Primos, Inc. v. Hunter's Specialties, Inc.

Error: Bad annotation destination
United States Court of Appeals for the Federal Circuit
05-1001,-1376

PRIMOS, INC.,

Plaintiff-Appellee,

v.

HUNTER’S SPECIALTIES, INC. and DAVID FORBES,

Defendants-Appellants,

and

WAYNE CARLTON and CARMEN FORBES,

Defendants.

Brett L. Foster, Holland & Hart LLP, of Salt Lake City, Utah, argued for plaintiff-
appellee. With him on the brief were L. Grant Foster and Mark A. Miller.

Edmund J. Sease, McKee, Voorhees & Sease, P.L.C., of Des Moines, Iowa,
argued for defendants-appellants. With him on the brief was Jeffrey D. Harty.

Appealed from: United States District Court for the Northern District of Iowa

Chief Magistrate Judge John A. Jarvey
United States Court of Appeals for the Federal Circuit

05-1001, -1376

PRIMOS, INC.,

Plaintiff-Appellee,

v.

HUNTER’S SPECIALTIES, INC. and DAVID FORBES,

Defendants-Appellants,

and

WAYNE CARLTON and CARMEN FORBES,

Defendants.

_____________________

DECIDED: June 14, 2006
_____________________

Before NEWMAN, LOURIE, and PROST, Circuit Judges.

LOURIE, Circuit Judge.

Hunter’s Specialties, Inc. and David Forbes (collectively “Hunter’s Specialties”)

appeal from the judgment of the United States District Court for the Northern District of

Iowa of literal infringement, willfulness, and inducement of infringement as to U.S.

Patent 5,520,567 and infringement under the doctrine of equivalents as to U.S. Patent

5,415,578. Hunter’s Specialties also appeals from the court’s decision denying a

motion for a new trial. Primos, Inc. v. Hunter’s Specialties, Inc., No. C01-004 (N.D. Iowa

Sept. 9, 2004) (“Final Judgment”). Because we affirm the district court’s claim

construction of the term “engaging,” we also affirm the court’s judgment of literal
infringement of the ’567 patent. Because we conclude that the application of the

doctrine of equivalents was proper, we affirm the court’s judgment of infringement of the

’578 patent under the doctrine of equivalents. Because the court did not abuse its

discretion in excluding evidence, and the court’s adverse-inference jury instruction did

not constitute prejudicial error, we affirm the court’s decision denying a new trial on

those issues.

BACKGROUND

This appeal involves the ’578 patent and its continuation, the ’567 patent, which

are assigned to Primos, Inc. (“Primos”) and entitled “Game Call Apparatus.” The

patents disclose a diaphragm mouth call that hunters use to simulate animal sounds.

Figure 1, shown below, is an embodiment of the invention:

As depicted in that figure, the diaphragm mouth call 10 consists of a frame 18, a

membrane 22 that vibrates to produce sound, a flexible peripheral edge 12, and a shelf

or plate 15 extending above the membrane. The diaphragm mouth call is placed

completely within the user’s mouth, with the free-end of the membrane positioned near

the opening of the mouth. ’578 patent, col. 2, ll. 62-64. The user holds the diaphragm

in place with his or her tongue, while forcing air to travel through a gap between the

05-1001, -1376 2
tongue and the membrane. The air causes the membrane to vibrate and to emit a

sound that replicates a particular animal. Id. at col. 1, ll. 31-38. The sound produced by

the call is affected by the tongue pressure applied to the membrane and the distance

between the membrane and the roof of the mouth. Id. at col. 1, ll. 38-40. The patented

diaphragm mouth call claims an improvement over prior mouth call devices in that the

shelf or plate provides a constant distance above the membrane and resists upward

pressure by the tongue. Id. at col. 2, ll. 15-26.

Relevant to this appeal are claim 2 of the ’578 patent and claim 21 of the ’567

patent. Claim 2 of the ’578 patent reads as follows:

A game call apparatus to be completely inserted inside a person’s mouth
for calling game, comprising:
a frame;
a membrane of material stretched over the frame;
a flexible and moldable peripheral edge extending outwardly from
the frame; and
a plate having a length, the plate extending generally upward from
the frame and over a portion of the membrane, the plate being
differentially spaced above the portion of the membrane at various
locations along the length of the plate.

’578 patent, col. 4, ll. 45-55 (emphases added). Claim 21 of the ’567 patent

reads as follows:

A game call for use inside a person’s mouth, comprising:
a U-shaped frame;
a yieldable reed spanning across the U-shaped frame;
a first roof-of-mouth engaging yieldable sealing portion carried by
the frame;
a second roof-of-mouth engaging portion extending upwardly from
the frame, the second portion being spaced away from the first
portion, the first and second portions defining a predetermined
orientation of the U-shaped frame insider the mouth relative to the
roof of mouth.

’567 patent, col. 6, ll. 20-32 (emphases added).

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 On January 24, 2001, Primos filed suit against its competitor, Hunter’s

Specialties, alleging that Hunter’s Specialties’s accused device, known as the Tone

Trough, infringed Primos’s patents. The accused Tone Trough is a diaphragm mouth

call device that, among other features, contains a dome extending above the

membrane, instead of a shelf or plate, as claimed in Primos’s patents. Primos

subsequently amended its complaint, alleging that individual defendant David Forbes

induced infringement of its patents.1

Primos initially moved for summary judgment of literal infringement and for a

preliminary injunction against Hunter’s Specialties. Hunter’s Specialties filed several

cross-motions, including for summary judgment of noninfringement, both literally and

under the doctrine of equivalents. On July 24, 2002, the court denied all the motions

filed by both parties. In its decision, the court construed the term “plate” in claim 2 of

the ’578 patent to mean “a structural element of relatively uniform thickness and flatness

which may also have some moderate curvature to it.” Primos v. Hunter’s Specialties,

No. C01-004 MJM (N.D. Iowa July 24, 2002) (“Summary Judgment Order”). Relying on

that construction of the term “plate,” the court found that “reasonable minds could differ

as to the presence or absence of a ‘plate’ in the Tone Trough” and thus denied all

summary judgment motions relating to infringement of the ’578 patent. Id. Regarding

claim 21 of the ’567 patent, the court noted that while the term “second-roof-of-mouth

engaging portion” is not in dispute, it stated that “it is clear that this language requires

1
The amended complaint also included allegations against individuals
Carman Forbes and Wayne Carlton for inducing infringement. The court dismissed
Carman Forbes from the case prior to trial, and it ultimately vacated judgment against
Wayne Carlton. Thus, only David Forbes and Hunter’s Specialties remain as parties to
this appeal.

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that a portion of the claimed device . . . come into contact with the roof of the user’s

mouth while in use.” Id., slip op. at 43. The court then determined that there were

genuine issues of material fact relating to whether the Tone Trough device operates

when touching the roof of a user’s mouth, and therefore denied the summary judgment

motions relating to infringement of the ’567 patent.

Hunter’s Specialties then requested a Markman hearing to interpret the term

“engaging” in claim 21 of the ’567 patent. On March 15, 2004, the court construed that

term to mean to “come into contact with.” Primos v. Hunter’s Specialties, No. C01-004

(N.D. Iowa Mar. 15, 2004) (“Claim Construction Order”). The court rejected Hunter’s

Specialties’ construction of the term “engaging” as “interlocking,” noting that while the

word “interlocking,” as defined in a standard dictionary, may be appropriate in the

context of a transmission or a latch, it is not appropriate in the context of the roof of

one’s mouth. The court also observed that the specification of the ’567 patent did not

support a construction of “engaging” to mean “interlocking” because the figures in the

patent did not provide any means with which the diaphragm mouth call could interlock in

the roof of a mouth. According to the court, it had previously interpreted “engaging” to

mean “to come into contact with,” and it saw no reason to modify that construction.

Hunter’s Specialties again moved for summary judgment, asserting that

prosecution history estoppel barred the application of the doctrine of equivalents as to

the ’578 patent in light of our intervening decision in Festo Corp. v. Shoketsu Kinzoku

Kogyo Kabushiki Co., Ltd., 344 F.3d 1359 (Fed. Cir. 2003). The court determined that

the term “plate” was amended during prosecution by describing it as “having a length,”

but that that amendment did not narrow the scope of the claim because “all physical

05-1001, -1376 5
objects have a length.” Primos v. Hunter’s Specialties, No. C01-004 MJM (N.D. Iowa

Mar. 12, 2004) (“Prosecution History Estoppel Order”). The court also observed that the

term “plate” was amended to require that it be “differentially spaced” above the

membrane, which narrowed the scope of the claim. Id. According to the court, the

subject matter surrendered by that amendment involved “objects that are not

differentially spaced above the membrane.” Because the Tone Trough contained a

dome that was spaced above the membrane and therefore arguably did not fall within

that surrendered area, the court denied summary judgment of no infringement under the

doctrine of equivalents as to the ’578 patent.

Finally, before trial, Primos filed a motion requesting that a device known as the

Aluminum Flap Call not be introduced as evidence during trial. The court granted that

motion, and noted in its order that, throughout discovery, Hunter’s Specialties never

identified the Aluminum Flap Call as invalidating prior art. Primos v. Hunter’s

Specialties, No. C01-004 MJM (N.D. Iowa Mar. 12, 2004) (“Aluminum Flap Call Order”).

Hunter’s Specialties had sought to introduce the Aluminum Flap Call device when it

claimed it had found the device, which was approximately three months prior to trial and

several months after discovery had closed. However, Hunter’s Specialties failed to offer

any explanation why it could not locate the Aluminum Flap Call during discovery. In

light of those circumstances, the court determined that allowing the Aluminum Flap Call

to be introduced as evidence during trial would result in unfair surprise to Primos, and

thus the court granted Primos’s motion to exclude the Aluminum Flap Call as evidence.

A jury trial commenced on March 15, 2004. In the jury instructions concerning

inducement of infringement against individual defendants Wayne Carlton and David

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Forbes, the court instructed the jury that it could consider several factors and stated that

“the assertion of the attorney-client privilege with respect to a non-infringement opinion

may support an inference that the withheld advice of counsel was adverse to that party.”

As for willful infringement against Hunter’s Specialties, the court did not instruct the jury

as to an adverse inference but rather stated that the jury must consider the “totality of

the circumstances.” After a three-and-a-half week trial, the jury found that Hunter’s

Specialties’ Tone Trough device literally infringed the ’567 patent, and infringed the ’578

patent under the doctrine of equivalents. The jury also found that Hunter’s Specialties

willfully infringed the ’567 patent and that David Forbes and Wayne Carlton induced

infringement of that patent.

Hunter’s Specialties and Wayne Carlton moved for judgment as a matter of law

(“JMOL”), arguing that the court improperly construed the term “engaging” in claim 21 of

the ’567 patent and that the “all limitations rule” and prosecution history estoppel barred

the application of the doctrine of equivalents as to the ’578 patent. Those defendants

also moved for a new trial, arguing that the court erred in excluding the Aluminum Flap

Call as evidence, and that the court’s adverse-inference instruction resulted in

prejudicial error. The court denied the motion for JMOL and the motion for a new trial.

Primos v. Hunter’s Specialties, No. C01-004 (N.D. Iowa Mar. 31, 2005). (“Post-Trial

Order”). In its decision, the court first reaffirmed its construction of the claim term

“engaging” in claim 21 of the ’567 patent, noting that it had addressed the same issue in

previous decisions. The court next determined that the “all limitations rule” did not

preclude the application of the doctrine of equivalents for the ’578 patent, reasoning that

the only disputed term was “plate” in claim 2, and that determining that a dome was

05-1001, -1376 7
equivalent to a plate did not vitiate that claim limitation. The court also held that

prosecution history estoppel did not prevent the application of the doctrine of

equivalents as to the ’578 patent because the Tone Trough did not fall within the area

surrendered during prosecution. In addition, the court denied Hunter’s Specialties’s

motion for a new trial, reaffirming its prior decision that the Aluminum Flap Call device

could not be introduced as invalidating prior art because it was produced after the

period for discovery had closed. Although the court determined that its “adverse

inference” instruction to the jury was not in error, the court later vacated judgment

against Wayne Carlton, the only defendant who had asserted the attorney-client

privilege, in light of our decision in Knorr-Bremse Systeme Fuer Nutzfahrzeuge GMBH

v. Dana Corp., 383 F.3d 1337 (Fed. Cir. 2004) (en banc).

Hunter’s Specialties timely appealed to this court, and we have jurisdiction

pursuant to 28 U.S.C. § 1295(a)(1).

DISCUSSION

We review a district court’s denial of a motion for JMOL de novo by reapplying

the JMOL standard. Markman v. Westview Instruments, Inc., 52 F.3d 967, 975 (Fed.

Cir. 1995) (en banc). We also review the legal standards that the jury applied in

reaching its verdict to determine whether they were correct as a matter of law. Id. at

975. JMOL is appropriate when “there is no legally sufficient evidentiary basis for a

reasonable jury to find for that party on that issue.” Fed. R. Civ. P. 50(a)(1). The denial

of a motion for a new trial is an issue not unique to patent law; thus, we apply the law of

the regional circuit in which the district court sits—in this case, the Eighth Circuit. In the

05-1001, -1376 8
Eighth Circuit, the decision to deny a motion for a new trial is reviewed under an abuse

of discretion standard. Blair v. Wills, 420 F.3d 823, 829 (8th Cir. 2005).

I. Claim Construction

The question of literal infringement of claim 21 of the ’567 patent turns entirely on

the district court’s construction of the term “engaging.” Claim construction is a question

of law reviewed de novo. Cybor Corp. v. FAS Techs., Inc. 138 F.3d 1448, 1454-56 (Fed.

Cir. 1998) (en banc). Hunter’s Specialties argues that the court erred in construing the

term “engaging” in the phrase “second roof-of-mouth engaging yieldable sealing portion”

to mean “to come into contact with.” According to Hunter’s Specialties, the proper

construction of the term “engaging” is “sealing” or “interlocking.” As support for its

construction, Hunter’s Specialties notes that claim 21 uses the word “engaging” to

describe a seal created between the edge of the frame and the roof of the user’s mouth.

Also, Hunter’s Specialties observes that the specification describes the edge as

“sealing” against the roof of a mouth. In addition, Hunter’s Specialties finds support for

its construction in a dictionary definition that describes “engaging” as “to come together

and interlock.” Hunter’s Specialties points out that this definition is consistent with the

way the term is used throughout the patent.

Primos responds that the district court correctly construed “engaging” as “to

come into contact with.” According to Primos, the intrinsic evidence does not support

the selective dictionary definition put forth by Hunter’s Specialties. In particular, the

claims use both terms, “engaging” and “sealing,” and thus each term is presumed to

have a distinct meaning. Also, Primos asserts that to construe “engaging” as “sealing”

or “interlocking” would exclude a preferred embodiment of the patent because the

05-1001, -1376 9
figures in the patent show the membrane as not interlocking with the roof of a mouth. In

addition, Primos observes that while “interlocking” might be an appropriate construction

of “engaging” for an invention relating to mechanical machinery with gears, it is not

appropriate in the context of diaphragm mouth calls.

We agree with Primos that the district court correctly construed the term

“engaging” to mean “to come into contact with.” As this court explained in Phillips v.

AWH Corp., we ordinarily construe claim terms to have their customary meaning as

understood by a person of ordinary skill in the art. 415 F.3d 1303, 1312-17 (Fed. Cir.

2005) (en banc). In ascertaining the ordinary and customary meaning of a claim term, a

court’s primary focus should be on the intrinsic evidence of record, viz., the claims, the

specification, and, if in evidence, the prosecution history. Id. Starting with the language

of claim 21, the terms “engaging” and “sealing” are both expressly recited in the claim

and therefore “engaging” cannot mean the same thing as “sealing”; if it did, one of the

terms would be superfluous.

Turning to the specification, although the word “engaging” is not expressly

mentioned in the specification, figures 1 and 3 aid our understanding of that term.

Figure 3, as depicted below, shows a call device positioned in a user’s mouth.

05-1001, -1376 10
As shown in the figure above, there are several points of contact between the roof of a

user’s mouth (the top striped structure in the figure above) and the diaphragm mouth

call—one such point is with the plate 24 and another is with the peripheral edge of the

frame 12. That figure shows the plate touching the roof of the mouth, but does not

reveal an interlocking relationship because there is no depicted means from which the

frame can “interlock” with the roof of a user’s mouth. The figure therefore supports a

construction of “engaging” as to “come into contact with,” while discouraging a

construction of “interlocking.” While we are mindful that we cannot import limitations

from the preferred embodiments into the claim, we also should not normally interpret a

claim term to exclude a preferred embodiment. See Burke, Inc. v. Bruno Indep. Living

Aids, Inc., 183 F.3d 1334, 1341 (Fed. Cir. 1999). Interpreting “engaging” to mean

“interlocking” would exclude the embodiment shown in the figure and is not consistent

with the rest of the specification which does not suggest an interlocking relationship

between the roof of a mouth and the mouth call.2 We therefore agree that the district

court’s construction of the term “engaging” to mean “to come into contact with” is

supported by the intrinsic record and is correct.

II. Doctrine of Equivalents

Hunter’s Specialties challenges the application of the doctrine of equivalents on

the ground that prosecution history estoppel applies to the term “plate.” Hunter’s

Specialties specifically asserts that amendments to the term “plate” narrowed the scope

of the claim and were made for reasons relating to patentability. According to Hunter’s

Specialties, prosecution history estoppel therefore barred the doctrine of equivalents for

2
We do not discuss the prosecution history here because it is not relevant
to the construction of the term “engaging.”

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that claim term. Primos responds that the district court properly applied the doctrine of

equivalents. It reasons that the first amendment made to the term “plate”—that it

include a “length”—did not narrow the scope of the claim. As to the second amendment

made to the term “plate”—that it be “differentially spaced” above the membrane—that

amendment bears no more than a tangential relationship to the accused Tone Trough.

In particular, Primos contends that the territory surrendered by that amendment consists

of objects that are not differentially spaced above the membrane. Because the accused

device’s “dome” is differentially spaced above the membrane, Primos asserts that the

“differentially spaced” amendment does not pertain to the disputed element in the

accused device and it is therefore merely tangential to the accused device. According

to Primos, prosecution history estoppel thus does not apply to prevent the application of

the doctrine of equivalents here.

We agree with Primos that the district court correctly determined that prosecution

history estoppel does not apply here to preclude the application of the doctrine of

equivalents. As the Supreme Court explained in Festo, when a patent claim is

amended during prosecution for reasons relating to patentability, there is a presumption

that the patentee surrendered all the territory between the original claim limitation and

the amended claim limitation. 535 U.S. at 740. There are situations, however, in which

a patentee may overcome that presumption. Id. One such situation is when the

“rationale underlying the amendment may bear no more than a tangential relation to the

equivalent in question.” Id. at 740-41.

The term “plate” in claim 2 of the ’578 patent was amended in two ways: (1) by

requiring that it have a “length” and (2) by adding the limitation that the plate be

05-1001, -1376 12
“differentially spaced” above the membrane. The district court correctly recognized that

the addition of the term “length” did not narrow the scope of the claim because every

physical object has a length. The district court also determined that adding the

limitation that the plate be “differentially spaced” above the membrane did narrow the

scope of the claim, and the court assumed that the reason for the amendment was a

substantial one relating to patentability. We agree with the district court, however, that

the territory surrendered by the “differentially spaced” amendment comprises plates that

are not differentially spaced above the membrane. That conclusion is consistent with

the prosecution history. The patentee added the “differentially spaced” limitation to

distinguish the diaphragm mouth call from a prior art device that consisted of a shelf-like

structure positioned on top of the membrane without any spacing. The accused device,

however, includes a dome that is spaced above the membrane. Because the accused

device’s dome includes the spacing, the amendment was merely tangential to the

contested element in the accused device, and thus prosecution history estoppel does

not apply to prevent the application of the doctrine of equivalents.

Hunter’s Specialties also argues that the court should not have allowed the

application of the doctrine of equivalents because, by doing so, the claim limitation

“plate” in claim 2 of the ’578 patent was vitiated. According to Hunter’s Specialties, the

court’s construction of the term “plate” requires a specific structure “of relatively uniform

thickness and flatness which may also have some moderate curvature to it. Hunter’s

Specialties asserts that allowing a “dome” to be considered an equivalent to a “plate”

would eliminate that limitation from the claim. Primos responds that the “all limitations

rule” is not applicable to the circumstances in this case. According to Primos, the term

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“plate” does not convey a definitive, geometric shape or structure, and thus that claim

limitation was not vitiated. Primos asserts that the district court properly allowed the jury

to consider whether a “dome” was equivalent to a “plate” and that in doing so, no claim

limitation was eliminated.

We agree with Primos that the application of the doctrine of equivalents was not

improper in this case. Under the doctrine of equivalents, “a product or process that

does not literally infringe upon [sic] the express terms of a patent claim may

nonetheless be found to infringe if there is ‘equivalence’ between the elements of the

accused product or process and the claimed elements [sic] of the patented invention.”

Warner-Jenkinson Co., Inc. v. Hilton Davis Chem. Co., 520 U.S. 17, 21 (1997) (citation

omitted). The “all limitations rule” restricts the doctrine of equivalents by preventing its

application when doing so would vitiate a claim limitation. Warner-Jenkinson, 520 U.S.

at 29 (stating that the doctrine of equivalents cannot be applied broadly so as to

“effectively eliminate that [claim] element in its entirety”); Lockheed Martin Corp., 324

F.3d at 1321 (“[I]f a court determines that a finding of infringement under the doctrine of

equivalents ‘would entirely vitiate a particular claim element,’ then the court should rule

that there is no infringement under the doctrine of equivalents.” (citation omitted)).

On appeal, Hunter's Specialties argues that we should reverse the jury’s finding

of equivalence because the substitution of the accused dome for the claimed “plate”

would vitiate the “plate” limitation and thereby violate the all limitations rule. As the

district court recognized, Hunter’s Specialties is essentially contending that there can be

no equivalent to the claimed “plate.” Our precedent has recognized that “[t]here is no

set formula for determining whether a finding of equivalence would vitiate a claim

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limitation, and thereby violate the all limitations rule. Rather, courts must consider the

totality of the circumstances of each case and determine whether the alleged equivalent

can be fairly characterized as an insubstantial change from the claimed subject matter

without rendering the pertinent limitation meaningless.” Freedman Seating Co. v. Am.

Seating Co., 420 F.3d 1350, 1359 (Fed. Cir. 2005) (citations omitted). Thus, because

Primos’s theory of equivalence (i.e., that a dome is equivalent to the claimed “plate”)

does not “effectively eliminate . . . [the ‘plate’ limitation] in its entirety,” it does not violate

the all limitations rule. Noting that Hunter’s Specialties has not challenged whether the

jury’s finding is supported by substantial evidence, we affirm the jury’s finding that the

accused dome is equivalent to the claimed “plate.”

III. Exclusion of Evidence

Hunter’s Specialties next argues that the district court abused its discretion in

excluding a prior art device, the Aluminum Flap Call, from evidence because admitting it

would have resulted in prejudicial surprise. According to Hunter’s Specialties, even

though the device itself was not located until shortly before trial began, Primos was

aware of it as being potential prior art throughout discovery. For example, Hunter’s

Specialties asserts that defendant Wayne Carlton was extensively questioned by

Primos on the Aluminum Flap Call device. Hunter’s Specialties also asserts that Primos

waited until shortly before the commencement of trial to claim prejudicial surprise, even

though it knew about the device much earlier. In addition, Hunter’s Specialties argues

that there is a strong public policy in favor of allowing the Aluminum Flap Call as

evidence because the public interest requires consideration of any invalidating prior art

device.

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 Primos responds that the district court properly excluded the Aluminum Flap Call

because Hunter’s Specialties never identified that device as potentially invalidating prior

art during discovery. In addition, Primos asserts that the defendants did not provide an

explanation as to why they could not locate that device during discovery. According to

Primos, to permit the Aluminum Flap Call to be introduced as evidence during trial, after

years of discovery during which that device was not identified, would result in prejudicial

surprise. Also, although the Aluminum Flap Call may have been mentioned during

discovery, its origin could not be authenticated, and the testimony revealed that the

prototypes were experimental in nature. Thus, there was no reason for Primos to

believe that the Aluminum Flap Call was prior art and would be introduced as evidence.

We agree with Primos that the district court did not abuse its discretion in

excluding the Aluminum Flap Call from evidence. The record reflects that the Aluminum

Flap Call was not located until after discovery had closed. Moreover, although the

Aluminum Flap Call may have been mentioned during discovery, it was never identified

to the court as an invalidating prior art device. The district court prevented Hunter’s

Specialties from introducing the Aluminum Flap Call into evidence because it “did not

demonstrate diligence in attempting to locate the call during discovery” and because

during discovery Hunter’s Specialties did not assert that it was claiming the Aluminum

Flap Call as invalidating prior art. That determination was not an abuse of discretion. It

was well within the district court’s province to determine that because the Aluminum

Flap Call was not identified as potential prior art until after discovery had closed and

shortly before trial commenced, it would then be unfair to permit its introduction into

evidence.

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 We reject Hunter’s Specialties’ argument that policy concerns should override the

district court’s decision to exclude the Aluminum Flap Call as evidence. First, and most

importantly, the court never determined whether the Aluminum Flap Call was in fact

invalidating prior art, and the parties dispute whether the device was in public use—it

was asserted that its use was experimental and occurred only in Canada. Thus, the

Aluminum Flap Call may in fact not have been invalidating prior art at all. Second, as

the district court pointed out, the purpose of discovery is to enable parties to obtain the

factual information needed to prepare their cases for trial. The district court must

therefore consider the “unfair and prejudicial surprise” to a party that may result from

allowing evidence to be presented during trial. See ATD Corp. v. Lydall, Inc., 159 F.3d

534, 551 (Fed. Cir. 1998) (stating that the purpose of both the Federal Rules of Civil

Procedure and 35 U.S.C. § 282 is to prevent unfair and prejudicial surprise and not to

permit last-minute production of evidence). The district court determined that Hunter’s

Specialties had ample opportunity to introduce the Aluminum Flap Call during the two

and a half year discovery phase. Because it did not do so, the district court was entitled

to decide that Hunter’s Specialties may not then introduce disputed evidence beyond

the time allotted for discovery.

IV. Adverse-Inference Jury Instruction

Finally, Hunter’s Specialties asserts that under Knorr-Bremse, 383 F.3d at 1337,

the district court erred in instructing the jury that it could draw an adverse-inference from

an opinion withheld due to the assertion of the attorney-client privilege. Although

Hunter’s Specialties recognizes that the only defendant to assert the attorney-client

privilege was Wayne Carlton, it argues that the adverse-inference jury instruction

05-1001, -1376 17
prejudiced all defendants because the infringement claim involved all defendants and

was tried to one jury. Primos responds that the court vacated the judgment against

Wayne Carlton, the only individual who asserted the attorney-client privilege and

therefore the only person who was potentially prejudiced by the jury instruction. Primos

points out that Hunter’s Specialties waived the attorney-client privilege and thus was not

affected by the adverse jury instruction. In addition, Primos contends that Hunter’s

Specialties did not present any evidence on how it was prejudiced by the jury’s

instruction.

We agree with Primos that the jury instruction did not prejudice Hunter’s

Specialties. A party seeking to alter a judgment based on erroneous jury instructions

must establish that “those instructions were legally erroneous,” and that “the errors had

prejudicial effect.” Advanced Display Sys., Inc. v. Kent State Univ., 212 F.3d 1272,

1281 (Fed. Cir. 2000). Legal error in an erroneous jury instruction is prejudicial when it

is “inconsistent with substantial justice.” Fed. R. Civ. P. 61. The jury’s instruction for

inducement of infringement against individual defendants David Forbes and Wayne

Carlton provided that “the assertion of the attorney-client privilege with respect to a non-

infringement opinion may support an inference that the withheld advice of counsel was

adverse to that party.” That jury instruction thus permitted an adverse inference to be

drawn against the party that asserted the attorney-client privilege. The only individual

who asserted the attorney-client privilege, however, was Wayne Carlton, and the court

vacated the judgment of inducement of infringement against him. The only individual

therefore potentially prejudiced by the adverse-inference instruction was Wayne

Carlton, not Hunter’s Specialties. In addition, in the jury’s instruction as to willful

05-1001, -1376 18
infringement against individual defendant Hunter’s Specialties, the express adverse

inference language was absent. Rather, the instruction stated that the jury must

consider the totality of the circumstances and may rely on a number of factors to

support a finding of willfulness. There was therefore no adverse-inference instruction as

to willfulness against Hunter’s Specialties. Thus, we conclude that the jury’s instruction

was not legally erroneous and did not result in prejudicial error against either individual

defendants Hunter’s Specialties or David Forbes.

We have considered Hunter’s Specialties other arguments and find them to be

unpersuasive.

CONCLUSION

Because the court properly construed the term “engaging,” we affirm the court’s

judgment of literal infringement. Because the claim term “plate” is a structure that was

not vitiated by substitution of a dome, we affirm the court’s conclusion that applying the

doctrine of equivalents was not improper. Also, because the amendment was merely

tangential to the contested element in the accused device, we affirm the court’s

determination that prosecution history estoppel did not preclude the application of the

doctrine of equivalents. Finally, because the court did not abuse its discretion in

excluding the Aluminum Flap Call as evidence and because its adverse-inference

instruction did not constitute prejudicial error, we affirm the court’s decision denying a

new trial.

AFFIRMED.

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