Ex Parte Lyle

Board of Patent Appeals and Interferences

Oct 26, 2009

10927755 (B.P.A.I. Oct. 26, 2009)

UNITED STATES PATENT AND TRADEMARK OFFICE
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BEFORE THE BOARD OF PATENT APPEALS
AND INTERFERENCES
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Ex parte ROBERT L. LYLE, JR.
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Appeal 2009-002262
Application 10/927,755
Technology Center 2800
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Decided: October 26, 2009
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Before MAHSHID D. SAADAT, ROBERT E. NAPPI, and
CARLA M. KRIVAK, Administrative Patent Judges.

NAPPI, Administrative Patent Judge.

DECISION ON APPEAL

Appeal 2009-002262
Application 10/927,755

This is a decision on appeal under 35 U.S.C. § 134(a) of the final
rejection of claims 1, 4-5, 11, 13, 16, and 20.1 We have jurisdiction under
35 U.S.C. § 6(b).
We affirm the Examiner’s rejection of these claims.

INVENTION
The invention is directed generally to a power supply, and more
specifically to a method and apparatus for combining a high frequency
switching signal and a pulse width modulation (PWM) signal to control AC
power that is supplied to a high voltage device. The high voltage device
may include a cathode fluorescent lamp that is used with liquid crystal
displays for backlighting. In order to control the brightness of the lamp, the
duty cycle of the pulse width modulation signal is controlled. See Spec. 1-3.
Claim 1 is representative of the invention and reproduced below:
1. An apparatus for supplying AC power to a high voltage
device comprising:
a first input port adapted to be coupled to a high frequency
switching signal;
a second input port adapted to be coupled to a low frequency
pulse width modulation signal;
a combining circuit, which is operative to combine, said
high frequency switching signal with said low frequency
pulse width modulation signal, to produce a composite
signal;
a first switching circuit coupled to a first portion of a
primary winding of a transformer, said transformer having a
secondary winding coupled to said high voltage device, said

1 Claims 2-3, 6-10, 14-15, and 17-19 were objected to in the Final Office
Action mailed June 4, 2007 and are not subject to this Appeal. Claim 12
was cancelled in the Amendment filed March 15, 2007.
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first switching circuit being operative to controllably switch
a first current through said primary winding in accordance
with first transitions in said composite signal; and
a second switching circuit coupled to said second portion of
said primary winding of said transformer, said second
switching circuit being operative to controllably switch a
second current through said primary winding in accordance
with second transitions in said composite signal.

REFERENCES
Turner US 6,181,092 B1 Jan. 30, 2001

Hamilton US 6,967,852 B2 Nov. 22, 2005
(filed Dec. 19, 2003)

Emslie US 2004/0233663 A1 Nov. 25, 2004
(filed Nov. 17, 2003)

REJECTIONS AT ISSUE
The Examiner rejected claims 1, 4, 11, 13, 16, and 20 under 35 U.S.C.
§ 103(a) as being unpatentable over Emslie in view of Hamilton. Ans. 3-6.
The Examiner rejected claim 5 under 35 U.S.C. § 103(a) as being
unpatentable over Emslie in view of Hamilton and Turner. Ans. 6-7.

ISSUES
Rejection of claims 1, 4, 11, 13, 16, and 20 under 35 U.S.C. § 103(a) as
being unpatentable over Emslie in view of Hamilton

Claim 1, 4, and 11
Appellant argues on pages 6-10 of the Appeal Brief and pages 1-3 of
the Reply Brief that the Examiner’s rejection of claims 1, 4, and 11 is in
error. We select claim 1 as representative of the group comprising claims 1,
4, and 11 since Appellant does not separately argue these claims with
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particularity. See 37 C.F.R. § 41.37(c)(1)(vii). Appellant argues that it
would not have been obvious to combine Emslie with Hamilton. App. Br. 6;
Reply Br. 1-2. Appellant additionally argues that neither Emslie nor
Hamilton teaches first and second switching circuits that controllably switch
first and second currents, respectively, through the primary winding in
accordance with first and second transitions in the composite signal.
Thus, with respect to claims 1, Appellant’s contentions provide us
with two issues. (1) Has Appellant shown that the Examiner erred in
combining Emslie with Hamilton? (2) Has Appellant shown that the
Examiner erred in finding that Emslie in view of Hamilton teach first and
second switching circuits that controllably switch first and second currents
through the primary winding in accordance with first and second transitions
in the composite signal?
Claims 13, 16, and 20
Appellant argues on pages 11-12 of the Appeal Brief and pages 1-3 of
the Reply Brief that the Examiner’s rejection of claims 13, 16, and 20 is in
error. Independent claim 13 contains similar limitations to claim 1 and
claims 16 and 20 are dependent upon claim 13. Appellant presents the same
arguments discussed above with respect to claim 1. App. Br. 11-12; Reply
Br. 1-3. Thus, with respect to claims 13, 16, and 20, Appellant’s arguments
present us with the same issues as claim 1.

Rejection of claim 5 under 35 U.S.C. § 103(a) as being unpatentable over
Emslie in view of Hamilton and Turner

Appellant argues on page 10 of the Appeal Brief and pages 1-3 of the
Reply Brief that the Examiner’s rejection of claim 5 is in error. Claim 5
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contains similar limitations to claim 1 and is dependent upon claim 1.
Appellant presents the same arguments discussed above with respect to
claim 1. App. Br. 10; Reply Br. 1-3. Thus, with respect to claim 5
Appellant’s arguments present us with the same issues as claim 1.

FINDINGS OF FACT (FF)
Emslie
1. Emslie discloses a backlighting system for LCD screens wherein
the system contains a royer 2 that converts DC voltage to AC
voltage. ¶ [0056] and Fig. 5a.
2. The input to the royer 2 comprises a pulse width modulated or a
modulated or pulsed input DC signal to control the brightness of
the lamps. ¶ [0063] and Fig. 5a.
3. The DC input signal is applied to the royer 2 in superposition and
the signals are logically ANDed together to form a composite
signal. ¶ [0083], ¶ [0089], and Figs. 5a and 5b.
Hamilton
4. Hamilton discloses a power converter 10 that receives a DC
voltage input and provides an AC voltage output. Col. 2, ll. 54-63
and Fig. 1.
5. The power converter 10 contains two switches 30A and 30B and a
current limit circuit 24. Col. 2, ll. 54-67 and Fig. 1.
6. The switches operate “in a push-pull pulse width modulated
mode.” Control pulses SWA and SWB, received from the input
controller 20, control the operation of the switches 30A and 30B.
Col. 3, ll. 3-5 and 19-20, and Fig. 1.
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7. When switch 30A is energized (i.e., control pulse SWA is
received), power is pushed into the first leg 40A of the transformer
primary 40 from IN1, through the switch 30A, and to IN2. When
switch 30B is energized (i.e., control pulse SWB is received),
power is pulled into the second leg 40B of the transformer primary
40 from IN1, through switch 30B, and to IN2. Col. 3, ll. 3-5 and
20-25 and Fig. 1.
8. The current flowing through the switches 30A and 30B when the
switches are turned on is sensed by the current limit circuit 24 and
is compared to a dynamic current limit. Col. 3, ll. 44-52 and Fig.
1.
9. The dynamic current limit is a function of current flowing through
the switches 30A and 30B over time. The longer the time, the
lower the current limit, which allows the initial current demand to
be at a maximum, as is usually the case when a motor is started.
Col. 3, ll. 44-52 and Fig. 1.

PRINCIPLES OF LAW
Office personnel must rely on Appellants’ disclosure to properly
determine the meaning of the terms used in the claims. Markman v.
Westview Instruments, Inc., 52 F.3d 967, 980 (Fed. Cir. 1995) (en banc).
“[I]nterpreting what is meant by a word in a claim is not to be confused with
adding an extraneous limitation appearing in the specification, which is
improper.” In re Cruciferous Sprout Litigation, 301 F.3d 1343, 1348 (Fed.
Cir. 2002) (internal quotation marks and citations omitted; emphasis in
original).
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On the issue of obviousness, the Supreme Court has stated that “[t]he
combination of familiar elements according to known methods is likely to be
obvious when it does no more than yield predictable results.” KSR Int’l Co.
v. Teleflex Inc., 550 U.S. 398, 416 (2007).
“[W]hen the question is whether a patent claiming the combination of
elements of prior art is obvious,” the answer depends on “whether the
improvement is more than the predictable use of prior art elements according
to their established functions.” Id. at 417.
When a work is available in one field of endeavor, design
incentives and other market forces can prompt variations of it,
either in the same field or a different one. If a person of
ordinary skill can implement a predictable variation, § 103
likely bars its patentability. For the same reason, if a technique
has been used to improve one device, and a person of ordinary
skill in the art would recognize that it would improve similar
devices in the same way, using the technique is obvious unless
its actual application is beyond his or her skill. . . . [A] court
must ask whether the improvement is more than the predictable
use of prior art elements according to their established
functions.

Id. at 417. “One of the ways in which a patent’s subject matter can be
proved obvious is by noting that there existed at the time of the invention a
known problem for which there was an obvious solution encompassed by the
patent’s claims.” Id. at 419-420.
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It is well settled that when a claimed product reasonably appears to be
substantially the same as a product disclosed in the prior art, the burden of
proof is shifted to applicant to prove that the prior art product does not
inherently or necessarily possess the characteristics attributed to the claimed
product. In re Spada, 911 F.2d 705, 708-709 (Fed. Cir. 1990); In re Best,
562 F.2d 1252, 1255 (CCPA 1977). “Whether the rejection is based on
‘inherency’ under 35 U.S.C. § 102, on ‘prima face obviousness’ under 35
U.S.C. § 103, jointly or alternatively, the burden of proof is the same, and its
fairness is evidenced by the PTO’s inability to manufacture products or to
obtain and compare prior art products.” Best, 562 F.2d at 1255 (CCPA
1977)
The Examiner bears the initial burden of presenting a prima facie case
of obviousness, and Appellant has the burden of presenting a rebuttal to the
prima facie case. In re Oetiker, 977 F.2d 1443, 1445 (Fed. Cir. 1992).
Appellant has the burden, on appeal to the Board, to demonstrate error in the
Examiner’s position. See In re Kahn, 441 F.3d 977, 985-86 (Fed. Cir.
2006).

ANALYSIS
Rejection of claims 1, 4, 11, 13, 16, and 20 under 35 U.S.C. § 103(a) as
being unpatentable over Emslie in view of Hamilton

Claim 1, 4, and 11
Appellant’s arguments have not persuaded us of error in the
Examiner’s rejection of claims 1, 4, and 11. Appellant argues that since
there is no shortcoming in Emslie, one of ordinary skill in the art would not
have been motivated to combine the features taught by Hamilton with
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Emslie. App. Br. 7-8; Reply Br. 2. However, as stated by the Supreme
Court, a motivation to combine the references is seen as “helpful insight,”
but is not required as long as the combination of the elements of the
references yield predictable results. KSR, 550 U.S. at 416-419.
Emslie discloses a backlighting system for LCD screens wherein the
system contains a royer 2 that converts DC voltage to AC voltage. FF 1.
Hamilton discloses a power converter 10 that comprises a DC voltage input
and provides an AC voltage output. FF 4. Emslie does not specifically
teach the circuit composition of the royer and therefore leaves its details to
the designer. Therefore, we consider using Hamilton’s power converter in
place of Emslie’s royer as nothing more than using known devices to
perform known functions. As such, we find that the combination of Emslie
with Hamilton yields predictable results and Appellant’s arguments are not
found to be persuasive.
Even if motivation was required, the Examiner has provided a
motivation to combine the references. Ans. 4. The Examiner stated, on
page 4 of the Answer, that the combination of Hamilton’s switches with
Emslie would “allow[s] surge current to be available immediately.”
Appellant argues that the immediate availability of the surge current is not a
result of Hamilton’s two switches, but rather the result of Hamilton’s current
limit circuit. App. Br. 6-7; Reply Br. 1. In response, the Examiner has
pointed out that the current limit circuit uses the switches to make the
current available or unavailable when the switches are turned on or off,
respectively. Ans. 8-9. We agree with the Examiner.
The current flowing through Hamilton’s switches 30A and 30B when
the switches are turned on is sensed by the current limit circuit 24 and is
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compared to a dynamic current limit. FF 8. Since the dynamic current limit
is a function of the current flowing through the switches averaged over time,
the longer current flows through the switches, the lower the current limit
which allows the initial current demand to be at a maximum. FF 9.
Therefore, the switches are vital to creating the availability of surge current
and Appellant’s arguments are not found to be persuasive.
Lastly, Appellant argues that the references do not teach all of the
claim limitations of claim 1. App. Br. 8-10; Reply Br. 2-3. Claim 1 recites
“first switching circuit being operative to controllably switch a first current
through said primary winding in accordance with first transitions in said
composite signal…[and] second switching circuit being operative to
controllably switch a second current through said primary winding in
accordance with second transitions in said composite signal.” Appellant
argues that neither reference discloses the above cited portions of claim 1.
App. Br. 8; Reply Br. 2-3. The Examiner found that Hamilton teaches that
the first and second control signal transitions are used to switch the first and
second control currents through a primary winding using the switches 30A
and 30B. Ans. 12. We agree with the Examiner.
Emslie discloses a pulse width modulated signal that is applied to the
royer 2 in superposition, wherein the royer 2 acts as a DC to AC converter.
FF 1, 3. The signals are logically ANDed together to form a composite
signal. FF 3. Hamilton discloses switches 30A and 30B that operate “in a
push-pull pulse width modulated mode.” FF 6. The control pulses SWA
and SWB from the input controller 20 control the switches. FF 6. When
switch 30A is energized (i.e., control pulse SWA is received), power is
pushed into the first leg 40A of the transformer primary 40 from IN1,
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through the switch 30A, and to IN2. FF 7. This is the same as controllably
switching the first current through the primary winding in accordance with
the first control signal. When switch 30B is energized (i.e., control pulse
SWB is received), power is pulled into the second leg 40B of the
transformer primary 40 from IN1, through switch 30B, and to IN2. FF 7.
This is the same as controllably switching the second current through the
primary winding in accordance with the second control signal. Since
Hamilton discloses a system wherein the switches are operated in a pulse
width modulated mode, Emslie’s composite signal is equal to the first and
second control signal transitions. Therefore, Hamilton discloses the claim
limitations of claim 1 and Appellant’s arguments are not found to be
persuasive.
As such, for the reasons stated above, we sustain the Examiner’s
rejection of claim 1 and claims 4 and 11, which are grouped with claim 1.
Claims 13, 16, and 20
Appellant’s arguments have not persuaded us of error in the
Examiner’s rejection of claims 13, 16, and 20. Independent claim 13
contains similar limitations discussed supra with respect to claim 1 and
claims 16 and 20 are dependent upon claim 13. Appellant’s arguments
present the same issues discussed with respect to claim 1. App. Br. 11-12;
Reply Br. 1-3. Therefore, we sustain the Examiner’s rejection of claims 13,
16, and 20 for the reasons discussed supra with respect to claim 1.

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Rejection of claim 5 under 35 U.S.C. § 103(a) as being unpatentable over
Emslie in view of Hamilton and Turner

Appellant’s arguments have not persuaded us of error in the
Examiner’s rejection of claim 5. Claim 5 ultimately depends upon claim 1
and as such includes the same limitations discussed supra with respect to
claim 1. Appellant’s arguments present the same issues discussed with
respect to claim 1. App. Br. 6-10; Reply Br. 1-3. Therefore, we sustain the
Examiner’s rejection of claim 5 for the reasons discussed supra with respect
to claim 1.

CONCLUSIONS OF LAW
Appellant has not shown that the Examiner erred in combining Emslie
with Hamilton.
Appellant has not shown that the Examiner erred in finding that
Emslie in view of Hamilton teach first and second switching circuits that
controllably switch first and second currents, respectively, through the
primary winding in accordance with first and second transitions in the
composite signal.

SUMMARY
The Examiner’s rejection of claims 1, 4-5, 11, 13, 16, and 20 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).

AFFIRMED
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ELD

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