Rotating pyramidal mirror

Abstract

An apparatus includes a detector, a light source configured to emit light, a reflecting apparatus having multiple reflective facets, and a mirror. The reflecting apparatus is configured to rotate around an axis and arranged to reflect the emitted light from the light source and reflect backscattered light. The mirror is arranged to reflect the backscattered light from the reflecting apparatus towards the detector.

We claim: 
     
         1 . A system comprising:
 a housing at least partially encompassing an internal cavity;   a laser configured to emit pulsed light and positioned within the internal cavity;   a sensor positioned within the internal cavity;   a rotatable pyramidal mirror having multiple reflective facets and arranged to reflect the emitted pulsed light and backscattered light; and   a mirror arranged to reflect the backscattered light from the rotatable pyramidal mirror towards the sensor, the mirror is positioned between the laser and the rotatable pyramidal mirror.   
     
     
         2 . The system of  claim 1 , further comprising:
 a lens positioned between the laser and the mirror.   
     
     
         3 . The system of  claim 2 , further comprising:
 a focusing lens positioned between the mirror and the sensor.   
     
     
         4 . The system of  claim 3 , wherein the mirror is a static mirror. 
     
     
         5 . The system of  claim 4 , wherein the static mirror includes an aperture through which the emitted pulsed light passes through. 
     
     
         6 . The system of  claim 1 , further comprising:
 a lens positioned between the laser and the rotatable pyramidal mirror.   
     
     
         7 . The system of  claim 1 , further comprising:
 a rotatable mirror positioned between the laser and the rotatable pyramidal mirror and arranged to direct the emitted pulsed light towards the rotatable pyramidal mirror.   
     
     
         8 . The system of  claim 7 , further comprising:
 a focusing lens optically positioned between the rotatable pyramidal mirror and the sensor.   
     
     
         9 . The system of  claim 7 , further comprising:
 a first lens optically positioned between the rotatable mirror and the rotatable pyramidal mirror.   
     
     
         10 . The system of  claim 9 , further comprising:
 a second lens optically positioned between the rotatable mirror and the rotatable pyramidal mirror.   
     
     
         11 . The system of  claim 1 , wherein the sensor is positioned between the mirror and the rotatable mirror. 
     
     
         12 . The system of  claim 1 , wherein the mirror is a parabolic mirror, the system further comprising:
 a rotatable mirror positioned between the laser and the rotatable pyramidal mirror and arranged to direct the emitted pulsed light towards the rotatable pyramidal mirror.   
     
     
         13 . The system of  claim 12 , wherein the parabolic mirror includes an aperture, wherein the rotatable mirror is arranged to direct the emitted pulsed light through the aperture. 
     
     
         14 . The system of  claim 1 , wherein the rotatable pyramidal mirror includes only six reflective facets. 
     
     
         15 . An apparatus comprising:
 a light sensor;   a laser configured to emit light;   a rotatable pyramidal mirror having multiple reflective facets and arranged to reflect the emitted pulsed light and backscattered light;   a first lens optically positioned between the laser and the rotatable pyramidal mirror;   a second lens optically positioned between the first lens and the rotatable pyramidal mirror; and   a mirror arranged to reflect the backscattered light from the rotatable pyramidal mirror towards the light sensor.   
     
     
         16 . The apparatus of  claim 15 , further comprising:
 a rotating mirror arranged to reflect the emitted light from the laser to the first lens.   
     
     
         17 . The apparatus of  claim 15 , wherein the mirror includes an aperture through which the emitted light passes from the laser to the rotatable pyramidal mirror. 
     
     
         18 . The apparatus of  claim 15 , further comprising:
 a focusing lens positioned between the mirror and the light sensor and configured to focus the backscattered light towards the light sensor.   
     
     
         19 . The apparatus of  claim 15 , wherein the first lens and the second lens are cylindrical lenses. 
     
     
         20 . The apparatus of  claim 19 , wherein the first lens is smaller than the second lens.