Patent ID: 7531474

Claim:
A process for producing an optical element, which comprises softening a shaped glass material for press-molding under heat and press-molding the shaped glass material, said shaped glass material being formed of the optical glass comprising, by weight %, 17 to 30% P 2 O 5 , 30 to 60% Nb 2 O 5 and over 0% but not more than 20% TiO 2 as glass components, and containing Sb 2 O 3 in an amount of over 0% by weight but not more than 1% by weight based on the total content of the glass components excluding Sb 2 O 3 , and WO 3 and Bi 2 O 3 as optional components with a TiO 2 /(Nb 2 O 5 +TiO 2 +WO 3 +Bi 2 O 3 ) weight ratio of 0.11 or more, having a refractive index (nd) of 1.91 or more and an Abbe's number (νd) of 21or less and having a light transmittance that comes to be 70% at a wavelength of 500 nm or less.