Circularly polarized multi-bandpass interference contrast enhancement filter

DETAILED DESCRIPTION It is a object of the present invention to provide a light filter which enhances the contrast of visual display devices.
It is a feature of the present invention to provide a circular polarizer in conjunction with a multi-bandpass interference filter.
It is an advantage of the present invention to greatly reduce the amount of ambient light which is reflected back from the visual display device toward the viewer while only slightly diminishing the intensity of the light generated by the visual display device.
It is another object of the present invention to provide a light filter which selectively passes several narrow bands of visible light.
It is another feature of the present invention to match the several passbands of the multi-bandpass interference filter with the several wavelengths of the emissive display device.
It is another advantage of the present invention to provide for a high degree of transmission of the desired display emission while concomitantly providing for a great reduction in light from all other sources.
The present invention provides a contrast enhancement filter designed to fulfill the aforementioned needs, satisfy the earlier propounded objects, contain the above described features and produce the previously stated advantages.
The invention is carried out by a "Double Polarized" reflection reduction apparatus, in the sense that incoming ambient light is polarized before it strikes the display phosphors and is again polarized after reflection from the phosphors.
Accordingly, the present invention relates to a contrast enhancement filter utilizing a multiple bandpass filter in conjunction with a circular polarizer.