| 摘要 |
PROBLEM TO BE SOLVED: To obtain an antireflection film having the min. number of layers which hardly causes loss in light quantity by reflection and shows no double refraction by forming layers in such a manner that the angles of oblique vapor deposition from the objective body for vapor deposition make a right angle between a first layer and a second layer. SOLUTION: The layers are formed in such a manner that angles of oblique vapor deposition from the objective body make a right angle between the first layer 9 and the second layer 11. Namely, the antireflection film consists of the oblique vapor deposition film 9 as the first layer and the oblique vapor deposition film 11 as the second layer. The oblique vapor deposition film 11 is formed as a double refraction film having the center line 7 of the objective body as the fast phase axis and having the center line 8 as the slow phase axis and these optical axes are opposite to those of the oblique vapor deposition film 9 as the first layer. Therefore, the obtd. antireflection film has the same refractive index as a film having non-reflection conditions. By arranging the optical axes of the first layer 9 and the second layer 11 perpendicular to each other, double refraction of the films can be compensated. |
