An LED device includes a plurality of LED dies, a plurality of lens, a diffuser plate and a collimator lens. The collimator lens is positioned between the diffuser plate and the lens. The collimator lens includes a plurality of fresnel lenses. A focus of each fresnel lens is equal to a distance between a plane where the fresnel lens places and a light outputting surface of the LED die. Light emitted from the LED dies is adjusted to collimator light and striking perpendicularly into the diffuser plate.

现有的发光二极管装置，例如发光二极管背光模组通常采用多个发光二极管芯片搭配透镜以得到面光源。然而发光二极管芯片的光线出射角度大约为120°，且正向出射光线的光强大于侧向出射光线的光强，因此从正向视角看去会看到具有较大光强的正向光线形成的亮点。业界通常会采用一扩散板使发光二极管芯片的发散角扩大以获得一较均匀的光场分布，如何在保持扩散板的扩散能力的同时不对发光效率产生影响成为了业界亟待解决的问题。