| 摘要 |
A device for contactless optical distance measurement is described, comprising a polychromatic light source (3), a light analysis unit (4) and a measurement head (5), wherein the measurement head (5) has an aperture opening (6) and an optical lens system (12) which has a chromatic longitudinal aberration. The optical lens system (12) consists of a first refractive lens element (1) and a second refractive lens element (2), wherein at least one of the refractive lens elements (1, 2) has at least one aspherical lens surface (11), and the first refractive lens element (1) and/or the second refractive lens element (2) has an optical material with an Abbe number 20 ≤ V d ≤ 41. The optical lens system (12) has such a chromatic longitudinal aberration that a measurement region (MR), which equals an axial focal shift of the optical lens system (12) between the wavelengths of 450 nm and 700 nm, is between 0.2 mm inclusive and 10 mm inclusive. |
