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:
Jun. 03, 1997
Filed:
Jun. 02, 1995
Yasushige Nakamura, Kawasaki, JP;
Norio Sawatari, Kawasaki, JP;
Tsuneo Watanuki, Kawasaki, JP;
Fumio Takei, Kawasaki, JP;
Toru Takahashi, Kawasaki, JP;
Yasuyuki Furuse, Kawasaki, JP;
Fujitsu Limited, Kanagawa, JP;
Abstract
A toner used meets the requirement that the value determined by the equation 6/(d.sub.t .multidot..rho..sub.t .multidot.S), wherein d.sub.t is the volume average particle diameter of the toner, .rho..sub.t is the density of the toner, and Fs is the specific surface area of the toner, is in the range of 0.75 to 0.90, and the amount of electrification as measured by a magnet blow-off method is in the range of 10 to 40 .mu.C/g in terms of absolute value. A carrier used meets the requirement that the magnetic susceptibility is not less than 90 emu/g (at 1 kOe), the specific surface area is not less than 1000 cm.sup.2 /g to 1800 cm.sup.2 /g, the electric resistivity is 10.sup.6 to 10.sup.12 .OMEGA.cm, and the average particle diameter is 20 to 100 .mu.m.