Renesas Electronics America Inc.

Patent Trials and Appeals Board

Nov 16, 2020

2019006957 (P.T.A.B. Nov. 16, 2020)

UNITED STATES PATENT AND TRADEMARK OFFICE
UNITED STATES DEPARTMENT OF COMMERCE
United States Patent and Trademark Office
Address: COMMISSIONER FOR PATENTS
P.O. Box 1450
Alexandria, Virginia 22313-1450
www.uspto.gov
APPLICATION NO. FILING DATE FIRST NAMED INVENTOR ATTORNEY DOCKET NO. CONFIRMATION NO.
14/299,186 06/09/2014 Tetsuo Sato 118177-0508 4716
141748 7590 11/16/2020
FOLEY & LARDNER LLP
3000 K STREET N.W.
SUITE 600
WASHINGTON, DC 20007-5109
EXAMINER
DE LEON DOMENECH, RAFAEL O
ART UNIT PAPER NUMBER
2838
NOTIFICATION DATE DELIVERY MODE
11/16/2020 ELECTRONIC
Please find below and/or attached an Office communication concerning this application or proceeding.
The time period for reply, if any, is set in the attached communication.
Notice of the Office communication was sent electronically on above-indicated "Notification Date" to the
following e-mail address(es):
ipdocketing@foley.com
PTOL-90A (Rev. 04/07)
UNITED STATES PATENT AND TRADEMARK OFFICE
BEFORE THE PATENT TRIAL AND APPEAL BOARD
Ex parte TETSUO SATO, KAZUHITO AYUKAWA, and
HIROSHI MURAKAMI

Appeal 2019-006957
Application 14/299,186
Technology Center 2800
Before ALLEN R. MACDONALD, CAROLYN D. THOMAS, and
MICHAEL J. STRAUSS, Administrative Patent Judges.
STRAUSS, Administrative Patent Judge.
DECISION ON APPEAL1

1 We refer to the Specification, filed June 9, 2014 (“Spec.”); Final Office
Action, mailed December 20, 2018 (“Final Act.”); Advisory Action, mailed
March 29, 2019 (“Advisory Act.”); Appeal Brief, filed June 24, 2019
(“Appeal Br.”); Examiner’s Answer, mailed July 26, 2019 (“Ans.”); and
Reply Brief, filed September 26, 2019 (“Reply Br.”).
Appeal 2019-006957
Application 14/299,186
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STATEMENT OF THE CASE
Pursuant to 35 U.S.C. § 134(a), Appellant2 appeals from the
Examiner’s decision to reject claims 1, 4, 5, 11, 14–16, and 21–25. See
Final Act. 1. We have jurisdiction under 35 U.S.C. § 6(b).
We AFFIRM.
CLAIMED SUBJECT MATTER
The claims are directed to a multi-phase transformer-type dc-dc
converter. Spec., Title. Claim 1, reproduced below with claim elements
labeled and disputed limitations emphasized in italics, is illustrative of the
claimed subject matter:
1. An isolated DC-DC converter comprising:
[(A)] an output node at which an output voltage can be
generated;
[(B)] an input node for receiving an input voltage;
[(C)] N transformers, where N is greater than 1;
[(D)] N full-bridge drivers for driving respective primary
sides of the N transformers;
[(E)] N circuits coupled to the N full-bridge drivers,
respectively, wherein the N circuits are configured to
generate N first voltages, respectively, each having a
value corresponding to a current flow from the input
node and through the respective N full-bridge drivers,
respectively;
[(F)] wherein the N full-bridge drivers are controlled by
respective N sets of pulse width modulation (PWM)
signals, wherein the N sets of PWM signals are phase
shifted with respect to each other, wherein the phase
shift between the N sets of PWM signals depends on
N;

2 We use the word Appellant to refer to “applicant” as defined in 37 C.F.R.
§ 1.42. Appellant identifies the real party in interest as Renesas Electronics
America, Inc. Appeal Br. 2.
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[(G)] N PWM generators for generating the N sets of PWM
signals. respectively;
[(H)] wherein widths of PWM signals in the N sets of PWM
signals, depend on the N first voltages, respectively;
[(I)] wherein the N PWM generators can vary the widths of
the PWM signals, respectively, to maintain the output
voltage at a target voltage,
[(J)] [(1)] wherein each of the primary sides of the N
transformers is selectively coupled to a first ground
terminal, but not a second ground terminal, and
wherein each secondary side of the N transformers is
directly or indirectly coupled to the second ground
terminal, but not the first ground terminal,
[(2)] wherein the first and second ground terminals are
electrically isolated from each other.
Appeal Br. 12 (Claims Apppendix).
REFERENCES
The prior art relied upon by the Examiner is:
Name Reference Date
Matsukawa US 2002/0126517 A1 Sept. 12, 2002
Lin US 2003/0048648 A1 Mar. 13, 2003
Chen US 2013/0293203 A1 Nov. 7, 2013
KINJO US 2013/0300397 A1 Nov. 14, 2013
TAN US 2014/0042812 A1 Feb. 13, 2014

REJECTIONS
Claims 1, 4, 11, 14–16, 21–22 and 24 stand rejected under 35 U.S.C.
§ 103 as being unpatentable over Matsukawa, Tan, and Kinjo. Final Act. 4–
11.
Claim 5 stands rejected under 35 U.S.C. § 103 as being unpatentable
over Matsukawa, Tan, Kinjo, and Lin. Final Act. 11.
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Claims 23 and 25 stand rejected under 35 U.S.C. § 103 as being
unpatentable over Matsukawa, Tan, Kino, and Chen. Final Act. 11–12.

STANDARD OF REVIEW
We review the appealed rejections for error based upon the issues
identified by Appellant, and in light of the arguments and evidence produced
thereon. Ex parte Frye, 94 USPQ2d 1072, 1075 (BPAI 2010) (precedential).
ANALYSIS
We have reviewed the Examiner’s rejections in light of Appellant’s
arguments. We have considered in this Decision only those arguments
Appellant actually raised in the Briefs. Any other arguments Appellant
could have made but chose not to make in the Briefs are deemed to be
waived. See 37 C.F.R. § 41.37(c)(1)(iv).
To the extent consistent with our analysis herein, we adopt as our own
the findings and reasons set forth by the Examiner in (1) the action from
which this appeal is taken (Final Act. 3–13) and (2) the Examiner’s Answer
in response to Appellant’s Appeal Brief (Ans. 3–8) and concur with the
conclusions reached by the Examiner. We highlight the following for
emphasis.
The Examiner finds Matsukawa’s direct current (dc) to dc converter
teaches the input and output nodes, transformers, and drivers recited by
claim elements (A) through (D) together with the disputed limitations of
claim element (J). Final Act. 4–5. The Examiner finds Tan’s power supply
teaches controlling transformer driver circuits with phase-shifted pulse-
width modulation (PWM) signals as required by claim elements (F) and (G).
Id. at 5. According to the Examiner “[i]t would have been obvious . . . to
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modify the device of Matsukawa to include PWM control structure as
disclosed in Tan to improve the efficiency of the control structure by
providing a multiphase PWM structure to the multiphase converter circuit.”
Id. The Examiner relies on Kinjo’s power converter for teaching the
remaining circuitry recited by claim elements (E), (H), and (I). Id. at 5–6.
The Examiner determines “[i]t would have been obvious . . . to modify the
device of Matsukawa to include an input current detection circuit as
disclosed in Kinjo to sense the current of the N drivers and provide and input
to the PWM controller.” Id. at 6.
Addressing the disputed limitations, under a broad but reasonable
interpretation, the Examiner determines “a ground terminal is a voltage
reference terminal -- i.e., the voltage potential which other, nearby voltages
are measured in relation to. A ground terminal is not read to be an earth
ground specifically, or any other specific kind of terminal connection.” Id.
at 13. Accordingly, the Examiner finds the first (input) ground terminal of
claim 1 is taught by Matsukawa’s negative terminal of input power source
Ed. Id. The Examiner further finds Matsukawa’s transformer’s Tr1 and Tr2
“provide[] at least some isolation between the first and second ground
terminals.” Id.
Appellant contends Matsukawa fails to teach (i) the first (i.e., power
input) or second (i.e., power output) ground terminals of claim element
(J)(1) (Appeal Br. 8) and (ii) that these ground terminals are electrically
isolated from each other as required by claim element (J)(2) (id. at 9–11). In
arguing contention (i), Appellant asserts a requirement of a ground terminal
is that it be connected to ground. Id. at 8. Appellant argues the prior art is
deficient in that neither of the power input battery terminals depicted in
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Figure 16 of Matsukawa are shown to be connected to ground and therefore
fail to teach the claimed first ground terminal. Id. Appellant similarly
argues neither of Matsukawa’s power output terminals providing Vo are
shown connected to ground and therefore fail to teach the claimed second
ground terminal. Id.
Addressing contention (ii), Appellant’s first argument is based on the
previously argued failure of Matsukawa to teach a ground terminal:
“because Matsukawa does not disclose or suggest any connections of the
primary and secondary windings to separate ground terminals as set forth
above, it logically follows that Matsukawa cannot disclose or suggest
different ground terminals that are electrically isolated from each other as is
further required by the claims.” Id. at 9. Appellant further argues
[T]here is no explicit teaching in Matsukawa that the alleged
primary and secondary windings are electrically isolated from
each other as required by the claims. Likewise, any theory that
Matsukawa inherently teaches such an electrical isolation
between these terminals would be clearly erroneous at least
because one cannot prove with certainty that Matsukawa’s
converter is an isolated converter. Rather, it is at least equally
likely that Matsukawa’s is a non-isolated converter, in which
case the primary and secondary windings are commonly
connected to each other (e.g. via a common ground connection)
(and not at least partially isolated from each other as stated in the
Office Action).
Id. at 10. Appellant further argues the Examiner’s finding that Matsukawa’s
converter provides some isolation is insufficient to teach that the terminals
an electrically isolated from each other, Appellant distinguishing between
electric isolation required by the claims and magnetic coupling provided by
transformers. Id. at 10–11.
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The Examiner responds, finding “Appellant's arguments fail to
explain how the term ‘ground’ is specially defined to be anything besides a
reference node. Therefore the Examiner takes the position that the claimed
term ground is defined as a reference node.” Ans. 6. Addressing
Appellant’s contention (ii), the Examiner explains
As Appellant clearly states in the first full paragraph of page 10
of the Appeal Brief, in a non-isolated converter, “the primary and
secondary windings are commonly connected to each other (e.g.
via a common ground connection)”. As clearly shown in Fig. 16
. . . of Matsukawa the primary and secondary windings are not
commonly connected to each other via a common ground or any
other connection besides the isolated magnetic core of the
transformer. Therefore Matsukawa must teach an isolated
converter.
Id. at 8.
Appellant’s contentions are unpersuasive of reversible Examiner
error. In connection with Appellant’s argument that Matsukawa fails to
disclose the recited ground terminals of claim 1 because neither of
Matsukawa’s terminals are actually connected to ground, Appellant fails to
provide sufficient evidence to persuade us that the Examiner’s interpretation
of a ground terminal as a reference node is inconsistent with Appellant’s
Specification or is otherwise improper. Appellant does not identify, and we
do not ascertain, any definition or description in the Specification of a
ground terminal that either requires the terminal be connected to ground3 or
that otherwise conflicts with the Examiner’s interpretation.

3 We interpret Appellant’s argument to be that a ground terminal must be
connected to an “earth” ground or otherwise be maintained at a zero
potential with respect to the earth.
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In the absence of a definition of certain claim terms in the
Specification, it is helpful to consult a dictionary to determine the ordinary
meanings of the terms.4 A common definition of a “ground connection” is
“1. A low-resistance connection to the earth. 2. The common point, such as a
chassis, to which zero-potential terminals of circuit components are
connected.” STAN GIBILISCO, THE ILLUSTRATED DICTIONARY OF
ELECTRONICS 321 (McGraw-Hill) (2001). Thus, although a ground
terminal may be one that is connected to the earth, the Examiner’s
interpretation as a reference node is reasonable as consistent with dictionary
definition 2.
Furthermore, Appellant’s asserted interpretation is inconsistent with
the requirements of claim 1. In particular, if, as posited by Appellant, a
ground terminal must be connected to ground, then both the first and second
ground terminals must be connected to a common potential, i.e., ground
potential. However, if both ground terminals are connected to ground, then
the terminals are also connected to each other through ground and would not
be electrically isolated from each other as required by the argued limitation.

4 “Dictionaries or comparable sources are often useful to assist in
understanding the commonly understood meaning of words,” and judges
“may also rely on dictionary definitions when construing claim terms, so
long as the dictionary definition does not contradict any definition found in
or ascertained by a reading of the patent documents.” See Phillips v. AWH
Corp., 415 F.3d 1303, 1322-23 (Fed. Cir. 2005)(citations omitted); Vitronics
Corp. v. Conceptronic, Inc., 90 F.3d 1576, 1584 n.6 (Fed. Cir. 1996)
(“[T]echnical treatises and dictionaries . . . are worthy of special note.
Judges are free to consult such resources at any time . . . and may also rely
on dictionary definitions when construing claim terms . . . .”).

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Therefore, Appellant’s proffered interpretation is inconsistent with the claim
language and is unreasonable.
We are further unpersuaded by Appellant’s argument that Matsukawa
fails to teach the first and second ground terminals are electrically isolated
from each other. Appeal Br. 10. The Examiner finds, and we agree, the
only connections between Matsukawa’s battery Ed and the terminals
providing output voltage Vo is via the magnetic coupling provided by
transformers Tr1 through Tr3. As disclosed by Appellant’s Specification,
rather than provide an electrical connection, transformers isolate circuits
from each other. See, e.g., Spec. ¶ 48 (“Since current sense circuit 636
includes a transformer in Figure 8, current sense circuit 636 maintains
electrical isolation of grounds GNDl and GND2”); see also STAN
GIBILISCO, THE ILLUSTRATED DICTIONARY OF ELECTRONICS
690 (“transformer 1 . A device using electromagnetic induction to transfer
electrical energy from one circuit to another (i.e., without direct connection
between them.)”). Appellant’s argument to the contrary is not only
unsupported by sufficient evidence but is inconsistent with Appellant’s
disclosure. Thus, one skilled in the art would have understood Matsukawa’s
transformers electrically isolate an input from an output. Accordingly, we
are unpersuaded by Appellant’s argument that, in the absence of an explicit
statement that Matsukawa’s “primary and secondary windings are
electrically isolated from each other” (Appeal Br. 10) the Examiner erred in
finding Matsukawa teaches first and second ground terminals electrically
isolated from each other.
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For the reasons discussed, we are unpersuaded by Appellant
contentions of error in connection with the rejection of independent claims 1
and 11. Accordingly, we sustain the rejection of independent claims 1 and
11 under 35 U.S.C. § 103 together with the rejections of dependent claims 4,
5, 14–16, and 21–25, which are not argued separately with particularity.
CONCLUSION
We affirm the Examiner’s rejection of claims 1, 4, 11, 14–16, 21–22
and 24 under 35 U.S.C. § 103 as being unpatentable over Matsukawa, Tan,
and Kinjo.
We affirm the Examiner’s rejection of claims 5 under 35 U.S.C. § 103
as being unpatentable over Matsukawa, Tan, Kinjo, and Lin.
We affirm the Examiner’s rejection of claims 23 and 25 under 35
U.S.C. § 103 as being unpatentable over Matsukawa, Tan, Kino, and Chen.
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DECISION SUMMARY
Claims
Rejected
35 U.S.C. § Reference(s)/Basis Affirmed Reversed
1, 4, 11, 14–
16, 21–22,
24
103 Matsukawa, Tan,
Kinjo
1, 4, 11, 14–
16, 21–22,
24

5 103 Matsukawa, Tan,
Kinjo, Lin
5
23, 25 103 Matsukawa, Tan,
Kinjo, Chen
23, 25
Overall
Outcome
1, 4, 5, 11,
14–16, 21–
25

TIME PERIOD FOR RESPONSE
No time period for taking any subsequent action in connection with
this appeal may be extended under 37 C.F.R. § 1.136(a). See 37 C.F.R.
§ 1.136(a)(1)(iv).
AFFIRMED