Implied Patent Licenses Within Patent Families: Key Case Law Considerations

When a patent owner grants a license to one patent in a patent family, questions often arise regarding whether that license extends by implication to other related patents. The doctrine of implied license plays a crucial role in resolving such questions, especially when the licensed and unlicensed patents share a close relationship in subject matter or priority claims.

The Federal Circuit addressed this issue in TransCore, LP v. Electronic Transaction Consultants Corp., 563 F.3d 1271 (Fed. Cir. 2009). In TransCore, the court held that a patent owner, upon granting a patent license for valuable consideration, cannot take subsequent action to derogate or detract from that right.  Id at 1279.  As such, under certain circumstances, granting an express license to one patent can result in an implied license to related patents within the same family. For example, if the licensed patent and the unlicensed patent are so closely related that practicing the licensed patent would necessarily infringe the unlicensed one, an implied license may arise. 

Further clarification came in General Protecht Group, Inc. v. Leviton Manufacturing Co., 651 F.3d 1355 (Fed. Cir. 2011) in which the court explained that the existence of an implied license under the above facts is generally a rebuttable presumption. The parties to a license agreement can attempt to overcome the presumption, but such negation will only be effective if there is a clear indication of mutual intent to exclude an implied license. Vague or ambiguous language will not suffice; the agreement must explicitly show that the parties intended to avoid extending the license to other patents in the family.

In summary, when a license is granted to a patent within a family, courts may presume an implied license to closely related patents absent a clear, mutual agreement to the contrary. Both licensors and licensees should carefully draft license agreements to explicitly address the scope of the license, ensuring that their intentions regarding implied licenses are unambiguously stated.