LENS WITH INVARIANT MODULATION TRANSFER FUNCTION (MPF) Russian patent published in 2009 - IPC G02B13/00 G02B9/34 

FIELD: physics, optics.

SUBSTANCE: lens consists of four single-lens components serially arranged along optical axis: power lens, two menisci, correction component, and also flat-parallel plate. Front surface of flat parallel plate, on which phase relief is applied, is joined with the plane of aperture diaphragm (AD). Structure of lens is quaissymmetric relative to AD plane, which is located inside the lens. Profile of phase relief depth is orthogonal relative to transverse coordinates in AD plane and depends on four rational parametres A_x, A_y, B_x, B_y : F(x,y)=F(x)+A(y), mm; F_x(x)=A_x(x/x_max)^Bx; F_y(y)=A_y(y/y_max)^By. Parametres of mask profile are selected in the ranges A_X≈A_y=0.007…0.012 mm; B_X≈B_y=2.4…2.9, and x_max, y_max - maximum light dimensions of mask.

EFFECT: production of invariant MPF in wide range of shooting distances at higher illumination.

5 dwg