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The LCDs built in projection systems are most often small reflective or transmissive panels lit up by a powerful arc lamp source. A number of lenses expands the reflected or transmitted image then displays it on the screen. For front-projection systems the LCD is situated on the side of the screen as the viewer, while in rear-projection systems the screen is lit up from behind. Projectors of higher expense and performance may have three distinct LCD panels, forming separate red, green, and blue images that blend to reflect a coloured display on the screen.

The increase in demand for visual presentations has put a growing emphasis on the switching speed of liquid crystals. This has necessitated the manufacture of items utilizing smectic liquid crystals, particular kinds of which emit a faster electro-optical response than nematic liquid crystals. The surface-stabilized ferroelectric liquid crystal (SSFLC) display is currently the most complex smectic device. Inside it the liquid crystal molecules are cast in perpendicular layers to the substrate planes, which are differentiated by one or two micrometres, and within the layers the molecules are on a slant, as illustrated in the figure. The host liquid crystal possesses optically active molecules, and a subtle turn up of the optical activity and the shape of the molecules is the appearance of a permanent charge separation, or ferroelectric dipole, likeable to the ferromagnetic dipole of a magnet. The direction of this dipole is perpendicular to the tilt direction of the molecules and within the plane of the layers. Thus, there is a permanent charge separation through the liquid crystal layer in the SSFLC, and its sign is directly paired up to the tilt direction of the molecules. An applied voltage of the correct sign can reverse the direction of this dipole in tens of microseconds and so reverse the tilt direction of the molecules. The corresponding change in optical properties can create a change from light to dark when one or more polarizers are used.

SSFLC devices have been publicized for big passive-matrix presentations, but their cost and intricacy has hindered them from enjoying any significant effect on the market. Small transmissive and reflective active-matrix SSFLC displays, however, have shown some probability for use as elements in projection systems or as viewfinders in digital cameras. Their quick response allows them to be made use of in time-sequential colour systems, in which dear colour filters are removed for a coloured backlight that flashes red, green, and blue in fast pace (about 100 cycles a second). For example, the liquid crystal might be switched to a transmissive state between the red and green periods but to a nontransmissive state for the blue period, displaying the upshot that the eye sees an average of red and green light, or the colour yellow.

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