QSC Audio Products, LLCv.Crest Audio, Inc.

Patent Trial and Appeal Board

Apr 29, 2015

08546839 (P.T.A.B. Apr. 29, 2015)

Trials@uspto.gov Paper 41
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 IPR2014-00129
Patent 5,652,542
____________

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
Corrected Petition (Paper 6, “Pet.”) to institute an inter partes review of
claims 1–13 (all claims) of U.S. Patent No. 5,652,542 (Ex. 1001, “the ’542
patent”) pursuant to 35 U.S.C. §§ 311–319. Petitioner indicates that the
’542 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, and Crest Audio, Inc. v.
QSC Audio Products, LLC, 3:13-cv-610 DPJ-FKB, filed in the United States
District Court for the Southern District of Mississippi, Jackson Division.
Pet. 1.
On May 2, 2014 we granted the Petition as to claims 5 and 13 of the
’542 patent and instituted trial on one ground of unpatentability as set forth
below. Paper 12, “Dec. on Inst.”

Claims Ground Reference
5 and 13 § 103 Porambo1, Black2,
Gittleman3, and
Tsurushima4

Patent Owner, Crest Audio, Inc. (“Crest” or “Patent Owner”) argues
in the Response that, inter alia, that Gittleman is not a published reference
(Paper 21, “PO Resp.”), and filed a Motion to Exclude (Paper 32, “Motion”

1 US 5,450,624 (Ex. 1005, “Porambo”).
2 WO 92/22133 (Ex. 1006, “Black”).
3 Martin Gittleman, “A Fail-Safe Audio Power Amplifier,” AUDIO
ENGINEERING SOCIETY PREPRINT 835 (L-5) (1971) (Ex. 1009,
“Gittleman”).
4 US 3,912,981 (Ex. 1010, “Tsurushima”).
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or “Mot.”), seeking to exclude it as evidence. Petitioner replied (Paper 26,
“Pet. Reply”) to Patent Owner’s response and opposed (Paper 35,
“Opposition”) Patent Owner’s Motion to Exclude. Oral Argument was held
on January 27, 2015. Paper 40, “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 not demonstrated by a preponderance
of the evidence that either claim for which trial was instituted, claims 5 and
13, is unpatentable.
II. THE ’542 PATENT (Ex. 1001)
The ’542 patent is directed to an audio amplifier with a power
amplifier and a digital signal processor (“DSP”) that is capable of receiving
and storing at least one algorithm that defines a signal processing function
and signal processing function parameters. Ex. 1001, 6:1–7, 7:39–46. The
amplifier includes a controller (microprocessor) that receives control signals
from ports 206 and 208 that define a program and program data that sets the
signal processing functions and function parameters for the DSP. Id.
Microprocessor 290 gathers the controls signals and/or the signal processing
programs to be loaded into the digital signal processor. Id.
In one embodiment, the DSP has an input for receiving the algorithm
and the signal processing function parameters and an input/output port for
receiving performance characteristics of the power amplifier, and for
transmitting control signals for modifying the performance of the power
amplifier. Ex. 1001, 5:45–55, 7:47–53. In another embodiment, the DSP
calculates the impedance of a load from detected current and voltage. Id. at
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3:25–39. In another embodiment, the DSP calculates the amount of power
delivered to the load based on a detected voltage and current. Id.
The challenged claims, independent claims 5 and 13, are reproduced
below.
5. An amplifier comprising:

a power amplifier; and

a digital signal processor capable of
receiving and storing at least one of an algorithm
which defines at least one signal processing
function and signal processing function
parameters, the digital signal processor being
connected to the power amplifier;

a current detector for detecting current
delivered to a load from the power amplifier and a
voltage detector for detecting the voltage supplied
to the load from the power amplifier,
wherein the digital signal processor further
comprises an input port for receiving the detected
current and voltage, and
wherein the current detector and voltage detector
are operatively connected to the power amplifier
and the digital signal processor, and
wherein the digital signal processor calculates the
impedance of the load.

13. An amplifier comprising:

a power amplifier; and

a digital signal processor capable of
receiving and storing at least one of an algorithm
which defines at least one signal processing
function and signal processing function
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parameters, the digital signal processor being
connected to the power amplifier;

a current detector for detecting current
delivered to a load from the power amplifier and a
voltage detector for detecting the voltage supplied
to the load from the power amplifier,
wherein the digital signal processor further
comprises an input port for receiving the detected
current and voltage, and
wherein the current detector and voltage detector
are operatively connected to the power amplifier
and the digital signal processor, and
wherein the digital signal processor calculates the
amount of power supplied to the load by the power
amplifier based on the detected voltage and the
detected current.
III. MOTION TO EXCLUDE
Patent Owner argued in its Response (Paper 21) and in its Motion to
Exclude that Gittleman is not a “printed publication” under the patent law,
and that it should be excluded from evidence.
A. Critical Date
The ’542 patent issued from application 08/546,839 filed on
October 23, 1995. The application is a continuation of abandoned
application 08/336,481, which was filed on November 9, 1994, the critical
date. Ex. 1001, cover page elements [21], [22], [63]. Therefore, to be
considered “prior art,” the asserted references must have an effective date
that predates the critical date of November 9, 1994.
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B. Authentication
Patent Owner argues that Fed. R. Evid. 9015 and 9026 prevent our
consideration of Gittleman because it is not authenticated as a “publication”
under the patent law. Mot. 1. Authenticating rules are 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.”

5 Authenticating or Identifying Evidence.
6 Evidence that is Self-Authenticating.
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The cover page of Gittleman is reproduced below. Ex. 1009, 1.

Cover page of the Gittleman reference

The cover page: (1) bears a distinctive logo 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
was presented; and (6) states how additional preprints may be obtained. Id.
With regard to the dates of the relevant AES Conventions, according
to Gittleman’s cover page, the 41st AES Convention took place from
October 5–8, 1971. Ex. 1009, 1.
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Petitioner provides declaration testimony of Jessica King (Ex. 2004,
“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 Gittleman from that
website. Id. at 2–3. She further testifies that “search results” show that AES
indicates a publication date for Gittleman as being October 1, 1971. Id. at
2–3.
Patent Owner argues that these search results do not authenticate
Gittleman because they are inadmissible hearsay under Fed. R. Evid. 802.
Mot. 2. 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 1–2.
Petitioner disagrees and argues that to authenticate Gittleman
Petitioner simply “must produce evidence sufficient to support a finding that
the item is what the [Petitioner] claims it is.” Opposition, 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 page of Gittleman to
authenticate these exhibits under Rule 901(b)(4). Opposition, 2–4.
Furthermore, the various indicia on the Gittleman cover page are similar to
the indicia found on the Cordell paper (Ex. 1016) presented at the 72nd AES
Convention, as testified to by Patent Owner’s expert. See Ex. 1016, 1.
Patent Owner’s arguments conflate two separate issues — (1) whether
Gittleman is authentic, and (2) whether it constitutes a publication under the
patent law. Gittleman includes the AES logo. The cover page further
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identifies a specific address for AES for the purpose of obtaining additional
preprints, and states that reproduction of the article is prohibited without
permission from the Audio Engineering Society Journal. Ex. 1009. There is
no dispute that this document is a preprint of a paper intended for
presentation at their respective AES conventions. Therefore, having
considered and weighed the distinctive characteristics of the article and the
circumstances surrounding its retrieval from the AES E-Library, we find that
Gittleman is what it appears to be — a paper categorized by the Audio
Engineering Society as a “preprint.” Petitioner has met its authentication
burden under Fed. R. Evid. 901 and 902. Whether the self-authenticated
“preprint” qualifies as a “publication” 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)) and because printed publications
must have been published before the critical date of the challenged patent in
order to constitute prior art, we must determine whether Gittleman was
published before November 9, 1994, the critical date. To prove the
publication date of Gittleman, Petitioner relies on the information printed on
the cover page of this preprint, namely that it was “presented” at an AES
convention in 1971. See Pet. 4. Patent Owner argues that Gittleman should
be excluded because the statement of dates on the cover page, e.g.,
“PRESENTED AT THE 41ST CONVENTION OCTOBER 5–8, 1971” on
the cover of Gittleman, is hearsay evidence attempting to establish a date of
publication. Mot. 3 (citing Fed. R. Evid. 802).
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Petitioner argues that Patent Owner’s challenges under Fed. R.
Evid. 802 fail because the statement is not hearsay—Gittleman has been
authenticated as a “conference paper that was published as of the date shown
on the cover page, [and] Petitioner is not relying on the statement that
appears on the face of the Gittleman paper for the truth of the matter
asserted.” Opposition 7. Alternatively, Petitioner argues that even if the
statement was hearsay, it would come within the ancient documents (Fed. R.
Evid. 803(16)) or the residual hearsay (Fed. R. Evid. 807) exceptions to the
hearsay rule. Id. at 810.
We are not persuaded by Petitioner’s argument that the statement is
not hearsay. Although Gittleman has been authenticated as a preprint
maintained by AES, Petitioner relies on the truth of the matter asserted on
the face of the preprint, i.e., that it was presented at the AES convention on
the date stated on the cover page. Without the statement, there is no
evidence that Gittleman actually was available, as a printed publication, at
the convention or on any other particular date. We note that Patent Owner
does not argue that this document was not associated with the AES
convention. The question for us to decide is whether Petitioner has provided
sufficient evidence and argument showing that the statement relied on is
admissible under an exception to the hearsay rule. We find that, in this
situation, the statement should not be excluded as hearsay, because it comes
within two separate exceptions to the hearsay rule.
The preprint qualifies as an ancient document subject to Fed. R. Evid.
803(16), which applies to documents that are at least 20 years old and whose
authenticity is established. Per our discussion above, Gittleman is
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authenticated. The Gittleman preprint purports to have been presented
October 5–8, 1971, more than 20 years ago. Ex. 1009, 1.
The preprint also meets 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 it 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 911. For
example, Petitioner argues circumstantial guarantees of trustworthiness by
virtue of all the indicia on the cover page of the document 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 statement
is evidence of a material fact: convention date set forth on the preprint. Id.
Furthermore, Petitioner argues that the date on the cover page is 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 statement as evidence of the date of
publication serves the interest of justice. Id. Although we recognize that
Petitioner had other avenues of proving this statement was 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,
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Petitioner has provided AES website documents (also self-authenticated)
that corroborate similar dates as those stated on the cover page of the
reference. Furthermore, the dates of the documents cited within the
reference are all before the date of the stated presentation of the document.
Yet another fact we consider is that the cover pages of all the AES preprints
submitted into evidence have the same information, and sufficient detail
regarding the AES convention and the manner in which the preprints may be
obtained. See also Ex. 1015, 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
evidence and arguments, we find that the statement on the cover page of
Gittleman regarding presentation of the preprint at the particular AES
convention is admissible.
D. Conclusion
For reasons stated above, Patent Owner’s Motion to Exclude is
denied.
IV. ANALYSIS OF CLAIM CHALLENGES
A. Gittleman is a Publication
Patent Owner argues that Gittleman is not a “publication” 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, suggests
strongly that it is the custom and practice of the AES to prepare and
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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 Gittleman preprint
was made available to attendees of their respective AES Conventions. We
further conclude that the Gittleman AES convention took place prior to the
critical date. Thus, Gittleman was accessible to those of ordinary skill as of
the stated convention date, well before the critical date. We, therefore,
conclude that Gittleman is a publication 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 Gittleman is not
a publication. 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 Gittleman is a publication within the meaning of the patent
law.
B. Level of Ordinary Skill
Petitioner asserts that a person of ordinary skill in the art would have
had the following education and experience: Master of Science degree in
Electrical Engineering and at least some practical experience with the design
and testing of electronic amplifiers. Ex. 1003 ¶ 15. Patent Owner’s
declarant agrees generally with the above assertion, asserting that a person
of ordinary skill in the art would have had one year of experience with the
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design and testing of electronic amplifiers. Ex. 2001 ¶ 27. The
disagreement appears to be that the Petitioner asserts that a person of
ordinary skill would be aware of amplifier designs useful at frequencies
ranging from audio frequencies to radio frequencies (RF) (Ex. 1003 ¶ 16),
while Patent Owner asserts that a person of ordinary skill would not have
practical experience with amplifier designs useful at frequencies ranging
from audio frequencies to radio frequencies (RF) (Ex. 2001 ¶¶ 28–30). We
credit Petitioner’s declarant, and agree that a person of ordinary skill would
be at least aware of amplifier designs useful at radio frequencies (RF) based
at least on that person’s educational background. Ex. 1003 ¶ 16.
We determine the obviousness issues guided by the evidence of the
level of ordinary skill in the art presented by the references themselves. See
Okajima v. Bourdeau, 261 F.3d 1350, 1355 (Fed. Cir. 2001). From the
Porambo reference, which Patent Owner does not contest is in the field of
endeavor of the invention in question, we understand that the level of
ordinary skill in the art, at a minimum, pertains to audio amplifiers and the
incorporation of DSPs in audio amplifiers. See Ex. 1005, Abstract
(describing the features of the audio amplifiers and DSPs at issue in
Porambo).
C. Dr. Ellis’s Qualification to Provide Expert Opinions
Patent Owner argues that Petitioner’s declarant, Dr. Ellis, is not
“credible” to perform as an expert in this case because of his lack of
experience designing audio power amplifiers pointing to: (1) his alleged
lack of experience designing audio amplifiers (PO Resp. 17–20); (2) an
alleged bias toward DSP solutions (PO Resp. 20–23); (3) his alleged use of
the wrong standard for obviousness (PO Resp. 23–24); (4) his alleged lack
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of knowledge of RF Amplifiers (PO Resp. 24–26); and (5) the alleged short
amount of time he spent reviewing this case (PO Resp. 26–29). Patent
Owner argues that, unlike Dr. Ellis, its declarant Bob Cordell has significant
practical experience designing audio power amplifiers at the time of
invention. Ex. 2001 ¶¶ 26–27.
As to his audio amplifier experience, Dr. Ellis completed a Master of
Science degree in Electrical Engineering with numerous years of experience
as a research assistant researching audio signal processing, sound synthesis
and analysis. Ex. 1004, 1. Dr. Ellis stated during his deposition that,
although he is an expert in digital signal processing (Ex. 2002, 154:15–16),
he has experience in the design of amplifiers from his undergraduate
education. Id. at 124:7–20. Dr. Ellis designed and tested microphone
amplifiers as a post-doctoral student at the Computer Science Institute at
Berkeley, id. at 111:13–113:4, and is currently designing amplifiers that can
drive speakers with the goal of incorporating these into his professional
work. Id. at 120:4–121:12. We also note, as discussed above, the field of
the ’542 patent invention is related to audio amplifiers generally and the
incorporation of DSPs. We find that although Dr. Ellis is less qualified than
Mr. Cordell in the area of amplifier design, he is qualified sufficiently to
testify about audio amplifiers as they relate to DSPs.
As to his alleged bias, Patent Owner points to Dr. Ellis’s testimony
that “DSP revolution” has occurred, where DSP solutions were preferred
over analog solutions. PO Resp. 20–23. We do not agree with Patent
Owner that this indicates that he is biased toward believing that “any DSP
application that replaces an analog application is obvious.” See PO
Resp. 23.
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As to his alleged use of the wrong standard for obviousness, Patent
Owner argues that Dr. Ellis did not evaluate the prior art from the
perspective of a person having ordinary skill in the art at the time of
invention because apparently he did not use the words “at the time of
invention” when discussing the standard in his declaration. PO Resp. 23–24.
We are not persuaded by this argument.
Patent Owner also argues that Dr. Ellis must himself be a person of
ordinary skill in the art. PO Resp. 24. Patent Owner’s arguments are
unpersuasive because, to testify as an expert under FRE 702, a person need
not be a person of ordinary skill in the art, but rather “qualified in the
pertinent art.” Sundance, Inc. v. DeMonte Fabricating Ltd., 550 F.3d 1356,
1363–64 (Fed. Cir. 2008); see SEB S.A. v. Montgomery Ward & Co., Inc.,
594 F.3d 1360, 1372–73 (Fed. Cir. 2010); Mytee Prods., Inc. v. Harris
Research, Inc., 439 F. App’x 882, 886–87 (Fed. Cir. 2011) (non-
precedential) (upholding admission of the testimony of an expert who “had
experience relevant to the field of the invention,” despite admission that he
was not a person of ordinary skill in the art). As noted above, Dr. Ellis is
qualified in the pertinent art.
Patent Owner argues that Dr. Ellis’s lack of knowledge regarding
class C RF amplifiers renders his opinions of little or no credibility. PO
Resp. 25. Patent Owner has not explained how specific knowledge of the
characteristics of class C RF amplifiers is directly relevant to the issues in
this case as opposed to a general knowledge of RF amplifiers. Thus, we are
not persuaded that Dr. Ellis’s alleged lack of this particular knowledge
renders his opinions of little or no credibility.
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Finally, Patent Owner argues that Dr. Ellis spent an unreasonably
short amount of time reviewing this case before providing his opinion, i.e.
only ten hours. PO Resp. 26–29. We find that the amount of time Dr. Ellis
chose to spend with the case is likely based on his experience with the
subject matter and the difficulty of the subject matter. Thus, we are not
persuaded by Patent Owner’s argument that the time spent on the proffered
opinion affects the weight we give his opinions.
D. Claim Construction
In an inter partes review, claim terms in an unexpired patent are given
their broadest reasonable construction in light of the specification of the
patent in which they appear. 37 C.F.R. § 42.100(b). Under the broadest
reasonable construction standard, claim terms are given their ordinary and
customary meaning, as would be understood by one of ordinary skill in the
art in the context of the entire disclosure. In re Translogic Tech., Inc., 504
F.3d 1249, 1257 (Fed. Cir. 2007). Any special definition for a claim term
must be set forth with reasonable clarity, deliberateness, and precision. In re
Paulsen, 30 F.3d 1475, 1480 (Fed. Cir. 1994).
The following claim constructions apply.
1. at least one of an algorithm which defines at least
one signal processing function and signal processing
function parameters (claims 5 and 13)

As to the claim term “at least one of an algorithm which defines at
least one signal processing function and signal processing function
parameters,” Petitioner argues that “[t]he use of the phrase ‘at least one of
an’ in the independent claims makes it clear that the DSP has to be capable
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of receiving an algorithm or signal processing function parameters or both.”
Pet. 13.
Petitioner points out that the Specification discloses that “[t]he
microprocessor 290 gathers control signals and/or signal processing
programs to be loaded into the digital signal processor.” Ex. 1001, 5:25–27.
This quotation, however, simply notes that the DSP can load control signals
or signal processing programs. The Specification also notes that “[t]he
control signals input from the ports 206 and 208 define a program [function]
and program data [parameters] that sets the signal processing functions and
function parameters.” Id. at 22-25. Thus, the Specification suggests that
both the functions and parameters are transmitted to the DSP.
Additionally, the Federal Circuit, when faced with similar claim
language, determined that the phrase “at least one” followed by a list of
categories separated by “and,” rather than “or,” suggests a conjunctive list in
which each one of the members of the list is necessary to satisfy the claim.
SuperGuide Corp. v. DirecTV Enters., Inc., 358 F.3d 870, 885–86 (Fed. Cir.
2004) (“A common treatise on grammar teaches that ‘an article of a
preposition applying to all the members of the series must either be used
only before the first term or else be repeated before each term.’” (quoting
William Strunk, Jr. & E.B. White, The Elements of Style 27 (4th ed.
2000))). SuperGuide points out that each term in the list embraces a
different category, each of which must take on a chosen value: “Every
disclosed embodiment teaches that the user must choose a value for each
designated category.” Id. at 887. That is the case here, where functions have
associated parameters.
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For the above reasons, consistent with the plain English meaning and
the Specification, we construe “at least one of an algorithm which defines at
least one signal processing function and signal processing function
parameters” to require that both a signal processing function and a signal
processing parameter must be present in the prior art to meet that claim
limitation.
2. power amplifier (claims 5 and 13)

Patent Owner argues that the phrase “power amplifier” means “an
electronic circuit that amplifies low-power audio signals to a level suitable
for driving loudspeakers.” PO Resp. 13. Patent Owner argues that the field
of the invention is audio amplification, and that the abstract of the
’542 patent “contemplates the processing of audio signals as the purpose of
the invention for playback via a loudspeaker.” Id. at 13–14.
Under a broadest reasonable interpretation, words of the claim must
be given their plain meaning unless the plain meaning is inconsistent with
the specification. In re Zletz, 893 F.2d 319, 321 (Fed. Cir. 1989).
Limitations from the specification are not to be read into the claims. In re
Van Geuns, 988 F.2d 1181, 1184 (Fed. Cir. 1993); see also Superguide, 358
F.3d at 875 (“Though understanding the claim language may be aided by the
explanations contained in the written description, it is important not to
import into a claim limitations that are not part of the claim. For example, a
particular embodiment appearing in the written description may not be read
into a claim when the claim language is broader than the embodiment.”); cf.
Merck & Co., Inc. v. Teva Pharm. USA, Inc., 395 F.3d 1364, 1372 (Fed.
Cir. 2005) (reversing the district court's construction of the term “about”
because the interpretation was inconsistent with the specification).
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The preferred embodiment of the ’542 patent is directed to processing
audio signals for playback to loudspeakers, but claims 5 and 13 are broader
in scope, and do not recite loudspeakers or audio signals. Therefore, we
decline to limit the term “power amplifier” as Patent Owner suggests. We
find that the term “power amplifier” does not need explicit construction in
this case.
3. a digital signal processor capable of receiving and
storing (claims 5 and 13)

Patent Owner argues that the phrase “a digital signal processor
capable of receiving and storing” should be given its plain and ordinary
meaning. PO Resp. 14. Patent Owner argues that, because that claims recite
“an amplifier comprising . . . a digital signal processor,” “the digital signal
processor must be installed in the amplifier when it receives and stores. So,
the ‘capable of receiving and storing’ limitation occurs in the amplifier.” Id.
at 14. We disagree.
Claims 5 and 13 are not method claims, and are silent as to when the
“capability to receive” must occur. Additionally, the claims are silent as to
the physical configuration of the components of the amplifier. We decline to
limit the term a “digital signal processor capable of receiving and storing” as
Patent Owner suggests. Therefore, we find that the term “digital signal
processor capable of receiving and storing” does not require the digital
signal processor must be installed in the amplifier when it receives and
stores.
E. Overview of Prior Art References
Porambo discloses an amplifier with programmable DSP chipset 28
that has an input for receiving and storing a speaker testing function, as well
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as threshold values that are used to detect if speakers are properly connected.
Ex. 1005, 5:21–25, 6:18–22. During testing, DSP chipset 28 receives a
clipping signal produced by a power amplifier, and, based on that signal,
transmits modified testing signals. Id. at 5:1–20. Thus, DSP chipset 28
reduces distortion in the power amplifier by ensuring that the modified
testing signals are within a range that avoids such distortion. Id.
Black discloses an amplifier with an output protection circuit that
includes a DSP. The DSP is programmed to keep the power amplifier out of
saturation in order to protect the power amplifier and increase its efficiency.
Ex. 1006, 3:22–26, 9:12–25. Black discloses that the DSP has an
input/output port that receives a signal indicative of amplifier saturation on
line 233 and an input/output port (feeding D/A (Digital to Audio Converter)
221) that transmits control signals to D/A 221 for lowering input signal 231,
thus ensuring that the amplifier does not reach a saturation level. Id. at
9:12–25, Fig. 2.
Gittleman illustrates the process of monitoring output current and
voltage in a feedback loop to control amplifier gain. Ex. 1009, Fig. 1. In
Gittleman, a limiting circuit senses potentially unsafe conditions of the
output voltage, current, and temperature, and limits the dissipation of the
output transistors to an acceptable level. Id. at 4.
Tsurushima illustrates a protection circuit for an audio amplifier that
operates based on detected output voltage and current levels. Tsurushima
discloses an amplifier having circuit 14 that detects output current and
voltage in order to determine the impedance of a load. When the impedance
drops below a predetermined value, switching circuit 15 in the amplifier is
closed, which removes essentially the input from the output stage of the
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amplifier in order to protect it from overloading. Ex. 1010, 8:63–68, 9:1–7,
10:33–40.
F. Independent Claims 5 and 13
Our substantive inquiry focuses on whether the record before us
presents sufficient evidence for us to conclude that, at the time of the ’542
patent invention, it would have been obvious to a person of ordinary skill in
the relevant art to have a DSP in combination with a power amplifier, where
the DSP receives a digital signal processing function and parameters and
also receives detected current and voltage to calculate impedance or power.
We are not persuaded that the evidence and arguments presented show by a
preponderance of the evidence that the combination would have been
obvious.
Claims 5 and 13 further recite:
a current detector for detecting current delivered to a load from
the power amplifier and a voltage detector for detecting the
voltage supplied to the load from the power amplifier,
wherein the digital signal processor further comprises an input
port for receiving the detected current and voltage, and
wherein the current detector and voltage detector are
operatively connected to the power amplifier and the digital
signal processor.

Emphasis added. The detected current and voltage are then used to
calculate either impedance (claim 5) or power (claim 13).
Petitioner asserts that both Gittleman’s and Tsurushima’s disclosure
of detecting the output current and voltage of an amplifier to provide output
protection meets a portion of this limitation. Pet. 38–39 (citing Ex. 1009, 4,
Fig. 1; Ex. 1010, 8:62–68). Petitioner further asserts that Tsurushima’s
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disclosure of a voltage and current detection circuit that is connected to a
power amplifier meets another portion of this limitation. Id. at 39 (citing Ex.
1010, Fig. 6).
Petitioner admits that neither of the references with a DSP (Porambo
and Black) teaches a voltage and current value being input into that DSP.
Tr. 49:17–21. Rather, Porambo and Black teach a binary, yes-no, indication
input into the DSP. Ex. 2002, 198:13–199:2; Ex. 2001 ¶¶ 137, 149.
Petitioner asserts that the detection circuit of either Gittleman or Tsurushima
could be combined with input in Black that monitors the power output of the
amplifier, thus creating an operable connection between the amplifier, the
DSP, and the detectors, as required by claims 5 and 13. Pet. at 32–33, 37
(citing Ex. 1006, 8, 10–25).
Patent Owner argues that Porambo and Black simply infer the voltage
or saturation level at the power amplifier, rather than detect voltage. PO
Resp. 37. Patent Owner, through its declarant, argues that a person of
ordinary skill in the art would not break the internal connections and
reconnect them to a DSP because the V-I limiter of Tsurushima is
preconfigured to detect a specific voltage. PO Resp. 39. Additionally,
Patent Owner, through its declarant, argues that Gittleman simply detects
internal currents in the amplifier and uses them to protect the amplifier. PO
Resp. 41–42.
Petitioner disagrees. Petitioner’s declarant Dr. Ellis states that:
[I]t is basic electrical engineering that the output power of an
amplifier can be computed from the product of its output
current and output voltage. Black teaches that output power of
an amplifier can be monitored by a DSP and used to provide
output protection for the power amplifier. A person of ordinary
skill in the art would have been motivated to use the output
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current and voltage as disclosed in Gittleman or Tsurushima as
a way of detecting the output power of the amplifier from its
output current and output voltage.

Ex. 1003 ¶ 65. The question before us is whether one of ordinary skill in the
art would take the analog output protection circuits and access the detected
current and voltage inside those circuits, then input them into the DSP of
Porambo or Black, rather than use the output protection scheme already
disclosed in Black.
Petitioner analogizes this case to Leapfrog Enters., Inc. v. Fisher-
Price, Inc., 485 F.3d 1157 (Fed. Cir. 2007) (“Leapfrog”). In particular,
Petitioner points out the Federal Circuit’s statement that “[a]ccommodating a
prior art mechanical device that accomplishes that goal to modern
electronics would have been reasonably obvious to one of ordinary skill.”
Id. at 1161.
We note that in Leapfrog:
the goal of the [claimed] device was to allow a child to press a
switch associated with a single letter in a word and hear the
sound of the letter as it is used in that word. In this way, the
child would both associate the sound of the letter with the letter
itself and be able to sound out the word one letter at a time to
learn to read phonetically.

Id. The prior art in Leapfrog accomplished this same task except the
switch activated a phonograph rather than activating an electronically
created sound. Id. Here the prior art does not perform an identical task.
Claims 5 and 13 require detecting voltage and current values for the purpose
of making a calculation. None of the cited references perform this task
digitally or in analog.
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As noted above, Petitioner’s declarant has more experience related to
DSPs while Patent Owner’s declarant has more experience with audio power
amplifiers. As to whether it would be obvious to modify an existing output
protection scheme in a power amplifier, we credit the analysis and opinions
of Patent Owner’s declarant.
The law allows for us to apply common sense in deciding if a missing
limitation nonetheless would have been arrived at by a person of ordinary
skill in the art. See Perfect Web Techs., Inc. v. InfoUSA, Inc., 587 F.3d
1324, 1329 (Fed. Cir. 2009) (In KSR Int’l Co. v. Teleflex Inc., 550 U.S. 398,
421 (2007), “the Supreme Court instructed that factfinders may use common
sense in addition to record evidence.”). “[A] person of ordinary skill is also
a person of ordinary creativity.” KSR, 550 U.S. at 421. Here, however, the
missing limitation is not a matter of common sense. For example, Black has
been shown to have no need for a DSP that detects voltage and current
values for calculating impedance or power, because Black infers a saturation
level at the power amplifier stage. Implementing changes to Black’s DSP to
achieve the claim limitation requires a modification that, we find, goes
beyond a common sense application and presents the question of what would
motivate such a modification. On this last point, we find that Petitioner has
not shown by a preponderance of the evidence a rationale for receiving the
recited values in order to perform a calculation. Petitioner does not point to
a motivation to replace or modify the scheme of Black or Porambo with the
’542 patent’s scheme of detecting current and voltage to perform
calculations of power and impedance. “Where . . . the necessary reasoning
is absent, we cannot simply assume that ‘an ordinary artisan would be
awakened to modify prior art in such a way as to lead to an obviousness
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rejection.’” Plantronics, Inc. v. Aliph, Inc., 724 F.3d 1354, 1353 (Fed. Cir.
2013) (citation omitted).
Thus, upon review of Petitioner’s analysis and supporting evidence
and Patent Owner’s analysis and evidence in rebuttal, we determine that
Petitioner has not shown by a preponderance of the evidence that claims 5
and 13 would have been obvious over the combination of Gittleman,
Tsurushima, Porambo, and Black.
V. CONCLUSIONS
For the reasons set forth above, we are persuaded that Petitioner has
shown by a preponderance of the evidence that Gittleman is a publication
within the meaning of the patent law but has not shown by a preponderance
of the evidence that claims 5 and 13 are unpatentable under 35 U.S.C.
§ 103(a) as obvious over Porambo, Black, Gittleman, and Tsurushima.

VI. ORDER
Accordingly, it is
ORDERED that Patent Owner’s Motion to Exclude is denied;
FURTHER ORDERED that Petitioner has not demonstrated by a
preponderance of the evidence that claims 5 and 13 of U.S. Patent 5,652,542
are 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
Kaustuv Das

PERKINS COIE LLP

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

FOR PATENT OWNER:

N. Andrew Crain
Robert Gravois
Kenneth Knox
Vivek A. Ganti

THOMAS | HORSTEMEYER, LLP

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