Image Light Amplifier Technology - Hughes JVC 220 Service Manual

Chapter 2---System Description

2.4 Image Light Amplifier Technology

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Section 2.2 explained how the various units, including the ILA
assemblies, in the Optical System work together to produce the
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image on the screen. This section focuses mainly on how the ILA
assembly itself works.
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An Image Light Amplifier (ILA ) assembly (Figure 2-18) is a
device that uses low-intensity images to modulate a high-intensity
light through a liquid crystal layer. It is the key component in
producing very bright, high resolution images from Hughes-JVC
large-screen projectors.
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Figure 2-18. The Hughes-JVC Image Light Amplifier .
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Optically, there are two sides to an ILA assembly with a light
blocking layer in the center. On the input side there is a photo-
conductive layer where the image from a CRT is focused through
a relay lens. This image is electrostatically coupled through the
light-blocking layer and mirror to a liquid crystal layer on the output
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side of the ILA assembly.
2-60 Model 220 Service Manual