High refraction optical glass and manufacturing method thereof

Abstract

A high-refraction, high dispersion optical glass has high transmittance, low glass density, desirable anti-devitrification, and applicability to repeated pressing in a secondary hot pressing process. The optical glass contains SiO2, B2O3, Gd2O3, Nb2O5, TiO2, BaO, CaO, Ta2O5, ZnO, Li2O, and ZrO2 as essential components, but does not contain Bi2O3. The glass has an index of refraction (nd) of at least 1.88, an Abbe number (Vd) of 23 to 26, a glass density smaller than 4.2g / cm3, and a transition temperature (Tg) lower than 610°C.

Description

technical field [0001] The invention relates to a high refraction and high dispersion optical glass and a method for manufacturing the optical glass. More specifically, the present invention particularly relates to a specific range of optical constants with a refractive index (nd) above 1.88 and an Abbe number (vd) in the range of 23 to 26, and has high transmission and low density , Optical glass with good stability. Background technique [0002] In recent years, with the rapid popularization of SLR cameras and their widespread use in people's lives, the optical materials used in the optical system of SLR cameras have been widely used, especially as high refractive index and high dispersion glass, which not only meets the requirements of The design requirements of the optical system of high-performance digital cameras need to meet the requirements of large-size lenses and high-definition requirements of the optical system of SLR cameras. [0003] Developing an optical gla...

AI Technical Summary

Problems solved by technology

[0007] As for such high-refraction and high-dispersion optical glasses with a refractive index (nd) above 1.88 and an Abbe number (vd) of 23 to 26, there are no known optical glasses with optical properties in this range.

The early patent document CN1204073C introduced the refractive index of the glass within this range, but the glass Abbe number (vd) is greater than 27, and the glass density is high and the resistance to devitrification is poor; CN101012103A, its refractive index (nd) belongs to the scope of the present invention, But the dispersion value is low, the Abbe number is greater than 26 or larger, and as CN1835895A, CN101318769A, although the Abbe number (vd) is 26 or lower, the refractive index (nd) is less than 1.88, which is relatively different from the optical constant of the present invention Large, can not meet the design requirements of the current new SLR camera optical system; In terms of satisfying repeated and repeated hot pressing, no defects appear on the surface of the blank, CN1204073C, CN101012103A, CN1835895A are difficult to overcome the secondary heat due to their high devitrification temperature Foggy spots and opacities formed on the surface of molded parts do not appear during pressing

In addition, improving the stability of glass penetration and manufacturing, and low-cost operation must also be considered, so the above defects are obvious

Images