Electrophotography-based 3D printing with improved layer registration

摘要

An additive manufacturing system includes a transfer belt traveling along a belt path including first and second moveable-position rollers and a plurality of fixed-position rollers. The belt path includes a fixed-velocity portion from the first moveable position roller to the second moveable position roller, and a variable-velocity portion from the second moveable position roller to the first moveable position roller. An electrophotography engine positioned along the fixed-velocity portion deposits a part material layer onto the transfer belt, and an image transfer assembly positioned along the variable-velocity portion transfers the part material layer onto a receiver medium. An image sensing system positioned along the belt path between the second moveable position roller and the image transfer assembly captures an image which is analyzed to determine an in-track registration error, and the positions of the first and second moveable position rollers are adjusted to compensate for the in-track registration error.