METHOD OF DESIGNING GROUP OF BI-ASPHERICAL LENSES WITH GRADUAL INCREASE OF FOCAL POWER AND GROUP OF BI-ASPHERICAL LENSES WITH GRADUAL INCREASE OF FOCAL POWER Russian patent published in 2009 - IPC G02C7/06 

FIELD: physics; optics.

SUBSTANCE: invention relates to optical instrument making and is aimed at providing a group of bi-aspherical lenses with gradual increase of focal power with low processing expenses. This outcome is achieved due to that, in bi-aspherical lenses with gradual increase of focal power the expressions DHf+DHn<DVf+DVn and DHn<DVn are satisfied, as well as additionally DVn-DVf>ADD/2 and DHn-DHf<ADD/2. DHf and DVf are defined as the refractive focal power of the surface in the horizontal direction and refractive focal power of the surface in the vertical direction in position F1 for measuring focal power of vision afar on the first refracting surface, which acts as the surface on the side of the object. DHn and DVn are defined as the refractive focal power of the surface in the horizontal direction and refractive focal power of the surface in the vertical direction in position N1 for measuring focal power of vision nearby on the first refracting surface. Component of astigmatism of the surface in F1 and N1 of the first refractive surface is eliminated using the second refracting surface on the side of the eye, and the first and second refracting surfaces are combined so as to provide focal power of vision afar (Df) and ADD power (ADD) based on design. An identical first refracting surface is used, for example for two or more different types of additions.

EFFECT: provision for a group of bi-aspherical lenses with gradual increase of focal power with low processing expenses f.

3 cl, 24 dwg