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. 09, 1987
Filed:
Nov. 25, 1985
Yasushi Kamezaki, Sakai, JP;
Mita Industrial Co., Ltd., Osaka, JP;
Abstract
A developing method for forming a toner image of high quality which comprises supplying a two-component developer composed of a mixture of magnetic carrier particles and toner particles chargeable by frictional contact with the magnetic carrier particles onto a development sleeve comprised of a non-magnetic sleeve and provided therein, a magnet having alternately and circumferentially arranged magnetic poles of different polarities to thereby form a magnetic brush of the developer, and bringing the surface of a photosensitive drum bearing a latent electrostatic image into frictional contact with the magnetic brush while a bias voltage is applied between the photosensitive drum and the sleeve thereby to form a toner image corresponding to the latent electrostatic image; characterized in that a brush cutting doctor is disposed on the non-magnetic sleeve so that the tip of the doctor is positioned nearly centrally between two magnetic poles of different polarities, and the development is carried out while moving the photo-sensitive drum and the development sleeve in the same direction at the site of frictional contact and the concentration (Ct, %) of the toner in the developer satisfies the following equation ##EQU1## wherein Sc is the specific surface area (cm.sup.2 /g) of the carrier, St is the specific surface area (cm.sup.2 /g) of the toner, and k is a number of from 0.80 to 1.14.