United States Court of Appeals 

for the Federal Circuit ______________________ 

TRITON TECH OF TEXAS, LLC,

Plaintiff-Appellant,

v.

NINTENDO OF AMERICA, INC.,

Defendant-Appellee.

______________________ 

2013-1476

______________________ 

Appeal from the United States District Court for the 

Western District of Washington in No. 13-CV-0157, Judge 

Richard A. Jones.

______________________ 

Decided: June 13, 2014 

______________________ 

JAMES F. MCDONOUGH, III, Heninger Garrison Davis, 

LLC, of Atlanta, Georgia, argued for plaintiff-appellant. 

With him on the brief were JACQUELINE KNAPP BURT; and 

TIMOTHY C. DAVIS, of Birmingham, Alabama. 

GRANT KINSEL, Perkins Coie, LLP, of Los Angeles, 

California, argued for defendant-appellee. With him on 

the brief were JOSEPH HAMILTON, of Los Angeles, California; JONATHAN L. MCFARLAND, of Seattle, Washington; 

and DAN L. BAGATELL, of Phoenix, Arizona.

______________________ 
2 TRITON TECH OF TEXAS, LLC v. NINTENDO OF AMERICA, INC. 

Before MOORE, REYNA, and HUGHES, Circuit Judges.

MOORE, Circuit Judge. 

Triton Tech of Texas, LLC (“Triton”) appeals from the 

district court’s judgment that the means-plus-function 

term “integrator means” renders the asserted claims of 

Triton’s U.S. Patent No. 5,181,181 invalid for indefiniteness. We affirm. 

BACKGROUND

Triton sued Nintendo of America, Inc. (“Nintendo”), 

alleging that the Wii RemoteTM used in combination with 

a related accessory infringes the ’181 patent. The ’181 

patent is directed to an input device for a computer. ’181 

patent col. 1 ll. 9–10. It discloses that a user can communicate with a computer by moving the input device—

much like using a mouse, but in three dimensions. Id. col. 

2 ll. 50–67. The input device sends commands to the 

computer based on the input device’s three-dimensional 

position, attitude (i.e., orientation), and motion. Id. 

Abstract. For example, a user may be able to manipulate 

an object that is represented graphically on the computer 

by moving the input device in a manner in which the user 

wishes to manipulate the object. Id. col. 1 ll. 15–22.

The input device includes components for determining 

its position, attitude, and motion. In the preferred embodiment, these components include three accelerometers 

and three rotational rate sensors for measuring linear 

acceleration along, and rotational velocity about, three 

orthogonal axes. Id. col. 3 ll. 3–29, Fig. 1(d). The preferred embodiment also includes a conventional microprocessor that is programmed to periodically read and 

numerically integrate over time digitized acceleration and 

rotational rate values to calculate the position, attitude, 

and motion values for the input device. Id. col. 7 ll. 15–
TRITON TECH OF TEXAS, LLC v. NINTENDO OF AMERICA, INC. 3

25. The ’181 patent does not further explain how the 

numerical integration is performed, only that it is performed in a “conventional manner.” Id. col. 10 ll. 7–9. 

The input device then outputs these values to the computer to facilitate the user’s interaction with the computer. Id. col. 11 ll. 14–42.

Claim 4 is representative of the asserted claims: 

An input device for providing information to a 

computing device, comprising: . . . 

a first acceleration sensor . . . ; a second acceleration sensor . . . ; a third acceleration sensor [each 

producing analog acceleration sensor signals]; 

a first rotational rate sensor . . . ; a second rotational rate sensor . . . ; a third rotational rate sensor . . . ; . . .

an analog-to-digital converter associated with said 

input device which quantizes said analog acceleration sensor signals to produce digital acceleration 

sensor values;

a first-in, first-out buffer memory which temporarily stores said digital acceleration sensor values from said analog-to-digital converter in 

sequential order for later processing;

integrator means associated with said input device

for integrating said acceleration signals over time

to produce velocity signals for linear translation 

along each of . . . first, second and third axes; and 

communication means associated with said input 

device for communicating information between 

said input device and said computing device. 

Id. col. 12 l. 42 – col. 13 l. 15 (emphases added).
4 TRITON TECH OF TEXAS, LLC v. NINTENDO OF AMERICA, INC. 

Each asserted claim recites an “integrator means.” 

The district court held that this term rendered the asserted claims indefinite. Triton Tech of Texas, LLC v. Nintendo of Am., Inc., C.A. No. 13-cv-0157 (W.D. Wash. June 

4, 2013), ECF No. 153 (“Claim Construction Order”). It

determined that the corresponding structure for performing the recited integrating function was a “conventional 

microprocessor having a suitably programmed read-only 

memory.” Id. at 14. It found that the ’181 patent did not 

disclose any algorithm for performing the recited integrating function. Id. at 15–16. It noted that the ’181 patent 

broadly discloses using “numerical integration,” but 

determined that this alone was not a sufficient disclosure

because “‘[n]umerical integration’ . . . is not a single 

algorithm, but rather a whole class of algorithms that can 

be used to calculate definite integrals . . . .” Id. at 16. The 

district court thus concluded that the asserted claims 

were indefinite.1 Id. at 15–16 (citing Aristocrat Techs. 

Austr. Pty Ltd. v. Int’l Gaming Tech., 521 F.3d 1328, 1334 

(Fed. Cir. 2008)). Triton appeals. We have jurisdiction 

under 28 U.S.C. § 1295(a)(1). 

DISCUSSION

We review de novo a district court’s decision regarding 

indefiniteness. Function Media, L.L.C. v. Google Inc., 708 

F.3d 1310, 1316 (Fed. Cir. 2013). Section 112 ¶ 6 allows a 

patentee to express an element of a claim as a means for 

1 The district court similarly determined that “processing means,” recited only in dependent claim 13, was 

indefinite and also construed several claim terms adversely to Triton. On appeal, Triton also challenges the indefiniteness of “processing means” and the district court’s 

claim construction. In light of our affirmance of indefiniteness based on “integrator means,” we need not reach 

these issues. 

 
TRITON TECH OF TEXAS, LLC v. NINTENDO OF AMERICA, INC. 5

performing a specified function. 35 U.S.C. § 112 ¶ 6 

(2006). In exchange for using this form of claiming, the 

patent specification must disclose with sufficient particularity the corresponding structure for performing the 

claimed function and clearly link that structure to the 

function. Ibormeith IP, LLC v. Mercedes-Benz USA, LLC, 

732 F.3d 1376, 1379 (Fed. Cir. 2013). If the function is 

performed by a general purpose computer or microprocessor, then the specification must also disclose the algorithm that the computer performs to accomplish that 

function. Aristocrat, 521 F.3d at 1333. Failure to disclose 

the corresponding algorithm for a computer-implemented 

means-plus-function term renders the claim indefinite. 

Ergo Licensing LLC v. CareFusion 303, Inc., 673 F.3d 

1361, 1363 (Fed. Cir. 2012). 

Triton concedes that the structure corresponding to 

“integrator means” is a conventional microprocessor, and 

contends that the ’181 patent discloses an algorithm for 

performing the integrating function with enough specificity to render the claims discernible to a person of ordinary 

skill. First, Triton argues that merely using the phrase 

“numerical integration” is sufficient disclosure of an 

algorithm because numerical integration was well known 

to those skilled in the art. Second, Triton argues that the

’181 patent discloses a two-step algorithm for accomplishing the integrating function: (1) sampling measured 

values over time and (2) accumulating by continuously

summing areas defined by the sampled values. Triton

asserts that the ’181 patent discloses the sampling step as 

acquiring instantaneous values from the different sensors, 

formatting them to digital values, and then storing them 

for further processing. Appellant’s Br. 20–21 (citing ’181 

patent col. 3 ll. 30–38, col. 9 ll. 2–6, 28–37, 49–59). Triton 

contends that the ’181 patent discloses the accumulating 

step as “clearing all numeric integration accumulators” 

and continually performing numerical integration to 
6 TRITON TECH OF TEXAS, LLC v. NINTENDO OF AMERICA, INC. 

compute the position and attitude values. Id. at 21–22 

(citing ’181 patent col. 7 l. 65 – col. 8 l. 3, col. 10 ll. 51–62, 

col. 7 ll. 21–36, col. 8 ll. 11–12). 

We affirm the district court’s determination that the 

asserted claims of the ’181 patent are indefinite because 

the specification does not disclose an algorithm for performing the claimed integrating function of the “integrator means.” It is certainly true that an algorithm can be 

expressed in many forms, including flow charts, a series of 

specific steps, mathematical formula, prose, and so on. 

Finisar Corp. v. DirecTV Grp., Inc., 523 F.3d 1323, 1340 

(Fed. Cir. 2008). However, merely using the term “numerical integration” does not disclose an algorithm—i.e., 

a step-by-step procedure—for performing the claimed 

function. Ergo Licensing, 673 F.3d at 1365 (“Even described in prose, an algorithm is still a step-by-step procedure for accomplishing a given result.”) (quotations 

omitted). As the district court correctly determined, 

numerical integration is not an algorithm but is instead 

an entire class of different possible algorithms used to 

perform integration. Claim Construction Order at 16. 

Disclosing the broad class of “numerical integration” does 

not limit the scope of the claim to the “corresponding 

structure, material, or acts” that perform the function, as 

required by section 112. Indeed, it is hardly more than a 

restatement of the integrating function itself. Disclosure 

of a class of algorithms “that places no limitations on how 

values are calculated, combined, or weighted is insufficient to make the bounds of the claims understandable.” 

Ibormeith, 732 F.3d at 1382. 

The fact that various numerical integration algorithms may have been known to one of ordinary skill in 

the art does not rescue the claims. “[A] bare statement 

that known techniques or methods can be used does not 

disclose structure.” Biomedino, LLC v. Water Techs. 

Corp., 490 F.3d 946, 953 (Fed. Cir. 2007); see also ePlus, 
TRITON TECH OF TEXAS, LLC v. NINTENDO OF AMERICA, INC. 7

Inc. v. Lawson Software, Inc., 700 F.3d 509, 519 (Fed. Cir. 

2012). The district court correctly recognized that 

“[a]lthough a person of skill in the art might be able to 

choose an appropriate numerical integration algorithm 

and program it onto a microprocessor, the [p]atent discloses no algorithm at all.” Claim Construction Order at 

16. We thus conclude that the district court correctly 

found that the ’181 patent’s disclosure of “numerical 

integration” does not satisfy the disclosure requirement of 

section 112 ¶ 6; “numerical integration” is not an algorithm. 

We hold that Triton has waived its second argument 

that the ’181 patent discloses a two-step algorithm that 

consists of sampling and accumulating. Triton did not 

make this argument to the district court. Instead, it 

argued that the corresponding structure for “integrator 

means” is a conventional microprocessor “that performs 

integration.” Plaintiff’s Opening Claim Construction 

Brief, Triton Tech of Texas, LLC v. Nintendo of Am. Inc., 

No. 10-cv-328, at 14 (E.D. Tex. Nov. 30, 2012), ECF No. 

115.2 It explained that “[the position, velocity, and attitude values] are computed and numerically integrated in 

a ‘known manner,’” and that “[n]umerical integration 

describes the ways in which a numerical value is reached 

from the integration of definite integrals.” Plaintiff’s 

Reply Claim Construction Brief, Triton Tech of Texas, 

LLC v. Nintendo of Am. Inc., No. 10-cv-328, at 7 (E.D. 

Tex. Dec. 21, 2012), ECF No. 122. It did not argue that 

the ’181 patent discloses a two-step numerical algorithm. 

It argued only that the term “numerical integration” was 

sufficient. 

2 This case was transferred from the Eastern District of Texas to the Western District of Washington after 

the parties finished their claim construction briefing. 

 
8 TRITON TECH OF TEXAS, LLC v. NINTENDO OF AMERICA, INC. 

To the extent that Triton now argues that one of skill 

in the art would have understood the bare disclosure of 

“numerical integration” as disclosing a particular two-step 

algorithm, we find that it also waived that argument. 

Triton argued to the district court that “numerical integration describes the ways in which a numerical value is 

reached from . . . integration,” that “the method of numerical integration would [have been] obvious” and that the 

specification disclosed “numerical integration” such that 

“one of ordinary skill in the art could identify a preferred 

mathematical equation with which to perform the function of integrating.” Id. at 7–8. Thus, at best, Triton 

argued to the district court that one of skill in the art 

would have been able to identify a preferred integration 

algorithm because different methods for performing 

numerical integration were well known. Triton did not 

argue below that one of skill in the art would have understood the disclosure of “numerical integration” as describing a particular two-step algorithm. It cannot make that 

argument for the first time on appeal. 

In exchange for expressing “integrator means” as a 

means-plus-function term, Triton was required to disclose 

an algorithm for performing the claimed integrating 

function. Because it did not do so, the asserted claims are 

indefinite. 

CONCLUSION

We affirm the district court’s judgment that the asserted claims of the ’181 patent are invalid for indefiniteness.

AFFIRMED