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 II claims 34-61 and 66-70 in the reply filed is acknowledged. The restriction mailed on May 08, 2026 required restriction to one of the following inventions:
Group I, claims 1-33, drawn to a method of fabrication of an optical waveguide through singulation, and
Group II, claims 34-61 and 66-70, drawn to a display system.
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.
The following is a quotation of 35 U.S.C. 112 (pre-AIA ), second paragraph:
The specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the applicant regards as his invention.
Claim 67 is/are 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 67:
The claim recites “wherein surface features further from said edge have steeper sloping surfaces than surface features closer to said edge of said surface,” which is amendable to two structural readings with varying scope. “Said edge” has antecedent basis in the waveguide edge of claim 34, which extends between major surfaces. The phrasing of the claim requires a surface of either the top and bottom surfaces in claim 34 or the surface oriented at an angle of claim 66. Additionally, specificity on any instance of a surface beyond ‘said surface’ would immediately remedy the uncertainty.
Claim Rejections - 35 USC § 103
In the event the determination of the status of the application as subject to AIA 35 U.S.C. 102 and 103 (or as subject to pre-AIA 35 U.S.C. 102 and 103) is incorrect, any correction of the statutory basis (i.e., changing from AIA to pre-AIA ) for the rejection will not be considered a new ground of rejection if the prior art relied upon, and the rationale supporting the rejection, would be the same under either status.
Claim(s) 34-38, 40-43, 45-61, 68, and 69 is/are rejected under 35 U.S.C. 103 as being unpatentable over Li (US 2020/0400941 A1) in view of Yaras (US 2019/0094551 A1), and further in view of Miller (US 2019/0170932 A1).
Regarding claim 34:
Li teaches a display system (Figure 9D, display 70) configured to be disposed on a user’s head and/or face so as to present images to a user’s eye (Title, Abstract), said display system comprising:
At least one light source configured to produce light (Figure 6, light projector system 520 comprising light module 530 including a light emitting diode);
An eyepiece configured to direct light from said light source to a user’s eye to display image content therein (Figure 6, waveguide assembly 260 referred to as an eyepiece, eye 210), said eyepiece comprising:
at least one waveguide (Figure 22A, waveguide 2202a) having top (2201) and bottom (2203) major surfaces and an edge (2205) extending therebetween,
said waveguide having a main region (Figure 9B, the area of waveguide 2202a bearing outcoupling elements 800, 810, and 820) and a peripheral region surrounding said main region (Figure 22A, the area of gratings 2210a), said peripheral region more proximal to said edge than said main region (2210a extends outwards from edge 2205 across 2 mm to 5 mm of the surface),
said waveguide configured to propagate light from said at least one light source between said top and bottom major surfaces by total internal reflection (Figure 7, light 640 propagates via TIR) and eject at least some of said light out of at least a portion of said main region of said waveguide to said user's eye to present image content thereto (Figure 7, beams 650 are directed to viewer/eye 210),
and a plurality of surface features (Figure 22A, outcoupling optical elements 2220, diffractive gratings) within said peripheral region of said waveguide (see proximity to area of gratings 2210a) configured to couple light propagating in said waveguide out of said waveguide out from said peripheral region (light beams 2206 and 2208 into light absorbing material 2204).
The display system 60 of Fig. 9D “is the system 250 of Figure 6” (paragraph 143), the waveguide assembly of Figure 6 being part of the display 70. The stack of 270, 280, 290, 300, and 310 in Figure 6 is equivalent to the stack 360, 370, 380, 390, 400 of Figures 9. While the light injection source differs in embodiments, the stack referred to is the same.
It would be obvious to one of ordinary skill in the art to apply the Figure 22A edge treatment to a waveguide of the Figures 9A-9C stack. Unutilized light reaches the edge, reflects, and is outcoupled by elements 800, 810, 820 as straight light or ghost images ([234]). Predictably, this results in a waveguide whose unused light is extracted at the periphery rather than returning to the active area.
Li does not expressly teach said surface features having one or more parameters that changes with distance from said edge closest thereto. However, “parameters” broadly refers to spatial, geometric, and material properties of the element that can be changed, and derived optical properties that change as a function of distance are ubiquitous in the art.
Yaras teaches a waveguide eyepiece having a peripheral grating that ejects stray light (Title, Abstract), comprising:
Said waveguide having a main region (interior 122 of primary planar waveguide 108, bearing the diffractive optical elements 110 that shift the angle of light so that it escapes TIR and emerges to the viewer) and a peripheral region (Figure 10, inset A – the band of gratings 1002 along the peripheral edge 1004 of waveguide apparatus 102) surrounding said main region;
Said surface parameters having one or more parameters that changes with distance from said edge closest thereto (paragraphs 51, 75 disclose that the pitch corresponds to wavelengths being 330 nm for blue, 380 nm for green, and 470 nm for red, the pitch being a function of position along the length and thus comprising surface parameters that change with distance to the edge).
Miller additionally teaches an eyepiece waveguide having an edge grating patterns proximal to a singulated edge (Title), comprising:
Figure 8, a grating structure 820 having a narrower pitch 810 and grating 825, nearer the outer edge, having a wider pitch 815 across the edge portion 802.
This constitutes a parameter (pitch width) that changes with distance to the edge.
Before the effective filing date of the claimed invention, one of ordinary skill in the art would have found it obvious to modify the invention described in the invention of Li under the teachings of Yaras and Miller to include one or more parameters that change with distance to the edge (the edge 2205 of Li becomes the reference point, and the Figure 22A edge treatment is applied to a waveguide of the Figures 9A-9C stack; the parameter is pitch or pitch width to correspond to different wavelengths of light and outcouple light as desired). This may be accomplished using materials, machining methods, and design oversight known to a skilled artisan, and would predictably result in a device which is natively capable of precisely directing light based on wavelength due to its constructed geometry.
Regarding claim 35:
Li in view of Yaras, and further in view of Miller teaches the display system of Claim 34, wherein the plurality of surface features comprises a diffractive optical element (Figure 22A, optical elements 2220 are diffraction gratings).
Regarding claim 36:
Li in view of Yaras, and further in view of Miller teaches the display system of Claim 34, wherein the plurality of surface features comprises a diffraction grating (Figure 22A, optical elements 2220 are diffraction gratings).
Regarding claim 37:
Li in view of Yaras, and further in view of Miller teaches the display system of Claim 34.
Li does not teach a blazed grating as claimed.
Yaras teaches a peripheral grating structure for extracting light from a waveguide (Title, abstract), comprising:
wherein the plurality of surface features comprises a blazed grating (Figure 7, optical structures 704 are of a blazed grating, and may be “binary, multi-step, or blazed”).
Before the effective filing date of the claimed invention, one of ordinary skill in the art would have found it obvious to modify the invention described in the rejection of claim 34 above under the teachings of Yaras to form the peripheral surface features as a blazed grating, using surface relief grating profiles known in the art. Predictably, this would result in a device where diffracted stray light is directed preferentially into a single order and away from the main region.
Regarding claim 38:
Li in view of Yaras, and further in view of Miller teaches the display system of Claim 34.
Li does not teach wherein at least one of said surface features has at least one sloping surface.
Yaras teaches a peripheral grating structure for extracting light from a waveguide (Title, Abstract), comprising:
At least one of a plurality of surface features has at least one sloping surface (Figure 3C, Figure 7, optical structures 704 of waveguide 504 may have repeating angled elevations and a cross-section described as a series of right-angle triangles in sequence, as described in paragraph 80)
Before the effective filing date of the claimed invention, one of ordinary skill in the art would have found it obvious to modify the invention described in the rejection of claim 34 above under the teachings of Yaras, to provide the peripheral surface features with an inclined face, using surface-relief grating profiles known in the art. Predictably, this would result in a device where light incident on the inclined face falls below the critical angle and exits the waveguide rather than being actively guided.
Regarding claim 40:
Li in view of Yaras, and further in view of Miller teaches the display system of Claim 34.
Li does not teach wherein a plurality of said surface features have a sawtooth shape.
Yaras teaches a peripheral grating structure for extracting light from a waveguide (Title, Abstract), comprising:
A plurality of surface features having a sawtooth shape (Figure 7, Figure 3C, optical structures 704 have a sawtooth shape)
Before the effective filing date of the claimed invention, one of ordinary skill in the art would have found it obvious to modify the invention described in the rejection of claim 34 above under the teachings of Yaras, to provide the peripheral surface features in a sawtooth shape, using surface-relief grating profiles known in the art. Predictably, this would result in a device where light incident on the inclined face falls below the critical angle and exits the waveguide rather than being actively guided.
Regarding claim 41:
Li in view of Yaras, and further in view of Miller teaches the display system of Claim 34.
Li does not teach wherein a plurality of said surface features have a triangular cross-section orthogonal to the portion of the edge closest thereto.
Yaras teaches a peripheral grating structure for extracting light from a waveguide (Title, Abstract), comprising:
Wherein a plurality of surface features have a triangular cross section (Figure 3C, Figure 7, optical/blazed structures 704 of waveguide 504 may have repeating angled elevations and a cross-section described as a series of right angle triangles in sequence as described in paragraph 80, a triangular cross section) orthogonal to the portion of the edge closest thereto.
Before the effective filing date of the claimed invention, one of ordinary skill in the art would have found it obvious to modify the invention described in the rejection of claim 34 above under the teachings of Yaras, to provide the surface features with a triangular cross section as claimed, using surface-relief grating profiles known in the art. Predictably, this would result in a device where light incident on the inclined face falls below the critical angle and exits the waveguide rather than being actively guided.
Regarding claim 42:
Li in view of Yaras, and further in view of Miller teaches the display system of Claim 34.
Li does not teach wherein the plurality of surface features are asymmetric.
Yaras teaches a peripheral grating structure for extracting light from a waveguide (Title, Abstract), comprising:
Wherein a plurality of surface features are asymmetric (Figure 3C, Figure 7, optical/blazed structures 704 of waveguide 504 may have repeating angled elevations and a cross-section described as a series of right angle triangles in sequence as described in paragraph 80, an asymmetric shape).
Before the effective filing date of the claimed invention, one of ordinary skill in the art would have found it obvious to modify the invention described in the rejection of claim 34 above under the teachings of Yaras, to configure the plurality surface features such that they are asymmetric, using surface-relief grating profiles known in the art. Predictably, this would result in a device where light incident on the inclined face falls below the critical angle and exits the waveguide rather than being actively guided.
Regarding claim 43:
Li in view of Yaras, and further in view of Miller teaches the display system of Claim 34.
Li does not teach wherein a plurality of said surface features are symmetric.
Yaras teaches a peripheral grating structure for extracting light from a waveguide (Title, Abstract), comprising:
A plurality of surface features which are symmetric (Figure 7, Figure 3C, optical structures 704 have a symmetric shape)
Before the effective filing date of the claimed invention, one of ordinary skill in the art would have found it obvious to modify the invention described in the rejection of claim 34 above under the teachings of Yaras, to provide the peripheral surface features in a symmetric shape, using surface-relief grating profiles known in the art. Predictably, this would result in a device where light incident on the inclined face falls below the critical angle and exits the waveguide rather than being actively guided.
Regarding claim 45:
Li in view of Yaras, and further in view of Miller teaches the display system of Claim 34.
Li does not teach wherein the plurality of surface features has an average height in a range from 100 to 500 high.
Yaras teaches a peripheral grating structure for extracting light from a waveguide (Title, Abstract), comprising:
wherein the plurality of surface features has an average height in a range from 100 to 500 nanometers high (paragraphs 75, 99, Figure 7 and Figure 10 teach that gratings have pitches of 330 nm, 380 nm, and 470 nm for blue, green, and red light respectively. Each value falls within the claimed range).
Before the effective filing date of the claimed invention, one of ordinary skill in the art would have found it obvious to modify the invention described in the rejection of claim 34 above under the teachings of Yaras to ensure that the height of said surface features is anywhere from 100 to 500 nm high. This may be accomplished using surface relief grating manufacturing methods known in the art, and would predictably result in a device where the peripheral band diffracts visible light at the angles required to break total internal reflection.
Regarding claim 46:
Li in view of Yaras, and further in view of Miller teaches the display system of claim 34, wherein:
Li does not teach the FWHM as claimed.
Yaras teaches a peripheral grating structure for extracting light from a waveguide (Title; Abstract), comprising:
Wherein the plurality of surface features has an average full width at half max in a range from 75-250 nm (Figure 7, paragraph 0075, gratings that are binary, alternating between two elevations in a stepwise manner at a cycle of 50% and with pitches of 330, 380, and 470 nm)
For a binary grating of period T at a 50% duty cycle, each ridge is rectangular in cross section, so its width as measured is approximately half the pitch (i.e. 165, 190, and 235 nm, respectively). This falls within the claimed range.
Before the effective filing date of the claimed invention, one of ordinary skill in the art would have found it obvious to modify the invention described in the rejection of claim 34 above under the teachings of Yaras, to form the peripheral surface features as binary grating at the disclosed pitches and duty cycles, using duty cycle selection methods known in the art and machining techniques familiar to a skilled artisan. Predictably, this would result in a device where the fill factor of the peripheral band is tuned to the signal extraction efficiency.
Regarding claim 47:
Li in view of Yaras, and further in view of Miller teaches the display system of claim 34, wherein:
the plurality of surface features (Figure 22A, outcoupling elements 2220) extends out, on one or both of the top and bottom major surfaces (Figure 22A, the area of gratings 2210a extending on both surfaces 2201 and 2203) no more than 2 mm from the edge (paragraph 251 states this explicitly).
Regarding claim 48:
Li in view of Yaras, and further in view of Miller teaches the display system of Claim 34.
Li does not teach the 1.8 mm limit as claimed.
Miller teaches a plurality of surface features (edge pattern 202) extends out, on one or both of the top and bottom major surfaces, no more than 1.8 mm from the edge (Figure 2A-2D, edge pattern 202 extending from ten microns to as far as five millimeters from the edge, encompassing the claimed value, Figure 4C).
Insofar as the limit of 1.8 mm precedes the end of the range, optimizing a known range is well understood in the art. The distance from the edge is a results effective variable which controls the absorption of propagating light that reaches the waveguide edge.
Before the effective filing date of the claimed invention, one of ordinary skill in the art would have found it obvious to modify the invention described in the rejection of claim 34 above under the teachings of Miller to ensure that the surface features extend no more than 1.8 mm from the edge. This may be accomplished using machining and placement techniques known in the art for surface profiles known in the art, and would predictably result in a device which remains compact while provided the optical guidance to operate the device efficiently.
Regarding claim 49:
Li in view of Yaras, and further in view of Miller teaches the display system of Claim 34.
Li does not teach the 1.6 mm limit as claimed.
Miller teaches a plurality of surface features (edge pattern 202) extends out, on one or both of the top and bottom major surfaces, no more than 1.8 mm from the edge (Figure 2A-2D, edge pattern 202 extending from ten microns to as far as five millimeters from the edge, encompassing the claimed value, Figure 4C).
Insofar as the limit of 1.6 mm precedes the end of the cited range, optimizing a known range is well understood in the art. The distance from the edge is a results effective variable which controls the absorption of propagating light that reaches the waveguide edge.
Before the effective filing date of the claimed invention, one of ordinary skill in the art would have found it obvious to modify the invention described in the rejection of claim 34 above under the teachings of Miller to ensure that the surface features extend no more than 1.6 mm from the edge. This may be accomplished using machining and placement techniques known in the art for surface profiles known in the art, and would predictably result in a device which remains compact while provided the optical guidance to operate the device efficiently.
Regarding claim 50:
Li in view of Yaras, and further in view of Miller teaches the display system of Claim 34.
Li does not teach the 0.2 mm limit as claimed.
Miller teaches a plurality of surface features (edge pattern 202) extends out, on one or both of the top and bottom major surfaces, no more than 0.2 mm from the edge (Figure 2A-2D, edge pattern 202 extending from ten microns to as far as five millimeters from the edge, encompassing the claimed value, Figure 4C).
Insofar as the limit of 0.2 mm precedes the end of the cited range, optimizing a known range is well understood in the art. The distance from the edge is a results effective variable which controls the absorption of propagating light that reaches the waveguide edge.
Before the effective filing date of the claimed invention, one of ordinary skill in the art would have found it obvious to modify the invention described in the rejection of claim 34 above under the teachings of Miller to ensure that the surface features extend no more than 0.2 mm from the edge. This may be accomplished using machining and placement techniques known in the art for surface profiles known in the art, and would predictably result in a device which remains compact while provided the optical guidance to operate the device efficiently.
Regarding claim 51:
Li in view of Yaras, and further in view of Miller teaches the display system of Claim 34.
Li does not teach the 0.1 mm limit as claimed.
Miller teaches a plurality of surface features (edge pattern 202) extends out, on one or both of the top and bottom major surfaces, no more than 0.1 mm from the edge (Figure 2A-2D, edge pattern 202 extending from ten microns to as far as five millimeters from the edge, encompassing the claimed value, Figure 4C).
Insofar as the limit of 0.1 mm precedes the end of the cited range, optimizing a known range is well understood in the art. The distance from the edge is a results effective variable which controls the absorption of propagating light that reaches the waveguide edge.
Before the effective filing date of the claimed invention, one of ordinary skill in the art would have found it obvious to modify the invention described in the rejection of claim 34 above under the teachings of Miller to ensure that the surface features extend no more than 0.1 mm from the edge. This may be accomplished using machining and placement techniques known in the art for surface profiles known in the art, and would predictably result in a device which remains compact while provided the optical guidance to operate the device efficiently.
Regarding claim 52:
Li in view of Yaras, and further in view of Miller teaches the display system of Claim 34.
Li does not teach the 0.05 mm limit as claimed.
Miller teaches a plurality of surface features (edge pattern 202) extends out, on one or both of the top and bottom major surfaces, no more than 0.05 mm from the edge (Figure 2A-2D, edge pattern 202 extending from ten microns to as far as five millimeters from the edge, encompassing the claimed value, Figure 4C).
Insofar as the limit of 0.05 mm precedes the end of the cited range, optimizing a known range is well understood in the art. The distance from the edge is a results effective variable which controls the absorption of propagating light that reaches the waveguide edge.
Before the effective filing date of the claimed invention, one of ordinary skill in the art would have found it obvious to modify the invention described in the rejection of claim 34 above under the teachings of Miller to ensure that the surface features extend no more than 0.05 mm from the edge. This may be accomplished using machining and placement techniques known in the art for surface profiles known in the art, and would predictably result in a device which remains compact while provided the optical guidance to operate the device efficiently.
Regarding claim 53:
Li in view of Yaras, and further in view of Miller teaches the display system of Claim 34
further comprising a light absorbing material (Figure 22A, light absorbing material 2204 disposed on the edge (edge 2205) and one or more of the plurality of surface features (outcoupling elements 2220).
Regarding claim 54:
Li in view of Yaras, and further in view of Miller teaches the display system of Claim 34
Wherein the light absorbing material (Figure 22A, material 2204) covers an area beyond portions of the top and bottom major surfaces (2201 and 2203) having the plurality of surface features (Gratings 2210).
Regarding claim 55:
Li in view of Yaras, and further in view of Miller teaches the display system of Claim 34
Wherein a plurality of surface features are not covered by dark material (Figure 22A, outcoupling elements 2220 occupy the area of gratings 2210a and in embodiment in which “the light absorbing materials 2204 may be omitted,” paragraph 250).
Regarding claim 56:
Li in view of Yaras, and further in view of Miller teaches the display system of Claim 34
wherein said plurality of surface features are not covered by black or grey material (paragraph 250, “in some embodiments, the light absorbing material 2204 may be omitted”), meaning that the material properties are not those that enable light absorption. This is most simply understood as a dark material.
Regarding claim 57:
Li in view of Yaras, and further in view of Miller teaches the display system of Claim 34
wherein said plurality of surface features are not covered by opaque material (the outcoupling elements 2220 are covered by no material, as the light absorbing material is “omitted” – therefore, it is not covered by an opaque material).
Regarding claim 58:
Li in view of Yaras, and further in view of Miller teaches the display system of Claim 34
Wherein the waveguide is part of a stack of waveguides (Figures 24 and 9A-9C, waveguides 2202a and 2202b form a waveguide stack 600).
Regarding claim 59:
Li in view of Yaras, and further in view of Miller teaches the display system of Claim 34
Wherein the eyepiece is disposed on a frame configured to be supported on the head or face of the user (Figure 9D, display 70 is coupled to frame 80 which is wearable by user 90 and configured to position the display in front of the eyes of the user).
Regarding claim 60:
Li in view of Yaras, and further in view of Miller teaches the display system of Claim 34
Wherein the eyepiece forms part of eyewear configured to be worn by the user (Figure 9D, display 70 coupled to frame 80, the display being expressly stated as capable of being considered eyewear).
Regarding claim 61:
Li in view of Yaras, and further in view of Miller teaches the display system of Claim 34.
Li does not expressly teach wherein the eyepiece is transparent such that the user can see through the eyepiece to view the environment in front of the user and the eyepiece as claimed, though a transparent eyepiece is an obvious and common choice in the art.
Yaras teaches a waveguide eyepiece for an augmented reality display (Title, Abstract), comprising:
Wherein the eyepiece is transparent such that the user can see through the eyepiece to view the environment in front of the user and the eyepiece (Figure 2, Figure 3A-3C, primary planar waveguide 108 is at least partially transparent so as to allow viewers to see the real world through the waveguide and also to view digital imagery simultaneously).
Before the effective filing date of the claimed invention, one of ordinary skill in the art would have found it obvious to modify the invention described in the rejection of claim 34 above under the teachings of Yaras, to form the eyepiece of optically transmissive material using a transparent substrate selection known in the art. Predictably, this would result in a device where virtual content is overlaid on a user’s direct view of the surrounding environment.
Regarding claim 68:
Li in view of Yaras, and further in view of Miller teaches the display system of Claim 34.
Li does not teach the pitch as claimed.
Miller teaches that one of the configurable parameters comprises the pitch (Figure 8, pitches 810 and 815) of the plurality of surface features (grating structures 820 and 825 across edge portion 802).
Before the effective filing date of the claimed invention, one of ordinary skill in the art would have found it obvious to modify the invention described in the rejection of claim 34 above under the teachings of Miller to have the surface feature parameters include pitch. This may be accomplished using graded pitch patterning methods and routine design oversight known to a skilled artisan. This would predictably result in a device where the wavelength out-coupled at each position along the band is set by the pitch at that position, so that the band as a whole extracts stray light across a range of wavelengths rather than a single one.
Regarding claim 69:
Li in view of Yaras, and further in view of Miller teaches the display system of Claim 34
Li does not teach the peak to peak spacing parameter as taught.
Miller teaches an eyepiece waveguide having an edge grating pattern proximal to a simulated edge (as described in the rejection of claim 34 above), wherein:
Said one or more parameters comprises peak-to-peak spacing (Figure 8, pitches 810 and 815 have a peak to peak spacing) of the surface features (surface grating structures 820 and 825 across the edge portion 802, the spacing being wider at 815 and narrower at 810 near the functional area, thereby denoting a varying parameter: the peak to peak spacing).
Before the effective filing date of the claimed invention, one of ordinary skill in the art would have found it obvious to modify the invention described in the rejection of claim 34 above under the teachings of Miller and Yaras, to make peak to peak spacing of the peripheral surface features the parameter the changes with distance from the edge, using graded-pitch grating patterning known in the art. Predictable, this would result in a device where the grating period at each position along the peripheral band is set by the spacing between adjacent features at that position.
Claim(s) 39, 44, 66, and 67 is/are rejected under 35 U.S.C. 103 as being unpatentable over Li (US 2020/0400941 A1) in view of Yaras (US 2019/0094551 A1), and further in view of Miller (US 2019/0170932 A1) and Huang (US 10598938 B1).
Regarding claim 39:
Li in view of Yaras, and further in view of Miller teaches the display system of Claim 34.
Li does not teach the sloping surfaces as claimed.
Huang teaches slanted surface-relief grating couplers for a waveguide display (Abstract, Title), wherein:
At least one of said surface features has two sloping surfaces (Figure 9, ridges 922 are surface features inclined at a slant angle relative to the substrate, whereby both sidewalls bounding gaps 924 are inclines rather than perpendicular to the major surface).
Before the effective filing date of the claimed invention, one of ordinary skill in the art would have found it obvious to modify the invention described in the rejection of claim 34 above under the teachings of Huang to form the peripheral surface features with inclined sidewalls on both sides of each features, using slanted etch or slanted imprint patterning known in the art. Predictably, this would result in a device where the feature presents an inclined rather than a perpendicular sidewall, increasing the diffraction efficiency relative to a binary sidewall profile.
Regarding claim 66:
Li in view of Yaras, and further in view of Miller teaches the display system of Claim 34.
Li does not teach the sloping surfaces as claimed.
Huang teaches slanted surface relief gratings having regions of differing angular selectivity.
Said surface features (ridges 922 of slanted grating coupler 920, Figure 9) have a surface oriented at an angle (slant angle ξ) and said one or more parameters comprises the angle of orientation of said surface (Figures 7A-7C, output grating couplers 714, 715, 718 have different configurations, including different slant profiles).
Before the effective filing date of the claimed invention, one of ordinary skill in the art would have found it obvious to modify the invention described in the rejection of claim 34 above under the teachings of Huang, to vary the slant angle of the peripheral surface features by position within the band, using region wise slanted grating patterning known in the art. Predictably, this would result in a device where each portion of the peripheral band is matched to the incidence angles of the light reaching it, increasing the fraction of stray light extracted.
Regarding claim 67:
Li in view of Yaras, and further in view of Miller and Huang teaches the display system of Claim 66.
Li does not teach the surface features being angled as claimed.
Huang teaches angled surface features (see rejection of claim 66 above), wherein:
said surface features have a surface oriented at an angle and said one or more parameters comprises the angle of orientation of said surface. (Figures 7A-7C, output grating couplers 714, 716, 718 have slant angle configurations, the angle denoted by ξ).
Before the effective filing date of the claimed invention, one of ordinary skill in the art would have found it obvious to modify the invention described in the rejection of claim 66 above under the teachings of Huang to ensure that the inclination of each feature surface according to the propagation angle of the light first meeting that feature so that the differing distances from the edge are inclined differently, is accomplished using region-wise slanted grating patterning methods known in the art. Predictably this would result in a device where a greater fraction of the angular distribution of stray light is extracted across the band than with a single uniform inclination.
Claim(s) 44 and 70 is/are rejected under 35 U.S.C. 103 as being unpatentable over Li (US 2020/0400941 A1) in view of Yaras (US 2019/0094551 A1), and further in view of Miller (US 2019/0170932 A1) and Keech (US 20190114484 A1).
Regarding claim 44:
Li in view of Yaras, and further in view of Miller teaches the display system of Claim 34.
Li does not teach the surface feature height range as claimed.
Keech teaches an input and output grating formed in a waveguide structure for an AR system (Title, Abstract), wherein:
The plurality of surface features (grating elements 32, Figure 1, Figure 2, and as described in paragraph 55) have an average height in a range from 10 to 500 nm (paragraph 55 explicitly defines a range from 50 to 500 nm).
While Keech does not explicitly teach the portion of the range from 10 to 50 nm, the range in the prior art found in the claimed range meets the limitation.
Before the effective filing date of the claimed invention, one of ordinary skill in the art would have found it obvious to modify the invention described in the rejection of claim 34, under the teachings of Keech to have a surface feature height that is in the range of 50-500 nm, which falls within the 10 nm to 500 nm range as claimed. This may be accomplished using methods, peripheral surface feature design methods, and surface grating depth selection techniques known in the art. Predictably, this would result in a device where diffraction efficiency at the peripheral band is sufficient to extract stray light within the available interaction length.
Regarding claim 70:
Li in view of Yaras, and further in view of Miller teaches the display system of Claim 34.
Li does not teach the height parameter as claimed for surface features as claimed.
Keech teaches input/output gratings in a waveguide structure for AR systems, wherein
said one or more parameters comprises the height of the surface features. (Figure 1, Figure 2, the grating height h of the input and output grating being constant so as to vary the rate at which light is coupled in and out of the grating).
Before the effective filing date of the claimed invention, one of ordinary skill in the art would have found it obvious to modify the invention described in the rejection of claim 34 above under the teachings of Keech to vary the height of the peripheral surface features as a function of position within the band, using imprint patterning techniques known in the art. Predictably, this would result in a device where the extraction rate along the peripheral band is controlled as that stray light is removed progressively rather than all at one location.
Conclusion
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/PREET B PATEL/Examiner, Art Unit 2874
/THOMAS A HOLLWEG/Supervisory Patent Examiner, Art Unit 2874
