Patent ID: 7637615

Claim:
A device for tracking a position of a pupil of an eyeball, by directing light toward the eyeball and using a portion of the light which is reflected from the eyeball, the device comprising: a light emitter emitting a light beam; a scanner scanning two-dimensionally the light beam emitted from the light emitter, over the eyeball, in a primary scan direction and a secondary scan direction which are oriented crosswise relative to each other, to thereby create a plurality of successive scan lines; a detector detecting a time-varying intensity of a reflected instantaneous light beam which is a portion of the light beam entering a surface of the eyeball which is reflected therefrom, and producing an intensity signal indicative of the intensity of the reflected instantaneous light beam; and a processor which tracks a pupil position based on intensity changes of the reflected instantaneous light beam represented by the intensity signal outputted from the detector.