LED based trough designed mechanically steerable beam traffic signal

摘要

An area array of LEDs (46) encompassed within a single reflector housing (302) which can be selectively masked (320) to mechanically adjust the viewing angle of the light generated therefrom. The area array of LEDs are disposed within a cavity of a housing forming a trough which is covered by a holographic diffuser. A mask is selectively positionable and attached to the top of the diffuser to mask a portion of the LEDs, and may be secured in position using Velcro(R) material. By selectively masking the portions of LEDs, the beam angle from the lens can be selectively adjusted. Multiple colored LEDs are provided such that more than one color light beam can be generated from the single signal housing. The mask selectively adjusts both the angle and shape of the beam ultimately transmitted by the associated Fresnel lens.