Prosecution Insights
Last updated: April 19, 2026
Application No. 18/326,552

LIGHT DIFFUSION SHEET, BACKLIGHT UNIT, LIQUID CRYSTAL DISPLAY DEVICE, INFORMATION APPARATUS, AND METHOD FOR MANUFACTURING LIGHT DIFFUSION SHEET

Non-Final OA §103§DP
Filed
May 31, 2023
Examiner
BRIGGS, NATHANAEL R
Art Unit
2871
Tech Center
2800 — Semiconductors & Electrical Systems
Assignee
Keiwa Inc.
OA Round
3 (Non-Final)
76%
Grant Probability
Favorable
3-4
OA Rounds
2y 9m
To Grant
88%
With Interview

Examiner Intelligence

Grants 76% — above average
76%
Career Allow Rate
811 granted / 1067 resolved
+8.0% vs TC avg
Moderate +12% lift
Without
With
+11.5%
Interview Lift
resolved cases with interview
Typical timeline
2y 9m
Avg Prosecution
35 currently pending
Career history
1102
Total Applications
across all art units

Statute-Specific Performance

§103
56.8%
+16.8% vs TC avg
§102
34.3%
-5.7% vs TC avg
§112
6.3%
-33.7% vs TC avg
Black line = Tech Center average estimate • Based on career data from 1067 resolved cases

Office Action

§103 §DP
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, see pages 6-7, filed 08 January 2026, with respect to the provisional non-statutory double patenting rejection of claims 1-17 have been fully considered and are persuasive, particularly in that the present application has the earlier filing date compared to the reference application and should be allowed to issue to patent. The double patenting rejection of 03 November 2025 has been withdrawn. Applicant's arguments filed 08 January 2026 have been fully considered but they are not persuasive. Regarding claim 1, Applicant argues that: Chung fails to disclose the claimed limitation, “wherein each of the plurality of recesses is directly adjacent to the ridge”, since the recesses P1 are not part of the curved portion 210, which is not part of the ridge C1 (as per Applicant’s interpretation of the device of Chung); it would not have been obvious to combine the teachings of Ahn into the device of Chung since the optical properties of the recess shapes and flat ridges of Ahn are different than that of Chung, and, furthermore, it would not be obvious to modify the curved ridges of Chung to be flat as per the teaching of Ahn; it would not be obvious to apply the teachings of Takizawa to the device of Chung because the recesses of Takizawa are not in a pyramid shape. Regarding i.), Applicant’s interpretation of Chung is not proper (i.e., that the ridge portion C1 is separate from the curved portion 210). First, based on Applicant’s own disclosure in figure 9 and 10, each ridge between recesses 22 comprises curved portion 23. Thus, the ridge and curved portion are inseparable. Likewise, according to the same logic and reasonable interpretation, Chung discloses in figures 2A-2E recesses 220 which are separated by the tops of protrusions 210 which comprise curved portions C1. Thus, the ridges of Chung are inseparable from curved portions C1, contra Applicant’s interpretation. Furthermore, each ridge comprising C1 separates each adjacent truncated polygon pyramid 220 having planar edges (see figure 2C, which is the cross-section of figure 2A along line I-I) which meet the ridge at element C1, and therefore, are “directly adjacent to the ridge”. Therefore, Applicant’s argument is not persuasive. Regarding ii.), in response to applicant’s argument that there is no teaching, suggestion, or motivation to combine the references, the examiner recognizes that obviousness may be established by combining or modifying the teachings of the prior art to produce the claimed invention where there is some teaching, suggestion, or motivation to do so found either in the references themselves or in the knowledge generally available to one of ordinary skill in the art. See In re Fine, 837 F.2d 1071, 5 USPQ2d 1596 (Fed. Cir. 1988), In re Jones, 958 F.2d 347, 21 USPQ2d 1941 (Fed. Cir. 1992), and KSR International Co. v. Teleflex, Inc., 550 U.S. 398, 82 USPQ2d 1385 (2007). In this case, although Applicant correctly notes that Ahn teaches flat ridges between adjacent recesses, Examiner notes that the obviousness rejection was applied based on the teaching of Ahn directed to the pitch dimensions of the recesses in relation to the width dimension occupied by the adjacent ridge (regardless of the shape of the top of the ridge). Since Chung does not expressly disclose the width of C1, and even more particularly, in relationship to the pitch of the recesses, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to incorporate the teachings of Ahn with respect to the relationship between the pitch of the recesses and the width of the ridge, with the motivation of preventing generation of stain phenomenon in diffusion sheet optics (as previously presented). Therefore, Applicant’s arguments are not persuasive. Regarding iii.), in response to applicant’s argument that there is no teaching, suggestion, or motivation to combine the references, the examiner recognizes that obviousness may be established by combining or modifying the teachings of the prior art to produce the claimed invention where there is some teaching, suggestion, or motivation to do so found either in the references themselves or in the knowledge generally available to one of ordinary skill in the art. See In re Fine, 837 F.2d 1071, 5 USPQ2d 1596 (Fed. Cir. 1988), In re Jones, 958 F.2d 347, 21 USPQ2d 1941 (Fed. Cir. 1992), and KSR International Co. v. Teleflex, Inc., 550 U.S. 398, 82 USPQ2d 1385 (2007). In this case, the obviousness rejection was made with regard to the teachings of Takizawa regarding the height of ridges between adjacent recesses, regardless of the shape of the recesses. Therefore, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to incorporate the teachings of Takizawa regarding the height different between the straight line and the ridge to be applied to height difference of Chung, for the motivation of suppressing a deterioration of a light collecting function even when it is rubbed with another member to obtain high luminance, as previously presented. Therefore Applicant’s arguments are not persuasive. Claim Rejections - 35 USC § 103 The text of those sections of Title 35, U.S. Code not included in this action can be found in a prior Office action. Claim(s) 1-17 are rejected under 35 U.S.C. 103 as being unpatentable over Chuang et al. (US 2009/0316430) in view of Ahn (US 2010/0124047), and in further view of Takizawa (JP2010160438A; translation previously submitted). Regarding claim 1, Chuang discloses a light diffusion sheet (see figures 2A-2E, for instance) comprising: at least in its first surface (P1), a plurality of recesses (220) formed in a substantially inverted polygon pyramid or in a substantially inverted truncated polygon pyramid ([0044]), wherein: a ridge (starting at C1, and continuing in the dotted lines of Fig. 2A) parting the plurality of recesses has a recessed shape between intersections of the ridge, wherein each of the plurality of recesses (220) is directly adjacent to the ridge (C1, which is comprised within 210, see Response to Arguments, above). However, Chuang does not expressly disclose with respect to a straight line connecting the intersections a ratio Wr/P is 0.3 or less, where P is an arrangement pitch of the plurality of recesses and Wr is a dimension occupied by a curved portion at a top portion of the ridge in an arrangement direction of the plurality of recesses; and a maximum height difference between the straight line and the ridge is 1 μm or more and 10 μm or less. Ahn discloses a light diffusion sheet (see figures 1-5, for instance), with respect to a straight line (along which width d1 occupies the ridge) connecting the intersections a ratio Wr/P is 0.3 or less (if d1 = 10µm and p1 > 50µm, then Wr/P < 0.2; [0055]), where P is an arrangement pitch (p1) of the plurality of recesses and Wr is a dimension (d1) occupied by a curved portion at a top portion of the ridge in an arrangement direction of the plurality of recesses. It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to use the straight line ridge dimensions of Ahn in the diffusion sheet of Chuang. The motivation for doing so would have been to prevent the generation of stain phenomenon in the diffusion sheet optics, as taught by Ahn ([0050]). Takizawa discloses a light diffusion sheet (see figures 6-7, for instance), a maximum height difference between the straight line (top of 31, represented by height h1) and the ridge (top of 43, represented by h2) is 1 μm or more and 10 μm or less (since h1 = 18µm and h2 = 12µm in the second example, see paragraph 8 of page 8). It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to use the height difference dimensions of Takizawa in the diffusion sheet of Chuang. The motivation for doing so would have been to suppress a deterioration of a light collecting function even when it is rubbed with another member to obtain high luminance, as taught by Takizawa (see Abstract). Regarding claim 2, Chuang in view of Ahn and in further view of Takizawa discloses the light diffusion sheet of claim 1, wherein the maximum height difference is 1.5 μm or more and 7 μm or less (Takizawa, paragraph 8, page 8). Regarding claim 3, Chuang in view of Ahn and in further view of Takizawa discloses the light diffusion sheet of claim 2, wherein the maximum height difference is 2.5 μm or more and 5 μm or less (see paragraph 9 of page 8 of Takizawa). Regarding claim 4, Chuang in view of Ahn and in further view of Takizawa discloses the light diffusion sheet of claim 1, wherein the ratio Wr/P is 0.2 or less (Ahn [0055]). Regarding claim 5, Chuang in view of Ahn and in further view of Takizawa discloses the light diffusion sheet according to claim 4, wherein the ratio Wr/P is 0.1 or less (Ahn [0055]; since p1 ranges from 50 to 100 µm). Regarding claim 6, Chuang in view of Ahn and in further view of Takizawa discloses the light diffusion sheet of claim 1, wherein: the arrangement pitch P is 50 μm or more and 500 μm or less (Ahn [0055]); and an angle formed between a wall surface of each of the plurality of recesses and a sheet surface of the light diffusion sheet is 40 degrees or more and 65 degrees or less (see Ahn claim 2). Regarding claim 7, Chuang in view of Ahn and in further view of Takizawa discloses the light diffusion sheet of claim 1, wherein the ridge between the intersections is recessed in a substantially parabolic shape, a substantially arc shape, a substantially triangular shape, or a substantially trapezoidal shape (see Chuang fig. 2B). Regarding claim 8, Chuang in view of Ahn and in further view of Takizawa discloses the light diffusion sheet of claim 1, wherein: the plurality of recesses (220) are each formed in a substantially inverted quadrangular pyramid or a substantially inverted truncated quadrangular pyramid shape ([0044]); the ridge extends in a first direction and a second direction; the maximum height difference is an average of a maximum height difference (dx) between the straight line and the ridge in the first direction and a maximum height difference (dy) between the straight line and the ridge in the second direction; the arrangement pitch P is an average of an arrangement pitch (Px) of the plurality of recesses in the first direction and an arrangement pitch (Py) of the plurality of recesses in the second direction; and the dimension Wr is an average of a dimension (Wrx) occupied by the curved portion at the top portion of the ridge in the first direction and a dimension (Wry) occupied by the curved portion at the top portion of the ridge in the second direction (see figures 2A-2B). Regarding claim 9, Chuang in view of Ahn and in further view of Takizawa discloses the light diffusion sheet of claim 1, wherein; the plurality of recesses are provided only in the first surface (S1); and the second surface (S2) is a matte surface. Regarding claim 10, Chuang in view of Ahn and in further view of Takizawa discloses a backlight unit (see Abstract) built in a liquid crystal display device and leading light emitted from light sources toward a display screen, wherein the backlight unit comprises: the light diffusion sheet of claim 1 provided between the display screen and the light sources ([0070]). Regarding claim 11, Chuang in view of Ahn and in further view of Takizawa discloses the backlight unit of claim 10, wherein the light sources are arranged on a reflective sheet provided on an opposite side of the display screen as seen from the light diffusion sheet ([0070]). Regarding claim 12, Chuang in view of Ahn and in further view of Takizawa discloses the backlight unit of claim 10, wherein the light diffusion sheet includes a plurality of light diffusion sheets layered and arranged between the display screen and the light sources ([0070]). Regarding claim 13, Chuang in view of Ahn and in further view of Takizawa discloses the backlight unit of claims 12, wherein the light diffusion sheet includes three or more light diffusion sheets layered and arranged between the display screen and the light sources ([0070]). Regarding claim 14, Chuang in view of Ahn and in further view of Takizawa discloses the backlight unit of claim 13, wherein: of the three or more light diffusion sheets, the light diffusion sheet closest to the display screen contains a diffusion agent, and the other light diffusion sheets contain substantially no diffusion agent ([0070]). Regarding claim 15, Chuang in view of Ahn and in further view of Takizawa discloses a liquid crystal display device, comprising: the backlight unit of claim 10; and a liquid crystal display panel ([0070]). Regarding claim 16, Chuang in view of Ahn and in further view of Takizawa discloses an information apparatus, comprising the liquid crystal display device of claim 15 ([0070]). Regarding claim 17, Chuang in view of Ahn and in further view of Takizawa discloses a method of manufacturing the light diffusion sheet of claim 1, the method comprising the step of: extrusion-molding of the light diffusion sheet at a line speed of 10 m/min or more and 30 m/min or less, with a compression line pressure of 100 kgf/cm or more and 500 kgf/cm or less ([0070]; see figures 2A-2B, for instance). Conclusion Any inquiry concerning this communication or earlier communications from the examiner should be directed to NATHANAEL R BRIGGS whose telephone number is (571)272-8992. The examiner can normally be reached Monday - Friday, 9:00 am - 5:00 pm. 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, Jennifer Carruth can be reached at (571)-272-9791. 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. /NATHANAEL R BRIGGS/Primary Examiner, Art Unit 2871 2/2/2026
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Prosecution Timeline

May 31, 2023
Application Filed
Jul 09, 2025
Non-Final Rejection — §103, §DP
Oct 02, 2025
Response Filed
Oct 30, 2025
Final Rejection — §103, §DP
Jan 08, 2026
Request for Continued Examination
Jan 24, 2026
Response after Non-Final Action
Feb 02, 2026
Non-Final Rejection — §103, §DP (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

3-4
Expected OA Rounds
76%
Grant Probability
88%
With Interview (+11.5%)
2y 9m
Median Time to Grant
High
PTA Risk
Based on 1067 resolved cases by this examiner. Grant probability derived from career allow rate.

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