Laser Scanning

Reproducing an object by physically drawing it into a computer is difficult. Often the result does not match the original. Fast, affordable optical range laser scanning is a precision process that can be used to create a 3D image of an object where none has existed before.

Once an object is scanned the 3D image can be sent to prototyping or entered into a CAD program, saving hours of painstaking work and significant expense. Laser scanning is accomplished by using a laser device that collects range data.


ModelMakerTM Laser Head 		A common method for acquiring range data is active optical triangulation. Measuring an object's surface depth on a regular sampling lattice produces range data. Then by connecting triangular elements with the nearest neighbors, a range image is created. Generally, a 1D or 2D sensor is swept linearly across the object or circularly around it. This is usually not enough information to reconstruct the entire object being scanned. Therefore, multiple passes must be made from different orientations. Algorithms are required to merge multiple range images into a single description of the surface. Although this technique has been in use for more than 20 years, its speed and accuracy have increased dramatically in recent years with the development of stable imaging sensors such as CCDs and lateral effect photodiodes.

There are several different types of scanners that accomplish this, their primary differences being in the structure of the illuminant (typically point, stripe, multi-point, or multi-stripe), dimensionality of the sensor (linear array or CCD grid), and the scanning method (move the object or move the scanner hardware). One of the most obvious benefits of laser scanning is the tremendous increase in speed in which a prototype can be reproduced.

Traditional methods call for the object to be measured and redrawn in a CAD program. Not only is this extremely time-consuming, but organic shapes are almost impossible to create using this method. Objects such as an ergonomically designed handle or new toy designs can be easily sculpted and then scanned to ensure the intended result. Laser scanning is at its best when dealing with ergonomic shapes. The entire scanning and post-editing process can happen in hours. This time savings means faster response to requirements. Because laser scanning technology is relatively quick, it is generally much cheaper than other types of scanning.