Ex Parte Sakaguchi

Board of Patent Appeals and Interferences

Mar 28, 2012

11637178 (B.P.A.I. Mar. 28, 2012)

UNITED STATES PATENT AND TRADEMARKOFFICE
UNITED STATES DEPARTMENT OF COMMERCE
United States Patent and Trademark Office
Address: COMMISSIONER FOR PATENTS
P.O. Box 1450
Alexandria, Virginia 22313-1450
www.uspto.gov
APPLICATION NO. FILING DATE FIRST NAMED INVENTOR ATTORNEY DOCKET NO. CONFIRMATION NO.
11/637,178 12/12/2006 Makoto Sakaguchi NEC06182US 8912
21254 7590 03/29/2012
MCGINN INTELLECTUAL PROPERTY LAW GROUP, PLLC
8321 OLD COURTHOUSE ROAD
SUITE 200
VIENNA, VA 22182-3817
EXAMINER
ENGLUND, TERRY LEE
ART UNIT PAPER NUMBER
2816
MAIL DATE DELIVERY MODE
03/29/2012 PAPER
Please find below and/or attached an Office communication concerning this application or proceeding.
The time period for reply, if any, is set in the attached communication.
PTOL-90A (Rev. 04/07)
UNITED STATES PATENT AND TRADEMARK OFFICE
____________________

BEFORE THE BOARD OF PATENT APPEALS
AND INTERFERENCES
____________________

Ex parte MAKOTO SAKAGUCHI
____________________

Appeal 2010-002277
Application 11/637,178
Technology Center 2800
____________________

Before RICHARD M. LEBOVITZ, KARL D. EASTHOM, and
JEFFREY B. ROBERTSON, Administrative Patent Judges.

ROBERTSON, Administrative Patent Judge.

DECISION ON APPEAL

Appeal 2010-002277
Application 11/637,178

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STATEMENT OF CASE
Appellant appeals under 35 U.S.C. § 134 from a rejection of claims 1,
5, 9, 11, and 12. We have jurisdiction under 35 U.S.C. § 6(b).
We REVERSE.

THE INVENTION
The claims are directed to a current switching circuit capable of high-
speed switching operation and suitable for connection with a current driving
element such as a laser diode. (Spec. 1, ll. 5-8.)
Claim 1, reproduced below, is illustrative of the claimed subject
matter:
1. A current switching circuit that adds additional current to
an input current of a current mirror at a rising edge of an output
current of the current mirror, in accordance with an intensity of
the output current of the current mirror, the current switching
circuit comprising:
a metal oxide semiconductor (MOS) transistor outputting
the additional current upon receiving an ON potential at a gate
terminal, a slope of a leading edge waveform of a voltage
provided to the gate terminal being controlled in accordance
with the intensity of the output current.
(Appeal Brief, Claims Appendix1 12.)

Claim 12 also is an independent claim and it requires, inter alia, “a
variable current source.” (App. Br., Claims App’x 15.)

1 Appeal Brief filed April 24, 2009, as amended by Appeal Brief filed June
3, 2009, hereinafter “App. Br.” and “Claims App’x,” respectively.
Appeal 2010-002277
Application 11/637,178

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THE REJECTION
I. The Examiner rejected claims 1, 5, 9, 11, and 12 under
35 U.S.C. § 102(e) as anticipated by Mizuno et al. (US
7,075,338 B2, issued July 11, 2006). (Examiner’s Answer,
dated July 29, 2009, “Ans.” 3-5.)

ISSUE
The Examiner found that the circuit disclosed in Figure 3 of Mizuno
anticipates Appellant’s claims. (Ans. 3-5.) Specifically, the Examiner
found that one of ordinary skill in the art would understand that in Mizuno,
the slope of a leading edge waveform of the voltage provided to the gate
terminal of transistor 32 is effectively controlled with the intensity of the
output current. (Ans. 3.) The Examiner explained that transistor 32 will
begin to conduct once the leading edge waveform of the voltage, provided
by one-shot circuit 31, reaches the threshold voltage of the transistor, and the
transistor will remain conducting as long as that waveform remains above
the transistor’s threshold. (Ans. 3.) Regarding claim 12, the Examiner
found that Mizuno’s current source CS1 is a variable current source. (Ans.
4-5.)
Appellant argues that Mizuno fails to disclose that the slope of the
leading edge waveform is controlled in accordance with the intensity of the
output current. (App. Br. 6.) Appellant contends that the slope of the
waveform at the gate of transistor 32 is controlled by the one-shot circuit 31,
such that there is no relationship between this voltage and the intensity of the
output current I2, as would be required to satisfy claim 1. (App. Br. 8.)
Regarding claim 12, Appellant contends that Mizuno’s current source (CS1)
is controlled by a fixed reference voltage VR, such that Mizuno’s current
Appeal 2010-002277
Application 11/637,178

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source is not variable. (See Reply Brief, dated September 4, 2009, “Reply
Br.” 2-3.)
Therefore, the dispositive issue on appeal is:
Whether the Examiner erred in finding that Mizuno discloses “a slope
of a leading edge waveform of a voltage provided to the gate terminal being
controlled in accordance with the intensity of the output current” or a
variable current source as recited in the claims?

ANALYSIS
The Examiner’s position appears to be that in Mizuno Figure 3, if
input current I1 changes, the output current I2 changes in the current mirror,
and that this relationship ultimately satisfies claim 1. (Ans. 6.) The
Examiner also stated that one of ordinary skill in the art would have
understood that adding additional current to an input current of a current
mirror at a rising edge of an output current of the current mirror and a slope
of a leading edge waveform of a voltage provided to the gate terminal being
controlled “in accordance with an intensity of the output current” includes
turning the input current on and off, and that subsequently increasing the
input current from zero (i.e. adding additional input current), presumably by
turning the input current “on,” in turn varies the output current in accordance
with the “additional” input current. (Ans. 6.)
However, neither Appellant’s Specification nor the art of record
supports the Examiner’s position. Rather, in interpreting the claim 1
limitation “voltage provided . . . in accordance with an intensity of the
output current,” in light of Appellant’s Specification, one of ordinary skill in
the art would have understood that such a relationship arises because a
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Application 11/637,178

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variable voltage source, having adjustable voltage settings, is connected in
common to the gate of a transistor outputting the input current and the gate
of a transistor outputting additional current. (Spec. 2, l. 20 – 3, l. 4; Spec. 6,
l. 1 – 7, l. 13; Spec. 8, l. 2.)
In light of the above claim interpretation, we agree with Appellant that
the additional current supplied by Mizuno’s transistor 32 and the slope of the
waveform at the gate of transistor 32 is controlled by the one-shot circuit 31,
which cannot be varied according to the intensity of the output current. (Fig.
3.)
The preponderance of the evidence also supports Appellant’s position
that the voltage source VR in Mizuno’s circuit depicted in Figure 3 is a fixed
voltage source (compare Fig. 3 with Figs. 6, 8, and 16), such that current
source CS1 is a fixed current source. Thus, the Examiner’s response to
Appellant’s argument, which appears to rely on the principle that a constant
magnitude pulsed input current would cause the output current to vary does
not appear applicable here, because Mizuno’s circuit does not have a
variable voltage/current source that controls the input voltage/current.
As such, we agree with Appellant that the Examiner has not shown
the required relationship between the slope of Mizuno’s voltage waveform at
the gate of transistor 32 and the intensity of the output current, as would be
necessary to anticipate claim 1, or that Mizuno’s circuit contains a variable
current source, as required by claim 12.
Accordingly, the Examiner has not established a prima facie case with
respect to the 35 U.S.C. § 102(e) rejection of claims 1 and 12, and for
similar reasons, the remaining independent and dependent claims.

Appeal 2010-002277
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CONCLUSION
Appellant has established that the Examiner erred in finding that
Mizuno discloses “a slope of a leading edge waveform of a voltage provided
to the gate terminal being controlled in accordance with the intensity of the
output current” or a variable current source as recited in the claims.

DECISION
We reverse the Examiner’s rejection of claims 1, 5, 9, 11, and 12
under 35 U.S.C. § 102(e) as anticipated by Mizuno.

REVERSED

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