Patent ID: 7426361

Claim:
A developer mixing apparatus, comprising: a housing enclosing a chamber that holds developer; a first ribbon blender disposed within the chamber and elongate along a first longitudinal axis, the first ribbon blender including a first intermediate portion and first marginal portions spaced from each other along the longitudinal axis on either side of the first intermediate portion, the first marginal portions including first elements that, upon rotation about the first longitudinal axis, move developer with a first direction of developer flow along the first longitudinal axis within one of the first marginal portions and an opposite first direction of developer flow along the first longitudinal axis within another of the first marginal portions; a second ribbon blender disposed within the chamber and elongate along a second longitudinal axis and adjacent the first ribbon blender, the second ribbon blender including a second intermediate portion and second marginal portions spaced from each other along the second longitudinal axis on either side of the second intermediate portion, the second marginal portions including second elements that, upon rotation about the second longitudinal axis, move developer with a second direction of developer flow along the second longitudinal axis within one of the second marginal portions and an opposite second direction of developer flow along the second longitudinal axis within another of the second marginal portions; a third ribbon blender disposed within the chamber and elongate along a third longitudinal axis and adjacent at least one of the first ribbon blender and the second ribbon blender; and a fourth ribbon blender disposed within the chamber and elongate along a fourth longitudinal axis and adjacent at least one of the first ribbon blender, the second ribbon blender, and the third ribbon blender.