| 摘要 |
PROBLEM TO BE SOLVED: To provide an uniform optical system, capable of illuminating without a interference unevenness even when laser beams are used as a light source. SOLUTION: This optical system comprises an illumination optical system 32, having an integrator unit 32c comprising a plurality of lens elements 40 forming an illumination light as a uniform light and a condenser lens 32d, and an accumulated CCD line sensor 35 for measuring the intensity of lights from this illumination optical system 32. Here, an arrangement direction of the lens elements 40 of the integrator unit 32c and an arrangement direction of the accumulated CCD line sensor 35 are inclined at a predetermined angleαand arranged about an optical shaft of the illumination light. When the number of lines of the accumulated CCD line sensor 35 is (n), a line pitch is (p), a pitch of interference strips on the accumulated CCD line sensor 35 is (d), and a natural number is (m), the angleαis shown by a product of (m)and arcsin (d/np), namelyα=mXarcsin (d/np). |
