Replaceable Single LED Lamp for Runway Sign

• US 20140198500A1
• Filed: 01/17/2013
• Published: 07/17/2014
• Est. Priority Date: 01/17/2013
• Status: Active Grant

• Current Assignee: OSRAM Sylvania Inc. (Ams-Osram AG)
• Original Assignee: OSRAM Sylvania Inc. (Ams-Osram AG)
• Inventors: Tessnow, Thomas, Albright, Kim, Boyd, Ronald E. Jr., Plaza, Aaron
• Granted Patent: US 9,512,984 B2
• Time in Patent Office: Days
• US Class Current: 362/245
• CPC Class Codes: B64D 2203/00 Aircraft or airfield lights using LEDs
• CPC Class Codes: B64F 1/20 Arrangement of optical beacons
• CPC Class Codes: F21S 4/20 with light sources held by or within elongate supports
• CPC Class Codes: F21V 13/04 the elements being reflectors and refractors for vehicle rear lights F21S43/40
• CPC Class Codes: F21V 29/763 the planes containing the fins or blades having the direction of the light emitting axis
• CPC Class Codes: F21V 5/043 the lens having cylindrical faces, e.g. rod lenses, toric lenses
• CPC Class Codes: F21V 7/005 with an elongated shape to cooperate with linear light sources
• CPC Class Codes: F21Y 2103/10 comprising a linear array of point-like light-generating elements
• CPC Class Codes: F21Y 2115/10 Light-emitting diodes [LED]
• CPC Class Codes: G02B 19/0009 having refractive surfaces only
• CPC Class Codes: G02B 19/0066 in the form of an LED array
• CPC Class Codes: G09F 13/04 Signs, boards or panels, illuminated from behind the insignia
• CPC Class Codes: G09F 13/0404 the light source being enclosed in a box forming the character of the sign
• CPC Class Codes: G09F 13/0422 Reflectors
• CPC Class Codes: G09F 19/226 External wall display means; Facade advertising means

Abstract

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.

Claims

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); and

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.

2. The replacement light module (1) of claim 1, wherein when the light module (1) is installed in a runway sign (10), the angular peaks coincide with edges of respective viewable faces (11) of the runway sign (10) distal from the light module (1).

3. The replacement light module (1) of claim 1, wherein the angular peaks are at plus four degrees and minus four degrees away from the vertical direction (Z).

4. The replacement light module (1) of claim 1, wherein the inclined surfaces (3) are flat.

5. The replacement light module (1) of claim 1, wherein the inclined surfaces (3) are diffuse reflectors.

6. The replacement light module (1) of claim 1, wherein the LEDs (2) are white-light LEDs.

7. The replacement light module (1) of claim 1, wherein the reflective surfaces and the cylindrical lens (4) are devoid of wavelength conversion material.

8. The replacement light module (1) of claim 1, 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).

9. The replacement light module (1) of claim 8, wherein the convex exiting face (7) includes a concave dimple at its center.

10. The replacement light module (1) of claim 1, wherein the heat sink (5) mechanically supports the cylindrical lens (4).