Patent ID: 8164612

Claim:
A light source unit which is used together with a laser beam condensing element for condensing laser beams, comprising: a light source which emits the laser beams; a phase type optical element which includes a first region that modulates a phase distribution of the laser beams emitted from the light source and includes at least one second region where a portion of the laser beams emitted from the light source are transmitted through an entirety of the phase type optical element without the laser beams being modulated; and an aperture having an opening which controls a width of the laser beams input to the phase type optical element or output from the phase type optical element; wherein the phase type optical element has a phase distribution so that a first ratio of a peak intensity of side lobe laser beams to a peak intensity of main lobe laser beams in a beam intensity profile at a focal position of the laser beam condensing element is greater than a second ratio of the peak intensity of side lobe laser beams to the peak intensity of main lobe laser beams in a beam intensity profile at the focal position of the laser beam condensing element when the phase type optical element is not disposed and an area of the first region is less than or equal to half of an area of the opening of the aperture.