Richard Gramm, Reaper Solutions LLC, Fka Headsight, Inc. v. Deere & Company

United States Court of Appeals
for the Federal Circuit
______________________
RICHARD GRAMM, REAPER SOLUTIONS LLC,
FKA HEADSIGHT, INC.,
Plaintiffs-Appellants
v.
DEERE & COMPANY,
Defendant-Appellee
______________________
2024-1598
______________________
Appeal from the United States District Court for the
Southern District of Iowa in No. 3:22-cv-00010-RGE-SBJ,
Judge Rebecca Goodgame Ebinger.
______________________
Decided: March 11, 2026
______________________
CHRISTOPHER A. YOUNG, Larkin Hoffman Daly & Lind-
gren, Ltd., Minneapolis, MN, argued for plaintiffs-appel-
lants. Also represented by J OHN C OTTER, T HOMAS J OHN
O PPOLD.
L AURA A. L YDIGSEN, Crowell & Moring LLP, Chicago,
IL, argued for defendant-appellee. Also represented by
J UDY HE, MARY L AF LEUR, J EFFRY M. N ICHOLS .
______________________
Before L OURIE, REYNA , and CUNNINGHAM , Circuit Judges.
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GRAMM v. DEERE & COMPANY 2
REYNA, Circuit Judge.
Reaper Solutions, LLC and Richard Gramm appeal an
order of the United States District Court for the Southern
District of Iowa concluding the asserted claims of U.S. Pa-
tent No. 6,202,395 are invalid as indefinite and entering a
judgment in favor of Deere based on that conclusion. We
reverse the district court’s indefiniteness conclusion and
judgment of invalidity and remand for further proceedings
consistent with this opinion.
I. BACKGROUND
Richard Gramm is the sole inventor and owner of U.S.
Patent No. 6,202,395 (the “’395 patent”), which he licenses
exclusively to Reaper Solutions, LLC.1 The ’395 patent is
directed to an apparatus for maintaining the header of a
crop harvester a desired height above the ground as the
harvester traverses a field. J.A. 45 at 1:10–13. Figure 1 of
the ’395 patent, reproduced below, depicts an embodiment
of a harvester (10) including a header (12).
1 Reaper Solutions, LLC was formerly known as
Headsight, Inc.
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GRAMM v. DEERE & COMPANY 3
J.A. 41 at Fig. 1.
Gramm and Reaper Solutions, LLC (collectively,
“Reaper”) sued Deere & Company (“Deere”) in district court
in 20142 alleging that certain Deere header sensor kits in-
fringed the ’395 patent. Deere then challenged the ’395 pa-
tent in inter partes review, after which (including this
court’s appellate review in Deere & Co. v. Gramm,
842 F. App’x 628, 631 (Fed. Cir. 2021)) only independent
claim 12 and certain of its dependents remained asserted.
Claim 12 recites in relevant part:
12. Apparatus for maintaining a non-cut crop
header in a crop harvester a designated height
above the soil as the crop harvester traverses a
field, said apparatus comprising:
***
control means coupled to said header and said an-
gular deflection sensing means and responsive to
said first signal for raising or lowering the
header in accordance with said first signal in
maintaining the header a designated height
above the soil, wherein said flexible arm and an-
gular deflection sensing means are attached to a
head housing disposed on a forward portion of said
combine and said head housing is comprised of pol-
yurethane and includes a metal tip and a mounting
bracket for attaching said metal tip to a forward
end of said head housing, and wherein said mount-
ing bracket further couples said flexible arm to a
forward end of said head housing.
J.A. 48 at 8:22–61 (emphases added).
2 Reaper initially filed suit in the United States Dis-
trict Court for the Northern District of Indiana, and the
case was later transferred to the Southern District of Iowa.
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GRAMM v. DEERE & COMPANY 4
During claim construction, Deere and Reaper (the “par-
ties”) disputed the meaning of “control means” in claim 12.
The parties agreed that “control means” is a
means-plus-function limitation that invokes 35 U.S.C.
§ 112(f).3 Reaper identified, and Deere did not dispute,
that the claimed function associated with control means is
“raising and lowering the header . . . a designated height
above the soil.” And the parties agreed that the corre-
sponding structure described in the ’395 patent specifica-
tion is the “controller interface 18,” “head controller 20,”
and “hydraulic control system 38” features together in com-
bination. J.A. 1196, 1944, 3193. The parties also agreed
that those features are described in the specification at col-
umn 3, lines 33–52:
The corn head height sensor 14 is connected by a
suitable electrical means to a controller interface
18 and a head controller 20 within combine 10. In
response to the detected height of the corn header
12, head controller 20 provides suitable elec-
trical control signals to an electrically actu-
ated, hydraulic control system 38 for
controlling the lateral position of the corn
header 12 as well as its height above the
ground, or soil, 16 as the combine 10 traverses a
field in the direction of arrow 56. Head controller
20 is conventional in design and operation
and, in general, receives an analog electrical signal
from the controller interface 18 and outputs an an-
alog signal to the hydraulic control system
3 The ’395 patent issued in 2001, before the Leahy-
Smith America Invents Act (“AIA”) went into effect in 2013.
Therefore, the “control means” limitation is governed by
pre-AIA § 112 ¶6. As the parties did in briefing, we refer
herein to AIA statute § 112(f), which uses the same lan-
guage as the pre-AIA statute.
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GRAMM v. DEERE & COMPANY 5
38. . . . In a specific embodiment of the present
invention, head controller 20 is as incorpo-
rated in a Deere combine, while controller inter-
face 18 is available from May-Wes.
J.A. 46, 1196, 1938 (emphases added).
The parties disputed, however, whether the specifica-
tion’s disclosure of the “head controller 20” feature of the
corresponding structure is sufficiently definite. Deere con-
tended that it is not, because the “head controller 20” that
is “conventional in design” disclosed in the specification
“amounts to a computer or processor,” and therefore the
specification “must also disclose the algorithm by which the
computer or processor works to accomplish the claimed
function.” J.A. 1940–41 (citing HTC Corp. v. IPCom GmbH
& Co., KG, 667 F.3d 1270, 1280 (Fed. Cir. 2012)).
Deere also argued that the reference to head control-
ler 20 being “as incorporated in a Deere combine” as of 1997
(the priority date of the ’395 patent) further confirms the
specification must disclose an algorithm to satisfy the def-
initeness requirement. As context, the ’395 patent specifi-
cation does not explicitly name any commercially available
head controllers used in Deere combines. Instead, it in-
cludes the following general reference to commercial em-
bodiments: “In a specific embodiment of the present
invention, head controller 20 is as incorporated in a Deere
combine.”4 J.A. 46 at 3:49–51. Reaper submitted expert
4 As a threshold matter, our precedent allows com-
mercial embodiments to serve as corresponding structure
for means-plus-function limitations even where the speci-
fication only generically references “commercially availa-
ble” devices, so long as a skilled artisan would understand
the structure described. Budde v. Harley-Davidson, Inc.,
250 F.3d 1369, 1381–82 (Fed. Cir. 2001) (holding disclosure
of “vacuum sensors” as “commercially available units
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GRAMM v. DEERE & COMPANY 6
testimony that, as of 1997, a skilled artisan would have
known there were three commercially available head con-
trollers used in Deere combines—Dial-A-Matic Versions
#1, #2, and #3. Deere agreed that these three models were
commercially available as of 1997.
Deere argued, however, that only Dial-A-Matic Ver-
sions #2 and #3 could be corresponding structure. It iden-
tified these two models specifically because they could
control both header height and lateral position, as it ar-
gued was required by the pertinent passage from column 3
of the specification. Notably, Deere excluded from its iden-
tification of commercially available models referenced in
the specification the Dial-A-Matic Version #1. Deere ar-
gued that “the [’395 patent] specification could not possibly
have been referring to this controller” because Dial-A-
Matic Version #1 “did not control the lateral position” of
the header, which the relevant specification passage dis-
closes is a function performed by the head controller.
J.A. 1942 (emphasis in original).
Deere submitted with its claim construction briefing a
fact declaration from a retired Deere engineer, Dr. Miller,
explaining the operation of Dial-A-Matic Versions #1, #2,
and #3. Relying on Dr. Miller’s declaration, Deere argued
that Dial-A-Matic Versions #2 and #3 used microprocessors
to control header height, and therefore the ’395 patent
specification must disclose an algorithm for performing the
claimed function. Deere then argued that claim 12 is in-
definite because the specification fails to disclose such an
algorithm.
Deere also proposed an alternative construction in the
event the district court rejected its indefiniteness argu-
ment. Deere argued that, even if the Court did not find
which produce analog signals for the control unit” satisfies
the definiteness requirement).
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GRAMM v. DEERE & COMPANY 7
“control means” indefinite for lack of an algorithm, it
should “hold Plaintiffs to their argument that the ‘control-
ler’ is specifically Deere’s [Dial-A-Matic Version #1],” which
“controlled header height through a series of diodes,
switches, and integrated circuits, rather than through a
microprocessor.” J.A. 1944.
In its ruling, the district court accepted Deere’s argu-
ment that the specification does not disclose Dial-A-Matic
Version #1 as corresponding structure:
The record indicates the Dial-A-Matic Version #1
controller would not be understood as within the
scope of the conventional controllers referenced be-
cause the specification clearly indicates “head con-
troller 20 provides suitable electrical control
signals to an electrically actuated, hydraulic con-
trol system 38 for controlling the lateral position of
the corn header 12.” . . . Dial-A-Matic Version #1
lacks this capacity, whereas Version #2 does not.
J.A. 30. The district court found that the specification’s
“reference to either Dial-A-Matic Version #2 or #3 provides
sufficient support for the conclusion that the specification’s
disclosure of a head controller amounts to the disclosure of
a general-purpose computer or microprocessor.” J.A. 32. It
then found that the ’395 patent fails to disclose an algo-
rithm as part of the structure associated with “control
means” and is therefore indefinite. J.A. 37. The district
court entered judgment against Reaper, J.A. 19, and
Reaper timely appealed. We have jurisdiction under
28 U.S.C. § 1295(a)(1).
II. L EGAL STANDARD
Means-plus-function claiming allows a patentee “to ex-
press a claim limitation by reciting a function to be per-
formed rather than by reciting structure for performing
that function, while placing specific constraints on how
such a limitation is to be construed.” Williamson v. Citrix
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GRAMM v. DEERE & COMPANY 8
Online, LLC, 792 F.3d 1339, 1347 (Fed. Cir. 2015). District
courts undertake a two-step analysis when construing
means-plus-function terms. First, the court must identify
the function the means performs that is recited in the
claim. Id. at 1351. Second, the court must determine
“what structure, if any, disclosed in the specification corre-
sponds to the claimed function.” Id. To qualify as corre-
sponding structure, the intrinsic evidence must “clearly
link[] or associate[] that structure to the function recited in
the claim.” Id. at 1352. District courts must limit the rel-
evant limitation to only that structure corresponding to the
claimed function and equivalents thereof, nothing more.
See id. at 1347. If the specification fails to disclose “ade-
quate corresponding structure” to perform the claimed
function, the claim is indefinite under 35 U.S.C. § 112(b).
Id. at 1352.
The corresponding structure analysis for computer-im-
plemented means-plus-function terms compels a certain
nuance. This court’s decision in WMS Gaming, Inc. v. In-
ternational Game Technology established that “[t]he struc-
ture of a [computer or] microprocessor programmed to
carry out an algorithm is limited by the disclosed algo-
rithm.” 184 F.3d 1339, 1348 (Fed. Cir. 1999). This is be-
cause a general-purpose computer or microprocessor could
be programmed to perform a certain task in “very different
ways.” Aristocrat Techs. Austl. Pty Ltd. v. Int’l Game Tech.,
521 F.3d 1328, 1333 (Fed. Cir. 2008). Particular program-
ming converts the general-purpose computer or micropro-
cessor into a “special purpose machine for carrying out” a
particular function. Id. Thus, to satisfy the adequate cor-
responding structure requirement, computer-implemented
means-plus-function terms must have a corresponding al-
gorithm disclosed in the specification. HTC Corp., 667 F.3d
at 1280.
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GRAMM v. DEERE & COMPANY 9
III. STANDARD OF REVIEW
Claim construction determinations based on intrinsic
evidence, including whether claim language invokes or is
indefinite under 35 U.S.C. § 112(f), are reviewed de novo.
Williamson, 792 F.3d at 1346. Underlying factual determi-
nations based on extrinsic evidence are reviewed for clear
error. Teva Pharms. USA, Inc. v. Sandoz, Inc., 574 U.S.
318, 332 (2015). Under the clear error standard, “a rever-
sal is permitted only when this court is left with a definite
and firm conviction that the district court was in error.”
Alza Corp. v. Mylan Labs., Inc., 464 F.3d 1286, 1289 (Fed.
Cir. 2006).
IV. D ISCUSSION
Reaper challenges the district court’s means-plus-func-
tion analysis from several angles. First, Reaper argues the
district court erred by conducting the two-step
means-plus-function analysis out of order. Appellant
Br. 23–25. This argument is without merit. Citing Wil-
liamson, the district court’s order recites the proper two-
step analysis. J.A. 26. Nothing in the order suggests the
district court failed to identify the claimed function before
proceeding to identify corresponding structure.
Second, Reaper argues the district court erred in its de-
termination of the claimed function. Appellant Br. 25–29.
This argument is also without merit. The district court’s
order explicitly identifies “the claimed function of ‘raising
and lowering the header in accordance with said first sig-
nal in maintaining the header a designated height above
the soil.’” J.A. 29. This is the same claimed function that
Reaper identifies. Appellant Br. 26.
Reaper’s third argument catches traction. Reaper ar-
gues the district court erred by identifying corresponding
structure for “control means” beyond that which is neces-
sary to perform the claimed function. Id. at 26–30. We
agree the district court erred, and that this error in turn
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GRAMM v. DEERE & COMPANY 10
caused the district court to find claim 12 indefinite. But
the court erred, not in identifying corresponding structure
beyond that which is necessary to perform the claimed
function, but by failing to recognize that the specification’s
statement at column 3, lines 33–52, in addition to noting
that head controller 20 provides signals for controlling the
lateral position of the corn header, also does so for control-
ling “its height above the ground,” thus providing structure
for the claimed “control means.” A disclosure of an added
function in the specification should not disqualify structure
that meets the means clause’s requirements. For this rea-
son, and as discussed below, we reverse the district court’s
indefiniteness conclusion (and associated judgment
against Reaper) and remand for further proceedings.
A. Corresponding Structure
Our jurisprudence is well-settled that a
means-plus-function claim limitation covers “only the
structure . . . corresponding to the claimed function and
equivalents thereof.” Williamson, 792 F.3d at 1347.
Here, the district court erred by discounting structure
that performs the claimed function in claim 12. As we
noted above, the district court analyzed the first step
properly, identifying the claimed function as “raising and
lowering the header . . . a designated height above the soil.”
J.A. 29. But when turning to the specification for the sec-
ond step, the district court discounted corresponding struc-
ture that performs the claimed function because it did not
perform the unclaimed function of controlling “lateral posi-
tion” of the header. J.A. 29–30. Indeed, Deere’s counsel
confirmed at oral argument that the district court used the
“lateral position” capability as a “clue” for determining cor-
responding structure. Oral Arg., 16:20–34,
https://www.cafc.uscourts.gov/oral-arguments/24-1598_12
082025.mp3 (“And so [the district court judge] knew from
that passage that the controller referenced later, the one
that Reaper said was the clearly linked structure, had to
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GRAMM v. DEERE & COMPANY 11
be something other than the Dial-A-Matic #1, because all
of the evidence before her showed that the Dial-A-Matic #1
didn’t have th[e] capacity [to control lateral positioning].”).
Deere’s counsel also admitted this capability is not neces-
sary for performing the claimed function. Id. at 16:38–46
(Q: “But is that lateral positioning even necessary to the
function of the claim limitation in dispute here? A: No it’s
not, your honor . . . .”).
This court confronted a similar circumstance in Wenger
Manufacturing, Inc. v. Coating Machinery Systems, Inc.,
239 F.3d 1225 (Fed. Cir. 2001). There, we found a district
court erred by interpreting “air circulation means” to re-
quire structure capable of performing the unclaimed func-
tion of “recirculating air” in addition to the recited function
of circulating air. Wenger, 239 F.3d at 1231–33. We found
the district court “improperly restricted the ‘air circulation
means’ limitation to structure that was disclosed in the
preferred embodiment, but was not necessary to perform
the recited function of circulating air.” Id. at 1233. Here,
the district court likewise erred by restricting structure ca-
pable of performing the claimed function of controlling
header height.
Our holding in Golight, Inc. v. Wal-Mart Stores, Inc.,
355 F.3d 1327 (Fed. Cir. 2004) is also instructive. There,
we considered the means-plus-function claim limitation
“horizontal drive means” for “rotating said lamp unit in a
horizontal direction.” Golight, 355 F.3d at 1334–35. We
declined to import a requirement that corresponding struc-
ture must be capable of rotating the lamp unit at least 360
degrees, even where the single embodiment of the inven-
tion disclosed rotation of at least 360 degrees. Id. We sim-
ilarly here decline to disqualify the structure
corresponding to “control means” because it is not also ca-
pable of controlling lateral positioning of the header.
The district court’s erroneous identification of corre-
sponding structure precipitated its conclusion that
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GRAMM v. DEERE & COMPANY 12
claim 12 is indefinite. The district court excluded Deere’s
Dial-A-Matic Version #1 from its identification of corre-
sponding structure because that version lacked the capa-
bility to control lateral position of the header. And because
the district court was persuaded that both the Dial-A-Matic
Versions #2 and #3 use microprocessors to control header
height, it found that the ’395 patent specification must dis-
close an algorithm to satisfy the definiteness requirement.
Finding the specification lacked such an algorithm, the dis-
trict court held claim 12 indefinite.
The district court’s improper restriction of correspond-
ing structure provided the basis for its exclusion of Dial-A-
Matic Version #1. There is no dispute that Dial-A-Matic
Version #1 was commercially available as of 1997. And
Deere conceded in its claim construction briefing that Dial-
A-Matic Version #1 uses logic circuitry—not a microproces-
sor—to raise and lower the header.5 J.A. 1944 (“Deere’s
Dial-a-Matic [Version #1] . . . controlled header height
through a series of diodes, switches, and integrated cir-
cuits, rather than through a microprocessor.”); see also Ap-
pellee Br. 9 (citing J.A. 2474 ¶ 8), 36; Appellant Br. 31–32.
Under our precedent, the Dial-A-Matic Version #1 is there-
fore “not a general-purpose computer [and] does not trigger
the algorithm requirement.” See Qualcomm Inc. v. Intel
Corp., 6 F.4th 1256, 1267 (Fed. Cir. 2021) (“The reasoning
for the algorithm requirement of WMS Gaming does not
apply to functions implemented through circuitry.”). Thus,
we find the district court clearly erred by excluding the
Dial-A-Matic Version #1 as corresponding structure.
5 Deere’s argument on appeal that it never conceded
the Dial-A-Matic Version #1 operates in this fashion is be-
lied by the record. Appellee Br. 31–32. We find that Deere
unequivocally admitted this to be true both before the dis-
trict court and in this appeal. J.A. 1944; Appellee Br. 9, 36.
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GRAMM v. DEERE & COMPANY 13
Because Dial-A-Matic Version #1 is properly disclosed
as corresponding structure, we hold the district court erred
by determining that “control means” is indefinite.6 Car-
diac Pacemakers, Inc. v. St. Jude Med., Inc., 296 F.3d 1106,
1113–14 (Fed. Cir. 2002) (“[A] claim is valid even if only
one embodiment discloses corresponding structure.”). We
reverse the district court’s conclusion of indefiniteness and
judgment of invalidity and remand to the district court for
further proceedings consistent with this opinion.
B. Dial-A-Matic Versions #2 and #3
We now turn to the question of whether the district
court clearly erred by finding Dial-A-Matic Versions #2 and
#3 are not adequately disclosed because those versions
(1) trigger an algorithm requirement, and (2) lack a corre-
sponding algorithm in the ’395 patent specification. We
find no error as to either.
To the first issue, the district court’s determination
that the Dial-A-Matic Versions #2 and #3 require a corre-
sponding algorithm in the specification to be sufficiently
definite is not clearly erroneous. The district court consid-
ered Dr. Miller’s fact declaration7 regarding the operation
6 Further, as we noted above, Deere argued to the
district court in claim construction briefing that, if it did
not conclude “control means” was indefinite, it should find
Dial-A-Matic Version #1 is corresponding structure.
J.A. 1944.
7 Reaper also argues the district court erred by treat-
ing Dr. Miller, a fact declarant, as an expert witness. Ap-
pellant Br. 51–52. Regardless of the nomenclature the
district court assigned Dr. Miller in its ruling, the district
court permissibly relied on the declaration of Dr. Miller—a
fact witness with first-hand knowledge of the Dial-A-Matic
head controllers—as evidence of how those head controllers
operate. But going forward, the district court should be
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GRAMM v. DEERE & COMPANY 14
of those two models. J.A. 33. Dr. Miller declared that each
of Versions #2 and #3 consisted of a “microprocessor-based
controller” that was “programmed with software to control
[] header height.” Appellee Br. 9–11 (citing J.A. 2474–78,
¶¶ 9, 10, 14, 15). Dr. Miller also attached to his declaration
print-outs of Deere’s proprietary software code for Versions
#2 and #3. Id. (citing J.A. 2479–506, 2643–894). He re-
ferred to sections of those attachments that introduce the
code as controlling header height. Id. In light of this evi-
dence, we find the district court did not clearly err by de-
termining the Dial-A-Matic Versions #2 and #3 use
microprocessors to control header height and therefore re-
quire an algorithm.
To the second issue, the district court’s determination
by clear and convincing evidence that the ’395 patent lacks
a prose algorithm8 is also not clearly erroneous. Specifi-
cally, the district court did not clearly err by discrediting
Reaper’s expert’s testimony that the ’395 patent discloses
a three-step prose algorithm. The district court’s order
walks through Mr. Smith’s opinion as to how the specifica-
tion purportedly discloses each of the three steps, conclud-
ing that the cited portions of the specification “do no more
than restate the functions set forth in claim 12.”
J.A. 34–37 (citing Noah Sys., Inc. v. Intuit Inc., 675 F.3d
1302, 1317 (Fed. Cir. 2012) (“[P]urely functional language,
which simply restates the function associated with the
means-plus-function limitation, is insufficient to provide
mindful that Dr. Miller is a fact witness, not an expert wit-
ness.
8 An algorithm need not be disclosed in computer
code. “A description of the function in words may disclose,
at least to the satisfaction of one of ordinary skill in the art,
enough of an algorithm to provide the necessary structure
under § 112(f).” Typhoon Touch Techs., Inc. v. Dell, Inc.,
659 F.3d 1376, 1386 (Fed. Cir. 2011) (citation modified).
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GRAMM v. DEERE & COMPANY 15
the required corresponding structure.”)). And notably, the
district court found that Reaper’s support for the second
step of the purported prose algorithm was “not drawn from
the specification at all” and that Mr. Smith merely “cite[d]
directly to the language in claim 12 on which Plaintiffs rely
for their statement of function in their proposed construc-
tion.” J.A. 35–36. We see no clear error here.
C. Equivalents
Reaper also argues the district court erred because it
failed to consider whether “control means” should be con-
strued to include Dial-A-Matic Version #1 as an equivalent
structure to Dial-A-Matic Version #2.9 Appellant
Br. 44–46. Reaper avers that “[a]lthough the court under-
stood that it was required to construe ‘control means’ to in-
clude equivalents of the corresponding structure, it failed
to consider the issue of equivalents.” Appellant Br. 46.
Reaper’s argument reflects a fundamental misunderstand-
ing of our precedent and the means-plus-function analysis.
As we discuss above, the claim construction process for
means-plus-function limitations is two-fold. First, the
court must identify the claimed function. Second, the court
must ascertain any corresponding structure disclosed in
the specification. District courts are not required to under-
take an analysis during claim construction to determine
what equivalents may exist in the abstract. Instead, the
equivalents analysis pertains to whether an accused prod-
uct is an equivalent structure that literally infringes a
9 As discussed above, we find that Dial-A-Matic Ver-
sion #1 is properly within the scope of corresponding struc-
ture, and thus we need not address this exact issue.
Because we remand for further proceedings, we address
whether the district court must assess whether Dial-A-
Matic Versions #2 and #3 are equivalent to Dial-A-Matic
Version #1.
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GRAMM v. DEERE & COMPANY 16
means-plus-function limitation. Intellectual Sci. & Tech.,
Inc. v. Sony Elecs., Inc., 589 F.3d 1179, 1183 (Fed. Cir.
2009) (“For a means-plus-function claim term, the term lit-
erally covers an accused device if the relevant structure in
the accused device performs the identical function recited
in the claim and that structure is identical or equivalent to
the corresponding structure disclosed in the specifica-
tion.”). Thus, for purposes of claim construction, the dis-
trict court need only ascertain the corresponding structure
disclosed in the specification, not what equivalents may ex-
ist.
V. CONCLUSION
We have considered the parties’ remaining arguments
and find them unpersuasive. For the foregoing reasons, we
reverse the district court’s determination that “control
means” is indefinite. We remand to the district court for
further proceedings in accordance with this opinion.
REVERSED AND REMANDED
COSTS
Costs against Deere.
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