Masking of light valve spill light
AssigneeGeneral Electric Company
InventorThomas T. True
Life of this patent
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Abstract
Improved masking of light valve spill light is disclosed for Schlieren dark field light valves. The mask is deposited on the interior or exterior of the output window (58) and comprises an opaque area (90) which surrounds a transparent window area (91). The mask is characterized by a zone (92) of graduated density from transparent to opaque. The effect of the graduated density zone is to eliminate spurious light diffracted by the edges of the mask and significantly improves the performance of the light valve.
Claims7
In a light valve of the Schlieren dark field type having a deformable light modulating control layer closely spaced from an output window, an electron gun and deflection assembly for generating and scanning an electron beam onto said deformable light modulating control layer in a raster to deform the surface of said layer, and a source of light for projecting light through an area of the raster scanned onto said deformable light modulating control layer, the improvement comprising a mask formed on said output window in optical alignment with and having dimensions related to said raster, said mask having edges formed with a variable density from transparent to opaque over a space sufficient to contain diffracted light within a "guard band" of the Schlieren dark field optics.
Dependencies are inferred from the claim text.