Ex Parte De et al

Board of Patent Appeals and Interferences

Jul 22, 2011

11444188 (B.P.A.I. Jul. 22, 2011)

UNITED STATES PATENT AND TRADEMARK OFFICE
_____________

BEFORE THE BOARD OF PATENT APPEALS
AND INTERFERENCES
_____________

Ex parte SUKUMAR DE, KAMALESH HATUA, and MILAN MR RAJNE
_____________

Appeal 2009-009560
Application 11/444,188
Technology Center 2800
______________

Before ROBERT E. NAPPI, CARLA M. KRIVAK, and MICHAEL R.
ZECHER, Administrative Patent Judges.

NAPPI, Administrative Patent Judge.

DECISION ON APPEAL
Appeal 2009-009560
Application 11/444,188
2

This is a decision on appeal under 35 U.S.C. § 134(a) of the rejection
of claims 1 through 4, and 6 through 20.
We affirm.
INVENTION
The invention is directed a common mode filter for a motor controller.
See paragraphs 1, 2, and 21. Claim 1 is representative of the invention and
reproduced below:
1. A motor drive circuit comprising:
a converter for coupling to an AC voltage source;
an inverter coupled to the converter for providing a drive current for a
motor;
a common mode circulation loop coupled to the converter and to the
inverter that circulates common mode current from both the converter and
the inverter.

REFERENCE
Lipo US 5,661,390 Aug. 26, 1997
Peterson US 6,154,378 Nov. 28, 2000

REJECTION AT ISSUE
The Examiner has rejected claims 1 through 4 and 6 through 20 under
35 U.S.C. § 103(a) as being unpatentable over Lipo in view of Peterson.
Answer 3-7.
1

1
Throughout this opinion we refer to the Examiner’s Answer mailed on
October 6, 2008.
Appeal 2009-009560
Application 11/444,188
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ISSUES
Appellants argue on pages 10 through 12 of the Brief that the
Examiner’s rejection based upon Lipo in view of Peterson is in error.
2

These arguments present us with the following issues:
a) Did the Examiner err in finding that Lipo teaches a common mode
loop?
b) Did the Examiner err in finding that Peterson teaches circulating
common mode current from both a converter and an inverter?
c) Did the Examiner error in combining Lipo and Peterson?
Appellants provide an additional argument directed to claim 16 on
page 12 of the Brief. This argument presents us with the additional issue;
did the Examiner err in finding the combination of the references teaches
that common mode current rises from conversion of an AC signal to a DC
signal or from providing a drive current to a motor?

ANALYSIS
First issue:
We have reviewed the Examiners’ rejection in light of Appellants’
arguments that the Examiner has erred. We disagree with Appellants’
conclusion that the Examiner erred in finding that Lipo teaches a common
mode loop. We adopt as our own (1) the findings and reasons set forth by
the Examiner in the action from which this appeal is taken and (2) the
reasons set forth by the Examiner in the Examiner’s Answer in response to

2
Throughout this opinion we refer to the Appeal Brief dated March 27,
2008, and the Reply Brief dated December 3, 2008.
Appeal 2009-009560
Application 11/444,188
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Appellants’ Appeal Brief. We concur with the conclusion reached by the
Examiner.
Specifically, Appellants argue on pages 9 and 10 of the Brief that the
claims recite a loop and that, interpreted in light of the Specification, the
“common mode loop current circulates within the filter loop and does not
flow through the system ground.” Brief 10-11. We disagree with
Appellants’ claim interpretation. That is, representative claim 1 merely
recites “a common mode circulation loop…that circulates common mode
current from both the converter and the inverter.” Claim 1 does not recite
that the current recirculates from one to the other, nor does claim 1 include a
limitation that precludes the loop having a connection to ground. While
Appellants’ Specification may describe such a loop, we decline to import
such limitations from the Specification into the claims.
The Examiner has found that Lipo implicitly, but not explicitly,
recites circulating common mode current from both the converter and the
inverter. Answer 3. The Examiner relied upon Peterson to teach that the
current from one filter circulates into the other. Answer 3. However, as
discussed above, claim 1 is not limited to a loop in which current from one
filter circulates into the other.
We concur with the Examiner’s finding that Lipo’s Figure 2A and 2B
depict a motor controller including an AC-DC converter with a common
mode filter connected to it and a DC-AC converter with a common mode
filter connected to it, see also col. 7, ll. 31-40, col. 8, ll. 21-30 (common
mode current in DC-AC converter) ll. 31-38 (common mode current in DC-
AC converter that provides current to motor). We note that the schematics
of Figures 2A and 2B both show the filters are connected to ground,
however, these are schematics and the circuit is equivalent to a circuit where
Appeal 2009-009560
Application 11/444,188
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all of the filters are connected together at a node that is grounded, and as
such is a loop. Thus, Appellants’ arguments have not persuaded us that the
Examiner erred in finding that Lipo teaches a common loop.
Second and third issue.
We are not persuaded the Examiner erred in finding that Peterson
teaches circulating common mode current from both a converter and inverter
or in combining Lipo and Peterson. As discussed above, the Examiner
relied upon Peterson to teach that the current from one filter circulates into
the other, a feature which is not recited in the representative claim. Rather,
as discussed above the claim merely recites the current circulates in the loop,
which is taught by Lipo. Thus, regardless of whether Peterson teaches
circulating common mode current from both a converter and inverter or is
properly combined with Lipo, we find that Lipo teaches the claimed
limitations.
3
Accordingly, we sustain the Examiner’s rejection of claims 1
through 4 and 6 through 15.

Claims 16-20
Appellants’ additional arguments have not persuaded us that the
Examiner erred in finding the combination of the references teach that
common mode current rises from conversion of an AC signal to a DC signal
or from providing a drive current to a motor. Appellants’ arguments focus

3
We additionally note Appellants’ argument is also not persuasive as it is
not commensurate with the claim scope. Peterson teaches that the common
mode current flows through the AC source which is connected to the
inverter. Representative claim 1 does not recite that the common mode loop
is directly connected to the inverter (i.e., claim 1 does not preclude the
common mode current from the inverter circulating through the AC source).
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Application 11/444,188
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on Peterson which does not teach this feature. However, as discussed above,
Lipo teaches these features. Accordingly we sustain the Examiner’s
rejection of claims 16-20.

ORDER
The decision of the Examiner to reject claims 1 through 4, and 6
through 20 is affirmed.
No time period for taking any subsequent action in connection with
this appeal may be extended under 37 C.F.R. § 1.136(a)(1)(iv).

AFFIRMED

ELD