| 摘要 |
PURPOSE:To prevent lowering of contrast by molding hard quality material to form at least one surface upon which fluorescent substance layer is laminated, out of two surfaces of fluorescent face baseplate made of soft glass of small refractive index. CONSTITUTION:Upon both faces of a fluorescent face baseplate 11 made of soft quality glass of small refractive index, hard quality glass layers 13 and 14 having relatively larger refractive index compared with a soft quality glass 11 is laminated by ion implantation process. And, a fluorescent substance layer 12 is laminated upon a fluorescent face side. In this way, a distance between a luminous point (P) of light totally reflected at an outer surface point (R) of a glass film 14 and an incidence point (P') is lengthened and a distinctly contrasted output image can be obtained. |
