Patent ID: 6219514
Filing Date: 2001-04-17
Classification: G03G

Abstract:
An image forming apparatus comprising:an image bearing member for bearing a latent image, said image bearing member including a surface layer having a volume resistivity of 10.sup.9 to 10.sup.14 .OMEGA..multidot.cm;a charging member having therein first magnetic field generating means, said charging member bearing charging magnetic particles on an outer surface and making the charging magnetic particles contact with the surface layer of said image bearing member, thereby charging said image bearing member; anda developer bearing member having therein second magnetic field generating means, said developer bearing member bearing a developer having toner and developing magnetic particles on an outer surface, carrying the developer to a developing area, and making the developing magnetic particles contact with the surface layer of said image bearing member in the developing area, thereby developing the latent image,wherein when a half-value width of a first magnetic pole which is closest to said image bearing member of the first magnetic field generating means is set to .alpha..degree., an angle formed between a straight line connecting between a closest point to said image bearing member on said charging member and a center of said charging member and a straight line connecting between a point of a maximum magnetic flux density of the first magnetic pole on said charging member and the center of said charging member is set to .theta.c.degree., a half-value width of a second magnetic pole which is closest to said image bearing member of the second magnetic field generating means is set to .beta..degree., and an angle formed between a straight line connecting a point which is closest to said image bearing member on said developer bearing member and a center of said developer bearing member and a straight line connecting between a point of a maximum magnetic flux density of the second magnetic pole on said developer bearing member and the center of said image bearing member is set to .theta.d.degree., .alpha.>.beta. and .theta.c<.theta.d are satisfied.