Abstract: A lens includes a base and a protrusion formed on the base. The base defines a light incident face in a bottom face thereof. The protrusion forms a light emerging face at an outside face thereof. The light emerging face includes a freeform face, a first side face, a second side face, a third side face and a fourth side face. The freeform face, the first side face and the second side face diverge light along a first direction, and the freeform face, the third side face and the fourth side face converge light along a second direction. Thus, a rectangular light pattern is obtained.

Abstract: A light emitting diode (LED) lamp includes a base, LED chips mounted on base, and a lens covering the LED chips and engaging with the base. The lens includes an arc-shaped engaging portion, and an extending portion extending from a radial outer side of a top surface of the engaging portion with a radial inner side of the top surface of the engaging portion exposed. The engaging portion includes an outer side surface. A groove is defined in an underside of the engaging portion and receives the LED chips therein. The extending portion includes an inner light emitting surface extending upwardly and outwardly from the top surface of the engaging portion, an outer light emitting surface extending upwardly from a top edge of the outer side surface of the engaging portion, and a top light emitting surface interconnecting the outer light emitting surface and the inner light emitting surface.

Abstract: An exemplary lens includes a periphery acting as a light output surface of the lens, a light input surface surrounded by the light output surface, and a reflecting surface recessed downwardly towards the light input surface and surrounded by the light output surface. A top end of the reflecting surface connects with the light output surface. The reflecting surface extends downwardly and inwardly from top to bottom. Light emitted from the light source travels into the lens from the light input surface; a part of the light directly travels out the lens from the light output surface, and the other part of the light is arrived to the reflecting surface and reflected back to the lens by the reflecting surface and travels out the lens from the light output surface.

Abstract: A luminous device comprises a light emitting diode (LED) light bar, a heat dissipating device thermally connected with the LED light bar, and a lamp cover made of light permissive material, engaging with the heat dissipating device and covering the LED light bar. The lamp cover is semicylindrical shaped and comprises an outer surface and an inner surface opposite to the outer surface and facing the LED light bar. A thickness of the lamp cover in a radial cross section thereof gradually reduces from a middle of the lamp cover to two opposite lateral sides thereof. Light generated by the LED light bar converges toward a plane orthogonally extending through the middle of the lamp cover after the light travels through the lamp cover.