Patent ID: 7936126

Claim:
A light emitting diode (LED) lamp tube comprising: a lamp device including an elongated circuit board, and at least one row of LEDs electrically connected to said circuit board and arranged along a transverse direction; and a tubular enclosure extending along a longitudinal direction perpendicular to the transverse direction, said circuit board being disposed in said tubular enclosure such that said enclosure is divided into a non-illuminated portion and a light-receiving portion that is positioned for receiving light emitted by said LEDs, said light-receiving portion having two light-condensing side sections corresponding respectively to two sides of said circuit board, and a light-diffusing middle section corresponding to a middle portion of said circuit board and connected between said light-condensing side sections, an outer surface of said light-diffusing middle section having two diagonal surface portions that are disposed respectively at two opposite sides thereof, that are connected respectively to said light-condensing side sections, that are inclined with respect to the transverse and longitudinal directions, and that face away from each other, an outer surface of each of said light-condensing side sections having a curved convex surface portion protruding away from said LEDs, and a curved concave surface portion connected between said curved convex surface portion and a respective one of said diagonal surface portions of said light-diffusing middle section, said curved concave surface portion of said outer surface of each of said light-condensing side sections of said light-receiving portion having a smoothly varying curvature; whereby, said curved concave and convex surface portions of said light-condensing side sections cooperate with said diagonal surface portions of said light-diffusing middle section to diffuse uniformly LED light transmitted from an outer surface of said light-receiving portion of said enclosure.