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 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 1-11 and 15-18 are rejected under 35 U.S.C. 103 as being unpatentable over Forrest et al. (US 2017/0104172) in view of Lee et al. (Journal of Information Display 2014, 15, 139-144) as evidenced by technical data sheets from Ossila.
Claim 1: Forrest et al. teaches organic light emitting diodes which include mixed blocking layers. The mixed blocking layer has a triplet exciton energy greater than that of the emissive material (paragraph 0018). Paragraph 0057 of Forrest et al. teaches that the triplet exciton energy of the blocking material is preferably greater than that of the emissive molecule in the emissive layer (EML) or greater than that of any EML material, so as to allow for an energy barrier which prevents the leakage of triplet excitons from the emissive layer into adjacent transport layers. More specifically, paragraphs 0058-0060 of Forrest et al. further teach that the blocking material preferably has a triplet energy of at least 0.1 eV or greater than the triplet energies of the emission layer materials. The exemplified blocking layer is a mixture of Tris-PCz and CzSi in 1:1 or 1:3 ratios (paragraph 0081). Both Tris-PCz and CzSi are light-emitting compounds as evidenced by technical data sheets from Ossila. Specifically, Tris-PCz is taught as having a triplet energy level of 2.7 eV and a fluorescence emission maximum of 415 nm and CzSi is taught as having a triplet energy of 3.02 eV and a fluorescence emission maximum of 354 nm as evidenced by Ossila. As such, the blocking layer taught by Forrest et al. qualifies as an emission layer which does not comprise a dopant. The emission layer taught by Forrest et al. is exemplified to include a single host material (mCBP) and a phosphorescent iridium dopant [Ir(dmp)3] (paragraph 0081). The light-emitting devices taught by Forrest et al. are light-emitting devices (1) which comprise a first electrode (110), a second electrode (150) facing the first electrode, and an interlayer (130) comprising an emission layer, wherein the emission layer comprises a first emission layer and a second emission layer, the first emission layer comprises a first host (TH1) comprising a first-first host and a first-second host and does not comprise a dopant, and the second emission layer comprises a second host (TH2) which comprises a second-first host and a dopant where the first-first host and the first-second hosts are different from each other. Forrest et al. further teaches that the triplet energy level of TH1 is greater than the triplet energy of TH2.
The teachings of Forrest et al. differ from independent claim 1 in that the emission layer taught by Forrest et al. does not further comprise a second-second host. However, it would have been obvious to one having ordinary skill in the art to have employed mixed host systems given the teachings of Lee et al. Forrest et al. and Lee et al. are combinable as they are both from the same field of organic electroluminescent devices. Lee et al. teaches various mixed-host systems for OLEDs. Lee et al. includes many teachings which describe the benefits of employing a mixed-host system compared to a single-host system. Specifically, a single-host material must play the role of both hole-transporting host and electron-transporting host, whereas a mixed-host system allows for one host to serve as a hole-transporting host and the other host to serve as the electron-transporting host. As such, mixed hosts can inject holes and electrons from the charge transport layers to the emitting layer and have good hole and electron transport properties at the same time. This allows for good charge balancing of electrons and holes and also allows for fine tuning of the charge mobility by varying the amounts and types of each host material. Such flexibility cannot be achieved with single host systems. With this teaching and motivation to employ a mixed-host system, one having ordinary skill in the art would have found it obvious to prepare a light-emitting device which satisfies all of the device limitations of claim 1.
Claims 2-4: The devices which are rendered obvious by the teachings of Forrest et al. in view of Lee et al. satisfy Condition 1 of claim 2, Condition 1-1 of claim 4 and the interlayer limitations of claim 3, as described in claim 1 above.
Claim 5: Figure 4 of Forrest et al. depicts the relative thickness of each of the layers in the devices taught therein. The blocking layer shown in Figure 4 has a thickness of about 5 nm, or 50 Å, and the emission layer has a thickness of about 50 nm, or 500 Å which satisfies the criteria that the thickness of the first emission layer is smaller than the thickness of the second emission layer as recited in claim 5. Forrest et al. more generally teaches that the thickness of the mixed blocking layer is between 5-20 nm (paragraph 0080).
Claim 6: The thickness of the mixed blocking layer is taught by Forrest et al. to be between 5-20 nm (paragraph 0080) which falls within the about 50 Å to about 150 Å range for the first emission layer of claim 6. The thickness of the light-emitting layer (second emission layer) exemplified by Forrest et al. is taught to be 500 Å. While this value sits just above the upper limit of “about 450 Å”, one having ordinary skill in the art understands that the thickness of the emission layer is a result-effective variable. Adjustments to the layer thickness of an emission layer can be used to adjust the driving voltage of the device as thicker emission layers generally have higher driving voltages. For this reason, it would have been obvious for a person having ordinary skill in the art to have adjusted the thickness of the emission layer to include values within that required by claim 6.
Claims 7 and 8: While the exemplified device taught by Forrest et al. is a red phosphorescent emitter, Forrest et al. explicitly teaches that the wavelength of an organic emissive layer may be tuned with appropriated dopants (paragraph 0004). One having ordinary skill in the art understands that the preparation of other light-emitting devices which emit light in other parts of the visible spectrum, including blue, would have been obvious given this teaching. The motivation to prepare other emission colors is rooted in the desire to achieve any desired color output, including blue light, thereby satisfying claim 7. Blue light emission includes the about 400 nm to about 490 nm as recited in claim 8.
Claim 9: The devices taught by Forrest et al. have the blocking layer and the emission layer in direct contact with each other.
Claim 10: By virtue of the triplet energy in the mixed blocking layer of Forrest et al. being higher than the triplet energy of the emission layer of Forrest et al., any triplet excitons formed in the blocking layer would migrate to the emission layer, thereby satisfying claim 10.
Claim 11: For claim 11, Formula 1 is effectively so broad that it captures the materials employed in the mixed blocking layer of Forrest et al. as well as all of the different types of hole transport host materials and electron transport host materials taught by Lee et al.
Claims 15 and 17: The dopant employed by Forrest et al. is an iridium-containing phosphorescent dopant, thereby satisfying claims 15 and 17.
Claim 16: The dopant employed by Forrest et al. is Ir(III) bis(2-phenylquinolyl) acetylacetonate, which is a red emitter having the structure
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which satisfies Formulae 3 of claim 16 with L32 being acetylacetonate, which is an organic ligand, and L31 being a ligand which satisfies formula 3a of claim 16 with T31 equal to a single bond, CY32 equal to benzene, CY31 equal to quinoline, X33 and x34 equal to single bonds, b31 and b32 equal to zero, and M3 equal to iridium.
Claim 18: The devices taught by Forrest et al. are themselves an electronic apparatus which satisfies claim 18.
Claim 19 is rejected under 35 U.S.C. 103 as being unpatentable over Forrest et al. (US 2017/0104172) in view of Toguchi et al. (US 2003/0043571) as applied to claims 1 and 18.
Forrest et al. teaches a light-emitting device as described above. While Forrest et al. does not teach an electronic apparatus which is driven by a thin-film transistor as required by claim 19, the preparation of such a device would have been obvious to a person having ordinary skill in the art given the teachings of Toguchi et al. Forrest et al. and Toguchi et al. are combinable as they are both from the same field of organic electroluminescent devices. Toguchi et al. teaches a light-emitting display device which is comprised of a plurality of light-emitting pixels, a power supply to power said pixels, and thin-film transistors which are electrically coupled between the power supply and the organic electroluminescent device (Fig. 14 and claim 21 of Toguchi et al.). The thin-film transistor search to control the conduction between the common power supply and the organic electroluminescent device (paragraph 0027). The thin-film transistors are comprised of a source electrode and a drain electrode (paragraph 0115). The thin-film transistor is a critical part of the device architecture which allows for precise current control and active matrix addressing, which would improve the power efficiency in the light-emitting devices taught by Pavicic et al. The combination of Forrest et al. and Toguchi et al. involves the use of a known element to perform its known function in a known environment to achieve a predictable result. Further, in the field of OLEDs, connecting the source or drain of a driving transistor to a light-emitting load is the standard industry configuration for controlling brightness.
Claim 20 is rejected under 35 U.S.C. 103 as being unpatentable over Forrest et al. (US 2017/0104172) in view of Yamazaki et al. (US 2005/0073247) as applied to claims 1 and 18.
While Forrest et al. does not explicitly teach that the electronic apparatus taught therein further comprises one of the elements recited in claim 20, it is submitted that the inclusion of at least a color filter layer to the electronic apparatus taught by Forrest et al. would have been obvious to a person having ordinary skill in the art given the teachings of Yamazaki et al. Forrest et al. and Yamazaki et al. are combinable as they are both from the same field or organic electroluminescent devices. Yamazaki et al. teaches light-emitting devices which comprise a color filter. Yamazaki et al. teaches that it is often the case that the spectrum of light emitted from a light-emitting element has a broad emission peak which means that the color purity is inferior. Applying a color filter serves to improve the color purity and also the reliability as disclosed in paragraph 0017 of Yamazaki et al. For this reason, one having ordinary skill in the art would have been motivated to include a color filter to the electronic apparatus taught by Forrest et al., thereby satisfying claim 20.
Allowable Subject Matter
Claims 12-14 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 mixed blocking layer taught by Forrest et al. does not comprise an electron-transporting moiety. Claims 12 and 14 requires that at least one of the four host materials in the two emission layers of claim 1 comprises an electron transporting moiety. Claim 13 is allowable by virtue of its dependency on claim 12.
Relevant Art Cited
Additional prior art documents which are relevant to Applicants invention can be found on the attached PTO-892 form. A closely related prior art reference is Lee et al. (US 2019/0207118, cited on Applicants information disclosure statement, filed on 12/23/22). Lee et al. exemplifies light-emitting devices which satisfy all of the limitations of claim 1 with the notable exception that the triplet energy level of the first host (TH1) and the second host (TH2) is the same since the first and third hosts present in each of the two emission layers are identical and the second and fourth hosts present in each of the two emission layers are identical. While the teachings of Lee et al. do not necessarily require that the first and third and second and fourth materials are both identical, there is nothing taught or suggested by Lee et al. which would make it obvious to a person having ordinary skill in the art to employ different first and third hosts and/or different second and fourth hosts and to further change the hosts such that the first emission layer has a higher triplet energy level than the second emission layer.
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