Light-emitting element
View Patent ↗The light-emitting element emits light itself. The element includes a light-emitting portion having a higher refractive index than a refractive index of air and a diffraction grating structure provided to a light-emitting side surface of the light-emitting portion. The function that a minimum light-emission value is equal to or less than 50% of a maximum light-emission value when white light is emitted from the light-emitting portion is realized. The function is obtained by further including a color-separation filter provided between the light-emitting portion and the light-emitting side surface and making a minimum value of a spectral product obtained from a light-emission waveform of the white light emitted from the light-emitting portion and a spectral transmittance of said color-separation filter equal to or less than 50% of a maximum value thereof, or by adjusting a light-emission ratio of the light-emitting materials for said at least two primary colors among the light-emitting materials for the three primary colors.
1. A light-emitting element which emits light using organic electroluminescence, comprising:
a light-emitting portion having a higher refractive index than a refractive index of air, comprising:
a transparent substrate,
a transparent electrode formed on one side of said substrate,
an organic compound layer formed on said transparent electrode, said organic compound layer including a light-emitting layer, and
a rear electrode formed on said organic compound layer;
a color-separation filter formed on the other side of said substrate,
a diffraction grating structure formed on said color-separation filter, having a pitch of a fine convex-concave structure being in a range from 1 μm to 4 μm, and a depth of the fine convex-concave structure being in a range from 0.4 μm to 4 μm,
wherein said color separation filter is selected so that, when white light is emitted from said light-emitting portion, a minimum value of a spectral product obtained from a light-emission waveform of the white light and a spectral transmittance of said color-separation filter is equal to or less than 50% of a maximum value thereof.
2. A light-emitting element which emits light using organic electroluminescence, comprising:
a light-emitting portion having a higher refractive index than a refractive index of air, comprising:
a transparent substrate,
a transparent electrode formed on one side of said substrate,
an organic compound layer formed on said transparent electrode, said organic compound layer including a light-emitting layer, and
a rear electrode formed on said organic compound layer;
a color-separation filter formed on the other side of said substrate,
a diffraction grating structure formed on said color-separation filter, having a pitch of a fine convex-concave structure being in a range from 1 μm to 4 μm, and a depth of the fine convex-concave structure being in a range from 0.4 μm to 4 μm,
wherein said light-emitting portion emits white light, and
wherein a minimum value of a spectral product obtained from a light-emission waveform of the white light and a spectral transmittance of said color-separation filter is equal to or less than 50% of a maximum value thereof.
3. A light-emitting element which emits light using organic electroluminescence, comprising:
a light-emitting portion having a higher refractive index than a refractive index of air, comprising:
a transparent substrate,
a transparent electrode formed on one side of said substrate,
an organic compound layer formed on said transparent electrode, said organic compound layer including a light-emitting layer, and
a rear electrode formed on said organic compound layer;
a diffraction grating structure formed on the other side of said substrate, said diffraction grating structure having a pitch of a fine convex-concave structure being in a range from 1 μm to 4 μm, and a depth of the fine convex-concave structure being in a range from 0.4 μm to 4 μm,
wherein said light-emitting layer includes light-emitting materials for at least two primary colors emitting white light among light-emitting materials for three primary colors, and
wherein a light-emission ratio of the light emitting materials for said at least two primary colors among the light-emitting materials for the three primary colors is adjusted to make a minimum light-emission value equal to or less than 50% of a maximum light-emission value when white light is emitted from said light-emitting portion.
4. A light-emitting element which emits light using organic electroluminescence, comprising:
a light-emitting portion having a higher refractive index than a refractive index of air, comprising:
a transparent substrate,
a transparent electrode formed on one side of said substrate,
an organic compound layer formed on said transparent electrode, said organic compound layer including a light-emitting layer, and
a rear electrode formed on said organic compound layer;
a diffraction grating structure formed on the other side of said substrate, said diffraction grating structure having a pitch of a fine convex-concave structure being in a range of 1 μm to 4 μm, and a depth of the fine convex-concave structure being in a range from 0.4 μm to 4 μm,
wherein said light-emitting layer includes light-emitting materials for at least two primary colors among light-emitting materials for three primary colors,
wherein said light-emitting portion emits white light, and
wherein a minimum light-emission value is equal to or less than 50% of a maximum light-emission value.