Integrated air guide and beam shaping

A lighting unit comprising a light mixing chamber defined by faces and an edge face, wherein a height of the light mixing chamber defined by a distance between the faces is smaller than a first length of the light mixing chamber, wherein the lighting unit comprises a plurality of at least ten light sources configured to provide light source light in the light mixing chamber, wherein at least one of the faces comprises a plurality of chamber openings for escape of at least part of the light source light from the light mixing chamber, wherein the chamber openings have a length equivalent to the thickness of the face comprising said chamber openings, and have a shape and/or diameter that varies with the length,

• wherein the lighting unit further comprises a plurality of beam shaping elements, with each beam shaping element configured downstream from a corresponding chamber opening, and wherein the beam shaping elements comprise reflectors,
• wherein the plurality of at least ten light sources are configured in an evenly distributed manner at the edge face and are configured to provide said light source light having an optical axis perpendicular to the height, and
• wherein the beam shaping elements are configured in a pseudo random pattern.