by Dennis Crouch
Back in March 2022, I wrote an essay on the spectrum of structural and functional claiming, particularly commenting on the Federal Circuit’s decisions in Dyfan, LLC v. Target Corp., 28 F.4th 1360 (Fed. Cir. 2022) and VDPP LLC v. Vizio, Inc., 2021-2040, 2022 WL 885771 (Fed. Cir. Mar. 25, 2022). See, Dennis Crouch, Discerning the Purpose and Means of Williamson v. Citrix, Patently-O (March 30, 2022).
A basic question in these cases is whether the claim elements at issue recite sufficient “structure” to avoid being classified as a “means” claim under 35 U.S.C. 112(f). Patentee’s typically prefer to avoid 112(f) classification as the result is typically either (1) narrow claim scope or (2) invalid claims. The classification is seemingly easy when a patentee uses classic “means plus function” (MPF) claim language without reciting specific structure, but patentees usually avoid that approach in favor of quasi-structural elements such as a “module,” “circuit,” or “system.” Prior to Williamson, the Federal Circuit strongly presumed claim elements lacking traditional MPF language were not MPF elements. Williamson eliminated that strong presumption in favor of a weak rebuttable presumption that can be overcome with a demonstration “that the claim term fails to recite sufficiently definite structure or else recites function without reciting sufficient structure for performing that function. Williamson v. Citrix Online, LLC, 792 F.3d 1339 (Fed. Cir. 2015) (en banc as to Part II.C.1). That case went on to focus attention on “nonce words” such as “mechanism,” “element,” and “device” that “typically” fail to recite sufficiently definite structure. The problem here is discerning in any particular case what level of structure is sufficient. Although the court used the word “definite”, it seems unlikely that they intended to tie the 112(f) here to the same reasonable certainty test used for 112(b).
In the recent cases of Dyfan and VDPP, the Federal Circuit pushed-back a bit on an expansive interpretation of Williamson. In Dyfan, the court considered a wherein clause requiring certain actions and concluded it was implicitly tied to claimed “code” and therefore recited sufficient structure to avoid MPF designation. In VDPP, the court indicated that the nonce word designation should be based upon “evidence that a person of ordinary skill would not have understood the limitations to recite sufficiently definite structure.” The district court in VDPP had not required submission of “evidence” but rather had summarily concluded that the “processor” and “storage” elements were nonce words lacking structure. On appeal, the Federal Circuit reversed — holding that those words provided sufficiently definite structure.
Now, the accused infringers in both of these cases have petitioned for rehearing: calling for either (1) panel rehearing or (2) rehearing en banc. The court has not yet requested responses in either case. (No response may be filed to a petition for panel or en banc rehearing unless the court orders a response).
In Dyfan, Target argues that the law was settled by Williamson v. Citrix Online, LLC, 792 F.3d 1339 (Fed. Cir. 2015) (en banc as to Part II.C.1) and confirmed in Egenera, Inc. v. Cisco Sys., 972 F.3d 1367 (Fed. Cir. 2020). The petition asks the following questions:
- For claims that recite computer software for performing functions, what
are the criteria for determining whether software-implemented functional claim
language is subject to 112(6)?
- Can the Court ignore parts of the recited software-implemented function, or ignore such function entirely, in making the determination as to whether the claim recites sufficiently definite structure?
- If no, and if the software-implemented function cannot be performed by a general-purpose computer without special programming can 112(6) be avoided by claiming a general-purpose computer term (such as code or program or processor) and a software-implemented result, if a person of ordinary skill in the art would understand how to write a program to achieve this result; or is the claim required to recite an algorithm to achieve the software-implemented result to avoid the application of 112(6)?
As you can see, the focus of the questions tie the case to to general-purpose computers and software-implemented inventions, and thus implicitly raises overlay questions of subject matter eligibility. A group of law professor led by Mark Lemley have also filed an amicus brief in support of rehearing in Dyfan.
There is a reason Congress limited functional claiming in 1952. And that reason applies with particular force in the software industry. Many of the problems with abuse of software patents can be traced to the fact that we historically allowed patentees to claim functions, not implementations. It is broad functional claiming that leads to assertions that every part of a complex technology product is patented, often by many different people at the same time. It is broad functional claiming that puts stars in the eyes of patent plaintiffs, who can demand huge royalties on the theory that there simply is no other way to implement the technology they have patented. And it is broad functional claiming that makes most of the resulting patents invalid, since even if ten programmers developed ten different algorithms to solve a problem only one of them could be the first to solve the problem at all.
Williamson reined in those abuses by setting a clear rule: patentees can’t avoid section 112(f) simply by picking a magic word other than “means.” The panel opinion directly contradicts Williamson. This Court should grant en banc rehearing to resolve the conflict
In VDPP, the defendant (Vizio) asks the following questions in its petition:
- May a claim term that connotes structure to one of skill in the art nonetheless require means-plus-function treatment because the structure it connotes is not sufficient for performing the functions the structure is recited as performing
- Must the proponent of means-plus-function treatment of a claim term that does not include the word “means” adduce extrinsic or other evidence beyond the language of the claim itself, in order to meet its burden of production in rebutting the Williamson presumption—or may the proponent satisfy its burden by showing that on its face, the claim does not recite sufficient structure?
- May the algorithmic-disclosure requirement that this Court has erected as a bulwark against purely functional claiming for computer-implemented inventions be evaded by reciting in a claim, rather than the specification, a generic “processor adapted to” perform claimed functions?
What is missing here:
- The court decisions lack some clarity as to what it means to “recite sufficiently definite structure.” Is this linked to the definiteness test of 112(b)?
- It is unclear what “evidence” is required for a court to overcome the presumption — in particular, must a court always look outside the patent document itself?
- How should all this be handled by the USPTO during ordinary prosecution?