Surprise! Legal wrangling hinges around dictionary definition
Despite all the expertise, years of waiting, reams of paperwork, and thousands of dollars that bring patents to fruition, a patents value may actually hinge on a definition in a dictionary that those who worked on it never considered. Why? Because the value of a patent depends on the patent's "claims." The bulk of a patent is comprised of drawings and written description that details the invention. A section that appears at the end of a patent called the "claims" define a patent's scope of protection. The "claims" use very specific language to set the specific bounds of the invention. A patent's claims are somewhat analogous to a deed of real estate. Just as a deed defines the metes and bounds of real property, it is the claims that define the metes and bounds of your intellectual property. Therefore, it is critical to understand that the value of your patent relies on the words you choose to describe your technology in the claims, perhaps even more than the technology itself. It is because of this fact that much of the legal wrangling that occurs in obtaining a patent or in a patent infringement litigation revolve around the definition of a few critical words. So how do you determine what the language of the patent's claims mean? For years, this has been an elusive question with mercurial answers. Before 1996, the question of what a claim meant was an issue for the jury to decide. Juries are traditionally non-tech savvy. In 1996 in the case of "Markman vs. Westview Instruments Inc.," the U.S. Supreme Court ruled that it was the job of judges to perform claim interpretation and to instruct the jury on what the claims of a patent mean. As a result of the Markman case, a new procedure, known as a Markman hearing, has become a standard part of a patent infringement suit. At this hearing, each side presents to the judge what it believes the words of the claims mean. The judge resolves all disputes and then issues a ruling on how the claims are to be construed. That ruling is used as part of the instructions to the jury. Consequently, the process of construing the meaning of the language of a claim, or "claim construction" in the jargon of patent litigation, is critical in determining the worth of your patent. Since then, the Court of Appeals for the Federal Circuit, the appeals court with exclusive jurisdiction for patent matters, has been refining the methodology by which patent claims are construed. In several recent cases, including "Texas Digital Systems Inc. vs. Telegenix," the Federal Circuit has elaborated guidelines for performing the Markman process and construing claims. Overall, the goal of any claim construction is to avoid reading the meaning of the claims too broadly or too narrowly, and to reach an appropriate understanding of the terms in light of the public record of the patent. This record includes the patent itself as well as the patent prosecution history (the back and forth communications between the patent applicant and the Patent Office). The Federal Circuit has stated that dictionary and technical treatises, publicly available at the time the patent issues, are further objective resources that establish meanings to words that would have been attributed to the words of the claims by those of skill in the art. These references are unbiased, unlike expert testimony that is typically colored by the motives of parties in litigation. It may seem logical that the patent's specification and the patent's prosecution history would be the best place to start the investigation into the claims' meaning. However, the Texas Digital case points out that starting the investigation with intrinsic evidence runs a substantial risk that the words of the claims will be limited to just what is shown in the patent's examples and be read too narrowly. Thus, the primary rule is that there is a heaving presumption that the words of a claim are given their ordinary meaning, which is determined by a dictionary. Only after the ordinary meaning of the words are determined are the patent specification and prosecution examined. This insures that the words of claims are not unduly limited to the specific examples disclosed in the patent specification. The patent specification and prosecution history are examined to determine if the patent inventor used the words in a way that is inconsistent with the ordinary meaning of the words, thus overcoming the heavy presumption. The inconsistent usage of a word can be shown in several ways. For example, the heavy presumption may be overcome if the patent inventor chooses to be his or her own "lexicographer," by expressly giving certain words a special meaning. This can be evidenced in either the patent specification or patent prosecution. Further, a clear and manifest statement made by the patent inventor during the prosecution of the patent that disavowed or disclaimed the scope of a claim can overcome the heavy presumption that a word in a claim is to be given its ordinary meaning. Of course depending on their goals, one party will be motivated to seek a broad reading of certain terms, and the other will be motivated to seek a more narrow reading. A patent owner will usually be seeking a broad reading of the claims in order to cover a competitor's device, thus making it easier for the patent owner to prove infringement. Conversely, a competitor may seek a narrow reading to avoid infringement. These extremes are tempered by the fact that a broad reading may render the patent invalid based on previous technology. A judge is saddled with the responsibility of parsing the arguments and evidence produced by both parties at the Markman hearing and rendering an appropriate claim construction. Following the approach in the Texas Digital case, the Federal Circuit used a 1984 edition of one dictionary to interpret some of the words of Texas Digital's claims and a 1985 edition of another dictionary to interpret other words. Based in part on these dictionary definitions, the Federal Circuit found that the trial judge had misinterpreted some claims of Texas Digital's four patents. The Federal Circuit thus overturned $15 million dollars in damages awarded to Texas Digital and sent the case back to the trial court with instructions to try the case again using a proper claim construction. As you can see, dictionaries made a big difference to the fortunes of Texas Digital, and its adversary, Telegenix. For the rest of us, the law their case created provides a simple, step-by-step procedure that many judges, lawyers and technologists should find helpful in answering the question of how to construe a patent's claims. This law applies to every patent, whether attained after or before the Texas Digital decision. Therefore, businesses should ensure that the patents they have or are seeking, or patents that their competitors have are properly evaluated in light of this case.
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