To provide non-spherical particles in a uniform figure having a particle diameter of not more than 3 m, the particles exhibiting good transfer property and good cleaning property in both of dry and wet processes when used as an electrophotographic developer, achieving formation of an image with high picture qualities, and being easily collected by a filter in an image forming apparatus when used in a dry process, which can suppress adverse influences on a human body by scattered particles out of an image forming apparatus, and to provide a toner and a developer containing the non-spherical particles, a developing device for developing an image by use of the developer, and an image forming apparatus equipped with the developing device.
The developer comprises non-spherical particles having a volume-average particle diameter of 0.1 m or more and 3 m or less, a shape factor SF-1 of 125 or more and 145 or less, and a shape factor SF-2 of 115 or more and 140 or less. An image is formed by an image forming apparatus 1, 201 equipped with a developing device 14, 214 charged with the above developer.
MATSUMOTO KATSURU
NAGAOKA AYAE
Takeshi Sugiyama