| 摘要 |
A light-emitting diode (LED) lighting apparatus includes a housing, a light-emitting diode and a convex lens. The distance between the LED and the convex lens is less than two times of the focal length of the convex lens. When distance between the LED and the convex lens is changed, beam angle is fast changed so that the brightness for long distance is increased and illumination scope for short distance is increased without using reflective cone.
|
