METHOD OF MAKING MASTER MODEL FOR MAKING FLAT SPHERICAL FRESNEL LENS (VERSIONS) Russian patent published in 2009 - IPC B29D11/00 G02B3/08 

FIELD: physics.

SUBSTANCE: method of making master model for making a flat spherical Fresnel lens involves initial mechanical processing of a work piece from solid non-deformable material so as to obtain the reverse of the desired profile of the lens. For this purpose two work pieces are processed to make identical reverse spherical profiles, after which each is conventionally divided into n layers which form planes perpendicular the principal optical axis. Even layers, including the centre, are cut from the first work piece, and odd layers are cut from the second work piece, after which a cylinder is cut from each layer, the axis of which coincides with the principal optical axis, and the outer diametre is equal to the diametre of the largest opening of the corresponding layer. The obtained elements are attached by flat faces on the non-deformable flat surface symmetrically with the principal optical axis, after which a protective layer is deposited on a shaping surface.

EFFECT: invention simplifies making a master model for making Fresnel lenses and allows for doing without high-precision equipment in making the master model, while retaining accuracy of making spherical surfaces.

2 cl, 4 dwg