rear-projection TV - Computer Definition
A large-screen TV set that has employed one of several technologies for generating the image. Rear-projection TVs (RPTVs) were developed to extend the size of a TV screen beyond the CRT TV, which for all practical purposes reached 36". Introduced in the 1970s and very popular throughout the 1980s and 1990s, at the end of 2012, Mitsubishi, the only remaining vendor of RPTVs, ceased production of its DLP-based 82" and 92" sets. Although always bulky, the RPTV was shallower than any CRT would have been at that size, because the image is projected through a series of lenses and mirrors that flip it up and over rather than straight toward the screen as with a CRT. They Started with CRT Guns The first sets used three 7" CRTs to generate red, green and blue light. Newer technologies used tiny microdisplay panels that resulted in even shallower sets, although nowhere near as thin as plasma and LCD TVs. A Lot of TV for the Money Early rear-projection systems suffered from a narrow viewing angle. Because the screen itself is a lens, standing up or moving off to the side changes the brightness of the image for the viewer. However, newer sets had wider viewing angles, and although perhaps never as visually dazzling as plasma, they were the only large-screen TVs available for many years. See viewing angle. Rear Vs. Front Projection Rear projection systems have a fixed screen size, whereas front projectors can change their screen size by replacing the external screen and repositioning the unit (see front-projection TV). See microdisplay, plasma, LCD and video/TV history.