Ex Parte Melanson

Patent Trial and Appeal Board

May 27, 2014

11967276 (P.T.A.B. May. 27, 2014)

UNITED STATES PATENT AND TRADEMARK OFFICE
____________

BEFORE THE PATENT TRIAL AND APPEAL BOARD
____________

Ex parte JOHN L. MELANSON
____________

Appeal 2012-006195
Application 11/967,276
Technology Center 2800
____________

Before ADRIENE LEPIANE HANLON, KAREN M. HASTINGS, and
GEORGE C. BEST, Administrative Patent Judges.

BEST, Administrative Patent Judge.

DECISION ON APPEAL

Appeal 2012-006195
Application 11/967,276
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On November 10, 2010, the Examiner finally rejected claims 1-26 of
Application 11/967,276 under 35 U.S.C. § 103(a) as obvious. Appellant1
seeks reversal of these rejections pursuant to 35 U.S.C. § 134(a). We have
jurisdiction under 35 U.S.C. § 6(b).
For the reasons set forth below, we AFFIRM.
BACKGROUND
The ’276 Application describes a power factor controller with a digital
finite impulse response (“FIR”) filter for output voltage sampling. Spec. ¶ 2.
Claim 1 is representative of the ’276 Application’s claims and is
reproduced below:
1. An apparatus comprising:
a FIR filter to generate discrete samples of an output voltage
feedback signal associated with an output voltage of a
switching power converter, wherein the FIR filter is configured
to generate the discrete samples at a sampling frequency fS, the
sampling frequency fS is approximately an integer multiple of a
line frequency fL, and the line frequency fL is a frequency of a
line input voltage supplied to the switching power converter;
and
a switch state controller, coupled to the FIR filter, wherein the
switch state controller is configured to:
receive a signal associated with the discrete samples
generated by the FIR filter;
use the received signal to generate a control signal to
provide power factor correction and to regulate the
output voltage of the switching power converter; and

1 Cirrus Logic, Inc. is identified as the real party in interest. (App. Br. 2.)
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provide the control signal to the switching power
converter.
(App. Br. 20 (Claims App’x).)
REJECTIONS
On appeal, the Examiner maintains the following rejections:
1. Claims 1, 2, 4-6, 8, 9, 11-14, 16-19, 21, 22, and 24-26 are rejected
under 35 U.S.C. § 103(a) as unpatentable over the combination of
Zhang2 and Kronmüller.3 (Ans. 5.)
2. Claims 3 and 15 are rejected under 35 U.S.C. § 103(a) as
unpatentable over the combination of Zhang, Kronmüller, and
Maksimovic.4 (Ans. 9.)
3. Claims 7 and 20 are rejected under 35 U.S.C. § 103(a) as
unpatentable over the combination of Zhang, Kronmüller, and
Gritter.5 (Ans. 10.)
4. Claims 10 and 23 are rejected under 35 U.S.C. § 103(a) as
unpatentable over the combination of Zhang, Kronmüller, and
Jepsen.6 (Ans. 11.)

2 U.S. Patent Application Publication No. 2005/0270813 A1, published Dec.
8, 2005.
3 U.S. Patent No. 4,737,658, issued April 12, 1988.
4 D. Maksimovic et al., “Impact of Digital Control in Power Electronics,” in
PROCEEDINGS OF THE 2004 INTERNATIONAL SYMPOSIUM ON POWER
SEMICONDUCTOR DEVICES AND ICS, 2 (2004).
5 U.S. Patent Application Publication No. 2005/0207190 A1, published Sept.
22, 2005.
6 U.S. Patent Application Publication No. 2005/0275386 A1, published Dec.
15, 2005.
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DISCUSSION
Rejection 1. Appellant’s arguments for reversal of this rejection
focus upon claim 1’s limitations. (App. Br. 10.) Appellant argues that the
rejection of the other independent claims should be reversed because they
contain limitations similar to those argued in connection with claim 1. (Id.;
see also id.at 17.) We, therefore, limit our discussion to claim 1.
The Examiner finds, and Appellant does not contest, that Zhang
describes every limitation in claim 1 except that
Zhang is silent on whether the circuit includes a FIR filter to
generate the discrete samples at a sampling frequency, the
sampling frequency is approximately an integer multiple of a
line frequency, and the line frequency is a frequency of a line
input voltage supplied to the switching power converter.
(Ans. 6.)
The Examiner finds that Kronmüller describes a controller which has
a FIR filter following an analog to digital converter (“ADC”). (Id.) The
Examiner concludes:
[i]t would have been obvious to one of ordinary skill in the art
at the time of invention to modify the apparatus, associated
method, and means for of Zhang to include a FIR filter as
taught by Kronmüller to have zero points indicating infinite
attenuation for frequencies which correspond to the harmonic
frequencies of the line frequency and to control frequencies of
adjacent centralized control services (see e.g., Kronmüller --
column 2, lines 31-36).
(Id.)
Appellant argues that this rejection should be reversed for three
reasons: (1) neither Zhang or Kronmüller teach or suggest using
Kronmüller’s FIR filter as part of the feedback loop described in Zhang
(App. Br. 14), (2) the prior art does not describe or suggest a controller
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configured to provide a power factor correction and to regulate the output
voltage of the switching power converter (id. at 14-15), and (3) the
combination of Zhang and Kronmüller improperly uses hindsight and is
contrary to KSR Int’l Co. v. Teleflex Inc., 550 U.S. 398 (2007) (id. at 16).
We are not persuaded by these arguments.
First, the Examiner found that a person of ordinary skill in the art
would have added the FIR filter described in Kronmüller to Zhang’s
apparatus because the FIR filter
is beneficial when used in a controller to generate discrete
samples of a signal to properly filter and form the discrete
pulses. Specifically, Kronmuller teaches that a FIR filter
should be connected between an ADC and an output stage of
the sampling circuit so that any interference frequencies and
interfering frequency ranges can be suppressed (see e.g.,
Kronmuller -- Figure 1, References 3 and 4, column 3, lines
27-34).
(Ans. 12.)
This reasoning is consistent with Appellant’s own description of the
knowledge of a person of ordinary skill in the art at the time of the
invention. Appellant states that it was known that power factor controllers
produced a ripple that complicated correction of the output voltage. Spec.
¶¶ 7-9. The skilled artisan, therefore, would have been motivated to use
Kronmüller’s FIR filter to remove the ripple from Zhan’s feedback loop.
Second, Appellant argues that the combination of Zhang and
Kronmüller “do not teach or teach or suggest a controller that is capable to
‘use the received signal [associated with the feedback discrete samples
generated by the FIR filter] to generate a control signal to provide power
factor correction and to regulate the output voltage of the switching power
converter.’” (App. Br. 15.)
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We are not persuaded by this argument. Zhang describes a controller
that performs the stated functions using an unfiltered signal. Zhang ¶¶ 0040,
0117. We agree with the Examiner that it was within the level of skill in the
art to modify Zhang’s controller to continue to perform these functions using
the filtered signal created by adding Kronmüller’s FIR filter to Zhang’s
circuit. Appellant has neither pointed to any evidence nor provided a
persuasive explanation that contradicts this finding. (See Reply Br. 3-4.)
The need for such modifications does not negate the obviousness conclusion.
See In re Keller, 642 F.2d 413, 425 (CCPA 1981) (“The test for obviousness
is not whether the features of a secondary reference may be bodily
incorporated into the structure of the primary reference . . . .”).
Third, Appellant’s assertion of unexpected results is attorney
argument, unsupported by evidence either of what the results are or of their
unexpected nature. (App. Br. 16.) Due to the lack of actual evidence,
Appellant’s argument is inadequate. See In re Mayner, 104 F.3d 1339, 1343
(Fed. Cir. 1997) (requiring Appellant to establish the existence of
unexpected results with evidence); In re Freeman, 474 F.2d 1318, 1324
(CCPA 1973) (requiring Appellant to establish both the difference in results
and their unexpected nature). Furthermore, the Examiner has provided a
persuasive explanation of why the results are not unexpected. (Ans. 14.)
We, therefore, are not persuaded by Appellant’s allegation of unexpected
results.
In view of the foregoing, we affirm the rejection of claims 1, 2, 4-6, 8,
9, 11-14, 16-19, 21, 22, and 24-26 as obvious over the combination of Zhang
and Kronmüller.
Rejections 2-4. Appellant’s arguments for reversal of these rejections
are based upon the alleged defects in the combination of Zhang and
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Kronmüller discussed above. (App. Br. 18-19.) Because we did not find
those arguments persuasive, we also affirm these rejections.
CONCLUSION
For the reasons set forth above, we affirm the rejections of claims 1-
26 of the ’276 Application.

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

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