The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
May. 04, 1999
Filed:
Aug. 05, 1997
Applicant:
Inventors:
Assignee:
Hitachi Metals, LTD., Tokyo, JP;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
G03G / ;
U.S. Cl.
CPC ...
4301066 ; 252 6261 ;
Abstract
An Li--Mn type ferrite carrier for use in electrophotographic development comprising ferrite particles having a chemical composition of 3 to 15% of Li.sub.2 O, 5 to 35% of MnO and 60 to 90% of Fe.sub.2 O.sub.3, each in terms of percent by mole. The ferrite particles consisting essentially of crystal grains having an average grain size of 1 to 50 .mu.m. The surface of the crystal grains is provided with a minute roughness or unevenness during the production of the ferrite carrier. The minute roughness on the grain surface enhances the ability of the ferrite carrier to triboelectrically charge the toner and the bonding strength of the resin coating to the carrier surface.