Automated sorting of tobacco leaves into two groups - by polychromatic illumination and spectral analysis of reflected light

摘要

Both groups are passed by an optical source of polychromic illumination. The reflected light is measured in the green, orange, red and infrared spectral regions. Ratios of values corresp. to green and orange and red and infrared are formed. The values for the four regions are summed whilst the value for infrared reflected from each leaf exceeds a threshold and the number of measurements counted over this period. Leaves for which the count exceeds a threshold or the ratios lie outside defined limits are eliminated using a delay corresp. to the speed of motion starting from when the infrared value exceeds the associated threshold.