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 Amendment
The amendment filed 1/2/2026 has been entered.
The rejections under 35 U.S.C. 112(b) presented in the Office Action mailed 10/8/2025 have been withdrawn based on the amendment filed 1/2/2026.
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.
Claims 1, 6-8, 12, and 13 are rejected under 35 U.S.C. 103 as being unpatentable over Hara et al. (US 2003/0227768) in view of Choi et al. (US 2005/0099823).
With regards to Claim 1, Hara et al. discloses a backlight comprising: a light source [10,30] (see paragraph 26 and Figure 1); a light guide plate [50] (see paragraph 26 and Figure 1) including an end face that serves as an incident surface of light from the light source (see Figure 1), and a first prism surface that serves as an emission surface of the light, the first prism surface including first grooves [51], the first grooves [51] being adjacent in a first direction and extending in a second direction, the first direction and the second direction being perpendicular (see paragraph 30 and Figure 1); and a prism sheet [62] overlapping with the light guide plate [50], the prism sheet [62] including a second prism surface directly facing the first prism surface, and a flat surface on a side opposite to the second prism surface , the second prism surface including second grooves, the second grooves being adjacent in the first direction and extending in the second direction (see paragraph 29 and Figure 1), wherein, in light distribution characteristics on a first vertical plane spreading in the first direction and a vertical direction that is perpendicular to both the first direction and the second direction, peaks of luminous intensity are observed in two directions excluding the vertical direction (see paragraph 29 and Figure 1), each of the first grooves [51] includes a pair of first inclined surfaces [513,515] (see paragraph 33 and Figure 2B), each of the second grooves includes a pair of second inclined surfaces (see paragraphs 29 and 30 and Figure 1; each of the first grooves and second grooves is a triangular prism shape, which substantially includes a pair of inclined surfaces, respectively), each of the first grooves and the second grooves is a V-groove (see paragraphs 29 and 33 and Figures 1 and 2B).
Hara et al. does not disclose the pair of first inclined surfaces are of plane-symmetry, the pair of second inclined surfaces are of plane-symmetry, and a reference plane of the plane-symmetry is a second vertical plane spreading in the vertical direction and the second direction.
Choi et al. teaches the pair of first inclined surfaces (comprising the surfaces of portions [220], see paragraph 19 and Figure 2A) are of plane-symmetry, the pair of second inclined surfaces are of plane-symmetry, and a reference plane of the plane-symmetry is a second vertical plane spreading in the vertical direction and the second direction (see paragraph 19 and Figure 2A).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify the pair of first included surfaces and the pair of second included surfaces of Hara et al. such that the pair of first inclined surfaces are of plane-symmetry, the pair of second inclined surfaces are of plane-symmetry, and a reference plane of the plane-symmetry is a second vertical plane spreading in the vertical direction and the second direction, as taught by Choi et al. One would have been motivated to do so in order to maintain a path of the diffused light constantly (see Choi et al. paragraph 19).
Hara et al. and Choi et al. do not explicitly disclose a first external angle between the pair of first inclined surfaces is equal to or greater than a second external angle between the pair of second inclined surfaces. However, Hara et al. does disclose the first external angle falls within the range of 65 degrees and 145 degrees (see Hara et al. paragraph 34 and Figure 2B; since the angle [θ1] is between 10 degrees and 50 degrees and the angle [θ2] is between 25 degrees to 65 degrees, a first external angle is disclosed in the range between 65 degrees and 145 degrees) and using a second groove that is formed of triangular prisms which are capable of refracting the light incident thereon so that light is emitted from the flat surface of the prism sheet at an angle of about 45 degrees in a direction towards a BEF (see Hara et al. paragraph 29 and Figure 1). Therefore, one of ordinary skill in the art would be able to utilize first grooves and second grooves such that first external angle between the pair of first inclined surfaces is equal to or greater than a second external angle between the pair of second inclined surfaces in order to substantially direct the light towards a BEF. It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify the first external angle and second external angle of Hara et al. and Choi et al. such that a first external angle between the pair of first inclined surfaces is equal to or greater than a second external angle between the pair of second inclined surfaces. One would have been motivated to do so in order to direct the light towards a BEF (see Hara et al. paragraph 29).
With regards to Claim 6, Hara et al. and Choi et al. disclose the backlight as discussed above with regards to Claim 5.
Hara et al. further discloses the first external angle is 90 degrees (see paragraph 34 and Figure 2B; the first external angle falls within the range disclosed by Hara et al. since the angle [θ1] is between 10 degrees and 50 degrees and the angle [θ2] is between 25 degrees to 65 degrees, which creates an external angle range between 65 degrees and 145 degrees).
Hara et al. does not disclose the second external angle is 120 degrees. However, Hara et al. does disclose using a second groove that is formed of triangular prisms which are capable of refracting the light incident thereon so that light is emitted from the flat surface of the prism sheet at an angle of about 45 degrees in a direction towards a BEF (see Hara et al. paragraph 29 and Figure 1). Therefore, one of ordinary skill in the art would be able to adjust an angle of the second external angle to be 120 degrees in order to provide a light output at an intended angle for directing light toward a BEF. It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify the second external angle of Hara et al. to be 120 degrees. One would have been motivated to do so in order to provide a light output at an intended angle for directing light toward a BEF (see Hara et al. paragraph 29).
With regards to Claim 7, Hara et al. and Choi et al. disclose the backlight as discussed above with regards to Claim 1.
Hara et al. further discloses the light source [10,30] is adjacent to the light guide plate [50] in the second direction (see Figure 1).
With regards to Claim 8, Hara et al. and Choi et al. disclose the backlight as discussed above with regards to Claim 7.
Hara et al. further discloses the light source includes a pair of light sources [10,30], and the pair of light sources [10,30] are adjacent to both sides of the light guide plate [50] in the second direction (see paragraph 26 and Figure 1).
With regards to Claim 12, Hara et al. and Choi et al. discloses the backlight as discussed above with regards to Claim 1.
Hara et al. further discloses angles in the two directions (comprising the x-direction and the y-direction) from the second vertical plane are an angle of +30 degrees or more and an angle of -30 degrees or less (see paragraph 27 and Figure 1; angles relative the two directions are substantially +30 degrees or more and an angle of -30 degrees or less).
With regards to Claim 13, Hara et al. and Choi et al. disclose a display device comprising: the backlight according to Claim 1 (see the above discussion of the disclosure of Hara et al. as pertains to the limitations of Claim 1).
Hara et al. further discloses a liquid crystal display panel [66] facing the backlight (see paragraph 24 and Figure 1).
Claims 9 and 10 are rejected under 35 U.S.C. 103 as being unpatentable over Hara et al. (US 2003/0227768), as modified by Choi et al. (US 2005/0099823), further in view of Chen et al. (TW 1819590; please see attached translation for reference to pages).
With regards to Claim 9, Hara et al. and Choi et al. disclose the backlight as discussed above with regards to Claim 1.
Hara et al. further discloses an optical sheet [64], the optical sheet [64] including a bottom surface directly facing the flat surface of the prism sheet [62] (see paragraph 54 and Figure 1).
Hara et al. does not disclose the optical sheet including a third prism surface on a side opposite to the bottom surface, the third prism surface including third grooves, the third grooves extending in the first direction and being adjacent in the second direction.
Chen et al. teaches an optical sheet [150] (see middle of page 4 and Figure 7), the optical sheet [150] including a bottom surface directly facing the flat surface of the prism sheet [140] (see middle of page 4 and Figure 7), the optical sheet [150] including a third prism surface on a side opposite to the bottom surface (see bottom of page 6 and Figure 7), the third prism surface including third grooves, the third grooves extending in the first direction and being adjacent in the second direction (see middle of page 6 and Figure 7).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify the optical sheet of Hara et al. and Choi et al. to include a third prism surface on a side opposite to the bottom surface, the third prism surface including third grooves, the third grooves extending in the first direction and being adjacent in the second direction, as taught by Chen et al. One would have been motivated to do so in order to provide a good light collimation effect (Chen et al. middle of page 6).
With regards to Claim 10, Hara et al., Choi et al., and Chen et al. disclose the backlight as discussed above with regards to Claim 9.
Hara et al. does not disclose a dual brightness enhancement film directly facing the third prism surface of the optical sheet.
Chen et al. teaches a dual brightness enhancement film [170] directly facing the third prism surface of the optical sheet [150] (see bottom of page 7 and Figure 7).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify the backlight of Hara et al. to include a dual brightness enhancement film directly facing the third prism surface of the optical sheet, as taught by Chen et al. One would have been motivated to do so in order to increase a brightness of the backlight.
Claim 11 is rejected under 35 U.S.C. 103 as being unpatentable over Hara et al. (US 2003/0227768), as modified by Choi et al. (US 2005/0099823), further in view of Koike et al. (WO 2013122156; please see attached translation for reference to pages).
With regards to Claim 11, Hara et al. and Choi et al. disclose the backlight as discussed above with regards to Claim 1.
Hara et al. further discloses the first prism surface of the light guide plate [50] includes a ridge portion (comprising a ridge at the peak of portion [51], see Figures 1 and 2B) at a peak between an adjacent pair of the first grooves (see Figures 1 and 2B).
Hara et al. does not disclose the ridge portion is a rounded ridge portion at the peak.
Koike et al. teaches the first prism surface of the light guide plate [22] includes a rounded ridge portion at a peak between an adjacent pair of the first grooves (see bottom of page 6 and top of page 7 and Figure 5a).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify the ridge portion of Hara et al. to be a rounded ridge portion at the peak, as taught by Koike et al. One would have been motivated to do so in order to provide a desired light output effect (see Koike et al. middle of page 7).
Response to Arguments
Applicant's arguments filed 1/2/2026 have been fully considered but they are not persuasive. The examiner responds below.
With regards to the applicant’s argument that Hara et al. does not disclose each feature of amended Claim 1 and Choi et al. does not disclose "each of the first grooves includes a pair of first inclined surfaces, each of the second grooves includes a pair of second inclined surfaces, the pair of first inclined surfaces are of plane-symmetry, the pair of second inclined surfaces are of plane-symmetry, a reference plane of the plane-symmetry is a second vertical plane spreading in the vertical direction and the second direction, each of the first grooves and the second grooves is a V-groove, and a first external angle between the pair of first inclined surfaces is equal to or greater than a second external angle between the pair of second inclined surfaces", the examiner directs the applicant to the above rejection of Claim 1 over Hara et al. in view of Choi et al., and notes that the combination of the Hara et al. reference with the Choi et al. reference does teach, disclose, or suggest the limitations of amended Claim 1.
Conclusion
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 ERIN KRYUKOVA whose telephone number is (571)272-3761. The examiner can normally be reached M-F 9a.m. - 4p.m.
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, Jong-Suk (James) Lee can be reached at 5712727044. 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.
/ERIN KRYUKOVA/Primary Examiner, Art Unit 2875