| 摘要 |
PURPOSE:To prevent toner from being pulverized to a fine powder and attaching to a carrier surface, etc. especially in the magnetic brush development method, and to always obtain a superior image, by mixing resin coated carrier particles with a fine hard powder to bring both into full contact and to form a rugged rough surface on each particle. CONSTITUTION:Carrier particles obtained by coating the reduced iron powder surface with polyvinyl fluoride or the like resin and a fine hard powder, such as diamond dust or silicon carbide in an equal mixing weight ratio are mixed and brought into full contact for a proper treatment time. The resultant mixture is sucked in a strong magnetic field to separate only the fine hard powder, leaving the coated carrier particles with rugged surfaces in the magnetic field. These carrier particles and a toner are well mixed to form a developer for use in a magnetic brush developing device, thus permitting an always sharp, high contrast superior electrophotographic image free from rubbed parts or uneven parts. |
