| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an image forming apparatus in which a toner has good charging property and charge buildup performance and toner spent on a carrier, etc., occurs infrequently even after outputting several tens of thousands of images, and which has both high durability and low maintenance nature as an image forming system, and an image forming method. <P>SOLUTION: The image forming apparatus contains a developing device configured to turn an electrostatic latent image on an image bearing member into a toner image using a toner in a two-component developer by the action of a development field, wherein the toner is a toner including a binder resin and a colorant and having an external additive added to a surface thereof, and after outputting 20,000 images having an image area of 20% with the developing device, a carrier spent index is 0.1-2.0 atomic% and a toner external additive agglomerate index is 0.1-80.0. The carrier spent index represents a surface proportion of spent titanium on a carrier surface evaluated by XPS (X-ray photoelectron spectroscopy), and the toner external additive agglomerate index represents an amount of external additive agglomerates in the toner. <P>COPYRIGHT: (C)2007,JPO&INPIT |
