Ex Parte Lim

Patent Trial and Appeal Board

Sep 9, 2013

11111724 (P.T.A.B. Sep. 9, 2013)

UNITED STATES PATENT AND TRADEMARK OFFICE
____________

BEFORE THE PATENT TRIAL AND APPEAL BOARD
____________

Ex parte MOO JONG LIM
____________

Appeal 2011-004016
Application 11/111,724
Technology Center 2600
____________

Before CARL W. WHITEHEAD, JR., ERIC S. FRAHM, and
ANDREW J. DILLON, Administrative Patent Judges.

DILLON, Administrative Patent Judge.

DECISION ON APPEAL
Appellant appeals under 35 U.S.C. § 134(a) from the Examiner’s
rejection of claims 1, 9, and 15. We have jurisdiction under 35 U.S.C.
§ 6(b).
We affirm.

App
App

(LCD
[004
Figu
138
feedb
eal 2011-0
lication 11
The inve
) backlig
7]-[0050].
res 7 and 1
Figure 7
Figure 1
Appellan
control (
12) for d
As show
generates a
ack FB.
04016
/111,724
ST
ntion imp
ht by modu
An embo
2, reprodu
:
2:
t’s Figur
Figure 7)
riving an
n in Appe
switching
Spec., ¶¶ [
ATEMEN
roves feed
lating the
diment of
ced below
es 7 and
and result
LCD back
llant’s Fig
control s
0011]-[00
2
T OF TH
back contr
backlight
the invent
.
12, abov
ing AC v
light.
ure 7, a Pu
ignal SCS
13] and [0
E CASE
ol of a Liq
’s control
ion is show
e, illustra
oltage wav
lse Width
based on t
015]. The
uid Crysta
signal. Sp
n by App
te a feed
eform (F
Modulato
he backlig
switching
l Display
ec., ¶¶
ellant’s

back
igure
r (PWM)
ht’s
control
Appeal 2011-004016
Application 11/111,724

3
signal SCS is then modulated based on two input signals Mduty, Moffset,
thus yielding a modulated switching control signal MSCS that causes an
inverter 132 and transformer 134 to output a two-peaks-per-cycle AC
voltage for driving a backlight 121. Spec., ¶¶ [0046], [0050], and [0064].
Only independent claims 1, 9, and 15 are pending. Claim 1 is
illustrative:
1. An apparatus for driving a lamp of a liquid crystal
display device, comprising:
a control signal generator generating a switching control
signal;
a waveform modulator modulating at least an amplitude
of the switching control signal to generate a modulated
switching control signal;
an AC waveform generator converting a supply voltage
based on the modulated switching control signal to generate an
AC waveform for driving the lamp, the AC waveform including
at least two different peak-to-peak amplitudes within a time
period,
a transformer increasing voltage levels of the AC
waveform and supplying the increased AC waveform to the
lamp, the increased AC waveform including at least two
different peak-to-peak amplitudes within the time period, and
a feedback circuit detecting a tube current of the lamp
and generating a feedback signal corresponding to the tube
current, wherein the control signal generator generates the
switching control signal based on the feedback signal,
wherein the switching control signal includes an on-time
portion and an off-time portion within each time period,
wherein the waveform modulator includes:
Appeal 2011-004016
Application 11/111,724

4
a duty modulator to change the on-time portion of
the switching control signal in response to a first
modulation signal;
an amplitude modulator to change the off-time
portion of the switching control signal in response to a
second modulation signal, wherein the off-time portion
includes a waveform amplitude lower than an amplitude
of the on-time portion and greater than zero,
wherein the duty modulator fixes the on-time portion of
the AC waveform of high voltage supplied to the lamp in
accordance with the first modulation signal, and at the same
time, the amplitude modulator controls the amplitude of the off-
time portion of the AC waveform of high voltage supplied to
the lamp in accordance with the second modulation signal,
wherein within each time period, the increased AC
waveform includes a first AC waveform pattern having a first
peak-to-peak amplitude during a first sub-period and a second
AC waveform pattern having a second peak-to-peak amplitude
during the second sub-period, the second peak-to-peak
amplitude being less than the first peak-to-peak amplitude,
wherein the switching control signal includes first and
second sub-periods within each time period, and the waveform
modulator modulates lengths of the first and second sub-periods
of the switching control signal to generate the modulated
switching control signals,
wherein the on-time portion modulated by the duty
modulator is set in a range 30% to 100% within each time
period.
The Examiner relies on the following references as evidence of
unpatentability:
Hirakata US 2002/0067332 A1 June 6, 2002
Appellant’s Figure 2 (“background art”)
App
App

as un
Hira
Br.,
repro
whic
seco
art so

1 Thr
2010
Sept
(“Re
eal 2011-0
lication 11
The Exa
patentable
kata. Ans
Appellan
p. 15. Cla
duced bel
Appellan
feedback
To deriv
h respectiv
nd modula
as to yiel

oughout t
and filed
ember 8, 2
ply Br.”).
04016
/111,724
miner reje
over App
., pp. 4-22
t presents
im 1 stand
ow, in vie
t’s Figur
control fo
e the claim
ely modu
tion signa
d the brigh

his opinion
July 14, 2
010 (“Ans
REJ
cted claim
ellant’s Fi
.1
AN
all claims
s rejected
w of Hirak
e 2, abo
r driving
ed invent
late a swit
ls, the Exa
tness wav

, we refer
010 (“App
.”), and R
5
ECTIONS
s 1, 9, and
gure 2 bac
ALYSIS
as standin
as obvious
ata. Ans.
ve, illustr
an LCD ba
ion’s duty
ching cont
miner mod
eforms of
to the App
. Br.”), Ex
eply Brief

15 under
kground a
g or fallin
over App
, pp. 4-10.
ates a b
cklight.
and ampli
rol signal
ifies App
Hirakata’
eal Brief
aminer’s A
filed Nov
35 U.S.C.
rt in view
g with cla
ellant’s Fi

ackground
tude modu
based on f
ellant’s ba
s Figures 2
filed Augu
nswer m
ember 5, 2
§ 103(a)
of
im 1. App
gure 2,

art
lators,
irst and
ckground
8A-D and
st 12,
ailed
010
.

Appeal 2011-004016
Application 11/111,724

6
29. Ans., pp. 25-29. In doing so, the Examiner finds that Hirakata’s system
must employ some form of inputs that modulate the backlight control signal
106 (see Hirakata’s Figure 7) so as to set the desired amplitudes and duty
cycles of the brightness waveforms. Id. In turn, the Examiner finds that the
modified background art would also employ such inputs and thus modulate a
switching control signal based on first and second modulation signals, as
claimed. Id. The Examiner states in part:
[A]s shown in Figures 28A-28D and Figure 29, Hirakata
provides for the control of both the amplitude and the duty
cycle of the pulsed control waveform. Thus, it is both inherent
and necessary for Hirakata to implement both an amplitude
control function and a duty cycle control function . . . in order
to control the amplitude and the duty cycle of the pulsed control
waveforms as shown in Figures 28A-28D and Figure 29. . . .
[T]he applicant has not claimed any features relating to the
“first modulation signal” and the “second modulation signal”
that would distinguish these claimed signals from the signals
that must necessarily be present in the Waveform Modulator of
Hirakata to generate the amplitude and duty cycle modulated
waveforms. In fact, the claims leave open to interpretation a
determination of the nature of the “signals” that produce the
“response” claimed by the applicant. In this regard, the signals
used by Hirakata to generate amplitude and duty cycle
modulation, whatever the nature of these signals, can clearly be
interpreted as relating to the “modulation signals” recited in the
claims.
Id. at pp. 27-28 (emphasis omitted).
Appellant contends there is no inherent need for Hirakata’s system to
input signals that modulate a backlight control signal so as to set the desired
amplitudes and duty cycles of the brightness waveforms. Reply Br., p. 6.
Appellant presents extrinsic evidence in support of this position, stating:
Appeal 2011-004016
Application 11/111,724

7
[A] review of the attached Maxim Max 1895/Max1995 CCFL
Backlight Controller datasheet (Maxim, High-Efficiency, Wide
Brightness Range, CCFL Backlight Controllers,
MAX1895/MAX1995, 19-2157 (Rev. 1, 2002)), (“the
Datasheet”) reveals that the Hirakata patent cannot inherently
include “a duty modulator to change the on-time portion of the
switching control signal in response to a first modulation
signal” and “an amplitude modulator to change the off-time
portion of the switching control signal in response to a second
modulation signal.” The Max1895 may control the brightness
of the backlight using: 1) linearly controlling the lamp current,
i.e., amplitude; 2) digital pulse-width modulating the lamp
current; or 3) with both methods simultaneously. See
Datasheet, p. 9. In one example, with regard to the Max1895, a
digital brightness control interface in accordance with SMBus
protocol is documented as a possible method to input brightness
commands into a backlight controller. Id., pp. 23-25. The
Datasheet describes the Max1895 using a two-wire digital
interface with a 5-bit brightness register corresponding with a
5-bit brightness code used in the dimming control. Id.
Thus, the Datasheet teaches at least one alternative to
change the on-time and off-time portions of the switching
control signal modulated by a waveform modulator other than
in response to a first and second modulation signals.
Reply Br., p. 7.
Appellant’s argument is not persuasive. The Examiner found that
Hirakata’s control signal 106 must be modulated by at least two signals –
“whatever the nature” (Ans., p. 28) – so as to set the desired amplitudes and
duty cycles of the brightness waveforms. Ans., pp. 26-29. Appellant
responds with argument and evidence that respective signal carriers,
waveforms, etc., would not have been the only means of setting the desired
amplitudes and duty cycles of Hirakata’s brightness waveforms. Reply Br.,
p. 7 (above block quote). Contrary to Appellant’s response, however, claim
Appeal 2011-004016
Application 11/111,724

8
1 does not recite the first and second modulation signals (which modulate
the claimed switching circuit signal) as constituting distinct signal carriers,
waveforms, etc.
Rather, claim 1 merely recites that: (i) based on the first modulation
signal, the duty modulator changes an on-time portion of the switching
control signal and fixes an on-time portion of an AC waveform for driving a
lamp; and (ii) based on the second modulation signal, the amplitude
modulator changes an off-time portion of the switching control signal and
controls the amplitude of an off-time portion of the AC waveform for
driving the lamp. Thus, only particular effects of the first and second
modulation signals are required by claim 1, whereas their forms and formats
are unspecified and accordingly irrelevant. Cf., In re Nuijten, 500 F.3d
1346, 1353 (Fed. Cir. 2007) (“So long as some object or transmission carries
the information specified by Nuijten’s claim, it falls within that claim’s
scope regardless of its physical form. In summary, some physical form for
the signal is required, but any form will do, so long as a recipient can
understand the message – the nature of the signal’s physical carrier is totally
irrelevant to the claims at issue.”).
In short, the Examiner proposed a reasonable modification that attains
the claimed effects of the first and second modulation signals. Nothing more
is required by these signals of unspecified form. Accordingly, the
obviousness rejection of claims 1, 9, and 15 over Appellant’s background art
and Hirakata is affirmed.
Appeal 2011-004016
Application 11/111,724

9
ORDER
The Examiner’s decision rejecting claims 1, 9, and 15 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)(iv).
AFFIRMED

llw