| 摘要 |
PROBLEM TO BE SOLVED: To provide an illumination optical system which regards uniformity in illumination as important and further, is capable of adjusting uniformity and luminance in illumination, as needed. SOLUTION: The illumination optical system (100) which irradiates a sample surface (O) with a light through an illuminating lens (L6) includes a light source (S): a condensing optical system (L1) receiving incident light emitted from the light source; and a lens array optical system, including a first lens array surface (LS1) and a second lens array surface (LS2) each formed by a plurality of lens elements. The first lens array surface (LS1) is of a conjugate relation with a back focal position of the illuminating lens (L6). The second lens array surface (LS2) is placed at a back focal position of the lens array optical system, and has a conjugate relation with a pupil position (E1) of the illuminating lens (L6). The light source (S) and the condensing optical system (L1) are arranged, so as to form an image of the light source (S) on the first lens array surface (LS1). COPYRIGHT: (C)2011,JPO&INPIT |
