Patent ID: 7572747

Claim:
An optical glass consisting essentially of: B 2 O 3 in an amount of 10-40 wt %; SiO 2 in an amount less than or equal to 5 wt %; ZnO in an amount less than or equal to 15 wt %; SrO in an amount less than or equal to 9 wt %; ZrO 2 in an amount less than or equal to 9 wt %; La 2 O 3 in an amount of 15 to 45 wt %; BaF 2 in an amount of 1 to 10 wt %; BaO in an amount less than or equal to 5 wt %; HfO 2 in an amount of 0.1 to 7.5 wt %; Gd 2 O 3 in an amount less than or equal to 16 wt %; CaO in an amount less than or equal to 7 wt %; ZrF 4 in an amount less than or equal to 5 wt %; Na 2 O in an amount less than or equal to 2 wt %; and Y 2 O 3 in an amount less than or equal to 16 wt %.