Many surfaces (such as glass, clear plastic, and mirror-like finishes) create images with extremely low, or worse, nonexistent contrast. A Grid Projector accessory from OGP measures these surfaces.
The Grid Projector works by projecting a grid pattern onto the surface of the part from behind the front objective lens using an LED source. The system is designed so that the image of the grid will only appear in focus when the surface of the part is exactly coincident with the focal plane of the optics.
The autofocus routine can then use the contrast contained in the grid image just as if it were present in the surface of the part and since the autofocus algorithm is finely tuned to the characteristics of the grid image, repeatability is significantly improved.
Grid Projectors are available on most SmartScope systems.
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