초록 ▼

Undesirable reflections from an element in an optical system are eliminated by passing incoming light through a polarizer and a 45°optical rotator before it strikes the reflective element. The reflected light component is again rotated 45°by the rotator, for a total rotation of 90°, whereupon it is

Undesirable reflections from an element in an optical system are eliminated by passing incoming light through a polarizer and a 45°optical rotator before it strikes the reflective element. The reflected light component is again rotated 45°by the rotator, for a total rotation of 90°, whereupon it is blocked from leaving the system by the polarizer. Alternatively, a quarter wave plate or other circular polarizing component may replace the rotator to result in a net rotation of the polarization of the reflected light by 90°.

대표청구항 ▼

In a military optical viewing system, an apparatus which eliminates the detection of retroreflected light energy by a nonuser, the apparatus comprising: a weapon sight including a hollow housing and an eyepiece in which a plurality of lens members are mounted in spaced relation along an optical path

In a military optical viewing system, an apparatus which eliminates the detection of retroreflected light energy by a nonuser, the apparatus comprising: a weapon sight including a hollow housing and an eyepiece in which a plurality of lens members are mounted in spaced relation along an optical path, the elements aligned such that the light energy enters the forward end of the housing and is impinged on the eyepiece at the rearward end of the housing; a polarizing means, located forward of the eyepiece, along the optical path, operative over a known range of wavelengths for polarizing light entering the system before the light reaches the eyepiece; and a shifting means, located between the polarizing means and the eyepiece and along the optical path, operative over a predetermined range of wavelengths for changing the polarization state of light passed by the polarizing means before the polarized light reaches the eyepiece and such that two passes through said shifting means results in a 90°rotation of the plane of polarization of the light; whereby light energy which is retroflected off the eyepiece is prevented vented from leaving the optical viewing system and being detected by the nonuser.