Image forming method and image forming apparatus
US5215845A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Oct 21, 1991 |
| Grant date | Jun 1, 1993 |
| Priority date | — |
| Expiry date | Oct 21, 2011 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03G15/0928
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
An electrostatic image supporting member which supports an electrostatic image and a toner carrying member for conveying a magnetic toner are disposed in a development section with a specified gap therebetween. The toner carrying member has a base whose surface has an average surface roughness (Ra) of 1.0 to 3.0 .mu.m. A resin coating containing electrically conductive fine particles is formed on the base surface at a density of 4 to 12 g per 1 m.sup.2. The outer layer of the coating has an Ra from 0.8 to 3.0 .mu.m. The toner carrying member carries an electrically insulating magnetic toner containing at least a binder resin and a magnetic component, and satisfying the conditions of a volumetric average particle size of 4.5 to 8 .mu.m, a BET specific surface area of 1.8 to 3.5 m.sup.2 /g, a charge amount of -20 to -35 .mu.c/g, a loose-state apparent density of 0.40 to 0.52 g/cm.sup.3, and a true specific gravity of 1.45 to 1.8. The magnetic toner is formed into a layer having a thickness smaller than the dimension of the gap by a member for regulating the thickness by pressing the toner against the toner carrying member. The magnetic toner is then conveyed to the development sectio…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.