Carrier for use in electrophotography, two component-type developer and image forming method
US5439771A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jul 28, 1993 |
| Grant date | Aug 8, 1995 |
| Priority date | — |
| Expiry date | Jul 28, 2013 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03G9/1075
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A two component-type developer for electrophotography showing improved electrophotographic performances and also free from carrier adhesion (undesirable carrier transfer to the photosensitive member and recording materials) is constituted by using a magnetic carrier comprising a soft magnetic material of 5-100 .mu.m in particle size. The carrier has a bulk density of at most 3.0 g/cm.sup.3, and magnetic properties including: a magnetization of 30-150 emu/cm.sup.3 under a magnetic field strength of 1000 oersted, and relationships (1) and (2): EQU .vertline..sigma..sub.1000 -.sigma..sub.300 .vertline./.sigma..sub.1000 .ltoreq.0.40 (1) wherein .sigma..sub.1000 and .sigma..sub.300 denote magnetizations (emu/cm.sup.3) under magnetic field strengths of 1000 oersted (Oe) and 300 oersted (Oe), respectively, and EQU 0.15 (emu/cm.sup.3.Oe).ltoreq..vertline..sigma..sub.100 -.sigma..sub.r .vertline./100 (Oe) (2) wherein .sigma..sub.100 and .sigma..sub.r denote magnetizations (emu/cm.sup.3) under magnetic field strengths of 100 (Oe) and zero (Oe), respectively.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.