US Patent 7656085 System and method for differentiating pictures and texts

A dual emitting device includes a transparent substrate and an array of pixels. The array of pixels is disposed on the transparent substrate, and each pixel of the array includes at least one first sub-pixel and at least one second sub-pixel. The first sub-pixel includes a first OLED driven by a first TFT, and a first sheltering layer on the first OLED. The second sub-pixel includes a second OLED driven by a second TFT, and a second sheltering layer formed between the transparent substrate and the second OLED.