Joint ownership can arise from joint inventorship, such as where two or more individuals directly or indirectly collaborate as inventors. This often times happens unwittingly, as the two inventors may not have worked on the development of the invention together or at the same time. Sometimes, the primary inventor does not realize that the other inventor’s contribution raises that individual to the level of inventor. This is because the inventors do not have to make the same type or amount of contribution and the inventors do not have to contribute to every claim in the patent application.

Ethicon was the exclusive licensee of the “sole” inventor of the patent and Ethicon sued U.S. Surgical for infringement. U.S. Surgical investigated and located a “missing” (ie. unnamed) joint inventor and then proceeded to negotiate a license from him. Ethicon challenged the validity of the license. The courts upheld the validity of the license because the “missing” inventor, as a joint inventor, was a joint owner of the entire patent. Ethicon v. U.S. Surgical Corp., 135 F.3d 1456 (Fed. Cir. 1998), cert. denied, 525 U.S. 923 (1998).

The cautionary tale here is that even a one percent contributor to a patent will be a joint owner of the entire patent. An owner of a patent who believes that he has exclusive control of the patent may be sadly mistaken and find himself suddenly competing with another company.

The key for the “sole” inventor is to make sure that all others (ie. employees, etc.) who may work on any aspect of the invention have valid employement agreements or valid joint venture agreements that contain the proper assignment clauses. These agreements must be entered into prior to any work by the employee or contractor.

For the purchaser of a patent, proper due diligence will be key to understanding where the potential risks may arise. Due diligence should include review of agreements with employees or contractors working on the development of the intellectual property. Drafting strong purchase agreements and transaction documents can help protect the purchaser. Effective guarantees, warranties, indemnification and assignment clauses can lessen the financial impact, if something unpleasant occurs following the purchase of the intellectual property.