An object of the invention is to provide a toner which is effective in improving
image quality while inhibiting white-background
fouling, residual-image phenomenon (ghost), blurring (suitability for
solid printing), and the like that occur depending on the proportion of a
fine powder having a particle
diameter not larger than a specific value, and which has satisfactory removability in cleaning, mitigates problems concerning
fouling, etc. in long-term use even on a high-speed printer, and attains excellent image stability. Another object is to provide an image-forming apparatus and a toner
cartridge each employing the toner. The invention provides a toner for electrostatic-image development satisfying all of the following (1) to (4) or a toner for electrostatic-image development which is a toner containing a
charge control agent and satisfying all of the following (5) to (7). The invention further provides an image-forming apparatus and a toner
cartridge each employing the toner.(1) To have a volume-median
diameter (Dv50) of from 4.0 μm to 7.5 μm.(2) To have an average degree of circularity of 0.93 or higher.(3) A volume-median
diameter (Dv50) of the toner and
population number % of toner particles having a particle diameter of from 2.00 μm to 3.56 μm (Dns) in the toner satisfy the relationship Dns≦0.233 EXP(17.3 / Dv50).(4) To have a
coefficient of variation in number of 24.0% or lower.(5) To have a volume-median diameter (Dv50) of from 4.0 μm to 7.5 μm.(6) A volume-median diameter (Dv50) of the toner and
population number % of toner particles having a particle diameter of from 2.00 μm to 3.56 μm (Dns) in the toner satisfy the relationship Dns≦0.233 EXP(17.3 / Dv50).(7) When the
charge control agent on the toner surface is cleaned, the
resultant depressions have an
average diameter of 500 nm or smaller.