Standing To Sue

In the past, substantially the only way to assert patent invalidity was for a defendant to raise the issue as a counterclaim or defense to an infringement action, or for a competitor in apprehension of pending litigation to bring a declaratory judgment action (DJA). The one exception was a so-called Walker Process claim wherein a competitor has standing to bring suit under the antitrust laws alleging that a patent was procured by fraudulent conduct . There, standing in the consumer is justified because the harm is not the invalid patent, but the use of the invalid patent to establish a monopoly. As of May 2006, that situation has changed. The District Court of D.C. held that a consumer (who is not a competitor) also has standing to bring an antitrust claim for asserting patent invalidity. The court distinguished prior case law by insisting that the consumer be a direct purchaser.

The law has also been clarified recently with respect to parties holding less than a full assignment. In the past the patentee retained standing to sue for patent infringement where the rights had merely been licensed to another, or indeed the transfer was for anything less than "all substantial ownership rights". In a 2006 case the Federal Circuit has now decided that an exclusive license for a limited period is sufficient to convey standing to sue without joining the patent holder. In opinion the Court appears to have been persuaded by the fact that the transfer was: (a) for exclusive right to make, use, and sell; (b) included the right to sue for infringement; and (c) included an unfettered right to sublicense.