A beam forming device produces a linear intensity distribution on a work plane. The device contains a laser light source that can emit laser radiation, an optical device that can transfer the laser radiation in a linear intensity distribution on the work plane, and lens that are used to influence the linear intensity distribution on the work plane and that can be displaced in the direction of diffusion of the laser radiation. The intensity profile can be modified perpendicular to the extension of the linear intensity distribution by modifying the position of the lens in the direction of diffusion of the laser radiation.