Ex parte BARLAGE

Board of Patent Appeals and Interferences

Oct 28, 1999

08200123 (B.P.A.I. Oct. 28, 1999)

Application for patent filed February 22, 1994.1
1
THIS OPINION WAS NOT WRITTEN FOR PUBLICATION
The opinion in support of the decision being entered today
(1) was not written for publication in a law journal and
(2) is not binding precedent of the Board.
Paper No. 17
UNITED STATES PATENT AND TRADEMARK OFFICE
_____________
BEFORE THE BOARD OF PATENT APPEALS
AND INTERFERENCES
_____________
Ex parte FRANCIS M. BARLAGE
_____________
Appeal No. 1997-0288
Application 08/200,1231
______________
ON BRIEF
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Before HAIRSTON, MARTIN, and GROSS, Administrative Patent
Judges.
HAIRSTON, Administrative Patent Judge.
DECISION ON APPEAL
This is an appeal from the final rejection of claims 1
through 9.
Appeal No. 1997-0288
Application No. 08/200,123
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The disclosed invention relates to a load driver that
produces a variable output voltage at a substantially constant
current.
Claim 1 is illustrative of the claimed invention, and it
reads as follows:
1. A load driver adapted to produce a variable voltage
output at substantially constant current, comprising in
combination:
a transformer including primary and secondary windings,
the secondary winding including first and second ends;
an ouput branch to be connected to a reactive and
inductive load, and connected to the secondary winding; the
output branch including a resistor aside from the load;
a transistor connected to the primary winding so as to be
operable to modulate current flow therethrough, the transistor
including a control input;
a pulse-width modulator connected to the resistor so as
to be operable to sense current flow therethrough, and
connected to the control input of the transistor so as to be
operable to modulate current flow therethrough in response to
the current flow through the resistor, to produce a
substantially constant current, variable voltage output.
The reference relied on by the examiner is:
Saito et al. (Saito) 5,297,014 Mar. 22,
1994
(filed Jan. 3, 1992)
Claims 1 through 9 stand rejected under 35 U.S.C. § 103
as being unpatentable over Saito.
Appeal No. 1997-0288
Application No. 08/200,123
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Appeal No. 1997-0288
Application No. 08/200,123
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Reference is made to the briefs and the answer for the
respective positions of the appellant and the examiner.
OPINION
The obviousness rejection of claims 1 through 9 is
reversed.
According to the examiner (Answer, pages 3 and 4):
Saito et al discloses the invention essentially
as claimed including a transformer (T1), diode (Q3),
resistor (R6), a transistor (Q1), a pulse-width
modulator (3) and a voltage dividers [sic] (R2-R4)
as claimed except for the [sic] obtaining the output
of a substantially constant current, variable
voltage output. However, it would have been obvious
to one having ordinary skill in the art at the time
the invention was made to obtain the output of a
substantially constant current, variable voltage
output which is merely a designer’s choice, since
all of the essential elements for a constant
current, variable voltage device of the present
invention are present in the cited reference.
In response to the rejection, appellant argues (Brief,
page 4) that “[i]n no manner can a circuit breaker, or even
the ten circuit breakers of Saito, suggest a continuously
operational control arrangement that finely controls output
current to a constant level” because “Saito’s arrangement
operates only to modify or lower the maximum current
threshold, rather than creating a constant current output.”
Appeal No. 1997-0288
Application No. 08/200,123
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In short, appellant argues (Brief, page 5) that “[i]t cannot
be mere . . . ‘design choice’
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Application No. 08/200,123
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to change a constant voltage, variable current output power
system (Saito) into the opposite.”
We agree with all of appellant’s arguments. Saito
discloses a current detection circuit 7 (Figure 1) that
receives an output current that flows through current
detection resistor R6. The output from the current detection
circuit 7 is supplied via photocoupler Q5 to primary current
detection means A. According to Saito (column 6, lines 17
through 26):
If, therefore, there is no input from the
secondary current detection means B, the threshold
value for current detection is set at a level at
which a peak current can be supplied, as shown in
FIG. 2A. In contrast to this, if an input from the
secondary current detection means B is received, the
detection level of the primary current detection
means A is shifted downward to limit a current, as
shown in FIG. 2B. In this embodiment, the
transistor portion of the photocoupler Q5 serves as
a variable resistance element.
Although Saito’s circuit appears to be similar to the
circuit disclosed by appellant, Saito’s circuit is designed
and operated “to maintain the output voltage at a constant
value” (column 11, lines 17 and 18), which is the very
antithesis of the claimed invention. Accordingly, we agree
with appellant (Brief, page 5) that “[i]n Fig. 2B of Saito, it
Appeal No. 1997-0288
Application No. 08/200,123
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is clear that output current varies as the load changes, being
limited only when reaching its peak value.” In summary, we
agree with appellant (Reply Brief, page 2) that the examiner
has resorted to the use of impermissible hindsight to
demonstrate the obviousness of the claimed invention.
DECISION
The decision of the examiner rejecting claims 1 through 9
under 35 U.S.C. § 103 is reversed.
REVERSED
KENNETH W. HAIRSTON )
Administrative Patent Judge )
)
)
) BOARD OF PATENT
JOHN C. MARTIN ) APPEALS AND
Administrative Patent Judge ) INTERFERENCES
)
)
)
ANITA PELLMAN GROSS )
Administrative Patent Judge )
KWH:svt
Appeal No. 1997-0288
Application No. 08/200,123
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Robert Desmond, Esquire
Allied Signal Inc.
Law Department, M/S 36-2-76000
2525 West 190th Street
Torrance, CA 90504-6099