of the inventor, but should be determined based exclusively on official patent documents references such as treaties and dictionaries.

By separating claim interpretation from factual determinations, the Federal Circuit turned over to district court judges – as opposed to juries – the task of interpreting claim language. Construction of patent claims is often a pivotal aspect to any infringement case, and can make or break an infringement case.

Claim interpretation was thrown into an even greater state of confusion in 2002, when the Federal Circuit decided, in a case called Texas Digital Systems, Inc., that official patent documents ("intrinsic resources") should take a back seat to so-called objective resources like dictionaries, treatises and encyclopedias ("extrinsic resources").

Now, with the Phillips decision, the Federal Circuit has (to quote a dissenting opinion in the case) "whip[ped] the bar into a frenzy," reversing its trend. Under prior cases, a patent claim should be interpreted by first looking to the plain and ordinary meanings set forth in such extrinsic resources, and use intrinsic resources only if it contradicted or disavowed the plain and ordinary dictionary meanings.

While a step in the direction of clarification, the Phillips case may have thrown patent infringement litigation into yet another morass. A key question, not addressed by the Court, was whether the district trial court's determination as to patent claim language meaning should be given any deference on appeal.

By not addressing the issue, the Federal Circuit not only kept itself in business in perpetuity, as litigants will continue to challenge on appeal district court "Markman decisions" as to patent claim interpretation, but it left open the continuing question of exactly what weight should be placed on the use by district court judges of intrinsic versus extrinsic resources.

Ultimately, the dissent may have hit the nail on the head, when it attacked the majority's opinion by stating: "Eloquent words can mask much mischief. The court's opinion today is akin to rearranging the deck chairs on the Titanic – the orchestra is playing as if nothing is amiss, but the ship is still headed for Davy Jones' locker."

Only time will sort this one out, but claim interpretation in patent infringement cases will continue to be problematic, leaving the effort to get it right in the first place paramount, and exposing litigants to great cost to secure proper and beneficial claim construction in infringement litigation.

Frederic Mendelsohn is a partner with the law firm of Burke, Warren, MacKay & Serritella, P.C., in Chicago, www.burkelaw.com. His practice involves complex commercial litigation and dispute resolution; labor and employment law; market channel matters involving dealers, distributors and sales representatives; and the general representation of middle market business. For 12 years he was general manager of the Electronic Distribution Show, and is intimately familiar with the electronic distribution industry. He may be reached at 312-840-7004 or fmendelsohn@burkelaw.com.

Because successful patented products typically involve millions of dollars over the life of their patents, there are, and always will be, constant disputes as to the validity of patents, who owns the rights to certain inventions, and whether another is manufacturing, selling or distributing products that infringe upon another's patent. Patent litigation has exploded over the past 20 years, so much so that a separate court of appeals was established in 1982 for appeals of patent (and certain other) cases – the U.S. Court of Appeals for the Federal Circuit.

In a very recent and long-awaited decision, Phillips v. AWH Corporation, the Federal Circuit Court attempted to clean up years of confusion and inconsistent rulings as to patent interpretation, which is at the heart of what is in a patent. That the Phillips case was decided "en banc" shows its significance.

While the Federal Circuit employs 12 judges (appointed much like Supreme Court Justices), cases are typically decided by a panel of three. The Phillips case, however, was heard by the entire Federal Circuit Bench, with the aid of more than 30 amicus curiae briefs filed by entities not party to the lawsuit to aid the court in gaining the information it needs to make a proper decision, or to urge a particular result on behalf of the public or a private interest of third parties who will be affected by the resolution of the dispute. Among the questions before the Court was to answer was what sources a federal trial court should turn to when construing patent claim language.

As most distributors know, patents are issued by the U.S. Patent and Trademark Office, and essentially are the grant of a property right to the inventor "to exclude others from making, using, offering for sale, or selling" the invention in the United States or "importing" the invention into the United States. What is granted is not the right to make, use, offer for sale, sell or import, but the right to exclude others from making, using, offering for sale, selling or importing the invention. Patents generally last for a term of 20 years from the date on which the application for the patent was filed in the U.S., and are effective only within the U.S. (and its territories and possessions).

Patents have two key components: a "specification" that includes a written description and drawings (if applicable) of the claimed invention, and its "claims." It is a bedrock principle of patent law that "the claims of a patent define the invention to which the patentee is entitled the right to exclude." Claims are simply words set forth in a certain section of an issued patent.

While the specification must describe the invention set forth in the claims, the language of the claims is what the trial courts look at to determine what "the applicant regards as his invention." Unless each element of a patented claim exists in an accused infringing device, there can be no patent infringement.

Thus, determining what the inventor regards as his invention is a significant task, and one which courts are required to make in order to assess infringement. When a patentee asserts patent infringement in litigation, the case is heard before a U.S. District Court. These are trial courts that are found in every state, territory and possession in the United States.

While the topic of patent claim language interpretation seems to be one only an inventor and his lawyer might enjoy, the Phillips case is an important landmark in a long journey for the Federal Circuit, and teaches that the language in a patent application is critical to how a patent grant may ultimately be valued. Like anything else, garbage in typically equals garbage out, and poor claim language can substantially impair the value of a patent. In 1995, in Markman v. Westview Instruments, Inc., the Federal Circuit held that the scope of patent claims should not depend on the facts and circumstances