DETAILED ACTION
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 .
Claim Status
Applicant amendments of claims 1, 3, 4, 12, and 17 dated 31 December 2025 are acknowledged. Claims 12-18 were previously withdrawn from consideration.
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.
Claims 1-11, and 19 are rejected under 35 U.S.C. 103 as being unpatentable over Park et al (US 20220208876 A1, hereinafter “Park”), in view of Mizuno (US 20140299854, hereinafter “Mizuno”), and further in view of Kawano et al (WO 20220003481 A1, hereinafter “Kawano”), and further in view of Liu et al (US 20180190940 A1, hereinafter “Liu”).
Regarding Claim 1 – Park discloses a light-emitting device comprising: a first electrode (anode 110 [0072]); a second electrode facing the first electrode (cathode 170 [0072]); and an interlayer between the first electrode and the second electrode (second stack S2 in [0072] considered to be an interlayer), wherein the interlayer comprises: a hole transport region including an electron blocking layer (layers 116 and 142 in [0068] and Fig. 8); a first emission layer between the electron blocking layer and the second electrode (251 in [0117] and Fig. 8); a second emission layer between the first emission layer and the second electrode (252 in [0117]); and an electron transport region between the second emission layer and the second electrode (117 and 118 in [0068] and Fig. 8), the electron transport region including a hole blocking layer (layer 117 in [0068] and Fig. 8).
Park fails to disclose a refractive index of the first emission layer is greater than a refractive index of the electron blocking layer, a refractive index of the second emission layer is equal to or greater than a refractive index of the hole blocking layer, and the refractive index of the electron blocking layer and the refractive index of the hole blocking layer measured at a wavelength of 450 nm are each independently about 1.77 or more and about 1.80 or less.
However, Mizuno discloses a refractive index of the first emission layer is greater than a refractive index of the electron blocking layer (Electron blocking layer part of hole transport layer, as in Mizuno [0042], hole transport layer is a low-refractive index layer as in Mizuno [0044], and low-refractive index layers have refractive index at least 0.1, preferably 0.2 or more, lower than the emission layer, Mizuno [0023]), and an example emission layer has a refractive index of 1.8-1.9 around 460 nm (Mizuno [0048]), which is similar or the same as the value expected at 450 nm (as shown in Mizuno Fig. 3). To achieve an electron blocking layer with refractive index of at least 0.1 lower than the emission layer requires an electron blocking layer with refractive index of at most 1.70-1.80, which overlaps the claimed range, can be achieved through routine optimization, and represents a prima facie case of obviousness (See MPEP 2144.05 (I and II)).
Park describes an organic light-emitting diode (OLED) with a layer stack including light emission, carrier transport, and blocking layers between two electrodes. Mizuno teaches a similar stack with the further advantage of achieving higher light extraction efficiency by setting the emission layer refractive index higher than that of the electron blocking layer (Mizuno [0080]). Therefore, it would have been obvious to one skilled in the art prior to the effective filing date of the instant application to combine the concepts from these two references to achieve the expected outcome of improved light extraction efficiency.
The combination of Park and Mizuno fails to disclose a refractive index of the second emission layer is equal to or greater than a refractive index of the hole blocking layer.
However, Kawano teaches a similar OLED comprising an anode electrode 101, a cathode electrode 102, and an EL layer 103 that includes a hole transport region 120 (comprising a hole injecting layer 111, a hole transport layer 112, and an electron blocking layer), a light-emitting layer 113, and an electron transport region 121 comprising an electron transport layer 114, and an electron injecting layer 115, and a hole blocking layer (Kawano [0041]-[0042] and annotated Fig. 1A), wherein a refractive index of the second emission layer is equal to or greater than a refractive index of the hole blocking layer (Second emission layer considered to be the emission layer 113 in Kawano [0043], and hole blocking layer is a low refractive index layer, as in Kawano [0045]).
Kawano presents an OLED with a low refractive index layer for the well-known advantage of improving light extraction efficiency (Kawano [0006]). Further, Kawano teaches selection and optimization of material layers to optimize light emission (For example, Kawano [0153]). Therefore, it would have been obvious to one skilled in the art prior to the effective filing date of the instant application to combine the teachings of Park and Mizuno with Kawano to enable the specified refractive index for the well-known advantage of improving light extraction efficiency.
The combination of Park, Mizuno, and Kawano fails to disclose the refractive index of the hole blocking layer measured at a wavelength of 450 nm is about 1.77 or more and about 1.80 or less.
However, Liu teaches a functional layer containing a hole blocking layer has a refractive index less than 1.8 in the wavelength range 400-700 nm, which includes 450 nm (Liu [0081-0082]). Therefore, the proposed refractive index range taught by Liu overlaps the claimed range, can be achieved through routine optimization, and represents a prima facie case of obviousness (See MPEP 2144.05 (I and II)).
Liu discloses a similar OLED layer stack to Park. Liu teaches making the refractive index within a functional layer between a light emitting layer and an electrode 1.8 or less to improve the light extraction efficiency of an organic light-emitting display device (Liu [0081]). Therefore, it would have been obvious to one of ordinary skill in the art prior to the effective filing date of the claimed invention to combine the teachings of Park and Liu to make the refractive index of a hole blocking layer 1.8 or less to improve the light extraction efficiency in an organic light-emitting display device.
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Regarding Claim 2 –Park modified by Mizuno, Kawano, and Liu discloses all the limitations of claim 1.
The combination of Park, Mizuno, Kawano, and Liu further discloses the electron blocking layer directly contacts the first emission layer (142 directly contacting 153 as in Park [0078] and 153 considered as 251 as in Park [0117] and annotated Fig. 8); the first emission layer directly contacts the second emission layer (251 and 252 as in Park [0117] and annotated Fig. 8); the second emission layer directly contacts the hole blocking layer (252 directly contacts 117 as in annotated Park Fig. 8 and 252 considered as 1200 in [0068]); or a combination thereof.
Regarding Claim 3 – Park modified by Mizuno, Kawano, and Liu discloses all the limitations of claim 1.
The combination of Park, Mizuno, Kawano, and Liu further discloses the refractive index of the first emission layer being greater than the refractive index of the electron blocking layer and the refractive index of the second emission layer being equal to or greater than the refractive index of the hole blocking layer reduces an amount of light generated from at least one of the first and second emission layers from being lost (interpreted as good light emitting efficiency, Kawano [0227]).
Each of these layers is presented as a low-refractive index layer by Kawano ([0043]) in a similar OLED to that of Park. Therefore, it would have been obvious to one skilled in the art prior to the effective filing date of the instant application to combine the teachings of Park and Kawano to set the blocking layer refractive index as described to achieve the well-known advantage of improved light extraction efficiency (Kawano [0006]).
Regarding Claim 4 – Park modified by Mizuno, Kawano, and Liu discloses all the limitations of claim 1.
The combination of Park, Mizuno, Kawano, and Liu further discloses the refractive index of the first emission layer and the refractive index of the second emission layer measured at a wavelength of approximately 450 nm are each independently in a range of about 1.85 to about 2.30 (In Kawano [0043], the refractive index of the emission layer is commonly 1.8-1.9, which overlaps the claimed range, creating a prima facie case of obviousness. See MPEP 2144.05(I)).
The emission layers in the claimed invention are sandwiched by transport regions containing blocking layers, similarly to the emission layer presented by Kawano ([0043]) in an analogous OLED. Kawano gives a typical emission layer refractive index of 1.8-1.9 (Kawano [0043]). Therefore, it would have been obvious to one skilled in the art prior to the effective filing date of the instant application that the emission layer would be in this range.
Regarding Claim 5 – Park modified by Mizuno, Kawano, and Liu discloses all the limitations of claim 1.
The combination of Park, Mizuno, Kawano, and Liu further discloses the refractive index of the first emission layer measured at a wavelength of approximately 450 nm is in a range of about 1.85 to about 2.30 (As shared by Kawano [0043], the refractive index of the emission layer is commonly 1.8-1.9, which is an overlapping range presenting a prima facie case of obviousness, as in MPEP 2144.05(I).
The emission layers in the claimed invention are sandwiched by transport regions containing blocking layers, similarly to the emission layer presented by Kawano ([0043]) in an analogous OLED. Kawano gives a typical emission layer refractive index of 1.8-1.9 (Kawano [0043]). Therefore, it would have been obvious to one skilled in the art prior to the effective filing date of the instant application that the emission layer would be in this range.
Regarding Claim 6 – Park modified by Mizuno, Kawano, and Liu discloses all the limitations of claim 1.
The combination of Park, Mizuno, Kawano, and Liu further discloses the refractive index of the second emission layer is equal to or greater than the refractive index of the first emission layer (The first emission layer is considered to be a “low refractive index layer” and the second emission layer considered to be the “emission layer” of Mizuno [0023]).
Mizuno teaches a similar OLED to Park with an emission layer sandwiched between hole and electron transport regions. Mizuno teaches placing a low-refractive index layer below (opposite the device emission direction) the top emission layer for the well-known advantage of improved light emission efficiency (Mizuno [0080]). Therefore, it would have been obvious to one skilled in the art prior to the effective filing date of the instant application to combine the concepts from these two references to achieve the expected outcome of improved light extraction efficiency.
Regarding Claim 7 – Park modified by Mizuno, Kawano, and Liu discloses all the limitations of claim 1.
The combination of Park, Mizuno, Kawano, and Liu further discloses the first emission layer and the second emission layer each independently emit blue light having a maximum emission wavelength in a range of about 450 nm to about 490 nm (The dopants in the first and second sub-layers, 251 and 252, have emission peaks in the 435-490 nm range as in Park [0151]).
Regarding Claim 8 – Park modified by Mizuno, Kawano, and Liu discloses all the limitations of claim 1.
The combination of Park, Mizuno, Kawano, and Liu further discloses the first emission layer comprises a first host and a first dopant, the second emission layer comprises a second host and a second dopant, and the first host and the second host are different from each other (251 has host h2 and 252 has host h3 as in Park [0117]).
Regarding Claim 9 – Park modified by Mizuno, Kawano, and Liu discloses all the limitations of claim 1.
The combination of Park, Mizuno, Kawano, and Liu further discloses the electron blocking layer comprises an arylamine-containing compound (electron blocking layer comprised in hole transport region of Kawano [0045]).
Kawano provides a similar OLED layer stack to Park, including an electron blocking layer. While Park is silent regarding electron blocking layer constituents, Kawano provides arylamine-containing compounds as options to provide hole transport properties (Kawano [0060]). Therefore, it would have been obvious to one skilled in the art prior to the effective filing date of the instant application and consider using an arylamine-containing compound in the electron blocking layer to gain the advantage of hole transport properties.
Regarding Claim 10 – Park modified by Mizuno, Kawano, and Liu discloses all the limitations of claim 1.
The combination of Park, Mizuno, Kawano, and Liu further discloses the first emission layer comprises a first host and a first dopant, and the second emission layer comprises a second host and a second dopant (251 has host “h2” and dopant “fd2”, 252 has host “h3” and dopant “nfd” as in Park [0117]).
The combination of Park, Mizuno, Kawano, and Liu further teaches both pyrene and anthracene as candidates for emission layers (Kawano [0129] and [0150]). Therefore, the first host can comprise a pyrene-containing compound, and the second host can comprise an anthracene-containing compound, or a combination thereof.
Kawano provides a similar OLED layer stack to Park. While Park is silent regarding emission layer chemical constituents, Kawano provides pyrene and anthracene compounds as options to result in good luminous efficiency and durability (Kawano [0149]-[0150]). Therefore, it would obvious to one skilled in the art prior to the effective filing date of the instant application to combine Park and Kawano to gain the advantage of good luminous efficiency and durability.
Regarding Claim 11 – Park modified by Mizuno, Kawano, and Liu discloses all the limitations of claim 1.
The combination of Park, Mizuno, Kawano, and Liu further discloses the hole blocking layer comprises a triazine-containing compound (hole blocking layer comprised in electron transport region of Kawano [0078]-[0083]).
Kawano provides a similar OLED layer stack to Park, including a hole blocking layer. While Park is silent regarding electron blocking layer constituents, Kawano provides triazine-containing compounds as options to provide electron transport properties (Kawano [0145]). Therefore, it would have been obvious to one skilled in the art prior to the effective filing date of the instant application and consider using an arylamine-containing compound in the electron blocking layer to gain the advantage of hole transport properties.
Regarding Claim 19 – Park modified by Mizuno, Kawano, and Liu discloses all the limitations of claim 1.
The combination of Park, Mizuno, Kawano, and Liu further discloses an electronic apparatus comprising the light-emitting device of claim 1 (Park [0121]-[0135] and Fig. 10).
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Claim 20 is rejected under 35 U.S.C. 103 as being unpatentable over Park et al (US 20220208876 A1, hereinafter “Park”), in view of Mizuno (US 20140299854, hereinafter “Mizuno”), and further in view of Kawano et al (WO 20220003481 A1, hereinafter “Kawano”), and further in view of Mitsumori et al (US 20170338436 A1, hereinafter “Mitsumori”).
Regarding Claim 20 – Park modified by Mizuno, Kawano, and Liu discloses all the limitations of claim 1.
The combination of Park, Mizuno, Kawano, and Liu to disclose an electronic apparatus comprising: the light-emitting device of claim 1 disposed on a substrate; and a color conversion layer located on at least one direction in which light emitted from the light-emitting device travels, wherein the color conversion layer comprises quantum dots.
However, Mitsumori discloses an electronic apparatus comprising: the light-emitting device of claim 1 disposed on a substrate (200 in Mitsumori annotated Fig. 7A and Mitsumori [0395]); and a color conversion layer located on at least one direction in which light emitted from the light-emitting device travels, wherein the color conversion layer comprises quantum dots (Optical elements 224R, 224G, and 224B are quantum-dot containing color conversion layers for light emitting opposite the substrate as shown in Mitsumori Fig. 7A and described in Mitsumori [0400]).
Park and Mitsumori both relate to the construction of OLEDs and apparatus using OLEDs. Mitsumori adds optical elements that can be used as color conversion layers using quantum dots to gain the benefit of increased color reproducibility (Mitsumori [0400]). Thus, it would have been obvious to one skilled in the art prior to the effective filing date of the instant application to combine the teachings of Park and Mitsumori using quantum dot containing conversion layers on the light emitting side of an OLED to obtain the expected outcome of color reproducibility.
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Response to Arguments
Applicant's arguments filed 31 December 2025 have been fully considered but they are not persuasive.
Argument – The applicant presents the argument that “...none of the references teaches or remotely suggests a refractive index of an electron blocking layer and a refractive index of a hole blocking layer measured at a wavelength of 450 nm are each independently about 1.77 or more and about 1.80 or less.”
Regarding Applicant’s Argument – The examiner respectfully submits that the combination of Park, Mizuno, Kawano, and Liu discloses:
- a refractive index of the first emission layer is greater than a refractive index of the electron blocking layer (Electron blocking layer part of hole transport layer, as in Mizuno [0042], hole transport layer is a low-refractive index layer as in Mizuno [0044], and low-refractive index layers have refractive index at least 0.1, preferably 0.2 or more, lower than the emission layer, Mizuno [0023]), and an example emission layer has a refractive index of 1.8-1.9 around 460 nm (Mizuno [0048]), which is similar or the same as the value expected at 450 nm (as shown in Mizuno Fig. 3). To achieve an electron blocking layer with refractive index of at least 0.1 lower than the emission layer requires an electron blocking layer with refractive index of at most 1.70-1.80, which overlaps the claimed range, can be achieved through routine optimization, and represents a prima facie case of obviousness (See MPEP 2144.05 (I and II)).
- a functional layer containing a hole blocking layer has a refractive index less than 1.8 in the wavelength range 400-700 nm, which includes 450 nm (Liu [0081-0082]). Therefore, the proposed refractive index range taught by Liu overlaps the claimed range, can be achieved through routine optimization, and represents a prima facie case of obviousness (See MPEP 2144.05 (I and II)).
Conclusion
Any inquiry concerning this communication or earlier communications from the examiner should be directed to JASON MCDONALD whose telephone number is (571) 272-5944. The examiner can normally be reached M-F 7:30a-5p Eastern, alternating Fridays out of office.
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/JASON MCDONALD/Examiner, Art Unit 2898 /JULIO J MALDONADO/Supervisory Patent Examiner, Art Unit 2898