Patent ID: 7209684

Claim:
An image forming apparatus comprises an image carrier, a developing portion which feeds particles of developing agent to a electrostatic latent image to enable the developing agent to adhere onto the surface of an image carrier to form a developing agent image, and a transferring portion which transfers the developing agent image to a transferring medium; wherein the ratio of the particles of developing agent having a particle diameter of not more than A×0.5 (μm) (wherein A is a 50% average particle diameter (μm)) and the ratio of the particles of developing agent having a particle diameter of not less than A×1.5 (μm) (wherein A is a 50% average particle diameter (μm)) are both confined to not more than 5% by number in a number particle size distribution; the ratio of the developing agent having an adhesive strength of not more than 1.3×10 −8 (N) is confined to 10% by weight or less and the ratio of the developing agent having an adhesive strength of not less than 3×10 −7 (N) is confined to 5% by weight or less in a distribution of adhesive strength to the surface of the image carrier.