JP2926761B2 - Developing device - Google Patents

Developing device

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Publication number
JP2926761B2
JP2926761B2 JP17951389A JP17951389A JP2926761B2 JP 2926761 B2 JP2926761 B2 JP 2926761B2 JP 17951389 A JP17951389 A JP 17951389A JP 17951389 A JP17951389 A JP 17951389A JP 2926761 B2 JP2926761 B2 JP 2926761B2
Authority
JP
Japan
Prior art keywords
latent image
magnet roller
image carrier
developing device
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 - Lifetime
Application number
JP17951389A
Other languages
Japanese (ja)
Other versions
JPH0344676A (en
Inventor
岳彦 岡村
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Seiko Epson Corp
Original Assignee
Seiko Epson Corp
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Seiko Epson Corp filed Critical Seiko Epson Corp
Priority to JP17951389A priority Critical patent/JP2926761B2/en
Publication of JPH0344676A publication Critical patent/JPH0344676A/en
Application granted granted Critical
Publication of JP2926761B2 publication Critical patent/JP2926761B2/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

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Description

【発明の詳細な説明】 [産業上の利用分野] 本発明は、磁性現像剤により現像を行う現像装置に関
する。
Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a developing device for developing with a magnetic developer.

[従来の技術] 従来の現像装置は磁気ブラシ現像装置として公知のよ
うに、軸方向に複数の磁極を着磁した円筒状のマグネッ
トローラーを内蔵した、回転自在な非磁性の円筒状のス
リーブによって、マグネットローラー7の発生する磁界
に応じて現像剤による磁気ブラシを形成し現像剤を搬送
し、潜像担持体上の静電潜像に応じて現像を行ってい
た。
[Prior Art] A conventional developing device, as is known as a magnetic brush developing device, includes a rotatable non-magnetic cylindrical sleeve having a built-in cylindrical magnet roller in which a plurality of magnetic poles are magnetized in an axial direction. Then, a magnetic brush made of a developer is formed according to the magnetic field generated by the magnet roller 7, the developer is conveyed, and development is performed according to the electrostatic latent image on the latent image carrier.

[発明が解決しようとする課題] しかし前述の従来技術では、現像ニップにおいて現像
の閾値を決定する磁気力(現像阻止力)が緩慢に変化し
ていたため、現像量にむらができ、解像度が位置的なば
らつきを持つという問題点を有していた。また、着磁し
た磁極分布に応じて現像剤搬送体上の現像剤の密度にむ
らができ、現像剤の搬送量が時間的に変化していたた
め、画像濃度にばらつきを生じさせるという問題点を有
していた。
[Problems to be Solved by the Invention] However, in the above-described conventional technology, the magnetic force (development stopping force) that determines the threshold value of the development in the development nip changes slowly, so that the development amount becomes uneven, and the resolution becomes poor. There is a problem that there is a characteristic variation. In addition, the density of the developer on the developer conveyance body varies according to the distribution of the magnetized magnetic poles, and the amount of the developer conveyed changes with time, which causes a problem that the image density varies. Had.

そこで本発明はこのような問題点を解決するものであ
って、その目的とするところは、画像の位置的な濃度む
らのない、安定した現像量の現像装置を提供するところ
にある。更に他の目的は、高解像度の現像装置を提供す
るところにある。
Accordingly, the present invention is to solve such a problem, and an object of the present invention is to provide a developing device having a stable development amount without unevenness in the density of an image position. Still another object is to provide a high resolution developing device.

[課題を解決するための手段] 本発明の請求項1に記載の現像装置は、静電潜像を形
成する潜像担持体と、前記潜像担持体に隣接して配設さ
れた、像形成体である1成分磁性現像剤を磁気力によっ
て保持し搬送するマグネットローラーと、前記マグネッ
トローラと前記潜像担持体との間に電圧を印加する現像
バイアス印加手段とから成り、前記マグネットローラ上
の前記1成分磁性現像剤を静電的に前記潜像担持体に付
着させて前記静電潜像を顕像化する現像装置において、
前記潜像担持体の半径と回転数をそれぞれrd、ωdと
し、前記マグネットローラの半径をrd、前記マグネット
ローラーの回転数をωm(但し前記潜像担持体と前記マ
グネットローラが近接している部分で、前記潜像担持体
と同一方向に回転する向きを正とする)とし、前記マグ
ネットローラーの磁極数を2p、現像ニップ幅をdとした
とき、 なる式を満たす様に、前記マグネットローラーの回転数
ωmと磁極数2pを設定してなることを特徴とする。
[Means for Solving the Problems] A developing device according to claim 1 of the present invention includes a latent image carrier for forming an electrostatic latent image, and an image provided adjacent to the latent image carrier. A magnet roller for holding and transporting the one-component magnetic developer as a formed body by a magnetic force; and a developing bias applying means for applying a voltage between the magnet roller and the latent image carrier. A developing device for electrostatically attaching the one-component magnetic developer to the latent image carrier to visualize the electrostatic latent image,
The radius and the rotation speed of the latent image carrier are rd and ωd, respectively, the radius of the magnet roller is rd, and the rotation speed of the magnet roller is ωm (however, a portion where the latent image carrier and the magnet roller are close to each other) When the direction of rotation in the same direction as the latent image carrier is positive), the number of magnetic poles of the magnet roller is 2p, and the developing nip width is d, The rotation speed ωm of the magnet roller and the number of magnetic poles 2p are set so as to satisfy the following expression.

本発明の請求項2に記載の現像装置は、前記現像バイ
アス印加手段により印加される前記電圧が、直流電圧で
あることを特徴とする。
The developing device according to claim 2 of the present invention is characterized in that the voltage applied by the developing bias applying unit is a DC voltage.

[作用] 本発明の上記の構成によれば、マグネットローラーの
回転数ωを速くする、もしくはマグネットローラーの
磁極数2pを多くする事等によって、潜像担持体上の一点
が現像ニップを通過する現像時間内に磁気力が短い周期
で変化を繰り返す事になり、また現像剤の磁気ブラシに
よる粗密が繰り返される事になる。したがって、どの現
像位置に於いても同様の現像力分布、現像剤供給量とな
り、安定した現像量が得られる。また、磁気力も好適化
することによって、マグネットローラーから潜像担持体
へ、潜像担持体からマグネットローラーへという現像剤
の両方向の動きを高周波で繰り返させ、高解像度の現像
装置を提供することができる。
According to the above structure of [Operation] The present invention, passing by, etc. to increase the rotational speed omega m of the magnet roller, or to increase the number of magnetic poles 2p magnet roller, a point on the latent image bearing member a developing nip The magnetic force changes repeatedly in a short cycle within the developing time, and the density of the developer by the magnetic brush is repeated. Therefore, the same developing force distribution and the same amount of developer supply are obtained at any developing position, and a stable developing amount can be obtained. Also, by optimizing the magnetic force, it is possible to provide a high-resolution developing device in which the movement of the developer from the magnet roller to the latent image carrier and from the latent image carrier to the magnet roller in both directions is repeated at high frequency. it can.

以下、実施例により本発明を詳細に説明する。 Hereinafter, the present invention will be described in detail with reference to examples.

[実施例] 第1図は本発明の実施例における現像装置を含む画像
形成装置の断面概観図である。一成分現像法の実施例で
あるので、前記現像剤をトナーと称して説明する。図に
於て、1は潜像担持体であり導電性の支持部2の上に光
導電性を有する感光層3を塗膜したものである。感光層
3を帯電器4により所定の電位になるように帯電させた
後に、レーザー等の光源5から出射した光を回転多面鏡
等(図示せず)を用いて走査し結像光学系6により感光
層3に結像させて電位コントラストを得て潜像担持体1
上に静電潜像を形成する。一方図中12は、現像器であり
像形成体であるトナー11を帯電させかつマグネットロー
ラー7で搬送するものである。円筒状のマグネットロー
ラー7に隣接して、搬送量規制部材で導電性かつ平板状
のブレード10が配設される。トナー11はマグネットロー
ラー7の発する磁束によって保持され、ブレード10で搬
送量が規制され、潜像担持体1とマグネットローラー7
が近接している現像ギャップ部分16に搬送され現像ニッ
プを形成する。現像ギャップ部16でトナー11は静電潜像
及び、現像バイアス印加手段13(導電性の支持部2とマ
グネットローラーとの間に接続されている)による現像
電界に応じて潜像担持体1に現像される。さらに顕像化
された像は転写器14によって記録紙15等に静電適に転写
され、加圧や加熱等の手段により定着され所望の画像を
得るものである。
FIG. 1 is a schematic cross-sectional view of an image forming apparatus including a developing device according to an embodiment of the present invention. Since the embodiment is a one-component developing method, the developer will be described as a toner. In the figure, reference numeral 1 denotes a latent image carrier, which is formed by coating a photoconductive photosensitive layer 3 on a conductive support 2. After the photosensitive layer 3 is charged to a predetermined potential by the charger 4, light emitted from a light source 5 such as a laser is scanned by using a rotating polygon mirror or the like (not shown) and is scanned by the imaging optical system 6. The latent image carrier 1 is formed by forming an image on the photosensitive layer 3 to obtain a potential contrast.
An electrostatic latent image is formed thereon. On the other hand, reference numeral 12 in the figure denotes a developing unit which charges the toner 11 which is an image forming body and conveys the toner 11 by the magnet roller 7. Adjacent to the cylindrical magnet roller 7, a conductive and flat blade 10 is provided as a transport amount regulating member. The toner 11 is held by the magnetic flux generated by the magnet roller 7, the transport amount is regulated by the blade 10, and the latent image carrier 1 and the magnet roller 7
Are conveyed to the developing gap portion 16 which is in the vicinity, and form a developing nip. The toner 11 is applied to the latent image carrier 1 in the developing gap portion 16 in response to the electrostatic latent image and the developing electric field by the developing bias applying means 13 (connected between the conductive support 2 and the magnet roller). Developed. Further, the visualized image is electrostatically transferred onto the recording paper 15 or the like by the transfer unit 14, and is fixed by means such as pressure or heating to obtain a desired image.

第1図において、各部の電位は潜像担持体1の導電性
の支持部2を0[V]とすると、スリーブ9が−400
[V]に設定され、また各部の空隙を潜像担持体1とマ
グネットローラー7との間が0.2[mm]、マグネットロ
ーラー7とブレード10との間が0.15 [mm]に設定され
た場合にコントラストの高く濃度階調性の高いトナー像
を形成することができ、光源5に半導体レーザーを用い
ると高解像で面積階調性に優れたトナー像を形成するこ
とができた。
In FIG. 1, when the potential of each part is set to 0 [V] in the conductive support part 2 of the latent image carrier 1, the sleeve 9 has a potential of -400.
When [V] is set and the gap between each part is set to 0.2 [mm] between the latent image carrier 1 and the magnet roller 7, and 0.15 [mm] between the magnet roller 7 and the blade 10. A toner image having high contrast and high density gradation was able to be formed. When a semiconductor laser was used as the light source 5, a toner image having high resolution and excellent area gradation was able to be formed.

尚、第1図の構成は本発明を限定するものではなく、
また上述の数値も本発明を限定するものでない。
The configuration shown in FIG. 1 does not limit the present invention.
Also, the above numerical values do not limit the present invention.

第2図は第1図に示されるような現像器に於て、マグ
ネットローラーの回転数ωと磁極数2pを変えることに
よって次式のNを変化させ、その時の6[LP/mm]のMTF
を示す図である。
Figure 2 is At a developing device as shown in FIG. 1, by changing the N in the following equation by varying the rotation speed omega m and the magnetic pole number 2p of the magnet rollers, at that time 6 [LP / mm] MTF
FIG.

第2図より明らかなように、6[LP/mm]のMTFで40%
以上、目視で濃度むらが識別できない画像はN>20のと
きに得られる。
As is clear from FIG. 2, the MTF of 6 [LP / mm] is 40%.
As described above, an image in which density unevenness cannot be visually identified is obtained when N> 20.

第3図は本発明の現像器による印字の紙搬送方向位置
に対する光学濃度を示す図である。第1図に示される現
像装置による例と、比較例として従来の現像装置による
例を記しており、本発明による現像装置を構成すること
により濃度むらは非常に小さくすることができる。
FIG. 3 is a diagram showing the optical density with respect to the position in the paper transport direction of printing by the developing device of the present invention. An example using the developing device shown in FIG. 1 and an example using a conventional developing device as a comparative example are described. By configuring the developing device according to the present invention, density unevenness can be made very small.

以下、更に詳細な実施例を示す。 Hereinafter, more detailed examples will be described.

実施例1 第1図に示されるような現像装置で、潜像担持体の半
径と回転数をそれぞれrd=15[mm]、ω=30[rpm]
とし、マグネットローラーの半径と回転数をそれぞれrm
=10[mm]、ω=2000[rpm]とし、磁極数2pを10、
現像ニップ幅をd=5[mm]とした実施例である。本実
施例では、印字した紙面上に於けるマグネットローラー
の回転方向位置による濃度むらは、第3図に示すように
平均の光学濃度の6[%]となっており、従来例に比べ
て極めて低く抑えることができた。さらに、地汚れ等の
画像欠陥もなく、細線の解像度も6[LP/mm]のMTFで72
と良好であった。
Example 1 In a developing device as shown in FIG. 1, the radius and the rotation speed of the latent image carrier were respectively set as r d = 15 [mm] and ω d = 30 [rpm].
And the radius and the rotation speed of the magnet roller are each r m
= 10 [mm], ω m = 2000 and [rpm], the number of magnetic poles 2p 10,
This is an embodiment in which the developing nip width is d = 5 [mm]. In the present embodiment, the density unevenness due to the rotational direction position of the magnet roller on the printed paper surface is 6% of the average optical density as shown in FIG. I was able to keep it low. Furthermore, there are no image defects such as background contamination, and the resolution of fine lines is 72 [MTF] of 6 [LP / mm].
And was good.

実施例2 第1図に示されるような現像装置で、マグネットロー
ラーであるマグネットローラーを外形20[mm]、肉厚2
[mm]、回転数をω=1200[rpm]とし、磁極数2pを1
6とした実施例である。潜像担持体の半径と回転数をそ
れぞれrd=15[mm]、ω=25[rpm]とし、現像ニッ
プ幅をd=5[mm]としてある。本実施例の多極着磁し
た磁石は、サマリウムコバルト系の圧縮成形磁石を用
い、充分な搬送量を得た。本実施例でもマグネットロー
ラーの回転方向位置による濃度むらは極めて低く抑える
ことができた。さらに、高解像度の画像を形成すること
ができた。
Example 2 In a developing device as shown in FIG. 1, a magnet roller serving as a magnet roller had an outer shape of 20 mm and a thickness of 2 mm.
[Mm], the number of rotations is ω m = 1200 [rpm], and the number of magnetic poles 2p is 1
Example 6 The radius and rotation speed of the latent image carrier are set to r d = 15 [mm], ω d = 25 [rpm], and the development nip width is set to d = 5 [mm]. As the multi-pole magnetized magnet of this example, a samarium-cobalt-based compression molded magnet was used, and a sufficient transport amount was obtained. Also in this example, the density unevenness due to the position of the magnet roller in the rotation direction could be suppressed to an extremely low level. Furthermore, a high-resolution image could be formed.

実施例3 第1図に示されるような現像装置で、マグネットロー
ラーであるマグネットローラーを外形20[mm]、肉厚0.
5[mm]、回転数をω=600[rpm]とし、磁極数2pを6
0とした実施例である。他の設定は前記の実施例1と同
じであり、充分な搬送量が得られた。また、濃度むらは
極めて低く抑えることができ、さらに高解像度の画像を
形成することができた。
Example 3 In a developing device as shown in FIG. 1, a magnet roller, which is a magnet roller, was formed with an outer diameter of 20 [mm] and a wall thickness of 0.2 mm.
5 [mm], the rotational speed and ω m = 600 [rpm], the number of magnetic poles 2p 6
This is an example in which 0 is set. The other settings were the same as those in Example 1 above, and a sufficient transport amount was obtained. Further, the density unevenness could be suppressed to an extremely low level, and a higher-resolution image could be formed.

比較例 第1図に示されるような現像装置に於て潜像担持体の
半径と回転数をそれぞれrd=15[mm]、ω=25[rp
m]とし、マグネットローラーの半径をrm=10[mm]、
マグネットローラーの回転数をω=800[rpm]とし、
マグネットローラーの磁極数2pを8、現像ニップ幅をd
=5[mm]とした比較例である。従来の技術による本比
較例の紙搬送方向位置による濃度むらは、第3図に表記
してあるように平均光学濃度の25%と濃度ばらつきが大
きく、また解像度についても6[LP/mm]のMTFで15と非
常に低かった。
Comparative Example In a developing device as shown in FIG. 1, the radius and the rotation speed of the latent image carrier were respectively set as r d = 15 [mm] and ω d = 25 [rp].
m], and the radius of the magnet roller is r m = 10 [mm],
The rotation speed of the magnet roller is ω m = 800 [rpm],
The number of magnetic poles of the magnet roller is 2p and the developing nip width is d.
= 5 [mm] is a comparative example. The density unevenness due to the position in the paper conveyance direction of the comparative example according to the conventional technique has a large density variation of 25% of the average optical density as shown in FIG. 3 and a resolution of 6 [LP / mm]. MTF was very low at 15.

尚、本発明は広く電子写真現像装置として使用するこ
とができ、複写機、プリンター、ファクシミリ、ディス
プレイ等に応用が可能である。
The present invention can be widely used as an electrophotographic developing apparatus, and can be applied to a copying machine, a printer, a facsimile, a display, and the like.

[発明の効果] 以上述べたように本発明の上記の構成によれば、どの
現像位置に於いても同様の現像力分布、現像剤供給量と
なり、画像の位置的な濃度むらのない、安定した現像量
の現像装置を提供する事ができる。また、マグネットロ
ーラーから潜像担持体へ、潜像担持体からマグネットロ
ーラーへという現像剤の両方向の動きを高周波で繰り返
させることによって、高解像度の現像装置を提供するこ
とができる。
[Effects of the Invention] As described above, according to the above-described configuration of the present invention, the same developing force distribution and the same amount of developer supply are obtained at any developing position, and there is no density unevenness in image position and stable. It is possible to provide a developing device having a reduced development amount. Further, a high-resolution developing device can be provided by repeating the movement of the developer in both directions from the magnet roller to the latent image carrier and from the latent image carrier to the magnet roller at high frequency.

【図面の簡単な説明】[Brief description of the drawings]

第1図は本発明の実施例における現像装置を含む画像形
成装置の断面概観図。 第2図は本発明の実施例におけるNに対する6[LP/m
m]のMTFを示す図。 第3図は本発明の現像器による印字の紙搬送方向位置に
対する光学濃度を示す図。 1:潜像担持体 7:マグネットローラー 10:ブレード 11:トナー 13:現像バイアス印加手段
FIG. 1 is a schematic cross-sectional view of an image forming apparatus including a developing device according to an embodiment of the present invention. FIG. 2 shows 6 [LP / m for N in the embodiment of the present invention.
m] is a diagram showing the MTF. FIG. 3 is a diagram showing an optical density with respect to a position in the paper transport direction of printing by the developing device of the present invention. 1: latent image carrier 7: magnet roller 10: blade 11: toner 13: developing bias applying means

Claims (2)

(57)【特許請求の範囲】(57) [Claims] 【請求項1】静電潜像を形成する潜像担持体と、前記潜
像担持体に隣接して配設された、像形成体である1成分
磁性現像剤を磁気力によって保持し搬送するマグネット
ローラーと、前記マズネットローラと前記潜像担持体と
の間に電圧を印加する現像バイアス印加手段とから成
り、前記マグネットローラ上の前記1成分磁性現像剤を
静電的に前記潜像担持体に付着させて前記静電潜像を顕
像化する現像装置において、前記潜像担持体の半径と回
転数をそれぞれrd、ωdとし、前記マグネットローラの
半径をrd、前記マグネットローラーの回転数をωm(但
し前記潜像担持体と前記マグネットローラが近接してい
る部分で、前記潜像担持体と同一方向に回転する向きを
正とする)とし、前記マグネットローラーの磁極数を2
p、現像ニップ幅をdとしたとき、 なる式を満たす様に、前記マグネットローラーの回転数
ωmと磁極数2pを設定してなることを特徴とする現像装
置。
1. A latent image carrier for forming an electrostatic latent image, and a one-component magnetic developer, which is an image forming body, disposed adjacent to the latent image carrier, are held and transported by magnetic force. A magnet roller; and a developing bias applying means for applying a voltage between the masnet roller and the latent image carrier, and electrostatically charges the one-component magnetic developer on the magnet roller with the latent image. In a developing device that adheres to a body to visualize the electrostatic latent image, a radius and a rotation speed of the latent image carrier are rd and ωd, respectively, a radius of the magnet roller is rd, and a rotation speed of the magnet roller. Is ωm (however, the direction of rotation in the same direction as the latent image carrier at the portion where the latent image carrier and the magnet roller are close to each other is positive), and the number of magnetic poles of the magnet roller is 2
p, and the development nip width is d, A developing device characterized in that the rotational speed ωm of the magnet roller and the number of magnetic poles 2p are set so as to satisfy the following expression.
【請求項2】前記現像バイアス印加手段により印加され
る前記電圧が、直流電圧であることを特徴とする請求項
1記載の現像装置。
2. The developing device according to claim 1, wherein said voltage applied by said developing bias applying means is a DC voltage.
JP17951389A 1989-07-12 1989-07-12 Developing device Expired - Lifetime JP2926761B2 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP17951389A JP2926761B2 (en) 1989-07-12 1989-07-12 Developing device

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP17951389A JP2926761B2 (en) 1989-07-12 1989-07-12 Developing device

Publications (2)

Publication Number Publication Date
JPH0344676A JPH0344676A (en) 1991-02-26
JP2926761B2 true JP2926761B2 (en) 1999-07-28

Family

ID=16067107

Family Applications (1)

Application Number Title Priority Date Filing Date
JP17951389A Expired - Lifetime JP2926761B2 (en) 1989-07-12 1989-07-12 Developing device

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* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP5354245B2 (en) * 2007-07-20 2013-11-27 株式会社リコー Electrostatic latent image development method

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JPH0344676A (en) 1991-02-26

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