Optical glass and optical element

Abstract

The invention provides optical glass and an optical element. The optical glass comprises following components by weight percent of oxides: 3-16% of SiO2, 2-15% of B2O3, 10-25% of sigma (SiO2 and B2O3), 38-55% of La2O3, 0-10% of Y2O3, 0-10% of Gd2O3, 45-65% of sigma (La2O3 and Y2O3 and Gd2O3), 3-15% of ZnO, 0-5% of Ta2O5, 4-10% of Nb2O5, 0-5% of TiO2, 2-10% of ZrO2, and 0-0.2% of Sb2O3, wherein SiO2 or B2O3 is greater than 1 and less than or equal to 2. The optical glass contains no oxides of alkali metal and alkaline-earth metal, such as Yb2O3, WO3, GeO2, TeO2, thorium, lead, arsenic, cadmium and mercury. The optical glass has the refractive index nd in 1.89-1.92, abbe number upsilon d in 36.5-39, specific gravity less than 5.10g/cm<3>, glass-transition temperature lower than 680DEG C, low devitrification tendency and high transmittance, the transmittance can reach over 70% in 390nm or shorter wave length, the devitrification temperature is lower than 1150DEG C, so that the optical glass is suitable for volume production and is mainly used in digital products, cameras, liquid crystal projection and the like. The optical element is made of the optical glass.

Description

technical field [0001] The invention relates to an optical glass, in particular to a kind of glass whose refractive index (nd) is in the range of 1.89-1.92, Abbe number (υd) is in the range of 36.5-39, and the specific gravity is lower than 5.10g / cm 3 , the glass transition temperature Tg is lower than 680°C, and the high refractive index optical glass with a transmittance of more than 70% at a wavelength of 390nm or shorter, the expansion coefficient (α 20～120℃ ) less than 80×10 -7 / ° C, the crystallization temperature is lower than 1150 ° C, and involves optical components. Background technique [0002] In optical system design, high refractive index glass or aspheric lens sheets are usually used to promote the realization of miniaturization, ultra-thinning and wide-angle of digital cameras and mobile phone cameras. The use of this type of glass with a high refractive index of 1.89-1.92 and a relatively high Abbe number can reduce the number of lenses used in optical de...

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Problems solved by technology

Which contains 0.5 ~ 15 mol% Li 2 O, due to the use of Li 2+ The accumulation effect is not conducive to the reduction of the upper limit temperature of glass crystallization, which increases the difficulty of glass melting, increases the expansion coefficient of glass at the same time, and reduces the thermal shock resistance of glass

[0007] Chinese patent application CN1472154A discloses an optical glass with a refractive index of 1.8

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