Non-mesh conforming filter for a video display unit

DETAILED DESCRIPTION It is an object of the present invention to provide a conforming filter for a VDU without the use of conductive mesh.
It is another object of the present invention to provide a conforming filter for a VDU on a substrate which is rigid enough to be coated as a flat sheet but sufficiently flexible that it may be made to conform to the curvature of a curved faceplate by applying pressure to a perimeter region of the filter when the filter is held against the faceplate.
It is a further object of the invention to produce a conforming filter which may be easily fitted to a VDU without the need for special tools or special skills.
In one preferred embodiment, the present invention comprises a transparent plastic substrate.
The substrate is coated on at least one surface with a filter coating having at least anti-reflective properties.
The filter coating may also include at least one electrically conductive layer and may also attenuate visible light.
A filter coating may also be deposited on another surface of the substrate.
The substrate is preferably rigid enough to have filter coatings applied when it is in the form of a flat sheet, yet flexible enough that the filter may be caused to substantially conform to the curvature of a CRT faceplate by placing the filter against the faceplate and applying pressure around a perimeter region of the filter.
The desired properties of the substrate are obtained when the thickness of the substrate is between about 0.
8 and 1.
2 millimeters (mm).
Plastics such as acrylics, polyesters, and polycarbonates may be suitable substrate materials.
Polycarbonate is the preferred substrate material.
A polycarbonate substrate is preferably about 1.
0 mm thick.
The filter may be retained in a conforming position by a bezel defining a viewing aperture on the CRT faceplate.
The filter may also be retained in position by adhesive strips around the perimeter region of the filter.
The adhesive strips may be transparent.
The filter may be designed to attenuate light through the use of light attenuating filter coatings, light attenuating material incorporated in the substrate, or both