| 摘要 |
<p>A diffraction lens element (6) having both optical actions of a random phase plate and a lens array and a lighting system using the element capable of reducing the number of speckles and increasing an energy efficiency and a light utilization efficiency; the diffraction lens element (6), wherein the amounts of variation according to random numbers are added to or superimposed onto the depths of recessed parts forming a step equivalent to a lens or the lens array to form the recessed parts having irregular phase changes in a transparent base material; the lighting system using the element and a laser beam source, wherein the diffraction type lens element (6) is rotated by a rotating means to provide uniform illuminating light without speckles.</p> |
