| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a structure of a leans for illumination capable of varying directivity only by rotating a lens by forming a plurality of curved surfaces of different curvatures on a single lens, and arranging a light source at one vertex of the lens. <P>SOLUTION: An LED chip 3 is mounted on a printed board 2, and a lens 1 having a directivity in the light emitting direction of the LED chip 3 is arranged on the front surface of the LED chip 3. The lens 1 is a regular tetrahedron comprising four vertexes, a, b, c, and d. Four curved surfaces A, B, C, and D consisting of different curvatures A1, B1, C1, and D1 are formed through three vertexes within the four vertexes a, b, c, and d. The LED chip 3 is arranged near one arbitrary vertex among the four vertexes, with the lens being held/fixed by other three vertexes. Only by rotation a single lens, light is emitted from the curved surfaces of different curvature to vary directivity. <P>COPYRIGHT: (C)2007,JPO&INPIT |
