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 .
Remark
This Office Action is in response to applicant’s amendment filed on August 18, 2026, which has been entered into the file.
By this amendment, the applicant has amended claims 1-8, 10-20.
Claims 1-20 remain pending in this application.
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.
Claims 1-20 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.
Claim 1 has been amended to include the phrase “at least two regions of the expansion diffraction grating include first region including a first plurality of diffraction gratings and a second region including a second plurality of diffraction gratings” that are confusing and indefinite. For all of the figures disclosed by the specification of originally filed, the first region and the second region each only includes a diffraction grating not a plurality of diffraction gratings. It is therefore not clear what are these plurality of diffraction gratings and how they are different or relate the to the one diffraction grating disclosed in all of the figures.
In light of the amendment to claim 1 mentioned above, the phrase “a sum of a grating vector for incidence diffraction grating, a grating vector for the expansion diffraction grating…” recited in claim 1 is confusing and indefinite since if each expansion regions has a plurality of diffraction gratings then which grating vector of the plurality of diffraction gratings is considered here for the sum of the grating vectors?
Furthermore, it is not clear how do the first diffraction grating and the second diffraction grating recited in claim 2 relate to the plurality of diffraction gratings in the first region and the second region.
The amended phrase “plurality of incidence diffraction grating including the incidence diffraction grating” and the phrase “plurality of emission diffraction grating including the emission diffraction grating” recited in amended claim 19 are really confusing and indefinite.
The scopes of the claims therefore are confusing and indefinite. Claims 2-20 inherit the rejection from their base claim.
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.
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) 1-7 and 14-20 is/are rejected under 35 U.S.C. 103 as being unpatentable over the US patent application publication by Messer et al (US 2020/0400955 A1) in view of the US patent application publication by Levola (US 2010/0214659 A1).
Claim 1 has been significantly amended to necessitate the new grounds of rejection.
Messer et al teaches, with regard to amended claim 1, an eyepiece waveguide serves as the light guide plate that is comprised of an input coupling grating (ICG) (2340, Figure 23) serves as the incident diffraction grating configured to diffract light (2341) that is incident into the waveguide or light guide plate, a waveguide or substrate (2300) configured to internally and totally reflect the light diffracted into the light guide plate by the incidence diffraction grating and guide the light, (please see Figure 9A and 13F). Messer et al teaches that the light guide plate further comprises a orthogonal pupil expander (OPE, 2350a and 2350b, Figure 23) comprises OPE grating (please see Figure 14A, paragraph [0220]) serves as the expansion diffraction grating, configured to diffract and expand the light guided by the substrate or waveguide, and an exit pupil expander (EPE, 2360, Figure 23) comprises EPE grating, (please see Figure 14A and paragraph [0221] serves as the emission diffraction grating configured to diffract the light diffracts by the expansion diffraction grating and project the light into pupil of an observer (please see Figure 122A). Messer et al teaches that the expansion diffraction grating comprises at least two regions in front view of the light guide plate, that are a first or left OPE region (2350a, Figure 23) and a second or right OPE region (2350b, Figure 23).
A sum of the grating vector for the incidence diffraction grating (2340), a grating vector for the expansion diffraction grating (2350a and 2350b) and a basic grating vector for the emission diffraction grating is zero (for the vector sum as shown in Figure 23). A grating vector for a diffraction grating is in the direction perpendicular to the grating lines.
As shown in the Figure 23, a direction of a corresponding grating vector of the expansion diffraction grating in the first region (2350a) is in a different direction from a direction of a corresponding grating vector for the expansion diffraction in the second region (2350b).
As for the grating vector of the diffraction having the highest diffraction efficiency among the diffraction gratings for the first or second regions, this feature is implicitly met by the first region expansion diffraction grating and second region expansion diffraction grating.
Claim 1 has been amended to include the phrase “the at least two regions of the expansion diffraction grating include a first region including a plurality of diffraction gratings and a second region including a second plurality of diffraction gratings”. This phrase has been rejected under 35 USC 112, second paragraph, for the reasons set forth above. Since the specification and claims fail to provide definite definition of these plurality of diffraction gratings, this feature can only be examined in the broadest interpretation.
Levola in the same field of endeavor teaches a diffractive beam expander wherein the expansion diffraction grating may comprise at least two regions wherein the first region includes a first plurality of diffraction gratings (21a and 22c, Figure 9) and the second region includes a second plurality of diffraction gratings (22a and 21c) wherein the different diffraction gratings configured to expand different portions of the incident light, (please see Figure 9).
It would then have been obvious to one skilled in the art to apply the teachings of Levola to make the two regions of the expansion diffraction grating comprise a plurality of diffraction gratings for the benefit of expanding different portions of the incident light.
With regard to amended claim 2, Levola teaches a diffractive expander and light guide display further comprises of a first restoring grating (21b, please see Figures 3a, 8a, 8c, 9 and 10a) serves as the first diffraction grating configured to diffract to the emission diffraction grating (30) the light diffracted by the expansion diffraction grating and a second restoring grating (22b) serves as the second diffraction grating configured to diffract to the emission diffraction grating (30) the light diffracted by the expansion diffraction grating. The first diffraction grating (21b) is opposite to the second diffraction grating (22b), in the front view.
Levola in a different embodiment (Figure 6) that the first region and the second region of the expansion diffraction gratings (21 and 22) that each may comprise an expansion diffraction grating portion and a restoring grating portion (as indicated below in the figure). The restoring grating portions that are opposite to each other and diffract light to the emission diffraction grating (30). The restoring grating portions interposed the expansion diffraction portions therebetween.
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Levola teaches that the pitch and direction of the diffraction gratings provided for the expansion diffraction gratings (21a and 22a) are identical to the pitches and direction of the diffraction gratings provided for the restoring gratings (21b and 22b).
In different embodiment, Figure 9, Levola teaches that the expansion diffraction grating (21c and 22c) may also be interposed between the diffraction grating and the second diffraction in the front view. Levola teaches that a pitch and a direction of a corresponding one of the first plurality of diffraction gratings in the first region (such as 21a, Figure 9) for the expansion diffraction are identical to a pitch and a direction of the first diffraction grating (21b) and a pitch and a direction of a corresponding one of the second plurality of diffraction gratings in the second region (such as 22a, Figure 9) for the expansion diffraction are identical to a pitch and a direction of the first diffraction grating (22b).
This means it is within general level skilled in the art to design the expansion diffraction grating be interposed between the returning or first and second diffraction gratings.
With regard to amended claim 3, Levola teaches that the first region (21a, Figures 8c, 9 and 10a) is adjacent to the second restoring diffraction grating (22b) and the second region (22a) is adjacent to the first restoring diffraction grating (21b).
With regard to amended claims 4-6, Levola teaches that the first region (21a), the second region (22a) and the first restoring grating (21b) and the second restoring grating (22b) are disposed on one surface of the substrate or waveguide, (please see Figure 2a), as recited in claim 6. With regard to claims 4 and 5, Messer et al teach that the expansion diffraction grating may be placed at either the same side or different side of the substrate or the waveguide, (please see Figures 25A and 26A). It would then have been obvious to one skilled in the art to modify the light guide plate to either have the first region and the first diffraction grating disposed on one surface and the second region and the second diffraction grating disposed on the other surface of the substrate, (as in Figure 26A). It would then also have been obvious to one skilled in the art to modify the light guide plate to have the first and second regions disposed on one surface of the substrate and the first and second diffraction grating disposed on the other surface, as obvious design by one skilled in the art.
With regard to claim 7, Levola teaches to include a clearance is formed at least in part of the incidence diffraction grating (B1, Figures 3a and 9) between the first region and the second region (21a and 22a) and the clearance is formed at a center of divergence of a pencil light emitted from the incidence diffraction grating to the expansion diffraction grating.
With regard to amended claim 14, in light of the amendment to the based claim, Levola teaches in a different embodiment to include third diffraction grating (intersecting section, Figure 8a), such that the third diffraction grating is between the first region (21a) and the first diffraction grating (21b). The pitch and direction of the corresponding one of the first plurality of the first plurality of diffraction gratings for the first region is identical to the pitch and the direction of the third diffraction grating, (please see Figure 8a). As for the feature concerning lower diffraction efficiency, such feature is considered obvious to one skilled in the art for the benefit of allowing incident light be diffracted.
With regard to amended claim 15, as shown in Figure 6, Levola teaches to comprise a fourth region that is adjacent to the first region and has a flat entry face for the light between the first region and the first diffraction grating.
With regard to amended claim 16, both Messer et al and the Levola teach that the first plurality of diffraction gratings and the second plurality of diffraction grating for the expansion diffraction grating are placed in a two dimensional array, (please see 2350a/2350b in Figure 23 of Messer et al and 21a/22a of all figures of Levola). A pitch of a diffraction order for the highest diffraction efficiency among respective pitches of the first plurality of diffraction gratings and the second plurality of diffraction gratins for the expansion diffraction grating is equal to the pitch of the first diffraction grating or the second diffraction grating.
With regard to amended claim 17, as shown in Figure 23, Messer et al teaches a grating vector provided for the first diffraction grating is a vector connecting a terminal point of the corresponding grating vector of the one of the first plurality of diffraction gratings for the first region and a second terminal point of the corresponding grating vector of the one of the second plurality of diffraction gratings of diffraction grating for second region.
With regard to claim 18, Messer et al teaches that the emission diffraction grating is disposed at different position with respect to the incidence diffraction grating in the thickness direction of the light guide.
With regard to amended claim 19, Messer et al teaches that the light guide plate may include a plurality of incident diffraction gratings (700, 710, 720, please see Figure 9B) and a plurality of emission diffraction gratings (800, 801 and 820).
With regard to claim 20, Messer et al teaches an image display device that comprises the light guide plate and an image forming unit that or light modulator (540, Figure 6, or 1207, Figure 12A) configure to project image light onto the light guide plate.
Claim(s) 8 and 9 is/are rejected under 35 U.S.C. 103 as being unpatentable over Messer et al and Levola as described in claim 1 above and further in view of the US patent issued to Park et al (US 12,147,041).
The light guide plate taught by Messer et al in combination with the teachings of Levola as described in claim 1 above have met all the limitations of the claims.
With regard to claims 8 and 9, Messer et al in a different embodiment teaches that the first and second regions of the expansion diffraction grating may be formed to have an overlapped structure or a multiple combined pupil expanders (CPE, please see Figure 25A). It however does not have a structure with a first region, a second region and a third region of the overlap of the first and second regions. Park et al in the same field of endeavor teaches a diffraction grating that is comprised of a first region of the diffraction grating having a first grating structure (131, Figure 4), a second grating structure (132) and a third grating structure (133) that is an overlap of the first and second grating structures. It would then have been obvious to one skilled in the art to apply the teachings of Park et al to modify the combined pupil expander to have first, second and third regions of the diffraction gratings with the third region having a two dimensional periodic structure of the overlapped first and second diffraction structure.
Claim(s) 10-13 is/are rejected under 35 U.S.C. 103 as being unpatentable over Messer et al and Levola as described in claim 1 above and further in view of the US patent application publication by Olkkonen et al (US 2021/0215942 A1).
The light guide plate taught by Messer et al in combination with the teachings of Levola as described in claim 1 above have met all the limitations of the claims.
With regard to claim 10, Messer et al teaches to include diffractive mirror (2070, Figure 20L) that is capable of diffracting the light in an inward direction and the diffractive mirror may serve as the return diffraction grating that is an outer periphery or outside a region where light is incident from the substrate and is disposed of at least of outer periphery of the expansion diffraction grating (2050). Olkkonen et al in the same field of endeavor teaches a light guide plate wherein grating mirror (531D-534D, Figure 5D) serves as the returning grating that is disposed at an outer peripheral of the emission diffraction grating (560D, please see Figure 5D and paragraph [0049]). It would then have been obvious to one skilled in the art to apply the teachings of Olkkonen et al to modify the diffractive mirror to be disposed at the peripheral of the emission diffraction grating for the benefit of allowing the escaped light to be diffracted back to the emission diffraction grating for the benefit of enhancing the projection of the light to the pupil of the observer.
With regard to claims 11-13, both Messer et al and Olkkonen et al teach that the return diffraction grating or diffractive mirror may have a one dimensional periodic structure. It is within general level skilled in the art to design the grating vector of the return diffraction grating in relating to the basic or grating vector of the emission diffraction grating for the benefit of allowing the returning diffraction grating to efficiently diffract the light inwardly toward the emission diffraction grating.
Response to Arguments
Applicant's arguments filed August 18, 2026 have been fully considered but they are not persuasive. The newly amended claims have been fully considered and they are rejected for the reasons set forth above.
The applicant is respectfully reminded that the phrase “diffraction grating” has been used numerous times to refer different components of the guide plate that make the language of the claims very confusing.
Applicant’s claims seem to include various embodiments however the claims do not seem to provide proper structural relationships for the various elements that are in the different embodiments. Specifically, the specification fails to provide explicitly structural relationship of the plurality of diffraction gratings in the expansion diffraction grating with the incidence diffraction grating and the emission diffraction grating.
As for the feature concerning the highest diffraction efficiency, the applicant being one skilled in the art that for a diffraction grating that has specific grating constant, the diffraction efficiency is determined by the light diffracted by the diffraction grating according to the diffraction theory. The grating constant in light of the diffraction theory would allow the light having specific wavelength to be diffracted with higher efficiency when it satisfies the diffraction theory, (i.e. d*(sin qI +sin qm) = m*l, with d being the grating pitch, qI incident angle, qm diffraction angle and l wavelength. So, the “highest diffraction efficiency” is determined by the operation condition of the diffraction grating, specifically as cited references disclose that the incident light is diffracted by the incidence diffraction grating via the expansion diffraction grating to the emission diffraction grating, the highest diffraction efficiency is included by the incident light that best matches the diffraction theory.
Conclusion
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 AUDREY Y CHANG whose telephone number is (571)272-2309. The examiner can normally be reached M-TH 9:00AM-4:30PM.
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If attempts to reach the examiner by telephone are unsuccessful, the examiner’s supervisor, Stephone B Allen can be reached at 571-272-2434. The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300.
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AUDREY Y. CHANG
Primary Examiner
Art Unit 2872
/AUDREY Y CHANG/ Primary Examiner, Art Unit 2872
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