| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an optical element having an optical inorganic thin film which hardly causes cracks or the like in an antireflection film or the like in a high temperature atmosphere such as a parked car in summer. <P>SOLUTION: The optical element has a multilayer antireflection film (optical inorganic thin film) 16 on a plastic substrate 10. At least one layer in the multilayer antireflection film 16 is made of the vapor deposition film of a sintered mixture of a composition containing 33 to 74 mass% titanium oxide (TiO<SB>x</SB>, wherein x ranges from 1.5 to 1.88), 19 to 65 mass% lanthanum oxide (La<SB>2</SB>O<SB>3</SB>) and 2 to 7 mass% titanium (Ti). <P>COPYRIGHT: (C)2005,JPO&NCIPI |
