Ex parte Henzen

Board of Patent Appeals and Interferences

Apr 23, 2001

08762687 (B.P.A.I. Apr. 23, 2001)

1
The opinion in support of the decision being entered today was
not written for publication and is not binding precedent of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 ALEXANDER V. HENZEN
_____________
Appeal No. 1999-1559
Application No. 08/762,687
______________
ON BRIEF
_______________
Before FLEMING, RUGGIERO, and BLANKENSHIP, Administrative
Patent Judges.
FLEMING, Administrative Patent Judge.
DECISION ON APPEAL
This is a decision on appeal from the final rejection of
claims 1 through 6, all of the claims pending in the present
application.
The invention relates to a liquid crystal display device
Appeal No. 1999-1559
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2
comprising twisted nematic liquid crystal material having a
positive dielectric anisotropy between two substrates. On
page 1 of the specification, Appellant discloses that liquid
crystal display devices using twisted nematic liquid crystal
material have problems due to threshold voltage and saturation
voaltage are dependent on ambient temperature. On page 2 of
the specification, Appellant disclose that the invention is
based on the recognition that this problem is solved by
controlling the frequency at which the pixels are driven based
upon the variation of the ambient temperature. On page 3 of
the specification, Appellant discloses that Figure 1 is a
diagrammatic cross-section of a part of a liquid crystal
display comprising a crystal 1 having a twisted nematic liquid
crystal material 2 which is present between two supporting
substrates 3 and 4. Appellant also discloses that the cell
includes a temperature sensor 9 which is connected to a drive
section 10. Figure 1 shows that drive section 10 includes
element 17. On page 5 of the specification, Appellant
discloses that Figure 6 shows diagrammatically the structure
of element 17 of the drive section 10. In particularly,
Appellant discloses that element 17 comprises a frequency
Appeal No. 1999-1559
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selection circuit 20 which varies the frequency based upon the
measured temperature.
The independent claim 1 is reproduced as follows:
1. A liquid crystal display device comprising a first sub
strate which is provided with electrodes, and a
second substrate which is parallel to the first
substrate and is provided with electrodes, and a
twisted nematic liquid crystal material having a
positive dielectric anisotropy between the two
substrates, while, viewed perpendicularly to the
substrates, overlapping parts of the electrodes
define pixels, the display device being further
provided with drive means for presenting voltages to
the electrodes, characterized in that the drive
means are provided with means for controlling the
frequency at which pixels are driven, dependent on
the temperature of the display device.
The Examiner relies on the following references:
Fukai et al. (Fukai) 4,045,791 Aug. 30,
1977
Tsuboyama et al. (Tsuboyama) 4,902,107 Feb. 20,
1990
Claims 1 through 6 stand rejected under 35 U.S.C. § 103
as being unpatentable over Tsuboyama in view of Appellant's
admitted prior art.
Claims 1 through 6 stand rejected under 35 U.S.C. § 103
as being unpatentable over Fukai in view of Appellant's
admitted prior art.
Appeal No. 1999-1559
Application No. 08/762,687
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Rather than reiterate the arguments of the Appellant and
the Examiner, reference is made to the brief and answer for
the respective details thereof.
OPINION
We will not sustain the rejection of claims 1 through 6
under 35 U.S.C. § 103.
The Examiner has failed to set forth a prima facie case.
It is the burden of the Examiner to establish why one having
ordinary skill in the art would have been led to the claimed
invention by the express teachings or suggestions found in the
prior art, or by implications contained in such teachings or
suggestions. In re Sernaker, 702 F.2d 989, 995, 217 USPQ 1, 6
(Fed. Cir. 1983). "Additionally, when determining
obviousness, the claimed invention should be considered as a
whole; there is no legally recognizable 'heart' of the
invention." Para-Ordnance Mfg. v. SGS Importers Int'l Inc.,
73 F.3d 1085, 1087, 37 USPQ2d 1237, 1239 (Fed. Cir. 1995),
citing W. L. Gore & Assocs., Inc., v. Garlock, Inc., 721 F.2d
1540, 1548, 220 USPQ 303, 309 (Fed. Cir. 1983).
On pages 6 through 8 of the brief, Appellant argues that
Appeal No. 1999-1559
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there is no teaching or even suggestion in Tsuboyama that the
Tsuboyama ferroelectric liquid crystal material may be
replaced by a twisted nematic liquid crystal material having a
positive dielectric anisotropy as claimed by Appellant. On
pages 8 and 9 of the brief, Appellant also argues that there
is no teaching or suggestion in the Fukai patent that the
liquid crystal material should be a twisted nematic liquid
crystal material.
The Federal Circuit states that "[t]he mere fact that the
prior art may be modified in the manner suggested by the
Examiner does not make the modification obvious unless the
prior art suggested the desirability of the modification." In
re Fritch, 972 F.2d 1260, 1266 n.14, 23 USPQ2d 1780, 1783-84
n.14 (Fed. Cir. 1992), citing In re Gordon, 733 F.2d 900, 902,
221 USPQ 1125, 1127 (Fed. Cir. 1984). It is further
established that "[s]uch a suggestion may come from the nature
of the problem to be solved, leading inventors to look to
references relating to possible solutions to that problem."
Pro-Mold & Tool Co. v. Great Lakes Plastics, Inc., 75 F.3d
1568, 1573, 37 USPQ2d 1626, 1630 (Fed. Cir. 1996), citing In
Appeal No. 1999-1559
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6
re Rinehart, 531 F.2d 1048, 1054, 189 USPQ 143, 149 (CCPA
1976)(considering the problem to be solved in a determination
of obviousness). The Federal Circuit reasons in Para-Ordnance
Mfg. Inc. v. SGS Importers Int'l Inc., 73 F.3d 1085, 1088-89,
37 USPQ2d 1237, 1239-40 (Fed. Cir. 1995), that for the
determination of obviousness, the court must answer whether
one of ordinary skill in the art who sets out to solve the
problem and who had before him in his workshop the prior art,
would have been reasonably expected to use the solution that
is claimed by the Appellant. However, "[o]bviousness may not
be established using hindsight or in view of the teachings or
suggestions of the invention." Para-Ordnance Mfg. v. SGS
Importers Int'l, 73 F.3d at 1087, 37 USPQ2d at 1239, citing W.
L. Gore & Assocs., Inc. v. Garlock, Inc., 721 F.2d at 1551,
1553, 220 USPQ at 311, 312-13. In addition, our reviewing
court requires the PTO to make specific findings on a
suggestion to combine prior art references. In re Dembiczak,
175 F.3d 994, 1000-01, 50 USPQ2d 1614, 1617-19 (Fed. Cir.
1999).
Upon our review of Tsuboyama, we agree with Appellant
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that Tsuboyama fails to teach or even suggest the proposed
modification by the Examiner. In particular, we note that in
column 3, lines 22 through 24, Tsuboyama is concerned with
unrelated problems of the need for spacing between the
substrates and the tilt angle. Tsuboyama is not concerned
with the problem of providing operational bistability of the
pixel based upon variations of nematic temperature.
In regard to Fukai, we find no suggestion of varying the
frequency of the voltage to overcome the problems of the
liquid crystal material employed. While Fukai shows a liquid
crystal display device having a nematic crystal material,
there is no teaching or suggestion that Fukai contemplates the
problems of using a liquid crystal material that is a twisted
nematic liquid crystal material having a positive dielectric
anisotropy as Appellant has claimed.
We note that the only relevant art concerning the problem
of a twisted nematic liquid crystal material having a positive
dielectric anisotropy is the prior art admitted by the
Appellant found on page 1 of the specification. The admitted
prior art recognizes the problem that this type of material
has problems at varying ambient temperature because of the
Appeal No. 1999-1559
Application No. 08/762,687
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characteristics of the twisted nematic liquid crystal material
having a negative dielectric anisotropy. However, the
admitted prior art solves the problem not by varying the
frequency of the drive circuit but instead varies the drive
voltage. We fail to find that the Examiner has provided any
evidence to suggest that one of ordinary skill in the art who
sets out to solve the problem of compensating for variations
of the characteristics of a liquid crystal made from a
ferroelectric crystal material having negative dielectric
anisotropy due to the ambient temperature would have been
reasonably expected to use the solution proposed by either
Tsuboyama or Fukai which are dealing with completely different
materials having completely different characteristics.

In view of the foregoing, we have not sustained the
rejections of claims 1 through 6 under 35 U.S.C. § 103.
Accordingly, the Examiner's decision is reversed.
REVERSED
Appeal No. 1999-1559
Application No. 08/762,687
9
MICHAEL R. FLEMING )
Administrative Patent Judge )
)
) BOARD OF PATENT
)
JOSEPH F. RUGGIERO ) APPEALS AND
Administrative Patent Judge )
) INTERFERENCES
)
)
HOWARD D. BLANKENSHIP )
Administrative Patent Judge )
MRF:lbg
CORPORATE PATENT COUNSEL
US PHILIPS CORPORATION
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