Page "3D scanner" Paragraph 22

The triangulation 3D laser scanners are also active scanner that use laser light to probe the environment.

With respect to time-of-flight 3D laser scanner the triangulation laser shines a laser on the subject and exploits a camera to look for the location of the laser dot.

Depending on how far away the laser strikes a surface, the laser dot appears at different places in the camera's field of view.

This technique is called triangulation because the laser dot, the camera and the laser emitter form a triangle.

The length of one side of the triangle, the distance between the camera and the laser emitter is known.

The angle of the laser emitter corner is also known.

The angle of the camera corner can be determined by looking at the location of the laser dot in the camera's field of view.

These three pieces of information fully determine the shape and size of the triangle and gives the location of the laser dot corner of the triangle.

In most cases a laser stripe, instead of a single laser dot, is swept across the object to speed up the acquisition process.

The National Research Council of Canada was among the first institutes to develop the triangulation based laser scanning technology in 1978.