PPROBLEM TO BE SOLVED: To provide an optical glass having a refractive index (nSBd/SB) of 1.75 or higher, an Abbe's number (νSBd/SB) in the range of 15 to 40, and suited for precision mold press forming. PSOLUTION: The optical glass comprises components in amounts satisfying (% refers to mol% on the basis of an oxide) BSB2/SBOSB3/SB+SiOSB2/SBof 10 to 70%, BiSB2/SBOSB3/SBof 5 to below 25%, and RO+RnSB2/SBO of 5 to 60% (wherein R is at least one member selected from the group consisting of Zn, Ba, Sr, Ca, and Mg; and Rn is at least one member selected from the group consisting of Li, Na, K, and Cs), being highly transparent in the visible region, and having a transition temperature (Tg) of 520°C or lower. In one embodiment, the optical glass has a spectral transmittance of 70% or higher at a wavelength of 550 nm in a thickness of 10 mm. PCOPYRIGHT: (C)2007,JPO&INPIT
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机译：
要解决的问题：要提供折射率（n d ）为1.75或更高的光学玻璃，请在光学玻璃中使用阿贝数（＆nu; d ）。 15至40的范围，适用于精密模压成型。
解决方案：光学玻璃包含的组分含量满足以下要求（％表示基于氧化物的mol％）B 2 O 3 + SiO 2 （占10％至70％），Bi 2 O 3 （占5％至25％以下）和RO + Rn 2 O（占5％）至60％（其中R是选自Zn，Ba，Sr，Ca和Mg的至少一种; Rn是选自Li，Na，K和Cs的至少一种） ，在可见光区域是高度透明的，并且具有520℃或更低的转变温度（Tg）。在一实施例中，光学玻璃在10mm的厚度下在550nm的波长处具有70％或更高的光谱透射率。
