Large-screen television technology (colloquially big-screen TV) developed rapidly in the late 1990s and 2000s. Prior to the development of thin-screen technologies, rear-projection television was standard for larger displays, and jumbotron, a non-projection video display technology, was used at stadiums and concerts. Various thin-screen technologies are being developed, but only liquid crystal display (LCD), plasma display (PDP) and Digital Light Processing (DLP) have been publicly released. Recent technologies like organic light-emitting diode (OLED) as well as not-yet-released technologies like surface-conduction electron-emitter display (SED) or field emission display (FED) are in development to replace earlier flat-screen technologies in picture quality.
Large-screen technologies have almost completely displaced cathode-ray tubes (CRT) in television sales due to the necessary bulkiness of cathode-ray tubes. The diagonal screen size of a CRT television is limited to about because of size requirements of the cathode-ray tube, which fires three beams of electrons onto the screen to create a viewable image. A large-screen TV requires a longer tube, making a large-screen CRT TV of about unrealistic. Newer large-screen televisions are comparably thinner.
Viewing distances
Before deciding on a particular display technology size, it is very important to determine from what distances it is going to be viewed. As the display size increases so does the ideal viewing distance. Bernard J. Lechner, while working for RCA, studied the best viewing distances for various conditions and derived the so-called Lechner distance.
As a rule of thumb, the viewing distance should be roughly two to three times the screen size for standard definition (SD) displays.