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.
Claims 1-6, 9-12 and 14-20 are rejected under 35 U.S.C. 103 as being unpatentable over US 2020/0203652 A1 to Duan et al. in view of Zhang et al. Nat. Commun. 5:5008 doi: 10.1038/ncomms6008 (2014).
Regarding claim 1, Duan et al. discloses an OLED having the general configuration of anode/HTL/EML/ETL/cathode wherein the EML comprises a wide-bandgap host material (20-98.9%), a TADF sensitizer (1-60%) and a resonant TADF (rTADF) dopant (0.1-20%). The design is to dilute the excitons so as to minimize triplet-triplet annihilation (TTA) and exciton-polaron annihilation (TPA) (pp. 2-3). Also disclosed is a display device comprising the OLED (claim 20). Duan et al. fails to teach an EML made of a plurality of layers wherein the concentration of the rTADF dopant is increasing from one electrode to the other. On the other hand, Zhang et al. discloses a method of diluting the triplet excitons in the EML of an OLED so as to avoid TTA and TPA, wherein the method comprises broadening the thickness of the EML and decreasing the concentration of the dopant from the anode side to the cathode side, e.g., linearly from 18 vol% to 8 vol% (p. 2). The method increases the lifetime of the device up to tenfold (p. 5). Therefore, it would have been obvious to a person of ordinary skill in the art at the time the instant invention was filed to modify the device disclosed by Duan et al. by giving a gradient to the concentration of the rTADF dopant across the thickness of the EML, with the highest concentration on the anode side, so as to improve the performance and lifetime of the device. Note that the resulting device is equivalent to one comprising N emitting layers stacked together where the concentration of the dopant/emitter is linearly decreasing from the anode side to the cathode side. Claim 1 is therefore unpatentable for being obvious. See MPEP § 2143(I)(C). So are claims 2-5, 11-12, 14-15 and 17-20. The features of claims 6 and 9-10 can be found in the examples and on pages 4+. The features of claim 16 are suggested by Zhang et al. (Device D3 on page 2).
Allowable Subject Matter
Claims 7-8 and 13 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 following is a statement of reasons for the indication of allowable subject matter: Duan et al., which represents the closest prior art of record, fails to suggest the organoboron dopant of claim 7 or the host material of claim 13 and there is not an obvious reason for a POSITA to modify the prior art device to arrive at the device of claim 7 or claim 13.
Contact Information
Any inquiry concerning this communication or earlier communications from the examiner should be directed to VU ANH NGUYEN whose telephone number is (571)270-5454. The examiner can normally be reached M-F 8:00 AM-5:00 PM.
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, ROBERT JONES can be reached at (571) 270-7733.
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.
/VU A NGUYEN/Primary Examiner, Art Unit 1762
Prosecution Insights