Patent ID: 7454160
Filing Date: 2008-11-18
Classification: G03G

Abstract:
1. A developing apparatus comprising: a cylindrical developer carrying member disposed opposite to an image bearing member with a gap between said developer carrying member and the image bearing member, said developer carrying member carrying and conveying a magnetic mono-component developer, said developer carrying member developing an electrostatic image formed on the image bearing member with the developer; and a magnetic field generating member disposed in said developer carrying member, wherein an alternate electric field is formed between the image bearing member and said developer carrying member, wherein said developer carrying member has an outer diameter of not less than 8 mm and not more than 12 mm, wherein said magnetic mono-component developer has: a saturation magnetization of not less than 20 AM a magnetization of not less than 70% and not more than 80% of the saturation magnetization when the magnetic field is lowered to 700 oersteds; a magnetization of not less than 50% and not more than 62% of the saturation magnetization, when the magnetic field is lowered to 500 oersteds; and an average degree of circularity of not less than 0.960.