Structured Light 3D Scanners 375

“Structured Light 3D Scanners” provides an overview of the components, functions, and applications of structured light scanners. A structured light scanner is a type of 3D optical measuring device used to record an object's geometry. Structured light scanners gather measurements by projecting an LED light pattern onto an object and capturing its shape with multiple cameras. The captured images are then reconstructed to create a 3D model.

Structured light scanners are used for many applications in manufacturing, including inspection, GD&T analysis, and reverse engineering processes. After taking this class, users will be able to describe structured light scanners and how they function.

Class Details

Class Name:
Structured Light 3D Scanners 375
Number of Lessons:

Class Outline

  • Portable Metrology
  • 3D Optical Scanning
  • Structured Light Scanners
  • Structured Light Scanner Applications
  • Review: Structured Light Scanners Introduction
  • Structured Light Scanner Components
  • Types of Light
  • Projected Patterns
  • Review: Structured Light Scanner Components
  • Structured Light Scanner Measurement
  • Structured Light Scanner Operation
  • Data Collection and Analysis
  • Final Review


  • Describe portable metrology devices.
  • Distinguish between laser and structured light scanners.
  • Describe structured light scanners.
  • Describe structured light scanner applications.
  • Identify structured light scanner components.
  • Describe the types of light used in structured light scanning.
  • Describe projected structured light patterns.
  • Describe how structured light scanners function.
  • Describe structured light scanner operation.
  • Describe structured light scanner data collection and analysis.

Job Roles



Vocabulary Term Definition
3D Three-dimensional. Having or appearing to have length, breadth, and depth. 3D models show an object's shape better than two-dimensional (2D) drawings.
3D optical scanning Capturing the geometric surface data of an object using a combination of light and sensors. 3D optical scanning collects data to be turned into digital 3D models.
3D scanner A portable measuring device that uses light and sensors to measure an object's geometric shape. 3D scanners collect large amounts of surface data quickly.
ambient Coming from the surrounding area. Ambient lighting is light that normally occurs in the environment or space, like room lighting or natural lighting.
automated Controlled by machines or computers with little human interaction. Automated robots can use structured light scanners to measure parts.
blue light A visible, short-wavelength light. Blue light is less likely to be affected by other light sources.
CAD Computer-aided design. A computer software program that aids in the automated design and technical precision drawing of a part, product, process, or building. CAD models can be used in part inspection.
cameras A device used to capture still images, such as photographs, or moving images, such as videos. Cameras capture surface data when 3D scanning a part.
climate-controlled Having artificially regulated air temperature, humidity, and movement. Climate-controlled environments are not necessary for portable metrology devices.
CMM arms A portable measuring device consisting of segments connected by joints. CMM arms operate using either contact or noncontact methods.
color map A data visualization tool that displays the differences between a scanned object and nominal CAD model using colors to represent deviations. Color maps allow designers to make adjustments to the actual part design.
computer-aided design CAD. A computer software program that aids in the automated design and technical precision drawing of a part, product, process, or building. Computer-aided design models can be used in part inspection.
contact probes A type of probe consisting of a synthetic ruby-tipped stylus that makes physical contact with a workpiece. A contact probe records one single point each time it touches a part's surface.
coordinate measuring machines CMM. A sophisticated measuring instrument that uses a suspended probe to measure parts in three-dimensional space. Coordinate measuring machines operate using either contact or noncontact methods.
deviations The difference between a standard and a result. Deviations can lead to parts that do not meet specifications.
digital light processing DLP. Technology that uses micro-mirrors to project images from a monitor onto a large screen. Digital light processing projectors allow patterns to be quickly projected onto objects.
first-off Occurring before all others in a series. First-off parts are the first finished parts created by a new manufacturing setup.
fixed CMM A stationary coordinate measuring machine. A fixed CMM has a large base with a suspended probe and is operated in a controlled environment.
fluorescent Emitting absorbed light by a substance. Fluorescent lighting is less intense than LED lighting.
fringe projection The process of projecting a series of two-dimensional patterns of lines onto a surface. Fringe projection shows an arrangement of lines that vary in size and quantity.
geometric dimensioning and tolerancing GD&T. An international standard for communicating instructions about the design and manufacturing of parts. Geometric dimensioning and tolerancing emphasizes the function of the part.
geometry The measurement, properties, and relationships of the lines and points of an object that make up its shape. Geometry is used when measuring and designing parts.
image sensors A device that detects and conveys information used to make an image. Image sensors capture surface data when 3D scanning a part.
incandescent Emitting light as a result of being heated. Incandescent lights use wire filaments to produce warm, glowing lights.
infrared Invisible light energy emitted by heated objects. Infrared light can be used to capture a visual representation of an object's surface geometry.
in-process Currently being produced by manufacturing. In-process parts are found throughout the process of turning raw material into finished products.
inspection The examination of a part during or after its creation to confirm that it adheres to specifications. During inspection, defects may be identified and corrected.
laser A device that generates an intense beam of light that can be precisely aimed and controlled. Laser beams are used to measure and capture surface data.
laser scanners A portable measuring device that uses a beam of light to measure an object's geometric shape. Laser scanners collect large amounts of surface data quickly.
laser trackers A portable measuring device that projects a beam of light at a retroreflective target to measure large objects. Laser trackers require a person to hold a target on the object being measured.
LED Light emitting diode. A semiconductor device that emits a narrow spectrum of light in a forward direction. Structured light scanners use LEDs to produce light patterns.
legacy Relating to a previous technology. Legacy models are typically archived or obsolete.
lenses The light-gathering component of a camera. Lenses determine the camera's field of vision.
measurement field The entire area that can be observed from a fixed position. A structured light scanner's measurement field is viewed by cameras to either side of the projector.
metrology The science of measurement. Metrology strives for accuracy, precision, and repeatability.
noise Unwanted surface data caused by light interference. Noise affects the accuracy of data collection.
nominal A stated measurement that may not correlate exactly with a physical part. Nominal measurements for a part indicate the size specified in the print or CAD model, which may differ from the size of the actual part.
noncontact probes A type of probe that consists of a laser or scanning system that does not physically contact the part surface. Noncontact probes are used to streamline surface inspection.
on-machine Relating to or being on a machine. On-machine parts can easily be measured with portable metrology devices.
point cloud A large collection of data points of a three-dimensional object. Point clouds are typically used to create CAD models of objects.
polygon mesh model A collection of vertices, edges, and faces that defines the shape of an object in 3D space. A polygon mesh model lacks precise surface details.
polygons A two-dimensional figure with at least three straight sides and angles. Polygons are used to make basic 3D models of objects.
portable CMMs A coordinate measuring machine that can be easily carried or moved. Portable CMMs can be used on the factory floor.
projector A device that creates a two-dimensional layer of light. Projectors are used to create reference points for scanners to record.
prototypes A preliminary model of a part or a machine used to evaluate the look and performance of a design. Prototypes are used to determine the specifications for the final part.
quality reports A document of measurement data used for inspection. Quality reports provide the information needed to determine the dimensional accuracy of parts.
red green blue RGB. Three hues of light that can be mixed together to create different colors. Red green blue projectors can create full-color patterns.
resolution The amount of pixels and detail in an image. High-resolution images have better details than lower-resolution images.
reverse engineering A process that captures geometric data of an existing object to convert it to a three-dimensional (3D) computer-aided design (CAD) model. Reverse engineering can be used to create a reproduction based on a part's composition.
single slide projection The process of projecting a two-dimensional pattern onto a surface. Single slide projection usually displays a projected pattern that is randomly generated.
STL A file format type used for making 3D models that provides the surface geometry of an object. STL models are used in rapid prototyping and reverse engineering.
structured light A contrasting light pattern projected onto a scene or object. Structured light is used to capture 3D geometric data during optical scanning.
structured light scanners A portable measuring device that projects a pattern of light on an object and scans an image of it to record 3D surface measurements. Structured light scanners may take several scans before gathering all the dimensional data.
three-dimensional 3D. Having or appearing to have length, breadth, and depth. Three-dimensional models show an object's shape better than two-dimensional (2D) drawings.
tolerance An unwanted but acceptable variation or deviation from a desired dimension. A part within tolerances will meet specifications and pass inspection.
triangulation The process of determining the location of a point by forming triangles from the light source to a known point to a sensor. Triangulation is the main process used for capturing data with 3D scanners.
two-dimensional 2D. Having length and width, but not depth. Flat shapes are two-dimensional.
wavelengths The length of a light wave. Wavelengths determine the color and visibility of the light.
white light The combination of all wavelengths of the visible spectrum of light. White light tends to create 3D scans with a lot of noise.