Image forming apparatus and image forming method

An image forming apparatus comprising:

• an electrostatic-latent-image holding member;
• a charging unit that charges the electrostatic-latent-image holding member;
• an electrostatic-latent-image forming unit that forms an electrostatic latent image on a surface of the charged electrostatic-latent-image holding member;
• a plurality of developing units that each supply a developer containing a toner to the electrostatic latent image formed on the surface of the electrostatic-latent-image holding member and form a toner image;
• a transfer unit that transfers the toner image onto a recording medium to form a transfer image;
• and
• a fixing unit that fixes the transfer image,
• wherein the plurality of developing units separately contain a toner A and a toner B that satisfy relationships (1) and (2) below and have similar colors;
• the toner A includes a binder resin containing a polyester about 90 mass % or more of the binder resin, the polyester contains an amorphous polyester having an alkyl side chain and a crystalline polyester, and when a glass transition temperature of the amorphous polyester is defined as Tga, the crystalline polyester has a melting temperature Tma of about (Tga+10)° C. or more and about (Tga+30)° C. or less;
• the toner B contains a binder resin containing a polyester about 90 mass % or more of the binder resin, the polyester contains an amorphous polyester having an alkyl side chain and a crystalline polyester, and when a glass transition temperature of the amorphous polyester is defined as Tgb, the crystalline polyester has a melting temperature Tmb of about (Tgb+10)° C. or more and about (Tgb+30)° C. or less;
• and about 90 mass % of the binder resin of the toner A and about 90 mass % of the binder resin of the toner B are the same resin;
• (1) relationship of Ta>Tb where Ta represents a flow tester ½ effluent temperature of the toner A and Tb represents a flow tester ½ effluent temperature of the toner B;
• and
• (2) relationship of Aa>Ab where Aa represents an amount of an aluminum (with reference to net intensity) in the toner A measured with fluorescent X-ray and Ab represents an amount of an aluminum (with reference to net intensity) in the toner B measured with fluorescent X-ray.