Developing device using magnetic developer
AssigneeCanon Kabushiki Kaisha
InventorsShunji Nakamura, Kozo Arao
Life of this patent
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Abstract
A developing device having a developer holding member provided in confrontation to a latent image bearing member and a doctor blade which feeds magnetic developer onto the developer holding member and regulates a layer thickness of the magnetic developer fed onto the developer holding member, wherein the developer thickness regulating doctor blade is in such a configuration that it may converge magnetic lines of force from the magnetic pole provided on the rear surface of the developer holding member and from the other magnetic pole provided in contiguity to the developer holding member surface opposite to the first-mentioned magnetic pole.
Claims9
A developing device for forming a developed image on an image bearing member, comprising in combination:
- (a) developer holding means having a developer holding surface adapted to oppose the image bearing member;
- (b) means for supplying magnetic developer onto said developer holding surface;
- (c) fixed magnetic field generating means disposed on the side of said developer holding means opposite to said developer holding surface;
- and
- (d) magnetic thickness regulating means disposed on the opposite side of said developer holding means from said magnetic field generating means and within the influence of the magnetic field of a magnetic pole of said magnetic field generating means, said magnetic thickness regulating means being provided with a tip facing said developer holding surface and having a width which is smaller than the width of said magnetic pole of said magnetic field generating means, said magnetic thickness regulating means being opposed to said magnetic pole of said magnetic field generating means across said developer holding means to concentrate the magnetic lines of force extending from said magnetic pole and thereby regulate the developer layer to a thickness smaller than the gap between said magnetic thickness regulating means and said developer holding means.
Dependencies are inferred from the claim text.