Prosecution Insights
Last updated: April 19, 2026
Application No. 18/689,559

OPTICAL FILTER AND LIGHTING UNIT COMPRISING THE SAME

Non-Final OA §103
Filed
Mar 06, 2024
Examiner
PENG, CHARLIE YU
Art Unit
2874
Tech Center
2800 — Semiconductors & Electrical Systems
Assignee
Coelux S R L
OA Round
1 (Non-Final)
75%
Grant Probability
Favorable
1-2
OA Rounds
2y 6m
To Grant
88%
With Interview

Examiner Intelligence

Grants 75% — above average
75%
Career Allow Rate
878 granted / 1166 resolved
+7.3% vs TC avg
Moderate +13% lift
Without
With
+13.0%
Interview Lift
resolved cases with interview
Typical timeline
2y 6m
Avg Prosecution
34 currently pending
Career history
1200
Total Applications
across all art units

Statute-Specific Performance

§101
1.1%
-38.9% vs TC avg
§103
46.9%
+6.9% vs TC avg
§102
31.7%
-8.3% vs TC avg
§112
15.0%
-25.0% vs TC avg
Black line = Tech Center average estimate • Based on career data from 1166 resolved cases

Office Action

§103
DETAILED ACTION 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, 7, 8, 14, 15 is/are rejected under 35 U.S.C. 103 as being unpatentable over U.S. Patent 9,176,340 B1 by Mahdi et al. in view of U.S. PGPub 2006/0251365 A1 by Brewer. Regarding claim 1, Mahdi teaches an optical filter (fiber optic face plate/FOFP 120) comprising: a first surface substantially flat and a second surface substantially flat and parallel to said first surface (the surfaces are not illustrated but are inherently present as the two opposing faces of the FOFP 120); a plurality of optically transparent channels (a plurality of optical fibers forming the FOFP 120), parallel to each other , and made of at least one solid material, each channel (each fiber 130, Fig. 2) having an elongated conformation along a longitudinal axis (Y-Y) (horizontal/longitudinal axis of the fiber 130) and extending between said first surface and said second surface (end faces of the fiber 130 coincide with the first and second surfaces of the FOFP 120), each channel (130) having a respective side surface (circumferential surface of the fiber 130); wherein each channel (130) comprises at least: a central core (136) having a first refractive index; a first cladding (138), which that wraps the outer side surface of said central core (136); said first cladding (138) having a second refractive index smaller than said first refractive index (1.6>1.5 or 1.75>1.55 as stated in col. 4, ll. 24-29); and a first optically absorbing material (black glass cladding layer 139 disposed outside the normal cladding layer) interposed between the side surface of adjacent channels, wherein said first optically absorbing material (139) is configured to reduce the passage of light through adjacent channels (i.e., by absorbing light propagating through the FOFP 120). Mahdi further states the cutoff angle to be 33° or 54°, depending on the refractive indices of the core and first cladding (see Fig. 2A and description). Mahdi does not specify an average channel radius or whether a longitudinal axis length relationship is satisfied. Brewer also teaches a display apparatus having a fiber optic face plate, wherein optical fibers used in the fiber optic face plate have a diameter range of 100 microns to 300 microns, and the fiber optic face plate has a thickness of a couple of millimeters (See Figs. 2A, 2B and descriptions). Based on these dimensions, i.e., channel radius of up to 150 microns and channel axis length (thickness of the fiber optic face plate) of 2 mm, the relationship of L < ALo is satisfied since ALo (at A=5) equals to 5.0 mm (54°) or 6.6 mm (33°). It would have been obvious to one having ordinary skill in the art, before the effective filing date of the claimed invention, to modify Mahdi’s invention, by using the FOFP dimensions, including the sizes of the optical fibers used therein, as suggested by Brewer, since the construction of the optical fiber’s core and cladding proves to provide acceptable level of image quality and minimizes crosstalk or interfacial loss while light travels between the input and output faces of the FOFP. Regarding claim 7, Mahdi further teaches determining the cutoff angle (θmax) using the refractive indices of the core and the first cladding (col. 4, ll. 12-29). Regarding claim 8, Mahdi further teaches each channel has a substantially circular section (Fig. 2). Regarding claim 14, Mahdi further teaches said central core (136) of each channel (130) has a substantially circular section (Fig. 2A). Regarding claim 15, Mahdi further teaches a plurality of statistically equivalent channels (130) (the channels appear identical for the purpose of the invention). Claim(s) 21, 27 is/are rejected under 35 U.S.C. 103 as being unpatentable over Madhi and Brewer et al. as applied to claim 1 above, and further in view of U.S. PGPub 2002/0114148 A1 by Flohr et al. Regarding claims 21, 27, Madhi and Brewer suggest an optical filter/the FOFP but not an adjacent reflective surface or natural light source. Flohr also teaches using a filter/fiber optic plate (5) in a display device (Fig. 1), a light source (11), and a reflective surface (12) positioned adjacent to a first substantially flat surface (10) of the fiber optic plate (5), so as to inject light generated by the light source (11) into the fiber optic plate, and wherein if the light source (11) is not in operation, ambient light (natural light) enters the fiber optic plate (6). It would have been obvious to one having ordinary skill in the art, before the effective filing date of the claimed invention, to modify Mahdi’s invention, by using a reflective surface adjacent to an input side of the FOFP, as suggested by Flohr, for the same purpose. Allowable Subject Matter Claims 2-6, 18-20 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. Relevant prior art fails to further teach or suggest an optical filter having a plurality of core/cladding optical channels, each of which has a discrete refractive index profile that maximizes at the core center, when considered in view of rest of the limitations of the claimed invention. Claims 22, 23 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. Relevant prior art fails to further teach or suggest a chromatic diffusion layer comprising a rear surface positioned adjacent or in contact, to the substantially flat second surface of the optical filter, wherein the chromatic diffusion layer comprises a plurality of substantially transparent nanoelements dispersed in a substantially transparent matrix, the nanoelements and the matrix having different refractive indexes, and is configured such that the light reflective unit produces a first direct light at a first CCT at polar angles lower than the cut-off angle and a second diffused light at a second CCT at polar angles greater than the cut-off angle, with the second CCT being equal to at least 1.2 times the first CCT, when the incident light is the standard illuminator CIE E, when considered in view of the rest of the limitations of the claimed invention. Claims 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. Relevant prior art fails to further teach or suggest a direct light source configured to emit visible light in a non-isotropic manner and an optical filter as in claim 1 positioned downstream of the direct light source so that the input surface of the optical filter is illuminated by the light emitted from the direct light source, when considered in view of the rest of the limitations of the claimed invention. Claim 28 is 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. Relevant prior art fails to further teach or suggest a diffused light source configured to emit a diffused visible light having a colour correlated temperature or CCT at least 1.2 times greater than a CCT of natural light/5600 Kelvin; or a chromatic diffusion layer comprising a plurality of substantially transparent nanoelements dispersed in a substantially transparent matrix, the nanoelements and the matrix having different refractive indexes, and being configured such that the natural lighting unit produces a first direct light at a first CCT at polar angles lower than the cut-off angle and a second diffused light at a second CCT at polar angles greater than the cut-off angle, with the second CCT being equal to at least 1.2 times the first CCT, when the incident light is the standard illuminator CIE E, when considered in view of the rest of the limitations of the claimed invention. Conclusion The prior art made of record and not relied upon is considered pertinent to applicant's disclosure. US5959711 discloses an FOFP. Any inquiry concerning this communication or earlier communications from the examiner should be directed to CHARLIE PENG whose telephone number is (571)272-2177. The examiner can normally be reached 9AM - 6PM. Examiner interviews are available via telephone, in-person, and video conferencing using a USPTO supplied web-based collaboration tool. To schedule an interview, applicant is encouraged to use the USPTO Automated Interview Request (AIR) at http://www.uspto.gov/interviewpractice. If attempts to reach the examiner by telephone are unsuccessful, the examiner’s supervisor, Thomas Hollweg can be reached at (571)270-1739. The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300. Information regarding the status of published or unpublished applications may be obtained from Patent Center. Unpublished application information in Patent Center is available to registered users. To file and manage patent submissions in Patent Center, visit: https://patentcenter.uspto.gov. Visit https://www.uspto.gov/patents/apply/patent-center for more information about Patent Center and https://www.uspto.gov/patents/docx for information about filing in DOCX format. For additional questions, contact the Electronic Business Center (EBC) at 866-217-9197 (toll-free). If you would like assistance from a USPTO Customer Service Representative, call 800-786-9199 (IN USA OR CANADA) or 571-272-1000. /CHARLIE Y PENG/Primary Examiner, Art Unit 2874
Read full office action

Prosecution Timeline

Mar 06, 2024
Application Filed
Mar 06, 2026
Non-Final Rejection — §103 (current)

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Study what changed to get past this examiner. Based on 5 most recent grants.

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Prosecution Projections

1-2
Expected OA Rounds
75%
Grant Probability
88%
With Interview (+13.0%)
2y 6m
Median Time to Grant
Low
PTA Risk
Based on 1166 resolved cases by this examiner. Grant probability derived from career allow rate.

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