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The LCDs used for projection systems are usually small reflective or transmissive panels set off by a bright arc lamp source. A series of lenses enlarges the reflected or transmitted image and sends it onto a screen. In front-projection systems the LCD is situated on the same area of the screen as the viewer, but in rear-projection systems the screen is lit up from behind. Projectors of higher expense and performance can have three separated LCD panels, casting separate red, green, and blue images that come together to reflect a coloured picture on the screen.

The increasing need for video displays has had a particular emphasis on the switching speed of liquid crystals. This has led to the invention of devices employing smectic liquid crystals, some kinds of which emit a quicker electro-optical response than nematic liquid crystals. The surface-stabilized ferroelectric liquid crystal (SSFLC) display is at this point the most complex smectic device. In it the liquid crystal molecules are cast in layers perpendicular to the substrate planes, which are distanced by one or two micrometres, and throughout the layers the molecules are tilted, as illustrated in the figure. The host liquid crystal possesses optically active molecules, and a slight turn up of the optical activity and the angle 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 within the plane of the layers. Therefore, there is a permanent charge separation throughout the liquid crystal layer in the SSFLC, and its sign is directly coupled 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 by doing so reverse the tilt direction of the molecules. The consequential change in optical properties can create a change from light to dark when one or more polarizers are used.

SSFLC devices have been marketed for larger passive-matrix presentations, but their expensiveness and intricacy has hindered them from making any great movement on the market. Small transmissive and reflective active-matrix SSFLC displays, however, have displayed some possibility for use as parts in projection systems or as viewfinders in digital cameras. Their speedy reacting allows them to be used in time-sequential colour systems, in which expensive colour filters are replaced with a coloured backlight that flashes red, green, and blue in fast pace (around 100 cycles a second). For example, the liquid crystal may be switched to a transmissive state for the red and green periods and then 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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