What is the working principle of a 3D scanner

A 3D scanner is a scientific instrument used to detect and analyze the shape (geometric structure) and appearance data (such as color, surface reflectivity, etc.) of objects or environments in the real world. The data collected is often used for 3D reconstruction calculations, creating digital models of actual objects in the virtual world. The working principle of a 3D scanner is mainly based on several different technologies, and the following are some common working principles:

1. Principle of structured light scanning:

Adopting a combination of structured light technology, phase measurement technology, 3D vision technology, and composite 3D non-contact measurement technology. By projecting specific light patterns (such as stripes, dots, or grids) onto the surface of an object, and then using a camera to capture the deformation of these light patterns on the surface of the object. By analyzing the deformed light mode, the three-dimensional information of the object surface is calculated.

2. Laser scanning principle:

The laser scanner emits a laser beam onto the surface of an object and then receives the reflected laser. By measuring the time difference or angle change between laser emission and reception, the distance from surface points of an object to the scanner can be determined. Scanners typically include one or more rotatable laser emitters and receivers to cover the entire surface of an object.

3. Three coordinate principle:

A coordinate measuring machine (CMM) establishes a Cartesian coordinate system with three mutually perpendicular axes of motion X, Y, and Z. The probe (usually a probe with a small ball) moves in the coordinate system and comes into contact with the surface of the object. The detection system records the precise position of the center point of the measuring ball in the coordinate system. By moving the measuring head and measuring multiple points, the geometric dimensions, shape, and positional tolerances of the object can be calculated.

4. Principle of binocular vision (stereo vision):

Similar to the working principle of the human eye, two cameras are used to simultaneously capture objects from slightly different angles. By analyzing the difference (i.e. disparity) between the images captured by two cameras, the three-dimensional coordinates of surface points of an object can be calculated.

5. Principle of phase difference measurement:

By projecting sine wave shaped light onto the surface of an object and detecting the phase change of the reflected light, the three-dimensional shape of the object surface is determined. This method is typically used for fast and high-precision measurements.

6. Time of Flight (TOF) principle:

Laser pulses or light waves are emitted onto the surface of an object and their return time is measured. By measuring the flight time of light, the distance from an object to the scanner can be determined.

These technologies utilize the physical properties of light such as reflection and refraction, combined with computer vision and image processing techniques, to achieve the acquisition of three-dimensional information on the surface of objects. Different 3D scanners may use one or more combinations of the above principles to achieve accurate 3D measurements. The choice of principle depends on specific application requirements, measurement accuracy, speed, object characteristics (such as material, color, shape, etc.), and cost factors. If you want to learn more about the technology and applications of 3D scanners, you can consult Weishen Technology, and we will provide you with application cases and technical parameters in various fields.