Patent · US Expired

Carrier and two-component developer for electrophotography

US6740461B2 · kind B2 · utility

3Cited by
0References
17Claims
0Family size

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Key dates

Filing dateDec 20, 2002
Grant dateMay 25, 2004
Priority date
Expiry dateDec 20, 2022

Classification

  • Technology area (CPC G)Physics
  • CPC primaryG03G9/1136
  • WIPO fieldOptics
  • WIPO sectorInstruments

Abstract

A carrier is composed of carrier particles, each carrier particle having a core particle containing at least a magnetic material and a surface coating layer provided on the core particle containing at least a resin, the surface coating layer being constituted of a plurality of regions, the regions being separately formed and joined together to form a complex configuration, and having different phase lags when the surface coating layer is subjected to scanning by phase imaging measurement using a scanning probe microscope in a tapping mode, wherein a region having a phase lag over the average phase lag obtained from Eavg=&Sgr;(E(i)·S(i))/&Sgr;S(i) has an area SO, and SO and &Sgr;S(i) are in a relationship of 10%≦SO/&Sgr;S(i)×100≦90% when each region comprises a component A(i) having an area S(i) and a phase lag E(i), in which i represents the number of regions with different phase lags. A two-component developer employs the above-mentioned carrier.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.