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 .
Continued Examination Under 37 CFR 1.114
A request for continued examination under 37 CFR 1.114, including the fee set forth in 37 CFR 1.17(e), was filed in this application after final rejection. Since this application is eligible for continued examination under 37 CFR 1.114, and the fee set forth in 37 CFR 1.17(e) has been timely paid, the finality of the previous Office action has been withdrawn pursuant to 37 CFR 1.114. Applicant's submission filed on November 21, 2025 has been entered.
This Office action is in response to the amendment filed November 21, 2025, which amends claims 1, 9, 10, 14, and 20, cancels claim 16, and adds claims 21. Claims 1-15 and 17-21 are pending.
Response to Amendment
Applicant’s amendment of the claims, filed November 21, 2025, caused the withdrawal of the rejection of claims 1-20 under 35 U.S.C. 103 as being unpatentable over Hatakeyama et al. (US 2015/0236274) in view of Tanimoto et al. (US 2016/0197282) and Hatakeyama et al. (WO 2020/040298) as set forth in the Office action mailed August 26, 2025.
Response to Arguments
Applicant’s arguments with respect to claim(s) 1-15 and 17-21 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.
The factual inquiries for establishing a background for determining obviousness under 35 U.S.C. 103 are summarized as follows:
1. Determining the scope and contents of the prior art.
2. Ascertaining the differences between the prior art and the claims at issue.
3. Resolving the level of ordinary skill in the pertinent art.
4. Considering objective evidence present in the application indicating obviousness or nonobviousness.
Claim(s) 1-15 and 17-21 is/are rejected under 35 U.S.C. 103 as being unpatentable over Hatakeyama et al. (US 2015/0236274) (hereafter “Hatakeyama”) in view of Tanimoto et al. (US 2016/0197282) (hereafter “Tanimoto”), Forrest et al. (US 2015/00349286) (hereafter “Forrest”), and Hatakeyama et al. (WO 2020/040298) (hereafter “Hatakeyama 2020”), where a machine translation is used as the English equivalent.
Regarding claims 1-15 and 17-21, Hatakeyama teaches an electroluminescent device comprising an anode, a hole transporting layer, a light emitting layer, an electron transporting layer, and a cathode (paragraphs [0582]-[0585]). Hatakeyama teaches that the light emitting layer comprises a host material and a dopant (paragraph [0583]). Hatakeyama teaches that the dopant can have the following structure,
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(paragraphs [0034] and [0583]).
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is a compound that applicant’s teaches that corresponds to applicant’s claimed second compound and therefore, meets the applicant’s claimed energy limitations. Hatakeyama teaches that the light emitting layer can be used in a consumer product, such as a flat panel display (paragraphs [0265] and [0266]).
Hatakeyama does not where the light emitting layer comprises a second host material and does not teach the energy requirements of the host materials.
Tanimoto teaches that one can achieve high light emission efficiency by incorporating a TADF compound as an assisting dopant in the layer emitting layer (the material is acting as a third component) (paragraph [0010]). Tanimoto teaches that the T1 and S1 values of the host material or materials need to be higher than the T1 and S1 values of both the dopant and the assisting dopant (Fig. 1B). Fig. 1A also shows that the energy difference between the T1 and S1 of the TADF or assisting dopant needs to be smaller than the emitting dopant. Tanimoto teaches that the host material is a carbazole compound and that the light emitting layer can comprise more than one host material (paragraphs [0283]-[0290]).
Forrest teaches that one can increase the lifetime of an electroluminescent device by adding a TADF sensitizer to a light emitting layer composed of a blue fluorescent dopant (paragraph [0048]).
Hatakeyama 2020 teaches TADF compounds that can be used in electroluminescent devices (pages ). Hatakeyama 2020 teaches that the TADF compounds can have the following structure,
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,
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,
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, or
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are a few examples, which are the same as applicant’s claimed first compound (pages 80-95 and 157-162). Hatakeyama 2020 teaches that these compounds have a very small energy difference between the T1 and S1 (page 162 the Table).
It would have been obvious one of ordinary skill in the art at the time the invention was effectively filed to modify to device of Hatakeyama so the device comprises a TADF material, such as the compound taught by Hatakeyama 2020, as a sensitizer, as taught by Forrest, and one or two host materials, as taught by Tanimoto, where the T1 and S1 of each host material is higher than the T1 and S1 of the dopant and TADF material, as taught by Tanimoto. The motivation, as taught by Tanimoto, would have been to improve emission efficiency of the device. The motivation, as taught by Forrest, to add the TADF sensitizer would have been to improve the lifetime of the device.
The combination would lead to a device that comprises a dopant and TADF material that meets the applicant’s claimed second and first compounds and would meet the applicant’s claimed energy limitations.
Conclusion
Any inquiry concerning this communication or earlier communications from the examiner should be directed to ANDREW K BOHATY whose telephone number is (571)270-1148. The examiner can normally be reached Monday-Friday 7am-4pm.
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If attempts to reach the examiner by telephone are unsuccessful, the examiner’s supervisor, Curtis Mayes can be reached at (571)272-1234. The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300.
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/ANDREW K BOHATY/Primary Examiner, Art Unit 1759