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:
Jul. 20, 1999
Filed:
Aug. 26, 1997
Masahisa Ochiai, Fukaya, JP;
Masumi Asanae, Kumagaya, JP;
Toshihiko Noshiro, Kumagaya, JP;
Koji Noguchi, Saitama, JP;
Hitachi Metals, Inc., , JP;
Abstract
An image forming method for developing an electrostatic latent image on an image-bearing member that moves bearing electrostatic latent images formed of a two-component magnetic developer is described. The method includes the steps of providing a rotatable cylinder for supporting and conveying said magnetic developer, the cylinder including a permanent magnet with a plurality of magnetic poles provided on the surface. Magnetic carriers in the magnetic developer are attracted and conveyed on the surface of the permanent magnet, the magnetic carriers having an average particle size of 5 to 20 .mu.m and opposite to toner in polarity of charge. A carrier particle magnetization .sigma..sub.1000 in a magnetic field of 1000 Oe so as to amount to 50 emu/g or less is also used. The method also includes a surface magnetic flux density ranging from 50 to 1200 G, and a value of h, defined as .pi.D.multidot.Vp/(M.multidot.Vm), of 2 or less wherein Vp (mm/s) is the moving speed of the image-bearer, and D (mm), M, and Vm (mm/s) are the outer diameter, the number of magnetic poles, and peripheral speed of the permanent magnet, respectively.