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AssigneePowdertech Co., Ltd.
InventorsHiromichi Kobayashi, Toru Iwata, Toshio Honjo
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It is contemplated to provide irregular shaped ferrite carrier which has a lower resistance, a high specific surface area, a low specific gravity and a longer operational life, and an electrophotographic developer comprising the ferrite carrier which prevents the toner scattering, has a high image density, and is responsive to high-speed and color imaging. The irregular shaped ferrite carrier is characterized in that the carrier particles are irregular shaped, and 40 percent by number or more of the particles have a rock candy sugar shape and/or an oyster shell shape, and that the shape factor (SF-1=R2/S×π/4×100, wherein R is a maximum length and S is a projected area.) is 140 to 250, and the distribution width (δ) is 60 or less.
An irregular shaped ferrite carrier, comprising carrier particles which are irregular shaped and said carrier has a shape factor (SF-1), represented by the below expression, from 140 to 250 and a distribution width (δ) of 45 to 60, and wherein 49 to 79 percent of the carrier particles have a shape factor (SF-1) of greater than 140,
Dependencies are inferred from the claim text.