Abstract:
An aircraft-mounted camera system includes a camera and a housing that conforms to the topography of an aircraft. A camera is attached to a small window that includes a conductive-film heating element. The camera and window are seated within the housing receptacle, and held in place by an epoxy filler that also serves to insulate the camera from vibration. The camera system is attached to the outer body of the aircraft using a backing plate. The aircraft-mounted camera system may be easily manufactured at low cost, and can serve several functions, including pilot aircraft observation and passenger entertainment when connected to an in-cabin display.

Description:
FIELD OF THE INVENTION  
         [0001]    The present invention relates to video cameras and, more particularly, to video cameras that are sealed to the environment. The cameras of the present invention are particularly beneficial when mounted to the surface of an aircraft where the cameras are subject to a harsh environment. The present invention also relates to methods for manufacturing such cameras and systems for their use.  
         BACKGROUND OF THE INVENTION  
         [0002]    Aircraft-mounted camera systems have several uses. For example, they may be used to provide in-flight entertainment to cabin passengers. Cabin passengers may want to see the same view as their pilot, but are prohibited because cabin windows are small, views are often obstructed by aircraft structures, and access to cabin windows is often restricted by seating configurations. Cabin passengers may realize a more enjoyable flight by watching a display screen that projects an unobstructed, wide-angle forward view of the flight path. Other uses of aircraft-mounted camera systems include safety, security, and surveillance.  
           [0003]    Mounting a camera on the outside surface of an aircraft presents several environmental challenges. One of these challenges is temperature extremes. Environmental temperature generally drops as altitude increases. At high altitudes, temperatures may become extremely cold. Camera mounting systems must be designed to prevent fogging and crystallization of vapor on the camera lens or window as a result of temperature change.  
           [0004]    Another challenge is vibration. Vibration may be caused by aircraft propulsion systems, turbulence, or the friction and drag forces exerted by high-speed travel. Camera mounting systems must be designed to prevent the camera from being exposed to excessive vibrations that could impair image quality. The mounting system must also be aerodynamic, and seamlessly integrate with the aircraft body in order to maintain aircraft performance and minimize drag.  
           [0005]    Camera mounting apparatus found in the prior art tend to be complex and involve numerous moving parts. As a result, they contain expensive components and require complex and, therefore, expensive manufacturing methods.  
           [0006]    Accordingly, there is a need for cameras that are able to withstand extreme environmental conditions and for simple, low-cost, aerodynamic mounting apparatus that resists vibration and provides a low-cost heating mechanism to prevent environmental impairment of the camera view at extreme temperatures.  
         SUMMARY OF THE INVENTION  
         [0007]    In a preferred embodiment, the invention provides a simple, low-cost, aerodynamic camera system. A mounting apparatus that cushions a camera with a surrounding vibration-dampening layer of epoxy. The invention incorporates an efficient, low-cost heater that heats the camera window directly rather than heating the entire apparatus. The aircraft-mounted camera system of the invention is easy to manufacture, easy to install, is mechanically simple, and can be manufactured without the need for elaborate and expensive manufacturing equipment.  
           [0008]    A camera system according to the preferred embodiment of the invention includes a camera and a housing. The housing conforms to the topography of the aircraft and includes a receptacle with an opening. A window made of a material such as sapphire is included, with a heating element such as a conductive film disposed on the window. The camera is mounted within the receptacle and is attached to the window with an adhesive compound such as epoxy. The camera is held within the receptacle and insulated from vibration by a filler such as epoxy. An end plate holds the camera in place, and a backing plate attaches the entire assembly to the aircraft body.  
           [0009]    The camera system of the present invention has many advantages. For example, a pilot may observe the aircraft from the cockpit, such as gear down, blown tires, hot brakes, runway/taxiway alignment, flaps, slats, flight controls, thrust reversers, and so on. In addition, passengers may observe exterior view during flight. 
       
    
    
       [0010]    Other aspects, features, and advantages of the present invention will become apparent to those persons having ordinary skill in the art to which the present invention pertains from the following description taken in conjunction with the accompanying drawings.  
       BRIEF DESCRIPTION OF THE DRAWINGS  
       [0011]    [0011]FIG. 1 is a perspective view of an aircraft fitted with a surface-mounted camera of the invention;  
         [0012]    [0012]FIG. 1 a  is a fragmentary cross-sectional view of a section of an aircraft, particularly illustrating a topography thereof;  
         [0013]    [0013]FIG. 2 is an exploded view of an aircraft-mountable camera of the invention;  
         [0014]    [0014]FIG. 2 a  is a fragmentary perspective view of a camera of the present invention, particularly illustrating a lens arrangement of the camera;  
         [0015]    [0015]FIG. 3 is a perspective view of the camera of FIG. 2 as assembled;  
         [0016]    [0016]FIG. 4 is a cross-sectional view of a preferred embodiment of an aircraft camera of the invention, particularly illustrating an epoxy-embedded camera within a housing;  
         [0017]    [0017]FIG. 4 a  is a schematic view of a window heater configured in accordance with the invention; and  
         [0018]    [0018]FIG. 5 is a flowchart illustrating a method for manufacturing a camera in accordance with the invention. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0019]    Referring to the drawings in more detail, FIG. 1 is an exemplary illustration of a camera system  10  of the present invention mounted at the tail-section of an aircraft  20 . The aircraft may be any type of solid-body aircraft, including for example a jet, propeller plane or a helicopter. Although the camera system  10  may be mounted in nearly any location along the topography of the aircraft  20 , the camera system  10  is shown mounted to a leading edge  22  of a tail section  24  of the aircraft  20 . As shown in FIG. 1 a,  the surface of the tail section  24  at the leading edge  22  has a topography indicated by numeral  26 . For the purposes of this description, the camera system  10  will be described as configured to be mounted to the tail section  24 . However, those skilled in the art will appreciate that the camera system  10  may be configured to mount to other sections of the aircraft  20 , for example, a wing section  27 , a belly section  28 , or a nose section  29 .  
         [0020]    [0020]FIG. 2 is an exemplary illustration of an exploded view of a camera system  10 , detailing the component parts. The housing  30  includes a flange portion  40  and a receptacle  50 . The housing  30  is preferably made of a strong material capable of withstanding the environmental conditions associated with aircraft flight, such as aluminum, and may be made of any material commonly used for aircraft bodies. As shown in FIG. 4, an opening  60  is included, shown in a circular shape at the end of the receptacle  50 . Opening  60  and receptacle  50  may be any shape that corresponds to the shape of camera  80 . A window  70  is also shown that fits within receptacle  50  and seats within the opening  60 .  
         [0021]    As shown in FIG. 2, window  70  may be as a circular disk and may be made of any clear material know to those skilled in the art to be capable of withstanding the temperature extremes of flight, such as sapphire. Camera  80  may be any type of camera, including a still-photography camera, video camera or any other camera known by those skilled in the art. Camera  80  has a view end  90  that houses the camera lens and an output end  100  that provides connection points for the camera control systems, power supply and other electronics. Output end  100  is shown with a plug-type connection for camera electronics, with connector  105  being shown as a corresponding plug-type connection for camera electronics. However, output end  100  may employ any type of electronic connection interface known to those skilled in the art.  
         [0022]    An exemplary end plate  110  is shown attached to the end of the receptacle  50 , here shown attached with screws  120 . A backing plate  130  is further shown, which holds the housing  30  in place on the aircraft  20 . A heater connection for a window heater (shown in FIG. 4) is fed into the aircraft  20  through heater connector  140 . As shown in FIG. 2 a , the camera lens  92  is recessed from the camera view end  90 , thereby defining a recess space  94  between the view end of the camera  80  and the camera lens  92 ., which will be discussed in more detail below.  
         [0023]    [0023]FIG. 3 is an exemplary perspective illustration of an assembled mounting apparatus for exemplary camera system  10 . Housing  30  is shown attached to backing plate  130 , sandwiching an aircraft skin  132  in between housing  30  and backing plate  130  and firmly attaching the entire assembly to the aircraft. Heater connector  140  is shown extending into the interior of the aircraft  20 . As can be seen, housing  30  and backing plate  130  are configured to conform in shape to the topography  26  of aircraft skin  132  to provide secure attachment and fit.  
         [0024]    [0024]FIG. 4 shows a cross-sectional view of an exemplary housing  30 . Window  70  is shown with a heater, here depicted as a conductive film  150  disposed upon the interior surface of the window. Conductive film  150  may be comprised of any material that is both optically transparent and capable of transforming electrical energy into thermal energy. Heater wires  160  provide current to the conductive film  150 , which translates the current into heat. Solder  170  is shown connecting the heater wires  160  to the conductive film  150 . Other types of attachment may be similarly used that are known to those skilled in the art. As shown in FIG. 4 a , a heater  172  of the invention includes a control circuit  174  for providing current to the conductive film  150  through wires  160 . One example of a conductive film that may be utilized is indium titanium oxide (ITO).  
         [0025]    The camera  80  may be attached to the interior surface of the window  70  by a,first portion of adhesive compound  180  such as epoxy, sandwiching the conductive film  150  between a lens  182  of the camera  80  and the window  70  of the housing  30 . A second portion of adhesive compound  190 , such as epoxy, may be used to loosely attach the window  70  to the interior lip  185  of the opening  60  of the receptacle  50 , allowing adjustment of the camera position during assembly of the video system prior to fixing the camera firmly in place. A space  200  is defined between the camera  80  and the interior wall of the receptacle  50 . This space  200  is filled with a filler  210 , such as epoxy, in order to hold the camera  80  in place and insulate it from vibration. The filler  210  may be any material, know to those skilled in the art to be capable of holding the camera  80  in a fixed position.  
         [0026]    [0026]FIG. 5 is a flowchart showing an exemplary manufacturing method for the camera mounting system. The camera heating system may be fabricated by first disposing the conductive film  150  on the window  70  (step  300 ) and then soldering a pair of wires  160  to the conductive film  150  (step  310 ). The window  70  may then be attached to the camera  80 . This may be accomplished by first purging a recess space between the window  70  and the lens  182  of the camera  80 , which space is indicated by numeral  312  in FIG. 4, a gaseous material such as nitrogen (step  320 ). The window  70  is then attached to the lens  182  an adhesive compound such as epoxy (step  330 ). The window/lens assembly may then be focussed by aligning the window  70  and the lens  182  to be substantially parallel with each other (step  335 ).  
         [0027]    The camera  80  with the window  70  attached is then loosely attached to the interior lip  185  of the opening  60  in the receptacle  50  (step  340 ), and the camera  80  is then adjusted until the desired viewing position is attained (step  350 ). The adhesive  190  is then allowed to set in order to hold the camera  80  firmly in the receptacle  50  (step  360 ). The space  200  between the camera  80  and the receptacle  50  is purged with, e.g., nitrogen (step  370 ) and impregnated with a filler  210  such as epoxy (step  380 ). The end plate  110  is attached to the output end of the camera  80 , and a backing plate  130  is used to attach the assembly to the aircraft (step  390 ). Either one or both of the plates  110  and  130  may be attached to the camera  80  while the filler  210  is setting to retain the camera in the desired alignment. When the filler  210  is set, the plates  110  and  130  may be detached to connect electronics to the camera as needed, and then reattached.  
         [0028]    Those skilled in the art will understand that the embodiments of the present invention described above exemplify the present invention and do not limit the scope of the invention to these specifically illustrated and described embodiments. The scope of the invention is determined by the terms of the appended claims and their legal equivalents, rather than by the described examples. In addition, the exemplary embodiments provide a foundation from which numerous alternatives and modifications may be made, which alternatives and modifications are also within the scope of the present invention as defined in the appended claims.