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 .
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 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.
Continued Examination Under 37 CFR 1.114
A request for continued examination under 37 CFR 1.114, including the fee set forth in 37 CFR 1.17(e), was filed in this application after allowance or after an Office action under Ex Parte Quayle, 25 USPQ 74, 453 O.G. 213 (Comm'r Pat. 1935). Since this application is eligible for continued examination under 37 CFR 1.114, and the fee set forth in 37 CFR 1.17(e) has been timely paid, prosecution in this application has been reopened pursuant to 37 CFR 1.114. Applicant's submission filed on 5/25/2026 has been entered.
Disposition of the Claims
Claims 1-3, 5-9, 11-22 are pending.
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 of this title, 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.
The factual inquiries set forth in Graham v. John Deere Co., 383 U.S. 1, 148 USPQ 459 (1966), that are applied for establishing a background for determining obviousness under 35 U.S.C. 103 are summarized as follows:
1. Determining the scope and contents of the prior art.
2. Ascertaining the differences between the prior art and the claims at issue.
3. Resolving the level of ordinary skill in the pertinent art.
4. Considering objective evidence present in the application indicating obviousness or nonobviousness.
This application currently names joint inventors. In considering patentability of the claims the examiner presumes that the subject matter of the various claims was commonly owned as of the effective filing date of the claimed invention(s) absent any evidence to the contrary. Applicant is advised of the obligation under 37 CFR 1.56 to point out the inventor and effective filing dates of each claim that was not commonly owned as of the effective filing date of the later invention in order for the examiner to consider the applicability of 35 U.S.C. 102(b)(2)(C) for any potential 35 U.S.C. 102(a)(2) prior art against the later invention.
Claims 1-3, 5-9, and 11-15 are rejected under 35 U.S.C. 103 as being unpatentable over Vuzix ‘630 (US 20200209630 A1, of record) in view of Grey (US 20190004321 A1, of record) and Levola (WO 2008081070 A1, newly cited), further in view of Alexeev (US 12339460 B2, effectively filed 3/19/2019, newly cited).
Regarding claim 1, Vuzix ‘630 teaches an image light guide for conveying a virtual image (para [0056], the image-bearing light WI from a real, virtual or hybrid image source (not shown) into the substrate S of the planar waveguide 22), comprising:
a substrate operable to propagate image-bearing light beams along a length thereof (para [0056], the image-bearing light Wi from a real, virtual or hybrid image source (not shown) into the substrate S of the planar waveguide 22. . . propagation along the planar waveguide 22 by Total Internal Reflection (TIR));
an in-coupling diffractive optic formed along said substrate, wherein said in-coupling diffractive optic is operable to diffract at least a portion of said image-bearing light beams from an image source into said substrate in an angularly encoded form (para [0056], in-coupling diffractive optic IDO couples the image-bearing light WI from a real, virtual or hybrid image source (not shown) into the substrate S of the planar waveguide 22. . . diffracted into a generally more condensed range of angularly related beams in keeping with the boundaries set by TIR, the image-bearing light WG preserves the image information in an encoded form); and
an out-coupling diffractive optic formed along a first side of said substrate (para [0055]]), wherein said outcoupling diffractive optic is at least partially located in a plane having an xaxis and a y-axis, and is operable to diffract a portion of said image-bearing light beams from said substrate in an angularly decoded form (para [0056], {0106], An out-coupling diffractive optic ODO receives the encoded image-bearing light WG and diffracts (also generally through a first diffraction order) the image-bearing light WG out of the planar waveguide 22 as the image-bearing light WO toward the intended location of a viewer's eye. . . a second interaction with an equivalently pitched pattern (in x and y dimensions) effectively unencodes the outcoupled beam portions);
wherein said out-coupling diffractive optic comprises a first plurality of periodic structures and a second plurality of periodic structures, said first and second pluralities of periodic structures operable to diffract a portion of said imagebearing light beams into diffractive orders (para [0056], [0058], (0067), [0088], An out-coupling diffractive optic ODO receives the encoded image-bearing light WG and diffracts (also generally through a first diffraction order) . . . Grating vectors, such as the depicted grating vectors kO, k1, and k2, extend in a direction that is normal to the diffractive features (e.g., grooves, lines, or rulings). . .out-coupling diffractive optic ODO as a diffractive array 100. Array 100 has multiple component diffractive optical elements or optics 102. In a row of the array 100, sequential diffractive optical elements 102 have alternating grating vectors k2 and k3. . . period d1 of the first diffraction grating is different from the period d2 of the second diffraction grating), wherein said first and second pluralities of periodic structures comprise a plurality of vertices (e.g. Fig. 13C, para [0087]),
Vuzix ‘630 does not explicitly show wherein each adjacent vertex along said x-axis is offset in said y-axis direction, or where one of said first plurality of periodic structures and one of said second plurality of second plurality of periodic structures intersect or overlap.
In another embodiment, Vuzix ‘630 explicitly shows a plurality of overlapped linear gratings (Figs. 14 and 15). Grey drawn to augmented reality display devices having waveguides with gratings explicitly shows that crossed, i.e. intersecting or overlapping, gratings are conventional (¶28, “An alternative system is disclosed in WO 2008/081070 … A crossed grating 10 is also provided between the first and third gratings 4, 8. The crossed grating 10 includes two overlapping gratings with grooves at 90° to one another. When light from the input grating 4 encounters the crossed grating 10 it is simultaneously diffracted in opposite directions which are mutually orthogonal to the input light beam, but are within the plane of the waveguide 2”). As cited by Grey, Levola further details that the gratings are linear diffractive features (p. 11, C. 34, “The input grating 10 comprises substantially parallel and substantially linear diffractive features 11 having a grating period d.sub.0- The diffractive features 11 are substantially parallel to the direction SZ. The output grating 30 comprises substantially linear diffractive features 31”).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have implemented offset grating vectors known from Vuzix ‘630 using crossed linear gratings known in the art to be functional for multiple direction diffraction as disclosed by Grey and Levola and thus obtained a predictable diffraction result.
Grey and Levola do not remedy Vuzix ‘630’s silence concerning wherein each adjacent vertex along said x-axis is offset in said y-axis direction.
However, Alexeev drawn to augmented or virtual reality devices explicitly shows intersecting linear diffractive features at +/- 30 degree angles (Fig. 5 and C. 7, ll. 10-32), and offset vertices (Fig. 12d)
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have varied the angle of the linear diffractive features of the modified Vuzix ‘620 according to the teachings of Alexeev for the purpose of improving angular uniformity of colors and improved diffraction efficiency of the disclosed geometry (Alexeev, C. 7, ll. 33-46).
Regarding claim 2, the modified Vuzix ‘630 teaches an image light guide for conveying image bearing light according to claim 1, wherein: said in-coupling diffractive optic defines a first grating vector (para [0058], the in-coupling diffractive optic IDO is oriented to diffract the image-bearing light WG about a grating vector kO); and
said out-coupling diffractive optic defines a second grating vector and a third grating vector (para [0068], Diffractive array 100, used in the light path as out-coupling diffractive optic in FIG. 4 and subsequent embodiments, can be considered structurally formed as the union of disjoint, mutually non-overlapping subsets of diffractive elements. . .diffractive elements 102, elements of at least two subsets alternate with each other, so that each element from the subset with grating vector k2 is immediately adjacent to one or more neighboring elements from the other subset with grating vector k3).
Regarding claim 3, the modified Vuzix ‘630 teaches the image light guide for conveying image bearing light according to claim 2, wherein said second grating vector is arranged at a first angle relative to said first grating vector, and said third grating vector is arranged at a second angle relative to said first grating vector (para [0060], (0075), the in-coupling and out-coupling diffractive optics IDO and ODO, the three grating vectors k0, k1, and k2 (as directed line segments) form an equilateral triangle. . .diffractive elements 102 are of either a first subset having a grating vector that is offset from the grating vector of the IDO by about +60 degrees (that is, offset by an angle within +60+/-3 degrees)).
Regarding claim 5, the modified Vuzix ‘630 teaches the image light guide for conveying image bearing light according to claim 1, wherein a center ray of said image-bearing light beams from said image source is disposed at a first angle relative to said x-y plane and a second angle within said x-y plane relative to said in-coupling diffractive optic (para [0078], [0090], figure 8A, light handling behavior for light traveling at different angles within the image light guide 170. . .a right-handed coordinate system can be centered on the intersection point of the input ray vector with the plane of the grating, such that the grating’s normal vector is along the z-axis, the x-axis is along the input ray's vector projected onto the xy-plane).
Regarding claim 6, the modified Vuzix ‘630 teaches an image light guide for conveying image bearing light according to claim 1, wherein: said out-coupling diffractive optic is operable to diffract a portion of a first portion of each of said image-bearing light beams in a first direction via incidence with said first plurality of periodic structures, whereby said first portion of each of said image-bearing light beams is expanded in a first dimension (para [0058}, [0105], [(0107}, Grating vectors, such as the depicted grating vectors k0, k1, and k2, extend ina direction that is normal to the diffractive features (e.g., grooves, lines, or rulings) of the diffractive optics. . .portions of the image-bearing beams are diffracted out of the waveguide as depicted by the circle 728 primarily based on an encounter with the grating pattern defined by the k1 vector like a conventional out-coupling diffractive optic. .. The image-bearing beams are expanded by successions diffractive encounters with the out-coupling diffractive optic, each encounter diffracting the image-bearing beams through different diffractive orders), and said out-coupling diffractive optic is operable to diffract a portion of a second portion of each of said image-bearing light beams in a second direction via incidence with one or more of said second plurality of periodic structures, whereby said second portion of each of said image-bearing light beams is expanded in a second dimension (para [0058], [0105], [0110], Grating vectors, such as the depicted grating vectors k0, k1, and k2, extend in a direction that is normal to the diffractive features (e.g., grooves, lines, or rulings) of the diffractive optics. . portions of the image-bearing beams are diffracted out of the waveguide as depicted by the circle 728 primarily based on an encounter with the grating pattern defined by the k1 vector like a conventional out-coupling diffractive optic ... The additional first order diffractions 718 and 720 diffract portions of the image-bearing beam in different directions that are inclined to the nominal direction of propagation as projected onto the x-y plane of the waveguide. Each encounter being subject to the additional first order diffractions spreads portions of the image-bearing beam in transverse directions throughout the waveguide).
Regarding claim 7, the modified Vuzix ‘630 teaches the image light guide for conveying image bearing light according to claim 6, wherein: said out-coupling diffractive optic is operable to diffract a portion of said first portion of each of said image-bearing light beams expanded in said first dimension out of said substrate via incidence with said second plurality of periodic structures (para [0056], [0080], the out- coupling diffractive optic ODO is arranged to encounter the image-bearing light WG multiple times and to diffract only a portion of the image-bearing light WG on each encounter. . .Light from in-coupling diffractive optic IDO is directed to first and second distribution gratings 70 for expansion with respect to the y dimension shown. The resulting light is then redirected into out-coupling diffractive optic ODO by paired distribution gratings 72. Out-coupling diffractive optic ODO uses diffractive array 100 as described previously. FIG. 9B shows representative grating vectors for the different diffractive components of the image light guide 160), and said out-coupling diffractive optic is operable to diffract a portion of said second portion of each of said image-bearing light beams expanded in said second dimension out of said substrate via incidence with said first plurality of periodic structures (para [0056], [0080], the out-coupling diffractive optic ODO is arranged to encounter the image-bearing light WG multiple times and to diffract only a portion of the image-bearing light WG on each encounter. . .Light from in-coupling diffractive optic IDO is directed to first and second distribution gratings 70 for expansion with respect to the y dimension shown. The resulting light is then redirected into out-coupling diffractive optic ODO by paired distribution gratings 72. Out-coupling diffractive optic ODO uses diffractive array 100 as described previously. FIG. 9B shows representative grating vectors for the different diffractive components of the image light guide 160).
Regarding claim 8, the modified Vuzix ‘630 teaches the image light guide for conveying image bearing light according to claim 1, wherein said first and ‘second pluralities of periodic structures comprise overlapped parallel straight line diffractive features (para [0097], illustrated in figure 16, FIG. 16 is a schematic showing the three diffraction grating patterns 610, 612, 614 of FIG. 15 overlapping one another. From the overlapping patterns, a region 650 is selected as the final diffraction pattern of a compound diffraction grating).
Regarding claim 9, the modified Vuzix ‘630 teaches the image light guide for conveying image bearing light according to claim 8, and further discloses wherein said in-coupling diffractive optic comprises a plurality of parallel straight line linear diffractive features (p. 11, ll. 34), said first plurality of periodic structures are oriented at a first angle relative to said plurality of parallel straight line linear diffractive features of said in-coupling diffractive optic (see Fig. 5a), and said second plurality of periodic structures are oriented at a second angle relative to said plurality of parallel straight line linear diffractive features of said in-coupling diffractive optic (see Fig. 5a).
The modified Vuzix ‘620 does not explicitly show wherein said first angle is greater than said second angle.
Alexeev drawn to augmented or virtual reality devices explicitly shows intersecting linear diffractive features at +/- 30 degree angles (Fig. 5 and C. 7, ll. 10-32).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have varied the angle of the linear diffractive features of the modified Vuzix ‘620 according to the teachings of Alexeev for the purpose of improving angular uniformity of colors and improved diffraction efficiency of the disclosed geometry (Alexeev, C. 7, ll. 33-46).
Regarding claim 11, the modified Vuzix ‘630 teaches the image light guide for conveying image bearing light according to claim 1, wherein said out- coupling diffractive optic comprises a plurality of unit cells, each said unit cell defining an irregular hexagon (para [0010], {0099], The unit cells can be in the shape of polygons such as rectangles or hexagons for providing orderly relationships among the diffraction patterns, including relative orientation and pitch. . . The remaining regions contain hexagonal grating features 654. Here, the grating patterns are formed by the arrangements of the grating features themselves based on the replication of unit cells into a two-dimensional lattice).
Regarding claim 12, the modified Vuzix ‘630 teaches the image light guide for conveying image bearing light according to claim 11, but does not explicitly show wherein a height of each unit cell is a multiple of said offset of said vertices.
However, 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 fields of diffraction and photonics, it is exceptionally well known that optical dimensions of the employed structure are results effective with respect to the incident light’s wavelength and angle. It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have optimized the size of the unit cells of the modified Vuzix ‘630 toward achieving improved angular uniformity of colors and improved diffraction efficiency of the disclosed geometry, thus achieving the claimed dimensional relationship.
Regarding claim 13, the modified Vuzix ‘630 teaches the image light guide for conveying image bearing light according to claim 1, wherein said first and second pluralities of periodic structures comprise portions of line structures (para [0058], [0097], Grating vectors, such as the depicted grating vectors k0, k1, and k2, extend in a direction that is normal to the diffractive features (e.g., grooves, lines, or rulings) of the diffractive optics and have a magnitude inverse to the period or pitch d. . . FIG. 16 is a schematic showing the three diffraction grating patterns 610, 612, 614 of FIG. 15 overlapping one another). See also the above cited portions of Grey and Levola.
Regarding claim 14, the modified Vuzix ‘630 teaches the image light guide for conveying image bearing light according to claim 1, wherein said out-coupling diffractive optic is formed of a volume holographic material (para [0123], The in-coupling and out-coupling diffractive optics IDO and ODO can be, but are not limited to, diffraction gratings or formed as volume holograms, or formed from a holographic polymer dispersed liquid crystal).
Regarding claim 15, the modified Vuzix ‘630 teaches the image light guide for conveying image bearing tight according to claim 1, wherein said first and second pluralities of periodic structures define triangular area domains (para [0075], FIG. 7C shows an enlarged portion of an arrangement using triangles. For each of these arrangements, the diffractive elements 102 are of either a first subset having a grating vector that is offset from the grating vector of the IDO by about +60 degrees (that is, offset by an angle within +60+/-3 degrees), or a second subset having a grating vector that is offset from the grating vector of the IDO by about -60 degrees (that is, offset by an angle within -60+/-3 degrees); see also Fig. 14, overlapping gratings forming triangle domains).
Claims 4, 9, and 16 are rejected under 35 U.S.C. 103 as being unpatentable over Vuzix ‘630 as applied to claim 2 and 8 and 15 above, and further in view of Vuzix ‘788 (WO 2020/009788 A1, of record).
Regarding claim 4, Vuzix ‘630 teaches the image light guide for conveying image bearing light according to claim 2, wherein said first, second, and third grating vectors create a triangle (para [0095], Basing the grating vector magnitudes on a common pitch, the three grating vectors k1, k2, and k3 (as directed line segments) form an equilateral triangle and sum to a zero magnitude).
Vuzix ‘630 does not teach the triangle is a scalene triangle.
However Vuzix ‘788 teaches a scalene triangle (para [0070], a representation of the diffraction grating vectors kin, kT, and kout forming, in general, a scalene triangle. In FIG. 5B, angle alpha IN is the angle between the in-coupling grating vector kT and the out-coupling grating vector kout).
It would have been obvious to a person having ordinary skill in the art to use the scalene triangle of Vuzix ‘788 in the light guide of Vuzix ‘630, because the disclosure of Vuzix ‘788 would have reduced sensitivities of alignment (para [0012], The new design possibilities also accommodate desired expansions of the eyebox in two dimensions to reduce sensitivities for aligning the eyebox with a viewer's eye and can also support the conveyance of a wide range of angularly).
Regarding claim 9, Vuzix ‘630 teaches the image light guide for conveying image bearing light according to claim 8, wherein said in- coupling diffractive optic comprises a plurality of parallel straight line diffractive features (para [0067], [0075], [0102], illustrated in figure 5, Grating vectors k2 are offset from input grating vector k and from axis x by +60 degrees (alternately, offset from axis y by -30 degrees). Grating vectors k3 are offset from input grating vector k and axis x by -60 degrees. . For each of these arrangements, the diffractive elements 102 are of either a first subset having a grating vector that is offset from the grating vector of the IDO by about +60 degrees (that is, offset by an angle within +60+/-3 degrees), or a second subset having a grating vector that is offset from the grating vector of the IDO by about -60 degrees (that is, offset by an angle within -60+/-3 degrees).. .Considered as grating lines, the individual grating lines associated with the k1 grating vector extend discontinuously along the y coordinate axis whereas the individual grating lines associated with the k2 grating vector extend more continuously along the x coordinate axis), said first plurality of periodic structures are oriented at a first angle relative to said plurality of parallel straight line diffractive features of said in-coupling diffractive optic (para [0075}, (0102), illustrated in figure 5, For each of these arrangements, the diffractive elements 102 are of either a first subset having a grating vector that is offset from the grating vector of the !DO by about +60 degrees (that is, offset by an angle within +60+/-3 degrees), or a second subset having a grating vector that is offset from the grating vector of the IDO by about -60 degrees (that is, offset by an angle within -60+/-3 degrees).. .Considered as grating lines, the individual grating lines associated with the k1 grating vector extend discontinuously along the y coordinate axis whereas the individual grating lines associated with the k2 grating vector extend more continuously along the x coordinate axis), and said second plurality of periodic structures are oriented at a second angle relative to said plurality of parallel straight line diffractive features of said in-coupling diffractive optic (para (0075), [0102], illustrated in figure 5, For each of these arrangements, the diffractive elements 102 are of either a first subset having a grating vector that is offset from the grating vector of the IDO by about +60 degrees (that is, offset by an angle within +60+/-3 degrees), or a second subset having a grating vector that is offset from the grating vector of the IDO by about -60 degrees (that is, offset by an angle within -60+/-3 degrees).. Considered as grating lines, the individual grating lines associated with the k1 grating vector extend discontinuously along the y coordinate axis whereas the individual grating lines associated with the k2 grating vector extend more continuously along the x coordinate axis).
Vuzix ‘630 does not teach wherein said first angle is greater than said second angle.
However Vuzix ‘788 teaches a first angle is greater than said second angle (para [0070], In FIG. 5B, angle alpha IN is the angle between the in-coupling grating vector kT and the out-couping grating vector kout, and alpha T is the angle between the turning optic grating vector kT and the out-coupling grating vector kout).
It would have been obvious to a person having ordinary skill in the art to use the first angle is greater than said second angle of Vuzix ‘630, because the disclosure of Vuzix ‘788 would have reduced sensitivities of alignment (para (0012), The new design possibilities also accommodate desired expansions of the eyebox in two dimensions to reduce sensitivities for aligning the eyebox with a viewer's eye and can also support the conveyance of a wide range of angularly).
Regarding claim 16, Vuzix ‘630 teaches the image light guide for conveying image bearing light according to claim 15. Vuzix ‘630 does not teach wherein said area domains comprise scalene triangles, whereby said image-bearing light beams incoming from an image source at a non-normal angle to said in-coupling diffractive optic are diffracted.
However Vuzix ‘688 teaches said area domains comprise scalene triangles, whereby said image-bearing light beams incoming from an image source at a non-normal angle to said in-coupling diffractive optic are diffracted (para [0070], [0075], In FIG. 5B, angle alpha IN is the angle between the in-coupling grating vector kT and the out- couping grating vector kout, and alpha T is the angle between the turning optic grating vector kT and the out-coupling grating vector. . . design freedoms remain including the chosen orientation of non-normal inputs to the image light guide, which can be used to optimize orientations of the waveguide to both the viewer and the image generator).
It would have been obvious to a person having ordinary skill in the art to use the area domains comprise scalene triangles, whereby said image-bearing light beams incoming from an image source at a non-normal angle to said in-coupling diffractive optic are diffracted of Vuzix ‘688 in the guide of Vuzix ‘630, because the disclosure of Vuzix ‘688 would have allowed optimization of orientations (para [0075], design freedoms remain including the chosen orientation of non- normal inputs to the image light guide, which can be used to optimize orientations of the waveguide to both the viewer and the image generator).
Claims 17 and 18 are rejected under 35 U.S.C. 103 as being unpatentable over Vuzix ‘630 in view of Ozarski (US 20010003035 A1, of record), further in view of Alexeev (US 12339460 B2, effectively filed 3/19/2019).
Regarding claim 17, Vuzix ‘630 teaches method of fabricating an image light guide for conveying image bearing light (para (0056), [0124], the image-bearing light WI from a real, virtual or hybrid image source (not shown) into the substrate S of the planar waveguide 22. . .after proper surface preparation of a glass substrate blank, the diffraction components can be formed on one or both outer surfaces of the image light guide using nano-imprinting methods, for example), comprising:
providing a substrate having a first surface (para [0056], the image-bearing light WI from a real, virtual or hybrid image source (not shown) into the substrate S of the planar waveguide 22. . . propagation along the planar waveguide 22 by Total Internal Reflection (TIR)), wherein a coating is coupled with said first surface (para [0013], [0122], multiple diffraction gratings can be stacked one over the other, each layer having a different grating vector orientation. . .2-D photonic crystals can be fabricated by photolithography, or by drilling holes in a suitable substrate. As is known to those skilled in the art, fabrication methods for 3-D photonic crystals include stacking multiple 2-D layers on top of each other, direct laser writing; layers understood as a coating);
providing a beam writing system operable to write in a first direction and a second direction, wherein said second direction is perpendicular to said first direction (para (0122], 2-D photonic crystals can be fabricated by photolithography, or by drilling holes in a suitable substrate ... fabrication methods for 3-D photonic crystals include stacking multiple 2-D layers on top of each other, direct laser writing); for a 2d pattern it is understood there must be two perpendicular directions);
providing a diffraction grating layout pattern comprising a plurality of unit cells (para [0010], The out-coupling diffractive optic can be formed as a diffraction lattice containing a plurality of unit cells in a plane defining a plurality of diffraction patterns in different orientations within the plane), each said unit cell comprising:
a first plurality of straight line diffractive features, and a second plurality of straight line diffractive features (see e.g. Figs. 14-16), wherein one or more intersections of said first and second pluralities of straight line diffractive features define one or more corresponding vertices (para [0095]-[0099], Basing the grating vector magnitudes on a common pitch, the three grating vectors k1, k2, and k3 (as directed line segments) form an equilateral triangle and sum to a zero magnitude. . . Either of the unit cells 666 or 668 can define the entire compound grating pattern 660 by contiguous replication of the respective unit cells with adjacent unit cells sharing vertices within the two-dimensional lattice);
locating said substrate in said beam writing system, whereby said beam writing system is operable to write into said coating (para [0122], the compound grating patterns can be formed as a 3-dimensional (3-D) photonic crystal. As is known to those skilled in the art, 2-D photonic crystals can be fabricated by photolithography, or by drilling holes in a suitable substrate. As is known to those skilled in the art, fabrication methods for 3-D photonic crystals include stacking multiple 2-D layers on top of each other, direct laser writing);
writing said diffraction grating layout pattern into said coating via said beam writing system (para [0122], 2-D photonic crystals can be fabricated by photolithography, or by drilling holes in a suitable substrate. As is known to those skilled in the art, fabrication methods for 3- D photonic crystals include stacking multiple 2-D layers on top of each other, direct laser writing).
Vuzix ‘630 does not teach wherein aligning one of said first and second pluralities of straight line diffractive features parallel with said beam writing system first direction, or wherein adjacent vertices along said first direction comprise an offset along said second direction.
Ozarski teaches aligning a plurality of straight line diffractive features parallel with a beam writing system first direction (para [0031]-{0033], In order to etch a diffraction grating with grooves whose facets are at a desired angle with respect to each other, a single crystal substrate must be carefully chosen . . Alignment marks (not shown) are etched into the substrate to determine precisely the crystallographic axes. . .The photoresist mask features 320 are formed by coating the substrate with a layer of photoresist; selectively exposing the photoresist through a photomask, using, for example, a contact printing technique or direct writing; developing the photoresist).
It would have been obvious to a person having ordinary skill in the art to use the aligning a plurality of straight line diffractive features parallel with a beam writing system first direction of Ozarski in the method of Vuzix ‘630, because the disclosure of Ozarski would have allowed precise control of a grating (para [0021], Precise control of the grating can be achieved by careful reticle fabrication, for which a variety of techniques exist including e-beam writing, optical beam writing, and ion beam writing).
Ozarski does not remedy Vuzix ‘630’s silence concerning wherein adjacent vertices along said first direction comprise an offset along said second direction.
However, Alexeev drawn to augmented or virtual reality devices explicitly shows intersecting linear diffractive features at +/- 30 degree angles (Fig. 5 and C. 7, ll. 10-32), and adjacent vertices along said first direction comprise an offset along said second direction (Fig. 12d)
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have varied the angle of the linear diffractive features of the modified Vuzix ‘620 according to the teachings of Alexeev for the purpose of improving angular uniformity of colors and improved diffraction efficiency of the disclosed geometry (Alexeev, C. 7, ll. 33-46).
Regarding claim 18, the modified Vuzix ‘630 teaches the method of fabricating an image light guide for conveying image bearing light according to claim 17, but does not explicitly show wherein a height of each unit cell is an integer multiple of said offset of said vertices.
However, 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 fields of diffraction and photonics, it is exceptionally well known that optical dimensions of the employed structure are results effective with respect to the incident light’s wavelength and angle. It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have optimized the size of the unit cells of the modified Vuzix ‘630 toward achieving improved angular uniformity of colors and improved diffraction efficiency of the disclosed geometry, thus achieving the claimed dimensional relationship.
Claim 19-22 are rejected under 35 U.S.C. 103 as being unpatentable over Vuzix ‘630 (US 20200209630 A1, of record) in view of Alexeev (US 12339460 B2, effectively filed 3/19/2019).
Regarding claim 19, Vuzix ‘630 teaches an image light guide (Figs. 4, 7C, 9, 10, 14-16) for conveying image bearing light, comprising:
a substrate operable to propagate image-bearing light beams along a length thereof (para [0056], the image-bearing light Wi from a real, virtual or hybrid image source (not shown) into the substrate S of the planar waveguide 22. . . propagation along the planar waveguide 22 by Total Internal Reflection (TIR));
an in-coupling diffractive optic formed along said substrate, wherein said in-coupling diffractive optic is operable to diffract a portion of said image-bearing light beams from an image source into said substrate in an angularly encoded form (para [0056], in-coupling diffractive optic IDO couples the image-bearing light WI from a real, virtual or hybrid image source (not shown) into the substrate S of the planar waveguide 22. . . diffracted into a generally more condensed range of angularly related beams in keeping with the boundaries set by TIR, the image-bearing light WG preserves the image information in an encoded form); and
an out-coupling diffractive optic formed along said substrate, wherein said outcoupling diffractive optic is at least partially located in a plane having an x-axis and a y-axis (e.g. Figs. 14 and 16 showing overlapping gratings in a plane; see para [0107] where the ODO is composed of overlapping gratings), and is operable to diffract a portion of said image-bearing light beams from said substrate in an angularly decoded form (para [0056], [0106], An out-coupling diffractive optic ODO receives the encoded image-bearing light WG and diffracts (also generally through a first diffraction order) the image-bearing light WG out of the planar waveguide 22 as the image-bearing light WO toward the intended location of a viewer's eye. . . a second interaction with an equivalently pitched pattern (in x and y dimensions) effectively unencodes the outcoupled beam portions);
wherein said out-coupling diffractive optic comprises a plurality of contiguous periodic structures defining sinusoidal rows operable to diffract a portion of said image-bearing light beams into diffractive orders (para [0103], FIGS. 20A, 20B, and 20C depict three alternative rectangular unit cells 710, 714, and 718 with differently shaped grating features 712, 716, 720. . . the rectangular unit cell 718 is closer to sinusoidal wave).
In a different embodiment, Vuzix ‘620 explicitly shows wherein said plurality of contiguous periodic structures comprise a plurality of vertices (see esp. Figs. 14 and 16),
Vuzix ‘620 does not explicitly show wherein each adjacent vertex along said x-axis is offset in said y-axis direction.
However, Alexeev drawn to augmented or virtual reality devices explicitly shows intersecting linear diffractive features at +/- 30 degree angles (Fig. 5 and C. 7, ll. 10-32), and offset vertices (Fig. 12d)
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have varied the angle of the linear diffractive features of the modified Vuzix ‘620 according to the teachings of Alexeev for the purpose of improving angular uniformity of colors and improved diffraction efficiency of the disclosed geometry (Alexeev, C. 7, ll. 33-46).
Regarding claim 20, the modified Vuzix ‘630 teaches the image light guide for conveying image bearing light according to claim 19, but does not explicitly show wherein a first sinusoidal row is out of phase with a second sinusoidal row of said out-coupling diffractive optic.
However, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention that implementing the vertex offset of Alexeev to the device of Vuzix ‘630 for the purpose of achieving improved angular uniformity of colors and improved diffraction efficiency of the disclosed geometry would displace the vertices of the disclosed sinusoidal gratings and thus necessarily result in a phase difference between them.
Regarding claim 21, Vuzix ‘630 teaches an image light guide (Figs. 4, 7C, 9, 10, 14-16) for conveying image bearing light, comprising:
a substrate operable to propagate image-bearing light beams along a length thereof (para [0056], the image-bearing light Wi from a real, virtual or hybrid image source (not shown) into the substrate S of the planar waveguide 22. . . propagation along the planar waveguide 22 by Total Internal Reflection (TIR));
an in-coupling diffractive optic formed along said substrate, wherein said in-coupling diffractive optic is operable to diffract at least a portion of said image-bearing light beams from an image source into said substrate in an angularly encoded form (para [0056], in-coupling diffractive optic IDO couples the image-bearing light WI from a real, virtual or hybrid image source (not shown) into the substrate S of the planar waveguide 22. . . diffracted into a generally more condensed range of angularly related beams in keeping with the boundaries set by TIR, the image-bearing light WG preserves the image information in an encoded form);
an out-coupling diffractive optic formed along a first side of said substrate, wherein said out-coupling diffractive optic is at least partially located in a plane having an x-axis and a y-axis (e.g. Figs. 14 and 16 showing overlapping gratings in a plane; see para [0107] where the ODO is composed of overlapping gratings), and is operable to diffract a portion of said image-bearing light beams from said substrate in an angularly decoded form (para [0056], [0106], An out-coupling diffractive optic ODO receives the encoded image-bearing light WG and diffracts (also generally through a first diffraction order) the image-bearing light WG out of the planar waveguide 22 as the image-bearing light WO toward the intended location of a viewer's eye. . . a second interaction with an equivalently pitched pattern (in x and y dimensions) effectively unencodes the outcoupled beam portions);
wherein said out-coupling diffractive optic comprises a plurality of unit cells arranged in a two-dimensional periodic lattice (e.g. Figs. 14 and 16), wherein each said unit cell repeats within said out-coupling diffractive optic to form a plurality of periodic structures (id., repeating by virtue of the overlapped periodicity), wherein said plurality of periodic structures is operable to diffract at least a portion of said image- bearing light beams into diffractive orders (sequitur), wherein said out-coupling diffractive optic comprises a plurality of vertices where two or more unit cells meet (Figs. 14).
Vuzix ‘620 does not explicitly show wherein each adjacent vertex along said x-axis is offset in said y-axis direction, or wherein a height of each unit cell is a multiple of said offset of said vertices.
However, Alexeev drawn to augmented or virtual reality devices explicitly shows intersecting linear diffractive features at +/- 30 degree angles (Fig. 5 and C. 7, ll. 10-32), and offset vertices (Fig. 12d)
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have varied the angle of the linear diffractive features of the modified Vuzix ‘620 according to the teachings of Alexeev for the purpose of improving angular uniformity of colors and improved diffraction efficiency of the disclosed geometry (Alexeev, C. 7, ll. 33-46).
Alexeev does not remedy Vuzix ‘630’s silence concerning wherein a height of each unit cell is a multiple of said offset of said vertices.
However, 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 fields of diffraction and photonics, it is exceptionally well known that optical dimensions of the employed structure are results effective with respect to the incident light’s wavelength and angle. It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have optimized the size of the unit cells of the modified Vuzix ‘630 toward achieving improved angular uniformity of colors and improved diffraction efficiency of the disclosed geometry, thus achieving the claimed dimensional relationship.
Regarding claim 22, the modified Vuzix ‘630 teaches the image light guide for conveying image bearing light according to claim 21, but does not explicitly show wherein each said unit cell defines an irregular hexagon. However, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention that implementing the vertex offset of Alexeev to the device of Vuzix ‘630 for the purpose of achieving improved angular uniformity of colors and improved diffraction efficiency of the disclosed geometry would displace the vertices of the hexagonal unit cells and thus result in an irregular shape.
Conclusion
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/COLLIN X BEATTY/Primary Examiner, Art Unit 2872
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