| 摘要 |
FIELD: physics. ^ SUBSTANCE: lens comprises four-series arranged components. The first and fourth components are positive menisci. The second component is a negative meniscus. The third component is a plane-concave lens whose concave side faces the object, and its optical power is minus (0.1-0.5) times the optical power of the large-aperture lens. The fourth component can move along the optical axis and its optical power is (1-2) times the optical power of the large-aperture lens. The following conditions are satisfied: N1=N4, N2=N3, à1=à4, à2=à3, where N and à is the refraction index and the dispersion of the components, respectively. ^ EFFECT: high aperture ratio of the lens, easy assembling with optical workpieces and simple design of the lens, while preserving good optical properties. ^ 1 dwg, 1 tbl |
