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:
Feb. 06, 2007
Filed:
May. 13, 2004
Masahide Yamashita, Tokyo, JP;
Tomio Kondou, Numazu, JP;
Kohsuke Suzuki, Numazu, JP;
Ricoh Company, Ltd., Tokyo, JP;
Abstract
A carrier including a manganese ferrite core material having a layer on its surface such that 0.1≦K≦30, where K=(S/M)×100, S and M represent the standard deviation and average of M(M+M), respectively, M ranging from 0.05 to 0.45, and Mand Mrepresent the content of iron and manganese, respectively, in a carrier particle. The carrier has a magnetization ranging from 45 to 75 emu/g at 1,000 Oe, a mass-averaged particle diameter, D, ranging from 25 to 65 μm and carrier particles having a particle diameter not greater than 12 μm are included in an amount not greater than 0.3% by weight, and a ratio, DD, ranging from 1 to 1.3, where Dis a number-averaged particle diameter of the carrier.