| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an optical element of small size and with high light extraction efficiency, and to provide a lighting device using the same. <P>SOLUTION: If an end part on a Z-axis direction origin side of a total reflection surface is further positioned on a Z-axis direction front side than a light-emitting surface of an LED light source, part of light emitted from the light-emitting surface is incident onto a surface not functioning as a total reflection surface so as to be losed, this is because the light to be losed has an emission angle with large slanting angle relative to an optical axis. Therefore, by using an LED with a Lambertian type light-emitting distribution, the loss light volume is extremely small and can be ignored. <P>COPYRIGHT: (C)2013,JPO&INPIT |
