Patent ID: 7029809

Claim:
A toner kit comprising a non-magnetic black toner having at least carbon black, and at least three color toners, wherein said black toner has a weight-average particle diameter represented by D 4 b and a one-point method BET specific surface area represented by Sb, and the color toners, other than the black toner, each having a weight-average particle diameter represented by D 4 c and a one-point method BET specific surface area represented by Sc, wherein said black toner and color toners satisfy the following relations (1) and (2): 0.60 ≦D 4 c/D 4 b≦ 0.96, Relation (1) 0.750 ≦Sc/Sb≦ 1.000, Relation (2) and each have an average circularity of from 0.950 to 1.000 and a circularity standard deviation of less than 0.040 as measured with a flow type particle image analyzer, and wherein, where the proportion of 5.04 μm or smaller particles that is calculated from number-based particle size distribution of said black toner is represented by Ub 5.04 (% by number), the proportion of 5.04 μm or smaller particles that is calculated from number-based particle size distribution of each of said color toners is represented by Uc 5.04 (% by number), the proportion of 12.7 μm or larger particles that is calculated from weight-based particle size distribution of said black toner is represented by Ub1 2.7 (% by weight), and the proportion of 12.7 μm or larger particles that is calculated from weight-based particle size distribution of each of said color toners is represented by Uc 12.7 (% by weight), the toners satisfy the following relations (3), (4) and (5): 1.2 ≦Uc 5.04 /Ub 5.04 ≦6.0, Relation (3) Ub 12.7 ≦2.0, Relation (4) Uc 12.7 ≦1.0. Relation (5)