| 摘要 |
PURPOSE: To lower the intensity of incoming light which is the flare light and to prevent the impairment of visible ray transmittance to general light by forming one of glass substrates of color glass and determining the thickness of the color glass according to the diffraction efficiency of a hologram. CONSTITUTION: The out-of-vehicle side of front windshields glass is formed of the color glass 14 which is made, for example, blue. Colorless clear glass 13 is used for the in-vehicle side. Both are laminated via an intermediate film 25. The hologram 22 is sealed between two sheets of the glass plates 13 and 14. In such a case, the thickness of the color glass 14 constituting the sandwich glass is determined according to the diffraction efficiency of the hologram so as to satisfy the sufficient visible ray transmittance and to decrease flare light 29. As a result, the incoming light 28 is absorbed by the optical glass 14 so as to decrease the flare light 29 while the requirements specified to the visible ray transmittance are satisfied. |
