| 摘要 |
There is provided a light-emitting device (1) comprising a light source comprising a plurality of light-emitting diodes (3), said light source having a light outcoupling surface (2); a base (4); an envelope (5) covering said light source, said envelope having a maximum diameter 2*R in a direction transversal to an imaginary axis extending. through said base and said envelope, around which imaginary axis said envelope is symmetrical; and a light scattering material (6) provided in the path of light from said light outcoupling surface; wherein said light outcoupling surface is located at a position at which said envelope has a diameter D in a direction transversal to said imaginary axis, and within a distance r from said imaginary axis, r is less or equal to D/4. The light emitting device provides high efficiency in terms of light flux in the forward direction in relation to the total flux from the light source. |
