Improvements relating to the Correction or Variation of Spherical Aberrations in Dioptric Lens Systems.

摘要

7417. Goerz, C. P. April 10. Lenses.-R elates s to a mathematically - deduced method of correcting or reducing the longitudinal aberration in lens systems. In a lens such as that shown in Fig. 1, the central axial ray C and the marginal parallel ray R are brought to a common focus at P, but rays passing through the intermediate zones, such as M, intersect the axis in different points, such as P1, within the point P, i.e., the intermediate zones are under-corrected. This zone error is reduced, as shown in Fig. 2, by introducing a second cement surface S of great curvature between two lenses of but slightly different refractive power. This second surface may also be made in the diverging component of the combination. Fig. 4 represents the application of the principle of the correction to the object glass of a telescope. The elements of construction are as follows :- As an example, the principle is also shown applied to a lens of the type described in Specification No. 23,378, A.D. 1892, [Abridgment Class Photography]. In the case of a doublet, the mean zone of one of the components may be undercorrected, while the other is correspondingly overcorrected. The principle may be applied to lenses generally, such as those for telescopic, microscopic, and photographic purposes.