Abstract:
A boresight collimating device using a novel way of achieving multiple source illumination of the pin hole/reticule using one moving part, a rotating elliptical mirror, while maintaining precision alignment of the device is disclosed.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     The present application claims the benefit of previously filed Provisional Patent Application Ser. No. 61/215,350. 
    
    
     FIELD OF THE INVENTION 
     This invention belongs to the field of manufacture of boresight collimating devices. More specifically it is a novel way of achieving multiple source illumination of a pin hole/reticule using one moving part, an elliptical mirror, while maintaining precision alignment of the device. 
     BACKGROUND OF THE INVENTION 
     The challenges of designing an optical system that operates effectively over such a wide waveband are great, typically incurring high levels of complexity and exotic materials. This design concept utilizes powered mirrored surfaces to overcome the need for either a complex system or extensive use of exotic materials such as those disclosed in U.S. Pat. Nos. 6,950,243, 6,765,663, or 6,020,994. 
     Typically the imaging side of the system is the most sensitive for maintaining alignment and therefore cannot employ moving mechanical components. The illumination side of the system is not as sensitive to alignment and can employ moving component(s) to achieve the design goals. This disclosure surpasses existing designs that, while being capable of achieving these goals, have removable parts that are commonly misplaced/lost. Improvement of the design as described in this disclosure will reduce the overall cost of operating a wide waveband boresight instrument in the field. 
     BRIEF SUMMARY OF THE INVENTION 
     This invention is a novel way of achieving multiple source illumination of a pin hole/reticule using one moving part, a rotating elliptical mirror, while maintaining precision alignment of the device. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       For a fuller understanding of the nature and objects of the invention, reference should be made to the following detailed description, taken in connection with the accompanying drawings, in which: 
         FIG. 1  shows the boresight collimating device of the preferred embodiment. 
         FIG. 2  shows four positions of the rotating elliptical mirror of the boresight collimating device using four illumination sources of the preferred embodiment. 
     
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
     The preferred embodiment of the invention discloses a boresight apparatus for field sighting-in of small arms utilizing sights/scopes that operate at ˜550 nm, 890 nm, near infrared (NIR) and far infrared (FIR) wavelengths without interchangeable/removable parts. 
     In boresight collimating devices mirrored surfaces are inherently achromatic and can be used in place of exotic materials where a wide waveband is needed. These mirrors need to have optically powered surfaces that are either spherical, parabolic, elliptical, aspheric, etc. Typically the system needs several focused light sources to produce the necessary illumination, yet there is not room for multiple reflective surfaces to achieve illumination of the pinhole in the system. 
     In the preferred embodiment as shown in  FIGS. 1 and 2  the illumination system employs a rotating elliptical mirror ( 4 ) that rotates about one of its foci. The illumination sources ( 5 ) creating multiple source beams ( 2 ) are placed at multiple locations, defined by the other foci of the rotating elliptical mirror ( 4 ), so that when the rotating elliptical mirror ( 4 ) is rotated each different source ( 5 ) is correctly positioned to reflect the source beam ( 2 ) at the foci ( 7 ) of the rotating elliptical mirror ( 4 ). The rotation of the rotating elliptical mirror ( 4 ) can also act as the electrical switch, turning on the appropriate source ( 5 ). When the source ( 5 ) is switched on, and correctly positioned with respect to the rotating elliptical mirror ( 4 ), it illuminates a pinhole ( 6 ) of the appropriate size for the system. 
     This pinhole/reticule ( 6 ) is then imaged using a parabolic mirror ( 3 ) having the same foci ( 7 ) as the rotating elliptical mirror ( 4 ), collimating the light output ( 1 ) so that the user sees an alignment dot/pattern in the sight/scope. The dot/pattern allows the user to align the sighting device using the reticule pattern within the boresight collimating device without firing the weapon. 
     Since certain changes may be made in the above described boresight collimating device without departing from the scope of the invention herein involved, it is intended that all matter contained in the description thereof or shown in the accompanying figures shall be interpreted as illustrative and not in a limiting sense.