Patent ID: 6061916
Filing Date: 2000-05-16
Classification: G01S,G02B

Abstract:
A head tracking system for use in combination with night vision goggles, and comprising:a tracking processor (12),a radiation sensor (16),a radiation emitter (18), the radiation emitter producing at its output (46) infra-red radiation with a spectral peak at a wavelength greater than approximately 1000 nm, and the radiation emitter (18) comprising:an LED (40) emitting with a spectral peak at a first wavelength which is less than approximately 1000 nm,a photoluminescent material (42) disposed between the LED (40) and the output (46) of the radiation emitter (18), the photoluminescent material absorbing radiation at approximately the first wavelength and emitting radiation at a second wavelength which is greater than approximately 1000 nm and which is detectable by the radiation sensor (16),whereby only radiation greater than approximately 1000 nm is output from the radiation emitter (18).