Patent ID: 7508127

Claim:
A multicolor light-emitting device comprising at least a first and a second organic electroluminescence devices provided on a substrate, the first and the second organic electroluminescence devices emitting lights of different colors, and each of the organic electroluminescence devices having at least; a first electrode arranged on a side of reflecting light; a second electrode, opposed to the first electrode, arranged on a side of light extracted; and an electroluminescence layer comprising an organic compound layer arranged between the first electrode and the second electrode, the first electrode being provided closer to the substrate than the second electrode; wherein a light-emitting region of the first organic electroluminescence device is located on the first electrode side of the electroluminescence layer of the first organic electroluminescence device, wherein a light-emitting region of the second organic electroluminescence device is located on the second electrode side of the electroluminescence layer of the second organic electroluminescence device, wherein the electroluminescence layer of the first organic electroluminescence device is a layer having a carrier transporting property in which electrons are more readily transported compared to holes, and the electroluminescence layer of the second organic electroluminescence device is a layer having a carrier transporting property in which holes are more readily transported compared to electrons, wherein each of the first and the second organic electroluminescence devices has a first layer between the electroluminescence layer and the first electrode, and has a second layer between the electroluminescence layer and the second electrode, wherein a thickness (da 1 ) of the first layer of the first organic electroluminescence device satisfies the following equation: n ⁢ ⁢ 1 ⁢ ⁢ da ⁢ ⁢ 1 = λ ⁢ ⁢ a 4 ⁢ ( 1 + 2 ⁢ ⁢ i ) wherein i denotes zero or a positive integer, n 1 denotes a refractive index of a first charge-transporting layer, and λa denotes a peak emission wavelength of one organic electroluminescence device; and a thickness (db 1 ) of the first layer and a thickness (db 3 ) of the electroluminescence layer of the second organic electroluminescence device satisfy the following equation: nb ⁢ ⁢ 1 ⁢ ⁢ db ⁢ ⁢ 1 + nb ⁢ ⁢ 3 ⁢ db ⁢ ⁢ 3 = λ ⁢ ⁢ b 4 ⁢ ( 1 + 2 ⁢ ⁢ i ) and wherein i denotes zero or a positive integer, nb 1 denotes the n 1 , db 1 =da 1 , nb 3 denotes a refractive index of the electroluminescence layer of the one organic electroluminescence device, and λb denotes a peak emission wavelength of one organic electroluminescence device.