Optical glass, glass preform, optical element and optical instrument

Abstract

The invention provides optical glass with a refractive index of 1.65-1.79 and an Abbe number of 48-56, wherein the optical glass comprises the following components in percentage by weight: 10-30% of SiO2, 5-20% of B2O3, 10-35% of Al2O3, 15-40% of La2O3, 10-45% of Y2O3, 0.5-8% of ZrO2 and 0.5-8% of MgO, wherein Al2O3 / SiO2 is 0.4-2.0%. Through the reasonable component design, the optical glass obtained in the invention has expected refractive index, expected Abbe number and expected refractive index temperature coefficient, also has high hardness and excellent chemical stability, and is suitablefor use in the fields of vehicle-mounted, monitoring security and the like.

Description

technical field [0001] The invention relates to an optical glass, in particular to an optical glass with a refractive index of 1.65-1.79 and an Abbe number of 48-56, as well as glass preforms, optical elements and optical instruments made of the optical glass. Background technique [0002] Lanthanum-containing optical glass with a refractive index of 1.65-1.79 and an Abbe number of 48-56 belongs to lanthanum crown glass. Compared with ordinary crown glass, it has the advantages of high refractive index and low dispersion. It can be used in optical imaging systems to greatly Significantly increase the field of view of the lens and improve the image quality. [0003] With the development of smart driving technology, smart security technology, and environmental perception technology, different from traditional lenses (such as SLR cameras) that work in a better environment, lenses in the above fields need to be exposed to harsh conditions such as wind and sand, acid rain, and hi...

AI Technical Summary

Problems solved by technology

At present, lanthanum crown glasses are mainly composed of B 2 o 3 -La 2 o 3 System composition, the acid resistance of the powder method can only reach Class 3 or lower, and it is easy to be corroded by acidic substances when used under long-term harsh conditions, which is difficult to meet the requirements of the vehicle field.

[0006] Since the refractive index of glass material changes with temperature, this property is called the temperature coefficient of refractive index of glass. If the temperature coefficient of refractive index of glass is too large, when the working temperature changes greatly, such as a car driving in a cold zone Surveillance camera lenses in tropical and alpine regions, high-temperature furnace observation lenses, etc., the lens cannot be accurately focused, resulting in reduced clarity

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