DETAILED ACTION
Notice of Pre-AIA or AIA Status
The present application, filed on or after March 16, 2013, is being examined under the first inventor to file provisions of the AIA .
Election/Restrictions
Applicant’s election without traverse of Group 1, claims 1-12, in the reply filed on 11/21/2025 is acknowledged.
Status of the Application
Claims 1-14 remain pending in this application. Claims 13 and 14 are withdrawn.
Priority
Receipt is acknowledged of certified copies of papers required by 37 CFR 1.55.
Claim Rejections - 35 USC § 112
The following is a quotation of 35 U.S.C. 112(b):
(b) CONCLUSION.—The specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the inventor or a joint inventor regards as the invention.
Claim 10 is rejected under 35 U.S.C. 112(b) or 35 U.S.C. 112 (pre-AIA ), second paragraph, as being indefinite for failing to particularly point out and distinctly claim the subject matter which the inventor or a joint inventor (or for applications subject to pre-AIA 35 U.S.C. 112, the applicant), regards as the invention.
Regarding claim 10, it recites the limitation "the optical index of the medium which extends above the grating" in lines 3 and 4. There is insufficient antecedent basis for this limitation in the claim. For the purpose of compact prosecution, the Examiner interprets this to mean “an optical index of a medium which extends above the grating”, in which case proper antecedent basis is established.
Claim Rejections - 35 USC § 103
The following is a quotation of 35 U.S.C. 103 which forms the basis for all obviousness rejections set forth in this Office action:
A patent for a claimed invention may not be obtained, notwithstanding that the claimed invention is not identically disclosed as set forth in section 102, if the differences between the claimed invention and the prior art are such that the claimed invention as a whole would have been obvious before the effective filing date of the claimed invention to a person having ordinary skill in the art to which the claimed invention pertains. Patentability shall not be negated by the manner in which the invention was made.
Claims 1, 4 and 11 are rejected under 35 U.S.C. 103 as being unpatentable over Jang et al (US 20100133570 A1, hereafter Jang) in view of Sano et al (US 20100091376 A1, hereafter Sano).
Regarding claim 1, Jang teaches: An optoelectronic device (Jang 100/200, ¶0029, 0041, figs 1, 2) comprising:
an emissive structure (Jang 120, ¶0029, fig 1)
at least a part of which is formed of one or more semiconductor materials (Jang ¶0030, “semiconductor layers 101 and 103 and the active layer 102 of the light emission structure 120”),
configured to produce a luminous radiation when the emissive structure has an electric current flowing therethrough (Jang ¶0030, “active layer 102 generates light by the recombination of electron-hole pairs”), said luminous radiation being produced within the emissive structure (Jang ¶0034, fig 1, generated in 102) and having an average wavelength λ (Jang ¶0005, “blue light”, MPEP 2112.01),
the emissive structure having an average optical index n (Jang ¶0006, 0035, MPEP 2112.01) and being delimited by an outlet surface (Jang top surface of 103/203, fig 1, 2, ¶0032, 0035), through which at least a part of said luminous radiation exits (Jang fig 1, ¶0035), and
an optical structure (Jang “light extraction patterns”, 103a, 103b, “grooves”, ¶0032, 0058) located at the outlet surface (Jang fig 1, 4D),
wherein the optical structure comprises a periodic grating (Jang “grooves”, 103a, 103b) which includes hallow parts (Jang “grooves”, ¶0033, 0058, fig 4D) and protruding parts (Jang 103a, 103b, ¶0032, fig 1) forming a regular periodic structure with a pitch (a)(Jang ¶0036, “spaced from each other at an interval ranging from 0.05 µm to 1.5 µm”, fig 1, 4D).
Jang does not explicitly teach: an antireflective structure comprising a sub-wavelength periodic grating with a pitch (a) lower than λ/[2.n].
Sano, in the same field of endeavor of semiconductor device manufacturing, teaches: an antireflective structure (Sano ¶0005-0006) comprising a sub-wavelength (Sano ¶0053, “pitch smaller than the wavelength λ”) periodic grating (Sano 012, 012a, 012b, fig 1) with a pitch (a)(Sano P, ¶0038).
It would have been obvious to one of ordinary skill in the art, before the effective filing date of the claimed invention, to adjust the pitch of the optical structure of Jang, such that it is in the lower range of the pitch as taught by Jang (I), and such that it has “a pitch (a) lower than λ/[2.n]”, and there by such that the optical structure of Jang is “an antireflective structure comprising a sub-wavelength periodic grating”, as taught by Sano, in order to optimize for incident angle characteristics (San ¶0048).
Examiner’s note: Jang, in at least one embodiment teaches blue light emission from a GaN active layer (Jang ¶0005, 0030). Therefore, for n=2.45 at λ=450 nm, (a) = λ/[2.n] = (450nm)/[2*2.45] = (450nm)/[4.9] ≈ 91.8 nm = 0.0918 µm, which is within the range of 0.05 – 1.5 µm (Jang ¶0036). For completeness of the record, Desieres (US 20170005230 A1) discloses GaN having an index of refraction n=2.45 at λ=450 nm. A person of ordinary skill in the art would recognize 450nm to be blue light. Therefore, under MPEP 2112.01 Jang must have the same properties.
Regarding claim 4, Jang in view of Sano teaches: The device according to claim 1, wherein the emissive structure (Jang 120) includes a superficial upper layer (Jang 103), formed of a semiconductor material (Jang ¶0030, “semiconductor layers … 103”), and wherein the protruding parts (Jang 103a, 103b) of said grating (Jang “grooves”, 103a, 103b), formed of the same semiconductor material as said superficial upper layer (Jang ¶0032, 0056, 103 is etched to form grating), are as one piece with the upper layer of the emissive structure (Jang ¶0056-0058, fig 4C-4D, monolithically formed by etching).
Regarding claim 11, Jang in view of Sano teaches: The device according to claim 1, the device being a light-emitting diode (Jang ¶0029), wherein the emissive structure (Jang 120) comprises:
a lower layer (Jang 101, ¶0030) formed at least in part of a doped semiconductor (Jang ¶0030, “first … conductivity type semiconductor layers 101 … doped with n-type impurities”),
an upper layer (Jang 103, ¶0030) formed at least in part of a doped semiconductor (Jang ¶0030, “second conductivity type semiconductor layers … 103 … doped with … p-type impurities”), the lower and upper layers having opposite type doing (Jang ¶0030, n-type and p-type), and
an emissive part (Jang 102, ¶0030) which extends between the lower layer and the upper layer (Jang fig 1) and which is capable of emitting said luminous radiation when it has an electric current flowing therethrough (Jang ¶0030, “active layer 102 generates light by the recombination of electron-hole pairs”).
Claims 2, 3, and 12 are rejected under 35 U.S.C. 103 as being unpatentable over Jang et al (US 20100133570 A1, hereafter Jang) in view of Sano et al (US 20100091376 A1, hereafter Sano), as applied to claim 1 above, and further in view of Herner (US 20210305464 A1, hereafter Herner).
Regarding claim 2, Jang in view of Sano teaches: The device according to claim 1.
Jang in view of Sano does not explicitly teach: wherein an area occupied by the outlet surface of the emissive structure is lower than 50 µm2.
Herner, in the same field of endeavor of semiconductor device manufacturing, teaches: a microLED (Herner 500) with an area of 25 µm2 (Herner ¶0071, lateral dimensions A1 and A2 of 5 µm results in an area of 25 µm2).
It would have been obvious to one of ordinary skill in the art, before the effective filing date of the claimed invention, to adjust the area of the emissive structure of Jang in view of Sano, as taught by Herner, such that “an area occupied by the outlet surface of the emissive structure is lower than 50 µm2”, in order to increase the pixel density of a device (Herner ¶0051).
Further, one of ordinary skill in the art would have been led to the recited dimensions through routine experimentation and optimization. Applicant has not disclosed that the area occupied by the outlet surface of the emissive structure is for a particular unobvious purpose, produces an unexpected result, or is otherwise critical, and it appears prima facie that the device would possess utility using another area. It has been held that mere dimensional limitations are prima facie obvious absent a disclosure that the limitations are for a particular unobvious purpose, produce an unexpected result, or are otherwise critical (MPEP 2144.04).
Regarding claim 3, Jang in view of Sano and Herner teaches: The device according to claim 2.
Jang in view of Sano and Herner does not explicitly teach: wherein the area is lower than 5 µm2.
Herner further teaches: a lateral dimension of a microLED (Herner 500) with a value less than 5 µm (Herner ¶0071, “dimensions A1 and A2 … 5 microns, or even smaller values”).
It would have been obvious to one of ordinary skill in the art, before the effective filing date of the claimed invention, to further adjust the area of the emissive structure of Jang in view of Sano and Herner, as taught by Herner, such that “the area is lower than 5 µm2”, in order to increase the pixel density of a device (Herner ¶0051).
Further, one of ordinary skill in the art would have been led to the recited dimensions through routine experimentation and optimization. Applicant has not disclosed that the area is for a particular unobvious purpose, produces an unexpected result, or is otherwise critical, and it appears prima facie that the device would possess utility using another area. It has been held that mere dimensional limitations are prima facie obvious absent a disclosure that the limitations are for a particular unobvious purpose, produce an unexpected result, or are otherwise critical (MPEP 2144.04).
Regarding claim 12, Jang in view of Sano teaches: The optoelectronic device according to claim 1.
Jang in view of Sano does not explicitly teach: A display screen comprising an array of optoelectronic devices.
Herner, in the same field of endeavor of semiconductor device manufacturing, teaches: a display comprise and array of optoelectronic devices (Herner ¶0002, 0051).
It would have been obvious to one of ordinary skill in the art, before the effective filing date of the claimed invention, to arrange the optoelectronic devices of Jang in view of Sano into an array as taught by Herner, and such that they form “A display screen comprising an array of optoelectronic devices each in accordance with claim 1”, in order to achieve a higher display resolution (Herner ¶0004, 0051), wherein each optoelectronic device in the array provides improved light extraction (Jang ¶0003, 0008).
Claims 5-7, 9 and 10 are rejected under 35 U.S.C. 103 as being unpatentable over Jang et al (US 20100133570 A1, hereafter Jang) in view of Sano et al (US 20100091376 A1, hereafter Sano), as applied to claims 1 or 4 above, and further in view of Hoshi (US 20030156325 A1, hereafter Hoshi).
Regarding claim 5, Jang in view of Sano teaches: The device according to claim 4, wherein:
the protruding parts (Jang 103a, 103b) of the grating (Jang “grooves”, 103a, 103b) are formed of a material having an optical index np (Jang ¶0032, 103 is comprised of GaN, which inherently possess a refractive index as a material property),
a medium (Jang “air”, ¶0033) of optical index nout (air inherently possess a refractive index as a material property) extends above the grating (Jang fig 1, ¶0033),
a medium (Jang “air”, ¶0033) of index nr (air inherently possess a refractive index as a material property) fills the hollow parts (Jang “grooves”) of the grating (Jang ¶0033, fig 1), and
a filling factor FF of the grating, equal to the fraction of the volume of the grating occupied by its hallow parts (Jang ¶0036, grating patterns “spaced from each other at an interval” defining a pitch; the ratio for hollow volume to total grating volume constitutes an inherent filling factor for any periodic grating structure).
Jang in view of Sano does not explicitly teach: a filling factor FF of the grating is equal to the filling factor FFTE given by the following formula F1:
F
F
T
E
∙
n
r
2
+
1
-
F
F
T
E
∙
n
p
2
=
n
.
n
o
u
t
.
Hoshi, in the same field of endeavor of semiconductor device manufacturing, teaches: a filling factor defined as FF = w/Λ (Hoshi ¶0012, 0073), and the effective medium theory for TE mode polarized light as
n
T
E
=
n
s
2
F
F
+
n
i
2
1
-
F
F
(Hoshi ¶0071-0073).
It would have been obvious to one of ordinary skill in the art, before the effective filing date of the claimed invention, to select a filling factor FF satisfying the above formula in order to optimize optical performance of the grating (Hoshi ¶0119).
Further, absent a showing of criticality with respect to the filling factor (a result effective variable), it would have been obvious to one of ordinary skill in the art, before the effective filing date of the claimed invention, to adjust pitch (a) through routine experimentation in order to achieve improved optical performance. It has been held that discovering an optimum value of a result effective variable involves only routine skill in the art. (MPEP 2144.05). Hoshi discloses that the effective refractive index is determined by the filling factor FF (Hoshi ¶0072), which itself is determined by the grating pitch and width (Hoshi ¶0073), both adjustable geometric parameters.
Regarding claim 6, Jang in view of Sano teaches: The device according to claim 1, wherein:
the protruding parts (Jang 103a, 103b) of the grating (Jang “grooves”, 103a, 103b) are formed of a material having an optical index np (Jang ¶0032, 103 is comprised of GaN, which inherently possess a refractive index as a material property),
a medium (Jang “air”, ¶0033) of optical index nout (air inherently possess a refractive index as a material property) extends above the grating (Jang fig 1, ¶0033),
a medium (Jang “air”, ¶0033) of index nr (air inherently possess a refractive index as a material property) fills the hollow parts (Jang “grooves”) of the grating (Jang ¶0033, fig 1), and
a filling factor FF of the grating, equal to the fraction of the volume of the grating occupied by its hallow parts (Jang ¶0036, grating patterns “spaced from each other at an interval” defining a pitch; the ratio for hollow volume to total grating volume constitutes an inherent filling factor for any periodic grating structure).
Jang in view of Sano does not explicitly teach: a filling factor FF of the grating is equal to the filling factor FFTE given by the following formula F1:
F
F
T
E
∙
n
r
2
+
1
-
F
F
T
E
∙
n
p
2
=
n
.
n
o
u
t
.
Hoshi, in the same field of endeavor of semiconductor device manufacturing, teaches: a filling factor defined as FF = w/Λ (Hoshi ¶0012, 0073), and the effective medium theory for TE mode polarized light as
n
T
E
=
n
s
2
F
F
+
n
i
2
1
-
F
F
(Hoshi ¶0071-0073).
It would have been obvious to one of ordinary skill in the art, before the effective filing date of the claimed invention, to select a filling factor FF satisfying the above formula in order to optimize optical performance of the grating (Hoshi ¶0119).
Further, absent a showing of criticality with respect to the filling factor (a result effective variable), it would have been obvious to one of ordinary skill in the art, before the effective filing date of the claimed invention, to adjust pitch (a) through routine experimentation in order to achieve improved optical performance. It has been held that discovering an optimum value of a result effective variable involves only routine skill in the art. (MPEP 2144.05). Hoshi discloses that the effective refractive index is determined by the filling factor FF (Hoshi ¶0072), which itself is determined by the grating pitch and width (Hoshi ¶0073), both adjustable geometric parameters.
Regarding claim 7, Jang in view of Sano and Hoshi teaches: The device according to claim 6, wherein the grating (Jang “grooves”, 103a, 103b, similar to Hoshi 31) is one-dimensional (Jang fig 1, Hoshi ¶0009, 0012, fig 39), the hollow parts (Jang “grooves”, similar to Sano 012b and Hoshi 32) being rectilinear grooves parallel to each other (Jang fig 1, Hoshi fig 39), and wherein said radiation has a substantially rectilinear polarization (Hoshi ¶0071, TE polarized light, fig 28A), and parallel to said grooves (Hoshi ¶0071, “light having a polarization component perpendicular to the periodic direction of a grating of the minute periodic structure is represented by TE polarized light”, fig 28A).
Regarding claim 9, Jang in view of Sano teaches: The device according to claim 1, wherein:
the protruding parts (Jang 103a, 103b) of the grating (Jang “grooves”, 103a, 103b) are formed of a material having an optical index np (Jang ¶0032, 103 is comprised of GaN, which inherently possess a refractive index as a material property),
a medium (Jang “air”, ¶0033) of optical index nout (air inherently possess a refractive index as a material property) extends above the grating (Jang fig 1, ¶0033),
a medium (Jang “air”, ¶0033) of index nr (air inherently possess a refractive index as a material property) fills the hollow parts (Jang “grooves”) of the grating (Jang ¶0033, fig 1), and
a filling factor FF of the grating, equal to the fraction of the volume of the grating occupied by its hallow parts (Jang ¶0036, grating patterns “spaced from each other at an interval” defining a pitch; the ratio for hollow volume to total grating volume constitutes an inherent filling factor for any periodic grating structure).
Jang in view of Sano does not explicitly teach: the grating is one-dimensional, the hollow parts being rectilinear grooves parallel to each other, and said radiation has a substantially rectilinear polarization perpendicular to said grooves, and wherein
a filling factor FF of the grating is equal to the filling factor FFTM given by the following formula F2:
F
F
T
M
∙
n
r
-
2
+
1
-
F
F
T
M
∙
n
p
-
2
-
1
=
n
.
n
o
u
t
.
Hoshi, in the same field of endeavor of semiconductor device manufacturing, teaches: a one-dimensional grating (Hoshi ¶0009, 0012, fig 39) having hollow parts (Hoshi 32) being rectilinear grooves parallel to each other (Hoshi fig 39, ¶0071), and radiation has a substantially rectilinear polarization perpendicular to said grooves (Hoshi ¶0071, TM polarized light, fig 28A), and wherein
a filling factor defined as FF = w/Λ (Hoshi ¶0012, 0073), and the effective medium theory for TM mode polarized light as
n
T
M
=
1
n
s
2
F
F
+
1
n
i
2
1
-
F
F
-
1
(Hoshi ¶0071-0073).
It would have been obvious to one of ordinary skill in the art, before the effective filing date of the claimed invention, to modify Jang in view of Sano such that the grating is “one-dimensional, the hollow parts being rectilinear grooves parallel to each other, and said radiation has a substantially rectilinear polarization perpendicular to said grooves”, in order to target a specific polarization (Hoshi ¶0071-0072), and to select a filling factor FF satisfying the above formula in order to optimize optical performance of the grating (Hoshi ¶0119).
Further, absent a showing of criticality with respect to the filling factor (a result effective variable), it would have been obvious to one of ordinary skill in the art, before the effective filing date of the claimed invention, to adjust pitch (a) through routine experimentation in order to achieve improved optical performance. It has been held that discovering an optimum value of a result effective variable involves only routine skill in the art. (MPEP 2144.05). Hoshi discloses that the effective refractive index is determined by the filling factor FF (Hoshi ¶0072), which itself is determined by the grating pitch and width (Hoshi ¶0073), both adjustable geometric parameters.
Regarding claim 10, Jang in view of Sano teaches: The device according to claim 1, wherein the grating has a depth D (Jang “predetermined depth”, ¶0056, fig 4B), along a direction perpendicular to the outlet surface (Jang fig 4B-D); and a medium (Jang “air”, ¶0033) of optical index nout (air inherently possess a refractive index as a material property) which extends above the grating (Jang fig 1, ¶0033).
Jang in view of Sano does not explicitly teach: the depth D being equal to
λ
/
4
n
∙
n
o
u
t
, nout being the optical index of the medium (as best understood to mean “an optical index of a medium which extends above the grating”) which extends above the grating, opposite to the emissive structure.
Hoshi, in the same field of endeavor of semiconductor device manufacturing, teaches: adjusting a grating depth to be an integral multiple of
λ
/
4
(Hoshi ¶0143).
It would have been obvious to one of ordinary skill in the art, before the effective filing date of the claimed invention, to adjust the grating of Jang in view of Sano such that “the depth D being equal to
λ
/
4
n
∙
n
o
u
t
"
in order to obtain an antireflective effect (Hoshi ¶0139, 0143).
Further, absent a showing of criticality with respect to the depth (a result effective variable), it would have been obvious to one of ordinary skill in the art, before the effective filing date of the claimed invention, to adjust the grating depth through routine experimentation in order to achieve improved antireflective properties. It has been held that discovering an optimum value of a result effective variable involves only routine skill in the art. (MPEP 2144.05).
Claim 8 is rejected under 35 U.S.C. 103 as being unpatentable over Jang et al (US 20100133570 A1, hereafter Jang) in view of Sano et al (US 20100091376 A1, hereafter Sano) and Hoshi (US 20030156325 A1, hereafter Hoshi), as applied to claim 6 above, and further in view of Hirasawa et al (US 20170284609 A1, hereafter Hirasawa).
Regarding claim 8, Jang in view of Sano and Hoshi teaches: The device according to claim 6.
Jang in view of Sano and Hoshi does not explicitly teach: wherein the grating is a two-dimensional grating including a pattern periodically repeated along a first direction, and also periodically repeated along a second direction different from the first direction.
Hirasawa, in the same field of endeavor of semiconductor device manufacturing, teaches: a two-dimensional periodic structure (Hirasawa 120D, ¶0234) periodically repeated along a first direction (Hirasawa x dir), and also periodically repeated along a second direction (Hirasawa y dir) different from the first direction (Hirasawa fig 18A, ¶0234).
It would have been obvious to one of ordinary skill in the art, before the effective filing date of the claimed invention, to modify the grating of Jang in view of Sano and Hoshi, such that it comprises a two-dimensional grating, and such that it includes “a pattern periodically repeated along a first direction, and also periodically repeated along a second direction different from the first direction”, as taught by Hirasawa, in order to apply effects of the grating to both the TE and TM polarized light components (Hirasawa ¶0234, Hoshi ¶0143-0144), thereby improving light extraction efficiency.
Conclusion
The prior art made of record and not relied upon is considered pertinent to applicant's disclosure:
Desieres (US 20170005230 A1) is cited as an example of an analogous device.
Any inquiry concerning this communication or earlier communications from the examiner should be directed to NICHOLAS B. MICHAUD whose telephone number is (703)756-1796. The examiner can normally be reached Monday-Friday, 0800-1700 Eastern Time.
Examiner interviews are available via telephone, in-person, and video conferencing using a USPTO supplied web-based collaboration tool. To schedule an interview, applicant is encouraged to use the USPTO Automated Interview Request (AIR) at http://www.uspto.gov/interviewpractice.
If attempts to reach the examiner by telephone are unsuccessful, the examiner’s supervisor, EVA MONTALVO can be reached at (571) 272-3829. The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300.
Information regarding the status of published or unpublished applications may be obtained from Patent Center. Unpublished application information in Patent Center is available to registered users. To file and manage patent submissions in Patent Center, visit: https://patentcenter.uspto.gov. Visit https://www.uspto.gov/patents/apply/patent-center for more information about Patent Center and https://www.uspto.gov/patents/docx for information about filing in DOCX format. For additional questions, contact the Electronic Business Center (EBC) at 866-217-9197 (toll-free). If you would like assistance from a USPTO Customer Service Representative, call 800-786-9199 (IN USA OR CANADA) or 571-272-1000.
/NICHOLAS B. MICHAUD/
EXAMINER
Art Unit 2818
/Mounir S Amer/Primary Examiner, Art Unit 2818