| 摘要 |
<P>PROBLEM TO BE SOLVED: To solve the problems of carrier deposition, roughening, edge effect, surface stain in formation of an image having a small image area due to burying of external additives, and shortening of the lifetime of a developer due to scraping of a carrier film, the problems caused when a polymerized toner having a small particle diameter and a carrier are used. <P>SOLUTION: In the image forming apparatus, a toner used is a polymerized toner having a volume average particle diameter of 5.5-7 μm; a volume average particle diameter of a magnetic carrier is 20-40 μm; a saturation magnetization of the magnetic carrier in a magnetic field of 10 kOe is ≥70 emu/g; the gap (Gp) between a photoreceptor 11Y and a developing sleeve 22Y is ≤0.4 mm; a surface of the developing sleeve has been sandblasted; and an electric field generated by a developing electric field generating means is an alternating electric field having a frequency of ≥5.4 kHz and a peak-to-peak voltage of ≤900 V. <P>COPYRIGHT: (C)2005,JPO&NCIPI |
