Combined day and night weapon sight

Abstract

A combination day/night sight includes an image intensifying sensor/display combination and a daytime optical path length compensator that may be selectively placed within the optical path. Use of the optical path length compensator when the image intensifying sensor/display is not being used eliminates the need for moving optical elements. The night sight therefore requires no change in focus or bore sight adjustment after switching between day and night operations.

1 . A night vision device, comprising: 
 an optical path defined within the night vision device;    an image intensifying sensor/display combination;    a daytime optical path length compensator having substantially the same optical path length as the image intensifying sensor/display combination; and    means for selectively placing either the image intensifying sensor/display combination or the daytime optical path length compensator within the optical path.    
   
   
       2 . The night vision device according to  claim 1 , further comprising a mode selection mechanism housing the image intensifying sensor/display combination and the daytime optical path length compensator, the mode selection mechanism being structured to selectively place either the image intensifying sensor/display combination or the daytime optical path length compensator.  
   
   
       3 . The night vision device according to  claim 2 , further comprising a slider containing both the image intensifying sensor/display combination and the daytime optical path length compensator, the slider being structured to selectively reciprocate between a day position and a night position, the daytime optical path length compensator being positioned within the optical path in the day position, the image intensifying sensor/display combination being positioned within the optical path in the night position.  
   
   
       4 . The night vision device according to  claim 3 , wherein the reciprocation of the slider is in a form selected from the group consisting of sliding laterally between the daytime position and the night position and rotating between the daytime position and the night position.  
   
   
       5 . The night vision device according to  claim 4 , wherein rotation of the slider is within a plane selected from the group consisting of substantially parallel to the optical path and substantially perpendicular to the optical path.  
   
   
       6 . The night vision device according to  claim 1 , wherein the means for selectively positioning either the image intensifying sensor/display combination or the daytime optical path length compensator within the optical path include at least one mirror structured to be selectively movable to direct light towards either the image intensifying sensor/display combination or the daytime optical path length compensator.  
   
   
       7 . The night vision device according to  claim 1 , further comprising a beam splitter structured to direct a portion of incoming light to an electro-optical module.  
   
   
       8 . The night vision device according to  claim 7 , wherein the electro-optical module includes a camera structured to permit a person to view an image as viewed by a shooter.  
   
   
       9 . The night vision device according to  claim 1 , further comprising a coaxial objective lens.  
   
   
       10 . The night vision device according to  claim 9 , wherein the coaxial objective lens has a central portion and an annular portion, one of the central portion and annular portion being structured to transmit visible light, and the other of the central portion and the annular portion being structured to transmit light having a wavelength separate from visible light.  
   
   
       11 . The night vision device according to  claim 10 , wherein the light having a wavelength separate from visible light has a wavelength selected from the group consisting of infrared and near infrared.  
   
   
       12 . The night vision device according to  claim 1 , further comprising a zoom eyepiece structured to magnify an image presented to a user through the night vision device.  
   
   
       13 . The night vision device according to  claim 1 , further comprising an aiming reticle.  
   
   
       14 . The night vision device according to  claim 13 , wherein the aiming reticle is selected from the group consisting of etched glass, wire, deposited metal, and holographic projected design.  
   
   
       15 . The night vision device according to  claim 13 , further comprising means for moving the reticle with respect to an image displayed by the night vision device.  
   
   
       16 . The night vision device according to  claim 1  further comprising an image erector assembly disposed after the image intensifying sensor/display combination or the daytime optical path length compensator.  
   
   
       17 . The night vision device according to  claim 1 , further comprising an elastomer disposed between the image intensifying sensor/display combination and the slider.  
   
   
       18 . The night vision device according to  claim 1 , wherein the night vision device is a day/night sight for a firearm.