JPH1010867A - Image forming device - Google Patents

Image forming device

Info

Publication number
JPH1010867A
JPH1010867A JP8161810A JP16181096A JPH1010867A JP H1010867 A JPH1010867 A JP H1010867A JP 8161810 A JP8161810 A JP 8161810A JP 16181096 A JP16181096 A JP 16181096A JP H1010867 A JPH1010867 A JP H1010867A
Authority
JP
Japan
Prior art keywords
developing
toner
lower jaw
case
casing
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
Application number
JP8161810A
Other languages
Japanese (ja)
Inventor
Kazuhiko Yuki
和彦 結城
Asami Mae
亜佐美 前
Kentaro Matsumoto
健太郎 松本
Kenji Karashima
賢司 辛島
Manabu Mochizuki
望月  学
Noriyuki Usui
則之 碓井
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.)
Ricoh Co Ltd
Original Assignee
Ricoh Co Ltd
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 Ricoh Co Ltd filed Critical Ricoh Co Ltd
Priority to JP8161810A priority Critical patent/JPH1010867A/en
Publication of JPH1010867A publication Critical patent/JPH1010867A/en
Pending legal-status Critical Current

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Abstract

PROBLEM TO BE SOLVED: To provide an image forming device capable of reducing toner accumulations which occur at the lower-case front end (developing-case lower jaw part) of a developing device, preventing toner from falling onto a transfer part and paper carrying part even in case the toner accumulation occurs, and further reducing the occurrences of abnormal images. SOLUTION: This device is equipped with a casing having an opening opposite the surface of a photoreceptor 1, and the developing device having a developing sleeve 3 arranged in the casing. The angle of the front end C of the part 2a (developing-case lower jaw part below the developing sleeve) of the casing of the developing device, which is opposite the surface of the photoreceptor, is an acute angle (less than 90 degrees). That is, by forming the front end C of the developing-case lower jaw part 2a of the developing device so that it has the acute angle, toner accumulations at the front end can be reduced, and the number of sheets which are passed can be increased for the time required for the toner to fall.

Description

【発明の詳細な説明】DETAILED DESCRIPTION OF THE INVENTION

【0001】[0001]

【発明の属する技術分野】本発明は、静電複写装置、プ
リンタ、ファクシミリ等の電子写真方式を応用した画像
形成装置に関する。
BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming apparatus to which an electrophotographic method is applied, such as an electrostatic copying machine, a printer, and a facsimile.

【0002】[0002]

【従来の技術】電子写真方式の画像形成装置、例えばレ
ーザプリンタや複写機において、現像装置による現像の
際またはその後に感光体ドラムからトナーが落下したり
飛散したりすることがある。このトナー飛散は画像形成
装置の内部を汚染し、機器の信頼性を損なうだけでな
く、画像濃度や画質低下の原因になる。従来、このよう
なトナー飛散の防止対策としては、現像ギャップ、現
像ローラとドクターブレード間ギャップ、現像ローラと
現像下ケース間ギャップ等の寸法関係の管理、現像装
置の現像ローラの中心を感光体ドラムの中心を通る水平
線より下方に設ける、また現像装置内に空気孔を設
け、現像ローラと下ケースの隙間の気流を吸い込みにす
る、等の方法により飛散トナーの発生を軽減してきた
(特開平4−248579号公報等参照)。
2. Description of the Related Art In an electrophotographic image forming apparatus such as a laser printer or a copying machine, toner may fall or scatter from a photosensitive drum during or after development by a developing device. The scattering of toner contaminates the inside of the image forming apparatus, not only deteriorating the reliability of the device, but also causing a reduction in image density and image quality. Conventionally, as measures to prevent such toner scattering, management of dimensional relations such as a developing gap, a gap between a developing roller and a doctor blade, a gap between a developing roller and a developing case, and the center of a developing roller of a developing device have been described. (See, for example, Japanese Patent Application Laid-Open No. HEI 4 (1994) -209605), for example, by providing an air hole in the developing device below a horizontal line passing through the center of the developing roller and sucking in the air flow in the gap between the developing roller and the lower case. -248579).

【0003】[0003]

【発明が解決しようとする課題】しかし、上記〜で
は、通紙枚数に対する飛散トナー量は減るが、どうして
も現像装置のケーシングの下ケース先端(現像ケース下
アゴ部と呼ぶ)にトナーが溜まってしまう。特に小粒径
トナーを使用する場合は程度が悪くなる。そして、溜ま
ったトナーは現像スリーブ等が駆動したときに起こる振
動や、現像スリーブと感光体ドラムの回転による風流に
より現像ケース下アゴ先端から転写チャージャや転写入
口マイラーや転写紙に落ち、部分的な転写不良や裏汚れ
等の異常画像が発生した。
However, in the above (1), the amount of scattered toner with respect to the number of sheets passed is reduced, but the toner always accumulates at the tip of the lower case (referred to as the lower jaw portion of the developing case) of the casing of the developing device. . In particular, when a small particle size toner is used, the degree becomes worse. The accumulated toner falls on the transfer charger, the transfer entrance mylar, and the transfer paper from the tip of the lower jaw of the developing case due to vibration generated when the developing sleeve or the like is driven, or the wind current caused by the rotation of the developing sleeve and the photosensitive drum, and the toner is partially removed. Abnormal images such as transfer failure and back stains occurred.

【0004】本発明は上記事情に鑑みなされたものであ
って、現像装置の下ケース先端(現像ケース下アゴ部)
にできるトナー溜まりを減らし、トナー溜まりが起こっ
たときも、トナーを転写部、紙搬送部に落とすことな
く、異常画像の発生をさらに減少できる画像形成装置を
提供することを目的(課題)とする。
The present invention has been made in view of the above circumstances, and is directed to a lower case tip of a developing device (a lower jaw portion of a developing case).
It is an object (problem) to provide an image forming apparatus capable of further reducing occurrence of an abnormal image without dropping toner to a transfer unit and a paper conveyance unit even when toner accumulation occurs, by reducing toner accumulation that can occur. .

【0005】[0005]

【課題を解決するための手段】上記目的を達成するた
め、本発明は、感光体表面に対向する開口を有するケー
シングと、該ケーシング内に配置された現像スリーブを
有する現像装置を備えた画像形成装置において、前記現
像装置のケーシングの感光体表面に対向する部分(現像
スリーブ下方の現像ケース下アゴ部)の先端が鋭角(9
0度以下)であることを特徴とする(請求項1)。すな
わち、現像装置のケーシングの感光体表面に対向する部
分(現像ケース下アゴ部)の先端を鋭角にすることで、
その先端のトナー溜まりを減らすことができ、トナー落
ちまでの時間、通紙枚数を延ばすことが可能となる。
In order to achieve the above object, the present invention provides an image forming apparatus comprising a casing having an opening facing a surface of a photoreceptor, and a developing device having a developing sleeve arranged in the casing. In the apparatus, the tip of the portion of the casing of the developing device facing the photoreceptor surface (the lower jaw portion of the developing case below the developing sleeve) has an acute angle (9).
(Less than 0 degrees) (claim 1). That is, by making the tip of the portion (the lower jaw portion of the developing case) facing the photoreceptor surface of the casing of the developing device an acute angle,
The accumulation of toner at the leading end can be reduced, and the time until the toner drops and the number of sheets passed can be increased.

【0006】また本発明では、前記現像装置のケーシン
グの感光体表面に対向する部分(現像ケース下アゴ部)
の先端形状において、垂線からの角度が現像スリーブ側
の方が感光体ドラム側より小さいことを特徴とする(請
求項2)。すなわち、現像装置のケーシングの感光体表
面に対向する部分(現像ケース下アゴ部)の先端形状に
おいて、垂線からの角度が現像スリーブ側の方が感光体
ドラム側より小さくすることで、先端にトナーが溜まっ
たときもトナーは現像スリーブ側に落ち現像剤に混ざる
ため、トナー溜まりによるトナー落ちを減らすことが可
能となる。
In the present invention, a portion of the casing of the developing device opposed to the surface of the photoreceptor (a lower jaw portion of the developing case).
Wherein the angle from the perpendicular is closer to the developing sleeve than to the photosensitive drum (claim 2). That is, in the shape of the tip of the portion of the casing of the developing device facing the photoconductor surface (the lower jaw portion of the developing case), the angle from the perpendicular to the developing sleeve side is smaller than that of the photoconductor drum side. Even when the toner accumulates, the toner falls to the developing sleeve side and mixes with the developer, so that it is possible to reduce the toner drop due to the toner accumulation.

【0007】[0007]

【発明の実施の形態】以下、本発明の実施の形態を図示
の実施例に基づいて詳細に説明する。
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention will be described in detail based on illustrated embodiments.

【0008】図1は本発明が実施される画像形成装置の
作像部の概略構成を示す図であり、画像形成装置本体に
対して着脱可能に設けられたマガジンタイプの作像部の
みを示している。図1において、符号1は像担持体であ
る感光体ドラム、2はトナーとキャリアからなる2成分
現像剤により感光体ドラム1上の静電潜像を現像する現
像装置、3は2成分現像剤を担持して回転する現像スリ
ーブとその内部に配置された複数の磁極を有する固定マ
グネットとからなる現像ローラ、4は転写部に配設され
た画像形成装置本体側の転写チャージャ、4aは転写入
口マイラー、5は感光体ドラム1上の残留トナーを除去
するクリーニング装置、6は画像形成装置本体との接続
部、7は現像ローラ(現像スリーブ)3上の現像剤量を
規制するドクターブレード、8,9は現像剤横搬送撹拌
用のスクリュー、10はトナー濃度センサ、11はトナ
ー収納部である。尚、感光体ドラム1を帯電するための
帯電器や、帯電された感光体ドラム1に原稿像を露光す
る露光部(あるいはレーザ光による光書き込み部)、転
写紙を給紙する給紙部等は画像形成装置本体側に設けら
れており、図示を省略している。
FIG. 1 is a view showing a schematic configuration of an image forming section of an image forming apparatus in which the present invention is implemented, and shows only a magazine type image forming section detachably provided to a main body of the image forming apparatus. ing. In FIG. 1, reference numeral 1 denotes a photosensitive drum serving as an image carrier, 2 denotes a developing device for developing an electrostatic latent image on the photosensitive drum 1 with a two-component developer including toner and carrier, and 3 denotes a two-component developer. , A developing roller composed of a developing sleeve that rotates while carrying the image, and a fixed magnet having a plurality of magnetic poles disposed therein, 4 is a transfer charger on the image forming apparatus main body side provided in the transfer section, and 4a is a transfer entrance. Mylar, 5 a cleaning device for removing residual toner on the photosensitive drum 1, 6 a connection portion with the image forming apparatus main body, 7 a doctor blade for regulating the amount of developer on the developing roller (developing sleeve) 3, 8 , 9 are screws for agitating and transporting the developer in the horizontal direction. In addition, a charger for charging the photosensitive drum 1, an exposure unit (or an optical writing unit using laser light) for exposing a document image to the charged photosensitive drum 1, a paper feeding unit for feeding transfer paper, and the like Is provided on the image forming apparatus main body side and is not shown.

【0009】次に図1を用いて作像時の動作を簡単に説
明する。まず、帯電、露光により感光体ドラム1に静電
潜像を形成する。その潜像は、現像装置2の現像ローラ
3に担持された現像剤(磁気ブラシ)のトナーにより現
像され顕像化される。そして、図示されない給紙部から
転写部に搬送された転写紙に転写チャージャ4により転
写電荷が付与されることにより感光体ドラム1上のトナ
ー像が引き付けられ、トナー像が転写紙に転写される。
転写後の転写紙は感光体ドラム1から分離され、図示さ
れない定着装置に搬送されトナー像が定着される。一
方、感光体ドラム1上の未転写トナーはクリーニング装
置5によりクリーニングされる。
Next, the operation at the time of image formation will be briefly described with reference to FIG. First, an electrostatic latent image is formed on the photosensitive drum 1 by charging and exposure. The latent image is developed by toner of a developer (magnetic brush) carried on the developing roller 3 of the developing device 2 and is visualized. The transfer charger 4 applies transfer charges to transfer paper conveyed from a paper supply unit (not shown) to the transfer unit, thereby attracting the toner image on the photosensitive drum 1 and transferring the toner image to the transfer paper. .
The transfer paper after the transfer is separated from the photosensitive drum 1, and is conveyed to a fixing device (not shown) to fix the toner image. On the other hand, the untransferred toner on the photosensitive drum 1 is cleaned by the cleaning device 5.

【0010】ところで、以上のような作像動作を数千、
数万枚と繰り返すと、以下に示すような対策で軽減はす
るが、現像ローラ3と現像装置下ケース先端(現像ケー
ス下アゴ部)2aの間の隙間(図中のA部)にトナーが
どうしても溜まってしまう。対策としては、現像ギャ
ップ、現像ローラとドクターブレード間ギャップ、現像
ローラと現像下ケース間ギャップ等の寸法関係の管理、
現像装置の現像ローラの中心を感光体ドラムの中心を
通る水平線より下方に設ける、また現像装置内に空気
孔を設け、現像ローラと下ケースの隙間の気流を吸い込
みにする、等が一般に知られている。
By the way, thousands of image forming operations as described above are performed.
If it is repeated for several tens of thousands of sheets, the amount of toner is reduced by the following countermeasures, but the toner is filled in the gap (part A in the figure) between the developing roller 3 and the developing device lower case tip (developing case lower jaw part) 2a. It will definitely accumulate. As a countermeasure, management of the dimensional relationship such as the developing gap, the gap between the developing roller and the doctor blade, the gap between the developing roller and the lower case,
It is generally known that the center of the developing roller of the developing device is provided below a horizontal line passing through the center of the photosensitive drum, and that an air hole is provided in the developing device so that the airflow in the gap between the developing roller and the lower case is sucked. ing.

【0011】ここで図2に従来の現像ケース下アゴ部の
形状例を示す。図2において各部のギャップは、感光体
ドラム1と現像ローラ3間の現像ギャップGp:0.4
5〜0.6mm、現像ローラ3とドクターブレード7間
のギャップGd:0.5〜0.6mm、現像ローラ2と
現像ケース下アゴ部2aの先端BとのギャップGc1:
0.6〜1.0mm、現像ローラ3のP2極(主極の次
の極)付近と現像ケース下アゴ部2aとのギャップGc
2:1.0〜1.8mm、感光体ドラム1と現像ケース
下アゴ部2aの先端Bとの間のギャップGdc:0.3
〜0.7mmのように寸法管理されている。
FIG. 2 shows an example of the shape of the lower jaw of the conventional developing case. In FIG. 2, the gap of each part is the developing gap Gp between the photosensitive drum 1 and the developing roller 3: 0.4
5 to 0.6 mm, a gap Gd between the developing roller 3 and the doctor blade 7: 0.5 to 0.6 mm, a gap Gc1 between the developing roller 2 and the tip B of the lower jaw 2a of the developing case.
0.6 to 1.0 mm, the gap Gc between the vicinity of the P2 pole (next pole of the main pole) of the developing roller 3 and the developing case lower jaw 2a
2: 1.0 to 1.8 mm, gap Gdc between the photosensitive drum 1 and the front end B of the developing case lower jaw 2a: 0.3
The size is controlled to be 0.7 mm.

【0012】上記の各部のギャップのうち、Gc1、G
dcは狭ければ狭いほどトナー飛散、トナー落ちが軽減
されるが、Gc1は現像ローラ3上の現像剤が現像ケー
ス下アゴ部2aの先端Bで蹴られて剤落ちしないように
設定し、Gdcは現像ケース下アゴ部2aの先端Bが感
光体ドラム1上のトナーに触らないように設定すること
が重要であり、それらを考慮しなければならない。ま
た、Gc2は内圧や気流(吸い込み、脈動、吹き出し)
に影響があるが、図1の現像装置2のようにスクリュー
8,9を用いた現像剤横搬送撹拌方式では吸い込み気流
ができないため、ここでは現像ケース下アゴ部2aの先
端部Bの形状が重要になってくる。すなわち、図2のB
部のように現像ケース下アゴ部2aの先端が平(180
度)だとトナーが溜まりやすく、ある程度での通紙枚数
でトナーが溜まり、駆動時の振動などで現像ケース下ア
ゴ部2aと感光体ドラム1の隙間を通り下に落ち、転写
紙上や転写入口マイラー等に落ち、異常画像を発生して
しまう。
[0012] Of the gaps of the above parts, Gc1, Gc
Gc1 is set so that the developer on the developing roller 3 is prevented from being kicked by the tip B of the lower jaw portion 2a of the developing case, and Gdc1 is set smaller. It is important that the tip B of the lower jaw portion 2a of the developing case does not touch the toner on the photosensitive drum 1, and these factors must be taken into consideration. Gc2 is the internal pressure and airflow (suction, pulsation, blowing)
However, since the suction airflow cannot be performed in the lateral developer stirring method using the screws 8 and 9 as in the developing device 2 of FIG. 1, the shape of the front end portion B of the lower jaw portion 2a of the developing case is changed here. It becomes important. That is, B in FIG.
The tip of the developing case lower jaw 2a is flat (180
), The toner easily accumulates, the toner accumulates with a certain number of sheets passed, falls down through the gap between the developing case lower jaw portion 2a and the photosensitive drum 1 due to vibrations during driving, etc., onto the transfer paper and the transfer entrance. It falls on mylar, etc., and generates an abnormal image.

【0013】そこで本発明は、現像装置2の現像ケース
下アゴ部2aにできるトナー溜まりを減らし、トナー溜
まりが起こったときも、転写部、紙搬送部に落とすこと
なく、異常画像の発生をさらに減少できる構成を提供す
るものである。
Therefore, the present invention reduces the toner accumulation in the lower jaw portion 2a of the developing case of the developing device 2 and further reduces the occurrence of an abnormal image even when the toner accumulation occurs, without dropping it to the transfer section and the paper transport section. This provides a configuration that can be reduced.

【0014】以下、本発明の実施例について説明する。
図3〜5は請求項1の実施例の説明図である。図3に示
すように、本発明では、現像ケース下アゴ部2aの先端
部Cの角度θが鋭角(90度以下)になっており、トナ
ーが溜まらないようになっている。ここで、図8に現像
ケース下アゴ部先端角度θとトナー落ちの関係を示す
が、図8に示すように、現像ケース下アゴ部2aの先端
Cの角度θが小さければ小さいほどトナーが溜まりにく
く、トナー落ちは少なくなる。しかし、現像装置2の下
ケースが樹脂でできているときは、図4のD部のように
どうしても先端が丸くなってしまう。このような場合
は、その丸くなった部分の幅(図4のD部の幅)Wが小
さければ小さいほどトナーが溜まりにくい。例えば図5
のF部のように、現像ケース下アゴ部2aの先端にマイ
ラー12を取り付けた場合、そのマイラー1枚分の幅
0.2mm以下から効果が現われやすい。尚、現像ケー
ス下アゴ部先端幅Wとトナー落ちの関係を図9に示す。
Hereinafter, embodiments of the present invention will be described.
3 to 5 are explanatory diagrams of the first embodiment. As shown in FIG. 3, in the present invention, the angle θ of the tip C of the lower jaw 2a of the developing case is an acute angle (90 degrees or less), so that the toner does not accumulate. Here, FIG. 8 shows the relationship between the developing case lower jaw tip angle θ and the toner drop. As shown in FIG. 8, the smaller the angle θ of the developing case lower jaw 2a tip C, the more the toner accumulates. It is difficult to remove toner. However, when the lower case of the developing device 2 is made of resin, the tip is inevitably rounded as shown by a portion D in FIG. In such a case, the smaller the width W of the rounded portion (the width of the portion D in FIG. 4), the harder the toner accumulates. For example, FIG.
When the mylar 12 is attached to the tip of the lower jaw portion 2a of the developing case as in the portion F of FIG. FIG. 9 shows the relationship between the width W of the tip of the lower jaw portion of the developing case and the amount of toner drop.

【0015】以上のことから、現像ケース下アゴ部2a
の先端の角度θは90度以下の鋭角とし、その先端幅W
を0.2mm以下にすることで、現像ケース下アゴ部2
a先端でのトナー溜まりを減らし、トナー落ちまでの時
間や通紙枚数を従来よりも大幅に延ばすことができる。
From the above, the developing case lower jaw 2a
Is an acute angle of 90 degrees or less, and its tip width W
Is set to 0.2 mm or less, so that the jaw portion 2
(a) The amount of accumulated toner at the leading end can be reduced, and the time until the toner drops and the number of sheets passed can be greatly extended as compared with the related art.

【0016】次に、図6,7は請求項2の実施例の説明
図である。請求項1のように現像ケース下アゴ部2aの
先端を鋭角にして尖らしたとしても僅かにトナー溜まり
ができることがある。そのときトナーが現像ローラ(現
像スリーブ)3側に落ちるか、感光体ドラム1側に落ち
るかを決めるのは、現像ケース下アゴ部2aの先端部を
垂線で分割したときのその垂線からの角度であり、感光
体ドラム側の角度θαと現像スリーブ側の角度θβの関
係で決まる。ここで、現像ケース下アゴ部2aの先端に
僅かにトナー溜まりが生じた場合、図6に示すようにθ
α>θβだとトナーは現像スリーブ側に落ちるため、現
像剤と混ざり問題はないが、逆に図7に示すようにθα
<θβだとトナーは感光体ドラム側に落ち、転写紙や転
写入口マイラー等に落ち異常画像が発生しやすくなる。
尚、θα/θβに対するトナー落ちの関係を図10に示
す。
FIGS. 6 and 7 are explanatory diagrams of the second embodiment. Even if the tip of the lower jaw portion 2a of the developing case is sharpened at an acute angle as described above, toner accumulation may occur slightly. At this time, whether the toner falls to the developing roller (developing sleeve) 3 side or the photosensitive drum 1 side is determined by the angle from the perpendicular when the tip of the lower jaw portion 2a of the developing case is divided by the perpendicular. And is determined by the relationship between the angle θα on the photosensitive drum side and the angle θβ on the developing sleeve side. Here, when a small amount of toner accumulates at the tip of the developing case lower jaw 2a, as shown in FIG.
If α> θβ, the toner falls to the developing sleeve side, so there is no problem of mixing with the developer, but conversely, as shown in FIG.
If <ββ, the toner falls to the photosensitive drum side and falls on transfer paper, transfer entrance mylar, or the like, and an abnormal image is easily generated.
FIG. 10 shows the relationship between the toner drop and θα / θβ.

【0017】以上のように、現像ケース下アゴ部2aの
先端形状において、垂線からの角度は現像スリーブ側の
方の角度θβが感光体ドラム側の角度θαより小さくす
ることで、現像ケース下アゴ部2aの先端にトナーが溜
まったときもスリーブ側に落ち現像剤に混ざるため、ト
ナー溜まりによるトナー落ちを減らすことができる。
As described above, in the shape of the tip of the lower jaw portion 2a of the developing case, the angle from the perpendicular is such that the angle θβ on the developing sleeve side is smaller than the angle θα on the photosensitive drum side. Even when the toner accumulates at the tip of the portion 2a, the toner drops to the sleeve side and mixes with the developer, so that the toner drop due to the toner accumulation can be reduced.

【0018】[0018]

【発明の効果】以上説明したように、請求項1記載の画
像形成装置では、現像装置のケーシングの感光体表面に
対向する部分(現像ケース下アゴ部)の先端を鋭角にす
ることで、その先端のトナー溜まりを減らすことがで
き、トナー落ちまでの時間、通紙枚数を延ばすことがで
き、異常画像の発生をさらに減少することができる。ま
た本発明は特に、現像剤横搬送撹拌方式において現像ス
リーブと下アゴ部の間の隙間に吸い込み気流ができない
ため効果が大きい。
As described above, in the image forming apparatus according to the first aspect, the tip of the portion (the lower jaw portion of the developing case) of the casing of the developing device that faces the surface of the photoreceptor is formed at an acute angle. The accumulation of toner at the leading end can be reduced, the time until the toner drops, the number of sheets passed, and the occurrence of abnormal images can be further reduced. Further, the present invention is particularly effective in the lateral developer agitating method since air cannot be sucked into the gap between the developing sleeve and the lower jaw to allow air flow.

【0019】請求項2記載の画像形成装置では、請求項
1の構成に加え、現像装置のケーシングの感光体表面に
対向する部分(現像ケース下アゴ部)の先端形状におい
て、垂線からの角度が現像スリーブ側の方が感光体ドラ
ム側より小さくすることで、先端にトナーが溜まったと
きもトナーは現像スリーブ側に落ち現像剤に混ざるた
め、トナー溜まりによるトナー落ちを減らすことがで
き、異常画像の発生をさらに減少することができる。ま
た本発明は特に、現像剤横搬送撹拌方式において現像ス
リーブと下アゴ部の間の隙間に吸い込み気流ができない
ため効果が大きい。
According to a second aspect of the present invention, in addition to the configuration of the first aspect, in the tip shape of a portion of the casing of the developing device opposed to the surface of the photoreceptor (the lower jaw portion of the developing case), the angle from the perpendicular is set. By making the developing sleeve side smaller than the photoreceptor drum side, even when toner accumulates at the tip, the toner falls to the developing sleeve side and mixes with the developer, so that toner drop due to toner accumulation can be reduced, and abnormal images Can be further reduced. Further, the present invention is particularly effective in the lateral developer agitating method since air cannot be sucked into the gap between the developing sleeve and the lower jaw to allow air flow.

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

【図1】本発明が実施される画像形成装置の作像部の概
略構成を示す図である。
FIG. 1 is a diagram illustrating a schematic configuration of an image forming unit of an image forming apparatus in which the present invention is implemented.

【図2】従来の現像ケース下アゴ部の形状例を示す図で
ある。
FIG. 2 is a view showing an example of the shape of a conventional lower jaw portion of a developing case.

【図3】請求項1の実施例の説明図であって、現像ケー
ス下アゴ部の形状例を示す図である。
FIG. 3 is an explanatory view of the first embodiment, showing an example of a shape of a lower jaw portion of a developing case;

【図4】請求項1の実施例の説明図であって、現像ケー
ス下アゴ部の形状例を示す図である。
FIG. 4 is an explanatory view of the first embodiment, showing an example of a shape of a lower jaw portion of a developing case;

【図5】請求項1の実施例の説明図であって、現像ケー
ス下アゴ部にマイラーを取り付けた例を示す図である。
FIG. 5 is an explanatory view of the first embodiment, showing an example in which a mylar is attached to a lower jaw portion of the developing case.

【図6】請求項2の実施例の説明図であって、現像ケー
ス下アゴ部の形状例とその現像ケース下アゴ部の先端部
を垂線で分割したときのその垂線からの角度を示す図で
ある。
FIG. 6 is an explanatory view of the embodiment of FIG. 2, showing an example of the shape of the lower jaw portion of the developing case and the angle from the vertical line when the tip of the lower jaw portion of the developing case is divided by the vertical line; It is.

【図7】請求項2の実施例の説明図であって、現像ケー
ス下アゴ部の形状例とその現像ケース下アゴ部の先端部
を垂線で分割したときのその垂線からの角度を示す図で
ある。
FIG. 7 is an explanatory view of the embodiment of FIG. 2, showing an example of the shape of the lower jaw portion of the developing case and the angle from the vertical line when the tip of the lower jaw portion of the developing case is divided by the vertical line; It is.

【図8】現像ケース下アゴ部先端角度とトナー落ちの関
係を示す図である。
FIG. 8 is a diagram illustrating a relationship between a tip angle of a lower jaw portion of a developing case and toner drop.

【図9】現像ケース下アゴ部先端幅とトナー落ちの関係
を示す図である。
FIG. 9 is a diagram showing the relationship between the width of the tip of the lower jaw portion of the developing case and toner drop.

【図10】現像ケース下アゴ部の先端部を垂線で分割し
たときのその垂線からの感光体ドラム側角度(θα)と
現像スリーブ側角度(θβ)の比(θα/θβ)に対す
るトナー落ちの関係を示す図である。
FIG. 10 is a graph showing the toner drop relative to the ratio (θα / θβ) of the photoconductor drum side angle (θα) and the developing sleeve side angle (θβ) from the perpendicular when the tip of the lower jaw portion of the developing case is divided by the perpendicular. It is a figure showing a relation.

【符号の説明】[Explanation of symbols]

1 感光体ドラム 2 現像装置 2a 現像ケース下アゴ部 3 現像ローラ(現像スリーブ) 4 転写チャージャ 4a 転写入口マイラー 5 クリーニング装置 7 ドクターブレード 8,9 現像剤横搬送撹拌用スクリュー 12 マイラー DESCRIPTION OF SYMBOLS 1 Photoreceptor drum 2 Developing device 2a Lower jaw portion of developing case 3 Developing roller (developing sleeve) 4 Transfer charger 4a Transfer entrance mylar 5 Cleaning device 7 Doctor blade 8,9 Screw for horizontal transfer and stirring of developer 12 Mylar

───────────────────────────────────────────────────── フロントページの続き (72)発明者 辛島 賢司 東京都大田区中馬込1丁目3番6号・株式 会社リコー内 (72)発明者 望月 学 東京都大田区中馬込1丁目3番6号・株式 会社リコー内 (72)発明者 碓井 則之 東京都大田区中馬込1丁目3番6号・株式 会社リコー内 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Kenji Karashima 1-3-6 Nakamagome, Ota-ku, Tokyo, Ricoh Co., Ltd. (72) Inventor Manabu Mochizuki 1-3-6 Nakamagome, Ota-ku, Tokyo・ In Ricoh Co., Ltd. (72) Inventor Noriyuki Usui 1-3-6 Nakamagome, Ota-ku, Tokyo ・ In Ricoh Co., Ltd.

Claims (2)

【特許請求の範囲】[Claims] 【請求項1】感光体表面に対向する開口を有するケーシ
ングと、該ケーシング内に配置された現像スリーブを有
する現像装置を備えた画像形成装置において、 前記現像装置のケーシングの感光体表面に対向する部分
(現像スリーブ下方の現像ケース下アゴ部)の先端が鋭
角(90度以下)であることを特徴とする画像形成装
置。
An image forming apparatus comprising: a casing having an opening facing a photoconductor surface; and a developing device having a developing sleeve disposed in the casing, wherein the casing of the developing device faces the photoconductor surface of the casing. An image forming apparatus, wherein a tip of a portion (a lower jaw portion of a developing case below a developing sleeve) has an acute angle (90 degrees or less).
【請求項2】前記現像装置のケーシングの感光体表面に
対向する部分(現像ケース下アゴ部)の先端形状におい
て、垂線からの角度が現像スリーブ側の方が感光体ドラ
ム側より小さいことを特徴とする請求項1記載の画像形
成装置。
2. An image forming apparatus according to claim 1, wherein the shape of the tip of a portion of the casing of the developing device opposed to the surface of the photoreceptor (the lower jaw portion of the developing case) is such that the angle from the perpendicular is closer to the developing sleeve than to the photoconductive drum. The image forming apparatus according to claim 1.
JP8161810A 1996-06-21 1996-06-21 Image forming device Pending JPH1010867A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP8161810A JPH1010867A (en) 1996-06-21 1996-06-21 Image forming device

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP8161810A JPH1010867A (en) 1996-06-21 1996-06-21 Image forming device

Publications (1)

Publication Number Publication Date
JPH1010867A true JPH1010867A (en) 1998-01-16

Family

ID=15742350

Family Applications (1)

Application Number Title Priority Date Filing Date
JP8161810A Pending JPH1010867A (en) 1996-06-21 1996-06-21 Image forming device

Country Status (1)

Country Link
JP (1) JPH1010867A (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2010001471A1 (en) * 2008-07-02 2010-01-07 日本合成化学工業株式会社 Process for producing evoh composite material

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2010001471A1 (en) * 2008-07-02 2010-01-07 日本合成化学工業株式会社 Process for producing evoh composite material
US8722785B2 (en) 2008-07-02 2014-05-13 The Nippon Synthetic Chemical Industry Co., Ltd. Process for producing EVOH composite

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