ABSTRACT
Detectors, light sources, transistors, and wavefront-control devices are the building blocks of image sensors and displays. First, detectors generate signals by interacting with radiation. For example, a photodiode converts a visible photon to an electron–hole pair via photoelectric effect. A scintillator converts X-ray to visible photons. Second, light sources are used both for illuminating objects and for displaying images. For example, light-emitting diodes convert electric current to a flux of visible photons. Third, transistors control flow of electric charges that carry image information. Metal–oxide–semiconductor field-effect transistors are at the heart of integrated circuits as well as image sensors and displays. Thin-film transistors are used in large-area applications such as televisions and X-ray imagers. Finally, wavefront-control devices manipulate photons for acquiring and displaying images. They include various optical films, liquid crystal devices, and digital micromirror devices.
