| 摘要 |
<p>Disclosed is an optical glass having a high refractive index and high moldability.</p><p>An optical glass according to an embodiment of the invention includes Bi<Sub>2</Sub>O<Sub>3</Sub>, B<Sub>2</Sub>O<Sub>3</Sub>, SiO<Sub>2</Sub>, Al<Sub>2</Sub>O<Sub>3</Sub>, and ZnO and satisfies the following Conditional expressions 1 and 2: <MathDetails id="matha01" num="(1)"><MathText><![CDATA[ <math display="block"><mi mathvariant="normal">X</mi><mo>+</mo><mi mathvariant="normal">Y</mi><mo>≥</mo><mn>75</mn></math><img id="ia01" file="imga0001.tif" wi="52" he="10" img-content="math" img-format="tif" /> ]]></MathText></MathDetails> and <MathDetails id="matha02" num="(2)"><MathText><![CDATA[ <math display="block"><mn>2.5</mn><mo><</mo><mi mathvariant="normal">X</mi><mo>/</mo><mi mathvariant="normal">Y</mi><mo><</mo><mn>13</mn></math><img id="ia02" file="imga0002.tif" wi="64" he="8" img-content="math" img-format="tif" /> ]]></MathText></MathDetails> where X indicates the content (wt%) of Bi<Sub>2</Sub>O<Sub>3</Sub> and Y indicates the content (wt%) of B<Sub>2</Sub>O<Sub>3</Sub>. When Conditional expression 1 is satisfied, it is possible to avoid crystallization and ensure high transparency. If the ratio is greater than the lower limit of Conditional expression 2, the refractive index nd of the optical glass with respect to the d-line is equal to or greater than 1.9. If the ratio is less than the upper limit of Conditional expression 2, it is easy to perform vitrification.</p> |
