摘要 |
A light-emitting diode device is described, which includes a luminous body and a colloid. The luminous body has a light-emitting surface and a bottom surface on opposite sides. The luminous body has a first length, a first width and a beam angle. The colloid covers the luminous body. The colloid includes a first surface and a second surface on opposite sides. The second surface has a second length and a second width. The colloid has a refractive index. A distance between the light-emitting surface of the luminous body and the second surface of the colloid is smaller than a first value and greater than a second value. The first value < the second width - the first width 2 · cot alpha . The second value < the second width - the first width 2 · cot v . The sin alpha=1/the refractive index of the colloid, and the nu is a full width at half maximum of the beam angle. |