Federal Circuit Precedential

Holding:  Infringement by the doctrine of equivalents must be proven using particularized evidence that comes from the perspective of someone skilled in the art.  The standard of evidence required to show infringement by the doctrine of equivalents is not dependent on the complexity of the claimed technology.   

NexStep sued Comcast for infringement of nine patents, including US Pat. No. 8,885,802 and 8,280,009.  The ‘802 Patent is directed to a remote control that receives audio data from a user and sends the data to a console.  The console transcodes the audio data to VoIP and then takes whatever operation was requested by the user.  At claim construction, the district court found the term “VoIP” to be a well-established term of art that requires the transmission of voice conversations, specifically, two-way communication.  This claim construction led to a summary judgment of non-infringement of the ‘802 Patent, as Comcast’s accused device transcoded the audio data to HTTP, which only allows for one-way communication. 

The ’009 Patent is directed to a device that allows a user to access customer support in response to “a single action performed by a user” such as a press of a button or a spoken instruction.  In response to this single action, the device sends identification information for the product, identifies a technical team to solve the issue, and initiates the support session.  NexStep asserted that several of Comcast’s customer service tools infringed the ‘009 Patent. However, each of these customer service tools required a user to press a series of buttons rather than a single button.  NexStep argued that this series of steps, taken together, can be described as a single action.  The ‘009 Patent went to trial, and the jury found the ‘009 Patent to be infringed under the doctrine of equivalents.  However, the district court granted judgment as a matter of law of non-infringement of the ‘009, finding NexStep’s proof of infringement by the doctrine of equivalents to be inadequate.  This decision was upheld by the Federal Circuit.

Infringement by the doctrine of equivalents may be proven in one of two ways.  The first is the function-way-result test which asks if the accused product performs substantially the same function in substantially the same way to get the same result as the claimed invention.  The second method asks whether the differences between the claimed invention and the accused product are insubstantial.  However, the doctrine of equivalents cannot be applied broadly.  Proof must be shown on a limitation-by-limitation basis, not to the invention as a whole. There must be particular evidence that shows what the function, way, and result of both the claimed device and the accused device are and why they are the same.  Evidence must come from the perspective of someone skilled in the art, for example, through the testimony of experts or from technical documents and disclosure of the prior art.  Additionally, the patentee must provide particularized testimony to show equivalence, general testimony showing the overall similarity between the accused product and the claimed invention is not sufficient.

NexStep’s expert did not identify which features of the accused Comcast customer service tools were equivalent to the “single action” claimed in the ‘009 Patent.  He simply referred to “several button presses” on the Comcast customer service tools without further detail.  Nexstep’s expert testimony was also deficient because it did not provide a meaningful explanation as to why the elements from Comcast’s accused customer service tools were equivalent to the claimed limitations in the ‘009 Patent.  Instead, Nexstep’s expert provided conclusory statements that the accused products provide the same function, and failed to describe the way in which the accused product or the claimed limitation operates.  Additionally, his testimony as to the result of the “single action” limitation was too general and failed to track the result required by the claim language.  

NexStep argued that an exception to the requirement of particularized testimony and linking argument for doctrine of equivalents should be made when the technology at issue is easily understandable.  However, the Federal Circuit rejects this argument.  Proving infringement by the doctrine of equivalents has always required particularized testimony and linking argument, no matter the complexity or the simplicity of the technology.  This requirement helps safeguard the limited role of the doctrine of equivalents and ensures that the doctrine is not misapplied by a jury.

Full Opinion (PDF)

Citation: Nexstep, Inc. v. Comcast Cable Commc’ns, LLC, 119 F.4th 1355 (Fed. Cir. 2024)