| 摘要 |
PROBLEM TO BE SOLVED: To obtain a practical reflection index of an incident reflection angle with wide visibility by adjusting and forming thickness of each layer of a low reflection film so as to be below a given reflection index. SOLUTION: Thickness of each layer of a low reflection film is, for example, about 20 nm in a first ITO thin film, about 25 nm in a first silicon dioxide thin film, about 45 nm in a second ITO thin film, and about 100 nm in a second silicon dioxide thin film. As a result, the spectroscopic reflection index becomes 1% or less when a light beam with the wavelength range of 490 to 640 nm for a light beam incident angle of 10 degrees. Further, for the incident angle of 10 degrees the reflection index up to a wavelength of 650 nm of the incident light beam is 1% or less, the reflection index up to a wavelength of 700 nm is 1.6% or less, and the reflection index up to a wavelength of 750 nm is 2.7% or less. Spectroscopic reflection index characteristics in which a value (y) for the reflection light degree of color is 0.10 or more and 0.25 or less is obtained when the wavelength range of the incident light beam for of the light beam incident angle of 10 degrees is 380 to 780 nm. |
