| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an antireflection film that is suitable for an optical substrate having a relatively high refractive index, and has a lower reflectance in a broad wavelength range. <P>SOLUTION: The antireflection film C1 comprises first layer 1 to fifth layer 5 successively laminated on the surface 100S of an optical substrate 100 having a refractive index of 1.75 to 2.10 to d-line. The first layer and the third layer 3 are made of an intermediate refractive index material having a refractive index of 1.53 to 2.50 to d-line, the second layer 2 and the fourth layer 4 are made of a high refractive index material having a refractive index of 1.90 to 2.50 to d-line, and the fifth layer 5 is made of a low refractive index material having a refractive index of 1.35 to 1.50 to d-line. The first layer 1 to the fifth layer 5 have optical film thicknesses satisfying conditional expressions (1) to (5). <P>COPYRIGHT: (C)2008,JPO&INPIT |
