Ex Parte Lomax et al

Board of Patent Appeals and Interferences

Jun 8, 2011

11184634 (B.P.A.I. Jun. 8, 2011)

UNITED STATES PATENT AND TRADEMARK OFFICE
____________

BEFORE THE BOARD OF PATENT APPEALS
AND INTERFERENCES
____________

Ex parte CHARLES WESTON LOMAX, JR.
and JAMES XAVIER TOROK
____________

Appeal 2009-009191
Application 11/184,634
Technology Center 2800
____________

Before JOSEPH F. RUGGIERO, CARLA M. KRIVAK, and
THOMAS S. HAHN, Administrative Patent Judges.

RUGGIERO, Administrative Patent Judge.

DECISION ON APPEAL
STATEMENT OF THE CASE
Appellants appeal under 35 U.S.C. § 134(a) from the Final Rejection
of claims 1-5 and 8, which are all of the pending claims. Claims 6 and 7
have been canceled. We have jurisdiction under 35 U.S.C. § 6(b).
We affirm.
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Application 11/184,634

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Rather than reiterate the arguments of Appellants and the Examiner,
reference is made to the Appeal Brief (filed June 21, 2007), the Answer
(mailed October 18, 2007), and the Reply Brief (filed December 18, 2007)
for the respective details. Only those arguments actually made by
Appellants have been considered in this decision. Arguments which
Appellants could have made but chose not to make in the Briefs have not
been considered and are deemed to be waived (see 37 C.F.R.
§ 41.37(c)(1)(vii).

Appellants’ Invention
Appellants’ invention relates to the monitoring of voltage input to
network elements. Particularly, an input voltage is applied across a primary
winding of a flyback power converter during the on-time of a primary
switch. During the off-time of the switch, the input voltage from the
primary winding is transferred to the secondary winding of the flyback
power converter. The voltage of the secondary winding is sensed during the
on-time of the switch. See generally Spec. ¶ ¶ [0020]-[0021].

Claim 1 is illustrative of the invention and reads as follows:

1. A voltage sensing circuit, comprising;
a diode coupled to the secondary side of a flyback power converter,
the diode adapted to limit current in the voltage sensing circuit;
a first capacitor coupled to the diode, the first capacitor adapted to
filter voltage spikes that occur during switch transitions on the primary side
of the flyback power converter; and
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Application 11/184,634

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an output filter adapted to peak charge an output voltage, wherein the
output voltage is proportional to an input voltage of the flyback power
converter.

The Examiner’s Rejections
The Examiner relies on the following prior art references to show
unpatentability:
Bang US 5,621,625 Apr. 15, 1997
Jennings US 6,119,238 Sep. 12, 2000
Ng US 6,396,718 B1 May 28, 2002

Claims 1, 3, 4, and 8 stand rejected under 35 U.S.C. § 102(b) as being
anticipated by Ng.
Claims 1-5 and 8, all of the appealed claims, stand rejected under 35
U.S.C. § 102(b) as being anticipated by Jennings.
Claims 2 and 5 stand rejected under 35 U.S.C. § 103(a) as being
unpatentable over Ng in view of Bang.

ANALYSIS
35 U.S.C. § 102(b) REJECTIONS
The Ng reference
Appellants’ arguments with respect to the anticipation rejection of
independent claims 1, 3, and 8 based on Ng focus on the contention that,
contrary to the Examiner’s finding, the diode 270 in Ng does not “limit”
current as claimed. According to Appellants (App. Br. 5-8; Reply Br. 1-2),
the claim term “limit” must be construed as confining or restricting current
within a boundary. In Appellants’ view (App. Br. 5), an ordinarily skilled
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Application 11/184,634

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artisan would not consider a diode that is not forward biased, i.e., OFF, as
limiting current as posited by the Examiner.
We do not agree with Appellants as we find no support in Appellants’
disclosure for the claim interpretation urged by Appellants in the Briefs. It
is noteworthy that the term “limit” is not used in the description of the
operation of the claimed voltage sensing circuit diode D2 in Appellants’
Specification (¶¶ [0041]-[0044]). As described, current is blocked from
flowing through voltage sensing circuit diode D2 until switch Q1 turns on
and biases diode D2 to allow current flow to charge capacitor C2 to a
voltage proportional to the input voltage of the converter 102. Accordingly,
we find no error in the Examiner’s finding (Ans. 7) that the description of
the operation of Ng’s diode 270 can be reasonably interpreted as blocking or
limiting current from flowing until it is forward biased to allow current flow,
which comports with what is described in Appellants’ Specification. Ng,
col. 4, ll. 57-67.
Further, to whatever extent Appellants are contending that the amount
of current flow is being restricted by their diode D2, we find that such
current flow restriction is not performed by diode D2 in and of itself. In
other words, while circuitry associated with diode D2 may restrict the
amount of current flow through diode D2, no such circuitry is being claimed.
We also agree with the Examiner (Ans. 7) that the amount of current flow
through Ng’s diode 270 is being controlled in accordance with associated
circuitry, i.e., the reference voltage in optocoupler voltage sensing circuit
260 (col. 5, ll. 14-27).
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In view of the above discussion, the Examiner’s 35 U.S.C. § 102(b)
rejection of independent claims 1, 3, and 8, as well as dependent claim 4 not
separately argued by Appellants, is sustained.

The Jennings reference
We also sustain the Examiner’ anticipation rejection of all of the
appealed claims 1-5 and 8 based on Jennings. Appellants reiterate (App. Br.
8-9; Reply Br. 2-3) their arguments that the diode D2 in Jennings, as with
the diode D2 in Ng, cannot be interpreted as limiting current in the OFF
state. We refer to our discussion with regard to Ng which found such
arguments unpersuasive. We also agree with the Examiner (Ans. 9) that the
diode D2 in Jennings is part of a voltage sensing circuit which supplies a
detected voltage at junction point 16 (col. 3, ll. 1-9).

35 U.S.C. § 103(a) REJECTION
The Examiner’s obviousness rejection of claims 2 and 5 based on the
combination of Ng and Bang is sustained as well. Appellants’ arguments
(App. Br. 12-13) rely on the arguments asserted previously against the
Examiner’s anticipation rejection, based on Ng, of claims 1, 3, 4, and 8,
which arguments we have found to be unpersuasive for all of the previously
discussed reasons.

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CONCLUSION
Based on the analysis above, we conclude that the Examiner did not
err in rejecting claims 1, 3, 4, and 8, based on Ng, and claims 1-5 and 8,
based on Jennings, for anticipation under 35 U.S.C. § 102(b), and claims 2
and 5, based on the combination of Ng and Bang, for obviousness under
35 U.S.C. § 103(a).

DECISION
The Examiner’s decision rejecting claims 1-5 and 8 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

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