QSC Audio Products, LLCv.Crest Audio, Inc.

Patent Trial and Appeal Board

Apr 29, 2015

09151140 (P.T.A.B. Apr. 29, 2015)

Trials@uspto.gov Paper 43
571-272-7822 Entered: April 29, 2015

UNITED STATES PATENT AND TRADEMARK OFFICE
_____________

BEFORE THE PATENT TRIAL AND APPEAL BOARD
____________

QSC AUDIO PRODUCTS, LLC,
Petitioner,

v.

CREST AUDIO, INC.,
Patent Owner.
____________

Case IPR2014-00127
Patent 6,023,153
____________

Before MIRIAM L. QUINN, GLENN J. PERRY, and BRYAN F. MOORE,
Administrative Patent Judges.

PERRY, Administrative Patent Judge.

FINAL WRITTEN DECISION
Inter partes review
35 U.S.C. § 318(a) and 37 C.F.R. § 42.73

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I. INTRODUCTION
Petitioner, QSC Audio Products, LLC (“QSC” or “Petitioner”), filed a
Petition (Paper 3, “Pet.”) to institute an inter partes review of claims 1–22
(all claims) of U.S. Patent No. 6,023,153 (Ex. 1001, “the ’153 patent”)
pursuant to 35 U.S.C. §§ 311–319. Petitioner indicates that the ’153 patent
is being asserted in Crest Audio, Inc. v. QSC Audio Products, LLC, 3:12-cv-
755-FKB, filed in the United States District Court for the Southern District
of Mississippi, Jackson Division, on November 7, 2012.
On May 2, 2014 we granted the Petition as to claims 1–22 of the
’153 patent and instituted trial on two grounds of unpatentability as set forth
below. Paper 12, “Dec. on Inst.”

Claims Grounds Reference
Claims 1–22 § 103 APA1 and Hancock2
Claims 1–22 § 103 APA and Gordon3

Patent Owner, Crest Audio, Inc. (“Crest” or “Patent Owner”) argues
in the Response that Hancock and Gordon are not published references

1 The Admitted Prior Art (“APA”) includes ’153 patent Figures 1 and 2,
along with corresponding description. It also includes subject matter
incorporated by reference into the ’153 patent including the subject matter of
U.S. Patent Nos.: 5,461,303 (“the ’303 patent”) issued January 31, 1994;
5,502,630 (“the ’630 patent”) issued July 19, 1994; 5,614,810 (“the ’810
patent”) issued February 14, 1994; and 5,637,988 (“the ’988 patent”) issued
June 7, 1995.
2 Jon Hancock, A Class D Amplifier Using MOSFETs with Reduced
Minority Carrier Lifetime, Audio Engineering Society Preprint 2958 (E-5),
1990 (Exhibit 1002, “Hancock”).
3 Jay Gordon, The Characteristics of Conventional and Switching
Power Supplies in Analog Signal Processing, Audio Engineering Society
Preprint 3889 (G-5), 1994 (Exhibit 1003, “Gordon”).
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(Paper 21, “Resp.”), and filed a Motion to Exclude (Paper 34, “Motion” or
“Mot.”), seeking to exclude them as evidence. Patent Owner did not make
any substantive arguments regarding the subject matter alleged to be taught
by Hancock or Gordon. Nor did it challenge Petitioner’s characterization of
the APA. See Resp. Petitioner replied (Paper 25, “Reply”) to Patent
Owner’s Response, and opposed (Paper 37, “Opposition”) Patent Owner’s
Motion to Exclude. Oral Argument was held on January 27, 2015. Paper
42, “Tr.”
The Board has jurisdiction under 35 U.S.C. § 6(c). In this Final
Written Decision, issued pursuant to 35 U.S.C. § 318(a) and 37 C.F.R.
§ 42.73, we determine Petitioner has demonstrated by a preponderance of
the evidence that all claims for which trial was instituted, claims 1–22, are
unpatentable.
II. THE ’153 PATENT (Ex. 1001)
Figures 1 and 2 of the ’153 patent are labeled “PRIOR ART.” Figure
1 is reproduced below.
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Figure 1 is a schematic diagram showing an audio amplifier circuit
employing a linear power supply. Ex. 1001, 3:15–17. The
“BACKGROUND OF THE INVENTION” portion of the ’153 patent
explains that an audio amplifier, such as shown in Figure 1, has design and
operational disadvantages. AC line transformer 14 is typically very large
and heavy due to the relatively low frequency of the AC line. Filter
capacitor 18 must have a relatively high value of capacitance, possibly
requiring multiple capacitors. Ex. 1001, 1:33–39. An operational
disadvantage is illustrated by Figure 5 of the ’153 patent, reproduced below.
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Figure 5 of the ’153 patent is a graphical representation of a relationship
between line voltage and input current waveforms. When using a
conventional switching power supply, the waveform (spiked waveform
referenced “I”) of current drawn from the power supply does not match the
waveform (sine waveform referenced “AC LINE VOLTAGE”) of the input
line voltage. This waveform mismatch causes harmonics to be generated,
which result in distortion and noise. Id. at 1:40–50.
Also according to the “BACKGROUND OF THE INVENTION,”
audio amplifiers were known to use a switching-type power supply 11, as
shown in Figure 2 of the ’153 patent, reproduced below. Id. at 1:63–65.
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Figure 2 of the ’153 patent is a schematic diagram of a prior art audio
amplifier circuit employing a switching power supply according to the prior
art. Id. at 3:19–21.
The improvement taught by the ’153 patent is to add power factor
correction circuit 30 to the power supply as shown at the left side of Figure 4
of the ’153 patent, reproduced below. Ex. 1001, 3:37–41.

Figure 4 of the ’153 patent is a schematic diagram of the claimed
audio amplifier circuit including power factor correction. Ex. 1001, 3:25–
27. According to the ’153 patent, power factor correction circuits including
“boost” configurations were known, but not used in audio amplifiers. Id. at
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2:11–21, 3:42–61. Rather than explain in detail what was well-known at the
writing of the ’153 patent, the ’153 patent incorporated by reference the
disclosures of four U.S. patents describing power factor correction circuits,
including their circuit configurations and how to operate them:
It is understood that the switch 32 and inductor 34 are
arranged in a boost configuration and that the power factor
correction circuit 30 operates in a manner well known in
the art for providing power factor correction of an AC line.
See for example, U.S. Pat. Nos.: 5,461,303, 5,502,630,
5,614,810, and 5,637,988, the entire disclosures of which
are hereby incorporated by reference.
Ex. 1001, 3:55–61.
During prosecution of the application resulting in the ’153 patent,
Applicant argued that the cited references, although teaching power factor
correction, did not provide any “motivation” to combine such circuits with
an audio amplifier. Ex. 1006, 55. The ’153 patent issued, at least in part, as
a result of these statements.
Independent claims 1 and 9, reproduced below, are illustrative of the
claimed subject matter.
1. An audio amplifier for receiving input current
and sinusoidal line voltage from an AC source, and
delivering audio output power to a load, the audio
amplifier comprising:

a power factor correction circuit for receiving the
line voltage from the AC source, the power factor
correction circuit including a control circuit
operable to cause the wave shape of the input
current drawn from the AC source to substantially
correspond to the wave shape of the line voltage
by producing an intermediate source of voltage at a
substantially higher potential than the line voltage
of the AC source;
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a DC power supply coupled to the power factor
correction circuit and operable to convert the
intermediate source of voltage into a regulated DC
source of power; and

an audio power amplifier coupled to the DC power
supply and operable to convert the DC source of
power into the audio output power for delivery to
the load.

9. An audio amplifier for receiving input current
and sinusoidal line voltage from an AC source, and
delivering audio output power to a load, the audio
amplifier comprising:

a power factor correction circuit for receiving the
line voltage from the AC source and controlling
the phase of the input current drawn from the AC
source to substantially correspond to the phase of
the line voltage, the power factor correction circuit
producing an intermediate source of voltage;

a DC power supply coupled to the power factor
correction circuit and operable to convert the
intermediate source of voltage into a regulated DC
source of power; and

an audio power amplifier coupled to the DC power
supply and operable to convert the DC source of
power into the audio output power for delivery to
the load.

Each of independent claims 1 and 9 is directed to a combination
including a power factor correction circuit, a DC power supply, and an audio
amplifier. They use slightly different language to characterize the use of
power factor correction. Claim 1 characterizes the power factor correction
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circuit as causing the “wave shape” of the input current drawn from the AC
source substantially to correspond to the “wave shape” of the line voltage by
producing an intermediate source of voltage at a substantially higher
potential than the line voltage of the AC source. Claim 9 characterizes the
power factor correction circuit as matching the “phase” of the input current
to the line voltage.
III. MOTION TO EXCLUDE
Patent Owner argued in its Response (Paper 21) and in its Motion to
Exclude that Hancock and Gordon are not “printed publications” under the
patent law, and that they should be excluded from evidence. The Motion
also asks that we exclude paragraphs 11 and 19 of the Santi Declaration (Ex.
1004) and portions of the Cordell Deposition (Ex. 1008).
A. Critical Date
The ’153 patent issued from application 09/151,140 filed on
September 10, 1998. The application identifies related U.S. Provisional
Application 60/059,591 filed on September 23, 1997, the critical date.
Ex. 1001, filed code elements [21], [22], [60]. Therefore, to be considered
“prior art,” the asserted references must have an effective date that predates
the critical date of September 23, 1997.
B. Authentication
Patent Owner argues that Fed. R. Evid. 9014 and 9025 prevent our
consideration of Hancock and Gordon because they are not authenticated as
“publications” under the patent law. Mot. 1. Authenticating rules are

4 Authenticating or Identifying Evidence.
5 Evidence that is Self-Authenticating.
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intended to ensure that documents are what they purport to be. Fed. R. Evid.
901(a). One example of evidence that satisfies the authentication
requirement is stated in Fed. R. Evid. 901(b)(4): “[t]he appearance,
contents, substance, internal patterns, or other distinctive characteristic of
the item, taken together with all the circumstances.”
The cover pages of Hancock and Gordon bear similar identifying
markings and qualifiers. As an example, we consider the Hancock cover
page, reproduced below. Ex. 1002, 1.

The cover page: 1) bears two distinctive logos of the Audio Engineering
Society (AES); 2) states that the document is a “preprint” produced from an
author’s advance manuscript; 3) states a unique number assigned to the
preprint; 4) identifies a particular session of an AES Convention at which it
was “presented;” 5) bears dates of the AES Convention at which the paper
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was presented; and 6) states how additional preprints may be obtained. See
also Ex. 1003, 1(cover page of Gordon depicting the same information).
With regard to the dates of the relevant AES Conventions, according
to Hancock’s cover page, the 89th AES Convention took place from
September 21–25, 1990. Ex. 1002, 1. And according to Gordon’s cover
page, the 97th AES Convention took place from November 10–13, 1994. Ex.
1003, 1.
Petitioner provides declaration testimony of Jessica King (Ex. 2002,
“King Declaration”), librarian at the law firm of Petitioner’s Counsel,
demonstrating that one can purchase and download copies of AES papers
from the “AES E-Library” website. King Declaration, 2. Jessica King
testifies that she purchased and downloaded copies of Hancock and Gordon
from that website. Id. at 2–3. She further testifies that “search results” show
that AES indicates publication dates for Hancock and Gordon as being
September 1, 1990, and November 1, 1994, respectively. Id. at 2–3.
Patent Owner argues that these search results do not authenticate
Hancock and Gordon because they are inadmissible hearsay under Fed. R.
Evid. 802. Mot. 3. According to Patent Owner, a “preprint” is not “self-
authenticating” as a publication under Rule 902, and, therefore, Petitioner
must produce evidence sufficient to support a finding that a “preprint” is,
indeed, a “printed publication.” Id. at 2.
Petitioner disagrees and argues that to authenticate each of Hancock
and Gordon Petitioner simply “must produce evidence sufficient to support a
finding that the item is what the [Petitioner] claims it is.” Paper 37, 1 (citing
Fed. R. Evid. 901(a)). In support of this position, Petitioner points to the
layout, AES logo, and boilerplate language on the front pages of Hancock
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and Gordon to authenticate these exhibits under Rule 901(b)(4). Paper 37, 2–
4. Furthermore, the various indicia on the Hancock and Gordon cover pages
match the indicia found on the Cordell paper (Ex. 1009) presented at the 72nd
AES Convention, as testified to by Patent Owner’s expert. See Ex. 1009, 1.
Patent Owner’s arguments conflate two separate issues — 1) whether
Hancock and Gordon are authentic, and 2) whether they constitute
publications under the patent law. Hancock and Gordon include the AES
logo and their respective layouts are the same. The cover pages further
identify a specific address for AES for the purpose of obtaining additional
preprints, and state that reproduction of the articles is prohibited without
permission from the Journal of the Audio Engineering Society. Exs. 1002
and 1003. There is no dispute that these documents are preprints of papers
intended for presentation at their respective AES conventions. Therefore,
having considered and weighed the distinctive characteristics of the articles
and the circumstances surrounding their retrieval from the AES E-Library,
we find that Hancock and Gordon are what they appear to be—papers
categorized by the Audio Engineering Society as “preprints.” Petitioner has
met its authentication burden under Fed. R. Evid. 901 and 902. Whether the
self-authenticated “preprints” qualify as “publications” under the patent law
is a separate matter.
C. Hearsay
Because the only grounds of unpatentability a petitioner may raise in
an inter partes review are those based on prior art consisting of patents or
printed publications (35 U.S.C. § 311(b)), we must determine whether
Hancock and Gordon were published before September 23, 1997, the critical
date. To prove the publication date of Hancock and Gordon, Petitioner
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relies on the information printed on the cover page of each of the preprints,
namely that they were “presented” at AES conventions in 1990 (Hancock)
and 1994 (Gordon). See Pet. 4.
Patent Owner argues that Hancock and Gordon should be excluded
because the statements of dates on the respective cover pages, e.g.,
“presented at the 97th Convention 1994 November 10-13” on the cover of
Gordon, are hearsay evidence attempting to establish a date of publication.
Mot. 4–6 (citing Fed. R. Evid. 802).
Petitioner argues that Patent Owner’s challenges under Fed. R. Evid.
802 fail because the statements are not hearsay—Hancock and Gordon have
been authenticated as “conference papers that were published as of the dates
shown on the cover[ pages, and] Petitioner is not relying on the statements
that appear on the face of the [ ] papers for the truth of the matter asserted.”
Opposition 7. Alternatively, Petitioner argues that, even if the statements
were hearsay, they would come within the ancient documents (Fed. R. Evid.
803(16)) or the residual hearsay (Fed. R. Evid. 807) exceptions to the
hearsay rule.6 Id. at 911.
We are not persuaded by Petitioner’s argument that the statements are
not hearsay. Although Hancock and Gordon have been authenticated as
preprints maintained by AES, Petitioner relies on the truth of the matter
asserted on the face of the preprints, i.e., that they were presented at the AES
convention on the date stated on the cover page. Without these statements,
there is no evidence that each of Hancock and Gordon were actually
available, as printed publications, at those conventions or on any other
particular date. We note that Patent Owner does not argue that these

6 As of the date of this decision, both documents are more than 20 years old.
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documents were not associated with their respective AES conventions. The
question for us to decide is whether Petitioner has provided sufficient
evidence and argument showing that the statements relied on are admissible
under an exception to the hearsay rule. We find that, in this situation, the
statements should not be excluded as hearsay, because they come within two
separate exceptions to the hearsay rule.
At least the Hancock preprint qualifies as an ancient document subject
to Fed. R. Evid. 803 (C)(16), which applies to documents to be at least 20
years old whose authenticity is established. Per our discussion above,
Hancock and Gordon are authenticated. The Hancock preprint purports to
have been presented September 21,25, 1990, more than 20 years ago. Ex.
1002, 1. The Gordon preprint purports to have been presented November
10-13, 1994, more than 20 years ago from the time of this decision (but not
more than 20 years ago from the time of the Decision to Institute). Ex.
1003, 1.
Both the Hancock and Gordon preprints also meet the circumstances
outlined in Fed. R. Evid. 807, the residual exception to hearsay. To qualify
for the residual exception under Fed. R. Evid. 807, four requirements must
be met: 1) the statement has equivalent circumstantial guarantees of
trustworthiness; 2) it is offered as evidence of a material fact; 3) it is more
probative on the point for which it is offered than any other evidence that the
proponent can obtain through reasonable efforts; and 4) admitting will best
serve the purposes of these rules and the interests of justice. Fed. R. Evid.
807.
Petitioner argues persuasively that the four requirements are met.
Opposition, 1011. For example, Petitioner argues circumstantial
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guarantees of trustworthiness by virtue of all the indicia on the cover pages
of the documents showing it is a genuine preprint of the AES obtained from
the organization’s repository of similarly categorized preprints. Id.
Petitioner also argues that the statements are evidence of a material fact:
convention dates set forth on the preprints. Id. Furthermore, Petitioner
argues that the dates on the cover pages are more probative than other
documents Petitioner has obtained through reasonable efforts. Id. (pointing
to the website listing of alleged publication dates that Patent Owner has
challenged as inadmissible hearsay). Finally, Petitioner argues, and we
agree, that admitting the statements as evidence of the date of publication
serve the interest of justice. Id. Although we recognize that Petitioner had
other avenues of proving these statements were not hearsay, such as by
obtaining evidence from AES regarding the custody of its electronic
documents, our concern with ensuring trustworthiness and accuracy of
documents admitted in evidence has been alleviated. For example,
Petitioner has provided AES website documents (also self-authenticated)
that corroborate similar dates as those stated on the cover page of the
references. Furthermore, the dates of the documents cited within the
references are all before the date of the stated presentation of the documents.
Yet another fact we consider is that the cover pages of all the AES preprints
submitted into evidence have similar characteristic layouts (format), the
same information, and sufficient detail regarding the AES convention and
the manner in which the preprints may be obtained. See also Ex. 1008,
90:1892:10 (Mr. Cordell testifying that his own article was sold and
distributed by AES at the AES convention at which he presented the paper).
Based on the foregoing, and after a careful review of the proffered
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evidence and arguments, we find that the statements on the cover page of
Hancock and Gordon regarding presentation of the preprint at the particular
AES convention are admissible.
D. Declaration Testimony of Enrico Santi, Ph.D. (Ex. 1004)
Petitioner presented the declaration testimony of Enrico Santi, Ph.D.
(Ex. 1004) regarding Hancock and Gordon. Paragraphs 11 and 19 of the
Santi Declaration state that Hancock and Gordon were presented to the AES
Society at the 89th and 97th Conventions, respectively. Ex. 1004 ¶¶ 11, 19.
Patent Owner took the deposition of Dr. Santi and notes that he explained
during that deposition that an AES “preprint” is not the same as an AES
journal publication. Resp. 3–4. In particular, a “preprint” has not undergone
peer review. Ex. 1001 pp 104-105.
Patent Owner asks that we exclude paragraphs 11 and 19 of the Santi
Declaration (Exhibit 1004) under Fed. R. Evid. 602 and 401–402. Mot. 6.
Patent Owner argues that Dr. Santi lacks personal knowledge to provide any
insight as to whether Hancock or Gordon were presented at all, much less on
the dates he contends that they were presented in paragraphs 11 and 19 of
Exhibit 1004. Therefore, according to Patent Owner, these paragraphs
should be excluded under Fed. R. Evid. 602, which states that a witness may
not testify to a matter unless evidence is introduced sufficient to support a
finding that the witness has personal knowledge of the matter.
Petitioner argues that Patent Owner’s challenge to paragraphs 11 and
19 of Dr. Santi’s declaration (Ex. 1004) fails because Rule 703 permits an
expert witness to rely on dates printed on documents on which the expert
opines. Paper 37, 11–12.
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We agree with Petitioner that experts regularly rely on printed
documents, notwithstanding their admissibility. However, we understand
that Dr. Santi did not personally attend the conventions at which the
Hancock and Gordon papers are purported to have been presented. We,
therefore, take no further meaning from paragraphs 11 and 19 than Dr. Santi
observed the same text on the cover sheets that we observe — that these
documents are “preprints” purported to have been presented at convention
session numbers stated on their respective cover sheets. We do not take
these paragraphs as evidence that Dr. Santi observed their presentation or
otherwise knows that presentations were carried out as described on the
cover sheets. The panel draws its own conclusions from the totality of the
evidence.
E. Deposition of Robert Cordell (Ex. 1008)
Robert Cordell is Patent Owner’s expert declarant in related inter
partes reviews IPR2014-00129 and IPR2014-00131. Petitioner relies upon
the deposition of Robert Cordell (Ex. 1008) as establishing the customary
practice of the AES at its conventions regarding “preprints.”
Mr. Cordell testifies that he joined the AES in 1973 or 1974 and then
attended 30–40% of its conventions which were held two or three times per
year. Ex. 1008,18. Mr. Cordell, like Hancock and Gordon, made
presentations at various AES conventions. Id. at 2. According to Mr.
Cordell, his own “talks”7 were preceded by the AES making available
“preprints” (for a fee) to convention participants before they entered the
convention session for the talk. Id. at 4–12. According to Mr. Cordell,

7 One of Mr. Cordell’s papers was made of record as Exhibit 1009. It bears
markings on its cover sheet similar to those found on Hancock and Gordon.
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preprints were usually made available. Id. at 19.
Petitioner argues that the Cordell testimony supports Petitioner’s
argument that it was the custom and practice of the AES to make available
to convention participants preprints of papers being presented at the
convention. Reply 10.
Patent Owner argues that Cordell’s testimony that some preprints
were made available does not establish that all preprints were made
available. Mot. 8. Patent Owner further argues that although Cordell
testifies that he attended some AES conventions where preprints were made
available, there is no evidence in the record that he attended the particular
conventions at which the Gordon and Hancock papers were presented.
Patent Owner also argues that the Cordell testimony is irrelevant (Rule 401)
to the issue of whether Hancock and Gordon were actually disseminated or
otherwise made available on the dates Petitioner claims they were available.
Id.
Petitioner argues that Patent Owner’s challenge to its own expert’s
sworn testimony (Ex. 1008) fails because it relies on a rule that is not
applicable and because the basis for Patent Owner’s challenge goes to the
weight and not to the admissibility of Mr. Cordell’s testimony. Opposition
1. Petitioner further argues that Patent Owner’s challenge under Rule 401 is
misplaced. We agree with Petitioner.
The testimony of Mr. Cordell is relevant. Although Mr. Cordell
attended AES conventions other than the 89th (Hancock) and 97th (Gordon)
conventions, his experience as stated in his deposition is relevant and
probative of the business practices of the AES. Cordell testified that he
attended a number of AES conventions and that preprints were usually made
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available via an “on-site bookstore” that sold preprints of papers scheduled
for presentation. For example, Cordell testified that at the 72nd convention,
the AES had a counter at which preprints could be purchased. Mr. Cordell
testified that he attended 30–40% of the AES conventions since he became a
member in 1973 or 1974 including the 64th and 70th AES conventions, and
that the AES gave him free copies of preprints of his own papers so that he
could distribute them to friends. Ex. 1008, 96:18–97:23 Thus, the Cordell
testimony provides relevant information probative of the business practices
of AES with regard to the dissemination of preprints at AES conventions.
Patent Owner argues that even if not irrelevant under Rule 401, the
Cordell testimony, probative of the AES business practices, is outweighed
by being confusing, vague, and speculative. We disagree. This is not a jury
trial. The panel is not confused by the testimony and is in a position to
appropriately weigh Mr. Cordell’s testimony along with the other evidence
of record. The Board, sitting as a non-jury tribunal with administrative
expertise, is well-positioned to determine and assign appropriate weight to
evidence presented. Gnosis S.P.A. v. S. Alabama Medical Science
Foundation, Case IPR2013-00118, slip op. at 43 (PTAB June 20, 2014)
(Paper 64). See also Donnelly Garment Co. v. NLRB, 123 F.2d 215, 224
(8th Cir. 1941) (“One who is capable of ruling accurately upon the
admissibility of evidence is equally capable of sifting it accurately after it
has been received.”).
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F. Conclusion
For reasons stated above, Patent Owner’s Motion to Exclude is
denied.
IV. ANALYSIS OF CLAIM CHALLENGES
A. Hancock and Gordon are publications
Patent Owner argues that Hancock and Gordon are not “publications”
within the meaning of the patent law. The touchstone of whether a
particular document is a publication under the patent law is whether it was
available to those of ordinary skill in the art to which it pertains.
The evidence, including the Cordell deposition testimony, strongly
suggests that it is the custom and practice of the AES to prepare and
distribute preprints of its convention presentations at a facility at the
convention.
The evidence further suggests that the AES makes available for
purchase, via its library website, copies of convention presentations after
they have been presented so that all interested persons may obtain copies of
documents presented at its conventions.
We conclude from the totality of evidence that the Hancock and
Gordon preprints were made available to attendees of their respective AES
Conventions. We further conclude that the Hancock and Gordon AES
conventions took place prior to the critical date. Thus, the preprints were
accessible to those of ordinary skill as of their respective convention dates,
well before the critical date. We, therefore, conclude that Hancock and
Gordon are publications within the meaning of the patent law.
We note that Patent Owner challenged the sufficiency of the evidence
presented by Petitioner, but did not offer any evidence that Hancock and
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Gordon are not publications. Based on the evidence and arguments
presented on the record before us, we conclude that Petitioner has shown by
a preponderance of the evidence that Hancock and Gordon are publications
within the meaning of the patent law.
B. Independent Claims 1 and 9
Our substantive inquiry focuses on whether the record before us
presents sufficient evidence that, at the time of the ’153 patent invention, it
would have been obvious to a person of ordinary skill in the relevant art to
use a known power factor correction circuit in combination with a known
switching power supply in an audio amplifier. The preponderance of the
evidence presented leads us to that conclusion.
Neither Hancock nor Gordon were before the Examiner during
prosecution of the ’153 patent. We are persuaded that both these references
provide sufficient rationale for using power factor correction in an audio
amplifier having a switching power supply. Pet. 13–16. In fact, both are
technical papers presented at respective conferences directed to audio
engineers and describe audio amplifiers. Pet. 13, 40. Further, because both
address the problem of distortion caused by waveform mismatch, and teach
the solution of providing power factor correction in the context of an audio
amplifier, these papers are evidence that a person of ordinary skill in the art
would have been motivated to apply a power factor correction solution to the
audio amplifiers known in the art at the time of the invention, and as
disclosed in the Background of the Invention of the ’153 patent.
For example, Hancock states that “[a]s for all buck converters, input
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current ripple is fairly high, and has a high harmonic content.” Ex. 1002, 2.8
Hancock’s Figures 27 and 28 (Id. at 17) are reproduced below.

Hancock Figure 27 shows a
mismatch of voltage and current
waveforms.
Hancock Figure 28
demonstrates a match in wave shape
and phase achieved by the addition of
a power factor correction circuit.

An example of voltage and current mismatch is shown in Hancock’s
Figure 27. Ex. 1002, 2 Hancock further recognizes the mismatch in a
section titled “Power Factor – the problem with capacitor input power
supplies.” Id. at 6. In that section, Hancock states that “power factor has
long been a concern and specified parameter.” Id. at 7. The Hancock
solution is to provide a “pre-regulator” (power factor correction) which
aligns the voltage and current waveforms in shape and phase. Id.
Gordon’s Figure 4 reproduced below, also demonstrates the problem
of mismatch between the input voltage and drawn current waveforms.

8 For exhibits, we refer to page numbers of the Exhibit, not to page numbers
of any separately numbered pages within the exhibit.
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Gordon’s Figure 4 is a graphical representation of power supply
voltage and current in an audio amplifier. Ex. 1003, 20. Given the admitted
prior art and the description in both Gordon and Hancock of the use of
power factor correction in an audio amplifier, the preponderance of evidence
establishes that claims 1 and 9 would have been obvious as of the critical
date based on the combination of either APA and Hancock or APA and
Gordon.
C. Claims 2 and 16
Claims 2 and 16 depend respectively from claims 1 and 9, and recite
structure and operation of the power factor correction circuit. Specifically,
these claims require the power factor circuit to include a boost circuit having
an inductor and a switching transistor. The switching transistor must have a
controlled duty cycle that is substantially greater than the frequency of the
AC source, and must produce an intermediate voltage having peaks that are
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substantially higher than the peak voltages of the AC source. See claims 2
and 16.
The ’153 patent specification admits that boost power factor
correction circuits and their operation were well-known. Ex. 1001, 3:55–61.
According to Petitioner’s declarant, Dr. Santi, claims 2 and 16 recite features
of a well-known power factor correction circuit. Ex. 1004 ¶¶ 73–74, 76.
Hancock describes a boost converter power factor correction circuit
that includes a switching transistor and an inductor. Ex. 1002, 6. “Typically
a boost or flyback converter is used as a pre-regulator to charge a 360 V
bus.” Id.; see Ex. 1004 ¶ 74. Hancock’s Figure 28 shows that the power
factor correction circuit biases the transistor on and off at a rate that is
substantially greater than the frequency of the AC source. Ex. 1004 ¶ 74.
Hancock indicates that the intermediate source of voltage has peak voltages
(360 Volts) that are substantially higher than peak voltages of the AC source
(90–260 VAC). Ex. 1002, 6.
Based on the foregoing, we are persuaded that Hancock discloses the
limitations recited in claims 2 and 16. We are further persuaded that Gordon
also teaches these limitations. For example, Gordon describes buck and
boost power supply configurations beginning at page 9 of Exhibit 1003.
In view of the above, the preponderance of evidence establishes that
claims 2 and 16 would have been obvious as of the critical date based on
either the APA when considered with Hancock or the APA when considered
with Gordon.

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D. Claims 3 and 17
Claims 3 and 17 require that the boost power factor correction circuit
be switched at a frequency of about 70 KHz.
Patent Owner admits in the specification that the use of a 70kHz
switching frequency was known. Ex. 1001, 2:16–18. This admission is
echoed by Petitioner’s declarant. Ex. 1004 ¶¶ 78–80. We also note that the
’153 patent incorporates by reference the ’303 patent in asserting that
operation of the power factor correction circuit was well-known in the art.
Ex. 1001, 3:55–61. We note that the incorporated subject matter includes
description of a useful frequency range of 48–500 kHz for a power factor
correction circuit. ’303 patent, 3:60. Ex. 3001.
Based on the evidence and the record before us, we conclude that
Petitioner has established by a preponderance of evidence that claims 3 and
17 would have been obvious based on either APA and Hancock or APA and
Gordon.
E. Claims 4, 8, 18, and 22
Claims 4, 8, 18, and 22 each require an intermediate voltage range
(boosted voltage produced by the power factor correction circuit) of 400–
500 volts. We are persuaded by Petitioner’s evidence that one of ordinary
skill in the art would have considered the use of an intermediate voltage of
“about 400–500 volts.” Pet. 2829, 3132, 38, 39.
Neither Hancock nor Gordon explicitly states the claimed range. Both
Hancock and Gordon, however, describe intermediate voltages that are
substantially higher than the input voltage. Gordon describes an
embodiment providing an intermediate voltage of 382 volts. Hancock
describes an embodiment providing an intermediate voltage of 360 volts.
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We have reviewed the ’153 patent and find that the range of about
400–500 volts is stated without any explanation as to why it might be
critical. The only explanation about the intermediate voltage is that it be
substantially higher than the input voltage in order for the power factor
correction circuit to provide the desired benefit. Ex. 1001, 3:1–3. No data
or explanation specific to the range of about 400–500 volts is provided.
One of ordinary skill in the art would have considered the specific
intermediate voltage to be a result-effective variable that can be optimized.
In re Antonie, 559 F.2d 618, 620 (CCPA 1977) (holding that a determination
that the discovery of optimum values of a variable in a known process would
have been within the level of ordinary skill in the art must be supported by a
showing that the variable is result-effective); see also In re Geisler, 116 F.3d
1465, 1470 (Fed. Cir. 1997) (“‘[I]t is not inventive to discover the optimum
or workable ranges by routine experimentation.’ Only if the ‘results of
optimizing a variable’ are ‘unexpectedly good’ can a patent be obtained for
the claimed critical range.” (internal citations omitted)). Patent Owner has
not demonstrated that the results are unexpectedly good at 400–500 volts.”
We find that the voltages described by Gordon and Hancock are
encompassed by the claimed range as both 382 and 360 volts are rounded to
“about” 400 volts, the lower voltage in the claimed range. We also are not
persuaded as to the patentable distinction based on the claimed voltage
range, and, therefore, find that the claimed intermediate range of about
400500 volts would have been obvious to a person of ordinary skill in the
art in view of the disclosed voltages in Gordon and Hancock.
Based on the evidence and the record before us, we are persuaded that
Petitioner has established by a preponderance of evidence that claims 4, 8,
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18, and 22 would have been obvious as of the critical date based on the
combination of either APA and Hancock or APA and Gordon.
F. Claims 5 and 19
Claims 5 and 19 are similar and depend respectively from claims 1
and 9. Illustrative claim 5 reads as follows:
The audio amplifier of claim 1, wherein the
power factor correction circuit or the DC power
supply includes a rectifier and a storage capacitor
coupled to the intermediate source of voltage such
that a preliminary DC source of power is available
across the storage capacitor, the DC power supply
converting the preliminary source of DC power
into the regulated DC source of power.

Figure 2 of the ’153 patent, reproduced above, shows an embodiment
of a DC power supply (without power factor correction). The Figure 2
(APA) embodiment includes rectifier 13 and storage capacitor 17 within DC
switching power supply 11, albeit not connected to an intermediate voltage
(no power factor correction is shown). The ’153 patent specification admits
that the switching power supply operates in a well-known manner. Ex.
1001, 1:63–2:10. The ’303 patent, incorporated into the ’153 patent
specification, shows a power factor correction circuit in its Figure 1 that
includes rectifier 16 and capacitor 18 providing an intermediate voltage to a
load 32. Figure 7 of the ’630 patent, also incorporated by reference into the
‘153 patent specification, shows a power factor correction circuit including
plurality of diode rectifiers CR20–28 and capacitor C2 providing an
intermediate voltage at terminal T3.
Petitioner’s declarant, Dr. Santi, testifies that a power factor
correction circuit or a switching power supply that includes a rectifier and a
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capacitor is well-known in the art. See Ex. 1004 ¶¶ 85–86.
Furthermore, Gordon describes a boost circuit known to have a
rectifier diode and storage capacitor. Ex. 1003, 10–11, Figs. 16–17.
The Hancock boost circuit (referred to as a “pre-regulator”) also has a
rectifier and a storage capacitor. Ex. 1002, 6.
Based on the evidence and the record before us, we conclude that
Petitioner has established by a preponderance of evidence that claims 5 and
19 would have been obvious as of the critical date based on the combination
of either APA and Hancock or APA and Gordon.
G. Claims 6 and 20
Claims 6 and 20 both require that the power supply be a switching
power supply. The ’153 patent specification admits that switching power
supplies were known at the time of invention. For example, the APA Figure
2 shows switching power supply 11. See Ex. 1004 ¶ 88. Furthermore,
Hancock discloses the use of a switching power supply. See id.; Ex. 1002, 6.
According to Petitioner’s declarant, the use of a switching power supply was
well known in the art. Ex. 1004 ¶¶ 88–89. This is confirmed by the
specification of the ’153 patent, which admits that the details of a “switching
power supply . . . are known in the art.” Ex. 1001, 3:42–44. We are
persuaded by Petitioner’s evidence that it would have been obvious for a
person of ordinary skill in the art to use a switching power supply for the DC
power supply, because switching power supplies were well known for use in
audio amplifiers. See Ex. 1004 ¶¶ 88–89.
With respect to Gordon, we also are persuaded that it discloses the use
of a switching power supply. Id.; Ex. 1003, 6.
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Based on the evidence and the record before us, we find that
Petitioner has established by a preponderance of evidence that claims 6 and
20 would have been obvious as of the critical date based on the combination
of either APA and Hancock or APA and Gordon.
H. Claims 7 and 21
Claims 7 and 21 require that the power supply be a resonant power
supply. We note that the ’153 patent specification admits that resonant
power supplies were known at the time of the invention: “It is preferred that
the switching power supply 11 be a resonant switching power supply, the
details of which are known in the art.” Ex. 1001, 3:41–43. Thus, claims 7
and 21 are directed to known features.
Hancock also discloses use of a resonant switching power supply:
“Fig. 29 shows the basic power switch circuit for one type of quasi-resonant
power supply . . . .” Ex. 1002, 6. Hancock points out that “[a]lmost any
kind of PWM supply may be built as an equivalent resonant circuit.” Id.
According to Petitioner’s declarant, the APA discloses the use of a
resonant switching power supply. Ex. 1004 ¶¶ 91–93. We are persuaded by
Petitioner’s evidence that it would have been obvious for a person of
ordinary skill in the art to use a resonant switching power supply for the DC
power supply, because resonant switching power supplies were well known
for use in audio amplifiers. See id. ¶¶ 92–93.
Given that the APA describes a resonant power supply, and that both
Hancock and Gordon combine a conventional power supply with a power
factor correction circuit, we conclude that Petitioner has established by a
preponderance of evidence that claims 7 and 21 would have been obvious as
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of the critical date based on the combination of either APA and Hancock or
APA and Gordon.
I. Claim 10
Claim 10 requires that the power factor correction circuit include a
control circuit, at least one switching transistor, and an inductor configured
in a boost arrangement, the control circuit operating to minimize harmonic
distortion at the AC source.
We note that the ’153 patent specification admits that boost-
configuration circuits were well-known at the time of invention. Ex. 1001,
3:55–61. Petitioner’s declarant also testifies that boost circuits were known.
Ex. 1004 ¶¶ 26, 46, 98–100.
Furthermore, Hancock states that without power factor correction,
input AC current spikes “result[] in high harmonic content.” Ex. 1002, 6.
The power factor correction circuit described by Hancock minimizes that
harmonic content. Ex. 1004 ¶ 99.
Turning to Gordon, it discloses that “harmonics due to the non-
sinusoidal shape of the input current” are a problem that causes poor power
factor, and states that “power factor is low, and input current harmonics are
high.” Ex. 1003, 7, 10. Gordon further explains that a “boost converter”
power factor correction circuit results in an “absence of harmonics.” Id. at
10; Ex. 1004 ¶ 100.
Thus, we are persuaded that both Gordon and Hancock demonstrate
that it was known to use a power factor correction circuit in an audio
amplifier.
Based on the evidence and the record before us, we are persuaded that
Petitioner has established by a preponderance of evidence that claim 10
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would have been obvious as of the critical date based on the combination of
either APA and Hancock or APA and Gordon.
J. Claim 11
Claim 11 requires that the power factor correction circuit include a
control circuit operating to minimize the root-mean-square (RMS) value of
the input current drawn from the AC source.
According to Petitioner’s declarant, a power factor correction circuit
inherently minimizes the RMS value of the input current; that is its function.
Ex. 1004 ¶ 103.
With regard to Hancock, Figure 28 shows a power factor correction
circuit causing input current to match input voltage and minimize the RMS
value of the input current. Ex. 1004 ¶ 103. Furthermore, Gordon notes that
“use of power factor correction allows the switching power supply to draw
less current.” Ex. 1003, 10.
Based on the evidence and the record before us, we are persuaded that
Petitioner has established by a preponderance of evidence that claim 11
would have been obvious as of the critical date based on the combination of
either APA and Hancock or APA and Gordon.
K. Claim 12
Claim 12 requires that the power factor correction circuit include a
control circuit operating to maximize power transfer characteristics from the
AC source to the load.
According to Petitioner’s declarant, a power factor correction circuit,
such as the one described in Hancock and Gordon, inherently maximizes
power transfer characteristics from the AC source to the load. Ex. 1004
¶ 107. Furthermore, Hancock’s Figure 28 shows a power factor correction
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circuit causing input current to match input voltage and, thus, maximize
power factor. Id. As Petitioner’s declarant testifies, maximizing power
transfer characteristics from the AC source to the load is the very point of
using a power factor correction circuit. See Ex. 1004 ¶¶ 107–109. We are
further persuaded by Petitioner’s argument that the ’153 patent specification
relies on the well-known circuit configurations and operation details of
power factor correction. Pet. 16.
Based on the evidence and the record before us, we are persuaded that
Petitioner has established by a preponderance of evidence that claim 12
would have been obvious as of the critical date based on the combination of
either APA and Hancock or APA and Gordon.
L. Claim 13
Claim 13 requires that the power factor correction circuit include a
control circuit operating to maintain the maximized power transfer
characteristics from the AC source to the load at a substantially constant
level irrespective of variations in RMS voltage and frequency of the AC
source.
According to Petitioner’s declarant, a power factor correction circuit
inherently maintains maximized power transfer characteristics from the AC
source to the load at a substantially constant level irrespective of variations
in RMS voltage and frequency of the AC source. Ex. 1004 ¶ 111.
Hancock discloses that the DC power supply can operate between 90
and 260 VAC, and that the secondary regulator sees a “relatively stabilized
voltage.” Ex. 1002, 6.
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Gordon states that with a power factor correction circuit, “[t]his
design can operate from both US and European line voltages,” which vary in
both voltage and frequency. Ex. 1003, 10; see Ex. 1004 ¶¶ 25, 114.
Based on the evidence and the record before us, we are persuaded that
Petitioner has established by a preponderance of evidence that claim 13
would have been obvious as of the critical date based on the combination of
either APA and Hancock or APA and Gordon.
M. Claim 14
Claim 14 requires that the power factor correction circuit operate to
maintain its power transfer characteristics from the AC source to the load at
a substantially constant level, despite RMS voltage variations of about 20%
at the AC source. According to Petitioner’s declarant, a power factor
correction circuit inherently maintains power transfer characteristics from
the AC source to the load at a substantially constant level despite RMS
voltage variations of about 20% at the AC source. Ex. 1004 ¶ 111.
Hancock discloses a switching power supply that operates over a
range of 90–260 VAC, a range much greater than a variation of twenty
percent, and provides a “relatively stabilized voltage.” See Ex. 1002, 6;
Ex. 1004 ¶¶ 114–115.
Gordon describes a switching power supply with an input voltage
range of “105 – 125 VAC,” which is about 20 percent. Ex. 1003, 7. Gordon
states that with a power factor correction circuit, “[t]his design can operate
from both US and European line voltages,” which differ by more than 20
percent. Id. at 10; Ex. 1004 ¶¶ 25, 114.
Based on the evidence and the record before us, we are persuaded that
Petitioner has established by a preponderance of evidence that claim 14
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would have been obvious as of the critical date based on the combination of
either APA and Hancock or APA and Gordon.
N. Claim 15
Claim 15 requires that the power factor correction circuit maintain
power transfer characteristics from the AC source to the load at a
substantially constant level, despite frequency variations of the AC source
from about 50 to 60 Hz. According to Petitioner’s declarant, a power factor
correction circuit inherently maintains power transfer characteristics from
the AC source to the load despite frequency variation of the AC source from
about 50 to 60 Hz. Pet. 37 citing Ex. 1004 ¶¶ 117–118.
Hancock discloses a power supply that can produce a relatively
stabilized voltage for the secondary converter over an input voltage that
varies in frequency from 50–60Hz. Ex. 1002, 6; Ex. 1004 ¶ 117.
Gordon describes a power supply with power factor correction that
operates on U.S. line voltages (60 Hz.) and European voltages (50 Hz.).
Ex. 1003, 10.
According to Petitioner’s declarant, Dr. Santi, a person of ordinary
skill in the art would have considered the subject matter of claim 15 to have
been obvious, because it was commonplace to design power supplies and
power factor correction circuits to operate with 50 Hz and 60 Hz AC
sources. Ex. 1004 ¶ 116.
Based on the evidence presented and the record before us, we are
persuaded that Petitioner has established by a preponderance of evidence
that claim 15 would have been obvious as of the critical date based on the
combination of either APA and Hancock or APA and Gordon.
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V. CONCLUSIONS
For the reasons set forth above, we are persuaded that Petitioner has
shown by a preponderance of the evidence that:
(1) Hancock and Gordon are prior art printed publications;
(2) claims 1–22 are unpatentable under 35 U.S.C. § 103(a) as
obvious over APA and Hancock;
(3) claims 1–22 are unpatentable under 35 U.S.C. § 103(a) as
obvious over APA and Gordon;

VI. ORDER
Accordingly, it is
ORDERED that Patent Owner’s Motion to Exclude is DENIED;
FURTHER ORDERED that claims 1–22 of U.S. Patent 6,023,153
have been shown to be unpatentable; and
FURTHER ORDERED that because this is a final written decision,
parties to the proceeding seeking judicial review of the decision must
comply with the notice and service requirements of 37 C.F.R. § 90.2.

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FOR PETITIONER:

Rodney C. Tullett
Chun M. Ng
Kaustav Das
Grant Kinsel

PERKINS COIE LLP

RTullett@perkinscoie.com
CNg@perkinscoie.com
KMDas@perkinscoie.com
GKinsel@perkinscoie.com

FOR PATENT OWNER:

N. Andrew Crain
Robert Gravois
Kenneth Knox

THOMAS | HORSTEMEYER, LLP

andrew.crain@thomashorstemeyer.com
robert.gravois@thomashorstemeyer.com
kenny.knox@thomashorstemeyer.com
vivek.ganti@thomashorstemeyer.com