A declaratory judgment, in the context of Patent law refers to a lawsuit filed to declare that the inventors patent is invalid. Usually, a declaratory judgment is filed to determine the legal rights of the plaintiff, where the plaintiff is in doubt as to his legal rights. With respect to patents, this is a lawsuit filed by someone against the patent holder asking the court to declare the validity of the inventor’s patent. This lawsuit can also be filed to ask the court to declare that the plaintiff is not infringing the patent. The possibility of such a lawsuit is a concern for poorly financed patent holders who should be careful; otherwise something they do shall be seen as accusing others of infringement and shall require them to defend against a lawsuit often at a distant location and at great expense.