Trials@uspto.gov
`571-272-7822
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` Paper 40
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` Date: March 17, 2020
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`UNITED STATES PATENT AND TRADEMARK OFFICE
`____________
`
`BEFORE THE PATENT TRIAL AND APPEAL BOARD
`____________
`
`APPLE INC.,
`Petitioner,
`
`v.
`
`QUALCOMM, INC.,
`Patent Owner.
`_______________
`
`IPR2018-01452
`Patent 7,834,591 B2
`
`____________
`
`
`Before TREVOR M. JEFFERSON, DANIEL J. GALLIGAN, and
`SCOTT B. HOWARD, Administrative Patent Judges.
`
`JEFFERSON, Administrative Patent Judge.
`
`
`JUDGMENT
`Final Written Decision
`Determining All Challenged Claims Unpatentable
`Denying Patent Owner’s Motion to Exclude
`35 U.S.C. § 318(a)
`
`
`
`
`
`

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`IPR2018-01452
`Patent 7,834,591 B2
`
`I.
`INTRODUCTION
`In this inter partes review, Apple Inc. (“Petitioner”) challenges claims
`1–5, 7, 8, 10–13, 15, 17, 18, 21, 23, 24, 28, 30–32, 37, 39–41, and 44 of U.S.
`Patent No. 7,834,591 B2 (“the ’591 patent,” Ex. 1001) which is assigned to
`Qualcomm Incorporated (“Patent Owner”). Paper 2 (“Petition” or “Pet.”).
`We have jurisdiction under 35 U.S.C. § 6. This Final Written
`Decision, issued pursuant to 35 U.S.C. § 318(a), addresses issues and
`arguments raised during the trial in these inter partes reviews. For the
`reasons discussed below, we determine that Petitioner has demonstrated the
`unpatentability of claims 1–5, 7, 8, 10–13, 15, 17, 18, 21, 23, 24, 28, 30–32,
`37, 39–41, and 44.
`
`A. Procedural History
`Petitioner filed a Petition challenging claims 1–5, 7, 8, 10–13, 15, 17,
`18, 21, 23, 24, 28, 30–32, 37, 39–41, and 44 of the ’591 patent (Pet. 3–4),
`and Patent Owner filed a Preliminary Response (Paper 6). We instituted
`trial on all grounds of unpatentability. Paper 7 (“Dec. on Inst.”), 26. During
`trial, Patent Owner filed a Response (Paper 20, “PO Resp.”), Petitioner filed
`a Reply (Paper 25, “Pet. Reply”), and Patent Owner filed a Sur-reply (Paper
`32, “PO Sur-reply”). Patent Owner filed a Motion to Exclude (Paper 33), to
`which Petitioner filed an Opposition (Paper 34), and Patent Owner replied
`(Paper 36). A combined oral hearing for this inter partes review and
`IPR2018-01283 was held on December 13, 2019, a transcript of which
`appears in the record in each case. Paper 39.
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`Patent 7,834,591 B2
`B. Instituted Grounds of Unpatentability
`We instituted inter partes review of claims 1–5, 7, 8, 10–13, 15, 17,
`18, 21, 23, 24, 28, 30–32, 37, 39–41, and 44 of the ’591 patent on the
`following grounds:
`Claims Challenged
`1–5, 7, 8, 10-12, 15,
`18, 21, 23, 24, 28, 30–
`32 37, 39–41, 44
`4, 5, 13, 17
`
`35 U.S.C. §
`103(a)1
`
`References
`Bell,2 Kester,3 Gong,4
`Martin5
`
`103(a)
`
`Bell, Kester, Gong, Martin,
`Hatular6
`
`Dec. on Inst. 6–7, 26; see Pet. 3–4.
`Petitioner relies on the Declaration of Dr. Joshua Phinney (Ex. 1003
`and the Supplemental Declaration of Dr. Joshua Phinney (Ex. 1056). Patent
`Owner relies on the Declaration of Pradeep Lall, Ph.D. (Ex. 2007).
`
`C. Related Proceedings
`The parties inform us that the ’591 patent was asserted against
`Petitioner in the proceeding Qualcomm Inc. v. Apple Inc., Case No. 3:17-cv-
`2402 (S.D. Cal.), which has since been dismissed. Pet. 99; Paper 4, 1
`
`
`1 The Leahy-Smith America Invents Act (“AIA”) included revisions to
`35 U.S.C. §§ 102, 103 that became effective on March 16, 2013. Because
`the ’591 patent issued from an application filed before March 16, 2013, we
`apply the pre-AIA versions of the statutory bases for unpatentability.
`2 U.S. Patent No. 5,723,970, issued March 3, 1998 (Ex. 1005, “Bell”).
`3 Walt Kester, Ed., PRACTICAL DESIGN TECHNIQUES FOR POWER AND
`THERMAL MANAGEMENT, Analog Devices, 1998 (Ex. 1007, “Kester”).
`4 U.S. Patent No. 5,998,972, issued Dec. 7, 1999 (Ex. 1008, “Gong”).
`5 U.S. Patent Application Publication No. 2007/0029975 A1, published Feb.
`8, 2007 (Ex. 1006, “Martin”).
`6 U.S. Patent No. 6,184,660 B1, issued Feb. 6, 2001 (Ex. 1021, “Hatular”).
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`(Patent Owner’s Mandatory Notices); Paper 18, 1 (Petitioner’s Updated
`Mandatory Notices). Various claims of the ’591 patent also are at issue in
`related inter partes reviews IPR2018-01283. Pet. 99; see also Paper 4, 1.
`
`D. The ’591 Patent and Illustrative Claims
`The ’591 patent is titled, “Switching Battery Charging Systems and
`Methods” and discloses “[t]echniques for charging a battery using a
`switching regulator.” Ex. 1001, code (54), (57). The ’591 patent discloses
`that “embodiments [of the invention] include switching battery chargers that
`modify the battery current based on sensed circuit conditions such as battery
`voltage or input current to the switching regulator.” Id. at 1:67–2:3. The
`’591 patent discloses that
`[i]n one embodiment, the present invention includes a Universal
`Serial Bus (USB) battery charger comprising a switching
`regulator having at least one switching transistor, the switching
`transistor having first input and a first output, wherein the first
`input of the switching transistor is coupled to a USB power
`source, a filter having a first input and a first output, wherein the
`first input of the filter is coupled to the first output of the
`switching transistor, and a battery coupled to the first output of
`the filter, wherein the switching regulator is configured to receive
`a USB voltage, and in accordance therewith, generate a
`switching signal to the control terminal of the switching
`transistor, and wherein a switching current and switching voltage
`at the output of the switching transistor are coupled through the
`filter to generate a filtered current and a filtered voltage to charge
`the battery.
`Id. at 2:4–18.
`Figure 10A of the ’591 patent, shown below, illustrates charging a
`battery using a switching regulator in accordance with an embodiment of the
`invention. Id. at 18:64–66.
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`Patent 7,834,591 B2
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`
`
`Figure 10A of the ’591 patent shows current on the right vertical axis
`(“Current (A)”) and voltage on the battery on the left vertical axis (“Battery
`Voltage (V)”) versus time. Id. at 18:66–19:1. Battery voltage is shown by
`line 1001, current into the battery by line 1002, and current into the
`switching regulator by the line 1003. Id. at 19:1–4. The ’591 patent
`specifies two modes, current control mode and voltage control mode. Id. at
`19:6–7. Specifically, the ’591 patent describes that
`[t]his example [in Figure 10A] illustrates a charge cycle for
`charging a deeply depleted Li+ battery. The battery is charged
`in two basic modes: a current control mode (t=0, t2) and a voltage
`control mode (t=t2, t3). In this example, the voltage on the
`battery is initially below some particular threshold (e.g., 3 volts),
`indicating that the battery is deeply depleted. Accordingly, the
`current control mode may initially generate a constant precharge
`current 1010 (e.g., 100 mA). The constant precharge current
`1010 will cause the battery voltage to start to increase. When the
`battery voltage increases above a precharge threshold 1020 (e.g.,
`3 volts), the system will increase the current sourced to the
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`battery. The second current is sometimes referred to as the “fast
`charge” current.
`Id. at 19:4–17. The ’591 patent discloses that Figure 10A shows “the current
`into the battery may be larger than the current received by the switching
`regulator” and that “[a]s the battery voltage increases [during the charge
`process], the current into the battery may be reduced so that the input current
`remains approximately constant.” Id. at 19:18–26. Thus, the ’591 patent
`discloses, “if the voltage on the battery increases, and if the current supplied
`by the switching regulator remains constant, the current into the switching
`regulator will begin to increase.” Id. at 19:26–28.
`Claims 1, 8, and 32 are independent claims. Claim 1 (an apparatus)
`and claim 8 (a method) are illustrative and reproduced below (Ex. 1001,
`25:41–61, 26:25–39 (bracketed lettering added)).
`1.
`[a] A Universal Serial Bus (USB) battery charger
`comprising:
`[b] a switching regulator having at least one
`switching transistor, the switching transistor having a first
`input and a first output, wherein the first input of the
`switching transistor is coupled to a USB power source; and
`[c] a filter having a first input and a first output,
`wherein the first input of the filter is coupled to the first
`output of the switching transistor;
`[d] wherein the switching regulator is configured to
`receive a USB voltage, and generate a switching signal to
`a control terminal of the switching transistor, and
`[e] wherein a switching current and a switching voltage at
`the output of the switching transistor are coupled through
`the filter to a battery to generate a filtered current and a
`filtered voltage to charge the battery, wherein the battery
`is coupled to the first output of the filter,
`[f] wherein the filtered current is greater than a first
`input current into the first input of the switching transistor,
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`and [g] the filtered current is reduced, in a current control
`mode, as a voltage on the battery increases.
`
`[a] A method of charging a battery from a Universal
`8.
`Serial Bus (USB) port comprising:
`[b] receiving a first input voltage and a first input
`current at an input of a switching regulator from a USB
`power source;
`[c] coupling a switching output voltage and current
`from the switching regulator through a filter to a terminal
`of a battery; and
`
`[d] generating a first output voltage and a first
`output current at the terminal of the battery;
`[e] wherein the first input voltage is greater than the
`first output voltage on the battery, [f] the first output
`current to the battery is greater than the first input current,
`and [g] wherein the first output current is reduced, in a
`current control mode, as the first output voltage on the
`battery increases.
`Ex. 1001, 25:41–61, 26:25–39.
`
`II. ANALYSIS
`
`A. Level of Ordinary Skill in the Art
`The Petition states that the person of ordinary skill in the art related to
`the ’591 patent at the time of filing “would have had at least a Bachelor’s
`Degree in Electrical Engineering and at least five years of experience in the
`field of power electronics. Additional education can compensate for less
`work experience, and vice versa.” Pet. 4 (citing Ex. 1003 ¶ 18).
`Patent Owner asserts that:
`A person of ordinary skill in the art (a “POSITA”) relevant to the
`’591 Patent at the time of its invention would have had (a) a
`Bachelor’s of science degree in an engineering discipline or
`physics, or a closely-related field, and at least two years of work
`or research experience in the field of circuit design, or (b) a
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`Patent 7,834,591 B2
`Master’s of science degree in an engineering discipline or
`physics, or a closely-related field, and at least one year of work
`or research experience in that same field. EX2007, ¶32. More
`work experience could compensate for less education, and vice
`versa. Id.
`PO Resp. 4.
`The parties do not materially dispute the level of ordinary skill in the
`art, differing in relevant experience and the types of technical degrees. See
`PO Resp. 4; Ex. 1003 ¶ 18. Our Institution Decision adopted Petitioner’s
`proposed level of skill in the art with the exception of the “at least”
`qualification. Dec. on Inst. 11. Neither party indicates whether the
`differences in level of skill affect their prior art contentions.
`On the full record, we adopt Petitioner’s definition of the level of
`ordinary skill in the art with the exception of the “at least” qualification
`because it is commensurate with the level of skill reflected in the ’591 patent
`and prior art references of record. See In re GPAC Inc., 57 F.3d 1573, 1579
`(Fed. Cir. 1995).
`
`B. Claim Interpretation
`In an inter partes review for a petition filed before November 13,
`2018, a claim in an unexpired patent shall be given its broadest reasonable
`construction in light of the specification of the patent in which it appears.
`37 C.F.R. § 42.100(b) (2018); see Changes to the Claim Construction
`Standard for Interpreting Claims in Trial Proceedings Before the Patent Trial
`and Appeal Board, 83 Fed. Reg. 51,340 (Oct. 11, 2018) (amending
`37 C.F.R. § 42.100(b); effective November 13, 2018). The Petition was
`accorded a filing date of July 27, 2018, and therefore, the broadest
`reasonable interpretation standard for claim interpretation applies. See
`Paper 5 (Notice of Filing Date Accorded to Petition). In applying a broadest
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`reasonable interpretation, claim terms generally 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. See In re Translogic Tech., Inc.,
`504 F.3d 1249, 1257 (Fed. Cir. 2007). This presumption may be rebutted
`when a patentee, acting as a lexicographer, sets forth an alternate definition
`of a term in the specification with reasonable clarity, deliberateness, and
`precision. In re Paulsen, 30 F.3d 1475, 1480 (Fed. Cir. 1994).
`1. “coupled to” and “coupled”
`Petitioner asserts proposed plain meaning constructions for “coupled
`to” (claims 1–7, 13–45) and “coupling” (claims 8–12, 25–31). Pet. 5.
`Patent Owner does not contest these constructions. PO Resp. 15–19. Based
`on the full record, the terms “coupled to” and “coupling” are not in
`controversy and their plain meaning requires no further construction. See,
`e.g., Nidec Motor Corp. v. Zhongshan Broad Ocean Motor Co., 868 F.3d
`1013, 1017 (Fed. Cir. 2017) (“[W]e need only construe terms ‘that are in
`controversy, and only to the extent necessary to resolve the controversy’ . . .
`.” (quoting Vivid Techs., Inc. v. Am. Sci. & Eng’g, Inc., 200 F.3d 795, 803
`(Fed. Cir. 1999))).
`2. Means-Plus-Function Limitations (claims 35 and 44)
`Petitioner proposes claim constructions for two means-plus-function
`limitations terms governed by § 112 ¶ 6. Pet. 5–6. Petitioner asserts that
`“means for sensing the input current” as recited in claim 35, has a function
`of “sensing input current” and the corresponding structure is an “input sense
`resistor, a transistor, or an inductive sensor.” Pet. 5–6 (citing Ex. 1001,
`21:2–5, 22:15–17; Ex. 1003 ¶ 21). Petitioner also argues that “means for
`sensing the output voltage on the battery” as recited in claim 44 has a
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`function of “sensing output voltage on the battery” and the corresponding
`structure is a battery sense terminal, an input, or an analog-to-digital circuit.”
`Pet. 6 (citing Ex. 1001, 22:12–19, 23:17–18; Ex. 1003 ¶ 22). Patent Owner
`does not dispute Petitioner’s constructions. See generally PO Resp. 16–19.
`Based on the full record, we agree with and adopt Petitioner’s identified
`functions and structures for the means-plus-function limitations of claims 35
`and 44.
`3. “the filtered current is reduced, in a current control mode, as a voltage
`on the battery increases.” (claim 1[g]);
`“wherein the first output current is reduced, in a current control mode,
`as the first output voltage on the battery increases” (claim 8[g]);
`“wherein, during at least a portion of the current control mode, . . . the
`current controller reduces the output current to the battery as the voltage
`on the battery increases” (claim 32[i])
`Patent Owner contends that the limitations in 1[g] and 32[i] “as the
`voltage on the battery increases” should be construed as “in response to a
`sensed increase in battery voltage” and that “as the first output voltage on
`the battery increases” as recited in claim limitation 8[g] should be construed
`as “in response to a sensed increase on the first output voltage.” PO Resp.
`18.7
`
`Patent Owner argues that under the broadest reasonable interpretation:
`a POSITA would understand “as a voltage on the battery
`increases” in the claims of the ’591 Patent to mean “in response
`to a sensed increase in battery voltage.” See EX2007, ¶ 58. The
`’591 Patent discloses “switching battery chargers that modify the
`battery current based on sensed circuit conditions such as
`battery voltage or input current to the switching regulator.”
`
`7 The ’591 patent describes charging current as “filtered current” (claim 1),
`“first output current” (claim 8), or “output current” (claim 32). Neither party
`has identified any difference among these terms with respect to the
`“charging current” at issue.
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`APPLE-1001, 1:67–2:3; see also EX2007, ¶ 60; APPLE-1001,
`2:46–50; 2:57–67; 3:8–12; 3:46–50; 5:23–30; 5:63–67; 6:11–14;
`11:11–16; 17:14–16; 17:26–31; 18:22–25; 18:36–39; 18:59–63.
`In describing Figure 10A, the ’591 Patent explains that the
`depicted charging profile occurs in response to sensing “either
`input current to the switching regulator or battery voltage.” See
`EX1001, 19:45–47; see also EX2007, ¶¶ 43–44. Claim elements
`[1g], [8g], and [32i] each claim an embodiment where battery
`current is modified based on the sensed battery voltage.
`PO Resp. 16. Patent Owner asserts that “[a]ny alternative construction of
`‘as a voltage on the battery increases,’ that relies on natural decreases in a
`current control mode” “renders the ‘as a battery voltage increases’ language
`superfluous.” PO Resp. 17 (citing Ex. 2007 ¶ 63).
`Petitioner contends that neither the ’591 Specification nor the plain
`language of the claims support Patent Owner’s proposed construction. Pet.
`Reply 10–11. Petitioner argues that Patent Owner’s proposed construction
`would import a limitation from the Specification, specifically one that limits
`the circuit to sensing voltage. Pet. Reply 10 (citing SuperGuide Corp. v.
`DirecTV Enters., Inc., 358 F.3d 870, 875 (Fed. Cir. 2004)). Petitioner
`asserts that the “as” a voltage or first output voltage increase language is not
`superfluous because the plain language adds a temporal requirement,
`confines the current reductions magnitude, and limits the type of battery
`charging. Pet. Reply 10.
`Finally, Petitioner argues that claim differentiation between
`independent claim 32 and dependent claim 44, which introduces a “means
`for sensing the output voltage on the battery to control the output [i.e.,
`charging] current to the battery to reduce as the voltage on the battery
`increases” (Ex. 1001, cl. 44), adds the express requirement of sensing battery
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`voltage indicating that it is not already so narrowed in independent claim 32.
`Pet. Reply 11.
`Based on the parties’ arguments and evidence, we agree with Patent
`Owner that the Specification teaches the broadest reasonable interpretation
`of the “as” voltage increases clauses of claims 1, 8, and 32 to be “in response
`to a sensed increase” in the battery voltage. See PO Resp. 17–18; see Tr.
`23:23–24:4 (Petitioner counsel agreeing that the there is a cause and effect
`relationship sensed between battery voltage increase and current). We also
`agree with Patent Owner that the ’591 patent discloses “switching battery
`chargers that modify the battery current based on sensed circuit conditions
`such as battery voltage or input current to the switching regulator.” Ex.
`1001, 1:67–2:3 (emphasis added); see PO Sur-reply 2–3. Furthermore, the
`’591 patent Specification teaches “the switching regulator may detect the
`rise in the battery voltage by sensing either the battery voltage directly, the
`input current, or other related parameters.” Ex.1001, 18:61–63. Thus, the
`’591 patent explains that indirect sensing methods by “other related
`parameters” fall within the scope of the claims.
`The plain language of the dependent claims also supports indirect
`sensing methods. We agree with Petitioner that dependent claim 44
`presumably narrows independent claim 32, requiring directly sensing the
`output voltage of the battery. Pet. Reply 8–9. Patent Owner’s argument that
`claim 44 merely adds the “means” for sensing the battery voltage does not
`address persuasively the claim differentiation, supported by the ’591
`Specification (Ex. 1001, 18:61–63). See PO Sur-reply 3. We find that
`independent claim 32, like claims 1 and 8, is not limited to direct voltage
`measurements, as dependent claims 35 and 43 add direct sensing of input
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`current to independent claim 32 (PO Sur-reply 3–4). These claims further
`support the broader scope of the independent claims, which are not limited
`to clauses to direct measurement of battery voltage.
`Accordingly, we agree with Patent Owner that the broadest reasonable
`construction of the plain language of the claim limitations 1[g] and 32[i]
`should be construed as “in response to a sensed increase in battery voltage”
`and that “as the first output voltage on the battery increases” as recited in
`claim limitation 8[g] should be construed as “in response to a sensed
`increase on the first output voltage.” PO Resp. 18. The “sensed increase,”
`however, is not limited to direct sensing, but may be indirect through “other
`related parameters” as the ’591 Specification teaches. Ex. 1001, 18:61–63.
`
`C. Principles of Law
`A patent claim is unpatentable under 35 U.S.C. § 103(a) if the
`differences between the claimed subject matter and the prior art are such that
`the subject matter, as a whole, would have been obvious at the time the
`invention was made to a person having ordinary skill in the art to which said
`subject matter pertains. KSR Int’l Co. v. Teleflex Inc., 550 U.S. 398, 406
`(2007). The question of obviousness is resolved on the basis of underlying
`factual determinations including (1) the scope and content of the prior art;
`(2) any differences between the claimed subject matter and the prior art;
`(3) the level of ordinary skill in the art; and (4) any secondary
`considerations, if in evidence.8 Graham v. John Deere Co., 383 U.S. 1, 17–
`18 (1966).
`
`
`8 Patent Owner does not present any objective evidence of nonobviousness
`(i.e., secondary considerations) as to any of the challenged claims.
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`D. Obviousness by Bell, Kester, Gong, and Martin
`(Claims 1–5, 7, 8, 10–12, 15, 18, 21, 23, 24, 28, 30–32, 37, 39–41, 44)
`1. Overview of Bell (Ex. 1005)
`Bell is a patent titled “Battery Charging Circuitry Having Supply
`Current Regulation.” Ex. 1005, code (54). Bells discloses:
`A power supply is disclosed for use in battery powered
`electronic devices. The power supply includes a power source
`which supplies power to the electronic device itself as well as to
`battery charging circuitry integral to the power supply. The
`battery charging circuitry monitors an output current, or other
`parameter, of the power source output. Feedback circuitry
`regulates the output of the battery charging circuitry so that
`output current, or other parameter of the power source output, is
`kept within predetermined limits.
`Id. at code (57). Bell provides a block diagram for a power supply and
`schematic circuit diagrams for a battery charger. Id. at Figs. 1, 4A, and 4B.
`Figure 1, below, shows a block diagram of Bell’s power supply circuitry.
`
`
`Figure 1 shows battery charger 20 to charge battery 14 and system
`DC/DC converter 12 to provide power to device circuitry. Id. at 3:31–42.
`Battery charger 20 includes a feedback control loop, which varies the
`charging rate of the battery during a charge to limit the current drawn from
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`power converter 19. Id. at 3:1–4. Figure 3 of Bell, shown below, provides a
`block diagram of the power supply circuitry. Id. at 3:3:22–25
`
`
`Bell’s battery charger 20 in Figure 1 includes “switching DC/DC converter”
`32 shown in Figure 3 that provides power to the battery. Id. at 6:55–61.
`Separate system DC/DC converter 12 provides power. Id. at 6:55–61, Fig. 3
`(showing two DC/DC converters, 32 and 12). Bell identifies the switching
`DC/DC converter used for battery charging as a “Buck” stepdown converter.
`Id. at 6:60–61.
`The battery charger circuit 20 in Figure 1, is shown in Figure 4A
`below.
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`
`Figure 4A shows integrated circuit 70 with “a conventional current-mode
`switching DC/DC converter” that includes DC/DC converter, shown in
`further detail in Figure 4B below. Id. at 6:55–57.
`
`
`Figure 4B shows more detail for integrated circuit 70 of Figure 4A,
`including switch circuitry 76. Ex. 1005, 6:52–58. Bell discloses that circuit
`70 employs three feedback loops: output current feedback loop (id. at 6:64–
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`7:4); output voltage feedback loop (id. at 8:2–21); and input current “third”
`feedback loop (id. at 8:22–42).
`2. Overview of Kester (Ex. 1007)
`Kester, which is titled “Practical Design Techniques for Power and
`Thermal Management” by Analog Devices, is a book that describes theory
`and applications in power management. See generally Ex. 1007. Section 3
`of Kester discloses an overview of the voltage and current relationships in
`conventional switching power converters, including a Buck regulator.
`Ex. 1007, 9–79 (Section 3). Kester explains that Buck regulators step down
`voltage and increase current so that “the input current is lower than the
`output current.” Ex. 1007, 3.3.
`3. Overview of Gong (Ex. 1008)
`Gong is a U.S. patent titled “Method and Apparatus for Rapidly
`Charging a Battery of a Portable Computing Device” and discloses
`“[i]mproved techniques for charging batteries within portable computing
`devices.” Ex. 1008, code (54), (57). Gong teaches that the invention
`“charge[s] a battery at an approximately constant power level by adjusting a
`charge current as the battery voltage changes.” Id. at code (57). Thus, “as
`the voltage of the battery increases, the charge current . . . is reduced” to
`allow charging to continue at a constant power level. Id. at 4:51–60. Figure
`1, below, shows a block diagram of a portable computing device and power
`supply through a battery.
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`Figure 1 shows power management microprocessor 106 is used to control
`the charging of battery 104. Id. at 3:61–67. Specifically, power
`management microprocessor 106 is coupled to battery charge circuit 108 to
`control charging of battery 104. Id. Power management microprocessor 106
`receives information from battery monitor 112 to determine suitable charge
`current (I_CHRG) and voltage (V_CHRG). Id. at 3:51–66, 4:24–30.
`Figure 2, below, shows an example battery charge circuit as depicted
`in battery charge circuit 108 of Figure 1. Id. at 4:61–64.
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`Figure 2 shows regulator 204, voltage control circuit 206, and current
`control circuit 208 used to generate the voltage or current. Id. at 5:11–32.
`Current control circuit 208 receives current charge signal (I_CHRG) from
`power management microprocessor 210 in Figure 1 and a feedback signal
`from feedback circuit 210 to generate current regulation signal (IRS). Id. at
`5:24–30, Fig. 1.
`
`4. Overview of Martin (Ex. 1006)
`Martin is a U.S. patent application titled, “Power Manager and Power
`Managing Method of Battery-Powered Application.” Ex. 1006, code (54).
`Martin discloses a power manager for “controlling power delivery to a load
`and a battery from a power source.” Ex. 1006 ¶ 1. Martin teaches that a
`“USB itself can be used to directly power [portable] devices and charge
`[their] batteries” when current from the USB source is regulated. Id. ¶ 2.
`5. Claim Analysis
`Petitioner argues that Bell, Gong, Kester, and Martin teach the
`limitations of claims 1–5, 7, 8, 10–12, 15, 18, 21, 23, 24, 28, 30–32, 37, 39–
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`41, and 44 of the ’591 patent. Pet. 10–85. Petitioner argues that combining
`Bell, Kester, and Gong, with Martin would have been obvious to further
`Bell’s goal of efficient and convenient battery charging. Pet. 18. Petitioner
`argues that
`[i]n the combination, a switching battery charger, as taught by
`Bell, would be configured to charge a lithium-ion battery from
`USB power, as known to a POSITA and further taught by Martin.
`The charger would also be digitally controlled using a
`microprocessor and digital-to-analog converters (DACs), as
`taught by Bell and Gong. The microprocessor would provide
`constant power control of charging, as taught by Gong, to
`achieve the goal of maximizing use of power capacity that is
`shared by Bell and Gong.
`Pet. 18 (citing Ex. 1003 ¶¶ 451–457). Petitioner provides annotated Figures
`4A and 4B from Bell illustrating the combination.
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`Pet. 18–19. Petitioner’s annotated Figures 4A and 4B from Bell show the
`block diagram combination of Bell, Kester, and Martin, with connections to
`Gong. Id.
`Petitioner argues that the combination of Bell and Martin teaches
`MOS transistors and that such transistors could be used in place of diodes in
`the transistor shown in Bell. Pet. 20–21; Ex. 1003 ¶ 471. Petitioner further
`asserts that a person of ordinary skill in the art would have known that USB
`specifications limit input current (Ex. 1003 ¶¶ 458–460) and that Bell’s
`circuitry could be configured to comply with USB limits in view of Martin
`(Ex. 1003 ¶¶ 458–470). Pet. 19–20; Ex. 1006 ¶¶ 2, 8. Petitioner also asserts
`that Kester teaches the basic operating principles of the Buck regulator used
`in Bell. Pet. 21; Ex. 1003 ¶¶ 147–153.
`With respect to Gong, Petitioner argues that the microprocessor
`control in Gong could be applied to the analog circuit of Bell to teach
`constant power control and input current limiting. Pet. 21–24. With respect
`to the combination of Gong and Bell, Petitioner asserts that “a
`microprocessor would digitally control battery charging current and
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`charging voltage, as taught by Gong” and that “Bell teaches that ‘a host
`microprocessor [can] program the current and voltage characteristics
`depend[e]nt on the design of battery 14.’” Pet 21–22 (quoting Ex. 1006,
`4:9–30; Ex. 1005, 9:10–12); Ex.1003, ¶¶ 473–480. Petitioner also argues
`that “Bell states that, when using a microprocessor, ‘programming resistors
`89 and 90, and voltage scaling resistors 40 and 42 may be replaced or
`combined with a digital-to-analog converter’ (DAC) for setting charging
`voltage and current.” Pet. 21–22 (quoting Ex. 1005, 9:8–12). Petitioner
`argues that it would have been obvious for a person of ordinary skill in the
`art to combine digital-to-analog converters (DACs) to interface the charger
`with a microprocessor, as taught by Bell. Pet. 21 (citing Ex. 1003 ¶¶ 473–
`480). Specifically, Petitioner argues that a person of ordinary skill in the art
`would have been motivated to use microprocessor control with the battery
`charging circuitry “to gain the flexibility to easily change current and
`voltage” and that the combination would yield predictable and effective
`results, as shown by Bell’s express teachings (Ex. 1005, 9:10–12) and the
`similarity in charging between Gong and Bell. Pet. 27–28 (citing Ex. 1005,
`6:47–51, Fig. 2C; Ex. 1008, 4:57–60; Ex. 1003 ¶¶ 450–482).
`Petitioner also asserts that the combination of Gong’s microprocessor
`with Bell’s charger would allow the microprocessor to determine the
`charging current and vary the charging voltage to make full use of the
`available power as Gong teaches. Pet. 22–23; Ex. 1003 ¶ 482; Ex. 1008,
`6:36–49, 10:9–44. Petitioner argues that Bell expressly teaches “that a
`charger should ‘maximize utilization’ of a power source and use ‘any or all
`of the excess power’ from a source for charging.” Pet. 23 (quoting Ex.
`1005, 2:57–60, 4:63–5:4). Petitioner argues that “Gong provides a technique
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`to achieve a similar maximization of charging power using digital control.”
`Pet. 23; Ex. 1008, 10:14–32; Ex. 1003 ¶¶ 481–482.
`Petitioner asserts that a person of skill in the art would have combined
`Bell, Kester, and Gong (and optionally Martin) to use the USB power source
`and produce a smaller and lighter external power supply. Pet. 25–26;
`Ex. 1005, 2:48–51;