Ex Parte Hoffman

Patent Trial and Appeal Board

Jul 25, 2014

12258664 (P.T.A.B. Jul. 25, 2014)

UNITED STATES PATENT AND TRADEMARKOFFICE
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.
12/258,664 10/27/2008 Robert C. Hoffman ARL 05-26 9479
21364 7590 07/28/2014
U S ARMY RESEARCH LABORATORY
ATTN: RDRL-LOC-I
2800 POWDER MILL RD
ADELPHI, MD 20783-1197
EXAMINER
LEGASSE JR, FRANCIS M
ART UNIT PAPER NUMBER
2878
MAIL DATE DELIVERY MODE
07/28/2014 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 ROBERT C. HOFFMAN1
________________

Appeal 2012-009444
Application 12/258,664
Technology Center 2800
________________

Before MARK NAGUMO, JAMES C. HOUSEL, and GEORGE C. BEST,
Administrative Patent Judges.

NAGUMO, Administrative Patent Judge.

DECISION ON APPEAL
Robert C. Hoffman (“Hoffman”) timely appeals
under 35 U.S.C. § 134(a) from the Final Rejection2 of claims 1-5, 11,
and 13.3, 4 We have jurisdiction. 35 U.S.C. § 6. We reverse.

1 The real party in interest is identified as the U.S. Government as
represented by the Secretary of the Army. (Appeal Brief,
filed 21 December 2011 (“Br.”), 1.)
2 Office action mailed 6 October 2011 (“Final Rejection”; cited as “FR”).
3 The Examiner has withdrawn claims 14-20 from examination (FR 1, ¶ 5a),
objected to claim 12 (id. at ¶ 8), and indicated the allowability of
claims 6-10 (id. at ¶ 6) . None of these claims are before us.
App
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Appeal 2012-009444
Application 12/258,664

3
An image 101 is incident on the device, which comprises an active
region 203 sandwiched between two confinement regions, 204 (n-type
semiconductor) and 205 (p-type semiconductor). Active region 203 is
transparent to certain wavelengths comprising image 101 when the device is
biased, i.e., turned on. (Spec. 8 [0036].) However, in the words of
the ʼ664 Specification, “[w]hen the device is turned ‘off,’ emission [of
photons from the recombination of electrons and holes]6 ceases, and the
junction [203] becomes highly absorbing. . . . The extinction coefficient of
the unexcited semiconductor may be approximately 106m-1, depending on
the application and materials utilized.” (Id.; emphasis added.)
Devices incorporating the claimed active optical switching devices are
said to include visual protective light filters “for eliminating predetermined
wavelengths when light, such as a laser beam, is being scanned by the
operator.” (Id. at 3, ll. 3-4.)
Sole independent claim 1 is representative of the dispositive issues
and reads:
An optical device comprising a semiconductor device, said
semiconductor device comprising:
an input portion adapted to receive inputted light and
an output portion adapted to output light;
an n-type region,
a p-type region;
an active region sandwiched between the p-type and n-type
regions wherein

6 Spec. 8 [0035].
Appeal 2012-009444
Application 12/258,664

4
either the p-type or n-type region is adjacent one side of
the active region and the other is adjacent the other side
of the active region,
the active region being
substantially transparent to light of a predetermined
wavelength range when a bias is applied across the
n-type and p-type regions and
substantially opaque to light within a predetermined
wavelength range when a bias is not applied
across the n-type and p-type regions.
(Claims App., Br. 16; some indentation, paragraphing, and emphasis added.)
The Examiner maintains the following ground of rejection:7
Claims 1-5, 11, and 13 stand rejected under 35 U.S.C. § 103(a) in
view of the combined teachings of Fedotowsky8 and Wong.9
B. Discussion
Findings of fact throughout this Opinion are supported by a
preponderance of the evidence of record.
The Examiner finds that Fedotowsky describes, in Figure 7, which is
reproduced on the following page, a structure that contains all the elements
required by claim 1, including an active region 77, 78, sandwiched between
a p-type region 71 and an n-type region 72, with a bias applied across the
device. The Examiner finds that Fedotowsky does not disclose that the
active region is substantially opaque to light in a predetermined wavelength

7 Examiner’s Answer mailed 19 March 2012 (“Ans.”).
8 André Fedotowsky and Kurt Lehovec, Electrically modulated radiation
filters, U.S. Patent 3,726,585 (1973).
9 Yu Wong, Devices based on surface plasmon interference filters, U.S.
Patent Application Publication 2002/0036828 A1 (2002).
App
App

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(FR
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09444
/258,664
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ross the n
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Appeal 2012-009444
Application 12/258,664

6
identical result and more importantly provides a power consumption
reduction of the device.” (FR 4, 3d full para.; Ans. 6, 1st para.)
It might be argued that Wong’s disclosure that a selected primary
color can be transmitted when no voltage is applied is also a disclosure that
the material, when biased, is substantially opaque to some other color—i.e.,
a “predetermined wavelength range.” It might also be argued that the most
general definition of the term “opaque” includes “completely reflective” as a
non-transmissive state, although we find no description of such a state
described or suggested in the ʼ664 Specification. Indeed, as Hoffman
argues, the only examples of a substantial opaque material in the ʼ644
Specification is a highly absorptive material, e.g., a material having an
extinction coefficient of up to approximately 106 m-1. (Br., para.
bridging 4-5, citing Spec. 8 [0036].) However, even accepting these broad
interpretations, which appear to underlie the appealed rejections, there
remain serious difficulties with the supporting findings of fact.
In particular, as Hoffman argues (Br. 5. 1st full para.), Wong is
directed to devices based on surface plasmon filters having at least one
metal-dielectric interface to support surface plasmon waves. In contrast,
Fedotowsky is directed to a device comprising a multiplicity of dielectric
layers in which the light beam to be modulated is “incident onto the interface
between two of said [dielectric] layers at or near a critical angle at which the
resonant condition for a multiple reflection wave pattern in one of these
layers is achieved.” (Id., citing Fedotowsky col. 1, ll. 39-44.) Thus, as
Hoffman urges, the devices described by Fedotowsky and the devices
described by Wong are based on substantially dissimilar technologies.
(Br. 5, last para.) There are no conductive layers at the critical interfaces in
Appeal 2012-009444
Application 12/258,664

7
Fedotowsky to support surface plasmon waves. The Examiner has not
explained why persons having ordinary skill in the art would have had a
reason to combine the teachings of Wong with those of Fedotowsky, or a
reasonable expectation of success in so doing.
The Examiner has not made any findings in the prior art regarding
limitations of the dependent claims that cure the defects of the rejection of
the independent claim.
C. Order
We reverse the rejection of claims 1-5, 11, and 13.
REVERSED
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