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 § 102
The following is a quotation of the appropriate paragraphs of 35 U.S.C. 102 that form the basis for the rejections under this section made in this Office action:
A person shall be entitled to a patent unless –
(a)(1) the claimed invention was patented, described in a printed publication, or in public use, on sale or otherwise available to the public before the effective filing date of the claimed invention.
Claims 1, 3-7, 12, 13, 16, and 18 are rejected under 35 U.S.C. 102(a)(1) as being anticipated by Lee et al. (Small 2019, 15, 1905162).
Claim 1: Lee et al. teaches inverted quantum dot based light-emitting diodes. Figure 1 shows that structure of the light-emitting diodes. The device in Figure 1 comprises a reflective, thick Ag cathode, zinc oxide nanoparticles as an electron injection/electron transport layer, a layer of PFN, which is a polymeric interlayer which functions as an electron transport layer, an emission layer comprising InP quantum dots, an hole transport layer (TCTA), a hole injection layer (MoOx), and a transparent anode. Figure 2(a) shows that the cathode is reflective and the anode is transparent. The device taught by Lee et al. therefore anticipates all of the device limitations of claim 1.
Claim 3: The cathode in the device taught by Lee et al. is a silver cathode, which anticipates claim 3.
Claim 4: The device taught by Lee et al. includes a hole transport region comprising a hole transport layer and a hole injection layer, thereby anticipating claim 4.
Claims 5-7: In the device taught by Lee et al. shows that the ZnO and PFN are in direct contact with each other, ZnO is in direct contact with the cathode, and PFN is in direct contact with the emission layer, thereby anticipating claims 5-7.
Claim 12: As shown in Figure 1(c) of Lee et al., the thickness of the ZnO electron transport layer is thicker than the PFN electron transport layer, thereby anticipating claim 12.
Claim 13: Figure 1(b) of Lee et al. shows that the thickness of the ZnO nanoparticle layer is greater than 20 nm (200 Å) but less than 400 nm (4,000 Å), thereby anticipating claim 13.
Claim 16: The emission layer in the device taught by Lee et al. comprises a quantum dot, thereby anticipating claim 16.
Claim 18: The device taught by Lee et al. is in itself an electronic apparatus comprising a light-emitting device which anticipates claim 1, thereby anticipating claim 18.
Claim 20 is rejected under 35 U.S.C. 102(a)(1) as being anticipated by Kim et al. (US 2020/0139737).
Kim et al. teaches a method for manufacturing a light-emitting device wherein a light-emitting display device is prepared where a hole injection layer, a hole transport layer, an organic emission layer, an electron transport layer, an electron injection layer are formed by an inkjet printing method (paragraph 0113). Fig. 9 shows the electron transport layer as 617 and the electron injection layer as 619. However, the electron injection layer is also inherently an electron transport layer. For this reason, Kim et al. anticipates a method wherein a first and second electron transport layer are formed via an ink-jetting process.
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 1-5, 7-9, and 12-19 are rejected under 35 U.S.C. 103 as being unpatentable over Lee et al. (US 2019/0131557, cited on Applicants information disclosure statement, filed on 8/29/23).
Claim 1: Lee et al. teaches light-emitting diodes and light-emitting devices comprising the same. Included in the device embodiments of Lee et al. are inverted LEDs which have the device architecture shown in Fig. 4. As seen in Fig.4 the device architecture consists of a first electrode, which for an inverted LED serves as a cathode, an charge transport region (240) comprising injection layer (242), an electron transport region (244) which consists of an inorganic electron transport layer (244b), an organic electron transport layer (244a), an emission layer (250), a hole transport region (260) comprising a hole transport layer (264) and a hole injection layer (262) and a second electrode (220) which serves as an anode. In paragraph 0098 of Lee et al. the first electrode 210 is a cathode such as an electron injection electrode. Lee et al. teaches that the first electrode 210 may be made of a doped or undoped metal oxide including ITO, IZO, SnO2, and ZnO, or may be made of a material including silver. The electron transport layer (244b) is taught by Lee et al. as being made of an inorganic material having a very deep valence band energy level with all specifically taught materials being inorganic oxides including, ZnMgO, TiO2, and SnO2 (paragraph 0104). The electron transport layer (244a) is taught by Lee et al. as being made of an organic material (paragraph 0103).
While Lee et al. does not explicitly teach that the first electrode/cathode is a reflective electrode, Lee et al. explicitly teaches that when the light-emitting display devices taught therein is a top-emission type, a reflective electrode may be further formed on a lower portion of the first electrode (paragraphs 0130-0131). In such embodiments, the electrode which is selected as the bottom cathode, which is a material selected from those materials taught in paragraph 0130 would additionally have a reflective portion as taught in paragraph 0131. One having ordinary skill in the art would have therefore found it prima facie obvious to have employed a reflective electrode to serve as the cathode given that such an embodiment is explicitly taught. Further, one would have been additionally motivated to prepare a top-emitting LED since light emitted from the top of the device does not have any obstruction compared to a bottom-emission type, where light emitted would have to travel through several layers before being “released” from the device. Given the teachings of Lee et al. the preparation of a light-emitting device comprising a first electrode which is a reflective cathode, a second electrode which is an anode, an interlayer between the first and second electrodes which is an emission layer, an electron transport layer between the first electrode and the emission layer wherein the electron transport layer is comprised of a first electron transport layer comprising an inorganic oxide and a second electron transport layer comprising an organic material would have been prima facie obvious to a person having ordinary skill in the art for the reasons described above.
Claims 2 and 3: As taught by Lee et al. in paragraph 0098, the first electrode may be a doped or undoped metal oxide including those recited in claim 2 or may be made of a material which comprise silver. The selection of any one of the materials to serve as the bottom electrode (cathode) is prima facie obvious to a person having ordinary skill in the art, thereby satisfying claims 2 and 3.
Claim 4: As shown in Fig. 4 of Lee et al., the inverted LEDs further comprise a hole transport region comprising a hole transport layer and a hole injection layer, thereby satisfying claim 4.
Claims 5 and 7: As shown in Fig. 4 of Lee et al. the first electron transport layer is in direct contact with the second electron transport layer and the second electron transport layer is in direct contact with the emission layer, thereby satisfying claims 5 and 7.
Claims 8 and 9: The metal oxides which are taught to be suitable to serve as the inorganic electron transport layer include, inter alia, ZnMgO, TiO2, and SnO2. The selection of any one of the explicitly taught inorganic oxides, including those recited above, is prima facie obvious to one having ordinary skill in the art, thereby satisfying claims 8 and 9.
Claim 12: Lee et al. teaches that the preferable thickness of the electron transport layer 244 which includes the first inorganic electron transport layer and the second organic electron transport layer is about 10 nm to about 100 nm, or about 100 Å to about 1000 Å. The working examples teach that the first and second electron transport layers have the same thickness 20 nm. However, Lee et al. is not limited to the working example thickness. A person having ordinary skill in the art seeking to achieve a total thickness of, for example 60 nm, would naturally consider any combination of thicknesses for the individual layers, for example 40 nm for the first electron transport layer and 20 nm for he second electron transport layer. Since the claim does not specify a critical ratio, any configuration where T1 + T2 is between 10 nm and 100 nm and where T1 is greater than T2 falls within the teachings of Lee et al. The thickness of each individual electron transport layer is a result-effective variable. In OLEDs, layer thickness is adjusted, for example, to turn the electron flow to match the hole injection or to adjust the distance between the emissive layer and the reflective electrode to maximize light outcoupling. It would have therefore been obvious to one of ordinary skill in the art to arrive at the limitations of claim 12 through routine experimentation. Since Lee et al. teaches a range for the total thickness, optimizing the individual contribution of the first layer versus the second layer to improve device efficiency or color purity is a matter of design choice and engineering optimization.
Claims 13 and 14: Lee et al. teaches that the preferable thickness of the electron transport layer 244 which includes the first inorganic electron transport layer and the second organic electron transport layer is about 10 nm to about 100 nm, or about 100 Å to about 1000 Å. Given this teaching, each of the first and second electron transport layers must have a thickness within the above range. For example, if the total thickness of the electron transport layer 244 is 80 nm, each of the first and second electron transport layers must individually have a thickness of less than 80 nm, but greater than 0 nm. Additionally, the working examples of Lee et al. teaches a thickness of the first electron transport layer of 20 nm (200 Å) and a thickness of the second electron transport layer of 20 nm (paragraph 0146). While this working example is not an inverted LED embodiment, one having ordinary skill in the art would have found it obvious to employ the same film thicknesses in an inverted LED embodiment, or at the very least, have found it obvious to have employed film thicknesses of the first and second electron transport layers of 20 nm as an obvious starting point. As such, the limitations of claims 13 and 14 are obvious given the overall teachings of Lee et al.
Claim 15: Example 1 of Lee et al. is drawn to an embodiment where all of the layers of the LED are deposited via a spin-coating process (paragraph 0146). Given this teaching, it would have been obvious to one having ordinary skill in the art to have employed a spin-coating process to deposit each of the layers present in the device architecture shown in Fig. 4. While spin-coating is not technically an inkjet process, both spin-coating and ink-jetting are solution deposition processes and claim 15 is written using product-by-process claim language. For product-by-process claims, patentability is based on the product itself, and not on the means of its production. It would be not be expected that a spin coating method and an ink-jetting method would materially affect the light-emitting device as claimed. Additionally, Lee et al. explicitly teaches that the electron injection and electron transport layers may be formed using a solution process which includes inkjet printing (paragraph 0086). One having ordinary skill in the art would have therefore considered the use of inkjet printing as a means to deposit the electron transporting materials taught by Lee et al.
Claim 16: The emission layer in the devices taught by Lee et al. may be comprised of quantum dots, thereby satisfying claim 16 (paragraphs 0106-0108).
Claim 17: Lee et al. teaches that the LED may emit white light (paragraph 0052). It is understood that in such embodiments, a plurality of red, green, and blue pixels are present as taught in paragraphs 0040 and 0052. Preparing such a pixel display would require that each of the red, green, and blue pixels have a device architecture as shown in Fig. 2 or Fig. 4. That is to say, each of the red, green, and blue subpixels would each be comprised of a first and second electron transport layer as shown in the figures. Additionally, the thickness of each of the first and second electron transport layers for each of the subpixels must either be identical to each other or different from each other, thereby satisfying claim 17.
Claims 18 and 19: Fig. 6 of Lee et al. represents an electronic apparatus comprising a light-emitting device, and a thin-film transistor (Tr) which is electrically connected to the either the source or drain electrode as shown in Fig 6 and described in paragraph 013). Lee et al. further explicitly teaches that the LED shown in Fig. 6 may have an inverted structure (paragraph 0138). Therefore, Lee et al. teaches an electronic apparatus as shown in Fig. 6 which is an inverted LED satisfying the limitations of claims 18 and 19.
Claims 20, 21, and 24 are rejected under 35 U.S.C. 103 as being unpatentable over Lee et al. (US 2019/0131557), further in view of Utsumi et al. (WO 2020/121398). The rejection of claim 1 to Lee et al. above is wholly incorporated into the rejection of claim 20. Copies of the original and a machine translation of Utsumi et al. are included with this Office action.
Claim 20: Lee et al. teaches inverted light-emitting diodes which are described in claim 1 above. Lee et al. teaches the devices taught therein may be prepared where an inkjet printing method is employed, which includes depositing the first and second electron transport layers via an inkjet printing method (paragraph 0086). Given this teaching, one having ordinary skill in the art would have found it prima facie obvious to have employed an inkjet printing method to deposit the first and second electron transport layer as Lee et al. explicitly teaches that such a method may be employed.
Additionally, one having ordinary skill in the art would have been motivated to employ an inkjet printing method to deposit the LED device layers as taught by Lee et al. given the teachings of Utsumi et al. Lee et al. and Utsumi et al. are combinable as they are both from the same field of quantum dot light-emitting diodes. Utsumi et al. teaches quantum dot display devices and further teaches that the electron transport layer is formed via an inkjet method (claim 9 of Utsumi et al.). Utsumi et al. further teaches that by using an inkjet method it is possible to coat a narrower range with higher accuracy that spin coating which results in an electron transport layer having high quality with respect to film thickness (page 10 of the machine translation). For this reason it would have been obvious to have employed an inkjet method in preparing the quantum dot light-emitting diodes as taught by Lee et al. As described in claim 1 above, Lee et al. teaches metal oxide electron transport layers which include materials which satisfy claim 21. Additionally, the device architecture taught by Lee et al. is an inverted quantum dot light-emitting device. As described in claim 1, Lee et al. teaches that the bottom cathode may be reflective. The reasons for including a reflective cathode is therefore obvious to a person having ordinary skill in the art given the teachings of Lee et al. for the reasons described in claim 1 above.
Claims 20 and 21 are rejected under 35 U.S.C. 103 as being unpatentable over Liu et al. (CN-106356469) in view of Park et al. (Phys. Status Solidi RRL 2020, 14, 1900737) as secondary reference. Copies of the original of Liu et al. and a machine translation are included with this Office action.
Claim 20: Park et al. teaches a method for preparing quantum dot light-emitting diodes wherein each layer of said light-emitting diodes are deposited using an inkjet printing method. The exemplified device comprises an ITO cathode, a layer of ZnO which serves as an electron injection/electron transport layer, a quantum dot emission layer, an hole transport layer, a hole injection layer, and an anode. While Park et al. does not explicitly teach inkjet printing a second electron transport layer, the inclusion of such a layer would have been obvious to one having ordinary skill in the art given the teachings of Park et al. Liu et al. and Park et al. are combinable as they are both from the same field of inverted quantum dot light-emitting diodes. Park et al. teaches a second electron transport layer, which is TBPi. Park et al. teaches that employing TBPi acts as void filler and charge balancer. Specifically, TBPi fills the pinholes and cracks present in the ZnO nanoparticle layer (which is the same nanoparticle layer taught by Park et al., abstract). Park et al. teaches a solution deposition method for TBPi. However, given the teachings of Liu et al., it would have been obvious to have deposited TBPi via an inkjet printing method as Liu et al. teaches such methods for the deposition of all of the layers in the light-emitting devices. A person having ordinary skill in the art would have expected TBPi to be well-suited to being employed in an inkjet printing method as TBPi is readily soluble in organic solvents.
Claim 21: While Liu et al. exemplifies ZnO as an electron transport layer material, Liu et al. is not limited to ZnO. Specifically, Liu et al. teaches that oxides comprising titanium, zinc, aluminum and tin may be employed (page 3 of the machine translation). As such, the employment of any one of these oxide in lieu of ZnO in the working example is prima facie obvious to a person having ordinary skill in the art.
Allowable Subject Matter
Claims 10, 11, 22, and 23 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. Each of claims 10 and 22 require that the first electron transport layer comprises a phosphine oxide compound and claims 11 and 23 are drawn to specific phosphine oxide compounds. The prior art references above do not teach or fairly suggest employing such compounds in the devices taught therein. A closely related prior art teaching for claims 10, 11, 22, and 23 is Wang (US 2022/0140240). Wang teaches an inkjet printing method for preparing organic light-emitting devices. The teachings of Wang include employing a phosphine oxide compound which is the same as compound 101 of claims 11 and 23 as an electron transport material, and wherein said material is deposited using an inkjet printing method (paragraphs 0014 and 0046-0051). However, Wang explicitly teaches and exemplifies that the electron injection layer is deposited using a vacuum evaporation method. Moreover, the materials taught by Wang to serve as the electron injection layer are exclusive from inorganic oxide compounds as claimed.
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