Optical glass, prefabricated part for precise compression molding and optical element

Abstract

The invention provides optical glass for precision compression, a preformed unit for precision compression and an optical element, wherein the nd is between 1.65 and 1.75, vd is between 50 and 60 and the transformation temperature Tg is less than 540 DEG C. The optical glass comprises the following compositions by weight percentage: 0 to 15 percent of SiO2, 28 to 43 percent of B2O3, 21 to 35 percent of La2O3, 0 to 15 percent of Gd2O3, Y2O3 and Yb2O3, 3 to 13 percent of ZnO, 1 to 8 percent of Li2O, Na2O and K2O, 1 to 20 percent of MgO, CaO, SrO and BaO, 0 to 8 percent of ZrO2, 0 to 0.1 percent of Sb2O3, 0 to 0.5 percent of SnO2, and 0 to 3 percent of Ta2O5, WO3, Nb2O5 and TiO2. The optical glass prolongs the service life of a mould, realizes high-efficiency production, and simultaneously can also reduce the production cost of the optical element.

Description

technical field [0001] The invention relates to an optical glass, a preform for precision molding and an optical element. More specifically, the invention relates to a glass with a refractive index (nd) of 1.65-1.75 and an Abbe number (vd) of 50-60 At the same time, the optical glass with a transition temperature Tg below 540°C has excellent precision molding properties, and the precision molding preform and optical element composed of the above optical glass. Background technique [0002] In recent years, with the rapid popularization and use of digital cameras, video cameras and mobile phones that can take pictures, the optical system is also developing rapidly in the direction of high precision, light weight and miniaturization. To meet the above requirements, optical design using aspheric lenses is becoming mainstream. More and more attention has been paid to precision molding technology for mass and stable production of aspheric lenses at a lower cost, and the demand f...

AI Technical Summary

Problems solved by technology

Optical glass with low softening point for precision molding requires optical glass with various optical constants. For optical glass with high refraction and low dispersion, a certain amount of La2O3 is usually used, but too much content will easily cause the glass transition temperature (Tg) to rise, which is not conducive to Precision molding

In order to lower the glass transition temperature, a large amount of alkali metal oxides are often introduced into the glass, but at the same time, the stability of the glass will deteriorate

Therefore, for high-refraction and low-dispersion glass, it is extremely difficult to prevent damage during molding and take into account both low-temperature softening and stability.

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