By Ronald Slusky
Ronald Slusky mentored dozens of attorneys in “old school” invention analysis and claiming principles over a 31-year career at Bell Laboratories. He is now in private practice in New York City. This article is adapted from his book “Invention Analysis and Claiming: A Patent Lawyer’s Guide” published by the American Bar Association and available at all online bookstores. More information about the book can be found at www.claim-drafting.com. Ron can be reached at 212-246-4546 and firstname.lastname@example.org
A patent’s enforcement is fraught with uncertainty. Claims may contain unappreciated loopholes—unnecessary elements, unduly narrow terminology or limitations whose meaning seemed perfectly clear “at the time” but could be argued to be indefinite. Another uncertainty is the discovery of prior art not cited during prosecution.
These problems may not surface until the patent owner attempts to license or sue on the patent, at which point it is usually too late to do to much about them. Fallback feature claims2 and definition claims3 can take us part of the way toward addressing these uncertainties, but it is difficult to anticipate every possible invalidity...