Patent ID: 7286781

Claim:
An image forming apparatus, comprising: a developer comprising a releasing agent and a binder resin; a developing unit that develops a latent image to form a developer image using said developer; a transferring unit that transfers said developer image to a printing medium; and a fixing unit that feeds said printing medium at a speed higher than or equal to 150 mm/s to fix said developer image to said printing medium; wherein a melting point Tw of said releasing agent is higher than or equal to a softening temperature Ts of said developer measured by a capillary rheometer of a constant shear stress type; wherein said melting point Tw of said releasing agent is lower than or equal to a melting temperature Tm of said developer measured by a ½ method; wherein said releasing agent comprises a first releasing agent and a second releasing agent, and wherein melting points Tw 1 and Tw 2 of said first and second releasing agents, said softening temperature Ts, and said melting temperature Tm satisfy the following relationship: Ts≦Tw1<Tf Tf≦Tw2<Tm where Tf is a temperature at which said developer starts flowing measured by said capillary rheometer of said constant shear stress type; wherein the melting point Tw 1 of the first releasing agent is higher than or equal to 83° C., and lower than or equal to 89° C.; and wherein the melting point Tw 2 of the second releasing agent is higher than or equal to 94° C., and lower than or equal to 100° C.