Compare Profilometer Technology
Pattern Projection combined with Focus Detection is generally faster than the other scanning techniques because only Z motion is required. This method also improves height resolution to be comparable or better than scanning techniques. This method is incorporated into Zeta 3D ZDot focusing technology, using a confocal grid structured array illumination (CGSI) to measure almost any surface.
Pattern Projection compares a projected known pattern to the reflected pattern.
Focus Detection provides 3D imaging at lower resolution than confocal or interferometry.
Interferometry uses an interference fringe and is best suited for smooth, reflective surfaces. Interferometry has a large field of view (FOV) but is sensitive to vibrations.
Confocal microscopy can be slow and sensitive to vibration. Confocal laser scanning microscopy may require a trained operator and periodic calibration. Because the source is a laser, imaging artifacts are possible and 3D data is false color.
Pattern Projection with Focus Detection
Combination of pattern projection and focus detection
Differences in projected patterns generate 3D images
Create 3D images using focal planes
Principles and schematic of interferometry
Principles and schematic of confocal profilometry