Inventorship and co-inventors

US patent inventorship criteria are tricky. However, “conception” of the invention and “intellectual domination” are more important than reduction to practice.

Does your invention involve multiple participants? Who do you list co-inventor, and in what order?”

For academic and scientific papers, there is a common order. Usually the junior person who did most of the work often goes in front. Next the senior professor or principal investigator who may or may not have done much work goes at the end. Other persons go in the middle as co-authors according to usually unwritten criteria. If you make sure that no one is seriously offended, the list doesn’t matter too much.

Many inventors begin their careers by writing academic papers. They think that these same rules apply to patents. Unfortunately, they don’t.

For patents, legal system ties the list of inventors to ownership.  You wouldn’t let a friend put his name on the deed to your house!  Patents are more like property deeds.  So, in the US, the list of patent inventors makes a big difference in terms of who owns the patent.  Patents have their own set of rules.

So what are the rules for inventorship?

The USPTO rules are covered by MPEP 2137.01 INVENTORSHIP.  These rules were worked out through a number of court cases. Thus they are a bit fuzzy and open to interpretation.  At the risk of oversimplification, the main idea is that the inventor is the person who conceived of the invention. The inventor is not necessarily the person (such as a supervisor) who suggested working on the problem. The inventor is also not necessarily the person who did the hands-on work to reduce the invention to practice. In fact, reduction to practice is usually not necessary.

Other considerations, such as the issue of “intellectual domination”, are also important. Are you “intellectually dominating” your invention? You may still be able to use suggestions from others without making them co-inventors.

Things can get tricky. Sometimes the supervisor’s suggestion is really the key insight behind an invention,  making the supervisor an inventor. Similarly, sometimes the person reducing the invention to practice ends up solving unexpected problems, and these solutions form a key part of the invention, making the “technician” an inventor.  Here looking at the invention’s claims can help sort things out.  Who was responsible for what?  Note, however, that claims can change during the examination, and sometimes an inventor can end up being added to an invention, or left on the “cutting room floor” as a result.

The Pannu factor test

On May 2, 2023, the Federal Circuit further clarified that the following test, called the Pannu factor test, is important. As the Federal Circuit put it, a joint inventor:

  • (1) contributed in some significant manner to the conception of the invention;
  • (2) made a contribution to the claimed invention that is not insignificant in quality, when that contribution is measured against the dimension of the full invention; and
  • (3) did more than merely explain to the real inventors well-known concepts and/or the current state of the art.

In any event, the best time to consider these issues is in advance of filing.  It is also important to discuss assignment in advance of filing as well since the usual goal (to satisfy due diligence) is to have 100% of the invention assigned to the same persons or organizations.

Illustration: Participants: RRZE (CC BY-SA 3.0) license