The invention provides a developing agent that includes color toners and a black toner. The color toners include a yellow toner, a magenta toner and a cyan toner. Each of the yellow toner, the magenta toner and the cyan toner contains, as a binder resin, a mixture of an H form of polyester mainly containing higher molecular components polyester, and an L form of polyester mainly containing lower molecular components of polyester. The black toner contains, as a binder resin, a mixture of an H form of polyester mainly containing higher molecular components of polyester, and an L form of polyester mainly containing lower molecular components polyester, and a crystalline polyester resin.
The present application is a divisional of U.S. application Ser. No. 10/391,602, filed Mar. 20, 2003, now U.S. Pat. No. 6,872,499 the entire contents of which are incorporated herein by reference.
