Chapter §15.01 The Central Role of Patent Claims

• Jurisdiction: United States

§15.01 The Central Role of Patent Claims

It cannot be overstated that, in patent law, "the name of the game is the claim."¹ This maxim reflects the prominence of claims in patent litigation. Federal Circuit judges observe that "[c]laim construction is the single most important event in the course of a patent litigation."² The manner in which the claims of a patent are interpreted is, in many cases, dispositive of literal infringement. In a smaller but growing number of cases, claim interpretation also may effectively decide whether infringement is found under the doctrine of equivalents.³ Reflecting the centrality and significance of patent claim interpretation, the U.S. Supreme Court in 2014–2015 issued two decisions dealing with the topic.⁴

Chapter 2 of this treatise introduced patent claims, focusing on the drafting of claims as part of patent procurement and the requirement that claim language be definite under 35 U.S.C. §112(b). The reader is encouraged to review Chapter 2 (in Volume I of this treatise) as important background for this chapter. The remainder of this chapter addresses key aspects of patent claim interpretation as they impact patent enforcement.

The claims are undoubtedly the most important part of a patent. A patent claim is a single-sentence definition of the literal boundary of the patent owner's right to exclude. Acting as a sort of verbal fence, the patent claim is intended to provide reasonably clear notice, in advance of litigation, of just how far the patentee's competitors can proceed in imitating the patented invention without infringing the patent owner's right to exclude.⁵

The patent law professor's classic analogy compares a patent claim with a deed to real property. The deed very specifically defines the boundaries of a plot of land but does not describe what may be located in the interior—buildings, trees, water, and the like. Similarly, a patent claim does not describe the invention to which the patent is directed. Rather, it defines the extent of the patent owner's right to prevent others from exploiting that invention.⁶

The role of describing the patented invention is played not by the patent's claims but rather by its written description and drawings. In accordance with 35 U.S.C. §112(a) (eff. Sept. 16, 2012), these parts of the patent specification must provide an enabling disclosure of how to make and use the invention without undue experimentation and also must disclose the best mode of carrying out the invention...