| 摘要 |
PROBLEM TO BE SOLVED: To provide a lighting device improved in light use efficiency, related to the lighting device being, in particular, a light source of a projetion-type display device. SOLUTION: Light emitted from the light source 10 is condensed by a cylindrical lens 13. The cylindrical lens 13 refracts a light distribution at a large angle emitted from the light source 10 to narrow the light distribution angle. The light condensed by the cylindrical lens 13 advances to a lamp reflector 14. A cross-sectional shape of the lamp reflector 14 is aspheric on its incidence and emission planes and linear on its reflecting surface. At the incidence surface 14a of the lamp reflector 14, the light is further refracted to narrow the light distribution angle. The light advanced to the reflecting surface 14b is totally reflected and then refracted at the emission surface 14c, enters a cone lens 15, and becomes substantially parallel with an optical axis of the lighting device to enter an incidence side fly-eye lens 3. COPYRIGHT: (C)2011,JPO&INPIT |
