Patent ID: 7087543
Filing Date: 2006-08-08
Classification: C03C,Y10S

Abstract:
1. An optical glass which comprises, by mol %, 22 to 40% of B 2 O 3 , 12 to 40% of SiO 2 , 2 to 20% of Li 2 O, 5 to 15% of CaO, 2 to 14% of ZnO, 0.5 to 4% of La 2 O 3 , 0 to 3% of Gd 2 O 3 , 0 to 3% of Y 2 O 3 , the total content of La 2 O 3 , Gd 2 O 3 and Y 2 O 3 being at least 1%, 0 to 5% of Al 2 O 3 , 0 to 3% of ZrO 2 and 0 to 5% of BaO, the total content of the above components being more than 96%, said optical glass having a refractive index (nd) of 1.57 to 1.67, an Abbe's number (νd) of 55 to 65 and a glass transition temperature (Tg) of 550° C. or lower and having a haze value of 3% or less in terms of climate resistance.