LIGHTING DEVICE FOR A MOTOR VEHICLE HEADLIGHT

Illumination device for a motor vehicle headlight, wherein the illumination device comprises at least one light source and a projection lens system, which projection lens system is designed to project the light in the form of light distribution in front of the illumination device in a main emission direction (X), and wherein the projection lens system consists of the following:a first lens (100) having a first focal point, which first lens (100) is aspherical and made from precision glass by means of precision glass moulding, wherein the first lens has a convex exit surface and a concave entry surface to increase the light entry, wherein the first lens has a refractive index of n≥1.8,a second lens (200) having a second focal point, which is made of glass by means of glass grinding,a third lens (300) having a third focal point, which is designed as an aspherical biconcave lens made of plastic,a fourth lens (400) having a fourth focal point, which is designed as an aspherical biconvex converging lens made of plastic, anda screen (500), which is arranged between the third and fourth lens (300, 400),wherein the second and third lens (200, 300) are designed so as to interact as an achromatic lens pair in order to prevent chromatic aberration, wherein the third and fourth lens (300, 400) have substantially the same thermal expansion coefficient, wherein the third and fourth lens (300, 400) are designed to interact as an athermal lens pair in order to prevent a displacement of the common focal point at different temperatures.