Inventorship is on a Claim by Claim Basis
On occasion, it is helpful to revisit patent basics. How do we know whom to name as an inventor? 35 U.S.C. 116 states that when “an invention is made by two or more persons jointly, they shall apply for patent jointly and each make the required oath.” This statute further states that inventors may apply for a patent jointly even though
(1) they did not physically work together or at the same time,
(2) each did not make the same type or amount of contribution, or
(3) each did not make a contribution to the subject matter of every claim of the patent. (emphasis added)
It is possible that different claims of an application or patent may have different dates of inventions even though the patent covers only one independent and distinct invention within the meaning of 35 U.S.C. 121. When necessary, the U.S. Patent and Trademark Office or a court may inquire of the patent applicant or owner concerning the inventors and the invention dates for the subject matter of the various claims.
For joint inventors, 37 C.F.R. 1.45(c) states that if “multiple inventors are named in a nonprovisional [patent] application, each named inventor must have made a contribution, individually or jointly, to the subject matter of at least one claim of the application and the application will be considered to be a joint application under 35 U.S.C. 116.”
Therefore, it is handy to have each of the inventors associate his or hername with each of the claims that he or she believes reflects his or her contribution to the invention. One method for recording this type of information is to create a two-column claim chart with an entire claim or claim phrase on one side, and a space for one or more inventor names on the other. Then, many months after filing the application, it is easy to make a determination regarding dropping an inventor when claims are amended during prosecution.