IMAGE FORMING APPARATUS

• Main Authors: SAKAMAKI TOMOYUKI, FUJITA HIDEKI, ABE MASASHI, ARIIZUMI OSAMU, WAKISAKA MASASHI, TANAKA TOMOHIRO
• Format: Patent
• Language: English; Japanese
• Published: 24.08.2022
• Subjects: CINEMATOGRAPHY; ELECTROGRAPHY; ELECTROPHOTOGRAPHY; HOLOGRAPHY; MAGNETOGRAPHY; PHOTOGRAPHY; PHYSICS

To provide a developing device having a toner supply roller that supplies only toner to a developing roller, where toner that separated from the developing roller without being used for development is prevented from scattering to the outside of the developing device during an image forming operation.SOLUTION: During an image forming operation, an image forming apparatus applies a bias to each of a toner supply roller, a developing roller, and a conductive member so as to form a first potential difference between the toner supply roller and the developing roller so that a normally-charged toner is directed from the toner supply roller to the developing roller, form a second potential difference between the conductive member and the developing roller so that the normally-charged toner is directed from the conductive member to the developing roller, and form a third potential difference between the conductive member and the toner supply roller so that the normally-charged toner is directed from the conductive member to the toner supply roller. The second potential difference is larger than the first potential difference and larger than the third potential difference.SELECTED DRAWING: Figure 2 【課題】 現像ローラにトナーのみを供給するトナー供給ローラを有する現像装置に関して、画像形成動作中において、現像に用いられる事なく現像ローラから離脱したトナーが現像装置の外部に飛散する事を抑制する。【解決手段】 画像形成動作中において、トナー供給ローラと現像ローラとの間で正規帯電トナーがトナー供給ローラから前記現像ローラに向かうような第１の電位差を形成し、導電部材と現像ローラとの間で正規帯電トナーが導電部材から現像ローラに向かうような第２の電位差を形成し、且つ、導電部材とトナー供給ローラとの間で正規帯電トナーが導電部材からトナー供給ローラに向かうような第３の電位差を形成するように、トナー供給ローラ、現像ローラ、及び導電部材のそれぞれにバイアスを印加し、第２の電位差は、前記第１の電位差よりも大きく、且つ、前記第３の電位差よりも大きい。【選択図】 図２