Ex parte MANO et al.

Board of Patent Appeals and Interferences

Dec 5, 2000

08320729 (B.P.A.I. Dec. 5, 2000)

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not written for publication and is not binding precedent of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. 35
UNITED STATES PATENT AND TRADEMARK OFFICE
__________
BEFORE THE BOARD OF PATENT APPEALS
AND INTERFERENCES
__________
Ex parte TOSHIHIKO MANO, TOSHIMOTO KODAIRA and HIROYUKI OSHIMA
__________
Appeal No. 1998-1993
Application 08/320,729
___________
HEARD: November 15, 2000
___________
Before THOMAS, HAIRSTON, and JERRY SMITH, Administrative
Patent Judges.
JERRY SMITH, Administrative Patent Judge.
DECISION ON APPEAL
This is a decision on the appeal under 35 U.S.C. § 134
from the examiner’s rejection of claims 44-51 and 53, which
constitute all the claims remaining in the application.
The disclosed invention pertains to a liquid crystal
Appeal No. 1998-1993
Application 08/320,729
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display device wherein data signals are supplied to the liquid
crystal cells through a plurality of field effect transistors
arranged in a plurality of picture elements. The invention is
primarily directed to details of the field effect transistors.
Representative claim 44 is reproduced as follows:
44. A liquid crystal device wherein data signals are
supplied to liquid crystal cells through a plurality of field
effect transistors arranged in a plurality of picture
elements, each of said field effect transistors comprising:
a channel region comprising a thin film of silicon;
a gate insulating film in contact with the channel
region; and
a gate electrode in contact with the gate insulating film
and opposing the channel region, wherein a leakage current of
the field effect transistor in the OFF state is dependent on
the thickness of the channel region, and the channel region
has a thickness less than 2500A so that when the field effect
transistor is in the OFF state, the leakage current flowing
through the field effect transistor is less than 1/10 of the
leakage current flowing through a corresponding liquid crystal
cell based on a resistance of the liquid crystal cells and an
area of the picture elements.
The examiner relies on the following references:
Asars et al. (Asars) 4,112,333 Sep. 05, 1978
Morozumi 4,582,395 Apr. 15, 1986
Mano et al. (Mano) 5,124,768 June 23, 1992
Holmberg et al. (Holmberg) 2,067,353 July 22, 1981
(UK Patent Application)
Togashi 2,070,857 Sep. 09, 1981
Appeal No. 1998-1993
Application 08/320,729
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(UK Patent Application)
The following rejections are on appeal before us:
1. Claims 44-51 and 53 stand rejected as unpatentable
under the judicially established doctrine of obviousness-type
double patenting over the claims of Mano.
2. Claim 53 stands rejected as unpatentable under the
judicially established doctrine of obviousness-type double
patenting over the claims of Mano considered further with
Holmberg.
3. Claims 44-49 and 51 stand rejected under 35 U.S.C.
§ 103 as being unpatentable over the teachings of Morozumi
considered with Togashi and Asars.
4. Claims 50 and 53 stand rejected under 35 U.S.C.
§ 103 as being unpatentable over the teachings of Morozumi
considered with Togashi and Asars, and considered further with
Holmberg.
Rather than repeat the arguments of appellants or the
Appeal No. 1998-1993
Application 08/320,729
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examiner, we make reference to the briefs and the answer for
the respective details thereof.
OPINION
We have carefully considered the subject matter on
appeal, the rejections advanced by the examiner and the
evidence of obviousness relied upon by the examiner as support
for the rejections. We have, likewise, reviewed and taken
into consideration, in reaching our decision, the appellants’
arguments set forth in the briefs along with the examiner’s
rationale in support of the rejections and arguments in
rebuttal set forth in the examiner’s answer.
It is our view, after consideration of the record before
us, that the examiner has failed to establish a case of
obviousness-type double patenting of the appealed claims. We
are also of the view that the evidence relied upon and the
level of skill in the particular art would not have suggested
to one of ordinary skill in the art the obviousness of the
invention as set forth in claims 44-51 and 53. Accordingly,
we reverse.
We consider first the rejection of claims 44-51 and 53
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Application 08/320,729
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based on the grounds of double patenting. Although the
examiner has nominally designated this rejection as being
based on the judicially created doctrine of obviousness-type
double patenting, the examiner has made no obviousness
determinations of the appealed claims with respect to the
claims of Mano. Instead, the examiner has asserted that
obviousness determinations did not have to be considered
because, in the examiner’s view, these appealed claims fall
within the ambit of In re Schneller, 397 F.2d 350, 158 USPQ
210 (CCPA 1968). Based on the examiner’s interpretation of
Schneller, the examiner finds that appealed claims 44-51 and
53 of this application cover subject matter “already
adequately claimed and covered in [Mano]” [answer, page 6].
Appellants do not discuss the application of Schneller to
the facts of this case. Instead, appellants simply argue that
the appealed claims are not unpatentable under the doctrine of
obviousness-type double patenting because neither claims 1-17
of Mano nor the teachings of Morozumi, Asars, Togashi and/or
Holmberg disclose or suggest the subject matter specifically
recited in independent claim 44 [brief, page 11].
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Application 08/320,729
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The rejection of claims on obviousness-type double
patenting based on the decision in Schneller has recently
found favor with patent examiners. The Board of Patent
Appeals and Interferences has recently published a decision
which discusses in detail the “cover” test of Schneller and
its applicability to obviousness-type double patenting
rejections. See ex parte Davis, 56 USPQ2d 1434 (BPAI 2000).
We adopt the reasoning of the panel in Davis in deciding this
appeal. To put it briefly, the “cover” test of Schneller
should be interpreted as a test to determine whether the
claims of an application and the claims of a patent are
patentably distinct. Thus, in considering the obviousness-
type double patenting rejection before us on this appeal, the
appropriate question is whether claims 44-51 and 53 of this
application are patentably distinct from the claims of Mano.
Claims 44-51 and 53 recite limitations which do not
appear in the claims of the Mano patent. As noted above, the
examiner has made no determinations regarding the obviousness
of these limitations which do not appear in the claims of the
patent. In making a prima facie case of obviousness-type
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Application 08/320,729
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double patenting, an examiner has the same burden as when an
obviousness rejection under 35 U.S.C. § 103 is made. Thus, at
a minimum the examiner is required to identify the differences
between the applications claims and the claims of the patent
and to provide a reason why these differences would have
resulted from an obvious modification to the claims of the
patent. The examiner’s failure to address the differences
between the appealed claims and the claims of the Mano patent,
and the examiner’s failure to address the obviousness of these
differences result in a failure by the examiner to establish a
prima facie case of unpatentability. Therefore, we do not
sustain any of the examiner’s rejections of claims 44-51 and
53 based on obviousness-type double patenting.
We now consider the rejection of the claims under 35
U.S.C. § 103. In rejecting claims under 35 U.S.C. § 103, it
is incumbent upon the examiner to establish a factual basis to
support the legal conclusion of obviousness. See In re Fine,
837 F.2d 1071, 1073, 5 USPQ2d 1596, 1598 (Fed. Cir. 1988). In
Appeal No. 1998-1993
Application 08/320,729
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so doing, the examiner is expected to make the factual
determinations set forth in Graham v. John Deere Co., 383 U.S.
1, 17, 148 USPQ 459, 467 (1966), and to provide a reason why
one having ordinary skill in the pertinent art would have been
led to modify the prior art or to combine prior art references
to arrive at the claimed invention. Such reason must stem
from some teaching, suggestion or implication in the prior art
as a whole or knowledge generally available to one having
ordinary skill in the art. Uniroyal, Inc. v. Rudkin-Wiley
Corp., 837 F.2d 1044, 1051, 5 USPQ2d 1434, 1438 (Fed. Cir.),
cert. denied, 488 U.S. 825 (1988); Ashland Oil, Inc. v. Delta
Resins & Refractories, Inc., 776 F.2d 281, 293, 227 USPQ 657,
664 (Fed. Cir. 1985), cert. denied, 475 U.S. 1017 (1986); ACS
Hosp. Sys., Inc. v. Montefiore Hosp., 732 F.2d 1572, 1577, 221
USPQ 929, 933 (Fed. Cir. 1984). These showings by the
examiner are an essential part of complying with the burden of
presenting a prima facie case of obviousness.
Note In re Oetiker, 977 F.2d 1443, 1445, 24 USPQ2d 1443, 1444
(Fed. Cir. 1992). If that burden is met, the burden then
shifts to the applicant to overcome the prima facie case with
Appeal No. 1998-1993
Application 08/320,729
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argument and/or evidence. Obviousness is then determined on
the basis of the evidence as a whole and the relative
persuasiveness of the arguments. See Id.; In re Hedges, 783
F.2d 1038, 1039, 228 USPQ 685, 686 (Fed. Cir. 1986); In re
Piasecki, 745 F.2d 1468, 1472, 223 USPQ 785, 788 (Fed. Cir.
1984); and In re Rinehart, 531 F.2d 1048, 1052, 189 USPQ 143,
147 (CCPA 1976). Only those arguments actually made by
appellants have been considered in this decision. Arguments
which appellants could have made but chose not to make in the
brief have not been considered [see 37 CFR
§ 1.192(a)].
We consider first the rejection of claims 44-49 and 51
based on the teachings of Morozumi, Togashi and Asars. These
claims stand or fall together as a single group [brief, page
3]. With respect to representative, independent claim 44, the
examiner points to Morozumi as teaching a transistor of the
type claimed in which it is desired to minimize leakage
current. Specifically, Figure 10 of Morozumi teaches the
relationship between transistor leakage current and the
thickness of the channel region. The lowest leakage current
Appeal No. 1998-1993
Application 08/320,729
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shown in Morozumi’s Figure 10 is about 0.05x10 amperes-9
corresponding to a channel thickness of about 1250 D.
Morozumi discloses that thin film transistors having leakage
currents of 100 picoamperes (0.1x10 amperes) or less were-9
possible [column 11, lines 46-48]. Thus, the examiner found
that Morozumi suggested low leakage liquid crystal devices in
which the transistors had a channel thickness of about 1250 D
and a leakage current of about 5x10 amperes. The examiner-11
cites Asars as teaching a low leakage liquid crystal device.
Asars discloses that such a device has a leakage resistance
equal to or greater than 10 ohms [column 5, lines 12-13]. 10
Based on the teachings of Morozumi and Asars, the examiner
finds that the low leakage liquid crystal device of Morozumi
should have a leakage resistance of 10 ohms or more as taught10
by Asars. The examiner notes that the low leakage liquid
crystal devices of Morozumi and Asars disclose nothing about
the size of such devices. The examiner notes that in making
the low leakage liquid crystal device of Morozumi and Asars,
the artisan would begin by considering liquid crystal cells
which had a size that was typical at the time of Morozumi and
Appeal No. 1998-1993
Application 08/320,729
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Asars. The examiner cites Togashi which teaches a typical
liquid crystal display panel in which each cell is a square of
about 0.04 square mm. Thus, the examiner finds that in making
a low leakage liquid crystal device, the artisan would have
used channel thicknesses, leakage currents and leakage
resistances as taught by Morozumi and Asars with cells
designed of a typical size as taught by Togashi. The examiner
concludes that a low leakage liquid crystal device designed
with the teachings of Morozumi, Asars and Togashi would
inherently have the 1/10 leakage current property recited in
claim 44 [answer, pages 7-9].
Appellants argue that the examiner is improperly picking
and choosing leakage resistance and cell size without proper
motivation. They assert that none of the references discloses
or suggests the advantage of using particular values of
resistance and cell size. Thus, appellants argue that the
examiner has used improper hindsight gleaned from appellants’
own specification in combining the teachings of Morozumi,
Asars and Togashi. Appellants also assert that the fact that
the combined teachings of the applied references may
Appeal No. 1998-1993
Application 08/320,729
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inherently perform like the claimed invention is not a
substitute for a teaching or suggestion supporting an
obviousness rejection [brief, pages 7-10; reply brief, pages
1-3].
The examiner’s combination of Morozumi, Asars and Togashi
is fundamentally based on the examiner’s view that these three
references simply represent three conventional teachings of a
low leakage current thin-film transistor. That is, the
examiner asserts that there is nothing remarkable about his
selection of the three applied references because they are
evidence of what was conventional in this art. We would agree
with the examiner that a legitimate case for obviousness could
be made in theory if the three applied references related to
conventional features of the same or similar transistors.
However, we are unable to draw that conclusion.
The artisan would have appreciated that the operating
characteristics of a transistor are a function of many
Appeal No. 1998-1993
Application 08/320,729
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variables such as operating voltages, device sizes, and the
materials used in the manufacture of the devices. It is our
view that in order for several different references to be
cited as conventional features of a transistor, the
transistors of the several references should all have similar
operating ranges, device sizes and device materials. In other
words, a conventional feature of a transistor operating under
one condition would not necessarily be a conventional feature
of a different transistor operating under different
conditions.
Of particular concern to us is the difference in the
range of voltages in which Morozumi, Asars and Togashi are
designed to operate and the differences in the semiconductor
channel materials. Morozumi describes a liquid crystal device
operating at about 10 volts [column 8, lines 26-43; column 11,
line 48]. Asars describes a liquid crystal device operating
at about 80 volts [column 5, lines 10-12]. Togashi describes
a liquid crystal device operating at about 40 volts [page 3,
line 113]. Thus, the first thing we note is that the liquid
crystal devices of Morozumi, Asars and Togashi are designed to
Appeal No. 1998-1993
Application 08/320,729
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operate at substantially different voltage levels.
Morozumi, like the claimed invention, has a channel
region comprised of a thin film of silicon [column 2, lines 1-
8]. The channel region in Asars is comprised of cadmium
selenide [column 3, lines 28-30]. Togashi discloses
transistors having a channel region comprised of a thin film
of cadmium selenide or an amorphous form of silicon.
Therefore, once again, the alleged conventional properties of
these devices relate to devices which are not all formed of
the same material.
When the differences between the liquid crystal devices
of Morozumi, Asars and Togashi are considered, we are
constrained to find that these three references are not
directed to the same liquid crystal device. Therefore, what
the examiner finds as conventional in one of these references
does not make it conventional when modified to meet the
different operating characteristics of the other liquid
crystal devices. Since the liquid crystal devices of these
three references are not the same, the “conventional”
teachings of one reference cannot simply be substituted into
Appeal No. 1998-1993
Application 08/320,729
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the device of one of the other references. Thus, one of
ordinary skill in the art would not have been motivated to
simply combine features of the different liquid crystal
devices of the applied prior art. Therefore, we agree with
appellants that the particular citation of Morozumi, Asars and
Togashi in the rejection before us results from an improper
attempt by the examiner to reconstruct the invention in
hindsight. Accordingly, we do not sustain the rejection of
claims 44-49 and 51 based on the collective teachings of
Morozumi, Asars and Togashi.
We now consider the rejection of claims 50 and 53 based
on the teachings of Morozumi, Togashi, Asars and Holmberg.
Morozumi, Togashi and Asars are applied as discussed above.
The examiner cites Holmberg as teaching another low leakage
liquid crystal device in which the channel thickness ranges
from 100 D to 5000 D with approximately 1000 D being one
example. The examiner notes that Holmberg also teaches a
ratio of drain current in the ON state to drain current in the
OFF state to be about 10 . The examiner finds that the liquid7
crystal device of Morozumi, Asars and Togashi with a channel
Appeal No. 1998-1993
Application 08/320,729
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thickness of about 1000 D would inherently have an ON/OFF
ratio similar to the ratio of 10 as disclosed by Holmberg7
[answer, page 9].
Appellants argue that Holmberg does not remedy the
deficiencies in the prior art as discussed above with respect
to claim 44. We agree. Since Holmberg does not overcome the
deficiencies in the basic combination of references discussed
above, we also do not sustain the rejection of claims 50 and
53 based on the applied prior art.
In summary, we have not sustained any of the examiner’s
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Application 08/320,729
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rejections of the appealed claims. Therefore, the decision of
the examiner rejecting claims 44-51 and 53 is reversed.
REVERSED
JAMES D. THOMAS )
Administrative Patent Judge )
)
)
) BOARD OF PATENT
KENNETH W. HAIRSTON )
Administrative Patent Judge ) APPEALS AND
)
) INTERFERENCES
)
JERRY SMITH )
Administrative Patent Judge )
Appeal No. 1998-1993
Application 08/320,729
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JS:pgg
James Oliff
Oliff & Berridge
P.O. Box 19928
Alexandria, Virginia 22320