Direct view lighting system with constructive occlusion

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention utilizes principles of constructive occlusion (diffuse reflectivity in a mask and cavity structure) together with direct-view illumination of selected regions, to tailor radiation intensity distribution to the requirements of certain special applications.
The direct illumination provides high intensity illumination for certain desired regions, for example at elevation angles near the horizon or directed to edges of a wide planar area to be illuminated.
Some light from the system source(s) reflects and diffuses within the volume between the mask and the cavity.
The mask constructively occludes the aperture of the cavity.
The parameters of the mask and the cavity are selected such that the reflected light emerging from between the mask and the cavity provides a desired illumination, for example at a much lower intensity, for regions not covered by the direct illumination.
In an embodiment wherein the direct illumination covers angles near the horizon, for example, the constructive occlusion provides lower intensity illumination in regions at higher elevation angles.
The inventive systems may provide a variety of other intensity distributions, for example, to facilitate a uniform distribution over a particularly wide planar target surface.
The combination of direct view illumination with constructive occlusion enables the designer to precisely tailor the illumination system to the needs of a particular application.
As a result, the designer need not over-radiate one area to meet the requirements for radiation in another area.
Consequently, the system provides particularly high efficiencies and enables the use of lower power and/or smaller or fewer sources of radiant energy.
The illuminating systems are relatively simple in design, making the inventive devices relatively cheap to manufacture as well as more durable than prior systems designed to meet similar application requirements.
The invention also enables the use of more modern, dependable sources, such as LEDs