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
Claim Interpretation
It is understood from Applicants specification that the T1onset, the T1max, and the DEst are calculated from thin films of the first host and first dopant at 4 degrees Kelvin as described in paragraph 0427 of Applicants pre-grant publication US 2024/0023356. The T1(H1)onset, the T1(H1)max, the T1(D1)onset, and the T1(D1)max as recited in independent claim 1 is therefore understood to refer to thin films measured at 4 degrees Kelvin.
Claim Rejections - 35 USC § 112
The following is a quotation of 35 U.S.C. 112(b):
(B) CONCLUSION.—The specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the inventor or a joint inventor regards as the invention.
Claims 1-20 are rejected under 35 U.S.C. 112(b) as being indefinite for failing to particularly point out and distinctly claim the subject matter which the inventor or a joint inventor regards as the invention. Independent claim 1 is drawn to an organic light-emitting device comprising an emission layer comprising a first host, a second host, a first dopant, and a second dopant. Claim 1 recites that the second dopant is “a fluorescent dopant or a delayed fluorescent dopant” and further requires the second dopant to satisfy Equation 3-3, which restricts its singlet-triplet energy gap to 0.3 eV or less. However, a singlet-triplet energy gap of 0.3 eV or less is understood in the art to characterize delayed fluorescent dopants specifically. Consequently, claim 1 is indefinite because it is unclear whether the second dopant may be a conventional fluorescent dopant or if it is functionally restricted to a delayed fluorescent dopant. Claims 2-20 are included in this rejection as they are dependent on claim 1.
Additionally, claim 7 is rejected under 35 U.S.C. 112(b) for similar reasons. Claim 7 recites that the first dopant is “a fluorescent dopant or a delayed fluorescent dopant” satisfying Equation 3-2, which restricts its singlet-triplet energy gap to 0.3 eV or less. It is likewise unclear whether the first dopant may be a conventional fluorescent dopant or is limited to a delayed fluorescent dopant.
The following is a quotation of 35 U.S.C. 112(d):
(d) REFERENCE IN DEPENDENT FORMS.—Subject to subsection (e), a claim in dependent form shall contain a reference to a claim previously set forth and then specify a further limitation of the subject matter claimed. A claim in dependent form shall be construed to incorporate by reference all the limitations of the claim to which it refers.
Claim 16 is rejected under 35 U.S.C. 112(d) as being of improper dependent form for failing to further limit the subject matter of the claim upon which it depends, or for failing to include all the limitations of the claim upon which it depends. Independent claim 1 requires that the second dopant, which is claimed to be a fluorescent dopant or a delayed fluorescent dopant, satisfies Equation 3-3. Equation 3-3 recites that the singlet-triplet energy gap of the second dopant is less than or equal to 0.3 eV. This is a conventional way in the art to refer to a thermally activated delayed fluorescent (TADF) dopant, as room temperature thermal energy (kBT) is about 0.025-0.3 eV. Having a fluorescent dopant which can be promoted from a singlet energy level to a triplet energy level at room temperature is what allows for TADF dopants to theoretically have 100% photoluminescence quantum yield (FPL). However, claim 16, which is directly dependent from claim 1 recites that the fluorescent dopant is a compound represented by Formula 501 or selected from one of the 7 specific compounds shown. The seven compounds are not TADF dopants but rather conventional fluorescent dopants which would be expected to have a singlet-triplet energy gap slightly larger, or in some cases, quite a bit larger than the 0.3 eV value required by claim 1. As one example, C545T is a known dopant having a singlet-triplet energy gap of 1.03 eV, which is well outside the ≤ 0.3 eV requirement of claim 1. Applicant may cancel the claim, amend the claim to place the claim in proper dependent form, rewrite the claim in independent form, or present a sufficient showing that the dependent claim complies with the statutory requirements.
Comment on Patentability
While all claims stand rejected, the claims are not subject to any prior art rejections. This application is a continuation of application 16/886,441, which is now U.S. Pat. 11,864,400. The parent application is drawn to an organic light-emitting device comprising an emission layer which comprises a first host and a first dopant which each satisfy Equations 1-1 and 1-2. The instant application builds on the parent application in that the emission layer further comprises a second host and a second dopant, where the first host comprises a hole transport moiety and the second host comprises an electron transport moiety, and the second dopant satisfies Equation 3-3.
While a dual host systems have been known in the prior art for some time, including those which are capable of forming an exciplex due to the hole transporting and electron transporting abilities of each respective host material, the instant application has a filing date of 5/28/20 and a foreign priority date of 5/31/19. At the time of Applicants filing date only a handful of organic electroluminescent devices comprising an emission layer comprising a first host, a second host, a first dopant, and a second dopant were known. One example is Kim et al. (US 2017/0346029). Kim et al. teaches a light-emitting device comprising an emission layer which comprises a hole transporting host and an electron transporting host, and wherein the two host materials form an exciplex (abstract). The emission layer further comprises a fluorescent dopant, and may also include a phosphorescent dopant as taught and shown in Fig. 4. However, it cannot be stated with any degree of certainty whether the first host materials and the first dopant materials taught by Kim et al. would satisfy Equations 1-1 and 1-2 as recited in claim 1.
Wei et al. (CN-109817818) represents another prior art reference which is directed to organic electroluminescent devices comprising an emission layer, wherein the emission layer comprises a hole-transporting material, an electron transporting material, wherein the hole-transporting and electron-transporting materials form an exciplex, a delayed fluorescent dopant (first dopant) and a delayed fluorescent sensitizer, which is a co-dopant, or second dopant. Like Kim et al. above, it cannot be stated with any degree of certainty that the first host materials and the first dopant materials taught by Wei et al. would satisfy Equations 1-1 and 1-2 as recited in claim 1.
Fleetham et al. (US 2022/0158096) teaches organic electroluminescent devices comprising a hole transporting host (compound 3) an electron transporting host (compound 4), a phosphorescent sensitizer (dopant, phosphor 1), and an acceptor compound which is a thermally activated delayed fluorescent dopant (paragraph 0177). However, Fleetham et al. does not qualify as prior art.
Kim et al. (US 2020/0395547) is closely related to Applicants invention and has the same assignee as the instant application. However, Kim et al. does not qualify as prior art as the common ownership exception applies.
Relevant Art Cited
Additional prior art documents which are relevant to Applicants invention can be found on the attached PTO-892 form.
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
