Machine Vision Lighting for the Automotive Industry

The Physical Problem

Most automotive components are specular or semi-specular: bare metal, machined surfaces, welds and painted panels all reflect light in a fairly narrow, mirror-like cone rather than scattering it evenly in every direction. Under generic diffuse lighting, the exact reflection the camera sees depends heavily on the part's precise angle and position — a slight shift from one cycle to the next on a conveyor or robotic cell can turn a strong, usable signal into a saturated hot spot or a dark dropout, making a single fixed threshold unreliable across the run.

The Optical Solution

The fix is to match the lighting's geometry to what the defect actually is, not to the part in general. A weld seam, scratch or machining mark is a local discontinuity in the surface's angle — coaxial or directional lighting reveals it precisely because that angle change makes it reflect differently from the surrounding specular surface, showing up as a clear bright or dark deviation. A curved, painted body panel instead benefits from diffuse dome lighting, which illuminates it from every angle at once and removes the position-dependent hot spots that a directional source would otherwise create — trading the search for one perfect fixed angle for a lighting geometry that stays consistent even as the part's position varies slightly cycle to cycle.

Integration Tools

• Strobe & Overdrive Lighting
• M12 5-Pin Wiring Diagram