Triplett v. Lowell

Background

A patent owner sued different companies for infringing several patent claims. In an earlier case in another circuit, some of those claims were held invalid. Months after the Supreme Court denied review, the owner filed written disclaimers (a formal giving up of certain claims) and then sued new defendants in Maryland over the same and other claims. The district court dismissed parts of the suit for inadequate disclaimers, and the Court of Appeals ordered a new trial.

Reasoning

The Court addressed whether an earlier decision that some claims are invalid prevents the owner from suing other defendants on those claims, and whether not filing disclaimers automatically blocks a later suit. The Court held that a prior adverse decision against the owner is not automatically binding in a suit against different defendants. A trial court must decide for itself whether the claims are valid. Only if that court finds the claims invalid does the disclaimer law come into play, and then the court must consider whether the owner unreasonably delayed in filing a disclaimer.

Real world impact

Patent owners can pursue new suits against different defendants without being barred solely because some claims were earlier held invalid. Courts cannot dismiss refiled suits in advance for lack of disclaimer; they must first rule on claim validity. If a court finds invalidity, the timing and adequacy of any disclaimer can still block relief.