| 摘要 |
PROBLEM TO BE SOLVED: To enhance high image quality by magnetic contact development, to miniaturize the apparatus, to eliminate a ghost (particularly at an edge) by a relation between a D blade (a blade for regulating a quantity of developer) and a magnetic pole, and to eliminate the need for a cleaner, etc. SOLUTION: In the magnetic contact development using magnetic spherical toner, the NE length (free length) of the D blade 60c is made sufficiently long, and thereby, the steady supply of toner and a ghost at an edge by electrification, and the solid followup ability and fogging are reconciled. In a magnetic contact developing device that has a magnet 60a within an elastic sleeve 60b and supplies spherical toner by magnetic force, a relation between the free length L of the D blade 60c, a developing sleeve radius R and the Br adjustment widthθh of the nearest pole is set to 0.3≤L/(R×tanθh)≤1.2, and the maximum flux density at a take-in section (NE) is set to ¾Br¾/¾B¾≥0.5. COPYRIGHT: (C)2007,JPO&INPIT |
