United States Court of Appeals 

for the Federal Circuit ______________________ 

INTERVAL LICENSING LLC,

Plaintiff-Appellant,

v.

AOL, INC.,

Defendant-Appellee,

AND

APPLE, INC.,

Defendant-Appellee,

AND

GOOGLE, INC.,

Defendant-Appellee,

AND

YAHOO! INC.,

Defendant-Appellee.

______________________ 

2013-1282, -1283, -1284, -1285

______________________ 

Appeals from the United States District Court for the 

Western District of Washington in Nos. 13-CV-0263, 13-

CV-0264, 13-CV-0265 and 13-CV-0266, Judge Marsha J. 

Pechman.

______________________ 
2 INTERVAL LICENSING LLC v. AOL, INC. 

Decided: September 10, 2014

______________________ 

THOMAS C. GOLDSTEIN, Goldstein & Russell, PC, of 

Washington, DC, argued for plaintiff-appellant. Of counsel on the brief were MICHAEL HEIM, NATHAN J. DAVIS,

and DOUGLAS R. WILSON, Heim, Payne & Chorush LLP, of 

Houston, Texas; JUSTIN A. NELSON, Susman Godfrey 

L.L.P., of Seattle, Washington, and MAX L. TRIBBLE, JR., 

of Houston, Texas. 

J. MICHAEL JAKES, Finnegan, Henderson, Farabow, 

Garrett & Dunner, LLP, of Washington, DC, argued for 

all defendants-appellees. With him on the brief were 

GERALD F. IVEY, CORTNEY S. ALEXANDER, ROBERT L.

BURNS, II, and ERIK R. PUKNYS, for AOL Inc.; ELIZABETH 

DAY, DAVID ALBERTI, and MARC C. BELLOLI, Feinberg Day 

Alberti & Thompson LLP, of Menlo Park, California, and 

BRIAN BERLINER, O’Melveny & Myers, LLP, of Los Angeles, California, for Apple Inc.; WARREN S. HEIT, CARMEN 

LO, and WENDI R. SCHEPLER, White & Case LLP, of Palo 

Alto, California, and KEVIN MCGANN and DIMITRIOS T.

DRIVAS, of New York, New York, for Google Inc.; and

DEANNE MAYNARD, Morrison & Foerster LLP, of Washington, DC, and MICHAEL A. JACOBS and MATTHEW I.

KREEGER, of San Francisco, California, for Yahoo! Inc. 

______________________ 

Before TARANTO and CHEN, Circuit Judges.

∗

∗ Randall R. Rader, who retired from the position of 

Circuit Judge on June 30, 2014, did not participate in this 

decision.

 
INTERVAL LICENSING LLC v. AOL, INC. 3

CHEN, Circuit Judge.

Interval Licensing LLC (“Interval”) appeals from four 

stipulated final judgment orders of the United States 

District Court for the Western District of Washington.1 

Each order granted: (1) final judgment of invalidity of 

claims 4–8, 11, 34, and 35 of U.S. Patent 6,034,652 (“the 

’652 patent”) and claims 1–4 and 7–15 of U.S. Patent 

6,788,314 (“the ’314 patent”), based on the court’s determination that those claims are indefinite; and (2) final

judgment of non-infringement of claims 15–18 of the ’652 

patent, based on the court’s claim construction of the 

phrase “during operation of an attention manager.” While 

we agree with the court’s indefiniteness determination, 

we do not agree with the court’s construction of “attention 

manager” and thus modify that construction. Additionally, we modify the court’s construction of the term “instructions.” For the reasons set forth below, we affirm the 

judgments of invalidity, vacate the judgments of noninfringement, and remand for further proceedings. 

BACKGROUND

The ’652 and ’314 patents are directed to an “attention 

manager for occupying the peripheral attention of a 

person in the vicinity of a display device.” The patents, 

which share a common specification, describe a system 

that acquires data from a content provider, schedules the 

display of the content data, generates images from the 

content data, and then displays the images on a device. 

1 Interval sued the four appellees for infringement 

in the district court. Due to complicated procedural 

reasons not relevant here, the court severed all of the 

claims and counterclaims into four cases, issuing separate 

final judgment orders of invalidity and non-infringement 

for each case. Interval appealed each order, and the four 

appeals were consolidated into the present appeal. 

 
4 INTERVAL LICENSING LLC v. AOL, INC. 

The patents explain that the term “image” is used “broadly here to mean any sensory stimulus that is produced 

from the set of content data, including, for example, visual 

imagery (e.g., moving or still pictures, text, or numerical 

information) and audio imagery (i.e., sounds).” ’652 

patent, 6:60–64. The content data presented in the images are “virtually limitless,” and may include advertisements, video nature scenes, and radio talk shows. Id. at 

7:26–38. As for the users of the attention manager, the 

patents contemplate that the system will typically occupy 

the attention of human users, but may also be used to 

occupy the attention of dogs, cats, and parrots. See id. at 

29:32–40. The primary issues raised on appeal center on

the manner in which the patented invention displays 

content data—specifically, how the attention manager

displays “images” so as to attract the peripheral attention 

of the user. 

To engage the “peripheral attention” of a user in “the 

vicinity of a display device,” the attention manager 

“[g]enerally . . . makes use of ‘unused capacity’ of the 

display device.” Id. at 2:3–9. The specification discloses 

two primary approaches to utilizing “unused capacity.” 

First, the specification describes a “screen saver embodiment” that displays images “automatically after detection 

of an idle period” or after activation of the screen saver by 

the user. Id. at 3:19–22, 9:24–36. The patents use screen 

savers—typically used for preventing screen burnout and 

for “aesthetic or entertainment value”—for the purpose of 

“display[ing] content from a remote location via a computer network.” Id. at 1:39–67. The screen saver embodiment may be employed “while a primary interaction is 

ongoing, but during inactive periods (i.e., when the user is 

not engaged in an intensive interaction with the apparatus).” Id. at 6:35–38. 

Second, the specification describes a wallpaper embodiment. “Wallpaper,” the specification explains, is “a 

pattern generated in the background portions on a com-
INTERVAL LICENSING LLC v. AOL, INC. 5

puter display screen.” Id. at 1:51–52. The patents’ “wallpaper embodiment” displays images “while the user is 

engaged in a primary interaction with the apparatus, 

which primary interaction can result in the display of an 

image or images in addition to the image or images generated from the set of content data.” Id. at 3:25–31. The 

wallpaper embodiment makes use of the “unused” spatial 

capacity of a screen, displaying information in areas not 

used by the user’s primary interaction. Id. at 6:38–51. 

On August 27, 2010, Interval sued AOL Inc., Apple 

Inc., Google Inc., and Yahoo! Inc. (the “Defendants”) in the 

Western District of Washington, alleging infringement of 

four patents, including the ’652 and ’314 patents. Interval’s suit alleged that the Defendants infringe the patents 

through products and software that use “pop-up” notifications to present information to users. In early 2011, two 

of the Defendants filed a request for ex parte reexamination of the ’652 patent, while another defendant filed a 

request for inter partes reexamination of the ’314 patent. 

The district court stayed the litigation pending the 

USPTO’s reexaminations. Examiners found the asserted 

claims of both patents to be patentable in view of the cited 

prior art.2 The district court then lifted the stay with 

respect to the ’652 and ’314 patents, proceeding to claim 

construction.

Of the twenty-five claims Interval asserted in the ’652 

and ’314 patents, all but four contain or depend on the 

2 After the present appeal was argued, the Patent 

Trial and Appeal Board reversed the examiner’s decision 

of the inter partes reexamination of the ’314 patent. The 

Board rejected all of the asserted claims of the ’314 patent 

as obvious, anticipated, or both. See Apple, Inc. v. Interval Licensing LLC, No. 2013-005424, 2014 WL 1322685, 

at *16 (Patent Tr. & App. Bd. Apr. 1, 2014). Interval has 

indicated that it intends to appeal the Board’s decision. 

 
6 INTERVAL LICENSING LLC v. AOL, INC. 

phrase “in an unobtrusive manner that does not distract a 

user.” Claim 1 of the ’314 patent is representative:

A method for engaging the peripheral attention of 

a person in the vicinity of a display device, 

comprising the steps of:

providing one or more sets of content data to a 

content display system associated with the 

display device and located entirely in the 

same physical location as the display device;

providing to the content display system a set of 

instructions for enabling the content display 

system to selectively display, in an unobtrusive manner that does not distract a 

user of the display device or an apparatus associated with the display device 

from a primary interaction with the 

display device or apparatus, an image 

or images generated from a set of content data; and

auditing the display of sets of content data by 

the content display system;

wherein the one or more sets of content data 

are selected from a plurality of sets of content data, each set being provided by an associated content provider, wherein each 

associated content provider is located in a 

different physical location than at least one 

other content provider and each content provider provides its content data to the content 

display system independently of each other 

content provider and without the content data being aggregated at a common physical location remote from the content display 

system prior to being provided to the content 

display system, and wherein for each set the 
INTERVAL LICENSING LLC v. AOL, INC. 7

respective content provider may provide 

scheduling instructions tailored to the set of 

content data to control at least one of the duration, sequencing, and timing of the display 

of said image or images generated from the 

set of content data.

’314 patent, 29:53–30:18 (emphasis added).

Although all of the asserted claims in the ’314 patent 

depend on the “unobtrusive manner” language, four of the 

asserted claims in the ’652 patent do not. Representative 

claim 15 recites: 

A computer readable medium encoded with one or 

more computer programs for enabling acquisition of a set of content data and display of an 

image or images generated from the set of content data on a display device during operation of an attention manager, comprising:

acquisition instructions for enabling acquisition 

of a set of content data from a specified information source;

user interface installation instructions for enabling provision of a user interface that allows 

a person to request the set of content data 

from the specified information source;

content data scheduling instructions for providing temporal constraints on the display of 

the image or images generated from the set 

of content data, wherein the content data 

scheduling instructions further comprise sequencing instructions that specify an order 

in which the images generated from a set of 

content data are displayed; and
8 INTERVAL LICENSING LLC v. AOL, INC. 

display instructions for enabling display of the 

image or images generated from the set of 

content data.

’652 patent, 32:37–58 (emphasis added).

In its claim construction order, the district court 

found that “the terms ‘in an unobtrusive manner’ and 

‘does not distract’ a user, whether used together or separately,”3 are indefinite. Interval Licensing, LLC v. AOL, 

Inc., C10-1385MJP, 2013 WL 792791, at *3 (W.D. Wash. 

Feb. 28, 2013). After reviewing the claim language, the 

written description, and the prosecution history, the 

district court offered two primary reasons for holding the 

claim language indefinite: (1) “because the patents fail to 

provide an objective standard by which to define the scope 

of [the ‘unobtrusive manner’ phrase]”; and (2) “because 

the determination of whether an accused product would 

meet the claim limitations depends on its usage in changing circumstances.” Id. at *5.

The district court also construed several disputed 

claim terms. Relevant here, the court construed the term 

“attention manager” as limited to the specific screensaver 

and wallpaper embodiments. See id. at *10–11 (adopting

Defendants’ construction of “a system that displays images to a user either when the program detects that the user 

is not engaged in a primary interaction or as a background of the computer screen”). The court also adopted

3 As Interval observes, much of the district court’s 

indefiniteness analysis treats “unobtrusive manner” and 

“does not distract a user” as distinct claim limitations. 

Interval argues that “[b]ecause the phrase is used as a 

whole repeatedly throughout the specification and 

claims . . . all of the words of the phrase should be construed together.” Appellant’s Br. 28 n.5. We agree and 

evaluate the phrase accordingly in this opinion. 

 
INTERVAL LICENSING LLC v. AOL, INC. 9

the Defendants’ construction of “instructions,” a term 

which appears in many of the asserted claims. See id. at 

*15–16 (construing “instructions” as “a statement in a 

programming language that specifies a function to be 

performed by a system”). 

Based on the claim construction order, the parties 

stipulated that twenty-one claims in both patents were 

invalid as indefinite, and that claims 15–18 of the ’652 

patent were not infringed by the Defendants. On February 18, 2013, the district court issued final judgment 

orders to that effect, which Interval timely appeals. 

Interval asks us to reverse the district court’s holding that 

the claim phrase “in an unobtrusive manner that does not 

distract a user” is indefinite,

4 vacate the court’s construction of “attention manager,” and clarify the court’s construction of “instructions.”

4 The district court separately addressed independent claim 4 of the ’652 patent, which uses the “unobtrusive manner” phrase in a means-plus-function limitation. 

See ’652 patent, 30:29–33 (claiming a “means for selectively displaying on the display device, in an unobtrusive 

manner that does not distract a user”). The court held 

that claim 4 and its dependent claims were indefinite 

because the specification does not disclose an algorithm 

that would constitute sufficient structure for accomplishing the recited function. Interval, 2013 WL 792791, at *9. 

Interval asks us to reverse that holding. However, because we affirm the district court’s determination that the 

“in an unobtrusive manner that does not distract a user” 

phrase is indefinite under 35 U.S.C. § 112, ¶ 2 for the 

reasons stated in this opinion, we find it unnecessary to 

address the district court’s additional determination that 

the means-plus-function claims are indefinite due to a 

lack of corresponding structure in the specification.

 
10 INTERVAL LICENSING LLC v. AOL, INC. 

We have jurisdiction pursuant to 28 U.S.C. 

§ 1295(a)(1).

DISCUSSION

I. Indefiniteness

A patent must “conclude with one or more claims particularly pointing out and distinctly claiming the subject 

matter which the applicant regards as [the] invention.” 

35 U.S.C. § 112, ¶ 2 (2006).5 A claim fails to satisfy this 

statutory requirement and is thus invalid for indefiniteness if its language, when read in light of the specification 

and the prosecution history, “fail[s] to inform, with reasonable certainty, those skilled in the art about the scope 

of the invention.” Nautilus, Inc. v. Biosig Instruments, 

Inc., 134 S. Ct. 2120, 2124 (2014). We review the district 

court’s indefiniteness determination here de novo. See

Wellman, Inc. v. Eastman Chem. Co., 642 F.3d 1355, 1365 

(Fed. Cir. 2011); Young v. Lumenis, Inc., 492 F.3d 1336, 

1344 (Fed. Cir. 2007).6 

5 Paragraph 2 of 35 U.S.C. § 112 was replaced with 

newly designated § 112(b) when § 4(c) of the America 

Invents Act (“AIA”), Pub. L. No. 112-29, took effect on 

September 16, 2012. Because the applications resulting 

in the patents at issue in this case were filed before that 

date, we will refer to the pre-AIA version of § 112.

6 We note that the district court’s indefiniteness determination rests only on intrinsic evidence, and that 

there are no disputes about underlying questions of fact. 

Although the Defendants point to the testimony of Interval’s expert in support of their argument that the “unobtrusive manner” phrase is indefinite, see Appellee’s Br. 32, 

we find it unnecessary to rely on that testimony (or any 

other extrinsic evidence) to reach our conclusion. Like the 

district court, we find the claims indefinite based on the 

 
INTERVAL LICENSING LLC v. AOL, INC. 11

A 

After the present appeal was argued, the Supreme 

Court issued its opinion in Nautilus, Inc. v. Biosig Instruments, Inc., which addressed our use of the expressions “insolubly ambiguous” and “amenable to 

construction” in applying § 112, ¶ 2. The Court explained 

that the statute’s definiteness requirement calls for a

“delicate balance.” Nautilus, 134 S. Ct. at 2128 (quoting 

Festo Corp. v. Shoketsu Kinzoku Kogyo Kabushiki Co., 

Ltd., 535 U.S. 722, 731 (2002)). The definiteness standard

“must allow for a modicum of uncertainty” to provide 

incentives for innovation, but must also require “clear 

notice of what is claimed, thereby appris[ing] the public of 

what is still open to them.” Id. at 1228, 1229 (internal 

citations omitted). In light of that balance, the Court 

characterized our “insolubly ambiguous” and “amenable 

to construction” expressions as “more amorphous than the 

statutory definiteness requirement allows.” Id. at 2131. 

What the statute requires, the Court clarified, “is that a 

patent’s claims, viewed in light of the specification and 

prosecution history, inform those skilled in the art about 

the scope of the invention with reasonable certainty.” Id.

at 2129.

The key claim language at issue in this appeal includes a term of degree (“unobtrusive manner”). We do 

not understand the Supreme Court to have implied in 

Nautilus, and we do not hold today, that terms of degree 

are inherently indefinite. Claim language employing 

terms of degree has long been found definite where it 

provided enough certainty to one of skill in the art when 

read in the context of the invention. See, e.g., Eibel Process Co. v. Minnesota & Ontario Paper Co., 261 U.S. 45, 

65–66 (1923) (finding “substantial pitch” sufficiently 

claims, the written description, and the prosecution 

history.

 
12 INTERVAL LICENSING LLC v. AOL, INC. 

definite because one skilled in the art “had no difficulty . . . in determining what was the substantial pitch 

needed” to practice the invention). As the Supreme Court 

recognized in Nautilus, “absolute precision” in claim 

language is “unattainable.” 134 S. Ct. at 2129; see also

Enzo Biochem, Inc. v. Applera Corp., 599 F.3d 1325, 1335 

(Fed. Cir. 2010) (holding that the claim phrase “not interfering substantially” was not indefinite even though the 

construction “define[d] the term without reference to a 

precise numerical measurement”); Invitrogen Corp. v. 

Biocrest Mfg., L.P., 424 F.3d 1374, 1384 (Fed. Cir. 2005)

(“[A] patentee need not define his invention with mathematical precision in order to comply with the definiteness 

requirement.”). 

Although absolute or mathematical precision is not 

required, it is not enough, as some of the language in our 

prior cases may have suggested, to identify “some standard for measuring the scope of the phrase.” See Appellant’s Br. 31 (quoting Datamize, LLC v. Plumtree 

Software, Inc., 417 F.3d 1342, 1351 (Fed. Cir. 2005)). The 

Supreme Court explained that a patent does not satisfy 

the definiteness requirement of § 112 merely because “a 

court can ascribe some meaning to a patent’s claims.” 

Nautilus, 134 S. Ct. at 2130. The claims, when read in 

light of the specification and the prosecution history, must 

provide objective boundaries for those of skill in the art. 

See id. at 2130 & n.8 (indicating that there is an indefiniteness problem if the claim language “might mean 

several different things and ‘no informed and confident 

choice is available among the contending definitions’” 

(quoting Every Penny Counts, Inc. v. Wells Fargo Bank, 

N.A., __ F. Supp. 2d __, 2014 WL 869092, at *4 (M.D. Fla. 

Mar. 5, 2014)); see also Halliburton Energy Servs., Inc. v. 

M-I LLC, 514 F.3d 1244, 1251 (Fed. Cir. 2008) (“The fact 

that [the patent holder] can articulate a definition supported by the specification . . . does not end the inquiry. 

Even if a claim term’s definition can be reduced to words, 
INTERVAL LICENSING LLC v. AOL, INC. 13

the claim is still indefinite if a person of ordinary skill in 

the art cannot translate the definition into meaningfully 

precise claim scope.”).

B 

The patents’ “unobtrusive manner” phrase is highly 

subjective and, on its face, provides little guidance to one 

of skill in the art. Although the patented invention is a 

system that displays content, the claim language offers no 

objective indication of the manner in which content images are to be displayed to the user. As the district court 

observed, “whether something distracts a user from his 

primary interaction depends on the preferences of the 

particular user and the circumstances under which any 

single user interacts with the display.” Interval, 2013 WL 

792791, at *4. The lack of objective boundaries in the 

claim language is particularly troubling in light of the 

patents’ command to read “the term ‘image’ . . . broadly to 

mean any sensory stimulus that is produced from the set 

of content data,” including sounds and video. ’652 patent, 

6:60–64. The patents contemplate a variety of stimuli 

that could impact different users in different ways. As we 

have explained, a term of degree fails to provide sufficient 

notice of its scope if it depends “on the unpredictable 

vagaries of any one person’s opinion.” Datamize, 417 F.3d 

at 1350. 

Where, as here, we are faced with a “purely subjective” claim phrase, we must look to the written description for guidance. Id. at 1351; see also Chimie v. PPG 

Indus., Inc., 402 F.3d 1371, 1377 (Fed. Cir. 2005). We 

find, however, that sufficient guidance is lacking in the 

written description of the asserted patents.

i 

Interval contends that the “unobtrusive manner” 

phrase is sufficiently defined through its relationship to 

one of the two primary embodiments. The phrase, Inter-
14 INTERVAL LICENSING LLC v. AOL, INC. 

val maintains, is tied exclusively to the wallpaper embodiment, thus informing those of skill in the art that “unobtrusive” has only a spatial meaning in the context of the 

patents. “Because the district court failed to appreciate 

that the language describing display ‘in an unobtrusive 

manner that does not distract a user’ is tied to specific 

type of display described in the specification,” Interval 

argues, the district court “improperly divorced its analysis 

from the context of the written description and incorrectly 

focused on irrelevant hypotheticals . . . .” Appellant’s Br. 

23. 

We do not agree with Interval that it is reasonably 

clear that the “unobtrusive manner” language is tied to a 

specific type of display. Although Interval identifies 

portions of the specification that appear to use the “unobtrusive manner” phrase in conjunction with the wallpaper 

embodiment, see ’652 patent, 2:12–19, 13:11–14, other 

portions of the specification suggest that the phrase may 

also be tied to the screen saver embodiment. 

According to one aspect of the invention, an attention manager engages the peripheral attention of 

a person in the vicinity of a display device of an 

apparatus by acquiring one or more sets of content data from a content providing system and selectively displaying on the display device, in an 

unobtrusive manner that does not distract a 

user of the apparatus from a primary interaction with the apparatus, an image or images 

generated from the set of content data. According to a further aspect of the invention, the 

selective display of the image or images begins automatically after detection of an idle 

period of predetermined duration (the 

“screen saver embodiment”). This aspect can 

be implemented, for example, using the screen 

saver API (application program interface) that is 

part of many operating systems. According to 
INTERVAL LICENSING LLC v. AOL, INC. 15

another further aspect of the invention, the 

selective display of an image or images occurs while the user is engaged in a primary 

interaction with the apparatus, which primary interaction can result in the display of 

an image or images in addition to the image 

or images generated from the set of content 

data (the “wallpaper embodiment”).

Id. at 3:11–31 (emphases added). 

The specification here suggests that possibly both the 

screen saver and wallpaper embodiments are “further 

aspects” of an attention manager that displays content “in 

an unobtrusive manner that does not distract a user of 

the apparatus from a primary interaction with the apparatus.” Although Interval disputes this reading, we find 

that the specification is at best muddled, leaving one 

unsure of whether the “unobtrusive manner” phrase has 

temporal dimensions as well as spatial dimensions. The 

hazy relationship between the claims and the written 

description fails to provide the clarity that the subjective 

claim language needs. See Datamize, 417 F.3d at 1352 

(holding claim term “aesthetically pleasing” indefinite 

because, even though the preferred embodiment provided 

“examples of aesthetic features of screen displays that can 

be controlled by the authoring system,” the specification 

did not indicate “what selection of these features would be 

‘aesthetically pleasing’”); In re Hammack, 427 F.2d 1378, 

1381–82 (C.C.P.A. 1970) (finding claims invalid for indefiniteness where claims “serv[ed] as a shadowy framework

upon which are located words lacking in precise referents 

in the specification” (internal quotations omitted)). 

The prosecution history further illustrates the difficulty in pinning down the relationship between the written description and the “in an unobtrusive manner that 

does not distract the user” claim phrase. The statements 

of Interval, and the responses of the USPTO, reflect 
16 INTERVAL LICENSING LLC v. AOL, INC. 

considerable uncertainty about which embodiments were 

tied to the “unobtrusive manner” language. During 

prosecution in 1998, Interval relied on a different reading

than the one it offers now, stating that “[t]he display of 

images in an unobtrusive manner in a system as recited 

in Claim 1 can be implemented by, for example, displaying images during an inactive period (e.g., when the user 

has not interacted with the apparatus for a predetermined period of time) of a primary interaction with the 

apparatus (the ‘screensaver embodiment’).” J.A. 985. 

Interval points out, however, that the examiner appeared 

not to share Interval’s initial understanding: later in the 

prosecution, the examiner discussed the “unobtrusive 

manner” limitation in conjunction with the wallpaper 

embodiment but not the screen saver embodiment. J.A. 

1073. 

The USPTO expressed a similar understanding during reexaminations of the ’652 and ’314 patents, with 

examiners finding that the specification links the “unobtrusive manner” language to the wallpaper embodiment, 

excluding the screensaver embodiment. See J.A. 1090–91, 

1311. But in a recent decision addressing the scope and 

validity of the ’314 patent, the Patent Trial and Appeal 

Board disagreed with the examiner. Apple, Inc. v. Interval Licensing LLC, No. 2013-005424, 2014 WL 1322685 

(Patent Tr. & App. Bd. Apr. 1, 2014).7 The Board con7 The Board’s decision was a response to an appeal 

from an inter partes reexamination. Per 37 C.F.R. 

§ 1.906, the Board was limited to the question of whether 

the challenged claims should be rejected on the basis of 

prior art patents or printed publications. Neither the 

examiner nor the Board could address claim definiteness. 

The claims were given “their broadest reasonable construction” during reexamination. In re Am. Acad. Of Sci. 

Tech Ctr., 367 F.3d 1359, 1364 (Fed. Cir. 2004). 

 
INTERVAL LICENSING LLC v. AOL, INC. 17

cluded that, in light of “the ambiguous nature” of the 

specification, “the claim term ‘unobtrusive manner’ includes the screensaver embodiment.” Id. at *7.8 

After reviewing the specification and prosecution history, we find that the “unobtrusive manner” phrase has 

too uncertain a relationship to the patents’ embodiments. 

Contrary to Interval’s suggestion, the wallpaper embodiment does not provide a reasonably clear and exclusive 

definition, leaving the facially subjective claim language 

without an objective boundary. 

ii

In the alternative, Interval suggests that if we are not 

persuaded that the wallpaper embodiment defines the 

“unobtrusive manner” phrase, then we must at least 

adopt a “narrow example” from the specification. That 

example lies in the Summary of the Invention, which 

explains that information can be presented “in an unobtrusive manner that does not distract the user from the 

primary interaction with the apparatus (e.g., the information is presented in areas of a display screen that are 

not used by displayed information associated with the 

primary interaction with the apparatus).” ’652 patent, 

2:15–19 (emphasis added).

We recognize that a patent which defines a claim 

phrase through examples may satisfy the definiteness 

requirement. See, e.g., Enzo Biochem, 599 F.3d at 1336

8 At the hearing before the Board, counsel for Interval acknowledged the lack of clarity in column 3 of the 

specification: “I would say in this summary location 

within the specification [the drafters] were a little bit less 

precise, a little bit sloppy here . . . it might seem less 

precise or even possibly contradictory. . . . My point is 

simply that at best it’s ambiguous.” Id. at *6 (internal 

citations omitted). 

 
18 INTERVAL LICENSING LLC v. AOL, INC. 

(holding that “not interfering substantially” is sufficiently 

definite because one of skill in the art could use “the 

examples in the specification to determine whether interference with hybridization is substantial”). In this case, 

however, we decline to cull out a single “e.g.” phrase from 

a lengthy written description to serve as the exclusive 

definition of a facially subjective claim term. See Nautilus, 134 S. Ct. at 2130 (disfavoring “post hoc” efforts to 

“ascribe some meaning to a patent’s claims”). 

Had the phrase been cast as a definition instead of as 

an example—if the phrase had been preceded by “i.e.” 

instead of “e.g.”—then it would help provide the clarity 

that the specification lacks. But as the specification is 

written, we agree with the district court that a person of 

ordinary skill in the art would not understand the “e.g.” 

phrase to constitute an exclusive definition of “unobtrusive manner that does not distract a user.” See Interval, 

2013 WL 792791, at *4. With this lone example, a skilled 

artisan is still left to wonder what other forms of display 

are unobtrusive and non-distracting. What if a displayed 

image takes up 20% of the screen space occupied by the 

primary application with which the user is interacting? Is 

the image unobtrusive? The specification offers no indication, thus leaving the skilled artisan to consult the “unpredictable vagaries of any one person’s opinion.” See 

Datamize, 417 F.3d at 1350. Such ambiguity falls within 

“the innovation-discouraging ‘zone of uncertainty’ against 

which [the Supreme Court] has warned.” Nautilus, 134 

S. Ct. at 2130 (internal citation omitted). 

In sum, the “unobtrusive manner that does not distract a user” phrase, when viewed in light of the specification and prosecution history, fails to “inform those skilled 

in the art about the scope of the invention with reasonable certainty.” See id. at 2129. The claims that depend on 

that phrase are thus invalid for indefiniteness.
INTERVAL LICENSING LLC v. AOL, INC. 19

II. Claim Construction

We review claim construction de novo. Lighting Ballast Control LLC v. Philips Elecs. N. Am. Corp., 744 F.3d 

1272, 1276–77 (Fed. Cir. 2014) (en banc); Cybor Corp. v. 

FAS Techs., Inc., 138 F.3d 1448, 1451 (Fed. Cir. 1998) (en 

banc). The words of a claim “are generally given their 

ordinary and customary meaning,” which is the “meaning 

that the term would have to a person of ordinary skill in 

the art in question at the time of the invention.” Phillips 

v. AWH Corp., 415 F.3d 1303, 1312–13 (Fed. Cir. 2005)

(en banc) (internal citations omitted). Claim language 

must be viewed in light of the specification, which is “the 

single best guide to the meaning of a disputed term.” Id.

at 1315 (quoting Vitronics Corp. v. Conceptronic, Inc., 90 

F.3d 1576, 1582 (Fed. Cir. 1996)). In addition to consulting the specification, we may also consider the prosecution history and any relevant extrinsic evidence. Id. at 

1315–17. 

A. Construction of “Attention Manager”

As discussed in the Background, supra, the phrase 

“attention manager” appears in claims 15–18 of the ’652 

patent. In its claim construction order, the district court 

adopted the Defendants’ proposed construction: “a system 

that displays images to a user either when the program 

detects that the user is not engaged in a primary interaction or as a background of the computer screen.” Interval, 

2013 WL 792791, at *11. The court explained that it 

relied on “the only description in the specification that 

gives objective boundaries to the scope of this limitation: 

the ‘screensaver’ and ‘wallpaper’ embodiments.” Id.

In contrast to the “in an unobtrusive manner that 

does not distract a user” phrase, there is no uncertainty 

about the definitional relationship between the claim 

term “attention manager” and the written description. 

The patented invention is a self-coined “attention manager.” No one disputes that the “attention manager” is 
20 INTERVAL LICENSING LLC v. AOL, INC. 

defined by all of the disclosed embodiments. What is in 

dispute, and what we must consider in reviewing the 

construction of “attention manager,” is whether the 

district court read the embodiments too narrowly and 

thus improperly limited the scope of the claim term. 

Interval proposes modifying the claim construction as 

follows: 

a system that displays images to a user either 

when the program detects that the user is not engaged in a primary interaction or as a background 

of the computer screen an area of the display 

screen that is not substantially used by the 

user’s primary activity. 

See Appellant’s Br. 53. 

With regard to the first proposed modification—the 

removal of “the program detects that” phrase—Interval 

argues that the district court mistakenly limited the 

screen saver to a single mode of operation. Interval notes 

that the specification describes two ways of activating the 

screen saver: (1) through the detection of an idle period 

or, alternatively, (2) through direct user activation. See

’652 patent, 9:21–36. In response, the Defendants suggest 

that the system still “detects” user activation even in the 

alternative embodiment, and that the district court’s 

inclusion of “detects” is thus consistent with the patents’ 

description of the screen saver. Although the Defendants’ 

reading is plausible, we think that Interval’s reading 

better conforms to the distinction drawn between “detection” and “user-activation” in the written description. We 

therefore agree with Interval that the phrase “the program detects that” should be removed from the construction.

With regard to the second proposed modification—the 

replacement of “a background of the computer screen” 

with “as an area of the display screen that is not substan-
INTERVAL LICENSING LLC v. AOL, INC. 21

tially used by the user’s primary activity”—Interval 

argues that its change is faithful to a “lexicographical 

definition” in the specification of the ’652 patent. Appellant’s Br. 53 (citing Phillips, 415 F.3d at 1321). Interval 

faults the district court for basing its construction on a 

general definition of “wallpaper” in the specification. See

’652 patent, 1:50–52 (describing wallpaper as “a pattern 

generated in the background portions on a computer 

display”). Instead, Interval urges, the construction should 

be based on an express definition of “wallpaper embodiment”:

According to another further aspect of the invention, the selective display of an image or images 

occurs while the user is engaged in a primary interaction with the apparatus, which primary interaction can result in the display of an image or 

images in addition to the image or images generated from the set of content data (the “wallpaper 

embodiment”).

Id. at 3:25–31. 

We agree with Interval that the wallpaper embodiment of the attention manager should not be strictly 

limited to the “background” of a computer screen, and we 

agree that the specification’s description of the embodiment should inform our construction. The district court’s 

construction suggests that displayed images must be 

integrated into the background display, similar to the 

“patterns” of the traditional wallpaper described in the 

background of the invention. See id. at 1:50–52. But the 

patents’ description of the wallpaper embodiment supports a broader reading. The patent describes the embodiment as making use of unused spatial capacity—that is, 

space in the display not used by the user’s primary interaction. See id. at 3:25–31, 6:45–51. The specification does 

not indicate that the images must be displayed as part of 

the background of the display device.
22 INTERVAL LICENSING LLC v. AOL, INC. 

We note, however, that Interval’s proposed modification (“an area of the display screen that is not substantially used by the user’s primary activity”) is not taken 

directly from the cited “lexicography.” Rather, the proposed language appears to be Interval’s interpretation of 

where the images will be displayed while the user is 

engaged in a primary interaction. Based on our reading 

of the specification, the attention manager is better 

construed as displaying images in areas “not used”—

instead of “not substantially used”—by the user’s primary 

activity. The specification consistently describes how the 

attention manager makes use of “unused capacity.” 

Moreover, the specification twice contrasts a user’s “primary interaction with the apparatus” with the display of 

information in areas “not used” by the information associated with the primary interaction. See id. at 2:15–19, 

6:43–45. The phrase “not substantially used,” by contrast, 

appears nowhere in the specification. 

In sum, with the exception of the addition of the word 

“substantially,” we agree with Interval’s proposed construction of “attention manager.” Accordingly, we adopt 

the following construction: “a system that displays images to a user either when the user is not engaged in a 

primary interaction or in an area of the display screen 

that is not used by the user’s primary activity.” 

B. Construction of “Instructions”

The district court construed “instructions” as “a 

statement in a programming language that specifies a 

function to be performed by a system.” Interval, 2013 WL 

792791, at *15–16. Although the district court’s construction of “instructions” was not dispositive with respect to 

the final judgment of invalidity and non-infringement, 

Interval asks us to review that construction now. Specifically, Interval asks us to clarify that “instructions,” in the 

context of the patents, “may encompass ‘data’” and “need 
INTERVAL LICENSING LLC v. AOL, INC. 23

not be written ‘in a programming language.’” Appellant’s 

Br. 61–62.

In the interest of judicial economy, we have the discretion to review a non-dispositive claim construction if 

we believe that the construction may become important 

on remand. See Deere & Co. v. Bush Hog, LLC, 703 F.3d 

1349, 1357 (Fed. Cir. 2012); Advanced Software Design 

Corp. v. Fiserv, Inc., 641 F.3d 1368, 1378 (Fed. Cir. 2011). 

Because we are vacating the judgment of noninfringement as to claims 15–18 of the ’652 patent, and 

because those claims include the term “instructions,” we 

take this opportunity to address the claim construction of 

that term.

During claim construction, Interval argued that “instructions” should be construed to cover “data related to 

the accomplishment of a function.” J.A. 27. Relying 

principally on the distinction between “instructions” and 

“data” in the specification, the district court refused to 

adopt Interval’s construction. See Interval, 2013 WL 

792791, at *15–16. We share the district court’s reading. 

Interval notes that the specification refers to certain 

“instructions” as “functional components,” ’652 patent, 

14:49–53, which may be represented by “data.” Id. at 

14:53–57 (“Each of the functional components are represented by a set of instructions and/or data. In particular,

each of the instructions may include, if appropriate, data 

related to accomplishment of the functions associated 

with the set of instructions . . . .”). Although Interval 

reads the cited portion of the specification as showing that 

data alone can constitute an “instruction,” we read the 

specification as maintaining a distinction between “instructions” and “data.” An instruction “may . . . include

data,” not consist of data; the instruction is not the data 

itself. As the district court observed, “[i]f ‘data’ is a type 

of ‘instructions,’ then the phrase ‘instructions and/or data’ 

would not make sense.” Interval, 2013 WL 792791, at 
24 INTERVAL LICENSING LLC v. AOL, INC. 

*16. Moreover, the district court’s reading is consistent 

with extrinsic evidence suggesting that the distinction 

between “instructions” and “data” is widely recognized in 

the field of art. See J.A. 845 (“The distinction between 

program (instructions) and data is a fundamental one in 

computing.” (quoting Oxford Dictionary of Computing)). 

For these reasons, we decline Interval’s invitation to call 

into question the distinction between “instructions” and 

“data” in the district court’s construction. 

As for Interval’s concerns regarding the “in a programming language” phrase, we find that a modification 

to the construction is necessary. Although the district 

court carefully explained why the intrinsic evidence 

supported the exclusion of the word “data” from its construction, the court offered no direct explanation for its 

inclusion of the “in a programming language” limitation. 

The patents’ specification does not indicate that instructions must take the form of programming language 

statements. The source of that limitation is the IEEE 

Standard Dictionary of Electrical and Electronics Terms

(6th ed. 1996) (“IEEE Dictionary”), which the Defendants 

relied on for their proposed construction. See J.A. 419, 

484. 

The IEEE Dictionary includes five different definitions of “computer instruction,” with two definitions 

specifically directed towards “software” computer instructions. The Defendants based their construction on one of 

those two definitions: “A statement in a programming 

language, specifying an operation to be performed by a 

computer and the addresses or values of the associated 

operands; for example, Move A to B.” Id. at 484. The 

second definition, which the Defendants did not reference, 

reads: “Loosely, any executable statement in a computer 

program.” Id. 

We have recognized that technical dictionaries “can 

assist the court in determining the meaning of particular 
INTERVAL LICENSING LLC v. AOL, INC. 25

terminology to those of skill in the art of the invention.” 

Phillips, 415 F.3d at 1318. At the same time, we have 

cautioned against relying on dictionary definitions at the 

expense of a fair reading of the claims, which must be 

understood in light of the specification. See id. at 1321–

22. Here, considering that the patents’ specification does 

not use “instructions” in relation to “programming language statements,” we find that the broader dictionary 

definition (“any executable statement in a computer 

program”) is preferable.

Moreover, we share Interval’s concern that the “in a 

programming language” limitation will breed unnecessary 

uncertainty about whether “instructions” may take the 

form of object code. As Interval notes, one could argue 

that object code—which may consist of strings of 1’s and 

0’s—is not a “programming language.” The IEEE Dictionary, however, defines “object code” as “[c]omputer 

instructions and data definitions in a form output by an 

assembler or a compiler.” 

In sum, the extrinsic source on which the district 

court relied suggests a broader construction of “instructions” than the court adopted. We conclude that a construction without the “in a programming language” 

phrase is both simpler and more accurate. Accordingly, 

we adopt the following construction: “a statement that 

specifies a function to be performed by a system.”

CONCLUSION

We hold that the claim phrase “in an unobtrusive 

manner that does not distract a user” is indefinite under 

35 U.S.C. § 112, ¶ 2. Therefore, the district court correctly granted judgments of invalidity as to claims 4–8, 11, 

34, and 35 of the ’652 patent and claims 1–4 and 7–15 of 

the ’314 patent. However, the district court erred in 

granting judgments of non-infringement as to claims 15–

18 of the ’652 patent based on the erroneous claim construction of “attention manager.” We therefore affirm the 
26 INTERVAL LICENSING LLC v. AOL, INC. 

judgments of invalidity, vacate the judgments of noninfringement, and remand to the district court for further 

proceedings consistent with this opinion.

AFFIRMED–IN–PART, VACATED–IN–PART, AND 

REMANDED

COSTS

Each party shall bear its own costs.