Ex Parte Hirst

Board of Patent Appeals and Interferences

Jul 26, 2011

10780927 (B.P.A.I. Jul. 26, 2011)

UNITED STATES PATENT AND TRADEMARK OFFICE
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BEFORE THE BOARD OF PATENT APPEALS
AND INTERFERENCES
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Ex parte B. MARK HIRST
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Appeal 2009-007120
Application 10/780,927
Technology Center 2800
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Before ALLEN R. MACDONALD, ERIC S. FRAHM, and
JASON V. MORGAN, Administrative Patent Judges.

MORGAN, Administrative Patent Judge.

DECISION ON APPEAL
Appeal 2009-007120
Application 10/780,927

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STATEMENT OF THE CASE
Introduction
This is an appeal under 35 U.S.C. § 134(a) from the Examiner’s final
rejection of claims 1, 7 – 9, 17 – 20, 31 – 59. We have jurisdiction under 35
U.S.C. § 6(b).
Exemplary Claims
1. An apparatus comprising:
an AC switching circuit;
a control circuit coupled to the AC switching circuit; and
a biasing snubber circuit coupled to the switching circuit and
the control circuit to capture energy from a circuit switched by
the switching circuit and to provide at least a portion of the
captured energy to bias the control circuit.
31. A snubber circuit comprising:
a first energy storage device;
circuitry coupled to the first energy storage device to facilitate
capturing, by the first energy storage device, energy of a
switching circuit and to facilitate resetting of the first energy
storage device; and
a second energy storage device coupled to the first energy
storage device to store the captured energy and to provide at
least a portion of the captured energy to a control circuit.
(App. Br. 24 and 28 – 29; Claims App’x).
Appeal 2009-007120
Application 10/780,927

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Rejections and Appellant’s Contentions
Appellant contends that the Examiner erred in rejecting claim 1 under
35 U.S.C. § 102(b) as being anticipated by Guerrera (US 5,923,152)
because:
1

First, the snubber circuit of Guerrera is NOT coupled to
an AC switching circuit. In contrast, the snubber circuit
disclosed by Guerrera is merely connected to a DC switching
circuit. . . . [I]f the circuit shown in Figure 2 of Guerrera were
alternatively employed with an AC switching circuit, during the
negative half cycle of the AC waveform, diode 66 or switch 40
would experience an uncontrolled voltage causing diode 66 or
switch 40 to be destroyed.
Second, Guerrera fails to disclose an apparatus having a
snubber circuit that captures energy from a circuit switched by
switching circuit and that provides at least a portion of the
captured energy to bias a control circuit. In contrast, Guerrera
merely discloses a circuit wherein energy captured by a snubber
circuit is retransmitted back to its load. The captured energy is
not used to bias a control circuit.
(App. Br. 11 – 12).
Appellant contends that the Examiner erred in rejecting claim 8 under
35 U.S.C. § 103(a) as being unpatentable over Guerrera because:
First, the Examiner has failed to indicate what specific
parts one of ordinary skill in the art would allegedly “reverse”
in Guerrera.
Second, any rearrangement of “parts” in the circuit of
Guerrera would clearly change the principle of operation and
attended functioning of the circuit of Guerrera.
(App. Br. 16).

1
Separate patentability is not specifically argued for dependent claims 7, 9,
and 17 – 20.
Appeal 2009-007120
Application 10/780,927

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Appellant contends that the Examiner erred in rejecting claim 31
under 35 U.S.C. § 102(b) as being anticipated by Church (US 6,055,161)
because:
First, as one of ordinary skill in the art would recognize,
the boost converter circuit shown in Figure 2 of Church (relied
upon by the Examiner to reject Claim 31) does not transfer
captured energy from a switching circuit from a first energy
storage device to second energy storage device. Captured
energy is not transferred from capacitor 102 to capacitor 104 or
vice versa. In contrast, with the circuit shown in Figure 2,
capacitors 102 and 104 are simultaneously charged or
discharged. The circuit shown in Figure 5 also simultaneously
charges and discharges its capacitors.
Second, Church does not provide captured energy to a
control circuit. In contrast, any captured energy is provided to
the load.
(App. Br. 13).
Appellant contends that the Examiner erred in rejecting claim 47
under 35 U.S.C. § 103(a) as being unpatentable over Guerrera and Dan-
Harry (US 5,485,365) because:
The Examiner cannot even point to what he considers to
be the current limiting device or where Dan-Harry allegedly
switches the current-limiting device into circuit when a
snubbing capacitor is reset. The Examiner merely makes the
conclusory and unsupported statement that “Dan-Harry teaches
utilization of the similar technique for current limiting device
(figure 2).” (Office Action dated December 31, 2007, page 5).
(App. Br. 19).
Appellant contends that the Examiner erred in rejecting claim 52
under 35 U.S.C. § 102(b) as being anticipated by Guerrera because:
[C]laim 52 further recites that the switching circuit
includes a first transistor and a second transistor, the first
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transistor and a second transistor having source terminals
connected in common.
Guerrera fails to disclose first and second transistors
having source terminals connected in common. In direct
contrast, Guerrera requires that its switching devices be
connected source to drain. For example, switching devices 40
and 46 of Figure 2 are connected source to drain. Switching
devices 40 and 46 to not have source terminals connected in
common.
(App. Br. 12).

ISSUES
1. Did the Examiner err in finding that Guerrera teaches a biasing
snubber circuit coupled to an AC switching circuit?
2. Did the Examiner err in finding that Guerrera teaches a biasing
snubber circuit captures energy from a circuit switched by a switching
circuit and provides a portion of the captured energy to bias a control
circuit?
3. Did the Examiner err in finding that Guerrera teaches or suggests
the recitations of claim 8?
4. Did the Examiner err in finding that Church teaches capturing
energy with a first energy storage device and storing the captured energy
with a second energy storage device?
5. Did the Examiner err in finding that the combination of Guerrera
and Dan-Harry teaches or suggests an AC switching circuit configured to
switch a current limiting device into circuit when a snubbing capacitor is
reset?
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6. Did the Examiner err in finding that Guerrera teaches a first
transistor and a second transistor having source terminals connected in
common?

ANALYSIS
We have reviewed the Examiner’s rejections in light of Appellant’s
arguments (Appeal Brief and Reply Brief) that the Examiner has erred.
We disagree with Appellant’s conclusions with respect to claims 1, 7,
9, 17 – 20, 46, and 52. With respect to these claims, 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 Appellant’s Appeal Brief. Except with
respect to claims 8, 31 – 51, and 53 – 59, we concur with the conclusions
reached by the Examiner.
(1) Whether the Examiner erred in finding that Guerrera teaches a biasing
snubber circuit coupled to an AC switching circuit
Guerrera discloses that “a rectified AC signal is supplied to the circuit
[of Figure 2] at input terminals 32,34” (col. 2, ll. 37 – 38). We do not agree
with Appellant that the claimed “AC switching circuit” must receive an
unrectified (as opposed to a rectified) AC signal. Also, we do not agree with
Appellant that there is a patentable distinction between an “AC switching
circuit” and a “rectified AC switching circuit.” Moreover, we do not agree
with Appellant that the circuit shown in Guerrera (Fig. 2) is not employable
as an AC switching circuit. We also do not agree with Appellant’s assertion
that such use would destroy diode 66 or switch 40.
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Accordingly, the Examiner has not erred in the rejection of claim 1
and dependent claims 7 – 9, 17 – 20, and 46 – 51.
(2) Whether the Examiner erred in finding that Guerrera teaches a biasing
snubber circuit captures energy from a circuit switched by a switching
circuit and provides a portion of the captured energy to bias a control
circuit
We do not agree with Appellant that there is a patentable distinction
between Guerrera’s teaching of reducing losses and the claimed control
circuit biasing. Accordingly, the Examiner has not erred in the rejection of
claim 1 and dependent claims 7 – 9, 17 – 20, and 46 – 51.
(3) Whether the Examiner erred in finding that Guerrera teaches or suggests
the recitations of claim 8
We agree with Appellant that the Examiner erred with respect to this
issue and therefore we do not sustain the Examiner’s rejection of claim 8.
(4) Whether the Examiner erred in finding that Church teaches capturing
energy with a first energy storage device and storing the captured energy
with a second energy storage device
Claim 31 recites both “capturing, by [a] first energy storage device,
energy” and “a second energy storage device . . . to store the captured
energy” (Claims App’x 28 – 29) (emphasis added). We agree with Appellant
that these recitations require a transfer of energy from the first energy
storage device to the second energy storage device.
Appellant’s application discloses the use of capacitors as the claimed
energy storage devices (App. Br. 3; Spec. Figs. 9 – 14); however, we do not
agree with the Examiner that Church’s capacitors (Fig. 2, refs.102, 104)
function in the claimed manner. Church discloses that “[i]n operation, the
capacitors 102, 104 have generally equal values” (col. 7, ll. 56 – 57). The
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capacitors having “generally equal values” is evidence that energy is not
transferred from one capacitor to another in Church.
Accordingly, we agree with Appellant that the Examiner erred with
respect to this issue and therefore we do not sustain the Examiner’s rejection
of claim 31, claims 39 and 43 which have similar claim recitations, and
dependent claims 32 – 38, 40 – 42, 44, and 45.
(5) Whether the Examiner erred in finding that the combination of Guerrera
and Dan-Harry teaches or suggests an AC switching circuit configured to
switch a current limiting device into circuit when a snubbing capacitor is
reset
We agree with Appellant that the Examiner erred with respect to this
issue and therefore we do not sustain the Examiner’s rejection of claim 47,
claim 53 which has similar recitations, and dependent claims 48 – 51 and 54
– 59.
(6) Whether the Examiner erred in finding that Guerrera teaches a first
transistor and a second transistor having source terminals connected in
common
We do not agree with Appellant that Guerrera fails to show two
transistors having source terminals connected in common. Based on a
reasonably broad interpretation of “connected in common,” it is sufficient
that Guerrera disclose source terminals of the transistors being connected to
each other, even if other components are part of that connection. Guerrera
depicts two transistors 40 and 46 having source terminals connected
together, with diodes 54 and 66, capacitor 58, and inductor 44 as part of that
connection (Fig. 2).
Because Guerrera’s transistors 40 and 46 are connected in common,
we do not agree that there was any error with respect to this issue in the
Examiner’s rejection of claim 52. We also do not agree that there was any
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error in the Examiner’s rejection of claim 46, which is rejected based on the
teachings and suggestions of Guerrera (Ans. 5) and which has similar
recitations as those found in claim 52.

CONCLUSIONS OF LAW
Based on the findings of facts and analysis above, we conclude that
claims 1, 7, 9, 17 – 20, and 52 are unpatentable because the Examiner did
not err in finding:
1. that Guerrera teaches a biasing snubber circuit coupled to an AC
switching circuit;
2. that Guerrera teaches a biasing snubber circuit captures energy
from a circuit switched by a switching circuit and provides a portion of the
captured energy to bias a control circuit; and
3. that Guerrera teaches a first transistor and a second transistor
having source terminals connected in common.
We conclude that claims 8, 31 – 51, and 53 – 59 have not been proven
unpatentable because the Examiner erred in finding:
1. that Guerrera teaches or suggests the recitations of claim 8;
2. that Church teaches capturing energy with a first energy storage
device and storing the captured energy with a second energy storage device;
and
3. that the combination of Guerrera and Dan-Harry teaches or
suggests an AC switching circuit configured to switch a current limiting
device into circuit when a snubbing capacitor is reset.
Appeal 2009-007120
Application 10/780,927

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DECISION
We affirm the Examiner’s decisions rejecting claims 1, 7, 9, 17 – 20,
46, and 52.
We reverse the Examiner’s decisions rejecting claims 8, 31 – 51, and
53 – 59.
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-IN-PART

ELD