CPC G02B 23/12 (2013.01) [G02B 13/16 (2013.01); G02B 25/001 (2013.01)] | 11 Claims |
1. A night vision device comprising:
a housing having a first end and a second send;
an objective lens mounted on the housing nearer to a first end than a second end, and arranged for receiving light from ambient into the housing;
an image intensifier mounted on the housing and located toward the second end of the housing from the objective lens;
an eyepiece lens mounted on the housing and located toward the second end of the housing from the image intensifier;
an adjustable iris defining an iris opening, the adjustable iris being mounted on the housing and located toward the second end of the housing from the objective lens;
a sensor for detecting light intensity connected to the housing and located toward the second end of the housing, the sensor being configured to control a size of an area of the iris opening in response to the light intensity detected for keeping the area of the iris small so as to maintain a depth of field of the night vision device.
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