Abstract:
A dual mode light includes a housing, at least one first light emitter disposed in the housing, a plurality of second light emitters each disposed in the housing an emitter distance from the at least one first light emitter, a first shield disposed in the housing a first shield distance from the at least one first light emitter, wherein the first shield distance is less than the emitter distance, and a second shield disposed in the housing a second shield distance around the plurality of second light emitters.

Description:
[0001]    This invention was made with government support with the United States Army under Contract No. W911W6-12-D-0006. The government therefore has certain rights in this invention. 
     
    
     BACKGROUND 
       [0002]    The subject matter disclosed herein relates to lighting equipment, and more particularly, to lighting equipment for aircraft. 
         [0003]    Aircraft lighting is utilized within an aircraft to provide visibility to other aircraft and flight control personnel. Aircraft lighting can utilize multiple lighting patterns to provide desired illumination and to comply with aviation requirements. Often, aircraft lighting may require multiple lighting sources or additional complexity to provide the required lighting patterns. 
       BRIEF SUMMARY 
       [0004]    According to an embodiment, a dual mode light includes a housing, at least one first light emitter disposed in the housing, a plurality of second light emitters each disposed in the housing an emitter distance from the at least one first light emitter, a first shield disposed in the housing a first shield distance from the at least one first light emitter, wherein the first shield distance is less than the emitter distance, and a second shield disposed in the housing a second shield distance around the plurality of second light emitters. 
         [0005]    According to an embodiment, an aircraft includes an aircraft body having an aft portion, and a dual mode light disposed on the aft portion of the aircraft body, the dual mode light including a housing, at least one first light emitter disposed in the housing, a plurality of second light emitters each disposed in the housing an emitter distance from the at least one first light emitter, a first shield disposed in the housing a first shield distance from the at least one first light emitter, wherein the first shield distance is less than the emitter distance, and a second shield disposed in the housing a second shield distance around the plurality of second light emitters. 
         [0006]    Technical function of the embodiments described above includes at least one first light emitter disposed in the housing, a plurality of second light emitters each disposed in the housing an emitter distance from the at least one first light emitter, a first shield disposed in the housing a first shield distance from the at least one first light emitter, wherein the first shield distance is less than the emitter distance, and a second shield disposed in the housing a second shield distance around the plurality of second light emitters. 
         [0007]    Other aspects, features, and techniques of the embodiments will become more apparent from the following description taken in conjunction with the drawings. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0008]    The subject matter is particularly pointed out and distinctly claimed in the claims at the conclusion of the specification. The foregoing and other features, and advantages of the embodiments are apparent from the following detailed description taken in conjunction with the accompanying drawings in which like elements are numbered alike in the FIGURES: 
           [0009]      FIG. 1  is a schematic view of one embodiment of an aircraft; and 
           [0010]      FIG. 2  is an isometric view of one embodiment of a dual mode aft light for use with the aircraft of  FIG. 1 . 
       
    
    
     DETAILED DESCRIPTION 
       [0011]    Referring to the drawings,  FIG. 1  shows an aircraft  100 . In the illustrated embodiment, the aircraft  100  includes a fore portion  101 , an aft portion  102 , and at least one dual mode aft light  110 . The aircraft  100  can be any suitable aircraft, including, but not limited to fixed wing aircraft  100 , rotary wing aircraft, etc. In the illustrated embodiment, the aircraft  100  can utilize the dual mode aft light  110  to direct illumination where needed by regulations and operation requirements. In the illustrated embodiment, the dual mode aft light  110  can provide two modes of illumination, including a wide pattern  102  and a directional pattern  104 . In the illustrated embodiment, the wide pattern  102  can be an omnidirectional pattern that is at least 70 degrees wide, while the directional pattern  104  is directed in a certain direction. Advantageously, the dual mode aft light  110  can provide both patterns  102 ,  104  without using multiple lights and while minimizing part count. This can reduce the amount of wiring and weight of the aircraft  100 . 
         [0012]    Referring to  FIG. 2 , the dual mode aft light  110  is shown. In the illustrated embodiment, the dual mode aft light  110  includes a housing  111 , an inner emitter  112 , an inner shield  114 , outer emitters  116 , and an outer shield  118 . In the illustrated embodiment, the dual mode aft light  110  can provide a directional light pattern from the inner emitter  112  and a wide light pattern from the outer emitter  116 . 
         [0013]    In the illustrated embodiment, the housing  111  can contain the inner emitter  112 , an inner shield  114 , outer emitters  116 , and an outer shield  118  in a common housing  111 . The housing  111  can be formed of plastic, aluminum or any other suitable material. The housing  111  can be a circular shape or any other suitable shape. The inner emitter  112  can be centered within the housing  111 . Advantageously, the housing  111  contains both the inner emitter  112  and the outer emitters  116  to provide for dual mode operation. 
         [0014]    In the illustrated embodiment, the inner emitter  112  is located within the housing  111 . In certain embodiments, the inner emitter  112  is centered within the housing  111 . The inner emitter  112  can be any suitable light source, including, but not limited to a light emitting diode. In the illustrated embodiment, the inner emitter  112  is a solid state emitter. In certain embodiments, the inner emitter  112  can provide a light source with a virtual optical center coincident with the virtual optical center as the outer emitter  116 . Advantageously, the location of the inner emitter  112  allows for a minimal number of emitters while minimizing shadows and undesirable pattern characteristics. 
         [0015]    In the illustrated embodiment, the inner shield  114  works in conjunction with the inner emitter  112  to provide a directional light pattern. In the illustrated embodiment, the inner shield  114  is a directional shield with geometric features to provide a sharp cutoff beyond the direction of the light pattern. In the illustrated embodiment, the inner shield  114  is disposed an inner shield distance  113  from the inner emitter  112 . In certain embodiments, the inner shield distance  113  can range between 0.5 centimeters to 1.0 centimeters. In the illustrated embodiment, the inner shield  114  along with the inner emitter  112  is disposed within the outer emitters  116  to prevent or minimize negative light pattern effects of the outer emitters  116 . 
         [0016]    In the illustrated embodiment, the dual mode aft light  110  includes a plurality of outer emitters  116 . In certain embodiments, the outer emitters  116  are light sources including, but not limited to, incandescent light sources, light emitted diodes, or any other suitable light sources. In the illustrated embodiment, the outer emitters  116  are radially disposed from the center of the dual mode aft light  110 . In the illustrated embodiment, the outer emitters  116  are formed to create a virtual optical center that is coincident with the virtual optical center of the inner emitter  112 . 
         [0017]    In the illustrated embodiment, the outer emitters  116  can be disposed an outer emitter distance  115  from the center of the inner emitter  112 . In certain embodiments, the outer emitter distance  115  is between 0.5 centimeters and 1 centimeter. In certain embodiments, the outer emitter distance  115  can be greater than 1 centimeter. In the illustrated embodiment, the outer emitters  116  are disposed radially outside of the inner shield  114  to minimize the light pattern created by the inner shield  114  during operation of the outer emitters  116 . The outer emitter distance  115  allows the outer emitters  116  to “see around” the inner shield  114 . Advantageously, the position of the outer emitters  116  eliminates or minimizes the need for a focusing optic, additional optical power, additional housings, additional components, etc., preventing additional complexity. Further, by positioning the outer emitters  116  outside of the inner shield  114  location, the outer emitters  116  are not required to be positioned in a precise manner. 
         [0018]    In the illustrated embodiment, the light emitted from the outer emitters  116  is formed into the output pattern by the outer shield  118 . The outer shield  118  is disposed an outer shield distance  117  from the outer emitters  116 . In the illustrated embodiment, the outer shield distance  117  can be 3.5 centimeters to 4 centimeters from the outer emitters  116 . In the illustrated embodiment, the outer shield  118  is disposed outside or around the plurality of outer emitters  116 . In the illustrated embodiment, the outer shield  118  in conjunction with the outer emitters  116  can provide an omnidirectional light pattern of approximately 70 degrees. In other embodiments, the outer shield  118  in conjunction with the outer emitters  116  can provide an omnidirectional light pattern ranging between 60 to 80 degrees. Advantageously, the dual mode aft light  110  can provide the omnidirectional light pattern without requiring tight tolerances or additional equipment. 
         [0019]    In the illustrated embodiment, the relationship between the inner shield distance  113  and the outer shield distance  117 , along with the relationship between the inner emitter  112 , the inner shield  114 , the outer emitters  116 , and the outer shield  118  allows the directional pattern created by the inner emitter  112  and the inner shield  114  to coexist with the omnidirectional pattern created by the outer emitters  116  and the outer shield  118  with minimal complication. In certain embodiments, the ratio between the inner shield distance  113  and the outer shield distance  117  is between 0.125 and 0.285. Advantageously, this ratio allows for both modes and output patterns to be contained in a single housing  111 . 
         [0020]    The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the embodiments. While the description of the present embodiments has been presented for purposes of illustration and description, it is not intended to be exhaustive or limited to the embodiments in the form disclosed. Many modifications, variations, alterations, substitutions or equivalent arrangement not hereto described will be apparent to those of ordinary skill in the art without departing from the scope and spirit of the embodiments. Additionally, while various embodiments have been described, it is to be understood that aspects may include only some of the described embodiments. Accordingly, the embodiments are not to be seen as limited by the foregoing description, but are only limited by the scope of the appended claims.