| 摘要 |
PURPOSE:To provide an element excellent in a transmission factor by providing a thin film layer comprising thin films of equal thickness between the top of a glass base material and an ultraviolet-setting resin layer so as to remove harmful reflection generated between the glass base material and the ultraviolet- setting resin layer whose refractive indexes are different from each other. CONSTITUTION:On a glass base material of a refractive index 1.60, a single layer film 4 of a refractive index 1.54 as a first thin film group is vapor- deposited with a predetermined optical film thickness and thereon a resin layer 2 comprising an urethanacrylate compound of a refractive index 1,49 is provided in an aspherical shape. Further thereon, as a second thin film group 3 three layer reflection preventive film comprising respectively Al2O3, ZrO2 and MgF2 laminated in order from the side of the resin layer 2 with respectively specified optical film thickness is formed. |
