Semiconductor Energy Laboratory Co., Ltd.

Patent Trials and Appeals Board

Sep 25, 2020

14867535 - (D) (P.T.A.B. Sep. 25, 2020)

UNITED STATES PATENT AND TRADEMARK OFFICE
UNITED STATES DEPARTMENT OF COMMERCE
United States Patent and Trademark Office
Address: COMMISSIONER FOR PATENTS
P.O. Box 1450
Alexandria, Virginia 22313-1450
www.uspto.gov
APPLICATION NO. FILING DATE FIRST NAMED INVENTOR ATTORNEY DOCKET NO. CONFIRMATION NO.
14/867,535 09/28/2015 Hideko INOUE 0553-1277 9805
24628 7590 09/25/2020
HUSCH BLACKWELL LLP
HUSCH BLACKWELL SANDERS LLP WELSH & KATZ
120 S RIVERSIDE PLAZA
22ND FLOOR
CHICAGO, IL 60606
EXAMINER
BOHATY, ANDREW K
ART UNIT PAPER NUMBER
1796
MAIL DATE DELIVERY MODE
09/25/2020 PAPER
Please find below and/or attached an Office communication concerning this application or proceeding.
The time period for reply, if any, is set in the attached communication.
PTOL-90A (Rev. 04/07)
UNITED STATES PATENT AND TRADEMARK OFFICE
BEFORE THE PATENT TRIAL AND APPEAL BOARD
Ex parte HIDEKO INOUE and TOMOYA YAMAGUCHI
Appeal 2020-000091
Application 14/867,535
Technology Center 1700
BEFORE BEVERLY A. FRANKLIN, JEFFREY B. ROBERTSON, and
JAMES C. HOUSEL, Administrative Patent Judges.
ROBERTSON, Administrative Patent Judge.
DECISION ON APPEAL1

1 This Decision includes citations to the following documents: Specification
filed September 28, 2015 (“Spec.”); Final Office Action mailed January 25,
2019 (“Final Act.”); Appeal Brief filed May 30, 2019 (“Appeal Br.”);
Examiner’s Answer mailed August 8, 2019 (“Ans.”); and Reply Brief filed
October 3, 2019 (“Reply Br.”).
Appeal 2020-000091
Application 14/867,535

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STATEMENT OF THE CASE
Pursuant to 35 U.S.C. § 134(a), Appellant2 appeals from the
Examiner’s decision to reject claims 1, 3–12, and 14–31.3 Appeal Br. 10.
We have jurisdiction under 35 U.S.C. § 6(b). We affirm.
CLAIMED SUBJECT MATTER
Appellant states the invention relates to an organometallic complex, as
well as a light-emitting element, a light-emitting device, electronic device,
and a lighting device including the organometallic complex. Spec. ¶ 1.
Claim 1 is representative of the claims on appeal and reproduced below
(Appeal Br., Claims Appendix 23):
1. An organometallic complex comprising:
a metal belonging to Group 9 or 10; and
a ligand,
wherein the ligand comprises a benzofuro[2,3-b]pyridine
skeleton or a benzothieno[2,3-b] pyridine skeleton, and a
pyrimidine ring,
wherein carbon at the 2-position of the benzofuro[2,3-
b]pyridine skeleton or the benzothieno[2,3-b]pyridine skeleton is
bonded to the metal,
wherein nitrogen at the 3-position of the pyrimidine ring
is bonded to the metal,
wherein carbon at the 3-position of the benzofuro[2,3-
b]pyridine skeleton or the benzothieno[2,3-b ]pyridine skeleton
is bonded to carbon at the 4-position of the pyrimidine ring,
wherein carbon at the 6-position of the pyrimidine ring is
bonded to an alkyl group or an aryl group, and

2 We use the word “Appellant” to refer to “applicant” as defined in 37
C.F.R. § 1.42(a). Appellant identifies Semiconductor Energy Laboratory
Co., Ltd., as the real party in interest. Appeal Br. 4.
3 Claims 2 and 13 have been canceled. See Appeal Br. 4.
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Application 14/867,535

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wherein the alkyl group is a substituted or unsubstituted
alkyl group having 4 to 10 carbon atoms.
Claims 12 and 23 are also independent and recite organometallic
complexes having structures recited therein. Id. at 25–26, 29.
REFERENCES
The prior art relied upon by the Examiner is:
Name Reference Date
Kwong et al.
hereinafter “Kwong”
US 2008/0261076 A1 October 23, 2008
Alleyne et al.
hereinafter “Alleyne”
US 2010/0090591 A1 April 15, 2010
Seo et al.
hereinafter “Seo”
US 2012/0274201 A1 November 1, 2012
Beers et al.
hereinafter “Beers”
US 2014/0131663 A1 May 15, 2014
REJECTIONS
1. The Examiner rejected claims 1, 3–12, 14–23, and 26–31 under 35
U.S.C. § 103 as unpatentable over Seo and Beers. Final Act. 5–6.
2. The Examiner rejected claims 24 and 25 under 35 U.S.C. § 103 as
unpatentable over Seo, Beers, Kwong, and Alleyne. Final Act. 6–
7.

OPINION
Rejection 1
Appellant does not present separate arguments with respect to the
claims subject to this rejection. See Appeal Br. 10–21. Thus, we select
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Application 14/867,535

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claim 1 as representative for disposition of this rejection. 37 C.F.R.
§ 41.37(c)(1)(iv).

The Examiner’s Rejection
In rejecting claim 1 as unpatentable over Seo and Beers, the Examiner
found Seo discloses electroluminescent devices comprising a
phosphorescent dopant that contains an iridium metal organometallic
complex including an aryl containing pyrimidine ligand such as a phenyl
pyrimidine ligand, but Seo does not disclose the phenyl (aryl) group may be
an azadibenzofuran or a dibenzothiophene. Final Act. 5. The Examiner
found Beers discloses ligands for iridium metal complexes used as
phosphorescent dopants including an azadibenzofuran group containing
ligand, where Beers discloses the azadibenzofuran group may be used to
slightly red shift the emission color of the dopant. Id. at 6, citing Beers
¶¶ 54, 55, 63, 80–82. The Examiner determined it would have been obvious
to have modified the compound dopants of Seo to change the phenyl group
in Seo to an azadibenzofuran or a dibenzothiophene group to red shift the
emission color of the dopant. Id.

Appellant’s contentions
Appellant contends Beers does not disclose a pyrimidine ring in the
compounds disclosed therein. Appeal Br. 13–14. As such, Appellant
contends there is an insufficient showing as to how the compounds disclosed
in Beers would be relevant to the claimed invention, which requires a
pyrimidine ring. Id. at 15. Appellant argues claim 1 requires the carbon at
the 2-position of the benzofuro[2,3-b]pyridine skeleton or the
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benzothieno[2,3-b]pyridine skeleton is bonded to the metal, whereas in
Beers, the bond to the metal is in a different position and not adjacent to the
nitrogen atom. Id. at 15–16. Appellant argues there has been no showing
that the different compounds will act the same as the claimed ligand and no
evidence that the claimed ligand will red shift. Id. at 16. Appellant contends
that the Specification discusses that when the atom adjacent to the carbon
atom bonded to the metal is an electron withdrawing nitrogen atom, which is
not present in the compounds shown in Table 1 of Beers, the emission
wavelength is short, which is contrary to red shifting that makes the
emission wavelength long. Id. at 17–21, citing Spec. ¶ 76. Appellant
contends the claimed invention achieves unexpected results, such as high
emission efficiency, high color purity, low power consumption, and high
reliability. Id., citing Spec. ¶¶ 76, 116–117.

Issue
Has Appellant demonstrated reversible error in the Examiner’s
position that an organometallic complex as recited in claim 1 would have
been obvious in view of Seo and Beers?

Discussion
We are not persuaded by Appellant’s arguments. A general formula
for the organometallic complexes falling within the complexes recited in
claim 1 is reproduced below (with annotations to show atom numbering
consistent with claim 1) from Appellant’s Specification (¶ 16; see also claim
12):
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General Formula G1 is an organometallic complex where L represents
a monoanionic ligand, R1 is a substituted or unsubstituted alkyl group having
4 to 10 carbon atoms or a substituted or unsubstituted aryl group having 6 to
13 carbon atoms; each of R2 to R5 independently represents hydrogen, a
substituted or unsubstituted alkyl group having 1 to 6 carbon atoms, or a
substituted or unsubstituted phenyl group; the organometallic complex is
monosubstituted, disubstituted, trisubstituted, tetrasubstituted, or
unsubstituted by the R5; X represents O or S; and M represents a metal
belonging to Group 9 or 10. When M represents a metal belonging to Group
9, m is 3 and n is 1, 2, or 3. When M represents a metal belonging to Group
10, m is 2 and n is 1 or 2. Spec. ¶¶ 16, 17.
As found by the Examiner, Seo discloses a phosphorescent
organometallic iridium (Group 9) complex including a pyrimidine ring. Seo
¶ 89. As an example, Seo discloses (acetylacetonato)bis( 6-tert-buty1-4-
phenylpyrimidinato )iridium(III) ([Ir(tBuppm)2(acac)]), the structure of
which (Structure 105) is reproduced below (Seo ¶ 279):
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The structure of Ir(tBuppm)(acac) reproduced above depicts an
organometallic complex wherein as recited in claim 1, the nitrogen at the 3-
position of the pyrimidine ring is bonded to the metal and wherein the
carbon at the 6-position of the pyrimidine ring includes an alkyl group (t-
butyl) that has four carbon atoms. However, in contrast to claim 1, rather
than the 4-position of the pyrimidine ring being bonded to a carbon at the 3-
position of a benzofuro[2,3-b]pyridine skeleton or a benzothieno[2,3-b
]pyridine skeleton, the 4-position of the pyrimidine ring is bonded to a
phenyl group, and a carbon of the phenyl group is bonded to the metal.
Beers discloses that in iridium pyridine complexes where it was
already known that substituting a dibenzofuran for a phenyl group (both
bonded to the metal via a carbon atom (see Beers ¶ 55, Table 1) resulted in a
slight red shift in emission, introducing an azadibenzofuran (benzofuro[2,3-
b]pyridine skeleton) substitution provides further red shifting. Beers ¶ 55.
In particular, and as identified by the Examiner (Final Act. 6; Ans. 9), Beers
discloses an example of such a ligand (LA107), reproduced below (Beers ¶ 63,
p. 38):
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The azadibenzofuran containing ligand disclosed in Beers and
reproduced above depicts a benzofuro[2,3-b]pyridine group as recited in
claim 1, wherein the carbon at the 3-position of the benzofuro[2,3-b]pyridine
group is bonded to a pyridine ring. In this regard, Appellant’s annotated
drawings of one ligand in Beers having a different structure than the ligand
in Beers relied on by the Examiner to indicate different attachment points
relative to the claimed ligand (Appeal Br. 16) are not persuasive, as
Appellant does not address the ligand in Beers relied upon by the Examiner.
Accordingly, we are not persuaded by Appellant’s argument that the
azadibenzofuran group of Beers, when substituted for the phenyl group in
Seo, would bond to the metal at a different attachment point, as the modified
ligand would have the same structure as recited in claim 1, and thus would
have been expected to bond to the metal at the same positions. In re
Fitzgerald, 619 F.2d 67, 70 (CCPA 1980) (“‘[T]he PTO can require an
applicant to prove that the prior art products do not necessarily or inherently
possess the characteristics of his claimed product. . . . Whether the rejection
is based on ‘inherency’ under 35 U.S.C. s [sic] 102, on ‘prima facie
obviousness’ under 35 U.S.C. s [sic] 103, jointly or alternatively, the burden
of proof is the same . . . (footnote omitted).’”) (quoting In re Best, 562 F.2d
1252, 1255 (CCPA 1977)).
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Thus, although Appellant emphasizes that Beers discloses a pyridine
ring rather than a pyrimidine ring as recited in claim 1, we are of the view
that one of ordinary skill in the art would have had a reasonable expectation
of success in substituting the phenyl group of Seo with the azadibenzofuran
(benzofuro[2,3-b]pyridine) group disclosed in Beers, because Beers
expressly discloses it is this substitution that provides further red shifting,
without attributing the effect of the benzofuro[2,3-b]pyridine group to the
pyridine ring. See Ans. 10. As stated by the Supreme Court in KSR, “any
need or problem known in the field of endeavor at the time of [the] invention
and addressed by the patent can provide a reason for combining the elements
in the manner claimed.” KSR Int’l Co. v. Teleflex Inc., 550 U.S. 398, 420
(2007). KSR instructs that “familiar items may have obvious uses beyond
their primary purposes.” Id. at 420–421. Accordingly, we are of the view
that the Examiner’s rationale is sufficiently supported and does not rely on
improper hindsight.
Moreover, Appellant’s contention that Seo’s disclosure shows a light
emitting element that has an emission wavelength peak at 548 nm and the
Specification shows a light emitting element with an emission peak at 519
nm, which represents a blue shift when moving from a phenyl group to
azadibenzofuran or dibenzothiophene as in claim 1 (Appeal Br. 18–20), is
not persuasive. In addition to not addressing the specific ligand of Beers
relied upon by the Examiner, as the Examiner points out, the alkyl groups on
the pyrimidine ligand are different. See Ans. 12. Thus, Appellant does not
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provide a direct comparison and therefore, such a comparison is insufficient
to support Appellant’s argument.4
In this regard, we are not persuaded by Appellant’s argument that
Beers discloses the ligands provide blue shifting rather than red shifting. As
the Examiner points out, Beers discloses such blue shifting occurs when
azadibenzofuran ligands are compared to dibenzofuran ligands. Beers ¶ 55;
Ans. 11. Indeed, Beers discloses that the azadibenzofuran ligands are still
red-shifted when compared to phenyl pyridine iridium complexes (id., Table
1) such that as the Examiner explained, depending on the desired
wavelength, one of ordinary skill in the art would have adjusted the emission
wavelength of the compound. See Ans. 12–13.
We are also not persuaded by Appellant’s argument that the
Examiner’s rationale is contrary to the object and result of the claimed
invention. That is, none of the claims recite emitting green phosphorescence
as argued by Appellant. Appeal Br. 17. In this case, the reasoning behind
the Examiner’s rejection need not be the same as Appellant’s. It is not
necessary that the prior art suggest the combination for the same reason as
contemplated by Appellant. In re Kahn, 441 F.3d 977, 987 (Fed. Cir. 2006).
Moreover, we agree with the Examiner that with respect to the present
claims providing unexpected results, Appellant has not provided sufficient
evidence that the alleged high emission efficiency, high color purity, low
power consumption, and high reliability properties, which are not recited in

4 As a result of this discussion, we find it unnecessary to address the
Examiner’s position that the method used to measure the emission spectra
are different as well as the propriety of the Examiner’s further reliance on
Bazan et al. (US 2004/0142206 A1) in the Answer for support. Ans. 12; see
Appeal Br. 20; Reply Br. 7–8.
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the claims, would have been unexpected. Ans. 11. That is, although the
Specification discusses the effect of the electron withdrawing nitrogen group
adjacent to the carbon atom bonded to the metal in the azadibenzofuran
group (Spec. ¶¶ 76, 116, 117), we have not been directed to sufficient
evidence that this effect would have been an unexpected.
Accordingly, we affirm the Examiner’s rejection of claims 1, 3–12,
14–23, and 26–31 as obvious over Seo and Beers.

Rejection 2
Appellant does not set forth separate arguments with respect to claims
24 and 25, the subject of Rejection 2, but rather appears to rely on the
dependency of these claims as a basis for patentability. Accordingly, we
affirm the Examiner’s rejection of claims 24 and 25 for similar reasons as
discussed above with respect to claim 1.

DECISION SUMMARY
In summary:
Claims
Rejected
35 U.S.C.
§
Reference(s)/Basis Affirmed Reversed
1, 3–12, 14–
23, 26–31
103 Seo, Beers 1, 3–12, 14–
23, 26–31

24, 25 103 Seo, Beers,
Kwong, Alleyne
24, 25
Overall
Outcome
1, 3–12, 14–
31

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Application 14/867,535

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TIME PERIOD FOR RESPONSE
No time period for taking any subsequent action in connection with
this appeal may be extended under 37 C.F.R. § 1.136(a). See 37 C.F.R.
§ 1.136(a)(1)(iv).

AFFIRMED