Patent Claims More Vulnerable To Invalidity Attacks After Supreme Court Holds Standard For Determining Definiteness Of Claim Language To Be Amorphous And Indefinite

On the same day, to study ways of improving patent claim clarity, the USPTO launches glossary pilot program offering expedited processing for software patent applications.

While claims are recognized as being the most important part of the modern patent document, the scope of the rights secured by a patent was decided by U.S. courts in eighteenth and early nineteenth century infringement actions by way of a comparison of the accused product or process with the entire specification of the patent, rather than only the claims.1 As one commenter has observed, "the courts for a long time did not regard [the claims] as the definitive measure of the scope of the patent" but rather looked to "the whole patent document, including the claims as a guide...to ascertain the scope and nature of the invention."2

Beginning in the latter half of the nineteenth century, however, courts increasingly relied on claims to determine the legal boundaries of a patented invention.3 The impetus for this shift was the statutory requirement, added by the Patent Act of 1836, that every patent applicant must "particularly specify and point out the part, improvement, or combination, which he claims as his own invention or discovery."4 Claims are now considered to be the essence of the patent right - they are "the portion of the patent document that defines the patentee's rights."5

The statutory claiming requirement was modified by the Patent Act of 1870 to specifically add the phrase "distinctly claim" to the statute, and this formal requirement for defining the invention is preserved in 35 USC §112 of current law.6 Although the disclosure in the patent specification is regularly relied upon to aid in interpreting claim language, the "definiteness" requirement of §112 is essentially a question of whether the language of the claims defines the invention in a manner that is clear and unambiguous to a hypothetical person possessing an ordinary level of skill in the pertinent art. In Merrill, the principal policy objective for the increased importance afforded to the claims was articulated as being the necessity for highly precise public notice of the patentee's rights, as claims are intended to clearly demarcate what the invention is and what is left free to the public to use. In this sense, claims are often compared to the "metes and bounds" of a real property deed - indefinite claims, by analogy, fail to inform passersby whether they are trespassing or not.

Acknowledging the patent system's public notice function, a unanimous Supreme Court, in Nautilus Inc. v. Biosig Instruments, Inc., lowered the threshold for invalidating patent claims for indefiniteness by adopting a new legal standard for determining whether a claim is indefinite and casting away a standard that had been consistently employed by the Federal Circuit.

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