United States Court of Appeals 

for the Federal Circuit ______________________ 

PROMPTU SYSTEMS CORPORATION,

Plaintiff-Appellant

v.

COMCAST CORPORATION, COMCAST CABLE 

COMMUNICATIONS, LLC,

Defendants-Appellees

______________________ 

2022-1939

______________________ 

Appeal from the United States District Court for the 

Eastern District of Pennsylvania in No. 2:16-cv-06516-JS, 

Chief Judge Juan R. Sanchez.

______________________ 

Decided: February 16, 2024

______________________ 

J. MICHAEL JAKES, Finnegan, Henderson, Farabow, 

Garrett & Dunner, LLP, Washington, DC, argued for plaintiff-appellant. Also represented by CHRISTOPHER 

BLACKFORD; BENJAMIN SCHLESINGER, Atlanta, GA; JACOB 

ADAM SCHROEDER, Palo Alto, CA. 

 MARK ANDREW PERRY, Weil, Gotshal & Manges LLP, 

Washington, DC, argued for defendants-appellees. Also 

represented by JOSHUA HALPERN; IAN ANTHONY MOORE, 

New York, NY. 

 ______________________ 

Case: 22-1939 Document: 56 Page: 1 Filed: 02/16/2024
2 PROMPTU SYSTEMS CORPORATION v. COMCAST CORPORATION

Before MOORE, Chief Judge, PROST and TARANTO, Circuit 

Judges.

TARANTO, Circuit Judge. 

In December 2016, Promptu Systems Corp. filed a complaint against Comcast Corp. in the Eastern District of 

Pennsylvania alleging that Comcast had infringed 

Promptu-owned U.S. Patent Nos. 7,047,196 and 7,260,538

and also asserting infringement of U.S. Reissued Patent 

No. RE44,326 and certain state-law bases for relief. In 

June 2022, before completion of discovery or any summaryjudgment proceedings, but after the district court adopted 

claim constructions that largely followed Comcast’s proposals, Promptu and Comcast jointly stipulated to the 

with-prejudice dismissal of Promptu’s ’326 patent-infringement claim and state-law claims. Based on the set of claim 

constructions adopted by the district court, Promptu also 

stipulated to and moved for entry of a final judgment of no 

infringement by Comcast of the ’196 and ’538 patents. The 

district court granted Promptu’s request and entered final 

judgment. 

Promptu appeals the judgment, challenging several of 

the underlying claim constructions. We conclude that the 

district court incorrectly construed certain claim terms. 

We therefore vacate the judgment and remand for further 

proceedings.

I 

A 

The ’196 patent begins its Summary of the Invention 

by stating that “[a]n embodiment of the invention provides 

speech recognition services to a collection of users over a 

network that supports cable television and/or video delivery.” ’196 patent, col. 5, lines 3–5. The patent identifies 

two relevant problems not solved in the prior art. First, 

sophisticated speech-recognition technology “requires state 

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PROMPTU SYSTEMS CORPORATION v. COMCAST CORPORATION 3

of the art processing software and hundreds of megabytes 

of RAM to support” it, which, the patent implies, prior-art 

set-top cable boxes typically could not provide. Id., col. 1, 

lines 54–56; see also id., col. 1, lines 30–62. Second, performing speech recognition at a centralized processing site, 

instead of on a user’s set-top box, requires the efficient upstream transmission (“from subscriber to cable plant”), using “limited bandwidth,” of speech commands and content 

from many users simultaneously, which, the patent says,

prior-art cable systems typically could not provide. Id., col.

2, lines 63–65; see also id., col. 2, line 60, through col. 3, line 

41. The patent specifically notes that, in one prior-art system cited as an example, upstream transmission “is quite 

inefficient due to the number of collisions which ensue, e.g. 

simultaneous transmissions from different set-top boxes 

which interfere with one another,” which “leads to typical 

channel utilization on the order of just 30%.” Id., col. 3, 

lines 33–38. 

The patent addresses the first problem through “a 

speech recognition system that is centrally located in or 

near a wireline node” or is “centrally located in or near a 

server farm,” “a web-site hosting facility,” or “a network 

gateway”—i.e., through performing speech recognition at a 

powerful remote computer, instead of at a local set-top box. 

Id., col. 5, lines 11–17. This “speech recognition and identification engine . . . is capable of processing thousands of 

speech commands simultaneously” and thus serving many 

users. Id., col. 5, lines 27–29. The patent addresses the 

second problem by using “a back channel containing a multiplicity of identified speech channels” where the “back 

channel is from a multiplicity of user sites.” Id., col. 22, 

lines 8–15; id., fig.10. Regarding how to achieve that 

many-in-one arrangement, the patent states that one 

method of doing so “may” be through the partitioning 

scheme—using both frequency and time-slot assignment—

set out in U.S. Patent Application No. 09/664,874 (incorporated by reference in the ’196 patent). See id., col. 27, lines 

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4 PROMPTU SYSTEMS CORPORATION v. COMCAST CORPORATION

48–54 (’196 patent incorporating the ’874 application by 

reference); J.A. 6898–929 (the ’874 application).1

Claims 1 and 53 are representative of the asserted 

claims of the ’196 patent for present purposes: 

1. A method of using a back channel containing a 

multiplicity of identified speech channels from a 

multiplicity of user sites presented to a speech processing system at a wireline node in a network supporting at least one of cable television delivery and 

video delivery, comprising the steps of:

receiving said back channel to create a received back channel;

partitioning said received back channel 

into a multiplicity of received identified 

speech channels;

processing said multiplicity of said received 

identified speech channels to create a multiplicity of identified speech content; and

responding to said identified speech content to create an identified speech content 

response that is unique, for each of said 

multiplicity of identified speech contents.

’196 patent, col. 50, line 62, through col. 51, line 10 (emphasis added).

1 Several times the patent specification gives the title of the ’874 application with the number of U.S. Patent 

Application No. 09/679,115. See, e.g., ’196 patent, col. 27, 

lines 49–53; id., col. 28, lines 1–3, 14–16, 39–42. Promptu 

explained that those references are to the ’874 application. 

Promptu Opening Br. at 47 n.1. Comcast does not disagree. 

Comcast Opening Br. at 32–33.

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PROMPTU SYSTEMS CORPORATION v. COMCAST CORPORATION 5

53. A method of operating at least part of a speech 

recognition system coupled to a wireline node in a 

network, comprising the steps of:

processing a multiplicity of received identified speech channels to create a multiplicity 

of identified speech content; and

responding to said identified speech content to create an identified speech content 

response that is unique to each of said multiplicity of identified speech contents;

wherein said speech recognition system is 

provided said multiplicity of received identified speech channels based upon a received back channel at said wireline node 

from a multiplicity of user sites coupled to 

said network;

wherein said network supports at least one 

of the collection comprising: cable television delivery to said multiplicity of user 

sites; and video delivery to said multiplicity 

of user sites.

Id., col. 58, lines 12–29 (emphasis added).

B 

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. See, e.g., ’538 patent, col. 2, lines 21–39.

Claim 34 is representative for present purposes: 

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6 PROMPTU SYSTEMS CORPORATION v. COMCAST CORPORATION

34. A centralized multi-user voice operated television control system, comprising:

television remote controls configured to directly and wirelessly control television sets 

and additionally to receive user voice input 

and wirelessly transmit first output representative of the voice input to television 

set-top boxes;

television set top boxes configured to receive television input signals via cable television link and provide television output 

signals compatible with television sets, the 

set top boxes additionally responsive to receiving the first output from the television 

remote controls to transmit representative 

second output to a central processing station via the cable television link;

a centralized processing station configured 

to receive and process second output from a 

multitude of television set top boxes by applying voice recognition to the second output to identify user-intended voice 

commands, to derive set-top-box-compatible instructions to carry out the identified 

voice commands, and returning signals 

representing the instructions to respective 

top boxes via the cable television link;

where the set top boxes are further responsive to receiving the signals representing 

the instructions from the central processing station to execute the instructions.

Id., col. 13, lines 37–61 (emphasis added).

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PROMPTU SYSTEMS CORPORATION v. COMCAST CORPORATION 7

C 

In December 2016, Promptu filed a complaint against 

Comcast in the Eastern District of Pennsylvania alleging, 

among other things, that Comcast had infringed the ’196 

and ’538 patents. J.A. 506. That litigation was stayed (at 

Promptu’s request, with Comcast’s agreement) between 

July 2018 and September 2020 after Comcast filed with the 

Patent and Trademark Office (PTO) eight petitions seeking 

review of the asserted patents: six for inter partes reviews

(IPRs) under 35 U.S.C. §§ 311–19, and two for covered 

business method (CBM) reviews under § 18 of the LeahySmith America Invents Act, Pub. L. No. 112-29, 125 Stat. 

284, 329–31 (2011). See J.A. 4839–48; J.A. 5144 (scheduling order noting the stay had been lifted). We have twice 

heard appeals from the PTO proceedings involving the ’196 

patent. See Comcast Cable Communications, LLC v. 

Promptu Systems Corp., 838 F. App’x 551 (Fed. Cir. 2021); 

Promptu Systems Corp. v. Comcast Cable Communications, 

LLC, No. 2022-1093, 2024 WL 163326 (Fed. Cir. Jan. 16, 

2024) (argued here the same day, before the same panel, as 

the present appeal). We have heard one appeal from the 

PTO proceedings involving the ’538 patent. See Comcast 

Cable Communications, LLC v. Promptu Systems Corp., 

838 F. App’x 555 (Fed. Cir. 2021). 

In May 2022, the district court issued claim construction orders, and in June 2022, the court issued a memorandum opinion explaining its claim constructions. The court 

largely adopted Comcast’s proposed constructions of the 

claim terms in the ’196 and ’538 patents now at issue before 

us. See Promptu Systems Corp. v. Comcast Corp., No. 16-

cv-06516, slip op. at 1–2 (E.D. Pa. May 12, 2022), ECF No. 

299 (Claim Construction Order); Promptu Systems Corp. v. 

Comcast Corp., No. 16-cv-06516 (E.D. Pa. May 19, 2022), 

ECF No. 301 (amending Claim Construction Order); 

Promptu Systems Corp. v. Comcast Corp., No. 16-cv-06516, 

slip op. at 4–18 (E.D. Pa. June 10, 2022), ECF No. 315 

(Memorandum Opinion).

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8 PROMPTU SYSTEMS CORPORATION v. COMCAST CORPORATION

Thereafter, Promptu and Comcast jointly stipulated to 

the with-prejudice dismissal of Promptu’s ’326 patent-infringement claim and state-law claims. J.A. 9530. 

Promptu also stipulated to and moved for entry of final 

judgment on its ’196 and ’538 patent-infringement claims 

“as a result of non-infringement by Comcast . . . based on 

the Court’s Claim Construction Order,” stating that it 

aimed to seek appellate review of at least four of the underlying claim constructions. J.A. 9530. In response, on June 

16, 2022, the district court dismissed Promptu’s ’326 patent-infringement claim and its state-law claims with prejudice, and it directed entry of final judgment for Comcast 

on Promptu’s ’196 and ’538 patent-infringement claims. 

See Promptu Systems Corp. v. Comcast Corp., No. 16-cv06516, slip op. at 1 (E.D. Pa. June 16, 2022), ECF No. 316.

Promptu filed a timely notice of appeal from the district 

court’s final judgment on June 21, 2022, J.A. 9449–51, 

within the thirty days allowed by 28 U.S.C. § 2107(a). The 

district court had jurisdiction under 28 U.S.C. § 1338, and 

we have jurisdiction under 28 U.S.C. § 1295(a)(1).

II

On appeal, Promptu challenges 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). For the “multiplicity of received identified 

speech channels” phrase, Promptu’s challenge relates to 

the meaning of the “speech channels” term. For the 

“speech recognition system coupled to a wireline node” 

phrase, Promptu separately challenges the district court’s 

construction with respect to the meanings of the “speech 

recognition system,” “coupled to,” and “wireline node” 

terms.

“Where, as here, a plaintiff concedes noninfringement 

by stipulation, we need only address the district court’s 

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PROMPTU SYSTEMS CORPORATION v. COMCAST CORPORATION 9

construction of the pertinent claims.” Starhome GmbH v. 

AT&T Mobility LLC, 743 F.3d 849, 854 (Fed. Cir. 2014). 

“We review claim construction based on intrinsic evidence 

de novo and review any findings of fact regarding extrinsic 

evidence for clear error.” Grace Instrument Industries, 

LLC v. Chandler Instruments Co., 57 F.4th 1001, 1008

(Fed. Cir. 2023). “We generally give words of a claim their 

ordinary meaning in the context of the claim and the whole 

patent document; [and] the specification particularly, but 

also the prosecution history, informs the determination of 

claim meaning in context, including by resolving ambiguities”; but “even if the meaning is plain on the face of the 

claim language, the patentee can, by acting with sufficient 

clarity, disclaim such a plain meaning or prescribe a special definition.” World Class Technology Corp. v. Ormco

Corp., 769 F.3d 1120, 1123 (Fed. Cir. 2014) (citing Phillips

v. AWH Corp., 415 F.3d 1303, 1312–17 (Fed. Cir. 2005) (en 

banc); Thorner v. Sony Computer Entertainment America

LLC, 669 F.3d 1362, 1365 (Fed. Cir. 2012)); see Personalized Media Communications, LLC v. Apple Inc., 952 F.3d

1336, 1339–40 (Fed. Cir. 2020). In this matter, prosecution 

history has played no substantial role in the parties’ contentions.

A 

We first conclude 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.” Claim Construction Order, at 2 (emphasis added).

1 

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), we see nothing in the 

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10 PROMPTU SYSTEMS CORPORATION v. COMCAST CORPORATION

meaning of the quite general term “channel” that limits the 

path to one defined by a fixed band of frequencies or time 

slots.

Nor does the ’196 patent’s specification require the particular path-definition technique demanded by the district 

court’s claim construction. The patent discusses the back 

channel, which contains a multiplicity of speech channels, 

broadly, defined by beginning at a user site (or sites) and 

ending at a speech processing system. See, e.g., ’196 patent, col. 50, lines 62–66; id., col. 22, lines 8–14. It recognizes the possibility of using different protocols or formats, 

including conversion between these, along different “subsections” of the path or route from user site to speech recognition system. See, e.g., id., col. 9, line 48, through col. 10, 

line 13 & fig.3 (describing passage through a “gateway” between different kinds of networks); id., col. 12, lines 57–65 

(similar); id., col. 10, lines 54–61 (describing how “[s]peech 

commands” may be “converted to digital signals” from “analog” or “preprocessed” including by “conversion to an alternative form of speech representation”). It also 

recognizes use of the DOCSIS cable-modem protocol, id., 

col. 11, lines 51–59, which it is undisputed need not, though 

can, use fixed frequency bands or time slots. Though “formats” and “protocols” may not be synonymous with “channels,” what the discussion indicates is breadth regarding 

techniques for the back channel. And there is no stated 

narrowing to a fixed frequency band or time slots. 

Moreover, the ’196 patent, through the incorporated 

’874 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. See, e.g., J.A. 6904–05 (describing a system 

where the “head-end receiver” performs “active frequency 

management of the upstream transmission spectrum” using “an allocation table . . . to keep track of the assignments 

of channels by storing a mapping between each channel 

and the set-top box to which the channel is assigned”); J.A. 

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PROMPTU SYSTEMS CORPORATION v. COMCAST CORPORATION 11

6906–10 (same for a “headend controller” that controls the 

“management and assignment of time slots”); cf. J.A. 6904 

(mentioning a transmission scheme that involves “enabling 

each set-top box to perform frequency hopping”). And Comcast’s expert—when addressing the ’196 patent’s description of a “Speech Packet Processor” that may “capture and 

prepare the upstream speech packets that are to be fed to 

the Speech Recognition Engine,” ’196 patent, col. 18, lines 

20–23—explained that “[s]uch packets may, or may not, be 

sent upstream using defined frequency bands, or ‘channels.’” J.A. 8215 ¶ 7 (emphasis added).

Use of a fixed frequency band or time slots, in this patent, is no more than exemplary, not required. The specification certainly refers to such use in describing 

embodiments. See, e.g., ’196 patent, col. 5, lines 22–26

(“This system is unique in that the speech command which 

originates at the user site . . . is sent upstream via the return path (often five to 40 MHz) in the cable system to a 

central speech recognition and identification engine.”); id., 

col. 44, lines 37–38 (“Each NTSC television channel has approximately 6 MHz of bandwidth.”); id., col. 31, lines 33–35 

(“The multiplexing mechanism onto channel 1332 may perform time division multiplexing.”). But the specification 

does not limit the channel-defining techniques to a fixed

frequency band or time slots. Similarly, the word “channel” 

also can be used to refer to particular frequencies or bands 

or time slots, as indicated by dictionaries on which Comcast 

relies. See, e.g., J.A. 2695, 2724, 2783; Comcast Response 

Br. at 23 (stating that “the district court’s construction is a 

common meaning of ‘channel’ in the relevant field of art”

(emphasis added)). But the dictionaries do not limit “channel” to such techniques for defining a path for signal transmission. See, e.g., J.A. 6729. And the district court made 

no finding that no other such techniques were known to 

relevant artisans at the time relevant to construing this 

patent. 

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12 PROMPTU SYSTEMS CORPORATION v. COMCAST CORPORATION

Our 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. See, e.g.,

Phillips, 415 F.3d at 1323; Liebel-Flarsheim Co. v. Medrad, 

Inc., 358 F.3d 898, 904–09 (Fed. Cir. 2004); Sjolund v. Musland, 847 F.2d 1573, 1582 (Fed. Cir. 1988) (reciting the

“general principle” that “limitations from the specification 

are not to be read into the claims”). That principle controls 

the claim construction of “back channel” here. The principle was important in several cases argued to us by Comcast 

and Promptu the same day as this one, where Comcast succeeded in defending unpatentability rulings of the Patent 

Trial and Appeal Board by resisting various arguments 

made by Promptu to limit claim terms’ scope to features of 

embodiments found in the specification.2 Here, where infringement is at stake, it is Comcast that is seeking a narrowing to embodiment features. We find the arguments for 

narrowing in this case are no more justified than the ones 

rejected in the Board matters.

2 

That conclusion suffices to reject the construction of 

“back channel” adopted by the district court. The parties 

also dispute whether “channel” in that phrase refers to a 

path in which a data stream flows (as Comcast says) or, 

instead, to the data stream that flows in the path (as 

Promptu says). Compare Comcast Response Br. at 28 

(“[T]he data are not the channel.”), with Promptu Reply Br. 

at 18 (“Promptu’s construction of ‘back channel’ as a stream 

2 See, e.g., Promptu Systems Corp. v. Comcast Cable 

Communications, LLC, No. 2020-1253, 2024 WL 163327 

(Fed. Cir. Jan. 16, 2024) (affirming decision of Board in 

CBM2018-00034); Promptu, 2024 WL 163326 (affirming 

decision of Board in IPR2018-00344).

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PROMPTU SYSTEMS CORPORATION v. COMCAST CORPORATION 13

conveys both concepts. A communication stream does not 

exist without data flowing through it, and that data necessarily follows a path from a source to a destination.” (citation omitted)). We leave this dispute to be addressed, if 

necessary, on remand.

For one thing, the proper resolution of the dispute is 

far from clear in light of the limited attention given to it 

here. For example, sometimes the ’196 patent specification 

seems to use “channel” to refer to the path. See, e.g., ’196 

patent, col. 3, lines 11–43 (referring to “channel utilization 

on the order of just 30%” due to signal interference between 

users; transmitting request signals “whether or not the 

transmission channel is already in use”; and stating that 

“[d]ownstream control data transmission typically occurs 

in a separate frequency band from the upstream channels”). On the other hand, while the patent sometimes refers to processing or receiving “signals” or a “stream” (or 

“channel stream”), e.g., id., col. 12, lines 21, 39, 47, 57–62; 

id., col. 42, lines 33–34, 41–49; id., col. 47, line 29, the patent also frequently refers to “processing” or “receiving” a 

“channel,” which tends to suggest that “channel,” at least 

in those references, means the data stream, not the path (it 

being awkward to describe a path as being processed or, 

perhaps, received), see, e.g., id., Abstract; id., figs.10, 11B, 

18B; id., col. 2, lines 30–31; id., col. 4, lines 27, 32–33; id., 

col. 22, lines 25–26, 31–32, 46–48; id., col. 23, lines 3–14; 

id., col. 25, lines 55–60; id., col. 40, lines 4–5, 17–19, 24–31; 

id., col. 51, lines 1–7 (claim 1). Relatedly, we described the 

patent’s phrase “received back channel” as the “back channel” at a later point in time, Comcast, 838 F. App’x at 554, 

and that phrase has now been given an unchallenged construction as meaning “[d]ata received via the back channel,” Claim Construction Order, at 2—in which the “data” 

term seems to use “channel” to refer to data while the “via 

the back channel” phrase seems to use “channel” to refer to 

the path.

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14 PROMPTU SYSTEMS CORPORATION v. COMCAST CORPORATION

Although “[w]hen the parties present a fundamental 

dispute regarding the scope of a claim term, it is the court’s 

duty to resolve it,” courts “are not (and should not be) required to construe every limitation present in a patent’s asserted claims.” O2 Micro International Ltd. v. Beyond 

Innovation Technology Co., 521 F.3d 1351, 1362 (Fed. Cir. 

2008). The purpose of claim construction is to resolve “disputed meanings and technical scope, to clarify and when 

necessary to explain what the patentee covered by the 

claims, for use in the determination of infringement” or invalidity. U.S. Surgical Corp. v. Ethicon, Inc., 103 F.3d 

1554, 1568 (Fed. Cir. 1997). Accordingly, “only those terms 

need be construed that are in controversy, and only to the 

extent necessary to resolve the controversy.” Vivid Technologies, Inc. v. American Science & Engineering, Inc., 200 

F.3d 795, 803 (Fed. Cir. 1999). 

Here, it is not clear how significant this path-versusstream dispute is as a practical matter. Promptu’s counsel 

stated during oral argument that, although it is crucial to 

decide whether a “back channel” requires fixed frequency 

bands or time slots, it might not be necessary to decide 

whether the “back channel” is a path or route or is instead 

the stream (alone or in combination with its path). Oral 

Arg. at 7:05–8:00. In these circumstances, we leave any 

resolution of this aspect of the parties’ dispute for the district court to consider on remand.

B 

We similarly reject 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. Claim Construction Order, at 2 (emphasis 

added). This construction depends on the underlying construction of “channel,” which we have rejected. There is no 

stronger reason to limit an identified speech channel to a 

single frequency band or designated time slot than to limit 

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PROMPTU SYSTEMS CORPORATION v. COMCAST CORPORATION 15

the “back channel” as the rejected claim construction of 

that phrase does.

We also note that the district court required, in the present construction, that “each channel” is “assigned to a particular user site.” Id. But the ’196 patent contains 

dependent claims that recite the additional limitation that 

“at least one of said identified speech channels has an associated user site.” See, e.g., ’196 patent, col. 51, lines 12–

13. That associated-user-site limitation must therefore be 

presumed absent from the “multiplicity of received identified speech channels” phrase that provides its antecedent 

basis. See Karlin Technology, Inc. v. Surgical Dynamics, 

Inc., 177 F.3d 968, 971–72 (Fed. Cir. 1999) (“[L]imitations 

stated in dependent claims are not to be read into the independent claim from which they depend.”). We see no sufficient justification for requiring “each channel” to be 

“assigned to a particular user site.” 

C 

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.” Claim Construction Order, at 2. That construction 

incorrectly construes the constituent terms “speech recognition system,” “coupled to,” and “wireline node” within the 

claim phrase.

1 

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 

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16 PROMPTU SYSTEMS CORPORATION v. COMCAST CORPORATION

exclusivity—which Comcast itself did not urge. 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. See, e.g., ’196 patent, col. 36, lines 24–34; id., col. 41, 

lines 8–40. 

We do not go further to find words for a proper construction to replace the one we reject. The parties have not 

adequately explored alternatives, and again we are not 

sure what aspects of the phrase need clarification for resolution of the liability issues. Additional exploration should 

take place on remand, to the extent necessary, of the best 

way to characterize the limitation of “system” effected by 

the use of the phrasal modifier “speech recognition.” It may 

be relevant that the specification indicates that the slightly 

longer phrase, “speech recognition processor system,” does 

not encompass the remote-control device, the televisions, 

the telephone, the optical nodes, the set-top box, the gateway, the server farm, or the server array—which are depicted as distinct elements separate from the “speech 

recognition processor system.” ’196 patent, fig.3. Importantly, a claim construction, if needed at all, should help 

resolve, not add to, uncertainty in the understanding the 

finder of fact is to use in applying a claim term.

2 

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. Claim 

Construction Order, at 2. We have several times held variants of “coupled to” in patent claims before us to mean 

simply “connected to.” See General Electric Co. v. International Trade Commission, 685 F.3d 1034, 1045 (Fed. Cir. 

2012) (“[T]he term ‘coupled with’ indicates a connection.”); 

Johnson Worldwide Associates, Inc. v. Zebco Corp., 175 

F.3d 985, 992 (Fed. Cir. 1999) (“[T]he unmodified term ‘coupled’ generically describes a connection, and does not 

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PROMPTU SYSTEMS CORPORATION v. COMCAST CORPORATION 17

require a mechanical or physical coupling.”). We see no 

sufficient reason to add a proximity requirement here. 

The ’196 patent describes, for example, a “coupling” 

that may involve “wireless physical transport,” ’196 patent, 

col. 10, lines 62–66, or a “server farm” with “communicatively coupled” servers, id., col. 9, lines 59–61. The ’196 

patent’s specification states that “[t]he invention comprises 

. . . a speech recognition system that is centrally located in 

or near a wireline node” but also states that the “speech 

recognition system may also be centrally located in or near 

a server farm[,] a website hosting facility, or a network 

gateway.” Id., col. 5, lines 11–17. Setting aside that “centrally located” is not the claim term—“coupled to” is—the 

statement that a speech recognition system may be located 

“in or near” sites other than the wireline node further implies that proximity between the speech recognition system 

and the wireline node (via coupling) is not required.

We construe “coupled to” as meaning “connected to.” 

3 

The district court improperly adopted the specification’s definition of “centralized wireline node” when construing the claim term “wireline node.” Memorandum 

Opinion, at 13 (emphasis added); ’196 patent, col. 1, line 

66, through col. 2, line 2 (“[A] centralized wireline node refers to a network node providing video or cable television 

delivery to multiple users using a wireline physical 

transport between those users at the node.”). 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. See Johnson, 175 F.3d at 989 (“[M]odifiers will not 

be added to broad terms standing alone.”). We see nothing 

troubling about a patent defining a modified term in the 

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18 PROMPTU SYSTEMS CORPORATION v. COMCAST CORPORATION

specification and then using that term without modification in the claims, particularly since a single patent specification may provide support for a variety of continuation 

and continuation-in-part applications as claims are accepted, rejected, and amended throughout prosecution. 

Promptu’s proposed construction (“node connected by a 

wire, as opposed to a wireless connection,” Memorandum 

Order, at 12) is consistent with the scope of the claim language and specification, and we adopt it here.

D 

Promptu challenges two aspects of 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.” Memorandum Opinion, at 7. The first aspect challenged is the location requirement: that a “centralized processing station” must be 

located “at a cable-TV network head-end unit.” Id. The 

second aspect challenged is the function requirement: that 

the “centralized processing station” itself “performs voice 

recognition on voice commands.” Id. at 8–9. We affirm the 

latter aspect of the claim construction (the function requirement) but reverse the former aspect (the location requirement).

The district court correctly understood that the claim 

language, read as a whole, specifies that the “centralized 

processing station” (or some element of it) performs the recited speech recognition. Claim 34, for example, states that 

the “centralized processing station” is “configured to receive and process” output “by applying voice recognition” 

“to identify” voice commands and “to derive set-top-boxcompatible instructions.” ’538 patent, col. 13, lines 51–58 

(emphasis added). Particularly because it is the “centralized processing station” that is itself “configured to” perform the required voice-recognition actions (i.e., to receive 

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PROMPTU SYSTEMS CORPORATION v. COMCAST CORPORATION 19

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. 

In contrast, we conclude that, when construing “centralized processing station,” the district court incorrectly 

required the recited “device” to be located “at a cable-TV 

head-end unit.” Memorandum Opinion, at 7. It is clear 

that a “head-end unit” and a “centralized processing station” are different things: the two phrases are different 

claim elements used in separate claims throughout the ’538 

patent. See Tandon Corp. v. U.S. International Trade 

Commission, 831 F.2d 1017, 1023 (Fed. Cir. 1987) (“There 

is presumed to be a difference in meaning and scope when 

different words or phrases are used in separate claims.”). 

The district court did not disagree. Rather, the court concluded that these separate claim elements must be colocated. 

The district court relied on the specification’s statement that “[t]he voice command is then transmitted, for example, to a central processing station located at a cable 

television head-end unit,” ’538 patent, col. 2, lines 29–32; 

Memorandum Opinion, at 7–8, as support for its determination that the “centralized processing station” is located 

by definition at the head-end unit. Additionally, the specification cites element 160 in figure 1 as labelling both “a 

head-end unit 160” and “the central processing station 

160.” See ’538 patent, col. 4, lines 4, 8–9, 20; id., fig.1. But 

those bases, we conclude, are insufficient for the conclusion 

drawn by the district court. 

As confirmed by the “for example” language, the colocation noted in the above quoted sentence is merely exemplary. ’538 patent, col. 2, lines 29–32. And the use of a 

single figure-element number when referring to the 

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20 PROMPTU SYSTEMS CORPORATION v. COMCAST CORPORATION

centralized processing station and the head-end unit likewise need not mean anything more than that, in the embodiment illustrated in figure 1, the two components are 

colocated. Neither of those specification sources implies 

that the two components must be colocated. 

Such a limitation would read embodiment features into 

a claim term that is not so limited. The “centralized” term 

in “centralized processing station,” as the claim language 

makes clear, refers simply to its relation to a group of settop boxes. See Comcast Response Br. at 61 (“The claim 

term ‘centralized processing station’ makes clear that the 

processing station is a discrete physical thing (a ‘station’) 

that is centrally located (‘centralized’) vis-à-vis the ‘multitude of television set top boxes’ from which it receives signals.” (citing ’538 patent, col. 13, lines 37–61)). Such 

centralization exists when the station is in the cable network, serving many set-top boxes, whether or not it is located at the same place as a head-end unit. 

III

We vacate the district court’s entry of final judgment 

as it relates to Promptu’s ’196 and ’538 patent-infringement claims. We reverse in part and affirm in part the district court’s claim constructions. We remand to the district 

court for further proceedings.

The parties shall bear their own costs.

VACATED IN PART, REVERSED IN PART, 

AFFIRMED IN PART, AND REMANDED

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