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. 26, 1994
Filed:
Jan. 06, 1992
Tadashi Nakamura, Nara, JP;
Shougo Iwai, Yamatokoriyama, JP;
Sharp Kabushiki Kaisha, Osaka, JP;
Abstract
A toner for use in electrophotography in accordance with the present invention comprises toner particles and an external additive that is constituted by a silica fine powder composed of inexpensive silica particles coated with a mixture of homogeneously distributed tin oxide and antimony, and that is attached to the surface of the toner particles. The use of the silica fine powder improves the flowability of the toner whereby images with a uniform density can be obtained. In addition, the toner is stabilized as the above mixture lowers the electric resistance on the surface of the toner particles. The above external additive may also be composed of aluminum oxide fine powder or cerium oxide fine powder. For instance, with a toner for use in electrophotography that comprises an external additive composed of cerium oxide fine powder, the surface of the photoreceptor is polished though the polishing action of the cerium oxide whereby the formation of a toner film on the photoreceptor can be prevented and clear images can be obtained.