Replaceable single LED lamp for runway sign

摘要

A replacement lamp for an airport runway sign. Light is produced by a linear array of white-light LEDs. A cylindrical lens is mounted longitudinally adjacent to the LEDs, and collects a central portion of the light emitted from the LEDs. A pair of inclined surfaces extend from the lateral edges of the LEDs to respective lateral edges of the cylindrical lens. The inclined surfaces have a rough surface texture and reflect light diffusely. The inclined surfaces collect a peripheral portion of the light emitted from the LEDs, and direct the reflected light toward the cylindrical lens. The LEDs, cylindrical lens and inclined surfaces are all mechanically supported by a heat sink. The replacement lamp is placed into a runway sign near its top or bottom edge, and illuminates both viewing surfaces of the runway sign simultaneously without a diffuser.

主权项

1. A replacement light module (1), comprising:
a heat sink (5) elongated along a lateral direction (X), a plurality of LEDs (2) supported by the heat sink (5), the LEDs (2) being spaced apart in the lateral direction (X), each LED (2) emitting light into an angular distribution centered around a longitudinal axis (A); the longitudinal axes (A) all being parallel to a vertical direction (Z); a cylindrical lens (4) elongated along the lateral direction (X) and centered along the longitudinal axes (A), the cylindrical lens (4) receiving a central portion of the light emitted from the LEDs (2) and transmitting the central portion therethrough, the cylindrical lens (4) altering the angular path of the transmitted light along a forward direction (Y) but not along the lateral direction (X); and a pair of elongated, inclined surfaces (3) on the heat sink (5), each inclined surface (3) being elongated along the lateral direction (X) and being parallel to the lateral direction (X), each inclined surface extending from a position proximate a lateral edge of the LEDs (2) to a position proximate a lateral edge of the cylindrical lens (4), the pair of inclined surfaces (3) opening away from the LEDs (2) toward the cylindrical lens (4), each inclined surface (3) receiving a peripheral portion of the light emitted by the LEDs (2), each inclined surface (3) defining a respective reflective surface that reflects the peripheral portion toward the cylindrical lens (4); wherein the cylindrical lens (4) has a light output that includes light from both the central portion and the peripheral portion of the light emitted from the LEDs (2); wherein the light output of the cylindrical lens (4) has two angular peaks on opposite sides of the vertical direction (Z), has a value below the peak values along the vertical direction (Z), and has decreasing values at angles above the angular peaks; wherein the angular peaks are at plus four degrees and minus four degrees away from the vertical direction (Z); and wherein in a cross-section taken perpendicular to the lateral axis (X), the cylindrical lens (4) is plano-convex, with a planar incident face (6) facing the LEDs (2) and a convex exiting face (7) facing away from the LEDs (2), wherein the convex exiting face (7) includes a concave dimple at its center.