Method for making optical preforms and optical elements by press molding

摘要

A method for making optical preforms of optical elements without residual stress or distortion is provided. In this method, an optical material (6) is supplied between upper and lower molds (1,2). The upper mold (1) has a plurality of recesses arranged in a predetermined pitch, and each recess corresponds to a first surface shape of the optical element. The lower mold (2) has a plurality of recesses facing the recesses of the upper mold (1) and each recess of the lower mold corresponds to a second surface shape of the optical element. The supplied optical material (6) is pressed between the upper and lower molds (1,2) to be a set of optical preforms (7). The set of optical preforms (7) is processed by die punching or tool cutting to separate each optical preform from the set of optical preforms (7). Each optical preform is used for producing an optical element by further pressing. Alternatively, optical element can be formed directly by the press molding process.