| 摘要 |
PROBLEM TO BE SOLVED: To provide a diffraction pattern projection optical system that enables adjustment of the angle of diffraction of a transmitting light beam in an optical system using a diffraction element.SOLUTION: A diffraction pattern projection optical system has a coherent or partially coherent light source, a first lens or lens group (hereinafter referred to as first lens), a diffraction element, and a second lens or lens group (hereinafter referred to as second lens) arranged in this order. An incident-side (object-side) composite focus position of a lens group obtained by combining the first lens and the second lens is substantially the same as a divergence origin position or a convergence position, or is arranged on an emission side (image side) of an incident light beam.SELECTED DRAWING: Figure 2 |
