Patent ID: 8569750

Claim:
An organic electroluminescence element comprising: an organic light emission layer which comprises a light emission layer including a luminescent material, said organic light emission layer being provided with a first surface and a second surface which is opposite of said first surface, a light reflective electrode being disposed on said first surface, a light transmissive electrode being disposed on the second surface, a light scattering layer being disposed on the light transmissive electrode, a light transmissive substrate being disposed on said light scattering layer, a light reflective electrode being spaced from a luminous point of said light emission layer by a distance d, wherein the distance “d” is defined by following formula, nd = a × λ 4 ⁢ { 2 ⁢ m + ϕ π } ( 1 ) wherein ϕ = tan - 1 ⁢ { 2 ⁢ ( n 1 ⁢ k 2 - n 2 ⁢ k 1 ) n 1 2 - n 2 2 + k 1 2 - k 2 2 } wherein λ is defined by a wavelength of a predetermined light which is emitted from the light emission layer, n is a refractive index of a layer which is located between the luminous point and the light reflective electrode at the light having the wavelength λ, n 1 is a refractive index of a layer which is located between the luminous point of the light emission layer and the light reflective electrode and which is in contact with the light reflective electrode, at the light having the wavelength λ, k 1 is an extinction coefficient of the layer which is located between the luminous point of the light emission layer and the light reflective electrode and which is in contact with the light reflective electrode, at the light having the wavelength λ, n 2 is a refractive index of the light reflective electrode at the wavelength λ of the light, k 2 is an extinction coefficient of the light reflective electrode at the light having the wavelength λ, wherein m is equal to 0 or 1, when m is equal to 0, “a” satisfies a following formula −1.17 ×n org /n EML +1.94 ≦a≦− 0.16 ×n org /n EML +2.33 wherein when m is equal to 1, “a” satisfies a following formula 0.28 ×n org /n EML +0.75 ≦a≦ 2.85 ×n org /n EML −1.23 wherein n org is a refractive index of a layer which is in contact with the light emission layer and which is located on a same side of the light emission layer as the light reflective electrode at the light having the wavelength λ, n EML is a refractive index of the light emission layer at the light having the wavelength λ.