| 摘要 |
PURPOSE:To prevent the fogging and generation of an edge effect by using a two-component system non-contact developing method for forming a thin layer having gaps between the carrier particles and particles groups in a developing agent layer on the surface of a developing sleeve. CONSTITUTION:An electrostatic latent image carrier drum 1 and the developing sleeve 2 are rotated in the direction as shown by the arrows, the sleeve 2 is formed with a nonmagnetic electrically conductive substance, and a DC- superimposed AC bias 13 is impressed on the sleeve 2. The developing agent 10 consisting of the mixture of a toner 15 and a magnetic carrier 16 is held and conveyed by the magnetic poles N3 and S2 on the sleeve 2. The agent 10 is cut by a first blade 6 and a second blade 14 into thin layers so that the gaps are formed between the carrier particles 16 and particles groups on the sleeve 2. When the carrier covering rate on the sleeve surface is adjusted to 50-80%, the difference in the electrification quantity between the toner particle 15 on the sleeve 2 and the carrier particle 16 is reduced, and the toner particle 15 on the sleeve can be utilized for improving the picture image density while preventing fogging. As a result, fogging and the generation of an edge effect can be prevented.
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