Patent ID: 7952690

Claim:
A method of acquiring a 3-D image of a scene, comprising: illuminating said scene with modulated light emitted at an illumination unit; imaging said scene onto an array of lock-in pixel sensor cells and detecting at said lock-in pixel sensor cells light scattered in said scene; determining a modulation phase of the light detected at said lock-in pixel sensor cells; providing a reference modulation phase; calculating depth information on said scene based upon said reference modulation phase and said modulation phase of the light detected at said lock-in pixel sensor cells; wherein said modulated light is emitted by a plurality of individual light emitting devices of said illumination unit, each of said light emitting devices emitting a part of said modulated light, and wherein said reference modulation phase is provided as an average of the modulation phases of the parts of modulated light emitted by said light emitting devices.