Ex Parte Sardat

Patent Trial and Appeal Board

Aug 17, 2017

13618251 (P.T.A.B. Aug. 17, 2017)

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.
13/618,251 09/14/2012 Pierre Sardat 17381/066001 2290
22511 7590 08/21/2017
O SH ATT ANfi T I P
EXAMINER
TWO HOUSTON CENTER AHMAD, SHAHZEB K
909 FANNIN, SUITE 3500
HOUSTON, TX 77010 ART UNIT PAPER NUMBER
2838
NOTIFICATION DATE DELIVERY MODE
08/21/2017 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):
docketing@oshaliang.com
hathaway@oshaliang.com
escobedo @ oshaliang. com
PTOL-90A (Rev. 04/07)
UNITED STATES PATENT AND TRADEMARK OFFICE
BEFORE THE PATENT TRIAL AND APPEAL BOARD
Ex parte PIERRE SARD AT
Appeal 2016-003960
Application 13/618,251
Technology Center 2800
Before TERRY J. OWENS, CHRISTOPHER C. KENNEDY, and
JULIA HEANEY, Administrative Patent Judges.
OWENS, Administrative Patent Judge.
DECISION ON APPEAL
STATEMENT OF THE CASE
The Appellant appeals under 35 U.S.C. § 134(a) from the Examiner’
rejection of claims 1—17. We have jurisdiction under 35 U.S.C. § 6(b).
The Invention
The Appellant claims a method and assembly for reducing common
mode current. Claims 1 and 15 are illustrative:
1. A method of reducing common mode current flowing
between an internal ground of an electrical circuit and the Earth
ground, said circuit being supplied by an electrical network
delivering an alternating voltage, the method comprising:
applying a voltage by the electrical network between the
internal ground of the circuit and the Earth ground; and
applying an additional voltage between the internal
ground of the circuit and the Earth ground using an electronic
Appeal 2016-003960
Application 13/618,251
component interposed between the internal ground of the circuit
and the Earth ground, this additional voltage opposing the
voltage applied by the electrical network between the
internal ground and the Earth ground, so as to reduce the
common mode current at the frequency of the electrical
network.
15. An assembly, comprising:
an electrical circuit, comprising a rectification stage for
an alternating voltage, said stage having a positive output
terminal and a negative output terminal and the circuit having
an internal ground connected to one of said output terminals;
a frame; and
a component electrically connected first to the internal
ground of the circuit and secondly to the frame, the component
being configured for applying a voltage between the internal
ground of the circuit and the frame, when the electric circuit is
supplied by an electrical network, for reducing the current at the
frequency of the network flowing between the internal ground
and the frame.
The References
Pelly US 6,636,107 B2 Oct. 21,2003
Inoshita US 2007/0058406 A1 Mar. 15,2007
Satoshi Ogasawara et al., An Active Circuit for Cancellation of
Common-Mode Voltage Generated by a PWMInverter, 13 IEEE Trans, on
Power Electronics 835—41 (1998) (hereinafter Ogasawara).
Anirudh Acharya & Vinod John, Common Mode DC Bus Filter for Active
Front-End Converter, IEEE Int’l Joint Conf of Power Electronics, Drives &
Energy Systems 1—6 (2010) (hereinafter Acharya).
The Rejections
The claims stand rejected under 35 U.S.C. § 103 as follows:
claims 1—8, 10-13 and 15—17 over Acharya in view of Ogasawara, claim 9
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Appeal 2016-003960
Application 13/618,251
over Acharya in view of Ogasawara and Pelly, and claim 14 over Acharya in
view of Ogasawara and Inoshita.
OPINION
We reverse the rejections. We need address only the independent
claims (1,15 and 16).1
Acharya uses an LCL filter to reduce common mode current in an
active front-end converter (Abstract; p. 2; Fig. 1).
Ogasawara uses an active common-noise canceler (ACC) to cancel
common mode voltage generated by a pulsewidth modulation inverter such
that no common mode current flows (Abstract; pp. 835—36; Figs. 1, 2).
The Examiner finds that “having multiple filters maybe [sic] costly,
however will always be a benefit rather than being harmful to the output
waveform” (Ans. 3), and that
Acharya introduces a filter within the circuit that provides the
benefit of “reducing” common mode voltage and resulting in
minimum ground current injection (Acharya Abstract) while
also having the filters being placed at the input of the circuit of
the front end converters. In contrast, Ogasawara introduces a
filter that goes even further then [sic] reducing common mode
voltage and rather introduces a filter that eliminates/cancels
common mode voltage (Ogasawara Pg. 836) being placed at the
output of the converter to ensure no noise is created by the
converter switches when turning on/off. Acharya will simply
reduce common mode voltage which may later be introduced
by the switches within the converter therefore by adding a filter
as taught by Ogasawara one of ordinary skill in the art would be
able to achieve a further filtered signal leading to an
improvement within Acharya’s proposed schematic. The fact
1 The Examiner does not rely upon Pelly or Inoshita for any disclosure that
remedies the deficiency in Acharya and Ogasawara as to the independent
claims (Final Act. 12—23).
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Appeal 2016-003960
Application 13/618,251
that a filter placed at the input can filter the AC source to tune
the result towards the output and in combination with a filter at
the output to fine tune the resulting feedback or output will
yield a better result [(Ans. 4)].
Establishing a prima facie case of obviousness of an invention
comprising a combination of known elements requires “an apparent reason
to combine the known elements in the fashion claimed . . . KSR Int 7 Co.
v. Teleflex Inc., 550 U.S. 398, 418 (2007). The Examiner does not establish
that the relied-upon rationale for combining Ogasawara’s ACC with
Acharya’s LCL filter would have been apparent to one of ordinary skill in
the art from those references. Instead, the Examiner appears to reconstruct
the Appellant’s claimed invention from those references by use of
impermissible hindsight based upon the Appellant’s disclosure. See In re
Warner, 379 F.2d 1011, 1017 (CCPA 1967) (“A rejection based on section
103 clearly must rest on a factual basis, and these facts must be interpreted
without hindsight reconstruction of the invention from the prior art”).
Accordingly, we reverse the rejections.
DECISION/ORDER
The rejections under 35 U.S.C. § 103 of claims 1—8, 10-13 and 15—17
over Acharya in view of Ogasawara, claim 9 over Acharya in view of
Ogasawara and Pelly, and claim 14 over Acharya in view of Ogasawara and
Inoshita are reversed.
It is ordered that the Examiner’s decision is reversed.
REVERSED
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