| 摘要 |
<p>A lens that angularly redistributes light from an LED is disclosed. The desired illuminance (power per area) pattern for an LED/lens combination has a relatively flat center, a knee, and a gradual tail. By overlapping adjacent combinations' tails, the resulting illuminance pattern may be generally uniform, with relatively loose tolerances on LED/lens placement and performance. The lens has a proximal face with a concave spherical indentation with its center at the light source. The lens's distal face has a "center thickness" (CT) on- axis, a peak thickness away from a longitudinal axis of about 1.0 to 1.2 times the CT, a radius at which the peak thickness occurs of about 0.5 to 1.0 times the CT, a radius at which the thickness returns to the CT of about 1.1 to 1.5 times the CT, and a radius (maximum lateral extent) of the lens of about 1.6 to 1.9 times the CT.</p> |
