JVC 340 SC - Manual (Page 89)

Chapter 2—Functional Description
Model 330, 340SC and 370SC Service Manual 2-2-77
horizontally polarized light is sent through the liquid crystal layer of the ILA
®
assembly, reflected by a dielectric mirror surface, and then sent back through the
liquid crystal layer on the way out of the ILA
®
assembly.
Figure 2-20 The Hughes-JVC Image Light Amplifier
The polarized light is phase modulated, or rotated, up to 90º by the liquid crystal
layer; 45º of rotation for the first pass through, and another 45º after being
reflected by the internal mirror.
The axis of the polarized light is proportional to the brightness on the input side of
the ILA
®
assembly. For example, when the photoconductor on the input side is
not illuminated, the liquid crystal does not rotate the polarized light from the arc
lamp. Conversely, when the input side is fully illuminated, the liquid crystal
rotates the polarized light a full 90º from a horizontal direction to a vertical
direction. Ninety-nine percent (99%) of the light energy entering the ILA
®
assembly is reflected.