How 3D imaging works (to be edited)

Laser Triangulation

One of the most popular method used by the industry is Laser triangulation because of its simplicity.
Laser triangulation is accomplished by projecting a laser line or point onto an object and then capturing its reflection with a sensor located at a known distance from the laser's source. The resulting reflection angle can be interpreted to yield 3D measurements of the part.
By these differences of position caused by parallax, the height position of the target is reflected on in respective to the Y position of the image viewed.

Confocal technology

Confocal microscopy has been widely used for measurement of tiny objects. However, using such method for measurement of comparatively larger objects is not used often. Utilizing the latest technology development, the system can measure 3D objects of small to medium size (such as 1-10mm variation in height), with a speed that has never been so fast.
In comparing with the conventional triangulation method for 3D measurement, the confocal method yields the following advantages:

1) The surface condition of the measured object is not important; no matter whether they are matte surface or even shiny surface, it can accommodate certain degree of tilt.

2) It is able to measure holes in depth, whereas with triangulation measurement, either the camera or the light is blocked by the deep edges and can only be overcome by taking another image with the object reversed.

The first drawback of this confocal method is speed. However, with the implementation of the mentioned laser line curtain illumination and the using of ultra high speed line scan camera for light feedback detection, the overall system scanning speed becomes comparable to the popular triangulation method, yet yields the outstanding advantages as mentioned in (1)&(2) above that triangulation method can never achieve.