| 摘要 |
PROBLEM TO BE SOLVED: To provide a collimator lens that enables bright illumination at low cost and in which aberration is satisfactorily corrected, an illuminating device, and a microscope.SOLUTION: A collimator lens 1 comprises a biconvex single lens L1 that collimates a light flux emitted from a light source and is formed by a resin material, and at least one surface of the collimator lens is formed of an aspherical surface. When R1 represents the curvature radius of a first surface on the light source side of the collimator lens 1, R2 represents the curvature radius of a second surface opposite to the first surface of the collimator lens 1, and NA represents a numerical aperture on the light source side of the collimator lens 1, the collimator lens 1 satisfies the following inequality expressions: 2<|R1/R2|<10, and NA>0.6. |
