The purpose of this work is to introduce the manager and technologist, the student, and the foreign patent practitioner to the United States Law of Patent Infringement. It should also be a refresher to those patent agents or attorneys who devote their time exclusively to prosecution rather than to litigation. But it should be mentioned that the highly respected Judge Hand, in 1950, noted, ". . . when the question is whether there is a patentable invention. The issue is as fugitive, impalpable, wayward, and vague a phantom as exists in the whole paraphernalia of legal concepts"--indicating the difficulty in determining when an invention is a patentable one.
Effort has been made to illustrate the development of that law from its historical perspective to the recent decisions of the Court of Appeals for the Federal Circuit (CAFC), the premier patent appellate tribunal. Creation of the CAFC in 1982 was a landmark in the evolution of patent law and policy. With the withdrawal of patent jurisdiction from the twelve regional Courts of Appeal, the CAFC is the court with primary responsibility for interpreting and developing the rules and principles of patent law.
Particular emphasis is placed on the large number of recent opinions on the question of equivalents in an infringement context. Many practitioners feel that several of the opinions in the 1987-1994 period are revolutionizing the scope of claims that define the invention in the means-plus- function format. It would appear that the battle in the courts, and within the CAFC itself, over the essence of the infringement analysis (i.e., the interpretation and construction of claims with the subsequent application to the accused device) has finally peaked, although many problems remain.