| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a double-sided light emission type surface light source capable of emitting light at high luminous efficiency. <P>SOLUTION: The surface light source uses a light guide plate having a light emitting diode as a light source on its end and a pattern of phosphor film on each surface of the light guide plate. The phosphor in the phosphor film is excited by the light emitting diode and emits fluorescence. Light passing through the phosphor film and light reflected or scattered by the phosphor film can be taken out from both surfaces of the light guide plate efficiently, which increases the luminous efficacy. The light source is obtained which is suitable for a surface light source which requires light emission to both planar directions such as signboards and emergency exit sign lighting. <P>COPYRIGHT: (C)2009,JPO&INPIT |
