The LCDs utilised for projection systems are usually small reflective or transmissive panels lit by a bright arc lamp source. A line of lenses magnifies the reflected or transmitted image and sends it on a screen. With front-projection systems the LCD is placed on the same side of the screen as the viewer, but in rear-projection systems the screen is set off from behind. Projectors of higher cost and performance may be found with three distinct LCD panels, reflecting separate red, green, and blue images that blend to make a coloured picture on the screen.

The growth in demand for visual displays has granted a growth in emphasis on the switching speed of liquid crystals. This has led to the development of devices employing smectic liquid crystals, particular kinds of which have a better electro-optical response than nematic liquid crystals. The surface-stabilized ferroelectric liquid crystal (SSFLC) display is currently the most progressive smectic device. Inside it the liquid crystal molecules are managed in layers perpendicular to the substrate planes, which are distanced by one or two micrometres, and throughout the layers the molecules are tilted, as shown in the figure. The host liquid crystal has optically active molecules, and a scarcely perceptible outcome of the optical activity and the slant of the molecules is the presence of a permanent charge separation, or ferroelectric dipole, similar to the ferromagnetic dipole of a magnet. The direction of this dipole is perpendicular to the tilt direction of the molecules and throughout the plane of the layers. Thus, there exists a permanent charge separation across the liquid crystal layer in the SSFLC, and its sign is directly partnered to the tilt direction of the molecules. An applied voltage of the corresponding sign can reverse the direction of this dipole in tens of microseconds and in so doing reverse the tilt direction of the molecules. The consequential change in optical properties can make a change from light to dark in the case that one or more polarizers are used.

SSFLC devices have been marketed for larger passive-matrix displays, but their expense and complexity has impeded them from enjoying any significant progress on the market. Small transmissive and reflective active-matrix SSFLC displays, however, show some promise for use as elements in projection systems or as viewfinders in digital cameras. Their fast response allows them to be employed in time-sequential colour systems, in which dear colour filters are replaced with a coloured backlight that flashes red, green, and blue in fast pulsing (approximately 100 cycles every second). For example, the liquid crystal can be switched to a transmissive state for the red and green periods then to a nontransmissive state during the blue period, creating the result that the eye sees an average of red and green light, or the colour yellow.

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