Rgb camera scanned illumination

A method for inspecting objects passing through an inspection area wherein the method comprises:

• providing:
• at least a first elongated inspection zone comprising at least a portion of said inspection area, said at least a first elongated inspection zone having a longitudinal extension and a transversal extension,
• at least one object and passing said at least one object through said inspection area,
• an irradiation arrangement configured to emit optical radiation within at least a first wavelength range,
• a camera arrangement comprising a camera having a plurality of sensor pixel lines, and where a field of view of said camera is static with respect to said inspection area,
• a polygon mirror configured to rotate around a rotation axis and comprising a plurality of reflective surfaces arranged one after another around said rotation axis,
• at least one image processing unit,
• emitting, by said irradiation arrangement, optical radiation within said at least a first predetermined wavelength range,
• redirecting, by a respective one of said reflective surfaces of said polygon mirror, optical radiation originating from said irradiation arrangement towards a portion only of said inspection area, wherein said irradiated portion covers the entire transversal extension of said at least a first elongated inspection zone,
• rotating said polygon mirror and thereby causing said irradiated portion to move along said longitudinal extension of said at least a first elongated inspection zone from a first irradiated end to a second irradiated end of one of, or all of, said at least a first elongated inspection zone once per reflective surface and revolution of said polygon mirror,
• capturing, by said camera, a sequence of images of said at least a first elongated inspection zone, where
• during said capturing, said transversal extension of each one of said at least a first elongated inspection zone covers a plurality of said sensor pixel lines,
• each image in said sequence of images is a representation of at least a portion of said objects when present in said at least a first elongated inspection zone,
• each image in said sequence of images is captured with an exposure time corresponding to the time required for said irradiated portion to move along the longitudinal extension of one of said at least a first elongated inspection zone from said first irradiated end to said second irradiated end of said at least a first elongated inspection zone, and
• combining, by said at least one image processing unit, the images in said sequence of images to form an output comprising a representation of the at least one object passing through said inspection area.