| 摘要 |
A prismatic lens for an overhead lighting fixture is formed from a transparent material and has a lower face composed of a plurality of arcuate surfaces arranged side-by-side. These surfaces form convex magnifying segments or lenticules in the lens. The opposite or upper face is composed of a plurality of V-shaped depressions extending downwardly from a generally flat intervening surface. The depressions are located behind and centered relative to the arcuate surfaces, whereas the intervening surfaces are positioned directly behind the junctures of adjacent arcuate surfaces. The prismatic lens diverts light rays emanating from a light source behind it primarily into zones disposed oblique to the lens so that the intensity of illumination is minimal in the reflected glare zone located directly beneath the lens and in the direct glare zone located generally to the side of the lens, but is maximum in the oblique zones located between the reflected and direct glare zones. This distribution provides the most pleasant and comfortable illumination for most visual observations performed beneath the fixture. |
