JP2015096931A5

JP2015096931A5 -

Info

Publication number: JP2015096931A5
Application number: JP2013242378A
Authority: JP
Filing date: 2013-11-22
Publication date: 2017-01-12

Description

以上に説明したものは一例であり、本発明は、次の態様毎に特有の効果を奏する。
（態様Ａ）
トナーＴ等の現像剤を表面上に担持して表面が無端移動し、感光体２等の潜像担持体と対向する現像領域α等の現像領域で潜像担持体の表面の潜像に現像剤を供給して現像する現像ローラ４２等の現像剤担持体と、現像剤担持体の表面に接触して現像領域に向かう現像剤の量を規制するドクタブレード４５等の規制部材とを有し、現像剤担持体の表面に凸部４２ａ及び凹部４２ｂ等の凹凸形状を備える現像装置４等の現像装置において、規制部材に電圧を印加する現像バイアス電源１４２及びツェナーダイオード１４５等の規制部材電圧印加手段を備え、規制部材電圧印加手段は、現像剤担持体から規制部材へ現像剤を向かわせる第一規制電圧と、規制部材から該現像剤担持体へ現像剤を向かわせる第二規制電圧と、を交互に印加する交番電圧を規制部材に印加する。
これによれば、上記実施形態１について説明したように、規制部材に交番電圧を印加することで、凹部内の現像剤が振動し、現像剤担持体の表面に対して繰り返し接触するため、凹部内の現像剤の現像剤担持体表面との摩擦帯電が促進され、弱帯電や逆帯電の現像剤が減少する。よって、弱帯電や逆帯電の現像剤が現像領域に到達することを抑制することが可能となる。
また、凹部内の現像剤が振動することで、規制部材の表面に対しても繰り返し接触する。このため、現像剤の規制部材との摩擦帯電によって弱帯電や逆帯電の現像剤を減少させることができる。この作用によっても弱帯電や逆帯電の現像剤が現像領域に到達することを抑制することが可能となる。
（態様Ｂ）
態様Ａにおいて、現像バイアス電源１４２及びツェナーダイオード１４５等の規制部材電圧印加手段は、ドクタブレード４５等の規制部材と現像ローラ４２等の現像剤担持体との間に存在するトナーＴ等の現像剤の層に放電を生じさせない大きさの電圧を規制部材に印加する。
これによれば、上記実施形態１について説明したように、放電に起因する現像剤の劣化を防止できる。
（態様Ｃ）
態様ＡまたはＢにおいて、凸部４２ａ及び凹部４２ｂ等の凹凸形状の凸部の頂面４２ｔ等の頂面から凹部の底面までの距離が一定である。
これによれば、上記実施形態１について説明したように、現像剤規制部等の規制位置でのトナーＴ等現像剤の振動が現像ローラ４２等の現像剤担持体の場所によらず一定となり、帯電量のばらつきが小さくなる。これにより、画像濃度が安定し、良好な画像を形成することができる。
（態様Ｄ）
態様Ａ乃至Ｃの何れかの態様において、現像ローラ４２等の現像剤担持体は、現像領域α等の現像領域において感光体２等の潜像担持体に対して一定の間隔を持って非接触の状態で対向するように配置される構成であり、現像剤担持体に交番電圧を印加する現像バイアス電源１４２等の現像バイアス印加手段を有する。
これによれば、上記実施形態１について説明したように、現像剤担持体の潜像担持体に対する位置の精度に関わらず、画像欠損を防止することができる。また、現像領域で現像剤のクラウドを形成することで、ドクタブレード４５等の規制部材に印加する電圧の周期に起因する画像濃度のばらつきを抑制できる。
（態様Ｅ）
態様Ｄにおいて、現像バイアス電源１４２及びツェナーダイオード１４５等の規制部材電圧印加手段は、現像バイアス電源１４２等の現像バイアス印加手段が現像ローラ４２等の現像剤担持体に印加する交番電圧を、ツェナーダイオード１４５等の電圧降下手段で電圧降下させ、ドクタブレード４５等の規制部材に印加する交番電圧を生成する。
これによれば、上記実施形態１について説明したように、現像バイアスとして交番電圧を使用した際に、現像剤担持体に印加する電圧を降下させて作り出すため、規制部材に交番電圧を印加する電源を別途設ける構成よりも低コスト化を図ることが出来る。
（態様Ｆ）
態様Ｅにおいて、電圧降下手段がツェナーダイオードである。
これによれば、上記実施形態１について説明したように、現像バイアスとして交番電圧を使用した際に、単純で安価な構成で規制部材に交番電圧を印加することが出来る。
（態様Ｇ）
態様Ａ乃至Ｆの何れかの態様において、第一規制電圧の大きさをＶ１、トナーＴ等の現像剤と現像ローラ４２等の現像剤担持体との平均付着力をＦ１、現像剤の平均帯電量をｑ、現像剤担持体の表面上の凹凸形状の凸部の頂点から凹部の底部までの距離を最大深さｄ、としたときに、ｑ×Ｖ１／ｄ＞Ｆ１の関係を満たす。
これによれば、上記実施形態１について説明したように、凹部の最も深い部分の現像剤も電界により現像剤担持体の表面から離れて振動することが出来る。このため、凹部内の現像剤と現像剤担持体表面との摩擦帯電が促進され、弱帯電や逆帯電の現像剤が減少する効果が向上する。
（態様Ｈ）
態様Ａ乃至Ｇの何れかの態様において、第二規制電圧の大きさをＶ２、トナーＴ等の現像剤とドクタブレード４５等の規制部材との平均付着力をＦ２、現像剤の平均帯電量をｑ、現像剤担持体の表面上の凹凸形状の凸部の頂点から凹部の底部までの距離を最大深さｄ、としたときに、ｑ×Ｖ２／ｄ＞Ｆ２の関係を満たす。
これによれば、上記実施形態１について説明したように、第二規制電圧により規制部材から現像剤が離れるため、規制部材での現像剤の滞留を抑制でき、規制部材へのトナー固着を防止出来る。
（態様Ｉ）
態様Ａ乃至Ｈの何れかの態様において、ドクタブレード４５等の規制部材と現像ローラ４２等の現像剤担持体との接触部である規制ニップにおける現像剤担持体の表面移動方向の長さである規制ニップ幅をａ、現像剤担持体の線速をｖ、交番電圧の周波数をｆ、としたときに、ａ／ｖ＞１／ｆの関係を満たす。
これによれば、上記実施形態１について説明したように、現像剤担持体上に担持されたトナーＴ等の現像剤が、規制ニップを通過する際に、一回以上、規制部材と現像剤担持体との間で振動する構成を実現できる。これにより、周方向等の現像剤担持体の表面移動方向のムラ無く、弱帯電や逆帯電の現像剤が減少する効果を得ることが出来る。
（態様Ｊ）
態様Ａ乃至Ｉの何れかの態様において、第一規制電圧を印加する時間の比率よりも、第二規制電圧を印加する時間の比率の方が高い。
これによれば、上記実施形態１について説明したように、トナーＴ等の現像剤を交番電界で現像ローラ４２等の現像剤担持体とドクタブレード４５等の規制部材との間で振動させる際に、現像剤が規制部材から離れる易くなる。これにより、規制部材に対して現像剤の固着が発生し難くなる。
現像剤担持体から規制部材へ現像剤が向かう電界により、規制部材上で現像剤が滞留しやすくなり、規制部材への現像剤固着が発生し易くなる。これに対して、第一規制電圧Ｖ１等の第一規制電圧の印加時間「ｔ１」を第二規制電圧Ｖ２等の第二規制電圧の印加時間を「ｔ２」より短くすることで、規制部材上での現像剤の滞留時間を短くし、現像剤固着の発生を抑制する。
（態様Ｋ）
請求項Ｊにおいて、現像ローラ４２等の現像剤担持体に印加される現像バイアスＶａ等の電圧は、現像剤担持体から感光体２等の潜像担持体にトナーＴ等の現像剤を向かわせるための第三電圧Ｖ３等の第三電圧と、潜像担持体から現像剤担持体に現像剤を向かわせるための第四電圧Ｖ４等の第四電圧とを備えた交番電圧であり、第一規制電圧Ｖ１等の第一規制電圧の印加時間を「ｔ１」とし、第二規制電圧Ｖ２等の第二規制電圧の印加時間を「ｔ２」として、第三電圧の印加時間を「ｔ３」とし、第四電圧の印加時間を「ｔ４」としたときに、「ｔ３≠ｔ４」の関係であって、「ｔ３＞ｔ４」の場合は、「ｔ１＝ｔ４」、且つ、「ｔ２＝ｔ３」の関係を満たし、「ｔ３＜ｔ４」の場合は、「ｔ１＝ｔ３」、且つ、「ｔ２＝ｔ４」の関係を満たす。
これによれば、上記実施形態１について説明したように、ドクタブレード４５等の規制部材に対する固着の発生を抑制しつつ、低コスト化及び小型化を測ることができる。
（態様Ｌ）
態様Ａ乃至Ｉの何れかの態様において、第二規制電圧を印加する時間の比率よりも、第一規制電圧を印加する時間の比率の方が高い。
これによれば、上記実施形態１について説明したように、トナーＴ等の現像剤を交番電界で現像ローラ４２等の現像剤担持体とドクタブレード４５等の規制部材との間で振動させる際に、現像剤が現像剤担持体から離れる易くなる。これにより、現像剤担持体に対して現像剤のフィルミングが発生し難くなる。
（態様Ｍ）
態様Ａ乃至Ｌの何れかの態様において、当該現像装置の使用環境や上記現像剤担持体の表面移動距離に応じて、上記第一規制電圧を印加する時間と上記第二規制電圧を印加する時間との比率を変化させる。
これによれば、上記実施形態１について説明したように、現像剤の使用環境や現像装置中のトナーＴ等の現像剤の劣化に対して、その課題に応じた時間の比率で第一規制電圧と第二規制電圧とを印加することが出来る。これにより、規制部材に対する現像剤の固着や現像剤担持体に対する現像剤のフィルミングを経時に渡って抑制できる。
（態様Ｎ）
態様Ａ乃至Ｍの何れかの態様において、現像ローラ４２等の現像剤担持体の走行距離等の表面移動距離に応じて、交番電圧の周波数を変化させる。
これによれば、上記実施形態１について説明したように、現像剤や現像剤担持体の経時劣化に起因する帯電量の変動を補正し、経時に渡って適切な帯電量を維持することができ、地汚れの発生を防止できる。
（態様Ｏ）
態様Ａ乃至Ｎの何れかの態様において、現像装置４等の現像装置の使用環境に応じて、交番電圧の周波数を変化させる。
これによれば、上記実施形態１について説明したように、使用環境の変動による帯電量変動を補正し、使用環境が変動しても適切な帯電量を維持することができ、地汚れの発生を防止できる。
（態様Ｐ）
態様Ａ乃至Ｏの何れかの態様において、現像装置４等の現像装置内にトナーＴ等の現像剤が大量に補給された後と、通常時とで交番電圧の周波数を変化させる。
これによれば、上記実施形態１について説明したように、トナーエンドリカバリー動作等の現像剤が大量に補給された後であっても適切な帯電量を維持することができ、地汚れの発生を防止できる。
（態様Ｑ）
態様Ａ乃至Ｐの何れかの態様において、現像ローラ４２等の現像剤担持体に印加される電圧は、現像剤担持体から感光体２等の潜像担持体にトナーＴ等の現像剤を向かわせるための第三電圧Ｖ３等の第三電圧と、潜像担持体から現像剤担持体に現像剤を向かわせるための第四電圧Ｖ４等の第四電圧とを備えた交番電圧であり、ドクタブレード４５等の規制部材に印加される交番電圧の周波数を「ｆ１」とし、現像剤担持体に印加される交番電圧の周波数を「ｆ２」としたとき、「ｆ１≠ｆ２」の関係を満たす。
これによれば、上記実施形態１について説明したように、周期的な電圧の変動に起因する画像の周期ムラの発生を抑制できる。
（態様Ｒ）
少なくとも感光体２等の潜像担持体と、潜像担持体表面を帯電させるための帯電部材３等の帯電手段と、潜像担持体上に静電潜像を形成するための露光装置６等の潜像形成手段と、静電潜像を現像してトナー像化するための現像手段とを有する複写機５００等の画像形成装置において、現像手段として、態様Ａ乃至Ｑの何れか一つの態様の現像装置を用いる。
これによれば、上記実施形態１について説明したように、弱帯電や逆帯電の現像剤が現像領域に起因する地汚れ等の画像不良の発生を抑制することが可能となる。
（態様Ｓ）
潜像を担持する感光体２等の潜像担持体と、潜像担持体上の潜像を現像する現像手段とを備える複写機５００等の画像形成装置における少なくとも潜像担持体と現像手段とを１つのユニットとして共通の保持体に保持させて画像形成装置本体に対して一体的に着脱可能に構成したプロセスカートリッジ１等のプロセスカートリッジにおいて、態様Ａ乃至Ｒの何れか一つの態様の現像装置を用いる。
これによれば、上記実施形態１について説明したように、地汚れ等の画像不良の発生を抑制することが可能な現像装置を、プロセスカートリッジを構成する他の部材ともに装置本体から取り外すことができる。よって、地汚れ等の画像不良の発生を抑制することが可能な現像装置の交換性の向上を図ることができる。
（態様Ｔ）
トナーＴ等の現像剤を表面上に担持して表面が無端移動し、感光体２等の潜像担持体と対向する現像領域α等の現像領域で潜像担持体の表面の潜像に現像剤を供給して現像する現像ローラ４２等の現像剤担持体と、現像剤担持体の表面に接触して現像領域に向かう現像剤の量を規制するドクタブレード４５等の規制部材とを有し、現像剤担持体の表面に凸部４２ａ及び凹部４２ｂ等の凹凸形状を備える現像装置４等の現像装置において、規制部材に電圧を印加する現像バイアス電源１４２及びツェナーダイオード１４５等の規制部材電圧印加手段を備え、規制部材電圧印加手段は、現像剤担持体と規制部材との間で現像剤を移動させる電圧を規制部材に印加する。
これによれば、上記変形例について説明したように、現像剤を現像剤担持体と規制部材との間で動かすことができ、現像剤が摩擦帯電する機会が増える。その結果、弱帯電や逆帯電の現像剤が減少する。よって、弱帯電や逆帯電の現像剤が現像領域に到達することを抑制することが可能となり、地汚れが発生することを抑制できる。
（態様Ｕ）
態様Ｔにおいて、現像バイアス電源１４２及びツェナーダイオード１４５等の規制部材電圧印加手段は、現像ローラ４２等の現像剤担持体からドクタブレード４５等の規制部材に現像剤を向かわせる電圧を規制部材に印加する。
これによれば、上記変形例１について説明したように、現像剤を現像剤担持体側から規制部材側に動かすことができ、現像剤が摩擦帯電する機会が増える。その結果、弱帯電や逆帯電の現像剤が減少する。よって、弱帯電や逆帯電の現像剤が現像領域に到達することを抑制することが可能となり、地汚れが発生することを抑制できる。さらに、現像剤が現像剤担持体から離れて規制部材側に移動するため、現像剤担持体におけるフィルミングが発生し難くなる。
（態様Ｖ）
態様Ｕにおいて、現像バイアス電源１４２及びツェナーダイオード１４５等の規制部材電圧印加手段は、ドクタブレード４５等の規制部材から現像ローラ４２等の現像剤担持体に現像剤を向かわせる電圧を規制部材に印加する。
これによれば、上記変形例２について説明したように、現像剤を規制部材側から現像剤担持体側に動かすことができ、現像剤が摩擦帯電する機会が増える。その結果、弱帯電や逆帯電の現像剤が減少する。よって、弱帯電や逆帯電の現像剤が現像領域に到達することを抑制することが可能となり、地汚れが発生することを抑制できる。さらに、現像剤が規制部材から離れて現像剤担持体側に移動するため、規制部材における現像剤の固着が発生し難くなる。 What has been described above is merely an example, and the present invention has a specific effect for each of the following modes.
(Aspect A)
A developer such as toner T is carried on the surface, the surface moves endlessly, and a latent image on the surface of the latent image carrier is developed in a development area such as a development area α facing the latent image carrier such as the photosensitive member 2. A developer carrier such as a developing roller 42 that supplies the developer and develops; and a regulating member such as a doctor blade 45 that regulates the amount of developer that contacts the surface of the developer carrier and moves toward the development region. In a developing device such as the developing device 4 having a concavo-convex shape such as the convex portion 42a and the concave portion 42b on the surface of the developer carrying member, voltage application of a regulating member such as a developing bias power source 142 and a Zener diode 145 that applies a voltage to the regulating member A regulating member voltage applying means, a first regulating voltage for directing the developer from the developer carrying member to the regulating member, and a second regulating voltage for directing the developer from the regulating member to the developer carrying member, Alternating power And it applies to the regulation member.
According to this, as described in the first embodiment, by applying an alternating voltage to the regulating member, the developer in the recess vibrates and repeatedly contacts the surface of the developer carrier. The frictional charging of the developer with the surface of the developer carrying member is promoted, and weakly charged or reversely charged developer is reduced. Therefore, it is possible to suppress the weakly charged or reversely charged developer from reaching the development region.
Further, the developer in the recesses vibrates and repeatedly contacts the surface of the regulating member. For this reason, weakly charged or reversely charged developer can be reduced by frictional charging with the regulating member of the developer. This action also makes it possible to suppress the weakly charged or reversely charged developer from reaching the development region.
(Aspect B)
In the aspect A, the regulating member voltage application means such as the developing bias power source 142 and the Zener diode 145 is a developer such as toner T existing between the regulating member such as the doctor blade 45 and the developer carrier such as the developing roller 42. A voltage having a magnitude that does not cause discharge in the layer is applied to the regulating member.
According to this, as described in the first embodiment, it is possible to prevent the deterioration of the developer due to the discharge.
(Aspect C)
In the aspect A or B, the distance from the top surface such as the top surface 42t of the convex portion of the concave and convex shape such as the convex portion 42a and the concave portion 42b to the bottom surface of the concave portion is constant.
According to this, as described in the first embodiment, the vibration of the developer such as the toner T at the restriction position such as the developer restriction portion becomes constant regardless of the location of the developer carrier such as the development roller 42, Variation in charge amount is reduced. As a result, the image density is stable and a good image can be formed.
(Aspect D)
In any of the aspects A to C, the developer carrying member such as the developing roller 42 is not in contact with the latent image carrier such as the photosensitive member 2 in the developing region such as the developing region α with a certain distance. And a developing bias applying means such as a developing bias power source 142 for applying an alternating voltage to the developer carrying member.
According to this, as described in the first embodiment, image loss can be prevented regardless of the accuracy of the position of the developer carrier relative to the latent image carrier. Further, by forming a cloud of developer in the development region, it is possible to suppress variations in image density due to the period of the voltage applied to the regulating member such as the doctor blade 45.
(Aspect E)
In the mode D, the regulating member voltage applying means such as the developing bias power supply 142 and the Zener diode 145 includes an alternating voltage that the developing bias applying means such as the developing bias power supply 142 applies to the developer carrier such as the developing roller 42. The voltage is dropped by a voltage drop means such as 145 to generate an alternating voltage to be applied to the regulating member such as the doctor blade 45.
According to this, as described in the first embodiment, when the alternating voltage is used as the developing bias, the voltage applied to the developer carrying member is generated by lowering the voltage so that the alternating voltage is applied to the regulating member. The cost can be reduced as compared with the configuration in which the is provided separately.
(Aspect F)
In the aspect E, the voltage drop means is a Zener diode.
According to this, as described in the first embodiment, when the alternating voltage is used as the developing bias, the alternating voltage can be applied to the regulating member with a simple and inexpensive configuration.
(Aspect G)
In any of the aspects A to F, the magnitude of the first regulation voltage is V1, the average adhesion force between the developer such as the toner T and the developer carrier such as the developing roller 42 is F1, and the average charge of the developer When the amount is q, and the distance from the top of the concavo-convex convex portion on the surface of the developer carrying member to the bottom of the concave portion is the maximum depth d, the relationship of q × V1 / d> F1 is satisfied.
According to this, as described in the first embodiment, the developer at the deepest portion of the recess can also vibrate away from the surface of the developer carrier by the electric field. For this reason, frictional charging between the developer in the recess and the surface of the developer carrying member is promoted, and the effect of reducing the weakly charged or reversely charged developer is improved.
(Aspect H)
In any of the aspects A to G, the magnitude of the second regulation voltage is V2, the average adhesion force between the developer such as the toner T and the regulation member such as the doctor blade 45 is F2, and the average charge amount of the developer is The relationship of q × V2 / d> F2 is satisfied, where q is the maximum depth d, the distance from the top of the concavo-convex convex portion on the surface of the developer carrier to the bottom of the concave portion.
According to this, as described in the first embodiment, since the developer is separated from the regulating member by the second regulating voltage, the retention of the developer on the regulating member can be suppressed, and the toner can be prevented from sticking to the regulating member. .
(Aspect I)
In any of the aspects A to H, the length in the direction of surface movement of the developer carrying member at the regulating nip, which is a contact portion between the regulating member such as the doctor blade 45 and the developer carrying member such as the developing roller 42. When the regulation nip width is a, the linear velocity of the developer carrier is v, and the frequency of the alternating voltage is f, the relationship of a / v> 1 / f is satisfied.
According to this, as described in the first embodiment, when the developer such as the toner T carried on the developer carrying member passes through the regulating nip, the regulating member and the developer carrying are carried once or more. The structure which vibrates between bodies can be realized. Thereby, there can be obtained an effect of reducing weakly charged or reversely charged developer without unevenness in the surface movement direction of the developer carrying member in the circumferential direction or the like.
(Aspect J)
In any of the aspects A to I, the ratio of the time for applying the second regulation voltage is higher than the ratio of the time for applying the first regulation voltage.
According to this, when the developer such as the toner T is vibrated between the developer carrier such as the developing roller 42 and the regulating member such as the doctor blade 45 with an alternating electric field as described in the first embodiment. , It becomes easy for the developer to leave the regulating member. This makes it difficult for the developer to adhere to the regulating member.
Due to the electric field of the developer from the developer carrying member toward the regulating member, the developer tends to stay on the regulating member, and the developer sticks to the regulating member easily. On the other hand, the application time “t1” of the first regulation voltage such as the first regulation voltage V1 is made shorter than the time “t2” of the second regulation voltage such as the second regulation voltage V2. The residence time of the developer at is shortened to suppress the occurrence of developer sticking.
(Aspect K)
In claim J, the voltage such as the developing bias Va applied to the developer carrier such as the developing roller 42 causes the developer such as toner T to be directed from the developer carrier to the latent image carrier such as the photosensitive member 2. An alternating voltage including a third voltage such as a third voltage V3 and a fourth voltage such as a fourth voltage V4 for directing the developer from the latent image carrier to the developer carrier. The application time of the first regulation voltage such as the regulation voltage V1 is “t1”, the application time of the second regulation voltage such as the second regulation voltage V2 is “t2”, the application time of the third voltage is “t3”, When the application time of the fourth voltage is “t4”, the relationship is “t3 ≠ t4”, and when “t3> t4”, the relationship is “t1 = t4” and “t2 = t3” When “t3 <t4” is satisfied, the relationship of “t1 = t3” and “t2 = t4” is satisfied. .
According to this, as described in the first embodiment, it is possible to measure cost reduction and miniaturization while suppressing the occurrence of sticking to the regulating member such as the doctor blade 45.
(Aspect L)
In any of the aspects A to I, the ratio of the time for applying the first regulation voltage is higher than the ratio of the time for applying the second regulation voltage.
According to this, when the developer such as the toner T is vibrated between the developer carrier such as the developing roller 42 and the regulating member such as the doctor blade 45 with an alternating electric field as described in the first embodiment. , It becomes easier for the developer to leave the developer carrier. This makes it difficult for developer filming to occur on the developer carrier.
(Aspect M)
In any one of the aspects A to L, the time for applying the first regulation voltage and the time for applying the second regulation voltage according to the use environment of the developing device and the surface movement distance of the developer carrier. And change the ratio.
According to this, as described in the first embodiment, the first regulated voltage is used at a time ratio corresponding to the problem with respect to the usage environment of the developer and the deterioration of the developer such as the toner T in the developing device. And the second regulation voltage can be applied. Thereby, sticking of the developer to the regulating member and filming of the developer to the developer carrier can be suppressed over time.
(Aspect N)
In any of the aspects A to M, the frequency of the alternating voltage is changed according to the surface movement distance such as the travel distance of the developer carrier such as the developing roller 42.
According to this, as described in the first embodiment, it is possible to correct the variation in the charge amount due to the deterioration with time of the developer and the developer carrying member, and to maintain an appropriate charge amount over time. , Can prevent the occurrence of dirt.
(Aspect O)
In any of the aspects A to N, the frequency of the alternating voltage is changed according to the use environment of the developing device such as the developing device 4.
According to this, as described in the first embodiment, the variation in the charge amount due to the change in the use environment can be corrected, and the appropriate charge amount can be maintained even if the use environment changes, and the occurrence of soiling can be prevented. Can be prevented.
(Aspect P)
In any one of the aspects A to O, the frequency of the alternating voltage is changed after a large amount of developer such as the toner T is replenished in the developing device such as the developing device 4 and in a normal time.
According to this, as described in the first embodiment, an appropriate charge amount can be maintained even after a large amount of developer has been replenished, such as a toner end recovery operation. Can be prevented.
(Aspect Q)
In any one of the aspects A to P, the voltage applied to the developer carrier such as the developing roller 42 is directed from the developer carrier to the latent image carrier such as the photosensitive member 2 toward the developer such as toner T. An alternating voltage comprising a third voltage such as a third voltage V3 for transferring the toner and a fourth voltage such as a fourth voltage V4 for directing the developer from the latent image carrier to the developer carrier. When the frequency of the alternating voltage applied to the regulating member such as the blade 45 is “f1” and the frequency of the alternating voltage applied to the developer carrier is “f2”, the relationship “f1 ≠ f2” is satisfied.
According to this, as described in the first embodiment, it is possible to suppress the occurrence of the periodic unevenness of the image due to the periodic voltage fluctuation.
(Aspect R)
At least a latent image carrier such as the photosensitive member 2, charging means such as a charging member 3 for charging the surface of the latent image carrier, an exposure device 6 for forming an electrostatic latent image on the latent image carrier, and the like. In the image forming apparatus such as the copier 500 having the latent image forming unit and the developing unit for developing the electrostatic latent image into a toner image, any one of modes A to Q is used as the developing unit. The developing device is used.
According to this, as described in the first embodiment, it is possible to suppress the occurrence of image defects such as background stains caused by the weakly charged or reversely charged developer due to the development region.
(Aspect S)
At least a latent image carrier and a developing unit in an image forming apparatus such as a copying machine 500 including a latent image carrier such as the photosensitive member 2 that carries the latent image and a developing unit that develops the latent image on the latent image carrier. A developing device according to any one of aspects A to R in a process cartridge such as the process cartridge 1 that is configured to be held on a common holding body as a unit and detachably integrated with the main body of the image forming apparatus. Is used.
According to this, as described in the first embodiment, the developing device capable of suppressing the occurrence of image defects such as background stains can be removed from the apparatus main body together with the other members constituting the process cartridge. . Therefore, it is possible to improve the exchangeability of the developing device that can suppress the occurrence of image defects such as background stains.
(Aspect T)
A developer such as toner T is carried on the surface, the surface moves endlessly, and a latent image on the surface of the latent image carrier is developed in a development area such as a development area α facing the latent image carrier such as the photosensitive member 2. A developer carrier such as a developing roller 42 that supplies the developer and develops; and a regulating member such as a doctor blade 45 that regulates the amount of developer that contacts the surface of the developer carrier and moves toward the development region. In a developing device such as the developing device 4 having a concavo-convex shape such as the convex portion 42a and the concave portion 42b on the surface of the developer carrying member, voltage application of a regulating member such as a developing bias power source 142 and a Zener diode 145 that applies a voltage to the regulating member The regulating member voltage applying means applies a voltage for moving the developer between the developer carrying member and the regulating member to the regulating member.
According to this, as described in the modified example, the developer can be moved between the developer carrier and the regulating member, and the opportunity for the developer to be frictionally charged increases. As a result, weakly charged or reversely charged developer is reduced. Therefore, it is possible to suppress the weakly charged or reversely charged developer from reaching the developing region, and it is possible to suppress the occurrence of background contamination.
(Aspect U)
In aspect T, the regulating member voltage applying means such as the developing bias power supply 142 and the Zener diode 145 applies a voltage for directing the developer from the developer carrying member such as the developing roller 42 to the regulating member such as the doctor blade 45. To do.
According to this, as described in the first modification, the developer can be moved from the developer carrying member side to the regulating member side, and the opportunity for the developer to be frictionally charged increases. As a result, weakly charged or reversely charged developer is reduced. Therefore, it is possible to suppress the weakly charged or reversely charged developer from reaching the developing region, and it is possible to suppress the occurrence of background contamination. Furthermore, since the developer moves away from the developer carrier and moves toward the regulating member, filming in the developer carrier is less likely to occur.
(Aspect V)
In the aspect U, the regulating member voltage applying means such as the developing bias power supply 142 and the Zener diode 145 applies a voltage for directing the developer from the regulating member such as the doctor blade 45 to the developer carrying member such as the developing roller 42 to the regulating member. To do.
According to this, as described in the second modification, the developer can be moved from the regulating member side to the developer carrying member side, and the opportunity for the developer to be frictionally charged increases. As a result, weakly charged or reversely charged developer is reduced. Therefore, it is possible to suppress the weakly charged or reversely charged developer from reaching the developing region, and it is possible to suppress the occurrence of background contamination. Further, since the developer moves away from the regulating member and moves toward the developer carrying member, the developer is hardly fixed on the regulating member.

Claims

A developer carrying member that carries the developer on the surface, moves the surface endlessly, and supplies the developer to the latent image on the surface of the latent image carrying member in a developing region facing the latent image carrying member;
A regulating member that regulates the amount of developer that contacts the surface of the developer carrying member and moves toward the developing region;
In the developing device having a concavo-convex shape on the surface of the developer carrying member,
A regulating member voltage applying means for applying a voltage to the regulating member;
The regulating member voltage application means includes a first regulating voltage for directing the developer from the developer carrying member to the regulating member, a second regulating voltage for directing the developer from the regulating member to the developer carrying member, A developing device characterized in that an alternating voltage for alternately applying is applied to the regulating member.

The developing device according to claim 1.
The developing device characterized in that the regulating member voltage applying means applies a voltage of a magnitude that does not cause a discharge in the developer layer existing between the regulating member and the developer carrier to the regulating member. .

The developing device according to claim 1 or 2,
A developing device characterized in that the distance from the top surface of the convex portion having the concavo-convex shape to the bottom surface of the concave portion is constant.

In the developing device according to any one of claims 1 to 3,
The developer carrier is configured to face the latent image carrier in a non-contact state with a certain distance in the development region,
A developing device comprising developing bias applying means for applying an alternating voltage to the developer carrying member.

The developing device according to claim 4.
The regulating member voltage applying means generates an alternating voltage to be applied to the regulating member by dropping the alternating voltage applied to the developer carrying member by the developing bias applying means with a voltage dropping means. Development device.

The developing device according to claim 5.
A developing device wherein the voltage drop means is a Zener diode.

The developing device according to any one of claims 1 to 6,
The magnitude of the first regulation voltage is V1,
F1 is an average adhesion force between the developer and the developer carrier.
The average charge amount of the developer is q,
When the distance from the top of the concavo-convex convex portion on the surface of the developer carrying member to the bottom of the concave portion is the maximum depth d,
A developing device satisfying a relationship of q × V1 / d> F1.

The developing device according to any one of claims 1 to 7,
The magnitude of the second regulation voltage is V2,
The average adhesion force between the developer and the regulating member is F2,
The average charge amount of the developer is q,
When the distance from the top of the concavo-convex convex portion on the surface of the developer carrying member to the bottom of the concave portion is the maximum depth d,
A developing device satisfying a relationship of q × V2 / d> F2.

The developing device according to any one of claims 1 to 8,
A regulation nip width that is a length in the direction of surface movement of the developer carrier at a regulation nip that is a contact portion between the regulation member and the developer carrier is a,
The linear velocity of the developer carrier is v,
When the frequency of the alternating voltage is f,
A developing device satisfying a relationship of a / v> 1 / f.

The developing device according to any one of claims 1 to 9,
2. A developing device according to claim 1, wherein a ratio of time for applying the second regulation voltage is higher than a ratio of time for applying the first regulation voltage.

The developing device according to claim 10,
The voltage applied to the developer carrier is
A third voltage for directing the developer from the developer carrier to the latent image carrier;
An alternating voltage comprising a fourth voltage for directing the developer from the latent image carrier to the developer carrier,
The application time of the first regulation voltage is “t1”, and the application time of the second regulation voltage is “t2”.
When the application time of the third voltage is “t3” and the application time of the fourth voltage is “t4”, the relationship is “t3 ≠ t4”,
In the case of “t3> t4”, the relationship of “t1 = t4” and “t2 = t3” is satisfied,
In the case of “t3 <t4”, the developing device satisfies the relationship of “t1 = t3” and “t2 = t4”.

The developing device according to any one of claims 1 to 9,
2. A developing device according to claim 1, wherein a ratio of time for applying the first regulation voltage is higher than a ratio of time for applying the second regulation voltage.

The developing device according to any one of claims 1 to 12,
The ratio between the time for applying the first regulation voltage and the time for applying the second regulation voltage is changed according to the use environment of the developing device and the surface movement distance of the developer carrier. Development device.

The developing device according to any one of claims 1 to 13,
A developing device characterized in that the frequency of the alternating voltage is changed in accordance with the surface movement distance of the developer carrier.

The developing device according to any one of claims 1 to 14,
A developing device characterized in that the frequency of the alternating voltage is changed according to the use environment of the developing device.

The developing device according to any one of claims 1 to 15,
A developing device characterized in that the frequency of the alternating voltage is changed after a large amount of developer is replenished in the developing device and during normal operation.

The developing device according to any one of claims 1 to 16,
The voltage applied to the developer carrier is
A third voltage for directing the developer from the developer carrier to the latent image carrier;
An alternating voltage comprising a fourth voltage for directing the developer from the latent image carrier to the developer carrier,
When the frequency of the alternating voltage applied to the regulating member is “f1” and the frequency of the alternating voltage applied to the developer carrying member is “f2,” the relationship “f1 ≠ f2” is satisfied. A developing device.

At least a latent image carrier;
Charging means for charging the surface of the latent image carrier;
Latent image forming means for forming an electrostatic latent image on the latent image carrier;
In an image forming apparatus having developing means for developing the electrostatic latent image into a toner image,
An image forming apparatus using the developing device according to claim 1 as the developing unit.

In an image forming apparatus comprising a latent image carrier that carries a latent image and a developing unit that develops the latent image on the latent image carrier, at least the latent image carrier and the developing unit are shared as one unit. In a process cartridge configured to be held in a holding body and detachable integrally with the image forming apparatus main body,
18. A process cartridge using the developing device according to claim 1 as the developing means.

A developer carrying member that carries the developer on the surface, moves the surface endlessly, and supplies the developer to the latent image on the surface of the latent image carrying member in a developing region facing the latent image carrying member;
A regulating member that regulates the amount of developer that contacts the surface of the developer carrying member and moves toward the developing region;
In the developing device having a concavo-convex shape on the surface of the developer carrying member,
A regulating member voltage applying means for applying a voltage to the regulating member;
The developing device characterized in that the regulating member voltage applying means applies a voltage for moving the developer between the developer carrying member and the regulating member to the regulating member.

The developing device according to claim 20, wherein
The developing device according to claim 1, wherein the regulating member voltage applying unit applies a voltage for directing the developer from the developer carrying member to the regulating member.

The developing device according to claim 20,
The developing device according to claim 1, wherein the regulating member voltage applying means applies a voltage for directing the developer from the regulating member to the developer carrying member.