Optical glass used for precision mould pressing, glass prefab, optical element and optical instrument

Abstract

The invention provides high-refraction low-dispersion optical glass used for precision mould pressing, a glass prefab formed by the optical glass, an optical element formed by the optical glass, and an optical instrument formed by the optical glass. The optical glass comprises following components by weight: 1-10% of SiO2, 10-25% of B2O3, 15-35% of La2O3, 10-35% of Gd2O3, 1-20% of ZnO, and at least one selected from LaF3, GdF3 and YF3. The refractive index of the optical glass is 1.75-1.82 and the Abbe number of the optical glass is 45-52. F<-> is introduced by utilization of a manner of combining with rare earth elements, and therefore the low dispersion performances required of the optical glass can be achieved and the uniformity and consistency of the glass can be increased. By a reasonable design of the combination ratio of the Li2O, the ZnO and the F, stability of the glass can be improved effectively, the quality level of the glass can be increased and the transistion temperature of the glass can be reduced, thus facilitating compression molding.

Description

technical field [0001] The invention relates to an optical glass, in particular to an optical glass for precision molding with a refractive index of 1.75-1.82 and an Abbe number of 45-52, as well as preforms, optical elements and optical instruments made of the optical glass. Background technique [0002] In recent years, all kinds of optoelectronic products are increasingly pursuing miniaturization, high performance and multi-functionality, which requires optical components such as lenses used in optical systems to also be miniaturized and lightweight. Since the use of aspheric elements can eliminate spherical aberration and reduce the number of optical elements, the use of aspheric elements has become the mainstream in optical design. [0003] In aspheric molding, the commonly used method is precision molding. The so-called precision compression molding is to mold a glass preform with a high-precision mold with a predetermined product shape under a certain temperature and...

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Problems solved by technology

[0005] Japanese Patent Application Laid-Open No. 2002-128539 discloses a high-refraction, low-dispersion optical glass. Since the glass does not contain or only contains a small amount of components such as ZnO or F that can effectively reduce the glass transition temperature, this glass High glass transition temperature (Tg), not suitable for compression molding

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