Method and system for use in inspecting and/or removing unsuitable objects from a stream of products and a sorting apparatus implementing the same

A sorting apparatus for detecting and removing unsuitable or irregular objects in a stream of products based on forming of a scan line by means of at least one light source directing light along the scan line, and measuring scattered light or directly reemitted light obtained from the objects in the illuminated product stream;

• the apparatus comprising:
• an inspection system comprising means for scanning the stream of products along the scan line, and the scanning means comprising a focusing means for concentrating the light in at least one dimension;
• and
• a detection means configured for detecting light beams reemitted by the product stream upon scanning, which detection means produces an electrical signal proportional to the detected light beams,
• a supply system for transporting the product stream towards the inspection system,
• a control circuit processing the electrical signals from the detection means of the inspection system and converting the electrical signals into a corresponding control signal, and
• a removal unit operated in accordance with the control signals of the control circuitry;
• the detecting means comprising a focusing means defining an image plane in which a spatial image of the stream of products along the scan line is formed, the focusing means being configured to focus the image in at least one dimension and being oriented towards the scan line such that the points on the scan line form a projected scan line along a direction xp in the image plane, and
• the detecting means further comprising a spatial filtering means operating in the image plane, which spatial filtering means filter the image in substantially only the direction perpendicular to the direction of the projected scan line such that the field of view of the detecting means is delimited to predominantly directly reemitted light or predominantly scattered light.

A method for inspecting and sorting objects in a stream of products, the method comprising the steps of;

• a) scanning the stream of products along a scan line, the scan line being formed by means of at least one light source directing a concentrated light along the scan line,
• b) focusing light beams reemitted by the product stream in at least one dimension and forming a focused image in an image plane such that points on the scan line forming a projected scan line along a direction xp in the image plane,
• c) spatially filtering the image substantially located in the image plane with a spatial filtering means in substantially only the direction perpendicular to the direction of the projected scan line such that passage of predominantly directly reemitted component or predominantly scattered component of the image is allowed to pass through the filtering means,
• d) obtaining optical signals received from the filtered image and generating electrical signals representative of both directly reemitted and scattered lights and/or only predominantly directly reemitted light and/or only scattered light, and
• e) receiving the electrical signal(s) of the previous step and generating control signal(s) based on either of both directly reemitted light and scattered light, only predominantly directly reemitted light, only scattered light or combinations thereof.