバネ２１のバネ定数やバネの変位量Ｘ嘗、およ
びローラの弾性係数等を選定することにより押圧力を所
定の値となるように調整される。本実施例では押圧力を
２０ｇ１０から４００ｇ／（７）までの範囲で調整が可
能である。またバネ支持部材２２は現像装ｆｌｆ３が組
み込まれるいわゆる電子複写機やレーザビームプリンタ
等のメインスイッチと連動し、メインスイッチがｒＯＦ
ＦＪの状態のときには感光体ドラム２と反対の方向に移
動し、感光体ドラム２に対する現像ローラ９の押圧力を
解除し、押圧力が原因である歪の発生を防ぐように構成
されている。メインスイッチがｒｏＮＪの状態でも、し
ばらく使用されないような時でも、一定時間経過後に押
圧力を解除させるといった操作を行わせることも可能で
ある。The pressing force of the developing device 3 against the photosensitive drum 2 is applied by a spring 21 . The spring 21 is stretched in a gap 24 between the frame a of the developing device 3 and the spring support member 22. By selecting the spring constant of the spring 21, the displacement amount X of the spring, the elastic coefficient of the roller, etc., the pressing force is adjusted to a predetermined value. In this embodiment, the pressing force can be adjusted in the range from 20g10 to 400g/(7). Further, the spring support member 22 is interlocked with a main switch of a so-called electronic copying machine, a laser beam printer, etc. in which the developing device flf3 is incorporated, and the main switch is rOF.
When in the FJ state, the developing roller 9 moves in the opposite direction to the photosensitive drum 2, releases the pressing force of the developing roller 9 against the photosensitive drum 2, and is configured to prevent distortion caused by the pressing force. Even when the main switch is in the roNJ state, even when it will not be used for a while, it is possible to perform an operation such as releasing the pressing force after a certain period of time has elapsed.
第２図は現像ローラ上のゴム硬度と白抜は画像発生の割
合を示したもので、現像ローラと感光体ドラムを押し当
てた状態で一週間放置し、放置後１０枚の画出しを行い
白抜は画像の有無を確認したものである。このグラフか
ら現像ローラがゴム硬度５０”以下の場合白抜は画像が
発生し、３０以下では増加していることがわかる。Figure 2 shows the rubber hardness on the developing roller and the white area indicating the rate of image generation.The developing roller and photoreceptor drum were left pressed against each other for a week, and after being left, 10 images were printed. The blank areas are those that confirm the presence or absence of images. From this graph, it can be seen that when the developing roller has a rubber hardness of 50" or less, an image with white spots occurs, and when the rubber hardness is 30" or less, it increases.
次に、本実施例における現像装置３の主要構成部品であ
る現像ローラの説明を行う。第３図は本発明に用いられ
る現像ローラ９の一実施例の斜視断面図である。Next, the developing roller, which is a main component of the developing device 3 in this embodiment, will be explained. FIG. 3 is a perspective sectional view of one embodiment of the developing roller 9 used in the present invention.
本発明に用いられる現像装置において現像ローラ９に要
求される条件は“導電性と弾性を有する”ということて
あり、これを満足する一番簡単な構成は金属シャフトに
導電性ゴムローラを組合せたものであるが、トナーを現
像ローラ表面に圧接しつつ搬送するために、表面の平滑
性が必要となる。In the developing device used in the present invention, the developing roller 9 is required to have conductivity and elasticity, and the simplest configuration that satisfies these requirements is a combination of a metal shaft and a conductive rubber roller. However, in order to convey the toner while being in pressure contact with the developing roller surface, the surface needs to be smooth.
そのため第２図に示されるように金属シャフト９ａの周
囲に弾性体層９ｂと表面導電層９Ｃの二層鷹成とした。Therefore, as shown in FIG. 2, a two-layer structure consisting of an elastic layer 9b and a surface conductive layer 9C is used around the metal shaft 9a.
弾性体層９ｂを選択する場合、導電性のものとそうでな
いものの２通りか考えられるが、導電層９Ｃにハクリや
キズが生じる場合も考慮して導電性のものの方が望まし
い。また弾性体層９ｂは、前記ブレード１０や感光体ド
ラム２の外表面と圧接されているため梱包時や長時間放
置されることによるＪ ｌ５Ｋ６３０１に示される永久
歪（％）も問題となり、１０％を越えると画像に現像ロ
ーラ周期のムラが生してしまう。そこで弾性体層１０９
ｂの圧縮歪（％）は１０％以下、好ましくは５％以下と
しなければならない。また、ゴム硬度と永久歪（％）と
の関係は一般にゴム硬度が大きいほど永久歪は小さくな
る傾向があるのて材料と相互のバランスか重要となる。When selecting the elastic layer 9b, there are two options: one that is conductive and one that is not, but it is preferable to use one that is conductive in consideration of the possibility that the conductive layer 9C may be peeled off or scratched. Furthermore, since the elastic layer 9b is in pressure contact with the outer surface of the blade 10 and the photoreceptor drum 2, permanent deformation (%) as shown in J15K6301 due to packaging or being left for a long time becomes a problem. If it exceeds this, the developing roller cycle will be uneven in the image. Therefore, the elastic layer 109
The compressive strain (%) of b must be 10% or less, preferably 5% or less. In addition, regarding the relationship between rubber hardness and permanent set (%), the permanent set generally tends to decrease as the rubber hardness increases, so the balance between the materials and each other is important.
以上、弾性体層９ｂに要求される特性を満足するものと
して本実施れでは導電性シリコンを選択したか、他にも
導電性ＥＰＤＭゴムや導電性ウレタンゴムなとも要求さ
れる特性を満足しておりこれらを用いてもよいことはい
うまでもない。導電性シリコンから成る弾性体層９ｂは
、ＪＩＳ規格に６３０１のＡ型硬度針で２８°の硬度を
有し、外径は１８關である。また、導電性シリコンの電
気抵抗値は、上記の弾性ローラを直径６０ＩＩ１１のス
テンレス製ローラと接触幅が２■■になるように平行配
置し、両ローラの金属シャフト間に１００ｖの電位差を
設けた時に観測される電流を測定することにより算出し
た結果３．４Ｘ１０３Ω・（７）であった。また永久歪
はＪ ｌ５Ｋ６３０１に示される測定方法を用いて測定
した結果１．８％であった。導電層９Ｃは直接トナーや
感光体に接触するため可塑剤、加硫剤、プロセスオイル
等のしみだしによりトナーや感光体を汚染されないもの
でなければならない。また、表面の平滑性については３
μｍＲｚ以下が望ましくそれ以上になると表面の凹凸の
模様が画像に現れやすくなる。平滑度３μｍＲｚを実現
するためには弾性体層９ｂに十分膜厚の大きい導電層９
ｃを付けた後、後加工（研磨）により所定の外径、表面
粗さに仕上げるということが考えられるが、コストが高
くなるため後加工なしで実現するためには前記弾性体層
９ｂの表面粗さと導−電層９ｃの膜厚とその塗料の粘度
を最適に選択しなければならない。第４図は弾性体層９
ｂに導電層１０９Ｃをつけるための代表的方法を示した
ものである。第４図（ａ）はスプレーによる塗布方法、
第４図（ｂ）はディッピングによる方法、第４図Ｃはナ
イフェツジによる方法、である。それぞれの方法におけ
る塗料の粘度は
スプレー法くディッピング法≦ナイフェツジ法となり、
前記表面の平滑度３μｍＲｚを実現するために必要な塗
料の膜厚Ｔ（μｍ）は、弾性体層９ｂの表面粗さをＳ（
μｒｌＲｚ）とすればスプレー法においては”ｒａｉｏ
ｘｓ、ディッピング法およびナイフェツジ法においては
Ｔ≧５ＸＳを満足すれば可能となる。As mentioned above, in this embodiment, conductive silicone was selected as a material that satisfies the characteristics required for the elastic layer 9b, or conductive EPDM rubber or conductive urethane rubber that also satisfies the required characteristics. It goes without saying that these may also be used. The elastic layer 9b made of conductive silicon has a hardness of 28° with an A-type hardness needle of 6301 according to the JIS standard, and an outer diameter of 18°. The electrical resistance value of conductive silicon was determined by arranging the above elastic roller in parallel with a stainless steel roller with a diameter of 60II11 so that the contact width was 2■■, and creating a potential difference of 100V between the metal shafts of both rollers. The result calculated by measuring the current observed at the time was 3.4×10 3 Ω·(7). Further, the permanent set was measured using the measuring method shown in J15K6301 and was found to be 1.8%. Since the conductive layer 9C comes into direct contact with the toner and the photoreceptor, it must be able to prevent the toner and the photoreceptor from being contaminated by seepage of plasticizers, vulcanizing agents, process oil, and the like. Also, regarding the surface smoothness, 3
It is desirable that the value be less than μmRz, and if it is more than that, patterns of surface irregularities will easily appear in the image. In order to achieve a smoothness of 3 μmRz, the conductive layer 9 has a sufficiently large thickness on the elastic layer 9b.
It is conceivable to finish the surface to a predetermined outer diameter and surface roughness by post-processing (polishing) after attaching c, but since the cost will be high, the surface of the elastic layer 9b cannot be achieved without post-processing. The roughness, the thickness of the conductive layer 9c, and the viscosity of its paint must be optimally selected. FIG. 4 shows the elastic layer 9
10b shows a typical method for applying a conductive layer 109C. Figure 4(a) shows the spray coating method;
FIG. 4(b) shows a dipping method, and FIG. 4C shows a knife method. The viscosity of the paint in each method is spray method, dipping method ≦ Naifetsu method,
The film thickness T (μm) of the paint necessary to achieve the surface smoothness of 3 μmRz is determined by dividing the surface roughness of the elastic layer 9b by S(
μrlRz), then in the spray method “raio
xs, the dipping method, and the Knifezi method, this is possible if T≧5XS is satisfied.
本実施例では導電層９ｂはポリウレタン樹脂中に導電性
カーボン微粒子を分散することにより１０３Ω０の導電
性を付与したものを採用し、以下の工程により導電性シ
リコンから成る弾性層９ｂ表面に導電性ポリウレタン塗
料を塗布し乾燥後、熱処理を行い形成した。In this embodiment, the conductive layer 9b is made of a polyurethane resin that has a conductivity of 103Ω0 by dispersing conductive carbon particles, and the surface of the elastic layer 9b made of conductive silicon is coated with conductive polyurethane by the following process. After applying the paint and drying, it was formed by heat treatment.
まず、導電性ポリウレタン塗料として日本ミラクトロン
（株）社製の商品名“スパレックスＤＨ２０２３１３°
を用い、これにメチルエチルケトン（ＭＥＫ）とテトラ
ヒドロフラン（ＴＨＦ） を１＝１の割合で混合した希
釈溶剤を等量添加する。First, as a conductive polyurethane paint, the product name "Sparex DH202313°" manufactured by Nippon Miractron Co., Ltd.
An equal amount of a diluting solvent, which is a mixture of methyl ethyl ketone (MEK) and tetrahydrofuran (THF) in a ratio of 1:1, is added thereto.
“スパレックスＤＨ２０Ｚ３１３°は熱可塑性ポリウレ
タンをベースにした溶液タイプの導電性ポリウレタン塗
料である。この希釈された塗料を十分に攪したのち、溶
剤で洗浄した弾性体層９ｂの表面にディッピング法を用
いて塗布を行う。弾性体層９ｂの引き上げ速度は３．５
１■／ｓｅｃとした。“Sparex DH20Z313° is a solution-type conductive polyurethane paint based on thermoplastic polyurethane. After thoroughly stirring this diluted paint, a dipping method is applied to the surface of the elastic layer 9b that has been cleaned with a solvent. The pulling speed of the elastic layer 9b is 3.5.
The speed was set at 1/sec.
塗布後、約３０分間空気中てにて乾燥し、その後１００
℃で２０分間熱処理を施した。この結果、層厚約５０μ
ｍの導電層９ｃが得られた。導電層９ｃの層厚はディッ
ピング法の引き上げ速度を変化させることにより１０μ
ｍ〜１００μｍの範囲まで可能である。After application, dry in the air for about 30 minutes, then apply 100%
Heat treatment was performed at ℃ for 20 minutes. As a result, the layer thickness is approximately 50μ
A conductive layer 9c of m was obtained. The layer thickness of the conductive layer 9c can be adjusted to 10μ by changing the pulling speed of the dipping method.
It is possible to range from m to 100 μm.
以上の工程により現像ローラ９は金属シャフトａと導電
層９ｃの間の抵抗値が５Ｘ１０３Ω・（７）、ローラ上
のゴム硬度がＪＩＳ規格に６３０１のＡ型硬度針で３６
°の硬度を有し、表面粗さが３μｍＲｚのものを得るこ
とができた。また弾性体層９ｂと現像ローラ９の硬度比
は１．２９であった。Through the above steps, the developing roller 9 has a resistance value of 5X103Ω・(7) between the metal shaft a and the conductive layer 9c, and the rubber hardness on the roller is 36 with an A type hardness needle of 6301 according to the JIS standard.
It was possible to obtain a material having a hardness of 100°C and a surface roughness of 3 μmRz. Further, the hardness ratio between the elastic layer 9b and the developing roller 9 was 1.29.
次に、この加圧型−成分非磁性現像装置３を用いて現像
ローラ９のシャフト−表面間の抵抗値による特性の変化
を確認するため、現像バイアス電源と金属シャフト間に
任意の抵抗値を介在させて現像実験を行い、現像ローラ
表面の電位と抵抗値および画像との相関を得た。結果を
第５図に示す。Next, in order to confirm the change in characteristics due to the resistance value between the shaft and surface of the developing roller 9 using this pressurized component non-magnetic developing device 3, an arbitrary resistance value is interposed between the developing bias power supply and the metal shaft. A development experiment was conducted to obtain the correlation between the potential of the developing roller surface, the resistance value, and the image. The results are shown in Figure 5.
なおこのときの現像バイアス電源の電圧は−２゜Ｏｖで
ある。Note that the voltage of the developing bias power supply at this time was -2°Ov.
第５図から明らかなように、抵抗値１０７Ω以上の抵抗
値において、白ベタ画像と黒ベタ画像の現像時では現像
ローラ表面電位は違った値を示し、白ベタ画像では白地
潜像電位に、黒ベタ画像では黒ベタ潜像電位に近づく傾
向を示す。つまり大面積の画像部を有する画像では、画
像部潜像電位と現像ローラ表面電位との電位差が小さく
なり濃度の薄い画像となり、反対に画像部の面積が小さ
い細線画像等の場合、現像ローラ表面電位は白地潜像電
位に近づくため画像部との電位差が大きくなり細線が太
ってしまい、メリハリのない画像となってしまう。As is clear from FIG. 5, at a resistance value of 107Ω or more, the developing roller surface potential shows different values when developing a solid white image and a solid black image, and in the case of a solid white image, the potential of the white background latent image changes. A solid black image shows a tendency to approach the potential of a black solid latent image. In other words, in an image with a large image area, the potential difference between the latent image potential of the image area and the surface potential of the developing roller becomes small, resulting in a low-density image. Since the potential approaches the white background latent image potential, the potential difference with the image area increases, making thin lines thicker and resulting in an image with no sharpness.
このような現像ローラ表面電位の変動は、現像時に上記
抵抗中を流れる電流によって生じる。黒ベタ現像時には
負に帯電したトナー粒子が現像ローラ９から感光体ドラ
ム２へ転移するため、現像ローラ９から現像バイアス電
源に向かう電流が流れる。また、白ベタ現像時には、感
光体ドラム２の表面電荷が現像ローラによって除電され
、現像バイアス電源から現像ローラへ向かう電流が流れ
る。Such fluctuations in the surface potential of the developing roller are caused by current flowing through the resistor during development. During black solid development, negatively charged toner particles are transferred from the developing roller 9 to the photosensitive drum 2, so that a current flows from the developing roller 9 toward the developing bias power source. Further, during white solid development, the surface charge of the photosensitive drum 2 is removed by the developing roller, and a current flows from the developing bias power source to the developing roller.
このような電流は抵抗両端に電位差を生じさせ上記のよ
うな現像ローラ表面電位の変動をもたらすものである。Such a current generates a potential difference across the resistor, causing the above-mentioned fluctuation in the surface potential of the developing roller.
この傾向は、Ｉ Ｘ １０８Ω以上で顕著であった。This tendency was remarkable when IX was 108Ω or more.
すなわち、金属シャフトと表面導電層との間の現実の抵
抗値はＩ Ｘ １０”Ω以下が良好な値であることが確
認された。That is, it was confirmed that the actual resistance value between the metal shaft and the surface conductive layer is I x 10''Ω or less.
第６図は抵抗値による画質の変動を表わしたもので、こ
のグラフから抵抗値はＩ Ｘ １０８Ω以下で画像濃度
１．４．カブリが０．１％以下の画像が得られ、Ｉ Ｘ
１０７Ωで画像濃度が飽和していることがわかる。FIG. 6 shows the variation in image quality depending on the resistance value. From this graph, the resistance value is less than I x 108Ω and the image density is 1.4. An image with a fog of 0.1% or less was obtained, and I
It can be seen that the image density is saturated at 107Ω.
以上のことから、金属シャフトと表面導電層との現実の
抵抗値がＩ Ｘ １０７Ω以下の時に良好な画像が得ら
れることが確認された。From the above, it was confirmed that good images can be obtained when the actual resistance value between the metal shaft and the surface conductive layer is I x 107Ω or less.
［発明の効果］
以上の説明から明らかなように、この発明による現像装
置は現像ローラの押圧力解除手段を設けているため、現
像ローラの押圧力が原因である、白抜けや濃度ムラのな
い高品位の画像が得られ、長期間使用しても画質の劣化
を生じない画像を形成てきる。[Effects of the Invention] As is clear from the above description, since the developing device according to the present invention is provided with a means for releasing the pressing force of the developing roller, it is possible to eliminate white spots and density unevenness caused by the pressing force of the developing roller. High-quality images can be obtained, and images that do not deteriorate in image quality even after long-term use can be formed.
第１図はこの発明による現像装置の一実施例の概略構成
を示す断面図、第２図は現像ローラ硬度と白抜は画像発
生の割合を示すグラフ、第３図は本発明における現像ロ
ーラの一実施例を示す斜視断面図、第４図は本発明にお
ける現像ローラの４重層を形成する方法。第５図は本発
明における現像器の一実施例の現像ローラ表面の電位と
抵抗値および画像の相関を示すグラフ。第６図は本発明
における現像器の一実施例の現像ローラ表面抵抗値と画
像濃度の関係を示すグラフ。
９・・・現像ローラ １０ａ・・・薄板バネ材９ａ
・・・金属シャフト １０ｂ・・・チップ９ｂ・・
・弾性体層 １０ｃ・・・シール材９Ｃ・・・導電
層 ２１・・・バネ材１０・・・ブレード ２
２・・・バネ支持部材第１図FIG. 1 is a sectional view showing a schematic configuration of an embodiment of the developing device according to the present invention, FIG. 2 is a graph showing the hardness of the developing roller and the white area indicates the image generation rate, and FIG. 3 is a graph showing the developing roller hardness according to the present invention. FIG. 4 is a perspective cross-sectional view showing one embodiment, and shows a method for forming a four-layered developing roller according to the present invention. FIG. 5 is a graph showing the correlation between the potential, resistance value, and image on the surface of the developing roller in one embodiment of the developing device according to the present invention. FIG. 6 is a graph showing the relationship between the developing roller surface resistance value and image density in one embodiment of the developing device according to the present invention. 9...Developing roller 10a...Thin plate spring material 9a
...Metal shaft 10b...Tip 9b...
- Elastic layer 10c...Sealing material 9C...Conductive layer 21...Spring material 10...Blade 2
2...Spring support member Fig. 1
Claims (1)
定の押圧力を与えるように配設した弾性を有する現像ロ
ーラと、この現像ローラの表面にトナー層を形成するト
ナー層形成手段とを備え、前記現像ローラ表面のトナー
層を静電潜像保持体に接触させることにより静電潜像保
持体上の静電潜像を顕像化する現像装置において、 前記静電潜像保持体に対する現像ローラの押圧力解除手
段を設けたことを特徴とする現像装置。[Scope of Claims] A developing roller having elasticity, which is arranged to face the electrostatic latent image holder and apply a constant pressing force to the surface of the electrostatic latent image holder, and a toner layer on the surface of the developing roller. and a toner layer forming means for forming an electrostatic latent image on the electrostatic latent image carrier by bringing the toner layer on the surface of the developing roller into contact with the electrostatic latent image carrier. 2. A developing device, further comprising means for releasing the pressing force of the developing roller against the electrostatic latent image holder.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2053760A JPH03256078A (en) | 1990-03-07 | 1990-03-07 | Developing device |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2053760A JPH03256078A (en) | 1990-03-07 | 1990-03-07 | Developing device |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH03256078A true JPH03256078A (en) | 1991-11-14 |
Family
ID=12951776
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP2053760A Pending JPH03256078A (en) | 1990-03-07 | 1990-03-07 | Developing device |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH03256078A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US7761025B2 (en) * | 2006-01-19 | 2010-07-20 | Brother Kogyo Kabushiki Kaisha | Developer cartridge and image forming apparatus |
-
1990
- 1990-03-07 JP JP2053760A patent/JPH03256078A/en active Pending
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US7761025B2 (en) * | 2006-01-19 | 2010-07-20 | Brother Kogyo Kabushiki Kaisha | Developer cartridge and image forming apparatus |
| US8213825B2 (en) | 2006-01-19 | 2012-07-03 | Brother Kogyo Kabushiki Kaisha | Cartridge with urging members |
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