JVC Model 200 service manual Simplified image/optical path

Chapter 2---System Description

High intensity light from a Xenon Arc Lamp is applied, through a prism (where it is polarized), to the output side of the ILA® assembly where the liquid crystal layer is located. The polarized light passing through the liquid crystal is modulated (changing the polarity of the light waves), in accordance with whatever image is on the input side of the ILA® assembly.

The axis of the polarized light is proportional to the brightness on the input side of the ILA® assembly. When the photoconductor on the input side is not illuminated, the liquid crystal does not rotate the polarized light from the Arc Lamp. No light passes through the prism and the screen is dark. When the input side is fully illuminated, the liquid crystal rotates the polarized light 90° from a horizontal direction to a vertical direction. Ninety nine percent (99%) of the light entering the ILA® assembly is reflected and passes through the prism resulting in a white screen.

The modulated high-intensity light is reflected back out of the output side of the ILA® assembly, through the Prism and the Projection Lens and onto the screen. (see Figure 2-19).

Figure 2-19.Simplified image/optical path.

2-64 Model 200 Service Manual