Rangefinding system using hybrid pattern projections

The practical three-dimensional measurement system with a high resolution based on a space code light pattern projection and a phase-shifted light pattern projection is presented. Three-dimensional measurement device's so-called, rangefinder, are expected to be applied in the apparel, medical and various fields. The performance of a rangefinder is evaluated by the measurements of time, depth, size, etc. The system using a space code technique can stably acquire the depth of an object although the resolution of the depth is not good because an object's space is coded in the shape of a wedge. On the other hand, in a phase shift technique, the high resolution depth of an object is able to be theoretically acquired because the object's space is divided finely by phase shifted light projection. But it is difficult to stably acquire the depth of an object because of the phase connection problem. In this paper, these problems (which are high resolution and phase connection problem) are able to be solved by both the space code technique and the phase shift technique. The effectiveness of this system is also described.