In Promptu Systems Corp. v. Comcast Corp., [2022-1939] (February 16, 2024), the Federal Circuit vacated judgment of non-infringement of U.S. Patent Nos. 7,047,196, 7,260,538, NS RE44,326, and remanded for further proceedings

U.S. Patent Nos. 7,047,196

The ‘196 patent provides speech recognition services to a collection of users over a network that supports cable television and/or video delivery.

U.S. Patent No. 7,260,538

The ’538 patent describes and claims related subject matter, but the ’538 patent’s specification is materially different from the ’196 patent’s specification. At a general level, the primary distinction between the ’196 patent and the ’538 patent is that the former relates to using remote voice-recognition systems to deliver requested (cable or video) content in response to a user’s speech request, while the latter relates to using remote voice-recognition systems to control a user’s television set based on a user’s speech command.

On appeal, Promptu challenged the district court’s construction of four claim limitations: “back channel,” “multiplicity of received identified speech channels,” “speech recognition system coupled to a wireline node” (each from the ’196 patent), and “centralized processing station” (from the ’538 patent).

The Federal Circuit agreed that the district court erred by narrowly construing “back channel” in the ’196 patent as limited to “[a] fixed band of frequencies or time slot(s) for transmitting signals to a speech processing system or engine.” The Federal Circuit said that nothing in the claim language suggests the limitation to a fixed band of frequencies or time slots. “Back” undisputedly refers to the direction (upstream) opposite the direction of transmission of the programming (downstream). And whether “channel” means a path or what is flowing in the path (an issue discussed infra), the Court saw nothing in the meaning of the quite general term “channel” that limits the path to one defined by a fixed band of frequencies or time slots. The Federal Circuit also found that nothing in the ’196 patent’s specification require the particular path-definition technique demanded by the district court’s claim construction. Moreover, the ’196 patent, through an incorporated application, describes schemes that involve signal transmission along the back channel on dynamically assigned
and managed (i.e., not fixed) frequency bands or time slots.

The Federal Circuit found that the use of a fixed frequency band or time slots, in this patent,
is no more than exemplary, not required. The specification did not limit the channel-defining techniques to a fixed frequency band or time slots. Case law has long recognized that particular features recited in the specification merely as aspects of embodiments,
and not expressly or even implicitly identifying requirements of the invention, do not narrow a claim term that is otherwise broader in its ordinary meaning.

The Federal Circuit similarly rejected the district court’s construction of the “multiplicity of received identified speech channels” phrase in the ’196 patent as requiring “a single band of frequencies or a designated time slot” for each identified speech channel. The construction depends on the underlying construction of “channel,” which the Federal Circuit rejected.

The district court construed the “speech recognition system coupled to a wireline node” phrase in the ’196 patent, in sum, as “a system whose function is speech recognition”
“connected in or near” “a network node providing video or cable television delivery to multiple users using a wireline physical transport between those users at the node.” The Federal Circuit said that construction incorrectly construes the constituent terms “speech recognition system,” “coupled to,” and “wireline node” within the claim phrase.

The Federal Circuit said that the district court’s construction of “speech recognition system” as “a system whose function is speech recognition” improperly presupposes that speech recognition is the exclusive function of the speech recognition system. Claim Construction Order, at 2 (emphasis added). The claim term, “speech recognition system,” does not entail such exclusivity. Further, the ’196 patent’s specification describes functions that a “[s]peech processor computer” may perform other than speech recognition, such as billing and system management.

The Federal Circuit said that the district court’s construction of “coupled to” as “connected
in or near” incorrectly reads a proximity requirement (“in or near”) into the claim term at issue. The Federal Circuit has repeatedly held variants of “coupled to” in patent claims to mean simply “connected to.”

The Federal Circuit said that the district court improperly adopted the specification’s
definition of “centralized wireline node” when construing the claim term “wireline node.” The Federal Circuit reasoned that the “centralized” modifier (used in the composite term defined in the specification) must add some meaning to or limitation on the “wireline node” being modified. The absence of the “centralized” modifier in the claims, in turn, means that
the claimed “wireline node” must be broader in some way than the “centralized wireline node” defined in the specification.

The Federal Circuit also found fault with the district court’s claim construction of “centralized processing station” in the ’538 patent as a “device at a cable-TV network head-end unit that receives and performs voice recognition on voice commands, and generates and returns instructions to settop boxes to carry out the commands.” The Federal Circuit noted that the location requirement: that a “centralized processing station” must be located “at a cable-TV network head-end unit.” The “centralized processing station” that is itself “configured to” perform the required voice-recognition actions (i.e., to receive and process output by applying voice recognition, to identify voice commands, and to derive instructions), the claims fairly specify that the “centralized processing station” performs the claimed voice recognition, rather than merely applies the results of such voice recognition performed
elsewhere. The Federal Circuit said that the district court incorrectly required the recited “device” to be located “at a cable-TV head-end unit,” based upon an example in the specification.

The Federal Circuit vacated the district court’s entry of final judgment as it relates to Promptu’s ’196 and ’538 patent-infringement claims. The Fedeal Circuit reversed in part and affirmed in part the district court’s claim constructions, and remanded to the district
court for further proceedings.