United States Court of Appeals for the Federal Circuit 

2008-1128, -1136 

MONOLITHIC POWER SYSTEMS, INC., 

Plaintiff/Counterclaim DefendantCross Appellant, 

and 

ASUSTEK COMPUTER, INC., 

Counterclaim Defendant-Cross 

Appellant, 

and 

ADVANCED SEMICONDUCTOR MANUFACTURING CORPORATION, LTD., 

Counterclaim Defendant- 

 Appellee, 

v. 

O2 MICRO INTERNATIONAL LIMITED, 

Defendant/CounterclaimantAppellant. 

 Dan L. Bagatell, Perkins Coie Brown & Bain P.A., of Phoenix, Arizona, argued for 

plaintiff/counterclaim defendant-cross appellant. With him on the brief were Mark A. 

Flagel and Dean G. Dunlavey, Latham & Watkins LLP, of Los Angeles, California. 

 Thomas J. Friel, Jr., Cooley Godward Kronish LLP, of Palo Alto, California, 

argued for counterclaim defendant-cross appellant ASUSTeK Computer, Inc., and 

counterclaim defendant-appellee Advanced Semiconductor Manufacturing Corporation 

Limited. 

 Henry C. Bunsow, Howrey LLP, of San Francisco, California, argued for 

defendant-counterclaimant-appellant. With him on the brief were Korula T. Cherian and 

Duane H. Mathiowetz, and Henry C. Su and Richard C. Lin, East Palo Alto, California; 

and Richard Stanley, of Houston, Texas 

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

Judge Claudia Wilken 
United States Court of Appeals for the Federal Circuit

 

2008-1128, -1136 

MONOLITHIC POWER SYSTEMS, INC., 

Plaintiff/Counterclaim DefendantCross Appellant, 

and 

ASUSTEK COMPUTER, INC., 

Counterclaim Defendant-Cross 

Appellant, 

and 

ADVANCED SEMICONDUCTOR MANUFACTURING CORPORATION, LTD., 

Counterclaim DefendantAppellee, 

v. 

O2 MICRO INTERNATIONAL LIMITED, 

Defendant/CounterclaimantAppellant. 

Appeals from the United States District Court for the Northern District of California in 

Consolidated Case Nos. 04-CV-2000 and 06-CV-2929, Judge Claudia Wilken. 

___________________________ 

DECIDED: MARCH 5, 2009 

___________________________ 

Before RADER, PLAGER, and GAJARSA, Circuit Judges. 

RADER, Circuit Judge. 

 In a jury trial, the United States District Court for the Northern District of California 

appointed an expert witness under Fed. R. Evid. 706(a) to testify on contested issues. 
Based on that testimony and considerable other evidence, the jury found all asserted 

claims of O2 Micro International Limited’s (“O2 Micro’s”) U.S. Patent No. 6,396,722 

(“’722 patent”) obvious under 35 U.S.C. § 103. Because the district court did not abuse 

its discretion in appointing an expert under the Federal Rules, and because this court 

finds no error in the district court’s denial of O2 Micro’s motion for judgment as a matter 

of law on obviousness, this court affirms the judgment of the district court. 

I 

 O2 Micro’s ’722 patent, entitled “High-Efficiency Adaptive DC/AC converter,” 

relates to power inverter circuitry for laptop computers. Laptops must be capable of 

operating on direct current (“DC”) power sources such as batteries. However, the cold 

cathode fluorescent lamps (“CCFLs”) for backlit laptop screens require high voltage, 

alternating current (“AC”) power. The disclosed circuitry converts low voltage DC 

battery power into higher voltage AC power with the help of feedback circuitry that 

precisely controls the amount of power delivered from the battery to the CCFL. Figure 2 

of the ’722 patent illustrates the converter circuit in question. 

2008-1128, -1136 2
Switches A-D define a “full-bridge” switch configuration. Diagonally opposing 

pairs of switches (A and D, B and C) define alternating conduction paths for current to 

reach the CCFL load (20) from the battery source V1 (12). The full bridge ‘chops up’ 

direct current into alternating current by requiring current to alternately flow through the 

A-D and B-C paths. By selectively turning on the pairs of switches, the circuitry controls 

the amount of power delivered to the load. 

 A feedback signal (“FB”) indicates the current being supplied to the CCFL at any 

given time. In turn, a reference signal (“REF”) indicates desired load conditions. A 

comparator (32) compares the feedback signal with the reference signal to produce a 

comparison signal (“CMP”). This CMP signal triggers adjustments to the load power by 

adjusting the amount of overlap between the switches. Thus, the circuit regulates 

outputted power much as a home thermostat maintains a steady-state temperature. 

 Additionally, the converter circuit includes over-voltage protection mechanisms 

that reduce the power supplied to the CCFL in short-circuit or open-circuit situations. As 

shown in Figure 2, a current sensing comparator (42) compares the presently supplied 

current (FB) with a reference value reflecting the minimum or maximum current 

permitted by the system. If FB is within a permissible range, the comparator allows the 

current to flow unhindered through the output switch (38). However, when FB is in an 

undesirable range, the comparator substitutes a minimum voltage (“Vmin”) at the output 

switch (38), reducing the CCFL’s power to a safe level. 

II 

 In May 2004, Monolithic Power Systems, Inc. (“MPS”) filed suit in the Northern 

District of California seeking a declaratory judgment finding O2 Micro’s ’722 patent 

2008-1128, -1136 3
invalid, not infringed, and unenforceable. O2 Micro counterclaimed for infringement and 

added Advanced Semiconductor Manufacturing Corp. (“ASMC”), MPS’s foundry, as a 

counter-defendant. O2 Micro’s counterclaim alleged that several models of MPS 

inverter controllers infringe claims 1, 2, 9, 12, 14 and 18 of the ’722 patent. 

Five months later, O2 Micro sued MPS in the Eastern District of Texas, accusing 

MPS of infringing U.S. Patent No. 6,804,129 (“the ’129 patent”). O2 Micro later 

amended its complaint to also accuse ASMC of infringing the ’129 patent and to accuse 

ASUSTeK Computer Inc. (“ASUS”) of infringing U.S. Patent No. 6,259,615 (“the ’615 

patent”), as well as the ’722 and ’129 patents. In March 2006, the Texas court 

transferred O2 Micro’s case to the Northern District of California, which in turn 

consolidated the two cases. The district court in California then dismissed O2 Micro’s 

claims regarding the ’129 patent with prejudice, and granted summary judgment of noninfringement of the ’615 patent in favor of ASUS. 

 On Oct. 27, 2006, the district court convened a case management conference 

and set a trial date for Apr. 30, 2007. At the conference, the court expressed its 

frustration with the technical complexities of the ’722 patent. 

On the technical issues here . . . I find this extremely difficult to 

understand. And the notion that a jury is going to understand it, to me, is 

foolishness. You can talk for months and the jury isn’t really going to 

understand this in the sense of being able to make a reasoned, rational 

decision about it. 

They will make a decision, we hope. Maybe they will hang because they’ll 

say that we can’t possibly understand this, but in my experience, they 

make a decision. But what is it based on? . . . It is kind of trial by ordeal or 

by sort of a champion, like a jousting contest rather than on the actual 

scientific merits of who is right and who is wrong. 

2008-1128, -1136 4
Hr’g Tr. 35:3-8, Oct. 27, 2006. The court entertained the idea of appointing an 

independent expert under Fed. R. Evid. 706 to testify “on the electrical engineering 

aspects” of the case. Id. at 35:22. This expert, in the court’s estimation, “would 

essentially, I can’t say decide the case, but would testify and [the jury] would be told 

‘This is the court’s expert on these points.’” Id. at 36:2-4. O2 Micro objected, while 

MPS expressed its approval of the idea. 

 On Jan. 17, 2007, the district court ordered the parties to confer about 

candidates to serve as the Rule 706 expert. The parties ultimately agreed, after a 

series of disagreements, upon an expert, Dr. Enrico Santi. The district court outlined a 

protocol detailing what information to provide Dr. Santi and when to complete discovery 

regarding his opinions. 

 Trial commenced as scheduled in April 2007. MPS and the other appellees 

presented evidence that the asserted claims of the ’722 patent were obvious under 35 

U.S.C. § 103. Further, MPS presented evidence that the ’722 patent was invalid under 

the on-sale bar of 35 U.S.C. § 102(b). The court-appointed expert, Dr. Santi, offered 

testimony largely consistent with MPS’s theory of the case, including MPS’s position 

that it did not infringe O2 Micro’s asserted claims. The district court instructed the jury 

that Dr. Santi was “an independent witness retained by the parties jointly at the court’s 

direction to assist in explaining the technology at issue in this case.” Trial Tr. 96:21-24, 

Apr. 30, 2007. 

 On May 15, 2007, the jury rendered a verdict favorable to MPS and the 

appellees. The jury found the asserted claims invalid under both MPS’s obviousness 

and on-sale bar theories. Additionally, the jury found no literal infringement of the 

2008-1128, -1136 5
claims, but found infringement under the doctrine of equivalents as to claims 12 and 14. 

The district court denied O2 Micro’s motions for a new trial and for judgment as a matter 

of law. Monolithic Power Sys., Inc. v. O2 Micro Int’l Ltd., No. C 05-2000 CW, 2007 WL 

3231709, at *7 (N.D. Cal. Oct. 30, 2007). This court has jurisdiction over O2 Micro’s 

timely appeal under 28 U.S.C. § 1295(a)(1). 

III 

 The Federal Rules of Evidence allow a court to appoint an expert either “on its 

own motion or on the motion of any party.” Fed. R. Evid. 706(a). Rule 706(a) provides: 

The court may appoint any expert witnesses agreed upon by the parties, 

and may appoint expert witnesses of its own selection . . . A witness so 

appointed shall be informed of the witness’ duties by the court in writing, a 

copy of which shall be filed with the clerk, or at a conference in which the 

parties shall have opportunity to participate. A witness so appointed shall 

advise the parties of the witness’ findings, if any; the witness’ deposition 

may be taken by any party; and the witness may be called to testify by the 

court or any party. The witness shall be subject to cross-examination by 

each party, including a party calling the witness. 

Id.

The appointment of an independent expert is a procedural ruling reviewable 

under regional circuit law. See TechSearch L.L.C. v. Intel Corp., 286 F.3d 1360, 1376-

77 (Fed. Cir. 2002) (stating standard of review regarding the appointment of a non-Rule 

706 technical advisor). The United States Court of Appeals for the Ninth Circuit reviews 

the decision to appoint a Rule 706 expert for an abuse of discretion. Walker v. Am.

Home Shield Long Term Disability Plan, 180 F.3d 1065, 1071 (9th Cir. 1999); see also

Daubert v. Merrell Dow Pharms. Inc., 509 U.S. 579, 595 (1993) (stating in dicta that 

“Rule 706 allows the court at its discretion to procure the assistance of an expert of its 

own choosing.”). 

2008-1128, -1136 6
While commentators have observed that district courts rarely make Rule 706 

appointments, see, e.g., 4 Jack B. Weinstein & Margaret A. Berger, Weinstein’s Federal 

Evidence § 706.02[2] (2d ed. 2005) (“It is indisputable that court appointment of experts 

is a rarity.”); 29 Charles Alan Wright et al., Federal Practice and Procedure § 6304 (2d 

ed. 2002) (“The exercise of Rule 706 powers is rare under virtually any 

circumstances.”), this court acknowledges that the Federal Rules do authorize those 

appointments. See, e.g., United States v. Green, 544 F.2d 138, 145 (3d Cir. 1976) 

(“[T]he inherent power of a trial judge to appoint an expert of his own choosing is 

clear.”); Wright, supra, § 6302 (“The provision is a specific application of the general 

power of judges under Rule 614 to call and interrogate witnesses.”); 1 Charles 

McCormick, McCormick on Evidence § 8 (4th ed. 1992) (discussing a judge’s “ancient 

power to call an expert . . . to give impartial testimony to aid him or the jury in resolving 

a scientific issue.”); Fed. R. Evid. 706 advisory committee’s note (“The inherent power 

of a trial judge to appoint an expert of his own choosing is virtually unquestioned.”). 

 O2 Micro argues that the district court’s appointment of Dr. Santi as an 

independent expert unduly burdened its Seventh Amendment right to a trial by jury. 

According to O2 Micro, the district court appointed Dr. Santi because it believed that the 

technical issues were too complex for a jury, in violation of established Ninth Circuit 

precedent that there is no “complexity exception” to a litigant’s Seventh Amendment 

rights. See, e.g., In re U.S. Fin. Sec. Litig., 609 F.2d 411, 432 (9th Cir. 1979) (“[W]e do 

not believe any case is so overwhelmingly complex that it is beyond the abilities of a 

jury.”). This court’s review of this record, however, detects no denial or encumbrance of 

O2 Micro’s jury demand or Seventh Amendment rights. Although the district court’s 

2008-1128, -1136 7
extemporaneous comments at the case management conference suggested a belief 

that the independent expert would greatly influence the jury’s determination, the district 

court properly administered the standards set by Rule 706. 

In accord with Rule 706(a), the court allowed the parties to show cause why an 

expert witness should not be appointed, and over O2 Micro’s objections, instructed the 

parties to nominate candidates and confer upon a mutually agreeable witness. Order 

Concerning Court-Appointed Expert, Jan. 17, 2007. Further in accord with 706(a), the 

district court provided detailed written instructions to Dr. Santi regarding his duties, and 

ordered Dr. Santi to make himself available for depositions and for examination at trial. 

Monolithic Power Sys. Inc. v. O2 Micro Int’l Ltd., No. C 04-2000 CW (N.D. Cal. Mar. 12, 

2007) (order concerning duties and instructions for court-appointed expert). In accord 

with 706(b), the court instructed the parties to share Dr. Santi’s reasonable fees and 

expenses. Id. And as per 706(d), the court did not limit in any way the parties’ ability to 

call their own experts, and allowed these experts to attack, support, or supplement the 

testimony of Dr. Santi. 

 The record shows that the trial court gave Dr. Santi only thirty-five days to review 

all relevant materials and prepare a report. The strictures of this time frame, however, 

do not amount to an abuse of discretion. Dr. Santi testified repeatedly that he had 

enough time to complete his analysis. See, e.g., Trial Tr. 345, May 1, 2007. Dr. Santi 

spent over 75 hours on his analysis, in addition to the time he spent writing a 27-page 

report including several detailed claim charts. Id. at 245. Further, he made himself 

available for depositions and met with counsel for both sides before trial to prepare a 

technology tutorial for the court. 

2008-1128, -1136 8
This court does not perceive an abuse of discretion in the district court’s 

disclosure of Dr. Santi’s independent status to the jury. The framers of the Federal 

Rules expressly contemplated: “[I]n the exercise of its discretion, the court may 

authorize disclosure to the jury of the fact that the court appointed the expert witness.” 

Fed. R. Evid. 706(c). The district court properly exercised this discretion, taking care to 

instruct the jury that it should not assign Dr. Santi’s opinion greater inherent weight on 

accord of his independent status. 

You should not give any greater weight to Professor Santi’s opinion testimony 

than to the testimony of any other witness simply because the court ordered 

the parties to retain an independent witness. In evaluating his opinion, you 

should carefully assess the nature of and basis for Professor Santi’s opinion 

just as you would do with any other witness’ opinion. 

Trial Tr. 96:23-97:4, Apr. 30, 2007. Of note, the jury’s verdict did not entirely track Dr. 

Santi’s opinions. Whereas Dr. Santi opined that only claim 12 of the ’722 patent was 

obvious, the jury found all claims obvious. Moreover, whereas Dr. Santi opined that 

only claim 12 was infringed under the doctrine of equivalents, the jury found both claims 

12 and 14 infringed under the doctrine. 

 Ultimately, O2 Micro’s arguments that Dr. Santi’s testimony relieved the jury of its 

tasks are policy arguments against Rule 706. However, Congress entertained and 

rejected these arguments during the framing of Rule 706. See, e.g., Hearings on 

Proposed Rules of Evidence Before the Subcomm. on Criminal Justice of the H. Comm. 

On the Judiciary (Supp.), 93d Cong., 1st Sess., ser. 2, 142 (1973) (Position Paper of 

Ass’n of Trial Lawyers of Am.) (“Perhaps the most fundamental flaw in the proposed 

rule is its willingness to depart from fundamental belief in the efficacy of the jury system 

as such.)”; id. at 238 (Letter from Thomas A. Wallace) (“This is contrary to the advocacy 

2008-1128, -1136 9
system of justice which has prevailed in our country. Such experts tend to become in 

the eyes of the jury anointed, not appointed.”). Furthermore, the Supreme Court has 

long recognized the constitutionality of court-appointed experts. See, e.g., Ex parte 

Peterson, 253 U.S. 300, 312-13 (1920). 

 The predicaments inherent in court appointment of an independent expert and 

revelations to the jury about the expert’s neutral status trouble this court to some extent. 

Courts and commentators alike have remarked that Rule 706 should be invoked only in 

rare and compelling circumstances. In re Joint E. & S. Dists. Asbestos Litig., 830 F. 

Supp. 686, 693 (E.D.N.Y. 1993) (noting that “use of Rule 706 should be reserved for 

exceptional cases in which the ordinary adversary process does not suffice”); Wright, 

supra, § 6302 (“Rule 706 powers are properly invoked where the issues are complex 

and the parties’ experts have presented conflicting testimony that is difficult to reconcile 

or have otherwise failed to provide a sufficient basis for deciding the issues.”). 

However, under Ninth Circuit law, district courts enjoy wide latitude to make these 

appointments. This court perceives no abuse of discretion in this case where the district 

court was confronted by what it viewed as an unusually complex case and what 

appeared to be starkly conflicting expert testimony. See, e.g., Walker, 180 F.3d at 1071 

(finding no abuse of discretion in Rule 706 appointment where the scientific evidence 

was “confusing and conflicting” and the appointment “assist[ed] the court in evaluating 

contradictory evidence about an elusive disease of unknown cause”). 

IV 

 The jury found all asserted claims of O2 Micro’s ’722 patent obvious under 35 

U.S.C. § 103. When reviewing a district court’s decision to deny JMOL as to 

2008-1128, -1136 10
obviousness, “this court reviews a jury’s conclusions on obviousness, a question of law, 

without deference, and the underlying findings of fact, whether explicit or implicit within 

the verdict, for substantial evidence.” LNP Eng’g Plastics, Inc. v. Miller Waste Mills, 

Inc., 275 F.3d 1347, 1353 (Fed. Cir. 2001). Such underlying factual questions include 

the scope and content of the prior art, the differences between the prior art and the 

claims at issue, and the level of ordinary skill in the art. Dippin’ Dots, Inc. v. Mosey, 476 

F.3d 1337, 1343 (Fed. Cir. 2007) (citing Graham v. John Deere Co., 383 U.S. 1, 17 

(1966)). On appeal, O2 Micro disputes the underlying factual findings implicit in the 

jury’s obviousness verdict. In particular, O2 Micro argues that substantial evidence 

does not support the jury’s finding that U.S. Patent No. 5,923,129 (the “Henry” patent) 

discloses various features of the ’722 patent’s claims. 

 The Henry patent carries the title, “Apparatus and Method for Starting a 

Fluorescent Lamp.” Like the ’722 patent, Henry teaches a power conversion circuit for 

driving a CCFL load. Henry patent col.2 ll.6-10. Like the feedback functionality of the 

’722 patent, Henry teaches a “feedback circuit which detects the total current passing 

through the CCFL . . . so that the controller may control the current passing through the 

CCFL.” Id. at col.2 ll.33-37. Further, like the ’722 patent’s full-bridge inverter, Henry 

discloses “generat[ing] two output signals to drive a pair of switching transistors 

connected to opposite terminals of the centertapped primary of a transformer.” Id. at 

col.2 ll.38-41. O2 Micro’s appeal disputes whether Henry teaches three specific 

elements of its asserted claims, namely, the “flow-through switch” of claims 2 and 9; the 

“second state” limitation of claims 1, 2, 9, and 18; and the “only if” limitation of claims 12 

and 14. 

2008-1128, -1136 11
A. The “Flow-through Switch” Limitation

Claims 2 and 9 require 

a flow-through switch coupled to said error amplifier and having first 

conduction state wherein the output of said switch comprises a DC signal 

indicative of said first state of said second pulse signal, and a second 

conduction state wherein the output of said switch comprises a DC signal 

indicative of said second state of said second pulse signal. 

’722 patent col.11 ll.33-39. The ’722 patent’s specification describes a “switch 38” for 

regulating current provided to the CCFL. Id. at col. 8 ll.7-33. The circuitry generates a 

comparison signal CMP, which reflects the difference between reference signal REF 

(desired current to flow through the lamp) and the feedback signal FB (indicating actual 

current flowing through the lamp). Id. at col.8 ll.4-6. When CMP is within a permitted 

range (normal operation), switch 38 permits CMP to “flow through,” delivering power to 

the load in proportion to the feedback signal. Id. at col.8 ll.17-22. However, when CMP 

is outside the permitted range (e.g., an open circuit or short circuit), switch 38 blocks 

CMP from flowing through to the load, instead supplying a minimal voltage “Vmin” until 

permissible current is once again flowing. Id. col.8 ll.22-31. In accordance with this 

disclosure, the district court defined a flow-through switch as “a switch which passes a 

selected voltage signal to its output mode.” Appellees relied exclusively on the Henry 

patent as showing the claimed flow-through switch in the prior art. 

Substantial evidence is “more than a mere scintilla” and is “such relevant 

evidence as a reasonable mind might accept as adequate to support a conclusion.” Z4 

Techs., Inc. v. Microsoft Corp., 507 F.3d 1340, 1353 (Fed. Cir. 2007). Substantial 

evidence supports the conclusion that the Henry patent teaches a flow-through switch. 

MPS’s expert, Dr. Horenstein, testified that “comparator 740” in Figure 8B of the Henry 

2008-1128, -1136 12
reference teaches a flow-through switch as claimed in the ’722 patent. Trial Tr. 

1200:13-19, May 9, 2007. Despite O2 Micro’s current assertions that Henry’s 

comparator 740 only outputs predetermined states, rather than passing through 

voltages, O2 Micro did not cross-examine Dr. Horenstein on his assertion as to this 

point, and O2 Micro’s own expert did not testify on this subject at all. Thus, the record 

stands unrebutted with evidence showing that Henry included a flow-through switch. 

O2 Micro’s attorney arguments on appeal cannot create an evidentiary gap. See

Johnston v. IVAC Corp., 885 F.2d 1574, 1581 (Fed. Cir. 1989) (noting that “Attorneys’ 

argument is no substitute for evidence.”). 

B. The “Second State” Limitation

Claims 1, 2, 9, and 18 require an inverter with a 

second pulse signal having a first state which overlaps said first pulse signal 

to deliver an amount of power to said load determined by said feedback 

signal, and a second state which overlaps the first signal with a 

predetermined minimum overlap to deliver a predetermined minimum power 

to the load. 

’722 patent col.11 ll.22-27 (emphasis added). The claimed “second state” relates 

closely to the function of the flow-through switch. When CMP is outside a permissible 

range, (e.g., during an overvoltage or open lamp condition), the disclosed circuitry 

enters into the second state–shutting off feedback control and instead supplying 

minimum power to the CCFL load until permissible current once again flows through the 

CCFL. Id. at col.8 ll.22-31. O2 Micro challenges, on substantial evidence grounds, 

whether the Henry patent discloses this second state. O2 Micro does not appear to 

challenge whether Henry has a non-feedback-controlled second state, but more 

2008-1128, -1136 13
specifically, whether Henry teaches a second state that delivers a predetermined 

minimum amount of power to the load. 

 MPS’s expert Dr. Horenstein testified that the “sawtooth generator” of the Henry 

patent teaches the claimed “second state.” The Henry patent itself states that this 

sawtooth generator produces a “reduced duty cycle . . . to prevent overvoltage and 

overheating of the transformer . . . .” Henry patent col.14 ll.37-39. Dr. Horenstein 

testified that during startup or fault conditions, Henry shuts off feedback and reverts to a 

“minimum power output state” produced by the sawtooth generator. Trial Tr. 1196:8-13, 

May 9, 2007. Horenstein further testified that when the Henry patent detects an 

overvoltage condition, “it grounds the input of the comp pin, which leads to the minimum 

possible pulse that the controller can produce.” Id. at 1196:3-5 (emphasis added). 

 O2 Micro’s expert Dr. Rhyne provided conflicting testimony. He testified that 

Henry’s second state outputs a minimal zero voltage only half the time: 

[The] sawtooth generator . . . does not disable under an open-lamp condition 

the operation of this inverter all the time. Instead, it does it only 50 percent of 

the time . . . It just says, ‘Hey, I don’t want to get too much voltage, so I am 

going to just turn this thing off, which would be very much like some of these 

claims require. But then the other half of the time it just turns it right back on. 

So it is not something that completely turns off the operation if you detect the 

open-lamp condition. It just sort of cripples it, but it allows it to run half of the 

time as it would otherwise. 

Id. at 1299:25-1300:13. 

Dr. Horenstein’s testimony provides substantial evidence for the jury to have 

found the “second state” limitation in the prior art. Indeed, Dr. Horenstein 

acknowledged and seems to have embraced Dr. Rhyne’s characterization of Henry’s 

sawtooth generator as consistent with the claimed second state: 

2008-1128, -1136 14
The sawtooth is used for part of the reaction of the system to the open 

lamp, but the output of that sawtooth generator is a logical signal, a one or 

a zero, a high or a low which sets the controller into a minimum output 

state. 

Id. at 1198:4-7. Thus, the jury was entitled to credit Dr. Horenstein’s testimony 

regarding Henry’s “reduced duty cycle” over Dr. Rhyne’s differing testimony. This court 

finds no reason to disturb that implicit factual finding. 

C. The “Only If” Limitation

Claims 12 and 14 of the ’722 patent require a feedback circuit which delivers 

power to the CCFL load “only if said feedback signal is above a predetermined 

threshold.” ’722 patent col.12 ll.49-50. Dr. Santi and Dr. Horenstein concurred that the 

Henry patent teaches this limitation because it teaches disengaging feedback and going 

into a fixed minimal voltage output state when the feedback signal drops below a 

predefined threshold. Trial Tr. 338 (May 1, 2007) (Santi); Trial Tr. 1202 (May 9, 2007) 

(Horenstein). The specification of the Henry patent corroborates their testimony by 

teaching that power is delivered to the CCFL only when the current feedback signal is 

above “VREF,” which is defined as a “stable reference voltage.” Henry patent col.13 ll. 

38-57, col.10 ll.48-51. Accordingly, substantial evidence supports a finding that Henry 

teaches the claimed “only if” limitation. 

 In sum, substantial evidence supports the factual underpinnings implicit in the 

jury’s verdict. This court “presume[s] that the jury resolved the underlying factual 

disputes in favor of the verdict winner and leave[s] those presumed findings undisturbed 

if they are supported by substantial evidence.” Jurgens v. McKasy, 927 F.2d 1552, 

1557 (Fed. Cir. 1991). However, O2 Micro argues that even if substantial evidence 

supports the finding that every element of the asserted claims was in the prior art, the 

2008-1128, -1136 15
verdict must fail as a matter of law because Drs. Santi and Horenstein articulated no 

reasons for combining the cited references. To the contrary, upon review of the entire 

record, this court finds convincing the testimony of Drs. Santi and Horenstein that one of 

ordinary skill in the art would have had ample motivation to combine known elements in 

the claimed manner. These experts opined that inverter circuit designers routinely mix 

and match bridge topologies, over-voltage safety protections, and feedback methods – 

all elements of the asserted claims and all conceded by O2 Micro to be well known in 

the art. For example, Dr. Horenstein testified that a skilled artisan would have been 

motivated to combine the full bridge inverter shown in Figure 2 of the Henry patent with 

the sawtooth generator in Henry’s Figure 8, which implements the claimed open lamp 

control because 

whether one implements this kind of open lamp control with a full bridge or 

a half-bridge is immaterial. The selection of the bridge is like picking a 

lego out of a lego box. You can implement the safety functions pertinent 

to open lamp with a full bridge, or a half bridge. And, in fact, this patent 

talks about doing it with both full bridge and half-bridge. So tying this 

controller to a full bridge is not a great leap of faith. 

Trial Tr. 1196:20-1197:2 (May 9, 2007). 

Section 103 of Title 35 requires this court to inquire “whether the improvement is 

more than the predictable use of prior-art elements according to their established 

functions.” KSR Int’l Co. v. Teleflex Inc., 127 S. Ct. 1727, 1740 (2007). Applying the 

law to the facts in the record, this court answers the inquiry in the negative and 

concludes that the asserted claims of the ’722 patent are obvious as a matter of law. 

IV 

 Because this court finds that the district court did not abuse its discretion in 

appointing Dr. Santi as an independent expert under Federal Rule of Evidence 706, and 

2008-1128, -1136 16
2008-1128, -1136 17

because this court affirms the district court’s denial of O2 Micro’s JMOL motion as to 

obviousness under § 103, this court need not reach the other issues raised by O2 

Micro’s appeal. Accordingly, this court affirms the judgment of the district court. 

AFFIRMED

NO COSTS