| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an antireflection film which exhibits lower reflectivity in a wider band region. <P>SOLUTION: The antireflection film C1 is disposed on a surface 100S of an optical substrate 100 and is a multilayered film consisting of first to tenth layers stacked sequentially from an opposite side to the optical substrate 100. Here, the first layer 1, the fourth layer 4 and the ninth layer 9 are low-refractive index layers made of a low-refractive index material exhibiting a refractive index of 1.35 to 1.50 with respect to a d-line. The third layer 3, the fifth layer 5, the seventh layer 7 and the tenth layer 10 are intermediate-refractive index layers made of an intermediate-refractive index material exhibiting a refractive index of 1.55 to 1.85 with respect to the d-line. The second layer 2, the sixth layer 6 and the eighth layer 8 are high-refractive index layers made of a high-refractive index material exhibiting a refractive index that is in a range from 1.70 to 2.50 with respect to the d-line and that is higher than the refractive index of the intermediate-refractive index material. <P>COPYRIGHT: (C)2007,JPO&INPIT |
