Ex Parte Hirst

Board of Patent Appeals and Interferences

Mar 11, 2011

10846451 (B.P.A.I. Mar. 11, 2011)

UNITED STATES PATENT AND TRADEMARK OFFICE
____________

BEFORE THE BOARD OF PATENT APPEALS
AND INTERFERENCES
____________

Ex parte MARK HIRST
____________

Appeal 2009-009164
Application 10/846,451
Technology Center 2800
____________

Before MAHSHID D. SAADAT, ROBERT E. NAPPI,
and BRADLEY W. BAUMEISTER Administrative Patent Judges.

SAADAT, Administrative Patent Judge.

DECISION ON APPEAL1

1 The two month time period for filing an appeal or commencing a civil
action, as recited in 37 C.F.R. § 1.304 or for filing a request for rehearing as
recited in 37 C.F.R. § 41.52, begins to run from the “MAIL DATE” (paper
delivery mode) or the “NOTIFICATION DATE” (electronic delivery mode)
shown on the PTOL-90A cover letter attached to this decision.
Appeal 2009-009164
Application 10/846,451

2
Appellant appeals under 35 U.S.C. § 134(a) from a Final Rejection of
claims 1, 5, 6, 8-20, 25, 28-32, and 35. Claims 21-24 are withdrawn from
consideration and claims 2-4, 7, 26, 27, 33, and 34 are cancelled. We have
jurisdiction under 35 U.S.C. § 6(b).
We affirm.

STATEMENT OF THE CASE
Appellant’s invention relates to an apparatus and method for
alternating current (AC) power control by using metal oxide semiconductor
field effect transistor (MOSFET) switching devices 142, 144 (see Fig. 1). A
switch control circuit 140 selectively turns on the MOSFETs permitting
current flow through a load 130. (Spec. ¶ [0025]). Claims 1 and 25, which
are illustrative of the invention, read as follows:
1. An apparatus comprising:
a switching circuit comprising:
a first Field Effect Transistor (FET) having a first source,
a first gate and a first drain;
a second FET having a second source coupled to said
first source and a second gate coupled to said first gate;
a first diode having a first anode coupled to said first
source and a first cathode coupled to said first drain; and
a second diode having a second anode coupled to said
second source and a second cathode coupled to said second
drain;
a load coupled to said switching circuit; and
a control circuit coupled to said switching circuit,
wherein said control circuit is configured to facilitate
controllable current delivery through the switching circuit to
said load and wherein said controllable current delivery
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comprises linear duty ratio current delivery during a start up
period of said load.
25. A method of control of alternating current in a circuit
comprising:
during a first state of the circuit, controlling a plurality of
MOSFETs to permit alternating current flow through the circuit
by enabling a flow of alternating current through the plurality
of MOSFETs; and
during a second state of the circuit, controlling the
plurality of MOSFETs to inhibit alternating current flow
through the circuit by disabling the flow of alternating current
through the plurality of MOSFETs such that when a voltage
across the plurality of MOSFETs is at a positive polarity, a first
explicit antiparallel diode corresponding to a first MOSFET
inhibits current flow through the circuit and, when the voltage
across the plurality of MOSFETs is at a negative polarity, a
second explicit antiparallel diode corresponding to a second
MOSFET inhibits current flow through the circuit, wherein the
first and second state of the circuit are modulated with a
variable frequency.
The Examiner relies on the following prior art in rejecting the claims:
Apfelbeck US 4,375,524 Nov. 2, 1982
Sugawara US 5,635,826 Jun. 3, 1997
Cosan US 5,923,143 Jul. 13, 1999
Zhu US 6,587,356 B2 Jul. 1, 2003
Saggini US 6,873,140 B2 Mar. 29, 2005
Claims 1, 5, 6, 8-17, 19, 20, 29-32, and 35 stand rejected under
35 U.S.C. § 103(a) as unpatentable over Sugawara in view of Zhu.
Claim 18 stands rejected under 35 U.S.C. § 103(a) as unpatentable
over Sugawara and Zhu in view of Apfelbeck.
Claims 25 and 28 stand rejected under 35 U.S.C. § 103(a) as
unpatentable over Sugawara in view of Saggini.
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Rather than repeat the arguments here, we make reference to the
Briefs (App. Br. filed Jun. 16, 2008; Reply Br. filed Nov. 17, 2008) and the
Answer (mailed Sep. 16, 2008) for the respective positions of Appellant and
the Examiner. Only those arguments actually made by Appellant have been
considered in this decision. Arguments that Appellant did not make in the
Briefs have not been considered and are deemed to be waived. See
37 C.F.R. § 41.37(c)(1)(vii).

ISSUES
The primary reference cited by the Examiner for all of the rejections is
Sugawara which remains uncontested by Appellant. The salient issues
presented by Appellant’s arguments are as follows:
Is Zhu properly combined with Sugawara, rendering obvious a
“controllable current delivery compris[ing] linear duty ratio current delivery
during a start up period of [a] load,” as recited in claim 1?
Is Saggini properly combined with Sugawara, rendering obvious “[a]
first and second state of [a] circuit [being] modulated with a variable
frequency,” as recited in claim 25?

ANALYSIS
Claim 1
The Examiner cites Zhu as teaching a linear duty ratio current
delivery during a start up period (Ans. 5). Appellant contends that the
combination of Zhu with Sugawara is inapplicable because a person of
ordinary skill in the art would not be motivated to, or able to, combine the
feature of linearly ramping up the duty cycle from Zhu’s DC-to-DC
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converter with Sugawara’s AC-to-DC (see App. Br. 8-9) or AC-to-AC
converter (see Ans. 10; Reply Br. 6). Appellant further contends that such a
combination could only be made following the teachings of Appellant’s
disclosure (App. Br. 9) and that such a combination would render Sugawara
unsatisfactory for its intended purpose or change its principle of operation
(App. Br. 9-10).
The Examiner correctly states that:
the test for obviousness is not whether the features of a
secondary reference may be bodily incorporated into the
structure of the primary reference; nor is it that the claimed
invention must be expressly suggested in any one or all of the
references. Rather, the test is what the combined teachings of
the references would have suggested to those of ordinary skill
in the art.
(Ans. 9 (citing In re Keller, 642 F.2d 413, 425 (CCPA 1981))). The
Examiner explains that AC or DC conversion is irrelevant to the
applicability of Zhu, because “Zhu et al. was cited to teach that it is common
practice as well as old and well known to those of ordinary skill in the art to
ramp up the duty cycle of a switching circuit in order to avoid inrush
current” (Ans. 11). The Examiner cites Cosan as further evidence that the
problems of inrush currents are known in the art (Ans. 12) and that
progressively changing the amount of current drawn by a load during a
startup procedure to alleviate the problems of inrush currents is also known
(Ans. 13). We note that Cosan discloses an AC-to-AC converter (Cosan Fig.
1a; Abstract).
Appellant’s arguments are unpersuasive. We find the Examiner’s
findings and explanations (Ans. 4-6, 8-14, 18) to be reasonable and we adopt
them as our own.
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By way of emphasis, we find the Examiner has provided a sufficient
rationale explaining the motivation for the combination and note that the
Examiner’s reference to Cosan (Ans. 12-13) to supplement the findings and
explanations, which was uncontested in Appellant’s Reply Brief, further
bolsters the Examiner’s rationale.
“The obviousness analysis cannot be confined by a formalistic
conception of the words teaching, suggestion, and motivation, or by
overemphasis on the importance of published articles and the explicit
content of issued patents.” KSR Int’l Co. v. Teleflex Inc., 550 U.S. 398, 419
(2007). We find that the combination described by the Examiner would be
within the capabilities of a person of ordinary skill in the art. “[A fact
finder] can take account of the inferences and creative steps that a person of
ordinary skill in the art would employ.” Id. at 418. “A person of ordinary
skill is also a person of ordinary creativity, not an automaton.” Id. at 421.
Further, we find that the claimed invention is a combination of a familiar
switching circuit, as disclosed by Sugawara, with a familiar control strategy
for alleviating the effects of inrush currents, as disclosed by Zhu, according
to known methods, that does no more than yield predictable results, see id. at
416, that can be implemented by a person of ordinary skill in the art, see id.
at 417.
Accordingly, we sustain the rejection of claim 1, and of claim 29,
which was argued together with claim 1 (App. Br. 7). We also sustain the
rejections of claims 5, 6, 8-20, 30-32, and 35, which depend from claim 1 or
29 and were argued relying solely on the arguments made for claims 1 and
29 (App. Br. 10).
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Claim 25
The Examiner cites Saggini as disclosing modulating the MOSFET
circuit between two states with a variable frequency (Ans. 7-8) and states
that the motivation for the combination is improved stability (Ans. 7).
Appellant argues that “[b]ecause the circuit disclosed by Sugawara is
already inherently stable, one of ordinary skill in the art would not modify
Sugawara based upon Saggini for this reason” (App. Br. 11 (emphasis
omitted); Reply Br. 2). Appellant further argues:
the Examiner (1) mischaracterizes the facts by arguing that
Applicant has merely discovered another inherent advantage
resulting from the prior art circuit, (2) improperly attempts to
require Appellant to recite the benefits of the claimed structure
in the claims, (3) improperly attempts to require Appellants
[sic] to provide “proof” for the evident operating characteristic
of Sugawara and (4) attempts to support the alleged
modification of Sugawara in view of Saggini based upon
benefits discussed in Saggini that have nothing to do with the
feature the Examiner is attempting to incorporate into
Sugawara.
(App. Br. 11-12; Reply Br. 3).
We are not persuaded by Appellant’s arguments. The Examiner’s
findings and explanations (Ans. 6-8, 14-19) are reasonable and we adopt
them as our own.
For emphasis, we note that, as the Examiner pointed out, Appellant’s
arguments rely on alleged differences between the content of the prior art
and features of the invention from the Specification that are not found in the
claim, such as linear power characteristics (Ans. 15; App. Br. 12; Reply Br.
2-3). Such unclaimed features may not be read into the claims from the
Specification. See In re Van Guens, 988 F.2d 1181, 1184 (Fed. Cir. 1993).
Furthermore, we observe that the capability of incorporating a feature into a
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claimed invention can be an advantage which Appellant may have
recognized, see Ex parte Obiaya, 227 USPQ 58, 60 (BPAI 1985), but it can
only distinguish the claim from the prior art, if it does distinguish, by
reciting the feature in the claim, see Van Guens, 988 F.2d at 1184.
Furthermore, Appellant’s conclusory argument that Sugawara is inherently
stable is made without reference to any evidence in the record and, therefore,
has little persuasive weight. Accordingly, as the Examiner has articulated at
least one reasonable rationale for the combination of Sugawara and Saggini,
Appellant’s arguments regarding the Examiner’s reliance on other benefits
discussed in Saggini (Reply Br. 3) are also unpersuasive.
The Examiner points (Ans. 16) to Sugawara’s disclosure of a variable
resistor for frequency control of the controller (i.e., switch control circuit)
(Sugawara Fig. 3; col. 6, ll. 2-3) as providing a further suggestion for the
combination of Sugawara and Saggini. Appellant’s Reply Brief does not
contest this further explanation by the Examiner.
We also find that the claimed invention is a combination of a familiar
switching circuit, as disclosed by Sugawara, with a familiar control
parameter for modulating the switches, as disclosed by Saggini, according to
known methods, that does no more than yield predictable results, see KSR,
550 U.S. at 416, that can be implemented by a person of ordinary skill in the
art, see id. at 417.
Accordingly, we sustain the rejection of claim 25, and of claim 28,
which depends from claim 25 and was argued relying solely on the
arguments for claim 25 (App. Br. 14).

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Application 10/846,451

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ORDER
The decision of the Examiner rejecting claims 1, 5, 6, 8-20, 25, 28-32,
and 35 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). See 37 C.F.R.
§ 1.136(a)(1)(iv) (2010).

AFFIRMED

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