INFRARED SYSTEM Russian patent published in 2015 - IPC G02B13/14 G02B15/14 G02B23/04 

FIELD: physics.

SUBSTANCE: infrared system consists of a first channel, comprising an afocal attachment and a focusing lens arranged in series, a second comprising an input lens and a projection lens and a photodetector which are common for the first and second channels and are arranged in series. The system also comprises devices for switching radiation flux from the first and second channel to the photodetector. In the first channel, the focusing lens has a discretely variable focal distance. In the second channel the input lens has a smoothly variable focal distance. The radiation flux switching device is installed in front of the projection lens.

EFFECT: longer detection range and high spatial resolution of the system owing to smoother variation of the focal distance by expanding the variation range of focal distance towards the maximum value.

5 cl, 1 dwg, 4 tbl