| US 7,471,376 B2 | ||
| Method and system for fast calibration of three-dimensional (3D) sensors | ||
| Cyrus Bamji, Fremont, Calif. (US); and Hakan Yalcin, Fremont, Calif. (US) | ||
| Assigned to Canesta, Inc., Sunnyvale, Calif. (US) | ||
| Filed on Jul. 06, 2007, as Appl. No. 11/825,582. | ||
| Claims priority of provisional application 60/818819, filed on Jul. 06, 2006. | ||
| Prior Publication US 2008/0007709 A1, Jan. 10, 2008 | ||
| Int. Cl. G01C 5/00 (2006.01) | ||
| U.S. Cl. 356—5.01 | 20 Claims |
| 1. A method of calibrating a time-of-flight (TOF) system of the type that emits light of a known phase, detects a portion
of said light reflected from a target object a distance Z away, and determines Z by examining phase shift in detected reflected
light relative to said known phase of emitted light, the method comprising the following steps:
(a) disposing a target object a distance Zx from said TOF system, said distance Zx being within operating distance range of said TOF system;
(b) altering said known phase of said emitted light by at least two known phase values;
(c) for each known phase value of said emitted light, determining from detected reflected light a corresponding phase shift
relative to said known phase;
(d) using corresponding relative phase shift determined at step (c) to form an electrical model of detection characteristics
of said TOF system; and
(e) storing data representing said electrical model;
wherein data stored at step (e) is acquirable using only optical energy emitted by said TOF system and traversing said distance
Zx and is useable during run-time operation of said TOF system to provide calibrated values of Z responsive to phase shift in
detected reflected light.
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