Structured Light Scanning
Fast, accurate full-field 3D capture using projected fringe patterns - the reference technology for sheet metal, tooling, composites and full-surface GD&T.
How it works
A structured-light scanner projects a sequence of fringe patterns (blue LED or laser) onto the part surface. Two calibrated cameras record the deformed patterns and reconstruct millions of 3D points per capture using phase-shifting photogrammetry. Multiple captures are stitched via reference targets or geometric features into a full 3D model.
Typical accuracy
Fixed structured-light systems (GOM ATOS Q / 5, Zeiss COMET) achieve probing errors of 5-15 microns and volumetric length errors of 15-40 microns/metre depending on measurement volume and configuration.
Applications
- Sheet-metal panel and press-tool inspection
- Composite lay-up and cured-part inspection
- Injection-mould and die validation
- Turbine blade and airfoil inspection
- Full-surface GD&T with colour deviation maps
- Reverse engineering of complex freeform parts
Strengths
- • Highest general-purpose accuracy of any optical technology
- • Millions of points per capture - true full-field
- • Fast: seconds per capture, minutes for a full part
- • Non-contact - safe for soft, thin or flexible parts
Limitations
- • Not portable in the handheld sense - tripod or robot-mounted
- • Shiny or dark surfaces may need matting spray
- • Line-of-sight limits deep bore and undercut coverage
- • Higher capital cost than handheld scanners
Fringe projection in plain English
Rather than measuring a single laser line, structured light projects a full 2D pattern and shifts it in phase over a few frames. Every pixel gets an independent 3D measurement - millions per capture, in a couple of seconds. That's the fundamental reason structured light dominates full-surface inspection of press tools, composite parts and turbine blades.
Automating structured light
Modern cells (ATOS ScanBox, Zeiss ScanBox) place the sensor on a robot with a rotary table and light-tight enclosure. Cycle times of 3-10 minutes per part are typical for repeat production inspection, with full CAD-based reporting and SPC.
Buying considerations
- Measurement volume (MV) options and interchangeability
- Sensor certified per ISO 10360-8 / VDI/VDE 2634
- Automation: robot cell, rotary stage, kinematic mount
- Software: GOM Inspect, Zeiss INSPECT, Geomagic Control X
- Blue LED / blue laser for shop-floor light immunity
FAQs
Structured light or handheld laser scanning?+
Structured light for the tightest optical accuracy and repeat production; handheld for portability, on-machine work and mixed part sizes.
Do we need to spray parts?+
Highly reflective or dark parts benefit from matting spray. Most painted, cast or moulded surfaces scan directly with blue-light systems.