| 摘要 |
A three-dimensional time-of-flight (TOF) system includes a low power optical emitter whose idealized output S1=cos(omega.t) is reflected by a target distance z away, and is detected by a two-dimensional array of pixel detectors and associated narrow bandwidth detector electronics and associated processing circuitry preferably fabricated on a common CMOS IC. The idealized detected reflected energy S2=A.cos(omega.t+&PHgr;), where phase shift &PHgr; is proportional to TOF or z, and z=&PHgr;.C/2.omega=&PHgr;.C/{2.(2.pi.f)} and is known modulo 2piC/(2.omega)=C/(2.f). Phase &PHgr;, distance z, and other information, is determined by homodyne-mixing S2 with the drive signal to the optical emitter. The idealized mixer output per each pixel detector is 0.5.A.{cos(omega.t+&PHgr;)+cos(&PHgr;)} and has average value 0.5.A.cos(&PHgr;). The overall system is small, robust and requires relatively few off-chip discrete components. On-chip circuitry can use TOF data to simultaneously measure distance, object point velocity, object contours, including user interface with virtual input devices.
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