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 .
DETAILED ACTION
Response to Arguments
Applicants arguments and amendments, filed on 6/17/26, have been fully considered but they do not confer patentability on all of the instantly filed claims. Applicants have amended independent claim 1 to require that the mixed layer has a non-uniform distribution. This necessarily means that the prior art rejections which teach solution deposition would can no longer be relied upon as solution deposition would only be reasonably expected to from uniform distribution. As such, the prior art rejection to Dubey et al. (Organic Electronics 2019, 69, 232-240) has been withdrawn. The prior art rejection to Adamovich et al. (US 2012/0319146) is also withdrawn for the same reasons as Dubey et al. The prior art rejection to Fleetham et al. has been modified to exclude Fleetham et al. as an anticipatory reference. However, Fleetham et al. is relied upon in an obviousness type rejection as described below.
The claim interpretation regarding the product-by-process limitations in claim 1 as described in the previous Office action are wholly maintained. Additionally, the claim interpretation regarding ‘concentration profile of the dopant composition’ is also maintained with the understanding that the concentration profile as instantly claimed must be non-uniform.
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 of this title, 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.
This application currently names joint inventors. In considering patentability of the claims the examiner presumes that the subject matter of the various claims was commonly owned as of the effective filing date of the claimed invention(s) absent any evidence to the contrary. Applicant is advised of the obligation under 37 CFR 1.56 to point out the inventor and effective filing dates of each claim that was not commonly owned as of the effective filing date of the later invention in order for the examiner to consider the applicability of 35 U.S.C. 102(b)(2)(C) for any potential 35 U.S.C. 102(a)(2) prior art against the later invention.
Claims 1-4 and 7-11 are rejected under 35 U.S.C. 103 as obvious over Fleetham et al. (US 2022/0246851), optionally in view of Forrest et al. (US 2016/0293864).
Claim 1: Fleetham et al. teaches organic light emitting devices comprising a mixed layer which is an emission layer. Fleetham et al. exemplifies a light emitting device where the emission layer is comprised of a hole-transporting host (compound 3), an electron-transporting host (compound 4), a sensitizer (phosphor 1, shown as sensitizer 1), and a dopant (DABNA-D21). The sensitizer serves as a first dopant and is a platinum-group containing dopant and the DABNA-D21 serves as a thermally activated delayed fluorescent (TADF) second dopant which does not comprise a transition metal and comprises a cyclic group including a boron and a nitrogen atom as ring forming atoms.
While Fleetham et al. does not explicitly teach that the sensitizer and TADF dopant have a concentration profile with respect to a thickness of the mixed layer/emission layer, Fleetham et al. is clearly aware of the challenges of vapor depositing two different materials. In paragraphs 0118 and 0119 Fleetham et al. teaches that when co-evaporating 3 or 4 source materials, maintaining control over the deposition rates of each material becomes costly and difficult (paragraph 0118). Fleetham et al. teaches that co-evaporation must be stable so that the composition of the evaporated film remains constant during the vacuum deposition process (paragraph 0119). Fleetham et al. requires that the difference in evaporation temperature between the sensitizer and dopant are preferably less than 20 °C (paragraph 0125). Fleetham et al. further teaches that the sensitizer has a concentration C1 in the mixture, the TADF material has a concentration C2 in the mixture, and the absolute value of (C1-C2)/C1 is less than 3% (paragraph 0126), and that the mixture of sensitizer and TADF material have a mass loss rate within 0.97:1 to 1.03:1 (paragraph 0128).
All of these requirements are understood by a person having ordinary skill in the art to allow for an the sensitizer and dopant to be present in the same relative amounts throughout the thickness of the emission layer. In other words, the sensitizer and TADF dopant has a concentration profile with respect to the thickness of the mixed layer according to Applicants definition. It would be expected that the concentration profile of the sensitizer material and the TADF material would be at least substantially the same at any point in within the emission layer given the parameters which must be adhered to according to Fleetham et al.
Alternatively, should this not be the case, a person having ordinary skill in the art would have found it obvious to optimize the various parameters taught by Fleetham et al. so as to ensure that the vapor-deposited dopant mixture has a concentration profile with respect to the thickness of the mixed layer, the motivation to do so being rooted in the teachings of Fleetham et al. as described in paragraphs 0117-0137.
Additionally, Fleetham et al. teaches that the mixture can be present in graded concentrations through the thickness of the layer such, including linear and sinusoidal (paragraph 0067). While Fleetham et al. does not exemplify such non-uniform dopant distribution, a person having ordinary skill in the art would have found it obvious to have employed a non-uniform sensitizer and dopant distribution given the teachings of Forrest et al. Fleetham et al. and Forrest et al. are combinable as they are both from the same field of organic electroluminescent devices. Forrest et al. teaches that a linear graded distribution of dopants afford higher external quantum efficiencies, than analogous uniformly distributed dopants (see Fig. 8D). Linear grading of the dopant distributes the charge-trapping and recombination sites across the entire thickness of the emission layer, which broadens the exciton formation zone, which lowers efficiency roll-off. For these reasons, it would have been obvious to have prepared an emission layer comprising a sensitizer, dopant, and host, where the sensitizer and dopant are non-uniformly distributed throughout the emission layer, thereby satisfying this limitation of claim 1.
Claim 2: The host materials employed in the device examples comprises a combination of a hole-transporting compound and an electron-transporting compound, as described in claim 1 above, thereby satisfying claim 2.
Claim 3: The first dopant/sensitizer comprises platinum, thereby satisfying claim 3.
Claims 4 and 7: Claims 4 and 7 includes limitations which further limit the process steps in product-by-process claim 1. As stated above, these limitations do not need to be specifically met in the case of product-by-process claims if it can be shown that the final product of the claim is also taught in the art.
Claims 8 and 9: The second dopant (TADF dopant) does not comprise a transition metal and comprises a cyclic group including a boron and a nitrogen atom as ring forming atoms, thereby satisfying claims 8 and 9.
Claim 10: The first dopant in the device examples of Fleetham et al. is a sensitizer and the second dopant is an emitter, thereby satisfying claim 10.
Claim 11: Both the sensitizer (sensitizer 1) and the fluorescent emitter (DABNA-D21) as exemplified by Fleetham et al. emit blue light which satisfies the limitations of claim 11.
Allowable Subject Matter
Claims 5 and 6 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. The devices taught by Fleetham et al. do not include embodiments where the first and second dopant are both compounds which comprise a transition metal as required by claims 5 and 6.
Conclusion
Applicant's amendment necessitated the new grounds 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 ROBERT S LOEWE whose telephone number is (571)270-3298. The examiner can normally be reached on Monday-Friday from 8 AM to 5 PM.
If attempts to reach the examiner by telephone are unsuccessful, the examiner’s supervisor, Randy Gulakowski, can be reached at telephone number 571-272-1302. The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300.
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/Robert S Loewe/Primary Examiner, Art Unit 1766
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