Optical glass suitable for secondary profiling and aspheric precision profiling

Abstract

The invention relates to optical glass suitable for secondary profiling and aspheric precision profiling, and belongs to the technical field of optical glass. The optical glass is prepared from the following components in parts by mole: 10 to 40 parts of Ge and Ga, 30 to 65 parts of S, Se and Te, 5 to 18 parts of La2O3, 3 to 10 parts of Y2O3, 0 to 12 parts of ZrO2, 10 to 15 parts of Nb2O5 and 0.5to 6 parts of WO3. According to the invention, the internal transmittance tau 400 nm of the glass at a wavelength of 400 nm is greater than 78%, the Tg temperature is lower than 700 DEG C, the crystallization upper limit temperature is not higher than 1200 DEG C, the viscosity at 50 DEG C above the crystallization upper limit temperature is greater than 1.5 dPaS, the viscosity at 50 DEG C above the crystallization upper limit temperature of the glass is greater than 1.75 dPaS, and the glass transition temperature (Tg) of the optical glass is 260 DEG C to 750 DEG C; the produced glass with thethickness of more than 25 mm is not easy to generate crystallization and stripes, has high yield, is suitable for secondary profiling, does not influence the previous forming quality, and does not influence the refractive index, Abbe number and other factors of the optical glass; and the optical glass has low principle cost, does not contain substances harmful to human bodies, and is suitable forpopularization.

Description

technical field [0001] The invention relates to an optical glass suitable for secondary pressing and precision pressing of aspheric surfaces, and belongs to the technical field of optical glass. Background technique [0002] At present, there are two main types of glass aspheric molding: isothermal and different temperature molding. The so-called isothermal: put the glass blank into the mold, and heat and press the multiple molds to soften the glass (note that it is not liquefied), so that the glass blank becomes The shape of the mold, then cool the mold, and take out the product; the so-called different temperature molding: it is to heat the glass blank before entering the mold to soften (not liquefy), and then send it into the molding environment, pressurize the mold to make the glass blank The embryo becomes the shape of the mold, and then it is taken out after cooling (note that the different temperature forming mold keeps a constant temperature). Simply speaking, isoth...

AI Technical Summary

Problems solved by technology

[0005] At present, the application field of optical glass is constantly expanding, and the processing technology of optical glass is also continuously improved. Many optical glasses need secondary pressing; but the existing optical glass is basically formed at one time, and the subsequent pressing will change. The quality of its first molding will also affect the optical glass's previously measured refractive index, light transmittance, Abbe number, etc.