RL3940 Folded Beam Dark Field Ring

The RL3940 is a folded beam dark field ring light for defect inspection at very short standoff. An aluminum beam folder turns the output from precisely aimed LEDs back across the surface, holding the low angle of incidence dark field work depends on even with the head almost on the part.

The 100 mm housing accommodates lenses up to 55 mm in diameter, so standard optics look straight through the ring, and an optional mounting ring gives a repeatable reference on refitting. The compact body suits stations with no room to stand a conventional dark field head off the part.

Output reaches up to 11 kLux at a 15 mm working distance, bright enough for short exposures on fast lines, with L70 lumen maintenance at 50,000 hours. The 625 nm, 660 nm and 880 nm builds draw 0.24 A at 24 V and the shorter wavelength and white builds draw 0.16 A, keeping supply sizing simple. The RL3940 range spans the ultraviolet to the infrared; the 246.8 g head runs from 0 to 60 degrees C.