The LCDs used for projection systems are most often small reflective or transmissive panels lit by a powerful arc lamp source. A number of lenses expands the reflected or transmitted image and then sends it on the screen. In front-projection systems the LCD is placed 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 cost and capacity might have three separate LCD panels, reflecting separate red, green, and blue images that combine to make a coloured image on the screen.

The increasing demand for film displays has put a growing emphasis on the switching speed of liquid crystals. This has required the manufacture of objects employing smectic liquid crystals, some types of which emit a faster electro-optical response than nematic liquid crystals. The surface-stabilized ferroelectric liquid crystal (SSFLC) display is in the current day the most developed smectic device. In it the liquid crystal molecules are arranged in perpendicular layers to the substrate planes, which are differentiated by one or two micrometres, and inside the layers the molecules are tilted, as shown in the figure. The host liquid crystal holds optically active molecules, and a subtle outcome of the optical activity and the angle 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 has to be 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 right sign can reverse the direction of this dipole in tens of microseconds and hence reverse the tilt direction of the molecules. The respective change in optical properties can effect a change from light to dark if or when one or more polarizers are utilised.

SSFLC devices have been commercialized for big passive-matrix displays, but their cost and complexity has impeded them from enjoying any remarkable impact on the market. Small transmissive and reflective active-matrix SSFLC displays, however, have some possibility for use as parts in projection systems or as viewfinders in digital cameras. Their fast reaction 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 rapid succession (around 100 cycles a second). For example, the liquid crystal might be switched to a transmissive state between the red and green periods and then to a nontransmissive state in the blue period, displaying the outcome that the eye sees an average of red and green light, or the colour yellow.

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