Abstract: A system used with a virtual device inputs or transfers information to a companion device, and includes two optical systems OS1, OS2. In a structured-light embodiment, OS1 emits a fan beam plane of optical energy parallel to and above the virtual device. When a user-object penetrates the beam plane of interest, OS2 registers the event. Triangulation methods can locate the virtual contact, and transfer user-intended information to the companion system. In a non-structured active light embodiment, OS1 is preferably a digital camera whose field of view defines the plane of interest, which is illuminated by an active source of optical energy. Preferably the active source, OS1, and OS2 operate synchronously to reduce effects of ambient light. A non-structured passive light embodiment is similar except the source of optical energy is ambient light. A subtraction technique preferably enhances the signal/noise ratio. The companion device may in fact house the present invention.

Abstract: A three-dimensional time-of-flight (TOF) system includes a low power optical emitter whose idealized output S1=cos(&ohgr;·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(&ohgr;·t+&PHgr;), where phase shift &PHgr; is proportional to TOF or z, and z=&PHgr;·C/2·&ohgr;=&PHgr;·C/{2·(2·&pgr;·f)} and is known modulo 2&pgr;C/(2·&ohgr;)=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(&ohgr;·t+&PHgr;)+cos(&PHgr;)} and has average value 0.

Abstract: A three-dimensional imaging system includes a two-dimensional array of pixel light sensing detectors and dedicated electronics and associated processing circuitry fabricated on a common IC using CMOS fabrication techniques. In one embodiment, each detector has an associated high speed counter that accumulates clock pulses in number directly proportional to time of flight (TOF) for a system-emitted pulse to reflect from an object point and be detected by a pixel detector focused upon that point. The TOF data provides a direct digital measure of distance from the particular pixel to a point on the object reflecting the emitted light pulse. In a second embodiment, the counters and high speed clock circuits are eliminated, and instead each pixel detector is provided with a charge accumulator and an electronic shutter.