Image forming apparatus with improved developing device
US6721526B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Sep 26, 2002 |
| Grant date | Apr 13, 2004 |
| Priority date | — |
| Expiry date | Sep 26, 2022 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03G2215/0609
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
An image forming apparatus is provided for obtaining excellent developing properties using toner with small particle diameters and for forming high-quality visual images. In a developing device of an image forming apparatus, a two-component developer is used which satisfies conditions that volume mean particle diameter dt of a toner is 3˜5 &mgr;m (Condition 1), volume mean particle diameter dc of a carrier is 5 dt˜10 dt (Condition 2), and a weight ratio Rw of the toner and the carrier is 1.6 (dt/dc) ×(&rgr;t/&rgr;c)˜2.4 (dt/dc)×(&rgr;t/&rgr;c) (Condition 3, where &rgr;t and &rgr;c are density of the toner and the carrier, respectively). A main magnetic pole M of a rotary sleeve is arranged in the vicinity of the closest position of the rotary sleeve and an image forming body, and the closest distance D between the rotary sleeve and the image forming body satisfies a condition that D is 0.5 H˜0.8 H for the free tip height H of a magnetic brush B of the main magnetic pole M. It is preferable that the actual supplied amount of the toner is regulated within a specific range.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.