Lighting System

The Lighting System is a critical component within an Automated Optical Inspection (AOI) System. Its primary function is to illuminate the target object (e.g., a printed circuit board, semiconductor wafer, or mechanical part) with specific light characteristics (intensity, angle, wavelength, uniformity) to enhance contrast, reveal surface defects, highlight features of interest, and minimize shadows or glare. This controlled illumination is essential for the AOI system's cameras and sensors to capture high-fidelity images for subsequent analysis, measurement, and defect detection algorithms.

The system typically consists of multiple light sources (e.g., LEDs, halogen lamps) arranged in specific geometric configurations (ring lights, dome lights, backlights, coaxial lights). These are controlled by a driver/controller that adjusts parameters like brightness, strobe timing (synchronized with camera capture), and sometimes color temperature or specific wavelengths. The light is directed onto the inspection target. Different lighting techniques (bright-field, dark-field, diffuse, structured) are used to accentuate different types of surface features, textures, or defects, making them clearly visible to the imaging system.

Typical specifications include luminous flux from 3000 to 10000 lm, color temperature from 5000 to 6500 K, color rendering index ≥90, illuminance uniformity ≥0.8, input voltage 100–240 V AC, power consumption 50–200 W, operating temperature -10 to 50 °C, storage temperature -20 to 70 °C, ingress protection IP54–IP65, weight 2–8 kg, dimensions from 300×200×100 to 600×400×200 mm, and lifetime 50000 hours (L70). These values are reference ranges and must be verified for the specific model and application with the legal manufacturer or supplier. Standards such as ISO 8995, CIE S 014, CIE 13.3, IEC 62368-1, IEC 62301, IEC 60529, and IES LM-80 are procurement references, not proof of certification or compliance. IEC 60068-2-1 addresses cold tests and IEC 60068-2-2 dry-heat tests; neither establishes the listed operating or storage temperature range.

The system uses multiple light sources (e.g., LEDs) arranged in configurations like ring, dome, backlight, or coaxial. A driver/controller adjusts brightness, strobe timing (synchronized with camera capture), and sometimes color temperature or wavelength. Light is directed onto the inspection target. Techniques such as bright-field, dark-field, diffuse, or structured lighting accentuate different surface features, textures, or defects, making them visible to the imaging system.