Care must be taken in identifying the actual inventor or inventors, as only the inventor or inventors may sign the oath or declaration and obtain a U.S. patent. Each person who actually
conceived (thought of) claimed subject matter must be listed as one of the inventors. The degree of contribution to claimed subject matter is irrelevant, but it must constitute real invention, not
merely "a pair of hands." The inventors need not have physically worked together, or at the same time, or made the same type or amount of contribution, or each contribute to all claimed subject matter.
MPEP 605 - Applicant MPEP 605.07 - Joint Inventors MPEP 2138.04 - "Conception"