METHOD OF MAKING OPTICAL ARTICLES WITH SMOOTH CHANGE IN OPTICAL APERTURE CHARACTERISTIC Russian patent published in 1995 - IPC

FIELD: optical instrument engineering. SUBSTANCE: thicknesses of glass layers are changed along radial direction by means of hot moulding. Glasses are used with different characteristics: refractivities or optical densities, as a result, optical properties are changed for aperture of item, i.e. changeable optical thickness or variable transmission. Glasses are selected to have similar thermal expansion coefficients. Preset change in thickness is got by compacting when using pressing tools. The thicknesses are calculated by using equidistance principle and preset configuration of boundary surfaces of the glasses for depth which takes thinning of mould into account at hot moulding. The blank after being cooled is treated till getting flat-parallel plate or till getting lens with preset radius. EFFECT: improved reliability; improved efficiency. 6 cl