The LCDs built in projection systems are usually small reflective or transmissive panels set off by a forceful arc lamp source. A number of lenses enlarges the reflected or transmitted image and sends it on the screen. With front-projection systems the LCD is set on the side of the screen as the viewer, although in rear-projection systems the screen is illuminated from behind. Projectors of greater expense and capacity sometimes utilise three discrete LCD panels, forming separate red, green, and blue images that blend to create a coloured display on the screen.

The increasing demand for video presentations has granted a growing emphasis on the switching speed of liquid crystals. This has led to the manufacture of objects employing smectic liquid crystals, certain ones of which have a better electro-optical response than nematic liquid crystals. The surface-stabilized ferroelectric liquid crystal (SSFLC) display is at this point the most developed smectic device. In it the liquid crystal molecules are arranged in perpendicular layers to the substrate planes, which are separated by one or two micrometres, and inside the layers the molecules are tilted, as displayed in the figure. The host liquid crystal possesses optically active molecules, and a subtle turn up of the optical activity and the slant of the molecules is the presence 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 in the plane of the layers. Thus, there is a permanent charge separation across 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 by doing so reverse the tilt direction of the molecules. The resultant change in optical properties can effect a change from light to dark if or when one or more polarizers are employed.

SSFLC devices have been publicized for bigger passive-matrix presentations, but their high cost and detail has stopped them from making any significant effect on the market. Small transmissive and reflective active-matrix SSFLC displays, however, display some probability for use as aspects in projection systems or as viewfinders in digital cameras. Their immediate response allows them to be utilised in time-sequential colour systems, in which high cost colour filters are emulated with a coloured backlight that flashes red, green, and blue in fast speed (about 100 cycles every second). For example, the liquid crystal may be switched to a transmissive state between the red and green periods but then to a nontransmissive state for the blue period, with the result that the eye sees an average of red and green light, or the colour yellow.

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