Color mixing aviation anti-collision light

Abstract

A dual-color aviation Anti Collision Light (ACL) has a first set of LEDs that emit a substantially white beam of light and a second set of LEDs that emit a substantially red beam of light. The ACL can be operated in a first mode in which the red LEDs are excited by themselves so that the ACL produces a red beam of light In a second mode, the white LEDs and the red LEDs are excited simultaneously to produce a white beam of light having a chromaticity within the definition of Aviation White. Operating the red LEDs in the white mode has two synergistic effects. First, the red LEDs augment the luminous output of the white LEDs so that fewer white LEDs are required, thus saving cost and space. Second, the red LEDs shift the chromaticity of total light output toward the red region. This has the effect of compensating for the tendency of the white LEDs to become greener with age.

What is claimed is: 
     
         1 . An aircraft light comprising:
 a housing having a flange adapted to be mounted to the exterior surface of an aircraft;   a first plurality of Light Emitting Diodes mounted to the housing, the first plurality of Light Emitting Diodes capable of being excited to emit a substantially white beam of light;   a second plurality of Light Emitting Diodes mounted to the housing, the second plurality of Light Emitting Diodes capable of being excited to emit a substantially red beam of light;   the first and second plurality of Light Emitting Diodes being configured to operate together in a first mode to produce a first beam of light having a chromaticity within the region defined by the following formula on the 1931 C.I.E. Chromaticity Diagram,
   x≧0.300 and x≦0.540;
 
     y≧ ( x− 0.040; or y0−0.010), whichever is the smaller; and
 
     y≦ ( x+ 0.020) and y≦0.636−0.400 x;  
 
   Where y0 is the y coordinate of the Planckian radiator for the value of x considered; and 
   the second plurality of Light Emitting Diodes being configured to operate in a second mode independent of the first plurality of Light Emitting Diodes to produce a second beam of light having a chromaticity within the region defined by the following formula on the 1931 C.I.E. Chromaticity Diagram,
   y≦0.335; and
 
   z≦0.002.
 
   
     
     
         2 . The aircraft light of  claim 1 , wherein:
 the beam of light emitted by the first and second plurality of Light Emitting Diodes operating in the first mode is at least twice the intensity of the red beam of light emitted by the second plurality of Light Emitting Diodes operating in the second mode.   
     
     
         3 . The aircraft light of  claim 2 , wherein:
 the beam of light emitted by the first and second plurality of Light Emitting Diodes operating in the first mode has an intensity of at least 1000 candela and the beam of light emitted by the second plurality of Light Emitting Diodes operating in the second mode has an intensity of less than 500 candela.   
     
     
         4 . The aircraft light of  claim 1 , wherein:
 at least 1% of the intensity of the beam of light emitted by the first and second plurality of Light Emitting Diodes operating in the first mode is a substantially red beam of light produced by the second plurality of Light Emitting Diodes.   
     
     
         5 . The aircraft light of  claim 1 , wherein:
 at least 4% of the intensity of the beam of light emitted by the first and second plurality of Light Emitting Diodes operating in the first mode is a substantially red beam of light produced by the second plurality of Light Emitting Diodes.   
     
     
         6 . The aircraft light of  claim 1 , wherein:
 the first plurality of Light Emitting Diodes by themselves produce a beam of light having a chromaticity outside the region defined by the following formula on the 1931 C.I.E. Chromaticity Diagram,
   x≧0.300 and x≦0.540;
 
     y≧ ( x− 0.040; or  y 0−0.010), whichever is the smaller; and
 
     y≦ ( x+ 0.020) and  y≦ 0.636−0.400 x;  
 
   Where y0 is the y coordinate of the Planckian radiator for the value of x considered 
   
     
     
         7 . The aircraft light of  claim 1 , wherein:
 the first and second plurality of Light Emitting Diodes are configured to produce a flashing strobe light when operating in the first mode.   
     
     
         8 . The aircraft light of  claim 1 , wherein:
 the second plurality of Light Emitting Diodes are configured to produce a flashing strobe light when operating in the second mode.   
     
     
         9 . The aircraft light of  claim 1 , wherein:
 the first and second plurality of Light Emitting Diodes are arranged along a common plane.