PILKINGTON GROUP LIMITED

Patent Trials and Appeals Board

May 28, 2021

2020003873 (P.T.A.B. May. 28, 2021)

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.
14/999,853 07/11/2016 SRIKANTH VARANASI 1-23340 2732
1678 7590 05/28/2021
MARSHALL & MELHORN, LLC
FOUR SEAGATE - EIGHTH FLOOR
TOLEDO, OH 43604
EXAMINER
RAKOWSKI, CARA E
ART UNIT PAPER NUMBER
2872
NOTIFICATION DATE DELIVERY MODE
05/28/2021 ELECTRONIC
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.
Notice of the Office communication was sent electronically on above-indicated "Notification Date" to the
following e-mail address(es):
PatentDocket@marshall-melhorn.com
may@marshall-melhorn.com
schurr@marshall-melhorn.com
PTOL-90A (Rev. 04/07)
UNITED STATES PATENT AND TRADEMARK OFFICE
BEFORE THE PATENT TRIAL AND APPEAL BOARD
Ex parte SRIKANTH VARANASI
Appeal 2020-003873
Application 14/999,853
Technology Center 2800
Before JEFFREY T. SMITH, LINDA M. GAUDETTE, and
JENNIFER R. GUPTA, Administrative Patent Judges.
SMITH, Administrative Patent Judge.
DECISION ON APPEAL
STATEMENT OF THE CASE
Pursuant to 35 U.S.C. § 134(a), Appellant1 appeals from the
Examiner’s decision to reject claims 1, 3–5, 7, 8, 11, 12, and 16–22. (Final
Act. 1.) We have jurisdiction under 35 U.S.C. § 6(b).
We REVERSE.

1 The term “Appellant” refers to “applicant” as defined in 37 C.F.R.
§ 1.42. Appellant identifies the real party in interest as Pilkington Group
Limited, the assignee of record, which is a wholly owned subsidiary of
Nippon Sheet Glass Co., Ltd. (Appeal Br. 3.)
Appeal 2020-003873
Application 14/999,853

2
CLAIMED SUBJECT MATTER
The claims are directed to a coated glass article having an anti-
reflective coating. Spec. 1. Claim 1, reproduced below, is illustrative of the
claimed subject matter:
1. A coated glass article comprising:
a glass substrate; and
a coating formed over the glass substrate, wherein the
coating comprises:
a first inorganic metal oxide layer comprising titanium
dioxide and deposited over a major surface of the glass substrate,
wherein the first inorganic metal oxide layer is a pyrolytic
coating deposited at a thickness of 5–25 nm and has a refractive
index of 1.6 or more,
a second inorganic metal oxide layer comprising silicon
dioxide and deposited over the first inorganic metal oxide layer
at a thickness of 20–40 nm, wherein the second inorganic metal
oxide layer has a refractive index which is less than the refractive
index of the first inorganic metal oxide layer,
a third inorganic metal oxide layer comprising titanium
dioxide and deposited over the second inorganic metal oxide
layer at a thickness of 30 nm or less, wherein the third inorganic
metal oxide layer has a refractive index of 2.2 or more and
wherein the refractive index of the third inorganic metal oxide
layer is greater than the refractive index of the second inorganic
metal oxide layer, and
a fourth inorganic metal oxide layer comprising silicon
dioxide and deposited over the third inorganic metal oxide layer
at a thickness of 80 nm or more, wherein the fourth inorganic
metal oxide layer has a refractive index which is less than the
refractive index of the third inorganic metal oxide layer;
wherein the coated glass article exhibits a total visible light
reflectance of less than 6.5%.
Appeal 2020-003873
Application 14/999,853

3
REFERENCES
The prior art relied upon by the Examiner is:
Name Reference Date
Szczyrbowski US 5,170,291 Dec. 8, 1992
Laird US 6,074,730 June 13, 2000
Varanasi US 2006/0188730 A1 Aug. 24, 2006
Meredith US 2008/0028984 A1 Feb. 7, 2008
Macleod The Essential Macleod,
Archived webpage
downloaded from the
wayback machine
February 17, 2019
Jan. 2006

REJECTIONS
I. Claims 1, 3–5, 7, 8, 11, 12, and 16–19 are rejected under 35 U.S.C.
§ 103 as being unpatentable over the combination of Szczyrbowski, Laird,
and Macleod. (Final Act. 3,)
II. Claims 20 and 21 are rejected under 35 U.S.C. § 103 as being
unpatentable over the combination of Szczyrbowski, Laird, Macleod, and
Varanasi. (Final Act. 19)
III. Claim 22 is rejected under 35 U.S.C. § 103 as being unpatentable
over the combination of Szczyrbowski, Laird, Macleod, and Meredith.
(Final Act. 21.)
OPINION
After review of the respective positions Appellant provides in the
Appeal Brief and the Examiner provides in the Final Office Action and the
Answer, we reverse the Examiner’s prior art rejection of claims 1, 3–5, 7, 8,
11, 12, and 16–22 under 35 U.S.C. § 103 for the reasons Appellant provides.
We add the following.
Appeal 2020-003873
Application 14/999,853

4
The dispositive issue for this appeal is:
Did the Examiner err in determining that Szczyrbowski and Laird
describe or suggest a coated glass article comprising a four layer
antireflective coating wherein the first inorganic metal oxide layer comprises
titanium dioxide and the third inorganic metal oxide layer comprises
titanium dioxide deposited over the second inorganic metal oxide layer at a
thickness of 30 nm or less as required by independent claims 1 and 12?2
We answer this question in the affirmative.
The Examiner finds Szczyrbowski teaches a glass article comprising
an antireflective coating having layers in the following sequence: titanium
dioxide (first layer), silicon dioxide (second layer), titanium dioxide (third
layer), and silicon dioxide (fourth layer). (Final Act. 3–4.) The Examiner
finds Szczyrbowski differs from the claimed invention by failing to teach the
third layer has a thickness of 30 nm or less as required by the claims. (Final
Act. 4.) The Examiner finds Laird teaches a coated glass article having a
structure similar to Szczyrbowski. (Final Act. 4–6.) The Examiner finds
Laird discloses the suitable medium index materials for the first layer has
refractive indices in the range of 1.9 to 2.1 and recognizes the refractive
index of titanium dioxide is 2.6, which is outside the desired range. (Final
Act. 4–5.) The Examiner finds Laird’s third layer (titanium dioxide), as
depicted in tables 1 and 2, has a thickness of less than 30 nm (specifically
23.2 nm and 26 nm respectively). (Final Act. 5–6.) The Examiner concludes:
[I]t would have been obvious to one of ordinary skill in the art
before the effective filing date of the claimed invention to
choose the thickness of the third layer of a 4 layer antireflection

2 The Examiner cites the Macleod, Varanasi, and Meredith references to
address limitations not related to the dispositive issue.
Appeal 2020-003873
Application 14/999,853

5
coating to be less than 30 nm as taught by Laird, because Laird
teaches that having a thinner third layer results in a thinner and
more economical AR coating. Furthermore refining the
thickness of an existing layer in an AR coating, based on the
teachings of Szczyrbowski and Laird would have been obvious
since it has been held that where the general conditions of a
claim are disclosed in the prior art, discovering the optimum or
workable ranges involves only routine skill in the art, In re
Aller, 105 USPQ 233 (C.C.P.A. 1955). In the current instance,
the thickness of each of the layers including the first layer is an
art recognized results effective variable in that it contributes to
the optical properties of the overall film. Thus one would have
been motivated to optimize the thickness of the first layer
because it is an art-recognized result-effective variable and it
has been held that discovering an optimum value of a result
effective variable involves only routine skill in the art, In re
Antonie, 559 F.2d 618, 195 USPQ 6 (CCPA 1977).
(Final Act. 7.)
Claim 1 is directed to a coated glass article comprising a coating that
comprises a first inorganic metal oxide layer comprising titanium dioxide
deposited at a thickness of 5–25 nm and a third inorganic metal oxide layer
comprising titanium dioxide that has a thickness of 30 nm or less.
Szczyrbowski teaches that the various layer thickness is selected within the
cited layer thickness tolerances. Szczyrbowski specifically states:
Regarding the layer thicknesses it is suggested that the
first layer has a thickness of 100 angstrom ± 10%; that the
second layer has a thickness of 400 angstrom ±5%; that the
third layer has a thickness of 1040 angstrom ±2%; and that the
fourth layer has a thickness of 940 angstrom ±2%. These values
for the respective layer thicknesses are selected within the cited
layer thickness tolerances that take into consideration the
interdependencies between the individual layer thicknesses and
the materials being used in the layers.
Szczyrbowski col. 3 ll. 15–25.
Appeal 2020-003873
Application 14/999,853

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The Examiner has proposed modifying the thickness of
Szczyrbowski’s third layer with the third layer thickness taught by Laird.
However, Szczyrbowski teaches the object of the invention is to reduce
manufacturing costs and produce coated articles that exhibits a visible light
reflectance that is less than 1 % for the majority of the visible light region of
the electromagnetic spectrum. Col. 3, ll. 60–65, col. 5, ll. 37–40.
Szczyrbowski specifically teaches the “values for the respective layer
thicknesses are selected within the cited layer thickness tolerances that take
into consideration the interdependencies between the individual layer
thicknesses and the materials being used in the layers.” Col. 3 ll. 20–25. The
Examiner has not adequately explained how following the teaching of Laird
for the thickness of the third layer would affect the visible light reflectance
properties required by Szczyrbowski. The Examiner also has not adequately
explained why one of ordinary skill in the art would follow the teachings of
Laird for modifying Szczyrbowski’s third layer thickness, but not follow the
teachings of Szczyrbowski that the individual layer thicknesses are
interdependent.
Accordingly, we REVERSE the Examiner’s prior art rejection of
claims 1, 3–5, 7, 8, 11, 12, and 16–22 under 35 U.S.C. § 103 for the reasons
Appellant presents and we give above.
Appeal 2020-003873
Application 14/999,853

7
DECISION SUMMARY
Claim(s)
Rejected
35 U.S.C.
§
Reference(s)/Basis Affirmed Reversed
1, 3–5, 7, 8,
11, 12, 16–
19
103 Szczyrbowski,
Laird, Macleod
1, 3–5, 7, 8,
11, 12, 16–
19
20, 21 103 Szczyrbowski,
Laird, Macleod,
Varanasi
20, 21
22 103 Szczyrbowski,
Laird, Macleod,
Meredith
22
Overall
Outcome
1, 3–5, 7, 8,
11, 12, 16–
22

REVERSED