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:
Oct. 14, 2008
Filed:
Jul. 18, 2005
Hyun-wook Bae, Yongin-si, KR;
Hyun-wook Bae, Yongin-si, KR;
Samsung Electronics Co., Ltd., Suwon-si, Gyeonggi-do, KR;
Abstract
Provided is an electrophotographic developing agent including: toner particles including a binder resin, a colorant, and a charge control agent; and an external additive added to the surface of the toner particles, wherein the external additive includes at least one inorganic particulate component and at least two types of strontium titanate particulate component having different mean primary particle diameters. Typically, the inorganic particulate component is not strontium titanate. Also, an electrophotographic image forming apparatus using the electrophotographic developing agent is provided. The strontium titanate particulate component having different mean primary particle diameters are used as an external additive to maintain uniform charging characteristics and to prevent fog in a non-image area, thereby obtaining good image quality. In addition, the external additives prevent deposition of the developing agent on a developing agent regulating blade due to stress when the developing agent is used for a long time.