A DEFENDANT’S OWN PATENT MAY NOW BE USED AS EVIDENCE OF NON-INFRINGEMENT
Contrary to popular belief, the fact that company Y patented its own product does not mean that the same product does not infringe the patent of company X. This is because of the nature of the patent grant itself. A patent affords the owner the right to exclude others from making, using, selling, offering to sell or importing the subject matter covered by its claims. The patent grant is not, and has never been, an affirmative right to make, use, or sell that which is covered by the patent claims. The principles at work give rise to the common situation where a later invention Y is patentable over an earlier patented invention X. However, the Y invention cannot be manufactured without a license under the X patent.
Many industries are subject to the effects of unexpired so-called dominant patents obtained by pioneers in the field. In some cases latecomers license their patents on the latest technology they are commercializing in exchange for cross-licenses under earlier dominant patents. This keeps all licensed companies in the market. In addition to preventing unauthorized use of the patented improvements, the patents obtained by latecomers on their improvements may also be valuable in defending against patent infringement suits.
Where a newcomer to a market has carefully designed its competing product to avoid literal infringement of a competitor’s patent, it may nevertheless find itself in protracted, expensive patent infringement litigation trying to prove to a jury of non-technically trained individuals that its product does not infringe the competitor’s patent under the so-called doctrine of equivalents. Recent cases decided by the U.S. Court of Appeals for the Federal Circuit indicate that a patent infringement defendant has a reasonable chance of getting a trial judge to allow a jury to consider the defendant’s own later patent on its accused product as relevant evidence on the issue of whether or not substituted structure in the defendant’s product is substantially similar to elements of the claims of the plaintiff’s earlier patent which are not literally satisfied. The defendant can argue that if the new structure is patentable over the plaintiff’s patent, it must be non-obvious over the same, and therefore substantially different, i.e. non-equivalent. See Zygo Corp. v. Wyko Corp., 38 USPQ2d 1281, 79 F.3d 1563 (Fed. Cir. 1996).