Patent ID: 8492298

Claim:
An optical glass comprising cationic components having the following composition and having a liquidus temperature of 800° C. or higher and lower than 1,000° C.: Si 4+ 3 cat % or more and 13 cat % or less B 3+ 40 cat % or more and less than 55 cat % La 3+ 4 cat % or more and 9 cat % or less Ca 2+ 6 cat % or more and 12 cat % or less Li + 11 cat % or more and 18 cat % or less Zn 2+ 6 cat % or more and 12 cat % or less Zr 4+ 1 cat % or more and 4 cat % or less Y 3+ 0 cat % or more and 0.5 cat % or less Gd 3+ 0 cat % or more and less than 0.3 cat % Ba 2+ 0 cat % or more and 0.5 cat % or less Mg 2+ 0 cat % or more and 2 cat % or less Ge 4+ 0 cat % or more and 1 cat % or less Na + +K + 0 cat % or more and 2 cat % or less W 6+ 0 cat % or more and 0.5 cat % or less Ta 5+ 0 cat % or more and 0.5 cat % or less Sb 3+ 0 cat % or more and 0.5 cat % or less H + 0 cat % or more and 10 cat % or less provided that Si 4+ /B 3+ is 0.05 or more and 0.3 or less, and Li + /Zn 2+ is 1.3 or more and 2.0 or less, the optical glass having a refractive index (nd) of 1.6 or more and less than 1.7 and an Abbe number (vd) of 50 or more and 56 or less.