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 .
Response to Arguments
Applicant’s arguments with respect to claim(s) 1, 3, 5, and 22 have been considered but are moot because the new ground of rejection does not rely on any reference applied in the prior rejection of record for any teaching or matter specifically challenged in the argument.
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.
Claim(s) 1, 3, 5, 20 and 22-23 is/are rejected under 35 U.S.C. 103 as being unpatentable over Magic Leap Inc. WO 2020/112836 A1 (cited on IDS filed 3 July 2024; hereinafter “Magic Leap”) in view of Tervo (US 20180292653 A1).
Regarding claim 1, Magic Leap discloses an image light guide ([0050]-[0057]; FIG. 8) for conveying a virtual image ([0002], [0050]), comprising:
a substrate (“planar waveguide layer” 810) operable to propagate image-bearing light beams (801, 817; [0051])
a first in-coupling diffractive optic (812; [0050]) formed along said substrate (FIG. 8), wherein said in-coupling diffractive optic is operable to diffract a first portion (803) of said image-bearing light beams ([0051]: “A first portion of the image light represented by ray 801 is diffracted by the first incoupling diffractive optical element 812 as illustrated by ray 803”) from an image source (“projector,” not shown; [0050]) into said substrate in an angularly encoded form (see FIG. 8 – portion 803 is diffracted into substrate 810 at an angle, which meets the broadest reasonable interpretation of “in an angularly encoded form”), and wherein said in-coupling diffractive optic is operable to transmit a second portion (“remaining portion” of ray 801) of said image-bearing light beams from said image source ([0051]; FIG. 8);
an out-coupling diffractive optic (“exit pupil expander (EPE)” 819; [0051]) formed along said substrate (FIG. 8), wherein said out-coupling diffractive optic is operable to expand an eyebox in at least one direction (this is indicated by use of the term “exit pupil expander”) and direct said image-bearing light beams from said substrate in an angularly decoded form (the examiner understands the broadest reasonable interpretation of this limitation to mean only that the image as projected by the projector is visible to a viewer, which must necessarily be the case in order for the device to function as a display system; [0023]);
a second in-coupling diffractive optic (814) formed along said substrate (FIG. 8), wherein said second in-coupling diffractive optic is operable to diffract a portion (805, 807) of said second portion of said image-bearing light beams into said substrate in an angularly decoded form (FIG. 8);
an optical coupler (“retroreflector” 816; [0052], [0068]; FIG. 11) located along an axis of said image source (ray 801 from the image source is considered to define “an axis of said image source,” and optical coupler 816 is clearly along this axis; FIG. 8), wherein said optical coupler is operable to direct said second portion of image-bearing light beams to said second in-coupling diffractive optic ([0055]; FIG. 8).
Magic Leap fails to teach a second in-coupling diffractive optic formed offset from said first in-coupling diffractive optic in a direction laterally transverse a direction of propagation of said image-bearing light beams to said out-coupling diffractive optic.
Tervo discloses various gratings to be used for in-coupling DOE where a second in-coupling diffractive optic formed offset from a first in-coupling diffractive optic in a direction laterally transverse a direction of propagation of said image-bearing light beams to said out-coupling diffractive optic (figs. 11-22).
Before the effective filing date of the instant application, it would have been obvious to one of ordinary skill in the art to utilize the two-sided in-coupling DOE having different grating vectors on each surface as taught by Tervo in the device of Magic Leap to reduce the cross-coupling and increase uniformity between colors (Tervo: [0004]).
Regarding claim 3, Magic Leap/ Tervo additionally discloses wherein said first in-coupling diffractive optic (812) is operable as a transmissive type diffractive optic and said second in-coupling diffractive optic (814) is operable as a reflective type diffractive optic ([0055]).
Regarding claim 5, Magic Leap/ Tervo additionally discloses wherein said substrate (810) comprises first and second opposing surfaces (“front surface” 821 and “back surface” 822, respectively; [0053]; FIG. 8), but fails to teach said first in-coupling diffractive optic (812) and said second in-coupling diffractive optic (814) are located in said first surface.
Tervo discloses a first in-coupling diffractive optic (1110) and a second in-coupling diffractive optic (1120) are located in the same surface (fig. 11) or opposite surfaces (fig. 12).
Before the effective filing date of the instant application, it would have been obvious to one of ordinary skill in the art to utilize the different arrangement of in-coupling DOE as taught by Tervo in the device of Magic Leap as alternative implementations for in-coupling, including, for example, refraction index-modulated, refraction index-switched, or polarization gratings, to enhance coupling efficiency (Tervo: [0047]).
Regarding claims 7-8, Magic Leap/ Tervo additionally discloses wherein said substrate (810) comprises first and second opposing surfaces (“front surface” 821 and “back surface” 822, respectively; [0053]; FIG. 8), but fails to teach said first in-coupling diffractive optic and said second in-coupling diffractive optic comprise slanted surface relief grating features, and said grating features are slanted substantially one-hundred-eighty degrees relative to said grating features of said first in-coupling diffractive optic; or said first in-coupling diffractive optic and said second in-coupling diffractive optic comprise blazed surface relief grating features, and said grating features of said second in-coupling diffractive optic are symmetric to said grating features of said first in-coupling diffractive optic.
Tervo discloses gratings may include symmetric and/or asymmetric features including slanted gratings with slant angles α1, α2 and blazed gratings (figs. 18-22; [0053-0055]), and slant angle of grating features between first in-coupling grating and second in-coupling grating is substantially 180 degrees (slanted in opposite directions; [0047]).
Before the effective filing date of the instant application, it would have been obvious to one of ordinary skill in the art to utilize Tervo’s different types of grating features for the in-coupling DOE of Magic Leap as alternative implementations for intended use since such modification is merely a matter of design choice in accordance to the needs of a particular implementation (Tervo: [0054]).
Regarding claim 20, Magic Leap/ Tervo additionally discloses wherein:
said first portion (803) of said image-bearing light beams in-coupled via said first in-coupling diffractive optic (812) correspond to a first virtual image ([0051],
said second portion (807) of said image-bearing light beams in-coupled via said second in-coupling diffractive optic correspond to a second virtual image ([0055]),
wherein said first and second virtual images are substantially identical (since 803 and 807 are different portions of the same incoming image light 801, they are understood to be substantially identical),
wherein said substrate (810) is rotated such that a surface of said substrate is positioned at an angle relative to a first surface of said optical coupler (e.g., one of the slanted back surfaces of retroreflector 816; see annotated FIG. 11 below, compare to FIG. 8), whereby said first and second virtual images are aligned at an infinity focus (images 803, 807 travel along parallel trajectories through substrate 810 and are therefore infinity focused).
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Regarding claim 22, Magic Leap teaches an image light guide system (“eyepiece” 1030; [0063]; FIG. 10A) for conveying a virtual image ([0002]), comprising:
an image source (“five arrayed light sources”; [0062]; FIG. 10B) operable to project image-bearing light beams ([0063]) corresponding to a virtual image along a first axis (direction traveled by ray 1062 in FIG. 10A), wherein pixels of said virtual image are infinity focused (see FIG. 10A – the light rays corresponding to the virtual image are parallel, which indicates they are infinity focused);
a first substrate (“planar waveguide” 1034) operable to propagate said image-bearing light beams ([0063], line 30);
a second substrate (“planar waveguide” 1036) operable to propagate said image-bearing light beams ([0063], line 30), wherein said second substrate is coupled with said first substrate (the first and second substrates are part of the same “eyepiece” and are considered to meet the broadest reasonable interpretation of “coupled”);
wherein each of said first and second substrate comprise:
a first in-coupling diffractive optic (DOE B1, not shown, on substrate 1034, and DOE R1 on substrate 1036; [0062], lines 10-12 and 19-21),
a second in-coupling diffractive optic (DOE B2, not shown, on substrate 1034, and DOE R2 on substrate 1036; [0062], lines 10-12 and 19-21);
an optical coupler (“retroreflector” 1040) located along said first axis, wherein said optical coupler is located at least partially along a path of said image-bearing light beams transmitted through said first in-coupling diffractive optics of said first and second substrates (see FIG. 10A), wherein said optical coupler is operable to direct said image-bearing light beams to said second in-coupling diffractive optic of said second substrate (“light cone” 1020 represents the path of light directed by optical coupler 1040 and clearly includes said second in-coupling diffractive optic of said second substrate; [0063], last four lines; FIG. 10A), wherein said second in-coupling diffractive optic is operable to diffract a portion of said image-bearing light beams into said second substrate in an angularly encoded form and transmit a portion of said image-bearing light beams toward said second in-coupling diffractive optic of said first substrate (see FIG. 10A), and wherein said second in-coupling diffractive optic of said first substrate is operable to diffract a portion of said image bearing light beams into said first substrate in an angularly encoded form (see FIG. 10A).
Magic Leap does not teach, in the embodiment of FIG. 10A, wherein each first and second substrate comprises an out-coupling diffractive optic as claimed. Magic Leap is generally silent as to how light is out-coupled from the image light guide in the embodiment of FIG. 10A. However, in other embodiments of the invention, Magic Leap discloses an out-coupling diffractive optic (“exit pupil expander (EPE)” 819; [0051]) formed along said substrate (FIG. 8), wherein said out-coupling diffractive optic is operable to expand an eyebox in at least one direction (this is indicated by use of the term “exit pupil expander”) and direct at least a portion of said image-bearing light beams from said substrate in an angularly decoded form (the examiner understands the broadest reasonable interpretation of this limitation to mean only that the image as projected by the projector is visible to a viewer, which must necessarily be the case in order for the device to function as a display system; [0023]). Therefore, before the effective filing date of the instant application, it would have been obvious to one of ordinary skill in the art to incorporate an out-coupling diffractive optic as described by the claim into each of said first and second substrates for the purpose of out-coupling different colors of light from each substrate, thereby rendering obvious instant claim 22. Since Magic Leap does not specifically discuss out-coupling in the context of the embodiment shown in FIG. 10A, one of ordinary skill in the art would naturally use the out-coupling diffractive optics explicitly taught for the embodiment of FIG. 8 to out-couple light from other embodiments of the image light guide.
Magic Leap fails to teach a second in-coupling diffractive optic formed offset from said first in-coupling diffractive optic in a direction laterally transverse a direction of propagation of said image-bearing light beams to said out-coupling diffractive optic.
Tervo discloses various gratings to be used for in-coupling DOE where a second in-coupling diffractive optic formed offset from a first in-coupling diffractive optic in a direction laterally transverse a direction of propagation of said image-bearing light beams to said out-coupling diffractive optic (figs. 11-22).
Before the effective filing date of the instant application, it would have been obvious to one of ordinary skill in the art to utilize the two-sided in-coupling DOE having different grating vectors on each surface as taught by Tervo in the device of Magic Leap to reduce the cross-coupling and increase uniformity between colors (Tervo: [0004]).
Regarding claim 23, Magic Leap/ Tervo does not explicitly teach in the embodiment of FIG. 10A that each said first in-coupling diffractive optic (DOE R1, DOE B1) is operable as a transmissive type diffractive optic and each said second in-coupling diffractive optic (DOE R2, DOE B2) is operable as a reflective type diffractive optic. However, in other embodiments of the invention, Magic Leap discloses wherein said first in-coupling diffractive optic (812) is operable as a transmissive type diffractive optic and said second in-coupling diffractive optic (814) is operable as a reflective type diffractive optic ([0055]). Therefore, before the effective filing date of the instant application, it would have been obvious to one of ordinary skill in the art to make each said first in-coupling diffractive optic operable as a transmissive type diffractive optic and each said second in-coupling diffractive optic operable as a reflective type diffractive optic for the purpose of coupling light into the first and second substrates by a desired method, thereby rendering obvious instant claim 23.
Claim(s) 4 is/are rejected under 35 U.S.C. 103 as being unpatentable over Magic Leap in view of Tervo as applied to claim 3 above, and further in view of Schultz et al. US 2019/0011708 A1 (hereinafter “Schultz”).
Regarding claim 4, Magic Leap/ Tervo does not explicitly teach wherein said first in-coupling diffractive optic (812) and said second in-coupling diffractive optic (814) comprise surface relief gratings.
It is known in the art to use surface relief gratings to form diffractive optics in image light guides. For example, Schultz teaches an image light guide (100; FIG. 3B) comprising in-coupling diffractive optics (110) and out-coupling diffractive optics (120). Schultz explicitly teaches that there are several suitable ways in which to form the diffractive optics, and one such way is to form the in-coupling and out-coupling optics as surface relief gratings ([0003], [0083]).
Therefore, before the effective filing date of the instant application, it would have been obvious to one of ordinary skill in the art, based on the teachings of Schultz, to form the first and second in-coupling diffractive optics comprising surface relief gratings for the purpose of using a known, suitable grating type as the diffractive optics in the device of Magic Leap/ Tervo, thereby rendering obvious instant claim 4. The selection of a known material (e.g., a surface relief grating) based on its suitability for its intended use (e.g., as an in-coupling diffractive optic in an image light guide) has been held to be obvious. In re Leshin, 277 F.2d 197, 125 USPQ 416 (CCPA 1960).
Claim(s) 17 is/are rejected under 35 U.S.C. 103 as being unpatentable over Magic Leap in view of Tervo as applied to claim 1 above, and further in view of Wheelwright et al. US 2021/0096453 A1 (hereinafter “Wheelwright”).
Regarding claim 17, Magic Leap/ Tervo does not teach a waveplate located between said optical coupler (816) and said second in-coupling diffractive optic (814) and therefore also does not teach the remaining limitations of the claim.
It is known in the art to incorporate waveplates between optical couplers and image light guides for the purpose of optimizing the coupling of light into the light guide. For example, Wheelwright teaches an image light guide (“display device” 600-A; [0101]; FIG. 6A) comprising an in-coupling diffractive optic (“in-coupler” 450) and an optical coupler (“reflector” 630) and further comprising a waveplate (“QWP” 620) located between said optical coupler and said in-coupling diffractive optic (see FIG. 6A), wherein said waveplate is operable to rotate a polarization of said image bearing light, wherein said waveplate comprises a half-wave waveplate or a quarter-wave waveplate (QWP = quarter-wave waveplate; [0101]). Schultz teaches that the in-coupling diffractive optic may be polarization selective ([0071]), and it follows that using a waveplate to polarize the incoming light in a particular way will control how much of the light is diffracted into the light guide by the in-coupling diffractive optic.
Therefore, before the effective filing date of the instant application, it would have been obvious to one of ordinary skill in the art, based on the teachings of Wheelwright, to incorporate into the device of Magic Leap/ Tervo a waveplate (Wheelwright 620) located between said optical coupler (Magic Leap 816; Wheelwright 630) and said second in-coupling diffractive optic (Magic Leap 814; Wheelwright 450), wherein said waveplate is operable to rotate a polarization of said image-bearing light beams, wherein said waveplate comprises a half-wave waveplate or a quarter-wave waveplate, thereby rendering obvious instant claim 17. One of ordinary skill in the art would have been motivated to do so in order to control how much of the image-bearing light is diffracted into the light guide by the second in-coupling diffractive optic.
Allowable Subject Matter
Claims 9-15, 21, and 24-25 are objected to as being dependent upon a rejected base claim, but would be allowable if rewritten in independent form including all of the limitations of the base claim and any intervening claims.
The following is a statement of reasons for the indication of allowable subject matter: the closest prior art of record does not disclose or render obvious all of the limitations of claims 9, 21, or 24, in particular: “wherein said optical coupler comprises: a first surface operable to transmit said image-bearing light beams incident thereon at a first angle relative to said first surface and operable to reflect said image-bearing light beams incident thereon at a second angle relative to said first surface” (claims 9 and 24) and “wherein said optical coupler comprises: a first surface operable to transmit said image-bearing light beams incident thereon at a first portion of said first surface and operable to reflect said image-bearing light beams incident thereon at a second portion of said first surface, wherein said second portion of said first surface is a mirrored surface” (claim 21) in combination with all the remaining limitations of each claim. The examiner understands the limitations quoted above to be describing the optical coupler shown in, e.g., FIG. 7B of the instant application and in particular to be describing the function of surface “122” to both transmit and reflect light as shown. The optical coupler of the prior art, in particular the “retroreflector” taught by Magic Leap, does not have a first surface which both transmits and reflects light depending on how/where the light is incident on it, and there would be no clear motivation to modify a retroreflector, which is a specific structure known in the art, to comprise a first surface as claimed.
Claims 10-15 are allowable at least based on their dependency from allowable claim 9.
Claim 25 is allowable for the reason set forth in claim 9 above.
Conclusion
The prior art made of record and not relied upon is considered pertinent to applicant's disclosure. Levola (US 20110096401 A1) teaches slant grating features (figs. 3A-B).
Applicant's amendment necessitated the new ground(s) of rejection presented in this Office action. Accordingly, THIS ACTION IS MADE FINAL. See MPEP § 706.07(a). Applicant is reminded of the extension of time policy as set forth in 37 CFR 1.136(a).
A shortened statutory period for reply to this final action is set to expire THREE MONTHS from the mailing date of this action. In the event a first reply is filed within TWO MONTHS of the mailing date of this final action and the advisory action is not mailed until after the end of the THREE-MONTH shortened statutory period, then the shortened statutory period will expire on the date the advisory action is mailed, and any nonprovisional extension fee (37 CFR 1.17(a)) pursuant to 37 CFR 1.136(a) will be calculated from the mailing date of the advisory action. In no event, however, will the statutory period for reply expire later than SIX MONTHS from the mailing date of this final action.
Any inquiry concerning this communication or earlier communications from the examiner should be directed to Uyen-Chau N. Le whose telephone number is (571)272-2397. The examiner can normally be reached Monday-Friday, 9:00am-5:30pm.
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If attempts to reach the examiner by telephone are unsuccessful, the examiner’s supervisor, Kiesha R. Bryant can be reached at (571) 272-3606. The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300.
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/UYEN CHAU N LE/Supervisory Patent Examiner, Art Unit 2874