US Patent 7586560 Display using light guide and refractive index control

Some embodiments provide a device including a first material associated with a controllable refractive index, a second material associated with a first refractive index, and a third material disposed between the first material and the second material, the third material being substantially transparent to a plurality of visible light wavelengths and being associated with a second refractive index greater than the first refractive index. Devices according to some embodiments may be employed as a display in a laptop computer, a desktop computer, a personal digital assistant, a minicomputer, a projection television, a front projector, etc.