image light amplifier (projector) (ILA)
The principle of the ILA projector, Image Light Amplifier (ILA), is based on a light valve with light amplification. The central ILA light amplifier modulates polarized light with image information. The ILA chip is translucent from one side and opaque and reflective from the other.
The light-transmissive side of the ILA chip consists essentially of a photoelectric semiconductor layer onto which a high- resolution image is projected by a cathode-ray tube as a charge image. This charge image is electrostatically transferred from the semiconductor layer to the liquid crystal layer via the light-tight layer, aligning the liquid crystals according to the charge image.
The opaque side consists of a protective glass behind which the liquid crystal layer and a dielectric layer are located. The latter is mirrored and reflects the incident light. This side of the ILA light amplifier is illuminated by the light from a projector lamp, which has previously been filtered by polarization into an oscillation plane.
This polarized light, as it passes through the liquid crystal layer, is phase modulated with the image information. Then the polarized and phase modulated light hits the dielectric mirror from which it is reflected and passes the liquid crystal layer one more time and is also phase modulated one more time. The reflected and modulated light from the ILA light amplifier passes through the polarization splitter( PBS), which allows only vertically polarized light to pass in this direction, and is projected onto the screen via the projection lens.
Like other projection technologies, ILA projectors with one ILA chip are also available as three-chip projectors, in which the three primary colors are generated via dichroic filters. A further development of ILA technology is Direct-Drive Image Light Amplifier( D-ILA).
ILA projectors have sophisticated technology, they are light-intensive, feature high contrast and resolution that can exceed Super-XGA( SXGA), Ultra-XGA( UXGA) and Super UXGA( SUXGA), and are suitable for large screen projection.