Patent ID: 6078768
Filing Date: 2000-06-20
Classification: G03G

Abstract:
A developing apparatus for developing an electrostatic latent image so as to form a toner image on a photoreceptor element, comprising:a developer storing section which stores two-component developer including toner particles and magnetic carrier particles;a developing sleeve arranged opposite the photoreceptor element so as to provide a developing region therebetween, said developing sleeve comprising a hollow cylinder and being rotatable in a direction such that the two-component developer is conveyed upward at the developing region;a first magnetic field generator provided inside the developing sleeve and having plural magnetic poles to attract the magnetic carrier particles on the developing sleeve so as to convey the two-component developer when the developing sleeve is rotated, wherein said plural magnetic poles include a first magnetic pole and a second magnetic pole which both have a same polarity and which are arranged side by side so as to generate a repulsing magnetic field to remove the carrier particles from the developing sleeve;a developer layer thickness regulator which regulates a thickness of the two-component developer on the developing sleeve;a second magnetic field generator which generates an attracting magnetic field for attracting the carrier particles from the developing sleeve, said second magnetic field generator having a developer guiding surface which is located above an upper side of the developing sleeve in a vicinity of the repulsing magnetic field, and said developer guiding surface having a closer section and a farther section, said farther section being located farther from the developing sleeve than the closer section and being located downstream of the closer section with respect to a conveying direction of the carrier particles, and a strength of the attracting magnetic field at the farther section being stronger than that at the closer section so that the carrier particles are attracted to the closer section and conveyed to the farther section along the developer guiding surface; anda developer conveying member, provided in a vicinity of the farther section of the developer guiding surface, for conveying the removed carrier particles to the developer storing section.