| 摘要 |
<P>PROBLEM TO BE SOLVED: To prevent luminous intensity of a lighting device from degrading as a view angle becomes larger. <P>SOLUTION: The lighting device 1 is provided with a mounting substrate 2, a light-emitting portion 3 having an optical axis 31 almost perpendicularly crossing the mounting substrate 2, and a lens 4 controlling distribution of light emitted from the light-emitting portion 3. The lens 4 forms such a convex lens type shape 41 that a cross-sectional shape S(0) including an optical axis 31 and a cross-sectional shape surface S(θ) obtained by rotating the surface S(0) by an arbitrary viewing angle θ around a viewing axis 32, continuously change. And a lens diameter d(θ) of the convex lens type shape 41 increases as the viewing angle θ increases. With this, an incident light flux into the lens 4 is not reduced even if the viewing angle increases, and degradation of luminous intensity of the lighting device 1 is prevented. <P>COPYRIGHT: (C)2011,JPO&INPIT |
