Abstract: A method and apparatus for labeling plant products based on laser activation of a color-changing compound is disclosed. In the preferred embodiment, a nozzle sprays a coating of photosensitive material containing color-changing chemical component. An optional drying station is set up to optimize homogeneity and adhesiveness of the color-changing coating. A laser equipped with beam steering optics is used to image the desired mark on the plant product by inducing a change of color in the photosensitive coating, without contacting the plant product skin and at a high speed. An optional nozzle sprays a sealant coating after printing, for extended durability of the imaged label. In addition, an optical sensor detects the incoming plant product, determines its size and sends information for selecting the proper label to be imaged. An additional optical sensor can be placed at the end of the process to verify the quality and legibility of the imaged label.

Abstract: A method and apparatus of sorting plant products based on damage to the plant products is disclosed. A beam emitter emits an illumination light toward the outer surface of a plant product. A beam detector detects substantially a single wavelength of a reflected light produced by the plant product responsive to the illumination light. A control unit determines at least one of a presence, an amount, and a severity of damage responsive to the reflected light. The control unit assigns a damage category to the plant product responsive to the determination of damage.