US Patent 8488994 Electrophotography-based additive manufacturing system with transfer-medium service loops

An additive manufacturing system for printing a three-dimensional part using electrophotography, the additive manufacturing system including a rotatable photoconductor component, a development station configured to develop layers of a material on a surface of the rotatable photoconductor component, a rotatable transfer medium configured to receive the developed layers from the surface of the rotatable photoconductor component, and a platen configured to receive the developed layers from the rotatable transfer medium in a layer-by-layer manner. The additive manufacturing system also includes a plurality of service loops configured to move portions of the rotatable transfer medium at different line speeds while maintaining a net rotational rate of full rotations of the rotatable transfer medium at a substantially steady state.