2007-1302 | Omnilex

Gesamter Gesetzestext

United States Court of Appeals for the Federal Circuit
2007-1302, -1303, -1304
O2 MICRO INTERNATIONAL LIMITED,
Plaintiff-Appellee,
v.
BEYOND INNOVATION TECHNOLOGY CO., LTD.,
Defendant-Appellant,
and
FSP GROUP and SPI ELECTRONIC CO., LTD.,
Defendants-Appellants,
and
LIEN CHANG ELECTRONIC ENTERPRISE CO., LTD.,
Defendant-Appellant.
James Pooley, Morrison & Foerster LLP, of Palo Alto, California, argued for
plaintiff-appellee. With him on the brief was Bryan Wilson. Of counsel on the brief was
Richard S.J. Hung, of San Francisco, California. Of counsel were Duane H. Mathiowetz,
Howrey LLP, of San Francisco, California; and Richard C. Lin and Henry C. Su, of East
Palo Alto, California.
Stanley Young, Heller Ehrman LLP, of Menlo Park, California, argued for
defendant-appellant Beyond Innovation Technology Co., Ltd. With him on the brief was
Sarah R. Houghland. Of counsel on the brief were Johnny Cheng-Teh Chiu, of
Washington, DC; E. Joshua Rosenkranz, of New York, New York; and Ethan C. Glass,
of San Francisco, California.
Gregory W. Carr, Carr LLP, of Dallas, Texas, for defendants-appellants FSP
Group and SPI Electronic Co., Ltd. With him on the brief was Theodore F. Shiells.
Mao-Sen Yieh, Law Offices of Mao-Sen Yieh, of Houston, Texas, for defendant-
appellant Lien Chang Electronic Enterprise Co., Ltd.
Appealed from: United States District Court for the Eastern District of Texas
Judge T. John Ward

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judgment by the United States District Court for the Eastern District of Texas. O2 Micro
Int’l Ltd. v. Beyond Innovation Tech. Co., No. 2:04-CV-32 (E.D. Tex. Mar. 21, 2007). A
jury found that Defendants-Appellants willfully induced the infringement of claims 1, 15,
35, and 39 of U.S. Patent No. 6,259,615 (“the ’615 patent”), claims 12 and 16 of U.S.
Patent No. 6,396,722 (“the ’722 patent”), and claims 13, 16, and 17 of U.S. Patent No.
6,804,129 (“the ’129 patent”), all of which are owned by Plaintiff-Appellee O2 Micro
International Ltd. (“O2 Micro”). The district court entered a final judgment and
permanent injunction. For the reasons explained below, we vacate and remand for
further proceedings.
I. BACKGROUND
A. Patents-in-Suit
The patents-in-suit1 are directed to DC-to-AC converter circuits, which convert
low voltage direct current (“DC”) into higher voltage alternating current (“AC”). Also
called inverter controllers, these circuits may be used to control the amount of power
delivered to cold cathode fluorescent lamps (“CCFLs”) that are used to backlight the
screens of laptop computers and televisions. When powered by a battery or other DC
power source, a CCFL uses a DC-to-AC converter circuit because CCFLs are designed
to run on AC power. The patents-in-suit describe a converter circuit that employs a
feedback control loop to control the amount of power delivered from the DC power
source (the “drive”) to the CCFL (the “load”).
1 The patents-in-suit are related—the ’129 patent is a continuation of a
continuation of the ’722 patent, which is a continuation of the ’615 patent—and share a
common specification. For simplicity, we refer to the disclosure of the ’615 patent and
omit the parallel citations to the ’722 patent and the ’129 patent.
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As shown in Figure 2 of the ’615 patent, the converter circuit includes a number
of switches (80) placed between the drive (12) and the load (20). Drive circuitry (50)
associated with each switch determines when and how long a given switch will be
turned on (“ON time”). If a pair of switches along a conduction path are ON
simultaneously, the circuit will deliver more power to the load. Thus, by adjusting the
overlap between switches’ ON times, the circuit can precisely control the amount of
power delivered to the load.
’615 patent’s Figure 2
The converter circuit uses a feedback control loop (40) to affect the switches’ ON times.
To the feedback control loop, the converter circuit provides a feedback signal (FB)
indicative of the total current (and, thus, power) at the load and a reference voltage
(REF) indicative of the desired load conditions (for example, the desired total current at
the load). An error amplifier (32) compares the feedback signal (FB) and the reference
voltage (REF) to produce a comparison signal (CMP). During normal operation, the
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drive circuitry (50) receives the comparison signal (94) and may use it to adjust the
switches’ ON times, thereby regulating the power to the load.
To protect the circuitry from damage during an open-circuit condition (such as
when a CCFL breaks or becomes disconnected), the feedback signal (FB) may also be
compared to a reference value (not shown in Figure 2) at the current sense comparator
(42). This reference value preferably reflects the minimum or maximum current
permitted by the system. Thus, when the value of the feedback signal (FB) is within a
permitted range (i.e., during normal operation), the current sense comparator (42)
allows the comparison signal (CMP) to flow through switch 38; however, when the value
of the feedback signal is outside that range (e.g., during an open circuit or short circuit
condition), the current sense comparator substitutes a minimum voltage (Vmin) for the
comparison signal (CMP) at switch 38. In the latter case, the minimum voltage
minimizes the overlap of the switches’ ON times, reducing the power to a safer level
while avoiding shutdown if the lamp remains operable.
During prosecution of the application, the examiner rejected the ’615 patent
under 35 U.S.C. § 103 as unpatentable over a combination of U.S. Patent No.
5,384,516 to Kawabata (“Kawabata”) and U.S. Patent No. 6,011,360 to Gradzki
(“Gradzki”). The examiner observed that the feedback loop described in the originally
filed claims was obvious, stating that “Gradzki et al. teaches the utilization of the
technique for a feedback loop circuit between the load and the drive circuitry supplying
a feedback signal indicative of power being supplied to the load.” J.A. 7638. The
examiner found that, like the application’s pending claims, Gradzki discloses an inverter
controller that regulates lamp power irrespective of the level of the feedback signal.
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In response to the examiner’s rejection, O2 Micro added a limitation to each of
the independent claims. Specifically, O2 Micro amended Claim 1 of the ’615 patent to
require that the feedback control loop circuit control the conduction state of the switches
“only if said feedback signal is above a predetermined threshold” (the “‘only if’
limitation”). O2 Micro provided little explanation for the amendment, stating that “[i]n
contrast to [the prior art], Applicant’s invention of independent claim 1 requires, inter
alia, a DC/AC converter circuit that includes a feedback control loop circuit . . . adapted
to generate a second pulse signal . . . only if said feedback signal is above a
predetermined threshold.” J.A. 7626. After receiving this amendment, the examiner
issued a notice of allowance.
Claim 1 of the ’615 patent is representative of the asserted claims for the issues
presented by this appeal. As issued, it requires, in relevant part, a DC/AC converter
circuit comprising:
a feedback control loop circuit receiving a feedback signal indicative of
power being supplied to said load, and adapted to generate a second
signal pulse signal for controlling the conduction state of said second
plurality of switches only if said feedback signal is above a predetermined
threshold;
’615 patent col.10 l.67 – col.11 l.5.
B. Accused Devices
BiTEK manufactures and sells inverter controllers. SPI/FSP and Lien Chang
manufacture and sell inverter modules incorporating BiTEK’s inverter controllers. O2
Micro alleged that four of BiTEK’s products (BIT3105, BIT3106, BIT3107 and BIT3193)
infringe one or more of the patents-in-suit. The parties concede that, for the purposes
of this litigation, the first three products (BIT3105, BIT3106, and BIT3107) are the same,
and the fourth (BIT3193) differs from the others in only one material respect.
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BiTEK’s inverter controllers have feedback control loops. The controllers are
capable of shutting off the feedback signal’s control over power when a feedback signal
falls below a predetermined threshold. The parties dispute whether this feature satisfies
the “only if” limitation recited by the asserted claims, which requires “a feedback control
loop circuit . . . adapted to generate a second signal pulse signal for controlling . . . [the]
switches only if said feedback signal is above a predetermined threshold.” (emphasis
added).
BiTEK submits that its inverter controllers do not satisfy this limitation in two
circumstances because, during those circumstances, the feedback signal in BiTEK’s
switch continues to control the power delivered to the load even though the feedback
signal falls below the predetermined threshold. The first circumstance is when an unlit
lamp lights up (called “start-up” or “ignition”). BiTEK asserts that, during the ignition
period, the feedback signal is below the predetermined threshold, but the feedback
circuit still controls power delivered to the load, in violation of the claims’ requirements.
This first circumstance applies to all four products. The second circumstance applies
only to the BIT3193 product, which implements a 32-microsecond delay. During this
delay period, the feedback circuit is designed to continue to rely on the feedback signal
to control the power for 32 microseconds after the feedback signal falls below the
predetermined threshold. Such a delay was purposely created to ensure that the
feedback signal would not cease to control the power to the load because of a
temporary fall below the threshold.
On appeal, BiTEK relies exclusively on these two circumstances to avoid
infringement under the claim, asserting that the “only if” limitation is therefore not
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satisfied. O2 Micro, on the other hand, asserts that this limitation is satisfied by the
accused devices. First, O2 Micro argues that the claims do not apply in the two
circumstances identified by BiTEK. Second, O2 Micro disputes BiTEK’s allegations
regarding the operation of its devices during those circumstances and, consequently,
asserts that, even if the claims apply, the accused devices still infringe.
C. District Court Proceedings
In January 2004, O2 Micro filed suit against BiTEK, SPI/FSP, and Lien Chang in
the United States District Court for the Eastern District of Texas. O2 Micro alleges that
BiTEK’s inverter controllers infringe several claims of the ’615 patent, the ’722 patent,
and the ’129 patent. While Defendants-Appellants are foreign entities that operate
abroad, Defendants-Appellants’ inverter controllers and modules are used in monitors
sold in the United States.
The district court held a Markman hearing in August 2005. The parties agreed,
for the most part, that a previously issued claim construction order (from a different case
pending before the same court) controlled in this case. See O2 Micro Int’l Ltd. v.
Sumida Corp., 2:03-CV-07 (E.D. Tex. Mar. 8, 2005) (claim construction order construing
claim language in the same patents). However, the parties presented a handful of
additional terms for the court to construe. The claim term “only if” (one of the additional
terms disputed by the parties) is the only term whose construction was appealed to this
court.
At the Markman hearing, Defendants-Appellants argued that the district court
should construe the claim term “only if,” but disagreed regarding what specific meaning
should be ascribed to it. Defendants-Appellants BiTEK and Lien Chen asserted that
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“only if” should mean “exclusively or solely in the event that,” while defendant SPI/FSP
asserted that it should mean “never except when.” In spite of the differences in word
choice, Defendants-Appellants seemed to agree that these constructions are
substantially identical in meaning. O2 Micro, on the other hand, maintained that no
construction was necessary because the claim term “only if” consists of “two simple,
plain English words.” During the hearing, the district court astutely summarized the
dispute as concerning whether or not “there can be an exception” to the “only if”
language. However, in its Markman order, the district court ruled that this term “needs
no construction” because it “has a well-understood definition, capable of application by
both the jury and this court in considering the evidence submitted in support of an
infringement or invalidity case.” O2 Micro Int’l Ltd. v. Beyond Innovation Tech. Co., No.
2:04-CV-32 (E.D. Tex. Aug. 26, 2005).
During pre-trial proceedings, BiTEK filed a motion in limine seeking to prevent O2
Micro from alleging infringement under the doctrine of equivalents as to the “only if”
limitation, asserting that prosecution history estoppel barred that theory. The district
court originally granted this motion, instructing O2 Micro to first approach the bench
before “offering any evidence relating to infringement of the ‘only if’ limitation under the
doctrine of equivalents.” O2 Micro Int’l Ltd. v. Beyond Innovation Tech. Co., No. 2:04-
CV-32 (E.D. Tex. May 2, 2006). However, after considering supplemental briefing, the
district court changed course, ruling that O2 Micro was allowed to argue that the “only if”
limitation is infringed under the doctrine of equivalents. O2 Micro Int’l Ltd. v. Beyond
Innovation Tech. Co., No. 2:04-CV-32 (E.D. Tex. May 8, 2006). Without any analysis,
the district court’s opinion simply stated, “The court . . . is persuaded by O2’s argument
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that the amendment bears only a tangential relationship to the equivalent at issue.” Id.
(also citing Insituform Techs., Inc. v. CAT Contracting, Inc., 385 F.3d 1360, 1370 (Fed.
Cir. 2004)).
At trial, the “only if” limitation was a key issue disputed by the parties. O2 Micro
presented evidence that the accused devices satisfied the “only if” limitation both
literally and under the doctrine of equivalents. Defendants-Appellants presented
evidence to the contrary. Moreover, both parties presented arguments regarding
whether or not the “only if” claim language allows exceptions.
After trial, the parties submitted proposed verdict forms that asked separate
questions regarding literal infringement and infringement under the doctrine of
equivalents. The district court generated a jury form containing general questions
regarding “infringement” and included jury instructions explaining that a claim limitation
may be satisfied either literally or under the doctrine of equivalents. After deliberations,
the jury found that each Defendant-Appellant had induced infringement of each
asserted claim of each patent. The jury also found that Lien Chang contributorily
infringed and all three Defendants-Appellants willfully infringed. Defendants-Appellants
timely appealed to this court. We have jurisdiction pursuant to 28 U.S.C. § 1295(a)(1).
II. DISCUSSION
As noted above, the district court provided a general verdict form that asked the
jury whether each defendant “infringe[d]” each of the asserted claims. The
corresponding jury instructions explained that infringement may be found either literally
or under the doctrine of equivalents. On appeal, Defendants-Appellants allege error in
both theories of infringement liability. First, Defendants-Appellants contend that the
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district court’s failure to construe the claim term “only if” was legal error that infected the
literal infringement inquiry. Second, Defendants-Appellants assert that the jury should
not have been permitted to find infringement under the doctrine of equivalents. We
address each of these arguments in turn.
A. Claim Construction
With respect to literal infringement, the parties dispute whether the district court’s
failure to construe the claim term “only if” was legal error. As a threshold matter,
however, O2 Micro argues that Defendants-Appellants waived any challenge to the
construction of “only if” by: (1) failing to object to the jury instructions as lacking a
construction of that claim term and (2) offering a different construction of the claim term
on appeal than was presented to the district court. Before addressing the claim
construction issue on the merits, we turn to these waiver arguments.
First, O2 Micro contends that Defendants-Appellants have waived any challenge
to the construction of “only if” because Defendants-Appellants failed to object to the jury
instructions as lacking a construction of that term. O2 Micro acknowledges that
Defendants-Appellants presented these arguments during the Markman hearing and
that the district court issued a claim construction order months before trial. O2 Micro
asserts, however, that a party waives its objections to a claim construction by not
objecting to the jury instructions containing (or, in this case, lacking) that construction.
In response, Defendants-Appellants argue that the purpose of a Markman
hearing is to determine the meaning of claim terms. A claim construction order always
dictates how the court will instruct the jury regarding a claim’s scope. Because these
issues were fully litigated and decided at the Markman stage of the litigation,
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Defendants-Appellants assert that no objection to the jury instruction was required to
preserve error. We agree.
“When the claim construction is resolved pre-trial, and the patentee presented
the same position in the Markman proceeding as is now pressed, a further objection to
the district court’s pre-trial ruling may indeed have been not only futile but unnecessary.”
Cardiac Pacemakers, Inc. v. St. Jude Med., Inc., 381 F.3d 1371, 1381 (Fed. Cir. 2004)
(under Seventh Circuit law). The same holds true in the Fifth Circuit. Taita Chem. Co.
v. Westlake Styrene, LP, 351 F.3d 663, 667 (5th Cir. 2003) (stating that there is no need
to object where a litigant “had previously filed sufficient objections”); Rizzo v. Children’s
World Learning Ctrs., Inc., 213 F.3d 209, 223 (5th Cir. 2000) (“Failure to object [to a
proposed jury instruction] may be disregarded if the party’s position has previously been
made clear to the court and it is plain that a further objection would have been
unavailing.”); Bender v. Brumley, 1 F.3d 271, 277 (5th Cir. 1993) (finding “oral on-the-
record objections to the jury charge” were not required to preserve objection where
appellant “had earlier filed written objections to the proffered jury instructions”). The
district court in this case, as in Cardiac Pacemakers, rendered a claim construction
order following a Markman hearing during which the parties’ positions were fully
litigated. Because Defendants-Appellants’ position was previously made clear to the
district court and the district court did not clearly indicate that it was open to changing its
claim construction, Defendants-Appellants need not have renewed their objections by
reasserting them when jury instructions were given.
Second, O2 Micro also asserts that Defendants-Appellants have waived their
proposed claim constructions of “only if” by asserting a new construction on appeal.
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Contending that Defendants-Appellants’ current construction is that “only if” allows for
“no exceptions,” O2 Micro notes that the word “exception” was never used in
Defendants-Appellants’ claim construction briefs. Defendants-Appellants respond by
re-affirming the construction proposed to the district court—namely, “only if” means
“solely or exclusively in the event that.” Defendants-Appellants argue that, while the
arguments advanced in support of their construction may have changed, the
construction itself remains the same. Defendants-Appellants note that these new
arguments simply recognize that the effect of their proposed construction is to prohibit
exceptions to the “only if” limitation.
We agree with Defendants-Appellants that no waiver has occurred. While “a
waiver may occur if a party raises a new issue on appeal . . . . [a] waiver will not
necessarily occur . . . if a party simply presented new or additional arguments in support
of ‘the scope of its claim construction . . . .’” CCS Fitness, Inc. v. Brunswick Corp., 288
F.3d 1359, 1370-71 (Fed. Cir. 2002) (citation omitted). Defendants-Appellants propose
the same construction on appeal as was presented to the district court. While
Defendants-Appellants employ different arguments in support, these new arguments
simply incorporate an understanding of the parties’ dispute that has developed through
the course of litigation. At the claim construction hearing, the district court astutely
recognized that the dispute “boils down to whether [the court] believe[s] there can be an
exception.” Thus, we conclude Defendants-Appellants have not waived these
arguments.
Accordingly, we turn to the merits of Defendants-Appellants’ appeal of the district
court’s failure to construe the claim term “only if.” On appeal, Defendants-Appellants
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argue that the district court’s failure to construe the claim term “only if” was error
because the parties disputed whether or not this claim language allows for exceptions.
Defendants-Appellants assert that, because this presents an issue of claim
construction, it is a question of law that must be decided by the court. In Defendants-
Appellants’ view, by failing to provide a construction of this term, the district court
effectively submitted a legal question to the jury. Defendants-Appellants also argue that
the district court erred by allowing the jury to reach a verdict based upon an erroneous
legal conclusion—namely, that “only if” allows exceptions.
O2 Micro counters that the claim term “only if” does not need to be construed
because the parties agree that the term is a “common term” with a “common meaning.”
O2 Micro notes that this court has repeatedly held that a district court is not obligated to
construe terms with ordinary meanings,2 lest trial courts be inundated with requests to
parse the meaning of every word in the asserted claims.
The purpose of claim construction is to “determin[e] the meaning and scope of
the patent claims asserted to be infringed.” Markman v. Westview Instruments, Inc., 52
F.3d 967, 976 (Fed. Cir. 1995) (en banc), aff’d 517 U.S. 370 (1996). When the parties
raise an actual dispute regarding the proper scope of these claims, the court, not the
jury, must resolve that dispute. See id. at 979 (holding that claim construction is a
matter of law).
2 E.g., Biotec Biologische Naturverpackungen GmbH & Co. KG v. Biocorp,
Inc., 249 F.3d 1341, 1349 (Fed. Cir. 2001) (finding no error in non-construction of
“melting”); Mentor H/S, Inc. v. Med. Device Alliance, Inc., 244 F.3d 1365, 1380 (Fed.
Cir. 2001) (finding no error in court’s refusal to construe “irrigating” and “frictional heat”).
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Words of a claim are generally given their ordinary and customary meaning,
which is the meaning a term would have to a person of ordinary skill in the art after
reviewing the intrinsic record at the time of the invention. Phillips v. AWH Corp., 415
F.3d 1303, 1312-13 (Fed. Cir. 2005) (en banc). “In some cases, the ordinary meaning
of claim language . . . may be readily apparent even to lay judges, and claim
construction in such cases involves little more than the application of the widely
accepted meaning of commonly understood words.” Id. at 1314. However, in many
cases, the meaning of a claim term as understood by persons of skill in the art is not
readily apparent. Id.
In this case, the parties dispute whether or not the “only if” limitation allows for
exceptions. O2 Micro asserts that the claims would be understood by one of ordinary
skill in the art to only apply to “the steady state operation of the switching circuit.”
Defendants-Appellants disagree and submit that the claims apply at all times—not just
to steady state operation—with no exceptions. There are two circumstances in which
Defendants-Appellants assert that the “only if” limitation is not satisfied: (1) the pre-
ignition, start-up phase, and (2) a 32-microsecond delay. Accordingly, Defendants-
Appellants seek a construction that specifies that “only if” has no exceptions and is not
limited to “steady state operation.”
During the claim construction hearing, the district court acknowledged that this
dispute over the scope of the asserted claims “boils down to whether I believe there can
be an exception.” However, the district court declined to construe this term, stating:
The term “only if” needs no construction aside from the construction
previously adopted by the court for the phrases in which the term appears.
It is true, as defendants argue, that Elekta Instruments, S.A. v. O.U.R.
Scientific International, Inc., 214 F.3d 1302 (Fed. Cir. 2000), applies the
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ordinary meaning of “only” (being solely; exclusively) to a claim term and
evaluates the evidence in that light. Nothing in Elekta Instruments,
however, requires the court to construe claim terms that have a well-
understood meaning. “Only if” has a well-understood definition, capable of
application by both the jury and this court in considering the evidence
submitted in support of an infringement or invalidity case.
O2 Micro Int’l Ltd. v. Beyond Innovation Tech. Co., No. 2:04-CV-32, slip op. at 2 (E.D.
Tex. Aug. 26, 2005). We find this decision to be in error because, while Elekta
Instruments may not require the court to construe this claim term, we find that Markman
does.
The parties presented a dispute to the district court regarding the scope of the
asserted claims—What do the patents mean when they say that the feedback signal
controls power “only if said feedback signal is above a predetermined threshold”? O2
Micro contends that this “only if” limitation only applies during “steady state operation,”
while Defendants-Appellants contend that the “only if” limitation applies at all times
without exception. This dispute over the scope of the asserted claims is a question of
law. In deciding that “‘only if’ needs no construction” because the term has a “well-
understood definition,” the district court failed to resolve the parties’ dispute because the
parties disputed not the meaning of the words themselves, but the scope that should be
encompassed by this claim language.
A determination that a claim term “needs no construction” or has the “plain and
ordinary meaning” may be inadequate when a term has more than one “ordinary”
meaning or when reliance on a term’s “ordinary” meaning does not resolve the parties’
dispute. In this case, for example, the parties agreed that “only if” has a common
meaning, but then proceeded to dispute the scope of that claim term, each party
providing an argument identifying the alleged circumstances when the requirement
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specified by the claim term must be satisfied (e.g., at all times or during steady state
operation). In this case, the “ordinary” meaning of a term does not resolve the parties’
dispute, and claim construction requires the court to determine what claim scope is
appropriate in the context of the patents-in-suit. This court has construed other
“ordinary” words for these and other related reasons. See, e.g., Nystrom v. TREX Co.,
424 F.3d 1136, 1143 (Fed. Cir. 2005) (construing “board” in light of intrinsic record);
Unitherm Food Sys., Inc. v. Swift-Eckrich, Inc., 375 F.3d 1341, 1350 (Fed. Cir. 2004)
(construing “golden brown” even though colors “are commonly used terms with well-
accepted plain definitions that rarely need construction”), rev’d on other grounds, 546
U.S. 394 (2006); Toro Co. v. White Consol. Indus., Inc., 199 F.3d 1295, 1299 (Fed. Cir.
1999) (construing “cover,” “included,” “attachment,” and “removable”).
When the district court failed to adjudicate the parties’ dispute regarding the
proper scope of “only if,” the parties presented their arguments to the jury. By failing to
construe this term, the district court left the jury free to consider these arguments. O2
Micro presented expert testimony to support its argument that the claim limitation “only
if” applies only during certain periods of operation—“normal operation”—and that this
claim limitation “has nothing to do with start-up.” O2 Micro also brought the inventor of
the patents-in-suit to testify regarding the meaning of “only if”:
Q: What did the additional language, “only if said feedback signal is
above a predetermined threshold,” pertain to?
A: Actually, in my opinion, specification did not change. “Only if,”
between my patent lawyer and examiner, they added in to try to
clarify, make the entire invention more easier to understand. I think
that’s what it is. To me, there’s no change to my original invention’s
intent.
. . . .
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Q: So if the only time it makes any sense to use feedback to control
power to a lamp is after it’s lit, after this threshold is reached, what
did you give up, if anything, by adding the “only if” language to the
claims?
A: I don’t think I gave up anything. I think it just make it clear that you
and I can understand.
Only when the lamp is lit . . . we control power at that time.
J.A. 6550-51. Likewise, Defendants-Appellants argued to the jury that “only if” does not
allow for exceptions. For the reasons stated, the parties’ arguments regarding the
meaning and legal significance of the “only if” limitation were improperly submitted to
the jury.3
We, however, recognize that district courts are not (and should not be) required
to construe every limitation present in a patent’s asserted claims. See, e.g., Biotec
Biologische Naturverpackungen GmbH & Co. KG v. Biocorp, Inc., 249 F.3d 1341, 1349
(Fed. Cir. 2001) (deciding that disputed issue was the proper application of a claim term
to an accused process rather the scope of the term); U.S. Surgical Corp. v. Ethicon,
Inc., 103 F.3d 1554, 1568 (Fed. Cir. 1997) (Claim construction “is not an obligatory
exercise in redundancy.”). Rather, “[c]laim construction is a matter of resolution of
disputed meanings and technical scope, to clarify and when necessary to explain what
the patentee covered by the claims, for use in the determination of infringement.” U.S.
3 We note, in passing, that the parties’ claim construction arguments are
fraught with problems. First, an inventor’s self-serving statements are rarely relevant to
the proper construction of a claim term. Bell & Howell Document Mgmt. Prods v. Altek
Sys., 132 F.3d 701, 706 (Fed. Cir. 1997). Second, the parties’ claim construction
arguments appear to contain no support from the intrinsic record. See Phillips, 415
F.3d at 1314-19 (emphasizing the importance of the intrinsic record in claim
construction). These deficiencies support the rationale underlying the rule that the
court, and not the jury, should resolve claim construction disputes. See Markman v.
Westview Instruments, Inc., 517 U.S. 370, 388-89 (1996) (explaining why judges “are
the better suited to find the acquired meaning of patent terms”).
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Surgical, 103 F.3d at 1568. When the parties present a fundamental dispute regarding
the scope of a claim term, it is the court’s duty to resolve it. Because we determine that
the district court is in the best position to determine the proper construction of this claim
term in the first instance, we remand for further proceedings consistent with this
opinion.4
B. Doctrine of Equivalents
We turn now to Defendants-Appellants’ arguments with respect to the doctrine of
equivalents.5 “The doctrine of equivalents allows the patentee to claim those
insubstantial alterations that were not captured in drafting the original patent claim but
which could be created through trivial changes.” Festo Corp. v. Shoketsu Kinzoku
Kogyo Kabushiki Co., 535 U.S. 722, 733 (2002). However, when a patent claim is
narrowed during prosecution, prosecution history estoppel may limit application of the
doctrine of equivalents. Int’l Rectifier Corp. v. IXYS Corp., 515 F.3d 1353, 1358 (Fed.
Cir. 2008). “[W]e review issues relating to the application of prosecution history
4 O2 Micro also argues that, if the failure to construe “only if” was error, it
was not prejudicial error because O2 Micro presented evidence sufficient to prove literal
infringement under the construction proposed by Defendants-Appellants. Defendants-
Appellants, on the other hand, contend that a construction of “only if” would certainly
have changed the result. We do not find the infringement evidence to be clearly in favor
of either party, and cannot conclude that the lack of a construction did not result in
harm.
5 O2 Micro asserts that the jury verdict, which found “infringement,” should
not be vacated unless we find error in both theories of liability (i.e., literal infringement
and infringement under the doctrine of equivalents). Under O2 Micro’s theory, the jury
verdict must be upheld if the jury could have found infringement under either theory
because Defendants-Appellants failed to object to the district court’s use of a general
verdict form. Because we find error in both literal infringement and infringement under
the doctrine of equivalents, we need not decide this issue.
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estoppel de novo.” Conoco, Inc. v. Energy & Envtl. Int’l, L.C., 460 F.3d 1349, 1357
(Fed. Cir. 2006).
On appeal, Defendants-Appellants argue that the district court erred in allowing
the jury to find infringement under the doctrine of equivalents. Defendants-Appellants
contend that, because the claim term “only if” was added during prosecution to
overcome a prior art rejection, the Festo presumption should apply. According to
Defendants-Appellants, because O2 Micro has failed to rebut this presumption, it should
not have been allowed to argue that the accused devices infringe under the doctrine of
equivalents. Accordingly, Defendants-Appellants find error in the jury instruction
allowing for infringement under the doctrine of equivalents and O2 Micro’s arguments at
trial alleging infringement on this basis.
O2 Micro agrees that the addition of “only if” constituted a narrowing amendment
made for a substantial reason relating to patentability. However, O2 Micro appears to
offer two alternate theories for why Festo should not apply. At the district court, O2
Micro attempted to rebut the Festo presumption by arguing that the alleged equivalent is
merely tangential to this amendment. On appeal, O2 Micro supplements this argument,
asserting that the doctrine of equivalents should presumptively be available for other
claim terms (namely, “feedback signal” and “adjustment”) because these terms were not
added by amendment.
We agree with Defendants-Appellants that prosecution history estoppel prevents
application of the doctrine of equivalents for the “only if” limitation. The parties agree
that the “only if” limitation was added to the claims by a “narrowing amendment . . .
made for a substantial reason relating to patentability.” See Festo Corp. v. Shoketsu
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Kinzoku Kogyo Kabushiki Co., 344 F.3d 1359, 1367 (Fed. Cir. 2003) (en banc). Thus,
the Festo presumption applies to this limitation, and, in order to avail itself of the
doctrine of equivalents, O2 Micro must rebut the “presumption that the patentee has
surrendered all territory between the original claim limitation and the amended claim
limitation.” Id.; accord Festo, 535 U.S. at 740 (“[T]he patentee should bear the burden
of showing that the amendment does not surrender the particular equivalent in
question.”). The Supreme Court provided three vehicles6 through which a plaintiff may
do so. Festo, 344 F.3d at 1368. Neither party has argued either that the equivalent
was unforeseeable or that there was “some other reason” why the patentee could not
have described the alleged equivalent. See id. Accordingly, we turn directly to the
issue of whether the rationale behind the narrowing amendment was merely tangential
(i.e., peripheral, or not directly relevant) to the alleged equivalent. See id.
“[T]he inquiry into whether a patentee can rebut the Festo presumption under the
‘tangential’ criterion focuses on the patentee’s objectively apparent reason for the
narrowing amendment.” Id. at 1369 (emphasis added). In order to maintain the public
notice function of a patent, “that reason should be discernible from the prosecution
history record.” Id.; see id. at 1371-72 (holding that amendment was not tangential to
accused equivalent because the prosecution history reveals no reason for the
amendment); Biagro W. Sales, Inc. v. Grow More, Inc., 423 F.3d 1296, 1306 (Fed. Cir.
6 The three vehicles are: “(1) ‘the alleged equivalent would have been
unforeseeable at the time . . . the narrowing amendment’ was made; (2) ‘the rationale
underlying the narrowing amendment bore no more than a tangential relation to the
equivalent’ at issue; and (3) ‘there was “some other reason” suggesting that the
patentee could not reasonably have been expected to have described the alleged
equivalent.’” Honeywell Int’l Inc. v. Hamilton Sundstrand Corp., 370 F.3d 1131, 1140
(Fed. Cir. 2004) (quoting Festo, 344 F.3d at 1368).
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2005) (“[W]hether the patentee has overcome the presumption on this ground is
determined by the court on the basis of the public record.”). “[I]f the patentee fails to
rebut the Festo presumption, then prosecution history estoppel bars the patentee from
relying on the doctrine of equivalents for the accused element.” Festo, 344 F.3d at
1367.
In ruling that the doctrine of equivalents was available with respect to the “only if”
limitation, the district court simply stated that it was “persuaded by O2’s argument that
the amendment bears only a tangential relationship to the equivalent at issue.” O2
Micro Int’l Ltd. v. Beyond Innovation Tech. Co., No. 2:04-CV-32 (E.D. Tex. May 8,
2006). Without the benefit of the district court’s explanation of its rationale, we examine
the prosecution history and parties’ arguments to the district court.
During prosecution, the examiner rejected the ’615 patent as obvious in light of
Gradzki. Gradzki discloses an inverter controller that regulates lamp power irrespective
of the level of the feedback signal. In response to the examiner’s rejection, O2 Micro
added the “only if” language to the independent claims, amending claim 1 of the ’615
patent, for example, to require that the feedback control loop circuit controls the
conduction state of the switches “only if said feedback signal is above a predetermined
threshold.” O2 Micro provided little explanation for the amendment, merely stating:
[T]he Examiner looks to Gradzki et al. as disclosing a feedback technique
to generate a feedback signal indicative of power being supplied to the
load. Significantly, however, Gradzki et al. discloses a feedback system,
maintains [sic] the voltage at the CRECT pin equal to the voltage at the
DIN pin, thereby regulating lamp power (Gradzki et al., column 4, lines 64-
67).
In contrast to [the prior art], Applicant’s invention of independent
claim 1 requires, inter alia, a DC/AC converter circuit that includes a
feedback control loop circuit between the load and the drive circuitry
receiving a feedback signal indicative of power supplied to the load and
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adapted to generate a second pulse signal for controlling the conduction
state of a second plurality of switches only if said feedback signal is above
a predetermined threshold. Applicant’s invention of independent claim 18
has been similarly amended.
J.A. 7626.
To begin, O2 Micro correctly notes that prosecution history estoppel is a “flexible”
doctrine, not a “rigid” one. See Festo, 535 U.S. at 738. O2 Micro then asserts that “the
‘only if’ language distinguished Gradzki by claiming a feedback system responsive to
the feedback signal’s being above or below a predetermined threshold,” which is
tangential to whether or not the feedback signal is used during “ignition of the lamp” and
other non-steady state operations. Essentially, O2 Micro argues that exceptions to the
“only if” limitation (e.g., during non-steady state operations) are merely tangential to the
limitation itself. We find this argument to be without merit. The “objectively apparent”
reason for the patentee’s amendment was to require the feedback circuit to be
operational “only if said feedback signal is above a predetermined threshold,” as the
claim language clearly states. No other reason is provided or suggested by the
prosecution history. The equivalent alleged by O2 Micro is a feedback circuit that,
during non-steady state operations, may be operational even though the claim language
is not satisfied (i.e., the feedback signal is not above the predetermined threshold). This
equivalent is simply not tangential to the reason for the amendment. Thus, it was error
for the district court to allow the jury to consider infringement under the doctrine of
equivalents.
On appeal, O2 Micro supplements its argument supporting the doctrine of
equivalents instruction by asserting that the instruction was proper because the jury
could have found that other claim terms were infringed by the doctrine of equivalents.
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Noting that the terms “feedback signal” and “adjustment” were present in the originally
filed claims, O2 Micro argues that its expert’s equivalents analysis focused on these
terms, not the “only if” claim language. O2 Micro also alleges that the doctrine of
equivalents instruction would not be error so long as the jury could have found any
limitation to be met by equivalents.
The record, however, does not support this argument. The district court’s
equivalents ruling focused on “only if,” not “feedback signal” or “adjustment.”
Defendants-Appellants original motion in limine sought to prevent O2 Micro from
arguing equivalents to “only if.” The district court’s decisions recognize that this was the
claim term at issue for the purposes of these discussions. At trial, O2 Micro asked its
expert, Dr. Rhyne: “[D]o the ‘only if’ limitations also infringe under the doctrine of
equivalents?” J.A. 6328. In response, Dr. Rhyne explained why the reaction of the
circuit was “essentially the same as it would be even if the feedback were not present.”
Id.
O2 Micro points to no portion of the record where it argued that the accused
devices satisfied the “feedback signal” or “adjustment” limitations under the doctrine of
equivalents. In O2 Micro’s brief, it asserts that only three pages of trial testimony
directly addressed the issue of equivalents; however, in these pages, O2 Micro’s expert
opines that the asserted equivalents are insubstantially different from the “only if”
limitation, with no discussion regarding either “feedback signal” or “adjustment.” While
O2 Micro points to two additional excerpts of the trial transcript, the generalized
testimony regarding “virtually insignificant” current flow is insufficient to establish that
either the “feedback signal” or “adjustment” limitations were infringed under the doctrine
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2007-1302, -1303, -1304 24
of equivalents. See Warner-Jenkinson Co. v. Hilton Davis Chem. Co., 520 U.S. 17, 29
(1997) (“[T]he doctrine of equivalents must be applied to individual elements of the
claim, not to the invention as a whole.”); Tex. Instruments, Inc. v. Cypress
Semiconductor Corp., 90 F.3d 1558, 1567 (Fed. Cir. 1996) (“Generalized testimony as
to the overall similarity between the claims and the accused infringer's product or
process will not suffice [to prove infringement under the doctrine of equivalents].”).
Accordingly, we agree with Defendants-Appellants that the district court erred in
allowing the jury to find infringement under the doctrine of equivalents. Because we
vacate the jury verdict, the remaining issues raised by Defendants-Appellants (which
are premised on that jury verdict) are rendered moot.
III. CONCLUSION
For the above reasons, we vacate the jury verdict, the final judgment of
infringement, and the permanent injunction, and we remand to the district court for
further proceedings consistent with this opinion.
COSTS
Each party shall bear its own costs.
VACATED AND REMANDED

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1303, -1304 O2 Micro International Limited v. Beyond Innovation Technology Co., Ltd.

Gesamter Gesetzestext

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