Clip-on night vision device

Abstract

A night viewer ( 10 ) is adaptable to generate an enhanced image suitable for viewing through an optical scope ( 16 ). An input end ( 18 ) of the viewer ( 10 ) receives the image to be enhanced through an objective lens ( 20 ). An image enhancing unit ( 22 ) enhances the image. The enhanced image is optically transmitted from a display ( 28 ) to the ocular lens ( 24 ) of the scope ( 16 ). The display ( 28 ) is operably connected with the image enhancing unit ( 22 ) to display the enhanced image. A Risley prism ( 30 ) located in an image path ( 32 ) is used to controllably adjust and to maintain boresight alignment ( 36 ).

1 . A focusable night viewer device adaptable to receive an image to be enhanced of a scene to be viewed, the invention comprising:
 an objective lens assembly for gathering light forming the image of the scene to be viewed;   an image enhancing unit for enhancing the image into a desired format; the image to be enhanced received at an input end of the image enhancing unit;   an output image display unit operably connected with the image enhancing unit for viewing of the enhanced image by a user;   focusing means controllable by a user for moving a focus cell assembly mounted between the objective lens assembly and the image enhancing unit fore and aft along a desired optical axis through the objective lens assembly; and,   rotational movement of a user accessible knob assembly about an axis essentially perpendicular to the optical axis is mechanically translated into rotational movement of the focus cell to move the focus cell fore and aft relative to the objective lens assembly along the desired optical path through the objective lens assembly.   
     
     
         2 . The invention of  claim 1  wherein a central axis of the objective lens and a central axis of the image enhancing unit are aligned. 
     
     
         3 . The invention of  claim 1  wherein the focus cell moves along supported by a track system responsive to a user's control of a rotatable knob. 
     
     
         4 . The invention of  claim 1  wherein the focus cell moves guided by a helical guide means for rotational and translational movement of the focus cell relative to the objective lens assembly along the desired optical axis through the objective lens assembly. 
     
     
         5 . The invention of  claim 4  wherein the helical guide includes complementary threaded segments formed on a portion of the exterior of the focus cell and in the interior of the night viewer device. 
     
     
         6 . The invention of  claim 1  wherein the knob is tadpole shaped for enhanced user control. 
     
     
         7 . The invention of  claim 6  wherein the rotational movement of the knob is mechanically transmitted to a rack for moving a spur gear attached to the focus cell. 
     
     
         8 . A method for focusing a night viewer device of the type having an objective lens assembly for gathering light forming the image of the scene to be viewed, an image enhancing unit for enhancing the image into a desired format, and, the image to be enhanced received at an input end of the image enhancing unit, including the steps of:
 controllably moving a focus cell assembly of the image enhancing unit along a desired optical axis through the objective lens assembly through rotational movement of a user accessible knob assembly about an axis essentially perpendicular to the optical axis is mechanically translated into rotational movement of the focus cell to move the focus cell fore and aft relative to the objective lens assembly along the desired optical path through the objective lens assembly.   
     
     
         9 . The method of  claim 8  wherein the focus cell moves guided by a helical guide means for rotational and translation al movement of the focus cell relative to the objective lens assembly along the desired optical axis through the objective lens assembly. 
     
     
         10 . The method of  claim 9  wherein the helical guide includes complementary threaded segments formed on a portion of the exterior of the focus cell and in the interior of the night viewer device. 
     
     
         11 . The method of  claim 8  wherein the knob is tadpole shaped for enhanced user control. 
     
     
         12 . The method of  claim 8  wherein the rotational movement of the knob is mechanically transmitted to a rack for moving a spur gear attached to the focus cell.