Increasingly, inventions derive from collaboration between researchers at two or more organizations, and researchers are moving from one employer to another. Recent decisions highlight the importance of careful inventorship determinations when a patent application is first prepared and during its prosecution. Patent inventorship and ownership are distinct, but related issues. Under U.S. law, patent rights are initially owned by the inventors, who may individually assign ownership to others. Thus, correctly determining inventorship is essential for ensuring an accurate understanding of patent ownership rights and avoiding unnecessary litigation. Inventorship can also affect what prior art applies to a given invention.

Who is an inventor?

Under U.S. law, a patent application must be made in the name of the natural people (i.e., not a juridical entity) who are the actual inventors. The patent law provides that "when an invention is made by two or more persons jointly, they shall apply for a patent jointly..." (35 U.S.C. § 116). In the modern era of collaborative research, many patent applications are filed with joint inventors.

Inventorship is independently determined for each claim of a patent. The inventorship of the patent as a whole includes all the inventors of the claims of the patent as issued. Thus, the inventorship of a patent application can change throughout prosecution as claims are added, amended, and canceled, until the claims are allowed. The U.S. Patent and Trademark Office encourages changing the designated inventors as appropriate during prosecution. Nevertheless, those pursuing a patent often determine inventorship with respect to the claims as filed, without reevaluating the inventorship as the claims evolve. As a result, it is easy for patents to issue with incorrect inventorship. Such oversights generally do not threaten the enforceability of a patent, however, because as long as the inventorship issues arose without deceptive intent, inventorship may be corrected after patent issuance.

Who, then, of the many who may contribute to a research project, qualifies as an inventor? Conception of the invention is the key.

Conception is the mother of invention

The courts are clear that a claimed invention's inventors are those who conceived the invention delimited by the claim (e.g. Burroughs Wellcome Co. v. Barr Laboratories Inc., 32 USPQ2d 1915 (Fed. Cir. 1994)). Moreover, inventorship is determined when conception is complete, in that all of the claimed features are present. Thus, in determining inventorship, a useful starting point is to identify the time when conception was complete and who was involved in the research and development effort at that time.

However, while the standard of inventorship may be easy to state, actually determining inventorship can be difficult. Subtle, and sometimes conflicting, aspects of different court rulings; the need to consider numerous facts documented with varying accuracy and completeness; and the often divergent interests of parties can significantly complicate a determination of inventorship. Often, the inventorship determination is best approached by first determining who is not an inventor. For instance:

  • A person whose contribution is not reflected in the complete conception of a claimed embodiment, for example, because their involvement was too early, is not an inventor of that claim. In one case, faculty at Florida State University working on one set of pharmaceutical compounds were found to be not inventors of slightly different compounds later developed by a former colleague who had gone to work for a private company. (Board of Education ex rel. Board of Trustees of Florida State University v. American Bioscience Inc., 67 USPQ2d 1252 (Fed. Cir. 2003))
  • A person who contributes only to the reduction to practice of an invention is not an inventor. For example, when the conception of an invention is already complete before a person contributes to an endeavor, that person is not an inventor. In the Burroughs Wellcome case, a patent application was prepared before Dr. Broder, an NIH scientist, contributed to research on the use of AZT to treat HIV/AIDS, and so he was not an inventor.
  • A person who does not collaborate, in some fashion, in the conception is not a joint inventor. There must be some open line of communication between people for them to be considered joint inventors. (Kimberly-Clark Corp. v. The Procter & Gamble Distributing Co. Inc., 23 USPQ2d 1921 (Fed. Cir. 1992)) Contemporaneous and independent development does not constitute joint inventorship. Thus, two individuals who arrived at the same idea independently cannot later "agree" to be listed as joint inventors.
  • A person who merely supplies background information data or general scientific knowledge to an inventor without making a specific contribution to the complete and workable conception of an invention is not a joint inventor.

Determining Inventorship – When to do it.

As the above discussion makes clear, inventorship must be determined on a case-by-case basis and is highly fact dependent. Therefore, a good approach is to determine inventorship when a patent application is prepared and filed, when claims are substantially modified during prosecution, and when claims are allowed. Early evaluation of inventorship should involve gathering facts concerning the history of a project, for example through brief interviews when events are still fresh in the minds of the relevant people, and, if necessary, through the collection of corroborative evidence, such as notebooks and written (often electronic) communications. Early and accurate determination of inventorship and the timely reevaluation thereof enables appropriate business planning and can avoid or mitigate situations where ownership rights might be questioned, or worse, eliminated by a court decision.

When the inventorship is unclear, it is important to seek the advice of counsel. There are many nuances and gray areas. A putative inventor may be included out of an abundance of caution, but this should only occur when there is substantial uncertainty. In instances where an individual appears not to be a joint inventor, and is therefore not included, it is prudent to ensure that they are under an obligation to assign their rights to the company or institution. If that person is later added as an inventor, then the ownership will not change.