Goodwin Procter attorneys helped to make new law in the U.S. Court of Appeals for the Federal Circuit for our client IBM in Williamson v. Citrix Online LLC, et al. Legal commentators and scholars in the blogosphere have already noted that the decision will have a significant impact on the interpretation of computer software patents.
By way of background, most patent claims recite specific structural elements. However, elements in a patent claim may recite “a means or step for performing a specified function without the recital of structure, material, or acts.” When computer software is claimed as a “means-plus-function” element, the Federal Circuit has stated that the patent must disclose an algorithm for performing the claimed function.
IBM and a number of other companies were sued for infringement of a patent allegedly directed to web-conferencing software. The patent claim recites “a distributed learning control module” for performing certain functions. The issue in the case was whether the claimed “module” was a “means-plus-function” element such that disclosure of an algorithm for performing the claimed functions was required.
The Federal Circuit sitting en banc affirmed the district court’s holding that the “distributed learning control module” was a “means-plus-function” element. The en banc Court noted that in prior cases it had ruled that the lack of the term “means” in a claim element created a presumption that the element was not a “means-plus-function” element. The Court discussed the evolution of the presumption flowing from the absence of the term “means,” noting that a number of cases referred to the presumption as a “strong one that is not readily overcome” and subsequent decisions “raised the bar even further, declaring that ‘[w]hen the claim drafter has not … us[ed] the term means, we are unwilling to [read the claim element as a “means-plus-function” element] without a showing that the [element] is devoid of anything that can be construed as structure’.”
The Court overruled this body of law, stating:
Our consideration of this case has led us to conclude that such a heightened burden is unjustified and that we should abandon characterizing as “strong” the presumption that a limitation lacking the word “means” is not subject to § 112, para. 6. That characterization is unwarranted, is uncertain in meaning and application, and has the inappropriate practical effect of placing a thumb on what should otherwise be a balanced analytical scale. It has shifted the balance struck by Congress … and has resulted in a proliferation of functional claiming untethered to … and free of the strictures set forth in the statute. Henceforth, we will apply the presumption … without requiring any heightened evidentiary showing and expressly overrule the characterization of that presumption as “strong.” We also overrule the strict requirement of “a showing that the limitation essentially is devoid of anything that can be construed as structure.” The standard is whether the words of the claim are understood by persons of ordinary skill in the art to have a sufficiently definite meaning as the name for structure. When a claim term lacks the word “means,” the presumption can be overcome … if the challenger demonstrates that the claim term fails to “recite sufficiently definite structure” or else recites “function without reciting sufficient structure for performing that function.”
Based on this change in the law, the en banc Court held the claims invalid because the patent specification lacked disclosure of an algorithm to perform the claimed functions. The case now will go back to the district court for further proceedings on claims unaffected by the en banc ruling.