Oral argument was heard in February in Phillips v. AWH Corp., a case which will decide what role dictionaries play in determining the meaning of words included in patent claims.
Patent claims define what the patent covers or what the inventor may exclude others from doing. To infringe a patent, the infringer's product or activity must fall within the scope of a valid patent claim and not just within the description of the invention set forth in other portions of the patent. Therefore, key to every patent infringement case is determining the meaning of terms used in the claims.
For years, the United States Court of Appeals for the Federal Circuit indicated that patent claims should be construed primarily by reference to so-called intrinsic evidence. That includes claims and specifications, as well as prosecution history, which is the record made during the application process. Only when an ambiguity remains should the court consider other extrinsic evidence, such as dictionaries, treatises and expert testimony.
More recently, the court has provided conflicting direction on the proper procedure for claims construction, indicating at times that dictionary definitions should be consulted first to establish the ordinary meaning of claim terms, which should be adopted unless the patent specification clearly states otherwise.
Last July, the Federal Circuit decided to reconsider its prior ruling in Phillips and requested additional briefing from the parties and friends of the court (amicus curiae) regarding the proper judicial procedures for claim construction.
Groups submitting amicus briefs included patent lawyer associations, law professors, consumer groups and companies such as Visa, IBM and Novartis. The overwhelming consensus of the 33 amicus briefs is that claim terms should be interpreted by looking primarily at how the terms are used in the claims, specification and prosecution history, and only secondarily at dictionaries and other extrinsic evidence.
The majority also favor allowing expert testimony to play some role in claim construction and giving some deference to the trial court's claim construction, particularly where the court made factual determinations.
There was little agreement on whether general purpose or technical dictionaries should be given more weight and whether dictionary definitions should be applied narrowly or broadly.
Using all published dictionary meanings would be consistent with the U.S. Patent Office's policy of giving the broadest reasonable construction to patent claims. However, this approach could be costly and time-consuming. There are almost 73,000 versions of English language dictionaries, and the Federal Circuit itself has resorted to using 24 dictionaries over the past nine years.
Others argued that importing broad dictionary meanings to claim terms often results in unfairly granting artificially broad patent claims that well exceed the scope of anything the patent applicant invented. These parties favor narrowing dictionary meanings to only those consistent with the specification, or to apply only the narrowest meaning.
Claim interpretation often hinges on seemingly insignificant words. In a recent case involving three major food conglomerates and a pet food product, the key issue was whether the word "ingredients" in the patent claims included only the starting materials or also the end components of the finished product. The Federal Circuit used dictionary definitions to conclude the word included the end components even though the specification of the patent appeared to use the term to refer to only starting materials.
A decision in Phillips is not expected until early 2006. In the meantime, a patent applicant could specifically define each claim term but by doing so would forfeit the right to later claim a broader definition should apply. Short of this, the applicant could identify pertinent references that should be resorted to for claims interpretation.
Both technical references as well as general dictionaries should be checked to ensure that the definitions of each term chosen have the intended meaning. Finally, other time-honored methods designed to secure valid patent protection with sufficient scope to protect the invention from future infringement should also be employed.
Roberta R. Wilson is counsel in the Pittsburgh office of Buchanan Ingersoll PC and is a member of the firm's Intellectual Property Section. Her IP experience includes such issues as patents, trademarks, Internet, domain names and copyright and trade secret matters. Reach her at (412) 562-8396 or firstname.lastname@example.org.