`
`
`
`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: Unassigned
`
`Patent No. 6,023,153
`
`
`
`PETITION FOR INTER PARTES REVIEW
`OF U.S. PATENT NO. 6,023,153
`
`
`
`29671-0024.0003/LEGAL28322641.1
`
`

`

`TABLE OF CONTENTS
`(continued)
`
`Page
`
`
`I.
`
`MANDATORY NOTICES UNDER 37 C.F.R. § 42.8(b) ............................. 1
`
`A.
`
`Real Party In Interest ............................................................................ 1
`
`B.
`
`Related Matters ..................................................................................... 1
`
`C.
`
`Lead and Back-up Lead Counsel (§ 42.8(b)(3)) .................................. 2
`
`D.
`
`Service Information (§ 42.8(b)(4)) ....................................................... 2
`
`E.
`
`F.
`
`Power of Attorney (§ 42.10(b)) ............................................................ 2
`
`Proof of Service (§§ 42.6(e) and 42.105(a)) ........................................ 2
`
`II.
`
`COMPLIANCE WITH REQUIREMENTS FOR INTER PARTES
`REVIEW PETITION ...................................................................................... 3
`
`A. Grounds For Standing § 42.104(a) ....................................................... 3
`
`B.
`
`Fee For Inter Partes Review (§ 42.15(a)) ............................................. 3
`
`III. OVERVIEW OF CHALLENGE AND RELIEF REQUESTED ................... 4
`
`A.
`
`Prior Art Publications ........................................................................... 4
`
`B.
`
`Grounds for Challenge ......................................................................... 4
`
`IV. SUMMARY OF THE ’153 PATENT AND THE PROSECUTION
`HISTORY ....................................................................................................... 5
`
`A.
`
`Introduction .......................................................................................... 5
`
`B.
`
`Summary of the ’153 Patent ................................................................. 6
`
`C.
`
`Summary of Prosecution History ....................................................... 10
`
`V.
`
`CLAIM CONSTRUCTION ......................................................................... 11
`
`VI. THE NEWLY FOUND PRIOR ART .......................................................... 13
`
`A. Hancock .............................................................................................. 13
`
`29671-0024.0003/LEGAL28322641.1
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`-i-
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`

`

`TABLE OF CONTENTS
`(continued)
`
`Page
`
`
`
`B.
`
`Gordon ................................................................................................ 14
`
`VII. DETAILED EXPLANATION OF THE GROUNDS FOR
`UNPATENTABILITY OF CLAIMS 1–22 OF THE ’153 PATENT. ......... 16
`
`A.
`
`Claims 1–22 Are Unpatentable Under 35 U.S.C. § 103(a) as
`
`Obvious over the Admitted Prior Art in View of Hancock ............... 17
`
`1.
`
`2.
`
`3.
`
`Independent Claim 1 Is Unpatentable Under 35 U.S.C.
`§ 103(a) as Obvious over the Admitted Prior Art in View
`of Hancock ............................................................................... 20
`
`Independent Claim 9 Is Unpatentable Under 35 U.S.C.
`§ 103(a) as Obvious over the Admitted Prior Art in View
`of Hancock ............................................................................... 22
`
`Dependent Claims 2–8 and 10–22 Are Unpatentable
`Under 35 U.S.C. § 103(a) as Obvious over the Admitted
`Prior Art in View of Hancock .................................................. 26
`
`B.
`
`Claims 1-22 Are Unpatentable Under 35 U.S.C. § 103(a) as
`
`Obvious over the Admitted Prior Art in View of Gordon ................. 40
`
`1.
`
`2.
`
`3.
`
`Independent Claim 1 Is Unpatentable Under 35 U.S.C.
`§ 103(a) as Obvious over the Admitted Prior Art in View
`of Gordon ................................................................................. 41
`
`Independent Claim 9 Is Unpatentable Under 35 U.S.C.
`§ 103(a) as Obvious over the Admitted Prior Art in View
`of Gordon ................................................................................. 43
`
`Dependent Claims 2–8 and 10–22 Are Unpatentable
`Under 35 U.S.C. § 103(a) as Obvious over the Admitted
`Prior Art in View of Gordon .................................................... 46
`
`VIII. CONCLUSION ............................................................................................. 60
`
`29671-0024.0003/LEGAL28322641.1
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`-ii-
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`

`

`Petition for Inter Partes Review of U.S. Pat. No. 6,023,153
`
`I. MANDATORY NOTICES UNDER 37 C.F.R. § 42.8(b)
`
`A. Real Party In Interest
`
`QSC Audio Products, LLC (“QSC”), located at 1675 MacArthur Blvd.,
`
`Costa Mesa, CA 92626, is the real party in interest for this petition. No other
`
`entity is a real party of interest or a privy of QSC for this petition.
`
`B. Related Matters
`
`U.S. Patent No. 6,023,153 (“the ’153 patent” and attached as Exhibit 1001)
`
`and U.S. Patent 5,652,542 are being asserted against Petitioner in an on-going
`
`patent infringement lawsuit brought by Patent Owner in Crest Audio, Inc. v. QSC
`
`Audio Products, LLC 3:12-CV755-FKB, filed in the United States District Court
`
`for the Southern District of Mississippi, Jackson Division, on November 7, 2012
`
`and served on Petitioner on Nov. 19, 2012.
`
`U.S. Patent No. 5,652,544 is being asserted against Petitioner in a patent
`
`infringement lawsuit brought by Patent Owner in Crest Audio, Inc. v. QSC Audio
`
`Products, LLC 3:13CV610 DPJ-FKB, filed in the United States District Court for
`
`the Southern District of Mississippi Jackson Division on September 27, 2013 and
`
`served on Petitioner on Oct. 4, 2013.
`
`In the above litigation involving the ’153 patent, Petitioner is asserting, inter
`
`alia, that the claims of the ’153 patent are unpatentable. Rejection and cancellation
`
`of claims 1–22 of the ’153 patent will prevent Patent Owner from claiming
`
`29671-0024.0003/LEGAL28322641.1
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`

`

`Petition for Inter Partes Review of U.S. Pat. No. 6,023,153
`
`technologies that are in the public domain as its own and from asserting
`
`unpatentable claims against others.
`
`In addition to the current Petition, Petitioner is pursuing petitions for Inter
`
`Partes Review of U.S. Patent Nos. 5,652,542 and 5,652,544 that are also being
`
`asserted in the above-mentioned litigations.
`
`C. Lead and Back-up Lead Counsel (§ 42.8(b)(3))
`
`Lead Counsel
`Chun M. Ng
`Reg. No. 36,878
`CNg@perkinscoie.com
`(206)359-6488
`
`
`Back-up Counsel
`Rodney C. Tullett
`Reg. No. 34,034
`RTullett@perkinscoie.com
`(206)359-3304
`
`
`
`D.
`
`Service Information (§ 42.8(b)(4))
`
`Service may be made by mail or hand delivery to Perkins Coie LLP, 1201
`
`Third Ave, Suite 4900, Seattle, WA 98101. Contact numbers are: (206) 359-8000
`
`(tel) and (206) 359-9000 (fax). Electronic mail addresses are set forth above in
`
`Section I.C.
`
`E.
`
`Power of Attorney (§ 42.10(b))
`
`Pursuant to 37 C.F.R. § 42.10(b), this Petition is being filed with a Power of
`
`Attorney executed by Petitioner appointing the above-designated attorneys.
`
`F.
`
`Proof of Service (§§ 42.6(e) and 42.105(a))
`
`Proof of service of this Petition is provided in Appendix A.
`
`
`
`29671-0024.0003/LEGAL28322641.1
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`

`Petition for Inter Partes Review of U.S. Pat. No. 6,023,153
`
`II. COMPLIANCE WITH REQUIREMENTS FOR INTER PARTES
`REVIEW PETITION
`
`A. Grounds For Standing (§ 42.104(a))
`
`Pursuant to 37 C.F.R. § 42.104(a), Petitioner hereby certifies that the ’153
`
`patent is available for Inter Partes Review and that the Petitioner is not barred or
`
`estopped from requesting Inter Partes Review challenging claims 1–22 of the ’153
`
`patent on the grounds identified herein.
`
`Neither Petitioner, nor any party in privity with Petitioner: (i) has filed a
`
`civil action challenging the validity of claims 1–22 of the ’153 patent; or (ii) has
`
`been served with a complaint alleging infringement of the ’153 patent, more than a
`
`year prior to the date of filing of this Petition. Also, claims 1–22 of the ’153 patent
`
`have not been the subject of a finally concluded district court litigation involving
`
`the Petitioner. Finally, this Petition is being filed more than nine months after the
`
`issue date of the ’153 patent.
`
`B.
`
`Fee For Inter Partes Review (§ 42.15(a))
`
`The Commissioner is authorized to charge the fee specified by 37 C.F.R.
`
`§ 42.15(a), and any other fee required from Petitioner in connection with this
`
`petition, to Deposit Account No. 50-0665 with charge reference number
`
`029671-0024.0003.
`
`
`
`29671-0024.0003/LEGAL28322641.1
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`

`

`Petition for Inter Partes Review of U.S. Pat. No. 6,023,153
`
`III. OVERVIEW OF CHALLENGE AND RELIEF REQUESTED
`
`Pursuant to Rules 42.22(a)(1) and 42.104(b)(1)–(2), Petitioner challenges
`
`claims 1–22 of the ’153 patent as unpatentable under 35 U.S.C. § 103(a).
`
`Petitioner requests that a trial for Inter Partes Review of the ’153 Patent be
`
`instituted and that claims 1–22 be canceled.
`
`A.
`
`Prior Art Publications
`
`Petitioner relies upon, in addition to the admitted prior art (“APA”) as
`
`detailed in the ’153 patent itself, the following prior art printed publications:
`
`1. Hancock, Jon, A Class D Amplifier Using MOSFETs with Reduced
`
`Minority Carrier Lifetime, Audio Engineering Society Preprint 2958 (E-5) (1990),
`
`(“Hancock” and attached as Exhibit 1002). The Hancock paper was published in
`
`1990 and is prior art to the ’153 patent under at least § 102(b).
`
`2.
`
`Gordon, Jay, The Characteristics of Conventional and Switching
`
`Power Supplies in Analog Signal Processing, Audio Engineering Society Preprint
`
`3889 (G-5) (1994), (“Gordon” and attached as Exhibit 1003). The Gordon paper
`
`was published in 1994 and is prior art to the ’153 patent under at least § 102(b).
`
`B. Grounds for Challenge
`
`1)
`
`Claims 1–22 are unpatentable under 35 U.S.C. § 103(a) as obvious
`
`over the APA in view of the Hancock paper.
`
`2)
`
`Claims 1–22 are unpatentable under 35 U.S.C. § 103(a) as obvious
`
`over the APA in view of the Gordon paper.
`
`29671-0024.0003/LEGAL28322641.1
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`

`

`Petition for Inter Partes Review of U.S. Pat. No. 6,023,153
`
`This Petition, supported by a declaration of Professor Enrico Santi
`
`(“Declaration of Santi” and attached as Exhibit 1004) filed herewith, demonstrates
`
`that there is a reasonable likelihood that Petitioner will prevail with respect to at
`
`least one of the challenged claims and that the challenged claims are unpatentable
`
`for the reasons cited in this Petition. See 35 U.S.C. § 314(a).
`
`
`
`IV. SUMMARY OF THE ’153 PATENT AND THE PROSECUTION
`HISTORY
`
`A.
`
`Introduction
`
`The ’153 patent should not have been issued. Had the Examiner been aware
`
`of the two newly cited references, the Examiner would have no doubt rejected all
`
`of the claims as being obvious over the APA in combination with either Hancock
`
`or Gordon.
`
`The specification of the ’153 patent states that switched mode power
`
`regulators were commonly used in audio amplifiers. The specification also admits
`
`that power factor correction circuits using “boost” architecture were well known in
`
`the art. The sole rationale proffered by Patent Owner for patentability was that it
`
`would have been unobvious to combine a power factor correction circuit with a
`
`switching power supply in the context of an audio amplifier. Thus, the issue
`
`presented by this Petition is clear and simple:
`
`29671-0024.0003/LEGAL28322641.1
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`Petition for Inter Partes Review of U.S. Pat. No. 6,023,153
`
`• Was it obvious to a person of ordinary skill in the art at the time of the
`
`claimed invention of the ’153 patent to combine a power factor
`
`correction circuit with a switching power supply in an audio amplifier?
`
`As will be seen below, not only was it obvious to make such a combination,
`
`but two separate prior art papers presented years earlier at the premier technical
`
`conference for audio engineering explicitly stated the benefits of making exactly
`
`that combination.
`
`B.
`
`Summary of the ’153 Patent
`
`The ’153 patent describes an audio amplifier that includes a power factor
`
`correction circuit. As explained in the ’153 patent, Ex. 1001 at col. 1, lines 33–50
`
`and col. 2, lines 38–50, conventional power supplies used for audio amplifiers
`
`typically use an AC line transformer, followed by a diode rectifier and a filter
`
`capacitor, as shown in Figure 1 of the ’153 patent. As a result, these power
`
`supplies suffer from several disadvantages. First, AC transformers are large and
`
`heavy. In addition, the current flowing into a conventional power supply, or into a
`
`switching power supply without a power factor correction circuit, has relatively
`
`high peaks and does not correspond to the wave shape of the voltage on the AC
`
`line, which causes distortion and harmonics on the AC line. Therefore, according
`
`to the ’153 patent, there was a need for an audio amplifier capable of drawing
`
`29671-0024.0003/LEGAL28322641.1
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`

`Petition for Inter Partes Review of U.S. Pat. No. 6,023,153
`
`current from an AC line that closely follows the wave shape of the voltage on the
`
`AC line. See Id. at col. 2, lines 50–56.
`
`The solution, according to the ’153 patent, is to include a power factor
`
`correction circuit in the audio amplifier power supply. As discussed at col. 3, lines
`
`45–48, “an important feature of the instant invention is the use of a power factor
`
`correction circuit 30 in combination with the power supply 11 in an audio
`
`amplifier.” The only embodiment shown of the power factor correction circuit 30
`
`is the use of an inductor and a switch arranged in a boost configuration. See also
`
`Declaration of Santi, Ex. 1004 at 2–3, ¶¶ 6–7.
`
`The ’153 patent specification states that a boost configured power factor
`
`correction circuit is well known in the art. See Ex. 1001 at col. 3, lines 55–61 (“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 . . . .”); See also Declaration of Santi, Ex. 1004 at 11, ¶ 26.
`
`The power factor correction circuit includes:
`
`a control circuit (preferably a closed loop control, not
`
`shown) which is adapted to turn on and off the switch 32
`
`at a relatively high frequency (for example 70 KHz) as
`
`compared to the frequency on the AC line 12 such that
`
`the wave shape of the average current drawn into the
`
`power factor correction circuit 30 closely follows the
`
`wave shape of the voltage across the AC line.
`
`29671-0024.0003/LEGAL28322641.1
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`

`

`Petition for Inter Partes Review of U.S. Pat. No. 6,023,153
`
`See Ex. 1001 at col. 4, lines 5–13. This type of power factor correction circuit that
`
`includes a control circuit for turning on and off the switch 32 was common well
`
`prior to 1996. See Declaration of Santi, Ex. 1004 at 11, ¶ 28.
`
`The ’153 patent specification also describes a switching power supply (See
`
`Ex. 1001 at col. 2, lines 11–25) that includes a switch 24 and a high frequency
`
`transformer 15. The patent states that:
`
`Typically, there is a closed loop control system which
`
`senses the voltage on the secondary of the high frequency
`
`transformer 15 and uses the sensed voltage to control the
`
`switch 24. More particularly, the switch 24 is controlled
`
`to produce a pulse width modulated signal on the
`
`secondary winding of the transformer 15. As is known in
`
`the art, the switch 24 is turned on and off at a relatively
`
`high frequency (for example, 70 KHz) as compared to
`
`the frequency of the voltage on the AC line 12 such that
`
`very efficient conversion of the DC voltage level across
`
`filter capacitor 17 to a lower DC voltage across filter
`
`capacitor 18' is obtained.
`
`Id. at col. 2, lines 11–21.
`
`Patent Owner further unambiguously writes in the ’153 patent:
`
`It is preferred that the switching power supply 11 be a
`
`resonant switching power supply, the details of which
`
`are known in the art.
`
`29671-0024.0003/LEGAL28322641.1
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`

`

`Petition for Inter Partes Review of U.S. Pat. No. 6,023,153
`
`Id. at col. 3, lines 42–44 (emphasis added).
`
`A switching power supply, as described in the ’153 patent, is referred to in
`
`many different ways by those skilled in the art, including switched-mode power
`
`supply, switch mode power regulator, pulse width modulated power supply, etc.
`
`See Declaration of Santi, Ex. 1004 at 12, ¶ 31. One defining feature of these types
`
`of power supplies is that they use one or more switches that turn off and on at a
`
`relatively high frequency. See Id.
`
`Figure 4 of the ’153 patent shows an amplifier design that combines the
`
`prior art switching power supply 11 with the prior art power factor correction
`
`circuit 30 to drive a power amplifier 20 and speaker 22.1
`
`
`In other words, Patent Owner admits that the switching power supply 11 is
`
`well known in the art and the power factor correction circuit 30 in boost
`
`
`
` 1
`
` This is the only embodiment of the claimed invention described in the ’153 patent. Professor
`Santi notes that Figure 4 contains errors. See Declaration of Santi, Ex. 1004 at 3, ¶ 7.
`
`29671-0024.0003/LEGAL28322641.1
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`Petition for Inter Partes Review of U.S. Pat. No. 6,023,153
`
`configuration is well known in the art. The only alleged inventive contribution is
`
`the combination of a well-known power factor correction circuit with a switching
`
`power supply in an audio amplifier.
`
`C.
`
`Summary of Prosecution History2
`
`The application that became the ’153 patent was filed on Sept. 10, 1998,
`
`claiming the benefit of a provisional patent application filed on Sept. 23, 1997.
`
`Both the utility and provisional applications were filed with Dennis Fink as the
`
`sole named inventor.
`
`A first Office Action was mailed from the U.S. Patent Office on May 12,
`
`1999, in which claims 1 and 9 were rejected as being anticipated by U.S. Patent
`
`No. 3,992,585 to Turner. Claims 2, 5–7, 10–13, 16 and 19–21 were rejected as
`
`being obvious over Turner in view of U.S. Patent No. 5,502,630 to Rokhvarg.
`
`Finally, claims 3, 4, 8, 14, 15, 17, 18 and 22 were rejected as being obvious over
`
`Turner.
`
`A response was filed on August 16, 1999, pointing out that the Turner patent
`
`did not disclose the use of a power factor correction circuit in an audio amplifier.
`
`With respect to the rejection of the claims as obvious over Turner in view of
`
`Rokhvarg, Patent Owner argued that obviousness can be established only when the
`
`
`
` A copy of the prosecution history is attached as Exhibit 1006.
`
` 2
`
`29671-0024.0003/LEGAL28322641.1
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`

`Petition for Inter Partes Review of U.S. Pat. No. 6,023,153
`
`teachings of the prior art provide a suggestion or incentive to support a
`
`combination. In particular, Patent Owner argued:
`
`Here, neither the Turner nor Rokhvarg references supply
`
`motivation to modify the amplifier 14 of the Turner
`
`reference with the power factor correction circuit of the
`
`Rokhvarg reference. . . . .
`
`Applicant submits that the Examiner has merely cited
`
`references which contain pieces of the claimed invention
`
`and used the teachings of the instant application to
`
`provide the motivation to modify an audio amplifier
`
`with a power factor correction circuit. This hindsight
`
`reconstruction is clearly improper.
`
`Response pages 3–4, Ex. 1006 at 55–56 (emphasis added). A notice of allowance
`
`was mailed on Sept. 13, 1999, and the ’153 patent issued on Feb. 8, 2000.
`
`
`
`V. CLAIM CONSTRUCTION
`
`A claim subject to Inter Partes Review shall be given by the Patent Office
`
`“its broadest reasonable construction in light of the specification of the patent in
`
`which it appears” to one of ordinary skill in the art. 37 C.F.R. §§ 42.100(b) and
`
`42.104(b)(3).
`
`29671-0024.0003/LEGAL28322641.1
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`

`Petition for Inter Partes Review of U.S. Pat. No. 6,023,153
`
`Petitioner proposes construction of certain claim terms below pursuant to the
`
`broadest reasonable construction standard (abbreviated “BRC” below). 3 The
`
`proposed claim constructions are offered only to comply with 37 C.F.R.
`
`§§ 42.100(b) and 42.104(b)(3) and for the sole purpose of this Petition, and thus do
`
`not necessarily reflect appropriate claim constructions to be used in the concurrent
`
`litigation and other proceedings where a different claim construction standard
`
`applies.
`
`Term
`“regulated DC source of
`power”
`
`“switching transistor and
`inductor configured in a
`boost arrangement”
`
`“resonant switching
`power supply”
`
`“intermediate source of
`voltage”
`
`
`
`BRC
`A source of DC power
`that attempts to maintain
`an output voltage or
`current.
`A transistor and an
`inductor configured so
`that the output voltage is
`greater than the input
`voltage.
`A power supply circuit
`that includes a resonant
`circuit that causes the
`output to depend on the
`switching frequency.
`A voltage supply at a
`point between two circuit
`components.
`
`Evidence
`’153 patent, Ex. 1001 at
`col. 2, lines 11–23, col. 3,
`lines 3–5, col. 4, lines 13–
`21, and col. 4, lines 48–60
`’153 patent, Ex. 1001 at
`Fig. 4 and col. 3, line 47–
`col 4, line 1
`
`’153 patent, Ex. 1001 at
`col. 3, lines 41–43
`
`
`
`’153 patent, Ex. 1001 at
`Fig. 4, col. 2, line 26, col.
`3, line 62–col 4, line 4,
`
` 3
`
` Because of the extent of the APA set forth in the ’153 patent, it is Petitioner’s position that
`much of the specific claim language may not require interpretation. The issue in this proceeding
`is not primarily to decide whether or not certain claim limitations are present in the prior art
`(because all elements have been admitted to be in the prior art), but rather whether or not it
`would have been obvious to combine these elements. Nevertheless, select terms are presented
`with proposed constructions.
`
`29671-0024.0003/LEGAL28322641.1
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`

`Petition for Inter Partes Review of U.S. Pat. No. 6,023,153
`
`Term
`
`BRC
`
`Evidence
`and col. 4, line 61–col. 5,
`line 3
`
`
`The remaining terms in the claims are to be given their broadest reasonable
`
`interpretation in light of the specification as commonly understood by those of
`
`ordinary skill in the art.
`
`In addition to the above interpretations, the PTAB should be aware of the
`
`proposed claim constructions proposed by Patent Owner in the concurrent
`
`litigation. A copy of the parties’ Joint Claim Construction and Prehearing
`
`Statement is attached as Exhibit 1005.
`
`VI. THE NEWLY FOUND PRIOR ART
`
`A. Hancock
`
`The Hancock paper was presented at the 89th Convention of the Audio
`
`Engineering Society4 held in Los Angeles in 1990. The Hancock paper presents a
`
`discussion of Class D amplifiers and their applications, including audio
`
`applications. 5 A Class D amplifier is one that uses transistor switches to
`
`implement an amplifier. See Declaration of Santi, Ex. 1004 at 4–6, ¶¶ 11–13.
`
`
`
` 4
`
` The Audio Engineering Society is the only professional society devoted exclusively to audio
`technology with over 14,000 members worldwide. See http://www.aes.org/ .
`5 The Hancock paper at page 6 indicates that such power supplies can be used in audio
`applications. Indeed, the Hancock paper was presented at a technical conference for audio
`engineers. See Declaration of Santi, Ex. 1004 at 5–6, ¶¶ 12–13.
`
`29671-0024.0003/LEGAL28322641.1
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`Petition for Inter Partes Review of U.S. Pat. No. 6,023,153
`
`Hancock explicitly recognized the importance of power factor correction in
`
`switching power supplies for amplifiers, stating:
`
`In power supply applications . . . power factor has long
`
`been a concern and specified parameter. Of late it is
`
`receiving more attention for industrial and consumer
`
`equipment, particularly in Europe, where new IEC
`
`standards classify non-power factor corrected equipment
`
`with waveforms like Fig. 27 as Class D equipment, with
`
`attendant penalties and restrictions.
`
`One method gaining popularity to solve this problem is
`
`the use of a switching converter as a current pre-regulator
`
`to program the current draw to follow the line voltage.
`
`Typically a boost or flyback converter is used as a pre-
`
`regulator to charge a 360 V bus, which powers a
`
`secondary converter that provides isolation and load
`
`regulation.
`
`Hancock, Ex. 1002 at page 6 (emphasis added).
`
`The Hancock paper was not considered by the Examiner during the initial
`
`prosecution of the ’153 patent.
`
`B. Gordon
`
`The Gordon paper was also presented to the Audio Engineering Society, at
`
`their conference in San Francisco in 1994. The Gordon paper provides a survey of
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`Petition for Inter Partes Review of U.S. Pat. No. 6,023,153
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`switching power supplies and their characteristics in audio applications. See
`
`Gordon, Abstract, Ex. 1003 at 1; Declaration of Santi, Ex. 1004 at 8, ¶¶ 19–20.
`
`Gordon describes a generic power supply with a transformer, a rectifier, and
`
`an output filter. See Gordon, Introduction, Ex. 1003 at 1 and Figure 1 (reproduced
`
`below).
`
`
`
`Gordon talks extensively about power factor correction in the context of
`
`audio amplifiers. At page 10, Gordon details the drawbacks of poor power factor
`
`and shows that it is important and advantageous to include power factor correction
`
`circuitry in a switching power supply. Specifically, Gordon states:
`
`A look at the typical switching supply revealed some
`
`shared drawbacks with the conventional supply. . . . The
`
`power factor is low, and input current harmonics are
`
`high.
`
` Figure 17 is an outline schematic of the
`
`transformer section of Figure 16 that shows how the
`
`boost and buck topologies can be combined to alleviate
`
`these problems. . . . The boost converter is used to
`
`correct the power factor by controlling Iin to be
`
`proportional to the Vin.
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`Petition for Inter Partes Review of U.S. Pat. No. 6,023,153
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`
`Id. at 10 (emphasis added); see Declaration of Santi, Ex. 1004 at 10, ¶ 24.
`
`The Gordon paper was not considered by the Examiner during the initial
`
`prosecution of the ’153 patent.
`
`
`
`VII. DETAILED EXPLANATION OF THE GROUNDS FOR
`
`UNPATENTABILITY OF CLAIMS 1–22 OF THE ’153 PATENT.
`
`For the purposes of the ’153 patent, Petitioner submits that a person of
`
`ordinary skill in the art would be an electronics engineer with at least a Bachelor of
`
`Science degree in electrical or electronics engineering or equivalent studies and
`
`several years of experience designing or studying power supplies. See Declaration
`
`of Santi, Ex. 1004 at 3–4, ¶ 8.
`
`The scope and content of the prior art indicates that it was well known to
`
`persons of ordinary skill in the art prior to the effective filing date of the ’153
`
`patent to include a power factor correction circuit in a switching power supply for
`
`an audio amplifier. See Id. at 4, ¶ 9.
`
`As discussed above, at least two prior art references discuss the desirability
`
`of including a power factor correction circuit in a switching power supply for an
`
`amplifier. See Id. at 4, ¶ 10. These references were not considered by the
`
`Examiner who initially reviewed the application that became the ’153 patent. In
`
`addition, these references are much more relevant to the patentability of the claims
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`Petition for Inter Partes Review of U.S. Pat. No. 6,023,153
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`that were allowed than the references that were actually considered by the
`
`Examiner.
`
`A. Claims 1–22 Are Unpatentable Under 35 U.S.C. § 103(a) as
`Obvious over the Admitted Prior Art in View of Hancock
`
`The argument presented here is simple. Every element of the claims is
`
`already admitted as prior art by Patent Owner. Comparing Figure 2 of the ’153
`
`patent (labeled as prior art) with Figure 4 of the ’153 patent (reproduced below), it
`
`is immediately evident that the only thing that is added in Figure 4 is a power
`
`factor correction circuit.
`
`
`
`
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`Petition for Inter Partes Review of U.S. Pat. No. 6,023,153
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`The ’153 patent shows explicitly in Figure 4 that the prior art is simply
`
`modified by adding a boost circuit at the front of a prior art switching power
`
`supply 11. In addition, the boost circuit 30 is also admitted as being known. See
`
`Ex. 1001 at col. 3, lines 55–61 (“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.”)
`
`The Hancock paper was presented about seven years prior to the earliest
`
`claimed priority date of the ’153 patent. Like the ’153 patent, pages 5–6 of the
`
`Hancock paper discuss the problems with power supplies that use 50/60 Hz
`
`transformers and capacitor input filters. See Declaration of Santi, Ex. 1004 at 6,
`
`¶ 14. The paper indicates that in such power supplies, the input current flows in
`
`relatively narrow spikes, resulting in high harmonic content and high peak currents
`
`in proportion to the true power consumed. See Id.
`
`Figure 27 of the Hancock paper (reproduced below left) shows the same
`
`current spike that is shown in Figure 5 of the ’153 patent (reproduced below right).
`
`Thus, the problem addressed by the ’153 patent was previously well known in the
`
`art as exemplified by Hancock. See Declaration of Santi, Ex. 1004 at 6–7, ¶ 15.
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`Petition for Inter Partes Review of U.S. Pat. No. 6,023,153
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`The solution to this problem as discussed in the Hancock paper is to “use . . .
`
`
`
`
`
`a switching converter as a current pre-regulator to program the current draw to
`
`follow the line voltage.” Hancock, Ex. 1002 at 6. The paper states that “typically
`
`a boost or flyback converter is used as a pre-regulator to charge a 360 V bus, which
`
`powers a secondary converter that provides isolation and load regulation.” Id.
`
`This is precisely the claimed invention.
`
`Hancock’s Figure 28 (reproduced below) shows the operation of the
`
`switching converter, which is also referred to as a power factor converter (e.g., a
`
`power factor correction circuit). The graph shows how the current waveform
`
`tracks the input voltage waveform with the power factor correction circuit in place.
`
`See Declaration of Santi, Ex. 1004 at 8, ¶ 17. This is the same solution that is
`
`disclosed in the ’153 patent. Id. at 8, ¶ 18.
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`Petition for Inter Partes Review of U.S. Pat. No. 6,023,153
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`
`
`
`
`1.
`
`Independent Claim 1 Is Unpatentable Under 35 U.S.C. § 103(a)
`as Obvious over the Admitted Prior Art in View of Hancock
`
`Comparing the APA and the Hancock paper to claim 1 of the ’153 patent,
`
`each element of claim 1 is explicitly or inherently disclosed in the APA and
`
`Hancock, and Hancock provides the motivation to make the claimed combination
`
`to improve the power factor. See Declaration of Santi, Ex. 1004 at 15, ¶¶ 39–40.
`
`Claim 1
`
`APA and Hancock paper
`
`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:
`
`The APA at Figure 2 shows a prior art audio
`amplifier driving a speaker load with an AC source
`input. See Ex. 1001 at Fig. 2; Declaration of Santi,
`Ex. 1004 at 15, ¶ 42.
`Hancock also discloses a class D amplifier for
`delivering audio output. See Declaration of Santi, Ex.
`1004 at 5, ¶¶ 12–13 and 16, ¶ 43. The amplifier
`draws input current and a sinusoidal line voltage from
`an AC source. See Id. and Hancock, Ex. 1002 at
`Figure 28.
`
`
`a power factor
`correction circuit for
`receiving the line
`voltage from the AC
`source, the power
`
`The APA at col. 3, lines 55–61 states: “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.” See Declaration of Santi, Ex. 1004
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`Petition for Inter Partes Review of U.S. Pat. No. 6,023,153
`
`Claim 1
`
`APA and Hancock paper
`
`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