小口径薄型玻璃透镜精密模压制造

Precision glass molding process of small aperture thin lens

采用传统的研磨抛光方法很难实现口径与厚度比很大的玻璃透镜的制造,下盘后机械应力变形是影响透镜精度的重要因素之一。而采用玻璃精密模压制造技术,无需透镜毛坯装夹固定机构,在加工过程中几乎不产生机械应力,因此是小口径薄型玻璃透镜的首选制造技术。成功制造了一种口径与中心厚度比为11的薄型透镜,面形精度的PV值和RMS值可分别达到0.41μm和0.08μm,重复精度的PV值优于0.1μm,测量结果表明:该模压透镜具有良好的面形精度,且批量制造的一致性很好,说明采用玻璃精密模压制造技术加工小口径薄型透镜是一种高效可靠的加工方法。

It＇s difficult to manufacture high accuracy thin lenses with large ratio of aperture to thickness with conventional grinding and polishing methods, since the structure strength of those thin lenses can not avoid deformation caused by mechanical stress between lenses and clamping parts. Precision glass molding process （PGMP） was adapted for mass production of small aperture thin lens. No mechanical stress was introduced for the reasons that there were no clamping parts used in the molding process and the thermal stress can be eliminated by fine annealing. A type of thin lens with aperture/thickness ratio 11 was successfully fabricated. As a result, the shape accuracy of these molded lenses was better and could be up to 0.41 μm（PV） and 0.08 μm（RMS）, and the accuracy of repetition was better than 0.1μm（PV）. The results of measurements show that the accuracy of surface geometry and reproduction of molded lenses can meet the requirements of high performance application. It indicates that glass molding technique is an effective and reliable method in manufacturing high precision thin lenses.