Patent ID: 7625685

Claim:
An image forming method using a mono-component toner, the image forming method comprising: a photosensitive body drum formed an electrostatic latent image and a developing unit with a developing sleeve, the toner is supplied by a jumping developing method from a toner thin layer formed on the surface of the developing sleeve to the electrostatic latent image on the surface of the photosensitive body drum in order to form a toner image, wherein ten-point average surface roughness (Rz) of the surface on the developing sleeve is from 2 to 8 μm and the coarse powder distribution (S) of the toner particles satisfies a following formula (1), coarse powder distribution ( S )=(50− A )/2≧17(volume %/μm) (1) (wherein A: volume % of coarse powdery material having particle size larger Than D 50 based on volume by 2 μm or more).