Multi-color surface inspection system, method for inspecting a surface, and method for calibrating the multi-color surface inspection system

A multi-color system for optically inspecting a surface of a specimen, the system comprising:

• a multi-wavelength light-emitting diode (LED) array including a plurality of LEDs, each of the plurality of LEDs emitting monochromatic light, the multi-wavelength LED array being configured to illuminate the specimen with a multi-color light pattern, the multi-color light pattern including simultaneously emitted spatial intensity color image patterns, each of the simultaneously emitted spatial intensity color image patterns including first areas in which light is emitted with a first light intensity and second areas in which the light is emitted with a second light intensity, the first light intensity being higher than the second light intensity, and corresponding first and second areas in each of the simultaneously emitted spatial intensity color image patterns being phase-shifted relative to each other;
• a multi-color sensor configured to capture each of the simultaneously emitted spatial intensity color image patterns reflected from the surface of the specimen in a single wavelength-multiplexed sensor image at a scanning position;
• a data processing apparatus in communication with the multi-color sensor and configured to determine properties of the surface based on an evaluation of the single wavelength-multiplexed sensor image;
• an LED board on which the plurality of LEDs forming the multi-wavelength led array is arranged;
• and
• an LED driver in communication with the multi-wavelength LED array, the multi-wavelength led array including a plurality of LEDs, the plurality of LEDs being arranged in groups of LEDs, and each of the groups of LEDs being controlled by the LED driver to generate one of the simultaneously emitted spatial intensity color image patterns, wherein a first group of LEDs has a red wavelength regime, a second group of LEDs has a green wavelength regime, and a third group of LEDs has a blue wavelength regime, wherein the first, second, and third groups of LEDs are arranged on the LED board in a Bayer pattern.