Since different types of lights produce energy at a variety of frequencies along the photonic spectrum, we first identify the wavelengths that best differentiate good product from defects and foreign material, and then select a light source or combination of light sources that target those wavelengths.
LEDs (light emitting diodes) and lasers are monochromatic in nature—they produce energy at specific wavelengths. Monochromators are available in UV (ultraviolet), visible, and the IR (infrared) regions of the spectrum. In contrast, white light emitted by florescent lamps produce multiple narrow-band output wavelengths, while HID (high intensity discharge) illumination produces energy across a broad spectrum including IR. Most sources produce the majority of their energy within the visible spectrum with some output in the IR range. Specialty lamps are available that produce higher energy levels in a more specific range, for example UV lamps.
At Key, we can combine a variety of lights that produce energy within the visible, IR, and UV spectrums in one optical inspection system to optimize the sorter’s effectiveness for a specific application.