ELECTROLUMINESCENT DEVICE HAVING IMPROVED LIGHT OUTPUT
First Claim
1. An electroluminescent (EL) device, comprising:
- a substrate;
a light-emitting area formed over the substrate and comprising first and second electrodes and one or more EL unit(s) comprising at least one light-emitting layer formed between the electrodes, wherein at least one electrode comprises a transparent electrode;
a cover located over the light-emitting area; and
a light-scattering layer located between the substrate and cover, comprising transparent, light-scattering particles, wherein the ratio of the volume of light-scattering particles to the volume of the light-scattering layer is greater than 0.55 over a majority of the light-emitting area, wherein either the substrate or cover is transparent and transmits light emitted from the EL unit(s).
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Accused Products
Abstract
An electroluminescent (EL) device that includes a light-emitting area formed over a substrate. First and second electrodes and one or more EL unit(s) are included along with at least one light-emitting layer formed between the electrodes, wherein at least one electrode is transparent. A cover is located over the light-emitting area, and a light-scattering layer is located between the substrate and cover. The light-scattering layer includes transparent, light-scattering particles, wherein the ratio of the volume of light-scattering particles to the volume of the light-scattering layer is greater than 0.55 over a majority of the light-emitting area, wherein either the substrate or cover is transparent and transmits light emitted from the EL unit(s).
66 Citations
20 Claims
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1. An electroluminescent (EL) device, comprising:
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a substrate; a light-emitting area formed over the substrate and comprising first and second electrodes and one or more EL unit(s) comprising at least one light-emitting layer formed between the electrodes, wherein at least one electrode comprises a transparent electrode; a cover located over the light-emitting area; and a light-scattering layer located between the substrate and cover, comprising transparent, light-scattering particles, wherein the ratio of the volume of light-scattering particles to the volume of the light-scattering layer is greater than 0.55 over a majority of the light-emitting area, wherein either the substrate or cover is transparent and transmits light emitted from the EL unit(s). - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16)
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17. A method of forming an electroluminescent (EL) device comprising the steps of:
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a) providing an LED with a light-emitting area comprising a first electrode and a second transparent electrode and one or more EL unit(s) formed between the electrodes; b) forming a solution comprising an evaporable solvent and a plurality of transparent light-scattering particles; c) coating the solution on a side of the transparent electrode opposite the one or more EL unit(s); and d) drying the solution to form a light-scattering layer on the transparent electrode, wherein the ratio of the volume of light-scattering particles to the volume of the light-scattering layer is greater than 0.55 over a majority of the light-emitting area.
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18. An electroluminescent (EL) device, comprising:
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a substrate; a light-emitting area formed over the substrate and comprising first and second electrodes and one or more EL unit(s) comprising at least one light-emitting layer formed between the electrodes, wherein at least one electrode comprises a transparent electrode, the transparent electrode and EL unit(s) material having a first refractive index range; a cover located over the light-emitting area having a second refractive index and through which light from the EL unit(s) is emitted; a light-scattering layer located between the substrate and cover, comprising transparent, light-scattering particles, wherein the ratio of the volume of light-scattering particles to the volume of the light-scattering layer is greater than 0.55 over a majority of the light-emitting area, wherein either the substrate or cover is transparent and transmits light emitted from the EL unit(s); and a transparent low-index element having a third refractive index lower than each of the first refractive index range and second refractive index and located between the light-scattering layer and the transparent substrate or cover. - View Dependent Claims (19, 20)
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Specification