Filter assembly

An optical filter assembly for use on a visual display device comprising:

• a frame assembly defining a viewing aperture;
• said frame assembly being mountable on a visual display device such that said aperture is in registry with a visual display screen of the visual display device;
• an optical filter for coveting said aperture, and thereby the visual display area;
• said frame assembly includes a plurality of sidewalls which extend a distance sufficient for reducing the passage of room light to behind the optical filter;
• means on said frame assembly for releasably holding the optical filter to said frame assembly;
• and, means associated with said frame assembly for spacing the optical filter from the display screen;
• said spacing means includes protrusion means integral with said frame assembly for contacting the display screen for physically spacing the mounted optical filter from the display screen;
• and, means on said frame assembly for centering the optical filter when the latter is being mounted to said frame assembly;
• wherein said means for centering said filter includes a plurality of ribs which act to engage and guide the optical filter into registry with said aperture.