Patent 7704904 was granted and assigned to Konica Minolta on April, 2010 by the United States Patent and Trademark Office.
An optical glass contains as glass ingredients, by weight: 0-8% SiO2; 34.5-46% B2O3; 2.6-6% Li2O; 21-38% ZnO; 0-40% La2O3; 0-35% Gd2O3; and 0-15% Y2O3, with the total content of La2O3+Gd2O3+Y2O3 accounting for 10-40%. The optical glass also has a predetermined index of refraction and a predetermined dispersion.