Borosilicate optical glass and an optical element

Abstract

The invention provides borosilicate optical glass the refractive index (nd) of which is 1.48-1.52 and the Abbe number (vd) of which is 63-70, a prefabricated member formed by the optical glass and an optical element formed by the optical glass. Based on oxides, the borosilicate optical glass comprises 60-75% by weight of SiO2, 5-15% by weight of B2O3, 1-8% by weight of Al2O3, 0-2% by weight of Li2O, 0-10% by weight of Na2O and 0-13% by weight of K2O, and is free of La2O3. Through reasonably arranging contents of components, the glass transition temperature Tg of the optical glass is low, compression moulding forming temperature is lowered, chemical stability of the glass is good, and corrosion marks influencing transmission of light and imaging quality are not liable to generate on the surfaces of the glass when the glass is used. The optical glass, the prefabricated member and the optical element can be widely applied in mobile optical video equipment, such as a card camera, a mirrorless interchangeable-lens camera, a camera phone and an event data recorder.

Description

technical field [0001] The invention relates to a borosilicate optical glass and an optical element, in particular to a borosilicate optical glass with a refractive index nd of 1.48-1.52 and an Abbe number vd of 63-70, and the optical glass composed of preforms and optics. Background technique [0002] In recent years, with the widespread use of portable optical shooting equipment such as card cameras, single battery cameras, camera phones, and driving recorders, people's demand for miniaturization and light weight of optical equipment is increasing. Aspherical lenses are more and more used in various new movable optical shooting devices because of their lighter weight, smaller size and better imaging effects than traditional lenses. [0003] There are mainly two processing methods of aspherical lenses: precision polishing and precision molding. Among them, precision molding has the characteristics of low cost, stable quality, and mass production, so it is widely used. The...

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Problems solved by technology

[0005] CN102947234A discloses a low-refraction and low-dispersion optical glass, which has a lower Tg, but in order to achieve a lower Tg temperature, a large amount of B must be added to the glass 2 o 3 and R 2 O, will make the chemical stability of the glass drop sharply

Although more Al is added to improve the chemical stability of the glass in the patent literature 2 o 3 , but the chemical stability of the glass is still unsatisfactory

[0006] CN101213150B discloses an optical glass used in optical communication devices, containing 70-85% SiO 2 and 1-7% Al 2 o 3 , which will make it very difficult to melt the raw materials, and the high temperature viscosity of the glass liquid is high, it is difficult to eliminate the bubbles, and the production of the glass is difficult

[0007] CN100430329C discloses a kind of optical glass with Tg≤500℃, containing 16-20% Al 2 o 3 , which will cause the surface tension of the glass liquid to increase significantly, making it difficult to eliminate air bubbles, resulting in greater difficulty in glass production

The raw material of complex phosphate is expensive, and free P 2 o 5 Corrosion to crucibles and refractories can lead to poor glass interior quality

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