IMAGE FORMING APPARATUS

• Main Authors: HAGIWARA EMI, KONO YASUNORI, INOUE RYO, USAMI HIROICHI, NAGASE YUKIO, ISHIDA SHINTARO
• Format: Patent
• Language: English; Japanese
• Published: 15.06.2017
• Subjects: CINEMATOGRAPHY; ELECTROGRAPHY; ELECTROPHOTOGRAPHY; HOLOGRAPHY; MAGNETOGRAPHY; PHOTOGRAPHY; PHYSICS

PROBLEM TO BE SOLVED: To provide an image forming apparatus capable of suppressing the decrease of carrier chargeability, according to the degree of the contamination of a carrier caused by an external additive.SOLUTION: An image forming apparatus includes a developing sleeve which carries and conveys a developer having a toner to which the external additive is added and the carrier, a photoreceptive drum which can carry an electrostatic image, a developing bias application part which applies a developing bias having an AC component to the developing sleeve carrying the developer and develops the electrostatic image formed on the photoreceptive drum to a toner image, a sound collecting microphone which detects a vibration generated between the carrier carried on the developing sleeve and the photoreceptive drum and outputs the vibration as a signal, during the application of the developing bias, and a control part which executes reduction processing for reducing the adhesion amount of the external additive to the carrier (step S7), when the signal outputted from the sound collecting microphone is larger than a set value (step S5).SELECTED DRAWING: Figure 2 【課題】外添剤によるキャリアの汚染度に応じて、キャリア帯電能の低下を抑制できる画像形成装置を提供する。【解決手段】外添剤が添加されたトナー及びキャリアを有する現像剤を担持して搬送する現像スリーブと、静電像を担持可能な感光ドラムと、現像剤を担持した現像スリーブに対し、交流成分を有する現像バイアスを印加して、感光ドラムに形成された静電像をトナー像に現像する現像バイアス印加部と、現像バイアスの印加中に、現像スリーブに担持されたキャリアと感光ドラムとの間で発生する振動を検出して信号として出力する集音マイクと、集音マイクから出力された信号が設定値より大きい場合は（ステップＳ５）、キャリアへの外添剤の付着量を低減させる低減処理を実行する（ステップＳ７）制御部と、を備える。【選択図】図２