A near infrared illuminator for enhancing viewing of a target viewed with infrared viewing device when the target falls within a predetermined range. A pulse generator generates a laser pulse in the near infrared with a pulse clock for control of laser brightness and a pulse frequency adjust for control...http://www.google.com.au/patents/US5336899?utm_source=gb-gplus-sharePatent US5336899 - Adjustable near infrared rangefinder illuminator
